AmpereMeter - Example self-announcing webserver which controls …

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Dirk-Willem van Gulik (NXP/mbed) / Mbed 2 deprecated AmpereMeter

Example self-announcing webserver which controls a servo through a smallHTML userinterface.

lwip/core/ipv4/ip.c@0:a259777c45a3, 2010-08-14 (annotated)

Committer:: dirkx
Date:: Sat Aug 14 15:56:01 2010 +0000
Revision:: 0:a259777c45a3

Who changed what in which revision?

User	Revision	Line number	New contents of line
dirkx	0:a259777c45a3	1	/**
dirkx	0:a259777c45a3	2	* @file
dirkx	0:a259777c45a3	3	* This is the IPv4 layer implementation for incoming and outgoing IP traffic.
dirkx	0:a259777c45a3	4	*
dirkx	0:a259777c45a3	5	* @see ip_frag.c
dirkx	0:a259777c45a3	6	*
dirkx	0:a259777c45a3	7	*/
dirkx	0:a259777c45a3	8
dirkx	0:a259777c45a3	9	/*
dirkx	0:a259777c45a3	10	* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
dirkx	0:a259777c45a3	11	* All rights reserved.
dirkx	0:a259777c45a3	12	*
dirkx	0:a259777c45a3	13	* Redistribution and use in source and binary forms, with or without modification,
dirkx	0:a259777c45a3	14	* are permitted provided that the following conditions are met:
dirkx	0:a259777c45a3	15	*
dirkx	0:a259777c45a3	16	* 1. Redistributions of source code must retain the above copyright notice,
dirkx	0:a259777c45a3	17	* this list of conditions and the following disclaimer.
dirkx	0:a259777c45a3	18	* 2. Redistributions in binary form must reproduce the above copyright notice,
dirkx	0:a259777c45a3	19	* this list of conditions and the following disclaimer in the documentation
dirkx	0:a259777c45a3	20	* and/or other materials provided with the distribution.
dirkx	0:a259777c45a3	21	* 3. The name of the author may not be used to endorse or promote products
dirkx	0:a259777c45a3	22	* derived from this software without specific prior written permission.
dirkx	0:a259777c45a3	23	*
dirkx	0:a259777c45a3	24	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
dirkx	0:a259777c45a3	25	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
dirkx	0:a259777c45a3	26	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
dirkx	0:a259777c45a3	27	* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
dirkx	0:a259777c45a3	28	* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
dirkx	0:a259777c45a3	29	* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
dirkx	0:a259777c45a3	30	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
dirkx	0:a259777c45a3	31	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
dirkx	0:a259777c45a3	32	* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
dirkx	0:a259777c45a3	33	* OF SUCH DAMAGE.
dirkx	0:a259777c45a3	34	*
dirkx	0:a259777c45a3	35	* This file is part of the lwIP TCP/IP stack.
dirkx	0:a259777c45a3	36	*
dirkx	0:a259777c45a3	37	* Author: Adam Dunkels <adam@sics.se>
dirkx	0:a259777c45a3	38	*
dirkx	0:a259777c45a3	39	*/
dirkx	0:a259777c45a3	40
dirkx	0:a259777c45a3	41	#include "lwip/opt.h"
dirkx	0:a259777c45a3	42	#include "lwip/ip.h"
dirkx	0:a259777c45a3	43	#include "lwip/def.h"
dirkx	0:a259777c45a3	44	#include "lwip/mem.h"
dirkx	0:a259777c45a3	45	#include "lwip/ip_frag.h"
dirkx	0:a259777c45a3	46	#include "lwip/inet_chksum.h"
dirkx	0:a259777c45a3	47	#include "lwip/netif.h"
dirkx	0:a259777c45a3	48	#include "lwip/icmp.h"
dirkx	0:a259777c45a3	49	#include "lwip/igmp.h"
dirkx	0:a259777c45a3	50	#include "lwip/raw.h"
dirkx	0:a259777c45a3	51	#include "lwip/udp.h"
dirkx	0:a259777c45a3	52	#include "lwip/tcp_impl.h"
dirkx	0:a259777c45a3	53	#include "lwip/snmp.h"
dirkx	0:a259777c45a3	54	#include "lwip/dhcp.h"
dirkx	0:a259777c45a3	55	#include "lwip/autoip.h"
dirkx	0:a259777c45a3	56	#include "lwip/stats.h"
dirkx	0:a259777c45a3	57	#include "arch/perf.h"
dirkx	0:a259777c45a3	58
dirkx	0:a259777c45a3	59	#include <string.h>
dirkx	0:a259777c45a3	60
dirkx	0:a259777c45a3	61	/**
dirkx	0:a259777c45a3	62	* The interface that provided the packet for the current callback
dirkx	0:a259777c45a3	63	* invocation.
dirkx	0:a259777c45a3	64	*/
dirkx	0:a259777c45a3	65	struct netif *current_netif;
dirkx	0:a259777c45a3	66
dirkx	0:a259777c45a3	67	/**
dirkx	0:a259777c45a3	68	* Header of the input packet currently being processed.
dirkx	0:a259777c45a3	69	*/
dirkx	0:a259777c45a3	70	const struct ip_hdr *current_header;
dirkx	0:a259777c45a3	71
dirkx	0:a259777c45a3	72	/**
dirkx	0:a259777c45a3	73	* Finds the appropriate network interface for a given IP address. It
dirkx	0:a259777c45a3	74	* searches the list of network interfaces linearly. A match is found
dirkx	0:a259777c45a3	75	* if the masked IP address of the network interface equals the masked
dirkx	0:a259777c45a3	76	* IP address given to the function.
dirkx	0:a259777c45a3	77	*
dirkx	0:a259777c45a3	78	* @param dest the destination IP address for which to find the route
dirkx	0:a259777c45a3	79	* @return the netif on which to send to reach dest
dirkx	0:a259777c45a3	80	*/
dirkx	0:a259777c45a3	81	struct netif *
dirkx	0:a259777c45a3	82	ip_route(ip_addr_t *dest)
dirkx	0:a259777c45a3	83	{
dirkx	0:a259777c45a3	84	struct netif *netif;
dirkx	0:a259777c45a3	85
dirkx	0:a259777c45a3	86	/* iterate through netifs */
dirkx	0:a259777c45a3	87	for(netif = netif_list; netif != NULL; netif = netif->next) {
dirkx	0:a259777c45a3	88	/* network mask matches? */
dirkx	0:a259777c45a3	89	if (netif_is_up(netif)) {
dirkx	0:a259777c45a3	90	if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
dirkx	0:a259777c45a3	91	/* return netif on which to forward IP packet */
dirkx	0:a259777c45a3	92	return netif;
dirkx	0:a259777c45a3	93	}
dirkx	0:a259777c45a3	94	}
dirkx	0:a259777c45a3	95	}
dirkx	0:a259777c45a3	96	if ((netif_default == NULL) \|\| (!netif_is_up(netif_default))) {
dirkx	0:a259777c45a3	97	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
dirkx	0:a259777c45a3	98	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
dirkx	0:a259777c45a3	99	IP_STATS_INC(ip.rterr);
dirkx	0:a259777c45a3	100	snmp_inc_ipoutnoroutes();
dirkx	0:a259777c45a3	101	return NULL;
dirkx	0:a259777c45a3	102	}
dirkx	0:a259777c45a3	103	/* no matching netif found, use default netif */
dirkx	0:a259777c45a3	104	return netif_default;
dirkx	0:a259777c45a3	105	}
dirkx	0:a259777c45a3	106
dirkx	0:a259777c45a3	107	#if IP_FORWARD
dirkx	0:a259777c45a3	108	/**
dirkx	0:a259777c45a3	109	* Forwards an IP packet. It finds an appropriate route for the
dirkx	0:a259777c45a3	110	* packet, decrements the TTL value of the packet, adjusts the
dirkx	0:a259777c45a3	111	* checksum and outputs the packet on the appropriate interface.
