Re: getaddrinfo usage with wrong ip family

[Julien Ramseier <j.ramseier@gmail.com>]

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> Le 22 sept. 2015 à 17:16, Rich Felker <dalias@libc.org> a écrit :
> 
> Another approach might be having __lookup_numeric always parse with
> AF_UNSPEC, but return error rather than 0 results if the resulting
> family does not match the requested family.

This seems the simplest solution in the meantime.

Here’s the patch I applied to my trunk.



—
Julien

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diff --git a/src/network/lookup_ipliteral.c b/src/network/lookup_ipliteral.c
index 7bcb85f..209dc55 100644
--- a/src/network/lookup_ipliteral.c
+++ b/src/network/lookup_ipliteral.c
@@ -15,38 +15,43 @@ int __lookup_ipliteral(struct address buf[static 1], const char *name, int famil
 {
 	struct in_addr a4;
 	struct in6_addr a6;
-	if (family != AF_INET6 && __inet_aton(name, &a4)>0) {
+	if (__inet_aton(name, &a4) > 0) {
+		if (family == AF_INET6) /* wrong family */
+			return EAI_NONAME;
 		memcpy(&buf[0].addr, &a4, sizeof a4);
 		buf[0].family = AF_INET;
 		buf[0].scopeid = 0;
 		return 1;
 	}
-	if (family != AF_INET) {
-		char tmp[64];
-		char *p = strchr(name, '%'), *z;
-		unsigned long long scopeid;
-		if (p && p-name < 64) {
-			memcpy(tmp, name, p-name);
-			tmp[p-name] = 0;
-			name = tmp;
-		}
-		if (inet_pton(AF_INET6, name, &a6)<=0) return 0;
-		memcpy(&buf[0].addr, &a6, sizeof a6);
-		buf[0].family = AF_INET6;
-		if (p) {
-			if (isdigit(*++p)) scopeid = strtoull(p, &z, 10);
-			else z = p-1;
-			if (*z) {
-				if (!IN6_IS_ADDR_LINKLOCAL(&a6) &&
-				    !IN6_IS_ADDR_MC_LINKLOCAL(&a6))
-					return EAI_NONAME;
-				scopeid = if_nametoindex(p);
-				if (!scopeid) return EAI_NONAME;
-			}
-			if (scopeid > UINT_MAX) return EAI_NONAME;
-			buf[0].scopeid = scopeid;
+
+	char tmp[64];
+	char *p = strchr(name, '%'), *z;
+	unsigned long long scopeid;
+	if (p && p-name < 64) {
+		memcpy(tmp, name, p-name);
+		tmp[p-name] = 0;
+		name = tmp;
+	}
+
+	if (inet_pton(AF_INET6, name, &a6) <= 0)
+		return 0;
+	if (family == AF_INET) /* wrong family */
+		return EAI_NONAME;
+
+	memcpy(&buf[0].addr, &a6, sizeof a6);
+	buf[0].family = AF_INET6;
+	if (p) {
+		if (isdigit(*++p)) scopeid = strtoull(p, &z, 10);
+		else z = p-1;
+		if (*z) {
+			if (!IN6_IS_ADDR_LINKLOCAL(&a6) &&
+			    !IN6_IS_ADDR_MC_LINKLOCAL(&a6))
+				return EAI_NONAME;
+			scopeid = if_nametoindex(p);
+			if (!scopeid) return EAI_NONAME;
 		}
-		return 1;
+		if (scopeid > UINT_MAX) return EAI_NONAME;
+		buf[0].scopeid = scopeid;
 	}
-	return 0;
+	return 1;
 }

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