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 #include <getopt.h>
  29
  30 #include "log.h"
  31 #include "strv.h"
  32 #include "util.h"
  33 #include "strv.h"
  34
  35 #define PROC_SYS_PREFIX "/proc/sys/"
  36
  37 static char **arg_prefixes = NULL;
  38
  39 static int apply_sysctl(const char *property, const char *value) {
  40         char *p, *n;
  41         int r = 0, k;
  42
  43         log_debug("Setting '%s' to '%s'", property, value);
  44
  45         p = new(char, sizeof(PROC_SYS_PREFIX) + strlen(property));
  46         if (!p) {
  47                 log_error("Out of memory");
  48                 return -ENOMEM;
  49         }
  50
  51         n = stpcpy(p, PROC_SYS_PREFIX);
  52         strcpy(n, property);
  53
  54         for (; *n; n++)
  55                 if (*n == '.')
  56                         *n = '/';
  57
  58         if (!strv_isempty(arg_prefixes)) {
  59                 char **i;
  60                 bool good = false;
  61
  62                 STRV_FOREACH(i, arg_prefixes)
  63                         if (path_startswith(p, *i)) {
  64                                 good = true;
  65                                 break;
  66                         }
  67
  68                 if (!good) {
  69                         log_debug("Skipping %s", p);
  70                         free(p);
  71                         return 0;
  72                 }
  73         }
  74
  75         k = write_one_line_file(p, value);
  76         if (k < 0) {
  77
  78                 log_full(k == -ENOENT ? LOG_DEBUG : LOG_WARNING,
  79                          "Failed to write '%s' to '%s': %s", value, p, strerror(-k));
  80
  81                 if (k != -ENOENT && r == 0)
  82                         r = k;
  83         }
  84
  85         free(p);
  86
  87         return r;
  88 }
  89
  90 static int apply_file(const char *path, bool ignore_enoent) {
  91         FILE *f;
  92         int r = 0;
  93
  94         assert(path);
  95
  96         if (!(f = fopen(path, "re"))) {
  97                 if (ignore_enoent && errno == ENOENT)
  98                         return 0;
  99
 100                 log_error("Failed to open file '%s', ignoring: %m", path);
 101                 return -errno;
 102         }
 103
 104         log_debug("apply: %s\n", path);
 105         while (!feof(f)) {
 106                 char l[LINE_MAX], *p, *value;
 107                 int k;
 108
 109                 if (!fgets(l, sizeof(l), f)) {
 110                         if (feof(f))
 111                                 break;
 112
 113                         log_error("Failed to read file '%s', ignoring: %m", path);
 114                         r = -errno;
 115                         goto finish;
 116                 }
 117
 118                 p = strstrip(l);
 119
 120                 if (!*p)
 121                         continue;
 122
 123                 if (strchr(COMMENTS, *p))
 124                         continue;
 125
 126                 if (!(value = strchr(p, '='))) {
 127                         log_error("Line is not an assignment in file '%s': %s", path, value);
 128
 129                         if (r == 0)
 130                                 r = -EINVAL;
 131                         continue;
 132                 }
 133
 134                 *value = 0;
 135                 value++;
 136
 137                 if ((k = apply_sysctl(strstrip(p), strstrip(value))) < 0 && r == 0)
 138                         r = k;
 139         }
 140
 141 finish:
 142         fclose(f);
 143
 144         return r;
 145 }
 146
 147 static int help(void) {
 148
 149         printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n"
 150                "Applies kernel sysctl settings.\n\n"
 151                "  -h --help             Show this help\n"
 152                "     --prefix=PATH      Only apply rules that apply to paths with the specified prefix\n",
 153                program_invocation_short_name);
 154
 155         return 0;
 156 }
 157
 158 static int parse_argv(int argc, char *argv[]) {
 159
 160         enum {
 161                 ARG_PREFIX
 162         };
 163
 164         static const struct option options[] = {
 165                 { "help",      no_argument,       NULL, 'h'           },
 166                 { "prefix",    required_argument, NULL, ARG_PREFIX    },
 167                 { NULL,        0,                 NULL, 0             }
 168         };
 169
 170         int c;
 171
 172         assert(argc >= 0);
 173         assert(argv);
 174
 175         while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
 176
 177                 switch (c) {
 178
 179                 case 'h':
 180                         help();
 181                         return 0;
 182
 183                 case ARG_PREFIX: {
 184                         char *p;
 185                         char **l;
 186
 187                         for (p = optarg; *p; p++)
 188                                 if (*p == '.')
 189                                         *p = '/';
 190
 191                         l = strv_append(arg_prefixes, optarg);
 192                         if (!l) {
 193                                 log_error("Out of memory");
 194                                 return -ENOMEM;
 195                         }
 196
 197                         strv_free(arg_prefixes);
 198                         arg_prefixes = l;
 199
 200                         break;
 201                 }
 202
 203                 case '?':
 204                         return -EINVAL;
 205
 206                 default:
 207                         log_error("Unknown option code %c", c);
 208                         return -EINVAL;
 209                 }
 210         }
 211
 212         return 1;
 213 }
 214
 215 int main(int argc, char *argv[]) {
 216         int r = 0;
 217
 218         r = parse_argv(argc, argv);
 219         if (r <= 0)
 220                 return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 221
 222         if (argc-optind > 1) {
 223                 log_error("This program expects one or no arguments.");
 224                 return EXIT_FAILURE;
 225         }
 226
 227         log_set_target(LOG_TARGET_AUTO);
 228         log_parse_environment();
 229         log_open();
 230
 231         umask(0022);
 232
 233         if (argc > optind)
 234                 r = apply_file(argv[optind], false);
 235         else {
 236                 char **files, **f;
 237
 238                 r = conf_files_list(&files, ".conf",
 239                                     "/run/sysctl.d",
 240                                     "/etc/sysctl.d",
 241                                     "/usr/local/lib/sysctl.d",
 242                                     "/usr/lib/sysctl.d",
 243                                     "/lib/sysctl.d",
 244                                     NULL);
 245                 if (r < 0) {
 246                         log_error("Failed to enumerate sysctl.d files: %s", strerror(-r));
 247                         goto finish;
 248                 }
 249
 250                 STRV_FOREACH(f, files) {
 251                         int k;
 252
 253                         k = apply_file(*f, true);
 254                         if (k < 0 && r == 0)
 255                                 r = k;
 256                 }
 257
 258                 apply_file("/etc/sysctl.conf", true);
 259
 260                 strv_free(files);
 261         }
 262 finish:
 263         strv_free(arg_prefixes);
 264
 265         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 266 }