X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=85133954b89ad642675c480c4e9756a21d5c6640;hp=75818043782f0ec57e8298227d3af55d77e3c945;hb=73d77dd416b87b7c4e9b6aa450f64846235cd2b4;hpb=408ca91766088b6c2d38e198b0692bf394b41248 diff --git a/src/protocol.c b/src/protocol.c index 75818043..85133954 100644 --- a/src/protocol.c +++ b/src/protocol.c @@ -1,7 +1,7 @@ /* - protocol.c -- handle the meta-protocol - Copyright (C) 1999,2000 Ivo Timmermans , - 2000 Guus Sliepen + protocol.c -- handle the meta-protocol, basic functions + Copyright (C) 1999-2005 Ivo Timmermans, + 2000-2006 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 @@ -17,1310 +17,237 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: protocol.c,v 1.28.4.62 2000/11/20 19:12:13 guus Exp $ + $Id$ */ -#include "config.h" - -#include - -#include -#include -#include -#include -#include -#include -#include - -#include -#include - -#include - -#ifdef HAVE_OPENSSL_SHA_H -# include -#else -# include -#endif - -#ifdef HAVE_OPENSSL_RAND_H -# include -#else -# include -#endif - -#ifdef HAVE_OPENSSL_EVP_H -# include -#else -# include -#endif - +#include "system.h" #include "conf.h" -#include "net.h" -#include "netutl.h" -#include "protocol.h" -#include "meta.h" #include "connection.h" +#include "logger.h" +#include "meta.h" +#include "protocol.h" +#include "utils.h" +#include "xalloc.h" -#include "system.h" - -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 *cl, 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], cl->name, cl->hostname); - return -1; - } - - len++; - - if(debug_lvl >= DEBUG_PROTOCOL) - syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname); - -cp - return send_meta(cl, buffer, len); -} - -int receive_request(connection_t *cl) -{ - int request; -cp - if(sscanf(cl->buffer, "%d", &request) == 1) - { - if((request < 0) || (request > 255) || (request_handlers[request] == NULL)) - { - syslog(LOG_ERR, _("Unknown request from %s (%s)"), - cl->name, cl->hostname); - return -1; - } - else - { - if(debug_lvl >= DEBUG_PROTOCOL) - syslog(LOG_DEBUG, _("Got %s from %s (%s)"), - request_name[request], cl->name, cl->hostname); - } - - if((cl->allow_request != ALL) && (cl->allow_request != request)) - { - syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname); - return -1; - } - - if(request_handlers[request](cl)) - /* Something went wrong. Probably scriptkiddies. Terminate. */ - { - syslog(LOG_ERR, _("Error while processing %s from %s (%s)"), - request_name[request], cl->name, cl->hostname); - return -1; - } - } - else - { - syslog(LOG_ERR, _("Bogus data received from %s (%s)"), - cl->name, cl->hostname); - return -1; - } -cp - return 0; -} - -/* Connection protocol: - - Client Server - send_id(u) - send_challenge(R) - send_chal_reply(H) - send_id(u) - send_challenge(R) - send_chal_reply(H) - --------------------------------------- - send_metakey(R) - send_metakey(R) - --------------------------------------- - send_ack(u) - send_ack(u) - --------------------------------------- - Other requests(E)... - - (u) Unencrypted, - (R) RSA, - (H) SHA1, - (E) Encrypted with symmetric cipher. - - Part of the challenge is directly used to set the symmetric cipher key and the initial vector. - Since a man-in-the-middle cannot decrypt the RSA challenges, this means that he cannot get or - forge the key for the symmetric cipher. -*/ - -int send_id(connection_t *cl) -{ -cp - cl->allow_request = CHALLENGE; -cp - return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port); -} - -int id_h(connection_t *cl) -{ - connection_t *old; - config_t const *cfg; -cp - if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->name, &cl->protocol_version, &cl->options, &cl->port) != 4) - { - syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname); - return -1; - } - - /* Check if version matches */ - - if(cl->protocol_version != myself->protocol_version) - { - syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"), - cl->name, cl->hostname, cl->protocol_version); - return -1; - } - - /* Check if identity is a valid name */ - - if(check_id(cl->name)) - { - syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname); - return -1; - } - - /* Load information about peer */ -cp - if(read_host_config(cl)) - { - syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name); - return -1; - } - - /* First check if the host we connected to is already in our - connection list. If so, we are probably making a loop, which - is not desirable. - */ -cp - if(cl->status.outgoing) - { - if((old = lookup_id(cl->name))) - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->name, cl->hostname); - cl->status.outgoing = 0; - old->status.outgoing = 1; - terminate_connection(cl); - return 0; - } - } -cp - if((cfg = get_config_val(cl->config, config_publickey))) - { - cl->rsa_key = RSA_new(); - BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr); - BN_hex2bn(&cl->rsa_key->e, "FFFF"); - } - else - { - syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname); - return -1; - } -cp - return send_challenge(cl); -} - -int send_challenge(connection_t *cl) -{ - char *buffer; - int len, x; -cp - len = RSA_size(cl->rsa_key); - - /* Allocate buffers for the challenge */ - - buffer = xmalloc(len*2+1); - - if(cl->hischallenge) - free(cl->hischallenge); - - cl->hischallenge = xmalloc(len); -cp - /* Copy random data to the buffer */ - - RAND_bytes(cl->hischallenge, len); - - cl->hischallenge[0] &= 0x7F; /* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */ - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(cl->hischallenge, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Generated random challenge (unencrypted): %s"), buffer); - } - - /* Encrypt the random data */ - - if(RSA_public_encrypt(len, cl->hischallenge, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */ - { - syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->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 challenge */ - - cl->allow_request = CHAL_REPLY; - x = send_request(cl, "%d %s", CHALLENGE, buffer); - free(buffer); -cp - return x; -} - -int challenge_h(connection_t *cl) -{ - char *buffer; - int len; -cp - if(sscanf(cl->buffer, "%*d %as", &buffer) != 1) - { - syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname); - return -1; - } - - len = RSA_size(myself->rsa_key); - - /* Check if the length of the challenge is all right */ - - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname); - free(buffer); - return -1; - } - - /* Allocate buffers for the challenge */ - - if(!cl->mychallenge) - cl->mychallenge = xmalloc(len); - - /* Convert the challenge from hexadecimal back to binary */ - - hex2bin(buffer,buffer,len); - - /* Decrypt the challenge */ - - if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ - { - syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname); - free(buffer); - return -1; - } - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(cl->mychallenge, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer); - } - - free(buffer); - - /* Rest is done by send_chal_reply() */ -cp - return send_chal_reply(cl); -} - -int send_chal_reply(connection_t *cl) -{ - char hash[SHA_DIGEST_LENGTH*2+1]; -cp - if(!cl->mychallenge) - { - syslog(LOG_ERR, _("Trying to send CHAL_REPLY to %s (%s) without a valid CHALLENGE"), cl->name, cl->hostname); - return -1; - } - - /* Calculate the hash from the challenge we received */ - - SHA1(cl->mychallenge, RSA_size(myself->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 */ - - if(cl->status.outgoing) - cl->allow_request = ID; - else - cl->allow_request = METAKEY; - -cp - return send_request(cl, "%d %s", CHAL_REPLY, hash); -} - -int chal_reply_h(connection_t *cl) -{ - char *hishash; - char myhash[SHA_DIGEST_LENGTH]; -cp - if(sscanf(cl->buffer, "%*d %as", &hishash) != 1) - { - syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname); - free(hishash); - return -1; - } - - /* Check if the length of the hash is all right */ - - if(strlen(hishash) != SHA_DIGEST_LENGTH*2) - { - syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname); - free(hishash); - return -1; - } - - /* Convert the hash to binary format */ - - hex2bin(hishash, hishash, SHA_DIGEST_LENGTH); - - /* Calculate the hash from the challenge we sent */ - - SHA1(cl->hischallenge, RSA_size(cl->rsa_key), myhash); - - /* Verify the incoming hash with the calculated hash */ - - if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH)) - { - syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname); - 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); - } - free(hishash); - return -1; - } - - - free(hishash); - - /* Identity has now been positively verified. - If we are accepting this new connection, then send our identity, - if we are making this connecting, acknowledge. - */ -cp - if(cl->status.outgoing) - return send_metakey(cl); - else - return send_id(cl); -} - -int send_metakey(connection_t *cl) -{ - char *buffer; - int len, x; -cp - len = RSA_size(cl->rsa_key); - - /* Allocate buffers for the meta key */ - - buffer = xmalloc(len*2+1); - - if(!cl->cipher_outkey) - cl->cipher_outkey = xmalloc(len); - - if(!cl->cipher_outctx) - cl->cipher_outctx = xmalloc(sizeof(*cl->cipher_outctx)); -cp - /* Copy random data to the buffer */ - - RAND_bytes(cl->cipher_outkey, len); - - cl->cipher_outkey[0] &= 0x7F; /* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */ - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(cl->cipher_outkey, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer); - } - - /* Encrypt the random data */ - - if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */ - { - syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->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 */ - - if(cl->status.outgoing) - cl->allow_request = METAKEY; - else - cl->allow_request = ACK; - - x = send_request(cl, "%d %s", METAKEY, buffer); - free(buffer); - - EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len); -cp - return x; -} - -int metakey_h(connection_t *cl) -{ - char *buffer; - int len; -cp - if(sscanf(cl->buffer, "%*d %as", &buffer) != 1) - { - syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname); - return -1; - } - - len = RSA_size(myself->rsa_key); - - /* Check if the length of the meta key is all right */ - - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname); - free(buffer); - return -1; - } - - /* Allocate buffers for the meta key */ - - if(!cl->cipher_inkey) - cl->cipher_inkey = xmalloc(len); - - if(!cl->cipher_inctx) - cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx)); - - /* Convert the challenge from hexadecimal back to binary */ - - hex2bin(buffer,buffer,len); - - /* Decrypt the meta key */ - - if(RSA_private_decrypt(len, buffer, cl->cipher_inkey, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ - { - syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname); - free(buffer); - return -1; - } - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(cl->cipher_inkey, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer); - } - - free(buffer); - - EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len); - -cp - if(cl->status.outgoing) - return send_ack(cl); - else - return send_metakey(cl); -} - -int send_ack(connection_t *cl) -{ - int x; -cp - if(cl->status.outgoing) - cl->allow_request = ACK; - - setup_vpn_connection(cl); - - x = send_request(cl, "%d", ACK); - cl->status.encryptout = 1; -cp - return x; -} - -int ack_h(connection_t *cl) -{ - connection_t *old, *p; - subnet_t *subnet; - rbl_t *rbl, *rbl2; -cp - /* Okay, before we active the connection, we check if there is another entry - in the connection list with the same name. If so, it presumably is an - old connection that has timed out but we don't know it yet. - */ - - while((old = lookup_id(cl->name))) - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"), - cl->name, old->hostname, cl->hostname); - - terminate_connection(old); - } - - /* Activate this connection */ - - cl->allow_request = ALL; - cl->status.active = 1; - cl->status.decryptin = 1; - cl->nexthop = cl; - cl->cipher_pkttype = EVP_bf_cfb(); - cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len; - - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname); - -cp - if(!cl->status.outgoing) - send_ack(cl); - - /* Send him our subnets */ - - RBL_FOREACH(myself->subnet_tree, rbl) - { - subnet = (subnet_t *)rbl->data; - send_add_subnet(cl, subnet); - } - /* And send him all the hosts and their subnets we know... */ - - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - - if(p != cl && p->status.active) - { - /* Notify others of