X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol.c;h=d8b8867376d13c91c933c814091b036e89aec927;hb=refs%2Fheads%2F1.1;hp=de7f8b8760cb0bb96c40888b892d67c12f106b7e;hpb=228e7a5c8f0e517dcede50f886965a44fca39853;p=tinc

diff --git a/src/protocol.c b/src/protocol.c
index de7f8b87..bf165a7d 100644
--- a/src/protocol.c
+++ b/src/protocol.c
@@ -1,7 +1,7 @@
 /*
     protocol.c -- handle the meta-protocol, basic functions
-    Copyright (C) 1999-2005 Ivo Timmermans <ivo@tinc-vpn.org>,
-                  2000-2005 Guus Sliepen <guus@tinc-vpn.org>
+    Copyright (C) 1999-2005 Ivo Timmermans,
+                  2000-2022 Guus Sliepen <guus@tinc-vpn.org>
 
     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
@@ -13,17 +13,16 @@
     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.
-
-    $Id$
+    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 "crypto.h"
 #include "logger.h"
 #include "meta.h"
 #include "protocol.h"
@@ -31,223 +30,216 @@
 #include "xalloc.h"
 
 bool tunnelserver = false;
+bool strictsubnets = false;
+bool experimental = true;
 
-/* Jumptable for the request handlers */
-
-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,
-};
-
-/* Request names */
+static inline bool is_valid_request(request_t req) {
+	return req > ALL && req < LAST;
+}
 
-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",
-};
+/* Request handlers */
+const request_entry_t *get_request_entry(request_t req) {
+	if(!is_valid_request(req)) {
+		logger(DEBUG_ALWAYS, LOG_ERR, "Invalid request %d", req);
+		return NULL;
+	}
 
-static avl_tree_t *past_request_tree;
+	// Prevent user from accessing the table directly to always have bound checks
+	static const request_entry_t request_entries[] = {
+		[ID] = {id_h, "ID"},
+		[METAKEY] = {metakey_h, "METAKEY"},
+		[CHALLENGE] = {challenge_h, "CHALLENGE"},
+		[CHAL_REPLY] = {chal_reply_h, "CHAL_REPLY"},
+		[ACK] = {ack_h, "ACK"},
+		[STATUS] = {NULL, "STATUS"},
+		[ERROR] = {NULL, "ERROR"},
+		[TERMREQ] = {termreq_h, "TERMREQ"},
+		[PING] = {ping_h, "PING"},
+		[PONG] = {pong_h, "PONG"},
+		[ADD_SUBNET] = {add_subnet_h, "ADD_SUBNET"},
+		[DEL_SUBNET] = {del_subnet_h, "DEL_SUBNET"},
+		[ADD_EDGE] = {add_edge_h, "ADD_EDGE"},
+		[DEL_EDGE] = {del_edge_h, "DEL_EDGE"},
+		[KEY_CHANGED] = {key_changed_h, "KEY_CHANGED"},
+		[REQ_KEY] = {req_key_h, "REQ_KEY"},
+		[ANS_KEY] = {ans_key_h, "ANS_KEY"},
+		[PACKET] = {tcppacket_h, "PACKET"},
+		[CONTROL] = {control_h, "CONTROL"},
+		/* Not "real" requests yet */
+		[REQ_PUBKEY] = {NULL, "REQ_PUBKEY"},
+		[ANS_PUBKEY] = {NULL, "ANS_PUBKEY"},
+		[SPTPS_PACKET] = {sptps_tcppacket_h, "SPTPS_PACKET"},
+		[UDP_INFO] = {udp_info_h, "UDP_INFO"},
+		[MTU_INFO] = {mtu_info_h, "MTU_INFO"},
+	};
+	return &request_entries[req];
+}
 
-bool check_id(const char *id)
-{
-	for(; *id; id++)
-		if(!isalnum(*id) && *id != '_')
-			return false;
+static int past_request_compare(const past_request_t *a, const past_request_t *b) {
+	return strcmp(a->request, b->request);
+}
 
-	return true;
+static void free_past_request(past_request_t *r) {
+	if(r) {
+		free((char *)r->request);
+		free(r);
+	}
 }
 
+static splay_tree_t past_request_tree = {
+	.compare = (splay_compare_t) past_request_compare,
+	.delete = (splay_action_t) free_past_request,
+};
+
 /* Generic request routines - takes care of logging and error
    detection as well */
 
-bool send_request(connection_t *c, const char *format, ...)
-{
+bool send_request(connection_t *c, const char *format, ...) {
 	va_list args;
-	char buffer[MAXBUFSIZE];
-	int len, request;
+	char request[MAXBUFSIZE];
+	int len;
 
-	cp();
-
-	/* Use vsnprintf instead of vasprintf: faster, no memory
+	/* 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(buffer, MAXBUFSIZE, format, args);
+	len = vsnprintf(request, sizeof(request), format, args);
+	request[sizeof(request) - 1] = 0;
 	va_end(args);
 
