[SERVER] Automatically add and remove alt servers from images depending on wehter the other server is reachable

[SERVER] Automatically replicate images from other servers

6 files changed, 187 insertions, 36 deletions

diff --git a/src/server/ipc.c b/src/server/ipc.c
index 0dbf46f..c59aa6b 100644
--- a/src/server/ipc.c
+++ b/src/server/ipc.c
@@ -359,7 +359,7 @@ static int ipc_receive(int client_sock)
 			goto get_info_reply_cleanup;
 		xmlDocSetRootElement(docReply, root_node);
 
-		xmlNewChild(root_node, NULL, BAD_CAST "namespace", BAD_CAST _local_namespace);
+		xmlNewTextChild(root_node, NULL, BAD_CAST "namespace", BAD_CAST _local_namespace);
 
 		// Images
 		parent_node = xmlNewNode(NULL, BAD_CAST "images");
@@ -379,6 +379,8 @@ static int ipc_receive(int client_sock)
 			xmlNewProp(tmp_node, BAD_CAST "atime", BAD_CAST strbuffer);
 			sprintf(strbuffer, "%d", image->rid);
 			xmlNewProp(tmp_node, BAD_CAST "rid", BAD_CAST strbuffer);
+			sprintf(strbuffer, "%llu", (unsigned long long)image->filesize);
+			xmlNewProp(tmp_node, BAD_CAST "size", BAD_CAST strbuffer);
 			xmlNewProp(tmp_node, BAD_CAST "file", BAD_CAST image->file);
 			xmlNewProp(tmp_node, BAD_CAST "servers", BAD_CAST "???"); // TODO
 			if (image->cache_file && image->cache_map)
@@ -643,10 +645,11 @@ void dnbd3_ipc_send(int cmd)
 			xmlNodePtr cur, childit;
 
 			// Print log
-			xmlChar *log = getTextFromPath(doc, "/data/log");
+			char *log = getTextFromPath(doc, "/data/log");
 			if (log)
 			{
 				printf("--- Last log lines ----\n%s\n\n", log);
+				xmlFree(log);
 			}
 
 			int watime = 17, wname = 0, wrid = 5;
@@ -655,10 +658,10 @@ void dnbd3_ipc_send(int cmd)
 				if (cur->type != XML_ELEMENT_NODE)
 					continue;
 				NEW_POINTERLIST; // This macro defines an array of pointers
-				xmlChar *vid = XML_GETPROP(cur, "name"); // XML_GETPROP is a macro wrapping xmlGetNoNsProp()
-				xmlChar *rid = XML_GETPROP(cur, "rid"); // Each of these calls allocates memory for the string
-				wname = MAX(wname, xmlStrlen(vid));
-				wrid = MAX(wrid, xmlStrlen(rid));
+				char *vid = XML_GETPROP(cur, "name"); // XML_GETPROP is a macro wrapping xmlGetNoNsProp()
+				char *rid = XML_GETPROP(cur, "rid"); // Each of these calls allocates memory for the string
+				wname = MAX(wname, strlen(vid));
+				wrid = MAX(wrid, strlen(rid));
 				FREE_POINTERLIST; // This macro simply frees all pointers in the above array
 			} END_FOR_EACH;
 
