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-rw-r--r--src/basic/unit-name.c796
1 files changed, 796 insertions, 0 deletions
diff --git a/src/basic/unit-name.c b/src/basic/unit-name.c
new file mode 100644
index 0000000..c1529bb
--- /dev/null
+++ b/src/basic/unit-name.c
@@ -0,0 +1,796 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "glob-util.h"
+#include "hexdecoct.h"
+#include "path-util.h"
+#include "special.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+
+/* Characters valid in a unit name. */
+#define VALID_CHARS \
+ DIGITS \
+ LETTERS \
+ ":-_.\\"
+
+/* The same, but also permits the single @ character that may appear */
+#define VALID_CHARS_WITH_AT \
+ "@" \
+ VALID_CHARS
+
+/* All chars valid in a unit name glob */
+#define VALID_CHARS_GLOB \
+ VALID_CHARS_WITH_AT \
+ "[]!-*?"
+
+bool unit_name_is_valid(const char *n, UnitNameFlags flags) {
+ const char *e, *i, *at;
+
+ assert((flags & ~(UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE)) == 0);
+
+ if (_unlikely_(flags == 0))
+ return false;
+
+ if (isempty(n))
+ return false;
+
+ if (strlen(n) >= UNIT_NAME_MAX)
+ return false;
+
+ e = strrchr(n, '.');
+ if (!e || e == n)
+ return false;
+
+ if (unit_type_from_string(e + 1) < 0)
+ return false;
+
+ for (i = n, at = NULL; i < e; i++) {
+
+ if (*i == '@' && !at)
+ at = i;
+
+ if (!strchr("@" VALID_CHARS, *i))
+ return false;
+ }
+
+ if (at == n)
+ return false;
+
+ if (flags & UNIT_NAME_PLAIN)
+ if (!at)
+ return true;
+
+ if (flags & UNIT_NAME_INSTANCE)
+ if (at && e > at + 1)
+ return true;
+
+ if (flags & UNIT_NAME_TEMPLATE)
+ if (at && e == at + 1)
+ return true;
+
+ return false;
+}
+
+bool unit_prefix_is_valid(const char *p) {
+
+ /* We don't allow additional @ in the prefix string */
+
+ if (isempty(p))
+ return false;
+
+ return in_charset(p, VALID_CHARS);
+}
+
+bool unit_instance_is_valid(const char *i) {
+
+ /* The max length depends on the length of the string, so we
+ * don't really check this here. */
+
+ if (isempty(i))
+ return false;
+
+ /* We allow additional @ in the instance string, we do not
+ * allow them in the prefix! */
+
+ return in_charset(i, "@" VALID_CHARS);
+}
+
+bool unit_suffix_is_valid(const char *s) {
+ if (isempty(s))
+ return false;
+
+ if (s[0] != '.')
+ return false;
+
+ if (unit_type_from_string(s + 1) < 0)
+ return false;
+
+ return true;
+}
+
+int unit_name_to_prefix(const char *n, char **ret) {
+ const char *p;
+ char *s;
+
+ assert(n);
+ assert(ret);
+
+ if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+ return -EINVAL;
+
+ p = strchr(n, '@');
+ if (!p)
+ p = strrchr(n, '.');
+
+ assert_se(p);
+
+ s = strndup(n, p - n);
+ if (!s)
+ return -ENOMEM;
+
+ *ret = s;
+ return 0;
+}
+
+int unit_name_to_instance(const char *n, char **ret) {
+ const char *p, *d;
+
+ assert(n);
+
+ if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+ return -EINVAL;
+
+ /* Everything past the first @ and before the last . is the instance */
+ p = strchr(n, '@');
+ if (!p) {
+ if (ret)
+ *ret = NULL;
+ return UNIT_NAME_PLAIN;
+ }
+
+ p++;
+
+ d = strrchr(p, '.');
+ if (!d)
+ return -EINVAL;
+
+ if (ret) {
+ char *i = strndup(p, d-p);
+ if (!i)
