857 lines
30 KiB
C
857 lines
30 KiB
C
/**
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* @file
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* This is the IPv4 layer implementation for incoming and outgoing IP traffic.
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*
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* @see ip_frag.c
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*
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*/
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/*
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* Copyright (c) 2001-2004 Swedish Institute of Computer Science.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without modification,
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* are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
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* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
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* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
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* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
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* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
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* OF SUCH DAMAGE.
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*
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* This file is part of the lwIP TCP/IP stack.
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*
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* Author: Adam Dunkels <adam@sics.se>
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*
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*/
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#include "lwip/opt.h"
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#include "lwip/ip.h"
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#include "lwip/def.h"
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#include "lwip/mem.h"
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#include "lwip/ip_frag.h"
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#include "lwip/inet_chksum.h"
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#include "lwip/netif.h"
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#include "lwip/icmp.h"
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#include "lwip/igmp.h"
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#include "lwip/raw.h"
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#include "lwip/udp.h"
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#include "lwip/tcp_impl.h"
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#include "lwip/snmp.h"
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#include "lwip/dhcp.h"
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#include "lwip/autoip.h"
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#include "lwip/stats.h"
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#include "arch/perf.h"
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#include <string.h>
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/** Set this to 0 in the rare case of wanting to call an extra function to
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* generate the IP checksum (in contrast to calculating it on-the-fly). */
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#ifndef LWIP_INLINE_IP_CHKSUM
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#define LWIP_INLINE_IP_CHKSUM 1
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#endif
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#if LWIP_INLINE_IP_CHKSUM && CHECKSUM_GEN_IP
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#define CHECKSUM_GEN_IP_INLINE 1
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#else
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#define CHECKSUM_GEN_IP_INLINE 0
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#endif
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#if LWIP_DHCP || defined(LWIP_IP_ACCEPT_UDP_PORT)
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#define IP_ACCEPT_LINK_LAYER_ADDRESSING 1
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/** Some defines for DHCP to let link-layer-addressed packets through while the
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* netif is down.
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* To use this in your own application/protocol, define LWIP_IP_ACCEPT_UDP_PORT
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* to return 1 if the port is accepted and 0 if the port is not accepted.
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*/
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#if LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT)
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/* accept DHCP client port and custom port */
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#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (((port) == PP_NTOHS(DHCP_CLIENT_PORT)) \
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|| (LWIP_IP_ACCEPT_UDP_PORT(port)))
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#elif defined(LWIP_IP_ACCEPT_UDP_PORT) /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
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/* accept custom port only */
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#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) (LWIP_IP_ACCEPT_UDP_PORT(dst_port))
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#else /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
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/* accept DHCP client port only */
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#define IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(port) ((port) == PP_NTOHS(DHCP_CLIENT_PORT))
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#endif /* LWIP_DHCP && defined(LWIP_IP_ACCEPT_UDP_PORT) */
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#else /* LWIP_DHCP */
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#define IP_ACCEPT_LINK_LAYER_ADDRESSING 0
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#endif /* LWIP_DHCP */
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/**
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* The interface that provided the packet for the current callback
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* invocation.
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*/
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struct netif *current_netif;
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/**
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* Header of the input packet currently being processed.
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*/
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const struct ip_hdr *current_header;
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/** Source IP address of current_header */
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ip_addr_t current_iphdr_src;
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/** Destination IP address of current_header */
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ip_addr_t current_iphdr_dest;
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/** The IP header ID of the next outgoing IP packet */
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static u16_t ip_id;
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/**
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* Finds the appropriate network interface for a given IP address. It
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* searches the list of network interfaces linearly. A match is found
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* if the masked IP address of the network interface equals the masked
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* IP address given to the function.
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*
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* @param dest the destination IP address for which to find the route
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* @return the netif on which to send to reach dest
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*/
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struct netif *
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ip_route(ip_addr_t *dest)
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{
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struct netif *netif;
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/* iterate through netifs */
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for(netif = netif_list; netif != NULL; netif = netif->next) {
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/* network mask matches? */
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if (netif_is_up(netif)) {
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if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) {
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/* return netif on which to forward IP packet */
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return netif;
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}
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}
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}
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if ((netif_default == NULL) || (!netif_is_up(netif_default))) {
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
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IP_STATS_INC(ip.rterr);
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snmp_inc_ipoutnoroutes();
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return NULL;
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}
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/* no matching netif found, use default netif */
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return netif_default;
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}
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#if IP_FORWARD
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/**
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* Forwards an IP packet. It finds an appropriate route for the
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* packet, decrements the TTL value of the packet, adjusts the
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* checksum and outputs the packet on the appropriate interface.
