Ethernet for Nucleo and Disco board STM32F746 works with gcc and arm. IAC is untested
Fork of F7_Ethernet by
lwip/core/tcp_in.c@2:e0a4035b5cd1, 2016-10-06 (annotated)
- Committer:
- rctaduio
- Date:
- Thu Oct 06 16:55:16 2016 +0000
- Revision:
- 2:e0a4035b5cd1
- Parent:
- 0:d26c1b55cfca
Ethernet library for F7
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
DieterGraef | 0:d26c1b55cfca | 1 | /** |
DieterGraef | 0:d26c1b55cfca | 2 | * @file |
DieterGraef | 0:d26c1b55cfca | 3 | * Transmission Control Protocol, incoming traffic |
DieterGraef | 0:d26c1b55cfca | 4 | * |
DieterGraef | 0:d26c1b55cfca | 5 | * The input processing functions of the TCP layer. |
DieterGraef | 0:d26c1b55cfca | 6 | * |
DieterGraef | 0:d26c1b55cfca | 7 | * These functions are generally called in the order (ip_input() ->) |
DieterGraef | 0:d26c1b55cfca | 8 | * tcp_input() -> * tcp_process() -> tcp_receive() (-> application). |
DieterGraef | 0:d26c1b55cfca | 9 | * |
DieterGraef | 0:d26c1b55cfca | 10 | */ |
DieterGraef | 0:d26c1b55cfca | 11 | |
DieterGraef | 0:d26c1b55cfca | 12 | /* |
DieterGraef | 0:d26c1b55cfca | 13 | * Copyright (c) 2001-2004 Swedish Institute of Computer Science. |
DieterGraef | 0:d26c1b55cfca | 14 | * All rights reserved. |
DieterGraef | 0:d26c1b55cfca | 15 | * |
DieterGraef | 0:d26c1b55cfca | 16 | * Redistribution and use in source and binary forms, with or without modification, |
DieterGraef | 0:d26c1b55cfca | 17 | * are permitted provided that the following conditions are met: |
DieterGraef | 0:d26c1b55cfca | 18 | * |
DieterGraef | 0:d26c1b55cfca | 19 | * 1. Redistributions of source code must retain the above copyright notice, |
DieterGraef | 0:d26c1b55cfca | 20 | * this list of conditions and the following disclaimer. |
DieterGraef | 0:d26c1b55cfca | 21 | * 2. Redistributions in binary form must reproduce the above copyright notice, |
DieterGraef | 0:d26c1b55cfca | 22 | * this list of conditions and the following disclaimer in the documentation |
DieterGraef | 0:d26c1b55cfca | 23 | * and/or other materials provided with the distribution. |
DieterGraef | 0:d26c1b55cfca | 24 | * 3. The name of the author may not be used to endorse or promote products |
DieterGraef | 0:d26c1b55cfca | 25 | * derived from this software without specific prior written permission. |
DieterGraef | 0:d26c1b55cfca | 26 | * |
DieterGraef | 0:d26c1b55cfca | 27 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED |
DieterGraef | 0:d26c1b55cfca | 28 | * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
DieterGraef | 0:d26c1b55cfca | 29 | * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT |
DieterGraef | 0:d26c1b55cfca | 30 | * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
DieterGraef | 0:d26c1b55cfca | 31 | * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT |
DieterGraef | 0:d26c1b55cfca | 32 | * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
DieterGraef | 0:d26c1b55cfca | 33 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
DieterGraef | 0:d26c1b55cfca | 34 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING |
DieterGraef | 0:d26c1b55cfca | 35 | * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY |
DieterGraef | 0:d26c1b55cfca | 36 | * OF SUCH DAMAGE. |
DieterGraef | 0:d26c1b55cfca | 37 | * |
DieterGraef | 0:d26c1b55cfca | 38 | * This file is part of the lwIP TCP/IP stack. |
DieterGraef | 0:d26c1b55cfca | 39 | * |
DieterGraef | 0:d26c1b55cfca | 40 | * Author: Adam Dunkels <adam@sics.se> |
DieterGraef | 0:d26c1b55cfca | 41 | * |
DieterGraef | 0:d26c1b55cfca | 42 | */ |
DieterGraef | 0:d26c1b55cfca | 43 | |
DieterGraef | 0:d26c1b55cfca | 44 | #include "lwip/opt.h" |
DieterGraef | 0:d26c1b55cfca | 45 | |
DieterGraef | 0:d26c1b55cfca | 46 | #if LWIP_TCP /* don't build if not configured for use in lwipopts.h */ |
DieterGraef | 0:d26c1b55cfca | 47 | |
DieterGraef | 0:d26c1b55cfca | 48 | #include "lwip/tcp_impl.h" |
DieterGraef | 0:d26c1b55cfca | 49 | #include "lwip/def.h" |
DieterGraef | 0:d26c1b55cfca | 50 | #include "lwip/ip_addr.h" |
DieterGraef | 0:d26c1b55cfca | 51 | #include "lwip/netif.h" |
DieterGraef | 0:d26c1b55cfca | 52 | #include "lwip/mem.h" |
DieterGraef | 0:d26c1b55cfca | 53 | #include "lwip/memp.h" |
DieterGraef | 0:d26c1b55cfca | 54 | #include "lwip/inet_chksum.h" |
DieterGraef | 0:d26c1b55cfca | 55 | #include "lwip/stats.h" |
DieterGraef | 0:d26c1b55cfca | 56 | #include "lwip/snmp.h" |
DieterGraef | 0:d26c1b55cfca | 57 | #include "arch/perf.h" |
DieterGraef | 0:d26c1b55cfca | 58 | |
DieterGraef | 0:d26c1b55cfca | 59 | /* These variables are global to all functions involved in the input |
DieterGraef | 0:d26c1b55cfca | 60 | processing of TCP segments. They are set by the tcp_input() |
DieterGraef | 0:d26c1b55cfca | 61 | function. */ |
DieterGraef | 0:d26c1b55cfca | 62 | static struct tcp_seg inseg; |
DieterGraef | 0:d26c1b55cfca | 63 | static struct tcp_hdr *tcphdr; |
DieterGraef | 0:d26c1b55cfca | 64 | static struct ip_hdr *iphdr; |
DieterGraef | 0:d26c1b55cfca | 65 | static u32_t seqno, ackno; |
DieterGraef | 0:d26c1b55cfca | 66 | static u8_t flags; |
DieterGraef | 0:d26c1b55cfca | 67 | static u16_t tcplen; |
DieterGraef | 0:d26c1b55cfca | 68 | |
DieterGraef | 0:d26c1b55cfca | 69 | static u8_t recv_flags; |
DieterGraef | 0:d26c1b55cfca | 70 | static struct pbuf *recv_data; |
DieterGraef | 0:d26c1b55cfca | 71 | |
DieterGraef | 0:d26c1b55cfca | 72 | struct tcp_pcb *tcp_input_pcb; |
DieterGraef | 0:d26c1b55cfca | 73 | |
DieterGraef | 0:d26c1b55cfca | 74 | /* Forward declarations. */ |
DieterGraef | 0:d26c1b55cfca | 75 | static err_t tcp_process(struct tcp_pcb *pcb); |
DieterGraef | 0:d26c1b55cfca | 76 | static void tcp_receive(struct tcp_pcb *pcb); |
DieterGraef | 0:d26c1b55cfca | 77 | static void tcp_parseopt(struct tcp_pcb *pcb); |
DieterGraef | 0:d26c1b55cfca | 78 | |
DieterGraef | 0:d26c1b55cfca | 79 | static err_t tcp_listen_input(struct tcp_pcb_listen *pcb); |
DieterGraef | 0:d26c1b55cfca | 80 | static err_t tcp_timewait_input(struct tcp_pcb *pcb); |
DieterGraef | 0:d26c1b55cfca | 81 | |
DieterGraef | 0:d26c1b55cfca | 82 | /** |
DieterGraef | 0:d26c1b55cfca | 83 | * The initial input processing of TCP. It verifies the TCP header, demultiplexes |
DieterGraef | 0:d26c1b55cfca | 84 | * the segment between the PCBs and passes it on to tcp_process(), which implements |
DieterGraef | 0:d26c1b55cfca | 85 | * the TCP finite state machine. This function is called by the IP layer (in |
DieterGraef | 0:d26c1b55cfca | 86 | * ip_input()). |
DieterGraef | 0:d26c1b55cfca | 87 | * |
DieterGraef | 0:d26c1b55cfca | 88 | * @param p received TCP segment to process (p->payload pointing to the IP header) |
DieterGraef | 0:d26c1b55cfca | 89 | * @param inp network interface on which this segment was received |
DieterGraef | 0:d26c1b55cfca | 90 | */ |
DieterGraef | 0:d26c1b55cfca | 91 | void |
DieterGraef | 0:d26c1b55cfca | 92 | tcp_input(struct pbuf *p, struct netif *inp) |
DieterGraef | 0:d26c1b55cfca | 93 | { |
DieterGraef | 0:d26c1b55cfca | 94 | struct tcp_pcb *pcb = NULL; |
DieterGraef | 0:d26c1b55cfca | 95 | struct tcp_pcb *prev = NULL; |
DieterGraef | 0:d26c1b55cfca | 96 | struct tcp_pcb_listen *lpcb = NULL; |
DieterGraef | 0:d26c1b55cfca | 97 | #if SO_REUSE |
DieterGraef | 0:d26c1b55cfca | 98 | struct tcp_pcb *lpcb_prev = NULL; |
DieterGraef | 0:d26c1b55cfca | 99 | struct tcp_pcb_listen *lpcb_any = NULL; |
DieterGraef | 0:d26c1b55cfca | 100 | #endif /* SO_REUSE */ |
DieterGraef | 0:d26c1b55cfca | 101 | u8_t hdrlen; |
DieterGraef | 0:d26c1b55cfca | 102 | err_t err; |
DieterGraef | 0:d26c1b55cfca | 103 | |
DieterGraef | 0:d26c1b55cfca | 104 | PERF_START; |
DieterGraef | 0:d26c1b55cfca | 105 | |
DieterGraef | 0:d26c1b55cfca | 106 | TCP_STATS_INC(tcp.recv); |
DieterGraef | 0:d26c1b55cfca | 107 | snmp_inc_tcpinsegs(); |
DieterGraef | 0:d26c1b55cfca | 108 | |
DieterGraef | 0:d26c1b55cfca | 109 | iphdr = (struct ip_hdr *)p->payload; |
DieterGraef | 0:d26c1b55cfca | 110 | tcphdr = (struct tcp_hdr *)((u8_t *)p->payload + IPH_HL(iphdr) * 4); |
DieterGraef | 0:d26c1b55cfca | 111 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input_tcp_in: p 0x%x p->len %"U16_F" p->tot_len %"U16_F"\n",p->payload, p->len, p->tot_len)); |
DieterGraef | 0:d26c1b55cfca | 112 | #if TCP_INPUT_DEBUG |
DieterGraef | 0:d26c1b55cfca | 113 | tcp_debug_print(tcphdr); |
DieterGraef | 0:d26c1b55cfca | 114 | #endif |
DieterGraef | 0:d26c1b55cfca | 115 | |
DieterGraef | 0:d26c1b55cfca | 116 | /* remove header from payload */ |
DieterGraef | 0:d26c1b55cfca | 117 | if (pbuf_header(p, -((s16_t)(IPH_HL(iphdr) * 4))) || (p->tot_len < sizeof(struct tcp_hdr))) { |
DieterGraef | 0:d26c1b55cfca | 118 | /* drop short packets */ |
DieterGraef | 0:d26c1b55cfca | 119 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet (%"U16_F" bytes) discarded\n", p->tot_len)); |
DieterGraef | 0:d26c1b55cfca | 120 | TCP_STATS_INC(tcp.lenerr); |
DieterGraef | 0:d26c1b55cfca | 121 | goto dropped; |
DieterGraef | 0:d26c1b55cfca | 122 | } |
DieterGraef | 0:d26c1b55cfca | 123 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("payload_tcp_in: p 0x%x p->len %"U16_F" p->tot_len %"U16_F"\n",p->payload, p->len, p->tot_len)); |
DieterGraef | 0:d26c1b55cfca | 124 | /* Don't even process incoming broadcasts/multicasts. */ |
DieterGraef | 0:d26c1b55cfca | 125 | if (ip_addr_isbroadcast(¤t_iphdr_dest, inp) || |
DieterGraef | 0:d26c1b55cfca | 126 | ip_addr_ismulticast(¤t_iphdr_dest)) { |
DieterGraef | 0:d26c1b55cfca | 127 | TCP_STATS_INC(tcp.proterr); |
DieterGraef | 0:d26c1b55cfca | 128 | goto dropped; |
DieterGraef | 0:d26c1b55cfca | 129 | } |
DieterGraef | 0:d26c1b55cfca | 130 | |
DieterGraef | 0:d26c1b55cfca | 131 | #if CHECKSUM_CHECK_TCP |
DieterGraef | 0:d26c1b55cfca | 132 | /* Verify TCP checksum. */ |
DieterGraef | 0:d26c1b55cfca | 133 | if (inet_chksum_pseudo(p, ip_current_src_addr(), ip_current_dest_addr(), |
DieterGraef | 0:d26c1b55cfca | 134 | IP_PROTO_TCP, p->tot_len) != 0) { |
DieterGraef | 0:d26c1b55cfca | 135 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packet discarded due to failing checksum 0x%04"X16_F"\n", |
DieterGraef | 0:d26c1b55cfca | 136 | inet_chksum_pseudo(p, ip_current_src_addr(), ip_current_dest_addr(), |
DieterGraef | 0:d26c1b55cfca | 137 | IP_PROTO_TCP, p->tot_len))); |
DieterGraef | 0:d26c1b55cfca | 138 | #if TCP_DEBUG |
DieterGraef | 0:d26c1b55cfca | 139 | tcp_debug_print(tcphdr); |
DieterGraef | 0:d26c1b55cfca | 140 | #endif /* TCP_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 141 | TCP_STATS_INC(tcp.chkerr); |
DieterGraef | 0:d26c1b55cfca | 142 | goto dropped; |
DieterGraef | 0:d26c1b55cfca | 143 | } |
DieterGraef | 0:d26c1b55cfca | 144 | #endif |
DieterGraef | 0:d26c1b55cfca | 145 | |
DieterGraef | 0:d26c1b55cfca | 146 | /* Move the payload pointer in the pbuf so that it points to the |
DieterGraef | 0:d26c1b55cfca | 147 | TCP data instead of the TCP header. */ |
DieterGraef | 0:d26c1b55cfca | 148 | hdrlen = TCPH_HDRLEN(tcphdr); |
DieterGraef | 0:d26c1b55cfca | 149 | if(pbuf_header(p, -(hdrlen * 4))){ |
DieterGraef | 0:d26c1b55cfca | 150 | /* drop short packets */ |
DieterGraef | 0:d26c1b55cfca | 151 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: short packet\n")); |
DieterGraef | 0:d26c1b55cfca | 152 | TCP_STATS_INC(tcp.lenerr); |
DieterGraef | 0:d26c1b55cfca | 153 | goto dropped; |
DieterGraef | 0:d26c1b55cfca | 154 | } |
DieterGraef | 0:d26c1b55cfca | 155 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("payload in pbuf: p 0x%x p->len %"U16_F" p->tot_len %"U16_F"\n",p->payload, p->len, p->tot_len)); |
DieterGraef | 0:d26c1b55cfca | 156 | /* Convert fields in TCP header to host byte order. */ |
DieterGraef | 0:d26c1b55cfca | 157 | tcphdr->src = ntohs(tcphdr->src); |
DieterGraef | 0:d26c1b55cfca | 158 | tcphdr->dest = ntohs(tcphdr->dest); |
DieterGraef | 0:d26c1b55cfca | 159 | seqno = tcphdr->seqno = ntohl(tcphdr->seqno); |
DieterGraef | 0:d26c1b55cfca | 160 | ackno = tcphdr->ackno = ntohl(tcphdr->ackno); |
DieterGraef | 0:d26c1b55cfca | 161 | tcphdr->wnd = ntohs(tcphdr->wnd); |
DieterGraef | 0:d26c1b55cfca | 162 | |
DieterGraef | 0:d26c1b55cfca | 163 | flags = TCPH_FLAGS(tcphdr); |
DieterGraef | 0:d26c1b55cfca | 164 | tcplen = p->tot_len + ((flags & (TCP_FIN | TCP_SYN)) ? 1 : 0); |
DieterGraef | 0:d26c1b55cfca | 165 | |
DieterGraef | 0:d26c1b55cfca | 166 | /* Demultiplex an incoming segment. First, we check if it is destined |
DieterGraef | 0:d26c1b55cfca | 167 | for an active connection. */ |
DieterGraef | 0:d26c1b55cfca | 168 | prev = NULL; |
DieterGraef | 0:d26c1b55cfca | 169 | |
DieterGraef | 0:d26c1b55cfca | 170 | |
DieterGraef | 0:d26c1b55cfca | 171 | for(pcb = tcp_active_pcbs; pcb != NULL; pcb = pcb->next) { |
DieterGraef | 0:d26c1b55cfca | 172 | LWIP_ASSERT("tcp_input: active pcb->state != CLOSED", pcb->state != CLOSED); |
DieterGraef | 0:d26c1b55cfca | 173 | LWIP_ASSERT("tcp_input: active pcb->state != TIME-WAIT", pcb->state != TIME_WAIT); |
DieterGraef | 0:d26c1b55cfca | 174 | LWIP_ASSERT("tcp_input: active pcb->state != LISTEN", pcb->state != LISTEN); |
DieterGraef | 0:d26c1b55cfca | 175 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("active conn: pcb->remote_port %"U16_F" tcphdr->src %"U16_F" pcb->local_port %"U16_F" tcphdr->dest %"U16_F"\n",pcb->remote_port,tcphdr->src,pcb->local_port,tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 176 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("active conn: pcb->remote_ip %lx current_iphdr_src %lx pcb->local_ip %lx current_iphdr_dest %lx \n",pcb->remote_ip,current_iphdr_src,pcb->local_ip,current_iphdr_dest)); |
DieterGraef | 0:d26c1b55cfca | 177 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("active conn: pcb %x \n",pcb)); |
DieterGraef | 0:d26c1b55cfca | 178 | if (pcb->remote_port == tcphdr->src && |
DieterGraef | 0:d26c1b55cfca | 179 | pcb->local_port == tcphdr->dest && |
DieterGraef | 0:d26c1b55cfca | 180 | ip_addr_cmp(&(pcb->remote_ip), ¤t_iphdr_src) && |
DieterGraef | 0:d26c1b55cfca | 181 | ip_addr_cmp(&(pcb->local_ip), ¤t_iphdr_dest)) { |
DieterGraef | 0:d26c1b55cfca | 182 | |
DieterGraef | 0:d26c1b55cfca | 183 | /* Move this PCB to the front of the list so that subsequent |
DieterGraef | 0:d26c1b55cfca | 184 | lookups will be faster (we exploit locality in TCP segment |
DieterGraef | 0:d26c1b55cfca | 185 | arrivals). */ |
DieterGraef | 0:d26c1b55cfca | 186 | LWIP_ASSERT("tcp_input: pcb->next != pcb (before cache)", pcb->next != pcb); |
DieterGraef | 0:d26c1b55cfca | 187 | if (prev != NULL) { |
DieterGraef | 0:d26c1b55cfca | 188 | prev->next = pcb->next; |
DieterGraef | 0:d26c1b55cfca | 189 | pcb->next = tcp_active_pcbs; |
