With this command we are finally updating data to the backing store
and cycling the write_count and each successful write. We also include
the write count in all response frames as the spec is a little unclear
but the example test code expected it.
Signed-off-by: Alex Bennée <alex.bennee@xxxxxxxxxx>
---
tools/vhost-user-rpmb/main.c | 111 +++++++++++++++++++++++++++++++++--
1 file changed, 105 insertions(+), 6 deletions(-)
diff --git a/tools/vhost-user-rpmb/main.c b/tools/vhost-user-rpmb/main.c
index 88747c50fa44..a17c3b4bcc4e 100644
--- a/tools/vhost-user-rpmb/main.c
+++ b/tools/vhost-user-rpmb/main.c
@@ -62,6 +62,7 @@ enum {
#define KiB (1UL << 10)
#define MAX_RPMB_SIZE (KiB * 128 * 256)
#define RPMB_KEY_MAC_SIZE 32
+#define RPMB_BLOCK_SIZE 256
/* RPMB Request Types */
#define VIRTIO_RPMB_REQ_PROGRAM_KEY 0x0001
@@ -100,7 +101,7 @@ struct virtio_rpmb_config {
struct virtio_rpmb_frame {
uint8_t stuff[196];
uint8_t key_mac[RPMB_KEY_MAC_SIZE];
- uint8_t data[256];
+ uint8_t data[RPMB_BLOCK_SIZE];
uint8_t nonce[16];
/* remaining fields are big-endian */
uint32_t write_counter;
@@ -124,6 +125,7 @@ typedef struct VuRpmb {
uint8_t last_nonce[16];
uint16_t last_result;
uint16_t last_reqresp;
+ uint16_t last_address;
uint32_t write_count;
} VuRpmb;
@@ -239,17 +241,30 @@ vrpmb_set_config(VuDev *dev, const uint8_t *data,
* which itself uses a 3 clause BSD chunk of code.
*/
+static const int rpmb_frame_dlen = (sizeof(struct virtio_rpmb_frame) -
+ offsetof(struct virtio_rpmb_frame, data));
+
static void vrpmb_update_mac_in_frame(VuRpmb *r, struct virtio_rpmb_frame *frm)
{
hmac_sha256_ctx ctx;
- static const int dlen = (sizeof(struct virtio_rpmb_frame) -
- offsetof(struct virtio_rpmb_frame, data));
hmac_sha256_init(&ctx, r->key, RPMB_KEY_MAC_SIZE);
- hmac_sha256_update(&ctx, frm->data, dlen);
+ hmac_sha256_update(&ctx, frm->data, rpmb_frame_dlen);
hmac_sha256_final(&ctx, &frm->key_mac[0], 32);
}
+static bool vrpmb_verify_mac_in_frame(VuRpmb *r, struct virtio_rpmb_frame *frm)
+{
+ hmac_sha256_ctx ctx;
+ uint8_t calculated_mac[RPMB_KEY_MAC_SIZE];
+
+ hmac_sha256_init(&ctx, r->key, RPMB_KEY_MAC_SIZE);
+ hmac_sha256_update(&ctx, frm->data, rpmb_frame_dlen);
+ hmac_sha256_final(&ctx, calculated_mac, RPMB_KEY_MAC_SIZE);
+
+ return memcmp(calculated_mac, frm->key_mac, RPMB_KEY_MAC_SIZE) == 0;
+}
+
/*
* Handlers for individual control messages
*/
@@ -324,6 +339,82 @@ vrpmb_handle_get_write_counter(VuDev *dev, struct virtio_rpmb_frame *frame)
return resp;
}
+/*
+ * vrpmb_handle_write:
+ *
+ * We will report the success/fail on receipt of
+ * VIRTIO_RPMB_REQ_RESULT_READ. Returns the number of extra frames
+ * processed in the request.
