[libvirt] [PATCH 1/3] network: validate DHCP ranges are completely within defined network

Laine Stump laine at laine.org
Tue May 26 19:48:02 UTC 2015


virSocketAddrGetRange() has been updated to take the network address
and prefix, and now checks that both the start and end of the range
are within that network, thus validating that the entire range of
addresses is in the network. For IPv4, it also checks that ranges to
not start with the "network address" of the subnet, nor end with the
broadcast address of the subnet (this check doesn't apply to IPv6,
since IPv6 doesn't have a broadcast or network address)

Negative tests have been added to the network update and socket tests
to verify that bad ranges properly generate an error.

This resolves: https://bugzilla.redhat.com/show_bug.cgi?id=985653
---
 src/conf/network_conf.c                            | 14 ++---
 src/network/bridge_driver.c                        |  4 +-
 src/util/virsocketaddr.c                           | 61 ++++++++++++++++++----
 src/util/virsocketaddr.h                           |  6 ++-
 tests/networkxml2xmlupdatein/dhcp-range-10.xml     |  1 +
 tests/networkxml2xmlupdatein/dhcp-range.xml        |  2 +-
 .../dhcp6host-routed-network-another-range.xml     |  2 +-
 .../dhcp6host-routed-network-range.xml             |  2 +-
 tests/networkxml2xmlupdatetest.c                   |  5 ++
 tests/sockettest.c                                 | 55 ++++++++++++-------
 10 files changed, 112 insertions(+), 40 deletions(-)
 create mode 100644 tests/networkxml2xmlupdatein/dhcp-range-10.xml

diff --git a/src/conf/network_conf.c b/src/conf/network_conf.c
index bc63a3d..f9f3d3d 100644
--- a/src/conf/network_conf.c
+++ b/src/conf/network_conf.c
@@ -832,8 +832,9 @@ int virNetworkIpDefNetmask(const virNetworkIpDef *def,
 
 static int
 virSocketAddrRangeParseXML(const char *networkName,
-                               xmlNodePtr node,
-                               virSocketAddrRangePtr range)
+                           virNetworkIpDefPtr ipdef,
+                           xmlNodePtr node,
+                           virSocketAddrRangePtr range)
 {
 
 
@@ -859,7 +860,8 @@ virSocketAddrRangeParseXML(const char *networkName,
         goto cleanup;
 
     /* do a sanity check of the range */
-    if (virSocketAddrGetRange(&range->start, &range->end) < 0) {
+    if (virSocketAddrGetRange(&range->start, &range->end, &ipdef->address,
+                              virNetworkIpDefPrefix(ipdef)) < 0) {
         virReportError(VIR_ERR_XML_ERROR,
                        _("Invalid dhcp range '%s' to '%s' in network '%s'"),
                        start, end, networkName);
@@ -1009,8 +1011,8 @@ virNetworkDHCPDefParseXML(const char *networkName,
 
             if (VIR_REALLOC_N(def->ranges, def->nranges + 1) < 0)
                 return -1;
-            if (virSocketAddrRangeParseXML(networkName, cur,
-                                               &def->ranges[def->nranges]) < 0) {
+            if (virSocketAddrRangeParseXML(networkName, def, cur,
+                                           &def->ranges[def->nranges]) < 0) {
                 return -1;
             }
             def->nranges++;
@@ -3608,7 +3610,7 @@ virNetworkDefUpdateIPDHCPRange(virNetworkDefPtr def,
         goto cleanup;
     }
 
-    if (virSocketAddrRangeParseXML(def->name, ctxt->node, &range) < 0)
+    if (virSocketAddrRangeParseXML(def->name, ipdef, ctxt->node, &range) < 0)
         goto cleanup;
 
