/*** 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 . ***/ #include #include "sd-lldp.h" #include "alloc-util.h" #include "fd-util.h" #include "fileio.h" #include "hashmap.h" #include "lldp-internal.h" #include "lldp-network.h" #include "lldp-tlv.h" #include "prioq.h" #include "siphash24.h" #include "string-util.h" struct sd_lldp { int ifindex; int fd; sd_event *event; int64_t event_priority; sd_event_source *event_source; Prioq *by_expiry; Hashmap *neighbour_mib; sd_lldp_callback_t callback; void *userdata; }; static void chassis_id_hash_func(const void *p, struct siphash *state) { const lldp_chassis_id *id = p; assert(id); assert(id->data); siphash24_compress(&id->length, sizeof(id->length), state); siphash24_compress(id->data, id->length, state); } 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 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_mib_delete_objects(lldp); r = lldp_mib_add_objects(lldp->by_expiry, lldp->neighbour_mib, tlv); if (r < 0) goto out; if (lldp->callback) lldp->callback(lldp, SD_LLDP_EVENT_UPDATE_INFO, lldp->userdata); log_lldp("Packet added. MIB size: %d , PQ size: %d", hashmap_size(lldp->neighbour_mib), prioq_size(lldp->by_expiry)); out: if (r < 0) log_lldp("Receive frame failed: %s", strerror(-r)); return 0; } /* 10.3.2 LLDPDU validation: rxProcessFrame() */ int lldp_handle_packet(tlv_packet *tlv, uint16_t length) { bool system_description = false, system_name = false, chassis_id = false; bool port_id = false, ttl = false, end = false; uint16_t type, len, i, l, t; uint8_t *p, *q; sd_lldp *lldp; int r; assert(tlv); assert(length > 0); lldp = tlv->userdata; 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 must be length 0 (not %d). Dropping.", len); goto out; } end = true; break; } else if (type >=_LLDP_TYPE_MAX) { log_lldp("TLV type: %d not recognized. Dropping.", type); goto out; } /* skip type and length 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."); goto out; } } switch(type) { case LLDP_TYPE_CHASSIS_ID: if (len < 2) { log_lldp("Received malformed Chassis ID TLV length: %d. Dropping.", len); goto out; } if (chassis_id) { log_lldp("Duplicate Chassis ID TLV found. Dropping."); 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); goto out; } chassis_id = true; break; case LLDP_TYPE_PORT_ID: if (len < 2) { log_lldp("Received malformed Port ID TLV length: %d. Dropping.", len); goto out; } if (port_id) { log_lldp("Duplicate Port ID TLV found. Dropping."); 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); goto out; } port_id = true; break; case LLDP_TYPE_TTL: if(len != 2) { log_lldp("Received invalid TTL TLV lenth: %d. Dropping.", len); goto out; } if (ttl) { log_lldp("Duplicate TTL TLV found. Dropping."); goto out; } ttl = true; break; case LLDP_TYPE_SYSTEM_NAME: /* According to RFC 1035 the length of a FQDN is limited to 255 characters */ if (len > 255) { log_lldp("Received invalid system name length: %d. Dropping.", len); goto out; } if (system_name) { log_lldp("Duplicate system name found. Dropping."); goto out; } system_name = true; break; case LLDP_TYPE_SYSTEM_DESCRIPTION: /* 0 <= n <= 255 octets */ if (len > 255) { log_lldp("Received invalid system description length: %d. Dropping.", len); goto out; } if (system_description) { log_lldp("Duplicate system description found. Dropping."); goto out; } system_description = true; break; default: if (len == 0) { log_lldp("TLV type: %d length 0 received. Dropping.", type); goto out; } break; } } if(!chassis_id || !port_id || !ttl || !end) { log_lldp("One or more mandatory TLV missing. Dropping."); goto out; } r = tlv_packet_parse_pdu(tlv, length); if (r < 0) { log_lldp("Failed to parse the TLV. Dropping."); goto out; } return lldp_receive_frame(lldp, tlv); out: sd_lldp_packet_unref(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; } /* 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_or_monotonic()); if (p->until > t) break; lldp_neighbour_port_remove_and_free(p); } } 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 fail; 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 = sd_lldp_packet_read_chassis_id(p->packet, &type, &mac, &length); 