summaryrefslogtreecommitdiffstats
path: root/libmount/src/optstr.c
diff options
context:
space:
mode:
Diffstat (limited to 'libmount/src/optstr.c')
-rw-r--r--libmount/src/optstr.c1482
1 files changed, 1482 insertions, 0 deletions
diff --git a/libmount/src/optstr.c b/libmount/src/optstr.c
new file mode 100644
index 0000000..5acc94e
--- /dev/null
+++ b/libmount/src/optstr.c
@@ -0,0 +1,1482 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * This file is part of libmount from util-linux project.
+ *
+ * Copyright (C) 2009-2018 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: optstr
+ * @title: Options string
+ * @short_description: low-level API for working with mount options
+ *
+ * This is a simple and low-level API to working with mount options that are stored
+ * in a string.
+ */
+#include <ctype.h>
+
+#ifdef HAVE_LIBSELINUX
+#include <selinux/selinux.h>
+#include <selinux/context.h>
+#endif
+
+#include "strutils.h"
+#include "mountP.h"
+#include "buffer.h"
+
+/*
+ * Option location
+ */
+struct libmnt_optloc {
+ char *begin;
+ char *end;
+ char *value;
+ size_t valsz;
+ size_t namesz;
+};
+
+#define MNT_INIT_OPTLOC { .begin = NULL }
+
+#define mnt_optmap_entry_novalue(e) \
+ (e && (e)->name && !strchr((e)->name, '=') && !((e)->mask & MNT_PREFIX))
+
+/*
+ * Parses the first option from @optstr. The @optstr pointer is set to the beginning
+ * of the next option.
+ *
+ * Returns -EINVAL on parse error, 1 at the end of optstr and 0 on success.
+ */
+static int mnt_optstr_parse_next(char **optstr, char **name, size_t *namesz,
+ char **value, size_t *valsz)
+{
+ int open_quote = 0;
+ char *start = NULL, *stop = NULL, *p, *sep = NULL;
+ char *optstr0;
+
+ assert(optstr);
+ assert(*optstr);
+
+ optstr0 = *optstr;
+
+ if (name)
+ *name = NULL;
+ if (namesz)
+ *namesz = 0;
+ if (value)
+ *value = NULL;
+ if (valsz)
+ *valsz = 0;
+
+ /* trim leading commas as to not invalidate option
+ * strings with multiple consecutive commas */
+ while (optstr0 && *optstr0 == ',')
+ optstr0++;
+
+ for (p = optstr0; p && *p; p++) {
+ if (!start)
+ start = p; /* beginning of the option item */
+ if (*p == '"')
+ open_quote ^= 1; /* reverse the status */
+ if (open_quote)
+ continue; /* still in quoted block */
+ if (!sep && p > start && *p == '=')
+ sep = p; /* name and value separator */
+ if (*p == ',')
+ stop = p; /* terminate the option item */
+ else if (*(p + 1) == '\0')
+ stop = p + 1; /* end of optstr */
+ if (!start || !stop)
+ continue;
+ if (stop <= start)
+ goto error;
+
+ if (name)
+ *name = start;
+ if (namesz)
+ *namesz = sep ? sep - start : stop - start;
+ *optstr = *stop ? stop + 1 : stop;
+
+ if (sep) {
+ if (value)
+ *value = sep + 1;
+ if (valsz)
+ *valsz = stop - sep - 1;
+ }
+ return 0;
+ }
+
+ return 1; /* end of optstr */
+
+error:
+ DBG(OPTIONS, ul_debug("parse error: \"%s\"", optstr0));
+ return -EINVAL;
+}
+
+/*
+ * Locates the first option that matches @name. The @end is set to the
+ * char behind the option (it means ',' or \0).
+ *
+ * Returns negative number on parse error, 1 when not found and 0 on success.
+ */
+static int mnt_optstr_locate_option(char *optstr, const char *name,
+ struct libmnt_optloc *ol)
+{
+ char *n;
+ size_t namesz, nsz;
+ int rc;
+
+ if (!optstr)
+ return 1;
+
+ assert(name);
+
+ namesz = strlen(name);
+
+ do {
+ rc = mnt_optstr_parse_next(&optstr, &n, &nsz,
+ &ol->value, &ol->valsz);
+ if (rc)
+ break;
+
+ if (namesz == nsz && strncmp(n, name, nsz) == 0) {
+ ol->begin = n;
+ ol->end = *(optstr - 1) == ',' ? optstr - 1 : optstr;
+ ol->namesz = nsz;
+ return 0;
+ }
+ } while(1);
+
+ return rc;
+}
+
+/**
+ * mnt_optstr_next_option:
+ * @optstr: option string, returns the position of the next option
+ * @name: returns the option name
+ * @namesz: returns the option name length
+ * @value: returns the option value or NULL
+ * @valuesz: returns the option value length or zero
+ *
+ * Parses the first option in @optstr.
+ *
+ * Returns: 0 on success, 1 at the end of @optstr or negative number in case of
+ * error.
+ */
+int mnt_optstr_next_option(char **optstr, char **name, size_t *namesz,
+ char **value, size_t *valuesz)
+{
+ if (!optstr || !*optstr)
+ return -EINVAL;
+ return mnt_optstr_parse_next(optstr, name, namesz, value, valuesz);
+}
+
+static int __buffer_append_option(struct ul_buffer *buf,
+ const char *name, size_t namesz,
+ const char *val, size_t valsz)
+{
+ int rc = 0;
+
+ if (!ul_buffer_is_empty(buf))
+ rc = ul_buffer_append_data(buf, ",", 1);
+ if (!rc)
+ rc = ul_buffer_append_data(buf, name, namesz);
+ if (val && !rc) {
+ /* we need to append '=' is value is empty string, see
+ * 727c689908c5e68c92aa1dd65e0d3bdb6d91c1e5 */
+ rc = ul_buffer_append_data(buf, "=", 1);
+ if (!rc && valsz)
+ rc = ul_buffer_append_data(buf, val, valsz);
+ }
+ return rc;
+}
+
+/**
+ * mnt_optstr_append_option:
+ * @optstr: option string or NULL, returns a reallocated string
+ * @name: value name
+ * @value: value
+ *
+ * Returns: 0 on success or <0 in case of error. After an error the @optstr should
+ * be unmodified.