dirkx	0:a259777c45a3	112	*
dirkx	0:a259777c45a3	113	* @param p the packet to forward (p->payload points to IP header)
dirkx	0:a259777c45a3	114	* @param iphdr the IP header of the input packet
dirkx	0:a259777c45a3	115	* @param inp the netif on which this packet was received
dirkx	0:a259777c45a3	116	* @return the netif on which the packet was sent (NULL if it wasn't sent)
dirkx	0:a259777c45a3	117	*/
dirkx	0:a259777c45a3	118	static struct netif *
dirkx	0:a259777c45a3	119	ip_forward(struct pbuf p, struct ip_hdr iphdr, struct netif *inp)
dirkx	0:a259777c45a3	120	{
dirkx	0:a259777c45a3	121	struct netif *netif;
dirkx	0:a259777c45a3	122	ip_addr_t dest;
dirkx	0:a259777c45a3	123
dirkx	0:a259777c45a3	124	PERF_START;
dirkx	0:a259777c45a3	125	dest = iphdr->dest;
dirkx	0:a259777c45a3	126
dirkx	0:a259777c45a3	127	/* RFC3927 2.7: do not forward link-local addresses */
dirkx	0:a259777c45a3	128	if (ip_addr_islinklocal(&dest)) {
dirkx	0:a259777c45a3	129	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
dirkx	0:a259777c45a3	130	ip4_addr1_16(&dest), ip4_addr2_16(&dest), ip4_addr3_16(&dest), ip4_addr4_16(&dest)));
dirkx	0:a259777c45a3	131	snmp_inc_ipoutnoroutes();
dirkx	0:a259777c45a3	132	return (struct netif *)NULL;
dirkx	0:a259777c45a3	133	}
dirkx	0:a259777c45a3	134
dirkx	0:a259777c45a3	135	/* Find network interface where to forward this IP packet to. */
dirkx	0:a259777c45a3	136	netif = ip_route(&dest);
dirkx	0:a259777c45a3	137	if (netif == NULL) {
dirkx	0:a259777c45a3	138	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
dirkx	0:a259777c45a3	139	ip4_addr1_16(&dest), ip4_addr2_16(&dest), ip4_addr3_16(&dest), ip4_addr4_16(&dest)));
dirkx	0:a259777c45a3	140	snmp_inc_ipoutnoroutes();
dirkx	0:a259777c45a3	141	return (struct netif *)NULL;
dirkx	0:a259777c45a3	142	}
dirkx	0:a259777c45a3	143	/* Do not forward packets onto the same network interface on which
dirkx	0:a259777c45a3	144	* they arrived. */
dirkx	0:a259777c45a3	145	if (netif == inp) {
dirkx	0:a259777c45a3	146	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
dirkx	0:a259777c45a3	147	snmp_inc_ipoutnoroutes();
dirkx	0:a259777c45a3	148	return (struct netif *)NULL;
dirkx	0:a259777c45a3	149	}
dirkx	0:a259777c45a3	150
dirkx	0:a259777c45a3	151	/* decrement TTL */
dirkx	0:a259777c45a3	152	IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
dirkx	0:a259777c45a3	153	/* send ICMP if TTL == 0 */
dirkx	0:a259777c45a3	154	if (IPH_TTL(iphdr) == 0) {
dirkx	0:a259777c45a3	155	snmp_inc_ipinhdrerrors();
dirkx	0:a259777c45a3	156	#if LWIP_ICMP
dirkx	0:a259777c45a3	157	/* Don't send ICMP messages in response to ICMP messages */
dirkx	0:a259777c45a3	158	if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
dirkx	0:a259777c45a3	159	icmp_time_exceeded(p, ICMP_TE_TTL);
dirkx	0:a259777c45a3	160	}
dirkx	0:a259777c45a3	161	#endif /* LWIP_ICMP */
dirkx	0:a259777c45a3	162	return (struct netif *)NULL;
dirkx	0:a259777c45a3	163	}
dirkx	0:a259777c45a3	164
dirkx	0:a259777c45a3	165	/* Incrementally update the IP checksum. */
dirkx	0:a259777c45a3	166	if (IPH_CHKSUM(iphdr) >= htons(0xffff - 0x100)) {
dirkx	0:a259777c45a3	167	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100) + 1);
dirkx	0:a259777c45a3	168	} else {
dirkx	0:a259777c45a3	169	IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100));
dirkx	0:a259777c45a3	170	}
dirkx	0:a259777c45a3	171
dirkx	0:a259777c45a3	172	LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
dirkx	0:a259777c45a3	173	ip4_addr1_16(&dest), ip4_addr2_16(&dest), ip4_addr3_16(&dest), ip4_addr4_16(&dest)));
dirkx	0:a259777c45a3	174
dirkx	0:a259777c45a3	175	IP_STATS_INC(ip.fw);
dirkx	0:a259777c45a3	176	IP_STATS_INC(ip.xmit);
dirkx	0:a259777c45a3	177	snmp_inc_ipforwdatagrams();
dirkx	0:a259777c45a3	178
dirkx	0:a259777c45a3	179	PERF_STOP("ip_forward");
dirkx	0:a259777c45a3	180	/* transmit pbuf on chosen interface */
dirkx	0:a259777c45a3	181	netif->output(netif, p, &dest);
dirkx	0:a259777c45a3	182	return netif;
dirkx	0:a259777c45a3	183	}
dirkx	0:a259777c45a3	184	#endif /* IP_FORWARD */
dirkx	0:a259777c45a3	185
dirkx	0:a259777c45a3	186	/**
dirkx	0:a259777c45a3	187	* This function is called by the network interface device driver when
dirkx	0:a259777c45a3	188	* an IP packet is received. The function does the basic checks of the
dirkx	0:a259777c45a3	189	* IP header such as packet size being at least larger than the header
dirkx	0:a259777c45a3	190	* size etc. If the packet was not destined for us, the packet is
dirkx	0:a259777c45a3	191	* forwarded (using ip_forward). The IP checksum is always checked.
