| /** |
| * @file |
| * This is the IPv4 layer implementation for incoming and outgoing IP traffic. |
| * |
| * @see ip_frag.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 <adam@sics.se> |
| * |
| */ |
| |
| #include "lwip/opt.h" |
| #include "lwip/ip.h" |
| #include "lwip/def.h" |
| #include "lwip/mem.h" |
| #include "lwip/ip_frag.h" |
| #include "lwip/inet.h" |
| #include "lwip/inet_chksum.h" |
| #include "lwip/netif.h" |
| #include "lwip/icmp.h" |
| #include "lwip/igmp.h" |
| #include "lwip/raw.h" |
| #include "lwip/udp.h" |
| #include "lwip/tcp.h" |
| #include "lwip/snmp.h" |
| #include "lwip/dhcp.h" |
| #include "lwip/stats.h" |
| #include "arch/perf.h" |
| |
| #include <string.h> |
| |
| /** |
| * The interface that provided the packet for the current callback |
| * invocation. |
| */ |
| struct netif *current_netif; |
| |
| /** |
| * Header of the input packet currently being processed. |
| */ |
| const struct ip_hdr *current_header; |
| |
| /** |
| * 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. |
| * |
| * @param dest the destination IP address for which to find the route |
| * @return the netif on which to send to reach dest |
| */ |
| struct netif * |
| ip_route(struct ip_addr *dest) |
| { |
| struct netif *netif; |
| |
| /* iterate through netifs */ |
| for(netif = netif_list; netif != NULL; netif = netif->next) { |
| /* network mask matches? */ |
| if (netif_is_up(netif)) { |
| if (ip_addr_netcmp(dest, &(netif->ip_addr), &(netif->netmask))) { |
| /* return netif on which to forward IP packet */ |
| return netif; |
| } |
| } |
| } |
| if ((netif_default == NULL) || (!netif_is_up(netif_default))) { |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("ip_route: No route to 0x%"X32_F"\n", dest->addr)); |
| IP_STATS_INC(ip.rterr); |
| snmp_inc_ipoutnoroutes(); |
| return NULL; |
| } |
| /* no matching netif found, use default netif */ |
| return netif_default; |
| } |
| |
| #if 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. |
| * |
| * @param p the packet to forward (p->payload points to IP header) |
| * @param iphdr the IP header of the input packet |
| * @param inp the netif on which this packet was received |
| * @return the netif on which the packet was sent (NULL if it wasn't sent) |
| */ |
| static struct netif * |
| ip_forward(struct pbuf *p, struct ip_hdr *iphdr, struct netif *inp) |
| { |
| struct netif *netif; |
| |
| PERF_START; |
| /* Find network interface where to forward this IP packet to. */ |
| netif = ip_route((struct ip_addr *)&(iphdr->dest)); |
| if (netif == NULL) { |
| LWIP_DEBUGF(IP_DEBUG, ("ip_forward: no forwarding route for 0x%"X32_F" found\n", |
| iphdr->dest.addr)); |
| snmp_inc_ipoutnoroutes(); |
| return (struct netif *)NULL; |
| } |
| /* Do not forward packets onto the same network interface on which |
| * they arrived. */ |
| if (netif == inp) { |
| LWIP_DEBUGF(IP_DEBUG, ("ip_forward: not bouncing packets back on incoming interface.\n")); |
| snmp_inc_ipoutnoroutes(); |
| return (struct netif *)NULL; |
| } |
| |
| /* decrement TTL */ |
| IPH_TTL_SET(iphdr, IPH_TTL(iphdr) - 1); |
| /* send ICMP if TTL == 0 */ |
| if (IPH_TTL(iphdr) == 0) { |
| snmp_inc_ipinhdrerrors(); |
| #if LWIP_ICMP |
| /* Don't send ICMP messages in response to ICMP messages */ |
| if (IPH_PROTO(iphdr) != IP_PROTO_ICMP) { |
| icmp_time_exceeded(p, ICMP_TE_TTL); |
| } |
| #endif /* LWIP_ICMP */ |
| return (struct netif *)NULL; |
| } |
| |
| /* Incrementally update the IP checksum. */ |
| if (IPH_CHKSUM(iphdr) >= htons(0xffff - 0x100)) { |
| IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100) + 1); |
| } else { |
| IPH_CHKSUM_SET(iphdr, IPH_CHKSUM(iphdr) + htons(0x100)); |
| } |
| |
| LWIP_DEBUGF(IP_DEBUG, ("ip_forward: forwarding packet to 0x%"X32_F"\n", |
| iphdr->dest.addr)); |
| |
| IP_STATS_INC(ip.fw); |
| IP_STATS_INC(ip.xmit); |
| snmp_inc_ipforwdatagrams(); |
| |
| PERF_STOP("ip_forward"); |
| /* transmit pbuf on chosen interface */ |
| netif->output(netif, p, (struct ip_addr *)&(iphdr->dest)); |
| return netif; |
| } |
| #endif /* IP_FORWARD */ |
| |
| /** |
| * 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. |
| * |
