/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include #include "alloc-util.h" #include "binfmt-util.h" #include "build.h" #include "conf-files.h" #include "constants.h" #include "errno-util.h" #include "fd-util.h" #include "fileio.h" #include "log.h" #include "main-func.h" #include "pager.h" #include "path-util.h" #include "pretty-print.h" #include "string-util.h" #include "strv.h" static CatFlags arg_cat_flags = CAT_CONFIG_OFF; static PagerFlags arg_pager_flags = 0; static bool arg_unregister = false; static int delete_rule(const char *rulename) { const char *fn = strjoina("/proc/sys/fs/binfmt_misc/", rulename); return write_string_file(fn, "-1", WRITE_STRING_FILE_DISABLE_BUFFER); } static int apply_rule(const char *filename, unsigned line, const char *rule) { assert(filename); assert(line > 0); assert(rule); assert(rule[0]); _cleanup_free_ char *rulename = NULL; int r; rulename = strdupcspn(rule + 1, CHAR_TO_STR(rule[0])); if (!rulename) return log_oom(); if (!filename_is_valid(rulename) || STR_IN_SET(rulename, "register", "status")) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "%s:%u: Rule name '%s' is not valid, refusing.", filename, line, rulename); r = delete_rule(rulename); if (r < 0 && r != -ENOENT) log_warning_errno(r, "%s:%u: Failed to delete rule '%s', ignoring: %m", filename, line, rulename); if (r >= 0) log_debug("%s:%u: Rule '%s' deleted.", filename, line, rulename); r = write_string_file("/proc/sys/fs/binfmt_misc/register", rule, WRITE_STRING_FILE_DISABLE_BUFFER); if (r < 0) return log_error_errno(r, "%s:%u: Failed to add binary format '%s': %m", filename, line, rulename); log_debug("%s:%u: Binary format '%s' registered.", filename, line, rulename); return 0; } static int apply_file(const char *filename, bool ignore_enoent) { _cleanup_fclose_ FILE *f = NULL; _cleanup_free_ char *pp = NULL; int r; assert(filename); r = search_and_fopen(filename, "re", NULL, (const char**) CONF_PATHS_STRV("binfmt.d"), &f, &pp); if (r < 0) { if (ignore_enoent && r == -ENOENT) return 0; return log_error_errno(r, "Failed to open file '%s': %m", filename); } log_debug("Applying %s%s", pp, glyph(GLYPH_ELLIPSIS)); for (unsigned line = 1;; line++) { _cleanup_free_ char *text = NULL; int k; k = read_stripped_line(f, LONG_LINE_MAX, &text); if (k < 0) return log_error_errno(k, "Failed to read file '%s': %m", pp); if (k == 0) break; if (isempty(text)) continue; if (strchr(COMMENTS, text[0])) continue; RET_GATHER(r, apply_rule(filename, line, text)); } return r; } static int cat_config(char **files) { pager_open(arg_pager_flags); return cat_files(NULL, files, arg_cat_flags); } static int help(void) { _cleanup_free_ char *link = NULL; int r; r = terminal_urlify_man("systemd-binfmt.service", "8", &link); if (r < 0) return log_oom(); printf("%s [OPTIONS...] [CONFIGURATION FILE...]\n\n" "Registers binary formats with the kernel.\n\n" " -h --help Show this help\n" " --version Show package version\n" " --cat-config Show configuration files\n" " --tldr Show non-comment parts of configuration\n" " --no-pager Do not pipe output into a pager\n" " --unregister Unregister all existing entries\n" "\nSee the %s for details.\n", program_invocation_short_name, link); return 0; } static int parse_argv(int argc, char *argv[]) { enum { ARG_VERSION = 0x100, ARG_CAT_CONFIG, ARG_TLDR, ARG_NO_PAGER, ARG_UNREGISTER, }; static const struct option options[] = { { "help", no_argument, NULL, 'h' }, { "version", no_argument, NULL, ARG_VERSION }, { "cat-config", no_argument, NULL, ARG_CAT_CONFIG }, { "tldr", no_argument, NULL, ARG_TLDR }, { "no-pager", no_argument, NULL, ARG_NO_PAGER }, { "unregister", no_argument, NULL, ARG_UNREGISTER }, {} }; int c; assert(argc >= 0); assert(argv); while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) switch (c) { case 'h': return help(); case ARG_VERSION: return version(); case ARG_CAT_CONFIG: arg_cat_flags = CAT_CONFIG_ON; break; case ARG_TLDR: arg_cat_flags = CAT_TLDR; break; case ARG_NO_PAGER: arg_pager_flags |= PAGER_DISABLE; break; case ARG_UNREGISTER: arg_unregister = true; break; case '?': return -EINVAL; default: assert_not_reached(); } if ((arg_unregister || arg_cat_flags != CAT_CONFIG_OFF) && argc > optind) return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Positional arguments are not allowed with --cat-config/--tldr or --unregister."); return 1; } static int binfmt_mounted_and_writable_warn(void) { int r; r = binfmt_mounted_and_writable(); if (r < 0) return log_error_errno(r, "Failed to check if /proc/sys/fs/binfmt_misc is mounted: %m"); if (r == 0) log_debug("/proc/sys/fs/binfmt_misc is not mounted in read-write mode, skipping."); return r; } static int run(int argc, char *argv[]) { int r; r = parse_argv(argc, argv); if (r <= 0) return r; log_setup(); umask(0022); r = 0; if (arg_unregister) return disable_binfmt(); if (argc > optind) { r = binfmt_mounted_and_writable_warn(); if (r <= 0) return r; for (int i = optind; i < argc; i++) RET_GATHER(r, apply_file(argv[i], false)); } else { _cleanup_strv_free_ char **files = NULL; r = conf_files_list_strv(&files, ".conf", /* root= */ NULL, CONF_FILES_WARN, (const char**) CONF_PATHS_STRV("binfmt.d")); if (r < 0) return log_error_errno(r, "Failed to enumerate binfmt.d files: %m"); if (arg_cat_flags != CAT_CONFIG_OFF) return cat_config(files); r = binfmt_mounted_and_writable_warn(); if (r <= 0) return r; /* Flush out all rules */ r = write_string_file("/proc/sys/fs/binfmt_misc/status", "-1", WRITE_STRING_FILE_DISABLE_BUFFER); if (r < 0) log_warning_errno(r, "Failed to flush binfmt_misc rules, ignoring: %m"); else log_debug("Flushed all binfmt_misc rules."); STRV_FOREACH(f, files) RET_GATHER(r, apply_file(*f, true)); } return r; } DEFINE_MAIN_FUNCTION(run);