Hi Sughosh,
On Thu, Jan 20, 2022 at 12:25:48AM +0530, Sughosh Ganu wrote:
> The Dependable Boot specification describes the structure of the
> firmware accept and revert capsules. These are empty capsules which
> are used for signalling the acceptance or rejection of the updated
> firmware by the OS. Add support for generating these empty capsules.
>
> Signed-off-by: Sughosh Ganu <sughosh.g...@linaro.org>
> ---
>
> Changes since V2:
> * New patch for generating empty capsules
>
> tools/eficapsule.h | 8 ++++
> tools/mkeficapsule.c | 102 ++++++++++++++++++++++++++++++++++++++-----
> 2 files changed, 100 insertions(+), 10 deletions(-)
>
> diff --git a/tools/eficapsule.h b/tools/eficapsule.h
> index 8c1560bb06..6001952bdc 100644
> --- a/tools/eficapsule.h
> +++ b/tools/eficapsule.h
> @@ -50,6 +50,14 @@ typedef struct {
> EFI_GUID(0x4aafd29d, 0x68df, 0x49ee, 0x8a, 0xa9, \
> 0x34, 0x7d, 0x37, 0x56, 0x65, 0xa7)
>
> +#define FW_ACCEPT_OS_GUID \
> + EFI_GUID(0x0c996046, 0xbcc0, 0x4d04, 0x85, 0xec, \
> + 0xe1, 0xfc, 0xed, 0xf1, 0xc6, 0xf8)
> +
> +#define FW_REVERT_OS_GUID \
> + EFI_GUID(0xacd58b4b, 0xc0e8, 0x475f, 0x99, 0xb5, \
> + 0x6b, 0x3f, 0x7e, 0x07, 0xaa, 0xf0)
> +
> /* flags */
> #define CAPSULE_FLAGS_PERSIST_ACROSS_RESET 0x00010000
>
> diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c
> index 161affdd15..643da3849d 100644
> --- a/tools/mkeficapsule.c
> +++ b/tools/mkeficapsule.c
> @@ -29,6 +29,7 @@
> #include "eficapsule.h"
>
> static const char *tool_name = "mkeficapsule";
> +static unsigned char empty_capsule;
>
> efi_guid_t efi_guid_fm_capsule = EFI_FIRMWARE_MANAGEMENT_CAPSULE_ID_GUID;
> efi_guid_t efi_guid_image_type_uboot_fit =
> @@ -38,9 +39,9 @@ efi_guid_t efi_guid_image_type_uboot_raw =
> efi_guid_t efi_guid_cert_type_pkcs7 = EFI_CERT_TYPE_PKCS7_GUID;
>
> #ifdef CONFIG_TOOLS_LIBCRYPTO
> -static const char *opts_short = "frg:i:I:v:p:c:m:dh";
> +static const char *opts_short = "frg:i:I:v:p:c:m:dhAR";
> #else
> -static const char *opts_short = "frg:i:I:v:h";
> +static const char *opts_short = "frg:i:I:v:hAR";
> #endif
>
> static struct option options[] = {
> @@ -55,15 +56,23 @@ static struct option options[] = {
> {"monotonic-count", required_argument, NULL, 'm'},
> {"dump-sig", no_argument, NULL, 'd'},
> #endif
> + {"fw-accept", no_argument, NULL, 'A'},
> + {"fw-revert", no_argument, NULL, 'R'},
> {"help", no_argument, NULL, 'h'},
> {NULL, 0, NULL, 0},
> };
>
> static void print_usage(void)
> {
> - fprintf(stderr, "Usage: %s [options] <image blob> <output file>\n"
> - "Options:\n"
> + if (empty_capsule) {
> + fprintf(stderr, "Usage: %s [options] <output file>\n",
> + tool_name);
> + } else {
> + fprintf(stderr, "Usage: %s [options] <image blob> <output
> file>\n",
> + tool_name);
> + }
>
> + fprintf(stderr, "Options:\n"
> "\t-f, --fit FIT image type\n"
> "\t-r, --raw raw image type\n"
> "\t-g, --guid <guid string> guid for image blob type\n"
> @@ -75,8 +84,9 @@ static void print_usage(void)
> "\t-m, --monotonic-count <count> monotonic count\n"
> "\t-d, --dump_sig dump signature (*.p7)\n"
> #endif
> - "\t-h, --help print a help message\n",
> - tool_name);
> + "\t-A, --fw-accept firmware accept capsule\n"
> + "\t-R, --fw-revert firmware revert capsule\n"
> + "\t-h, --help print a help message\n");
> }
>
> /**
> @@ -598,6 +608,59 @@ void convert_uuid_to_guid(unsigned char *buf)
> buf[7] = c;
> }
>
> +static int create_empty_capsule(char *path, efi_guid_t *guid, bool fw_accept)
> +{
> + struct efi_capsule_header header;
> + FILE *f;
> + int ret;
> + efi_guid_t fw_accept_guid = FW_ACCEPT_OS_GUID;
> + efi_guid_t fw_revert_guid = FW_REVERT_OS_GUID;
> + efi_guid_t payload, capsule_guid;
> +
> + f = NULL;
> + ret = -1;
Can we init those at their declaration?