| * @param p the received IP packet (p->payload points to IP header) |
| * @param inp the netif on which this packet was received |
| * @return ERR_OK if the packet was processed (could return ERR_* if it wasn't |
| * processed, but currently always returns ERR_OK) |
| */ |
| err_t |
| ip_input(struct pbuf *p, struct netif *inp) |
| { |
| struct ip_hdr *iphdr; |
| struct netif *netif; |
| u16_t iphdr_hlen; |
| u16_t iphdr_len; |
| #if LWIP_DHCP |
| int check_ip_src=1; |
| #endif /* LWIP_DHCP */ |
| |
| IP_STATS_INC(ip.recv); |
| snmp_inc_ipinreceives(); |
| |
| /* identify the IP header */ |
| iphdr = p->payload; |
| if (IPH_V(iphdr) != 4) { |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_WARNING, ("IP packet dropped due to bad version number %"U16_F"\n", IPH_V(iphdr))); |
| ip_debug_print(p); |
| pbuf_free(p); |
| IP_STATS_INC(ip.err); |
| IP_STATS_INC(ip.drop); |
| snmp_inc_ipinhdrerrors(); |
| return ERR_OK; |
| } |
| |
| /* obtain IP header length in number of 32-bit words */ |
| iphdr_hlen = IPH_HL(iphdr); |
| /* calculate IP header length in bytes */ |
| iphdr_hlen *= 4; |
| /* obtain ip length in bytes */ |
| iphdr_len = ntohs(IPH_LEN(iphdr)); |
| |
| /* header length exceeds first pbuf length, or ip length exceeds total pbuf length? */ |
| if ((iphdr_hlen > p->len) || (iphdr_len > p->tot_len)) { |
| if (iphdr_hlen > p->len) { |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, |
| ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet dropped.\n", |
| iphdr_hlen, p->len)); |
| } |
| if (iphdr_len > p->tot_len) { |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, |
| ("IP (len %"U16_F") is longer than pbuf (len %"U16_F"), IP packet dropped.\n", |
| iphdr_len, p->tot_len)); |
| } |
| /* free (drop) packet pbufs */ |
| pbuf_free(p); |
| IP_STATS_INC(ip.lenerr); |
| IP_STATS_INC(ip.drop); |
| snmp_inc_ipindiscards(); |
| return ERR_OK; |
| } |
| |
| /* verify checksum */ |
| #if CHECKSUM_CHECK_IP |
| if (inet_chksum(iphdr, iphdr_hlen) != 0) { |
| |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, |
| ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdr_hlen))); |
| ip_debug_print(p); |
| pbuf_free(p); |
| IP_STATS_INC(ip.chkerr); |
| IP_STATS_INC(ip.drop); |
| snmp_inc_ipinhdrerrors(); |
| return ERR_OK; |
| } |
| #endif |
| |
| /* Trim pbuf. This should have been done at the netif layer, |
| * but we'll do it anyway just to be sure that its done. */ |
| pbuf_realloc(p, iphdr_len); |
| |
| /* match packet against an interface, i.e. is this packet for us? */ |
| #if LWIP_IGMP |
| if (ip_addr_ismulticast(&(iphdr->dest))) { |
| if ((inp->flags & NETIF_FLAG_IGMP) && (igmp_lookfor_group(inp, &(iphdr->dest)))) { |
| netif = inp; |
| } else { |
| netif = NULL; |
| } |
| } else |
| #endif /* LWIP_IGMP */ |
| { |
| /* start trying with inp. if that's not acceptable, start walking the |
| list of configured netifs. |
| 'first' is used as a boolean to mark whether we started walking the list */ |
| int first = 1; |
| netif = inp; |
| do { |
| 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", |
| iphdr->dest.addr, netif->ip_addr.addr, |
| iphdr->dest.addr & netif->netmask.addr, |
| netif->ip_addr.addr & netif->netmask.addr, |
| iphdr->dest.addr & ~(netif->netmask.addr))); |
| |
| /* interface is up and configured? */ |
| if ((netif_is_up(netif)) && (!ip_addr_isany(&(netif->ip_addr)))) { |
| /* unicast to this interface address? */ |
| if (ip_addr_cmp(&(iphdr->dest), &(netif->ip_addr)) || |
| /* or broadcast on this interface network address? */ |
| ip_addr_isbroadcast(&(iphdr->dest), netif)) { |
| LWIP_DEBUGF(IP_DEBUG, ("ip_input: packet accepted on interface %c%c\n", |
| netif->name[0], netif->name[1])); |
| /* break out of for loop */ |
| break; |
| } |
| } |
| if (first) { |
| first = 0; |
| netif = netif_list; |
| } else { |
| netif = netif->next; |
| } |
| if (netif == inp) { |
| netif = netif->next; |
| } |
| } while(netif != NULL); |
| } |
| |
| #if LWIP_DHCP |
| /* Pass DHCP messages regardless of destination address. DHCP traffic is addressed |
| * using link layer addressing (such as Ethernet MAC) so we must not filter on IP. |
| * According to RFC 1542 section 3.1.1, referred by RFC 2131). |
