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lwip/core/ipv4/ip.c@0:ac1725ba162c, 2010-11-09 (annotated)

Committer:: segundo
Date:: Tue Nov 09 20:54:15 2010 +0000
Revision:: 0:ac1725ba162c

Who changed what in which revision?

User	Revision	Line number	New contents of line
segundo	0:ac1725ba162c	1	/**
segundo	0:ac1725ba162c	2	* @file
segundo	0:ac1725ba162c	3	* This is the IPv4 layer implementation for incoming and outgoing IP traffic.
segundo	0:ac1725ba162c	4	*
segundo	0:ac1725ba162c	5	* @see ip_frag.c
segundo	0:ac1725ba162c	6	*
segundo	0:ac1725ba162c	7	*/
segundo	0:ac1725ba162c	8
segundo	0:ac1725ba162c	9	/*
segundo	0:ac1725ba162c	10	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
segundo	0:ac1725ba162c	11	* All rights reserved.
segundo	0:ac1725ba162c	12	*
segundo	0:ac1725ba162c	13	* Redistribution and use in source and binary forms, with or without modification,
segundo	0:ac1725ba162c	14	* are permitted provided that the following conditions are met:
segundo	0:ac1725ba162c	15	*
segundo	0:ac1725ba162c	16	* 1. Redistributions of source code must retain the above copyright notice,
segundo	0:ac1725ba162c	17	* this list of conditions and the following disclaimer.
segundo	0:ac1725ba162c	18	* 2. Redistributions in binary form must reproduce the above copyright notice,
segundo	0:ac1725ba162c	19	* this list of conditions and the following disclaimer in the documentation
segundo	0:ac1725ba162c	20	* and/or other materials provided with the distribution.
segundo	0:ac1725ba162c	21	* 3. The name of the author may not be used to endorse or promote products
segundo	0:ac1725ba162c	22	* derived from this software without specific prior written permission.
segundo	0:ac1725ba162c	23	*
segundo	0:ac1725ba162c	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
segundo	0:ac1725ba162c	25	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
segundo	0:ac1725ba162c	26	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
segundo	0:ac1725ba162c	27	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
segundo	0:ac1725ba162c	28	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
segundo	0:ac1725ba162c	29	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
segundo	0:ac1725ba162c	30	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
segundo	0:ac1725ba162c	31	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
segundo	0:ac1725ba162c	32	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
segundo	0:ac1725ba162c	33	* OF SUCH DAMAGE.
segundo	0:ac1725ba162c	34	*
segundo	0:ac1725ba162c	35	* This file is part of the lwIP TCP/IP stack.
segundo	0:ac1725ba162c	36	*
segundo	0:ac1725ba162c	37	* Author: Adam Dunkels <adam@sics.se>
segundo	0:ac1725ba162c	38	*
segundo	0:ac1725ba162c	39	*/
segundo	0:ac1725ba162c	40
segundo	0:ac1725ba162c	41	#include "lwip/opt.h"
segundo	0:ac1725ba162c	42	#include "lwip/ip.h"
segundo	0:ac1725ba162c	43	#include "lwip/def.h"
segundo	0:ac1725ba162c	44	#include "lwip/mem.h"
segundo	0:ac1725ba162c	45	#include "lwip/ip_frag.h"
segundo	0:ac1725ba162c	46	#include "lwip/inet_chksum.h"
segundo	0:ac1725ba162c	47	#include "lwip/netif.h"
segundo	0:ac1725ba162c	48	#include "lwip/icmp.h"
segundo	0:ac1725ba162c	49	#include "lwip/igmp.h"
segundo	0:ac1725ba162c	50	#include "lwip/raw.h"
segundo	0:ac1725ba162c	51	#include "lwip/udp.h"
segundo	0:ac1725ba162c	52	#include "lwip/tcp_impl.h"
segundo	0:ac1725ba162c	53	#include "lwip/snmp.h"
segundo	0:ac1725ba162c	54	#include "lwip/dhcp.h"
segundo	0:ac1725ba162c	55	#include "lwip/autoip.h"
segundo	0:ac1725ba162c	56	#include "lwip/stats.h"
segundo	0:ac1725ba162c	57	#include "arch/perf.h"
segundo	0:ac1725ba162c	58
segundo	0:ac1725ba162c	59	#include <string.h>
segundo	0:ac1725ba162c	60
segundo	0:ac1725ba162c	61	/** Set this to 0 in the rare case of wanting to call an extra function to
segundo	0:ac1725ba162c	62	* generate the IP checksum (in contrast to calculating it on-the-fly). */
segundo	0:ac1725ba162c	63	#ifndef LWIP_INLINE_IP_CHKSUM
segundo	0:ac1725ba162c	64	#define LWIP_INLINE_IP_CHKSUM 1
segundo	0:ac1725ba162c	65	#endif
segundo	0:ac1725ba162c	66	#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
segundo	0:ac1725ba162c	67	#define CHECKSUM_GEN_IP_INLINE 1
segundo	0:ac1725ba162c	68	#else
segundo	0:ac1725ba162c	69	#define CHECKSUM_GEN_IP_INLINE 0
segundo	0:ac1725ba162c	70	#endif
segundo	0:ac1725ba162c	71
segundo	0:ac1725ba162c	72	#if LWIP_DHCP \|\| defined(LWIP_IP_ACCEPT_UDP_PORT)
segundo	0:ac1725ba162c	73	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
segundo	0:ac1725ba162c	74
segundo	0:ac1725ba162c	75	/** Some defines for DHCP to let link-layer-addressed packets through while the
segundo	0:ac1725ba162c	76	* netif is down.
segundo	0:ac1725ba162c	77	* To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT
segundo	0:ac1725ba162c	78	* to return 1 if the port is accepted and 0 if the port is not accepted.
segundo	0:ac1725ba162c	79	*/
segundo	0:ac1725ba162c	80	#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
segundo	0:ac1725ba162c	81	/* accept DHCP client port and custom port */
segundo	0:ac1725ba162c	82	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(DHCP_CLIENT_PORT)) \
segundo	0:ac1725ba162c	83	\|\| (LWIP_IP_ACCEPT_UDP_PORT(port)))
segundo	0:ac1725ba162c	84	#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
segundo	0:ac1725ba162c	85	/* accept custom port only */
segundo	0:ac1725ba162c	86	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(dst_port))
segundo	0:ac1725ba162c	87	#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
segundo	0:ac1725ba162c	88	/* accept DHCP client port only */
segundo	0:ac1725ba162c	89	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(DHCP_CLIENT_PORT))
segundo	0:ac1725ba162c	90	#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
segundo	0:ac1725ba162c	91
segundo	0:ac1725ba162c	92	#else /* LWIP_DHCP */
segundo	0:ac1725ba162c	93	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
segundo	0:ac1725ba162c	94	#endif /* LWIP_DHCP */
segundo	0:ac1725ba162c	95
segundo	0:ac1725ba162c	96	/**
segundo	0:ac1725ba162c	97	* The interface that provided the packet for the current callback
segundo	0:ac1725ba162c	98	* invocation.
segundo	0:ac1725ba162c	99	*/
segundo	0:ac1725ba162c	100	struct netif *current_netif;
segundo	0:ac1725ba162c	101
segundo	0:ac1725ba162c	102	/**
segundo	0:ac1725ba162c	103	* Header of the input packet currently being processed.
