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/*
* Label Manager for FRR
*
* Copyright (C) 2017 by Bingen Eguzkitza,
* Volta Networks Inc.
*
* This file is part of FreeRangeRouting (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 <stdio.h>
#include <string.h>
#include <sys/types.h>
#include "zebra.h"
#include "zserv.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 "label_manager.h"
#define CONNECTION_DELAY 5
struct label_manager lbl_mgr;
extern struct zebra_privs_t zserv_privs;
DEFINE_MGROUP(LBL_MGR, "Label Manager");
DEFINE_MTYPE_STATIC(LBL_MGR, LM_CHUNK, "Label Manager Chunk");
/* In case this zebra daemon is not acting as label manager,
* it will be a proxy to relay messages to external label manager
* This zclient thus is to connect to it
*/
static struct zclient *zclient;
bool lm_is_external;
static void delete_label_chunk(void *val)
{
XFREE(MTYPE_LM_CHUNK, val);
}
static int relay_response_back(struct zserv *zserv)
{
int ret = 0;
struct stream *src, *dst;
u_int16_t size = 0;
u_char marker;
u_char version;
vrf_id_t vrf_id;
u_int16_t resp_cmd;
src = zclient->ibuf;
dst = zserv->obuf;
stream_reset(src);
ret = zclient_read_header(src, zclient->sock, &size, &marker, &version,
&vrf_id, &resp_cmd);
if (ret < 0 && errno != EAGAIN) {
zlog_err("%s: Error reading Label Manager response: %s",
__func__, strerror(errno));
return -1;
}
zlog_debug("%s: Label Manager response received, %d bytes", __func__,
size);
if (size == 0)
return -1;
/* send response back */
stream_copy(dst, src);
ret = writen(zserv->sock, dst->data, stream_get_endp(dst));
if (ret <= 0) {
zlog_err("%s: Error sending Label Manager response back: %s",
__func__, strerror(errno));
return -1;
}
zlog_debug("%s: Label Manager response (%d bytes) sent back", __func__,
ret);
return 0;
}
static int lm_zclient_read(struct thread *t)
{
struct zserv *zserv;
int ret;
/* Get socket to zebra. */
zserv = THREAD_ARG(t);
zclient->t_read = NULL;
/* read response and send it back */
ret = relay_response_back(zserv);
return ret;
}
static int reply_error(int cmd, struct zserv *zserv, vrf_id_t vrf_id)
{
struct stream *s;
s = zserv->obuf;
stream_reset(s);
zserv_create_header(s, cmd, vrf_id);
/* result */
stream_putc(s, 1);
/* Write packet size. */
stream_putw_at(s, 0, stream_get_endp(s));
return writen(zserv->sock, s->data, stream_get_endp(s));
}
/**
* Receive a request to get or release a label chunk and forward it to external
* label manager.
*
* It's called from zserv in case it's not an actual label manager, but just a
* proxy.
*
* @param cmd Type of request (connect, get or release)
* @param zserv
* @return 0 on success, -1 otherwise
*/
int zread_relay_label_manager_request(int cmd, struct zserv *zserv,
vrf_id_t vrf_id)
{
struct stream *src, *dst;
int ret = 0;
if (zclient->sock < 0) {
zlog_err(
"%s: Error relaying label chunk request: no zclient socket",
__func__);
reply_error(cmd, zserv, vrf_id);
return -1;
}
/* in case there's any incoming message enqueued, read and forward it */
while (ret == 0)
ret = relay_response_back(zserv);
/* Send request to external label manager */
src = zserv->ibuf;
dst = zclient->obuf;
stream_copy(dst, src);
ret = writen(zclient->sock, dst->data, stream_get_endp(dst));
if (ret <= 0) {
zlog_err("%s: Error relaying label chunk request: %s", __func__,
strerror(errno));
reply_error(cmd, zserv, vrf_id);
return -1;
}
zlog_debug("%s: Label chunk request relayed. %d bytes sent", __func__,
ret);
/* Release label chunk has no response */
if (cmd == ZEBRA_RELEASE_LABEL_CHUNK)
return 0;
/* make sure we listen to the response */
if (!zclient->t_read)
thread_add_read(zclient->master, lm_zclient_read, zserv,
zclient->sock, &zclient->t_read);
return 0;
}
static int lm_zclient_connect(struct thread *t)
{
zclient->t_connect = NULL;
if (zclient->sock >= 0)
return 0;
if (zclient_socket_connect(zclient) < 0) {
zlog_err("Error connecting synchronous zclient!");
thread_add_timer(zebrad.master, lm_zclient_connect, zclient,
CONNECTION_DELAY, &zclient->t_connect);
return -1;
}
/* make socket non-blocking */
if (set_nonblocking(zclient->sock) < 0)
zlog_warn("%s: set_nonblocking(%d) failed", __func__,
zclient->sock);
return 0;
}
/**
* Function to initialize zclient in case this is not an actual
* label manager, but just a proxy to an external one.
