lib/nexthop.c

   1 /* A generic nexthop structure
   2  * Copyright (C) 2013 Cumulus Networks, Inc.
   3  *
   4  * This file is part of Quagga.
   5  *
   6  * Quagga is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License as published by the
   8  * Free Software Foundation; either version 2, or (at your option) any
   9  * later version.
  10  *
  11  * Quagga is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20 #include <zebra.h>
  21
  22 #include "prefix.h"
  23 #include "table.h"
  24 #include "memory.h"
  25 #include "command.h"
  26 #include "if.h"
  27 #include "log.h"
  28 #include "sockunion.h"
  29 #include "linklist.h"
  30 #include "thread.h"
  31 #include "prefix.h"
  32 #include "nexthop.h"
  33 #include "mpls.h"
  34 #include "jhash.h"
  35
  36 DEFINE_MTYPE_STATIC(LIB, NEXTHOP, "Nexthop")
  37 DEFINE_MTYPE_STATIC(LIB, NH_LABEL, "Nexthop label")
  38
  39 /* check if nexthops are same, non-recursive */
  40 int nexthop_same_no_recurse(const struct nexthop *next1,
  41                             const struct nexthop *next2)
  42 {
  43         if (next1->type != next2->type)
  44                 return 0;
  45
  46         switch (next1->type) {
  47         case NEXTHOP_TYPE_IPV4:
  48         case NEXTHOP_TYPE_IPV4_IFINDEX:
  49                 if (!IPV4_ADDR_SAME(&next1->gate.ipv4, &next2->gate.ipv4))
  50                         return 0;
  51                 if (next1->ifindex && (next1->ifindex != next2->ifindex))
  52                         return 0;
  53                 break;
  54         case NEXTHOP_TYPE_IFINDEX:
  55                 if (next1->ifindex != next2->ifindex)
  56                         return 0;
  57                 break;
  58         case NEXTHOP_TYPE_IPV6:
  59                 if (!IPV6_ADDR_SAME(&next1->gate.ipv6, &next2->gate.ipv6))
  60                         return 0;
  61                 break;
  62         case NEXTHOP_TYPE_IPV6_IFINDEX:
  63                 if (!IPV6_ADDR_SAME(&next1->gate.ipv6, &next2->gate.ipv6))
  64                         return 0;
  65                 if (next1->ifindex != next2->ifindex)
  66                         return 0;
  67                 break;
  68         default:
  69                 /* do nothing */
  70                 break;
  71         }
  72         return 1;
  73 }
  74
  75 int nexthop_same_firsthop(struct nexthop *next1, struct nexthop *next2)
  76 {
  77         int type1 = NEXTHOP_FIRSTHOPTYPE(next1->type);
  78         int type2 = NEXTHOP_FIRSTHOPTYPE(next2->type);
  79
  80         if (type1 != type2)
  81                 return 0;
  82         switch (type1) {
  83         case NEXTHOP_TYPE_IPV4_IFINDEX:
  84                 if (!IPV4_ADDR_SAME(&next1->gate.ipv4, &next2->gate.ipv4))
  85                         return 0;
  86                 if (next1->ifindex != next2->ifindex)
  87                         return 0;
  88                 break;
  89         case NEXTHOP_TYPE_IFINDEX:
  90                 if (next1->ifindex != next2->ifindex)
  91                         return 0;
  92                 break;
  93         case NEXTHOP_TYPE_IPV6_IFINDEX:
  94                 if (!IPV6_ADDR_SAME(&next1->gate.ipv6, &next2->gate.ipv6))
  95                         return 0;
  96                 if (next1->ifindex != next2->ifindex)
  97                         return 0;
  98                 break;
  99         default:
 100                 /* do nothing */
 101                 break;
 102         }
 103         return 1;
 104 }
 105
 106 /*
 107  * nexthop_type_to_str
 108  */
 109 const char *nexthop_type_to_str(enum nexthop_types_t nh_type)
 110 {
 111         static const char *desc[] = {
 112                 "none",          "Directly connected",
 113                 "IPv4 nexthop",  "IPv4 nexthop with ifindex",
 114                 "IPv6 nexthop",  "IPv6 nexthop with ifindex",
 115                 "Null0 nexthop",
 116         };
 117
 118         return desc[nh_type];
 119 }
 120
 121 /*
 122  * Check if the labels match for the 2 nexthops specified.
