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utility/uip.c@19:543c2d21e510, 2022-06-06 (annotated)

Committer:: advxolltm
Date:: Mon Jun 06 16:36:52 2022 +0000
Revision:: 19:543c2d21e510
Parent:: 8:4acb22344932

Who changed what in which revision?

User	Revision	Line number	New contents of line
hudakz	3:5b17e4656dd0	1	#define DEBUG_PRINTF(...) /printf(__VA_ARGS__)/
hudakz	3:5b17e4656dd0	2
hudakz	3:5b17e4656dd0	3	/**
hudakz	8:4acb22344932	4	* \defgroup uip The UIP TCP/IP stack
hudakz	3:5b17e4656dd0	5	* @{
hudakz	3:5b17e4656dd0	6	*
hudakz	8:4acb22344932	7	* UIP is an implementation of the TCP/IP protocol stack intended for
hudakz	3:5b17e4656dd0	8	* small 8-bit and 16-bit microcontrollers.
hudakz	3:5b17e4656dd0	9	*
hudakz	8:4acb22344932	10	* UIP provides the necessary protocols for Internet communication,
hudakz	8:4acb22344932	11	* with a very small code footprint and RAM requirements - the UIP
hudakz	3:5b17e4656dd0	12	* code size is on the order of a few kilobytes and RAM usage is on
hudakz	3:5b17e4656dd0	13	* the order of a few hundred bytes.
hudakz	3:5b17e4656dd0	14	*/
hudakz	3:5b17e4656dd0	15
hudakz	3:5b17e4656dd0	16	/**
hudakz	3:5b17e4656dd0	17	* \file
hudakz	8:4acb22344932	18	* The UIP TCP/IP stack code.
hudakz	3:5b17e4656dd0	19	* \author Adam Dunkels <adam@dunkels.com>
hudakz	3:5b17e4656dd0	20	*/
hudakz	3:5b17e4656dd0	21	/*
hudakz	3:5b17e4656dd0	22	* Copyright (c) 2001-2003, Adam Dunkels.
hudakz	3:5b17e4656dd0	23	* All rights reserved.
hudakz	3:5b17e4656dd0	24	*
hudakz	3:5b17e4656dd0	25	* Redistribution and use in source and binary forms, with or without
hudakz	3:5b17e4656dd0	26	* modification, are permitted provided that the following conditions
hudakz	3:5b17e4656dd0	27	* are met:
hudakz	3:5b17e4656dd0	28	* 1. Redistributions of source code must retain the above copyright
hudakz	3:5b17e4656dd0	29	* notice, this list of conditions and the following disclaimer.
hudakz	3:5b17e4656dd0	30	* 2. Redistributions in binary form must reproduce the above copyright
hudakz	3:5b17e4656dd0	31	* notice, this list of conditions and the following disclaimer in the
hudakz	3:5b17e4656dd0	32	* documentation and/or other materials provided with the distribution.
hudakz	3:5b17e4656dd0	33	* 3. The name of the author may not be used to endorse or promote
hudakz	3:5b17e4656dd0	34	* products derived from this software without specific prior
hudakz	3:5b17e4656dd0	35	* written permission.
hudakz	3:5b17e4656dd0	36	*
hudakz	3:5b17e4656dd0	37	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS
hudakz	3:5b17e4656dd0	38	* OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
hudakz	3:5b17e4656dd0	39	* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
hudakz	3:5b17e4656dd0	40	* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
hudakz	3:5b17e4656dd0	41	* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
hudakz	3:5b17e4656dd0	42	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
hudakz	3:5b17e4656dd0	43	* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hudakz	3:5b17e4656dd0	44	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
hudakz	3:5b17e4656dd0	45	* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
hudakz	3:5b17e4656dd0	46	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
hudakz	3:5b17e4656dd0	47	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
hudakz	3:5b17e4656dd0	48	*
hudakz	8:4acb22344932	49	* This file is part of the UIP TCP/IP stack.
hudakz	3:5b17e4656dd0	50	*
hudakz	3:5b17e4656dd0	51	* $Id: uip.c,v 1.65 2006/06/11 21:46:39 adam Exp $
hudakz	3:5b17e4656dd0	52	*
hudakz	3:5b17e4656dd0	53	*/
hudakz	3:5b17e4656dd0	54	/*
hudakz	8:4acb22344932	55	* UIP is a small implementation of the IP, UDP and TCP protocols (as
hudakz	3:5b17e4656dd0	56	* well as some basic ICMP stuff). The implementation couples the IP,
hudakz	3:5b17e4656dd0	57	* UDP, TCP and the application layers very tightly. To keep the size
hudakz	3:5b17e4656dd0	58	* of the compiled code down, this code frequently uses the goto
hudakz	3:5b17e4656dd0	59	* statement. While it would be possible to break the uip_process()
hudakz	3:5b17e4656dd0	60	* function into many smaller functions, this would increase the code
hudakz	3:5b17e4656dd0	61	* size because of the overhead of parameter passing and the fact that
hudakz	3:5b17e4656dd0	62	* the optimier would not be as efficient.
hudakz	3:5b17e4656dd0	63	*
hudakz	3:5b17e4656dd0	64	* The principle is that we have a small buffer, called the uip_buf,
hudakz	3:5b17e4656dd0	65	* in which the device driver puts an incoming packet. The TCP/IP
hudakz	3:5b17e4656dd0	66	* stack parses the headers in the packet, and calls the
hudakz	3:5b17e4656dd0	67	* application. If the remote host has sent data to the application,
hudakz	3:5b17e4656dd0	68	* this data is present in the uip_buf and the application read the
hudakz	3:5b17e4656dd0	69	* data from there. It is up to the application to put this data into
hudakz	3:5b17e4656dd0	70	* a byte stream if needed. The application will not be fed with data
hudakz	3:5b17e4656dd0	71	* that is out of sequence.
hudakz	3:5b17e4656dd0	72	*
hudakz	3:5b17e4656dd0	73	* If the application whishes to send data to the peer, it should put
hudakz	3:5b17e4656dd0	74	* its data into the uip_buf. The uip_appdata pointer points to the
hudakz	3:5b17e4656dd0	75	* first available byte. The TCP/IP stack will calculate the
hudakz	3:5b17e4656dd0	76	* checksums, and fill in the necessary header fields and finally send
hudakz	3:5b17e4656dd0	77	* the packet back to the peer.
hudakz	3:5b17e4656dd0	78	*/
hudakz	3:5b17e4656dd0	79	#include "uip.h"
hudakz	3:5b17e4656dd0	80	#include "uipopt.h"
hudakz	3:5b17e4656dd0	81	#include "uip_arch.h"
hudakz	3:5b17e4656dd0	82
hudakz	3:5b17e4656dd0	83	#if UIP_CONF_IPV6
hudakz	8:4acb22344932	84	#include "uip-neighbor.h"
hudakz	3:5b17e4656dd0	85	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	86
hudakz	3:5b17e4656dd0	87	#include <string.h>
hudakz	3:5b17e4656dd0	88
hudakz	3:5b17e4656dd0	89	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	90
hudakz	3:5b17e4656dd0	91	/* Variable definitions. */
hudakz	3:5b17e4656dd0	92	/* The IP address of this host. If it is defined to be fixed (by
hudakz	3:5b17e4656dd0	93	setting UIP_FIXEDADDR to 1 in uipopt.h), the address is set
hudakz	3:5b17e4656dd0	94	here. Otherwise, the address */
hudakz	3:5b17e4656dd0	95	#if UIP_FIXEDADDR > 0
hudakz	3:5b17e4656dd0	96	const uip_ipaddr_t uip_hostaddr = { HTONS((UIP_IPADDR0 << 8) \| UIP_IPADDR1), HTONS
hudakz	3:5b17e4656dd0	97	((UIP_IPADDR2 << 8) \| UIP_IPADDR3) };
hudakz	3:5b17e4656dd0	98	const uip_ipaddr_t uip_draddr =
hudakz	3:5b17e4656dd0	99	{
hudakz	3:5b17e4656dd0	100	HTONS((UIP_DRIPADDR0 << 8) \| UIP_DRIPADDR1),
hudakz	3:5b17e4656dd0	101	HTONS((UIP_DRIPADDR2 << 8) \| UIP_DRIPADDR3)
hudakz	3:5b17e4656dd0	102	};
hudakz	3:5b17e4656dd0	103	const uip_ipaddr_t uip_netmask =
hudakz	3:5b17e4656dd0	104	{
hudakz	3:5b17e4656dd0	105	HTONS((UIP_NETMASK0 << 8) \| UIP_NETMASK1),
hudakz	3:5b17e4656dd0	106	HTONS((UIP_NETMASK2 << 8) \| UIP_NETMASK3)
hudakz	3:5b17e4656dd0	107	};
hudakz	3:5b17e4656dd0	108	#else
hudakz	3:5b17e4656dd0	109	uip_ipaddr_t uip_hostaddr, uip_draddr, uip_netmask;
hudakz	3:5b17e4656dd0	110	#endif /* UIP_FIXEDADDR */
hudakz	3:5b17e4656dd0	111
hudakz	3:5b17e4656dd0	112	static const uip_ipaddr_t all_ones_addr =
hudakz	3:5b17e4656dd0	113	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	114	{ 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff };
hudakz	3:5b17e4656dd0	115	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	116	{
hudakz	3:5b17e4656dd0	117	0xffff, 0xffff
hudakz	3:5b17e4656dd0	118	};
hudakz	3:5b17e4656dd0	119	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	120	static const uip_ipaddr_t all_zeroes_addr =
hudakz	3:5b17e4656dd0	121	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	122	{ 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000, 0x0000 };
hudakz	3:5b17e4656dd0	123	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	124	{
hudakz	3:5b17e4656dd0	125	0x0000, 0x0000
hudakz	3:5b17e4656dd0	126	};
hudakz	3:5b17e4656dd0	127	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	128
hudakz	3:5b17e4656dd0	129	#if UIP_FIXEDETHADDR
hudakz	3:5b17e4656dd0	130	const struct uip_eth_addr uip_ethaddr =
hudakz	3:5b17e4656dd0	131	{
hudakz	3:5b17e4656dd0	132	{ UIP_ETHADDR0, UIP_ETHADDR1, UIP_ETHADDR2, UIP_ETHADDR3, UIP_ETHADDR4, UIP_ETHADDR5 }
hudakz	3:5b17e4656dd0	133	};
hudakz	3:5b17e4656dd0	134	#else
hudakz	3:5b17e4656dd0	135	struct uip_eth_addr uip_ethaddr = { { 0, 0, 0, 0, 0, 0 } };
hudakz	3:5b17e4656dd0	136	#endif
hudakz	3:5b17e4656dd0	137	#ifndef UIP_CONF_EXTERNAL_BUFFER
hudakz	3:5b17e4656dd0	138	u8_t uip_buf[UIP_BUFSIZE + 2]; /* The packet buffer that contains
hudakz	4:d774541a34da	139	incoming packets. */
hudakz	3:5b17e4656dd0	140	#endif /* UIP_CONF_EXTERNAL_BUFFER */
hudakz	3:5b17e4656dd0	141
hudakz	3:5b17e4656dd0	142	void* uip_appdata; /* The uip_appdata pointer points to
hudakz	4:d774541a34da	143	application data. */
hudakz	3:5b17e4656dd0	144	void* uip_sappdata; /* The uip_appdata pointer points to
hudakz	4:d774541a34da	145	the application data which is to
hudakz	4:d774541a34da	146	be sent. */
hudakz	3:5b17e4656dd0	147	#if UIP_URGDATA > 0
hudakz	3:5b17e4656dd0	148	void* uip_urgdata; /* The uip_urgdata pointer points to
hudakz	4:d774541a34da	149	urgent data (out-of-band data), if
hudakz	4:d774541a34da	150	present. */
hudakz	3:5b17e4656dd0	151	u16_t uip_urglen, uip_surglen;
hudakz	3:5b17e4656dd0	152	#endif /* UIP_URGDATA > 0 */
hudakz	3:5b17e4656dd0	153
hudakz	3:5b17e4656dd0	154	u16_t uip_len, uip_slen;
hudakz	3:5b17e4656dd0	155
hudakz	3:5b17e4656dd0	156	/* The uip_len is either 8 or 16 bits,
hudakz	4:d774541a34da	157	depending on the maximum packet
hudakz	4:d774541a34da	158	size. */
hudakz	3:5b17e4656dd0	159	u8_t uip_flags; /* The uip_flags variable is used for
hudakz	4:d774541a34da	160	communication between the TCP/IP stack
hudakz	4:d774541a34da	161	and the application program. */
hudakz	3:5b17e4656dd0	162	struct uip_conn* uip_conn; /* uip_conn always points to the current
hudakz	4:d774541a34da	163	connection. */
hudakz	3:5b17e4656dd0	164
hudakz	3:5b17e4656dd0	165	struct uip_conn uip_conns[UIP_CONNS];
hudakz	3:5b17e4656dd0	166
hudakz	3:5b17e4656dd0	167	/* The uip_conns array holds all TCP
hudakz	4:d774541a34da	168	connections. */
hudakz	3:5b17e4656dd0	169	u16_t uip_listenports[UIP_LISTENPORTS];
hudakz	3:5b17e4656dd0	170
hudakz	3:5b17e4656dd0	171	/* The uip_listenports list all currently
hudakz	4:d774541a34da	172	listning ports. */
hudakz	3:5b17e4656dd0	173	#if UIP_UDP
hudakz	3:5b17e4656dd0	174	struct uip_udp_conn* uip_udp_conn;
hudakz	3:5b17e4656dd0	175	struct uip_udp_conn uip_udp_conns[UIP_UDP_CONNS];
hudakz	3:5b17e4656dd0	176	#endif /* UIP_UDP */
hudakz	3:5b17e4656dd0	177
hudakz	3:5b17e4656dd0	178	static u16_t ipid; /* Ths ipid variable is an increasing
hudakz	4:d774541a34da	179	number that is used for the IP ID
hudakz	4:d774541a34da	180	field. */
hudakz	3:5b17e4656dd0	181
hudakz	3:5b17e4656dd0	182	/**
hudakz	3:5b17e4656dd0	183	* @brief
hudakz	3:5b17e4656dd0	184	* @note
hudakz	3:5b17e4656dd0	185	* @param
hudakz	3:5b17e4656dd0	186	* @retval
hudakz	3:5b17e4656dd0	187	*/
hudakz	3:5b17e4656dd0	188	void uip_setipid(u16_t id) {
hudakz	3:5b17e4656dd0	189	ipid = id;
hudakz	3:5b17e4656dd0	190	}
hudakz	3:5b17e4656dd0	191
hudakz	3:5b17e4656dd0	192	static u8_t iss[4]; /* The iss variable is used for the TCP
hudakz	4:d774541a34da	193	initial sequence number. */
hudakz	3:5b17e4656dd0	194
hudakz	3:5b17e4656dd0	195	#if UIP_ACTIVE_OPEN
hudakz	3:5b17e4656dd0	196	static u16_t lastport; /* Keeps track of the last port used for
hudakz	4:d774541a34da	197	a new connection. */
hudakz	3:5b17e4656dd0	198	#endif /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	199
hudakz	3:5b17e4656dd0	200	/* Temporary variables. */
hudakz	3:5b17e4656dd0	201
hudakz	3:5b17e4656dd0	202	u8_t uip_acc32[4];
hudakz	3:5b17e4656dd0	203	static u8_t c, opt;
hudakz	3:5b17e4656dd0	204	static u16_t tmp16;
hudakz	3:5b17e4656dd0	205
hudakz	3:5b17e4656dd0	206	/* Structures and definitions. */
hudakz	3:5b17e4656dd0	207
hudakz	3:5b17e4656dd0	208	#define TCP_FIN 0x01
hudakz	3:5b17e4656dd0	209	#define TCP_SYN 0x02
hudakz	3:5b17e4656dd0	210	#define TCP_RST 0x04
hudakz	3:5b17e4656dd0	211	#define TCP_PSH 0x08
hudakz	3:5b17e4656dd0	212	#define TCP_ACK 0x10
hudakz	3:5b17e4656dd0	213	#define TCP_URG 0x20
hudakz	3:5b17e4656dd0	214	#define TCP_CTL 0x3f
hudakz	3:5b17e4656dd0	215
hudakz	3:5b17e4656dd0	216	#define TCP_OPT_END 0 /* End of TCP options list */
hudakz	3:5b17e4656dd0	217
hudakz	3:5b17e4656dd0	218	#define TCP_OPT_NOOP 1 /* "No-operation" TCP option */
hudakz	3:5b17e4656dd0	219
hudakz	3:5b17e4656dd0	220	#define TCP_OPT_MSS 2 /* Maximum segment size TCP option */
hudakz	3:5b17e4656dd0	221
hudakz	3:5b17e4656dd0	222	#define TCP_OPT_MSS_LEN 4 /* Length of TCP MSS option. */
hudakz	3:5b17e4656dd0	223
hudakz	3:5b17e4656dd0	224	#define ICMP_ECHO_REPLY 0
hudakz	3:5b17e4656dd0	225	#define ICMP_ECHO 8
hudakz	3:5b17e4656dd0	226
hudakz	3:5b17e4656dd0	227	#define ICMP6_ECHO_REPLY 129
hudakz	3:5b17e4656dd0	228	#define ICMP6_ECHO 128
hudakz	3:5b17e4656dd0	229	#define ICMP6_NEIGHBOR_SOLICITATION 135
hudakz	3:5b17e4656dd0	230	#define ICMP6_NEIGHBOR_ADVERTISEMENT 136
hudakz	3:5b17e4656dd0	231
hudakz	3:5b17e4656dd0	232	#define ICMP6_FLAG_S (1 << 6)
hudakz	3:5b17e4656dd0	233	#define ICMP6_OPTION_SOURCE_LINK_ADDRESS 1
