gserv.c

openGFS , a kind of file system.

/*
 *
 *    Copyright 2000-2001 Sistina Software, Inc.
 *    Portions Copyright 2001 The OpenGFS Project
 *
 *    This is free software released under the GNU General Public License.
 *    There is no warranty for this software.  See the file COPYING for
 *    details.
 *
 *    See the file AUTHORS for a list of contributors.
 *
 */

/*
 * This is a user level interface for setting up and configuring the
 * kgnbd kernel server.  Soon it will also be able to interface the 
 * gnbdd user level server.
 */

/*
 * AUDIT: <Alan>
 *	- Fixed multiple local possible buffer overruns, nothing serious
 *	- Fixed malloc checks
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <getopt.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <errno.h>
#include <limits.h>
#include <ctype.h>

int kernel_server;
int fd;
int read_fd;
int message_flag = 1;

#define printm(fmt, args...)\
{\
	if(message_flag != 0) \
		fprintf(stderr, "gserv: " fmt, ##args); \
}


size_t gserv_read(void *buf, size_t count)
{
	if (kernel_server)
		return read(fd, buf, count);
	return read(read_fd, buf, count);
}

size_t gserv_write(const void *buf, size_t count)
{
	return write(fd, buf, count);
}

int get_fd(int flags)
{
	fd = open("/proc/kgnbd", flags);
	if (fd < 0 && errno != ENOENT) {
		fprintf(stderr, "could not open /proc/kgnbd: %s\n",
			strerror(errno));
		return -1;
	}
	if (fd >= 0) {
		kernel_server = 1;
		return 0;
	}
	if ((flags & O_ACCMODE) == O_WRONLY) {
		fd = open("/dev/gnbd_rdpipe", flags);
		if (fd < 0) {
			fprintf(stderr,
				"couldn't connect to gnbd_rdpipe: %s\n",
				strerror(errno));
			return -1;
		}
	}
	if ((flags & O_ACCMODE) == O_RDONLY) {
		read_fd = open("/dev/gnbd_wrpipe", flags);
		if (read_fd < 0) {
			fprintf(stderr,
				"couldn't connect to gnbd_wrpipe: %s\n",
				strerror(errno));
			return -1;
		}
	}
	kernel_server = 0;
	return 0;
}


int servcreate(char *filename, char *pathname)
{
	int len = strlen(filename) + strlen(pathname) + 9;
	char *buf = (char *) malloc(len * sizeof(char));
	if(buf == NULL)
		exit(1);
	snprintf(buf, len, "create/%s/%s", filename, pathname);
	if (write(fd, buf, len) != len) {
		fprintf(stderr, "create request failed: %s\n",
			strerror(errno));
		free(buf);
		return 1;
	}
	free(buf);
	printm("created GNBD %s serving file %s\n", filename, pathname);
	return 0;
}

int servremove(char *filename)
{
	int len = strlen(filename) + 8;
	char *buf = (char *) malloc(len * sizeof(char));
	if(!buf)
		exit(1);
	snprintf(buf, len, "remove/%s", filename);
	if (gserv_write(buf, len) != len) {
		fprintf(stderr, "remove request failed: %s\n",
			strerror(errno));
		free(buf);
		return 1;
	}
	free(buf);
	printm("removed GNBD %s\n", filename);
	return 0;
}

int removeall(void)
{
	int bytes, total = 0;
	char *serv, *bufptr;
	char buf[4096];
	while ((bytes = gserv_read(buf + total, 4096 - total)) != 0) {
		if (bytes < 0 && errno != -EINTR) {
			fprintf(stderr, "remove request failed: %s\n",
				strerror(errno));
			return 1;
		}
		total += bytes;
	}
	if (total < 4096)
		buf[total] = 0;
	else
		buf[total] = 0;
	bufptr = buf;
	while ((serv = strchr(bufptr, '/')) != NULL) {
		serv++;
		bufptr = strchr(serv, '/');
		*bufptr++ = 0;
		bufptr = strstr(bufptr, "blocksize");
		servremove(serv);
		if (bufptr == NULL) {
			fprintf(stderr,
				"incorrectly formatted serverlist\n");
			return 1;
		}
	}
	return 0;
}

int portstop(void)
{
	char *buf = "portstop";
	if (gserv_write(buf, 9) != 9) {
		fprintf(stderr, "stop kgnbd_portd request failed: %s\n",
			strerror(errno));
		return 1;
	}
	printm("kgnbd_portd stopped\n");
	return 0;
}

int portstart(unsigned int port)
{
	int len;
	char buf[16];
	if (port != 0)
		snprintf(buf, 16, "portstart/%u", port);
	else
		snprintf(buf, 16, "portstart");
	len = strlen(buf);
	if (gserv_write(buf, len + 1) != len + 1) {
		fprintf(stderr, "start kgnbd_portd request failed: %s\n",
			strerror(errno));
		return 1;
	}
	printm("kgnbd_portd started\n");
	return 0;
}

