src/libsystemd-network/lldp-internal.c - systemd-stable - Rivoreo Source Code Repositories

 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/

 /***
   This file is part of systemd.

   Copyright (C) 2014 Tom Gundersen
   Copyright (C) 2014 Susant Sahani

   systemd is free software; you can redistribute it and/or modify it
   under the terms of the GNU Lesser General Public License as published by
   the Free Software Foundation; either version 2.1 of the License, or
   (at your option) any later version.

   systemd 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public License
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/

 #include "sd-lldp.h"

 #include "alloc-util.h"
 #include "lldp-internal.h"

 /* We store maximum 1K chassis entries */
 #define LLDP_MIB_MAX_CHASSIS 1024

 /* Maximum Ports can be attached to any chassis */
 #define LLDP_MIB_MAX_PORT_PER_CHASSIS 32

 /* 10.5.5.2.2 mibUpdateObjects ()
  * The mibUpdateObjects () procedure updates the MIB objects corresponding to
  * the TLVs contained in the received LLDPDU for the LLDP remote system
  * indicated by the LLDP remote systems update process defined in 10.3.5 */

 int lldp_mib_update_objects(lldp_chassis *c, tlv_packet *tlv) {
         lldp_neighbour_port *p;
         uint16_t length, ttl;
         uint8_t *data;
         uint8_t type;
         int r;

         assert_return(c, -EINVAL);
         assert_return(tlv, -EINVAL);

         r = sd_lldp_packet_read_port_id(tlv, &type, &data, &length);
         if (r < 0)
                 return r;

         /* Update the packet if we already have */
         LIST_FOREACH(port, p, c->ports) {

                 if ((p->type == type && p->length == length && !memcmp(p->data, data, p->length))) {

                         r = sd_lldp_packet_read_ttl(tlv, &ttl);
                         if (r < 0)
                                 return r;

                         p->until = ttl * USEC_PER_SEC + now(clock_boottime_or_monotonic());

                         sd_lldp_packet_unref(p->packet);
                         p->packet = tlv;

                         prioq_reshuffle(p->c->by_expiry, p, &p->prioq_idx);

                         return 0;
                 }
         }

         return -1;
 }

 int lldp_mib_remove_objects(lldp_chassis *c, tlv_packet *tlv) {
         lldp_neighbour_port *p, *q;
         uint8_t *data;
         uint16_t length;
         uint8_t type;
         int r;

         assert_return(c, -EINVAL);
         assert_return(tlv, -EINVAL);

         r = sd_lldp_packet_read_port_id(tlv, &type, &data, &length);
         if (r < 0)
                 return r;

         LIST_FOREACH_SAFE(port, p, q, c->ports) {

                 /* Find the port */
                 if (p->type == type && p->length == length && !memcmp(p->data, data, p->length)) {
                         lldp_neighbour_port_remove_and_free(p);
                         break;
                 }
         }

         return 0;
 }

 int lldp_mib_add_objects(Prioq *by_expiry,
                          Hashmap *neighbour_mib,
                          tlv_packet *tlv) {
         _cleanup_lldp_neighbour_port_free_ lldp_neighbour_port *p = NULL;
         _cleanup_lldp_chassis_free_ lldp_chassis *c = NULL;
         lldp_chassis_id chassis_id;
         bool new_chassis = false;
         uint8_t subtype, *data;
         uint16_t ttl, length;
         int r;

         assert_return(by_expiry, -EINVAL);
         assert_return(neighbour_mib, -EINVAL);
         assert_return(tlv, -EINVAL);

         r = sd_lldp_packet_read_chassis_id(tlv, &subtype, &data, &length);
         if (r < 0)
                 goto drop;

         r = sd_lldp_packet_read_ttl(tlv, &ttl);
         if (r < 0)
                 goto drop;

         /* Make hash key */
         chassis_id.type = subtype;
         chassis_id.length = length;
         chassis_id.data = data;

         /* Try to find the Chassis */
         c = hashmap_get(neighbour_mib, &chassis_id);
         if (!c) {

