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uitility/uip.c@0:5350a66d5279, 2014-09-15 (annotated)

Committer:: hudakz
Date:: Mon Sep 15 11:12:30 2014 +0000
Revision:: 0:5350a66d5279

rev. 00

Who changed what in which revision?

User	Revision	Line number	New contents of line
hudakz	0:5350a66d5279	1	#define DEBUG_PRINTF(...) /printf(__VA_ARGS__)/
hudakz	0:5350a66d5279	2
hudakz	0:5350a66d5279	3	/**
hudakz	0:5350a66d5279	4	* \defgroup uip The uIP TCP/IP stack
hudakz	0:5350a66d5279	5	* @{
hudakz	0:5350a66d5279	6	*
hudakz	0:5350a66d5279	7	* uIP is an implementation of the TCP/IP protocol stack intended for
hudakz	0:5350a66d5279	8	* small 8-bit and 16-bit microcontrollers.
hudakz	0:5350a66d5279	9	*
hudakz	0:5350a66d5279	10	* uIP provides the necessary protocols for Internet communication,
hudakz	0:5350a66d5279	11	* with a very small code footprint and RAM requirements - the uIP
hudakz	0:5350a66d5279	12	* code size is on the order of a few kilobytes and RAM usage is on
hudakz	0:5350a66d5279	13	* the order of a few hundred bytes.
hudakz	0:5350a66d5279	14	*/
hudakz	0:5350a66d5279	15
hudakz	0:5350a66d5279	16	/**
hudakz	0:5350a66d5279	17	* \file
hudakz	0:5350a66d5279	18	* The uIP TCP/IP stack code.
hudakz	0:5350a66d5279	19	* \author Adam Dunkels <adam@dunkels.com>
hudakz	0:5350a66d5279	20	*/
hudakz	0:5350a66d5279	21	/*
hudakz	0:5350a66d5279	22	* Copyright (c) 2001-2003, Adam Dunkels.
hudakz	0:5350a66d5279	23	* All rights reserved.
hudakz	0:5350a66d5279	24	*
hudakz	0:5350a66d5279	25	* Redistribution and use in source and binary forms, with or without
hudakz	0:5350a66d5279	26	* modification, are permitted provided that the following conditions
hudakz	0:5350a66d5279	27	* are met:
hudakz	0:5350a66d5279	28	* 1. Redistributions of source code must retain the above copyright
hudakz	0:5350a66d5279	29	* notice, this list of conditions and the following disclaimer.
hudakz	0:5350a66d5279	30	* 2. Redistributions in binary form must reproduce the above copyright
hudakz	0:5350a66d5279	31	* notice, this list of conditions and the following disclaimer in the
hudakz	0:5350a66d5279	32	* documentation and/or other materials provided with the distribution.
hudakz	0:5350a66d5279	33	* 3. The name of the author may not be used to endorse or promote
hudakz	0:5350a66d5279	34	* products derived from this software without specific prior
hudakz	0:5350a66d5279	35	* written permission.
hudakz	0:5350a66d5279	36	*
hudakz	0:5350a66d5279	37	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
hudakz	0:5350a66d5279	38	* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
hudakz	0:5350a66d5279	39	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
hudakz	0:5350a66d5279	40	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
hudakz	0:5350a66d5279	41	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
hudakz	0:5350a66d5279	42	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
hudakz	0:5350a66d5279	43	* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hudakz	0:5350a66d5279	44	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
hudakz	0:5350a66d5279	45	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
hudakz	0:5350a66d5279	46	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
hudakz	0:5350a66d5279	47	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
hudakz	0:5350a66d5279	48	*
hudakz	0:5350a66d5279	49	* This file is part of the uIP TCP/IP stack.
hudakz	0:5350a66d5279	50	*
hudakz	0:5350a66d5279	51	* $Id: uip.c,v 1.65 2006/06/11 21:46:39 adam Exp $
hudakz	0:5350a66d5279	52	*
hudakz	0:5350a66d5279	53	*/
hudakz	0:5350a66d5279	54	/*
hudakz	0:5350a66d5279	55	* uIP is a small implementation of the IP, UDP and TCP protocols (as
hudakz	0:5350a66d5279	56	* well as some basic ICMP stuff). The implementation couples the IP,
hudakz	0:5350a66d5279	57	* UDP, TCP and the application layers very tightly. To keep the size
hudakz	0:5350a66d5279	58	* of the compiled code down, this code frequently uses the goto
hudakz	0:5350a66d5279	59	* statement. While it would be possible to break the uip_process()
hudakz	0:5350a66d5279	60	* function into many smaller functions, this would increase the code
hudakz	0:5350a66d5279	61	* size because of the overhead of parameter passing and the fact that
hudakz	0:5350a66d5279	62	* the optimier would not be as efficient.
hudakz	0:5350a66d5279	63	*
hudakz	0:5350a66d5279	64	* The principle is that we have a small buffer, called the uip_buf,
hudakz	0:5350a66d5279	65	* in which the device driver puts an incoming packet. The TCP/IP
hudakz	0:5350a66d5279	66	* stack parses the headers in the packet, and calls the
hudakz	0:5350a66d5279	67	* application. If the remote host has sent data to the application,
hudakz	0:5350a66d5279	68	* this data is present in the uip_buf and the application read the
hudakz	0:5350a66d5279	69	* data from there. It is up to the application to put this data into
hudakz	0:5350a66d5279	70	* a byte stream if needed. The application will not be fed with data
hudakz	0:5350a66d5279	71	* that is out of sequence.
hudakz	0:5350a66d5279	72	*
hudakz	0:5350a66d5279	73	* If the application whishes to send data to the peer, it should put
hudakz	0:5350a66d5279	74	* its data into the uip_buf. The uip_appdata pointer points to the
hudakz	0:5350a66d5279	75	* first available byte. The TCP/IP stack will calculate the
hudakz	0:5350a66d5279	76	* checksums, and fill in the necessary header fields and finally send
hudakz	0:5350a66d5279	77	* the packet back to the peer.
hudakz	0:5350a66d5279	78	*/
hudakz	0:5350a66d5279	79	#include "uip.h"
hudakz	0:5350a66d5279	80	#include "uipopt.h"
hudakz	0:5350a66d5279	81	#include "uip_arch.h"
hudakz	0:5350a66d5279	82
hudakz	0:5350a66d5279	83	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	84	#include "uip-neighbor.h"
hudakz	0:5350a66d5279	85	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	86
hudakz	0:5350a66d5279	87	#include <string.h>
hudakz	0:5350a66d5279	88
hudakz	0:5350a66d5279	89	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	90
hudakz	0:5350a66d5279	91	/* Variable definitions. */
hudakz	0:5350a66d5279	92	/* The IP address of this host. If it is defined to be fixed (by
hudakz	0:5350a66d5279	93	setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
hudakz	0:5350a66d5279	94	here. Otherwise, the address */
hudakz	0:5350a66d5279	95	#if UIP_FIXEDADDR > 0
hudakz	0:5350a66d5279	96	const uip_ipaddr_t uip_hostaddr = { HTONS((UIP_IPADDR0 << 8) \| UIP_IPADDR1), HTONS
hudakz	0:5350a66d5279	97	((UIP_IPADDR2 << 8) \| UIP_IPADDR3) };
hudakz	0:5350a66d5279	98	const uip_ipaddr_t uip_draddr =
hudakz	0:5350a66d5279	99	{
hudakz	0:5350a66d5279	100	HTONS((UIP_DRIPADDR0 << 8) \| UIP_DRIPADDR1),
hudakz	0:5350a66d5279	101	HTONS((UIP_DRIPADDR2 << 8) \| UIP_DRIPADDR3)
hudakz	0:5350a66d5279	102	};
hudakz	0:5350a66d5279	103	const uip_ipaddr_t uip_netmask =
hudakz	0:5350a66d5279	104	{
hudakz	0:5350a66d5279	105	HTONS((UIP_NETMASK0 << 8) \| UIP_NETMASK1),
hudakz	0:5350a66d5279	106	HTONS((UIP_NETMASK2 << 8) \| UIP_NETMASK3)
hudakz	0:5350a66d5279	107	};
hudakz	0:5350a66d5279	108	#else
hudakz	0:5350a66d5279	109	uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
hudakz	0:5350a66d5279	110	#endif /* UIP_FIXEDADDR */
hudakz	0:5350a66d5279	111
hudakz	0:5350a66d5279	112	static const uip_ipaddr_t all_ones_addr =
hudakz	0:5350a66d5279	113	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	114	{ 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff };
hudakz	0:5350a66d5279	115	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	116	{
hudakz	0:5350a66d5279	117	0xffff, 0xffff
hudakz	0:5350a66d5279	118	};
hudakz	0:5350a66d5279	119	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	120	static const uip_ipaddr_t all_zeroes_addr =
hudakz	0:5350a66d5279	121	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	122	{ 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 };
hudakz	0:5350a66d5279	123	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	124	{
hudakz	0:5350a66d5279	125	0x0000, 0x0000
hudakz	0:5350a66d5279	126	};
hudakz	0:5350a66d5279	127	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	128
hudakz	0:5350a66d5279	129	#if UIP_FIXEDETHADDR
hudakz	0:5350a66d5279	130	const struct uip_eth_addr uip_ethaddr =
hudakz	0:5350a66d5279	131	{
hudakz	0:5350a66d5279	132	{ UIP_ETHADDR0, UIP_ETHADDR1, UIP_ETHADDR2, UIP_ETHADDR3, UIP_ETHADDR4, UIP_ETHADDR5 }
hudakz	0:5350a66d5279	133	};
hudakz	0:5350a66d5279	134	#else
hudakz	0:5350a66d5279	135	struct uip_eth_addr uip_ethaddr = { { 0, 0, 0, 0, 0, 0 } };
hudakz	0:5350a66d5279	136	#endif
hudakz	0:5350a66d5279	137	#ifndef UIP_CONF_EXTERNAL_BUFFER
hudakz	0:5350a66d5279	138	u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains
hudakz	0:5350a66d5279	139	incoming packets. */
hudakz	0:5350a66d5279	140	#endif /* UIP_CONF_EXTERNAL_BUFFER */
hudakz	0:5350a66d5279	141
hudakz	0:5350a66d5279	142	void* uip_appdata; /* The uip_appdata pointer points to
hudakz	0:5350a66d5279	143	application data. */
hudakz	0:5350a66d5279	144	void* uip_sappdata; /* The uip_appdata pointer points to
hudakz	0:5350a66d5279	145	the application data which is to
hudakz	0:5350a66d5279	146	be sent. */
hudakz	0:5350a66d5279	147	#if UIP_URGDATA > 0
hudakz	0:5350a66d5279	148	void* uip_urgdata; /* The uip_urgdata pointer points to
hudakz	0:5350a66d5279	149	urgent data (out-of-band data), if
hudakz	0:5350a66d5279	150	present. */
hudakz	0:5350a66d5279	151	u16_t uip_urglen, uip_surglen;
hudakz	0:5350a66d5279	152	#endif /* UIP_URGDATA > 0 */
hudakz	0:5350a66d5279	153
hudakz	0:5350a66d5279	154	u16_t uip_len, uip_slen;
hudakz	0:5350a66d5279	155
hudakz	0:5350a66d5279	156	/* The uip_len is either 8 or 16 bits,
hudakz	0:5350a66d5279	157	depending on the maximum packet
hudakz	0:5350a66d5279	158	size. */
hudakz	0:5350a66d5279	159	u8_t uip_flags; /* The uip_flags variable is used for
hudakz	0:5350a66d5279	160	communication between the TCP/IP stack
hudakz	0:5350a66d5279	161	and the application program. */
hudakz	0:5350a66d5279	162	struct uip_conn* uip_conn; /* uip_conn always points to the current
hudakz	0:5350a66d5279	163	connection. */
hudakz	0:5350a66d5279	164
hudakz	0:5350a66d5279	165	struct uip_conn uip_conns[UIP_CONNS];
hudakz	0:5350a66d5279	166
hudakz	0:5350a66d5279	167	/* The uip_conns array holds all TCP
hudakz	0:5350a66d5279	168	connections. */
hudakz	0:5350a66d5279	169	u16_t uip_listenports[UIP_LISTENPORTS];
hudakz	0:5350a66d5279	170
hudakz	0:5350a66d5279	171	/* The uip_listenports list all currently
hudakz	0:5350a66d5279	172	listning ports. */
hudakz	0:5350a66d5279	173	#if UIP_UDP
hudakz	0:5350a66d5279	174	struct uip_udp_conn* uip_udp_conn;
hudakz	0:5350a66d5279	175	struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
hudakz	0:5350a66d5279	176	#endif /* UIP_UDP */
hudakz	0:5350a66d5279	177
hudakz	0:5350a66d5279	178	static u16_t ipid; /* Ths ipid variable is an increasing
hudakz	0:5350a66d5279	179	number that is used for the IP ID
hudakz	0:5350a66d5279	180	field. */
hudakz	0:5350a66d5279	181
hudakz	0:5350a66d5279	182	/**
hudakz	0:5350a66d5279	183	* @brief
hudakz	0:5350a66d5279	184	* @note
hudakz	0:5350a66d5279	185	* @param
hudakz	0:5350a66d5279	186	* @retval
hudakz	0:5350a66d5279	187	*/
hudakz	0:5350a66d5279	188	void uip_setipid(u16_t id) {
hudakz	0:5350a66d5279	189	ipid = id;
hudakz	0:5350a66d5279	190	}
hudakz	0:5350a66d5279	191
hudakz	0:5350a66d5279	192	static u8_t iss[4]; /* The iss variable is used for the TCP
hudakz	0:5350a66d5279	193	initial sequence number. */
hudakz	0:5350a66d5279	194
hudakz	0:5350a66d5279	195	#if UIP_ACTIVE_OPEN
hudakz	0:5350a66d5279	196	static u16_t lastport; /* Keeps track of the last port used for
hudakz	0:5350a66d5279	197	a new connection. */
hudakz	0:5350a66d5279	198	#endif /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	199
hudakz	0:5350a66d5279	200	/* Temporary variables. */
hudakz	0:5350a66d5279	201
hudakz	0:5350a66d5279	202	u8_t uip_acc32[4];
hudakz	0:5350a66d5279	203	static u8_t c, opt;
hudakz	0:5350a66d5279	204	static u16_t tmp16;
hudakz	0:5350a66d5279	205
hudakz	0:5350a66d5279	206	/* Structures and definitions. */
hudakz	0:5350a66d5279	207
hudakz	0:5350a66d5279	208	#define TCP_FIN 0x01
hudakz	0:5350a66d5279	209	#define TCP_SYN 0x02
hudakz	0:5350a66d5279	210	#define TCP_RST 0x04
hudakz	0:5350a66d5279	211	#define TCP_PSH 0x08
hudakz	0:5350a66d5279	212	#define TCP_ACK 0x10
hudakz	0:5350a66d5279	213	#define TCP_URG 0x20
hudakz	0:5350a66d5279	214	#define TCP_CTL 0x3f
hudakz	0:5350a66d5279	215
hudakz	0:5350a66d5279	216	#define TCP_OPT_END 0 /* End of TCP options list */
hudakz	0:5350a66d5279	217
hudakz	0:5350a66d5279	218	#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
hudakz	0:5350a66d5279	219
hudakz	0:5350a66d5279	220	#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
hudakz	0:5350a66d5279	221
hudakz	0:5350a66d5279	222	#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
hudakz	0:5350a66d5279	223
hudakz	0:5350a66d5279	224	#define ICMP_ECHO_REPLY 0
hudakz	0:5350a66d5279	225	#define ICMP_ECHO 8
hudakz	0:5350a66d5279	226
hudakz	0:5350a66d5279	227	#define ICMP6_ECHO_REPLY 129
hudakz	0:5350a66d5279	228	#define ICMP6_ECHO 128
hudakz	0:5350a66d5279	229	#define ICMP6_NEIGHBOR_SOLICITATION 135
hudakz	0:5350a66d5279	230	#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
hudakz	0:5350a66d5279	231
hudakz	0:5350a66d5279	232	#define ICMP6_FLAG_S (1 << 6)
hudakz	0:5350a66d5279	233	#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
