Wayne Jay
Onenet
Dependents: K64F_eCompass_OneNET_JW
Diff: lwip/core/udp.c
- Revision:
- 0:b2805b6888dc
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/lwip/core/udp.c Mon Jun 20 01:40:20 2016 +0000
@@ -0,0 +1,966 @@
+/**
+ * @file
+ * User Datagram Protocol module
+ *
+ */
+
+/*
+ * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. The name of the author may not be used to endorse or promote products
+ * derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
+ * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
+ * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
+ * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
+ * OF SUCH DAMAGE.
+ *
+ * This file is part of the lwIP TCP/IP stack.
+ *
+ * Author: Adam Dunkels <adam@sics.se>
+ *
+ */
+
+
+/* udp.c
+ *
+ * The code for the User Datagram Protocol UDP & UDPLite (RFC 3828).
+ *
+ */
+
+/* @todo Check the use of '(struct udp_pcb).chksum_len_rx'!
+ */
+
+#include "lwip/opt.h"
+
+#if LWIP_UDP /* don't build if not configured for use in lwipopts.h */
+
+#include "lwip/udp.h"
+#include "lwip/def.h"
+#include "lwip/memp.h"
+#include "lwip/inet_chksum.h"
+#include "lwip/ip_addr.h"
+#include "lwip/netif.h"
+#include "lwip/icmp.h"
+#include "lwip/stats.h"
+#include "lwip/snmp.h"
+#include "arch/perf.h"
+#include "lwip/dhcp.h"
+
+#include <string.h>
+
+/* The list of UDP PCBs */
+/* exported in udp.h (was static) */
+struct udp_pcb *udp_pcbs;
+
+/**
+ * Process an incoming UDP datagram.
+ *
+ * Given an incoming UDP datagram (as a chain of pbufs) this function
+ * finds a corresponding UDP PCB and hands over the pbuf to the pcbs
+ * recv function. If no pcb is found or the datagram is incorrect, the
+ * pbuf is freed.
+ *
+ * @param p pbuf to be demultiplexed to a UDP PCB.
+ * @param inp network interface on which the datagram was received.
+ *
+ */
+void
+udp_input(struct pbuf *p, struct netif *inp)
+{
+ struct udp_hdr *udphdr;
+ struct udp_pcb *pcb, *prev;
+ struct udp_pcb *uncon_pcb;
+ struct ip_hdr *iphdr;
+ u16_t src, dest;
+ u8_t local_match;
+ u8_t broadcast;
+
+ PERF_START;
+
+ UDP_STATS_INC(udp.recv);
+
+ iphdr = (struct ip_hdr *)p->payload;
+
+ /* Check minimum length (IP header + UDP header)
+ * and move payload pointer to UDP header */
+ if (p->tot_len < (IPH_HL(iphdr) * 4 + UDP_HLEN) || pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4))) {
+ /* drop short packets */
+ LWIP_DEBUGF(UDP_DEBUG,
+ ("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len));
+ UDP_STATS_INC(udp.lenerr);
+ UDP_STATS_INC(udp.drop);
+ snmp_inc_udpinerrors();
+ pbuf_free(p);
+ goto end;
+ }
+
+ udphdr = (struct udp_hdr *)p->payload;
+
+ /* is broadcast packet ? */
+ broadcast = ip_addr_isbroadcast(¤t_iphdr_dest, inp);
+
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len));
+
+ /* convert src and dest ports to host byte order */
+ src = ntohs(udphdr->src);
+ dest = ntohs(udphdr->dest);
+
+ udp_debug_print(udphdr);
+
+ /* print the UDP source and destination */
+ LWIP_DEBUGF(UDP_DEBUG,
+ ("udp (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") <-- "
+ "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
+ ip4_addr1_16(&iphdr->dest), ip4_addr2_16(&iphdr->dest),
+ ip4_addr3_16(&iphdr->dest), ip4_addr4_16(&iphdr->dest), ntohs(udphdr->dest),
+ ip4_addr1_16(&iphdr->src), ip4_addr2_16(&iphdr->src),
+ ip4_addr3_16(&iphdr->src), ip4_addr4_16(&iphdr->src), ntohs(udphdr->src)));
+
+#if LWIP_DHCP
+ pcb = NULL;
+ /* when LWIP_DHCP is active, packets to DHCP_CLIENT_PORT may only be processed by
+ the dhcp module, no other UDP pcb may use the local UDP port DHCP_CLIENT_PORT */
+ if (dest == DHCP_CLIENT_PORT) {
+ /* all packets for DHCP_CLIENT_PORT not coming from DHCP_SERVER_PORT are dropped! */
+ if (src == DHCP_SERVER_PORT) {
+ if ((inp->dhcp != NULL) && (inp->dhcp->pcb != NULL)) {
+ /* accept the packe if
+ (- broadcast or directed to us) -> DHCP is link-layer-addressed, local ip is always ANY!
