diff --git a/.hgignore b/.hgignore
index 9cec915..1b4b5a4 100644
--- a/.hgignore
+++ b/.hgignore
@@ -1,3 +1,5 @@
 .o$
 ~$
 ^flexnbd$
+^build/
+^pkg/
diff --git a/Rakefile b/Rakefile
index a8d47cc..beebc72 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,7 +1,9 @@
 DEBUG  = true
 
-SOURCES = %w( flexnbd ioutil readwrite serve util parse control remote )
-OBJECTS = SOURCES.map { |s| "#{s}.o" }
+ALL_SOURCES =FileList['src/*']
+SOURCES = ALL_SOURCES.select { |c| c =~ /\.c$/ }
+OBJECTS = SOURCES.pathmap( "%{^src,build}X.o" )
+
 LIBS    = %w( pthread )
 CCFLAGS = %w( -Wall )
 LDFLAGS = []
@@ -15,52 +17,66 @@ if DEBUG
 end
 
 desc "Build flexnbd binary"
-rule 'default' => 'flexnbd'
+task :flexnbd => 'build/flexnbd'
 
 namespace "test" do
   desc "Run all tests"
   task 'run' => ["unit", "scenarios"]
-  
+
   desc "Build C tests"
-  task 'build' => TEST_MODULES.map { |n| "tests/check_#{n}" }
-  
+  task 'build' => TEST_MODULES.map { |n| "build/tests/check_#{n}" }
+
   desc "Run C tests"
   task 'unit' => 'build' do
     TEST_MODULES.each do |n|
       ENV['EF_DISABLE_BANNER'] = '1'
-      sh "./tests/check_#{n}"
+      sh "build/tests/check_#{n}"
     end
   end
-  
+
   desc "Run NBD test scenarios"
   task 'scenarios' => 'flexnbd' do
     sh "cd tests; ruby nbd_scenarios"
   end
 end
 
+
 def gcc_link(target, objects)
+  FileUtils.mkdir_p File.dirname( target )
+
   sh "gcc #{LDFLAGS.join(' ')} "+
     LIBS.map { |l| "-l#{l}" }.join(" ")+
+    " -I src" +
     " -o #{target} "+
     objects.join(" ")
 end
 
-rule 'flexnbd' => OBJECTS do |t|
+rule 'build/flexnbd' => OBJECTS do |t|
   gcc_link(t.name, t.sources)
 end
 
-rule(/tests\/check_[a-z]+$/ => [ proc { |target| [target+".o", "util.o"] } ]) do |t|
-  gcc_link(t.name, t.sources + [LIBCHECK])
+TEST_MODULES.each do |m|
+  deps = ["tests/check_#{m}.c", "build/util.o"]
+  maybe_obj_name = "build/#{m}.o"
+
+  deps << maybe_obj_name if OBJECTS.include?( maybe_obj_name )
+
+  file "build/tests/check_#{m}" => deps do |t|
+    gcc_link(t.name, deps + [LIBCHECK])
+  end
 end
 
-rule '.o' => '.c' do |t|
-  sh "gcc -I. -c #{CCFLAGS.join(' ')} -o #{t.name} #{t.source} "
+
+OBJECTS.zip( SOURCES ).each do |o,c|
+  file o => c do |t|
+    FileUtils.mkdir_p File.dirname( o )
+    sh "gcc -Isrc -c #{CCFLAGS.join(' ')} -o #{o} #{c} "
+  end
 end
 
 desc "Remove all build targets, binaries and temporary files"
 rule 'clean' do
-  sh "rm -f *~ flexnbd " + (
-    OBJECTS + 
+  sh "rm -rf *~ build " + (
     TEST_MODULES.map { |n| ["tests/check_#{n}", "tests/check_#{n}.o"] }.flatten
   ).
   join(" ")
diff --git a/flexnbd.c b/flexnbd.c
deleted file mode 100644
index 9029eb3..0000000
--- a/flexnbd.c
+++ /dev/null
@@ -1,222 +0,0 @@
-/*  FlexNBD server (C) Bytemark Hosting 2012
-
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
-
-    This program is distributed in the hope that it will be useful,
-    but WITHOUT ANY WARRANTY; without even the implied warranty of
-    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-    GNU General Public License for more details.
-
-    You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*/
-
-/** main() function for parsing and dispatching commands.  Each mode has
- *  a corresponding structure which is filled in and passed to a do_ function
- *  elsewhere in the program.
