Use correct constant name.

This alters the meaning of NBD_MAX_SIZE to be the actual max request size
we'll accept over nbd.  Previously it was *nearly* the max size we'd
accept depending on the size of the struct.

debian/changelog

@@ -1,3 +1,16 @@
+flexnbd (0.1.8) UNRELEASED; urgency=medium
+
+  * Set TCP keepalive on sockets so broken connections are reaped (#33, !33)
+  * Add a context to logs to make debugging problems easier (#34, !34)
+
+ -- James Carter <james.carter@bytemark.co.uk>  Thu, 11 Jan 2018 10:05:35 +0000
+
+flexnbd (0.1.7) stable; urgency=medium
+
+  * Return bytes_left in migration statistics.
+
+ -- Chris Elsworth <chris.elsworth@bytemark.co.uk>  Fri, 14 Jul 2017 17:00:38 +0100
+
 flexnbd (0.1.6) stable; urgency=medium
 
   * Remove lots of per-cpu compiler flags, notably march=native.

src/common/nbdtypes.h

@@ -16,7 +16,7 @@
 
 
 /* 1MiB is the de-facto standard for maximum size of header + data */
-#define NBD_MAX_SIZE ( 1024 * 1024 )
+#define NBD_MAX_SIZE ( 32 * 1024 * 1024 )
 
 #define NBD_REQUEST_SIZE ( sizeof( struct nbd_request_raw ) )
 #define NBD_REPLY_SIZE   ( sizeof( struct nbd_reply_raw ) )

src/common/sockutil.c

@@ -68,6 +68,37 @@ int sock_set_reuseaddr( int fd, int optval )
 	return setsockopt( fd, SOL_SOCKET, SO_REUSEADDR, &optval, sizeof(optval) );
 }
 
+int sock_set_keepalive_params( int fd, int time, int intvl, int probes)
+{
+	if (sock_set_keepalive(fd, 1) ||
+		sock_set_tcp_keepidle(fd, time) ||
+		sock_set_tcp_keepintvl(fd, intvl) ||
+		sock_set_tcp_keepcnt(fd, probes)) {
+		return -1;
+	}
+	return 0;
+}
+
+int sock_set_keepalive( int fd, int optval )
+{
+	return setsockopt( fd, SOL_SOCKET, SO_KEEPALIVE, &optval, sizeof(optval) );
+}
+
+int sock_set_tcp_keepidle( int fd, int optval )
+{
+	return setsockopt( fd, IPPROTO_TCP, TCP_KEEPIDLE, &optval, sizeof(optval) );
+}
+
+int sock_set_tcp_keepintvl( int fd, int optval )
+{
+	return setsockopt( fd, IPPROTO_TCP, TCP_KEEPINTVL, &optval, sizeof(optval) );
+}
+
+int sock_set_tcp_keepcnt( int fd, int optval )
+{
+	return setsockopt( fd, IPPROTO_TCP, TCP_KEEPCNT, &optval, sizeof(optval) );
+}
+
 /* Set the tcp_nodelay option */
 int sock_set_tcp_nodelay( int fd, int optval )
 {

src/common/sockutil.h

@@ -14,9 +14,24 @@ size_t sockaddr_size(const struct sockaddr* sa);
  */
 const char* sockaddr_address_string(const struct sockaddr* sa, char* dest, size_t len);
 
+/* Configure TCP keepalive on a socket */
+int sock_set_keepalive_params( int fd, int time, int intvl, int probes);
+
+/* Set the SOL_KEEPALIVE otion */
+int sock_set_keepalive(int fd, int optval);
+
 /* Set the SOL_REUSEADDR otion */
 int sock_set_reuseaddr(int fd, int optval);
 
+/* Set the tcp_keepidle option */
+int sock_set_tcp_keepidle(int fd, int optval);
+
+/* Set the tcp_keepintvl option */
+int sock_set_tcp_keepintvl(int fd, int optval);
+
+/* Set the tcp_keepcnt option */
+int sock_set_tcp_keepcnt(int fd, int optval);
+
 /* Set the tcp_nodelay option */
 int sock_set_tcp_nodelay(int fd, int optval);
 

src/common/util.c

@@ -13,6 +13,7 @@
 pthread_key_t cleanup_handler_key;
 
 int log_level = 2;
+char *log_context = "";
 
 void error_init(void)
 {

src/common/util.h

@@ -21,6 +21,9 @@ extern int log_level;
 /* set up the error globals */
 void error_init(void);
 