dirkx	0:a259777c45a3	192	*
dirkx	0:a259777c45a3	193	* Finally, the packet is sent to the upper layer protocol input function.
dirkx	0:a259777c45a3	194	*
dirkx	0:a259777c45a3	195	* @param p the received IP packet (p->payload points to IP header)
dirkx	0:a259777c45a3	196	* @param inp the netif on which this packet was received
dirkx	0:a259777c45a3	197	* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
dirkx	0:a259777c45a3	198	* processed, but currently always returns ERR_OK)
dirkx	0:a259777c45a3	199	*/
dirkx	0:a259777c45a3	200	err_t
dirkx	0:a259777c45a3	201	ip_input(struct pbuf p, struct netif inp)
dirkx	0:a259777c45a3	202	{
dirkx	0:a259777c45a3	203	struct ip_hdr *iphdr;
dirkx	0:a259777c45a3	204	struct netif *netif;
dirkx	0:a259777c45a3	205	u16_t iphdr_hlen;
dirkx	0:a259777c45a3	206	u16_t iphdr_len;
dirkx	0:a259777c45a3	207	#if LWIP_DHCP
dirkx	0:a259777c45a3	208	int check_ip_src=1;
dirkx	0:a259777c45a3	209	#endif /* LWIP_DHCP */
dirkx	0:a259777c45a3	210
dirkx	0:a259777c45a3	211	IP_STATS_INC(ip.recv);
dirkx	0:a259777c45a3	212	snmp_inc_ipinreceives();
dirkx	0:a259777c45a3	213
dirkx	0:a259777c45a3	214	/* identify the IP header */
dirkx	0:a259777c45a3	215	iphdr = (struct ip_hdr *)p->payload;
dirkx	0:a259777c45a3	216	if (IPH_V(iphdr) != 4) {
dirkx	0:a259777c45a3	217	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
dirkx	0:a259777c45a3	218	ip_debug_print(p);
dirkx	0:a259777c45a3	219	pbuf_free(p);
dirkx	0:a259777c45a3	220	IP_STATS_INC(ip.err);
dirkx	0:a259777c45a3	221	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	222	snmp_inc_ipinhdrerrors();
dirkx	0:a259777c45a3	223	return ERR_OK;
dirkx	0:a259777c45a3	224	}
dirkx	0:a259777c45a3	225
dirkx	0:a259777c45a3	226	/* obtain IP header length in number of 32-bit words */
dirkx	0:a259777c45a3	227	iphdr_hlen = IPH_HL(iphdr);
dirkx	0:a259777c45a3	228	/* calculate IP header length in bytes */
dirkx	0:a259777c45a3	229	iphdr_hlen *= 4;
dirkx	0:a259777c45a3	230	/* obtain ip length in bytes */
dirkx	0:a259777c45a3	231	iphdr_len = ntohs(IPH_LEN(iphdr));
dirkx	0:a259777c45a3	232
dirkx	0:a259777c45a3	233	/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
dirkx	0:a259777c45a3	234	if ((iphdr_hlen > p->len) \|\| (iphdr_len > p->tot_len)) {
dirkx	0:a259777c45a3	235	if (iphdr_hlen > p->len) {
dirkx	0:a259777c45a3	236	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
dirkx	0:a259777c45a3	237	("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
dirkx	0:a259777c45a3	238	iphdr_hlen, p->len));
dirkx	0:a259777c45a3	239	}
dirkx	0:a259777c45a3	240	if (iphdr_len > p->tot_len) {
dirkx	0:a259777c45a3	241	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
dirkx	0:a259777c45a3	242	("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
dirkx	0:a259777c45a3	243	iphdr_len, p->tot_len));
dirkx	0:a259777c45a3	244	}
dirkx	0:a259777c45a3	245	/* free (drop) packet pbufs */
dirkx	0:a259777c45a3	246	pbuf_free(p);
dirkx	0:a259777c45a3	247	IP_STATS_INC(ip.lenerr);
dirkx	0:a259777c45a3	248	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	249	snmp_inc_ipindiscards();
dirkx	0:a259777c45a3	250	return ERR_OK;
dirkx	0:a259777c45a3	251	}
dirkx	0:a259777c45a3	252
dirkx	0:a259777c45a3	253	/* verify checksum */
dirkx	0:a259777c45a3	254	#if CHECKSUM_CHECK_IP
dirkx	0:a259777c45a3	255	if (inet_chksum(iphdr, iphdr_hlen) != 0) {
dirkx	0:a259777c45a3	256
dirkx	0:a259777c45a3	257	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS,
dirkx	0:a259777c45a3	258	("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
dirkx	0:a259777c45a3	259	ip_debug_print(p);
dirkx	0:a259777c45a3	260	pbuf_free(p);
dirkx	0:a259777c45a3	261	IP_STATS_INC(ip.chkerr);
dirkx	0:a259777c45a3	262	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	263	snmp_inc_ipinhdrerrors();
dirkx	0:a259777c45a3	264	return ERR_OK;
dirkx	0:a259777c45a3	265	}
dirkx	0:a259777c45a3	266	#endif
dirkx	0:a259777c45a3	267
dirkx	0:a259777c45a3	268	/* Trim pbuf. This should have been done at the netif layer,
dirkx	0:a259777c45a3	269	* but we'll do it anyway just to be sure that its done. */
dirkx	0:a259777c45a3	270	pbuf_realloc(p, iphdr_len);
dirkx	0:a259777c45a3	271
dirkx	0:a259777c45a3	272	/* match packet against an interface, i.e. is this packet for us? */
dirkx	0:a259777c45a3	273	#if LWIP_IGMP
dirkx	0:a259777c45a3	274	if (ip_addr_ismulticast(&(iphdr->dest))) {
dirkx	0:a259777c45a3	275	if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &(iphdr->dest)))) {
dirkx	0:a259777c45a3	276	netif = inp;
dirkx	0:a259777c45a3	277	} else {
dirkx	0:a259777c45a3	278	netif = NULL;
dirkx	0:a259777c45a3	279	}
dirkx	0:a259777c45a3	280	} else
dirkx	0:a259777c45a3	281	#endif /* LWIP_IGMP */
dirkx	0:a259777c45a3	282	{
dirkx	0:a259777c45a3	283	/* start trying with inp. if that's not acceptable, start walking the
dirkx	0:a259777c45a3	284	list of configured netifs.
