nvme-tcp: add basic support for the C2HTermReq PDU

Previously, the NVMe/TCP host driver did not handle the C2HTermReq PDU,
instead printing "unsupported pdu type (3)" when received. This patch adds
support for processing the C2HTermReq PDU, allowing the driver
to print the Fatal Error Status field.

Example of output:
nvme nvme4: Received C2HTermReq (FES = Invalid PDU Header Field)

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c
index 841238f38fddabc4fe5cc5c976189d9c9b85f16a..038b35238c26d294951de3a3b9108a91e8e40208 100644 (file)
--- a/drivers/nvme/host/tcp.c
+++ b/drivers/nvme/host/tcp.c
@@ -763,6 +763,40 @@ static int nvme_tcp_handle_r2t(struct nvme_tcp_queue *queue,
        return 0;
 }
 
+static void nvme_tcp_handle_c2h_term(struct nvme_tcp_queue *queue,
+               struct nvme_tcp_term_pdu *pdu)
+{
+       u16 fes;
+       const char *msg;
+       u32 plen = le32_to_cpu(pdu->hdr.plen);
+
+       static const char * const msg_table[] = {
+               [NVME_TCP_FES_INVALID_PDU_HDR] = "Invalid PDU Header Field",
+               [NVME_TCP_FES_PDU_SEQ_ERR] = "PDU Sequence Error",
+               [NVME_TCP_FES_HDR_DIGEST_ERR] = "Header Digest Error",
+               [NVME_TCP_FES_DATA_OUT_OF_RANGE] = "Data Transfer Out Of Range",
+               [NVME_TCP_FES_R2T_LIMIT_EXCEEDED] = "R2T Limit Exceeded",
+               [NVME_TCP_FES_UNSUPPORTED_PARAM] = "Unsupported Parameter",
+       };
+
+       if (plen < NVME_TCP_MIN_C2HTERM_PLEN ||
+           plen > NVME_TCP_MAX_C2HTERM_PLEN) {
+               dev_err(queue->ctrl->ctrl.device,
+                       "Received a malformed C2HTermReq PDU (plen = %u)\n",
+                       plen);
+               return;
+       }
+
+       fes = le16_to_cpu(pdu->fes);
+       if (fes && fes < ARRAY_SIZE(msg_table))
+               msg = msg_table[fes];
+       else
+               msg = "Unknown";
+
+       dev_err(queue->ctrl->ctrl.device,
+               "Received C2HTermReq (FES = %s)\n", msg);
+}
+
 static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
                unsigned int *offset, size_t *len)
 {
@@ -784,6 +818,15 @@ static int nvme_tcp_recv_pdu(struct nvme_tcp_queue *queue, struct sk_buff *skb,
                return 0;
 
        hdr = queue->pdu;
+       if (unlikely(hdr->type == nvme_tcp_c2h_term)) {
+               /*
+                * C2HTermReq never includes Header or Data digests.
+                * Skip the checks.
+                */
+               nvme_tcp_handle_c2h_term(queue, (void *)queue->pdu);
+               return -EINVAL;
+       }
+
        if (queue->hdr_digest) {
                ret = nvme_tcp_verify_hdgst(queue, queue->pdu, hdr->hlen);
                if (unlikely(ret))

diff --git a/include/linux/nvme-tcp.h b/include/linux/nvme-tcp.h
index e07e8978d691b7943b729bc64cdb8f4da64a548d..e435250fcb4d05d5fc833076839163673e5380b8 100644 (file)
--- a/include/linux/nvme-tcp.h
+++ b/include/linux/nvme-tcp.h
@@ -13,6 +13,8 @@
 #define NVME_TCP_ADMIN_CCSZ    SZ_8K
 #define NVME_TCP_DIGEST_LENGTH 4
 #define NVME_TCP_MIN_MAXH2CDATA 4096
+#define NVME_TCP_MIN_C2HTERM_PLEN      24
+#define NVME_TCP_MAX_C2HTERM_PLEN      152
 
 enum nvme_tcp_pfv {
        NVME_TCP_PFV_1_0 = 0x0,