 123  */
 124 int nexthop_labels_match(struct nexthop *nh1, struct nexthop *nh2)
 125 {
 126         struct mpls_label_stack *nhl1, *nhl2;
 127
 128         nhl1 = nh1->nh_label;
 129         nhl2 = nh2->nh_label;
 130         if (!nhl1 || !nhl2)
 131                 return 0;
 132
 133         if (nhl1->num_labels != nhl2->num_labels)
 134                 return 0;
 135
 136         if (memcmp(nhl1->label, nhl2->label, nhl1->num_labels))
 137                 return 0;
 138
 139         return 1;
 140 }
 141
 142 struct nexthop *nexthop_new(void)
 143 {
 144         return XCALLOC(MTYPE_NEXTHOP, sizeof(struct nexthop));
 145 }
 146
 147 /* Free nexthop. */
 148 void nexthop_free(struct nexthop *nexthop)
 149 {
 150         nexthop_del_labels(nexthop);
 151         if (nexthop->resolved)
 152                 nexthops_free(nexthop->resolved);
 153         XFREE(MTYPE_NEXTHOP, nexthop);
 154 }
 155
 156 /* Frees a list of nexthops */
 157 void nexthops_free(struct nexthop *nexthop)
 158 {
 159         struct nexthop *nh, *next;
 160
 161         for (nh = nexthop; nh; nh = next) {
 162                 next = nh->next;
 163                 nexthop_free(nh);
 164         }
 165 }
 166
 167 bool nexthop_same(const struct nexthop *nh1, const struct nexthop *nh2)
 168 {
 169         if (nh1 && !nh2)
 170                 return false;
 171
 172         if (!nh1 && nh2)
 173                 return false;
 174
 175         if (nh1 == nh2)
 176                 return true;
 177
 178         if (nh1->vrf_id != nh2->vrf_id)
 179                 return false;
 180
 181         if (nh1->type != nh2->type)
 182                 return false;
 183
 184         switch (nh1->type) {
 185         case NEXTHOP_TYPE_IFINDEX:
 186                 if (nh1->ifindex != nh2->ifindex)
 187                         return false;
 188                 break;
 189         case NEXTHOP_TYPE_IPV4:
 190                 if (nh1->gate.ipv4.s_addr != nh2->gate.ipv4.s_addr)
 191                         return false;
 192                 break;
 193         case NEXTHOP_TYPE_IPV4_IFINDEX:
 194                 if (nh1->gate.ipv4.s_addr != nh2->gate.ipv4.s_addr)
 195                         return false;
 196                 if (nh1->ifindex != nh2->ifindex)
 197                         return false;
 198                 break;
 199         case NEXTHOP_TYPE_IPV6:
 200                 if (memcmp(&nh1->gate.ipv6, &nh2->gate.ipv6, 16))
 201                         return false;
 202                 break;
 203         case NEXTHOP_TYPE_IPV6_IFINDEX:
 204                 if (memcmp(&nh1->gate.ipv6, &nh2->gate.ipv6, 16))
 205                         return false;
 206                 if (nh1->ifindex != nh2->ifindex)
 207                         return false;
 208                 break;
 209         case NEXTHOP_TYPE_BLACKHOLE:
 210                 if (nh1->bh_type != nh2->bh_type)
 211                         return false;
 212                 break;
 213         }
 214
 215         return true;
 216 }
 217
 218 /* Update nexthop with label information. */
 219 void nexthop_add_labels(struct nexthop *nexthop, enum lsp_types_t type,
 220                         uint8_t num_labels, mpls_label_t *label)
 221 {
 222         struct mpls_label_stack *nh_label;
 223         int i;
 224
 225         nexthop->nh_label_type = type;
 226         nh_label = XCALLOC(MTYPE_NH_LABEL,
 227                            sizeof(struct mpls_label_stack)
 228                                    + num_labels * sizeof(mpls_label_t));
