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 void bgp_add_routermac_ecom(struct attr *attr, struct ethaddr *routermac)
  40 {
  41         struct ecommunity_val routermac_ecom;
  42
  43         memset(&routermac_ecom, 0, sizeof(struct ecommunity_val));
  44         routermac_ecom.val[0] = ECOMMUNITY_ENCODE_EVPN;
  45         routermac_ecom.val[1] = ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC;
  46         memcpy(&routermac_ecom.val[2], routermac->octet, ETH_ALEN);
  47         if (!attr->ecommunity)
  48                 attr->ecommunity = ecommunity_new();
  49         ecommunity_add_val(attr->ecommunity, &routermac_ecom, false, false);
  50         ecommunity_str(attr->ecommunity);
  51 }
  52
  53 /* converts to an esi
  54  * returns 1 on success, 0 otherwise
  55  * format accepted: AA:BB:CC:DD:EE:FF:GG:HH:II:JJ
  56  * if id is null, check only is done
  57  */
  58 bool str2esi(const char *str, esi_t *id)
  59 {
  60         unsigned int a[ESI_BYTES];
  61         int i;
  62
  63         if (!str)
  64                 return false;
  65         if (sscanf(str, "%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x", a + 0, a + 1,
  66                    a + 2, a + 3, a + 4, a + 5, a + 6, a + 7, a + 8, a + 9)
  67             != ESI_BYTES) {
  68                 /* error in incoming str length */
  69                 return false;
  70         }
  71         /* valid mac address */
  72         if (!id)
  73                 return true;
  74         for (i = 0; i < ESI_BYTES; ++i)
  75                 id->val[i] = a[i] & 0xff;
  76         return true;
  77 }
  78
  79 char *ecom_mac2str(char *ecom_mac)
  80 {
  81         char *en;
  82
  83         en = ecom_mac;
  84         en += 2;
  85
  86         return prefix_mac2str((struct ethaddr *)en, NULL, 0);
  87 }
  88
  89 /* Fetch router-mac from extended community */
  90 bool bgp_attr_rmac(struct attr *attr, struct ethaddr *rmac)
  91 {
  92         int i = 0;
  93         struct ecommunity *ecom;
  94
  95         ecom = attr->ecommunity;
  96         if (!ecom || !ecom->size)
  97                 return false;
  98
  99         /* If there is a router mac extended community, set RMAC in attr */
 100         for (i = 0; i < ecom->size; i++) {
 101                 uint8_t *pnt = NULL;
 102                 uint8_t type = 0;
 103                 uint8_t sub_type = 0;
 104
 105                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 106                 type = *pnt++;
 107                 sub_type = *pnt++;
 108
 109                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 110                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC))
 111                         continue;
 112
 113                 memcpy(rmac, pnt, ETH_ALEN);
 114                 return true;
 115         }
 116         return false;
 117 }
 118
 119 /*
 120  * return true if attr contains default gw extended community
 121  */
 122 uint8_t bgp_attr_default_gw(struct attr *attr)
 123 {
 124         struct ecommunity *ecom;
 125         int i;
 126
 127         ecom = attr->ecommunity;
 128         if (!ecom || !ecom->size)
 129                 return 0;
 130
 131         /* If there is a default gw extendd community return true otherwise
 132          * return 0 */
 133         for (i = 0; i < ecom->size; i++) {
 134                 uint8_t *pnt;
 135                 uint8_t type, sub_type;
 136
 137                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 138                 type = *pnt++;
 139                 sub_type = *pnt++;
 140
 141                 if ((type == ECOMMUNITY_ENCODE_OPAQUE
 142                      && sub_type == ECOMMUNITY_EVPN_SUBTYPE_DEF_GW))
 143                         return 1;
 144         }
 145
 146         return 0;
 147 }
 148
 149 /*
 150  * Fetch and return the DF preference and algorithm from
 151  * DF election extended community, if present, else 0.
 152  */
 153 uint16_t bgp_attr_df_pref_from_ec(struct attr *attr, uint8_t *alg)
 154 {
 155         struct ecommunity *ecom;
 156         int i;
 157         uint16_t df_pref = 0;
 158
 159         *alg = EVPN_MH_DF_ALG_SERVICE_CARVING;
 160         ecom = attr->ecommunity;
 161         if (!ecom || !ecom->size)
 162                 return 0;
 163
 164         for (i = 0; i < ecom->size; i++) {
 165                 uint8_t *pnt;
 166                 uint8_t type, sub_type;
 167
 168                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 169                 type = *pnt++;
 170                 sub_type = *pnt++;
 171                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 172                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_DF_ELECTION))
 173                         continue;
 174
 175                 *alg = (*pnt++) & ECOMMUNITY_EVPN_SUBTYPE_DF_ALG_BITS;
 176
 177                 pnt += 3;
 178                 pnt = ptr_get_be16(pnt, &df_pref);
 179                 (void)pnt; /* consume value */
 180                 break;
 181         }
 182
 183         return df_pref;
 184 }
 185
 186 /*
 187  * Fetch and return the sequence number from MAC Mobility extended
 188  * community, if present, else 0.
