udp_send.c

   1 /*
   2  * Copyright (C) 2005-2014 Andre Noll <maan@tuebingen.mpg.de>
   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 #include <netinet/in.h>
  10 #include <sys/socket.h>
  11 #include <regex.h>
  12 #include <sys/types.h>
  13 #include <sys/socket.h>
  14 #include <netinet/udp.h>
  15 #include <net/if.h>
  16 #include <arpa/inet.h>
  17 #include <sys/un.h>
  18 #include <osl.h>
  19 #include <netdb.h>
  20
  21 #include "server.cmdline.h"
  22 #include "para.h"
  23 #include "error.h"
  24 #include "string.h"
  25 #include "afh.h"
  26 #include "afs.h"
  27 #include "server.h"
  28 #include "list.h"
  29 #include "send.h"
  30 #include "sched.h"
  31 #include "vss.h"
  32 #include "portable_io.h"
  33 #include "net.h"
  34 #include "fd.h"
  35 #include "close_on_fork.h"
  36
  37 /**
  38  * Time window during which ICMP Destination/Port Unreachable messages are
  39  * ignored, covering transient receiver problems such as restarting the
  40  * client, rebooting, reconfiguration, or handover.
  41  */
  42 #define UDP_MAX_UNREACHABLE_TIME 30
  43
  44 /** Describes one entry in the list of targets for the udp sender. */
  45 struct udp_target {
  46         /** Track time (seconds) of last ICMP Port Unreachable error */
  47         time_t last_unreachable;
  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         const char *buf;
  60         size_t len = vss_get_fec_eof_packet(&buf);
  61
  62         /*
  63          * Ignore the return value of wirte() since we are closing the target
  64          * anyway. The sole purpose of the "do_nothing" statement is to silence
  65          * gcc.
  66          */
  67         if (write(sc->fd, buf, len))
  68                 do_nothing;
  69 }
  70
  71 static void udp_delete_target(struct sender_client *sc, const char *msg)
  72 {
  73         struct udp_target *ut = sc->private_data;
  74
  75         PARA_NOTICE_LOG("deleting %s (%s) from list\n", sc->name, msg);
  76         udp_close_target(sc);
  77         close(sc->fd);
  78         del_close_on_fork_list(sc->fd);
  79         vss_del_fec_client(ut->fc);
  80         list_del(&sc->node);
  81         free(sc->name);
  82         free(sc);
  83         free(ut);
  84 }
  85
  86 /**
  87  * Perform AF-independent multicast sender setup.
  88  *
  89  * \param sc    The connected sender client.
  90  *
  91  * \return Zero if okay, negative on error.
  92  */
  93 static int mcast_sender_setup(struct sender_client *sc)
  94 {
  95         struct sockaddr_storage ss;
  96         socklen_t sslen = sizeof(ss);
  97         int ttl = conf.udp_ttl_arg, id = 0;
  98         const int on = 1;
  99
 100         if (conf.udp_mcast_iface_given) {
 101                 char *iface = conf.udp_mcast_iface_arg;
 102
 103                 id = if_nametoindex(iface);
 104                 if (id == 0)
 105                         PARA_WARNING_LOG("could not resolve interface '%s', "
 106                                         "using default", iface);
 107         }
 108
 109         if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
 110                 goto err;
 111         assert(ss.ss_family == AF_INET || ss.ss_family == AF_INET6);
 112
 113         /* RFC 3493, 5.2: -1 means 'use kernel default' */
 114         if (ttl < 0 || ttl > 255)
 115                 ttl = -1;
 116
 117         switch (ss.ss_family) {
 118         case AF_INET:
 119                 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
 120                         return 0;
 121                 if (id != 0) {
 122 #ifdef HAVE_IP_MREQN
 123                         struct ip_mreqn mn;
 124
 125                         memset(&mn, 0, sizeof(mn));
 126                         mn.imr_ifindex = id;
 127                         if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
 128                                 goto err;
 129 #else
 130                         PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
 131 #endif
 132                 }
 133                 /*
 134                  * Enable receiving multicast messages generated on the local host
 135                  * At least on Linux, this is enabled by default.
