sysctl: implement native sysctl tool to support Debian-style /etc/sysctl.d

1 files changed, 148 insertions, 0 deletions

diff --git a/src/sysctl.c b/src/sysctl.c
new file mode 100644
index 0000000000..c57210e28d
--- /dev/null
+++ b/src/sysctl.c
@@ -0,0 +1,148 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  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 <stdlib.h>
+#include <stdbool.h>
+#include <errno.h>
+#include <string.h>
+#include <ftw.h>
+#include <stdio.h>
+#include <limits.h>
+
+#include "log.h"
+#include "util.h"
+
+#define PROC_SYS_PREFIX "/proc/sys/"
+
+static int exit_code = 0;
+
+static void apply_sysctl(const char *property, const char *value) {
+        char *p, *n;
+        int r;
+
+        log_debug("Setting '%s' to '%s'", property, value);
+
+        if (!(p = new(char, sizeof(PROC_SYS_PREFIX) + strlen(property)))) {
+                log_error("Out of memory");
+                exit_code = -ENOMEM;
+        }
+
+        n = stpcpy(p, PROC_SYS_PREFIX);
+        strcpy(n, property);
+
+        for (; *n; n++)
+                if (*n == '.')
+                        *n = '/';
+
+        if ((r = write_one_line_file(p, value)) < 0) {
+                log_warning("Failed to write '%s' to '%s': %s", value, p, strerror(-r));
+                exit_code = r;
+        }
+
+        free(p);
+}
+
+static void apply_file(const char *path) {
+        FILE *f;
+
+        assert(path);
+
+        if (!(f = fopen(path, "re"))) {
+                log_error("Failed to open file '%s', ignoring: %m", path);
+                exit_code = -errno;
+                return;
+        }
+
+        while (!feof(f)) {
+                char l[LINE_MAX], *p, *value;
+
+                if (!fgets(l, sizeof(l), f)) {
+                        if (feof(f))
+                                break;
+
+                        log_error("Failed to read file '%s', ignoring: %m", path);
+                        exit_code = -errno;
+                        goto finish;
+                }
+
+                p = strstrip(l);
+
+                if (!*p)
+                        continue;
+
+                if (strchr(COMMENTS, *p))
+                        continue;
+
+                if (!(value = strchr(p, '='))) {
+                        log_error("Line is not an assignment in file '%s': %s", path, value);
+                        exit_code = -EINVAL;
+                        continue;
+                }
+
+                *value = 0;
+                value++;
+
+                apply_sysctl(strstrip(p), strstrip(value));
+        }
+
+finish:
+        fclose(f);
+}
+
+static int nftw_cb(
+                const char *fpath,
+                const struct stat *sb,
+                int tflag,
+                struct FTW *ftwbuf) {
+
+        if (tflag != FTW_F)
+                return 0;
+
+        if (ignore_file(fpath + ftwbuf->base))
+                return 0;
+
+        if (!endswith(fpath, ".conf"))
+                return 0;
+
+        apply_file(fpath);
+        return 0;
+};
+
+int main(int argc, char *argv[]) {
+
+        if (argc > 2) {
+                log_error("This program expects one or no arguments.");
+                return EXIT_FAILURE;
+        }
+
+        log_set_target(LOG_TARGET_AUTO);
+        log_parse_environment();
+        log_open();
+
+        if (argc > 1)
+                nftw(argv[1], nftw_cb, 64, FTW_MOUNT|FTW_PHYS);
+        else {
+                nftw("/etc/sysctl.conf", nftw_cb, 64, FTW_MOUNT|FTW_PHYS);
+                nftw("/etc/sysctl.d", nftw_cb, 64, FTW_MOUNT|FTW_PHYS);
+        }
+
+        return exit_code < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
+}