[PATCH 3/6] net: introduce TCP/IP6 support

8 May 2023

Add TCP/IP6 related headers and reuse refactored TCP/IP
implementation
Signed-off-by: Dmitrii Merkurev dimorinny@google.com
Cc: Ying-Chun Liu (PaulLiu) paul.liu@linaro.org
Cc: Simon Glass sjg@chromium.org
Сс: Joe Hershberger joe.hershberger@ni.com
Сс: Ramon Fried rfried.dev@gmail.com
---
 include/net/tcp6.h | 103 +++++++++++++++++++++++++++++++++++++++++++++
 include/net6.h     |  14 ++++++
 net/Makefile       |   1 +
 net/net.c          |   6 +++
 net/net6.c         |  43 ++++++++++++++++++-
 net/tcp6.c         |  95 +++++++++++++++++++++++++++++++++++++++++
 6 files changed, 260 insertions(+), 2 deletions(-)
 create mode 100644 include/net/tcp6.h
 create mode 100644 net/tcp6.c

diff --git a/include/net/tcp6.h b/include/net/tcp6.h
new file mode 100644
index 0000000000..102f5a240a
--- /dev/null
+++ b/include/net/tcp6.h
@@ -0,0 +1,103 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ */
+
+#ifndef __TCP6_H__
+#define __TCP6_H__
+
+#include <net6.h>
+#include <net/tcp.h>
+
+/**
+ * typedef rxhand_tcp6_f() - An incoming TCP IPv6 packet handler.
+ * @pkt: pointer to the application packet
+ * @dport: destination TCP port
+ * @sip: source IP6 address
+ * @sport: source TCP port
+ * @tcp_seq_num: TCP sequential number
+ * @tcp_ack_num: TCP acknowledgment number
+ * @action: TCP packet type (SYN, ACK, FIN, etc)
+ */
+typedef void rxhand_tcp6_f(uchar *pkt, u16 dport,
+			   struct in6_addr sip, u16 sport,
+			   u32 tcp_seq_num, u32 tcp_ack_num,
+			   u8 action, unsigned int len);
+
+/**
+ * struct ip6_tcp_hdr_o - IP6 + TCP header + TCP options
+ * @ip_hdr: IP6 + TCP header
+ * @tcp_hdr: TCP header
+ * @tcp_o: TCP options
+ * @end: end of IP6/TCP header
+ */
+struct ip6_tcp_hdr_o {
+	struct  ip6_hdr    ip_hdr;
+	struct  tcp_hdr    tcp_hdr;
+	struct  tcp_hdr_o  tcp_o;
+	u8	end;
+} __packed;
+
+#define IP6_TCP_O_SIZE (sizeof(struct ip6_tcp_hdr_o))
+
+/**
+ * struct ip6_tcp_hdr_s - IP6 + TCP header + TCP options
+ * @ip_hdr: IP6 + TCP header
+ * @tcp_hdr: TCP header
+ * @t_opt: TCP Timestamp Option
+ * @sack_v: TCP SACK Option
+ * @end: end of options
+ */
+struct ip6_tcp_hdr_s {
+	struct  ip6_hdr    ip_hdr;
+	struct  tcp_hdr    tcp_hdr;
+	struct  tcp_t_opt  t_opt;
+	struct  tcp_sack_v sack_v;
+	u8	end;
+} __packed;
+
+#define IP6_TCP_SACK_SIZE (sizeof(struct ip6_tcp_hdr_s))
+
+/**
+ * union tcp6_build_pkt - union for building TCP/IP6 packet.
