chiark / gitweb /
Support negated fstab options
[elogind.git] / src / cryptsetup / cryptsetup-generator.c
index 4d10373a79b49c64818231087aef233eb3a8c63b..27b2360d240fffddd5c604a44b2f66c71657ff2e 100644 (file)
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 ***/
 
-#include <string.h>
 #include <errno.h>
+#include <string.h>
 #include <unistd.h>
 
+#include "dropin.h"
+#include "fileio.h"
+#include "generator.h"
+#include "hashmap.h"
 #include "log.h"
-#include "util.h"
-#include "unit-name.h"
 #include "mkdir.h"
+#include "path-util.h"
+#include "fstab-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "util.h"
 
-const char *arg_dest = "/tmp";
-
-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;
-}
+typedef struct crypto_device {
+        char *uuid;
+        char *keyfile;
+        char *name;
+        char *options;
+        bool create;
+} crypto_device;
+
+static const char *arg_dest = "/tmp";
+static bool arg_enabled = true;
+static bool arg_read_crypttab = true;
+static bool arg_whitelist = false;
+static Hashmap *arg_disks = NULL;
+static char *arg_default_options = NULL;
+static char *arg_default_keyfile = NULL;
 
 static int create_disk(
                 const char *name,
@@ -65,69 +57,107 @@ static int create_disk(
                 const char *password,
                 const char *options) {
 
-        char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL, *e = NULL;
+        _cleanup_free_ char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *to = NULL, *e = NULL,
+                *filtered = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        bool noauto, nofail, tmp, swap;
+        char *from;
         int r;
-        FILE *f = NULL;
-        bool noauto, nofail;
 
         assert(name);
         assert(device);
 
-        noauto = has_option(options, "noauto");
-        nofail = has_option(options, "nofail");
+        noauto = fstab_test_yes_no_option(options, "noauto\0" "auto\0");
+        nofail = fstab_test_yes_no_option(options, "nofail\0" "fail\0");
+        tmp = fstab_test_option(options, "tmp\0");
+        swap = fstab_test_option(options, "swap\0");
 
-        if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
-                r = -ENOMEM;
-                log_error("Failed to allocate unit name.");
-                goto fail;
+        if (tmp && swap) {
+                log_error("Device '%s' cannot be both 'tmp' and 'swap'. Ignoring.", name);
+                return -EINVAL;
         }
 
-        if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
-                r = -ENOMEM;
-                log_error("Failed to allocate unit file name.");
-                goto fail;
-        }
+        e = unit_name_escape(name);
+        if (!e)
+                return log_oom();
 
-        if (!(u = fstab_node_to_udev_node(device))) {
-                r = -ENOMEM;
-                log_error("Failed to allocate device node.");
-                goto fail;
-        }
+        n = unit_name_build("systemd-cryptsetup", e, ".service");
+        if (!n)
+                return log_oom();
 
-        if (!(d = unit_name_from_path(u, ".device"))) {
-                r = -ENOMEM;
-                log_error("Failed to allocate device name.");
-                goto fail;
-        }
+        p = strjoin(arg_dest, "/", n, NULL);
+        if (!p)
+                return log_oom();
 
-        if (!(f = fopen(p, "wxe"))) {
-                r = -errno;
-                log_error("Failed to create unit file: %m");
-                goto fail;
-        }
+        u = fstab_node_to_udev_node(device);
+        if (!u)
+                return log_oom();
 
-        fprintf(f,
+        d = unit_name_from_path(u, ".device");
+        if (!d)
+                return log_oom();
+
+        f = fopen(p, "wxe");
+        if (!f)
+                return log_error_errno(errno, "Failed to create unit file %s: %m", p);
+
+        fputs(
+                "# Automatically generated by systemd-cryptsetup-generator\n\n"
                 "[Unit]\n"
-                "Description=Cryptography Setup for %%I\n"
-                "Conflicts=umount.target\n"
+                "Description=Cryptography Setup for %I\n"
+                "Documentation=man:crypttab(5) man:systemd-cryptsetup-generator(8) man:systemd-cryptsetup@.service(8)\n"
+                "SourcePath=/etc/crypttab\n"
                 "DefaultDependencies=no\n"
-                "BindTo=%s dev-mapper-%%i.device\n"
-                "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
-                "Before=umount.target\n",
-                d, d);
+                "Conflicts=umount.target\n"
+                "BindsTo=dev-mapper-%i.device\n"
+                "IgnoreOnIsolate=true\n"
+                "After=cryptsetup-pre.target\n",
+                f);
 
         if (!nofail)
                 fprintf(f,
                         "Before=cryptsetup.target\n");
 
