/** * 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; }
/* * Validate a TCP segment's checksum,return TRUE if pass the validation, * FALSE will be returned otherwise. */ static BOOL validateTCPChksum(struct ip_hdr* p, struct pbuf* pb) { struct tcp_hdr* pTcpHdr = NULL; int iph_len = IPH_HL(p); int ip_len = ntohs(IPH_LEN(p)); /* Total IP packet length. */ int chksum_old = 0, chksum_new = 0; ip_addr_t src, dest; iph_len *= 4; /* Locate TCP header. */ pTcpHdr = (struct tcp_hdr*)((char*)p + iph_len); /* Validate pbuf object. */ if (pb->tot_len < (iph_len + sizeof(struct tcp_hdr))) { return FALSE; } /* Validate the length of this packet. */ if (ip_len < (iph_len + sizeof(struct tcp_hdr))) { return FALSE; } /* * Preserve TCP segment's check sum value before re-calculate * the value. */ chksum_old = pTcpHdr->chksum; ip_addr_copy(src, p->src); ip_addr_copy(dest, p->dest); pbuf_header(pb, -iph_len); /* move to TCP header. */ pTcpHdr->chksum = 0; /* Reset the original check sum. */ /* Recalculate the segment's checksum value. */ chksum_new = inet_chksum_pseudo(pb, &src, &dest, IP_PROTO_TCP, /* IP payload length,e.i,TCP header plus data. */ ip_len - iph_len); //pb->tot_len); pbuf_header(pb, iph_len); /* move back. */ if (chksum_new != chksum_old) { __LOG("TCP checksum fail:ip_len = %d,pbuf_tot_len = %d,src_addr:%s\r\n", ip_len, pb->tot_len, inet_ntoa(p->src.addr)); IP_STATS_INC(tcp.chkerr); IP_STATS_INC(tcp.drop); return FALSE; } return TRUE; }
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)); }
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); }
struct netif * ip_router(ip_addr_t *dest, ip_addr_t *source){ 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_is_up(netif)) { if (ip_addr_netcmp(source, &(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 %"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); snmp_inc_ipoutnoroutes(); return NULL; } /* no matching netif found, use default netif */ return netif_default; }
err_t ip6_output(struct pbuf *p, struct ip6_addr *src, struct ip6_addr *dest, u8_t ttl, u8_t proto) { struct netif *netif; if ((netif = ip6_route(dest)) == NULL) { LWIP_DEBUGF(IP_DEBUG, ("ip6_output: No route to dest\n"));IP_STATS_INC(ip.rterr); return ERR_RTE; } return ip6_output_if(p, src, dest, ttl, proto, netif); }
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 | 2, ("ip_output: No route to 0x%"X32_F"\n", dest->addr)); IP_STATS_INC(ip.rterr); snmp_inc_ipoutnoroutes(); return ERR_RTE; } return ip_output_if(p, src, dest, ttl, tos, proto, netif); }
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; }
/** * 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 | 2, ("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; }
/** * 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")); }
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) { struct ip_hdr *iphdr; static u16_t ip_id = 0; snmp_inc_ipoutrequests(); if (dest != IP_HDRINCL) { if (pbuf_header(p, IP_HLEN)) { LWIP_DEBUGF(IP_DEBUG | 2, ("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; 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, htons(IP_DF)); 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 { iphdr = p->payload; dest = &(iphdr->dest); } #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_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); LWIP_DEBUGF(IP_DEBUG, ("netif->output()")); return netif->output(netif, p, dest); }
