struct list_head flush_node;
struct net_device *dev;
struct net_device *dev_rx;
+ struct bpf_prog *xdp_prog;
unsigned int count;
};
struct bpf_dtab {
struct bpf_map map;
- struct bpf_dtab_netdev **netdev_map; /* DEVMAP type only */
+ struct bpf_dtab_netdev __rcu **netdev_map; /* DEVMAP type only */
struct list_head list;
/* these are only used for DEVMAP_HASH type maps */
list_del_rcu(&dtab->list);
spin_unlock(&dev_map_lock);
+ bpf_clear_redirect_map(map);
synchronize_rcu();
/* Make sure prior __dev_map_entry_free() have completed. */
for (i = 0; i < dtab->map.max_entries; i++) {
struct bpf_dtab_netdev *dev;
- dev = dtab->netdev_map[i];
+ dev = rcu_dereference_raw(dtab->netdev_map[i]);
if (!dev)
continue;
return 0;
}
+/* Elements are kept alive by RCU; either by rcu_read_lock() (from syscall) or
+ * by local_bh_disable() (from XDP calls inside NAPI). The
+ * rcu_read_lock_bh_held() below makes lockdep accept both.
+ */
static void *__dev_map_hash_lookup_elem(struct bpf_map *map, u32 key)
{
struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
return false;
}
+static int dev_map_bpf_prog_run(struct bpf_prog *xdp_prog,
+ struct xdp_frame **frames, int n,
+ struct net_device *dev)
+{
+ struct xdp_txq_info txq = { .dev = dev };
+ struct xdp_buff xdp;
+ int i, nframes = 0;
+
+ for (i = 0; i < n; i++) {
+ struct xdp_frame *xdpf = frames[i];
+ u32 act;
+ int err;
+
+ xdp_convert_frame_to_buff(xdpf, &xdp);
+ xdp.txq = &txq;
+
+ act = bpf_prog_run_xdp(xdp_prog, &xdp);
+ switch (act) {
+ case XDP_PASS:
+ err = xdp_update_frame_from_buff(&xdp, xdpf);
+ if (unlikely(err < 0))
+ xdp_return_frame_rx_napi(xdpf);
+ else
+ frames[nframes++] = xdpf;
+ break;
+ default:
+ bpf_warn_invalid_xdp_action(act);
+ fallthrough;
+ case XDP_ABORTED:
+ trace_xdp_exception(dev, xdp_prog, act);
+ fallthrough;
+ case XDP_DROP:
+ xdp_return_frame_rx_napi(xdpf);
+ break;
+ }
+ }
+ return nframes; /* sent frames count */
+}
+
static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags)
{
struct net_device *dev = bq->dev;
+ unsigned int cnt = bq->count;
int sent = 0, err = 0;
+ int to_send = cnt;
int i;
- if (unlikely(!bq->count))
+ if (unlikely(!cnt))
return;
- for (i = 0; i < bq->count; i++) {
+ for (i = 0; i < cnt; i++) {
struct xdp_frame *xdpf = bq->q[i];
prefetch(xdpf);
}
- sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, flags);
+ if (bq->xdp_prog) {
+ to_send = dev_map_bpf_prog_run(bq->xdp_prog, bq->q, cnt, dev);
+ if (!to_send)
+ goto out;
+ }
+
+ sent = dev->netdev_ops->ndo_xdp_xmit(dev, to_send, bq->q, flags);
if (sent < 0) {
/* If ndo_xdp_xmit fails with an errno, no frames have
* been xmit'ed.
/* If not all frames have been transmitted, it is our
* responsibility to free them
*/
- for (i = sent; unlikely(i < bq->count); i++)
+ for (i = sent; unlikely(i < to_send); i++)
xdp_return_frame_rx_napi(bq->q[i]);
- trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, bq->count - sent, err);
- bq->dev_rx = NULL;
+out:
bq->count = 0;
- __list_del_clearprev(&bq->flush_node);
-}
-
-/* __dev_flush is called from xdp_do_flush() which _must_ be signaled
- * from the driver before returning from its napi->poll() routine. The poll()
- * routine is called either from busy_poll context or net_rx_action signaled
- * from NET_RX_SOFTIRQ. Either way the poll routine must complete before the
- * net device can be torn down. On devmap tear down we ensure the flush list
- * is empty before completing to ensure all flush operations have completed.
