/* protocol.c -- handle the meta-protocol Copyright (C) 1999-2001 Ivo Timmermans , 2000,2001 Guus Sliepen This program 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 of the License, or (at your option) any later version. This program 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; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. $Id: protocol.c,v 1.28.4.117 2001/10/31 20:37:54 guus Exp $ */ #include "config.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifndef HAVE_RAND_PSEUDO_BYTES #define RAND_pseudo_bytes RAND_bytes #endif #include "conf.h" #include "net.h" #include "netutl.h" #include "protocol.h" #include "meta.h" #include "connection.h" #include "node.h" #include "edge.h" #include "graph.h" #include "system.h" int mykeyused = 0; int check_id(char *id) { int i; for (i = 0; i < strlen(id); i++) if(!isalnum(id[i]) && id[i] != '_') return -1; return 0; } /* Generic request routines - takes care of logging and error detection as well */ int send_request(connection_t *c, const char *format, ...) { va_list args; char buffer[MAXBUFSIZE]; int len, request; cp /* Use vsnprintf instead of vasprintf: faster, no memory fragmentation, cleanup is automatic, and there is a limit on the input buffer anyway */ va_start(args, format); len = vsnprintf(buffer, MAXBUFSIZE, format, args); request = va_arg(args, int); va_end(args); if(len < 0 || len > MAXBUFSIZE-1) { syslog(LOG_ERR, _("Output buffer overflow while sending %s to %s (%s)"), request_name[request], c->name, c->hostname); return -1; } if(debug_lvl >= DEBUG_PROTOCOL) { if(debug_lvl >= DEBUG_META) syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request], c->name, c->hostname, buffer); else syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], c->name, c->hostname); } buffer[len++] = '\n'; cp return send_meta(c, buffer, len); } int receive_request(connection_t *c) { int request; cp if(sscanf(c->buffer, "%d", &request) == 1) { if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL)) { if(debug_lvl >= DEBUG_META) syslog(LOG_DEBUG, _("Unknown request from %s (%s): %s"), c->name, c->hostname, c->buffer); else syslog(LOG_ERR, _("Unknown request from %s (%s)"), c->name, c->hostname); return -1; } else { if(debug_lvl >= DEBUG_PROTOCOL) { if(debug_lvl >= DEBUG_META) syslog(LOG_DEBUG, _("Got %s from %s (%s): %s"), request_name[request], c->name, c->hostname, c->buffer); else syslog(LOG_DEBUG, _("Got %s from %s (%s)"), request_name[request], c->name, c->hostname); } } if((c->allow_request != ALL) && (c->allow_request != request)) { syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), c->name, c->hostname); return -1; } if(request_handlers[request](c)) /* Something went wrong. Probably scriptkiddies. Terminate. */ { syslog(LOG_ERR, _("Error while processing %s from %s (%s)"), request_name[request], c->name, c->hostname); return -1; } } else { syslog(LOG_ERR, _("Bogus data received from %s (%s)"), c->name, c->hostname); return -1; } cp return 0; } /* The authentication protocol is described in detail in doc/SECURITY2, the rest will be described in doc/PROTOCOL. */ int send_id(connection_t *c) { cp return send_request(c, "%d %s %d", ID, myself->connection->name, myself->connection->protocol_version); } int id_h(connection_t *c) { char name[MAX_STRING_SIZE]; int bla; cp if(sscanf(c->buffer, "%*d "MAX_STRING" %d", name, &c->protocol_version) != 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ID", c->name, c->hostname); return -1; } /* Check if identity is a valid name */ if(check_id(name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ID", c->name, c->hostname, "invalid name"); return -1; } /* If we set c->name in advance, make sure we are connected to the right host */ if(c->name) { if(strcmp(c->name, name)) { syslog(LOG_ERR, _("Peer %s is %s instead of %s"), c->hostname, name, c->name); return -1; } } else c->name = xstrdup(name); /* Check if version matches */ if(c->protocol_version != myself->connection->protocol_version) { syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"), c->name, c->hostname, c->protocol_version); return -1; } if(bypass_security) { if(!c->config_tree) init_configuration(&c->config_tree); c->allow_request = ACK; return