- */
-
-#include "params.h"
-#include "util.h"
-
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <signal.h>
-
-void syntax()
-{
-	fprintf(stderr, 
-	"Syntax: flexnbd serve  <listen IP address> <port> <file> \\\n"
-	"                          [full path to control socket] \\\n"
-	"                          [allowed connection addresses ...]\n"
-	"        flexnbd read   <IP address> <port> <offset> <length> > data\n"
-	"        flexnbd write  <IP address> <port> <offset> <length> < data\n"
-	"        flexnbd write  <IP address> <port> <offset> <file to write>\n"
-	"        flexnbd acl    <control socket> [allowed connection addresses ...]\n"
-	"        flexnbd mirror <control socket> <dst IP address> <dst port>\n"
-	"                          [bytes per second] [proxy|nothing|exit]\n"
-	"        flexnbd status <control socket>\n"
-	);
-	exit(1);
-}
-
-void params_serve(
-	struct mode_serve_params* out, 
-	char* s_ip_address, 
-	char* s_port, 
-	char* s_file,
-	int acl_entries,
-	char** s_acl_entries /* first may actually be path to control socket */
-)
-{
-	int parsed;
-	
-	out->tcp_backlog = 10; /* does this need to be settable? */
-	
-	if (s_ip_address == NULL)
-		SERVER_ERROR("No IP address supplied");
-	if (s_port == NULL)
-		SERVER_ERROR("No port number supplied");
-	if (s_file == NULL)
-		SERVER_ERROR("No filename supplied");
-	
-	if (parse_ip_to_sockaddr(&out->bind_to.generic, s_ip_address) == 0)
-		SERVER_ERROR("Couldn't parse server address '%s' (use 0 if "
-		  "you want to bind to all IPs)", s_ip_address);
-	
-	out->control_socket_name = NULL;
-	
-	if (acl_entries > 0 && s_acl_entries[0][0] == '/') {
-		out->control_socket_name = s_acl_entries[0];
-		s_acl_entries++;
-		acl_entries--;		
-	}
-	
-	out->acl_entries = acl_entries;
-	parsed = parse_acl(&out->acl, acl_entries, s_acl_entries);
-	if (parsed != acl_entries)
-		SERVER_ERROR("Bad ACL entry '%s'", s_acl_entries[parsed]);
-	
-	out->bind_to.v4.sin_port = atoi(s_port);
-	if (out->bind_to.v4.sin_port < 0 || out->bind_to.v4.sin_port > 65535)
-		SERVER_ERROR("Port number must be >= 0 and <= 65535");
-	out->bind_to.v4.sin_port = htobe16(out->bind_to.v4.sin_port);
-	
-	out->filename = s_file;
-	out->filename_incomplete = xmalloc(strlen(s_file)+11);
-	strcpy(out->filename_incomplete, s_file);
-	strcpy(out->filename_incomplete + strlen(s_file), ".INCOMPLETE");
-}
-
-void params_readwrite(
-	int write_not_read,
-	struct mode_readwrite_params* out,
-	char* s_ip_address, 
-	char* s_port,
-	char* s_from,
-	char* s_length_or_filename
-)
-{
-	if (s_ip_address == NULL)
-		SERVER_ERROR("No IP address supplied");
-	if (s_port == NULL)
-		SERVER_ERROR("No port number supplied");
-	if (s_from == NULL)
-		SERVER_ERROR("No from supplied");
-	if (s_length_or_filename == NULL)
-		SERVER_ERROR("No length supplied");
-	
-	if (parse_ip_to_sockaddr(&out->connect_to.generic, s_ip_address) == 0)
-		SERVER_ERROR("Couldn't parse connection address '%s'", 
-		s_ip_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)
-		SERVER_ERROR("Port number must be >= 0 and <= 65535");
-	out->connect_to.v4.sin_port = htobe16(out->connect_to.v4.sin_port);
-
-	out->from  = atol(s_from);
-	
-	if (write_not_read) {
-		if (s_length_or_filename[0]-48 < 10) {
-			out->len   = atol(s_length_or_filename);
-			out->data_fd = 0;
-		}
-		else {
-			out->data_fd = open(
-			  s_length_or_filename, O_RDONLY);
-			SERVER_ERROR_ON_FAILURE(out->data_fd,
-			  "Couldn't open %s", s_length_or_filename);
-			out->len = lseek64(out->data_fd, 0, SEEK_END);
-			SERVER_ERROR_ON_FAILURE(out->len,
-			  "Couldn't find length of %s", s_length_or_filename);
-			SERVER_ERROR_ON_FAILURE(
-				lseek64(out->data_fd, 0, SEEK_SET),
-				"Couldn't rewind %s", s_length_or_filename
-			);
-		}
-	}
-	else {
-		out->len = atol(s_length_or_filename);
-		out->data_fd = 1;
-	}
-}
-
-void do_serve(struct mode_serve_params* params);
-void do_read(struct mode_readwrite_params* params);
-void do_write(struct mode_readwrite_params* params);
-void do_remote_command(char* command, char* mode, int argc, char** argv);
-
-union mode_params {
-	struct mode_serve_params serve;
-	struct mode_readwrite_params readwrite;
-};
-
-void mode(char* mode, int argc, char **argv)
-{
-	union mode_params params;
-	memset(&params, 0, sizeof(params));
-	
-	if (strcmp(mode, "serve") == 0) {
-		if (argc >= 3) {
-			params_serve(&params.serve, argv[0], argv[1], argv[2], argc-3, argv+3);
-			do_serve(&params.serve);
-		}
-		else {
-			syntax();
-		}
-	}
-	else if (strcmp(mode, "read") == 0 ) {
-		if (argc == 4) {
-			params_readwrite(0, &params.readwrite, argv[0], argv[1], argv[2], argv[3]);
-			do_read(&params.readwrite);
-		}
-		else {
-			syntax();
-		}
-	}
-	else if (strcmp(mode, "write") == 0 ) {
-		if (argc == 4) {
-			params_readwrite(1, &params.readwrite, argv[0], argv[1], argv[2], argv[3]);
-			do_write(&params.readwrite);
-		}
-		else {
-			syntax();
-		}
-	}
-	else if (strcmp(mode, "acl") == 0 || strcmp(mode, "mirror") == 0 || strcmp(mode, "status") == 0) {
-		if (argc >= 1) {
-			do_remote_command(mode, argv[0], argc-1, argv+1);
-		}
-		else {
-			syntax();
-		}
-	}
-	else {
-		syntax();
-	}
-	exit(0);
-}
-
-int main(int argc, char** argv)
-{
-	signal(SIGPIPE, SIG_IGN); /* calls to splice() unhelpfully throw this */
-	error_init(); 
-	
-	if (argc < 2)
-		syntax();
-	mode(argv[1], argc-2, argv+2); /* never returns */
-	
-	return 0;
-}
-
diff --git a/bitset.h b/src/bitset.h
similarity index 100%
rename from bitset.h
rename to src/bitset.h
diff --git a/control.c b/src/control.c
similarity index 100%
rename from control.c
rename to src/control.c
diff --git a/control.h b/src/control.h
similarity index 100%
rename from control.h
rename to src/control.h
diff --git a/src/flexnbd.c b/src/flexnbd.c
new file mode 100644
index 0000000..1acb911
--- /dev/null
+++ b/src/flexnbd.c
@@ -0,0 +1,511 @@
+/*  FlexNBD server (C) Bytemark Hosting 2012
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+/** main() function for parsing and dispatching commands.  Each mode has
+ *  a corresponding structure which is filled in and passed to a do_ function
+ *  elsewhere in the program.
+ */
+
+#include "params.h"
+#include "util.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <unistd.h>
+#include <signal.h>
+
+#include <getopt.h>
+#include "options.h"
+
+
+void exit_err( char *msg )
+{
+	fprintf( stderr, msg );
+	exit( 1 );
+}
+
+void params_serve(
+	struct mode_serve_params* out, 
+	char* s_ip_address, 
+	char* s_port, 
+	char* s_file,
+	char *s_ctrl_sock,
+	int acl_entries,
+	char** s_acl_entries /* first may actually be path to control socket */
+)
+{
+	int parsed;
+	
+	out->tcp_backlog = 10; /* does this need to be settable? */
+	
+	if (s_ip_address == NULL)
+		SERVER_ERROR("No IP address supplied");
+	if (s_port == NULL)
+		SERVER_ERROR("No port number supplied");
+	if (s_file == NULL)
+		SERVER_ERROR("No filename supplied");
+	
+	if (parse_ip_to_sockaddr(&out->bind_to.generic, s_ip_address) == 0)
+		SERVER_ERROR("Couldn't parse server address '%s' (use 0 if "
+		  "you want to bind to all IPs)", s_ip_address);
+
+	/* control_socket_name is optional. It just won't get created if
+	 * we pass NULL. */
+	out->control_socket_name = s_ctrl_sock;
+
+	out->acl_entries = acl_entries;
+	parsed = parse_acl(&out->acl, acl_entries, s_acl_entries);
+	if (parsed != acl_entries)
+		SERVER_ERROR("Bad ACL entry '%s'", s_acl_entries[parsed]);
+	
+	out->bind_to.v4.sin_port = atoi(s_port);
+	if (out->bind_to.v4.sin_port < 0 || out->bind_to.v4.sin_port > 65535)
+		SERVER_ERROR("Port number must be >= 0 and <= 65535");
+	out->bind_to.v4.sin_port = htobe16(out->bind_to.v4.sin_port);
+	
+	out->filename = s_file;
+	out->filename_incomplete = xmalloc(strlen(s_file)+11);
+	strcpy(out->filename_incomplete, s_file);
+	strcpy(out->filename_incomplete + strlen(s_file), ".INCOMPLETE");
+}
+
+/* TODO: Separate this function.
+ * It should be:
+ * params_read( struct mode_readwrite_params* out,
+ * 		char *s_ip_address,
+ * 		char *s_port,
+ * 		char *s_from,
+ * 		char *s_length )
+ * params_write( struct mode_readwrite_params* out,
+ * 		 char *s_ip_address,
+ *		 char *s_port,
+ *		 char *s_from,
+ *		 char *s_length,
+ *		 char *s_filename )
+ */
+void params_readwrite(
+	int write_not_read,
+	struct mode_readwrite_params* out,
+	char* s_ip_address, 
+	char* s_port,
+	char* s_from,
+	char* s_length_or_filename
+)
+{
+	if (s_ip_address == NULL)
+		SERVER_ERROR("No IP address supplied");
+	if (s_port == NULL)
+		SERVER_ERROR("No port number supplied");
+	if (s_from == NULL)
+		SERVER_ERROR("No from supplied");
+	if (s_length_or_filename == NULL)
+		SERVER_ERROR("No length supplied");
+	
+	if (parse_ip_to_sockaddr(&out->connect_to.generic, s_ip_address) == 0)
+		SERVER_ERROR("Couldn't parse connection address '%s'", 
+		s_ip_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)
+		SERVER_ERROR("Port number must be >= 0 and <= 65535");
+	out->connect_to.v4.sin_port = htobe16(out->connect_to.v4.sin_port);
+
+	out->from  = atol(s_from);
+	
+	if (write_not_read) {
+		if (s_length_or_filename[0]-48 < 10) {
+			out->len   = atol(s_length_or_filename);
+			out->data_fd = 0;
+		}
+		else {
+			out->data_fd = open(
+			  s_length_or_filename, O_RDONLY);
+			SERVER_ERROR_ON_FAILURE(out->data_fd,
+			  "Couldn't open %s", s_length_or_filename);
+			out->len = lseek64(out->data_fd, 0, SEEK_END);
+			SERVER_ERROR_ON_FAILURE(out->len,
+			  "Couldn't find length of %s", s_length_or_filename);
+			SERVER_ERROR_ON_FAILURE(
+				lseek64(out->data_fd, 0, SEEK_SET),
+				"Couldn't rewind %s", s_length_or_filename
+			);
+		}
+	}
+	else {
+		out->len = atol(s_length_or_filename);
+		out->data_fd = 1;
+	}
+}
+
+void do_serve(struct mode_serve_params* params);
+void do_read(struct mode_readwrite_params* params);
+void do_write(struct mode_readwrite_params* params);
+void do_remote_command(char* command, char* mode, int argc, char** argv);
+
+void read_serve_param( int c, char **ip_addr, char **ip_port, char **file, char **sock )
+{
+	switch(c){
+		case 'h':
+			fprintf(stdout, serve_help_text );
+			exit( 0 );
+			break;
+		case 'l':
+			*ip_addr = optarg;
+			break;
+		case 'p':
+			*ip_port = optarg;
+			break;
+		case 'f':
+			*file = optarg;
+			break;
+		case 's':
+			*sock = optarg;
+			break;
+		default:
+			exit_err( serve_help_text );
+			break;
+	}
+}
+
+
+void read_readwrite_param( int c, char **ip_addr, char **ip_port, char **from, char **size)
+{
+	switch(c){
+		case 'h':
+			fprintf(stdout, read_help_text );
+			exit( 0 );
+			break;
+		case 'l':
+			*ip_addr = optarg;
+			break;
+		case 'p':
+			*ip_port = optarg;
+			break;
+		case 'F':
+			*from = optarg;
+			break;
+		case 'S':
+			*size = optarg;
+			break;
+		default:
+			exit_err( read_help_text );
+			break;
+	}
+}
+
+void read_sock_param( int c, char **sock, char *help_text )
+{
+	switch(c){
+		case 'h':
+			fprintf( stdout, help_text );
+			exit( 0 );
+			break;
+		case 's':
+			*sock = optarg;
+			break;
+		default:
+			exit_err( help_text );
+			break;
+	}
+}
+
+void read_acl_param( int c, char **sock )
+{
+	read_sock_param( c, sock, acl_help_text );
+}
+
+void read_mirror_param( int c, char **sock, char **ip_addr, char **ip_port )
+{
+	switch( c ){
+		case 'h':
+			fprintf( stdout, mirror_help_text );
+			exit( 0 );
+			break;
+		case 's':
+			*sock = optarg;
+			break;
+		case 'l':
+			*ip_addr = optarg;
+			break;
+		case 'p':
+			*ip_port = optarg;
+			break;
+		default:
+			exit_err( mirror_help_text );
+			break;
+	}
+}
+
+void read_status_param( int c, char **sock )
+{
+	read_sock_param( c, sock, status_help_text );
+}
+
+int mode_serve( int argc, char *argv[] )
+{
+	int c;
+	char *ip_addr = NULL;
+	char *ip_port = NULL;
+	char *file    = NULL;
+	char *sock    = NULL;
+	int err = 0;
+
+	struct mode_serve_params serve;
+
+	while (1) {
+		c = getopt_long(argc, argv, serve_short_options, serve_options, NULL);
+		if ( c == -1 ) break;
+		read_serve_param( c, &ip_addr, &ip_port, &file, &sock );
+	}
+
+	if ( NULL == ip_addr || NULL == ip_port ) {
+		err = 1;
+		fprintf( stderr, "both --addr and --port are required.\n" );
+	}
+	if ( NULL == file ) {
+		err = 1;
+		fprintf( stderr, "--file is required\n" );
+	}
+	if ( err ) { exit_err( serve_help_text ); }
+
+	memset( &serve, 0, sizeof( serve ) );
+	params_serve( &serve, ip_addr, ip_port, file, sock, argc - optind, argv + optind );
+	do_serve( &serve );
+
+	return 0;
+}
+
+int mode_read( int argc, char *argv[] )
+{
+	int c;
+	char *ip_addr = NULL;
+	char *ip_port = NULL;
+	char *from = NULL;
+	char *size = NULL;
+	int err = 0;
+
+	struct mode_readwrite_params readwrite;
+
+	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 ( NULL == ip_addr || NULL == ip_port ) {
+		err = 1;
+		fprintf( stderr, "both --addr and --port are required.\n" );
+	}
+	if ( NULL == from || NULL == size ) {
+		err = 1;
+		fprintf( stderr, "both --from and --size are required.\n" );
+	}
+	if ( err ) { exit_err( read_help_text ); }
+
+	memset( &readwrite, 0, sizeof( readwrite ) );
+	params_readwrite( 0, &readwrite, ip_addr, ip_port, from, size );
+	do_read( &readwrite );
+	return 0;
+}
+
+int mode_write( int argc, char *argv[] )
+{
+	int c;
+	char *ip_addr = NULL;
+	char *ip_port = NULL;
+	char *from = NULL;
+	char *size = NULL;
+	int err = 0;
+
+	struct mode_readwrite_params readwrite;
+
+	while (1){
+		c = getopt_long(argc, argv, write_short_options, write_options, NULL);
+		if ( c == -1 ) break;
+		read_readwrite_param( c, &ip_addr, &ip_port, &from, &size );
+	}
+
+	if ( NULL == ip_addr || NULL == ip_port ) {
+		err = 1;
+		fprintf( stderr, "both --addr and --port are required.\n" );
+	}
+	if ( NULL == from || NULL == size ) {
+		err = 1;
+		fprintf( stderr, "both --from and --size are required.\n" );
+	}
+	if ( err ) { exit_err( write_help_text ); }
+
+	memset( &readwrite, 0, sizeof( readwrite ) );
+	params_readwrite( 1, &readwrite, ip_addr, ip_port, from, size );
+	do_write( &readwrite );
+	return 0;
+}
+
+int mode_acl( int argc, char *argv[] )
+{
+	int c;
+	char *sock = NULL;
+
+	while (1) {
+		c = getopt_long( argc, argv, acl_short_options, acl_options, NULL );
+		if ( c == -1 ) break;
+		read_acl_param( c, &sock );
+	}
+	
+	if ( NULL == sock ){
+		fprintf( stderr, "--sock is required.\n" );
+		exit_err( acl_help_text );
+	}
+
+	/* Don't use the CMD_ACL macro here, "acl" is the remote command
+	 * name, not the cli option
+	 */
+	do_remote_command( "acl", sock, argc - optind, argv + optind );
+
+	return 0;
+}
+
+
+int mode_mirror( int argc, char *argv[] )
+{
+	int c;
+	char *sock = NULL;
+	char *remote_argv[3] = {0};
+	int err = 0;
+
+	while (1) {
+		c = getopt_long( argc, argv, mirror_short_options, mirror_options, NULL);
+		if ( -1 == c ) break;
+		read_mirror_param( c, &sock, &remote_argv[0], &remote_argv[1] );
+	}
+
+	if ( NULL == sock ){
+		fprintf( stderr, "--sock is required.\n" );
+		err = 1;
+	}
+	if ( NULL == remote_argv[0] || NULL == remote_argv[1] ) {
+		fprintf( stderr, "both --addr and --port are required.\n");
+		err = 1;
+	}
+	if ( err ) { exit_err( mirror_help_text ); }
+
+	do_remote_command( "mirror", sock, 2, remote_argv );
+
+	return 0;
+}
+
+
+int mode_status( int argc, char *argv[] )
+{
+	int c;
+	char *sock = NULL;
+	
+	while (1) {
+		c = getopt_long( argc, argv, status_short_options, status_options, NULL );
+		if ( -1 == c ) break;
+		read_status_param( c, &sock );
+	}
+	
+	if ( NULL == sock ){
+		fprintf( stderr, "--sock is required.\n" );
+		exit_err( acl_help_text );
+	}
+
+	do_remote_command( "status", sock, argc - optind, argv + optind );
+
+	return 0;
+}
+
+
+int mode_help( int argc, char *argv[] )
+{
+	char *cmd;
+	char *help_text;
+
+	if ( argc < 1 ){
+		help_text = help_help_text;
+	} else {
+		cmd = argv[0];
+		if (IS_CMD( CMD_SERVE, cmd ) ) {
+			help_text = serve_help_text;
+		} else if ( IS_CMD( CMD_READ, cmd ) ) {
+			help_text = read_help_text;
+		} else if ( IS_CMD( CMD_WRITE, cmd ) ) {
+			help_text = write_help_text;
+		} else if ( IS_CMD( CMD_ACL, cmd ) ) {
+			help_text = acl_help_text;
+		} else if ( IS_CMD( CMD_MIRROR, cmd ) ) {
+			help_text = mirror_help_text;
+		} else if ( IS_CMD( CMD_STATUS, cmd ) ) {
+			help_text = status_help_text;
+		} else { exit_err( help_help_text ); }
+	}
+
+	fprintf( stdout, help_text );
+	return 0;
+}
+
+
+void mode(char* mode, int argc, char **argv)
+{
+	if ( IS_CMD( CMD_SERVE, mode ) ) {
+		mode_serve( argc, argv );
+	}
+	else if ( IS_CMD( CMD_READ, mode ) ) {
+		mode_read( argc, argv );
+	}
+	else if ( IS_CMD( CMD_WRITE, mode ) ) {
+		mode_write( argc, argv );
+	}
+	else if ( IS_CMD( CMD_ACL, mode ) ) {
+		mode_acl( argc, argv );
+	}
+	else if ( IS_CMD( CMD_MIRROR, mode ) ) {
+		mode_mirror( argc, argv );
+	}
+       	else if ( IS_CMD( CMD_STATUS, mode ) ) {
+		mode_status( argc, argv );
+	}
+	else if ( IS_CMD( CMD_HELP, mode ) ) {
+		mode_help( argc-1, argv+1 );
+	}
+	else {
+		mode_help( argc-1, argv+1 );
+		exit( 1 );
+	}
+	exit(0);
+}
+
+
+int main(int argc, char** argv)
+{
+	signal(SIGPIPE, SIG_IGN); /* calls to splice() unhelpfully throw this */
+	error_init();
+
+	if (argc < 2) {
+		exit_err( help_help_text );
+	}
+	mode(argv[1], argc-1, argv+1); /* never returns */
+
+	return 0;
+}
+
diff --git a/ioutil.c b/src/ioutil.c
similarity index 100%
rename from ioutil.c
rename to src/ioutil.c
diff --git a/ioutil.h b/src/ioutil.h
similarity index 100%
rename from ioutil.h
rename to src/ioutil.h
diff --git a/nbdtypes.h b/src/nbdtypes.h
similarity index 100%
rename from nbdtypes.h
rename to src/nbdtypes.h
diff --git a/src/options.h b/src/options.h
new file mode 100644
index 0000000..8c50345
--- /dev/null
+++ b/src/options.h
@@ -0,0 +1,126 @@
+#define GETOPT_ARG(x,s)  {(x), 1, 0, (s)}
+#define GETOPT_FLAG(x,v) {(x), 0, 0, (v)}
+
+#define OPT_HELP "help"
+#define OPT_ADDR "addr"
+#define OPT_PORT "port"
+#define OPT_FILE "file"
+#define OPT_SOCK "sock"
+#define OPT_FROM "from"
+#define OPT_SIZE "size"
+
+#define CMD_SERVE  "serve"
+#define CMD_READ   "read"
+#define CMD_WRITE  "write"
+#define CMD_ACL    "acl"
+#define CMD_MIRROR "mirror"
+#define CMD_STATUS "status"
+#define CMD_HELP   "help"
+#define LEN_CMD_MAX 6
+
+#define PATH_LEN_MAX 1024
+#define ADDR_LEN_MAX 64
+
+
+#define IS_CMD(x,c) (strncmp((x),(c),(LEN_CMD_MAX)) == 0)
+
+static struct option serve_options[] = {
+	GETOPT_FLAG( OPT_HELP, 'h' ),
+	GETOPT_ARG( OPT_ADDR, 'l' ),
+	GETOPT_ARG( OPT_PORT, 'p' ),
+	GETOPT_ARG( OPT_FILE, 'f' ),
+	GETOPT_ARG( OPT_SOCK, 's' ),
+	{0}
+};
+static char serve_short_options[] = "hl: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"
+	"\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_SOCK ",-s <SOCK>\tPath to the control socket to open.\n";
+
+static struct option read_options[] = {
+	GETOPT_FLAG( OPT_HELP, 'h' ),
+	GETOPT_ARG( OPT_ADDR, 'l' ),
+	GETOPT_ARG( OPT_PORT, 'p' ),
+	GETOPT_ARG( OPT_FROM, 'F' ),
+	GETOPT_ARG( OPT_SIZE, 'S' ),
+  	{0}
+};
+static char read_short_options[] = "hl:p:F:S:";
+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"
+	"\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";
+
+
+static struct option *write_options = read_options;
+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"
+	"\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";
+
+struct option acl_options[] = {
+	GETOPT_FLAG( OPT_HELP, 'h' ),
+	GETOPT_ARG( OPT_SOCK, 's' ),
+	{0}
+};
+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"
+	"\t--" OPT_SOCK ",-s <SOCK>\tPath to the control socket.\n";
+
+struct option mirror_options[] = {
+	GETOPT_FLAG( OPT_HELP, 'h' ),
+	GETOPT_ARG( OPT_SOCK, 's' ),
+	GETOPT_ARG( OPT_ADDR, 'l' ),
+	GETOPT_ARG( OPT_PORT, 'p' ),
+	{0}
+};
+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"
+	"\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";
+	
+
+struct option status_options[] = {
+	GETOPT_FLAG( OPT_HELP, 'h' ),
+	GETOPT_ARG( OPT_SOCK, 's' ),	
+	{0}
+};
+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"
+	"\t--" OPT_SOCK ",-s <SOCK>\tPath to the control socket.\n";
+
+static char help_help_text[] = 
+	"Usage: flexnbd <cmd> [cmd options]\n\n"
+	"Commands:\n"
+	"\tflexnbd serve\n"
+	"\tflexnbd read\n"
+	"\tflexnbd write\n"
+	"\tflexnbd acl\n"
+	"\tflexnbd mirror\n"
+	"\tflexnbd status\n"
+	"\tflexnbd help\n\n"
+	"See flexnbd help <cmd> for further info\n";
diff --git a/params.h b/src/params.h
similarity index 100%
rename from params.h
rename to src/params.h
diff --git a/parse.c b/src/parse.c
similarity index 100%
rename from parse.c
rename to src/parse.c
diff --git a/parse.h b/src/parse.h
similarity index 100%
rename from parse.h
rename to src/parse.h
diff --git a/readwrite.c b/src/readwrite.c
similarity index 100%
rename from readwrite.c
rename to src/readwrite.c
diff --git a/readwrite.h b/src/readwrite.h
similarity index 100%
rename from readwrite.h
rename to src/readwrite.h
diff --git a/remote.c b/src/remote.c
similarity index 100%
rename from remote.c
rename to src/remote.c
diff --git a/serve.c b/src/serve.c
similarity index 100%
rename from serve.c
rename to src/serve.c
diff --git a/util.c b/src/util.c
similarity index 100%
rename from util.c
rename to src/util.c
diff --git a/util.h b/src/util.h
similarity index 100%
rename from util.h
rename to src/util.h
diff --git a/tests/flexnbd.rb b/tests/flexnbd.rb
index 2253f9f..49224c9 100644
--- a/tests/flexnbd.rb
+++ b/tests/flexnbd.rb
@@ -16,7 +16,13 @@ class FlexNBD
   def serve(ip, port, file, *acl)
     File.unlink(ctrl) if File.exists?(ctrl)
     @pid = fork do
-      exec("#{@bin} serve #{ip} #{port} #{file} #{ctrl} #{acl.join(' ')}")
+      cmd ="#{@bin} serve "\
+           "--addr #{ip} "\
+           "--port #{port} "\
+           "--file #{file} "\
+           "--sock #{ctrl} "\
+           "#{acl.join(' ')}"
+      exec(cmd)
     end
     sleep 0.1 until File.socket?(ctrl)
   end
@@ -27,14 +33,22 @@ class FlexNBD
   end
   
   def read(offset, length)
-    IO.popen("#{@bin} read #{ip} #{port} #{offset} #{length}","r") do |fh|
+    IO.popen("#{@bin} read "\
+             "--addr #{ip} "\
+             "--port #{port} "\
+             "--from #{offset} "\
+             "--size #{length}","r") do |fh|
       return fh.read
     end
     raise "read failed" unless $?.success?
   end
   
   def write(offset, data)
-    IO.popen("#{@bin} write #{ip} #{port} #{offset} #{data.length}","w") do |fh|
+    IO.popen("#{@bin} write "\
+             "--addr #{ip} "\
+             "--port #{port} "\
+             "--from #{offset} "\
+             "--size #{data.length}","w") do |fh|
       fh.write(data)
     end
     raise "write failed" unless $?.success?
diff --git a/tests/nbd_scenarios b/tests/nbd_scenarios
index faa4767..7392112 100644
--- a/tests/nbd_scenarios
+++ b/tests/nbd_scenarios
@@ -13,39 +13,39 @@ class NBDScenarios < Test::Unit::TestCase
     @available_ports = [*40000..41000] - listening_ports
     @port1 = @available_ports.shift
     @port2 = @available_ports.shift
-    @nbd1 = FlexNBD.new("../flexnbd", @ip, @port1)
-  end 
-  
+    @nbd1 = FlexNBD.new("../build/flexnbd", @ip, @port1)
+  end
+
   def teardown
     @nbd1.kill rescue nil
     [@filename1, @filename2].each do |f|
       File.unlink(f) if File.exists?(f)
     end
   end
-  
+
   def test_read1
     writefile1("f"*64)
     serve1
-    
+
     [0, 12, 63].each do |num|
-    
+
       assert_equal(
-        @nbd1.read(num*@blocksize, @blocksize), 
+        @nbd1.read(num*@blocksize, @blocksize),
         @file1.read(num*@blocksize, @blocksize)
       )
     end
-    
+
     [124, 1200, 10028, 25488].each do |num|
       assert_equal(@nbd1.read(num, 4), @file1.read(num, 4))
     end
   end
-  
-  # Check that we're not 
+
+  # Check that we're not
   #
   def test_writeread1
     writefile1("0"*64)
     serve1
-    
+
     [0, 12, 63].each do |num|
       data = "X"*@blocksize
       @nbd1.write(num*@blocksize, data)
@@ -53,14 +53,14 @@ class NBDScenarios < Test::Unit::TestCase
       assert_equal(data, @nbd1.read(num*@blocksize, data.size))
     end
   end
-  
+
   # Check that we're not overstepping or understepping where our writes end
   # up.
   #
   def test_writeread2
     writefile1("0"*1024)
     serve1
-    
+
     d0 = "\0"*@blocksize
     d1 = "X"*@blocksize
     (0..63).each do |num|
@@ -70,16 +70,16 @@ class NBDScenarios < Test::Unit::TestCase
       assert_equal(d0, @nbd1.read(((2*num)+1)*@blocksize, d0.size))
     end
   end
-  
+
   protected
   def serve1(*acl)
     @nbd1.serve(@ip, @port1, @filename1, *acl)
   end
-  
+
   def writefile1(data)
     @file1 = TestFileWriter.new(@filename1, @blocksize).write(data)
   end
-  
+
   def listening_ports
     `netstat -ltn`.
       split("\n").