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NetTribute library with debug turned on in FShandler Donatien Garner -> Segundo Equipo -> this version

lwip/core/ipv4/ip.c@0:281d6ff68967, 2010-11-19 (annotated)

Committer:: hexley
Date:: Fri Nov 19 01:54:45 2010 +0000
Revision:: 0:281d6ff68967

Who changed what in which revision?

User	Revision	Line number	New contents of line
hexley	0:281d6ff68967	1	/**
hexley	0:281d6ff68967	2	* @file
hexley	0:281d6ff68967	3	* This is the IPv4 layer implementation for incoming and outgoing IP traffic.
hexley	0:281d6ff68967	4	*
hexley	0:281d6ff68967	5	* @see ip_frag.c
hexley	0:281d6ff68967	6	*
hexley	0:281d6ff68967	7	*/
hexley	0:281d6ff68967	8
hexley	0:281d6ff68967	9	/*
hexley	0:281d6ff68967	10	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
hexley	0:281d6ff68967	11	* All rights reserved.
hexley	0:281d6ff68967	12	*
hexley	0:281d6ff68967	13	* Redistribution and use in source and binary forms, with or without modification,
hexley	0:281d6ff68967	14	* are permitted provided that the following conditions are met:
hexley	0:281d6ff68967	15	*
hexley	0:281d6ff68967	16	* 1. Redistributions of source code must retain the above copyright notice,
hexley	0:281d6ff68967	17	* this list of conditions and the following disclaimer.
hexley	0:281d6ff68967	18	* 2. Redistributions in binary form must reproduce the above copyright notice,
hexley	0:281d6ff68967	19	* this list of conditions and the following disclaimer in the documentation
hexley	0:281d6ff68967	20	* and/or other materials provided with the distribution.
hexley	0:281d6ff68967	21	* 3. The name of the author may not be used to endorse or promote products
hexley	0:281d6ff68967	22	* derived from this software without specific prior written permission.
hexley	0:281d6ff68967	23	*
hexley	0:281d6ff68967	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
hexley	0:281d6ff68967	25	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
hexley	0:281d6ff68967	26	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
hexley	0:281d6ff68967	27	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
hexley	0:281d6ff68967	28	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
hexley	0:281d6ff68967	29	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
hexley	0:281d6ff68967	30	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
hexley	0:281d6ff68967	31	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
hexley	0:281d6ff68967	32	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
hexley	0:281d6ff68967	33	* OF SUCH DAMAGE.
hexley	0:281d6ff68967	34	*
hexley	0:281d6ff68967	35	* This file is part of the lwIP TCP/IP stack.
hexley	0:281d6ff68967	36	*
hexley	0:281d6ff68967	37	* Author: Adam Dunkels <adam@sics.se>
hexley	0:281d6ff68967	38	*
hexley	0:281d6ff68967	39	*/
hexley	0:281d6ff68967	40
hexley	0:281d6ff68967	41	#include "lwip/opt.h"
hexley	0:281d6ff68967	42	#include "lwip/ip.h"
hexley	0:281d6ff68967	43	#include "lwip/def.h"
hexley	0:281d6ff68967	44	#include "lwip/mem.h"
hexley	0:281d6ff68967	45	#include "lwip/ip_frag.h"
hexley	0:281d6ff68967	46	#include "lwip/inet_chksum.h"
hexley	0:281d6ff68967	47	#include "lwip/netif.h"
hexley	0:281d6ff68967	48	#include "lwip/icmp.h"
hexley	0:281d6ff68967	49	#include "lwip/igmp.h"
hexley	0:281d6ff68967	50	#include "lwip/raw.h"
hexley	0:281d6ff68967	51	#include "lwip/udp.h"
hexley	0:281d6ff68967	52	#include "lwip/tcp_impl.h"
hexley	0:281d6ff68967	53	#include "lwip/snmp.h"
hexley	0:281d6ff68967	54	#include "lwip/dhcp.h"
hexley	0:281d6ff68967	55	#include "lwip/autoip.h"
hexley	0:281d6ff68967	56	#include "lwip/stats.h"
hexley	0:281d6ff68967	57	#include "arch/perf.h"
hexley	0:281d6ff68967	58
hexley	0:281d6ff68967	59	#include <string.h>
hexley	0:281d6ff68967	60
hexley	0:281d6ff68967	61	/** Set this to 0 in the rare case of wanting to call an extra function to
hexley	0:281d6ff68967	62	* generate the IP checksum (in contrast to calculating it on-the-fly). */
hexley	0:281d6ff68967	63	#ifndef LWIP_INLINE_IP_CHKSUM
hexley	0:281d6ff68967	64	#define LWIP_INLINE_IP_CHKSUM 1
hexley	0:281d6ff68967	65	#endif
hexley	0:281d6ff68967	66	#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
hexley	0:281d6ff68967	67	#define CHECKSUM_GEN_IP_INLINE 1
hexley	0:281d6ff68967	68	#else
hexley	0:281d6ff68967	69	#define CHECKSUM_GEN_IP_INLINE 0
hexley	0:281d6ff68967	70	#endif
hexley	0:281d6ff68967	71
hexley	0:281d6ff68967	72	#if LWIP_DHCP \|\| defined(LWIP_IP_ACCEPT_UDP_PORT)
hexley	0:281d6ff68967	73	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
hexley	0:281d6ff68967	74
hexley	0:281d6ff68967	75	/** Some defines for DHCP to let link-layer-addressed packets through while the
hexley	0:281d6ff68967	76	* netif is down.
hexley	0:281d6ff68967	77	* To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT
hexley	0:281d6ff68967	78	* to return 1 if the port is accepted and 0 if the port is not accepted.
hexley	0:281d6ff68967	79	*/
hexley	0:281d6ff68967	80	#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
hexley	0:281d6ff68967	81	/* accept DHCP client port and custom port */
hexley	0:281d6ff68967	82	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(DHCP_CLIENT_PORT)) \
hexley	0:281d6ff68967	83	\|\| (LWIP_IP_ACCEPT_UDP_PORT(port)))
hexley	0:281d6ff68967	84	#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
hexley	0:281d6ff68967	85	/* accept custom port only */
hexley	0:281d6ff68967	86	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(dst_port))
hexley	0:281d6ff68967	87	#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
hexley	0:281d6ff68967	88	/* accept DHCP client port only */
hexley	0:281d6ff68967	89	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(DHCP_CLIENT_PORT))
hexley	0:281d6ff68967	90	#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
hexley	0:281d6ff68967	91
hexley	0:281d6ff68967	92	#else /* LWIP_DHCP */
hexley	0:281d6ff68967	93	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
hexley	0:281d6ff68967	94	#endif /* LWIP_DHCP */
hexley	0:281d6ff68967	95
hexley	0:281d6ff68967	96	/**
hexley	0:281d6ff68967	97	* The interface that provided the packet for the current callback
hexley	0:281d6ff68967	98	* invocation.
hexley	0:281d6ff68967	99	*/
hexley	0:281d6ff68967	100	struct netif *current_netif;
hexley	0:281d6ff68967	101
hexley	0:281d6ff68967	102	/**
hexley	0:281d6ff68967	103	* Header of the input packet currently being processed.