dirkx	0:a259777c45a3	285	'first' is used as a boolean to mark whether we started walking the list */
dirkx	0:a259777c45a3	286	int first = 1;
dirkx	0:a259777c45a3	287	netif = inp;
dirkx	0:a259777c45a3	288	do {
dirkx	0:a259777c45a3	289	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",
dirkx	0:a259777c45a3	290	ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
dirkx	0:a259777c45a3	291	ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
dirkx	0:a259777c45a3	292	ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
dirkx	0:a259777c45a3	293	ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
dirkx	0:a259777c45a3	294
dirkx	0:a259777c45a3	295	/* interface is up and configured? */
dirkx	0:a259777c45a3	296	if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
dirkx	0:a259777c45a3	297	/* unicast to this interface address? */
dirkx	0:a259777c45a3	298	if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr))
dirkx	0:a259777c45a3	299	/* or broadcast on this interface network address? */
dirkx	0:a259777c45a3	300	\|\| ip_addr_isbroadcast(&(iphdr->dest), netif)
dirkx	0:a259777c45a3	301	#if 0
dirkx	0:a259777c45a3	302	/* or is this to our multicast interface? DIRKX */
dirkx	0:a259777c45a3	303	\|\| ip_addr_ismulticast(&(iphdr->dest))
dirkx	0:a259777c45a3	304	#endif
dirkx	0:a259777c45a3	305	) {
dirkx	0:a259777c45a3	306	LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
dirkx	0:a259777c45a3	307	netif->name[0], netif->name[1]));
dirkx	0:a259777c45a3	308	/* break out of for loop */
dirkx	0:a259777c45a3	309	break;
dirkx	0:a259777c45a3	310	}
dirkx	0:a259777c45a3	311	#if LWIP_AUTOIP
dirkx	0:a259777c45a3	312	/* connections to link-local addresses must persist after changing
dirkx	0:a259777c45a3	313	the netif's address (RFC3927 ch. 1.9) */
dirkx	0:a259777c45a3	314	if ((netif->autoip != NULL) &&
dirkx	0:a259777c45a3	315	ip_addr_cmp(&(iphdr->dest), &(netif->autoip->llipaddr))) {
dirkx	0:a259777c45a3	316	LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
dirkx	0:a259777c45a3	317	netif->name[0], netif->name[1]));
dirkx	0:a259777c45a3	318	/* break out of for loop */
dirkx	0:a259777c45a3	319	break;
dirkx	0:a259777c45a3	320	}
dirkx	0:a259777c45a3	321	#endif /* LWIP_AUTOIP */
dirkx	0:a259777c45a3	322	}
dirkx	0:a259777c45a3	323	if (first) {
dirkx	0:a259777c45a3	324	first = 0;
dirkx	0:a259777c45a3	325	netif = netif_list;
dirkx	0:a259777c45a3	326	} else {
dirkx	0:a259777c45a3	327	netif = netif->next;
dirkx	0:a259777c45a3	328	}
dirkx	0:a259777c45a3	329	if (netif == inp) {
dirkx	0:a259777c45a3	330	netif = netif->next;
dirkx	0:a259777c45a3	331	}
dirkx	0:a259777c45a3	332	} while(netif != NULL);
dirkx	0:a259777c45a3	333	}
dirkx	0:a259777c45a3	334
dirkx	0:a259777c45a3	335	#if LWIP_DHCP
dirkx	0:a259777c45a3	336	/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
dirkx	0:a259777c45a3	337	* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
dirkx	0:a259777c45a3	338	* According to RFC 1542 section 3.1.1, referred by RFC 2131).
dirkx	0:a259777c45a3	339	*/
dirkx	0:a259777c45a3	340	if (netif == NULL) {
dirkx	0:a259777c45a3	341	/* remote port is DHCP server? */
dirkx	0:a259777c45a3	342	if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
dirkx	0:a259777c45a3	343	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
dirkx	0:a259777c45a3	344	ntohs(((struct udp_hdr )((u8_t )iphdr + iphdr_hlen))->dest)));
dirkx	0:a259777c45a3	345	if (ntohs(((struct udp_hdr )((u8_t )iphdr + iphdr_hlen))->dest) == DHCP_CLIENT_PORT) {
dirkx	0:a259777c45a3	346	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
dirkx	0:a259777c45a3	347	netif = inp;
dirkx	0:a259777c45a3	348	check_ip_src = 0;
dirkx	0:a259777c45a3	349	}
dirkx	0:a259777c45a3	350	}
dirkx	0:a259777c45a3	351	}
dirkx	0:a259777c45a3	352	#endif /* LWIP_DHCP */
dirkx	0:a259777c45a3	353
dirkx	0:a259777c45a3	354	/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
dirkx	0:a259777c45a3	355	#if LWIP_DHCP
dirkx	0:a259777c45a3	356	/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
dirkx	0:a259777c45a3	357	if (check_ip_src && !ip_addr_isany(&iphdr->src))
dirkx	0:a259777c45a3	358	#endif /* LWIP_DHCP */
dirkx	0:a259777c45a3	359	{ if ((ip_addr_isbroadcast(&(iphdr->src), inp)) \|\|
dirkx	0:a259777c45a3	360	(ip_addr_ismulticast(&(iphdr->src)))) {
dirkx	0:a259777c45a3	361	/* packet source is not valid */
dirkx	0:a259777c45a3	362	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE \| LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
dirkx	0:a259777c45a3	363	/* free (drop) packet pbufs */
dirkx	0:a259777c45a3	364	pbuf_free(p);
dirkx	0:a259777c45a3	365	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	366	snmp_inc_ipinaddrerrors();
dirkx	0:a259777c45a3	367	snmp_inc_ipindiscards();
dirkx	0:a259777c45a3	368	return ERR_OK;
dirkx	0:a259777c45a3	369	}
dirkx	0:a259777c45a3	370	}
dirkx	0:a259777c45a3	371
dirkx	0:a259777c45a3	372	/* packet not for us? */
dirkx	0:a259777c45a3	373	if (netif == NULL) {
dirkx	0:a259777c45a3	374	/* packet not for us, route or discard */
dirkx	0:a259777c45a3	375	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
dirkx	0:a259777c45a3	376	#if IP_FORWARD
dirkx	0:a259777c45a3	377	/* non-broadcast packet? */
dirkx	0:a259777c45a3	378	if (!ip_addr_isbroadcast(&(iphdr->dest), inp)) {
dirkx	0:a259777c45a3	379	/* try to forward IP packet on (other) interfaces */
dirkx	0:a259777c45a3	380	ip_forward(p, iphdr, inp);
dirkx	0:a259777c45a3	381	} else
dirkx	0:a259777c45a3	382	#endif /* IP_FORWARD */
dirkx	0:a259777c45a3	383	{
dirkx	0:a259777c45a3	384	snmp_inc_ipinaddrerrors();
dirkx	0:a259777c45a3	385	snmp_inc_ipindiscards();
dirkx	0:a259777c45a3	386	}
dirkx	0:a259777c45a3	387	pbuf_free(p);
dirkx	0:a259777c45a3	388	return ERR_OK;
dirkx	0:a259777c45a3	389	}