hudakz	0:5350a66d5279	234	#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
hudakz	0:5350a66d5279	235
hudakz	0:5350a66d5279	236	/* Macros. */
hudakz	0:5350a66d5279	237
hudakz	0:5350a66d5279	238	#define BUF ((struct uip_tcpip_hdr*) &uip_buf[UIP_LLH_LEN])
hudakz	0:5350a66d5279	239	#define FBUF ((struct uip_tcpip_hdr*) &uip_reassbuf[0])
hudakz	0:5350a66d5279	240	#define ICMPBUF ((struct uip_icmpip_hdr*) &uip_buf[UIP_LLH_LEN])
hudakz	0:5350a66d5279	241	#define UDPBUF ((struct uip_udpip_hdr*) &uip_buf[UIP_LLH_LEN])
hudakz	0:5350a66d5279	242	#if UIP_STATISTICS == 1
hudakz	0:5350a66d5279	243	struct uip_stats uip_stat;
hudakz	0:5350a66d5279	244	#define UIP_STAT(s) s
hudakz	0:5350a66d5279	245	#else
hudakz	0:5350a66d5279	246	#define UIP_STAT(s)
hudakz	0:5350a66d5279	247	#endif /* UIP_STATISTICS == 1 */
hudakz	0:5350a66d5279	248
hudakz	0:5350a66d5279	249	#if UIP_LOGGING == 1
hudakz	0:5350a66d5279	250	#include <stdio.h>
hudakz	0:5350a66d5279	251	void uip_log(char* msg);
hudakz	0:5350a66d5279	252	#define UIP_LOG(m) uip_log(m)
hudakz	0:5350a66d5279	253	#else
hudakz	0:5350a66d5279	254	#define UIP_LOG(m)
hudakz	0:5350a66d5279	255	#endif /* UIP_LOGGING == 1 */
hudakz	0:5350a66d5279	256
hudakz	0:5350a66d5279	257	#if !UIP_ARCH_ADD32
hudakz	0:5350a66d5279	258
hudakz	0:5350a66d5279	259	/**
hudakz	0:5350a66d5279	260	* @brief
hudakz	0:5350a66d5279	261	* @note
hudakz	0:5350a66d5279	262	* @param
hudakz	0:5350a66d5279	263	* @retval
hudakz	0:5350a66d5279	264	*/
hudakz	0:5350a66d5279	265	void uip_add32(u8_t* op32, u16_t op16) {
hudakz	0:5350a66d5279	266	uip_acc32[3] = op32[3] + (op16 & 0xff);
hudakz	0:5350a66d5279	267	uip_acc32[2] = op32[2] + (op16 >> 8);
hudakz	0:5350a66d5279	268	uip_acc32[1] = op32[1];
hudakz	0:5350a66d5279	269	uip_acc32[0] = op32[0];
hudakz	0:5350a66d5279	270
hudakz	0:5350a66d5279	271	if(uip_acc32[2] < (op16 >> 8)) {
hudakz	0:5350a66d5279	272	++uip_acc32[1];
hudakz	0:5350a66d5279	273	if(uip_acc32[1] == 0) {
hudakz	0:5350a66d5279	274	++uip_acc32[0];
hudakz	0:5350a66d5279	275	}
hudakz	0:5350a66d5279	276	}
hudakz	0:5350a66d5279	277
hudakz	0:5350a66d5279	278	if(uip_acc32[3] < (op16 & 0xff)) {
hudakz	0:5350a66d5279	279	++uip_acc32[2];
hudakz	0:5350a66d5279	280	if(uip_acc32[2] == 0) {
hudakz	0:5350a66d5279	281	++uip_acc32[1];
hudakz	0:5350a66d5279	282	if(uip_acc32[1] == 0) {
hudakz	0:5350a66d5279	283	++uip_acc32[0];
hudakz	0:5350a66d5279	284	}
hudakz	0:5350a66d5279	285	}
hudakz	0:5350a66d5279	286	}
hudakz	0:5350a66d5279	287	}
hudakz	0:5350a66d5279	288	#endif /* UIP_ARCH_ADD32 */
hudakz	0:5350a66d5279	289
hudakz	0:5350a66d5279	290	#if !UIP_ARCH_CHKSUM
hudakz	0:5350a66d5279	291
hudakz	0:5350a66d5279	292	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	293	static u16_t chksum(u16_t sum, const u8_t* data, u16_t len) {
hudakz	0:5350a66d5279	294	u16_t t;
hudakz	0:5350a66d5279	295	const u8_t* dataptr;
hudakz	0:5350a66d5279	296	const u8_t* last_byte;
hudakz	0:5350a66d5279	297
hudakz	0:5350a66d5279	298	dataptr = data;
hudakz	0:5350a66d5279	299	last_byte = data + len - 1;
hudakz	0:5350a66d5279	300
hudakz	0:5350a66d5279	301	while(dataptr < last_byte) {
hudakz	0:5350a66d5279	302
hudakz	0:5350a66d5279	303	/* At least two more bytes */
hudakz	0:5350a66d5279	304	t = (dataptr[0] << 8) + dataptr[1];
hudakz	0:5350a66d5279	305	sum += t;
hudakz	0:5350a66d5279	306	if(sum < t) {
hudakz	0:5350a66d5279	307	sum++; /* carry */
hudakz	0:5350a66d5279	308	}
hudakz	0:5350a66d5279	309
hudakz	0:5350a66d5279	310	dataptr += 2;
hudakz	0:5350a66d5279	311	}
hudakz	0:5350a66d5279	312
hudakz	0:5350a66d5279	313	if(dataptr == last_byte) {
hudakz	0:5350a66d5279	314	t = (dataptr[0] << 8) + 0;
hudakz	0:5350a66d5279	315	sum += t;
hudakz	0:5350a66d5279	316	if(sum < t) {
hudakz	0:5350a66d5279	317	sum++; /* carry */
hudakz	0:5350a66d5279	318	}
hudakz	0:5350a66d5279	319	}
hudakz	0:5350a66d5279	320
hudakz	0:5350a66d5279	321	/* Return sum in host byte order. */
hudakz	0:5350a66d5279	322	return sum;
hudakz	0:5350a66d5279	323	}
hudakz	0:5350a66d5279	324
hudakz	0:5350a66d5279	325	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	326	u16_t uip_chksum(u16_t* data, u16_t len) {
hudakz	0:5350a66d5279	327	return htons(chksum(0, (u8_t*)data, len));
hudakz	0:5350a66d5279	328	}
hudakz	0:5350a66d5279	329
hudakz	0:5350a66d5279	330	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	331	#ifndef UIP_ARCH_IPCHKSUM
hudakz	0:5350a66d5279	332
hudakz	0:5350a66d5279	333	/**
hudakz	0:5350a66d5279	334	* @brief
hudakz	0:5350a66d5279	335	* @note
hudakz	0:5350a66d5279	336	* @param
hudakz	0:5350a66d5279	337	* @retval
hudakz	0:5350a66d5279	338	*/
hudakz	0:5350a66d5279	339	u16_t uip_ipchksum(void) {
hudakz	0:5350a66d5279	340	u16_t sum;
hudakz	0:5350a66d5279	341
hudakz	0:5350a66d5279	342	sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
hudakz	0:5350a66d5279	343	DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum);
hudakz	0:5350a66d5279	344	return(sum == 0) ? 0xffff : htons(sum);
hudakz	0:5350a66d5279	345	}
hudakz	0:5350a66d5279	346	#endif
hudakz	0:5350a66d5279	347
hudakz	0:5350a66d5279	348	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	349	static u16_t upper_layer_chksum(u8_t proto) {
hudakz	0:5350a66d5279	350	u16_t upper_layer_len;
hudakz	0:5350a66d5279	351	u16_t sum;
hudakz	0:5350a66d5279	352
hudakz	0:5350a66d5279	353	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	354	upper_layer_len = (((u16_t) (BUF->len[0]) << 8) + BUF->len[1]);
hudakz	0:5350a66d5279	355	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	356	upper_layer_len = (((u16_t) (BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
hudakz	0:5350a66d5279	357	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	358
hudakz	0:5350a66d5279	359	/* First sum pseudoheader. */
hudakz	0:5350a66d5279	360
hudakz	0:5350a66d5279	361	/* IP protocol and length fields. This addition cannot carry. */
hudakz	0:5350a66d5279	362	sum = upper_layer_len + proto;
hudakz	0:5350a66d5279	363
hudakz	0:5350a66d5279	364	/* Sum IP source and destination addresses. */
hudakz	0:5350a66d5279	365	sum = chksum(sum, (u8_t) &BUF->srcipaddr[0], 2 sizeof(uip_ipaddr_t));
hudakz	0:5350a66d5279	366
hudakz	0:5350a66d5279	367	/* Sum TCP header and data. */
hudakz	0:5350a66d5279	368	sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN], upper_layer_len);
hudakz	0:5350a66d5279	369
hudakz	0:5350a66d5279	370	return(sum == 0) ? 0xffff : htons(sum);
hudakz	0:5350a66d5279	371	}
hudakz	0:5350a66d5279	372
hudakz	0:5350a66d5279	373	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	374	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	375
hudakz	0:5350a66d5279	376	/**
hudakz	0:5350a66d5279	377	* @brief
hudakz	0:5350a66d5279	378	* @note
hudakz	0:5350a66d5279	379	* @param
hudakz	0:5350a66d5279	380	* @retval
hudakz	0:5350a66d5279	381	*/
hudakz	0:5350a66d5279	382	u16_t uip_icmp6chksum(void) {
hudakz	0:5350a66d5279	383	return upper_layer_chksum(UIP_PROTO_ICMP6);
hudakz	0:5350a66d5279	384	}
hudakz	0:5350a66d5279	385	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	386
hudakz	0:5350a66d5279	387	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	388	u16_t uip_tcpchksum(void) {
hudakz	0:5350a66d5279	389	return upper_layer_chksum(UIP_PROTO_TCP);
hudakz	0:5350a66d5279	390	}
hudakz	0:5350a66d5279	391
hudakz	0:5350a66d5279	392	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	393	#if UIP_UDP_CHECKSUMS
hudakz	0:5350a66d5279	394
hudakz	0:5350a66d5279	395	/**
hudakz	0:5350a66d5279	396	* @brief
hudakz	0:5350a66d5279	397	* @note
hudakz	0:5350a66d5279	398	* @param
hudakz	0:5350a66d5279	399	* @retval
hudakz	0:5350a66d5279	400	*/
hudakz	0:5350a66d5279	401	u16_t uip_udpchksum(void) {
hudakz	0:5350a66d5279	402	return upper_layer_chksum(UIP_PROTO_UDP);
hudakz	0:5350a66d5279	403	}
hudakz	0:5350a66d5279	404	#endif /* UIP_UDP_CHECKSUMS */
hudakz	0:5350a66d5279	405	#endif /* UIP_ARCH_CHKSUM */
hudakz	0:5350a66d5279	406
hudakz	0:5350a66d5279	407	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	408	void uip_init(void) {
hudakz	0:5350a66d5279	409	for(c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	0:5350a66d5279	410	uip_listenports[c] = 0;
hudakz	0:5350a66d5279	411	}
hudakz	0:5350a66d5279	412
hudakz	0:5350a66d5279	413	for(c = 0; c < UIP_CONNS; ++c) {
hudakz	0:5350a66d5279	414	uip_conns[c].tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	415	}
hudakz	0:5350a66d5279	416
hudakz	0:5350a66d5279	417	#if UIP_ACTIVE_OPEN
hudakz	0:5350a66d5279	418	lastport = 1024;
hudakz	0:5350a66d5279	419	#endif /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	420
hudakz	0:5350a66d5279	421	#if UIP_UDP
hudakz	0:5350a66d5279	422	for(c = 0; c < UIP_UDP_CONNS; ++c) {
hudakz	0:5350a66d5279	423	uip_udp_conns[c].lport = 0;
hudakz	0:5350a66d5279	424	}
hudakz	0:5350a66d5279	425	#endif /* UIP_UDP */
hudakz	0:5350a66d5279	426
hudakz	0:5350a66d5279	427	/* IPv4 initialization. */
hudakz	0:5350a66d5279	428
hudakz	0:5350a66d5279	429	#if UIP_FIXEDADDR == 0
hudakz	0:5350a66d5279	430	/* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
hudakz	0:5350a66d5279	431	#endif /* UIP_FIXEDADDR */
hudakz	0:5350a66d5279	432	}
hudakz	0:5350a66d5279	433
hudakz	0:5350a66d5279	434	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	435	#if UIP_ACTIVE_OPEN
hudakz	0:5350a66d5279	436
hudakz	0:5350a66d5279	437	/**
hudakz	0:5350a66d5279	438	* @brief
hudakz	0:5350a66d5279	439	* @note
hudakz	0:5350a66d5279	440	* @param
hudakz	0:5350a66d5279	441	* @retval
hudakz	0:5350a66d5279	442	*/
hudakz	0:5350a66d5279	443	struct uip_conn* uip_connect(uip_ipaddr_t* ripaddr, u16_t rport) {
hudakz	0:5350a66d5279	444	register struct uip_conn* conn, *cconn;
hudakz	0:5350a66d5279	445
hudakz	0:5350a66d5279	446	/* Find an unused local port. */
hudakz	0:5350a66d5279	447
hudakz	0:5350a66d5279	448	again:
hudakz	0:5350a66d5279	449	++lastport;
hudakz	0:5350a66d5279	450
hudakz	0:5350a66d5279	451	if(lastport >= 32000) {
hudakz	0:5350a66d5279	452	lastport = 4096;
hudakz	0:5350a66d5279	453	}
hudakz	0:5350a66d5279	454
hudakz	0:5350a66d5279	455	/* Check if this port is already in use, and if so try to find
hudakz	0:5350a66d5279	456	another one. */
hudakz	0:5350a66d5279	457	for(c = 0; c < UIP_CONNS; ++c) {
hudakz	0:5350a66d5279	458	conn = &uip_conns[c];
hudakz	0:5350a66d5279	459	if(conn->tcpstateflags != UIP_CLOSED && conn->lport == htons(lastport)) {
hudakz	0:5350a66d5279	460	goto again;
hudakz	0:5350a66d5279	461	}
hudakz	0:5350a66d5279	462	}
hudakz	0:5350a66d5279	463
hudakz	0:5350a66d5279	464	conn = 0;
hudakz	0:5350a66d5279	465	for(c = 0; c < UIP_CONNS; ++c) {
hudakz	0:5350a66d5279	466	cconn = &uip_conns[c];
hudakz	0:5350a66d5279	467	if(cconn->tcpstateflags == UIP_CLOSED) {
hudakz	0:5350a66d5279	468	conn = cconn;
hudakz	0:5350a66d5279	469	break;
hudakz	0:5350a66d5279	470	}
hudakz	0:5350a66d5279	471
hudakz	0:5350a66d5279	472	if(cconn->tcpstateflags == UIP_TIME_WAIT) {
hudakz	0:5350a66d5279	473	if(conn == 0 \|\| cconn->timer > conn->timer) {
hudakz	0:5350a66d5279	474	conn = cconn;
hudakz	0:5350a66d5279	475	}
hudakz	0:5350a66d5279	476	}
hudakz	0:5350a66d5279	477	}
hudakz	0:5350a66d5279	478
hudakz	0:5350a66d5279	479	if(conn == 0) {
hudakz	0:5350a66d5279	480	return 0;
hudakz	0:5350a66d5279	481	}
hudakz	0:5350a66d5279	482
hudakz	0:5350a66d5279	483	conn->tcpstateflags = UIP_SYN_SENT;
hudakz	0:5350a66d5279	484
hudakz	0:5350a66d5279	485	conn->snd_nxt[0] = iss[0];
hudakz	0:5350a66d5279	486	conn->snd_nxt[1] = iss[1];
hudakz	0:5350a66d5279	487	conn->snd_nxt[2] = iss[2];
hudakz	0:5350a66d5279	488	conn->snd_nxt[3] = iss[3];
hudakz	0:5350a66d5279	489
hudakz	0:5350a66d5279	490	conn->initialmss = conn->mss = UIP_TCP_MSS;
hudakz	0:5350a66d5279	491
hudakz	0:5350a66d5279	492	conn->len = 1; /* TCP length of the SYN is one. */
hudakz	0:5350a66d5279	493	conn->nrtx = 0;
hudakz	0:5350a66d5279	494	conn->timer = 1; /* Send the SYN next time around. */
hudakz	0:5350a66d5279	495	conn->rto = UIP_RTO;
hudakz	0:5350a66d5279	496	conn->sa = 0;
hudakz	0:5350a66d5279	497	conn->sv = 16; /* Initial value of the RTT variance. */
hudakz	0:5350a66d5279	498	conn->lport = htons(lastport);
hudakz	0:5350a66d5279	499	conn->rport = rport;
hudakz	0:5350a66d5279	500	uip_ipaddr_copy(&conn->ripaddr, ripaddr);
hudakz	0:5350a66d5279	501
hudakz	0:5350a66d5279	502	return conn;
hudakz	0:5350a66d5279	503	}
hudakz	0:5350a66d5279	504	#endif /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	505
hudakz	0:5350a66d5279	506	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	507
hudakz	0:5350a66d5279	508	#if UIP_UDP
hudakz	0:5350a66d5279	509
hudakz	0:5350a66d5279	510	/**
hudakz	0:5350a66d5279	511	* @brief
hudakz	0:5350a66d5279	512	* @note
hudakz	0:5350a66d5279	513	* @param
hudakz	0:5350a66d5279	514	* @retval
hudakz	0:5350a66d5279	515	*/
hudakz	0:5350a66d5279	516	struct uip_udp_conn* uip_udp_new(uip_ipaddr_t* ripaddr, u16_t rport) {
hudakz	0:5350a66d5279	517	register struct uip_udp_conn* conn;
hudakz	0:5350a66d5279	518
hudakz	0:5350a66d5279	519	/* Find an unused local port. */
hudakz	0:5350a66d5279	520
hudakz	0:5350a66d5279	521	again:
hudakz	0:5350a66d5279	522	++lastport;
hudakz	0:5350a66d5279	523
hudakz	0:5350a66d5279	524	if(lastport >= 32000) {
hudakz	0:5350a66d5279	525	lastport = 4096;
hudakz	0:5350a66d5279	526	}
hudakz	0:5350a66d5279	527
hudakz	0:5350a66d5279	528	for(c = 0; c < UIP_UDP_CONNS; ++c) {
hudakz	0:5350a66d5279	529	if(uip_udp_conns[c].lport == htons(lastport)) {
hudakz	0:5350a66d5279	530	goto again;
