X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=25ed4d019ad347eee1a2cf05890d6f6dc4a0c94e;hp=35b07882275865d3effaf9f54ac538f34ed3cfa0;hb=183a8edd22ba4bc682392c73ae02fc9e121eda68;hpb=5d0b3516d5e8a46ca2268bdb32657b72295501ec diff --git a/src/protocol.c b/src/protocol.c index 35b07882..25ed4d01 100644 --- a/src/protocol.c +++ b/src/protocol.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: protocol.c,v 1.28.4.33 2000/09/17 21:42:05 guus Exp $ + $Id: protocol.c,v 1.28.4.38 2000/10/11 22:01:00 guus Exp $ */ #include "config.h" @@ -43,6 +43,7 @@ #include "net.h" #include "netutl.h" #include "protocol.h" +#include "meta.h" #include "system.h" @@ -61,7 +62,7 @@ int check_id(char *id) return 1; } -/* Generic outgoing request routine - takes care of logging and error detection as well */ +/* Generic request routines - takes care of logging and error detection as well */ int send_request(conn_list_t *cl, const char *format, int request, /*args*/ ...) { @@ -83,24 +84,44 @@ cp return -1; } - if(debug_lvl >= DEBUG_META) - syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request], - cl->name, cl->hostname, buffer); - else if(debug_lvl >= DEBUG_PROTOCOL) + 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); +} - - if(cl->status.encryptin) +int receive_request(conn_list_t *cl) +{ + int request; +cp + if(sscanf(cl->buffer, "%d", &request) == 1) { - /* FIXME: Do encryption */ + 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(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; + } } - - if((write(cl->meta_socket, buffer, len)) < 0) + else { - syslog(LOG_ERR, _("Sending meta data failed: %m")); + syslog(LOG_ERR, _("Bogus data received from %s (%s)"), + cl->name, cl->hostname); return -1; } -cp } /* Connection protocol: @@ -134,16 +155,14 @@ cp int send_id(conn_list_t *cl) { cp - return send_request(cl, "%d %s %d %s", ID, - myself->name, myself->protocol_version, opt2str(myself->options)); + return send_request(cl, "%d %s %d %lx", ID, myself->name, myself->protocol_version, myself->options); } int id_h(conn_list_t *cl) { conn_list_t *old; - char *options; cp - if(sscanf(cl->buffer, "%*d %as %d %as", &cl->name, &cl->protocol_version, &options) != 3) + if(sscanf(cl->buffer, "%*d %as %d %lx", &cl->name, &cl->protocol_version, &cl->options) != 3) { syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname); return -1; @@ -158,14 +177,6 @@ cp return -1; } - /* Check if option string is valid */ - - if((cl->options = str2opt(options)) == -1) - { - syslog(LOG_ERR, _("Peer %s uses invalid option string"), cl->hostname); - return -1; - } - /* Check if identity is a valid name */ if(!check_id(cl->name)) @@ -176,7 +187,7 @@ cp /* Load information about peer */ - if(!read_id(cl)) + if(!read_host_config(cl)) { syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name); return -1; @@ -210,111 +221,76 @@ cp int send_challenge(conn_list_t *cl) { - char *buffer; - int keylength; - int x; + char buffer[CHAL_LENGTH*2+1]; cp - if(cl->chal_answer) - free(cl->chal_answer); - - /* Allocate buffers for the challenge and the hash */ - - cl->chal_answer = xmalloc(SHA_DIGEST_LENGTH); - keylength = BN_num_bytes(cl->rsakey->length); - buffer = xmalloc(keylength*2); + /* Allocate buffers for the challenge */ - /* Copy random data and the public key to the buffer */ - - RAND_bytes(buffer, keylength); - BN_bn2bin(cl->rsakey->length, buffer+keylength); - - /* If we don't have a blowfish key set yet, use the random data from the challenge to do so. */ - - if(!cl->status.encryptin) - { - set_metakey(cl, buffer, keylength); - } + if(!cl->hischallenge) + cl->hischallenge = xmalloc(CHAL_LENGTH); - /* Calculate the hash from that */ + /* Copy random data to the buffer */ - SHA1(buffer, keylength*2, cl->chal_answer); + RAND_bytes(cl->hischallenge, CHAL_LENGTH); /* Convert