+ - inp->dhcp->pcb->remote == ANY or iphdr->src */
+ if ((ip_addr_isany(&inp->dhcp->pcb->remote_ip) ||
+ ip_addr_cmp(&(inp->dhcp->pcb->remote_ip), ¤t_iphdr_src))) {
+ pcb = inp->dhcp->pcb;
+ }
+ }
+ }
+ } else
+#endif /* LWIP_DHCP */
+ {
+ prev = NULL;
+ local_match = 0;
+ uncon_pcb = NULL;
+ /* Iterate through the UDP pcb list for a matching pcb.
+ * 'Perfect match' pcbs (connected to the remote port & ip address) are
+ * preferred. If no perfect match is found, the first unconnected pcb that
+ * matches the local port and ip address gets the datagram. */
+ for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) {
+ local_match = 0;
+ /* print the PCB local and remote address */
+ LWIP_DEBUGF(UDP_DEBUG,
+ ("pcb (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") --- "
+ "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\n",
+ ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
+ ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip), pcb->local_port,
+ ip4_addr1_16(&pcb->remote_ip), ip4_addr2_16(&pcb->remote_ip),
+ ip4_addr3_16(&pcb->remote_ip), ip4_addr4_16(&pcb->remote_ip), pcb->remote_port));
+
+ /* compare PCB local addr+port to UDP destination addr+port */
+ if ((pcb->local_port == dest) &&
+ ((!broadcast && ip_addr_isany(&pcb->local_ip)) ||
+ ip_addr_cmp(&(pcb->local_ip), ¤t_iphdr_dest) ||
+#if LWIP_IGMP
+ ip_addr_ismulticast(¤t_iphdr_dest) ||
+#endif /* LWIP_IGMP */
+#if IP_SOF_BROADCAST_RECV
+ (broadcast && (pcb->so_options & SOF_BROADCAST)))) {
+#else /* IP_SOF_BROADCAST_RECV */
+ (broadcast))) {
+#endif /* IP_SOF_BROADCAST_RECV */
+ local_match = 1;
+ if ((uncon_pcb == NULL) &&
+ ((pcb->flags & UDP_FLAGS_CONNECTED) == 0)) {
+ /* the first unconnected matching PCB */
+ uncon_pcb = pcb;
+ }
+ }
+ /* compare PCB remote addr+port to UDP source addr+port */
+ if ((local_match != 0) &&
+ (pcb->remote_port == src) &&
+ (ip_addr_isany(&pcb->remote_ip) ||
+ ip_addr_cmp(&(pcb->remote_ip), ¤t_iphdr_src))) {
+ /* the first fully matching PCB */
+ if (prev != NULL) {
+ /* move the pcb to the front of udp_pcbs so that is
+ found faster next time */
+ prev->next = pcb->next;
+ pcb->next = udp_pcbs;
+ udp_pcbs = pcb;
+ } else {
+ UDP_STATS_INC(udp.cachehit);
+ }
+ break;
+ }
+ prev = pcb;
+ }
+ /* no fully matching pcb found? then look for an unconnected pcb */
+ if (pcb == NULL) {
+ pcb = uncon_pcb;
+ }
+ }
+
+ /* Check checksum if this is a match or if it was directed at us. */
+ if (pcb != NULL || ip_addr_cmp(&inp->ip_addr, ¤t_iphdr_dest)) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n"));
+#if LWIP_UDPLITE
+ if (IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) {
+ /* Do the UDP Lite checksum */
+#if CHECKSUM_CHECK_UDP
+ u16_t chklen = ntohs(udphdr->len);
+ if (chklen < sizeof(struct udp_hdr)) {
+ if (chklen == 0) {
+ /* For UDP-Lite, checksum length of 0 means checksum
+ over the complete packet (See RFC 3828 chap. 3.1) */
+ chklen = p->tot_len;
+ } else {
+ /* At least the UDP-Lite header must be covered by the
+ checksum! (Again, see RFC 3828 chap. 3.1) */
+ UDP_STATS_INC(udp.chkerr);
+ UDP_STATS_INC(udp.drop);
+ snmp_inc_udpinerrors();
+ pbuf_free(p);
+ goto end;
+ }
+ }
+ if (inet_chksum_pseudo_partial(p, ¤t_iphdr_src, ¤t_iphdr_dest,
+ IP_PROTO_UDPLITE, p->tot_len, chklen) != 0) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
+ ("udp_input: UDP Lite datagram discarded due to failing checksum\n"));
+ UDP_STATS_INC(udp.chkerr);
+ UDP_STATS_INC(udp.drop);