segundo	0:ac1725ba162c	104	*/
segundo	0:ac1725ba162c	105	const struct ip_hdr *current_header;
segundo	0:ac1725ba162c	106	/** Source IP address of current_header */
segundo	0:ac1725ba162c	107	ip_addr_t current_iphdr_src;
segundo	0:ac1725ba162c	108	/** Destination IP address of current_header */
segundo	0:ac1725ba162c	109	ip_addr_t current_iphdr_dest;
segundo	0:ac1725ba162c	110
segundo	0:ac1725ba162c	111	/** The IP header ID of the next outgoing IP packet */
segundo	0:ac1725ba162c	112	static u16_t ip_id;
segundo	0:ac1725ba162c	113
segundo	0:ac1725ba162c	114	/**
segundo	0:ac1725ba162c	115	* Finds the appropriate network interface for a given IP address. It
segundo	0:ac1725ba162c	116	* searches the list of network interfaces linearly. A match is found
segundo	0:ac1725ba162c	117	* if the masked IP address of the network interface equals the masked
segundo	0:ac1725ba162c	118	* IP address given to the function.
segundo	0:ac1725ba162c	119	*
segundo	0:ac1725ba162c	120	* @param dest the destination IP address for which to find the route
segundo	0:ac1725ba162c	121	* @return the netif on which to send to reach dest
segundo	0:ac1725ba162c	122	*/
segundo	0:ac1725ba162c	123	struct netif *
segundo	0:ac1725ba162c	124	ip_route(ip_addr_t *dest)
segundo	0:ac1725ba162c	125	{
segundo	0:ac1725ba162c	126	struct netif *netif;
segundo	0:ac1725ba162c	127
segundo	0:ac1725ba162c	128	/* iterate through netifs */
segundo	0:ac1725ba162c	129	for(netif = netif_list; netif != NULL; netif = netif->next) {
segundo	0:ac1725ba162c	130	/* network mask matches? */
segundo	0:ac1725ba162c	131	if (netif_is_up(netif)) {
segundo	0:ac1725ba162c	132	if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
segundo	0:ac1725ba162c	133	/* return netif on which to forward IP packet */
segundo	0:ac1725ba162c	134	return netif;
segundo	0:ac1725ba162c	135	}
segundo	0:ac1725ba162c	136	}
segundo	0:ac1725ba162c	137	}
segundo	0:ac1725ba162c	138	if ((netif_default == NULL) \|\| (!netif_is_up(netif_default))) {
segundo	0:ac1725ba162c	139	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
segundo	0:ac1725ba162c	140	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
segundo	0:ac1725ba162c	141	IP_STATS_INC(ip.rterr);
segundo	0:ac1725ba162c	142	snmp_inc_ipoutnoroutes();
segundo	0:ac1725ba162c	143	return NULL;
segundo	0:ac1725ba162c	144	}
segundo	0:ac1725ba162c	145	/* no matching netif found, use default netif */
segundo	0:ac1725ba162c	146	return netif_default;
segundo	0:ac1725ba162c	147	}
segundo	0:ac1725ba162c	148
segundo	0:ac1725ba162c	149	#if IP_FORWARD
segundo	0:ac1725ba162c	150	/**
segundo	0:ac1725ba162c	151	* Forwards an IP packet. It finds an appropriate route for the
segundo	0:ac1725ba162c	152	* packet, decrements the TTL value of the packet, adjusts the
segundo	0:ac1725ba162c	153	* checksum and outputs the packet on the appropriate interface.
segundo	0:ac1725ba162c	154	*
segundo	0:ac1725ba162c	155	* @param p the packet to forward (p->payload points to IP header)
segundo	0:ac1725ba162c	156	* @param iphdr the IP header of the input packet
segundo	0:ac1725ba162c	157	* @param inp the netif on which this packet was received
segundo	0:ac1725ba162c	158	*/
segundo	0:ac1725ba162c	159	static void
segundo	0:ac1725ba162c	160	ip_forward(struct pbuf p, struct ip_hdr iphdr, struct netif *inp)
segundo	0:ac1725ba162c	161	{
segundo	0:ac1725ba162c	162	struct netif *netif;
segundo	0:ac1725ba162c	163
segundo	0:ac1725ba162c	164	PERF_START;
segundo	0:ac1725ba162c	165
segundo	0:ac1725ba162c	166	/* RFC3927 2.7: do not forward link-local addresses */
segundo	0:ac1725ba162c	167	if (ip_addr_islinklocal(&current_iphdr_dest)) {
segundo	0:ac1725ba162c	168	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
segundo	0:ac1725ba162c	169	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
segundo	0:ac1725ba162c	170	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
segundo	0:ac1725ba162c	171	goto return_noroute;
segundo	0:ac1725ba162c	172	}
segundo	0:ac1725ba162c	173
segundo	0:ac1725ba162c	174	/* Find network interface where to forward this IP packet to. */
segundo	0:ac1725ba162c	175	netif = ip_route(&current_iphdr_dest);
segundo	0:ac1725ba162c	176	if (netif == NULL) {
segundo	0:ac1725ba162c	177	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
segundo	0:ac1725ba162c	178	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
segundo	0:ac1725ba162c	179	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
segundo	0:ac1725ba162c	180	goto return_noroute;
segundo	0:ac1725ba162c	181	}
segundo	0:ac1725ba162c	182	/* Do not forward packets onto the same network interface on which
segundo	0:ac1725ba162c	183	* they arrived. */
segundo	0:ac1725ba162c	184	if (netif == inp) {
segundo	0:ac1725ba162c	185	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
segundo	0:ac1725ba162c	186	goto return_noroute;
segundo	0:ac1725ba162c	187	}
segundo	0:ac1725ba162c	188
segundo	0:ac1725ba162c	189	/* decrement TTL */
segundo	0:ac1725ba162c	190	IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
segundo	0:ac1725ba162c	191	/* send ICMP if TTL == 0 */
segundo	0:ac1725ba162c	192	if (IPH_TTL(iphdr) == 0) {
segundo	0:ac1725ba162c	193	snmp_inc_ipinhdrerrors();
segundo	0:ac1725ba162c	194	#if LWIP_ICMP
segundo	0:ac1725ba162c	195	/* Don't send ICMP messages in response to ICMP messages */
segundo	0:ac1725ba162c	196	if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
segundo	0:ac1725ba162c	197	icmp_time_exceeded(p, ICMP_TE_TTL);
segundo	0:ac1725ba162c	198	}
segundo	0:ac1725ba162c	199	#endif /* LWIP_ICMP */
segundo	0:ac1725ba162c	200	return;
segundo	0:ac1725ba162c	201	}
segundo	0:ac1725ba162c	202
segundo	0:ac1725ba162c	203	/* Incrementally update the IP checksum. */
segundo	0:ac1725ba162c	204	if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffff - 0x100)) {
segundo	0:ac1725ba162c	205	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
segundo	0:ac1725ba162c	206	} else {
segundo	0:ac1725ba162c	207	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
segundo	0:ac1725ba162c	208	}
segundo	0:ac1725ba162c	209
segundo	0:ac1725ba162c	210	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
segundo	0:ac1725ba162c	211	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
segundo	0:ac1725ba162c	212	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
segundo	0:ac1725ba162c	213
segundo	0:ac1725ba162c	214	IP_STATS_INC(ip.fw);
segundo	0:ac1725ba162c	215	IP_STATS_INC(ip.xmit);
segundo	0:ac1725ba162c	216	snmp_inc_ipforwdatagrams();
segundo	0:ac1725ba162c	217
segundo	0:ac1725ba162c	218	PERF_STOP("ip_forward");
segundo	0:ac1725ba162c	219	/* transmit pbuf on chosen interface */
segundo	0:ac1725ba162c	220	netif->output(netif, p, &current_iphdr_dest);
segundo	0:ac1725ba162c	221	return;
segundo	0:ac1725ba162c	222	return_noroute:
segundo	0:ac1725ba162c	223	snmp_inc_ipoutnoroutes();
segundo	0:ac1725ba162c	224	}
segundo	0:ac1725ba162c	225	#endif /* IP_FORWARD */
segundo	0:ac1725ba162c	226
segundo	0:ac1725ba162c	227	/**
segundo	0:ac1725ba162c	228	* This function is called by the network interface device driver when
segundo	0:ac1725ba162c	229	* an IP packet is received. The function does the basic checks of the
segundo	0:ac1725ba162c	230	* IP header such as packet size being at least larger than the header
segundo	0:ac1725ba162c	231	* size etc. If the packet was not destined for us, the packet is
segundo	0:ac1725ba162c	232	* forwarded (using ip_forward). The IP checksum is always checked.
