Initial image file creation

doc/rasctl.1

@@ -28,8 +28,11 @@ Note: The command and type arguments are case insensitive. Only the first letter
 
 .SH OPTIONS
 .TP
+.BR \-a\fI " "\fIFILENAME:FILESIZE
+Create a disk image file with the specified name and size in bytes.
+.TP
 .BR \-g\fI " "\fILOG_LEVEL
-The rascsi log level to set (trace, debug, info, warn, err, critical, off)
+Set the rascsi log level (trace, debug, info, warn, err, critical, off).
 .TP
 .BR \-h\fI " " \fIHOST
 The rascsi host to connect to, default is 'localhost'.

doc/rasctl_man_page.txt

@@ -1,32 +1,39 @@
 !!   ------ THIS FILE IS AUTO_GENERATED! DO NOT MANUALLY UPDATE!!!
-!!   ------ The native file is rasctl.1. Re-run 'make docs' after updating
+!!   ------ The native file is rasctl.1. Re-run 'make docs' after updating\n\n
-
+rascsi(1)                   General Commands Manual                  rascsi(1)
-
-rascsi(1)                                                                         General Commands Manual                                                                        rascsi(1)
 
 NAME
        rasctl - Sends management commands to the rascsi process
 
 SYNOPSIS
-       rasctl -l | -s | [-g LOG_LEVEL] [-h HOST] [-p PORT] [-r RESERVED_IDS] [-v] -i ID [-c CMD] [-f FILE] [-n NAME] [-t TYPE] [-u UNIT]
+       rasctl  -l  | -s | [-g LOG_LEVEL] [-h HOST] [-p PORT] [-r RESERVED_IDS]
+       [-v] -i ID [-c CMD] [-f FILE] [-n NAME] [-t TYPE] [-u UNIT]
 
 DESCRIPTION
-       rasctl Sends commands to the rascsi process to make configuration adjustments at runtime or to check the status of the devices.
+       rasctl Sends commands to the rascsi process to make  configuration  ad‐
+       justments at runtime or to check the status of the devices.
 
        Either the -i or -l option should be specified at one time. Not both.
 
        You do NOT need root privileges to use rasctl.
 
-       Note: The command and type arguments are case insensitive. Only the first letter of the command/type is evaluated by the tool.
+       Note:  The  command  and  type arguments are case insensitive. Only the
+       first letter of the command/type is evaluated by the tool.
 
 OPTIONS
+       -a FILENAME:FILESIZE
+              Create a disk image file with the specified  name  and  size  in
+              bytes.
+
        -g LOG_LEVEL
-              The rascsi log level to set (trace, debug, info, warn, err, critical, off)
+              Set  the rascsi log level (trace, debug, info, warn, err, criti‐
+              cal, off).
 
        -h HOST
               The rascsi host to connect to, default is 'localhost'.
 
-       -l     List all of the devices that are currently being emulated by RaSCSI, as well as their current status.
+       -l     List all of the devices that are  currently  being  emulated  by
+              RaSCSI, as well as their current status.
 
        -p PORT
               The rascsi port to connect to, default is 6868.
@@ -34,7 +41,8 @@ OPTIONS
        -r RESERVED_IDS
               Comma-separated list of IDs to reserve.
 
-       -s     Display server-side settings like available images or supported device types.
+       -s     Display  server-side settings like available images or supported
+              device types.
 
        -v     Display the rascsi version.
 
@@ -45,21 +53,28 @@ OPTIONS
                  d(etach): Detach disk
                  i(nsert): Insert media (removable media devices only)
                  e(ject): Eject media (removable media devices only)
-                 p(rotect): Write protect the medium (not for CD-ROMs, which are always read-only)
+                 p(rotect): Write protect the medium (not for  CD-ROMs,  which
-                 u(nprotect): Remove write protection from the medium (not for CD-ROMs, which are always read-only)
+              are always read-only)
+                 u(nprotect): Remove write protection from the medium (not for
+              CD-ROMs, which are always read-only)
                  s(how): Display device information
 
               eject, protect and unprotect are idempotent.
 
        -b BLOCK_SIZE
-              The optional block size. For SCSI drives 512, 1024, 2048 or 4096 bytes, default size is 512 bytes. For SASI drives 256 or 1024 bytes, default is 256 bytes.
+              The optional block size. For SCSI drives 512, 1024, 2048 or 4096
+              bytes,  default  size  is 512 bytes. For SASI drives 256 or 1024
+              bytes, default is 256 bytes.
 
