NLM: allow lockd requests from an unprivileged port

If the admin has specified the "noresvport" option for an NFS mount
point, the kernel's NFS client uses an unprivileged source port for
the main NFS transport.  The kernel's lockd client should use an
unprivileged port in this case as well.

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

2 files changed, 10 insertions, 2 deletions

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 94d42cc4e393..1f3b0fc0d351 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -61,7 +61,7 @@ struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init)
 
         host = nlmclnt_lookup_host(nlm_init->address, nlm_init->addrlen,
                                    nlm_init->protocol, nlm_version,
-                                   nlm_init->hostname);
+                                   nlm_init->hostname, nlm_init->noresvport);
         if (host == NULL) {
                 lockd_down();
                 return ERR_PTR(-ENOLCK);
diff --git a/fs/lockd/host.c b/fs/lockd/host.c
index 70fc63a1727b..acc2aa5021d1 100644
--- a/fs/lockd/host.c
+++ b/fs/lockd/host.c
@@ -48,6 +48,7 @@ struct nlm_lookup_host_info {
         const size_t            hostname_len;   /* it's length */
         const struct sockaddr   *src_sap;       /* our address (optional) */
         const size_t            src_len;        /* it's length */
+        const int               noresvport;     /* use non-priv port */
 };
 
 /*
@@ -222,6 +223,7 @@ static struct nlm_host *nlm_lookup_host(struct nlm_lookup_host_info *ni)
         host->h_nsmstate   = 0;                 /* real NSM state */
         host->h_nsmhandle  = nsm;
         host->h_server     = ni->server;
+        host->h_noresvport = ni->noresvport;
         hlist_add_head(&host->h_hash, chain);
         INIT_LIST_HEAD(&host->h_lockowners);
         spin_lock_init(&host->h_lock);
@@ -272,6 +274,7 @@ nlm_destroy_host(struct nlm_host *host)
  * @protocol: transport protocol to use
  * @version: NLM protocol version
  * @hostname: '\0'-terminated hostname of server
+ * @noresvport: 1 if non-privileged port should be used
  *
  * Returns an nlm_host structure that matches the passed-in
  * [server address, transport protocol, NLM version, server hostname].
@@ -281,7 +284,9 @@ nlm_destroy_host(struct nlm_host *host)
 struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
                                      const size_t salen,
                                      const unsigned short protocol,
-                                     const u32 version, const char *hostname)
+                                     const u32 version,
+                                     const char *hostname,
+                                     int noresvport)
 {
         const struct sockaddr source = {
                 .sa_family      = AF_UNSPEC,
@@ -296,6 +301,7 @@ struct nlm_host *nlmclnt_lookup_host(const struct sockaddr *sap,
                 .hostname_len   = strlen(hostname),
                 .src_sap        = &source,
                 .src_len        = sizeof(source),
+                .noresvport     = noresvport,
         };
 
         dprintk("lockd: %s(host='%s', vers=%u, proto=%s)\n", __func__,
@@ -417,6 +423,8 @@ nlm_bind_host(struct nlm_host *host)
                  */
                 if (!host->h_server)
                         args.flags |= RPC_CLNT_CREATE_HARDRTRY;
+                if (host->h_noresvport)
+                        args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
 
                 clnt = rpc_create(&args);
                 if (!IS_ERR(clnt))