net/tcp: add connection info to tcp_stream structure

Changes:
 * Avoid use net_server_ip in tcp code, use tcp_stream data instead
 * Ignore packets from other connections if connection already created.
   This prevents us from connection break caused by other tcp stream.

Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevetskiy@iopsys.eu>
Reviewed-by: Simon Glass <sjg@chromium.org>

Author: mkshevetskiy

include/net-legacy.h

@@ -416,6 +416,7 @@ int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
 /**
  * net_send_tcp_packet() - Transmit TCP packet.
  * @payload_len: length of payload
+ * @dhost: Destination host
  * @dport: Destination TCP port
  * @sport: Source TCP port
  * @action: TCP action to be performed
@@ -424,8 +425,8 @@ int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
  *
  * Return: 0 on success, other value on failure
  */
-int net_send_tcp_packet(int payload_len, int dport, int sport, u8 action,
-			u32 tcp_seq_num, u32 tcp_ack_num);
+int net_send_tcp_packet(int payload_len, struct in_addr dhost, int dport,
+			int sport, u8 action, u32 tcp_seq_num, u32 tcp_ack_num);
 int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport,
 			int sport, int payload_len);
 

include/net/tcp.h

@@ -279,6 +279,9 @@ enum tcp_state {
 
 /**
  * struct tcp_stream - TCP data stream structure
+ * @rhost:		Remote host, network byte order
+ * @rport:		Remote port, host byte order
+ * @lport:		Local port, host byte order
  *
  * @state:		TCP connection state
  *
@@ -291,6 +294,10 @@ enum tcp_state {
  * @lost:		Used for SACK
  */
 struct tcp_stream {
+	struct in_addr	rhost;
+	u16		rport;
+	u16		lport;
+
 	/* TCP connection state */
 	enum tcp_state	state;
 
@@ -305,16 +312,53 @@ struct tcp_stream {
 	struct tcp_sack_v lost;
 };
 
-struct tcp_stream *tcp_stream_get(void);
+void tcp_init(void);
+
+typedef int tcp_incoming_filter(struct in_addr rhost,
+				u16 rport, u16 sport);
+
+/*
+ * This function sets user callback used to accept/drop incoming
+ * connections. Callback should:
+ *  + Check TCP stream endpoint and make connection verdict
+ *    - return non-zero value to accept connection
+ *    - return zero to drop connection
+ *
+ * WARNING: If callback is NOT defined, all incoming connections
+ *          will be dropped.
+ */
+void tcp_set_incoming_filter(tcp_incoming_filter *filter);
+
+/*
+ * tcp_stream_get -- Get or create TCP stream
+ * @is_new:	if non-zero and no stream found, then create a new one
+ * @rhost:	Remote host, network byte order
+ * @rport:	Remote port, host byte order
+ * @lport:	Local port, host byte order
+ *
+ * Returns: TCP stream structure or NULL (if not found/created)
+ */
+struct tcp_stream *tcp_stream_get(int is_new, struct in_addr rhost,
+				  u16 rport, u16 lport);
+
+/*
+ * tcp_stream_connect -- Create new TCP stream for remote connection.
+ * @rhost:	Remote host, network byte order
+ * @rport:	Remote port, host byte order
+ *
+ * Returns: TCP new stream structure or NULL (if not created).
+ *          Random local port will be used.
+ */
+struct tcp_stream *tcp_stream_connect(struct in_addr rhost, u16 rport);
+
+enum tcp_state tcp_stream_get_state(struct tcp_stream *tcp);
 
-enum tcp_state tcp_get_tcp_state(struct tcp_stream *tcp);
-void tcp_set_tcp_state(struct tcp_stream *tcp, enum tcp_state new_state);
-int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
-		       int sport, int payload_len,
+int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int payload_len,
 		       u8 action, u32 tcp_seq_num, u32 tcp_ack_num);
 
