pimd/pim_zlookup.c

   1 /*
   2   PIM for Quagga
   3   Copyright (C) 2008  Everton da Silva Marques
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9
  10   This program is distributed in the hope that it will be useful, but
  11   WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13   General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; see the file COPYING; if not, write to the
  17   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18   MA 02110-1301 USA
  19
  20   $QuaggaId: $Format:%an, %ai, %h$ $
  21 */
  22
  23 #include <zebra.h>
  24 #include "zebra/rib.h"
  25
  26 #include "log.h"
  27 #include "prefix.h"
  28 #include "zclient.h"
  29 #include "stream.h"
  30 #include "network.h"
  31 #include "thread.h"
  32
  33 #include "pimd.h"
  34 #include "pim_pim.h"
  35 #include "pim_str.h"
  36 #include "pim_zlookup.h"
  37
  38 extern int zclient_debug;
  39
  40 static void zclient_lookup_sched(struct zclient *zlookup, int delay);
  41
  42 /* Connect to zebra for nexthop lookup. */
  43 static int zclient_lookup_connect(struct thread *t)
  44 {
  45   struct zclient *zlookup;
  46
  47   zlookup = THREAD_ARG(t);
  48   zlookup->t_connect = NULL;
  49
  50   if (zlookup->sock >= 0) {
  51     return 0;
  52   }
  53
  54   if (zclient_socket_connect(zlookup) < 0) {
  55     ++zlookup->fail;
  56     zlog_warn("%s: failure connecting zclient socket: failures=%d",
  57               __PRETTY_FUNCTION__, zlookup->fail);
  58   }
  59   else {
  60     zlookup->fail = 0; /* reset counter on connection */
  61   }
  62
  63   zassert(!zlookup->t_connect);
  64   if (zlookup->sock < 0) {
  65     /* Since last connect failed, retry within 10 secs */
  66     zclient_lookup_sched(zlookup, 10);
  67     return -1;
  68   }
  69
  70   return 0;
  71 }
  72
  73 /* Schedule connection with delay. */
  74 static void zclient_lookup_sched(struct zclient *zlookup, int delay)
  75 {
  76   zassert(!zlookup->t_connect);
  77
  78   THREAD_TIMER_ON(master, zlookup->t_connect,
  79                   zclient_lookup_connect,
  80                   zlookup, delay);
  81
  82   zlog_notice("%s: zclient lookup connection scheduled for %d seconds",
  83               __PRETTY_FUNCTION__, delay);
  84 }
  85
  86 /* Schedule connection for now. */
  87 static void zclient_lookup_sched_now(struct zclient *zlookup)
  88 {
  89   zassert(!zlookup->t_connect);
  90
  91   zlookup->t_connect = thread_add_event(master, zclient_lookup_connect,
  92                                         zlookup, 0);
  93
  94   zlog_notice("%s: zclient lookup immediate connection scheduled",
  95               __PRETTY_FUNCTION__);
  96 }
  97
  98 /* Schedule reconnection, if needed. */
  99 static void zclient_lookup_reconnect(struct zclient *zlookup)
 100 {
 101   if (zlookup->t_connect) {
 102     return;
 103   }
 104
 105   zclient_lookup_sched_now(zlookup);
 106 }
 107
 108 static void zclient_lookup_failed(struct zclient *zlookup)
 109 {
 110   if (zlookup->sock >= 0) {
 111     if (close(zlookup->sock)) {
 112       zlog_warn("%s: closing fd=%d: errno=%d %s", __func__, zlookup->sock,
 113                 errno, safe_strerror(errno));
 114     }
 115     zlookup->sock = -1;
 116   }
 117
 118   zclient_lookup_reconnect(zlookup);
 119 }
 120
 121 struct zclient *zclient_lookup_new()
 122 {
 123   struct zclient *zlookup;
 124
 125   zlookup = zclient_new (master);
 126   if (!zlookup) {
 127     zlog_err("%s: zclient_new() failure",
 128              __PRETTY_FUNCTION__);
 129     return 0;
 130   }
 131
 132   zlookup->sock = -1;
 133   zlookup->ibuf = stream_new(ZEBRA_MAX_PACKET_SIZ);
 134   zlookup->obuf = stream_new(ZEBRA_MAX_PACKET_SIZ);
 135   zlookup->t_connect = 0;
 136
 137   zclient_lookup_sched_now(zlookup);
 138
 139   zlog_notice("%s: zclient lookup socket initialized",
 140               __PRETTY_FUNCTION__);
 141
