WIP : use user defined UID / GID for storage file operations.

conf/umtprd.conf

@@ -8,6 +8,13 @@
 
 loop_on_disconnect 0
 
+# Force the default UID/GID to use for each storage file operations.
+# Note : When no default UID/GID are specified the umtprd process UID/GID 
+#        are used instead.
+
+#default_uid 33
+#default_gid 33
+
 # Storage command : Create add a storage entry point. Up to 16 entry points supported
 # Syntax : storage "PATH" "NAME" "OPTIONS" 
 # Possible store options :
@@ -20,11 +27,15 @@ storage "/"      "root folder" "rw"
 storage "/home"  "home folder" "ro"
 storage "/www"   "www folder" "ro,notmounted"
 
-# add the "locked" option to enable the store lock/unlock feature.
-# execute "umtprd -cmd:unlock" to unlock the locked stores and "umtprd -cmd:lock" to lock them again.
+# Add the "locked" option to enable the store lock/unlock feature.
+# Execute "umtprd -cmd:unlock" to unlock the locked stores and "umtprd -cmd:lock" to lock them again.
 
 storage "/"      "lockable root folder" "rw,locked"
 
+# A user storage using another UID/GID for file operations.
+
+storage "/home/user" "user folder" "rw,locked,uid=33,gid=33"
+
 #
 # Uncomment the following line if you want to 
 # override the system default umask value for 

inc/mtp.h

@@ -81,6 +81,8 @@ typedef struct mtp_storage_
 	char * description;
 	uint32_t storage_id;
 	uint32_t flags;
+	int uid;
+	int gid;
 }mtp_storage;
 
 #define UMTP_STORAGE_LOCKED      0x00000010
@@ -132,6 +134,12 @@ typedef struct mtp_ctx_
 
 	int no_inotify;
 
+	int uid,euid;
+	int gid,egid;
+
+	int default_uid;
+	int default_gid;
+
 	volatile int cancel_req;
 	volatile int transferring_file_data;
 }mtp_ctx;
@@ -143,9 +151,10 @@ void mtp_set_usb_handle(mtp_ctx * ctx, void * handle, uint32_t max_packet_size);
 
 int mtp_load_config_file(mtp_ctx * context, const char * conffile);
 
-uint32_t mtp_add_storage(mtp_ctx * ctx, char * path, char * description, uint32_t flags);
+uint32_t mtp_add_storage(mtp_ctx * ctx, char * path, char * description, int uid, int gid, uint32_t flags);
 int mtp_remove_storage(mtp_ctx * ctx, char * name);
 int mtp_get_storage_index_by_name(mtp_ctx * ctx, char * name);
+int mtp_get_storage_index_by_id(mtp_ctx * ctx, uint32_t storage_id);
 uint32_t mtp_get_storage_id_by_name(mtp_ctx * ctx, char * name);
 char * mtp_get_storage_description(mtp_ctx * ctx, uint32_t storage_id);
 char * mtp_get_storage_root(mtp_ctx * ctx, uint32_t storage_id);
@@ -161,6 +170,6 @@ int build_response(mtp_ctx * ctx, uint32_t tx_id, uint16_t type, uint16_t status
 int check_and_send_USB_ZLP(mtp_ctx * ctx , int size);
 int parse_incomming_dataset(mtp_ctx * ctx,void * datain,int size,uint32_t * newhandle, uint32_t parent_handle, uint32_t storage_id);
 
-#define APP_VERSION "v1.5.1"
+#define APP_VERSION "v1.6.1"
 
 #endif

inc/mtp_helpers.h

@@ -34,4 +34,10 @@ uint64_t peek64(void * buffer, int index, int typesize);
 int poke_string(void * buffer, int index, int maxsize, const char *str);
 int poke_array(void * buffer, int index, int maxsize, int size, int elementsize, const unsigned char *bufferin,int prefixed);
 uint16_t posix_to_mtp_errcode(int err);
+
+int set_giduid(mtp_ctx * ctx,int uid,int gid);
+
+int set_storage_giduid(mtp_ctx * ctx,uint32_t storage_id);
+int restore_giduid(mtp_ctx * ctx);
+
 #endif

src/fs_handles_db.c

@@ -36,6 +36,8 @@
 #include <dirent.h>
 
 #include "mtp.h"
+#include "mtp_helpers.h"
+
 #include "fs_handles_db.h"
 #include "inotify.h"
 #include "logs_out.h"
@@ -448,7 +450,10 @@ int scan_and_add_folder(fs_handles_db * db, char * base, uint32_t parent, uint32
 		}
 	}while(entry);
 
-	return 0;
+	if(dir)
+		return 0;
+	else
+		return -1;
 }
 
 fs_entry * init_search_handle(fs_handles_db * db, uint32_t parent, uint32_t storage_id)
@@ -602,7 +607,14 @@ int entry_open(fs_handles_db * db, fs_entry * entry)
 	full_path = build_full_path(db,mtp_get_storage_root(db->mtp_ctx, entry->storage_id), entry);
 	if( full_path )
 	{
-		file = open(full_path,O_RDONLY | O_LARGEFILE);
+		file = -1;
+
+		if(!set_storage_giduid(db->mtp_ctx, entry->storage_id))
+		{
+			file = open(full_path,O_RDONLY | O_LARGEFILE);
+		}
+
+		restore_giduid(db->mtp_ctx);
 
 		if( file == -1 )
 			PRINT_DEBUG("entry_open : Can't open %s !",full_path);

src/mtp.c

@@ -77,6 +77,14 @@ mtp_ctx * mtp_init_responder()
 		if(!ctx->temp_array)
 			goto init_error;
 