DieterGraef | 0:d26c1b55cfca | 190 | tcp_active_pcbs = pcb; |
DieterGraef | 0:d26c1b55cfca | 191 | } |
DieterGraef | 0:d26c1b55cfca | 192 | LWIP_ASSERT("tcp_input: pcb->next != pcb (after cache)", pcb->next != pcb); |
DieterGraef | 0:d26c1b55cfca | 193 | break; |
DieterGraef | 0:d26c1b55cfca | 194 | } |
DieterGraef | 0:d26c1b55cfca | 195 | prev = pcb; |
DieterGraef | 0:d26c1b55cfca | 196 | } |
DieterGraef | 0:d26c1b55cfca | 197 | |
DieterGraef | 0:d26c1b55cfca | 198 | if (pcb == NULL) { |
DieterGraef | 0:d26c1b55cfca | 199 | /* If it did not go to an active connection, we check the connections |
DieterGraef | 0:d26c1b55cfca | 200 | in the TIME-WAIT state. */ |
DieterGraef | 0:d26c1b55cfca | 201 | for(pcb = tcp_tw_pcbs; pcb != NULL; pcb = pcb->next) { |
DieterGraef | 0:d26c1b55cfca | 202 | LWIP_ASSERT("tcp_input: TIME-WAIT pcb->state == TIME-WAIT", pcb->state == TIME_WAIT); |
DieterGraef | 0:d26c1b55cfca | 203 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("wait conn: pcb->remote_port %"U16_F" tcphdr->src %"U16_F" pcb->local_port %"U16_F" tcphdr->dest %"U16_F"\n",pcb->remote_port,tcphdr->src,pcb->local_port,tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 204 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("wait conn: pcb->remote_ip %lx current_iphdr_src %lx pcb->local_ip %lx current_iphdr_dest %lx \n",pcb->remote_ip,current_iphdr_src,pcb->local_ip,current_iphdr_dest)); |
DieterGraef | 0:d26c1b55cfca | 205 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("wait conn: pcb %x \n",pcb)); |
DieterGraef | 0:d26c1b55cfca | 206 | if (pcb->remote_port == tcphdr->src && |
DieterGraef | 0:d26c1b55cfca | 207 | pcb->local_port == tcphdr->dest && |
DieterGraef | 0:d26c1b55cfca | 208 | ip_addr_cmp(&(pcb->remote_ip), ¤t_iphdr_src) && |
DieterGraef | 0:d26c1b55cfca | 209 | ip_addr_cmp(&(pcb->local_ip), ¤t_iphdr_dest)) { |
DieterGraef | 0:d26c1b55cfca | 210 | /* We don't really care enough to move this PCB to the front |
DieterGraef | 0:d26c1b55cfca | 211 | of the list since we are not very likely to receive that |
DieterGraef | 0:d26c1b55cfca | 212 | many segments for connections in TIME-WAIT. */ |
DieterGraef | 0:d26c1b55cfca | 213 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for TIME_WAITing connection.\n")); |
DieterGraef | 0:d26c1b55cfca | 214 | tcp_timewait_input(pcb); |
DieterGraef | 0:d26c1b55cfca | 215 | pbuf_free(p); |
DieterGraef | 0:d26c1b55cfca | 216 | return; |
DieterGraef | 0:d26c1b55cfca | 217 | } |
DieterGraef | 0:d26c1b55cfca | 218 | } |
DieterGraef | 0:d26c1b55cfca | 219 | |
DieterGraef | 0:d26c1b55cfca | 220 | /* Finally, if we still did not get a match, we check all PCBs that |
DieterGraef | 0:d26c1b55cfca | 221 | are LISTENing for incoming connections. */ |
DieterGraef | 0:d26c1b55cfca | 222 | prev = NULL; |
DieterGraef | 0:d26c1b55cfca | 223 | for(lpcb = tcp_listen_pcbs.listen_pcbs; lpcb != NULL; lpcb = lpcb->next) { |
DieterGraef | 0:d26c1b55cfca | 224 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("incomming conn: lpcb->local_port %"U16_F" tcphdr->dest %"U16_F"\n",lpcb->local_port,tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 225 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("incomming conn: lpcb->local_ip %lx current_iphdr_dest %lx \n",lpcb->local_ip,current_iphdr_dest)); |
DieterGraef | 0:d26c1b55cfca | 226 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("incomming conn: lpcb %x \n",lpcb)); |
DieterGraef | 0:d26c1b55cfca | 227 | |
DieterGraef | 0:d26c1b55cfca | 228 | if (lpcb->local_port == tcphdr->dest) { |
DieterGraef | 0:d26c1b55cfca | 229 | #if SO_REUSE |
DieterGraef | 0:d26c1b55cfca | 230 | if (ip_addr_cmp(&(lpcb->local_ip), ¤t_iphdr_dest)) { |
DieterGraef | 0:d26c1b55cfca | 231 | /* found an exact match */ |
DieterGraef | 0:d26c1b55cfca | 232 | break; |
DieterGraef | 0:d26c1b55cfca | 233 | } else if(ip_addr_isany(&(lpcb->local_ip))) { |
DieterGraef | 0:d26c1b55cfca | 234 | /* found an ANY-match */ |
DieterGraef | 0:d26c1b55cfca | 235 | lpcb_any = lpcb; |
DieterGraef | 0:d26c1b55cfca | 236 | lpcb_prev = prev; |
DieterGraef | 0:d26c1b55cfca | 237 | } |
DieterGraef | 0:d26c1b55cfca | 238 | #else /* SO_REUSE */ |
DieterGraef | 0:d26c1b55cfca | 239 | if (ip_addr_cmp(&(lpcb->local_ip), ¤t_iphdr_dest) || |
DieterGraef | 0:d26c1b55cfca | 240 | ip_addr_isany(&(lpcb->local_ip))) { |
DieterGraef | 0:d26c1b55cfca | 241 | /* found a match */ |
DieterGraef | 0:d26c1b55cfca | 242 | break; |
DieterGraef | 0:d26c1b55cfca | 243 | } |
DieterGraef | 0:d26c1b55cfca | 244 | #endif /* SO_REUSE */ |
DieterGraef | 0:d26c1b55cfca | 245 | } |
DieterGraef | 0:d26c1b55cfca | 246 | prev = (struct tcp_pcb *)lpcb; |
DieterGraef | 0:d26c1b55cfca | 247 | } |
DieterGraef | 0:d26c1b55cfca | 248 | #if SO_REUSE |
DieterGraef | 0:d26c1b55cfca | 249 | /* first try specific local IP */ |
DieterGraef | 0:d26c1b55cfca | 250 | if (lpcb == NULL) { |
DieterGraef | 0:d26c1b55cfca | 251 | /* only pass to ANY if no specific local IP has been found */ |
DieterGraef | 0:d26c1b55cfca | 252 | lpcb = lpcb_any; |
DieterGraef | 0:d26c1b55cfca | 253 | prev = lpcb_prev; |
DieterGraef | 0:d26c1b55cfca | 254 | } |
DieterGraef | 0:d26c1b55cfca | 255 | #endif /* SO_REUSE */ |
DieterGraef | 0:d26c1b55cfca | 256 | if (lpcb != NULL) { |
DieterGraef | 0:d26c1b55cfca | 257 | /* Move this PCB to the front of the list so that subsequent |
DieterGraef | 0:d26c1b55cfca | 258 | lookups will be faster (we exploit locality in TCP segment |
DieterGraef | 0:d26c1b55cfca | 259 | arrivals). */ |
DieterGraef | 0:d26c1b55cfca | 260 | if (prev != NULL) { |
DieterGraef | 0:d26c1b55cfca | 261 | ((struct tcp_pcb_listen *)prev)->next = lpcb->next; |
DieterGraef | 0:d26c1b55cfca | 262 | /* our successor is the remainder of the listening list */ |
DieterGraef | 0:d26c1b55cfca | 263 | lpcb->next = tcp_listen_pcbs.listen_pcbs; |
DieterGraef | 0:d26c1b55cfca | 264 | /* put this listening pcb at the head of the listening list */ |
DieterGraef | 0:d26c1b55cfca | 265 | tcp_listen_pcbs.listen_pcbs = lpcb; |
DieterGraef | 0:d26c1b55cfca | 266 | } |
DieterGraef | 0:d26c1b55cfca | 267 | |
DieterGraef | 0:d26c1b55cfca | 268 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: packed for LISTENing connection.\n")); |
DieterGraef | 0:d26c1b55cfca | 269 | tcp_listen_input(lpcb); |
DieterGraef | 0:d26c1b55cfca | 270 | pbuf_free(p); |
DieterGraef | 0:d26c1b55cfca | 271 | return; |
DieterGraef | 0:d26c1b55cfca | 272 | } |
DieterGraef | 0:d26c1b55cfca | 273 | } |
DieterGraef | 0:d26c1b55cfca | 274 | |
DieterGraef | 0:d26c1b55cfca | 275 | #if TCP_INPUT_DEBUG |
DieterGraef | 0:d26c1b55cfca | 276 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("+-+-+-+-+-+-+-+-+-+-+-+-+-+- tcp_input: flags ")); |
DieterGraef | 0:d26c1b55cfca | 277 | tcp_debug_print_flags(TCPH_FLAGS(tcphdr)); |
DieterGraef | 0:d26c1b55cfca | 278 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("-+-+-+-+-+-+-+-+-+-+-+-+-+-+\n")); |
DieterGraef | 0:d26c1b55cfca | 279 | #endif /* TCP_INPUT_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 280 | |
DieterGraef | 0:d26c1b55cfca | 281 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: pcb for inseg %x \n",pcb)); |
DieterGraef | 0:d26c1b55cfca | 282 | if (pcb != NULL) { |
DieterGraef | 0:d26c1b55cfca | 283 | /* The incoming segment belongs to a connection. */ |
DieterGraef | 0:d26c1b55cfca | 284 | #if TCP_INPUT_DEBUG |
DieterGraef | 0:d26c1b55cfca | 285 | #if TCP_DEBUG |
DieterGraef | 0:d26c1b55cfca | 286 | tcp_debug_print_state(pcb->state); |
DieterGraef | 0:d26c1b55cfca | 287 | #endif /* TCP_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 288 | #endif /* TCP_INPUT_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 289 | |
DieterGraef | 0:d26c1b55cfca | 290 | /* Set up a tcp_seg structure. */ |
DieterGraef | 0:d26c1b55cfca | 291 | inseg.next = NULL; |
DieterGraef | 0:d26c1b55cfca | 292 | inseg.len = p->tot_len; |
DieterGraef | 0:d26c1b55cfca | 293 | inseg.p = p; |
DieterGraef | 0:d26c1b55cfca | 294 | inseg.tcphdr = tcphdr; |
DieterGraef | 0:d26c1b55cfca | 295 | |
DieterGraef | 0:d26c1b55cfca | 296 | recv_data = NULL; |
DieterGraef | 0:d26c1b55cfca | 297 | recv_flags = 0; |
DieterGraef | 0:d26c1b55cfca | 298 | |
DieterGraef | 0:d26c1b55cfca | 299 | if (flags & TCP_PSH) { |
DieterGraef | 0:d26c1b55cfca | 300 | p->flags |= PBUF_FLAG_PUSH; |
DieterGraef | 0:d26c1b55cfca | 301 | } |
DieterGraef | 0:d26c1b55cfca | 302 | |
DieterGraef | 0:d26c1b55cfca | 303 | /* If there is data which was previously "refused" by upper layer */ |
DieterGraef | 0:d26c1b55cfca | 304 | if (pcb->refused_data != NULL) { |
DieterGraef | 0:d26c1b55cfca | 305 | if ((tcp_process_refused_data(pcb) == ERR_ABRT) || |
DieterGraef | 0:d26c1b55cfca | 306 | ((pcb->refused_data != NULL) && (tcplen > 0))) { |
DieterGraef | 0:d26c1b55cfca | 307 | /* pcb has been aborted or refused data is still refused and the new |
DieterGraef | 0:d26c1b55cfca | 308 | segment contains data */ |
DieterGraef | 0:d26c1b55cfca | 309 | TCP_STATS_INC(tcp.drop); |
DieterGraef | 0:d26c1b55cfca | 310 | snmp_inc_tcpinerrs(); |
DieterGraef | 0:d26c1b55cfca | 311 | goto aborted; |
DieterGraef | 0:d26c1b55cfca | 312 | } |
DieterGraef | 0:d26c1b55cfca | 313 | } |
DieterGraef | 0:d26c1b55cfca | 314 | tcp_input_pcb = pcb; |
DieterGraef | 0:d26c1b55cfca | 315 | err = tcp_process(pcb); |
DieterGraef | 0:d26c1b55cfca | 316 | /* A return value of ERR_ABRT means that tcp_abort() was called |
DieterGraef | 0:d26c1b55cfca | 317 | and that the pcb has been freed. If so, we don't do anything. */ |
DieterGraef | 0:d26c1b55cfca | 318 | if (err != ERR_ABRT) { |
DieterGraef | 0:d26c1b55cfca | 319 | if (recv_flags & TF_RESET) { |
DieterGraef | 0:d26c1b55cfca | 320 | /* TF_RESET means that the connection was reset by the other |
DieterGraef | 0:d26c1b55cfca | 321 | end. We then call the error callback to inform the |
DieterGraef | 0:d26c1b55cfca | 322 | application that the connection is dead before we |
DieterGraef | 0:d26c1b55cfca | 323 | deallocate the PCB. */ |
DieterGraef | 0:d26c1b55cfca | 324 | TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_RST); |
DieterGraef | 0:d26c1b55cfca | 325 | tcp_pcb_remove(&tcp_active_pcbs, pcb); |
DieterGraef | 0:d26c1b55cfca | 326 | memp_free(MEMP_TCP_PCB, pcb); |
DieterGraef | 0:d26c1b55cfca | 327 | } else if (recv_flags & TF_CLOSED) { |
DieterGraef | 0:d26c1b55cfca | 328 | /* The connection has been closed and we will deallocate the |
DieterGraef | 0:d26c1b55cfca | 329 | PCB. */ |
DieterGraef | 0:d26c1b55cfca | 330 | if (!(pcb->flags & TF_RXCLOSED)) { |
DieterGraef | 0:d26c1b55cfca | 331 | /* Connection closed although the application has only shut down the |
DieterGraef | 0:d26c1b55cfca | 332 | tx side: call the PCB's err callback and indicate the closure to |
DieterGraef | 0:d26c1b55cfca | 333 | ensure the application doesn't continue using the PCB. */ |
DieterGraef | 0:d26c1b55cfca | 334 | TCP_EVENT_ERR(pcb->errf, pcb->callback_arg, ERR_CLSD); |
DieterGraef | 0:d26c1b55cfca | 335 | } |
DieterGraef | 0:d26c1b55cfca | 336 | tcp_pcb_remove(&tcp_active_pcbs, pcb); |
DieterGraef | 0:d26c1b55cfca | 337 | memp_free(MEMP_TCP_PCB, pcb); |
DieterGraef | 0:d26c1b55cfca | 338 | } else { |
DieterGraef | 0:d26c1b55cfca | 339 | err = ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 340 | /* If the application has registered a "sent" function to be |
DieterGraef | 0:d26c1b55cfca | 341 | called when new send buffer space is available, we call it |
DieterGraef | 0:d26c1b55cfca | 342 | now. */ |
DieterGraef | 0:d26c1b55cfca | 343 | if (pcb->acked > 0) { |
DieterGraef | 0:d26c1b55cfca | 344 | TCP_EVENT_SENT(pcb, pcb->acked, err); |
DieterGraef | 0:d26c1b55cfca | 345 | if (err == ERR_ABRT) { |
DieterGraef | 0:d26c1b55cfca | 346 | goto aborted; |
DieterGraef | 0:d26c1b55cfca | 347 | } |
DieterGraef | 0:d26c1b55cfca | 348 | } |
DieterGraef | 0:d26c1b55cfca | 349 | |
DieterGraef | 0:d26c1b55cfca | 350 | if (recv_data != NULL) { |
DieterGraef | 0:d26c1b55cfca | 351 | LWIP_ASSERT("pcb->refused_data == NULL", pcb->refused_data == NULL); |
DieterGraef | 0:d26c1b55cfca | 352 | if (pcb->flags & TF_RXCLOSED) { |
DieterGraef | 0:d26c1b55cfca | 353 | /* received data although already closed -> abort (send RST) to |
DieterGraef | 0:d26c1b55cfca | 354 | notify the remote host that not all data has been processed */ |
DieterGraef | 0:d26c1b55cfca | 355 | pbuf_free(recv_data); |
DieterGraef | 0:d26c1b55cfca | 356 | tcp_abort(pcb); |
DieterGraef | 0:d26c1b55cfca | 357 | goto aborted; |
DieterGraef | 0:d26c1b55cfca | 358 | } |
DieterGraef | 0:d26c1b55cfca | 359 | |
DieterGraef | 0:d26c1b55cfca | 360 | /* Notify application that data has been received. */ |
DieterGraef | 0:d26c1b55cfca | 361 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("::::tcp_event_recv: pcb 0x%x data 0x%x len %"U16_F" \n",pcb,recv_data->payload,recv_data->len)); |
DieterGraef | 0:d26c1b55cfca | 362 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("::::tcp_event_recv: payload %s \n",(((pcb)->recv == NULL)?"rejected":"processed"))); |
DieterGraef | 0:d26c1b55cfca | 363 | |
DieterGraef | 0:d26c1b55cfca | 364 | TCP_EVENT_RECV(pcb, recv_data, ERR_OK, err); |
DieterGraef | 0:d26c1b55cfca | 365 | |
DieterGraef | 0:d26c1b55cfca | 366 | if (err == ERR_ABRT) { |
DieterGraef | 0:d26c1b55cfca | 367 | goto aborted; |
DieterGraef | 0:d26c1b55cfca | 368 | } |
DieterGraef | 0:d26c1b55cfca | 369 | |
DieterGraef | 0:d26c1b55cfca | 370 | /* If the upper layer can't receive this data, store it */ |
DieterGraef | 0:d26c1b55cfca | 371 | if (err != ERR_OK) { |
DieterGraef | 0:d26c1b55cfca | 372 | pcb->refused_data = recv_data; |
DieterGraef | 0:d26c1b55cfca | 373 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_input: keep incoming packet, because pcb is \"full\"\n")); |
DieterGraef | 0:d26c1b55cfca | 374 | } |
DieterGraef | 0:d26c1b55cfca | 375 | } |
DieterGraef | 0:d26c1b55cfca | 376 | |
DieterGraef | 0:d26c1b55cfca | 377 | /* If a FIN segment was received, we call the callback |
DieterGraef | 0:d26c1b55cfca | 378 | function with a NULL buffer to indicate EOF. */ |
DieterGraef | 0:d26c1b55cfca | 379 | if (recv_flags & TF_GOT_FIN) { |
DieterGraef | 0:d26c1b55cfca | 380 | if (pcb->refused_data != NULL) { |
DieterGraef | 0:d26c1b55cfca | 381 | /* Delay this if we have refused data. */ |
DieterGraef | 0:d26c1b55cfca | 382 | pcb->refused_data->flags |= PBUF_FLAG_TCP_FIN; |
DieterGraef | 0:d26c1b55cfca | 383 | } else { |
DieterGraef | 0:d26c1b55cfca | 384 | /* correct rcv_wnd as the application won't call tcp_recved() |
DieterGraef | 0:d26c1b55cfca | 385 | for the FIN's seqno */ |
