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@linaro.org --- 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;