@@ -677,11 +680,11 @@ void dnbd3_ipc_send(int cmd)
 					continue;
 				NEW_POINTERLIST;
 				++count;
-				xmlChar *numatime = XML_GETPROP(cur, "atime");
-				xmlChar *vid = XML_GETPROP(cur, "name");
-				xmlChar *rid = XML_GETPROP(cur, "rid");
-				xmlChar *file = XML_GETPROP(cur, "file");
-				time_t at = (time_t)atol((char*)numatime);
+				char *numatime = XML_GETPROP(cur, "atime");
+				char *vid = XML_GETPROP(cur, "name");
+				char *rid = XML_GETPROP(cur, "rid");
+				char *file = XML_GETPROP(cur, "file");
+				time_t at = (time_t)atol(numatime);
 				struct tm *timeinfo = localtime(&at);
 				strftime(strbuffer, STRBUFLEN, "%d.%m.%y %H:%M:%S", timeinfo);
 				printf(format, strbuffer, vid, rid, file);
@@ -717,8 +720,8 @@ void dnbd3_ipc_send(int cmd)
 					continue;
 				NEW_POINTERLIST;
 				++count;
-				xmlChar *ip = XML_GETPROP(cur, "ip");
-				xmlChar *comment = XML_GETPROP(cur, "comment");
+				char *ip = XML_GETPROP(cur, "ip");
+				char *comment = XML_GETPROP(cur, "comment");
 				if (comment)
 					printf("%-30s (%s)\n", ip, comment);
 				else
@@ -728,9 +731,9 @@ void dnbd3_ipc_send(int cmd)
 					if (childit->type != XML_ELEMENT_NODE || childit->name == NULL || strcmp((const char*)childit->name, "namespace") != 0)
 						continue;
 					NEW_POINTERLIST;
-					xmlChar *name = XML_GETPROP(childit, "name");
-					xmlChar *replicate = XML_GETPROP(childit, "replicate");
-					xmlChar *recursive = XML_GETPROP(childit, "recursive");
+					char *name = XML_GETPROP(childit, "name");
+					char *replicate = XML_GETPROP(childit, "replicate");
+					char *recursive = XML_GETPROP(childit, "recursive");
 					printf("     %-40s ", name);
 					if (replicate && *replicate != '0')
 						printf(" replicate");
@@ -772,10 +775,10 @@ static int is_password_correct(xmlDocPtr doc)
 		memlogf("[WARNING] IPC access granted as no password is set!");
 		return 1;
 	}
-	xmlChar *pass = getTextFromPath(doc, "/data/password");
+	char *pass = getTextFromPath(doc, "/data/password");
 	if (pass == NULL)
 		return 0;
-	if (strcmp((char *)pass, _ipc_password) == 0)
+	if (strcmp(pass, _ipc_password) == 0)
 	{
 		xmlFree(pass);
 		return 1;
diff --git a/src/server/job.c b/src/server/job.c
index cf45681..6386423 100644
--- a/src/server/job.c
+++ b/src/server/job.c
@@ -46,7 +46,8 @@ static char keep_running = TRUE;
 // Private functions
 static char *get_free_device();
 static void query_servers();
-static void dnbd3_remove_alt_server(dnbd3_trusted_server_t *server);
+static void add_alt_server(dnbd3_image_t *image, dnbd3_host_t *host);
+static void remove_alt_server(dnbd3_trusted_server_t *server);
 static void update_image_atimes(time_t now);
 
