On 8/12/19 12:56 PM, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@xxxxxxxxxx>
>
> get_encpolicy uses the FS_IOC_GET_ENCRYPTION_POLICY ioctl to retrieve
> the file's encryption policy, then displays it. But that only works for
> v1 encryption policies. A new ioctl, FS_IOC_GET_ENCRYPTION_POLICY_EX,
> has been introduced which is more flexible and can retrieve both v1 and
> v2 encryption policies.
...
> +static void
> +test_for_v2_policy_support(void)
> +{
> + struct fscrypt_get_policy_ex_arg arg;
> +
> + arg.policy_size = sizeof(arg.policy);
> +
> + if (ioctl(file->fd, FS_IOC_GET_ENCRYPTION_POLICY_EX, &arg) == 0 ||
> + errno == ENODATA /* file unencrypted */) {
> + printf("supported\n");
> + return;
> + }
> + if (errno == ENOTTY) {
> + printf("unsupported\n");
> + return;
> + }
> + fprintf(stderr,
> + "%s: unexpected error checking for FS_IOC_GET_ENCRYPTION_POLICY_EX support: %s\n",
Darrick also mentioned to me off-list that the io/encrypt.c code is chock full of
strings that really need to be _("translatable")
-Eric
> + file->name, strerror(errno));
> + exitcode = 1;
> +}
> +
> +static void
> +show_v1_encryption_policy(const struct fscrypt_policy_v1 *policy)
> +{
> + printf("Encryption policy for %s:\n", file->name);
> + printf("\tPolicy version: %u\n", policy->version);
> + printf("\tMaster key descriptor: %s\n",
> + keydesc2str(policy->master_key_descriptor));
> + printf("\tContents encryption mode: %u (%s)\n",
> + policy->contents_encryption_mode,
> + mode2str(policy->contents_encryption_mode));
> + printf("\tFilenames encryption mode: %u (%s)\n",
> + policy->filenames_encryption_mode,
> + mode2str(policy->filenames_encryption_mode));
> + printf("\tFlags: 0x%02x\n", policy->flags);
> +}
> +
> +static void
> +show_v2_encryption_policy(const struct fscrypt_policy_v2 *policy)
> +{
> + printf("Encryption policy for %s:\n", file->name);
> + printf("\tPolicy version: %u\n", policy->version);
> + printf("\tMaster key identifier: %s\n",
> + keyid2str(policy->master_key_identifier));
> + printf("\tContents encryption mode: %u (%s)\n",
> + policy->contents_encryption_mode,
> + mode2str(policy->contents_encryption_mode));
> + printf("\tFilenames encryption mode: %u (%s)\n",
> + policy->filenames_encryption_mode,
> + mode2str(policy->filenames_encryption_mode));
> + printf("\tFlags: 0x%02x\n", policy->flags);
> +}
> +
> static int
> get_encpolicy_f(int argc, char **argv)
> {
> - struct fscrypt_policy policy;
> + int c;
> + struct fscrypt_get_policy_ex_arg arg;
> + bool only_use_v1_ioctl = false;
> + int res;
>
> - if (ioctl(file->fd, FS_IOC_GET_ENCRYPTION_POLICY, &policy) < 0) {
> + while ((c = getopt(argc, argv, "1t")) != EOF) {
> + switch (c) {
> + case '1':
> + only_use_v1_ioctl = true;
> + break;
> + case 't':
> + test_for_v2_policy_support();
> + return 0;
> + default:
> + return command_usage(&get_encpolicy_cmd);
> + }
> + }
> + argc -= optind;
> + argv += optind;
> +
> + if (argc != 0)
> + return command_usage(&get_encpolicy_cmd);
> +
> + /* first try the new ioctl */
> + if (only_use_v1_ioctl) {
> + res = -1;
> + errno = ENOTTY;
> + } else {
> + arg.policy_size = sizeof(arg.policy);
> + res = ioctl(file->fd, FS_IOC_GET_ENCRYPTION_POLICY_EX, &arg);
> + }
> +
> + /* fall back to the old ioctl */
> + if (res != 0 && errno == ENOTTY)
> + res = ioctl(file->fd, FS_IOC_GET_ENCRYPTION_POLICY,
> + &arg.policy.v1);
> +
> + if (res != 0) {
> fprintf(stderr, "%s: failed to get encryption policy: %s\n",
> file->name, strerror(errno));
> exitcode = 1;
> return 0;
> }
>
> - printf("Encryption policy for %s:\n", file->name);
> - printf("\tPolicy version: %u\n", policy.version);
> - printf("\tMaster key descriptor: %s\n",
> - keydesc2str(policy.master_key_descriptor));
> - printf("\tContents encryption mode: %u (%s)\n",
> - policy.contents_encryption_mode,
> - mode2str(policy.contents_encryption_mode));
> - printf("\tFilenames encryption mode: %u (%s)\n",
> - policy.filenames_encryption_mode,
> - mode2str(policy.filenames_encryption_mode));
> - printf("\tFlags: 0x%02x\n", policy.flags);
> + switch (arg.policy.version) {
> + case FSCRYPT_POLICY_V1:
> + show_v1_encryption_policy(&arg.policy.v1);
> + break;
> + case FSCRYPT_POLICY_V2:
> + show_v2_encryption_policy(&arg.policy.v2);
> + break;
> + default:
> + printf("Encryption policy for %s:\n", file->name);
> + printf("\tPolicy version: %u (unknown)\n", arg.policy.version);
> + break;
> + }
> return 0;
> }
>
> @@ -351,11 +467,13 @@ encrypt_init(void)
> {
> get_encpolicy_cmd.name = "get_encpolicy";
> get_encpolicy_cmd.cfunc = get_encpolicy_f;
> + get_encpolicy_cmd.args = _("[-1] [-t]");
> get_encpolicy_cmd.argmin = 0;
> - get_encpolicy_cmd.argmax = 0;
> + get_encpolicy_cmd.argmax = -1;
> get_encpolicy_cmd.flags = CMD_NOMAP_OK | CMD_FOREIGN_OK;
> get_encpolicy_cmd.oneline =
> _("display the encryption policy of the current file");
> + get_encpolicy_cmd.help = get_encpolicy_help;
>
> set_encpolicy_cmd.name = "set_encpolicy";
> set_encpolicy_cmd.cfunc = set_encpolicy_f;
> diff --git a/man/man8/xfs_io.8 b/man/man8/xfs_io.8
> index 6e064bdd..3dd34a0c 100644
> --- a/man/man8/xfs_io.8
> +++ b/man/man8/xfs_io.8
> @@ -724,10 +724,21 @@ version of policy structure (numeric)
> .RE
> .PD
> .TP
> -.BR get_encpolicy
> +.BI "get_encpolicy [ \-1 ] [ \-t ]"
> On filesystems that support encryption, display the encryption policy of the
> current file.
> -
> +.RS 1.0i
> +.PD 0
> +.TP 0.4i
> +.BI \-1
> +Use only the old ioctl to get the encryption policy. This only works if the
> +file has a v1 encryption policy.
> +.TP
> +.BI \-t
> +Test whether v2 encryption policies are supported. Prints "supported",
> +"unsupported", or an error message.
> +.RE
> +.PD
> .TP
> .BR lsattr " [ " \-R " | " \-D " | " \-a " | " \-v " ]"
> List extended inode flags on the currently open file. If the
>
