X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=f36538e382899ca4f4d3a27ff4267899fb64f185;hp=6cb8037940f7296a1be2c99a5dacda3929f19864;hb=0a84f9cb8f52f2d2b4f03a5ad5ef9dfcd3509033;hpb=54b756f7dfb71c5622b7738fd449e126da959864 diff --git a/src/protocol.c b/src/protocol.c index 6cb80379..f36538e3 100644 --- a/src/protocol.c +++ b/src/protocol.c @@ -1,7 +1,7 @@ /* - protocol.c -- handle the meta-protocol - Copyright (C) 1999-2001 Ivo Timmermans , - 2000,2001 Guus Sliepen + protocol.c -- handle the meta-protocol, basic functions + Copyright (C) 1999-2005 Ivo Timmermans, + 2000-2012 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 @@ -13,1541 +13,228 @@ 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 1.28.4.116 2001/10/31 20:02:06 guus Exp $ + 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., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "config.h" - -#include - -#include -#include -#include -#include -#include -#include -#include -#include +#include "system.h" -#include -#include -#include -#include +#include "conf.h" +#include "connection.h" +#include "logger.h" +#include "meta.h" +#include "protocol.h" +#include "utils.h" +#include "xalloc.h" -#include +bool tunnelserver = false; +bool strictsubnets = false; -#include -#include -#include +/* Jumptable for the request handlers */ -#ifndef HAVE_RAND_PSEUDO_BYTES -#define RAND_pseudo_bytes RAND_bytes -#endif +static bool (*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_subnet_h, del_subnet_h, + add_edge_h, del_edge_h, + key_changed_h, req_key_h, ans_key_h, tcppacket_h, +}; -#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" +/* Request names */ -#include "system.h" +static char (*request_name[]) = { + "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "ACK", + "STATUS", "ERROR", "TERMREQ", + "PING", "PONG", + "ADD_SUBNET", "DEL_SUBNET", + "ADD_EDGE", "DEL_EDGE", "KEY_CHANGED", "REQ_KEY", "ANS_KEY", "PACKET", +}; -int mykeyused = 0; +static avl_tree_t *past_request_tree; -int check_id(char *id) -{ - int i; +bool check_id(const char *id) { + for(; *id; id++) + if(!isalnum(*id) && *id != '_') + return false; - for (i = 0; i < strlen(id); i++) - if(!isalnum(id[i]) && id[i] != '_') - return -1; - - return 0; + return true; } /* 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); +bool send_request(connection_t *c, const char *format, ...) { + va_list args; + char buffer[MAXBUFSIZE]; + int len, request = 0; - 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; - } + /* Use vsnprintf instead of vxasprintf: faster, no memory + fragmentation, cleanup is automatic, and there is a limit on the + input buffer anyway */ - 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); - } + va_start(args, format); + len = vsnprintf(buffer, MAXBUFSIZE, format, args); + va_end(args); - 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(len < 0 || len > MAXBUFSIZE - 1) { + logger(LOG_ERR, "Output buffer overflow while sending request to %s (%s)", + c->name, c->hostname); + return false; } - 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_NODE, - 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); - } + ifdebug(PROTOCOL) { + sscanf(buffer, "%d", &request); + ifdebug(META) + logger(LOG_DEBUG, "Sending %s to %s (%s): %s", + request_name[request], c->name, c->hostname, buffer); + else + logger(LOG_DEBUG, "Sending %s to %s (%s)", request_name[request], + c->name, c->hostname); + } -cp - return 0; -} + buffer[len++] = '\n'; -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); + if(c == everyone) { + broadcast_meta(NULL, buffer, len); + return true; + } else + return send_meta(c, buffer, len); } -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; - } +void forward_request(connection_t *from) { + int request; - if(debug_lvl >= DEBUG_ERROR) - { - syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"), - c->name, c->hostname, strerror(err), errorstring); - } + ifdebug(PROTOCOL) { + sscanf(from->buffer, "%d", &request); + ifdebug(META) + logger(LOG_DEBUG, "Forwarding %s from %s (%s): %s", + request_name[request], from->name, from->hostname, + from->buffer); + else + logger(LOG_DEBUG, "Forwarding %s from %s (%s)", + request_name[request], from->name, from->hostname); + } - terminate_connection(c, c->status.active); -cp - return 0; -} + from->buffer[from->reqlen - 1] = '\n'; -int send_termreq(connection_t *c) -{ -cp - return send_request(c, "%d", TERMREQ); + broadcast_meta(from, from->buffer, from->reqlen); } -int termreq_h(connection_t *c) -{ -cp - terminate_connection(c, c->status.active); -cp - return 0; -} +bool receive_request(connection_t *c) { + int request; -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); -} + if(proxytype == PROXY_HTTP && c->allow_request == ID) { + if(!c->buffer[0] || c->buffer[0] == '\r') + return true; + if(!strncasecmp(c->buffer, "HTTP/1.1 ", 9)) { + if(!strncmp(c->buffer + 9, "200", 3)) { + logger(LOG_DEBUG, "Proxy request granted"); + return true; + } else { + logger(LOG_DEBUG, "Proxy request rejected: %s", c->buffer + 9); + return false; + } + } + } -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); -} + if(sscanf(c->buffer, "%d", &request) == 1) { + if((request < 0) || (request >= LAST) || !request_handlers[request]) { + ifdebug(META) + logger(LOG_DEBUG, "Unknown request from %s (%s): %s", + c->name, c->hostname, c->buffer); + else + logger(LOG_ERR, "Unknown request from %s (%s)", + c->name, c->hostname); + + return false; + } else { + ifdebug(PROTOCOL) { + ifdebug(META) + logger(LOG_DEBUG, "Got %s from %s (%s): %s", + request_name[request], c->name, c->hostname, + c->buffer); + else + logger(LOG_DEBUG, "Got %s from %s (%s)", + request_name[request], c->name, c->hostname); + } + } + + if((c->allow_request != ALL) && (c->allow_request != request)) { + logger(LOG_ERR, "Unauthorized request from %s (%s)", c->name, + c->hostname); + return false; + } + + if(!request_handlers[request](c)) { + /* Something went wrong. Probably scriptkiddies. Terminate. */ + + logger(LOG_ERR, "Error while processing %s from %s (%s)", + request_name[request], c->name, c->hostname); + return false; + } + } else { + logger(LOG_ERR, "Bogus data received from %s (%s)", + c->name, c->hostname); + return false; + } -int pong_h(connection_t *c) -{ -cp - c->status.pinged = 0; -cp - return 0; + return true; } -/* 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; +static int past_request_compare(const past_request_t *a, const past_request_t *b) { + return strcmp(a->request, b->request); } -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; -} +static void free_past_request(past_request_t *r) { + if(r->request) + free(r->request); -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); + free(r); } -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; +void init_requests(void) { + past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request); } -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); +void exit_requests(void) { + avl_delete_tree(past_request_tree); } -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); +bool seen_request(char *request) { + past_request_t *new, p = {NULL}; - 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; - } + p.request = request; - /* 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; + if(avl_search(past_request_tree, &p)) { + ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Already seen request"); + return true; + } else { + new = xmalloc(sizeof(*new)); + new->request = xstrdup(request); + new->firstseen = now; + avl_insert(past_request_tree, new); + return false; + } } -int send_tcppacket(connection_t *c, vpn_packet_t *packet) -{ - int x; -cp - /* Evil hack. */ +void age_past_requests(void) { + avl_node_t *node, *next; + past_request_t *p; + int left = 0, deleted = 0; - x = send_request(c, "%d %hd", PACKET, packet->len); + for(node = past_request_tree->head; node; node = next) { + next = node->next; + p = node->data; - 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. */ + if(p->firstseen + pinginterval <= now) + avl_delete_node(past_request_tree, node), deleted++; + else + left++; + } - c->tcplen = len; -cp - return 0; + if(left || deleted) + ifdebug(SCARY_THINGS) logger(LOG_DEBUG, "Aging past requests: deleted %d, left %d", + deleted, left); } - -/* 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", -};