+ */
+static int vrpmb_handle_write(VuDev *dev, struct virtio_rpmb_frame *frame)
+{
+ VuRpmb *r = container_of(dev, VuRpmb, dev.parent);
+ int extra_frames = 0;
+ uint16_t block_count = be16toh(frame->block_count);
+ uint32_t write_counter = be32toh(frame->write_counter);
+ size_t offset;
+
+ r->last_reqresp = VIRTIO_RPMB_RESP_DATA_WRITE;
+ r->last_address = be16toh(frame->address);
+ offset = r->last_address * RPMB_BLOCK_SIZE;
+
+ /*
+ * Run the checks from:
+ * 5.12.6.1.3 Device Requirements: Device Operation: Data Write
+ */
+ if (!r->key) {
+ g_warning("no key programmed");
+ r->last_result = VIRTIO_RPMB_RES_NO_AUTH_KEY;
+ } else if (block_count == 0 ||
+ block_count > r->virtio_config.max_wr_cnt) {
+ r->last_result = VIRTIO_RPMB_RES_GENERAL_FAILURE;
+ } else if (false /* what does an expired write counter mean? */) {
+ r->last_result = VIRTIO_RPMB_RES_WRITE_COUNTER_EXPIRED;
+ } else if (offset > (r->virtio_config.capacity * (128 * KiB))) {
+ r->last_result = VIRTIO_RPMB_RES_ADDR_FAILURE;
+ } else if (!vrpmb_verify_mac_in_frame(r, frame)) {
+ r->last_result = VIRTIO_RPMB_RES_AUTH_FAILURE;
+ } else if (write_counter != r->write_count) {
+ r->last_result = VIRTIO_RPMB_RES_COUNT_FAILURE;
+ } else {
+ int i;
+ /* At this point we have a valid authenticated write request
+ * so the counter can incremented and we can attempt to
+ * update the backing device.
+ */
+ r->write_count++;
+ for (i = 0; i < block_count; i++) {
+ void *blk = r->flash_map + offset;
+ g_debug("%s: writing block %d", __func__, i);
+ if (mprotect(blk, RPMB_BLOCK_SIZE, PROT_WRITE) != 0) {
+ r->last_result = VIRTIO_RPMB_RES_WRITE_FAILURE;
+ break;
+ }
+ memcpy(blk, frame[i].data, RPMB_BLOCK_SIZE);
+ if (msync(blk, RPMB_BLOCK_SIZE, MS_SYNC) != 0) {
+ g_warning("%s: failed to sync update", __func__);
+ r->last_result = VIRTIO_RPMB_RES_WRITE_FAILURE;
+ break;
+ }
+ if (mprotect(blk, RPMB_BLOCK_SIZE, PROT_READ) != 0) {
+ g_warning("%s: failed to re-apply read protection", __func__);
+ r->last_result = VIRTIO_RPMB_RES_GENERAL_FAILURE;
+ break;
+ }
+ offset += RPMB_BLOCK_SIZE;
+ }
+ r->last_result = VIRTIO_RPMB_RES_OK;
+ extra_frames = i - 1;
+ }
+
+ g_info("%s: %s (%x, %d extra frames processed), write_count=%d", __func__,
+ r->last_result == VIRTIO_RPMB_RES_OK ? "successful":"failed",
+ r->last_result, extra_frames, r->write_count);
+
+ return extra_frames;
+}
+
+
/*
* Return the result of the last message. This is only valid if the
* previous message was VIRTIO_RPMB_REQ_PROGRAM_KEY or
@@ -339,10 +430,14 @@ static struct virtio_rpmb_frame * vrpmb_handle_result_read(VuDev *dev)
g_info("%s: for request:%x result:%x", __func__,
r->last_reqresp, r->last_result);
- if (r->last_reqresp == VIRTIO_RPMB_RESP_PROGRAM_KEY ||
- r->last_reqresp == VIRTIO_RPMB_REQ_DATA_WRITE) {
+ if (r->last_reqresp == VIRTIO_RPMB_RESP_PROGRAM_KEY) {
resp->result = htobe16(r->last_result);
resp->req_resp = htobe16(r->last_reqresp);
+ } else if (r->last_reqresp == VIRTIO_RPMB_RESP_DATA_WRITE) {
+ resp->result = htobe16(r->last_result);
+ resp->req_resp = htobe16(r->last_reqresp);
+ resp->write_counter = htobe32(r->write_count);
+ resp->address = htobe16(r->last_address);
} else {
resp->result = htobe16(VIRTIO_RPMB_RES_GENERAL_FAILURE);
}
@@ -445,6 +540,10 @@ vrpmb_handle_ctrl(VuDev *dev, int qidx)
__func__);
}
break;
+ case VIRTIO_RPMB_REQ_DATA_WRITE:
+ /* we can have multiple blocks handled */
+ n += vrpmb_handle_write(dev, f);
+ break;
default:
g_debug("un-handled request: %x", f->req_resp);
break;
--
2.20.1
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