hexley	0:281d6ff68967	104	*/
hexley	0:281d6ff68967	105	const struct ip_hdr *current_header;
hexley	0:281d6ff68967	106	/** Source IP address of current_header */
hexley	0:281d6ff68967	107	ip_addr_t current_iphdr_src;
hexley	0:281d6ff68967	108	/** Destination IP address of current_header */
hexley	0:281d6ff68967	109	ip_addr_t current_iphdr_dest;
hexley	0:281d6ff68967	110
hexley	0:281d6ff68967	111	/** The IP header ID of the next outgoing IP packet */
hexley	0:281d6ff68967	112	static u16_t ip_id;
hexley	0:281d6ff68967	113
hexley	0:281d6ff68967	114	/**
hexley	0:281d6ff68967	115	* Finds the appropriate network interface for a given IP address. It
hexley	0:281d6ff68967	116	* searches the list of network interfaces linearly. A match is found
hexley	0:281d6ff68967	117	* if the masked IP address of the network interface equals the masked
hexley	0:281d6ff68967	118	* IP address given to the function.
hexley	0:281d6ff68967	119	*
hexley	0:281d6ff68967	120	* @param dest the destination IP address for which to find the route
hexley	0:281d6ff68967	121	* @return the netif on which to send to reach dest
hexley	0:281d6ff68967	122	*/
hexley	0:281d6ff68967	123	struct netif *
hexley	0:281d6ff68967	124	ip_route(ip_addr_t *dest)
hexley	0:281d6ff68967	125	{
hexley	0:281d6ff68967	126	struct netif *netif;
hexley	0:281d6ff68967	127
hexley	0:281d6ff68967	128	/* iterate through netifs */
hexley	0:281d6ff68967	129	for(netif = netif_list; netif != NULL; netif = netif->next) {
hexley	0:281d6ff68967	130	/* network mask matches? */
hexley	0:281d6ff68967	131	if (netif_is_up(netif)) {
hexley	0:281d6ff68967	132	if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
hexley	0:281d6ff68967	133	/* return netif on which to forward IP packet */
hexley	0:281d6ff68967	134	return netif;
hexley	0:281d6ff68967	135	}
hexley	0:281d6ff68967	136	}
hexley	0:281d6ff68967	137	}
hexley	0:281d6ff68967	138	if ((netif_default == NULL) \|\| (!netif_is_up(netif_default))) {
hexley	0:281d6ff68967	139	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
hexley	0:281d6ff68967	140	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
hexley	0:281d6ff68967	141	IP_STATS_INC(ip.rterr);
hexley	0:281d6ff68967	142	snmp_inc_ipoutnoroutes();
hexley	0:281d6ff68967	143	return NULL;
hexley	0:281d6ff68967	144	}
hexley	0:281d6ff68967	145	/* no matching netif found, use default netif */
hexley	0:281d6ff68967	146	return netif_default;
hexley	0:281d6ff68967	147	}
hexley	0:281d6ff68967	148
hexley	0:281d6ff68967	149	#if IP_FORWARD
hexley	0:281d6ff68967	150	/**
hexley	0:281d6ff68967	151	* Forwards an IP packet. It finds an appropriate route for the
hexley	0:281d6ff68967	152	* packet, decrements the TTL value of the packet, adjusts the
hexley	0:281d6ff68967	153	* checksum and outputs the packet on the appropriate interface.
hexley	0:281d6ff68967	154	*
hexley	0:281d6ff68967	155	* @param p the packet to forward (p->payload points to IP header)
hexley	0:281d6ff68967	156	* @param iphdr the IP header of the input packet
hexley	0:281d6ff68967	157	* @param inp the netif on which this packet was received
hexley	0:281d6ff68967	158	*/
hexley	0:281d6ff68967	159	static void
hexley	0:281d6ff68967	160	ip_forward(struct pbuf p, struct ip_hdr iphdr, struct netif *inp)
hexley	0:281d6ff68967	161	{
hexley	0:281d6ff68967	162	struct netif *netif;
hexley	0:281d6ff68967	163
hexley	0:281d6ff68967	164	PERF_START;
hexley	0:281d6ff68967	165
hexley	0:281d6ff68967	166	/* RFC3927 2.7: do not forward link-local addresses */
hexley	0:281d6ff68967	167	if (ip_addr_islinklocal(&current_iphdr_dest)) {
hexley	0:281d6ff68967	168	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
hexley	0:281d6ff68967	169	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
hexley	0:281d6ff68967	170	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
hexley	0:281d6ff68967	171	goto return_noroute;
hexley	0:281d6ff68967	172	}
hexley	0:281d6ff68967	173
hexley	0:281d6ff68967	174	/* Find network interface where to forward this IP packet to. */
hexley	0:281d6ff68967	175	netif = ip_route(&current_iphdr_dest);
hexley	0:281d6ff68967	176	if (netif == NULL) {
hexley	0:281d6ff68967	177	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
hexley	0:281d6ff68967	178	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
hexley	0:281d6ff68967	179	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
hexley	0:281d6ff68967	180	goto return_noroute;
hexley	0:281d6ff68967	181	}
hexley	0:281d6ff68967	182	/* Do not forward packets onto the same network interface on which
hexley	0:281d6ff68967	183	* they arrived. */
hexley	0:281d6ff68967	184	if (netif == inp) {
hexley	0:281d6ff68967	185	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
hexley	0:281d6ff68967	186	goto return_noroute;
hexley	0:281d6ff68967	187	}
hexley	0:281d6ff68967	188
hexley	0:281d6ff68967	189	/* decrement TTL */
hexley	0:281d6ff68967	190	IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
hexley	0:281d6ff68967	191	/* send ICMP if TTL == 0 */
hexley	0:281d6ff68967	192	if (IPH_TTL(iphdr) == 0) {
hexley	0:281d6ff68967	193	snmp_inc_ipinhdrerrors();
hexley	0:281d6ff68967	194	#if LWIP_ICMP
hexley	0:281d6ff68967	195	/* Don't send ICMP messages in response to ICMP messages */
hexley	0:281d6ff68967	196	if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
hexley	0:281d6ff68967	197	icmp_time_exceeded(p, ICMP_TE_TTL);
hexley	0:281d6ff68967	198	}
hexley	0:281d6ff68967	199	#endif /* LWIP_ICMP */
hexley	0:281d6ff68967	200	return;
hexley	0:281d6ff68967	201	}
hexley	0:281d6ff68967	202
hexley	0:281d6ff68967	203	/* Incrementally update the IP checksum. */
hexley	0:281d6ff68967	204	if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffff - 0x100)) {
hexley	0:281d6ff68967	205	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
hexley	0:281d6ff68967	206	} else {
hexley	0:281d6ff68967	207	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
hexley	0:281d6ff68967	208	}
hexley	0:281d6ff68967	209
hexley	0:281d6ff68967	210	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
hexley	0:281d6ff68967	211	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
hexley	0:281d6ff68967	212	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
hexley	0:281d6ff68967	213
hexley	0:281d6ff68967	214	IP_STATS_INC(ip.fw);
hexley	0:281d6ff68967	215	IP_STATS_INC(ip.xmit);
hexley	0:281d6ff68967	216	snmp_inc_ipforwdatagrams();
hexley	0:281d6ff68967	217
hexley	0:281d6ff68967	218	PERF_STOP("ip_forward");
hexley	0:281d6ff68967	219	/* transmit pbuf on chosen interface */
hexley	0:281d6ff68967	220	netif->output(netif, p, &current_iphdr_dest);
hexley	0:281d6ff68967	221	return;
hexley	0:281d6ff68967	222	return_noroute:
hexley	0:281d6ff68967	223	snmp_inc_ipoutnoroutes();
hexley	0:281d6ff68967	224	}
hexley	0:281d6ff68967	225	#endif /* IP_FORWARD */
hexley	0:281d6ff68967	226
hexley	0:281d6ff68967	227	/**
hexley	0:281d6ff68967	228	* This function is called by the network interface device driver when
hexley	0:281d6ff68967	229	* an IP packet is received. The function does the basic checks of the
hexley	0:281d6ff68967	230	* IP header such as packet size being at least larger than the header
hexley	0:281d6ff68967	231	* size etc. If the packet was not destined for us, the packet is
hexley	0:281d6ff68967	232	* forwarded (using ip_forward). The IP checksum is always checked.
