| /** |
| * @file |
| * User Datagram Protocol module |
| * |
| */ |
| |
| /* |
| * 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> |
| * |
| */ |
| |
| |
| /* udp.c |
| * |
| * The code for the User Datagram Protocol UDP & UDPLite (RFC 3828). |
| * |
| */ |
| |
| /* @todo Check the use of '(struct udp_pcb).chksum_len_rx'! |
| */ |
| |
| #include "lwip/opt.h" |
| |
| #if LWIP_UDP /* don't build if not configured for use in lwipopts.h */ |
| |
| #include "lwip/udp.h" |
| #include "lwip/def.h" |
| #include "lwip/memp.h" |
| #include "lwip/inet.h" |
| #include "lwip/inet_chksum.h" |
| #include "lwip/ip_addr.h" |
| #include "lwip/netif.h" |
| #include "lwip/icmp.h" |
| #include "lwip/stats.h" |
| #include "lwip/snmp.h" |
| #include "arch/perf.h" |
| #include "lwip/dhcp.h" |
| |
| #include <string.h> |
| |
| /* The list of UDP PCBs */ |
| /* exported in udp.h (was static) */ |
| struct udp_pcb *udp_pcbs; |
| |
| /** |
| * Process an incoming UDP datagram. |
| * |
| * Given an incoming UDP datagram (as a chain of pbufs) this function |
| * finds a corresponding UDP PCB and hands over the pbuf to the pcbs |
| * recv function. If no pcb is found or the datagram is incorrect, the |
| * pbuf is freed. |
| * |
| * @param p pbuf to be demultiplexed to a UDP PCB. |
| * @param inp network interface on which the datagram was received. |
| * |
| */ |
| void |
| udp_input(struct pbuf *p, struct netif *inp) |
| { |
| struct udp_hdr *udphdr; |
| struct udp_pcb *pcb, *prev; |
| struct udp_pcb *uncon_pcb; |
| struct ip_hdr *iphdr; |
| u16_t src, dest; |
| u8_t local_match; |
| u8_t broadcast; |
| |
| PERF_START; |
| |
| UDP_STATS_INC(udp.recv); |
| |
| iphdr = p->payload; |
| |
| /* Check minimum length (IP header + UDP header) |
| * and move payload pointer to UDP header */ |
| if (p->tot_len < (IPH_HL(iphdr) * 4 + UDP_HLEN) || pbuf_header(p, -(s16_t)(IPH_HL(iphdr) * 4))) { |
| /* drop short packets */ |
| LWIP_DEBUGF(UDP_DEBUG, |
| ("udp_input: short UDP datagram (%"U16_F" bytes) discarded\n", p->tot_len)); |
| UDP_STATS_INC(udp.lenerr); |
| UDP_STATS_INC(udp.drop); |
| snmp_inc_udpinerrors(); |
| pbuf_free(p); |
| goto end; |
| } |
| |
| udphdr = (struct udp_hdr *)p->payload; |
| |
| /* is broadcast packet ? */ |
| broadcast = ip_addr_isbroadcast(&(iphdr->dest), inp); |
| |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_input: received datagram of length %"U16_F"\n", p->tot_len)); |
| |
| /* convert src and dest ports to host byte order */ |
| src = ntohs(udphdr->src); |
| dest = ntohs(udphdr->dest); |
| |
| udp_debug_print(udphdr); |
| |
| /* print the UDP source and destination */ |
| LWIP_DEBUGF(UDP_DEBUG, |
| ("udp (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") <-- " |
| "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\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))); |
| |
| #if LWIP_DHCP |
| pcb = NULL; |
| /* when LWIP_DHCP is active, packets to DHCP_CLIENT_PORT may only be processed by |
| the dhcp module, no other UDP pcb may use the local UDP port DHCP_CLIENT_PORT */ |
| if (dest == DHCP_CLIENT_PORT) { |
| /* all packets for DHCP_CLIENT_PORT not coming from DHCP_SERVER_PORT are dropped! */ |
| if (src == DHCP_SERVER_PORT) { |
| if ((inp->dhcp != NULL) && (inp->dhcp->pcb != NULL)) { |
| /* accept the packe if |
