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 <sys/time.h>
  11 #include <dirent.h>
  12 #include <net/if.h>
  13
  14 #include "server.cmdline.h"
  15 #include "para.h"
  16 #include "error.h"
  17 #include "string.h"
  18 #include "afh.h"
  19 #include "afs.h"
  20 #include "server.h"
  21 #include "vss.h"
  22 #include "list.h"
  23 #include "send.h"
  24 #include "portable_io.h"
  25 #include "net.h"
  26 #include "fd.h"
  27 #include "sched.h"
  28 #include "close_on_fork.h"
  29 #include "chunk_queue.h"
  30
  31 /** Describes one entry in the list of targets for the udp sender. */
  32 struct udp_target {
  33         /** The position of this target in the list of targets. */
  34         struct list_head node;
  35         /** The hostname (DNS name or IPv4/v6 address string). */
  36         char host[MAX_HOSTLEN];
  37         /** The UDP port. */
  38         int port;
  39         /** The socket fd. */
  40         int fd;
  41         /** The list of queued chunks for this fd. */
  42         struct chunk_queue *cq;
  43         /** The opaque structure returned by vss_add_fec_client(). */
  44         struct fec_client *fc;
  45         /** The FEC parameters for this target. */
  46         struct fec_client_parms fcp;
  47 };
  48
  49 static struct list_head targets;
  50 static int sender_status;
  51
  52 static void udp_close_target(struct udp_target *ut)
  53 {
  54         if (ut->fd < 0)
  55                 return;
  56         close(ut->fd);
  57         del_close_on_fork_list(ut->fd);
  58         cq_destroy(ut->cq);
  59         ut->cq = NULL;
  60         ut->fd = -1;
  61 }
  62
  63 static void udp_delete_target(struct udp_target *ut, const char *msg)
  64 {
  65         PARA_NOTICE_LOG("deleting %s#%d (%s) from list\n", ut->host,
  66                 ut->port, msg);
  67         udp_close_target(ut);
  68         vss_del_fec_client(ut->fc);
  69         list_del(&ut->node);
  70         free(ut);
  71 }
  72
  73 /**
  74  * Perform AF-independent multicast sender setup.
  75  *
  76  * \param fd    The connected socket descriptor.
  77  * \param ttl   UDPv4 multicast TTL or UDPv6 multicast number of hops.
  78  *              Use -1 to mean default, 0..255 otherwise.
  79  * \param iface The outgoing multicast interface, or NULL for the default.
  80  *
  81  * \return Zero if okay, negative on error.
  82  */
  83 static int mcast_sender_setup(struct udp_target *ut, int ttl, char *iface)
  84 {
  85         struct sockaddr_storage ss;
  86         socklen_t sslen = sizeof(ss);
  87
  88         const int on = 1;
  89         int id = iface == NULL ? 0 : if_nametoindex(iface);
  90
  91         if (getpeername(ut->fd, (struct sockaddr *)&ss, &sslen) < 0)
  92                 goto err;
  93
  94         if (iface != NULL && id == 0)
  95                 PARA_WARNING_LOG("could not resolve interface %s, using default", iface);
  96
  97         /* RFC 3493, 5.2: -1 means 'use kernel default' */
  98         if (ttl < 0 || ttl > 255)
  99                 ttl = -1;
 100
 101         switch (ss.ss_family) {
 102         case AF_INET:
 103                 if (!IN_MULTICAST(htonl(((struct sockaddr_in *)&ss)->sin_addr.s_addr)))
 104                         return 0;
 105                 if (id != 0) {
 106 #ifdef HAVE_IP_MREQN
 107                         struct ip_mreqn mn;
 108
 109                         memset(&mn, 0, sizeof(mn));
 110                         mn.imr_ifindex = id;
 111                         if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_IF, &mn, sizeof(mn)) < 0)
 112                                 goto err;
 113 #else
 114                         PARA_ERROR_LOG("No support for setting outgoing IPv4 mcast interface.");
 115 #endif
 116                 }
 117                 /*
 118                  * Enable receiving multicast messages generated on the local host
 119                  * At least on Linux, this is enabled by default.