+ snmp_inc_udpinerrors();
+ pbuf_free(p);
+ goto end;
+ }
+#endif /* CHECKSUM_CHECK_UDP */
+ } else
+#endif /* LWIP_UDPLITE */
+ {
+#if CHECKSUM_CHECK_UDP
+ if (udphdr->chksum != 0) {
+ if (inet_chksum_pseudo(p, ip_current_src_addr(), ip_current_dest_addr(),
+ IP_PROTO_UDP, p->tot_len) != 0) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
+ ("udp_input: UDP datagram discarded due to failing checksum\n"));
+ UDP_STATS_INC(udp.chkerr);
+ UDP_STATS_INC(udp.drop);
+ snmp_inc_udpinerrors();
+ pbuf_free(p);
+ goto end;
+ }
+ }
+#endif /* CHECKSUM_CHECK_UDP */
+ }
+ if(pbuf_header(p, -UDP_HLEN)) {
+ /* Can we cope with this failing? Just assert for now */
+ LWIP_ASSERT("pbuf_header failed\n", 0);
+ UDP_STATS_INC(udp.drop);
+ snmp_inc_udpinerrors();
+ pbuf_free(p);
+ goto end;
+ }
+ if (pcb != NULL) {
+ snmp_inc_udpindatagrams();
+#if SO_REUSE && SO_REUSE_RXTOALL
+ if ((broadcast || ip_addr_ismulticast(¤t_iphdr_dest)) &&
+ ((pcb->so_options & SOF_REUSEADDR) != 0)) {
+ /* pass broadcast- or multicast packets to all multicast pcbs
+ if SOF_REUSEADDR is set on the first match */
+ struct udp_pcb *mpcb;
+ u8_t p_header_changed = 0;
+ for (mpcb = udp_pcbs; mpcb != NULL; mpcb = mpcb->next) {
+ if (mpcb != pcb) {
+ /* compare PCB local addr+port to UDP destination addr+port */
+ if ((mpcb->local_port == dest) &&
+ ((!broadcast && ip_addr_isany(&mpcb->local_ip)) ||
+ ip_addr_cmp(&(mpcb->local_ip), ¤t_iphdr_dest) ||
+#if LWIP_IGMP
+ ip_addr_ismulticast(¤t_iphdr_dest) ||
+#endif /* LWIP_IGMP */
+#if IP_SOF_BROADCAST_RECV
+ (broadcast && (mpcb->so_options & SOF_BROADCAST)))) {
+#else /* IP_SOF_BROADCAST_RECV */
+ (broadcast))) {
+#endif /* IP_SOF_BROADCAST_RECV */
+ /* pass a copy of the packet to all local matches */
+ if (mpcb->recv != NULL) {
+ struct pbuf *q;
+ /* for that, move payload to IP header again */
+ if (p_header_changed == 0) {
+ pbuf_header(p, (s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
+ p_header_changed = 1;
+ }
+ q = pbuf_alloc(PBUF_RAW, p->tot_len, PBUF_RAM);
+ if (q != NULL) {
+ err_t err = pbuf_copy(q, p);
+ if (err == ERR_OK) {
+ /* move payload to UDP data */
+ pbuf_header(q, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
+ mpcb->recv(mpcb->recv_arg, mpcb, q, ip_current_src_addr(), src);
+ }
+ }
+ }
+ }
+ }
+ }
+ if (p_header_changed) {
+ /* and move payload to UDP data again */
+ pbuf_header(p, -(s16_t)((IPH_HL(iphdr) * 4) + UDP_HLEN));
+ }
+ }
+#endif /* SO_REUSE && SO_REUSE_RXTOALL */
+ /* callback */
+ if (pcb->recv != NULL) {
+ /* now the recv function is responsible for freeing p */
+ pcb->recv(pcb->recv_arg, pcb, p, ip_current_src_addr(), src);
+ } else {
+ /* no recv function registered? then we have to free the pbuf! */
+ pbuf_free(p);
+ goto end;
+ }
+ } else {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n"));
+
+#if LWIP_ICMP
+ /* No match was found, send ICMP destination port unreachable unless
+ destination address was broadcast/multicast. */
+ if (!broadcast &&
+ !ip_addr_ismulticast(¤t_iphdr_dest)) {
+ /* move payload pointer back to ip header */
+ pbuf_header(p, (IPH_HL(iphdr) * 4) + UDP_HLEN);
+ LWIP_ASSERT("p->payload == iphdr", (p->payload == iphdr));
+ icmp_dest_unreach(p, ICMP_DUR_PORT);
+ }
+#endif /* LWIP_ICMP */
+ UDP_STATS_INC(udp.proterr);
+ UDP_STATS_INC(udp.drop);
+ snmp_inc_udpnoports();
+ pbuf_free(p);
+ }
+ } else {
+ pbuf_free(p);
+ }
+end:
+ PERF_STOP("udp_input");
+}
+
+/**
+ * Send data using UDP.
