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lwip/core/ipv4/ip.c@0:d616ece2d859, 2010-09-18 (annotated)

Committer:: mbed714
Date:: Sat Sep 18 23:05:49 2010 +0000
Revision:: 0:d616ece2d859

Who changed what in which revision?

User	Revision	Line number	New contents of line
mbed714	0:d616ece2d859	1	/**
mbed714	0:d616ece2d859	2	* @file
mbed714	0:d616ece2d859	3	* This is the IPv4 layer implementation for incoming and outgoing IP traffic.
mbed714	0:d616ece2d859	4	*
mbed714	0:d616ece2d859	5	* @see ip_frag.c
mbed714	0:d616ece2d859	6	*
mbed714	0:d616ece2d859	7	*/
mbed714	0:d616ece2d859	8
mbed714	0:d616ece2d859	9	/*
mbed714	0:d616ece2d859	10	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
mbed714	0:d616ece2d859	11	* All rights reserved.
mbed714	0:d616ece2d859	12	*
mbed714	0:d616ece2d859	13	* Redistribution and use in source and binary forms, with or without modification,
mbed714	0:d616ece2d859	14	* are permitted provided that the following conditions are met:
mbed714	0:d616ece2d859	15	*
mbed714	0:d616ece2d859	16	* 1. Redistributions of source code must retain the above copyright notice,
mbed714	0:d616ece2d859	17	* this list of conditions and the following disclaimer.
mbed714	0:d616ece2d859	18	* 2. Redistributions in binary form must reproduce the above copyright notice,
mbed714	0:d616ece2d859	19	* this list of conditions and the following disclaimer in the documentation
mbed714	0:d616ece2d859	20	* and/or other materials provided with the distribution.
mbed714	0:d616ece2d859	21	* 3. The name of the author may not be used to endorse or promote products
mbed714	0:d616ece2d859	22	* derived from this software without specific prior written permission.
mbed714	0:d616ece2d859	23	*
mbed714	0:d616ece2d859	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
mbed714	0:d616ece2d859	25	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
mbed714	0:d616ece2d859	26	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
mbed714	0:d616ece2d859	27	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
mbed714	0:d616ece2d859	28	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
mbed714	0:d616ece2d859	29	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
mbed714	0:d616ece2d859	30	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
mbed714	0:d616ece2d859	31	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
mbed714	0:d616ece2d859	32	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
mbed714	0:d616ece2d859	33	* OF SUCH DAMAGE.
mbed714	0:d616ece2d859	34	*
mbed714	0:d616ece2d859	35	* This file is part of the lwIP TCP/IP stack.
mbed714	0:d616ece2d859	36	*
mbed714	0:d616ece2d859	37	* Author: Adam Dunkels <adam@sics.se>
mbed714	0:d616ece2d859	38	*
mbed714	0:d616ece2d859	39	*/
mbed714	0:d616ece2d859	40
mbed714	0:d616ece2d859	41	#include "lwip/opt.h"
mbed714	0:d616ece2d859	42	#include "lwip/ip.h"
mbed714	0:d616ece2d859	43	#include "lwip/def.h"
mbed714	0:d616ece2d859	44	#include "lwip/mem.h"
mbed714	0:d616ece2d859	45	#include "lwip/ip_frag.h"
mbed714	0:d616ece2d859	46	#include "lwip/inet_chksum.h"
mbed714	0:d616ece2d859	47	#include "lwip/netif.h"
mbed714	0:d616ece2d859	48	#include "lwip/icmp.h"
mbed714	0:d616ece2d859	49	#include "lwip/igmp.h"
mbed714	0:d616ece2d859	50	#include "lwip/raw.h"
mbed714	0:d616ece2d859	51	#include "lwip/udp.h"
mbed714	0:d616ece2d859	52	#include "lwip/tcp_impl.h"
mbed714	0:d616ece2d859	53	#include "lwip/snmp.h"
mbed714	0:d616ece2d859	54	#include "lwip/dhcp.h"
mbed714	0:d616ece2d859	55	#include "lwip/autoip.h"
mbed714	0:d616ece2d859	56	#include "lwip/stats.h"
mbed714	0:d616ece2d859	57	#include "arch/perf.h"
mbed714	0:d616ece2d859	58
mbed714	0:d616ece2d859	59	#include <string.h>
mbed714	0:d616ece2d859	60
mbed714	0:d616ece2d859	61	/** Set this to 0 in the rare case of wanting to call an extra function to
mbed714	0:d616ece2d859	62	* generate the IP checksum (in contrast to calculating it on-the-fly). */
mbed714	0:d616ece2d859	63	#ifndef LWIP_INLINE_IP_CHKSUM
mbed714	0:d616ece2d859	64	#define LWIP_INLINE_IP_CHKSUM 1
mbed714	0:d616ece2d859	65	#endif
mbed714	0:d616ece2d859	66	#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
mbed714	0:d616ece2d859	67	#define CHECKSUM_GEN_IP_INLINE 1
mbed714	0:d616ece2d859	68	#else
mbed714	0:d616ece2d859	69	#define CHECKSUM_GEN_IP_INLINE 0
mbed714	0:d616ece2d859	70	#endif
mbed714	0:d616ece2d859	71
mbed714	0:d616ece2d859	72	#if LWIP_DHCP \|\| defined(LWIP_IP_ACCEPT_UDP_PORT)
mbed714	0:d616ece2d859	73	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
mbed714	0:d616ece2d859	74
mbed714	0:d616ece2d859	75	/** Some defines for DHCP to let link-layer-addressed packets through while the
mbed714	0:d616ece2d859	76	* netif is down.
mbed714	0:d616ece2d859	77	* To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT
mbed714	0:d616ece2d859	78	* to return 1 if the port is accepted and 0 if the port is not accepted.
mbed714	0:d616ece2d859	79	*/
mbed714	0:d616ece2d859	80	#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
mbed714	0:d616ece2d859	81	/* accept DHCP client port and custom port */
mbed714	0:d616ece2d859	82	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(DHCP_CLIENT_PORT)) \
mbed714	0:d616ece2d859	83	\|\| (LWIP_IP_ACCEPT_UDP_PORT(port)))
mbed714	0:d616ece2d859	84	#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
mbed714	0:d616ece2d859	85	/* accept custom port only */
mbed714	0:d616ece2d859	86	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(dst_port))
mbed714	0:d616ece2d859	87	#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
mbed714	0:d616ece2d859	88	/* accept DHCP client port only */
mbed714	0:d616ece2d859	89	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(DHCP_CLIENT_PORT))
mbed714	0:d616ece2d859	90	#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
mbed714	0:d616ece2d859	91
mbed714	0:d616ece2d859	92	#else /* LWIP_DHCP */
mbed714	0:d616ece2d859	93	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
mbed714	0:d616ece2d859	94	#endif /* LWIP_DHCP */
mbed714	0:d616ece2d859	95
mbed714	0:d616ece2d859	96	/**
mbed714	0:d616ece2d859	97	* The interface that provided the packet for the current callback
mbed714	0:d616ece2d859	98	* invocation.
mbed714	0:d616ece2d859	99	*/
mbed714	0:d616ece2d859	100	struct netif *current_netif;
mbed714	0:d616ece2d859	101
mbed714	0:d616ece2d859	102	/**
mbed714	0:d616ece2d859	103	* Header of the input packet currently being processed.
