/* protocol.c -- handle the meta-protocol, basic functions Copyright (C) 1999-2005 Ivo Timmermans, 2000-2013 Guus Sliepen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #include "system.h" #include "conf.h" #include "connection.h" #include "logger.h" #include "meta.h" #include "protocol.h" #include "utils.h" #include "xalloc.h" bool tunnelserver = false; bool strictsubnets = false; bool experimental = true; /* Jumptable for the request handlers */ static bool (*request_handlers[])(connection_t *, const char *) = { id_h, metakey_h, challenge_h, chal_reply_h, ack_h, NULL, NULL, 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, control_h, NULL, NULL, /* Not "real" requests (yet) */ sptps_tcppacket_h, udp_info_h, mtu_info_h, }; /* Request names */ 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", "CONTROL", "REQ_PUBKEY", "ANS_PUBKEY", "SPTPS_PACKET", "UDP_INFO", "MTU_INFO", }; static splay_tree_t *past_request_tree; /* Generic request routines - takes care of logging and error detection as well */ bool send_request(connection_t *c, const char *format, ...) { va_list args; char request[MAXBUFSIZE]; int len; /* Use vsnprintf instead of vxasprintf: faster, no memory fragmentation, cleanup is automatic, and there is a limit on the input buffer anyway */ va_start(args, format); len = vsnprintf(request, sizeof(request), format, args); request[sizeof(request) - 1] = 0; va_end(args); if(len < 0 || (size_t)len > sizeof(request) - 1) { logger(DEBUG_ALWAYS, LOG_ERR, "Output buffer overflow while sending request to %s (%s)", c->name, c->hostname); return false; } int id = atoi(request); logger(DEBUG_META, LOG_DEBUG, "Sending %s to %s (%s): %s", request_name[id], c->name, c->hostname, request); request[len++] = '\n'; if(c == everyone) { broadcast_meta(NULL, request, len); return true; } else { if(id) { return send_meta(c, request, len); } else { send_meta_raw(c, request, len); return true; } } } void forward_request(connection_t *from, const char *request) { logger(DEBUG_META, LOG_DEBUG, "Forwarding %s from %s (%s): %s", request_name[atoi(request)], from->name, from->hostname, request); // Create a temporary newline-terminated copy of the request int len = strlen(request); char tmp[len + 1]; memcpy(tmp, request, len); tmp[len] = '\n'; broadcast_meta(from, tmp, sizeof(tmp)); } bool receive_request(connection_t *c, const char *request) { if(c->outgoing && proxytype == PROXY_HTTP && c->allow_request == ID) { if(!request[0] || request[0] == '\r') { return true; } if(!strncasecmp(request, "HTTP/1.1 ", 9)) { if(!strncmp(request + 9, "200", 3)) { logger(DEBUG_CONNECTIONS, LOG_DEBUG, "Proxy request granted"); return true; } else { logger(DEBUG_ALWAYS, LOG_DEBUG, "Proxy request rejected: %s", request + 9); return false; } } } int reqno = atoi(request); if(reqno || *request == '0') { if((reqno < 0) || (reqno >= LAST) || !request_handlers[reqno]) { logger(DEBUG_META, LOG_DEBUG, "Unknown request from %s (%s): %s", c->name, c->hostname, request); return false; } else { logger(DEBUG_META, LOG_DEBUG, "Got %s from %s (%s): %s", request_name[reqno], c->name, c->hostname, request); } if((c->allow_request != ALL) && (c->allow_request != reqno)) { logger(DEBUG_ALWAYS, LOG_ERR, "Unauthorized request from %s (%s)", c->name, c->hostname); return false; } if(!request_handlers[reqno](c, request)) { /* Something went wrong. Probably scriptkiddies. Terminate. */ if(reqno != TERMREQ) { logger(DEBUG_ALWAYS, LOG_ERR, "Error while processing %s from %s (%s)", request_name[reqno], c->name, c->hostname); } return false; } } else { logger(DEBUG_ALWAYS, LOG_ERR, "Bogus data received from %s (%s)", c->name, c->hostname); return false; } return true; } static int past_request_compare(const past_request_t *a, const past_request_t *b) { return strcmp(a->request, b->request); } static void free_past_request(past_request_t *r) { free((char *)r->request); free(r); } static timeout_t past_request_timeout; static void age_past_requests(void *data) { (void)data; int left = 0, deleted = 0; for splay_each(past_request_t, p, past_request_tree) { if(p->firstseen + pinginterval <= now.tv_sec) { splay_delete_node(past_request_tree, node), deleted++; } else { left++; } } if(left || deleted) { logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Aging past requests: deleted %d, left %d", deleted, left); } if(left) timeout_set(&past_request_timeout, &(struct timeval) { 10, rand() % 100000 }); } bool seen_request(const char *request) { past_request_t *new, p = {0}; p.request = request; if(splay_search(past_request_tree, &p)) { logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Already seen request"); return true; } else { new = xmalloc(sizeof(*new)); new->request = xstrdup(request); new->firstseen = now.tv_sec; splay_insert(past_request_tree, new); timeout_add(&past_request_timeout, age_past_requests, NULL, &(struct timeval) { 10, rand() % 100000 }); return false; } } void init_requests(void) { past_request_tree = splay_alloc_tree((splay_compare_t) past_request_compare, (splay_action_t) free_past_request); } void exit_requests(void) { splay_delete_tree(past_request_tree); timeout_del(&past_request_timeout); }