+ *
+ * @param pcb UDP PCB used to send the data.
+ * @param p chain of pbuf's to be sent.
+ *
+ * The datagram will be sent to the current remote_ip & remote_port
+ * stored in pcb. If the pcb is not bound to a port, it will
+ * automatically be bound to a random port.
+ *
+ * @return lwIP error code.
+ * - ERR_OK. Successful. No error occured.
+ * - ERR_MEM. Out of memory.
+ * - ERR_RTE. Could not find route to destination address.
+ * - More errors could be returned by lower protocol layers.
+ *
+ * @see udp_disconnect() udp_sendto()
+ */
+err_t
+udp_send(struct udp_pcb *pcb, struct pbuf *p)
+{
+ /* send to the packet using remote ip and port stored in the pcb */
+ return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port);
+}
+
+#if LWIP_CHECKSUM_ON_COPY
+/** Same as udp_send() but with checksum
+ */
+err_t
+udp_send_chksum(struct udp_pcb *pcb, struct pbuf *p,
+ u8_t have_chksum, u16_t chksum)
+{
+ /* send to the packet using remote ip and port stored in the pcb */
+ return udp_sendto_chksum(pcb, p, &pcb->remote_ip, pcb->remote_port,
+ have_chksum, chksum);
+}
+#endif /* LWIP_CHECKSUM_ON_COPY */
+
+/**
+ * Send data to a specified address using UDP.
+ *
+ * @param pcb UDP PCB used to send the data.
+ * @param p chain of pbuf's to be sent.
+ * @param dst_ip Destination IP address.
+ * @param dst_port Destination UDP port.
+ *
+ * dst_ip & dst_port are expected to be in the same byte order as in the pcb.
+ *
+ * If the PCB already has a remote address association, it will
+ * be restored after the data is sent.
+ *
+ * @return lwIP error code (@see udp_send for possible error codes)
+ *
+ * @see udp_disconnect() udp_send()
+ */
+err_t
+udp_sendto(struct udp_pcb *pcb, struct pbuf *p,
+ ip_addr_t *dst_ip, u16_t dst_port)
+{
+#if LWIP_CHECKSUM_ON_COPY
+ return udp_sendto_chksum(pcb, p, dst_ip, dst_port, 0, 0);
+}
+
+/** Same as udp_sendto(), but with checksum */
+err_t
+udp_sendto_chksum(struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *dst_ip,
+ u16_t dst_port, u8_t have_chksum, u16_t chksum)
+{
+#endif /* LWIP_CHECKSUM_ON_COPY */
+ struct netif *netif;
+
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send\n"));
+
+ /* find the outgoing network interface for this packet */
+#if LWIP_IGMP
+ netif = ip_route((ip_addr_ismulticast(dst_ip))?(&(pcb->multicast_ip)):(dst_ip));
+#else
+ netif = ip_route(dst_ip);
+#endif /* LWIP_IGMP */
+
+ /* no outgoing network interface could be found? */
+ if (netif == NULL) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
+ ip4_addr1_16(dst_ip), ip4_addr2_16(dst_ip), ip4_addr3_16(dst_ip), ip4_addr4_16(dst_ip)));
+ UDP_STATS_INC(udp.rterr);
+ return ERR_RTE;
+ }
+#if LWIP_CHECKSUM_ON_COPY
+ return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, have_chksum, chksum);
+#else /* LWIP_CHECKSUM_ON_COPY */
+ return udp_sendto_if(pcb, p, dst_ip, dst_port, netif);
+#endif /* LWIP_CHECKSUM_ON_COPY */
+}
+
+/**
+ * Send data to a specified address using UDP.
+ * The netif used for sending can be specified.
+ *
+ * This function exists mainly for DHCP, to be able to send UDP packets
+ * on a netif that is still down.
+ *
+ * @param pcb UDP PCB used to send the data.
+ * @param p chain of pbuf's to be sent.
+ * @param dst_ip Destination IP address.
+ * @param dst_port Destination UDP port.
+ * @param netif the netif used for sending.
+ *
+ * dst_ip & dst_port are expected to be in the same byte order as in the pcb.
