udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2009 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 <dirent.h>
   9 #include <net/if.h>
  10
  11 #include "para.h"
  12 #include "error.h"
  13 #include "portable_io.h"
  14 #include "list.h"
  15 #include "sched.h"
  16 #include "ggo.h"
  17 #include "recv.h"
  18 #include "udp_recv.cmdline.h"
  19 #include "audiod.h"
  20 #include "string.h"
  21 #include "net.h"
  22 #include "fd.h"
  23
  24 /** The size of the receiver node buffer. */
  25 #define UDP_RECV_CHUNK_SIZE (128 * 1024)
  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 };
  35
  36 static void udp_recv_pre_select(struct sched *s, struct task *t)
  37 {
  38         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  39         struct private_udp_recv_data *purd = rn->private_data;
  40
  41         para_fd_set(purd->fd, &s->rfds, &s->max_fileno);
  42 }
  43
  44 static int enough_space(size_t nbytes, size_t loaded)
  45 {
  46         return nbytes + loaded < UDP_RECV_CHUNK_SIZE;
  47 }
  48
  49 static int add_rn_output(struct receiver_node *rn, char *buf, size_t len)
  50 {
  51         if (!len)
  52                 return 1;
  53         if (!enough_space(len, rn->loaded))
  54                 return -E_UDP_OVERRUN;
  55         memcpy(rn->buf + rn->loaded, buf, len);
  56         rn->loaded += len;
  57         return 1;
  58 }
  59
  60 static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
  61 {
  62         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  63         struct private_udp_recv_data *purd = rn->private_data;
  64         int ret;
  65         char tmpbuf[UDP_RECV_CHUNK_SIZE];
  66         size_t packet_size;
  67
  68         if (rn->output_error && *rn->output_error < 0) {
  69                 t->error = *rn->output_error;
  70                 return;
  71         }
  72         if (!FD_ISSET(purd->fd, &s->rfds))
  73                 return;
  74         ret = recv_bin_buffer(purd->fd, tmpbuf, UDP_RECV_CHUNK_SIZE);
  75         if (ret < 0) {
  76                 if (is_errno(ret, EINTR) || is_errno(ret, EAGAIN))
  77                         goto success;
  78                 t->error = ret;
  79                 return;
  80         }
  81         t->error = -E_RECV_EOF;
  82         if (!ret)
  83                 return;
  84         packet_size = ret;
  85         if (packet_size >= FEC_EOF_PACKET_LEN)
  86                 if (!memcmp(tmpbuf, FEC_EOF_PACKET, FEC_EOF_PACKET_LEN))
  87                         return;
  88         t->error = add_rn_output(rn, tmpbuf, packet_size);
  89         if (t->error < 0)
  90                 return;
  91 success:
  92         t->error = 1;
  93 }
  94
  95 static void udp_shutdown(void)
  96 {
  97         return;
  98 }
  99
 100 static void udp_recv_close(struct receiver_node *rn)
 101 {
 102         struct private_udp_recv_data *purd = rn->private_data;
 103
 104         if (purd->fd >= 0)
 105                 close(purd->fd);
 106         free(rn->private_data);
 107         free(rn->buf);
 108 }
 109
 110 static void *udp_recv_parse_config(int argc, char **argv)
 111 {
 112         int ret;
 113         struct udp_recv_args_info *tmp =
 114                 para_calloc(sizeof(struct udp_recv_args_info));
 115
 116         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 117         if (ret >= 0)
 118                 return tmp;
 119         free(tmp);
 120         return NULL;
 121 }
 122
 123 /*
 124  * Perform AF-independent joining of multicast receive addresses.
 125  *
 126  * \param fd    Bound socket descriptor.
 127  * \param iface The receiving multicast interface, or NULL for the default.
 128  *
 129  * \return Zero if okay, negative on error.
 130  */
 131 static int mcast_receiver_setup(int fd, const char *iface)
 132 {
 133         struct sockaddr_storage ss;
 134         socklen_t sslen = sizeof(ss);
 135         int id = iface == NULL ? 0 : if_nametoindex(iface);
 136
 137         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 138                 goto err;
 139
 140         if (iface != NULL && id == 0)
 141                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
 142
 143         switch (ss.ss_family) {
 144         case AF_INET:
 145                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 146 #ifdef HAVE_IP_MREQN
 147                         struct ip_mreqn m4;
 148
 149                         m4.imr_address.s_addr   = INADDR_ANY;
 150                         m4.imr_ifindex          = id;
 151 #else
 152                         struct ip_mreq m4;
 153
 154                         m4.imr_interface.s_addr = INADDR_ANY;
 155                         if (id != 0)
 156                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported.");
 157
 158 #endif
 159                         m4.imr_multiaddr        = ((struct sockaddr_in *)&ss)->sin_addr;
 160
 161                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &m4, sizeof(m4)) < 0)
 162                                 break;
 163                 }
 164                 return 0;
 165         case AF_INET6:
 166                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 167                         struct ipv6_mreq m6;
 168
 169                         memset(&m6, 0, sizeof(m6));
 170                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 171                         m6.ipv6mr_interface = id;
 172                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 173                                 break;
 174                 }
 175                 return 0;
 176         default:
 177                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 178                 return -E_ADDRESS_LOOKUP;
 179         }
 180 err:
 181         return -ERRNO_TO_PARA_ERROR(errno);
 182 }
 183
 184 static int udp_recv_open(struct receiver_node *rn)
 185 {
 186         struct private_udp_recv_data *purd;
 187         struct udp_recv_args_info *c = rn->conf;
 188         char  *iface = c->iface_given ? c->iface_arg : NULL;
 189         int ret;
 190
 191         rn->buf = para_calloc(UDP_RECV_CHUNK_SIZE);
 192         rn->private_data = para_calloc(sizeof(struct private_udp_recv_data));
 193         purd = rn->private_data;
 194
 195         ret = makesock(AF_UNSPEC, IPPROTO_UDP, 1, c->host_arg, c->port_arg);
 196         if (ret < 0)
 197                 goto err;
 198         purd->fd = ret;
 199
 200         ret = mcast_receiver_setup(purd->fd, iface);
 201         if (ret < 0) {
 202                 close(purd->fd);
 203                 return ret;
 204         }
 205
 206         ret = mark_fd_nonblocking(purd->fd);
 207         if (ret < 0)
 208                 goto err;
 209         PARA_NOTICE_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 210                 c->port_arg, purd->fd);
 211         return purd->fd;
 212 err:
 213         free(rn->private_data);
 214         free(rn->buf);
 215         return ret;
 216 }
 217
 218 /**
 219  * The init function of the udp receiver.
 220  *
 221  * \param r Pointer to the receiver struct to initialize.
 222  *
 223  * Initialize all function pointers of \a r.
 224  */
 225 void udp_recv_init(struct receiver *r)
 226 {
 227         struct udp_recv_args_info dummy;
 228
 229         udp_recv_cmdline_parser_init(&dummy);
 230         r->shutdown = udp_shutdown;
 231         r->open = udp_recv_open;
 232         r->close = udp_recv_close;
 233         r->pre_select = udp_recv_pre_select;
 234         r->post_select = udp_recv_post_select;
 235         r->parse_config = udp_recv_parse_config;
 236         r->help = (struct ggo_help) {
 237                 .short_help = udp_recv_args_info_help,
 238                 .detailed_help = udp_recv_args_info_detailed_help
 239         };
 240 }