-        if (password && (streq(password, "/dev/urandom") ||
-                         streq(password, "/dev/random") ||
-                         streq(password, "/dev/hw_random")))
+        if (password) {
+                if (STR_IN_SET(password, "/dev/urandom", "/dev/random", "/dev/hw_random"))
+                        fputs("After=systemd-random-seed.service\n", f);
+                else if (!streq(password, "-") && !streq(password, "none")) {
+                        _cleanup_free_ char *uu;
+
+                        uu = fstab_node_to_udev_node(password);
+                        if (!uu)
+                                return log_oom();
+
+                        if (!path_equal(uu, "/dev/null")) {
+
+                                if (is_device_path(uu)) {
+                                        _cleanup_free_ char *dd;
+
+                                        dd = unit_name_from_path(uu, ".device");
+                                        if (!dd)
+                                                return log_oom();
+
+                                        fprintf(f, "After=%1$s\nRequires=%1$s\n", dd);
+                                } else
+                                        fprintf(f, "RequiresMountsFor=%s\n", password);
+                        }
+                }
+        }
+
+        if (is_device_path(u))
                 fprintf(f,
-                        "After=systemd-random-seed-load.service\n");
+                        "BindsTo=%s\n"
+                        "After=%s\n"
+                        "Before=umount.target\n",
+                        d, d);
         else
                 fprintf(f,
-                        "Before=local-fs.target\n");
+                        "RequiresMountsFor=%s\n",
+                        u);
+
+        r = generator_write_timeouts(arg_dest, device, name, options, &filtered);
+        if (r < 0)
+                return r;
 
         fprintf(f,
                 "\n[Service]\n"
@@ -136,164 +166,350 @@ static int create_disk(
                 "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, u, strempty(password), strempty(filtered),
                 name);
 
-        if (has_option(options, "tmp"))
+        if (tmp)
                 fprintf(f,
                         "ExecStartPost=/sbin/mke2fs '/dev/mapper/%s'\n",
                         name);
 
-        if (has_option(options, "swap"))
+        if (swap)
                 fprintf(f,
                         "ExecStartPost=/sbin/mkswap '/dev/mapper/%s'\n",
                         name);
 
         fflush(f);
+        if (ferror(f))
+                return log_error_errno(errno, "Failed to write file %s: %m", p);
+
+        from = strappenda("../", n);
+
+        if (!noauto) {
 
-        if (ferror(f)) {
-                r = -errno;
-                log_error("Failed to write file: %m");
-                goto fail;
+                to = strjoin(arg_dest, "/", d, ".wants/", n, NULL);
+                if (!to)
+                        return log_oom();
+
+                mkdir_parents_label(to, 0755);
+                if (symlink(from, to) < 0)
+                        return log_error_errno(errno, "Failed to create symlink %s: %m", to);
+
+                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)
+                        return log_error_errno(errno, "Failed to create symlink %s: %m", to);
         }
 
-        if (asprintf(&from, "../%s", n) < 0) {
-                r = -ENOMEM;
-                goto fail;
+        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)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", to);
+
+        if (!noauto && !nofail) {
+                _cleanup_free_ char *dmname;
+                dmname = strjoin("dev-mapper-", e, ".device", NULL);
+                if (!dmname)
+                        return log_oom();
+
+                r = write_drop_in(arg_dest, dmname, 90, "device-timeout",
+                                  "# Automatically generated by systemd-cryptsetup-generator \n\n"
+                                  "[Unit]\nJobTimeoutSec=0");
+                if (r < 0)
+                        return log_error_errno(r, "Failed to write device drop-in: %m");
         }
 
-        if (!noauto) {
+        return 0;
+}
 
-                if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
-                        r = -ENOMEM;
-                        goto fail;
-                }
+static void free_arg_disks(void) {
+        crypto_device *d;
+
+        while ((d = hashmap_steal_first(arg_disks))) {
+                free(d->uuid);
+                free(d->keyfile);
+                free(d->name);
+                free(d->options);
+                free(d);
+        }
+
+        hashmap_free(arg_disks);
+}
+
+static crypto_device *get_crypto_device(const char *uuid) {
+        int r;
+        crypto_device *d;
 
-                mkdir_parents(to, 0755);
+        assert(uuid);
 
-                if (symlink(from, to) < 0) {
-                        log_error("Failed to create symlink '%s' to '%s': %m", from, to);
-                        r = -errno;
-                        goto fail;
+        d = hashmap_get(arg_disks, uuid);
+        if (!d) {
+                d = new0(struct crypto_device, 1);
+                if (!d)
+                        return NULL;
+
+                d->create = false;
+                d->keyfile = d->options = d->name = NULL;
+
+                d->uuid = strdup(uuid);
+                if (!d->uuid) {
+                        free(d);
+                        return NULL;
                 }
 
