ZG2100NetIfSource - ZG2100 Network interface source

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ZG2100 Network interface source

lwip/core/ipv4/ip.c@1:3a7c15057192, 2010-08-06 (annotated)

Committer:: donatien
Date:: Fri Aug 06 10:23:41 2010 +0000
Revision:: 1:3a7c15057192
Parent:: 0:b802fc31f1db

Who changed what in which revision?

User	Revision	Line number	New contents of line
donatien	0:b802fc31f1db	1	/**
donatien	0:b802fc31f1db	2	* @file
donatien	0:b802fc31f1db	3	* This is the IPv4 layer implementation for incoming and outgoing IP traffic.
donatien	0:b802fc31f1db	4	*
donatien	0:b802fc31f1db	5	* @see ip_frag.c
donatien	0:b802fc31f1db	6	*
donatien	0:b802fc31f1db	7	*/
donatien	0:b802fc31f1db	8
donatien	0:b802fc31f1db	9	/*
donatien	0:b802fc31f1db	10	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
donatien	0:b802fc31f1db	11	* All rights reserved.
donatien	0:b802fc31f1db	12	*
donatien	0:b802fc31f1db	13	* Redistribution and use in source and binary forms, with or without modification,
donatien	0:b802fc31f1db	14	* are permitted provided that the following conditions are met:
donatien	0:b802fc31f1db	15	*
donatien	0:b802fc31f1db	16	* 1. Redistributions of source code must retain the above copyright notice,
donatien	0:b802fc31f1db	17	* this list of conditions and the following disclaimer.
donatien	0:b802fc31f1db	18	* 2. Redistributions in binary form must reproduce the above copyright notice,
donatien	0:b802fc31f1db	19	* this list of conditions and the following disclaimer in the documentation
donatien	0:b802fc31f1db	20	* and/or other materials provided with the distribution.
donatien	0:b802fc31f1db	21	* 3. The name of the author may not be used to endorse or promote products
donatien	0:b802fc31f1db	22	* derived from this software without specific prior written permission.
donatien	0:b802fc31f1db	23	*
donatien	0:b802fc31f1db	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
donatien	0:b802fc31f1db	25	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
donatien	0:b802fc31f1db	26	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
donatien	0:b802fc31f1db	27	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
donatien	0:b802fc31f1db	28	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
donatien	0:b802fc31f1db	29	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
donatien	0:b802fc31f1db	30	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
donatien	0:b802fc31f1db	31	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
donatien	0:b802fc31f1db	32	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
donatien	0:b802fc31f1db	33	* OF SUCH DAMAGE.
donatien	0:b802fc31f1db	34	*
donatien	0:b802fc31f1db	35	* This file is part of the lwIP TCP/IP stack.
donatien	0:b802fc31f1db	36	*
donatien	0:b802fc31f1db	37	* Author: Adam Dunkels <adam@sics.se>
donatien	0:b802fc31f1db	38	*
donatien	0:b802fc31f1db	39	*/
donatien	0:b802fc31f1db	40
donatien	0:b802fc31f1db	41	#include "lwip/opt.h"
donatien	0:b802fc31f1db	42	#include "lwip/ip.h"
donatien	0:b802fc31f1db	43	#include "lwip/def.h"
donatien	0:b802fc31f1db	44	#include "lwip/mem.h"
donatien	0:b802fc31f1db	45	#include "lwip/ip_frag.h"
donatien	0:b802fc31f1db	46	#include "lwip/inet_chksum.h"
donatien	0:b802fc31f1db	47	#include "lwip/netif.h"
donatien	0:b802fc31f1db	48	#include "lwip/icmp.h"
donatien	0:b802fc31f1db	49	#include "lwip/igmp.h"
donatien	0:b802fc31f1db	50	#include "lwip/raw.h"
donatien	0:b802fc31f1db	51	#include "lwip/udp.h"
donatien	0:b802fc31f1db	52	#include "lwip/tcp_impl.h"
donatien	0:b802fc31f1db	53	#include "lwip/snmp.h"
donatien	0:b802fc31f1db	54	#include "lwip/dhcp.h"
donatien	0:b802fc31f1db	55	#include "lwip/autoip.h"
donatien	0:b802fc31f1db	56	#include "lwip/stats.h"
donatien	0:b802fc31f1db	57	#include "arch/perf.h"
donatien	0:b802fc31f1db	58
donatien	0:b802fc31f1db	59	#include <string.h>
donatien	0:b802fc31f1db	60
donatien	1:3a7c15057192	61	/** Set this to 0 in the rare case of wanting to call an extra function to
donatien	1:3a7c15057192	62	* generate the IP checksum (in contrast to calculating it on-the-fly). */
donatien	1:3a7c15057192	63	#ifndef LWIP_INLINE_IP_CHKSUM
donatien	1:3a7c15057192	64	#define LWIP_INLINE_IP_CHKSUM 1
donatien	1:3a7c15057192	65	#endif
donatien	1:3a7c15057192	66	#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
donatien	1:3a7c15057192	67	#define CHECKSUM_GEN_IP_INLINE 1
donatien	1:3a7c15057192	68	#else
donatien	1:3a7c15057192	69	#define CHECKSUM_GEN_IP_INLINE 0
donatien	1:3a7c15057192	70	#endif
donatien	1:3a7c15057192	71
donatien	1:3a7c15057192	72	#if LWIP_DHCP \|\| defined(LWIP_IP_ACCEPT_UDP_PORT)
donatien	1:3a7c15057192	73	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
donatien	1:3a7c15057192	74
donatien	1:3a7c15057192	75	/** Some defines for DHCP to let link-layer-addressed packets through while the
donatien	1:3a7c15057192	76	* netif is down.
donatien	1:3a7c15057192	77	* To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT
donatien	1:3a7c15057192	78	* to return 1 if the port is accepted and 0 if the port is not accepted.
donatien	1:3a7c15057192	79	*/
donatien	1:3a7c15057192	80	#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
donatien	1:3a7c15057192	81	/* accept DHCP client port and custom port */
donatien	1:3a7c15057192	82	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(DHCP_CLIENT_PORT)) \
donatien	1:3a7c15057192	83	\|\| (LWIP_IP_ACCEPT_UDP_PORT(port)))
donatien	1:3a7c15057192	84	#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
donatien	1:3a7c15057192	85	/* accept custom port only */
donatien	1:3a7c15057192	86	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(dst_port))
donatien	1:3a7c15057192	87	#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
donatien	1:3a7c15057192	88	/* accept DHCP client port only */
donatien	1:3a7c15057192	89	#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(DHCP_CLIENT_PORT))
donatien	1:3a7c15057192	90	#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
donatien	1:3a7c15057192	91
donatien	1:3a7c15057192	92	#else /* LWIP_DHCP */
donatien	1:3a7c15057192	93	#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
donatien	1:3a7c15057192	94	#endif /* LWIP_DHCP */
donatien	1:3a7c15057192	95
donatien	0:b802fc31f1db	96	/**
donatien	0:b802fc31f1db	97	* The interface that provided the packet for the current callback
donatien	0:b802fc31f1db	98	* invocation.
donatien	0:b802fc31f1db	99	*/
donatien	0:b802fc31f1db	100	struct netif *current_netif;
donatien	0:b802fc31f1db	101
donatien	0:b802fc31f1db	102	/**
donatien	0:b802fc31f1db	103	* Header of the input packet currently being processed.
