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-rw-r--r--src/libbasic/path-util.c797
1 files changed, 797 insertions, 0 deletions
diff --git a/src/libbasic/path-util.c b/src/libbasic/path-util.c
new file mode 100644
index 0000000000..822c09bfba
--- /dev/null
+++ b/src/libbasic/path-util.c
@@ -0,0 +1,797 @@
+/***
+ This file is part of systemd.
+
+ Copyright 2010-2012 Lennart Poettering
+
+ systemd 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.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+/* When we include libgen.h because we need dirname() we immediately
+ * undefine basename() since libgen.h defines it as a macro to the
+ * POSIX version which is really broken. We prefer GNU basename(). */
+#include <libgen.h>
+#undef basename
+
+#include "alloc-util.h"
+#include "extract-word.h"
+#include "fs-util.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "path-util.h"
+#include "stat-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "time-util.h"
+
+bool path_is_absolute(const char *p) {
+ return p[0] == '/';
+}
+
+bool is_path(const char *p) {
+ return !!strchr(p, '/');
+}
+
+int path_split_and_make_absolute(const char *p, char ***ret) {
+ char **l;
+ int r;
+
+ assert(p);
+ assert(ret);
+
+ l = strv_split(p, ":");
+ if (!l)
+ return -ENOMEM;
+
+ r = path_strv_make_absolute_cwd(l);
+ if (r < 0) {
+ strv_free(l);
+ return r;
+ }
+
+ *ret = l;
+ return r;
+}
+
+char *path_make_absolute(const char *p, const char *prefix) {
+ assert(p);
+
+ /* Makes every item in the list an absolute path by prepending
+ * the prefix, if specified and necessary */
+
+ if (path_is_absolute(p) || !prefix)
+ return strdup(p);
+
+ return strjoin(prefix, "/", p, NULL);
+}
+
+int path_make_absolute_cwd(const char *p, char **ret) {
+ char *c;
+
+ assert(p);
+ assert(ret);
+
+ /* Similar to path_make_absolute(), but prefixes with the
+ * current working directory. */
+
+ if (path_is_absolute(p))
+ c = strdup(p);
+ else {
+ _cleanup_free_ char *cwd = NULL;
+
+ cwd = get_current_dir_name();
+ if (!cwd)
+ return negative_errno();
+
+ c = strjoin(cwd, "/", p, NULL);
+ }
+ if (!c)
+ return -ENOMEM;
+
+ *ret = c;
+ return 0;
+}
+
+int path_make_relative(const char *from_dir, const char *to_path, char **_r) {
+ char *r, *p;
+ unsigned n_parents;
+
+ assert(from_dir);
+ assert(to_path);
+ assert(_r);
+
+ /* Strips the common part, and adds ".." elements as necessary. */
+
+ if (!path_is_absolute(from_dir))
+ return -EINVAL;
+
+ if (!path_is_absolute(to_path))
+ return -EINVAL;
+
+ /* Skip the common part. */
+ for (;;) {
+ size_t a;
+ size_t b;
+
+ from_dir += strspn(from_dir, "/");
+ to_path += strspn(to_path, "/");
+
+ if (!*from_dir) {
+ if (!*to_path)
+ /* from_dir equals to_path. */
+ r = strdup(".");
+ else
+ /* from_dir is a parent directory of to_path. */
+ r = strdup(to_path);
+
+ if (!r)
+ return -ENOMEM;