send_ack(c); } if(!c->config_tree) { init_configuration(&c->config_tree); if((bla = read_connection_config(c))) { syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), c->hostname, c->name); return -1; } } if(read_rsa_public_key(c)) { return -1; } c->allow_request = METAKEY; cp return send_metakey(c); } int send_metakey(connection_t *c) { char *buffer; int len, x; cp len = RSA_size(c->rsa_key); /* Allocate buffers for the meta key */ buffer = xmalloc(len*2+1); if(!c->outkey) c->outkey = xmalloc(len); if(!c->outctx) c->outctx = xmalloc(sizeof(*c->outctx)); cp /* Copy random data to the buffer */ RAND_bytes(c->outkey, len); /* The message we send must be smaller than the modulus of the RSA key. By definition, for a key of k bits, the following formula holds: 2^(k-1) <= modulus < 2^(k) Where ^ means "to the power of", not "xor". This means that to be sure, we must choose our message < 2^(k-1). This can be done by setting the most significant bit to zero. */ c->outkey[0] &= 0x7F; if(debug_lvl >= DEBUG_SCARY_THINGS) { bin2hex(c->outkey, buffer, len); buffer[len*2] = '\0'; syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer); } /* Encrypt the random data We do not use one of the PKCS padding schemes here. This is allowed, because we encrypt a totally random string with a length equal to that of the modulus of the RSA key. */ if(RSA_public_encrypt(len, c->outkey, buffer, c->rsa_key, RSA_NO_PADDING) != len) { syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname); free(buffer); return -1; } cp /* Convert the encrypted random data to a hexadecimal formatted string */ bin2hex(buffer, buffer, len); buffer[len*2] = '\0'; /* Send the meta key */ x = send_request(c, "%d %s", METAKEY, buffer); free(buffer); /* Further outgoing requests are encrypted with the key we just generated */ EVP_EncryptInit(c->outctx, EVP_bf_cfb(), c->outkey + len - EVP_bf_cfb()->key_len, c->outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); c->status.encryptout = 1; cp return x; } int metakey_h(connection_t *c) { char buffer[MAX_STRING_SIZE]; int len; cp if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name, c->hostname); return -1; } len = RSA_size(myself->connection->rsa_key); /* Check if the length of the meta key is all right */ if(strlen(buffer) != len*2) { syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong keylength"); return -1; } /* Allocate buffers for the meta key */ if(!c->inkey) c->inkey = xmalloc(len); if(!c->inctx) c->inctx = xmalloc(sizeof(*c->inctx)); /* Convert the challenge from hexadecimal back to binary */ hex2bin(buffer,buffer,len); /* Decrypt the meta key */ if(RSA_private_decrypt(len, buffer, c->inkey, myself->connection->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ { syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname); return -1; } if(debug_lvl >= DEBUG_SCARY_THINGS) { bin2hex(c->inkey, buffer, len); buffer[len*2] = '\0'; syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer); } /* All incoming requests will now be encrypted. */ EVP_DecryptInit(c->inctx, EVP_bf_cfb(), c->inkey + len - EVP_bf_cfb()->key_len, c->inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); c->status.decryptin = 1; c->allow_request = CHALLENGE; cp return send_challenge(c); } int send_challenge(connection_t *c) { char *buffer; int len, x; cp /* CHECKME: what is most reasonable value for len? */ len = RSA_size(c->rsa_key); /* Allocate buffers for the challenge */ buffer = xmalloc(len*2+1); if(c->hischallenge) free(c->hischallenge); c->hischallenge = xmalloc(len); cp /* Copy random data to the buffer */ RAND_bytes(c->hischallenge, len); cp /* Convert to hex */ bin2hex(c->hischallenge, buffer, len); buffer[len*2] = '\0'; cp /* Send the challenge */ x = send_request(c, "%d %s", CHALLENGE, buffer); free(buffer); cp return x; } int challenge_h(connection_t *c) { char buffer[MAX_STRING_SIZE]; int len; cp if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "CHALLENGE", c->name, c->hostname); return -1; } len = RSA_size(myself->connection->rsa_key); /* Check if the length of the challenge is all right */ if(strlen(buffer) != len*2) { syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong challenge length"); return -1; } /* Allocate buffers for the challenge */ if(!c->mychallenge) c->mychallenge = xmalloc(len); /* Convert the challenge from hexadecimal back to binary */ hex2bin(buffer,c->mychallenge,len); c->allow_request = CHAL_REPLY; /* Rest is done by send_chal_reply() */ cp return send_chal_reply(c); } int send_chal_reply(connection_t *c) { char hash[SHA_DIGEST_LENGTH*2+1]; cp /* Calculate the hash from the challenge we received */ SHA1(c->mychallenge, RSA_size(myself->connection->rsa_key), hash); /* Convert the hash to a hexadecimal formatted string */ bin2hex(hash,hash,SHA_DIGEST_LENGTH); hash[SHA_DIGEST_LENGTH*2] = '\0'; /* Send the reply */ cp return send_request(c, "%d %s", CHAL_REPLY, hash); } int chal_reply_h(connection_t *c) { char hishash[MAX_STRING_SIZE]; char myhash[SHA_DIGEST_LENGTH]; cp if(sscanf(c->buffer, "%*d "MAX_STRING, hishash) != 1) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "CHAL_REPLY", c->name, c->hostname); return -1; } /* Check if the length of the hash is all right */ if(strlen(hishash) != SHA_DIGEST_LENGTH*2) { syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply length")); return -1; } /* Convert the hash to binary format */ hex2bin(hishash, hishash, SHA_DIGEST_LENGTH); /* Calculate the hash from the challenge we sent */ SHA1(c->hischallenge, RSA_size(c->rsa_key), myhash); /* Verify the incoming hash with the calculated hash */ if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH)) { syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply")); if(debug_lvl >= DEBUG_SCARY_THINGS) { bin2hex(myhash, hishash, SHA_DIGEST_LENGTH); hishash[SHA_DIGEST_LENGTH*2] = '\0'; syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash); } return -1; } /* Identity has now been positively verified. Send an acknowledgement with the rest of the information needed. */ c->allow_request = ACK; cp return send_ack(c); } int send_ack(connection_t *c) { /* ACK message contains rest of the information the other end needs to create node_t and edge_t structures. */ struct timeval now; /* Estimate weight */ gettimeofday(&now, NULL); c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000; cp return send_request(c, "%d %hd %d", ACK, myself->port, c->estimated_weight); } int ack_h(connection_t *c) { port_t port; int weight; node_t *n; subnet_t *s; edge_t *e; connection_t *other; avl_node_t *node, *node2; cp if(sscanf(c->buffer, "%*d %hd %d", &port, &weight) != 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ACK", c->name, c->hostname); return -1; } /* Check if we already have a node_t for him */ n = lookup_node(c->name); if(!n) { n = new_node(); n->name = xstrdup(c->name); n->address = c->address; n->hostname = xstrdup(c->hostname); n->port = port; /* FIXME: Also check if no other tinc daemon uses the same IP and port for UDP traffic */ node_add(n); } else { if(n->connection) { /* Oh dear, we already have a connection to this node. */ syslog(LOG_DEBUG, _("Established a second connection with %s (%s), closing old connection"), n->name, n->hostname); terminate_connection(n->connection, 0); } /* FIXME: check if information in existing node matches that of the other end of this connection */ } n->connection = c; c->node = n; /* Check some options if((cfg = get_config_val(c->config, config_indirectdata))) { if(cfg->data.val == stupid_true) c->options |= OPTION_INDIRECT; } if((cfg = get_config_val(c->config, config_tcponly))) { if(cfg->data.val == stupid_true) c->options |= OPTION_TCPONLY; } if((myself->options | c->options) & OPTION_INDIRECT) c->via = myself; else c->via = c; */ /* Create an edge_t for this connection */ c->edge = new_edge(); c->edge->from = myself; c->edge->to = n; c->edge->weight = (weight + c->estimated_weight) / 2; c->edge->connection = c; edge_add(c->edge); /* Activate this connection */ c->allow_request = ALL; c->status.active = 1; c->node->cipher = EVP_bf_cbc(); c->node->keylength = c->node->cipher->key_len + c->node->cipher->iv_len; if(debug_lvl >= DEBUG_CONNECTIONS) syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), c->name, c->hostname); cp /* Send him our subnets */ for(node = myself->subnet_tree->head; node; node = node->next) { s = (subnet_t *)node->data; send_add_subnet(c, s); } /* And