donatien	0:b802fc31f1db	104	*/
donatien	0:b802fc31f1db	105	const struct ip_hdr *current_header;
donatien	1:3a7c15057192	106	/** Source IP address of current_header */
donatien	1:3a7c15057192	107	ip_addr_t current_iphdr_src;
donatien	1:3a7c15057192	108	/** Destination IP address of current_header */
donatien	1:3a7c15057192	109	ip_addr_t current_iphdr_dest;
donatien	1:3a7c15057192	110
donatien	1:3a7c15057192	111	/** The IP header ID of the next outgoing IP packet */
donatien	1:3a7c15057192	112	static u16_t ip_id;
donatien	0:b802fc31f1db	113
donatien	0:b802fc31f1db	114	/**
donatien	0:b802fc31f1db	115	* Finds the appropriate network interface for a given IP address. It
donatien	0:b802fc31f1db	116	* searches the list of network interfaces linearly. A match is found
donatien	0:b802fc31f1db	117	* if the masked IP address of the network interface equals the masked
donatien	0:b802fc31f1db	118	* IP address given to the function.
donatien	0:b802fc31f1db	119	*
donatien	0:b802fc31f1db	120	* @param dest the destination IP address for which to find the route
donatien	0:b802fc31f1db	121	* @return the netif on which to send to reach dest
donatien	0:b802fc31f1db	122	*/
donatien	0:b802fc31f1db	123	struct netif *
donatien	0:b802fc31f1db	124	ip_route(ip_addr_t *dest)
donatien	0:b802fc31f1db	125	{
donatien	0:b802fc31f1db	126	struct netif *netif;
donatien	0:b802fc31f1db	127
donatien	0:b802fc31f1db	128	/* iterate through netifs */
donatien	0:b802fc31f1db	129	for(netif = netif_list; netif != NULL; netif = netif->next) {
donatien	0:b802fc31f1db	130	/* network mask matches? */
donatien	0:b802fc31f1db	131	if (netif_is_up(netif)) {
donatien	0:b802fc31f1db	132	if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
donatien	0:b802fc31f1db	133	/* return netif on which to forward IP packet */
donatien	0:b802fc31f1db	134	return netif;
donatien	0:b802fc31f1db	135	}
donatien	0:b802fc31f1db	136	}
donatien	0:b802fc31f1db	137	}
donatien	0:b802fc31f1db	138	if ((netif_default == NULL) \|\| (!netif_is_up(netif_default))) {
donatien	0:b802fc31f1db	139	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
donatien	0:b802fc31f1db	140	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
donatien	0:b802fc31f1db	141	IP_STATS_INC(ip.rterr);
donatien	0:b802fc31f1db	142	snmp_inc_ipoutnoroutes();
donatien	0:b802fc31f1db	143	return NULL;
donatien	0:b802fc31f1db	144	}
donatien	0:b802fc31f1db	145	/* no matching netif found, use default netif */
donatien	0:b802fc31f1db	146	return netif_default;
donatien	0:b802fc31f1db	147	}
donatien	0:b802fc31f1db	148
donatien	0:b802fc31f1db	149	#if IP_FORWARD
donatien	0:b802fc31f1db	150	/**
donatien	0:b802fc31f1db	151	* Forwards an IP packet. It finds an appropriate route for the
donatien	0:b802fc31f1db	152	* packet, decrements the TTL value of the packet, adjusts the
donatien	0:b802fc31f1db	153	* checksum and outputs the packet on the appropriate interface.
donatien	0:b802fc31f1db	154	*
donatien	0:b802fc31f1db	155	* @param p the packet to forward (p->payload points to IP header)
donatien	0:b802fc31f1db	156	* @param iphdr the IP header of the input packet
donatien	0:b802fc31f1db	157	* @param inp the netif on which this packet was received
donatien	0:b802fc31f1db	158	*/
donatien	1:3a7c15057192	159	static void
donatien	0:b802fc31f1db	160	ip_forward(struct pbuf p, struct ip_hdr iphdr, struct netif *inp)
donatien	0:b802fc31f1db	161	{
donatien	0:b802fc31f1db	162	struct netif *netif;
donatien	0:b802fc31f1db	163
donatien	0:b802fc31f1db	164	PERF_START;
donatien	0:b802fc31f1db	165
donatien	0:b802fc31f1db	166	/* RFC3927 2.7: do not forward link-local addresses */
donatien	1:3a7c15057192	167	if (ip_addr_islinklocal(&current_iphdr_dest)) {
donatien	0:b802fc31f1db	168	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
donatien	1:3a7c15057192	169	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
donatien	1:3a7c15057192	170	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
donatien	1:3a7c15057192	171	goto return_noroute;
donatien	0:b802fc31f1db	172	}
donatien	0:b802fc31f1db	173
donatien	0:b802fc31f1db	174	/* Find network interface where to forward this IP packet to. */
donatien	1:3a7c15057192	175	netif = ip_route(&current_iphdr_dest);
donatien	0:b802fc31f1db	176	if (netif == NULL) {
donatien	0:b802fc31f1db	177	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
donatien	1:3a7c15057192	178	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
donatien	1:3a7c15057192	179	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
donatien	1:3a7c15057192	180	goto return_noroute;
donatien	0:b802fc31f1db	181	}
donatien	0:b802fc31f1db	182	/* Do not forward packets onto the same network interface on which
donatien	0:b802fc31f1db	183	* they arrived. */
donatien	0:b802fc31f1db	184	if (netif == inp) {
donatien	0:b802fc31f1db	185	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
donatien	1:3a7c15057192	186	goto return_noroute;
donatien	0:b802fc31f1db	187	}
donatien	0:b802fc31f1db	188
donatien	0:b802fc31f1db	189	/* decrement TTL */
donatien	0:b802fc31f1db	190	IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
donatien	0:b802fc31f1db	191	/* send ICMP if TTL == 0 */
donatien	0:b802fc31f1db	192	if (IPH_TTL(iphdr) == 0) {
donatien	0:b802fc31f1db	193	snmp_inc_ipinhdrerrors();
donatien	0:b802fc31f1db	194	#if LWIP_ICMP
donatien	0:b802fc31f1db	195	/* Don't send ICMP messages in response to ICMP messages */
donatien	0:b802fc31f1db	196	if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
donatien	0:b802fc31f1db	197	icmp_time_exceeded(p, ICMP_TE_TTL);
donatien	0:b802fc31f1db	198	}
donatien	0:b802fc31f1db	199	#endif /* LWIP_ICMP */
donatien	1:3a7c15057192	200	return;
donatien	0:b802fc31f1db	201	}
donatien	0:b802fc31f1db	202
donatien	0:b802fc31f1db	203	/* Incrementally update the IP checksum. */
donatien	1:3a7c15057192	204	if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffff - 0x100)) {
donatien	1:3a7c15057192	205	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
donatien	0:b802fc31f1db	206	} else {
donatien	1:3a7c15057192	207	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
donatien	0:b802fc31f1db	208	}
donatien	0:b802fc31f1db	209
donatien	0:b802fc31f1db	210	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
donatien	1:3a7c15057192	211	ip4_addr1_16(&current_iphdr_dest), ip4_addr2_16(&current_iphdr_dest),
donatien	1:3a7c15057192	212	ip4_addr3_16(&current_iphdr_dest), ip4_addr4_16(&current_iphdr_dest)));
donatien	0:b802fc31f1db	213
donatien	0:b802fc31f1db	214	IP_STATS_INC(ip.fw);
donatien	0:b802fc31f1db	215	IP_STATS_INC(ip.xmit);
donatien	0:b802fc31f1db	216	snmp_inc_ipforwdatagrams();
donatien	0:b802fc31f1db	217
donatien	0:b802fc31f1db	218	PERF_STOP("ip_forward");
donatien	0:b802fc31f1db	219	/* transmit pbuf on chosen interface */
donatien	1:3a7c15057192	220	netif->output(netif, p, &current_iphdr_dest);
donatien	1:3a7c15057192	221	return;
donatien	1:3a7c15057192	222	return_noroute:
donatien	1:3a7c15057192	223	snmp_inc_ipoutnoroutes();
donatien	0:b802fc31f1db	224	}
donatien	0:b802fc31f1db	225	#endif /* IP_FORWARD */
donatien	0:b802fc31f1db	226
donatien	0:b802fc31f1db	227	/**
donatien	0:b802fc31f1db	228	* This function is called by the network interface device driver when
donatien	0:b802fc31f1db	229	* an IP packet is received. The function does the basic checks of the
donatien	0:b802fc31f1db	230	* IP header such as packet size being at least larger than the header
donatien	0:b802fc31f1db	231	* size etc. If the packet was not destined for us, the packet is
donatien	0:b802fc31f1db	232	* forwarded (using ip_forward). The IP checksum is always checked.
