/* SPDX-License-Identifier: BSD-2-Clause */
/*
 * Copyright (c) 2020 Infineon Technologies AG
 * All rights reserved.
 */

#ifdef HAVE_CONFIG_H
#include "config.h" // IWYU pragma: keep
#endif

#include <inttypes.h> // for PRIxPTR, uintptr_t, uint8_t, int32_t
#include <string.h>   // for NULL, size_t, memset

#include "tcti-common.h"     // for TSS2_TCTI_COMMON_CONTEXT, TCTI_STATE_...
#include "tss2_common.h"     // for TSS2_RC_SUCCESS, TSS2_RC, TSS2_TCTI_R...
#include "tss2_tcti.h"       // for TSS2_TCTI_CONTEXT, TSS2_TCTI_INFO
#include "tss2_tpm2_types.h" // for TPM2_RC_SUCCESS

#define LOGMODULE tcti
#include "tcti-pcap-builder.h" // for pcap_print, pcap_deinit, pcap_init
#include "tcti-pcap.h"
#include "tss2_tctildr.h" // for Tss2_TctiLdr_Finalize, Tss2_TctiLdr_I...
#include "util/log.h"     // for LOG_WARNING, LOG_ERROR, LOGBLOB_DEBUG

/*
 * This function wraps the "up-cast" of the opaque TCTI context type to the
 * type for the pcap TCTI context. The only safeguard we have to ensure this
 * operation is possible is the magic number in the pcap TCTI context.
 * If passed a NULL context, or the magic number check fails, this function
 * will return NULL.
 */
TSS2_TCTI_PCAP_CONTEXT *
tcti_pcap_context_cast(TSS2_TCTI_CONTEXT *tcti_ctx) {
    if (tcti_ctx != NULL && TSS2_TCTI_MAGIC(tcti_ctx) == TCTI_PCAP_MAGIC) {
        return (TSS2_TCTI_PCAP_CONTEXT *)tcti_ctx;
    }
    return NULL;
}

/*
 * This function down-casts the pcap TCTI context to the common context
 * defined in the tcti-common module.
 */
TSS2_TCTI_COMMON_CONTEXT *
tcti_pcap_down_cast(TSS2_TCTI_PCAP_CONTEXT *tcti_pcap) {
    if (tcti_pcap == NULL) {
        return NULL;
    }
    return &tcti_pcap->common;
}

TSS2_RC
tcti_pcap_transmit(TSS2_TCTI_CONTEXT *tcti_ctx, size_t size, const uint8_t *cmd_buf) {
    TSS2_TCTI_PCAP_CONTEXT   *tcti_pcap = tcti_pcap_context_cast(tcti_ctx);
    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_pcap_down_cast(tcti_pcap);
    TSS2_RC                   rc;
    int                       ret;

    if (tcti_pcap == NULL) {
        return TSS2_TCTI_RC_BAD_CONTEXT;
    }
    rc = tcti_common_transmit_checks(tcti_common, cmd_buf, TCTI_PCAP_MAGIC);
    if (rc != TSS2_RC_SUCCESS) {
        return rc;
    }

    LOGBLOB_DEBUG(cmd_buf, size, "sending %zu byte command buffer:", size);

    /* handle errors of underlying TCTI later (always writes to PCAP file) */
    ret = pcap_print(&tcti_pcap->pcap_builder, cmd_buf, size, PCAP_DIR_HOST_TO_TPM);
    if (ret != 0) {
        LOG_WARNING("Failed to save transmission to PCAP file.");
    }

    rc = Tss2_Tcti_Transmit(tcti_pcap->tcti_child, size, cmd_buf);
    if (rc != TSS2_RC_SUCCESS) {
        LOG_ERROR("Failed calling TCTI transmit of child TCTI module");
        return rc;
    }