hudakz	0:5350a66d5279	531	}
hudakz	0:5350a66d5279	532	}
hudakz	0:5350a66d5279	533
hudakz	0:5350a66d5279	534	conn = 0;
hudakz	0:5350a66d5279	535	for(c = 0; c < UIP_UDP_CONNS; ++c) {
hudakz	0:5350a66d5279	536	if(uip_udp_conns[c].lport == 0) {
hudakz	0:5350a66d5279	537	conn = &uip_udp_conns[c];
hudakz	0:5350a66d5279	538	break;
hudakz	0:5350a66d5279	539	}
hudakz	0:5350a66d5279	540	}
hudakz	0:5350a66d5279	541
hudakz	0:5350a66d5279	542	if(conn == 0) {
hudakz	0:5350a66d5279	543	return 0;
hudakz	0:5350a66d5279	544	}
hudakz	0:5350a66d5279	545
hudakz	0:5350a66d5279	546	conn->lport = HTONS(lastport);
hudakz	0:5350a66d5279	547	conn->rport = rport;
hudakz	0:5350a66d5279	548	if(ripaddr == NULL) {
hudakz	0:5350a66d5279	549	memset(conn->ripaddr, 0, sizeof(uip_ipaddr_t));
hudakz	0:5350a66d5279	550	}
hudakz	0:5350a66d5279	551	else {
hudakz	0:5350a66d5279	552	uip_ipaddr_copy(&conn->ripaddr, ripaddr);
hudakz	0:5350a66d5279	553	}
hudakz	0:5350a66d5279	554
hudakz	0:5350a66d5279	555	conn->ttl = UIP_TTL;
hudakz	0:5350a66d5279	556
hudakz	0:5350a66d5279	557	return conn;
hudakz	0:5350a66d5279	558	}
hudakz	0:5350a66d5279	559	#endif /* UIP_UDP */
hudakz	0:5350a66d5279	560
hudakz	0:5350a66d5279	561	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	562	void uip_unlisten(u16_t port) {
hudakz	0:5350a66d5279	563	for(c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	0:5350a66d5279	564	if(uip_listenports[c] == port) {
hudakz	0:5350a66d5279	565	uip_listenports[c] = 0;
hudakz	0:5350a66d5279	566	return;
hudakz	0:5350a66d5279	567	}
hudakz	0:5350a66d5279	568	}
hudakz	0:5350a66d5279	569	}
hudakz	0:5350a66d5279	570
hudakz	0:5350a66d5279	571	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	572	void uip_listen(u16_t port) {
hudakz	0:5350a66d5279	573	for(c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	0:5350a66d5279	574	if(uip_listenports[c] == 0) {
hudakz	0:5350a66d5279	575	uip_listenports[c] = port;
hudakz	0:5350a66d5279	576	return;
hudakz	0:5350a66d5279	577	}
hudakz	0:5350a66d5279	578	}
hudakz	0:5350a66d5279	579	}
hudakz	0:5350a66d5279	580
hudakz	0:5350a66d5279	581	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	582	/* XXX: IP fragment reassembly: not well-tested. */
hudakz	0:5350a66d5279	583	#if UIP_REASSEMBLY && !UIP_CONF_IPV6
hudakz	0:5350a66d5279	584	#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
hudakz	0:5350a66d5279	585	static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
hudakz	0:5350a66d5279	586	static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
hudakz	0:5350a66d5279	587	static const u8_t bitmap_bits[8] = { 0xff, 0x7f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01 };
hudakz	0:5350a66d5279	588	static u16_t uip_reasslen;
hudakz	0:5350a66d5279	589	static u8_t uip_reassflags;
hudakz	0:5350a66d5279	590	#define UIP_REASS_FLAG_LASTFRAG 0x01
hudakz	0:5350a66d5279	591	static u8_t uip_reasstmr;
hudakz	0:5350a66d5279	592
hudakz	0:5350a66d5279	593	#define IP_MF 0x20
hudakz	0:5350a66d5279	594
hudakz	0:5350a66d5279	595	/**
hudakz	0:5350a66d5279	596	* @brief
hudakz	0:5350a66d5279	597	* @note
hudakz	0:5350a66d5279	598	* @param
hudakz	0:5350a66d5279	599	* @retval
hudakz	0:5350a66d5279	600	*/
hudakz	0:5350a66d5279	601	static u8_t uip_reass(void) {
hudakz	0:5350a66d5279	602	u16_t offset, len;
hudakz	0:5350a66d5279	603	u16_t i;
hudakz	0:5350a66d5279	604
hudakz	0:5350a66d5279	605	/* If ip_reasstmr is zero, no packet is present in the buffer, so we
hudakz	0:5350a66d5279	606	write the IP header of the fragment into the reassembly
hudakz	0:5350a66d5279	607	buffer. The timer is updated with the maximum age. */
hudakz	0:5350a66d5279	608
hudakz	0:5350a66d5279	609	if(uip_reasstmr == 0) {
hudakz	0:5350a66d5279	610	memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
hudakz	0:5350a66d5279	611	uip_reasstmr = UIP_REASS_MAXAGE;
hudakz	0:5350a66d5279	612	uip_reassflags = 0;
hudakz	0:5350a66d5279	613
hudakz	0:5350a66d5279	614	/* Clear the bitmap. */
hudakz	0:5350a66d5279	615	memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
hudakz	0:5350a66d5279	616	}
hudakz	0:5350a66d5279	617
hudakz	0:5350a66d5279	618	/* Check if the incoming fragment matches the one currently present
hudakz	0:5350a66d5279	619	in the reasembly buffer. If so, we proceed with copying the
hudakz	0:5350a66d5279	620	fragment into the buffer. */
hudakz	0:5350a66d5279	621	if
hudakz	0:5350a66d5279	622	(
hudakz	0:5350a66d5279	623	BUF->srcipaddr[0] == FBUF->srcipaddr[0]
hudakz	0:5350a66d5279	624	&& BUF->srcipaddr[1] == FBUF->srcipaddr[1]
hudakz	0:5350a66d5279	625	&& BUF->destipaddr[0] == FBUF->destipaddr[0]
hudakz	0:5350a66d5279	626	&& BUF->destipaddr[1] == FBUF->destipaddr[1]
hudakz	0:5350a66d5279	627	&& BUF->ipid[0] == FBUF->ipid[0]
hudakz	0:5350a66d5279	628	&& BUF->ipid[1] == FBUF->ipid[1]
hudakz	0:5350a66d5279	629	) {
hudakz	0:5350a66d5279	630	len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
hudakz	0:5350a66d5279	631	offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
hudakz	0:5350a66d5279	632
hudakz	0:5350a66d5279	633	/* If the offset or the offset + fragment length overflows the
hudakz	0:5350a66d5279	634	reassembly buffer, we discard the entire packet. */
hudakz	0:5350a66d5279	635	if(offset > UIP_REASS_BUFSIZE \|\| offset + len > UIP_REASS_BUFSIZE) {
hudakz	0:5350a66d5279	636	uip_reasstmr = 0;
hudakz	0:5350a66d5279	637	goto nullreturn;
hudakz	0:5350a66d5279	638	}
hudakz	0:5350a66d5279	639
hudakz	0:5350a66d5279	640	/* Copy the fragment into the reassembly buffer, at the right
hudakz	0:5350a66d5279	641	offset. */
hudakz	0:5350a66d5279	642	memcpy(&uip_reassbuf[UIP_IPH_LEN + offset], (char)BUF + (int)((BUF->vhl & 0x0f) 4), len);
hudakz	0:5350a66d5279	643
hudakz	0:5350a66d5279	644	/* Update the bitmap. */
hudakz	0:5350a66d5279	645	if(offset / (8 * 8) == (offset + len) / (8 * 8)) {
hudakz	0:5350a66d5279	646
hudakz	0:5350a66d5279	647	/* If the two endpoints are in the same byte, we only update
hudakz	0:5350a66d5279	648	that byte. */
hudakz	0:5350a66d5279	649	uip_reassbitmap[offset / (8 * 8)] \|= bitmap_bits[(offset / 8) & 7] &~bitmap_bits[((offset + len) / 8) & 7];
hudakz	0:5350a66d5279	650	}
hudakz	0:5350a66d5279	651	else {
hudakz	0:5350a66d5279	652
hudakz	0:5350a66d5279	653	/* If the two endpoints are in different bytes, we update the
hudakz	0:5350a66d5279	654	bytes in the endpoints and fill the stuff inbetween with
hudakz	0:5350a66d5279	655	0xff. */
hudakz	0:5350a66d5279	656	uip_reassbitmap[offset / (8 * 8)] \|= bitmap_bits[(offset / 8) & 7];
hudakz	0:5350a66d5279	657	for(i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
hudakz	0:5350a66d5279	658	uip_reassbitmap[i] = 0xff;
hudakz	0:5350a66d5279	659	}
hudakz	0:5350a66d5279	660
hudakz	0:5350a66d5279	661	uip_reassbitmap[(offset + len) / (8 * 8)] \|= ~bitmap_bits[((offset + len) / 8) & 7];
hudakz	0:5350a66d5279	662	}
hudakz	0:5350a66d5279	663
hudakz	0:5350a66d5279	664	/* If this fragment has the More Fragments flag set to zero, we
hudakz	0:5350a66d5279	665	know that this is the last fragment, so we can calculate the
hudakz	0:5350a66d5279	666	size of the entire packet. We also set the
hudakz	0:5350a66d5279	667	IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
hudakz	0:5350a66d5279	668	the final fragment. */
hudakz	0:5350a66d5279	669	if((BUF->ipoffset[0] & IP_MF) == 0) {
hudakz	0:5350a66d5279	670	uip_reassflags \|= UIP_REASS_FLAG_LASTFRAG;
hudakz	0:5350a66d5279	671	uip_reasslen = offset + len;
hudakz	0:5350a66d5279	672	}
hudakz	0:5350a66d5279	673
hudakz	0:5350a66d5279	674	/* Finally, we check if we have a full packet in the buffer. We do
hudakz	0:5350a66d5279	675	this by checking if we have the last fragment and if all bits
hudakz	0:5350a66d5279	676	in the bitmap are set. */
hudakz	0:5350a66d5279	677	if(uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
hudakz	0:5350a66d5279	678
hudakz	0:5350a66d5279	679	/* Check all bytes up to and including all but the last byte in
hudakz	0:5350a66d5279	680	the bitmap. */
hudakz	0:5350a66d5279	681	for(i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
hudakz	0:5350a66d5279	682	if(uip_reassbitmap[i] != 0xff) {
hudakz	0:5350a66d5279	683	goto nullreturn;
hudakz	0:5350a66d5279	684	}
hudakz	0:5350a66d5279	685	}
hudakz	0:5350a66d5279	686
hudakz	0:5350a66d5279	687	/* Check the last byte in the bitmap. It should contain just the
hudakz	0:5350a66d5279	688	right amount of bits. */
hudakz	0:5350a66d5279	689	if(uip_reassbitmap[uip_reasslen / (8 * 8)] != (u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
hudakz	0:5350a66d5279	690	goto nullreturn;
hudakz	0:5350a66d5279	691	}
hudakz	0:5350a66d5279	692
hudakz	0:5350a66d5279	693	/* If we have come this far, we have a full packet in the
hudakz	0:5350a66d5279	694	buffer, so we allocate a pbuf and copy the packet into it. We
hudakz	0:5350a66d5279	695	also reset the timer. */
hudakz	0:5350a66d5279	696	uip_reasstmr = 0;
hudakz	0:5350a66d5279	697	memcpy(BUF, FBUF, uip_reasslen);
hudakz	0:5350a66d5279	698
hudakz	0:5350a66d5279	699	/* Pretend to be a "normal" (i.e., not fragmented) IP packet
hudakz	0:5350a66d5279	700	from now on. */
hudakz	0:5350a66d5279	701	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
hudakz	0:5350a66d5279	702	BUF->len[0] = uip_reasslen >> 8;
hudakz	0:5350a66d5279	703	BUF->len[1] = uip_reasslen & 0xff;
hudakz	0:5350a66d5279	704	BUF->ipchksum = 0;
hudakz	0:5350a66d5279	705	BUF->ipchksum = ~(uip_ipchksum());
hudakz	0:5350a66d5279	706
hudakz	0:5350a66d5279	707	return uip_reasslen;
hudakz	0:5350a66d5279	708	}
hudakz	0:5350a66d5279	709	}
hudakz	0:5350a66d5279	710
hudakz	0:5350a66d5279	711	nullreturn:
hudakz	0:5350a66d5279	712	return 0;
hudakz	0:5350a66d5279	713	}
hudakz	0:5350a66d5279	714	#endif /* UIP_REASSEMBLY */
hudakz	0:5350a66d5279	715
hudakz	0:5350a66d5279	716	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	717	static void uip_add_rcv_nxt(u16_t n) {
hudakz	0:5350a66d5279	718	uip_add32(uip_conn->rcv_nxt, n);
hudakz	0:5350a66d5279	719	uip_conn->rcv_nxt[0] = uip_acc32[0];
hudakz	0:5350a66d5279	720	uip_conn->rcv_nxt[1] = uip_acc32[1];
hudakz	0:5350a66d5279	721	uip_conn->rcv_nxt[2] = uip_acc32[2];
hudakz	0:5350a66d5279	722	uip_conn->rcv_nxt[3] = uip_acc32[3];
hudakz	0:5350a66d5279	723	}
hudakz	0:5350a66d5279	724
hudakz	0:5350a66d5279	725	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	726	void uip_process(u8_t flag) {
hudakz	0:5350a66d5279	727	register struct uip_conn* uip_connr = uip_conn;
hudakz	0:5350a66d5279	728
hudakz	0:5350a66d5279	729	#if UIP_UDP
hudakz	0:5350a66d5279	730	if(flag == UIP_UDP_SEND_CONN) {
hudakz	0:5350a66d5279	731	goto udp_send;
hudakz	0:5350a66d5279	732	}
hudakz	0:5350a66d5279	733	#endif /* UIP_UDP */
hudakz	0:5350a66d5279	734
hudakz	0:5350a66d5279	735	uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
hudakz	0:5350a66d5279	736
hudakz	0:5350a66d5279	737	/* Check if we were invoked because of a poll request for a
hudakz	0:5350a66d5279	738	particular connection. */
hudakz	0:5350a66d5279	739	if(flag == UIP_POLL_REQUEST) {
hudakz	0:5350a66d5279	740	if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED && !uip_outstanding(uip_connr)) {
hudakz	0:5350a66d5279	741	uip_flags = UIP_POLL;
hudakz	0:5350a66d5279	742	UIP_APPCALL();
hudakz	0:5350a66d5279	743	goto appsend;
hudakz	0:5350a66d5279	744	}
hudakz	0:5350a66d5279	745
hudakz	0:5350a66d5279	746	goto drop;
hudakz	0:5350a66d5279	747
hudakz	0:5350a66d5279	748	/* Check if we were invoked because of the perodic timer fireing. */
hudakz	0:5350a66d5279	749	}
hudakz	0:5350a66d5279	750	else
hudakz	0:5350a66d5279	751	if(flag == UIP_TIMER)
hudakz	0:5350a66d5279	752	{
hudakz	0:5350a66d5279	753	#if UIP_REASSEMBLY
hudakz	0:5350a66d5279	754	if(uip_reasstmr != 0) {
hudakz	0:5350a66d5279	755	--uip_reasstmr;
hudakz	0:5350a66d5279	756	}
hudakz	0:5350a66d5279	757	#endif /* UIP_REASSEMBLY */
hudakz	0:5350a66d5279	758
hudakz	0:5350a66d5279	759	/* Increase the initial sequence number. */
hudakz	0:5350a66d5279	760
hudakz	0:5350a66d5279	761	if(++iss[3] == 0) {
hudakz	0:5350a66d5279	762	if(++iss[2] == 0) {
hudakz	0:5350a66d5279	763	if(++iss[1] == 0) {
hudakz	0:5350a66d5279	764	++iss[0];
hudakz	0:5350a66d5279	765	}
hudakz	0:5350a66d5279	766	}
hudakz	0:5350a66d5279	767	}
hudakz	0:5350a66d5279	768
hudakz	0:5350a66d5279	769	/* Reset the length variables. */
hudakz	0:5350a66d5279	770	uip_len = 0;
hudakz	0:5350a66d5279	771	uip_slen = 0;
hudakz	0:5350a66d5279	772
hudakz	0:5350a66d5279	773	/* Check if the connection is in a state in which we simply wait
hudakz	0:5350a66d5279	774	for the connection to time out. If so, we increase the
hudakz	0:5350a66d5279	775	connection's timer and remove the connection if it times
hudakz	0:5350a66d5279	776	out. */
hudakz	0:5350a66d5279	777	if(uip_connr->tcpstateflags == UIP_TIME_WAIT \|\| uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
hudakz	0:5350a66d5279	778	++(uip_connr->timer);
hudakz	0:5350a66d5279	779	if(uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
hudakz	0:5350a66d5279	780	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	781	}
hudakz	0:5350a66d5279	782	}
hudakz	0:5350a66d5279	783	else
hudakz	0:5350a66d5279	784	if(uip_connr->tcpstateflags != UIP_CLOSED) {
hudakz	0:5350a66d5279	785
hudakz	0:5350a66d5279	786	/* If the connection has outstanding data, we increase the
hudakz	0:5350a66d5279	787	connection's timer and see if it has reached the RTO value
hudakz	0:5350a66d5279	788	in which case we retransmit. */
