nfs: Fix misparsing of nfsv4 fs_locations attribute

The code incorrectly assumes here that the server name (or ip address)
is null-terminated.  This can cause referrals to fail in some cases.

Also support ipv6 addresses.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

3 files changed, 21 insertions, 29 deletions

diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 8d91bd88e310..5d2a5d3c4241 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -153,6 +153,7 @@ extern void nfs4_clear_inode(struct inode *);
 void nfs_zap_acl_cache(struct inode *inode);
 
 /* super.c */
+void nfs_parse_ip_address(char *, size_t, struct sockaddr *, size_t *);
 extern struct file_system_type nfs_xdev_fs_type;
 #ifdef CONFIG_NFS_V4
 extern struct file_system_type nfs4_xdev_fs_type;
@@ -276,6 +277,7 @@ unsigned int nfs_page_array_len(unsigned int base, size_t len)
                 PAGE_SIZE - 1) >> PAGE_SHIFT;
 }
 
+#define IPV6_SCOPE_DELIMITER    '%'
 
 /*
  * Set the port number in an address.  Be agnostic about the address
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index 6bcc5696f911..30befc39b3c6 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -93,50 +93,42 @@ static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
         return 0;
 }
 
-/*
- * Check if the string represents a "valid" IPv4 address
- */
-static inline int valid_ipaddr4(const char *buf)
-{
-        int rc, count, in[4];
-
-        rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
-        if (rc != 4)
-                return -EINVAL;
-        for (count = 0; count < 4; count++) {
-                if (in[count] > 255)
-                        return -EINVAL;
-        }
-        return 0;
-}
-
 static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
                                      char *page, char *page2,
                                      const struct nfs4_fs_location *location)
 {
         struct vfsmount *mnt = ERR_PTR(-ENOENT);
         char *mnt_path;
+        int page2len;
         unsigned int s;
 
         mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
         if (IS_ERR(mnt_path))
                 return mnt;
         mountdata->mnt_path = mnt_path;
+        page2 += strlen(mnt_path) + 1;
+        page2len = PAGE_SIZE - strlen(mnt_path) - 1;
 
         for (s = 0; s < location->nservers; s++) {
-                struct sockaddr_in addr = {
-                        .sin_family     = AF_INET,
-                        .sin_port       = htons(NFS_PORT),
-                };
+                const struct nfs4_string *buf = &location->servers[s];
+                struct sockaddr_storage addr;
 
-                if (location->servers[s].len <= 0 ||
-                    valid_ipaddr4(location->servers[s].data) < 0)
+                if (buf->len <= 0 || buf->len >= PAGE_SIZE)
                         continue;
 
-                mountdata->hostname = location->servers[s].data;
-                addr.sin_addr.s_addr = in_aton(mountdata->hostname),
                 mountdata->addr = (struct sockaddr *)&addr;
-                mountdata->addrlen = sizeof(addr);
+
+                if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
+                        continue;
+                nfs_parse_ip_address(buf->data, buf->len,
+                                mountdata->addr, &mountdata->addrlen);
+                if (mountdata->addr->sa_family == AF_UNSPEC)
+                        continue;
+                nfs_set_port(mountdata->addr, NFS_PORT);
+
+                strncpy(page2, buf->data, page2len);
+                page2[page2len] = '\0';
+                mountdata->hostname = page2;
 
                 snprintf(page, PAGE_SIZE, "%s:%s",
                                 mountdata->hostname,
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index b99096b8e827..20dc4ccdff56 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -716,8 +716,6 @@ static void nfs_parse_ipv4_address(char *string, size_t str_len,
         *addr_len = 0;
 }
 
-#define IPV6_SCOPE_DELIMITER    '%'
-
 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
 static void nfs_parse_ipv6_scope_id(const char *string, const size_t str_len,
                                     const char *delim,
@@ -790,7 +788,7 @@ static void nfs_parse_ipv6_address(char *string, size_t str_len,
  * 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,
+void nfs_parse_ip_address(char *string, size_t str_len,
                                  struct sockaddr *sap, size_t *addr_len)
 {
         unsigned int i, colons;