Make it possible for the application to determine whether the AF_XDP
socket is running in zero-copy mode. To achieve this, add a new
getsockopt option XDP_OPTIONS that returns flags. The only flag
supported for now is the zero-copy mode indicator.
Signed-off-by: Maxim Mikityanskiy <maximmi@xxxxxxxxxxxx>
Reviewed-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
Acked-by: Saeed Mahameed <saeedm@xxxxxxxxxxxx>
---
include/uapi/linux/if_xdp.h | 8 ++++++++
net/xdp/xsk.c | 20 ++++++++++++++++++++
tools/include/uapi/linux/if_xdp.h | 8 ++++++++
3 files changed, 36 insertions(+)
diff --git a/include/uapi/linux/if_xdp.h b/include/uapi/linux/if_xdp.h
index caed8b1614ff..faaa5ca2a117 100644
--- a/include/uapi/linux/if_xdp.h
+++ b/include/uapi/linux/if_xdp.h
@@ -46,6 +46,7 @@ struct xdp_mmap_offsets {
#define XDP_UMEM_FILL_RING 5
#define XDP_UMEM_COMPLETION_RING 6
#define XDP_STATISTICS 7
+#define XDP_OPTIONS 8
struct xdp_umem_reg {
__u64 addr; /* Start of packet data area */
@@ -60,6 +61,13 @@ struct xdp_statistics {
__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
};
+struct xdp_options {
+ __u32 flags;
+};
+
+/* Flags for the flags field of struct xdp_options */
+#define XDP_OPTIONS_ZEROCOPY (1 << 0)
+
/* Pgoff for mmaping the rings */
#define XDP_PGOFF_RX_RING 0
#define XDP_PGOFF_TX_RING 0x80000000
diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c
index b68a380f50b3..35ca531ac74e 100644
--- a/net/xdp/xsk.c
+++ b/net/xdp/xsk.c
@@ -650,6 +650,26 @@ static int xsk_getsockopt(struct socket *sock, int level, int optname,
return 0;
}
+ case XDP_OPTIONS:
+ {
+ struct xdp_options opts = {};
+
+ if (len < sizeof(opts))
+ return -EINVAL;
+
+ mutex_lock(&xs->mutex);
+ if (xs->zc)
+ opts.flags |= XDP_OPTIONS_ZEROCOPY;
+ mutex_unlock(&xs->mutex);
+
+ len = sizeof(opts);
+ if (copy_to_user(optval, &opts, len))
+ return -EFAULT;
+ if (put_user(len, optlen))
+ return -EFAULT;
+
+ return 0;
+ }
default:
break;
}
diff --git a/tools/include/uapi/linux/if_xdp.h b/tools/include/uapi/linux/if_xdp.h
index caed8b1614ff..faaa5ca2a117 100644
--- a/tools/include/uapi/linux/if_xdp.h
+++ b/tools/include/uapi/linux/if_xdp.h
@@ -46,6 +46,7 @@ struct xdp_mmap_offsets {
#define XDP_UMEM_FILL_RING 5
#define XDP_UMEM_COMPLETION_RING 6
#define XDP_STATISTICS 7
+#define XDP_OPTIONS 8
struct xdp_umem_reg {
__u64 addr; /* Start of packet data area */
@@ -60,6 +61,13 @@ struct xdp_statistics {
__u64 tx_invalid_descs; /* Dropped due to invalid descriptor */
};
+struct xdp_options {
+ __u32 flags;
+};
+
+/* Flags for the flags field of struct xdp_options */
+#define XDP_OPTIONS_ZEROCOPY (1 << 0)
+
/* Pgoff for mmaping the rings */
#define XDP_PGOFF_RX_RING 0
#define XDP_PGOFF_TX_RING 0x80000000
--
2.19.1