the random data to a hexadecimal formatted string */ - bin2hex(buffer,buffer,keylength); - buffer[keylength*2] = '\0'; + bin2hex(cl->hischallenge,buffer,CHAL_LENGTH); + buffer[CHAL_LENGTH*2] = '\0'; /* Send the challenge */ cl->allow_request = CHAL_REPLY; - x = send_request(cl, "%d %s", CHALLENGE, buffer); - free(buffer); - cl->status.encryptout = 1; cp - return x; + return send_request(cl, "%d %s", CHALLENGE, buffer); } int challenge_h(conn_list_t *cl) { - char *challenge; - int x; - + char *buffer; cp - if(sscanf(cl->buffer, "%*d %as", &cl->name, &challenge) != 1) + if(sscanf(cl->buffer, "%*d %as", &buffer) != 1) { syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname); return -1; } - /* Rest is done by send_chal_reply() */ - - x = send_chal_reply(cl, challenge); - free(challenge); -cp - return x; -} - -int send_chal_reply(conn_list_t *cl, char *challenge) -{ - char *buffer; - int keylength; - char *hash; - int x; - -cp - keylength = BN_num_bytes(myself->rsakey->length); - /* Check if the length of the challenge is all right */ - if(strlen(challenge) != keylength*2) + if(strlen(buffer) != CHAL_LENGTH*2) { syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname); + free(buffer); return -1; } - /* Allocate buffers for the challenge and the hash */ - - buffer = xmalloc(keylength*2); - hash = xmalloc(SHA_DIGEST_LENGTH*2+1); - - /* Copy the incoming random data and our public key to the buffer */ + /* Allocate buffers for the challenge */ - hex2bin(challenge, buffer, keylength); - BN_bn2bin(myself->rsakey->length, buffer+keylength); + if(!cl->mychallenge) + cl->mychallenge = xmalloc(CHAL_LENGTH); - /* Calculate the hash from that */ + /* Convert the challenge from hexadecimal back to binary */ - SHA1(buffer, keylength*2, hash); - - /* If we don't have a blowfish key set yet, use the random data from the challenge to do so. */ + hex2bin(buffer,cl->mychallenge,CHAL_LENGTH); + free(buffer); + + /* Rest is done by send_chal_reply() */ +cp + return send_chal_reply(cl); +} - if(!cl->status.encrypted) +int send_chal_reply(conn_list_t *cl) +{ + char hash[SHA_DIGEST_LENGTH*2+1]; +cp + if(!cl->mychallenge) { - set_metakey(cl, buffer, keylength); - cl->status.encrypted = 1; + 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 */ - free(buffer); + SHA1(cl->mychallenge, CHAL_LENGTH, hash); /* Convert the hash to a hexadecimal formatted string */ @@ -328,50 +304,54 @@ cp else cl->allow_request = ACK; - x = send_request(cl, "%d %s", CHAL_REPLY, hash); - free(hash); cp - return x; + return send_request(cl, "%d %s", CHAL_REPLY, hash); } int chal_reply_h(conn_list_t *cl) { - char *hash; + char *hishash; + char myhash[SHA_DIGEST_LENGTH]; cp - if(sscanf(cl->buffer, "%*d %as", &cl->name, &hash) != 2) + if(sscanf(cl->buffer, "%*d %as", &hishash) != 2) { 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(hash) != SHA_DIGEST_LENGTH*2) + 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(hash, hash, SHA_DIGEST_LENGTH); + hex2bin(hishash, hishash, SHA_DIGEST_LENGTH); + + /* Calculate the hash from the challenge we sent */ + + SHA1(cl->hischallenge, CHAL_LENGTH, myhash); /* Verify the incoming hash with the calculated hash */ - if(!memcmp(hash, cl->chal_answer, SHA_DIGEST_LENGTH)) + if(!memcmp(hishash, myhash, SHA_DIGEST_LENGTH)) { syslog(LOG_ERR, _("Intruder: wrong challenge reply from %s (%s)"), cl->name, cl->hostname); + 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. */ - - free(hash); - free(cl->chal_answer); - cp if(cl->status.outgoing) { @@ -394,10 +374,9 @@ cp int ack_h(conn_list_t *cl) { conn_list_t *old; - cp /* Okay, before we active the connection, we check if there is another entry - in the connection list with the same vpn_ip. If so, it presumably is an + 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. */ @@ -436,9 +415,14 @@ cp int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet) { + int x; + char *netstr; +cp + x = send_request(cl, "%d %s %s", ADD_SUBNET, + other->name, netstr = net2str(subnet)); + free(netstr); cp - return send_request(cl, "%d %s %s", ADD_SUBNET, - other->name, net2str(subnet)); + return x; } int add_subnet_h(conn_list_t *cl) @@ -450,8 +434,9 @@ int add_subnet_h(conn_list_t *cl) cp if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3) { - syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname); - return -1; + 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 */ @@ -459,16 +444,20 @@ cp 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)) == -1) + 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 */ @@ -476,19 +465,26 @@ cp { 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 */ - if(!(owner = lookup_id(name)) + if(!(owner = lookup_id(name))) { - syslog(LOG_NOTICE, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"), + 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; } + /* If everything is correct, add the subnet to the list of the owner */ + subnet_add(owner, subnet); +cp + return 0; } int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet) @@ -506,8 +502,9 @@ int del_subnet_h(conn_list_t *cl) 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); - return -1; + 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 */ @@ -515,34 +512,47 @@ cp 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)) == -1) + 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; } - /* Check if somebody tries to delete a subnet of ourself */ + 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; } /* Check if the owner of the new subnet is in the connection list */ - if(!(owner = lookup_id(name)) + if(!(owner = lookup_id(name))) { - syslog(LOG_NOTICE, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"), + 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); +cp + return 0; } /* New and closed connections notification */ @@ -550,35 +560,29 @@ cp int send_add_host(conn_list_t *cl, conn_list_t *other) { cp - return send_request(cl, "%d %s %lx:%d %s", ADD_HOST, other->name, other->real_ip, other->port, opt2str(other->options)); + return send_request(cl, "%d %s %s %lx:%d %lx", ADD_HOST, + myself->name, other->name, other->address, other->port, other->options); } int add_host_h(conn_list_t *cl) { - char *options; - conn_list_t *old, *new; + char *sender; + conn_list_t *old, *new, *hisuplink; cp new = new_conn_list(); - if(sscanf(cl->buffer, "%*d %as %lx:%d %as", &new->name, &new->real_ip, &new->port, &options) != 4) + if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &new->name, &new->address, &new->port, &new->options) != 5) { syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname); return -1; } - /* Check if option string is valid */ - - if((new->options = str2opt(options)) == -1) - { - syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid option string"), cl->name, cl->hostname); - return -1; - } - /* Check if identity is a valid name */ - if(!check_id(new->name)) + if(!check_id(new->name) || !check_id(sender)) { syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname); + free(sender); return -1; } @@ -588,18 +592,41 @@ cp { syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname); sighup = 1; + free(sender); return 0; } + /* We got an ADD_HOST from ourself!? */ + + if(!strcmp(sender, myself->name)) + { + syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname); + sighup = 1; + free(sender); + return 0; + } + + /* Lookup his uplink */ + + if(!