udp_send.c

   1 /*
   2  * Copyright (C) 2005-2009 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 <net/if.h>
  15 #include <osl.h>
  16
  17 #include "server.cmdline.h"
  18 #include "para.h"
  19 #include "error.h"
  20 #include "string.h"
  21 #include "afh.h"
  22 #include "afs.h"
  23 #include "server.h"
  24 #include "vss.h"
  25 #include "list.h"
  26 #include "send.h"
  27 #include "portable_io.h"
  28 #include "net.h"
  29 #include "fd.h"
  30 #include "sched.h"
  31 #include "close_on_fork.h"
  32 #include "chunk_queue.h"
  33
  34 /** Describes one entry in the list of targets for the udp sender. */
  35 struct udp_target {
  36         /** The position of this target in the list of targets. */
  37         struct list_head node;
  38         /** The hostname (DNS name or IPv4/v6 address string). */
  39         char host[MAX_HOSTLEN];
  40         /** The UDP port. */
  41         int port;
  42         /** The socket fd. */
  43         int fd;
  44         /** The list of queued chunks for this fd. */
  45         struct chunk_queue *cq;
  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 udp_target *ut)
  56 {
  57         if (ut->fd < 0)
  58                 return;
  59         close(ut->fd);
  60         del_close_on_fork_list(ut->fd);
  61         cq_destroy(ut->cq);
  62         ut->cq = NULL;
  63         ut->fd = -1;
  64 }
  65
  66 static void udp_delete_target(struct udp_target *ut, const char *msg)
  67 {
  68         PARA_NOTICE_LOG("deleting %s#%d (%s) from list\n", ut->host,
  69                 ut->port, msg);
  70         udp_close_target(ut);
  71         vss_del_fec_client(ut->fc);
  72         list_del(&ut->node);
  73         free(ut);
  74 }
  75
  76 /**
  77  * Perform AF-independent multicast sender setup.
  78  *
  79  * \param fd    The connected socket descriptor.
  80  * \param ttl   UDPv4 multicast TTL or UDPv6 multicast number of hops.
  81  *              Use -1 to mean default, 0..255 otherwise.
  82  * \param iface The outgoing multicast interface, or NULL for the default.
  83  *
  84  * \return Zero if okay, negative on error.
  85  */
  86 static int mcast_sender_setup(struct udp_target *ut, int ttl, char *iface)
  87 {
  88         struct sockaddr_storage ss;
  89         socklen_t sslen = sizeof(ss);
  90
  91         const int on = 1;
  92         int id = iface == NULL ? 0 : if_nametoindex(iface);
  93
  94         if (getpeername(ut->fd, (struct sockaddr *)&ss, &sslen) < 0)
  95                 goto err;
  96
  97         if (iface != NULL && id == 0)
  98                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
  99
 100         /* RFC 3493, 5.2: -1 means 'use kernel default' */
 101         if (ttl < 0 || ttl > 255)
 102                 ttl = -1;
 103
 104         switch (ss.ss_family) {
 105         case AF_INET:
 106                 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
 107                         return 0;
 108                 if (id != 0) {
 109 #ifdef HAVE_IP_MREQN
 110                         struct ip_mreqn mn;
 111
 112                         memset(&mn, 0, sizeof(mn));
 113                         mn.imr_ifindex = id;
 114                         if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
 115                                 goto err;
 116 #else
 117                         PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
 118 #endif
 119                 }
 120                 /*
 121                  * Enable receiving multicast messages generated on the local host
 122                  * At least on Linux, this is enabled by default.
