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         struct timeval last_read_time;
  36 };
  37
  38 static void udp_recv_pre_select(struct sched *s, struct task *t)
  39 {
  40         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  41         struct private_udp_recv_data *purd = rn->private_data;
  42
  43         if (generic_recv_pre_select(s, t) <= 0)
  44                 return;
  45         para_fd_set(purd->fd, &s->rfds, &s->max_fileno);
  46 }
  47
  48 static int udp_check_eof(size_t sz, struct iovec iov[2])
  49 {
  50         if (sz < FEC_EOF_PACKET_LEN)
  51                 return 0;
  52         if (iov[0].iov_len >= FEC_EOF_PACKET_LEN) {
  53                 if (memcmp(iov[0].iov_base, FEC_EOF_PACKET,
  54                                 FEC_EOF_PACKET_LEN) != 0)
  55                         return 0;
  56                 return -E_RECV_EOF;
  57         }
  58         if (memcmp(iov[0].iov_base, FEC_EOF_PACKET, iov[0].iov_len) != 0)
  59                 return 0;
  60         if (memcmp(iov[1].iov_base, FEC_EOF_PACKET + iov[0].iov_len,
  61                         FEC_EOF_PACKET_LEN - iov[0].iov_len) != 0)
  62                 return 0;
  63         return -E_RECV_EOF;
  64 }
  65
  66 static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
  67 {
  68         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  69         struct private_udp_recv_data *purd = rn->private_data;
  70         struct btr_node *btrn = rn->btrn;
  71         size_t packet_size;
  72         struct iovec iov[2];
  73         int ret, iovcnt;
  74
  75         t->error = 0;
  76         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  77         if (ret < 0)
  78                 goto err;
  79         if (ret == 0)
  80                 return;
  81         if (!FD_ISSET(purd->fd, &s->rfds)) {
  82                 struct timeval tmp;
  83                 tv_add(&purd->last_read_time, &(struct timeval)EMBRACE(5, 0),
  84                         &tmp);
  85                 ret = -E_UDP_TIMEOUT;
  86                 if (tv_diff(now, &tmp, NULL) > 0)
  87                         goto err;
  88                 return;
  89         }
  90         iovcnt = btr_pool_get_buffers(purd->btrp, iov);
  91         ret = -E_UDP_OVERRUN;
  92         if (iovcnt == 0)
  93                 goto err;
  94         ret = para_readv(purd->fd, iov, iovcnt);
  95         /* EAGAIN is possible even if FD_ISSET */
  96         if (ret < 0 && is_errno(-ret, EAGAIN))
  97                 return;
  98         if (ret == 0)
  99                 ret = -E_RECV_EOF;
 100         if (ret < 0)
 101                 goto err;
 102         packet_size = ret;
 103         ret = udp_check_eof(packet_size, iov);
 104         if (ret < 0)
 105                 goto err;
 106         purd->last_read_time = *now;
 107         if (iov[0].iov_len >= packet_size)
 108                 btr_add_output_pool(purd->btrp, packet_size, btrn);
 109         else { /* both buffers contain data */
 110                 btr_add_output_pool(purd->btrp, iov[0].iov_len, btrn);
 111                 btr_add_output_pool(purd->btrp, packet_size - iov[0].iov_len,
 112                         btrn);
 113         }
 114         return;
 115 err:
 116         btr_remove_node(btrn);
 117         t->error = ret;
 118         close(purd->fd);
 119         purd->fd = -1;
 120 }
 121
 122 static void udp_recv_close(struct receiver_node *rn)
 123 {
 124         struct private_udp_recv_data *purd = rn->private_data;
 125
 126         if (purd->fd >= 0)
 127                 close(purd->fd);
 128         btr_pool_free(purd->btrp);
 129         free(rn->private_data);
 130 }
 131
 132 static void *udp_recv_parse_config(int argc, char **argv)
 133 {
 134         int ret;
 135         struct udp_recv_args_info *tmp =
 136                 para_calloc(sizeof(struct udp_recv_args_info));
 137
 138         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 139         if (ret >= 0)
 140                 return tmp;
 141         free(tmp);
 142         return NULL;
 143 }
 144
 145 /*
 146  * Perform AF-independent joining of multicast receive addresses.
