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For SRGB, we need to support chunk requests starting at a specific point in the label space, rather than just asking for any sufficiently large chunk. To this purpose, we extend the label manager api to request a chunk with a base value; if the base is set to 0, the label manager will behave as it currently does, i.e. fetching the first free chunk big enough to satisfy the request. update all the existing calls to get chunks from the label manager so that they use MPLS_LABEL_BASE_ANY as the base for the requested chunk Signed-off-by: Emanuele Di Pascale <emanuele@voltanet.io>
616 lines
16 KiB
C
616 lines
16 KiB
C
/*
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* Label Manager for FRR
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*
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* Copyright (C) 2017 by Bingen Eguzkitza,
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* Volta Networks Inc.
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*
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* This file is part of FreeRangeRouting (FRR)
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*
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* FRR is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by the
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* Free Software Foundation; either version 2, or (at your option) any
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* later version.
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*
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* FRR is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License along
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* with this program; see the file COPYING; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <zebra.h>
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#include <stdio.h>
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#include <string.h>
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#include <sys/types.h>
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#include "lib/log.h"
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#include "lib/memory.h"
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#include "lib/mpls.h"
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#include "lib/network.h"
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#include "lib/stream.h"
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#include "lib/zclient.h"
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#include "lib/libfrr.h"
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//#include "zebra/zserv.h"
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#include "zebra/zebra_router.h"
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#include "zebra/label_manager.h"
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#include "zebra/zebra_errors.h"
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#define CONNECTION_DELAY 5
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struct label_manager lbl_mgr;
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extern struct zebra_privs_t zserv_privs;
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DEFINE_MGROUP(LBL_MGR, "Label Manager");
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DEFINE_MTYPE_STATIC(LBL_MGR, LM_CHUNK, "Label Manager Chunk");
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/* In case this zebra daemon is not acting as label manager,
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* it will be a proxy to relay messages to external label manager
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* This zclient thus is to connect to it
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*/
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static struct stream *obuf;
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static struct zclient *zclient;
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bool lm_is_external;
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static void delete_label_chunk(void *val)
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{
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XFREE(MTYPE_LM_CHUNK, val);
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}
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static int relay_response_back(void)
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{
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int ret = 0;
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struct stream *src, *dst;
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uint16_t size = 0;
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uint8_t marker;
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uint8_t version;
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vrf_id_t vrf_id;
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uint16_t resp_cmd;
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uint8_t proto;
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const char *proto_str;
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unsigned short instance;
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struct zserv *zserv;
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/* sanity */
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if (!zclient || zclient->sock < 0)
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return -1;
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/* input buffer with msg from label manager */
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src = zclient->ibuf;
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stream_reset(src);
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/* parse header */
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ret = zclient_read_header(src, zclient->sock, &size, &marker, &version,
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&vrf_id, &resp_cmd);
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if (ret < 0) {
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if (errno != EAGAIN)
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flog_err(EC_ZEBRA_LM_RESPONSE,
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"Error reading Label Manager response: %s",
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strerror(errno));
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return -1;
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}
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/* do not relay a msg that has nothing to do with LM */
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switch (resp_cmd) {
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case ZEBRA_LABEL_MANAGER_CONNECT:
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case ZEBRA_LABEL_MANAGER_CONNECT_ASYNC: /* should not be seen */
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case ZEBRA_GET_LABEL_CHUNK:
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case ZEBRA_RELEASE_LABEL_CHUNK:
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break;
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default:
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zlog_debug("Not relaying '%s' response (size %d) from LM",
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zserv_command_string(resp_cmd), size);
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return -1;
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}
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zlog_debug("Received '%s' response (size %d) from LM",
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zserv_command_string(resp_cmd), size);
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if (size == 0)
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return -1;
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/* Get the 'proto' field of the message */
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proto = stream_getc(src);
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/* Get the 'instance' field of the message */
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instance = stream_getw(src);
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proto_str = zebra_route_string(proto);
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/* lookup the client to relay the msg to */
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zserv = zserv_find_client(proto, instance);
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if (!zserv) {
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flog_err(
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EC_ZEBRA_LM_NO_SUCH_CLIENT,
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"Error relaying LM response: can't find client %s, instance %u",
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proto_str, instance);
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return -1;
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}
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zlog_debug("Found client to relay LM response to client %s instance %u",
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proto_str, instance);
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/* copy msg into output buffer */
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dst = obuf;
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stream_copy(dst, src);
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/* send response back */
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ret = writen(zserv->sock, dst->data, stream_get_endp(dst));
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if (ret <= 0) {
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flog_err(EC_ZEBRA_LM_RELAY_FAILED,
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"Error relaying LM response to %s instance %u: %s",
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proto_str, instance, strerror(errno));
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return -1;
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}
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zlog_debug("Relayed LM response (%d bytes) to %s instance %u", ret,
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proto_str, instance);
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return 0;
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}
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static int lm_zclient_read(struct thread *t)