this connection */ - - if(p->status.meta) - send_add_host(p, cl); - - /* Notify new connection of everything we know */ - - send_add_host(cl, p); - - RBL_FOREACH(p->subnet_tree, rbl2) - { - subnet = (subnet_t *)rbl2->data; - send_add_subnet(cl, subnet); - } - } - } -cp - return 0; -} - -/* Address and subnet information exchange */ - -int send_add_subnet(connection_t *cl, subnet_t *subnet) -{ - int x; - char *netstr; -cp - x = send_request(cl, "%d %s %s", ADD_SUBNET, - subnet->owner->name, netstr = net2str(subnet)); - free(netstr); -cp - return x; -} - -int add_subnet_h(connection_t *cl) -{ - char *subnetstr; - char *name; - connection_t *owner, *p; - subnet_t *subnet; - rbl_t *rbl; -cp - if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 2) - { - syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname); - free(name); free(subnetstr); - return -1; - } - - /* Check if owner name is a valid */ - - if(check_id(name)) - { - syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(name); free(subnetstr); - return -1; - } - - /* Check if subnet string is valid */ - - if(!(subnet = str2net(subnetstr))) - { - syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname); - free(name); free(subnetstr); - return -1; - } - - free(subnetstr); - - /* Check if somebody tries to add a subnet of ourself */ - - if(!strcmp(name, myself->name)) - { - syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"), - cl->name, cl->hostname); - free(name); - sighup = 1; - return 0; - } - - /* Check if the owner of the new subnet is in the connection list */ +bool tunnelserver = false; - if(!(owner = lookup_id(name))) - { - syslog(LOG_ERR, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"), - name, cl->name, cl->hostname); - free(name); - return -1; - } +/* Jumptable for the request handlers */ - /* If everything is correct, add the subnet to the list of the owner */ +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, +}; - subnet_add(owner, subnet); +/* Request names */ - /* Tell the rest */ - - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - if(p->status.meta && p->status.active && p!= cl) - send_add_subnet(p, subnet); - } -cp - return 0; -} +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 send_del_subnet(connection_t *cl, subnet_t *subnet) -{ - int x; - char *netstr; -cp - netstr = net2str(subnet); - x = send_request(cl, "%d %s %s", DEL_SUBNET, subnet->owner->name, netstr); - free(netstr); -cp - return x; -} +static avl_tree_t *past_request_tree; -int del_subnet_h(connection_t *cl) +bool check_id(const char *id) { - char *subnetstr; - char *name; - connection_t *owner, *p; - subnet_t *subnet; - rbl_t *rbl; -cp - if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3) - { - syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname); - free(name); free(subnetstr); - return -1; - } - - /* Check if owner name is a valid */ - - if(check_id(name)) - { - syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(name); free(subnetstr); - return -1; - } - - /* Check if subnet string is valid */ - - if(!(subnet = str2net(subnetstr))) - { - syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname); - free(name); free(subnetstr); - return -1; - } - - free(subnetstr); - - /* Check if somebody tries to add a subnet of ourself */ - - if(!strcmp(name, myself->name)) - { - syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"), - cl->name, cl->hostname); - free(name); - sighup = 1; - return 0; - } + for(; *id; id++) + if(!isalnum(*id) && *id != '_') + return false; - /* Check if the owner of the new subnet is in the connection list */ - - if(!(owner = lookup_id(name))) - { - syslog(LOG_ERR, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"), - name, cl->name, cl->hostname); - free(name); - return -1; - } - - /* If everything is correct, delete the subnet from the list of the owner */ - - subnet_del(subnet); - - /* Tell the rest */ - - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - if(p->status.meta && p->status.active && p!