From 9fc66e4dd966f18a8dbe7f251ab2a791dc8b8f23 Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sesse@google.com>
Date: Sat, 29 Sep 2007 13:52:14 +0000
Subject: [PATCH] Be stricter about what's a valid IP address in fake_hostent.
(Patch from the Google tree.)
---
ares/ares_gethostbyname.c | 22 +++++++++++++++++++++-
1 file changed, 21 insertions(+), 1 deletion(-)
diff --git a/ares/ares_gethostbyname.c b/ares/ares_gethostbyname.c
index 49ae53ed3b..7a4aad6e30 100644
--- a/ares/ares_gethostbyname.c
+++ b/ares/ares_gethostbyname.c
@@ -209,7 +209,27 @@ static int fake_hostent(const char *name, int family, ares_host_callback callbac
struct in6_addr in6;
if (family == AF_INET)
- result = ((in.s_addr = inet_addr(name)) == INADDR_NONE ? 0 : 1);
+ {
+ /* It only looks like an IP address if it's all numbers and dots. */
+ int numdots = 0;
+ const char *p;
+ for (p = name; *p; p++)
+ {
+ if (!isdigit(*p) && *p != '.') {
+ return 0;
+ } else if (*p == '.') {
+ numdots++;
+ }
+ }
+
+ /* if we don't have 3 dots, it is illegal
+ * (although inet_addr doesn't think so).
+ */
+ if (numdots != 3)
+ result = 0;
+ else
+ result = ((in.s_addr = inet_addr(name)) == INADDR_NONE ? 0 : 1);
+ }
else if (family == AF_INET6)
result = (ares_inet_pton(AF_INET6, name, &in6) < 1 ? 0 : 1);
--
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