[libvirt] [PATCHv2 2/3] util: new virSocketAddrIsPrivate function

[Laine Stump]

This new function returns true if the given address is in the range of
any "private" or "local" networks as defined in RFC1918 (IPv4) or
RFC4193 (IPv6), otherwise they return false.

These ranges are:

   192.168.0.0/16
   172.16.0.0/16
   10.0.0.0/24
   FC00::/7
---
 src/libvirt_private.syms |  1 +
 src/util/virsocketaddr.c | 32 +++++++++++++++++++++++++++++++-
 src/util/virsocketaddr.h |  3 ++-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index b692fcb..876be4f 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1781,6 +1781,7 @@ virSocketAddrFormatFull;
 virSocketAddrGetPort;
 virSocketAddrGetRange;
 virSocketAddrIsNetmask;
+virSocketAddrIsPrivate;
 virSocketAddrMask;
 virSocketAddrMaskByPrefix;
 virSocketAddrParse;
diff --git a/src/util/virsocketaddr.c b/src/util/virsocketaddr.c
index b6cc16f..2d39458 100644
--- a/src/util/virsocketaddr.c
+++ b/src/util/virsocketaddr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2011 Red Hat, Inc.
+ * Copyright (C) 2009-2012 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -194,6 +194,36 @@ virSocketAddrEqual(const virSocketAddrPtr s1, const virSocketAddrPtr s2)
 }
 
 /*
+ * virSocketAddrIsPrivate:
+ * @s: the location of the IP address
+ *
+ * Return true if this address is in its family's defined
+ * "private/local" address space. For IPv4, private addresses are in
+ * the range of 192.168.0.0/16, 172.16.0.0/16, or 10.0.0.0/8.  For
+ * IPv6, local addresses are in the range of FC00::/7.
+ *
+ * See RFC1918 and RFC4193 for details.
+ */
+bool
+virSocketAddrIsPrivate(const virSocketAddrPtr addr)
+{
+    unsigned long val;
+
+    switch (addr->data.stor.ss_family) {
+    case AF_INET:
+       val = ntohl(addr->data.inet4.sin_addr.s_addr);
+
+       return ((val & 0xFFFF0000) == ((192L << 24) + (168 << 16)) ||
+               (val & 0xFFFF0000) == ((172L << 24) + (16  << 16)) ||
+               (val & 0xFF000000) == ((10L  << 24)));
+
+    case AF_INET6:
+        return (addr->data.inet6.sin6_addr.s6_addr[0] & 0xFC) == 0xFC;
+    }
+    return false;
+}
+
+/*
  * virSocketAddrFormat:
  * @addr: an initialized virSocketAddrPtr
  *
diff --git a/src/util/virsocketaddr.h b/src/util/virsocketaddr.h
index 51ddd2d..66d4265 100644
--- a/src/util/virsocketaddr.h
+++ b/src/util/virsocketaddr.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2011 Red Hat, Inc.
+ * Copyright (C) 2009-2012 Red Hat, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
@@ -104,5 +104,6 @@ int virSocketAddrPrefixToNetmask(unsigned int prefix,
                                  int family);
 bool virSocketAddrEqual(const virSocketAddrPtr s1,
                         const virSocketAddrPtr s2);
+bool virSocketAddrIsPrivate(const virSocketAddrPtr addr);
 
 #endif /* __VIR_SOCKETADDR_H__ */
-- 
1.7.11.7