+ return -ENOMEM;
+
+ *ret = i;
+ }
+ return d > p ? UNIT_NAME_INSTANCE : UNIT_NAME_TEMPLATE;
+}
+
+int unit_name_to_prefix_and_instance(const char *n, char **ret) {
+ const char *d;
+ char *s;
+
+ assert(n);
+ assert(ret);
+
+ if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+ return -EINVAL;
+
+ d = strrchr(n, '.');
+ if (!d)
+ return -EINVAL;
+
+ s = strndup(n, d - n);
+ if (!s)
+ return -ENOMEM;
+
+ *ret = s;
+ return 0;
+}
+
+UnitType unit_name_to_type(const char *n) {
+ const char *e;
+
+ assert(n);
+
+ if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+ return _UNIT_TYPE_INVALID;
+
+ assert_se(e = strrchr(n, '.'));
+
+ return unit_type_from_string(e + 1);
+}
+
+int unit_name_change_suffix(const char *n, const char *suffix, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ size_t a, b;
+ char *e;
+
+ assert(n);
+ assert(suffix);
+ assert(ret);
+
+ if (!unit_name_is_valid(n, UNIT_NAME_ANY))
+ return -EINVAL;
+
+ if (!unit_suffix_is_valid(suffix))
+ return -EINVAL;
+
+ assert_se(e = strrchr(n, '.'));
+
+ a = e - n;
+ b = strlen(suffix);
+
+ s = new(char, a + b + 1);
+ if (!s)
+ return -ENOMEM;
+
+ strcpy(mempcpy(s, n, a), suffix);
+
+ /* Make sure the name is still valid (i.e. didn't grow too large due to longer suffix) */
+ if (!unit_name_is_valid(s, UNIT_NAME_ANY))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+int unit_name_build(const char *prefix, const char *instance, const char *suffix, char **ret) {
+ UnitType type;
+
+ assert(prefix);
+ assert(suffix);
+ assert(ret);
+
+ if (suffix[0] != '.')
+ return -EINVAL;
+
+ type = unit_type_from_string(suffix + 1);
+ if (type < 0)
+ return -EINVAL;
+
+ return unit_name_build_from_type(prefix, instance, type, ret);
+}
+
+int unit_name_build_from_type(const char *prefix, const char *instance, UnitType type, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ const char *ut;
+
+ assert(prefix);
+ assert(type >= 0);
+ assert(type < _UNIT_TYPE_MAX);
+ assert(ret);
+
+ if (!unit_prefix_is_valid(prefix))
+ return -EINVAL;
+
+ ut = unit_type_to_string(type);
+
+ if (instance) {
+ if (!unit_instance_is_valid(instance))
+ return -EINVAL;
+
+ s = strjoin(prefix, "@", instance, ".", ut);
+ } else
+ s = strjoin(prefix, ".", ut);
+ if (!s)
+ return -ENOMEM;
+
+ /* Verify that this didn't grow too large (or otherwise is invalid) */
+ if (!unit_name_is_valid(s, instance ? UNIT_NAME_INSTANCE : UNIT_NAME_PLAIN))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+static char *do_escape_char(char c, char *t) {
+ assert(t);
+
+ *(t++) = '\\';
+ *(t++) = 'x';
+ *(t++) = hexchar(c >> 4);
+ *(t++) = hexchar(c);
+
+ return t;
+}
+
+static char *do_escape(const char *f, char *t) {
+ assert(f);
+ assert(t);
+
+ /* do not create units with a leading '.', like for "/.dotdir" mount points */
+ if (*f == '.') {
+ t = do_escape_char(*f, t);
+ f++;
+ }
+
+ for (; *f; f++) {
+ if (*f == '/')
+ *(t++) = '-';
+ else if (IN_SET(*f, '-', '\\') || !strchr(VALID_CHARS, *f))
+ t = do_escape_char(*f, t);
+ else
+ *(t++) = *f;
+ }
+
+ return t;
+}
+
+char *unit_name_escape(const char *f) {
+ char *r, *t;
+
+ assert(f);
+
+ r = new(char, strlen(f)*4+1);
+ if (!r)
