[SERVER] Add list of trusted servers and namespaces (load, display)

10 files changed, 310 insertions, 71 deletions

diff --git a/src/config.h b/src/config.h
index ff638d2..2f348aa 100644
--- a/src/config.h
+++ b/src/config.h
@@ -63,7 +63,7 @@
 #define KERNEL_SECTOR_SIZE 512
 #define DNBD3_BLOCK_SIZE 4096
 #define NUMBER_DEVICES 8
-#define DEFAULT_READ_AHEAD_KB 256
+#define DEFAULT_READ_AHEAD_KB 512
 
 // +++++ Misc +++++
 #define DEFAULT_SERVER_CONFIG_FILE "/etc/dnbd3/server.conf"
diff --git a/src/kernel/net.c b/src/kernel/net.c
index 57279d6..b116ad6 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -124,6 +124,8 @@ int dnbd3_net_connect(dnbd3_device_t *dev)
 
     struct timeval timeout;
 
+    char get_servers = 0, set_client = 0;
+
     timeout.tv_sec = SOCKET_TIMEOUT_CLIENT_DATA;
     timeout.tv_usec = 0;
 
@@ -136,11 +138,21 @@ int dnbd3_net_connect(dnbd3_device_t *dev)
     	memcpy(dev->alt_servers, &dev->initial_server, sizeof(dev->alt_servers[0]));
     	if (!dev->is_server)
     	{
-			req1 = kmalloc(sizeof(*req1), GFP_ATOMIC);
-			if (!req1)
-				error_dev("FATAL: Kmalloc(1) failed.");
+    		get_servers = 1;
     	}
     }
+    if (dev->better_sock)
+    {
+   	 set_client = 1;
+    }
+
+    if (get_servers || set_client)
+    {
+		req1 = kmalloc(sizeof(*req1), GFP_ATOMIC);
+		if (!req1)
+			error_dev("FATAL: Kmalloc(1) failed.");
+    }
+
     if (dev->cur_server.port == 0 || dev->cur_server.hostaddrtype == 0 || dev->imgname == NULL)
     	error_dev("FATAL: Host, port or image name not set.");
     if (dev->sock)
@@ -224,6 +236,7 @@ int dnbd3_net_connect(dnbd3_device_t *dev)
         // store image information
         set_capacity(dev->disk, dev->reported_size >> 9); /* 512 Byte blocks */
         debug_dev_va("INFO: Filesize: %llu.", dev->reported_size);
+        dev->update_available = 0;
     }
     else // Switching server, connection is already established and size request was executed
     {
@@ -236,15 +249,20 @@ int dnbd3_net_connect(dnbd3_device_t *dev)
 
     dev->panic = 0;
     dev->panic_count = 0;
-    dev->update_available = 0;
 
-    if (req1) // This connection is established to the initial server (from the ioctl call)
+    if (get_servers) // This connection is established to the initial server (from the ioctl call)
     {
 		// Enqueue request to request_queue_send for a fresh list of alt servers
 		req1->cmd_type = REQ_TYPE_SPECIAL;
 		req1->cmd_flags = CMD_GET_SERVERS;
 		list_add(&req1->queuelist, &dev->request_queue_send);
     }
+    else if (set_client)
+    {
+ 		req1->cmd_type = REQ_TYPE_SPECIAL;
+ 		req1->cmd_flags = CMD_SET_CLIENT_MODE;
+ 		list_add(&req1->queuelist, &dev->request_queue_send);
+    }
 
     // create required threads
     dev->thread_send = kthread_create(dnbd3_net_send, dev, dev->disk->disk_name);
diff --git a/src/server/ipc.c b/src/server/ipc.c
index 37ca36f..e988abc 100644
--- a/src/server/ipc.c
+++ b/src/server/ipc.c
@@ -361,7 +361,7 @@ static int recv_data(int client_sock, void *buffer_out, int len)
  */
 static int ipc_receive(int client_sock)
 {
-	GSList *iterator = NULL;
+	GSList *iterator, *iterator2;
 
 	struct tm *timeinfo;
 #define STRBUFLEN 100
@@ -374,7 +374,7 @@ static int ipc_receive(int client_sock)
 	int ret, locked;
 	int return_value = 0;
 	xmlDocPtr docReply = NULL, docRequest = NULL;
-	xmlNodePtr root_node, images_node, clients_node, tmp_node, log_parent_node, log_node;
+	xmlNodePtr root_node, parent_node, tmp_node, log_parent_node, log_node, server_node;
 	xmlChar *xmlbuff;
 	int buffersize;
 
@@ -420,10 +420,10 @@ static int ipc_receive(int client_sock)
 		xmlDocSetRootElement(docReply, root_node);
 
 		// Images
-		images_node = xmlNewNode(NULL, BAD_CAST "images");
-		if (images_node == NULL)
+		parent_node = xmlNewNode(NULL, BAD_CAST "images");
+		if (parent_node == NULL)
 			goto get_info_reply_cleanup;
-		xmlAddChild(root_node, images_node);
+		xmlAddChild(root_node, parent_node);
 		locked = 1;
 		pthread_spin_lock(&_spinlock);
 		for (iterator = _dnbd3_images; iterator; iterator = iterator->next)
@@ -450,13 +450,18 @@ static int ipc_receive(int client_sock)
 				sprintf(strbuffer, "%d", complete / size);
 				xmlNewProp(tmp_node, BAD_CAST "cachefill", BAD_CAST image->cache_file);
 			}
-			xmlAddChild(images_node, tmp_node);
+			xmlAddChild(parent_node, tmp_node);
 		}
+		pthread_spin_unlock(&_spinlock);
+		locked = 0;
+
 		// Clients
-		clients_node = xmlNewNode(NULL, BAD_CAST "clients");
-		if (clients_node == NULL)
+		parent_node = xmlNewNode(NULL, BAD_CAST "clients");
+		if (parent_node == NULL)
 			goto get_info_reply_cleanup;
-		xmlAddChild(root_node, clients_node);
+		xmlAddChild(root_node, parent_node);
+		locked = 1;
+		pthread_spin_lock(&_spinlock);
 		for (iterator = _dnbd3_clients; iterator; iterator = iterator->next)
 		{
 			dnbd3_client_t *client = iterator->data;
@@ -469,7 +474,48 @@ static int ipc_receive(int client_sock)
 				inet_ntop(client->addrtype, client->ipaddr, strbuffer, STRBUFLEN);
 				xmlNewProp(tmp_node, BAD_CAST "ip", BAD_CAST strbuffer);
 				xmlNewProp(tmp_node, BAD_CAST "file", BAD_CAST client->image->file);
-				xmlAddChild(clients_node, tmp_node);
+				xmlAddChild(parent_node, tmp_node);
+			}
+		}
+		pthread_spin_unlock(&_spinlock);
+		locked = 0;
+
+		// Trusted servers
+		parent_node = xmlNewNode(NULL, BAD_CAST "trusted");
+		if (parent_node == NULL)
+			goto get_info_reply_cleanup;
+		xmlAddChild(root_node, parent_node);
+		locked = 1;
+		pthread_spin_lock(&_spinlock);
+		for (iterator = _trusted_servers; iterator; iterator = iterator->next)
+		{
+			dnbd3_trusted_server_t *server = iterator->data;
+			if (server->hostaddrtype != 0)
+			{
+				tmp_node = xmlNewNode(NULL, BAD_CAST "server");
+				if (tmp_node == NULL)
+					goto get_info_reply_cleanup;
+				*strbuffer = '\0';
+				inet_ntop(server->hostaddrtype, server->hostaddr, strbuffer, STRBUFLEN);
+				xmlNewProp(tmp_node, BAD_CAST "ip", BAD_CAST strbuffer);
+				sprintf(strbuffer, "%d", (int)server->port);
+				xmlNewProp(tmp_node, BAD_CAST "port", BAD_CAST strbuffer);
+				if (server->comment)
+					xmlNewProp(tmp_node, BAD_CAST "comment", BAD_CAST server->comment);
+				for (iterator2 = server->namespaces; iterator2; iterator2 = iterator2->next)
+				{
+					const dnbd3_namespace_t *ns = iterator2->data;
+					server_node = xmlNewNode(NULL, BAD_CAST "namespace");
+					if (server_node == NULL)
+						goto get_info_reply_cleanup;
+					xmlAddChild(tmp_node, server_node);
+					xmlNewProp(server_node, BAD_CAST "name", BAD_CAST ns->name);
+					if (ns->auto_replicate)
+						xmlNewProp(server_node, BAD_CAST "replicate", BAD_CAST "1");
+					if (ns->recursive)
+						xmlNewProp(server_node, BAD_CAST "recursive", BAD_CAST "1");
+				}
+				xmlAddChild(parent_node, tmp_node);
 			}
 		}
 		pthread_spin_unlock(&_spinlock);
@@ -656,7 +702,7 @@ void dnbd3_ipc_send(int cmd)
 		{
 			int count;
 			int term_width = get_terminal_width();
-			xmlNodePtr cur;
+			xmlNodePtr cur, childit;
 
 			// Print log
 			xmlChar *log = getTextFromPath(doc, "/data/log");
@@ -668,16 +714,15 @@ void dnbd3_ipc_send(int cmd)
 			int watime = 0, wname = 0, wrid = 5;
 			FOR_EACH_NODE(doc, "/data/images/image", cur)
 			{
-				if (cur->type == XML_ELEMENT_NODE)
-				{
-					xmlChar *atime = xmlGetNoNsProp(cur, BAD_CAST "atime");
-					xmlChar *vid = xmlGetNoNsProp(cur, BAD_CAST "name");
-					xmlChar *rid = xmlGetNoNsProp(cur, BAD_CAST "rid");
-					watime = MAX(watime, xmlStrlen(atime));
-					wname = MAX(wname, xmlStrlen(vid));
-					wrid = MAX(wrid, xmlStrlen(rid));
-					// Too lazy to free vars, client will exit anyways
-				}
+				if (cur->type != XML_ELEMENT_NODE)
+					continue;
+				xmlChar *atime = xmlGetNoNsProp(cur, BAD_CAST "atime");
+				xmlChar *vid = xmlGetNoNsProp(cur, BAD_CAST "name");
+				xmlChar *rid = xmlGetNoNsProp(cur, BAD_CAST "rid");
+				watime = MAX(watime, xmlStrlen(atime));
+				wname = MAX(wname, xmlStrlen(vid));
+				wrid = MAX(wrid, xmlStrlen(rid));
+				// Too lazy to free vars, client will exit anyways
 			} END_FOR_EACH;
 
 			char format[100];
@@ -691,16 +736,15 @@ void dnbd3_ipc_send(int cmd)
 			count = 0;
 			FOR_EACH_NODE(doc, "/data/images/image", cur)
 			{
-				if (cur->type == XML_ELEMENT_NODE)
-				{
-					++count;
-					xmlChar *atime = xmlGetNoNsProp(cur, BAD_CAST "atime");
-					xmlChar *vid = xmlGetNoNsProp(cur, BAD_CAST "name");
-					xmlChar *rid = xmlGetNoNsProp(cur, BAD_CAST "rid");
-					xmlChar *file = xmlGetNoNsProp(cur, BAD_CAST "file");
-					printf(format, atime, vid, rid, file);
-					// Too lazy to free vars, client will exit anyways
-				}
+				if (cur->type != XML_ELEMENT_NODE)
+					continue;
+				++count;
+				xmlChar *atime = xmlGetNoNsProp(cur, BAD_CAST "atime");
+				xmlChar *vid = xmlGetNoNsProp(cur, BAD_CAST "name");
+				xmlChar *rid = xmlGetNoNsProp(cur, BAD_CAST "rid");
+				xmlChar *file = xmlGetNoNsProp(cur, BAD_CAST "file");
+				printf(format, atime, vid, rid, file);
+				// Too lazy to free vars, client will exit anyways
 			} END_FOR_EACH;
 			char_repeat_br('=', term_width);
 			printf("\nNumber of images: %d\n\n", count);
@@ -711,17 +755,50 @@ void dnbd3_ipc_send(int cmd)
 			count = 0;
 			FOR_EACH_NODE(doc, "/data/clients/client", cur)
 			{
-				if (cur->type == XML_ELEMENT_NODE)
+				if (cur->type != XML_ELEMENT_NODE)
+					continue;
+				++count;
+				xmlChar *ip = xmlGetNoNsProp(cur, BAD_CAST "ip");
+				xmlChar *file = xmlGetNoNsProp(cur, BAD_CAST "file");
+				printf("%-40s %s\n", ip, file);
+				// Too lazy to free vars, client will exit anyways
+			} END_FOR_EACH;
+			char_repeat_br('=', term_width);
+			printf("\nNumber clients: %d\n\n", count);
+
+			// Print trusted servers
+			printf("Trusted servers:\n");
+			char_repeat_br('=', term_width);
+			count = 0;
+			FOR_EACH_NODE(doc, "/data/trusted/server", cur)
+			{
+				if (cur->type != XML_ELEMENT_NODE)
+					continue;
+				++count;
+				xmlChar *ip = xmlGetNoNsProp(cur, BAD_CAST "ip");
+				xmlChar *comment = xmlGetNoNsProp(cur, BAD_CAST "comment");
+				if (comment)
+					printf("%-30s (%s)\n", ip, comment);
+				else
+					printf("%-30s\n", ip);
+				for (childit = cur->children; childit; childit = childit->next)
 				{
-					++count;
-					xmlChar *ip = xmlGetNoNsProp(cur, BAD_CAST "ip");
-					xmlChar *file = xmlGetNoNsProp(cur, BAD_CAST "file");
-					printf("%-40s %s\n", ip, file);
-					// Too lazy to free vars, client will exit anyways
+					if (childit->type != XML_ELEMENT_NODE || childit->name == NULL || strcmp(childit->name, "namespace") != 0)
+						continue;
+					xmlChar *name = xmlGetNoNsProp(childit, BAD_CAST "name");
+					xmlChar *replicate = xmlGetNoNsProp(childit, BAD_CAST "replicate");
+					xmlChar *recursive = xmlGetNoNsProp(childit, BAD_CAST "recursive");
+					printf("     %-40s ", name);
+					if (replicate && *replicate != '0')
+						printf(" replicate");
+					if (recursive && *recursive != '0')
+						printf(" recursive");
+					putchar('\n');
 				}
+				// Too lazy to free vars, client will exit anyways
 			} END_FOR_EACH;
 			char_repeat_br('=', term_width);
-			printf("\nNumber clients: %d\n\n", count);
+			printf("\nNumber servers: %d\n\n", count);
 
 			// Cleanup
 			xmlFreeDoc(doc);
diff --git a/src/server/job.c b/src/server/job.c
index 8753c2c..b50a7f3 100644
--- a/src/server/job.c
+++ b/src/server/job.c
@@ -1,10 +1,13 @@
 #include "job.h"
+#include "utils.h"
 #include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
 #include <pthread.h>
+#include <sys/socket.h>
+#include <glib/gslist.h>
 
 #define DEV_STRLEN 12 // INCLUDING NULLCHAR (increase to 13 if you need more than 100 (0-99) devices)
 #define MAX_NUM_DEVICES_TO_CHECK 100
@@ -26,10 +29,13 @@ typedef struct
 // "/dev/dnbdXX" == 11 bytes per device + nullchar = 12
 static device_t *devices = NULL;
 static int num_devices = 0;
-
 static char keep_running = TRUE;
 
+// Private functions
 static char* get_free_device();
+static void query_servers();
+
+//
 
 void* dnbd3_job_thread(void *data)
 {
@@ -38,7 +44,7 @@ void* dnbd3_job_thread(void *data)
 	char dev[DEV_STRLEN];
 	for (i = 0; i < MAX_NUM_DEVICES_TO_CHECK; ++i)
 	{
-		sprintf(dev, "/dev/dnbd%d", i);
+		snprintf(dev, DEV_STRLEN, "/dev/dnbd%d", i);
 		if (access(dev, W_OK | R_OK)) // Need RW access to device to read and do ioctl
 			continue;
 		++num_devices;
@@ -49,7 +55,7 @@ void* dnbd3_job_thread(void *data)
 		for (i = 0, j = 0; i < MAX_NUM_DEVICES_TO_CHECK; ++i)
 		{
 			memset(dev, 0, DEV_STRLEN);
-			sprintf(dev, "/dev/dnbd%d", i);
+			snprintf(dev, DEV_STRLEN, "/dev/dnbd%d", i);
 			if (access(dev, W_OK | R_OK))
 				continue;
 			if (j >= num_devices) // More available devices during second iteration? :-(
@@ -60,14 +66,26 @@ void* dnbd3_job_thread(void *data)
 		}
 	}
 	//
+	time_t next_delete_invocation = 0;
+	//
 	// Job/Watchdog mainloop
 	while (keep_running)
 	{
+		const time_t starttime = time(NULL);
+		//
 		// TODO: Update image atime
-		// TODO: Handle image deletion
+      // Call image deletion function if last call is more than 5 minutes ago
+      if (starttime < next_delete_invocation)
+      {
+    	  next_delete_invocation = starttime + 300;
+    	  dnbd3_exec_delete(TRUE);
+      }
 		// TODO: Replicate proxied images (limited bandwidth)
-		// TODO: Query other servers for new images/status/...
+		// Query other servers for new images/status/...
+      query_servers();
 		// TODO: Switch server of dnbd device based on more sophisticated inputs than just rtt
+      // Calc sleep timeout for next iteration
+      sleep(30 - (time(NULL) - starttime)); // Sleep 30 seconds, but account for the time it took to execute the loop
 	}
 	//
 	free(devices);
@@ -81,6 +99,17 @@ void dnbd3_job_shutdown()
 	keep_running = FALSE;
 }
 
+static void query_servers()
+{
+	struct timeval client_timeout;
+	client_timeout.tv_sec = 0;
+	client_timeout.tv_usec = 500 * 1000;
+	int client_sock;
+	// Apply read/write timeout
+	setsockopt(client_sock, SOL_SOCKET, SO_RCVTIMEO, &client_timeout, sizeof(client_timeout));
+	setsockopt(client_sock, SOL_SOCKET, SO_SNDTIMEO, &client_timeout, sizeof(client_timeout));
+}
+
 /**
  * Get full name of an available dnbd3 device, eg. /dev/dnbd4
  * Returned buffer is owned by this module, do not modify or free!
diff --git a/src/server/net.c b/src/server/net.c
index b953e13..bcbf056 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -361,6 +361,7 @@ void *dnbd3_handle_query(void *dnbd3_client)
 
 
         case CMD_GET_SERVERS:
+      	  client->is_server = FALSE; // Only clients request list of servers
             // Build list of known working alt servers
             num = 0;
             for (i = 0; i < NUMBER_SERVERS; i++)
@@ -379,6 +380,10 @@ void *dnbd3_handle_query(void *dnbd3_client)
         	send_reply(client->sock, &reply, NULL);
         	break;
 
+        case CMD_SET_CLIENT_MODE:
+      	  client->is_server = FALSE;
+      	  break;
+
         default:
         	memlogf("ERROR: Unknown command\n");
             break;
diff --git a/src/server/server.c b/src/server/server.c
index 1ca55fa..feee30b 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -47,6 +47,7 @@ char *_config_file_name = DEFAULT_SERVER_CONFIG_FILE;
 char *_local_namespace = NULL;
 char *_ipc_password = NULL;
 GSList *_dnbd3_images = NULL; // of dnbd3_image_t
+GSList *_trusted_servers = NULL;
 
 void dnbd3_print_help(char* argv_0)
 {
@@ -211,7 +212,6 @@ int main(int argc, char* argv[])
     struct sockaddr_in client;
     unsigned int len = sizeof(client);
     int fd;
-    time_t next_delete_invocation = 0;
     struct timeval timeout;
     timeout.tv_sec = SOCKET_TIMEOUT_SERVER;
     timeout.tv_usec = 0;
@@ -267,13 +267,6 @@ int main(int argc, char* argv[])
         	continue;
         }
         pthread_detach(dnbd3_client->thread);
-        // Call image deletion function if last call is more than 5 minutes ago
-        const time_t now = time(NULL);
-        if (now < next_delete_invocation)
-        {
-      	  next_delete_invocation = now + 300;
-      	  dnbd3_exec_delete(TRUE);
-        }
     }
 
     dnbd3_cleanup();
diff --git a/src/server/server.h b/src/server/server.h
index 832777e..1e17048 100644
--- a/src/server/server.h
+++ b/src/server/server.h
@@ -64,10 +64,27 @@ typedef struct
     dnbd3_image_t *image;
 } dnbd3_client_t;
 
+typedef struct
+{
+	uint8_t  hostaddr[16];
+	uint16_t port;
+	uint8_t  hostaddrtype;
+	gchar    *comment;
+	GSList   *namespaces; // List of dnbd3_namespace_t
+} dnbd3_trusted_server_t;
+
+typedef struct
+{
+	char     *name;
+	uint8_t  auto_replicate;
+	uint8_t  recursive;
+} dnbd3_namespace_t;
+
 extern GSList *_dnbd3_clients; // of dnbd3_client_t
 extern pthread_spinlock_t _spinlock;
 extern char *_config_file_name, *_local_namespace, *_ipc_password;
 extern GSList *_dnbd3_images; // of dnbd3_image_t
+extern GSList *_trusted_servers;
 
 
 #ifdef _DEBUG
diff --git a/src/server/utils.c b/src/server/utils.c
index 391992d..dc3d6c4 100644
--- a/src/server/utils.c
+++ b/src/server/utils.c
@@ -120,7 +120,8 @@ static char is_valid_namespace(char *namespace)
 	while (*namespace)
 	{
 		if (*namespace != '/' && *namespace != '-' && (*namespace < 'a' || *namespace > 'z')
-		   && (*namespace < 'A' || *namespace > 'Z'))
+		   && (*namespace < 'A' || *namespace > 'Z')
+		   && (*namespace < '0' || *namespace > '9'))
 			return 0;
 		++namespace;
 	}
@@ -135,8 +136,10 @@ static char is_valid_imagename(char *namespace)
 		return 0; // Invalid: Length = 0 or starting with a space
 	while (*namespace)
 	{	// Check for invalid chars
-		if (*namespace != '.' && *namespace != '-' && *namespace != ' ' && *namespace != '(' && *namespace != ')'
-		   && (*namespace < 'a' || *namespace > 'z') && (*namespace < 'A' || *namespace > 'Z'))
+		if (*namespace != '.' && *namespace != '-' && *namespace != ' '
+			&& *namespace != '(' && *namespace != ')'
+		   && (*namespace < 'a' || *namespace > 'z') && (*namespace < 'A' || *namespace > 'Z')
+		   && (*namespace < '0' || *namespace > '9'))
 			return 0;
 		++namespace;
 	}
@@ -145,6 +148,13 @@ static char is_valid_imagename(char *namespace)
 	return 1;
 }
 
+static inline int is_same_server(const dnbd3_trusted_server_t * const a, const dnbd3_trusted_server_t * const b)
+{
+	return (a->hostaddrtype == b->hostaddrtype)
+		&& (a->port == b->port)
+		&& (0 == memcmp(a->hostaddr, b->hostaddr, (a->hostaddrtype == AF_INET ? 4 : 16)));
+}
+
 static void strtolower(char *string)
 {
 	while (*string)
@@ -157,7 +167,7 @@ static void strtolower(char *string)
 
 void dnbd3_load_config()
 {
-	gint i;
+	gint i, j;
 
 	if (_config_handle != NULL)
 	{
@@ -188,9 +198,32 @@ void dnbd3_load_config()
 
 	for (i = 0; i < section_count; i++)
 	{
-		// Special group, ignore
-		if (strcmp(groups[i], "settings") == 0 || strcmp(groups[i], "trusted") == 0)
+		// Ignore settings section
+		if (strcmp(groups[i], "settings") == 0)
+			continue;
+
+		// List of trusted servers/namespaces
+		if (strncmp(groups[i], "trust:", 6) == 0)
 		{
+			gchar *addr = g_key_file_get_string(_config_handle, groups[i], "address", NULL);
+			if (addr == NULL)
+				continue;
+			dnbd3_trusted_server_t *server = dnbd3_get_trusted_server(addr, TRUE);
+			g_free(addr);
+			if (server == NULL)
+				continue;
+			server->comment = strdup(groups[i]+6);
+			gsize key_count;
+			gchar **keys = g_key_file_get_keys(_config_handle, groups[i], &key_count, NULL);
+			for (j = 0; j < key_count; ++j)
+			{
+				if (strcmp(keys[j], "address") == 0)
+					continue;
+				char *flags = g_key_file_get_string(_config_handle, groups[i], keys[j], NULL);
+				dnbd3_add_trusted_namespace(server, keys[j], flags);
+				g_free(flags);
+			}
+			g_strfreev(keys);
 			continue;
 		}
 
@@ -216,13 +249,11 @@ void dnbd3_load_config()
 		gsize num_servers;
 		gchar **servers = g_key_file_get_string_list(_config_handle, groups[i], "servers", &num_servers, NULL);
 
-		pthread_spin_lock(&_spinlock);
 		dnbd3_image_t *image = prepare_image(groups[i], rid, image_file, cache_file, servers, num_servers);
 		if (image)
 		{
 			_dnbd3_images = g_slist_prepend(_dnbd3_images, image);
 		}
-		pthread_spin_unlock(&_spinlock);
 
 		g_free(image_file);
 		g_free(cache_file);
@@ -651,6 +682,70 @@ void dnbd3_exec_delete(int save_if_changed)
 }
 
 /**
+ * Return pointer to trusted_server matching given address.
+ * If not found and create_if_not_found is TRUE, a new entry will be created,
+ * added to the list and then returned
+ * Returns NULL otherwise, or if the address could not be parsed
+ * !! Lock before calling this function !!
+ */
+dnbd3_trusted_server_t *dnbd3_get_trusted_server(char *address, char create_if_not_found)
+{
+	dnbd3_trusted_server_t server;
+	memset(&server, 0, sizeof(server));
+	if (!parse_address(address, &server.hostaddrtype, server.hostaddr, &server.port))
+	{
+		memlogf("[WARNING] Could not parse address '%s' of trusted server", address);
+		return NULL;
+	}
+	GSList *iterator;
+	for (iterator = _trusted_servers; iterator; iterator = iterator->next)
+	{
+		dnbd3_trusted_server_t *comp = iterator->data;
+		if (is_same_server(comp, &server))
+			return comp;
+	}
+	if (!create_if_not_found)
+		return NULL;
+	dnbd3_trusted_server_t *copy = malloc(sizeof(server));
+	memcpy(copy, &server, sizeof(*copy));
+	_trusted_servers = g_slist_prepend(_trusted_servers, copy);
+	return copy;
+}
+
+/**
+ * Add new trusted namespace to given trusted server, using given flags.
+ * Overwrites any existing entry for the given server and namespace
+ * !! Lock before calling this function !!
+ */
+int dnbd3_add_trusted_namespace(dnbd3_trusted_server_t *server, char *namespace, char *flags)
+{
+	int nslen = strlen(namespace) + 1;
+	char nslow[nslen];
+	memcpy(nslow, namespace, nslen);
+	strtolower(nslow);
+	GSList *iterator;
+	dnbd3_namespace_t *ns = NULL;
+	for (iterator = server->namespaces; iterator; iterator = iterator->next)
+	{
+		dnbd3_namespace_t *cmp = iterator->data;
+		if (strcmp(nslow, cmp->name) == 0)
+		{
+			ns = cmp;
+			break;
+		}
+	}
+	if (ns == NULL)
+	{
+		ns = calloc(1, sizeof(*ns));
+		ns->name = strdup(nslow);
+		server->namespaces = g_slist_prepend(server->namespaces, ns);
+	}
+	ns->auto_replicate = (flags && strstr(flags, "replicate"));
+	ns->recursive = (flags && strstr(flags, "recursive"));
+	return TRUE;
+}
+
+/**
  * Return local image name for a global image name
  * eg. "uni-freiburg/rz/ubuntu 12.04" -> "ubuntu 12.04"
  * ONLY IF the local name space really is "uni-freiburg/rz"
diff --git a/src/server/utils.h b/src/server/utils.h
index e923f82..53dc076 100644
--- a/src/server/utils.h
+++ b/src/server/utils.h
@@ -21,6 +21,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 
+#include "server.h"
 #include "../config.h"
 
 #ifndef UTILS_H_
@@ -48,6 +49,9 @@ void dnbd3_exec_delete(int save_if_changed);
 
 dnbd3_image_t* dnbd3_get_image(char *name, int rid, const char do_lock);
 
+dnbd3_trusted_server_t *dnbd3_get_trusted_server(char *address, char create_if_not_found);
+int dnbd3_add_trusted_namespace(dnbd3_trusted_server_t *server, char *namespace, char *flags);
+
 void dnbd3_handle_sigpipe(int signum);
 void dnbd3_handle_sigterm(int signum);
 
diff --git a/src/types.h b/src/types.h
index ab3a2f0..72449da 100644
--- a/src/types.h
+++ b/src/types.h
@@ -74,12 +74,13 @@ typedef struct
 } dnbd3_ioctl_t;
 
 // network
-#define CMD_GET_BLOCK   1
-#define CMD_GET_SIZE    2
-#define CMD_GET_SERVERS 3
-#define CMD_ERROR		4
-#define CMD_KEEPALIVE	5
-#define CMD_LATEST_RID	6
+#define CMD_GET_BLOCK           1
+#define CMD_GET_SIZE            2
+#define CMD_GET_SERVERS         3
+#define CMD_ERROR               4
+#define CMD_KEEPALIVE           5
+#define CMD_LATEST_RID          6
+#define CMD_SET_CLIENT_MODE     7
 
 #pragma pack(1)
 typedef struct