 120                  */
 121                 if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 122                         break;
 123
 124                 /* Default: use local subnet (do not flood out into the WAN) */
 125                 if (ttl == -1)
 126                         ttl = 1;
 127                 if (setsockopt(ut->fd, IPPROTO_IP, IP_MULTICAST_TTL, &ttl, sizeof(ttl)) < 0)
 128                         break;
 129                 return 0;
 130         case AF_INET6:
 131                 if (!IN6_IS_ADDR_MULTICAST(&((struct sockaddr_in6 *)&ss)->sin6_addr))
 132                         return 0;
 133                 if (id != 0 &&
 134                     setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_IF, &id, sizeof(id)) < 0)
 135                         break;
 136                 if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_LOOP, &on, sizeof(on)) < 0)
 137                         break;
 138                 if (setsockopt(ut->fd, IPPROTO_IPV6, IPV6_MULTICAST_HOPS, &ttl, sizeof(ttl)) < 0)
 139                         break;
 140                 return 0;
 141         default:
 142                 PARA_ERROR_LOG("address family %d not supported", ss.ss_family);
 143                 return -E_ADDRESS_LOOKUP;
 144         }
 145 err:
 146         return -ERRNO_TO_PARA_ERROR(errno);
 147 }
 148
 149 /** The maximal size of the per-target chunk queue. */
 150 #define UDP_CQ_BYTES 40000
 151
 152 static int udp_init_session(struct udp_target *ut)
 153 {
 154         int ret;
 155         char *iface = NULL;
 156
 157         if (ut->fd >= 0) /* nothing to do */
 158                 return 0;
 159
 160         ret = makesock(AF_UNSPEC, IPPROTO_UDP, 0, ut->host, ut->port);
 161         if (ret < 0)
 162                 return ret;
 163         ut->fd = ret;
 164
 165         if (conf.udp_mcast_iface_given)
 166                 iface = conf.udp_mcast_iface_arg;
 167
 168         ret = mcast_sender_setup(ut, conf.udp_ttl_arg, iface);
 169         if (ret < 0) {
 170                 close(ut->fd);
 171                 return ret;
 172         }
 173
 174         ret = mark_fd_nonblocking(ut->fd);
 175         if (ret < 0) {
 176                 close(ut->fd);
 177                 return ret;
 178         }
 179         add_close_on_fork_list(ut->fd);
 180         ut->cq = cq_new(UDP_CQ_BYTES);
 181         PARA_NOTICE_LOG("sending to udp %s#%d using fec parms %d:%d:%d\n",
 182                 ut->host, ut->port , ut->fcp.max_slice_bytes,
 183                 ut->fcp.data_slices_per_group, ut->fcp.slices_per_group);
 184         return 1;
 185 }
 186
 187 static void udp_shutdown_targets(void)
 188 {
 189         struct udp_target *ut, *tmp;
 190         const char *buf = NULL;
 191         size_t len = 0; /* STFU, gcc */
 192
 193         list_for_each_entry_safe(ut, tmp, &targets, node) {
 194                 if (ut->fd < 0)
 195                         continue;
 196                 if (!buf)
 197                         len = vss_get_fec_eof_packet(&buf);
 198                 write(ut->fd, buf, len);
 199                 udp_close_target(ut);
 200         }
 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 udp_target *ut, *tmp;
 219
 220         list_for_each_entry_safe(ut, tmp, &targets, node) {
 221                 /* Unspecified port means wildcard port match */
 222                 if (scd->port > 0 && scd->port != ut->port)
 223                         continue;
 224                 if (strcmp(ut->host, scd->host))
 225                         continue;
 226                 udp_delete_target(ut, "com_delete");
 227         }
 228         return 1;
 229 }
 230
 231 static int udp_send_fec(char *buf, size_t len, void *private_data)
 232 {
 233         struct udp_target *ut = private_data;
 234         int ret = udp_init_session(ut);
 235
 236         if (ret < 0)
 237                 goto fail;
 238         ret = send_queued_chunks(ut->fd, ut->cq, 0);
 239         if (ret < 0)
 240                 goto fail;
 241         if (!len)
 242                 return 0;
 243         if (!ret) { /* still data left in the queue */
 244                 ret = cq_enqueue(ut->cq, buf, len);
 245                 if (ret < 0)
 246                         goto fail;
 247         }
 248         ret = write_nonblock(ut->fd, buf, len, 0);
 249         if (ret < 0)
 250                 goto fail;
 251         if (ret != len) {
 252                 ret = cq_enqueue(ut->cq, buf + ret, len - ret);
 253                 if (ret < 0)
 254                         goto fail;
 255         }
 256         return 1;
 257 fail:
 258         udp_delete_target(ut, para_strerror(-ret));