donatien	0:b802fc31f1db	233	*
donatien	0:b802fc31f1db	234	* Finally, the packet is sent to the upper layer protocol input function.
donatien	0:b802fc31f1db	235	*
donatien	0:b802fc31f1db	236	* @param p the received IP packet (p->payload points to IP header)
donatien	0:b802fc31f1db	237	* @param inp the netif on which this packet was received
donatien	0:b802fc31f1db	238	* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
donatien	0:b802fc31f1db	239	* processed, but currently always returns ERR_OK)
donatien	0:b802fc31f1db	240	*/
donatien	0:b802fc31f1db	241	err_t
donatien	0:b802fc31f1db	242	ip_input(struct pbuf p, struct netif inp)
donatien	0:b802fc31f1db	243	{
donatien	0:b802fc31f1db	244	struct ip_hdr *iphdr;
donatien	0:b802fc31f1db	245	struct netif *netif;
donatien	0:b802fc31f1db	246	u16_t iphdr_hlen;
donatien	0:b802fc31f1db	247	u16_t iphdr_len;
donatien	1:3a7c15057192	248	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
donatien	0:b802fc31f1db	249	int check_ip_src=1;
donatien	1:3a7c15057192	250	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
donatien	0:b802fc31f1db	251
donatien	0:b802fc31f1db	252	IP_STATS_INC(ip.recv);
donatien	0:b802fc31f1db	253	snmp_inc_ipinreceives();
donatien	0:b802fc31f1db	254
donatien	0:b802fc31f1db	255	/* identify the IP header */
donatien	0:b802fc31f1db	256	iphdr = (struct ip_hdr *)p->payload;
donatien	0:b802fc31f1db	257	if (IPH_V(iphdr) != 4) {
donatien	0:b802fc31f1db	258	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
donatien	0:b802fc31f1db	259	ip_debug_print(p);
donatien	0:b802fc31f1db	260	pbuf_free(p);
donatien	0:b802fc31f1db	261	IP_STATS_INC(ip.err);
donatien	0:b802fc31f1db	262	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	263	snmp_inc_ipinhdrerrors();
donatien	0:b802fc31f1db	264	return ERR_OK;
donatien	0:b802fc31f1db	265	}
donatien	0:b802fc31f1db	266
donatien	0:b802fc31f1db	267	/* obtain IP header length in number of 32-bit words */
donatien	0:b802fc31f1db	268	iphdr_hlen = IPH_HL(iphdr);
donatien	0:b802fc31f1db	269	/* calculate IP header length in bytes */
donatien	0:b802fc31f1db	270	iphdr_hlen *= 4;
donatien	0:b802fc31f1db	271	/* obtain ip length in bytes */
donatien	0:b802fc31f1db	272	iphdr_len = ntohs(IPH_LEN(iphdr));
donatien	0:b802fc31f1db	273
donatien	0:b802fc31f1db	274	/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
donatien	0:b802fc31f1db	275	if ((iphdr_hlen > p->len) \|\| (iphdr_len > p->tot_len)) {
donatien	0:b802fc31f1db	276	if (iphdr_hlen > p->len) {
donatien	0:b802fc31f1db	277	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:b802fc31f1db	278	("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
donatien	0:b802fc31f1db	279	iphdr_hlen, p->len));
donatien	0:b802fc31f1db	280	}
donatien	0:b802fc31f1db	281	if (iphdr_len > p->tot_len) {
donatien	0:b802fc31f1db	282	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:b802fc31f1db	283	("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
donatien	0:b802fc31f1db	284	iphdr_len, p->tot_len));
donatien	0:b802fc31f1db	285	}
donatien	0:b802fc31f1db	286	/* free (drop) packet pbufs */
donatien	0:b802fc31f1db	287	pbuf_free(p);
donatien	0:b802fc31f1db	288	IP_STATS_INC(ip.lenerr);
donatien	0:b802fc31f1db	289	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	290	snmp_inc_ipindiscards();
donatien	0:b802fc31f1db	291	return ERR_OK;
donatien	0:b802fc31f1db	292	}
donatien	0:b802fc31f1db	293
donatien	0:b802fc31f1db	294	/* verify checksum */
donatien	0:b802fc31f1db	295	#if CHECKSUM_CHECK_IP
donatien	0:b802fc31f1db	296	if (inet_chksum(iphdr, iphdr_hlen) != 0) {
donatien	0:b802fc31f1db	297
donatien	0:b802fc31f1db	298	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
donatien	0:b802fc31f1db	299	("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
donatien	0:b802fc31f1db	300	ip_debug_print(p);
donatien	0:b802fc31f1db	301	pbuf_free(p);
donatien	0:b802fc31f1db	302	IP_STATS_INC(ip.chkerr);
donatien	0:b802fc31f1db	303	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	304	snmp_inc_ipinhdrerrors();
donatien	0:b802fc31f1db	305	return ERR_OK;
donatien	0:b802fc31f1db	306	}
donatien	0:b802fc31f1db	307	#endif
donatien	0:b802fc31f1db	308
donatien	0:b802fc31f1db	309	/* Trim pbuf. This should have been done at the netif layer,
donatien	0:b802fc31f1db	310	* but we'll do it anyway just to be sure that its done. */
donatien	0:b802fc31f1db	311	pbuf_realloc(p, iphdr_len);
donatien	0:b802fc31f1db	312
donatien	1:3a7c15057192	313	/* copy IP addresses to aligned ip_addr_t */
donatien	1:3a7c15057192	314	ip_addr_copy(current_iphdr_dest, iphdr->dest);
donatien	1:3a7c15057192	315	ip_addr_copy(current_iphdr_src, iphdr->src);
donatien	1:3a7c15057192	316
donatien	0:b802fc31f1db	317	/* match packet against an interface, i.e. is this packet for us? */
donatien	0:b802fc31f1db	318	#if LWIP_IGMP
donatien	1:3a7c15057192	319	if (ip_addr_ismulticast(&current_iphdr_dest)) {
donatien	1:3a7c15057192	320	if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &current_iphdr_dest))) {
donatien	0:b802fc31f1db	321	netif = inp;
donatien	0:b802fc31f1db	322	} else {
donatien	0:b802fc31f1db	323	netif = NULL;
donatien	0:b802fc31f1db	324	}
donatien	0:b802fc31f1db	325	} else
donatien	0:b802fc31f1db	326	#endif /* LWIP_IGMP */
donatien	0:b802fc31f1db	327	{
donatien	0:b802fc31f1db	328	/* start trying with inp. if that's not acceptable, start walking the
donatien	0:b802fc31f1db	329	list of configured netifs.
