From 98143cfc18f95eb4057587c1bdb4aa3b5e3b2e20 Mon Sep 17 00:00:00 2001
From: Robert Varga <robert.varga@pantheon.tech>
Date: Mon, 6 Jan 2020 18:41:24 +0100
Subject: [PATCH] Add IPv4 address bridges to primitive int

Interfacing Ipv4Address(NoZone) with plain int is useful when
we we want to interface with byte streams, such as DataInput
or Netty's ByteBuf. This adds the methods to do so.

JIRA: MDSAL-509
Change-Id: Icce95e4a94ae41be4fc2aee352f83655ea55e89f
Signed-off-by: Robert Varga <robert.varga@pantheon.tech>
---
 .../model/ietf/util/AbstractIetfInetUtil.java | 56 +++++++++++++++++++
 .../ietf/util/AbstractIetfInetUtilTest.java   | 26 ++++++++-
 2 files changed, 81 insertions(+), 1 deletion(-)

diff --git a/model/ietf/ietf-type-util/src/main/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtil.java b/model/ietf/ietf-type-util/src/main/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtil.java
index a67cc8f13e..88da958305 100644
--- a/model/ietf/ietf-type-util/src/main/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtil.java
+++ b/model/ietf/ietf-type-util/src/main/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtil.java
@@ -250,6 +250,16 @@ public abstract class AbstractIetfInetUtil<A4, A4NZ extends A4, P4, A6, A6NZ ext
         return address4Factory.newInstance(addr.getHostAddress());
     }
 
+    /**
+     * Create an Ipv4Address by interpreting input 32 bits as an IPv4 address in big-endian format.
+     *
+     * @param bits 32 bits, big endian
+     * @return An Ipv4Address object
+     */
+    public final @NonNull A4 ipv4AddressFor(final int bits) {
+        return address4Factory.newInstance(addressString(bits));
+    }
+
     /**
      * Create an Ipv4AddressNoZone by interpreting input bytes as an IPv4 address.
      *
@@ -276,6 +286,16 @@ public abstract class AbstractIetfInetUtil<A4, A4NZ extends A4, P4, A6, A6NZ ext
         return address4NoZoneFactory.newInstance(addr.getHostAddress());
     }
 
+    /**
+     * Create an Ipv4AddressNoZone by interpreting input 32 bits as an IPv4 address in big-endian format.
+     *
+     * @param bits 32 bits, big endian
+     * @return An Ipv4AddressNoZone object
+     */
+    public final @NonNull A4NZ ipv4AddressNoZoneFor(final int bits) {
+        return address4NoZoneFactory.newInstance(addressString(bits));
+    }
+
     public final @NonNull A4 ipv4AddressFrom(final @NonNull P4 prefix) {
         return prefixToAddress(address4Factory, ipv4PrefixString(prefix));
     }
@@ -294,6 +314,12 @@ public abstract class AbstractIetfInetUtil<A4, A4NZ extends A4, P4, A6, A6NZ ext
         return ipv4StringBytes(str, percent == -1 ? str.length() : percent);
     }
 
+    public final int ipv4AddressBits(final @NonNull A4 addr) {
+        final String str = ipv4AddressString(addr);
+        final int percent = str.indexOf('%');
+        return ipv4StringBits(str, percent == -1 ? str.length() : percent);
+    }
+
     public final byte @NonNull[] ipv4AddressNoZoneBytes(final @NonNull A4NZ addr) {
         /*
          * This implementation relies heavily on the input string having been validated to comply with
@@ -303,12 +329,33 @@ public abstract class AbstractIetfInetUtil<A4, A4NZ extends A4, P4, A6, A6NZ ext
         return ipv4StringBytes(str, str.length());
     }
 
+    public final int ipv4AddressNoZoneBits(final @NonNull A4NZ addr) {
+        final String str = ipv4AddressString(addr);
+        return ipv4StringBits(str, str.length());
+    }
+
     private static byte @NonNull[] ipv4StringBytes(final String str, final int limit) {
         final byte[] bytes = new byte[INET4_LENGTH];
         Ipv4Utils.fillIpv4Bytes(bytes, 0, str, 0, limit);
         return bytes;
     }
 
+    private static int ipv4StringBits(final String str, final int limit) {
+        int prev = 0;
+        int current = 0;
+        for (int i = 0, shift = 24; i < limit; ++i) {
+            final char c = str.charAt(i);
+            if (c == '.') {
+                prev |= current << shift;
+                shift -= 8;
+                current = 0;
+            } else {
+                current = 10 * current + c - '0';
+            }
+        }
+        return prev | current;
+    }
+
     /**
      * Create a /32 Ipv4Prefix by interpreting input bytes as an IPv4 address.
      *
@@ -648,6 +695,15 @@ public abstract class AbstractIetfInetUtil<A4, A4NZ extends A4, P4, A6, A6NZ ext
         }
     }
 
+    private static String addressString(final int bits) {
+        return new StringBuilder(15)
+                .append(bits >>> 24).append('.')
+                .append(bits >>> 16 & 0xFF).append('.')
+                .append(bits >>> 8 & 0xFF).append('.')
+                .append(bits & 0xFF)
+                .toString();
+    }
+
     static String addressStringV4(final byte @NonNull[] bytes) {
         final StringBuilder sb = new StringBuilder(15);
         appendIpv4String(sb, bytes);
diff --git a/model/ietf/ietf-type-util/src/test/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtilTest.java b/model/ietf/ietf-type-util/src/test/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtilTest.java
index ba19adc47f..dee4d2d45d 100644
--- a/model/ietf/ietf-type-util/src/test/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtilTest.java
+++ b/model/ietf/ietf-type-util/src/test/java/org/opendaylight/mdsal/model/ietf/util/AbstractIetfInetUtilTest.java
@@ -175,4 +175,28 @@ public class AbstractIetfInetUtilTest {
         }).when(ipClass).getValue();
         UTIL.inet6AddressFor(ipClass);
     }
-}
\ No newline at end of file
+
+    @Test
+    public void testIpv4AddressForBits() {
+        assertEquals("1.2.3.4", UTIL.ipv4AddressFor(0x01020304).getValue());
+        assertEquals("255.255.255.255", UTIL.ipv4AddressFor(0xFFFFFFFF).getValue());
+    }
+
+    @Test
+    public void testIpv4AddressNoZoneForBits() {
+        assertEquals("1.2.3.4", UTIL.ipv4AddressNoZoneFor(0x01020304).getValue());
+        assertEquals("255.255.255.255", UTIL.ipv4AddressNoZoneFor(0xFFFFFFFF).getValue());
+    }
+
+    @Test
+    public void testIpv4AddressBits() {
+        assertEquals(0x01020304, UTIL.ipv4AddressBits(new IpClass("1.2.3.4")));
+        assertEquals(0xFFFFFFFF, UTIL.ipv4AddressBits(new IpClass("255.255.255.255")));
+    }
+
+    @Test
+    public void testIpv4AddressNoZoneBits() {
+        assertEquals(0x01020304, UTIL.ipv4AddressNoZoneBits(new IpClass("1.2.3.4")));
+        assertEquals(0xFFFFFFFF, UTIL.ipv4AddressNoZoneBits(new IpClass("255.255.255.255")));
+    }
+}
-- 
2.36.6