int list(void)
{
	int n;
	int bytes = 0;
	char *serv;
	char buf[4096];
	char *bufptr = buf;
	while ((n = gserv_read(buf + bytes, 4096 - bytes)) != 0) {
		if (n < 0 && errno != -EINTR) {
			fprintf(stderr, "list request failed: %s\n",
				strerror(errno));
			return 1;
		}
		bytes += n;
	}
	if (bytes < 4096)
		buf[bytes] = 0;
	else
		buf[4095] = 0;
	bufptr = strchr(buf, '\n');
	*bufptr = 0;
	bufptr = bufptr + 2;
	printf("%s\n\n", buf);
	if (strncmp(bufptr, "no", 2) == 0) {
		serv = strchr(bufptr, '\n');
		*serv = 0;
		printf("%s\n", bufptr);
		return 0;
	}
	while ((serv = strstr(bufptr, "Server")) != NULL) {
		bufptr = strchr(serv, '/');
		*bufptr++ = ' ';
		bufptr = strchr(bufptr, '/');
		*bufptr++ = ' ';
		bufptr = strstr(serv, "\n       pid");
		*bufptr++ = 0;
		printf("%s\n\n", serv);
	}
	return 0;
}

int usage(void)
{
	printf("Usage:\n\n");

	printf("gserv [-q] <GNBD> <device or file>\n");
	printf
	    ("    Create and export new GNBD from named device or file.\n\n");

	printf("gserv [-q] -r <GNBD>\n");
	printf("    Remove (un-export) named GNBD.\n\n");

	printf("gserv -l\n");
	printf("    List exported GNBD's and kgnbd_portd server.\n\n");

	printf("gserv [-q] -p [<port>]\n");
	printf("    Start the kgnbd_portd server (default 14243).\n\n");

	printf("gserv [-q] -s\n");
	printf("    Stop the current kgnbd_portd server.\n\n");

	printf("gserv -h\n");
	printf("    Print help.\n\n");

	printf("-q toggles gserv to quiet mode, so it does not print on "
	       "success\n\n");

#if 0
	printf("Create an new kgnbd server for a file or block device\n"
	       "   gserv <server name> <file or device>\n");
	printf("Remove a kgnbd server\n" "   gserv -r <server name>\n");
	printf("List the kgnbd and kgnbd_portd servers currently running\n"
	       "   gserv -l\n");
	printf
	    ("Start up the kgnbd_portd server (if no port is specified, the default is 14243)\n"
	     "   gserv -p [<server port>]\n");
	printf("Stop the current kgnbd_portd server\n" "   gserv -s\n");
	printf("Print this message\n" "   gserv -h\n\n");
#endif
	return 1;
}


int main(int argc, char **argv)
{
	int c;
	int i;
	char *tailptr;
	unsigned long int port = 0;
	if (argc < 2) {
		return usage();
	}
loop:
	c = getopt(argc, argv, "qlrpsh");
	switch (c) {
	case 'q':
		message_flag = 0;
		goto loop;
	case -1:
		if (argc - optind != 2)
			return usage();
		if (get_fd(O_WRONLY) < 0)
			return 1;
		return servcreate(argv[optind], argv[optind + 1]);
	case 'l':
		if (optind != argc) {
			fprintf(stderr,
				"unnecessary argument after list request: %s\n\n",
				argv[optind]);
			return usage();
		}
		if (get_fd(O_RDONLY) < 0)
			return 1;
		return list();
	case 'r':
		if (get_fd(O_RDWR) < 0)
			return 1;
		if (optind == argc)
			return removeall();
		for (i = optind; i < argc; i++)
			if (servremove(argv[i]) != 0) {
				fprintf(stderr, "couldn't remove %s: %s\n",
					argv[i], strerror(errno));
				return 1;
			}
		return 0;
	case 'p':
		if (argc != optind) {
			fprintf(stderr,
				"unnecessary argument to kgnbd_portd request\n\n");
			return usage();
		}
		/*
		   if (argc - optind > 1){
		   fprintf(stderr, "unnecessary argument after port number\n\n");
		   return usage();
		   }
		 */
		if (argc == optind)
			port = 0;
		else {
			port = strtoul(argv[optind], &tailptr, 0);
			if (port <= 0 || *tailptr != 0 || port > 65536) {
				fprintf(stderr,
					"invalid port number: %s\n\n",
					argv[optind]);
				return usage();
			}
		}
		if (get_fd(O_WRONLY) < 0)
			return 1;
		return portstart((unsigned int) port);
	case 's':
		if (optind != argc) {
			fprintf(stderr,
				"unnecessary argument to stop kgnbd_portd "
				"request\n\n");
			return usage();
		}
		if (get_fd(O_WRONLY) < 0)
			return 1;
		return portstop();
	case '?':
		if (isprint(optopt))
			fprintf(stderr, "Unknown option: -%c\n\n", optopt);
		else
			fprintf(stderr, "Unknown option\n\n");
		return usage();
	case 'h':
	default:
		return usage();
	}
}