bgpd/bgp_attr_evpn.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* Ethernet-VPN Attribute handling file
   3  * Copyright (C) 2016 6WIND
   4  */
   5
   6 #include <zebra.h>
   7
   8 #include "command.h"
   9 #include "filter.h"
  10 #include "prefix.h"
  11 #include "log.h"
  12 #include "memory.h"
  13 #include "stream.h"
  14 #include "vxlan.h"
  15
  16 #include "bgpd/bgpd.h"
  17 #include "bgpd/bgp_attr.h"
  18 #include "bgpd/bgp_route.h"
  19 #include "bgpd/bgp_attr_evpn.h"
  20 #include "bgpd/bgp_ecommunity.h"
  21 #include "bgpd/bgp_evpn.h"
  22 #include "bgpd/bgp_evpn_private.h"
  23
  24 bool bgp_route_evpn_same(const struct bgp_route_evpn *e1,
  25                          const struct bgp_route_evpn *e2)
  26 {
  27         return (e1->type == e2->type &&
  28                 !memcmp(&(e1->eth_s_id), &(e2->eth_s_id), sizeof(esi_t)) &&
  29                 !ipaddr_cmp(&(e1->gw_ip), &(e2->gw_ip)));
  30 }
  31
  32 void bgp_add_routermac_ecom(struct attr *attr, struct ethaddr *routermac)
  33 {
  34         struct ecommunity_val routermac_ecom;
  35         struct ecommunity *ecomm = bgp_attr_get_ecommunity(attr);
  36
  37         memset(&routermac_ecom, 0, sizeof(routermac_ecom));
  38         routermac_ecom.val[0] = ECOMMUNITY_ENCODE_EVPN;
  39         routermac_ecom.val[1] = ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC;
  40         memcpy(&routermac_ecom.val[2], routermac->octet, ETH_ALEN);
  41         if (!ecomm) {
  42                 bgp_attr_set_ecommunity(attr, ecommunity_new());
  43                 ecomm = bgp_attr_get_ecommunity(attr);
  44         }
  45         ecommunity_add_val(ecomm, &routermac_ecom, false, false);
  46         ecommunity_str(ecomm);
  47 }
  48
  49 /* converts to an esi
  50  * returns 1 on success, 0 otherwise
  51  * format accepted: AA:BB:CC:DD:EE:FF:GG:HH:II:JJ
  52  * if id is null, check only is done
  53  */
  54 bool str2esi(const char *str, esi_t *id)
  55 {
  56         unsigned int a[ESI_BYTES];
  57         int i;
  58
  59         if (!str)
  60                 return false;
  61         if (sscanf(str, "%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x:%2x", a + 0, a + 1,
  62                    a + 2, a + 3, a + 4, a + 5, a + 6, a + 7, a + 8, a + 9)
  63             != ESI_BYTES) {
  64                 /* error in incoming str length */
  65                 return false;
  66         }
  67         /* valid mac address */
  68         if (!id)
  69                 return true;
  70         for (i = 0; i < ESI_BYTES; ++i)
  71                 id->val[i] = a[i] & 0xff;
  72         return true;
  73 }
  74
  75 char *ecom_mac2str(char *ecom_mac)
  76 {
  77         char *en;
  78
  79         en = ecom_mac;
  80         en += 2;
  81
  82         return prefix_mac2str((struct ethaddr *)en, NULL, 0);
  83 }
  84
  85 /* Fetch router-mac from extended community */
  86 bool bgp_attr_rmac(struct attr *attr, struct ethaddr *rmac)
  87 {
  88         uint32_t i = 0;
  89         struct ecommunity *ecom;
  90
  91         ecom = bgp_attr_get_ecommunity(attr);
  92         if (!ecom || !ecom->size)
  93                 return false;
  94
  95         /* If there is a router mac extended community, set RMAC in attr */
  96         for (i = 0; i < ecom->size; i++) {
  97                 uint8_t *pnt = NULL;
  98                 uint8_t type = 0;
  99                 uint8_t sub_type = 0;
 100
 101                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 102                 type = *pnt++;
 103                 sub_type = *pnt++;
 104
 105                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 106                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_ROUTERMAC))
 107                         continue;
 108
 109                 memcpy(rmac, pnt, ETH_ALEN);
 110                 return true;
 111         }
 112         return false;
 113 }
 114
 115 /*
 116  * return true if attr contains default gw extended community
 117  */
 118 uint8_t bgp_attr_default_gw(struct attr *attr)
 119 {
 120         struct ecommunity *ecom;
 121         uint32_t i;
 122
 123         ecom = bgp_attr_get_ecommunity(attr);
 124         if (!ecom || !ecom->size)
 125                 return 0;
 126
 127         /* If there is a default gw extendd community return true otherwise
 128          * return 0 */
 129         for (i = 0; i < ecom->size; i++) {
 130                 uint8_t *pnt;
 131                 uint8_t type, sub_type;
 132
 133                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 134                 type = *pnt++;
 135                 sub_type = *pnt++;
 136
 137                 if ((type == ECOMMUNITY_ENCODE_OPAQUE
 138                      && sub_type == ECOMMUNITY_EVPN_SUBTYPE_DEF_GW))
 139                         return 1;
 140         }
 141
 142         return 0;
 143 }
 144
 145 /*
 146  * Fetch and return the DF preference and algorithm from
 147  * DF election extended community, if present, else 0.
