/* * 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: */