zebra/zebra_srv6.c

   1 /*
   2  * Zebra SRv6 definitions
   3  * Copyright (C) 2020  Hiroki Shirokura, LINE Corporation
   4  * Copyright (C) 2020  Masakazu Asama
   5  *
   6  * This program 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 Free
   8  * Software Foundation; either version 2 of the License, or (at your option)
   9  * any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  14  * 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 "network.h"
  24 #include "prefix.h"
  25 #include "stream.h"
  26 #include "srv6.h"
  27 #include "zebra/debug.h"
  28 #include "zebra/zapi_msg.h"
  29 #include "zebra/zserv.h"
  30 #include "zebra/zebra_router.h"
  31 #include "zebra/zebra_srv6.h"
  32 #include "zebra/zebra_errors.h"
  33 #include <stdio.h>
  34 #include <string.h>
  35 #include <stdlib.h>
  36 #include <arpa/inet.h>
  37 #include <netinet/in.h>
  38
  39 #include <stdio.h>
  40 #include <string.h>
  41 #include <stdlib.h>
  42 #include <arpa/inet.h>
  43 #include <netinet/in.h>
  44
  45
  46 DEFINE_MGROUP(SRV6_MGR, "SRv6 Manager");
  47 DEFINE_MTYPE_STATIC(SRV6_MGR, SRV6M_CHUNK, "SRv6 Manager Chunk");
  48
  49 /* define hooks for the basic API, so that it can be specialized or served
  50  * externally
  51  */
  52
  53 DEFINE_HOOK(srv6_manager_client_connect,
  54             (struct zserv *client, vrf_id_t vrf_id),
  55             (client, vrf_id));
  56 DEFINE_HOOK(srv6_manager_client_disconnect,
  57             (struct zserv *client), (client));
  58 DEFINE_HOOK(srv6_manager_get_chunk,
  59             (struct srv6_locator **loc,
  60              struct zserv *client,
  61              const char *locator_name,
  62              vrf_id_t vrf_id),
  63             (loc, client, locator_name, vrf_id));
  64 DEFINE_HOOK(srv6_manager_release_chunk,
  65             (struct zserv *client,
  66              const char *locator_name,
  67              vrf_id_t vrf_id),
  68             (client, locator_name, vrf_id));
  69
  70 /* define wrappers to be called in zapi_msg.c (as hooks must be called in
  71  * source file where they were defined)
  72  */
  73
  74 void srv6_manager_client_connect_call(struct zserv *client, vrf_id_t vrf_id)
  75 {
  76         hook_call(srv6_manager_client_connect, client, vrf_id);
  77 }
  78
  79 void srv6_manager_get_locator_chunk_call(struct srv6_locator **loc,
  80                                          struct zserv *client,
  81                                          const char *locator_name,
  82                                          vrf_id_t vrf_id)
  83 {
  84         hook_call(srv6_manager_get_chunk, loc, client, locator_name, vrf_id);
  85 }
  86
  87 void srv6_manager_release_locator_chunk_call(struct zserv *client,
  88                                              const char *locator_name,
  89                                              vrf_id_t vrf_id)
  90 {
  91         hook_call(srv6_manager_release_chunk, client, locator_name, vrf_id);
  92 }
  93
  94 int srv6_manager_client_disconnect_cb(struct zserv *client)
  95 {
  96         hook_call(srv6_manager_client_disconnect, client);
  97         return 0;
  98 }
  99
 100 static int zebra_srv6_cleanup(struct zserv *client)
 101 {
 102         return 0;
 103 }
 104
 105 void zebra_srv6_locator_add(struct srv6_locator *locator)
 106 {
 107         struct zebra_srv6 *srv6 = zebra_srv6_get_default();
 108         struct srv6_locator *tmp;
 109         struct listnode *node;
 110         struct zserv *client;
 111
 112         tmp = zebra_srv6_locator_lookup(locator->name);
 113         if (!tmp)
 114                 listnode_add(srv6->locators, locator);
 115
 116         /*
 117          * Notify new locator info to zclients.
 118          *
 119          * The srv6 locators and their prefixes are managed by zserv(zebra).
 120          * And an actual configuration the srv6 sid in the srv6 locator is done
 121          * by zclient(bgpd, isisd, etc). The configuration of each locator
 122          * allocation and specify it by zserv and zclient should be
 123          * asynchronous. For that, zclient should be received the event via
 124          * ZAPI when a srv6 locator is added on zebra.
 125          * Basically, in SRv6, adding/removing SRv6 locators is performed less
 126          * frequently than adding rib entries, so a broad to all zclients will
 127          * not degrade the overall performance of FRRouting.
 128          */
 129         for (ALL_LIST_ELEMENTS_RO(zrouter.client_list, node, client))
 130                 zsend_zebra_srv6_locator_add(client, locator);
 131 }
 132
 133 void zebra_srv6_locator_delete(struct srv6_locator *locator)
 134 {
 135         struct listnode *n;
 136         struct srv6_locator_chunk *c;
 137         struct zebra_srv6 *srv6 = zebra_srv6_get_default();
 138         struct zserv *client;
 139
 140         /*
 141          * Notify deleted locator info to zclients if needed.
