flock: should not be selected by default

[oweals/busybox.git] / util-linux / mkswap.c

diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c
index 7baa3ecfb4ecef55b9ddd87eaa2f7d6ceffa5a5b..7e32d91edba94396543a4b03471e83dfbaca0edc 100644 (file)
--- a/util-linux/mkswap.c
+++ b/util-linux/mkswap.c
@@ -5,43 +5,132 @@
  *
  * Licensed under GPL version 2, see file LICENSE in this tarball for details.
  */
+#include "libbb.h"
 
-#include "busybox.h"
+#if ENABLE_SELINUX
+static void mkswap_selinux_setcontext(int fd, const char *path)
+{
+       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;
 
-int mkswap_main(int argc, char *argv[])
+               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
+
+/* from Linux 2.6.23 */
+/*
+ * Magic header for a swap area. ... Note that the first
+ * kilobyte is reserved for boot loader or disk label stuff.
+ */
+struct swap_header_v1 {
+/*     char     bootbits[1024];    Space for disklabel etc. */
+       uint32_t version;        /* second kbyte, word 0 */
+       uint32_t last_page;      /* 1 */
+       uint32_t nr_badpages;    /* 2 */
+       char     sws_uuid[16];   /* 3,4,5,6 */
+       char     sws_volume[16]; /* 7,8,9,10 */
+       uint32_t padding[117];   /* 11..127 */
+       uint32_t badpages[1];    /* 128 */
+       /* total 129 32-bit words in 2nd kilobyte */
+} FIX_ALIASING;
+
+#define NWORDS 129
+#define hdr ((struct swap_header_v1*)bb_common_bufsiz1)
+
+struct BUG_sizes {
+       char swap_header_v1_wrong[sizeof(*hdr)  != (NWORDS * 4) ? -1 : 1];
+       char bufsiz1_is_too_small[COMMON_BUFSIZE < (NWORDS * 4) ? -1 : 1];
+};
+
+/* Stored without terminating NUL */
+static const char SWAPSPACE2[sizeof("SWAPSPACE2")-1] ALIGN1 = "SWAPSPACE2";
+
+int mkswap_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int mkswap_main(int argc UNUSED_PARAM, char **argv)
 {
-       int fd, pagesize;
+       int fd;
+       unsigned pagesize;
        off_t len;
-       unsigned int hdr[129];
-
-       // No options supported.
+       const char *label = "";
 
-       if (argc != 2) bb_show_usage();
+       opt_complementary = "-1"; /* at least one param */
+       /* TODO: -p PAGESZ, -U UUID */
+       getopt32(argv, "L:", &label);
+       argv += optind;
 
-       // Figure out how big the device is and announce our intentions.
+       fd = xopen(argv[0], O_WRONLY);
 
-       fd = xopen(argv[1], O_RDWR);
-       len = fdlength(fd);
+       /* Figure out how big the device is */
+       len = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ 1);
        pagesize = getpagesize();
-       printf("Setting up swapspace version 1, size = %"OFF_FMT"d bytes\n",
-                       len - pagesize);
+       len -= pagesize;
 
-       // Make a header.
+       /* Announce our intentions */
+       printf("Setting up swapspace version 1, size = %"OFF_FMT"u bytes\n", len);
+       mkswap_selinux_setcontext(fd, argv[0]);
 
-       memset(hdr, 0, sizeof(hdr));
-       hdr[0] = 1;
-       hdr[1] = (len / pagesize) - 1;
+       /* Make a header. hdr is zero-filled so far... */
+       hdr->version = 1;
+       hdr->last_page = (uoff_t)len / pagesize;
 
-       // Write the header.  Sync to disk because some kernel versions check
-       // signature on disk (not in cache) during swapon.
+       if (ENABLE_FEATURE_MKSWAP_UUID) {
+               char uuid_string[32];
+               generate_uuid((void*)hdr->sws_uuid);
+               bin2hex(uuid_string, hdr->sws_uuid, 16);
+               /* f.e. UUID=dfd9c173-be52-4d27-99a5-c34c6c2ff55f */
+               printf("UUID=%.8s"  "-%.4s-%.4s-%.4s-%.12s\n",
+                       uuid_string,
+                       uuid_string+8,
+                       uuid_string+8+4,
+                       uuid_string+8+4+4,
+                       uuid_string+8+4+4+4
+               );
+       }
+       safe_strncpy(hdr->sws_volume, label, 16);
 
+       /* Write the header.  Sync to disk because some kernel versions check
+        * signature on disk (not in cache) during swapon. */
        xlseek(fd, 1024, SEEK_SET);
-       xwrite(fd, hdr, sizeof(hdr));
-       xlseek(fd, pagesize-10, SEEK_SET);
-       xwrite(fd, "SWAPSPACE2", 10);
+       xwrite(fd, hdr, NWORDS * 4);
+       xlseek(fd, pagesize - 10, SEEK_SET);
+       xwrite(fd, SWAPSPACE2, 10);
        fsync(fd);
 
-       if (ENABLE_FEATURE_CLEAN_UP) close(fd);
+       if (ENABLE_FEATURE_CLEAN_UP)
+               close(fd);
 
        return 0;
 }