udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2011 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 <dirent.h>
  10 #include <sys/socket.h>
  11 #include <net/if.h>
  12
  13 #include "para.h"
  14 #include "error.h"
  15 #include "portable_io.h"
  16 #include "list.h"
  17 #include "sched.h"
  18 #include "ggo.h"
  19 #include "recv.h"
  20 #include "udp_recv.cmdline.h"
  21 #include "string.h"
  22 #include "net.h"
  23 #include "fd.h"
  24 #include "buffer_tree.h"
  25
  26 /**
  27  * Data specific to the udp receiver.
  28  *
  29  * \sa \ref receiver, \ref receiver_node.
  30  */
  31 struct private_udp_recv_data {
  32         /** The socket file descriptor. */
  33         int fd;
  34         struct btr_pool *btrp;
  35 };
  36
  37 static void udp_recv_pre_select(struct sched *s, struct task *t)
  38 {
  39         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  40         struct private_udp_recv_data *purd = rn->private_data;
  41
  42         if (generic_recv_pre_select(s, t) <= 0)
  43                 return;
  44         para_fd_set(purd->fd, &s->rfds, &s->max_fileno);
  45 }
  46
  47 static int udp_check_eof(size_t sz, struct iovec iov[2])
  48 {
  49         if (sz < FEC_EOF_PACKET_LEN)
  50                 return 0;
  51         if (iov[0].iov_len >= FEC_EOF_PACKET_LEN) {
  52                 if (memcmp(iov[0].iov_base, FEC_EOF_PACKET,
  53                                 FEC_EOF_PACKET_LEN) != 0)
  54                         return 0;
  55                 return -E_RECV_EOF;
  56         }
  57         if (memcmp(iov[0].iov_base, FEC_EOF_PACKET, iov[0].iov_len) != 0)
  58                 return 0;
  59         if (memcmp(iov[1].iov_base, FEC_EOF_PACKET + iov[0].iov_len,
  60                         FEC_EOF_PACKET_LEN - iov[0].iov_len) != 0)
  61                 return 0;
  62         return -E_RECV_EOF;
  63 }
  64
  65 static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
  66 {
  67         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  68         struct private_udp_recv_data *purd = rn->private_data;
  69         struct btr_node *btrn = rn->btrn;
  70         size_t num_bytes;
  71         struct iovec iov[2];
  72         int ret, readv_ret, iovcnt;
  73
  74         t->error = 0;
  75         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  76         if (ret <= 0)
  77                 goto out;
  78         iovcnt = btr_pool_get_buffers(purd->btrp, iov);
  79         ret = -E_UDP_OVERRUN;
  80         if (iovcnt == 0)
  81                 goto out;
  82         ret = readv_nonblock(purd->fd, iov, iovcnt, &s->rfds, &num_bytes);
  83         if (num_bytes == 0)
  84                 goto out;
  85         readv_ret = ret;
  86         ret = udp_check_eof(num_bytes, iov);
  87         if (ret < 0)
  88                 goto out;
  89         if (iov[0].iov_len >= num_bytes)
  90                 btr_add_output_pool(purd->btrp, num_bytes, btrn);
  91         else { /* both buffers contain data */
  92                 btr_add_output_pool(purd->btrp, iov[0].iov_len, btrn);
  93                 btr_add_output_pool(purd->btrp, num_bytes - iov[0].iov_len,
  94                         btrn);
  95         }
  96         ret = readv_ret;
  97 out:
  98         if (ret >= 0)
  99                 return;
 100         btr_remove_node(btrn);
 101         t->error = ret;
 102         close(purd->fd);
 103         purd->fd = -1;
 104 }
 105
 106 static void udp_recv_close(struct receiver_node *rn)
 107 {
 108         struct private_udp_recv_data *purd = rn->private_data;
 109
 110         if (purd->fd >= 0)
 111                 close(purd->fd);
 112         btr_pool_free(purd->btrp);
 113         free(rn->private_data);
 114 }
 115
 116 static void *udp_recv_parse_config(int argc, char **argv)
 117 {
 118         int ret;
 119         struct udp_recv_args_info *tmp =
 120                 para_calloc(sizeof(struct udp_recv_args_info));
 121
 122         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 123         if (ret >= 0)
 124                 return tmp;
 125         free(tmp);
 126         return NULL;
 127 }
 128
 129 /*
 130  * Perform AF-independent joining of multicast receive addresses.
