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