hexley	0:281d6ff68967	233	*
hexley	0:281d6ff68967	234	* Finally, the packet is sent to the upper layer protocol input function.
hexley	0:281d6ff68967	235	*
hexley	0:281d6ff68967	236	* @param p the received IP packet (p->payload points to IP header)
hexley	0:281d6ff68967	237	* @param inp the netif on which this packet was received
hexley	0:281d6ff68967	238	* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
hexley	0:281d6ff68967	239	* processed, but currently always returns ERR_OK)
hexley	0:281d6ff68967	240	*/
hexley	0:281d6ff68967	241	err_t
hexley	0:281d6ff68967	242	ip_input(struct pbuf p, struct netif inp)
hexley	0:281d6ff68967	243	{
hexley	0:281d6ff68967	244	struct ip_hdr *iphdr;
hexley	0:281d6ff68967	245	struct netif *netif;
hexley	0:281d6ff68967	246	u16_t iphdr_hlen;
hexley	0:281d6ff68967	247	u16_t iphdr_len;
hexley	0:281d6ff68967	248	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
hexley	0:281d6ff68967	249	int check_ip_src=1;
hexley	0:281d6ff68967	250	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
hexley	0:281d6ff68967	251
hexley	0:281d6ff68967	252	IP_STATS_INC(ip.recv);
hexley	0:281d6ff68967	253	snmp_inc_ipinreceives();
hexley	0:281d6ff68967	254
hexley	0:281d6ff68967	255	/* identify the IP header */
hexley	0:281d6ff68967	256	iphdr = (struct ip_hdr *)p->payload;
hexley	0:281d6ff68967	257	if (IPH_V(iphdr) != 4) {
hexley	0:281d6ff68967	258	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
hexley	0:281d6ff68967	259	ip_debug_print(p);
hexley	0:281d6ff68967	260	pbuf_free(p);
hexley	0:281d6ff68967	261	IP_STATS_INC(ip.err);
hexley	0:281d6ff68967	262	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	263	snmp_inc_ipinhdrerrors();
hexley	0:281d6ff68967	264	return ERR_OK;
hexley	0:281d6ff68967	265	}
hexley	0:281d6ff68967	266
hexley	0:281d6ff68967	267	/* obtain IP header length in number of 32-bit words */
hexley	0:281d6ff68967	268	iphdr_hlen = IPH_HL(iphdr);
hexley	0:281d6ff68967	269	/* calculate IP header length in bytes */
hexley	0:281d6ff68967	270	iphdr_hlen *= 4;
hexley	0:281d6ff68967	271	/* obtain ip length in bytes */
hexley	0:281d6ff68967	272	iphdr_len = ntohs(IPH_LEN(iphdr));
hexley	0:281d6ff68967	273
hexley	0:281d6ff68967	274	/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
hexley	0:281d6ff68967	275	if ((iphdr_hlen > p->len) \|\| (iphdr_len > p->tot_len)) {
hexley	0:281d6ff68967	276	if (iphdr_hlen > p->len) {
hexley	0:281d6ff68967	277	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
hexley	0:281d6ff68967	278	("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
hexley	0:281d6ff68967	279	iphdr_hlen, p->len));
hexley	0:281d6ff68967	280	}
hexley	0:281d6ff68967	281	if (iphdr_len > p->tot_len) {
hexley	0:281d6ff68967	282	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
hexley	0:281d6ff68967	283	("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
hexley	0:281d6ff68967	284	iphdr_len, p->tot_len));
hexley	0:281d6ff68967	285	}
hexley	0:281d6ff68967	286	/* free (drop) packet pbufs */
hexley	0:281d6ff68967	287	pbuf_free(p);
hexley	0:281d6ff68967	288	IP_STATS_INC(ip.lenerr);
hexley	0:281d6ff68967	289	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	290	snmp_inc_ipindiscards();
hexley	0:281d6ff68967	291	return ERR_OK;
hexley	0:281d6ff68967	292	}
hexley	0:281d6ff68967	293
hexley	0:281d6ff68967	294	/* verify checksum */
hexley	0:281d6ff68967	295	#if CHECKSUM_CHECK_IP
hexley	0:281d6ff68967	296	if (inet_chksum(iphdr, iphdr_hlen) != 0) {
hexley	0:281d6ff68967	297
hexley	0:281d6ff68967	298	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
hexley	0:281d6ff68967	299	("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
hexley	0:281d6ff68967	300	ip_debug_print(p);
hexley	0:281d6ff68967	301	pbuf_free(p);
hexley	0:281d6ff68967	302	IP_STATS_INC(ip.chkerr);
hexley	0:281d6ff68967	303	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	304	snmp_inc_ipinhdrerrors();
hexley	0:281d6ff68967	305	return ERR_OK;
hexley	0:281d6ff68967	306	}
hexley	0:281d6ff68967	307	#endif
hexley	0:281d6ff68967	308
hexley	0:281d6ff68967	309	/* Trim pbuf. This should have been done at the netif layer,
hexley	0:281d6ff68967	310	* but we'll do it anyway just to be sure that its done. */
hexley	0:281d6ff68967	311	pbuf_realloc(p, iphdr_len);
hexley	0:281d6ff68967	312
hexley	0:281d6ff68967	313	/* copy IP addresses to aligned ip_addr_t */
hexley	0:281d6ff68967	314	ip_addr_copy(current_iphdr_dest, iphdr->dest);
hexley	0:281d6ff68967	315	ip_addr_copy(current_iphdr_src, iphdr->src);
hexley	0:281d6ff68967	316
hexley	0:281d6ff68967	317	/* match packet against an interface, i.e. is this packet for us? */
hexley	0:281d6ff68967	318	#if LWIP_IGMP
hexley	0:281d6ff68967	319	if (ip_addr_ismulticast(&current_iphdr_dest)) {
hexley	0:281d6ff68967	320	if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &current_iphdr_dest))) {
hexley	0:281d6ff68967	321	netif = inp;
hexley	0:281d6ff68967	322	} else {
hexley	0:281d6ff68967	323	netif = NULL;
hexley	0:281d6ff68967	324	}
hexley	0:281d6ff68967	325	} else
hexley	0:281d6ff68967	326	#endif /* LWIP_IGMP */
hexley	0:281d6ff68967	327	{
hexley	0:281d6ff68967	328	/* start trying with inp. if that's not acceptable, start walking the
hexley	0:281d6ff68967	329	list of configured netifs.