+ return NULL;
+
+ t = do_escape(f, r);
+ *t = 0;
+
+ return r;
+}
+
+int unit_name_unescape(const char *f, char **ret) {
+ _cleanup_free_ char *r = NULL;
+ char *t;
+
+ assert(f);
+
+ r = strdup(f);
+ if (!r)
+ return -ENOMEM;
+
+ for (t = r; *f; f++) {
+ if (*f == '-')
+ *(t++) = '/';
+ else if (*f == '\\') {
+ int a, b;
+
+ if (f[1] != 'x')
+ return -EINVAL;
+
+ a = unhexchar(f[2]);
+ if (a < 0)
+ return -EINVAL;
+
+ b = unhexchar(f[3]);
+ if (b < 0)
+ return -EINVAL;
+
+ *(t++) = (char) (((uint8_t) a << 4U) | (uint8_t) b);
+ f += 3;
+ } else
+ *(t++) = *f;
+ }
+
+ *t = 0;
+
+ *ret = TAKE_PTR(r);
+
+ return 0;
+}
+
+int unit_name_path_escape(const char *f, char **ret) {
+ char *p, *s;
+
+ assert(f);
+ assert(ret);
+
+ p = strdupa(f);
+ if (!p)
+ return -ENOMEM;
+
+ path_simplify(p, false);
+
+ if (empty_or_root(p))
+ s = strdup("-");
+ else {
+ if (!path_is_normalized(p))
+ return -EINVAL;
+
+ /* Truncate trailing slashes */
+ delete_trailing_chars(p, "/");
+
+ /* Truncate leading slashes */
+ p = skip_leading_chars(p, "/");
+
+ s = unit_name_escape(p);
+ }
+ if (!s)
+ return -ENOMEM;
+
+ *ret = s;
+ return 0;
+}
+
+int unit_name_path_unescape(const char *f, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ int r;
+
+ assert(f);
+
+ if (isempty(f))
+ return -EINVAL;
+
+ if (streq(f, "-")) {
+ s = strdup("/");
+ if (!s)
+ return -ENOMEM;
+ } else {
+ _cleanup_free_ char *w = NULL;
+
+ r = unit_name_unescape(f, &w);
+ if (r < 0)
+ return r;
+
+ /* Don't accept trailing or leading slashes */
+ if (startswith(w, "/") || endswith(w, "/"))
+ return -EINVAL;
+
+ /* Prefix a slash again */
+ s = strjoin("/", w);
+ if (!s)
+ return -ENOMEM;
+
+ if (!path_is_normalized(s))
+ return -EINVAL;
+ }
+
+ if (ret)
+ *ret = TAKE_PTR(s);
+
+ return 0;
+}
+
+int unit_name_replace_instance(const char *f, const char *i, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ const char *p, *e;
+ size_t a, b;
+
+ assert(f);
+ assert(i);
+ assert(ret);
+
+ if (!unit_name_is_valid(f, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
+ return -EINVAL;
+ if (!unit_instance_is_valid(i))
+ return -EINVAL;
+
+ assert_se(p = strchr(f, '@'));
+ assert_se(e = strrchr(f, '.'));
+
+ a = p - f;
+ b = strlen(i);
+
+ s = new(char, a + 1 + b + strlen(e) + 1);
+ if (!s)
+ return -ENOMEM;
+
+ strcpy(mempcpy(mempcpy(s, f, a + 1), i, b), e);
+
+ /* Make sure the resulting name still is valid, i.e. didn't grow too large */
+ if (!unit_name_is_valid(s, UNIT_NAME_INSTANCE))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+int unit_name_template(const char *f, char **ret) {
+ const char *p, *e;
+ char *s;
+ size_t a;
+
+ assert(f);
+ assert(ret);
+
+ if (!unit_name_is_valid(f, UNIT_NAME_INSTANCE|UNIT_NAME_TEMPLATE))
+ return -EINVAL;
+
+ assert_se(p = strchr(f, '@'));
+ assert_se(e = strrchr(f, '.'));
+
+ a = p - f;
+
+ s = new(char, a + 1 + strlen(e) + 1);
+ if (!s)
+ return -ENOMEM;
+
+ strcpy(mempcpy(s, f, a + 1), e);
+
+ *ret = s;
+ return 0;
+}
+
+int unit_name_from_path(const char *path, const char *suffix, char **ret) {
+ _cleanup_free_ char *p = NULL, *s = NULL;
+ int r;
+
+ assert(path);
+ assert(suffix);
+ assert(ret);
+