mbed714	0:d616ece2d859	104	*/
mbed714	0:d616ece2d859	105	const struct ip_hdr *current_header;
mbed714	0:d616ece2d859	106	/** Source IP address of current_header */
mbed714	0:d616ece2d859	107	ip_addr_t current_iphdr_src;
mbed714	0:d616ece2d859	108	/** Destination IP address of current_header */
mbed714	0:d616ece2d859	109	ip_addr_t current_iphdr_dest;
mbed714	0:d616ece2d859	110
mbed714	0:d616ece2d859	111	/** The IP header ID of the next outgoing IP packet */
mbed714	0:d616ece2d859	112	static u16_t ip_id;
mbed714	0:d616ece2d859	113
mbed714	0:d616ece2d859	114	/**
mbed714	0:d616ece2d859	115	* Finds the appropriate network interface for a given IP address. It
mbed714	0:d616ece2d859	116	* searches the list of network interfaces linearly. A match is found
mbed714	0:d616ece2d859	117	* if the masked IP address of the network interface equals the masked
mbed714	0:d616ece2d859	118	* IP address given to the function.
mbed714	0:d616ece2d859	119	*
mbed714	0:d616ece2d859	120	* @param dest the destination IP address for which to find the route
mbed714	0:d616ece2d859	121	* @return the netif on which to send to reach dest
mbed714	0:d616ece2d859	122	*/
mbed714	0:d616ece2d859	123	struct netif *
mbed714	0:d616ece2d859	124	ip_route(ip_addr_t *dest)
mbed714	0:d616ece2d859	125	{
mbed714	0:d616ece2d859	126	struct netif *netif;
mbed714	0:d616ece2d859	127
mbed714	0:d616ece2d859	128	/* iterate through netifs */
mbed714	0:d616ece2d859	129	for(netif = netif_list; netif != NULL; netif = netif->next) {
mbed714	0:d616ece2d859	130	/* network mask matches? */
mbed714	0:d616ece2d859	131	if (netif_is_up(netif)) {
mbed714	0:d616ece2d859	132	if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
mbed714	0:d616ece2d859	133	/* return netif on which to forward IP packet */
mbed714	0:d616ece2d859	134	return netif;
mbed714	0:d616ece2d859	135	}
mbed714	0:d616ece2d859	136	}
mbed714	0:d616ece2d859	137	}
mbed714	0:d616ece2d859	138	if ((netif_default == NULL) \|\| (!netif_is_up(netif_default))) {
mbed714	0:d616ece2d859	139	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
mbed714	0:d616ece2d859	140	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
mbed714	0:d616ece2d859	141	IP_STATS_INC(ip.rterr);
mbed714	0:d616ece2d859	142	snmp_inc_ipoutnoroutes();
mbed714	0:d616ece2d859	143	return NULL;
mbed714	0:d616ece2d859	144	}
mbed714	0:d616ece2d859	145	/* no matching netif found, use default netif */
mbed714	0:d616ece2d859	146	return netif_default;
mbed714	0:d616ece2d859	147	}
mbed714	0:d616ece2d859	148
mbed714	0:d616ece2d859	149	#if IP_FORWARD
mbed714	0:d616ece2d859	150	/**
mbed714	0:d616ece2d859	151	* Forwards an IP packet. It finds an appropriate route for the
mbed714	0:d616ece2d859	152	* packet, decrements the TTL value of the packet, adjusts the
mbed714	0:d616ece2d859	153	* checksum and outputs the packet on the appropriate interface.
mbed714	0:d616ece2d859	154	*
mbed714	0:d616ece2d859	155	* @param p the packet to forward (p->payload points to IP header)
mbed714	0:d616ece2d859	156	* @param iphdr the IP header of the input packet
mbed714	0:d616ece2d859	157	* @param inp the netif on which this packet was received
mbed714	0:d616ece2d859	158	*/
mbed714	0:d616ece2d859	159	static void
mbed714	0:d616ece2d859	160	ip_forward(struct pbuf p, struct ip_hdr iphdr, struct netif *inp)
mbed714	0:d616ece2d859	161	{
mbed714	0:d616ece2d859	162	struct netif *netif;
mbed714	0:d616ece2d859	163
mbed714	0:d616ece2d859	164	PERF_START;
mbed714	0:d616ece2d859	165
mbed714	0:d616ece2d859	166	/* RFC3927 2.7: do not forward link-local addresses */
mbed714	0:d616ece2d859	167	if (ip_addr_islinklocal(&current_iphdr_dest)) {
mbed714	0:d616ece2d859	168	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
mbed714	0:d616ece2d859	169	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
mbed714	0:d616ece2d859	170	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
mbed714	0:d616ece2d859	171	goto return_noroute;
mbed714	0:d616ece2d859	172	}
mbed714	0:d616ece2d859	173
mbed714	0:d616ece2d859	174	/* Find network interface where to forward this IP packet to. */
mbed714	0:d616ece2d859	175	netif = ip_route(&current_iphdr_dest);
mbed714	0:d616ece2d859	176	if (netif == NULL) {
mbed714	0:d616ece2d859	177	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
mbed714	0:d616ece2d859	178	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
mbed714	0:d616ece2d859	179	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
mbed714	0:d616ece2d859	180	goto return_noroute;
mbed714	0:d616ece2d859	181	}
mbed714	0:d616ece2d859	182	/* Do not forward packets onto the same network interface on which
mbed714	0:d616ece2d859	183	* they arrived. */
mbed714	0:d616ece2d859	184	if (netif == inp) {
mbed714	0:d616ece2d859	185	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
mbed714	0:d616ece2d859	186	goto return_noroute;
mbed714	0:d616ece2d859	187	}
mbed714	0:d616ece2d859	188
mbed714	0:d616ece2d859	189	/* decrement TTL */
mbed714	0:d616ece2d859	190	IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
mbed714	0:d616ece2d859	191	/* send ICMP if TTL == 0 */
mbed714	0:d616ece2d859	192	if (IPH_TTL(iphdr) == 0) {
mbed714	0:d616ece2d859	193	snmp_inc_ipinhdrerrors();
mbed714	0:d616ece2d859	194	#if LWIP_ICMP
mbed714	0:d616ece2d859	195	/* Don't send ICMP messages in response to ICMP messages */
mbed714	0:d616ece2d859	196	if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
mbed714	0:d616ece2d859	197	icmp_time_exceeded(p, ICMP_TE_TTL);
mbed714	0:d616ece2d859	198	}
mbed714	0:d616ece2d859	199	#endif /* LWIP_ICMP */
mbed714	0:d616ece2d859	200	return;
mbed714	0:d616ece2d859	201	}
mbed714	0:d616ece2d859	202
mbed714	0:d616ece2d859	203	/* Incrementally update the IP checksum. */
mbed714	0:d616ece2d859	204	if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffff - 0x100)) {
mbed714	0:d616ece2d859	205	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
mbed714	0:d616ece2d859	206	} else {
mbed714	0:d616ece2d859	207	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
mbed714	0:d616ece2d859	208	}
mbed714	0:d616ece2d859	209
mbed714	0:d616ece2d859	210	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
mbed714	0:d616ece2d859	211	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
mbed714	0:d616ece2d859	212	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
mbed714	0:d616ece2d859	213
mbed714	0:d616ece2d859	214	IP_STATS_INC(ip.fw);
mbed714	0:d616ece2d859	215	IP_STATS_INC(ip.xmit);
mbed714	0:d616ece2d859	216	snmp_inc_ipforwdatagrams();
mbed714	0:d616ece2d859	217
mbed714	0:d616ece2d859	218	PERF_STOP("ip_forward");
mbed714	0:d616ece2d859	219	/* transmit pbuf on chosen interface */
mbed714	0:d616ece2d859	220	netif->output(netif, p, &current_iphdr_dest);
mbed714	0:d616ece2d859	221	return;
mbed714	0:d616ece2d859	222	return_noroute:
mbed714	0:d616ece2d859	223	snmp_inc_ipoutnoroutes();
mbed714	0:d616ece2d859	224	}
mbed714	0:d616ece2d859	225	#endif /* IP_FORWARD */
mbed714	0:d616ece2d859	226
mbed714	0:d616ece2d859	227	/**
mbed714	0:d616ece2d859	228	* This function is called by the network interface device driver when
mbed714	0:d616ece2d859	229	* an IP packet is received. The function does the basic checks of the
mbed714	0:d616ece2d859	230	* IP header such as packet size being at least larger than the header
mbed714	0:d616ece2d859	231	* size etc. If the packet was not destined for us, the packet is
mbed714	0:d616ece2d859	232	* forwarded (using ip_forward). The IP checksum is always checked.