hexley	0:281d6ff68967	330	'first' is used as a boolean to mark whether we started walking the list */
hexley	0:281d6ff68967	331	int first = 1;
hexley	0:281d6ff68967	332	netif = inp;
hexley	0:281d6ff68967	333	do {
hexley	0:281d6ff68967	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",
hexley	0:281d6ff68967	335	ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
hexley	0:281d6ff68967	336	ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
hexley	0:281d6ff68967	337	ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
hexley	0:281d6ff68967	338	ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
hexley	0:281d6ff68967	339
hexley	0:281d6ff68967	340	/* interface is up and configured? */
hexley	0:281d6ff68967	341	if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
hexley	0:281d6ff68967	342	/* unicast to this interface address? */
hexley	0:281d6ff68967	343	if (ip_addr_cmp(&current_iphdr_dest, &(netif->ip_addr)) \|\|
hexley	0:281d6ff68967	344	/* or broadcast on this interface network address? */
hexley	0:281d6ff68967	345	ip_addr_isbroadcast(&current_iphdr_dest, netif)) {
hexley	0:281d6ff68967	346	LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
hexley	0:281d6ff68967	347	netif->name[0], netif->name[1]));
hexley	0:281d6ff68967	348	/* break out of for loop */
hexley	0:281d6ff68967	349	break;
hexley	0:281d6ff68967	350	}
hexley	0:281d6ff68967	351	#if LWIP_AUTOIP
hexley	0:281d6ff68967	352	/* connections to link-local addresses must persist after changing
hexley	0:281d6ff68967	353	the netif's address (RFC3927 ch. 1.9) */
hexley	0:281d6ff68967	354	if ((netif->autoip != NULL) &&
hexley	0:281d6ff68967	355	ip_addr_cmp(&current_iphdr_dest, &(netif->autoip->llipaddr))) {
hexley	0:281d6ff68967	356	LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
hexley	0:281d6ff68967	357	netif->name[0], netif->name[1]));
hexley	0:281d6ff68967	358	/* break out of for loop */
hexley	0:281d6ff68967	359	break;
hexley	0:281d6ff68967	360	}
hexley	0:281d6ff68967	361	#endif /* LWIP_AUTOIP */
hexley	0:281d6ff68967	362	}
hexley	0:281d6ff68967	363	if (first) {
hexley	0:281d6ff68967	364	first = 0;
hexley	0:281d6ff68967	365	netif = netif_list;
hexley	0:281d6ff68967	366	} else {
hexley	0:281d6ff68967	367	netif = netif->next;
hexley	0:281d6ff68967	368	}
hexley	0:281d6ff68967	369	if (netif == inp) {
hexley	0:281d6ff68967	370	netif = netif->next;
hexley	0:281d6ff68967	371	}
hexley	0:281d6ff68967	372	} while(netif != NULL);
hexley	0:281d6ff68967	373	}
hexley	0:281d6ff68967	374
hexley	0:281d6ff68967	375	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
hexley	0:281d6ff68967	376	/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
hexley	0:281d6ff68967	377	* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
hexley	0:281d6ff68967	378	* According to RFC 1542 section 3.1.1, referred by RFC 2131).
hexley	0:281d6ff68967	379	*
hexley	0:281d6ff68967	380	* If you want to accept private broadcast communication while a netif is down,
hexley	0:281d6ff68967	381	* define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
hexley	0:281d6ff68967	382	*
hexley	0:281d6ff68967	383	* #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
hexley	0:281d6ff68967	384	*/
hexley	0:281d6ff68967	385	if (netif == NULL) {
hexley	0:281d6ff68967	386	/* remote port is DHCP server? */
hexley	0:281d6ff68967	387	if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
hexley	0:281d6ff68967	388	struct udp_hdr udphdr = (struct udp_hdr )((u8_t *)iphdr + iphdr_hlen);
hexley	0:281d6ff68967	389	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
hexley	0:281d6ff68967	390	ntohs(udphdr->dest)));
hexley	0:281d6ff68967	391	if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
hexley	0:281d6ff68967	392	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
hexley	0:281d6ff68967	393	netif = inp;
hexley	0:281d6ff68967	394	check_ip_src = 0;
hexley	0:281d6ff68967	395	}
hexley	0:281d6ff68967	396	}
hexley	0:281d6ff68967	397	}
hexley	0:281d6ff68967	398	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
hexley	0:281d6ff68967	399
hexley	0:281d6ff68967	400	/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
hexley	0:281d6ff68967	401	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
hexley	0:281d6ff68967	402	/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
hexley	0:281d6ff68967	403	if (check_ip_src && !ip_addr_isany(&current_iphdr_src))
hexley	0:281d6ff68967	404	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
hexley	0:281d6ff68967	405	{ if ((ip_addr_isbroadcast(&current_iphdr_src, inp)) \|\|
hexley	0:281d6ff68967	406	(ip_addr_ismulticast(&current_iphdr_src))) {
hexley	0:281d6ff68967	407	/* packet source is not valid */
hexley	0:281d6ff68967	408	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
hexley	0:281d6ff68967	409	/* free (drop) packet pbufs */
hexley	0:281d6ff68967	410	pbuf_free(p);
hexley	0:281d6ff68967	411	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	412	snmp_inc_ipinaddrerrors();
hexley	0:281d6ff68967	413	snmp_inc_ipindiscards();
hexley	0:281d6ff68967	414	return ERR_OK;
hexley	0:281d6ff68967	415	}
hexley	0:281d6ff68967	416	}
hexley	0:281d6ff68967	417
hexley	0:281d6ff68967	418	/* packet not for us? */
hexley	0:281d6ff68967	419	if (netif == NULL) {
hexley	0:281d6ff68967	420	/* packet not for us, route or discard */
hexley	0:281d6ff68967	421	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
hexley	0:281d6ff68967	422	#if IP_FORWARD
hexley	0:281d6ff68967	423	/* non-broadcast packet? */
hexley	0:281d6ff68967	424	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp)) {
hexley	0:281d6ff68967	425	/* try to forward IP packet on (other) interfaces */
hexley	0:281d6ff68967	426	ip_forward(p, iphdr, inp);
hexley	0:281d6ff68967	427	} else
hexley	0:281d6ff68967	428	#endif /* IP_FORWARD */
hexley	0:281d6ff68967	429	{
hexley	0:281d6ff68967	430	snmp_inc_ipinaddrerrors();
hexley	0:281d6ff68967	431	snmp_inc_ipindiscards();
hexley	0:281d6ff68967	432	}
hexley	0:281d6ff68967	433	pbuf_free(p);
