diff options
| -rw-r--r-- | net/core/dev.c | 208 |
1 files changed, 113 insertions, 95 deletions
diff --git a/net/core/dev.c b/net/core/dev.c index 02440518dd69..a1ed7b41b3e8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3865,6 +3865,107 @@ drop: return NET_RX_DROP; } +static u32 netif_receive_generic_xdp(struct sk_buff *skb, + struct bpf_prog *xdp_prog) +{ + struct xdp_buff xdp; + u32 act = XDP_DROP; + void *orig_data; + int hlen, off; + u32 mac_len; + + /* Reinjected packets coming from act_mirred or similar should + * not get XDP generic processing. + */ + if (skb_cloned(skb)) + return XDP_PASS; + + if (skb_linearize(skb)) + goto do_drop; + + /* The XDP program wants to see the packet starting at the MAC + * header. + */ + mac_len = skb->data - skb_mac_header(skb); + hlen = skb_headlen(skb) + mac_len; + xdp.data = skb->data - mac_len; + xdp.data_end = xdp.data + hlen; + xdp.data_hard_start = skb->data - skb_headroom(skb); + orig_data = xdp.data; + + act = bpf_prog_run_xdp(xdp_prog, &xdp); + + off = xdp.data - orig_data; + if (off > 0) + __skb_pull(skb, off); + else if (off < 0) + __skb_push(skb, -off); + + switch (act) { + case XDP_TX: + __skb_push(skb, mac_len); + /* fall through */ + case XDP_PASS: + break; + + default: + bpf_warn_invalid_xdp_action(act); + /* fall through */ + case XDP_ABORTED: + trace_xdp_exception(skb->dev, xdp_prog, act); + /* fall through */ + case XDP_DROP: + do_drop: + kfree_skb(skb); + break; + } + + return act; +} + +/* When doing generic XDP we have to bypass the qdisc layer and the + * network taps in order to match in-driver-XDP behavior. + */ +static void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) +{ + struct net_device *dev = skb->dev; + struct netdev_queue *txq; + bool free_skb = true; + int cpu, rc; + + txq = netdev_pick_tx(dev, skb, NULL); + cpu = smp_processor_id(); + HARD_TX_LOCK(dev, txq, cpu); + if (!netif_xmit_stopped(txq)) { + rc = netdev_start_xmit(skb, dev, txq, 0); + if (dev_xmit_complete(rc)) + free_skb = false; + } + HARD_TX_UNLOCK(dev, txq); + if (free_skb) { + trace_xdp_exception(dev, xdp_prog, XDP_TX); + kfree_skb(skb); + } +} + +static struct static_key generic_xdp_needed __read_mostly; + +static int do_xdp_generic(struct sk_buff *skb) +{ + struct bpf_prog *xdp_prog = rcu_dereference(skb->dev->xdp_prog); + + if (xdp_prog) { + u32 act = netif_receive_generic_xdp(skb, xdp_prog); + + if (act != XDP_PASS) { + if (act == XDP_TX) + generic_xdp_tx(skb, xdp_prog); + return XDP_DROP; + } + } + return XDP_PASS; +} + static int netif_rx_internal(struct sk_buff *skb) { int ret; @@ -3872,6 +3973,14 @@ static int netif_rx_internal(struct sk_buff *skb) net_timestamp_check(netdev_tstamp_prequeue, skb); trace_netif_rx(skb); + + if (static_key_false(&generic_xdp_needed)) { + int ret = do_xdp_generic(skb); + + if (ret != XDP_PASS) + return NET_RX_DROP; + } + #ifdef CONFIG_RPS if (static_key_false(&rps_needed)) { struct rps_dev_flow voidflow, *rflow = &voidflow; @@ -4338,8 +4447,6 @@ static int __netif_receive_skb(struct sk_buff *skb) return ret; } -static struct static_key generic_xdp_needed __read_mostly; - static int generic_xdp_install(struct net_device *dev, struct netdev_xdp *xdp) { struct bpf_prog *old = rtnl_dereference(dev->xdp_prog); @@ -4373,89 +4480,6 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_xdp *xdp) return ret; } -static u32 netif_receive_generic_xdp(struct sk_buff *skb, - struct bpf_prog *xdp_prog) -{ - struct xdp_buff xdp; - u32 act = XDP_DROP; - void *orig_data; - int hlen, off; - u32 mac_len; - - /* Reinjected packets coming from act_mirred or similar should - * not get XDP generic processing. - */ - if (skb_cloned(skb)) - return XDP_PASS; - - if (skb_linearize(skb)) - goto do_drop; - - /* The XDP program wants to see the packet starting at the MAC - * header. - */ - mac_len = skb->data - skb_mac_header(skb); - hlen = skb_headlen(skb) + mac_len; - xdp.data = skb->data - mac_len; - xdp.data_end = xdp.data + hlen; - xdp.data_hard_start = skb->data - skb_headroom(skb); - orig_data = xdp.data; - - act = bpf_prog_run_xdp(xdp_prog, &xdp); - - off = xdp.data - orig_data; - if (off > 0) - __skb_pull(skb, off); - else if (off < 0) - __skb_push(skb, -off); - - switch (act) { - case XDP_TX: - __skb_push(skb, mac_len); - /* fall through */ - case XDP_PASS: - break; - - default: - bpf_warn_invalid_xdp_action(act); - /* fall through */ - case XDP_ABORTED: - trace_xdp_exception(skb->dev, xdp_prog, act); - /* fall through */ - case XDP_DROP: - do_drop: - kfree_skb(skb); - break; - } - - return act; -} - -/* When doing generic XDP we have to bypass the qdisc layer and the - * network taps in order to match in-driver-XDP behavior. - */ -static void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) -{ - struct net_device *dev = skb->dev; - struct netdev_queue *txq; - bool free_skb = true; - int cpu, rc; - - txq = netdev_pick_tx(dev, skb, NULL); - cpu = smp_processor_id(); - HARD_TX_LOCK(dev, txq, cpu); - if (!netif_xmit_stopped(txq)) { - rc = netdev_start_xmit(skb, dev, txq, 0); - if (dev_xmit_complete(rc)) - free_skb = false; - } - HARD_TX_UNLOCK(dev, txq); - if (free_skb) { - trace_xdp_exception(dev, xdp_prog, XDP_TX); - kfree_skb(skb); - } -} - static int netif_receive_skb_internal(struct sk_buff *skb) { int ret; @@ -4468,17 +4492,11 @@ static int netif_receive_skb_internal(struct sk_buff *skb) rcu_read_lock(); if (static_key_false(&generic_xdp_needed)) { - struct bpf_prog *xdp_prog = rcu_dereference(skb->dev->xdp_prog); - - if (xdp_prog) { - u32 act = netif_receive_generic_xdp(skb, xdp_prog); + int ret = do_xdp_generic(skb); - if (act != XDP_PASS) { - rcu_read_unlock(); - if (act == XDP_TX) - generic_xdp_tx(skb, xdp_prog); - return NET_RX_DROP; - } + if (ret != XDP_PASS) { + rcu_read_unlock(); + return NET_RX_DROP; } } |