DieterGraef | 0:d26c1b55cfca | 386 | if (pcb->rcv_wnd != TCP_WND) { |
DieterGraef | 0:d26c1b55cfca | 387 | pcb->rcv_wnd++; |
DieterGraef | 0:d26c1b55cfca | 388 | } |
DieterGraef | 0:d26c1b55cfca | 389 | TCP_EVENT_CLOSED(pcb, err); |
DieterGraef | 0:d26c1b55cfca | 390 | if (err == ERR_ABRT) { |
DieterGraef | 0:d26c1b55cfca | 391 | goto aborted; |
DieterGraef | 0:d26c1b55cfca | 392 | } |
DieterGraef | 0:d26c1b55cfca | 393 | } |
DieterGraef | 0:d26c1b55cfca | 394 | } |
DieterGraef | 0:d26c1b55cfca | 395 | |
DieterGraef | 0:d26c1b55cfca | 396 | tcp_input_pcb = NULL; |
DieterGraef | 0:d26c1b55cfca | 397 | /* Try to send something out. */ |
DieterGraef | 0:d26c1b55cfca | 398 | tcp_output(pcb); |
DieterGraef | 0:d26c1b55cfca | 399 | #if TCP_INPUT_DEBUG |
DieterGraef | 0:d26c1b55cfca | 400 | #if TCP_DEBUG |
DieterGraef | 0:d26c1b55cfca | 401 | tcp_debug_print_state(pcb->state); |
DieterGraef | 0:d26c1b55cfca | 402 | #endif /* TCP_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 403 | #endif /* TCP_INPUT_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 404 | } |
DieterGraef | 0:d26c1b55cfca | 405 | } |
DieterGraef | 0:d26c1b55cfca | 406 | /* Jump target if pcb has been aborted in a callback (by calling tcp_abort()). |
DieterGraef | 0:d26c1b55cfca | 407 | Below this line, 'pcb' may not be dereferenced! */ |
DieterGraef | 0:d26c1b55cfca | 408 | aborted: |
DieterGraef | 0:d26c1b55cfca | 409 | tcp_input_pcb = NULL; |
DieterGraef | 0:d26c1b55cfca | 410 | recv_data = NULL; |
DieterGraef | 0:d26c1b55cfca | 411 | |
DieterGraef | 0:d26c1b55cfca | 412 | /* give up our reference to inseg.p */ |
DieterGraef | 0:d26c1b55cfca | 413 | if (inseg.p != NULL) |
DieterGraef | 0:d26c1b55cfca | 414 | { |
DieterGraef | 0:d26c1b55cfca | 415 | pbuf_free(inseg.p); |
DieterGraef | 0:d26c1b55cfca | 416 | inseg.p = NULL; |
DieterGraef | 0:d26c1b55cfca | 417 | } |
DieterGraef | 0:d26c1b55cfca | 418 | } else { |
DieterGraef | 0:d26c1b55cfca | 419 | |
DieterGraef | 0:d26c1b55cfca | 420 | /* If no matching PCB was found, send a TCP RST (reset) to the |
DieterGraef | 0:d26c1b55cfca | 421 | sender. */ |
DieterGraef | 0:d26c1b55cfca | 422 | LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_input: no PCB match found, resetting.\n")); |
DieterGraef | 0:d26c1b55cfca | 423 | if (!(TCPH_FLAGS(tcphdr) & TCP_RST)) { |
DieterGraef | 0:d26c1b55cfca | 424 | TCP_STATS_INC(tcp.proterr); |
DieterGraef | 0:d26c1b55cfca | 425 | TCP_STATS_INC(tcp.drop); |
DieterGraef | 0:d26c1b55cfca | 426 | tcp_rst(ackno, seqno + tcplen, |
DieterGraef | 0:d26c1b55cfca | 427 | ip_current_dest_addr(), ip_current_src_addr(), |
DieterGraef | 0:d26c1b55cfca | 428 | tcphdr->dest, tcphdr->src); |
DieterGraef | 0:d26c1b55cfca | 429 | } |
DieterGraef | 0:d26c1b55cfca | 430 | pbuf_free(p); |
DieterGraef | 0:d26c1b55cfca | 431 | } |
DieterGraef | 0:d26c1b55cfca | 432 | |
DieterGraef | 0:d26c1b55cfca | 433 | LWIP_ASSERT("tcp_input: tcp_pcbs_sane()", tcp_pcbs_sane()); |
DieterGraef | 0:d26c1b55cfca | 434 | PERF_STOP("tcp_input"); |
DieterGraef | 0:d26c1b55cfca | 435 | return; |
DieterGraef | 0:d26c1b55cfca | 436 | dropped: |
DieterGraef | 0:d26c1b55cfca | 437 | TCP_STATS_INC(tcp.drop); |
DieterGraef | 0:d26c1b55cfca | 438 | snmp_inc_tcpinerrs(); |
DieterGraef | 0:d26c1b55cfca | 439 | pbuf_free(p); |
DieterGraef | 0:d26c1b55cfca | 440 | } |
DieterGraef | 0:d26c1b55cfca | 441 | |
DieterGraef | 0:d26c1b55cfca | 442 | /** |
DieterGraef | 0:d26c1b55cfca | 443 | * Called by tcp_input() when a segment arrives for a listening |
DieterGraef | 0:d26c1b55cfca | 444 | * connection (from tcp_input()). |
DieterGraef | 0:d26c1b55cfca | 445 | * |
DieterGraef | 0:d26c1b55cfca | 446 | * @param pcb the tcp_pcb_listen for which a segment arrived |
DieterGraef | 0:d26c1b55cfca | 447 | * @return ERR_OK if the segment was processed |
DieterGraef | 0:d26c1b55cfca | 448 | * another err_t on error |
DieterGraef | 0:d26c1b55cfca | 449 | * |
DieterGraef | 0:d26c1b55cfca | 450 | * @note the return value is not (yet?) used in tcp_input() |
DieterGraef | 0:d26c1b55cfca | 451 | * @note the segment which arrived is saved in global variables, therefore only the pcb |
DieterGraef | 0:d26c1b55cfca | 452 | * involved is passed as a parameter to this function |
DieterGraef | 0:d26c1b55cfca | 453 | */ |
DieterGraef | 0:d26c1b55cfca | 454 | static err_t |
DieterGraef | 0:d26c1b55cfca | 455 | tcp_listen_input(struct tcp_pcb_listen *pcb) |
DieterGraef | 0:d26c1b55cfca | 456 | { |
DieterGraef | 0:d26c1b55cfca | 457 | struct tcp_pcb *npcb; |
DieterGraef | 0:d26c1b55cfca | 458 | err_t rc; |
DieterGraef | 0:d26c1b55cfca | 459 | |
DieterGraef | 0:d26c1b55cfca | 460 | if (flags & TCP_RST) { |
DieterGraef | 0:d26c1b55cfca | 461 | /* An incoming RST should be ignored. Return. */ |
DieterGraef | 0:d26c1b55cfca | 462 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 463 | } |
DieterGraef | 0:d26c1b55cfca | 464 | |
DieterGraef | 0:d26c1b55cfca | 465 | /* In the LISTEN state, we check for incoming SYN segments, |
DieterGraef | 0:d26c1b55cfca | 466 | creates a new PCB, and responds with a SYN|ACK. */ |
DieterGraef | 0:d26c1b55cfca | 467 | if (flags & TCP_ACK) { |
DieterGraef | 0:d26c1b55cfca | 468 | /* For incoming segments with the ACK flag set, respond with a |
DieterGraef | 0:d26c1b55cfca | 469 | RST. */ |
DieterGraef | 0:d26c1b55cfca | 470 | LWIP_DEBUGF(TCP_RST_DEBUG, ("tcp_listen_input: ACK in LISTEN, sending reset\n")); |
DieterGraef | 0:d26c1b55cfca | 471 | tcp_rst(ackno, seqno + tcplen, ip_current_dest_addr(), |
DieterGraef | 0:d26c1b55cfca | 472 | ip_current_src_addr(), tcphdr->dest, tcphdr->src); |
DieterGraef | 0:d26c1b55cfca | 473 | } else if (flags & TCP_SYN) { |
DieterGraef | 0:d26c1b55cfca | 474 | LWIP_DEBUGF(TCP_DEBUG, ("TCP connection request %"U16_F" -> %"U16_F".\n", tcphdr->src, tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 475 | #if TCP_LISTEN_BACKLOG |
DieterGraef | 0:d26c1b55cfca | 476 | if (pcb->accepts_pending >= pcb->backlog) { |
DieterGraef | 0:d26c1b55cfca | 477 | LWIP_DEBUGF(TCP_DEBUG, ("tcp_listen_input: listen backlog exceeded for port %"U16_F"\n", tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 478 | return ERR_ABRT; |
DieterGraef | 0:d26c1b55cfca | 479 | } |
DieterGraef | 0:d26c1b55cfca | 480 | #endif /* TCP_LISTEN_BACKLOG */ |
DieterGraef | 0:d26c1b55cfca | 481 | npcb = tcp_alloc(pcb->prio); |
DieterGraef | 0:d26c1b55cfca | 482 | /* If a new PCB could not be created (probably due to lack of memory), |
DieterGraef | 0:d26c1b55cfca | 483 | we don't do anything, but rely on the sender will retransmit the |
DieterGraef | 0:d26c1b55cfca | 484 | SYN at a time when we have more memory available. */ |
DieterGraef | 0:d26c1b55cfca | 485 | if (npcb == NULL) { |
DieterGraef | 0:d26c1b55cfca | 486 | LWIP_DEBUGF(TCP_DEBUG, ("tcp_listen_input: could not allocate PCB\n")); |
DieterGraef | 0:d26c1b55cfca | 487 | TCP_STATS_INC(tcp.memerr); |
DieterGraef | 0:d26c1b55cfca | 488 | return ERR_MEM; |
DieterGraef | 0:d26c1b55cfca | 489 | } |
DieterGraef | 0:d26c1b55cfca | 490 | #if TCP_LISTEN_BACKLOG |
DieterGraef | 0:d26c1b55cfca | 491 | pcb->accepts_pending++; |
DieterGraef | 0:d26c1b55cfca | 492 | #endif /* TCP_LISTEN_BACKLOG */ |
DieterGraef | 0:d26c1b55cfca | 493 | /* Set up the new PCB. */ |
DieterGraef | 0:d26c1b55cfca | 494 | ip_addr_copy(npcb->local_ip, current_iphdr_dest); |
DieterGraef | 0:d26c1b55cfca | 495 | npcb->local_port = pcb->local_port; |
DieterGraef | 0:d26c1b55cfca | 496 | ip_addr_copy(npcb->remote_ip, current_iphdr_src); |
DieterGraef | 0:d26c1b55cfca | 497 | npcb->remote_port = tcphdr->src; |
DieterGraef | 0:d26c1b55cfca | 498 | npcb->state = SYN_RCVD; |
DieterGraef | 0:d26c1b55cfca | 499 | npcb->rcv_nxt = seqno + 1; |
DieterGraef | 0:d26c1b55cfca | 500 | npcb->rcv_ann_right_edge = npcb->rcv_nxt; |
DieterGraef | 0:d26c1b55cfca | 501 | npcb->snd_wnd = tcphdr->wnd; |
DieterGraef | 0:d26c1b55cfca | 502 | npcb->snd_wnd_max = tcphdr->wnd; |
DieterGraef | 0:d26c1b55cfca | 503 | npcb->ssthresh = npcb->snd_wnd; |
DieterGraef | 0:d26c1b55cfca | 504 | npcb->snd_wl1 = seqno - 1;/* initialise to seqno-1 to force window update */ |
DieterGraef | 0:d26c1b55cfca | 505 | npcb->callback_arg = pcb->callback_arg; |
DieterGraef | 0:d26c1b55cfca | 506 | #if LWIP_CALLBACK_API |
DieterGraef | 0:d26c1b55cfca | 507 | npcb->accept = pcb->accept; |
DieterGraef | 0:d26c1b55cfca | 508 | #endif /* LWIP_CALLBACK_API */ |
DieterGraef | 0:d26c1b55cfca | 509 | /* inherit socket options */ |
DieterGraef | 0:d26c1b55cfca | 510 | npcb->so_options = pcb->so_options & SOF_INHERITED; |
DieterGraef | 0:d26c1b55cfca | 511 | /* Register the new PCB so that we can begin receiving segments |
DieterGraef | 0:d26c1b55cfca | 512 | for it. */ |
DieterGraef | 0:d26c1b55cfca | 513 | TCP_REG_ACTIVE(npcb); |
DieterGraef | 0:d26c1b55cfca | 514 | |
DieterGraef | 0:d26c1b55cfca | 515 | /* Parse any options in the SYN. */ |
DieterGraef | 0:d26c1b55cfca | 516 | tcp_parseopt(npcb); |
DieterGraef | 0:d26c1b55cfca | 517 | #if TCP_CALCULATE_EFF_SEND_MSS |
DieterGraef | 0:d26c1b55cfca | 518 | npcb->mss = tcp_eff_send_mss(npcb->mss, &(npcb->remote_ip)); |
DieterGraef | 0:d26c1b55cfca | 519 | #endif /* TCP_CALCULATE_EFF_SEND_MSS */ |
DieterGraef | 0:d26c1b55cfca | 520 | |
DieterGraef | 0:d26c1b55cfca | 521 | snmp_inc_tcppassiveopens(); |
DieterGraef | 0:d26c1b55cfca | 522 | |
DieterGraef | 0:d26c1b55cfca | 523 | /* Send a SYN|ACK together with the MSS option. */ |
DieterGraef | 0:d26c1b55cfca | 524 | rc = tcp_enqueue_flags(npcb, TCP_SYN | TCP_ACK); |
DieterGraef | 0:d26c1b55cfca | 525 | if (rc != ERR_OK) { |
DieterGraef | 0:d26c1b55cfca | 526 | tcp_abandon(npcb, 0); |
DieterGraef | 0:d26c1b55cfca | 527 | return rc; |
DieterGraef | 0:d26c1b55cfca | 528 | } |
DieterGraef | 0:d26c1b55cfca | 529 | return tcp_output(npcb); |
DieterGraef | 0:d26c1b55cfca | 530 | } |
DieterGraef | 0:d26c1b55cfca | 531 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 532 | } |
DieterGraef | 0:d26c1b55cfca | 533 | |
DieterGraef | 0:d26c1b55cfca | 534 | /** |
DieterGraef | 0:d26c1b55cfca | 535 | * Called by tcp_input() when a segment arrives for a connection in |
DieterGraef | 0:d26c1b55cfca | 536 | * TIME_WAIT. |
DieterGraef | 0:d26c1b55cfca | 537 | * |
DieterGraef | 0:d26c1b55cfca | 538 | * @param pcb the tcp_pcb for which a segment arrived |
DieterGraef | 0:d26c1b55cfca | 539 | * |
DieterGraef | 0:d26c1b55cfca | 540 | * @note the segment which arrived is saved in global variables, therefore only the pcb |
DieterGraef | 0:d26c1b55cfca | 541 | * involved is passed as a parameter to this function |
DieterGraef | 0:d26c1b55cfca | 542 | */ |
DieterGraef | 0:d26c1b55cfca | 543 | static err_t |
DieterGraef | 0:d26c1b55cfca | 544 | tcp_timewait_input(struct tcp_pcb *pcb) |
DieterGraef | 0:d26c1b55cfca | 545 | { |
DieterGraef | 0:d26c1b55cfca | 546 | /* RFC 1337: in TIME_WAIT, ignore RST and ACK FINs + any 'acceptable' segments */ |
DieterGraef | 0:d26c1b55cfca | 547 | /* RFC 793 3.9 Event Processing - Segment Arrives: |
DieterGraef | 0:d26c1b55cfca | 548 | * - first check sequence number - we skip that one in TIME_WAIT (always |
DieterGraef | 0:d26c1b55cfca | 549 | * acceptable since we only send ACKs) |
DieterGraef | 0:d26c1b55cfca | 550 | * - second check the RST bit (... return) */ |
DieterGraef | 0:d26c1b55cfca | 551 | if (flags & TCP_RST) { |
DieterGraef | 0:d26c1b55cfca | 552 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 553 | } |
DieterGraef | 0:d26c1b55cfca | 554 | /* - fourth, check the SYN bit, */ |
DieterGraef | 0:d26c1b55cfca | 555 | if (flags & TCP_SYN) { |
DieterGraef | 0:d26c1b55cfca | 556 | /* If an incoming segment is not acceptable, an acknowledgment |
DieterGraef | 0:d26c1b55cfca | 557 | should be sent in reply */ |
DieterGraef | 0:d26c1b55cfca | 558 | if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, pcb->rcv_nxt+pcb->rcv_wnd)) { |
DieterGraef | 0:d26c1b55cfca | 559 | /* If the SYN is in the window it is an error, send a reset */ |
DieterGraef | 0:d26c1b55cfca | 560 | tcp_rst(ackno, seqno + tcplen, ip_current_dest_addr(), ip_current_src_addr(), |
DieterGraef | 0:d26c1b55cfca | 561 | tcphdr->dest, tcphdr->src); |
DieterGraef | 0:d26c1b55cfca | 562 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 563 | } |
DieterGraef | 0:d26c1b55cfca | 564 | } else if (flags & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 565 | /* - eighth, check the FIN bit: Remain in the TIME-WAIT state. |
DieterGraef | 0:d26c1b55cfca | 566 | Restart the 2 MSL time-wait timeout.*/ |
DieterGraef | 0:d26c1b55cfca | 567 | pcb->tmr = tcp_ticks; |
DieterGraef | 0:d26c1b55cfca | 568 | } |
DieterGraef | 0:d26c1b55cfca | 569 | |
DieterGraef | 0:d26c1b55cfca | 570 | if ((tcplen > 0)) { |
DieterGraef | 0:d26c1b55cfca | 571 | /* Acknowledge data, FIN or out-of-window SYN */ |
DieterGraef | 0:d26c1b55cfca | 572 | pcb->flags |= TF_ACK_NOW; |
DieterGraef | 0:d26c1b55cfca | 573 | return tcp_output(pcb); |
DieterGraef | 0:d26c1b55cfca | 574 | } |
DieterGraef | 0:d26c1b55cfca | 575 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 576 | } |
DieterGraef | 0:d26c1b55cfca | 577 | |
DieterGraef | 0:d26c1b55cfca | 578 | /** |
DieterGraef | 0:d26c1b55cfca | 579 | * Implements the TCP state machine. Called by tcp_input. In some |
DieterGraef | 0:d26c1b55cfca | 580 | * states tcp_receive() is called to receive data. The tcp_seg |
DieterGraef | 0:d26c1b55cfca | 581 | * argument will be freed by the caller (tcp_input()) unless the |
DieterGraef | 0:d26c1b55cfca | 582 | * recv_data pointer in the pcb is set. |
DieterGraef | 0:d26c1b55cfca | 583 | * |
DieterGraef | 0:d26c1b55cfca | 584 | * @param pcb the tcp_pcb for which a segment arrived |
DieterGraef | 0:d26c1b55cfca | 585 | * |
DieterGraef | 0:d26c1b55cfca | 586 | * @note the segment which arrived is saved in global variables, therefore only the pcb |
DieterGraef | 0:d26c1b55cfca | 587 | * involved is passed as a parameter to this function |
DieterGraef | 0:d26c1b55cfca | 588 | */ |
DieterGraef | 0:d26c1b55cfca | 589 | static err_t |
DieterGraef | 0:d26c1b55cfca | 590 | tcp_process(struct tcp_pcb *pcb) |
DieterGraef | 0:d26c1b55cfca | 591 | { |
DieterGraef | 0:d26c1b55cfca | 592 | struct tcp_seg *rseg; |
DieterGraef | 0:d26c1b55cfca | 593 | u8_t acceptable = 0; |
DieterGraef | 0:d26c1b55cfca | 594 | err_t err; |
DieterGraef | 0:d26c1b55cfca | 595 | |
DieterGraef | 0:d26c1b55cfca | 596 | err = ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 597 | |
DieterGraef | 0:d26c1b55cfca | 598 | /* Process incoming RST segments. */ |
DieterGraef | 0:d26c1b55cfca | 599 | if (flags & TCP_RST) { |