hexley	0:281d6ff68967	434	return ERR_OK;
hexley	0:281d6ff68967	435	}
hexley	0:281d6ff68967	436	/* packet consists of multiple fragments? */
hexley	0:281d6ff68967	437	if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK \| IP_MF)) != 0) {
hexley	0:281d6ff68967	438	#if IP_REASSEMBLY /* packet fragment reassembly code present? */
hexley	0:281d6ff68967	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",
hexley	0:281d6ff68967	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));
hexley	0:281d6ff68967	441	/* reassemble the packet*/
hexley	0:281d6ff68967	442	p = ip_reass(p);
hexley	0:281d6ff68967	443	/* packet not fully reassembled yet? */
hexley	0:281d6ff68967	444	if (p == NULL) {
hexley	0:281d6ff68967	445	return ERR_OK;
hexley	0:281d6ff68967	446	}
hexley	0:281d6ff68967	447	iphdr = (struct ip_hdr *)p->payload;
hexley	0:281d6ff68967	448	#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
hexley	0:281d6ff68967	449	pbuf_free(p);
hexley	0:281d6ff68967	450	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
hexley	0:281d6ff68967	451	ntohs(IPH_OFFSET(iphdr))));
hexley	0:281d6ff68967	452	IP_STATS_INC(ip.opterr);
hexley	0:281d6ff68967	453	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	454	/* unsupported protocol feature */
hexley	0:281d6ff68967	455	snmp_inc_ipinunknownprotos();
hexley	0:281d6ff68967	456	return ERR_OK;
hexley	0:281d6ff68967	457	#endif /* IP_REASSEMBLY */
hexley	0:281d6ff68967	458	}
hexley	0:281d6ff68967	459
hexley	0:281d6ff68967	460	#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
hexley	0:281d6ff68967	461
hexley	0:281d6ff68967	462	#if LWIP_IGMP
hexley	0:281d6ff68967	463	/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
hexley	0:281d6ff68967	464	if((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
hexley	0:281d6ff68967	465	#else
hexley	0:281d6ff68967	466	if (iphdr_hlen > IP_HLEN) {
hexley	0:281d6ff68967	467	#endif /* LWIP_IGMP */
hexley	0:281d6ff68967	468	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
hexley	0:281d6ff68967	469	pbuf_free(p);
hexley	0:281d6ff68967	470	IP_STATS_INC(ip.opterr);
hexley	0:281d6ff68967	471	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	472	/* unsupported protocol feature */
hexley	0:281d6ff68967	473	snmp_inc_ipinunknownprotos();
hexley	0:281d6ff68967	474	return ERR_OK;
hexley	0:281d6ff68967	475	}
hexley	0:281d6ff68967	476	#endif /* IP_OPTIONS_ALLOWED == 0 */
hexley	0:281d6ff68967	477
hexley	0:281d6ff68967	478	/* send to upper layers */
hexley	0:281d6ff68967	479	LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
hexley	0:281d6ff68967	480	ip_debug_print(p);
hexley	0:281d6ff68967	481	LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
hexley	0:281d6ff68967	482
hexley	0:281d6ff68967	483	current_netif = inp;
hexley	0:281d6ff68967	484	current_header = iphdr;
hexley	0:281d6ff68967	485
hexley	0:281d6ff68967	486	#if LWIP_RAW
hexley	0:281d6ff68967	487	/* raw input did not eat the packet? */
hexley	0:281d6ff68967	488	if (raw_input(p, inp) == 0)
hexley	0:281d6ff68967	489	#endif /* LWIP_RAW */
hexley	0:281d6ff68967	490	{
hexley	0:281d6ff68967	491
hexley	0:281d6ff68967	492	switch (IPH_PROTO(iphdr)) {
hexley	0:281d6ff68967	493	#if LWIP_UDP
hexley	0:281d6ff68967	494	case IP_PROTO_UDP:
hexley	0:281d6ff68967	495	#if LWIP_UDPLITE
hexley	0:281d6ff68967	496	case IP_PROTO_UDPLITE:
hexley	0:281d6ff68967	497	#endif /* LWIP_UDPLITE */
hexley	0:281d6ff68967	498	snmp_inc_ipindelivers();
hexley	0:281d6ff68967	499	udp_input(p, inp);
hexley	0:281d6ff68967	500	break;
hexley	0:281d6ff68967	501	#endif /* LWIP_UDP */
hexley	0:281d6ff68967	502	#if LWIP_TCP
hexley	0:281d6ff68967	503	case IP_PROTO_TCP:
hexley	0:281d6ff68967	504	snmp_inc_ipindelivers();
hexley	0:281d6ff68967	505	tcp_input(p, inp);
hexley	0:281d6ff68967	506	break;
hexley	0:281d6ff68967	507	#endif /* LWIP_TCP */
hexley	0:281d6ff68967	508	#if LWIP_ICMP
hexley	0:281d6ff68967	509	case IP_PROTO_ICMP:
hexley	0:281d6ff68967	510	snmp_inc_ipindelivers();
hexley	0:281d6ff68967	511	icmp_input(p, inp);
hexley	0:281d6ff68967	512	break;
hexley	0:281d6ff68967	513	#endif /* LWIP_ICMP */
hexley	0:281d6ff68967	514	#if LWIP_IGMP
hexley	0:281d6ff68967	515	case IP_PROTO_IGMP:
hexley	0:281d6ff68967	516	igmp_input(p, inp, &current_iphdr_dest);
hexley	0:281d6ff68967	517	break;
hexley	0:281d6ff68967	518	#endif /* LWIP_IGMP */
hexley	0:281d6ff68967	519	default:
hexley	0:281d6ff68967	520	#if LWIP_ICMP
hexley	0:281d6ff68967	521	/* send ICMP destination protocol unreachable unless is was a broadcast */
hexley	0:281d6ff68967	522	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp) &&
hexley	0:281d6ff68967	523	!ip_addr_ismulticast(&current_iphdr_dest)) {
hexley	0:281d6ff68967	524	p->payload = iphdr;
hexley	0:281d6ff68967	525	icmp_dest_unreach(p, ICMP_DUR_PROTO);
hexley	0:281d6ff68967	526	}
hexley	0:281d6ff68967	527	#endif /* LWIP_ICMP */
hexley	0:281d6ff68967	528	pbuf_free(p);
hexley	0:281d6ff68967	529
hexley	0:281d6ff68967	530	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
hexley	0:281d6ff68967	531
hexley	0:281d6ff68967	532	IP_STATS_INC(ip.proterr);
hexley	0:281d6ff68967	533	IP_STATS_INC(ip.drop);
hexley	0:281d6ff68967	534	snmp_inc_ipinunknownprotos();
hexley	0:281d6ff68967	535	}
hexley	0:281d6ff68967	536	}
hexley	0:281d6ff68967	537
hexley	0:281d6ff68967	538	current_netif = NULL;
hexley	0:281d6ff68967	539	current_header = NULL;
hexley	0:281d6ff68967	540	ip_addr_set_any(&current_iphdr_src);
hexley	0:281d6ff68967	541	ip_addr_set_any(&current_iphdr_dest);
hexley	0:281d6ff68967	542
hexley	0:281d6ff68967	543	return ERR_OK;
hexley	0:281d6ff68967	544	}
hexley	0:281d6ff68967	545
hexley	0:281d6ff68967	546	/**
hexley	0:281d6ff68967	547	* Sends an IP packet on a network interface. This function constructs
hexley	0:281d6ff68967	548	* the IP header and calculates the IP header checksum. If the source
hexley	0:281d6ff68967	549	* IP address is NULL, the IP address of the outgoing network
hexley	0:281d6ff68967	550	* interface is filled in as source address.