 142   return zlookup;
 143 }
 144
 145 static int zclient_read_nexthop(struct zclient *zlookup,
 146                                 struct pim_zlookup_nexthop nexthop_tab[],
 147                                 const int tab_size,
 148                                 struct in_addr addr)
 149 {
 150   int num_ifindex = 0;
 151   struct stream *s;
 152   const uint16_t MIN_LEN = 10; /* getipv4=4 getc=1 getl=4 getc=1 */
 153   uint16_t length;
 154   u_char marker;
 155   u_char version;
 156   vrf_id_t vrf_id;
 157   uint16_t command = 0;
 158   struct in_addr raddr;
 159   uint8_t distance;
 160   uint32_t metric;
 161   int nexthop_num;
 162   int i, err;
 163
 164   if (PIM_DEBUG_ZEBRA) {
 165     char addr_str[100];
 166     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 167     zlog_debug("%s: addr=%s",
 168                __PRETTY_FUNCTION__,
 169                addr_str);
 170   }
 171
 172   s = zlookup->ibuf;
 173
 174   while (command != ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB)
 175     {
 176       stream_reset(s);
 177       err = zclient_read_header (s, zlookup->sock, &length, &marker, &version,
 178                                  &vrf_id, &command);
 179       if (err < 0) {
 180         zlog_err("%s %s: zclient_read_header() failed",
 181                  __FILE__, __PRETTY_FUNCTION__);
 182         zclient_lookup_failed(zlookup);
 183         return -1;
 184       }
 185
 186       if (length < MIN_LEN) {
 187         zlog_err("%s %s: failure reading zclient lookup socket: len=%d < MIN_LEN=%d",
 188                  __FILE__, __PRETTY_FUNCTION__, length, MIN_LEN);
 189         zclient_lookup_failed(zlookup);
 190         return -2;
 191       }
 192
 193       if (version != ZSERV_VERSION || marker != ZEBRA_HEADER_MARKER) {
 194         zlog_err("%s: socket %d version mismatch, marker %d, version %d",
 195                  __func__, zlookup->sock, marker, version);
 196         zclient_lookup_failed(zlookup);
 197         return -4;
 198       }
 199     }
 200
 201   raddr.s_addr = stream_get_ipv4(s);
 202
 203   if (raddr.s_addr != addr.s_addr) {
 204     char addr_str[100];
 205     char raddr_str[100];
 206     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 207     pim_inet4_dump("<raddr?>", raddr, raddr_str, sizeof(raddr_str));
 208     zlog_warn("%s: address mismatch: addr=%s raddr=%s",
 209                __PRETTY_FUNCTION__,
 210                addr_str, raddr_str);
 211     /* warning only */
 212   }
 213
 214   distance = stream_getc(s);
 215   metric = stream_getl(s);
 216   nexthop_num = stream_getc(s);
 217
 218   if (nexthop_num < 1) {
 219     zlog_err("%s: socket %d bad nexthop_num=%d",
 220             __func__, zlookup->sock, nexthop_num);
 221     return -6;
 222   }
 223
 224   length -= MIN_LEN;
 225
 226   for (i = 0; i < nexthop_num; ++i) {
 227     enum nexthop_types_t nexthop_type;
 228
 229     if (length < 1) {
 230       zlog_err("%s: socket %d empty input expecting nexthop_type: len=%d",
 231                __func__, zlookup->sock, length);
 232       return -7;
 233     }
 234
 235     nexthop_type = stream_getc(s);
 236     --length;
 237
 238     switch (nexthop_type) {
 239     case ZEBRA_NEXTHOP_IFINDEX:
 240     case ZEBRA_NEXTHOP_IPV4_IFINDEX:
 241       if (num_ifindex >= tab_size) {
 242         char addr_str[100];
 243         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 244         zlog_warn("%s %s: found too many nexthop ifindexes (%d > %d) for address %s",
 245                  __FILE__, __PRETTY_FUNCTION__,
 246                  (num_ifindex + 1), tab_size, addr_str);
 247         return num_ifindex;
 248       }
 249       if (nexthop_type == ZEBRA_NEXTHOP_IPV4_IFINDEX) {
 250         if (length < 4) {
 251           zlog_err("%s: socket %d short input expecting nexthop IPv4-addr: len=%d",