+ */
+int mnt_optstr_append_option(char **optstr, const char *name, const char *value)
+{
+ struct ul_buffer buf = UL_INIT_BUFFER;
+ int rc;
+ size_t nsz, vsz, osz;
+
+ if (!optstr)
+ return -EINVAL;
+ if (!name || !*name)
+ return 0;
+
+ nsz = strlen(name);
+ osz = *optstr ? strlen(*optstr) : 0;
+ vsz = value ? strlen(value) : 0;
+
+ ul_buffer_refer_string(&buf, *optstr);
+ ul_buffer_set_chunksize(&buf, osz + nsz + vsz + 3); /* to call realloc() only once */
+
+ rc = __buffer_append_option(&buf, name, nsz, value, vsz);
+
+ *optstr = ul_buffer_get_data(&buf, NULL, NULL);
+ return rc;
+}
+/**
+ * mnt_optstr_prepend_option:
+ * @optstr: option string or NULL, returns a reallocated string
+ * @name: value name
+ * @value: value
+ *
+ * Returns: 0 on success or <0 in case of error. After an error the @optstr should
+ * be unmodified.
+ */
+int mnt_optstr_prepend_option(char **optstr, const char *name, const char *value)
+{
+ struct ul_buffer buf = UL_INIT_BUFFER;
+ size_t nsz, vsz, osz;
+ int rc;
+
+ if (!optstr)
+ return -EINVAL;
+ if (!name || !*name)
+ return 0;
+
+ nsz = strlen(name);
+ osz = *optstr ? strlen(*optstr) : 0;
+ vsz = value ? strlen(value) : 0;
+
+ ul_buffer_set_chunksize(&buf, osz + nsz + vsz + 3); /* to call realloc() only once */
+
+ rc = __buffer_append_option(&buf, name, nsz, value, vsz);
+ if (*optstr && !rc) {
+ rc = ul_buffer_append_data(&buf, ",", 1);
+ if (!rc)
+ rc = ul_buffer_append_data(&buf, *optstr, osz);
+ free(*optstr);
+ }
+
+ *optstr = ul_buffer_get_data(&buf, NULL, NULL);
+ return rc;
+}
+
+/**
+ * mnt_optstr_get_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option name
+ * @value: returns a pointer to the beginning of the value (e.g. name=VALUE) or NULL
+ * @valsz: returns size of the value or 0
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_get_option(const char *optstr, const char *name,
+ char **value, size_t *valsz)
+{
+ struct libmnt_optloc ol = MNT_INIT_OPTLOC;
+ int rc;
+
+ if (!optstr || !name)
+ return -EINVAL;
+
+ rc = mnt_optstr_locate_option((char *) optstr, name, &ol);
+ if (!rc) {
+ if (value)
+ *value = ol.value;
+ if (valsz)
+ *valsz = ol.valsz;
+ }
+ return rc;
+}
+
+/**
+ * mnt_optstr_deduplicate_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option name
+ *
+ * Removes all instances of @name except the last one.
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_deduplicate_option(char **optstr, const char *name)
+{
+ int rc;
+ char *begin = NULL, *end = NULL, *opt;
+
+ if (!optstr || !name)
+ return -EINVAL;
+
+ opt = *optstr;
+ do {
+ struct libmnt_optloc ol = MNT_INIT_OPTLOC;
+
+ rc = mnt_optstr_locate_option(opt, name, &ol);
+ if (!rc) {
+ if (begin) {
+ /* remove the previous instance */
+ size_t shift = strlen(*optstr);
+
+ mnt_optstr_remove_option_at(optstr, begin, end);
+
+ /* now all the offsets are not valid anymore - recount */
+ shift -= strlen(*optstr);
+ ol.begin -= shift;
+ ol.end -= shift;
+ }
+ begin = ol.begin;
+ end = ol.end;
+ opt = end && *end ? end + 1 : NULL;
+ }
+ if (opt == NULL)
+ break;
+ } while (rc == 0 && *opt);
+
+ return rc < 0 ? rc : begin ? 0 : 1;
+}
+
+/*
+ * The result never starts or ends with a comma or contains two commas
+ * (e.g. ",aaa,bbb" or "aaa,,bbb" or "aaa,")
+ */
+int mnt_optstr_remove_option_at(char **optstr, char *begin, char *end)
+{
+ size_t sz;
+
+ if (!optstr || !begin || !end)
+ return -EINVAL;
+
+ if ((begin == *optstr || *(begin - 1) == ',') && *end == ',')
+ end++;
+
+ sz = strlen(end);
+
+ memmove(begin, end, sz + 1);
+ if (!*begin && (begin > *optstr) && *(begin - 1) == ',')
+ *(begin - 1) = '\0';
+
+ return 0;
+}
+
+/* insert 'substr' or '=substr' to @str on position @pos */
+static int __attribute__((nonnull(1,2,3)))
+insert_value(char **str, char *pos, const char *substr, char **next)
+{
+ size_t subsz = strlen(substr); /* substring size */
+ size_t strsz = strlen(*str);
+ size_t possz = strlen(pos);
+ size_t posoff;
+ char *p;
+ int sep;
+
+ /* is it necessary to prepend '=' before the substring ? */
+ sep = !(pos > *str && *(pos - 1) == '=');
+
+ /* save an offset of the place where we need to add substr */
+ posoff = pos - *str;
+
+ p = realloc(*str, strsz + sep + subsz + 1);
+ if (!p)
+ return -ENOMEM;
+
+ /* zeroize the newly allocated memory -- valgrind loves us... */
+ memset(p + strsz, 0, sep + subsz + 1);
+
+ /* set pointers to the reallocated string */
+ *str = p;
+ pos = p + posoff;
+
+ if (possz)
+ /* create a room for the new substring */
+ memmove(pos + subsz + sep, pos, possz + 1);
+ if (sep)
+ *pos++ = '=';
+
+ memcpy(pos, substr, subsz);
+
+ if (next) {
+ /* set pointer to the next option */
+ *next = pos + subsz;
+ if (**next == ',')
+ (*next)++;
+ }
+ return 0;
+}
+
+/**
+ * mnt_optstr_set_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option
+ * @value: new value or NULL
+ *
+ * Set or unset the option @value.
