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 udp_target *ut, const char *msg)
  67 {
  68         PARA_NOTICE_LOG("deleting %s (%s) from list\n", ut->sc->name, msg);
  69         udp_close_target(ut->sc);
  70         vss_del_fec_client(ut->fc);
  71         list_del(&ut->sc->node);
  72         free(ut->sc->name);
  73         free(ut->sc);
  74         free(ut);
  75 }
  76
  77 /**
  78  * Perform AF-independent multicast sender setup.
  79  *
  80  * \param sc    The connected sender client.
  81  *
  82  * \return Zero if okay, negative on error.
  83  */
  84 static int mcast_sender_setup(struct sender_client *sc)
  85 {
  86         struct sockaddr_storage ss;
  87         socklen_t sslen = sizeof(ss);
  88         int ttl = conf.udp_ttl_arg, id = 0;
  89         const int on = 1;
  90
  91         if (conf.udp_mcast_iface_given) {
  92                 char *iface = conf.udp_mcast_iface_arg;
  93
  94                 id = if_nametoindex(iface);
  95                 if (id == 0)
  96                         PARA_WARNING_LOG("could not resolve interface '%s', "
  97                                         "using default", iface);
  98         }
  99
 100         if (getpeername(sc->fd, (struct sockaddr *)&ss, &sslen) < 0)
 101                 goto err;
 102
 103         /* RFC 3493, 5.2: -1 means 'use kernel default' */
 104         if (ttl < 0 || ttl > 255)
 105                 ttl = -1;
 106
 107         switch (ss.ss_family) {
 108         case AF_INET:
 109                 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
 110                         return 0;
 111                 if (id != 0) {
 112 #ifdef HAVE_IP_MREQN
 113                         struct ip_mreqn mn;
 114
 115                         memset(&mn, 0, sizeof(mn));
 116                         mn.imr_ifindex = id;
 117                         if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
 118                                 goto err;
 119 #else
 120                         PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
 121 #endif
 122                 }
 123                 /*
 124                  * Enable receiving multicast messages generated on the local host
 125                  * At least on Linux, this is enabled by default.
 126                  */
 127                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 128                         break;
 129
 130                 /* Default: use local subnet (do not flood out into the WAN) */
 131                 if (ttl == -1)
 132                         ttl = 1;
 133                 if (setsockopt(sc->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 134                         break;
 135                 return 0;
 136         case AF_INET6:
 137                 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
 138                         return 0;
 139                 if (id != 0 &&
 140                     setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
 141                         break;
 142                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 143                         break;
 144                 if (setsockopt(sc->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 145                         break;
 146                 return 0;
 147         default:
 148                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 149                 return -E_ADDRESS_LOOKUP;
 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 int udp_com_delete(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                 struct udp_target *ut = sc->private_data;
 224                 parse_url(sc->name, host, sizeof(host), &port);
 225
 226                 /* Unspecified port means wildcard port match */
 227                 if (scd->port > 0 && scd->port != port)
 228                         continue;
 229                 if (strcmp(host, scd->host))
 230                         continue;
 231                 udp_delete_target(ut, "com_delete");
 232         }
 233         return 1;
 234 }
 235
 236 /** Initialize UDP session and set maximum payload size. */
 237 static int udp_init_fec(struct sender_client *sc)
 238 {
 239         int mps;
 240
 241         udp_init_session(sc);
 242         mps = generic_max_transport_msg_size(sc->fd) - sizeof(struct udphdr);
 243         PARA_INFO_LOG("current MPS = %d bytes\n", mps);
 244         return mps;
 245 }
 246
 247 /** Check and clear socket error if any. */
 248 static int udp_check_socket_state(struct udp_target *ut)
 249 {
 250         int ret;
 251         socklen_t errlen = sizeof(ret);
 252
 253         if (getsockopt(ut->sc->fd, SOL_SOCKET, SO_ERROR, &ret, &errlen) < 0) {
 254                 PARA_ERROR_LOG("SO_ERROR failed: %s\n", strerror(ret));
 255                 return 0;
 256         } else if (ret == 0) {
 257                 return 0;
 258         } else if (ret == ECONNREFUSED) {
 259                 time_t dist = now->tv_sec - ut->last_unreachable;
 260
 261                 if (dist <= UDP_MAX_UNREACHABLE_TIME) {
 262                         return 0;
 263                 } else if (dist > 2 * UDP_MAX_UNREACHABLE_TIME) {
 264                         ut->last_unreachable = now->tv_sec;
 265                         return 0;
 266                 } else {
 267                         /*
 268                          * unreachable_time < dist <= 2 * unreachable_time
 269                          * No errors are allowed during this time window.
