udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2012 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 "buffer_tree.h"
  19 #include "recv.h"
  20 #include "udp_recv.cmdline.h"
  21 #include "string.h"
  22 #include "net.h"
  23 #include "fd.h"
  24
  25 static void udp_recv_pre_select(struct sched *s, struct task *t)
  26 {
  27         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  28
  29         if (generic_recv_pre_select(s, t) <= 0)
  30                 return;
  31         para_fd_set(rn->fd, &s->rfds, &s->max_fileno);
  32 }
  33
  34 static int udp_check_eof(size_t sz, struct iovec iov[2])
  35 {
  36         if (sz < FEC_EOF_PACKET_LEN)
  37                 return 0;
  38         if (iov[0].iov_len >= FEC_EOF_PACKET_LEN) {
  39                 if (memcmp(iov[0].iov_base, FEC_EOF_PACKET,
  40                                 FEC_EOF_PACKET_LEN) != 0)
  41                         return 0;
  42                 return -E_RECV_EOF;
  43         }
  44         if (memcmp(iov[0].iov_base, FEC_EOF_PACKET, iov[0].iov_len) != 0)
  45                 return 0;
  46         if (memcmp(iov[1].iov_base, FEC_EOF_PACKET + iov[0].iov_len,
  47                         FEC_EOF_PACKET_LEN - iov[0].iov_len) != 0)
  48                 return 0;
  49         return -E_RECV_EOF;
  50 }
  51
  52 static void udp_recv_post_select(__a_unused struct sched *s, struct task *t)
  53 {
  54         struct receiver_node *rn = container_of(t, struct receiver_node, task);
  55         struct btr_node *btrn = rn->btrn;
  56         size_t num_bytes;
  57         struct iovec iov[2];
  58         int ret, readv_ret, iovcnt;
  59
  60         ret = task_get_notification(t);
  61         if (ret < 0)
  62                 goto out;
  63         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  64         if (ret <= 0)
  65                 goto out;
  66         iovcnt = btr_pool_get_buffers(rn->btrp, iov);
  67         ret = -E_UDP_OVERRUN;
  68         if (iovcnt == 0)
  69                 goto out;
  70         ret = readv_nonblock(rn->fd, iov, iovcnt, &s->rfds, &num_bytes);
  71         if (num_bytes == 0)
  72                 goto out;
  73         readv_ret = ret;
  74         ret = udp_check_eof(num_bytes, iov);
  75         if (ret < 0)
  76                 goto out;
  77         if (iov[0].iov_len >= num_bytes)
  78                 btr_add_output_pool(rn->btrp, num_bytes, btrn);
  79         else { /* both buffers contain data */
  80                 btr_add_output_pool(rn->btrp, iov[0].iov_len, btrn);
  81                 btr_add_output_pool(rn->btrp, num_bytes - iov[0].iov_len,
  82                         btrn);
  83         }
  84         ret = readv_ret;
  85 out:
  86         if (ret >= 0)
  87                 return;
  88         btr_remove_node(&rn->btrn);
  89         t->error = ret;
  90         close(rn->fd);
  91         rn->fd = -1;
  92 }
  93
  94 static void udp_recv_close(struct receiver_node *rn)
  95 {
  96         if (rn->fd >= 0)
  97                 close(rn->fd);
  98         btr_pool_free(rn->btrp);
  99 }
 100
 101 static void *udp_recv_parse_config(int argc, char **argv)
 102 {
 103         int ret;
 104         struct udp_recv_args_info *tmp =
 105                 para_calloc(sizeof(struct udp_recv_args_info));
 106
 107         ret = udp_recv_cmdline_parser(argc, argv, tmp)? -E_UDP_SYNTAX : 1;
 108         if (ret >= 0)
 109                 return tmp;
 110         free(tmp);
 111         return NULL;
 112 }
 113
 114 /*
 115  * Perform AF-independent joining of multicast receive addresses.
 116  *
 117  * \param fd    Bound socket descriptor.
 118  * \param iface The receiving multicast interface, or NULL for the default.
 119  *
 120  * \return Zero if okay, negative on error.
 121  */
 122 static int mcast_receiver_setup(int fd, const char *iface)
 123 {
 124         struct sockaddr_storage ss;
 125         socklen_t sslen = sizeof(ss);
 126         int id = iface == NULL ? 0 : if_nametoindex(iface);
 127
 128         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 129                 goto err;
 130         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 131
 132         if (iface != NULL && id == 0)
 133                 PARA_WARNING_LOG("could not resolve interface %s, using default\n",
 134                         iface);
 135
 136         switch (ss.ss_family) {
 137         case AF_INET:
 138                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 139 #ifdef HAVE_IP_MREQN
 140                         struct ip_mreqn m4;
 141
 142                         m4.imr_address.s_addr   = INADDR_ANY;
 143                         m4.imr_ifindex          = id;
 144 #else
 145                         struct ip_mreq m4;
 146
 147                         m4.imr_interface.s_addr = INADDR_ANY;
 148                         if (id != 0)
 149                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported\n");
 150
 151 #endif
 152                         m4.imr_multiaddr = ((struct sockaddr_in *)&ss)->sin_addr;
 153
 154                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 155                                         &m4, sizeof(m4)) < 0)
 156                                 break;
 157                 }
 158                 return 0;
 159         case AF_INET6:
 160                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 161                         struct ipv6_mreq m6;
 162
 163                         memset(&m6, 0, sizeof(m6));
 164                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 165                         m6.ipv6mr_interface = id;
 166                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 167                                 break;
 168                 }
 169                 return 0;
 170         }
 171 err:
 172         return -ERRNO_TO_PARA_ERROR(errno);
 173 }
 174
 175 static int udp_recv_open(struct receiver_node *rn)
 176 {
 177         struct udp_recv_args_info *c = rn->conf;
 178         char  *iface = c->iface_given ? c->iface_arg : NULL;
 179         int ret;
 180
 181         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 182         if (ret < 0)
 183                 goto err;
 184         rn->fd = ret;
 185
 186         ret = mcast_receiver_setup(rn->fd, iface);
 187         if (ret < 0) {
 188                 close(rn->fd);
 189                 goto err;
 190         }
 191
 192         ret = mark_fd_nonblocking(rn->fd);
 193         if (ret < 0) {
 194                 close(rn->fd);
 195                 goto err;
 196         }
 197         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 198                 c->port_arg, rn->fd);
 199         rn->btrp = btr_pool_new("udp_recv", 320 * 1024);
 200         return rn->fd;
 201 err:
 202         return ret;
 203 }
 204
 205 static void udp_recv_free_config(void *conf)
 206 {
 207         udp_recv_cmdline_parser_free(conf);
 208         free(conf);
 209 }
 210
 211 /**
 212  * The init function of the udp receiver.
 213  *
 214  * \param r Pointer to the receiver struct to initialize.
 215  *
 216  * Initialize all function pointers of \a r.
 217  */
 218 void udp_recv_init(struct receiver *r)
 219 {
 220         struct udp_recv_args_info dummy;
 221
 222         udp_recv_cmdline_parser_init(&dummy);
 223         r->open = udp_recv_open;
 224         r->close = udp_recv_close;
 225         r->pre_select = udp_recv_pre_select;
 226         r->post_select = udp_recv_post_select;
 227         r->parse_config = udp_recv_parse_config;
 228         r->free_config = udp_recv_free_config;
 229         r->help = (struct ggo_help) {
 230                 .short_help = udp_recv_args_info_help,
 231                 .detailed_help = udp_recv_args_info_detailed_help
 232         };
 233         udp_recv_cmdline_parser_free(&dummy);
 234 }