[PATCH] RDMA/rxe: Implement packet length validation on responder

Daisuke Matsuda
2022-10-28T09:05:01Z

The function check_length() is supposed to check the length of inbound
packets on responder, but it actually has been a stub since the driver was
born. Let it check the payload length and the DMA length.

Signed-off-by: Daisuke Matsuda <matsuda-daisuke@fujitsu.com>
---
FOR REVIEWERS
I referred to IB Specification Vol 1-Revision-1.5 to create this patch.
Please see 9.7.4.1.6 (page.330).

drivers/infiniband/sw/rxe/rxe_resp.c | 36 ++++++++++++++++++++++------
1 file changed, 29 insertions(+), 7 deletions(-)

diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c
index ed5a09e86417..62e3a8195072 100644
--- a/drivers/infiniband/sw/rxe/rxe_resp.c
+++ b/drivers/infiniband/sw/rxe/rxe_resp.c
@@ -390,16 +390,38 @@ static enum resp_states check_resource(struct rxe_qp *qp,
static enum resp_states check_length(struct rxe_qp *qp,
struct rxe_pkt_info *pkt)
{
- switch (qp_type(qp)) {
- case IB_QPT_RC:
- return RESPST_CHK_RKEY;
+ int mtu = qp->mtu;
+ u32 payload = payload_size(pkt);
+ u32 dmalen = reth_len(pkt);

- case IB_QPT_UC:
- return RESPST_CHK_RKEY;
+ /* RoCEv2 packets do not have LRH.
+ * Let's skip checking it.
+ */

- default:
- return RESPST_CHK_RKEY;
+ if ((pkt->opcode & RXE_START_MASK) &&
+ (pkt->opcode & RXE_END_MASK)) {
+ /* "only" packets */
+ if (payload > mtu)
+ return RESPST_ERR_LENGTH;
+
+ } else if ((pkt->opcode & RXE_START_MASK) ||
+ (pkt->opcode & RXE_MIDDLE_MASK)) {
+ /* "first" or "middle" packets */
+ if (payload != mtu)
+ return RESPST_ERR_LENGTH;
+
+ } else if (pkt->opcode & RXE_END_MASK) {
+ /* "last" packets */
+ if ((pkt->paylen == 0) || (pkt->paylen > mtu))
+ return RESPST_ERR_LENGTH;
+ }
+
+ if (pkt->opcode & (RXE_WRITE_MASK | RXE_READ_MASK)) {
+ if (dmalen > (1 << 31))
+ return RESPST_ERR_LENGTH;
}
+
+ return RESPST_CHK_RKEY;
}

static enum resp_states check_rkey(struct rxe_qp *qp,
--
2.31.1