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*
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* @param p the packet to forward (p->payload points to IP header)
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* @param iphdr the IP header of the input packet
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* @param inp the netif on which this packet was received
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*/
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static void
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ip_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp)
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{
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struct netif *netif;
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PERF_START;
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/* RFC3927 2.7: do not forward link-local addresses */
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if (ip_addr_islinklocal(¤t_iphdr_dest)) {
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LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not forwarding LLA %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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ip4_addr1_16(¤t_iphdr_dest), ip4_addr2_16(¤t_iphdr_dest),
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ip4_addr3_16(¤t_iphdr_dest), ip4_addr4_16(¤t_iphdr_dest)));
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goto return_noroute;
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}
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/* Find network interface where to forward this IP packet to. */
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netif = ip_route(¤t_iphdr_dest);
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if (netif == NULL) {
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LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for %"U16_F".%"U16_F".%"U16_F".%"U16_F" found\n",
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ip4_addr1_16(¤t_iphdr_dest), ip4_addr2_16(¤t_iphdr_dest),
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ip4_addr3_16(¤t_iphdr_dest), ip4_addr4_16(¤t_iphdr_dest)));
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goto return_noroute;
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}
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/* Do not forward packets onto the same network interface on which
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* they arrived. */
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if (netif == inp) {
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LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n"));
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goto return_noroute;
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}
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/* decrement TTL */
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IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1);
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/* send ICMP if TTL == 0 */
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if (IPH_TTL(iphdr) == 0) {
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snmp_inc_ipinhdrerrors();
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#if LWIP_ICMP
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/* Don't send ICMP messages in response to ICMP messages */
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if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) {
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icmp_time_exceeded(p, ICMP_TE_TTL);
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}
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#endif /* LWIP_ICMP */
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return;
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}
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/* Incrementally update the IP checksum. */
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if (IPH_CHKSUM(iphdr) >= PP_HTONS(0xffff - 0x100)) {
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IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100) + 1);
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} else {
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IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + PP_HTONS(0x100));
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}
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LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
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ip4_addr1_16(¤t_iphdr_dest), ip4_addr2_16(¤t_iphdr_dest),
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ip4_addr3_16(¤t_iphdr_dest), ip4_addr4_16(¤t_iphdr_dest)));
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IP_STATS_INC(ip.fw);
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IP_STATS_INC(ip.xmit);
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snmp_inc_ipforwdatagrams();
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PERF_STOP("ip_forward");
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/* transmit pbuf on chosen interface */
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netif->output(netif, p, ¤t_iphdr_dest);
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return;
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return_noroute:
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snmp_inc_ipoutnoroutes();
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}
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#endif /* IP_FORWARD */
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/**
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* This function is called by the network interface device driver when
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* an IP packet is received. The function does the basic checks of the
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* IP header such as packet size being at least larger than the header
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* size etc. If the packet was not destined for us, the packet is
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* forwarded (using ip_forward). The IP checksum is always checked.
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*
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* Finally, the packet is sent to the upper layer protocol input function.
