2.5-18.1

1 files changed, 192 insertions, 0 deletions

diff --git a/inet/inet6_rth.c b/inet/inet6_rth.c
new file mode 100644
index 0000000..15f8240
--- /dev/null
+++ b/inet/inet6_rth.c
@@ -0,0 +1,192 @@
+/* Copyright (C) 2006 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, 7.1
+
+   This function returns the number of bytes required to hold a
+   Routing header of the specified type containing the specified
+   number of segments (addresses).  For an IPv6 Type 0 Routing header,
+   the number of segments must be between 0 and 127, inclusive.  */
+socklen_t
+inet6_rth_space (int type, int segments)
+{
+  switch (type)
+    {
+    case IPV6_RTHDR_TYPE_0:
+      if (segments < 0 || segments > 127)
+	return 0;
+
+      return sizeof (struct ip6_rthdr0) + segments * sizeof (struct in6_addr);
+    }
+
+  return 0;
+}
+
+
+/* RFC 3542, 7.2
+
+   This function initializes the buffer pointed to by BP to contain a
+   Routing header of the specified type and sets ip6r_len based on the
+   segments parameter.  */
+void *
+inet6_rth_init (void *bp, socklen_t bp_len, int type, int segments)
+{
+  struct ip6_rthdr *rthdr = (struct ip6_rthdr *) bp;
+
+  switch (type)
+    {
+    case IPV6_RTHDR_TYPE_0:
+      /* Make sure the parameters are valid and the buffer is large enough.  */
+      if (segments < 0 || segments > 127)
+	break;
+
+      socklen_t len = (sizeof (struct ip6_rthdr0)
+		       + segments * sizeof (struct in6_addr));
+      if (len > bp_len)
+	break;
+
+      /* Some implementations seem to initialize the whole memory area.  */
+      memset (bp, '\0', len);
+
+      /* Length in units of 8 octets.  */
+      rthdr->ip6r_len = segments * sizeof (struct in6_addr) / 8;
+      rthdr->ip6r_type = IPV6_RTHDR_TYPE_0;
+      return bp;
+    }
+
+  return NULL;
+}
+
+
+/* RFC 3542, 7.3
+
+   This function adds the IPv6 address pointed to by addr to the end of
+   the Routing header being constructed.  */
+int
+inet6_rth_add (void *bp, const struct in6_addr *addr)
+{
+  struct ip6_rthdr *rthdr = (struct ip6_rthdr *) bp;
+
+  switch (rthdr->ip6r_type)
+    {
+      struct ip6_rthdr0 *rthdr0;
+    case IPV6_RTHDR_TYPE_0:
+      rthdr0 = (struct ip6_rthdr0 *) rthdr;
+
+      memcpy (&rthdr0->ip6r0_addr[rthdr0->ip6r0_segleft++],
+	      addr, sizeof (struct in6_addr));
+
+      return 0;
+    }
+
+  return -1;
+}
+
+
+/* RFC 3542, 7.4
+
+   This function takes a Routing header extension header (pointed to by
+   the first argument) and writes a new Routing header that sends
+   datagrams along the reverse of that route.  The function reverses the
+   order of the addresses and sets the segleft member in the new Routing
+   header to the number of segments.  */
+int
+inet6_rth_reverse (const void *in, void *out)
+{
+  struct ip6_rthdr *in_rthdr = (struct ip6_rthdr *) in;
+
+  switch (in_rthdr->ip6r_type)
+    {
+      struct ip6_rthdr0 *in_rthdr0;
+      struct ip6_rthdr0 *out_rthdr0;
+    case IPV6_RTHDR_TYPE_0:
+      in_rthdr0 = (struct ip6_rthdr0 *) in;
+      out_rthdr0 = (struct ip6_rthdr0 *) out;
+
+      /* Copy header, not the addresses.  The memory regions can overlap.  */
+      memmove (out_rthdr0, in_rthdr0, sizeof (struct ip6_rthdr0));
+
+      int total = in_rthdr0->ip6r0_segleft * 8 / sizeof (struct in6_addr);
+      for (int i = 0; i < total / 2; ++i)
+	{
+	  /* Remember, IN_RTHDR0 and OUT_RTHDR0 might overlap.  */
+	  struct in6_addr temp = in_rthdr0->ip6r0_addr[i];
+	  out_rthdr0->ip6r0_addr[i] = in_rthdr0->ip6r0_addr[total - 1 - i];
+	  out_rthdr0->ip6r0_addr[total - 1 - i] = temp;
+	}
+      if (total % 2 != 0 && in != out)
+	out_rthdr0->ip6r0_addr[total / 2] = in_rthdr0->ip6r0_addr[total / 2];
+
+      return 0;
+    }
+
+  return -1;
+}
+
+
+/* RFC 3542, 7.5
+
+   This function returns the number of segments (addresses) contained in
+   the Routing header described by BP.  */
+int
+inet6_rth_segments (const void *bp)
+{
+  struct ip6_rthdr *rthdr = (struct ip6_rthdr *) bp;
+
+  switch (rthdr->ip6r_type)
+    {
+    case IPV6_RTHDR_TYPE_0:
+
+      return rthdr->ip6r_len * 8 / sizeof (struct in6_addr);
+    }
+
+  return -1;
+}
+
+
+/* RFC 3542, 7.6
+
+   This function returns a pointer to the IPv6 address specified by
+   index (which must have a value between 0 and one less than the
+   value returned by 'inet6_rth_segments') in the Routing header
+   described by BP.  */
+struct in6_addr *
+inet6_rth_getaddr (const void *bp, int index)
+{
+  struct ip6_rthdr *rthdr = (struct ip6_rthdr *) bp;
+
+  switch (rthdr->ip6r_type)
+    {
+       struct ip6_rthdr0 *rthdr0;
+    case IPV6_RTHDR_TYPE_0:
+      rthdr0 = (struct ip6_rthdr0 *) rthdr;
+
+      if (index >= rthdr0->ip6r0_len * 8 / sizeof (struct in6_addr))
+	break;
+
+      return &rthdr0->ip6r0_addr[index];
+    }
+
+  return NULL;
+}