segundo	0:ac1725ba162c	233	*
segundo	0:ac1725ba162c	234	* Finally, the packet is sent to the upper layer protocol input function.
segundo	0:ac1725ba162c	235	*
segundo	0:ac1725ba162c	236	* @param p the received IP packet (p->payload points to IP header)
segundo	0:ac1725ba162c	237	* @param inp the netif on which this packet was received
segundo	0:ac1725ba162c	238	* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
segundo	0:ac1725ba162c	239	* processed, but currently always returns ERR_OK)
segundo	0:ac1725ba162c	240	*/
segundo	0:ac1725ba162c	241	err_t
segundo	0:ac1725ba162c	242	ip_input(struct pbuf p, struct netif inp)
segundo	0:ac1725ba162c	243	{
segundo	0:ac1725ba162c	244	struct ip_hdr *iphdr;
segundo	0:ac1725ba162c	245	struct netif *netif;
segundo	0:ac1725ba162c	246	u16_t iphdr_hlen;
segundo	0:ac1725ba162c	247	u16_t iphdr_len;
segundo	0:ac1725ba162c	248	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
segundo	0:ac1725ba162c	249	int check_ip_src=1;
segundo	0:ac1725ba162c	250	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
segundo	0:ac1725ba162c	251
segundo	0:ac1725ba162c	252	IP_STATS_INC(ip.recv);
segundo	0:ac1725ba162c	253	snmp_inc_ipinreceives();
segundo	0:ac1725ba162c	254
segundo	0:ac1725ba162c	255	/* identify the IP header */
segundo	0:ac1725ba162c	256	iphdr = (struct ip_hdr *)p->payload;
segundo	0:ac1725ba162c	257	if (IPH_V(iphdr) != 4) {
segundo	0:ac1725ba162c	258	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
segundo	0:ac1725ba162c	259	ip_debug_print(p);
segundo	0:ac1725ba162c	260	pbuf_free(p);
segundo	0:ac1725ba162c	261	IP_STATS_INC(ip.err);
segundo	0:ac1725ba162c	262	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	263	snmp_inc_ipinhdrerrors();
segundo	0:ac1725ba162c	264	return ERR_OK;
segundo	0:ac1725ba162c	265	}
segundo	0:ac1725ba162c	266
segundo	0:ac1725ba162c	267	/* obtain IP header length in number of 32-bit words */
segundo	0:ac1725ba162c	268	iphdr_hlen = IPH_HL(iphdr);
segundo	0:ac1725ba162c	269	/* calculate IP header length in bytes */
segundo	0:ac1725ba162c	270	iphdr_hlen *= 4;
segundo	0:ac1725ba162c	271	/* obtain ip length in bytes */
segundo	0:ac1725ba162c	272	iphdr_len = ntohs(IPH_LEN(iphdr));
segundo	0:ac1725ba162c	273
segundo	0:ac1725ba162c	274	/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
segundo	0:ac1725ba162c	275	if ((iphdr_hlen > p->len) \|\| (iphdr_len > p->tot_len)) {
segundo	0:ac1725ba162c	276	if (iphdr_hlen > p->len) {
segundo	0:ac1725ba162c	277	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
segundo	0:ac1725ba162c	278	("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
segundo	0:ac1725ba162c	279	iphdr_hlen, p->len));
segundo	0:ac1725ba162c	280	}
segundo	0:ac1725ba162c	281	if (iphdr_len > p->tot_len) {
segundo	0:ac1725ba162c	282	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
segundo	0:ac1725ba162c	283	("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
segundo	0:ac1725ba162c	284	iphdr_len, p->tot_len));
segundo	0:ac1725ba162c	285	}
segundo	0:ac1725ba162c	286	/* free (drop) packet pbufs */
segundo	0:ac1725ba162c	287	pbuf_free(p);
segundo	0:ac1725ba162c	288	IP_STATS_INC(ip.lenerr);
segundo	0:ac1725ba162c	289	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	290	snmp_inc_ipindiscards();
segundo	0:ac1725ba162c	291	return ERR_OK;
segundo	0:ac1725ba162c	292	}
segundo	0:ac1725ba162c	293
segundo	0:ac1725ba162c	294	/* verify checksum */
segundo	0:ac1725ba162c	295	#if CHECKSUM_CHECK_IP
segundo	0:ac1725ba162c	296	if (inet_chksum(iphdr, iphdr_hlen) != 0) {
segundo	0:ac1725ba162c	297
segundo	0:ac1725ba162c	298	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
segundo	0:ac1725ba162c	299	("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
segundo	0:ac1725ba162c	300	ip_debug_print(p);
segundo	0:ac1725ba162c	301	pbuf_free(p);
segundo	0:ac1725ba162c	302	IP_STATS_INC(ip.chkerr);
segundo	0:ac1725ba162c	303	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	304	snmp_inc_ipinhdrerrors();
segundo	0:ac1725ba162c	305	return ERR_OK;
segundo	0:ac1725ba162c	306	}
segundo	0:ac1725ba162c	307	#endif
segundo	0:ac1725ba162c	308
segundo	0:ac1725ba162c	309	/* Trim pbuf. This should have been done at the netif layer,
segundo	0:ac1725ba162c	310	* but we'll do it anyway just to be sure that its done. */
segundo	0:ac1725ba162c	311	pbuf_realloc(p, iphdr_len);
segundo	0:ac1725ba162c	312
segundo	0:ac1725ba162c	313	/* copy IP addresses to aligned ip_addr_t */
segundo	0:ac1725ba162c	314	ip_addr_copy(current_iphdr_dest, iphdr->dest);
segundo	0:ac1725ba162c	315	ip_addr_copy(current_iphdr_src, iphdr->src);
segundo	0:ac1725ba162c	316
segundo	0:ac1725ba162c	317	/* match packet against an interface, i.e. is this packet for us? */
segundo	0:ac1725ba162c	318	#if LWIP_IGMP
segundo	0:ac1725ba162c	319	if (ip_addr_ismulticast(&current_iphdr_dest)) {
segundo	0:ac1725ba162c	320	if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &current_iphdr_dest))) {
segundo	0:ac1725ba162c	321	netif = inp;
segundo	0:ac1725ba162c	322	} else {
segundo	0:ac1725ba162c	323	netif = NULL;
segundo	0:ac1725ba162c	324	}
segundo	0:ac1725ba162c	325	} else
segundo	0:ac1725ba162c	326	#endif /* LWIP_IGMP */
segundo	0:ac1725ba162c	327	{
segundo	0:ac1725ba162c	328	/* start trying with inp. if that's not acceptable, start walking the
segundo	0:ac1725ba162c	329	list of configured netifs.