+
+ path_kill_slashes(r);
+
+ *_r = r;
+ return 0;
+ }
+
+ if (!*to_path)
+ break;
+
+ a = strcspn(from_dir, "/");
+ b = strcspn(to_path, "/");
+
+ if (a != b)
+ break;
+
+ if (memcmp(from_dir, to_path, a) != 0)
+ break;
+
+ from_dir += a;
+ to_path += b;
+ }
+
+ /* If we're here, then "from_dir" has one or more elements that need to
+ * be replaced with "..". */
+
+ /* Count the number of necessary ".." elements. */
+ for (n_parents = 0;;) {
+ from_dir += strspn(from_dir, "/");
+
+ if (!*from_dir)
+ break;
+
+ from_dir += strcspn(from_dir, "/");
+ n_parents++;
+ }
+
+ r = malloc(n_parents * 3 + strlen(to_path) + 1);
+ if (!r)
+ return -ENOMEM;
+
+ for (p = r; n_parents > 0; n_parents--, p += 3)
+ memcpy(p, "../", 3);
+
+ strcpy(p, to_path);
+ path_kill_slashes(r);
+
+ *_r = r;
+ return 0;
+}
+
+int path_strv_make_absolute_cwd(char **l) {
+ char **s;
+ int r;
+
+ /* Goes through every item in the string list and makes it
+ * absolute. This works in place and won't rollback any
+ * changes on failure. */
+
+ STRV_FOREACH(s, l) {
+ char *t;
+
+ r = path_make_absolute_cwd(*s, &t);
+ if (r < 0)
+ return r;
+
+ free(*s);
+ *s = t;
+ }
+
+ return 0;
+}
+
+char **path_strv_resolve(char **l, const char *prefix) {
+ char **s;
+ unsigned k = 0;
+ bool enomem = false;
+
+ if (strv_isempty(l))
+ return l;
+
+ /* Goes through every item in the string list and canonicalize
+ * the path. This works in place and won't rollback any
+ * changes on failure. */
+
+ STRV_FOREACH(s, l) {
+ char *t, *u;
+ _cleanup_free_ char *orig = NULL;
+
+ if (!path_is_absolute(*s)) {
+ free(*s);
+ continue;
+ }
+
+ if (prefix) {
+ orig = *s;
+ t = strappend(prefix, orig);
+ if (!t) {
+ enomem = true;
+ continue;
+ }
+ } else
+ t = *s;
+
+ errno = 0;
+ u = canonicalize_file_name(t);
+ if (!u) {
+ if (errno == ENOENT) {
+ if (prefix) {
+ u = orig;
+ orig = NULL;
+ free(t);
+ } else
+ u = t;
+ } else {
+ free(t);
+ if (errno == ENOMEM || errno == 0)
+ enomem = true;
+
+ continue;
+ }
+ } else if (prefix) {
+ char *x;
+
+ free(t);
+ x = path_startswith(u, prefix);
+ if (x) {
+ /* restore the slash if it was lost */
+ if (!startswith(x, "/"))
+ *(--x) = '/';
+
+ t = strdup(x);
+ free(u);
+ if (!t) {
+ enomem = true;
+ continue;
+ }
+ u = t;
+ } else {
+ /* canonicalized path goes outside of
+ * prefix, keep the original path instead */
+ free(u);
+ u = orig;
+ orig = NULL;
+ }
+ } else
+ free(t);
+
+ l[k++] = u;
+ }
+
+ l[k] = NULL;
+
+ if (enomem)
+ return NULL;
+
+ return l;
+}
+
+char **path_strv_resolve_uniq(char **l, const char *prefix) {
+
+ if (strv_isempty(l))
+ return l;
+
+ if (!path_strv_resolve(l, prefix))
+ return NULL;
+
+ return strv_uniq(l);
+}
+
+char *path_kill_slashes(char *path) {
+ char *f, *t;
+ bool slash = false;
+
+ /* Removes redundant inner and trailing slashes. Modifies the
+ * passed string in-place.