hexley	0:281d6ff68967	551	* If the destination IP address is IP_HDRINCL, p is assumed to already
hexley	0:281d6ff68967	552	* include an IP header and p->payload points to it instead of the data.
hexley	0:281d6ff68967	553	*
hexley	0:281d6ff68967	554	* @param p the packet to send (p->payload points to the data, e.g. next
hexley	0:281d6ff68967	555	protocol header; if dest == IP_HDRINCL, p already includes an IP
hexley	0:281d6ff68967	556	header and p->payload points to that IP header)
hexley	0:281d6ff68967	557	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
hexley	0:281d6ff68967	558	* IP address of the netif used to send is used as source address)
hexley	0:281d6ff68967	559	* @param dest the destination IP address to send the packet to
hexley	0:281d6ff68967	560	* @param ttl the TTL value to be set in the IP header
hexley	0:281d6ff68967	561	* @param tos the TOS value to be set in the IP header
hexley	0:281d6ff68967	562	* @param proto the PROTOCOL to be set in the IP header
hexley	0:281d6ff68967	563	* @param netif the netif on which to send this packet
hexley	0:281d6ff68967	564	* @return ERR_OK if the packet was sent OK
hexley	0:281d6ff68967	565	* ERR_BUF if p doesn't have enough space for IP/LINK headers
hexley	0:281d6ff68967	566	* returns errors returned by netif->output
hexley	0:281d6ff68967	567	*
hexley	0:281d6ff68967	568	* @note ip_id: RFC791 "some host may be able to simply use
hexley	0:281d6ff68967	569	* unique identifiers independent of destination"
hexley	0:281d6ff68967	570	*/
hexley	0:281d6ff68967	571	err_t
hexley	0:281d6ff68967	572	ip_output_if(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
hexley	0:281d6ff68967	573	u8_t ttl, u8_t tos,
hexley	0:281d6ff68967	574	u8_t proto, struct netif *netif)
hexley	0:281d6ff68967	575	{
hexley	0:281d6ff68967	576	#if IP_OPTIONS_SEND
hexley	0:281d6ff68967	577	return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
hexley	0:281d6ff68967	578	}
hexley	0:281d6ff68967	579
hexley	0:281d6ff68967	580	/**
hexley	0:281d6ff68967	581	* Same as ip_output_if() but with the possibility to include IP options:
hexley	0:281d6ff68967	582	*
hexley	0:281d6ff68967	583	* @ param ip_options pointer to the IP options, copied into the IP header
hexley	0:281d6ff68967	584	* @ param optlen length of ip_options
hexley	0:281d6ff68967	585	*/
hexley	0:281d6ff68967	586	err_t ip_output_if_opt(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
hexley	0:281d6ff68967	587	u8_t ttl, u8_t tos, u8_t proto, struct netif netif, void ip_options,
hexley	0:281d6ff68967	588	u16_t optlen)
hexley	0:281d6ff68967	589	{
hexley	0:281d6ff68967	590	#endif /* IP_OPTIONS_SEND */
hexley	0:281d6ff68967	591	struct ip_hdr *iphdr;
hexley	0:281d6ff68967	592	ip_addr_t dest_addr;
hexley	0:281d6ff68967	593	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	594	u32_t chk_sum = 0;
hexley	0:281d6ff68967	595	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	596
hexley	0:281d6ff68967	597	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
hexley	0:281d6ff68967	598	gets altered as the packet is passed down the stack */
hexley	0:281d6ff68967	599	LWIP_ASSERT("p->ref == 1", p->ref == 1);
hexley	0:281d6ff68967	600
hexley	0:281d6ff68967	601	snmp_inc_ipoutrequests();
hexley	0:281d6ff68967	602
hexley	0:281d6ff68967	603	/* Should the IP header be generated or is it already included in p? */
hexley	0:281d6ff68967	604	if (dest != IP_HDRINCL) {
hexley	0:281d6ff68967	605	u16_t ip_hlen = IP_HLEN;
hexley	0:281d6ff68967	606	#if IP_OPTIONS_SEND
hexley	0:281d6ff68967	607	u16_t optlen_aligned = 0;
hexley	0:281d6ff68967	608	if (optlen != 0) {
hexley	0:281d6ff68967	609	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	610	int i;
hexley	0:281d6ff68967	611	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	612	/* round up to a multiple of 4 */
hexley	0:281d6ff68967	613	optlen_aligned = ((optlen + 3) & ~3);
hexley	0:281d6ff68967	614	ip_hlen += optlen_aligned;
hexley	0:281d6ff68967	615	/* First write in the IP options */
hexley	0:281d6ff68967	616	if (pbuf_header(p, optlen_aligned)) {
hexley	0:281d6ff68967	617	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
hexley	0:281d6ff68967	618	IP_STATS_INC(ip.err);
hexley	0:281d6ff68967	619	snmp_inc_ipoutdiscards();
hexley	0:281d6ff68967	620	return ERR_BUF;
hexley	0:281d6ff68967	621	}
hexley	0:281d6ff68967	622	MEMCPY(p->payload, ip_options, optlen);
hexley	0:281d6ff68967	623	if (optlen < optlen_aligned) {
hexley	0:281d6ff68967	624	/* zero the remaining bytes */
hexley	0:281d6ff68967	625	memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
hexley	0:281d6ff68967	626	}
hexley	0:281d6ff68967	627	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	628	for (i = 0; i < optlen_aligned; i += sizeof(u16_t)) {
hexley	0:281d6ff68967	629	chk_sum += ((u16_t*)p->payload)[i];
hexley	0:281d6ff68967	630	}
hexley	0:281d6ff68967	631	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	632	}
hexley	0:281d6ff68967	633	#endif /* IP_OPTIONS_SEND */
hexley	0:281d6ff68967	634	/* generate IP header */
hexley	0:281d6ff68967	635	if (pbuf_header(p, IP_HLEN)) {
hexley	0:281d6ff68967	636	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
hexley	0:281d6ff68967	637
hexley	0:281d6ff68967	638	IP_STATS_INC(ip.err);
hexley	0:281d6ff68967	639	snmp_inc_ipoutdiscards();
hexley	0:281d6ff68967	640	return ERR_BUF;
hexley	0:281d6ff68967	641	}
hexley	0:281d6ff68967	642
hexley	0:281d6ff68967	643	iphdr = (struct ip_hdr *)p->payload;
hexley	0:281d6ff68967	644	LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
hexley	0:281d6ff68967	645	(p->len >= sizeof(struct ip_hdr)));
hexley	0:281d6ff68967	646
hexley	0:281d6ff68967	647	IPH_TTL_SET(iphdr, ttl);
hexley	0:281d6ff68967	648	IPH_PROTO_SET(iphdr, proto);
hexley	0:281d6ff68967	649	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	650	chk_sum += LWIP_MAKE_U16(proto, ttl);
hexley	0:281d6ff68967	651	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	652
hexley	0:281d6ff68967	653	/* dest cannot be NULL here */
hexley	0:281d6ff68967	654	ip_addr_copy(iphdr->dest, *dest);
hexley	0:281d6ff68967	655	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	656	chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
hexley	0:281d6ff68967	657	chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