+ * @ip: IP6 and TCP header plus TCP options
+ * @sack: IP6 and TCP header plus SACK options
+ * @raw: buffer
+ */
+union tcp6_build_pkt {
+	struct ip6_tcp_hdr_o ip;
+	struct ip6_tcp_hdr_s sack;
+	uchar  raw[1600];
+} __packed;
+
+/**
+ * net_set_tcp6_handler6() - set application TCP6 packet handler
+ * @param f pointer to callback function
+ */
+void net_set_tcp_handler6(rxhand_tcp6_f *f);
+
+/**
+ * net_set_tcp_header6() - set
+ * @pkt: pointer to IP6/TCP headers
+ * @dport: destination TCP port
+ * @sport: source TCP port
+ * @payload_len: payload length
+ * @action: TCP packet type (SYN, ACK, FIN, etc)
+ * @tcp_seq_num: TCP sequential number
+ * @tcp_ack_num: TCP acknowledgment number
+ *
+ * returns TCP header size
+ */
+int net_set_tcp_header6(uchar *pkt, u16 dport, u16 sport, int payload_len,
+			u8 action, u32 tcp_seq_num, u32 tcp_ack_num);
+
+void net_set_tcp_handler6(rxhand_tcp6_f *f);
+
+/**
+ * rxhand_tcp6() - handle incoming IP6 TCP packet
+ * @param b pointer to IP6/TCP packet builder struct
+ * @param len full packet length
+ */
+void rxhand_tcp6(union tcp6_build_pkt *b, unsigned int len);
+
+#endif // __TCP6_H__
diff --git a/include/net6.h b/include/net6.h
index beafc05338..fa926f07ac 100644
--- a/include/net6.h
+++ b/include/net6.h
@@ -344,6 +344,20 @@ int ip6_add_hdr(uchar *xip, struct in6_addr *src, struct in6_addr *dest,
 int net_send_udp_packet6(uchar *ether, struct in6_addr *dest, int dport,
    		 int sport, int len);
+/**
+ * net_send_tcp_packet6() - Make up TCP packet and send it
+ *
+ * @payload_len: TCP payload length
+ * @dport:	 destination port
+ * @sport:	 source port
+ * @action:	 TCP flag (SYN, ACL, PUSH, etc)
+ * @tcp_seq_num: TCP sequence number
+ * @tcp_ack_num: TCP ackno
+ * Return: 0 if send successfully, -1 otherwise
+ */
+int net_send_tcp_packet6(int payload_len, int dport, int sport, u8 action,
+			 u32 tcp_seq_num, u32 tcp_ack_num);
+
 /**
  * net_ip6_handler() - Handle IPv6 packet
  *
diff --git a/net/Makefile b/net/Makefile
index 3e2d061338..002b0f68a2 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_TCP_FUNCTION_FASTBOOT)  += fastboot_tcp.o
 obj-$(CONFIG_CMD_WOL)  += wol.o
 obj-$(CONFIG_PROT_UDP) += udp.o
 obj-$(CONFIG_PROT_TCP) += tcp.o
+obj-$(CONFIG_IPV6) += tcp6.o
 obj-$(CONFIG_CMD_WGET) += wget.o
# Disable this warning as it is triggered by:
diff --git a/net/net.c b/net/net.c
index 0b68bf7b13..3fc6681898 100644
--- a/net/net.c
+++ b/net/net.c
@@ -92,6 +92,7 @@
 #include <log.h>
 #include <net.h>
 #include <net6.h>
+#include <net/tcp6.h>
 #include <ndisc.h>
 #include <net/fastboot_udp.h>
 #include <net/fastboot_tcp.h>
@@ -386,6 +387,9 @@ static void net_clear_handlers(void)
    net_set_udp_handler(NULL);
    net_set_arp_handler(NULL);
    net_set_timeout_handler(0, NULL);
+#if defined(CONFIG_IPV6)
+	net_set_tcp_handler6(NULL);
+#endif
 }
static void net_cleanup_loop(void)