- * When drivers update the bpf program they may need to ensure any flush ops
- * are also complete. Using synchronize_rcu or call_rcu will suffice for this
- * because both wait for napi context to exit.
+ trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, cnt - sent, err);
+}
+
+/* __dev_flush is called from xdp_do_flush() which _must_ be signalled from the
+ * driver before returning from its napi->poll() routine. See the comment above
+ * xdp_do_flush() in filter.c.
*/
void __dev_flush(void)
{
struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
struct xdp_dev_bulk_queue *bq, *tmp;
- list_for_each_entry_safe(bq, tmp, flush_list, flush_node)
+ list_for_each_entry_safe(bq, tmp, flush_list, flush_node) {
bq_xmit_all(bq, XDP_XMIT_FLUSH);
+ bq->dev_rx = NULL;
+ bq->xdp_prog = NULL;
+ __list_del_clearprev(&bq->flush_node);
+ }
}
-/* rcu_read_lock (from syscall and BPF contexts) ensures that if a delete and/or
- * update happens in parallel here a dev_put wont happen until after reading the
- * ifindex.
+/* Elements are kept alive by RCU; either by rcu_read_lock() (from syscall) or
+ * by local_bh_disable() (from XDP calls inside NAPI). The
+ * rcu_read_lock_bh_held() below makes lockdep accept both.
*/
static void *__dev_map_lookup_elem(struct bpf_map *map, u32 key)
{
if (key >= map->max_entries)
return NULL;
- obj = READ_ONCE(dtab->netdev_map[key]);
+ obj = rcu_dereference_check(dtab->netdev_map[key],
+ rcu_read_lock_bh_held());
return obj;
}
-/* Runs under RCU-read-side, plus in softirq under NAPI protection.
- * Thus, safe percpu variable access.
+/* Runs in NAPI, i.e., softirq under local_bh_disable(). Thus, safe percpu
+ * variable access, and map elements stick around. See comment above
+ * xdp_do_flush() in filter.c.
*/
static void bq_enqueue(struct net_device *dev, struct xdp_frame *xdpf,
- struct net_device *dev_rx)
+ struct net_device *dev_rx, struct bpf_prog *xdp_prog)
{
struct list_head *flush_list = this_cpu_ptr(&dev_flush_list);
struct xdp_dev_bulk_queue *bq = this_cpu_ptr(dev->xdp_bulkq);
/* Ingress dev_rx will be the same for all xdp_frame's in
* bulk_queue, because bq stored per-CPU and must be flushed
* from net_device drivers NAPI func end.
+ *
+ * Do the same with xdp_prog and flush_list since these fields
+ * are only ever modified together.
*/
- if (!bq->dev_rx)
+ if (!bq->dev_rx) {
bq->dev_rx = dev_rx;
+ bq->xdp_prog = xdp_prog;
+ list_add(&bq->flush_node, flush_list);
+ }
bq->q[bq->count++] = xdpf;
-
- if (!bq->flush_node.prev)
- list_add(&bq->flush_node, flush_list);
}
static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
- struct net_device *dev_rx)
+ struct net_device *dev_rx,
+ struct bpf_prog *xdp_prog)
{
struct xdp_frame *xdpf;
int err;
if (unlikely(!xdpf))
return -EOVERFLOW;
- bq_enqueue(dev, xdpf, dev_rx);
+ bq_enqueue(dev, xdpf, dev_rx, xdp_prog);
return 0;
}
-static struct xdp_buff *dev_map_run_prog(struct net_device *dev,
- struct xdp_buff *xdp,
- struct bpf_prog *xdp_prog)
+int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
{
- struct xdp_txq_info txq = { .dev = dev };
- u32 act;
+ return __xdp_enqueue(dev, xdp, dev_rx, NULL);
+}
- xdp_set_data_meta_invalid(xdp);
- xdp->txq = &txq;
+int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
+ struct net_device *dev_rx)
+{
+ struct net_device *dev = dst->dev;
- act = bpf_prog_run_xdp(xdp_prog, xdp);
- switch (act) {
- case XDP_PASS:
- return xdp;