+ *
+ * @return lwIP error code (@see udp_send for possible error codes)
+ *
+ * @see udp_disconnect() udp_send()
+ */
+err_t
+udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p,
+ ip_addr_t *dst_ip, u16_t dst_port, struct netif *netif)
+{
+#if LWIP_CHECKSUM_ON_COPY
+ return udp_sendto_if_chksum(pcb, p, dst_ip, dst_port, netif, 0, 0);
+}
+
+/** Same as udp_sendto_if(), but with checksum */
+err_t
+udp_sendto_if_chksum(struct udp_pcb *pcb, struct pbuf *p, ip_addr_t *dst_ip,
+ u16_t dst_port, struct netif *netif, u8_t have_chksum,
+ u16_t chksum)
+{
+#endif /* LWIP_CHECKSUM_ON_COPY */
+ struct udp_hdr *udphdr;
+ ip_addr_t *src_ip;
+ err_t err;
+ struct pbuf *q; /* q will be sent down the stack */
+
+#if IP_SOF_BROADCAST
+ /* broadcast filter? */
+ if ( ((pcb->so_options & SOF_BROADCAST) == 0) && ip_addr_isbroadcast(dst_ip, netif) ) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
+ ("udp_sendto_if: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb));
+ return ERR_VAL;
+ }
+#endif /* IP_SOF_BROADCAST */
+
+ /* if the PCB is not yet bound to a port, bind it here */
+ if (pcb->local_port == 0) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send: not yet bound to a port, binding now\n"));
+ err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
+ if (err != ERR_OK) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: forced port bind failed\n"));
+ return err;
+ }
+ }
+
+ /* not enough space to add an UDP header to first pbuf in given p chain? */
+ if (pbuf_header(p, UDP_HLEN)) {
+ /* allocate header in a separate new pbuf */
+ q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM);
+ /* new header pbuf could not be allocated? */
+ if (q == NULL) {
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: could not allocate header\n"));
+ return ERR_MEM;
+ }
+ if (p->tot_len != 0) {
+ /* chain header q in front of given pbuf p (only if p contains data) */
+ pbuf_chain(q, p);
+ }
+ /* first pbuf q points to header pbuf */
+ LWIP_DEBUGF(UDP_DEBUG,
+ ("udp_send: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p));
+ } else {
+ /* adding space for header within p succeeded */
+ /* first pbuf q equals given pbuf */
+ q = p;
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: added header in given pbuf %p\n", (void *)p));
+ }
+ LWIP_ASSERT("check that first pbuf can hold struct udp_hdr",
+ (q->len >= sizeof(struct udp_hdr)));
+ /* q now represents the packet to be sent */
+ udphdr = (struct udp_hdr *)q->payload;
+ udphdr->src = htons(pcb->local_port);
+ udphdr->dest = htons(dst_port);
+ /* in UDP, 0 checksum means 'no checksum' */
+ udphdr->chksum = 0x0000;
+
+ /* Multicast Loop? */
+#if LWIP_IGMP
+ if (ip_addr_ismulticast(dst_ip) && ((pcb->flags & UDP_FLAGS_MULTICAST_LOOP) != 0)) {
+ q->flags |= PBUF_FLAG_MCASTLOOP;
+ }
+#endif /* LWIP_IGMP */
+
+
+ /* PCB local address is IP_ANY_ADDR? */
+ if (ip_addr_isany(&pcb->local_ip)) {
+ /* use outgoing network interface IP address as source address */
+ src_ip = &(netif->ip_addr);
+ } else {
+ /* check if UDP PCB local IP address is correct
+ * this could be an old address if netif->ip_addr has changed */
+ if (!ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) {
+ /* local_ip doesn't match, drop the packet */
+ if (q != p) {
+ /* free the header pbuf */
+ pbuf_free(q);
+ q = NULL;
+ /* p is still referenced by the caller, and will live on */
+ }
+ return ERR_VAL;
+ }
+ /* use UDP PCB local IP address as source address */
+ src_ip = &(pcb->local_ip);
+ }
+
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %"U16_F"\n", q->tot_len));
+
+#if LWIP_UDPLITE
+ /* UDP Lite protocol? */
+ if (pcb->flags & UDP_FLAGS_UDPLITE) {
+ u16_t chklen, chklen_hdr;
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %"U16_F"\n", q->tot_len));