*
* @param lm_zserv_path Path to zserv socket of external label manager
*/
static void lm_zclient_init(char *lm_zserv_path)
{
if (lm_zserv_path)
frr_zclient_addr(&zclient_addr, &zclient_addr_len,
lm_zserv_path);
/* Set default values. */
zclient = zclient_new_notify(zebrad.master, &zclient_options_default);
zclient->privs = &zserv_privs;
zclient->sock = -1;
zclient->t_connect = NULL;
lm_zclient_connect(NULL);
}
/**
* Init label manager (or proxy to an external one)
*/
void label_manager_init(char *lm_zserv_path)
{
/* this is an actual label manager */
if (!lm_zserv_path) {
zlog_debug("Initializing own label manager");
lm_is_external = false;
lbl_mgr.lc_list = list_new();
lbl_mgr.lc_list->del = delete_label_chunk;
} else { /* it's acting just as a proxy */
zlog_debug("Initializing external label manager at %s",
lm_zserv_path);
lm_is_external = true;
lm_zclient_init(lm_zserv_path);
}
}
/**
* Core function, assigns label cunks
*
* 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
* @para size Size of the label chunk
* @return Pointer to the assigned label chunk
*/
struct label_manager_chunk *assign_label_chunk(u_char proto, u_short instance,
u_char keep, uint32_t size)
{
struct label_manager_chunk *lmc;
struct listnode *node;
/* 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;
}
}
/* otherwise create a new one */
lmc = XCALLOC(MTYPE_LM_CHUNK, sizeof(struct label_manager_chunk));
if (!lmc)
return NULL;
if (list_isempty(lbl_mgr.lc_list))
lmc->start = MPLS_MIN_UNRESERVED_LABEL;
else
lmc->start = ((struct label_manager_chunk *)listgetdata(
listtail(lbl_mgr.lc_list)))
->end
+ 1;
if (lmc->start > MPLS_MAX_UNRESERVED_LABEL - size + 1) {
zlog_err("Reached max labels. Start: %u, size: %u", lmc->start,
size);
XFREE(MTYPE_LM_CHUNK, lmc);
return NULL;
}
lmc->end = lmc->start + size - 1;
lmc->proto = proto;
lmc->instance = instance;
lmc->keep = keep;
listnode_add(lbl_mgr.lc_list, lmc);
return lmc;
}
/**
* Core function, release no longer used label cunks
*
* @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(u_char proto, u_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) {
zlog_err("%s: Daemon mismatch!!", __func__);
continue;
}
lmc->proto = NO_PROTO;
lmc->instance = 0;
lmc->keep = 0;
ret = 0;
break;
}
if (ret != 0)
zlog_err("%s: Label chunk not released!!", __func__);
return ret;
}
/**
* 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_chunks(u_char proto, u_short instance)
{
struct listnode *node;
struct label_manager_chunk *lmc;
int count = 0;
int ret;
for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) {
if (lmc->proto == proto && lmc->instance == instance
&& lmc->keep == 0) {
ret = release_label_chunk(lmc->proto, lmc->instance,
lmc->start, lmc->end);
if (ret == 0)
count++;
}
}
zlog_debug("%s: Released %d label chunks", __func__, count);
return count;
}
void label_manager_close()
{
list_delete_and_null(&lbl_mgr.lc_list);
}
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