send him all known nodes and their subnets */ for(node = node_tree->head; node; node = node->next) { n = (node_t *)node->data; if(n == c->node || n == myself) continue; send_add_node(c, n); for(node2 = c->node->subnet_tree->head; node2; node2 = node2->next) { s = (subnet_t *)node2->data; send_add_subnet(c, s); } } /* Send all known edges */ for(node = edge_tree->head; node; node = node->next) { e = (edge_t *)node->data; if(e == c->edge) continue; send_add_edge(c, e); } /* Notify others of this connection */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other == c) continue; send_add_node(other, c->node); send_add_edge(other, c->edge); } /* Run MST and SSSP algorithms */ mst_kruskal(); sssp_bfs(0); cp return 0; } /* Address and subnet information exchange */ int send_add_subnet(connection_t *c, subnet_t *subnet) { int x; char *netstr; cp x = send_request(c, "%d %s %s", ADD_SUBNET, subnet->owner->name, netstr = net2str(subnet)); free(netstr); cp return x; } int add_subnet_h(connection_t *c) { char subnetstr[MAX_STRING_SIZE]; char name[MAX_STRING_SIZE]; node_t *owner; connection_t *other; subnet_t *s; avl_node_t *node; cp if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ADD_SUBNET", c->name, c->hostname); return -1; } /* Check if owner name is a valid */ if(check_id(name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_SUBNET", c->name, c->hostname, _("invalid name")); return -1; } /* Check if subnet string is valid */ if(!(s = str2net(subnetstr))) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_SUBNET", c->name, c->hostname, _("invalid subnet string")); return -1; } /* Check if the owner of the new subnet is in the connection list */ if(!(owner = lookup_node(name))) { syslog(LOG_ERR, _("Got ADD_SUBNET from %s (%s) for %s which is not in our connection list"), name, c->name, c->hostname); return -1; } /* If everything is correct, add the subnet to the list of the owner */ subnet_add(owner, s); /* Tell the rest */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other->status.active && other != c) send_add_subnet(other, s); } cp return 0; } int send_del_subnet(connection_t *c, subnet_t *s) { int x; char *netstr; cp x = send_request(c, "%d %s %s", DEL_SUBNET, s->owner->name, netstr = net2str(s)); free(netstr); cp return x; } int del_subnet_h(connection_t *c) { char subnetstr[MAX_STRING_SIZE]; char name[MAX_STRING_SIZE]; node_t *owner; connection_t *other; subnet_t *s, *find; avl_node_t *node; cp if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 3) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "DEL_SUBNET", c->name, c->hostname); return -1; } /* Check if owner name is a valid */ if(check_id(name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_SUBNET", c->name, c->hostname, _("invalid name")); return -1; } /* Check if subnet string is valid */ if(!(s = str2net(subnetstr))) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_SUBNET", c->name, c->hostname, _("invalid subnet string")); return -1; } /* Check if the owner of the new subnet is in the connection list */ if(!(owner = lookup_node(name))) { syslog(LOG_ERR, _("Got %s from %s (%s) for %s which is not in our connection list"), "DEL_SUBNET", c->name, c->hostname, name); return -1; } /* If everything is correct, delete the subnet from the list of the owner */ find = lookup_subnet(owner, s); if(!find) { syslog(LOG_ERR, _("Got %s from %s (%s) for %s which does not appear in his subnet tree"), "DEL_SUBNET", c->name, c->hostname, name); return -1; } subnet_del(owner, s); /* Tell the rest */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other->status.active && other != c) send_del_subnet(other, s); } cp return 0; } /* New and closed connections notification */ int send_add_node(connection_t *c, node_t *n) { cp return send_request(c, "%d %s %lx:%d", ADD_NODE, n->name, n->address, n->port); } int add_node_h(connection_t *c) { connection_t *other; node_t *n; char name[MAX_STRING_SIZE]; ipv4_t address; port_t port; avl_node_t *node; cp if(sscanf(c->buffer, "%*d "MAX_STRING" %lx:%hd", name, &address, &port) != 3) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ADD_NODE", c->name, c->hostname); return -1; } /* Check if identity is a valid