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{
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int ret;
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zclient->t_read = NULL;
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/* read response and send it back */
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ret = relay_response_back();
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/* re-arm read */
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thread_add_read(zclient->master, lm_zclient_read, NULL,
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zclient->sock, &zclient->t_read);
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return ret;
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}
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static int reply_error(int cmd, struct zserv *zserv, vrf_id_t vrf_id)
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{
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int ret;
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struct stream *s;
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s = stream_new(ZEBRA_MAX_PACKET_SIZ);
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zclient_create_header(s, cmd, vrf_id);
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/* proto */
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stream_putc(s, zserv->proto);
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/* instance */
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stream_putw(s, zserv->instance);
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/* result */
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stream_putc(s, 1);
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/* Write packet size. */
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stream_putw_at(s, 0, stream_get_endp(s));
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ret = writen(zserv->sock, s->data, stream_get_endp(s));
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stream_free(s);
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return ret;
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}
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/**
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* Receive a request to get or release a label chunk and forward it to external
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* label manager.
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*
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* It's called from zserv in case it's not an actual label manager, but just a
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* proxy.
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*
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* @param cmd Type of request (connect, get or release)
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* @param zserv
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* @return 0 on success, -1 otherwise
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*/
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int zread_relay_label_manager_request(int cmd, struct zserv *zserv,
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struct stream *msg, vrf_id_t vrf_id)
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{
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struct stream *dst;
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int ret = 0;
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uint8_t proto;
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const char *proto_str;
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unsigned short instance;
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if (zclient->sock < 0) {
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flog_err(EC_ZEBRA_LM_NO_SOCKET,
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"Unable to relay LM request: no socket");
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reply_error(cmd, zserv, vrf_id);
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return -1;
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}
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/* peek msg to get proto and instance id. This zebra, which acts as
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* a proxy needs to have such values for each client in order to
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* relay responses back to it.
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*/
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/* Get the 'proto' field of incoming msg */
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proto = stream_getc(msg);
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/* Get the 'instance' field of incoming msg */
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instance = stream_getw(msg);
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/* stringify proto */
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proto_str = zebra_route_string(proto);
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/* check & set client proto if unset */
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if (zserv->proto && zserv->proto != proto) {
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flog_warn(EC_ZEBRAING_LM_PROTO_MISMATCH,
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"Client proto(%u) != msg proto(%u)", zserv->proto,
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proto);
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return -1;
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}
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/* check & set client instance if unset */
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if (zserv->instance && zserv->instance != instance) {
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flog_err(EC_ZEBRA_LM_BAD_INSTANCE,
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"Client instance(%u) != msg instance(%u)",
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zserv->instance, instance);
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return -1;
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}
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/* recall proto and instance */
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zserv->instance = instance;
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zserv->proto = proto;
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/* in case there's any incoming message enqueued, read and forward it */
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if (zserv->is_synchronous)
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while (ret == 0)
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ret = relay_response_back();
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/* get the msg buffer used toward the 'master' Label Manager */
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dst = zclient->obuf;
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/* copy the message */
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stream_copy(dst, msg);
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/* Send request to external label manager */
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ret = writen(zclient->sock, dst->data, stream_get_endp(dst));
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if (ret <= 0) {
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flog_err(EC_ZEBRA_LM_RELAY_FAILED,
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"Error relaying LM request from %s instance %u: %s",
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proto_str, instance, strerror(errno));
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reply_error(cmd, zserv, vrf_id);
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return -1;
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}
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zlog_debug("Relayed LM request (%d bytes) from %s instance %u", ret,
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proto_str, instance);
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/* Release label chunk has no response */
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if (cmd == ZEBRA_RELEASE_LABEL_CHUNK)
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return 0;
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/* make sure we listen to the response */
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if (!zclient->t_read)
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thread_add_read(zclient->master, lm_zclient_read, NULL,
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zclient->sock, &zclient->t_read);
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return 0;
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}
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static int lm_zclient_connect(struct thread *t)
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{
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zclient->t_connect = NULL;
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if (zclient->sock >= 0)
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return 0;
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if (zclient_socket_connect(zclient) < 0) {
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flog_err(EC_ZEBRA_LM_CLIENT_CONNECTION_FAILED,
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"Error connecting synchronous zclient!");
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thread_add_timer(zrouter.master, lm_zclient_connect, zclient,
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CONNECTION_DELAY, &zclient->t_connect);
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return -1;
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}
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/* make socket non-blocking */
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(void)set_nonblocking(zclient->sock);
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return 0;
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}
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/**
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* Function to initialize zclient in case this is not an actual
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* label manager, but just a proxy to an external one.
