www.pudn.com > lwip-1.3.0.rar > ip6.c
/*
* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Adam Dunkels
*
*/
/* ip.c
*
* This is the code for the IP layer for IPv6.
*
*/
#include "lwip/opt.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include "lwip/ip.h"
#include "lwip/inet.h"
#include "lwip/netif.h"
#include "lwip/icmp.h"
#include "lwip/udp.h"
#include "lwip/tcp.h"
#include "lwip/stats.h"
#include "arch/perf.h"
/* ip_init:
*
* Initializes the IP layer.
*/
void
ip_init(void)
{
}
/* ip_route:
*
* Finds the appropriate network interface for a given IP address. It searches the
* list of network interfaces linearly. A match is found if the masked IP address of
* the network interface equals the masked IP address given to the function.
*/
struct netif *
ip_route(struct ip_addr *dest)
{
struct netif *netif;
for(netif = netif_list; netif != NULL; netif = netif->next) {
if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
return netif;
}
}
return netif_default;
}
/* ip_forward:
*
* Forwards an IP packet. It finds an appropriate route for the packet, decrements
* the TTL value of the packet, adjusts the checksum and outputs the packet on the
* appropriate interface.
*/
static void
ip_forward(struct pbuf *p, struct ip_hdr *iphdr)
{
struct netif *netif;
PERF_START;
if ((netif = ip_route((struct ip_addr *)&(iphdr->dest))) == NULL) {
LWIP_DEBUGF(IP_DEBUG, ("ip_input: no forwarding route found for "));
#if IP_DEBUG
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
#endif /* IP_DEBUG */
LWIP_DEBUGF(IP_DEBUG, ("\n"));
pbuf_free(p);
return;
}
/* Decrement TTL and send ICMP if ttl == 0. */
if (--iphdr->hoplim == 0) {
#if LWIP_ICMP
/* Don't send ICMP messages in response to ICMP messages */
if (iphdr->nexthdr != IP_PROTO_ICMP) {
icmp_time_exceeded(p, ICMP_TE_TTL);
}
#endif /* LWIP_ICMP */
pbuf_free(p);
return;
}
/* Incremental update of the IP checksum. */
/* if (iphdr->chksum >= htons(0xffff - 0x100)) {
iphdr->chksum += htons(0x100) + 1;
} else {
iphdr->chksum += htons(0x100);
}*/
LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to "));
#if IP_DEBUG
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
#endif /* IP_DEBUG */
LWIP_DEBUGF(IP_DEBUG, ("\n"));
IP_STATS_INC(ip.fw);
IP_STATS_INC(ip.xmit);
PERF_STOP("ip_forward");
netif->output(netif, p, (struct ip_addr *)&(iphdr->dest));
}
/* ip_input:
*
* This function is called by the network interface device driver when an IP packet is
* received. The function does the basic checks of the IP header such as packet size
* being at least larger than the header size etc. If the packet was not destined for
* us, the packet is forwarded (using ip_forward). The IP checksum is always checked.
*
* Finally, the packet is sent to the upper layer protocol input function.
*/
void
ip_input(struct pbuf *p, struct netif *inp) {
struct ip_hdr *iphdr;
struct netif *netif;
PERF_START;
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
IP_STATS_INC(ip.recv);
/* identify the IP header */
iphdr = p->payload;
if (iphdr->v != 6) {
LWIP_DEBUGF(IP_DEBUG, ("IP packet dropped due to bad version number\n"));
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
pbuf_free(p);
IP_STATS_INC(ip.err);
IP_STATS_INC(ip.drop);
return;
}
/* is this packet for us? */
for(netif = netif_list; netif != NULL; netif = netif->next) {
#if IP_DEBUG
LWIP_DEBUGF(IP_DEBUG, ("ip_input: iphdr->dest "));
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
LWIP_DEBUGF(IP_DEBUG, ("netif->ip_addr "));
ip_addr_debug_print(IP_DEBUG, ((struct ip_addr *)&(iphdr->dest)));
LWIP_DEBUGF(IP_DEBUG, ("\n"));
#endif /* IP_DEBUG */
if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr))) {
break;
}
}
if (netif == NULL) {
/* packet not for us, route or discard */
#if IP_FORWARD
ip_forward(p, iphdr);
#endif
pbuf_free(p);
return;
}
pbuf_realloc(p, IP_HLEN + ntohs(iphdr->len));
/* send to upper layers */
#if IP_DEBUG
/* LWIP_DEBUGF("ip_input: \n");
ip_debug_print(p);
LWIP_DEBUGF("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len);*/
#endif /* IP_DEBUG */
if(pbuf_header(p, -IP_HLEN)) {
LWIP_ASSERT("Can't move over header in packet", 0);
return;
}
switch (iphdr->nexthdr) {
case IP_PROTO_UDP:
udp_input(p, inp);
break;
case IP_PROTO_TCP:
tcp_input(p, inp);
break;
#if LWIP_ICMP
case IP_PROTO_ICMP:
icmp_input(p, inp);
break;
#endif /* LWIP_ICMP */
default:
#if LWIP_ICMP
/* send ICMP destination protocol unreachable */
icmp_dest_unreach(p, ICMP_DUR_PROTO);
#endif /* LWIP_ICMP */
pbuf_free(p);
LWIP_DEBUGF(IP_DEBUG, ("Unsupported transport protocol %"U16_F"\n",
iphdr->nexthdr));
IP_STATS_INC(ip.proterr);
IP_STATS_INC(ip.drop);
}
PERF_STOP("ip_input");
}
/* ip_output_if:
*
* Sends an IP packet on a network interface. This function constructs the IP header
* and calculates the IP header checksum. If the source IP address is NULL,
* the IP address of the outgoing network interface is filled in as source address.
