Adding upstream version 241.upstream/241upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 229 insertions, 0 deletions

diff --git a/src/veritysetup/veritysetup-generator.c b/src/veritysetup/veritysetup-generator.c
new file mode 100644
index 0000000..65a4e7b
--- /dev/null
+++ b/src/veritysetup/veritysetup-generator.c
@@ -0,0 +1,229 @@
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include <errno.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "fstab-util.h"
+#include "generator.h"
+#include "hexdecoct.h"
+#include "id128-util.h"
+#include "main-func.h"
+#include "mkdir.h"
+#include "parse-util.h"
+#include "proc-cmdline.h"
+#include "specifier.h"
+#include "string-util.h"
+#include "unit-name.h"
+
+#define SYSTEMD_VERITYSETUP_SERVICE "systemd-veritysetup@root.service"
+
+static const char *arg_dest = NULL;
+static bool arg_enabled = true;
+static char *arg_root_hash = NULL;
+static char *arg_data_what = NULL;
+static char *arg_hash_what = NULL;
+
+STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_data_what, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_hash_what, freep);
+
+static int create_device(void) {
+        _cleanup_free_ char *u = NULL, *v = NULL, *d = NULL, *e = NULL, *u_escaped = NULL, *v_escaped = NULL, *root_hash_escaped = NULL;
+        _cleanup_fclose_ FILE *f = NULL;
+        const char *to;
+        int r;
+
+        /* If all three pieces of information are missing, then verity is turned off */
+        if (!arg_root_hash && !arg_data_what && !arg_hash_what)
+                return 0;
+
+        /* if one of them is missing however, the data is simply incomplete and this is an error */
+        if (!arg_root_hash)
+                log_error("Verity information incomplete, root hash unspecified.");
+        if (!arg_data_what)
+                log_error("Verity information incomplete, root data device unspecified.");
+        if (!arg_hash_what)
+                log_error("Verity information incomplete, root hash device unspecified.");
+
+        if (!arg_root_hash || !arg_data_what || !arg_hash_what)
+                return -EINVAL;
+
+        log_debug("Using root verity data device %s,\n"
+                  "                  hash device %s,\n"
+                  "                and root hash %s.", arg_data_what, arg_hash_what, arg_root_hash);
+
+        u = fstab_node_to_udev_node(arg_data_what);
+        if (!u)
+                return log_oom();
+        v = fstab_node_to_udev_node(arg_hash_what);
+        if (!v)
+                return log_oom();
+
+        u_escaped = specifier_escape(u);
+        if (!u_escaped)
+                return log_oom();
+        v_escaped = specifier_escape(v);
+        if (!v_escaped)
+                return log_oom();
+
+        r = unit_name_from_path(u, ".device", &d);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+        r = unit_name_from_path(v, ".device", &e);
+        if (r < 0)
+                return log_error_errno(r, "Failed to generate unit name: %m");
+
+        root_hash_escaped = specifier_escape(arg_root_hash);
+        if (!root_hash_escaped)
+                return log_oom();
+
+        r = generator_open_unit_file(arg_dest, NULL, SYSTEMD_VERITYSETUP_SERVICE, &f);
+        if (r < 0)
+                return r;
+
+        fprintf(f,
+                "[Unit]\n"
+                "Description=Integrity Protection Setup for %%I\n"
+                "Documentation=man:systemd-veritysetup-generator(8) man:systemd-veritysetup@.service(8)\n"
+                "SourcePath=/proc/cmdline\n"
+                "DefaultDependencies=no\n"
+                "Conflicts=umount.target\n"
+                "BindsTo=%s %s\n"
+                "IgnoreOnIsolate=true\n"
+                "After=cryptsetup-pre.target %s %s\n"
+                "Before=cryptsetup.target umount.target\n"
+                "\n[Service]\n"
+                "Type=oneshot\n"
+                "RemainAfterExit=yes\n"