dirkx	0:a259777c45a3	390	/* packet consists of multiple fragments? */
dirkx	0:a259777c45a3	391	if ((IPH_OFFSET(iphdr) & htons(IP_OFFMASK \| IP_MF)) != 0) {
dirkx	0:a259777c45a3	392	#if IP_REASSEMBLY /* packet fragment reassembly code present? */
dirkx	0:a259777c45a3	393	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",
dirkx	0:a259777c45a3	394	ntohs(IPH_ID(iphdr)), p->tot_len, ntohs(IPH_LEN(iphdr)), !!(IPH_OFFSET(iphdr) & htons(IP_MF)), (ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK)*8));
dirkx	0:a259777c45a3	395	/* reassemble the packet*/
dirkx	0:a259777c45a3	396	p = ip_reass(p);
dirkx	0:a259777c45a3	397	/* packet not fully reassembled yet? */
dirkx	0:a259777c45a3	398	if (p == NULL) {
dirkx	0:a259777c45a3	399	return ERR_OK;
dirkx	0:a259777c45a3	400	}
dirkx	0:a259777c45a3	401	iphdr = (struct ip_hdr *)p->payload;
dirkx	0:a259777c45a3	402	#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
dirkx	0:a259777c45a3	403	pbuf_free(p);
dirkx	0:a259777c45a3	404	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
dirkx	0:a259777c45a3	405	ntohs(IPH_OFFSET(iphdr))));
dirkx	0:a259777c45a3	406	IP_STATS_INC(ip.opterr);
dirkx	0:a259777c45a3	407	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	408	/* unsupported protocol feature */
dirkx	0:a259777c45a3	409	snmp_inc_ipinunknownprotos();
dirkx	0:a259777c45a3	410	return ERR_OK;
dirkx	0:a259777c45a3	411	#endif /* IP_REASSEMBLY */
dirkx	0:a259777c45a3	412	}
dirkx	0:a259777c45a3	413
dirkx	0:a259777c45a3	414	#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
dirkx	0:a259777c45a3	415
dirkx	0:a259777c45a3	416	#if LWIP_IGMP
dirkx	0:a259777c45a3	417	/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
dirkx	0:a259777c45a3	418	if((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
dirkx	0:a259777c45a3	419	#else
dirkx	0:a259777c45a3	420	if (iphdr_hlen > IP_HLEN) {
dirkx	0:a259777c45a3	421	#endif /* LWIP_IGMP */
dirkx	0:a259777c45a3	422	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
dirkx	0:a259777c45a3	423	pbuf_free(p);
dirkx	0:a259777c45a3	424	IP_STATS_INC(ip.opterr);
dirkx	0:a259777c45a3	425	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	426	/* unsupported protocol feature */
dirkx	0:a259777c45a3	427	snmp_inc_ipinunknownprotos();
dirkx	0:a259777c45a3	428	return ERR_OK;
dirkx	0:a259777c45a3	429	}
dirkx	0:a259777c45a3	430	#endif /* IP_OPTIONS_ALLOWED == 0 */
dirkx	0:a259777c45a3	431
dirkx	0:a259777c45a3	432	/* send to upper layers */
dirkx	0:a259777c45a3	433	LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
dirkx	0:a259777c45a3	434	ip_debug_print(p);
dirkx	0:a259777c45a3	435	LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
dirkx	0:a259777c45a3	436
dirkx	0:a259777c45a3	437	current_netif = inp;
dirkx	0:a259777c45a3	438	current_header = iphdr;
dirkx	0:a259777c45a3	439
dirkx	0:a259777c45a3	440	#if LWIP_RAW
dirkx	0:a259777c45a3	441	/* raw input did not eat the packet? */
dirkx	0:a259777c45a3	442	if (raw_input(p, inp) == 0)
dirkx	0:a259777c45a3	443	#endif /* LWIP_RAW */
dirkx	0:a259777c45a3	444	{
dirkx	0:a259777c45a3	445
dirkx	0:a259777c45a3	446	switch (IPH_PROTO(iphdr)) {
dirkx	0:a259777c45a3	447	#if LWIP_UDP
dirkx	0:a259777c45a3	448	case IP_PROTO_UDP:
dirkx	0:a259777c45a3	449	#if LWIP_UDPLITE
dirkx	0:a259777c45a3	450	case IP_PROTO_UDPLITE:
dirkx	0:a259777c45a3	451	#endif /* LWIP_UDPLITE */
dirkx	0:a259777c45a3	452	snmp_inc_ipindelivers();
dirkx	0:a259777c45a3	453	udp_input(p, inp);
dirkx	0:a259777c45a3	454	break;
dirkx	0:a259777c45a3	455	#endif /* LWIP_UDP */
dirkx	0:a259777c45a3	456	#if LWIP_TCP
dirkx	0:a259777c45a3	457	case IP_PROTO_TCP:
dirkx	0:a259777c45a3	458	snmp_inc_ipindelivers();
dirkx	0:a259777c45a3	459	tcp_input(p, inp);
dirkx	0:a259777c45a3	460	break;
dirkx	0:a259777c45a3	461	#endif /* LWIP_TCP */
dirkx	0:a259777c45a3	462	#if LWIP_ICMP
dirkx	0:a259777c45a3	463	case IP_PROTO_ICMP:
dirkx	0:a259777c45a3	464	snmp_inc_ipindelivers();
dirkx	0:a259777c45a3	465	icmp_input(p, inp);
dirkx	0:a259777c45a3	466	break;
dirkx	0:a259777c45a3	467	#endif /* LWIP_ICMP */
dirkx	0:a259777c45a3	468	#if LWIP_IGMP
dirkx	0:a259777c45a3	469	case IP_PROTO_IGMP:
dirkx	0:a259777c45a3	470	igmp_input(p,inp,&(iphdr->dest));
dirkx	0:a259777c45a3	471	break;
dirkx	0:a259777c45a3	472	#endif /* LWIP_IGMP */
dirkx	0:a259777c45a3	473	default:
dirkx	0:a259777c45a3	474	#if LWIP_ICMP
dirkx	0:a259777c45a3	475	/* send ICMP destination protocol unreachable unless is was a broadcast */
dirkx	0:a259777c45a3	476	if (!ip_addr_isbroadcast(&(iphdr->dest), inp) &&
dirkx	0:a259777c45a3	477	!ip_addr_ismulticast(&(iphdr->dest))) {
dirkx	0:a259777c45a3	478	p->payload = iphdr;
dirkx	0:a259777c45a3	479	icmp_dest_unreach(p, ICMP_DUR_PROTO);
dirkx	0:a259777c45a3	480	}
dirkx	0:a259777c45a3	481	#endif /* LWIP_ICMP */
dirkx	0:a259777c45a3	482	pbuf_free(p);
dirkx	0:a259777c45a3	483
dirkx	0:a259777c45a3	484	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
dirkx	0:a259777c45a3	485
dirkx	0:a259777c45a3	486	IP_STATS_INC(ip.proterr);
dirkx	0:a259777c45a3	487	IP_STATS_INC(ip.drop);
dirkx	0:a259777c45a3	488	snmp_inc_ipinunknownprotos();
dirkx	0:a259777c45a3	489	}
dirkx	0:a259777c45a3	490	}
dirkx	0:a259777c45a3	491
dirkx	0:a259777c45a3	492	current_netif = NULL;
dirkx	0:a259777c45a3	493	current_header = NULL;
dirkx	0:a259777c45a3	494
dirkx	0:a259777c45a3	495	return ERR_OK;
dirkx	0:a259777c45a3	496	}
dirkx	0:a259777c45a3	497
dirkx	0:a259777c45a3	498	/**
dirkx	0:a259777c45a3	499	* Sends an IP packet on a network interface. This function constructs
dirkx	0:a259777c45a3	500	* the IP header and calculates the IP header checksum. If the source
dirkx	0:a259777c45a3	501	* IP address is NULL, the IP address of the outgoing network
dirkx	0:a259777c45a3	502	* interface is filled in as source address.
