udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2014 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 <netinet/in.h>
   9 #include <regex.h>
  10 #include <sys/socket.h>
  11 #include <net/if.h>
  12 #include <sys/types.h>
  13 #include <arpa/inet.h>
  14 #include <sys/un.h>
  15 #include <netdb.h>
  16
  17 #include "para.h"
  18 #include "error.h"
  19 #include "portable_io.h"
  20 #include "list.h"
  21 #include "sched.h"
  22 #include "ggo.h"
  23 #include "buffer_tree.h"
  24 #include "recv.h"
  25 #include "udp_recv.cmdline.h"
  26 #include "string.h"
  27 #include "net.h"
  28 #include "fd.h"
  29
  30 static void udp_recv_pre_select(struct sched *s, void *context)
  31 {
  32         struct receiver_node *rn = context;
  33
  34         if (generic_recv_pre_select(s, rn) <= 0)
  35                 return;
  36         para_fd_set(rn->fd, &s->rfds, &s->max_fileno);
  37 }
  38
  39 static int udp_check_eof(size_t sz, struct iovec iov[2])
  40 {
  41         if (sz < FEC_EOF_PACKET_LEN)
  42                 return 0;
  43         if (iov[0].iov_len >= FEC_EOF_PACKET_LEN) {
  44                 if (memcmp(iov[0].iov_base, FEC_EOF_PACKET,
  45                                 FEC_EOF_PACKET_LEN) != 0)
  46                         return 0;
  47                 return -E_RECV_EOF;
  48         }
  49         if (memcmp(iov[0].iov_base, FEC_EOF_PACKET, iov[0].iov_len) != 0)
  50                 return 0;
  51         if (memcmp(iov[1].iov_base, &FEC_EOF_PACKET[iov[0].iov_len],
  52                         FEC_EOF_PACKET_LEN - iov[0].iov_len) != 0)
  53                 return 0;
  54         return -E_RECV_EOF;
  55 }
  56
  57 static int udp_recv_post_select(__a_unused struct sched *s, void *context)
  58 {
  59         struct receiver_node *rn = context;
  60         struct btr_node *btrn = rn->btrn;
  61         size_t num_bytes;
  62         struct iovec iov[2];
  63         int ret, readv_ret, iovcnt;
  64
  65         ret = task_get_notification(rn->task);
  66         if (ret < 0)
  67                 goto out;
  68         ret = btr_node_status(btrn, 0, BTR_NT_ROOT);
  69         if (ret <= 0)
  70                 goto out;
  71         iovcnt = btr_pool_get_buffers(rn->btrp, iov);
  72         ret = -E_UDP_OVERRUN;
  73         if (iovcnt == 0)
  74                 goto out;
  75         ret = readv_nonblock(rn->fd, iov, iovcnt, &s->rfds, &num_bytes);
  76         if (num_bytes == 0)
  77                 goto out;
  78         readv_ret = ret;
  79         ret = udp_check_eof(num_bytes, iov);
  80         if (ret < 0)
  81                 goto out;
  82         if (iov[0].iov_len >= num_bytes)
  83                 btr_add_output_pool(rn->btrp, num_bytes, btrn);
  84         else { /* both buffers contain data */
  85                 btr_add_output_pool(rn->btrp, iov[0].iov_len, btrn);
  86                 btr_add_output_pool(rn->btrp, num_bytes - iov[0].iov_len,
  87                         btrn);
  88         }
  89         ret = readv_ret;
  90 out:
  91         if (ret < 0) {
  92                 btr_remove_node(&rn->btrn);
  93                 close(rn->fd);
  94                 rn->fd = -1;
  95         }
  96         return ret;
  97 }
  98
  99 static void udp_recv_close(struct receiver_node *rn)
 100 {
 101         if (rn->fd >= 0)
 102                 close(rn->fd);
 103         btr_pool_free(rn->btrp);
 104 }
 105
 106 static void *udp_recv_parse_config(int argc, char **argv)
 107 {
 108         struct udp_recv_args_info *tmp = para_calloc(sizeof(*tmp));
 109         udp_recv_cmdline_parser(argc, argv, tmp);
 110         return tmp;
 111 }
 112
 113 /*
 114  * Perform AF-independent joining of multicast receive addresses.
