/* * Copyright (c) 2001-2003 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 * * $Id: udp.c,v 1.19 2003/02/10 21:58:34 davidhaas Exp $ */ /*-----------------------------------------------------------------------------------*/ /* udp.c * * The code for the User Datagram Protocol UDP. * */ /*-----------------------------------------------------------------------------------*/ #include "lwip/debug.h" #include "lwip/def.h" #include "lwip/memp.h" #include "lwip/inet.h" #include "lwip/netif.h" #include "lwip/udp.h" #include "lwip/icmp.h" #include "lwip/stats.h" #include "arch/perf.h" #include "lwip/snmp.h" /*-----------------------------------------------------------------------------------*/ /* The list of UDP PCBs. */ #if LWIP_UDP /*static*/ struct udp_pcb *udp_pcbs = NULL; static struct udp_pcb *pcb_cache = NULL; #endif /* LWIP_UDP */ #if UDP_DEBUG int udp_debug_print(struct udp_hdr *udphdr); #endif /* UDP_DEBUG */ /*-----------------------------------------------------------------------------------*/ void udp_init(void) { #if LWIP_UDP udp_pcbs = pcb_cache = NULL; #endif /* LWIP_UDP */ } #if LWIP_UDP /*-----------------------------------------------------------------------------------*/ /* udp_lookup: * * An experimental feature that will be changed in future versions. Do * not depend on it yet... */ /*-----------------------------------------------------------------------------------*/ #ifdef LWIP_DEBUG u8_t udp_lookup(struct ip_hdr *iphdr, struct netif *inp) { struct udp_pcb *pcb; struct udp_hdr *udphdr; u16_t src, dest; PERF_START; (void)inp; udphdr = (struct udp_hdr *)(u8_t *)iphdr + IPH_HL(iphdr) * 4; src = NTOHS(udphdr->src); dest = NTOHS(udphdr->dest); pcb = pcb_cache; if(pcb != NULL && pcb->remote_port == src && pcb->local_port == dest && (ip_addr_isany(&pcb->remote_ip) || ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) && (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { return 1; } else { for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) { if(pcb->remote_port == src && pcb->local_port == dest && (ip_addr_isany(&pcb->remote_ip) || ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) && (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { pcb_cache = pcb; break; } } if(pcb == NULL) { for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) { if(pcb->remote_port == 0 && pcb->local_port == dest && (ip_addr_isany(&pcb->remote_ip) || ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) && (ip_addr_isany(&pcb->local_ip) || ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { break; } } } } PERF_STOP("udp_lookup"); if(pcb != NULL) { return 1; } else { return 1; } } #endif /* LWIP_DEBUG */ /** * Process an incoming UDP datagram. * * Given an incoming UDP datagram (as a chain of pbufs) this function * finds a corresponding UDP PCB and * * @param pbuf pbuf to be demultiplexed to a UDP PCB. * @param netif network interface on which the datagram was received. * * @see udp_disconnect() */ void udp_input(struct pbuf *p, struct netif *inp) { struct udp_hdr *udphdr; struct udp_pcb *pcb; struct ip_hdr *iphdr; u16_t src, dest; PERF_START; #ifdef UDP_STATS ++lwip_stats.udp.recv; #endif /* UDP_STATS */ iphdr = p->payload; pbuf_header(p, -(UDP_HLEN + IPH_HL(iphdr) * 4)); udphdr = (struct udp_hdr *)((u8_t *)p->payload - UDP_HLEN); DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %u\n", p->tot_len)); src = NTOHS(udphdr->src); dest = NTOHS(udphdr->dest); #if UDP_DEBUG udp_debug_print(udphdr); #endif /* UDP_DEBUG */ /* print the UDP source and destination */ DEBUGF(UDP_DEBUG, ("udp (%u.%u.%u.%u, %u) <-- (%u.%u.%u.%u, %u)\n", ip4_addr1(&iphdr->dest), ip4_addr2(&iphdr->dest), ip4_addr3(&iphdr->dest), ip4_addr4(&iphdr->dest), ntohs(udphdr->dest), ip4_addr1(&iphdr->src), ip4_addr2(&iphdr->src), ip4_addr3(&iphdr->src), ip4_addr4(&iphdr->src), ntohs(udphdr->src))); /* Iterate through the UDP pcb list for a fully matching pcb */ for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) { /* print the PCB local and remote address */ DEBUGF(UDP_DEBUG, ("pcb (%u.