hudakz	3:5b17e4656dd0	234	#define ICMP6_OPTION_TARGET_LINK_ADDRESS 2
hudakz	3:5b17e4656dd0	235
hudakz	3:5b17e4656dd0	236	/* Macros. */
hudakz	3:5b17e4656dd0	237
hudakz	3:5b17e4656dd0	238	#define BUF ((struct uip_tcpip_hdr*) &uip_buf[UIP_LLH_LEN])
hudakz	3:5b17e4656dd0	239	#define FBUF ((struct uip_tcpip_hdr*) &uip_reassbuf[0])
hudakz	3:5b17e4656dd0	240	#define ICMPBUF ((struct uip_icmpip_hdr*) &uip_buf[UIP_LLH_LEN])
hudakz	3:5b17e4656dd0	241	#define UDPBUF ((struct uip_udpip_hdr*) &uip_buf[UIP_LLH_LEN])
hudakz	3:5b17e4656dd0	242	#if UIP_STATISTICS == 1
hudakz	3:5b17e4656dd0	243	struct uip_stats uip_stat;
hudakz	8:4acb22344932	244	#define UIP_STAT(s) s
hudakz	3:5b17e4656dd0	245	#else
hudakz	8:4acb22344932	246	#define UIP_STAT(s)
hudakz	3:5b17e4656dd0	247	#endif /* UIP_STATISTICS == 1 */
hudakz	3:5b17e4656dd0	248
hudakz	3:5b17e4656dd0	249	#if UIP_LOGGING == 1
hudakz	8:4acb22344932	250	#include <stdio.h>
hudakz	3:5b17e4656dd0	251	void uip_log(char* msg);
hudakz	8:4acb22344932	252	#define UIP_LOG(m) uip_log(m)
hudakz	3:5b17e4656dd0	253	#else
hudakz	8:4acb22344932	254	#define UIP_LOG(m)
hudakz	3:5b17e4656dd0	255	#endif /* UIP_LOGGING == 1 */
hudakz	3:5b17e4656dd0	256
hudakz	3:5b17e4656dd0	257	#if !UIP_ARCH_ADD32
hudakz	3:5b17e4656dd0	258
hudakz	3:5b17e4656dd0	259	/**
hudakz	3:5b17e4656dd0	260	* @brief
hudakz	3:5b17e4656dd0	261	* @note
hudakz	3:5b17e4656dd0	262	* @param
hudakz	3:5b17e4656dd0	263	* @retval
hudakz	3:5b17e4656dd0	264	*/
hudakz	3:5b17e4656dd0	265	void uip_add32(u8_t* op32, u16_t op16) {
hudakz	3:5b17e4656dd0	266	uip_acc32[3] = op32[3] + (op16 & 0xff);
hudakz	3:5b17e4656dd0	267	uip_acc32[2] = op32[2] + (op16 >> 8);
hudakz	3:5b17e4656dd0	268	uip_acc32[1] = op32[1];
hudakz	3:5b17e4656dd0	269	uip_acc32[0] = op32[0];
hudakz	3:5b17e4656dd0	270
hudakz	8:4acb22344932	271	if (uip_acc32[2] < (op16 >> 8)) {
hudakz	3:5b17e4656dd0	272	++uip_acc32[1];
hudakz	8:4acb22344932	273	if (uip_acc32[1] == 0) {
hudakz	3:5b17e4656dd0	274	++uip_acc32[0];
hudakz	3:5b17e4656dd0	275	}
hudakz	3:5b17e4656dd0	276	}
hudakz	3:5b17e4656dd0	277
hudakz	8:4acb22344932	278	if (uip_acc32[3] < (op16 & 0xff)) {
hudakz	3:5b17e4656dd0	279	++uip_acc32[2];
hudakz	8:4acb22344932	280	if (uip_acc32[2] == 0) {
hudakz	3:5b17e4656dd0	281	++uip_acc32[1];
hudakz	8:4acb22344932	282	if (uip_acc32[1] == 0) {
hudakz	3:5b17e4656dd0	283	++uip_acc32[0];
hudakz	3:5b17e4656dd0	284	}
hudakz	3:5b17e4656dd0	285	}
hudakz	3:5b17e4656dd0	286	}
hudakz	3:5b17e4656dd0	287	}
hudakz	3:5b17e4656dd0	288	#endif /* UIP_ARCH_ADD32 */
hudakz	3:5b17e4656dd0	289
hudakz	3:5b17e4656dd0	290	#if !UIP_ARCH_CHKSUM
hudakz	3:5b17e4656dd0	291
hudakz	3:5b17e4656dd0	292	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	293	static u16_t chksum(u16_t sum, const u8_t* data, u16_t len) {
hudakz	3:5b17e4656dd0	294	u16_t t;
hudakz	3:5b17e4656dd0	295	const u8_t* dataptr;
hudakz	3:5b17e4656dd0	296	const u8_t* last_byte;
hudakz	3:5b17e4656dd0	297
hudakz	3:5b17e4656dd0	298	dataptr = data;
hudakz	3:5b17e4656dd0	299	last_byte = data + len - 1;
hudakz	3:5b17e4656dd0	300
hudakz	8:4acb22344932	301	while (dataptr < last_byte) {
hudakz	3:5b17e4656dd0	302
hudakz	3:5b17e4656dd0	303	/* At least two more bytes */
hudakz	3:5b17e4656dd0	304	t = (dataptr[0] << 8) + dataptr[1];
hudakz	3:5b17e4656dd0	305	sum += t;
hudakz	8:4acb22344932	306	if (sum < t) {
hudakz	3:5b17e4656dd0	307	sum++; /* carry */
hudakz	3:5b17e4656dd0	308	}
hudakz	3:5b17e4656dd0	309
hudakz	3:5b17e4656dd0	310	dataptr += 2;
hudakz	3:5b17e4656dd0	311	}
hudakz	3:5b17e4656dd0	312
hudakz	8:4acb22344932	313	if (dataptr == last_byte) {
hudakz	3:5b17e4656dd0	314	t = (dataptr[0] << 8) + 0;
hudakz	3:5b17e4656dd0	315	sum += t;
hudakz	8:4acb22344932	316	if (sum < t) {
hudakz	3:5b17e4656dd0	317	sum++; /* carry */
hudakz	3:5b17e4656dd0	318	}
hudakz	3:5b17e4656dd0	319	}
hudakz	3:5b17e4656dd0	320
hudakz	3:5b17e4656dd0	321	/* Return sum in host byte order. */
hudakz	3:5b17e4656dd0	322	return sum;
hudakz	3:5b17e4656dd0	323	}
hudakz	3:5b17e4656dd0	324
hudakz	3:5b17e4656dd0	325	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	326	u16_t uip_chksum(u16_t* data, u16_t len) {
hudakz	3:5b17e4656dd0	327	return htons(chksum(0, (u8_t*)data, len));
hudakz	3:5b17e4656dd0	328	}
hudakz	3:5b17e4656dd0	329
hudakz	3:5b17e4656dd0	330	/---------------------------------------------------------------------------/
hudakz	8:4acb22344932	331	#ifndef UIP_ARCH_IPCHKSUM
hudakz	3:5b17e4656dd0	332
hudakz	3:5b17e4656dd0	333	/**
hudakz	3:5b17e4656dd0	334	* @brief
hudakz	3:5b17e4656dd0	335	* @note
hudakz	3:5b17e4656dd0	336	* @param
hudakz	3:5b17e4656dd0	337	* @retval
hudakz	3:5b17e4656dd0	338	*/
hudakz	3:5b17e4656dd0	339	u16_t uip_ipchksum(void) {
hudakz	3:5b17e4656dd0	340	u16_t sum;
hudakz	3:5b17e4656dd0	341
hudakz	3:5b17e4656dd0	342	sum = chksum(0, &uip_buf[UIP_LLH_LEN], UIP_IPH_LEN);
hudakz	3:5b17e4656dd0	343	DEBUG_PRINTF("uip_ipchksum: sum 0x%04x\n", sum);
hudakz	3:5b17e4656dd0	344	return(sum == 0) ? 0xffff : htons(sum);
hudakz	3:5b17e4656dd0	345	}
hudakz	8:4acb22344932	346	#endif
hudakz	3:5b17e4656dd0	347
hudakz	3:5b17e4656dd0	348	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	349	static u16_t upper_layer_chksum(u8_t proto) {
hudakz	3:5b17e4656dd0	350	u16_t upper_layer_len;
hudakz	3:5b17e4656dd0	351	u16_t sum;
hudakz	3:5b17e4656dd0	352
hudakz	8:4acb22344932	353	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	354	upper_layer_len = (((u16_t) (BUF->len[0]) << 8) + BUF->len[1]);
hudakz	8:4acb22344932	355	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	356	upper_layer_len = (((u16_t) (BUF->len[0]) << 8) + BUF->len[1]) - UIP_IPH_LEN;
hudakz	8:4acb22344932	357	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	358
hudakz	3:5b17e4656dd0	359	/* First sum pseudoheader. */
hudakz	3:5b17e4656dd0	360
hudakz	3:5b17e4656dd0	361	/* IP protocol and length fields. This addition cannot carry. */
hudakz	3:5b17e4656dd0	362	sum = upper_layer_len + proto;
hudakz	3:5b17e4656dd0	363
hudakz	3:5b17e4656dd0	364	/* Sum IP source and destination addresses. */
hudakz	3:5b17e4656dd0	365	sum = chksum(sum, (u8_t) &BUF->srcipaddr[0], 2 sizeof(uip_ipaddr_t));
hudakz	3:5b17e4656dd0	366
hudakz	3:5b17e4656dd0	367	/* Sum TCP header and data. */
hudakz	3:5b17e4656dd0	368	sum = chksum(sum, &uip_buf[UIP_IPH_LEN + UIP_LLH_LEN], upper_layer_len);
hudakz	3:5b17e4656dd0	369
hudakz	3:5b17e4656dd0	370	return(sum == 0) ? 0xffff : htons(sum);
hudakz	3:5b17e4656dd0	371	}
hudakz	3:5b17e4656dd0	372
hudakz	3:5b17e4656dd0	373	/---------------------------------------------------------------------------/
hudakz	8:4acb22344932	374	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	375
hudakz	3:5b17e4656dd0	376	/**
hudakz	3:5b17e4656dd0	377	* @brief
hudakz	3:5b17e4656dd0	378	* @note
hudakz	3:5b17e4656dd0	379	* @param
hudakz	3:5b17e4656dd0	380	* @retval
hudakz	3:5b17e4656dd0	381	*/
hudakz	3:5b17e4656dd0	382	u16_t uip_icmp6chksum(void) {
hudakz	3:5b17e4656dd0	383	return upper_layer_chksum(UIP_PROTO_ICMP6);
hudakz	3:5b17e4656dd0	384	}
hudakz	8:4acb22344932	385	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	386
hudakz	3:5b17e4656dd0	387	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	388	u16_t uip_tcpchksum(void) {
hudakz	3:5b17e4656dd0	389	return upper_layer_chksum(UIP_PROTO_TCP);
hudakz	3:5b17e4656dd0	390	}
hudakz	3:5b17e4656dd0	391
hudakz	3:5b17e4656dd0	392	/---------------------------------------------------------------------------/
hudakz	8:4acb22344932	393	#if UIP_UDP_CHECKSUMS
hudakz	3:5b17e4656dd0	394
hudakz	3:5b17e4656dd0	395	/**
hudakz	3:5b17e4656dd0	396	* @brief
hudakz	3:5b17e4656dd0	397	* @note
hudakz	3:5b17e4656dd0	398	* @param
hudakz	3:5b17e4656dd0	399	* @retval
hudakz	3:5b17e4656dd0	400	*/
hudakz	3:5b17e4656dd0	401	u16_t uip_udpchksum(void) {
hudakz	3:5b17e4656dd0	402	return upper_layer_chksum(UIP_PROTO_UDP);
hudakz	3:5b17e4656dd0	403	}
hudakz	8:4acb22344932	404	#endif /* UIP_UDP_CHECKSUMS */
hudakz	3:5b17e4656dd0	405	#endif /* UIP_ARCH_CHKSUM */
hudakz	3:5b17e4656dd0	406
hudakz	3:5b17e4656dd0	407	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	408	void uip_init(void) {
hudakz	8:4acb22344932	409	for (c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	3:5b17e4656dd0	410	uip_listenports[c] = 0;
hudakz	3:5b17e4656dd0	411	}
hudakz	3:5b17e4656dd0	412
hudakz	8:4acb22344932	413	for (c = 0; c < UIP_CONNS; ++c) {
hudakz	3:5b17e4656dd0	414	uip_conns[c].tcpstateflags = UIP_CLOSED;
hudakz	3:5b17e4656dd0	415	}
hudakz	3:5b17e4656dd0	416
hudakz	3:5b17e4656dd0	417	#if UIP_ACTIVE_OPEN
hudakz	3:5b17e4656dd0	418	lastport = 1024;
hudakz	3:5b17e4656dd0	419	#endif /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	420
hudakz	3:5b17e4656dd0	421	#if UIP_UDP
hudakz	8:4acb22344932	422	for (c = 0; c < UIP_UDP_CONNS; ++c) {
hudakz	3:5b17e4656dd0	423	uip_udp_conns[c].lport = 0;
hudakz	3:5b17e4656dd0	424	}
hudakz	3:5b17e4656dd0	425	#endif /* UIP_UDP */
hudakz	3:5b17e4656dd0	426
hudakz	3:5b17e4656dd0	427	/* IPv4 initialization. */
hudakz	3:5b17e4656dd0	428
hudakz	3:5b17e4656dd0	429	#if UIP_FIXEDADDR == 0
hudakz	3:5b17e4656dd0	430	/* uip_hostaddr[0] = uip_hostaddr[1] = 0;*/
hudakz	3:5b17e4656dd0	431	#endif /* UIP_FIXEDADDR */
hudakz	3:5b17e4656dd0	432	}
hudakz	3:5b17e4656dd0	433
hudakz	3:5b17e4656dd0	434	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	435	#if UIP_ACTIVE_OPEN
hudakz	3:5b17e4656dd0	436
hudakz	3:5b17e4656dd0	437	/**
hudakz	3:5b17e4656dd0	438	* @brief
hudakz	3:5b17e4656dd0	439	* @note
hudakz	3:5b17e4656dd0	440	* @param
hudakz	3:5b17e4656dd0	441	* @retval
hudakz	3:5b17e4656dd0	442	*/
hudakz	3:5b17e4656dd0	443	struct uip_conn* uip_connect(uip_ipaddr_t* ripaddr, u16_t rport) {
hudakz	3:5b17e4656dd0	444	register struct uip_conn* conn, *cconn;
hudakz	3:5b17e4656dd0	445
hudakz	3:5b17e4656dd0	446	/* Find an unused local port. */
hudakz	3:5b17e4656dd0	447
hudakz	3:5b17e4656dd0	448	again:
hudakz	3:5b17e4656dd0	449	++lastport;
hudakz	3:5b17e4656dd0	450
hudakz	8:4acb22344932	451	if (lastport >= 32000) {
hudakz	3:5b17e4656dd0	452	lastport = 4096;
hudakz	3:5b17e4656dd0	453	}
hudakz	3:5b17e4656dd0	454
hudakz	3:5b17e4656dd0	455	/* Check if this port is already in use, and if so try to find
hudakz	3:5b17e4656dd0	456	another one. */
hudakz	8:4acb22344932	457	for (c = 0; c < UIP_CONNS; ++c) {
hudakz	3:5b17e4656dd0	458	conn = &uip_conns[c];
hudakz	8:4acb22344932	459	if (conn->tcpstateflags != UIP_CLOSED && conn->lport == htons(lastport)) {
hudakz	3:5b17e4656dd0	460	goto again;
hudakz	3:5b17e4656dd0	461	}
hudakz	3:5b17e4656dd0	462	}
hudakz	3:5b17e4656dd0	463
hudakz	3:5b17e4656dd0	464	conn = 0;
hudakz	8:4acb22344932	465	for (c = 0; c < UIP_CONNS; ++c) {
hudakz	3:5b17e4656dd0	466	cconn = &uip_conns[c];
hudakz	8:4acb22344932	467	if (cconn->tcpstateflags == UIP_CLOSED) {
hudakz	3:5b17e4656dd0	468	conn = cconn;
hudakz	3:5b17e4656dd0	469	break;
hudakz	3:5b17e4656dd0	470	}
hudakz	3:5b17e4656dd0	471
hudakz	8:4acb22344932	472	if (cconn->tcpstateflags == UIP_TIME_WAIT) {
hudakz	8:4acb22344932	473	if (conn == 0 \|\| cconn->timer > conn->timer) {
hudakz	3:5b17e4656dd0	474	conn = cconn;
hudakz	3:5b17e4656dd0	475	}
hudakz	3:5b17e4656dd0	476	}
hudakz	3:5b17e4656dd0	477	}
hudakz	3:5b17e4656dd0	478
hudakz	8:4acb22344932	479	if (conn == 0) {
hudakz	3:5b17e4656dd0	480	return 0;
hudakz	3:5b17e4656dd0	481	}
hudakz	3:5b17e4656dd0	482
hudakz	3:5b17e4656dd0	483	conn->tcpstateflags = UIP_SYN_SENT;
hudakz	3:5b17e4656dd0	484
hudakz	3:5b17e4656dd0	485	conn->snd_nxt[0] = iss[0];
hudakz	3:5b17e4656dd0	486	conn->snd_nxt[1] = iss[1];
hudakz	3:5b17e4656dd0	487	conn->snd_nxt[2] = iss[2];
hudakz	3:5b17e4656dd0	488	conn->snd_nxt[3] = iss[3];
hudakz	3:5b17e4656dd0	489
hudakz	3:5b17e4656dd0	490	conn->initialmss = conn->mss = UIP_TCP_MSS;
hudakz	3:5b17e4656dd0	491
hudakz	3:5b17e4656dd0	492	conn->len = 1; /* TCP length of the SYN is one. */
hudakz	3:5b17e4656dd0	493	conn->nrtx = 0;
hudakz	3:5b17e4656dd0	494	conn->timer = 1; /* Send the SYN next time around. */
hudakz	3:5b17e4656dd0	495	conn->rto = UIP_RTO;
hudakz	3:5b17e4656dd0	496	conn->sa = 0;
hudakz	3:5b17e4656dd0	497	conn->sv = 16; /* Initial value of the RTT variance. */
hudakz	3:5b17e4656dd0	498	conn->lport = htons(lastport);
hudakz	3:5b17e4656dd0	499	conn->rport = rport;
hudakz	3:5b17e4656dd0	500	uip_ipaddr_copy(&conn->ripaddr, ripaddr);
hudakz	3:5b17e4656dd0	501
hudakz	3:5b17e4656dd0	502	return conn;
hudakz	3:5b17e4656dd0	503	}
hudakz	3:5b17e4656dd0	504	#endif /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	505
hudakz	3:5b17e4656dd0	506	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	507
hudakz	3:5b17e4656dd0	508	#if UIP_UDP
hudakz	3:5b17e4656dd0	509
hudakz	3:5b17e4656dd0	510	/**
hudakz	3:5b17e4656dd0	511	* @brief
hudakz	3:5b17e4656dd0	512	* @note
hudakz	3:5b17e4656dd0	513	* @param
hudakz	3:5b17e4656dd0	514	* @retval
hudakz	3:5b17e4656dd0	515	*/
hudakz	3:5b17e4656dd0	516	struct uip_udp_conn* uip_udp_new(uip_ipaddr_t* ripaddr, u16_t rport) {
hudakz	3:5b17e4656dd0	517	register struct uip_udp_conn* conn;
hudakz	3:5b17e4656dd0	518
hudakz	3:5b17e4656dd0	519	/* Find an unused local port. */
hudakz	3:5b17e4656dd0	520
hudakz	3:5b17e4656dd0	521	again:
hudakz	3:5b17e4656dd0	522	++lastport;
hudakz	3:5b17e4656dd0	523
hudakz	8:4acb22344932	524	if (lastport >= 32000) {
hudakz	3:5b17e4656dd0	525	lastport = 4096;
hudakz	3:5b17e4656dd0	526	}
hudakz	3:5b17e4656dd0	527
hudakz	8:4acb22344932	528	for (c = 0; c < UIP_UDP_CONNS; ++c) {
hudakz	8:4acb22344932	529	if (uip_udp_conns[c].lport == htons(lastport)) {
