diff options
Diffstat (limited to 'src/plugins/lldp/lldp_input.c')
| -rw-r--r-- | src/plugins/lldp/lldp_input.c | 302 |
1 files changed, 302 insertions, 0 deletions
diff --git a/src/plugins/lldp/lldp_input.c b/src/plugins/lldp/lldp_input.c new file mode 100644 index 00000000000..327ef10f9de --- /dev/null +++ b/src/plugins/lldp/lldp_input.c @@ -0,0 +1,302 @@ +/* + * Copyright (c) 2011-2016 Cisco and/or its affiliates. + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at: + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +/** + * @file + * @brief LLDP packet parsing implementation + */ +#include <lldp/lldp_node.h> +#include <lldp/lldp_protocol.h> +#include <vlibmemory/api.h> + +typedef struct +{ + u32 hw_if_index; + u8 chassis_id_len; + u8 chassis_id_subtype; + u8 portid_len; + u8 portid_subtype; + u16 ttl; + u8 data[0]; /* this contains both chassis id (chassis_id_len bytes) and port + id (portid_len bytes) */ +} lldp_intf_update_t; + +static void +lldp_rpc_update_peer_cb (const lldp_intf_update_t * a) +{ + ASSERT (vlib_get_thread_index () == 0); + + lldp_intf_t *n = lldp_get_intf (&lldp_main, a->hw_if_index); + if (!n) + { + /* LLDP turned off for this interface, ignore the update */ + return; + } + const u8 *chassis_id = a->data; + const u8 *portid = a->data + a->chassis_id_len; + + if (n->chassis_id) + { + _vec_len (n->chassis_id) = 0; + } + vec_add (n->chassis_id, chassis_id, a->chassis_id_len); + n->chassis_id_subtype = a->chassis_id_subtype; + if (n->port_id) + { + _vec_len (n->port_id) = 0; + } + vec_add (n->port_id, portid, a->portid_len); + n->port_id_subtype = a->portid_subtype; + n->ttl = a->ttl; + n->last_heard = vlib_time_now (lldp_main.vlib_main); +} + +static void +lldp_rpc_update_peer (u32 hw_if_index, const u8 * chid, u8 chid_len, + u8 chid_subtype, const u8 * portid, + u8 portid_len, u8 portid_subtype, u16 ttl) +{ + const size_t data_size = + sizeof (lldp_intf_update_t) + chid_len + portid_len; + u8 data[data_size]; + lldp_intf_update_t *u = (lldp_intf_update_t *) data; + u->hw_if_index = hw_if_index; + u->chassis_id_len = chid_len; + u->chassis_id_subtype = chid_subtype; + u->ttl = ttl; + u->portid_len = portid_len; + u->portid_subtype = portid_subtype; + clib_memcpy (u->data, chid, chid_len); + clib_memcpy (u->data + chid_len, portid, portid_len); + vl_api_rpc_call_main_thread (lldp_rpc_update_peer_cb, data, data_size); +} + +lldp_tlv_code_t +lldp_tlv_get_code (const lldp_tlv_t * tlv) +{ + return tlv->head.byte1 >> 1; +} + +void +lldp_tlv_set_code (lldp_tlv_t * tlv, lldp_tlv_code_t code) +{ + tlv->head.byte1 = (tlv->head.byte1 & 1) + (code << 1); +} + +u16 +lldp_tlv_get_length (const lldp_tlv_t * tlv) +{ + return (((u16) (tlv->head.byte1 & 1)) << 8) + tlv->head.byte2; +} + +void +lldp_tlv_set_length (lldp_tlv_t * tlv, u16 length) +{ + tlv->head.byte2 = length & ((1 << 8) - 1); + if (length > (1 << 8) - 1) + { + tlv->head.byte1 |= 1; + } + else + { + tlv->head.byte1 &= (1 << 8) - 2; + } +} + +lldp_main_t lldp_main; + +static int +lldp_packet_scan (u32 hw_if_index, const lldp_tlv_t * pkt) +{ + const lldp_tlv_t *tlv = pkt; + +#define TLV_VIOLATES_PKT_BOUNDARY(pkt, tlv) \ + (((((u8 *)tlv) + sizeof (lldp_tlv_t)) > ((u8 *)pkt + vec_len (pkt))) || \ + ((((u8 *)tlv) + lldp_tlv_get_length (tlv)) > ((u8 *)pkt + vec_len (pkt)))) + + /* first tlv is always chassis id, followed by port id and ttl tlvs */ + if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) || + LLDP_TLV_NAME (chassis_id) != lldp_tlv_get_code (tlv)) + { + return LLDP_ERROR_BAD_TLV; + } + + u16 l = lldp_tlv_get_length (tlv); + if (l < STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype) + + LLDP_MIN_CHASS_ID_LEN || + l > STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype) + + LLDP_MAX_CHASS_ID_LEN) + { + return LLDP_ERROR_BAD_TLV; + } + + u8 chid_subtype = ((lldp_chassis_id_tlv_t *) tlv)->subtype; + u8 *chid = ((lldp_chassis_id_tlv_t *) tlv)->id; + u8 chid_len = l - STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype); + + tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + l); + + if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) || + LLDP_TLV_NAME (port_id) != lldp_tlv_get_code (tlv)) + { + return LLDP_ERROR_BAD_TLV; + } + l = lldp_tlv_get_length (tlv); + if (l < STRUCT_SIZE_OF (lldp_port_id_tlv_t, subtype) + + LLDP_MIN_PORT_ID_LEN || + l > STRUCT_SIZE_OF (lldp_chassis_id_tlv_t, subtype) + + LLDP_MAX_PORT_ID_LEN) + { + return LLDP_ERROR_BAD_TLV; + } + + u8 portid_subtype = ((lldp_port_id_tlv_t *) tlv)->subtype; + u8 *portid = ((lldp_port_id_tlv_t *) tlv)->id; + u8 portid_len = l - STRUCT_SIZE_OF (lldp_port_id_tlv_t, subtype); + + tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + l); + + if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) || + LLDP_TLV_NAME (ttl) != lldp_tlv_get_code (tlv)) + { + return LLDP_ERROR_BAD_TLV; + } + l = lldp_tlv_get_length (tlv); + if (l != STRUCT_SIZE_OF (lldp_ttl_tlv_t, ttl)) + { + return LLDP_ERROR_BAD_TLV; + } + u16 ttl = ntohs (((lldp_ttl_tlv_t *) tlv)->ttl); + tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + l); + while (!TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) && + LLDP_TLV_NAME (pdu_end) != lldp_tlv_get_code (tlv)) + { + switch (lldp_tlv_get_code (tlv)) + { +#define F(num, type, str) \ + case LLDP_TLV_NAME (type): \ + /* ignore optional TLV */ \ + break; + foreach_lldp_optional_tlv_type (F); +#undef F + default: + return LLDP_ERROR_BAD_TLV; + } + tlv = (lldp_tlv_t *) ((u8 *) tlv + STRUCT_SIZE_OF (lldp_tlv_t, head) + + lldp_tlv_get_length (tlv)); + } + /* last tlv is pdu_end */ + if (TLV_VIOLATES_PKT_BOUNDARY (pkt, tlv) || + LLDP_TLV_NAME (pdu_end) != lldp_tlv_get_code (tlv) || + 0 != lldp_tlv_get_length (tlv)) + { + return LLDP_ERROR_BAD_TLV; + } + lldp_rpc_update_peer (hw_if_index, chid, chid_len, chid_subtype, portid, + portid_len, portid_subtype, ttl); + return LLDP_ERROR_NONE; +} + +lldp_intf_t * +lldp_get_intf (lldp_main_t * lm, u32 hw_if_index) +{ + uword *p = hash_get (lm->intf_by_hw_if_index, hw_if_index); + + if (p) + { + return pool_elt_at_index (lm->intfs, p[0]); + } + return NULL; +} + +lldp_intf_t * +lldp_create_intf (lldp_main_t * lm, u32 hw_if_index) +{ + + uword *p; + lldp_intf_t *n; + p = hash_get (lm->intf_by_hw_if_index, hw_if_index); + + if (p == 0) + { + pool_get (lm->intfs, n); + clib_memset (n, 0, sizeof (*n)); + n->hw_if_index = hw_if_index; + hash_set (lm->intf_by_hw_if_index, n->hw_if_index, n - lm->intfs); + } + else + { + n = pool_elt_at_index (lm->intfs, p[0]); + } + return n; +} + +/* + * lldp input routine + */ +lldp_error_t +lldp_input (vlib_main_t * vm, vlib_buffer_t * b0, u32 bi0) +{ + lldp_main_t *lm = &lldp_main; + lldp_error_t e; + + /* find our interface */ + vnet_sw_interface_t *sw_interface = vnet_get_sw_interface (lm->vnet_main, + vnet_buffer + (b0)->sw_if_index + [VLIB_RX]); + lldp_intf_t *n = lldp_get_intf (lm, sw_interface->hw_if_index); + + if (!n) + { + /* lldp disabled on this interface, we're done */ + return LLDP_ERROR_DISABLED; + } + + /* Actually scan the packet */ + e = lldp_packet_scan (sw_interface->hw_if_index, + vlib_buffer_get_current (b0)); + + return e; +} + +/* + * setup function + */ +static clib_error_t * +lldp_init (vlib_main_t * vm) +{ + clib_error_t *error; + lldp_main_t *lm = &lldp_main; + + if ((error = vlib_call_init_function (vm, lldp_template_init))) + return error; + + lm->vlib_main = vm; + lm->vnet_main = vnet_get_main (); + lm->msg_tx_hold = 4; /* default value per IEEE 802.1AB-2009 */ + lm->msg_tx_interval = 30; /* default value per IEEE 802.1AB-2009 */ + + return 0; +} + +VLIB_INIT_FUNCTION (lldp_init); + +/* + * fd.io coding-style-patch-verification: ON + * + * Local Variables: + * eval: (c-set-style "gnu") + * End: + */ |