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

[Chuck Lever <chuck.lever@xxxxxxxxxx>]

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.

> > Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> > ---
> >
> > 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



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