/*-*- 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 <arpa/inet.h> #include "siphash24.h" #include "hashmap.h" #include "lldp-tlv.h" #include "lldp-port.h" #include "sd-lldp.h" #include "prioq.h" #include "lldp-internal.h" #include "lldp-util.h" typedef enum LLDPAgentRXState { LLDP_AGENT_RX_WAIT_PORT_OPERATIONAL = 4, LLDP_AGENT_RX_DELETE_AGED_INFO, LLDP_AGENT_RX_LLDP_INITIALIZE, LLDP_AGENT_RX_WAIT_FOR_FRAME, LLDP_AGENT_RX_RX_FRAME, LLDP_AGENT_RX_DELETE_INFO, LLDP_AGENT_RX_UPDATE_INFO, _LLDP_AGENT_RX_STATE_MAX, _LLDP_AGENT_RX_INVALID = -1, } LLDPAgentRXState; /* Section 10.5.2.2 Reception counters */ struct lldp_agent_statistics { uint64_t stats_ageouts_total; uint64_t stats_frames_discarded_total; uint64_t stats_frames_in_errors_total; uint64_t stats_frames_in_total; uint64_t stats_tlvs_discarded_total; uint64_t stats_tlvs_unrecognized_total; }; struct sd_lldp { lldp_port *port; Prioq *by_expiry; Hashmap *neighbour_mib; sd_lldp_cb_t cb; void *userdata; LLDPAgentRXState rx_state; lldp_agent_statistics statistics; }; static unsigned long chassis_id_hash_func(const void *p, const uint8_t hash_key[HASH_KEY_SIZE]) { uint64_t u; const lldp_chassis_id *id = p; assert(id); siphash24((uint8_t *) &u, id->data, id->length, hash_key); return (unsigned long) u; } static int chassis_id_compare_func(const void *_a, const void *_b) { const lldp_chassis_id *a, *b; a = _a; b = _b; assert(!a->length || a->data); assert(!b->length || b->data); if (a->type != b->type) return -1; if (a->length != b->length) return a->length < b->length ? -1 : 1; return memcmp(a->data, b->data, a->length); } static const struct hash_ops chassis_id_hash_ops = { .hash = chassis_id_hash_func, .compare = chassis_id_compare_func }; static void lldp_mib_delete_objects(sd_lldp *lldp); static void lldp_set_state(sd_lldp *lldp, LLDPAgentRXState state); static void lldp_run_state_machine(sd_lldp *ll); static int lldp_receive_frame(sd_lldp *lldp, tlv_packet *tlv) { int r; assert(lldp); assert(tlv); /* Remove expired packets */ if (prioq_size(lldp->by_expiry) > 0) { lldp_set_state(lldp, LLDP_AGENT_RX_DELETE_INFO); lldp_mib_delete_objects(lldp); } r = lldp_mib_add_objects(lldp->by_expiry, lldp->neighbour_mib, tlv); if (r < 0) goto out; lldp_set_state(lldp, LLDP_AGENT_RX_UPDATE_INFO); log_lldp("Packet added. MIB size: %d , PQ size: %d", hashmap_size(lldp->neighbour_mib), prioq_size(lldp->by_expiry)); lldp->statistics.stats_frames_in_total ++; return 0; out: if (r < 0) log_lldp("Receive frame failed: %s", strerror(-r)); lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_FOR_FRAME); return 0; } /* 10.3.2 LLDPDU validation: rxProcessFrame() */ int lldp_handle_packet(tlv_packet *tlv, uint16_t length) { uint16_t type, len, i, l, t; bool chassis_id = false; bool malformed = false; bool port_id = false; bool ttl = false; bool end = false; lldp_port *port; uint8_t *p, *q; sd_lldp *lldp; int r; assert(tlv); assert(length > 0); port = (lldp_port *) tlv->userdata; lldp = (sd_lldp *) port->userdata; if (lldp->port->status == LLDP_PORT_STATUS_DISABLED) { log_lldp("Port is disabled : %s . Dropping ...", lldp->port->ifname); goto out; } lldp_set_state(lldp, LLDP_AGENT_RX_RX_FRAME); p = tlv->pdu; p += sizeof(struct ether_header); for (i = 1, l = 0; l <= length; i++) { memcpy(&t, p, sizeof(uint16_t)); type = ntohs(t) >> 9; len = ntohs(t) & 0x01ff; if (type == LLDP_TYPE_END) { if (len != 0) { log_lldp("TLV type end is not length 0. Length:%d received . Dropping ...", len); malformed = true; goto out; } end = true; break; } else if (type >=_LLDP_TYPE_MAX) { log_lldp("TLV type not recognized %d . Dropping ...", type); malformed = true; goto out; } /* skip type and lengh encoding */ p += 2; q = p; p += len; l += (len + 2); if (i <= 3) { if (i != type) { log_lldp("TLV missing or out of order. Dropping ..."); malformed = true; goto out; } } switch(type) { case LLDP_TYPE_CHASSIS_ID: if (len < 2) { log_lldp("Received