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
  21 #include <zebra.h>
  22 #include "zebra/rib.h"
  23
  24 #include "log.h"
  25 #include "prefix.h"
  26 #include "zclient.h"
  27 #include "stream.h"
  28 #include "network.h"
  29 #include "thread.h"
  30
  31 #include "pimd.h"
  32 #include "pim_pim.h"
  33 #include "pim_str.h"
  34 #include "pim_zlookup.h"
  35
  36 extern int zclient_debug;
  37
  38 static void zclient_lookup_sched(struct zclient *zlookup, int delay);
  39
  40 /* Connect to zebra for nexthop lookup. */
  41 static int zclient_lookup_connect(struct thread *t)
  42 {
  43   struct zclient *zlookup;
  44
  45   zlookup = THREAD_ARG(t);
  46   zlookup->t_connect = NULL;
  47
  48   if (zlookup->sock >= 0) {
  49     return 0;
  50   }
  51
  52   if (zclient_socket_connect(zlookup) < 0) {
  53     ++zlookup->fail;
  54     zlog_warn("%s: failure connecting zclient socket: failures=%d",
  55               __PRETTY_FUNCTION__, zlookup->fail);
  56   }
  57   else {
  58     zlookup->fail = 0; /* reset counter on connection */
  59   }
  60
  61   zassert(!zlookup->t_connect);
  62   if (zlookup->sock < 0) {
  63     /* Since last connect failed, retry within 10 secs */
  64     zclient_lookup_sched(zlookup, 10);
  65     return -1;
  66   }
  67
  68   return 0;
  69 }
  70
  71 /* Schedule connection with delay. */
  72 static void zclient_lookup_sched(struct zclient *zlookup, int delay)
  73 {
  74   zassert(!zlookup->t_connect);
  75
  76   THREAD_TIMER_ON(master, zlookup->t_connect,
  77                   zclient_lookup_connect,
  78                   zlookup, delay);
  79
  80   zlog_notice("%s: zclient lookup connection scheduled for %d seconds",
  81               __PRETTY_FUNCTION__, delay);
  82 }
  83
  84 /* Schedule connection for now. */
  85 static void zclient_lookup_sched_now(struct zclient *zlookup)
  86 {
  87   zassert(!zlookup->t_connect);
  88
  89   zlookup->t_connect = thread_add_event(master, zclient_lookup_connect,
  90                                         zlookup, 0);
  91
  92   zlog_notice("%s: zclient lookup immediate connection scheduled",
  93               __PRETTY_FUNCTION__);
  94 }
  95
  96 /* Schedule reconnection, if needed. */
  97 static void zclient_lookup_reconnect(struct zclient *zlookup)
  98 {
  99   if (zlookup->t_connect) {
 100     return;
 101   }
 102
 103   zclient_lookup_sched_now(zlookup);
 104 }
 105
 106 static void zclient_lookup_failed(struct zclient *zlookup)
 107 {
 108   if (zlookup->sock >= 0) {
 109     if (close(zlookup->sock)) {
 110       zlog_warn("%s: closing fd=%d: errno=%d %s", __func__, zlookup->sock,
 111                 errno, safe_strerror(errno));
 112     }
 113     zlookup->sock = -1;
 114   }
 115
 116   zclient_lookup_reconnect(zlookup);
 117 }
 118
 119 struct zclient *zclient_lookup_new()
 120 {
 121   struct zclient *zlookup;
 122
 123   zlookup = zclient_new (master);
 124   if (!zlookup) {
 125     zlog_err("%s: zclient_new() failure",
 126              __PRETTY_FUNCTION__);
 127     return 0;
 128   }
 129
 130   zlookup->sock = -1;
 131   zlookup->ibuf = stream_new(ZEBRA_MAX_PACKET_SIZ);
 132   zlookup->obuf = stream_new(ZEBRA_MAX_PACKET_SIZ);
 133   zlookup->t_connect = 0;
 134
 135   zclient_lookup_sched_now(zlookup);
 136
 137   zlog_notice("%s: zclient lookup socket initialized",
 138               __PRETTY_FUNCTION__);
 139
 140   return zlookup;
 141 }
 142
 143 static int zclient_read_nexthop(struct zclient *zlookup,
 144                                 struct pim_zlookup_nexthop nexthop_tab[],
 145                                 const int tab_size,
 146                                 struct in_addr addr)
