diff options
Diffstat (limited to 'src/cryptsetup/cryptsetup-generator.c')
| -rw-r--r-- | src/cryptsetup/cryptsetup-generator.c | 468 |
1 files changed, 468 insertions, 0 deletions
diff --git a/src/cryptsetup/cryptsetup-generator.c b/src/cryptsetup/cryptsetup-generator.c new file mode 100644 index 0000000000..81b770890a --- /dev/null +++ b/src/cryptsetup/cryptsetup-generator.c @@ -0,0 +1,468 @@ +/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ + +/*** + This file is part of systemd. + + Copyright 2010 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <string.h> +#include <errno.h> +#include <unistd.h> + +#include "log.h" +#include "util.h" +#include "unit-name.h" +#include "mkdir.h" +#include "virt.h" +#include "strv.h" +#include "fileio.h" + +static const char *arg_dest = "/tmp"; +static bool arg_enabled = true; +static bool arg_read_crypttab = true; + +static bool has_option(const char *haystack, const char *needle) { + const char *f = haystack; + size_t l; + + assert(needle); + + if (!haystack) + return false; + + l = strlen(needle); + + while ((f = strstr(f, needle))) { + + if (f > haystack && f[-1] != ',') { + f++; + continue; + } + + if (f[l] != 0 && f[l] != ',') { + f++; + continue; + } + + return true; + } + + return false; +} + +static int create_disk( + const char *name, + const char *device, + const char *password, + const char *options) { + + _cleanup_free_ char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL, *e = NULL; + _cleanup_fclose_ FILE *f = NULL; + bool noauto, nofail; + + assert(name); + assert(device); + + noauto = has_option(options, "noauto"); + nofail = has_option(options, "nofail"); + + n = unit_name_from_path_instance("systemd-cryptsetup", name, ".service"); + if (!n) + return log_oom(); + + p = strjoin(arg_dest, "/", n, NULL); + if (!p) + return log_oom(); + + u = fstab_node_to_udev_node(device); + if (!u) + return log_oom(); + + d = unit_name_from_path(u, ".device"); + if (!d) + return log_oom(); + + f = fopen(p, "wxe"); + if (!f) { + log_error("Failed to create unit file %s: %m", p); + return -errno; + } + + fputs( + "# Automatically generated by systemd-cryptsetup-generator\n\n" + "[Unit]\n" + "Description=Cryptography Setup for %I\n" + "Documentation=man:systemd-cryptsetup@.service(8) man:crypttab(5)\n" + "SourcePath=/etc/crypttab\n" + "Conflicts=umount.target\n" + "DefaultDependencies=no\n" + "BindsTo=dev-mapper-%i.device\n" + "After=systemd-readahead-collect.service systemd-readahead-replay.service\n", + f); + + if (!nofail) + fprintf(f, + "Before=cryptsetup.target\n"); + + if (password) { + if (streq(password, "/dev/urandom") || + streq(password, "/dev/random") || + streq(password, "/dev/hw_random")) + fputs("After=systemd-random-seed-load.service\n", f); + else if (!streq(password, "-") && + !streq(password, "none")) + fprintf(f, + "RequiresMountsFor=%s\n", + password); + } + + if (is_device_path(u)) + fprintf(f, + "BindsTo=%s\n" + "After=%s\n" + "Before=umount.target\n", + d, d); + else + fprintf(f, + "RequiresMountsFor=%s\n", + u); + + fprintf(f, + "\n[Service]\n" + "Type=oneshot\n" + "RemainAfterExit=yes\n" + "TimeoutSec=0\n" /* the binary handles timeouts anyway */ + "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " attach '%s' '%s' '%s' '%s'\n" + "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " detach '%s'\n", + name, u, strempty(password), strempty(options), + name); + + if (has_option(options, "tmp")) + fprintf(f, + "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n", + name); + + if (has_option(options, "swap")) + fprintf(f, + "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n", + name); + + fflush(f); + + if (ferror(f)) { + log_error("Failed to write file %s: %m", p); + return -errno; + } + + if (asprintf(&from, "../%s", n) < 0) + return log_oom(); + + if (!noauto) { + + to = strjoin(arg_dest, "/", d, ".wants/", n, NULL); + if (!to) + return log_oom(); + + mkdir_parents_label(to, 0755); + if (symlink(from, to) < 0) { + log_error("Failed to create symlink %s: %m", to); + return -errno; + } + + free(to); + if (!nofail) + to = strjoin(arg_dest, "/cryptsetup.target.requires/", n, NULL); + else + to = strjoin(arg_dest, "/cryptsetup.target.wants/", n, NULL); + if (!to) + return log_oom(); + + mkdir_parents_label(to, 0755); + if (symlink(from, to) < 0) { + log_error("Failed to create symlink %s: %m", to); + return -errno; + } + } + + e = unit_name_escape(name); + if (!e) + return log_oom(); + + free(to); + to = strjoin(arg_dest, "/dev-mapper-", e, ".device.requires/", n, NULL); + if (!to) + return log_oom(); + + mkdir_parents_label(to, 0755); + if (symlink(from, to) < 0) { + log_error("Failed to create symlink %s: %m", to); + return -errno; + } + + if (!noauto && !nofail) { + int r; + free(p); + p = strjoin(arg_dest, "/dev-mapper-", e, ".device.d/50-job-timeout-sec-0.conf", NULL); + if (!p) + return log_oom(); + + mkdir_parents_label(p, 0755); + + r = write_string_file(p, + "# Automatically generated by systemd-cryptsetup-generator\n\n" + "[Unit]\n" + "JobTimeoutSec=0\n"); /* the binary handles timeouts anyway */ + if (r) + return r; + } + + return 0; +} + +static int parse_proc_cmdline(char ***arg_proc_cmdline_disks, char **arg_proc_cmdline_keyfile) { + _cleanup_free_ char *line = NULL; + char *w = NULL, *state = NULL; + int r; + size_t l; + + if (detect_container(NULL) > 0) + return 0; + + r = read_one_line_file("/proc/cmdline", &line); + if (r < 0) { + log_warning("Failed to read /proc/cmdline, ignoring: %s", strerror(-r)); + return 0; + } + + FOREACH_WORD_QUOTED(w, l, line, state) { + _cleanup_free_ char *word = NULL; + + word = strndup(w, l); + if (!word) + return log_oom(); + + if (startswith(word, "luks=")) { + r = parse_boolean(word + 5); + if (r < 0) + log_warning("Failed to parse luks switch %s. Ignoring.", word + 5); + else + arg_enabled = r; + + } else if (startswith(word, "rd.luks=")) { + + if (in_initrd()) { + r = parse_boolean(word + 8); + if (r < 0) + log_warning("Failed to parse luks switch %s. Ignoring.", word + 8); + else + arg_enabled = r; + } + + } else if (startswith(word, "luks.crypttab=")) { + r = parse_boolean(word + 14); + if (r < 0) + log_warning("Failed to parse luks crypttab switch %s. Ignoring.", word + 14); + else + arg_read_crypttab = r; + + } else if (startswith(word, "rd.luks.crypttab=")) { + + if (in_initrd()) { + r = parse_boolean(word + 17); + if (r < 0) + log_warning("Failed to parse luks crypttab switch %s. Ignoring.", word + 17); + else + arg_read_crypttab = r; + } + + } else if (startswith(word, "luks.uuid=")) { + if (strv_extend(arg_proc_cmdline_disks, word + 10) < 0) + return log_oom(); + + } else if (startswith(word, "rd.luks.uuid=")) { + + if (in_initrd()) { + if (strv_extend(arg_proc_cmdline_disks, word + 13) < 0) + return log_oom(); + } + + } else if (startswith(word, "luks.key=")) { + *arg_proc_cmdline_keyfile = strdup(word + 9); + if (!*arg_proc_cmdline_keyfile) + return log_oom(); + + } else if (startswith(word, "rd.luks.key=")) { + + if (in_initrd()) { + if (*arg_proc_cmdline_keyfile) + free(*arg_proc_cmdline_keyfile); + *arg_proc_cmdline_keyfile = strdup(word + 12); + if (!