hudakz	3:5b17e4656dd0	530	goto again;
hudakz	3:5b17e4656dd0	531	}
hudakz	3:5b17e4656dd0	532	}
hudakz	3:5b17e4656dd0	533
hudakz	3:5b17e4656dd0	534	conn = 0;
hudakz	8:4acb22344932	535	for (c = 0; c < UIP_UDP_CONNS; ++c) {
hudakz	8:4acb22344932	536	if (uip_udp_conns[c].lport == 0) {
hudakz	3:5b17e4656dd0	537	conn = &uip_udp_conns[c];
hudakz	3:5b17e4656dd0	538	break;
hudakz	3:5b17e4656dd0	539	}
hudakz	3:5b17e4656dd0	540	}
hudakz	3:5b17e4656dd0	541
hudakz	8:4acb22344932	542	if (conn == 0) {
hudakz	3:5b17e4656dd0	543	return 0;
hudakz	3:5b17e4656dd0	544	}
hudakz	3:5b17e4656dd0	545
hudakz	3:5b17e4656dd0	546	conn->lport = HTONS(lastport);
hudakz	3:5b17e4656dd0	547	conn->rport = rport;
hudakz	8:4acb22344932	548	if (ripaddr == NULL) {
hudakz	3:5b17e4656dd0	549	memset(conn->ripaddr, 0, sizeof(uip_ipaddr_t));
hudakz	3:5b17e4656dd0	550	}
hudakz	3:5b17e4656dd0	551	else {
hudakz	3:5b17e4656dd0	552	uip_ipaddr_copy(&conn->ripaddr, ripaddr);
hudakz	3:5b17e4656dd0	553	}
hudakz	3:5b17e4656dd0	554
hudakz	3:5b17e4656dd0	555	conn->ttl = UIP_TTL;
hudakz	3:5b17e4656dd0	556
hudakz	3:5b17e4656dd0	557	return conn;
hudakz	3:5b17e4656dd0	558	}
hudakz	3:5b17e4656dd0	559	#endif /* UIP_UDP */
hudakz	3:5b17e4656dd0	560
hudakz	3:5b17e4656dd0	561	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	562	void uip_unlisten(u16_t port) {
hudakz	8:4acb22344932	563	for (c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	8:4acb22344932	564	if (uip_listenports[c] == port) {
hudakz	3:5b17e4656dd0	565	uip_listenports[c] = 0;
hudakz	3:5b17e4656dd0	566	return;
hudakz	3:5b17e4656dd0	567	}
hudakz	3:5b17e4656dd0	568	}
hudakz	3:5b17e4656dd0	569	}
hudakz	3:5b17e4656dd0	570
hudakz	3:5b17e4656dd0	571	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	572	void uip_listen(u16_t port) {
hudakz	8:4acb22344932	573	for (c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	8:4acb22344932	574	if (uip_listenports[c] == 0) {
hudakz	3:5b17e4656dd0	575	uip_listenports[c] = port;
hudakz	3:5b17e4656dd0	576	return;
hudakz	3:5b17e4656dd0	577	}
hudakz	3:5b17e4656dd0	578	}
hudakz	3:5b17e4656dd0	579	}
hudakz	3:5b17e4656dd0	580
hudakz	3:5b17e4656dd0	581	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	582	/* XXX: IP fragment reassembly: not well-tested. */
hudakz	3:5b17e4656dd0	583	#if UIP_REASSEMBLY && !UIP_CONF_IPV6
hudakz	8:4acb22344932	584	#define UIP_REASS_BUFSIZE (UIP_BUFSIZE - UIP_LLH_LEN)
hudakz	3:5b17e4656dd0	585	static u8_t uip_reassbuf[UIP_REASS_BUFSIZE];
hudakz	3:5b17e4656dd0	586	static u8_t uip_reassbitmap[UIP_REASS_BUFSIZE / (8 * 8)];
hudakz	3:5b17e4656dd0	587	static const u8_t bitmap_bits[8] = { 0xff, 0x7f, 0x3f, 0x1f, 0x0f, 0x07, 0x03, 0x01 };
hudakz	3:5b17e4656dd0	588	static u16_t uip_reasslen;
hudakz	3:5b17e4656dd0	589	static u8_t uip_reassflags;
hudakz	8:4acb22344932	590	#define UIP_REASS_FLAG_LASTFRAG 0x01
hudakz	3:5b17e4656dd0	591	static u8_t uip_reasstmr;
hudakz	3:5b17e4656dd0	592
hudakz	8:4acb22344932	593	#define IP_MF 0x20
hudakz	3:5b17e4656dd0	594
hudakz	3:5b17e4656dd0	595	/**
hudakz	3:5b17e4656dd0	596	* @brief
hudakz	3:5b17e4656dd0	597	* @note
hudakz	3:5b17e4656dd0	598	* @param
hudakz	3:5b17e4656dd0	599	* @retval
hudakz	3:5b17e4656dd0	600	*/
hudakz	3:5b17e4656dd0	601	static u8_t uip_reass(void) {
hudakz	3:5b17e4656dd0	602	u16_t offset, len;
hudakz	3:5b17e4656dd0	603	u16_t i;
hudakz	3:5b17e4656dd0	604
hudakz	3:5b17e4656dd0	605	/* If ip_reasstmr is zero, no packet is present in the buffer, so we
hudakz	3:5b17e4656dd0	606	write the IP header of the fragment into the reassembly
hudakz	3:5b17e4656dd0	607	buffer. The timer is updated with the maximum age. */
hudakz	3:5b17e4656dd0	608
hudakz	8:4acb22344932	609	if (uip_reasstmr == 0) {
hudakz	3:5b17e4656dd0	610	memcpy(uip_reassbuf, &BUF->vhl, UIP_IPH_LEN);
hudakz	3:5b17e4656dd0	611	uip_reasstmr = UIP_REASS_MAXAGE;
hudakz	3:5b17e4656dd0	612	uip_reassflags = 0;
hudakz	3:5b17e4656dd0	613
hudakz	3:5b17e4656dd0	614	/* Clear the bitmap. */
hudakz	3:5b17e4656dd0	615	memset(uip_reassbitmap, 0, sizeof(uip_reassbitmap));
hudakz	3:5b17e4656dd0	616	}
hudakz	3:5b17e4656dd0	617
hudakz	3:5b17e4656dd0	618	/* Check if the incoming fragment matches the one currently present
hudakz	3:5b17e4656dd0	619	in the reasembly buffer. If so, we proceed with copying the
hudakz	3:5b17e4656dd0	620	fragment into the buffer. */
hudakz	3:5b17e4656dd0	621	if
hudakz	3:5b17e4656dd0	622	(
hudakz	3:5b17e4656dd0	623	BUF->srcipaddr[0] == FBUF->srcipaddr[0]
hudakz	3:5b17e4656dd0	624	&& BUF->srcipaddr[1] == FBUF->srcipaddr[1]
hudakz	3:5b17e4656dd0	625	&& BUF->destipaddr[0] == FBUF->destipaddr[0]
hudakz	3:5b17e4656dd0	626	&& BUF->destipaddr[1] == FBUF->destipaddr[1]
hudakz	3:5b17e4656dd0	627	&& BUF->ipid[0] == FBUF->ipid[0]
hudakz	3:5b17e4656dd0	628	&& BUF->ipid[1] == FBUF->ipid[1]
hudakz	3:5b17e4656dd0	629	) {
hudakz	3:5b17e4656dd0	630	len = (BUF->len[0] << 8) + BUF->len[1] - (BUF->vhl & 0x0f) * 4;
hudakz	3:5b17e4656dd0	631	offset = (((BUF->ipoffset[0] & 0x3f) << 8) + BUF->ipoffset[1]) * 8;
hudakz	3:5b17e4656dd0	632
hudakz	3:5b17e4656dd0	633	/* If the offset or the offset + fragment length overflows the
hudakz	3:5b17e4656dd0	634	reassembly buffer, we discard the entire packet. */
hudakz	8:4acb22344932	635	if (offset > UIP_REASS_BUFSIZE \|\| offset + len > UIP_REASS_BUFSIZE) {
hudakz	3:5b17e4656dd0	636	uip_reasstmr = 0;
hudakz	3:5b17e4656dd0	637	goto nullreturn;
hudakz	3:5b17e4656dd0	638	}
hudakz	3:5b17e4656dd0	639
hudakz	3:5b17e4656dd0	640	/* Copy the fragment into the reassembly buffer, at the right
hudakz	3:5b17e4656dd0	641	offset. */
hudakz	3:5b17e4656dd0	642	memcpy(&uip_reassbuf[UIP_IPH_LEN + offset], (char)BUF + (int)((BUF->vhl & 0x0f) 4), len);
hudakz	3:5b17e4656dd0	643
hudakz	3:5b17e4656dd0	644	/* Update the bitmap. */
hudakz	8:4acb22344932	645	if (offset / (8 * 8) == (offset + len) / (8 * 8)) {
hudakz	3:5b17e4656dd0	646
hudakz	3:5b17e4656dd0	647	/* If the two endpoints are in the same byte, we only update
hudakz	4:d774541a34da	648	that byte. */
hudakz	3:5b17e4656dd0	649	uip_reassbitmap[offset / (8 * 8)] \|= bitmap_bits[(offset / 8) & 7] &~bitmap_bits[((offset + len) / 8) & 7];
hudakz	3:5b17e4656dd0	650	}
hudakz	3:5b17e4656dd0	651	else {
hudakz	3:5b17e4656dd0	652
hudakz	3:5b17e4656dd0	653	/* If the two endpoints are in different bytes, we update the
hudakz	4:d774541a34da	654	bytes in the endpoints and fill the stuff inbetween with
hudakz	4:d774541a34da	655	0xff. */
hudakz	3:5b17e4656dd0	656	uip_reassbitmap[offset / (8 * 8)] \|= bitmap_bits[(offset / 8) & 7];
hudakz	8:4acb22344932	657	for (i = 1 + offset / (8 * 8); i < (offset + len) / (8 * 8); ++i) {
hudakz	3:5b17e4656dd0	658	uip_reassbitmap[i] = 0xff;
hudakz	3:5b17e4656dd0	659	}
hudakz	3:5b17e4656dd0	660
hudakz	3:5b17e4656dd0	661	uip_reassbitmap[(offset + len) / (8 * 8)] \|= ~bitmap_bits[((offset + len) / 8) & 7];
hudakz	3:5b17e4656dd0	662	}
hudakz	3:5b17e4656dd0	663
hudakz	3:5b17e4656dd0	664	/* If this fragment has the More Fragments flag set to zero, we
hudakz	3:5b17e4656dd0	665	know that this is the last fragment, so we can calculate the
hudakz	3:5b17e4656dd0	666	size of the entire packet. We also set the
hudakz	3:5b17e4656dd0	667	IP_REASS_FLAG_LASTFRAG flag to indicate that we have received
hudakz	3:5b17e4656dd0	668	the final fragment. */
hudakz	8:4acb22344932	669	if ((BUF->ipoffset[0] & IP_MF) == 0) {
hudakz	3:5b17e4656dd0	670	uip_reassflags \|= UIP_REASS_FLAG_LASTFRAG;
hudakz	3:5b17e4656dd0	671	uip_reasslen = offset + len;
hudakz	3:5b17e4656dd0	672	}
hudakz	3:5b17e4656dd0	673
hudakz	3:5b17e4656dd0	674	/* Finally, we check if we have a full packet in the buffer. We do
hudakz	3:5b17e4656dd0	675	this by checking if we have the last fragment and if all bits
hudakz	3:5b17e4656dd0	676	in the bitmap are set. */
hudakz	8:4acb22344932	677	if (uip_reassflags & UIP_REASS_FLAG_LASTFRAG) {
hudakz	3:5b17e4656dd0	678
hudakz	3:5b17e4656dd0	679	/* Check all bytes up to and including all but the last byte in
hudakz	4:d774541a34da	680	the bitmap. */
hudakz	8:4acb22344932	681	for (i = 0; i < uip_reasslen / (8 * 8) - 1; ++i) {
hudakz	8:4acb22344932	682	if (uip_reassbitmap[i] != 0xff) {
hudakz	3:5b17e4656dd0	683	goto nullreturn;
hudakz	3:5b17e4656dd0	684	}
hudakz	3:5b17e4656dd0	685	}
hudakz	3:5b17e4656dd0	686
hudakz	3:5b17e4656dd0	687	/* Check the last byte in the bitmap. It should contain just the
hudakz	4:d774541a34da	688	right amount of bits. */
hudakz	8:4acb22344932	689	if (uip_reassbitmap[uip_reasslen / (8 * 8)] != (u8_t)~bitmap_bits[uip_reasslen / 8 & 7]) {
hudakz	3:5b17e4656dd0	690	goto nullreturn;
hudakz	3:5b17e4656dd0	691	}
hudakz	3:5b17e4656dd0	692
hudakz	3:5b17e4656dd0	693	/* If we have come this far, we have a full packet in the
hudakz	4:d774541a34da	694	buffer, so we allocate a pbuf and copy the packet into it. We
hudakz	4:d774541a34da	695	also reset the timer. */
hudakz	3:5b17e4656dd0	696	uip_reasstmr = 0;
hudakz	3:5b17e4656dd0	697	memcpy(BUF, FBUF, uip_reasslen);
hudakz	3:5b17e4656dd0	698
hudakz	3:5b17e4656dd0	699	/* Pretend to be a "normal" (i.e., not fragmented) IP packet
hudakz	4:d774541a34da	700	from now on. */
hudakz	3:5b17e4656dd0	701	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
hudakz	3:5b17e4656dd0	702	BUF->len[0] = uip_reasslen >> 8;
hudakz	3:5b17e4656dd0	703	BUF->len[1] = uip_reasslen & 0xff;
hudakz	3:5b17e4656dd0	704	BUF->ipchksum = 0;
hudakz	3:5b17e4656dd0	705	BUF->ipchksum = ~(uip_ipchksum());
hudakz	3:5b17e4656dd0	706
hudakz	3:5b17e4656dd0	707	return uip_reasslen;
hudakz	3:5b17e4656dd0	708	}
hudakz	3:5b17e4656dd0	709	}
hudakz	3:5b17e4656dd0	710
hudakz	3:5b17e4656dd0	711	nullreturn:
hudakz	3:5b17e4656dd0	712	return 0;
hudakz	3:5b17e4656dd0	713	}
hudakz	3:5b17e4656dd0	714	#endif /* UIP_REASSEMBLY */
hudakz	3:5b17e4656dd0	715
hudakz	3:5b17e4656dd0	716	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	717	static void uip_add_rcv_nxt(u16_t n) {
hudakz	3:5b17e4656dd0	718	uip_add32(uip_conn->rcv_nxt, n);
hudakz	3:5b17e4656dd0	719	uip_conn->rcv_nxt[0] = uip_acc32[0];
hudakz	3:5b17e4656dd0	720	uip_conn->rcv_nxt[1] = uip_acc32[1];
hudakz	3:5b17e4656dd0	721	uip_conn->rcv_nxt[2] = uip_acc32[2];
hudakz	3:5b17e4656dd0	722	uip_conn->rcv_nxt[3] = uip_acc32[3];
hudakz	3:5b17e4656dd0	723	}
hudakz	3:5b17e4656dd0	724
hudakz	3:5b17e4656dd0	725	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	726	void uip_process(u8_t flag) {
hudakz	3:5b17e4656dd0	727	register struct uip_conn* uip_connr = uip_conn;
hudakz	3:5b17e4656dd0	728
hudakz	3:5b17e4656dd0	729	#if UIP_UDP
hudakz	8:4acb22344932	730	if (flag == UIP_UDP_SEND_CONN) {
hudakz	3:5b17e4656dd0	731	goto udp_send;
hudakz	3:5b17e4656dd0	732	}
hudakz	3:5b17e4656dd0	733	#endif /* UIP_UDP */
hudakz	3:5b17e4656dd0	734
hudakz	3:5b17e4656dd0	735	uip_sappdata = uip_appdata = &uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN];
hudakz	3:5b17e4656dd0	736
hudakz	3:5b17e4656dd0	737	/* Check if we were invoked because of a poll request for a
hudakz	3:5b17e4656dd0	738	particular connection. */
hudakz	8:4acb22344932	739	if (flag == UIP_POLL_REQUEST) {
hudakz	8:4acb22344932	740	if ((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED && !uip_outstanding(uip_connr)) {
hudakz	3:5b17e4656dd0	741	uip_flags = UIP_POLL;
hudakz	3:5b17e4656dd0	742	UIP_APPCALL();
hudakz	3:5b17e4656dd0	743	goto appsend;
hudakz	3:5b17e4656dd0	744	}
hudakz	3:5b17e4656dd0	745
hudakz	3:5b17e4656dd0	746	goto drop;
hudakz	3:5b17e4656dd0	747
hudakz	3:5b17e4656dd0	748	/* Check if we were invoked because of the perodic timer fireing. */
hudakz	3:5b17e4656dd0	749	}
hudakz	3:5b17e4656dd0	750	else
hudakz	8:4acb22344932	751	if (flag == UIP_TIMER)
hudakz	3:5b17e4656dd0	752	{
hudakz	3:5b17e4656dd0	753	#if UIP_REASSEMBLY
hudakz	8:4acb22344932	754	if (uip_reasstmr != 0) {
hudakz	3:5b17e4656dd0	755	--uip_reasstmr;
hudakz	3:5b17e4656dd0	756	}
hudakz	3:5b17e4656dd0	757	#endif /* UIP_REASSEMBLY */
hudakz	3:5b17e4656dd0	758
hudakz	3:5b17e4656dd0	759	/* Increase the initial sequence number. */
hudakz	3:5b17e4656dd0	760
hudakz	8:4acb22344932	761	if (++iss[3] == 0) {
hudakz	8:4acb22344932	762	if (++iss[2] == 0) {
hudakz	8:4acb22344932	763	if (++iss[1] == 0) {
hudakz	3:5b17e4656dd0	764	++iss[0];
hudakz	3:5b17e4656dd0	765	}
hudakz	3:5b17e4656dd0	766	}
hudakz	3:5b17e4656dd0	767	}
hudakz	3:5b17e4656dd0	768
hudakz	3:5b17e4656dd0	769	/* Reset the length variables. */
hudakz	3:5b17e4656dd0	770	uip_len = 0;
hudakz	3:5b17e4656dd0	771	uip_slen = 0;
hudakz	3:5b17e4656dd0	772
hudakz	3:5b17e4656dd0	773	/* Check if the connection is in a state in which we simply wait
hudakz	3:5b17e4656dd0	774	for the connection to time out. If so, we increase the
hudakz	3:5b17e4656dd0	775	connection's timer and remove the connection if it times
hudakz	3:5b17e4656dd0	776	out. */
hudakz	8:4acb22344932	777	if (uip_connr->tcpstateflags == UIP_TIME_WAIT \|\| uip_connr->tcpstateflags == UIP_FIN_WAIT_2) {
hudakz	3:5b17e4656dd0	778	++(uip_connr->timer);
hudakz	8:4acb22344932	779	if (uip_connr->timer == UIP_TIME_WAIT_TIMEOUT) {
hudakz	3:5b17e4656dd0	780	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	3:5b17e4656dd0	781	}
hudakz	3:5b17e4656dd0	782	}
hudakz	3:5b17e4656dd0	783	else
hudakz	8:4acb22344932	784	if (uip_connr->tcpstateflags != UIP_CLOSED) {
hudakz	3:5b17e4656dd0	785
hudakz	3:5b17e4656dd0	786	/* If the connection has outstanding data, we increase the
hudakz	4:d774541a34da	787	connection's timer and see if it has reached the RTO value
hudakz	4:d774541a34da	788	in which case we retransmit. */
hudakz	8:4acb22344932	789	if (uip_outstanding(uip_connr)) {