hudakz	0:5350a66d5279	789	if(uip_outstanding(uip_connr)) {
hudakz	0:5350a66d5279	790	if(uip_connr->timer-- == 0) {
hudakz	0:5350a66d5279	791	if
hudakz	0:5350a66d5279	792	(
hudakz	0:5350a66d5279	793	uip_connr->nrtx == UIP_MAXRTX
hudakz	0:5350a66d5279	794	\|\| (
hudakz	0:5350a66d5279	795	(uip_connr->tcpstateflags == UIP_SYN_SENT \|\| uip_connr->tcpstateflags == UIP_SYN_RCVD)
hudakz	0:5350a66d5279	796	&& uip_connr->nrtx == UIP_MAXSYNRTX
hudakz	0:5350a66d5279	797	)
hudakz	0:5350a66d5279	798	) {
hudakz	0:5350a66d5279	799	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	800
hudakz	0:5350a66d5279	801	/* We call UIP_APPCALL() with uip_flags set to
hudakz	0:5350a66d5279	802	UIP_TIMEDOUT to inform the application that the
hudakz	0:5350a66d5279	803	connection has timed out. */
hudakz	0:5350a66d5279	804	uip_flags = UIP_TIMEDOUT;
hudakz	0:5350a66d5279	805	UIP_APPCALL();
hudakz	0:5350a66d5279	806
hudakz	0:5350a66d5279	807	/* We also send a reset packet to the remote host. */
hudakz	0:5350a66d5279	808	BUF->flags = TCP_RST \| TCP_ACK;
hudakz	0:5350a66d5279	809	goto tcp_send_nodata;
hudakz	0:5350a66d5279	810	}
hudakz	0:5350a66d5279	811
hudakz	0:5350a66d5279	812	/* Exponential backoff. */
hudakz	0:5350a66d5279	813	uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4 ? 4 : uip_connr->nrtx);
hudakz	0:5350a66d5279	814	++(uip_connr->nrtx);
hudakz	0:5350a66d5279	815
hudakz	0:5350a66d5279	816	/* Ok, so we need to retransmit. We do this differently
hudakz	0:5350a66d5279	817	depending on which state we are in. In ESTABLISHED, we
hudakz	0:5350a66d5279	818	call upon the application so that it may prepare the
hudakz	0:5350a66d5279	819	data for the retransmit. In SYN_RCVD, we resend the
hudakz	0:5350a66d5279	820	SYNACK that we sent earlier and in LAST_ACK we have to
hudakz	0:5350a66d5279	821	retransmit our FINACK. */
hudakz	0:5350a66d5279	822	UIP_STAT(++uip_stat.tcp.rexmit);
hudakz	0:5350a66d5279	823	switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
hudakz	0:5350a66d5279	824	case UIP_SYN_RCVD:
hudakz	0:5350a66d5279	825	/* In the SYN_RCVD state, we should retransmit our
hudakz	0:5350a66d5279	826	SYNACK. */
hudakz	0:5350a66d5279	827	goto tcp_send_synack;
hudakz	0:5350a66d5279	828
hudakz	0:5350a66d5279	829	#if UIP_ACTIVE_OPEN
hudakz	0:5350a66d5279	830
hudakz	0:5350a66d5279	831	case UIP_SYN_SENT:
hudakz	0:5350a66d5279	832	/* In the SYN_SENT state, we retransmit out SYN. */
hudakz	0:5350a66d5279	833	BUF->flags = 0;
hudakz	0:5350a66d5279	834	goto tcp_send_syn;
hudakz	0:5350a66d5279	835	#endif /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	836
hudakz	0:5350a66d5279	837	case UIP_ESTABLISHED:
hudakz	0:5350a66d5279	838	/* In the ESTABLISHED state, we call upon the application
hudakz	0:5350a66d5279	839	to do the actual retransmit after which we jump into
hudakz	0:5350a66d5279	840	the code for sending out the packet (the apprexmit
hudakz	0:5350a66d5279	841	label). */
hudakz	0:5350a66d5279	842	uip_flags = UIP_REXMIT;
hudakz	0:5350a66d5279	843	UIP_APPCALL();
hudakz	0:5350a66d5279	844	goto apprexmit;
hudakz	0:5350a66d5279	845
hudakz	0:5350a66d5279	846	case UIP_FIN_WAIT_1:
hudakz	0:5350a66d5279	847	case UIP_CLOSING:
hudakz	0:5350a66d5279	848	case UIP_LAST_ACK:
hudakz	0:5350a66d5279	849	/* In all these states we should retransmit a FINACK. */
hudakz	0:5350a66d5279	850	goto tcp_send_finack;
hudakz	0:5350a66d5279	851	}
hudakz	0:5350a66d5279	852	}
hudakz	0:5350a66d5279	853	}
hudakz	0:5350a66d5279	854	else
hudakz	0:5350a66d5279	855	if((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) {
hudakz	0:5350a66d5279	856
hudakz	0:5350a66d5279	857	/* If there was no need for a retransmission, we poll the
hudakz	0:5350a66d5279	858	application for new data. */
hudakz	0:5350a66d5279	859	uip_flags = UIP_POLL;
hudakz	0:5350a66d5279	860	UIP_APPCALL();
hudakz	0:5350a66d5279	861	goto appsend;
hudakz	0:5350a66d5279	862	}
hudakz	0:5350a66d5279	863	}
hudakz	0:5350a66d5279	864
hudakz	0:5350a66d5279	865	goto drop;
hudakz	0:5350a66d5279	866	}
hudakz	0:5350a66d5279	867
hudakz	0:5350a66d5279	868	#if UIP_UDP
hudakz	0:5350a66d5279	869	if(flag == UIP_UDP_TIMER) {
hudakz	0:5350a66d5279	870	if(uip_udp_conn->lport != 0) {
hudakz	0:5350a66d5279	871	uip_conn = NULL;
hudakz	0:5350a66d5279	872	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
hudakz	0:5350a66d5279	873	uip_len = uip_slen = 0;
hudakz	0:5350a66d5279	874	uip_flags = UIP_POLL;
hudakz	0:5350a66d5279	875	UIP_UDP_APPCALL();
hudakz	0:5350a66d5279	876	goto udp_send;
hudakz	0:5350a66d5279	877	}
hudakz	0:5350a66d5279	878	else {
hudakz	0:5350a66d5279	879	goto drop;
hudakz	0:5350a66d5279	880	}
hudakz	0:5350a66d5279	881	}
hudakz	0:5350a66d5279	882	#endif
hudakz	0:5350a66d5279	883	/* This is where the input processing starts. */
hudakz	0:5350a66d5279	884
hudakz	0:5350a66d5279	885	UIP_STAT(++uip_stat.ip.recv);
hudakz	0:5350a66d5279	886
hudakz	0:5350a66d5279	887	/* Start of IP input header processing code. */
hudakz	0:5350a66d5279	888	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	889	/* Check validity of the IP header. */
hudakz	0:5350a66d5279	890
hudakz	0:5350a66d5279	891	if((BUF->vtc & 0xf0) != 0x60) {
hudakz	0:5350a66d5279	892
hudakz	0:5350a66d5279	893	/* IP version and header length. */
hudakz	0:5350a66d5279	894	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	895	UIP_STAT(++uip_stat.ip.vhlerr);
hudakz	0:5350a66d5279	896	UIP_LOG("ipv6: invalid version.");
hudakz	0:5350a66d5279	897	goto drop;
hudakz	0:5350a66d5279	898	}
hudakz	0:5350a66d5279	899
hudakz	0:5350a66d5279	900	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	901	/* Check validity of the IP header. */
hudakz	0:5350a66d5279	902
hudakz	0:5350a66d5279	903	if(BUF->vhl != 0x45) {
hudakz	0:5350a66d5279	904
hudakz	0:5350a66d5279	905	/* IP version and header length. */
hudakz	0:5350a66d5279	906	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	907	UIP_STAT(++uip_stat.ip.vhlerr);
hudakz	0:5350a66d5279	908	UIP_LOG("ip: invalid version or header length.");
hudakz	0:5350a66d5279	909	goto drop;
hudakz	0:5350a66d5279	910	}
hudakz	0:5350a66d5279	911	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	912
hudakz	0:5350a66d5279	913	/* Check the size of the packet. If the size reported to us in
hudakz	0:5350a66d5279	914	uip_len is smaller the size reported in the IP header, we assume
hudakz	0:5350a66d5279	915	that the packet has been corrupted in transit. If the size of
hudakz	0:5350a66d5279	916	uip_len is larger than the size reported in the IP packet header,
hudakz	0:5350a66d5279	917	the packet has been padded and we set uip_len to the correct
hudakz	0:5350a66d5279	918	value.. */
hudakz	0:5350a66d5279	919
hudakz	0:5350a66d5279	920	if((BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
hudakz	0:5350a66d5279	921	uip_len = (BUF->len[0] << 8) + BUF->len[1];
hudakz	0:5350a66d5279	922	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	923	uip_len += 40; /* The length reported in the IPv6 header is the
hudakz	0:5350a66d5279	924	length of the payload that follows the
hudakz	0:5350a66d5279	925	header. However, uIP uses the uip_len variable
hudakz	0:5350a66d5279	926	for holding the size of the entire packet,
hudakz	0:5350a66d5279	927	including the IP header. For IPv4 this is not a
hudakz	0:5350a66d5279	928	problem as the length field in the IPv4 header
hudakz	0:5350a66d5279	929	contains the length of the entire packet. But
hudakz	0:5350a66d5279	930	for IPv6 we need to add the size of the IPv6
hudakz	0:5350a66d5279	931	header (40 bytes). */
hudakz	0:5350a66d5279	932	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	933	}
hudakz	0:5350a66d5279	934	else {
hudakz	0:5350a66d5279	935	UIP_LOG("ip: packet shorter than reported in IP header.");
hudakz	0:5350a66d5279	936	goto drop;
hudakz	0:5350a66d5279	937	}
hudakz	0:5350a66d5279	938
hudakz	0:5350a66d5279	939	#if !UIP_CONF_IPV6
hudakz	0:5350a66d5279	940	/* Check the fragment flag. */
hudakz	0:5350a66d5279	941
hudakz	0:5350a66d5279	942	if((BUF->ipoffset[0] & 0x3f) != 0 \|\| BUF->ipoffset[1] != 0)
hudakz	0:5350a66d5279	943	{
hudakz	0:5350a66d5279	944	#if UIP_REASSEMBLY
hudakz	0:5350a66d5279	945	uip_len = uip_reass();
hudakz	0:5350a66d5279	946	if(uip_len == 0) {
hudakz	0:5350a66d5279	947	goto drop;
hudakz	0:5350a66d5279	948	}
hudakz	0:5350a66d5279	949
hudakz	0:5350a66d5279	950	#else /* UIP_REASSEMBLY */
hudakz	0:5350a66d5279	951	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	952	UIP_STAT(++uip_stat.ip.fragerr);
hudakz	0:5350a66d5279	953	UIP_LOG("ip: fragment dropped.");
hudakz	0:5350a66d5279	954	goto drop;
hudakz	0:5350a66d5279	955	#endif /* UIP_REASSEMBLY */
hudakz	0:5350a66d5279	956	}
hudakz	0:5350a66d5279	957	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	958
hudakz	0:5350a66d5279	959	if(uip_ipaddr_cmp(uip_hostaddr, all_zeroes_addr))
hudakz	0:5350a66d5279	960	{
hudakz	0:5350a66d5279	961	/* If we are configured to use ping IP address configuration and
hudakz	0:5350a66d5279	962	hasn't been assigned an IP address yet, we accept all ICMP
hudakz	0:5350a66d5279	963	packets. */
hudakz	0:5350a66d5279	964	#if UIP_PINGADDRCONF && !UIP_CONF_IPV6
hudakz	0:5350a66d5279	965	if(BUF->proto == UIP_PROTO_ICMP) {
hudakz	0:5350a66d5279	966	UIP_LOG("ip: possible ping config packet received.");
hudakz	0:5350a66d5279	967	goto icmp_input;
hudakz	0:5350a66d5279	968	}
hudakz	0:5350a66d5279	969	else {
hudakz	0:5350a66d5279	970	UIP_LOG("ip: packet dropped since no address assigned.");
hudakz	0:5350a66d5279	971	goto drop;
hudakz	0:5350a66d5279	972	}
hudakz	0:5350a66d5279	973	#endif /* UIP_PINGADDRCONF */
hudakz	0:5350a66d5279	974	}
hudakz	0:5350a66d5279	975	else
hudakz	0:5350a66d5279	976	{
hudakz	0:5350a66d5279	977	/* If IP broadcast support is configured, we check for a broadcast
hudakz	0:5350a66d5279	978	UDP packet, which may be destined to us. */
hudakz	0:5350a66d5279	979	#if UIP_BROADCAST
hudakz	0:5350a66d5279	980	DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum());
hudakz	0:5350a66d5279	981	if
hudakz	0:5350a66d5279	982	(
hudakz	0:5350a66d5279	983	BUF->proto == UIP_PROTO_UDP
hudakz	0:5350a66d5279	984	&& uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr) /*&&
hudakz	0:5350a66d5279	985	uip_ipchksum() == 0xffff*/
hudakz	0:5350a66d5279	986	) {
hudakz	0:5350a66d5279	987	goto udp_input;
hudakz	0:5350a66d5279	988	}
hudakz	0:5350a66d5279	989	#endif /* UIP_BROADCAST */
hudakz	0:5350a66d5279	990
hudakz	0:5350a66d5279	991	/* Check if the packet is destined for our IP address. */
hudakz	0:5350a66d5279	992
hudakz	0:5350a66d5279	993	#if !UIP_CONF_IPV6
hudakz	0:5350a66d5279	994	if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr)) {
hudakz	0:5350a66d5279	995	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	996	goto drop;
hudakz	0:5350a66d5279	997	}
hudakz	0:5350a66d5279	998
hudakz	0:5350a66d5279	999	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1000	/* For IPv6, packet reception is a little trickier as we need to
hudakz	0:5350a66d5279	1001	make sure that we listen to certain multicast addresses (all
hudakz	0:5350a66d5279	1002	hosts multicast address, and the solicited-node multicast
hudakz	0:5350a66d5279	1003	address) as well. However, we will cheat here and accept all
hudakz	0:5350a66d5279	1004	multicast packets that are sent to the ff02::/16 addresses. */
hudakz	0:5350a66d5279	1005
hudakz	0:5350a66d5279	1006	if(!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr) && BUF->destipaddr[0] != HTONS(0xff02)) {
hudakz	0:5350a66d5279	1007	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	1008	goto drop;
hudakz	0:5350a66d5279	1009	}
hudakz	0:5350a66d5279	1010	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1011	}
hudakz	0:5350a66d5279	1012
hudakz	0:5350a66d5279	1013	#if !UIP_CONF_IPV6
hudakz	0:5350a66d5279	1014	if(uip_ipchksum() != 0xffff) {
hudakz	0:5350a66d5279	1015
hudakz	0:5350a66d5279	1016	/* Compute and check the IP header
hudakz	0:5350a66d5279	1017	checksum. */
hudakz	0:5350a66d5279	1018	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	1019	UIP_STAT(++uip_stat.ip.chkerr);
hudakz	0:5350a66d5279	1020	UIP_LOG("ip: bad checksum.");
hudakz	0:5350a66d5279	1021	goto drop;
hudakz	0:5350a66d5279	1022	}
hudakz	0:5350a66d5279	1023	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1024
hudakz	0:5350a66d5279	1025	if(BUF->proto == UIP_PROTO_TCP) {
hudakz	0:5350a66d5279	1026
hudakz	0:5350a66d5279	1027	/* Check for TCP packet. If so,
hudakz	0:5350a66d5279	1028	proceed with TCP input
hudakz	0:5350a66d5279	1029	processing. */
hudakz	0:5350a66d5279	1030	goto tcp_input;
hudakz	0:5350a66d5279	1031	}
hudakz	0:5350a66d5279	1032
hudakz	0:5350a66d5279	1033	#if UIP_UDP
hudakz	0:5350a66d5279	1034	if(BUF->proto == UIP_PROTO_UDP) {
hudakz	0:5350a66d5279	1035	goto udp_input;
hudakz	0:5350a66d5279	1036	}
hudakz	0:5350a66d5279	1037	#endif /* UIP_UDP */
hudakz	0:5350a66d5279	1038
hudakz	0:5350a66d5279	1039	#if !UIP_CONF_IPV6
hudakz	0:5350a66d5279	1040	/* ICMPv4 processing code follows. */
hudakz	0:5350a66d5279	1041
hudakz	0:5350a66d5279	1042	if(BUF->proto != UIP_PROTO_ICMP) {
hudakz	0:5350a66d5279	1043
hudakz	0:5350a66d5279	1044	/* We only allow ICMP packets from
hudakz	0:5350a66d5279	1045	here. */
hudakz	0:5350a66d5279	1046	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	1047	UIP_STAT(++uip_stat.ip.protoerr);
hudakz	0:5350a66d5279	1048	UIP_LOG("ip: neither tcp nor icmp.");
hudakz	0:5350a66d5279	1049	goto drop;
hudakz	0:5350a66d5279	1050	}
hudakz	0:5350a66d5279	1051
