lldp-tlv.c revision 11e8357164694d8307dea5bcae017c98c5f125ab
/*-*- 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 <net/ethernet.h>
#include <arpa/inet.h>
#include "macro.h"
#include "lldp-tlv.h"
int tlv_section_new(tlv_section **ret) {
tlv_section *s;
s = new0(tlv_section, 1);
if (!s)
return -ENOMEM;
*ret = s;
return 0;
}
void tlv_section_free(tlv_section *m) {
if (!m)
return;
free(m);
}
int tlv_packet_new(tlv_packet **ret) {
tlv_packet *m;
m = new0(tlv_packet, 1);
if (!m)
return -ENOMEM;
LIST_HEAD_INIT(m->sections);
m->n_ref = 1;
*ret = m;
return 0;
}
tlv_packet *sd_lldp_packet_ref(tlv_packet *m) {
if (!m)
return NULL;
assert(m->n_ref > 0);
m->n_ref++;
return m;
}
tlv_packet *sd_lldp_packet_unref(tlv_packet *m) {
tlv_section *s, *n;
if (!m)
return NULL;
assert(m->n_ref > 0);
m->n_ref--;
if (m->n_ref > 0)
return m;
LIST_FOREACH_SAFE(section, s, n, m->sections)
tlv_section_free(s);
free(m);
return NULL;
}
int tlv_packet_append_bytes(tlv_packet *m, const void *data, size_t data_length) {
uint8_t *p;
assert_return(m, -EINVAL);
assert_return(data, -EINVAL);
assert_return(data_length, -EINVAL);
if (m->length + data_length > ETHER_MAX_LEN)
return -ENOMEM;
p = m->pdu + m->length;
memcpy(p, data, data_length);
m->length += data_length;
return 0;
}
int tlv_packet_append_u8(tlv_packet *m, uint8_t data) {
assert_return(m, -EINVAL);
return tlv_packet_append_bytes(m, &data, sizeof(uint8_t));
}
int tlv_packet_append_u16(tlv_packet *m, uint16_t data) {
uint16_t type;
assert_return(m, -EINVAL);
type = htons(data);
return tlv_packet_append_bytes(m, &type, sizeof(uint16_t));
}
int tlv_packet_append_u32(tlv_packet *m, uint32_t data) {
uint32_t type;
assert_return(m, -EINVAL);
type = htonl(data);
return tlv_packet_append_bytes(m, &type, sizeof(uint32_t));
}
int tlv_packet_append_string(tlv_packet *m, char *data, uint16_t size) {
assert_return(m, -EINVAL);
return tlv_packet_append_bytes(m, data, size);
}
int lldp_tlv_packet_open_container(tlv_packet *m, uint16_t type) {
assert_return(m, -EINVAL);
m->container_pos = m->pdu + m->length;
return tlv_packet_append_u16(m, type << 9);
}
int lldp_tlv_packet_close_container(tlv_packet *m) {
uint16_t type;
assert_return(m, -EINVAL);
assert_return(m->container_pos, -EINVAL);
memcpy(&type, m->container_pos, sizeof(uint16_t));
type |= htons(((m->pdu + m->length) - (m->container_pos + 2)) & 0x01ff);
memcpy(m->container_pos, &type, sizeof(uint16_t));
return 0;
}
static inline int tlv_packet_read_internal(tlv_section *m, void **data) {
assert_return(m->read_pos, -EINVAL);
*data = m->read_pos;
return 0;
}
int tlv_packet_read_u8(tlv_packet *m, uint8_t *data) {
void *val = NULL;
int r;
assert_return(m, -EINVAL);
r = tlv_packet_read_internal(m->container, &val);
if (r < 0)
return r;
memcpy(data, val, sizeof(uint8_t));
m->container->read_pos ++;
return 0;
}
int tlv_packet_read_u16(tlv_packet *m, uint16_t *data) {
uint16_t t;