hexley	0:281d6ff68967	658	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	659
hexley	0:281d6ff68967	660	IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
hexley	0:281d6ff68967	661	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	662	chk_sum += iphdr->_v_hl_tos;
hexley	0:281d6ff68967	663	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	664	IPH_LEN_SET(iphdr, htons(p->tot_len));
hexley	0:281d6ff68967	665	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	666	chk_sum += iphdr->_len;
hexley	0:281d6ff68967	667	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	668	IPH_OFFSET_SET(iphdr, 0);
hexley	0:281d6ff68967	669	IPH_ID_SET(iphdr, htons(ip_id));
hexley	0:281d6ff68967	670	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	671	chk_sum += iphdr->_id;
hexley	0:281d6ff68967	672	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	673	++ip_id;
hexley	0:281d6ff68967	674
hexley	0:281d6ff68967	675	if (ip_addr_isany(src)) {
hexley	0:281d6ff68967	676	ip_addr_copy(iphdr->src, netif->ip_addr);
hexley	0:281d6ff68967	677	} else {
hexley	0:281d6ff68967	678	/* src cannot be NULL here */
hexley	0:281d6ff68967	679	ip_addr_copy(iphdr->src, *src);
hexley	0:281d6ff68967	680	}
hexley	0:281d6ff68967	681
hexley	0:281d6ff68967	682	#if CHECKSUM_GEN_IP_INLINE
hexley	0:281d6ff68967	683	chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
hexley	0:281d6ff68967	684	chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
hexley	0:281d6ff68967	685	chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
hexley	0:281d6ff68967	686	chk_sum = (chk_sum >> 16) + chk_sum;
hexley	0:281d6ff68967	687	chk_sum = ~chk_sum;
hexley	0:281d6ff68967	688	iphdr->_chksum = chk_sum; /* network order */
hexley	0:281d6ff68967	689	#else /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	690	IPH_CHKSUM_SET(iphdr, 0);
hexley	0:281d6ff68967	691	#if CHECKSUM_GEN_IP
hexley	0:281d6ff68967	692	IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
hexley	0:281d6ff68967	693	#endif
hexley	0:281d6ff68967	694	#endif /* CHECKSUM_GEN_IP_INLINE */
hexley	0:281d6ff68967	695	} else {
hexley	0:281d6ff68967	696	/* IP header already included in p */
hexley	0:281d6ff68967	697	iphdr = (struct ip_hdr *)p->payload;
hexley	0:281d6ff68967	698	ip_addr_copy(dest_addr, iphdr->dest);
hexley	0:281d6ff68967	699	dest = &dest_addr;
hexley	0:281d6ff68967	700	}
hexley	0:281d6ff68967	701
hexley	0:281d6ff68967	702	IP_STATS_INC(ip.xmit);
hexley	0:281d6ff68967	703
hexley	0:281d6ff68967	704	LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
hexley	0:281d6ff68967	705	ip_debug_print(p);
hexley	0:281d6ff68967	706
hexley	0:281d6ff68967	707	#if ENABLE_LOOPBACK
hexley	0:281d6ff68967	708	if (ip_addr_cmp(dest, &netif->ip_addr)) {
hexley	0:281d6ff68967	709	/* Packet to self, enqueue it for loopback */
hexley	0:281d6ff68967	710	LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
hexley	0:281d6ff68967	711	return netif_loop_output(netif, p, dest);
hexley	0:281d6ff68967	712	}
hexley	0:281d6ff68967	713	#if LWIP_IGMP
hexley	0:281d6ff68967	714	if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
hexley	0:281d6ff68967	715	netif_loop_output(netif, p, dest);
hexley	0:281d6ff68967	716	}
hexley	0:281d6ff68967	717	#endif /* LWIP_IGMP */
hexley	0:281d6ff68967	718	#endif /* ENABLE_LOOPBACK */
hexley	0:281d6ff68967	719	#if IP_FRAG
hexley	0:281d6ff68967	720	/* don't fragment if interface has mtu set to 0 [loopif] */
hexley	0:281d6ff68967	721	if (netif->mtu && (p->tot_len > netif->mtu)) {
hexley	0:281d6ff68967	722	return ip_frag(p, netif, dest);
hexley	0:281d6ff68967	723	}
hexley	0:281d6ff68967	724	#endif /* IP_FRAG */
hexley	0:281d6ff68967	725
hexley	0:281d6ff68967	726	LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
hexley	0:281d6ff68967	727	return netif->output(netif, p, dest);
hexley	0:281d6ff68967	728	}
hexley	0:281d6ff68967	729
hexley	0:281d6ff68967	730	/**
hexley	0:281d6ff68967	731	* Simple interface to ip_output_if. It finds the outgoing network
hexley	0:281d6ff68967	732	* interface and calls upon ip_output_if to do the actual work.
hexley	0:281d6ff68967	733	*
hexley	0:281d6ff68967	734	* @param p the packet to send (p->payload points to the data, e.g. next
hexley	0:281d6ff68967	735	protocol header; if dest == IP_HDRINCL, p already includes an IP
hexley	0:281d6ff68967	736	header and p->payload points to that IP header)
hexley	0:281d6ff68967	737	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
hexley	0:281d6ff68967	738	* IP address of the netif used to send is used as source address)
hexley	0:281d6ff68967	739	* @param dest the destination IP address to send the packet to
hexley	0:281d6ff68967	740	* @param ttl the TTL value to be set in the IP header
hexley	0:281d6ff68967	741	* @param tos the TOS value to be set in the IP header
hexley	0:281d6ff68967	742	* @param proto the PROTOCOL to be set in the IP header
hexley	0:281d6ff68967	743	*
hexley	0:281d6ff68967	744	* @return ERR_RTE if no route is found
hexley	0:281d6ff68967	745	* see ip_output_if() for more return values
hexley	0:281d6ff68967	746	*/
hexley	0:281d6ff68967	747	err_t
hexley	0:281d6ff68967	748	ip_output(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
hexley	0:281d6ff68967	749	u8_t ttl, u8_t tos, u8_t proto)
hexley	0:281d6ff68967	750	{
hexley	0:281d6ff68967	751	struct netif *netif;
hexley	0:281d6ff68967	752
hexley	0:281d6ff68967	753	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
hexley	0:281d6ff68967	754	gets altered as the packet is passed down the stack */
hexley	0:281d6ff68967	755	LWIP_ASSERT("p->ref == 1", p->ref == 1);
hexley	0:281d6ff68967	756
hexley	0:281d6ff68967	757	if ((netif = ip_route(dest)) == NULL) {
hexley	0:281d6ff68967	758	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
hexley	0:281d6ff68967	759	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
hexley	0:281d6ff68967	760	IP_STATS_INC(ip.rterr);
hexley	0:281d6ff68967	761	return ERR_RTE;
hexley	0:281d6ff68967	762	}
hexley	0:281d6ff68967	763
hexley	0:281d6ff68967	764	return ip_output_if(p, src, dest, ttl, tos, proto, netif);
hexley	0:281d6ff68967	765	}
hexley	0:281d6ff68967	766
hexley	0:281d6ff68967	767	#if LWIP_NETIF_HWADDRHINT
hexley	0:281d6ff68967	768	/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
hexley	0:281d6ff68967	769	* before calling ip_output_if.