 //
@@ -217,14 +218,105 @@ static void query_servers()
 		//
 		// Process data, update server info, add/remove this server as alt server for images, replicate images, etc.
 		xmlDocPtr doc = xmlReadMemory(xmlbuffer, header.size, "noname.xml", NULL, 0);
-		free(xmlbuffer);
-		xmlbuffer = NULL;
+
 		if (doc == NULL)
 		{
 			memlogf("[WARNING] Could not parse XML data received by other server.");
 			goto communication_error;
 		}
 		// Data seems ok
+		char *ns = getTextFromPath(doc, "/data/namespace");
+		if (ns && *ns == '\0')
+		{
+			xmlFree(ns);
+			ns = NULL;
+		}
+		else
+		{
+			printf("[DEBUG] Other server's default namespace is '%s'\n", ns);
+			if  (!is_valid_namespace(ns))
+			{
+				printf("[DEBUG] Ignoring invalid namespace from other server.\n");
+				xmlFree(ns);
+				ns = NULL;
+			}
+		}
+
+		xmlNodePtr cur;
+		FOR_EACH_NODE(doc, "/data/images/image", cur)
+		{
+			if (cur->type != XML_ELEMENT_NODE)
+				continue;
+			NEW_POINTERLIST;
+			char *image = XML_GETPROP(cur, "name");
+			char *ridstr = XML_GETPROP(cur, "rid");
+			if (!image || !ridstr)
+				goto free_current_image;
+			int rid = atoi(ridstr);
+			if (rid <= 0)
+			{
+				printf("[DEBUG] Ignoring remote image with rid %d\n", rid);
+				goto free_current_image;
+			}
+			char *slash = strrchr(image, '/');
+			if (slash == NULL)
+			{
+				if (!ns)
+					goto free_current_image;
+				if (!is_valid_imagename(image))
+				{
+					printf("[DEBUG] Invalid image name: '%s'\n", image);
+					goto free_current_image;
+				}
+				snprintf(xmlbuffer, MAX_IPC_PAYLOAD, "%s/%s", ns, image);
+			}
+			else
+			{
+				*slash++ = '\0';
+				if (!is_valid_namespace(image))
+				{
+					printf("[DEBUG] Ignoring remote image with invalid namespace '%s'\n", image);
+					goto free_current_image;
+				}
+				if (!is_valid_imagename(slash))
+				{
+					printf("[DEBUG] Ignoring remote image with invalid name '%s'\n", slash);
+					goto free_current_image;
+				}
+				snprintf(xmlbuffer, MAX_IPC_PAYLOAD, "%s/%s", image, slash);
+			}
+			// Image seems legit, check if there's a local copy
+			pthread_spin_lock(&_spinlock);
+			dnbd3_image_t *local_image = dnbd3_get_image(xmlbuffer, rid, FALSE);
+			if (local_image == NULL)
+			{
+				pthread_spin_unlock(&_spinlock);
+				// Image is NEW, add it!
+				// TODO: Check if replication is requested for this namespace
+				dnbd3_image_t newimage;
+				memset(&newimage, 0, sizeof(newimage));
+				newimage.config_group = xmlbuffer;
+				newimage.rid = rid;
+				dnbd3_add_image(&newimage);
+				pthread_spin_lock(&_spinlock);
+				local_image = dnbd3_get_image(xmlbuffer, rid, FALSE);
+				if (local_image)
+					add_alt_server(local_image, &server->host);
+				pthread_spin_unlock(&_spinlock);
+			}
+			else
+			{
+				// Image is already KNOWN, add alt server if appropriate
+				// TODO: Check if requested for namespace
+				add_alt_server(local_image, &server->host);
+				pthread_spin_unlock(&_spinlock);
+			}
+			// Cleanup
+free_current_image:
+			FREE_POINTERLIST;
+		} END_FOR_EACH;
+
+
 		// ...
 		xmlFreeDoc(doc);
 		//
@@ -236,7 +328,7 @@ communication_error:
 		if (g_slist_find(_trusted_servers, server))
 		{
 			if (server->unreachable < 10 && ++server->unreachable == 5)
-				dnbd3_remove_alt_server(server);
+				remove_alt_server(server);
 		}
 		pthread_spin_unlock(&_spinlock);
 	}
@@ -245,7 +337,57 @@ communication_error:
 /**
  * !! Call this while holding the lock !!
  */
-static void dnbd3_remove_alt_server(dnbd3_trusted_server_t *server)
+static void add_alt_server(dnbd3_image_t *image, dnbd3_host_t *host)
+{
+	int i;
+	for (i = 0; i < NUMBER_SERVERS; ++i)
+	{
+		if (is_same_server(host, &image->servers[i].host))
+		{	// Alt server already known for this image
+			if (image->servers[i].failures)
+			{	// It was disabled, re-enable and send info to clients
+				image->servers[i].failures = 0;
+				break;
+			}
+			else	// Alt-Server already known and active, do nothing
+				return;
+		}
+	}
+	// Add to list if it wasn't in there
+	if (i >= NUMBER_SERVERS)
+		for (i = 0; i < NUMBER_SERVERS; ++i)
+		{
+			if (image->servers[i].host.type == 0)
+			{
+				image->servers[i].host = *host;
+				break;
+			}
+		}
+	// Broadcast to connected clients
+	GSList *itc;
+	dnbd3_reply_t header;
+	header.cmd = CMD_GET_SERVERS;
+	header.magic = dnbd3_packet_magic;
+	header.size = sizeof(dnbd3_server_entry_t);
+	fixup_reply(header);
+	for (itc = _dnbd3_clients; itc; itc = itc->next)
+	{
+		dnbd3_client_t *const client = itc->data;
+		if (client->image == image)
+		{
+			// Don't send message directly as the lock is being held; instead, enqueue it
+			NEW_BINSTRING(message, sizeof(header) + sizeof(*host));
+			memcpy(message->data, &header, sizeof(header));
+			memcpy(message->data + sizeof(header), host, sizeof(*host));
+			client->sendqueue = g_slist_append(client->sendqueue, message);
+		}
+	}
+}
+
+/**
+ * !! Call this while holding the lock !!
+ */
+static void remove_alt_server(dnbd3_trusted_server_t *server)
 {
 	GSList *iti, *itc;
 	int i;
diff --git a/src/server/net.c b/src/server/net.c
index b351ed3..7456ebd 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -180,12 +180,16 @@ void *dnbd3_handle_query(void *dnbd3_client)
 					const time_t now = time(NULL);
 					if (!image)
 					{
-						printf("[DEBUG] Client requested non-existent image '%s' (rid:%d)\n", image_name, (int)rid);
+						printf("[DEBUG] Client requested non-existent image '%s' (rid:%d), rejected\n", image_name, (int)rid);
+					}
+					else if (!image->working)
+					{
+						printf("[DEBUG] Client requested non-working image '%s' (rid:%d), rejected\n", image_name, (int)rid);
 					}
 					else if ((image->delete_soft != 0 && image->delete_soft < now)
 					         || (image->delete_hard != 0 && image->delete_hard < now))
 					{
-						printf("[DEBUG] Client requested end-of-life image '%s' (rid:%d)\n", image_name, (int)rid);
+						printf("[DEBUG] Client requested end-of-life image '%s' (rid:%d), rejected\n", image_name, (int)rid);
 					}
 					else
 					{
diff --git a/src/server/saveload.c b/src/server/saveload.c
index b9c0164..365934b 100644
--- a/src/server/saveload.c
+++ b/src/server/saveload.c
@@ -152,9 +152,11 @@ int dnbd3_add_image(dnbd3_image_t *image)
 	}
 
 	dnbd3_image_t *newimage = prepare_image(image->config_group, image->rid, image->file, image->cache_file);
+	image = NULL;
 	if (newimage)
 	{
-		_dnbd3_images = g_slist_prepend(_dnbd3_images, image);
+		memlogf("[INFO] Added image '%s'", newimage->low_name);
+		_dnbd3_images = g_slist_prepend(_dnbd3_images, newimage);
 	}
 	else
 	{
@@ -163,10 +165,10 @@ int dnbd3_add_image(dnbd3_image_t *image)
 	}
 
