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         t->error = add_rn_output(rn, tmpbuf, packet_size);
  86         if (t->error < 0)
  87                 return;
  88 success:
  89         t->error = 1;
  90 }
  91
  92 static void udp_shutdown(void)
  93 {
  94         return;
  95 }
  96
  97 static void udp_recv_close(struct receiver_node *rn)
  98 {
  99         struct private_udp_recv_data *purd = rn->private_data;
 100
 101         if (purd->fd >= 0)
 102                 close(purd->fd);
 103         free(rn->private_data);
 104         free(rn->buf);
 105 }
 106
 107 static void *udp_recv_parse_config(int argc, char **argv)
 108 {
 109         int ret;
 110         struct udp_recv_args_info *tmp =
 111                 para_calloc(sizeof(struct udp_recv_args_info));
 112
 113         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 114         if (ret >= 0)
 115                 return tmp;
 116         free(tmp);
 117         return NULL;
 118 }
 119
 120 /*
 121  * Perform AF-independent joining of multicast receive addresses.
 122  *
 123  * \param fd    Bound socket descriptor.
 124  * \param iface The receiving multicast interface, or NULL for the default.
 125  *
 126  * \return Zero if okay, negative on error.
 127  */
 128 static int mcast_receiver_setup(int fd, const char *iface)
 129 {
 130         struct sockaddr_storage ss;
 131         socklen_t sslen = sizeof(ss);
 132         int id = iface == NULL ? 0 : if_nametoindex(iface);
 133
 134         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 135                 goto err;
 136
 137         if (iface != NULL && id == 0)
 138                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
 139
 140         switch (ss.ss_family) {
 141         case AF_INET:
 142                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 143 #ifdef HAVE_IP_MREQN
 144                         struct ip_mreqn m4;
 145
 146                         m4.imr_address.s_addr   = INADDR_ANY;
 147                         m4.imr_ifindex          = id;
 148 #else
 149                         struct ip_mreq m4;
 150
 151                         m4.imr_interface.s_addr = INADDR_ANY;
 152                         if (id != 0)
 153                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported.");
 154
 155 #endif
 156                         m4.imr_multiaddr        = ((struct sockaddr_in *)&ss)->sin_addr;
 157
 158                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &m4, sizeof(m4)) < 0)
 159                                 break;
 160                 }
 161                 return 0;
 162         case AF_INET6:
 163                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 164                         struct ipv6_mreq m6;
 165
 166                         memset(&m6, 0, sizeof(m6));
 167                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 168                         m6.ipv6mr_interface = id;
 169                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 170                                 break;
 171                 }
 172                 return 0;
 173         default:
 174                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 175                 return -E_ADDRESS_LOOKUP;
 176         }
 177 err:
 178         return -ERRNO_TO_PARA_ERROR(errno);
 179 }
 180
 181 static int udp_recv_open(struct receiver_node *rn)
 182 {
 183         struct private_udp_recv_data *purd;
 184         struct udp_recv_args_info *c = rn->conf;
 185         char  *iface = c->iface_given ? c->iface_arg : NULL;
 186         int ret;
 187
 188         rn->buf = para_calloc(UDP_RECV_CHUNK_SIZE);
 189         rn->private_data = para_calloc(sizeof(struct private_udp_recv_data));
 190         purd = rn->private_data;
 191
 192         ret = makesock(AF_UNSPEC, IPPROTO_UDP, 1, c->host_arg, c->port_arg);
 193         if (ret < 0)
 194                 goto err;
 195         purd->fd = ret;
 196
 197         ret = mcast_receiver_setup(purd->fd, iface);
 198         if (ret < 0) {
 199                 close(purd->fd);
 200                 return ret;
 201         }
 202
 203         ret = mark_fd_nonblocking(purd->fd);
 204         if (ret < 0)
 205                 goto err;
 206         PARA_NOTICE_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 207                 c->port_arg, purd->fd);
 208         return purd->fd;
 209 err:
 210         free(rn->private_data);
 211         free(rn->buf);
 212         return ret;
 213 }
 214
 215 /**
 216  * The init function of the udp receiver.
 217  *
 218  * \param r Pointer to the receiver struct to initialize.
 219  *
 220  * Initialize all function pointers of \a r.
 221  */
 222 void udp_recv_init(struct receiver *r)
 223 {
 224         struct udp_recv_args_info dummy;
 225
 226         udp_recv_cmdline_parser_init(&dummy);
 227         r->shutdown = udp_shutdown;
 228         r->open = udp_recv_open;
 229         r->close = udp_recv_close;
 230         r->pre_select = udp_recv_pre_select;
 231         r->post_select = udp_recv_post_select;
 232         r->parse_config = udp_recv_parse_config;
 233         r->help = (struct ggo_help) {
 234                 .short_help = udp_recv_args_info_help,
 235                 .detailed_help = udp_recv_args_info_detailed_help
 236         };
 237 }