+ *
+ * ///foo///bar/ becomes /foo/bar
+ */
+
+ for (f = path, t = path; *f; f++) {
+
+ if (*f == '/') {
+ slash = true;
+ continue;
+ }
+
+ if (slash) {
+ slash = false;
+ *(t++) = '/';
+ }
+
+ *(t++) = *f;
+ }
+
+ /* Special rule, if we are talking of the root directory, a
+ trailing slash is good */
+
+ if (t == path && slash)
+ *(t++) = '/';
+
+ *t = 0;
+ return path;
+}
+
+char* path_startswith(const char *path, const char *prefix) {
+ assert(path);
+ assert(prefix);
+
+ if ((path[0] == '/') != (prefix[0] == '/'))
+ return NULL;
+
+ for (;;) {
+ size_t a, b;
+
+ path += strspn(path, "/");
+ prefix += strspn(prefix, "/");
+
+ if (*prefix == 0)
+ return (char*) path;
+
+ if (*path == 0)
+ return NULL;
+
+ a = strcspn(path, "/");
+ b = strcspn(prefix, "/");
+
+ if (a != b)
+ return NULL;
+
+ if (memcmp(path, prefix, a) != 0)
+ return NULL;
+
+ path += a;
+ prefix += b;
+ }
+}
+
+int path_compare(const char *a, const char *b) {
+ int d;
+
+ assert(a);
+ assert(b);
+
+ /* A relative path and an abolute path must not compare as equal.
+ * Which one is sorted before the other does not really matter.
+ * Here a relative path is ordered before an absolute path. */
+ d = (a[0] == '/') - (b[0] == '/');
+ if (d != 0)
+ return d;
+
+ for (;;) {
+ size_t j, k;
+
+ a += strspn(a, "/");
+ b += strspn(b, "/");
+
+ if (*a == 0 && *b == 0)
+ return 0;
+
+ /* Order prefixes first: "/foo" before "/foo/bar" */
+ if (*a == 0)
+ return -1;
+ if (*b == 0)
+ return 1;
+
+ j = strcspn(a, "/");
+ k = strcspn(b, "/");
+
+ /* Alphabetical sort: "/foo/aaa" before "/foo/b" */
+ d = memcmp(a, b, MIN(j, k));
+ if (d != 0)
+ return (d > 0) - (d < 0); /* sign of d */
+
+ /* Sort "/foo/a" before "/foo/aaa" */
+ d = (j > k) - (j < k); /* sign of (j - k) */
+ if (d != 0)
+ return d;
+
+ a += j;
+ b += k;
+ }
+}
+
+bool path_equal(const char *a, const char *b) {
+ return path_compare(a, b) == 0;
+}
+
+bool path_equal_or_files_same(const char *a, const char *b) {
+ return path_equal(a, b) || files_same(a, b) > 0;
+}
+
+char* path_join(const char *root, const char *path, const char *rest) {
+ assert(path);
+
+ if (!isempty(root))
+ return strjoin(root, endswith(root, "/") ? "" : "/",
+ path[0] == '/' ? path+1 : path,
+ rest ? (endswith(path, "/") ? "" : "/") : NULL,
+ rest && rest[0] == '/' ? rest+1 : rest,
+ NULL);
+ else
+ return strjoin(path,
+ rest ? (endswith(path, "/") ? "" : "/") : NULL,
+ rest && rest[0] == '/' ? rest+1 : rest,
+ NULL);
+}
+
+int find_binary(const char *name, char **ret) {
+ int last_error, r;
+ const char *p;
+
+ assert(name);
+
+ if (is_path(name)) {
+ if (access(name, X_OK) < 0)
+ return -errno;
+
+ if (ret) {
+ r = path_make_absolute_cwd(name, ret);
+ if (r < 0)
+ return r;
+ }
+
+ return 0;
+ }
+
+ /**
+ * Plain getenv, not secure_getenv, because we want
+ * to actually allow the user to pick the binary.