@@ -916,7 +920,9 @@ int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
 {
    uchar *pkt;
    int eth_hdr_size;
+#if defined(CONFIG_PROT_TCP)
    int ip_tcp_hdr_size;
+#endif
    int pkt_hdr_size;
/* make sure the net_tx_packet is initialized (net_init() was called) */
diff --git a/net/net6.c b/net/net6.c
index e395b930b0..6418611403 100644
--- a/net/net6.c
+++ b/net/net6.c
@@ -14,6 +14,7 @@
 #include <malloc.h>
 #include <net.h>
 #include <net6.h>
+#include <net/tcp6.h>
 #include <ndisc.h>
/* NULL IPv6 address */
@@ -362,8 +363,8 @@ int net_send_ip_packet6(uchar *ether, struct in6_addr *dest, int dport, int spor
    pkt = (uchar *)net_tx_packet;
eth_hdr_size = net_set_ether(pkt, ether, PROT_IP6);
-	pkt_hdr_size += eth_hdr_size;
-	pkt = eth_hdr_size;
+	pkt_hdr_size = eth_hdr_size;
+	pkt += eth_hdr_size;
switch (proto) {
 #if defined(CONFIG_PROT_UDP)
@@ -377,6 +378,18 @@ int net_send_ip_packet6(uchar *ether, struct in6_addr *dest, int dport, int spor
    	pkt_hdr_size += udp_hdr_size;
    	pkt += udp_hdr_size;
    	break;
+#endif
+#if defined(CONFIG_PROT_TCP)
+	case IPPROTO_TCP:
+		tcp_hdr_size = net_set_tcp_header6(pkt, dport, sport,
+						   payload_len, action, tcp_seq_num,
+						   tcp_ack_num);
+		ip_hdr_size = ip6_add_hdr(pkt, &net_ip6, dest, IPPROTO_TCP, 64,
+					  tcp_hdr_size + payload_len);
+
+		pkt_hdr_size += ip_hdr_size + tcp_hdr_size;
+		pkt += ip_hdr_size + tcp_hdr_size;
+		break;
 #endif
    default:
    	return -EINVAL;
@@ -411,11 +424,21 @@ int net_send_udp_packet6(uchar *ether, struct in6_addr *dest, int dport,
    return net_send_ip_packet6(ether, dest, dport, sport, len, IPPROTO_UDP, 0, 0, 0);
 }
+int net_send_tcp_packet6(int payload_len, int dport, int sport, u8 action,
+			 u32 tcp_seq_num, u32 tcp_ack_num)
+{
+	return net_send_ip_packet6(net_server_ethaddr, &net_server_ip6, dport,
+				   sport, payload_len, IPPROTO_TCP, action,
+				   tcp_seq_num, tcp_ack_num);
+}
+
 int net_ip6_handler(struct ethernet_hdr *et, struct ip6_hdr *ip6, int len)
 {
+	union tcp6_build_pkt *tcp_headers;
    struct in_addr zero_ip = {.s_addr = 0 };
    struct icmp6hdr *icmp;
    struct udp_hdr *udp;
+	struct tcp_hdr *tcp;
    u16 csum;
    u16 csum_p;
    u16 hlen;
@@ -475,6 +498,22 @@ int net_ip6_handler(struct ethernet_hdr *et, struct ip6_hdr *ip6, int len)
    			ntohs(udp->udp_src),
    			ntohs(udp->udp_len) - 8);
    	break;
+	case IPPROTO_TCP:
+		tcp = (struct tcp_hdr *)(((uchar *)ip6) + IP6_HDR_SIZE);
+		csum = tcp->tcp_xsum;
+		hlen = ntohs(ip6->payload_len);
+		tcp->tcp_xsum = 0;
+		/* checksum */
+		csum_p = csum_partial((u8 *)tcp, hlen, 0);
+		tcp->tcp_xsum = csum_ipv6_magic(&ip6->saddr, &ip6->daddr,
+						hlen, IPPROTO_TCP, csum_p);
+
+		if (csum != tcp->tcp_xsum)
+			return -EINVAL;
+
+		tcp_headers = (union tcp6_build_pkt *)ip6;
+		rxhand_tcp6(tcp_headers, len);
+		break;
    default:
    	return -EINVAL;
    }
diff --git a/net/tcp6.c b/net/tcp6.c
