X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Finvitation.c;h=cff9e7270c4606447d83c02af3423ce5068d700c;hb=0289162552cd85375605044c696e2a3294e7aa9a;hp=f2f4d76c148195dd7e6165bc387acea20d4cc1a6;hpb=6debc6c79ba385d35f646e0958f84ace5b8f4b4d;p=tinc

diff --git a/src/invitation.c b/src/invitation.c
index f2f4d76c..cff9e727 100644
--- a/src/invitation.c
+++ b/src/invitation.c
@@ -1,6 +1,6 @@
 /*
     invitation.c -- Create and accept invitations
-    Copyright (C) 2013-2017 Guus Sliepen <guus@tinc-vpn.org>
+    Copyright (C) 2013-2022 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
@@ -34,6 +34,8 @@
 #include "tincctl.h"
 #include "utils.h"
 #include "xalloc.h"
+#include "random.h"
+#include "pidfile.h"
 
 #include "ed25519/sha512.h"
 
@@ -79,8 +81,10 @@ static void scan_for_hostname(const char *filename, char **hostname, char **port
 		p[strcspn(p, "\t ")] = 0;
 
 		if(!*port && !strcasecmp(line, "Port")) {
+			free(*port);
 			*port = xstrdup(q);
 		} else if(!*hostname && !strcasecmp(line, "Address")) {
+			free(*hostname);
 			*hostname = xstrdup(q);
 
 			if(*p) {
@@ -97,7 +101,7 @@ static void scan_for_hostname(const char *filename, char **hostname, char **port
 	fclose(f);
 }
 
-char *get_my_hostname() {
+static bool get_my_hostname(char **out_address, char **out_port) {
 	char *hostname = NULL;
 	char *port = NULL;
 	char *hostport = NULL;
@@ -114,6 +118,19 @@ char *get_my_hostname() {
 	free(name);
 	name = NULL;
 
+	if(!port || (is_decimal(port) && atoi(port) == 0)) {
+		pidfile_t *pidfile = read_pidfile();
+
+		if(pidfile) {
+			free(port);
+			port = xstrdup(pidfile->port);
+			free(pidfile);
+		} else {
+			fprintf(stderr, "tincd is using a dynamic port and is not running. Please start tincd or set the Port option to a non-zero value.\n");
+			goto exit;
+		}
+	}
+
 	if(hostname) {
 		goto done;
 	}
@@ -185,7 +202,7 @@ char *get_my_hostname() {
 		if(!hostname) {
 			fprintf(stderr, "Could not determine the external address or hostname. Please set Address manually.\n");
 			free(port);
-			return NULL;
+			return false;
 		}
 
 		goto save;
@@ -204,7 +221,7 @@ again:
 		fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
 		free(hostname);
 		free(port);
-		return NULL;
+		return false;
 	}
 
 	if(!rstrip(line)) {
@@ -256,12 +273,25 @@ done:
 		}
 	}
 
+exit:
 	free(hostname);
+
+	if(hostport && port) {
+		*out_address = hostport;
+		*out_port = port;
+		return true;
+	}
+
+	free(hostport);
 	free(port);
-	return hostport;
+	return false;
 }
 
-static bool fcopy(FILE *out, const char *filename) {
+// Copy host configuration file, replacing Port with the value passed here. Host
+// configs may contain this clause: `Port = 0`, which means 'ask the operating
+// system to allocate any available port'. This obviously won't do for invitation
+// files, so replace it with an actual port we've obtained previously.
+static bool copy_config_replacing_port(FILE *out, const char *filename, const char *port) {
 	FILE *in = fopen(filename, "r");
 
 	if(!in) {
@@ -269,17 +299,33 @@ static bool fcopy(FILE *out, const char *filename) {
 		return false;
 	}
 
-	char buf[1024];
-	size_t len;
+	char line[1024];
 