malformed Chassis ID TLV len = %d. Dropping", len); malformed = true; goto out; } if (chassis_id) { log_lldp("Duplicate Chassis ID TLV found. Dropping ..."); malformed = true; goto out; } /* Look what subtype it has */ if (*q == LLDP_CHASSIS_SUBTYPE_RESERVED || *q > LLDP_CHASSIS_SUBTYPE_LOCALLY_ASSIGNED) { log_lldp("Unknown subtype: %d found in Chassis ID TLV . Dropping ...", *q); malformed = true; goto out; } chassis_id = true; break; case LLDP_TYPE_PORT_ID: if (len < 2) { log_lldp("Received malformed Port ID TLV len = %d. Dropping", len); malformed = true; goto out; } if (port_id) { log_lldp("Duplicate Port ID TLV found. Dropping ..."); malformed = true; goto out; } /* Look what subtype it has */ if (*q == LLDP_PORT_SUBTYPE_RESERVED || *q > LLDP_PORT_SUBTYPE_LOCALLY_ASSIGNED) { log_lldp("Unknown subtype: %d found in Port ID TLV . Dropping ...", *q); malformed = true; goto out; } port_id = true; break; case LLDP_TYPE_TTL: if(len != 2) { log_lldp( "Received invalid lenth: %d TTL TLV. Dropping ...", len); malformed = true; goto out; } if (ttl) { log_lldp("Duplicate TTL TLV found. Dropping ..."); malformed = true; goto out; } ttl = true; break; default: if (len == 0) { log_lldp("TLV type = %d's, length 0 received . Dropping ...", type); malformed = true; goto out; } break; } } if(!chassis_id || !port_id || !ttl || !end) { log_lldp( "One or more mandotory TLV missing . Dropping ..."); malformed = true; goto out; } r = tlv_packet_parse_pdu(tlv, length); if (r < 0) { log_lldp( "Failed to parse the TLV. Dropping ..."); malformed = true; goto out; } return lldp_receive_frame(lldp, tlv); out: lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_FOR_FRAME); if (malformed) { lldp->statistics.stats_frames_discarded_total ++; lldp->statistics.stats_frames_in_errors_total ++; } tlv_packet_free(tlv); return 0; } static int ttl_expiry_item_prioq_compare_func(const void *a, const void *b) { const lldp_neighbour_port *p = a, *q = b; if (p->until < q->until) return -1; if (p->until > q->until) return 1; return 0; } static void lldp_set_state(sd_lldp *lldp, LLDPAgentRXState state) { assert(lldp); assert(state < _LLDP_AGENT_RX_STATE_MAX); lldp->rx_state = state; lldp_run_state_machine(lldp); } static void lldp_run_state_machine(sd_lldp *lldp) { if (lldp->rx_state == LLDP_AGENT_RX_UPDATE_INFO) if (lldp->cb) lldp->cb(lldp, LLDP_AGENT_RX_UPDATE_INFO, lldp->userdata); } /* 10.5.5.2.1 mibDeleteObjects () * The mibDeleteObjects () procedure deletes all information in the LLDP remote * systems MIB associated with the MSAP identifier if an LLDPDU is received with * an rxTTL value of zero (see 10.3.2) or the timing counter rxInfoTTL expires. */ static void lldp_mib_delete_objects(sd_lldp *lldp) { lldp_neighbour_port *p; usec_t t = 0; /* Remove all entries that are past their TTL */ for (;;) { if (prioq_size(lldp->by_expiry) <= 0) break; p = prioq_peek(lldp->by_expiry); if (!p) break; if (t <= 0) t = now(CLOCK_BOOTTIME); if (p->until > t) break; lldp_neighbour_port_remove_and_free(p); lldp->statistics.stats_ageouts_total ++; } } static void lldp_mib_objects_flush(sd_lldp *lldp) { lldp_neighbour_port *p, *q; lldp_chassis *c; assert(lldp); assert(lldp->neighbour_mib); assert(lldp->by_expiry); /* Drop all packets */ while ((c = hashmap_steal_first(lldp->neighbour_mib))) { LIST_FOREACH_SAFE(port, p, q, c->ports) { lldp_neighbour_port_remove_and_free(p); } } assert(hashmap_size(lldp->neighbour_mib) == 0); assert(prioq_size(lldp->by_expiry) == 0); } int sd_lldp_save(sd_lldp *lldp, const char *lldp_file) { _cleanup_free_ char *temp_path = NULL; _cleanup_fclose_ FILE *f = NULL; uint8_t *mac, *port_id, type; lldp_neighbour_port *p; uint16_t data = 0, length = 0; char buf[LINE_MAX]; lldp_chassis *c; usec_t time; Iterator i; int r; assert(lldp); assert(lldp_file); r = fopen_temporary(lldp_file, &f, &temp_path); if (r < 0) goto finish; fchmod(fileno(f), 