- case XDP_DROP:
- break;
- default:
- bpf_warn_invalid_xdp_action(act);
- fallthrough;
- case XDP_ABORTED:
- trace_xdp_exception(dev, xdp_prog, act);
- break;
- }
+ return __xdp_enqueue(dev, xdp, dev_rx, dst->xdp_prog);
+}
- xdp_return_buff(xdp);
- return NULL;
+static bool is_valid_dst(struct bpf_dtab_netdev *obj, struct xdp_buff *xdp,
+ int exclude_ifindex)
+{
+ if (!obj || obj->dev->ifindex == exclude_ifindex ||
+ !obj->dev->netdev_ops->ndo_xdp_xmit)
+ return false;
+
+ if (xdp_ok_fwd_dev(obj->dev, xdp->data_end - xdp->data))
+ return false;
+
+ return true;
}
-int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp,
- struct net_device *dev_rx)
+static int dev_map_enqueue_clone(struct bpf_dtab_netdev *obj,
+ struct net_device *dev_rx,
+ struct xdp_frame *xdpf)
{
- return __xdp_enqueue(dev, xdp, dev_rx);
+ struct xdp_frame *nxdpf;
+
+ nxdpf = xdpf_clone(xdpf);
+ if (!nxdpf)
+ return -ENOMEM;
+
+ bq_enqueue(obj->dev, nxdpf, dev_rx, obj->xdp_prog);
+
+ return 0;
}
-int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp,
- struct net_device *dev_rx)
+int dev_map_enqueue_multi(struct xdp_buff *xdp, struct net_device *dev_rx,
+ struct bpf_map *map, bool exclude_ingress)
{
- struct net_device *dev = dst->dev;
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ int exclude_ifindex = exclude_ingress ? dev_rx->ifindex : 0;
+ struct bpf_dtab_netdev *dst, *last_dst = NULL;
+ struct hlist_head *head;
+ struct xdp_frame *xdpf;
+ unsigned int i;
+ int err;
- if (dst->xdp_prog) {
- xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog);
- if (!xdp)
- return 0;
+ xdpf = xdp_convert_buff_to_frame(xdp);
+ if (unlikely(!xdpf))
+ return -EOVERFLOW;
+
+ if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
+ for (i = 0; i < map->max_entries; i++) {
+ dst = READ_ONCE(dtab->netdev_map[i]);
+ if (!is_valid_dst(dst, xdp, exclude_ifindex))
+ continue;
+
+ /* we only need n-1 clones; last_dst enqueued below */
+ if (!last_dst) {
+ last_dst = dst;
+ continue;
+ }
+
+ err = dev_map_enqueue_clone(last_dst, dev_rx, xdpf);
+ if (err)
+ return err;
+
+ last_dst = dst;
+ }
+ } else { /* BPF_MAP_TYPE_DEVMAP_HASH */
+ for (i = 0; i < dtab->n_buckets; i++) {
+ head = dev_map_index_hash(dtab, i);
+ hlist_for_each_entry_rcu(dst, head, index_hlist,
+ lockdep_is_held(&dtab->index_lock)) {
+ if (!is_valid_dst(dst, xdp, exclude_ifindex))
+ continue;
+
+ /* we only need n-1 clones; last_dst enqueued below */
+ if (!last_dst) {
+ last_dst = dst;
+ continue;
+ }
+
+ err = dev_map_enqueue_clone(last_dst, dev_rx, xdpf);
+ if (err)
+ return err;
+
+ last_dst = dst;
+ }
+ }
}
- return __xdp_enqueue(dev, xdp, dev_rx);
+
+ /* consume the last copy of the frame */
+ if (last_dst)
+ bq_enqueue(last_dst->dev, xdpf, dev_rx, last_dst->xdp_prog);
+ else
+ xdp_return_frame_rx_napi(xdpf); /* dtab is empty */
+
+ return 0;
}
int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb,
return 0;
}
+static int dev_map_redirect_clone(struct bpf_dtab_netdev *dst,
+ struct sk_buff *skb,
+ struct bpf_prog *xdp_prog)
+{
+ struct sk_buff *nskb;
+ int err;
+
+ nskb = skb_clone(skb, GFP_ATOMIC);
+ if (!nskb)
+ return -ENOMEM;
+
+ err = dev_map_generic_redirect(dst, nskb, xdp_prog);
+ if (unlikely(err)) {
+ consume_skb(nskb);
+ return err;
+ }
+
+ return 0;
+}
+
+int dev_map_redirect_multi(struct net_device *dev, struct sk_buff *skb,
+ struct bpf_prog *xdp_prog, struct bpf_map *map,
+ bool exclude_ingress)
