NLM: nlm_privileged_requester() doesn't recognize mapped loopback address

Commit b85e4676 added the nlm_privileged_requester() helper to check
whether an RPC request was sent from a local privileged caller.  It
recognizes IPv4 privileged callers (from "127.0.0.1"), and IPv6
privileged callers (from "::1").

However, IPV6_ADDR_LOOPBACK is not set for the mapped IPv4 loopback
address (::ffff:7f00:0001), so the test breaks when the kernel's RPC
service is IPv6-enabled but user space is calling via the IPv4
loopback address.  This is actually the most common case for IPv6-
enabled RPC services on Linux.

Rewrite the IPv6 check to handle the mapped IPv4 loopback address as
well as a normal IPv6 loopback address.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
Chuck Lever 2008-12-11 17:56:44 -05:00 committed by J. Bruce Fields
parent 49b5699b3f
commit d1208f7073

View file

@ -299,8 +299,14 @@ static inline int __nlm_privileged_request4(const struct sockaddr *sap)
static inline int __nlm_privileged_request6(const struct sockaddr *sap)
{
const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
return (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK) &&
(ntohs(sin6->sin6_port) < 1024);
if (ntohs(sin6->sin6_port) > 1023)
return 0;
if (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_MAPPED)
return ipv4_is_loopback(sin6->sin6_addr.s6_addr32[3]);
return ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK;
}
#else /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
static inline int __nlm_privileged_request6(const struct sockaddr *sap)