 147 {
 148   int num_ifindex = 0;
 149   struct stream *s;
 150   const uint16_t MIN_LEN = 10; /* getipv4=4 getc=1 getl=4 getc=1 */
 151   uint16_t length;
 152   u_char marker;
 153   u_char version;
 154   vrf_id_t vrf_id;
 155   uint16_t command = 0;
 156   struct in_addr raddr;
 157   uint8_t distance;
 158   uint32_t metric;
 159   int nexthop_num;
 160   int i, err;
 161
 162   if (PIM_DEBUG_ZEBRA) {
 163     char addr_str[100];
 164     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 165     zlog_debug("%s: addr=%s",
 166                __PRETTY_FUNCTION__,
 167                addr_str);
 168   }
 169
 170   s = zlookup->ibuf;
 171
 172   while (command != ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB)
 173     {
 174       stream_reset(s);
 175       err = zclient_read_header (s, zlookup->sock, &length, &marker, &version,
 176                                  &vrf_id, &command);
 177       if (err < 0) {
 178         zlog_err("%s %s: zclient_read_header() failed",
 179                  __FILE__, __PRETTY_FUNCTION__);
 180         zclient_lookup_failed(zlookup);
 181         return -1;
 182       }
 183
 184       if (length < MIN_LEN) {
 185         zlog_err("%s %s: failure reading zclient lookup socket: len=%d < MIN_LEN=%d",
 186                  __FILE__, __PRETTY_FUNCTION__, length, MIN_LEN);
 187         zclient_lookup_failed(zlookup);
 188         return -2;
 189       }
 190     }
 191
 192   raddr.s_addr = stream_get_ipv4(s);
 193
 194   if (raddr.s_addr != addr.s_addr) {
 195     char addr_str[100];
 196     char raddr_str[100];
 197     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 198     pim_inet4_dump("<raddr?>", raddr, raddr_str, sizeof(raddr_str));
 199     zlog_warn("%s: address mismatch: addr=%s raddr=%s",
 200                __PRETTY_FUNCTION__,
 201                addr_str, raddr_str);
 202     /* warning only */
 203   }
 204
 205   distance = stream_getc(s);
 206   metric = stream_getl(s);
 207   nexthop_num = stream_getc(s);
 208
 209   if (nexthop_num < 1) {
 210     zlog_err("%s: socket %d bad nexthop_num=%d",
 211             __func__, zlookup->sock, nexthop_num);
 212     return -6;
 213   }
 214
 215   length -= MIN_LEN;
 216
 217   for (i = 0; i < nexthop_num; ++i) {
 218     enum nexthop_types_t nexthop_type;
 219
 220     if (length < 1) {
 221       zlog_err("%s: socket %d empty input expecting nexthop_type: len=%d",
 222                __func__, zlookup->sock, length);
 223       return -7;
 224     }
 225
 226     nexthop_type = stream_getc(s);
 227     --length;
 228
 229     switch (nexthop_type) {
 230     case NEXTHOP_TYPE_IFINDEX:
 231     case NEXTHOP_TYPE_IPV4_IFINDEX:
 232       if (num_ifindex >= tab_size) {
 233         char addr_str[100];
 234         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 235         zlog_warn("%s %s: found too many nexthop ifindexes (%d > %d) for address %s",
 236                  __FILE__, __PRETTY_FUNCTION__,
 237                  (num_ifindex + 1), tab_size, addr_str);
 238         return num_ifindex;
 239       }
 240       if (nexthop_type == NEXTHOP_TYPE_IPV4_IFINDEX) {
 241         if (length < 4) {
 242           zlog_err("%s: socket %d short input expecting nexthop IPv4-addr: len=%d",
 243                    __func__, zlookup->sock, length);
 244           return -8;
 245         }
 246         nexthop_tab[num_ifindex].nexthop_addr.s_addr = stream_get_ipv4(s);
 247         length -= 4;
 248       }
 249       else {
 250         nexthop_tab[num_ifindex].nexthop_addr.s_addr = PIM_NET_INADDR_ANY;
 251       }
 252       nexthop_tab[num_ifindex].ifindex           = stream_getl(s);