-	while((len = fread(buf, 1, sizeof(buf), in))) {
-		fwrite(buf, len, 1, out);
+	while(fgets(line, sizeof(line), in)) {
+		const char *var_beg = line + strspn(line, "\t ");
+		const char *var_end = var_beg + strcspn(var_beg, "\t ");
+
+		// Check the name of the variable we've read. If it's Port, replace it with
+		// a port we'll use in invitation URL. Otherwise, just copy the line.
+		if(var_end > var_beg && !strncasecmp(var_beg, "Port", var_end - var_beg)) {
+			fprintf(out, "Port = %s\n", port);
+		} else {
+			fprintf(out, "%s", line);
+		}
 	}
 
 	fclose(in);
 	return true;
 }
 
+static bool append_host_config(FILE *f, const char *nodename, const char *port) {
+	char path[PATH_MAX];
+	snprintf(path, sizeof(path), "%s" SLASH "hosts" SLASH "%s", confbase, nodename);
+	bool success = copy_config_replacing_port(f, path, port);
+	fclose(f);
+	return success;
+}
+
 int cmd_invite(int argc, char *argv[]) {
 	if(argc < 2) {
 		fprintf(stderr, "Not enough arguments!\n");
@@ -457,11 +503,13 @@ int cmd_invite(int argc, char *argv[]) {
 	randomize(cookie, 18);
 
 	// Create a filename that doesn't reveal the cookie itself
-	uint8_t buf[18 + strlen(fingerprint)];
+	const size_t buflen = 18 + strlen(fingerprint);
+	uint8_t *buf = alloca(buflen);
+
 	char cookiehash[64];
 	memcpy(buf, cookie, 18);
-	memcpy(buf + 18, fingerprint, sizeof(buf) - 18);
-	sha512(buf, sizeof(buf), cookiehash);
+	memcpy(buf + 18, fingerprint, buflen - 18);
+	sha512(buf, buflen, cookiehash);
 	b64encode_tinc_urlsafe(cookiehash, cookiehash, 18);
 
 	free(fingerprint);
@@ -484,7 +532,12 @@ int cmd_invite(int argc, char *argv[]) {
 	}
 
 	// Get the local address
-	char *address = get_my_hostname();
+	char *address = NULL;
+	char *port = NULL;
+
+	if(!get_my_hostname(&address, &port)) {
+		return 1;
+	}
 
 	// Fill in the details.
 	fprintf(f, "Name = %s\n", argv[1]);
@@ -519,10 +572,14 @@ int cmd_invite(int argc, char *argv[]) {
 	fprintf(f, "#---------------------------------------------------------------#\n");
 	fprintf(f, "Name = %s\n", myname);
 
-	char filename2[PATH_MAX];
-	snprintf(filename2, sizeof(filename2), "%s" SLASH "hosts" SLASH "%s", confbase, myname);
-	fcopy(f, filename2);
-	fclose(f);
+	bool appended = append_host_config(f, myname, port);
+	free(port);
+
+	if(!appended) {
+		fprintf(stderr, "Could not append my config to invitation file: %s.\n", strerror(errno));
+		free(address);
+		return 1;
+	}
 
 	// Create an URL from the local address, key hash and cookie
 	char *url;
@@ -545,15 +602,13 @@ int cmd_invite(int argc, char *argv[]) {
 }
 
 static int sock;
-static char cookie[18];
+static char cookie[18], hash[18];
 static sptps_t sptps;
 static char *data;
 static size_t datalen;
 static bool success = false;
 
-static char cookie[18], hash[18];
-
-static char *get_line(const char **data) {
+static char *get_line(char *line, size_t linelen, const char **data) {
 	if(!data || !*data) {
 		return NULL;
 	}
@@ -563,11 +618,10 @@ static char *get_line(const char **data) {
 		return NULL;
 	}
 
-	static char line[1024];
 	const char *end = strchr(*data, '\n');
 	size_t len = end ? (size_t)(end - *data) : strlen(*data);
 