segundo	0:ac1725ba162c	330	'first' is used as a boolean to mark whether we started walking the list */
segundo	0:ac1725ba162c	331	int first = 1;
segundo	0:ac1725ba162c	332	netif = inp;
segundo	0:ac1725ba162c	333	do {
segundo	0:ac1725ba162c	334	LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest 0x%"X32_F" netif->ip_addr 0x%"X32_F" (0x%"X32_F", 0x%"X32_F", 0x%"X32_F")\n",
segundo	0:ac1725ba162c	335	ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
segundo	0:ac1725ba162c	336	ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
segundo	0:ac1725ba162c	337	ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
segundo	0:ac1725ba162c	338	ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
segundo	0:ac1725ba162c	339
segundo	0:ac1725ba162c	340	/* interface is up and configured? */
segundo	0:ac1725ba162c	341	if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
segundo	0:ac1725ba162c	342	/* unicast to this interface address? */
segundo	0:ac1725ba162c	343	if (ip_addr_cmp(&current_iphdr_dest, &(netif->ip_addr)) \|\|
segundo	0:ac1725ba162c	344	/* or broadcast on this interface network address? */
segundo	0:ac1725ba162c	345	ip_addr_isbroadcast(&current_iphdr_dest, netif)) {
segundo	0:ac1725ba162c	346	LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
segundo	0:ac1725ba162c	347	netif->name[0], netif->name[1]));
segundo	0:ac1725ba162c	348	/* break out of for loop */
segundo	0:ac1725ba162c	349	break;
segundo	0:ac1725ba162c	350	}
segundo	0:ac1725ba162c	351	#if LWIP_AUTOIP
segundo	0:ac1725ba162c	352	/* connections to link-local addresses must persist after changing
segundo	0:ac1725ba162c	353	the netif's address (RFC3927 ch. 1.9) */
segundo	0:ac1725ba162c	354	if ((netif->autoip != NULL) &&
segundo	0:ac1725ba162c	355	ip_addr_cmp(&current_iphdr_dest, &(netif->autoip->llipaddr))) {
segundo	0:ac1725ba162c	356	LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
segundo	0:ac1725ba162c	357	netif->name[0], netif->name[1]));
segundo	0:ac1725ba162c	358	/* break out of for loop */
segundo	0:ac1725ba162c	359	break;
segundo	0:ac1725ba162c	360	}
segundo	0:ac1725ba162c	361	#endif /* LWIP_AUTOIP */
segundo	0:ac1725ba162c	362	}
segundo	0:ac1725ba162c	363	if (first) {
segundo	0:ac1725ba162c	364	first = 0;
segundo	0:ac1725ba162c	365	netif = netif_list;
segundo	0:ac1725ba162c	366	} else {
segundo	0:ac1725ba162c	367	netif = netif->next;
segundo	0:ac1725ba162c	368	}
segundo	0:ac1725ba162c	369	if (netif == inp) {
segundo	0:ac1725ba162c	370	netif = netif->next;
segundo	0:ac1725ba162c	371	}
segundo	0:ac1725ba162c	372	} while(netif != NULL);
segundo	0:ac1725ba162c	373	}
segundo	0:ac1725ba162c	374
segundo	0:ac1725ba162c	375	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
segundo	0:ac1725ba162c	376	/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
segundo	0:ac1725ba162c	377	* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
segundo	0:ac1725ba162c	378	* According to RFC 1542 section 3.1.1, referred by RFC 2131).
segundo	0:ac1725ba162c	379	*
segundo	0:ac1725ba162c	380	* If you want to accept private broadcast communication while a netif is down,
segundo	0:ac1725ba162c	381	* define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
segundo	0:ac1725ba162c	382	*
segundo	0:ac1725ba162c	383	* #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
segundo	0:ac1725ba162c	384	*/
segundo	0:ac1725ba162c	385	if (netif == NULL) {
segundo	0:ac1725ba162c	386	/* remote port is DHCP server? */
segundo	0:ac1725ba162c	387	if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
segundo	0:ac1725ba162c	388	struct udp_hdr udphdr = (struct udp_hdr )((u8_t *)iphdr + iphdr_hlen);
segundo	0:ac1725ba162c	389	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
segundo	0:ac1725ba162c	390	ntohs(udphdr->dest)));
segundo	0:ac1725ba162c	391	if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
segundo	0:ac1725ba162c	392	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
segundo	0:ac1725ba162c	393	netif = inp;
segundo	0:ac1725ba162c	394	check_ip_src = 0;
segundo	0:ac1725ba162c	395	}
segundo	0:ac1725ba162c	396	}
segundo	0:ac1725ba162c	397	}
segundo	0:ac1725ba162c	398	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
segundo	0:ac1725ba162c	399
segundo	0:ac1725ba162c	400	/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
segundo	0:ac1725ba162c	401	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
segundo	0:ac1725ba162c	402	/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
segundo	0:ac1725ba162c	403	if (check_ip_src && !ip_addr_isany(&current_iphdr_src))
segundo	0:ac1725ba162c	404	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
segundo	0:ac1725ba162c	405	{ if ((ip_addr_isbroadcast(&current_iphdr_src, inp)) \|\|
segundo	0:ac1725ba162c	406	(ip_addr_ismulticast(&current_iphdr_src))) {
segundo	0:ac1725ba162c	407	/* packet source is not valid */
segundo	0:ac1725ba162c	408	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
segundo	0:ac1725ba162c	409	/* free (drop) packet pbufs */
segundo	0:ac1725ba162c	410	pbuf_free(p);
segundo	0:ac1725ba162c	411	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	412	snmp_inc_ipinaddrerrors();
segundo	0:ac1725ba162c	413	snmp_inc_ipindiscards();
segundo	0:ac1725ba162c	414	return ERR_OK;
segundo	0:ac1725ba162c	415	}
segundo	0:ac1725ba162c	416	}
segundo	0:ac1725ba162c	417
segundo	0:ac1725ba162c	418	/* packet not for us? */
segundo	0:ac1725ba162c	419	if (netif == NULL) {
segundo	0:ac1725ba162c	420	/* packet not for us, route or discard */
segundo	0:ac1725ba162c	421	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
segundo	0:ac1725ba162c	422	#if IP_FORWARD
segundo	0:ac1725ba162c	423	/* non-broadcast packet? */
segundo	0:ac1725ba162c	424	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp)) {
segundo	0:ac1725ba162c	425	/* try to forward IP packet on (other) interfaces */
segundo	0:ac1725ba162c	426	ip_forward(p, iphdr, inp);
segundo	0:ac1725ba162c	427	} else
segundo	0:ac1725ba162c	428	#endif /* IP_FORWARD */
segundo	0:ac1725ba162c	429	{
segundo	0:ac1725ba162c	430	snmp_inc_ipinaddrerrors();
segundo	0:ac1725ba162c	431	snmp_inc_ipindiscards();
segundo	0:ac1725ba162c	432	}
segundo	0:ac1725ba162c	433	pbuf_free(p);
segundo	0:ac1725ba162c	434	return ERR_OK;
