[KERNEL] Tell server whether we're a client or a server in proxy mode

[KERNEL] SysFS: Return empty string for current_server if not connected
[SERVER] Code refactoring

5 files changed, 78 insertions, 53 deletions

diff --git a/src/server/ipc.c b/src/server/ipc.c
index ebc907b..37ca36f 100644
--- a/src/server/ipc.c
+++ b/src/server/ipc.c
@@ -364,7 +364,8 @@ static int ipc_receive(int client_sock)
 	GSList *iterator = NULL;
 
 	struct tm *timeinfo;
-	char time_buff[64], rid[20], ipaddr[100];
+#define STRBUFLEN 100
+	char strbuffer[STRBUFLEN];
 
 	dnbd3_ipc_t header;
 
@@ -428,18 +429,27 @@ static int ipc_receive(int client_sock)
 		for (iterator = _dnbd3_images; iterator; iterator = iterator->next)
 		{
 			const dnbd3_image_t *image = iterator->data;
-			sprintf(rid, "%d", image->rid);
-			timeinfo = localtime(&image->atime);
-			strftime(time_buff, 64, "%d.%m.%y %H:%M:%S", timeinfo);
 			tmp_node = xmlNewNode(NULL, BAD_CAST "image");
 			if (tmp_node == NULL)
 				goto get_info_reply_cleanup;
 			xmlNewProp(tmp_node, BAD_CAST "name", BAD_CAST image->config_group);
-			xmlNewProp(tmp_node, BAD_CAST "atime", BAD_CAST time_buff);
-			xmlNewProp(tmp_node, BAD_CAST "rid", BAD_CAST rid);
+			timeinfo = localtime(&image->atime);
+			strftime(strbuffer, STRBUFLEN, "%d.%m.%y %H:%M:%S", timeinfo);
+			xmlNewProp(tmp_node, BAD_CAST "atime", BAD_CAST strbuffer);
+			sprintf(strbuffer, "%d", image->rid);
+			xmlNewProp(tmp_node, BAD_CAST "rid", BAD_CAST strbuffer);
 			xmlNewProp(tmp_node, BAD_CAST "file", BAD_CAST image->file);
-			xmlNewProp(tmp_node, BAD_CAST "servers", BAD_CAST "???");
-			xmlNewProp(tmp_node, BAD_CAST "cache", BAD_CAST image->cache_file);
+			xmlNewProp(tmp_node, BAD_CAST "servers", BAD_CAST "???"); // TODO
+			if (image->cache_file && image->cache_map)
+			{
+				xmlNewProp(tmp_node, BAD_CAST "cachefile", BAD_CAST image->cache_file);
+				int i, complete = 0, size = IMGSIZE_TO_MAPBYTES(image->filesize);
+				for (i = 0; i < size; ++i)
+					if (image->cache_map[i])
+						complete += 100;
+				sprintf(strbuffer, "%d", complete / size);
+				xmlNewProp(tmp_node, BAD_CAST "cachefill", BAD_CAST image->cache_file);
+			}
 			xmlAddChild(images_node, tmp_node);
 		}
 		// Clients
@@ -455,9 +465,9 @@ static int ipc_receive(int client_sock)
 				tmp_node = xmlNewNode(NULL, BAD_CAST "client");
 				if (tmp_node == NULL)
 					goto get_info_reply_cleanup;
-				*ipaddr = '\0';
-				inet_ntop(client->addrtype, client->ipaddr, ipaddr, 100);
-				xmlNewProp(tmp_node, BAD_CAST "ip", BAD_CAST ipaddr);
+				*strbuffer = '\0';
+				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);
 			}
diff --git a/src/server/net.c b/src/server/net.c
index b1a7b20..37ac0b4 100644
--- a/src/server/net.c
+++ b/src/server/net.c
@@ -160,6 +160,7 @@ void *dnbd3_handle_query(void *dnbd3_client)
     			client_version = serializer_get_uint16(&payload);
 				image_name = serializer_get_string(&payload);
 				rid = serializer_get_uint16(&payload);
+				client->is_server = serializer_get_uint8(&payload);
 				if (request.size < 3 || !image_name || client_version < MIN_SUPPORTED_CLIENT)
 				{
 					if (client_version < MIN_SUPPORTED_CLIENT)
@@ -208,7 +209,8 @@ void *dnbd3_handle_query(void *dnbd3_client)
 							else
 							{
 								client->image = image;
-								image->atime = time(NULL); // TODO: check if mutex is needed
+								if (!client->is_server)
+									image->atime = time(NULL); // TODO: check if mutex is needed
 