void *val = NULL;
int r;
assert_return(m, -EINVAL);
r = tlv_packet_read_internal(m->container, &val);
if (r < 0)
return r;
memcpy(&t, val, sizeof(uint16_t));
*data = ntohs(t);
m->container->read_pos += 2;
return 0;
}
int tlv_packet_read_u32(tlv_packet *m, uint32_t *data) {
uint32_t t;
void *val;
int r;
assert_return(m, -EINVAL);
r = tlv_packet_read_internal(m->container, &val);
if (r < 0)
return r;
memcpy(&t, val, sizeof(uint32_t));
*data = ntohl(t);
m->container->read_pos += 4;
return r;
}
int tlv_packet_read_string(tlv_packet *m, char **data, uint16_t *data_length) {
void *val = NULL;
int r;
assert_return(m, -EINVAL);
r = tlv_packet_read_internal(m->container, &val);
if (r < 0)
return r;
*data = (char *) val;
*data_length = m->container->length;
m->container->read_pos += m->container->length;
return 0;
}
int tlv_packet_read_bytes(tlv_packet *m, uint8_t **data, uint16_t *data_length) {
void *val = NULL;
int r;
assert_return(m, -EINVAL);
r = tlv_packet_read_internal(m->container, &val);
if (r < 0)
return r;
*data = (uint8_t *) val;
*data_length = m->container->length;
m->container->read_pos += m->container->length;
return 0;
}
/* parse raw TLV packet */
int tlv_packet_parse_pdu(tlv_packet *m, uint16_t size) {
tlv_section *section, *tail;
uint16_t t, l;
uint8_t *p;
int r;
assert_return(m, -EINVAL);
assert_return(size, -EINVAL);
p = m->pdu;
/* extract ethernet herader */
memcpy(&m->mac, p, ETH_ALEN);
p += sizeof(struct ether_header);
for (l = 0; l <= size; ) {
r = tlv_section_new(&section);
if (r < 0)
return r;
memcpy(&t, p, sizeof(uint16_t));
section->type = ntohs(t) >> 9;
section->length = ntohs(t) & 0x01ff;
if (section->type == LLDP_TYPE_END || section->type >=_LLDP_TYPE_MAX) {
tlv_section_free(section);
break;
}
p += 2;
section->data = p;
LIST_FIND_TAIL(section, m->sections, tail);
LIST_INSERT_AFTER(section, m->sections, tail, section);
p += section->length;
l += (section->length + 2);
}
return 0;
}
int lldp_tlv_packet_enter_container(tlv_packet *m, uint16_t type) {
tlv_section *s;
assert_return(m, -EINVAL);
LIST_FOREACH(section, s, m->sections)
if (s->type == type)
break;
if (!s)
return -1;
m->container = s;
m->container->read_pos = s->data;
if (!m->container->read_pos) {
m->container = 0;
return -1;
}
return 0;
}
int lldp_tlv_packet_exit_container(tlv_packet *m) {
assert_return(m, -EINVAL);
m->container = 0;
return 0;
}
static int lldp_tlv_packet_read_u16_tlv(tlv_packet *tlv, uint16_t type, uint16_t *value) {
int r;
assert_return(tlv, -EINVAL);
r = lldp_tlv_packet_enter_container(tlv, type);
if (r < 0)
goto out;
r = tlv_packet_read_u16(tlv, value);
(void) lldp_tlv_packet_exit_container(tlv);
out:
return r;
}
static int lldp_tlv_packet_read_string_tlv(tlv_packet *tlv, uint16_t type, char **data, uint16_t *length) {
char *s;
int r;
assert_return(tlv, -EINVAL);
r = lldp_tlv_packet_enter_container(tlv, type);
if (r < 0)
return r;