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_set_option(char **optstr, const char *name, const char *value)
+{
+ struct libmnt_optloc ol = MNT_INIT_OPTLOC;
+ char *nameend;
+ int rc = 1;
+
+ if (!optstr || !name)
+ return -EINVAL;
+
+ if (*optstr)
+ rc = mnt_optstr_locate_option(*optstr, name, &ol);
+ if (rc < 0)
+ return rc; /* parse error */
+ if (rc == 1)
+ return mnt_optstr_append_option(optstr, name, value); /* not found */
+
+ nameend = ol.begin + ol.namesz;
+
+ if (value == NULL && ol.value && ol.valsz)
+ /* remove unwanted "=value" */
+ mnt_optstr_remove_option_at(optstr, nameend, ol.end);
+
+ else if (value && ol.value == NULL)
+ /* insert "=value" */
+ rc = insert_value(optstr, nameend, value, NULL);
+
+ else if (value && ol.value && strlen(value) == ol.valsz)
+ /* simply replace =value */
+ memcpy(ol.value, value, ol.valsz);
+
+ else if (value && ol.value) {
+ mnt_optstr_remove_option_at(optstr, nameend, ol.end);
+ rc = insert_value(optstr, nameend, value, NULL);
+ }
+ return rc;
+}
+
+/**
+ * mnt_optstr_remove_option:
+ * @optstr: string with a comma separated list of options
+ * @name: requested option name
+ *
+ * Returns: 0 on success, 1 when not found the @name or negative number in case
+ * of error.
+ */
+int mnt_optstr_remove_option(char **optstr, const char *name)
+{
+ struct libmnt_optloc ol = MNT_INIT_OPTLOC;
+ int rc;
+
+ if (!optstr || !name)
+ return -EINVAL;
+
+ rc = mnt_optstr_locate_option(*optstr, name, &ol);
+ if (rc != 0)
+ return rc;
+
+ mnt_optstr_remove_option_at(optstr, ol.begin, ol.end);
+ return 0;
+}
+
+/**
+ * mnt_split_optstr:
+ * @optstr: string with comma separated list of options
+ * @user: returns newly allocated string with userspace options
+ * @vfs: returns newly allocated string with VFS options
+ * @fs: returns newly allocated string with FS options
+ * @ignore_user: option mask for options that should be ignored
+ * @ignore_vfs: option mask for options that should be ignored
+ *
+ * For example:
+ *
+ * mnt_split_optstr(optstr, &u, NULL, NULL, MNT_NOMTAB, 0);
+ *
+ * returns all userspace options, the options that do not belong to
+ * mtab are ignored.
+ *
+ * Note that FS options are all options that are undefined in MNT_USERSPACE_MAP
+ * or MNT_LINUX_MAP.
+ *
+ * Returns: 0 on success, or a negative number in case of error.
+ */
+int mnt_split_optstr(const char *optstr, char **user, char **vfs,
+ char **fs, int ignore_user, int ignore_vfs)
+{
+ int rc = 0;
+ char *name, *val, *str = (char *) optstr;
+ size_t namesz, valsz, chunsz;
+ struct libmnt_optmap const *maps[2];
+ struct ul_buffer xvfs = UL_INIT_BUFFER,
+ xfs = UL_INIT_BUFFER,
+ xuser = UL_INIT_BUFFER;
+
+ if (!optstr)
+ return -EINVAL;
+
+ maps[0] = mnt_get_builtin_optmap(MNT_LINUX_MAP);
+ maps[1] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
+
+ chunsz = strlen(optstr) / 2;
+
+ while (!mnt_optstr_next_option(&str, &name, &namesz, &val, &valsz)) {
+ struct ul_buffer *buf = NULL;
+ const struct libmnt_optmap *ent = NULL;
+ const struct libmnt_optmap *m =
+ mnt_optmap_get_entry(maps, 2, name, namesz, &ent);
+
+ if (ent && !ent->id)
+ continue; /* ignore undefined options (comments) */
+
+ /* ignore name=<value> if options map expects <name> only */
+ if (valsz && mnt_optmap_entry_novalue(ent))
+ m = NULL;
+
+ if (ent && m && m == maps[0] && vfs) {
+ if (ignore_vfs && (ent->mask & ignore_vfs))
+ continue;
+ if (vfs)
+ buf = &xvfs;
+ } else if (ent && m && m == maps[1] && user) {
+ if (ignore_user && (ent->mask & ignore_user))
+ continue;
+ if (user)
+ buf = &xuser;
+ } else if (!m && fs) {
+ if (fs)
+ buf = &xfs;
+ }
+
+ if (buf) {
+ if (ul_buffer_is_empty(buf))
+ ul_buffer_set_chunksize(buf, chunsz);
+ rc = __buffer_append_option(buf, name, namesz, val, valsz);
+ }
+ if (rc)
+ break;
+ }
+
+ if (vfs)
+ *vfs = rc ? NULL : ul_buffer_get_data(&xvfs, NULL, NULL);
+ if (fs)
+ *fs = rc ? NULL : ul_buffer_get_data(&xfs, NULL, NULL);
+ if (user)
+ *user = rc ? NULL : ul_buffer_get_data(&xuser, NULL, NULL);
+ if (rc) {
+ ul_buffer_free_data(&xvfs);
+ ul_buffer_free_data(&xfs);
+ ul_buffer_free_data(&xuser);
+ }
+
+ return rc;
+}
+
+/**
+ * mnt_optstr_get_options
+ * @optstr: string with a comma separated list of options
+ * @subset: returns newly allocated string with options
+ * @map: options map
+ * @ignore: mask of the options that should be ignored
+ *
+ * Extracts options from @optstr that belong to the @map, for example:
+ *
+ * mnt_optstr_get_options(optstr, &p,
+ * mnt_get_builtin_optmap(MNT_LINUX_MAP),
+ * MNT_NOMTAB);
+ *
+ * the 'p' returns all VFS options, the options that do not belong to mtab
+ * are ignored.