= cl) - send_del_subnet(p, subnet); - } -cp - return 0; + return true; } -/* New and closed connections notification */ +/* Generic request routines - takes care of logging and error + detection as well */ -int send_add_host(connection_t *cl, connection_t *other) +bool send_request(connection_t *c, const char *format, ...) { -cp - return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST, - other->name, other->address, other->port, other->options); -} - -int add_host_h(connection_t *cl) -{ - connection_t *old, *new, *p; - rbl_t *rbl; -cp - new = new_connection(); - - if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &new->name, &new->address, &new->port, &new->options) != 4) - { - syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname); - return -1; - } + va_list args; + char buffer[MAXBUFSIZE]; + int len, request; - /* Check if identity is a valid name */ + cp(); - if(check_id(new->name)) - { - syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname); - free_connection(new); - return -1; - } + /* Use vsnprintf instead of vxasprintf: faster, no memory + fragmentation, cleanup is automatic, and there is a limit on the + input buffer anyway */ - /* Check if somebody tries to add ourself */ - - if(!strcmp(new->name, myself->name)) - { - syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname); - sighup = 1; - free_connection(new); - return 0; - } - - /* Fill in more of the new connection structure */ - - new->hostname = hostlookup(htonl(new->address)); - - /* Check if the new host already exists in the connnection list */ - - if((old = lookup_id(new->name))) - { - if((new->address == old->address) && (new->port == old->port)) - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"), - old->name, old->hostname, new->name, new->hostname); - free_connection(new); - return 0; - } - else - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Removing old entry for %s (%s) in favour of new connection"), - old->name, old->hostname); - - terminate_connection(old); - } - } - - /* Hook it up into the connection */ - - connection_add(new); - - /* Tell the rest about the new host */ - - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - if(p->status.meta && p->status.active && p!=cl) - send_add_host(p, new); - } - - /* Fill in rest of connection structure */ - - new->nexthop = cl; - new->status.active = 1; - new->cipher_pkttype = EVP_bf_cfb(); - new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len; - - /* Okay this is a bit ugly... it would be better to setup UDP sockets dynamically, or - * perhaps just one UDP socket... but then again, this has benefits too... - */ - - setup_vpn_connection(new); -cp - return 0; -} - -int send_del_host(connection_t *cl, connection_t *other) -{ -cp - return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST, - other->name, other->address, other->port, other->options); -} + va_start(args, format); + len = vsnprintf(buffer, MAXBUFSIZE, format, args); + va_end(args); -int del_host_h(connection_t *cl) -{ - char *name; - ip_t address; - port_t port; - long int options; - connection_t *old, *p; - rbl_t *rbl; -cp - if(sscanf(cl->buffer, "%*d %as %lx:%d %lx", &name, &address, &port, &options) != 4) - { - syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"), - cl->name, cl->hostname); - return -1; - } - - /* Check if identity is a valid name */ - - if(check_id(name)) - { - syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(name); - return -1; - } - - /* Check if somebody tries to delete ourself */ - - if(!strcmp(name, myself->name)) - { - syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"), - cl->name, cl->hostname); - free(name); - sighup = 1; - return 0; - } - - /* Check if the new host already exists in the connnection list */ - - if(!(old = lookup_id(name))) - { - syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) for %s which is not in our connection list"), - name, cl->name, cl->hostname); - free(name); - return -1; - } - - /* Check if the rest matches */ - - if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop) - { - syslog(LOG_WARNING, _("Got DEL_HOST from %s (%s) for %s which doesn't match"), cl->name, cl->hostname, old->name); - return 0; - } - - /* Ok, since EVERYTHING seems to check out all right, delete it */ - - old->status.active = 0; - terminate_connection(old); - - /* Tell the rest about the new host */ + if(len < 0 || len > MAXBUFSIZE - 1) { + logger(LOG_ERR, _("Output buffer overflow while sending request to %s (%s)"), + c->name, c->hostname); + return false; + } - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - if(p->status.meta && p->status.active && p!