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>

1 files changed, 99 insertions, 30 deletions

diff --git a/net/tcp.c b/net/tcp.c
index 8eeb43b8796..db708f0a2a5 100644
--- a/net/tcp.c
+++ b/net/tcp.c
@@ -26,6 +26,7 @@
 
 static int tcp_activity_count;
 static struct tcp_stream tcp_stream;
+static tcp_incoming_filter *incoming_filter;
 
 /*
  * TCP lengths are stored as a rounded up number of 32 bit words.
@@ -40,40 +41,95 @@ static struct tcp_stream tcp_stream;
 /* Current TCP RX packet handler */
 static rxhand_tcp *tcp_packet_handler;
 
+#define RANDOM_PORT_START 1024
+#define RANDOM_PORT_RANGE 0x4000
+
+/**
+ * random_port() - make port a little random (1024-17407)
+ *
+ * Return: random port number from 1024 to 17407
+ *
+ * This keeps the math somewhat trivial to compute, and seems to work with
+ * all supported protocols/clients/servers
+ */
+static uint random_port(void)
+{
+	return RANDOM_PORT_START + (get_timer(0) % RANDOM_PORT_RANGE);
+}
+
 static inline s32 tcp_seq_cmp(u32 a, u32 b)
 {
 	return (s32)(a - b);
 }
 
 /**
- * tcp_get_tcp_state() - get TCP stream state
+ * tcp_stream_get_state() - get TCP stream state
  * @tcp: tcp stream
  *
  * Return: TCP stream state
  */
-enum tcp_state tcp_get_tcp_state(struct tcp_stream *tcp)
+enum tcp_state tcp_stream_get_state(struct tcp_stream *tcp)
 {
 	return tcp->state;
 }
 
 /**
- * tcp_set_tcp_state() - set TCP stream state
+ * tcp_stream_set_state() - set TCP stream state
  * @tcp: tcp stream
  * @new_state: new TCP state
  */
-void tcp_set_tcp_state(struct tcp_stream *tcp,
-		       enum tcp_state new_state)
+static void tcp_stream_set_state(struct tcp_stream *tcp,
+				 enum tcp_state new_state)
 {
 	tcp->state = new_state;
 }
 
-struct tcp_stream *tcp_stream_get(void)
+void tcp_init(void)
+{
+	incoming_filter = NULL;
+	tcp_stream.state = TCP_CLOSED;
+}
+
+void tcp_set_incoming_filter(tcp_incoming_filter *filter)
+{
+	incoming_filter = filter;
+}
+
+static struct tcp_stream *tcp_stream_add(struct in_addr rhost,
+					 u16 rport, u16 lport)
+{
+	struct tcp_stream *tcp = &tcp_stream;
+
+	if (tcp->state != TCP_CLOSED)
+		return NULL;
+
+	memset(tcp, 0, sizeof(struct tcp_stream));
+	tcp->rhost.s_addr = rhost.s_addr;
+	tcp->rport = rport;
+	tcp->lport = lport;
+	tcp->state = TCP_CLOSED;
+	tcp->lost.len = TCP_OPT_LEN_2;
+	return tcp;
+}
+
+struct tcp_stream *tcp_stream_get(int is_new, struct in_addr rhost,
+				  u16 rport, u16 lport)
 {
-	return &tcp_stream;
+	struct tcp_stream *tcp = &tcp_stream;
+
+	if (tcp->rhost.s_addr == rhost.s_addr &&
+	    tcp->rport == rport &&
+	    tcp->lport == lport)
+		return tcp;
+
+	if (!is_new || !incoming_filter ||
+	    !incoming_filter(rhost, rport, lport))
+		return NULL;
+
+	return tcp_stream_add(rhost, rport, lport);
 }
 