 								if (image->cache_map && image->cache_file)
 									image_cache = open(image->cache_file, O_RDWR);
@@ -288,8 +290,8 @@ void *dnbd3_handle_query(void *dnbd3_client)
             // first make sure the whole requested part is in the local cache file
             while(cur_offset < last_offset)
             {
-                map_y = cur_offset >> 15;
-                map_x = (cur_offset >> 12) & 7; // mod 256
+                map_y = cur_offset >> 15; // div 32768
+                map_x = (cur_offset >> 12) & 7; // (X div 4096) mod 8
                 bit_mask = 0b00000001 << (map_x);
 
                 cur_offset += 4096;
diff --git a/src/server/server.c b/src/server/server.c
index 28da0ae..1ca55fa 100644
--- a/src/server/server.c
+++ b/src/server/server.c
@@ -52,16 +52,16 @@ void dnbd3_print_help(char* argv_0)
 {
     printf("Usage: %s [OPTIONS]...\n", argv_0);
     printf("Start the DNBD3 server\n");
-    printf("-f or --file \t\t Configuration file (default /etc/dnbd3-server.conf)\n");
+    printf("-f or --file        Configuration file (default /etc/dnbd3-server.conf)\n");
 #ifdef _DEBUG
-    printf("-d or --delay \t\t Add a fake network delay of X µs\n");
+    printf("-d or --delay       Add a fake network delay of X µs\n");
 #endif
-    printf("-n or --nodaemon \t Start server in foreground\n");
-    printf("-r or --reload \t\t Reload configuration file\n");
-    printf("-s or --stop \t\t Stop running dnbd3-server\n");
-    printf("-i or --info \t\t Print connected clients and used images\n");
-    printf("-H or --help \t\t Show this help text and quit\n");
-    printf("-V or --version \t Show version and quit\n");
+    printf("-n or --nodaemon    Start server in foreground\n");
+    printf("-r or --reload      Reload configuration file\n");
+    printf("-s or --stop        Stop running dnbd3-server\n");
+    printf("-i or --info        Print connected clients and used images\n");
+    printf("-H or --help        Show this help text and quit\n");
+    printf("-V or --version     Show version and quit\n");
     exit(0);
 }
 
diff --git a/src/server/server.h b/src/server/server.h
index 90aae5c..832777e 100644
--- a/src/server/server.h
+++ b/src/server/server.h
@@ -28,6 +28,15 @@
 #include "../config.h"
 #include "../types.h"
 
+// one byte in the map covers 8 4kib blocks, so 32kib per byte
+// "+ (1 << 15) - 1" is required to account for the last bit of
+// the image that is smaller than 32kib
+// this would be the case whenever the image file size is not a
+// multiple of 32kib (= the number of blocks is not divisible by 8)
+// ie: if the image is 49152 bytes and you do 49152 >> 15 you get 1,
+// but you actually need 2 bytes to have a complete cache map
+#define IMGSIZE_TO_MAPBYTES(bytes) ((int)(((bytes) + (1 << 15) - 1) >> 15))
+
 typedef struct
 {
 	char *config_group; // exact name of group in config file that represents this image
@@ -42,13 +51,15 @@ typedef struct
     char working;	// whether this image is considered working. local images are "working" if the local file exists, proxied images have to have at least one working upstream server or a complete local cache file
     time_t delete_soft; // unixtime telling when this image should be deleted. if there are still clients using this image it weill be kept, but new clients requesting the image will be rejected. 0 = never
     time_t delete_hard; // unixtime telling when this image should be deleted, no matter if there are still clients connected. 0 = never
+    uint8_t relayed;		// TRUE if relayed from other server (needs dnbd3 client module loaded)
 } dnbd3_image_t;
 
 typedef struct
 {
     int sock;
     uint8_t ipaddr[16];
-    uint8_t addrtype; 	// ip version (AF_INET or AF_INET6)
+    uint8_t addrtype; 	       // ip version (AF_INET or AF_INET6)
+    uint8_t is_server;         // TRUE if a server in proxy mode, FALSE if real client
     pthread_t thread;
     dnbd3_image_t *image;
 } dnbd3_client_t;
diff --git a/src/server/utils.c b/src/server/utils.c
index 665d96d..391992d 100644
--- a/src/server/utils.c
+++ b/src/server/utils.c
@@ -438,9 +438,9 @@ static dnbd3_image_t *prepare_image(char *image_name, int rid, char *image_file,
 	image->config_group = strdup(image_name);
 
 	image->rid = rid;
-	const char relayed = (image_file == NULL || image_file == '\0');
+	image->relayed = (image_file == NULL || image_file == '\0');
 
