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         /** Track time (seconds) of last ICMP Port Unreachable error */
  45         time_t last_unreachable;
  46         /** Common sender client data */
  47         struct sender_client *sc;
  48         /** The opaque structure returned by vss_add_fec_client(). */
  49         struct fec_client *fc;
  50         /** The FEC parameters for this target. */
  51         struct fec_client_parms fcp;
  52 };
  53
  54 static struct list_head targets;
  55 static int sender_status;
  56
  57 static void udp_close_target(struct sender_client *sc)
  58 {
  59         if (sc->cq != NULL) {
  60                 del_close_on_fork_list(sc->fd);
  61                 cq_destroy(sc->cq);
  62                 sc->cq = NULL;
  63         }
  64 }
  65
  66 static void udp_delete_target(struct sender_client *sc, const char *msg)
  67 {
  68         struct udp_target *ut = sc->private_data;
  69
  70         PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
  71         udp_close_target(sc);
  72         vss_del_fec_client(ut->fc);
  73         list_del(&sc->node);
  74         free(sc->name);
  75         free(sc);
  76         free(ut);
  77 }
  78
  79 /**
  80  * Perform AF-independent multicast sender setup.
  81  *
  82  * \param sc    The connected sender client.
  83  *
  84  * \return Zero if okay, negative on error.
  85  */
  86 static int mcast_sender_setup(struct sender_client *sc)
  87 {
  88         struct sockaddr_storage ss;
  89         socklen_t sslen = sizeof(ss);
  90         int ttl = conf.udp_ttl_arg, id = 0;
  91         const int on = 1;
  92
  93         if (conf.udp_mcast_iface_given) {
  94                 char *iface = conf.udp_mcast_iface_arg;
  95
  96                 id = if_nametoindex(iface);
  97                 if (id == 0)
  98                         PARA_WARNING_LOG("could not resolve interface '%s', "
  99                                         "using default", iface);
 100         }
 101
 102         if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
 103                 goto err;
 104         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 105
 106         /* RFC 3493, 5.2: -1 means 'use kernel default' */
 107         if (ttl < 0 || ttl > 255)
 108                 ttl = -1;
 109
 110         switch (ss.ss_family) {
 111         case AF_INET:
 112                 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
 113                         return 0;
 114                 if (id != 0) {
 115 #ifdef HAVE_IP_MREQN
 116                         struct ip_mreqn mn;
 117
 118                         memset(&mn, 0, sizeof(mn));
 119                         mn.imr_ifindex = id;
 120                         if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
 121                                 goto err;
 122 #else
 123                         PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
 124 #endif
 125                 }
 126                 /*
 127                  * Enable receiving multicast messages generated on the local host
 128                  * At least on Linux, this is enabled by default.
 129                  */
 130                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 131                         break;
 132
 133                 /* Default: use local subnet (do not flood out into the WAN) */
 134                 if (ttl == -1)
 135                         ttl = 1;
 136                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 137                         break;
 138                 return 0;
 139         case AF_INET6:
 140                 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
 141                         return 0;
 142                 if (id != 0 &&
 143                     setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
 144                         break;
 145                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 146                         break;
 147                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 148                         break;
 149                 return 0;
 150         }
 151 err:
 152         return -ERRNO_TO_PARA_ERROR(errno);
 153 }
 154
 155 /** The maximal size of the per-target chunk queue. */
 156 #define UDP_CQ_BYTES 40000
 157
 158 static void udp_init_session(struct sender_client *sc)
 159 {
 160         if (sc->cq == NULL) {
 161                 sc->cq = cq_new(UDP_CQ_BYTES);
 162                 add_close_on_fork_list(sc->fd);
 163                 PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
 164         }
 165 }
 166
 167 static void udp_shutdown_targets(void)
 168 {
 169         struct sender_client *sc, *tmp;
 170         const char *buf;
 171         size_t len = vss_get_fec_eof_packet(&buf);
 172
 173         list_for_each_entry_safe(sc, tmp, &targets, node)
 174                 if (sc->cq != NULL) {
 175                         /* ignore return value, closing the target anyway. */
