libmount/src/mountP.h

   1 /*
   2  * mountP.h - private library header file
   3  *
   4  * Copyright (C) 2008-2009 Karel Zak <kzak@redhat.com>
   5  *
   6  * This file may be redistributed under the terms of the
   7  * GNU Lesser General Public License.
   8  */
   9
  10 #ifndef _LIBMOUNT_PRIVATE_H
  11 #define _LIBMOUNT_PRIVATE_H
  12
  13 #include <errno.h>
  14 #include <stdlib.h>
  15 #include <string.h>
  16 #include <sys/stat.h>
  17 #include <sys/types.h>
  18 #include <unistd.h>
  19
  20 #include "c.h"
  21 #include "list.h"
  22 #include "libmount.h"
  23
  24 /* features */
  25 #define CONFIG_LIBMOUNT_ASSERT
  26 #define CONFIG_LIBMOUNT_DEBUG
  27
  28 #ifdef CONFIG_LIBMOUNT_ASSERT
  29 #include <assert.h>
  30 #endif
  31
  32 /*
  33  * Debug
  34  */
  35 #if defined(TEST_PROGRAM) && !defined(LIBMOUNT_DEBUG)
  36 #define CONFIG_LIBMOUNT_DEBUG
  37 #endif
  38
  39 #define MNT_DEBUG_INIT          (1 << 1)
  40 #define MNT_DEBUG_CACHE         (1 << 2)
  41 #define MNT_DEBUG_OPTIONS       (1 << 3)
  42 #define MNT_DEBUG_LOCKS         (1 << 4)
  43 #define MNT_DEBUG_TAB           (1 << 5)
  44 #define MNT_DEBUG_FS            (1 << 6)
  45 #define MNT_DEBUG_OPTS          (1 << 7)
  46 #define MNT_DEBUG_UPDATE        (1 << 8)
  47 #define MNT_DEBUG_UTILS         (1 << 9)
  48 #define MNT_DEBUG_CXT           (1 << 10)
  49 #define MNT_DEBUG_DIFF          (1 << 11)
  50 #define MNT_DEBUG_ALL           0xFFFF
  51
  52 #ifdef CONFIG_LIBMOUNT_DEBUG
  53 # include <stdio.h>
  54 # include <stdarg.h>
  55
  56 # define ON_DBG(m, x)   do { \
  57                                 if ((MNT_DEBUG_ ## m) & libmount_debug_mask) { \
  58                                         x; \
  59                                 } \
  60                         } while (0)
  61
  62 # define DBG(m, x)      do { \
  63                                 if ((MNT_DEBUG_ ## m) & libmount_debug_mask) { \
  64                                         fprintf(stderr, "%d: libmount: %8s: ", getpid(), # m); \
  65                                         x; \
  66                                 } \
  67                         } while (0)
  68
  69 # define DBG_FLUSH      do { \
  70                                 if (libmount_debug_mask && \
  71                                     libmount_debug_mask != MNT_DEBUG_INIT) \
  72                                         fflush(stderr); \
  73                         } while(0)
  74
  75 extern int libmount_debug_mask;
  76
  77 static inline void __attribute__ ((__format__ (__printf__, 1, 2)))
  78 mnt_debug(const char *mesg, ...)
  79 {
  80         va_list ap;
  81         va_start(ap, mesg);
  82         vfprintf(stderr, mesg, ap);
  83         va_end(ap);
  84         fputc('\n', stderr);
  85 }
  86
  87 static inline void __attribute__ ((__format__ (__printf__, 2, 3)))
  88 mnt_debug_h(void *handler, const char *mesg, ...)
