[PATCH 06/14] Cleanup: ensure string is 0 terminated

[Dirk Hohndel]

The Linux kernel uses the sir_name as a standard C string (in one
instance copying it into a 60 char buffer using kstrncpy with a length
limit of 60), we therefore need to ensure that it is 0 terminated.

Since the existing code didn't notify the caller if we were truncating
the string at 25 characters, I didn't add such a warning/error for
truncating at 24 characters.

I was not able to find documentation on how Windows uses irdaServiceName
so I didn't change that code.

In both cases I replaced the hardcoded length of 25 with a sizeof()
argument (but both Linux and Windows hard code that length in their
headers, so it seems unlikely this would ever change).

Coverity CID 207790

Signed-off-by: Dirk Hohndel <dirk at hohndel.org>
---
 src/irda.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/irda.c b/src/irda.c
index 149808aaa5c2..0ad227d70f40 100644
--- a/src/irda.c
+++ b/src/irda.c
@@ -222,17 +222,19 @@ dc_irda_connect_name (dc_iostream_t *abstract, unsigned int address, const char
 	peer.irdaDeviceID[2] = (address >> 16) & 0xFF;
 	peer.irdaDeviceID[3] = (address >> 24) & 0xFF;
     if (name)
-		strncpy (peer.irdaServiceName, name, 25);
+		strncpy (peer.irdaServiceName, name, sizeof(peer.irdaServiceName));
 	else
-		memset (peer.irdaServiceName, 0x00, 25);
+		memset (peer.irdaServiceName, 0x00, sizeof(peer.irdaServiceName));
 #else
 	struct sockaddr_irda peer;
 	peer.sir_family = AF_IRDA;
 	peer.sir_addr = address;
-	if (name)
-		strncpy (peer.sir_name, name, 25);
-	else
-		memset (peer.sir_name, 0x00, 25);
+	if (name) {
+		strncpy (peer.sir_name, name, sizeof(peer.sir_name) - 1);
+		peer.sir_name[sizeof(peer.sir_name) - 1] = '\0';
+	} else {
+		memset (peer.sir_name, 0x00, sizeof(peer.sir_name));
+	}
 #endif
 
 	return dc_socket_connect (&device->base, (struct sockaddr *) &peer, sizeof (peer));
-- 
2.15.1