Move dropin listing to shared

No functional change. This is in preparation for using this in
systemctl in the future.

2 files changed, 165 insertions, 0 deletions

diff --git a/src/shared/dropin.c b/src/shared/dropin.c
index c5c4f95719..40e6fee1c4 100644
--- a/src/shared/dropin.c
+++ b/src/shared/dropin.c
@@ -21,8 +21,10 @@
 
 #include "dropin.h"
 #include "util.h"
+#include "strv.h"
 #include "mkdir.h"
 #include "fileio-label.h"
+#include "conf-files.h"
 
 int drop_in_file(const char *dir, const char *unit, unsigned level,
                  const char *name, char **_p, char **_q) {
@@ -100,3 +102,137 @@ int write_drop_in_format(const char *dir, const char *unit, unsigned level,
 
         return write_drop_in(dir, unit, level, name, p);
 }
+
+static int iterate_dir(
+                const char *path,
+                UnitDependency dependency,
+                dependency_consumer_t consumer,
+                void *arg,
+                char ***strv) {
+
+        _cleanup_closedir_ DIR *d = NULL;
+        int r;
+
+        assert(path);
+
+        /* The config directories are special, since the order of the
+         * drop-ins matters */
+        if (dependency < 0)  {
+                r = strv_extend(strv, path);
+                if (r < 0)
+                        return log_oom();
+
+                return 0;
+        }
+
+        assert(consumer);
+
+        d = opendir(path);
+        if (!d) {
+                if (errno == ENOENT)
+                        return 0;
+
+                log_error_errno(errno, "Failed to open directory %s: %m", path);
+                return -errno;
+        }
+
+        for (;;) {
+                struct dirent *de;
+                _cleanup_free_ char *f = NULL;
+
+                errno = 0;
+                de = readdir(d);
+                if (!de && errno != 0)
+                        return log_error_errno(errno, "Failed to read directory %s: %m", path);
+
+                if (!de)
+                        break;
+
+                if (ignore_file(de->d_name))
+                        continue;
+
+                f = strjoin(path, "/", de->d_name, NULL);
+                if (!f)
+                        return log_oom();
+
+                r = consumer(dependency, de->d_name, f, arg);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int unit_file_process_dir(
+                Set * unit_path_cache,
+                const char *unit_path,
+                const char *name,
+                const char *suffix,
+                UnitDependency dependency,
+                dependency_consumer_t consumer,
+                void *arg,
+                char ***strv) {
+
+        _cleanup_free_ char *path = NULL;
+
+        assert(unit_path);
+        assert(name);
+        assert(suffix);
+
+        path = strjoin(unit_path, "/", name, suffix, NULL);
+        if (!path)
+                return log_oom();
+
+        if (!unit_path_cache || set_get(unit_path_cache, path))
+                iterate_dir(path, dependency, consumer, arg, strv);
+
+        if (unit_name_is_instance(name)) {
+                _cleanup_free_ char *template = NULL, *p = NULL;
+                /* Also try the template dir */
+
+                template = unit_name_template(name);
+                if (!template)
+                        return log_oom();
+
+                p = strjoin(unit_path, "/", template, suffix, NULL);
+                if (!p)
+                        return log_oom();
+
+                if (!unit_path_cache || set_get(unit_path_cache, p))
+                        iterate_dir(p, dependency, consumer, arg, strv);
+        }
+
+        return 0;
+}
+
+int unit_file_find_dropin_paths(
+                char **lookup_path,
+                Set *unit_path_cache,
+                Set *names,
+                char ***paths) {
+
+        _cleanup_strv_free_ char **strv = NULL, **ans = NULL;
+        Iterator i;
+        char *t;
+        int r;
+
+        assert(paths);
+
+        SET_FOREACH(t, names, i) {
+                char **p;
+
+                STRV_FOREACH(p, lookup_path)
+                        unit_file_process_dir(unit_path_cache, *p, t, ".d", _UNIT_DEPENDENCY_INVALID, NULL, NULL, &strv);
+        }
+
+        if (strv_isempty(strv))
+                return 0;
+
+        r = conf_files_list_strv(&ans, ".conf", NULL, (const char**) strv);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to get list of configuration files: %m");
+
+        *paths = ans;
+        ans = NULL;
+        return 1;
+}
diff --git a/src/shared/dropin.h b/src/shared/dropin.h
index 9c9742d0e4..d4531fca2d 100644
--- a/src/shared/dropin.h
+++ b/src/shared/dropin.h
@@ -22,6 +22,8 @@
 ***/
 
 #include "macro.h"
+#include "set.h"
+#include "unit-name.h"
 
 int drop_in_file(const char *dir, const char *unit, unsigned level,
                  const char *name, char **_p, char **_q);
@@ -31,3 +33,30 @@ int write_drop_in(const char *dir, const char *unit, unsigned level,
 
 int write_drop_in_format(const char *dir, const char *unit, unsigned level,
                          const char *name, const char *format, ...) _printf_(5, 6);
+
+/**
+ * This callback will be called for each directory entry @entry,
+ * with @filepath being the full path to the entry.
+ *
+ * If return value is negative, loop will be aborted.
+ */
+typedef int (*dependency_consumer_t)(UnitDependency dependency,
+                                     const char *entry,
+                                     const char* filepath,
+                                     void *arg);
+
+int unit_file_process_dir(
+                Set * unit_path_cache,
+                const char *unit_path,
+                const char *name,
+                const char *suffix,
+                UnitDependency dependency,
+                dependency_consumer_t consumer,
+                void *arg,
+                char ***strv);
+
+int unit_file_find_dropin_paths(
+                char **lookup_path,
+                Set *unit_path_cache,
+                Set *names,
+                char ***paths);