Re: [PATCH 1/3] SUNRPC: Use rpc_pton() in ip_map_parse()

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Jan 15, 2010 at 05:55:09PM -0500, Chuck Lever wrote:
> On Jan 15, 2010, at 5:25 PM, J. Bruce Fields wrote:
>> On Wed, Jan 13, 2010 at 04:10:31PM -0500, Chuck Lever wrote:
>>> The existing logic in ip_map_parse() can not currently parse
>>> shorthanded IPv6 addresses (anything with a double colon), nor can
>>> it parse an IPv6 presentation address with a scope ID.  An
>>> IPv6-enabled mountd can pass down both.
>>
>> Why does mountd need to be able to do that?
>
> AFAICT, the glibc APIs (like inet_ntop(3) and getnameinfo(3)) provide no 
> way to disable shorthanding.
>
> Since we have kernel support for it now, it makes sense to me to allow  
> the kernel to accept a broader range of valid presentation address  
> formats.

OK.  I can live with that.--b.

>
>>> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
>>> ---
>>>
>>> net/sunrpc/svcauth_unix.c |   47 ++++++++++++++++++++++++ 
>>> +--------------------
>>> 1 files changed, 26 insertions(+), 21 deletions(-)
>>>
>>> diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
>>> index d8c0411..97f0e9e 100644
>>> --- a/net/sunrpc/svcauth_unix.c
>>> +++ b/net/sunrpc/svcauth_unix.c
>>> @@ -15,6 +15,7 @@
>>> #include <linux/kernel.h>
>>> #define RPCDBG_FACILITY	RPCDBG_AUTH
>>>
>>> +#include <linux/sunrpc/clnt.h>
>>>
>>> /*
>>>  * AUTHUNIX and AUTHNULL credentials are both handled here.
>>> @@ -187,10 +188,13 @@ static int ip_map_parse(struct cache_detail  
>>> *cd,
>>> 	 * for scratch: */
>>> 	char *buf = mesg;
>>> 	int len;
>>> -	int b1, b2, b3, b4, b5, b6, b7, b8;
>>> -	char c;
>>> 	char class[8];
>>> -	struct in6_addr addr;
>>> +	union {
>>> +		struct sockaddr		sa;
>>> +		struct sockaddr_in	s4;
>>> +		struct sockaddr_in6	s6;
>>> +	} address;
>>> +	struct sockaddr_in6 sin6;
>>> 	int err;
>>>
>>> 	struct ip_map *ipmp;
>>> @@ -209,24 +213,24 @@ static int ip_map_parse(struct cache_detail  
>>> *cd,
>>> 	len = qword_get(&mesg, buf, mlen);
>>> 	if (len <= 0) return -EINVAL;
>>>
>>> -	if (sscanf(buf, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) == 4) {
>>> -		addr.s6_addr32[0] = 0;
>>> -		addr.s6_addr32[1] = 0;
>>> -		addr.s6_addr32[2] = htonl(0xffff);
>>> -		addr.s6_addr32[3] =
>>> -			htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
>>> -       } else if (sscanf(buf, "%04x:%04x:%04x:%04x:%04x:%04x:%04x: 
>>> %04x%c",
>>> -			&b1, &b2, &b3, &b4, &b5, &b6, &b7, &b8, &c) == 8) {
>>> -		addr.s6_addr16[0] = htons(b1);
>>> -		addr.s6_addr16[1] = htons(b2);
>>> -		addr.s6_addr16[2] = htons(b3);
>>> -		addr.s6_addr16[3] = htons(b4);
>>> -		addr.s6_addr16[4] = htons(b5);
>>> -		addr.s6_addr16[5] = htons(b6);
>>> -		addr.s6_addr16[6] = htons(b7);
>>> -		addr.s6_addr16[7] = htons(b8);
>>> -       } else
>>> +	if (rpc_pton(buf, len, &address.sa, sizeof(address)) == 0)
>>> 		return -EINVAL;
>>> +	switch (address.sa.sa_family) {
>>> +	case AF_INET:
>>> +		/* Form a mapped IPv4 address in sin6 */
>>> +		memset(&sin6, 0, sizeof(sin6));
>>> +		sin6.sin6_family = AF_INET6;
>>> +		sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
>>> +		sin6.sin6_addr.s6_addr32[3] = address.s4.sin_addr.s_addr;
>>> +		break;
>>> +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
>>> +	case AF_INET6:
>>> +		memcpy(&sin6, &address.s6, sizeof(sin6));
>>> +		break;
>>> +#endif
>>> +	default:
>>> +		return -EINVAL;
>>> +	}
>>>
>>> 	expiry = get_expiry(&mesg);
>>> 	if (expiry ==0)
>>> @@ -243,7 +247,8 @@ static int ip_map_parse(struct cache_detail *cd,
>>> 	} else
>>> 		dom = NULL;
>>>
>>> -	ipmp = ip_map_lookup(class, &addr);
>>> +	/* IPv6 scope IDs are ignored for now */
>>> +	ipmp = ip_map_lookup(class, &sin6.sin6_addr);
>>> 	if (ipmp) {
>>> 		err = ip_map_update(ipmp,
>>> 			     container_of(dom, struct unix_domain, h),
>>>
>> --
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>
> --
> Chuck Lever
> chuck[dot]lever[at]oracle[dot]com
>
>
>