*arg_proc_cmdline_keyfile) + return log_oom(); + } + + } else if (startswith(word, "luks.") || + (in_initrd() && startswith(word, "rd.luks."))) { + + log_warning("Unknown kernel switch %s. Ignoring.", word); + } + } + + strv_uniq(*arg_proc_cmdline_disks); + + return 0; +} + +int main(int argc, char *argv[]) { + _cleanup_strv_free_ char **arg_proc_cmdline_disks_done = NULL; + _cleanup_strv_free_ char **arg_proc_cmdline_disks = NULL; + _cleanup_free_ char *arg_proc_cmdline_keyfile = NULL; + _cleanup_fclose_ FILE *f = NULL; + unsigned n = 0; + int r = EXIT_SUCCESS; + char **i; + + if (argc > 1 && argc != 4) { + log_error("This program takes three or no arguments."); + return EXIT_FAILURE; + } + + if (argc > 1) + arg_dest = argv[1]; + + log_set_target(LOG_TARGET_SAFE); + log_parse_environment(); + log_open(); + + umask(0022); + + if (parse_proc_cmdline(&arg_proc_cmdline_disks, &arg_proc_cmdline_keyfile) < 0) + return EXIT_FAILURE; + + if (!arg_enabled) + return EXIT_SUCCESS; + + if (arg_read_crypttab) { + struct stat st; + + f = fopen("/etc/crypttab", "re"); + if (!f) { + if (errno == ENOENT) + r = EXIT_SUCCESS; + else { + r = EXIT_FAILURE; + log_error("Failed to open /etc/crypttab: %m"); + } + + goto next; + } + + if (fstat(fileno(f), &st) < 0) { + log_error("Failed to stat /etc/crypttab: %m"); + r = EXIT_FAILURE; + goto next; + } + + /* If we readd support for specifying passphrases + * directly in crypttabe we should upgrade the warning + * below, though possibly only if a passphrase is + * specified directly. */ + if (st.st_mode & 0005) + log_debug("/etc/crypttab is world-readable. This is usually not a good idea."); + + for (;;) { + char line[LINE_MAX], *l; + _cleanup_free_ char *name = NULL, *device = NULL, *password = NULL, *options = NULL; + int k; + + if (!fgets(line, sizeof(line), f)) + break; + + n++; + + l = strstrip(line); + if (*l == '#' || *l == 0) + continue; + + k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options); + if (k < 2 || k > 4) { + log_error("Failed to parse /etc/crypttab:%u, ignoring.", n); + r = EXIT_FAILURE; + continue; + } + + if (arg_proc_cmdline_disks) { + /* + If luks UUIDs are specified on the kernel command line, use them as a filter + for /etc/crypttab and only generate units for those. + */ + STRV_FOREACH(i, arg_proc_cmdline_disks) { + _cleanup_free_ char *proc_device = NULL, *proc_name = NULL; + const char *p = *i; + + if (startswith(p, "luks-")) + p += 5; + + proc_name = strappend("luks-", p); + proc_device = strappend("UUID=", p); + + if (!proc_name || !proc_device) + return log_oom(); + + if (streq(proc_device, device) || streq(proc_name, name)) { + if (create_disk(name, device, password, options) < 0) + r = EXIT_FAILURE; + + if (strv_extend(&arg_proc_cmdline_disks_done, p) < 0) + return log_oom(); + } + } + } else { + if (create_disk(name, device, password, options) < 0) + r = EXIT_FAILURE; + } + } + } + +next: + STRV_FOREACH(i, arg_proc_cmdline_disks) { + /* + Generate units for those UUIDs, which were specified + on the kernel command line and not yet written. + */ + + _cleanup_free_ char *name = NULL, *device = NULL; + const char *p = *i; + + if (startswith(p, "luks-")) + p += 5; + + if (strv_contains(arg_proc_cmdline_disks_done, p)) + continue; + + name = strappend("luks-", p); + device = strappend("UUID=", p); + + if (!name || !device) + return log_oom(); + + if (create_disk(name, device, arg_proc_cmdline_keyfile, "timeout=0") < 0) + r = EXIT_FAILURE; + } + + return r; +} |