hudakz	8:4acb22344932	790	if (uip_connr->timer-- == 0) {
hudakz	3:5b17e4656dd0	791	if
hudakz	3:5b17e4656dd0	792	(
hudakz	3:5b17e4656dd0	793	uip_connr->nrtx == UIP_MAXRTX
hudakz	3:5b17e4656dd0	794	\|\| (
hudakz	3:5b17e4656dd0	795	(uip_connr->tcpstateflags == UIP_SYN_SENT \|\| uip_connr->tcpstateflags == UIP_SYN_RCVD)
hudakz	3:5b17e4656dd0	796	&& uip_connr->nrtx == UIP_MAXSYNRTX
hudakz	3:5b17e4656dd0	797	)
hudakz	3:5b17e4656dd0	798	) {
hudakz	3:5b17e4656dd0	799	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	3:5b17e4656dd0	800
hudakz	3:5b17e4656dd0	801	/* We call UIP_APPCALL() with uip_flags set to
hudakz	4:d774541a34da	802	UIP_TIMEDOUT to inform the application that the
hudakz	4:d774541a34da	803	connection has timed out. */
hudakz	3:5b17e4656dd0	804	uip_flags = UIP_TIMEDOUT;
hudakz	3:5b17e4656dd0	805	UIP_APPCALL();
hudakz	3:5b17e4656dd0	806
hudakz	3:5b17e4656dd0	807	/* We also send a reset packet to the remote host. */
hudakz	3:5b17e4656dd0	808	BUF->flags = TCP_RST \| TCP_ACK;
hudakz	3:5b17e4656dd0	809	goto tcp_send_nodata;
hudakz	3:5b17e4656dd0	810	}
hudakz	3:5b17e4656dd0	811
hudakz	3:5b17e4656dd0	812	/* Exponential backoff. */
hudakz	3:5b17e4656dd0	813	uip_connr->timer = UIP_RTO << (uip_connr->nrtx > 4 ? 4 : uip_connr->nrtx);
hudakz	3:5b17e4656dd0	814	++(uip_connr->nrtx);
hudakz	3:5b17e4656dd0	815
hudakz	3:5b17e4656dd0	816	/* Ok, so we need to retransmit. We do this differently
hudakz	4:d774541a34da	817	depending on which state we are in. In ESTABLISHED, we
hudakz	4:d774541a34da	818	call upon the application so that it may prepare the
hudakz	4:d774541a34da	819	data for the retransmit. In SYN_RCVD, we resend the
hudakz	4:d774541a34da	820	SYNACK that we sent earlier and in LAST_ACK we have to
hudakz	4:d774541a34da	821	retransmit our FINACK. */
hudakz	3:5b17e4656dd0	822	UIP_STAT(++uip_stat.tcp.rexmit);
hudakz	8:4acb22344932	823	switch (uip_connr->tcpstateflags & UIP_TS_MASK) {
hudakz	8:4acb22344932	824	case UIP_SYN_RCVD:
hudakz	8:4acb22344932	825	/* In the SYN_RCVD state, we should retransmit our
hudakz	3:5b17e4656dd0	826	SYNACK. */
hudakz	8:4acb22344932	827	goto tcp_send_synack;
hudakz	3:5b17e4656dd0	828
hudakz	8:4acb22344932	829	#if UIP_ACTIVE_OPEN
hudakz	3:5b17e4656dd0	830
hudakz	8:4acb22344932	831	case UIP_SYN_SENT:
hudakz	8:4acb22344932	832	/* In the SYN_SENT state, we retransmit out SYN. */
hudakz	8:4acb22344932	833	BUF->flags = 0;
hudakz	8:4acb22344932	834	goto tcp_send_syn;
hudakz	8:4acb22344932	835	#endif /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	836
hudakz	8:4acb22344932	837	case UIP_ESTABLISHED:
hudakz	8:4acb22344932	838	/* In the ESTABLISHED state, we call upon the application
hudakz	3:5b17e4656dd0	839	to do the actual retransmit after which we jump into
hudakz	3:5b17e4656dd0	840	the code for sending out the packet (the apprexmit
hudakz	3:5b17e4656dd0	841	label). */
hudakz	8:4acb22344932	842	uip_flags = UIP_REXMIT;
hudakz	8:4acb22344932	843	UIP_APPCALL();
hudakz	8:4acb22344932	844	goto apprexmit;
hudakz	3:5b17e4656dd0	845
hudakz	8:4acb22344932	846	case UIP_FIN_WAIT_1:
hudakz	8:4acb22344932	847	case UIP_CLOSING:
hudakz	8:4acb22344932	848	case UIP_LAST_ACK:
hudakz	8:4acb22344932	849	/* In all these states we should retransmit a FINACK. */
hudakz	8:4acb22344932	850	goto tcp_send_finack;
hudakz	3:5b17e4656dd0	851	}
hudakz	3:5b17e4656dd0	852	}
hudakz	3:5b17e4656dd0	853	}
hudakz	3:5b17e4656dd0	854	else
hudakz	8:4acb22344932	855	if ((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_ESTABLISHED) {
hudakz	3:5b17e4656dd0	856
hudakz	3:5b17e4656dd0	857	/* If there was no need for a retransmission, we poll the
hudakz	3:5b17e4656dd0	858	application for new data. */
hudakz	3:5b17e4656dd0	859	uip_flags = UIP_POLL;
hudakz	3:5b17e4656dd0	860	UIP_APPCALL();
hudakz	3:5b17e4656dd0	861	goto appsend;
hudakz	3:5b17e4656dd0	862	}
hudakz	3:5b17e4656dd0	863	}
hudakz	3:5b17e4656dd0	864
hudakz	3:5b17e4656dd0	865	goto drop;
hudakz	3:5b17e4656dd0	866	}
hudakz	3:5b17e4656dd0	867
hudakz	3:5b17e4656dd0	868	#if UIP_UDP
hudakz	8:4acb22344932	869	if (flag == UIP_UDP_TIMER) {
hudakz	8:4acb22344932	870	if (uip_udp_conn->lport != 0) {
hudakz	3:5b17e4656dd0	871	uip_conn = NULL;
hudakz	3:5b17e4656dd0	872	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
hudakz	3:5b17e4656dd0	873	uip_len = uip_slen = 0;
hudakz	3:5b17e4656dd0	874	uip_flags = UIP_POLL;
hudakz	3:5b17e4656dd0	875	UIP_UDP_APPCALL();
hudakz	3:5b17e4656dd0	876	goto udp_send;
hudakz	3:5b17e4656dd0	877	}
hudakz	3:5b17e4656dd0	878	else {
hudakz	3:5b17e4656dd0	879	goto drop;
hudakz	3:5b17e4656dd0	880	}
hudakz	3:5b17e4656dd0	881	}
hudakz	3:5b17e4656dd0	882	#endif
hudakz	3:5b17e4656dd0	883	/* This is where the input processing starts. */
hudakz	3:5b17e4656dd0	884
hudakz	3:5b17e4656dd0	885	UIP_STAT(++uip_stat.ip.recv);
hudakz	3:5b17e4656dd0	886
hudakz	3:5b17e4656dd0	887	/* Start of IP input header processing code. */
hudakz	3:5b17e4656dd0	888	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	889	/* Check validity of the IP header. */
hudakz	3:5b17e4656dd0	890
hudakz	8:4acb22344932	891	if ((BUF->vtc & 0xf0) != 0x60) {
hudakz	3:5b17e4656dd0	892
hudakz	3:5b17e4656dd0	893	/* IP version and header length. */
hudakz	3:5b17e4656dd0	894	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	895	UIP_STAT(++uip_stat.ip.vhlerr);
hudakz	3:5b17e4656dd0	896	UIP_LOG("ipv6: invalid version.");
hudakz	3:5b17e4656dd0	897	goto drop;
hudakz	3:5b17e4656dd0	898	}
hudakz	3:5b17e4656dd0	899
hudakz	3:5b17e4656dd0	900	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	901	/* Check validity of the IP header. */
hudakz	3:5b17e4656dd0	902
hudakz	8:4acb22344932	903	if (BUF->vhl != 0x45) {
hudakz	3:5b17e4656dd0	904
hudakz	3:5b17e4656dd0	905	/* IP version and header length. */
hudakz	3:5b17e4656dd0	906	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	907	UIP_STAT(++uip_stat.ip.vhlerr);
hudakz	3:5b17e4656dd0	908	UIP_LOG("ip: invalid version or header length.");
hudakz	3:5b17e4656dd0	909	goto drop;
hudakz	3:5b17e4656dd0	910	}
hudakz	3:5b17e4656dd0	911	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	912
hudakz	3:5b17e4656dd0	913	/* Check the size of the packet. If the size reported to us in
hudakz	3:5b17e4656dd0	914	uip_len is smaller the size reported in the IP header, we assume
hudakz	3:5b17e4656dd0	915	that the packet has been corrupted in transit. If the size of
hudakz	3:5b17e4656dd0	916	uip_len is larger than the size reported in the IP packet header,
hudakz	3:5b17e4656dd0	917	the packet has been padded and we set uip_len to the correct
hudakz	3:5b17e4656dd0	918	value.. */
hudakz	3:5b17e4656dd0	919
hudakz	8:4acb22344932	920	if ((BUF->len[0] << 8) + BUF->len[1] <= uip_len) {
hudakz	3:5b17e4656dd0	921	uip_len = (BUF->len[0] << 8) + BUF->len[1];
hudakz	3:5b17e4656dd0	922	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	923	uip_len += 40; /* The length reported in the IPv6 header is the
hudakz	4:d774541a34da	924	length of the payload that follows the
hudakz	8:4acb22344932	925	header. However, UIP uses the uip_len variable
hudakz	4:d774541a34da	926	for holding the size of the entire packet,
hudakz	4:d774541a34da	927	including the IP header. For IPv4 this is not a
hudakz	4:d774541a34da	928	problem as the length field in the IPv4 header
hudakz	4:d774541a34da	929	contains the length of the entire packet. But
hudakz	4:d774541a34da	930	for IPv6 we need to add the size of the IPv6
hudakz	4:d774541a34da	931	header (40 bytes). */
hudakz	3:5b17e4656dd0	932	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	933	}
hudakz	3:5b17e4656dd0	934	else {
hudakz	3:5b17e4656dd0	935	UIP_LOG("ip: packet shorter than reported in IP header.");
hudakz	3:5b17e4656dd0	936	goto drop;
hudakz	3:5b17e4656dd0	937	}
hudakz	3:5b17e4656dd0	938
hudakz	3:5b17e4656dd0	939	#if !UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	940	/* Check the fragment flag. */
hudakz	3:5b17e4656dd0	941
hudakz	8:4acb22344932	942	if ((BUF->ipoffset[0] & 0x3f) != 0 \|\| BUF->ipoffset[1] != 0)
hudakz	3:5b17e4656dd0	943	{
hudakz	8:4acb22344932	944	#if UIP_REASSEMBLY
hudakz	3:5b17e4656dd0	945	uip_len = uip_reass();
hudakz	8:4acb22344932	946	if (uip_len == 0) {
hudakz	3:5b17e4656dd0	947	goto drop;
hudakz	3:5b17e4656dd0	948	}
hudakz	3:5b17e4656dd0	949
hudakz	8:4acb22344932	950	#else /* UIP_REASSEMBLY */
hudakz	3:5b17e4656dd0	951	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	952	UIP_STAT(++uip_stat.ip.fragerr);
hudakz	3:5b17e4656dd0	953	UIP_LOG("ip: fragment dropped.");
hudakz	3:5b17e4656dd0	954	goto drop;
hudakz	8:4acb22344932	955	#endif /* UIP_REASSEMBLY */
hudakz	3:5b17e4656dd0	956	}
hudakz	3:5b17e4656dd0	957	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	958
hudakz	8:4acb22344932	959	if (uip_ipaddr_cmp(uip_hostaddr, all_zeroes_addr))
hudakz	3:5b17e4656dd0	960	{
hudakz	3:5b17e4656dd0	961	/* If we are configured to use ping IP address configuration and
hudakz	3:5b17e4656dd0	962	hasn't been assigned an IP address yet, we accept all ICMP
hudakz	3:5b17e4656dd0	963	packets. */
hudakz	3:5b17e4656dd0	964	#if UIP_PINGADDRCONF && !UIP_CONF_IPV6
hudakz	8:4acb22344932	965	if (BUF->proto == UIP_PROTO_ICMP) {
hudakz	3:5b17e4656dd0	966	UIP_LOG("ip: possible ping config packet received.");
hudakz	3:5b17e4656dd0	967	goto icmp_input;
hudakz	3:5b17e4656dd0	968	}
hudakz	3:5b17e4656dd0	969	else {
hudakz	3:5b17e4656dd0	970	UIP_LOG("ip: packet dropped since no address assigned.");
hudakz	3:5b17e4656dd0	971	goto drop;
hudakz	3:5b17e4656dd0	972	}
hudakz	3:5b17e4656dd0	973	#endif /* UIP_PINGADDRCONF */
hudakz	3:5b17e4656dd0	974	}
hudakz	3:5b17e4656dd0	975	else
hudakz	3:5b17e4656dd0	976	{
hudakz	3:5b17e4656dd0	977	/* If IP broadcast support is configured, we check for a broadcast
hudakz	3:5b17e4656dd0	978	UDP packet, which may be destined to us. */
hudakz	3:5b17e4656dd0	979	#if UIP_BROADCAST
hudakz	3:5b17e4656dd0	980	DEBUG_PRINTF("UDP IP checksum 0x%04x\n", uip_ipchksum());
hudakz	3:5b17e4656dd0	981	if
hudakz	3:5b17e4656dd0	982	(
hudakz	3:5b17e4656dd0	983	BUF->proto == UIP_PROTO_UDP
hudakz	3:5b17e4656dd0	984	&& uip_ipaddr_cmp(BUF->destipaddr, all_ones_addr) /*&&
hudakz	4:d774541a34da	985	uip_ipchksum() == 0xffff*/
hudakz	3:5b17e4656dd0	986	) {
hudakz	3:5b17e4656dd0	987	goto udp_input;
hudakz	3:5b17e4656dd0	988	}
hudakz	3:5b17e4656dd0	989	#endif /* UIP_BROADCAST */
hudakz	3:5b17e4656dd0	990
hudakz	3:5b17e4656dd0	991	/* Check if the packet is destined for our IP address. */
hudakz	3:5b17e4656dd0	992
hudakz	3:5b17e4656dd0	993	#if !UIP_CONF_IPV6
hudakz	8:4acb22344932	994	if (!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr)) {
hudakz	3:5b17e4656dd0	995	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	996	goto drop;
hudakz	3:5b17e4656dd0	997	}
hudakz	3:5b17e4656dd0	998
hudakz	3:5b17e4656dd0	999	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1000	/* For IPv6, packet reception is a little trickier as we need to
hudakz	3:5b17e4656dd0	1001	make sure that we listen to certain multicast addresses (all
hudakz	3:5b17e4656dd0	1002	hosts multicast address, and the solicited-node multicast
hudakz	3:5b17e4656dd0	1003	address) as well. However, we will cheat here and accept all
hudakz	3:5b17e4656dd0	1004	multicast packets that are sent to the ff02::/16 addresses. */
hudakz	3:5b17e4656dd0	1005
hudakz	8:4acb22344932	1006	if (!uip_ipaddr_cmp(BUF->destipaddr, uip_hostaddr) && BUF->destipaddr[0] != HTONS(0xff02)) {
hudakz	3:5b17e4656dd0	1007	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	1008	goto drop;
hudakz	3:5b17e4656dd0	1009	}
hudakz	3:5b17e4656dd0	1010	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1011	}
hudakz	3:5b17e4656dd0	1012
hudakz	3:5b17e4656dd0	1013	#if !UIP_CONF_IPV6
hudakz	8:4acb22344932	1014	if (uip_ipchksum() != 0xffff) {
hudakz	3:5b17e4656dd0	1015
hudakz	3:5b17e4656dd0	1016	/* Compute and check the IP header
hudakz	4:d774541a34da	1017	checksum. */
hudakz	3:5b17e4656dd0	1018	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	1019	UIP_STAT(++uip_stat.ip.chkerr);
hudakz	3:5b17e4656dd0	1020	UIP_LOG("ip: bad checksum.");
hudakz	3:5b17e4656dd0	1021	goto drop;
hudakz	3:5b17e4656dd0	1022	}
hudakz	3:5b17e4656dd0	1023	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1024
hudakz	8:4acb22344932	1025	if (BUF->proto == UIP_PROTO_TCP) {
hudakz	3:5b17e4656dd0	1026
hudakz	3:5b17e4656dd0	1027	/* Check for TCP packet. If so,
hudakz	4:d774541a34da	1028	proceed with TCP input
hudakz	4:d774541a34da	1029	processing. */
hudakz	3:5b17e4656dd0	1030	goto tcp_input;
hudakz	3:5b17e4656dd0	1031	}
hudakz	3:5b17e4656dd0	1032
hudakz	3:5b17e4656dd0	1033	#if UIP_UDP
hudakz	8:4acb22344932	1034	if (BUF->proto == UIP_PROTO_UDP) {
hudakz	3:5b17e4656dd0	1035	goto udp_input;
hudakz	3:5b17e4656dd0	1036	}
hudakz	3:5b17e4656dd0	1037	#endif /* UIP_UDP */
hudakz	3:5b17e4656dd0	1038
hudakz	3:5b17e4656dd0	1039	#if !UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	1040	/* ICMPv4 processing code follows. */
hudakz	3:5b17e4656dd0	1041
hudakz	8:4acb22344932	1042	if (BUF->proto != UIP_PROTO_ICMP) {
hudakz	3:5b17e4656dd0	1043
hudakz	3:5b17e4656dd0	1044	/* We only allow ICMP packets from
hudakz	4:d774541a34da	1045	here. */
hudakz	3:5b17e4656dd0	1046	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	1047	UIP_STAT(++uip_stat.ip.protoerr);
hudakz	3:5b17e4656dd0	1048	UIP_LOG("ip: neither tcp nor icmp.");
hudakz	3:5b17e4656dd0	1049	goto drop;
hudakz	3:5b17e4656dd0	1050	}
hudakz	3:5b17e4656dd0	1051
hudakz	8:4acb22344932	1052	#if UIP_PINGADDRCONF