%u.%u.%u, %u) --- (%u.%u.%u.%u, %u)\n", ip4_addr1(&pcb->local_ip), ip4_addr2(&pcb->local_ip), ip4_addr3(&pcb->local_ip), ip4_addr4(&pcb->local_ip), pcb->local_port, ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip), ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip), pcb->remote_port)); /* PCB remote port matches UDP source port? */ if((pcb->remote_port == src) && /* PCB local port matches UDP destination port? */ (pcb->local_port == dest) && /* accepting from any remote (source) IP address? or... */ (ip_addr_isany(&pcb->remote_ip) || /* PCB remote IP address matches UDP source IP address? */ ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src))) && /* accepting on any local (netif) IP address? or... */ (ip_addr_isany(&pcb->local_ip) || /* PCB local IP address matches UDP destination IP address? */ ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { break; } } /* no fully matching pcb found? then look for an unconnected pcb */ if (pcb == NULL) { /* Iterate through the UDP PCB list for a pcb that matches the local address. */ for(pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) { DEBUGF(UDP_DEBUG, ("pcb (%u.%u.%u.%u, %u) --- (%u.%u.%u.%u, %u)\n", ip4_addr1(&pcb->local_ip), ip4_addr2(&pcb->local_ip), ip4_addr3(&pcb->local_ip), ip4_addr4(&pcb->local_ip), pcb->local_port, ip4_addr1(&pcb->remote_ip), ip4_addr2(&pcb->remote_ip), ip4_addr3(&pcb->remote_ip), ip4_addr4(&pcb->remote_ip), pcb->remote_port)); /* unconnected? */ if(((pcb->flags & UDP_FLAGS_CONNECTED) == 0) && /* destination port matches? */ (pcb->local_port == dest) && /* not bound to a specific (local) interface address? or... */ (ip_addr_isany(&pcb->local_ip) || /* ...matching interface address? */ ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)))) { break; } } } /* Check checksum if this is a match or if it was directed at us. */ if(pcb != NULL || ip_addr_cmp(&inp->ip_addr, &iphdr->dest)) { DEBUGF(UDP_DEBUG, ("udp_input: calculating checksum\n")); pbuf_header(p, UDP_HLEN); #ifdef IPv6 if(iphdr->nexthdr == IP_PROTO_UDPLITE) { #else if(IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) { #endif /* IPv4 */ /* Do the UDP Lite checksum */ if(inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src), (struct ip_addr *)&(iphdr->dest), IP_PROTO_UDPLITE, ntohs(udphdr->len)) != 0) { DEBUGF(UDP_DEBUG, ("udp_input: UDP Lite datagram discarded due to failing checksum\n")); #ifdef UDP_STATS ++lwip_stats.udp.chkerr; ++lwip_stats.udp.drop; #endif /* UDP_STATS */ snmp_inc_udpinerrors(); pbuf_free(p); goto end; } } else { if(udphdr->chksum != 0) { if(inet_chksum_pseudo(p, (struct ip_addr *)&(iphdr->src), (struct ip_addr *)&(iphdr->dest), IP_PROTO_UDP, p->tot_len) != 0) { DEBUGF(UDP_DEBUG, ("udp_input: UDP datagram discarded due to failing checksum\n")); #ifdef UDP_STATS ++lwip_stats.udp.chkerr; ++lwip_stats.udp.drop; #endif /* UDP_STATS */ snmp_inc_udpinerrors(); pbuf_free(p); goto end; } } } pbuf_header(p, -UDP_HLEN); if(pcb != NULL) { snmp_inc_udpindatagrams(); pcb->recv(pcb->recv_arg, pcb, p, &(iphdr->src), src); } else { DEBUGF(UDP_DEBUG, ("udp_input: not for us.\n")); /* No match was found, send ICMP destination port unreachable unless destination address was broadcast/multicast. */ if(!ip_addr_isbroadcast(&iphdr->dest, &inp->netmask) && !ip_addr_ismulticast(&iphdr->dest)) { /* adjust pbuf pointer */ p->payload = iphdr; icmp_dest_unreach(p, ICMP_DUR_PORT); } #ifdef UDP_STATS ++lwip_stats.udp.proterr; ++lwip_stats.udp.drop; #endif /* UDP_STATS */ snmp_inc_udpnoports(); pbuf_free(p); } } else { pbuf_free(p); } end: PERF_STOP("udp_input"); } /** * Send data using UDP. * * @param pcb UDP PCB used to send the data. * @param pbuf chain of pbuf's to be sent. * * @return lwIP error code. * - ERR_OK. Successful. No error occured. * - ERR_MEM. Out of memory. * - ERR_USE. The specified ipaddr and port are already bound to by * another UDP PCB. * * @see udp_disconnect() */ err_t udp_send(struct udp_pcb *pcb, struct pbuf *p) { struct udp_hdr *udphdr; struct netif *netif; struct ip_addr *src_ip; err_t err; struct pbuf *hdr; DEBUGF(UDP_DEBUG, ("udp_send\n")); if(pcb->local_port == 0) { err = udp_bind(pcb, &pcb->local_ip, pcb->local_port); if(err != ERR_OK) return err; } /* hdr will point to the UDP header pbuf if an extra header pbuf has to be allocated. */ hdr = NULL; /* succeeding in adding an UDP header to first given pbuf in chain? */ if(pbuf_header(p, UDP_HLEN)) { /* allocate header in new pbuf */ hdr = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM); /* new header pbuf could not be allocated? */ if(hdr == NULL) { return ERR_MEM; } /* chain header in front of given pbuf */ pbuf_chain(hdr, p); /* have p point to header pbuf */ p = hdr; } DEBUGF(UDP_DEBUG, ("udp_send: got pbuf\n")); udphdr = p->payload; udphdr->src = htons(pcb->local_port); udphdr->dest = htons(pcb->remote_port); udphdr->chksum = 0x0000; if((netif = ip_route(&(pcb->remote_ip))) == NULL) { DEBUGF(UDP_DEBUG, ("udp_send: No route to 0x%lx\n", pcb->remote_ip.addr)); #ifdef UDP_STATS ++lwip_stats.udp.rterr; #endif /* UDP_STATS */ return ERR_RTE; } /* using IP_ANY_ADDR? */ if(ip_addr_isany(&pcb->local_ip)) { /* use network interface IP address as source address */ src_ip = &(netif->ip_addr); } else { /* use UDP PCB local IP address as source address */ src_ip = &(pcb->local_ip); } DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %u\n", p->tot_len)); /* UDP Lite protocol? */ if(pcb->flags & UDP_FLAGS_UDPLITE) { DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %u\n", p->tot_len)); /* set UDP message length in UDP header */ udphdr->len = htons(pcb->chksum_len); /* calculate checksum */ udphdr->chksum = inet_chksum_pseudo(p, src_ip, &(pcb->remote_ip), IP_PROTO_UDP, pcb->chksum_len); /* chksum zero must become 0xffff, as zero means 'no checksum' */ if(udphdr->chksum == 0x0000) udphdr->chksum = 0xffff; /* output to IP */ err = ip_output_if(p, src_ip, &pcb->remote_ip, UDP_TTL, IP_PROTO_UDPLITE, netif); snmp_inc_udpoutdatagrams(); } else { DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %u\n", p->tot_len)); udphdr->len = htons(p->tot_len); /* calculate checksum */ if((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) { udphdr->chksum = inet_chksum_pseudo(p, src_ip, &pcb->remote_ip, IP_PROTO_UDP, p->tot_len); /* chksum zero must become 0xffff, as zero means 'no checksum' */ if(udphdr->chksum == 0x0000) udphdr->chksum = 0xffff; } DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum %x\n", udphdr->chksum)); snmp_inc_udpoutdatagrams(); DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if(,,,,IP_PROTO_UDP,)\n")); /* output to IP */ err = ip_output_if(p, src_ip, &pcb->remote_ip, UDP_TTL, IP_PROTO_UDP, netif); } /* dechain and free the header pbuf */ if(hdr != NULL) { pbuf_dechain(hdr); pbuf_free(hdr); } #ifdef UDP_STATS ++lwip_stats.udp.xmit; #endif /* UDP_STATS */ return err; } /** * Bind an UDP PCB. * * @param pcb UDP PCB to be bound with a local address ipaddr and port. * @param ipaddr local IP address to bind with. Use IP_ADDR_ANY to * bind to all local interfaces. * @param port local UDP port to bind with. * * @return lwIP error code. * - ERR_OK. Successful. No error occured. * - ERR_USE. The specified ipaddr and port are already bound to by * another UDP PCB. * * @see udp_disconnect() */ err_t udp_bind(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) { struct udp_pcb *ipcb; u8_t rebind = 0; /* Check for double bind and rebind of the same pcb */ for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) { /* is this UDP PCB already on active list? */ if (pcb == ipcb) { rebind = 1; } /* port matches that of PCB in list? */ if ((ipcb->local_port == port) && /* IP address matches, or one is IP_ADDR_ANY? */ (ip_addr_isany(&(ipcb->local_ip)) || ip_addr_isany(ipaddr) || ip_addr_cmp(&(ipcb->local_ip), ipaddr))) { /* other PCB already binds to this local IP and port */ return ERR_USE; } } /* bind local address */ ip_addr_set(&pcb->local_ip, ipaddr); if(port == 0) { #ifndef UDP_LOCAL_PORT_RANGE_START #define UDP_LOCAL_PORT_RANGE_START 4096 #define UDP_LOCAL_PORT_RANGE_END 0x7fff #endif port = UDP_LOCAL_PORT_RANGE_START; ipcb = udp_pcbs; while((ipcb != NULL) && (port != UDP_LOCAL_PORT_RANGE_END)) { if(ipcb->local_port == port) { port++; ipcb = udp_pcbs; } else ipcb = ipcb->next; } if(ipcb) /* no more ports available in local range */ return ERR_USE; } pcb->local_port = port; /* We need to place the PCB on the list if not already there. */ if (rebind == 0) { pcb->next = udp_pcbs; udp_pcbs = pcb; } DEBUGF(UDP_DEBUG, ("udp_bind: bound to port %u\n", port)); return ERR_OK; } /** * Connect an UDP PCB. * * @param pcb UDP PCB to be connected with remote address ipaddr and port. * @param ipaddr remote IP address to connect with. * @param port remote UDP port to connect with. * * @return lwIP error code * * @see udp_disconnect() */ err_t udp_connect(struct udp_pcb *pcb, struct ip_addr *ipaddr, u16_t port) { struct udp_pcb *ipcb; if(pcb->local_port == 0) { err_t err = udp_bind(pcb, &pcb->local_ip, pcb->local_port); if(err != ERR_OK) return err; } ip_addr_set(&pcb->remote_ip, ipaddr); pcb->remote_port = port; #if 1 pcb->flags |= UDP_FLAGS_CONNECTED; /* Nail down local IP for netconn_addr()/getsockname() */ if(ip_addr_isany(&pcb->local_ip) && !ip_addr_isany(&pcb->remote_ip)) { struct netif *netif; if((netif = ip_route(&(pcb->remote_ip))) == NULL) { DEBUGF(UDP_DEBUG, ("udp_connect: No route to 0x%lx\n", pcb->remote_ip.addr)); #ifdef UDP_STATS ++lwip_stats.udp.rterr; #endif /* UDP_STATS */ return ERR_RTE; } pcb->local_ip = netif->ip_addr; } else if(ip_addr_isany(&pcb->remote_ip)) { pcb->local_ip.addr = 0; } #endif /* Insert UDP PCB into the list of active UDP PCBs. */ for(ipcb = udp_pcbs; ipcb != NULL; ipcb = ipcb->next) { if(pcb == ipcb) { /* already on the list, just return */ return ERR_OK; } } /* PCB not yet on the list, add PCB now */ pcb->next = udp_pcbs; udp_pcbs = pcb; return ERR_OK; } void udp_disconnect(struct udp_pcb *pcb) { pcb->flags &= ~UDP_FLAGS_CONNECTED; } /*-----------------------------------------------------------------------------------*/ void udp_recv(struct udp_pcb *pcb, void (* recv)(void *arg, struct udp_pcb *upcb, struct pbuf *p, struct ip_addr *addr, u16_t port), void *recv_arg) { /* remember recv() callback and user data */ pcb->recv = recv; pcb->recv_arg = recv_arg; } /** * Remove an UDP PCB. * * @param pcb UDP PCB to be removed. The PCB is removed from the list of * UDP PCB's and the data structure is freed from memory. * * @see udp_new() */ void udp_remove(struct udp_pcb *pcb) { struct udp_pcb *pcb2; /* pcb to be removed is first in list? */ if (udp_pcbs == pcb) { /* make list start at 2nd pcb */ udp_pcbs = udp_pcbs->next; /* pcb not 1st in list */ } else for(pcb2 = udp_pcbs; pcb2 != NULL; pcb2 = pcb2->next) { /* find pcb in udp_pcbs list */ if(pcb2->next != NULL && pcb2->next == pcb) { /* remove pcb from list */ pcb2->next = pcb->next; } } memp_free(MEMP_UDP_PCB, pcb); } /** * Create a UDP PCB. * * @return The UDP PCB which was created. NULL if the PCB data structure * could not be allocated. * * @see udp_remove() */ struct udp_pcb * udp_new(void) { struct udp_pcb *pcb; pcb = memp_malloc(MEMP_UDP_PCB); /* could allocate UDP PCB? */ if(pcb != NULL) { /* initialize PCB to all zeroes */ memset(pcb, 0, sizeof(struct udp_pcb)); } return pcb; } /*-----------------------------------------------------------------------------------*/ #if UDP_DEBUG int udp_debug_print(struct udp_hdr *udphdr) { DEBUGF(UDP_DEBUG, ("UDP header:\n")); DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); DEBUGF(UDP_DEBUG, ("| %5u | %5u | (src port, dest port)\n", ntohs(udphdr->src), ntohs(udphdr->dest))); DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); DEBUGF(UDP_DEBUG, ("| %5u | 0x%04x | (len, chksum)\n", ntohs(udphdr->len), ntohs(udphdr->chksum))); DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); return 0; } #endif /* UDP_DEBUG */ /*-----------------------------------------------------------------------------------*/ #endif /* LWIP_UDP */