segundo	0:ac1725ba162c	435	}
segundo	0:ac1725ba162c	436	/* packet consists of multiple fragments? */
segundo	0:ac1725ba162c	437	if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK \| IP_MF)) != 0) {
segundo	0:ac1725ba162c	438	#if IP_REASSEMBLY /* packet fragment reassembly code present? */
segundo	0:ac1725ba162c	439	LWIP_DEBUGF(IP_DEBUG, ("IP packet is a fragment (id=0x%04"X16_F" tot_len=%"U16_F" len=%"U16_F" MF=%"U16_F" offset=%"U16_F"), calling ip_reass()\n",
segundo	0:ac1725ba162c	440	ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & PP_HTONS(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
segundo	0:ac1725ba162c	441	/* reassemble the packet*/
segundo	0:ac1725ba162c	442	p = ip_reass(p);
segundo	0:ac1725ba162c	443	/* packet not fully reassembled yet? */
segundo	0:ac1725ba162c	444	if (p == NULL) {
segundo	0:ac1725ba162c	445	return ERR_OK;
segundo	0:ac1725ba162c	446	}
segundo	0:ac1725ba162c	447	iphdr = (struct ip_hdr *)p->payload;
segundo	0:ac1725ba162c	448	#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
segundo	0:ac1725ba162c	449	pbuf_free(p);
segundo	0:ac1725ba162c	450	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
segundo	0:ac1725ba162c	451	ntohs(IPH_OFFSET(iphdr))));
segundo	0:ac1725ba162c	452	IP_STATS_INC(ip.opterr);
segundo	0:ac1725ba162c	453	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	454	/* unsupported protocol feature */
segundo	0:ac1725ba162c	455	snmp_inc_ipinunknownprotos();
segundo	0:ac1725ba162c	456	return ERR_OK;
segundo	0:ac1725ba162c	457	#endif /* IP_REASSEMBLY */
segundo	0:ac1725ba162c	458	}
segundo	0:ac1725ba162c	459
segundo	0:ac1725ba162c	460	#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
segundo	0:ac1725ba162c	461
segundo	0:ac1725ba162c	462	#if LWIP_IGMP
segundo	0:ac1725ba162c	463	/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
segundo	0:ac1725ba162c	464	if((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
segundo	0:ac1725ba162c	465	#else
segundo	0:ac1725ba162c	466	if (iphdr_hlen > IP_HLEN) {
segundo	0:ac1725ba162c	467	#endif /* LWIP_IGMP */
segundo	0:ac1725ba162c	468	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
segundo	0:ac1725ba162c	469	pbuf_free(p);
segundo	0:ac1725ba162c	470	IP_STATS_INC(ip.opterr);
segundo	0:ac1725ba162c	471	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	472	/* unsupported protocol feature */
segundo	0:ac1725ba162c	473	snmp_inc_ipinunknownprotos();
segundo	0:ac1725ba162c	474	return ERR_OK;
segundo	0:ac1725ba162c	475	}
segundo	0:ac1725ba162c	476	#endif /* IP_OPTIONS_ALLOWED == 0 */
segundo	0:ac1725ba162c	477
segundo	0:ac1725ba162c	478	/* send to upper layers */
segundo	0:ac1725ba162c	479	LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
segundo	0:ac1725ba162c	480	ip_debug_print(p);
segundo	0:ac1725ba162c	481	LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
segundo	0:ac1725ba162c	482
segundo	0:ac1725ba162c	483	current_netif = inp;
segundo	0:ac1725ba162c	484	current_header = iphdr;
segundo	0:ac1725ba162c	485
segundo	0:ac1725ba162c	486	#if LWIP_RAW
segundo	0:ac1725ba162c	487	/* raw input did not eat the packet? */
segundo	0:ac1725ba162c	488	if (raw_input(p, inp) == 0)
segundo	0:ac1725ba162c	489	#endif /* LWIP_RAW */
segundo	0:ac1725ba162c	490	{
segundo	0:ac1725ba162c	491
segundo	0:ac1725ba162c	492	switch (IPH_PROTO(iphdr)) {
segundo	0:ac1725ba162c	493	#if LWIP_UDP
segundo	0:ac1725ba162c	494	case IP_PROTO_UDP:
segundo	0:ac1725ba162c	495	#if LWIP_UDPLITE
segundo	0:ac1725ba162c	496	case IP_PROTO_UDPLITE:
segundo	0:ac1725ba162c	497	#endif /* LWIP_UDPLITE */
segundo	0:ac1725ba162c	498	snmp_inc_ipindelivers();
segundo	0:ac1725ba162c	499	udp_input(p, inp);
segundo	0:ac1725ba162c	500	break;
segundo	0:ac1725ba162c	501	#endif /* LWIP_UDP */
segundo	0:ac1725ba162c	502	#if LWIP_TCP
segundo	0:ac1725ba162c	503	case IP_PROTO_TCP:
segundo	0:ac1725ba162c	504	snmp_inc_ipindelivers();
segundo	0:ac1725ba162c	505	tcp_input(p, inp);
segundo	0:ac1725ba162c	506	break;
segundo	0:ac1725ba162c	507	#endif /* LWIP_TCP */
segundo	0:ac1725ba162c	508	#if LWIP_ICMP
segundo	0:ac1725ba162c	509	case IP_PROTO_ICMP:
segundo	0:ac1725ba162c	510	snmp_inc_ipindelivers();
segundo	0:ac1725ba162c	511	icmp_input(p, inp);
segundo	0:ac1725ba162c	512	break;
segundo	0:ac1725ba162c	513	#endif /* LWIP_ICMP */
segundo	0:ac1725ba162c	514	#if LWIP_IGMP
segundo	0:ac1725ba162c	515	case IP_PROTO_IGMP:
segundo	0:ac1725ba162c	516	igmp_input(p, inp, &current_iphdr_dest);
segundo	0:ac1725ba162c	517	break;
segundo	0:ac1725ba162c	518	#endif /* LWIP_IGMP */
segundo	0:ac1725ba162c	519	default:
segundo	0:ac1725ba162c	520	#if LWIP_ICMP
segundo	0:ac1725ba162c	521	/* send ICMP destination protocol unreachable unless is was a broadcast */
segundo	0:ac1725ba162c	522	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp) &&
segundo	0:ac1725ba162c	523	!ip_addr_ismulticast(&current_iphdr_dest)) {
segundo	0:ac1725ba162c	524	p->payload = iphdr;
segundo	0:ac1725ba162c	525	icmp_dest_unreach(p, ICMP_DUR_PROTO);
segundo	0:ac1725ba162c	526	}
segundo	0:ac1725ba162c	527	#endif /* LWIP_ICMP */
segundo	0:ac1725ba162c	528	pbuf_free(p);
segundo	0:ac1725ba162c	529
segundo	0:ac1725ba162c	530	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
segundo	0:ac1725ba162c	531
segundo	0:ac1725ba162c	532	IP_STATS_INC(ip.proterr);
segundo	0:ac1725ba162c	533	IP_STATS_INC(ip.drop);
segundo	0:ac1725ba162c	534	snmp_inc_ipinunknownprotos();
segundo	0:ac1725ba162c	535	}
segundo	0:ac1725ba162c	536	}
segundo	0:ac1725ba162c	537
segundo	0:ac1725ba162c	538	current_netif = NULL;
segundo	0:ac1725ba162c	539	current_header = NULL;
segundo	0:ac1725ba162c	540	ip_addr_set_any(&current_iphdr_src);
segundo	0:ac1725ba162c	541	ip_addr_set_any(&current_iphdr_dest);
segundo	0:ac1725ba162c	542
segundo	0:ac1725ba162c	543	return ERR_OK;
segundo	0:ac1725ba162c	544	}
segundo	0:ac1725ba162c	545
segundo	0:ac1725ba162c	546	/**
segundo	0:ac1725ba162c	547	* Sends an IP packet on a network interface. This function constructs
segundo	0:ac1725ba162c	548	* the IP header and calculates the IP header checksum. If the source
segundo	0:ac1725ba162c	549	* IP address is NULL, the IP address of the outgoing network
segundo	0:ac1725ba162c	550	* interface is filled in as source address.
