flexnbd: Add --bind to flexnbd read and flexnbd write

src/control.c

@@ -217,7 +217,7 @@ int control_mirror(struct control_params* client, int linesc, char** lines)
 		return -1;
 	}
 	
-	fd = socket_connect(&connect_to.generic);
+	fd = socket_connect(&connect_to.generic, NULL);
 	
 	remote_size = socket_nbd_read_hello(fd);
 	remote_size = remote_size; // shush compiler

src/flexnbd.c

@@ -111,6 +111,7 @@ void params_readwrite(
 	struct mode_readwrite_params* out,
 	char* s_ip_address,
 	char* s_port,
+	char* s_bind_address,
 	char* s_from,
 	char* s_length_or_filename
 )
@@ -128,6 +129,9 @@ void params_readwrite(
 		SERVER_ERROR("Couldn't parse connection address '%s'",
 		s_ip_address);
 
+	if (s_bind_address != NULL && parse_ip_to_sockaddr(&out->connect_from.generic, s_bind_address) == 0)
+		SERVER_ERROR("Couldn't parse bind address '%s'", s_bind_address);
+
 	/* FIXME: duplicated from above */
 	out->connect_to.v4.sin_port = atoi(s_port);
 	if (out->connect_to.v4.sin_port < 0 || out->connect_to.v4.sin_port > 65535)
@@ -198,7 +202,7 @@ void read_serve_param( int c, char **ip_addr, char **ip_port, char **file, char
 }
 
 
-void read_readwrite_param( int c, char **ip_addr, char **ip_port, char **from, char **size)
+void read_readwrite_param( int c, char **ip_addr, char **ip_port, char **bind_addr, char **from, char **size)
 {
 	switch(c){
 		case 'h':
@@ -217,6 +221,9 @@ void read_readwrite_param( int c, char **ip_addr, char **ip_port, char **from, c
 		case 'S':
 			*size = optarg;
 			break;
+		case 'b':
+			*bind_addr = optarg;
+			break;
 		case 'd':
 			set_debug(1);
 			break;
@@ -320,8 +327,9 @@ int mode_serve( int argc, char *argv[] )
 int mode_read( int argc, char *argv[] )
 {
 	int c;
-	char *ip_addr = NULL;
+	char *ip_addr   = NULL;
-	char *ip_port = NULL;
+	char *ip_port   = NULL;
+	char *bind_addr = NULL;
 	char *from = NULL;
 	char *size = NULL;
 	int err = 0;
@@ -330,8 +338,11 @@ int mode_read( int argc, char *argv[] )
 
 	while (1){
 		c = getopt_long(argc, argv, read_short_options, read_options, NULL);
-		if ( c == -1 ) break;
+
-		read_readwrite_param( c, &ip_addr, &ip_port, &from, &size );
+		if ( c == -1 )
+			break;
+
+		read_readwrite_param( c, &ip_addr, &ip_port, &bind_addr, &from, &size );
 	}
 
 	if ( NULL == ip_addr || NULL == ip_port ) {
@@ -345,7 +356,7 @@ int mode_read( int argc, char *argv[] )
 	if ( err ) { exit_err( read_help_text ); }
 
 	memset( &readwrite, 0, sizeof( readwrite ) );
-	params_readwrite( 0, &readwrite, ip_addr, ip_port, from, size );
+	params_readwrite( 0, &readwrite, ip_addr, ip_port, bind_addr, from, size );
 	do_read( &readwrite );
 	return 0;
 }
@@ -353,8 +364,9 @@ int mode_read( int argc, char *argv[] )
 int mode_write( int argc, char *argv[] )
 {
 	int c;
-	char *ip_addr = NULL;
+	char *ip_addr   = NULL;
-	char *ip_port = NULL;
+	char *ip_port   = NULL;
+	char *bind_addr = NULL;
 	char *from = NULL;
 	char *size = NULL;
 	int err = 0;
@@ -363,8 +375,10 @@ int mode_write( int argc, char *argv[] )
 
 	while (1){
 		c = getopt_long(argc, argv, write_short_options, write_options, NULL);
-		if ( c == -1 ) break;
+		if ( c == -1 )
-		read_readwrite_param( c, &ip_addr, &ip_port, &from, &size );
+			break;
+
+		read_readwrite_param( c, &ip_addr, &ip_port, &bind_addr, &from, &size );
 	}
 
 	if ( NULL == ip_addr || NULL == ip_port ) {
@@ -378,7 +392,7 @@ int mode_write( int argc, char *argv[] )
 	if ( err ) { exit_err( write_help_text ); }
 