| (- broadcast or directed to us) -> DHCP is link-layer-addressed, local ip is always ANY! |
| - inp->dhcp->pcb->remote == ANY or iphdr->src */ |
| if ((ip_addr_isany(&inp->dhcp->pcb->remote_ip) || |
| ip_addr_cmp(&(inp->dhcp->pcb->remote_ip), &(iphdr->src)))) { |
| pcb = inp->dhcp->pcb; |
| } |
| } |
| } |
| } else |
| #endif /* LWIP_DHCP */ |
| { |
| prev = NULL; |
| local_match = 0; |
| uncon_pcb = NULL; |
| /* Iterate through the UDP pcb list for a matching pcb. |
| * 'Perfect match' pcbs (connected to the remote port & ip address) are |
| * preferred. If no perfect match is found, the first unconnected pcb that |
| * matches the local port and ip address gets the datagram. */ |
| for (pcb = udp_pcbs; pcb != NULL; pcb = pcb->next) { |
| local_match = 0; |
| /* print the PCB local and remote address */ |
| LWIP_DEBUGF(UDP_DEBUG, |
| ("pcb (%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F") --- " |
| "(%"U16_F".%"U16_F".%"U16_F".%"U16_F", %"U16_F")\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)); |
| |
| /* compare PCB local addr+port to UDP destination addr+port */ |
| if ((pcb->local_port == dest) && |
| ((!broadcast && ip_addr_isany(&pcb->local_ip)) || |
| ip_addr_cmp(&(pcb->local_ip), &(iphdr->dest)) || |
| #if LWIP_IGMP |
| ip_addr_ismulticast(&(iphdr->dest)) || |
| #endif /* LWIP_IGMP */ |
| #if IP_SOF_BROADCAST_RECV |
| (broadcast && (pcb->so_options & SOF_BROADCAST)))) { |
| #else /* IP_SOF_BROADCAST_RECV */ |
| (broadcast))) { |
| #endif /* IP_SOF_BROADCAST_RECV */ |
| local_match = 1; |
| if ((uncon_pcb == NULL) && |
| ((pcb->flags & UDP_FLAGS_CONNECTED) == 0)) { |
| /* the first unconnected matching PCB */ |
| uncon_pcb = pcb; |
| } |
| } |
| /* compare PCB remote addr+port to UDP source addr+port */ |
| if ((local_match != 0) && |
| (pcb->remote_port == src) && |
| (ip_addr_isany(&pcb->remote_ip) || |
| ip_addr_cmp(&(pcb->remote_ip), &(iphdr->src)))) { |
| /* the first fully matching PCB */ |
| if (prev != NULL) { |
| /* move the pcb to the front of udp_pcbs so that is |
| found faster next time */ |
| prev->next = pcb->next; |
| pcb->next = udp_pcbs; |
| udp_pcbs = pcb; |
| } else { |
| UDP_STATS_INC(udp.cachehit); |
| } |
| break; |
| } |
| prev = pcb; |
| } |
| /* no fully matching pcb found? then look for an unconnected pcb */ |
| if (pcb == NULL) { |
| pcb = uncon_pcb; |
| } |
| } |
| |
| /* 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)) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: calculating checksum\n")); |
| #if LWIP_UDPLITE |
| if (IPH_PROTO(iphdr) == IP_PROTO_UDPLITE) { |
| /* Do the UDP Lite checksum */ |
| #if CHECKSUM_CHECK_UDP |
| u16_t chklen = ntohs(udphdr->len); |
| if (chklen < sizeof(struct udp_hdr)) { |
| if (chklen == 0) { |
| /* For UDP-Lite, checksum length of 0 means checksum |
| over the complete packet (See RFC 3828 chap. 3.1) */ |
| chklen = p->tot_len; |
| } else { |
| /* At least the UDP-Lite header must be covered by the |
| checksum! (Again, see RFC 3828 chap. 3.1) */ |
| UDP_STATS_INC(udp.chkerr); |
| UDP_STATS_INC(udp.drop); |
| snmp_inc_udpinerrors(); |
| pbuf_free(p); |
| goto end; |
| } |
| } |
| if (inet_chksum_pseudo_partial(p, (struct ip_addr *)&(iphdr->src), |
| (struct ip_addr *)&(iphdr->dest), |
| IP_PROTO_UDPLITE, p->tot_len, chklen) != 0) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, |