     /* check if an entry with same name/address/ip already exists */
diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
index 4b53475..e08a316 100644
--- a/src/network/bridge_driver.c
+++ b/src/network/bridge_driver.c
@@ -1193,7 +1193,9 @@ networkDnsmasqConfContents(virNetworkObjPtr network,
             VIR_FREE(saddr);
             VIR_FREE(eaddr);
             nbleases += virSocketAddrGetRange(&ipdef->ranges[r].start,
-                                              &ipdef->ranges[r].end);
+                                              &ipdef->ranges[r].end,
+                                              &ipdef->address,
+                                              virNetworkIpDefPrefix(ipdef));
         }
 
         /*
diff --git a/src/util/virsocketaddr.c b/src/util/virsocketaddr.c
index 67ed330..0edf345 100644
--- a/src/util/virsocketaddr.c
+++ b/src/util/virsocketaddr.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2014 Red Hat, Inc.
+ * Copyright (C) 2009-2015 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
@@ -605,31 +605,69 @@ int virSocketAddrCheckNetmask(virSocketAddrPtr addr1, virSocketAddrPtr addr2,
  * virSocketGetRange:
  * @start: start of an IP range
  * @end: end of an IP range
+ * @network: IP address of network that should completely contain this range
+ * @prefix: prefix of the network
  *
- * Check the order of the 2 addresses and compute the range, this
- * will return 1 for identical addresses. Errors can come from incompatible
- * addresses type, excessive range (>= 2^^16) where the two addresses are
- * unrelated or inverted start and end.
+ * Check the order of the 2 addresses and compute the range, this will
+ * return 1 for identical addresses. Errors can come from incompatible
+ * addresses type, excessive range (>= 2^^16) where the two addresses
+ * are unrelated, inverted start and end, or a range that is not
+ * within network/prefix.
  *
  * Returns the size of the range or -1 in case of failure
  */
-int virSocketAddrGetRange(virSocketAddrPtr start, virSocketAddrPtr end)
+int
+virSocketAddrGetRange(virSocketAddrPtr start, virSocketAddrPtr end,
+                      virSocketAddrPtr network, int prefix)
 {
     int ret = 0;
     size_t i;
+    virSocketAddr netmask;
+
+    if (start == NULL || end == NULL || network == NULL)
+        return -1;
+
+    if (VIR_SOCKET_ADDR_FAMILY(start) != VIR_SOCKET_ADDR_FAMILY(end) ||
+        VIR_SOCKET_ADDR_FAMILY(start) != VIR_SOCKET_ADDR_FAMILY(network))
+        return -1;
 
-    if ((start == NULL) || (end == NULL))
+    if (prefix < 0 ||
+        virSocketAddrPrefixToNetmask(prefix, &netmask, VIR_SOCKET_ADDR_FAMILY(network)) < 0)
         return -1;
-    if (start->data.stor.ss_family != end->data.stor.ss_family)
+
+    /* both start and end of range need to be in the same network as
+     * "network"
+     */
+    if (virSocketAddrCheckNetmask(start, network, &netmask) <= 0 ||
+        virSocketAddrCheckNetmask(start, network, &netmask) <= 0)
         return -1;
 
-    if (start->data.stor.ss_family == AF_INET) {
+    if (VIR_SOCKET_ADDR_IS_FAMILY(start, AF_INET)) {
         virSocketAddrIPv4 t1, t2;
+        virSocketAddr netaddr, broadcast;
+
+        if (virSocketAddrBroadcast(network, &netmask, &broadcast) < 0 ||
+            virSocketAddrMask(network, &netmask, &netaddr) < 0)
+           return -1;
+
+        /* Don't allow the start of the range to be the network
+         * address (usually "...0") or the end of the range to be the
+         * broadcast address (usually "...255"). (the opposite also
+         * isn't allowed, but checking for that is implicit in all the
+         * other combined checks) (IPv6 doesn't have broadcast and
+         * network addresses, so this check is only done for IPv4)
+         */
+        if (virSocketAddrEqual(start, &netaddr) ||
+            virSocketAddrEqual(end, &broadcast))
+            return -1;
 
         if ((virSocketAddrGetIPv4Addr(start, &t1) < 0) ||
             (virSocketAddrGetIPv4Addr(end, &t2) < 0))
             return -1;
 