 	memset( &readwrite, 0, sizeof( readwrite ) );
-	params_readwrite( 1, &readwrite, ip_addr, ip_port, from, size );
+	params_readwrite( 1, &readwrite, ip_addr, ip_port, bind_addr, from, size );
 	do_write( &readwrite );
 	return 0;
 }

src/options.h

@@ -3,6 +3,7 @@
 
 #define OPT_HELP "help"
 #define OPT_ADDR "addr"
+#define OPT_BIND "bind"
 #define OPT_PORT "port"
 #define OPT_FILE "file"
 #define OPT_SOCK "sock"
@@ -34,6 +35,7 @@
 #define GETOPT_SOCK GETOPT_ARG( OPT_SOCK, 's' )
 #define GETOPT_FROM GETOPT_ARG( OPT_FROM, 'F' )
 #define GETOPT_SIZE GETOPT_ARG( OPT_SIZE, 'S' )
+#define GETOPT_BIND GETOPT_ARG( OPT_BIND, 'b' )
 
 #ifdef DEBUG
 #  define OPT_DEBUG "debug"
@@ -45,6 +47,12 @@
 #  define DEBUG_LINE ""
 #endif
 
+#define HELP_LINE \
+	"\t--" OPT_HELP  ",-h       \tThis text.\n"
+#define SOCK_LINE \
+	"\t--" OPT_SOCK  ",-s <SOCK>\tPath to the control socket.\n"
+#define BIND_LINE \
+	 "\t--" OPT_BIND ",-b <ADDR>\tBind the local socket to a particular IP address.\n"
 
 static struct option serve_options[] = {
 	GETOPT_HELP,
@@ -60,12 +68,12 @@ static char serve_short_options[] = "Dhl:p:f:s:";
 static char serve_help_text[] =
 	"Usage: flexnbd " CMD_SERVE " <options> [<acl address>*]\n\n"
 	"Serve FILE from ADDR:PORT, with an optional control socket at SOCK.\n\n"
-	"\t--" OPT_HELP ",-h\tThis text.\n"
+	HELP_LINE
 	"\t--" OPT_ADDR ",-l <ADDR>\tThe address to serve on.\n"
 	"\t--" OPT_PORT ",-p <PORT>\tThe port to serve on.\n"
 	"\t--" OPT_FILE ",-f <FILE>\tThe file to serve.\n"
-	"\t--" OPT_DENY ",-D\tDeny connections by default unless in ACL\n"
+	"\t--" OPT_DENY ",-D\tDeny connections by default unless in ACL.\n"
-	"\t--" OPT_SOCK ",-s <SOCK>\tPath to the control socket to open.\n"
+	SOCK_LINE
 	DEBUG_LINE;
 
 static struct option read_options[] = {
@@ -74,18 +82,20 @@ static struct option read_options[] = {
 	GETOPT_PORT,
 	GETOPT_FROM,
 	GETOPT_SIZE,
+	GETOPT_BIND,
 	GETOPT_DEBUG,
 	{0}
 };
-static char read_short_options[] = "hl:p:F:S:";
+static char read_short_options[] = "hl:p:F:S:b:";
 static char read_help_text[] =
 	"Usage: flexnbd " CMD_READ " <options>\n\n"
 	"Read SIZE bytes from a server at ADDR:PORT to stdout, starting at OFFSET.\n\n"
-	"\t--" OPT_HELP ",-h\tThis text.\n"
+	HELP_LINE
 	"\t--" OPT_ADDR ",-l <ADDR>\tThe address to read from.\n"
 	"\t--" OPT_PORT ",-p <PORT>\tThe port to read from.\n"
 	"\t--" OPT_FROM ",-F <OFFSET>\tByte offset to read from.\n"
 	"\t--" OPT_SIZE ",-S <SIZE>\tBytes to read.\n"
+	BIND_LINE
 	DEBUG_LINE;
 
 
@@ -94,11 +104,12 @@ static char *write_short_options = read_short_options;
 static char write_help_text[] =
 	"Usage: flexnbd " CMD_WRITE" <options>\n\n"
 	"Write SIZE bytes from stdin to a server at ADDR:PORT, starting at OFFSET.\n\n"
-	"\t--" OPT_HELP ",-h\tThis text.\n"
+	HELP_LINE
 	"\t--" OPT_ADDR ",-l <ADDR>\tThe address to write to.\n"
 	"\t--" OPT_PORT ",-p <PORT>\tThe port to write to.\n"
 	"\t--" OPT_FROM ",-F <OFFSET>\tByte offset to write from.\n"
 	"\t--" OPT_SIZE ",-S <SIZE>\tBytes to write.\n"
+	BIND_LINE
 	DEBUG_LINE;
 