                 /* Don't create chassis if ttl 0 is received . Silently drop it */
                 if (ttl == 0) {
                         log_lldp("TTL value 0 received. Skiping Chassis creation.");
                         goto drop;
                 }

                 /* Admission Control: Can we store this packet ? */
                 if (hashmap_size(neighbour_mib) >= LLDP_MIB_MAX_CHASSIS) {

                         log_lldp("Exceeding number of chassie: %d. Dropping ...",
                                  hashmap_size(neighbour_mib));
                         goto drop;
                 }

                 r = lldp_chassis_new(tlv, by_expiry, neighbour_mib, &c);
                 if (r < 0)
                         goto drop;

                 new_chassis = true;

                 r = hashmap_put(neighbour_mib, &c->chassis_id, c);
                 if (r < 0)
                         goto drop;

         } else {

                 /* When the TTL field is set to zero, the receiving LLDP agent is notified all
                  * system information associated with the LLDP agent/port is to be deleted */
                 if (ttl == 0) {
                         log_lldp("TTL value 0 received . Deleting associated Port ...");

                         lldp_mib_remove_objects(c, tlv);

                         c = NULL;
                         goto drop;
                 }

                 /* if we already have this port just update it */
                 r = lldp_mib_update_objects(c, tlv);
                 if (r >= 0) {
                         c = NULL;
                         return r;
                 }

                 /* Admission Control: Can this port attached to the existing chassis ? */
                 if (c->n_ref >= LLDP_MIB_MAX_PORT_PER_CHASSIS) {
                         log_lldp("Port limit reached. Chassis has: %d ports. Dropping ...", c->n_ref);

                         c = NULL;
                         goto drop;
                 }
         }

         /* This is a new port */
         r = lldp_neighbour_port_new(c, tlv, &p);
         if (r < 0)
                 goto drop;

         r = prioq_put(c->by_expiry, p, &p->prioq_idx);
         if (r < 0)
                 goto drop;

         /* Attach new port to chassis */
         LIST_PREPEND(port, c->ports, p);
         c->n_ref ++;

         p = NULL;
         c = NULL;

         return 0;

  drop:
         sd_lldp_packet_unref(tlv);

         if (new_chassis)
                 hashmap_remove(neighbour_mib, &c->chassis_id);

         return r;
 }

 void lldp_neighbour_port_remove_and_free(lldp_neighbour_port *p) {
         lldp_chassis *c;

         assert(p);
         assert(p->c);

         c = p->c;

         prioq_remove(c->by_expiry, p, &p->prioq_idx);

         LIST_REMOVE(port, c->ports, p);
         lldp_neighbour_port_free(p);

         /* Drop the Chassis if no port is attached  */
         c->n_ref --;
         if (c->n_ref <= 1) {
                 hashmap_remove(c->neighbour_mib, &c->chassis_id);
                 lldp_chassis_free(c);
         }
 }

 void lldp_neighbour_port_free(lldp_neighbour_port *p) {

         if(!p)
                 return;

         sd_lldp_packet_unref(p->packet);

         free(p->data);
         free(p);
 }

 int lldp_neighbour_port_new(lldp_chassis *c,
                             tlv_packet *tlv,
                             lldp_neighbour_port **ret) {
         _cleanup_lldp_neighbour_port_free_ lldp_neighbour_port *p = NULL;
         uint16_t length, ttl;
         uint8_t *data;
         uint8_t type;
         int r;

         assert(tlv);

         r = sd_lldp_packet_read_port_id(tlv, &type, &data, &length);
         if (r < 0)
                 return r;

         r = sd_lldp_packet_read_ttl(tlv, &ttl);
         if (r < 0)
                 return r;

         p = new0(lldp_neighbour_port, 1);
         if (!p)
                 return -ENOMEM;

         p->c = c;
         p->type = type;
         p->length = length;
         p->packet = tlv;
         p->prioq_idx = PRIOQ_IDX_NULL;
         p->until = ttl * USEC_PER_SEC + now(clock_boottime_or_monotonic());

         p->data = memdup(data, length);
         if (!p->data)
                 return -ENOMEM;

