udp_send.c

   1 /*
   2  * Copyright (C) 2005-2010 Andre Noll <maan@systemlinux.org>
   3  *
   4  * Licensed under the GPL v2. For licencing details see COPYING.
   5  */
   6
   7 /** \file udp_send.c Para_server's udp sender. */
   8
   9
  10 #include <regex.h>
  11 #include <sys/time.h>
  12 #include <dirent.h>
  13 #include <sys/socket.h>
  14 #include <netinet/udp.h>
  15 #include <net/if.h>
  16 #include <osl.h>
  17
  18 #include "server.cmdline.h"
  19 #include "para.h"
  20 #include "error.h"
  21 #include "string.h"
  22 #include "afh.h"
  23 #include "afs.h"
  24 #include "server.h"
  25 #include "list.h"
  26 #include "send.h"
  27 #include "vss.h"
  28 #include "portable_io.h"
  29 #include "net.h"
  30 #include "fd.h"
  31 #include "sched.h"
  32 #include "close_on_fork.h"
  33 #include "chunk_queue.h"
  34
  35 /**
  36  * Time window during which ICMP Destination/Port Unreachable messages are
  37  * ignored, covering transient receiver problems such as restarting the
  38  * client, rebooting, reconfiguration, or handover.
  39  */
  40 #define UDP_MAX_UNREACHABLE_TIME 30
  41
  42 /** Describes one entry in the list of targets for the udp sender. */
  43 struct udp_target {
  44         /** The hostname (DNS name or IPv4/v6 address string). */
  45         char host[MAX_HOSTLEN];
  46         /** The UDP port. */
  47         int port;
  48         /** Track time (seconds) of last ICMP Port Unreachable error */
  49         time_t last_unreachable;
  50         /** Common sender client data */
  51         struct sender_client *sc;
  52         /** The opaque structure returned by vss_add_fec_client(). */
  53         struct fec_client *fc;
  54         /** The FEC parameters for this target. */
  55         struct fec_client_parms fcp;
  56 };
  57
  58 static struct list_head targets;
  59 static int sender_status;
  60
  61 static void udp_close_target(struct sender_client *sc)
  62 {
  63         if (sc->cq != NULL) {
  64                 del_close_on_fork_list(sc->fd);
  65                 cq_destroy(sc->cq);
  66                 free(sc->name);
  67                 sc->name = NULL;
  68                 sc->cq = NULL;
  69
  70         }
  71 }
  72
  73 static void udp_delete_target(struct udp_target *ut, const char *msg)
  74 {
  75
  76         PARA_NOTICE_LOG("deleting %s#%d (%s) from list\n", ut->host,
  77                 ut->port, msg);
  78         udp_close_target(ut->sc);
  79         vss_del_fec_client(ut->fc);
  80         list_del(&ut->sc->node);
  81         free(ut->sc);
  82         free(ut);
  83 }
  84
  85 /**
  86  * Perform AF-independent multicast sender setup.
  87  *
  88  * \param sc    The connected sender client.
  89  *
  90  * \return Zero if okay, negative on error.
  91  */
  92 static int mcast_sender_setup(struct sender_client *sc)
  93 {
  94         struct sockaddr_storage ss;
  95         socklen_t sslen = sizeof(ss);
  96         int ttl = conf.udp_ttl_arg, id = 0;
  97         const int on = 1;
  98
  99         if (conf.udp_mcast_iface_given) {
 100                 char *iface = conf.udp_mcast_iface_arg;
 101
 102                 id = if_nametoindex(iface);
 103                 if (id == 0)
 104                         PARA_WARNING_LOG("could not resolve interface '%s', "
 105                                         "using default", iface);
 106         }
 107
 108         if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
 109                 goto err;
 110
 111         /* RFC 3493, 5.2: -1 means 'use kernel default' */
 112         if (ttl < 0 || ttl > 255)
 113                 ttl = -1;
 114
 115         switch (ss.ss_family) {
 116         case AF_INET:
 117                 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
 118                         return 0;
 119                 if (id != 0) {
 120 #ifdef HAVE_IP_MREQN
 121                         struct ip_mreqn mn;
 122
 123                         memset(&mn, 0, sizeof(mn));
 124                         mn.imr_ifindex = id;
 125                         if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
 126                                 goto err;
 127 #else
 128                         PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
 129 #endif
 130                 }
 131                 /*
 132                  * Enable receiving multicast messages generated on the local host
 133                  * At least on Linux, this is enabled by default.