+ *
+ * Returns: 0 on success, or a negative number in case of error.
+ */
+int mnt_optstr_get_options(const char *optstr, char **subset,
+ const struct libmnt_optmap *map, int ignore)
+{
+ struct libmnt_optmap const *maps[1];
+ struct ul_buffer buf = UL_INIT_BUFFER;
+ char *name, *val, *str = (char *) optstr;
+ size_t namesz, valsz;
+ int rc = 0;
+
+ if (!optstr || !subset)
+ return -EINVAL;
+
+ maps[0] = map;
+
+ ul_buffer_set_chunksize(&buf, strlen(optstr)/2);
+
+ while (!mnt_optstr_next_option(&str, &name, &namesz, &val, &valsz)) {
+ const struct libmnt_optmap *ent;
+
+ mnt_optmap_get_entry(maps, 1, name, namesz, &ent);
+
+ if (!ent || !ent->id)
+ continue; /* ignore undefined options (comments) */
+
+ if (ignore && (ent->mask & ignore))
+ continue;
+
+ /* ignore name=<value> if options map expects <name> only */
+ if (valsz && mnt_optmap_entry_novalue(ent))
+ continue;
+
+ rc = __buffer_append_option(&buf, name, namesz, val, valsz);
+ if (rc)
+ break;
+ }
+
+ *subset = rc ? NULL : ul_buffer_get_data(&buf, NULL, NULL);
+ if (rc)
+ ul_buffer_free_data(&buf);
+ return rc;
+}
+
+
+/**
+ * mnt_optstr_get_flags:
+ * @optstr: string with comma separated list of options
+ * @flags: returns mount flags
+ * @map: options map
+ *
+ * Returns in @flags IDs of options from @optstr as defined in the @map.
+ *
+ * For example:
+ *
+ * "bind,exec,foo,bar" --returns-> MS_BIND
+ *
+ * "bind,noexec,foo,bar" --returns-> MS_BIND|MS_NOEXEC
+ *
+ * Note that @flags are not zeroized by this function! This function sets/unsets
+ * bits in the @flags only.
+ *
+ * Returns: 0 on success or negative number in case of error
+ */
+int mnt_optstr_get_flags(const char *optstr, unsigned long *flags,
+ const struct libmnt_optmap *map)
+{
+ struct libmnt_optmap const *maps[2];
+ char *name, *str = (char *) optstr;
+ size_t namesz = 0, valsz = 0;
+ int nmaps = 0;
+
+ if (!optstr || !flags || !map)
+ return -EINVAL;
+
+ maps[nmaps++] = map;
+
+ if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP))
+ /*
+ * Add userspace map -- the "user" is interpreted as
+ * MS_NO{EXEC,SUID,DEV}.
+ */
+ maps[nmaps++] = mnt_get_builtin_optmap(MNT_USERSPACE_MAP);
+
+ while(!mnt_optstr_next_option(&str, &name, &namesz, NULL, &valsz)) {
+ const struct libmnt_optmap *ent;
+ const struct libmnt_optmap *m;
+
+ m = mnt_optmap_get_entry(maps, nmaps, name, namesz, &ent);
+ if (!m || !ent || !ent->id)
+ continue;
+
+ /* ignore name=<value> if options map expects <name> only */
+ if (valsz && mnt_optmap_entry_novalue(ent))
+ continue;
+
+ if (m == map) { /* requested map */
+ if (ent->mask & MNT_INVERT)
+ *flags &= ~ent->id;
+ else
+ *flags |= ent->id;
+
+ } else if (nmaps == 2 && m == maps[1] && valsz == 0) {
+ /*
+ * Special case -- translate "user" (but no user=) to
+ * MS_ options
+ */
+ if (ent->mask & MNT_INVERT)
+ continue;
+ if (ent->id & (MNT_MS_OWNER | MNT_MS_GROUP))
+ *flags |= MS_OWNERSECURE;
+ else if (ent->id & (MNT_MS_USER | MNT_MS_USERS))
+ *flags |= MS_SECURE;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * mnt_optstr_apply_flags:
+ * @optstr: string with comma separated list of options
+ * @flags: returns mount flags
+ * @map: options map
+ *
+ * Removes/adds options to the @optstr according to flags. For example:
+ *
+ * MS_NOATIME and "foo,bar,noexec" --returns-> "foo,bar,noatime"
+ *
+ * Returns: 0 on success or negative number in case of error.
+ */
+int mnt_optstr_apply_flags(char **optstr, unsigned long flags,
+ const struct libmnt_optmap *map)
+{
+ struct libmnt_optmap const *maps[1];
+ char *name, *next, *val;
+ size_t namesz = 0, valsz = 0, multi = 0;
+ unsigned long fl;
+ int rc = 0;
+
+ if (!optstr || !map)
+ return -EINVAL;
+
+ DBG(CXT, ul_debug("applying 0x%08lx flags to '%s'", flags, *optstr));
+
+ maps[0] = map;
+ next = *optstr;
+ fl = flags;
+
+ /*
+ * There is a convention that 'rw/ro' flags are always at the beginning of
+ * the string (although the 'rw' is unnecessary).
