SymbX/systemd
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity
Files
9a2a6ec4e31abe4b58b140767a82200f79c8645f
systemd/src/veritysetup/veritysetup-generator.c
T
Tony Asleson 9a2a6ec4e3 dm-verity: Remove usage of integrity 
There is a difference between dm-verity and dm-integrity.  Remove
usage of integrity from verity documentation in man pages and
target files.
2021-10-14 12:17:02 -05:00

453 lines
16 KiB
C
Raw Blame History

/* SPDX-License-Identifier: LGPL-2.1-or-later */
#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 "path-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 bool arg_read_veritytab = true;
static const char *arg_veritytab = NULL;
static char *arg_root_hash = NULL;
static char *arg_data_what = NULL;
static char *arg_hash_what = NULL;
static char *arg_options = NULL;
STATIC_DESTRUCTOR_REGISTER(arg_root_hash, freep);
STATIC_DESTRUCTOR_REGISTER(arg_data_what, freep);
STATIC_DESTRUCTOR_REGISTER(arg_hash_what, freep);
STATIC_DESTRUCTOR_REGISTER(arg_options, 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, *options_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"
" options %s,\n"
" and root hash %s.", arg_data_what, arg_hash_what, arg_options, 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");
options_escaped = specifier_escape(strempty(arg_options));
if (!options_escaped)
return log_oom();
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=Verity 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=veritysetup-pre.target systemd-udevd-kernel.socket %s %s\n"
"Before=veritysetup.target umount.target\n"
"\n[Service]\n"
"Type=oneshot\n"
"RemainAfterExit=yes\n"
"ExecStart=" ROOTLIBEXECDIR "/systemd-veritysetup attach root '%s' '%s' '%s' '%s'\n"
"ExecStop=" ROOTLIBEXECDIR "/systemd-veritysetup detach root\n",
d, e,
d, e,
u_escaped, v_escaped, root_hash_escaped, options_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, "/veritysetup.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 (streq(key, "veritytab")) {
r = value ? parse_boolean(value) : 1;
if (r < 0)
log_warning("Failed to parse veritytab= kernel command line switch %s. Ignoring.", value);
else
arg_read_veritytab = 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();
} else if (proc_cmdline_key_streq(key, "systemd.verity_root_options")) {
if (proc_cmdline_value_missing(key, value))
return 0;
r = free_and_strdup(&arg_options, 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;
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 = path_join("/dev/disk/by-partuuid", ID128_TO_UUID_STRING(root_uuid));
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 = path_join("/dev/disk/by-partuuid", ID128_TO_UUID_STRING(verity_uuid));
if (!arg_hash_what)
return log_oom();
}
return 1;
}
static int create_disk(
const char *name,
const char *data_device,
const char *hash_device,
const char *roothash,
const char *options,
const char *source) {
_cleanup_free_ char *n = NULL, *dd = NULL, *du = NULL, *hd = NULL, *hu = NULL, *e = NULL,
*du_escaped = NULL, *hu_escaped = NULL, *name_escaped = NULL;
_cleanup_fclose_ FILE *f = NULL;
const char *dmname;
bool noauto, nofail, netdev, attach_in_initrd;
int r;
assert(name);
assert(data_device);
assert(hash_device);
assert(roothash);
noauto = fstab_test_yes_no_option(options, "noauto\0" "auto\0");
nofail = fstab_test_yes_no_option(options, "nofail\0" "fail\0");
netdev = fstab_test_option(options, "_netdev\0");
attach_in_initrd = fstab_test_option(options, "x-initrd.attach\0");
name_escaped = specifier_escape(name);
if (!name_escaped)
return log_oom();
e = unit_name_escape(name);
if (!e)
return log_oom();
du = fstab_node_to_udev_node(data_device);
if (!du)
return log_oom();
hu = fstab_node_to_udev_node(hash_device);
if (!hu)
return log_oom();
r = unit_name_build("systemd-veritysetup", e, ".service", &n);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
du_escaped = specifier_escape(du);
