1 files changed, 133 insertions, 0 deletions
diff --git a/grub-core/net/netbuff.c b/grub-core/net/netbuff.c
new file mode 100644
index 0000000..dbeeefe
--- /dev/null
+++ b/grub-core/net/netbuff.c
@@ -0,0 +1,133 @@
+/*
+ *  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 *nb, grub_size_t len)
+{
+  nb->tail += len;
+  if (nb->tail > nb->end)
+    return grub_error (GRUB_ERR_BUG, "put out of the packet range.");
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_netbuff_unput (struct grub_net_buff *nb, grub_size_t len)
+{
+  nb->tail -= len;
+  if (nb->tail < nb->head)
+    return grub_error (GRUB_ERR_BUG,
+		       "unput out of the packet range.");
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_netbuff_push (struct grub_net_buff *nb, grub_size_t len)
+{
+  nb->data -= len;
+  if (nb->data < nb->head)
+    return grub_error (GRUB_ERR_BUG,
+		       "push out of the packet range.");
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_netbuff_pull (struct grub_net_buff *nb, grub_size_t len)
+{
+  nb->data += len;
+  if (nb->data > nb->end)
+    return grub_error (GRUB_ERR_BUG,
+		       "pull out of the packet range.");
+  return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_netbuff_reserve (struct grub_net_buff *nb, grub_size_t len)
+{
+  nb->data += len;
+  nb->tail += len;
+  if ((nb->tail > nb->end) || (nb->data > nb->end))
+    return grub_error (GRUB_ERR_BUG,
+		       "reserve out of the packet range.");
+  return GRUB_ERR_NONE;
+}
+
+struct grub_net_buff *
+grub_netbuff_alloc (grub_size_t len)
+{
+  struct grub_net_buff *nb;
+  void *data;
+
+  COMPILE_TIME_ASSERT (NETBUFF_ALIGN % sizeof (grub_properly_aligned_t) == 0);
+
+  if (len < NETBUFFMINLEN)
+    len = NETBUFFMINLEN;
+
+  len = ALIGN_UP (len, NETBUFF_ALIGN);
+#ifdef GRUB_MACHINE_EMU
+  data = grub_malloc (len + sizeof (*nb));
+#else
+  data = grub_memalign (NETBUFF_ALIGN, len + sizeof (*nb));
+#endif
+  if (!data)
+    return NULL;
+  nb = (struct grub_net_buff *) ((grub_properly_aligned_t *) data
+				 + len / sizeof (grub_properly_aligned_t));
+  nb->head = nb->data = nb->tail = data;
+  nb->end = (grub_uint8_t *) nb;
+  return nb;
+}
+
+struct grub_net_buff *
+grub_netbuff_make_pkt (grub_size_t len)
+{
+  struct grub_net_buff *nb;
+  grub_err_t err;
+  nb = grub_netbuff_alloc (len + 512);
+  if (!nb)
+    return NULL;
+  err = grub_netbuff_reserve (nb, len + 512);
+  if (err)
+    goto fail;
+  err = grub_netbuff_push (nb, len);
+  if (err)
+    goto fail;
+  return nb;
+ fail:
+  grub_netbuff_free (nb);
+  return NULL;
+}
+
+void
+grub_netbuff_free (struct grub_net_buff *nb)
+{
+  if (!nb)
+    return;
+  grub_free (nb->head);
+}
+
+grub_err_t
+grub_netbuff_clear (struct grub_net_buff *nb)
+{
+  nb->data = nb->tail = nb->head;
+  return GRUB_ERR_NONE;
+}