The read command is a lot simpler to implement. However the spec does specify you can only read a single block at a time so we limit it to that.
Signed-off-by: Alex Bennée alex.bennee@linaro.org --- tools/vhost-user-rpmb/main.c | 52 ++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+)
diff --git a/tools/vhost-user-rpmb/main.c b/tools/vhost-user-rpmb/main.c index a17c3b4bcc4e..49d4e00b24a9 100644 --- a/tools/vhost-user-rpmb/main.c +++ b/tools/vhost-user-rpmb/main.c @@ -414,6 +414,55 @@ static int vrpmb_handle_write(VuDev *dev, struct virtio_rpmb_frame *frame) return extra_frames; }
+/* + * vrpmb_handle_read: + * + * Unlike the write operation we return a frame with the result of the + * read here. While the config specifies a maximum read count the spec + * is limited to a single read at a time. + */ +static struct virtio_rpmb_frame * +vrpmb_handle_read(VuDev *dev, struct virtio_rpmb_frame *frame) +{ + VuRpmb *r = container_of(dev, VuRpmb, dev.parent); + size_t offset = be16toh(frame->address) * RPMB_BLOCK_SIZE; + uint16_t block_count = be16toh(frame->block_count); + struct virtio_rpmb_frame *resp = g_new0(struct virtio_rpmb_frame, 1); + + resp->req_resp = htobe16(VIRTIO_RPMB_RESP_DATA_READ); + resp->address = frame->address; + resp->block_count = htobe16(1); + + /* + * Run the checks from: + * 5.12.6.1.4 Device Requirements: Device Operation: Data Read + */ + if (!r->key) { + g_warning("no key programmed"); + resp->result = htobe16(VIRTIO_RPMB_RES_NO_AUTH_KEY); + } else if (block_count != 1) { + /* + * Despite the config the spec only allows for reading one + * block at a time: "If block count has not been set to 1 then + * VIRTIO_RPMB_RES_GENERAL_FAILURE SHOULD be responded as + * result." + */ + resp->result = htobe16(VIRTIO_RPMB_RES_GENERAL_FAILURE); + } else if (offset > (r->virtio_config.capacity * (128 * KiB))) { + resp->result = htobe16(VIRTIO_RPMB_RES_ADDR_FAILURE); + } else { + void *blk = r->flash_map + offset; + g_debug("%s: reading block from %p (%zu)", __func__, blk, offset); + memcpy(resp->data, blk, RPMB_BLOCK_SIZE); + resp->result = htobe16(VIRTIO_RPMB_RES_OK); + } + + /* Final housekeeping, copy nonce and calculate MAC */ + memcpy(&resp->nonce, &frame->nonce, sizeof(frame->nonce)); + vrpmb_update_mac_in_frame(r, resp); + + return resp; +}
/* * Return the result of the last message. This is only valid if the @@ -544,6 +593,9 @@ vrpmb_handle_ctrl(VuDev *dev, int qidx) /* we can have multiple blocks handled */ n += vrpmb_handle_write(dev, f); break; + case VIRTIO_RPMB_REQ_DATA_READ: + resp = vrpmb_handle_read(dev, f); + break; default: g_debug("un-handled request: %x", f->req_resp); break;