+ if (!unit_suffix_is_valid(suffix))
+ return -EINVAL;
+
+ r = unit_name_path_escape(path, &p);
+ if (r < 0)
+ return r;
+
+ s = strjoin(p, suffix);
+ if (!s)
+ return -ENOMEM;
+
+ /* Refuse this if this got too long or for some other reason didn't result in a valid name */
+ if (!unit_name_is_valid(s, UNIT_NAME_PLAIN))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+int unit_name_from_path_instance(const char *prefix, const char *path, const char *suffix, char **ret) {
+ _cleanup_free_ char *p = NULL, *s = NULL;
+ int r;
+
+ assert(prefix);
+ assert(path);
+ assert(suffix);
+ assert(ret);
+
+ if (!unit_prefix_is_valid(prefix))
+ return -EINVAL;
+
+ if (!unit_suffix_is_valid(suffix))
+ return -EINVAL;
+
+ r = unit_name_path_escape(path, &p);
+ if (r < 0)
+ return r;
+
+ s = strjoin(prefix, "@", p, suffix);
+ if (!s)
+ return -ENOMEM;
+
+ /* Refuse this if this got too long or for some other reason didn't result in a valid name */
+ if (!unit_name_is_valid(s, UNIT_NAME_INSTANCE))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+int unit_name_to_path(const char *name, char **ret) {
+ _cleanup_free_ char *prefix = NULL;
+ int r;
+
+ assert(name);
+
+ r = unit_name_to_prefix(name, &prefix);
+ if (r < 0)
+ return r;
+
+ return unit_name_path_unescape(prefix, ret);
+}
+
+static bool do_escape_mangle(const char *f, bool allow_globs, char *t) {
+ const char *valid_chars;
+ bool mangled = false;
+
+ assert(f);
+ assert(t);
+
+ /* We'll only escape the obvious characters here, to play safe.
+ *
+ * Returns true if any characters were mangled, false otherwise.
+ */
+
+ valid_chars = allow_globs ? VALID_CHARS_GLOB : VALID_CHARS_WITH_AT;
+
+ for (; *f; f++)
+ if (*f == '/') {
+ *(t++) = '-';
+ mangled = true;
+ } else if (!strchr(valid_chars, *f)) {
+ t = do_escape_char(*f, t);
+ mangled = true;
+ } else
+ *(t++) = *f;
+ *t = 0;
+
+ return mangled;
+}
+
+/**
+ * Convert a string to a unit name. /dev/blah is converted to dev-blah.device,
+ * /blah/blah is converted to blah-blah.mount, anything else is left alone,
+ * except that @suffix is appended if a valid unit suffix is not present.
+ *
+ * If @allow_globs, globs characters are preserved. Otherwise, they are escaped.
+ */
+int unit_name_mangle_with_suffix(const char *name, const char *operation, UnitNameMangle flags, const char *suffix, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ bool mangled, suggest_escape = true;
+ int r;
+
+ assert(name);
+ assert(suffix);
+ assert(ret);
+
+ if (isempty(name)) /* We cannot mangle empty unit names to become valid, sorry. */
+ return -EINVAL;
+
+ if (!unit_suffix_is_valid(suffix))
+ return -EINVAL;
+
+ /* Already a fully valid unit name? If so, no mangling is necessary... */
+ if (unit_name_is_valid(name, UNIT_NAME_ANY))
+ goto good;
+
+ /* Already a fully valid globbing expression? If so, no mangling is necessary either... */
+ if (string_is_glob(name) && in_charset(name, VALID_CHARS_GLOB)) {
+ if (flags & UNIT_NAME_MANGLE_GLOB)
+ goto good;
+ log_full(flags & UNIT_NAME_MANGLE_WARN ? LOG_NOTICE : LOG_DEBUG,
+ "Glob pattern passed%s%s, but globs are not supported for this.",
+ operation ? " " : "", strempty(operation));