dirkx	0:a259777c45a3	503	* If the destination IP address is IP_HDRINCL, p is assumed to already
dirkx	0:a259777c45a3	504	* include an IP header and p->payload points to it instead of the data.
dirkx	0:a259777c45a3	505	*
dirkx	0:a259777c45a3	506	* @param p the packet to send (p->payload points to the data, e.g. next
dirkx	0:a259777c45a3	507	protocol header; if dest == IP_HDRINCL, p already includes an IP
dirkx	0:a259777c45a3	508	header and p->payload points to that IP header)
dirkx	0:a259777c45a3	509	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
dirkx	0:a259777c45a3	510	* IP address of the netif used to send is used as source address)
dirkx	0:a259777c45a3	511	* @param dest the destination IP address to send the packet to
dirkx	0:a259777c45a3	512	* @param ttl the TTL value to be set in the IP header
dirkx	0:a259777c45a3	513	* @param tos the TOS value to be set in the IP header
dirkx	0:a259777c45a3	514	* @param proto the PROTOCOL to be set in the IP header
dirkx	0:a259777c45a3	515	* @param netif the netif on which to send this packet
dirkx	0:a259777c45a3	516	* @return ERR_OK if the packet was sent OK
dirkx	0:a259777c45a3	517	* ERR_BUF if p doesn't have enough space for IP/LINK headers
dirkx	0:a259777c45a3	518	* returns errors returned by netif->output
dirkx	0:a259777c45a3	519	*
dirkx	0:a259777c45a3	520	* @note ip_id: RFC791 "some host may be able to simply use
dirkx	0:a259777c45a3	521	* unique identifiers independent of destination"
dirkx	0:a259777c45a3	522	*/
dirkx	0:a259777c45a3	523	err_t
dirkx	0:a259777c45a3	524	ip_output_if(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
dirkx	0:a259777c45a3	525	u8_t ttl, u8_t tos,
dirkx	0:a259777c45a3	526	u8_t proto, struct netif *netif)
dirkx	0:a259777c45a3	527	{
dirkx	0:a259777c45a3	528	#if IP_OPTIONS_SEND
dirkx	0:a259777c45a3	529	return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
dirkx	0:a259777c45a3	530	}
dirkx	0:a259777c45a3	531
dirkx	0:a259777c45a3	532	/**
dirkx	0:a259777c45a3	533	* Same as ip_output_if() but with the possibility to include IP options:
dirkx	0:a259777c45a3	534	*
dirkx	0:a259777c45a3	535	* @ param ip_options pointer to the IP options, copied into the IP header
dirkx	0:a259777c45a3	536	* @ param optlen length of ip_options
dirkx	0:a259777c45a3	537	*/
dirkx	0:a259777c45a3	538	err_t ip_output_if_opt(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
dirkx	0:a259777c45a3	539	u8_t ttl, u8_t tos, u8_t proto, struct netif netif, void ip_options,
dirkx	0:a259777c45a3	540	u16_t optlen)
dirkx	0:a259777c45a3	541	{
dirkx	0:a259777c45a3	542	#endif /* IP_OPTIONS_SEND */
dirkx	0:a259777c45a3	543	struct ip_hdr *iphdr;
dirkx	0:a259777c45a3	544	static u16_t ip_id = 0;
dirkx	0:a259777c45a3	545
dirkx	0:a259777c45a3	546	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
dirkx	0:a259777c45a3	547	gets altered as the packet is passed down the stack */
dirkx	0:a259777c45a3	548	LWIP_ASSERT("p->ref == 1", p->ref == 1);
dirkx	0:a259777c45a3	549
dirkx	0:a259777c45a3	550	snmp_inc_ipoutrequests();
dirkx	0:a259777c45a3	551
dirkx	0:a259777c45a3	552	/* Should the IP header be generated or is it already included in p? */
dirkx	0:a259777c45a3	553	if (dest != IP_HDRINCL) {
dirkx	0:a259777c45a3	554	u16_t ip_hlen = IP_HLEN;
dirkx	0:a259777c45a3	555	#if IP_OPTIONS_SEND
dirkx	0:a259777c45a3	556	u16_t optlen_aligned = 0;
dirkx	0:a259777c45a3	557	if (optlen != 0) {
dirkx	0:a259777c45a3	558	/* round up to a multiple of 4 */
dirkx	0:a259777c45a3	559	optlen_aligned = ((optlen + 3) & ~3);
dirkx	0:a259777c45a3	560	ip_hlen += optlen_aligned;
dirkx	0:a259777c45a3	561	/* First write in the IP options */
dirkx	0:a259777c45a3	562	if (pbuf_header(p, optlen_aligned)) {
dirkx	0:a259777c45a3	563	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
dirkx	0:a259777c45a3	564	IP_STATS_INC(ip.err);
dirkx	0:a259777c45a3	565	snmp_inc_ipoutdiscards();
dirkx	0:a259777c45a3	566	return ERR_BUF;
dirkx	0:a259777c45a3	567	}
dirkx	0:a259777c45a3	568	MEMCPY(p->payload, ip_options, optlen);
dirkx	0:a259777c45a3	569	if (optlen < optlen_aligned) {
dirkx	0:a259777c45a3	570	/* zero the remaining bytes */
dirkx	0:a259777c45a3	571	memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
dirkx	0:a259777c45a3	572	}
dirkx	0:a259777c45a3	573	}
dirkx	0:a259777c45a3	574	#endif /* IP_OPTIONS_SEND */
dirkx	0:a259777c45a3	575	/* generate IP header */
dirkx	0:a259777c45a3	576	if (pbuf_header(p, IP_HLEN)) {
dirkx	0:a259777c45a3	577	LWIP_DEBUGF(IP_DEBUG \| LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
dirkx	0:a259777c45a3	578
dirkx	0:a259777c45a3	579	IP_STATS_INC(ip.err);
dirkx	0:a259777c45a3	580	snmp_inc_ipoutdiscards();
dirkx	0:a259777c45a3	581	return ERR_BUF;
dirkx	0:a259777c45a3	582	}
dirkx	0:a259777c45a3	583
dirkx	0:a259777c45a3	584	iphdr = (struct ip_hdr *)p->payload;
dirkx	0:a259777c45a3	585	LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
dirkx	0:a259777c45a3	586	(p->len >= sizeof(struct ip_hdr)));
dirkx	0:a259777c45a3	587