 176                         (void)write(sc->fd, buf, len);
 177                         udp_close_target(sc);
 178                 }
 179 }
 180
 181 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
 182 {
 183         const char *result;
 184         int ret, port;
 185
 186         ret = parse_fec_url(url, scd);
 187         if (ret)
 188                 return ret;
 189         port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
 190
 191         ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
 192         if (ret < 0)
 193                 return ret;
 194
 195         result = remote_name(ret);
 196         close(ret);
 197
 198         if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
 199                 return -E_ADDRESS_LOOKUP;
 200         return 1;
 201 }
 202
 203 static int udp_com_on(__a_unused struct sender_command_data *scd)
 204 {
 205         sender_status = SENDER_ON;
 206         return 1;
 207 }
 208
 209 static int udp_com_off(__a_unused struct sender_command_data *scd)
 210 {
 211         udp_shutdown_targets();
 212         sender_status = SENDER_OFF;
 213         return 1;
 214 }
 215
 216 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
 217 {
 218         struct sender_client *sc, *tmp;
 219         char host[MAX_HOSTLEN];
 220         int32_t port;
 221
 222         list_for_each_entry_safe(sc, tmp, &targets, node) {
 223                 parse_url(sc->name, host, sizeof(host), &port);
 224
 225                 /* Unspecified port means wildcard port match */
 226                 if (scd->port > 0 && scd->port != port)
 227                         continue;
 228                 if (strcmp(host, scd->host))
 229                         continue;
 230                 return sc;
 231         }
 232         return NULL;
 233 }
 234
 235 static int udp_com_delete(struct sender_command_data *scd)
 236 {
 237         struct sender_client *sc = udp_lookup_target(scd);
 238
 239         if (sc) {
 240                 udp_delete_target(sc, "com_delete");
 241                 return 1;
 242         }
 243         PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
 244         return -E_TARGET_NOT_FOUND;
 245 }
 246
 247 /** Initialize UDP session and set maximum payload size. */
 248 static int udp_init_fec(struct sender_client *sc)
 249 {
 250         int mps;
 251
 252         udp_init_session(sc);
 253         mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
 254         PARA_INFO_LOG("current MPS = %d bytes\n", mps);
 255         return mps;
 256 }
 257
 258 /** Check and clear socket error if any. */
 259 static int udp_check_socket_state(struct sender_client *sc)
 260 {
 261         struct udp_target *ut = sc->private_data;
 262         int ret;
 263         socklen_t errlen = sizeof(ret);
 264
 265         if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
 266                 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
 267                 return 0;
 268         } else if (ret == 0) {
 269                 return 0;
 270         } else if (ret == ECONNREFUSED) {
 271                 time_t dist = now->tv_sec - ut->last_unreachable;
 272
 273                 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
 274                         return 0;
 275                 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
 276                         ut->last_unreachable = now->tv_sec;
 277                         return 0;
 278                 } else {
 279                         /*
 280                          * unreachable_time < dist <= 2 * unreachable_time
 281                          * No errors are allowed during this time window.
 282                          */
 283                         PARA_NOTICE_LOG("Evicting %s after %d seconds "
 284                                         "of connection errors.\n",
 285                                         sc->name, (int)dist);
 286                 }
 287         }
 288         return -ERRNO_TO_PARA_ERROR(ret);
 289 }
 290
 291 static int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
 292 {
 293         int ret;
 294
 295         if (sender_status == SENDER_OFF)
 296                 return 0;
 297         if (len == 0 && !cq_peek(sc->cq))
 298                 return 0;
 299         ret = udp_check_socket_state(sc);
 300         if (ret < 0)
 301                 goto fail;
 302         ret = send_queued_chunks(sc->fd, sc->cq);
 303         if (ret < 0)
 304                 goto fail;
 305         if (!ret) { /* still data left in the queue */
 306                 ret = cq_force_enqueue(sc->cq, buf, len);
 307                 assert(ret >= 0);
 308                 return 0;
 309         }
 310         ret = write_nonblock(sc->fd, buf, len);
 311         if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
 312                 /*
 313                  * Happens if meanwhile an ICMP Destination / Port Unreachable
 314                  * has arrived. Ignore, persistent errors will be caught above.