name */ if(check_id(name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_NODE", c->name, c->hostname, _("invalid name")); return -1; } /* Check if node already exists */ n = lookup_node(name); if(n) { /* Check if it matches */ if(n->address != address || n->port != port) syslog(LOG_DEBUG, _("Got %s from %s (%s) for %s which does not match existing entry"), "ADD_NODE", c->name, c->hostname, n->name); return 0; } else { n = new_node(); n->name = xstrdup(name); n->address = address; n->port = port; node_add(n); } /* Tell the rest about the new node */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other->status.active && other !=c) send_add_node(other, n); } cp return 0; } int send_del_node(connection_t *c, node_t *n) { cp return send_request(c, "%d %s %lx:%d", DEL_NODE, n->name, n->address, n->port); } int del_node_h(connection_t *c) { node_t *n; char name[MAX_STRING_SIZE]; ipv4_t address; port_t port; connection_t *other; avl_node_t *node; cp if(sscanf(c->buffer, "%*d "MAX_STRING" %lx:%hd", name, &address, &port) != 3) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "DEL_NODE", c->name, c->hostname); return -1; } /* Check if identity is a valid name */ if(check_id(name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_NODE", c->name, c->hostname, _("invalid name")); return -1; } /* Check if somebody tries to delete ourself */ if(!strcmp(name, myself->name)) { syslog(LOG_ERR, _("Got %s from %s (%s) for ourself!"), "DEL_NODE", c->name, c->hostname); return -1; } /* Check if the deleted host exists */ n = lookup_node(name); if(!n) { syslog(LOG_WARNING, _("Got %s from %s (%s) for %s which does not exist"), "DEL_NODE", c->name, c->hostname, n->name); return 0; } /* Check if the rest matches */ if(address != n->address || port != n->port) { syslog(LOG_WARNING, _("Got %s from %s (%s) for %s which does not match existing entry"), "DEL_NODE", c->name, c->hostname, n->name); } /* Tell the rest about the deleted node */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other->status.active && other != c) send_del_node(other, n); } /* Delete the node */ node_del(n); mst_kruskal(); sssp_bfs(0); cp return 0; } /* Edges */ int send_add_edge(connection_t *c, edge_t *e) { cp return send_request(c, "%d %s %s %lx %d", ADD_EDGE, e->from->name, e->to->name, e->options, e->weight); } int add_edge_h(connection_t *c) { connection_t *other; edge_t *e; node_t *from, *to; char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; long int options; int weight; avl_node_t *node; cp if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" %lx %d", from_name, to_name, &options, &weight) != 4) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ADD_EDGE", c->name, c->hostname); return -1; } /* Check if names are valid */ if(check_id(from_name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_EDGE", c->name, c->hostname, _("invalid name")); return -1; } if(check_id(to_name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_EDGE", c->name, c->hostname, _("invalid name")); return -1; } /* Lookup nodes */ from = lookup_node(from_name); if(!from) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_EDGE", c->name, c->hostname, _("unknown node")); return -1; } to = lookup_node(to_name); if(!to) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ADD_EDGE", c->name, c->hostname, _("unknown node")); return -1; } /* Check if edge already exists */ e = lookup_edge(from, to); if(e) { if(e->weight != weight || e->options != options) { syslog(LOG_ERR, _("Got %s from %s (%s) which does not match existing entry"), "ADD_EDGE", c->name, c->hostname); return -1; } return 0; } else { e = new_edge(); e->from = from; e->to = to; e->options = options; e->weight = weight; edge_add(e); } /* Tell the rest about the new edge */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other->status.active && other != c) send_add_edge(other, e); } /* Run MST before or after we tell the rest? */ mst_kruskal(); sssp_bfs(0); cp return 0; } int send_del_edge(connection_t *c, edge_t *e) { cp return send_request(c, "%d %s %s %lx %d", DEL_EDGE, e->from->name, e->to->name, e->options, e->weight); } int del_edge_h(connection_t *c) { edge_t *e; char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; node_t *from, *to; long int options; int weight; connection_t *other; avl_node_t *node; cp if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" %lx %d", from_name, to_name, &options, &weight) != 4) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "DEL_EDGE", c->name, c->hostname); return -1; } /* Check if names are valid */ if(check_id(from_name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_EDGE", c->name, c->hostname, _("invalid name")); return -1; } if(check_id(to_name)) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_EDGE", c->name, c->hostname, _("invalid name")); return -1; } /* Lookup nodes */ from = lookup_node(from_name); if(!from) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_EDGE", c->name, c->hostname, _("unknown node")); return -1; } to = lookup_node(to_name); if(!to) { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_EDGE", c->name, c->hostname, _("unknown node")); return -1; } /* Check if edge exists */ e = lookup_edge(from, to); if(e) { if(e->weight != weight || e->options != options) { syslog(LOG_ERR, _("Got %s from %s (%s) which does not match existing entry"), "ADD_EDGE", c->name, c->hostname); return -1; } } else { syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "DEL_EDGE", c->name, c->hostname, _("unknown edge")); return -1; } /* Tell the rest about the deleted edge */ for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other->status.active && other != c) send_del_edge(other, e); } /* Delete the edge */ edge_del(e); /* Run MST before or after we tell the rest? */ mst_kruskal(); sssp_bfs(1); cp return 0; } /* Status and error notification routines */ int send_status(connection_t *c, int statusno, char *statusstring) { cp if(!statusstring) statusstring = status_text[statusno]; cp return send_request(c, "%d %d %s", STATUS, statusno, statusstring); } int status_h(connection_t *c) { int statusno; char statusstring[MAX_STRING_SIZE]; cp if(sscanf(c->buffer, "%*d %d "MAX_STRING, &statusno, statusstring) != 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "STATUS", c->name, c->hostname); return -1; } if(debug_lvl >= DEBUG_STATUS) { syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"), c->name, c->hostname, status_text[statusno], statusstring); } cp return 0; } int send_error(connection_t *c, int err, char *errstring) { cp if(!errstring) errstring = strerror(err); return send_request(c, "%d %d %s", ERROR, err, errstring); } int error_h(connection_t *c) { int err; char errorstring[MAX_STRING_SIZE]; cp if(sscanf(c->buffer, "%*d %d "MAX_STRING, &err, errorstring) != 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ERROR", c->name, c->hostname); return -1; } if(debug_lvl >= DEBUG_ERROR) { syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"), c->name, c->hostname, strerror(err), errorstring); } terminate_connection(c, c->status.active); cp return 0; } int send_termreq(connection_t *c) { cp return send_request(c, "%d", TERMREQ); } int termreq_h(connection_t *c) { cp terminate_connection(c, c->status.active); cp return 0; } int send_ping(connection_t *c) { char salt[SALTLEN*2+1]; cp c->status.pinged = 1; c->last_ping_time = time(NULL); RAND_pseudo_bytes(salt, SALTLEN); bin2hex(salt, salt, SALTLEN); salt[SALTLEN*2] = '\0'; cp return send_request(c, "%d %s", PING, salt); } int ping_h(connection_t *c) { cp return send_pong(c); } int send_pong(connection_t *c) { char salt[SALTLEN*2+1]; cp RAND_pseudo_bytes(salt, SALTLEN); bin2hex(salt, salt, SALTLEN); salt[SALTLEN*2] = '\0'; cp return send_request(c, "%d %s", PONG, salt); } int pong_h(connection_t *c) { cp c->status.pinged = 0; cp return 0; } /* Key exchange */ int send_key_changed(connection_t *c, node_t *n) { connection_t *other; avl_node_t *node; cp /* Only send this message if some other daemon requested our key previously. This reduces unnecessary key_changed broadcasts. */ if(n == myself && !mykeyused) return 0; for(node = connection_tree->head; node; node = node->next) { other = (connection_t *)node->data; if(other != c && other->status.active) send_request(other, "%d %s", KEY_CHANGED, n->name); } cp return 0; } int key_changed_h(connection_t *c) { char name[MAX_STRING_SIZE]; node_t *n; cp