0644); HASHMAP_FOREACH(c, lldp->neighbour_mib, i) { LIST_FOREACH(port, p, c->ports) { _cleanup_free_ char *s = NULL; char *k, *t; r = lldp_read_chassis_id(p->packet, &type, &length, &mac); if (r < 0) continue; sprintf(buf, "'_Chassis=%02x:%02x:%02x:%02x:%02x:%02x' '_CType=%d' ", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type); s = strdup(buf); if (!s) return -ENOMEM; r = lldp_read_port_id(p->packet, &type, &length, &port_id); if (r < 0) continue; if (type != LLDP_PORT_SUBTYPE_MAC_ADDRESS) { k = strndup((char *) port_id, length -1); if (!k) return -ENOMEM; sprintf(buf, "'_Port=%s' '_PType=%d' ", k , type); free(k); } else { mac = port_id; sprintf(buf, "'_Port=%02x:%02x:%02x:%02x:%02x:%02x' '_PType=%d' ", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5], type); } k = strappend(s, buf); if (!k) return -ENOMEM; free(s); s = k; time = now(CLOCK_BOOTTIME); /* Don't write expired packets */ if (time - p->until <= 0) continue; sprintf(buf, "'_TTL="USEC_FMT"' ", p->until); k = strappend(s, buf); if (!k) return -ENOMEM; free(s); s = k; r = lldp_read_system_name(p->packet, &length, &k); if (r < 0) k = strappend(s, "'_NAME=N/A' "); else { t = strndup(k, length); if (!t) return -ENOMEM; k = strjoin(s, "'_NAME=", t, "' ", NULL); free(t); } if (!k) return -ENOMEM; free(s); s = k; (void) lldp_read_system_capability(p->packet, &data); sprintf(buf, "'_CAP=%x'", data); k = strappend(s, buf); if (!k) return -ENOMEM; free(s); s = k; fprintf(f, "%s\n", s); } } r = 0; fflush(f); if (ferror(f) || rename(temp_path, lldp_file) < 0) { r = -errno; unlink(lldp_file); unlink(temp_path); } finish: if (r < 0) log_error("Failed to save lldp data %s: %s", lldp_file, strerror(-r)); return r; } int sd_lldp_start(sd_lldp *lldp) { int r; assert_return(lldp, -EINVAL); assert_return(lldp->port, -EINVAL); lldp->port->status = LLDP_PORT_STATUS_ENABLED; lldp_set_state(lldp, LLDP_AGENT_RX_LLDP_INITIALIZE); r = lldp_port_start(lldp->port); if (r < 0) { log_lldp("Failed to start Port : %s , %s", lldp->port->ifname, strerror(-r)); lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_PORT_OPERATIONAL); return r; } lldp_set_state(lldp, LLDP_AGENT_RX_WAIT_FOR_FRAME); return 0; } int sd_lldp_stop(sd_lldp *lldp) { int r; assert_return(lldp, -EINVAL); assert_return(lldp->port, -EINVAL); lldp->port->status = LLDP_PORT_STATUS_DISABLED; r = lldp_port_stop(lldp->port); if (r < 0) return r; lldp_mib_objects_flush(lldp); return 0; } int sd_lldp_attach_event(sd_lldp *lldp, sd_event *event, int priority) { int r; assert_return(lldp, -EINVAL); assert_return(!lldp->port->event, -EBUSY); if (event) lldp->port->event = sd_event_ref(event); else { r = sd_event_default(&lldp->port->event); if (r < 0) return r; } lldp->port->event_priority = priority; return 0; } int sd_lldp_detach_event(sd_lldp *lldp) { assert_return(lldp, -EINVAL); lldp->port->event = sd_event_unref(lldp->port->event); return 0; } int sd_lldp_set_callback(sd_lldp *lldp, sd_lldp_cb_t cb, void *userdata) { assert_return(lldp, -EINVAL); lldp->cb = cb; lldp->userdata = userdata; return 0; } void sd_lldp_free(sd_lldp *lldp) { if (!lldp) return; /* Drop all packets */ lldp_mib_objects_flush(lldp); lldp_port_free(lldp->port); hashmap_free(lldp->neighbour_mib); prioq_free(lldp->by_expiry); free(lldp); } int sd_lldp_new(int ifindex, const char *ifname, const struct ether_addr *mac, sd_lldp **ret) { _cleanup_lldp_free_ sd_lldp *lldp = NULL; int r; assert_return(ret, -EINVAL); assert_return(ifindex > 0, -EINVAL); assert_return(ifname, -EINVAL); assert_return(mac, -EINVAL); lldp = new0(sd_lldp, 1); if (!lldp) return -ENOMEM; r = lldp_port_new(ifindex, ifname, mac, lldp, &lldp->port); if (r < 0) return r; lldp->neighbour_mib = hashmap_new(&chassis_id_hash_ops); if (!lldp->neighbour_mib) return -ENOMEM; r = prioq_ensure_allocated(&lldp->by_expiry, ttl_expiry_item_prioq_compare_func); if (r < 0) return r; lldp->rx_state = LLDP_AGENT_RX_WAIT_PORT_OPERATIONAL; *ret = lldp; lldp = NULL; return 0; }