        -f FILE
-              Path to the disk image file. See the rascsi(1) man page for allowable file types.
+              Path to the disk image file. See the rascsi(1) man page for  al‐
+              lowable file types.
 
        -t TYPE
-              Specifies  the  device type. This type overrides the type derived from the file extension of the specified image. See the rascsi(1) man page for the available device types.
+              Specifies  the device type. This type overrides the type derived
-              For some types there are shortcuts (only the first letter is required):
+              from  the  file  extension  of  the  specified  image.  See  the
+              rascsi(1)  man  page  for  the  available device types. For some
+              types there are shortcuts (only the first letter is required):
                  hd: SCSI hard disk drive
                  rm: SCSI removable media drive
                  cd: CD-ROM
@@ -68,11 +83,17 @@ OPTIONS
                  daynaport: DaynaPORT network adapter
 
        -n VENDOR:PRODUCT:REVISION
-              The vendor, product and revision for the device, to be returned with the INQUIRY data. A complete set of name components must be provided. VENDOR may have up to 8,  PRODUCT
+              The vendor, product and revision for the device, to be  returned
-              up to 16, REVISION up to 4 characters. Padding with blanks to the maxium length is automatically applied. Once set the name of a device cannot be changed.
+              with the INQUIRY data. A complete set of name components must be
+              provided. VENDOR may have up to 8, PRODUCT up to 16, REVISION up
+              to 4 characters. Padding with blanks to the maxium length is au‐
+              tomatically applied. Once set the name of  a  device  cannot  be
+              changed.
 
        -u UNIT
-              Unit number (0 or 1). This will default to 0. This option is only used when there are multiple SCSI devices on a shared SCSI controller. (This is not common)
+              Unit  number  (0  or  1). This will default to 0. This option is
+              only used when there are multiple SCSI devices on a shared  SCSI
+              controller. (This is not common)
 
 EXAMPLES
        Show a listing of all of the SCSI devices and their current status.
@@ -85,12 +106,14 @@ EXAMPLES
           |  0 |  1 | SCHD | /home/pi/harddisk.hda
           +----+----+------+-------------------------------------
 
-       Request the RaSCSI process to attach a disk (assumed) to SCSI ID 0 with the contents of the file system image "HDIIMAGE0.HDS".
+       Request the RaSCSI process to attach a disk (assumed) to SCSI ID 0 with
+       the contents of the file system image "HDIIMAGE0.HDS".
           rasctl -i 0 -f HDIIMAGE0.HDS
 
 SEE ALSO
        rascsi(1) scsimon(1)
 
-       Full documentation is available at: <https://www.github.com/akuker/RASCSI/wiki/>
+       Full          documentation          is          available          at:
+       <https://www.github.com/akuker/RASCSI/wiki/>
 
-                                                                                                                                                                                 rascsi(1)
+                                                                     rascsi(1)

src/raspberrypi/rascsi.cpp

@@ -705,6 +705,55 @@ string SetReservedIds(const list<string>& ids_to_reserve)
 	return "";
 }
 
+bool CreateImage(int fd, const PbCommand& command)
+{
+	if (command.params().size() < 2 || command.params().Get(0).empty() || command.params().Get(1).empty()) {
+		return ReturnStatus(fd, false, "Can't create image file: Missing filename or file size");
+	}
+
+	string filename = command.params().Get(0);
+	if (filename[0] != '/') {
+		filename = default_image_folder + "/" + filename;
+	}
+
+	off_t len;
+	try {
+		len = stoul(command.params().Get(1));
+	}
+	catch(const invalid_argument& e) {
+		return ReturnStatus(fd, false, "Invalid image file size " + command.params().Get(1));
+	}
+	catch(const out_of_range& e) {
+		return ReturnStatus(fd, false, "Invalid image file size " + command.params().Get(1));
+	}
+	if (len < 256) {
+		ostringstream error;
+		error << "Invalid image file size " << len;
+		return ReturnStatus(fd, false, error.str());
+	}
+
+	struct stat st;
+	if (!stat(filename.c_str(), &st)) {
+		return ReturnStatus(fd, false, "Image file '" + filename + "' already exists");
+	}
+
+	// Since rascsi is running as root ensure that others can access the file
+	int image_fd = open(filename.c_str(), O_CREAT|O_WRONLY, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
+	if (image_fd == -1) {
+		return ReturnStatus(fd, false, "Can't create image file '" + filename + "': " + string(strerror(errno)));
+	}
+
+	if (fallocate(image_fd, 0, 0, len) == -1) {
+		close(image_fd);
+
+		return ReturnStatus(fd, false, "Can't allocate space for image file '" + filename + "': " + string(strerror(errno)));
+	}
+
+	close(image_fd);
+
+	return ReturnStatus(fd);
+}
+
 void DetachAll()
 {
 	Device *map[devices.size()];
@@ -1146,11 +1195,14 @@ bool ProcessCmd(const int fd, const PbCommand& command)
 		const list<string> ids = { command.params().begin(), command.params().end() };
 		string invalid_id = SetReservedIds(ids);
 		if (!invalid_id.empty()) {
-			return ReturnStatus(fd, false,"Invalid ID " + invalid_id + " for " + PbOperation_Name(RESERVE));
+			return ReturnStatus(fd, false, "Invalid ID " + invalid_id + " for " + PbOperation_Name(RESERVE));
 		}
 