 252                    __func__, zlookup->sock, length);
 253           return -8;
 254         }
 255         nexthop_tab[num_ifindex].nexthop_addr.s_addr = stream_get_ipv4(s);
 256         length -= 4;
 257       }
 258       else {
 259         nexthop_tab[num_ifindex].nexthop_addr.s_addr = PIM_NET_INADDR_ANY;
 260       }
 261       nexthop_tab[num_ifindex].ifindex           = stream_getl(s);
 262       nexthop_tab[num_ifindex].protocol_distance = distance;
 263       nexthop_tab[num_ifindex].route_metric      = metric;
 264       ++num_ifindex;
 265       break;
 266     case ZEBRA_NEXTHOP_IPV4:
 267       if (num_ifindex >= tab_size) {
 268         char addr_str[100];
 269         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 270         zlog_warn("%s %s: found too many nexthop ifindexes (%d > %d) for address %s",
 271                  __FILE__, __PRETTY_FUNCTION__,
 272                  (num_ifindex + 1), tab_size, addr_str);
 273         return num_ifindex;
 274       }
 275       nexthop_tab[num_ifindex].nexthop_addr.s_addr = stream_get_ipv4(s);
 276       length -= 4;
 277       nexthop_tab[num_ifindex].ifindex             = 0;
 278       nexthop_tab[num_ifindex].protocol_distance   = distance;
 279       nexthop_tab[num_ifindex].route_metric        = metric;
 280       if (PIM_DEBUG_ZEBRA) {
 281         char addr_str[100];
 282         char nexthop_str[100];
 283         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 284         pim_inet4_dump("<nexthop?>", nexthop_tab[num_ifindex].nexthop_addr, nexthop_str, sizeof(nexthop_str));
 285         zlog_debug("%s %s: zebra returned recursive nexthop %s for address %s",
 286                    __FILE__, __PRETTY_FUNCTION__,
 287                    nexthop_str, addr_str);
 288       }
 289       ++num_ifindex;
 290       break;
 291     default:
 292       /* do nothing */
 293       {
 294         char addr_str[100];
 295         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 296         zlog_warn("%s %s: found non-ifindex nexthop type=%d for address %s",
 297                  __FILE__, __PRETTY_FUNCTION__,
 298                   nexthop_type, addr_str);
 299       }
 300       break;
 301     }
 302   }
 303
 304   return num_ifindex;
 305 }
 306
 307 static int zclient_lookup_nexthop_once(struct zclient *zlookup,
 308                                        struct pim_zlookup_nexthop nexthop_tab[],
 309                                        const int tab_size,
 310                                        struct in_addr addr)
 311 {
 312   struct stream *s;
 313   int ret;
 314
 315   if (PIM_DEBUG_ZEBRA) {
 316     char addr_str[100];
 317     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 318     zlog_debug("%s: addr=%s",
 319                __PRETTY_FUNCTION__,
 320                addr_str);
 321   }
 322
 323   /* Check socket. */
 324   if (zlookup->sock < 0) {
 325     zlog_err("%s %s: zclient lookup socket is not connected",
 326              __FILE__, __PRETTY_FUNCTION__);
 327     zclient_lookup_failed(zlookup);
 328     return -1;
 329   }
 330
 331   s = zlookup->obuf;
 332   stream_reset(s);
 333   zclient_create_header(s, ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB, VRF_DEFAULT);
 334   stream_put_in_addr(s, &addr);
 335   stream_putw_at(s, 0, stream_get_endp(s));
 336
 337   ret = writen(zlookup->sock, s->data, stream_get_endp(s));
 338   if (ret < 0) {
 339     zlog_err("%s %s: writen() failure writing to zclient lookup socket",
 340              __FILE__, __PRETTY_FUNCTION__);
 341     zclient_lookup_failed(zlookup);
 342     return -2;
 343   }
 344   if (ret == 0) {
 345     zlog_err("%s %s: connection closed on zclient lookup socket",
 346              __FILE__, __PRETTY_FUNCTION__);
 347     zclient_lookup_failed(zlookup);
 348     return -3;
 349   }
 350
 351   return zclient_read_nexthop(zlookup, nexthop_tab,
