diff options
Diffstat (limited to '')
| -rw-r--r-- | zebra/label_manager.c | 489 |
1 files changed, 489 insertions, 0 deletions
diff --git a/zebra/label_manager.c b/zebra/label_manager.c new file mode 100644 index 0000000..2634a33 --- /dev/null +++ b/zebra/label_manager.c @@ -0,0 +1,489 @@ +/* + * Label Manager for FRR + * + * Copyright (C) 2017 by Bingen Eguzkitza, + * Volta Networks Inc. + * + * This file is part of FRRouting (FRR) + * + * FRR is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2, or (at your option) any + * later version. + * + * FRR is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License along + * with this program; see the file COPYING; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <zebra.h> +#include <stdio.h> +#include <string.h> +#include <sys/types.h> + +#include "lib/log.h" +#include "lib/memory.h" +#include "lib/mpls.h" +#include "lib/network.h" +#include "lib/stream.h" +#include "lib/zclient.h" +#include "lib/libfrr.h" + +//#include "zebra/zserv.h" +#include "zebra/zebra_router.h" +#include "zebra/label_manager.h" +#include "zebra/zebra_errors.h" +#include "zebra/zapi_msg.h" +#include "zebra/debug.h" + +#define CONNECTION_DELAY 5 + +struct label_manager lbl_mgr; + +DEFINE_MGROUP(LBL_MGR, "Label Manager"); +DEFINE_MTYPE_STATIC(LBL_MGR, LM_CHUNK, "Label Manager Chunk"); + +/* define hooks for the basic API, so that it can be specialized or served + * externally + */ + +DEFINE_HOOK(lm_client_connect, (struct zserv *client, vrf_id_t vrf_id), + (client, vrf_id)); +DEFINE_HOOK(lm_client_disconnect, (struct zserv *client), (client)); +DEFINE_HOOK(lm_get_chunk, + (struct label_manager_chunk * *lmc, struct zserv *client, + uint8_t keep, uint32_t size, uint32_t base, vrf_id_t vrf_id), + (lmc, client, keep, size, base, vrf_id)); +DEFINE_HOOK(lm_release_chunk, + (struct zserv *client, uint32_t start, uint32_t end), + (client, start, end)); +DEFINE_HOOK(lm_cbs_inited, (), ()); + +/* define wrappers to be called in zapi_msg.c (as hooks must be called in + * source file where they were defined) + */ +void lm_client_connect_call(struct zserv *client, vrf_id_t vrf_id) +{ + hook_call(lm_client_connect, client, vrf_id); +} +void lm_get_chunk_call(struct label_manager_chunk **lmc, struct zserv *client, + uint8_t keep, uint32_t size, uint32_t base, + vrf_id_t vrf_id) +{ + hook_call(lm_get_chunk, lmc, client, keep, size, base, vrf_id); +} +void lm_release_chunk_call(struct zserv *client, uint32_t start, uint32_t end) +{ + hook_call(lm_release_chunk, client, start, end); +} + +/* forward declarations of the static functions to be used for some hooks */ +static int label_manager_connect(struct zserv *client, vrf_id_t vrf_id); +static int label_manager_disconnect(struct zserv *client); +static int label_manager_get_chunk(struct label_manager_chunk **lmc, + struct zserv *client, uint8_t keep, + uint32_t size, uint32_t base, + vrf_id_t vrf_id); +static int label_manager_release_label_chunk(struct zserv *client, + uint32_t start, uint32_t end); + +void delete_label_chunk(void *val) +{ + XFREE(MTYPE_LM_CHUNK, val); +} + +/** + * Release label chunks from a client. + * + * Called on client disconnection or reconnection. It only releases chunks + * with empty keep value. + * + * @param proto Daemon protocol of client, to identify the owner + * @param instance Instance, to identify the owner + * @return Number of chunks released + */ +int release_daemon_label_chunks(struct zserv *client) +{ + struct listnode *node; + struct label_manager_chunk *lmc; + int count = 0; + int ret; + + if (IS_ZEBRA_DEBUG_PACKET) + zlog_debug("%s: Releasing chunks for client proto %s, instance %d, session %u", + __func__, zebra_route_string(client->proto), + client->instance, client->session_id); + + for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { + if (lmc->proto == client->proto && + lmc->instance == client->instance && + lmc->session_id == client->session_id && lmc->keep == 0) { + ret = release_label_chunk(lmc->proto, lmc->instance, + lmc->session_id, + lmc->start, lmc->end); + if (ret == 0) + count++; + } + } + + if (IS_ZEBRA_DEBUG_PACKET) + zlog_debug("%s: Released %d label chunks", __func__, count); + + return count; +} + +int lm_client_disconnect_cb(struct zserv *client) +{ + hook_call(lm_client_disconnect, client); + return 0; +} + +void lm_hooks_register(void) +{ + hook_register(lm_client_connect, label_manager_connect); + hook_register(lm_client_disconnect, label_manager_disconnect); + hook_register(lm_get_chunk, label_manager_get_chunk); + hook_register(lm_release_chunk, label_manager_release_label_chunk); +} +void lm_hooks_unregister(void) +{ + hook_unregister(lm_client_connect, label_manager_connect); + hook_unregister(lm_client_disconnect, label_manager_disconnect); + hook_unregister(lm_get_chunk, label_manager_get_chunk); + hook_unregister(lm_release_chunk, label_manager_release_label_chunk); +} + +/** + * Init label manager (or proxy to an external one) + */ +void label_manager_init(void) +{ + lbl_mgr.lc_list = list_new(); + lbl_mgr.lc_list->del = delete_label_chunk; + hook_register(zserv_client_close, lm_client_disconnect_cb); + + /* register default hooks for the label manager actions */ + lm_hooks_register(); + + /* notify any external module that we are done */ + hook_call(lm_cbs_inited); +} + +/* alloc and fill a label chunk */ +struct label_manager_chunk * +create_label_chunk(uint8_t proto, unsigned short instance, uint32_t session_id, + uint8_t keep, uint32_t start, uint32_t end) +{ + /* alloc chunk, fill it and return it */ + struct label_manager_chunk *lmc = + XCALLOC(MTYPE_LM_CHUNK, sizeof(struct label_manager_chunk)); + + lmc->start = start; + lmc->end = end; + lmc->proto = proto; + lmc->instance = instance; + lmc->session_id = session_id; + lmc->keep = keep; + + return lmc; +} + +/* attempt to get a specific label chunk */ +static struct label_manager_chunk * +assign_specific_label_chunk(uint8_t proto, unsigned short instance, + uint32_t session_id, uint8_t keep, uint32_t size, + uint32_t base) +{ + struct label_manager_chunk *lmc; + struct listnode *node, *next = NULL; + struct listnode *first_node = NULL; + struct listnode *last_node = NULL; + struct listnode *insert_node = NULL; + + /* precompute last label from base and size */ + uint32_t end = base + size - 1; + + /* sanities */ + if ((base < MPLS_LABEL_UNRESERVED_MIN) + || (end > MPLS_LABEL_UNRESERVED_MAX)) { + zlog_err("Invalid LM request arguments: base: %u, size: %u", + base, size); + return NULL; + } + + /* Scan the existing chunks to see if the requested range of labels + * falls inside any of such chunks */ + for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { + + /* skip chunks for labels < base */ + if (base > lmc->end) + continue; + + /* requested range is not covered by any existing, free chunk. + * Therefore, need to insert a chunk */ + if ((end < lmc->start) && !first_node) { + insert_node = node; + break; + } + + if (!first_node) + first_node = node; + + /* if chunk is used, cannot honor request */ + if (lmc->proto != NO_PROTO) + return NULL; + + if (end <= lmc->end) { + last_node = node; + break; + } + } + + /* insert chunk between existing chunks */ + if (insert_node) { + lmc = create_label_chunk(proto, instance, session_id, keep, + base, end); + listnode_add_before(lbl_mgr.lc_list, insert_node, lmc); + return lmc; + } + + if (first_node) { + /* get node past the last one, if there */ + if (last_node) + last_node = listnextnode(last_node); + + /* delete node coming after the above chunk whose labels are + * included in the previous one */ + for (node = first_node; node && (node != last_node); + node = next) { + struct label_manager_chunk *death; + + next = listnextnode(node); + death = listgetdata(node); + list_delete_node(lbl_mgr.lc_list, node); + delete_label_chunk(death); + } + + lmc = create_label_chunk(proto, instance, session_id, keep, + base, end); + if (last_node) + listnode_add_before(lbl_mgr.lc_list, last_node, lmc); + else + listnode_add(lbl_mgr.lc_list, lmc); + + return lmc; + } else { + /* create a new chunk past all the existing ones and link at + * tail */ + lmc = create_label_chunk(proto, instance, session_id, keep, + base, end); + listnode_add(lbl_mgr.lc_list, lmc); + return lmc; + } +} + +/** + * Core function, assigns label chunks + * + * It first searches through the list to check if there's one available + * (previously released). Otherwise it creates and assigns a new one + * + * @param proto Daemon protocol of client, to identify the owner + * @param instance Instance, to identify the owner + * @param keep If set, avoid garbage collection + * @param size Size of the label chunk + * @param base Desired starting label of the chunk; if MPLS_LABEL_BASE_ANY it does not apply + * @return Pointer to the assigned label chunk, or NULL if the request could not be satisfied + */ +struct label_manager_chunk * +assign_label_chunk(uint8_t proto, unsigned short instance, uint32_t session_id, + uint8_t keep, uint32_t size, uint32_t base) +{ + struct label_manager_chunk *lmc; + struct listnode *node; + uint32_t prev_end = MPLS_LABEL_UNRESERVED_MIN; + + /* handle chunks request with a specific base label */ + if (base != MPLS_LABEL_BASE_ANY) + return assign_specific_label_chunk(proto, instance, session_id, + keep, size, base); + + /* appease scan-build, who gets confused by the use of macros */ + assert(lbl_mgr.lc_list); + + /* first check if there's one available */ + for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { + if (lmc->proto == NO_PROTO + && lmc->end - lmc->start + 1 == size) { + lmc->proto = proto; + lmc->instance = instance; + lmc->session_id = session_id; + lmc->keep = keep; + return lmc; + } + /* check if we hadve a "hole" behind us that we can squeeze into + */ + if ((lmc->start > prev_end) && (lmc->start - prev_end > size)) { + lmc = create_label_chunk(proto, instance, session_id, + keep, prev_end + 1, + prev_end + size); + listnode_add_before(lbl_mgr.lc_list, node, lmc); + return lmc; + } + prev_end = lmc->end; + } + /* otherwise create a new one */ + uint32_t start_free; + + if (list_isempty(lbl_mgr.lc_list)) + start_free = MPLS_LABEL_UNRESERVED_MIN; + else + start_free = ((struct label_manager_chunk *)listgetdata( + listtail(lbl_mgr.lc_list))) + ->end + + 1; + + if (start_free > MPLS_LABEL_UNRESERVED_MAX - size + 1) { + flog_err(EC_ZEBRA_LM_EXHAUSTED_LABELS, + "Reached max labels. Start: %u, size: %u", start_free, + size); + return NULL; + } + + /* create chunk and link at tail */ + lmc = create_label_chunk(proto, instance, session_id, keep, start_free, + start_free + size - 1); + listnode_add(lbl_mgr.lc_list, lmc); + return lmc; +} + +/** + * Release label chunks from a client. + * + * Called on client disconnection or reconnection. It only releases chunks + * with empty keep value. + * + * @param client Client zapi session + * @param start First label of the chunk + * @param end Last label of the chunk + * @return 0 on success + */ +static int label_manager_release_label_chunk(struct zserv *client, + uint32_t start, uint32_t end) +{ + return release_label_chunk(client->proto, client->instance, + client->session_id, start, end); +} + +/** + * Core function, release no longer used label chunks + * + * @param proto Daemon protocol of client, to identify the owner + * @param instance Instance, to identify the owner + * @param session_id Zclient session ID, to identify the zclient session + * @param start First label of the chunk + * @param end Last label of the chunk + * @return 0 on success, -1 otherwise + */ +int release_label_chunk(uint8_t proto, unsigned short instance, + uint32_t session_id, uint32_t start, uint32_t end) +{ + struct listnode *node; + struct label_manager_chunk *lmc; + int ret = -1; + + /* check that size matches */ + if (IS_ZEBRA_DEBUG_PACKET) + zlog_debug("Releasing label chunk: %u - %u", start, end); + /* find chunk and disown */ + for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { + if (lmc->start != start) + continue; + if (lmc->end != end) + continue; + if (lmc->proto != proto || lmc->instance != instance || + lmc->session_id != session_id) { + flog_err(EC_ZEBRA_LM_DAEMON_MISMATCH, + "%s: Daemon mismatch!!", __func__); + continue; + } + lmc->proto = NO_PROTO; + lmc->instance = 0; + lmc->session_id = 0; + lmc->keep = 0; + ret = 0; + break; + } + if (ret != 0) + flog_err(EC_ZEBRA_LM_UNRELEASED_CHUNK, + "%s: Label chunk not released!!", __func__); + + return ret; +} + +/* default functions to be called on hooks */ +static int label_manager_connect(struct zserv *client, vrf_id_t vrf_id) +{ + /* + * Release previous labels of same protocol and instance. + * This is done in case it restarted from an unexpected shutdown. + */ + release_daemon_label_chunks(client); + return zsend_label_manager_connect_response(client, vrf_id, 0); +} +static int label_manager_disconnect(struct zserv *client) +{ + release_daemon_label_chunks(client); + return 0; +} +static int label_manager_get_chunk(struct label_manager_chunk **lmc, + struct zserv *client, uint8_t keep, + uint32_t size, uint32_t base, + vrf_id_t vrf_id) +{ + *lmc = assign_label_chunk(client->proto, client->instance, + client->session_id, keep, size, base); + return lm_get_chunk_response(*lmc, client, vrf_id); +} + +/* Respond to a connect request */ +int lm_client_connect_response(uint8_t proto, uint16_t instance, + uint32_t session_id, vrf_id_t vrf_id, + uint8_t result) +{ + struct zserv *client = zserv_find_client_session(proto, instance, + session_id); + if (!client) { + zlog_err("%s: could not find client for daemon %s instance %u session %u", + __func__, zebra_route_string(proto), instance, + session_id); + return 1; + } + return zsend_label_manager_connect_response(client, vrf_id, result); +} + +/* Respond to a get_chunk request */ +int lm_get_chunk_response(struct label_manager_chunk *lmc, struct zserv *client, + vrf_id_t vrf_id) +{ + if (!lmc) + flog_err(EC_ZEBRA_LM_CANNOT_ASSIGN_CHUNK, + "Unable to assign Label Chunk to %s instance %u", + zebra_route_string(client->proto), client->instance); + else if (IS_ZEBRA_DEBUG_PACKET) + zlog_debug("Assigned Label Chunk %u - %u to %s instance %u", + lmc->start, lmc->end, + zebra_route_string(client->proto), client->instance); + + return zsend_assign_label_chunk_response(client, vrf_id, lmc); +} + +void label_manager_close(void) +{ + list_delete(&lbl_mgr.lc_list); +} |