r = tlv_packet_read_string(tlv, &s, length);
if (r < 0)
goto out;
*data = (char *) s;
out:
(void) lldp_tlv_packet_exit_container(tlv);
return r;
}
int sd_lldp_packet_read_chassis_id(tlv_packet *tlv,
uint8_t *type,
uint8_t **data,
uint16_t *length) {
uint8_t subtype;
int r;
assert_return(tlv, -EINVAL);
r = lldp_tlv_packet_enter_container(tlv, LLDP_TYPE_CHASSIS_ID);
if (r < 0)
goto out2;
r = tlv_packet_read_u8(tlv, &subtype);
if (r < 0)
goto out1;
switch (subtype) {
case LLDP_CHASSIS_SUBTYPE_MAC_ADDRESS:
r = tlv_packet_read_bytes(tlv, data, length);
if (r < 0)
goto out1;
break;
default:
r = -EOPNOTSUPP;
break;
}
*type = subtype;
out1:
(void) lldp_tlv_packet_exit_container(tlv);
out2:
return r;
}
int sd_lldp_packet_read_port_id(tlv_packet *tlv,
uint8_t *type,
uint8_t **data,
uint16_t *length) {
uint8_t subtype;
char *s;
int r;
assert_return(tlv, -EINVAL);
r = lldp_tlv_packet_enter_container(tlv, LLDP_TYPE_PORT_ID);
if (r < 0)
goto out2;
r = tlv_packet_read_u8(tlv, &subtype);
if (r < 0)
goto out1;
switch (subtype) {
case LLDP_PORT_SUBTYPE_PORT_COMPONENT:
case LLDP_PORT_SUBTYPE_INTERFACE_ALIAS:
case LLDP_PORT_SUBTYPE_INTERFACE_NAME:
case LLDP_PORT_SUBTYPE_LOCALLY_ASSIGNED:
r = tlv_packet_read_string(tlv, &s, length);
if (r < 0)
goto out1;
*data = (uint8_t *) s;
break;
case LLDP_PORT_SUBTYPE_MAC_ADDRESS:
r = tlv_packet_read_bytes(tlv, data, length);
if (r < 0)
goto out1;
break;
default:
r = -EOPNOTSUPP;
break;
}
*type = subtype;
out1:
(void) lldp_tlv_packet_exit_container(tlv);
out2:
return r;
}
int sd_lldp_packet_read_ttl(tlv_packet *tlv, uint16_t *ttl) {
return lldp_tlv_packet_read_u16_tlv(tlv, LLDP_TYPE_TTL, ttl);
}
int sd_lldp_packet_read_system_name(tlv_packet *tlv,
char **data,
uint16_t *length) {
return lldp_tlv_packet_read_string_tlv(tlv, LLDP_TYPE_SYSTEM_NAME, data, length);
}
int sd_lldp_packet_read_system_description(tlv_packet *tlv,
char **data,
uint16_t *length) {
return lldp_tlv_packet_read_string_tlv(tlv, LLDP_TYPE_SYSTEM_DESCRIPTION, data, length);
}
int sd_lldp_packet_read_port_description(tlv_packet *tlv,
char **data,
uint16_t *length) {
return lldp_tlv_packet_read_string_tlv(tlv, LLDP_TYPE_PORT_DESCRIPTION, data, length);
}
int sd_lldp_packet_read_system_capability(tlv_packet *tlv, uint16_t *data) {
return lldp_tlv_packet_read_u16_tlv(tlv, LLDP_TYPE_SYSTEM_CAPABILITIES, data);
}
int sd_lldp_packet_get_destination_type(tlv_packet *tlv, int *dest) {
assert_return(tlv, -EINVAL);
assert_return(dest, -EINVAL);
/* 802.1AB-2009, Table 7-1 */
if (!memcmp(&tlv->mac, LLDP_MAC_NEAREST_BRIDGE, ETH_ALEN))
*dest = SD_LLDP_DESTINATION_TYPE_NEAREST_BRIDGE;
else if (!memcmp(&tlv->mac, LLDP_MAC_NEAREST_NON_TPMR_BRIDGE, ETH_ALEN))
*dest = SD_LLDP_DESTINATION_TYPE_NEAREST_NON_TPMR_BRIDGE;
else if (!memcmp(&tlv->mac, LLDP_MAC_NEAREST_CUSTOMER_BRIDGE, ETH_ALEN))
*dest = SD_LLDP_DESTINATION_TYPE_NEAREST_CUSTOMER_BRIDGE;
else
return -EINVAL;
return 0;
}