 315                  */
 316                 ret = 0;
 317         }
 318         if (ret < 0)
 319                 goto fail;
 320         if (ret != len) {
 321                 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
 322                 assert(ret >= 0);
 323         }
 324         return 1;
 325 fail:
 326         udp_delete_target(sc, para_strerror(-ret));
 327         return ret;
 328 }
 329
 330 static int udp_com_add(struct sender_command_data *scd)
 331 {
 332         int ret;
 333         struct udp_target *ut;
 334         struct sender_client *sc = udp_lookup_target(scd);
 335
 336         if (sc) {
 337                 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
 338                                 sc->name);
 339                 return -E_TARGET_EXISTS;
 340         }
 341         ut = para_calloc(sizeof(*ut));
 342         sc = ut->sc = para_calloc(sizeof(*sc));
 343         ut->fcp.slices_per_group      = scd->slices_per_group;
 344         ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 345         ut->fcp.max_slice_bytes       = scd->max_slice_bytes;
 346         ut->fcp.init_fec              = udp_init_fec;
 347         ut->fcp.send_fec              = udp_send_fec;
 348
 349         sc->private_data = ut;
 350         sc->fd = -1;
 351         ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
 352         if (ret < 0)
 353                 goto err;
 354         sc->fd = ret;
 355
 356         ret = mcast_sender_setup(sc);
 357         if (ret < 0)
 358                 goto err;
 359         ret = mark_fd_nonblocking(sc->fd);
 360         if (ret < 0)
 361                 goto err;
 362         sc->name = para_strdup(remote_name(sc->fd));
 363         PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
 364         ut->fc = vss_add_fec_client(sc, &ut->fcp);
 365         para_list_add(&sc->node, &targets);
 366         return 1;
 367 err:
 368         if (sc->fd >= 0)
 369                 close(sc->fd);
 370         PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
 371                         scd->host, scd->port, para_strerror(-ret));
 372         free(sc);
 373         free(ut);
 374         return ret;
 375 }
 376
 377 static char *udp_info(void)
 378 {
 379         struct sender_client *sc;
 380         char *ret, *tgts = NULL;
 381
 382         list_for_each_entry(sc, &targets, node) {
 383                 struct udp_target *ut = sc->private_data;
 384                 char *tmp = make_message("%s%s/%u:%u:%u ",
 385                         tgts ? : "", sc->name,
 386                         ut->fcp.max_slice_bytes,
 387                         ut->fcp.data_slices_per_group,
 388                         ut->fcp.slices_per_group
 389                 );
 390                 free(tgts);
 391                 tgts = tmp;
 392         }
 393         ret = make_message(
 394                 "udp sender:\n"
 395                 "\tstatus: %s\n"
 396                 "\tport: %s\n"
 397                 "\ttargets: %s\n",
 398                 (sender_status == SENDER_ON)? "on" : "off",
 399                 stringify_port(conf.udp_default_port_arg, "udp"),
 400                 tgts? tgts : "(none)"
 401         );
 402         free(tgts);
 403         return ret;
 404 }
 405
 406 static void udp_init_target_list(void)
 407 {
 408         struct sender_command_data scd;
 409         int i;
 410
 411         INIT_LIST_HEAD(&targets);
 412         for (i = 0; i < conf.udp_target_given; i++) {
 413                 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
 414                         PARA_CRIT_LOG("not adding requested target '%s'\n",
 415                                         conf.udp_target_arg[i]);
 416                 else
 417                         udp_com_add(&scd);
 418         }
 419 }
 420
 421 static char *udp_help(void)
 422 {
 423         return make_message(
 424                 "usage: {on|off}\n"
 425                 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
 426                 "       - k is the number of data slices per FEC group\n"
 427                 "       - n is the total number of slices in a FEC group\n"
 428                 "       - packet_size reduces the slice size below path MTU\n\n"
 429                 "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
 430                 "          add 224.0.1.38:8080/14:16 (explicit FEC)\n"
 431                 "          add 10.10.1.42       (using default port)\n"
 432                 "          add [FF05::42]:1500  (IPv6 multicast)\n"
 433                 "          add [::1]            (IPv6 localhost/default port)\n"
 434                 "          delete myhost.net    (host with port wildcard)\n"
 435                 "          delete 10.1.2.3:456  (IPv4 with explicit port)\n"
 436                 "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
 437         );
 438 }
 439
 440 /**
 441  * The init function of para_server's udp sender.
 442  *
 443  * \param s Pointer to the udp sender struct.
 444  *
 445  * It initializes all function pointers of \a s and the list of udp targets.
 446  */
 447 void udp_send_init(struct sender *s)
 448 {
 449         INIT_LIST_HEAD(&targets);
 450         s->info = udp_info;
 451         s->help = udp_help;
 452         s->send = NULL;
 453         s->pre_select = NULL;
 454         s->post_select = NULL;
 455         s->shutdown_clients = udp_shutdown_targets;
 456         s->resolve_target = udp_resolve_target;
 457         s->client_cmds[SENDER_ON] = udp_com_on;
 458         s->client_cmds[SENDER_OFF] = udp_com_off;
 459         s->client_cmds[SENDER_DENY] = NULL;
 460         s->client_cmds[SENDER_ALLOW] = NULL;
 461         s->client_cmds[SENDER_ADD] = udp_com_add;
 462         s->client_cmds[SENDER_DELETE] = udp_com_delete;
 463         sender_status = SENDER_OFF;
 464         udp_init_target_list();
 465         if (!conf.udp_no_autostart_given)
 466                 sender_status = SENDER_ON;
 467         PARA_DEBUG_LOG("udp sender init complete\n");
 468 }