NFS: Add string length argument to nfs_parse_server_address

To make nfs_parse_server_address() more generally useful, allow it to
accept input strings that are not terminated with '\0'.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 70 insertions, 30 deletions

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index ea4abd266a7..d27aa1db007 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -705,38 +705,76 @@ static int nfs_verify_server_address(struct sockaddr *addr)
         return 0;
 }
 
-/*
- * Parse string addresses passed in via a mount option,
- * and construct a sockaddr based on the result.
- *
- * If address parsing fails, set the sockaddr's address
- * family to AF_UNSPEC to force nfs_verify_server_address()
- * to punt the mount.
- */
-static void nfs_parse_server_address(char *value,
-                                     struct sockaddr *sap,
-                                     size_t *len)
+static void nfs_parse_ipv4_address(char *string, size_t str_len,
+                                   struct sockaddr *sap, size_t *addr_len)
 {
-        if (strchr(value, ':')) {
-                struct sockaddr_in6 *ap = (struct sockaddr_in6 *)sap;
-                u8 *addr = (u8 *)&ap->sin6_addr.in6_u;
+        struct sockaddr_in *sin = (struct sockaddr_in *)sap;
+        u8 *addr = (u8 *)&sin->sin_addr.s_addr;
 
-                ap->sin6_family = AF_INET6;
-                *len = sizeof(*ap);
-                if (in6_pton(value, -1, addr, '\0', NULL))
+        if (str_len <= INET_ADDRSTRLEN) {
+                dfprintk(MOUNT, "NFS: parsing IPv4 address %*s\n",
+                                (int)str_len, string);
+
+                sin->sin_family = AF_INET;
+                *addr_len = sizeof(*sin);
+                if (in4_pton(string, str_len, addr, '\0', NULL))
                         return;
-        } else {
-                struct sockaddr_in *ap = (struct sockaddr_in *)sap;
-                u8 *addr = (u8 *)&ap->sin_addr.s_addr;
+        }
+
+        sap->sa_family = AF_UNSPEC;
+        *addr_len = 0;
+}
+
+#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
+static void nfs_parse_ipv6_address(char *string, size_t str_len,
+                                   struct sockaddr *sap, size_t *addr_len)
+{
+        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
+        u8 *addr = (u8 *)&sin6->sin6_addr.in6_u;
+
+        if (str_len <= INET6_ADDRSTRLEN) {
+                dfprintk(MOUNT, "NFS: parsing IPv6 address %*s\n",
+                                (int)str_len, string);
 
-                ap->sin_family = AF_INET;
-                *len = sizeof(*ap);
-                if (in4_pton(value, -1, addr, '\0', NULL))
+                sin6->sin6_family = AF_INET6;
+                *addr_len = sizeof(*sin6);
+                if (in6_pton(string, str_len, addr, '\0', NULL))
                         return;
         }
 
         sap->sa_family = AF_UNSPEC;
-        *len = 0;
+        *addr_len = 0;
+}
+#else
+static void nfs_parse_ipv6_address(char *string, size_t str_len,
+                                   struct sockaddr *sap, size_t *addr_len)
+{
+        sap->sa_family = AF_UNSPEC;
+        *addr_len = 0;
+}
+#endif
+
+/*
+ * Construct a sockaddr based on the contents of a string that contains
+ * an IP address in presentation format.
+ *
+ * If there is a problem constructing the new sockaddr, set the address
+ * family to AF_UNSPEC.
+ */
+static void nfs_parse_ip_address(char *string, size_t str_len,
+                                 struct sockaddr *sap, size_t *addr_len)
+{
+        unsigned int i, colons;
+
+        colons = 0;
+        for (i = 0; i < str_len; i++)
+                if (string[i] == ':')
+                        colons++;
+
+        if (colons >= 2)
+                nfs_parse_ipv6_address(string, str_len, sap, addr_len);
+        else
+                nfs_parse_ipv4_address(string, str_len, sap, addr_len);
 }
 
 /*
@@ -1070,9 +1108,10 @@ static int nfs_parse_mount_options(char *raw,
                         string = match_strdup(args);
                         if (string == NULL)
                                 goto out_nomem;
-                        nfs_parse_server_address(string, (struct sockaddr *)
-                                                 &mnt->nfs_server.address,
-                                                 &mnt->nfs_server.addrlen);
+                        nfs_parse_ip_address(string, strlen(string),
+                                             (struct sockaddr *)
+                                                &mnt->nfs_server.address,
+                                             &mnt->nfs_server.addrlen);
                         kfree(string);
                         break;
                 case Opt_clientaddr:
@@ -1093,9 +1132,10 @@ static int nfs_parse_mount_options(char *raw,
                         string = match_strdup(args);
                         if (string == NULL)
                                 goto out_nomem;
-                        nfs_parse_server_address(string, (struct sockaddr *)
-                                                 &mnt->mount_server.address,
-                                                 &mnt->mount_server.addrlen);
+                        nfs_parse_ip_address(string, strlen(string),
+                                             (struct sockaddr *)
+                                                &mnt->mount_server.address,
+                                             &mnt->mount_server.addrlen);
                         kfree(string);
                         break;