IB/core: Add raw packet QP type

IB_QPT_RAW_PACKET allows applications to build a complete packet,
including L2 headers, when sending; on the receive side, the HW will
not strip any headers.

This QP type is designed for userspace direct access to Ethernet; for
example by applications that do TCP/IP themselves.  Only processes
with the NET_RAW capability are allowed to create raw packet QPs (the
name "raw packet QP" is supposed to suggest an analogy to AF_PACKET /
SOL_RAW sockets).
Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Reviewed-by: Sean Hefty <sean.hefty@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/core/uverbs_cmd.c

@@ -1399,6 +1399,9 @@ ssize_t ib_uverbs_create_qp(struct ib_uverbs_file *file,
 	if (copy_from_user(&cmd, buf, sizeof cmd))
 		return -EFAULT;
 
+	if (cmd.qp_type == IB_QPT_RAW_PACKET && !capable(CAP_NET_RAW))
+		return -EPERM;
+
 	INIT_UDATA(&udata, buf + sizeof cmd,
 		   (unsigned long) cmd.response + sizeof resp,
 		   in_len - sizeof cmd, out_len - sizeof resp);

drivers/infiniband/core/verbs.c

@@ -479,6 +479,7 @@ static const struct {
 				[IB_QPT_UD]  = (IB_QP_PKEY_INDEX		|
 						IB_QP_PORT			|
 						IB_QP_QKEY),
+				[IB_QPT_RAW_PACKET] = IB_QP_PORT,
 				[IB_QPT_UC]  = (IB_QP_PKEY_INDEX		|
 						IB_QP_PORT			|
 						IB_QP_ACCESS_FLAGS),

include/rdma/ib_verbs.h

@@ -605,7 +605,7 @@ enum ib_qp_type {
 	IB_QPT_UD,
 	IB_QPT_RAW_IPV6,
 	IB_QPT_RAW_ETHERTYPE,
-	/* Save 8 for RAW_PACKET */
+	IB_QPT_RAW_PACKET = 8,
 	IB_QPT_XRC_INI = 9,
 	IB_QPT_XRC_TGT,
 	IB_QPT_MAX