+        /* legacy check that everything except the last two bytes are
+         * the same
+         */
         for (i = 0; i < 2; i++) {
             if (t1[i] != t2[i])
                 return -1;
@@ -638,13 +676,16 @@ int virSocketAddrGetRange(virSocketAddrPtr start, virSocketAddrPtr end)
         if (ret < 0)
             return -1;
         ret++;
-    } else if (start->data.stor.ss_family == AF_INET6) {
+    } else if (VIR_SOCKET_ADDR_IS_FAMILY(start, AF_INET6)) {
         virSocketAddrIPv6 t1, t2;
 
         if ((virSocketAddrGetIPv6Addr(start, &t1) < 0) ||
             (virSocketAddrGetIPv6Addr(end, &t2) < 0))
             return -1;
 
+        /* legacy check that everything except the last two bytes are
+         * the same
+         */
         for (i = 0; i < 7; i++) {
             if (t1[i] != t2[i])
                 return -1;
diff --git a/src/util/virsocketaddr.h b/src/util/virsocketaddr.h
index 99ab46f..9e2680a 100644
--- a/src/util/virsocketaddr.h
+++ b/src/util/virsocketaddr.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2009-2013 Red Hat, Inc.
+ * Copyright (C) 2009-2013, 2015 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
@@ -96,7 +96,9 @@ int virSocketAddrSetPort(virSocketAddrPtr addr, int port);
 int virSocketAddrGetPort(virSocketAddrPtr addr);
 
 int virSocketAddrGetRange(virSocketAddrPtr start,
-                          virSocketAddrPtr end);
+                          virSocketAddrPtr end,
+                          virSocketAddrPtr network,
+                          int prefix);
 
 int virSocketAddrIsNetmask(virSocketAddrPtr netmask);
 