hudakz	0:5350a66d5279	1052	#if UIP_PINGADDRCONF
hudakz	0:5350a66d5279	1053	icmp_input :
hudakz	0:5350a66d5279	1054	#endif /* UIP_PINGADDRCONF */
hudakz	0:5350a66d5279	1055
hudakz	0:5350a66d5279	1056	UIP_STAT(++uip_stat.icmp.recv);
hudakz	0:5350a66d5279	1057
hudakz	0:5350a66d5279	1058	/* ICMP echo (i.e., ping) processing. This is simple, we only change
hudakz	0:5350a66d5279	1059	the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
hudakz	0:5350a66d5279	1060	checksum before we return the packet. */
hudakz	0:5350a66d5279	1061	if(ICMPBUF->type != ICMP_ECHO) {
hudakz	0:5350a66d5279	1062	UIP_STAT(++uip_stat.icmp.drop);
hudakz	0:5350a66d5279	1063	UIP_STAT(++uip_stat.icmp.typeerr);
hudakz	0:5350a66d5279	1064	UIP_LOG("icmp: not icmp echo.");
hudakz	0:5350a66d5279	1065	goto drop;
hudakz	0:5350a66d5279	1066	}
hudakz	0:5350a66d5279	1067
hudakz	0:5350a66d5279	1068	/* If we are configured to use ping IP address assignment, we use
hudakz	0:5350a66d5279	1069	the destination IP address of this ping packet and assign it to
hudakz	0:5350a66d5279	1070	ourself. */
hudakz	0:5350a66d5279	1071	#if UIP_PINGADDRCONF
hudakz	0:5350a66d5279	1072	if((uip_hostaddr[0] \| uip_hostaddr[1]) == 0) {
hudakz	0:5350a66d5279	1073	uip_hostaddr[0] = BUF->destipaddr[0];
hudakz	0:5350a66d5279	1074	uip_hostaddr[1] = BUF->destipaddr[1];
hudakz	0:5350a66d5279	1075	}
hudakz	0:5350a66d5279	1076	#endif /* UIP_PINGADDRCONF */
hudakz	0:5350a66d5279	1077
hudakz	0:5350a66d5279	1078	ICMPBUF->type = ICMP_ECHO_REPLY;
hudakz	0:5350a66d5279	1079
hudakz	0:5350a66d5279	1080	if(ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
hudakz	0:5350a66d5279	1081	ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
hudakz	0:5350a66d5279	1082	}
hudakz	0:5350a66d5279	1083	else {
hudakz	0:5350a66d5279	1084	ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
hudakz	0:5350a66d5279	1085	}
hudakz	0:5350a66d5279	1086
hudakz	0:5350a66d5279	1087	/* Swap IP addresses. */
hudakz	0:5350a66d5279	1088	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
hudakz	0:5350a66d5279	1089	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	0:5350a66d5279	1090
hudakz	0:5350a66d5279	1091	UIP_STAT(++uip_stat.icmp.sent);
hudakz	0:5350a66d5279	1092	goto send;
hudakz	0:5350a66d5279	1093
hudakz	0:5350a66d5279	1094	/* End of IPv4 input header processing code. */
hudakz	0:5350a66d5279	1095	#else /* !UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1096	/* This is IPv6 ICMPv6 processing code. */
hudakz	0:5350a66d5279	1097
hudakz	0:5350a66d5279	1098	DEBUG_PRINTF("icmp6_input: length %d\n", uip_len);
hudakz	0:5350a66d5279	1099
hudakz	0:5350a66d5279	1100	if(BUF->proto != UIP_PROTO_ICMP6) {
hudakz	0:5350a66d5279	1101
hudakz	0:5350a66d5279	1102	/* We only allow ICMPv6 packets from
hudakz	0:5350a66d5279	1103	here. */
hudakz	0:5350a66d5279	1104	UIP_STAT(++uip_stat.ip.drop);
hudakz	0:5350a66d5279	1105	UIP_STAT(++uip_stat.ip.protoerr);
hudakz	0:5350a66d5279	1106	UIP_LOG("ip: neither tcp nor icmp6.");
hudakz	0:5350a66d5279	1107	goto drop;
hudakz	0:5350a66d5279	1108	}
hudakz	0:5350a66d5279	1109
hudakz	0:5350a66d5279	1110	UIP_STAT(++uip_stat.icmp.recv);
hudakz	0:5350a66d5279	1111
hudakz	0:5350a66d5279	1112	/* If we get a neighbor solicitation for our address we should send
hudakz	0:5350a66d5279	1113	a neighbor advertisement message back. */
hudakz	0:5350a66d5279	1114	if(ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) {
hudakz	0:5350a66d5279	1115	if(uip_ipaddr_cmp(ICMPBUF->icmp6data, uip_hostaddr)) {
hudakz	0:5350a66d5279	1116	if(ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) {
hudakz	0:5350a66d5279	1117
hudakz	0:5350a66d5279	1118	/* Save the sender's address in our neighbor list. */
hudakz	0:5350a66d5279	1119	uip_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
hudakz	0:5350a66d5279	1120	}
hudakz	0:5350a66d5279	1121
hudakz	0:5350a66d5279	1122	/* We should now send a neighbor advertisement back to where the
hudakz	0:5350a66d5279	1123	neighbor solicication came from. */
hudakz	0:5350a66d5279	1124	ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
hudakz	0:5350a66d5279	1125	ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
hudakz	0:5350a66d5279	1126
hudakz	0:5350a66d5279	1127	ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
hudakz	0:5350a66d5279	1128
hudakz	0:5350a66d5279	1129	uip_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
hudakz	0:5350a66d5279	1130	uip_ipaddr_copy(ICMPBUF->srcipaddr, uip_hostaddr);
hudakz	0:5350a66d5279	1131	ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
hudakz	0:5350a66d5279	1132	ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */
hudakz	0:5350a66d5279	1133	memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr));
hudakz	0:5350a66d5279	1134	ICMPBUF->icmpchksum = 0;
hudakz	0:5350a66d5279	1135	ICMPBUF->icmpchksum = ~uip_icmp6chksum();
hudakz	0:5350a66d5279	1136	goto send;
hudakz	0:5350a66d5279	1137	}
hudakz	0:5350a66d5279	1138
hudakz	0:5350a66d5279	1139	goto drop;
hudakz	0:5350a66d5279	1140	}
hudakz	0:5350a66d5279	1141	else
hudakz	0:5350a66d5279	1142	if(ICMPBUF->type == ICMP6_ECHO) {
hudakz	0:5350a66d5279	1143
hudakz	0:5350a66d5279	1144	/* ICMP echo (i.e., ping) processing. This is simple, we only
hudakz	0:5350a66d5279	1145	change the ICMP type from ECHO to ECHO_REPLY and update the
hudakz	0:5350a66d5279	1146	ICMP checksum before we return the packet. */
hudakz	0:5350a66d5279	1147	ICMPBUF->type = ICMP6_ECHO_REPLY;
hudakz	0:5350a66d5279	1148
hudakz	0:5350a66d5279	1149	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
hudakz	0:5350a66d5279	1150	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	0:5350a66d5279	1151	ICMPBUF->icmpchksum = 0;
hudakz	0:5350a66d5279	1152	ICMPBUF->icmpchksum = ~uip_icmp6chksum();
hudakz	0:5350a66d5279	1153
hudakz	0:5350a66d5279	1154	UIP_STAT(++uip_stat.icmp.sent);
hudakz	0:5350a66d5279	1155	goto send;
hudakz	0:5350a66d5279	1156	}
hudakz	0:5350a66d5279	1157	else {
hudakz	0:5350a66d5279	1158	DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type);
hudakz	0:5350a66d5279	1159	UIP_STAT(++uip_stat.icmp.drop);
hudakz	0:5350a66d5279	1160	UIP_STAT(++uip_stat.icmp.typeerr);
hudakz	0:5350a66d5279	1161	UIP_LOG("icmp: unknown ICMP message.");
hudakz	0:5350a66d5279	1162	goto drop;
hudakz	0:5350a66d5279	1163	}
hudakz	0:5350a66d5279	1164
hudakz	0:5350a66d5279	1165	/* End of IPv6 ICMP processing. */
hudakz	0:5350a66d5279	1166	#endif /* !UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1167
hudakz	0:5350a66d5279	1168	#if UIP_UDP
hudakz	0:5350a66d5279	1169	/* UDP input processing. */
hudakz	0:5350a66d5279	1170
hudakz	0:5350a66d5279	1171	udp_input :
hudakz	0:5350a66d5279	1172	/* UDP processing is really just a hack. We don't do anything to the
hudakz	0:5350a66d5279	1173	UDP/IP headers, but let the UDP application do all the hard
hudakz	0:5350a66d5279	1174	work. If the application sets uip_slen, it has a packet to
hudakz	0:5350a66d5279	1175	send. */
hudakz	0:5350a66d5279	1176	#if UIP_UDP_CHECKSUMS
hudakz	0:5350a66d5279	1177	uip_len = uip_len - UIP_IPUDPH_LEN;
hudakz	0:5350a66d5279	1178	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
hudakz	0:5350a66d5279	1179	if(UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) {
hudakz	0:5350a66d5279	1180	UIP_STAT(++uip_stat.udp.drop);
hudakz	0:5350a66d5279	1181	UIP_STAT(++uip_stat.udp.chkerr);
hudakz	0:5350a66d5279	1182	UIP_LOG("udp: bad checksum.");
hudakz	0:5350a66d5279	1183	goto drop;
hudakz	0:5350a66d5279	1184	}
hudakz	0:5350a66d5279	1185
hudakz	0:5350a66d5279	1186	#else /* UIP_UDP_CHECKSUMS */
hudakz	0:5350a66d5279	1187	uip_len = uip_len - UIP_IPUDPH_LEN;
hudakz	0:5350a66d5279	1188	#endif /* UIP_UDP_CHECKSUMS */
hudakz	0:5350a66d5279	1189
hudakz	0:5350a66d5279	1190	/* Demultiplex this UDP packet between the UDP "connections". */
hudakz	0:5350a66d5279	1191
hudakz	0:5350a66d5279	1192	for(uip_udp_conn = &uip_udp_conns[0]; uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS]; ++uip_udp_conn) {
hudakz	0:5350a66d5279	1193
hudakz	0:5350a66d5279	1194	/* If the local UDP port is non-zero, the connection is considered
hudakz	0:5350a66d5279	1195	to be used. If so, the local port number is checked against the
hudakz	0:5350a66d5279	1196	destination port number in the received packet. If the two port
hudakz	0:5350a66d5279	1197	numbers match, the remote port number is checked if the
hudakz	0:5350a66d5279	1198	connection is bound to a remote port. Finally, if the
hudakz	0:5350a66d5279	1199	connection is bound to a remote IP address, the source IP
hudakz	0:5350a66d5279	1200	address of the packet is checked. */
hudakz	0:5350a66d5279	1201	if
hudakz	0:5350a66d5279	1202	(
hudakz	0:5350a66d5279	1203	uip_udp_conn->lport != 0
hudakz	0:5350a66d5279	1204	&& UDPBUF->destport == uip_udp_conn->lport
hudakz	0:5350a66d5279	1205	&& (uip_udp_conn->rport == 0 \|\| UDPBUF->srcport == uip_udp_conn->rport)
hudakz	0:5350a66d5279	1206	&& (
hudakz	0:5350a66d5279	1207	uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_zeroes_addr)
hudakz	0:5350a66d5279	1208	\|\| uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_ones_addr)
hudakz	0:5350a66d5279	1209	\|\| uip_ipaddr_cmp(BUF->srcipaddr, uip_udp_conn->ripaddr)
hudakz	0:5350a66d5279	1210	)
hudakz	0:5350a66d5279	1211	) {
hudakz	0:5350a66d5279	1212	goto udp_found;
hudakz	0:5350a66d5279	1213	}
hudakz	0:5350a66d5279	1214	}
hudakz	0:5350a66d5279	1215
hudakz	0:5350a66d5279	1216	UIP_LOG("udp: no matching connection found");
hudakz	0:5350a66d5279	1217	goto drop;
hudakz	0:5350a66d5279	1218
hudakz	0:5350a66d5279	1219	udp_found:
hudakz	0:5350a66d5279	1220	uip_conn = NULL;
hudakz	0:5350a66d5279	1221	uip_flags = UIP_NEWDATA;
hudakz	0:5350a66d5279	1222	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
hudakz	0:5350a66d5279	1223	uip_slen = 0;
hudakz	0:5350a66d5279	1224	UIP_UDP_APPCALL();
hudakz	0:5350a66d5279	1225	udp_send:
hudakz	0:5350a66d5279	1226	if(uip_slen == 0) {
hudakz	0:5350a66d5279	1227	goto drop;
hudakz	0:5350a66d5279	1228	}
hudakz	0:5350a66d5279	1229
hudakz	0:5350a66d5279	1230	uip_len = uip_slen + UIP_IPUDPH_LEN;
hudakz	0:5350a66d5279	1231
hudakz	0:5350a66d5279	1232	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	1233	/* For IPv6, the IP length field does not include the IPv6 IP header
hudakz	0:5350a66d5279	1234	length. */
hudakz	0:5350a66d5279	1235
hudakz	0:5350a66d5279	1236	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
hudakz	0:5350a66d5279	1237	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
hudakz	0:5350a66d5279	1238	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1239	BUF->len[0] = (uip_len >> 8);
hudakz	0:5350a66d5279	1240	BUF->len[1] = (uip_len & 0xff);
hudakz	0:5350a66d5279	1241	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1242
hudakz	0:5350a66d5279	1243	BUF->ttl = uip_udp_conn->ttl;
hudakz	0:5350a66d5279	1244	BUF->proto = UIP_PROTO_UDP;
hudakz	0:5350a66d5279	1245
hudakz	0:5350a66d5279	1246	UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN);
hudakz	0:5350a66d5279	1247	UDPBUF->udpchksum = 0;
hudakz	0:5350a66d5279	1248
hudakz	0:5350a66d5279	1249	BUF->srcport = uip_udp_conn->lport;
hudakz	0:5350a66d5279	1250	BUF->destport = uip_udp_conn->rport;
hudakz	0:5350a66d5279	1251
hudakz	0:5350a66d5279	1252	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	0:5350a66d5279	1253	uip_ipaddr_copy(BUF->destipaddr, uip_udp_conn->ripaddr);
hudakz	0:5350a66d5279	1254
hudakz	0:5350a66d5279	1255	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN];
hudakz	0:5350a66d5279	1256
hudakz	0:5350a66d5279	1257	#if UIP_UDP_CHECKSUMS
hudakz	0:5350a66d5279	1258	/* Calculate UDP checksum. */
hudakz	0:5350a66d5279	1259
hudakz	0:5350a66d5279	1260	UDPBUF->udpchksum = ~(uip_udpchksum());
hudakz	0:5350a66d5279	1261	if(UDPBUF->udpchksum == 0) {
hudakz	0:5350a66d5279	1262	UDPBUF->udpchksum = 0xffff;
hudakz	0:5350a66d5279	1263	}
hudakz	0:5350a66d5279	1264	#endif /* UIP_UDP_CHECKSUMS */
hudakz	0:5350a66d5279	1265
hudakz	0:5350a66d5279	1266	goto ip_send_nolen;
hudakz	0:5350a66d5279	1267	#endif /* UIP_UDP */
hudakz	0:5350a66d5279	1268
hudakz	0:5350a66d5279	1269	/* TCP input processing. */
hudakz	0:5350a66d5279	1270
hudakz	0:5350a66d5279	1271	tcp_input : UIP_STAT(++uip_stat.tcp.recv);
hudakz	0:5350a66d5279	1272
hudakz	0:5350a66d5279	1273	/* Start of TCP input header processing code. */
hudakz	0:5350a66d5279	1274	if(uip_tcpchksum() != 0xffff) {
hudakz	0:5350a66d5279	1275
hudakz	0:5350a66d5279	1276	/* Compute and check the TCP
hudakz	0:5350a66d5279	1277	checksum. */
hudakz	0:5350a66d5279	1278	UIP_STAT(++uip_stat.tcp.drop);
hudakz	0:5350a66d5279	1279	UIP_STAT(++uip_stat.tcp.chkerr);
hudakz	0:5350a66d5279	1280	UIP_LOG("tcp: bad checksum.");
hudakz	0:5350a66d5279	1281	goto drop;
hudakz	0:5350a66d5279	1282	}
hudakz	0:5350a66d5279	1283
hudakz	0:5350a66d5279	1284	/* Demultiplex this segment. */
hudakz	0:5350a66d5279	1285	/* First check any active connections. */
hudakz	0:5350a66d5279	1286	for(uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1]; ++uip_connr) {
hudakz	0:5350a66d5279	1287	if
hudakz	0:5350a66d5279	1288	(
hudakz	0:5350a66d5279	1289	uip_connr->tcpstateflags != UIP_CLOSED
hudakz	0:5350a66d5279	1290	&& BUF->destport == uip_connr->lport
hudakz	0:5350a66d5279	1291	&& BUF->srcport == uip_connr->rport
hudakz	0:5350a66d5279	1292	&& uip_ipaddr_cmp(BUF->srcipaddr, uip_connr->ripaddr)
hudakz	0:5350a66d5279	1293	) {
hudakz	0:5350a66d5279	1294	goto found;
hudakz	0:5350a66d5279	1295	}
hudakz	0:5350a66d5279	1296	}