donatien	0:b802fc31f1db	330	'first' is used as a boolean to mark whether we started walking the list */
donatien	0:b802fc31f1db	331	int first = 1;
donatien	0:b802fc31f1db	332	netif = inp;
donatien	0:b802fc31f1db	333	do {
donatien	0:b802fc31f1db	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",
donatien	0:b802fc31f1db	335	ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
donatien	0:b802fc31f1db	336	ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
donatien	0:b802fc31f1db	337	ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
donatien	0:b802fc31f1db	338	ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
donatien	0:b802fc31f1db	339
donatien	0:b802fc31f1db	340	/* interface is up and configured? */
donatien	0:b802fc31f1db	341	if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
donatien	0:b802fc31f1db	342	/* unicast to this interface address? */
donatien	1:3a7c15057192	343	if (ip_addr_cmp(&current_iphdr_dest, &(netif->ip_addr)) \|\|
donatien	0:b802fc31f1db	344	/* or broadcast on this interface network address? */
donatien	1:3a7c15057192	345	ip_addr_isbroadcast(&current_iphdr_dest, netif)) {
donatien	0:b802fc31f1db	346	LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
donatien	0:b802fc31f1db	347	netif->name[0], netif->name[1]));
donatien	0:b802fc31f1db	348	/* break out of for loop */
donatien	0:b802fc31f1db	349	break;
donatien	0:b802fc31f1db	350	}
donatien	0:b802fc31f1db	351	#if LWIP_AUTOIP
donatien	0:b802fc31f1db	352	/* connections to link-local addresses must persist after changing
donatien	0:b802fc31f1db	353	the netif's address (RFC3927 ch. 1.9) */
donatien	0:b802fc31f1db	354	if ((netif->autoip != NULL) &&
donatien	1:3a7c15057192	355	ip_addr_cmp(&current_iphdr_dest, &(netif->autoip->llipaddr))) {
donatien	0:b802fc31f1db	356	LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
donatien	0:b802fc31f1db	357	netif->name[0], netif->name[1]));
donatien	0:b802fc31f1db	358	/* break out of for loop */
donatien	0:b802fc31f1db	359	break;
donatien	0:b802fc31f1db	360	}
donatien	0:b802fc31f1db	361	#endif /* LWIP_AUTOIP */
donatien	0:b802fc31f1db	362	}
donatien	0:b802fc31f1db	363	if (first) {
donatien	0:b802fc31f1db	364	first = 0;
donatien	0:b802fc31f1db	365	netif = netif_list;
donatien	0:b802fc31f1db	366	} else {
donatien	0:b802fc31f1db	367	netif = netif->next;
donatien	0:b802fc31f1db	368	}
donatien	0:b802fc31f1db	369	if (netif == inp) {
donatien	0:b802fc31f1db	370	netif = netif->next;
donatien	0:b802fc31f1db	371	}
donatien	0:b802fc31f1db	372	} while(netif != NULL);
donatien	0:b802fc31f1db	373	}
donatien	0:b802fc31f1db	374
donatien	1:3a7c15057192	375	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
donatien	0:b802fc31f1db	376	/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
donatien	0:b802fc31f1db	377	* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
donatien	0:b802fc31f1db	378	* According to RFC 1542 section 3.1.1, referred by RFC 2131).
donatien	1:3a7c15057192	379	*
donatien	1:3a7c15057192	380	* If you want to accept private broadcast communication while a netif is down,
donatien	1:3a7c15057192	381	* define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
donatien	1:3a7c15057192	382	*
donatien	1:3a7c15057192	383	* #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
donatien	0:b802fc31f1db	384	*/
donatien	0:b802fc31f1db	385	if (netif == NULL) {
donatien	0:b802fc31f1db	386	/* remote port is DHCP server? */
donatien	0:b802fc31f1db	387	if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
donatien	1:3a7c15057192	388	struct udp_hdr udphdr = (struct udp_hdr )((u8_t *)iphdr + iphdr_hlen);
donatien	0:b802fc31f1db	389	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
donatien	1:3a7c15057192	390	ntohs(udphdr->dest)));
donatien	1:3a7c15057192	391	if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
donatien	0:b802fc31f1db	392	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
donatien	0:b802fc31f1db	393	netif = inp;
donatien	0:b802fc31f1db	394	check_ip_src = 0;
donatien	0:b802fc31f1db	395	}
donatien	0:b802fc31f1db	396	}
donatien	0:b802fc31f1db	397	}
donatien	1:3a7c15057192	398	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
donatien	0:b802fc31f1db	399
donatien	0:b802fc31f1db	400	/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
donatien	1:3a7c15057192	401	#if IP_ACCEPT_LINK_LAYER_ADDRESSING
donatien	0:b802fc31f1db	402	/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
donatien	1:3a7c15057192	403	if (check_ip_src && !ip_addr_isany(&current_iphdr_src))
donatien	1:3a7c15057192	404	#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
donatien	1:3a7c15057192	405	{ if ((ip_addr_isbroadcast(&current_iphdr_src, inp)) \|\|
donatien	1:3a7c15057192	406	(ip_addr_ismulticast(&current_iphdr_src))) {
donatien	0:b802fc31f1db	407	/* packet source is not valid */
donatien	0:b802fc31f1db	408	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
donatien	0:b802fc31f1db	409	/* free (drop) packet pbufs */
donatien	0:b802fc31f1db	410	pbuf_free(p);
donatien	0:b802fc31f1db	411	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	412	snmp_inc_ipinaddrerrors();
donatien	0:b802fc31f1db	413	snmp_inc_ipindiscards();
donatien	0:b802fc31f1db	414	return ERR_OK;
donatien	0:b802fc31f1db	415	}
donatien	0:b802fc31f1db	416	}
donatien	0:b802fc31f1db	417
donatien	0:b802fc31f1db	418	/* packet not for us? */
donatien	0:b802fc31f1db	419	if (netif == NULL) {
donatien	0:b802fc31f1db	420	/* packet not for us, route or discard */
donatien	0:b802fc31f1db	421	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
donatien	0:b802fc31f1db	422	#if IP_FORWARD
donatien	0:b802fc31f1db	423	/* non-broadcast packet? */
donatien	1:3a7c15057192	424	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp)) {
donatien	0:b802fc31f1db	425	/* try to forward IP packet on (other) interfaces */
donatien	0:b802fc31f1db	426	ip_forward(p, iphdr, inp);
donatien	0:b802fc31f1db	427	} else
donatien	0:b802fc31f1db	428	#endif /* IP_FORWARD */
donatien	0:b802fc31f1db	429	{
donatien	0:b802fc31f1db	430	snmp_inc_ipinaddrerrors();
donatien	0:b802fc31f1db	431	snmp_inc_ipindiscards();
donatien	0:b802fc31f1db	432	}
donatien	0:b802fc31f1db	433	pbuf_free(p);