 		return ReturnStatus(fd);
 	}
+	else if (command.operation() == CREATE_IMAGE) {
+		return CreateImage(fd, command);
+	}
 
 	const vector<string> params = { command.params().begin(), command.params().end() };
 

src/raspberrypi/rascsi_interface.proto

@@ -59,6 +59,10 @@ enum PbOperation {
     // IDs blocked from being used, usually the IDs of the initiators (computers) in the SCSI chain.
     // PbCommand.params contains the list of IDs to reserve, or is empty in order not to reserve any ID.
     RESERVE = 14;
+    // Create an image file. The image file must not yet exist.
+    // PbCommand.params(0) contains the filename, PbCommand.params(1) contains the file size in bytes.
+    // If the filename is relative (does not start with a slash) the file is created in the default image folder.
+    CREATE_IMAGE = 15;
 }
 
 // The properties supported by a device, helping clients to offer a good user experience

src/raspberrypi/rasctl.cpp

@@ -206,6 +206,21 @@ void CommandReserve(const string&hostname, int port, const string& reserved_ids)
     SendCommand(hostname.c_str(), port, command, result);
 }
 
+void CommandCreateImage(const string&hostname, int port, const string& image_params)
+{
+	PbCommand command;
+	command.set_operation(CREATE_IMAGE);
+
+	size_t separatorPos = image_params.find(COMPONENT_SEPARATOR);
+	if (separatorPos != string::npos) {
+		command.add_params(image_params.substr(0, separatorPos));
+		command.add_params(image_params.substr(separatorPos + 1));
+	}
+
+    PbResult result;
+    SendCommand(hostname.c_str(), port, command, result);
+}
+
 void CommandDefaultImageFolder(const string& hostname, int port, const string& folder)
 {
 	PbCommand command;
@@ -502,11 +517,12 @@ int main(int argc, char* argv[])
 	string log_level;
 	string default_folder;
 	string reserved_ids;
+	string image_params;
 	bool list = false;
 
 	opterr = 1;
 	int opt;
-	while ((opt = getopt(argc, argv, "b:c:d:f:g:h:i:n:p:r:t:u:lsv")) != -1) {
+	while ((opt = getopt(argc, argv, "a:b:c:d:f:g:h:i:n:p:r:t:u:lsv")) != -1) {
 		switch (opt) {
 			case 'i':
 				device->set_id(optarg[0] - '0');
@@ -516,6 +532,11 @@ int main(int argc, char* argv[])
 				device->set_unit(optarg[0] - '0');
 				break;
 
+			case 'a':
+				command.set_operation(CREATE_IMAGE);
+				image_params = optarg;
+				break;
+
 			case 'b':
 				int block_size;
 				if (!GetAsInt(optarg, block_size)) {
@@ -632,6 +653,10 @@ int main(int argc, char* argv[])
 			CommandReserve(hostname, port, reserved_ids);
 			exit(EXIT_SUCCESS);
 
+		case CREATE_IMAGE:
+			CommandCreateImage(hostname, port, image_params);
+			exit(EXIT_SUCCESS);
+
 		case DEVICE_INFO:
 			CommandDeviceInfo(hostname, port, command);
 			exit(EXIT_SUCCESS);