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*
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* @param lm_zserv_path Path to zserv socket of external label manager
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*/
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static void lm_zclient_init(char *lm_zserv_path)
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{
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if (lm_zserv_path)
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frr_zclient_addr(&zclient_addr, &zclient_addr_len,
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lm_zserv_path);
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/* Set default values. */
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zclient = zclient_new(zrouter.master, &zclient_options_default);
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zclient->privs = &zserv_privs;
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zclient->sock = -1;
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zclient->t_connect = NULL;
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lm_zclient_connect(NULL);
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}
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/**
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* Release label chunks from a client.
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*
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* Called on client disconnection or reconnection. It only releases chunks
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* with empty keep value.
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*
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* @param proto Daemon protocol of client, to identify the owner
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* @param instance Instance, to identify the owner
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* @return Number of chunks released
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*/
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int release_daemon_label_chunks(struct zserv *client)
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{
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uint8_t proto = client->proto;
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uint16_t instance = client->instance;
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struct listnode *node;
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struct label_manager_chunk *lmc;
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int count = 0;
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int ret;
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for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) {
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if (lmc->proto == proto && lmc->instance == instance
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&& lmc->keep == 0) {
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ret = release_label_chunk(lmc->proto, lmc->instance,
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lmc->start, lmc->end);
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if (ret == 0)
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count++;
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}
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}
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zlog_debug("%s: Released %d label chunks", __func__, count);
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return count;
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}
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/**
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* Init label manager (or proxy to an external one)
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*/
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void label_manager_init(char *lm_zserv_path)
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{
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/* this is an actual label manager */
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if (!lm_zserv_path) {
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zlog_debug("Initializing internal label manager");
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lm_is_external = false;
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lbl_mgr.lc_list = list_new();
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lbl_mgr.lc_list->del = delete_label_chunk;
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} else { /* it's acting just as a proxy */
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zlog_debug("Initializing external label manager at %s",
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lm_zserv_path);
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lm_is_external = true;
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lm_zclient_init(lm_zserv_path);
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}
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obuf = stream_new(ZEBRA_MAX_PACKET_SIZ);
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hook_register(zserv_client_close, release_daemon_label_chunks);
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}
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/* alloc and fill a label chunk */
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static struct label_manager_chunk *
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create_label_chunk(uint8_t proto, unsigned short instance, uint8_t keep,
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uint32_t start, uint32_t end)
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{
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/* alloc chunk, fill it and return it */
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struct label_manager_chunk *lmc =
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XCALLOC(MTYPE_LM_CHUNK, sizeof(struct label_manager_chunk));
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lmc->start = start;
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lmc->end = end;
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lmc->proto = proto;
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lmc->instance = instance;
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lmc->keep = keep;
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return lmc;
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}
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/* attempt to get a specific label chunk */
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struct label_manager_chunk *
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assign_specific_label_chunk(uint8_t proto, unsigned short instance,
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uint8_t keep, uint32_t size, uint32_t base)
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{
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struct label_manager_chunk *lmc;
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struct listnode *node, *next = NULL;
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struct listnode *first_node = NULL;
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struct listnode *last_node = NULL;
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struct listnode *insert_node = NULL;
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/* precompute last label from base and size */
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uint32_t end = base + size - 1;
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/* sanities */
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if ((base < MPLS_LABEL_UNRESERVED_MIN)
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|| (end > MPLS_LABEL_UNRESERVED_MAX)) {
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zlog_err("Invalid LM request arguments: base: %u, size: %u",
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base, size);
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return NULL;
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}
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/* Scan the existing chunks to see if the requested range of labels
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* falls inside any of such chunks */
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for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) {
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/* skip chunks for labels < base */
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if (base > lmc->end)
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continue;
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/* requested range is not covered by any existing, free chunk.