| ("udp_input: UDP Lite datagram discarded due to failing checksum\n")); |
| UDP_STATS_INC(udp.chkerr); |
| UDP_STATS_INC(udp.drop); |
| snmp_inc_udpinerrors(); |
| pbuf_free(p); |
| goto end; |
| } |
| #endif /* CHECKSUM_CHECK_UDP */ |
| } else |
| #endif /* LWIP_UDPLITE */ |
| { |
| #if CHECKSUM_CHECK_UDP |
| 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) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, |
| ("udp_input: UDP datagram discarded due to failing checksum\n")); |
| UDP_STATS_INC(udp.chkerr); |
| UDP_STATS_INC(udp.drop); |
| snmp_inc_udpinerrors(); |
| pbuf_free(p); |
| goto end; |
| } |
| } |
| #endif /* CHECKSUM_CHECK_UDP */ |
| } |
| if(pbuf_header(p, -UDP_HLEN)) { |
| /* Can we cope with this failing? Just assert for now */ |
| LWIP_ASSERT("pbuf_header failed\n", 0); |
| UDP_STATS_INC(udp.drop); |
| snmp_inc_udpinerrors(); |
| pbuf_free(p); |
| goto end; |
| } |
| if (pcb != NULL) { |
| snmp_inc_udpindatagrams(); |
| /* callback */ |
| if (pcb->recv != NULL) { |
| /* now the recv function is responsible for freeing p */ |
| pcb->recv(pcb->recv_arg, pcb, p, &iphdr->src, src); |
| } else { |
| /* no recv function registered? then we have to free the pbuf! */ |
| pbuf_free(p); |
| goto end; |
| } |
| } else { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_input: not for us.\n")); |
| |
| #if LWIP_ICMP |
| /* No match was found, send ICMP destination port unreachable unless |
| destination address was broadcast/multicast. */ |
| if (!broadcast && |
| !ip_addr_ismulticast(&iphdr->dest)) { |
| /* move payload pointer back to ip header */ |
| pbuf_header(p, (IPH_HL(iphdr) * 4) + UDP_HLEN); |
| LWIP_ASSERT("p->payload == iphdr", (p->payload == iphdr)); |
| icmp_dest_unreach(p, ICMP_DUR_PORT); |
| } |
| #endif /* LWIP_ICMP */ |
| UDP_STATS_INC(udp.proterr); |
| UDP_STATS_INC(udp.drop); |
| 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 p chain of pbuf's to be sent. |
| * |
| * The datagram will be sent to the current remote_ip & remote_port |
| * stored in pcb. If the pcb is not bound to a port, it will |
| * automatically be bound to a random port. |
| * |
| * @return lwIP error code. |
| * - ERR_OK. Successful. No error occured. |
| * - ERR_MEM. Out of memory. |
| * - ERR_RTE. Could not find route to destination address. |
| * - More errors could be returned by lower protocol layers. |
| * |
| * @see udp_disconnect() udp_sendto() |
| */ |
| err_t |
| udp_send(struct udp_pcb *pcb, struct pbuf *p) |
| { |
| /* send to the packet using remote ip and port stored in the pcb */ |
| return udp_sendto(pcb, p, &pcb->remote_ip, pcb->remote_port); |
| } |
| |
| /** |
| * Send data to a specified address using UDP. |
| * |
| * @param pcb UDP PCB used to send the data. |
| * @param p chain of pbuf's to be sent. |
| * @param dst_ip Destination IP address. |
| * @param dst_port Destination UDP port. |
| * |
| * dst_ip & dst_port are expected to be in the same byte order as in the pcb. |
| * |
| * If the PCB already has a remote address association, it will |
| * be restored after the data is sent. |
| * |
| * @return lwIP error code (@see udp_send for possible error codes) |
| * |
| * @see udp_disconnect() udp_send() |
| */ |
| err_t |
| udp_sendto(struct udp_pcb *pcb, struct pbuf *p, |
| struct ip_addr *dst_ip, u16_t dst_port) |
| { |
| struct netif *netif; |