mbed714	0:d616ece2d859	233	*
mbed714	0:d616ece2d859	234	* Finally, the packet is sent to the upper layer protocol input function.
mbed714	0:d616ece2d859	235	*
mbed714	0:d616ece2d859	236	* @param p the received IP packet (p->payload points to IP header)
mbed714	0:d616ece2d859	237	* @param inp the netif on which this packet was received
mbed714	0:d616ece2d859	238	* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
mbed714	0:d616ece2d859	239	* processed, but currently always returns ERR_OK)
mbed714	0:d616ece2d859	240	*/
mbed714	0:d616ece2d859	241	err_t
mbed714	0:d616ece2d859	242	ip_input(struct pbuf p, struct netif inp)
mbed714	0:d616ece2d859	243	{
mbed714	0:d616ece2d859	244	struct ip_hdr *iphdr;
mbed714	0:d616ece2d859	245	struct netif *netif;
mbed714	0:d616ece2d859	246	u16_t iphdr_hlen;
mbed714	0:d616ece2d859	247	u16_t iphdr_len;
mbed714	0:d616ece2d859	248	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
mbed714	0:d616ece2d859	249	int check_ip_src=1;
mbed714	0:d616ece2d859	250	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
mbed714	0:d616ece2d859	251
mbed714	0:d616ece2d859	252	IP_STATS_INC(ip.recv);
mbed714	0:d616ece2d859	253	snmp_inc_ipinreceives();
mbed714	0:d616ece2d859	254
mbed714	0:d616ece2d859	255	/* identify the IP header */
mbed714	0:d616ece2d859	256	iphdr = (struct ip_hdr *)p->payload;
mbed714	0:d616ece2d859	257	if (IPH_V(iphdr) != 4) {
mbed714	0:d616ece2d859	258	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
mbed714	0:d616ece2d859	259	ip_debug_print(p);
mbed714	0:d616ece2d859	260	pbuf_free(p);
mbed714	0:d616ece2d859	261	IP_STATS_INC(ip.err);
mbed714	0:d616ece2d859	262	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	263	snmp_inc_ipinhdrerrors();
mbed714	0:d616ece2d859	264	return ERR_OK;
mbed714	0:d616ece2d859	265	}
mbed714	0:d616ece2d859	266
mbed714	0:d616ece2d859	267	/* obtain IP header length in number of 32-bit words */
mbed714	0:d616ece2d859	268	iphdr_hlen = IPH_HL(iphdr);
mbed714	0:d616ece2d859	269	/* calculate IP header length in bytes */
mbed714	0:d616ece2d859	270	iphdr_hlen *= 4;
mbed714	0:d616ece2d859	271	/* obtain ip length in bytes */
mbed714	0:d616ece2d859	272	iphdr_len = ntohs(IPH_LEN(iphdr));
mbed714	0:d616ece2d859	273
mbed714	0:d616ece2d859	274	/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
mbed714	0:d616ece2d859	275	if ((iphdr_hlen > p->len) \|\| (iphdr_len > p->tot_len)) {
mbed714	0:d616ece2d859	276	if (iphdr_hlen > p->len) {
mbed714	0:d616ece2d859	277	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
mbed714	0:d616ece2d859	278	("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
mbed714	0:d616ece2d859	279	iphdr_hlen, p->len));
mbed714	0:d616ece2d859	280	}
mbed714	0:d616ece2d859	281	if (iphdr_len > p->tot_len) {
mbed714	0:d616ece2d859	282	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
mbed714	0:d616ece2d859	283	("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
mbed714	0:d616ece2d859	284	iphdr_len, p->tot_len));
mbed714	0:d616ece2d859	285	}
mbed714	0:d616ece2d859	286	/* free (drop) packet pbufs */
mbed714	0:d616ece2d859	287	pbuf_free(p);
mbed714	0:d616ece2d859	288	IP_STATS_INC(ip.lenerr);
mbed714	0:d616ece2d859	289	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	290	snmp_inc_ipindiscards();
mbed714	0:d616ece2d859	291	return ERR_OK;
mbed714	0:d616ece2d859	292	}
mbed714	0:d616ece2d859	293
mbed714	0:d616ece2d859	294	/* verify checksum */
mbed714	0:d616ece2d859	295	#if CHECKSUM_CHECK_IP
mbed714	0:d616ece2d859	296	if (inet_chksum(iphdr, iphdr_hlen) != 0) {
mbed714	0:d616ece2d859	297
mbed714	0:d616ece2d859	298	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
mbed714	0:d616ece2d859	299	("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
mbed714	0:d616ece2d859	300	ip_debug_print(p);
mbed714	0:d616ece2d859	301	pbuf_free(p);
mbed714	0:d616ece2d859	302	IP_STATS_INC(ip.chkerr);
mbed714	0:d616ece2d859	303	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	304	snmp_inc_ipinhdrerrors();
mbed714	0:d616ece2d859	305	return ERR_OK;
mbed714	0:d616ece2d859	306	}
mbed714	0:d616ece2d859	307	#endif
mbed714	0:d616ece2d859	308
mbed714	0:d616ece2d859	309	/* Trim pbuf. This should have been done at the netif layer,
mbed714	0:d616ece2d859	310	* but we'll do it anyway just to be sure that its done. */
mbed714	0:d616ece2d859	311	pbuf_realloc(p, iphdr_len);
mbed714	0:d616ece2d859	312
mbed714	0:d616ece2d859	313	/* copy IP addresses to aligned ip_addr_t */
mbed714	0:d616ece2d859	314	ip_addr_copy(current_iphdr_dest, iphdr->dest);
mbed714	0:d616ece2d859	315	ip_addr_copy(current_iphdr_src, iphdr->src);
mbed714	0:d616ece2d859	316
mbed714	0:d616ece2d859	317	/* match packet against an interface, i.e. is this packet for us? */
mbed714	0:d616ece2d859	318	#if LWIP_IGMP
mbed714	0:d616ece2d859	319	if (ip_addr_ismulticast(&current_iphdr_dest)) {
mbed714	0:d616ece2d859	320	if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &current_iphdr_dest))) {
mbed714	0:d616ece2d859	321	netif = inp;
mbed714	0:d616ece2d859	322	} else {
mbed714	0:d616ece2d859	323	netif = NULL;
mbed714	0:d616ece2d859	324	}
mbed714	0:d616ece2d859	325	} else
mbed714	0:d616ece2d859	326	#endif /* LWIP_IGMP */
mbed714	0:d616ece2d859	327	{
mbed714	0:d616ece2d859	328	/* start trying with inp. if that's not acceptable, start walking the
mbed714	0:d616ece2d859	329	list of configured netifs.