DieterGraef | 0:d26c1b55cfca | 600 | /* First, determine if the reset is acceptable. */ |
DieterGraef | 0:d26c1b55cfca | 601 | if (pcb->state == SYN_SENT) { |
DieterGraef | 0:d26c1b55cfca | 602 | if (ackno == pcb->snd_nxt) { |
DieterGraef | 0:d26c1b55cfca | 603 | acceptable = 1; |
DieterGraef | 0:d26c1b55cfca | 604 | } |
DieterGraef | 0:d26c1b55cfca | 605 | } else { |
DieterGraef | 0:d26c1b55cfca | 606 | if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, |
DieterGraef | 0:d26c1b55cfca | 607 | pcb->rcv_nxt+pcb->rcv_wnd)) { |
DieterGraef | 0:d26c1b55cfca | 608 | acceptable = 1; |
DieterGraef | 0:d26c1b55cfca | 609 | } |
DieterGraef | 0:d26c1b55cfca | 610 | } |
DieterGraef | 0:d26c1b55cfca | 611 | |
DieterGraef | 0:d26c1b55cfca | 612 | if (acceptable) { |
DieterGraef | 0:d26c1b55cfca | 613 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_process: Connection RESET\n")); |
DieterGraef | 0:d26c1b55cfca | 614 | LWIP_ASSERT("tcp_input: pcb->state != CLOSED", pcb->state != CLOSED); |
DieterGraef | 0:d26c1b55cfca | 615 | recv_flags |= TF_RESET; |
DieterGraef | 0:d26c1b55cfca | 616 | pcb->flags &= ~TF_ACK_DELAY; |
DieterGraef | 0:d26c1b55cfca | 617 | return ERR_RST; |
DieterGraef | 0:d26c1b55cfca | 618 | } else { |
DieterGraef | 0:d26c1b55cfca | 619 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_process: unacceptable reset seqno %"U32_F" rcv_nxt %"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 620 | seqno, pcb->rcv_nxt)); |
DieterGraef | 0:d26c1b55cfca | 621 | LWIP_DEBUGF(TCP_DEBUG, ("tcp_process: unacceptable reset seqno %"U32_F" rcv_nxt %"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 622 | seqno, pcb->rcv_nxt)); |
DieterGraef | 0:d26c1b55cfca | 623 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 624 | } |
DieterGraef | 0:d26c1b55cfca | 625 | } |
DieterGraef | 0:d26c1b55cfca | 626 | |
DieterGraef | 0:d26c1b55cfca | 627 | if ((flags & TCP_SYN) && (pcb->state != SYN_SENT && pcb->state != SYN_RCVD)) { |
DieterGraef | 0:d26c1b55cfca | 628 | /* Cope with new connection attempt after remote end crashed */ |
DieterGraef | 0:d26c1b55cfca | 629 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 630 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 631 | } |
DieterGraef | 0:d26c1b55cfca | 632 | |
DieterGraef | 0:d26c1b55cfca | 633 | if ((pcb->flags & TF_RXCLOSED) == 0) { |
DieterGraef | 0:d26c1b55cfca | 634 | /* Update the PCB (in)activity timer unless rx is closed (see tcp_shutdown) */ |
DieterGraef | 0:d26c1b55cfca | 635 | pcb->tmr = tcp_ticks; |
DieterGraef | 0:d26c1b55cfca | 636 | } |
DieterGraef | 0:d26c1b55cfca | 637 | pcb->keep_cnt_sent = 0; |
DieterGraef | 0:d26c1b55cfca | 638 | |
DieterGraef | 0:d26c1b55cfca | 639 | tcp_parseopt(pcb); |
DieterGraef | 0:d26c1b55cfca | 640 | |
DieterGraef | 0:d26c1b55cfca | 641 | /* Do different things depending on the TCP state. */ |
DieterGraef | 0:d26c1b55cfca | 642 | switch (pcb->state) { |
DieterGraef | 0:d26c1b55cfca | 643 | case SYN_SENT: |
DieterGraef | 0:d26c1b55cfca | 644 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("SYN-SENT: ackno %"U32_F" pcb->snd_nxt %"U32_F" unacked %"U32_F"\n", ackno, |
DieterGraef | 0:d26c1b55cfca | 645 | pcb->snd_nxt, ntohl(pcb->unacked->tcphdr->seqno))); |
DieterGraef | 0:d26c1b55cfca | 646 | /* received SYN ACK with expected sequence number? */ |
DieterGraef | 0:d26c1b55cfca | 647 | if ((flags & TCP_ACK) && (flags & TCP_SYN) |
DieterGraef | 0:d26c1b55cfca | 648 | && ackno == ntohl(pcb->unacked->tcphdr->seqno) + 1) { |
DieterGraef | 0:d26c1b55cfca | 649 | pcb->snd_buf++; |
DieterGraef | 0:d26c1b55cfca | 650 | pcb->rcv_nxt = seqno + 1; |
DieterGraef | 0:d26c1b55cfca | 651 | pcb->rcv_ann_right_edge = pcb->rcv_nxt; |
DieterGraef | 0:d26c1b55cfca | 652 | pcb->lastack = ackno; |
DieterGraef | 0:d26c1b55cfca | 653 | pcb->snd_wnd = tcphdr->wnd; |
DieterGraef | 0:d26c1b55cfca | 654 | pcb->snd_wnd_max = tcphdr->wnd; |
DieterGraef | 0:d26c1b55cfca | 655 | pcb->snd_wl1 = seqno - 1; /* initialise to seqno - 1 to force window update */ |
DieterGraef | 0:d26c1b55cfca | 656 | pcb->state = ESTABLISHED; |
DieterGraef | 0:d26c1b55cfca | 657 | |
DieterGraef | 0:d26c1b55cfca | 658 | #if TCP_CALCULATE_EFF_SEND_MSS |
DieterGraef | 0:d26c1b55cfca | 659 | pcb->mss = tcp_eff_send_mss(pcb->mss, &(pcb->remote_ip)); |
DieterGraef | 0:d26c1b55cfca | 660 | #endif /* TCP_CALCULATE_EFF_SEND_MSS */ |
DieterGraef | 0:d26c1b55cfca | 661 | |
DieterGraef | 0:d26c1b55cfca | 662 | /* Set ssthresh again after changing pcb->mss (already set in tcp_connect |
DieterGraef | 0:d26c1b55cfca | 663 | * but for the default value of pcb->mss) */ |
DieterGraef | 0:d26c1b55cfca | 664 | pcb->ssthresh = pcb->mss * 10; |
DieterGraef | 0:d26c1b55cfca | 665 | |
DieterGraef | 0:d26c1b55cfca | 666 | pcb->cwnd = ((pcb->cwnd == 1) ? (pcb->mss * 2) : pcb->mss); |
DieterGraef | 0:d26c1b55cfca | 667 | LWIP_ASSERT("pcb->snd_queuelen > 0", (pcb->snd_queuelen > 0)); |
DieterGraef | 0:d26c1b55cfca | 668 | --pcb->snd_queuelen; |
DieterGraef | 0:d26c1b55cfca | 669 | LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_process: SYN-SENT --queuelen %"U16_F"\n", (u16_t)pcb->snd_queuelen)); |
DieterGraef | 0:d26c1b55cfca | 670 | rseg = pcb->unacked; |
DieterGraef | 0:d26c1b55cfca | 671 | pcb->unacked = rseg->next; |
DieterGraef | 0:d26c1b55cfca | 672 | tcp_seg_free(rseg); |
DieterGraef | 0:d26c1b55cfca | 673 | |
DieterGraef | 0:d26c1b55cfca | 674 | /* If there's nothing left to acknowledge, stop the retransmit |
DieterGraef | 0:d26c1b55cfca | 675 | timer, otherwise reset it to start again */ |
DieterGraef | 0:d26c1b55cfca | 676 | if(pcb->unacked == NULL) |
DieterGraef | 0:d26c1b55cfca | 677 | pcb->rtime = -1; |
DieterGraef | 0:d26c1b55cfca | 678 | else { |
DieterGraef | 0:d26c1b55cfca | 679 | pcb->rtime = 0; |
DieterGraef | 0:d26c1b55cfca | 680 | pcb->nrtx = 0; |
DieterGraef | 0:d26c1b55cfca | 681 | } |
DieterGraef | 0:d26c1b55cfca | 682 | |
DieterGraef | 0:d26c1b55cfca | 683 | /* Call the user specified function to call when sucessfully |
DieterGraef | 0:d26c1b55cfca | 684 | * connected. */ |
DieterGraef | 0:d26c1b55cfca | 685 | TCP_EVENT_CONNECTED(pcb, ERR_OK, err); |
DieterGraef | 0:d26c1b55cfca | 686 | if (err == ERR_ABRT) { |
DieterGraef | 0:d26c1b55cfca | 687 | return ERR_ABRT; |
DieterGraef | 0:d26c1b55cfca | 688 | } |
DieterGraef | 0:d26c1b55cfca | 689 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 690 | } |
DieterGraef | 0:d26c1b55cfca | 691 | /* received ACK? possibly a half-open connection */ |
DieterGraef | 0:d26c1b55cfca | 692 | else if (flags & TCP_ACK) { |
DieterGraef | 0:d26c1b55cfca | 693 | /* send a RST to bring the other side in a non-synchronized state. */ |
DieterGraef | 0:d26c1b55cfca | 694 | tcp_rst(ackno, seqno + tcplen, ip_current_dest_addr(), ip_current_src_addr(), |
DieterGraef | 0:d26c1b55cfca | 695 | tcphdr->dest, tcphdr->src); |
DieterGraef | 0:d26c1b55cfca | 696 | } |
DieterGraef | 0:d26c1b55cfca | 697 | break; |
DieterGraef | 0:d26c1b55cfca | 698 | case SYN_RCVD: |
DieterGraef | 0:d26c1b55cfca | 699 | if (flags & TCP_ACK) { |
DieterGraef | 0:d26c1b55cfca | 700 | /* expected ACK number? */ |
DieterGraef | 0:d26c1b55cfca | 701 | if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)) { |
DieterGraef | 0:d26c1b55cfca | 702 | u16_t old_cwnd; |
DieterGraef | 0:d26c1b55cfca | 703 | pcb->state = ESTABLISHED; |
DieterGraef | 0:d26c1b55cfca | 704 | LWIP_DEBUGF(TCP_DEBUG, ("TCP connection established %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 705 | #if LWIP_CALLBACK_API |
DieterGraef | 0:d26c1b55cfca | 706 | LWIP_ASSERT("pcb->accept != NULL", pcb->accept != NULL); |
DieterGraef | 0:d26c1b55cfca | 707 | #endif |
DieterGraef | 0:d26c1b55cfca | 708 | /* Call the accept function. */ |
DieterGraef | 0:d26c1b55cfca | 709 | TCP_EVENT_ACCEPT(pcb, ERR_OK, err); |
DieterGraef | 0:d26c1b55cfca | 710 | if (err != ERR_OK) { |
DieterGraef | 0:d26c1b55cfca | 711 | /* If the accept function returns with an error, we abort |
DieterGraef | 0:d26c1b55cfca | 712 | * the connection. */ |
DieterGraef | 0:d26c1b55cfca | 713 | /* Already aborted? */ |
DieterGraef | 0:d26c1b55cfca | 714 | if (err != ERR_ABRT) { |
DieterGraef | 0:d26c1b55cfca | 715 | tcp_abort(pcb); |
DieterGraef | 0:d26c1b55cfca | 716 | } |
DieterGraef | 0:d26c1b55cfca | 717 | return ERR_ABRT; |
DieterGraef | 0:d26c1b55cfca | 718 | } |
DieterGraef | 0:d26c1b55cfca | 719 | old_cwnd = pcb->cwnd; |
DieterGraef | 0:d26c1b55cfca | 720 | /* If there was any data contained within this ACK, |
DieterGraef | 0:d26c1b55cfca | 721 | * we'd better pass it on to the application as well. */ |
DieterGraef | 0:d26c1b55cfca | 722 | tcp_receive(pcb); |
DieterGraef | 0:d26c1b55cfca | 723 | |
DieterGraef | 0:d26c1b55cfca | 724 | /* Prevent ACK for SYN to generate a sent event */ |
DieterGraef | 0:d26c1b55cfca | 725 | if (pcb->acked != 0) { |
DieterGraef | 0:d26c1b55cfca | 726 | pcb->acked--; |
DieterGraef | 0:d26c1b55cfca | 727 | } |
DieterGraef | 0:d26c1b55cfca | 728 | |
DieterGraef | 0:d26c1b55cfca | 729 | pcb->cwnd = ((old_cwnd == 1) ? (pcb->mss * 2) : pcb->mss); |
DieterGraef | 0:d26c1b55cfca | 730 | |
DieterGraef | 0:d26c1b55cfca | 731 | if (recv_flags & TF_GOT_FIN) { |
DieterGraef | 0:d26c1b55cfca | 732 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 733 | pcb->state = CLOSE_WAIT; |
DieterGraef | 0:d26c1b55cfca | 734 | } |
DieterGraef | 0:d26c1b55cfca | 735 | } else { |
DieterGraef | 0:d26c1b55cfca | 736 | /* incorrect ACK number, send RST */ |
DieterGraef | 0:d26c1b55cfca | 737 | tcp_rst(ackno, seqno + tcplen, ip_current_dest_addr(), ip_current_src_addr(), |
DieterGraef | 0:d26c1b55cfca | 738 | tcphdr->dest, tcphdr->src); |
DieterGraef | 0:d26c1b55cfca | 739 | } |
DieterGraef | 0:d26c1b55cfca | 740 | } else if ((flags & TCP_SYN) && (seqno == pcb->rcv_nxt - 1)) { |
DieterGraef | 0:d26c1b55cfca | 741 | /* Looks like another copy of the SYN - retransmit our SYN-ACK */ |
DieterGraef | 0:d26c1b55cfca | 742 | tcp_rexmit(pcb); |
DieterGraef | 0:d26c1b55cfca | 743 | } |
DieterGraef | 0:d26c1b55cfca | 744 | break; |
DieterGraef | 0:d26c1b55cfca | 745 | case CLOSE_WAIT: |
DieterGraef | 0:d26c1b55cfca | 746 | /* FALLTHROUGH */ |
DieterGraef | 0:d26c1b55cfca | 747 | case ESTABLISHED: |
DieterGraef | 0:d26c1b55cfca | 748 | tcp_receive(pcb); |
DieterGraef | 0:d26c1b55cfca | 749 | if (recv_flags & TF_GOT_FIN) { /* passive close */ |
DieterGraef | 0:d26c1b55cfca | 750 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 751 | pcb->state = CLOSE_WAIT; |
DieterGraef | 0:d26c1b55cfca | 752 | } |
DieterGraef | 0:d26c1b55cfca | 753 | break; |
DieterGraef | 0:d26c1b55cfca | 754 | case FIN_WAIT_1: |
DieterGraef | 0:d26c1b55cfca | 755 | tcp_receive(pcb); |
DieterGraef | 0:d26c1b55cfca | 756 | if (recv_flags & TF_GOT_FIN) { |
DieterGraef | 0:d26c1b55cfca | 757 | if ((flags & TCP_ACK) && (ackno == pcb->snd_nxt)) { |
DieterGraef | 0:d26c1b55cfca | 758 | LWIP_DEBUGF(TCP_DEBUG, |
DieterGraef | 0:d26c1b55cfca | 759 | ("TCP connection closed: FIN_WAIT_1 %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 760 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 761 | tcp_pcb_purge(pcb); |
DieterGraef | 0:d26c1b55cfca | 762 | TCP_RMV_ACTIVE(pcb); |
DieterGraef | 0:d26c1b55cfca | 763 | pcb->state = TIME_WAIT; |
DieterGraef | 0:d26c1b55cfca | 764 | TCP_REG(&tcp_tw_pcbs, pcb); |
DieterGraef | 0:d26c1b55cfca | 765 | } else { |
DieterGraef | 0:d26c1b55cfca | 766 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 767 | pcb->state = CLOSING; |
DieterGraef | 0:d26c1b55cfca | 768 | } |
DieterGraef | 0:d26c1b55cfca | 769 | } else if ((flags & TCP_ACK) && (ackno == pcb->snd_nxt)) { |
DieterGraef | 0:d26c1b55cfca | 770 | pcb->state = FIN_WAIT_2; |
DieterGraef | 0:d26c1b55cfca | 771 | } |
DieterGraef | 0:d26c1b55cfca | 772 | break; |
DieterGraef | 0:d26c1b55cfca | 773 | case FIN_WAIT_2: |
DieterGraef | 0:d26c1b55cfca | 774 | tcp_receive(pcb); |
DieterGraef | 0:d26c1b55cfca | 775 | if (recv_flags & TF_GOT_FIN) { |
DieterGraef | 0:d26c1b55cfca | 776 | LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: FIN_WAIT_2 %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 777 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 778 | tcp_pcb_purge(pcb); |
DieterGraef | 0:d26c1b55cfca | 779 | TCP_RMV_ACTIVE(pcb); |
DieterGraef | 0:d26c1b55cfca | 780 | pcb->state = TIME_WAIT; |
DieterGraef | 0:d26c1b55cfca | 781 | TCP_REG(&tcp_tw_pcbs, pcb); |
DieterGraef | 0:d26c1b55cfca | 782 | } |
DieterGraef | 0:d26c1b55cfca | 783 | break; |
DieterGraef | 0:d26c1b55cfca | 784 | case CLOSING: |
DieterGraef | 0:d26c1b55cfca | 785 | tcp_receive(pcb); |
DieterGraef | 0:d26c1b55cfca | 786 | if (flags & TCP_ACK && ackno == pcb->snd_nxt) { |
DieterGraef | 0:d26c1b55cfca | 787 | LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: CLOSING %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 788 | tcp_pcb_purge(pcb); |
DieterGraef | 0:d26c1b55cfca | 789 | TCP_RMV_ACTIVE(pcb); |
DieterGraef | 0:d26c1b55cfca | 790 | pcb->state = TIME_WAIT; |
DieterGraef | 0:d26c1b55cfca | 791 | TCP_REG(&tcp_tw_pcbs, pcb); |
DieterGraef | 0:d26c1b55cfca | 792 | } |
DieterGraef | 0:d26c1b55cfca | 793 | break; |
DieterGraef | 0:d26c1b55cfca | 794 | case LAST_ACK: |
DieterGraef | 0:d26c1b55cfca | 795 | tcp_receive(pcb); |
DieterGraef | 0:d26c1b55cfca | 796 | if (flags & TCP_ACK && ackno == pcb->snd_nxt) { |
DieterGraef | 0:d26c1b55cfca | 797 | LWIP_DEBUGF(TCP_DEBUG, ("TCP connection closed: LAST_ACK %"U16_F" -> %"U16_F".\n", inseg.tcphdr->src, inseg.tcphdr->dest)); |
DieterGraef | 0:d26c1b55cfca | 798 | /* bugfix #21699: don't set pcb->state to CLOSED here or we risk leaking segments */ |
DieterGraef | 0:d26c1b55cfca | 799 | recv_flags |= TF_CLOSED; |
DieterGraef | 0:d26c1b55cfca | 800 | } |
DieterGraef | 0:d26c1b55cfca | 801 | break; |
DieterGraef | 0:d26c1b55cfca | 802 | default: |
DieterGraef | 0:d26c1b55cfca | 803 | break; |
DieterGraef | 0:d26c1b55cfca | 804 | } |
DieterGraef | 0:d26c1b55cfca | 805 | return ERR_OK; |
DieterGraef | 0:d26c1b55cfca | 806 | } |
DieterGraef | 0:d26c1b55cfca | 807 | |
DieterGraef | 0:d26c1b55cfca | 808 | #if TCP_QUEUE_OOSEQ |
DieterGraef | 0:d26c1b55cfca | 809 | /** |
DieterGraef | 0:d26c1b55cfca | 810 | * Insert segment into the list (segments covered with new one will be deleted) |
DieterGraef | 0:d26c1b55cfca | 811 | * |
DieterGraef | 0:d26c1b55cfca | 812 | * Called from tcp_receive() |
DieterGraef | 0:d26c1b55cfca | 813 | */ |
DieterGraef | 0:d26c1b55cfca | 814 | static void |
DieterGraef | 0:d26c1b55cfca | 815 | tcp_oos_insert_segment(struct tcp_seg *cseg, struct tcp_seg *next) |
DieterGraef | 0:d26c1b55cfca | 816 | { |
DieterGraef | 0:d26c1b55cfca | 817 | struct tcp_seg *old_seg; |