hudakz	3:5b17e4656dd0	1053	icmp_input :
hudakz	8:4acb22344932	1054	#endif /* UIP_PINGADDRCONF */
hudakz	3:5b17e4656dd0	1055
hudakz	3:5b17e4656dd0	1056	UIP_STAT(++uip_stat.icmp.recv);
hudakz	3:5b17e4656dd0	1057
hudakz	3:5b17e4656dd0	1058	/* ICMP echo (i.e., ping) processing. This is simple, we only change
hudakz	3:5b17e4656dd0	1059	the ICMP type from ECHO to ECHO_REPLY and adjust the ICMP
hudakz	3:5b17e4656dd0	1060	checksum before we return the packet. */
hudakz	8:4acb22344932	1061	if (ICMPBUF->type != ICMP_ECHO) {
hudakz	3:5b17e4656dd0	1062	UIP_STAT(++uip_stat.icmp.drop);
hudakz	3:5b17e4656dd0	1063	UIP_STAT(++uip_stat.icmp.typeerr);
hudakz	3:5b17e4656dd0	1064	UIP_LOG("icmp: not icmp echo.");
hudakz	3:5b17e4656dd0	1065	goto drop;
hudakz	3:5b17e4656dd0	1066	}
hudakz	3:5b17e4656dd0	1067
hudakz	3:5b17e4656dd0	1068	/* If we are configured to use ping IP address assignment, we use
hudakz	3:5b17e4656dd0	1069	the destination IP address of this ping packet and assign it to
hudakz	3:5b17e4656dd0	1070	ourself. */
hudakz	8:4acb22344932	1071	#if UIP_PINGADDRCONF
hudakz	8:4acb22344932	1072	if ((uip_hostaddr[0] \| uip_hostaddr[1]) == 0) {
hudakz	3:5b17e4656dd0	1073	uip_hostaddr[0] = BUF->destipaddr[0];
hudakz	3:5b17e4656dd0	1074	uip_hostaddr[1] = BUF->destipaddr[1];
hudakz	3:5b17e4656dd0	1075	}
hudakz	8:4acb22344932	1076	#endif /* UIP_PINGADDRCONF */
hudakz	3:5b17e4656dd0	1077
hudakz	3:5b17e4656dd0	1078	ICMPBUF->type = ICMP_ECHO_REPLY;
hudakz	3:5b17e4656dd0	1079
hudakz	8:4acb22344932	1080	if (ICMPBUF->icmpchksum >= HTONS(0xffff - (ICMP_ECHO << 8))) {
hudakz	3:5b17e4656dd0	1081	ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8) + 1;
hudakz	3:5b17e4656dd0	1082	}
hudakz	3:5b17e4656dd0	1083	else {
hudakz	3:5b17e4656dd0	1084	ICMPBUF->icmpchksum += HTONS(ICMP_ECHO << 8);
hudakz	3:5b17e4656dd0	1085	}
hudakz	3:5b17e4656dd0	1086
hudakz	3:5b17e4656dd0	1087	/* Swap IP addresses. */
hudakz	3:5b17e4656dd0	1088	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
hudakz	3:5b17e4656dd0	1089	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	3:5b17e4656dd0	1090
hudakz	3:5b17e4656dd0	1091	UIP_STAT(++uip_stat.icmp.sent);
hudakz	3:5b17e4656dd0	1092	goto send;
hudakz	3:5b17e4656dd0	1093
hudakz	3:5b17e4656dd0	1094	/* End of IPv4 input header processing code. */
hudakz	3:5b17e4656dd0	1095	#else /* !UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1096	/* This is IPv6 ICMPv6 processing code. */
hudakz	3:5b17e4656dd0	1097
hudakz	3:5b17e4656dd0	1098	DEBUG_PRINTF("icmp6_input: length %d\n", uip_len);
hudakz	3:5b17e4656dd0	1099
hudakz	8:4acb22344932	1100	if (BUF->proto != UIP_PROTO_ICMP6) {
hudakz	3:5b17e4656dd0	1101
hudakz	3:5b17e4656dd0	1102	/* We only allow ICMPv6 packets from
hudakz	4:d774541a34da	1103	here. */
hudakz	3:5b17e4656dd0	1104	UIP_STAT(++uip_stat.ip.drop);
hudakz	3:5b17e4656dd0	1105	UIP_STAT(++uip_stat.ip.protoerr);
hudakz	3:5b17e4656dd0	1106	UIP_LOG("ip: neither tcp nor icmp6.");
hudakz	3:5b17e4656dd0	1107	goto drop;
hudakz	3:5b17e4656dd0	1108	}
hudakz	3:5b17e4656dd0	1109
hudakz	3:5b17e4656dd0	1110	UIP_STAT(++uip_stat.icmp.recv);
hudakz	3:5b17e4656dd0	1111
hudakz	3:5b17e4656dd0	1112	/* If we get a neighbor solicitation for our address we should send
hudakz	3:5b17e4656dd0	1113	a neighbor advertisement message back. */
hudakz	8:4acb22344932	1114	if (ICMPBUF->type == ICMP6_NEIGHBOR_SOLICITATION) {
hudakz	8:4acb22344932	1115	if (uip_ipaddr_cmp(ICMPBUF->icmp6data, uip_hostaddr)) {
hudakz	8:4acb22344932	1116	if (ICMPBUF->options[0] == ICMP6_OPTION_SOURCE_LINK_ADDRESS) {
hudakz	3:5b17e4656dd0	1117
hudakz	3:5b17e4656dd0	1118	/* Save the sender's address in our neighbor list. */
hudakz	3:5b17e4656dd0	1119	uip_neighbor_add(ICMPBUF->srcipaddr, &(ICMPBUF->options[2]));
hudakz	3:5b17e4656dd0	1120	}
hudakz	3:5b17e4656dd0	1121
hudakz	3:5b17e4656dd0	1122	/* We should now send a neighbor advertisement back to where the
hudakz	4:d774541a34da	1123	neighbor solicication came from. */
hudakz	3:5b17e4656dd0	1124	ICMPBUF->type = ICMP6_NEIGHBOR_ADVERTISEMENT;
hudakz	3:5b17e4656dd0	1125	ICMPBUF->flags = ICMP6_FLAG_S; /* Solicited flag. */
hudakz	3:5b17e4656dd0	1126
hudakz	3:5b17e4656dd0	1127	ICMPBUF->reserved1 = ICMPBUF->reserved2 = ICMPBUF->reserved3 = 0;
hudakz	3:5b17e4656dd0	1128
hudakz	3:5b17e4656dd0	1129	uip_ipaddr_copy(ICMPBUF->destipaddr, ICMPBUF->srcipaddr);
hudakz	3:5b17e4656dd0	1130	uip_ipaddr_copy(ICMPBUF->srcipaddr, uip_hostaddr);
hudakz	3:5b17e4656dd0	1131	ICMPBUF->options[0] = ICMP6_OPTION_TARGET_LINK_ADDRESS;
hudakz	3:5b17e4656dd0	1132	ICMPBUF->options[1] = 1; /* Options length, 1 = 8 bytes. */
hudakz	3:5b17e4656dd0	1133	memcpy(&(ICMPBUF->options[2]), &uip_ethaddr, sizeof(uip_ethaddr));
hudakz	3:5b17e4656dd0	1134	ICMPBUF->icmpchksum = 0;
hudakz	3:5b17e4656dd0	1135	ICMPBUF->icmpchksum = ~uip_icmp6chksum();
hudakz	3:5b17e4656dd0	1136	goto send;
hudakz	3:5b17e4656dd0	1137	}
hudakz	3:5b17e4656dd0	1138
hudakz	3:5b17e4656dd0	1139	goto drop;
hudakz	3:5b17e4656dd0	1140	}
hudakz	3:5b17e4656dd0	1141	else
hudakz	8:4acb22344932	1142	if (ICMPBUF->type == ICMP6_ECHO) {
hudakz	3:5b17e4656dd0	1143
hudakz	3:5b17e4656dd0	1144	/* ICMP echo (i.e., ping) processing. This is simple, we only
hudakz	3:5b17e4656dd0	1145	change the ICMP type from ECHO to ECHO_REPLY and update the
hudakz	3:5b17e4656dd0	1146	ICMP checksum before we return the packet. */
hudakz	3:5b17e4656dd0	1147	ICMPBUF->type = ICMP6_ECHO_REPLY;
hudakz	3:5b17e4656dd0	1148
hudakz	3:5b17e4656dd0	1149	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
hudakz	3:5b17e4656dd0	1150	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	3:5b17e4656dd0	1151	ICMPBUF->icmpchksum = 0;
hudakz	3:5b17e4656dd0	1152	ICMPBUF->icmpchksum = ~uip_icmp6chksum();
hudakz	3:5b17e4656dd0	1153
hudakz	3:5b17e4656dd0	1154	UIP_STAT(++uip_stat.icmp.sent);
hudakz	3:5b17e4656dd0	1155	goto send;
hudakz	3:5b17e4656dd0	1156	}
hudakz	3:5b17e4656dd0	1157	else {
hudakz	3:5b17e4656dd0	1158	DEBUG_PRINTF("Unknown icmp6 message type %d\n", ICMPBUF->type);
hudakz	3:5b17e4656dd0	1159	UIP_STAT(++uip_stat.icmp.drop);
hudakz	3:5b17e4656dd0	1160	UIP_STAT(++uip_stat.icmp.typeerr);
hudakz	3:5b17e4656dd0	1161	UIP_LOG("icmp: unknown ICMP message.");
hudakz	3:5b17e4656dd0	1162	goto drop;
hudakz	3:5b17e4656dd0	1163	}
hudakz	3:5b17e4656dd0	1164
hudakz	3:5b17e4656dd0	1165	/* End of IPv6 ICMP processing. */
hudakz	3:5b17e4656dd0	1166	#endif /* !UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1167
hudakz	3:5b17e4656dd0	1168	#if UIP_UDP
hudakz	3:5b17e4656dd0	1169	/* UDP input processing. */
hudakz	3:5b17e4656dd0	1170
hudakz	3:5b17e4656dd0	1171	udp_input :
hudakz	3:5b17e4656dd0	1172	/* UDP processing is really just a hack. We don't do anything to the
hudakz	3:5b17e4656dd0	1173	UDP/IP headers, but let the UDP application do all the hard
hudakz	3:5b17e4656dd0	1174	work. If the application sets uip_slen, it has a packet to
hudakz	3:5b17e4656dd0	1175	send. */
hudakz	8:4acb22344932	1176	#if UIP_UDP_CHECKSUMS
hudakz	3:5b17e4656dd0	1177	uip_len = uip_len - UIP_IPUDPH_LEN;
hudakz	3:5b17e4656dd0	1178	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
hudakz	8:4acb22344932	1179	if (UDPBUF->udpchksum != 0 && uip_udpchksum() != 0xffff) {
hudakz	3:5b17e4656dd0	1180	UIP_STAT(++uip_stat.udp.drop);
hudakz	3:5b17e4656dd0	1181	UIP_STAT(++uip_stat.udp.chkerr);
hudakz	3:5b17e4656dd0	1182	UIP_LOG("udp: bad checksum.");
hudakz	3:5b17e4656dd0	1183	goto drop;
hudakz	3:5b17e4656dd0	1184	}
hudakz	3:5b17e4656dd0	1185
hudakz	8:4acb22344932	1186	#else /* UIP_UDP_CHECKSUMS */
hudakz	3:5b17e4656dd0	1187	uip_len = uip_len - UIP_IPUDPH_LEN;
hudakz	8:4acb22344932	1188	#endif /* UIP_UDP_CHECKSUMS */
hudakz	3:5b17e4656dd0	1189
hudakz	3:5b17e4656dd0	1190	/* Demultiplex this UDP packet between the UDP "connections". */
hudakz	3:5b17e4656dd0	1191
hudakz	8:4acb22344932	1192	for (uip_udp_conn = &uip_udp_conns[0]; uip_udp_conn < &uip_udp_conns[UIP_UDP_CONNS]; ++uip_udp_conn) {
hudakz	3:5b17e4656dd0	1193
hudakz	3:5b17e4656dd0	1194	/* If the local UDP port is non-zero, the connection is considered
hudakz	3:5b17e4656dd0	1195	to be used. If so, the local port number is checked against the
hudakz	3:5b17e4656dd0	1196	destination port number in the received packet. If the two port
hudakz	3:5b17e4656dd0	1197	numbers match, the remote port number is checked if the
hudakz	3:5b17e4656dd0	1198	connection is bound to a remote port. Finally, if the
hudakz	3:5b17e4656dd0	1199	connection is bound to a remote IP address, the source IP
hudakz	3:5b17e4656dd0	1200	address of the packet is checked. */
hudakz	3:5b17e4656dd0	1201	if
hudakz	3:5b17e4656dd0	1202	(
hudakz	3:5b17e4656dd0	1203	uip_udp_conn->lport != 0
hudakz	3:5b17e4656dd0	1204	&& UDPBUF->destport == uip_udp_conn->lport
hudakz	3:5b17e4656dd0	1205	&& (uip_udp_conn->rport == 0 \|\| UDPBUF->srcport == uip_udp_conn->rport)
hudakz	3:5b17e4656dd0	1206	&& (
hudakz	3:5b17e4656dd0	1207	uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_zeroes_addr)
hudakz	3:5b17e4656dd0	1208	\|\| uip_ipaddr_cmp(uip_udp_conn->ripaddr, all_ones_addr)
hudakz	3:5b17e4656dd0	1209	\|\| uip_ipaddr_cmp(BUF->srcipaddr, uip_udp_conn->ripaddr)
hudakz	3:5b17e4656dd0	1210	)
hudakz	3:5b17e4656dd0	1211	) {
hudakz	3:5b17e4656dd0	1212	goto udp_found;
hudakz	3:5b17e4656dd0	1213	}
hudakz	3:5b17e4656dd0	1214	}
hudakz	3:5b17e4656dd0	1215
hudakz	3:5b17e4656dd0	1216	UIP_LOG("udp: no matching connection found");
hudakz	3:5b17e4656dd0	1217	goto drop;
hudakz	3:5b17e4656dd0	1218
hudakz	3:5b17e4656dd0	1219	udp_found:
hudakz	3:5b17e4656dd0	1220	uip_conn = NULL;
hudakz	3:5b17e4656dd0	1221	uip_flags = UIP_NEWDATA;
hudakz	3:5b17e4656dd0	1222	uip_sappdata = uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPUDPH_LEN];
hudakz	3:5b17e4656dd0	1223	uip_slen = 0;
hudakz	3:5b17e4656dd0	1224	UIP_UDP_APPCALL();
hudakz	3:5b17e4656dd0	1225	udp_send:
hudakz	8:4acb22344932	1226	if (uip_slen == 0) {
hudakz	3:5b17e4656dd0	1227	goto drop;
hudakz	3:5b17e4656dd0	1228	}
hudakz	3:5b17e4656dd0	1229
hudakz	3:5b17e4656dd0	1230	uip_len = uip_slen + UIP_IPUDPH_LEN;
hudakz	3:5b17e4656dd0	1231
hudakz	8:4acb22344932	1232	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	1233	/* For IPv6, the IP length field does not include the IPv6 IP header
hudakz	3:5b17e4656dd0	1234	length. */
hudakz	3:5b17e4656dd0	1235
hudakz	3:5b17e4656dd0	1236	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
hudakz	3:5b17e4656dd0	1237	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
hudakz	8:4acb22344932	1238	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1239	BUF->len[0] = (uip_len >> 8);
hudakz	3:5b17e4656dd0	1240	BUF->len[1] = (uip_len & 0xff);
hudakz	8:4acb22344932	1241	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	1242
hudakz	3:5b17e4656dd0	1243	BUF->ttl = uip_udp_conn->ttl;
hudakz	3:5b17e4656dd0	1244	BUF->proto = UIP_PROTO_UDP;
hudakz	3:5b17e4656dd0	1245
hudakz	3:5b17e4656dd0	1246	UDPBUF->udplen = HTONS(uip_slen + UIP_UDPH_LEN);
hudakz	3:5b17e4656dd0	1247	UDPBUF->udpchksum = 0;
hudakz	3:5b17e4656dd0	1248
hudakz	3:5b17e4656dd0	1249	BUF->srcport = uip_udp_conn->lport;
hudakz	3:5b17e4656dd0	1250	BUF->destport = uip_udp_conn->rport;
hudakz	3:5b17e4656dd0	1251
hudakz	3:5b17e4656dd0	1252	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	3:5b17e4656dd0	1253	uip_ipaddr_copy(BUF->destipaddr, uip_udp_conn->ripaddr);
hudakz	3:5b17e4656dd0	1254
hudakz	3:5b17e4656dd0	1255	uip_appdata = &uip_buf[UIP_LLH_LEN + UIP_IPTCPH_LEN];
hudakz	3:5b17e4656dd0	1256
hudakz	8:4acb22344932	1257	#if UIP_UDP_CHECKSUMS
hudakz	3:5b17e4656dd0	1258	/* Calculate UDP checksum. */
hudakz	3:5b17e4656dd0	1259
hudakz	3:5b17e4656dd0	1260	UDPBUF->udpchksum = ~(uip_udpchksum());
hudakz	8:4acb22344932	1261	if (UDPBUF->udpchksum == 0) {
hudakz	3:5b17e4656dd0	1262	UDPBUF->udpchksum = 0xffff;
hudakz	3:5b17e4656dd0	1263	}
hudakz	8:4acb22344932	1264	#endif /* UIP_UDP_CHECKSUMS */
hudakz	3:5b17e4656dd0	1265
hudakz	3:5b17e4656dd0	1266	goto ip_send_nolen;
hudakz	3:5b17e4656dd0	1267	#endif /* UIP_UDP */
hudakz	3:5b17e4656dd0	1268
hudakz	3:5b17e4656dd0	1269	/* TCP input processing. */
hudakz	3:5b17e4656dd0	1270
hudakz	3:5b17e4656dd0	1271	tcp_input : UIP_STAT(++uip_stat.tcp.recv);
hudakz	3:5b17e4656dd0	1272
hudakz	3:5b17e4656dd0	1273	/* Start of TCP input header processing code. */
hudakz	8:4acb22344932	1274	if (uip_tcpchksum() != 0xffff) {
hudakz	3:5b17e4656dd0	1275
hudakz	3:5b17e4656dd0	1276	/* Compute and check the TCP
hudakz	4:d774541a34da	1277	checksum. */
hudakz	3:5b17e4656dd0	1278	UIP_STAT(++uip_stat.tcp.drop);
hudakz	3:5b17e4656dd0	1279	UIP_STAT(++uip_stat.tcp.chkerr);
hudakz	3:5b17e4656dd0	1280	UIP_LOG("tcp: bad checksum.");
hudakz	3:5b17e4656dd0	1281	goto drop;
hudakz	3:5b17e4656dd0	1282	}
hudakz	3:5b17e4656dd0	1283
hudakz	3:5b17e4656dd0	1284	/* Demultiplex this segment. */
hudakz	3:5b17e4656dd0	1285	/* First check any active connections. */
hudakz	8:4acb22344932	1286	for (uip_connr = &uip_conns[0]; uip_connr <= &uip_conns[UIP_CONNS - 1]; ++uip_connr) {
hudakz	3:5b17e4656dd0	1287	if
hudakz	3:5b17e4656dd0	1288	(
hudakz	3:5b17e4656dd0	1289	uip_connr->tcpstateflags != UIP_CLOSED
hudakz	3:5b17e4656dd0	1290	&& BUF->destport == uip_connr->lport
hudakz	3:5b17e4656dd0	1291	&& BUF->srcport == uip_connr->rport
hudakz	3:5b17e4656dd0	1292	&& uip_ipaddr_cmp(BUF->srcipaddr, uip_connr->ripaddr)
hudakz	3:5b17e4656dd0	1293	) {
hudakz	3:5b17e4656dd0	1294	goto found;
hudakz	3:5b17e4656dd0	1295	}
hudakz	3:5b17e4656dd0	1296	}
hudakz	3:5b17e4656dd0	1297