-	if (relayed)	// Image is relayed (this server acts as proxy)
+	if (image->relayed)	// Image is relayed (this server acts as proxy)
 	{
 		if (strchr(image_name, '/') == NULL)
 		{
@@ -508,45 +508,47 @@ static dnbd3_image_t *prepare_image(char *image_name, int rid, char *image_file,
 		}
 		else if (image->filesize > 0)
 		{
-			const size_t map_len_bytes = (image->filesize + (1 << 15) - 1) >> 15;
+			const size_t map_len_bytes = IMGSIZE_TO_MAPBYTES(image->filesize);
 			image->cache_map = calloc(map_len_bytes, sizeof(uint8_t));
 			// read cache map from file
-			// one byte in the map covers 8 4kib blocks, so 32kib per byte
-			// "+ (1 << 15) - 1" is required to account for the last bit of
-			// the image that is smaller than 32kib
-			// this would be the case whenever the image file size is not a
-			// multiple of 32kib (= the number of blocks is not divisible by 8)
-			// ie: if the image is 49152 bytes and you do 49152 >> 15 you get 1,
-			// but you actually need 2 bytes to have a complete cache map
 			char tmp[strlen(image->cache_file) + 5];
 			strcpy(tmp, image->cache_file);
 			strcat(tmp, ".map");
-			fd = open(tmp, O_RDONLY); // TODO: Check if map file has expected size
+			fd = open(tmp, O_RDONLY);
 			if (fd >= 0)
 			{
-				read(fd, image->cache_map, map_len_bytes * sizeof(uint8_t));
-				close(fd);
-				// If the whole image is cached, mark it as working right away without waiting for an upstream server
-				image->working = 1;
-				for (j = 0; j < map_len_bytes - 1; ++j)
+				const off_t size = lseek(fd, 0, SEEK_END);
+				if (size != map_len_bytes)
 				{
-					if (image->cache_map[j] != 0xFF)
+					memlogf("[DEBUG] Cache-Map of %s is corrupted (%d != %d)", image_name, (int)size, (int)map_len_bytes);
+				}
+				else
+				{
+					lseek(fd, 0, SEEK_SET);
+					read(fd, image->cache_map, map_len_bytes);
+					// If the whole image is cached, mark it as working right away without waiting for an upstream server
+					image->working = 1;
+					for (j = 0; j < map_len_bytes - 1; ++j)
 					{
-						image->working = 0;
-						break;
+						if (image->cache_map[j] != 0xFF)
+						{
+							image->working = 0;
+							break;
+						}
 					}
+					const int blocks_in_last_byte = (image->filesize >> 12) & 7;
+					uint8_t last_byte = 0;
+					if (blocks_in_last_byte == 0)
+						last_byte = 0xFF;
+					else
+						for (j = 0; j < blocks_in_last_byte; ++j)
+							last_byte |= (1 << j);
+					if ((image->cache_map[map_len_bytes - 1] & last_byte) != last_byte)
+						image->working = 0;
+					else
+						memlogf("[INFO] Instantly publishing relayed image '%s' because the local cache copy is complete", image_name);
 				}
-				const int blocks_in_last_byte = (image->filesize >> 12) & 7;
-				uint8_t last_byte = 0;
-				if (blocks_in_last_byte == 0)
-					last_byte = 0xFF;
-				else
-					for (j = 0; j < blocks_in_last_byte; ++j)
-						last_byte = (last_byte << 1) | 1;
-				if ((image->cache_map[map_len_bytes - 1] & last_byte) != last_byte)
-					image->working = 0;
-				else
-					memlogf("[INFO] Instantly publishing relayed image '%s' because the local cache copy is complete", image_name);
+				close(fd);
 			}
 
 			/*