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Diffstat (limited to 'libmount/src/optmap.c')
| -rw-r--r-- | libmount/src/optmap.c | 255 |
1 files changed, 255 insertions, 0 deletions
diff --git a/libmount/src/optmap.c b/libmount/src/optmap.c new file mode 100644 index 0000000..6136e27 --- /dev/null +++ b/libmount/src/optmap.c @@ -0,0 +1,255 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ +/* + * This file is part of libmount from util-linux project. + * + * Copyright (C) 2010-2018 Karel Zak <kzak@redhat.com> + * + * libmount is free software; you can redistribute it and/or modify it + * under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation; either version 2.1 of the License, or + * (at your option) any later version. + */ + +/** + * SECTION: optmap + * @title: Option maps + * @short_description: description for mount options + * + * The mount(2) linux syscall uses two arguments for mount options: + * + * @mountflags: (see MS_* macros in linux/fs.h) + * + * @mountdata: (usually a comma separated string of options) + * + * The libmount uses options-map(s) to describe mount options. + * + * The option description (map entry) includes: + * + * @name: and argument name + * + * @id: (in the map unique identifier or a mountflags, e.g MS_RDONLY) + * + * @mask: (MNT_INVERT, MNT_NOMTAB) + * + * The option argument value is defined by: + * + * "=" -- required argument, e.g "comment=" + * + * "[=]" -- optional argument, e.g. "loop[=]" + * + * Example: + * + * <informalexample> + * <programlisting> + * #define MY_MS_FOO (1 << 1) + * #define MY_MS_BAR (1 << 2) + * + * libmnt_optmap myoptions[] = { + * { "foo", MY_MS_FOO }, + * { "nofoo", MY_MS_FOO | MNT_INVERT }, + * { "bar=", MY_MS_BAR }, + * { NULL } + * }; + * </programlisting> + * </informalexample> + * + * The libmount defines two basic built-in options maps: + * + * @MNT_LINUX_MAP: fs-independent kernel mount options (usually MS_* flags) + * + * @MNT_USERSPACE_MAP: userspace specific mount options (e.g. "user", "loop") + * + * For more details about option map struct see "struct mnt_optmap" in + * mount/mount.h. + */ +#include "mountP.h" +#include "strutils.h" + +/* + * fs-independent mount flags (built-in MNT_LINUX_MAP) + */ +static const struct libmnt_optmap linux_flags_map[] = +{ + { "ro", MS_RDONLY }, /* read-only */ + { "rw", MS_RDONLY, MNT_INVERT }, /* read-write */ + { "exec", MS_NOEXEC, MNT_INVERT }, /* permit execution of binaries */ + { "noexec", MS_NOEXEC }, /* don't execute binaries */ + { "suid", MS_NOSUID, MNT_INVERT }, /* honor suid executables */ + { "nosuid", MS_NOSUID }, /* don't honor suid executables */ + { "dev", MS_NODEV, MNT_INVERT }, /* interpret device files */ + { "nodev", MS_NODEV }, /* don't interpret devices */ + + { "sync", MS_SYNCHRONOUS }, /* synchronous I/O */ + { "async", MS_SYNCHRONOUS, MNT_INVERT },/* asynchronous I/O */ + + { "dirsync", MS_DIRSYNC }, /* synchronous directory modifications */ + { "remount", MS_REMOUNT, MNT_NOMTAB }, /* alter flags of mounted FS */ + { "bind", MS_BIND }, /* Remount part of the tree elsewhere */ + { "rbind", MS_BIND | MS_REC }, /* Idem, plus mounted subtrees */ +#ifdef MS_NOSUB + { "sub", MS_NOSUB, MNT_INVERT }, /* allow submounts */ + { "nosub", MS_NOSUB }, /* don't allow submounts */ +#endif +#ifdef MS_SILENT + { "silent", MS_SILENT }, /* be quiet */ + { "loud", MS_SILENT, MNT_INVERT }, /* print out messages. */ +#endif +#ifdef MS_MANDLOCK + { "mand", MS_MANDLOCK }, /* Allow mandatory locks on this FS */ + { "nomand", MS_MANDLOCK, MNT_INVERT }, /* Forbid mandatory locks on this FS */ +#endif +#ifdef MS_NOATIME + { "atime", MS_NOATIME, MNT_INVERT }, /* Update access time */ + { "noatime", MS_NOATIME }, /* Do not update access time */ +#endif +#ifdef MS_I_VERSION + { "iversion", MS_I_VERSION }, /* Update inode I_version time */ + { "noiversion", MS_I_VERSION, MNT_INVERT},/* Don't update inode I_version time */ +#endif +#ifdef MS_NODIRATIME + { "diratime", MS_NODIRATIME, MNT_INVERT }, /* Update dir access times */ + { "nodiratime", MS_NODIRATIME }, /* Do not update dir access times */ +#endif +#ifdef MS_RELATIME + { "relatime", MS_RELATIME }, /* Update access times relative to mtime/ctime */ + { "norelatime", MS_RELATIME, MNT_INVERT }, /* Update access time without regard to mtime/ctime */ +#endif +#ifdef MS_STRICTATIME + { "strictatime", MS_STRICTATIME }, /* Strict atime semantics */ + { "nostrictatime", MS_STRICTATIME, MNT_INVERT }, /* kernel default atime */ +#endif +#ifdef MS_LAZYTIME + { "lazytime", MS_LAZYTIME }, /* Update {a,m,c}time on the in-memory inode only */ + { "nolazytime", MS_LAZYTIME, MNT_INVERT }, +#endif +#ifdef MS_PROPAGATION + { "unbindable", MS_UNBINDABLE, MNT_NOHLPS | MNT_NOMTAB }, /* Unbindable */ + { "runbindable", MS_UNBINDABLE | MS_REC, MNT_NOHLPS | MNT_NOMTAB }, + { "private", MS_PRIVATE, MNT_NOHLPS | MNT_NOMTAB }, /* Private */ + { "rprivate", MS_PRIVATE | MS_REC, MNT_NOHLPS | MNT_NOMTAB }, + { "slave", MS_SLAVE, MNT_NOHLPS | MNT_NOMTAB }, /* Slave */ + { "rslave", MS_SLAVE | MS_REC, MNT_NOHLPS | MNT_NOMTAB }, + { "shared", MS_SHARED, MNT_NOHLPS | MNT_NOMTAB }, /* Shared */ + { "rshared", MS_SHARED | MS_REC, MNT_NOHLPS | MNT_NOMTAB }, +#endif + { NULL, 0, 0 } +}; + +/* + * userspace mount option (built-in MNT_USERSPACE_MAP) + */ +static const struct libmnt_optmap userspace_opts_map[] = +{ + { "defaults", 0, 0 }, /* default options */ + + { "auto", MNT_MS_NOAUTO, MNT_NOHLPS | MNT_INVERT | MNT_NOMTAB }, /* Can be mounted using -a */ + { "noauto", MNT_MS_NOAUTO, MNT_NOHLPS | MNT_NOMTAB }, /* Can only be mounted explicitly */ + + { "user[=]", MNT_MS_USER }, /* Allow ordinary user to mount (mtab) */ + { "nouser", MNT_MS_USER, MNT_INVERT | MNT_NOMTAB }, /* Forbid ordinary user to mount */ + + { "users", MNT_MS_USERS, MNT_NOMTAB }, /* Allow ordinary users to mount */ + { "nousers", MNT_MS_USERS, MNT_INVERT | MNT_NOMTAB }, /* Forbid ordinary users to mount */ + + { "owner", MNT_MS_OWNER, MNT_NOMTAB }, /* Let the owner of the device mount */ + { "noowner", MNT_MS_OWNER, MNT_INVERT | MNT_NOMTAB }, /* Device owner has no special privs */ + + { "group", MNT_MS_GROUP, MNT_NOMTAB }, /* Let the group of the device mount */ + { "nogroup", MNT_MS_GROUP, MNT_INVERT | MNT_NOMTAB }, /* Device group has no special privs */ + + /* + * Note that traditional init scripts assume the _netdev option in /etc/mtab to + * umount network block devices on shutdown. + */ + { "_netdev", MNT_MS_NETDEV }, /* Device requires network */ + + { "comment=", MNT_MS_COMMENT, MNT_NOHLPS | MNT_NOMTAB },/* fstab comment only */ + + { "x-", MNT_MS_XCOMMENT, MNT_NOHLPS | MNT_PREFIX }, /* persistent comments (utab) */ + { "X-", MNT_MS_XFSTABCOMM, MNT_NOHLPS | MNT_NOMTAB | MNT_PREFIX }, /* fstab only comments */ + + { "loop[=]", MNT_MS_LOOP, MNT_NOHLPS }, /* use the loop device */ + { "offset=", MNT_MS_OFFSET, MNT_NOHLPS | MNT_NOMTAB }, /* loop device offset */ + { "sizelimit=", MNT_MS_SIZELIMIT, MNT_NOHLPS | MNT_NOMTAB }, /* loop device size limit */ + { "encryption=", MNT_MS_ENCRYPTION, MNT_NOHLPS | MNT_NOMTAB }, /* loop device encryption */ + + { "nofail", MNT_MS_NOFAIL, MNT_NOMTAB }, /* Do not fail if ENOENT on dev */ + + { "uhelper=", MNT_MS_UHELPER }, /* /sbin/umount.<helper> */ + + { "helper=", MNT_MS_HELPER }, /* /sbin/mount.<helper> */ + + { NULL, 0, 0 } +}; + +/** + * mnt_get_builtin_map: + * @id: map id -- MNT_LINUX_MAP or MNT_USERSPACE_MAP + * + * MNT_LINUX_MAP - Linux kernel fs-independent mount options + * (usually MS_* flags, see linux/fs.h) + * + * MNT_USERSPACE_MAP - userspace mount(8) specific mount options + * (e.g user=, _netdev, ...) + * + * Returns: static built-in libmount map. + */ +const struct libmnt_optmap *mnt_get_builtin_optmap(int id) +{ + assert(id); + + if (id == MNT_LINUX_MAP) + return linux_flags_map; + else if (id == MNT_USERSPACE_MAP) + return userspace_opts_map; + return NULL; +} + +/* + * Looks up the @name in @maps and returns a map and in @mapent + * returns the map entry + */ +const struct libmnt_optmap *mnt_optmap_get_entry( + struct libmnt_optmap const **maps, + int nmaps, + const char *name, + size_t namelen, + const struct libmnt_optmap **mapent) +{ + int i; + + assert(maps); + assert(nmaps); + assert(name); + assert(namelen); + + if (mapent) + *mapent = NULL; + + for (i = 0; i < nmaps; i++) { + const struct libmnt_optmap *map = maps[i]; + const struct libmnt_optmap *ent; + const char *p; + + for (ent = map; ent && ent->name; ent++) { + if (ent->mask & MNT_PREFIX) { + if (startswith(name, ent->name)) { + if (mapent) + *mapent = ent; + return map; + } + continue; + } + if (strncmp(ent->name, name, namelen)) + continue; + p = ent->name + namelen; + if (*p == '\0' || *p == '=' || *p == '[') { + if (mapent) + *mapent = ent; + return map; + } + } + } + return NULL; +} + |