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