X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fcontrol.c;h=738521425e4d3ea01b14042c73de9ba319d01110;hb=07a560eab66b575f382428a956550817697e25e2;hp=b72ea9eeb59778509c1aa8f368110163d8288928;hpb=01f47c46af514a9d7f39c143e4558a8426a0d3eb;p=tinc

diff --git a/src/control.c b/src/control.c
index b72ea9ee..73852142 100644
--- a/src/control.c
+++ b/src/control.c
@@ -24,93 +24,289 @@
 #include "system.h"
 #include "conf.h"
 #include "control.h"
+#include "control_common.h"
+#include "graph.h"
 #include "logger.h"
 #include "xalloc.h"
 
 static int control_socket = -1;
 static struct event control_event;
 static splay_tree_t *control_socket_tree;
-extern char *controlfilename;
+extern char *controlsocketname;
 
-static void handle_control_data(int fd, short events, void *event) {
-	char buf[MAXBUFSIZE];
-	size_t inlen;
+static void handle_control_data(struct bufferevent *event, void *data) {
+	tinc_ctl_request_t req;
+	tinc_ctl_request_t res;
+	struct evbuffer *res_data = NULL;
+	void *req_data;
 
-	inlen = read(fd, buf, sizeof buf);
+	if(EVBUFFER_LENGTH(event->input) < sizeof req)
+		return;
+
+	/* Copy the structure to ensure alignment */
+	memcpy(&req, EVBUFFER_DATA(event->input), sizeof req);
+
+	if(EVBUFFER_LENGTH(event->input) < req.length)
+		return;
+	req_data = EVBUFFER_DATA(event->input) + sizeof req;
+
+	if(req.length < sizeof req)
+		goto failure;
+
+	memset(&res, 0, sizeof res);
+	res.type = req.type;
+	res.id = req.id;
+
+	res_data = evbuffer_new();
+	if(res_data == NULL) {
+		res.res_errno = ENOMEM;
+		goto respond;
+	}
+
+	if(req.type == REQ_STOP) {
+		logger(LOG_NOTICE, "Got '%s' command", "stop");
+		event_loopexit(NULL);
+		goto respond;
+	}
+
+	if(req.type == REQ_DUMP_NODES) {
+		logger(LOG_NOTICE, "Got '%s' command", "dump nodes");
+		res.res_errno = dump_nodes(res_data);
+		goto respond;
+	}
+
+	if(req.type == REQ_DUMP_EDGES) {
+		logger(LOG_NOTICE, "Got '%s' command", "dump edges");
+		res.res_errno = dump_edges(res_data);
+		goto respond;
+	}
+
+	if(req.type == REQ_DUMP_SUBNETS) {
+		logger(LOG_NOTICE, "Got '%s' command", "dump subnets");
+		res.res_errno = dump_subnets(res_data);
+		goto respond;
+	}
 
