udp_recv.c

   1 /*
   2  * Copyright (C) 2005-2013 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 int 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                 btr_remove_node(&rn->btrn);
  88                 close(rn->fd);
  89                 rn->fd = -1;
  90         }
  91         return ret;
  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         struct udp_recv_args_info *tmp = para_calloc(sizeof(*tmp));
 104         udp_recv_cmdline_parser(argc, argv, tmp);
 105         return tmp;
 106 }
 107
 108 /*
 109  * Perform AF-independent joining of multicast receive addresses.
 110  *
 111  * \param fd    Bound socket descriptor.
 112  * \param iface The receiving multicast interface, or NULL for the default.
 113  *
 114  * \return Zero if okay, negative on error.
 115  */
 116 static int mcast_receiver_setup(int fd, const char *iface)
 117 {
 118         struct sockaddr_storage ss;
 119         socklen_t sslen = sizeof(ss);
 120         int id = iface == NULL ? 0 : if_nametoindex(iface);
 121
 122         if (getsockname(fd, (struct sockaddr *)&ss, &sslen) < 0)
 123                 goto err;
 124         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 125
 126         if (iface != NULL && id == 0)
 127                 PARA_WARNING_LOG("could not resolve interface %s, using default\n",
 128                         iface);
 129
 130         switch (ss.ss_family) {
 131         case AF_INET:
 132                 if (IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr))) {
 133 #ifdef HAVE_IP_MREQN
 134                         struct ip_mreqn m4;
 135
 136                         m4.imr_address.s_addr   = INADDR_ANY;
 137                         m4.imr_ifindex          = id;
 138 #else
 139                         struct ip_mreq m4;
 140
 141                         m4.imr_interface.s_addr = INADDR_ANY;
 142                         if (id != 0)
 143                                 PARA_ERROR_LOG("Setting IPv4 receiver mcast interface not supported\n");
 144
 145 #endif
 146                         m4.imr_multiaddr = ((struct sockaddr_in *)&ss)->sin_addr;
 147
 148                         if (setsockopt(fd, IPPROTO_IP, IP_ADD_MEMBERSHIP,
 149                                         &m4, sizeof(m4)) < 0)
 150                                 break;
 151                 }
 152                 return 0;
 153         case AF_INET6:
 154                 if (IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr)) {
 155                         struct ipv6_mreq m6;
 156
 157                         memset(&m6, 0, sizeof(m6));
 158                         memcpy(&m6.ipv6mr_multiaddr, &((struct sockaddr_in6 *)&ss)->sin6_addr, 16);
 159                         m6.ipv6mr_interface = id;
 160                         if (setsockopt(fd, IPPROTO_IPV6, IPV6_JOIN_GROUP, &m6, sizeof(m6)) < 0)
 161                                 break;
 162                 }
 163                 return 0;
 164         }
 165 err:
 166         return -ERRNO_TO_PARA_ERROR(errno);
 167 }
 168
 169 static int udp_recv_open(struct receiver_node *rn)
 170 {
 171         struct udp_recv_args_info *c = rn->conf;
 172         char  *iface = c->iface_given ? c->iface_arg : NULL;
 173         int ret;
 174
 175         ret = makesock(IPPROTO_UDP, 1, c->host_arg, c->port_arg, NULL);
 176         if (ret < 0)
 177                 goto err;
 178         rn->fd = ret;
 179
 180         ret = mcast_receiver_setup(rn->fd, iface);
 181         if (ret < 0) {
 182                 close(rn->fd);
 183                 goto err;
 184         }
 185
 186         ret = mark_fd_nonblocking(rn->fd);
 187         if (ret < 0) {
 188                 close(rn->fd);
 189                 goto err;
 190         }
 191         PARA_INFO_LOG("receiving from %s:%d, fd=%d\n", c->host_arg,
 192                 c->port_arg, rn->fd);
 193         rn->btrp = btr_pool_new("udp_recv", 320 * 1024);
 194         return rn->fd;
 195 err:
 196         return ret;
 197 }
 198
 199 static void udp_recv_free_config(void *conf)
 200 {
 201         udp_recv_cmdline_parser_free(conf);
 202         free(conf);
 203 }
 204
 205 /**
 206  * The init function of the udp receiver.
 207  *
 208  * \param r Pointer to the receiver struct to initialize.
 209  *
 210  * Initialize all function pointers of \a r.
 211  */
 212 void udp_recv_init(struct receiver *r)
 213 {
 214         struct udp_recv_args_info dummy;
 215
 216         udp_recv_cmdline_parser_init(&dummy);
 217         r->open = udp_recv_open;
 218         r->close = udp_recv_close;
 219         r->pre_select = udp_recv_pre_select;
 220         r->post_select = udp_recv_post_select;
 221         r->parse_config = udp_recv_parse_config;
 222         r->free_config = udp_recv_free_config;
 223         r->help = (struct ggo_help) {
 224                 .short_help = udp_recv_args_info_help,
 225                 .detailed_help = udp_recv_args_info_detailed_help
 226         };
 227         udp_recv_cmdline_parser_free(&dummy);
 228 }