lockd: Pass "struct sockaddr *" to new failover-by-IP function

Pass a more generic socket address type to nlmsvc_unlock_all_by_ip() to
allow for future support of IPv6.  Also provide additional sanity
checking in failover_unlock_ip() when constructing the server's IP
address.

As an added bonus, provide clean kerneldoc comments on related NLM
interfaces which were recently added.

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

1 files changed, 10 insertions, 5 deletions

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 2c2eb8796c10..1955a2702e60 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -310,9 +310,12 @@ static ssize_t write_getfd(struct file *file, char *buf, size_t size)
 
 static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size)
 {
-        __be32 server_ip;
-        char *fo_path, c;
+        struct sockaddr_in sin = {
+                .sin_family     = AF_INET,
+        };
         int b1, b2, b3, b4;
+        char c;
+        char *fo_path;
 
         /* sanity check */
         if (size == 0)
@@ -326,11 +329,13 @@ static ssize_t failover_unlock_ip(struct file *file, char *buf, size_t size)
                 return -EINVAL;
 
         /* get ipv4 address */
-        if (sscanf(fo_path, "%u.%u.%u.%u%c", &b1, &b2, &b3, &b4, &c) != 4)
+        if (sscanf(fo_path, NIPQUAD_FMT "%c", &b1, &b2, &b3, &b4, &c) != 4)
+                return -EINVAL;
+        if (b1 > 255 || b2 > 255 || b3 > 255 || b4 > 255)
                 return -EINVAL;
-        server_ip = htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
+        sin.sin_addr.s_addr = htonl((b1 << 24) | (b2 << 16) | (b3 << 8) | b4);
 
-        return nlmsvc_unlock_all_by_ip(server_ip);
+        return nlmsvc_unlock_all_by_ip((struct sockaddr *)&sin);
 }
 
 static ssize_t failover_unlock_fs(struct file *file, char *buf, size_t size)