  89 {
  90         va_list ap;
  91
  92         fprintf(stderr, "[%p]: ", handler);
  93         va_start(ap, mesg);
  94         vfprintf(stderr, mesg, ap);
  95         va_end(ap);
  96         fputc('\n', stderr);
  97 }
  98
  99 #else /* !CONFIG_LIBMOUNT_DEBUG */
 100 # define ON_DBG(m,x) do { ; } while (0)
 101 # define DBG(m,x) do { ; } while (0)
 102 # define DBG_FLUSH do { ; } while(0)
 103 #endif
 104
 105 /* extension for files in the directory */
 106 #define MNT_MNTTABDIR_EXT       ".fstab"
 107
 108 /* library private paths */
 109 #define MNT_RUNTIME_TOPDIR      "/run"
 110 #define MNT_RUNTIME_TOPDIR_OLD  "/dev"
 111
 112 #define MNT_PATH_UTAB           MNT_RUNTIME_TOPDIR "/mount/utab"
 113 #define MNT_PATH_UTAB_OLD       MNT_RUNTIME_TOPDIR_OLD "/.mount/utab"
 114
 115 #define MNT_UTAB_HEADER "# libmount utab file\n"
 116
 117 #ifdef TEST_PROGRAM
 118 struct libmnt_test {
 119         const char      *name;
 120         int             (*body)(struct libmnt_test *ts, int argc, char *argv[]);
 121         const char      *usage;
 122 };
 123
 124 /* test.c */
 125 extern int mnt_run_test(struct libmnt_test *tests, int argc, char *argv[]);
 126 #endif
 127
 128 /* utils.c */
 129 extern int endswith(const char *s, const char *sx);
 130 extern int startswith(const char *s, const char *sx);
 131
 132 extern int mnt_is_readonly(const char *path);
 133
 134 extern int mnt_parse_offset(const char *str, size_t len, uintmax_t *res);
 135
 136 extern int mnt_chdir_to_parent(const char *target, char **filename);
 137 extern char *mnt_get_username(const uid_t uid);
 138 extern int mnt_get_uid(const char *username, uid_t *uid);
 139 extern int mnt_get_gid(const char *groupname, gid_t *gid);
 140 extern int mnt_in_group(gid_t gid);
 141
 142 extern char *mnt_get_mountpoint(const char *path);
 143 extern char *mnt_get_fs_root(const char *path, const char *mountpoint);
 144 extern int mnt_open_uniq_filename(const char *filename, char **name);
 145 extern int mnt_has_regular_utab(const char **utab, int *writable);
 146 extern const char *mnt_get_utab_path(void);
 147
 148 extern int mnt_get_filesystems(char ***filesystems, const char *pattern);
 149 extern void mnt_free_filesystems(char **filesystems);
 150
 151 /* tab.c */
 152 extern struct libmnt_fs *mnt_table_get_fs_root(struct libmnt_table *tb,
 153                                         struct libmnt_fs *fs,
 154                                         unsigned long mountflags,
 155                                         char **fsroot);
 156
 157 /*
 158  * Generic iterator
 159  */
 160 struct libmnt_iter {
 161         struct list_head        *p;             /* current position */
 162         struct list_head        *head;          /* start position */
 163         int                     direction;      /* MNT_ITER_{FOR,BACK}WARD */
 164 };
 165
 166 #define IS_ITER_FORWARD(_i)     ((_i)->direction == MNT_ITER_FORWARD)
 167 #define IS_ITER_BACKWARD(_i)    ((_i)->direction == MNT_ITER_BACKWARD)
 168
 169 #define MNT_ITER_INIT(itr, list) \
 170         do { \
 171                 (itr)->p = IS_ITER_FORWARD(itr) ? \
 172                                 (list)->next : (list)->prev; \
 173                 (itr)->head = (list); \
 174         } while(0)
 175
 176 #define MNT_ITER_ITERATE(itr, res, restype, member) \
 177         do { \
 178                 res = list_entry((itr)->p, restype, member); \
 179                 (itr)->p = IS_ITER_FORWARD(itr) ? \
 180                                 (itr)->p->next : (itr)->p->prev; \
 181         } while(0)
 182
 183
 184 /*
 185  * This struct represents one entry in mtab/fstab/mountinfo file.
 186  * (note that fstab[1] means the first column from fstab, and so on...)
 187  */
 188 struct libmnt_fs {
 189         struct list_head ents;
 190
 191         int             id;             /* mountinfo[1]: ID */
 192         int             parent;         /* mountinfo[2]: parent */
 193         dev_t           devno;          /* mountinfo[3]: st_dev */
 194
 195         char            *bindsrc;       /* utab, full path from fstab[1] for bind mounts */
 196
 197         char            *source;        /* fstab[1], mountinfo[10]:
 198                                          * source dev, file, dir or TAG */
 199         char            *tagname;       /* fstab[1]: tag name - "LABEL", "UUID", ..*/
 200         char            *tagval;        /*           tag value */
 201
 202         char            *root;          /* mountinfo[4]: root of the mount within the FS */
 203         char            *target;        /* mountinfo[5], fstab[2]: mountpoint */