=cl) - send_del_host(p, old); - } -cp - return 0; -} + 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); + } -/* Status and error notification routines */ + buffer[len++] = '\n'; -int send_status(connection_t *cl, int statusno, char *statusstring) -{ -cp - if(!statusstring) - statusstring = status_text[statusno]; -cp - return send_request(cl, "%d %d %s", STATUS, statusno, statusstring); + if(c == broadcast) { + broadcast_meta(NULL, buffer, len); + return true; + } else + return send_meta(c, buffer, len); } -int status_h(connection_t *cl) +void forward_request(connection_t *from) { - int statusno; - char *statusstring; -cp - if(sscanf(cl->buffer, "%*d %d %as", &statusno, &statusstring) != 2) - { - syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"), - cl->name, cl->hostname); - return -1; - } - - if(debug_lvl >= DEBUG_STATUS) - { - syslog(LOG_NOTICE, _("Status message from %s (%s): %s: %s"), - cl->name, cl->hostname, status_text[statusno], statusstring); - } + int request; -cp - free(statusstring); - return 0; -} + cp(); -int send_error(connection_t *cl, int errno, char *errstring) -{ -cp - if(!errstring) - errstring = strerror(errno); - return send_request(cl, "%d %d %s", ERROR, errno, errstring); -} - -int error_h(connection_t *cl) -{ - int errno; - char *errorstring; -cp - if(sscanf(cl->buffer, "%*d %d %as", &errno, &errorstring) != 2) - { - syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"), - cl->name, cl->hostname); - return -1; - } + 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); + } - if(debug_lvl >= DEBUG_ERROR) - { - syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"), - cl->name, cl->hostname, strerror(errno), errorstring); - } + from->buffer[from->reqlen - 1] = '\n'; + + broadcast_meta(from, from->buffer, from->reqlen); +} + +bool receive_request(connection_t *c) +{ + int request; + + cp(); + + 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; + } - free(errorstring); - terminate_connection(cl); -cp - return 0; + return true; } -int send_termreq(connection_t *cl) +static int past_request_compare(const past_request_t *a, const past_request_t *b) { -cp - return send_request(cl, "%d", TERMREQ); + return strcmp(a->request, b->request); } -int termreq_h(connection_t *cl) +static void free_past_request(past_request_t *r) { -cp - terminate_connection(cl); -cp - return 0; -} + cp(); -/* Keepalive routines - FIXME: needs a closer look */ + if(r->request) + free(r->request); -int send_ping(connection_t *cl) -{ -cp - cl->status.pinged = 1; - cl->last_ping_time = time(NULL); -cp - return send_request(cl, "%d", PING); + free(r); } -int ping_h(connection_t *cl) +void init_requests(void) { -cp - return send_pong(cl); -} + cp(); -int send_pong(connection_t *cl) -{ -cp - return send_request(cl, "%d", PONG); + past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request); } -int pong_h(connection_t *cl) +void exit_requests(void) { -cp - cl->status.pinged = 0; -cp - return 0; -} + cp(); -/* Key exchange */ - -int send_key_changed(connection_t *from, connection_t *cl) -{ - connection_t *p; - rbl_t *rbl; -cp - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - if(p != cl && p->status.meta && p->status.active) - send_request(p, "%d %s", KEY_CHANGED, from->name); - } -cp - return 0; + avl_delete_tree(past_request_tree); } -int key_changed_h(connection_t *cl) +bool seen_request(char *request) { - char *from_id; - connection_t *from; -cp - if(sscanf(cl->buffer, "%*d %as", &from_id) != 1) - { - syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"), - cl->name, cl->hostname); - return -1; - } + past_request_t *new, p = {0}; - if(!