wip: Build with -Wconversionlukeshu/safe-conversion

I think this found a real bug in the dhcp packet parser.

I don't think anything called lib9p_str{,n}() values that could be big
enough, but their bounds-checking was broken.

2 files changed, 12 insertions, 5 deletions

diff --git a/lib9p/tests/test_server/main.c b/lib9p/tests/test_server/main.c
index d7819eb..8490d62 100644
--- a/lib9p/tests/test_server/main.c
+++ b/lib9p/tests/test_server/main.c
@@ -151,7 +151,11 @@ int main(int argc, char *argv[]) {
 	if (argc != 3)
 		error(2, 0, "usage: %s PORT_NUMBER LOGFILE", argv[0]);
 
-	globals.port = atoi(argv[1]);
+	int _port = atoi(argv[1]);
+	if (_port == 0 || _port > UINT16_MAX)
+		error(2, 0, "usage: %s PORT_NUMBER LOGFILE", argv[0]);
+
+	globals.port = (uint16_t)_port;
 	globals.logstream = fopen(argv[2], "w");
 	if (!globals.logstream)
 		error(2, errno, "fopen");
diff --git a/lib9p/tests/testclient-sess.c b/lib9p/tests/testclient-sess.c
index 7cb7f97..3e2ba19 100644
--- a/lib9p/tests/testclient-sess.c
+++ b/lib9p/tests/testclient-sess.c
@@ -24,7 +24,7 @@ static void _send9p(int fd, struct lib9p_ctx *ctx, enum lib9p_msg_type typ, void
 	bool err = lib9p_Tmsg_marshal(ctx, typ, body, &buf);
 	assert(!err);
 	size_t exp = 0;
-	for (size_t i = 0; i < buf.iov_cnt; i++)
+	for (int i = 0; i < buf.iov_cnt; i++)
 		exp += buf.iov[i].iov_len;
 	ssize_t act = writev(fd, buf.iov, buf.iov_cnt);
 	if (act < 0)
@@ -42,7 +42,7 @@ static void _recv9p(int fd) {
 		ssize_t n = read(fd, &buf[done], goal-done);
 		if (n < 0)
 			error(1, errno, "read");
-		done += n;
+		done += (size_t)n;
 	}
 	goal = uint32le_decode(buf);
 	assert(goal <= MAX_MSG_SIZE);
@@ -50,7 +50,7 @@ static void _recv9p(int fd) {
 		ssize_t n = read(fd, &buf[done], goal-done);
 		if (n < 0)
 			error(1, errno, "read");
-		done += n;
+		done += (size_t)n;
 	}
 }
 
@@ -59,7 +59,10 @@ static void _recv9p(int fd) {
 int main(int argc, char *argv[]) {
 	if (argc != 2)
 		error(2, 0, "Usage: %s SERVER_PORT", argv[0]);
-	uint16_t server_port = atoi(argv[1]);
+	int _server_port = atoi(argv[1]);
+	if (_server_port == 0 || _server_port > UINT16_MAX)
+		error(2, 0, "Usage: %s SERVER_PORT", argv[0]);
+	uint16_t server_port = (uint16_t)_server_port;
 
 	union {
                 struct sockaddr         gen;