lockd: document use of mon_id argument in SM_MON requests

[pandora-kernel.git] / fs / lockd / mon.c

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 908b23f..3935d7b 100644 (file)
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -18,6 +18,8 @@
 
 #define NLMDBG_FACILITY                NLMDBG_MONITOR
 
+#define XDR_ADDRBUF_LEN                (20)
+
 static struct rpc_clnt *       nsm_create(void);
 
 static struct rpc_program      nsm_program;
@@ -149,6 +151,70 @@ nsm_create(void)
  * XDR functions for NSM.
  */
 
+static __be32 *xdr_encode_nsm_string(__be32 *p, char *string)
+{
+       size_t len = strlen(string);
+
+       if (len > SM_MAXSTRLEN)
+               len = SM_MAXSTRLEN;
+       return xdr_encode_opaque(p, string, len);
+}
+
+/*
+ * "mon_name" specifies the host to be monitored.
+ *
+ * Linux uses a text version of the IP address of the remote
+ * host as the host identifier (the "mon_name" argument).
+ *
+ * Linux statd always looks up the canonical hostname first for
+ * whatever remote hostname it receives, so this works alright.
+ */
+static __be32 *xdr_encode_mon_name(__be32 *p, struct nsm_args *argp)
+{
+       char    buffer[XDR_ADDRBUF_LEN + 1];
+       char    *name = argp->mon_name;
+
+       if (!nsm_use_hostnames) {
+               snprintf(buffer, XDR_ADDRBUF_LEN,
+                        NIPQUAD_FMT, NIPQUAD(argp->addr));
+               name = buffer;
+       }
+
+       return xdr_encode_nsm_string(p, name);
+}
+
+/*
+ * The "my_id" argument specifies the hostname and RPC procedure
+ * to be called when the status manager receives notification
+ * (via the SM_NOTIFY call) that the state of host "mon_name"
+ * has changed.
+ */
+static __be32 *xdr_encode_my_id(__be32 *p, struct nsm_args *argp)
+{
+       p = xdr_encode_nsm_string(p, utsname()->nodename);
+       if (!p)
+               return ERR_PTR(-EIO);
+
+       *p++ = htonl(argp->prog);
+       *p++ = htonl(argp->vers);
+       *p++ = htonl(argp->proc);
+
+       return p;
+}
+
+/*
+ * The "mon_id" argument specifies the non-private arguments
+ * of an SM_MON or SM_UNMON call.
+ */
+static __be32 *xdr_encode_mon_id(__be32 *p, struct nsm_args *argp)
+{
+       p = xdr_encode_mon_name(p, argp);
+       if (!p)
+               return ERR_PTR(-EIO);
+
+       return xdr_encode_my_id(p, argp);
+}
+
 static __be32 *
 xdr_encode_common(struct rpc_rqst *rqstp, __be32 *p, struct nsm_args *argp)
 {