 115  *
 116  * \param fd    Bound socket descriptor.
 117  * \param iface The receiving multicast interface, or NULL for the default.
 118  *
 119  * \return Zero if okay, negative on error.
 120  */
 121 static int mcast_receiver_setup(int fd, const char *iface)
 122 {
 123         struct sockaddr_storage ss;
 124         socklen_t sslen = sizeof(ss);
 125         int id = iface == NULL ? 0 : if_nametoindex(iface);
 126
 127         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 128                 goto err;
 129         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 130
 131         if (iface != NULL && id == 0)
 132                 PARA_WARNING_LOG("could not resolve interface %s, using default\n",
 133                         iface);
 134
 135         switch (ss.ss_family) {
 136         case AF_INET:
 137                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 138 #ifdef HAVE_IP_MREQN
 139                         struct ip_mreqn m4;
 140
 141                         m4.imr_address.s_addr   = INADDR_ANY;
 142                         m4.imr_ifindex          = id;
 143 #else
 144                         struct ip_mreq m4;
 145
 146                         m4.imr_interface.s_addr = INADDR_ANY;
 147                         if (id != 0)
 148                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported\n");
 149
 150 #endif
 151                         m4.imr_multiaddr = ((struct sockaddr_in *)&ss)->sin_addr;
 152
 153                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 154                                         &m4, sizeof(m4)) < 0)
 155                                 break;
 156                 }
 157                 return 0;
 158         case AF_INET6:
 159                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 160                         struct ipv6_mreq m6;
 161
 162                         memset(&m6, 0, sizeof(m6));
 163                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 164                         m6.ipv6mr_interface = id;
 165                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 166                                 break;
 167                 }
 168                 return 0;
 169         }
 170 err:
 171         return -ERRNO_TO_PARA_ERROR(errno);
 172 }
 173
 174 static int udp_recv_open(struct receiver_node *rn)
 175 {
 176         struct udp_recv_args_info *c = rn->conf;
 177         char  *iface = c->iface_given ? c->iface_arg : NULL;
 178         int ret;
 179
 180         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 181         if (ret < 0)
 182                 goto err;
 183         rn->fd = ret;
 184
 185         ret = mcast_receiver_setup(rn->fd, iface);
 186         if (ret < 0) {
 187                 close(rn->fd);
 188                 goto err;
 189         }
 190
 191         ret = mark_fd_nonblocking(rn->fd);
 192         if (ret < 0) {
 193                 close(rn->fd);
 194                 goto err;
 195         }
 196         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 197                 c->port_arg, rn->fd);
 198         rn->btrp = btr_pool_new("udp_recv", 320 * 1024);
 199         return rn->fd;
 200 err:
 201         return ret;
 202 }
 203
 204 static void udp_recv_free_config(void *conf)
 205 {
 206         udp_recv_cmdline_parser_free(conf);
 207         free(conf);
 208 }
 209
 210 /**
 211  * The init function of the udp receiver.
 212  *
 213  * \param r Pointer to the receiver struct to initialize.
 214  *
 215  * Initialize all function pointers of \a r.
 216  */
 217 void udp_recv_init(struct receiver *r)
 218 {
 219         struct udp_recv_args_info dummy;
 220
 221         udp_recv_cmdline_parser_init(&dummy);
 222         r->open = udp_recv_open;
 223         r->close = udp_recv_close;
 224         r->pre_select = udp_recv_pre_select;
 225         r->post_select = udp_recv_post_select;
 226         r->parse_config = udp_recv_parse_config;
 227         r->free_config = udp_recv_free_config;
 228         r->help = (struct ggo_help)DEFINE_GGO_HELP(udp_recv);
 229         udp_recv_cmdline_parser_free(&dummy);
 230 }