 253       nexthop_tab[num_ifindex].protocol_distance = distance;
 254       nexthop_tab[num_ifindex].route_metric      = metric;
 255       ++num_ifindex;
 256       break;
 257     case NEXTHOP_TYPE_IPV4:
 258       if (num_ifindex >= tab_size) {
 259         char addr_str[100];
 260         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 261         zlog_warn("%s %s: found too many nexthop ifindexes (%d > %d) for address %s",
 262                  __FILE__, __PRETTY_FUNCTION__,
 263                  (num_ifindex + 1), tab_size, addr_str);
 264         return num_ifindex;
 265       }
 266       nexthop_tab[num_ifindex].nexthop_addr.s_addr = stream_get_ipv4(s);
 267       length -= 4;
 268       nexthop_tab[num_ifindex].ifindex             = 0;
 269       nexthop_tab[num_ifindex].protocol_distance   = distance;
 270       nexthop_tab[num_ifindex].route_metric        = metric;
 271       if (PIM_DEBUG_ZEBRA) {
 272         char addr_str[100];
 273         char nexthop_str[100];
 274         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 275         pim_inet4_dump("<nexthop?>", nexthop_tab[num_ifindex].nexthop_addr, nexthop_str, sizeof(nexthop_str));
 276         zlog_debug("%s %s: zebra returned recursive nexthop %s for address %s",
 277                    __FILE__, __PRETTY_FUNCTION__,
 278                    nexthop_str, addr_str);
 279       }
 280       ++num_ifindex;
 281       break;
 282     default:
 283       /* do nothing */
 284       {
 285         char addr_str[100];
 286         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 287         zlog_warn("%s %s: found non-ifindex nexthop type=%d for address %s",
 288                  __FILE__, __PRETTY_FUNCTION__,
 289                   nexthop_type, addr_str);
 290       }
 291       break;
 292     }
 293   }
 294
 295   return num_ifindex;
 296 }
 297
 298 static int zclient_lookup_nexthop_once(struct zclient *zlookup,
 299                                        struct pim_zlookup_nexthop nexthop_tab[],
 300                                        const int tab_size,
 301                                        struct in_addr addr)
 302 {
 303   struct stream *s;
 304   int ret;
 305
 306   if (PIM_DEBUG_ZEBRA) {
 307     char addr_str[100];
 308     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 309     zlog_debug("%s: addr=%s",
 310                __PRETTY_FUNCTION__,
 311                addr_str);
 312   }
 313
 314   /* Check socket. */
 315   if (zlookup->sock < 0) {
 316     zlog_err("%s %s: zclient lookup socket is not connected",
 317              __FILE__, __PRETTY_FUNCTION__);
 318     zclient_lookup_failed(zlookup);
 319     return -1;
 320   }
 321
 322   s = zlookup->obuf;
 323   stream_reset(s);
 324   zclient_create_header(s, ZEBRA_IPV4_NEXTHOP_LOOKUP_MRIB, VRF_DEFAULT);
 325   stream_put_in_addr(s, &addr);
 326   stream_putw_at(s, 0, stream_get_endp(s));
 327
 328   ret = writen(zlookup->sock, s->data, stream_get_endp(s));
 329   if (ret < 0) {
 330     zlog_err("%s %s: writen() failure writing to zclient lookup socket",
 331              __FILE__, __PRETTY_FUNCTION__);
 332     zclient_lookup_failed(zlookup);
 333     return -2;
 334   }
 335   if (ret == 0) {
 336     zlog_err("%s %s: connection closed on zclient lookup socket",
 337              __FILE__, __PRETTY_FUNCTION__);
 338     zclient_lookup_failed(zlookup);
 339     return -3;
 340   }
 341
 342   return zclient_read_nexthop(zlookup, nexthop_tab,
 343                               tab_size, addr);
 344 }
 345
 346 int zclient_lookup_nexthop(struct zclient *zlookup,
 347                            struct pim_zlookup_nexthop nexthop_tab[],
 348                            const int tab_size,
