-#include "internal.h"
-/*
- * mkswap.c - set up a linux swap device
- *
- * (C) 1991 Linus Torvalds. This file may be redistributed as per
- * the Linux copyright.
- */
-
-/*
- * 20.12.91 - time began. Got VM working yesterday by doing this by hand.
- *
- * Usage: mkswap [-c] device [size-in-blocks]
- *
- * -c for readablility checking (use it unless you are SURE!)
+/* vi: set sw=4 ts=4: */
+/* mkswap.c - format swap device (Linux v1 only)
*
- * The device may be a block device or a image of one, but this isn't
- * enforced (but it's not much fun on a character device :-).
+ * Copyright 2006 Rob Landley <rob@landley.net>
*
- * Patches from jaggy@purplet.demon.co.uk (Mike Jagdis) to make the
- * size-in-blocks parameter optional added Wed Feb 8 10:33:43 1995.
+ * Licensed under GPL version 2, see file LICENSE in this tarball for details.
*/
-#include <stdio.h>
-#include <unistd.h>
-#include <string.h>
-#include <fcntl.h>
-#include <stdlib.h>
-#include <sys/stat.h>
-#include <sys/ioctl.h>
-
-#include <asm/page.h>
-#include <linux/fs.h>
-
-#ifndef __linux__
-# define volatile
-#endif
-
-#define TEST_BUFFER_PAGES 8
-
-const char mkswap_usage[] = "mkswap [-c] partition [block-count]\n"
-"\n"
-"\tPrepare a disk partition to be used as a swap partition.\n"
-"\tThe default block count is the size of the entire partition.\n"
-"\n"
-"\t-c:\tCheck for read-ability.\n"
-"\tblock-count\tUse only this many blocks.\n";
-
-static const char * program_name = "mkswap";
-static const char * device_name = NULL;
-static int DEV = -1;
-static long PAGES = 0;
-static int do_check = 0;
-static int badpages = 0;
+#include "libbb.h"
-
-static long bit_test_and_set (unsigned int *addr, unsigned int nr)
-{
- unsigned int r, m;
-
- addr += nr / (8 * sizeof(int));
- r = *addr;
- m = 1 << (nr & (8 * sizeof(int) - 1));
- *addr = r | m;
- return (r & m) != 0;
-}
-
-static int bit_test_and_clear (unsigned int *addr, unsigned int nr)
+#if ENABLE_SELINUX
+static void mkswap_selinux_setcontext(int fd, const char *path)
{
- unsigned int r, m;
-
- addr += nr / (8 * sizeof(int));
- r = *addr;
- m = 1 << (nr & (8 * sizeof(int) - 1));
- *addr = r & ~m;
- return (r & m) != 0;
+ struct stat stbuf;
+
+ if (!is_selinux_enabled())
+ return;
+
+ if (fstat(fd, &stbuf) < 0)
+ bb_perror_msg_and_die("fstat failed");
+ if (S_ISREG(stbuf.st_mode)) {
+ security_context_t newcon;
+ security_context_t oldcon = NULL;
+ context_t context;
+
+ if (fgetfilecon(fd, &oldcon) < 0) {
+ if (errno != ENODATA)
+ goto error;
+ if (matchpathcon(path, stbuf.st_mode, &oldcon) < 0)
+ goto error;
+ }
+ context = context_new(oldcon);
+ if (!context || context_type_set(context, "swapfile_t"))
+ goto error;
+ newcon = context_str(context);
+ if (!newcon)
+ goto error;
+ /* fsetfilecon_raw is hidden */
+ if (strcmp(oldcon, newcon) != 0 && fsetfilecon(fd, newcon) < 0)
+ goto error;
+ if (ENABLE_FEATURE_CLEAN_UP) {
+ context_free(context);
+ freecon(oldcon);
+ }
+ }
+ return;
+ error:
+ bb_perror_msg_and_die("SELinux relabeling failed");
}
+#else
+#define mkswap_selinux_setcontext(fd, path) ((void)0)
+#endif
+#if 0 /* from Linux 2.6.23 */
/*
- * Volatile to let gcc know that this doesn't return. When trying
- * to compile this under minix, volatile gives a warning, as
- * exit() isn't defined as volatile under minix.
