prog, sys: add tcp packets descriptions

Also embed tcp checksums into packets.

8 files changed, 238 insertions, 6 deletions

diff --git a/sys/decl.go b/sys/decl.go
index 57d788576..ba1806836 100644
--- a/sys/decl.go
+++ b/sys/decl.go
@@ -194,6 +194,7 @@ type CsumKind int
 
 const (
 	CsumIPv4 CsumKind = iota
+	CsumTCP
 )
 
 type CsumType struct {
diff --git a/sys/socket.txt b/sys/socket.txt
index c123a5db9..9e86c4de7 100644
--- a/sys/socket.txt
+++ b/sys/socket.txt
@@ -138,6 +138,7 @@ sockaddr_in {
 	family	const[AF_INET, int16]
 	port	proc[int16be, 20000, 4]
 	addr	in_addr
+	pad     array[const[0, int8], 8]
 }
 
 sockaddr_storage_in {
@@ -193,6 +194,28 @@ cmsghdr {
 
 
 
+# AF_INET: TCP support
+
+resource sock_tcp[sock]
+
+socket$tcp(domain const[AF_INET], type const[SOCK_STREAM], proto const[0]) sock_tcp
+socketpair$tcp(domain const[AF_INET], type const[SOCK_STREAM], proto const[0], fds ptr[out, tcp_pair])
+accept$tcp(fd sock_tcp, peer ptr[out, sockaddr_in, opt], peerlen ptr[inout, len[peer, int32]]) sock_tcp
+accept4$tcp(fd sock_tcp, peer ptr[out, sockaddr_in, opt], peerlen ptr[inout, len[peer, int32]], flags flags[accept_flags]) sock_tcp
+bind$tcp(fd sock_tcp, addr ptr[in, sockaddr_in], addrlen len[addr])
+connect$tcp(fd sock_tcp, addr ptr[in, sockaddr_in], addrlen len[addr])
+sendto$tcp(fd sock_tcp, buf buffer[in], len len[buf], f flags[send_flags], addr ptr[in, sockaddr_in, opt], addrlen len[addr])
+recvfrom$tcp(fd sock_tcp, buf buffer[out], len len[buf], f flags[recv_flags], addr ptr[in, sockaddr_in, opt], addrlen len[addr])
+getsockname$tcp(fd sock_tcp, addr ptr[out, sockaddr_in], addrlen ptr[inout, len[addr, int32]])
+getpeername$tcp(fd sock_tcp, peer ptr[out, sockaddr_in], peerlen ptr[inout, len[peer, int32]])
+
+tcp_pair {
+	f0	sock_tcp
+	f1	sock_tcp
+}
+
+
+
 # AF_UNIX support.
 
 resource sock_unix[sock]
diff --git a/sys/sys.txt b/sys/sys.txt
index be43f0786..b4e6bdf58 100644
--- a/sys/sys.txt
+++ b/sys/sys.txt
@@ -941,7 +941,7 @@ in_addr [
 	loopback	const[0x7f000001, int32be]
 # 255.255.255.255
 	broadcast	const[0xffffffff, int32be]
-}
+]
 
 in6_addr_empty {
 	a0		const[0, int64be]
diff --git a/sys/test.txt b/sys/test.txt
index 75b8428fd..932ddac01 100644
--- a/sys/test.txt
+++ b/sys/test.txt
@@ -393,7 +393,8 @@ 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_test$csum_ipv4(a0 ptr[in, syz_csum_ipv4_header])
+syz_test$csum_ipv4_tcp(a0 ptr[in, syz_csum_ipv4_tcp_packet])
 
 syz_csum_encode {
 	f0	int16
@@ -404,7 +405,24 @@ syz_csum_encode {
 	f5	array[int8, 4]
 } [packed]
 
-syz_csum_ipv4 {
-	f0	csum[ipv4, int16]
-	f1	syz_csum_encode
+syz_csum_ipv4_header {
+	csum		csum[ipv4, int16]
+	data		syz_csum_encode
+	protocol	int8
+	src_ip		int32be
+	dst_ip		int32be
+} [packed]
+
+syz_csum_tcp_header {
+	csum		csum[tcp, int16]
+} [packed]
+
+syz_csum_tcp_packet {
+	header		syz_csum_tcp_header
+	payload		array[int8]
+} [packed]
+
+syz_csum_ipv4_tcp_packet {
+	header		syz_csum_ipv4_header
+	payload		syz_csum_tcp_packet
 } [packed]
diff --git a/sys/vnet.txt b/sys/vnet.txt
index 296d04793..5e9becc70 100644
--- a/sys/vnet.txt
+++ b/sys/vnet.txt
@@ -257,6 +257,139 @@ ipv4_packet {
 	payload		ip_payload
 } [packed]
 