hudakz	0:5350a66d5279	1297
hudakz	0:5350a66d5279	1298	/* If we didn't find and active connection that expected the packet,
hudakz	0:5350a66d5279	1299	either this packet is an old duplicate, or this is a SYN packet
hudakz	0:5350a66d5279	1300	destined for a connection in LISTEN. If the SYN flag isn't set,
hudakz	0:5350a66d5279	1301	it is an old packet and we send a RST. */
hudakz	0:5350a66d5279	1302	if((BUF->flags & TCP_CTL) != TCP_SYN) {
hudakz	0:5350a66d5279	1303	goto reset;
hudakz	0:5350a66d5279	1304	}
hudakz	0:5350a66d5279	1305
hudakz	0:5350a66d5279	1306	tmp16 = BUF->destport;
hudakz	0:5350a66d5279	1307
hudakz	0:5350a66d5279	1308	/* Next, check listening connections. */
hudakz	0:5350a66d5279	1309	for(c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	0:5350a66d5279	1310	if(tmp16 == uip_listenports[c])
hudakz	0:5350a66d5279	1311	goto found_listen;
hudakz	0:5350a66d5279	1312	}
hudakz	0:5350a66d5279	1313
hudakz	0:5350a66d5279	1314	/* No matching connection found, so we send a RST packet. */
hudakz	0:5350a66d5279	1315	UIP_STAT(++uip_stat.tcp.synrst);
hudakz	0:5350a66d5279	1316	reset:
hudakz	0:5350a66d5279	1317	/* We do not send resets in response to resets. */
hudakz	0:5350a66d5279	1318	if(BUF->flags & TCP_RST) {
hudakz	0:5350a66d5279	1319	goto drop;
hudakz	0:5350a66d5279	1320	}
hudakz	0:5350a66d5279	1321
hudakz	0:5350a66d5279	1322	UIP_STAT(++uip_stat.tcp.rst);
hudakz	0:5350a66d5279	1323
hudakz	0:5350a66d5279	1324	BUF->flags = TCP_RST \| TCP_ACK;
hudakz	0:5350a66d5279	1325	uip_len = UIP_IPTCPH_LEN;
hudakz	0:5350a66d5279	1326	BUF->tcpoffset = 5 << 4;
hudakz	0:5350a66d5279	1327
hudakz	0:5350a66d5279	1328	/* Flip the seqno and ackno fields in the TCP header. */
hudakz	0:5350a66d5279	1329	c = BUF->seqno[3];
hudakz	0:5350a66d5279	1330	BUF->seqno[3] = BUF->ackno[3];
hudakz	0:5350a66d5279	1331	BUF->ackno[3] = c;
hudakz	0:5350a66d5279	1332
hudakz	0:5350a66d5279	1333	c = BUF->seqno[2];
hudakz	0:5350a66d5279	1334	BUF->seqno[2] = BUF->ackno[2];
hudakz	0:5350a66d5279	1335	BUF->ackno[2] = c;
hudakz	0:5350a66d5279	1336
hudakz	0:5350a66d5279	1337	c = BUF->seqno[1];
hudakz	0:5350a66d5279	1338	BUF->seqno[1] = BUF->ackno[1];
hudakz	0:5350a66d5279	1339	BUF->ackno[1] = c;
hudakz	0:5350a66d5279	1340
hudakz	0:5350a66d5279	1341	c = BUF->seqno[0];
hudakz	0:5350a66d5279	1342	BUF->seqno[0] = BUF->ackno[0];
hudakz	0:5350a66d5279	1343	BUF->ackno[0] = c;
hudakz	0:5350a66d5279	1344
hudakz	0:5350a66d5279	1345	/* We also have to increase the sequence number we are
hudakz	0:5350a66d5279	1346	acknowledging. If the least significant byte overflowed, we need
hudakz	0:5350a66d5279	1347	to propagate the carry to the other bytes as well. */
hudakz	0:5350a66d5279	1348	if(++BUF->ackno[3] == 0) {
hudakz	0:5350a66d5279	1349	if(++BUF->ackno[2] == 0) {
hudakz	0:5350a66d5279	1350	if(++BUF->ackno[1] == 0) {
hudakz	0:5350a66d5279	1351	++BUF->ackno[0];
hudakz	0:5350a66d5279	1352	}
hudakz	0:5350a66d5279	1353	}
hudakz	0:5350a66d5279	1354	}
hudakz	0:5350a66d5279	1355
hudakz	0:5350a66d5279	1356	/* Swap port numbers. */
hudakz	0:5350a66d5279	1357	tmp16 = BUF->srcport;
hudakz	0:5350a66d5279	1358	BUF->srcport = BUF->destport;
hudakz	0:5350a66d5279	1359	BUF->destport = tmp16;
hudakz	0:5350a66d5279	1360
hudakz	0:5350a66d5279	1361	/* Swap IP addresses. */
hudakz	0:5350a66d5279	1362	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
hudakz	0:5350a66d5279	1363	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	0:5350a66d5279	1364
hudakz	0:5350a66d5279	1365	/* And send out the RST packet! */
hudakz	0:5350a66d5279	1366	goto tcp_send_noconn;
hudakz	0:5350a66d5279	1367
hudakz	0:5350a66d5279	1368	/* This label will be jumped to if we matched the incoming packet
hudakz	0:5350a66d5279	1369	with a connection in LISTEN. In that case, we should create a new
hudakz	0:5350a66d5279	1370	connection and send a SYNACK in return. */
hudakz	0:5350a66d5279	1371	found_listen:
hudakz	0:5350a66d5279	1372	/* First we check if there are any connections avaliable. Unused
hudakz	0:5350a66d5279	1373	connections are kept in the same table as used connections, but
hudakz	0:5350a66d5279	1374	unused ones have the tcpstate set to CLOSED. Also, connections in
hudakz	0:5350a66d5279	1375	TIME_WAIT are kept track of and we'll use the oldest one if no
hudakz	0:5350a66d5279	1376	CLOSED connections are found. Thanks to Eddie C. Dost for a very
hudakz	0:5350a66d5279	1377	nice algorithm for the TIME_WAIT search. */
hudakz	0:5350a66d5279	1378	uip_connr = 0;
hudakz	0:5350a66d5279	1379	for(c = 0; c < UIP_CONNS; ++c) {
hudakz	0:5350a66d5279	1380	if(uip_conns[c].tcpstateflags == UIP_CLOSED) {
hudakz	0:5350a66d5279	1381	uip_connr = &uip_conns[c];
hudakz	0:5350a66d5279	1382	break;
hudakz	0:5350a66d5279	1383	}
hudakz	0:5350a66d5279	1384
hudakz	0:5350a66d5279	1385	if(uip_conns[c].tcpstateflags == UIP_TIME_WAIT) {
hudakz	0:5350a66d5279	1386	if(uip_connr == 0 \|\| uip_conns[c].timer > uip_connr->timer) {
hudakz	0:5350a66d5279	1387	uip_connr = &uip_conns[c];
hudakz	0:5350a66d5279	1388	}
hudakz	0:5350a66d5279	1389	}
hudakz	0:5350a66d5279	1390	}
hudakz	0:5350a66d5279	1391
hudakz	0:5350a66d5279	1392	if(uip_connr == 0) {
hudakz	0:5350a66d5279	1393
hudakz	0:5350a66d5279	1394	/* All connections are used already, we drop packet and hope that
hudakz	0:5350a66d5279	1395	the remote end will retransmit the packet at a time when we
hudakz	0:5350a66d5279	1396	have more spare connections. */
hudakz	0:5350a66d5279	1397	UIP_STAT(++uip_stat.tcp.syndrop);
hudakz	0:5350a66d5279	1398	UIP_LOG("tcp: found no unused connections.");
hudakz	0:5350a66d5279	1399	goto drop;
hudakz	0:5350a66d5279	1400	}
hudakz	0:5350a66d5279	1401
hudakz	0:5350a66d5279	1402	uip_conn = uip_connr;
hudakz	0:5350a66d5279	1403
hudakz	0:5350a66d5279	1404	/* Fill in the necessary fields for the new connection. */
hudakz	0:5350a66d5279	1405	uip_connr->rto = uip_connr->timer = UIP_RTO;
hudakz	0:5350a66d5279	1406	uip_connr->sa = 0;
hudakz	0:5350a66d5279	1407	uip_connr->sv = 4;
hudakz	0:5350a66d5279	1408	uip_connr->nrtx = 0;
hudakz	0:5350a66d5279	1409	uip_connr->lport = BUF->destport;
hudakz	0:5350a66d5279	1410	uip_connr->rport = BUF->srcport;
hudakz	0:5350a66d5279	1411	uip_ipaddr_copy(uip_connr->ripaddr, BUF->srcipaddr);
hudakz	0:5350a66d5279	1412	uip_connr->tcpstateflags = UIP_SYN_RCVD;
hudakz	0:5350a66d5279	1413
hudakz	0:5350a66d5279	1414	uip_connr->snd_nxt[0] = iss[0];
hudakz	0:5350a66d5279	1415	uip_connr->snd_nxt[1] = iss[1];
hudakz	0:5350a66d5279	1416	uip_connr->snd_nxt[2] = iss[2];
hudakz	0:5350a66d5279	1417	uip_connr->snd_nxt[3] = iss[3];
hudakz	0:5350a66d5279	1418	uip_connr->len = 1;
hudakz	0:5350a66d5279	1419
hudakz	0:5350a66d5279	1420	/* rcv_nxt should be the seqno from the incoming packet + 1. */
hudakz	0:5350a66d5279	1421	uip_connr->rcv_nxt[3] = BUF->seqno[3];
hudakz	0:5350a66d5279	1422	uip_connr->rcv_nxt[2] = BUF->seqno[2];
hudakz	0:5350a66d5279	1423	uip_connr->rcv_nxt[1] = BUF->seqno[1];
hudakz	0:5350a66d5279	1424	uip_connr->rcv_nxt[0] = BUF->seqno[0];
hudakz	0:5350a66d5279	1425	uip_add_rcv_nxt(1);
hudakz	0:5350a66d5279	1426
hudakz	0:5350a66d5279	1427	/* Parse the TCP MSS option, if present. */
hudakz	0:5350a66d5279	1428	if((BUF->tcpoffset & 0xf0) > 0x50) {
hudakz	0:5350a66d5279	1429	for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2;) {
hudakz	0:5350a66d5279	1430	opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
hudakz	0:5350a66d5279	1431	if(opt == TCP_OPT_END) {
hudakz	0:5350a66d5279	1432
hudakz	0:5350a66d5279	1433	/* End of options. */
hudakz	0:5350a66d5279	1434	break;
hudakz	0:5350a66d5279	1435	}
hudakz	0:5350a66d5279	1436	else
hudakz	0:5350a66d5279	1437	if(opt == TCP_OPT_NOOP) {
hudakz	0:5350a66d5279	1438	++c;
hudakz	0:5350a66d5279	1439
hudakz	0:5350a66d5279	1440	/* NOP option. */
hudakz	0:5350a66d5279	1441	}
hudakz	0:5350a66d5279	1442	else
hudakz	0:5350a66d5279	1443	if(opt == TCP_OPT_MSS && uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
hudakz	0:5350a66d5279	1444
hudakz	0:5350a66d5279	1445	/* An MSS option with the right option length. */
hudakz	0:5350a66d5279	1446	tmp16 = ((u16_t) uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) \| (u16_t) uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + 3 + c];
hudakz	0:5350a66d5279	1447	uip_connr->initialmss = uip_connr->mss = tmp16 > UIP_TCP_MSS ? UIP_TCP_MSS : tmp16;
hudakz	0:5350a66d5279	1448
hudakz	0:5350a66d5279	1449	/* And we are done processing options. */
hudakz	0:5350a66d5279	1450	break;
hudakz	0:5350a66d5279	1451	}
hudakz	0:5350a66d5279	1452	else {
hudakz	0:5350a66d5279	1453
hudakz	0:5350a66d5279	1454	/* All other options have a length field, so that we easily
hudakz	0:5350a66d5279	1455	can skip past them. */
hudakz	0:5350a66d5279	1456	if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
hudakz	0:5350a66d5279	1457
hudakz	0:5350a66d5279	1458	/* If the length field is zero, the options are malformed
hudakz	0:5350a66d5279	1459	and we don't process them further. */
hudakz	0:5350a66d5279	1460	break;
hudakz	0:5350a66d5279	1461	}
hudakz	0:5350a66d5279	1462
hudakz	0:5350a66d5279	1463	c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
hudakz	0:5350a66d5279	1464	}
hudakz	0:5350a66d5279	1465	}
hudakz	0:5350a66d5279	1466	}
hudakz	0:5350a66d5279	1467
hudakz	0:5350a66d5279	1468	/* Our response will be a SYNACK. */
hudakz	0:5350a66d5279	1469	#if UIP_ACTIVE_OPEN
hudakz	0:5350a66d5279	1470	tcp_send_synack : BUF->flags = TCP_ACK;
hudakz	0:5350a66d5279	1471
hudakz	0:5350a66d5279	1472	tcp_send_syn:
hudakz	0:5350a66d5279	1473	BUF->flags \|= TCP_SYN;
hudakz	0:5350a66d5279	1474	#else /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	1475	tcp_send_synack : BUF->flags = TCP_SYN \| TCP_ACK;
hudakz	0:5350a66d5279	1476	#endif /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	1477
hudakz	0:5350a66d5279	1478	/* We send out the TCP Maximum Segment Size option with our
hudakz	0:5350a66d5279	1479	SYNACK. */
hudakz	0:5350a66d5279	1480
hudakz	0:5350a66d5279	1481	BUF->optdata[0] = TCP_OPT_MSS;
hudakz	0:5350a66d5279	1482	BUF->optdata[1] = TCP_OPT_MSS_LEN;
hudakz	0:5350a66d5279	1483	BUF->optdata[2] = (UIP_TCP_MSS) / 256;
hudakz	0:5350a66d5279	1484	BUF->optdata[3] = (UIP_TCP_MSS) & 255;
hudakz	0:5350a66d5279	1485	uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
hudakz	0:5350a66d5279	1486	BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
hudakz	0:5350a66d5279	1487	goto tcp_send;
hudakz	0:5350a66d5279	1488
hudakz	0:5350a66d5279	1489	/* This label will be jumped to if we found an active connection. */
hudakz	0:5350a66d5279	1490	found:
hudakz	0:5350a66d5279	1491	uip_conn = uip_connr;
hudakz	0:5350a66d5279	1492	uip_flags = 0;
hudakz	0:5350a66d5279	1493
hudakz	0:5350a66d5279	1494	/* We do a very naive form of TCP reset processing; we just accept
hudakz	0:5350a66d5279	1495	any RST and kill our connection. We should in fact check if the
hudakz	0:5350a66d5279	1496	sequence number of this reset is wihtin our advertised window
hudakz	0:5350a66d5279	1497	before we accept the reset. */
hudakz	0:5350a66d5279	1498	if(BUF->flags & TCP_RST) {
hudakz	0:5350a66d5279	1499	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	1500	UIP_LOG("tcp: got reset, aborting connection.");
hudakz	0:5350a66d5279	1501	uip_flags = UIP_ABORT;
hudakz	0:5350a66d5279	1502	UIP_APPCALL();
hudakz	0:5350a66d5279	1503	goto drop;
hudakz	0:5350a66d5279	1504	}
hudakz	0:5350a66d5279	1505
hudakz	0:5350a66d5279	1506	/* Calculated the length of the data, if the application has sent
hudakz	0:5350a66d5279	1507	any data to us. */
hudakz	0:5350a66d5279	1508	c = (BUF->tcpoffset >> 4) << 2;
hudakz	0:5350a66d5279	1509
hudakz	0:5350a66d5279	1510	/* uip_len will contain the length of the actual TCP data. This is
hudakz	0:5350a66d5279	1511	calculated by subtracing the length of the TCP header (in
hudakz	0:5350a66d5279	1512	c) and the length of the IP header (20 bytes). */
hudakz	0:5350a66d5279	1513	uip_len = uip_len - c - UIP_IPH_LEN;
hudakz	0:5350a66d5279	1514
hudakz	0:5350a66d5279	1515	/* First, check if the sequence number of the incoming packet is
hudakz	0:5350a66d5279	1516	what we're expecting next. If not, we send out an ACK with the
hudakz	0:5350a66d5279	1517	correct numbers in. */
hudakz	0:5350a66d5279	1518	if(!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT) && ((BUF->flags & TCP_CTL) == (TCP_SYN \| TCP_ACK)))) {
hudakz	0:5350a66d5279	1519	if
hudakz	0:5350a66d5279	1520	(
hudakz	0:5350a66d5279	1521	(uip_len > 0 \|\| ((BUF->flags & (TCP_SYN \| TCP_FIN)) != 0))
hudakz	0:5350a66d5279	1522	&& (
hudakz	0:5350a66d5279	1523	BUF->seqno[0] != uip_connr->rcv_nxt[0]
hudakz	0:5350a66d5279	1524	\|\| BUF->seqno[1] != uip_connr->rcv_nxt[1]
hudakz	0:5350a66d5279	1525	\|\| BUF->seqno[2] != uip_connr->rcv_nxt[2]
hudakz	0:5350a66d5279	1526	\|\| BUF->seqno[3] != uip_connr->rcv_nxt[3]
hudakz	0:5350a66d5279	1527	)
hudakz	0:5350a66d5279	1528	) {
hudakz	0:5350a66d5279	1529	goto tcp_send_ack;
hudakz	0:5350a66d5279	1530	}
hudakz	0:5350a66d5279	1531	}
hudakz	0:5350a66d5279	1532
hudakz	0:5350a66d5279	1533	/* Next, check if the incoming segment acknowledges any outstanding
hudakz	0:5350a66d5279	1534	data. If so, we update the sequence number, reset the length of
hudakz	0:5350a66d5279	1535	the outstanding data, calculate RTT estimations, and reset the
hudakz	0:5350a66d5279	1536	retransmission timer. */
hudakz	0:5350a66d5279	1537	if((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