+ /* set UDP message length in UDP header */
+ chklen_hdr = chklen = pcb->chksum_len_tx;
+ if ((chklen < sizeof(struct udp_hdr)) || (chklen > q->tot_len)) {
+ if (chklen != 0) {
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE pcb->chksum_len is illegal: %"U16_F"\n", chklen));
+ }
+ /* For UDP-Lite, checksum length of 0 means checksum
+ over the complete packet. (See RFC 3828 chap. 3.1)
+ At least the UDP-Lite header must be covered by the
+ checksum, therefore, if chksum_len has an illegal
+ value, we generate the checksum over the complete
+ packet to be safe. */
+ chklen_hdr = 0;
+ chklen = q->tot_len;
+ }
+ udphdr->len = htons(chklen_hdr);
+ /* calculate checksum */
+#if CHECKSUM_GEN_UDP
+ udphdr->chksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip,
+ IP_PROTO_UDPLITE, q->tot_len,
+#if !LWIP_CHECKSUM_ON_COPY
+ chklen);
+#else /* !LWIP_CHECKSUM_ON_COPY */
+ (have_chksum ? UDP_HLEN : chklen));
+ if (have_chksum) {
+ u32_t acc;
+ acc = udphdr->chksum + (u16_t)~(chksum);
+ udphdr->chksum = FOLD_U32T(acc);
+ }
+#endif /* !LWIP_CHECKSUM_ON_COPY */
+
+ /* chksum zero must become 0xffff, as zero means 'no checksum' */
+ if (udphdr->chksum == 0x0000) {
+ udphdr->chksum = 0xffff;
+ }
+#endif /* CHECKSUM_GEN_UDP */
+ /* output to IP */
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDPLITE,)\n"));
+#if LWIP_NETIF_HWADDRHINT
+ netif->addr_hint = &(pcb->addr_hint);
+#endif /* LWIP_NETIF_HWADDRHINT*/
+ err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDPLITE, netif);
+#if LWIP_NETIF_HWADDRHINT
+ netif->addr_hint = NULL;
+#endif /* LWIP_NETIF_HWADDRHINT*/
+ } else
+#endif /* LWIP_UDPLITE */
+ { /* UDP */
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len));
+ udphdr->len = htons(q->tot_len);
+ /* calculate checksum */
+#if CHECKSUM_GEN_UDP
+ if ((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) {
+ u16_t udpchksum;
+#if LWIP_CHECKSUM_ON_COPY
+ if (have_chksum) {
+ u32_t acc;
+ udpchksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip, IP_PROTO_UDP,
+ q->tot_len, UDP_HLEN);
+ acc = udpchksum + (u16_t)~(chksum);
+ udpchksum = FOLD_U32T(acc);
+ } else
+#endif /* LWIP_CHECKSUM_ON_COPY */
+ {
+ udpchksum = inet_chksum_pseudo(q, src_ip, dst_ip, IP_PROTO_UDP, q->tot_len);
+ }
+
+ /* chksum zero must become 0xffff, as zero means 'no checksum' */
+ if (udpchksum == 0x0000) {
+ udpchksum = 0xffff;
+ }
+ udphdr->chksum = udpchksum;
+ }
+#endif /* CHECKSUM_GEN_UDP */
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum));
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDP,)\n"));
+ /* output to IP */
+#if LWIP_NETIF_HWADDRHINT
+ netif->addr_hint = &(pcb->addr_hint);
+#endif /* LWIP_NETIF_HWADDRHINT*/
+ err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDP, netif);
+#if LWIP_NETIF_HWADDRHINT
+ netif->addr_hint = NULL;
+#endif /* LWIP_NETIF_HWADDRHINT*/
+ }
+ /* TODO: must this be increased even if error occured? */
+ snmp_inc_udpoutdatagrams();
+
+ /* did we chain a separate header pbuf earlier? */
+ if (q != p) {
+ /* free the header pbuf */
+ pbuf_free(q);
+ q = NULL;
+ /* p is still referenced by the caller, and will live on */
+ }
+
+ UDP_STATS_INC(udp.xmit);
+ return err;
+}
+
+/**
+ * Bind an UDP PCB.
+ *
+ * @param pcb UDP PCB to be bound with a local address ipaddr and port.
+ * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to
+ * bind to all local interfaces.
+ * @param port local UDP port to bind with. Use 0 to automatically bind
+ * to a random port between UDP_LOCAL_PORT_RANGE_START and
+ * UDP_LOCAL_PORT_RANGE_END.
+ *
+ * ipaddr & port are expected to be in the same byte order as in the pcb.
+ *
+ * @return lwIP error code.
+ * - ERR_OK. Successful. No error occured.
+ * - ERR_USE. The specified ipaddr and port are already bound to by
+ * another UDP PCB.