if (!du_escaped)
return log_oom();
hu_escaped = specifier_escape(hu);
if (!hu_escaped)
return log_oom();
r = unit_name_from_path(du, ".device", &dd);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
r = unit_name_from_path(hu, ".device", &hd);
if (r < 0)
return log_error_errno(r, "Failed to generate unit name: %m");
r = generator_open_unit_file(arg_dest, NULL, n, &f);
if (r < 0)
return r;
r = generator_write_veritysetup_unit_section(f, source);
if (r < 0)
return r;
if (netdev)
fprintf(f, "After=remote-fs-pre.target\n");
/* If initrd takes care of attaching the disk then it should also detach it during shutdown. */
if (!attach_in_initrd)
fprintf(f, "Conflicts=umount.target\n");
if (!nofail)
fprintf(f,
"Before=%s\n",
netdev ? "remote-veritysetup.target" : "veritysetup.target");
if (path_startswith(du, "/dev/"))
fprintf(f,
"BindsTo=%s\n"
"After=%s\n"
"Before=umount.target\n",
dd, dd);
else
/* For loopback devices, add systemd-tmpfiles-setup-dev.service
dependency to ensure that loopback support is available in
the kernel (/dev/loop-control needs to exist) */
fprintf(f,
"RequiresMountsFor=%s\n"
"Requires=systemd-tmpfiles-setup-dev.service\n"
"After=systemd-tmpfiles-setup-dev.service\n",
du_escaped);
if (path_startswith(hu, "/dev/"))
fprintf(f,
"BindsTo=%s\n"
"After=%s\n"
"Before=umount.target\n",
hd, hd);
else
/* For loopback devices, add systemd-tmpfiles-setup-dev.service
dependency to ensure that loopback support is available in
the kernel (/dev/loop-control needs to exist) */
fprintf(f,
"RequiresMountsFor=%s\n"
"Requires=systemd-tmpfiles-setup-dev.service\n"
"After=systemd-tmpfiles-setup-dev.service\n",
hu_escaped);
r = generator_write_veritysetup_service_section(f, name, du_escaped, hu_escaped, roothash, options);
if (r < 0)
return r;
r = fflush_and_check(f);
if (r < 0)
return log_error_errno(r, "Failed to write unit file %s: %m", n);
if (!noauto) {
r = generator_add_symlink(arg_dest,
netdev ? "remote-veritysetup.target" : "veritysetup.target",
nofail ? "wants" : "requires", n);
if (r < 0)
return r;
}
dmname = strjoina("dev-mapper-", e, ".device");
return generator_add_symlink(arg_dest, dmname, "requires", n);
}
static int add_veritytab_devices(void) {
_cleanup_fclose_ FILE *f = NULL;
unsigned veritytab_line = 0;
int r;
if (!arg_read_veritytab)
return 0;
r = fopen_unlocked(arg_veritytab, "re", &f);
if (r < 0) {
if (errno != ENOENT)
log_error_errno(errno, "Failed to open %s: %m", arg_veritytab);
return 0;
}
for (;;) {
_cleanup_free_ char *line = NULL, *name = NULL, *data_device = NULL, *hash_device = NULL,
*roothash = NULL, *options = NULL;
char *l, *data_uuid, *hash_uuid;
r = read_line(f, LONG_LINE_MAX, &line);
if (r < 0)
return log_error_errno(r, "Failed to read %s: %m", arg_veritytab);
if (r == 0)
break;
veritytab_line++;
l = strstrip(line);
if (IN_SET(l[0], 0, '#'))
continue;
r = sscanf(l, "%ms %ms %ms %ms %ms", &name, &data_device, &hash_device, &roothash, &options);
if (!IN_SET(r, 4, 5)) {
log_error("Failed to parse %s:%u, ignoring.", arg_veritytab, veritytab_line);
continue;
}
data_uuid = startswith(data_device, "UUID=");
if (!data_uuid)
data_uuid = path_startswith(data_device, "/dev/disk/by-uuid/");
hash_uuid = startswith(hash_device, "UUID=");
if (!hash_uuid)
hash_uuid = path_startswith(hash_device, "/dev/disk/by-uuid/");
r = create_disk(name,
data_device,
hash_device,
roothash,
options,
arg_veritytab);
if (r < 0)
return r;
}
return 0;
}
static int run(const char *dest, const char *dest_early, const char *dest_late) {
int r;
assert_se(arg_dest = dest);
arg_veritytab = getenv("SYSTEMD_VERITYTAB") ?: "/etc/veritytab";
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");
if (!arg_enabled)
return 0;
r = add_veritytab_devices();
if (r < 0)
return r;
r = determine_devices();
if (r < 0)
return r;
return create_device();
}
DEFINE_MAIN_GENERATOR_FUNCTION(run);
Reference in New Issue View Git Blame Copy Permalink