Add to_subnet bif (fixes #782).

Also fix IPAddr::Mask/ReverseMask not allowing argument of 0.

And clarified return value of to_addr bif when the input string
does not parse into a valid IP address.

src/IPAddr.cc

@@ -11,7 +11,7 @@ const uint8_t IPAddr::v4_mapped_prefix[12] = { 0, 0, 0, 0,
 
 void IPAddr::Mask(int top_bits_to_keep)
 	{
-	if ( top_bits_to_keep <= 0 || top_bits_to_keep > 128 )
+	if ( top_bits_to_keep < 0 || top_bits_to_keep > 128 )
 		{
 		reporter->Error("Bad IPAddr::Mask value %d", top_bits_to_keep);
 		return;
@@ -40,7 +40,7 @@ void IPAddr::Mask(int top_bits_to_keep)
 
 void IPAddr::ReverseMask(int top_bits_to_chop)
 	{
-	if ( top_bits_to_chop <= 0 || top_bits_to_chop > 128 )
+	if ( top_bits_to_chop < 0 || top_bits_to_chop > 128 )
 		{
 		reporter->Error("Bad IPAddr::ReverseMask value %d", top_bits_to_chop);
 		return;

src/Val.cc

@@ -911,11 +911,18 @@ bool AddrVal::DoUnserialize(UnserialInfo* info)
 
 SubNetVal::SubNetVal(const char* text) : Val(TYPE_SUBNET)
 	{
-	const char* sep = strchr(text, '/');
+	string s(text);
-	if ( ! sep )
+	size_t slash_loc = s.find('/');
-		Internal("separator missing in SubNetVal::SubNetVal");
+	if ( slash_loc == string::npos )
-
+		{
-	val.subnet_val = new IPPrefix(text, atoi(sep+1));
+		reporter->Error("Bad string in SubNetVal ctor: %s", text);
+		val.subnet_val = new IPPrefix();
+		}
+	else
+		{
+		val.subnet_val = new IPPrefix(s.substr(0, slash_loc),
+		                              atoi(s.substr(slash_loc + 1).c_str()));
+		}
 	}
 
 SubNetVal::SubNetVal(const char* text, int width) : Val(TYPE_SUBNET)

src/bro.bif

@@ -2135,7 +2135,7 @@ function counts_to_addr%(v: index_vec%): addr
 ##
 ## Returns: The :bro:type:`string` *str* as :bro:type:`int`.
 ##
-## .. bro:see:: to_addr to_port
+## .. bro:see:: to_addr to_port to_subnet
 function to_int%(str: string%): int
 	%{
 	const char* s = str->CheckString();
@@ -2192,7 +2192,7 @@ function double_to_count%(d: double%): count
 ## Returns: The :bro:type:`string` *str* as unsigned integer or if in invalid
 ##          format.
 ##
-## .. bro:see:: to_addr to_int to_port
+## .. bro:see:: to_addr to_int to_port to_subnet
 function to_count%(str: string%): count
 	%{
 	const char* s = str->CheckString();
@@ -2287,9 +2287,11 @@ function count_to_port%(num: count, proto: transport_proto%): port
 ##
 ## ip: The :bro:type:`string` to convert.
 ##
-## Returns: The :bro:type:`string` *ip* as :bro:type:`addr`.
+## Returns: The :bro:type:`string` *ip* as :bro:type:`addr` or the unspecified
+##          address ``::`` if the input string does not parse correctly.
 ##
 ## .. bro:see:: to_count to_int to_port count_to_v4_addr raw_bytes_to_v4_addr
+##    to_subnet
 function to_addr%(ip: string%): addr
 	%{
 	char* s = ip->AsString()->Render();
@@ -2298,13 +2300,30 @@ function to_addr%(ip: string%): addr
 	return ret;
 	%}
 
