From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Mon, 11 May 2020 18:35:44 +0000 (-0500)
Subject: value: Don't zero out structures and then immdiately write data to them
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ad3d3db61a23232b45f2ce6fa1b882419d2129db;p=thirdparty%2Ffreeradius-server.git

value: Don't zero out structures and then immdiately write data to them

...and as for uninitialised fields in compound literals containing garbage, c99 states that shouldn't be the case.

http://c0x.coding-guidelines.com/6.7.8.html 1677.
---

diff --git a/src/lib/util/value.c b/src/lib/util/value.c
index c8efadddbcc..a7228594e87 100644
--- a/src/lib/util/value.c
+++ b/src/lib/util/value.c
@@ -1341,6 +1341,7 @@ ssize_t fr_value_box_from_network(TALLOC_CTX *ctx,
 				  bool tainted)
 {
 	uint8_t	const *p = src;
+	uint8_t const *end = p + len;
 	size_t	min, max;
 
 	min = fr_value_box_network_sizes[type][0];
@@ -1374,35 +1375,37 @@ ssize_t fr_value_box_from_network(TALLOC_CTX *ctx,
 	 *	Already in network byte order
 	 */
 	case FR_TYPE_IPV4_ADDR:
-		memset(&dst->vb_ip, 0, sizeof(dst->vb_ip));
-		memcpy(&dst->vb_ip.addr.v4, src, len);
-		dst->vb_ip.af = AF_INET;
-		dst->vb_ip.prefix = 32;
-		dst->vb_ip.scope_id = 0;	/* init even if it's unused */
+		dst->vb_ip = (fr_ipaddr_t){
+			.af = AF_INET,
+			.prefix = 32,
+		};
+		memcpy(&dst->vb_ip.addr.v4, p, (end - p));
 		break;
 
 	case FR_TYPE_IPV4_PREFIX:
-		memset(&dst->vb_ip, 0, sizeof(dst->vb_ip));
-		dst->vb_ip.af = AF_INET;
-		dst->vb_ip.prefix = *p++;
-		memcpy(&dst->vb_ip.addr.v4, p, sizeof(dst->vb_ip.addr.v4));
-		dst->vb_ip.scope_id = 0;	/* init even if it's unused */
+		dst->vb_ip = (fr_ipaddr_t){
+			.af = AF_INET,
+			.prefix = *p++,
+		};
+		memcpy(&dst->vb_ip.addr.v4, p, (end - p));
 		break;
 
 	case FR_TYPE_IPV6_ADDR:
-		memset(&dst->vb_ip, 0, sizeof(dst->vb_ip));
-		dst->vb_ip.af = AF_INET6;
-		dst->vb_ip.scope_id = len == max ? *p++ : 0;		/* optional */
-		memcpy(&dst->vb_ip.addr.v6, p, sizeof(dst->vb_ip.addr.v6));
-		dst->vb_ip.prefix = 128;
+		dst->vb_ip = (fr_ipaddr_t){
+			.af = AF_INET6,
+			.scope_id = len == max ? *p++ : 0, /* optional */
+			.prefix = 128
+		};
+		memcpy(&dst->vb_ip.addr.v6, p, (end - p));
 		break;
 
 	case FR_TYPE_IPV6_PREFIX:
-		memset(&dst->vb_ip, 0, sizeof(dst->vb_ip));
-		dst->vb_ip.af = AF_INET6;
-		dst->vb_ip.scope_id = len == max ? *p++ : 0;		/* optional */
-		dst->vb_ip.prefix = *p++;
-		memcpy(&dst->vb_ip.addr.v6, p, sizeof(dst->vb_ip.addr.v6));
+		dst->vb_ip = (fr_ipaddr_t){
+			.af = AF_INET6,
+			.scope_id = len == max ? *p++ : 0,
+			.prefix = *p++
+		};
+		memcpy(&dst->vb_ip.addr.v6, p, (end - p));
 		break;
 
 	case FR_TYPE_BOOL: