[PATCH 1/2] CIFS: Simplify ipv*_connect functions into one (try #2)

[Pavel Shilovsky <piastryyy-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

Make connect logic more ip-protocol independent. Also move RFC1001 stuff into
separate function.

Signed-off-by: Pavel Shilovsky <piastryyy-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
 fs/cifs/connect.c |  314 ++++++++++++++++++++---------------------------------
 1 files changed, 116 insertions(+), 198 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 251a17c..8bdf1cc 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -114,8 +114,8 @@ struct smb_vol {
 #define TLINK_ERROR_EXPIRE	(1 * HZ)
 #define TLINK_IDLE_EXPIRE	(600 * HZ)
 
-static int ipv4_connect(struct TCP_Server_Info *server);
-static int ipv6_connect(struct TCP_Server_Info *server);
+static int ip_connect(struct TCP_Server_Info *server);
+static int generic_ip_connect(struct TCP_Server_Info *server);
 static void tlink_rb_insert(struct rb_root *root, struct tcon_link *new_tlink);
 static void cifs_prune_tlinks(struct work_struct *work);
 
@@ -199,10 +199,10 @@ cifs_reconnect(struct TCP_Server_Info *server)
 	while ((server->tcpStatus != CifsExiting) &&
 	       (server->tcpStatus != CifsGood)) {
 		try_to_freeze();
-		if (server->addr.sockAddr6.sin6_family == AF_INET6)
-			rc = ipv6_connect(server);
-		else
-			rc = ipv4_connect(server);
+
+		/* on reconnect we should try only the port we connected
+		   before */
+		rc = generic_ip_connect(server);
 		if (rc) {
 			cFYI(1, "reconnect error %d", rc);
 			msleep(3000);
@@ -1668,12 +1668,11 @@ cifs_get_tcp_session(struct smb_vol *volume_info)
 		/* other OS never observed in Wild doing 139 with v6 */
 		memcpy(&tcp_ses->addr.sockAddr6, sin_server6,
 			sizeof(struct sockaddr_in6));
-		rc = ipv6_connect(tcp_ses);
-	} else {
+	} else
 		memcpy(&tcp_ses->addr.sockAddr, sin_server,
 			sizeof(struct sockaddr_in));
-		rc = ipv4_connect(tcp_ses);
-	}
+
+	rc = ip_connect(tcp_ses);
 	if (rc < 0) {
 		cERROR(1, "Error connecting to socket. Aborting operation");
 		goto out_err_crypto_release;
@@ -2121,19 +2120,97 @@ bind_socket(struct TCP_Server_Info *server)
 }
 