dirkx	0:a259777c45a3	588	IPH_TTL_SET(iphdr, ttl);
dirkx	0:a259777c45a3	589	IPH_PROTO_SET(iphdr, proto);
dirkx	0:a259777c45a3	590
dirkx	0:a259777c45a3	591	/* dest cannot be NULL here */
dirkx	0:a259777c45a3	592	ip_addr_copy(iphdr->dest, *dest);
dirkx	0:a259777c45a3	593
dirkx	0:a259777c45a3	594	IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
dirkx	0:a259777c45a3	595	IPH_LEN_SET(iphdr, htons(p->tot_len));
dirkx	0:a259777c45a3	596	IPH_OFFSET_SET(iphdr, 0);
dirkx	0:a259777c45a3	597	IPH_ID_SET(iphdr, htons(ip_id));
dirkx	0:a259777c45a3	598	++ip_id;
dirkx	0:a259777c45a3	599
dirkx	0:a259777c45a3	600	if (ip_addr_isany(src)) {
dirkx	0:a259777c45a3	601	ip_addr_copy(iphdr->src, netif->ip_addr);
dirkx	0:a259777c45a3	602	} else {
dirkx	0:a259777c45a3	603	/* src cannot be NULL here */
dirkx	0:a259777c45a3	604	ip_addr_copy(iphdr->src, *src);
dirkx	0:a259777c45a3	605	}
dirkx	0:a259777c45a3	606
dirkx	0:a259777c45a3	607	IPH_CHKSUM_SET(iphdr, 0);
dirkx	0:a259777c45a3	608	#if CHECKSUM_GEN_IP
dirkx	0:a259777c45a3	609	IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
dirkx	0:a259777c45a3	610	#endif
dirkx	0:a259777c45a3	611	} else {
dirkx	0:a259777c45a3	612	/* IP header already included in p */
dirkx	0:a259777c45a3	613	iphdr = (struct ip_hdr *)p->payload;
dirkx	0:a259777c45a3	614	dest = &(iphdr->dest);
dirkx	0:a259777c45a3	615	}
dirkx	0:a259777c45a3	616
dirkx	0:a259777c45a3	617	IP_STATS_INC(ip.xmit);
dirkx	0:a259777c45a3	618
dirkx	0:a259777c45a3	619	LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
dirkx	0:a259777c45a3	620	ip_debug_print(p);
dirkx	0:a259777c45a3	621
dirkx	0:a259777c45a3	622	#if ENABLE_LOOPBACK
dirkx	0:a259777c45a3	623	if (ip_addr_cmp(dest, &netif->ip_addr)) {
dirkx	0:a259777c45a3	624	/* Packet to self, enqueue it for loopback */
dirkx	0:a259777c45a3	625	LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
dirkx	0:a259777c45a3	626	return netif_loop_output(netif, p, dest);
dirkx	0:a259777c45a3	627	}
dirkx	0:a259777c45a3	628	#endif /* ENABLE_LOOPBACK */
dirkx	0:a259777c45a3	629	#if IP_FRAG
dirkx	0:a259777c45a3	630	/* don't fragment if interface has mtu set to 0 [loopif] */
dirkx	0:a259777c45a3	631	if (netif->mtu && (p->tot_len > netif->mtu)) {
dirkx	0:a259777c45a3	632	return ip_frag(p,netif,dest);
dirkx	0:a259777c45a3	633	}
dirkx	0:a259777c45a3	634	#endif
dirkx	0:a259777c45a3	635
dirkx	0:a259777c45a3	636	LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
dirkx	0:a259777c45a3	637	return netif->output(netif, p, dest);
dirkx	0:a259777c45a3	638	}
dirkx	0:a259777c45a3	639
dirkx	0:a259777c45a3	640	/**
dirkx	0:a259777c45a3	641	* Simple interface to ip_output_if. It finds the outgoing network
dirkx	0:a259777c45a3	642	* interface and calls upon ip_output_if to do the actual work.
dirkx	0:a259777c45a3	643	*
dirkx	0:a259777c45a3	644	* @param p the packet to send (p->payload points to the data, e.g. next
dirkx	0:a259777c45a3	645	protocol header; if dest == IP_HDRINCL, p already includes an IP
dirkx	0:a259777c45a3	646	header and p->payload points to that IP header)
dirkx	0:a259777c45a3	647	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
dirkx	0:a259777c45a3	648	* IP address of the netif used to send is used as source address)
dirkx	0:a259777c45a3	649	* @param dest the destination IP address to send the packet to
dirkx	0:a259777c45a3	650	* @param ttl the TTL value to be set in the IP header
dirkx	0:a259777c45a3	651	* @param tos the TOS value to be set in the IP header
dirkx	0:a259777c45a3	652	* @param proto the PROTOCOL to be set in the IP header
dirkx	0:a259777c45a3	653	*
dirkx	0:a259777c45a3	654	* @return ERR_RTE if no route is found
dirkx	0:a259777c45a3	655	* see ip_output_if() for more return values
dirkx	0:a259777c45a3	656	*/
dirkx	0:a259777c45a3	657	err_t
dirkx	0:a259777c45a3	658	ip_output(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
dirkx	0:a259777c45a3	659	u8_t ttl, u8_t tos, u8_t proto)
dirkx	0:a259777c45a3	660	{
dirkx	0:a259777c45a3	661	struct netif *netif;
dirkx	0:a259777c45a3	662
dirkx	0:a259777c45a3	663	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
dirkx	0:a259777c45a3	664	gets altered as the packet is passed down the stack */
dirkx	0:a259777c45a3	665	LWIP_ASSERT("p->ref == 1", p->ref == 1);
dirkx	0:a259777c45a3	666
dirkx	0:a259777c45a3	667	if ((netif = ip_route(dest)) == NULL) {
dirkx	0:a259777c45a3	668	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
dirkx	0:a259777c45a3	669	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
dirkx	0:a259777c45a3	670	IP_STATS_INC(ip.rterr);
dirkx	0:a259777c45a3	671	return ERR_RTE;
dirkx	0:a259777c45a3	672	}
dirkx	0:a259777c45a3	673
dirkx	0:a259777c45a3	674	return ip_output_if(p, src, dest, ttl, tos, proto, netif);
dirkx	0:a259777c45a3	675	}
dirkx	0:a259777c45a3	676
dirkx	0:a259777c45a3	677	#if LWIP_NETIF_HWADDRHINT
dirkx	0:a259777c45a3	678	/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
dirkx	0:a259777c45a3	679	* before calling ip_output_if.