 134                  */
 135                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 136                         break;
 137
 138                 /* Default: use local subnet (do not flood out into the WAN) */
 139                 if (ttl == -1)
 140                         ttl = 1;
 141                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 142                         break;
 143                 return 0;
 144         case AF_INET6:
 145                 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
 146                         return 0;
 147                 if (id != 0 &&
 148                     setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
 149                         break;
 150                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 151                         break;
 152                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 153                         break;
 154                 return 0;
 155         default:
 156                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 157                 return -E_ADDRESS_LOOKUP;
 158         }
 159 err:
 160         return -ERRNO_TO_PARA_ERROR(errno);
 161 }
 162
 163 /** The maximal size of the per-target chunk queue. */
 164 #define UDP_CQ_BYTES 40000
 165
 166 static void udp_init_session(struct sender_client *sc)
 167 {
 168         if (sc->cq == NULL) {
 169                 add_close_on_fork_list(sc->fd);
 170                 sc->cq   = cq_new(UDP_CQ_BYTES);
 171                 sc->name = para_strdup(remote_name(sc->fd));
 172                 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
 173         }
 174 }
 175
 176 static void udp_shutdown_targets(void)
 177 {
 178         struct sender_client *sc, *tmp;
 179         const char *buf;
 180         size_t len = vss_get_fec_eof_packet(&buf);
 181
 182         list_for_each_entry_safe(sc, tmp, &targets, node)
 183                 if (sc->cq != NULL) {
 184                         /* ignore return value, closing the target anyway. */
 185                         (void)write(sc->fd, buf, len);
 186                         udp_close_target(sc);
 187                 }
 188 }
 189
 190 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
 191 {
 192         const char *result;
 193         int ret, port;
 194
 195         ret = parse_fec_url(url, scd);
 196         if (ret)
 197                 return ret;
 198         port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
 199
 200         ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
 201         if (ret < 0)
 202                 return ret;
 203
 204         result = remote_name(ret);
 205         close(ret);
 206
 207         if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
 208                 return -E_ADDRESS_LOOKUP;
 209         return 1;
 210 }
 211
 212 static int udp_com_on(__a_unused struct sender_command_data *scd)
 213 {
 214         sender_status = SENDER_ON;
 215         return 1;
 216 }
 217
 218 static int udp_com_off(__a_unused struct sender_command_data *scd)
 219 {
 220         udp_shutdown_targets();
 221         sender_status = SENDER_OFF;
 222         return 1;
 223 }
 224
 225 static int udp_com_delete(struct sender_command_data *scd)
 226 {
 227         struct sender_client *sc, *tmp;
 228
 229         list_for_each_entry_safe(sc, tmp, &targets, node) {
 230                 struct udp_target *ut = sc->private_data;
 231
 232                 /* Unspecified port means wildcard port match */
 233                 if (scd->port > 0 && scd->port != ut->port)
 234                         continue;
 235                 if (strcmp(ut->host, scd->host))
 236                         continue;
 237                 udp_delete_target(ut, "com_delete");
 238         }
 239         return 1;
 240 }
 241
 242 /** Initialize UDP session and set maximum payload size. */
 243 static int udp_init_fec(struct sender_client *sc)
 244 {
 245         int mps;
 246
 247         udp_init_session(sc);
 248         mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
 249         PARA_INFO_LOG("current MPS = %d bytes\n", mps);
 250         return mps;
 251 }
 252
 253 /** Check and clear socket error if any. */
 254 static int udp_check_socket_state(struct udp_target *ut)
 255 {
 256         int ret;
 257         socklen_t errlen = sizeof(ret);
 258
 259         if (getsockopt(ut->sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
 260                 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
 261                 return 0;
 262         } else if (ret == 0) {
 263                 return 0;
 264         } else if (ret == ECONNREFUSED) {
 265                 time_t dist = now->tv_sec - ut->last_unreachable;
 266
 267                 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
 268                         return 0;
 269                 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
 270                         ut->last_unreachable = now->tv_sec;
 271                         return 0;
 272                 } else {
 273                         /*
 274                          * unreachable_time < dist <= 2 * unreachable_time
 275                          * No errors are allowed during this time window.