diff --git a/tests/networkxml2xmlupdatein/dhcp-range-10.xml b/tests/networkxml2xmlupdatein/dhcp-range-10.xml
new file mode 100644
index 0000000..ed775c8
--- /dev/null
+++ b/tests/networkxml2xmlupdatein/dhcp-range-10.xml
@@ -0,0 +1 @@
+<range start='10.0.0.10' end='10.0.0.100'/>
diff --git a/tests/networkxml2xmlupdatein/dhcp-range.xml b/tests/networkxml2xmlupdatein/dhcp-range.xml
index ed775c8..d5e283c 100644
--- a/tests/networkxml2xmlupdatein/dhcp-range.xml
+++ b/tests/networkxml2xmlupdatein/dhcp-range.xml
@@ -1 +1 @@
-<range start='10.0.0.10' end='10.0.0.100'/>
+<range start='192.168.122.10' end='192.168.122.100'/>
diff --git a/tests/networkxml2xmlupdateout/dhcp6host-routed-network-another-range.xml b/tests/networkxml2xmlupdateout/dhcp6host-routed-network-another-range.xml
index ee6eb7a..4a1360d 100644
--- a/tests/networkxml2xmlupdateout/dhcp6host-routed-network-another-range.xml
+++ b/tests/networkxml2xmlupdateout/dhcp6host-routed-network-another-range.xml
@@ -8,7 +8,7 @@
   <mac address='12:34:56:78:9a:bc'/>
   <ip address='192.168.122.1' netmask='255.255.255.0'>
     <dhcp>
-      <range start='10.0.0.10' end='10.0.0.100'/>
+      <range start='192.168.122.10' end='192.168.122.100'/>
       <host mac='00:16:3e:77:e2:ed' name='a.example.com' ip='192.168.122.10'/>
       <host mac='00:16:3e:3e:a9:1a' name='b.example.com' ip='192.168.122.11'/>
     </dhcp>
diff --git a/tests/networkxml2xmlupdateout/dhcp6host-routed-network-range.xml b/tests/networkxml2xmlupdateout/dhcp6host-routed-network-range.xml
index ee6eb7a..4a1360d 100644
--- a/tests/networkxml2xmlupdateout/dhcp6host-routed-network-range.xml
+++ b/tests/networkxml2xmlupdateout/dhcp6host-routed-network-range.xml
@@ -8,7 +8,7 @@
   <mac address='12:34:56:78:9a:bc'/>
   <ip address='192.168.122.1' netmask='255.255.255.0'>
     <dhcp>
-      <range start='10.0.0.10' end='10.0.0.100'/>
+      <range start='192.168.122.10' end='192.168.122.100'/>
       <host mac='00:16:3e:77:e2:ed' name='a.example.com' ip='192.168.122.10'/>
       <host mac='00:16:3e:3e:a9:1a' name='b.example.com' ip='192.168.122.11'/>
     </dhcp>
diff --git a/tests/networkxml2xmlupdatetest.c b/tests/networkxml2xmlupdatetest.c
index af697bb..0241378 100644
--- a/tests/networkxml2xmlupdatetest.c
+++ b/tests/networkxml2xmlupdatetest.c
@@ -202,6 +202,11 @@ mymain(void)
                   "dhcp6host-routed-network-range",
                   VIR_NETWORK_UPDATE_COMMAND_ADD_FIRST,
                   0);
+    DO_TEST_INDEX_FAIL("add-dhcp-range-outside-net",
+                       "dhcp-range-10",
+                       "dhcp6host-routed-network",
+                       VIR_NETWORK_UPDATE_COMMAND_ADD_FIRST,
+                       0);
     DO_TEST_INDEX("append-dhcp-range",
                   "dhcp-range",
                   "dhcp6host-routed-network",
diff --git a/tests/sockettest.c b/tests/sockettest.c
index 0d348d9..84170d5 100644
--- a/tests/sockettest.c
+++ b/tests/sockettest.c
@@ -1,7 +1,7 @@
 /*
  * sockettest.c: Testing for src/util/network.c APIs
  *
- * Copyright (C) 2010-2011, 2014 Red Hat, Inc.
+ * Copyright (C) 2010-2011, 2014, 2015 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
@@ -86,17 +86,22 @@ static int testFormatHelper(const void *opaque)
 }
 
 
-static int testRange(const char *saddrstr, const char *eaddrstr, int size, bool pass)
+static int
+testRange(const char *saddrstr, const char *eaddrstr,
+          const char *netstr, int prefix, int size, bool pass)
 {
     virSocketAddr saddr;
     virSocketAddr eaddr;
+    virSocketAddr netaddr;
 
     if (virSocketAddrParse(&saddr, saddrstr, AF_UNSPEC) < 0)
         return -1;
     if (virSocketAddrParse(&eaddr, eaddrstr, AF_UNSPEC) < 0)
         return -1;
+    if (virSocketAddrParse(&netaddr, netstr, AF_UNSPEC) < 0)
+        return -1;
 
-    int gotsize = virSocketAddrGetRange(&saddr, &eaddr);
+    int gotsize = virSocketAddrGetRange(&saddr, &eaddr, &netaddr, prefix);
     VIR_DEBUG("Size want %d vs got %d", size, gotsize);
     if (gotsize < 0 || gotsize != size) {
         return pass ? -1 : 0;
@@ -105,16 +110,23 @@ static int testRange(const char *saddrstr, const char *eaddrstr, int size, bool
     }
 }
 
+
 struct testRangeData {
     const char *saddr;
     const char *eaddr;
+    const char *netaddr;
+    int prefix;
     int size;
     bool pass;
 };
+
+
 static int testRangeHelper(const void *opaque)
 {
     const struct testRangeData *data = opaque;
-    return testRange(data->saddr, data->eaddr, data->size, data->pass);
+    return testRange(data->saddr, data->eaddr,
+                     data->netaddr, data->prefix,
+                     data->size, data->pass);
 }
 
