cryptsetup: minimal cryptsetup unit generator

1 files changed, 239 insertions, 0 deletions

diff --git a/src/cryptsetup-generator.c b/src/cryptsetup-generator.c
new file mode 100644
index 0000000000..792c1f52d7
--- /dev/null
+++ b/src/cryptsetup-generator.c
@@ -0,0 +1,239 @@
+/*-*- 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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU 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"
+
+const char *arg_dest = "/tmp";
+
+static bool has_option(const char *haystack, const char *needle) {
+        const char *f = haystack;
+        size_t l;
+
+        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) {
+
+        char *p = NULL, *n = NULL, *d = NULL, *u = NULL, *from = NULL, *to = NULL;
+        int r;
+        FILE *f = NULL;
+
+        assert(name);
+        assert(device);
+
+        if (!(n = unit_name_build_escape("cryptsetup", name, ".service"))) {
+                r = -ENOMEM;
+                log_error("Failed to allocate unit name.");
+                goto fail;
+        }
+
+        if (asprintf(&p, "%s/%s", arg_dest, n) < 0) {
+                r = -ENOMEM;
+                log_error("Failed to allocate unit file name.");
+                goto fail;
+        }
+
+        if (!(u = fstab_node_to_udev_node(device))) {
+                r = -ENOMEM;
+                log_error("Failed to allocate device node.");
+                goto fail;
+        }
+
+        if (!(d = unit_name_from_path(u, ".device"))) {
+                r = -ENOMEM;
+                log_error("Failed to allocate device name.");
+                goto fail;
+        }
+
+        if (!(f = fopen(p, "wxe"))) {
+                r = -errno;
+                log_error("Failed to create unit file: %m");
+                goto fail;
+        }
+
+        fprintf(f,
+                "[Unit]\n"
+                "Description=Cryptography Setup for %%f\n"
+                "DefaultDependencies=no\n"
+                "BindTo=%s\n"
+                "After=systemd-readahead-collect.service systemd-readahead-replay.service %s\n"
+                "Before=dev-mapper-%%f.device shutdown.target\n",
+                d, d);
+
+        if (password && (streq(password, "/dev/urandom") ||
+                         streq(password, "/dev/random") ||
+                         streq(password, "/dev/hw_random")))
+                fprintf(f,
+                        "After=systemd-random-seed-load.service\n");
+
+        fprintf(f,
+                "\n[Service]\n"
+                "Type=oneshot\n"
+                "RemainAfterExit=yes\n"
+                "ExecStart=" SYSTEMD_CRYPTSETUP_PATH " %s '%s' '%s' '%s' '%s'\n"
+                "ExecStop=" SYSTEMD_CRYPTSETUP_PATH " remove '%s'\n",
+                options && has_option(options, "swap") ? "format" : "create",
+                name, u, strempty(password), strempty(options),
+                name);
+
+        if (options && has_option(options, "tmp"))
+                fprintf(f,
+                        "ExecStartPost=/sbin/mke2fs '%s'",
+                        u);
+
+        if (options && has_option(options, "swap"))
+                fprintf(f,
+                        "ExecStartPost=/sbin/mkswap '%s'",
+                        u);
+
+        fflush(f);
+
+        if (ferror(f)) {
+                r = -errno;
+                log_error("Failed to write file: %m");
+                goto fail;
+        }
+
+        if (!options || !has_option(options, "noauto")) {
+
+                if (asprintf(&to, "%s/%s.wants/%s", arg_dest, d, n) < 0) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                if (asprintf(&from, "../%s", n) < 0) {
+                        r = -ENOMEM;
+                        goto fail;
+                }
+
+                mkdir_parents(to, 0755);
+
+                if (symlink(from, to) < 0) {
+                        log_error("Failed to create symlink '%s' to '%s': %m", from, to);
+                        r = -errno;
+                        goto fail;
+                }
+        }
+
+        r = 0;
+
+fail:
+        free(p);
+        free(n);
+        free(d);
+
+        free(from);
+        free(to);
+
+        if (f)
+                fclose(f);
+
+        return r;
+}
+
+int main(int argc, char *argv[]) {
+        FILE *f;
+        int r = EXIT_SUCCESS;
+        unsigned n = 0;
+
+        if (argc > 2) {
+                log_error("This program takes one or no arguments.");
+                return EXIT_FAILURE;
+        }
+
+        arg_dest = argv[1];
+
+        log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
+        log_parse_environment();
+        log_open();
+
+        if (!(f = fopen("/etc/crypttab", "re"))) {
+
+                if (errno == ENOENT)
+                        r = EXIT_SUCCESS;
+                else {
+                        r = EXIT_FAILURE;
+                        log_error("Failed to open /etc/crypttab: %m");
+                }
+
+                goto finish;
+        }
+
+        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++;
+
+                l = strstrip(line);
+                if (*l == '#' || *l == 0)
+                        continue;
+
+                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 (create_disk(name, device, password, options) < 0)
+                        r = EXIT_FAILURE;
+
+        next:
+                free(name);
+                free(device);
+                free(password);
+                free(options);
+        }
+
+finish:
+        return r;
+}