nvme-tcp: validate R2T PDU in nvme_tcp_handle_r2t()

If maxh2cdata < r2t_length then driver will form multiple
H2CData PDUs, validate R2T PDU in nvme_tcp_handle_r2t() to
reuse nvme_tcp_setup_h2c_data_pdu().

Also set req->state to NVME_TCP_SEND_H2C_PDU in
nvme_tcp_setup_h2c_data_pdu().

Signed-off-by: Varun Prakash <varun@chelsio.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 33bc83d..5f8ad4d 100644 (file)
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -572,7 +572,7 @@ static int nvme_tcp_handle_comp(struct nvme_tcp_queue *queue,
        return ret;
 }
 
-static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
+static void nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
                struct nvme_tcp_r2t_pdu *pdu)
 {
        struct nvme_tcp_data_pdu *data = req->pdu;
@@ -581,32 +581,11 @@ static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
        u8 hdgst = nvme_tcp_hdgst_len(queue);
        u8 ddgst = nvme_tcp_ddgst_len(queue);
 
+       req->state = NVME_TCP_SEND_H2C_PDU;
+       req->offset = 0;
        req->pdu_len = le32_to_cpu(pdu->r2t_length);
        req->pdu_sent = 0;
 
-       if (unlikely(!req->pdu_len)) {
-               dev_err(queue->ctrl->ctrl.device,
-                       "req %d r2t len is %u, probably a bug...\n",
-                       rq->tag, req->pdu_len);
-               return -EPROTO;
-       }
-
-       if (unlikely(req->data_sent + req->pdu_len > req->data_len)) {
-               dev_err(queue->ctrl->ctrl.device,
-                       "req %d r2t len %u exceeded data len %u (%zu sent)\n",
-                       rq->tag, req->pdu_len, req->data_len,
-                       req->data_sent);
-               return -EPROTO;
-       }
-
-       if (unlikely(le32_to_cpu(pdu->r2t_offset) < req->data_sent)) {
-               dev_err(queue->ctrl->ctrl.device,
-                       "req %d unexpected r2t offset %u (expected %zu)\n",
-                       rq->tag, le32_to_cpu(pdu->r2t_offset),
-                       req->data_sent);
-               return -EPROTO;
-       }
-
        memset(data, 0, sizeof(*data));
        data->hdr.type = nvme_tcp_h2c_data;
        data->hdr.flags = NVME_TCP_F_DATA_LAST;
@@ -622,7 +601,6 @@ static int nvme_tcp_setup_h2c_data_pdu(struct nvme_tcp_request *req,
        data->command_id = nvme_cid(rq);
        data->data_offset = pdu->r2t_offset;
        data->data_length = cpu_to_le32(req->pdu_len);
-       return 0;
 }
 
 static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
@@ -630,7 +608,7 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
 {
        struct nvme_tcp_request *req;
        struct request *rq;
-       int ret;
+       u32 r2t_length = le32_to_cpu(pdu->r2t_length);
 
        rq = nvme_find_rq(nvme_tcp_tagset(queue), pdu->command_id);
        if (!rq) {
@@ -641,13 +619,28 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
        }
        req = blk_mq_rq_to_pdu(rq);
 
-       ret = nvme_tcp_setup_h2c_data_pdu(req, pdu);
-       if (unlikely(ret))
-               return ret;
+       if (unlikely(!r2t_length)) {
+               dev_err(queue->ctrl->ctrl.device,
+                       "req %d r2t len is %u, probably a bug...\n",
+                       rq->tag, r2t_length);
+               return -EPROTO;
+       }
 
-       req->state = NVME_TCP_SEND_H2C_PDU;
-       req->offset = 0;
+       if (unlikely(req->data_sent + r2t_length > req->data_len)) {
+               dev_err(queue->ctrl->ctrl.device,
+                       "req %d r2t len %u exceeded data len %u (%zu sent)\n",
+                       rq->tag, r2t_length, req->data_len, req->data_sent);
+               return -EPROTO;
+       }
+
+       if (unlikely(le32_to_cpu(pdu->r2t_offset) < req->data_sent)) {
+               dev_err(queue->ctrl->ctrl.device,
+                       "req %d unexpected r2t offset %u (expected %zu)\n",
+                       rq->tag, le32_to_cpu(pdu->r2t_offset), req->data_sent);
+               return -EPROTO;
+       }
 
+       nvme_tcp_setup_h2c_data_pdu(req, pdu);
        nvme_tcp_queue_request(req, false, true);
 
        return 0;