(new->hisuplink = lookup_id(sender))) + { + syslog(LOG_ERR, _("Got ADD_HOST from %s (%s) with origin %s which is not in our connection list"), + sender, cl->name, cl->hostname); + free(sender); + return -1; + } + + free(sender); + /* Fill in more of the new conn_list structure */ - new->hostname = hostlookup(htonl(new->real_ip)); + 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->real_ip == old->real_ip) && (new->port == old->port)) + 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)"), @@ -618,7 +645,7 @@ cp /* Fill in rest of conn_list structure */ - new->nexthop = cl; + new->myuplink = cl; new->status.active = 1; /* Hook it up into the conn_list */ @@ -636,57 +663,93 @@ cp int send_del_host(conn_list_t *cl, conn_list_t *other) { cp - return send_request(cl, "%d %s %lx:%d", DEL_HOST, - other->name, other->real_ip, other->port); + return send_request(cl, "%d %s %s %lx:%d %lx", DEL_HOST, + myself->name, other->name, other->address, other->port, other->options); } int del_host_h(conn_list_t *cl) { - char *id; + char *name; + char *sender; ip_t address; port_t port; - conn_list_t *old; + int options; + conn_list_t *old, *hisuplink; cp - if(sscanf(cl->buffer, "%*d %as %lx:%d", &id, &address, &port) != 3) + if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &name, &address, &port, &options) != 5) { 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) || !check_id(sender)) + { + syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname); + free(name); free(sender); + return -1; + } + /* Check if somebody tries to delete ourself */ - if(!strcmp(id, myself->name)) + if(!strcmp(name, myself->name)) { syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname); + free(name); free(sender); sighup = 1; return 0; } - /* Check if the new host already exists in the connnection list */ + /* We got an ADD_HOST from ourself!? */ - if((old = lookup_id(id))) + if(!strcmp(sender, myself->name)) { - if((address == old->real_ip) && (port == old->port)) - { - notify_others(old, cl, send_del_host); + syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname); + sighup = 1; + free(name); free(sender); + return 0; + } - old->status.termreq = 1; - old->status.active = 0; + /* Lookup his uplink */ - terminate_connection(old); -cp - return 0; - } + if(!(hisuplink = lookup_id(sender))) + { + syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) with origin %s which is not in our connection list"), + cl->name, cl->hostname, sender); + free(name); free(sender); + return -1; } + + free(sender); - if(debug_lvl > DEBUG_CONNECTIONS) + /* 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 || hisuplink!=old->hisuplink || cl!=old->myuplink) { - syslog(LOG_NOTICE, _("Got DEL_HOST for %s from %s (%s) which is not in our connection list"), - id, cl->name, cl->hostname); + 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.termreq = 1; + old->status.active = 0; + + terminate_connection(old); cp return 0; } @@ -962,43 +1025,7 @@ cp return 0; } -/* Old routines */ - -/* - Notify all my direct connections of a new host - that was added to the vpn, with the exception - of the source of the announcement. -*/ - -int notify_others(conn_list_t *new, conn_list_t *source, - int (*function)(conn_list_t*, conn_list_t*)) -{ - conn_list_t *p; -cp - for(p = conn_list; p != NULL; p = p->next) - if(p != new && p != source && p->status.meta && p->status.active) - function(p, new); -cp - return 0; -} - -/* - Notify one connection of everything - I have connected -*/ - -int notify_one(conn_list_t *new) -{ - conn_list_t *p; -cp - for(p = conn_list; p != NULL; p = p->next) - if(p != new && p->status.active) - send_add_host(new, p); -cp - return 0; -} - -/* "Complete overhaul". */ +/* Jumptable for the request handlers */ int (*request_handlers[])(conn_list_t*) = { id_h, challenge_h, chal_reply_h, ack_h, @@ -1009,6 +1036,8 @@ int (*request_handlers[])(conn_list_t*) = { key_changed_h, req_key_h, ans_key_h, }; +/* Request names */ + char (*request_name[]) = { "ID", "CHALLENGE", "CHAL_REPLY", "ACK", "STATUS", "ERROR", "TERMREQ",