+ */
+ p = getenv("PATH");
+ if (!p)
+ p = DEFAULT_PATH;
+
+ last_error = -ENOENT;
+
+ for (;;) {
+ _cleanup_free_ char *j = NULL, *element = NULL;
+
+ r = extract_first_word(&p, &element, ":", EXTRACT_RELAX|EXTRACT_DONT_COALESCE_SEPARATORS);
+ if (r < 0)
+ return r;
+ if (r == 0)
+ break;
+
+ if (!path_is_absolute(element))
+ continue;
+
+ j = strjoin(element, "/", name, NULL);
+ if (!j)
+ return -ENOMEM;
+
+ if (access(j, X_OK) >= 0) {
+ /* Found it! */
+
+ if (ret) {
+ *ret = path_kill_slashes(j);
+ j = NULL;
+ }
+
+ return 0;
+ }
+
+ last_error = -errno;
+ }
+
+ return last_error;
+}
+
+bool paths_check_timestamp(const char* const* paths, usec_t *timestamp, bool update) {
+ bool changed = false;
+ const char* const* i;
+
+ assert(timestamp);
+
+ if (paths == NULL)
+ return false;
+
+ STRV_FOREACH(i, paths) {
+ struct stat stats;
+ usec_t u;
+
+ if (stat(*i, &stats) < 0)
+ continue;
+
+ u = timespec_load(&stats.st_mtim);
+
+ /* first check */
+ if (*timestamp >= u)
+ continue;
+
+ log_debug("timestamp of '%s' changed", *i);
+
+ /* update timestamp */
+ if (update) {
+ *timestamp = u;
+ changed = true;
+ } else
+ return true;
+ }
+
+ return changed;
+}
+
+static int binary_is_good(const char *binary) {
+ _cleanup_free_ char *p = NULL, *d = NULL;
+ int r;
+
+ r = find_binary(binary, &p);
+ if (r == -ENOENT)
+ return 0;
+ if (r < 0)
+ return r;
+
+ /* An fsck that is linked to /bin/true is a non-existent
+ * fsck */
+
+ r = readlink_malloc(p, &d);
+ if (r == -EINVAL) /* not a symlink */
+ return 1;
+ if (r < 0)
+ return r;
+
+ return !path_equal(d, "true") &&
+ !path_equal(d, "/bin/true") &&
+ !path_equal(d, "/usr/bin/true") &&
+ !path_equal(d, "/dev/null");
+}
+
+int fsck_exists(const char *fstype) {
+ const char *checker;
+
+ assert(fstype);
+
+ if (streq(fstype, "auto"))
+ return -EINVAL;
+
+ checker = strjoina("fsck.", fstype);
+ return binary_is_good(checker);
+}
+
+int mkfs_exists(const char *fstype) {
+ const char *mkfs;
+
+ assert(fstype);
+
+ if (streq(fstype, "auto"))
+ return -EINVAL;
+
+ mkfs = strjoina("mkfs.", fstype);
+ return binary_is_good(mkfs);
+}
+
+char *prefix_root(const char *root, const char *path) {
+ char *n, *p;
+ size_t l;
+
+ /* If root is passed, prefixes path with it. Otherwise returns
+ * it as is. */
+
+ assert(path);
+
+ /* First, drop duplicate prefixing slashes from the path */
+ while (path[0] == '/' && path[1] == '/')
+ path++;
+
+ if (isempty(root) || path_equal(root, "/"))
+ return strdup(path);
+
+ l = strlen(root) + 1 + strlen(path) + 1;
+
+ n = new(char, l);
+ if (!n)
+ return NULL;
+
+ p = stpcpy(n, root);
+
+ while (p > n && p[-1] == '/')
+ p--;
+
+ if (path[0] != '/')
+ *(p++) = '/';
+
+ strcpy(p, path);
+ return n;
+}
+
+int parse_path_argument_and_warn(const char *path, bool suppress_root, char **arg) {
+ char *p;
+ int r;
+
+ /*
+ * This function is intended to be used in command line
+ * parsers, to handle paths that are passed in. It makes the
+ * path absolute, and reduces it to NULL if omitted or
+ * root (the latter optionally).
+ *
+ * NOTE THAT THIS WILL FREE THE PREVIOUS ARGUMENT POINTER ON
+ * SUCCESS! Hence, do not pass in uninitialized pointers.