 static int
-ipv4_connect(struct TCP_Server_Info *server)
+ip_rfc1001_connect(struct TCP_Server_Info *server)
+{
+	int rc = 0;
+	/* some servers require RFC1001 sessinit before sending
+	negprot - BB check reconnection in case where second
+	sessinit is sent but no second negprot */
+	struct rfc1002_session_packet *ses_init_buf;
+	struct smb_hdr *smb_buf;
+	ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
+			       GFP_KERNEL);
+	if (ses_init_buf) {
+		ses_init_buf->trailer.session_req.called_len = 32;
+
+		if (server->server_RFC1001_name &&
+		    server->server_RFC1001_name[0] != 0)
+			rfc1002mangle(ses_init_buf->trailer.
+				      session_req.called_name,
+				      server->server_RFC1001_name,
+				      RFC1001_NAME_LEN_WITH_NULL);
+		else
+			rfc1002mangle(ses_init_buf->trailer.
+				      session_req.called_name,
+				      DEFAULT_CIFS_CALLED_NAME,
+				      RFC1001_NAME_LEN_WITH_NULL);
+
+		ses_init_buf->trailer.session_req.calling_len = 32;
+
+		/* calling name ends in null (byte 16) from old smb
+		convention. */
+		if (server->workstation_RFC1001_name &&
+		    server->workstation_RFC1001_name[0] != 0)
+			rfc1002mangle(ses_init_buf->trailer.
+				      session_req.calling_name,
+				      server->workstation_RFC1001_name,
+				      RFC1001_NAME_LEN_WITH_NULL);
+		else
+			rfc1002mangle(ses_init_buf->trailer.
+				      session_req.calling_name,
+				      "LINUX_CIFS_CLNT",
+				      RFC1001_NAME_LEN_WITH_NULL);
+
+		ses_init_buf->trailer.session_req.scope1 = 0;
+		ses_init_buf->trailer.session_req.scope2 = 0;
+		smb_buf = (struct smb_hdr *)ses_init_buf;
+
+		/* sizeof RFC1002_SESSION_REQUEST with no scope */
+		smb_buf->smb_buf_length = 0x81000044;
+		rc = smb_send(server, smb_buf, 0x44);
+		kfree(ses_init_buf);
+		msleep(1); /* RFC1001 layer in at least one server
+			      requires very short break before negprot
+			      presumably because not expecting negprot
+			      to follow so fast.  This is a simple
+			      solution that works without
+			      complicating the code and causes no
+			      significant slowing down on mount
+			      for everyone else */
+	}
+	/* else the negprot may still work without this
+	even though malloc failed */
+
+	return rc;
+}
+
+static int
+generic_ip_connect(struct TCP_Server_Info *server)
 {
 	int rc = 0;
-	int val;
-	bool connected = false;
-	__be16 orig_port = 0;
+	bool using_ipv6 = false;
+	unsigned short int *sport;
+	int slen;
 	struct socket *socket = server->ssocket;
+	struct sockaddr *saddr;
+
+	if (server->addr.sockAddr6.sin6_family == AF_INET6) {
+		sport = &server->addr.sockAddr6.sin6_port;
+		using_ipv6 = true;
+		slen = sizeof(struct sockaddr_in6);
+		saddr = (struct sockaddr *) &server->addr.sockAddr6;
+	} else {
+		sport = &server->addr.sockAddr.sin_port;
+		slen = sizeof(struct sockaddr_in);
+		saddr = (struct sockaddr *) &server->addr.sockAddr;
+	}
 
 	if (socket == NULL) {
 		rc = sock_create_kern(PF_INET, SOCK_STREAM,
 				      IPPROTO_TCP, &socket);
 		if (rc < 0) {
 			cERROR(1, "Error %d creating socket", rc);
+			server->ssocket = NULL;
 			return rc;
 		}
 
@@ -2141,59 +2218,24 @@ ipv4_connect(struct TCP_Server_Info *server)
 		cFYI(1, "Socket created");
 		server->ssocket = socket;
 		socket->sk->sk_allocation = GFP_NOFS;
-		cifs_reclassify_socket4(socket);
+		if (using_ipv6)
+			cifs_reclassify_socket6(socket);
+		else
+			cifs_reclassify_socket4(socket);
 	}
 
 	rc = bind_socket(server);
 	if (rc < 0)
 		return rc;
 
-	/* user overrode default port */
-	if (server->addr.sockAddr.sin_port) {
-		rc = socket->ops->connect(socket, (struct sockaddr *)
-					  &server->addr.sockAddr,
-					  sizeof(struct sockaddr_in), 0);
-		if (rc >= 0)
-			connected = true;
-	}
-
-	if (!connected) {
-		/* save original port so we can retry user specified port
-			later if fall back ports fail this time  */
-		orig_port = server->addr.sockAddr.sin_port;
-
-		/* do not retry on the same port we just failed on */
-		if (server->addr.sockAddr.sin_port != htons(CIFS_PORT)) {
-			server->addr.sockAddr.sin_port = htons(CIFS_PORT);
-			rc = socket->ops->connect(socket,
-						(struct sockaddr *)
-						&server->addr.sockAddr,
-						sizeof(struct sockaddr_in), 0);
-			if (rc >= 0)
-				connected = true;
-		}
-	}
-	if (!connected) {
-		server->addr.sockAddr.sin_port = htons(RFC1001_PORT);
-		rc = socket->ops->connect(socket, (struct sockaddr *)
-					      &server->addr.sockAddr,
-					      sizeof(struct sockaddr_in), 0);
-		if (rc >= 0)
-			connected = true;
-	}
-
-	/* give up here - unless we want to retry on different
-		protocol families some day */
-	if (!connected) {
-		if (orig_port)
-			server->addr.sockAddr.sin_port = orig_port;
-		cFYI(1, "Error %d connecting to server via ipv4", rc);
+	rc = socket->ops->connect(socket, saddr, slen, 0);
+	if (rc < 0) {
+		cFYI(1, "Error %d connecting to server", rc);
 		sock_release(socket);
 		server->ssocket = NULL;
 		return rc;
 	}
 
