manager: split off path lookup logic into own .c file

1 files changed, 269 insertions, 0 deletions

diff --git a/src/path-lookup.c b/src/path-lookup.c
new file mode 100644
index 0000000000..1c4b5dc4e1
--- /dev/null
+++ b/src/path-lookup.c
@@ -0,0 +1,269 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "util.h"
+#include "strv.h"
+
+#include "path-lookup.h"
+
+static char** session_dirs(void) {
+        const char *home, *e;
+        char *config_home = NULL, *data_home = NULL;
+        char **config_dirs = NULL, **data_dirs = NULL;
+        char **r = NULL, **t;
+
+        /* Implement the mechanisms defined in
+         *
+         * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
+         *
+         * We look in both the config and the data dirs because we
+         * want to encourage that distributors ship their unit files
+         * as data, and allow overriding as configuration.
+         */
+
+        home = getenv("HOME");
+
+        if ((e = getenv("XDG_CONFIG_HOME"))) {
+                if (asprintf(&config_home, "%s/systemd/session", e) < 0)
+                        goto fail;
+
+        } else if (home) {
+                if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
+                        goto fail;
+        }
+
+        if ((e = getenv("XDG_CONFIG_DIRS")))
+                if (!(config_dirs = strv_split(e, ":")))
+                        goto fail;
+
+        /* We don't treat /etc/xdg/systemd here as the spec
+         * suggests because we assume that that is a link to
+         * /etc/systemd/ anyway. */
+
+        if ((e = getenv("XDG_DATA_HOME"))) {
+                if (asprintf(&data_home, "%s/systemd/session", e) < 0)
+                        goto fail;
+
+        } else if (home) {
+                if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
+                        goto fail;
+
+                /* There is really no need for two unit dirs in $HOME,
+                 * except to be fully compliant with the XDG spec. We
+                 * now try to link the two dirs, so that we can
+                 * minimize disk seeks a little. Further down we'll
+                 * then filter out this link, if it is actually is
+                 * one. */
+
+                mkdir_parents(data_home, 0777);
+                symlink("../../../.config/systemd/session", data_home);
+        }
+
+        if ((e = getenv("XDG_DATA_DIRS")))
+                data_dirs = strv_split(e, ":");
+        else
+                data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
+
+        if (!data_dirs)
+                goto fail;
+
+        /* Now merge everything we found. */
+        if (config_home) {
+                if (!(t = strv_append(r, config_home)))
+                        goto fail;
+                strv_free(r);
+                r = t;
+        }
+
+        if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
+                goto finish;
+        strv_free(r);
+        r = t;
+
+        if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
+                goto fail;
+        strv_free(r);
+        r = t;
+
+        if (data_home) {
+                if (!(t = strv_append(r, data_home)))
+                        goto fail;
+                strv_free(r);
+                r = t;
+        }
+
+        if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
+                goto fail;
+        strv_free(r);
+        r = t;
+
+        if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
+                goto fail;
+        strv_free(r);
+        r = t;
+
+        if (!strv_path_make_absolute_cwd(r))
+            goto fail;
+
+finish:
+        free(config_home);
+        strv_free(config_dirs);
+        free(data_home);
+        strv_free(data_dirs);
+
+        return r;
+
+fail:
+        strv_free(r);
+        r = NULL;
+        goto finish;
+}
+
+int lookup_paths_init(LookupPaths *p, ManagerRunningAs running_as) {
+        const char *e;
+        char *t;
+
+        assert(p);
+
+        /* First priority is whatever has been passed to us via env
+         * vars */
+        if ((e = getenv("SYSTEMD_UNIT_PATH")))
+                if (!(p->unit_path = split_path_and_make_absolute(e)))
+                        return -ENOMEM;
+
+        if (strv_isempty(p->unit_path)) {
+
+                /* Nothing is set, so let's figure something out. */
+                strv_free(p->unit_path);
+
+                if (running_as == MANAGER_SESSION) {
+                        if (!(p->unit_path = session_dirs()))
+                                return -ENOMEM;
+                } else
+                        if (!(p->unit_path = strv_new(
+                                              SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
+                                              SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
+                                              NULL)))
+                                return -ENOMEM;
+        }
+
+        if (running_as == MANAGER_INIT) {
+                /* /etc/init.d/ compatibility does not matter to users */
+
+                if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
+                        if (!(p->sysvinit_path = split_path_and_make_absolute(e)))
+                                return -ENOMEM;
+
+                if (strv_isempty(p->sysvinit_path)) {
+                        strv_free(p->sysvinit_path);
+
+                        if (!(p->sysvinit_path = strv_new(
+                                              SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
+                                              NULL)))
+                                return -ENOMEM;
+                }
+
+                if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
+                        if (!(p->sysvrcnd_path = split_path_and_make_absolute(e)))
+                                return -ENOMEM;
+
+                if (strv_isempty(p->sysvrcnd_path)) {
+                        strv_free(p->sysvrcnd_path);
+
+                        if (!(p->sysvrcnd_path = strv_new(
+                                              SYSTEM_SYSVRCND_PATH,     /* /etc/rcN.d/ */
+                                              NULL)))
+                                return -ENOMEM;
+                }
+        }
+
+        if (p->unit_path)
+                if (!strv_path_canonicalize(p->unit_path))
+                        return -ENOMEM;
+
+        if (p->sysvinit_path)
+                if (!strv_path_canonicalize(p->sysvinit_path))
+                        return -ENOMEM;
+
+        if (p->sysvrcnd_path)
+                if (!strv_path_canonicalize(p->sysvrcnd_path))
+                        return -ENOMEM;
+
+        strv_uniq(p->unit_path);
+        strv_uniq(p->sysvinit_path);
+        strv_uniq(p->sysvrcnd_path);
+
+        if (!strv_isempty(p->unit_path)) {
+
+                if (!(t = strv_join(p->unit_path, "\n\t")))
+                        return -ENOMEM;
+                log_debug("Looking for unit files in:\n\t%s", t);
+                free(t);
+        } else {
+                log_debug("Ignoring unit files.");
+                strv_free(p->unit_path);
+                p->unit_path = NULL;
+        }
+
+        if (!strv_isempty(p->sysvinit_path)) {
+
+                if (!(t = strv_join(p->sysvinit_path, "\n\t")))
+                        return -ENOMEM;
+
+                log_debug("Looking for SysV init scripts in:\n\t%s", t);
+                free(t);
+        } else {
+                log_debug("Ignoring SysV init scripts.");
+                strv_free(p->sysvinit_path);
+                p->sysvinit_path = NULL;
+        }
+
+        if (!strv_isempty(p->sysvrcnd_path)) {
+
+                if (!(t = strv_join(p->sysvrcnd_path, "\n\t")))
+                        return -ENOMEM;
+
+                log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
+                free(t);
+        } else {
+                log_debug("Ignoring SysV rcN.d links.");
+                strv_free(p->sysvrcnd_path);
+                p->sysvrcnd_path = NULL;
+        }
+
+        return 0;
+}
+
+void lookup_paths_free(LookupPaths *p) {
+        assert(p);
+
+        strv_free(p->unit_path);
+        strv_free(p->sysvinit_path);
+        strv_free(p->sysvrcnd_path);
+
+        p->unit_path = p->sysvinit_path = p->sysvrcnd_path = NULL;
+}