hudakz	3:5b17e4656dd0	1298	/* If we didn't find and active connection that expected the packet,
hudakz	3:5b17e4656dd0	1299	either this packet is an old duplicate, or this is a SYN packet
hudakz	3:5b17e4656dd0	1300	destined for a connection in LISTEN. If the SYN flag isn't set,
hudakz	3:5b17e4656dd0	1301	it is an old packet and we send a RST. */
hudakz	8:4acb22344932	1302	if ((BUF->flags & TCP_CTL) != TCP_SYN) {
hudakz	3:5b17e4656dd0	1303	goto reset;
hudakz	3:5b17e4656dd0	1304	}
hudakz	3:5b17e4656dd0	1305
hudakz	3:5b17e4656dd0	1306	tmp16 = BUF->destport;
hudakz	3:5b17e4656dd0	1307
hudakz	3:5b17e4656dd0	1308	/* Next, check listening connections. */
hudakz	8:4acb22344932	1309	for (c = 0; c < UIP_LISTENPORTS; ++c) {
hudakz	8:4acb22344932	1310	if (tmp16 == uip_listenports[c])
hudakz	3:5b17e4656dd0	1311	goto found_listen;
hudakz	3:5b17e4656dd0	1312	}
hudakz	3:5b17e4656dd0	1313
hudakz	3:5b17e4656dd0	1314	/* No matching connection found, so we send a RST packet. */
hudakz	3:5b17e4656dd0	1315	UIP_STAT(++uip_stat.tcp.synrst);
hudakz	3:5b17e4656dd0	1316	reset:
hudakz	3:5b17e4656dd0	1317	/* We do not send resets in response to resets. */
hudakz	8:4acb22344932	1318	if (BUF->flags & TCP_RST) {
hudakz	3:5b17e4656dd0	1319	goto drop;
hudakz	3:5b17e4656dd0	1320	}
hudakz	3:5b17e4656dd0	1321
hudakz	3:5b17e4656dd0	1322	UIP_STAT(++uip_stat.tcp.rst);
hudakz	3:5b17e4656dd0	1323
hudakz	3:5b17e4656dd0	1324	BUF->flags = TCP_RST \| TCP_ACK;
hudakz	3:5b17e4656dd0	1325	uip_len = UIP_IPTCPH_LEN;
hudakz	3:5b17e4656dd0	1326	BUF->tcpoffset = 5 << 4;
hudakz	3:5b17e4656dd0	1327
hudakz	3:5b17e4656dd0	1328	/* Flip the seqno and ackno fields in the TCP header. */
hudakz	3:5b17e4656dd0	1329	c = BUF->seqno[3];
hudakz	3:5b17e4656dd0	1330	BUF->seqno[3] = BUF->ackno[3];
hudakz	3:5b17e4656dd0	1331	BUF->ackno[3] = c;
hudakz	3:5b17e4656dd0	1332
hudakz	3:5b17e4656dd0	1333	c = BUF->seqno[2];
hudakz	3:5b17e4656dd0	1334	BUF->seqno[2] = BUF->ackno[2];
hudakz	3:5b17e4656dd0	1335	BUF->ackno[2] = c;
hudakz	3:5b17e4656dd0	1336
hudakz	3:5b17e4656dd0	1337	c = BUF->seqno[1];
hudakz	3:5b17e4656dd0	1338	BUF->seqno[1] = BUF->ackno[1];
hudakz	3:5b17e4656dd0	1339	BUF->ackno[1] = c;
hudakz	3:5b17e4656dd0	1340
hudakz	3:5b17e4656dd0	1341	c = BUF->seqno[0];
hudakz	3:5b17e4656dd0	1342	BUF->seqno[0] = BUF->ackno[0];
hudakz	3:5b17e4656dd0	1343	BUF->ackno[0] = c;
hudakz	3:5b17e4656dd0	1344
hudakz	3:5b17e4656dd0	1345	/* We also have to increase the sequence number we are
hudakz	3:5b17e4656dd0	1346	acknowledging. If the least significant byte overflowed, we need
hudakz	3:5b17e4656dd0	1347	to propagate the carry to the other bytes as well. */
hudakz	8:4acb22344932	1348	if (++BUF->ackno[3] == 0) {
hudakz	8:4acb22344932	1349	if (++BUF->ackno[2] == 0) {
hudakz	8:4acb22344932	1350	if (++BUF->ackno[1] == 0) {
hudakz	3:5b17e4656dd0	1351	++BUF->ackno[0];
hudakz	3:5b17e4656dd0	1352	}
hudakz	3:5b17e4656dd0	1353	}
hudakz	3:5b17e4656dd0	1354	}
hudakz	3:5b17e4656dd0	1355
hudakz	3:5b17e4656dd0	1356	/* Swap port numbers. */
hudakz	3:5b17e4656dd0	1357	tmp16 = BUF->srcport;
hudakz	3:5b17e4656dd0	1358	BUF->srcport = BUF->destport;
hudakz	3:5b17e4656dd0	1359	BUF->destport = tmp16;
hudakz	3:5b17e4656dd0	1360
hudakz	3:5b17e4656dd0	1361	/* Swap IP addresses. */
hudakz	3:5b17e4656dd0	1362	uip_ipaddr_copy(BUF->destipaddr, BUF->srcipaddr);
hudakz	3:5b17e4656dd0	1363	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	3:5b17e4656dd0	1364
hudakz	3:5b17e4656dd0	1365	/* And send out the RST packet! */
hudakz	3:5b17e4656dd0	1366	goto tcp_send_noconn;
hudakz	3:5b17e4656dd0	1367
hudakz	3:5b17e4656dd0	1368	/* This label will be jumped to if we matched the incoming packet
hudakz	3:5b17e4656dd0	1369	with a connection in LISTEN. In that case, we should create a new
hudakz	3:5b17e4656dd0	1370	connection and send a SYNACK in return. */
hudakz	3:5b17e4656dd0	1371	found_listen:
hudakz	3:5b17e4656dd0	1372	/* First we check if there are any connections avaliable. Unused
hudakz	3:5b17e4656dd0	1373	connections are kept in the same table as used connections, but
hudakz	3:5b17e4656dd0	1374	unused ones have the tcpstate set to CLOSED. Also, connections in
hudakz	3:5b17e4656dd0	1375	TIME_WAIT are kept track of and we'll use the oldest one if no
hudakz	3:5b17e4656dd0	1376	CLOSED connections are found. Thanks to Eddie C. Dost for a very
hudakz	3:5b17e4656dd0	1377	nice algorithm for the TIME_WAIT search. */
hudakz	3:5b17e4656dd0	1378	uip_connr = 0;
hudakz	8:4acb22344932	1379	for (c = 0; c < UIP_CONNS; ++c) {
hudakz	8:4acb22344932	1380	if (uip_conns[c].tcpstateflags == UIP_CLOSED) {
hudakz	3:5b17e4656dd0	1381	uip_connr = &uip_conns[c];
hudakz	3:5b17e4656dd0	1382	break;
hudakz	3:5b17e4656dd0	1383	}
hudakz	3:5b17e4656dd0	1384
hudakz	8:4acb22344932	1385	if (uip_conns[c].tcpstateflags == UIP_TIME_WAIT) {
hudakz	8:4acb22344932	1386	if (uip_connr == 0 \|\| uip_conns[c].timer > uip_connr->timer) {
hudakz	3:5b17e4656dd0	1387	uip_connr = &uip_conns[c];
hudakz	3:5b17e4656dd0	1388	}
hudakz	3:5b17e4656dd0	1389	}
hudakz	3:5b17e4656dd0	1390	}
hudakz	3:5b17e4656dd0	1391
hudakz	8:4acb22344932	1392	if (uip_connr == 0) {
hudakz	3:5b17e4656dd0	1393
hudakz	3:5b17e4656dd0	1394	/* All connections are used already, we drop packet and hope that
hudakz	3:5b17e4656dd0	1395	the remote end will retransmit the packet at a time when we
hudakz	3:5b17e4656dd0	1396	have more spare connections. */
hudakz	3:5b17e4656dd0	1397	UIP_STAT(++uip_stat.tcp.syndrop);
hudakz	3:5b17e4656dd0	1398	UIP_LOG("tcp: found no unused connections.");
hudakz	3:5b17e4656dd0	1399	goto drop;
hudakz	3:5b17e4656dd0	1400	}
hudakz	3:5b17e4656dd0	1401
hudakz	3:5b17e4656dd0	1402	uip_conn = uip_connr;
hudakz	3:5b17e4656dd0	1403
hudakz	3:5b17e4656dd0	1404	/* Fill in the necessary fields for the new connection. */
hudakz	3:5b17e4656dd0	1405	uip_connr->rto = uip_connr->timer = UIP_RTO;
hudakz	3:5b17e4656dd0	1406	uip_connr->sa = 0;
hudakz	3:5b17e4656dd0	1407	uip_connr->sv = 4;
hudakz	3:5b17e4656dd0	1408	uip_connr->nrtx = 0;
hudakz	3:5b17e4656dd0	1409	uip_connr->lport = BUF->destport;
hudakz	3:5b17e4656dd0	1410	uip_connr->rport = BUF->srcport;
hudakz	3:5b17e4656dd0	1411	uip_ipaddr_copy(uip_connr->ripaddr, BUF->srcipaddr);
hudakz	3:5b17e4656dd0	1412	uip_connr->tcpstateflags = UIP_SYN_RCVD;
hudakz	3:5b17e4656dd0	1413
hudakz	3:5b17e4656dd0	1414	uip_connr->snd_nxt[0] = iss[0];
hudakz	3:5b17e4656dd0	1415	uip_connr->snd_nxt[1] = iss[1];
hudakz	3:5b17e4656dd0	1416	uip_connr->snd_nxt[2] = iss[2];
hudakz	3:5b17e4656dd0	1417	uip_connr->snd_nxt[3] = iss[3];
hudakz	3:5b17e4656dd0	1418	uip_connr->len = 1;
hudakz	3:5b17e4656dd0	1419
hudakz	3:5b17e4656dd0	1420	/* rcv_nxt should be the seqno from the incoming packet + 1. */
hudakz	3:5b17e4656dd0	1421	uip_connr->rcv_nxt[3] = BUF->seqno[3];
hudakz	3:5b17e4656dd0	1422	uip_connr->rcv_nxt[2] = BUF->seqno[2];
hudakz	3:5b17e4656dd0	1423	uip_connr->rcv_nxt[1] = BUF->seqno[1];
hudakz	3:5b17e4656dd0	1424	uip_connr->rcv_nxt[0] = BUF->seqno[0];
hudakz	3:5b17e4656dd0	1425	uip_add_rcv_nxt(1);
hudakz	3:5b17e4656dd0	1426
hudakz	3:5b17e4656dd0	1427	/* Parse the TCP MSS option, if present. */
hudakz	8:4acb22344932	1428	if ((BUF->tcpoffset & 0xf0) > 0x50) {
hudakz	8:4acb22344932	1429	for (c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2;) {
hudakz	3:5b17e4656dd0	1430	opt = uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + c];
hudakz	8:4acb22344932	1431	if (opt == TCP_OPT_END) {
hudakz	3:5b17e4656dd0	1432
hudakz	3:5b17e4656dd0	1433	/* End of options. */
hudakz	3:5b17e4656dd0	1434	break;
hudakz	3:5b17e4656dd0	1435	}
hudakz	3:5b17e4656dd0	1436	else
hudakz	8:4acb22344932	1437	if (opt == TCP_OPT_NOOP) {
hudakz	3:5b17e4656dd0	1438	++c;
hudakz	3:5b17e4656dd0	1439
hudakz	3:5b17e4656dd0	1440	/* NOP option. */
hudakz	3:5b17e4656dd0	1441	}
hudakz	3:5b17e4656dd0	1442	else
hudakz	8:4acb22344932	1443	if (opt == TCP_OPT_MSS && uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
hudakz	3:5b17e4656dd0	1444
hudakz	3:5b17e4656dd0	1445	/* An MSS option with the right option length. */
hudakz	3:5b17e4656dd0	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	3:5b17e4656dd0	1447	uip_connr->initialmss = uip_connr->mss = tmp16 > UIP_TCP_MSS ? UIP_TCP_MSS : tmp16;
hudakz	3:5b17e4656dd0	1448
hudakz	3:5b17e4656dd0	1449	/* And we are done processing options. */
hudakz	3:5b17e4656dd0	1450	break;
hudakz	3:5b17e4656dd0	1451	}
hudakz	3:5b17e4656dd0	1452	else {
hudakz	3:5b17e4656dd0	1453
hudakz	3:5b17e4656dd0	1454	/* All other options have a length field, so that we easily
hudakz	4:d774541a34da	1455	can skip past them. */
hudakz	8:4acb22344932	1456	if (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
hudakz	3:5b17e4656dd0	1457
hudakz	3:5b17e4656dd0	1458	/* If the length field is zero, the options are malformed
hudakz	4:d774541a34da	1459	and we don't process them further. */
hudakz	3:5b17e4656dd0	1460	break;
hudakz	3:5b17e4656dd0	1461	}
hudakz	3:5b17e4656dd0	1462
hudakz	3:5b17e4656dd0	1463	c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
hudakz	3:5b17e4656dd0	1464	}
hudakz	3:5b17e4656dd0	1465	}
hudakz	3:5b17e4656dd0	1466	}
hudakz	3:5b17e4656dd0	1467
hudakz	3:5b17e4656dd0	1468	/* Our response will be a SYNACK. */
hudakz	3:5b17e4656dd0	1469	#if UIP_ACTIVE_OPEN
hudakz	3:5b17e4656dd0	1470	tcp_send_synack : BUF->flags = TCP_ACK;
hudakz	3:5b17e4656dd0	1471
hudakz	3:5b17e4656dd0	1472	tcp_send_syn:
hudakz	3:5b17e4656dd0	1473	BUF->flags \|= TCP_SYN;
hudakz	3:5b17e4656dd0	1474	#else /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	1475	tcp_send_synack : BUF->flags = TCP_SYN \| TCP_ACK;
hudakz	3:5b17e4656dd0	1476	#endif /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	1477
hudakz	3:5b17e4656dd0	1478	/* We send out the TCP Maximum Segment Size option with our
hudakz	3:5b17e4656dd0	1479	SYNACK. */
hudakz	3:5b17e4656dd0	1480
hudakz	3:5b17e4656dd0	1481	BUF->optdata[0] = TCP_OPT_MSS;
hudakz	3:5b17e4656dd0	1482	BUF->optdata[1] = TCP_OPT_MSS_LEN;
hudakz	3:5b17e4656dd0	1483	BUF->optdata[2] = (UIP_TCP_MSS) / 256;
hudakz	3:5b17e4656dd0	1484	BUF->optdata[3] = (UIP_TCP_MSS) & 255;
hudakz	3:5b17e4656dd0	1485	uip_len = UIP_IPTCPH_LEN + TCP_OPT_MSS_LEN;
hudakz	3:5b17e4656dd0	1486	BUF->tcpoffset = ((UIP_TCPH_LEN + TCP_OPT_MSS_LEN) / 4) << 4;
hudakz	3:5b17e4656dd0	1487	goto tcp_send;
hudakz	3:5b17e4656dd0	1488
hudakz	3:5b17e4656dd0	1489	/* This label will be jumped to if we found an active connection. */
hudakz	3:5b17e4656dd0	1490	found:
hudakz	3:5b17e4656dd0	1491	uip_conn = uip_connr;
hudakz	3:5b17e4656dd0	1492	uip_flags = 0;
hudakz	3:5b17e4656dd0	1493
hudakz	3:5b17e4656dd0	1494	/* We do a very naive form of TCP reset processing; we just accept
hudakz	3:5b17e4656dd0	1495	any RST and kill our connection. We should in fact check if the
hudakz	3:5b17e4656dd0	1496	sequence number of this reset is wihtin our advertised window
hudakz	3:5b17e4656dd0	1497	before we accept the reset. */
hudakz	8:4acb22344932	1498	if (BUF->flags & TCP_RST) {
hudakz	3:5b17e4656dd0	1499	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	3:5b17e4656dd0	1500	UIP_LOG("tcp: got reset, aborting connection.");
hudakz	3:5b17e4656dd0	1501	uip_flags = UIP_ABORT;
hudakz	3:5b17e4656dd0	1502	UIP_APPCALL();
hudakz	3:5b17e4656dd0	1503	goto drop;
hudakz	3:5b17e4656dd0	1504	}
hudakz	3:5b17e4656dd0	1505
hudakz	3:5b17e4656dd0	1506	/* Calculated the length of the data, if the application has sent
hudakz	3:5b17e4656dd0	1507	any data to us. */
hudakz	3:5b17e4656dd0	1508	c = (BUF->tcpoffset >> 4) << 2;
hudakz	3:5b17e4656dd0	1509
hudakz	3:5b17e4656dd0	1510	/* uip_len will contain the length of the actual TCP data. This is
hudakz	3:5b17e4656dd0	1511	calculated by subtracing the length of the TCP header (in
hudakz	3:5b17e4656dd0	1512	c) and the length of the IP header (20 bytes). */
hudakz	3:5b17e4656dd0	1513	uip_len = uip_len - c - UIP_IPH_LEN;
hudakz	3:5b17e4656dd0	1514
hudakz	3:5b17e4656dd0	1515	/* First, check if the sequence number of the incoming packet is
hudakz	3:5b17e4656dd0	1516	what we're expecting next. If not, we send out an ACK with the
hudakz	3:5b17e4656dd0	1517	correct numbers in. */
hudakz	8:4acb22344932	1518	if
hudakz	8:4acb22344932	1519	(
hudakz	8:4acb22344932	1520	!(((uip_connr->tcpstateflags & UIP_TS_MASK) == UIP_SYN_SENT)
hudakz	8:4acb22344932	1521	&& ((BUF->flags & TCP_CTL) == (TCP_SYN \| TCP_ACK))
hudakz	8:4acb22344932	1522	)
hudakz	8:4acb22344932	1523	) {
hudakz	3:5b17e4656dd0	1524	if
hudakz	3:5b17e4656dd0	1525	(
hudakz	3:5b17e4656dd0	1526	(uip_len > 0 \|\| ((BUF->flags & (TCP_SYN \| TCP_FIN)) != 0))
hudakz	3:5b17e4656dd0	1527	&& (
hudakz	3:5b17e4656dd0	1528	BUF->seqno[0] != uip_connr->rcv_nxt[0]
hudakz	3:5b17e4656dd0	1529	\|\| BUF->seqno[1] != uip_connr->rcv_nxt[1]
hudakz	3:5b17e4656dd0	1530	\|\| BUF->seqno[2] != uip_connr->rcv_nxt[2]
hudakz	3:5b17e4656dd0	1531	\|\| BUF->seqno[3] != uip_connr->rcv_nxt[3]
hudakz	3:5b17e4656dd0	1532	)
hudakz	3:5b17e4656dd0	1533	) {
hudakz	3:5b17e4656dd0	1534	goto tcp_send_ack;
hudakz	3:5b17e4656dd0	1535	}
hudakz	3:5b17e4656dd0	1536	}
hudakz	3:5b17e4656dd0	1537
hudakz	3:5b17e4656dd0	1538	/* Next, check if the incoming segment acknowledges any outstanding
hudakz	3:5b17e4656dd0	1539	data. If so, we update the sequence number, reset the length of
hudakz	3:5b17e4656dd0	1540	the outstanding data, calculate RTT estimations, and reset the
hudakz	3:5b17e4656dd0	1541	retransmission timer. */
hudakz	8:4acb22344932	1542	if ((BUF->flags & TCP_ACK) && uip_outstanding(uip_connr)) {
hudakz	3:5b17e4656dd0	1543	uip_add32(uip_connr->snd_nxt, uip_connr->len);