-                free(to);
-                to = NULL;
+                r = hashmap_put(arg_disks, d->uuid, d);
+                if (r < 0) {
+                        free(d->uuid);
+                        free(d);
+                        return NULL;
+                }
+        }
 
-                if (!nofail)
-                        asprintf(&to, "%s/cryptsetup.target.requires/%s", arg_dest, n);
+        return d;
+}
+
+static int parse_proc_cmdline_item(const char *key, const char *value) {
+        int r;
+        crypto_device *d;
+        _cleanup_free_ char *uuid = NULL, *uuid_value = NULL;
+
+        if (STR_IN_SET(key, "luks", "rd.luks") && value) {
+
+                r = parse_boolean(value);
+                if (r < 0)
+                        log_warning("Failed to parse luks switch %s. Ignoring.", value);
                 else
-                        asprintf(&to, "%s/cryptsetup.target.wants/%s", arg_dest, n);
+                        arg_enabled = r;
 
-                if (!to) {
-                        r = -ENOMEM;
-                        goto fail;
-                }
+        } else if (STR_IN_SET(key, "luks.crypttab", "rd.luks.crypttab") && value) {
 
-                mkdir_parents(to, 0755);
+                r = parse_boolean(value);
+                if (r < 0)
+                        log_warning("Failed to parse luks crypttab switch %s. Ignoring.", value);
+                else
+                        arg_read_crypttab = r;
+
+        } else if (STR_IN_SET(key, "luks.uuid", "rd.luks.uuid") && value) {
+
+                d = get_crypto_device(startswith(value, "luks-") ? value+5 : value);
+                if (!d)
+                        return log_oom();
+
+                d->create = arg_whitelist = true;
+
+        } else if (STR_IN_SET(key, "luks.options", "rd.luks.options") && value) {
+
+                r = sscanf(value, "%m[0-9a-fA-F-]=%ms", &uuid, &uuid_value);
+                if (r == 2) {
+                        d = get_crypto_device(uuid);
+                        if (!d)
+                                return log_oom();
+
+                        free(d->options);
+                        d->options = uuid_value;
+                        uuid_value = NULL;
+                } else if (free_and_strdup(&arg_default_options, value) < 0)
+                        return log_oom();
+
+        } else if (STR_IN_SET(key, "luks.key", "rd.luks.key") && value) {
+
+                r = sscanf(value, "%m[0-9a-fA-F-]=%ms", &uuid, &uuid_value);
+                if (r == 2) {
+                        d = get_crypto_device(uuid);
+                        if (!d)
+                                return log_oom();
+
+                        free(d->keyfile);
+                        d->keyfile = uuid_value;
+                        uuid_value = NULL;
+                } else if (free_and_strdup(&arg_default_keyfile, value))
+                        return log_oom();
+
+        } else if (STR_IN_SET(key, "luks.name", "rd.luks.name") && value) {
+
+                r = sscanf(value, "%m[0-9a-fA-F-]=%ms", &uuid, &uuid_value);
+                if (r == 2) {
+                        d = get_crypto_device(uuid);
+                        if (!d)
+                                return log_oom();
+
+                        d->create = arg_whitelist = true;
+
+                        free(d->name);
+                        d->name = uuid_value;
+                        uuid_value = NULL;
+                } else
+                        log_warning("Failed to parse luks name switch %s. Ignoring.", value);
 
-                if (symlink(from, to) < 0) {
-                        log_error("Failed to create symlink '%s' to '%s': %m", from, to);
-                        r = -errno;
-                        goto fail;
-                }
         }
 
-        free(to);
-        to = NULL;
+        return 0;
+}
 
-        e = unit_name_escape(name);
-        if (asprintf(&to, "%s/dev-mapper-%s.device.requires/%s", arg_dest, e, n) < 0) {
-                r = -ENOMEM;
-                goto fail;
+static int add_crypttab_devices(void) {
+        struct stat st;
+        unsigned crypttab_line = 0;
+        _cleanup_fclose_ FILE *f = NULL;
+
+        if (!arg_read_crypttab)
+                return 0;
+
+        f = fopen("/etc/crypttab", "re");
+        if (!f) {
+                if (errno != ENOENT)
+                        log_error_errno(errno, "Failed to open /etc/crypttab: %m");
+                return 0;
+        }
+
+        if (fstat(fileno(f), &st) < 0) {
+                log_error_errno(errno, "Failed to stat /etc/crypttab: %m");
+                return 0;
         }
 
-        mkdir_parents(to, 0755);
+        /* If we readd support for specifying passphrases
+         * directly in crypttab 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.");
 
