From 3035b12250bf7b9eb0b67d41d5001ccd18683e52 Mon Sep 17 00:00:00 2001
From: Michael Vrable <mvrable@cs.ucsd.edu>
Date: Wed, 13 Jan 2010 16:12:30 -0800
Subject: [PATCH] Eliminate last static buffer in async_rpc_send_reply.

---
 nfs3/rpc.c | 73 +++++++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 69 insertions(+), 4 deletions(-)

diff --git a/nfs3/rpc.c b/nfs3/rpc.c
index 67a9c7c..6717512 100644
--- a/nfs3/rpc.c
+++ b/nfs3/rpc.c
@@ -121,6 +121,68 @@ struct rpc_fail_reply {
     uint32_t accept_stat;
 };
 
+/* Routines for XDR-encoding to a growable string. */
+static bool_t xdr_string_putlong(XDR *xdrs, const long *lp)
+{
+    GString *str = (GString *)xdrs->x_private;
+    uint32_t data = htonl(*lp);
+    g_string_set_size(str, str->len + 4);
+    memcpy(str->str + str->len - 4, &data, 4);
+    return TRUE;
+}
+
+static bool_t xdr_string_putbytes(XDR *xdrs, const char *addr, u_int len)
+{
+    GString *str = (GString *)xdrs->x_private;
+    g_string_set_size(str, str->len + len);
+    memcpy(str->str + str->len - len, addr, len);
+    return TRUE;
+}
+
+static u_int xdr_string_getpos(const XDR *xdrs)
+{
+    GString *str = (GString *)xdrs->x_private;
+    return str->len;
+}
+
+static bool_t xdr_string_putint32(XDR *xdrs, const int32_t *ip)
+{
+    GString *str = (GString *)xdrs->x_private;
+    uint32_t data = htonl(*ip);
+    g_string_set_size(str, str->len + 4);
+    memcpy(str->str + str->len - 4, &data, 4);
+    return TRUE;
+}
+
+static int32_t *xdr_string_inline(XDR *xdrs, u_int len)
+{
+    GString *str = (GString *)xdrs->x_private;
+    g_string_set_size(str, str->len + len);
+    return (int32_t *)(str->str + str->len - len);
+}
+
+static void xdr_string_destroy(XDR *xdrs)
+{
+}
+
+static struct xdr_ops xdr_string_ops = {
+    .x_putlong = xdr_string_putlong,
+    .x_putbytes = xdr_string_putbytes,
+    .x_getpostn = xdr_string_getpos,
+    .x_putint32 = xdr_string_putint32,
+    .x_inline = xdr_string_inline,
+    .x_destroy = xdr_string_destroy,
+};
+
+static void xdr_string_create(XDR *xdrs, GString *string, enum xdr_op op)
+{
+    xdrs->x_op = op;
+    xdrs->x_ops = &xdr_string_ops;
+    xdrs->x_private = (char *)string;
+    xdrs->x_base = NULL;
+    xdrs->x_handy = 0;
+}
+
 static void
 async_rpc_send_failure(RPCRequest *req, enum accept_stat stat)
 {
@@ -158,11 +220,12 @@ async_rpc_send_failure(RPCRequest *req, enum accept_stat stat)
 void
 async_rpc_send_reply(RPCRequest *req, void *result)
 {
-    static char reply_buf[MAX_RPC_MSGSIZE];
+    GString *str = g_string_new("");
     XDR xdr_out;
-    xdrmem_create(&xdr_out, reply_buf, MAX_RPC_MSGSIZE, XDR_ENCODE);
+    xdr_string_create(&xdr_out, str, XDR_ENCODE);
     if (!req->xdr_result(&xdr_out, result)) {
         async_rpc_send_failure(req, SYSTEM_ERR);
+        g_string_free(str, TRUE);
         return;
     }
 
@@ -174,15 +237,17 @@ async_rpc_send_reply(RPCRequest *req, void *result)
     header.verf_len = 0;
     header.accept_stat = 0;
 
-    gsize msg_size = xdr_out.x_ops->x_getpostn(&xdr_out);
+    gsize msg_size = str->len;
     printf("Have an RPC reply of size %zd bytes\n", msg_size);
     uint32_t fragment = htonl((msg_size + sizeof(header)) | 0x80000000);
     async_rpc_write(req->connection, (const char *)&fragment, sizeof(fragment));
     async_rpc_write(req->connection, (const char *)&header, sizeof(header));
-    async_rpc_write(req->connection, reply_buf, msg_size);
+    async_rpc_write(req->connection, str->str, str->len);
     g_io_channel_flush(req->connection->channel, NULL);
 
     /* Clean up. */
+    g_string_free(str, TRUE);
+
     if (req->args != NULL) {
         char buf[4];
         XDR xdr;
-- 
2.20.1