From 63b16a5d5cfd3b41f596daccd56d32b2548ec119 Mon Sep 17 00:00:00 2001
From: Andrey Konovalov <andreyknvl@google.com>
Date: Wed, 25 Jan 2017 16:18:05 +0100
Subject: prog, sys: add csum type, embed checksums for ipv4 packets

This change adds a `csum[kind, type]` type.
The only available kind right now is `ipv4`.
Using `csum[ipv4, int16be]` in `ipv4_header` makes syzkaller calculate
and embed correct checksums into ipv4 packets.
---
 sys/decl.go  | 13 ++++++++++++-
 sys/test.txt | 19 +++++++++++++++++++
 sys/vnet.txt |  7 +++----
 3 files changed, 34 insertions(+), 5 deletions(-)

(limited to 'sys')

diff --git a/sys/decl.go b/sys/decl.go
index 3c98d1038..14f1105de 100644
--- a/sys/decl.go
+++ b/sys/decl.go
@@ -191,6 +191,17 @@ type ProcType struct {
 	ValuesPerProc uint64
 }
 
+type CsumKind int
+
+const (
+	CsumIPv4 CsumKind = iota
+)
+
+type CsumType struct {
+	IntTypeCommon
+	Kind CsumKind
+}
+
 type VmaType struct {
 	TypeCommon
 	RangeBegin int64 // in pages
@@ -573,7 +584,7 @@ func ForeachType(meta *Call, f func(Type)) {
 				rec(opt)
 			}
 		case *ResourceType, *BufferType, *VmaType, *LenType,
-			*FlagsType, *ConstType, *IntType, *ProcType:
+			*FlagsType, *ConstType, *IntType, *ProcType, *CsumType:
 		default:
 			panic("unknown type")
 		}
diff --git a/sys/test.txt b/sys/test.txt
index 0ce7ec819..75b8428fd 100644
--- a/sys/test.txt
+++ b/sys/test.txt
@@ -389,3 +389,22 @@ syz_bf_struct1 {
 
 syz_test$bf0(a0 ptr[in, syz_bf_struct0])
 syz_test$bf1(a0 ptr[in, syz_bf_struct1])
+
+# Checksums
+
+syz_test$csum_encode(a0 ptr[in, syz_csum_encode])
+syz_test$csum_ipv4(a0 ptr[in, syz_csum_ipv4])
+
+syz_csum_encode {
+	f0	int16
+	f1	int16be
+	f2	array[int32, 0:4]
+	f3	int8:4
+	f4	int8:4
+	f5	array[int8, 4]
+} [packed]
+
+syz_csum_ipv4 {
+	f0	csum[ipv4, int16]
+	f1	syz_csum_encode
+} [packed]
diff --git a/sys/vnet.txt b/sys/vnet.txt
index 67344b186..a959f8909 100644
--- a/sys/vnet.txt
+++ b/sys/vnet.txt
@@ -149,14 +149,13 @@ ipv4_header {
 	version		const[4, int8:4]
 	ecn		int8:2
 	dscp		int8:6
-	tot_len		len[ipv4_packet, int16be]
-	identification	int16be
+	total_len	len[ipv4_packet, int16be]
+	id		int16be
 	frag_off	int16:13
 	flags		int16:3
 	ttl		int8
 	protocol	flags[ipv4_types, int8]
-# TODO: embed correct checksum
-	csum		const[0, int16]
+	csum		csum[ipv4, int16be]
 	src_ip		ipv4_addr
 	dst_ip		ipv4_addr
 	options		ipv4_options
-- 
cgit mrf-deployment