+################################################################################
+###################################### IP ######################################
+################################################################################
+
 ip_payload {
-	dummy		array[int8, 0:128]
+	tcp		tcp_packet
+} [packed]
+
+################################################################################
+###################################### TCP #####################################
+################################################################################
+
+# https://en.wikipedia.org/wiki/Transmission_Control_Protocol#TCP_segment_structure
+# http://www.iana.org/assignments/tcp-parameters/tcp-parameters.xhtml
+
+include <net/tcp.h>
+include <uapi/linux/tcp.h>
+
+tcp_option [
+	generic		tcp_generic_option
+	nop		tcp_nop_option
+	eol		tcp_eol_option
+	mss		tcp_mss_option
+	window		tcp_window_option
+	sack_perm	tcp_sack_perm_option
+	sack		tcp_sack_option
+	timestamp	tcp_timestamp_option
+	md5sig		tcp_md5sig_option
+	fastopen	tcp_fastopen_option
+# TODO: TCPOPT_EXP option
+] [varlen]
+
+tcp_option_types = TCPOPT_NOP, TCPOPT_EOL, TCPOPT_MSS, TCPOPT_WINDOW, TCPOPT_SACK_PERM, TCPOPT_SACK, TCPOPT_TIMESTAMP, TCPOPT_MD5SIG, TCPOPT_FASTOPEN, TCPOPT_EXP
+
+tcp_generic_option {
+	type		flags[tcp_option_types, int8]
+	length		len[parent, int8]
+	data		array[int8, 0:16]
+} [packed]
+
+# https://tools.ietf.org/html/rfc793#section-3.1
+tcp_nop_option {
+	type		const[TCPOPT_NOP, int8]
+} [packed]
+
+# https://tools.ietf.org/html/rfc793#section-3.1
+tcp_eol_option {
+	type		const[TCPOPT_EOL, int8]
+} [packed]
+
+# https://tools.ietf.org/html/rfc793#section-3.1
+tcp_mss_option {
+	type		const[TCPOPT_MSS, int8]
+	length		len[parent, int8]
+	seg_size	int16
+} [packed]
+
+# https://tools.ietf.org/html/rfc7323#section-2
+tcp_window_option {
+	type		const[TCPOPT_WINDOW, int8]
+	length		len[parent, int8]
+	shift		int8
+} [packed]
+
+# https://tools.ietf.org/html/rfc2018#section-2
+tcp_sack_perm_option {
+	type		const[TCPOPT_SACK_PERM, int8]
+	length		len[parent, int8]
+} [packed]
+
+# https://tools.ietf.org/html/rfc2018#section-3
+tcp_sack_option {
+	type		const[TCPOPT_SACK, int8]
+	length		len[parent, int8]
+	data		array[int32be]
+} [packed]
+
+# https://tools.ietf.org/html/rfc7323#section-3
+tcp_timestamp_option {
+	type		const[TCPOPT_TIMESTAMP, int8]
+	length		len[parent, int8]
+	tsval		int32be
+	tsecr		int32be
+} [packed]
+
+# https://tools.ietf.org/html/rfc2385#section-3.0
+tcp_md5sig_option {
+	type		const[TCPOPT_MD5SIG, int8]
+	length		len[parent, int8]
+	md5		array[int8, 16]
+} [packed]
+
+# https://tools.ietf.org/html/rfc7413#section-4.1.1
+tcp_fastopen_option {