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) { r = -ENOMEM; goto fail; } r = sd_lldp_packet_read_port_id(p->packet, &type, &port_id, &length); if (r < 0) continue; if (type != LLDP_PORT_SUBTYPE_MAC_ADDRESS) { k = strndup((char *) port_id, length -1); if (!k) { r = -ENOMEM; goto fail; } 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) { r = -ENOMEM; goto fail; } free(s); s = k; time = now(clock_boottime_or_monotonic()); /* Don't write expired packets */ if (time - p->until <= 0) continue; sprintf(buf, "'_TTL="USEC_FMT"' ", p->until); k = strappend(s, buf); if (!k) { r = -ENOMEM; goto fail; } free(s); s = k; r = sd_lldp_packet_read_system_name(p->packet, &k, &length); if (r < 0) k = strappend(s, "'_NAME=N/A' "); else { t = strndup(k, length); if (!t) { r = -ENOMEM; goto fail; } k = strjoin(s, "'_NAME=", t, "' ", NULL); free(t); } if (!k) { r = -ENOMEM; goto fail; } free(s); s = k; (void) sd_lldp_packet_read_system_capability(p->packet, &data); sprintf(buf, "'_CAP=%x'", data); k = strappend(s, buf); if (!k) { r = -ENOMEM; goto fail; } free(s); s = k; fprintf(f, "%s\n", s); } } r = fflush_and_check(f); if (r < 0) goto fail; if (rename(temp_path, lldp_file) < 0) { r = -errno; goto fail; } return 0; fail: if (temp_path) (void) unlink(temp_path); return log_error_errno(r, "Failed to save lldp data %s: %m", lldp_file); } int sd_lldp_start(sd_lldp *lldp) { int r; assert_return(lldp, -EINVAL); if (lldp->fd >= 0) return 0; assert(!lldp->event_source); lldp->fd = lldp_network_bind_raw_socket(lldp->ifindex); if (lldp->fd < 0) return lldp->fd; if (lldp->event) { r = sd_event_add_io(lldp->event, &lldp->event_source, lldp->fd, EPOLLIN, lldp_receive_packet, lldp); if (r < 0) goto fail; r = sd_event_source_set_priority(lldp->event_source, lldp->event_priority); if (r < 0) goto fail; (void) sd_event_source_set_description(lldp->event_source, "lldp"); } return 1; fail: lldp->event_source = sd_event_source_unref(lldp->event_source); lldp->fd = safe_close(lldp->fd); return r; } int sd_lldp_stop(sd_lldp *lldp) { assert_return(lldp, -EINVAL); if (lldp->fd < 0) return 0; lldp->event_source = sd_event_source_unref(lldp->event_source); lldp->fd = safe_close(lldp->fd); lldp_mib_objects_flush(lldp); return 1; } int sd_lldp_attach_event(sd_lldp *lldp, sd_event *event, int64_t priority) { int r; assert_return(lldp, -EINVAL); assert_return(lldp->fd < 0, -EBUSY); assert_return(!lldp->event, -EBUSY); if (event) lldp->event = sd_event_ref(event); else { r = sd_event_default(&lldp->event); if (r < 0) return r; } lldp->event_priority = priority; return 0; } int sd_lldp_detach_event(sd_lldp *lldp) { assert_return(lldp, -EINVAL); assert_return(lldp->fd < 0, -EBUSY); lldp->event = sd_event_unref(lldp->event); return 0; } int sd_lldp_set_callback(sd_lldp *lldp, sd_lldp_callback_t cb, void *userdata) { assert_return(lldp, -EINVAL); lldp->callback = cb; lldp->userdata = userdata; return 0; } sd_lldp* sd_lldp_unref(sd_lldp *lldp) { if (!lldp) return NULL; /* Drop all packets */ lldp_mib_objects_flush(lldp); hashmap_free(lldp->neighbour_mib); prioq_free(lldp->by_expiry); sd_event_source_unref(lldp->event_source); sd_event_unref(lldp->event); safe_close(lldp->fd); free(lldp); return NULL; } int sd_lldp_new(int ifindex, sd_lldp **ret) { _cleanup_(sd_lldp_unrefp) sd_lldp *lldp = NULL; int r; assert_return(ret, -EINVAL); assert_return(ifindex > 0, -EINVAL); lldp = new0(sd_lldp, 1); if (!lldp) return -ENOMEM; lldp->fd = -1; lldp->ifindex = ifindex; 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; *ret = lldp; lldp = NULL; return 0; } int sd_lldp_get_packets(sd_lldp *lldp, sd_lldp_packet ***tlvs) { lldp_neighbour_port *p; lldp_chassis *c; Iterator iter; unsigned count = 0, i; assert_return(lldp, -EINVAL); assert_return(tlvs, -EINVAL); HASHMAP_FOREACH(c, lldp->neighbour_mib, iter) { LIST_FOREACH(port, p, c->ports) count++; } if (!count) { *tlvs = NULL; return 0; } *tlvs = new(sd_lldp_packet *, count); if (!*tlvs) return -ENOMEM; i = 0; HASHMAP_FOREACH(c, lldp->neighbour_mib, iter) { LIST_FOREACH(port, p, c->ports) (*tlvs)[i++] = sd_lldp_packet_ref(p->packet); } return count; }