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* Therefore, need to insert a chunk */
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if ((end < lmc->start) && !first_node) {
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insert_node = node;
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break;
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}
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if (!first_node)
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first_node = node;
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/* if chunk is used, cannot honor request */
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if (lmc->proto != NO_PROTO)
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return NULL;
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if (end < lmc->end) {
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last_node = node;
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break;
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}
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}
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/* insert chunk between existing chunks */
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if (insert_node) {
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lmc = create_label_chunk(proto, instance, keep, base, end);
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listnode_add_before(lbl_mgr.lc_list, insert_node, lmc);
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return lmc;
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}
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if (first_node) {
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/* get node past the last one, if there */
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if (last_node)
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last_node = listnextnode(last_node);
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/* delete node coming after the above chunk whose labels are
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* included in the previous one */
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for (node = first_node; node && (node != last_node);
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node = next) {
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next = listnextnode(node);
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list_delete_node(lbl_mgr.lc_list, node);
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}
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lmc = create_label_chunk(proto, instance, keep, base, end);
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if (last_node)
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listnode_add_before(lbl_mgr.lc_list, last_node, lmc);
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else
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listnode_add(lbl_mgr.lc_list, lmc);
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return lmc;
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} else {
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/* create a new chunk past all the existing ones and link at
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* tail */
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lmc = create_label_chunk(proto, instance, keep, base, end);
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listnode_add(lbl_mgr.lc_list, lmc);
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return lmc;
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}
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}
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/**
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* Core function, assigns label chunks
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*
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* It first searches through the list to check if there's one available
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* (previously released). Otherwise it creates and assigns a new one
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*
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* @param proto Daemon protocol of client, to identify the owner
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* @param instance Instance, to identify the owner
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* @param keep If set, avoid garbage collection
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* @param size Size of the label chunk
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* @param base Desired starting label of the chunk; if MPLS_LABEL_BASE_ANY it does not apply
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* @return Pointer to the assigned label chunk, or NULL if the request could not be satisfied
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*/
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struct label_manager_chunk *assign_label_chunk(uint8_t proto,
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unsigned short instance,
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uint8_t keep, uint32_t size,
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uint32_t base)
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{
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struct label_manager_chunk *lmc;
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struct listnode *node;
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uint32_t prev_end = 0;
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/* handle chunks request with a specific base label */
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if (base != MPLS_LABEL_BASE_ANY)
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return assign_specific_label_chunk(proto, instance, keep, size,
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base);
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/* 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->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, 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, keep, start_free,
|
|
start_free + size - 1);
|
|
listnode_add(lbl_mgr.lc_list, lmc);
|
|
return lmc;
|
|
}
|
|
|
|
/**
|
|
* 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 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 start,
|
|
uint32_t end)
|
|
{
|
|
struct listnode *node;
|
|
struct label_manager_chunk *lmc;
|
|
int ret = -1;
|
|
|
|
/* check that size matches */
|
|
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) {
|
|
flog_err(EC_ZEBRA_LM_DAEMON_MISMATCH,
|
|
"%s: Daemon mismatch!!", __func__);
|
|
continue;
|
|
}
|
|
lmc->proto = NO_PROTO;
|
|
lmc->instance = 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;
|
|
}
|
|
|
|
|
|
void label_manager_close(void)
|
|
{
|
|
list_delete(&lbl_mgr.lc_list);
|
|
stream_free(obuf);
|
|
}
|