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*
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* @param p the received IP packet (p->payload points to IP header)
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* @param inp the netif on which this packet was received
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* @return ERR_OK if the packet was processed (could return ERR_* if it wasn't
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* processed, but currently always returns ERR_OK)
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*/
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err_t
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ip_input(struct pbuf *p, struct netif *inp)
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{
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struct ip_hdr *iphdr;
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struct netif *netif;
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u16_t iphdr_hlen;
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u16_t iphdr_len;
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#if IP_ACCEPT_LINK_LAYER_ADDRESSING
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int check_ip_src=1;
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#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
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IP_STATS_INC(ip.recv);
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snmp_inc_ipinreceives();
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/* identify the IP header */
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iphdr = (struct ip_hdr *)p->payload;
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if (IPH_V(iphdr) != 4) {
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr)));
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ip_debug_print(p);
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pbuf_free(p);
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IP_STATS_INC(ip.err);
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IP_STATS_INC(ip.drop);
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snmp_inc_ipinhdrerrors();
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return ERR_OK;
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}
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/* obtain IP header length in number of 32-bit words */
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iphdr_hlen = IPH_HL(iphdr);
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/* calculate IP header length in bytes */
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iphdr_hlen *= 4;
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/* obtain ip length in bytes */
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iphdr_len = ntohs(IPH_LEN(iphdr));
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/* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */
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if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len)) {
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if (iphdr_hlen > p->len) {
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
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("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n",
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iphdr_hlen, p->len));
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}
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if (iphdr_len > p->tot_len) {
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
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("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n",
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iphdr_len, p->tot_len));
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}
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/* free (drop) packet pbufs */
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pbuf_free(p);
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IP_STATS_INC(ip.lenerr);
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IP_STATS_INC(ip.drop);
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snmp_inc_ipindiscards();
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return ERR_OK;
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}
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/* verify checksum */
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#if CHECKSUM_CHECK_IP
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if (inet_chksum(iphdr, iphdr_hlen) != 0) {
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS,
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("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen)));
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ip_debug_print(p);
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pbuf_free(p);
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IP_STATS_INC(ip.chkerr);
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IP_STATS_INC(ip.drop);
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snmp_inc_ipinhdrerrors();
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return ERR_OK;
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}
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#endif
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/* Trim pbuf. This should have been done at the netif layer,
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* but we'll do it anyway just to be sure that its done. */
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pbuf_realloc(p, iphdr_len);
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/* copy IP addresses to aligned ip_addr_t */
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ip_addr_copy(current_iphdr_dest, iphdr->dest);
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ip_addr_copy(current_iphdr_src, iphdr->src);
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/* match packet against an interface, i.e. is this packet for us? */
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#if LWIP_IGMP
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if (ip_addr_ismulticast(¤t_iphdr_dest)) {
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if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, ¤t_iphdr_dest))) {
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netif = inp;
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} else {
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netif = NULL;
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}
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} else
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#endif /* LWIP_IGMP */
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{
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/* start trying with inp. if that's not acceptable, start walking the
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list of configured netifs.
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'first' is used as a boolean to mark whether we started walking the list */
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int first = 1;
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netif = inp;
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do {
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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",
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ip4_addr_get_u32(&iphdr->dest), ip4_addr_get_u32(&netif->ip_addr),
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ip4_addr_get_u32(&iphdr->dest) & ip4_addr_get_u32(&netif->netmask),
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ip4_addr_get_u32(&netif->ip_addr) & ip4_addr_get_u32(&netif->netmask),
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ip4_addr_get_u32(&iphdr->dest) & ~ip4_addr_get_u32(&netif->netmask)));
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/* interface is up and configured? */
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if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) {
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/* unicast to this interface address? */
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if (ip_addr_cmp(¤t_iphdr_dest, &(netif->ip_addr)) ||
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/* or broadcast on this interface network address? */
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ip_addr_isbroadcast(¤t_iphdr_dest, netif)) {
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LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n",
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netif->name[0], netif->name[1]));
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/* break out of for loop */
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break;
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}
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#if LWIP_AUTOIP
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/* connections to link-local addresses must persist after changing
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the netif's address (RFC3927 ch. 1.9) */
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if ((netif->autoip != NULL) &&
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ip_addr_cmp(¤t_iphdr_dest, &(netif->autoip->llipaddr))) {
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LWIP_DEBUGF(IP_DEBUG, ("ip_input: LLA packet accepted on interface %c%c\n",
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netif->name[0], netif->name[1]));
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/* break out of for loop */
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break;
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}
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#endif /* LWIP_AUTOIP */
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}
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if (first) {
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first = 0;
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netif = netif_list;
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} else {
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netif = netif->next;
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}
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if (netif == inp) {
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netif = netif->next;
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}
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} while(netif != NULL);
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}
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#if IP_ACCEPT_LINK_LAYER_ADDRESSING
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/* Pass DHCP messages regardless of destination address. DHCP traffic is addressed
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* using link layer addressing (such as Ethernet MAC) so we must not filter on IP.
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* According to RFC 1542 section 3.1.1, referred by RFC 2131).
