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 <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 packet_size;
  71         struct iovec iov[2];
  72         int ret, iovcnt;
  73
  74         t->error = 0;
  75         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  76         if (ret < 0)
  77                 goto err;
  78         if (ret == 0)
  79                 return;
  80         if (!FD_ISSET(purd->fd, &s->rfds))
  81                 return;
  82         iovcnt = btr_pool_get_buffers(purd->btrp, iov);
  83         ret = -E_UDP_OVERRUN;
  84         if (iovcnt == 0)
  85                 goto err;
  86         ret = para_readv(purd->fd, iov, iovcnt);
  87         /* EAGAIN is possible even if FD_ISSET */
  88         if (ret < 0 && is_errno(-ret, EAGAIN))
  89                 return;
  90         if (ret == 0)
  91                 ret = -E_RECV_EOF;
  92         if (ret < 0)
  93                 goto err;
  94         packet_size = ret;
  95         ret = udp_check_eof(packet_size, iov);
  96         if (ret < 0)
  97                 goto err;
  98         if (iov[0].iov_len >= packet_size)
  99                 btr_add_output_pool(purd->btrp, packet_size, btrn);
 100         else { /* both buffers contain data */
 101                 btr_add_output_pool(purd->btrp, iov[0].iov_len, btrn);
 102                 btr_add_output_pool(purd->btrp, packet_size - iov[0].iov_len,
 103                         btrn);
 104         }
 105         return;
 106 err:
 107         btr_remove_node(btrn);
 108         t->error = ret;
 109         close(purd->fd);
 110         purd->fd = -1;
 111 }
 112
 113 static void udp_recv_close(struct receiver_node *rn)
 114 {
 115         struct private_udp_recv_data *purd = rn->private_data;
 116
 117         if (purd->fd >= 0)
 118                 close(purd->fd);
 119         btr_pool_free(purd->btrp);
 120         free(rn->private_data);
 121 }
 122
 123 static void *udp_recv_parse_config(int argc, char **argv)
 124 {
 125         int ret;
 126         struct udp_recv_args_info *tmp =
 127                 para_calloc(sizeof(struct udp_recv_args_info));
 128
 129         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 130         if (ret >= 0)
 131                 return tmp;
 132         free(tmp);
 133         return NULL;
 134 }
 135
 136 /*
 137  * Perform AF-independent joining of multicast receive addresses.
 138  *
 139  * \param fd    Bound socket descriptor.
 140  * \param iface The receiving multicast interface, or NULL for the default.
 141  *
 142  * \return Zero if okay, negative on error.
 143  */
 144 static int mcast_receiver_setup(int fd, const char *iface)
 145 {
 146         struct sockaddr_storage ss;
 147         socklen_t sslen = sizeof(ss);
 148         int id = iface == NULL ? 0 : if_nametoindex(iface);
 149
 150         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 151                 goto err;
 152
 153         if (iface != NULL && id == 0)
 154                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
 155
 156         switch (ss.ss_family) {
 157         case AF_INET:
 158                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 159 #ifdef HAVE_IP_MREQN
 160                         struct ip_mreqn m4;
 161
 162                         m4.imr_address.s_addr   = INADDR_ANY;
 163                         m4.imr_ifindex          = id;
 164 #else
 165                         struct ip_mreq m4;
 166
 167                         m4.imr_interface.s_addr = INADDR_ANY;
 168                         if (id != 0)
 169                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported.");
 170
 171 #endif
 172                         m4.imr_multiaddr        = ((struct sockaddr_in *)&ss)->sin_addr;
 173
 174                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &m4, sizeof(m4)) < 0)
 175                                 break;
 176                 }
 177                 return 0;
 178         case AF_INET6:
 179                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 180                         struct ipv6_mreq m6;
 181
 182                         memset(&m6, 0, sizeof(m6));
 183                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 184                         m6.ipv6mr_interface = id;
 185                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 186                                 break;
 187                 }
 188                 return 0;
 189         default:
 190                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 191                 return -E_ADDRESS_LOOKUP;
 192         }
 193 err:
 194         return -ERRNO_TO_PARA_ERROR(errno);
 195 }
 196
 197 static int udp_recv_open(struct receiver_node *rn)
 198 {
 199         struct private_udp_recv_data *purd;
 200         struct udp_recv_args_info *c = rn->conf;
 201         char  *iface = c->iface_given ? c->iface_arg : NULL;
 202         int ret;
 203
 204         rn->private_data = para_calloc(sizeof(struct private_udp_recv_data));
 205         purd = rn->private_data;
 206
 207         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 208         if (ret < 0)
 209                 goto err;
 210         purd->fd = ret;
 211
 212         ret = mcast_receiver_setup(purd->fd, iface);
 213         if (ret < 0) {
 214                 close(purd->fd);
 215                 goto err;
 216         }
 217
 218         ret = mark_fd_nonblocking(purd->fd);
 219         if (ret < 0) {
 220                 close(purd->fd);
 221                 goto err;
 222         }
 223         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 224                 c->port_arg, purd->fd);
 225         purd->btrp = btr_pool_new("udp_recv", 320 * 1024);
 226         return purd->fd;
 227 err:
 228         free(rn->private_data);
 229         return ret;
 230 }
 231
 232 static void udp_recv_free_config(void *conf)
 233 {
 234         udp_recv_cmdline_parser_free(conf);
 235         free(conf);
 236 }
 237
 238 /**
 239  * The init function of the udp receiver.
 240  *
 241  * \param r Pointer to the receiver struct to initialize.
 242  *
 243  * Initialize all function pointers of \a r.
 244  */
 245 void udp_recv_init(struct receiver *r)
 246 {
 247         struct udp_recv_args_info dummy;
 248
 249         udp_recv_cmdline_parser_init(&dummy);
 250         r->open = udp_recv_open;
 251         r->close = udp_recv_close;
 252         r->pre_select = udp_recv_pre_select;
 253         r->post_select = udp_recv_post_select;
 254         r->parse_config = udp_recv_parse_config;
 255         r->free_config = udp_recv_free_config;
 256         r->help = (struct ggo_help) {
 257                 .short_help = udp_recv_args_info_help,
 258                 .detailed_help = udp_recv_args_info_detailed_help
 259         };
 260         udp_recv_cmdline_parser_free(&dummy);
 261 }