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