+	type		const[TCPOPT_FASTOPEN, int8]
+	length		len[parent, int8]
+	data		array[int8, 0:16]
+} [packed]
+
+tcp_options {
+	options		array[tcp_option]
+} [packed, align_4]
+
+# TODO: extract sequence numbers from packets
+tcp_seq_num [
+	init	const[0x56565656, int32be]
+	next	const[0x56565657, int32be]
+	nextn	int32be[0x56565656:0x56566000]
+	random	int32be
+]
+
+tcp_flags = 0, TCPHDR_FIN, TCPHDR_SYN, TCPHDR_RST, TCPHDR_PSH, TCPHDR_ACK, TCPHDR_URG, TCPHDR_ECE, TCPHDR_CWR, TCPHDR_SYN_ECN
+
+tcp_header {
+	src_port	proc[int16be, 20000, 4]
+	dst_port	proc[int16be, 20000, 4]
+	seq_num		tcp_seq_num
+	ack_num		tcp_seq_num
+	ns		int8:1
+	reserved	const[0, int8:3]
+	data_off	bytesize4[parent, int8:4]
+	flags		flags[tcp_flags, int8]
+	window_size	int16be
+	csum		csum[tcp, int16be]
+	urg_ptr		int16be
+	options		tcp_options
+} [packed]
+
+tcp_packet {
+	header		tcp_header
+	payload		tcp_payload
+} [packed]
+
+tcp_payload {
+	payload		array[int8]
 } [packed]
diff --git a/sys/vnet_amd64.const b/sys/vnet_amd64.const
index cce212a4e..9d9a8855b 100644
--- a/sys/vnet_amd64.const
+++ b/sys/vnet_amd64.const
@@ -101,3 +101,22 @@ IPPROTO_TCP = 6
 IPPROTO_TP = 29
 IPPROTO_UDP = 17
 IPPROTO_UDPLITE = 136
+TCPHDR_ACK = 16
+TCPHDR_CWR = 128
+TCPHDR_ECE = 64
+TCPHDR_FIN = 1
+TCPHDR_PSH = 8
+TCPHDR_RST = 4
+TCPHDR_SYN = 2
+TCPHDR_SYN_ECN = 194
+TCPHDR_URG = 32
+TCPOPT_EOL = 0
+TCPOPT_EXP = 254
+TCPOPT_FASTOPEN = 34
+TCPOPT_MD5SIG = 19
+TCPOPT_MSS = 2
+TCPOPT_NOP = 1
+TCPOPT_SACK = 5
+TCPOPT_SACK_PERM = 4
+TCPOPT_TIMESTAMP = 8
+TCPOPT_WINDOW = 3
diff --git a/sys/vnet_arm64.const b/sys/vnet_arm64.const
index cce212a4e..9d9a8855b 100644
--- a/sys/vnet_arm64.const
+++ b/sys/vnet_arm64.const
@@ -101,3 +101,22 @@ IPPROTO_TCP = 6
 IPPROTO_TP = 29
 IPPROTO_UDP = 17
 IPPROTO_UDPLITE = 136
+TCPHDR_ACK = 16
+TCPHDR_CWR = 128
+TCPHDR_ECE = 64
+TCPHDR_FIN = 1
+TCPHDR_PSH = 8
+TCPHDR_RST = 4
+TCPHDR_SYN = 2
+TCPHDR_SYN_ECN = 194
+TCPHDR_URG = 32
+TCPOPT_EOL = 0
+TCPOPT_EXP = 254
+TCPOPT_FASTOPEN = 34
+TCPOPT_MD5SIG = 19
+TCPOPT_MSS = 2
+TCPOPT_NOP = 1
+TCPOPT_SACK = 5
+TCPOPT_SACK_PERM = 4
+TCPOPT_TIMESTAMP = 8
+TCPOPT_WINDOW = 3
diff --git a/sys/vnet_ppc64le.const b/sys/vnet_ppc64le.const
index cce212a4e..9d9a8855b 100644
--- a/sys/vnet_ppc64le.const
+++ b/sys/vnet_ppc64le.const
@@ -101,3 +101,22 @@ IPPROTO_TCP = 6
 IPPROTO_TP = 29
 IPPROTO_UDP = 17
 IPPROTO_UDPLITE = 136
+TCPHDR_ACK = 16
+TCPHDR_CWR = 128
+TCPHDR_ECE = 64
+TCPHDR_FIN = 1
+TCPHDR_PSH = 8
+TCPHDR_RST = 4
+TCPHDR_SYN = 2
+TCPHDR_SYN_ECN = 194
+TCPHDR_URG = 32
+TCPOPT_EOL = 0
+TCPOPT_EXP = 254
+TCPOPT_FASTOPEN = 34
+TCPOPT_MD5SIG = 19
+TCPOPT_MSS = 2
+TCPOPT_NOP = 1
+TCPOPT_SACK = 5
+TCPOPT_SACK_PERM = 4
+TCPOPT_TIMESTAMP = 8
+TCPOPT_WINDOW = 3