hudakz	3:5b17e4656dd0	1544
hudakz	3:5b17e4656dd0	1545	if
hudakz	3:5b17e4656dd0	1546	(
hudakz	3:5b17e4656dd0	1547	BUF->ackno[0] == uip_acc32[0]
hudakz	3:5b17e4656dd0	1548	&& BUF->ackno[1] == uip_acc32[1]
hudakz	3:5b17e4656dd0	1549	&& BUF->ackno[2] == uip_acc32[2]
hudakz	3:5b17e4656dd0	1550	&& BUF->ackno[3] == uip_acc32[3]
hudakz	3:5b17e4656dd0	1551	) {
hudakz	3:5b17e4656dd0	1552
hudakz	3:5b17e4656dd0	1553	/* Update sequence number. */
hudakz	3:5b17e4656dd0	1554	uip_connr->snd_nxt[0] = uip_acc32[0];
hudakz	3:5b17e4656dd0	1555	uip_connr->snd_nxt[1] = uip_acc32[1];
hudakz	3:5b17e4656dd0	1556	uip_connr->snd_nxt[2] = uip_acc32[2];
hudakz	3:5b17e4656dd0	1557	uip_connr->snd_nxt[3] = uip_acc32[3];
hudakz	3:5b17e4656dd0	1558
hudakz	3:5b17e4656dd0	1559	/* Do RTT estimation, unless we have done retransmissions. */
hudakz	8:4acb22344932	1560	if (uip_connr->nrtx == 0) {
hudakz	3:5b17e4656dd0	1561	signed char m;
hudakz	3:5b17e4656dd0	1562	m = uip_connr->rto - uip_connr->timer;
hudakz	3:5b17e4656dd0	1563
hudakz	3:5b17e4656dd0	1564	/* This is taken directly from VJs original code in his paper */
hudakz	3:5b17e4656dd0	1565	m = m - (uip_connr->sa >> 3);
hudakz	3:5b17e4656dd0	1566	uip_connr->sa += m;
hudakz	8:4acb22344932	1567	if (m < 0) {
hudakz	3:5b17e4656dd0	1568	m = -m;
hudakz	3:5b17e4656dd0	1569	}
hudakz	3:5b17e4656dd0	1570
hudakz	3:5b17e4656dd0	1571	m = m - (uip_connr->sv >> 2);
hudakz	3:5b17e4656dd0	1572	uip_connr->sv += m;
hudakz	3:5b17e4656dd0	1573	uip_connr->rto = (uip_connr->sa >> 3) + uip_connr->sv;
hudakz	3:5b17e4656dd0	1574	}
hudakz	3:5b17e4656dd0	1575
hudakz	3:5b17e4656dd0	1576	/* Set the acknowledged flag. */
hudakz	3:5b17e4656dd0	1577	uip_flags = UIP_ACKDATA;
hudakz	3:5b17e4656dd0	1578
hudakz	3:5b17e4656dd0	1579	/* Reset the retransmission timer. */
hudakz	3:5b17e4656dd0	1580	uip_connr->timer = uip_connr->rto;
hudakz	3:5b17e4656dd0	1581
hudakz	3:5b17e4656dd0	1582	/* Reset length of outstanding data. */
hudakz	3:5b17e4656dd0	1583	uip_connr->len = 0;
hudakz	3:5b17e4656dd0	1584	}
hudakz	3:5b17e4656dd0	1585	}
hudakz	3:5b17e4656dd0	1586
hudakz	3:5b17e4656dd0	1587	/* Do different things depending on in what state the connection is. */
hudakz	8:4acb22344932	1588	switch (uip_connr->tcpstateflags & UIP_TS_MASK) {
hudakz	8:4acb22344932	1589	/* CLOSED and LISTEN are not handled here. CLOSE_WAIT is not
hudakz	4:d774541a34da	1590	implemented, since we force the application to close when the
hudakz	4:d774541a34da	1591	peer sends a FIN (hence the application goes directly from
hudakz	4:d774541a34da	1592	ESTABLISHED to LAST_ACK). */
hudakz	8:4acb22344932	1593	case UIP_SYN_RCVD:
hudakz	8:4acb22344932	1594	/* In SYN_RCVD we have sent out a SYNACK in response to a SYN, and
hudakz	3:5b17e4656dd0	1595	we are waiting for an ACK that acknowledges the data we sent
hudakz	3:5b17e4656dd0	1596	out the last time. Therefore, we want to have the UIP_ACKDATA
hudakz	3:5b17e4656dd0	1597	flag set. If so, we enter the ESTABLISHED state. */
hudakz	8:4acb22344932	1598	if (uip_flags & UIP_ACKDATA) {
hudakz	8:4acb22344932	1599	uip_connr->tcpstateflags = UIP_ESTABLISHED;
hudakz	8:4acb22344932	1600	uip_flags = UIP_CONNECTED;
hudakz	8:4acb22344932	1601	uip_connr->len = 0;
hudakz	8:4acb22344932	1602	if (uip_len > 0) {
hudakz	8:4acb22344932	1603	uip_flags \|= UIP_NEWDATA;
hudakz	8:4acb22344932	1604	uip_add_rcv_nxt(uip_len);
hudakz	8:4acb22344932	1605	}
hudakz	8:4acb22344932	1606
hudakz	8:4acb22344932	1607	uip_slen = 0;
hudakz	8:4acb22344932	1608	UIP_APPCALL();
hudakz	8:4acb22344932	1609	goto appsend;
hudakz	3:5b17e4656dd0	1610	}
hudakz	3:5b17e4656dd0	1611
hudakz	8:4acb22344932	1612	goto drop;
hudakz	8:4acb22344932	1613	#if UIP_ACTIVE_OPEN
hudakz	3:5b17e4656dd0	1614
hudakz	8:4acb22344932	1615	case UIP_SYN_SENT:
hudakz	8:4acb22344932	1616	/* In SYN_SENT, we wait for a SYNACK that is sent in response to
hudakz	3:5b17e4656dd0	1617	our SYN. The rcv_nxt is set to sequence number in the SYNACK
hudakz	3:5b17e4656dd0	1618	plus one, and we send an ACK. We move into the ESTABLISHED
hudakz	3:5b17e4656dd0	1619	state. */
hudakz	8:4acb22344932	1620	if ((uip_flags & UIP_ACKDATA) && (BUF->flags & TCP_CTL) == (TCP_SYN \| TCP_ACK)) {
hudakz	3:5b17e4656dd0	1621
hudakz	8:4acb22344932	1622	/* Parse the TCP MSS option, if present. */
hudakz	8:4acb22344932	1623	if ((BUF->tcpoffset & 0xf0) > 0x50) {
hudakz	8:4acb22344932	1624	for (c = 0; c < ((BUF->tcpoffset >> 4) - 5) << 2;) {
hudakz	8:4acb22344932	1625	opt = uip_buf[UIP_IPTCPH_LEN + UIP_LLH_LEN + c];
hudakz	8:4acb22344932	1626	if (opt == TCP_OPT_END) {
hudakz	3:5b17e4656dd0	1627
hudakz	8:4acb22344932	1628	/* End of options. */
hudakz	8:4acb22344932	1629	break;
hudakz	8:4acb22344932	1630	}
hudakz	8:4acb22344932	1631	else
hudakz	8:4acb22344932	1632	if (opt == TCP_OPT_NOOP) {
hudakz	8:4acb22344932	1633	++c;
hudakz	3:5b17e4656dd0	1634
hudakz	8:4acb22344932	1635	/* NOP option. */
hudakz	8:4acb22344932	1636	}
hudakz	8:4acb22344932	1637	else
hudakz	8:4acb22344932	1638	if (opt == TCP_OPT_MSS && uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == TCP_OPT_MSS_LEN) {
hudakz	3:5b17e4656dd0	1639
hudakz	8:4acb22344932	1640	/* An MSS option with the right option length. */
hudakz	8:4acb22344932	1641	tmp16 = (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 2 + c] << 8) \| uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 3 + c];
hudakz	8:4acb22344932	1642	uip_connr->initialmss = uip_connr->mss = tmp16 > UIP_TCP_MSS ? UIP_TCP_MSS : tmp16;
hudakz	3:5b17e4656dd0	1643
hudakz	8:4acb22344932	1644	/* And we are done processing options. */
hudakz	3:5b17e4656dd0	1645	break;
hudakz	3:5b17e4656dd0	1646	}
hudakz	8:4acb22344932	1647	else {
hudakz	3:5b17e4656dd0	1648
hudakz	8:4acb22344932	1649	/* All other options have a length field, so that we easily
hudakz	8:4acb22344932	1650	can skip past them. */
hudakz	8:4acb22344932	1651	if (uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c] == 0) {
hudakz	8:4acb22344932	1652
hudakz	8:4acb22344932	1653	/* If the length field is zero, the options are malformed
hudakz	8:4acb22344932	1654	and we don't process them further. */
hudakz	8:4acb22344932	1655	break;
hudakz	8:4acb22344932	1656	}
hudakz	8:4acb22344932	1657
hudakz	8:4acb22344932	1658	c += uip_buf[UIP_TCPIP_HLEN + UIP_LLH_LEN + 1 + c];
hudakz	8:4acb22344932	1659	}
hudakz	3:5b17e4656dd0	1660	}
hudakz	3:5b17e4656dd0	1661	}
hudakz	8:4acb22344932	1662
hudakz	8:4acb22344932	1663	uip_connr->tcpstateflags = UIP_ESTABLISHED;
hudakz	8:4acb22344932	1664	uip_connr->rcv_nxt[0] = BUF->seqno[0];
hudakz	8:4acb22344932	1665	uip_connr->rcv_nxt[1] = BUF->seqno[1];
hudakz	8:4acb22344932	1666	uip_connr->rcv_nxt[2] = BUF->seqno[2];
hudakz	8:4acb22344932	1667	uip_connr->rcv_nxt[3] = BUF->seqno[3];
hudakz	8:4acb22344932	1668	uip_add_rcv_nxt(1);
hudakz	8:4acb22344932	1669	uip_flags = UIP_CONNECTED \| UIP_NEWDATA;
hudakz	8:4acb22344932	1670	uip_connr->len = 0;
hudakz	8:4acb22344932	1671	uip_len = 0;
hudakz	8:4acb22344932	1672	uip_slen = 0;
hudakz	8:4acb22344932	1673	UIP_APPCALL();
hudakz	8:4acb22344932	1674	goto appsend;
hudakz	3:5b17e4656dd0	1675	}
hudakz	3:5b17e4656dd0	1676
hudakz	8:4acb22344932	1677	/* Inform the application that the connection failed */
hudakz	8:4acb22344932	1678	uip_flags = UIP_ABORT;
hudakz	3:5b17e4656dd0	1679	UIP_APPCALL();
hudakz	3:5b17e4656dd0	1680
hudakz	8:4acb22344932	1681	/* The connection is closed after we send the RST */
hudakz	8:4acb22344932	1682	uip_conn->tcpstateflags = UIP_CLOSED;
hudakz	8:4acb22344932	1683	goto reset;
hudakz	8:4acb22344932	1684	#endif /* UIP_ACTIVE_OPEN */
hudakz	3:5b17e4656dd0	1685
hudakz	8:4acb22344932	1686	case UIP_ESTABLISHED:
hudakz	8:4acb22344932	1687	/* In the ESTABLISHED state, we call upon the application to feed
hudakz	3:5b17e4656dd0	1688	data into the uip_buf. If the UIP_ACKDATA flag is set, the
hudakz	3:5b17e4656dd0	1689	application should put new data into the buffer, otherwise we are
hudakz	3:5b17e4656dd0	1690	retransmitting an old segment, and the application should put that
hudakz	3:5b17e4656dd0	1691	data into the buffer.
hudakz	3:5b17e4656dd0	1692
hudakz	3:5b17e4656dd0	1693	If the incoming packet is a FIN, we should close the connection on
hudakz	3:5b17e4656dd0	1694	this side as well, and we send out a FIN and enter the LAST_ACK
hudakz	3:5b17e4656dd0	1695	state. We require that there is no outstanding data; otherwise the
hudakz	3:5b17e4656dd0	1696	sequence numbers will be screwed up. */
hudakz	8:4acb22344932	1697	if (BUF->flags & TCP_FIN && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
hudakz	8:4acb22344932	1698	if (uip_outstanding(uip_connr)) {
hudakz	8:4acb22344932	1699	goto drop;
hudakz	8:4acb22344932	1700	}
hudakz	3:5b17e4656dd0	1701
hudakz	8:4acb22344932	1702	uip_add_rcv_nxt(1 + uip_len);
hudakz	8:4acb22344932	1703	uip_flags \|= UIP_CLOSE;
hudakz	8:4acb22344932	1704	if (uip_len > 0) {
hudakz	8:4acb22344932	1705	uip_flags \|= UIP_NEWDATA;
hudakz	8:4acb22344932	1706	}
hudakz	8:4acb22344932	1707
hudakz	8:4acb22344932	1708	UIP_APPCALL();
hudakz	8:4acb22344932	1709	uip_connr->len = 1;
hudakz	8:4acb22344932	1710	uip_connr->tcpstateflags = UIP_LAST_ACK;
hudakz	8:4acb22344932	1711	uip_connr->nrtx = 0;
hudakz	8:4acb22344932	1712	tcp_send_finack:
hudakz	8:4acb22344932	1713	BUF->flags = TCP_FIN \| TCP_ACK;
hudakz	8:4acb22344932	1714	goto tcp_send_nodata;
hudakz	3:5b17e4656dd0	1715	}
hudakz	3:5b17e4656dd0	1716
hudakz	8:4acb22344932	1717	/* Check the URG flag. If this is set, the segment carries urgent
hudakz	8:4acb22344932	1718	data that we must pass to the application. */
hudakz	8:4acb22344932	1719	if ((BUF->flags & TCP_URG) != 0)
hudakz	8:4acb22344932	1720	{
hudakz	8:4acb22344932	1721	#if UIP_URGDATA > 0
hudakz	8:4acb22344932	1722	uip_urglen = (BUF->urgp[0] << 8) \| BUF->urgp[1];
hudakz	8:4acb22344932	1723	if (uip_urglen > uip_len) {
hudakz	8:4acb22344932	1724
hudakz	8:4acb22344932	1725	/* There is more urgent data in the next segment to come. */
hudakz	8:4acb22344932	1726	uip_urglen = uip_len;
hudakz	8:4acb22344932	1727	}
hudakz	3:5b17e4656dd0	1728
hudakz	8:4acb22344932	1729	uip_add_rcv_nxt(uip_urglen);
hudakz	8:4acb22344932	1730	uip_len -= uip_urglen;
hudakz	8:4acb22344932	1731	uip_urgdata = uip_appdata;
hudakz	8:4acb22344932	1732	uip_appdata += uip_urglen;
hudakz	8:4acb22344932	1733	}
hudakz	8:4acb22344932	1734	else {
hudakz	8:4acb22344932	1735	uip_urglen = 0;
hudakz	8:4acb22344932	1736	#else /* UIP_URGDATA > 0 */
hudakz	8:4acb22344932	1737	uip_appdata = ((char*)uip_appdata) + ((BUF->urgp[0] << 8) \| BUF->urgp[1]);
hudakz	8:4acb22344932	1738	uip_len -= (BUF->urgp[0] << 8) \| BUF->urgp[1];
hudakz	8:4acb22344932	1739	#endif /* UIP_URGDATA > 0 */
hudakz	3:5b17e4656dd0	1740	}
hudakz	3:5b17e4656dd0	1741
hudakz	8:4acb22344932	1742	/* If uip_len > 0 we have TCP data in the packet, and we flag this
hudakz	3:5b17e4656dd0	1743	by setting the UIP_NEWDATA flag and update the sequence number
hudakz	3:5b17e4656dd0	1744	we acknowledge. If the application has stopped the dataflow
hudakz	3:5b17e4656dd0	1745	using uip_stop(), we must not accept any data packets from the
hudakz	3:5b17e4656dd0	1746	remote host. */
hudakz	8:4acb22344932	1747	if (uip_len > 0 && !(uip_connr->tcpstateflags & UIP_STOPPED)) {
hudakz	8:4acb22344932	1748	uip_flags \|= UIP_NEWDATA;
hudakz	8:4acb22344932	1749	uip_add_rcv_nxt(uip_len);
hudakz	8:4acb22344932	1750	}
hudakz	3:5b17e4656dd0	1751
hudakz	8:4acb22344932	1752	/* Check if the available buffer space advertised by the other end
hudakz	3:5b17e4656dd0	1753	is smaller than the initial MSS for this connection. If so, we
hudakz	3:5b17e4656dd0	1754	set the current MSS to the window size to ensure that the
hudakz	3:5b17e4656dd0	1755	application does not send more data than the other end can
hudakz	3:5b17e4656dd0	1756	handle.
hudakz	3:5b17e4656dd0	1757
hudakz	3:5b17e4656dd0	1758	If the remote host advertises a zero window, we set the MSS to
hudakz	3:5b17e4656dd0	1759	the initial MSS so that the application will send an entire MSS
hudakz	3:5b17e4656dd0	1760	of data. This data will not be acknowledged by the receiver,
hudakz	3:5b17e4656dd0	1761	and the application will retransmit it. This is called the
hudakz	3:5b17e4656dd0	1762	"persistent timer" and uses the retransmission mechanim.
hudakz	3:5b17e4656dd0	1763	*/
hudakz	8:4acb22344932	1764	tmp16 = ((u16_t) BUF->wnd[0] << 8) + (u16_t) BUF->wnd[1];
hudakz	8:4acb22344932	1765	if (tmp16 > uip_connr->initialmss \|\| tmp16 == 0) {
hudakz	8:4acb22344932	1766	tmp16 = uip_connr->initialmss;
hudakz	8:4acb22344932	1767	}
hudakz	3:5b17e4656dd0	1768
hudakz	8:4acb22344932	1769	uip_connr->mss = tmp16;
hudakz	3:5b17e4656dd0	1770
hudakz	8:4acb22344932	1771	/* If this packet constitutes an ACK for outstanding data (flagged
hudakz	3:5b17e4656dd0	1772	by the UIP_ACKDATA flag, we should call the application since it
hudakz	3:5b17e4656dd0	1773	might want to send more data. If the incoming packet had data
hudakz	3:5b17e4656dd0	1774	from the peer (as flagged by the UIP_NEWDATA flag), the
hudakz	3:5b17e4656dd0	1775	application must also be notified.
hudakz	3:5b17e4656dd0	1776
hudakz	3:5b17e4656dd0	1777	When the application is called, the global variable uip_len
hudakz	3:5b17e4656dd0	1778	contains the length of the incoming data. The application can
hudakz	3:5b17e4656dd0	1779	access the incoming data through the global pointer
hudakz	3:5b17e4656dd0	1780	uip_appdata, which usually points UIP_IPTCPH_LEN + UIP_LLH_LEN
hudakz	3:5b17e4656dd0	1781	bytes into the uip_buf array.