 352                               tab_size, addr);
 353 }
 354
 355 int zclient_lookup_nexthop(struct zclient *zlookup,
 356                            struct pim_zlookup_nexthop nexthop_tab[],
 357                            const int tab_size,
 358                            struct in_addr addr,
 359                            int max_lookup)
 360 {
 361   int lookup;
 362   uint32_t route_metric = 0xFFFFFFFF;
 363   uint8_t  protocol_distance = 0xFF;
 364
 365   for (lookup = 0; lookup < max_lookup; ++lookup) {
 366     int num_ifindex;
 367     int first_ifindex;
 368     struct in_addr nexthop_addr;
 369
 370     num_ifindex = zclient_lookup_nexthop_once(qpim_zclient_lookup, nexthop_tab,
 371                                               PIM_NEXTHOP_IFINDEX_TAB_SIZE, addr);
 372     if (num_ifindex < 1) {
 373       if (PIM_DEBUG_ZEBRA) {
 374         char addr_str[100];
 375         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 376         zlog_debug("%s %s: lookup=%d/%d: could not find nexthop ifindex for address %s",
 377                    __FILE__, __PRETTY_FUNCTION__,
 378                    lookup, max_lookup, addr_str);
 379       }
 380       return -1;
 381     }
 382
 383     if (lookup < 1) {
 384       /* this is the non-recursive lookup - save original metric/distance */
 385       route_metric = nexthop_tab[0].route_metric;
 386       protocol_distance = nexthop_tab[0].protocol_distance;
 387     }
 388
 389     /*
 390       FIXME: Non-recursive nexthop ensured only for first ifindex.
 391       However, recursive route lookup should really be fixed in zebra daemon.
 392       See also TODO T24.
 393      */
 394     first_ifindex = nexthop_tab[0].ifindex;
 395     nexthop_addr = nexthop_tab[0].nexthop_addr;
 396     if (first_ifindex > 0) {
 397       /* found: first ifindex is non-recursive nexthop */
 398
 399       if (lookup > 0) {
 400         /* Report non-recursive success after first lookup */
 401         if (PIM_DEBUG_ZEBRA) {
 402           char addr_str[100];
 403           pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 404           zlog_debug("%s %s: lookup=%d/%d: found non-recursive ifindex=%d for address %s dist=%d met=%d",
 405                      __FILE__, __PRETTY_FUNCTION__,
 406                      lookup, max_lookup, first_ifindex, addr_str,
 407                      nexthop_tab[0].protocol_distance,
 408                      nexthop_tab[0].route_metric);
 409         }
 410
 411         /* use last address as nexthop address */
 412         nexthop_tab[0].nexthop_addr = addr;
 413
 414         /* report original route metric/distance */
 415         nexthop_tab[0].route_metric = route_metric;
 416         nexthop_tab[0].protocol_distance = protocol_distance;
 417       }
 418
 419       return num_ifindex;
 420     }
 421
 422     if (PIM_DEBUG_ZEBRA) {
 423       char addr_str[100];
 424       char nexthop_str[100];
 425       pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 426       pim_inet4_dump("<nexthop?>", nexthop_addr, nexthop_str, sizeof(nexthop_str));
 427       zlog_debug("%s %s: lookup=%d/%d: zebra returned recursive nexthop %s for address %s dist=%d met=%d",
 428                 __FILE__, __PRETTY_FUNCTION__,
 429                 lookup, max_lookup, nexthop_str, addr_str,
 430                 nexthop_tab[0].protocol_distance,
 431                 nexthop_tab[0].route_metric);
 432     }
 433
 434     addr = nexthop_addr; /* use nexthop addr for recursive lookup */
 435
 436   } /* for (max_lookup) */
 437
 438   if (PIM_DEBUG_ZEBRA) {
 439     char addr_str[100];
 440     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 441     zlog_warn("%s %s: lookup=%d/%d: failure searching recursive nexthop ifindex for address %s",
 442               __FILE__, __PRETTY_FUNCTION__,
 443               lookup, max_lookup, addr_str);
 444   }
 445
 446   return -2;
 447 }