         *ret = p;
         p = NULL;

         return 0;
 }

 void lldp_chassis_free(lldp_chassis *c) {

         if (!c)
                 return;

         if (c->n_ref > 1)
                 return;

         free(c->chassis_id.data);
         free(c);
 }

 int lldp_chassis_new(tlv_packet *tlv,
                      Prioq *by_expiry,
                      Hashmap *neighbour_mib,
                      lldp_chassis **ret) {
         _cleanup_lldp_chassis_free_ lldp_chassis *c = NULL;
         uint16_t length;
         uint8_t *data;
         uint8_t type;
         int r;

         assert(tlv);

         r = sd_lldp_packet_read_chassis_id(tlv, &type, &data, &length);
         if (r < 0)
                 return r;

         c = new0(lldp_chassis, 1);
         if (!c)
                 return -ENOMEM;

         c->n_ref = 1;
         c->chassis_id.type = type;
         c->chassis_id.length = length;

         c->chassis_id.data = memdup(data, length);
         if (!c->chassis_id.data)
                 return -ENOMEM;

         LIST_HEAD_INIT(c->ports);

         c->by_expiry = by_expiry;
         c->neighbour_mib = neighbour_mib;

         *ret = c;
         c = NULL;

         return 0;
 }

 int lldp_receive_packet(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
         _cleanup_lldp_packet_unref_ tlv_packet *packet = NULL;
         tlv_packet *p;
         uint16_t length;
         int r;

         assert(fd);
         assert(userdata);

         r = tlv_packet_new(&packet);
         if (r < 0)
                 return r;

         length = read(fd, &packet->pdu, sizeof(packet->pdu));

         /* Silently drop the packet */
         if ((size_t) length > ETHER_MAX_LEN)
                 return 0;

         packet->userdata = userdata;

         p = packet;
         packet = NULL;

         return lldp_handle_packet(p, (uint16_t) length);
 }
	/-- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil --/

	/***
	This file is part of systemd.

	Copyright (C) 2014 Tom Gundersen
	Copyright (C) 2014 Susant Sahani

	systemd is free software; you can redistribute it and/or modify it
	under the terms of the GNU Lesser General Public License as published by
	the Free Software Foundation; either version 2.1 of the License, or
	(at your option) any later version.

	systemd 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
	Lesser General Public License for more details.

	You should have received a copy of the GNU Lesser General Public License
	along with systemd; If not, see <http://www.gnu.org/licenses/>.
	***/

	#include "sd-lldp.h"

	#include "alloc-util.h"
	#include "lldp-internal.h"

	/* We store maximum 1K chassis entries */
	#define LLDP_MIB_MAX_CHASSIS 1024

	/* Maximum Ports can be attached to any chassis */
	#define LLDP_MIB_MAX_PORT_PER_CHASSIS 32

	/* 10.5.5.2.2 mibUpdateObjects ()
	* The mibUpdateObjects () procedure updates the MIB objects corresponding to
	* the TLVs contained in the received LLDPDU for the LLDP remote system
	* indicated by the LLDP remote systems update process defined in 10.3.5 */

	int lldp_mib_update_objects(lldp_chassis c, tlv_packet tlv) {
	lldp_neighbour_port *p;
	uint16_t length, ttl;
	uint8_t *data;
	uint8_t type;
	int r;

	assert_return(c, -EINVAL);
	assert_return(tlv, -EINVAL);

	r = sd_lldp_packet_read_port_id(tlv, &type, &data, &length);
	if (r < 0)
	return r;