hudakz	3:5b17e4656dd0	1782
hudakz	3:5b17e4656dd0	1783	If the application wishes to send any data, this data should be
hudakz	3:5b17e4656dd0	1784	put into the uip_appdata and the length of the data should be
hudakz	3:5b17e4656dd0	1785	put into uip_len. If the application don't have any data to
hudakz	3:5b17e4656dd0	1786	send, uip_len must be set to 0. */
hudakz	8:4acb22344932	1787	if (uip_flags & (UIP_NEWDATA \| UIP_ACKDATA)) {
hudakz	3:5b17e4656dd0	1788	uip_slen = 0;
hudakz	8:4acb22344932	1789	UIP_APPCALL();
hudakz	3:5b17e4656dd0	1790
hudakz	8:4acb22344932	1791	appsend:
hudakz	8:4acb22344932	1792	if (uip_flags & UIP_ABORT) {
hudakz	8:4acb22344932	1793	uip_slen = 0;
hudakz	8:4acb22344932	1794	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	8:4acb22344932	1795	BUF->flags = TCP_RST \| TCP_ACK;
hudakz	8:4acb22344932	1796	goto tcp_send_nodata;
hudakz	8:4acb22344932	1797	}
hudakz	3:5b17e4656dd0	1798
hudakz	8:4acb22344932	1799	if (uip_flags & UIP_CLOSE) {
hudakz	8:4acb22344932	1800	uip_slen = 0;
hudakz	8:4acb22344932	1801	uip_connr->len = 1;
hudakz	8:4acb22344932	1802	uip_connr->tcpstateflags = UIP_FIN_WAIT_1;
hudakz	8:4acb22344932	1803	uip_connr->nrtx = 0;
hudakz	8:4acb22344932	1804	BUF->flags = TCP_FIN \| TCP_ACK;
hudakz	8:4acb22344932	1805	goto tcp_send_nodata;
hudakz	3:5b17e4656dd0	1806	}
hudakz	3:5b17e4656dd0	1807
hudakz	8:4acb22344932	1808	/* If uip_slen > 0, the application has data to be sent. */
hudakz	8:4acb22344932	1809	if (uip_slen > 0) {
hudakz	8:4acb22344932	1810
hudakz	8:4acb22344932	1811	/* If the connection has acknowledged data, the contents of
hudakz	8:4acb22344932	1812	the ->len variable should be discarded. */
hudakz	8:4acb22344932	1813	if ((uip_flags & UIP_ACKDATA) != 0) {
hudakz	8:4acb22344932	1814	uip_connr->len = 0;
hudakz	8:4acb22344932	1815	}
hudakz	8:4acb22344932	1816
hudakz	8:4acb22344932	1817	/* If the ->len variable is non-zero the connection has
hudakz	4:d774541a34da	1818	already data in transit and cannot send anymore right
hudakz	4:d774541a34da	1819	now. */
hudakz	8:4acb22344932	1820	if (uip_connr->len == 0) {
hudakz	3:5b17e4656dd0	1821
hudakz	8:4acb22344932	1822	/* The application cannot send more than what is allowed by
hudakz	4:d774541a34da	1823	the mss (the minumum of the MSS and the available
hudakz	4:d774541a34da	1824	window). */
hudakz	8:4acb22344932	1825	if (uip_slen > uip_connr->mss) {
hudakz	8:4acb22344932	1826	uip_slen = uip_connr->mss;
hudakz	8:4acb22344932	1827	}
hudakz	3:5b17e4656dd0	1828
hudakz	8:4acb22344932	1829	/* Remember how much data we send out now so that we know
hudakz	4:d774541a34da	1830	when everything has been acknowledged. */
hudakz	8:4acb22344932	1831	uip_connr->len = uip_slen;
hudakz	8:4acb22344932	1832	}
hudakz	8:4acb22344932	1833	else {
hudakz	3:5b17e4656dd0	1834
hudakz	8:4acb22344932	1835	/* If the application already had unacknowledged data, we
hudakz	4:d774541a34da	1836	make sure that the application does not send (i.e.,
hudakz	4:d774541a34da	1837	retransmit) out more than it previously sent out. */
hudakz	8:4acb22344932	1838	uip_slen = uip_connr->len;
hudakz	8:4acb22344932	1839	}
hudakz	8:4acb22344932	1840	}
hudakz	8:4acb22344932	1841
hudakz	8:4acb22344932	1842	uip_connr->nrtx = 0;
hudakz	8:4acb22344932	1843	apprexmit:
hudakz	8:4acb22344932	1844	uip_appdata = uip_sappdata;
hudakz	8:4acb22344932	1845
hudakz	8:4acb22344932	1846	/* If the application has data to be sent, or if the incoming
hudakz	8:4acb22344932	1847	packet had new data in it, we must send out a packet. */
hudakz	8:4acb22344932	1848	if (uip_slen > 0 && uip_connr->len > 0) {
hudakz	8:4acb22344932	1849
hudakz	8:4acb22344932	1850	/* Add the length of the IP and TCP headers. */
hudakz	8:4acb22344932	1851	uip_len = uip_connr->len + UIP_TCPIP_HLEN;
hudakz	8:4acb22344932	1852
hudakz	8:4acb22344932	1853	/* We always set the ACK flag in response packets. */
hudakz	8:4acb22344932	1854	BUF->flags = TCP_ACK \| TCP_PSH;
hudakz	8:4acb22344932	1855
hudakz	8:4acb22344932	1856	/* Send the packet. */
hudakz	8:4acb22344932	1857	goto tcp_send_noopts;
hudakz	8:4acb22344932	1858	}
hudakz	8:4acb22344932	1859
hudakz	8:4acb22344932	1860	/* If there is no data to send, just send out a pure ACK if
hudakz	8:4acb22344932	1861	there is newdata. */
hudakz	8:4acb22344932	1862	if (uip_flags & UIP_NEWDATA) {
hudakz	8:4acb22344932	1863	uip_len = UIP_TCPIP_HLEN;
hudakz	8:4acb22344932	1864	BUF->flags = TCP_ACK;
hudakz	8:4acb22344932	1865	goto tcp_send_noopts;
hudakz	3:5b17e4656dd0	1866	}
hudakz	3:5b17e4656dd0	1867	}
hudakz	3:5b17e4656dd0	1868
hudakz	8:4acb22344932	1869	goto drop;
hudakz	3:5b17e4656dd0	1870
hudakz	8:4acb22344932	1871	case UIP_LAST_ACK:
hudakz	8:4acb22344932	1872	/* We can close this connection if the peer has acknowledged our
hudakz	8:4acb22344932	1873	FIN. This is indicated by the UIP_ACKDATA flag. */
hudakz	8:4acb22344932	1874	if (uip_flags & UIP_ACKDATA) {
hudakz	8:4acb22344932	1875	uip_connr->tcpstateflags = UIP_CLOSED;
hudakz	8:4acb22344932	1876	uip_flags = UIP_CLOSE;
hudakz	8:4acb22344932	1877	UIP_APPCALL();
hudakz	8:4acb22344932	1878	}
hudakz	8:4acb22344932	1879	break;
hudakz	3:5b17e4656dd0	1880
hudakz	8:4acb22344932	1881	case UIP_FIN_WAIT_1:
hudakz	8:4acb22344932	1882	/* The application has closed the connection, but the remote host
hudakz	8:4acb22344932	1883	hasn't closed its end yet. Thus we do nothing but wait for a
hudakz	8:4acb22344932	1884	FIN from the other side. */
hudakz	8:4acb22344932	1885	if (uip_len > 0) {
hudakz	8:4acb22344932	1886	uip_add_rcv_nxt(uip_len);
hudakz	3:5b17e4656dd0	1887	}
hudakz	3:5b17e4656dd0	1888
hudakz	8:4acb22344932	1889	if (BUF->flags & TCP_FIN) {
hudakz	8:4acb22344932	1890	if (uip_flags & UIP_ACKDATA) {
hudakz	8:4acb22344932	1891	uip_connr->tcpstateflags = UIP_TIME_WAIT;
hudakz	8:4acb22344932	1892	uip_connr->timer = 0;
hudakz	8:4acb22344932	1893	uip_connr->len = 0;
hudakz	8:4acb22344932	1894	}
hudakz	8:4acb22344932	1895	else {
hudakz	8:4acb22344932	1896	uip_connr->tcpstateflags = UIP_CLOSING;
hudakz	8:4acb22344932	1897	}
hudakz	3:5b17e4656dd0	1898
hudakz	8:4acb22344932	1899	uip_add_rcv_nxt(1);
hudakz	8:4acb22344932	1900	uip_flags = UIP_CLOSE;
hudakz	8:4acb22344932	1901	UIP_APPCALL();
hudakz	8:4acb22344932	1902	goto tcp_send_ack;
hudakz	8:4acb22344932	1903	}
hudakz	8:4acb22344932	1904	else
hudakz	8:4acb22344932	1905	if (uip_flags & UIP_ACKDATA) {
hudakz	8:4acb22344932	1906	uip_connr->tcpstateflags = UIP_FIN_WAIT_2;
hudakz	8:4acb22344932	1907	uip_connr->len = 0;
hudakz	8:4acb22344932	1908	goto drop;
hudakz	8:4acb22344932	1909	}
hudakz	3:5b17e4656dd0	1910
hudakz	8:4acb22344932	1911	if (uip_len > 0) {
hudakz	8:4acb22344932	1912	goto tcp_send_ack;
hudakz	8:4acb22344932	1913	}
hudakz	8:4acb22344932	1914
hudakz	8:4acb22344932	1915	goto drop;
hudakz	3:5b17e4656dd0	1916
hudakz	8:4acb22344932	1917	case UIP_FIN_WAIT_2:
hudakz	8:4acb22344932	1918	if (uip_len > 0) {
hudakz	8:4acb22344932	1919	uip_add_rcv_nxt(uip_len);
hudakz	8:4acb22344932	1920	}
hudakz	8:4acb22344932	1921
hudakz	8:4acb22344932	1922	if (BUF->flags & TCP_FIN) {
hudakz	3:5b17e4656dd0	1923	uip_connr->tcpstateflags = UIP_TIME_WAIT;
hudakz	3:5b17e4656dd0	1924	uip_connr->timer = 0;
hudakz	8:4acb22344932	1925	uip_add_rcv_nxt(1);
hudakz	8:4acb22344932	1926	uip_flags = UIP_CLOSE;
hudakz	8:4acb22344932	1927	UIP_APPCALL();
hudakz	8:4acb22344932	1928	goto tcp_send_ack;
hudakz	3:5b17e4656dd0	1929	}
hudakz	8:4acb22344932	1930
hudakz	8:4acb22344932	1931	if (uip_len > 0) {
hudakz	8:4acb22344932	1932	goto tcp_send_ack;
hudakz	3:5b17e4656dd0	1933	}
hudakz	3:5b17e4656dd0	1934
hudakz	8:4acb22344932	1935	goto drop;
hudakz	8:4acb22344932	1936
hudakz	8:4acb22344932	1937	case UIP_TIME_WAIT:
hudakz	3:5b17e4656dd0	1938	goto tcp_send_ack;
hudakz	3:5b17e4656dd0	1939
hudakz	8:4acb22344932	1940	case UIP_CLOSING:
hudakz	8:4acb22344932	1941	if (uip_flags & UIP_ACKDATA) {
hudakz	8:4acb22344932	1942	uip_connr->tcpstateflags = UIP_TIME_WAIT;
hudakz	8:4acb22344932	1943	uip_connr->timer = 0;
hudakz	8:4acb22344932	1944	}
hudakz	3:5b17e4656dd0	1945	}
hudakz	3:5b17e4656dd0	1946
hudakz	3:5b17e4656dd0	1947	goto drop;
hudakz	3:5b17e4656dd0	1948
hudakz	3:5b17e4656dd0	1949	/* We jump here when we are ready to send the packet, and just want
hudakz	3:5b17e4656dd0	1950	to set the appropriate TCP sequence numbers in the TCP header. */
hudakz	3:5b17e4656dd0	1951	tcp_send_ack:
hudakz	3:5b17e4656dd0	1952	BUF->flags = TCP_ACK;
hudakz	3:5b17e4656dd0	1953	tcp_send_nodata:
hudakz	3:5b17e4656dd0	1954	uip_len = UIP_IPTCPH_LEN;
hudakz	3:5b17e4656dd0	1955	tcp_send_noopts:
hudakz	3:5b17e4656dd0	1956	BUF->tcpoffset = (UIP_TCPH_LEN / 4) << 4;
hudakz	3:5b17e4656dd0	1957	tcp_send:
hudakz	3:5b17e4656dd0	1958	/* We're done with the input processing. We are now ready to send a
hudakz	3:5b17e4656dd0	1959	reply. Our job is to fill in all the fields of the TCP and IP
hudakz	3:5b17e4656dd0	1960	headers before calculating the checksum and finally send the
hudakz	3:5b17e4656dd0	1961	packet. */
hudakz	3:5b17e4656dd0	1962	BUF->ackno[0] = uip_connr->rcv_nxt[0];
hudakz	3:5b17e4656dd0	1963	BUF->ackno[1] = uip_connr->rcv_nxt[1];
hudakz	3:5b17e4656dd0	1964	BUF->ackno[2] = uip_connr->rcv_nxt[2];
hudakz	3:5b17e4656dd0	1965	BUF->ackno[3] = uip_connr->rcv_nxt[3];
hudakz	3:5b17e4656dd0	1966
hudakz	3:5b17e4656dd0	1967	BUF->seqno[0] = uip_connr->snd_nxt[0];
hudakz	3:5b17e4656dd0	1968	BUF->seqno[1] = uip_connr->snd_nxt[1];
hudakz	3:5b17e4656dd0	1969	BUF->seqno[2] = uip_connr->snd_nxt[2];
hudakz	3:5b17e4656dd0	1970	BUF->seqno[3] = uip_connr->snd_nxt[3];
hudakz	3:5b17e4656dd0	1971
hudakz	3:5b17e4656dd0	1972	BUF->proto = UIP_PROTO_TCP;
hudakz	3:5b17e4656dd0	1973
hudakz	3:5b17e4656dd0	1974	BUF->srcport = uip_connr->lport;
hudakz	3:5b17e4656dd0	1975	BUF->destport = uip_connr->rport;
hudakz	3:5b17e4656dd0	1976
hudakz	3:5b17e4656dd0	1977	uip_ipaddr_copy(BUF->srcipaddr, uip_hostaddr);
hudakz	3:5b17e4656dd0	1978	uip_ipaddr_copy(BUF->destipaddr, uip_connr->ripaddr);
hudakz	3:5b17e4656dd0	1979
hudakz	8:4acb22344932	1980	if (uip_connr->tcpstateflags & UIP_STOPPED) {
hudakz	3:5b17e4656dd0	1981
hudakz	3:5b17e4656dd0	1982	/* If the connection has issued uip_stop(), we advertise a zero
hudakz	3:5b17e4656dd0	1983	window so that the remote host will stop sending data. */
hudakz	3:5b17e4656dd0	1984	BUF->wnd[0] = BUF->wnd[1] = 0;
hudakz	3:5b17e4656dd0	1985	}
hudakz	3:5b17e4656dd0	1986	else {
hudakz	3:5b17e4656dd0	1987	BUF->wnd[0] = ((UIP_RECEIVE_WINDOW) >> 8);
hudakz	3:5b17e4656dd0	1988	BUF->wnd[1] = ((UIP_RECEIVE_WINDOW) & 0xff);
hudakz	3:5b17e4656dd0	1989	}
hudakz	3:5b17e4656dd0	1990
hudakz	3:5b17e4656dd0	1991	tcp_send_noconn:
hudakz	3:5b17e4656dd0	1992	BUF->ttl = UIP_TTL;
hudakz	3:5b17e4656dd0	1993	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	1994	/* For IPv6, the IP length field does not include the IPv6 IP header
hudakz	3:5b17e4656dd0	1995	length. */
hudakz	3:5b17e4656dd0	1996
hudakz	3:5b17e4656dd0	1997	BUF->len[0] = ((uip_len - UIP_IPH_LEN) >> 8);
hudakz	3:5b17e4656dd0	1998	BUF->len[1] = ((uip_len - UIP_IPH_LEN) & 0xff);
hudakz	3:5b17e4656dd0	1999	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	2000	BUF->len[0] = (uip_len >> 8);
hudakz	3:5b17e4656dd0	2001	BUF->len[1] = (uip_len & 0xff);
hudakz	3:5b17e4656dd0	2002	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	2003
hudakz	3:5b17e4656dd0	2004	BUF->urgp[0] = BUF->urgp[1] = 0;
hudakz	3:5b17e4656dd0	2005
hudakz	3:5b17e4656dd0	2006	/* Calculate TCP checksum. */
hudakz	3:5b17e4656dd0	2007	BUF->tcpchksum = 0;
hudakz	3:5b17e4656dd0	2008	BUF->tcpchksum = ~(uip_tcpchksum());
hudakz	3:5b17e4656dd0	2009
hudakz	3:5b17e4656dd0	2010	ip_send_nolen:
hudakz	3:5b17e4656dd0	2011	#if UIP_CONF_IPV6
hudakz	3:5b17e4656dd0	2012	BUF->vtc = 0x60;
hudakz	3:5b17e4656dd0	2013	BUF->tcflow = 0x00;
hudakz	3:5b17e4656dd0	2014	BUF->flow = 0x00;
hudakz	3:5b17e4656dd0	2015	#else /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	2016	BUF->vhl = 0x45;
hudakz	3:5b17e4656dd0	2017	BUF->tos = 0;
hudakz	3:5b17e4656dd0	2018	BUF->ipoffset[0] = BUF->ipoffset[1] = 0;
hudakz	3:5b17e4656dd0	2019	++ipid;
hudakz	3:5b17e4656dd0	2020	BUF->ipid[0] = ipid >> 8;
hudakz	3:5b17e4656dd0	2021	BUF->ipid[1] = ipid & 0xff;
hudakz	3:5b17e4656dd0	2022
hudakz	3:5b17e4656dd0	2023	/* Calculate IP checksum. */
hudakz	3:5b17e4656dd0	2024	BUF->ipchksum = 0;
hudakz	3:5b17e4656dd0	2025	BUF->ipchksum = ~(uip_ipchksum());
hudakz	3:5b17e4656dd0	2026	DEBUG_PRINTF("uip ip_send_nolen: chkecum 0x%04x\n", uip_ipchksum());
hudakz	3:5b17e4656dd0	2027	#endif /* UIP_CONF_IPV6 */
hudakz	3:5b17e4656dd0	2028
hudakz	3:5b17e4656dd0	2029	UIP_STAT(++uip_stat.tcp.sent);
hudakz	3:5b17e4656dd0	2030	send:
hudakz	3:5b17e4656dd0	2031	DEBUG_PRINTF("Sending packet with length %d (%d)\n", uip_len, (BUF->len[0] << 8) \| BUF->len[1]);
hudakz	3:5b17e4656dd0	2032
hudakz	3:5b17e4656dd0	2033	UIP_STAT(++uip_stat.ip.sent);
hudakz	3:5b17e4656dd0	2034
hudakz	3:5b17e4656dd0	2035	/* Return and let the caller do the actual transmission. */
hudakz	3:5b17e4656dd0	2036	uip_flags = 0;
hudakz	3:5b17e4656dd0	2037	return;
hudakz	3:5b17e4656dd0	2038	drop:
hudakz	3:5b17e4656dd0	2039	uip_len = 0;
hudakz	3:5b17e4656dd0	2040	uip_flags = 0;
hudakz	3:5b17e4656dd0	2041	return;
hudakz	3:5b17e4656dd0	2042	}
hudakz	3:5b17e4656dd0	2043
hudakz	3:5b17e4656dd0	2044	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	2045	u16_t htons(u16_t val) {
hudakz	3:5b17e4656dd0	2046	return HTONS(val);
hudakz	3:5b17e4656dd0	2047	}
hudakz	3:5b17e4656dd0	2048
hudakz	3:5b17e4656dd0	2049	/---------------------------------------------------------------------------/
hudakz	3:5b17e4656dd0	2050	void uip_send(const void* data, int len) {
hudakz	3:5b17e4656dd0	2051	uip_slen = len;
hudakz	8:4acb22344932	2052	if (len > 0) {
hudakz	8:4acb22344932	2053	if (data != uip_sappdata) {
hudakz	3:5b17e4656dd0	2054	memcpy(uip_sappdata, (data), uip_slen);
hudakz	3:5b17e4656dd0	2055	}
hudakz	3:5b17e4656dd0	2056	}
hudakz	3:5b17e4656dd0	2057	}
hudakz	3:5b17e4656dd0	2058
hudakz	3:5b17e4656dd0	2059	/** @} */

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Type:	Library
Created:	06 Jun 2022
Imports:	0
Forks:	0
Commits:	20
Dependents:	0
Dependencies:	0
Followers:	1

utility/uip.c@19:543c2d21e510, 2022-06-06 (annotated)

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