-	if(len >= sizeof(line)) {
+	if(len >= linelen) {
 		fprintf(stderr, "Maximum line length exceeded!\n");
 		return NULL;
 	}
@@ -589,7 +643,9 @@ static char *get_line(const char **data) {
 }
 
 static char *get_value(const char *data, const char *var) {
-	char *line = get_line(&data);
+	static char buf[1024];
+
+	char *line = get_line(buf, sizeof(buf), &data);
 
 	if(!line) {
 		return NULL;
@@ -656,29 +712,28 @@ static char *grep(const char *data, const char *var) {
 }
 
 static bool finalize_join(void) {
-	const char *temp_name = get_value(data, "Name");
+	const char *name = get_value(data, "Name");
 
-	if(!temp_name) {
+	if(!name) {
 		fprintf(stderr, "No Name found in invitation!\n");
 		return false;
 	}
 
-	size_t len = strlen(temp_name);
-	char name[len + 1];
-	memcpy(name, temp_name, len);
-	name[len] = 0;
-
 	if(!check_id(name)) {
 		fprintf(stderr, "Invalid Name found in invitation!\n");
 		return false;
 	}
 
 	if(!netname) {
-		netname = xstrdup(grep(data, "NetName"));
+		const char *net = grep(data, "NetName");
 
-		if(netname && !check_netname(netname, true)) {
-			fprintf(stderr, "Unsafe NetName found in invitation!\n");
-			return false;
+		if(net) {
+			netname = xstrdup(net);
+
+			if(!check_netname(netname, true)) {
+				fprintf(stderr, "Unsafe NetName found in invitation!\n");
+				return false;
+			}
 		}
 	}
 
@@ -774,7 +829,9 @@ make_names:
 	const char *p = data;
 	char *l, *value;
 
-	while((l = get_line(&p))) {
+	static char line[1024];
+
+	while((l = get_line(line, sizeof(line), &p))) {
 		// Ignore comments
 		if(*l == '#') {
 			continue;
@@ -881,7 +938,7 @@ make_names:
 			return false;
 		}
 
-		while((l = get_line(&p))) {
+		while((l = get_line(line, sizeof(line), &p))) {
 			if(!strcmp(l, "#---------------------------------------------------------------#")) {
 				continue;
 			}
@@ -998,7 +1055,7 @@ ask_netname:
 	char filename2[PATH_MAX];
 	snprintf(filename, sizeof(filename), "%s" SLASH "tinc-up.invitation", confbase);
 
-#ifdef HAVE_MINGW
+#ifdef HAVE_WINDOWS
 	snprintf(filename2, sizeof(filename2), "%s" SLASH "tinc-up.bat", confbase);
 #else
 	snprintf(filename2, sizeof(filename2), "%s" SLASH "tinc-up", confbase);
@@ -1030,7 +1087,7 @@ ask_netname:
 
 				if(response == 'e') {
 					char *command;
-#ifndef HAVE_MINGW
+#ifndef HAVE_WINDOWS
 					const char *editor = getenv("VISUAL");
 
 					if(!editor) {
@@ -1087,7 +1144,7 @@ ask_netname:
 static bool invitation_send(void *handle, uint8_t type, const void *vdata, size_t len) {
 	(void)handle;
 	(void)type;
-	const uint8_t *data = vdata;
+	const char *data = vdata;
 
 	while(len) {
 		ssize_t result = send(sock, data, len, 0);
@@ -1227,7 +1284,8 @@ int cmd_join(int argc, char *argv[]) {
 	}
 
 	if(!port || !*port) {
-		port = "655";
+		static char default_port[] = "655";
+		port = default_port;
 	}
 
 	if(!b64decode_tinc(slash, hash, 24) || !b64decode_tinc(slash + 24, cookie, 24)) {
@@ -1359,7 +1417,7 @@ next:
 				continue;
 			}
 
-#if HAVE_MINGW
+#if HAVE_WINDOWS
 
 			// If socket has been shut down, recv() on Windows returns -1 and sets sockerrno
 			// to WSAESHUTDOWN, while on UNIX-like operating systems recv() returns 0, so we