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*
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* If you want to accept private broadcast communication while a netif is down,
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* define LWIP_IP_ACCEPT_UDP_PORT(dst_port), e.g.:
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*
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* #define LWIP_IP_ACCEPT_UDP_PORT(dst_port) ((dst_port) == PP_NTOHS(12345))
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*/
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if (netif == NULL) {
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/* remote port is DHCP server? */
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if (IPH_PROTO(iphdr) == IP_PROTO_UDP) {
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struct udp_hdr *udphdr = (struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen);
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n",
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ntohs(udphdr->dest)));
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if (IP_ACCEPT_LINK_LAYER_ADDRESSED_PORT(udphdr->dest)) {
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n"));
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netif = inp;
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check_ip_src = 0;
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}
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}
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}
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#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
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/* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
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#if IP_ACCEPT_LINK_LAYER_ADDRESSING
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/* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
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if (check_ip_src && !ip_addr_isany(¤t_iphdr_src))
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#endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
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{ if ((ip_addr_isbroadcast(¤t_iphdr_src, inp)) ||
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(ip_addr_ismulticast(¤t_iphdr_src))) {
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/* packet source is not valid */
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LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n"));
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/* free (drop) packet pbufs */
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pbuf_free(p);
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IP_STATS_INC(ip.drop);
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snmp_inc_ipinaddrerrors();
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snmp_inc_ipindiscards();
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return ERR_OK;
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}
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}
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/* packet not for us? */
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if (netif == NULL) {
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/* packet not for us, route or discard */
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|
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: packet not for us.\n"));
|
|
#if IP_FORWARD
|
|
/* non-broadcast packet? */
|
|
if (!ip_addr_isbroadcast(¤t_iphdr_dest, inp)) {
|
|
/* try to forward IP packet on (other) interfaces */
|
|
ip_forward(p, iphdr, inp);
|
|
} else
|
|
#endif /* IP_FORWARD */
|
|
{
|
|
snmp_inc_ipinaddrerrors();
|
|
snmp_inc_ipindiscards();
|
|
}
|
|
pbuf_free(p);
|