new file mode 100644
index 0000000000..9add8cddab
--- /dev/null
+++ b/net/tcp6.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ */
+
+#include <common.h>
+#include <net/tcp.h>
+#include <net/tcp6.h>
+#include <net6.h>
+
+static rxhand_tcp6_f *tcp6_packet_handler;
+
+static void dummy_handler(uchar *pkt, u16 dport,
+			  struct in6_addr sip, u16 sport,
+			  u32 tcp_seq_num, u32 tcp_ack_num,
+			  u8 action, unsigned int len)
+{
+}
+
+void net_set_tcp_handler6(rxhand_tcp6_f *f)
+{
+	if (!f)
+		tcp6_packet_handler = dummy_handler;
+	else
+		tcp6_packet_handler = f;
+}
+
+int net_set_tcp_header6(uchar *pkt, u16 dport, u16 sport, int payload_len,
+			u8 action, u32 tcp_seq_num, u32 tcp_ack_num)
+{
+	union tcp6_build_pkt *b = (union tcp6_build_pkt *)pkt;
+	int tcp_hdr_len;
+	int pkt_len;
+	u16 csum;
+
+	pkt_len = IP6_HDR_SIZE;
+	tcp_hdr_len = net_set_tcp_header_common(&b->ip.tcp_hdr, &b->ip.tcp_o,
+						&b->sack.t_opt, &b->sack.sack_v,
+						dport, sport, payload_len, action,
+						tcp_seq_num, tcp_ack_num);
+	pkt_len += tcp_hdr_len;
+	pkt_len += payload_len;
+
+	csum = csum_partial((u8 *)&b->ip.tcp_hdr, tcp_hdr_len + payload_len, 0);
+	b->ip.tcp_hdr.tcp_xsum = csum_ipv6_magic(&net_ip6, &net_server_ip6,
+						 tcp_hdr_len + payload_len,
+						 IPPROTO_TCP, csum);
+
+	return tcp_hdr_len;
+}
+
+void rxhand_tcp6(union tcp6_build_pkt *b, unsigned int len)
+{
+	int tcp_len = len - IP6_HDR_SIZE;
+	u8  tcp_action = TCP_DATA;
+	u32 tcp_seq_num, tcp_ack_num;
+	u32 res_tcp_seq_num, res_tcp_ack_num;
+	int tcp_hdr_len, payload_len;
+
+	net_copy_ip6(&net_server_ip6, &b->ip.ip_hdr.saddr);
+
+	tcp_hdr_len = GET_TCP_HDR_LEN_IN_BYTES(b->ip.tcp_hdr.tcp_hlen);
+	payload_len = tcp_len - tcp_hdr_len;
+
+	if (tcp_hdr_len > TCP_HDR_SIZE)
+		tcp_parse_options((uchar *)b + IP6_HDR_SIZE + TCP_HDR_SIZE,
+				  tcp_hdr_len - TCP_HDR_SIZE);
+
+	tcp_seq_num = ntohl(b->ip.tcp_hdr.tcp_seq);
+	tcp_ack_num = ntohl(b->ip.tcp_hdr.tcp_ack);
+
+	tcp_action = tcp_state_machine(b->ip.tcp_hdr.tcp_flags,
+				       tcp_seq_num, &res_tcp_seq_num, &res_tcp_ack_num,
+				       payload_len);
+
+	if ((tcp_action & TCP_PUSH) || payload_len > 0) {
+		debug_cond(DEBUG_DEV_PKT,
+			   "TCP Notify (action=%x, Seq=%u,Ack=%u,Pay%d)\n",
+			   tcp_action, tcp_seq_num, tcp_ack_num, payload_len);
+
+		(*tcp6_packet_handler) ((uchar *)b + len - payload_len, b->ip.tcp_hdr.tcp_dst,
+					b->ip.ip_hdr.saddr, b->ip.tcp_hdr.tcp_src, tcp_seq_num,
+					tcp_ack_num, tcp_action, payload_len);
+
+	} else if (tcp_action != TCP_DATA) {
+		debug_cond(DEBUG_DEV_PKT,
+			   "TCP Action (action=%x,Seq=%u,Ack=%u,Pay=%d)\n",
+			   tcp_action, res_tcp_seq_num, res_tcp_ack_num, payload_len);
+
+		net_send_tcp_packet6(0, ntohs(b->ip.tcp_hdr.tcp_src),
+				     ntohs(b->ip.tcp_hdr.tcp_dst),
+				     (tcp_action & (~TCP_PUSH)),
+				     res_tcp_seq_num, res_tcp_ack_num);
+	}
+}
-- 
2.40.1.521.gf1e218fcd8-goog


    