 204         char            *fstype;        /* mountinfo[9], fstab[3]: filesystem type */
 205
 206         char            *optstr;        /* fstab[4], merged options */
 207         char            *vfs_optstr;    /* mountinfo[6]: fs-independent (VFS) options */
 208         char            *fs_optstr;     /* mountinfo[11]: fs-dependent options */
 209         char            *user_optstr;   /* userspace mount options */
 210         char            *attrs;         /* mount attributes */
 211
 212         int             freq;           /* fstab[5]: dump frequency in days */
 213         int             passno;         /* fstab[6]: pass number on parallel fsck */
 214
 215         int             flags;          /* MNT_FS_* flags */
 216
 217         void            *userdata;      /* library independent data */
 218 };
 219
 220 /*
 221  * fs flags
 222  */
 223 #define MNT_FS_PSEUDO   (1 << 1) /* pseudo filesystem */
 224 #define MNT_FS_NET      (1 << 2) /* network filesystem */
 225 #define MNT_FS_SWAP     (1 << 3) /* swap device */
 226 #define MNT_FS_KERNEL   (1 << 4) /* data from /proc/{mounts,self/mountinfo} */
 227 #define MNT_FS_MERGED   (1 << 5) /* already merged data from /run/mount/utab */
 228
 229 #define mnt_fs_is_regular(_f)   (!(mnt_fs_is_pseudofs(_f) \
 230                                    || mnt_fs_is_netfs(_f) \
 231                                    || mnt_fs_is_swaparea(_f)))
 232
 233 /*
 234  * mtab/fstab/mountinfo file
 235  */
 236 struct libmnt_table {
 237         int             fmt;            /* MNT_FMT_* file format */
 238         int             nents;          /* number of valid entries */
 239
 240         struct libmnt_cache *cache;             /* canonicalized paths/tags cache */
 241
 242         int             (*errcb)(struct libmnt_table *tb,
 243                                  const char *filename, int line);
 244
 245         struct list_head        ents;   /* list of entries (libmnt_fs) */
 246 };
 247
 248 extern struct libmnt_table *__mnt_new_table_from_file(const char *filename, int fmt);
 249
 250 /*
 251  * Tab file format
 252  */
 253 enum {
 254         MNT_FMT_GUESS,
 255         MNT_FMT_FSTAB,                  /* /etc/{fs,m}tab */
 256         MNT_FMT_MTAB = MNT_FMT_FSTAB,   /* alias */
 257         MNT_FMT_MOUNTINFO,              /* /proc/#/mountinfo */
 258         MNT_FMT_UTAB                    /* /dev/.mount/utab */
 259 };
 260
 261
 262 /*
 263  * Mount context -- high-level API
 264  */
 265 struct libmnt_context
 266 {
 267         int     action;         /* MNT_ACT_{MOUNT,UMOUNT} */
 268         int     restricted;     /* root or not? */
 269
 270         char    *fstype_pattern;        /* for mnt_match_fstype() */
 271         char    *optstr_pattern;        /* for mnt_match_options() */
 272
 273         struct libmnt_fs *fs;           /* filesystem description (type, mountpoint, device, ...) */
 274
 275         struct libmnt_table *fstab;     /* fstab (or mtab for some remounts) entries */
 276         struct libmnt_table *mtab;      /* mtab entries */
 277
 278         int     (*table_errcb)(struct libmnt_table *tb, /* callback for libmnt_table structs */
 279                          const char *filename, int line);
 280
 281         char    *(*pwd_get_cb)(struct libmnt_context *);                /* get encryption password */
 282         void    (*pwd_release_cb)(struct libmnt_context *, char *);     /* release password */
 283
 284         int     optsmode;       /* fstab optstr mode MNT_OPTSMODE_{AUTO,FORCE,IGNORE} */
 285         int     loopdev_fd;     /* open loopdev */
 286
 287         unsigned long   mountflags;     /* final mount(2) flags */
 288         const void      *mountdata;     /* final mount(2) data, string or binary data */
 289
 290         unsigned long   user_mountflags;        /* MNT_MS_* (loop=, user=, ...) */
 291
 292         struct libmnt_cache     *cache; /* paths cache */
 293         struct libmnt_lock      *lock;  /* mtab lock */
 294         struct libmnt_update    *update;/* mtab/utab update */
 295
 296         const char      *mtab_path; /* path to mtab */
 297         int             mtab_writable; /* is mtab writable */
 298
 299         const char      *utab_path; /* path to utab */
 300         int             utab_writable; /* is utab writable */
 301
 302         int     flags;          /* private context flags */
 303         int     ambi;           /* libblkid returns ambivalent result */
 304
 305         char    *helper;        /* name of the used /sbin/[u]mount.<type> helper */