(from = lookup_id(from_id))) - { - syslog(LOG_ERR, _("Got KEY_CHANGED from %s (%s) origin %s which does not exist in our connection list"), - cl->name, cl->hostname, from_id); - free(from_id); - return -1; - } + cp(); - free(from_id); + p.request = request; - from->status.validkey = 0; - from->status.waitingforkey = 0; - - send_key_changed(from, cl); -cp - return 0; -} - -int send_req_key(connection_t *from, connection_t *to) -{ -cp - return send_request(to->nexthop, "%d %s %s", REQ_KEY, - from->name, to->name); -} - -int req_key_h(connection_t *cl) -{ - char *from_id, *to_id; - connection_t *from, *to; - char pktkey[129]; -cp - if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2) - { - syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"), - cl->name, cl->hostname); - return -1; - } - - if(!(from = lookup_id(from_id))) - { - syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) origin %s which does not exist in our connection list"), - cl->name, cl->hostname, from_id); - free(from_id); free(to_id); - return -1; - } - - /* Check if this key request is for us */ - - if(!strcmp(to_id, myself->name)) - { - bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength); - pktkey[myself->cipher_pktkeylength*2] = '\0'; - send_ans_key(myself, from, pktkey); - } - else - { - if(!(to = lookup_id(to_id))) - { - syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) destination %s which does not exist in our connection list"), - cl->name, cl->hostname, to_id); - free(from_id); free(to_id); - return -1; - } - - if(to->status.validkey) /* Proxy keys */ - { - bin2hex(to->cipher_pktkey, pktkey, to->cipher_pktkeylength); - pktkey[to->cipher_pktkeylength*2] = '\0'; - send_ans_key(to, from, pktkey); - } - else - send_req_key(from, to); - } - - free(from_id); free(to_id); -cp - return 0; -} - -int send_ans_key(connection_t *from, connection_t *to, char *pktkey) -{ -cp - return send_request(to->nexthop, "%d %s %s %s", ANS_KEY, - from->name, to->name, pktkey); + 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 ans_key_h(connection_t *cl) +void age_past_requests(void) { - char *from_id, *to_id, *pktkey; - int keylength; - connection_t *from, *to; -cp - if(sscanf(cl->buffer, "%*d %as %as %as", &from_id, &to_id, &pktkey) != 3) - { - syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"), - cl->name, cl->hostname); - return -1; - } - - if(!(from = lookup_id(from_id))) - { - syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) origin %s which does not exist in our connection list"), - cl->name, cl->hostname, from_id); - free(from_id); free(to_id); free(pktkey); - return -1; - } - - /* Check correctness of packet key */ - - keylength = strlen(pktkey); - - if(keylength != from->cipher_pktkeylength*2) - { - syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key length"), - cl->name, cl->hostname, from->name); - free(from_id); free(to_id); free(pktkey); - return -1; - } - - /* Forward it if necessary */ + avl_node_t *node, *next; + past_request_t *p; + int left = 0, deleted = 0; - if(strcmp(to_id, myself->name)) - { - if(!(to = lookup_id(to_id))) - { - syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) destination %s which does not exist in our connection list"), - cl->name, cl->hostname, to_id); - free(from_id); free(to_id); - return -1; - } - send_ans_key(from, to, pktkey); - } + cp(); - /* Update our copy of the origin's packet key */ + for(node = past_request_tree->head; node; node = next) { + next = node->next; + p = node->data; - if(from->cipher_pktkey) - free(from->cipher_pktkey); - - keylength /= 2; - hex2bin(pktkey, pktkey, keylength); - pktkey[keylength] = '\0'; - from->cipher_pktkey = pktkey; + if(p->firstseen + pinginterval < now) + avl_delete_node(past_request_tree, node), deleted++; + else + left++; + } - from->status.validkey = 1; - from->status.waitingforkey = 0; - - free(from_id); free(to_id); -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, challenge_h, chal_reply_h, metakey_h, ack_h, - status_h, error_h, termreq_h, - ping_h, pong_h, - add_host_h, del_host_h, - add_subnet_h, del_subnet_h, - key_changed_h, req_key_h, ans_key_h, -}; - -/* Request names */ - -char (*request_name[]) = { - "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK", - "STATUS", "ERROR", "TERMREQ", - "PING", "PONG", - "ADD_HOST", "DEL_HOST", - "ADD_SUBNET", "DEL_SUBNET", - "KEY_CHANGED", "REQ_KEY", "ANS_KEY", -}; - -/* Status strings */ - -char (*status_text[]) = { - "Warning", -}; - -/* Error strings */ - -char (*error_text[]) = { - "Error", -};