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 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 <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[1], 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 }