 142          *
 143          * zclient(bgpd,isisd,etc) allocates a sid from srv6 locator chunk and
 144          * uses it for its own purpose. For example, in the case of BGP L3VPN,
 145          * the SID assigned to vpn unicast rib will be given.
 146          * And when the locator is deleted by zserv(zebra), those SIDs need to
 147          * be withdrawn. The zclient must initiate the withdrawal of the SIDs
 148          * by ZEBRA_SRV6_LOCATOR_DELETE, and this notification is sent to the
 149          * owner of each chunk.
 150          */
 151         for (ALL_LIST_ELEMENTS_RO((struct list *)locator->chunks, n, c)) {
 152                 if (c->proto == ZEBRA_ROUTE_SYSTEM)
 153                         continue;
 154                 client = zserv_find_client(c->proto, c->instance);
 155                 if (!client) {
 156                         zlog_warn(
 157                                 "%s: Not found zclient(proto=%u, instance=%u).",
 158                                 __func__, c->proto, c->instance);
 159                         continue;
 160                 }
 161                 zsend_zebra_srv6_locator_delete(client, locator);
 162         }
 163
 164         listnode_delete(srv6->locators, locator);
 165         srv6_locator_free(locator);
 166 }
 167
 168 struct srv6_locator *zebra_srv6_locator_lookup(const char *name)
 169 {
 170         struct zebra_srv6 *srv6 = zebra_srv6_get_default();
 171         struct srv6_locator *locator;
 172         struct listnode *node;
 173
 174         for (ALL_LIST_ELEMENTS_RO(srv6->locators, node, locator))
 175                 if (!strncmp(name, locator->name, SRV6_LOCNAME_SIZE))
 176                         return locator;
 177         return NULL;
 178 }
 179
 180 struct zebra_srv6 *zebra_srv6_get_default(void)
 181 {
 182         static struct zebra_srv6 srv6;
 183         static bool first_execution = true;
 184
 185         if (first_execution) {
 186                 first_execution = false;
 187                 srv6.locators = list_new();
 188         }
 189         return &srv6;
 190 }
 191
 192 /**
 193  * Core function, assigns srv6-locator chunks
 194  *
 195  * It first searches through the list to check if there's one available
 196  * (previously released). Otherwise it creates and assigns a new one
 197  *
 198  * @param proto Daemon protocol of client, to identify the owner
 199  * @param instance Instance, to identify the owner
 200  * @param session_id SessionID of client
 201  * @param name Name of SRv6-locator
 202  * @return Pointer to the assigned srv6-locator chunk,
 203  *         or NULL if the request could not be satisfied
 204  */
 205 static struct srv6_locator *
 206 assign_srv6_locator_chunk(uint8_t proto,
 207                           uint16_t instance,
 208                           uint32_t session_id,
 209                           const char *locator_name)
 210 {
 211         bool chunk_found = false;
 212         struct listnode *node = NULL;
 213         struct srv6_locator *loc = NULL;
 214         struct srv6_locator_chunk *chunk = NULL;
 215
 216         loc = zebra_srv6_locator_lookup(locator_name);
 217         if (!loc) {
 218                 zlog_info("%s: locator %s was not found",
 219                           __func__, locator_name);
 220                 return NULL;
 221         }
 222
 223         for (ALL_LIST_ELEMENTS_RO((struct list *)loc->chunks, node, chunk)) {
 224                 if (chunk->proto != NO_PROTO && chunk->proto != proto)
 225                         continue;
 226                 chunk_found = true;
 227                 break;
 228         }
 229
 230         if (!chunk_found) {
 231                 zlog_info("%s: locator is already owned", __func__);
 232                 return NULL;
 233         }
 234
 235         chunk->proto = proto;
 236         chunk->instance = instance;
 237         chunk->session_id = session_id;
 238         return loc;
 239 }
 240
 241 static int zebra_srv6_manager_get_locator_chunk(struct srv6_locator **loc,
 242                                                 struct zserv *client,
 243                                                 const char *locator_name,
 244                                                 vrf_id_t vrf_id)
 245 {
 246         int ret = 0;
 247
 248         *loc = assign_srv6_locator_chunk(client->proto, client->instance,
 249                                          client->session_id, locator_name);
 250
 251         if (!*loc)
 252                 zlog_err("Unable to assign locator chunk to %s instance %u",
 253                          zebra_route_string(client->proto), client->instance);
 254         else if (IS_ZEBRA_DEBUG_PACKET)
 255                 zlog_info("Assigned locator chunk %s to %s instance %u",
 256                           (*loc)->name, zebra_route_string(client->proto),
 257                           client->instance);
 258
 259         if (*loc && (*loc)->status_up)
 260                 ret = zsend_srv6_manager_get_locator_chunk_response(client,
 261                                                                     vrf_id,
