bgpd/bgp_attr_evpn.c

   1 /* Ethernet-VPN Attribute handling file
   2  * Copyright (C) 2016 6WIND
   3  *
   4  * This file is part of FRRouting.
   5  *
   6  * FRRouting 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  * FRRouting 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
  21 #include <zebra.h>
  22
  23 #include "command.h"
  24 #include "filter.h"
  25 #include "prefix.h"
  26 #include "log.h"
  27 #include "memory.h"
  28 #include "stream.h"
  29 #include "vxlan.h"
  30
  31 #include "bgpd/bgpd.h"
  32 #include "bgpd/bgp_attr.h"
  33 #include "bgpd/bgp_route.h"
  34 #include "bgpd/bgp_attr_evpn.h"
  35 #include "bgpd/bgp_ecommunity.h"
  36 #include "bgpd/bgp_evpn.h"
  37 #include "bgpd/bgp_evpn_private.h"
  38
  39 bool bgp_route_evpn_same(const struct bgp_route_evpn *e1,
  40                          const struct bgp_route_evpn *e2)
  41 {
  42         return (e1->type == e2->type &&
  43                 !memcmp(&(e1->eth_s_id), &(e2->eth_s_id), sizeof(esi_t)) &&
  44                 !ipaddr_cmp(&(e1->gw_ip), &(e2->gw_ip)));
  45 }
  46
  47 void bgp_add_routermac_ecom(struct attr *attr, struct ethaddr *routermac)
  48 {
  49         struct ecommunity_val routermac_ecom;
  50         struct ecommunity *ecomm = bgp_attr_get_ecommunity(attr);
  51
  52         memset(&routermac_ecom, 0, sizeof(routermac_ecom));
  53         routermac_ecom.val[0] = ECOMMUNITY_ENCODE_EVPN;
  54         routermac_ecom.val[1] = ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC;
  55         memcpy(&routermac_ecom.val[2], routermac->octet, ETH_ALEN);
  56         if (!ecomm) {
  57                 bgp_attr_set_ecommunity(attr, ecommunity_new());
  58                 ecomm = bgp_attr_get_ecommunity(attr);
  59         }
  60         ecommunity_add_val(ecomm, &routermac_ecom, false, false);
  61         ecommunity_str(ecomm);
  62 }
  63
  64 /* converts to an esi
  65  * returns 1 on success, 0 otherwise
  66  * format accepted: AA:BB:CC:DD:EE:FF:GG:HH:II:JJ
  67  * if id is null, check only is done
  68  */
  69 bool str2esi(const char *str, esi_t *id)
  70 {
  71         unsigned int a[ESI_BYTES];
  72         int i;
  73
  74         if (!str)
  75                 return false;
  76         if (sscanf(str, "%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x", a + 0, a + 1,
  77                    a + 2, a + 3, a + 4, a + 5, a + 6, a + 7, a + 8, a + 9)
  78             != ESI_BYTES) {
  79                 /* error in incoming str length */
  80                 return false;
  81         }
  82         /* valid mac address */
  83         if (!id)
  84                 return true;
  85         for (i = 0; i < ESI_BYTES; ++i)
  86                 id->val[i] = a[i] & 0xff;
  87         return true;
  88 }
  89
  90 char *ecom_mac2str(char *ecom_mac)
  91 {
  92         char *en;
  93
  94         en = ecom_mac;
  95         en += 2;
  96
  97         return prefix_mac2str((struct ethaddr *)en, NULL, 0);
  98 }
  99
 100 /* Fetch router-mac from extended community */
 101 bool bgp_attr_rmac(struct attr *attr, struct ethaddr *rmac)
 102 {
 103         uint32_t i = 0;
 104         struct ecommunity *ecom;
 105
 106         ecom = bgp_attr_get_ecommunity(attr);
 107         if (!ecom || !ecom->size)
 108                 return false;
 109
 110         /* If there is a router mac extended community, set RMAC in attr */
 111         for (i = 0; i < ecom->size; i++) {
 112                 uint8_t *pnt = NULL;
 113                 uint8_t type = 0;
 114                 uint8_t sub_type = 0;
 115
 116                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 117                 type = *pnt++;
 118                 sub_type = *pnt++;
 119
 120                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 121                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC))
 122                         continue;
 123
 124                 memcpy(rmac, pnt, ETH_ALEN);
 125                 return true;
 126         }
 127         return false;
 128 }
 129
 130 /*
 131  * return true if attr contains default gw extended community
 132  */
 133 uint8_t bgp_attr_default_gw(struct attr *attr)
 134 {
 135         struct ecommunity *ecom;
 136         uint32_t i;
 137
 138         ecom = bgp_attr_get_ecommunity(attr);
 139         if (!ecom || !ecom->size)
 140                 return 0;
 141
 142         /* If there is a default gw extendd community return true otherwise
 143          * return 0 */
 144         for (i = 0; i < ecom->size; i++) {
 145                 uint8_t *pnt;
 146                 uint8_t type, sub_type;
 147
 148                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 149                 type = *pnt++;
 150                 sub_type = *pnt++;
 151
 152                 if ((type == ECOMMUNITY_ENCODE_OPAQUE
 153                      && sub_type == ECOMMUNITY_EVPN_SUBTYPE_DEF_GW))
 154                         return 1;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /*
 161  * Fetch and return the DF preference and algorithm from
 162  * DF election extended community, if present, else 0.
