Adding upstream version 247.3.upstream/247.3upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 279 insertions, 0 deletions

diff --git a/src/shared/dropin.c b/src/shared/dropin.c
new file mode 100644
index 0000000..89f4b8a
--- /dev/null
+++ b/src/shared/dropin.c
@@ -0,0 +1,279 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "alloc-util.h"
+#include "conf-files.h"
+#include "dirent-util.h"
+#include "dropin.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "fileio-label.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "log.h"
+#include "macro.h"
+#include "mkdir.h"
+#include "path-util.h"
+#include "set.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+
+int drop_in_file(const char *dir, const char *unit, unsigned level,
+                 const char *name, char **ret_p, char **ret_q) {
+
+        char prefix[DECIMAL_STR_MAX(unsigned)];
+        _cleanup_free_ char *b = NULL, *p = NULL, *q = NULL;
+
+        assert(unit);
+        assert(name);
+        assert(ret_p);
+        assert(ret_q);
+
+        sprintf(prefix, "%u", level);
+
+        b = xescape(name, "/.");
+        if (!b)
+                return -ENOMEM;
+
+        if (!filename_is_valid(b))
+                return -EINVAL;
+
+        p = strjoin(dir, "/", unit, ".d");
+        q = strjoin(p, "/", prefix, "-", b, ".conf");
+        if (!p || !q)
+                return -ENOMEM;
+
+        *ret_p = TAKE_PTR(p);
+        *ret_q = TAKE_PTR(q);
+        return 0;
+}
+
+int write_drop_in(const char *dir, const char *unit, unsigned level,
+                  const char *name, const char *data) {
+
+        _cleanup_free_ char *p = NULL, *q = NULL;
+        int r;
+
+        assert(dir);
+        assert(unit);
+        assert(name);
+        assert(data);
+
+        r = drop_in_file(dir, unit, level, name, &p, &q);
+        if (r < 0)
+                return r;
+
+        (void) mkdir_p(p, 0755);
+        return write_string_file_atomic_label(q, data);
+}
+
+int write_drop_in_format(const char *dir, const char *unit, unsigned level,
+                         const char *name, const char *format, ...) {
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        assert(dir);
+        assert(unit);
+        assert(name);
+        assert(format);
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return write_drop_in(dir, unit, level, name, p);
+}
+
+static int unit_file_add_dir(
+                const char *original_root,
+                const char *path,
+                char ***dirs) {
+
+        _cleanup_free_ char *chased = NULL;
+        int r;
+
+        assert(path);
+
+        /* This adds [original_root]/path to dirs, if it exists. */
+
+        r = chase_symlinks(path, original_root, 0, &chased, NULL);
+        if (r == -ENOENT) /* Ignore -ENOENT, after all most units won't have a drop-in dir. */
+                return 0;
+        if (r == -ENAMETOOLONG) {
+                /* Also, ignore -ENAMETOOLONG but log about it. After all, users are not even able to create the
+                 * drop-in dir in such case. This mostly happens for device units with an overly long /sys path. */
+                log_debug_errno(r, "Path '%s' too long, couldn't canonicalize, ignoring.", path);
+                return 0;
+        }
+        if (r < 0)
+                return log_warning_errno(r, "Failed to canonicalize path '%s': %m", path);
+
+        if (strv_consume(dirs, TAKE_PTR(chased)) < 0)
+                return log_oom();
+
+        return 0;
+}
+
+static int unit_file_find_dirs(
+                const char *original_root,
+                Set *unit_path_cache,
+                const char *unit_path,
+                const char *name,
+                const char *suffix,
+                char ***dirs) {
+
+        _cleanup_free_ char *prefix = NULL, *instance = NULL, *built = NULL;
+        bool is_instance, chopped;
+        const char *dash;
+        UnitType type;
+        char *path;
+        size_t n;
+        int r;
+
+        assert(unit_path);
+        assert(name);
+        assert(suffix);
+
+        path = strjoina(unit_path, "/", name, suffix);
+        if (!unit_path_cache || set_get(unit_path_cache, path)) {
+                r = unit_file_add_dir(original_root, path, dirs);
+                if (r < 0)
+                        return r;
+        }
+
+        is_instance = unit_name_is_valid(name, UNIT_NAME_INSTANCE);
+        if (is_instance) { /* Also try the template dir */
+                _cleanup_free_ char *template = NULL;
+
+                r = unit_name_template(name, &template);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to generate template from unit name: %m");
+
+                r = unit_file_find_dirs(original_root, unit_path_cache, unit_path, template, suffix, dirs);
+                if (r < 0)
+                        return r;
+        }
+
+        /* Return early for top level drop-ins. */
+        if (unit_type_from_string(name) >= 0)
+                return 0;
+
+        /* Let's see if there's a "-" prefix for this unit name. If so, let's invoke ourselves for it. This will then
+         * recursively do the same for all our prefixes. i.e. this means given "foo-bar-waldo.service" we'll also
+         * search "foo-bar-.service" and "foo-.service".