| |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send\n")); |
| |
| /* find the outgoing network interface for this packet */ |
| #if LWIP_IGMP |
| netif = ip_route((ip_addr_ismulticast(dst_ip))?(&(pcb->multicast_ip)):(dst_ip)); |
| #else |
| netif = ip_route(dst_ip); |
| #endif /* LWIP_IGMP */ |
| |
| /* no outgoing network interface could be found? */ |
| if (netif == NULL) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: No route to 0x%"X32_F"\n", dst_ip->addr)); |
| UDP_STATS_INC(udp.rterr); |
| return ERR_RTE; |
| } |
| return udp_sendto_if(pcb, p, dst_ip, dst_port, netif); |
| } |
| |
| /** |
| * Send data to a specified address using UDP. |
| * The netif used for sending can be specified. |
| * |
| * This function exists mainly for DHCP, to be able to send UDP packets |
| * on a netif that is still down. |
| * |
| * @param pcb UDP PCB used to send the data. |
| * @param p chain of pbuf's to be sent. |
| * @param dst_ip Destination IP address. |
| * @param dst_port Destination UDP port. |
| * @param netif the netif used for sending. |
| * |
| * dst_ip & dst_port are expected to be in the same byte order as in the pcb. |
| * |
| * @return lwIP error code (@see udp_send for possible error codes) |
| * |
| * @see udp_disconnect() udp_send() |
| */ |
| err_t |
| udp_sendto_if(struct udp_pcb *pcb, struct pbuf *p, |
| struct ip_addr *dst_ip, u16_t dst_port, struct netif *netif) |
| { |
| struct udp_hdr *udphdr; |
| struct ip_addr *src_ip; |
| err_t err; |
| struct pbuf *q; /* q will be sent down the stack */ |
| |
| #if IP_SOF_BROADCAST |
| /* broadcast filter? */ |
| if ( ((pcb->so_options & SOF_BROADCAST) == 0) && ip_addr_isbroadcast(dst_ip, netif) ) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_LEVEL_SERIOUS, |
| ("udp_sendto_if: SOF_BROADCAST not enabled on pcb %p\n", (void *)pcb)); |
| return ERR_VAL; |
| } |
| #endif /* IP_SOF_BROADCAST */ |
| |
| /* if the PCB is not yet bound to a port, bind it here */ |
| if (pcb->local_port == 0) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_send: not yet bound to a port, binding now\n")); |
| err = udp_bind(pcb, &pcb->local_ip, pcb->local_port); |
| if (err != ERR_OK) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: forced port bind failed\n")); |
| return err; |
| } |
| } |
| |
| /* not enough space to add an UDP header to first pbuf in given p chain? */ |
| if (pbuf_header(p, UDP_HLEN)) { |
| /* allocate header in a separate new pbuf */ |
| q = pbuf_alloc(PBUF_IP, UDP_HLEN, PBUF_RAM); |
| /* new header pbuf could not be allocated? */ |
| if (q == NULL) { |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_LEVEL_SERIOUS, ("udp_send: could not allocate header\n")); |
| return ERR_MEM; |
| } |
| /* chain header q in front of given pbuf p */ |
| pbuf_chain(q, p); |
| /* first pbuf q points to header pbuf */ |
| LWIP_DEBUGF(UDP_DEBUG, |
| ("udp_send: added header pbuf %p before given pbuf %p\n", (void *)q, (void *)p)); |
| } else { |
| /* adding space for header within p succeeded */ |
| /* first pbuf q equals given pbuf */ |
| q = p; |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: added header in given pbuf %p\n", (void *)p)); |
| } |
| LWIP_ASSERT("check that first pbuf can hold struct udp_hdr", |
| (q->len >= sizeof(struct udp_hdr))); |
| /* q now represents the packet to be sent */ |