-
 	/*
 	 * Eventually check for other socket options to change from
 	 *  the default. sock_setsockopt not used because it expects
@@ -2211,7 +2253,7 @@ ipv4_connect(struct TCP_Server_Info *server)
 	}
 
 	if (server->tcp_nodelay) {
-		val = 1;
+		int val = 1;
 		rc = kernel_setsockopt(socket, SOL_TCP, TCP_NODELAY,
 				(char *)&val, sizeof(val));
 		if (rc)
@@ -2222,161 +2264,37 @@ ipv4_connect(struct TCP_Server_Info *server)
 		 socket->sk->sk_sndbuf,
 		 socket->sk->sk_rcvbuf, socket->sk->sk_rcvtimeo);
 
-	/* send RFC1001 sessinit */
-	if (server->addr.sockAddr.sin_port == htons(RFC1001_PORT)) {
-		/* some servers require RFC1001 sessinit before sending
-		negprot - BB check reconnection in case where second
-		sessinit is sent but no second negprot */
-		struct rfc1002_session_packet *ses_init_buf;
-		struct smb_hdr *smb_buf;
-		ses_init_buf = kzalloc(sizeof(struct rfc1002_session_packet),
-				       GFP_KERNEL);
-		if (ses_init_buf) {
-			ses_init_buf->trailer.session_req.called_len = 32;
-			if (server->server_RFC1001_name &&
-			    server->server_RFC1001_name[0] != 0)
-				rfc1002mangle(ses_init_buf->trailer.
-						session_req.called_name,
-					      server->server_RFC1001_name,
-					      RFC1001_NAME_LEN_WITH_NULL);
-			else
-				rfc1002mangle(ses_init_buf->trailer.
-						session_req.called_name,
-					      DEFAULT_CIFS_CALLED_NAME,
-					      RFC1001_NAME_LEN_WITH_NULL);
-
-			ses_init_buf->trailer.session_req.calling_len = 32;
-
-			/* calling name ends in null (byte 16) from old smb
-			convention. */
-			if (server->workstation_RFC1001_name &&
-			    server->workstation_RFC1001_name[0] != 0)
-				rfc1002mangle(ses_init_buf->trailer.
-						session_req.calling_name,
-					      server->workstation_RFC1001_name,
-					      RFC1001_NAME_LEN_WITH_NULL);
-			else
-				rfc1002mangle(ses_init_buf->trailer.
-						session_req.calling_name,
-					      "LINUX_CIFS_CLNT",
-					      RFC1001_NAME_LEN_WITH_NULL);
-
-			ses_init_buf->trailer.session_req.scope1 = 0;
-			ses_init_buf->trailer.session_req.scope2 = 0;
-			smb_buf = (struct smb_hdr *)ses_init_buf;
-			/* sizeof RFC1002_SESSION_REQUEST with no scope */
-			smb_buf->smb_buf_length = 0x81000044;
-			rc = smb_send(server, smb_buf, 0x44);
-			kfree(ses_init_buf);
-			msleep(1); /* RFC1001 layer in at least one server
-				      requires very short break before negprot
-				      presumably because not expecting negprot
-				      to follow so fast.  This is a simple
-				      solution that works without
-				      complicating the code and causes no
-				      significant slowing down on mount
-				      for everyone else */
-		}
-		/* else the negprot may still work without this
-		even though malloc failed */
-
-	}
+	if (*sport == htons(RFC1001_PORT))
+		rc = ip_rfc1001_connect(server);
 
 	return rc;
 }
 
 static int
-ipv6_connect(struct TCP_Server_Info *server)
+ip_connect(struct TCP_Server_Info *server)
 {
-	int rc = 0;
-	int val;
-	bool connected = false;
-	__be16 orig_port = 0;
-	struct socket *socket = server->ssocket;
+	unsigned short int *sport;
 