 /**
  * rxhand_tcp() - An incoming packet handler.
+ * @tcp: TCP stream
  * @pkt: pointer to the application packet
  * @dport: destination TCP port
  * @sip: source IP address
@@ -324,8 +368,7 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
  * @action: TCP action (SYN, ACK, FIN, etc)
  * @len: packet length
  */
-typedef void rxhand_tcp(uchar *pkt, u16 dport,
-			struct in_addr sip, u16 sport,
+typedef void rxhand_tcp(struct tcp_stream *tcp, uchar *pkt,
 			u32 tcp_seq_num, u32 tcp_ack_num,
 			u8 action, unsigned int len);
 void tcp_set_tcp_handler(rxhand_tcp *f);

net/fastboot_tcp.c

@@ -8,14 +8,14 @@
 #include <net/fastboot_tcp.h>
 #include <net/tcp.h>
 
-static char command[FASTBOOT_COMMAND_LEN] = {0};
-static char response[FASTBOOT_RESPONSE_LEN] = {0};
+#define FASTBOOT_TCP_PORT	5554
+
+static char command[FASTBOOT_COMMAND_LEN];
+static char response[FASTBOOT_RESPONSE_LEN];
 
 static const unsigned short handshake_length = 4;
 static const uchar *handshake = "FB01";
 
-static u16 curr_sport;
-static u16 curr_dport;
 static u32 curr_tcp_seq_num;
 static u32 curr_tcp_ack_num;
 static unsigned int curr_request_len;
@@ -25,34 +25,37 @@ static enum fastboot_tcp_state {
 	FASTBOOT_DISCONNECTING
 } state = FASTBOOT_CLOSED;
 
-static void fastboot_tcp_answer(u8 action, unsigned int len)
+static void fastboot_tcp_answer(struct tcp_stream *tcp, u8 action,
+				unsigned int len)
 {
 	const u32 response_seq_num = curr_tcp_ack_num;
 	const u32 response_ack_num = curr_tcp_seq_num +
 		  (curr_request_len > 0 ? curr_request_len : 1);
 
-	net_send_tcp_packet(len, htons(curr_sport), htons(curr_dport),
+	net_send_tcp_packet(len, tcp->rhost, tcp->rport, tcp->lport,
 			    action, response_seq_num, response_ack_num);
 }
 
-static void fastboot_tcp_reset(void)
+static void fastboot_tcp_reset(struct tcp_stream *tcp)
 {
-	fastboot_tcp_answer(TCP_RST, 0);
+	fastboot_tcp_answer(tcp, TCP_RST, 0);
 	state = FASTBOOT_CLOSED;
 }
 
-static void fastboot_tcp_send_packet(u8 action, const uchar *data, unsigned int len)
+static void fastboot_tcp_send_packet(struct tcp_stream *tcp, u8 action,
+				     const uchar *data, unsigned int len)
 {
 	uchar *pkt = net_get_async_tx_pkt_buf();
 
 	memset(pkt, '\0', PKTSIZE);
 	pkt += net_eth_hdr_size() + IP_TCP_HDR_SIZE + TCP_TSOPT_SIZE + 2;
 	memcpy(pkt, data, len);
-	fastboot_tcp_answer(action, len);
+	fastboot_tcp_answer(tcp, action, len);
 	memset(pkt, '\0', PKTSIZE);
 }
 
-static void fastboot_tcp_send_message(const char *message, unsigned int len)
+static void fastboot_tcp_send_message(struct tcp_stream *tcp,
+				      const char *message, unsigned int len)
 {
 	__be64 len_be = __cpu_to_be64(len);
 	uchar *pkt = net_get_async_tx_pkt_buf();
@@ -63,12 +66,11 @@ static void fastboot_tcp_send_message(const char *message, unsigned int len)
 	memcpy(pkt, &len_be, 8);
 	pkt += 8;
 	memcpy(pkt, message, len);
-	fastboot_tcp_answer(TCP_ACK | TCP_PUSH, len + 8);
+	fastboot_tcp_answer(tcp, TCP_ACK | TCP_PUSH, len + 8);
 	memset(pkt, '\0', PKTSIZE);
 }
 
-static void fastboot_tcp_handler_ipv4(uchar *pkt, u16 dport,
-				      struct in_addr sip, u16 sport,
+static void fastboot_tcp_handler_ipv4(struct tcp_stream *tcp, uchar *pkt,
 				      u32 tcp_seq_num, u32 tcp_ack_num,
 				      u8 action, unsigned int len)
 {
@@ -77,8 +79,6 @@ static void fastboot_tcp_handler_ipv4(uchar *pkt, u16 dport,
 	u8 tcp_fin = action & TCP_FIN;
 	u8 tcp_push = action & TCP_PUSH;
 