+## Converts a :bro:type:`string` to a :bro:type:`subnet`.
+##
+## sn: The subnet to convert.
+##
+## Returns: The *sn* string as a :bro:type:`subnet` or the unspecified subnet
+##          ``::/0`` if the input string does not parse correctly.
+##
+## .. bro:see:: to_count to_int to_port count_to_v4_addr raw_bytes_to_v4_addr
+##    to_addr
+function to_subnet%(sn: string%): subnet
+	%{
+	char* s = sn->AsString()->Render();
+	Val* ret = new SubNetVal(s);
+	delete [] s;
+	return ret;
+	%}
+
 ## Converts a :bro:type:`count` to an :bro:type:`addr`.
 ##
 ## ip: The :bro:type:`count` to convert.
 ##
 ## Returns: The :bro:type:`count` *ip* as :bro:type:`addr`.
 ##
-## .. bro:see:: raw_bytes_to_v4_addr to_addr
+## .. bro:see:: raw_bytes_to_v4_addr to_addr to_subnet
 function count_to_v4_addr%(ip: count%): addr
 	%{
 	if ( ip > 4294967295LU )
@@ -2324,7 +2343,7 @@ function count_to_v4_addr%(ip: count%): addr
 ##
 ## Returns: The byte :bro:type:`string` *ip* as :bro:type:`addr`.
 ##
-## .. bro:see:: raw_bytes_to_v4_addr to_addr
+## .. bro:see:: raw_bytes_to_v4_addr to_addr to_subnet
 function raw_bytes_to_v4_addr%(b: string%): addr
 	%{
 	uint32 a = 0;
@@ -2347,7 +2366,7 @@ function raw_bytes_to_v4_addr%(b: string%): addr
 ##
 ## Returns: A :bro:type:`port` converted from *s*.
 ##
-## .. bro:see:: to_addr to_count to_int
+## .. bro:see:: to_addr to_count to_int to_subnet
 function to_port%(s: string%): port
     %{
     int port = 0;

testing/btest/Baseline/bifs.to_addr/error

@@ -0,0 +1 @@
+error: Bad IP address: not an IP

testing/btest/Baseline/bifs.to_addr/output

@@ -6,3 +6,4 @@ to_addr(10.20.30.40) = 10.20.30.40 (SUCCESS)
 to_addr(100.200.30.40) = 100.200.30.40 (SUCCESS)
 to_addr(10.0.0.0) = 10.0.0.0 (SUCCESS)
 to_addr(10.00.00.000) = 10.0.0.0 (SUCCESS)
+to_addr(not an IP) = :: (SUCCESS)

testing/btest/Baseline/bifs.to_subnet/error

@@ -0,0 +1 @@
+error: Bad string in SubNetVal ctor: 10.0.0.0

testing/btest/Baseline/bifs.to_subnet/output

@@ -0,0 +1,3 @@
+10.0.0.0/8, T
+2607:f8b0::/32, T
+::/0, T

testing/btest/bifs/to_addr.bro

@@ -1,5 +1,6 @@
-# @TEST-EXEC: bro %INPUT >output
+# @TEST-EXEC: bro -b %INPUT >output 2>error
 # @TEST-EXEC: btest-diff output
+# @TEST-EXEC: btest-diff error
 
 function test_to_addr(ip: string, expect: addr)
 	{
@@ -16,3 +17,4 @@ test_to_addr("10.20.30.40", 10.20.30.40);
 test_to_addr("100.200.30.40", 100.200.30.40);
 test_to_addr("10.0.0.0", 10.0.0.0);
 test_to_addr("10.00.00.000", 10.0.0.0);
+test_to_addr("not an IP", ::);

testing/btest/bifs/to_subnet.bro

@@ -0,0 +1,11 @@
+# @TEST-EXEC: bro -b %INPUT >output 2>error
+# @TEST-EXEC: btest-diff output
+# @TEST-EXEC: btest-diff error
+
+global sn: subnet;
+sn = to_subnet("10.0.0.0/8");
+print sn, sn == 10.0.0.0/8;
+sn = to_subnet("2607:f8b0::/32");
+print sn, sn == 2607:f8b0::/32;
+sn = to_subnet("10.0.0.0");
+print sn, sn == ::/0;