+ */
+ if (map == mnt_get_builtin_optmap(MNT_LINUX_MAP)) {
+ const char *o = (fl & MS_RDONLY) ? "ro" : "rw";
+
+ if (next &&
+ (!strncmp(next, "rw", 2) || !strncmp(next, "ro", 2)) &&
+ (*(next + 2) == '\0' || *(next + 2) == ',')) {
+
+ /* already set, be paranoid and fix it */
+ memcpy(next, o, 2);
+ } else {
+ rc = mnt_optstr_prepend_option(optstr, o, NULL);
+ if (rc)
+ goto err;
+ next = *optstr; /* because realloc() */
+ }
+ fl &= ~MS_RDONLY;
+ next += 2;
+ if (*next == ',')
+ next++;
+ }
+
+ if (next && *next) {
+ /*
+ * scan @optstr and remove options that are missing in
+ * @flags
+ */
+ while(!mnt_optstr_next_option(&next, &name, &namesz,
+ &val, &valsz)) {
+ const struct libmnt_optmap *ent;
+
+ if (mnt_optmap_get_entry(maps, 1, name, namesz, &ent)) {
+ /*
+ * remove unwanted option (rw/ro is already set)
+ */
+ if (!ent || !ent->id)
+ continue;
+ /* ignore name=<value> if options map expects <name> only */
+ if (valsz && mnt_optmap_entry_novalue(ent))
+ continue;
+
+ if (ent->id == MS_RDONLY ||
+ (ent->mask & MNT_INVERT) ||
+ (fl & ent->id) != (unsigned long) ent->id) {
+
+ char *end = val ? val + valsz :
+ name + namesz;
+ next = name;
+ rc = mnt_optstr_remove_option_at(
+ optstr, name, end);
+ if (rc)
+ goto err;
+ }
+ if (!(ent->mask & MNT_INVERT)) {
+ /* allow options with prefix (X-mount.foo,X-mount.bar) more than once */
+ if (ent->mask & MNT_PREFIX)
+ multi |= ent->id;
+ else
+ fl &= ~ent->id;
+ if (ent->id & MS_REC)
+ fl |= MS_REC;
+ }
+ }
+ }
+ }
+
+ /* remove from flags options which are allowed more than once */
+ fl &= ~multi;
+
+ /* add missing options (but ignore fl if contains MS_REC only) */
+ if (fl && fl != MS_REC) {
+
+ const struct libmnt_optmap *ent;
+ struct ul_buffer buf = UL_INIT_BUFFER;
+ size_t sz;
+ char *p;
+
+ ul_buffer_refer_string(&buf, *optstr);
+
+ for (ent = map; ent && ent->name; ent++) {
+ if ((ent->mask & MNT_INVERT)
+ || ent->id == 0
+ || (fl & ent->id) != (unsigned long) ent->id)
+ continue;
+
+ /* don't add options which require values (e.g. offset=%d) */
+ p = strchr(ent->name, '=');
+ if (p) {
+ if (p > ent->name && *(p - 1) == '[')
+ p--; /* name[=] */
+ else
+ continue; /* name= */
+ sz = p - ent->name;
+ } else
+ sz = strlen(ent->name);
+
+ rc = __buffer_append_option(&buf, ent->name, sz, NULL, 0);
+ if (rc)
+ goto err;
+ }
+
+ *optstr = ul_buffer_get_data(&buf, NULL, NULL);
+ }
+
+ DBG(CXT, ul_debug("new optstr '%s'", *optstr));
+ return rc;
+err:
+ DBG(CXT, ul_debug("failed to apply flags [rc=%d]", rc));
+ return rc;
+}
+
+/*
+ * @optstr: string with comma separated list of options
+ * @value: pointer to the begin of the context value
+ * @valsz: size of the value
+ * @next: returns pointer to the next option (optional argument)
+ *
+ * Translates SELinux context from human to raw format. The function does not
+ * modify @optstr and returns zero if libmount is compiled without SELinux
+ * support.
+ *
+ * Returns: 0 on success, a negative number in case of error.
+ */
+#ifndef HAVE_LIBSELINUX
+int mnt_optstr_fix_secontext(char **optstr __attribute__ ((__unused__)),
+ char *value __attribute__ ((__unused__)),
+ size_t valsz __attribute__ ((__unused__)),
+ char **next __attribute__ ((__unused__)))
+{
+ return 0;
+}
+#else
+int mnt_optstr_fix_secontext(char **optstr,
+ char *value,
+ size_t valsz,
+ char **next)
+{
+ int rc = 0;
+ char *p, *val, *begin, *end, *raw = NULL;
+ size_t sz;
+
+ if (!optstr || !*optstr || !value || !valsz)
+ return -EINVAL;
+
+ DBG(CXT, ul_debug("fixing SELinux context"));
+
+ begin = value;
+ end = value + valsz;
+
+ /* the selinux contexts are quoted */
+ if (*value == '"') {
+ if (valsz <= 2 || *(value + valsz - 1) != '"')
+ return -EINVAL; /* improperly quoted option string */
+ value++;
+ valsz -= 2;
+ }
+
+ p = strndup(value, valsz);
+ if (!p)
+ return -ENOMEM;
+
+
+ /* translate the context */
+ rc = selinux_trans_to_raw_context(p, &raw);
+
+ DBG(CXT, ul_debug("SELinux context '%s' translated to '%s'",
+ p, rc == -1 ? "FAILED" : (char *) raw));
+
+ free(p);
+ if (rc == -1 || !raw)
+ return -EINVAL;
+
+
+ /* create a quoted string from the raw context */
+ sz = strlen((char *) raw);
+ if (!sz) {
+ freecon(raw);
+ return -EINVAL;
+ }
+
+ p = val = malloc(valsz + 3);
+ if (!val) {
+ freecon(raw);
+ return -ENOMEM;
+ }
+
+ *p++ = '"';
+ memcpy(p, raw, sz);
+ p += sz;
+ *p++ = '"';
+ *p = '\0';
+
+ freecon(raw);
+
+ /* set new context */
+ mnt_optstr_remove_option_at(optstr, begin, end);
+ rc = insert_value(optstr, begin, val, next);
+ free(val);
+
+ return rc;
+}
+#endif
+
+static int set_uint_value(char **optstr, unsigned int num,
+ char *begin, char *end, char **next)
+{
+ char buf[40];
+ snprintf(buf, sizeof(buf), "%u", num);
+
+ mnt_optstr_remove_option_at(optstr, begin, end);
+ return insert_value(optstr, begin, buf, next);
+}
+
+/*
+ * @optstr: string with a comma separated list of options
+ * @value: pointer to the beginning of the uid value
+ * @valsz: size of the value
+ * @next: returns pointer to the next option (optional argument)
+
+ * Translates "username" or "useruid" to the real UID.