mbed714	0:d616ece2d859	330	'first' is used as a boolean to mark whether we started walking the list */
mbed714	0:d616ece2d859	331	int first = 1;
mbed714	0:d616ece2d859	332	netif = inp;
mbed714	0:d616ece2d859	333	do {
mbed714	0:d616ece2d859	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",
mbed714	0:d616ece2d859	335	ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
mbed714	0:d616ece2d859	336	ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
mbed714	0:d616ece2d859	337	ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
mbed714	0:d616ece2d859	338	ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
mbed714	0:d616ece2d859	339
mbed714	0:d616ece2d859	340	/* interface is up and configured? */
mbed714	0:d616ece2d859	341	if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
mbed714	0:d616ece2d859	342	/* unicast to this interface address? */
mbed714	0:d616ece2d859	343	if (ip_addr_cmp(&current_iphdr_dest, &(netif->ip_addr)) \|\|
mbed714	0:d616ece2d859	344	/* or broadcast on this interface network address? */
mbed714	0:d616ece2d859	345	ip_addr_isbroadcast(&current_iphdr_dest, netif)) {
mbed714	0:d616ece2d859	346	LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
mbed714	0:d616ece2d859	347	netif->name[0], netif->name[1]));
mbed714	0:d616ece2d859	348	/* break out of for loop */
mbed714	0:d616ece2d859	349	break;
mbed714	0:d616ece2d859	350	}
mbed714	0:d616ece2d859	351	#if LWIP_AUTOIP
mbed714	0:d616ece2d859	352	/* connections to link-local addresses must persist after changing
mbed714	0:d616ece2d859	353	the netif's address (RFC3927 ch. 1.9) */
mbed714	0:d616ece2d859	354	if ((netif->autoip != NULL) &&
mbed714	0:d616ece2d859	355	ip_addr_cmp(&current_iphdr_dest, &(netif->autoip->llipaddr))) {
mbed714	0:d616ece2d859	356	LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
mbed714	0:d616ece2d859	357	netif->name[0], netif->name[1]));
mbed714	0:d616ece2d859	358	/* break out of for loop */
mbed714	0:d616ece2d859	359	break;
mbed714	0:d616ece2d859	360	}
mbed714	0:d616ece2d859	361	#endif /* LWIP_AUTOIP */
mbed714	0:d616ece2d859	362	}
mbed714	0:d616ece2d859	363	if (first) {
mbed714	0:d616ece2d859	364	first = 0;
mbed714	0:d616ece2d859	365	netif = netif_list;
mbed714	0:d616ece2d859	366	} else {
mbed714	0:d616ece2d859	367	netif = netif->next;
mbed714	0:d616ece2d859	368	}
mbed714	0:d616ece2d859	369	if (netif == inp) {
mbed714	0:d616ece2d859	370	netif = netif->next;
mbed714	0:d616ece2d859	371	}
mbed714	0:d616ece2d859	372	} while(netif != NULL);
mbed714	0:d616ece2d859	373	}
mbed714	0:d616ece2d859	374
mbed714	0:d616ece2d859	375	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
mbed714	0:d616ece2d859	376	/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
mbed714	0:d616ece2d859	377	* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
mbed714	0:d616ece2d859	378	* According to RFC 1542 section 3.1.1, referred by RFC 2131).
mbed714	0:d616ece2d859	379	*
mbed714	0:d616ece2d859	380	* If you want to accept private broadcast communication while a netif is down,
mbed714	0:d616ece2d859	381	* define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
mbed714	0:d616ece2d859	382	*
mbed714	0:d616ece2d859	383	* #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
mbed714	0:d616ece2d859	384	*/
mbed714	0:d616ece2d859	385	if (netif == NULL) {
mbed714	0:d616ece2d859	386	/* remote port is DHCP server? */
mbed714	0:d616ece2d859	387	if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
mbed714	0:d616ece2d859	388	struct udp_hdr udphdr = (struct udp_hdr )((u8_t *)iphdr + iphdr_hlen);
mbed714	0:d616ece2d859	389	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
mbed714	0:d616ece2d859	390	ntohs(udphdr->dest)));
mbed714	0:d616ece2d859	391	if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
mbed714	0:d616ece2d859	392	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
mbed714	0:d616ece2d859	393	netif = inp;
mbed714	0:d616ece2d859	394	check_ip_src = 0;
mbed714	0:d616ece2d859	395	}
mbed714	0:d616ece2d859	396	}
mbed714	0:d616ece2d859	397	}
mbed714	0:d616ece2d859	398	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
mbed714	0:d616ece2d859	399
mbed714	0:d616ece2d859	400	/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
mbed714	0:d616ece2d859	401	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
mbed714	0:d616ece2d859	402	/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
mbed714	0:d616ece2d859	403	if (check_ip_src && !ip_addr_isany(&current_iphdr_src))
mbed714	0:d616ece2d859	404	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
mbed714	0:d616ece2d859	405	{ if ((ip_addr_isbroadcast(&current_iphdr_src, inp)) \|\|
mbed714	0:d616ece2d859	406	(ip_addr_ismulticast(&current_iphdr_src))) {
mbed714	0:d616ece2d859	407	/* packet source is not valid */
mbed714	0:d616ece2d859	408	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
mbed714	0:d616ece2d859	409	/* free (drop) packet pbufs */
mbed714	0:d616ece2d859	410	pbuf_free(p);
mbed714	0:d616ece2d859	411	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	412	snmp_inc_ipinaddrerrors();
mbed714	0:d616ece2d859	413	snmp_inc_ipindiscards();
mbed714	0:d616ece2d859	414	return ERR_OK;
mbed714	0:d616ece2d859	415	}
mbed714	0:d616ece2d859	416	}
mbed714	0:d616ece2d859	417
mbed714	0:d616ece2d859	418	/* packet not for us? */
mbed714	0:d616ece2d859	419	if (netif == NULL) {
mbed714	0:d616ece2d859	420	/* packet not for us, route or discard */
mbed714	0:d616ece2d859	421	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
mbed714	0:d616ece2d859	422	#if IP_FORWARD
mbed714	0:d616ece2d859	423	/* non-broadcast packet? */
mbed714	0:d616ece2d859	424	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp)) {
mbed714	0:d616ece2d859	425	/* try to forward IP packet on (other) interfaces */
mbed714	0:d616ece2d859	426	ip_forward(p, iphdr, inp);
mbed714	0:d616ece2d859	427	} else
mbed714	0:d616ece2d859	428	#endif /* IP_FORWARD */
mbed714	0:d616ece2d859	429	{
mbed714	0:d616ece2d859	430	snmp_inc_ipinaddrerrors();
mbed714	0:d616ece2d859	431	snmp_inc_ipindiscards();
mbed714	0:d616ece2d859	432	}
mbed714	0:d616ece2d859	433	pbuf_free(p);