donatien	0:b802fc31f1db	434	return ERR_OK;
donatien	0:b802fc31f1db	435	}
donatien	0:b802fc31f1db	436	/* packet consists of multiple fragments? */
donatien	1:3a7c15057192	437	if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK \| IP_MF)) != 0) {
donatien	0:b802fc31f1db	438	#if IP_REASSEMBLY /* packet fragment reassembly code present? */
donatien	0:b802fc31f1db	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",
donatien	1:3a7c15057192	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));
donatien	0:b802fc31f1db	441	/* reassemble the packet*/
donatien	0:b802fc31f1db	442	p = ip_reass(p);
donatien	0:b802fc31f1db	443	/* packet not fully reassembled yet? */
donatien	0:b802fc31f1db	444	if (p == NULL) {
donatien	0:b802fc31f1db	445	return ERR_OK;
donatien	0:b802fc31f1db	446	}
donatien	0:b802fc31f1db	447	iphdr = (struct ip_hdr *)p->payload;
donatien	0:b802fc31f1db	448	#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
donatien	0:b802fc31f1db	449	pbuf_free(p);
donatien	0:b802fc31f1db	450	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
donatien	0:b802fc31f1db	451	ntohs(IPH_OFFSET(iphdr))));
donatien	0:b802fc31f1db	452	IP_STATS_INC(ip.opterr);
donatien	0:b802fc31f1db	453	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	454	/* unsupported protocol feature */
donatien	0:b802fc31f1db	455	snmp_inc_ipinunknownprotos();
donatien	0:b802fc31f1db	456	return ERR_OK;
donatien	0:b802fc31f1db	457	#endif /* IP_REASSEMBLY */
donatien	0:b802fc31f1db	458	}
donatien	0:b802fc31f1db	459
donatien	0:b802fc31f1db	460	#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
donatien	0:b802fc31f1db	461
donatien	0:b802fc31f1db	462	#if LWIP_IGMP
donatien	0:b802fc31f1db	463	/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
donatien	0:b802fc31f1db	464	if((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
donatien	0:b802fc31f1db	465	#else
donatien	0:b802fc31f1db	466	if (iphdr_hlen > IP_HLEN) {
donatien	0:b802fc31f1db	467	#endif /* LWIP_IGMP */
donatien	0:b802fc31f1db	468	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
donatien	0:b802fc31f1db	469	pbuf_free(p);
donatien	0:b802fc31f1db	470	IP_STATS_INC(ip.opterr);
donatien	0:b802fc31f1db	471	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	472	/* unsupported protocol feature */
donatien	0:b802fc31f1db	473	snmp_inc_ipinunknownprotos();
donatien	0:b802fc31f1db	474	return ERR_OK;
donatien	0:b802fc31f1db	475	}
donatien	0:b802fc31f1db	476	#endif /* IP_OPTIONS_ALLOWED == 0 */
donatien	0:b802fc31f1db	477
donatien	0:b802fc31f1db	478	/* send to upper layers */
donatien	0:b802fc31f1db	479	LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
donatien	0:b802fc31f1db	480	ip_debug_print(p);
donatien	0:b802fc31f1db	481	LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
donatien	0:b802fc31f1db	482
donatien	0:b802fc31f1db	483	current_netif = inp;
donatien	0:b802fc31f1db	484	current_header = iphdr;
donatien	0:b802fc31f1db	485
donatien	0:b802fc31f1db	486	#if LWIP_RAW
donatien	0:b802fc31f1db	487	/* raw input did not eat the packet? */
donatien	0:b802fc31f1db	488	if (raw_input(p, inp) == 0)
donatien	0:b802fc31f1db	489	#endif /* LWIP_RAW */
donatien	0:b802fc31f1db	490	{
donatien	0:b802fc31f1db	491
donatien	0:b802fc31f1db	492	switch (IPH_PROTO(iphdr)) {
donatien	0:b802fc31f1db	493	#if LWIP_UDP
donatien	0:b802fc31f1db	494	case IP_PROTO_UDP:
donatien	0:b802fc31f1db	495	#if LWIP_UDPLITE
donatien	0:b802fc31f1db	496	case IP_PROTO_UDPLITE:
donatien	0:b802fc31f1db	497	#endif /* LWIP_UDPLITE */
donatien	0:b802fc31f1db	498	snmp_inc_ipindelivers();
donatien	0:b802fc31f1db	499	udp_input(p, inp);
donatien	0:b802fc31f1db	500	break;
donatien	0:b802fc31f1db	501	#endif /* LWIP_UDP */
donatien	0:b802fc31f1db	502	#if LWIP_TCP
donatien	0:b802fc31f1db	503	case IP_PROTO_TCP:
donatien	0:b802fc31f1db	504	snmp_inc_ipindelivers();
donatien	0:b802fc31f1db	505	tcp_input(p, inp);
donatien	0:b802fc31f1db	506	break;
donatien	0:b802fc31f1db	507	#endif /* LWIP_TCP */
donatien	0:b802fc31f1db	508	#if LWIP_ICMP
donatien	0:b802fc31f1db	509	case IP_PROTO_ICMP:
donatien	0:b802fc31f1db	510	snmp_inc_ipindelivers();
donatien	0:b802fc31f1db	511	icmp_input(p, inp);
donatien	0:b802fc31f1db	512	break;
donatien	0:b802fc31f1db	513	#endif /* LWIP_ICMP */
donatien	0:b802fc31f1db	514	#if LWIP_IGMP
donatien	0:b802fc31f1db	515	case IP_PROTO_IGMP:
donatien	1:3a7c15057192	516	igmp_input(p, inp, &current_iphdr_dest);
donatien	0:b802fc31f1db	517	break;
donatien	0:b802fc31f1db	518	#endif /* LWIP_IGMP */
donatien	0:b802fc31f1db	519	default:
donatien	0:b802fc31f1db	520	#if LWIP_ICMP
donatien	0:b802fc31f1db	521	/* send ICMP destination protocol unreachable unless is was a broadcast */
donatien	1:3a7c15057192	522	if (!ip_addr_isbroadcast(&current_iphdr_dest, inp) &&
donatien	1:3a7c15057192	523	!ip_addr_ismulticast(&current_iphdr_dest)) {
donatien	0:b802fc31f1db	524	p->payload = iphdr;
donatien	0:b802fc31f1db	525	icmp_dest_unreach(p, ICMP_DUR_PROTO);
donatien	0:b802fc31f1db	526	}
donatien	0:b802fc31f1db	527	#endif /* LWIP_ICMP */
donatien	0:b802fc31f1db	528	pbuf_free(p);
donatien	0:b802fc31f1db	529
donatien	0:b802fc31f1db	530	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
donatien	0:b802fc31f1db	531
donatien	0:b802fc31f1db	532	IP_STATS_INC(ip.proterr);
donatien	0:b802fc31f1db	533	IP_STATS_INC(ip.drop);
donatien	0:b802fc31f1db	534	snmp_inc_ipinunknownprotos();
donatien	0:b802fc31f1db	535	}
donatien	0:b802fc31f1db	536	}
donatien	0:b802fc31f1db	537
donatien	0:b802fc31f1db	538	current_netif = NULL;
donatien	0:b802fc31f1db	539	current_header = NULL;
donatien	1:3a7c15057192	540	ip_addr_set_any(&current_iphdr_src);
donatien	1:3a7c15057192	541	ip_addr_set_any(&current_iphdr_dest);
donatien	0:b802fc31f1db	542
donatien	0:b802fc31f1db	543	return ERR_OK;
donatien	0:b802fc31f1db	544	}
donatien	0:b802fc31f1db	545
donatien	0:b802fc31f1db	546	/**
donatien	0:b802fc31f1db	547	* Sends an IP packet on a network interface. This function constructs
donatien	0:b802fc31f1db	548	* the IP header and calculates the IP header checksum. If the source
donatien	0:b802fc31f1db	549	* IP address is NULL, the IP address of the outgoing network
donatien	0:b802fc31f1db	550	* interface is filled in as source address.