hexley	0:281d6ff68967	770	*
hexley	0:281d6ff68967	771	* @param p the packet to send (p->payload points to the data, e.g. next
hexley	0:281d6ff68967	772	protocol header; if dest == IP_HDRINCL, p already includes an IP
hexley	0:281d6ff68967	773	header and p->payload points to that IP header)
hexley	0:281d6ff68967	774	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
hexley	0:281d6ff68967	775	* IP address of the netif used to send is used as source address)
hexley	0:281d6ff68967	776	* @param dest the destination IP address to send the packet to
hexley	0:281d6ff68967	777	* @param ttl the TTL value to be set in the IP header
hexley	0:281d6ff68967	778	* @param tos the TOS value to be set in the IP header
hexley	0:281d6ff68967	779	* @param proto the PROTOCOL to be set in the IP header
hexley	0:281d6ff68967	780	* @param addr_hint address hint pointer set to netif->addr_hint before
hexley	0:281d6ff68967	781	* calling ip_output_if()
hexley	0:281d6ff68967	782	*
hexley	0:281d6ff68967	783	* @return ERR_RTE if no route is found
hexley	0:281d6ff68967	784	* see ip_output_if() for more return values
hexley	0:281d6ff68967	785	*/
hexley	0:281d6ff68967	786	err_t
hexley	0:281d6ff68967	787	ip_output_hinted(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
hexley	0:281d6ff68967	788	u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
hexley	0:281d6ff68967	789	{
hexley	0:281d6ff68967	790	struct netif *netif;
hexley	0:281d6ff68967	791	err_t err;
hexley	0:281d6ff68967	792
hexley	0:281d6ff68967	793	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
hexley	0:281d6ff68967	794	gets altered as the packet is passed down the stack */
hexley	0:281d6ff68967	795	LWIP_ASSERT("p->ref == 1", p->ref == 1);
hexley	0:281d6ff68967	796
hexley	0:281d6ff68967	797	if ((netif = ip_route(dest)) == NULL) {
hexley	0:281d6ff68967	798	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
hexley	0:281d6ff68967	799	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
hexley	0:281d6ff68967	800	IP_STATS_INC(ip.rterr);
hexley	0:281d6ff68967	801	return ERR_RTE;
hexley	0:281d6ff68967	802	}
hexley	0:281d6ff68967	803
hexley	0:281d6ff68967	804	netif->addr_hint = addr_hint;
hexley	0:281d6ff68967	805	err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
hexley	0:281d6ff68967	806	netif->addr_hint = NULL;
hexley	0:281d6ff68967	807
hexley	0:281d6ff68967	808	return err;
hexley	0:281d6ff68967	809	}
hexley	0:281d6ff68967	810	#endif /* LWIP_NETIF_HWADDRHINT*/
hexley	0:281d6ff68967	811
hexley	0:281d6ff68967	812	#if IP_DEBUG
hexley	0:281d6ff68967	813	/* Print an IP header by using LWIP_DEBUGF
hexley	0:281d6ff68967	814	* @param p an IP packet, p->payload pointing to the IP header
hexley	0:281d6ff68967	815	*/
hexley	0:281d6ff68967	816	void
hexley	0:281d6ff68967	817	ip_debug_print(struct pbuf *p)
hexley	0:281d6ff68967	818	{
hexley	0:281d6ff68967	819	struct ip_hdr iphdr = (struct ip_hdr )p->payload;
hexley	0:281d6ff68967	820	u8_t *payload;
hexley	0:281d6ff68967	821
hexley	0:281d6ff68967	822	payload = (u8_t *)iphdr + IP_HLEN;
hexley	0:281d6ff68967	823
hexley	0:281d6ff68967	824	LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
hexley	0:281d6ff68967	825	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
hexley	0:281d6ff68967	826	LWIP_DEBUGF(IP_DEBUG, ("\|%2"S16_F" \|%2"S16_F" \| 0x%02"X16_F" \| %5"U16_F" \| (v, hl, tos, len)\n",
hexley	0:281d6ff68967	827	IPH_V(iphdr),
hexley	0:281d6ff68967	828	IPH_HL(iphdr),
hexley	0:281d6ff68967	829	IPH_TOS(iphdr),
hexley	0:281d6ff68967	830	ntohs(IPH_LEN(iphdr))));
hexley	0:281d6ff68967	831	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
hexley	0:281d6ff68967	832	LWIP_DEBUGF(IP_DEBUG, ("\| %5"U16_F" \|%"U16_F"%"U16_F"%"U16_F"\| %4"U16_F" \| (id, flags, offset)\n",
hexley	0:281d6ff68967	833	ntohs(IPH_ID(iphdr)),
hexley	0:281d6ff68967	834	ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
hexley	0:281d6ff68967	835	ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
hexley	0:281d6ff68967	836	ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
hexley	0:281d6ff68967	837	ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
hexley	0:281d6ff68967	838	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
hexley	0:281d6ff68967	839	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| 0x%04"X16_F" \| (ttl, proto, chksum)\n",
hexley	0:281d6ff68967	840	IPH_TTL(iphdr),
hexley	0:281d6ff68967	841	IPH_PROTO(iphdr),
hexley	0:281d6ff68967	842	ntohs(IPH_CHKSUM(iphdr))));
hexley	0:281d6ff68967	843	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
hexley	0:281d6ff68967	844	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (src)\n",
hexley	0:281d6ff68967	845	ip4_addr1_16(&iphdr->src),
hexley	0:281d6ff68967	846	ip4_addr2_16(&iphdr->src),
hexley	0:281d6ff68967	847	ip4_addr3_16(&iphdr->src),
hexley	0:281d6ff68967	848	ip4_addr4_16(&iphdr->src)));
hexley	0:281d6ff68967	849	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
hexley	0:281d6ff68967	850	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (dest)\n",
hexley	0:281d6ff68967	851	ip4_addr1_16(&iphdr->dest),
hexley	0:281d6ff68967	852	ip4_addr2_16(&iphdr->dest),
hexley	0:281d6ff68967	853	ip4_addr3_16(&iphdr->dest),
hexley	0:281d6ff68967	854	ip4_addr4_16(&iphdr->dest)));
hexley	0:281d6ff68967	855	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
hexley	0:281d6ff68967	856	}
hexley	0:281d6ff68967	857	#endif /* IP_DEBUG */

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Type:	Library
Created:	19 Nov 2010
Imports:	44
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

lwip/core/ipv4/ip.c@0:281d6ff68967, 2010-11-19 (annotated)

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