+ *
+ * @see udp_disconnect()
+ */
+err_t
+udp_bind(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port)
+{
+ struct udp_pcb *ipcb;
+ u8_t rebind;
+
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_bind(ipaddr = "));
+ ip_addr_debug_print(UDP_DEBUG, ipaddr);
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, (", port = %"U16_F")\n", port));
+
+ rebind = 0;
+ /* Check for double bind and rebind of the same pcb */
+ for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
+ /* is this UDP PCB already on active list? */
+ if (pcb == ipcb) {
+ /* pcb may occur at most once in active list */
+ LWIP_ASSERT("rebind == 0", rebind == 0);
+ /* pcb already in list, just rebind */
+ rebind = 1;
+ }
+
+ /* By default, we don't allow to bind to a port that any other udp
+ PCB is alread bound to, unless *all* PCBs with that port have tha
+ REUSEADDR flag set. */
+#if SO_REUSE
+ else if (((pcb->so_options & SOF_REUSEADDR) == 0) &&
+ ((ipcb->so_options & SOF_REUSEADDR) == 0)) {
+#else /* SO_REUSE */
+ /* port matches that of PCB in list and REUSEADDR not set -> reject */
+ else {
+#endif /* SO_REUSE */
+ if ((ipcb->local_port == port) &&
+ /* IP address matches, or one is IP_ADDR_ANY? */
+ (ip_addr_isany(&(ipcb->local_ip)) ||
+ ip_addr_isany(ipaddr) ||
+ ip_addr_cmp(&(ipcb->local_ip), ipaddr))) {
+ /* other PCB already binds to this local IP and port */
+ LWIP_DEBUGF(UDP_DEBUG,
+ ("udp_bind: local port %"U16_F" already bound by another pcb\n", port));
+ return ERR_USE;
+ }
+ }
+ }
+
+ ip_addr_set(&pcb->local_ip, ipaddr);
+
+ /* no port specified? */
+ if (port == 0) {
+#ifndef UDP_LOCAL_PORT_RANGE_START
+/* From http://www.iana.org/assignments/port-numbers:
+ "The Dynamic and/or Private Ports are those from 49152 through 65535" */
+#define UDP_LOCAL_PORT_RANGE_START 0xc000
+#define UDP_LOCAL_PORT_RANGE_END 0xffff
+#endif
+ port = UDP_LOCAL_PORT_RANGE_START;
+ ipcb = udp_pcbs;
+ while ((ipcb != NULL) && (port != UDP_LOCAL_PORT_RANGE_END)) {
+ if (ipcb->local_port == port) {
+ /* port is already used by another udp_pcb */
+ port++;
+ /* restart scanning all udp pcbs */
+ ipcb = udp_pcbs;
+ } else {
+ /* go on with next udp pcb */
+ ipcb = ipcb->next;
+ }
+ }
+ if (ipcb != NULL) {
+ /* no more ports available in local range */
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n"));
+ return ERR_USE;
+ }
+ }
+ pcb->local_port = port;
+ snmp_insert_udpidx_tree(pcb);
+ /* pcb not active yet? */
+ if (rebind == 0) {
+ /* place the PCB on the active list if not already there */
+ pcb->next = udp_pcbs;
+ udp_pcbs = pcb;
+ }
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+ ("udp_bind: bound to %"U16_F".%"U16_F".%"U16_F".%"U16_F", port %"U16_F"\n",
+ ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
+ ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip),
+ pcb->local_port));
+ return ERR_OK;
+}
+/**
+ * Connect an UDP PCB.
+ *
+ * This will associate the UDP PCB with the remote address.
+ *
+ * @param pcb UDP PCB to be connected with remote address ipaddr and port.
+ * @param ipaddr remote IP address to connect with.
+ * @param port remote UDP port to connect with.
+ *
+ * @return lwIP error code
+ *
+ * ipaddr & port are expected to be in the same byte order as in the pcb.
+ *
+ * The udp pcb is bound to a random local port if not already bound.
+ *
+ * @see udp_disconnect()
+ */
+err_t
+udp_connect(struct udp_pcb *pcb, ip_addr_t *ipaddr, u16_t port)
+{
+ struct udp_pcb *ipcb;
+
+ if (pcb->local_port == 0) {
+ err_t err = udp_bind(pcb, &pcb->local_ip, pcb->local_port);
+ if (err != ERR_OK) {
+ return err;
+ }
+ }
+
+ ip_addr_set(&pcb->remote_ip, ipaddr);
+ pcb->remote_port = port;
+ pcb->flags |= UDP_FLAGS_CONNECTED;
+/** TODO: this functionality belongs in upper layers */
+#ifdef LWIP_UDP_TODO
+ /* Nail down local IP for netconn_addr()/getsockname() */
+ if (ip_addr_isany(&pcb->local_ip) && !ip_addr_isany(&pcb->remote_ip)) {
+ struct netif *netif;
+
+ if ((netif = ip_route(&(pcb->remote_ip))) == NULL) {
+ LWIP_DEBUGF(UDP_DEBUG, ("udp_connect: No route to 0x%lx\n", pcb->remote_ip.addr));
+ UDP_STATS_INC(udp.rterr);
+ return ERR_RTE;
+ }
+ /** TODO: this will bind the udp pcb locally, to the interface which
+ is used to route output packets to the remote address. However, we
+ might want to accept incoming packets on any interface! */
+ pcb->local_ip = netif->ip_addr;
+ } else if (ip_addr_isany(&pcb->remote_ip)) {
+ pcb->local_ip.addr = 0;
+ }
+#endif
+ LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE,
+ ("udp_connect: connected to %"U16_F".%"U16_F".%"U16_F".%"U16_F",port %"U16_F"\n",
+ ip4_addr1_16(&pcb->local_ip), ip4_addr2_16(&pcb->local_ip),
+ ip4_addr3_16(&pcb->local_ip), ip4_addr4_16(&pcb->local_ip),
+ pcb->local_port));
+
+ /* Insert UDP PCB into the list of active UDP PCBs. */
+ for (ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) {
+ if (pcb == ipcb) {
+ /* already on the list, just return */
+ return ERR_OK;
+ }
+ }
+ /* PCB not yet on the list, add PCB now */
+ pcb->next = udp_pcbs;
+ udp_pcbs = pcb;
+ return ERR_OK;
+}
+
+/**
+ * Disconnect a UDP PCB
+ *
+ * @param pcb the udp pcb to disconnect.