 270                          */
 271                         PARA_NOTICE_LOG("Evicting %s after %d seconds "
 272                                         "of connection errors.\n",
 273                                         ut->sc->name, (int)dist);
 274                 }
 275         }
 276         return -ERRNO_TO_PARA_ERROR(ret);
 277 }
 278
 279 static int udp_send_fec(struct sender_client *sc, char *buf, size_t len)
 280 {
 281         struct udp_target *ut = sc->private_data;
 282         int ret;
 283
 284         if (sender_status == SENDER_OFF)
 285                 return 0;
 286         if (len == 0 && !cq_peek(ut->sc->cq))
 287                 return 0;
 288         ret = udp_check_socket_state(ut);
 289         if (ret < 0)
 290                 goto fail;
 291         ret = send_queued_chunks(sc->fd, sc->cq);
 292         if (ret < 0)
 293                 goto fail;
 294         if (!ret) { /* still data left in the queue */
 295                 ret = cq_force_enqueue(sc->cq, buf, len);
 296                 assert(ret >= 0);
 297                 return 0;
 298         }
 299         ret = write_nonblock(sc->fd, buf, len);
 300         if (ret == -ERRNO_TO_PARA_ERROR(ECONNREFUSED)) {
 301                 /*
 302                  * Happens if meanwhile an ICMP Destination / Port Unreachable
 303                  * has arrived. Ignore, persistent errors will be caught above.
 304                  */
 305                 ret = 0;
 306         }
 307         if (ret < 0)
 308                 goto fail;
 309         if (ret != len) {
 310                 ret = cq_force_enqueue(sc->cq, buf + ret, len - ret);
 311                 assert(ret >= 0);
 312         }
 313         return 1;
 314 fail:
 315         udp_delete_target(ut, para_strerror(-ret));
 316         return ret;
 317 }
 318
 319 static void udp_add_target(struct sender_command_data *scd)
 320 {
 321         int ret;
 322         struct udp_target *ut = para_calloc(sizeof(*ut));
 323
 324         ut->fcp.slices_per_group      = scd->slices_per_group;
 325         ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 326         ut->fcp.max_slice_bytes       = scd->max_slice_bytes;
 327         ut->fcp.init_fec              = udp_init_fec;
 328         ut->fcp.send_fec              = udp_send_fec;
 329
 330         ut->sc = para_calloc(sizeof(*ut->sc));
 331         ut->sc->private_data = ut;
 332         ut->sc->fd = -1;
 333         ret = para_connect_simple(IPPROTO_UDP, scd->host, scd->port);
 334         if (ret < 0)
 335                 goto err;
 336         ut->sc->fd = ret;
 337
 338         ret = mcast_sender_setup(ut->sc);
 339         if (ret < 0)
 340                 goto err;
 341         ret = mark_fd_nonblocking(ut->sc->fd);
 342         if (ret < 0)
 343                 goto err;
 344         ut->sc->name = para_strdup(remote_name(ut->sc->fd));
 345         PARA_INFO_LOG("adding to target list (%s)\n", ut->sc->name);
 346         ut->fc = vss_add_fec_client(ut->sc, &ut->fcp);
 347         para_list_add(&ut->sc->node, &targets);
 348         return;
 349 err:
 350         if (ut->sc->fd >= 0)
 351                 close(ut->sc->fd);
 352         PARA_NOTICE_LOG("failed to set up %s:%d (%s)- not adding it\n",
 353                         scd->host, scd->port, para_strerror(-ret));
 354         free(ut->sc);
 355         free(ut);
 356 }
 357
 358 static int udp_com_add(struct sender_command_data *scd)
 359 {
 360         udp_add_target(scd);
 361         return 1;
 362 }
 363
 364 static char *udp_info(void)
 365 {
 366         struct sender_client *sc;