+ */
+
+ if (isempty(path)) {
+ *arg = mfree(*arg);
+ return 0;
+ }
+
+ r = path_make_absolute_cwd(path, &p);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse path \"%s\" and make it absolute: %m", path);
+
+ path_kill_slashes(p);
+ if (suppress_root && path_equal(p, "/"))
+ p = mfree(p);
+
+ free(*arg);
+ *arg = p;
+ return 0;
+}
+
+char* dirname_malloc(const char *path) {
+ char *d, *dir, *dir2;
+
+ assert(path);
+
+ d = strdup(path);
+ if (!d)
+ return NULL;
+
+ dir = dirname(d);
+ assert(dir);
+
+ if (dir == d)
+ return d;
+
+ dir2 = strdup(dir);
+ free(d);
+
+ return dir2;
+}
+
+bool filename_is_valid(const char *p) {
+ const char *e;
+
+ if (isempty(p))
+ return false;
+
+ if (streq(p, "."))
+ return false;
+
+ if (streq(p, ".."))
+ return false;
+
+ e = strchrnul(p, '/');
+ if (*e != 0)
+ return false;
+
+ if (e - p > FILENAME_MAX)
+ return false;
+
+ return true;
+}
+
+bool path_is_safe(const char *p) {
+
+ if (isempty(p))
+ return false;
+
+ if (streq(p, "..") || startswith(p, "../") || endswith(p, "/..") || strstr(p, "/../"))
+ return false;
+
+ if (strlen(p)+1 > PATH_MAX)
+ return false;
+
+ /* The following two checks are not really dangerous, but hey, they still are confusing */
+ if (streq(p, ".") || startswith(p, "./") || endswith(p, "/.") || strstr(p, "/./"))
+ return false;
+
+ if (strstr(p, "//"))
+ return false;
+
+ return true;
+}
+
+char *file_in_same_dir(const char *path, const char *filename) {
+ char *e, *ret;
+ size_t k;
+
+ assert(path);
+ assert(filename);
+
+ /* This removes the last component of path and appends
+ * filename, unless the latter is absolute anyway or the
+ * former isn't */
+
+ if (path_is_absolute(filename))
+ return strdup(filename);
+
+ e = strrchr(path, '/');
+ if (!e)
+ return strdup(filename);
+
+ k = strlen(filename);
+ ret = new(char, (e + 1 - path) + k + 1);
+ if (!ret)
+ return NULL;
+
+ memcpy(mempcpy(ret, path, e + 1 - path), filename, k + 1);
+ return ret;
+}
+
+bool hidden_file_allow_backup(const char *filename) {
+ assert(filename);
+
+ return
+ filename[0] == '.' ||
+ streq(filename, "lost+found") ||
+ streq(filename, "aquota.user") ||
+ streq(filename, "aquota.group") ||
+ endswith(filename, ".rpmnew") ||
+ endswith(filename, ".rpmsave") ||
+ endswith(filename, ".rpmorig") ||
+ endswith(filename, ".dpkg-old") ||
+ endswith(filename, ".dpkg-new") ||
+ endswith(filename, ".dpkg-tmp") ||
+ endswith(filename, ".dpkg-dist") ||
+ endswith(filename, ".dpkg-bak") ||
+ endswith(filename, ".dpkg-backup") ||
+ endswith(filename, ".dpkg-remove") ||
+ endswith(filename, ".swp");
+}
+
+bool hidden_file(const char *filename) {
+ assert(filename);
+
+ if (endswith(filename, "~"))
+ return true;
+
+ return hidden_file_allow_backup(filename);
+}
+
+bool is_device_path(const char *path) {
+
+ /* Returns true on paths that refer to a device, either in
+ * sysfs or in /dev */
+
+ return
+ path_startswith(path, "/dev/") ||
+ path_startswith(path, "/sys/");
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-01 03:40:20 +0000