+ */
+void
+udp_disconnect(struct udp_pcb *pcb)
+{
+ /* reset remote address association */
+ ip_addr_set_any(&pcb->remote_ip);
+ pcb->remote_port = 0;
+ /* mark PCB as unconnected */
+ pcb->flags &= ~UDP_FLAGS_CONNECTED;
+}
+
+/**
+ * Set a receive callback for a UDP PCB
+ *
+ * This callback will be called when receiving a datagram for the pcb.
+ *
+ * @param pcb the pcb for wich to set the recv callback
+ * @param recv function pointer of the callback function
+ * @param recv_arg additional argument to pass to the callback function
+ */
+void
+udp_recv(struct udp_pcb *pcb, udp_recv_fn recv, void *recv_arg)
+{
+ /* remember recv() callback and user data */
+ pcb->recv = recv;
+ pcb->recv_arg = recv_arg;
+}
+
+/**
+ * Remove an UDP PCB.
+ *
+ * @param pcb UDP PCB to be removed. The PCB is removed from the list of
+ * UDP PCB's and the data structure is freed from memory.
+ *
+ * @see udp_new()
+ */
+void
+udp_remove(struct udp_pcb *pcb)
+{
+ struct udp_pcb *pcb2;
+
+ snmp_delete_udpidx_tree(pcb);
+ /* pcb to be removed is first in list? */
+ if (udp_pcbs == pcb) {
+ /* make list start at 2nd pcb */
+ udp_pcbs = udp_pcbs->next;
+ /* pcb not 1st in list */
+ } else {
+ for (pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) {
+ /* find pcb in udp_pcbs list */
+ if (pcb2->next != NULL && pcb2->next == pcb) {
+ /* remove pcb from list */
+ pcb2->next = pcb->next;
+ }
+ }
+ }
+ memp_free(MEMP_UDP_PCB, pcb);
+}
+
+/**
+ * Create a UDP PCB.
+ *
+ * @return The UDP PCB which was created. NULL if the PCB data structure
+ * could not be allocated.
+ *
+ * @see udp_remove()
+ */
+struct udp_pcb *
+udp_new(void)
+{
+ struct udp_pcb *pcb;
+ pcb = (struct udp_pcb *)memp_malloc(MEMP_UDP_PCB);
+ /* could allocate UDP PCB? */
+ if (pcb != NULL) {
+ /* UDP Lite: by initializing to all zeroes, chksum_len is set to 0
+ * which means checksum is generated over the whole datagram per default
+ * (recommended as default by RFC 3828). */
+ /* initialize PCB to all zeroes */
+ memset(pcb, 0, sizeof(struct udp_pcb));
+ pcb->ttl = UDP_TTL;
+ }
+ return pcb;
+}
+
+#if UDP_DEBUG
+/**
+ * Print UDP header information for debug purposes.
+ *
+ * @param udphdr pointer to the udp header in memory.
+ */
+void
+udp_debug_print(struct udp_hdr *udphdr)
+{
+ LWIP_DEBUGF(UDP_DEBUG, ("UDP header:\n"));
+ LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | %5"U16_F" | (src port, dest port)\n",
+ ntohs(udphdr->src), ntohs(udphdr->dest)));
+ LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
+ LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | 0x%04"X16_F" | (len, chksum)\n",
+ ntohs(udphdr->len), ntohs(udphdr->chksum)));
+ LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n"));
+}
+#endif /* UDP_DEBUG */
+
+#endif /* LWIP_UDP */