+		ctx->uid = getuid();
+		ctx->euid = geteuid();
+		ctx->gid = getgid();
+		ctx->egid = getegid();
+
+		ctx->default_uid = -1;
+		ctx->default_gid = -1;
+
 		ctx->SetObjectPropValue_Handle = 0xFFFFFFFF;
 
 		pthread_mutex_init ( &ctx->inotify_mutex, NULL);
@@ -172,7 +180,7 @@ int parse_incomming_dataset(mtp_ctx * ctx,void * datain,int size,uint32_t * newh
 	char * parent_folder;
 	char * tmp_path;
 	uint32_t storage_flags;
-	int i,ret_code;
+	int i,ret_code,ret;
 	fs_entry * entry;
 	int file;
 	filefoundinfo tmp_file_entry;
@@ -250,7 +258,16 @@ int parse_incomming_dataset(mtp_ctx * ctx,void * datain,int size,uint32_t * newh
 							sprintf(tmp_path,"%s/%s",parent_folder,tmp_str);
 							PRINT_DEBUG("MTP_OPERATION_SEND_OBJECT_INFO : Creating %s ...",tmp_path);
 
-							if( mkdir(tmp_path, 0700) )
+							ret = -1;
+
+							if(!set_storage_giduid(ctx, entry->storage_id))
+							{
+								ret = mkdir(tmp_path, 0700);
+							}
+
+							restore_giduid(ctx);
+
+							if( ret )
 							{
 								PRINT_WARN("MTP_OPERATION_SEND_OBJECT_INFO : Can't create %s ...",tmp_path);
 
@@ -334,7 +351,15 @@ int parse_incomming_dataset(mtp_ctx * ctx,void * datain,int size,uint32_t * newh
 							strcpy(tmp_file_entry.filename,tmp_str);
 							tmp_file_entry.size = objectsize;
 
-							file = open(tmp_path,O_WRONLY | O_CREAT | O_TRUNC | O_LARGEFILE, S_IRUSR|S_IWUSR);
+							file = -1;
+
+							if(!set_storage_giduid(ctx, storage_id))
+							{
+								file = open(tmp_path,O_WRONLY | O_CREAT | O_TRUNC | O_LARGEFILE, S_IRUSR|S_IWUSR);
+							}
+
+							restore_giduid(ctx);
+
 							if( file == -1)
 							{
 								PRINT_WARN("MTP_OPERATION_SEND_OBJECT_INFO : Can't create %s ...",tmp_path);
@@ -654,7 +679,7 @@ void mtp_set_usb_handle(mtp_ctx * ctx, void * handle, uint32_t max_packet_size)
 	ctx->max_packet_size = max_packet_size;
 }
 
-uint32_t mtp_add_storage(mtp_ctx * ctx, char * path, char * description, uint32_t flags)
+uint32_t mtp_add_storage(mtp_ctx * ctx, char * path, char * description, int uid, int gid, uint32_t flags)
 {
 	int i;
 
@@ -673,6 +698,9 @@ uint32_t mtp_add_storage(mtp_ctx * ctx, char * path, char * description, uint32_
 
 			if(ctx->storages[i].root_path && ctx->storages[i].description)
 			{
+				ctx->storages[i].uid = uid;
+				ctx->storages[i].gid = gid;
+
 				strcpy(ctx->storages[i].root_path,path);
 				strcpy(ctx->storages[i].description,description);
 				ctx->storages[i].flags = flags;
@@ -698,6 +726,8 @@ uint32_t mtp_add_storage(mtp_ctx * ctx, char * path, char * description, uint32_
 				ctx->storages[i].description =  NULL;
 				ctx->storages[i].flags =  0x00000000;
 				ctx->storages[i].storage_id = 0x00000000;
+				ctx->storages[i].uid = -1;
+				ctx->storages[i].gid = -1;
 
 				return ctx->storages[i].storage_id;
 			}
@@ -722,6 +752,8 @@ int mtp_remove_storage(mtp_ctx * ctx, char * name)
 	ctx->storages[index].description = NULL;
 	ctx->storages[index].flags = 0x00000000;
 	ctx->storages[index].storage_id = 0x00000000;
+	ctx->storages[index].uid = -1;
+	ctx->storages[index].gid = -1;
 
 	return 0;
 }
@@ -778,6 +810,31 @@ int mtp_get_storage_index_by_name(mtp_ctx * ctx, char * name)
 	return -1;
 }
 
+int mtp_get_storage_index_by_id(mtp_ctx * ctx, uint32_t storage_id)
+{
+	int i;
+
+	PRINT_DEBUG("mtp_get_storage_index_by_id : 0x%X", storage_id );
+
+	i = 0;
+	while(i < MAX_STORAGE_NB)
+	{
+		if( ctx->storages[i].root_path )
+		{
+			if( ctx->storages[i].storage_id == storage_id )
+			{
+				PRINT_DEBUG("mtp_get_storage_index_by_id : %.8X -> %d",
+					    storage_id,
+					    i );
+				return i;
+			}
+		}
+		i++;
+	}
+
+	return -1;
+}
+
 char * mtp_get_storage_root(mtp_ctx * ctx, uint32_t storage_id)
 {
 	int i;