> +
> + f = fopen(path, "w");
> + if (!f) {
> + printf("cannot open %s\n", path);
> + goto err;
> + }
> +
> + if (fw_accept)
> + capsule_guid = fw_accept_guid;
> + else
> + capsule_guid = fw_revert_guid;
ternary operator would look better here.
> +
> + memcpy(&header.capsule_guid, &capsule_guid, sizeof(efi_guid_t));
> + header.header_size = sizeof(header);
> + header.flags = 0;
Is it the flags only you need? Or maybe memset the entire headeri to 0?
> +
> + if (fw_accept) {
> + header.capsule_image_size = sizeof(header) + sizeof(efi_guid_t);
> + } else {
> + header.capsule_image_size = sizeof(header);
> + }
ternary again?
> +
> + if (write_capsule_file(f, &header, sizeof(header),
> + "Capsule header"))
> + goto err;
> +
> + if (fw_accept) {
> + memcpy(&payload, guid, sizeof(efi_guid_t));
> + if (write_capsule_file(f, &payload, sizeof(payload),
> + "FW Accept Capsule Payload"))
> + goto err;
> + }
> +
> + ret = 0;
> +
> +err:
> + if (f)
> + fclose(f);
> +
> + return ret;
> +}
> +
> /**
> * main - main entry function of mkeficapsule
> * @argc: Number of arguments
> @@ -616,6 +679,7 @@ int main(int argc, char **argv)
> unsigned char uuid_buf[16];
> unsigned long index, instance;
> uint64_t mcount;
> + unsigned char accept_fw_capsule, revert_fw_capsule;
> char *privkey_file, *cert_file;
> int c, idx;
>
> @@ -625,6 +689,8 @@ int main(int argc, char **argv)
> mcount = 0;
> privkey_file = NULL;
> cert_file = NULL;
> + accept_fw_capsule = 0;
> + revert_fw_capsule = 0;
> dump_sig = 0;
> for (;;) {
> c = getopt_long(argc, argv, opts_short, options, &idx);
> @@ -691,22 +757,38 @@ int main(int argc, char **argv)
> dump_sig = 1;
> break;
> #endif /* CONFIG_TOOLS_LIBCRYPTO */
> + case 'A':
> + accept_fw_capsule = 1;
> + break;
> + case 'R':
> + revert_fw_capsule = 1;
> + break;
> case 'h':
> print_usage();
> exit(EXIT_SUCCESS);
> }
> }
>
> + empty_capsule = (accept_fw_capsule || revert_fw_capsule);
Why do we need 3 variables here?
Would it be better to have an enum and just use a single variable like
"is_accept_capsule"?
> +
> /* check necessary parameters */
> - if ((argc != optind + 2) || !guid ||
> - ((privkey_file && !cert_file) ||
> + if ((!empty_capsule && argc != optind + 2) ||
> + (empty_capsule && argc != optind + 1) ||
> + (!revert_fw_capsule && !guid) || ((privkey_file && !cert_file) ||
> (!privkey_file && cert_file))) {
> print_usage();
> exit(EXIT_FAILURE);
> }
>
> - if (create_fwbin(argv[argc - 1], argv[argc - 2], guid, index, instance,
> - mcount, privkey_file, cert_file) < 0) {
> + if (empty_capsule) {
> + if (create_empty_capsule(argv[argc - 1], guid,
> + accept_fw_capsule ? 1 : 0) < 0) {
> + printf("Creating empty capsule failed\n");
> + exit(EXIT_FAILURE);
> + }
> + } else if (create_fwbin(argv[argc - 1], argv[argc - 2], guid,
> + index, instance, mcount, privkey_file,
> + cert_file) < 0) {
> fprintf(stderr, "Creating firmware capsule failed\n");
> exit(EXIT_FAILURE);
> }
> --
> 2.17.1
>
Thanks
/Ilias