+         *
+         * Note the order in which we do it: we traverse up adding drop-ins on each step. This means the more specific
+         * drop-ins may override the more generic drop-ins, which is the intended behaviour. */
+
+        r = unit_name_to_prefix(name, &prefix);
+        if (r < 0)
+                return log_error_errno(r, "Failed to derive unit name prefix from unit name: %m");
+
+        chopped = false;
+        for (;;) {
+                dash = strrchr(prefix, '-');
+                if (!dash) /* No dash? if so we are done */
+                        return 0;
+
+                n = (size_t) (dash - prefix);
+                if (n == 0) /* Leading dash? If so, we are done */
+                        return 0;
+
+                if (prefix[n+1] != 0 || chopped) {
+                        prefix[n+1] = 0;
+                        break;
+                }
+
+                /* Trailing dash? If so, chop it off and try again, but not more than once. */
+                prefix[n] = 0;
+                chopped = true;
+        }
+
+        if (!unit_prefix_is_valid(prefix))
+                return 0;
+
+        type = unit_name_to_type(name);
+        if (type < 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Failed to derive unit type from unit name: %s",
+                                       name);
+
+        if (is_instance) {
+                r = unit_name_to_instance(name, &instance);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to derive unit name instance from unit name: %m");
+        }
+
+        r = unit_name_build_from_type(prefix, instance, type, &built);
+        if (r < 0)
+                return log_error_errno(r, "Failed to build prefix unit name: %m");
+
+        return unit_file_find_dirs(original_root, unit_path_cache, unit_path, built, suffix, dirs);
+}
+
+int unit_file_find_dropin_paths(
+                const char *original_root,
+                char **lookup_path,
+                Set *unit_path_cache,
+                const char *dir_suffix,
+                const char *file_suffix,
+                const char *name,
+                const Set *aliases,
+                char ***ret) {
+
+        _cleanup_strv_free_ char **dirs = NULL;
+        const char *n;
+        char **p;
+        int r;
+
+        assert(ret);
+
+        if (name)
+                STRV_FOREACH(p, lookup_path)
+                        (void) unit_file_find_dirs(original_root, unit_path_cache, *p, name, dir_suffix, &dirs);
+
+        SET_FOREACH(n, aliases)
+                STRV_FOREACH(p, lookup_path)
+                        (void) unit_file_find_dirs(original_root, unit_path_cache, *p, n, dir_suffix, &dirs);
+
+        /* All the names in the unit are of the same type so just grab one. */
+        n = name ?: (const char*) set_first(aliases);
+        if (n) {
+                UnitType type = _UNIT_TYPE_INVALID;
+
+                type = unit_name_to_type(n);
+                if (type < 0)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "Failed to derive unit type from unit name: %s", n);
+
+                /* Special top level drop in for "<unit type>.<suffix>". Add this last as it's the most generic
+                 * and should be able to be overridden by more specific drop-ins. */
+                STRV_FOREACH(p, lookup_path)
+                        (void) unit_file_find_dirs(original_root,
+                                                   unit_path_cache,
+                                                   *p,
+                                                   unit_type_to_string(type),
+                                                   dir_suffix,
+                                                   &dirs);
+        }
+
+        if (strv_isempty(dirs)) {
+                *ret = NULL;
+                return 0;
+        }
+
+        r = conf_files_list_strv(ret, file_suffix, NULL, 0, (const char**) dirs);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to create the list of configuration files: %m");
+
+        return 1;
+}