 163  */
 164 uint16_t bgp_attr_df_pref_from_ec(struct attr *attr, uint8_t *alg)
 165 {
 166         struct ecommunity *ecom;
 167         uint32_t i;
 168         uint16_t df_pref = 0;
 169
 170         *alg = EVPN_MH_DF_ALG_SERVICE_CARVING;
 171         ecom = bgp_attr_get_ecommunity(attr);
 172         if (!ecom || !ecom->size)
 173                 return 0;
 174
 175         for (i = 0; i < ecom->size; i++) {
 176                 uint8_t *pnt;
 177                 uint8_t type, sub_type;
 178
 179                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 180                 type = *pnt++;
 181                 sub_type = *pnt++;
 182                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 183                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_DF_ELECTION))
 184                         continue;
 185
 186                 *alg = (*pnt++) & ECOMMUNITY_EVPN_SUBTYPE_DF_ALG_BITS;
 187
 188                 pnt += 3;
 189                 pnt = ptr_get_be16(pnt, &df_pref);
 190                 (void)pnt; /* consume value */
 191                 break;
 192         }
 193
 194         return df_pref;
 195 }
 196
 197 /*
 198  * Fetch and return the sequence number from MAC Mobility extended
 199  * community, if present, else 0.
 200  */
 201 uint32_t bgp_attr_mac_mobility_seqnum(struct attr *attr, uint8_t *sticky)
 202 {
 203         struct ecommunity *ecom;
 204         uint32_t i;
 205         uint8_t flags = 0;
 206
 207         ecom = bgp_attr_get_ecommunity(attr);
 208         if (!ecom || !ecom->size)
 209                 return 0;
 210
 211         /* If there is a MAC Mobility extended community, return its
 212          * sequence number.
 213          * TODO: RFC is silent on handling of multiple MAC mobility extended
 214          * communities for the same route. We will bail out upon the first
 215          * one.
 216          */
 217         for (i = 0; i < ecom->size; i++) {
 218                 const uint8_t *pnt;
 219                 uint8_t type, sub_type;
 220                 uint32_t seq_num;
 221
 222                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 223                 type = *pnt++;
 224                 sub_type = *pnt++;
 225                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 226                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY))
 227                         continue;
 228                 flags = *pnt++;
 229
 230                 if (flags & ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY_FLAG_STICKY)
 231                         *sticky = 1;
 232                 else
 233                         *sticky = 0;
 234
 235                 pnt++;
 236                 pnt = ptr_get_be32(pnt, &seq_num);
 237                 (void)pnt; /* consume value */
 238                 return seq_num;
 239         }
 240
 241         return 0;
 242 }
 243
 244 /*
 245  * return true if attr contains router flag extended community
 246  */
 247 void bgp_attr_evpn_na_flag(struct attr *attr,
 248                 uint8_t *router_flag, bool *proxy)
 249 {
 250         struct ecommunity *ecom;
 251         uint32_t i;
 252         uint8_t val;
 253
 254         ecom = bgp_attr_get_ecommunity(attr);
 255         if (!ecom || !ecom->size)
 256                 return;
 257
 258         /* If there is a evpn na extendd community set router_flag */
 259         for (i = 0; i < ecom->size; i++) {
 260                 uint8_t *pnt;
 261                 uint8_t type, sub_type;
 262
 263                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 264                 type = *pnt++;
 265                 sub_type = *pnt++;
 266
 267                 if (type == ECOMMUNITY_ENCODE_EVPN &&
 268                     sub_type == ECOMMUNITY_EVPN_SUBTYPE_ND) {
 269                         val = *pnt++;
 270
 271                         if (val & ECOMMUNITY_EVPN_SUBTYPE_ND_ROUTER_FLAG)
 272                                 *router_flag = 1;
 273
 274                         if (val & ECOMMUNITY_EVPN_SUBTYPE_PROXY_FLAG)
 275                                 *proxy = true;
 276
 277                         break;
 278                 }
 279         }
 280 }
 281
 282 /* dst prefix must be AF_INET or AF_INET6 prefix, to forge EVPN prefix */
 283 extern int bgp_build_evpn_prefix(int evpn_type, uint32_t eth_tag,
 284                                  struct prefix *dst)
 285 {
 286         struct evpn_addr *p_evpn_p;
 287         struct prefix p2;
 288         struct prefix *src = &p2;
 289
 290         if (!dst || dst->family == 0)
 291                 return -1;
 292         /* store initial prefix in src */
 293         prefix_copy(src, dst);
 294         memset(dst, 0, sizeof(struct prefix));
 295         p_evpn_p = &(dst->u.prefix_evpn);
 296         dst->family = AF_EVPN;
 297         p_evpn_p->route_type = evpn_type;
 298         if (evpn_type == BGP_EVPN_IP_PREFIX_ROUTE) {
 299                 p_evpn_p->prefix_addr.eth_tag = eth_tag;
 300                 p_evpn_p->prefix_addr.ip_prefix_length = p2.prefixlen;
 301                 if (src->family == AF_INET) {
 302                         SET_IPADDR_V4(&p_evpn_p->prefix_addr.ip);
 303                         memcpy(&p_evpn_p->prefix_addr.ip.ipaddr_v4,
 304                                &src->u.prefix4,
 305                                sizeof(struct in_addr));
 306                         dst->prefixlen = (uint16_t)PREFIX_LEN_ROUTE_TYPE_5_IPV4;
 307                 } else {
 308                         SET_IPADDR_V6(&p_evpn_p->prefix_addr.ip);
 309                         memcpy(&p_evpn_p->prefix_addr.ip.ipaddr_v6,
 310                                &src->u.prefix6,
 311                                sizeof(struct in6_addr));
 312                         dst->prefixlen = (uint16_t)PREFIX_LEN_ROUTE_TYPE_5_IPV6;
 313                 }
 314         } else
 315                 return -1;
 316         return 0;
 317 }