 147  *
 148  * \param fd    Bound socket descriptor.
 149  * \param iface The receiving multicast interface, or NULL for the default.
 150  *
 151  * \return Zero if okay, negative on error.
 152  */
 153 static int mcast_receiver_setup(int fd, const char *iface)
 154 {
 155         struct sockaddr_storage ss;
 156         socklen_t sslen = sizeof(ss);
 157         int id = iface == NULL ? 0 : if_nametoindex(iface);
 158
 159         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 160                 goto err;
 161
 162         if (iface != NULL && id == 0)
 163                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
 164
 165         switch (ss.ss_family) {
 166         case AF_INET:
 167                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 168 #ifdef HAVE_IP_MREQN
 169                         struct ip_mreqn m4;
 170
 171                         m4.imr_address.s_addr   = INADDR_ANY;
 172                         m4.imr_ifindex          = id;
 173 #else
 174                         struct ip_mreq m4;
 175
 176                         m4.imr_interface.s_addr = INADDR_ANY;
 177                         if (id != 0)
 178                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported.");
 179
 180 #endif
 181                         m4.imr_multiaddr        = ((struct sockaddr_in *)&ss)->sin_addr;
 182
 183                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP, &m4, sizeof(m4)) < 0)
 184                                 break;
 185                 }
 186                 return 0;
 187         case AF_INET6:
 188                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 189                         struct ipv6_mreq m6;
 190
 191                         memset(&m6, 0, sizeof(m6));
 192                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 193                         m6.ipv6mr_interface = id;
 194                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 195                                 break;
 196                 }
 197                 return 0;
 198         default:
 199                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 200                 return -E_ADDRESS_LOOKUP;
 201         }
 202 err:
 203         return -ERRNO_TO_PARA_ERROR(errno);
 204 }
 205
 206 static int udp_recv_open(struct receiver_node *rn)
 207 {
 208         struct private_udp_recv_data *purd;
 209         struct udp_recv_args_info *c = rn->conf;
 210         char  *iface = c->iface_given ? c->iface_arg : NULL;
 211         int ret;
 212
 213         rn->private_data = para_calloc(sizeof(struct private_udp_recv_data));
 214         purd = rn->private_data;
 215
 216         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 217         if (ret < 0)
 218                 goto err;
 219         purd->fd = ret;
 220
 221         ret = mcast_receiver_setup(purd->fd, iface);
 222         if (ret < 0) {
 223                 close(purd->fd);
 224                 goto err;
 225         }
 226
 227         ret = mark_fd_nonblocking(purd->fd);
 228         if (ret < 0) {
 229                 close(purd->fd);
 230                 goto err;
 231         }
 232         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 233                 c->port_arg, purd->fd);
 234         purd->btrp = btr_pool_new("udp_recv", 320 * 1024);
 235         purd->last_read_time = *now;
 236         return purd->fd;
 237 err:
 238         free(rn->private_data);
 239         return ret;
 240 }
 241
 242 static void udp_recv_free_config(void *conf)
 243 {
 244         udp_recv_cmdline_parser_free(conf);
 245         free(conf);
 246 }
 247
 248 /**
 249  * The init function of the udp receiver.
 250  *
 251  * \param r Pointer to the receiver struct to initialize.
 252  *
 253  * Initialize all function pointers of \a r.
 254  */
 255 void udp_recv_init(struct receiver *r)
 256 {
 257         struct udp_recv_args_info dummy;
 258
 259         udp_recv_cmdline_parser_init(&dummy);
 260         r->open = udp_recv_open;
 261         r->close = udp_recv_close;
 262         r->pre_select = udp_recv_pre_select;
 263         r->post_select = udp_recv_post_select;
 264         r->parse_config = udp_recv_parse_config;
 265         r->free_config = udp_recv_free_config;
 266         r->help = (struct ggo_help) {
 267                 .short_help = udp_recv_args_info_help,
 268                 .detailed_help = udp_recv_args_info_detailed_help
 269         };
 270         udp_recv_cmdline_parser_free(&dummy);
 271 }