|
return ERR_OK;
|
|
}
|
|
/* packet consists of multiple fragments? */
|
|
if ((IPH_OFFSET(iphdr) & PP_HTONS(IP_OFFMASK | IP_MF)) != 0) {
|
|
#if IP_REASSEMBLY /* packet fragment reassembly code present? */
|
|
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",
|
|
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));
|
|
/* reassemble the packet*/
|
|
p = ip_reass(p);
|
|
/* packet not fully reassembled yet? */
|
|
if (p == NULL) {
|
|
return ERR_OK;
|
|
}
|
|
iphdr = (struct ip_hdr *)p->payload;
|
|
#else /* IP_REASSEMBLY == 0, no packet fragment reassembly code present */
|
|
pbuf_free(p);
|
|
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since it was fragmented (0x%"X16_F") (while IP_REASSEMBLY == 0).\n",
|
|
ntohs(IPH_OFFSET(iphdr))));
|
|
IP_STATS_INC(ip.opterr);
|
|
IP_STATS_INC(ip.drop);
|
|
/* unsupported protocol feature */
|
|
snmp_inc_ipinunknownprotos();
|
|
return ERR_OK;
|
|
#endif /* IP_REASSEMBLY */
|
|
}
|
|
|
|
#if IP_OPTIONS_ALLOWED == 0 /* no support for IP options in the IP header? */
|
|
|
|
#if LWIP_IGMP
|
|
/* there is an extra "router alert" option in IGMP messages which we allow for but do not police */
|
|
if((iphdr_hlen > IP_HLEN) && (IPH_PROTO(iphdr) != IP_PROTO_IGMP)) {
|
|
#else
|
|
if (iphdr_hlen > IP_HLEN) {
|
|
#endif /* LWIP_IGMP */
|
|
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("IP packet dropped since there were IP options (while IP_OPTIONS_ALLOWED == 0).\n"));
|
|
pbuf_free(p);
|
|
IP_STATS_INC(ip.opterr);
|
|
IP_STATS_INC(ip.drop);
|
|
/* unsupported protocol feature */
|
|
snmp_inc_ipinunknownprotos();
|
|
return ERR_OK;
|
|
}
|
|
#endif /* IP_OPTIONS_ALLOWED == 0 */
|
|
|
|
/* send to upper layers */
|
|
LWIP_DEBUGF(IP_DEBUG, ("ip_input: \n"));
|
|
ip_debug_print(p);
|
|
LWIP_DEBUGF(IP_DEBUG, ("ip_input: p->len %"U16_F" p->tot_len %"U16_F"\n", p->len, p->tot_len));
|
|
|
|
current_netif = inp;
|
|
current_header = iphdr;
|
|
|
|
#if LWIP_RAW
|
|
/* raw input did not eat the packet? */
|
|
if (raw_input(p, inp) == 0)
|
|
#endif /* LWIP_RAW */
|
|
{
|
|
|
|
switch (IPH_PROTO(iphdr)) {
|
|
#if LWIP_UDP
|
|
case IP_PROTO_UDP:
|
|
#if LWIP_UDPLITE
|
|
case IP_PROTO_UDPLITE:
|
|
#endif /* LWIP_UDPLITE */
|
|
snmp_inc_ipindelivers();
|
|
udp_input(p, inp);
|
|
break;
|
|
#endif /* LWIP_UDP */
|
|
#if LWIP_TCP
|
|
case IP_PROTO_TCP:
|
|
snmp_inc_ipindelivers();
|
|
tcp_input(p, inp);
|
|
break;
|
|
#endif /* LWIP_TCP */
|
|
#if LWIP_ICMP
|
|
case IP_PROTO_ICMP:
|
|
snmp_inc_ipindelivers();
|
|
icmp_input(p, inp);
|
|
break;
|
|
#endif /* LWIP_ICMP */
|
|
#if LWIP_IGMP
|
|
case IP_PROTO_IGMP:
|
|
igmp_input(p, inp, ¤t_iphdr_dest);
|
|
break;
|
|
#endif /* LWIP_IGMP */
|
|
default:
|
|
#if LWIP_ICMP
|
|
/* send ICMP destination protocol unreachable unless is was a broadcast */
|
|
if (!ip_addr_isbroadcast(¤t_iphdr_dest, inp) &&
|
|
!ip_addr_ismulticast(¤t_iphdr_dest)) {
|
|
p->payload = iphdr;
|
|
icmp_dest_unreach(p, ICMP_DUR_PROTO);
|
|
}
|
|
#endif /* LWIP_ICMP */
|
|
pbuf_free(p);
|
|
|
|
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr)));
|
|
|
|
IP_STATS_INC(ip.proterr);
|
|
IP_STATS_INC(ip.drop);
|
|
snmp_inc_ipinunknownprotos();
|
|
}
|
|
}
|
|
|
|
current_netif = NULL;
|
|
current_header = NULL;
|
|
ip_addr_set_any(¤t_iphdr_src);
|
|
ip_addr_set_any(¤t_iphdr_dest);
|
|
|
|
return ERR_OK;
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
* If the destination IP address is IP_HDRINCL, p is assumed to already
|
|
* include an IP header and p->payload points to it instead of the data.
|
|
*
|
|
* @param p the packet to send (p->payload points to the data, e.g. next
|
|
protocol header; if dest == IP_HDRINCL, p already includes an IP
|
|
header and p->payload points to that IP header)
|
|
* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
|
|
