udp_recv.c

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