2.5-18.1

1 files changed, 278 insertions, 0 deletions

diff --git a/inet/inet6_opt.c b/inet/inet6_opt.c
new file mode 100644
index 0000000000..17d3fee213
--- /dev/null
+++ b/inet/inet6_opt.c
@@ -0,0 +1,278 @@
+/* Copyright (C) 2006, 2007 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2006.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <string.h>
+#include <netinet/in.h>
+#include <netinet/ip6.h>
+
+
+/* RFC 3542, 10.1
+
+   This function returns the number of bytes needed for the empty
+   extension header i.e., without any options.  If EXTBUF is not NULL it
+   also initializes the extension header to have the correct length
+   field.  In that case if the EXTLEN value is not a positive (i.e.,
+   non-zero) multiple of 8 the function fails and returns -1.  */
+int
+inet6_opt_init (void *extbuf, socklen_t extlen)
+{
+  if (extbuf != NULL)
+    {
+      if (extlen <= 0 || (extlen % 8) != 0)
+	return -1;
+
+      /* Fill in the length in units of 8 octets.  */
+      struct ip6_hbh *extp = (struct ip6_hbh *) extbuf;
+      extp->ip6h_len = extlen / 8;
+    }
+
+  return sizeof (struct ip6_hbh);
+}
+
+
+static void
+add_padding (uint8_t *extbuf, int offset, int npad)
+{
+  if (npad == 1)
+    extbuf[offset] = IP6OPT_PAD1;
+  else if (npad > 0)
+    {
+      struct ip6_opt *pad_opt = (struct ip6_opt *) (extbuf + offset);
+
+      pad_opt->ip6o_type = IP6OPT_PADN;
+      pad_opt->ip6o_len = npad - sizeof (struct ip6_opt);
+      /* Clear the memory used by the padding.  */
+      memset (pad_opt + 1, '\0', pad_opt->ip6o_len);
+    }
+}
+
+
+
+/* RFC 3542, 10.2
+
+   This function returns the updated total length taking into account
+   adding an option with length 'len' and alignment 'align'.  If
+   EXTBUF is not NULL then, in addition to returning the length, the
+   function inserts any needed pad option, initializes the option
+   (setting the type and length fields) and returns a pointer to the
+   location for the option content in databufp.  If the option does
+   not fit in the extension header buffer the function returns -1.  */
+int
+inet6_opt_append (void *extbuf, socklen_t extlen, int offset, uint8_t type,
+		  socklen_t len, uint8_t align, void **databufp)
+{
+  /* Check minimum offset.  */
+  if (offset < sizeof (struct ip6_hbh))
+    return -1;
+
+  /* One cannot add padding options.  */
+  if (type == IP6OPT_PAD1 || type == IP6OPT_PADN)
+    return -1;
+
+  /* The option length must fit in one octet.  */
+  if (len > 255)
+    return -1;
+
+  /* The alignment can only by 1, 2, 4, or 8 and must not exceed the
+     option length.  */
+  if (align == 0 || align > 8 || (align & (align - 1)) != 0 || align > len)
+    return -1;
+
+  /* Determine the needed padding for alignment.  Following the
+     current content of the buffer we have the is the IPv6 option type
+     and length, followed immediately by the data.  The data has the
+     alignment constraints.  Therefore padding must be inserted in the
+     form of padding options before the new option. */
+  int data_offset = offset + sizeof (struct ip6_opt);
+  int npad = (align - data_offset % align) & (align - 1);
+
+  if (extbuf != NULL)
+    {
+      /* Now we can check whether the buffer is large enough.  */
+      if (data_offset + npad + len > extlen)
+	return -1;
+
+      add_padding (extbuf, offset, npad);
+
+      offset += npad;
+
+      /* Now prepare the option itself.  */
+      struct ip6_opt *opt = (struct ip6_opt *) ((uint8_t *) extbuf + offset);
+
+      opt->ip6o_type = type;
+      opt->ip6o_len = len;
+
+      *databufp = opt + 1;
+    }
+  else
+    offset += npad;
+
+  return offset + sizeof (struct ip6_opt) + len;
+}
+
+
+/* RFC 3542, 10.3
+
+   This function returns the updated total length taking into account
+   the final padding of the extension header to make it a multiple of
+   8 bytes.  If EXTBUF is not NULL the function also initializes the
+   option by inserting a Pad1 or PadN option of the proper length.  */
+int
+inet6_opt_finish (void *extbuf, socklen_t extlen, int offset)
+{
+  /* Check minimum offset.  */
+  if (offset < sizeof (struct ip6_hbh))
+    return -1;
+
+  /* Required padding at the end.  */
+  int npad = (8 - (offset & 7)) & 7;
+
+  if (extbuf != NULL)
+    {
+      /* Make sure the buffer is large enough.  */
+      if (offset + npad > extlen)
+	return -1;
+
+      add_padding (extbuf, offset, npad);
+    }
+
+  return offset + npad;
+}
+
+
+/* RFC 3542, 10.4
+
+   This function inserts data items of various sizes in the data
+   portion of the option.  VAL should point to the data to be
+   inserted.  OFFSET specifies where in the data portion of the option
+   the value should be inserted; the first byte after the option type
+   and length is accessed by specifying an offset of zero.  */
+int
+inet6_opt_set_val (void *databuf, int offset, void *val, socklen_t vallen)
+{
+  memcpy ((uint8_t *) databuf + offset, val, vallen);
+
+  return offset + vallen;
+}
+
+
+/* RFC 3542, 10.5
+
+   This function parses received option extension headers returning
+   the next option.  EXTBUF and EXTLEN specifies the extension header.