 131  *
 132  * \param fd    Bound socket descriptor.
 133  * \param iface The receiving multicast interface, or NULL for the default.
 134  *
 135  * \return Zero if okay, negative on error.
 136  */
 137 static int mcast_receiver_setup(int fd, const char *iface)
 138 {
 139         struct sockaddr_storage ss;
 140         socklen_t sslen = sizeof(ss);
 141         int id = iface == NULL ? 0 : if_nametoindex(iface);
 142
 143         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 144                 goto err;
 145         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 146
 147         if (iface != NULL && id == 0)
 148                 PARA_WARNING_LOG("could not resolve interface %s, using default\n",
 149                         iface);
 150
 151         switch (ss.ss_family) {
 152         case AF_INET:
 153                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 154 #ifdef HAVE_IP_MREQN
 155                         struct ip_mreqn m4;
 156
 157                         m4.imr_address.s_addr   = INADDR_ANY;
 158                         m4.imr_ifindex          = id;
 159 #else
 160                         struct ip_mreq m4;
 161
 162                         m4.imr_interface.s_addr = INADDR_ANY;
 163                         if (id != 0)
 164                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported\n");
 165
 166 #endif
 167                         m4.imr_multiaddr = ((struct sockaddr_in *)&ss)->sin_addr;
 168
 169                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 170                                         &m4, sizeof(m4)) < 0)
 171                                 break;
 172                 }
 173                 return 0;
 174         case AF_INET6:
 175                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 176                         struct ipv6_mreq m6;
 177
 178                         memset(&m6, 0, sizeof(m6));
 179                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 180                         m6.ipv6mr_interface = id;
 181                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 182                                 break;
 183                 }
 184                 return 0;
 185         }
 186 err:
 187         return -ERRNO_TO_PARA_ERROR(errno);
 188 }
 189
 190 static int udp_recv_open(struct receiver_node *rn)
 191 {
 192         struct private_udp_recv_data *purd;
 193         struct udp_recv_args_info *c = rn->conf;
 194         char  *iface = c->iface_given ? c->iface_arg : NULL;
 195         int ret;
 196
 197         rn->private_data = para_calloc(sizeof(struct private_udp_recv_data));
 198         purd = rn->private_data;
 199
 200         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 201         if (ret < 0)
 202                 goto err;
 203         purd->fd = ret;
 204
 205         ret = mcast_receiver_setup(purd->fd, iface);
 206         if (ret < 0) {
 207                 close(purd->fd);
 208                 goto err;
 209         }
 210
 211         ret = mark_fd_nonblocking(purd->fd);
 212         if (ret < 0) {
 213                 close(purd->fd);
 214                 goto err;
 215         }
 216         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 217                 c->port_arg, purd->fd);
 218         purd->btrp = btr_pool_new("udp_recv", 320 * 1024);
 219         return purd->fd;
 220 err:
 221         free(rn->private_data);
 222         return ret;
 223 }
 224
 225 static void udp_recv_free_config(void *conf)
 226 {
 227         udp_recv_cmdline_parser_free(conf);
 228         free(conf);
 229 }
 230
 231 /**
 232  * The init function of the udp receiver.
 233  *
 234  * \param r Pointer to the receiver struct to initialize.
 235  *
 236  * Initialize all function pointers of \a r.
 237  */
 238 void udp_recv_init(struct receiver *r)
 239 {
 240         struct udp_recv_args_info dummy;
 241
 242         udp_recv_cmdline_parser_init(&dummy);
 243         r->open = udp_recv_open;
 244         r->close = udp_recv_close;
 245         r->pre_select = udp_recv_pre_select;
 246         r->post_select = udp_recv_post_select;
 247         r->parse_config = udp_recv_parse_config;
 248         r->free_config = udp_recv_free_config;
 249         r->help = (struct ggo_help) {
 250                 .short_help = udp_recv_args_info_help,
 251                 .detailed_help = udp_recv_args_info_detailed_help
 252         };
 253         udp_recv_cmdline_parser_free(&dummy);
 254 }