+ * Magic header for a swap area. The first part of the union is
+ * what the swap magic looks like for the old (limited to 128MB)
+ * swap area format, the second part of the union adds - in the
+ * old reserved area - some extra information. Note that the first
+ * kilobyte is reserved for boot loader or disk label stuff...
*/
-volatile void fatal_error(const char * fmt_string)
-{
- fprintf(stderr,fmt_string,program_name,device_name);
- exit(1);
-}
+union swap_header {
+ struct {
+ char reserved[PAGE_SIZE - 10];
+ char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
+ } magic;
+ struct {
+ char bootbits[1024]; /* Space for disklabel etc. */
+ __u32 version; /* second kbyte, word 0 */
+ __u32 last_page; /* 1 */
+ __u32 nr_badpages; /* 2 */
+ unsigned char sws_uuid[16]; /* 3,4,5,6 */
+ unsigned char sws_volume[16]; /* 7,8,9,10 */
+ __u32 padding[117]; /* 11..127 */
+ __u32 badpages[1]; /* 128, total 129 32-bit words */
+ } info;
+};
+#endif
-#define die(str) fatal_error("%s: " str "\n")
+#define NWORDS 129
+#define hdr ((uint32_t*)(&bb_common_bufsiz1))
-static void check_blocks(int * signature_page)
-{
- unsigned int current_page;
- int do_seek = 1;
- char buffer[PAGE_SIZE];
-
- current_page = 0;
- while (current_page < PAGES) {
- if (!do_check) {
- bit_test_and_set(signature_page,current_page++);
- continue;
- } else {
- printf("\r%d", current_page);
- }
- if (do_seek && lseek(DEV,current_page*PAGE_SIZE,SEEK_SET) !=
- current_page*PAGE_SIZE)
- die("seek failed in check_blocks");
- if ( (do_seek = (PAGE_SIZE != read(DEV, buffer, PAGE_SIZE))) ) {
- bit_test_and_clear(signature_page,current_page++);
- badpages++;
- continue;
- }
- bit_test_and_set(signature_page,current_page++);
- }
- if (do_check)
- printf("\n");
- if (badpages)
- printf("%d bad page%s\n",badpages,(badpages>1)?"s":"");
-}
+struct BUG_bufsiz1_is_too_small {
+ char BUG_bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
+};
+
+/* Stored without terminating NUL */
+static const char SWAPSPACE2[sizeof("SWAPSPACE2")-1] ALIGN1 = "SWAPSPACE2";
-static long valid_offset (int fd, int offset)
+int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int mkswap_main(int argc, char **argv)
{
- char ch;
+ int fd, pagesize;
+ off_t len;
- if (lseek (fd, offset, 0) < 0)
- return 0;
- if (read (fd, &ch, 1) < 1)
- return 0;
- return 1;
-}
+ // No options supported.
-static int count_blocks (int fd)
-{
- int high, low;
-
- low = 0;
- for (high = 1; valid_offset (fd, high); high *= 2)
- low = high;
- while (low < high - 1)
- {
- const int mid = (low + high) / 2;
-
- if (valid_offset (fd, mid))
- low = mid;
- else
- high = mid;
- }
- valid_offset (fd, 0);
- return (low + 1);
-}
+ if (argc != 2) bb_show_usage();
-static int get_size(const char *file)
-{
- int fd;
- int size;
+ // Figure out how big the device is and announce our intentions.