* IP address of the netif used to send is used as source address)
|
|
* @param dest the destination IP address to send the packet to
|
|
* @param ttl the TTL value to be set in the IP header
|
|
* @param tos the TOS value to be set in the IP header
|
|
* @param proto the PROTOCOL to be set in the IP header
|
|
* @param netif the netif on which to send this packet
|
|
* @return ERR_OK if the packet was sent OK
|
|
* ERR_BUF if p doesn't have enough space for IP/LINK headers
|
|
* returns errors returned by netif->output
|
|
*
|
|
* @note ip_id: RFC791 "some host may be able to simply use
|
|
* unique identifiers independent of destination"
|
|
*/
|
|
err_t
|
|
ip_output_if(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest,
|
|
u8_t ttl, u8_t tos,
|
|
u8_t proto, struct netif *netif)
|
|
{
|
|
#if IP_OPTIONS_SEND
|
|
return ip_output_if_opt(p, src, dest, ttl, tos, proto, netif, NULL, 0);
|
|
}
|
|
|
|
/**
|
|
* Same as ip_output_if() but with the possibility to include IP options:
|
|
*
|
|
* @ param ip_options pointer to the IP options, copied into the IP header
|
|
* @ param optlen length of ip_options
|
|
*/
|
|
err_t ip_output_if_opt(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest,
|
|
u8_t ttl, u8_t tos, u8_t proto, struct netif *netif, void *ip_options,
|
|
u16_t optlen)
|
|
{
|
|
#endif /* IP_OPTIONS_SEND */
|
|
struct ip_hdr *iphdr;
|
|
ip_addr_t dest_addr;
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
u32_t chk_sum = 0;
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
|
|
/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
|
|
gets altered as the packet is passed down the stack */
|
|
LWIP_ASSERT("p->ref == 1", p->ref == 1);
|
|
|
|
snmp_inc_ipoutrequests();
|
|
|
|
/* Should the IP header be generated or is it already included in p? */
|
|
if (dest != IP_HDRINCL) {
|
|
u16_t ip_hlen = IP_HLEN;
|
|
#if IP_OPTIONS_SEND
|
|
u16_t optlen_aligned = 0;
|
|
if (optlen != 0) {
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
int i;
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
/* round up to a multiple of 4 */
|
|
optlen_aligned = ((optlen + 3) & ~3);
|
|
ip_hlen += optlen_aligned;
|
|
/* First write in the IP options */
|
|
if (pbuf_header(p, optlen_aligned)) {
|
|
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_output_if_opt: not enough room for IP options in pbuf\n"));
|
|
IP_STATS_INC(ip.err);
|
|
snmp_inc_ipoutdiscards();
|
|
return ERR_BUF;
|
|
}
|
|
MEMCPY(p->payload, ip_options, optlen);
|
|
if (optlen < optlen_aligned) {
|
|
/* zero the remaining bytes */
|
|
memset(((char*)p->payload) + optlen, 0, optlen_aligned - optlen);
|
|
}
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
for (i = 0; i < optlen_aligned; i += sizeof(u16_t)) {
|
|
chk_sum += ((u16_t*)p->payload)[i];
|
|
}
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
}
|
|
#endif /* IP_OPTIONS_SEND */
|
|
/* generate IP header */
|
|
if (pbuf_header(p, IP_HLEN)) {
|
|
LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_output: not enough room for IP header in pbuf\n"));
|
|
|
|
IP_STATS_INC(ip.err);
|
|
snmp_inc_ipoutdiscards();
|
|
return ERR_BUF;
|
|
}
|
|
|
|
iphdr = (struct ip_hdr *)p->payload;
|
|
LWIP_ASSERT("check that first pbuf can hold struct ip_hdr",
|
|
(p->len >= sizeof(struct ip_hdr)));
|
|
|
|
IPH_TTL_SET(iphdr, ttl);
|
|
IPH_PROTO_SET(iphdr, proto);
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
chk_sum += LWIP_MAKE_U16(proto, ttl);
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
|
|
/* dest cannot be NULL here */
|
|
ip_addr_copy(iphdr->dest, *dest);
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
chk_sum += ip4_addr_get_u32(&iphdr->dest) & 0xFFFF;
|
|
chk_sum += ip4_addr_get_u32(&iphdr->dest) >> 16;
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
|
|
IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos);