segundo	0:ac1725ba162c	551	* If the destination IP address is IP_HDRINCL, p is assumed to already
segundo	0:ac1725ba162c	552	* include an IP header and p->payload points to it instead of the data.
segundo	0:ac1725ba162c	553	*
segundo	0:ac1725ba162c	554	* @param p the packet to send (p->payload points to the data, e.g. next
segundo	0:ac1725ba162c	555	protocol header; if dest == IP_HDRINCL, p already includes an IP
segundo	0:ac1725ba162c	556	header and p->payload points to that IP header)
segundo	0:ac1725ba162c	557	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
segundo	0:ac1725ba162c	558	* IP address of the netif used to send is used as source address)
segundo	0:ac1725ba162c	559	* @param dest the destination IP address to send the packet to
segundo	0:ac1725ba162c	560	* @param ttl the TTL value to be set in the IP header
segundo	0:ac1725ba162c	561	* @param tos the TOS value to be set in the IP header
segundo	0:ac1725ba162c	562	* @param proto the PROTOCOL to be set in the IP header
segundo	0:ac1725ba162c	563	* @param netif the netif on which to send this packet
segundo	0:ac1725ba162c	564	* @return ERR_OK if the packet was sent OK
segundo	0:ac1725ba162c	565	* ERR_BUF if p doesn't have enough space for IP/LINK headers
segundo	0:ac1725ba162c	566	* returns errors returned by netif->output
segundo	0:ac1725ba162c	567	*
segundo	0:ac1725ba162c	568	* @note ip_id: RFC791 "some host may be able to simply use
segundo	0:ac1725ba162c	569	* unique identifiers independent of destination"
segundo	0:ac1725ba162c	570	*/
segundo	0:ac1725ba162c	571	err_t
segundo	0:ac1725ba162c	572	ip_output_if(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
segundo	0:ac1725ba162c	573	u8_t ttl, u8_t tos,
segundo	0:ac1725ba162c	574	u8_t proto, struct netif *netif)
segundo	0:ac1725ba162c	575	{
segundo	0:ac1725ba162c	576	#if IP_OPTIONS_SEND
segundo	0:ac1725ba162c	577	return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
segundo	0:ac1725ba162c	578	}
segundo	0:ac1725ba162c	579
segundo	0:ac1725ba162c	580	/**
segundo	0:ac1725ba162c	581	* Same as ip_output_if() but with the possibility to include IP options:
segundo	0:ac1725ba162c	582	*
segundo	0:ac1725ba162c	583	* @ param ip_options pointer to the IP options, copied into the IP header
segundo	0:ac1725ba162c	584	* @ param optlen length of ip_options
segundo	0:ac1725ba162c	585	*/
segundo	0:ac1725ba162c	586	err_t ip_output_if_opt(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
segundo	0:ac1725ba162c	587	u8_t ttl, u8_t tos, u8_t proto, struct netif netif, void ip_options,
segundo	0:ac1725ba162c	588	u16_t optlen)
segundo	0:ac1725ba162c	589	{
segundo	0:ac1725ba162c	590	#endif /* IP_OPTIONS_SEND */
segundo	0:ac1725ba162c	591	struct ip_hdr *iphdr;
segundo	0:ac1725ba162c	592	ip_addr_t dest_addr;
segundo	0:ac1725ba162c	593	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	594	u32_t chk_sum = 0;
segundo	0:ac1725ba162c	595	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	596
segundo	0:ac1725ba162c	597	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
segundo	0:ac1725ba162c	598	gets altered as the packet is passed down the stack */
segundo	0:ac1725ba162c	599	LWIP_ASSERT("p->ref == 1", p->ref == 1);
segundo	0:ac1725ba162c	600
segundo	0:ac1725ba162c	601	snmp_inc_ipoutrequests();
segundo	0:ac1725ba162c	602
segundo	0:ac1725ba162c	603	/* Should the IP header be generated or is it already included in p? */
segundo	0:ac1725ba162c	604	if (dest != IP_HDRINCL) {
segundo	0:ac1725ba162c	605	u16_t ip_hlen = IP_HLEN;
segundo	0:ac1725ba162c	606	#if IP_OPTIONS_SEND
segundo	0:ac1725ba162c	607	u16_t optlen_aligned = 0;
segundo	0:ac1725ba162c	608	if (optlen != 0) {
segundo	0:ac1725ba162c	609	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	610	int i;
segundo	0:ac1725ba162c	611	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	612	/* round up to a multiple of 4 */
segundo	0:ac1725ba162c	613	optlen_aligned = ((optlen + 3) & ~3);
segundo	0:ac1725ba162c	614	ip_hlen += optlen_aligned;
segundo	0:ac1725ba162c	615	/* First write in the IP options */
segundo	0:ac1725ba162c	616	if (pbuf_header(p, optlen_aligned)) {
segundo	0:ac1725ba162c	617	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
segundo	0:ac1725ba162c	618	IP_STATS_INC(ip.err);
segundo	0:ac1725ba162c	619	snmp_inc_ipoutdiscards();
segundo	0:ac1725ba162c	620	return ERR_BUF;
segundo	0:ac1725ba162c	621	}
segundo	0:ac1725ba162c	622	MEMCPY(p->payload, ip_options, optlen);
segundo	0:ac1725ba162c	623	if (optlen < optlen_aligned) {
segundo	0:ac1725ba162c	624	/* zero the remaining bytes */
segundo	0:ac1725ba162c	625	memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
segundo	0:ac1725ba162c	626	}
segundo	0:ac1725ba162c	627	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	628	for (i = 0; i < optlen_aligned; i += sizeof(u16_t)) {
segundo	0:ac1725ba162c	629	chk_sum += ((u16_t*)p->payload)[i];
segundo	0:ac1725ba162c	630	}
segundo	0:ac1725ba162c	631	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	632	}
segundo	0:ac1725ba162c	633	#endif /* IP_OPTIONS_SEND */
segundo	0:ac1725ba162c	634	/* generate IP header */
segundo	0:ac1725ba162c	635	if (pbuf_header(p, IP_HLEN)) {
segundo	0:ac1725ba162c	636	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
segundo	0:ac1725ba162c	637
segundo	0:ac1725ba162c	638	IP_STATS_INC(ip.err);
segundo	0:ac1725ba162c	639	snmp_inc_ipoutdiscards();
segundo	0:ac1725ba162c	640	return ERR_BUF;
segundo	0:ac1725ba162c	641	}
segundo	0:ac1725ba162c	642
segundo	0:ac1725ba162c	643	iphdr = (struct ip_hdr *)p->payload;
segundo	0:ac1725ba162c	644	LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
segundo	0:ac1725ba162c	645	(p->len >= sizeof(struct ip_hdr)));
segundo	0:ac1725ba162c	646
segundo	0:ac1725ba162c	647	IPH_TTL_SET(iphdr, ttl);
segundo	0:ac1725ba162c	648	IPH_PROTO_SET(iphdr, proto);
segundo	0:ac1725ba162c	649	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	650	chk_sum += LWIP_MAKE_U16(proto, ttl);
segundo	0:ac1725ba162c	651	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	652
segundo	0:ac1725ba162c	653	/* dest cannot be NULL here */
segundo	0:ac1725ba162c	654	ip_addr_copy(iphdr->dest, *dest);
segundo	0:ac1725ba162c	655	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	656	chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
segundo	0:ac1725ba162c	657	chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
