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 #include "conf-files.h"
  35
  36 static int delete_rule(const char *rule) {
  37         char *x, *fn = NULL, *e;
  38         int r;
  39
  40         assert(rule[0]);
  41
  42         if (!(x = strdup(rule)))
  43                 return log_oom();
  44
  45         e = strchrnul(x+1, x[0]);
  46         *e = 0;
  47
  48         asprintf(&fn, "/proc/sys/fs/binfmt_misc/%s", x+1);
  49         free(x);
  50
  51         if (!fn)
  52                 return log_oom();
  53
  54         r = write_one_line_file(fn, "-1");
  55         free(fn);
  56
  57         return r;
  58 }
  59
  60 static int apply_rule(const char *rule) {
  61         int r;
  62
  63         delete_rule(rule);
  64
  65         if ((r = write_one_line_file("/proc/sys/fs/binfmt_misc/register", rule)) < 0) {
  66                 log_error("Failed to add binary format: %s", strerror(-r));
  67                 return r;
  68         }
  69
  70         return 0;
  71 }
  72
  73 static int apply_file(const char *path, bool ignore_enoent) {
  74         FILE *f;
  75         int r = 0;
  76
  77         assert(path);
  78
  79         if (!(f = fopen(path, "re"))) {
  80                 if (ignore_enoent && errno == ENOENT)
  81                         return 0;
  82
  83                 log_error("Failed to open file '%s', ignoring: %m", path);
  84                 return -errno;
  85         }
  86
  87         log_debug("apply: %s\n", path);
  88         while (!feof(f)) {
  89                 char l[LINE_MAX], *p;
  90                 int k;
  91
  92                 if (!fgets(l, sizeof(l), f)) {
  93                         if (feof(f))
  94                                 break;
  95
  96                         log_error("Failed to read file '%s', ignoring: %m", path);
  97                         r = -errno;
  98                         goto finish;
  99                 }
 100
 101                 p = strstrip(l);
 102
 103                 if (!*p)
 104                         continue;
 105
 106                 if (strchr(COMMENTS, *p))
 107                         continue;
 108
 109                 if ((k = apply_rule(p)) < 0 && r == 0)
 110                         r = k;
 111         }
 112
 113 finish:
 114         fclose(f);
 115
 116         return r;
 117 }
 118
 119 int main(int argc, char *argv[]) {
 120         int r = 0;
 121
 122         log_set_target(LOG_TARGET_AUTO);
 123         log_parse_environment();
 124         log_open();
 125
 126         umask(0022);
 127
 128         if (argc > 1) {
 129                 int i;
 130
 131                 for (i = 1; i < argc; i++) {
 132                         int k;
 133
 134                         k = apply_file(argv[i], false);
 135                         if (k < 0 && r == 0)
 136                                 r = k;
 137                 }
 138         } else {
 139                 char **files, **f;
 140
 141                 r = conf_files_list(&files, ".conf", NULL,
 142                                     "/etc/binfmt.d",
 143                                     "/run/binfmt.d",
 144                                     "/usr/local/lib/binfmt.d",
 145                                     "/usr/lib/binfmt.d",
 146 #ifdef HAVE_SPLIT_USR
 147                                     "/lib/binfmt.d",
 148 #endif
 149                                     NULL);
 150                 if (r < 0) {
 151                         log_error("Failed to enumerate binfmt.d files: %s", strerror(-r));
 152                         goto finish;
 153                 }
 154
 155                 /* Flush out all rules */
 156                 write_one_line_file("/proc/sys/fs/binfmt_misc/status", "-1");
 157
 158                 STRV_FOREACH(f, files) {
 159                         int k;
 160
 161                         k = apply_file(*f, true);
 162                         if (k < 0 && r == 0)
 163                                 r = k;
 164                 }
 165
 166                 strv_free(files);
 167         }
 168 finish:
 169         return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS;
 170 }