| udphdr = q->payload; |
| udphdr->src = htons(pcb->local_port); |
| udphdr->dest = htons(dst_port); |
| /* in UDP, 0 checksum means 'no checksum' */ |
| udphdr->chksum = 0x0000; |
| |
| /* PCB local address is IP_ANY_ADDR? */ |
| if (ip_addr_isany(&pcb->local_ip)) { |
| /* use outgoing network interface IP address as source address */ |
| src_ip = &(netif->ip_addr); |
| } else { |
| /* check if UDP PCB local IP address is correct |
| * this could be an old address if netif->ip_addr has changed */ |
| if (!ip_addr_cmp(&(pcb->local_ip), &(netif->ip_addr))) { |
| /* local_ip doesn't match, drop the packet */ |
| if (q != p) { |
| /* free the header pbuf */ |
| pbuf_free(q); |
| q = NULL; |
| /* p is still referenced by the caller, and will live on */ |
| } |
| return ERR_VAL; |
| } |
| /* use UDP PCB local IP address as source address */ |
| src_ip = &(pcb->local_ip); |
| } |
| |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: sending datagram of length %"U16_F"\n", q->tot_len)); |
| |
| #if LWIP_UDPLITE |
| /* UDP Lite protocol? */ |
| if (pcb->flags & UDP_FLAGS_UDPLITE) { |
| u16_t chklen, chklen_hdr; |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE packet length %"U16_F"\n", q->tot_len)); |
| /* set UDP message length in UDP header */ |
| chklen_hdr = chklen = pcb->chksum_len_tx; |
| if ((chklen < sizeof(struct udp_hdr)) || (chklen > q->tot_len)) { |
| if (chklen != 0) { |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP LITE pcb->chksum_len is illegal: %"U16_F"\n", chklen)); |
| } |
| /* For UDP-Lite, checksum length of 0 means checksum |
| over the complete packet. (See RFC 3828 chap. 3.1) |
| At least the UDP-Lite header must be covered by the |
| checksum, therefore, if chksum_len has an illegal |
| value, we generate the checksum over the complete |
| packet to be safe. */ |
| chklen_hdr = 0; |
| chklen = q->tot_len; |
| } |
| udphdr->len = htons(chklen_hdr); |
| /* calculate checksum */ |
| #if CHECKSUM_GEN_UDP |
| udphdr->chksum = inet_chksum_pseudo_partial(q, src_ip, dst_ip, |
| IP_PROTO_UDPLITE, q->tot_len, chklen); |
| /* chksum zero must become 0xffff, as zero means 'no checksum' */ |
| if (udphdr->chksum == 0x0000) |
| udphdr->chksum = 0xffff; |
| #endif /* CHECKSUM_CHECK_UDP */ |
| /* output to IP */ |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDPLITE,)\n")); |
| #if LWIP_NETIF_HWADDRHINT |
| netif->addr_hint = &(pcb->addr_hint); |
| #endif /* LWIP_NETIF_HWADDRHINT*/ |
| err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDPLITE, netif); |
| #if LWIP_NETIF_HWADDRHINT |
| netif->addr_hint = NULL; |
| #endif /* LWIP_NETIF_HWADDRHINT*/ |
| } else |
| #endif /* LWIP_UDPLITE */ |
| { /* UDP */ |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP packet length %"U16_F"\n", q->tot_len)); |
| udphdr->len = htons(q->tot_len); |
| /* calculate checksum */ |
| #if CHECKSUM_GEN_UDP |
| if ((pcb->flags & UDP_FLAGS_NOCHKSUM) == 0) { |
| udphdr->chksum = inet_chksum_pseudo(q, src_ip, dst_ip, IP_PROTO_UDP, q->tot_len); |
| /* chksum zero must become 0xffff, as zero means 'no checksum' */ |
| if (udphdr->chksum == 0x0000) udphdr->chksum = 0xffff; |
| } |
| #endif /* CHECKSUM_CHECK_UDP */ |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: UDP checksum 0x%04"X16_F"\n", udphdr->chksum)); |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_send: ip_output_if (,,,,IP_PROTO_UDP,)\n")); |