 276                          */
 277                         PARA_NOTICE_LOG("Evicting %s#%d after %d seconds "
 278                                         "of connection errors.\n",
 279                                         ut->host, ut->port, (int)dist);
 280                 }
 281         }
 282         return -ERRNO_TO_PARA_ERROR(ret);
 283 }
 284
 285 static int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
 286 {
 287         struct udp_target *ut = sc->private_data;
 288         int ret;
 289
 290         if (sender_status == SENDER_OFF)
 291                 return 0;
 292         if (len == 0 && !cq_peek(ut->sc->cq))
 293                 return 0;
 294         ret = udp_check_socket_state(ut);
 295         if (ret < 0)
 296                 goto fail;
 297         ret = send_queued_chunks(sc->fd, sc->cq);
 298         if (ret < 0)
 299                 goto fail;
 300         if (!ret) { /* still data left in the queue */
 301                 ret = cq_force_enqueue(sc->cq, buf, len);
 302                 assert(ret >= 0);
 303                 return 0;
 304         }
 305         ret = write_nonblock(sc->fd, buf, len);
 306         if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
 307                 /*
 308                  * Happens if meanwhile an ICMP Destination / Port Unreachable
 309                  * has arrived. Ignore, persistent errors will be caught above.
 310                  */
 311                 ret = 0;
 312         }
 313         if (ret < 0)
 314                 goto fail;
 315         if (ret != len) {
 316                 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
 317                 assert(ret >= 0);
 318         }
 319         return 1;
 320 fail:
 321         udp_delete_target(ut, para_strerror(-ret));
 322         return ret;
 323 }
 324
 325 static void udp_add_target(struct sender_command_data *scd)
 326 {
 327         int ret;
 328         struct udp_target *ut = para_calloc(sizeof(*ut));
 329
 330         ut->fcp.slices_per_group      = scd->slices_per_group;
 331         ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 332         ut->fcp.max_slice_bytes       = scd->max_slice_bytes;
 333         ut->fcp.init_fec              = udp_init_fec;
 334         ut->fcp.send_fec              = udp_send_fec;
 335
 336         ut->sc = para_calloc(sizeof(*ut->sc));
 337         ut->sc->private_data = ut;
 338         ut->sc->fd = -1;
 339         ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
 340         if (ret < 0)
 341                 goto err;
 342         ut->sc->fd = ret;
 343
 344         ret = mcast_sender_setup(ut->sc);
 345         if (ret < 0)
 346                 goto err;
 347         ret = mark_fd_nonblocking(ut->sc->fd);
 348         if (ret < 0)
 349                 goto err;
 350         PARA_INFO_LOG("adding to target list (%s#%d)\n", ut->host, ut->port);
 351         ut->fc = vss_add_fec_client(ut->sc, &ut->fcp);
 352         para_list_add(&ut->sc->node, &targets);
 353         return;
 354 err:
 355         if (ut->sc->fd >= 0)
 356                 close(ut->sc->fd);
 357         PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
 358                         scd->host, scd->port, para_strerror(-ret));
 359         free(ut->sc);
 360         free(ut);
 361 }
 362
 363 static int udp_com_add(struct sender_command_data *scd)
 364 {
 365         udp_add_target(scd);
 366         return 1;
 367 }
 368
 369 static char *udp_info(void)
 370 {
 371         struct sender_client *sc;
 372         char *ret, *tgts = NULL;
 373
 374         list_for_each_entry(sc, &targets, node) {