 259         return ret;
 260 }
 261
 262 static void udp_add_target(struct sender_command_data *scd)
 263 {
 264         struct udp_target *ut = para_calloc(sizeof(struct udp_target));
 265
 266         strncpy(ut->host, scd->host, sizeof(ut->host));
 267         ut->port = scd->port > 0 ? scd->port : conf.udp_default_port_arg;
 268         ut->fd = -1; /* not yet connected */
 269         PARA_INFO_LOG("adding to target list (%s#%d)\n", ut->host, ut->port);
 270         para_list_add(&ut->node, &targets);
 271         ut->fcp.slices_per_group = scd->slices_per_group;
 272         ut->fcp.data_slices_per_group = scd->data_slices_per_group;
 273         ut->fcp.max_slice_bytes = scd->max_slice_bytes;
 274         ut->fcp.send = udp_send_fec;
 275         ut->fcp.private_data = ut;
 276         vss_add_fec_client(&ut->fcp, &ut->fc);
 277 }
 278
 279 static int udp_com_add(struct sender_command_data *scd)
 280 {
 281         udp_add_target(scd);
 282         return 1;
 283 }
 284
 285 static char *udp_info(void)
 286 {
 287         struct udp_target *ut;
 288         char *ret, *tgts = NULL;
 289
 290         list_for_each_entry(ut, &targets, node) {
 291                 bool is_v6 = strchr(ut->host, ':') != NULL;
 292                 char *tmp = make_message("%s%s%s%s:%d/%u:%u:%u ", tgts ? : "",
 293                         is_v6 ? "[" : "", ut->host,
 294                         is_v6 ? "]" : "", ut->port,
 295                         ut->fcp.max_slice_bytes,
 296                         ut->fcp.data_slices_per_group,
 297                         ut->fcp.slices_per_group
 298                 );
 299                 free(tgts);
 300                 tgts = tmp;
 301         }
 302         ret = make_message(
 303                 "udp sender:\n"
 304                 "\tstatus: %s\n"
 305                 "\tport: udp %d\n"
 306                 "\ttargets: %s\n",
 307                 (sender_status == SENDER_ON)? "on" : "off",
 308                 conf.udp_default_port_arg,
 309                 tgts? tgts : "(none)"
 310         );
 311         free(tgts);
 312         return ret;
 313 }
 314
 315 static void udp_init_target_list(void)
 316 {
 317         struct sender_command_data scd;
 318         int i;
 319
 320         INIT_LIST_HEAD(&targets);
 321         for (i = 0; i < conf.udp_target_given; i++) {
 322                 if (parse_fec_url(conf.udp_target_arg[i], &scd) < 0) {
 323                         PARA_CRIT_LOG("syntax error for udp target option "
 324                                 "#%d, ignoring\n", i);
 325                         continue;
 326                 }
 327                 udp_add_target(&scd);
 328         }
 329 }
 330
 331 static char *udp_help(void)
 332 {
 333         return make_message(
 334                 "usage: {on|off}\n"
 335                 "usage: {add|delete} host[:port][/packet_size:k:n]\n"
 336                 "examples: add 224.0.1.38:1500  (IPv4 multicast)\n"
 337                 "          add 224.0.1.38:1500/1400:14:16\n"
 338                 "              (likewise, using 1400 byte packets, with 14\n"
 339                 "               data slices per 16 slice FEC group)\n"
 340                 "          add 10.10.1.42       (using default port)\n"
 341                 "          add [FF05::42]:1500  (IPv6 multicast)\n"
 342                 "          add [::1]            (IPv6 localhost/default port)\n"
 343                 "          delete myhost.net    (host with port wildcard)\n"
 344                 "          delete [badc0de::1]  (IPv6 with port wildcard)\n"
 345         );
 346 }
 347
 348 /**
 349  * The init function of para_server's udp sender.
 350  *
 351  * \param s Pointer to the http sender struct.
 352  *
 353  * It initializes all function pointers of \a s and the list of udp targets.
 354  */
 355 void udp_send_init(struct sender *s)
 356 {
 357         INIT_LIST_HEAD(&targets);
 358         s->info = udp_info;
 359         s->help = udp_help;
 360         s->send = NULL;
 361         s->pre_select = NULL;
 362         s->post_select = NULL;
 363         s->shutdown_clients = udp_shutdown_targets;
 364         s->client_cmds[SENDER_ON] = udp_com_on;
 365         s->client_cmds[SENDER_OFF] = udp_com_off;
 366         s->client_cmds[SENDER_DENY] = NULL;
 367         s->client_cmds[SENDER_ALLOW] = NULL;
 368         s->client_cmds[SENDER_ADD] = udp_com_add;
 369         s->client_cmds[SENDER_DELETE] = udp_com_delete;
 370         sender_status = SENDER_OFF;
 371         udp_init_target_list();
 372         if (!conf.udp_no_autostart_given)
 373                 sender_status = SENDER_ON;
 374         PARA_DEBUG_LOG("udp sender init complete\n");
 375 }