 349                            struct in_addr addr,
 350                            int max_lookup)
 351 {
 352   int lookup;
 353   uint32_t route_metric = 0xFFFFFFFF;
 354   uint8_t  protocol_distance = 0xFF;
 355
 356   for (lookup = 0; lookup < max_lookup; ++lookup) {
 357     int num_ifindex;
 358     int first_ifindex;
 359     struct in_addr nexthop_addr;
 360
 361     num_ifindex = zclient_lookup_nexthop_once(qpim_zclient_lookup, nexthop_tab,
 362                                               PIM_NEXTHOP_IFINDEX_TAB_SIZE, addr);
 363     if (num_ifindex < 1) {
 364       if (PIM_DEBUG_ZEBRA) {
 365         char addr_str[100];
 366         pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 367         zlog_debug("%s %s: lookup=%d/%d: could not find nexthop ifindex for address %s",
 368                    __FILE__, __PRETTY_FUNCTION__,
 369                    lookup, max_lookup, addr_str);
 370       }
 371       return -1;
 372     }
 373
 374     if (lookup < 1) {
 375       /* this is the non-recursive lookup - save original metric/distance */
 376       route_metric = nexthop_tab[0].route_metric;
 377       protocol_distance = nexthop_tab[0].protocol_distance;
 378     }
 379
 380     /*
 381       FIXME: Non-recursive nexthop ensured only for first ifindex.
 382       However, recursive route lookup should really be fixed in zebra daemon.
 383       See also TODO T24.
 384      */
 385     first_ifindex = nexthop_tab[0].ifindex;
 386     nexthop_addr = nexthop_tab[0].nexthop_addr;
 387     if (first_ifindex > 0) {
 388       /* found: first ifindex is non-recursive nexthop */
 389
 390       if (lookup > 0) {
 391         /* Report non-recursive success after first lookup */
 392         if (PIM_DEBUG_ZEBRA) {
 393           char addr_str[100];
 394           pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 395           zlog_debug("%s %s: lookup=%d/%d: found non-recursive ifindex=%d for address %s dist=%d met=%d",
 396                      __FILE__, __PRETTY_FUNCTION__,
 397                      lookup, max_lookup, first_ifindex, addr_str,
 398                      nexthop_tab[0].protocol_distance,
 399                      nexthop_tab[0].route_metric);
 400         }
 401
 402         /* use last address as nexthop address */
 403         nexthop_tab[0].nexthop_addr = addr;
 404
 405         /* report original route metric/distance */
 406         nexthop_tab[0].route_metric = route_metric;
 407         nexthop_tab[0].protocol_distance = protocol_distance;
 408       }
 409
 410       return num_ifindex;
 411     }
 412
 413     if (PIM_DEBUG_ZEBRA) {
 414       char addr_str[100];
 415       char nexthop_str[100];
 416       pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 417       pim_inet4_dump("<nexthop?>", nexthop_addr, nexthop_str, sizeof(nexthop_str));
 418       zlog_debug("%s %s: lookup=%d/%d: zebra returned recursive nexthop %s for address %s dist=%d met=%d",
 419                 __FILE__, __PRETTY_FUNCTION__,
 420                 lookup, max_lookup, nexthop_str, addr_str,
 421                 nexthop_tab[0].protocol_distance,
 422                 nexthop_tab[0].route_metric);
 423     }
 424
 425     addr = nexthop_addr; /* use nexthop addr for recursive lookup */
 426
 427   } /* for (max_lookup) */
 428
 429   if (PIM_DEBUG_ZEBRA) {
 430     char addr_str[100];
 431     pim_inet4_dump("<addr?>", addr, addr_str, sizeof(addr_str));
 432     zlog_warn("%s %s: lookup=%d/%d: failure searching recursive nexthop ifindex for address %s",
 433               __FILE__, __PRETTY_FUNCTION__,
 434               lookup, max_lookup, addr_str);
 435   }
 436
 437   return -2;
 438 }