if(sscanf(c->buffer, "%*d "MAX_STRING, name) != 1) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "KEY_CHANGED", c->name, c->hostname); return -1; } n = lookup_node(name); if(!n) { syslog(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist"), "KEY_CHANGED", c->name, c->hostname, name); return -1; } n->status.validkey = 0; n->status.waitingforkey = 0; send_key_changed(c, n); cp return 0; } int send_req_key(connection_t *c, node_t *from, node_t *to) { cp return send_request(c, "%d %s %s", REQ_KEY, from->name, to->name); } int req_key_h(connection_t *c) { char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; node_t *from, *to; char key[MAX_STRING_SIZE]; cp if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "REQ_KEY", c->name, c->hostname); return -1; } from = lookup_node(from_name); if(!from) { syslog(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"), "REQ_KEY", c->name, c->hostname, from_name); return -1; } to = lookup_node(to_name); if(!to) { syslog(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"), "REQ_KEY", c->name, c->hostname, to_name); return -1; } /* Check if this key request is for us */ if(to == myself) /* Yes, send our own key back */ { bin2hex(myself->key, key, myself->keylength); key[myself->keylength * 2] = '\0'; send_ans_key(c, myself, from, key); mykeyused = 1; } else { if(to->status.validkey) /* Proxy keys */ { bin2hex(to->key, key, to->keylength); key[to->keylength * 2] = '\0'; send_ans_key(c, to, from, key); } else send_req_key(to->nexthop->connection, from, to); } cp return 0; } int send_ans_key(connection_t *c, node_t *from, node_t *to, char *key) { cp return send_request(c, "%d %s %s %s", ANS_KEY, from->name, to->name, key); } int ans_key_h(connection_t *c) { char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; char key[MAX_STRING_SIZE]; int keylength; node_t *from, *to; cp if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING, from_name, to_name, key) != 3) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ANS_KEY", c->name, c->hostname); return -1; } from = lookup_node(from_name); if(!from) { syslog(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"), "ANS_KEY", c->name, c->hostname, from_name); return -1; } to = lookup_node(to_name); if(!to) { syslog(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"), "ANS_KEY", c->name, c->hostname, to_name); return -1; } /* Check correctness of packet key */ keylength = strlen(key); if(keylength != from->keylength * 2) { syslog(LOG_ERR, _("Got bad %s from %s (%s) origin %s: %s"), "ANS_KEY", c->name, c->hostname, from->name, _("invalid key length")); return -1; } /* Forward it if necessary */ if(to != myself) { send_ans_key(to->nexthop->connection, from, to, key); } /* Update our copy of the origin's packet key */ if(from->key) free(from->key); from->key = xstrdup(key); keylength /= 2; hex2bin(from->key, from->key, keylength); from->key[keylength] = '\0'; from->status.validkey = 1; from->status.waitingforkey = 0; flush_queue(from); cp return 0; } int send_tcppacket(connection_t *c, vpn_packet_t *packet) { int x; cp /* Evil hack. */ x = send_request(c, "%d %hd", PACKET, packet->len); if(x) return x; cp return send_meta(c, packet->data, packet->len); } int tcppacket_h(connection_t *c) { short int len; cp if(sscanf(c->buffer, "%*d %hd", &len) != 1) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "PACKET", c->name, c->hostname); return -1; } /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */ c->tcplen = len; cp return 0; } /* Jumptable for the request handlers */ int (*request_handlers[])(connection_t*) = { id_h, metakey_h, challenge_h, chal_reply_h, ack_h, status_h, error_h, termreq_h, ping_h, pong_h, add_node_h, del_node_h, add_subnet_h, del_subnet_h, add_edge_h, del_edge_h, key_changed_h, req_key_h, ans_key_h, tcppacket_h, }; /* Request names */ char (*request_name[]) = { "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "ACK", "STATUS", "ERROR", "TERMREQ", "PING", "PONG", "ADD_NODE", "DEL_NODE", "ADD_SUBNET", "DEL_SUBNET", "ADD_EDGE", "DEL_EDGE", "KEY_CHANGED", "REQ_KEY", "ANS_KEY", "PACKET", }; /* Status strings */ char (*status_text[]) = { "Warning", }; /* Error strings */ char (*error_text[]) = { "Error", };