 262                                                                     *loc);
 263         return ret;
 264 }
 265
 266 /**
 267  * Core function, release no longer used srv6-locator chunks
 268  *
 269  * @param proto Daemon protocol of client, to identify the owner
 270  * @param instance Instance, to identify the owner
 271  * @param session_id Zclient session ID, to identify the zclient session
 272  * @param locator_name SRv6-locator name, to identify the actual locator
 273  * @return 0 on success, -1 otherwise
 274  */
 275 static int release_srv6_locator_chunk(uint8_t proto, uint16_t instance,
 276                                       uint32_t session_id,
 277                                       const char *locator_name)
 278 {
 279         int ret = -1;
 280         struct listnode *node;
 281         struct srv6_locator_chunk *chunk;
 282         struct srv6_locator *loc = NULL;
 283
 284         loc = zebra_srv6_locator_lookup(locator_name);
 285         if (!loc)
 286                 return -1;
 287
 288         if (IS_ZEBRA_DEBUG_PACKET)
 289                 zlog_debug("%s: Releasing srv6-locator on %s", __func__,
 290                            locator_name);
 291
 292         for (ALL_LIST_ELEMENTS_RO((struct list *)loc->chunks, node, chunk)) {
 293                 if (chunk->proto != proto ||
 294                     chunk->instance != instance ||
 295                     chunk->session_id != session_id)
 296                         continue;
 297                 chunk->proto = NO_PROTO;
 298                 chunk->instance = 0;
 299                 chunk->session_id = 0;
 300                 chunk->keep = 0;
 301                 ret = 0;
 302                 break;
 303         }
 304
 305         if (ret != 0)
 306                 flog_err(EC_ZEBRA_SRV6M_UNRELEASED_LOCATOR_CHUNK,
 307                          "%s: SRv6 locator chunk not released", __func__);
 308
 309         return ret;
 310 }
 311
 312 static int zebra_srv6_manager_release_locator_chunk(struct zserv *client,
 313                                                     const char *locator_name,
 314                                                     vrf_id_t vrf_id)
 315 {
 316         if (vrf_id != VRF_DEFAULT) {
 317                 zlog_err("SRv6 locator doesn't support vrf");
 318                 return -1;
 319         }
 320
 321         return release_srv6_locator_chunk(client->proto, client->instance,
 322                                           client->session_id, locator_name);
 323 }
 324
 325 /**
 326  * Release srv6-locator chunks from a client.
 327  *
 328  * Called on client disconnection or reconnection. It only releases chunks
 329  * with empty keep value.
 330  *
 331  * @param proto Daemon protocol of client, to identify the owner
 332  * @param instance Instance, to identify the owner
 333  * @return Number of chunks released
 334  */
 335 int release_daemon_srv6_locator_chunks(struct zserv *client)
 336 {
 337         int ret;
 338         int count = 0;
 339         struct zebra_srv6 *srv6 = zebra_srv6_get_default();
 340         struct listnode *loc_node;
 341         struct listnode *chunk_node;
 342         struct srv6_locator *loc;
 343         struct srv6_locator_chunk *chunk;
 344
 345         if (IS_ZEBRA_DEBUG_PACKET)
 346                 zlog_debug("%s: Releasing chunks for client proto %s, instance %d, session %u",
 347                            __func__, zebra_route_string(client->proto),
 348                            client->instance, client->session_id);
 349
 350         for (ALL_LIST_ELEMENTS_RO(srv6->locators, loc_node, loc)) {
 351                 for (ALL_LIST_ELEMENTS_RO(loc->chunks, chunk_node, chunk)) {
 352                         if (chunk->proto == client->proto &&
 353                             chunk->instance == client->instance &&
 354                             chunk->session_id == client->session_id &&
 355                             chunk->keep == 0) {
 356                                 ret = release_srv6_locator_chunk(
 357                                                 chunk->proto, chunk->instance,
 358                                                 chunk->session_id, loc->name);
 359                                 if (ret == 0)
 360                                         count++;
 361                         }
 362                 }
 363         }
 364
 365         if (IS_ZEBRA_DEBUG_PACKET)
 366                 zlog_debug("%s: Released %d srv6-locator chunks",
 367                            __func__, count);
 368
 369         return count;
 370 }
 371
 372 void zebra_srv6_init(void)
 373 {
 374         hook_register(zserv_client_close, zebra_srv6_cleanup);
 375         hook_register(srv6_manager_get_chunk,
 376                       zebra_srv6_manager_get_locator_chunk);
 377         hook_register(srv6_manager_release_chunk,
 378                       zebra_srv6_manager_release_locator_chunk);
 379 }
 380
 381 bool zebra_srv6_is_enable(void)
 382 {
 383         struct zebra_srv6 *srv6 = zebra_srv6_get_default();
 384
 385         return listcount(srv6->locators);
 386 }