src/sysctl.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU General Public License as published by
  10   the Free Software Foundation; either version 2 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   General Public License for more details.
  17
  18   You should have received a copy of the GNU General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <stdlib.h>
  23 #include <stdbool.h>
  24 #include <errno.h>
  25 #include <string.h>
  26 #include <stdio.h>
  27 #include <limits.h>
  28
  29 #include "log.h"
  30 #include "strv.h"
  31 #include "util.h"
  32
  33 #define PROC_SYS_PREFIX "/proc/sys/"
  34
  35 static int apply_sysctl(const char *property, const char *value) {
  36         char *p, *n;
  37         int r = 0, k;
  38
  39         log_debug("Setting '%s' to '%s'", property, value);
  40
  41         if (!(p = new(char, sizeof(PROC_SYS_PREFIX) + strlen(property)))) {
  42                 log_error("Out of memory");
  43                 return -ENOMEM;
  44         }
  45
  46         n = stpcpy(p, PROC_SYS_PREFIX);
  47         strcpy(n, property);
  48
  49         for (; *n; n++)
  50                 if (*n == '.')
  51                         *n = '/';
  52
  53         if ((k = write_one_line_file(p, value)) < 0) {
  54
  55                 log_full(k == -ENOENT ? LOG_DEBUG : LOG_WARNING,
  56                          "Failed to write '%s' to '%s': %s", value, p, strerror(-k));
  57
  58                 if (k != -ENOENT && r == 0)
  59                         r = k;
  60         }
  61
  62         free(p);
  63
  64         return r;
  65 }
  66
  67 static int apply_file(const char *path, bool ignore_enoent) {
  68         FILE *f;
  69         int r = 0;
  70
  71         assert(path);
  72
  73         if (!(f = fopen(path, "re"))) {
  74                 if (ignore_enoent && errno == ENOENT)
  75                         return 0;
  76
  77                 log_error("Failed to open file '%s', ignoring: %m", path);
  78                 return -errno;
  79         }
  80
  81         log_debug("apply: %s\n", path);
  82         while (!feof(f)) {
  83                 char l[LINE_MAX], *p, *value;
  84                 int k;
  85
  86                 if (!fgets(l, sizeof(l), f)) {
  87                         if (feof(f))
  88                                 break;
  89
  90                         log_error("Failed to read file '%s', ignoring: %m", path);
  91                         r = -errno;
  92                         goto finish;
  93                 }
  94
  95                 p = strstrip(l);
  96
  97                 if (!*p)
  98                         continue;
  99
 100                 if (strchr(COMMENTS, *p))
 101                         continue;
 102
 103                 if (!(value = strchr(p, '='))) {
 104                         log_error("Line is not an assignment in file '%s': %s", path, value);
 105
 106                         if (r == 0)
 107                                 r = -EINVAL;
 108                         continue;
 109                 }
 110
 111                 *value = 0;
 112                 value++;
 113
 114                 if ((k = apply_sysctl(strstrip(p), strstrip(value))) < 0 && r == 0)
 115                         r = k;
 116         }
 117
 118 finish:
 119         fclose(f);
 120
 121         return r;
 122 }
 123
 124 int main(int argc, char *argv[]) {
 125         int r = 0;
 126
 127         if (argc > 2) {
 128                 log_error("This program expects one or no arguments.");
 129                 return EXIT_FAILURE;
 130         }
 131
 132         log_set_target(LOG_TARGET_AUTO);
 133         log_parse_environment();
 134         log_open();
 135
 136         if (argc > 1)
 137                 r = apply_file(argv[1], false);
 138         else {
 139                 char **files, **f;
 140
 141
 142                 r = conf_files_list(&files, ".conf",
 143                                     "/run/sysctl.d",
 144                                     "/etc/sysctl.d",
 145                                     "/usr/local/lib/sysctl.d",
 146                                     "/usr/lib/sysctl.d",
 147                                     "/lib/sysctl.d",
 148                                     NULL);
 149                 if (r < 0) {
 150                         log_error("Failed to enumerate sysctl.d files: %s", strerror(-r));
 151                         goto finish;
 152                 }
 153
 154                 STRV_FOREACH(f, files) {
 155                         int k;
 156
 157                         k = apply_file(*f, true);
 158                         if (k < 0 && r == 0)
 159                                 r = k;
 160                 }
 161
 162                 apply_file("/etc/sysctl.conf", true);
 163
 164                 strv_free(files);
 165         }
 166 finish:
 167         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 168 }