- fd = open(file, O_RDWR);
- if (fd < 0) {
- perror(file);
- exit(1);
- }
- if (ioctl(fd, BLKGETSIZE, &size) >= 0) {
- close(fd);
- return (size * 512);
- }
-
- size = count_blocks(fd);
- close(fd);
- return size;
-}
+ fd = xopen(argv[1], O_RDWR);
+ /* fdlength was reported to be unreliable - use seek */
+ len = xlseek(fd, 0, SEEK_END);
+#if ENABLE_SELINUX
+ xlseek(fd, 0, SEEK_SET);
+#endif
+ pagesize = getpagesize();
+ printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n",
+ len - pagesize);
+ mkswap_selinux_setcontext(fd, argv[1]);
-int
-mkswap(char *device_name, int pages, int check)
- {
- struct stat statbuf;
- int goodpages;
- int signature_page[PAGE_SIZE/sizeof(int)];
+ // Make a header. hdr is zero-filled so far...
+ hdr[0] = 1;
+ hdr[1] = (len / pagesize) - 1;
- PAGES = pages;
- do_check = check;
+ // Write the header. Sync to disk because some kernel versions check
+ // signature on disk (not in cache) during swapon.
- memset(signature_page,0,PAGE_SIZE);
+ xlseek(fd, 1024, SEEK_SET);
+ xwrite(fd, hdr, NWORDS * 4);
+ xlseek(fd, pagesize - 10, SEEK_SET);
+ xwrite(fd, SWAPSPACE2, 10);
+ fsync(fd);
- if (device_name && !PAGES) {
- PAGES = get_size(device_name) / PAGE_SIZE;
- }
- if (!device_name || PAGES<10) {
- fprintf(stderr,
- "%s: error: swap area needs to be at least %ldkB\n",
- program_name, 10 * PAGE_SIZE / 1024);
- /* usage(mkswap_usage); */
- exit(1);
- }
- if (PAGES > 8 * (PAGE_SIZE - 10)) {
- PAGES = 8 * (PAGE_SIZE - 10);
- fprintf(stderr, "%s: warning: truncating swap area to %ldkB\n",
- program_name, PAGES * PAGE_SIZE / 1024);
- }
- DEV = open(device_name,O_RDWR);
- if (DEV < 0 || fstat(DEV, &statbuf) < 0) {
- perror(device_name);
- exit(1);
- }
- if (!S_ISBLK(statbuf.st_mode))
- do_check=0;
- else if (statbuf.st_rdev == 0x0300 || statbuf.st_rdev == 0x0340)
- die("Will not try to make swapdevice on '%s'");
- check_blocks(signature_page);
- if (!bit_test_and_clear(signature_page,0))
- die("fatal: first page unreadable");
- goodpages = PAGES - badpages - 1;
- if (goodpages <= 0)
- die("Unable to set up swap-space: unreadable");
- printf("Setting up swapspace, size = %ld bytes\n",goodpages*PAGE_SIZE);
- strncpy((char*)signature_page+PAGE_SIZE-10,"SWAP-SPACE",10);
- if (lseek(DEV, 0, SEEK_SET))
- die("unable to rewind swap-device");
- if (PAGE_SIZE != write(DEV, signature_page, PAGE_SIZE))
- die("unable to write signature page");
-
- close(DEV);
- return 0;
-}
+ if (ENABLE_FEATURE_CLEAN_UP) close(fd);
-int mkswap_main(struct FileInfo * unnecessary, int argc, char ** argv)
-{
- char * tmp;
- long int pages=0;
- int check=0;
-
- if (argc && *argv)
- program_name = *argv;
- while (argc > 1) {
- argv++;
- argc--;
- if (argv[0][0] != '-')
- if (device_name) {
- pages = strtol(argv[0],&tmp,0)>>(PAGE_SHIFT-10);
- if (*tmp) {
- usage(mkswap_usage);
- exit(1);
- }
- } else
- device_name = argv[0];
- else while (*++argv[0])
- switch (argv[0][0]) {
- case 'c': check=1; break;
- default: usage(mkswap_usage);
- exit(1);
- }
- }
- return mkswap(device_name, pages, check);
+ return 0;
}
projects / oweals / busybox.git / blobdiff