	/* Update the packet if we already have */
	LIST_FOREACH(port, p, c->ports) {

	if ((p->type == type && p->length == length && !memcmp(p->data, data, p->length))) {

	r = sd_lldp_packet_read_ttl(tlv, &ttl);
	if (r < 0)
	return r;

	p->until = ttl * USEC_PER_SEC + now(clock_boottime_or_monotonic());

	sd_lldp_packet_unref(p->packet);
	p->packet = tlv;

	prioq_reshuffle(p->c->by_expiry, p, &p->prioq_idx);

	return 0;
	}
	}

	return -1;
	}

	int lldp_mib_remove_objects(lldp_chassis c, tlv_packet tlv) {
	lldp_neighbour_port p, q;
	uint8_t *data;
	uint16_t length;
	uint8_t type;
	int r;

	assert_return(c, -EINVAL);
	assert_return(tlv, -EINVAL);

	r = sd_lldp_packet_read_port_id(tlv, &type, &data, &length);
	if (r < 0)
	return r;

	LIST_FOREACH_SAFE(port, p, q, c->ports) {

	/* Find the port */
	if (p->type == type && p->length == length && !memcmp(p->data, data, p->length)) {
	lldp_neighbour_port_remove_and_free(p);
	break;
	}
	}

	return 0;
	}

	int lldp_mib_add_objects(Prioq *by_expiry,
	Hashmap *neighbour_mib,
	tlv_packet *tlv) {
	_cleanup_lldp_neighbour_port_free_ lldp_neighbour_port *p = NULL;
	_cleanup_lldp_chassis_free_ lldp_chassis *c = NULL;
	lldp_chassis_id chassis_id;
	bool new_chassis = false;
	uint8_t subtype, *data;
	uint16_t ttl, length;
	int r;

	assert_return(by_expiry, -EINVAL);
	assert_return(neighbour_mib, -EINVAL);
	assert_return(tlv, -EINVAL);

	r = sd_lldp_packet_read_chassis_id(tlv, &subtype, &data, &length);
	if (r < 0)
	goto drop;

	r = sd_lldp_packet_read_ttl(tlv, &ttl);
	if (r < 0)
	goto drop;

	/* Make hash key */
	chassis_id.type = subtype;
	chassis_id.length = length;
	chassis_id.data = data;

	/* Try to find the Chassis */
	c = hashmap_get(neighbour_mib, &chassis_id);
	if (!c) {

	/* Don't create chassis if ttl 0 is received . Silently drop it */
	if (ttl == 0) {
	log_lldp("TTL value 0 received. Skiping Chassis creation.");
	goto drop;
	}

	/* Admission Control: Can we store this packet ? */
	if (hashmap_size(neighbour_mib) >= LLDP_MIB_MAX_CHASSIS) {

	log_lldp("Exceeding number of chassie: %d. Dropping ...",
	hashmap_size(neighbour_mib));
	goto drop;
	}

	r = lldp_chassis_new(tlv, by_expiry, neighbour_mib, &c);
	if (r < 0)
	goto drop;

	new_chassis = true;

	r = hashmap_put(neighbour_mib, &c->chassis_id, c);
	if (r < 0)
	goto drop;

	} else {

	/* When the TTL field is set to zero, the receiving LLDP agent is notified all
	* system information associated with the LLDP agent/port is to be deleted */
	if (ttl == 0) {
	log_lldp("TTL value 0 received . Deleting associated Port ...");

	lldp_mib_remove_objects(c, tlv);

	c = NULL;
	goto drop;
	}

	/* if we already have this port just update it */
	r = lldp_mib_update_objects(c, tlv);
	if (r >= 0) {
	c = NULL;
	return r;
	}

	/* Admission Control: Can this port attached to the existing chassis ? */
	if (c->n_ref >= LLDP_MIB_MAX_PORT_PER_CHASSIS) {
	log_lldp("Port limit reached. Chassis has: %d ports. Dropping ...", c->n_ref);

	c = NULL;
	goto drop;
	}
	}

	/* This is a new port */
	r = lldp_neighbour_port_new(c, tlv, &p);
	if (r < 0)
	goto drop;

	r = prioq_put(c->by_expiry, p, &p->prioq_idx);
	if (r < 0)
	goto drop;