+ suggest_escape = false;
+ }
+
+ if (is_device_path(name)) {
+ r = unit_name_from_path(name, ".device", ret);
+ if (r >= 0)
+ return 1;
+ if (r != -EINVAL)
+ return r;
+ }
+
+ if (path_is_absolute(name)) {
+ r = unit_name_from_path(name, ".mount", ret);
+ if (r >= 0)
+ return 1;
+ if (r != -EINVAL)
+ return r;
+ }
+
+ s = new(char, strlen(name) * 4 + strlen(suffix) + 1);
+ if (!s)
+ return -ENOMEM;
+
+ mangled = do_escape_mangle(name, flags & UNIT_NAME_MANGLE_GLOB, s);
+ if (mangled)
+ log_full(flags & UNIT_NAME_MANGLE_WARN ? LOG_NOTICE : LOG_DEBUG,
+ "Invalid unit name \"%s\" escaped as \"%s\"%s.",
+ name, s,
+ suggest_escape ? " (maybe you should use systemd-escape?)" : "");
+
+ /* Append a suffix if it doesn't have any, but only if this is not a glob, so that we can allow
+ * "foo.*" as a valid glob. */
+ if ((!(flags & UNIT_NAME_MANGLE_GLOB) || !string_is_glob(s)) && unit_name_to_type(s) < 0)
+ strcat(s, suffix);
+
+ /* Make sure mangling didn't grow this too large (but don't do this check if globbing is allowed,
+ * since globs generally do not qualify as valid unit names) */
+ if (!FLAGS_SET(flags, UNIT_NAME_MANGLE_GLOB) && !unit_name_is_valid(s, UNIT_NAME_ANY))
+ return -EINVAL;
+
+ *ret = TAKE_PTR(s);
+ return 1;
+
+good:
+ s = strdup(name);
+ if (!s)
+ return -ENOMEM;
+
+ *ret = TAKE_PTR(s);
+ return 0;
+}
+
+int slice_build_parent_slice(const char *slice, char **ret) {
+ _cleanup_free_ char *s = NULL;
+ char *dash;
+ int r;
+
+ assert(slice);
+ assert(ret);
+
+ if (!slice_name_is_valid(slice))
+ return -EINVAL;
+
+ if (streq(slice, SPECIAL_ROOT_SLICE)) {
+ *ret = NULL;
+ return 0;
+ }
+
+ s = strdup(slice);
+ if (!s)
+ return -ENOMEM;
+
+ dash = strrchr(s, '-');
+ if (dash)
+ strcpy(dash, ".slice");
+ else {
+ r = free_and_strdup(&s, SPECIAL_ROOT_SLICE);
+ if (r < 0)
+ return r;
+ }
+
+ *ret = TAKE_PTR(s);
+ return 1;
+}
+
+int slice_build_subslice(const char *slice, const char *name, char **ret) {
+ char *subslice;
+
+ assert(slice);
+ assert(name);
+ assert(ret);
+
+ if (!slice_name_is_valid(slice))
+ return -EINVAL;
+
+ if (!unit_prefix_is_valid(name))
+ return -EINVAL;
+
+ if (streq(slice, SPECIAL_ROOT_SLICE))
+ subslice = strjoin(name, ".slice");
+ else {
+ char *e;
+
+ assert_se(e = endswith(slice, ".slice"));
+
+ subslice = new(char, (e - slice) + 1 + strlen(name) + 6 + 1);
+ if (!subslice)
+ return -ENOMEM;
+
+ stpcpy(stpcpy(stpcpy(mempcpy(subslice, slice, e - slice), "-"), name), ".slice");
+ }
+
+ *ret = subslice;
+ return 0;
+}
+
+bool slice_name_is_valid(const char *name) {
+ const char *p, *e;
+ bool dash = false;
+
+ if (!unit_name_is_valid(name, UNIT_NAME_PLAIN))
+ return false;
+
+ if (streq(name, SPECIAL_ROOT_SLICE))
+ return true;
+
+ e = endswith(name, ".slice");
+ if (!e)
+ return false;
+
+ for (p = name; p < e; p++) {
+
+ if (*p == '-') {
+
+ /* Don't allow initial dash */
+ if (p == name)
+ return false;
+
+ /* Don't allow multiple dashes */
+ if (dash)
+ return false;
+
+ dash = true;
+ } else
+ dash = false;
+ }
+
+ /* Don't allow trailing hash */
+ if (dash)
+ return false;
+
+ return true;
+}
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