mbed714	0:d616ece2d859	434	return ERR_OK;
mbed714	0:d616ece2d859	435	}
mbed714	0:d616ece2d859	436	/* packet consists of multiple fragments? */
mbed714	0:d616ece2d859	437	if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK \| IP_MF)) != 0) {
mbed714	0:d616ece2d859	438	#if IP_REASSEMBLY /* packet fragment reassembly code present? */
mbed714	0:d616ece2d859	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",
mbed714	0:d616ece2d859	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));
mbed714	0:d616ece2d859	441	/* reassemble the packet*/
mbed714	0:d616ece2d859	442	p = ip_reass(p);
mbed714	0:d616ece2d859	443	/* packet not fully reassembled yet? */
mbed714	0:d616ece2d859	444	if (p == NULL) {
mbed714	0:d616ece2d859	445	return ERR_OK;
mbed714	0:d616ece2d859	446	}
mbed714	0:d616ece2d859	447	iphdr = (struct ip_hdr *)p->payload;
mbed714	0:d616ece2d859	448	#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
mbed714	0:d616ece2d859	449	pbuf_free(p);
mbed714	0:d616ece2d859	450	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
mbed714	0:d616ece2d859	451	ntohs(IPH_OFFSET(iphdr))));
mbed714	0:d616ece2d859	452	IP_STATS_INC(ip.opterr);
mbed714	0:d616ece2d859	453	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	454	/* unsupported protocol feature */
mbed714	0:d616ece2d859	455	snmp_inc_ipinunknownprotos();
mbed714	0:d616ece2d859	456	return ERR_OK;
mbed714	0:d616ece2d859	457	#endif /* IP_REASSEMBLY */
mbed714	0:d616ece2d859	458	}
mbed714	0:d616ece2d859	459
mbed714	0:d616ece2d859	460	#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
mbed714	0:d616ece2d859	461
mbed714	0:d616ece2d859	462	#if LWIP_IGMP
mbed714	0:d616ece2d859	463	/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
mbed714	0:d616ece2d859	464	if((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
mbed714	0:d616ece2d859	465	#else
mbed714	0:d616ece2d859	466	if (iphdr_hlen > IP_HLEN) {
mbed714	0:d616ece2d859	467	#endif /* LWIP_IGMP */
mbed714	0:d616ece2d859	468	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
mbed714	0:d616ece2d859	469	pbuf_free(p);
mbed714	0:d616ece2d859	470	IP_STATS_INC(ip.opterr);
mbed714	0:d616ece2d859	471	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	472	/* unsupported protocol feature */
mbed714	0:d616ece2d859	473	snmp_inc_ipinunknownprotos();
mbed714	0:d616ece2d859	474	return ERR_OK;
mbed714	0:d616ece2d859	475	}
mbed714	0:d616ece2d859	476	#endif /* IP_OPTIONS_ALLOWED == 0 */
mbed714	0:d616ece2d859	477
mbed714	0:d616ece2d859	478	/* send to upper layers */
mbed714	0:d616ece2d859	479	LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
mbed714	0:d616ece2d859	480	ip_debug_print(p);
mbed714	0:d616ece2d859	481	LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
mbed714	0:d616ece2d859	482
mbed714	0:d616ece2d859	483	current_netif = inp;
mbed714	0:d616ece2d859	484	current_header = iphdr;
mbed714	0:d616ece2d859	485
mbed714	0:d616ece2d859	486	#if LWIP_RAW
mbed714	0:d616ece2d859	487	/* raw input did not eat the packet? */
mbed714	0:d616ece2d859	488	if (raw_input(p, inp) == 0)
mbed714	0:d616ece2d859	489	#endif /* LWIP_RAW */
mbed714	0:d616ece2d859	490	{
mbed714	0:d616ece2d859	491
mbed714	0:d616ece2d859	492	switch (IPH_PROTO(iphdr)) {
mbed714	0:d616ece2d859	493	#if LWIP_UDP
mbed714	0:d616ece2d859	494	case IP_PROTO_UDP:
mbed714	0:d616ece2d859	495	#if LWIP_UDPLITE
mbed714	0:d616ece2d859	496	case IP_PROTO_UDPLITE:
mbed714	0:d616ece2d859	497	#endif /* LWIP_UDPLITE */
mbed714	0:d616ece2d859	498	snmp_inc_ipindelivers();
mbed714	0:d616ece2d859	499	udp_input(p, inp);
mbed714	0:d616ece2d859	500	break;
mbed714	0:d616ece2d859	501	#endif /* LWIP_UDP */
mbed714	0:d616ece2d859	502	#if LWIP_TCP
mbed714	0:d616ece2d859	503	case IP_PROTO_TCP:
mbed714	0:d616ece2d859	504	snmp_inc_ipindelivers();
mbed714	0:d616ece2d859	505	tcp_input(p, inp);
mbed714	0:d616ece2d859	506	break;
mbed714	0:d616ece2d859	507	#endif /* LWIP_TCP */
mbed714	0:d616ece2d859	508	#if LWIP_ICMP
mbed714	0:d616ece2d859	509	case IP_PROTO_ICMP:
mbed714	0:d616ece2d859	510	snmp_inc_ipindelivers();
mbed714	0:d616ece2d859	511	icmp_input(p, inp);
mbed714	0:d616ece2d859	512	break;
mbed714	0:d616ece2d859	513	#endif /* LWIP_ICMP */
mbed714	0:d616ece2d859	514	#if LWIP_IGMP
mbed714	0:d616ece2d859	515	case IP_PROTO_IGMP:
mbed714	0:d616ece2d859	516	igmp_input(p, inp, &current_iphdr_dest);
mbed714	0:d616ece2d859	517	break;
mbed714	0:d616ece2d859	518	#endif /* LWIP_IGMP */
mbed714	0:d616ece2d859	519	default:
mbed714	0:d616ece2d859	520	#if LWIP_ICMP
mbed714	0:d616ece2d859	521	/* send ICMP destination protocol unreachable unless is was a broadcast */
mbed714	0:d616ece2d859	522	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp) &&
mbed714	0:d616ece2d859	523	!ip_addr_ismulticast(&current_iphdr_dest)) {
mbed714	0:d616ece2d859	524	p->payload = iphdr;
mbed714	0:d616ece2d859	525	icmp_dest_unreach(p, ICMP_DUR_PROTO);
mbed714	0:d616ece2d859	526	}
mbed714	0:d616ece2d859	527	#endif /* LWIP_ICMP */
mbed714	0:d616ece2d859	528	pbuf_free(p);
mbed714	0:d616ece2d859	529
mbed714	0:d616ece2d859	530	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
mbed714	0:d616ece2d859	531
mbed714	0:d616ece2d859	532	IP_STATS_INC(ip.proterr);
mbed714	0:d616ece2d859	533	IP_STATS_INC(ip.drop);
mbed714	0:d616ece2d859	534	snmp_inc_ipinunknownprotos();
mbed714	0:d616ece2d859	535	}
mbed714	0:d616ece2d859	536	}
mbed714	0:d616ece2d859	537
mbed714	0:d616ece2d859	538	current_netif = NULL;
mbed714	0:d616ece2d859	539	current_header = NULL;
mbed714	0:d616ece2d859	540	ip_addr_set_any(&current_iphdr_src);
mbed714	0:d616ece2d859	541	ip_addr_set_any(&current_iphdr_dest);
mbed714	0:d616ece2d859	542
mbed714	0:d616ece2d859	543	return ERR_OK;
mbed714	0:d616ece2d859	544	}
mbed714	0:d616ece2d859	545
mbed714	0:d616ece2d859	546	/**
mbed714	0:d616ece2d859	547	* Sends an IP packet on a network interface. This function constructs
mbed714	0:d616ece2d859	548	* the IP header and calculates the IP header checksum. If the source
mbed714	0:d616ece2d859	549	* IP address is NULL, the IP address of the outgoing network
mbed714	0:d616ece2d859	550	* interface is filled in as source address.
