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