DieterGraef | 0:d26c1b55cfca | 818 | |
DieterGraef | 0:d26c1b55cfca | 819 | if (TCPH_FLAGS(cseg->tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 820 | /* received segment overlaps all following segments */ |
DieterGraef | 0:d26c1b55cfca | 821 | tcp_segs_free(next); |
DieterGraef | 0:d26c1b55cfca | 822 | next = NULL; |
DieterGraef | 0:d26c1b55cfca | 823 | } |
DieterGraef | 0:d26c1b55cfca | 824 | else { |
DieterGraef | 0:d26c1b55cfca | 825 | /* delete some following segments |
DieterGraef | 0:d26c1b55cfca | 826 | oos queue may have segments with FIN flag */ |
DieterGraef | 0:d26c1b55cfca | 827 | while (next && |
DieterGraef | 0:d26c1b55cfca | 828 | TCP_SEQ_GEQ((seqno + cseg->len), |
DieterGraef | 0:d26c1b55cfca | 829 | (next->tcphdr->seqno + next->len))) { |
DieterGraef | 0:d26c1b55cfca | 830 | /* cseg with FIN already processed */ |
DieterGraef | 0:d26c1b55cfca | 831 | if (TCPH_FLAGS(next->tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 832 | TCPH_SET_FLAG(cseg->tcphdr, TCP_FIN); |
DieterGraef | 0:d26c1b55cfca | 833 | } |
DieterGraef | 0:d26c1b55cfca | 834 | old_seg = next; |
DieterGraef | 0:d26c1b55cfca | 835 | next = next->next; |
DieterGraef | 0:d26c1b55cfca | 836 | tcp_seg_free(old_seg); |
DieterGraef | 0:d26c1b55cfca | 837 | } |
DieterGraef | 0:d26c1b55cfca | 838 | if (next && |
DieterGraef | 0:d26c1b55cfca | 839 | TCP_SEQ_GT(seqno + cseg->len, next->tcphdr->seqno)) { |
DieterGraef | 0:d26c1b55cfca | 840 | /* We need to trim the incoming segment. */ |
DieterGraef | 0:d26c1b55cfca | 841 | cseg->len = (u16_t)(next->tcphdr->seqno - seqno); |
DieterGraef | 0:d26c1b55cfca | 842 | pbuf_realloc(cseg->p, cseg->len); |
DieterGraef | 0:d26c1b55cfca | 843 | } |
DieterGraef | 0:d26c1b55cfca | 844 | } |
DieterGraef | 0:d26c1b55cfca | 845 | cseg->next = next; |
DieterGraef | 0:d26c1b55cfca | 846 | } |
DieterGraef | 0:d26c1b55cfca | 847 | #endif /* TCP_QUEUE_OOSEQ */ |
DieterGraef | 0:d26c1b55cfca | 848 | |
DieterGraef | 0:d26c1b55cfca | 849 | /** |
DieterGraef | 0:d26c1b55cfca | 850 | * Called by tcp_process. Checks if the given segment is an ACK for outstanding |
DieterGraef | 0:d26c1b55cfca | 851 | * data, and if so frees the memory of the buffered data. Next, is places the |
DieterGraef | 0:d26c1b55cfca | 852 | * segment on any of the receive queues (pcb->recved or pcb->ooseq). If the segment |
DieterGraef | 0:d26c1b55cfca | 853 | * is buffered, the pbuf is referenced by pbuf_ref so that it will not be freed until |
DieterGraef | 0:d26c1b55cfca | 854 | * it has been removed from the buffer. |
DieterGraef | 0:d26c1b55cfca | 855 | * |
DieterGraef | 0:d26c1b55cfca | 856 | * If the incoming segment constitutes an ACK for a segment that was used for RTT |
DieterGraef | 0:d26c1b55cfca | 857 | * estimation, the RTT is estimated here as well. |
DieterGraef | 0:d26c1b55cfca | 858 | * |
DieterGraef | 0:d26c1b55cfca | 859 | * Called from tcp_process(). |
DieterGraef | 0:d26c1b55cfca | 860 | */ |
DieterGraef | 0:d26c1b55cfca | 861 | static void |
DieterGraef | 0:d26c1b55cfca | 862 | tcp_receive(struct tcp_pcb *pcb) |
DieterGraef | 0:d26c1b55cfca | 863 | { |
DieterGraef | 0:d26c1b55cfca | 864 | struct tcp_seg *next; |
DieterGraef | 0:d26c1b55cfca | 865 | #if TCP_QUEUE_OOSEQ |
DieterGraef | 0:d26c1b55cfca | 866 | struct tcp_seg *prev, *cseg; |
DieterGraef | 0:d26c1b55cfca | 867 | #endif /* TCP_QUEUE_OOSEQ */ |
DieterGraef | 0:d26c1b55cfca | 868 | struct pbuf *p; |
DieterGraef | 0:d26c1b55cfca | 869 | s32_t off; |
DieterGraef | 0:d26c1b55cfca | 870 | s16_t m; |
DieterGraef | 0:d26c1b55cfca | 871 | u32_t right_wnd_edge; |
DieterGraef | 0:d26c1b55cfca | 872 | u16_t new_tot_len; |
DieterGraef | 0:d26c1b55cfca | 873 | int found_dupack = 0; |
DieterGraef | 0:d26c1b55cfca | 874 | #if TCP_OOSEQ_MAX_BYTES || TCP_OOSEQ_MAX_PBUFS |
DieterGraef | 0:d26c1b55cfca | 875 | u32_t ooseq_blen; |
DieterGraef | 0:d26c1b55cfca | 876 | u16_t ooseq_qlen; |
DieterGraef | 0:d26c1b55cfca | 877 | #endif /* TCP_OOSEQ_MAX_BYTES || TCP_OOSEQ_MAX_PBUFS */ |
DieterGraef | 0:d26c1b55cfca | 878 | |
DieterGraef | 0:d26c1b55cfca | 879 | LWIP_ASSERT("tcp_receive: wrong state", pcb->state >= ESTABLISHED); |
DieterGraef | 0:d26c1b55cfca | 880 | |
DieterGraef | 0:d26c1b55cfca | 881 | if (flags & TCP_ACK) { |
DieterGraef | 0:d26c1b55cfca | 882 | right_wnd_edge = pcb->snd_wnd + pcb->snd_wl2; |
DieterGraef | 0:d26c1b55cfca | 883 | |
DieterGraef | 0:d26c1b55cfca | 884 | /* Update window. */ |
DieterGraef | 0:d26c1b55cfca | 885 | if (TCP_SEQ_LT(pcb->snd_wl1, seqno) || |
DieterGraef | 0:d26c1b55cfca | 886 | (pcb->snd_wl1 == seqno && TCP_SEQ_LT(pcb->snd_wl2, ackno)) || |
DieterGraef | 0:d26c1b55cfca | 887 | (pcb->snd_wl2 == ackno && tcphdr->wnd > pcb->snd_wnd)) { |
DieterGraef | 0:d26c1b55cfca | 888 | pcb->snd_wnd = tcphdr->wnd; |
DieterGraef | 0:d26c1b55cfca | 889 | /* keep track of the biggest window announced by the remote host to calculate |
DieterGraef | 0:d26c1b55cfca | 890 | the maximum segment size */ |
DieterGraef | 0:d26c1b55cfca | 891 | if (pcb->snd_wnd_max < tcphdr->wnd) { |
DieterGraef | 0:d26c1b55cfca | 892 | pcb->snd_wnd_max = tcphdr->wnd; |
DieterGraef | 0:d26c1b55cfca | 893 | } |
DieterGraef | 0:d26c1b55cfca | 894 | pcb->snd_wl1 = seqno; |
DieterGraef | 0:d26c1b55cfca | 895 | pcb->snd_wl2 = ackno; |
DieterGraef | 0:d26c1b55cfca | 896 | if (pcb->snd_wnd == 0) { |
DieterGraef | 0:d26c1b55cfca | 897 | if (pcb->persist_backoff == 0) { |
DieterGraef | 0:d26c1b55cfca | 898 | /* start persist timer */ |
DieterGraef | 0:d26c1b55cfca | 899 | pcb->persist_cnt = 0; |
DieterGraef | 0:d26c1b55cfca | 900 | pcb->persist_backoff = 1; |
DieterGraef | 0:d26c1b55cfca | 901 | } |
DieterGraef | 0:d26c1b55cfca | 902 | } else if (pcb->persist_backoff > 0) { |
DieterGraef | 0:d26c1b55cfca | 903 | /* stop persist timer */ |
DieterGraef | 0:d26c1b55cfca | 904 | pcb->persist_backoff = 0; |
DieterGraef | 0:d26c1b55cfca | 905 | } |
DieterGraef | 0:d26c1b55cfca | 906 | LWIP_DEBUGF(TCP_WND_DEBUG, ("tcp_receive: window update %"U16_F"\n", pcb->snd_wnd)); |
DieterGraef | 0:d26c1b55cfca | 907 | #if TCP_WND_DEBUG |
DieterGraef | 0:d26c1b55cfca | 908 | } else { |
DieterGraef | 0:d26c1b55cfca | 909 | if (pcb->snd_wnd != tcphdr->wnd) { |
DieterGraef | 0:d26c1b55cfca | 910 | LWIP_DEBUGF(TCP_WND_DEBUG, |
DieterGraef | 0:d26c1b55cfca | 911 | ("tcp_receive: no window update lastack %"U32_F" ackno %" |
DieterGraef | 0:d26c1b55cfca | 912 | U32_F" wl1 %"U32_F" seqno %"U32_F" wl2 %"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 913 | pcb->lastack, ackno, pcb->snd_wl1, seqno, pcb->snd_wl2)); |
DieterGraef | 0:d26c1b55cfca | 914 | } |
DieterGraef | 0:d26c1b55cfca | 915 | #endif /* TCP_WND_DEBUG */ |
DieterGraef | 0:d26c1b55cfca | 916 | } |
DieterGraef | 0:d26c1b55cfca | 917 | |
DieterGraef | 0:d26c1b55cfca | 918 | /* (From Stevens TCP/IP Illustrated Vol II, p970.) Its only a |
DieterGraef | 0:d26c1b55cfca | 919 | * duplicate ack if: |
DieterGraef | 0:d26c1b55cfca | 920 | * 1) It doesn't ACK new data |
DieterGraef | 0:d26c1b55cfca | 921 | * 2) length of received packet is zero (i.e. no payload) |
DieterGraef | 0:d26c1b55cfca | 922 | * 3) the advertised window hasn't changed |
DieterGraef | 0:d26c1b55cfca | 923 | * 4) There is outstanding unacknowledged data (retransmission timer running) |
DieterGraef | 0:d26c1b55cfca | 924 | * 5) The ACK is == biggest ACK sequence number so far seen (snd_una) |
DieterGraef | 0:d26c1b55cfca | 925 | * |
DieterGraef | 0:d26c1b55cfca | 926 | * If it passes all five, should process as a dupack: |
DieterGraef | 0:d26c1b55cfca | 927 | * a) dupacks < 3: do nothing |
DieterGraef | 0:d26c1b55cfca | 928 | * b) dupacks == 3: fast retransmit |
DieterGraef | 0:d26c1b55cfca | 929 | * c) dupacks > 3: increase cwnd |
DieterGraef | 0:d26c1b55cfca | 930 | * |
DieterGraef | 0:d26c1b55cfca | 931 | * If it only passes 1-3, should reset dupack counter (and add to |
DieterGraef | 0:d26c1b55cfca | 932 | * stats, which we don't do in lwIP) |
DieterGraef | 0:d26c1b55cfca | 933 | * |
DieterGraef | 0:d26c1b55cfca | 934 | * If it only passes 1, should reset dupack counter |
DieterGraef | 0:d26c1b55cfca | 935 | * |
DieterGraef | 0:d26c1b55cfca | 936 | */ |
DieterGraef | 0:d26c1b55cfca | 937 | |
DieterGraef | 0:d26c1b55cfca | 938 | /* Clause 1 */ |
DieterGraef | 0:d26c1b55cfca | 939 | if (TCP_SEQ_LEQ(ackno, pcb->lastack)) { |
DieterGraef | 0:d26c1b55cfca | 940 | pcb->acked = 0; |
DieterGraef | 0:d26c1b55cfca | 941 | /* Clause 2 */ |
DieterGraef | 0:d26c1b55cfca | 942 | if (tcplen == 0) { |
DieterGraef | 0:d26c1b55cfca | 943 | /* Clause 3 */ |
DieterGraef | 0:d26c1b55cfca | 944 | if (pcb->snd_wl2 + pcb->snd_wnd == right_wnd_edge){ |
DieterGraef | 0:d26c1b55cfca | 945 | /* Clause 4 */ |
DieterGraef | 0:d26c1b55cfca | 946 | if (pcb->rtime >= 0) { |
DieterGraef | 0:d26c1b55cfca | 947 | /* Clause 5 */ |
DieterGraef | 0:d26c1b55cfca | 948 | if (pcb->lastack == ackno) { |
DieterGraef | 0:d26c1b55cfca | 949 | found_dupack = 1; |
DieterGraef | 0:d26c1b55cfca | 950 | if ((u8_t)(pcb->dupacks + 1) > pcb->dupacks) { |
DieterGraef | 0:d26c1b55cfca | 951 | ++pcb->dupacks; |
DieterGraef | 0:d26c1b55cfca | 952 | } |
DieterGraef | 0:d26c1b55cfca | 953 | if (pcb->dupacks > 3) { |
DieterGraef | 0:d26c1b55cfca | 954 | /* Inflate the congestion window, but not if it means that |
DieterGraef | 0:d26c1b55cfca | 955 | the value overflows. */ |
DieterGraef | 0:d26c1b55cfca | 956 | if ((u16_t)(pcb->cwnd + pcb->mss) > pcb->cwnd) { |
DieterGraef | 0:d26c1b55cfca | 957 | pcb->cwnd += pcb->mss; |
DieterGraef | 0:d26c1b55cfca | 958 | } |
DieterGraef | 0:d26c1b55cfca | 959 | } else if (pcb->dupacks == 3) { |
DieterGraef | 0:d26c1b55cfca | 960 | /* Do fast retransmit */ |
DieterGraef | 0:d26c1b55cfca | 961 | tcp_rexmit_fast(pcb); |
DieterGraef | 0:d26c1b55cfca | 962 | } |
DieterGraef | 0:d26c1b55cfca | 963 | } |
DieterGraef | 0:d26c1b55cfca | 964 | } |
DieterGraef | 0:d26c1b55cfca | 965 | } |
DieterGraef | 0:d26c1b55cfca | 966 | } |
DieterGraef | 0:d26c1b55cfca | 967 | /* If Clause (1) or more is true, but not a duplicate ack, reset |
DieterGraef | 0:d26c1b55cfca | 968 | * count of consecutive duplicate acks */ |
DieterGraef | 0:d26c1b55cfca | 969 | if (!found_dupack) { |
DieterGraef | 0:d26c1b55cfca | 970 | pcb->dupacks = 0; |
DieterGraef | 0:d26c1b55cfca | 971 | } |
DieterGraef | 0:d26c1b55cfca | 972 | } else if (TCP_SEQ_BETWEEN(ackno, pcb->lastack+1, pcb->snd_nxt)){ |
DieterGraef | 0:d26c1b55cfca | 973 | /* We come here when the ACK acknowledges new data. */ |
DieterGraef | 0:d26c1b55cfca | 974 | |
DieterGraef | 0:d26c1b55cfca | 975 | /* Reset the "IN Fast Retransmit" flag, since we are no longer |
DieterGraef | 0:d26c1b55cfca | 976 | in fast retransmit. Also reset the congestion window to the |
DieterGraef | 0:d26c1b55cfca | 977 | slow start threshold. */ |
DieterGraef | 0:d26c1b55cfca | 978 | if (pcb->flags & TF_INFR) { |
DieterGraef | 0:d26c1b55cfca | 979 | pcb->flags &= ~TF_INFR; |
DieterGraef | 0:d26c1b55cfca | 980 | pcb->cwnd = pcb->ssthresh; |
DieterGraef | 0:d26c1b55cfca | 981 | } |
DieterGraef | 0:d26c1b55cfca | 982 | |
DieterGraef | 0:d26c1b55cfca | 983 | /* Reset the number of retransmissions. */ |
DieterGraef | 0:d26c1b55cfca | 984 | pcb->nrtx = 0; |
DieterGraef | 0:d26c1b55cfca | 985 | |
DieterGraef | 0:d26c1b55cfca | 986 | /* Reset the retransmission time-out. */ |
DieterGraef | 0:d26c1b55cfca | 987 | pcb->rto = (pcb->sa >> 3) + pcb->sv; |
DieterGraef | 0:d26c1b55cfca | 988 | |
DieterGraef | 0:d26c1b55cfca | 989 | /* Update the send buffer space. Diff between the two can never exceed 64K? */ |
DieterGraef | 0:d26c1b55cfca | 990 | pcb->acked = (u16_t)(ackno - pcb->lastack); |
DieterGraef | 0:d26c1b55cfca | 991 | |
DieterGraef | 0:d26c1b55cfca | 992 | pcb->snd_buf += pcb->acked; |
DieterGraef | 0:d26c1b55cfca | 993 | |
DieterGraef | 0:d26c1b55cfca | 994 | /* Reset the fast retransmit variables. */ |
DieterGraef | 0:d26c1b55cfca | 995 | pcb->dupacks = 0; |
DieterGraef | 0:d26c1b55cfca | 996 | pcb->lastack = ackno; |
DieterGraef | 0:d26c1b55cfca | 997 | |
DieterGraef | 0:d26c1b55cfca | 998 | /* Update the congestion control variables (cwnd and |
DieterGraef | 0:d26c1b55cfca | 999 | ssthresh). */ |
DieterGraef | 0:d26c1b55cfca | 1000 | if (pcb->state >= ESTABLISHED) { |
DieterGraef | 0:d26c1b55cfca | 1001 | if (pcb->cwnd < pcb->ssthresh) { |
DieterGraef | 0:d26c1b55cfca | 1002 | if ((u16_t)(pcb->cwnd + pcb->mss) > pcb->cwnd) { |
DieterGraef | 0:d26c1b55cfca | 1003 | pcb->cwnd += pcb->mss; |
DieterGraef | 0:d26c1b55cfca | 1004 | } |
DieterGraef | 0:d26c1b55cfca | 1005 | LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_receive: slow start cwnd %"U16_F"\n", pcb->cwnd)); |
DieterGraef | 0:d26c1b55cfca | 1006 | } else { |
DieterGraef | 0:d26c1b55cfca | 1007 | u16_t new_cwnd = (pcb->cwnd + pcb->mss * pcb->mss / pcb->cwnd); |
DieterGraef | 0:d26c1b55cfca | 1008 | if (new_cwnd > pcb->cwnd) { |
DieterGraef | 0:d26c1b55cfca | 1009 | pcb->cwnd = new_cwnd; |
DieterGraef | 0:d26c1b55cfca | 1010 | } |
DieterGraef | 0:d26c1b55cfca | 1011 | LWIP_DEBUGF(TCP_CWND_DEBUG, ("tcp_receive: congestion avoidance cwnd %"U16_F"\n", pcb->cwnd)); |
DieterGraef | 0:d26c1b55cfca | 1012 | } |
DieterGraef | 0:d26c1b55cfca | 1013 | } |
DieterGraef | 0:d26c1b55cfca | 1014 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: ACK for %"U32_F", unacked->seqno %"U32_F":%"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 1015 | ackno, |
DieterGraef | 0:d26c1b55cfca | 1016 | pcb->unacked != NULL? |
DieterGraef | 0:d26c1b55cfca | 1017 | ntohl(pcb->unacked->tcphdr->seqno): 0, |
DieterGraef | 0:d26c1b55cfca | 1018 | pcb->unacked != NULL? |
DieterGraef | 0:d26c1b55cfca | 1019 | ntohl(pcb->unacked->tcphdr->seqno) + TCP_TCPLEN(pcb->unacked): 0)); |
DieterGraef | 0:d26c1b55cfca | 1020 | |
DieterGraef | 0:d26c1b55cfca | 1021 | /* Remove segment from the unacknowledged list if the incoming |
DieterGraef | 0:d26c1b55cfca | 1022 | ACK acknowlegdes them. */ |
DieterGraef | 0:d26c1b55cfca | 1023 | while (pcb->unacked != NULL && |
DieterGraef | 0:d26c1b55cfca | 1024 | TCP_SEQ_LEQ(ntohl(pcb->unacked->tcphdr->seqno) + |
DieterGraef | 0:d26c1b55cfca | 1025 | TCP_TCPLEN(pcb->unacked), ackno)) { |
DieterGraef | 0:d26c1b55cfca | 1026 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: removing %"U32_F":%"U32_F" from pcb->unacked\n", |
DieterGraef | 0:d26c1b55cfca | 1027 | ntohl(pcb->unacked->tcphdr->seqno), |
DieterGraef | 0:d26c1b55cfca | 1028 | ntohl(pcb->unacked->tcphdr->seqno) + |
DieterGraef | 0:d26c1b55cfca | 1029 | TCP_TCPLEN(pcb->unacked))); |
DieterGraef | 0:d26c1b55cfca | 1030 | |
DieterGraef | 0:d26c1b55cfca | 1031 | next = pcb->unacked; |
