| /*** |
| 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_IN_SET(d, "true" |
| "/bin/true", |
| "/usr/bin/true", |
| "/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_or_backup_file(const char *filename) { |
| const char *p; |
| |
| assert(filename); |
| |
| if (filename[0] == '.' || |
| streq(filename, "lost+found") || |
| streq(filename, "aquota.user") || |
| streq(filename, "aquota.group") || |
| endswith(filename, "~")) |
| return true; |
| |
| p = strrchr(filename, '.'); |
| if (!p) |
| return false; |
| |
| /* Please, let's not add more entries to the list below. If external projects think it's a good idea to come up |
| * with always new suffixes and that everybody else should just adjust to that, then it really should be on |
| * them. Hence, in future, let's not add any more entries. Instead, let's ask those packages to instead adopt |
| * one of the generic suffixes/prefixes for hidden files or backups, possibly augmented with an additional |
| * string. Specifically: there's now: |
| * |
| * The generic suffixes "~" and ".bak" for backup files |
| * The generic prefix "." for hidden files |
| * |
| * Thus, if a new package manager "foopkg" wants its own set of ".foopkg-new", ".foopkg-old", ".foopkg-dist" |
| * or so registered, let's refuse that and ask them to use ".foopkg.new", ".foopkg.old" or ".foopkg~" instead. |
| */ |
| |
| return STR_IN_SET(p + 1, |
| "rpmnew", |
| "rpmsave", |
| "rpmorig", |
| "dpkg-old", |
| "dpkg-new", |
| "dpkg-tmp", |
| "dpkg-dist", |
| "dpkg-bak", |
| "dpkg-backup", |
| "dpkg-remove", |
| "ucf-new", |
| "ucf-old", |
| "ucf-dist", |
| "swp", |
| "bak", |
| "old", |
| "new"); |
| } |
| |
| 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/"); |
| } |