 136                  */
 137                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 138                         break;
 139
 140                 /* Default: use local subnet (do not flood out into the WAN) */
 141                 if (ttl == -1)
 142                         ttl = 1;
 143                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 144                         break;
 145                 return 0;
 146         case AF_INET6:
 147                 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
 148                         return 0;
 149                 if (id != 0 &&
 150                     setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
 151                         break;
 152                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 153                         break;
 154                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 155                         break;
 156                 return 0;
 157         }
 158 err:
 159         return -ERRNO_TO_PARA_ERROR(errno);
 160 }
 161
 162 static void udp_init_session(struct sender_client *sc)
 163 {
 164         PARA_NOTICE_LOG("sending to udp %s\n", sc->name);
 165 }
 166
 167 static void udp_shutdown_targets(void)
 168 {
 169         struct sender_client *sc, *tmp;
 170         list_for_each_entry_safe(sc, tmp, &targets, node)
 171                 udp_close_target(sc);
 172 }
 173
 174 static int udp_resolve_target(const char *url, struct sender_command_data *scd)
 175 {
 176         const char *result;
 177         int ret, port;
 178
 179         ret = parse_fec_url(url, scd);
 180         if (ret)
 181                 return ret;
 182         port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
 183
 184         ret = para_connect_simple(IPPROTO_UDP, scd->host, port);
 185         if (ret < 0)
 186                 return ret;
 187
 188         result = remote_name(ret);
 189         close(ret);
 190
 191         if (!parse_url(result, scd->host, sizeof(scd->host), &scd->port))
 192                 return -E_ADDRESS_LOOKUP;
 193         return 1;
 194 }
 195
 196 static int udp_com_on(__a_unused struct sender_command_data *scd)
 197 {
 198         sender_status = SENDER_ON;
 199         return 1;
 200 }
 201
 202 static int udp_com_off(__a_unused struct sender_command_data *scd)
 203 {
 204         udp_shutdown_targets();
 205         sender_status = SENDER_OFF;
 206         return 1;
 207 }
 208
 209 static struct sender_client *udp_lookup_target(struct sender_command_data *scd)
 210 {
 211         struct sender_client *sc, *tmp;
 212         char host[MAX_HOSTLEN];
 213         int32_t port;
 214
 215         list_for_each_entry_safe(sc, tmp, &targets, node) {
 216                 parse_url(sc->name, host, sizeof(host), &port);
 217
 218                 /* Unspecified port means wildcard port match */
 219                 if (scd->port > 0 && scd->port != port)
 220                         continue;
 221                 if (strcmp(host, scd->host))
 222                         continue;
 223                 return sc;
 224         }
 225         return NULL;
 226 }
 227
 228 static int udp_com_delete(struct sender_command_data *scd)
 229 {
 230         struct sender_client *sc = udp_lookup_target(scd);
 231
 232         if (sc) {
 233                 udp_delete_target(sc, "com_delete");
 234                 return 1;
 235         }
 236         PARA_NOTICE_LOG("not deleting non-existing target '%s'\n", scd->host);
 237         return -E_TARGET_NOT_FOUND;
 238 }
 239
 240 /** Initialize UDP session and set maximum payload size. */
 241 static int udp_init_fec(struct sender_client *sc)
 242 {
 243         int mps;
 244
 245         udp_init_session(sc);
 246         mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
 247         PARA_INFO_LOG("current MPS = %d bytes\n", mps);
 248         return mps;
 249 }
 250
 251 /** Check and clear socket error if any. */
 252 static int udp_check_socket_state(struct sender_client *sc)
 253 {
 254         struct udp_target *ut = sc->private_data;
 255         int ret;
 256         socklen_t errlen = sizeof(ret);
 257
 258         if (getsockopt(sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
 259                 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
 260                 return 0;
 261         } else if (ret == 0) {
 262                 return 0;
 263         } else if (ret == ECONNREFUSED) {
 264                 time_t dist = now->tv_sec - ut->last_unreachable;
 265
 266                 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
 267                         return 0;
 268                 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
 269                         ut->last_unreachable = now->tv_sec;
 270                         return 0;
 271                 } else {
 272                         /*
 273                          * unreachable_time < dist <= 2 * unreachable_time
 274                          * No errors are allowed during this time window.
 275                          */
 276                         PARA_NOTICE_LOG("Evicting %s after %d seconds "
 277                                         "of connection errors.\n",
 278                                         sc->name, (int)dist);
 279                 }
 280         }
 281         return -ERRNO_TO_PARA_ERROR(ret);
 282 }
 283
 284 static void udp_send_fec(struct sender_client *sc, char *buf, size_t len)
 285 {
 286         int ret;
 287
 288         if (sender_status == SENDER_OFF)
 289                 return;
 290         if (len == 0)
 291                 return;
 292         ret = udp_check_socket_state(sc);
 293         if (ret < 0)
 294                 goto fail;
 295         ret = xwrite(sc->fd, buf, len);
 296         if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
 297                 /*
 298                  * Happens if meanwhile an ICMP Destination / Port Unreachable
 299                  * has arrived. Ignore, persistent errors will be caught above.