hudakz	0:5350a66d5279	1538	uip_add32(uip_connr->snd_nxt, uip_connr->len);
hudakz	0:5350a66d5279	1539
hudakz	0:5350a66d5279	1540	if
hudakz	0:5350a66d5279	1541	(
hudakz	0:5350a66d5279	1542	BUF->ackno[0] == uip_acc32[0]
hudakz	0:5350a66d5279	1543	&& BUF->ackno[1] == uip_acc32[1]
hudakz	0:5350a66d5279	1544	&& BUF->ackno[2] == uip_acc32[2]
hudakz	0:5350a66d5279	1545	&& BUF->ackno[3] == uip_acc32[3]
hudakz	0:5350a66d5279	1546	) {
hudakz	0:5350a66d5279	1547
hudakz	0:5350a66d5279	1548	/* Update sequence number. */
hudakz	0:5350a66d5279	1549	uip_connr->snd_nxt[0] = uip_acc32[0];
hudakz	0:5350a66d5279	1550	uip_connr->snd_nxt[1] = uip_acc32[1];
hudakz	0:5350a66d5279	1551	uip_connr->snd_nxt[2] = uip_acc32[2];
hudakz	0:5350a66d5279	1552	uip_connr->snd_nxt[3] = uip_acc32[3];
hudakz	0:5350a66d5279	1553
hudakz	0:5350a66d5279	1554	/* Do RTT estimation, unless we have done retransmissions. */
hudakz	0:5350a66d5279	1555	if(uip_connr->nrtx == 0) {
hudakz	0:5350a66d5279	1556	signed char m;
hudakz	0:5350a66d5279	1557	m = uip_connr->rto - uip_connr->timer;
hudakz	0:5350a66d5279	1558
hudakz	0:5350a66d5279	1559	/* This is taken directly from VJs original code in his paper */
hudakz	0:5350a66d5279	1560	m = m - (uip_connr->sa >> 3);
hudakz	0:5350a66d5279	1561	uip_connr->sa += m;
hudakz	0:5350a66d5279	1562	if(m < 0) {
hudakz	0:5350a66d5279	1563	m = -m;
hudakz	0:5350a66d5279	1564	}
hudakz	0:5350a66d5279	1565
hudakz	0:5350a66d5279	1566	m = m - (uip_connr->sv >> 2);
hudakz	0:5350a66d5279	1567	uip_connr->sv += m;
hudakz	0:5350a66d5279	1568	uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
hudakz	0:5350a66d5279	1569	}
hudakz	0:5350a66d5279	1570
hudakz	0:5350a66d5279	1571	/* Set the acknowledged flag. */
hudakz	0:5350a66d5279	1572	uip_flags = UIP_ACKDATA;
hudakz	0:5350a66d5279	1573
hudakz	0:5350a66d5279	1574	/* Reset the retransmission timer. */
hudakz	0:5350a66d5279	1575	uip_connr->timer = uip_connr->rto;
hudakz	0:5350a66d5279	1576
hudakz	0:5350a66d5279	1577	/* Reset length of outstanding data. */
hudakz	0:5350a66d5279	1578	uip_connr->len = 0;
hudakz	0:5350a66d5279	1579	}
hudakz	0:5350a66d5279	1580	}
hudakz	0:5350a66d5279	1581
hudakz	0:5350a66d5279	1582	/* Do different things depending on in what state the connection is. */
hudakz	0:5350a66d5279	1583	switch(uip_connr->tcpstateflags & UIP_TS_MASK) {
hudakz	0:5350a66d5279	1584	/* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
hudakz	0:5350a66d5279	1585	implemented, since we force the application to close when the
hudakz	0:5350a66d5279	1586	peer sends a FIN (hence the application goes directly from
hudakz	0:5350a66d5279	1587	ESTABLISHED to LAST_ACK). */
hudakz	0:5350a66d5279	1588	case UIP_SYN_RCVD:
hudakz	0:5350a66d5279	1589	/* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
hudakz	0:5350a66d5279	1590	we are waiting for an ACK that acknowledges the data we sent
hudakz	0:5350a66d5279	1591	out the last time. Therefore, we want to have the UIP_ACKDATA
hudakz	0:5350a66d5279	1592	flag set. If so, we enter the ESTABLISHED state. */
hudakz	0:5350a66d5279	1593	if(uip_flags & UIP_ACKDATA) {
hudakz	0:5350a66d5279	1594	uip_connr->tcpstateflags = UIP_ESTABLISHED;
hudakz	0:5350a66d5279	1595	uip_flags = UIP_CONNECTED;
hudakz	0:5350a66d5279	1596	uip_connr->len = 0;
hudakz	0:5350a66d5279	1597	if(uip_len > 0) {
hudakz	0:5350a66d5279	1598	uip_flags \|= UIP_NEWDATA;
hudakz	0:5350a66d5279	1599	uip_add_rcv_nxt(uip_len);
hudakz	0:5350a66d5279	1600	}
hudakz	0:5350a66d5279	1601
hudakz	0:5350a66d5279	1602	uip_slen = 0;
hudakz	0:5350a66d5279	1603	UIP_APPCALL();
hudakz	0:5350a66d5279	1604	goto appsend;
hudakz	0:5350a66d5279	1605	}
hudakz	0:5350a66d5279	1606
hudakz	0:5350a66d5279	1607	goto drop;
hudakz	0:5350a66d5279	1608	#if UIP_ACTIVE_OPEN
hudakz	0:5350a66d5279	1609
hudakz	0:5350a66d5279	1610	case UIP_SYN_SENT:
hudakz	0:5350a66d5279	1611	/* In SYN_SENT, we wait for a SYNACK that is sent in response to
hudakz	0:5350a66d5279	1612	our SYN. The rcv_nxt is set to sequence number in the SYNACK
hudakz	0:5350a66d5279	1613	plus one, and we send an ACK. We move into the ESTABLISHED
hudakz	0:5350a66d5279	1614	state. */
hudakz	0:5350a66d5279	1615	if((uip_flags & UIP_ACKDATA) && (BUF->flags & TCP_CTL) == (TCP_SYN \| TCP_ACK)) {
hudakz	0:5350a66d5279	1616
hudakz	0:5350a66d5279	1617	/* Parse the TCP MSS option, if present. */
hudakz	0:5350a66d5279	1618	if((BUF->tcpoffset & 0xf0) > 0x50) {
hudakz	0:5350a66d5279	1619	for(c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2;) {
hudakz	0:5350a66d5279	1620	opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c];
hudakz	0:5350a66d5279	1621	if(opt == TCP_OPT_END) {
hudakz	0:5350a66d5279	1622
hudakz	0:5350a66d5279	1623	/* End of options. */
hudakz	0:5350a66d5279	1624	break;
hudakz	0:5350a66d5279	1625	}
hudakz	0:5350a66d5279	1626	else
hudakz	0:5350a66d5279	1627	if(opt == TCP_OPT_NOOP) {
hudakz	0:5350a66d5279	1628	++c;
hudakz	0:5350a66d5279	1629
hudakz	0:5350a66d5279	1630	/* NOP option. */
hudakz	0:5350a66d5279	1631	}
hudakz	0:5350a66d5279	1632	else
hudakz	0:5350a66d5279	1633	if(opt == TCP_OPT_MSS && uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
hudakz	0:5350a66d5279	1634
hudakz	0:5350a66d5279	1635	/* An MSS option with the right option length. */
hudakz	0:5350a66d5279	1636	tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) \| uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
hudakz	0:5350a66d5279	1637	uip_connr->initialmss = uip_connr->mss = tmp16 > UIP_TCP_MSS ? UIP_TCP_MSS : tmp16;
hudakz	0:5350a66d5279	1638
hudakz	0:5350a66d5279	1639	/* And we are done processing options. */
hudakz	0:5350a66d5279	1640	break;
hudakz	0:5350a66d5279	1641	}
hudakz	0:5350a66d5279	1642	else {
hudakz	0:5350a66d5279	1643
hudakz	0:5350a66d5279	1644	/* All other options have a length field, so that we easily
hudakz	0:5350a66d5279	1645	can skip past them. */
hudakz	0:5350a66d5279	1646	if(uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
hudakz	0:5350a66d5279	1647
hudakz	0:5350a66d5279	1648	/* If the length field is zero, the options are malformed
hudakz	0:5350a66d5279	1649	and we don't process them further. */
hudakz	0:5350a66d5279	1650	break;
hudakz	0:5350a66d5279	1651	}
hudakz	0:5350a66d5279	1652
hudakz	0:5350a66d5279	1653	c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
hudakz	0:5350a66d5279	1654	}
hudakz	0:5350a66d5279	1655	}
hudakz	0:5350a66d5279	1656	}
hudakz	0:5350a66d5279	1657
hudakz	0:5350a66d5279	1658	uip_connr->tcpstateflags = UIP_ESTABLISHED;
hudakz	0:5350a66d5279	1659	uip_connr->rcv_nxt[0] = BUF->seqno[0];
hudakz	0:5350a66d5279	1660	uip_connr->rcv_nxt[1] = BUF->seqno[1];
hudakz	0:5350a66d5279	1661	uip_connr->rcv_nxt[2] = BUF->seqno[2];
hudakz	0:5350a66d5279	1662	uip_connr->rcv_nxt[3] = BUF->seqno[3];
hudakz	0:5350a66d5279	1663	uip_add_rcv_nxt(1);
hudakz	0:5350a66d5279	1664	uip_flags = UIP_CONNECTED \| UIP_NEWDATA;
hudakz	0:5350a66d5279	1665	uip_connr->len = 0;
hudakz	0:5350a66d5279	1666	uip_len = 0;
hudakz	0:5350a66d5279	1667	uip_slen = 0;
hudakz	0:5350a66d5279	1668	UIP_APPCALL();
hudakz	0:5350a66d5279	1669	goto appsend;
hudakz	0:5350a66d5279	1670	}
hudakz	0:5350a66d5279	1671
hudakz	0:5350a66d5279	1672	/* Inform the application that the connection failed */
hudakz	0:5350a66d5279	1673	uip_flags = UIP_ABORT;
hudakz	0:5350a66d5279	1674	UIP_APPCALL();
hudakz	0:5350a66d5279	1675
hudakz	0:5350a66d5279	1676	/* The connection is closed after we send the RST */
hudakz	0:5350a66d5279	1677	uip_conn->tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	1678	goto reset;
hudakz	0:5350a66d5279	1679	#endif /* UIP_ACTIVE_OPEN */
hudakz	0:5350a66d5279	1680
hudakz	0:5350a66d5279	1681	case UIP_ESTABLISHED:
hudakz	0:5350a66d5279	1682	/* In the ESTABLISHED state, we call upon the application to feed
hudakz	0:5350a66d5279	1683	data into the uip_buf. If the UIP_ACKDATA flag is set, the
hudakz	0:5350a66d5279	1684	application should put new data into the buffer, otherwise we are
hudakz	0:5350a66d5279	1685	retransmitting an old segment, and the application should put that
hudakz	0:5350a66d5279	1686	data into the buffer.
hudakz	0:5350a66d5279	1687
hudakz	0:5350a66d5279	1688	If the incoming packet is a FIN, we should close the connection on
hudakz	0:5350a66d5279	1689	this side as well, and we send out a FIN and enter the LAST_ACK
hudakz	0:5350a66d5279	1690	state. We require that there is no outstanding data; otherwise the
hudakz	0:5350a66d5279	1691	sequence numbers will be screwed up. */
hudakz	0:5350a66d5279	1692	if(BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
hudakz	0:5350a66d5279	1693	if(uip_outstanding(uip_connr)) {
hudakz	0:5350a66d5279	1694	goto drop;
hudakz	0:5350a66d5279	1695	}
hudakz	0:5350a66d5279	1696
hudakz	0:5350a66d5279	1697	uip_add_rcv_nxt(1 + uip_len);
hudakz	0:5350a66d5279	1698	uip_flags \|= UIP_CLOSE;
hudakz	0:5350a66d5279	1699	if(uip_len > 0) {
hudakz	0:5350a66d5279	1700	uip_flags \|= UIP_NEWDATA;
hudakz	0:5350a66d5279	1701	}
hudakz	0:5350a66d5279	1702
hudakz	0:5350a66d5279	1703	UIP_APPCALL();
hudakz	0:5350a66d5279	1704	uip_connr->len = 1;
hudakz	0:5350a66d5279	1705	uip_connr->tcpstateflags = UIP_LAST_ACK;
hudakz	0:5350a66d5279	1706	uip_connr->nrtx = 0;
hudakz	0:5350a66d5279	1707	tcp_send_finack:
hudakz	0:5350a66d5279	1708	BUF->flags = TCP_FIN \| TCP_ACK;
hudakz	0:5350a66d5279	1709	goto tcp_send_nodata;
hudakz	0:5350a66d5279	1710	}
hudakz	0:5350a66d5279	1711
hudakz	0:5350a66d5279	1712	/* Check the URG flag. If this is set, the segment carries urgent
hudakz	0:5350a66d5279	1713	data that we must pass to the application. */
hudakz	0:5350a66d5279	1714	if((BUF->flags & TCP_URG) != 0)
hudakz	0:5350a66d5279	1715	{
hudakz	0:5350a66d5279	1716	#if UIP_URGDATA > 0
hudakz	0:5350a66d5279	1717	uip_urglen = (BUF->urgp[0] << 8) \| BUF->urgp[1];
hudakz	0:5350a66d5279	1718	if(uip_urglen > uip_len) {
hudakz	0:5350a66d5279	1719
hudakz	0:5350a66d5279	1720	/* There is more urgent data in the next segment to come. */
hudakz	0:5350a66d5279	1721	uip_urglen = uip_len;
hudakz	0:5350a66d5279	1722	}
hudakz	0:5350a66d5279	1723
hudakz	0:5350a66d5279	1724	uip_add_rcv_nxt(uip_urglen);
hudakz	0:5350a66d5279	1725	uip_len -= uip_urglen;
hudakz	0:5350a66d5279	1726	uip_urgdata = uip_appdata;
hudakz	0:5350a66d5279	1727	uip_appdata += uip_urglen;
hudakz	0:5350a66d5279	1728	}
hudakz	0:5350a66d5279	1729	else {
hudakz	0:5350a66d5279	1730	uip_urglen = 0;
hudakz	0:5350a66d5279	1731	#else /* UIP_URGDATA > 0 */
hudakz	0:5350a66d5279	1732	uip_appdata = ((char*)uip_appdata) + ((BUF->urgp[0] << 8) \| BUF->urgp[1]);
hudakz	0:5350a66d5279	1733	uip_len -= (BUF->urgp[0] << 8) \| BUF->urgp[1];
hudakz	0:5350a66d5279	1734	#endif /* UIP_URGDATA > 0 */
hudakz	0:5350a66d5279	1735	}
hudakz	0:5350a66d5279	1736
hudakz	0:5350a66d5279	1737	/* If uip_len > 0 we have TCP data in the packet, and we flag this
hudakz	0:5350a66d5279	1738	by setting the UIP_NEWDATA flag and update the sequence number
hudakz	0:5350a66d5279	1739	we acknowledge. If the application has stopped the dataflow
hudakz	0:5350a66d5279	1740	using uip_stop(), we must not accept any data packets from the
hudakz	0:5350a66d5279	1741	remote host. */
hudakz	0:5350a66d5279	1742	if(uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
hudakz	0:5350a66d5279	1743	uip_flags \|= UIP_NEWDATA;
hudakz	0:5350a66d5279	1744	uip_add_rcv_nxt(uip_len);
hudakz	0:5350a66d5279	1745	}
hudakz	0:5350a66d5279	1746
hudakz	0:5350a66d5279	1747	/* Check if the available buffer space advertised by the other end
hudakz	0:5350a66d5279	1748	is smaller than the initial MSS for this connection. If so, we
hudakz	0:5350a66d5279	1749	set the current MSS to the window size to ensure that the
hudakz	0:5350a66d5279	1750	application does not send more data than the other end can
hudakz	0:5350a66d5279	1751	handle.
hudakz	0:5350a66d5279	1752
hudakz	0:5350a66d5279	1753	If the remote host advertises a zero window, we set the MSS to
hudakz	0:5350a66d5279	1754	the initial MSS so that the application will send an entire MSS
hudakz	0:5350a66d5279	1755	of data. This data will not be acknowledged by the receiver,
hudakz	0:5350a66d5279	1756	and the application will retransmit it. This is called the
hudakz	0:5350a66d5279	1757	"persistent timer" and uses the retransmission mechanim.
hudakz	0:5350a66d5279	1758	*/
hudakz	0:5350a66d5279	1759	tmp16 = ((u16_t) BUF->wnd[0] << 8) + (u16_t) BUF->wnd[1];
hudakz	0:5350a66d5279	1760	if(tmp16 > uip_connr->initialmss \|\| tmp16 == 0) {
hudakz	0:5350a66d5279	1761	tmp16 = uip_connr->initialmss;
hudakz	0:5350a66d5279	1762	}
hudakz	0:5350a66d5279	1763
hudakz	0:5350a66d5279	1764	uip_connr->mss = tmp16;
hudakz	0:5350a66d5279	1765
hudakz	0:5350a66d5279	1766	/* If this packet constitutes an ACK for outstanding data (flagged
hudakz	0:5350a66d5279	1767	by the UIP_ACKDATA flag, we should call the application since it
hudakz	0:5350a66d5279	1768	might want to send more data. If the incoming packet had data
hudakz	0:5350a66d5279	1769	from the peer (as flagged by the UIP_NEWDATA flag), the
hudakz	0:5350a66d5279	1770	application must also be notified.
hudakz	0:5350a66d5279	1771
hudakz	0:5350a66d5279	1772	When the application is called, the global variable uip_len
hudakz	0:5350a66d5279	1773	contains the length of the incoming data. The application can
hudakz	0:5350a66d5279	1774	access the incoming data through the global pointer
hudakz	0:5350a66d5279	1775	uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
hudakz	0:5350a66d5279	1776	bytes into the uip_buf array.
