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commit 4d2e67d6e5c910114dbccd17d9b93f06552c0024
Author: Florian Weimer <fweimer@redhat.com>
Date: Tue Aug 30 10:02:49 2022 +0200
resolv: Add internal __res_binary_hnok function
During package parsing, only the binary representation is available,
and it is convenient to check that directly for conformance with host
name requirements.
Reviewed-by: Siddhesh Poyarekar <siddhesh@sourceware.org>
(cherry picked from commit c79327bf00a4be6d60259227acc78ef80ead3622)
diff --git a/include/resolv.h b/include/resolv.h
index 3590b6f496d47710..4dbbac3800b7ef30 100644
--- a/include/resolv.h
+++ b/include/resolv.h
@@ -70,5 +70,8 @@ libc_hidden_proto (__libc_res_nameinquery)
extern __typeof (__res_queriesmatch) __libc_res_queriesmatch;
libc_hidden_proto (__libc_res_queriesmatch)
+/* Variant of res_hnok which operates on binary (but uncompressed) names. */
+bool __res_binary_hnok (const unsigned char *dn) attribute_hidden;
+
# endif /* _RESOLV_H_ && !_ISOMAC */
#endif
diff --git a/resolv/res-name-checking.c b/resolv/res-name-checking.c
index 2c603494fa3ca992..513ddb5f6b12ccb0 100644
--- a/resolv/res-name-checking.c
+++ b/resolv/res-name-checking.c
@@ -138,6 +138,12 @@ binary_leading_dash (const unsigned char *dn)
return dn[0] > 0 && dn[1] == '-';
}
+bool
+__res_binary_hnok (const unsigned char *dn)
+{
+ return !binary_leading_dash (dn) && binary_hnok (dn);
+}
+
/* Return 1 if res_hnok is a valid host name. Labels must only
contain [0-9a-zA-Z_-] characters, and the name must not start with
a '-'. The latter is to avoid confusion with program options. */
@@ -145,11 +151,9 @@ int
___res_hnok (const char *dn)
{
unsigned char buf[NS_MAXCDNAME];
- if (!printable_string (dn)
- || __ns_name_pton (dn, buf, sizeof (buf)) < 0
- || binary_leading_dash (buf))
- return 0;
- return binary_hnok (buf);
+ return (printable_string (dn)
+ && __ns_name_pton (dn, buf, sizeof (buf)) >= 0
+ && __res_binary_hnok (buf));
}
versioned_symbol (libc, ___res_hnok, res_hnok, GLIBC_2_34);
versioned_symbol (libc, ___res_hnok, __libc_res_hnok, GLIBC_PRIVATE);