publicsuffix: change node table entry size to 40 bits

The latest public suffix list overflows the 15 bits of text offset,
and we're out of bits in the node entry. Bump the node size to
40 bits.

Fixes golang/go#55849

Change-Id: Ia4b1b23799d569e4fbcfe38b4d5d9761b76f2d73
Reviewed-on: https://go-review.googlesource.com/c/net/+/434695
Reviewed-by: Nigel Tao <nigeltao@golang.org>
Auto-Submit: Damien Neil <dneil@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Nigel Tao (INACTIVE; USE @golang.org INSTEAD) <nigeltao@google.com>
Run-TryBot: Damien Neil <dneil@google.com>

Author: neild

publicsuffix/gen.go

@@ -37,10 +37,14 @@ import (
 )
 
 const (
-	// These sum of these four values must be no greater than 32.
+	// This must be a multiple of 8 and no greater than 64.
+	// Update nodeValue in list.go if this changes.
+	nodesBits = 40
+
+	// These sum of these four values must be no greater than nodesBits.
 	nodesBitsChildren   = 10
 	nodesBitsICANN      = 1
-	nodesBitsTextOffset = 15
+	nodesBitsTextOffset = 16
 	nodesBitsTextLength = 6
 
 	// These sum of these four values must be no greater than 32.
@@ -97,7 +101,7 @@ const (
 )
 
 var (
-	labelEncoding = map[string]uint32{}
+	labelEncoding = map[string]uint64{}
 	labelsList    = []string{}
 	labelsMap     = map[string]bool{}
 	rules         = []string{}
@@ -127,7 +131,13 @@ func main() {
 
 func main1() error {
 	flag.Parse()
-	if nodesBitsTextLength+nodesBitsTextOffset+nodesBitsICANN+nodesBitsChildren > 32 {
+	if nodesBits > 64 {
+		return fmt.Errorf("nodesBits is too large")
+	}
+	if nodesBits%8 != 0 {
+		return fmt.Errorf("nodesBits must be a multiple of 8")
+	}
+	if nodesBitsTextLength+nodesBitsTextOffset+nodesBitsICANN+nodesBitsChildren > nodesBits {
 		return fmt.Errorf("not enough bits to encode the nodes table")
 	}
 	if childrenBitsLo+childrenBitsHi+childrenBitsNodeType+childrenBitsWildcard > 32 {
@@ -312,6 +322,7 @@ package publicsuffix
 const version = %q
 
 const (
+	nodesBits           = %d
 	nodesBitsChildren   = %d
 	nodesBitsICANN      = %d
 	nodesBitsTextOffset = %d
@@ -334,6 +345,7 @@ const numTLD = %d
 
 `
 	fmt.Fprintf(w, header, *version,
+		nodesBits,
 		nodesBitsChildren, nodesBitsICANN, nodesBitsTextOffset, nodesBitsTextLength,
 		childrenBitsWildcard, childrenBitsNodeType, childrenBitsHi, childrenBitsLo,
 		nodeTypeNormal, nodeTypeException, nodeTypeParentOnly, len(n.children))
@@ -354,7 +366,7 @@ const numTLD = %d
 		if length >= 1<<nodesBitsTextLength {
 			return fmt.Errorf("text length %d is too large, or nodeBitsTextLength is too small", length)
 		}
-		labelEncoding[label] = uint32(offset)<<nodesBitsTextLength | uint32(length)
+		labelEncoding[label] = uint64(offset)<<nodesBitsTextLength | uint64(length)
 	}
 	fmt.Fprintf(w, "// Text is the combined text of all labels.\nconst text = ")
 	for len(text) > 0 {
@@ -372,9 +384,9 @@ const numTLD = %d
 