segundo	0:ac1725ba162c	658	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	659
segundo	0:ac1725ba162c	660	IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
segundo	0:ac1725ba162c	661	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	662	chk_sum += iphdr->_v_hl_tos;
segundo	0:ac1725ba162c	663	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	664	IPH_LEN_SET(iphdr, htons(p->tot_len));
segundo	0:ac1725ba162c	665	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	666	chk_sum += iphdr->_len;
segundo	0:ac1725ba162c	667	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	668	IPH_OFFSET_SET(iphdr, 0);
segundo	0:ac1725ba162c	669	IPH_ID_SET(iphdr, htons(ip_id));
segundo	0:ac1725ba162c	670	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	671	chk_sum += iphdr->_id;
segundo	0:ac1725ba162c	672	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	673	++ip_id;
segundo	0:ac1725ba162c	674
segundo	0:ac1725ba162c	675	if (ip_addr_isany(src)) {
segundo	0:ac1725ba162c	676	ip_addr_copy(iphdr->src, netif->ip_addr);
segundo	0:ac1725ba162c	677	} else {
segundo	0:ac1725ba162c	678	/* src cannot be NULL here */
segundo	0:ac1725ba162c	679	ip_addr_copy(iphdr->src, *src);
segundo	0:ac1725ba162c	680	}
segundo	0:ac1725ba162c	681
segundo	0:ac1725ba162c	682	#if CHECKSUM_GEN_IP_INLINE
segundo	0:ac1725ba162c	683	chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
segundo	0:ac1725ba162c	684	chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
segundo	0:ac1725ba162c	685	chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
segundo	0:ac1725ba162c	686	chk_sum = (chk_sum >> 16) + chk_sum;
segundo	0:ac1725ba162c	687	chk_sum = ~chk_sum;
segundo	0:ac1725ba162c	688	iphdr->_chksum = chk_sum; /* network order */
segundo	0:ac1725ba162c	689	#else /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	690	IPH_CHKSUM_SET(iphdr, 0);
segundo	0:ac1725ba162c	691	#if CHECKSUM_GEN_IP
segundo	0:ac1725ba162c	692	IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
segundo	0:ac1725ba162c	693	#endif
segundo	0:ac1725ba162c	694	#endif /* CHECKSUM_GEN_IP_INLINE */
segundo	0:ac1725ba162c	695	} else {
segundo	0:ac1725ba162c	696	/* IP header already included in p */
segundo	0:ac1725ba162c	697	iphdr = (struct ip_hdr *)p->payload;
segundo	0:ac1725ba162c	698	ip_addr_copy(dest_addr, iphdr->dest);
segundo	0:ac1725ba162c	699	dest = &dest_addr;
segundo	0:ac1725ba162c	700	}
segundo	0:ac1725ba162c	701
segundo	0:ac1725ba162c	702	IP_STATS_INC(ip.xmit);
segundo	0:ac1725ba162c	703
segundo	0:ac1725ba162c	704	LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
segundo	0:ac1725ba162c	705	ip_debug_print(p);
segundo	0:ac1725ba162c	706
segundo	0:ac1725ba162c	707	#if ENABLE_LOOPBACK
segundo	0:ac1725ba162c	708	if (ip_addr_cmp(dest, &netif->ip_addr)) {
segundo	0:ac1725ba162c	709	/* Packet to self, enqueue it for loopback */
segundo	0:ac1725ba162c	710	LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
segundo	0:ac1725ba162c	711	return netif_loop_output(netif, p, dest);
segundo	0:ac1725ba162c	712	}
segundo	0:ac1725ba162c	713	#if LWIP_IGMP
segundo	0:ac1725ba162c	714	if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
segundo	0:ac1725ba162c	715	netif_loop_output(netif, p, dest);
segundo	0:ac1725ba162c	716	}
segundo	0:ac1725ba162c	717	#endif /* LWIP_IGMP */
segundo	0:ac1725ba162c	718	#endif /* ENABLE_LOOPBACK */
segundo	0:ac1725ba162c	719	#if IP_FRAG
segundo	0:ac1725ba162c	720	/* don't fragment if interface has mtu set to 0 [loopif] */
segundo	0:ac1725ba162c	721	if (netif->mtu && (p->tot_len > netif->mtu)) {
segundo	0:ac1725ba162c	722	return ip_frag(p, netif, dest);
segundo	0:ac1725ba162c	723	}
segundo	0:ac1725ba162c	724	#endif /* IP_FRAG */
segundo	0:ac1725ba162c	725
segundo	0:ac1725ba162c	726	LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
segundo	0:ac1725ba162c	727	return netif->output(netif, p, dest);
segundo	0:ac1725ba162c	728	}
segundo	0:ac1725ba162c	729
segundo	0:ac1725ba162c	730	/**
segundo	0:ac1725ba162c	731	* Simple interface to ip_output_if. It finds the outgoing network
segundo	0:ac1725ba162c	732	* interface and calls upon ip_output_if to do the actual work.
segundo	0:ac1725ba162c	733	*
segundo	0:ac1725ba162c	734	* @param p the packet to send (p->payload points to the data, e.g. next
segundo	0:ac1725ba162c	735	protocol header; if dest == IP_HDRINCL, p already includes an IP
segundo	0:ac1725ba162c	736	header and p->payload points to that IP header)
segundo	0:ac1725ba162c	737	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
segundo	0:ac1725ba162c	738	* IP address of the netif used to send is used as source address)
segundo	0:ac1725ba162c	739	* @param dest the destination IP address to send the packet to
segundo	0:ac1725ba162c	740	* @param ttl the TTL value to be set in the IP header
segundo	0:ac1725ba162c	741	* @param tos the TOS value to be set in the IP header
segundo	0:ac1725ba162c	742	* @param proto the PROTOCOL to be set in the IP header
segundo	0:ac1725ba162c	743	*
segundo	0:ac1725ba162c	744	* @return ERR_RTE if no route is found
segundo	0:ac1725ba162c	745	* see ip_output_if() for more return values
segundo	0:ac1725ba162c	746	*/
segundo	0:ac1725ba162c	747	err_t
segundo	0:ac1725ba162c	748	ip_output(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
segundo	0:ac1725ba162c	749	u8_t ttl, u8_t tos, u8_t proto)
segundo	0:ac1725ba162c	750	{
segundo	0:ac1725ba162c	751	struct netif *netif;
segundo	0:ac1725ba162c	752
segundo	0:ac1725ba162c	753	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
segundo	0:ac1725ba162c	754	gets altered as the packet is passed down the stack */
segundo	0:ac1725ba162c	755	LWIP_ASSERT("p->ref == 1", p->ref == 1);
segundo	0:ac1725ba162c	756
segundo	0:ac1725ba162c	757	if ((netif = ip_route(dest)) == NULL) {
segundo	0:ac1725ba162c	758	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
segundo	0:ac1725ba162c	759	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
segundo	0:ac1725ba162c	760	IP_STATS_INC(ip.rterr);
segundo	0:ac1725ba162c	761	return ERR_RTE;
segundo	0:ac1725ba162c	762	}
segundo	0:ac1725ba162c	763
segundo	0:ac1725ba162c	764	return ip_output_if(p, src, dest, ttl, tos, proto, netif);
segundo	0:ac1725ba162c	765	}
segundo	0:ac1725ba162c	766
segundo	0:ac1725ba162c	767	#if LWIP_NETIF_HWADDRHINT
segundo	0:ac1725ba162c	768	/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
segundo	0:ac1725ba162c	769	* before calling ip_output_if.