-	curr_sport = sport;
-	curr_dport = dport;
 	curr_tcp_seq_num = tcp_seq_num;
 	curr_tcp_ack_num = tcp_ack_num;
 	curr_request_len = len;
@@ -89,17 +89,17 @@ static void fastboot_tcp_handler_ipv4(uchar *pkt, u16 dport,
 			if (len != handshake_length ||
 			    strlen(pkt) != handshake_length ||
 			    memcmp(pkt, handshake, handshake_length) != 0) {
-				fastboot_tcp_reset();
+				fastboot_tcp_reset(tcp);
 				break;
 			}
-			fastboot_tcp_send_packet(TCP_ACK | TCP_PUSH,
+			fastboot_tcp_send_packet(tcp, TCP_ACK | TCP_PUSH,
 						 handshake, handshake_length);
 			state = FASTBOOT_CONNECTED;
 		}
 		break;
 	case FASTBOOT_CONNECTED:
 		if (tcp_fin) {
-			fastboot_tcp_answer(TCP_FIN | TCP_ACK, 0);
+			fastboot_tcp_answer(tcp, TCP_FIN | TCP_ACK, 0);
 			state = FASTBOOT_DISCONNECTING;
 			break;
 		}
@@ -111,12 +111,12 @@ static void fastboot_tcp_handler_ipv4(uchar *pkt, u16 dport,
 
 			// Only single packet messages are supported ATM
 			if (strlen(pkt) != command_size) {
-				fastboot_tcp_reset();
+				fastboot_tcp_reset(tcp);
 				break;
 			}
 			strlcpy(command, pkt, len + 1);
 			fastboot_command_id = fastboot_handle_command(command, response);
-			fastboot_tcp_send_message(response, strlen(response));
+			fastboot_tcp_send_message(tcp, response, strlen(response));
 			fastboot_handle_boot(fastboot_command_id,
 					     strncmp("OKAY", response, 4) == 0);
 		}
@@ -129,17 +129,21 @@ static void fastboot_tcp_handler_ipv4(uchar *pkt, u16 dport,
 
 	memset(command, 0, FASTBOOT_COMMAND_LEN);
 	memset(response, 0, FASTBOOT_RESPONSE_LEN);
-	curr_sport = 0;
-	curr_dport = 0;
 	curr_tcp_seq_num = 0;
 	curr_tcp_ack_num = 0;
 	curr_request_len = 0;
 }
 
+static int incoming_filter(struct in_addr rhost, u16 rport, u16 lport)
+{
+	return (lport == FASTBOOT_TCP_PORT);
+}
+
 void fastboot_tcp_start_server(void)
 {
 	printf("Using %s device\n", eth_get_name());
 	printf("Listening for fastboot command on tcp %pI4\n", &net_ip);
 
+	tcp_set_incoming_filter(incoming_filter);
 	tcp_set_tcp_handler(fastboot_tcp_handler_ipv4);
 }

net/net.c

@@ -420,7 +420,7 @@ int net_init(void)
 		/* Only need to setup buffer pointers once. */
 		first_call = 0;
 		if (IS_ENABLED(CONFIG_PROT_TCP))
-			tcp_set_tcp_state(tcp_stream_get(), TCP_CLOSED);
+			tcp_init();
 	}
 
 	return net_init_loop();
@@ -908,10 +908,10 @@ int net_send_udp_packet(uchar *ether, struct in_addr dest, int dport, int sport,
 }
 
 #if defined(CONFIG_PROT_TCP)
-int net_send_tcp_packet(int payload_len, int dport, int sport, u8 action,
-			u32 tcp_seq_num, u32 tcp_ack_num)
+int net_send_tcp_packet(int payload_len, struct in_addr dhost, int dport,
+			int sport, u8 action, u32 tcp_seq_num, u32 tcp_ack_num)
 {
-	return net_send_ip_packet(net_server_ethaddr, net_server_ip, dport,
+	return net_send_ip_packet(net_server_ethaddr, dhost, dport,
 				  sport, payload_len, IPPROTO_TCP, action,
 				  tcp_seq_num, tcp_ack_num);
 }
@@ -953,12 +953,12 @@ int net_send_ip_packet(uchar *ether, struct in_addr dest, int dport, int sport,
 		break;
 #if defined(CONFIG_PROT_TCP)
 	case IPPROTO_TCP:
-		tcp = tcp_stream_get();
+		tcp = tcp_stream_get(0, dest, dport, sport);
 		if (!tcp)
 			return -EINVAL;
 
 		pkt_hdr_size = eth_hdr_size
-			+ tcp_set_tcp_header(tcp, pkt + eth_hdr_size, dport, sport,
+			+ tcp_set_tcp_header(tcp, pkt + eth_hdr_size,
 					     payload_len, action, tcp_seq_num,
 					     tcp_ack_num);
 		break;