udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2012 Andre Noll <maan@systemlinux.org>
   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 <regex.h>
   9 #include <sys/socket.h>
  10 #include <net/if.h>
  11
  12 #include "para.h"
  13 #include "error.h"
  14 #include "portable_io.h"
  15 #include "list.h"
  16 #include "sched.h"
  17 #include "ggo.h"
  18 #include "recv.h"
  19 #include "udp_recv.cmdline.h"
  20 #include "string.h"
  21 #include "net.h"
  22 #include "fd.h"
  23 #include "buffer_tree.h"
  24
  25 static void udp_recv_pre_select(struct sched *s, struct task *t)
  26 {
  27         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  28
  29         if (generic_recv_pre_select(s, t) <= 0)
  30                 return;
  31         para_fd_set(rn->fd, &s->rfds, &s->max_fileno);
  32 }
  33
  34 static int udp_check_eof(size_t sz, struct iovec iov[2])
  35 {
  36         if (sz < FEC_EOF_PACKET_LEN)
  37                 return 0;
  38         if (iov[0].iov_len >= FEC_EOF_PACKET_LEN) {
  39                 if (memcmp(iov[0].iov_base, FEC_EOF_PACKET,
  40                                 FEC_EOF_PACKET_LEN) != 0)
  41                         return 0;
  42                 return -E_RECV_EOF;
  43         }
  44         if (memcmp(iov[0].iov_base, FEC_EOF_PACKET, iov[0].iov_len) != 0)
  45                 return 0;
  46         if (memcmp(iov[1].iov_base, FEC_EOF_PACKET + iov[0].iov_len,
  47                         FEC_EOF_PACKET_LEN - iov[0].iov_len) != 0)
  48                 return 0;
  49         return -E_RECV_EOF;
  50 }
  51
  52 static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
  53 {
  54         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  55         struct btr_node *btrn = rn->btrn;
  56         size_t num_bytes;
  57         struct iovec iov[2];
  58         int ret, readv_ret, iovcnt;
  59
  60         t->error = 0;
  61         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  62         if (ret <= 0)
  63                 goto out;
  64         iovcnt = btr_pool_get_buffers(rn->btrp, iov);
  65         ret = -E_UDP_OVERRUN;
  66         if (iovcnt == 0)
  67                 goto out;
  68         ret = readv_nonblock(rn->fd, iov, iovcnt, &s->rfds, &num_bytes);
  69         if (num_bytes == 0)
  70                 goto out;
  71         readv_ret = ret;
  72         ret = udp_check_eof(num_bytes, iov);
  73         if (ret < 0)
  74                 goto out;
  75         if (iov[0].iov_len >= num_bytes)
  76                 btr_add_output_pool(rn->btrp, num_bytes, btrn);
  77         else { /* both buffers contain data */
  78                 btr_add_output_pool(rn->btrp, iov[0].iov_len, btrn);
  79                 btr_add_output_pool(rn->btrp, num_bytes - iov[0].iov_len,
  80                         btrn);
  81         }
  82         ret = readv_ret;
  83 out:
  84         if (ret >= 0)
  85                 return;
  86         btr_remove_node(btrn);
  87         t->error = ret;
  88         close(rn->fd);
  89         rn->fd = -1;
  90 }
  91
  92 static void udp_recv_close(struct receiver_node *rn)
  93 {
  94         if (rn->fd >= 0)
  95                 close(rn->fd);
  96         btr_pool_free(rn->btrp);
  97 }
  98
  99 static void *udp_recv_parse_config(int argc, char **argv)
 100 {
 101         int ret;
 102         struct udp_recv_args_info *tmp =
 103                 para_calloc(sizeof(struct udp_recv_args_info));
 104
 105         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 106         if (ret >= 0)
 107                 return tmp;
 108         free(tmp);
 109         return NULL;
 110 }
 111
 112 /*
 113  * Perform AF-independent joining of multicast receive addresses.
 114  *
 115  * \param fd    Bound socket descriptor.
 116  * \param iface The receiving multicast interface, or NULL for the default.
 117  *
 118  * \return Zero if okay, negative on error.
 119  */
 120 static int mcast_receiver_setup(int fd, const char *iface)
 121 {
 122         struct sockaddr_storage ss;
 123         socklen_t sslen = sizeof(ss);
 124         int id = iface == NULL ? 0 : if_nametoindex(iface);
 125
 126         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 127                 goto err;
 128         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 129
 130         if (iface != NULL && id == 0)
 131                 PARA_WARNING_LOG("could not resolve interface %s, using default\n",
 132                         iface);
 133
 134         switch (ss.ss_family) {
 135         case AF_INET:
 136                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 137 #ifdef HAVE_IP_MREQN
 138                         struct ip_mreqn m4;
 139
 140                         m4.imr_address.s_addr   = INADDR_ANY;
 141                         m4.imr_ifindex          = id;
 142 #else
 143                         struct ip_mreq m4;
 144
 145                         m4.imr_interface.s_addr = INADDR_ANY;
 146                         if (id != 0)
 147                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported\n");
 148
 149 #endif
 150                         m4.imr_multiaddr = ((struct sockaddr_in *)&ss)->sin_addr;
 151
 152                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 153                                         &m4, sizeof(m4)) < 0)
 154                                 break;
 155                 }
 156                 return 0;
 157         case AF_INET6:
 158                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 159                         struct ipv6_mreq m6;
 160
 161                         memset(&m6, 0, sizeof(m6));
 162                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 163                         m6.ipv6mr_interface = id;
 164                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 165                                 break;
 166                 }
 167                 return 0;
 168         }
 169 err:
 170         return -ERRNO_TO_PARA_ERROR(errno);
 171 }
 172
 173 static int udp_recv_open(struct receiver_node *rn)
 174 {
 175         struct udp_recv_args_info *c = rn->conf;
 176         char  *iface = c->iface_given ? c->iface_arg : NULL;
 177         int ret;
 178
 179         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 180         if (ret < 0)
 181                 goto err;
 182         rn->fd = ret;
 183
 184         ret = mcast_receiver_setup(rn->fd, iface);
 185         if (ret < 0) {
 186                 close(rn->fd);
 187                 goto err;
 188         }
 189
 190         ret = mark_fd_nonblocking(rn->fd);
 191         if (ret < 0) {
 192                 close(rn->fd);
 193                 goto err;
 194         }
 195         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 196                 c->port_arg, rn->fd);
 197         rn->btrp = btr_pool_new("udp_recv", 320 * 1024);
 198         return rn->fd;
 199 err:
 200         return ret;
 201 }
 202
 203 static void udp_recv_free_config(void *conf)
 204 {
 205         udp_recv_cmdline_parser_free(conf);
 206         free(conf);
 207 }
 208
 209 /**
 210  * The init function of the udp receiver.
 211  *
 212  * \param r Pointer to the receiver struct to initialize.
 213  *
 214  * Initialize all function pointers of \a r.
 215  */
 216 void udp_recv_init(struct receiver *r)
 217 {
 218         struct udp_recv_args_info dummy;
 219
 220         udp_recv_cmdline_parser_init(&dummy);
 221         r->open = udp_recv_open;
 222         r->close = udp_recv_close;
 223         r->pre_select = udp_recv_pre_select;
 224         r->post_select = udp_recv_post_select;
 225         r->parse_config = udp_recv_parse_config;
 226         r->free_config = udp_recv_free_config;
 227         r->help = (struct ggo_help) {
 228                 .short_help = udp_recv_args_info_help,
 229                 .detailed_help = udp_recv_args_info_detailed_help
 230         };
 231         udp_recv_cmdline_parser_free(&dummy);
 232 }