SUNRPC: Use rpc_pton() in ip_map_parse()

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.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 26 insertions, 21 deletions

diff --git a/net/sunrpc/svcauth_unix.c b/net/sunrpc/svcauth_unix.c
index d8c041114497..97f0e9e12024 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),