 struct option acl_options[] = {
@@ -111,8 +122,8 @@ static char acl_short_options[] = "hs:";
 static char acl_help_text[] =
 	"Usage: flexnbd " CMD_ACL " <options> [<acl address>+]\n\n"
 	"Set the access control list for a server with control socket SOCK.\n\n"
-	"\t--" OPT_HELP ",-h\tThis text.\n"
+	HELP_LINE
-	"\t--" OPT_SOCK ",-s <SOCK>\tPath to the control socket.\n"
+	SOCK_LINE
 	DEBUG_LINE;
 
 struct option mirror_options[] = {
@@ -127,8 +138,7 @@ static char mirror_short_options[] = "hs:l:p:";
 static char mirror_help_text[] =
 	"Usage: flexnbd " CMD_MIRROR " <options>\n\n"
 	"Start mirroring from the server with control socket SOCK to one at ADDR:PORT.\n\n"
-	"\t--" OPT_HELP ",-h\tThis text.\n"
+	HELP_LINE
-	"\t--" OPT_SOCK ",-s <SOCK>\tPath to the control socket.\n"
 	"\t--" OPT_ADDR ",-l <ADDR>\tThe address to mirror to.\n"
 	"\t--" OPT_PORT ",-p <PORT>\tThe port to mirror to.\n"
 	DEBUG_LINE;
@@ -144,8 +154,8 @@ static char status_short_options[] = "hs:";
 static char status_help_text[] =
 	"Usage: flexnbd " CMD_STATUS " <options>\n\n"
 	"Get the status for a server with control socket SOCK.\n\n"
-	"\t--" OPT_HELP ",-h\tThis text.\n"
+	HELP_LINE
-	"\t--" OPT_SOCK ",-s <SOCK>\tPath to the control socket.\n"
+	SOCK_LINE
 	DEBUG_LINE;
 
 static char help_help_text[] =
@@ -159,3 +169,4 @@ static char help_help_text[] =
 	"\tflexnbd status\n"
 	"\tflexnbd help\n\n"
 	"See flexnbd help <cmd> for further info\n";
+

src/params.h

@@ -82,6 +82,7 @@ struct mode_serve_params {
 
 struct mode_readwrite_params {
 	union mysockaddr     connect_to;
+	union mysockaddr     connect_from;
 	off64_t              from;
 	off64_t              len;
 	int                  data_fd;

src/readwrite.c

@@ -7,12 +7,20 @@
 #include <string.h>
 #include <sys/socket.h>
 
-int socket_connect(struct sockaddr* to)
+int socket_connect(struct sockaddr* to, struct sockaddr* from)
 {
 	int fd = socket(to->sa_family == AF_INET ? PF_INET : PF_INET6, SOCK_STREAM, 0);
 	SERVER_ERROR_ON_FAILURE(fd, "Couldn't create client socket");
-	SERVER_ERROR_ON_FAILURE(connect(fd, to, sizeof(struct sockaddr_in6)),
+
-	  "connect failed");
+	if (NULL != from)
+		SERVER_ERROR_ON_FAILURE(
+			bind(fd, from, sizeof(struct sockaddr_in6)),
+			"bind() failed"
+		);
+
+	SERVER_ERROR_ON_FAILURE(
+		connect(fd, to, sizeof(struct sockaddr_in6)),"connect failed"
+	);
 	return fd;
 }
 
@@ -106,7 +114,7 @@ void socket_nbd_write(int fd, off64_t from, int len, int in_fd, void* in_buf)
   
 void do_read(struct mode_readwrite_params* params)
 {
-	params->client = socket_connect(&params->connect_to.generic);
+	params->client = socket_connect(&params->connect_to.generic, &params->connect_from.generic);
 	CHECK_RANGE("read");
 	socket_nbd_read(params->client, params->from, params->len, 
 	  params->data_fd, NULL);
@@ -115,7 +123,7 @@ void do_read(struct mode_readwrite_params* params)
 
 void do_write(struct mode_readwrite_params* params)
 {
-	params->client = socket_connect(&params->connect_to.generic);
+	params->client = socket_connect(&params->connect_to.generic, &params->connect_from.generic);
 	CHECK_RANGE("write");
 	socket_nbd_write(params->client, params->from, params->len, 
 	  params->data_fd, NULL);

src/readwrite.h

@@ -2,7 +2,7 @@
 
 #define __READWRITE_H
 
-int socket_connect(struct sockaddr* to);
+int socket_connect(struct sockaddr* to, struct sockaddr* from);
 off64_t socket_nbd_read_hello(int fd);
 void socket_nbd_read(int fd, off64_t from, int len, int out_fd, void* out_buf);
 void socket_nbd_write(int fd, off64_t from, int len, int out_fd, void* out_buf);