 148  */
 149 uint16_t bgp_attr_df_pref_from_ec(struct attr *attr, uint8_t *alg)
 150 {
 151         struct ecommunity *ecom;
 152         uint32_t i;
 153         uint16_t df_pref = 0;
 154
 155         *alg = EVPN_MH_DF_ALG_SERVICE_CARVING;
 156         ecom = bgp_attr_get_ecommunity(attr);
 157         if (!ecom || !ecom->size)
 158                 return 0;
 159
 160         for (i = 0; i < ecom->size; i++) {
 161                 uint8_t *pnt;
 162                 uint8_t type, sub_type;
 163
 164                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 165                 type = *pnt++;
 166                 sub_type = *pnt++;
 167                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 168                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_DF_ELECTION))
 169                         continue;
 170
 171                 *alg = (*pnt++) & ECOMMUNITY_EVPN_SUBTYPE_DF_ALG_BITS;
 172
 173                 pnt += 3;
 174                 pnt = ptr_get_be16(pnt, &df_pref);
 175                 (void)pnt; /* consume value */
 176                 break;
 177         }
 178
 179         return df_pref;
 180 }
 181
 182 /*
 183  * Fetch and return the sequence number from MAC Mobility extended
 184  * community, if present, else 0.
 185  */
 186 uint32_t bgp_attr_mac_mobility_seqnum(struct attr *attr, uint8_t *sticky)
 187 {
 188         struct ecommunity *ecom;
 189         uint32_t i;
 190         uint8_t flags = 0;
 191
 192         ecom = bgp_attr_get_ecommunity(attr);
 193         if (!ecom || !ecom->size)
 194                 return 0;
 195
 196         /* If there is a MAC Mobility extended community, return its
 197          * sequence number.
 198          * TODO: RFC is silent on handling of multiple MAC mobility extended
 199          * communities for the same route. We will bail out upon the first
 200          * one.
 201          */
 202         for (i = 0; i < ecom->size; i++) {
 203                 const uint8_t *pnt;
 204                 uint8_t type, sub_type;
 205                 uint32_t seq_num;
 206
 207                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 208                 type = *pnt++;
 209                 sub_type = *pnt++;
 210                 if (!(type == ECOMMUNITY_ENCODE_EVPN
 211                       && sub_type == ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY))
 212                         continue;
 213                 flags = *pnt++;
 214
 215                 if (flags & ECOMMUNITY_EVPN_SUBTYPE_MACMOBILITY_FLAG_STICKY)
 216                         *sticky = 1;
 217                 else
 218                         *sticky = 0;
 219
 220                 pnt++;
 221                 pnt = ptr_get_be32(pnt, &seq_num);
 222                 (void)pnt; /* consume value */
 223                 return seq_num;
 224         }
 225
 226         return 0;
 227 }
 228
 229 /*
 230  * return true if attr contains router flag extended community
 231  */
 232 void bgp_attr_evpn_na_flag(struct attr *attr,
 233                 uint8_t *router_flag, bool *proxy)
 234 {
 235         struct ecommunity *ecom;
 236         uint32_t i;
 237         uint8_t val;
 238
 239         ecom = bgp_attr_get_ecommunity(attr);
 240         if (!ecom || !ecom->size)
 241                 return;
 242
 243         /* If there is a evpn na extendd community set router_flag */
 244         for (i = 0; i < ecom->size; i++) {
 245                 uint8_t *pnt;
 246                 uint8_t type, sub_type;
 247
 248                 pnt = (ecom->val + (i * ECOMMUNITY_SIZE));
 249                 type = *pnt++;
 250                 sub_type = *pnt++;
 251
 252                 if (type == ECOMMUNITY_ENCODE_EVPN &&
 253                     sub_type == ECOMMUNITY_EVPN_SUBTYPE_ND) {
 254                         val = *pnt++;
 255
 256                         if (val & ECOMMUNITY_EVPN_SUBTYPE_ND_ROUTER_FLAG)
 257                                 *router_flag = 1;
 258
 259                         if (val & ECOMMUNITY_EVPN_SUBTYPE_PROXY_FLAG)
 260                                 *proxy = true;
 261
 262                         break;
 263                 }
 264         }
 265 }
 266
 267 /* dst prefix must be AF_INET or AF_INET6 prefix, to forge EVPN prefix */
 268 extern int bgp_build_evpn_prefix(int evpn_type, uint32_t eth_tag,
 269                                  struct prefix *dst)
 270 {
 271         struct evpn_addr *p_evpn_p;
 272         struct prefix p2;
 273         struct prefix *src = &p2;
 274
 275         if (!dst || dst->family == 0)
 276                 return -1;
 277         /* store initial prefix in src */
 278         prefix_copy(src, dst);
 279         memset(dst, 0, sizeof(struct prefix));
 280         p_evpn_p = &(dst->u.prefix_evpn);
 281         dst->family = AF_EVPN;
 282         p_evpn_p->route_type = evpn_type;
 283         if (evpn_type == BGP_EVPN_IP_PREFIX_ROUTE) {
 284                 p_evpn_p->prefix_addr.eth_tag = eth_tag;
 285                 p_evpn_p->prefix_addr.ip_prefix_length = p2.prefixlen;
 286                 if (src->family == AF_INET) {
 287                         SET_IPADDR_V4(&p_evpn_p->prefix_addr.ip);
 288                         memcpy(&p_evpn_p->prefix_addr.ip.ipaddr_v4,
 289                                &src->u.prefix4,
 290                                sizeof(struct in_addr));
 291                         dst->prefixlen = (uint16_t)PREFIX_LEN_ROUTE_TYPE_5_IPV4;
 292                 } else {
 293                         SET_IPADDR_V6(&p_evpn_p->prefix_addr.ip);
 294                         memcpy(&p_evpn_p->prefix_addr.ip.ipaddr_v6,
 295                                &src->u.prefix6,
 296                                sizeof(struct in6_addr));
 297                         dst->prefixlen = (uint16_t)PREFIX_LEN_ROUTE_TYPE_5_IPV6;
 298                 }
 299         } else
 300                 return -1;
 301         return 0;
 302 }