/* * Label Manager for FRR * * Copyright (C) 2017 by Bingen Eguzkitza, * Volta Networks Inc. * * This file is part of FreeRangeRouting (FRR) * * FRR is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License as published by the * Free Software Foundation; either version 2, or (at your option) any * later version. * * FRR 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 * General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; see the file COPYING; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include "lib/log.h" #include "lib/memory.h" #include "lib/mpls.h" #include "lib/network.h" #include "lib/stream.h" #include "lib/zclient.h" #include "lib/libfrr.h" //#include "zebra/zserv.h" #include "zebra/zebra_router.h" #include "zebra/label_manager.h" #include "zebra/zebra_errors.h" #define CONNECTION_DELAY 5 struct label_manager lbl_mgr; extern struct zebra_privs_t zserv_privs; DEFINE_MGROUP(LBL_MGR, "Label Manager"); DEFINE_MTYPE_STATIC(LBL_MGR, LM_CHUNK, "Label Manager Chunk"); /* In case this zebra daemon is not acting as label manager, * it will be a proxy to relay messages to external label manager * This zclient thus is to connect to it */ static struct stream *obuf; static struct zclient *zclient; bool lm_is_external; static void delete_label_chunk(void *val) { XFREE(MTYPE_LM_CHUNK, val); } static int relay_response_back(void) { int ret = 0; struct stream *src, *dst; uint16_t size = 0; uint8_t marker; uint8_t version; vrf_id_t vrf_id; uint16_t resp_cmd; uint8_t proto; const char *proto_str; unsigned short instance; struct zserv *zserv; /* sanity */ if (!zclient || zclient->sock < 0) return -1; /* input buffer with msg from label manager */ src = zclient->ibuf; stream_reset(src); /* parse header */ ret = zclient_read_header(src, zclient->sock, &size, &marker, &version, &vrf_id, &resp_cmd); if (ret < 0) { if (errno != EAGAIN) flog_err(EC_ZEBRA_LM_RESPONSE, "Error reading Label Manager response: %s", strerror(errno)); return -1; } /* do not relay a msg that has nothing to do with LM */ switch (resp_cmd) { case ZEBRA_LABEL_MANAGER_CONNECT: case ZEBRA_LABEL_MANAGER_CONNECT_ASYNC: /* should not be seen */ case ZEBRA_GET_LABEL_CHUNK: case ZEBRA_RELEASE_LABEL_CHUNK: break; default: zlog_debug("Not relaying '%s' response (size %d) from LM", zserv_command_string(resp_cmd), size); return -1; } zlog_debug("Received '%s' response (size %d) from LM", zserv_command_string(resp_cmd), size); if (size == 0) return -1; /* Get the 'proto' field of the message */ proto = stream_getc(src); /* Get the 'instance' field of the message */ instance = stream_getw(src); proto_str = zebra_route_string(proto); /* lookup the client to relay the msg to */ zserv = zserv_find_client(proto, instance); if (!zserv) { flog_err( EC_ZEBRA_LM_NO_SUCH_CLIENT, "Error relaying LM response: can't find client %s, instance %u", proto_str, instance); return -1; } zlog_debug("Found client to relay LM response to client %s instance %u", proto_str, instance); /* copy msg into output buffer */ dst = obuf; stream_copy(dst, src); /* send response back */ ret = writen(zserv->sock, dst->data, stream_get_endp(dst)); if (ret <= 0) { flog_err(EC_ZEBRA_LM_RELAY_FAILED, "Error relaying LM response to %s instance %u: %s", proto_str, instance, strerror(errno)); return -1; } zlog_debug("Relayed LM response (%d bytes) to %s instance %u", ret, proto_str, instance); return 0; } static int lm_zclient_read(struct thread *t) { int ret; zclient->t_read = NULL; /* read response and send it back */ ret = relay_response_back(); /* re-arm read */ thread_add_read(zclient->master, lm_zclient_read, NULL, zclient->sock, &zclient->t_read); return ret; } static int reply_error(int