DieterGraef | 0:d26c1b55cfca | 1032 | pcb->unacked = pcb->unacked->next; |
DieterGraef | 0:d26c1b55cfca | 1033 | |
DieterGraef | 0:d26c1b55cfca | 1034 | LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_receive: queuelen %"U16_F" ... ", (u16_t)pcb->snd_queuelen)); |
DieterGraef | 0:d26c1b55cfca | 1035 | LWIP_ASSERT("pcb->snd_queuelen >= pbuf_clen(next->p)", (pcb->snd_queuelen >= pbuf_clen(next->p))); |
DieterGraef | 0:d26c1b55cfca | 1036 | /* Prevent ACK for FIN to generate a sent event */ |
DieterGraef | 0:d26c1b55cfca | 1037 | if ((pcb->acked != 0) && ((TCPH_FLAGS(next->tcphdr) & TCP_FIN) != 0)) { |
DieterGraef | 0:d26c1b55cfca | 1038 | pcb->acked--; |
DieterGraef | 0:d26c1b55cfca | 1039 | } |
DieterGraef | 0:d26c1b55cfca | 1040 | |
DieterGraef | 0:d26c1b55cfca | 1041 | pcb->snd_queuelen -= pbuf_clen(next->p); |
DieterGraef | 0:d26c1b55cfca | 1042 | tcp_seg_free(next); |
DieterGraef | 0:d26c1b55cfca | 1043 | |
DieterGraef | 0:d26c1b55cfca | 1044 | LWIP_DEBUGF(TCP_QLEN_DEBUG, ("%"U16_F" (after freeing unacked)\n", (u16_t)pcb->snd_queuelen)); |
DieterGraef | 0:d26c1b55cfca | 1045 | if (pcb->snd_queuelen != 0) { |
DieterGraef | 0:d26c1b55cfca | 1046 | LWIP_ASSERT("tcp_receive: valid queue length", pcb->unacked != NULL || |
DieterGraef | 0:d26c1b55cfca | 1047 | pcb->unsent != NULL); |
DieterGraef | 0:d26c1b55cfca | 1048 | } |
DieterGraef | 0:d26c1b55cfca | 1049 | } |
DieterGraef | 0:d26c1b55cfca | 1050 | |
DieterGraef | 0:d26c1b55cfca | 1051 | /* If there's nothing left to acknowledge, stop the retransmit |
DieterGraef | 0:d26c1b55cfca | 1052 | timer, otherwise reset it to start again */ |
DieterGraef | 0:d26c1b55cfca | 1053 | if(pcb->unacked == NULL) |
DieterGraef | 0:d26c1b55cfca | 1054 | pcb->rtime = -1; |
DieterGraef | 0:d26c1b55cfca | 1055 | else |
DieterGraef | 0:d26c1b55cfca | 1056 | pcb->rtime = 0; |
DieterGraef | 0:d26c1b55cfca | 1057 | |
DieterGraef | 0:d26c1b55cfca | 1058 | pcb->polltmr = 0; |
DieterGraef | 0:d26c1b55cfca | 1059 | } else { |
DieterGraef | 0:d26c1b55cfca | 1060 | /* Fix bug bug #21582: out of sequence ACK, didn't really ack anything */ |
DieterGraef | 0:d26c1b55cfca | 1061 | pcb->acked = 0; |
DieterGraef | 0:d26c1b55cfca | 1062 | } |
DieterGraef | 0:d26c1b55cfca | 1063 | |
DieterGraef | 0:d26c1b55cfca | 1064 | /* We go through the ->unsent list to see if any of the segments |
DieterGraef | 0:d26c1b55cfca | 1065 | on the list are acknowledged by the ACK. This may seem |
DieterGraef | 0:d26c1b55cfca | 1066 | strange since an "unsent" segment shouldn't be acked. The |
DieterGraef | 0:d26c1b55cfca | 1067 | rationale is that lwIP puts all outstanding segments on the |
DieterGraef | 0:d26c1b55cfca | 1068 | ->unsent list after a retransmission, so these segments may |
DieterGraef | 0:d26c1b55cfca | 1069 | in fact have been sent once. */ |
DieterGraef | 0:d26c1b55cfca | 1070 | while (pcb->unsent != NULL && |
DieterGraef | 0:d26c1b55cfca | 1071 | TCP_SEQ_BETWEEN(ackno, ntohl(pcb->unsent->tcphdr->seqno) + |
DieterGraef | 0:d26c1b55cfca | 1072 | TCP_TCPLEN(pcb->unsent), pcb->snd_nxt)) { |
DieterGraef | 0:d26c1b55cfca | 1073 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: removing %"U32_F":%"U32_F" from pcb->unsent\n", |
DieterGraef | 0:d26c1b55cfca | 1074 | ntohl(pcb->unsent->tcphdr->seqno), ntohl(pcb->unsent->tcphdr->seqno) + |
DieterGraef | 0:d26c1b55cfca | 1075 | TCP_TCPLEN(pcb->unsent))); |
DieterGraef | 0:d26c1b55cfca | 1076 | |
DieterGraef | 0:d26c1b55cfca | 1077 | next = pcb->unsent; |
DieterGraef | 0:d26c1b55cfca | 1078 | pcb->unsent = pcb->unsent->next; |
DieterGraef | 0:d26c1b55cfca | 1079 | #if TCP_OVERSIZE |
DieterGraef | 0:d26c1b55cfca | 1080 | if (pcb->unsent == NULL) { |
DieterGraef | 0:d26c1b55cfca | 1081 | pcb->unsent_oversize = 0; |
DieterGraef | 0:d26c1b55cfca | 1082 | } |
DieterGraef | 0:d26c1b55cfca | 1083 | #endif /* TCP_OVERSIZE */ |
DieterGraef | 0:d26c1b55cfca | 1084 | LWIP_DEBUGF(TCP_QLEN_DEBUG, ("tcp_receive: queuelen %"U16_F" ... ", (u16_t)pcb->snd_queuelen)); |
DieterGraef | 0:d26c1b55cfca | 1085 | LWIP_ASSERT("pcb->snd_queuelen >= pbuf_clen(next->p)", (pcb->snd_queuelen >= pbuf_clen(next->p))); |
DieterGraef | 0:d26c1b55cfca | 1086 | /* Prevent ACK for FIN to generate a sent event */ |
DieterGraef | 0:d26c1b55cfca | 1087 | if ((pcb->acked != 0) && ((TCPH_FLAGS(next->tcphdr) & TCP_FIN) != 0)) { |
DieterGraef | 0:d26c1b55cfca | 1088 | pcb->acked--; |
DieterGraef | 0:d26c1b55cfca | 1089 | } |
DieterGraef | 0:d26c1b55cfca | 1090 | pcb->snd_queuelen -= pbuf_clen(next->p); |
DieterGraef | 0:d26c1b55cfca | 1091 | tcp_seg_free(next); |
DieterGraef | 0:d26c1b55cfca | 1092 | LWIP_DEBUGF(TCP_QLEN_DEBUG, ("%"U16_F" (after freeing unsent)\n", (u16_t)pcb->snd_queuelen)); |
DieterGraef | 0:d26c1b55cfca | 1093 | if (pcb->snd_queuelen != 0) { |
DieterGraef | 0:d26c1b55cfca | 1094 | LWIP_ASSERT("tcp_receive: valid queue length", |
DieterGraef | 0:d26c1b55cfca | 1095 | pcb->unacked != NULL || pcb->unsent != NULL); |
DieterGraef | 0:d26c1b55cfca | 1096 | } |
DieterGraef | 0:d26c1b55cfca | 1097 | } |
DieterGraef | 0:d26c1b55cfca | 1098 | /* End of ACK for new data processing. */ |
DieterGraef | 0:d26c1b55cfca | 1099 | |
DieterGraef | 0:d26c1b55cfca | 1100 | LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_receive: pcb->rttest %"U32_F" rtseq %"U32_F" ackno %"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 1101 | pcb->rttest, pcb->rtseq, ackno)); |
DieterGraef | 0:d26c1b55cfca | 1102 | |
DieterGraef | 0:d26c1b55cfca | 1103 | /* RTT estimation calculations. This is done by checking if the |
DieterGraef | 0:d26c1b55cfca | 1104 | incoming segment acknowledges the segment we use to take a |
DieterGraef | 0:d26c1b55cfca | 1105 | round-trip time measurement. */ |
DieterGraef | 0:d26c1b55cfca | 1106 | if (pcb->rttest && TCP_SEQ_LT(pcb->rtseq, ackno)) { |
DieterGraef | 0:d26c1b55cfca | 1107 | /* diff between this shouldn't exceed 32K since this are tcp timer ticks |
DieterGraef | 0:d26c1b55cfca | 1108 | and a round-trip shouldn't be that long... */ |
DieterGraef | 0:d26c1b55cfca | 1109 | m = (s16_t)(tcp_ticks - pcb->rttest); |
DieterGraef | 0:d26c1b55cfca | 1110 | |
DieterGraef | 0:d26c1b55cfca | 1111 | LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_receive: experienced rtt %"U16_F" ticks (%"U16_F" msec).\n", |
DieterGraef | 0:d26c1b55cfca | 1112 | m, m * TCP_SLOW_INTERVAL)); |
DieterGraef | 0:d26c1b55cfca | 1113 | |
DieterGraef | 0:d26c1b55cfca | 1114 | /* This is taken directly from VJs original code in his paper */ |
DieterGraef | 0:d26c1b55cfca | 1115 | m = m - (pcb->sa >> 3); |
DieterGraef | 0:d26c1b55cfca | 1116 | pcb->sa += m; |
DieterGraef | 0:d26c1b55cfca | 1117 | if (m < 0) { |
DieterGraef | 0:d26c1b55cfca | 1118 | m = -m; |
DieterGraef | 0:d26c1b55cfca | 1119 | } |
DieterGraef | 0:d26c1b55cfca | 1120 | m = m - (pcb->sv >> 2); |
DieterGraef | 0:d26c1b55cfca | 1121 | pcb->sv += m; |
DieterGraef | 0:d26c1b55cfca | 1122 | pcb->rto = (pcb->sa >> 3) + pcb->sv; |
DieterGraef | 0:d26c1b55cfca | 1123 | |
DieterGraef | 0:d26c1b55cfca | 1124 | LWIP_DEBUGF(TCP_RTO_DEBUG, ("tcp_receive: RTO %"U16_F" (%"U16_F" milliseconds)\n", |
DieterGraef | 0:d26c1b55cfca | 1125 | pcb->rto, pcb->rto * TCP_SLOW_INTERVAL)); |
DieterGraef | 0:d26c1b55cfca | 1126 | |
DieterGraef | 0:d26c1b55cfca | 1127 | pcb->rttest = 0; |
DieterGraef | 0:d26c1b55cfca | 1128 | } |
DieterGraef | 0:d26c1b55cfca | 1129 | } |
DieterGraef | 0:d26c1b55cfca | 1130 | |
DieterGraef | 0:d26c1b55cfca | 1131 | /* If the incoming segment contains data, we must process it |
DieterGraef | 0:d26c1b55cfca | 1132 | further unless the pcb already received a FIN. |
DieterGraef | 0:d26c1b55cfca | 1133 | (RFC 793, chapeter 3.9, "SEGMENT ARRIVES" in states CLOSE-WAIT, CLOSING, |
DieterGraef | 0:d26c1b55cfca | 1134 | LAST-ACK and TIME-WAIT: "Ignore the segment text.") */ |
DieterGraef | 0:d26c1b55cfca | 1135 | if ((tcplen > 0) && (pcb->state < CLOSE_WAIT)) { |
DieterGraef | 0:d26c1b55cfca | 1136 | /* This code basically does three things: |
DieterGraef | 0:d26c1b55cfca | 1137 | |
DieterGraef | 0:d26c1b55cfca | 1138 | +) If the incoming segment contains data that is the next |
DieterGraef | 0:d26c1b55cfca | 1139 | in-sequence data, this data is passed to the application. This |
DieterGraef | 0:d26c1b55cfca | 1140 | might involve trimming the first edge of the data. The rcv_nxt |
DieterGraef | 0:d26c1b55cfca | 1141 | variable and the advertised window are adjusted. |
DieterGraef | 0:d26c1b55cfca | 1142 | |
DieterGraef | 0:d26c1b55cfca | 1143 | +) If the incoming segment has data that is above the next |
DieterGraef | 0:d26c1b55cfca | 1144 | sequence number expected (->rcv_nxt), the segment is placed on |
DieterGraef | 0:d26c1b55cfca | 1145 | the ->ooseq queue. This is done by finding the appropriate |
DieterGraef | 0:d26c1b55cfca | 1146 | place in the ->ooseq queue (which is ordered by sequence |
DieterGraef | 0:d26c1b55cfca | 1147 | number) and trim the segment in both ends if needed. An |
DieterGraef | 0:d26c1b55cfca | 1148 | immediate ACK is sent to indicate that we received an |
DieterGraef | 0:d26c1b55cfca | 1149 | out-of-sequence segment. |
DieterGraef | 0:d26c1b55cfca | 1150 | |
DieterGraef | 0:d26c1b55cfca | 1151 | +) Finally, we check if the first segment on the ->ooseq queue |
DieterGraef | 0:d26c1b55cfca | 1152 | now is in sequence (i.e., if rcv_nxt >= ooseq->seqno). If |
DieterGraef | 0:d26c1b55cfca | 1153 | rcv_nxt > ooseq->seqno, we must trim the first edge of the |
DieterGraef | 0:d26c1b55cfca | 1154 | segment on ->ooseq before we adjust rcv_nxt. The data in the |
DieterGraef | 0:d26c1b55cfca | 1155 | segments that are now on sequence are chained onto the |
DieterGraef | 0:d26c1b55cfca | 1156 | incoming segment so that we only need to call the application |
DieterGraef | 0:d26c1b55cfca | 1157 | once. |
DieterGraef | 0:d26c1b55cfca | 1158 | */ |
DieterGraef | 0:d26c1b55cfca | 1159 | |
DieterGraef | 0:d26c1b55cfca | 1160 | /* First, we check if we must trim the first edge. We have to do |
DieterGraef | 0:d26c1b55cfca | 1161 | this if the sequence number of the incoming segment is less |
DieterGraef | 0:d26c1b55cfca | 1162 | than rcv_nxt, and the sequence number plus the length of the |
DieterGraef | 0:d26c1b55cfca | 1163 | segment is larger than rcv_nxt. */ |
DieterGraef | 0:d26c1b55cfca | 1164 | /* if (TCP_SEQ_LT(seqno, pcb->rcv_nxt)){ |
DieterGraef | 0:d26c1b55cfca | 1165 | if (TCP_SEQ_LT(pcb->rcv_nxt, seqno + tcplen)) {*/ |
DieterGraef | 0:d26c1b55cfca | 1166 | if (TCP_SEQ_BETWEEN(pcb->rcv_nxt, seqno + 1, seqno + tcplen - 1)){ |
DieterGraef | 0:d26c1b55cfca | 1167 | /* Trimming the first edge is done by pushing the payload |
DieterGraef | 0:d26c1b55cfca | 1168 | pointer in the pbuf downwards. This is somewhat tricky since |
DieterGraef | 0:d26c1b55cfca | 1169 | we do not want to discard the full contents of the pbuf up to |
DieterGraef | 0:d26c1b55cfca | 1170 | the new starting point of the data since we have to keep the |
DieterGraef | 0:d26c1b55cfca | 1171 | TCP header which is present in the first pbuf in the chain. |
DieterGraef | 0:d26c1b55cfca | 1172 | |
DieterGraef | 0:d26c1b55cfca | 1173 | What is done is really quite a nasty hack: the first pbuf in |
DieterGraef | 0:d26c1b55cfca | 1174 | the pbuf chain is pointed to by inseg.p. Since we need to be |
DieterGraef | 0:d26c1b55cfca | 1175 | able to deallocate the whole pbuf, we cannot change this |
DieterGraef | 0:d26c1b55cfca | 1176 | inseg.p pointer to point to any of the later pbufs in the |
DieterGraef | 0:d26c1b55cfca | 1177 | chain. Instead, we point the ->payload pointer in the first |
DieterGraef | 0:d26c1b55cfca | 1178 | pbuf to data in one of the later pbufs. We also set the |
DieterGraef | 0:d26c1b55cfca | 1179 | inseg.data pointer to point to the right place. This way, the |
DieterGraef | 0:d26c1b55cfca | 1180 | ->p pointer will still point to the first pbuf, but the |
DieterGraef | 0:d26c1b55cfca | 1181 | ->p->payload pointer will point to data in another pbuf. |
DieterGraef | 0:d26c1b55cfca | 1182 | |
DieterGraef | 0:d26c1b55cfca | 1183 | After we are done with adjusting the pbuf pointers we must |
DieterGraef | 0:d26c1b55cfca | 1184 | adjust the ->data pointer in the seg and the segment |
DieterGraef | 0:d26c1b55cfca | 1185 | length.*/ |
DieterGraef | 0:d26c1b55cfca | 1186 | |
DieterGraef | 0:d26c1b55cfca | 1187 | off = pcb->rcv_nxt - seqno; |
DieterGraef | 0:d26c1b55cfca | 1188 | p = inseg.p; |
DieterGraef | 0:d26c1b55cfca | 1189 | LWIP_ASSERT("inseg.p != NULL", inseg.p); |
DieterGraef | 0:d26c1b55cfca | 1190 | LWIP_ASSERT("insane offset!", (off < 0x7fff)); |
DieterGraef | 0:d26c1b55cfca | 1191 | if (inseg.p->len < off) { |
DieterGraef | 0:d26c1b55cfca | 1192 | LWIP_ASSERT("pbuf too short!", (((s32_t)inseg.p->tot_len) >= off)); |
DieterGraef | 0:d26c1b55cfca | 1193 | new_tot_len = (u16_t)(inseg.p->tot_len - off); |
DieterGraef | 0:d26c1b55cfca | 1194 | while (p->len < off) { |
DieterGraef | 0:d26c1b55cfca | 1195 | off -= p->len; |
DieterGraef | 0:d26c1b55cfca | 1196 | /* KJM following line changed (with addition of new_tot_len var) |
DieterGraef | 0:d26c1b55cfca | 1197 | to fix bug #9076 |
DieterGraef | 0:d26c1b55cfca | 1198 | inseg.p->tot_len -= p->len; */ |
DieterGraef | 0:d26c1b55cfca | 1199 | p->tot_len = new_tot_len; |
DieterGraef | 0:d26c1b55cfca | 1200 | p->len = 0; |
DieterGraef | 0:d26c1b55cfca | 1201 | p = p->next; |
DieterGraef | 0:d26c1b55cfca | 1202 | } |
DieterGraef | 0:d26c1b55cfca | 1203 | if(pbuf_header(p, (s16_t)-off)) { |
DieterGraef | 0:d26c1b55cfca | 1204 | /* Do we need to cope with this failing? Assert for now */ |
DieterGraef | 0:d26c1b55cfca | 1205 | LWIP_ASSERT("pbuf_header failed", 0); |
DieterGraef | 0:d26c1b55cfca | 1206 | } |
DieterGraef | 0:d26c1b55cfca | 1207 | } else { |
DieterGraef | 0:d26c1b55cfca | 1208 | if(pbuf_header(inseg.p, (s16_t)-off)) { |
DieterGraef | 0:d26c1b55cfca | 1209 | /* Do we need to cope with this failing? Assert for now */ |
DieterGraef | 0:d26c1b55cfca | 1210 | LWIP_ASSERT("pbuf_header failed", 0); |
DieterGraef | 0:d26c1b55cfca | 1211 | } |
DieterGraef | 0:d26c1b55cfca | 1212 | } |
DieterGraef | 0:d26c1b55cfca | 1213 | inseg.len -= (u16_t)(pcb->rcv_nxt - seqno); |
DieterGraef | 0:d26c1b55cfca | 1214 | inseg.tcphdr->seqno = seqno = pcb->rcv_nxt; |
DieterGraef | 0:d26c1b55cfca | 1215 | } |
DieterGraef | 0:d26c1b55cfca | 1216 | else { |
DieterGraef | 0:d26c1b55cfca | 1217 | if (TCP_SEQ_LT(seqno, pcb->rcv_nxt)){ |
DieterGraef | 0:d26c1b55cfca | 1218 | /* the whole segment is < rcv_nxt */ |
DieterGraef | 0:d26c1b55cfca | 1219 | /* must be a duplicate of a packet that has already been correctly handled */ |