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
chk_sum += iphdr->_v_hl_tos;
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
IPH_LEN_SET(iphdr, htons(p->tot_len));
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
chk_sum += iphdr->_len;
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
IPH_OFFSET_SET(iphdr, 0);
|
|
IPH_ID_SET(iphdr, htons(ip_id));
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
chk_sum += iphdr->_id;
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
++ip_id;
|
|
|
|
if (ip_addr_isany(src)) {
|
|
ip_addr_copy(iphdr->src, netif->ip_addr);
|
|
} else {
|
|
/* src cannot be NULL here */
|
|
ip_addr_copy(iphdr->src, *src);
|
|
}
|
|
|
|
#if CHECKSUM_GEN_IP_INLINE
|
|
chk_sum += ip4_addr_get_u32(&iphdr->src) & 0xFFFF;
|
|
chk_sum += ip4_addr_get_u32(&iphdr->src) >> 16;
|
|
chk_sum = (chk_sum >> 16) + (chk_sum & 0xFFFF);
|
|
chk_sum = (chk_sum >> 16) + chk_sum;
|
|
chk_sum = ~chk_sum;
|
|
iphdr->_chksum = chk_sum; /* network order */
|
|
#else /* CHECKSUM_GEN_IP_INLINE */
|
|
IPH_CHKSUM_SET(iphdr, 0);
|
|
#if CHECKSUM_GEN_IP
|
|
IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen));
|
|
#endif
|
|
#endif /* CHECKSUM_GEN_IP_INLINE */
|
|
} else {
|
|
/* IP header already included in p */
|
|
iphdr = (struct ip_hdr *)p->payload;
|
|
ip_addr_copy(dest_addr, iphdr->dest);
|
|
dest = &dest_addr;
|
|
}
|
|
|
|
IP_STATS_INC(ip.xmit);
|
|
|
|
LWIP_DEBUGF(IP_DEBUG, ("ip_output_if: %c%c%"U16_F"\n", netif->name[0], netif->name[1], netif->num));
|
|
ip_debug_print(p);
|
|
|
|
#if ENABLE_LOOPBACK
|
|
if (ip_addr_cmp(dest, &netif->ip_addr)) {
|
|
/* Packet to self, enqueue it for loopback */
|
|
LWIP_DEBUGF(IP_DEBUG, ("netif_loop_output()"));
|
|
return netif_loop_output(netif, p, dest);
|
|
}
|
|
#if LWIP_IGMP
|
|
if ((p->flags & PBUF_FLAG_MCASTLOOP) != 0) {
|
|
netif_loop_output(netif, p, dest);
|
|
}
|
|
#endif /* LWIP_IGMP */
|
|
#endif /* ENABLE_LOOPBACK */
|
|
#if IP_FRAG
|
|
/* don't fragment if interface has mtu set to 0 [loopif] */
|
|
if (netif->mtu && (p->tot_len > netif->mtu)) {
|
|
return ip_frag(p, netif, dest);
|
|
}
|
|
#endif /* IP_FRAG */
|
|
|
|
LWIP_DEBUGF(IP_DEBUG, ("netif->output()"));
|
|
return netif->output(netif, p, dest);
|
|
}
|
|
|
|
/**
|
|
* Simple interface to ip_output_if. It finds the outgoing network
|
|
* interface and calls upon ip_output_if to do the actual work.
|
|
*
|
|
* @param p the packet to send (p->payload points to the data, e.g. next
|
|
protocol header; if dest == IP_HDRINCL, p already includes an IP
|
|
header and p->payload points to that IP header)
|
|
* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
|
|
* IP address of the netif used to send is used as source address)
|
|
* @param dest the destination IP address to send the packet to
|
|
* @param ttl the TTL value to be set in the IP header
|
|
* @param tos the TOS value to be set in the IP header
|
|
* @param proto the PROTOCOL to be set in the IP header
|
|
*
|
|
* @return ERR_RTE if no route is found
|
|
* see ip_output_if() for more return values
|
|
*/
|
|
err_t
|
|
ip_output(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest,
|
|
u8_t ttl, u8_t tos, u8_t proto)
|
|
{
|
|
struct netif *netif;
|
|
|
|
/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
|
|
gets altered as the packet is passed down the stack */
|
|
LWIP_ASSERT("p->ref == 1", p->ref == 1);
|
|
|
|
if ((netif = ip_route(dest)) == NULL) {
|
|
LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
|
ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
|
|
IP_STATS_INC(ip.rterr);
|
|
return ERR_RTE;
|
|
}
|
|
|
|
return ip_output_if(p, src, dest, ttl, tos, proto, netif);
|
|
}
|
|
|
|
#if LWIP_NETIF_HWADDRHINT
|
|
/** Like ip_output, but takes and addr_hint pointer that is passed on to netif->addr_hint
|
|
* before calling ip_output_if.