 229         nh_label->num_labels = num_labels;
 230         for (i = 0; i < num_labels; i++)
 231                 nh_label->label[i] = *(label + i);
 232         nexthop->nh_label = nh_label;
 233 }
 234
 235 /* Free label information of nexthop, if present. */
 236 void nexthop_del_labels(struct nexthop *nexthop)
 237 {
 238         if (nexthop->nh_label) {
 239                 XFREE(MTYPE_NH_LABEL, nexthop->nh_label);
 240                 nexthop->nh_label_type = ZEBRA_LSP_NONE;
 241         }
 242 }
 243
 244 const char *nexthop2str(const struct nexthop *nexthop, char *str, int size)
 245 {
 246         switch (nexthop->type) {
 247         case NEXTHOP_TYPE_IFINDEX:
 248                 snprintf(str, size, "if %u", nexthop->ifindex);
 249                 break;
 250         case NEXTHOP_TYPE_IPV4:
 251         case NEXTHOP_TYPE_IPV4_IFINDEX:
 252                 snprintf(str, size, "%s if %u", inet_ntoa(nexthop->gate.ipv4),
 253                          nexthop->ifindex);
 254                 break;
 255         case NEXTHOP_TYPE_IPV6:
 256         case NEXTHOP_TYPE_IPV6_IFINDEX:
 257                 snprintf(str, size, "%s if %u", inet6_ntoa(nexthop->gate.ipv6),
 258                          nexthop->ifindex);
 259                 break;
 260         case NEXTHOP_TYPE_BLACKHOLE:
 261                 snprintf(str, size, "blackhole");
 262                 break;
 263         default:
 264                 snprintf(str, size, "unknown");
 265                 break;
 266         }
 267
 268         return str;
 269 }
 270
 271 /*
 272  * Iteration step for ALL_NEXTHOPS macro:
 273  * This is the tricky part. Check if `nexthop' has
 274  * NEXTHOP_FLAG_RECURSIVE set. If yes, this implies that `nexthop' has
 275  * at least one nexthop attached to `nexthop->resolved', which will be
 276  * the next one.
 277  *
 278  * If NEXTHOP_FLAG_RECURSIVE is not set, `nexthop' will progress in its
 279  * current chain. In case its current chain end is reached, it will move
 280  * upwards in the recursion levels and progress there. Whenever a step
 281  * forward in a chain is done, recursion will be checked again.
 282  * In a nustshell, it's equivalent to a pre-traversal order assuming that
 283  * left branch is 'resolved' and right branch is 'next':
 284  * https://en.wikipedia.org/wiki/Tree_traversal#/media/File:Sorted_binary_tree_preorder.svg
 285  */
 286 struct nexthop *nexthop_next(struct nexthop *nexthop)
 287 {
 288         if (CHECK_FLAG(nexthop->flags, NEXTHOP_FLAG_RECURSIVE))
 289                 return nexthop->resolved;
 290
 291         if (nexthop->next)
 292                 return nexthop->next;
 293
 294         for (struct nexthop *par = nexthop->rparent; par; par = par->rparent)
 295                 if (par->next)
 296                         return par->next;
 297
 298         return NULL;
 299 }
 300
 301 unsigned int nexthop_level(struct nexthop *nexthop)
 302 {
 303         unsigned int rv = 0;
 304
 305         for (struct nexthop *par = nexthop->rparent; par; par = par->rparent)
 306                 rv++;
 307
 308         return rv;
 309 }
 310
 311 uint32_t nexthop_hash(struct nexthop *nexthop)
 312 {
 313         uint32_t key;
 314
 315         key = jhash_1word(nexthop->vrf_id, 0x45afe398);
 316         key = jhash_1word(nexthop->ifindex, key);
 317         key = jhash_1word(nexthop->type, key);
 318         key = jhash(&nexthop->gate, sizeof(union g_addr), key);
 319
 320         return key;
 321 }