	/* Attach new port to chassis */
	LIST_PREPEND(port, c->ports, p);
	c->n_ref ++;

	p = NULL;
	c = NULL;

	return 0;

	drop:
	sd_lldp_packet_unref(tlv);

	if (new_chassis)
	hashmap_remove(neighbour_mib, &c->chassis_id);

	return r;
	}

	void lldp_neighbour_port_remove_and_free(lldp_neighbour_port *p) {
	lldp_chassis *c;

	assert(p);
	assert(p->c);

	c = p->c;

	prioq_remove(c->by_expiry, p, &p->prioq_idx);

	LIST_REMOVE(port, c->ports, p);
	lldp_neighbour_port_free(p);

	/* Drop the Chassis if no port is attached */
	c->n_ref --;
	if (c->n_ref <= 1) {
	hashmap_remove(c->neighbour_mib, &c->chassis_id);
	lldp_chassis_free(c);
	}
	}

	void lldp_neighbour_port_free(lldp_neighbour_port *p) {

	if(!p)
	return;

	sd_lldp_packet_unref(p->packet);

	free(p->data);
	free(p);
	}

	int lldp_neighbour_port_new(lldp_chassis *c,
	tlv_packet *tlv,
	lldp_neighbour_port **ret) {
	_cleanup_lldp_neighbour_port_free_ lldp_neighbour_port *p = NULL;
	uint16_t length, ttl;
	uint8_t *data;
	uint8_t type;
	int r;

	assert(tlv);

	r = sd_lldp_packet_read_port_id(tlv, &type, &data, &length);
	if (r < 0)
	return r;

	r = sd_lldp_packet_read_ttl(tlv, &ttl);
	if (r < 0)
	return r;

	p = new0(lldp_neighbour_port, 1);
	if (!p)
	return -ENOMEM;

	p->c = c;
	p->type = type;
	p->length = length;
	p->packet = tlv;
	p->prioq_idx = PRIOQ_IDX_NULL;
	p->until = ttl * USEC_PER_SEC + now(clock_boottime_or_monotonic());

	p->data = memdup(data, length);
	if (!p->data)
	return -ENOMEM;

	*ret = p;
	p = NULL;

	return 0;
	}

	void lldp_chassis_free(lldp_chassis *c) {

	if (!c)
	return;

	if (c->n_ref > 1)
	return;

	free(c->chassis_id.data);
	free(c);
	}

	int lldp_chassis_new(tlv_packet *tlv,
	Prioq *by_expiry,
	Hashmap *neighbour_mib,
	lldp_chassis **ret) {
	_cleanup_lldp_chassis_free_ lldp_chassis *c = NULL;
	uint16_t length;
	uint8_t *data;
	uint8_t type;
	int r;

	assert(tlv);

	r = sd_lldp_packet_read_chassis_id(tlv, &type, &data, &length);
	if (r < 0)
	return r;

	c = new0(lldp_chassis, 1);
	if (!c)
	return -ENOMEM;

	c->n_ref = 1;
	c->chassis_id.type = type;
	c->chassis_id.length = length;

	c->chassis_id.data = memdup(data, length);
	if (!c->chassis_id.data)
	return -ENOMEM;

	LIST_HEAD_INIT(c->ports);

	c->by_expiry = by_expiry;
	c->neighbour_mib = neighbour_mib;

	*ret = c;
	c = NULL;

	return 0;
	}

	int lldp_receive_packet(sd_event_source s, int fd, uint32_t revents, void userdata) {
	_cleanup_lldp_packet_unref_ tlv_packet *packet = NULL;
	tlv_packet *p;
	uint16_t length;
	int r;

	assert(fd);
	assert(userdata);

	r = tlv_packet_new(&packet);
	if (r < 0)
	return r;

	length = read(fd, &packet->pdu, sizeof(packet->pdu));

	/* Silently drop the packet */
	if ((size_t) length > ETHER_MAX_LEN)
	return 0;

	packet->userdata = userdata;

	p = packet;
	packet = NULL;

	return lldp_handle_packet(p, (uint16_t) length);
	}