*/
err_t
ip_output_if (struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl,
u8_t proto, struct netif *netif)
{
struct ip_hdr *iphdr;
PERF_START;
LWIP_DEBUGF(IP_DEBUG, ("len %"U16_F" tot_len %"U16_F"\n", p->len, p->tot_len));
if (pbuf_header(p, IP_HLEN)) {
LWIP_DEBUGF(IP_DEBUG, ("ip_output: not enough room for IP header in pbuf\n"));
IP_STATS_INC(ip.err);
return ERR_BUF;
}
LWIP_DEBUGF(IP_DEBUG, ("len %"U16_F" tot_len %"U16_F"\n", p->len, p->tot_len));
iphdr = p->payload;
if (dest != IP_HDRINCL) {
LWIP_DEBUGF(IP_DEBUG, ("!IP_HDRLINCL\n"));
iphdr->hoplim = ttl;
iphdr->nexthdr = proto;
iphdr->len = htons(p->tot_len - IP_HLEN);
ip_addr_set(&(iphdr->dest), dest);
iphdr->v = 6;
if (ip_addr_isany(src)) {
ip_addr_set(&(iphdr->src), &(netif->ip_addr));
} else {
ip_addr_set(&(iphdr->src), src);
}
} else {
dest = &(iphdr->dest);
}
IP_STATS_INC(ip.xmit);
LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c (len %"U16_F")\n", netif->name[0], netif->name[1], p->tot_len));
#if IP_DEBUG
ip_debug_print(p);
#endif /* IP_DEBUG */
PERF_STOP("ip_output_if");
return netif->output(netif, p, dest);
}
/* ip_output:
*
* Simple interface to ip_output_if. It finds the outgoing network interface and
* calls upon ip_output_if to do the actual work.
*/
err_t
ip_output(struct pbuf *p, struct ip_addr *src, struct ip_addr *dest,
u8_t ttl, u8_t proto)
{
struct netif *netif;
if ((netif = ip_route(dest)) == NULL) {
LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to 0x%"X32_F"\n", dest->addr));
IP_STATS_INC(ip.rterr);
return ERR_RTE;
}
return ip_output_if (p, src, dest, ttl, proto, netif);
}
#if IP_DEBUG
void
ip_debug_print(struct pbuf *p)
{
struct ip_hdr *iphdr = p->payload;
LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" | %"X16_F"%"X16_F" | %"X16_F"%"X16_F" | (v, traffic class, flow label)\n",
iphdr->v,
iphdr->tclass1, iphdr->tclass2,
iphdr->flow1, iphdr->flow2));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" | %2"U16_F" | %2"U16_F" | (len, nexthdr, hoplim)\n",
ntohs(iphdr->len),
iphdr->nexthdr,
iphdr->hoplim));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (src)\n",
(ntohl(iphdr->src.addr[0]) >> 16) & 0xffff,
ntohl(iphdr->src.addr[0]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (src)\n",
(ntohl(iphdr->src.addr[1]) >> 16) & 0xffff,
ntohl(iphdr->src.addr[1]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (src)\n",
(ntohl(iphdr->src.addr[2]) >> 16) & 0xffff,
ntohl(iphdr->src.addr[2]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (src)\n",
(ntohl(iphdr->src.addr[3]) >> 16) & 0xffff,
ntohl(iphdr->src.addr[3]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (dest)\n",
(ntohl(iphdr->dest.addr[0]) >> 16) & 0xffff,
ntohl(iphdr->dest.addr[0]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (dest)\n",
(ntohl(iphdr->dest.addr[1]) >> 16) & 0xffff,
ntohl(iphdr->dest.addr[1]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (dest)\n",
(ntohl(iphdr->dest.addr[2]) >> 16) & 0xffff,
ntohl(iphdr->dest.addr[2]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("| %4"X32_F" | %4"X32_F" | (dest)\n",
(ntohl(iphdr->dest.addr[3]) >> 16) & 0xffff,
ntohl(iphdr->dest.addr[3]) & 0xffff));
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
}
#endif /* IP_DEBUG */