| /* output to IP */ |
| #if LWIP_NETIF_HWADDRHINT |
| netif->addr_hint = &(pcb->addr_hint); |
| #endif /* LWIP_NETIF_HWADDRHINT*/ |
| err = ip_output_if(q, src_ip, dst_ip, pcb->ttl, pcb->tos, IP_PROTO_UDP, netif); |
| #if LWIP_NETIF_HWADDRHINT |
| netif->addr_hint = NULL; |
| #endif /* LWIP_NETIF_HWADDRHINT*/ |
| } |
| /* TODO: must this be increased even if error occured? */ |
| snmp_inc_udpoutdatagrams(); |
| |
| /* did we chain a separate header pbuf earlier? */ |
| if (q != p) { |
| /* free the header pbuf */ |
| pbuf_free(q); |
| q = NULL; |
| /* p is still referenced by the caller, and will live on */ |
| } |
| |
| UDP_STATS_INC(udp.xmit); |
| 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. Use 0 to automatically bind |
| * to a random port between UDP_LOCAL_PORT_RANGE_START and |
| * UDP_LOCAL_PORT_RANGE_END. |
| * |
| * ipaddr & port are expected to be in the same byte order as in the pcb. |
| * |
| * @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; |
| |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, ("udp_bind(ipaddr = ")); |
| ip_addr_debug_print(UDP_DEBUG, ipaddr); |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE, (", port = %"U16_F")\n", port)); |
| |
| 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) { |
| /* pcb may occur at most once in active list */ |
| LWIP_ASSERT("rebind == 0", rebind == 0); |
| /* pcb already in list, just rebind */ |
| rebind = 1; |
| } |
| |
| /* this code does not allow upper layer to share a UDP port for |
| listening to broadcast or multicast traffic (See SO_REUSE_ADDR and |
| SO_REUSE_PORT under *BSD). TODO: See where it fits instead, OR |
| combine with implementation of UDP PCB flags. Leon Woestenberg. */ |
| #ifdef LWIP_UDP_TODO |
| /* port matches that of PCB in list? */ |
| else |
| 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 */ |
| LWIP_DEBUGF(UDP_DEBUG, |
| ("udp_bind: local port %"U16_F" already bound by another pcb\n", port)); |
| return ERR_USE; |
| } |
| #endif |
| } |
| |
| ip_addr_set(&pcb->local_ip, ipaddr); |
| |
| /* no port specified? */ |
| 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 is already used by another udp_pcb */ |
| port++; |
| /* restart scanning all udp pcbs */ |
| ipcb = udp_pcbs; |
| } else |
| /* go on with next udp pcb */ |
| ipcb = ipcb->next; |
| } |
| if (ipcb != NULL) { |
| /* no more ports available in local range */ |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_bind: out of free UDP ports\n")); |
| return ERR_USE; |
| } |
| } |
| pcb->local_port = port; |
| snmp_insert_udpidx_tree(pcb); |
| /* pcb not active yet? */ |
| if (rebind == 0) { |
| /* place the PCB on the active list if not already there */ |
| pcb->next = udp_pcbs; |
| udp_pcbs = pcb; |
| } |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, |
| ("udp_bind: bound to %"U16_F".%"U16_F".%"U16_F".%"U16_F", port %"U16_F"\n", |
| (u16_t)((ntohl(pcb->local_ip.addr) >> 24) & 0xff), |
| (u16_t)((ntohl(pcb->local_ip.addr) >> 16) & 0xff), |
| (u16_t)((ntohl(pcb->local_ip.addr) >> 8) & 0xff), |
| (u16_t)(ntohl(pcb->local_ip.addr) & 0xff), pcb->local_port)); |
| return ERR_OK; |
| } |
| /** |
| * Connect an UDP PCB. |
| * |
| * This will associate the UDP PCB with the remote address. |
| * |
| * @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 |