err_t ip_input(struct pbuf *p, struct netif *inp) { struct ip_hdr *iphdr; struct netif *netif; u16_t iphdrlen; IP_STATS_INC(ip.recv); snmp_inc_ipinreceives(); /* identify the IP header */ iphdr = p->payload; if (IPH_V(iphdr) != 4) { LWIP_DEBUGF(IP_DEBUG | 1, ("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 */ iphdrlen = IPH_HL(iphdr); /* calculate IP header length in bytes */ iphdrlen *= 4; /* header length exceeds first pbuf length? */ if (iphdrlen > p->len) { LWIP_DEBUGF(IP_DEBUG | 2, ("IP header (len %"U16_F") does not fit in first pbuf (len %"U16_F"), IP packet droppped.\n", iphdrlen, p->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, iphdrlen) != 0) { LWIP_DEBUGF(IP_DEBUG | 2, ("Checksum (0x%"X16_F") failed, IP packet dropped.\n", inet_chksum(iphdr, iphdrlen))); 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, ntohs(IPH_LEN(iphdr))); /* match packet against an interface, i.e. is this packet for us? */ for (netif = netif_list; netif != NULL; netif = netif->next) { 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 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 | DBG_TRACE | 1, ("ip_input: UDP packet to DHCP client port %"U16_F"\n", ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdrlen))->dest))); if (ntohs(((struct udp_hdr *)((u8_t *)iphdr + iphdrlen))->dest) == DHCP_CLIENT_PORT) { LWIP_DEBUGF(IP_DEBUG | DBG_TRACE | 1, ("ip_input: DHCP packet accepted.\n")); netif = inp; } } } #endif /* LWIP_DHCP */ /* packet not for us? */ if (netif == NULL) { /* packet not for us, route or discard */ LWIP_DEBUGF(IP_DEBUG | DBG_TRACE | 1, ("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 | 2, ("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 == 0 /* no support for IP options in the IP header? */ if (iphdrlen > IP_HLEN) { LWIP_DEBUGF(IP_DEBUG | 2, ("IP packet dropped since there were IP options (while IP_OPTIONS == 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 == 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)); #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: case IP_PROTO_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 */ case IP_PROTO_ICMP: snmp_inc_ipindelivers(); icmp_input(p, inp); break; default: /* 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); } pbuf_free(p); LWIP_DEBUGF(IP_DEBUG | 2, ("Unsupported transport protocol %"U16_F"\n", IPH_PROTO(iphdr))); IP_STATS_INC(ip.proterr); IP_STATS_INC(ip.drop); snmp_inc_ipinunknownprotos(); } #if LWIP_RAW } /* LWIP_RAW */ #endif return ERR_OK; }
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"); }
void ip6_input(struct pbuf *p, struct netif *inp) { struct ip6_hdr *iphdr; struct netif *netif; PERF_START; #if IP_DEBUG ip6_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 ip6_debug_print(p); #endif /* IP_DEBUG */ pbuf_free(p); IP_STATS_INC(ip.err);IP_STATS_INC(ip.drop); return; } char forus = 0; /* 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 ")); ip6_addr_debug_print(IP_DEBUG, ((struct ip6_addr *)&(iphdr->dest))); LWIP_DEBUGF(IP_DEBUG, ("netif->ip6_addr ")); ip6_addr_debug_print(IP_DEBUG, ((struct ip6_addr *)&(netif->ip6_addr))); LWIP_DEBUGF(IP_DEBUG, ("\n\r")); #endif /* IP_DEBUG */ if (ip6_addr_cmp(&(iphdr->dest), &(netif->ip6_addr))) { forus = 1; LWIP_DEBUGF(IP_DEBUG, ("ip6_input: packet for us: perfect match")); break; } if (ip6_addr_issolicitedmulticast(&(iphdr->dest), &(netif->ip6_addr))) { forus = 1; LWIP_DEBUGF(IP_DEBUG, ("ip6_input: packet for us on solicited multicast address\n")); break; } } // check if it is a multicast address and we are listening on that address if (ip6_addr_isallnodes(&(iphdr->dest))) forus = 1; if (forus == 0) { /* packet not for us, route or discard */ LWIP_DEBUGF(IP_DEBUG, ("ip6_input: packet not for us.\n")); #if IP_FORWARD ip6_forward(p, iphdr); #endif pbuf_free(p); return; } pbuf_realloc(p, IP6_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, -IP6_HLEN)) { LWIP_ASSERT("Can't move over header in packet", 0); return; }*/ switch (iphdr->nexthdr) { #if LWIP_UDP case IP6_PROTO_UDP: udp_input(p, inp); break; #endif #if LWIP_TCP case IP6_PROTO_TCP: tcp_input(p, inp); break; #endif #if LWIP_ICMP case IP6_PROTO_ICMP: icmp6_input(p, inp); break; #endif /* LWIP_ICMP */ default: #if LWIP_ICMP /* send ICMP destination protocol unreachable */ icmp6_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"); }