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-rw-r--r--mtab.c148
1 files changed, 148 insertions, 0 deletions
diff --git a/mtab.c b/mtab.c
new file mode 100644
index 0000000..b6304a1
--- /dev/null
+++ b/mtab.c
@@ -0,0 +1,148 @@
+#include "internal.h"
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+#include <mntent.h>
+#include <sys/mount.h>
+
+extern const char mtab_file[]; /* Defined in utility.c */
+
+static char *
+stralloc(const char * string)
+{
+ int length = strlen(string) + 1;
+ char * n = malloc(length);
+ memcpy(n, string, length);
+ return n;
+}
+
+extern void
+erase_mtab(const char * name)
+{
+ struct mntent entries[20];
+ int count = 0;
+ FILE *mountTable = setmntent(mtab_file, "r");
+ struct mntent * m;
+
+ if ( mountTable == 0
+ && (mountTable = setmntent("/proc/mounts", "r")) == 0 ) {
+ perror(mtab_file);
+ return;
+ }
+
+ while ( (m = getmntent(mountTable)) != 0 ) {
+ entries[count].mnt_fsname = stralloc(m->mnt_fsname);
+ entries[count].mnt_dir = stralloc(m->mnt_dir);
+ entries[count].mnt_type = stralloc(m->mnt_type);
+ entries[count].mnt_opts = stralloc(m->mnt_opts);
+ entries[count].mnt_freq = m->mnt_freq;
+ entries[count].mnt_passno = m->mnt_passno;
+ count++;
+ }
+ endmntent(mountTable);
+ if ( (mountTable = setmntent(mtab_file, "w")) ) {
+ int i;
+ for ( i = 0; i < count; i++ ) {
+ int result = ( strcmp(entries[i].mnt_fsname, name) == 0
+ || strcmp(entries[i].mnt_dir, name) == 0 );
+
+ if ( result )
+ continue;
+ else
+ addmntent(mountTable, &entries[i]);
+ }
+ endmntent(mountTable);
+ }
+ else if ( errno != EROFS )
+ perror(mtab_file);
+}
+
+/*
+ * Given a block device, find the mount table entry if that block device
+ * is mounted.
+ *
+ * Given any other file (or directory), find the mount table entry for its
+ * filesystem.
+ */
+static struct mntent *
+findMountPoint(const char * name, const char * table)
+{
+ struct stat s;
+ dev_t mountDevice;
+ FILE* mountTable;
+ struct mntent* mountEntry;
+
+ if ( stat(name, &s) != 0 )
+ return 0;
+
+ if ( (s.st_mode & S_IFMT) == S_IFBLK )
+ mountDevice = s.st_rdev;
+ else
+ mountDevice = s.st_dev;
+
+
+ if ( (mountTable = setmntent(table, "r")) == 0 )
+ return 0;
+
+ while ( (mountEntry = getmntent(mountTable)) != 0 ) {
+ if ( strcmp(name, mountEntry->mnt_dir) == 0 ||
+ strcmp(name, mountEntry->mnt_fsname) == 0 ) /* String match. */
+ break;
+ if ( stat(mountEntry->mnt_fsname, &s) == 0 &&
+ s.st_rdev == mountDevice ) /* Match the device. */
+ break;
+ if ( stat(mountEntry->mnt_dir, &s) == 0 &&
+ s.st_dev == mountDevice ) /* Match the directory's mount point. */
+ break;
+ }
+ endmntent(mountTable);
+ return mountEntry;
+}
+
+extern void
+write_mtab(char* blockDevice, char* directory,
+ char* filesystemType, long flags, char* string_flags)
+{
+ FILE *mountTable = setmntent(mtab_file, "a+");
+ struct mntent m;
+
+ if ( mountTable == 0 ) {
+ perror(mtab_file);
+ return;
+ }
+ if (mountTable) {
+ int length = strlen(directory);
+
+ if ( length > 1 && directory[length - 1] == '/' )
+ directory[length - 1] = '\0';
+
+ if ( filesystemType == 0 ) {
+ struct mntent * p
+ = findMountPoint(blockDevice, "/proc/mounts");
+
+ if ( p && p->mnt_type )
+ filesystemType = p->mnt_type;
+ }
+ m.mnt_fsname = blockDevice;
+ m.mnt_dir = directory;
+ m.mnt_type = filesystemType ? filesystemType : "default";
+
+ if (*string_flags) {
+ m.mnt_opts = string_flags;
+ } else {
+ if ( (flags | MS_RDONLY) == flags )
+ m.mnt_opts = "ro";
+ else
+ m.mnt_opts = "rw";
+ }
+
+ m.mnt_freq = 0;
+ m.mnt_passno = 0;
+ addmntent(mountTable, &m);
+ endmntent(mountTable);
+ }
+}
+
+