 367         char *ret, *tgts = NULL;
 368
 369         list_for_each_entry(sc, &targets, node) {
 370                 struct udp_target *ut = sc->private_data;
 371                 char *tmp = make_message("%s%s/%u:%u:%u ", tgts ? : "",
 372                         ut->sc->name,
 373                         ut->fcp.max_slice_bytes,
 374                         ut->fcp.data_slices_per_group,
 375                         ut->fcp.slices_per_group
 376                 );
 377                 free(tgts);
 378                 tgts = tmp;
 379         }
 380         ret = make_message(
 381                 "udp sender:\n"
 382                 "\tstatus: %s\n"
 383                 "\tport: %s\n"
 384                 "\ttargets: %s\n",
 385                 (sender_status == SENDER_ON)? "on" : "off",
 386                 stringify_port(conf.udp_default_port_arg, "udp"),
 387                 tgts? tgts : "(none)"
 388         );
 389         free(tgts);
 390         return ret;
 391 }
 392
 393 static void udp_init_target_list(void)
 394 {
 395         struct sender_command_data scd;
 396         int i;
 397
 398         INIT_LIST_HEAD(&targets);
 399         for (i = 0; i < conf.udp_target_given; i++) {
 400                 if (udp_resolve_target(conf.udp_target_arg[i], &scd) < 0)
 401                         PARA_CRIT_LOG("not adding requested target '%s'\n",
 402                                         conf.udp_target_arg[i]);
 403                 else
 404                         udp_add_target(&scd);
 405         }
 406 }
 407
 408 static char *udp_help(void)
 409 {
 410         return make_message(
 411                 "usage: {on|off}\n"
 412                 "usage: {add|delete} host[:port][/packet_size:k:n]\n"
 413                 "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
 414                 "          add 224.0.1.38:1500/1400:14:16\n"
 415                 "              (likewise, using 1400 byte packets, with 14\n"
 416                 "               data slices per 16 slice FEC group)\n"
 417                 "          add 10.10.1.42       (using default port)\n"
 418                 "          add [FF05::42]:1500  (IPv6 multicast)\n"
 419                 "          add [::1]            (IPv6 localhost/default port)\n"
 420                 "          delete myhost.net    (host with port wildcard)\n"
 421                 "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
 422         );
 423 }
 424
 425 /**
 426  * The init function of para_server's udp sender.
 427  *
 428  * \param s Pointer to the udp sender struct.
 429  *
 430  * It initializes all function pointers of \a s and the list of udp targets.
 431  */
 432 void udp_send_init(struct sender *s)
 433 {
 434         INIT_LIST_HEAD(&targets);
 435         s->info = udp_info;
 436         s->help = udp_help;
 437         s->send = NULL;
 438         s->pre_select = NULL;
 439         s->post_select = NULL;
 440         s->shutdown_clients = udp_shutdown_targets;
 441         s->resolve_target = udp_resolve_target;
 442         s->client_cmds[SENDER_ON] = udp_com_on;
 443         s->client_cmds[SENDER_OFF] = udp_com_off;
 444         s->client_cmds[SENDER_DENY] = NULL;
 445         s->client_cmds[SENDER_ALLOW] = NULL;
 446         s->client_cmds[SENDER_ADD] = udp_com_add;
 447         s->client_cmds[SENDER_DELETE] = udp_com_delete;
 448         sender_status = SENDER_OFF;
 449         udp_init_target_list();
 450         if (!conf.udp_no_autostart_given)
 451                 sender_status = SENDER_ON;
 452         PARA_DEBUG_LOG("udp sender init complete\n");
 453 }