mbed714	0:d616ece2d859	551	* If the destination IP address is IP_HDRINCL, p is assumed to already
mbed714	0:d616ece2d859	552	* include an IP header and p->payload points to it instead of the data.
mbed714	0:d616ece2d859	553	*
mbed714	0:d616ece2d859	554	* @param p the packet to send (p->payload points to the data, e.g. next
mbed714	0:d616ece2d859	555	protocol header; if dest == IP_HDRINCL, p already includes an IP
mbed714	0:d616ece2d859	556	header and p->payload points to that IP header)
mbed714	0:d616ece2d859	557	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
mbed714	0:d616ece2d859	558	* IP address of the netif used to send is used as source address)
mbed714	0:d616ece2d859	559	* @param dest the destination IP address to send the packet to
mbed714	0:d616ece2d859	560	* @param ttl the TTL value to be set in the IP header
mbed714	0:d616ece2d859	561	* @param tos the TOS value to be set in the IP header
mbed714	0:d616ece2d859	562	* @param proto the PROTOCOL to be set in the IP header
mbed714	0:d616ece2d859	563	* @param netif the netif on which to send this packet
mbed714	0:d616ece2d859	564	* @return ERR_OK if the packet was sent OK
mbed714	0:d616ece2d859	565	* ERR_BUF if p doesn't have enough space for IP/LINK headers
mbed714	0:d616ece2d859	566	* returns errors returned by netif->output
mbed714	0:d616ece2d859	567	*
mbed714	0:d616ece2d859	568	* @note ip_id: RFC791 "some host may be able to simply use
mbed714	0:d616ece2d859	569	* unique identifiers independent of destination"
mbed714	0:d616ece2d859	570	*/
mbed714	0:d616ece2d859	571	err_t
mbed714	0:d616ece2d859	572	ip_output_if(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
mbed714	0:d616ece2d859	573	u8_t ttl, u8_t tos,
mbed714	0:d616ece2d859	574	u8_t proto, struct netif *netif)
mbed714	0:d616ece2d859	575	{
mbed714	0:d616ece2d859	576	#if IP_OPTIONS_SEND
mbed714	0:d616ece2d859	577	return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
mbed714	0:d616ece2d859	578	}
mbed714	0:d616ece2d859	579
mbed714	0:d616ece2d859	580	/**
mbed714	0:d616ece2d859	581	* Same as ip_output_if() but with the possibility to include IP options:
mbed714	0:d616ece2d859	582	*
mbed714	0:d616ece2d859	583	* @ param ip_options pointer to the IP options, copied into the IP header
mbed714	0:d616ece2d859	584	* @ param optlen length of ip_options
mbed714	0:d616ece2d859	585	*/
mbed714	0:d616ece2d859	586	err_t ip_output_if_opt(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
mbed714	0:d616ece2d859	587	u8_t ttl, u8_t tos, u8_t proto, struct netif netif, void ip_options,
mbed714	0:d616ece2d859	588	u16_t optlen)
mbed714	0:d616ece2d859	589	{
mbed714	0:d616ece2d859	590	#endif /* IP_OPTIONS_SEND */
mbed714	0:d616ece2d859	591	struct ip_hdr *iphdr;
mbed714	0:d616ece2d859	592	ip_addr_t dest_addr;
mbed714	0:d616ece2d859	593	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	594	u32_t chk_sum = 0;
mbed714	0:d616ece2d859	595	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	596
mbed714	0:d616ece2d859	597	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
mbed714	0:d616ece2d859	598	gets altered as the packet is passed down the stack */
mbed714	0:d616ece2d859	599	LWIP_ASSERT("p->ref == 1", p->ref == 1);
mbed714	0:d616ece2d859	600
mbed714	0:d616ece2d859	601	snmp_inc_ipoutrequests();
mbed714	0:d616ece2d859	602
mbed714	0:d616ece2d859	603	/* Should the IP header be generated or is it already included in p? */
mbed714	0:d616ece2d859	604	if (dest != IP_HDRINCL) {
mbed714	0:d616ece2d859	605	u16_t ip_hlen = IP_HLEN;
mbed714	0:d616ece2d859	606	#if IP_OPTIONS_SEND
mbed714	0:d616ece2d859	607	u16_t optlen_aligned = 0;
mbed714	0:d616ece2d859	608	if (optlen != 0) {
mbed714	0:d616ece2d859	609	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	610	int i;
mbed714	0:d616ece2d859	611	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	612	/* round up to a multiple of 4 */
mbed714	0:d616ece2d859	613	optlen_aligned = ((optlen + 3) & ~3);
mbed714	0:d616ece2d859	614	ip_hlen += optlen_aligned;
mbed714	0:d616ece2d859	615	/* First write in the IP options */
mbed714	0:d616ece2d859	616	if (pbuf_header(p, optlen_aligned)) {
mbed714	0:d616ece2d859	617	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
mbed714	0:d616ece2d859	618	IP_STATS_INC(ip.err);
mbed714	0:d616ece2d859	619	snmp_inc_ipoutdiscards();
mbed714	0:d616ece2d859	620	return ERR_BUF;
mbed714	0:d616ece2d859	621	}
mbed714	0:d616ece2d859	622	MEMCPY(p->payload, ip_options, optlen);
mbed714	0:d616ece2d859	623	if (optlen < optlen_aligned) {
mbed714	0:d616ece2d859	624	/* zero the remaining bytes */
mbed714	0:d616ece2d859	625	memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
mbed714	0:d616ece2d859	626	}
mbed714	0:d616ece2d859	627	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	628	for (i = 0; i < optlen_aligned; i += sizeof(u16_t)) {
mbed714	0:d616ece2d859	629	chk_sum += ((u16_t*)p->payload)[i];
mbed714	0:d616ece2d859	630	}
mbed714	0:d616ece2d859	631	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	632	}
mbed714	0:d616ece2d859	633	#endif /* IP_OPTIONS_SEND */
mbed714	0:d616ece2d859	634	/* generate IP header */
mbed714	0:d616ece2d859	635	if (pbuf_header(p, IP_HLEN)) {
mbed714	0:d616ece2d859	636	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
mbed714	0:d616ece2d859	637
mbed714	0:d616ece2d859	638	IP_STATS_INC(ip.err);
mbed714	0:d616ece2d859	639	snmp_inc_ipoutdiscards();
mbed714	0:d616ece2d859	640	return ERR_BUF;
mbed714	0:d616ece2d859	641	}
mbed714	0:d616ece2d859	642
mbed714	0:d616ece2d859	643	iphdr = (struct ip_hdr *)p->payload;
mbed714	0:d616ece2d859	644	LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
mbed714	0:d616ece2d859	645	(p->len >= sizeof(struct ip_hdr)));
mbed714	0:d616ece2d859	646
mbed714	0:d616ece2d859	647	IPH_TTL_SET(iphdr, ttl);
mbed714	0:d616ece2d859	648	IPH_PROTO_SET(iphdr, proto);
mbed714	0:d616ece2d859	649	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	650	chk_sum += LWIP_MAKE_U16(proto, ttl);
mbed714	0:d616ece2d859	651	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	652
mbed714	0:d616ece2d859	653	/* dest cannot be NULL here */
mbed714	0:d616ece2d859	654	ip_addr_copy(iphdr->dest, *dest);
mbed714	0:d616ece2d859	655	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	656	chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
mbed714	0:d616ece2d859	657	chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