DieterGraef | 0:d26c1b55cfca | 1220 | |
DieterGraef | 0:d26c1b55cfca | 1221 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: duplicate seqno %"U32_F"\n", seqno)); |
DieterGraef | 0:d26c1b55cfca | 1222 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 1223 | } |
DieterGraef | 0:d26c1b55cfca | 1224 | } |
DieterGraef | 0:d26c1b55cfca | 1225 | |
DieterGraef | 0:d26c1b55cfca | 1226 | /* The sequence number must be within the window (above rcv_nxt |
DieterGraef | 0:d26c1b55cfca | 1227 | and below rcv_nxt + rcv_wnd) in order to be further |
DieterGraef | 0:d26c1b55cfca | 1228 | processed. */ |
DieterGraef | 0:d26c1b55cfca | 1229 | if (TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, |
DieterGraef | 0:d26c1b55cfca | 1230 | pcb->rcv_nxt + pcb->rcv_wnd - 1)){ |
DieterGraef | 0:d26c1b55cfca | 1231 | if (pcb->rcv_nxt == seqno) { |
DieterGraef | 0:d26c1b55cfca | 1232 | /* The incoming segment is the next in sequence. We check if |
DieterGraef | 0:d26c1b55cfca | 1233 | we have to trim the end of the segment and update rcv_nxt |
DieterGraef | 0:d26c1b55cfca | 1234 | and pass the data to the application. */ |
DieterGraef | 0:d26c1b55cfca | 1235 | tcplen = TCP_TCPLEN(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1236 | |
DieterGraef | 0:d26c1b55cfca | 1237 | if (tcplen > pcb->rcv_wnd) { |
DieterGraef | 0:d26c1b55cfca | 1238 | LWIP_DEBUGF(TCP_INPUT_DEBUG, |
DieterGraef | 0:d26c1b55cfca | 1239 | ("tcp_receive: other end overran receive window" |
DieterGraef | 0:d26c1b55cfca | 1240 | "seqno %"U32_F" len %"U16_F" right edge %"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 1241 | seqno, tcplen, pcb->rcv_nxt + pcb->rcv_wnd)); |
DieterGraef | 0:d26c1b55cfca | 1242 | if (TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 1243 | /* Must remove the FIN from the header as we're trimming |
DieterGraef | 0:d26c1b55cfca | 1244 | * that byte of sequence-space from the packet */ |
DieterGraef | 0:d26c1b55cfca | 1245 | TCPH_FLAGS_SET(inseg.tcphdr, TCPH_FLAGS(inseg.tcphdr) &~ TCP_FIN); |
DieterGraef | 0:d26c1b55cfca | 1246 | } |
DieterGraef | 0:d26c1b55cfca | 1247 | /* Adjust length of segment to fit in the window. */ |
DieterGraef | 0:d26c1b55cfca | 1248 | inseg.len = pcb->rcv_wnd; |
DieterGraef | 0:d26c1b55cfca | 1249 | if (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) { |
DieterGraef | 0:d26c1b55cfca | 1250 | inseg.len -= 1; |
DieterGraef | 0:d26c1b55cfca | 1251 | } |
DieterGraef | 0:d26c1b55cfca | 1252 | pbuf_realloc(inseg.p, inseg.len); |
DieterGraef | 0:d26c1b55cfca | 1253 | tcplen = TCP_TCPLEN(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1254 | LWIP_ASSERT("tcp_receive: segment not trimmed correctly to rcv_wnd\n", |
DieterGraef | 0:d26c1b55cfca | 1255 | (seqno + tcplen) == (pcb->rcv_nxt + pcb->rcv_wnd)); |
DieterGraef | 0:d26c1b55cfca | 1256 | } |
DieterGraef | 0:d26c1b55cfca | 1257 | #if TCP_QUEUE_OOSEQ |
DieterGraef | 0:d26c1b55cfca | 1258 | /* Received in-sequence data, adjust ooseq data if: |
DieterGraef | 0:d26c1b55cfca | 1259 | - FIN has been received or |
DieterGraef | 0:d26c1b55cfca | 1260 | - inseq overlaps with ooseq */ |
DieterGraef | 0:d26c1b55cfca | 1261 | if (pcb->ooseq != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1262 | if (TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 1263 | LWIP_DEBUGF(TCP_INPUT_DEBUG, |
DieterGraef | 0:d26c1b55cfca | 1264 | ("tcp_receive: received in-order FIN, binning ooseq queue\n")); |
DieterGraef | 0:d26c1b55cfca | 1265 | /* Received in-order FIN means anything that was received |
DieterGraef | 0:d26c1b55cfca | 1266 | * out of order must now have been received in-order, so |
DieterGraef | 0:d26c1b55cfca | 1267 | * bin the ooseq queue */ |
DieterGraef | 0:d26c1b55cfca | 1268 | while (pcb->ooseq != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1269 | struct tcp_seg *old_ooseq = pcb->ooseq; |
DieterGraef | 0:d26c1b55cfca | 1270 | pcb->ooseq = pcb->ooseq->next; |
DieterGraef | 0:d26c1b55cfca | 1271 | tcp_seg_free(old_ooseq); |
DieterGraef | 0:d26c1b55cfca | 1272 | } |
DieterGraef | 0:d26c1b55cfca | 1273 | } else { |
DieterGraef | 0:d26c1b55cfca | 1274 | next = pcb->ooseq; |
DieterGraef | 0:d26c1b55cfca | 1275 | /* Remove all segments on ooseq that are covered by inseg already. |
DieterGraef | 0:d26c1b55cfca | 1276 | * FIN is copied from ooseq to inseg if present. */ |
DieterGraef | 0:d26c1b55cfca | 1277 | while (next && |
DieterGraef | 0:d26c1b55cfca | 1278 | TCP_SEQ_GEQ(seqno + tcplen, |
DieterGraef | 0:d26c1b55cfca | 1279 | next->tcphdr->seqno + next->len)) { |
DieterGraef | 0:d26c1b55cfca | 1280 | /* inseg cannot have FIN here (already processed above) */ |
DieterGraef | 0:d26c1b55cfca | 1281 | if (TCPH_FLAGS(next->tcphdr) & TCP_FIN && |
DieterGraef | 0:d26c1b55cfca | 1282 | (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) == 0) { |
DieterGraef | 0:d26c1b55cfca | 1283 | TCPH_SET_FLAG(inseg.tcphdr, TCP_FIN); |
DieterGraef | 0:d26c1b55cfca | 1284 | tcplen = TCP_TCPLEN(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1285 | } |
DieterGraef | 0:d26c1b55cfca | 1286 | prev = next; |
DieterGraef | 0:d26c1b55cfca | 1287 | next = next->next; |
DieterGraef | 0:d26c1b55cfca | 1288 | tcp_seg_free(prev); |
DieterGraef | 0:d26c1b55cfca | 1289 | } |
DieterGraef | 0:d26c1b55cfca | 1290 | /* Now trim right side of inseg if it overlaps with the first |
DieterGraef | 0:d26c1b55cfca | 1291 | * segment on ooseq */ |
DieterGraef | 0:d26c1b55cfca | 1292 | if (next && |
DieterGraef | 0:d26c1b55cfca | 1293 | TCP_SEQ_GT(seqno + tcplen, |
DieterGraef | 0:d26c1b55cfca | 1294 | next->tcphdr->seqno)) { |
DieterGraef | 0:d26c1b55cfca | 1295 | /* inseg cannot have FIN here (already processed above) */ |
DieterGraef | 0:d26c1b55cfca | 1296 | inseg.len = (u16_t)(next->tcphdr->seqno - seqno); |
DieterGraef | 0:d26c1b55cfca | 1297 | if (TCPH_FLAGS(inseg.tcphdr) & TCP_SYN) { |
DieterGraef | 0:d26c1b55cfca | 1298 | inseg.len -= 1; |
DieterGraef | 0:d26c1b55cfca | 1299 | } |
DieterGraef | 0:d26c1b55cfca | 1300 | pbuf_realloc(inseg.p, inseg.len); |
DieterGraef | 0:d26c1b55cfca | 1301 | tcplen = TCP_TCPLEN(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1302 | LWIP_ASSERT("tcp_receive: segment not trimmed correctly to ooseq queue\n", |
DieterGraef | 0:d26c1b55cfca | 1303 | (seqno + tcplen) == next->tcphdr->seqno); |
DieterGraef | 0:d26c1b55cfca | 1304 | } |
DieterGraef | 0:d26c1b55cfca | 1305 | pcb->ooseq = next; |
DieterGraef | 0:d26c1b55cfca | 1306 | } |
DieterGraef | 0:d26c1b55cfca | 1307 | } |
DieterGraef | 0:d26c1b55cfca | 1308 | #endif /* TCP_QUEUE_OOSEQ */ |
DieterGraef | 0:d26c1b55cfca | 1309 | |
DieterGraef | 0:d26c1b55cfca | 1310 | pcb->rcv_nxt = seqno + tcplen; |
DieterGraef | 0:d26c1b55cfca | 1311 | |
DieterGraef | 0:d26c1b55cfca | 1312 | /* Update the receiver's (our) window. */ |
DieterGraef | 0:d26c1b55cfca | 1313 | LWIP_ASSERT("tcp_receive: tcplen > rcv_wnd\n", pcb->rcv_wnd >= tcplen); |
DieterGraef | 0:d26c1b55cfca | 1314 | pcb->rcv_wnd -= tcplen; |
DieterGraef | 0:d26c1b55cfca | 1315 | |
DieterGraef | 0:d26c1b55cfca | 1316 | tcp_update_rcv_ann_wnd(pcb); |
DieterGraef | 0:d26c1b55cfca | 1317 | |
DieterGraef | 0:d26c1b55cfca | 1318 | /* If there is data in the segment, we make preparations to |
DieterGraef | 0:d26c1b55cfca | 1319 | pass this up to the application. The ->recv_data variable |
DieterGraef | 0:d26c1b55cfca | 1320 | is used for holding the pbuf that goes to the |
DieterGraef | 0:d26c1b55cfca | 1321 | application. The code for reassembling out-of-sequence data |
DieterGraef | 0:d26c1b55cfca | 1322 | chains its data on this pbuf as well. |
DieterGraef | 0:d26c1b55cfca | 1323 | |
DieterGraef | 0:d26c1b55cfca | 1324 | If the segment was a FIN, we set the TF_GOT_FIN flag that will |
DieterGraef | 0:d26c1b55cfca | 1325 | be used to indicate to the application that the remote side has |
DieterGraef | 0:d26c1b55cfca | 1326 | closed its end of the connection. */ |
DieterGraef | 0:d26c1b55cfca | 1327 | if (inseg.p->tot_len > 0) { |
DieterGraef | 0:d26c1b55cfca | 1328 | recv_data = inseg.p; |
DieterGraef | 0:d26c1b55cfca | 1329 | /* Since this pbuf now is the responsibility of the |
DieterGraef | 0:d26c1b55cfca | 1330 | application, we delete our reference to it so that we won't |
DieterGraef | 0:d26c1b55cfca | 1331 | (mistakingly) deallocate it. */ |
DieterGraef | 0:d26c1b55cfca | 1332 | inseg.p = NULL; |
DieterGraef | 0:d26c1b55cfca | 1333 | } |
DieterGraef | 0:d26c1b55cfca | 1334 | if (TCPH_FLAGS(inseg.tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 1335 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: received FIN.\n")); |
DieterGraef | 0:d26c1b55cfca | 1336 | recv_flags |= TF_GOT_FIN; |
DieterGraef | 0:d26c1b55cfca | 1337 | } |
DieterGraef | 0:d26c1b55cfca | 1338 | |
DieterGraef | 0:d26c1b55cfca | 1339 | #if TCP_QUEUE_OOSEQ |
DieterGraef | 0:d26c1b55cfca | 1340 | /* We now check if we have segments on the ->ooseq queue that |
DieterGraef | 0:d26c1b55cfca | 1341 | are now in sequence. */ |
DieterGraef | 0:d26c1b55cfca | 1342 | while (pcb->ooseq != NULL && |
DieterGraef | 0:d26c1b55cfca | 1343 | pcb->ooseq->tcphdr->seqno == pcb->rcv_nxt) { |
DieterGraef | 0:d26c1b55cfca | 1344 | |
DieterGraef | 0:d26c1b55cfca | 1345 | cseg = pcb->ooseq; |
DieterGraef | 0:d26c1b55cfca | 1346 | seqno = pcb->ooseq->tcphdr->seqno; |
DieterGraef | 0:d26c1b55cfca | 1347 | |
DieterGraef | 0:d26c1b55cfca | 1348 | pcb->rcv_nxt += TCP_TCPLEN(cseg); |
DieterGraef | 0:d26c1b55cfca | 1349 | LWIP_ASSERT("tcp_receive: ooseq tcplen > rcv_wnd\n", |
DieterGraef | 0:d26c1b55cfca | 1350 | pcb->rcv_wnd >= TCP_TCPLEN(cseg)); |
DieterGraef | 0:d26c1b55cfca | 1351 | pcb->rcv_wnd -= TCP_TCPLEN(cseg); |
DieterGraef | 0:d26c1b55cfca | 1352 | |
DieterGraef | 0:d26c1b55cfca | 1353 | tcp_update_rcv_ann_wnd(pcb); |
DieterGraef | 0:d26c1b55cfca | 1354 | |
DieterGraef | 0:d26c1b55cfca | 1355 | if (cseg->p->tot_len > 0) { |
DieterGraef | 0:d26c1b55cfca | 1356 | /* Chain this pbuf onto the pbuf that we will pass to |
DieterGraef | 0:d26c1b55cfca | 1357 | the application. */ |
DieterGraef | 0:d26c1b55cfca | 1358 | if (recv_data) { |
DieterGraef | 0:d26c1b55cfca | 1359 | pbuf_cat(recv_data, cseg->p); |
DieterGraef | 0:d26c1b55cfca | 1360 | } else { |
DieterGraef | 0:d26c1b55cfca | 1361 | recv_data = cseg->p; |
DieterGraef | 0:d26c1b55cfca | 1362 | } |
DieterGraef | 0:d26c1b55cfca | 1363 | cseg->p = NULL; |
DieterGraef | 0:d26c1b55cfca | 1364 | } |
DieterGraef | 0:d26c1b55cfca | 1365 | if (TCPH_FLAGS(cseg->tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 1366 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_receive: dequeued FIN.\n")); |
DieterGraef | 0:d26c1b55cfca | 1367 | recv_flags |= TF_GOT_FIN; |
DieterGraef | 0:d26c1b55cfca | 1368 | if (pcb->state == ESTABLISHED) { /* force passive close or we can move to active close */ |
DieterGraef | 0:d26c1b55cfca | 1369 | pcb->state = CLOSE_WAIT; |
DieterGraef | 0:d26c1b55cfca | 1370 | } |
DieterGraef | 0:d26c1b55cfca | 1371 | } |
DieterGraef | 0:d26c1b55cfca | 1372 | |
DieterGraef | 0:d26c1b55cfca | 1373 | pcb->ooseq = cseg->next; |
DieterGraef | 0:d26c1b55cfca | 1374 | tcp_seg_free(cseg); |
DieterGraef | 0:d26c1b55cfca | 1375 | } |
DieterGraef | 0:d26c1b55cfca | 1376 | #endif /* TCP_QUEUE_OOSEQ */ |
DieterGraef | 0:d26c1b55cfca | 1377 | |
DieterGraef | 0:d26c1b55cfca | 1378 | |
DieterGraef | 0:d26c1b55cfca | 1379 | /* Acknowledge the segment(s). */ |
DieterGraef | 0:d26c1b55cfca | 1380 | tcp_ack(pcb); |
DieterGraef | 0:d26c1b55cfca | 1381 | |
DieterGraef | 0:d26c1b55cfca | 1382 | } else { |
DieterGraef | 0:d26c1b55cfca | 1383 | /* We get here if the incoming segment is out-of-sequence. */ |
DieterGraef | 0:d26c1b55cfca | 1384 | tcp_send_empty_ack(pcb); |
DieterGraef | 0:d26c1b55cfca | 1385 | #if TCP_QUEUE_OOSEQ |
DieterGraef | 0:d26c1b55cfca | 1386 | /* We queue the segment on the ->ooseq queue. */ |
DieterGraef | 0:d26c1b55cfca | 1387 | if (pcb->ooseq == NULL) { |
DieterGraef | 0:d26c1b55cfca | 1388 | pcb->ooseq = tcp_seg_copy(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1389 | } else { |
DieterGraef | 0:d26c1b55cfca | 1390 | /* If the queue is not empty, we walk through the queue and |
DieterGraef | 0:d26c1b55cfca | 1391 | try to find a place where the sequence number of the |
DieterGraef | 0:d26c1b55cfca | 1392 | incoming segment is between the sequence numbers of the |
DieterGraef | 0:d26c1b55cfca | 1393 | previous and the next segment on the ->ooseq queue. That is |
DieterGraef | 0:d26c1b55cfca | 1394 | the place where we put the incoming segment. If needed, we |
DieterGraef | 0:d26c1b55cfca | 1395 | trim the second edges of the previous and the incoming |
DieterGraef | 0:d26c1b55cfca | 1396 | segment so that it will fit into the sequence. |
DieterGraef | 0:d26c1b55cfca | 1397 | |
DieterGraef | 0:d26c1b55cfca | 1398 | If the incoming segment has the same sequence number as a |
DieterGraef | 0:d26c1b55cfca | 1399 | segment on the ->ooseq queue, we discard the segment that |
DieterGraef | 0:d26c1b55cfca | 1400 | contains less data. */ |
DieterGraef | 0:d26c1b55cfca | 1401 | |
DieterGraef | 0:d26c1b55cfca | 1402 | prev = NULL; |
DieterGraef | 0:d26c1b55cfca | 1403 | for(next = pcb->ooseq; next != NULL; next = next->next) { |
DieterGraef | 0:d26c1b55cfca | 1404 | if (seqno == next->tcphdr->seqno) { |
DieterGraef | 0:d26c1b55cfca | 1405 | /* The sequence number of the incoming segment is the |
DieterGraef | 0:d26c1b55cfca | 1406 | same as the sequence number of the segment on |
DieterGraef | 0:d26c1b55cfca | 1407 | ->ooseq. We check the lengths to see which one to |
DieterGraef | 0:d26c1b55cfca | 1408 | discard. */ |
DieterGraef | 0:d26c1b55cfca | 1409 | if (inseg.len > next->len) { |
DieterGraef | 0:d26c1b55cfca | 1410 | /* The incoming segment is larger than the old |
DieterGraef | 0:d26c1b55cfca | 1411 | segment. We replace some segments with the new |
DieterGraef | 0:d26c1b55cfca | 1412 | one. */ |
DieterGraef | 0:d26c1b55cfca | 1413 | cseg = tcp_seg_copy(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1414 | if (cseg != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1415 | if (prev != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1416 | prev->next = cseg; |
DieterGraef | 0:d26c1b55cfca | 1417 | } else { |
DieterGraef | 0:d26c1b55cfca | 1418 | pcb->ooseq = cseg; |
DieterGraef | 0:d26c1b55cfca | 1419 | } |
DieterGraef | 0:d26c1b55cfca | 1420 | tcp_oos_insert_segment(cseg, next); |
DieterGraef | 0:d26c1b55cfca | 1421 | } |
DieterGraef | 0:d26c1b55cfca | 1422 | break; |
DieterGraef | 0:d26c1b55cfca | 1423 | } else { |
