src/binfmt/binfmt.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 Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 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   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser 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 <stdarg.h>
  29
  30 #include "log.h"
  31 #include "hashmap.h"
  32 #include "strv.h"
  33 #include "util.h"
  34
  35 static int delete_rule(const char *rule) {
  36         char *x, *fn = NULL, *e;
  37         int r;
  38
  39         assert(rule[0]);
  40
  41         if (!(x = strdup(rule)))
  42                 return -ENOMEM;
  43
  44         e = strchrnul(x+1, x[0]);
  45         *e = 0;
  46
  47         asprintf(&fn, "/proc/sys/fs/binfmt_misc/%s", x+1);
  48         free(x);
  49
  50         if (!fn)
  51                 return -ENOMEM;
  52
  53         r = write_one_line_file(fn, "-1");
  54         free(fn);
  55
  56         return r;
  57 }
  58
  59 static int apply_rule(const char *rule) {
  60         int r;
  61
  62         delete_rule(rule);
  63
  64         if ((r = write_one_line_file("/proc/sys/fs/binfmt_misc/register", rule)) < 0) {
  65                 log_error("Failed to add binary format: %s", strerror(-r));
  66                 return r;
  67         }
  68
  69         return 0;
  70 }
  71
  72 static int apply_file(const char *path, bool ignore_enoent) {
  73         FILE *f;
  74         int r = 0;
  75
  76         assert(path);
  77
  78         if (!(f = fopen(path, "re"))) {
  79                 if (ignore_enoent && errno == ENOENT)
  80                         return 0;
  81
  82                 log_error("Failed to open file '%s', ignoring: %m", path);
  83                 return -errno;
  84         }
  85
  86         log_debug("apply: %s\n", path);
  87         while (!feof(f)) {
  88                 char l[LINE_MAX], *p;
  89                 int k;
  90
  91                 if (!fgets(l, sizeof(l), f)) {
  92                         if (feof(f))
  93                                 break;
  94
  95                         log_error("Failed to read file '%s', ignoring: %m", path);
  96                         r = -errno;
  97                         goto finish;
  98                 }
  99
 100                 p = strstrip(l);
 101
 102                 if (!*p)
 103                         continue;
 104
 105                 if (strchr(COMMENTS, *p))
 106                         continue;
 107
 108                 if ((k = apply_rule(p)) < 0 && r == 0)
 109                         r = k;
 110         }
 111
 112 finish:
 113         fclose(f);
 114
 115         return r;
 116 }
 117
 118 int main(int argc, char *argv[]) {
 119         int r = 0;
 120
 121         log_set_target(LOG_TARGET_AUTO);
 122         log_parse_environment();
 123         log_open();
 124
 125         umask(0022);
 126
 127         if (argc > 1) {
 128                 int i;
 129
 130                 for (i = 1; i < argc; i++) {
 131                         int k;
 132
 133                         k = apply_file(argv[i], false);
 134                         if (k < 0 && r == 0)
 135                                 r = k;
 136                 }
 137         } else {
 138                 char **files, **f;
 139
 140                 r = conf_files_list(&files, ".conf",
 141                                     "/etc/binfmt.d",
 142                                     "/run/binfmt.d",
 143                                     "/usr/local/lib/binfmt.d",
 144                                     "/usr/lib/binfmt.d",
 145 #ifdef HAVE_SPLIT_USR
 146                                     "/lib/binfmt.d",
 147 #endif
 148                                     NULL);
 149                 if (r < 0) {
 150                         log_error("Failed to enumerate binfmt.d files: %s", strerror(-r));
 151                         goto finish;
 152                 }
 153
 154                 /* Flush out all rules */
 155                 write_one_line_file("/proc/sys/fs/binfmt_misc/status", "-1");
 156
 157                 STRV_FOREACH(f, files) {
 158                         int k;
 159
 160                         k = apply_file(*f, true);
 161                         if (k < 0 && r == 0)
 162                                 r = k;
 163                 }
 164
 165                 strv_free(files);
 166         }
 167 finish:
 168         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 169 }