donatien	0:b802fc31f1db	551	* If the destination IP address is IP_HDRINCL, p is assumed to already
donatien	0:b802fc31f1db	552	* include an IP header and p->payload points to it instead of the data.
donatien	0:b802fc31f1db	553	*
donatien	0:b802fc31f1db	554	* @param p the packet to send (p->payload points to the data, e.g. next
donatien	0:b802fc31f1db	555	protocol header; if dest == IP_HDRINCL, p already includes an IP
donatien	0:b802fc31f1db	556	header and p->payload points to that IP header)
donatien	0:b802fc31f1db	557	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
donatien	0:b802fc31f1db	558	* IP address of the netif used to send is used as source address)
donatien	0:b802fc31f1db	559	* @param dest the destination IP address to send the packet to
donatien	0:b802fc31f1db	560	* @param ttl the TTL value to be set in the IP header
donatien	0:b802fc31f1db	561	* @param tos the TOS value to be set in the IP header
donatien	0:b802fc31f1db	562	* @param proto the PROTOCOL to be set in the IP header
donatien	0:b802fc31f1db	563	* @param netif the netif on which to send this packet
donatien	0:b802fc31f1db	564	* @return ERR_OK if the packet was sent OK
donatien	0:b802fc31f1db	565	* ERR_BUF if p doesn't have enough space for IP/LINK headers
donatien	0:b802fc31f1db	566	* returns errors returned by netif->output
donatien	0:b802fc31f1db	567	*
donatien	0:b802fc31f1db	568	* @note ip_id: RFC791 "some host may be able to simply use
donatien	0:b802fc31f1db	569	* unique identifiers independent of destination"
donatien	0:b802fc31f1db	570	*/
donatien	0:b802fc31f1db	571	err_t
donatien	0:b802fc31f1db	572	ip_output_if(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
donatien	0:b802fc31f1db	573	u8_t ttl, u8_t tos,
donatien	0:b802fc31f1db	574	u8_t proto, struct netif *netif)
donatien	0:b802fc31f1db	575	{
donatien	0:b802fc31f1db	576	#if IP_OPTIONS_SEND
donatien	0:b802fc31f1db	577	return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
donatien	0:b802fc31f1db	578	}
donatien	0:b802fc31f1db	579
donatien	0:b802fc31f1db	580	/**
donatien	0:b802fc31f1db	581	* Same as ip_output_if() but with the possibility to include IP options:
donatien	0:b802fc31f1db	582	*
donatien	0:b802fc31f1db	583	* @ param ip_options pointer to the IP options, copied into the IP header
donatien	0:b802fc31f1db	584	* @ param optlen length of ip_options
donatien	0:b802fc31f1db	585	*/
donatien	0:b802fc31f1db	586	err_t ip_output_if_opt(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
donatien	0:b802fc31f1db	587	u8_t ttl, u8_t tos, u8_t proto, struct netif netif, void ip_options,
donatien	0:b802fc31f1db	588	u16_t optlen)
donatien	0:b802fc31f1db	589	{
donatien	0:b802fc31f1db	590	#endif /* IP_OPTIONS_SEND */
donatien	0:b802fc31f1db	591	struct ip_hdr *iphdr;
donatien	1:3a7c15057192	592	ip_addr_t dest_addr;
donatien	1:3a7c15057192	593	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	594	u32_t chk_sum = 0;
donatien	1:3a7c15057192	595	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	596
donatien	0:b802fc31f1db	597	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
donatien	0:b802fc31f1db	598	gets altered as the packet is passed down the stack */
donatien	0:b802fc31f1db	599	LWIP_ASSERT("p->ref == 1", p->ref == 1);
donatien	0:b802fc31f1db	600
donatien	0:b802fc31f1db	601	snmp_inc_ipoutrequests();
donatien	0:b802fc31f1db	602
donatien	0:b802fc31f1db	603	/* Should the IP header be generated or is it already included in p? */
donatien	0:b802fc31f1db	604	if (dest != IP_HDRINCL) {
donatien	0:b802fc31f1db	605	u16_t ip_hlen = IP_HLEN;
donatien	0:b802fc31f1db	606	#if IP_OPTIONS_SEND
donatien	0:b802fc31f1db	607	u16_t optlen_aligned = 0;
donatien	0:b802fc31f1db	608	if (optlen != 0) {
donatien	1:3a7c15057192	609	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	610	int i;
donatien	1:3a7c15057192	611	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	612	/* round up to a multiple of 4 */
donatien	0:b802fc31f1db	613	optlen_aligned = ((optlen + 3) & ~3);
donatien	0:b802fc31f1db	614	ip_hlen += optlen_aligned;
donatien	0:b802fc31f1db	615	/* First write in the IP options */
donatien	0:b802fc31f1db	616	if (pbuf_header(p, optlen_aligned)) {
donatien	0:b802fc31f1db	617	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
donatien	0:b802fc31f1db	618	IP_STATS_INC(ip.err);
donatien	0:b802fc31f1db	619	snmp_inc_ipoutdiscards();
donatien	0:b802fc31f1db	620	return ERR_BUF;
donatien	0:b802fc31f1db	621	}
donatien	0:b802fc31f1db	622	MEMCPY(p->payload, ip_options, optlen);
donatien	0:b802fc31f1db	623	if (optlen < optlen_aligned) {
donatien	0:b802fc31f1db	624	/* zero the remaining bytes */
donatien	0:b802fc31f1db	625	memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
donatien	0:b802fc31f1db	626	}
donatien	1:3a7c15057192	627	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	628	for (i = 0; i < optlen_aligned; i += sizeof(u16_t)) {
donatien	1:3a7c15057192	629	chk_sum += ((u16_t*)p->payload)[i];
donatien	1:3a7c15057192	630	}
donatien	1:3a7c15057192	631	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	632	}
donatien	0:b802fc31f1db	633	#endif /* IP_OPTIONS_SEND */
donatien	0:b802fc31f1db	634	/* generate IP header */
donatien	0:b802fc31f1db	635	if (pbuf_header(p, IP_HLEN)) {
donatien	0:b802fc31f1db	636	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
donatien	0:b802fc31f1db	637
donatien	0:b802fc31f1db	638	IP_STATS_INC(ip.err);
donatien	0:b802fc31f1db	639	snmp_inc_ipoutdiscards();
donatien	0:b802fc31f1db	640	return ERR_BUF;
donatien	0:b802fc31f1db	641	}
donatien	0:b802fc31f1db	642
donatien	0:b802fc31f1db	643	iphdr = (struct ip_hdr *)p->payload;
donatien	0:b802fc31f1db	644	LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
donatien	0:b802fc31f1db	645	(p->len >= sizeof(struct ip_hdr)));
donatien	0:b802fc31f1db	646
donatien	0:b802fc31f1db	647	IPH_TTL_SET(iphdr, ttl);
donatien	0:b802fc31f1db	648	IPH_PROTO_SET(iphdr, proto);
donatien	1:3a7c15057192	649	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	650	chk_sum += LWIP_MAKE_U16(proto, ttl);
donatien	1:3a7c15057192	651	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	652
donatien	0:b802fc31f1db	653	/* dest cannot be NULL here */
donatien	0:b802fc31f1db	654	ip_addr_copy(iphdr->dest, *dest);
donatien	1:3a7c15057192	655	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	656	chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
donatien	1:3a7c15057192	657	chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