segundo	0:ac1725ba162c	770	*
segundo	0:ac1725ba162c	771	* @param p the packet to send (p->payload points to the data, e.g. next
segundo	0:ac1725ba162c	772	protocol header; if dest == IP_HDRINCL, p already includes an IP
segundo	0:ac1725ba162c	773	header and p->payload points to that IP header)
segundo	0:ac1725ba162c	774	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
segundo	0:ac1725ba162c	775	* IP address of the netif used to send is used as source address)
segundo	0:ac1725ba162c	776	* @param dest the destination IP address to send the packet to
segundo	0:ac1725ba162c	777	* @param ttl the TTL value to be set in the IP header
segundo	0:ac1725ba162c	778	* @param tos the TOS value to be set in the IP header
segundo	0:ac1725ba162c	779	* @param proto the PROTOCOL to be set in the IP header
segundo	0:ac1725ba162c	780	* @param addr_hint address hint pointer set to netif->addr_hint before
segundo	0:ac1725ba162c	781	* calling ip_output_if()
segundo	0:ac1725ba162c	782	*
segundo	0:ac1725ba162c	783	* @return ERR_RTE if no route is found
segundo	0:ac1725ba162c	784	* see ip_output_if() for more return values
segundo	0:ac1725ba162c	785	*/
segundo	0:ac1725ba162c	786	err_t
segundo	0:ac1725ba162c	787	ip_output_hinted(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
segundo	0:ac1725ba162c	788	u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
segundo	0:ac1725ba162c	789	{
segundo	0:ac1725ba162c	790	struct netif *netif;
segundo	0:ac1725ba162c	791	err_t err;
segundo	0:ac1725ba162c	792
segundo	0:ac1725ba162c	793	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
segundo	0:ac1725ba162c	794	gets altered as the packet is passed down the stack */
segundo	0:ac1725ba162c	795	LWIP_ASSERT("p->ref == 1", p->ref == 1);
segundo	0:ac1725ba162c	796
segundo	0:ac1725ba162c	797	if ((netif = ip_route(dest)) == NULL) {
segundo	0:ac1725ba162c	798	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
segundo	0:ac1725ba162c	799	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
segundo	0:ac1725ba162c	800	IP_STATS_INC(ip.rterr);
segundo	0:ac1725ba162c	801	return ERR_RTE;
segundo	0:ac1725ba162c	802	}
segundo	0:ac1725ba162c	803
segundo	0:ac1725ba162c	804	netif->addr_hint = addr_hint;
segundo	0:ac1725ba162c	805	err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
segundo	0:ac1725ba162c	806	netif->addr_hint = NULL;
segundo	0:ac1725ba162c	807
segundo	0:ac1725ba162c	808	return err;
segundo	0:ac1725ba162c	809	}
segundo	0:ac1725ba162c	810	#endif /* LWIP_NETIF_HWADDRHINT*/
segundo	0:ac1725ba162c	811
segundo	0:ac1725ba162c	812	#if IP_DEBUG
segundo	0:ac1725ba162c	813	/* Print an IP header by using LWIP_DEBUGF
segundo	0:ac1725ba162c	814	* @param p an IP packet, p->payload pointing to the IP header
segundo	0:ac1725ba162c	815	*/
segundo	0:ac1725ba162c	816	void
segundo	0:ac1725ba162c	817	ip_debug_print(struct pbuf *p)
segundo	0:ac1725ba162c	818	{
segundo	0:ac1725ba162c	819	struct ip_hdr iphdr = (struct ip_hdr )p->payload;
segundo	0:ac1725ba162c	820	u8_t *payload;
segundo	0:ac1725ba162c	821
segundo	0:ac1725ba162c	822	payload = (u8_t *)iphdr + IP_HLEN;
segundo	0:ac1725ba162c	823
segundo	0:ac1725ba162c	824	LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
segundo	0:ac1725ba162c	825	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
segundo	0:ac1725ba162c	826	LWIP_DEBUGF(IP_DEBUG, ("\|%2"S16_F" \|%2"S16_F" \| 0x%02"X16_F" \| %5"U16_F" \| (v, hl, tos, len)\n",
segundo	0:ac1725ba162c	827	IPH_V(iphdr),
segundo	0:ac1725ba162c	828	IPH_HL(iphdr),
segundo	0:ac1725ba162c	829	IPH_TOS(iphdr),
segundo	0:ac1725ba162c	830	ntohs(IPH_LEN(iphdr))));
segundo	0:ac1725ba162c	831	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
segundo	0:ac1725ba162c	832	LWIP_DEBUGF(IP_DEBUG, ("\| %5"U16_F" \|%"U16_F"%"U16_F"%"U16_F"\| %4"U16_F" \| (id, flags, offset)\n",
segundo	0:ac1725ba162c	833	ntohs(IPH_ID(iphdr)),
segundo	0:ac1725ba162c	834	ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
segundo	0:ac1725ba162c	835	ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
segundo	0:ac1725ba162c	836	ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
segundo	0:ac1725ba162c	837	ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
segundo	0:ac1725ba162c	838	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
segundo	0:ac1725ba162c	839	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| 0x%04"X16_F" \| (ttl, proto, chksum)\n",
segundo	0:ac1725ba162c	840	IPH_TTL(iphdr),
segundo	0:ac1725ba162c	841	IPH_PROTO(iphdr),
segundo	0:ac1725ba162c	842	ntohs(IPH_CHKSUM(iphdr))));
segundo	0:ac1725ba162c	843	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
segundo	0:ac1725ba162c	844	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (src)\n",
segundo	0:ac1725ba162c	845	ip4_addr1_16(&iphdr->src),
segundo	0:ac1725ba162c	846	ip4_addr2_16(&iphdr->src),
segundo	0:ac1725ba162c	847	ip4_addr3_16(&iphdr->src),
segundo	0:ac1725ba162c	848	ip4_addr4_16(&iphdr->src)));
segundo	0:ac1725ba162c	849	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
segundo	0:ac1725ba162c	850	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (dest)\n",
segundo	0:ac1725ba162c	851	ip4_addr1_16(&iphdr->dest),
segundo	0:ac1725ba162c	852	ip4_addr2_16(&iphdr->dest),
segundo	0:ac1725ba162c	853	ip4_addr3_16(&iphdr->dest),
segundo	0:ac1725ba162c	854	ip4_addr4_16(&iphdr->dest)));
segundo	0:ac1725ba162c	855	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
segundo	0:ac1725ba162c	856	}
segundo	0:ac1725ba162c	857	#endif /* IP_DEBUG */

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Type:	Library
Created:	09 Nov 2010
Imports:	3034
Forks:	1
Commits:	8
Dependents:	42
Dependencies:	0
Followers:	27

lwip/core/ipv4/ip.c@0:ac1725ba162c, 2010-11-09 (annotated)

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