mbed714	0:d616ece2d859	658	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	659
mbed714	0:d616ece2d859	660	IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
mbed714	0:d616ece2d859	661	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	662	chk_sum += iphdr->_v_hl_tos;
mbed714	0:d616ece2d859	663	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	664	IPH_LEN_SET(iphdr, htons(p->tot_len));
mbed714	0:d616ece2d859	665	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	666	chk_sum += iphdr->_len;
mbed714	0:d616ece2d859	667	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	668	IPH_OFFSET_SET(iphdr, 0);
mbed714	0:d616ece2d859	669	IPH_ID_SET(iphdr, htons(ip_id));
mbed714	0:d616ece2d859	670	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	671	chk_sum += iphdr->_id;
mbed714	0:d616ece2d859	672	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	673	++ip_id;
mbed714	0:d616ece2d859	674
mbed714	0:d616ece2d859	675	if (ip_addr_isany(src)) {
mbed714	0:d616ece2d859	676	ip_addr_copy(iphdr->src, netif->ip_addr);
mbed714	0:d616ece2d859	677	} else {
mbed714	0:d616ece2d859	678	/* src cannot be NULL here */
mbed714	0:d616ece2d859	679	ip_addr_copy(iphdr->src, *src);
mbed714	0:d616ece2d859	680	}
mbed714	0:d616ece2d859	681
mbed714	0:d616ece2d859	682	#if CHECKSUM_GEN_IP_INLINE
mbed714	0:d616ece2d859	683	chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
mbed714	0:d616ece2d859	684	chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
mbed714	0:d616ece2d859	685	chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
mbed714	0:d616ece2d859	686	chk_sum = (chk_sum >> 16) + chk_sum;
mbed714	0:d616ece2d859	687	chk_sum = ~chk_sum;
mbed714	0:d616ece2d859	688	iphdr->_chksum = chk_sum; /* network order */
mbed714	0:d616ece2d859	689	#else /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	690	IPH_CHKSUM_SET(iphdr, 0);
mbed714	0:d616ece2d859	691	#if CHECKSUM_GEN_IP
mbed714	0:d616ece2d859	692	IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
mbed714	0:d616ece2d859	693	#endif
mbed714	0:d616ece2d859	694	#endif /* CHECKSUM_GEN_IP_INLINE */
mbed714	0:d616ece2d859	695	} else {
mbed714	0:d616ece2d859	696	/* IP header already included in p */
mbed714	0:d616ece2d859	697	iphdr = (struct ip_hdr *)p->payload;
mbed714	0:d616ece2d859	698	ip_addr_copy(dest_addr, iphdr->dest);
mbed714	0:d616ece2d859	699	dest = &dest_addr;
mbed714	0:d616ece2d859	700	}
mbed714	0:d616ece2d859	701
mbed714	0:d616ece2d859	702	IP_STATS_INC(ip.xmit);
mbed714	0:d616ece2d859	703
mbed714	0:d616ece2d859	704	LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
mbed714	0:d616ece2d859	705	ip_debug_print(p);
mbed714	0:d616ece2d859	706
mbed714	0:d616ece2d859	707	#if ENABLE_LOOPBACK
mbed714	0:d616ece2d859	708	if (ip_addr_cmp(dest, &netif->ip_addr)) {
mbed714	0:d616ece2d859	709	/* Packet to self, enqueue it for loopback */
mbed714	0:d616ece2d859	710	LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
mbed714	0:d616ece2d859	711	return netif_loop_output(netif, p, dest);
mbed714	0:d616ece2d859	712	}
mbed714	0:d616ece2d859	713	#if LWIP_IGMP
mbed714	0:d616ece2d859	714	if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
mbed714	0:d616ece2d859	715	netif_loop_output(netif, p, dest);
mbed714	0:d616ece2d859	716	}
mbed714	0:d616ece2d859	717	#endif /* LWIP_IGMP */
mbed714	0:d616ece2d859	718	#endif /* ENABLE_LOOPBACK */
mbed714	0:d616ece2d859	719	#if IP_FRAG
mbed714	0:d616ece2d859	720	/* don't fragment if interface has mtu set to 0 [loopif] */
mbed714	0:d616ece2d859	721	if (netif->mtu && (p->tot_len > netif->mtu)) {
mbed714	0:d616ece2d859	722	return ip_frag(p, netif, dest);
mbed714	0:d616ece2d859	723	}
mbed714	0:d616ece2d859	724	#endif /* IP_FRAG */
mbed714	0:d616ece2d859	725
mbed714	0:d616ece2d859	726	LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
mbed714	0:d616ece2d859	727	return netif->output(netif, p, dest);
mbed714	0:d616ece2d859	728	}
mbed714	0:d616ece2d859	729
mbed714	0:d616ece2d859	730	/**
mbed714	0:d616ece2d859	731	* Simple interface to ip_output_if. It finds the outgoing network
mbed714	0:d616ece2d859	732	* interface and calls upon ip_output_if to do the actual work.
mbed714	0:d616ece2d859	733	*
mbed714	0:d616ece2d859	734	* @param p the packet to send (p->payload points to the data, e.g. next
mbed714	0:d616ece2d859	735	protocol header; if dest == IP_HDRINCL, p already includes an IP
mbed714	0:d616ece2d859	736	header and p->payload points to that IP header)
mbed714	0:d616ece2d859	737	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
mbed714	0:d616ece2d859	738	* IP address of the netif used to send is used as source address)
mbed714	0:d616ece2d859	739	* @param dest the destination IP address to send the packet to
mbed714	0:d616ece2d859	740	* @param ttl the TTL value to be set in the IP header
mbed714	0:d616ece2d859	741	* @param tos the TOS value to be set in the IP header
mbed714	0:d616ece2d859	742	* @param proto the PROTOCOL to be set in the IP header
mbed714	0:d616ece2d859	743	*
mbed714	0:d616ece2d859	744	* @return ERR_RTE if no route is found
mbed714	0:d616ece2d859	745	* see ip_output_if() for more return values
mbed714	0:d616ece2d859	746	*/
mbed714	0:d616ece2d859	747	err_t
mbed714	0:d616ece2d859	748	ip_output(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
mbed714	0:d616ece2d859	749	u8_t ttl, u8_t tos, u8_t proto)
mbed714	0:d616ece2d859	750	{
mbed714	0:d616ece2d859	751	struct netif *netif;
mbed714	0:d616ece2d859	752
mbed714	0:d616ece2d859	753	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
mbed714	0:d616ece2d859	754	gets altered as the packet is passed down the stack */
mbed714	0:d616ece2d859	755	LWIP_ASSERT("p->ref == 1", p->ref == 1);
mbed714	0:d616ece2d859	756
mbed714	0:d616ece2d859	757	if ((netif = ip_route(dest)) == NULL) {
mbed714	0:d616ece2d859	758	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
mbed714	0:d616ece2d859	759	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
mbed714	0:d616ece2d859	760	IP_STATS_INC(ip.rterr);
mbed714	0:d616ece2d859	761	return ERR_RTE;
mbed714	0:d616ece2d859	762	}
mbed714	0:d616ece2d859	763
mbed714	0:d616ece2d859	764	return ip_output_if(p, src, dest, ttl, tos, proto, netif);
mbed714	0:d616ece2d859	765	}
mbed714	0:d616ece2d859	766
mbed714	0:d616ece2d859	767	#if LWIP_NETIF_HWADDRHINT
mbed714	0:d616ece2d859	768	/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
mbed714	0:d616ece2d859	769	* before calling ip_output_if.