donatien	1:3a7c15057192	658	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	659
donatien	0:b802fc31f1db	660	IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
donatien	1:3a7c15057192	661	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	662	chk_sum += iphdr->_v_hl_tos;
donatien	1:3a7c15057192	663	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	664	IPH_LEN_SET(iphdr, htons(p->tot_len));
donatien	1:3a7c15057192	665	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	666	chk_sum += iphdr->_len;
donatien	1:3a7c15057192	667	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	668	IPH_OFFSET_SET(iphdr, 0);
donatien	0:b802fc31f1db	669	IPH_ID_SET(iphdr, htons(ip_id));
donatien	1:3a7c15057192	670	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	671	chk_sum += iphdr->_id;
donatien	1:3a7c15057192	672	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	673	++ip_id;
donatien	0:b802fc31f1db	674
donatien	0:b802fc31f1db	675	if (ip_addr_isany(src)) {
donatien	0:b802fc31f1db	676	ip_addr_copy(iphdr->src, netif->ip_addr);
donatien	0:b802fc31f1db	677	} else {
donatien	0:b802fc31f1db	678	/* src cannot be NULL here */
donatien	0:b802fc31f1db	679	ip_addr_copy(iphdr->src, *src);
donatien	0:b802fc31f1db	680	}
donatien	0:b802fc31f1db	681
donatien	1:3a7c15057192	682	#if CHECKSUM_GEN_IP_INLINE
donatien	1:3a7c15057192	683	chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
donatien	1:3a7c15057192	684	chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
donatien	1:3a7c15057192	685	chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
donatien	1:3a7c15057192	686	chk_sum = (chk_sum >> 16) + chk_sum;
donatien	1:3a7c15057192	687	chk_sum = ~chk_sum;
donatien	1:3a7c15057192	688	iphdr->_chksum = chk_sum; /* network order */
donatien	1:3a7c15057192	689	#else /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	690	IPH_CHKSUM_SET(iphdr, 0);
donatien	0:b802fc31f1db	691	#if CHECKSUM_GEN_IP
donatien	0:b802fc31f1db	692	IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
donatien	0:b802fc31f1db	693	#endif
donatien	1:3a7c15057192	694	#endif /* CHECKSUM_GEN_IP_INLINE */
donatien	0:b802fc31f1db	695	} else {
donatien	0:b802fc31f1db	696	/* IP header already included in p */
donatien	0:b802fc31f1db	697	iphdr = (struct ip_hdr *)p->payload;
donatien	1:3a7c15057192	698	ip_addr_copy(dest_addr, iphdr->dest);
donatien	1:3a7c15057192	699	dest = &dest_addr;
donatien	0:b802fc31f1db	700	}
donatien	0:b802fc31f1db	701
donatien	0:b802fc31f1db	702	IP_STATS_INC(ip.xmit);
donatien	0:b802fc31f1db	703
donatien	0:b802fc31f1db	704	LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
donatien	0:b802fc31f1db	705	ip_debug_print(p);
donatien	0:b802fc31f1db	706
donatien	0:b802fc31f1db	707	#if ENABLE_LOOPBACK
donatien	0:b802fc31f1db	708	if (ip_addr_cmp(dest, &netif->ip_addr)) {
donatien	0:b802fc31f1db	709	/* Packet to self, enqueue it for loopback */
donatien	0:b802fc31f1db	710	LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
donatien	0:b802fc31f1db	711	return netif_loop_output(netif, p, dest);
donatien	0:b802fc31f1db	712	}
donatien	1:3a7c15057192	713	#if LWIP_IGMP
donatien	1:3a7c15057192	714	if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
donatien	1:3a7c15057192	715	netif_loop_output(netif, p, dest);
donatien	1:3a7c15057192	716	}
donatien	1:3a7c15057192	717	#endif /* LWIP_IGMP */
donatien	0:b802fc31f1db	718	#endif /* ENABLE_LOOPBACK */
donatien	0:b802fc31f1db	719	#if IP_FRAG
donatien	0:b802fc31f1db	720	/* don't fragment if interface has mtu set to 0 [loopif] */
donatien	0:b802fc31f1db	721	if (netif->mtu && (p->tot_len > netif->mtu)) {
donatien	1:3a7c15057192	722	return ip_frag(p, netif, dest);
donatien	0:b802fc31f1db	723	}
donatien	1:3a7c15057192	724	#endif /* IP_FRAG */
donatien	0:b802fc31f1db	725
donatien	0:b802fc31f1db	726	LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
donatien	0:b802fc31f1db	727	return netif->output(netif, p, dest);
donatien	0:b802fc31f1db	728	}
donatien	0:b802fc31f1db	729
donatien	0:b802fc31f1db	730	/**
donatien	0:b802fc31f1db	731	* Simple interface to ip_output_if. It finds the outgoing network
donatien	0:b802fc31f1db	732	* interface and calls upon ip_output_if to do the actual work.
donatien	0:b802fc31f1db	733	*
donatien	0:b802fc31f1db	734	* @param p the packet to send (p->payload points to the data, e.g. next
donatien	0:b802fc31f1db	735	protocol header; if dest == IP_HDRINCL, p already includes an IP
donatien	0:b802fc31f1db	736	header and p->payload points to that IP header)
donatien	0:b802fc31f1db	737	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
donatien	0:b802fc31f1db	738	* IP address of the netif used to send is used as source address)
donatien	0:b802fc31f1db	739	* @param dest the destination IP address to send the packet to
donatien	0:b802fc31f1db	740	* @param ttl the TTL value to be set in the IP header
donatien	0:b802fc31f1db	741	* @param tos the TOS value to be set in the IP header
donatien	0:b802fc31f1db	742	* @param proto the PROTOCOL to be set in the IP header
donatien	0:b802fc31f1db	743	*
donatien	0:b802fc31f1db	744	* @return ERR_RTE if no route is found
donatien	0:b802fc31f1db	745	* see ip_output_if() for more return values
donatien	0:b802fc31f1db	746	*/
donatien	0:b802fc31f1db	747	err_t
donatien	0:b802fc31f1db	748	ip_output(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
donatien	0:b802fc31f1db	749	u8_t ttl, u8_t tos, u8_t proto)
donatien	0:b802fc31f1db	750	{
donatien	0:b802fc31f1db	751	struct netif *netif;
donatien	0:b802fc31f1db	752
donatien	0:b802fc31f1db	753	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
donatien	0:b802fc31f1db	754	gets altered as the packet is passed down the stack */
donatien	0:b802fc31f1db	755	LWIP_ASSERT("p->ref == 1", p->ref == 1);
donatien	0:b802fc31f1db	756
donatien	0:b802fc31f1db	757	if ((netif = ip_route(dest)) == NULL) {
donatien	0:b802fc31f1db	758	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
donatien	0:b802fc31f1db	759	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
donatien	0:b802fc31f1db	760	IP_STATS_INC(ip.rterr);
donatien	0:b802fc31f1db	761	return ERR_RTE;
donatien	0:b802fc31f1db	762	}
donatien	0:b802fc31f1db	763
donatien	0:b802fc31f1db	764	return ip_output_if(p, src, dest, ttl, tos, proto, netif);
donatien	0:b802fc31f1db	765	}
donatien	0:b802fc31f1db	766
donatien	0:b802fc31f1db	767	#if LWIP_NETIF_HWADDRHINT
donatien	0:b802fc31f1db	768	/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
donatien	0:b802fc31f1db	769	* before calling ip_output_if.