    tcti_common->state = TCTI_STATE_RECEIVE;
    return TSS2_RC_SUCCESS;
}

TSS2_RC
tcti_pcap_receive(TSS2_TCTI_CONTEXT *tctiContext,
                  size_t            *response_size,
                  unsigned char     *response_buffer,
                  int32_t            timeout) {
    TSS2_TCTI_PCAP_CONTEXT   *tcti_pcap = tcti_pcap_context_cast(tctiContext);
    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_pcap_down_cast(tcti_pcap);
    TSS2_RC                   rc;
    int                       ret;

    if (tcti_pcap == NULL) {
        return TSS2_TCTI_RC_BAD_CONTEXT;
    }
    rc = tcti_common_receive_checks(tcti_common, response_size, TCTI_PCAP_MAGIC);
    if (rc != TSS2_RC_SUCCESS) {
        return rc;
    }

    rc = Tss2_Tcti_Receive(tcti_pcap->tcti_child, response_size, response_buffer, timeout);
    /* handle errors of underlying TCTI directly (may not write to PCAP file) */
    if (rc != TPM2_RC_SUCCESS) {
        return rc;
    }

    /* partial read */
    if (response_buffer == NULL) {
        return rc;
    }

    LOGBLOB_DEBUG(response_buffer, *response_size, "Response Received");

    ret = pcap_print(&tcti_pcap->pcap_builder, response_buffer, *response_size,
                     PCAP_DIR_TPM_TO_HOST);
    if (ret != 0) {
        LOG_WARNING("Failed to save transmission to PCAP file.");
    }

    tcti_common->state = TCTI_STATE_TRANSMIT;
    return rc;
}

TSS2_RC
tcti_pcap_cancel(TSS2_TCTI_CONTEXT *tctiContext) {
    TSS2_TCTI_PCAP_CONTEXT   *tcti_pcap = tcti_pcap_context_cast(tctiContext);
    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_pcap_down_cast(tcti_pcap);
    TSS2_RC                   rc;

    if (tcti_pcap == NULL) {
        return TSS2_TCTI_RC_BAD_CONTEXT;
    }
    rc = tcti_common_cancel_checks(tcti_common, TCTI_PCAP_MAGIC);
    if (rc != TSS2_RC_SUCCESS) {
        return rc;
    }

    LOG_WARNING("Logging Tcti_Cancel to a PCAP file is not implemented");

    rc = Tss2_Tcti_Cancel(tcti_pcap->tcti_child);
    if (rc != TSS2_RC_SUCCESS) {
        return rc;
    }

    tcti_common->state = TCTI_STATE_TRANSMIT;
    return rc;
}

TSS2_RC
tcti_pcap_set_locality(TSS2_TCTI_CONTEXT *tctiContext, uint8_t locality) {
    TSS2_TCTI_PCAP_CONTEXT   *tcti_pcap = tcti_pcap_context_cast(tctiContext);
    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_pcap_down_cast(tcti_pcap);
    TSS2_RC                   rc;

    if (tcti_pcap == NULL) {
        return TSS2_TCTI_RC_BAD_CONTEXT;
    }

    rc = tcti_common_set_locality_checks(tcti_common, TCTI_PCAP_MAGIC);
    if (rc != TSS2_RC_SUCCESS) {
        return rc;
    }

    LOG_WARNING("Logging Tcti_SetLocality to a PCAP file is not implemented");

    rc = Tss2_Tcti_SetLocality(tcti_pcap->tcti_child, locality);
    if (rc != TSS2_RC_SUCCESS) {
        return rc;
    }

    tcti_common->locality = locality;
    return rc;
}

TSS2_RC
tcti_pcap_get_poll_handles(TSS2_TCTI_CONTEXT     *tctiContext,
                           TSS2_TCTI_POLL_HANDLE *handles,
                           size_t                *num_handles) {
    TSS2_TCTI_PCAP_CONTEXT *tcti_pcap = tcti_pcap_context_cast(tctiContext);

    if (tcti_pcap == NULL) {
        return TSS2_TCTI_RC_BAD_CONTEXT;
    }

    return Tss2_Tcti_GetPollHandles(tcti_pcap->tcti_child, handles, num_handles);
}

void
tcti_pcap_finalize(TSS2_TCTI_CONTEXT *tctiContext) {
    TSS2_TCTI_PCAP_CONTEXT   *tcti_pcap = tcti_pcap_context_cast(tctiContext);
    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_pcap_down_cast(tcti_pcap);