mbed714	0:d616ece2d859	770	*
mbed714	0:d616ece2d859	771	* @param p the packet to send (p->payload points to the data, e.g. next
mbed714	0:d616ece2d859	772	protocol header; if dest == IP_HDRINCL, p already includes an IP
mbed714	0:d616ece2d859	773	header and p->payload points to that IP header)
mbed714	0:d616ece2d859	774	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
mbed714	0:d616ece2d859	775	* IP address of the netif used to send is used as source address)
mbed714	0:d616ece2d859	776	* @param dest the destination IP address to send the packet to
mbed714	0:d616ece2d859	777	* @param ttl the TTL value to be set in the IP header
mbed714	0:d616ece2d859	778	* @param tos the TOS value to be set in the IP header
mbed714	0:d616ece2d859	779	* @param proto the PROTOCOL to be set in the IP header
mbed714	0:d616ece2d859	780	* @param addr_hint address hint pointer set to netif->addr_hint before
mbed714	0:d616ece2d859	781	* calling ip_output_if()
mbed714	0:d616ece2d859	782	*
mbed714	0:d616ece2d859	783	* @return ERR_RTE if no route is found
mbed714	0:d616ece2d859	784	* see ip_output_if() for more return values
mbed714	0:d616ece2d859	785	*/
mbed714	0:d616ece2d859	786	err_t
mbed714	0:d616ece2d859	787	ip_output_hinted(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
mbed714	0:d616ece2d859	788	u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
mbed714	0:d616ece2d859	789	{
mbed714	0:d616ece2d859	790	struct netif *netif;
mbed714	0:d616ece2d859	791	err_t err;
mbed714	0:d616ece2d859	792
mbed714	0:d616ece2d859	793	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
mbed714	0:d616ece2d859	794	gets altered as the packet is passed down the stack */
mbed714	0:d616ece2d859	795	LWIP_ASSERT("p->ref == 1", p->ref == 1);
mbed714	0:d616ece2d859	796
mbed714	0:d616ece2d859	797	if ((netif = ip_route(dest)) == NULL) {
mbed714	0:d616ece2d859	798	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
mbed714	0:d616ece2d859	799	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
mbed714	0:d616ece2d859	800	IP_STATS_INC(ip.rterr);
mbed714	0:d616ece2d859	801	return ERR_RTE;
mbed714	0:d616ece2d859	802	}
mbed714	0:d616ece2d859	803
mbed714	0:d616ece2d859	804	netif->addr_hint = addr_hint;
mbed714	0:d616ece2d859	805	err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
mbed714	0:d616ece2d859	806	netif->addr_hint = NULL;
mbed714	0:d616ece2d859	807
mbed714	0:d616ece2d859	808	return err;
mbed714	0:d616ece2d859	809	}
mbed714	0:d616ece2d859	810	#endif /* LWIP_NETIF_HWADDRHINT*/
mbed714	0:d616ece2d859	811
mbed714	0:d616ece2d859	812	#if IP_DEBUG
mbed714	0:d616ece2d859	813	/* Print an IP header by using LWIP_DEBUGF
mbed714	0:d616ece2d859	814	* @param p an IP packet, p->payload pointing to the IP header
mbed714	0:d616ece2d859	815	*/
mbed714	0:d616ece2d859	816	void
mbed714	0:d616ece2d859	817	ip_debug_print(struct pbuf *p)
mbed714	0:d616ece2d859	818	{
mbed714	0:d616ece2d859	819	struct ip_hdr iphdr = (struct ip_hdr )p->payload;
mbed714	0:d616ece2d859	820	u8_t *payload;
mbed714	0:d616ece2d859	821
mbed714	0:d616ece2d859	822	payload = (u8_t *)iphdr + IP_HLEN;
mbed714	0:d616ece2d859	823
mbed714	0:d616ece2d859	824	LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
mbed714	0:d616ece2d859	825	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
mbed714	0:d616ece2d859	826	LWIP_DEBUGF(IP_DEBUG, ("\|%2"S16_F" \|%2"S16_F" \| 0x%02"X16_F" \| %5"U16_F" \| (v, hl, tos, len)\n",
mbed714	0:d616ece2d859	827	IPH_V(iphdr),
mbed714	0:d616ece2d859	828	IPH_HL(iphdr),
mbed714	0:d616ece2d859	829	IPH_TOS(iphdr),
mbed714	0:d616ece2d859	830	ntohs(IPH_LEN(iphdr))));
mbed714	0:d616ece2d859	831	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
mbed714	0:d616ece2d859	832	LWIP_DEBUGF(IP_DEBUG, ("\| %5"U16_F" \|%"U16_F"%"U16_F"%"U16_F"\| %4"U16_F" \| (id, flags, offset)\n",
mbed714	0:d616ece2d859	833	ntohs(IPH_ID(iphdr)),
mbed714	0:d616ece2d859	834	ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
mbed714	0:d616ece2d859	835	ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
mbed714	0:d616ece2d859	836	ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
mbed714	0:d616ece2d859	837	ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
mbed714	0:d616ece2d859	838	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
mbed714	0:d616ece2d859	839	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| 0x%04"X16_F" \| (ttl, proto, chksum)\n",
mbed714	0:d616ece2d859	840	IPH_TTL(iphdr),
mbed714	0:d616ece2d859	841	IPH_PROTO(iphdr),
mbed714	0:d616ece2d859	842	ntohs(IPH_CHKSUM(iphdr))));
mbed714	0:d616ece2d859	843	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
mbed714	0:d616ece2d859	844	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (src)\n",
mbed714	0:d616ece2d859	845	ip4_addr1_16(&iphdr->src),
mbed714	0:d616ece2d859	846	ip4_addr2_16(&iphdr->src),
mbed714	0:d616ece2d859	847	ip4_addr3_16(&iphdr->src),
mbed714	0:d616ece2d859	848	ip4_addr4_16(&iphdr->src)));
mbed714	0:d616ece2d859	849	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
mbed714	0:d616ece2d859	850	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (dest)\n",
mbed714	0:d616ece2d859	851	ip4_addr1_16(&iphdr->dest),
mbed714	0:d616ece2d859	852	ip4_addr2_16(&iphdr->dest),
mbed714	0:d616ece2d859	853	ip4_addr3_16(&iphdr->dest),
mbed714	0:d616ece2d859	854	ip4_addr4_16(&iphdr->dest)));
mbed714	0:d616ece2d859	855	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
mbed714	0:d616ece2d859	856	}
mbed714	0:d616ece2d859	857	#endif /* IP_DEBUG */

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Type:	Library
Created:	18 Sep 2010
Imports:	1
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	0
Followers:	1

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lwip/core/ipv4/ip.c@0:d616ece2d859, 2010-09-18 (annotated)

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