From 953f5b4231bbbb8269bb0c55b96a1c8c4bb34a59 Mon Sep 17 00:00:00 2001
From: Guus Sliepen <guus@tinc-vpn.org>
Date: Sat, 6 Oct 2018 18:18:45 +0200
Subject: [PATCH] Fix warnings from the Clang static analyzer.

---
 configure.ac     |  1 +
 src/control.c    |  4 ++--
 src/invitation.c |  4 +++-
 src/net_setup.c  |  2 ++
 src/tincctl.c    | 13 ++++++++-----
 src/tincctl.h    |  2 +-
 src/xalloc.h     |  2 +-
 7 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/configure.ac b/configure.ac
index ca126408..3ad2821f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -181,6 +181,7 @@ AC_CHECK_HEADERS([netinet/tcp.h netinet/ip_icmp.h netinet/icmp6.h],
 
 dnl Checks for typedefs, structures, and compiler characteristics.
 tinc_ATTRIBUTE(__malloc__)
+tinc_ATTRIBUTE(__nonnull__)
 tinc_ATTRIBUTE(__warn_unused_result__)
 
 AC_CHECK_TYPES([struct ether_header, struct arphdr, struct ether_arp, struct ip, struct icmp, struct ip6_hdr, struct icmp6_hdr, struct nd_neighbor_solicit, struct nd_opt_hdr], , ,
diff --git a/src/control.c b/src/control.c
index beda6c41..71258b58 100644
--- a/src/control.c
+++ b/src/control.c
@@ -159,12 +159,12 @@ bool init_control(void) {
 	// Get the address and port of the first listening socket
 
 	char *localhost = NULL;
-	sockaddr_t sa;
+	sockaddr_t sa = {0};
 	socklen_t len = sizeof(sa);
 
 	// Make sure we have a valid address, and map 0.0.0.0 and :: to 127.0.0.1 and ::1.
 
-	if(getsockname(listen_socket[0].tcp.fd, (struct sockaddr *)&sa, &len)) {
+	if(getsockname(listen_socket[0].tcp.fd, &sa.sa, &len)) {
 		xasprintf(&localhost, "127.0.0.1 port %s", myport);
 	} else {
 		if(sa.sa.sa_family == AF_INET) {
diff --git a/src/invitation.c b/src/invitation.c
index 4c8597a6..c3072cf2 100644
--- a/src/invitation.c
+++ b/src/invitation.c
@@ -181,6 +181,7 @@ char *get_my_hostname() {
 	if(!tty) {
 		if(!hostname) {
 			fprintf(stderr, "Could not determine the external address or hostname. Please set Address manually.\n");
+			free(port);
 			return NULL;
 		}
 
@@ -199,6 +200,7 @@ again:
 	if(!fgets(line, sizeof(line), stdin)) {
 		fprintf(stderr, "Error while reading stdin: %s\n", strerror(errno));
 		free(hostname);
+		free(port);
 		return NULL;
 	}
 
@@ -644,7 +646,7 @@ static char *grep(const char *data, const char *var) {
 }
 
 static bool finalize_join(void) {
-	char *name = xstrdup(get_value(data, "Name"));
+	const char *name = get_value(data, "Name");
 
 	if(!name) {
 		fprintf(stderr, "No Name found in invitation!\n");
diff --git a/src/net_setup.c b/src/net_setup.c
index d8b3116b..d48c2299 100644
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -975,6 +975,7 @@ static bool setup_myself(void) {
 		myself->incipher = NULL;
 	} else if(!(myself->incipher = cipher_open_by_name(cipher))) {
 		logger(DEBUG_ALWAYS, LOG_ERR, "Unrecognized cipher type!");
+		free(cipher);
 		return false;
 	}
 
@@ -1002,6 +1003,7 @@ static bool setup_myself(void) {
 		myself->indigest = NULL;
 	} else if(!(myself->indigest = digest_open_by_name(digest, maclength))) {
 		logger(DEBUG_ALWAYS, LOG_ERR, "Unrecognized digest type!");
+		free(digest);
 		return false;
 	}
 
diff --git a/src/tincctl.c b/src/tincctl.c
index 2fdab2a6..4f6660a9 100644
--- a/src/tincctl.c
+++ b/src/tincctl.c
@@ -2151,7 +2151,7 @@ static bool try_bind(int port) {
 	return success;
 }
 
-int check_port(char *name) {
+int check_port(const char *name) {
 	if(try_bind(655)) {
 		return 655;
 	}
@@ -3175,10 +3175,7 @@ static int cmd_shell(int argc, char *argv[]) {
 			free(line);
 			rl_basic_word_break_characters = "\t\n ";
 			line = readline(prompt);
-
-			if(line) {
-				copy = xstrdup(line);
-			}
+			copy = line ? xstrdup(line) : NULL;
 		} else {
 			line = fgets(buf, sizeof(buf), stdin);
 		}
@@ -3224,6 +3221,9 @@ static int cmd_shell(int argc, char *argv[]) {
 		}
 
 		if(!strcasecmp(nargv[argc], "exit") || !strcasecmp(nargv[argc], "quit")) {
+#ifdef HAVE_READLINE
+			free(copy);
+#endif
 			free(nargv);
 			return result;
 		}
@@ -3252,6 +3252,9 @@ static int cmd_shell(int argc, char *argv[]) {
 		}
 	}
 
+#ifdef HAVE_READLINE
+	free(copy);
+#endif
 	free(nargv);
 
 	if(tty) {
diff --git a/src/tincctl.h b/src/tincctl.h
index db7f45a3..3f7d0037 100644
--- a/src/tincctl.h
+++ b/src/tincctl.h
@@ -48,7 +48,7 @@ extern char *get_my_name(bool verbose);
 extern bool connect_tincd(bool verbose);
 extern bool sendline(int fd, char *format, ...);
 extern bool recvline(int fd, char *line, size_t len);
-extern int check_port(char *name);
+extern int check_port(const char *name);
 extern FILE *fopenmask(const char *filename, const char *mode, mode_t perms);
 extern ecdsa_t *get_pubkey(FILE *f);
 
diff --git a/src/xalloc.h b/src/xalloc.h
index 493af5c0..ac24ebc6 100644
--- a/src/xalloc.h
+++ b/src/xalloc.h
@@ -53,7 +53,7 @@ static inline void *xrealloc(void *p, size_t n) {
 	return p;
 }
 
-static inline char *xstrdup(const char *s) __attribute__((__malloc__));
+static inline char *xstrdup(const char *s) __attribute__((__malloc__, __nonnull__));
 static inline char *xstrdup(const char *s) {
 	char *p = strdup(s);
 
-- 
2.20.1