 300                  */
 301                 ret = 0;
 302         }
 303         if (ret < 0)
 304                 goto fail;
 305         return;
 306 fail:
 307         udp_delete_target(sc, para_strerror(-ret));
 308 }
 309
 310 static int udp_com_add(struct sender_command_data *scd)
 311 {
 312         int ret;
 313         struct udp_target *ut;
 314         struct sender_client *sc = udp_lookup_target(scd);
 315
 316         if (sc) {
 317                 PARA_NOTICE_LOG("target %s already exists - not adding it\n",
 318                                 sc->name);
 319                 return -E_TARGET_EXISTS;
 320         }
 321         ut = para_calloc(sizeof(*ut));
 322         sc = para_calloc(sizeof(*sc));
 323         ut->fcp.slices_per_group      = scd->slices_per_group;
 324         ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 325         ut->fcp.init_fec              = udp_init_fec;
 326         ut->fcp.send_fec              = udp_send_fec;
 327         ut->fcp.need_periodic_header  = true;
 328
 329         sc->private_data = ut;
 330         sc->fd = -1;
 331         ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
 332         if (ret < 0)
 333                 goto err;
 334         sc->fd = ret;
 335
 336         ret = mcast_sender_setup(sc);
 337         if (ret < 0)
 338                 goto err;
 339         ret = mark_fd_nonblocking(sc->fd);
 340         if (ret < 0)
 341                 goto err;
 342         sc->name = para_strdup(remote_name(sc->fd));
 343         PARA_INFO_LOG("adding to target list (%s)\n", sc->name);
 344         ut->fc = vss_add_fec_client(sc, &ut->fcp);
 345         para_list_add(&sc->node, &targets);
 346         add_close_on_fork_list(sc->fd);
 347         return 1;
 348 err:
 349         if (sc->fd >= 0)
 350                 close(sc->fd);
 351         PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
 352                         scd->host, scd->port, para_strerror(-ret));
 353         free(sc);
 354         free(ut);
 355         return ret;
 356 }
 357
 358 static char *udp_info(void)
 359 {
 360         struct sender_client *sc;
 361         char *ret, *tgts = NULL;
 362
 363         list_for_each_entry(sc, &targets, node) {
 364                 struct udp_target *ut = sc->private_data;
 365                 char *tmp = make_message("%s%s/%u:%u ",
 366                         tgts ? : "", sc->name,
 367                         ut->fcp.data_slices_per_group,
 368                         ut->fcp.slices_per_group
 369                 );
 370                 free(tgts);
 371                 tgts = tmp;
 372         }
 373         ret = make_message(
 374                 "udp sender:\n"
 375                 "\tstatus: %s\n"
 376                 "\tport: %s\n"
 377                 "\ttargets: %s\n",
 378                 (sender_status == SENDER_ON)? "on" : "off",
 379                 stringify_port(conf.udp_default_port_arg, "udp"),
 380                 tgts? tgts : "(none)"
 381         );
 382         free(tgts);
 383         return ret;
 384 }
 385
 386 static void udp_init_target_list(void)
 387 {
 388         struct sender_command_data scd;
 389         int i;
 390
 391         INIT_LIST_HEAD(&targets);
 392         for (i = 0; i < conf.udp_target_given; i++) {
 393                 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
 394                         PARA_CRIT_LOG("not adding requested target '%s'\n",
 395                                         conf.udp_target_arg[i]);
 396                 else
 397                         udp_com_add(&scd);
 398         }
 399 }
 400
 401 static char *udp_help(void)
 402 {
 403         return make_message(
 404                 "usage: {on|off}\n"
 405                 "usage: {add|delete} ip_address[:port][/[packet_size:]k:n]\n"
 406                 "       - k is the number of data slices per FEC group\n"
 407                 "       - n is the total number of slices in a FEC group\n"
 408                 "       - packet_size reduces the slice size below path MTU\n\n"
 409                 "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
 410                 "          add 224.0.1.38:8080/14:16 (explicit FEC)\n"
 411                 "          add 10.10.1.42       (using default port)\n"
 412                 "          add [FF05::42]:1500  (IPv6 multicast)\n"
 413                 "          add [::1]            (IPv6 localhost/default port)\n"
 414                 "          delete myhost.net    (host with port wildcard)\n"
 415                 "          delete 10.1.2.3:456  (IPv4 with explicit port)\n"
 416                 "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
 417         );
 418 }
 419
 420 /**
 421  * The init function of para_server's udp sender.
 422  *
 423  * \param s Pointer to the udp sender struct.
 424  *
 425  * It initializes all function pointers of \a s and the list of udp targets.
 426  */
 427 void udp_send_init(struct sender *s)
 428 {
 429         INIT_LIST_HEAD(&targets);
 430         s->info = udp_info;
 431         s->help = udp_help;
 432         s->send = NULL;
 433         s->pre_select = NULL;
 434         s->post_select = NULL;
 435         s->shutdown_clients = udp_shutdown_targets;
 436         s->resolve_target = udp_resolve_target;
 437         s->client_cmds[SENDER_ON] = udp_com_on;
 438         s->client_cmds[SENDER_OFF] = udp_com_off;
 439         s->client_cmds[SENDER_DENY] = NULL;
 440         s->client_cmds[SENDER_ALLOW] = NULL;
 441         s->client_cmds[SENDER_ADD] = udp_com_add;
 442         s->client_cmds[SENDER_DELETE] = udp_com_delete;
 443         sender_status = SENDER_OFF;
 444         udp_init_target_list();
 445         if (!conf.udp_no_autostart_given)
 446                 sender_status = SENDER_ON;
 447         PARA_DEBUG_LOG("udp sender init complete\n");
 448 }