| * |
| * ipaddr & port are expected to be in the same byte order as in the pcb. |
| * |
| * The udp pcb is bound to a random local port if not already bound. |
| * |
| * @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; |
| pcb->flags |= UDP_FLAGS_CONNECTED; |
| /** TODO: this functionality belongs in upper layers */ |
| #ifdef LWIP_UDP_TODO |
| /* 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) { |
| LWIP_DEBUGF(UDP_DEBUG, ("udp_connect: No route to 0x%lx\n", pcb->remote_ip.addr)); |
| UDP_STATS_INC(udp.rterr); |
| return ERR_RTE; |
| } |
| /** TODO: this will bind the udp pcb locally, to the interface which |
| is used to route output packets to the remote address. However, we |
| might want to accept incoming packets on any interface! */ |
| pcb->local_ip = netif->ip_addr; |
| } else if (ip_addr_isany(&pcb->remote_ip)) { |
| pcb->local_ip.addr = 0; |
| } |
| #endif |
| LWIP_DEBUGF(UDP_DEBUG | LWIP_DBG_TRACE | LWIP_DBG_STATE, |
| ("udp_connect: connected to %"U16_F".%"U16_F".%"U16_F".%"U16_F",port %"U16_F"\n", |
| (u16_t)((ntohl(pcb->remote_ip.addr) >> 24) & 0xff), |
| (u16_t)((ntohl(pcb->remote_ip.addr) >> 16) & 0xff), |
| (u16_t)((ntohl(pcb->remote_ip.addr) >> 8) & 0xff), |
| (u16_t)(ntohl(pcb->remote_ip.addr) & 0xff), pcb->remote_port)); |
| |
| /* 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; |
| } |
| |
| /** |
| * Disconnect a UDP PCB |
| * |
| * @param pcb the udp pcb to disconnect. |
| */ |
| void |
| udp_disconnect(struct udp_pcb *pcb) |
| { |
| /* reset remote address association */ |
| ip_addr_set(&pcb->remote_ip, IP_ADDR_ANY); |
| pcb->remote_port = 0; |
| /* mark PCB as unconnected */ |
| pcb->flags &= ~UDP_FLAGS_CONNECTED; |
| } |
| |
| /** |
| * Set a receive callback for a UDP PCB |
| * |
| * This callback will be called when receiving a datagram for the pcb. |
| * |
| * @param pcb the pcb for wich to set the recv callback |
| * @param recv function pointer of the callback function |
| * @param recv_arg additional argument to pass to the callback function |
| */ |
| 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; |
| |
| snmp_delete_udpidx_tree(pcb); |
| /* 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) { |
| /* UDP Lite: by initializing to all zeroes, chksum_len is set to 0 |
| * which means checksum is generated over the whole datagram per default |
| * (recommended as default by RFC 3828). */ |
| /* initialize PCB to all zeroes */ |
| memset(pcb, 0, sizeof(struct udp_pcb)); |
| pcb->ttl = UDP_TTL; |
| } |
| return pcb; |
| } |
| |
| #if UDP_DEBUG |
| /** |
| * Print UDP header information for debug purposes. |
| * |
| * @param udphdr pointer to the udp header in memory. |
| */ |
| void |
| udp_debug_print(struct udp_hdr *udphdr) |
| { |
| LWIP_DEBUGF(UDP_DEBUG, ("UDP header:\n")); |
| LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); |
| LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | %5"U16_F" | (src port, dest port)\n", |
| ntohs(udphdr->src), ntohs(udphdr->dest))); |
| LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); |
| LWIP_DEBUGF(UDP_DEBUG, ("| %5"U16_F" | 0x%04"X16_F" | (len, chksum)\n", |
| ntohs(udphdr->len), ntohs(udphdr->chksum))); |
| LWIP_DEBUGF(UDP_DEBUG, ("+-------------------------------+\n")); |
| } |
| #endif /* UDP_DEBUG */ |
| |
| #endif /* LWIP_UDP */ |