 
@@ -287,10 +299,12 @@ mymain(void)
             ret = -1;                                                   \
     } while (0)
 
-#define DO_TEST_RANGE(saddr, eaddr, size, pass)                         \
+#define DO_TEST_RANGE(saddr, eaddr, netaddr, prefix, size, pass)        \
     do {                                                                \
-        struct testRangeData data = { saddr, eaddr, size, pass };       \
-        if (virtTestRun("Test range " saddr " -> " eaddr " size " #size, \
+        struct testRangeData data                                       \
+           = { saddr, eaddr, netaddr, prefix, size, pass };             \
+        if (virtTestRun("Test range " saddr " -> " eaddr "(" netaddr \
+                        "/" #prefix") size " #size, \
                         testRangeHelper, &data) < 0)                    \
             ret = -1;                                                   \
     } while (0)
@@ -357,17 +371,22 @@ mymain(void)
     DO_TEST_PARSE_AND_FORMAT("::1", AF_UNIX, false);
     DO_TEST_PARSE_AND_FORMAT("::ffff", AF_UNSPEC, true);
 
-    DO_TEST_RANGE("192.168.122.1", "192.168.122.1", 1, true);
-    DO_TEST_RANGE("192.168.122.1", "192.168.122.20", 20, true);
-    DO_TEST_RANGE("192.168.122.0", "192.168.122.255", 256, true);
-    DO_TEST_RANGE("192.168.122.20", "192.168.122.1", -1, false);
-    DO_TEST_RANGE("10.0.0.1", "192.168.122.20", -1, false);
-    DO_TEST_RANGE("192.168.122.20", "10.0.0.1", -1, false);
-
-    DO_TEST_RANGE("2000::1", "2000::1", 1, true);
-    DO_TEST_RANGE("2000::1", "2000::2", 2, true);
-    DO_TEST_RANGE("2000::2", "2000::1", -1, false);
-    DO_TEST_RANGE("2000::1", "9001::1", -1, false);
+    DO_TEST_RANGE("192.168.122.1", "192.168.122.1", "192.168.122.1", 24, 1, true);
+    DO_TEST_RANGE("192.168.122.1", "192.168.122.20", "192.168.122.22", 24, 20, true);
+    DO_TEST_RANGE("192.168.122.0", "192.168.122.254", "192.168.122.1", 24, -1, false);
+    DO_TEST_RANGE("192.168.122.1", "192.168.122.255", "192.168.122.1", 24, -1, false);
+    DO_TEST_RANGE("192.168.122.0", "192.168.122.255", "192.168.122.1", 16, 256, true);
+    DO_TEST_RANGE("192.168.122.20", "192.168.122.1", "192.168.122.1", 24, -1, false);
+    DO_TEST_RANGE("10.0.0.1", "192.168.122.20", "192.168.122.1", 24, -1, false);
+    DO_TEST_RANGE("192.168.122.20", "10.0.0.1", "192.168.122.1", 24, -1, false);
+    DO_TEST_RANGE("172.16.0.50", "172.16.0.254", "1.2.3.4", 8, -1, false);
+    DO_TEST_RANGE("192.168.122.1", "192.168.123.20", "192.168.122.22", 24, -1, false);
+    DO_TEST_RANGE("192.168.122.1", "192.168.123.20", "192.168.122.22", 23, 276, true);
+
+    DO_TEST_RANGE("2000::1", "2000::1", "2000::1", 64, 1, true);
+    DO_TEST_RANGE("2000::1", "2000::2", "2000::1", 64, 2, true);
+    DO_TEST_RANGE("2000::2", "2000::1", "2000::1", 64, -1, false);
+    DO_TEST_RANGE("2000::1", "9001::1", "2000::1", 64, -1, false);
 
     DO_TEST_NETMASK("192.168.122.1", "192.168.122.2",
                     "255.255.255.0", true);
-- 
2.1.0




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