| */ |
| if (netif == NULL) { |
| /* remote port is DHCP server? */ |
| if (IPH_PROTO(iphdr) == IP_PROTO_UDP) { |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: UDP packet to DHCP client port %"U16_F"\n", |
| ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest))); |
| if (ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdr_hlen))->dest) == DHCP_CLIENT_PORT) { |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: DHCP packet accepted.\n")); |
| netif = inp; |
| check_ip_src = 0; |
| } |
| } |
| } |
| #endif /* LWIP_DHCP */ |
| |
| /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */ |
| #if LWIP_DHCP |
| /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */ |
| if (check_ip_src && (iphdr->src.addr != 0)) |
| #endif /* LWIP_DHCP */ |
| { if ((ip_addr_isbroadcast(&(iphdr->src), inp)) || |
| (ip_addr_ismulticast(&(iphdr->src)))) { |
| /* packet source is not valid */ |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_WARNING, ("ip_input: packet source is not valid.\n")); |
| /* free (drop) packet pbufs */ |
| pbuf_free(p); |
| IP_STATS_INC(ip.drop); |
| snmp_inc_ipinaddrerrors(); |
| snmp_inc_ipindiscards(); |
| return ERR_OK; |
| } |
| } |
| |
| /* packet not for us? */ |
| if (netif == NULL) { |
| /* packet not for us, route or discard */ |
| LWIP_DEBUGF(IP_DEBUG | LWIP_DBG_TRACE, ("ip_input: packet not for us.\n")); |
| #if IP_FORWARD |
| /* non-broadcast packet? */ |
| if (!ip_addr_isbroadcast(&(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) & 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) & 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 = 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,&(iphdr->dest)); |
| break; |
| #endif /* LWIP_IGMP */ |
| default: |
| #if LWIP_ICMP |
| /* send ICMP destination protocol unreachable unless is was a broadcast */ |
| if (!ip_addr_isbroadcast(&(iphdr->dest), inp) && |
| !ip_addr_ismulticast(&(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; |
| |
| 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, struct ip_addr *src, struct ip_addr *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, struct ip_addr *src, struct ip_addr *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; |
| static u16_t ip_id = 0; |
| |
| 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) { |
| /* 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); |
| } |
| } |
| #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 = 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); |
| |
| ip_addr_set(&(iphdr->dest), dest); |
| |
| IPH_VHLTOS_SET(iphdr, 4, ip_hlen / 4, tos); |
| IPH_LEN_SET(iphdr, htons(p->tot_len)); |
| IPH_OFFSET_SET(iphdr, 0); |
| IPH_ID_SET(iphdr, htons(ip_id)); |
| ++ip_id; |
| |
| if (ip_addr_isany(src)) { |
| ip_addr_set(&(iphdr->src), &(netif->ip_addr)); |
| } else { |
| ip_addr_set(&(iphdr->src), src); |
| } |
| |
| IPH_CHKSUM_SET(iphdr, 0); |
| #if CHECKSUM_GEN_IP |
| IPH_CHKSUM_SET(iphdr, inet_chksum(iphdr, ip_hlen)); |
| #endif |
| } else { |
| /* IP header already included in p */ |
| iphdr = p->payload; |
| dest = &(iphdr->dest); |
| } |
| |
| 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); |
| } |
| #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 |
| |
| 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, struct ip_addr *src, struct ip_addr *dest, |
| u8_t ttl, u8_t tos, 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, 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, struct ip_addr *src, struct ip_addr *dest, |
| u8_t ttl, u8_t tos, u8_t proto, u8_t *addr_hint) |
| { |
| struct netif *netif; |
| err_t err; |
| |
| 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; |
| } |
| |
| 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 = 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(&iphdr->src), |
| ip4_addr2(&iphdr->src), |
| ip4_addr3(&iphdr->src), |
| ip4_addr4(&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(&iphdr->dest), |
| ip4_addr2(&iphdr->dest), |
| ip4_addr3(&iphdr->dest), |
| ip4_addr4(&iphdr->dest))); |
| LWIP_DEBUGF(IP_DEBUG, ("+-------------------------------+\n")); |
| } |
| #endif /* IP_DEBUG */ |