|
|
*
|
|
* @param p the packet to send (p->payload points to the data, e.g. next
|
|
protocol header; if dest == IP_HDRINCL, p already includes an IP
|
|
header and p->payload points to that IP header)
|
|
* @param src the source IP address to send from (if src == IP_ADDR_ANY, the
|
|
* IP address of the netif used to send is used as source address)
|
|
* @param dest the destination IP address to send the packet to
|
|
* @param ttl the TTL value to be set in the IP header
|
|
* @param tos the TOS value to be set in the IP header
|
|
* @param proto the PROTOCOL to be set in the IP header
|
|
* @param addr_hint address hint pointer set to netif->addr_hint before
|
|
* calling ip_output_if()
|
|
*
|
|
* @return ERR_RTE if no route is found
|
|
* see ip_output_if() for more return values
|
|
*/
|
|
err_t
|
|
ip_output_hinted(struct pbuf *p, ip_addr_t *src, ip_addr_t *dest,
|
|
u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint)
|
|
{
|
|
struct netif *netif;
|
|
err_t err;
|
|
|
|
/* pbufs passed to IP must have a ref-count of 1 as their payload pointer
|
|
gets altered as the packet is passed down the stack */
|
|
LWIP_ASSERT("p->ref == 1", p->ref == 1);
|
|
|
|
if ((netif = ip_route(dest)) == NULL) {
|
|
LWIP_DEBUGF(IP_DEBUG, ("ip_output: No route to %"U16_F".%"U16_F".%"U16_F".%"U16_F"\n",
|
|
ip4_addr1_16(dest), ip4_addr2_16(dest), ip4_addr3_16(dest), ip4_addr4_16(dest)));
|
|
IP_STATS_INC(ip.rterr);
|
|
return ERR_RTE;
|
|
}
|
|
|
|
netif->addr_hint = addr_hint;
|
|
err = ip_output_if(p, src, dest, ttl, tos, proto, netif);
|
|
netif->addr_hint = NULL;
|
|
|
|
return err;
|
|
}
|
|
#endif /* LWIP_NETIF_HWADDRHINT*/
|
|
|
|
#if IP_DEBUG
|
|
/* Print an IP header by using LWIP_DEBUGF
|
|
* @param p an IP packet, p->payload pointing to the IP header
|
|
*/
|
|
void
|
|
ip_debug_print(struct pbuf *p)
|
|
{
|
|
struct ip_hdr *iphdr = (struct ip_hdr *)p->payload;
|
|
u8_t *payload;
|
|
|
|
payload = (u8_t *)iphdr + IP_HLEN;
|
|
|
|
LWIP_DEBUGF(IP_DEBUG, ("IP header:\n"));
|
|
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
|
LWIP_DEBUGF(IP_DEBUG, ("|%2"S16_F" |%2"S16_F" | 0x%02"X16_F" | %5"U16_F" | (v, hl, tos, len)\n",
|
|
IPH_V(iphdr),
|
|
IPH_HL(iphdr),
|
|
IPH_TOS(iphdr),
|
|
ntohs(IPH_LEN(iphdr))));
|
|
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
|
LWIP_DEBUGF(IP_DEBUG, ("| %5"U16_F" |%"U16_F"%"U16_F"%"U16_F"| %4"U16_F" | (id, flags, offset)\n",
|
|
ntohs(IPH_ID(iphdr)),
|
|
ntohs(IPH_OFFSET(iphdr)) >> 15 & 1,
|
|
ntohs(IPH_OFFSET(iphdr)) >> 14 & 1,
|
|
ntohs(IPH_OFFSET(iphdr)) >> 13 & 1,
|
|
ntohs(IPH_OFFSET(iphdr)) & IP_OFFMASK));
|
|
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
|
LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | 0x%04"X16_F" | (ttl, proto, chksum)\n",
|
|
IPH_TTL(iphdr),
|
|
IPH_PROTO(iphdr),
|
|
ntohs(IPH_CHKSUM(iphdr))));
|
|
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
|
LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (src)\n",
|
|
ip4_addr1_16(&iphdr->src),
|
|
ip4_addr2_16(&iphdr->src),
|
|
ip4_addr3_16(&iphdr->src),
|
|
ip4_addr4_16(&iphdr->src)));
|
|
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
|
LWIP_DEBUGF(IP_DEBUG, ("| %3"U16_F" | %3"U16_F" | %3"U16_F" | %3"U16_F" | (dest)\n",
|
|
ip4_addr1_16(&iphdr->dest),
|
|
ip4_addr2_16(&iphdr->dest),
|
|
ip4_addr3_16(&iphdr->dest),
|
|
ip4_addr4_16(&iphdr->dest)));
|
|
LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n"));
|
|
}
|
|
#endif /* IP_DEBUG */
|