+/* some context for the overall process that appears on each log line */
+extern char *log_context;
+
 
 void exit_err( const char * );
 
@@ -92,7 +95,7 @@ uint64_t monotonic_time_ms(void);
 
 #define levstr(i) (i==0?'D':(i==1?'I':(i==2?'W':(i==3?'E':'F'))))
 
-#define myloglev(level, msg, ...) mylog( level, "%"PRIu64":%c:%d %p %s:%d: "msg"\n", monotonic_time_ms(), levstr(level), getpid(),pthread_self(), __FILE__, __LINE__, ##__VA_ARGS__ )
+#define myloglev(level, msg, ...) mylog( level, "%"PRIu64":%c:%d %p %s %s:%d: "msg"\n", monotonic_time_ms(), levstr(level), getpid(),pthread_self(), log_context, __FILE__, __LINE__, ##__VA_ARGS__ )
 
 #ifdef DEBUG
 #  define debug(msg, ...) myloglev(0, msg, ##__VA_ARGS__)

src/proxy/proxy.c

@@ -76,8 +76,15 @@ struct proxier* proxy_create(
 	}
 
 	out->init.buf = xmalloc( sizeof( struct nbd_init_raw ) );
-	out->req.buf  = xmalloc( NBD_MAX_SIZE );
-	out->rsp.buf  = xmalloc( NBD_MAX_SIZE );
+
+	/* Add on the request / reply size to our malloc to accommodate both
+	 * the struct and the data
+	 */
+	out->req.buf  = xmalloc( NBD_MAX_SIZE + NBD_REQUEST_SIZE );
+	out->rsp.buf  = xmalloc( NBD_MAX_SIZE + NBD_REPLY_SIZE );
+
+	log_context = xmalloc( strlen(s_upstream_address) + strlen(s_upstream_port) + 2 );
+	sprintf(log_context, "%s:%s", s_upstream_address, s_upstream_port);
 
 	return out;
 }
@@ -437,15 +444,18 @@ int proxy_read_from_downstream( struct proxier *proxy, int state )
 			return EXIT;
 		}
 
-		/* Simple validations */
+		/* Simple validations -- the request / reply size have already
+		 * been taken into account in the xmalloc, so no need to worry
+		 * about them here
+		 */
 		if ( ( request->type & REQUEST_MASK ) == REQUEST_READ ) {
-			if (request->len > ( NBD_MAX_SIZE - NBD_REPLY_SIZE ) ) {
+			if ( request->len > NBD_MAX_SIZE ) {
 				warn( "NBD read request size %"PRIu32" too large", request->len );
 				return EXIT;
 			}
 		}
 		if ( (request->type & REQUEST_MASK ) == REQUEST_WRITE ) {
-			if (request->len > ( NBD_MAX_SIZE - NBD_REQUEST_SIZE ) ) {
+			if ( request->len > NBD_MAX_SIZE ) {
 				warn( "NBD write request size %"PRIu32" too large", request->len );
 				return EXIT;
 			}

src/server/serve.c

@@ -78,6 +78,8 @@ struct server * server_create (
 	NULLCHECK( out->close_signal );
 	NULLCHECK( out->acl_updated_signal );
 
+	log_context = s_file;
+
 	return out;
 }
 
@@ -422,6 +424,9 @@ void accept_nbd_client(
 	int slot;
 	char s_client_address[64] = {0};
 
+	FATAL_IF_NEGATIVE( sock_set_keepalive_params( client_fd, CLIENT_KEEPALIVE_TIME, CLIENT_KEEPALIVE_INTVL, CLIENT_KEEPALIVE_PROBES),
+		"Error setting keepalive parameters on client socket fd %d", client_fd );
+
 
 	if ( !server_should_accept_client( params, client_address, s_client_address, 64 ) ) {
 		FATAL_IF_NEGATIVE( close( client_fd ),

src/server/serve.h

@@ -21,6 +21,9 @@ struct client_tbl_entry {
 
 
 #define MAX_NBD_CLIENTS 16
+#define CLIENT_KEEPALIVE_TIME 30
+#define CLIENT_KEEPALIVE_INTVL 10
+#define CLIENT_KEEPALIVE_PROBES 3
 struct server {
 	/* The flexnbd wrapper this server is attached to */
 	struct flexnbd * flexnbd;