+ *
+ * For example:
+ * if (!mnt_optstr_get_option(optstr, "uid", &val, &valsz))
+ * mnt_optstr_fix_uid(&optstr, val, valsz, NULL);
+ *
+ * Returns: 0 on success, a negative number in case of error.
+ */
+int mnt_optstr_fix_uid(char **optstr, char *value, size_t valsz, char **next)
+{
+ char *end;
+
+ if (!optstr || !*optstr || !value || !valsz)
+ return -EINVAL;
+
+ DBG(CXT, ul_debug("fixing uid"));
+
+ end = value + valsz;
+
+ if (valsz == 7 && !strncmp(value, "useruid", 7) &&
+ (*(value + 7) == ',' || !*(value + 7)))
+ return set_uint_value(optstr, getuid(), value, end, next);
+
+ if (!isdigit(*value)) {
+ uid_t id;
+ int rc;
+ char *p = strndup(value, valsz);
+ if (!p)
+ return -ENOMEM;
+ rc = mnt_get_uid(p, &id);
+ free(p);
+
+ if (!rc)
+ return set_uint_value(optstr, id, value, end, next);
+ }
+
+ if (next) {
+ /* no change, let's keep the original value */
+ *next = value + valsz;
+ if (**next == ',')
+ (*next)++;
+ }
+
+ return 0;
+}
+
+/*
+ * @optstr: string with a comma separated list of options
+ * @value: pointer to the beginning of the uid value
+ * @valsz: size of the value
+ * @next: returns pointer to the next option (optional argument)
+
+ * Translates "groupname" or "usergid" to the real GID.
+ *
+ * Returns: 0 on success, a negative number in case of error.
+ */
+int mnt_optstr_fix_gid(char **optstr, char *value, size_t valsz, char **next)
+{
+ char *end;
+
+ if (!optstr || !*optstr || !value || !valsz)
+ return -EINVAL;
+
+ DBG(CXT, ul_debug("fixing gid"));
+
+ end = value + valsz;
+
+ if (valsz == 7 && !strncmp(value, "usergid", 7) &&
+ (*(value + 7) == ',' || !*(value + 7)))
+ return set_uint_value(optstr, getgid(), value, end, next);
+
+ if (!isdigit(*value)) {
+ int rc;
+ gid_t id;
+ char *p = strndup(value, valsz);
+ if (!p)
+ return -ENOMEM;
+ rc = mnt_get_gid(p, &id);
+ free(p);
+
+ if (!rc)
+ return set_uint_value(optstr, id, value, end, next);
+
+ }
+
+ if (next) {
+ /* nothing */
+ *next = value + valsz;
+ if (**next == ',')
+ (*next)++;
+ }
+ return 0;
+}
+
+/*
+ * Converts "user" to "user=<username>".
+ *
+ * Returns: 0 on success, negative number in case of error.
+ */
+int mnt_optstr_fix_user(char **optstr)
+{
+ char *username;
+ struct libmnt_optloc ol = MNT_INIT_OPTLOC;
+ int rc = 0;
+
+ DBG(CXT, ul_debug("fixing user"));
+
+ rc = mnt_optstr_locate_option(*optstr, "user", &ol);
+ if (rc)
+ return rc == 1 ? 0 : rc; /* 1: user= not found */
+
+ username = mnt_get_username(getuid());
+ if (!username)
+ return -ENOMEM;
+
+ if (!ol.valsz || (ol.value && strncmp(ol.value, username, ol.valsz) != 0)) {
+ if (ol.valsz)
+ /* remove old value */
+ mnt_optstr_remove_option_at(optstr, ol.value, ol.end);
+
+ rc = insert_value(optstr, ol.value ? ol.value : ol.end,
+ username, NULL);
+ }
+
+ free(username);
+ return rc;
+}
+
+/*
+ * Converts value from @optstr addressed by @name to uid.