+{
+ struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map);
+ int exclude_ifindex = exclude_ingress ? dev->ifindex : 0;
+ struct bpf_dtab_netdev *dst, *last_dst = NULL;
+ struct hlist_head *head;
+ struct hlist_node *next;
+ unsigned int i;
+ int err;
+
+ if (map->map_type == BPF_MAP_TYPE_DEVMAP) {
+ for (i = 0; i < map->max_entries; i++) {
+ dst = READ_ONCE(dtab->netdev_map[i]);
+ if (!dst || dst->dev->ifindex == exclude_ifindex)
+ continue;
+
+ /* we only need n-1 clones; last_dst enqueued below */
+ if (!last_dst) {
+ last_dst = dst;
+ continue;
+ }
+
+ err = dev_map_redirect_clone(last_dst, skb, xdp_prog);
+ if (err)
+ return err;
+
+ last_dst = dst;
+ }
+ } else { /* BPF_MAP_TYPE_DEVMAP_HASH */
+ for (i = 0; i < dtab->n_buckets; i++) {
+ head = dev_map_index_hash(dtab, i);
+ hlist_for_each_entry_safe(dst, next, head, index_hlist) {
+ if (!dst || dst->dev->ifindex == exclude_ifindex)
+ continue;
+
+ /* we only need n-1 clones; last_dst enqueued below */
+ if (!last_dst) {
+ last_dst = dst;
+ continue;
+ }
+
+ err = dev_map_redirect_clone(last_dst, skb, xdp_prog);
+ if (err)
+ return err;
+
+ last_dst = dst;
+ }
+ }
+ }
+
+ /* consume the first skb and return */
+ if (last_dst)
+ return dev_map_generic_redirect(last_dst, skb, xdp_prog);
+
+ /* dtab is empty */
+ consume_skb(skb);
+ return 0;
+}
+
static void *dev_map_lookup_elem(struct bpf_map *map, void *key)
{
struct bpf_dtab_netdev *obj = __dev_map_lookup_elem(map, *(u32 *)key);
if (k >= map->max_entries)
return -EINVAL;
- /* Use call_rcu() here to ensure any rcu critical sections have
- * completed as well as any flush operations because call_rcu
- * will wait for preempt-disable region to complete, NAPI in this
- * context. And additionally, the driver tear down ensures all
- * soft irqs are complete before removing the net device in the
- * case of dev_put equals zero.
- */
- old_dev = xchg(&dtab->netdev_map[k], NULL);
+ old_dev = unrcu_pointer(xchg(&dtab->netdev_map[k], NULL));
if (old_dev)
call_rcu(&old_dev->rcu, __dev_map_entry_free);
return 0;
* Remembering the driver side flush operation will happen before the
* net device is removed.
*/
- old_dev = xchg(&dtab->netdev_map[i], dev);
+ old_dev = unrcu_pointer(xchg(&dtab->netdev_map[i], RCU_INITIALIZER(dev)));
if (old_dev)
call_rcu(&old_dev->rcu, __dev_map_entry_free);
static int dev_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
{
- return __bpf_xdp_redirect_map(map, ifindex, flags, __dev_map_lookup_elem);
+ return __bpf_xdp_redirect_map(map, ifindex, flags,
+ BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS,
+ __dev_map_lookup_elem);
}
static int dev_hash_map_redirect(struct bpf_map *map, u32 ifindex, u64 flags)
{
- return __bpf_xdp_redirect_map(map, ifindex, flags, __dev_map_hash_lookup_elem);
+ return __bpf_xdp_redirect_map(map, ifindex, flags,
+ BPF_F_BROADCAST | BPF_F_EXCLUDE_INGRESS,
+ __dev_map_hash_lookup_elem);
}
static int dev_map_btf_id;
for (i = 0; i < dtab->map.max_entries; i++) {
struct bpf_dtab_netdev *dev, *odev;
- dev = READ_ONCE(dtab->netdev_map[i]);
+ dev = rcu_dereference(dtab->netdev_map[i]);
if (!dev || netdev != dev->dev)
continue;
- odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
+ odev = unrcu_pointer(cmpxchg(&dtab->netdev_map[i], RCU_INITIALIZER(dev), NULL));
if (dev == odev)
call_rcu(&dev->rcu,
__dev_map_entry_free);
projects / platform / kernel / linux-starfive.git / blobdiff