From: Björn Töpel <bjorn.to...@intel.com>
The bpf_xsk_redirect function is a new redirect bpf function, in
addition to bpf_redirect/bpf_redirect_map. If an XDP socket has been
attached to a netdev Rx queue via the XDP_ATTACH bind() option and
bpf_xsk_redirect is called, the packet will be redirected to the
attached socket.
The bpf_xsk_redirect function returns XDP_REDIRECT if there is a
socket attached to the originated queue, otherwise XDP_PASS.
This commit also adds the corresponding trace points for the redirect
call.
Signed-off-by: Björn Töpel <bjorn.to...@intel.com>
---
include/linux/filter.h | 4 ++
include/trace/events/xdp.h | 61 ++++++++++++++++++++++
include/uapi/linux/bpf.h | 14 +++++-
net/core/filter.c | 100 +++++++++++++++++++++++++++++++++++++
4 files changed, 178 insertions(+), 1 deletion(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index d16deead65c6..691b5c1003c8 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -525,6 +525,10 @@ struct bpf_redirect_info {
u32 flags;
struct bpf_map *map;
struct bpf_map *map_to_flush;
+#ifdef CONFIG_XDP_SOCKETS
+ struct xdp_sock *xsk;
+ struct xdp_sock *xsk_to_flush;
+#endif
u32 kern_flags;
};
diff --git a/include/trace/events/xdp.h b/include/trace/events/xdp.h
index e95cb86b65cf..30f399bd462b 100644
--- a/include/trace/events/xdp.h
+++ b/include/trace/events/xdp.h
@@ -158,6 +158,67 @@ struct _bpf_dtab_netdev {
trace_xdp_redirect_map_err(dev, xdp, devmap_ifindex(fwd, map), \
err, map, idx)
+DECLARE_EVENT_CLASS(xsk_redirect_template,
+
+ TP_PROTO(const struct net_device *dev,
+ const struct bpf_prog *xdp,
+ int err,
+ struct xdp_buff *xbuff),
+
+ TP_ARGS(dev, xdp, err, xbuff),
+
+ TP_STRUCT__entry(
+ __field(int, prog_id)
+ __field(u32, act)
+ __field(int, ifindex)
+ __field(int, err)
+ __field(u32, queue_index)
+ __field(enum xdp_mem_type, mem_type)
+ ),
+
+ TP_fast_assign(
+ __entry->prog_id = xdp->aux->id;
+ __entry->act = XDP_REDIRECT;
+ __entry->ifindex = dev->ifindex;
+ __entry->err = err;
+ __entry->queue_index = xbuff->rxq->queue_index;
+ __entry->mem_type = xbuff->rxq->mem.type;
+ ),
+
+ TP_printk("prog_id=%d action=%s ifindex=%d err=%d queue_index=%d"
+ " mem_type=%d",
+ __entry->prog_id,
+ __print_symbolic(__entry->act, __XDP_ACT_SYM_TAB),
+ __entry->ifindex,
+ __entry->err,
+ __entry->queue_index,
+ __entry->mem_type)
+);
+
+DEFINE_EVENT(xsk_redirect_template, xsk_redirect,
+ TP_PROTO(const struct net_device *dev,
+ const struct bpf_prog *xdp,
+ int err,
+ struct xdp_buff *xbuff),
+
+ TP_ARGS(dev, xdp, err, xbuff)
+);
+
+DEFINE_EVENT(xsk_redirect_template, xsk_redirect_err,
+ TP_PROTO(const struct net_device *dev,
+ const struct bpf_prog *xdp,
+ int err,
+ struct xdp_buff *xbuff),
+
+ TP_ARGS(dev, xdp, err, xbuff)
+);
+
+#define _trace_xsk_redirect(dev, xdp, xbuff) \
+ trace_xsk_redirect(dev, xdp, 0, xbuff)
+
+#define _trace_xsk_redirect_err(dev, xdp, xbuff, err) \
+ trace_xsk_redirect_err(dev, xdp, err, xbuff)
+
TRACE_EVENT(xdp_cpumap_kthread,
TP_PROTO(int map_id, unsigned int processed, unsigned int drops,
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index a84fd232d934..2912d87a39ba 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -2298,6 +2298,17 @@ union bpf_attr {
* payload and/or *pop* value being to large.
* Return
* 0 on success, or a negative error in case of failure.
+ *
+ * int bpf_xsk_redirect(struct xdp_buff *xdp_md)
+ * Description
+ * Redirect the packet to the attached XDP socket, if any.
+ * An XDP socket can be attached to a network interface Rx
+ * queue by passing the XDP_ATTACH option at bind point of
+ * the socket.
+ *
+ * Return
+ * **XDP_REDIRECT** if there is an XDP socket attached to the Rx
+ * queue receiving the frame, otherwise **XDP_PASS**.