+ *
+ * Returns: 0 on success, 1 if not found, <0 on error
+ */
+int mnt_optstr_get_uid(const char *optstr, const char *name, uid_t *uid)
+{
+ char *value = NULL;
+ size_t valsz = 0;
+ char buf[sizeof(stringify_value(UINT64_MAX))];
+ int rc;
+ uint64_t num;
+
+ assert(optstr);
+ assert(name);
+ assert(uid);
+
+ rc = mnt_optstr_get_option(optstr, name, &value, &valsz);
+ if (rc != 0)
+ goto fail;
+
+ if (valsz > sizeof(buf) - 1) {
+ rc = -ERANGE;
+ goto fail;
+ }
+ mem2strcpy(buf, value, valsz, sizeof(buf));
+
+ rc = ul_strtou64(buf, &num, 10);
+ if (rc != 0)
+ goto fail;
+ if (num > ULONG_MAX || (uid_t) num != num) {
+ rc = -ERANGE;
+ goto fail;
+ }
+ *uid = (uid_t) num;
+
+ return 0;
+fail:
+ DBG(UTILS, ul_debug("failed to convert '%s'= to number [rc=%d]", name, rc));
+ return rc;
+}
+
+/**
+ * mnt_match_options:
+ * @optstr: options string
+ * @pattern: comma delimited list of options
+ *
+ * The "no" could be used for individual items in the @options list. The "no"
+ * prefix does not have a global meaning.
+ *
+ * Unlike fs type matching, nonetdev,user and nonetdev,nouser have
+ * DIFFERENT meanings; each option is matched explicitly as specified.
+ *
+ * The "no" prefix interpretation could be disabled by the "+" prefix, for example
+ * "+noauto" matches if @optstr literally contains the "noauto" string.
+ *
+ * "xxx,yyy,zzz" : "nozzz" -> False
+ *
+ * "xxx,yyy,zzz" : "xxx,noeee" -> True
+ *
+ * "bar,zzz" : "nofoo" -> True (does not contain "foo")
+ *
+ * "nofoo,bar" : "nofoo" -> True (does not contain "foo")
+ *
+ * "nofoo,bar" : "+nofoo" -> True (contains "nofoo")
+ *
+ * "bar,zzz" : "+nofoo" -> False (does not contain "nofoo")
+ *
+ *
+ * Returns: 1 if pattern is matching, else 0. This function also returns 0
+ * if @pattern is NULL and @optstr is non-NULL.
+ */
+int mnt_match_options(const char *optstr, const char *pattern)
+{
+ char *name, *pat = (char *) pattern;
+ char *buf, *patval;
+ size_t namesz = 0, patvalsz = 0;
+ int match = 1;
+
+ if (!pattern && !optstr)
+ return 1;
+ if (!pattern)
+ return 0;
+
+ buf = malloc(strlen(pattern) + 1);
+ if (!buf)
+ return 0;
+
+ /* walk on pattern string
+ */
+ while (match && !mnt_optstr_next_option(&pat, &name, &namesz,
+ &patval, &patvalsz)) {
+ char *val;
+ size_t sz;
+ int no = 0, rc;
+
+ if (*name == '+')
+ name++, namesz--;
+ else if ((no = (startswith(name, "no") != NULL)))
+ name += 2, namesz -= 2;
+
+ xstrncpy(buf, name, namesz + 1);
+
+ rc = mnt_optstr_get_option(optstr, buf, &val, &sz);
+
+ /* check also value (if the pattern is "foo=value") */
+ if (rc == 0 && patvalsz > 0 &&
+ (patvalsz != sz || strncmp(patval, val, sz) != 0))
+ rc = 1;
+
+ switch (rc) {
+ case 0: /* found */
+ match = no == 0 ? 1 : 0;
+ break;
+ case 1: /* not found */
+ match = no == 1 ? 1 : 0;
+ break;
+ default: /* parse error */
+ match = 0;
+ break;
+ }
+
+ }
+
+ free(buf);
+ return match;
+}
+
+#ifdef TEST_PROGRAM
+#include "xalloc.h"
+
+static int test_append(struct libmnt_test *ts, int argc, char *argv[])
+{
+ const char *value = NULL, *name;
+ char *optstr;
+ int rc;
+
+ if (argc < 3)
+ return -EINVAL;
+ optstr = xstrdup(argv[1]);
+ name = argv[2];
+
+ if (argc == 4)
+ value = argv[3];
+
+ rc = mnt_optstr_append_option(&optstr, name, value);
+ if (!rc)
+ printf("result: >%s<\n", optstr);
+ free(optstr);
+ return rc;
+}
+
+static int test_prepend(struct libmnt_test *ts, int argc, char *argv[])
+{
+ const char *value = NULL, *name;
+ char *optstr;
+ int rc;
+
+ if (argc < 3)
+ return -EINVAL;
+ optstr = xstrdup(argv[1]);
+ name = argv[2];
+
+ if (argc == 4)
+ value = argv[3];
+
+ rc = mnt_optstr_prepend_option(&optstr, name, value);
+ if (!rc)
+ printf("result: >%s<\n", optstr);
+ free(optstr);
+ return rc;
+}
+
+static int test_split(struct libmnt_test *ts, int argc, char *argv[])
+{
+ char *optstr, *user = NULL, *fs = NULL, *vfs = NULL;
+ int rc;
+
+ if (argc < 2)
+ return -EINVAL;
+
+ optstr = xstrdup(argv[1]);
+
+ rc = mnt_split_optstr(optstr, &user, &vfs, &fs, 0, 0);
+ if (!rc) {
+ printf("user : %s\n", user);
+ printf("vfs : %s\n", vfs);
+ printf("fs : %s\n", fs);
+ }
+
+ free(user);
+ free(vfs);
+ free(fs);
+ free(optstr);
+ return rc;
+}
+
+static int test_flags(struct libmnt_test *ts, int argc, char *argv[])
+{
+ char *optstr;
+ int rc;
+ unsigned long fl = 0;
+
+ if (argc < 2)
+ return -EINVAL;
+
+ optstr = xstrdup(argv[1]);
+