donatien	0:b802fc31f1db	770	*
donatien	0:b802fc31f1db	771	* @param p the packet to send (p->payload points to the data, e.g. next
donatien	0:b802fc31f1db	772	protocol header; if dest == IP_HDRINCL, p already includes an IP
donatien	0:b802fc31f1db	773	header and p->payload points to that IP header)
donatien	0:b802fc31f1db	774	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
donatien	0:b802fc31f1db	775	* IP address of the netif used to send is used as source address)
donatien	0:b802fc31f1db	776	* @param dest the destination IP address to send the packet to
donatien	0:b802fc31f1db	777	* @param ttl the TTL value to be set in the IP header
donatien	0:b802fc31f1db	778	* @param tos the TOS value to be set in the IP header
donatien	0:b802fc31f1db	779	* @param proto the PROTOCOL to be set in the IP header
donatien	0:b802fc31f1db	780	* @param addr_hint address hint pointer set to netif->addr_hint before
donatien	0:b802fc31f1db	781	* calling ip_output_if()
donatien	0:b802fc31f1db	782	*
donatien	0:b802fc31f1db	783	* @return ERR_RTE if no route is found
donatien	0:b802fc31f1db	784	* see ip_output_if() for more return values
donatien	0:b802fc31f1db	785	*/
donatien	0:b802fc31f1db	786	err_t
donatien	0:b802fc31f1db	787	ip_output_hinted(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
donatien	0:b802fc31f1db	788	u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
donatien	0:b802fc31f1db	789	{
donatien	0:b802fc31f1db	790	struct netif *netif;
donatien	0:b802fc31f1db	791	err_t err;
donatien	0:b802fc31f1db	792
donatien	0:b802fc31f1db	793	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
donatien	0:b802fc31f1db	794	gets altered as the packet is passed down the stack */
donatien	0:b802fc31f1db	795	LWIP_ASSERT("p->ref == 1", p->ref == 1);
donatien	0:b802fc31f1db	796
donatien	0:b802fc31f1db	797	if ((netif = ip_route(dest)) == NULL) {
donatien	0:b802fc31f1db	798	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
donatien	0:b802fc31f1db	799	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
donatien	0:b802fc31f1db	800	IP_STATS_INC(ip.rterr);
donatien	0:b802fc31f1db	801	return ERR_RTE;
donatien	0:b802fc31f1db	802	}
donatien	0:b802fc31f1db	803
donatien	0:b802fc31f1db	804	netif->addr_hint = addr_hint;
donatien	0:b802fc31f1db	805	err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
donatien	0:b802fc31f1db	806	netif->addr_hint = NULL;
donatien	0:b802fc31f1db	807
donatien	0:b802fc31f1db	808	return err;
donatien	0:b802fc31f1db	809	}
donatien	0:b802fc31f1db	810	#endif /* LWIP_NETIF_HWADDRHINT*/
donatien	0:b802fc31f1db	811
donatien	0:b802fc31f1db	812	#if IP_DEBUG
donatien	0:b802fc31f1db	813	/* Print an IP header by using LWIP_DEBUGF
donatien	0:b802fc31f1db	814	* @param p an IP packet, p->payload pointing to the IP header
donatien	0:b802fc31f1db	815	*/
donatien	0:b802fc31f1db	816	void
donatien	0:b802fc31f1db	817	ip_debug_print(struct pbuf *p)
donatien	0:b802fc31f1db	818	{
donatien	1:3a7c15057192	819	struct ip_hdr iphdr = (struct ip_hdr )p->payload;
donatien	0:b802fc31f1db	820	u8_t *payload;
donatien	0:b802fc31f1db	821
donatien	0:b802fc31f1db	822	payload = (u8_t *)iphdr + IP_HLEN;
donatien	0:b802fc31f1db	823
donatien	0:b802fc31f1db	824	LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
donatien	0:b802fc31f1db	825	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
donatien	0:b802fc31f1db	826	LWIP_DEBUGF(IP_DEBUG, ("\|%2"S16_F" \|%2"S16_F" \| 0x%02"X16_F" \| %5"U16_F" \| (v, hl, tos, len)\n",
donatien	0:b802fc31f1db	827	IPH_V(iphdr),
donatien	0:b802fc31f1db	828	IPH_HL(iphdr),
donatien	0:b802fc31f1db	829	IPH_TOS(iphdr),
donatien	0:b802fc31f1db	830	ntohs(IPH_LEN(iphdr))));
donatien	0:b802fc31f1db	831	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
donatien	0:b802fc31f1db	832	LWIP_DEBUGF(IP_DEBUG, ("\| %5"U16_F" \|%"U16_F"%"U16_F"%"U16_F"\| %4"U16_F" \| (id, flags, offset)\n",
donatien	0:b802fc31f1db	833	ntohs(IPH_ID(iphdr)),
donatien	0:b802fc31f1db	834	ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
donatien	0:b802fc31f1db	835	ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
donatien	0:b802fc31f1db	836	ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
donatien	0:b802fc31f1db	837	ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
donatien	0:b802fc31f1db	838	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
donatien	0:b802fc31f1db	839	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| 0x%04"X16_F" \| (ttl, proto, chksum)\n",
donatien	0:b802fc31f1db	840	IPH_TTL(iphdr),
donatien	0:b802fc31f1db	841	IPH_PROTO(iphdr),
donatien	0:b802fc31f1db	842	ntohs(IPH_CHKSUM(iphdr))));
donatien	0:b802fc31f1db	843	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
donatien	0:b802fc31f1db	844	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (src)\n",
donatien	0:b802fc31f1db	845	ip4_addr1_16(&iphdr->src),
donatien	0:b802fc31f1db	846	ip4_addr2_16(&iphdr->src),
donatien	0:b802fc31f1db	847	ip4_addr3_16(&iphdr->src),
donatien	0:b802fc31f1db	848	ip4_addr4_16(&iphdr->src)));
donatien	0:b802fc31f1db	849	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
donatien	0:b802fc31f1db	850	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (dest)\n",
donatien	0:b802fc31f1db	851	ip4_addr1_16(&iphdr->dest),
donatien	0:b802fc31f1db	852	ip4_addr2_16(&iphdr->dest),
donatien	0:b802fc31f1db	853	ip4_addr3_16(&iphdr->dest),
donatien	0:b802fc31f1db	854	ip4_addr4_16(&iphdr->dest)));
donatien	0:b802fc31f1db	855	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
donatien	0:b802fc31f1db	856	}
donatien	0:b802fc31f1db	857	#endif /* IP_DEBUG */

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Type:	Program
Created:	09 Jul 2010
Imports:	20
Forks:	0
Commits:	5
Dependents:	0
Dependencies:	0
Followers:	3

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lwip/core/ipv4/ip.c@1:3a7c15057192, 2010-08-06 (annotated)

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