cmd, struct zserv *zserv, vrf_id_t vrf_id) { int ret; struct stream *s; s = stream_new(ZEBRA_MAX_PACKET_SIZ); zclient_create_header(s, cmd, vrf_id); /* proto */ stream_putc(s, zserv->proto); /* instance */ stream_putw(s, zserv->instance); /* result */ stream_putc(s, 1); /* Write packet size. */ stream_putw_at(s, 0, stream_get_endp(s)); ret = writen(zserv->sock, s->data, stream_get_endp(s)); stream_free(s); return ret; } /** * Receive a request to get or release a label chunk and forward it to external * label manager. * * It's called from zserv in case it's not an actual label manager, but just a * proxy. * * @param cmd Type of request (connect, get or release) * @param zserv * @return 0 on success, -1 otherwise */ int zread_relay_label_manager_request(int cmd, struct zserv *zserv, struct stream *msg, vrf_id_t vrf_id) { struct stream *dst; int ret = 0; uint8_t proto; const char *proto_str; unsigned short instance; if (zclient->sock < 0) { flog_err(EC_ZEBRA_LM_NO_SOCKET, "Unable to relay LM request: no socket"); reply_error(cmd, zserv, vrf_id); return -1; } /* peek msg to get proto and instance id. This zebra, which acts as * a proxy needs to have such values for each client in order to * relay responses back to it. */ /* Get the 'proto' field of incoming msg */ proto = stream_getc(msg); /* Get the 'instance' field of incoming msg */ instance = stream_getw(msg); /* stringify proto */ proto_str = zebra_route_string(proto); /* check & set client proto if unset */ if (zserv->proto && zserv->proto != proto) { flog_warn(EC_ZEBRAING_LM_PROTO_MISMATCH, "Client proto(%u) != msg proto(%u)", zserv->proto, proto); return -1; } /* check & set client instance if unset */ if (zserv->instance && zserv->instance != instance) { flog_err(EC_ZEBRA_LM_BAD_INSTANCE, "Client instance(%u) != msg instance(%u)", zserv->instance, instance); return -1; } /* recall proto and instance */ zserv->instance = instance; zserv->proto = proto; /* in case there's any incoming message enqueued, read and forward it */ if (zserv->is_synchronous) while (ret == 0) ret = relay_response_back(); /* get the msg buffer used toward the 'master' Label Manager */ dst = zclient->obuf; /* copy the message */ stream_copy(dst, msg); /* Send request to external label manager */ ret = writen(zclient->sock, dst->data, stream_get_endp(dst)); if (ret <= 0) { flog_err(EC_ZEBRA_LM_RELAY_FAILED, "Error relaying LM request from %s instance %u: %s", proto_str, instance, strerror(errno)); reply_error(cmd, zserv, vrf_id); return -1; } zlog_debug("Relayed LM request (%d bytes) from %s instance %u", ret, proto_str, instance); /* Release label chunk has no response */ if (cmd == ZEBRA_RELEASE_LABEL_CHUNK) return 0; /* make sure we listen to the response */ if (!zclient->t_read) thread_add_read(zclient->master, lm_zclient_read, NULL, zclient->sock, &zclient->t_read); return 0; } static int lm_zclient_connect(struct thread *t) { zclient->t_connect = NULL; if (zclient->sock >= 0) return 0; if (zclient_socket_connect(zclient) < 0) { flog_err(EC_ZEBRA_LM_CLIENT_CONNECTION_FAILED, "Error connecting synchronous zclient!"); thread_add_timer(zrouter.master, lm_zclient_connect, zclient, CONNECTION_DELAY, &zclient->t_connect); return -1; } /* make socket non-blocking */ (void)set_nonblocking(zclient->sock); return 0; } /** * Function to initialize zclient in case this is not an actual * label manager, but just a proxy to an external one. * * @param lm_zserv_path Path to zserv socket of external label manager */ static void lm_zclient_init(char *lm_zserv_path) { if (lm_zserv_path) frr_zclient_addr(&zclient_addr, &zclient_addr_len, lm_zserv_path); /* Set default values. */ zclient = zclient_new(zrouter.master, &zclient_options_default); zclient->privs = &zserv_privs; zclient->sock = -1; zclient->t_connect = NULL; lm_zclient_connect(NULL); } /** * Release label chunks from a client. * * Called on client disconnection or reconnection. It only releases chunks * with empty keep value. * * @param proto Daemon protocol of client, to identify the owner * @param instance Instance, to identify the owner * @return Number of chunks released */ int release_daemon_label_chunks(struct zserv *client) { uint8_t proto = client->proto; uint16_t instance = client->instance; struct listnode *node; struct label_manager_chunk *lmc; int count = 0; int ret; for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { if (lmc->proto == proto && lmc->instance == instance && lmc->keep == 0) { ret = release_label_chunk(lmc->proto, lmc->instance, lmc->start, lmc->end); if (ret == 0) count++; } } zlog_debug("%s: Released %d label chunks", __func__, count); return count; } /** * Init label manager (or proxy to an external one) */ void label_manager_init(char *lm_zserv_path) { /* this is an actual label manager */ if (!lm_zserv_path) { zlog_debug("Initializing internal label manager"); lm_is_external = false; lbl_mgr.lc_list = list_new(); lbl_mgr.lc_list->del = delete_label_chunk; } else { /* it's acting just as a proxy */ zlog_debug("Initializing external label manager at %s", lm_zserv_path); lm_is_external = true; lm_zclient_init(lm_zserv_path); } obuf = stream_new(ZEBRA_MAX_PACKET_SIZ); hook_register(zserv_client_close, release_daemon_label_chunks); } /* alloc and fill a label chunk */ static struct label_manager_chunk * create_label_chunk(uint8_t proto, unsigned short instance, uint8_t keep, uint32_t start, uint32_t end) { /* alloc chunk, fill it and return it */ struct label_manager_chunk *lmc = XCALLOC(MTYPE_LM_CHUNK, sizeof(struct label_manager_chunk)); lmc->start = start; lmc->end = end; lmc->proto = proto; lmc->instance = instance; lmc->keep = keep; return lmc; } /* attempt to get a specific label chunk */ struct label_manager_chunk * assign_specific_label_chunk(uint8_t proto, unsigned short instance, uint8_t keep, uint32_t size, uint32_t base) { struct label_manager_chunk *lmc; struct listnode *node, *next = NULL; struct listnode *first_node = NULL; struct listnode *last_node = NULL; struct listnode *insert_node = NULL; /* precompute last label from base and size */ uint32_t end = base + size - 1; /* sanities */ if ((base < MPLS_LABEL_UNRESERVED_MIN) || (end > MPLS_LABEL_UNRESERVED_MAX)) { zlog_err("Invalid LM request arguments: base: %u, size: %u", base, size); return NULL; } /* Scan the existing chunks to see if the requested range of labels * falls inside any of such chunks */ for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { /* skip chunks for labels < base */ if (base > lmc->end) continue; /* requested range is not covered by any existing, free chunk. * Therefore, need to insert a chunk */ if ((end < lmc->start) && !first_node) { insert_node = node; break; } if (!first_node) first_node = node; /* if chunk is used, cannot honor request */ if (lmc->proto != NO_PROTO) return NULL; if (end < lmc->end) { last_node = node; break; } } /* insert chunk between existing chunks */ if (insert_node) { lmc = create_label_chunk(proto, instance, keep, base, end); listnode_add_before(lbl_mgr.lc_list, insert_node, lmc); return lmc; } if (first_node) { /* get node past the last one, if there */ if (last_node) last_node = listnextnode(last_node); /* delete node coming after the above chunk whose labels are * included in the previous one */ for (node = first_node; node && (node != last_node); node = next) { next = listnextnode(node); list_delete_node(lbl_mgr.lc_list, node); } lmc = create_label_chunk(proto, instance, keep, base, end); if (last_node) listnode_add_before(lbl_mgr.lc_list, last_node, lmc); else listnode_add(lbl_mgr.lc_list, lmc); return lmc; } else { /* create a new chunk past all the existing ones and link at * tail */ lmc = create_label_chunk(proto, instance, keep, base, end); listnode_add(lbl_mgr.lc_list, lmc); return lmc; } } /** * Core function, assigns label chunks * * It first searches through the list to check if there's one available * (previously released). Otherwise it creates and assigns a new one * * @param proto Daemon protocol of client, to identify the owner * @param instance Instance, to identify the owner * @param keep If set, avoid garbage collection * @param size Size of the label chunk * @param base Desired starting label of the chunk; if MPLS_LABEL_BASE_ANY it does not apply * @return Pointer to the assigned label chunk, or NULL if the request could not be satisfied */ struct label_manager_chunk *assign_label_chunk(uint8_t proto, unsigned short instance, uint8_t keep, uint32_t size, uint32_t base) { struct label_manager_chunk *lmc; struct listnode *node; uint32_t prev_end = 0; /* handle chunks request with a specific base label */ if (base != MPLS_LABEL_BASE_ANY) return assign_specific_label_chunk(proto, instance, keep, size, base); /* appease scan-build, who gets confused by the use of macros */ assert(lbl_mgr.lc_list); /* first check if there's one available */ for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { if (lmc->proto == NO_PROTO && lmc->end - lmc->start + 1 == size) { lmc->proto = proto; lmc->instance = instance; lmc->keep = keep; return lmc; } /* check if we hadve a "hole" behind us that we can squeeze into */ if ((lmc->start > prev_end) && (lmc->start - prev_end >= size)) { lmc = create_label_chunk(proto, instance, keep, prev_end + 1, prev_end + size); listnode_add_before(lbl_mgr.lc_list, node, lmc); return lmc; } prev_end = lmc->end; } /* otherwise create a new one */ uint32_t start_free; if (list_isempty(lbl_mgr.lc_list)) start_free = MPLS_LABEL_UNRESERVED_MIN; else start_free = ((struct label_manager_chunk *)listgetdata( listtail(lbl_mgr.lc_list))) ->end + 1; if (start_free > MPLS_LABEL_UNRESERVED_MAX - size + 1) { flog_err(EC_ZEBRA_LM_EXHAUSTED_LABELS, "Reached max labels. Start: %u, size: %u", start_free, size); return NULL; } /* create chunk and link at tail */ lmc = create_label_chunk(proto, instance, keep, start_free, start_free + size - 1); listnode_add(lbl_mgr.lc_list, lmc); return lmc; } /** * Core function, release no longer used label chunks * * @param proto Daemon protocol of client, to identify the owner * @param instance Instance, to identify the owner * @param start First label of the chunk * @param end Last label of the chunk * @return 0 on success, -1 otherwise */ int release_label_chunk(uint8_t proto, unsigned short instance, uint32_t start, uint32_t end) { struct listnode *node; struct label_manager_chunk *lmc; int ret = -1; /* check that size matches */ zlog_debug("Releasing label chunk: %u - %u", start, end); /* find chunk and disown */ for (ALL_LIST_ELEMENTS_RO(lbl_mgr.lc_list, node, lmc)) { if (lmc->start != start) continue; if (lmc->end != end) continue; if (lmc->proto != proto || lmc->instance != instance) { flog_err(EC_ZEBRA_LM_DAEMON_MISMATCH, "%s: Daemon mismatch!!", __func__); continue; } lmc->proto = NO_PROTO; lmc->instance = 0; lmc->keep = 0; ret = 0; break; } if (ret != 0) flog_err(EC_ZEBRA_LM_UNRELEASED_CHUNK, "%s: Label chunk not released!!", __func__); return ret; } void label_manager_close(void) { list_delete(&lbl_mgr.lc_list); stream_free(obuf); }