+                "ExecStart=" ROOTLIBEXECDIR "/systemd-veritysetup attach root '%s' '%s' '%s'\n"
+                "ExecStop=" ROOTLIBEXECDIR "/systemd-veritysetup detach root\n",
+                d, e,
+                d, e,
+                u_escaped, v_escaped, root_hash_escaped);
+
+        r = fflush_and_check(f);
+        if (r < 0)
+                return log_error_errno(r, "Failed to write file unit "SYSTEMD_VERITYSETUP_SERVICE": %m");
+
+        to = strjoina(arg_dest, "/cryptsetup.target.requires/" SYSTEMD_VERITYSETUP_SERVICE);
+
+        (void) mkdir_parents(to, 0755);
+        if (symlink("../" SYSTEMD_VERITYSETUP_SERVICE, to) < 0)
+                return log_error_errno(errno, "Failed to create symlink %s: %m", to);
+
+        return 0;
+}
+
+static int parse_proc_cmdline_item(const char *key, const char *value, void *data) {
+        int r;
+
+        if (proc_cmdline_key_streq(key, "systemd.verity")) {
+
+                r = value ? parse_boolean(value) : 1;
+                if (r < 0)
+                        log_warning("Failed to parse verity= kernel command line switch %s. Ignoring.", value);
+                else
+                        arg_enabled = r;
+
+        } else if (proc_cmdline_key_streq(key, "roothash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_root_hash, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_root_data")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_data_what, value);
+                if (r < 0)
+                        return log_oom();
+
+        } else if (proc_cmdline_key_streq(key, "systemd.verity_root_hash")) {
+
+                if (proc_cmdline_value_missing(key, value))
+                        return 0;
+
+                r = free_and_strdup(&arg_hash_what, value);
+                if (r < 0)
+                        return log_oom();
+        }
+
+        return 0;
+}
+
+static int determine_devices(void) {
+        _cleanup_free_ void *m = NULL;
+        sd_id128_t root_uuid, verity_uuid;
+        char ids[37];
+        size_t l;
+        int r;
+
+        /* Try to automatically derive the root data and hash device paths from the root hash */
+
+        if (!arg_root_hash)
+                return 0;
+
+        if (arg_data_what && arg_hash_what)
+                return 0;
+
+        r = unhexmem(arg_root_hash, strlen(arg_root_hash), &m, &l);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse root hash: %s", arg_root_hash);
+        if (l < sizeof(sd_id128_t)) {
+                log_debug("Root hash is shorter than 128 bits (32 characters), ignoring for discovering verity partition.");
+                return 0;
+        }
+
+        if (!arg_data_what) {
+                memcpy(&root_uuid, m, sizeof(root_uuid));
+
+                arg_data_what = strjoin("/dev/disk/by-partuuid/", id128_to_uuid_string(root_uuid, ids));
+                if (!arg_data_what)
+                        return log_oom();
+        }
+
+        if (!arg_hash_what) {
+                memcpy(&verity_uuid, (uint8_t*) m + l - sizeof(verity_uuid), sizeof(verity_uuid));
+
+                arg_hash_what = strjoin("/dev/disk/by-partuuid/", id128_to_uuid_string(verity_uuid, ids));
+                if (!arg_hash_what)
+                        return log_oom();
+        }
+
+        return 1;
+}
+
+static int run(const char *dest, const char *dest_early, const char *dest_late) {
+        int r;
+
+        assert_se(arg_dest = dest);
+
+        r = proc_cmdline_parse(parse_proc_cmdline_item, NULL, PROC_CMDLINE_STRIP_RD_PREFIX);
+        if (r < 0)
+                return log_warning_errno(r, "Failed to parse kernel command line: %m");
+
+        /* For now we only support the root device on verity. Later on we might want to add support for /etc/veritytab
+         * or similar to define additional mappings */
+
+        if (!arg_enabled)
+                return 0;
+
+        r = determine_devices();
+        if (r < 0)
+                return r;
+
+        return create_device();
+}
+
+DEFINE_MAIN_GENERATOR_FUNCTION(run);