    if (tcti_pcap == NULL) {
        return;
    }

    Tss2_TctiLdr_Finalize(&tcti_pcap->tcti_child);
    pcap_deinit(&tcti_pcap->pcap_builder);

    tcti_common->state = TCTI_STATE_FINAL;
}

/*
 * This is an implementation of the standard TCTI initialization function for
 * this module.
 */
TSS2_RC
Tss2_Tcti_Pcap_Init(TSS2_TCTI_CONTEXT *tctiContext, size_t *size, const char *conf) {
    TSS2_TCTI_PCAP_CONTEXT   *tcti_pcap = (TSS2_TCTI_PCAP_CONTEXT *)tctiContext;
    TSS2_TCTI_COMMON_CONTEXT *tcti_common = tcti_pcap_down_cast(tcti_pcap);
    TSS2_RC                   rc = TSS2_RC_SUCCESS;
    int                       ret;

    if (tctiContext == NULL && size == NULL) {
        return TSS2_TCTI_RC_BAD_VALUE;
    } else if (tctiContext == NULL) {
        *size = sizeof(TSS2_TCTI_PCAP_CONTEXT);
        return TSS2_RC_SUCCESS;
    }

    if (conf == NULL) {
        LOG_TRACE("tctiContext: 0x%" PRIxPTR ", size: 0x%" PRIxPTR ""
                  " no configuration will be used.",
                  (uintptr_t)tctiContext, (uintptr_t)size);
    } else {
        LOG_TRACE("tctiContext: 0x%" PRIxPTR ", size: 0x%" PRIxPTR ", conf: %s",
                  (uintptr_t)tctiContext, (uintptr_t)size, conf);
    }

    rc = Tss2_TctiLdr_Initialize(conf, &tcti_pcap->tcti_child);
    if (rc != TSS2_RC_SUCCESS) {
        LOG_ERROR("Error loading TCTI: %s", conf);
        return rc;
    }

    TSS2_TCTI_MAGIC(tcti_common) = TCTI_PCAP_MAGIC;
    TSS2_TCTI_VERSION(tcti_common) = TCTI_VERSION;
    TSS2_TCTI_TRANSMIT(tcti_common) = tcti_pcap_transmit;
    TSS2_TCTI_RECEIVE(tcti_common) = tcti_pcap_receive;
    TSS2_TCTI_FINALIZE(tcti_common) = tcti_pcap_finalize;
    TSS2_TCTI_CANCEL(tcti_common) = tcti_pcap_cancel;
    TSS2_TCTI_GET_POLL_HANDLES(tcti_common) = tcti_pcap_get_poll_handles;
    TSS2_TCTI_SET_LOCALITY(tcti_common) = tcti_pcap_set_locality;
    TSS2_TCTI_MAKE_STICKY(tcti_common) = tcti_make_sticky_not_implemented;
    tcti_common->state = TCTI_STATE_TRANSMIT;
    tcti_common->locality = 3;
    memset(&tcti_common->header, 0, sizeof(tcti_common->header));

    ret = pcap_init(&tcti_pcap->pcap_builder);
    if (ret != 0) {
        LOG_ERROR("Failed to initialize PCAP TCTI");
        Tss2_TctiLdr_Finalize(&tcti_pcap->tcti_child);
        return TSS2_TCTI_RC_IO_ERROR;
    }

    return TSS2_RC_SUCCESS;
}

/* public info structure */
static const TSS2_TCTI_INFO tss2_tcti_pcap_info = {
    .version = TCTI_VERSION,
    .name = "tcti-pcap",
    .description = "TCTI module for logging TPM commands in pcapng format.",
    .config_help = "The child tcti module and its config string: <name>:<conf>",
    .init = Tss2_Tcti_Pcap_Init,
};

const TSS2_TCTI_INFO *
Tss2_Tcti_Info(void) {
    return &tss2_tcti_pcap_info;
}