dirkx	0:a259777c45a3	680	*
dirkx	0:a259777c45a3	681	* @param p the packet to send (p->payload points to the data, e.g. next
dirkx	0:a259777c45a3	682	protocol header; if dest == IP_HDRINCL, p already includes an IP
dirkx	0:a259777c45a3	683	header and p->payload points to that IP header)
dirkx	0:a259777c45a3	684	* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
dirkx	0:a259777c45a3	685	* IP address of the netif used to send is used as source address)
dirkx	0:a259777c45a3	686	* @param dest the destination IP address to send the packet to
dirkx	0:a259777c45a3	687	* @param ttl the TTL value to be set in the IP header
dirkx	0:a259777c45a3	688	* @param tos the TOS value to be set in the IP header
dirkx	0:a259777c45a3	689	* @param proto the PROTOCOL to be set in the IP header
dirkx	0:a259777c45a3	690	* @param addr_hint address hint pointer set to netif->addr_hint before
dirkx	0:a259777c45a3	691	* calling ip_output_if()
dirkx	0:a259777c45a3	692	*
dirkx	0:a259777c45a3	693	* @return ERR_RTE if no route is found
dirkx	0:a259777c45a3	694	* see ip_output_if() for more return values
dirkx	0:a259777c45a3	695	*/
dirkx	0:a259777c45a3	696	err_t
dirkx	0:a259777c45a3	697	ip_output_hinted(struct pbuf p, ip_addr_t src, ip_addr_t *dest,
dirkx	0:a259777c45a3	698	u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
dirkx	0:a259777c45a3	699	{
dirkx	0:a259777c45a3	700	struct netif *netif;
dirkx	0:a259777c45a3	701	err_t err;
dirkx	0:a259777c45a3	702
dirkx	0:a259777c45a3	703	/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
dirkx	0:a259777c45a3	704	gets altered as the packet is passed down the stack */
dirkx	0:a259777c45a3	705	LWIP_ASSERT("p->ref == 1", p->ref == 1);
dirkx	0:a259777c45a3	706
dirkx	0:a259777c45a3	707	if ((netif = ip_route(dest)) == NULL) {
dirkx	0:a259777c45a3	708	LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
dirkx	0:a259777c45a3	709	ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
dirkx	0:a259777c45a3	710	IP_STATS_INC(ip.rterr);
dirkx	0:a259777c45a3	711	return ERR_RTE;
dirkx	0:a259777c45a3	712	}
dirkx	0:a259777c45a3	713
dirkx	0:a259777c45a3	714	netif->addr_hint = addr_hint;
dirkx	0:a259777c45a3	715	err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
dirkx	0:a259777c45a3	716	netif->addr_hint = NULL;
dirkx	0:a259777c45a3	717
dirkx	0:a259777c45a3	718	return err;
dirkx	0:a259777c45a3	719	}
dirkx	0:a259777c45a3	720	#endif /* LWIP_NETIF_HWADDRHINT*/
dirkx	0:a259777c45a3	721
dirkx	0:a259777c45a3	722	#if IP_DEBUG
dirkx	0:a259777c45a3	723	/* Print an IP header by using LWIP_DEBUGF
dirkx	0:a259777c45a3	724	* @param p an IP packet, p->payload pointing to the IP header
dirkx	0:a259777c45a3	725	*/
dirkx	0:a259777c45a3	726	void
dirkx	0:a259777c45a3	727	ip_debug_print(struct pbuf *p)
dirkx	0:a259777c45a3	728	{
dirkx	0:a259777c45a3	729	struct ip_hdr iphdr = (struct ip_hdr ) p->payload;
dirkx	0:a259777c45a3	730	u8_t *payload;
dirkx	0:a259777c45a3	731
dirkx	0:a259777c45a3	732	payload = (u8_t *)iphdr + IP_HLEN;
dirkx	0:a259777c45a3	733
dirkx	0:a259777c45a3	734	LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
dirkx	0:a259777c45a3	735	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	736	LWIP_DEBUGF(IP_DEBUG, ("\|%2"S16_F" \|%2"S16_F" \| 0x%02"X16_F" \| %5"U16_F" \| (v, hl, tos, len)\n",
dirkx	0:a259777c45a3	737	IPH_V(iphdr),
dirkx	0:a259777c45a3	738	IPH_HL(iphdr),
dirkx	0:a259777c45a3	739	IPH_TOS(iphdr),
dirkx	0:a259777c45a3	740	ntohs(IPH_LEN(iphdr))));
dirkx	0:a259777c45a3	741	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	742	LWIP_DEBUGF(IP_DEBUG, ("\| %5"U16_F" \|%"U16_F"%"U16_F"%"U16_F"\| %4"U16_F" \| (id, flags, offset)\n",
dirkx	0:a259777c45a3	743	ntohs(IPH_ID(iphdr)),
dirkx	0:a259777c45a3	744	ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
dirkx	0:a259777c45a3	745	ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
dirkx	0:a259777c45a3	746	ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
dirkx	0:a259777c45a3	747	ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
dirkx	0:a259777c45a3	748	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	749	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| 0x%04"X16_F" \| (ttl, proto, chksum)\n",
dirkx	0:a259777c45a3	750	IPH_TTL(iphdr),
dirkx	0:a259777c45a3	751	IPH_PROTO(iphdr),
dirkx	0:a259777c45a3	752	ntohs(IPH_CHKSUM(iphdr))));
dirkx	0:a259777c45a3	753	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	754	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (src)\n",
dirkx	0:a259777c45a3	755	ip4_addr1_16(&iphdr->src),
dirkx	0:a259777c45a3	756	ip4_addr2_16(&iphdr->src),
dirkx	0:a259777c45a3	757	ip4_addr3_16(&iphdr->src),
dirkx	0:a259777c45a3	758	ip4_addr4_16(&iphdr->src)));
dirkx	0:a259777c45a3	759	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	760	LWIP_DEBUGF(IP_DEBUG, ("\| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| %3"U16_F" \| (dest)\n",
dirkx	0:a259777c45a3	761	ip4_addr1_16(&iphdr->dest),
dirkx	0:a259777c45a3	762	ip4_addr2_16(&iphdr->dest),
dirkx	0:a259777c45a3	763	ip4_addr3_16(&iphdr->dest),
dirkx	0:a259777c45a3	764	ip4_addr4_16(&iphdr->dest)));
dirkx	0:a259777c45a3	765	LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
dirkx	0:a259777c45a3	766	}
dirkx	0:a259777c45a3	767	#endif /* IP_DEBUG */

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Type:	Program
Mbed OS support:	Mbed 2 deprecated
Created:	14 Aug 2010
Imports:	49
Forks:	0
Commits:	1
Dependents:	0
Dependencies:	2
Followers:	1

lwip/core/ipv4/ip.c@0:a259777c45a3, 2010-08-14 (annotated)

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