+   OFFSET should either be zero (for the first option) or the length
+   returned by a previous call to 'inet6_opt_next' or
+   'inet6_opt_find'.  It specifies the position where to continue
+   scanning the extension buffer.  */
+int
+inet6_opt_next (void *extbuf, socklen_t extlen, int offset, uint8_t *typep,
+		socklen_t *lenp, void **databufp)
+{
+  if (offset == 0)
+    offset = sizeof (struct ip6_hbh);
+  else if (offset < sizeof (struct ip6_hbh))
+    return -1;
+
+  while (offset < extlen)
+    {
+      struct ip6_opt *opt = (struct ip6_opt *) ((uint8_t *) extbuf + offset);
+
+      if (opt->ip6o_type == IP6OPT_PAD1)
+	/* Single byte padding.  */
+	++offset;
+      else if (opt->ip6o_type == IP6OPT_PADN)
+	offset += sizeof (struct ip6_opt) + opt->ip6o_len;
+      else
+	{
+	  /* Check whether the option is valid.  */
+	  offset += sizeof (struct ip6_opt) + opt->ip6o_len;
+	  if (offset > extlen)
+	    return -1;
+
+	  *typep = opt->ip6o_type;
+	  *lenp = opt->ip6o_len;
+	  *databufp = opt + 1;
+	  return offset;
+	}
+    }
+
+  return -1;
+}
+
+
+/* RFC 3542, 10.6
+
+   This function is similar to the previously described
+   'inet6_opt_next' function, except this function lets the caller
+   specify the option type to be searched for, instead of always
+   returning the next option in the extension header.  */
+int
+inet6_opt_find (void *extbuf, socklen_t extlen, int offset, uint8_t type,
+		socklen_t *lenp, void **databufp)
+{
+  if (offset == 0)
+    offset = sizeof (struct ip6_hbh);
+  else if (offset < sizeof (struct ip6_hbh))
+    return -1;
+
+  while (offset < extlen)
+    {
+      struct ip6_opt *opt = (struct ip6_opt *) ((uint8_t *) extbuf + offset);
+
+      if (opt->ip6o_type == IP6OPT_PAD1)
+	{
+	  /* Single byte padding.  */
+	  ++offset;
+	  if (type == IP6OPT_PAD1)
+	    {
+	      *lenp = 0;
+	      *databufp = (uint8_t *) extbuf + offset;
+	      return offset;
+	    }
+	}
+      else if (opt->ip6o_type != type)
+	offset += sizeof (struct ip6_opt) + opt->ip6o_len;
+      else
+	{
+	  /* Check whether the option is valid.  */
+	  offset += sizeof (struct ip6_opt) + opt->ip6o_len;
+	  if (offset > extlen)
+	    return -1;
+
+	  *lenp = opt->ip6o_len;
+	  *databufp = opt + 1;
+	  return offset;
+	}
+    }
+
+  return -1;
+}
+
+
+/* RFC 3542, 10.7
+
+   This function extracts data items of various sizes in the data
+   portion of the option.  */
+int
+inet6_opt_get_val (void *databuf, int offset, void *val, socklen_t vallen)
+{
+  memcpy (val, (uint8_t *) databuf + offset, vallen);
+
+  return offset + vallen;
+}