udp_recv.c

   1 /*
   2  * Copyright (C) 2005 Andre Noll <maan@tuebingen.mpg.de>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6 /** \file udp_recv.c Paraslash's udp receiver */
   7
   8 #include <netinet/in.h>
   9 #include <regex.h>
  10 #include <sys/socket.h>
  11 #include <net/if.h>
  12 #include <sys/types.h>
  13 #include <arpa/inet.h>
  14 #include <sys/un.h>
  15 #include <netdb.h>
  16 #include <lopsub.h>
  17
  18 #include "recv_cmd.lsg.h"
  19 #include "para.h"
  20 #include "error.h"
  21 #include "portable_io.h"
  22 #include "list.h"
  23 #include "sched.h"
  24 #include "buffer_tree.h"
  25 #include "recv.h"
  26 #include "string.h"
  27 #include "net.h"
  28 #include "fd.h"
  29
  30 static void udp_recv_pre_select(struct sched *s, void *context)
  31 {
  32         struct receiver_node *rn = context;
  33
  34         if (generic_recv_pre_select(s, rn) <= 0)
  35                 return;
  36         para_fd_set(rn->fd, &s->rfds, &s->max_fileno);
  37 }
  38
  39 static int udp_check_eof(size_t sz, struct iovec iov[2])
  40 {
  41         if (sz < FEC_EOF_PACKET_LEN)
  42                 return 0;
  43         if (iov[0].iov_len >= FEC_EOF_PACKET_LEN) {
  44                 if (memcmp(iov[0].iov_base, FEC_EOF_PACKET,
  45                                 FEC_EOF_PACKET_LEN) != 0)
  46                         return 0;
  47                 return -E_RECV_EOF;
  48         }
  49         if (memcmp(iov[0].iov_base, FEC_EOF_PACKET, iov[0].iov_len) != 0)
  50                 return 0;
  51         if (memcmp(iov[1].iov_base, &FEC_EOF_PACKET[iov[0].iov_len],
  52                         FEC_EOF_PACKET_LEN - iov[0].iov_len) != 0)
  53                 return 0;
  54         return -E_RECV_EOF;
  55 }
  56
  57 static int udp_recv_post_select(__a_unused struct sched *s, void *context)
  58 {
  59         struct receiver_node *rn = context;
  60         struct btr_node *btrn = rn->btrn;
  61         size_t num_bytes;
  62         struct iovec iov[2];
  63         int ret, readv_ret, iovcnt;
  64
  65         ret = task_get_notification(rn->task);
  66         if (ret < 0)
  67                 goto out;
  68         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  69         if (ret <= 0)
  70                 goto out;
  71         iovcnt = btr_pool_get_buffers(rn->btrp, iov);
  72         ret = -E_UDP_OVERRUN;
  73         if (iovcnt == 0)
  74                 goto out;
  75         ret = readv_nonblock(rn->fd, iov, iovcnt, &s->rfds, &num_bytes);
  76         if (num_bytes == 0)
  77                 goto out;
  78         readv_ret = ret;
  79         ret = udp_check_eof(num_bytes, iov);
  80         if (ret < 0)
  81                 goto out;
  82         if (iov[0].iov_len >= num_bytes)
  83                 btr_add_output_pool(rn->btrp, num_bytes, btrn);
  84         else { /* both buffers contain data */
  85                 btr_add_output_pool(rn->btrp, iov[0].iov_len, btrn);
  86                 btr_add_output_pool(rn->btrp, num_bytes - iov[0].iov_len,
  87                         btrn);
  88         }
  89         ret = readv_ret;
  90 out:
  91         if (ret < 0) {
  92                 btr_remove_node(&rn->btrn);
  93                 close(rn->fd);
  94                 rn->fd = -1;
  95         }
  96         return ret;
  97 }
  98
  99 static void udp_recv_close(struct receiver_node *rn)
 100 {
 101         if (rn->fd >= 0)
 102                 close(rn->fd);
 103         btr_pool_free(rn->btrp);
 104 }
 105
 106 /*
 107  * Perform AF-independent joining of multicast receive addresses.
 108  *
 109  * \param fd    Bound socket descriptor.
 110  * \param iface The receiving multicast interface, or NULL for the default.
 111  *
 112  * \return Zero if okay, negative on error.
 113  */
 114 static int mcast_receiver_setup(int fd, const char *iface)
 115 {
 116         struct sockaddr_storage ss;
 117         socklen_t sslen = sizeof(ss);
 118         int id = iface == NULL ? 0 : if_nametoindex(iface);
 119
 120         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 121                 goto err;
 122         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 123
 124         if (iface != NULL && id == 0)
 125                 PARA_WARNING_LOG("could not resolve interface %s, using default\n",
 126                         iface);
 127
 128         switch (ss.ss_family) {
 129         case AF_INET:
 130                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 131 #ifdef HAVE_IP_MREQN
 132                         struct ip_mreqn m4;
 133
 134                         m4.imr_address.s_addr   = INADDR_ANY;
 135                         m4.imr_ifindex          = id;
 136 #else
 137                         struct ip_mreq m4;
 138
 139                         m4.imr_interface.s_addr = INADDR_ANY;
 140                         if (id != 0)
 141                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported\n");
 142
 143 #endif
 144                         m4.imr_multiaddr = ((struct sockaddr_in *)&ss)->sin_addr;
 145
 146                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 147                                         &m4, sizeof(m4)) < 0)
 148                                 break;
 149                 }
 150                 return 0;
 151         case AF_INET6:
 152                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 153                         struct ipv6_mreq m6;
 154
 155                         memset(&m6, 0, sizeof(m6));
 156                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 157                         m6.ipv6mr_interface = id;
 158                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 159                                 break;
 160                 }
 161                 return 0;
 162         }
 163 err:
 164         return -ERRNO_TO_PARA_ERROR(errno);
 165 }
 166
 167 static int udp_recv_open(struct receiver_node *rn)
 168 {
 169         struct lls_parse_result *lpr = rn->lpr;
 170         const char *iface = RECV_CMD_OPT_STRING_VAL(UDP, IFACE, lpr);
 171         const char *host = RECV_CMD_OPT_STRING_VAL(UDP, HOST, lpr);
 172         uint32_t port = RECV_CMD_OPT_UINT32_VAL(UDP, PORT, lpr);
 173         int ret;
 174
 175         ret = makesock(IPPROTO_UDP, 1, host, port, NULL);
 176         if (ret < 0)
 177                 return ret;
 178         rn->fd = ret;
 179         ret = mcast_receiver_setup(rn->fd, iface);
 180         if (ret < 0)
 181                 goto err;
 182         ret = mark_fd_nonblocking(rn->fd);
 183         if (ret < 0)
 184                 goto err;
 185         PARA_INFO_LOG("receiving from %s:%u, fd=%d\n", host, port, rn->fd);
 186         rn->btrp = btr_pool_new("udp_recv", 320 * 1024);
 187         return rn->fd;
 188 err:
 189         close(rn->fd);
 190         return ret;
 191 }
 192
 193 /** See \ref recv_init(). */
 194 const struct receiver lsg_recv_cmd_com_udp_user_data = {
 195         .open = udp_recv_open,
 196         .close = udp_recv_close,
 197         .pre_select = udp_recv_pre_select,
 198         .post_select = udp_recv_post_select,
 199 };