 375                 struct udp_target *ut = sc->private_data;
 376                 bool is_v6 = strchr(ut->host, ':') != NULL;
 377                 char *tmp = make_message("%s%s%s%s:%d/%u:%u:%u ", tgts ? : "",
 378                         is_v6 ? "[" : "", ut->host,
 379                         is_v6 ? "]" : "", ut->port,
 380                         ut->fcp.max_slice_bytes,
 381                         ut->fcp.data_slices_per_group,
 382                         ut->fcp.slices_per_group
 383                 );
 384                 free(tgts);
 385                 tgts = tmp;
 386         }
 387         ret = make_message(
 388                 "udp sender:\n"
 389                 "\tstatus: %s\n"
 390                 "\tport: %s\n"
 391                 "\ttargets: %s\n",
 392                 (sender_status == SENDER_ON)? "on" : "off",
 393                 stringify_port(conf.udp_default_port_arg, "udp"),
 394                 tgts? tgts : "(none)"
 395         );
 396         free(tgts);
 397         return ret;
 398 }
 399
 400 static void udp_init_target_list(void)
 401 {
 402         struct sender_command_data scd;
 403         int i;
 404
 405         INIT_LIST_HEAD(&targets);
 406         for (i = 0; i < conf.udp_target_given; i++) {
 407                 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
 408                         PARA_CRIT_LOG("not adding requested target '%s'\n",
 409                                         conf.udp_target_arg[i]);
 410                 else
 411                         udp_add_target(&scd);
 412         }
 413 }
 414
 415 static char *udp_help(void)
 416 {
 417         return make_message(
 418                 "usage: {on|off}\n"
 419                 "usage: {add|delete} host[:port][/packet_size:k:n]\n"
 420                 "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
 421                 "          add 224.0.1.38:1500/1400:14:16\n"
 422                 "              (likewise, using 1400 byte packets, with 14\n"
 423                 "               data slices per 16 slice FEC group)\n"
 424                 "          add 10.10.1.42       (using default port)\n"
 425                 "          add [FF05::42]:1500  (IPv6 multicast)\n"
 426                 "          add [::1]            (IPv6 localhost/default port)\n"
 427                 "          delete myhost.net    (host with port wildcard)\n"
 428                 "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
 429         );
 430 }
 431
 432 /**
 433  * The init function of para_server's udp sender.
 434  *
 435  * \param s Pointer to the udp sender struct.
 436  *
 437  * It initializes all function pointers of \a s and the list of udp targets.
 438  */
 439 void udp_send_init(struct sender *s)
 440 {
 441         INIT_LIST_HEAD(&targets);
 442         s->info = udp_info;
 443         s->help = udp_help;
 444         s->send = NULL;
 445         s->pre_select = NULL;
 446         s->post_select = NULL;
 447         s->shutdown_clients = udp_shutdown_targets;
 448         s->resolve_target = udp_resolve_target;
 449         s->client_cmds[SENDER_ON] = udp_com_on;
 450         s->client_cmds[SENDER_OFF] = udp_com_off;
 451         s->client_cmds[SENDER_DENY] = NULL;
 452         s->client_cmds[SENDER_ALLOW] = NULL;
 453         s->client_cmds[SENDER_ADD] = udp_com_add;
 454         s->client_cmds[SENDER_DELETE] = udp_com_delete;
 455         sender_status = SENDER_OFF;
 456         udp_init_target_list();
 457         if (!conf.udp_no_autostart_given)
 458                 sender_status = SENDER_ON;
 459         PARA_DEBUG_LOG("udp sender init complete\n");
 460 }