+ rc = mnt_optstr_get_flags(optstr, &fl, mnt_get_builtin_optmap(MNT_LINUX_MAP));
+ if (rc)
+ return rc;
+ printf("mountflags: 0x%08lx\n", fl);
+
+ fl = 0;
+ rc = mnt_optstr_get_flags(optstr, &fl, mnt_get_builtin_optmap(MNT_USERSPACE_MAP));
+ if (rc)
+ return rc;
+ printf("userspace-mountflags: 0x%08lx\n", fl);
+
+ free(optstr);
+ return rc;
+}
+
+static int test_apply(struct libmnt_test *ts, int argc, char *argv[])
+{
+ char *optstr;
+ int rc, map;
+ unsigned long flags;
+
+ if (argc < 4)
+ return -EINVAL;
+
+ if (!strcmp(argv[1], "--user"))
+ map = MNT_USERSPACE_MAP;
+ else if (!strcmp(argv[1], "--linux"))
+ map = MNT_LINUX_MAP;
+ else {
+ fprintf(stderr, "unknown option '%s'\n", argv[1]);
+ return -EINVAL;
+ }
+
+ optstr = xstrdup(argv[2]);
+ flags = strtoul(argv[3], NULL, 16);
+
+ printf("flags: 0x%08lx\n", flags);
+
+ rc = mnt_optstr_apply_flags(&optstr, flags, mnt_get_builtin_optmap(map));
+ printf("optstr: %s\n", optstr);
+
+ free(optstr);
+ return rc;
+}
+
+static int test_set(struct libmnt_test *ts, int argc, char *argv[])
+{
+ const char *value = NULL, *name;
+ char *optstr;
+ int rc;
+
+ if (argc < 3)
+ return -EINVAL;
+ optstr = xstrdup(argv[1]);
+ name = argv[2];
+
+ if (argc == 4)
+ value = argv[3];
+
+ rc = mnt_optstr_set_option(&optstr, name, value);
+ if (!rc)
+ printf("result: >%s<\n", optstr);
+ free(optstr);
+ return rc;
+}
+
+static int test_get(struct libmnt_test *ts, int argc, char *argv[])
+{
+ char *optstr;
+ const char *name;
+ char *val = NULL;
+ size_t sz = 0;
+ int rc;
+
+ if (argc < 2)
+ return -EINVAL;
+ optstr = argv[1];
+ name = argv[2];
+
+ rc = mnt_optstr_get_option(optstr, name, &val, &sz);
+ if (rc == 0) {
+ printf("found; name: %s", name);
+ if (sz) {
+ printf(", argument: size=%zd data=", sz);
+ if (fwrite(val, 1, sz, stdout) != sz)
+ return -1;
+ }
+ printf("\n");
+ } else if (rc == 1)
+ printf("%s: not found\n", name);
+ else
+ printf("parse error: %s\n", optstr);
+ return rc;
+}
+
+static int test_remove(struct libmnt_test *ts, int argc, char *argv[])
+{
+ const char *name;
+ char *optstr;
+ int rc;
+
+ if (argc < 3)
+ return -EINVAL;
+ optstr = xstrdup(argv[1]);
+ name = argv[2];
+
+ rc = mnt_optstr_remove_option(&optstr, name);
+ if (!rc)
+ printf("result: >%s<\n", optstr);
+ free(optstr);
+ return rc;
+}
+
+static int test_dedup(struct libmnt_test *ts, int argc, char *argv[])
+{
+ const char *name;
+ char *optstr;
+ int rc;
+
+ if (argc < 3)
+ return -EINVAL;
+ optstr = xstrdup(argv[1]);
+ name = argv[2];
+
+ rc = mnt_optstr_deduplicate_option(&optstr, name);
+ if (!rc)
+ printf("result: >%s<\n", optstr);
+ free(optstr);
+ return rc;
+}
+
+static int test_fix(struct libmnt_test *ts, int argc, char *argv[])
+{
+ char *optstr;
+ int rc = 0;
+ char *name, *val, *next;
+ size_t valsz, namesz;
+
+ if (argc < 2)
+ return -EINVAL;
+
+ next = optstr = xstrdup(argv[1]);
+
+ printf("optstr: %s\n", optstr);
+
+ while (!mnt_optstr_next_option(&next, &name, &namesz, &val, &valsz)) {
+
+ if (!strncmp(name, "uid", 3))
+ rc = mnt_optstr_fix_uid(&optstr, val, valsz, &next);
+ else if (!strncmp(name, "gid", 3))
+ rc = mnt_optstr_fix_gid(&optstr, val, valsz, &next);
+ else if (!strncmp(name, "context", 7))
+ rc = mnt_optstr_fix_secontext(&optstr, val, valsz, &next);
+ if (rc)
+ break;
+ }
+ if (rc)
+ rc = mnt_optstr_fix_user(&optstr);
+
+ printf("fixed: %s\n", optstr);
+
+ free(optstr);
+ return rc;
+
+}
+
+int main(int argc, char *argv[])
+{
+ struct libmnt_test tss[] = {
+ { "--append", test_append, "<optstr> <name> [<value>] append value to optstr" },
+ { "--prepend",test_prepend,"<optstr> <name> [<value>] prepend value to optstr" },
+ { "--set", test_set, "<optstr> <name> [<value>] (un)set value" },
+ { "--get", test_get, "<optstr> <name> search name in optstr" },
+ { "--remove", test_remove, "<optstr> <name> remove name in optstr" },
+ { "--dedup", test_dedup, "<optstr> <name> deduplicate name in optstr" },
+ { "--split", test_split, "<optstr> split into FS, VFS and userspace" },
+ { "--flags", test_flags, "<optstr> convert options to MS_* flags" },
+ { "--apply", test_apply, "--{linux,user} <optstr> <mask> apply mask to optstr" },
+ { "--fix", test_fix, "<optstr> fix uid=, gid=, user, and context=" },
+
+ { NULL }
+ };
+ return mnt_run_test(tss, argc, argv);
+}
+#endif /* TEST_PROGRAM */
generated by cgit v1.2.3 (git 2.39.1) at 2024-05-17 21:13:18 +0000