-	if (socket == NULL) {
-		rc = sock_create_kern(PF_INET6, SOCK_STREAM,
-				      IPPROTO_TCP, &socket);
-		if (rc < 0) {
-			cERROR(1, "Error %d creating ipv6 socket", rc);
-			socket = NULL;
-			return rc;
-		}
+	if (server->addr.sockAddr6.sin6_family == AF_INET6)
+		sport = &server->addr.sockAddr6.sin6_port;
+	else
+		sport = &server->addr.sockAddr.sin_port;
 
-		/* BB other socket options to set KEEPALIVE, NODELAY? */
-		cFYI(1, "ipv6 Socket created");
-		server->ssocket = socket;
-		socket->sk->sk_allocation = GFP_NOFS;
-		cifs_reclassify_socket6(socket);
-	}
+	if (*sport == 0) {
+		int rc;
 
-	rc = bind_socket(server);
-	if (rc < 0)
-		return rc;
+		/* try with 445 port at first */
+		*sport = htons(CIFS_PORT);
 
-	/* user overrode default port */
-	if (server->addr.sockAddr6.sin6_port) {
-		rc = socket->ops->connect(socket,
-				(struct sockaddr *) &server->addr.sockAddr6,
-				sizeof(struct sockaddr_in6), 0);
+		rc = generic_ip_connect(server);
 		if (rc >= 0)
-			connected = true;
-	}
-
-	if (!connected) {
-		/* save original port so we can retry user specified port
-			later if fall back ports fail this time  */
-
-		orig_port = server->addr.sockAddr6.sin6_port;
-		/* do not retry on the same port we just failed on */
-		if (server->addr.sockAddr6.sin6_port != htons(CIFS_PORT)) {
-			server->addr.sockAddr6.sin6_port = htons(CIFS_PORT);
-			rc = socket->ops->connect(socket, (struct sockaddr *)
-					&server->addr.sockAddr6,
-					sizeof(struct sockaddr_in6), 0);
-			if (rc >= 0)
-				connected = true;
-		}
-	}
-	if (!connected) {
-		server->addr.sockAddr6.sin6_port = htons(RFC1001_PORT);
-		rc = socket->ops->connect(socket, (struct sockaddr *)
-				&server->addr.sockAddr6,
-				sizeof(struct sockaddr_in6), 0);
-		if (rc >= 0)
-			connected = true;
-	}
-
-	/* give up here - unless we want to retry on different
-		protocol families some day */
-	if (!connected) {
-		if (orig_port)
-			server->addr.sockAddr6.sin6_port = orig_port;
-		cFYI(1, "Error %d connecting to server via ipv6", rc);
-		sock_release(socket);
-		server->ssocket = NULL;
-		return rc;
-	}
-
-	/*
-	 * Eventually check for other socket options to change from
-	 * the default. sock_setsockopt not used because it expects
-	 * user space buffer
-	 */
-	socket->sk->sk_rcvtimeo = 7 * HZ;
-	socket->sk->sk_sndtimeo = 5 * HZ;
+			return rc;
 
-	if (server->tcp_nodelay) {
-		val = 1;
-		rc = kernel_setsockopt(socket, SOL_TCP, TCP_NODELAY,
-				(char *)&val, sizeof(val));
-		if (rc)
-			cFYI(1, "set TCP_NODELAY socket option error %d", rc);
+		/* if it failed, try with 139 port */
+		*sport = htons(RFC1001_PORT);
 	}
 
-	server->ssocket = socket;
-
-	return rc;
+	return generic_ip_connect(server);
 }
 
 void reset_cifs_unix_caps(int xid, struct cifsTconInfo *tcon,
-- 
1.7.3.2