-	if(len < 0 || len > MAXBUFSIZE - 1) {
-		logger(LOG_ERR, _("Output buffer overflow while sending request to %s (%s)"),
-			   c->name, c->hostname);
+	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;
 	}
 
-	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);
-	}
+	int id = atoi(request);
+	logger(DEBUG_META, LOG_DEBUG, "Sending %s to %s (%s): %s", get_request_entry(id)->name, c->name, c->hostname, request);
 
-	buffer[len++] = '\n';
+	request[len++] = '\n';
 
-	if(c == broadcast) {
-		broadcast_meta(NULL, buffer, len);
+	if(c == everyone) {
+		broadcast_meta(NULL, request, len);
 		return true;
-	} else
-		return send_meta(c, buffer, len);
-}
-
-void forward_request(connection_t *from)
-{
-	int request;
-
-	cp();
-
-	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);
+	} else {
+		if(id) {
+			return send_meta(c, request, len);
+		} else {
+			send_meta_raw(c, request, len);
+			return true;
+		}
 	}
+}
 
-	from->buffer[from->reqlen - 1] = '\n';
+void forward_request(connection_t *from, const char *request) {
+	logger(DEBUG_META, LOG_DEBUG, "Forwarding %s from %s (%s): %s", get_request_entry(atoi(request))->name, from->name, from->hostname, request);
 
-	broadcast_meta(from, from->buffer, from->reqlen);
+	// Create a temporary newline-terminated copy of the request
+	size_t len = strlen(request);
+	const size_t tmplen = len + 1;
+	char *tmp = alloca(tmplen);
+	memcpy(tmp, request, len);
+	tmp[len] = '\n';
+	broadcast_meta(from, tmp, tmplen);
 }
 
-bool receive_request(connection_t *c)
-{
-	int request;
+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;
+		}
 
-	cp();
+		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;
+			}
+		}
+	}
 
-	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);
+	int reqno = atoi(request);
 
+	if(reqno || *request == '0') {
+		if(!is_valid_request(reqno) || !get_request_entry(reqno)->handler) {
+			logger(DEBUG_META, LOG_DEBUG, "Unknown request from %s (%s): %s", c->name, c->hostname, request);
 			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);
+		const request_entry_t *entry = get_request_entry(reqno);
+		logger(DEBUG_META, LOG_DEBUG, "Got %s from %s (%s): %s", entry->name, 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[request](c)) {
+		if(!entry->handler(c, request)) {
 			/* Something went wrong. Probably scriptkiddies. Terminate. */
 
-			logger(LOG_ERR, _("Error while processing %s from %s (%s)"),
-				   request_name[request], c->name, c->hostname);
+			if(reqno != TERMREQ) {
+				logger(DEBUG_ALWAYS, LOG_ERR, "Error while processing %s from %s (%s)", entry->name, c->name, c->hostname);
+			}
+
 			return false;
 		}
 	} else {
-		logger(LOG_ERR, _("Bogus data received from %s (%s)"),
-			   c->name, c->hostname);
+		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)
-{
-	cp();
-
-	if(r->request)
-		free(r->request);
+static timeout_t past_request_timeout;
 
-	free(r);
-}
-
-void init_requests(void)
-{
-	cp();
+static void age_past_requests(void *data) {
+	(void)data;
+	int left = 0, deleted = 0;
 
-	past_request_tree = avl_alloc_tree((avl_compare_t) past_request_compare, (avl_action_t) free_past_request);
-}
+	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++;
+		}
+	}
 
-void exit_requests(void)
-{
-	cp();
+	if(left || deleted) {
+		logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Aging past requests: deleted %d, left %d", deleted, left);
+	}
 
-	avl_delete_tree(past_request_tree);
+	if(left)
+		timeout_set(&past_request_timeout, &(struct timeval) {
+		10, jitter()
+	});
 }
 
-bool seen_request(char *request)
-{
+bool seen_request(const char *request) {
 	past_request_t *new, p = {0};
 
-	cp();
-
 	p.request = request;
 
-	if(avl_search(past_request_tree, &p)) {
-		ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Already seen 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;
-		avl_insert(past_request_tree, new);
+		new->firstseen = now.tv_sec;
+		splay_insert(&past_request_tree, new);
+		timeout_add(&past_request_timeout, age_past_requests, NULL, &(struct timeval) {
+			10, jitter()
+		});
 		return false;
 	}
 }
 
-void age_past_requests(void)
-{
-	avl_node_t *node, *next;
-	past_request_t *p;
-	int left = 0, deleted = 0;
-
-	cp();
-
-	for(node = past_request_tree->head; node; node = next) {
-		next = node->next;
-		p = node->data;
-
-		if(p->firstseen + pinginterval < now)
-			avl_delete_node(past_request_tree, node), deleted++;
-		else
-			left++;
-	}
+void exit_requests(void) {
+	splay_empty_tree(&past_request_tree);
 
-	if(left || deleted)
-		ifdebug(SCARY_THINGS) logger(LOG_DEBUG, _("Aging past requests: deleted %d, left %d"),
-			   deleted, left);
+	timeout_del(&past_request_timeout);
 }