-	if(inlen <= 0) {
-		logger(LOG_DEBUG, _("Closing control socket"));
-		event_del(event);
-		splay_delete(control_socket_tree, event);
-		close(fd);
+	if(req.type == REQ_DUMP_CONNECTIONS) {
+		logger(LOG_NOTICE, "Got '%s' command", "dump connections");
+		res.res_errno = dump_connections(res_data);
+		goto respond;
 	}
+
+	if(req.type == REQ_DUMP_GRAPH) {
+		logger(LOG_NOTICE, "Got '%s' command", "dump graph");
+		res.res_errno = dump_graph(res_data);
+		goto respond;
+	}
+
+	if(req.type == REQ_PURGE) {
+		logger(LOG_NOTICE, "Got '%s' command", "purge");
+		purge();
+		goto respond;
+	}
+
+	if(req.type == REQ_SET_DEBUG) {
+		debug_t new_debug_level;
+
+		logger(LOG_NOTICE, "Got '%s' command", "debug");
+		if(req.length != sizeof req + sizeof debug_level)
+			res.res_errno = EINVAL;
+		else {
+			memcpy(&new_debug_level, req_data, sizeof new_debug_level);
+			logger(LOG_NOTICE, "Changing debug level from %d to %d",
+				   debug_level, new_debug_level);
+			if(evbuffer_add_printf(res_data,
+								   "Changing debug level from %d to %d\n",
+								   debug_level, new_debug_level) == -1)
+				res.res_errno = errno;
+			debug_level = new_debug_level;
+		}
+		goto respond;
+	}
+
+	if(req.type == REQ_RETRY) {
+		logger(LOG_NOTICE, "Got '%s' command", "retry");
+		retry();
+		goto respond;
+	}
+
+	if(req.type == REQ_RELOAD) {
+		logger(LOG_NOTICE, "Got '%s' command", "reload");
+		res.res_errno = reload_configuration();
+		goto respond;
+	}
+
+	logger(LOG_DEBUG, "Malformed control command received");
+	res.res_errno = EINVAL;
+
+respond:
+	res.length = (sizeof res)
+				 + ((res_data == NULL) ? 0 : EVBUFFER_LENGTH(res_data));
+	evbuffer_drain(event->input, req.length);
+	if(bufferevent_write(event, &res, sizeof res) == -1)
+		goto failure;
+	if(res_data != NULL) {
+		if(bufferevent_write_buffer(event, res_data) == -1)
+			goto failure;
+		evbuffer_free(res_data);
+	}
+	return;
+
+failure:
+	logger(LOG_INFO, "Closing control socket on error");
+	evbuffer_free(res_data);
+	close(event->ev_read.ev_fd);
+	splay_delete(control_socket_tree, event);
+}
+
+static void handle_control_error(struct bufferevent *event, short what, void *data) {
+	if(what & EVBUFFER_EOF)
+		logger(LOG_DEBUG, "Control socket connection closed by peer");
+	else
+		logger(LOG_DEBUG, "Error while reading from control socket: %s", strerror(errno));
+
+	close(event->ev_read.ev_fd);
+	splay_delete(control_socket_tree, event);
 }
 
 static void handle_new_control_socket(int fd, short events, void *data) {
 	int newfd;
-	struct event *ev;
+	struct bufferevent *ev;
+	tinc_ctl_greeting_t greeting;
 
 	newfd = accept(fd, NULL, NULL);
 
 	if(newfd < 0) {
-		logger(LOG_ERR, _("Accepting a new connection failed: %s"), strerror(errno));
+		logger(LOG_ERR, "Accepting a new connection failed: %s", strerror(errno));
 		event_del(&control_event);
 		return;
 	}
 
-	ev = xmalloc(sizeof *ev);
-	event_set(ev, newfd, EV_READ | EV_PERSIST, handle_control_data, ev);
-	event_add(ev, NULL);
+	ev = bufferevent_new(newfd, handle_control_data, NULL, handle_control_error, NULL);
+	if(!ev) {
+		logger(LOG_ERR, "Could not create bufferevent for new control connection: %s", strerror(errno));
+		close(newfd);
+		return;
+	}
+
+	memset(&greeting, 0, sizeof greeting);
+	greeting.version = TINC_CTL_VERSION_CURRENT;
+	greeting.pid = getpid();
+	if(bufferevent_write(ev, &greeting, sizeof greeting) == -1) {
+		logger(LOG_ERR,
+			   "Cannot send greeting for new control connection: %s",
+			   strerror(errno));
+		bufferevent_free(ev);
+		close(newfd);
+		return;
+	}
+
+	bufferevent_enable(ev, EV_READ);
 	splay_insert(control_socket_tree, ev);
 
-	logger(LOG_DEBUG, _("Control socket connection accepted"));
+	logger(LOG_DEBUG, "Control socket connection accepted");
 }
 
 static int control_compare(const struct event *a, const struct event *b) {
 	return a < b ? -1 : a > b ? 1 : 0;
 }
 
-void init_control() {
+bool init_control() {
+	int result;
 	struct sockaddr_un addr;
+	char *lastslash;
 