-        if (symlink(from, to) < 0) {
-                log_error("Failed to create symlink '%s' to '%s': %m", from, to);
-                r = -errno;
-                goto fail;
+        for (;;) {
+                int r, k;
+                char line[LINE_MAX], *l, *uuid;
+                crypto_device *d = NULL;
+                _cleanup_free_ char *name = NULL, *device = NULL, *keyfile = NULL, *options = NULL;
+
+                if (!fgets(line, sizeof(line), f))
+                        break;
+
+                crypttab_line++;
+
+                l = strstrip(line);
+                if (*l == '#' || *l == 0)
+                        continue;
+
+                k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &keyfile, &options);
+                if (k < 2 || k > 4) {
+                        log_error("Failed to parse /etc/crypttab:%u, ignoring.", crypttab_line);
+                        continue;
+                }
+
+                uuid = startswith(device, "UUID=");
+                if (!uuid)
+                        uuid = path_startswith(device, "/dev/disk/by-uuid/");
+                if (!uuid)
+                        uuid = startswith(name, "luks-");
+                if (uuid)
+                        d = hashmap_get(arg_disks, uuid);
+
+                if (arg_whitelist && !d) {
+                        log_info("Not creating device '%s' because it was not specified on the kernel command line.", name);
+                        continue;
+                }
+
+                r = create_disk(name, device, keyfile, (d && d->options) ? d->options : options);
+                if (r < 0)
+                        return r;
+
+                if (d)
+                        d->create = false;
         }
 
-        r = 0;
+        return 0;
+}
+
+static int add_proc_cmdline_devices(void) {
+        int r;
+        Iterator i;
+        crypto_device *d;
 
-fail:
-        free(p);
-        free(n);
-        free(d);
-        free(e);
+        HASHMAP_FOREACH(d, arg_disks, i) {
+                const char *options;
+                _cleanup_free_ char *device = NULL;
 
-        free(from);
-        free(to);
+                if (!d->create)
+                        continue;
+
+                if (!d->name) {
+                        d->name = strappend("luks-", d->uuid);
+                        if (!d->name)
+                                return log_oom();
+                }
 
-        if (f)
-                fclose(f);
+                device = strappend("UUID=", d->uuid);
+                if (!device)
+                        return log_oom();
 
-        return r;
+                if (d->options)
+                        options = d->options;
+                else if (arg_default_options)
+                        options = arg_default_options;
+                else
+                        options = "timeout=0";
+
+                r = create_disk(d->name, device, d->keyfile ?: arg_default_keyfile, options);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
 }
 
 int main(int argc, char *argv[]) {
-        FILE *f;
-        int r = EXIT_SUCCESS;
-        unsigned n = 0;
+        int r = EXIT_FAILURE;
 
-        if (argc > 2) {
-                log_error("This program takes one or no arguments.");
+        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_AUTO);
+        log_set_target(LOG_TARGET_SAFE);
         log_parse_environment();
         log_open();
 
         umask(0022);
 
-        if (!(f = fopen("/etc/crypttab", "re"))) {
+        arg_disks = hashmap_new(&string_hash_ops);
+        if (!arg_disks)
+                goto cleanup;
 
-                if (errno == ENOENT)
-                        r = EXIT_SUCCESS;
-                else {
-                        r = EXIT_FAILURE;
-                        log_error("Failed to open /etc/crypttab: %m");
-                }
-
-                goto finish;
+        r = parse_proc_cmdline(parse_proc_cmdline_item);
+        if (r < 0) {
+                log_warning_errno(r, "Failed to parse kernel command line, ignoring: %m");
+                r = EXIT_FAILURE;
         }
 
-        for (;;) {
-                char line[LINE_MAX], *l;
-                char *name = NULL, *device = NULL, *password = NULL, *options = NULL;
-                int k;
-
-                if (!(fgets(line, sizeof(line), f)))
-                        break;
-
-                n++;
+        if (!arg_enabled) {
+                r = EXIT_SUCCESS;
+                goto cleanup;
+        }
 
-                l = strstrip(line);
-                if (*l == '#' || *l == 0)
-                        continue;
+        if (add_crypttab_devices() < 0)
+                goto cleanup;
 
-                if ((k = sscanf(l, "%ms %ms %ms %ms", &name, &device, &password, &options)) < 2 || k > 4) {
-                        log_error("Failed to parse /etc/crypttab:%u, ignoring.", n);
-                        r = EXIT_FAILURE;
-                        goto next;
-                }
+        if (add_proc_cmdline_devices() < 0)
+                goto cleanup;
 
-                if (create_disk(name, device, password, options) < 0)
-                        r = EXIT_FAILURE;
+        r = EXIT_SUCCESS;
 
-        next:
-                free(name);
-                free(device);
-                free(password);
-                free(options);
-        }
+cleanup:
+        free_arg_disks();
+        free(arg_default_options);
+        free(arg_default_keyfile);
 
-finish:
         return r;
 }