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

Chuck Lever
2010-01-15T22:55:52Z

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@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