-static void dummy_handler(uchar *pkt, u16 dport,
-			  struct in_addr sip, u16 sport,
+static void dummy_handler(struct tcp_stream *tcp, uchar *pkt,
 			  u32 tcp_seq_num, u32 tcp_ack_num,
 			  u8 action, unsigned int len)
 {
@@ -222,8 +278,7 @@ void net_set_syn_options(struct tcp_stream *tcp, union tcp_build_pkt *b)
 	b->ip.end = TCP_O_END;
 }
 
-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)
 {
 	union tcp_build_pkt *b = (union tcp_build_pkt *)pkt;
@@ -243,7 +298,7 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 	case TCP_SYN:
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP Hdr:SYN (%pI4, %pI4, sq=%u, ak=%u)\n",
-			   &net_server_ip, &net_ip,
+			   &tcp->rhost, &net_ip,
 			   tcp_seq_num, tcp_ack_num);
 		tcp_activity_count = 0;
 		net_set_syn_options(tcp, b);
@@ -264,13 +319,13 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 		b->ip.hdr.tcp_flags = action;
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP Hdr:ACK (%pI4, %pI4, s=%u, a=%u, A=%x)\n",
-			   &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num,
+			   &tcp->rhost, &net_ip, tcp_seq_num, tcp_ack_num,
 			   action);
 		break;
 	case TCP_FIN:
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP Hdr:FIN  (%pI4, %pI4, s=%u, a=%u)\n",
-			   &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num);
+			   &tcp->rhost, &net_ip, tcp_seq_num, tcp_ack_num);
 		payload_len = 0;
 		pkt_hdr_len = IP_TCP_HDR_SIZE;
 		tcp->state = TCP_FIN_WAIT_1;
@@ -279,7 +334,7 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 	case TCP_RST:
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP Hdr:RST  (%pI4, %pI4, s=%u, a=%u)\n",
-			   &net_server_ip, &net_ip, tcp_seq_num, tcp_ack_num);
+			   &tcp->rhost, &net_ip, tcp_seq_num, tcp_ack_num);
 		tcp->state = TCP_CLOSED;
 		break;
 	/* Notify connection closing */
@@ -290,7 +345,7 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP Hdr:FIN ACK PSH(%pI4, %pI4, s=%u, a=%u, A=%x)\n",
-			   &net_server_ip, &net_ip,
+			   &tcp->rhost, &net_ip,
 			   tcp_seq_num, tcp_ack_num, action);
 		fallthrough;
 	default:
@@ -298,7 +353,7 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 		b->ip.hdr.tcp_flags = action | TCP_PUSH | TCP_ACK;
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP Hdr:dft  (%pI4, %pI4, s=%u, a=%u, A=%x)\n",
-			   &net_server_ip, &net_ip,
+			   &tcp->rhost, &net_ip,
 			   tcp_seq_num, tcp_ack_num, action);
 	}
 
@@ -308,8 +363,8 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 	tcp->ack_edge = tcp_ack_num;
 	/* TCP Header */
 	b->ip.hdr.tcp_ack = htonl(tcp->ack_edge);
-	b->ip.hdr.tcp_src = htons(sport);
-	b->ip.hdr.tcp_dst = htons(dport);
+	b->ip.hdr.tcp_src = htons(tcp->lport);
+	b->ip.hdr.tcp_dst = htons(tcp->rport);
 	b->ip.hdr.tcp_seq = htonl(tcp_seq_num);
 
 	/*
@@ -332,10 +387,10 @@ int tcp_set_tcp_header(struct tcp_stream *tcp, uchar *pkt, int dport,
 	b->ip.hdr.tcp_xsum = 0;
 	b->ip.hdr.tcp_ugr = 0;
 
-	b->ip.hdr.tcp_xsum = tcp_set_pseudo_header(pkt, net_ip, net_server_ip,
+	b->ip.hdr.tcp_xsum = tcp_set_pseudo_header(pkt, net_ip, tcp->rhost,
 						   tcp_len, pkt_len);
 