 	fmt.Fprintf(w, `
 
-// nodes is the list of nodes. Each node is represented as a uint32, which
-// encodes the node's children, wildcard bit and node type (as an index into
-// the children array), ICANN bit and text.
+// nodes is the list of nodes. Each node is represented as a %v-bit integer,
+// which encodes the node's children, wildcard bit and node type (as an index
+// into the children array), ICANN bit and text.
 //
 // If the table was generated with the -comments flag, there is a //-comment
 // after each node's data. In it is the nodes-array indexes of the children,
@@ -383,15 +395,16 @@ const numTLD = %d
 // nodes that have children but don't match a domain label in their own right.
 // An I denotes an ICANN domain.
 //
-// The layout within the uint32, from MSB to LSB, is:
+// The layout within the node, from MSB to LSB, is:
 //	[%2d bits] unused
 //	[%2d bits] children index
 //	[%2d bits] ICANN bit
 //	[%2d bits] text index
 //	[%2d bits] text length
-var nodes = [...]uint32{
+var nodes = [...]uint8{
 `,
-		32-nodesBitsChildren-nodesBitsICANN-nodesBitsTextOffset-nodesBitsTextLength,
+		nodesBits,
+		nodesBits-nodesBitsChildren-nodesBitsICANN-nodesBitsTextOffset-nodesBitsTextLength,
 		nodesBitsChildren, nodesBitsICANN, nodesBitsTextOffset, nodesBitsTextLength)
 	if err := n.walk(w, printNode); err != nil {
 		return err
@@ -558,14 +571,17 @@ func printNode(w io.Writer, n *node) error {
 		if c.icann {
 			encoding |= 1 << (nodesBitsTextLength + nodesBitsTextOffset)
 		}
-		encoding |= uint32(c.childrenIndex) << (nodesBitsTextLength + nodesBitsTextOffset + nodesBitsICANN)
+		encoding |= uint64(c.childrenIndex) << (nodesBitsTextLength + nodesBitsTextOffset + nodesBitsICANN)
+		for i := nodesBits - 8; i >= 0; i -= 8 {
+			fmt.Fprintf(w, "0x%02x, ", (encoding>>i)&0xff)
+		}
 		if *comments {
-			fmt.Fprintf(w, "0x%08x, // n0x%04x c0x%04x (%s)%s %s %s %s\n",
-				encoding, c.nodesIndex, c.childrenIndex, s, wildcardStr(c.wildcard),
+			fmt.Fprintf(w, "// n0x%04x c0x%04x (%s)%s %s %s %s\n",
+				c.nodesIndex, c.childrenIndex, s, wildcardStr(c.wildcard),
 				nodeTypeStr(c.nodeType), icannStr(c.icann), c.label,
 			)
 		} else {
-			fmt.Fprintf(w, "0x%x,\n", encoding)
+			fmt.Fprintf(w, "\n")
 		}
 	}
 	return nil

publicsuffix/list.go

@@ -101,7 +101,7 @@ loop:
 			break
 		}
 
-		u := nodes[f] >> (nodesBitsTextOffset + nodesBitsTextLength)
+		u := uint32(nodeValue(f) >> (nodesBitsTextOffset + nodesBitsTextLength))
 		icannNode = u&(1<<nodesBitsICANN-1) != 0
 		u >>= nodesBitsICANN
 		u = children[u&(1<<nodesBitsChildren-1)]
@@ -154,9 +154,18 @@ func find(label string, lo, hi uint32) uint32 {
 	return notFound
 }
 
+func nodeValue(i uint32) uint64 {
+	off := uint64(i * (nodesBits / 8))
+	return uint64(nodes[off])<<32 |
+		uint64(nodes[off+1])<<24 |
+		uint64(nodes[off+2])<<16 |
+		uint64(nodes[off+3])<<8 |
+		uint64(nodes[off+4])
+}
+
 // nodeLabel returns the label for the i'th node.
 func nodeLabel(i uint32) string {
-	x := nodes[i]
+	x := nodeValue(i)
 	length := x & (1<<nodesBitsTextLength - 1)
 	x >>= nodesBitsTextLength
 	offset := x & (1<<nodesBitsTextOffset - 1)