 306         int     helper_status;  /* helper wait(2) status */
 307         int     helper_exec_status; /* 1: not called yet, 0: success, <0: -errno */
 308
 309         char    *orig_user;     /* original (non-fixed) user= option */
 310
 311         pid_t   *children;      /* "mount -a --fork" PIDs */
 312         int     nchildren;      /* number of children */
 313         pid_t   pid;            /* 0=parent; PID=child */
 314
 315
 316         int     syscall_status; /* 1: not called yet, 0: success, <0: -errno */
 317 };
 318
 319 /* flags */
 320 #define MNT_FL_NOMTAB           (1 << 1)
 321 #define MNT_FL_FAKE             (1 << 2)
 322 #define MNT_FL_SLOPPY           (1 << 3)
 323 #define MNT_FL_VERBOSE          (1 << 4)
 324 #define MNT_FL_NOHELPERS        (1 << 5)
 325 #define MNT_FL_LOOPDEL          (1 << 6)
 326 #define MNT_FL_LAZY             (1 << 7)
 327 #define MNT_FL_FORCE            (1 << 8)
 328 #define MNT_FL_NOCANONICALIZE   (1 << 9)
 329 #define MNT_FL_RDONLY_UMOUNT    (1 << 11)       /* remount,ro after EBUSY umount(2) */
 330 #define MNT_FL_FORK             (1 << 12)
 331
 332 #define MNT_FL_EXTERN_FS        (1 << 15)       /* cxt->fs is not private */
 333 #define MNT_FL_EXTERN_FSTAB     (1 << 16)       /* cxt->fstab is not private */
 334 #define MNT_FL_EXTERN_CACHE     (1 << 17)       /* cxt->cache is not private */
 335
 336 #define MNT_FL_MOUNTDATA        (1 << 20)
 337 #define MNT_FL_TAB_APPLIED      (1 << 21)       /* mtab/fstab merged to cxt->fs */
 338 #define MNT_FL_MOUNTFLAGS_MERGED (1 << 22)      /* MS_* flags was read from optstr */
 339 #define MNT_FL_SAVED_USER       (1 << 23)
 340 #define MNT_FL_PREPARED         (1 << 24)
 341 #define MNT_FL_HELPER           (1 << 25)       /* [u]mount.<type> */
 342 #define MNT_FL_LOOPDEV_READY    (1 << 26)       /* /dev/loop<N> initialized by library */
 343 #define MNT_FL_MOUNTOPTS_FIXED  (1 << 27)
 344
 345 /* default flags */
 346 #define MNT_FL_DEFAULT          0
 347
 348 /* lock.c */
 349 extern int mnt_lock_use_simplelock(struct libmnt_lock *ml, int enable);
 350
 351 /* optmap.c */
 352 extern const struct libmnt_optmap *mnt_optmap_get_entry(
 353                              struct libmnt_optmap const **maps,
 354                              int nmaps, const char *name,
 355                              size_t namelen,
 356                              const struct libmnt_optmap **mapent);
 357
 358 /* optstr.c */
 359 extern int mnt_optstr_remove_option_at(char **optstr, char *begin, char *end);
 360 extern int mnt_optstr_fix_gid(char **optstr, char *value, size_t valsz, char **next);
 361 extern int mnt_optstr_fix_uid(char **optstr, char *value, size_t valsz, char **next);
 362 extern int mnt_optstr_fix_secontext(char **optstr, char *value, size_t valsz, char **next);
 363 extern int mnt_optstr_fix_user(char **optstr);
 364
 365 /* fs.c */
 366 extern struct libmnt_fs *mnt_copy_mtab_fs(const struct libmnt_fs *fs);
 367 extern int __mnt_fs_set_source_ptr(struct libmnt_fs *fs, char *source);
 368 extern int __mnt_fs_set_fstype_ptr(struct libmnt_fs *fs, char *fstype);
 369
 370 /* context.c */
 371 extern int mnt_context_prepare_srcpath(struct libmnt_context *cxt);
 372 extern int mnt_context_prepare_target(struct libmnt_context *cxt);
 373 extern int mnt_context_guess_fstype(struct libmnt_context *cxt);
 374 extern int mnt_context_prepare_helper(struct libmnt_context *cxt,
 375                                       const char *name, const char *type);
 376 extern int mnt_context_prepare_update(struct libmnt_context *cxt);
 377 extern struct libmnt_fs *mnt_context_get_fs(struct libmnt_context *cxt);
 378 extern int mnt_context_merge_mflags(struct libmnt_context *cxt);
 379 extern int mnt_context_update_tabs(struct libmnt_context *cxt);
 380
 381 extern int mnt_context_umount_setopt(struct libmnt_context *cxt, int c, char *arg);
 382 extern int mnt_context_mount_setopt(struct libmnt_context *cxt, int c, char *arg);
 383
 384 extern int mnt_context_is_loopdev(struct libmnt_context *cxt);
 385 extern int mnt_context_setup_loopdev(struct libmnt_context *cxt);
 386 extern int mnt_context_delete_loopdev(struct libmnt_context *cxt);
 387 extern int mnt_context_clear_loopdev(struct libmnt_context *cxt);
 388
 389 extern int mnt_fork_context(struct libmnt_context *cxt);
 390
 391 /* tab_update.c */
 392 extern struct libmnt_fs *mnt_update_get_fs(struct libmnt_update *upd);
 393 extern int mnt_update_set_filename(struct libmnt_update *upd,
 394                                    const char *filename, int userspace_only);
 395
 396 #endif /* _LIBMOUNT_PRIVATE_H */