hudakz	0:5350a66d5279	1777
hudakz	0:5350a66d5279	1778	If the application wishes to send any data, this data should be
hudakz	0:5350a66d5279	1779	put into the uip_appdata and the length of the data should be
hudakz	0:5350a66d5279	1780	put into uip_len. If the application don't have any data to
hudakz	0:5350a66d5279	1781	send, uip_len must be set to 0. */
hudakz	0:5350a66d5279	1782	if(uip_flags & (UIP_NEWDATA \| UIP_ACKDATA)) {
hudakz	0:5350a66d5279	1783	uip_slen = 0;
hudakz	0:5350a66d5279	1784	UIP_APPCALL();
hudakz	0:5350a66d5279	1785
hudakz	0:5350a66d5279	1786	appsend:
hudakz	0:5350a66d5279	1787	if(uip_flags & UIP_ABORT) {
hudakz	0:5350a66d5279	1788	uip_slen = 0;
hudakz	0:5350a66d5279	1789	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	1790	BUF->flags = TCP_RST \| TCP_ACK;
hudakz	0:5350a66d5279	1791	goto tcp_send_nodata;
hudakz	0:5350a66d5279	1792	}
hudakz	0:5350a66d5279	1793
hudakz	0:5350a66d5279	1794	if(uip_flags & UIP_CLOSE) {
hudakz	0:5350a66d5279	1795	uip_slen = 0;
hudakz	0:5350a66d5279	1796	uip_connr->len = 1;
hudakz	0:5350a66d5279	1797	uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
hudakz	0:5350a66d5279	1798	uip_connr->nrtx = 0;
hudakz	0:5350a66d5279	1799	BUF->flags = TCP_FIN \| TCP_ACK;
hudakz	0:5350a66d5279	1800	goto tcp_send_nodata;
hudakz	0:5350a66d5279	1801	}
hudakz	0:5350a66d5279	1802
hudakz	0:5350a66d5279	1803	/* If uip_slen > 0, the application has data to be sent. */
hudakz	0:5350a66d5279	1804	if(uip_slen > 0) {
hudakz	0:5350a66d5279	1805
hudakz	0:5350a66d5279	1806	/* If the connection has acknowledged data, the contents of
hudakz	0:5350a66d5279	1807	the ->len variable should be discarded. */
hudakz	0:5350a66d5279	1808	if((uip_flags & UIP_ACKDATA) != 0) {
hudakz	0:5350a66d5279	1809	uip_connr->len = 0;
hudakz	0:5350a66d5279	1810	}
hudakz	0:5350a66d5279	1811
hudakz	0:5350a66d5279	1812	/* If the ->len variable is non-zero the connection has
hudakz	0:5350a66d5279	1813	already data in transit and cannot send anymore right
hudakz	0:5350a66d5279	1814	now. */
hudakz	0:5350a66d5279	1815	if(uip_connr->len == 0) {
hudakz	0:5350a66d5279	1816
hudakz	0:5350a66d5279	1817	/* The application cannot send more than what is allowed by
hudakz	0:5350a66d5279	1818	the mss (the minumum of the MSS and the available
hudakz	0:5350a66d5279	1819	window). */
hudakz	0:5350a66d5279	1820	if(uip_slen > uip_connr->mss) {
hudakz	0:5350a66d5279	1821	uip_slen = uip_connr->mss;
hudakz	0:5350a66d5279	1822	}
hudakz	0:5350a66d5279	1823
hudakz	0:5350a66d5279	1824	/* Remember how much data we send out now so that we know
hudakz	0:5350a66d5279	1825	when everything has been acknowledged. */
hudakz	0:5350a66d5279	1826	uip_connr->len = uip_slen;
hudakz	0:5350a66d5279	1827	}
hudakz	0:5350a66d5279	1828	else {
hudakz	0:5350a66d5279	1829
hudakz	0:5350a66d5279	1830	/* If the application already had unacknowledged data, we
hudakz	0:5350a66d5279	1831	make sure that the application does not send (i.e.,
hudakz	0:5350a66d5279	1832	retransmit) out more than it previously sent out. */
hudakz	0:5350a66d5279	1833	uip_slen = uip_connr->len;
hudakz	0:5350a66d5279	1834	}
hudakz	0:5350a66d5279	1835	}
hudakz	0:5350a66d5279	1836
hudakz	0:5350a66d5279	1837	uip_connr->nrtx = 0;
hudakz	0:5350a66d5279	1838	apprexmit:
hudakz	0:5350a66d5279	1839	uip_appdata = uip_sappdata;
hudakz	0:5350a66d5279	1840
hudakz	0:5350a66d5279	1841	/* If the application has data to be sent, or if the incoming
hudakz	0:5350a66d5279	1842	packet had new data in it, we must send out a packet. */
hudakz	0:5350a66d5279	1843	if(uip_slen > 0 && uip_connr->len > 0) {
hudakz	0:5350a66d5279	1844
hudakz	0:5350a66d5279	1845	/* Add the length of the IP and TCP headers. */
hudakz	0:5350a66d5279	1846	uip_len = uip_connr->len + UIP_TCPIP_HLEN;
hudakz	0:5350a66d5279	1847
hudakz	0:5350a66d5279	1848	/* We always set the ACK flag in response packets. */
hudakz	0:5350a66d5279	1849	BUF->flags = TCP_ACK \| TCP_PSH;
hudakz	0:5350a66d5279	1850
hudakz	0:5350a66d5279	1851	/* Send the packet. */
hudakz	0:5350a66d5279	1852	goto tcp_send_noopts;
hudakz	0:5350a66d5279	1853	}
hudakz	0:5350a66d5279	1854
hudakz	0:5350a66d5279	1855	/* If there is no data to send, just send out a pure ACK if
hudakz	0:5350a66d5279	1856	there is newdata. */
hudakz	0:5350a66d5279	1857	if(uip_flags & UIP_NEWDATA) {
hudakz	0:5350a66d5279	1858	uip_len = UIP_TCPIP_HLEN;
hudakz	0:5350a66d5279	1859	BUF->flags = TCP_ACK;
hudakz	0:5350a66d5279	1860	goto tcp_send_noopts;
hudakz	0:5350a66d5279	1861	}
hudakz	0:5350a66d5279	1862	}
hudakz	0:5350a66d5279	1863
hudakz	0:5350a66d5279	1864	goto drop;
hudakz	0:5350a66d5279	1865
hudakz	0:5350a66d5279	1866	case UIP_LAST_ACK:
hudakz	0:5350a66d5279	1867	/* We can close this connection if the peer has acknowledged our
hudakz	0:5350a66d5279	1868	FIN. This is indicated by the UIP_ACKDATA flag. */
hudakz	0:5350a66d5279	1869	if(uip_flags & UIP_ACKDATA) {
hudakz	0:5350a66d5279	1870	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	0:5350a66d5279	1871	uip_flags = UIP_CLOSE;
hudakz	0:5350a66d5279	1872	UIP_APPCALL();
hudakz	0:5350a66d5279	1873	}
hudakz	0:5350a66d5279	1874	break;
hudakz	0:5350a66d5279	1875
hudakz	0:5350a66d5279	1876	case UIP_FIN_WAIT_1:
hudakz	0:5350a66d5279	1877	/* The application has closed the connection, but the remote host
hudakz	0:5350a66d5279	1878	hasn't closed its end yet. Thus we do nothing but wait for a
hudakz	0:5350a66d5279	1879	FIN from the other side. */
hudakz	0:5350a66d5279	1880	if(uip_len > 0) {
hudakz	0:5350a66d5279	1881	uip_add_rcv_nxt(uip_len);
hudakz	0:5350a66d5279	1882	}
hudakz	0:5350a66d5279	1883
hudakz	0:5350a66d5279	1884	if(BUF->flags & TCP_FIN) {
hudakz	0:5350a66d5279	1885	if(uip_flags & UIP_ACKDATA) {
hudakz	0:5350a66d5279	1886	uip_connr->tcpstateflags = UIP_TIME_WAIT;
hudakz	0:5350a66d5279	1887	uip_connr->timer = 0;
hudakz	0:5350a66d5279	1888	uip_connr->len = 0;
hudakz	0:5350a66d5279	1889	}
hudakz	0:5350a66d5279	1890	else {
hudakz	0:5350a66d5279	1891	uip_connr->tcpstateflags = UIP_CLOSING;
hudakz	0:5350a66d5279	1892	}
hudakz	0:5350a66d5279	1893
hudakz	0:5350a66d5279	1894	uip_add_rcv_nxt(1);
hudakz	0:5350a66d5279	1895	uip_flags = UIP_CLOSE;
hudakz	0:5350a66d5279	1896	UIP_APPCALL();
hudakz	0:5350a66d5279	1897	goto tcp_send_ack;
hudakz	0:5350a66d5279	1898	}
hudakz	0:5350a66d5279	1899	else
hudakz	0:5350a66d5279	1900	if(uip_flags & UIP_ACKDATA) {
hudakz	0:5350a66d5279	1901	uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
hudakz	0:5350a66d5279	1902	uip_connr->len = 0;
hudakz	0:5350a66d5279	1903	goto drop;
hudakz	0:5350a66d5279	1904	}
hudakz	0:5350a66d5279	1905
hudakz	0:5350a66d5279	1906	if(uip_len > 0) {
hudakz	0:5350a66d5279	1907	goto tcp_send_ack;
hudakz	0:5350a66d5279	1908	}
hudakz	0:5350a66d5279	1909
hudakz	0:5350a66d5279	1910	goto drop;
hudakz	0:5350a66d5279	1911
hudakz	0:5350a66d5279	1912	case UIP_FIN_WAIT_2:
hudakz	0:5350a66d5279	1913	if(uip_len > 0) {
hudakz	0:5350a66d5279	1914	uip_add_rcv_nxt(uip_len);
hudakz	0:5350a66d5279	1915	}
hudakz	0:5350a66d5279	1916
hudakz	0:5350a66d5279	1917	if(BUF->flags & TCP_FIN) {
hudakz	0:5350a66d5279	1918	uip_connr->tcpstateflags = UIP_TIME_WAIT;
hudakz	0:5350a66d5279	1919	uip_connr->timer = 0;
hudakz	0:5350a66d5279	1920	uip_add_rcv_nxt(1);
hudakz	0:5350a66d5279	1921	uip_flags = UIP_CLOSE;
hudakz	0:5350a66d5279	1922	UIP_APPCALL();
hudakz	0:5350a66d5279	1923	goto tcp_send_ack;
hudakz	0:5350a66d5279	1924	}
hudakz	0:5350a66d5279	1925
hudakz	0:5350a66d5279	1926	if(uip_len > 0) {
hudakz	0:5350a66d5279	1927	goto tcp_send_ack;
hudakz	0:5350a66d5279	1928	}
hudakz	0:5350a66d5279	1929
hudakz	0:5350a66d5279	1930	goto drop;
hudakz	0:5350a66d5279	1931
hudakz	0:5350a66d5279	1932	case UIP_TIME_WAIT:
hudakz	0:5350a66d5279	1933	goto tcp_send_ack;
hudakz	0:5350a66d5279	1934
hudakz	0:5350a66d5279	1935	case UIP_CLOSING:
hudakz	0:5350a66d5279	1936	if(uip_flags & UIP_ACKDATA) {
hudakz	0:5350a66d5279	1937	uip_connr->tcpstateflags = UIP_TIME_WAIT;
hudakz	0:5350a66d5279	1938	uip_connr->timer = 0;
hudakz	0:5350a66d5279	1939	}
hudakz	0:5350a66d5279	1940	}
hudakz	0:5350a66d5279	1941
hudakz	0:5350a66d5279	1942	goto drop;
hudakz	0:5350a66d5279	1943
hudakz	0:5350a66d5279	1944	/* We jump here when we are ready to send the packet, and just want
hudakz	0:5350a66d5279	1945	to set the appropriate TCP sequence numbers in the TCP header. */
hudakz	0:5350a66d5279	1946	tcp_send_ack:
hudakz	0:5350a66d5279	1947	BUF->flags = TCP_ACK;
hudakz	0:5350a66d5279	1948	tcp_send_nodata:
hudakz	0:5350a66d5279	1949	uip_len = UIP_IPTCPH_LEN;
hudakz	0:5350a66d5279	1950	tcp_send_noopts:
hudakz	0:5350a66d5279	1951	BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
hudakz	0:5350a66d5279	1952	tcp_send:
hudakz	0:5350a66d5279	1953	/* We're done with the input processing. We are now ready to send a
hudakz	0:5350a66d5279	1954	reply. Our job is to fill in all the fields of the TCP and IP
hudakz	0:5350a66d5279	1955	headers before calculating the checksum and finally send the
hudakz	0:5350a66d5279	1956	packet. */
hudakz	0:5350a66d5279	1957	BUF->ackno[0] = uip_connr->rcv_nxt[0];
hudakz	0:5350a66d5279	1958	BUF->ackno[1] = uip_connr->rcv_nxt[1];
hudakz	0:5350a66d5279	1959	BUF->ackno[2] = uip_connr->rcv_nxt[2];
hudakz	0:5350a66d5279	1960	BUF->ackno[3] = uip_connr->rcv_nxt[3];
hudakz	0:5350a66d5279	1961
hudakz	0:5350a66d5279	1962	BUF->seqno[0] = uip_connr->snd_nxt[0];
hudakz	0:5350a66d5279	1963	BUF->seqno[1] = uip_connr->snd_nxt[1];
hudakz	0:5350a66d5279	1964	BUF->seqno[2] = uip_connr->snd_nxt[2];
hudakz	0:5350a66d5279	1965	BUF->seqno[3] = uip_connr->snd_nxt[3];
hudakz	0:5350a66d5279	1966
hudakz	0:5350a66d5279	1967	BUF->proto = UIP_PROTO_TCP;
hudakz	0:5350a66d5279	1968
hudakz	0:5350a66d5279	1969	BUF->srcport = uip_connr->lport;
hudakz	0:5350a66d5279	1970	BUF->destport = uip_connr->rport;
hudakz	0:5350a66d5279	1971
hudakz	0:5350a66d5279	1972	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	0:5350a66d5279	1973	uip_ipaddr_copy(BUF->destipaddr, uip_connr->ripaddr);
hudakz	0:5350a66d5279	1974
hudakz	0:5350a66d5279	1975	if(uip_connr->tcpstateflags & UIP_STOPPED) {
hudakz	0:5350a66d5279	1976
hudakz	0:5350a66d5279	1977	/* If the connection has issued uip_stop(), we advertise a zero
hudakz	0:5350a66d5279	1978	window so that the remote host will stop sending data. */
hudakz	0:5350a66d5279	1979	BUF->wnd[0] = BUF->wnd[1] = 0;
hudakz	0:5350a66d5279	1980	}
hudakz	0:5350a66d5279	1981	else {
hudakz	0:5350a66d5279	1982	BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
hudakz	0:5350a66d5279	1983	BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
hudakz	0:5350a66d5279	1984	}
hudakz	0:5350a66d5279	1985
hudakz	0:5350a66d5279	1986	tcp_send_noconn:
hudakz	0:5350a66d5279	1987	BUF->ttl = UIP_TTL;
hudakz	0:5350a66d5279	1988	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	1989	/* For IPv6, the IP length field does not include the IPv6 IP header
hudakz	0:5350a66d5279	1990	length. */
hudakz	0:5350a66d5279	1991
hudakz	0:5350a66d5279	1992	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
hudakz	0:5350a66d5279	1993	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
hudakz	0:5350a66d5279	1994	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1995	BUF->len[0] = (uip_len >> 8);
hudakz	0:5350a66d5279	1996	BUF->len[1] = (uip_len & 0xff);
hudakz	0:5350a66d5279	1997	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	1998
hudakz	0:5350a66d5279	1999	BUF->urgp[0] = BUF->urgp[1] = 0;
hudakz	0:5350a66d5279	2000
hudakz	0:5350a66d5279	2001	/* Calculate TCP checksum. */
hudakz	0:5350a66d5279	2002	BUF->tcpchksum = 0;
hudakz	0:5350a66d5279	2003	BUF->tcpchksum = ~(uip_tcpchksum());
hudakz	0:5350a66d5279	2004
hudakz	0:5350a66d5279	2005	ip_send_nolen:
hudakz	0:5350a66d5279	2006	#if UIP_CONF_IPV6
hudakz	0:5350a66d5279	2007	BUF->vtc = 0x60;
hudakz	0:5350a66d5279	2008	BUF->tcflow = 0x00;
hudakz	0:5350a66d5279	2009	BUF->flow = 0x00;
hudakz	0:5350a66d5279	2010	#else /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	2011	BUF->vhl = 0x45;
hudakz	0:5350a66d5279	2012	BUF->tos = 0;
hudakz	0:5350a66d5279	2013	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
hudakz	0:5350a66d5279	2014	++ipid;
hudakz	0:5350a66d5279	2015	BUF->ipid[0] = ipid >> 8;
hudakz	0:5350a66d5279	2016	BUF->ipid[1] = ipid & 0xff;
hudakz	0:5350a66d5279	2017
hudakz	0:5350a66d5279	2018	/* Calculate IP checksum. */
hudakz	0:5350a66d5279	2019	BUF->ipchksum = 0;
hudakz	0:5350a66d5279	2020	BUF->ipchksum = ~(uip_ipchksum());
hudakz	0:5350a66d5279	2021	DEBUG_PRINTF("uip ip_send_nolen: chkecum 0x%04x\n", uip_ipchksum());
hudakz	0:5350a66d5279	2022	#endif /* UIP_CONF_IPV6 */
hudakz	0:5350a66d5279	2023
hudakz	0:5350a66d5279	2024	UIP_STAT(++uip_stat.tcp.sent);
hudakz	0:5350a66d5279	2025	send:
hudakz	0:5350a66d5279	2026	DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len, (BUF->len[0] << 8) \| BUF->len[1]);
hudakz	0:5350a66d5279	2027
hudakz	0:5350a66d5279	2028	UIP_STAT(++uip_stat.ip.sent);
hudakz	0:5350a66d5279	2029
hudakz	0:5350a66d5279	2030	/* Return and let the caller do the actual transmission. */
hudakz	0:5350a66d5279	2031	uip_flags = 0;
hudakz	0:5350a66d5279	2032	return;
hudakz	0:5350a66d5279	2033	drop:
hudakz	0:5350a66d5279	2034	uip_len = 0;
hudakz	0:5350a66d5279	2035	uip_flags = 0;
hudakz	0:5350a66d5279	2036	return;
hudakz	0:5350a66d5279	2037	}
hudakz	0:5350a66d5279	2038
hudakz	0:5350a66d5279	2039	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	2040	u16_t htons(u16_t val) {
hudakz	0:5350a66d5279	2041	return HTONS(val);
hudakz	0:5350a66d5279	2042	}
hudakz	0:5350a66d5279	2043
hudakz	0:5350a66d5279	2044	/---------------------------------------------------------------------------/
hudakz	0:5350a66d5279	2045	void uip_send(const void* data, int len) {
hudakz	0:5350a66d5279	2046	uip_slen = len;
hudakz	0:5350a66d5279	2047	if(len > 0) {
hudakz	0:5350a66d5279	2048	if(data != uip_sappdata) {
hudakz	0:5350a66d5279	2049	memcpy(uip_sappdata, (data), uip_slen);
hudakz	0:5350a66d5279	2050	}
hudakz	0:5350a66d5279	2051	}
hudakz	0:5350a66d5279	2052	}
hudakz	0:5350a66d5279	2053
hudakz	0:5350a66d5279	2054	/** @} */

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Type:	Library
Created:	06 Jun 2022
Imports:	0
Forks:	0
Commits:	20
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uitility/uip.c@0:5350a66d5279, 2014-09-15 (annotated)

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