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@xxxxxxxxxx>
---
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;
--
2.20.1
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