acrn-hypervisor/hypervisor/boot/sbl/abl_seed_parse.c

/*
 * Copyright (C) 2018 Intel Corporation. All rights reserved.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

#include <types.h>
#include <errno.h>
#include <sprintf.h>
#include <vm.h>
#include <mmu.h>
#include <logmsg.h>
#include <abl_seed_parse.h>
#include <ept.h>

#define ABL_SEED_LEN 32U
struct abl_seed_info {
	uint8_t svn;
	uint8_t reserved[3];
	uint8_t seed[ABL_SEED_LEN];
};

#define ABL_SEED_LIST_MAX 4U
struct dev_sec_info {
	uint32_t size_of_this_struct;
	uint32_t version;
	uint32_t num_seeds;
	struct abl_seed_info seed_list[ABL_SEED_LIST_MAX];
};

static const char *abl_seed_arg[] = {
		"ABL.svnseed=",
		"dev_sec_info.param_addr=",
		NULL
};

static void parse_seed_list_abl(void *param_addr)
{
	uint32_t i;
	uint32_t legacy_seed_index = 0U;
	struct seed_info dseed_list[BOOTLOADER_SEED_MAX_ENTRIES];
	struct dev_sec_info *sec_info = (struct dev_sec_info *)param_addr;
	bool parse_success = false;

	if ((sec_info != NULL) && (sec_info->num_seeds >= 2U) && (sec_info->num_seeds <= ABL_SEED_LIST_MAX)) {
		/*
		 * The seed_list from ABL contains several seeds which based on SVN
		 * and one legacy seed which is not based on SVN. The legacy seed's
		 * svn value is minimum in the seed list. And CSE ensures at least two
		 * seeds will be generated which will contain the legacy seed.
		 * Here find the legacy seed index first.
		 */
		for (i = 1U; i < sec_info->num_seeds; i++) {
			if (sec_info->seed_list[i].svn < sec_info->seed_list[legacy_seed_index].svn) {
				legacy_seed_index = i;
			}
		}

		/*
		 * Copy out abl_seed for trusty and clear the original seed in memory.
		 * The SOS requires the legacy seed to derive RPMB key. So skip the
		 * legacy seed when clear original seed.
		 */
		(void)memset((void *)dseed_list, 0U, (BOOTLOADER_SEED_MAX_ENTRIES * sizeof(struct seed_info)));
		for (i = 0U; i < sec_info->num_seeds; i++) {
			dseed_list[i].cse_svn = sec_info->seed_list[i].svn;
			(void)memcpy_s((void *)dseed_list[i].seed, sizeof(dseed_list[i].seed),
					(void *)sec_info->seed_list[i].seed, sizeof(sec_info->seed_list[i].seed));

			if (i == legacy_seed_index) {
				continue;
			}

			(void)memset((void *)sec_info->seed_list[i].seed, 0U, sizeof(sec_info->seed_list[i].seed));
		}

		parse_success = true;
	}

	if (parse_success) {
		trusty_set_dseed((void *)dseed_list, (uint8_t)(sec_info->num_seeds));
	} else {
		trusty_set_dseed(NULL, 0U);
	}

	(void)memset((void *)dseed_list, 0U, sizeof(dseed_list));
}

/*
 * abl_seed_parse
 *
 * description:
 *    This function parse dev_sec_info from cmdline. Mainly on
 *    1. parse structure address from cmdline
 *    2. call  parse_seed_list_abl to parse seed_list
 *    3. convert address in the structure from HPA to SOS's GPA
 *    4. clear original image_boot_params argument in cmdline since
 *       original address is HPA.
 *
 * input:
 *    cmdline       pointer to cmdline string
 *    out_len       the max len of out_arg
 *
 * output:
 *    out_arg       the argument with SOS's GPA
 *
 * return value:
 *    true if parse successfully, otherwise false.
 */
bool abl_seed_parse(char *cmdline, char *out_arg, uint32_t out_len)
{
	char *arg = NULL, *arg_end;
	char *param;
	void *param_addr;
	uint32_t len = 0U, i;
	bool parse_success = false;

	if (cmdline != NULL) {

		for (i = 0U; abl_seed_arg[i] != NULL; i++) {
			len = strnlen_s(abl_seed_arg[i], MEM_1K);
			arg = strstr_s((const char *)cmdline, MEM_2K, abl_seed_arg[i], len);
			if (arg != NULL) {
				break;
			}
		}

		if (arg != NULL) {
			param = arg + len;
			param_addr = (void *)hpa2hva(strtoul_hex(param));
			if (param_addr != NULL) {
				parse_seed_list_abl(param_addr);

				/*
				 * Replace original arguments with spaces since SOS's GPA is not
				 * identity mapped to HPA. The argument will be appended later when
				 * compose cmdline for SOS.
				 */
				arg_end = strchr(arg, ' ');
				len = (arg_end != NULL) ? (uint32_t)(arg_end - arg) : strnlen_s(arg, MEM_2K);
				(void)memset((void *)arg, ' ', len);

				/* Convert the param_addr to SOS GPA and copy to caller */
				if (out_arg != NULL) {
					snprintf(out_arg, out_len, "%s0x%X ",
							abl_seed_arg[i], sos_vm_hpa2gpa(hva2hpa(param_addr)));
				}

				parse_success = true;
			}
		}
	}

	if (!parse_success) {
		parse_seed_list_abl(NULL);
	}

	return parse_success;
}