 189  */
 190 uint32_t bgp_attr_mac_mobility_seqnum(struct attr *attr, uint8_t *sticky)
 191 {
 192         struct ecommunity *ecom;
 193         int i;
 194         uint8_t flags = 0;
 195
 196         ecom = attr->ecommunity;
 197         if (!ecom || !ecom->size)
 198                 return 0;
 199
 200         /* If there is a MAC Mobility extended community, return its
 201          * sequence number.
 202          * TODO: RFC is silent on handling of multiple MAC mobility extended
 203          * communities for the same route. We will bail out upon the first
 204          * one.
 205          */
 206         for (i = 0; i < ecom->size; i++) {
 207                 const uint8_t *pnt;
 208                 uint8_t type, sub_type;
 209                 uint32_t seq_num;
 210
 211                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 212                 type = *pnt++;
 213                 sub_type = *pnt++;
 214                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 215                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY))
 216                         continue;
 217                 flags = *pnt++;
 218
 219                 if (flags & ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY_FLAG_STICKY)
 220                         *sticky = 1;
 221                 else
 222                         *sticky = 0;
 223
 224                 pnt++;
 225                 pnt = ptr_get_be32(pnt, &seq_num);
 226                 (void)pnt; /* consume value */
 227                 return seq_num;
 228         }
 229
 230         return 0;
 231 }
 232
 233 /*
 234  * return true if attr contains router flag extended community
 235  */
 236 void bgp_attr_evpn_na_flag(struct attr *attr,
 237                 uint8_t *router_flag, bool *proxy)
 238 {
 239         struct ecommunity *ecom;
 240         int i;
 241         uint8_t val;
 242
 243         ecom = attr->ecommunity;
 244         if (!ecom || !ecom->size)
 245                 return;
 246
 247         /* If there is a evpn na extendd community set router_flag */
 248         for (i = 0; i < ecom->size; i++) {
 249                 uint8_t *pnt;
 250                 uint8_t type, sub_type;
 251
 252                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 253                 type = *pnt++;
 254                 sub_type = *pnt++;
 255
 256                 if (type == ECOMMUNITY_ENCODE_EVPN &&
 257                     sub_type == ECOMMUNITY_EVPN_SUBTYPE_ND) {
 258                         val = *pnt++;
 259
 260                         if (val & ECOMMUNITY_EVPN_SUBTYPE_ND_ROUTER_FLAG)
 261                                 *router_flag = 1;
 262
 263                         if (val & ECOMMUNITY_EVPN_SUBTYPE_PROXY_FLAG)
 264                                 *proxy = true;
 265
 266                         break;
 267                 }
 268         }
 269 }
 270
 271 /* dst prefix must be AF_INET or AF_INET6 prefix, to forge EVPN prefix */
 272 extern int bgp_build_evpn_prefix(int evpn_type, uint32_t eth_tag,
 273                                  struct prefix *dst)
 274 {
 275         struct evpn_addr *p_evpn_p;
 276         struct prefix p2;
 277         struct prefix *src = &p2;
 278
 279         if (!dst || dst->family == 0)
 280                 return -1;
 281         /* store initial prefix in src */
 282         prefix_copy(src, dst);
 283         memset(dst, 0, sizeof(struct prefix));
 284         p_evpn_p = &(dst->u.prefix_evpn);
 285         dst->family = AF_EVPN;
 286         p_evpn_p->route_type = evpn_type;
 287         if (evpn_type == BGP_EVPN_IP_PREFIX_ROUTE) {
 288                 p_evpn_p->prefix_addr.eth_tag = eth_tag;
 289                 p_evpn_p->prefix_addr.ip_prefix_length = p2.prefixlen;
 290                 if (src->family == AF_INET) {
 291                         SET_IPADDR_V4(&p_evpn_p->prefix_addr.ip);
 292                         memcpy(&p_evpn_p->prefix_addr.ip.ipaddr_v4,
 293                                &src->u.prefix4,
 294                                sizeof(struct in_addr));
 295                         dst->prefixlen = (uint16_t)PREFIX_LEN_ROUTE_TYPE_5_IPV4;
 296                 } else {
 297                         SET_IPADDR_V6(&p_evpn_p->prefix_addr.ip);
 298                         memcpy(&p_evpn_p->prefix_addr.ip.ipaddr_v6,
 299                                &src->u.prefix6,
 300                                sizeof(struct in6_addr));
 301                         dst->prefixlen = (uint16_t)PREFIX_LEN_ROUTE_TYPE_5_IPV6;
 302                 }
 303         } else
 304                 return -1;
 305         return 0;
 306 }
 307
 308 extern bool is_zero_gw_ip(const union gw_addr *gw_ip, const afi_t afi)
 309 {
 310         if (afi == AF_INET6 && IN6_IS_ADDR_UNSPECIFIED(&gw_ip->ipv6))
 311                 return true;
 312
 313         if (afi == AF_INET && gw_ip->ipv4.s_addr == INADDR_ANY)
 314                 return true;
 315
 316         return false;
 317 }