-	control_socket_tree = splay_alloc_tree((splay_compare_t)control_compare, (splay_action_t)free);
-
-	if(strlen(controlfilename) >= sizeof addr.sun_path) {
-		logger(LOG_ERR, _("Control socket filename too long!"));
-		return;
+	if(strlen(controlsocketname) >= sizeof addr.sun_path) {
+		logger(LOG_ERR, "Control socket filename too long!");
+		goto bail;
 	}
 
 	memset(&addr, 0, sizeof addr);
 	addr.sun_family = AF_UNIX;
-	strncpy(addr.sun_path, controlfilename, sizeof addr.sun_path - 1);
+	strncpy(addr.sun_path, controlsocketname, sizeof addr.sun_path - 1);
 
 	control_socket = socket(PF_UNIX, SOCK_STREAM, 0);
 
 	if(control_socket < 0) {
-		logger(LOG_ERR, _("Creating UNIX socket failed: %s"), strerror(errno));
-		return;
+		logger(LOG_ERR, "Creating UNIX socket failed: %s", strerror(errno));
+		goto bail;
 	}
 
-	unlink(controlfilename);
-	if(bind(control_socket, (struct sockaddr *)&addr, sizeof addr) < 0) {
-		logger(LOG_ERR, _("Can't bind to %s: %s\n"), controlfilename, strerror(errno));
-		close(control_socket);
-		return;
+	/*
+	 * Restrict connections to our control socket by ensuring the parent
+	 * directory can be traversed only by root. Note this is not totally
+	 * race-free unless all ancestors are writable only by trusted users,
+	 * which we don't verify.
+	 */
+
+	struct stat statbuf;
+	lastslash = strrchr(controlsocketname, '/');
+	if(lastslash != NULL) {
+		*lastslash = 0; /* temporarily change controlsocketname to be dir */
+		if(mkdir(controlsocketname, 0700) < 0 && errno != EEXIST) {
+			logger(LOG_ERR, "Unable to create control socket directory %s: %s", controlsocketname, strerror(errno));
+			*lastslash = '/';
+			goto bail;
+		}
+
+		result = stat(controlsocketname, &statbuf);
+		*lastslash = '/';
+	} else
+		result = stat(".", &statbuf);
+
+	if(result < 0) {
+		logger(LOG_ERR, "Examining control socket directory failed: %s", strerror(errno));
+		goto bail;
+	}
+
+	if(statbuf.st_uid != 0 || (statbuf.st_mode & S_IXOTH) != 0 || (statbuf.st_gid != 0 && (statbuf.st_mode & S_IXGRP)) != 0) {
+		logger(LOG_ERR, "Control socket directory ownership/permissions insecure.");
+		goto bail;
+	}
+
+	result = bind(control_socket, (struct sockaddr *)&addr, sizeof addr);
+
+	if(result < 0 && errno == EADDRINUSE) {
+		result = connect(control_socket, (struct sockaddr *)&addr, sizeof addr);
+		if(result < 0) {
+			logger(LOG_WARNING, "Removing old control socket.");
+			unlink(controlsocketname);
+			result = bind(control_socket, (struct sockaddr *)&addr, sizeof addr);
+		} else {
+			if(netname)
+				logger(LOG_ERR, "Another tincd is already running for net `%s'.", netname);
+			else
+				logger(LOG_ERR, "Another tincd is already running.");
+			goto bail;
+		}
+	}
+
+	if(result < 0) {
+		logger(LOG_ERR, "Can't bind to %s: %s", controlsocketname, strerror(errno));
+		goto bail;
 	}
 
 	if(listen(control_socket, 3) < 0) {
-		logger(LOG_ERR, _("Can't listen on %s: %s\n"), controlfilename, strerror(errno));
-		close(control_socket);
-		return;
+		logger(LOG_ERR, "Can't listen on %s: %s", controlsocketname, strerror(errno));
+		goto bail;
 	}
 
+	control_socket_tree = splay_alloc_tree((splay_compare_t)control_compare, (splay_action_t)bufferevent_free);
+
 	event_set(&control_event, control_socket, EV_READ | EV_PERSIST, handle_new_control_socket, NULL);
 	event_add(&control_event, NULL);
-}
+	return true;
 
-void exit_control() {
-	if(control_socket >= 0) {
-		event_del(&control_event);
+bail:
+	if(control_socket != -1) {
 		close(control_socket);
+		control_socket = -1;
 	}
+	return false;
+}
+
+void exit_control() {
+	event_del(&control_event);
+	close(control_socket);
+	unlink(controlsocketname);
 }