-	net_set_ip_header((uchar *)&b->ip, net_server_ip, net_ip,
+	net_set_ip_header((uchar *)&b->ip, tcp->rhost, net_ip,
 			  pkt_len, IPPROTO_TCP);
 
 	return pkt_hdr_len;
@@ -616,19 +671,26 @@ void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len)
 	u32 tcp_seq_num, tcp_ack_num;
 	int tcp_hdr_len, payload_len;
 	struct tcp_stream *tcp;
+	struct in_addr src;
 
 	/* Verify IP header */
 	debug_cond(DEBUG_DEV_PKT,
 		   "TCP RX in RX Sum (to=%pI4, from=%pI4, len=%d)\n",
 		   &b->ip.hdr.ip_src, &b->ip.hdr.ip_dst, pkt_len);
 
-	b->ip.hdr.ip_src = net_server_ip;
+	/*
+	 * src IP address will be destroyed by TCP checksum verification
+	 * algorithm (see tcp_set_pseudo_header()), so remember it before
+	 * it was garbaged.
+	 */
+	src.s_addr = b->ip.hdr.ip_src.s_addr;
+
 	b->ip.hdr.ip_dst = net_ip;
 	b->ip.hdr.ip_sum = 0;
 	if (tcp_rx_xsum != compute_ip_checksum(b, IP_HDR_SIZE)) {
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP RX IP xSum Error (%pI4, =%pI4, len=%d)\n",
-			   &net_ip, &net_server_ip, pkt_len);
+			   &net_ip, &src, pkt_len);
 		return;
 	}
 
@@ -640,11 +702,14 @@ void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len)
 						 pkt_len)) {
 		debug_cond(DEBUG_DEV_PKT,
 			   "TCP RX TCP xSum Error (%pI4, %pI4, len=%d)\n",
-			   &net_ip, &net_server_ip, tcp_len);
+			   &net_ip, &src, tcp_len);
 		return;
 	}
 
-	tcp = tcp_stream_get();
+	tcp = tcp_stream_get(b->ip.hdr.tcp_flags & TCP_SYN,
+			     src,
+			     ntohs(b->ip.hdr.tcp_src),
+			     ntohs(b->ip.hdr.tcp_dst));
 	if (!tcp)
 		return;
 
@@ -676,9 +741,9 @@ void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len)
 			   "TCP Notify (action=%x, Seq=%u,Ack=%u,Pay%d)\n",
 			   tcp_action, tcp_seq_num, tcp_ack_num, payload_len);
 
-		(*tcp_packet_handler) ((uchar *)b + pkt_len - payload_len, b->ip.hdr.tcp_dst,
-				       b->ip.hdr.ip_src, b->ip.hdr.tcp_src, tcp_seq_num,
-				       tcp_ack_num, tcp_action, payload_len);
+		(*tcp_packet_handler) (tcp, (uchar *)b + pkt_len - payload_len,
+				       tcp_seq_num, tcp_ack_num, tcp_action,
+				       payload_len);
 
 	} else if (tcp_action != TCP_DATA) {
 		debug_cond(DEBUG_DEV_PKT,
@@ -689,9 +754,13 @@ void rxhand_tcp_f(union tcp_build_pkt *b, unsigned int pkt_len)
 		 * Warning: Incoming Ack & Seq sequence numbers are transposed
 		 * here to outgoing Seq & Ack sequence numbers
 		 */
-		net_send_tcp_packet(0, ntohs(b->ip.hdr.tcp_src),
-				    ntohs(b->ip.hdr.tcp_dst),
+		net_send_tcp_packet(0, tcp->rhost, tcp->rport, tcp->lport,
 				    (tcp_action & (~TCP_PUSH)),
 				    tcp_ack_num, tcp->ack_edge);
 	}
 }
+
+struct tcp_stream *tcp_stream_connect(struct in_addr rhost, u16 rport)
+{
+	return tcp_stream_add(rhost, rport, random_port());
+}