lib/util: let is_ipaddress_v6() cope with "fe80::1234%3"

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

1 files changed, 54 insertions, 12 deletions

diff --git a/lib/util/util_net.c b/lib/util/util_net.c
index 83afda4c78..d58855da5b 100644
--- a/lib/util/util_net.c
+++ b/lib/util/util_net.c
@@ -330,28 +330,70 @@ bool is_ipaddress_v6(const char *str)
 	int ret = -1;
 
 	if (strchr_m(str, ':')) {
-		char addr[INET6_ADDRSTRLEN];
-		struct in6_addr dest6;
-		const char *sp = str;
+		char buf[INET6_ADDRSTRLEN] = { 0, };
+		size_t len;
+		const char *addr = str;
+		const char *idxs = NULL;
+		unsigned int idx = 0;
+		struct in6_addr ip6;
 		char *p = strchr_m(str, '%');
 
+		if (p && (p > str)) {
+			len = PTR_DIFF(p, str);
+			idxs = p + 1;
+		} else {
+			len = strlen(str);
+		}
+
+		if (len >= sizeof(buf)) {
+			return false;
+		}
+		if (idxs != NULL) {
+			strncpy(buf, str, len);
+			addr = buf;
+		}
+
+		/*
+		 * Cope with link-local.
+		 * This is IP:v6:addr%ifidx.
+		 */
+		if (idxs != NULL) {
+			char c;
+
+			ret = sscanf(idxs, "%5u%c", &idx, &c);
+			if (ret != 1) {
+				idx = 0;
+			}
+
+			if (idx > 0 && idx < UINT16_MAX) {
+				/* a valid index */
+				idxs = NULL;
+			}
+		}
+
 		/*
 		 * Cope with link-local.
 		 * This is IP:v6:addr%ifname.
 		 */
+		if (idxs != NULL) {
+			idx = if_nametoindex(idxs);
 
-		if (p && (p > str) && (if_nametoindex(p+1) != 0)) {
-			size_t len = MIN(PTR_DIFF(p,str)+1, sizeof(addr));
-			if (strlcpy(addr, str, len) >= len) {
-				/* Truncate. */
-				return false;
+			if (idx > 0) {
+				/* a valid index */
+				idxs = NULL;
 			}
-			sp = addr;
 		}
-		ret = inet_pton(AF_INET6, sp, &dest6);
-		if (ret > 0) {
-			return true;
+
+		if (idxs != NULL) {
+			return false;
+		}
+
+		ret = inet_pton(AF_INET6, addr, &ip6);
+		if (ret <= 0) {
+			return false;
 		}
+
+		return true;
 	}
 #endif
 	return false;