 	// Adding image was successful, write config file
-	g_key_file_set_integer(_config_handle, image->config_group, "rid", image->rid);
-	g_key_file_set_string(_config_handle, image->config_group, "file", image->file);
+	g_key_file_set_integer(_config_handle, newimage->config_group, "rid", newimage->rid);
+	g_key_file_set_string(_config_handle, newimage->config_group, "file", newimage->file);
 	//g_key_file_set_string(_config_handle, image->name, "servers", image->serverss); // TODO: Save servers as string
-	g_key_file_set_string(_config_handle, image->config_group, "cache", image->cache_file);
+	g_key_file_set_string(_config_handle, newimage->config_group, "cache", newimage->cache_file);
 
 	pthread_spin_unlock(&_spinlock);
 
@@ -308,7 +310,7 @@ static dnbd3_image_t *prepare_image(char *image_name, int rid, char *image_file,
 		return NULL;
 	}
 
-	if (strchr(image_name, '.') == NULL && _local_namespace == NULL)
+	if (strchr(image_name, '/') == NULL && _local_namespace == NULL)
 	{
 		memlogf("[ERROR] Image '%s' has local name and no default namespace is defined; entry ignored.", image_name);
 		return NULL;
diff --git a/src/server/xmlutil.c b/src/server/xmlutil.c
index 62736cd..1718bfb 100644
--- a/src/server/xmlutil.c
+++ b/src/server/xmlutil.c
@@ -3,7 +3,7 @@
 #include <libxml/xpath.h>
 
 
-xmlChar *getTextFromPath(xmlDocPtr doc, char *xpath)
+char *getTextFromPath(xmlDocPtr doc, char *xpath)
 {
 	xmlXPathContextPtr xpathCtx = xmlXPathNewContext(doc);
 	if (xpathCtx == NULL)
@@ -14,12 +14,12 @@ xmlChar *getTextFromPath(xmlDocPtr doc, char *xpath)
 		xmlXPathFreeContext(xpathCtx);
 		return NULL;
 	}
-	xmlChar *retval = NULL;
+	char *retval = NULL;
 	if (xpathObj->stringval)
-		retval = xmlStrdup(xpathObj->stringval);
+		retval = (char*)xmlStrdup(xpathObj->stringval);
 	else if (xpathObj->nodesetval && xpathObj->nodesetval->nodeNr > 0 && xpathObj->nodesetval->nodeTab && xpathObj->nodesetval->nodeTab[0])
 	{
-		retval = xmlNodeGetContent(xpathObj->nodesetval->nodeTab[0]);
+		retval = (char*)xmlNodeGetContent(xpathObj->nodesetval->nodeTab[0]);
 	}
 	xmlXPathFreeObject(xpathObj);
 	xmlXPathFreeContext(xpathCtx);
diff --git a/src/server/xmlutil.h b/src/server/xmlutil.h
index 971d8a9..fddb317 100644
--- a/src/server/xmlutil.h
+++ b/src/server/xmlutil.h
@@ -4,7 +4,7 @@
 #include <libxml/xmlstring.h>
 #include <libxml/tree.h>
 
-xmlChar *getTextFromPath(xmlDocPtr doc, char *xpath);
+char *getTextFromPath(xmlDocPtr doc, char *xpath);
 
 #define FOR_EACH_NODE(_doc, _path, _node) do { \
 	xmlXPathContextPtr _makro_xpathCtx = xmlXPathNewContext(_doc); \
@@ -33,6 +33,6 @@ xmlChar *getTextFromPath(xmlDocPtr doc, char *xpath);
 		xmlFree(_makro_ptrlist[_makro_i_]); \
 	} } while(0)
 
-#define XML_GETPROP(_node, _name) (xmlChar*)(_makro_ptrlist[(_makro_usedcount >= NUM_POINTERS_IN_LIST ? 0 : _makro_usedcount++)] = xmlGetNoNsProp(_node, BAD_CAST _name))
+#define XML_GETPROP(_node, _name) (char*)(_makro_ptrlist[(_makro_usedcount >= NUM_POINTERS_IN_LIST ? 0 : _makro_usedcount++)] = xmlGetNoNsProp(_node, BAD_CAST _name))
 
 #endif