 123                  */
 124                 if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 125                         break;
 126
 127                 /* Default: use local subnet (do not flood out into the WAN) */
 128                 if (ttl == -1)
 129                         ttl = 1;
 130                 if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 131                         break;
 132                 return 0;
 133         case AF_INET6:
 134                 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
 135                         return 0;
 136                 if (id != 0 &&
 137                     setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
 138                         break;
 139                 if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 140                         break;
 141                 if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 142                         break;
 143                 return 0;
 144         default:
 145                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 146                 return -E_ADDRESS_LOOKUP;
 147         }
 148 err:
 149         return -ERRNO_TO_PARA_ERROR(errno);
 150 }
 151
 152 /** The maximal size of the per-target chunk queue. */
 153 #define UDP_CQ_BYTES 40000
 154
 155 static int udp_init_session(struct udp_target *ut)
 156 {
 157         int ret;
 158         char *iface = NULL;
 159
 160         if (ut->fd >= 0) /* nothing to do */
 161                 return 0;
 162
 163         ret = makesock(AF_UNSPEC, IPPROTO_UDP, 0, ut->host, ut->port);
 164         if (ret < 0)
 165                 return ret;
 166         ut->fd = ret;
 167
 168         if (conf.udp_mcast_iface_given)
 169                 iface = conf.udp_mcast_iface_arg;
 170
 171         ret = mcast_sender_setup(ut, conf.udp_ttl_arg, iface);
 172         if (ret < 0) {
 173                 close(ut->fd);
 174                 return ret;
 175         }
 176
 177         ret = mark_fd_nonblocking(ut->fd);
 178         if (ret < 0) {
 179                 close(ut->fd);
 180                 return ret;
 181         }
 182         add_close_on_fork_list(ut->fd);
 183         ut->cq = cq_new(UDP_CQ_BYTES);
 184         PARA_NOTICE_LOG("sending to udp %s#%d\n", ut->host, ut->port);
 185         return 1;
 186 }
 187
 188 static void udp_shutdown_targets(void)
 189 {
 190         struct udp_target *ut, *tmp;
 191         const char *buf = NULL;
 192         size_t len = 0; /* STFU, gcc */
 193
 194         list_for_each_entry_safe(ut, tmp, &targets, node) {
 195                 if (ut->fd < 0)
 196                         continue;
 197                 if (!buf)
 198                         len = vss_get_fec_eof_packet(&buf);
 199                 write(ut->fd, buf, len);
 200                 udp_close_target(ut);
 201         }
 202 }
 203
 204 static int udp_com_on(__a_unused struct sender_command_data *scd)
 205 {
 206         sender_status = SENDER_ON;
 207         return 1;
 208 }
 209
 210 static int udp_com_off(__a_unused struct sender_command_data *scd)
 211 {
 212         udp_shutdown_targets();
 213         sender_status = SENDER_OFF;
 214         return 1;
 215 }
 216
 217 static int udp_com_delete(struct sender_command_data *scd)
 218 {
 219         struct udp_target *ut, *tmp;
 220
 221         list_for_each_entry_safe(ut, tmp, &targets, node) {
 222                 /* Unspecified port means wildcard port match */
 223                 if (scd->port > 0 && scd->port != ut->port)
 224                         continue;
 225                 if (strcmp(ut->host, scd->host))
 226                         continue;
 227                 udp_delete_target(ut, "com_delete");
 228         }
 229         return 1;
 230 }
 231
 232 static int udp_send_fec(char *buf, size_t len, void *private_data)
 233 {
 234         struct udp_target *ut = private_data;
 235         int ret = udp_init_session(ut);
 236
 237         if (ret < 0)
 238                 goto fail;
 239         ret = send_queued_chunks(ut->fd, ut->cq, 0);
 240         if (ret < 0)
 241                 goto fail;
 242         if (!len)
 243                 return 0;
 244         if (!ret) { /* still data left in the queue */
 245                 ret = cq_enqueue(ut->cq, buf, len);
 246                 if (ret < 0)
 247                         goto fail;
 248         }
 249         ret = write_nonblock(ut->fd, buf, len, 0);
 250         if (ret < 0)
 251                 goto fail;
 252         if (ret != len) {
 253                 ret = cq_enqueue(ut->cq, buf + ret, len - ret);
 254                 if (ret < 0)
 255                         goto fail;
 256         }
 257         return 1;
 258 fail:
 259         udp_delete_target(ut, para_strerror(-ret));
 260         return ret;
 261 }
 262
 263 static void udp_add_target(struct sender_command_data *scd)
 264 {
 265         struct udp_target *ut = para_calloc(sizeof(struct udp_target));
 266
 267         strncpy(ut->host, scd->host, sizeof(ut->host));
 268         ut->port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
 269         ut->fd = -1; /* not yet connected */
 270         PARA_INFO_LOG("adding to target list (%s#%d)\n", ut->host, ut->port);
 271         para_list_add(&ut->node, &targets);
 272         ut->fcp.slices_per_group = scd->slices_per_group;
 273         ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 274         ut->fcp.max_slice_bytes = scd->max_slice_bytes;
 275         ut->fcp.send = udp_send_fec;
 276         ut->fcp.private_data = ut;
 277         vss_add_fec_client(&ut->fcp, &ut->fc);
 278 }
 279
 280 static int udp_com_add(struct sender_command_data *scd)
 281 {
 282         udp_add_target(scd);
 283         return 1;
 284 }
 285
 286 static char *udp_info(void)
 287 {
 288         struct udp_target *ut;
 289         char *ret, *tgts = NULL;
 290
 291         list_for_each_entry(ut, &targets, node) {
 292                 bool is_v6 = strchr(ut->host, ':') != NULL;
 293                 char *tmp = make_message("%s%s%s%s:%d/%u:%u:%u ", tgts ? : "",
 294                         is_v6 ? "[" : "", ut->host,
 295                         is_v6 ? "]" : "", ut->port,
 296                         ut->fcp.max_slice_bytes,
 297                         ut->fcp.data_slices_per_group,
 298                         ut->fcp.slices_per_group
 299                 );
 300                 free(tgts);
 301                 tgts = tmp;
 302         }
 303         ret = make_message(
 304                 "udp sender:\n"
 305                 "\tstatus: %s\n"
 306                 "\tport: udp %d\n"
 307                 "\ttargets: %s\n",
 308                 (sender_status == SENDER_ON)? "on" : "off",
 309                 conf.udp_default_port_arg,
 310                 tgts? tgts : "(none)"
 311         );
 312         free(tgts);
 313         return ret;
 314 }
 315
 316 static void udp_init_target_list(void)
 317 {
 318         struct sender_command_data scd;
 319         int i;
 320
 321         INIT_LIST_HEAD(&targets);
 322         for (i = 0; i < conf.udp_target_given; i++) {
 323                 if (parse_fec_url(conf.udp_target_arg[i], &scd) < 0) {
 324                         PARA_CRIT_LOG("syntax error for udp target option "
 325                                 "#%d, ignoring\n", i);
 326                         continue;
 327                 }
 328                 udp_add_target(&scd);
 329         }
 330 }
 331
 332 static char *udp_help(void)
 333 {
 334         return make_message(
 335                 "usage: {on|off}\n"
 336                 "usage: {add|delete} host[:port][/packet_size:k:n]\n"
 337                 "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
 338                 "          add 224.0.1.38:1500/1400:14:16\n"
 339                 "              (likewise, using 1400 byte packets, with 14\n"
 340                 "               data slices per 16 slice FEC group)\n"
 341                 "          add 10.10.1.42       (using default port)\n"
 342                 "          add [FF05::42]:1500  (IPv6 multicast)\n"
 343                 "          add [::1]            (IPv6 localhost/default port)\n"
 344                 "          delete myhost.net    (host with port wildcard)\n"
 345                 "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
 346         );
 347 }
 348
 349 /**
 350  * The init function of para_server's udp sender.
 351  *
 352  * \param s Pointer to the udp sender struct.
 353  *
 354  * It initializes all function pointers of \a s and the list of udp targets.
 355  */
 356 void udp_send_init(struct sender *s)
 357 {
 358         INIT_LIST_HEAD(&targets);
 359         s->info = udp_info;
 360         s->help = udp_help;
 361         s->send = NULL;
 362         s->pre_select = NULL;
 363         s->post_select = NULL;
 364         s->shutdown_clients = udp_shutdown_targets;
 365         s->client_cmds[SENDER_ON] = udp_com_on;
 366         s->client_cmds[SENDER_OFF] = udp_com_off;
 367         s->client_cmds[SENDER_DENY] = NULL;
 368         s->client_cmds[SENDER_ALLOW] = NULL;
 369         s->client_cmds[SENDER_ADD] = udp_com_add;
 370         s->client_cmds[SENDER_DELETE] = udp_com_delete;
 371         sender_status = SENDER_OFF;
 372         udp_init_target_list();
 373         if (!conf.udp_no_autostart_given)
 374                 sender_status = SENDER_ON;
 375         PARA_DEBUG_LOG("udp sender init complete\n");
 376 }