*/
#define __BPF_FUNC_MAPPER(FN) \
FN(unspec), \
@@ -2391,7 +2402,8 @@ union bpf_attr {
FN(map_pop_elem), \
FN(map_peek_elem), \
FN(msg_push_data), \
- FN(msg_pop_data),
+ FN(msg_pop_data), \
+ FN(xsk_redirect),
/* integer value in 'imm' field of BPF_CALL instruction selects which helper
* function eBPF program intends to call
diff --git a/net/core/filter.c b/net/core/filter.c
index 3d54af4c363d..86c5fe5a9ec0 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3415,6 +3415,17 @@ static int __bpf_tx_xdp_map(struct net_device *dev_rx,
void *fwd,
return 0;
}
+static void xdp_do_flush_xsk(struct bpf_redirect_info *ri)
+{
+#ifdef CONFIG_XDP_SOCKETS
+ struct xdp_sock *xsk = ri->xsk_to_flush;
+
+ ri->xsk_to_flush = NULL;
+ if (xsk)
+ xsk_flush(xsk);
+#endif
+}
+
void xdp_do_flush_map(void)
{
struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
@@ -3436,6 +3447,8 @@ void xdp_do_flush_map(void)
break;
}
}
+
+ xdp_do_flush_xsk(ri);
}
EXPORT_SYMBOL_GPL(xdp_do_flush_map);
@@ -3501,6 +3514,30 @@ static int xdp_do_redirect_map(struct net_device *dev,
struct xdp_buff *xdp,
return err;
}
+#ifdef CONFIG_XDP_SOCKETS
+static int xdp_do_xsk_redirect(struct net_device *dev, struct xdp_buff *xdp,
+ struct bpf_prog *xdp_prog,
+ struct bpf_redirect_info *ri)
+{
+ struct xdp_sock *xsk = ri->xsk;
+ int err;
+
+ ri->xsk = NULL;
+ ri->xsk_to_flush = xsk;
+
+ err = xsk_attached_rcv(xsk, xdp);
+ if (unlikely(err))
+ goto err;
+
+ _trace_xsk_redirect(dev, xdp_prog, xdp);
+ return 0;
+
+err:
+ _trace_xsk_redirect_err(dev, xdp_prog, xdp, err);
+ return err;
+}
+#endif /* CONFIG_XDP_SOCKETS */
+
int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp,
struct bpf_prog *xdp_prog)
{
@@ -3510,6 +3547,10 @@ int xdp_do_redirect(struct net_device *dev, struct
xdp_buff *xdp,
if (likely(map))
return xdp_do_redirect_map(dev, xdp, xdp_prog, map, ri);
+#ifdef CONFIG_XDP_SOCKETS
+ if (ri->xsk)
+ return xdp_do_xsk_redirect(dev, xdp, xdp_prog, ri);
+#endif
return xdp_do_redirect_slow(dev, xdp, xdp_prog, ri);
}
EXPORT_SYMBOL_GPL(xdp_do_redirect);
@@ -3560,6 +3601,33 @@ static int xdp_do_generic_redirect_map(struct net_device
*dev,
return err;
}
+#ifdef CONFIG_XDP_SOCKETS
+static int xdp_do_generic_xsk_redirect(struct net_device *dev,
+ struct xdp_buff *xdp,
+ struct bpf_prog *xdp_prog,
+ struct sk_buff *skb)
+{
+ struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
+ struct xdp_sock *xsk = ri->xsk;
+ int err;
+
+ ri->xsk = NULL;
+ ri->xsk_to_flush = NULL;
+
+ err = xsk_generic_attached_rcv(xsk, xdp);
+ if (err)
+ goto err;
+
+ consume_skb(skb);
+ _trace_xsk_redirect(dev, xdp_prog, xdp);
+ return 0;
+
+err:
+ _trace_xsk_redirect_err(dev, xdp_prog, xdp, err);
+ return err;
+}
+#endif /* CONFIG_XDP_SOCKETS */
+
int xdp_do_generic_redirect(struct net_device *dev, struct sk_buff *skb,
struct xdp_buff *xdp, struct bpf_prog *xdp_prog)
{
@@ -3572,6 +3640,11 @@ int xdp_do_generic_redirect(struct net_device *dev,
struct sk_buff *skb,
if (map)
return xdp_do_generic_redirect_map(dev, skb, xdp, xdp_prog,
map);
+#ifdef CONFIG_XDP_SOCKETS
+ if (ri->xsk)
+ return xdp_do_generic_xsk_redirect(dev, xdp, xdp_prog, skb);
+#endif
+
ri->ifindex = 0;
fwd = dev_get_by_index_rcu(dev_net(dev), index);
if (unlikely(!fwd)) {
@@ -3639,6 +3712,29 @@ static const struct bpf_func_proto
bpf_xdp_redirect_map_proto = {
.arg3_type = ARG_ANYTHING,
};
+#ifdef CONFIG_XDP_SOCKETS
+BPF_CALL_1(bpf_xdp_xsk_redirect, struct xdp_buff *, xdp)
+{
+ struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info);
+ struct xdp_sock *xsk;
+
+ xsk = READ_ONCE(xdp->rxq->dev->_rx[xdp->rxq->queue_index].xsk);
+ if (xsk) {
+ ri->xsk = xsk;
+ return XDP_REDIRECT;
+ }
+
+ return XDP_PASS;
+}
+
+static const struct bpf_func_proto bpf_xdp_xsk_redirect_proto = {
+ .func = bpf_xdp_xsk_redirect,
+ .gpl_only = false,
+ .ret_type = RET_INTEGER,
+ .arg1_type = ARG_PTR_TO_CTX,
+};
+#endif /* CONFIG_XDP_SOCKETS */
+
static unsigned long bpf_skb_copy(void *dst_buff, const void *skb,
unsigned long off, unsigned long len)
{
@@ -5510,6 +5606,10 @@ xdp_func_proto(enum bpf_func_id func_id, const struct
bpf_prog *prog)
return &bpf_xdp_sk_lookup_tcp_proto;
case BPF_FUNC_sk_release:
return &bpf_sk_release_proto;
+#endif
+#ifdef CONFIG_XDP_SOCKETS
+ case BPF_FUNC_xsk_redirect:
+ return &bpf_xdp_xsk_redirect_proto;
#endif
default:
return bpf_base_func_proto(func_id);
--
2.19.1