DieterGraef | 0:d26c1b55cfca | 1424 | /* Either the lenghts are the same or the incoming |
DieterGraef | 0:d26c1b55cfca | 1425 | segment was smaller than the old one; in either |
DieterGraef | 0:d26c1b55cfca | 1426 | case, we ditch the incoming segment. */ |
DieterGraef | 0:d26c1b55cfca | 1427 | break; |
DieterGraef | 0:d26c1b55cfca | 1428 | } |
DieterGraef | 0:d26c1b55cfca | 1429 | } else { |
DieterGraef | 0:d26c1b55cfca | 1430 | if (prev == NULL) { |
DieterGraef | 0:d26c1b55cfca | 1431 | if (TCP_SEQ_LT(seqno, next->tcphdr->seqno)) { |
DieterGraef | 0:d26c1b55cfca | 1432 | /* The sequence number of the incoming segment is lower |
DieterGraef | 0:d26c1b55cfca | 1433 | than the sequence number of the first segment on the |
DieterGraef | 0:d26c1b55cfca | 1434 | queue. We put the incoming segment first on the |
DieterGraef | 0:d26c1b55cfca | 1435 | queue. */ |
DieterGraef | 0:d26c1b55cfca | 1436 | cseg = tcp_seg_copy(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1437 | if (cseg != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1438 | pcb->ooseq = cseg; |
DieterGraef | 0:d26c1b55cfca | 1439 | tcp_oos_insert_segment(cseg, next); |
DieterGraef | 0:d26c1b55cfca | 1440 | } |
DieterGraef | 0:d26c1b55cfca | 1441 | break; |
DieterGraef | 0:d26c1b55cfca | 1442 | } |
DieterGraef | 0:d26c1b55cfca | 1443 | } else { |
DieterGraef | 0:d26c1b55cfca | 1444 | /*if (TCP_SEQ_LT(prev->tcphdr->seqno, seqno) && |
DieterGraef | 0:d26c1b55cfca | 1445 | TCP_SEQ_LT(seqno, next->tcphdr->seqno)) {*/ |
DieterGraef | 0:d26c1b55cfca | 1446 | if (TCP_SEQ_BETWEEN(seqno, prev->tcphdr->seqno+1, next->tcphdr->seqno-1)) { |
DieterGraef | 0:d26c1b55cfca | 1447 | /* The sequence number of the incoming segment is in |
DieterGraef | 0:d26c1b55cfca | 1448 | between the sequence numbers of the previous and |
DieterGraef | 0:d26c1b55cfca | 1449 | the next segment on ->ooseq. We trim trim the previous |
DieterGraef | 0:d26c1b55cfca | 1450 | segment, delete next segments that included in received segment |
DieterGraef | 0:d26c1b55cfca | 1451 | and trim received, if needed. */ |
DieterGraef | 0:d26c1b55cfca | 1452 | cseg = tcp_seg_copy(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1453 | if (cseg != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1454 | if (TCP_SEQ_GT(prev->tcphdr->seqno + prev->len, seqno)) { |
DieterGraef | 0:d26c1b55cfca | 1455 | /* We need to trim the prev segment. */ |
DieterGraef | 0:d26c1b55cfca | 1456 | prev->len = (u16_t)(seqno - prev->tcphdr->seqno); |
DieterGraef | 0:d26c1b55cfca | 1457 | pbuf_realloc(prev->p, prev->len); |
DieterGraef | 0:d26c1b55cfca | 1458 | } |
DieterGraef | 0:d26c1b55cfca | 1459 | prev->next = cseg; |
DieterGraef | 0:d26c1b55cfca | 1460 | tcp_oos_insert_segment(cseg, next); |
DieterGraef | 0:d26c1b55cfca | 1461 | } |
DieterGraef | 0:d26c1b55cfca | 1462 | break; |
DieterGraef | 0:d26c1b55cfca | 1463 | } |
DieterGraef | 0:d26c1b55cfca | 1464 | } |
DieterGraef | 0:d26c1b55cfca | 1465 | /* If the "next" segment is the last segment on the |
DieterGraef | 0:d26c1b55cfca | 1466 | ooseq queue, we add the incoming segment to the end |
DieterGraef | 0:d26c1b55cfca | 1467 | of the list. */ |
DieterGraef | 0:d26c1b55cfca | 1468 | if (next->next == NULL && |
DieterGraef | 0:d26c1b55cfca | 1469 | TCP_SEQ_GT(seqno, next->tcphdr->seqno)) { |
DieterGraef | 0:d26c1b55cfca | 1470 | if (TCPH_FLAGS(next->tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 1471 | /* segment "next" already contains all data */ |
DieterGraef | 0:d26c1b55cfca | 1472 | break; |
DieterGraef | 0:d26c1b55cfca | 1473 | } |
DieterGraef | 0:d26c1b55cfca | 1474 | next->next = tcp_seg_copy(&inseg); |
DieterGraef | 0:d26c1b55cfca | 1475 | if (next->next != NULL) { |
DieterGraef | 0:d26c1b55cfca | 1476 | if (TCP_SEQ_GT(next->tcphdr->seqno + next->len, seqno)) { |
DieterGraef | 0:d26c1b55cfca | 1477 | /* We need to trim the last segment. */ |
DieterGraef | 0:d26c1b55cfca | 1478 | next->len = (u16_t)(seqno - next->tcphdr->seqno); |
DieterGraef | 0:d26c1b55cfca | 1479 | pbuf_realloc(next->p, next->len); |
DieterGraef | 0:d26c1b55cfca | 1480 | } |
DieterGraef | 0:d26c1b55cfca | 1481 | /* check if the remote side overruns our receive window */ |
DieterGraef | 0:d26c1b55cfca | 1482 | if ((u32_t)tcplen + seqno > pcb->rcv_nxt + (u32_t)pcb->rcv_wnd) { |
DieterGraef | 0:d26c1b55cfca | 1483 | LWIP_DEBUGF(TCP_INPUT_DEBUG, |
DieterGraef | 0:d26c1b55cfca | 1484 | ("tcp_receive: other end overran receive window" |
DieterGraef | 0:d26c1b55cfca | 1485 | "seqno %"U32_F" len %"U16_F" right edge %"U32_F"\n", |
DieterGraef | 0:d26c1b55cfca | 1486 | seqno, tcplen, pcb->rcv_nxt + pcb->rcv_wnd)); |
DieterGraef | 0:d26c1b55cfca | 1487 | if (TCPH_FLAGS(next->next->tcphdr) & TCP_FIN) { |
DieterGraef | 0:d26c1b55cfca | 1488 | /* Must remove the FIN from the header as we're trimming |
DieterGraef | 0:d26c1b55cfca | 1489 | * that byte of sequence-space from the packet */ |
DieterGraef | 0:d26c1b55cfca | 1490 | TCPH_FLAGS_SET(next->next->tcphdr, TCPH_FLAGS(next->next->tcphdr) &~ TCP_FIN); |
DieterGraef | 0:d26c1b55cfca | 1491 | } |
DieterGraef | 0:d26c1b55cfca | 1492 | /* Adjust length of segment to fit in the window. */ |
DieterGraef | 0:d26c1b55cfca | 1493 | next->next->len = pcb->rcv_nxt + pcb->rcv_wnd - seqno; |
DieterGraef | 0:d26c1b55cfca | 1494 | pbuf_realloc(next->next->p, next->next->len); |
DieterGraef | 0:d26c1b55cfca | 1495 | tcplen = TCP_TCPLEN(next->next); |
DieterGraef | 0:d26c1b55cfca | 1496 | LWIP_ASSERT("tcp_receive: segment not trimmed correctly to rcv_wnd\n", |
DieterGraef | 0:d26c1b55cfca | 1497 | (seqno + tcplen) == (pcb->rcv_nxt + pcb->rcv_wnd)); |
DieterGraef | 0:d26c1b55cfca | 1498 | } |
DieterGraef | 0:d26c1b55cfca | 1499 | } |
DieterGraef | 0:d26c1b55cfca | 1500 | break; |
DieterGraef | 0:d26c1b55cfca | 1501 | } |
DieterGraef | 0:d26c1b55cfca | 1502 | } |
DieterGraef | 0:d26c1b55cfca | 1503 | prev = next; |
DieterGraef | 0:d26c1b55cfca | 1504 | } |
DieterGraef | 0:d26c1b55cfca | 1505 | } |
DieterGraef | 0:d26c1b55cfca | 1506 | #if TCP_OOSEQ_MAX_BYTES || TCP_OOSEQ_MAX_PBUFS |
DieterGraef | 0:d26c1b55cfca | 1507 | /* Check that the data on ooseq doesn't exceed one of the limits |
DieterGraef | 0:d26c1b55cfca | 1508 | and throw away everything above that limit. */ |
DieterGraef | 0:d26c1b55cfca | 1509 | ooseq_blen = 0; |
DieterGraef | 0:d26c1b55cfca | 1510 | ooseq_qlen = 0; |
DieterGraef | 0:d26c1b55cfca | 1511 | prev = NULL; |
DieterGraef | 0:d26c1b55cfca | 1512 | for(next = pcb->ooseq; next != NULL; prev = next, next = next->next) { |
DieterGraef | 0:d26c1b55cfca | 1513 | struct pbuf *p = next->p; |
DieterGraef | 0:d26c1b55cfca | 1514 | ooseq_blen += p->tot_len; |
DieterGraef | 0:d26c1b55cfca | 1515 | ooseq_qlen += pbuf_clen(p); |
DieterGraef | 0:d26c1b55cfca | 1516 | if ((ooseq_blen > TCP_OOSEQ_MAX_BYTES) || |
DieterGraef | 0:d26c1b55cfca | 1517 | (ooseq_qlen > TCP_OOSEQ_MAX_PBUFS)) { |
DieterGraef | 0:d26c1b55cfca | 1518 | /* too much ooseq data, dump this and everything after it */ |
DieterGraef | 0:d26c1b55cfca | 1519 | tcp_segs_free(next); |
DieterGraef | 0:d26c1b55cfca | 1520 | if (prev == NULL) { |
DieterGraef | 0:d26c1b55cfca | 1521 | /* first ooseq segment is too much, dump the whole queue */ |
DieterGraef | 0:d26c1b55cfca | 1522 | pcb->ooseq = NULL; |
DieterGraef | 0:d26c1b55cfca | 1523 | } else { |
DieterGraef | 0:d26c1b55cfca | 1524 | /* just dump 'next' and everything after it */ |
DieterGraef | 0:d26c1b55cfca | 1525 | prev->next = NULL; |
DieterGraef | 0:d26c1b55cfca | 1526 | } |
DieterGraef | 0:d26c1b55cfca | 1527 | break; |
DieterGraef | 0:d26c1b55cfca | 1528 | } |
DieterGraef | 0:d26c1b55cfca | 1529 | } |
DieterGraef | 0:d26c1b55cfca | 1530 | #endif /* TCP_OOSEQ_MAX_BYTES || TCP_OOSEQ_MAX_PBUFS */ |
DieterGraef | 0:d26c1b55cfca | 1531 | #endif /* TCP_QUEUE_OOSEQ */ |
DieterGraef | 0:d26c1b55cfca | 1532 | } |
DieterGraef | 0:d26c1b55cfca | 1533 | } else { |
DieterGraef | 0:d26c1b55cfca | 1534 | /* The incoming segment is not withing the window. */ |
DieterGraef | 0:d26c1b55cfca | 1535 | tcp_send_empty_ack(pcb); |
DieterGraef | 0:d26c1b55cfca | 1536 | } |
DieterGraef | 0:d26c1b55cfca | 1537 | } else { |
DieterGraef | 0:d26c1b55cfca | 1538 | /* Segments with length 0 is taken care of here. Segments that |
DieterGraef | 0:d26c1b55cfca | 1539 | fall out of the window are ACKed. */ |
DieterGraef | 0:d26c1b55cfca | 1540 | /*if (TCP_SEQ_GT(pcb->rcv_nxt, seqno) || |
DieterGraef | 0:d26c1b55cfca | 1541 | TCP_SEQ_GEQ(seqno, pcb->rcv_nxt + pcb->rcv_wnd)) {*/ |
DieterGraef | 0:d26c1b55cfca | 1542 | if(!TCP_SEQ_BETWEEN(seqno, pcb->rcv_nxt, pcb->rcv_nxt + pcb->rcv_wnd-1)){ |
DieterGraef | 0:d26c1b55cfca | 1543 | tcp_ack_now(pcb); |
DieterGraef | 0:d26c1b55cfca | 1544 | } |
DieterGraef | 0:d26c1b55cfca | 1545 | } |
DieterGraef | 0:d26c1b55cfca | 1546 | } |
DieterGraef | 0:d26c1b55cfca | 1547 | |
DieterGraef | 0:d26c1b55cfca | 1548 | /** |
DieterGraef | 0:d26c1b55cfca | 1549 | * Parses the options contained in the incoming segment. |
DieterGraef | 0:d26c1b55cfca | 1550 | * |
DieterGraef | 0:d26c1b55cfca | 1551 | * Called from tcp_listen_input() and tcp_process(). |
DieterGraef | 0:d26c1b55cfca | 1552 | * Currently, only the MSS option is supported! |
DieterGraef | 0:d26c1b55cfca | 1553 | * |
DieterGraef | 0:d26c1b55cfca | 1554 | * @param pcb the tcp_pcb for which a segment arrived |
DieterGraef | 0:d26c1b55cfca | 1555 | */ |
DieterGraef | 0:d26c1b55cfca | 1556 | static void |
DieterGraef | 0:d26c1b55cfca | 1557 | tcp_parseopt(struct tcp_pcb *pcb) |
DieterGraef | 0:d26c1b55cfca | 1558 | { |
DieterGraef | 0:d26c1b55cfca | 1559 | u16_t c, max_c; |
DieterGraef | 0:d26c1b55cfca | 1560 | u16_t mss; |
DieterGraef | 0:d26c1b55cfca | 1561 | u8_t *opts, opt; |
DieterGraef | 0:d26c1b55cfca | 1562 | #if LWIP_TCP_TIMESTAMPS |
DieterGraef | 0:d26c1b55cfca | 1563 | u32_t tsval; |
DieterGraef | 0:d26c1b55cfca | 1564 | #endif |
DieterGraef | 0:d26c1b55cfca | 1565 | |
DieterGraef | 0:d26c1b55cfca | 1566 | opts = (u8_t *)tcphdr + TCP_HLEN; |
DieterGraef | 0:d26c1b55cfca | 1567 | |
DieterGraef | 0:d26c1b55cfca | 1568 | /* Parse the TCP MSS option, if present. */ |
DieterGraef | 0:d26c1b55cfca | 1569 | if(TCPH_HDRLEN(tcphdr) > 0x5) { |
DieterGraef | 0:d26c1b55cfca | 1570 | max_c = (TCPH_HDRLEN(tcphdr) - 5) << 2; |
DieterGraef | 0:d26c1b55cfca | 1571 | for (c = 0; c < max_c; ) { |
DieterGraef | 0:d26c1b55cfca | 1572 | opt = opts[c]; |
DieterGraef | 0:d26c1b55cfca | 1573 | switch (opt) { |
DieterGraef | 0:d26c1b55cfca | 1574 | case 0x00: |
DieterGraef | 0:d26c1b55cfca | 1575 | /* End of options. */ |
DieterGraef | 0:d26c1b55cfca | 1576 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: EOL\n")); |
DieterGraef | 0:d26c1b55cfca | 1577 | return; |
DieterGraef | 0:d26c1b55cfca | 1578 | case 0x01: |
DieterGraef | 0:d26c1b55cfca | 1579 | /* NOP option. */ |
DieterGraef | 0:d26c1b55cfca | 1580 | ++c; |
DieterGraef | 0:d26c1b55cfca | 1581 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: NOP\n")); |
DieterGraef | 0:d26c1b55cfca | 1582 | break; |
DieterGraef | 0:d26c1b55cfca | 1583 | case 0x02: |
DieterGraef | 0:d26c1b55cfca | 1584 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: MSS\n")); |
DieterGraef | 0:d26c1b55cfca | 1585 | if (opts[c + 1] != 0x04 || c + 0x04 > max_c) { |
DieterGraef | 0:d26c1b55cfca | 1586 | /* Bad length */ |
DieterGraef | 0:d26c1b55cfca | 1587 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: bad length\n")); |
DieterGraef | 0:d26c1b55cfca | 1588 | return; |
DieterGraef | 0:d26c1b55cfca | 1589 | } |
DieterGraef | 0:d26c1b55cfca | 1590 | /* An MSS option with the right option length. */ |
DieterGraef | 0:d26c1b55cfca | 1591 | mss = (opts[c + 2] << 8) | opts[c + 3]; |
DieterGraef | 0:d26c1b55cfca | 1592 | /* Limit the mss to the configured TCP_MSS and prevent division by zero */ |
DieterGraef | 0:d26c1b55cfca | 1593 | pcb->mss = ((mss > TCP_MSS) || (mss == 0)) ? TCP_MSS : mss; |
DieterGraef | 0:d26c1b55cfca | 1594 | /* Advance to next option */ |
DieterGraef | 0:d26c1b55cfca | 1595 | c += 0x04; |
DieterGraef | 0:d26c1b55cfca | 1596 | break; |
DieterGraef | 0:d26c1b55cfca | 1597 | #if LWIP_TCP_TIMESTAMPS |
DieterGraef | 0:d26c1b55cfca | 1598 | case 0x08: |
DieterGraef | 0:d26c1b55cfca | 1599 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: TS\n")); |
DieterGraef | 0:d26c1b55cfca | 1600 | if (opts[c + 1] != 0x0A || c + 0x0A > max_c) { |
DieterGraef | 0:d26c1b55cfca | 1601 | /* Bad length */ |
DieterGraef | 0:d26c1b55cfca | 1602 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: bad length\n")); |
DieterGraef | 0:d26c1b55cfca | 1603 | return; |
DieterGraef | 0:d26c1b55cfca | 1604 | } |
DieterGraef | 0:d26c1b55cfca | 1605 | /* TCP timestamp option with valid length */ |
DieterGraef | 0:d26c1b55cfca | 1606 | tsval = (opts[c+2]) | (opts[c+3] << 8) | |
DieterGraef | 0:d26c1b55cfca | 1607 | (opts[c+4] << 16) | (opts[c+5] << 24); |
DieterGraef | 0:d26c1b55cfca | 1608 | if (flags & TCP_SYN) { |
DieterGraef | 0:d26c1b55cfca | 1609 | pcb->ts_recent = ntohl(tsval); |
DieterGraef | 0:d26c1b55cfca | 1610 | pcb->flags |= TF_TIMESTAMP; |
DieterGraef | 0:d26c1b55cfca | 1611 | } else if (TCP_SEQ_BETWEEN(pcb->ts_lastacksent, seqno, seqno+tcplen)) { |
DieterGraef | 0:d26c1b55cfca | 1612 | pcb->ts_recent = ntohl(tsval); |
DieterGraef | 0:d26c1b55cfca | 1613 | } |
DieterGraef | 0:d26c1b55cfca | 1614 | /* Advance to next option */ |
DieterGraef | 0:d26c1b55cfca | 1615 | c += 0x0A; |
DieterGraef | 0:d26c1b55cfca | 1616 | break; |
DieterGraef | 0:d26c1b55cfca | 1617 | #endif |
DieterGraef | 0:d26c1b55cfca | 1618 | default: |
DieterGraef | 0:d26c1b55cfca | 1619 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: other\n")); |
DieterGraef | 0:d26c1b55cfca | 1620 | if (opts[c + 1] == 0) { |
DieterGraef | 0:d26c1b55cfca | 1621 | LWIP_DEBUGF(TCP_INPUT_DEBUG, ("tcp_parseopt: bad length\n")); |
DieterGraef | 0:d26c1b55cfca | 1622 | /* If the length field is zero, the options are malformed |
DieterGraef | 0:d26c1b55cfca | 1623 | and we don't process them further. */ |
DieterGraef | 0:d26c1b55cfca | 1624 | return; |
DieterGraef | 0:d26c1b55cfca | 1625 | } |
DieterGraef | 0:d26c1b55cfca | 1626 | /* All other options have a length field, so that we easily |
DieterGraef | 0:d26c1b55cfca | 1627 | can skip past them. */ |
DieterGraef | 0:d26c1b55cfca | 1628 | c += opts[c + 1]; |
DieterGraef | 0:d26c1b55cfca | 1629 | } |
DieterGraef | 0:d26c1b55cfca | 1630 | } |
DieterGraef | 0:d26c1b55cfca | 1631 | } |
DieterGraef | 0:d26c1b55cfca | 1632 | } |
DieterGraef | 0:d26c1b55cfca | 1633 | |
DieterGraef | 0:d26c1b55cfca | 1634 | #endif /* LWIP_TCP */ |