Initial Implementation of TFTP protocol and new protocol structs.

net/netbuff.c

@@ -0,0 +1,72 @@
+/*
+ *  GRUB  --  GRand Unified Bootloader
+ *  Copyright (C) 2010 Free Software Foundation, Inc.
+ *
+ *  GRUB is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  GRUB is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/err.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+#include <grub/net/netbuff.h>
+
+
+grub_err_t grub_netbuff_put (struct grub_net_buff *net_buff ,grub_size_t len)
+{
+  net_buff->tail += len;
+  if (net_buff->tail > net_buff->end)
+    return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of the packet range.");
+  return GRUB_ERR_NONE; 
+}
+
+grub_err_t grub_netbuff_unput (struct grub_net_buff *net_buff ,grub_size_t len)
+{
+  net_buff->tail -= len;
+  if (net_buff->tail < net_buff->head)
+    return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of the packet range.");
+  return GRUB_ERR_NONE; 
+}
+
+grub_err_t grub_netbuff_push (struct grub_net_buff *net_buff ,grub_size_t len)
+{
+  net_buff->data -= len;
+  if (net_buff->data < net_buff->head)
+    return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of the packet range.");
+  return GRUB_ERR_NONE; 
+}
+
+grub_err_t grub_netbuff_pull (struct grub_net_buff *net_buff ,grub_size_t len)
+{
+  net_buff->data += len;
+  if (net_buff->data > net_buff->end)
+    return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of the packet range.");
+  return GRUB_ERR_NONE; 
+}
+
+grub_err_t grub_netbuff_reserve (struct grub_net_buff *net_buff ,grub_size_t len)
+{
+  net_buff->data += len;
+  net_buff->tail += len;
+  if ((net_buff->tail > net_buff->end) || (net_buff->data > net_buff->end))
+    return grub_error (GRUB_ERR_OUT_OF_RANGE, "out of the packet range.");
+  return GRUB_ERR_NONE; 
+}
+
+struct grub_net_buff * grub_netbuff_alloc ( grub_size_t len )
+{
+  if (len < NETBUFFMINLEN) 
+    len = NETBUFFMINLEN;
+  len = ALIGN_UP (len,NETBUFF_ALIGN);
+  return (struct grub_net_buff *) grub_memalign (len,NETBUFF_ALIGN); 
+}