[PATCH net-next 06/11] tuntap: split out XDP logic
From: Jason Wang <hidden>
Date: 2018-09-06 04:05:21
Subsystem:
networking drivers, the rest, tun/tap driver · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Willem de Bruijn, Jason Wang
Possibly related (same subject, not in this thread)
- 2018-09-10 · Re: [PATCH net-next 06/11] tuntap: split out XDP logic · Jason Wang <hidden>
- 2018-09-07 · Re: [PATCH net-next 06/11] tuntap: split out XDP logic · "Michael S. Tsirkin" <mst@redhat.com>
- 2018-09-07 · Re: [PATCH net-next 06/11] tuntap: split out XDP logic · Jason Wang <hidden>
- 2018-09-06 · Re: [PATCH net-next 06/11] tuntap: split out XDP logic · "Michael S. Tsirkin" <mst@redhat.com>
This patch split out XDP logic into a single function. This make it to be reused by XDP batching path in the following patch. Signed-off-by: Jason Wang <redacted> --- drivers/net/tun.c | 84 ++++++++++++++++++++++++++++------------------- 1 file changed, 51 insertions(+), 33 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index 389aa0727cc6..21b125020b3b 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c@@ -1635,6 +1635,44 @@ static bool tun_can_build_skb(struct tun_struct *tun, struct tun_file *tfile, return true; } +static u32 tun_do_xdp(struct tun_struct *tun, + struct tun_file *tfile, + struct bpf_prog *xdp_prog, + struct xdp_buff *xdp, + int *err) +{ + u32 act = bpf_prog_run_xdp(xdp_prog, xdp); + + switch (act) { + case XDP_REDIRECT: + *err = xdp_do_redirect(tun->dev, xdp, xdp_prog); + xdp_do_flush_map(); + if (*err) + break; + goto out; + case XDP_TX: + *err = tun_xdp_tx(tun->dev, xdp); + if (*err < 0) + break; + *err = 0; + goto out; + case XDP_PASS: + goto out; + default: + bpf_warn_invalid_xdp_action(act); + /* fall through */ + case XDP_ABORTED: + trace_xdp_exception(tun->dev, xdp_prog, act); + /* fall through */ + case XDP_DROP: + break; + } + + put_page(virt_to_head_page(xdp->data_hard_start)); +out: + return act; +} + static struct sk_buff *tun_build_skb(struct tun_struct *tun, struct tun_file *tfile, struct iov_iter *from,
@@ -1645,10 +1683,10 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, struct sk_buff *skb = NULL; struct bpf_prog *xdp_prog; int buflen = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); - unsigned int delta = 0; char *buf; size_t copied; - int err, pad = TUN_RX_PAD; + int pad = TUN_RX_PAD; + int err = 0; rcu_read_lock(); xdp_prog = rcu_dereference(tun->xdp_prog);
@@ -1685,9 +1723,8 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, local_bh_disable(); rcu_read_lock(); xdp_prog = rcu_dereference(tun->xdp_prog); - if (xdp_prog && !*skb_xdp) { + if (xdp_prog) { struct xdp_buff xdp; - void *orig_data; u32 act; xdp.data_hard_start = buf;
@@ -1695,33 +1732,14 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, xdp_set_data_meta_invalid(&xdp); xdp.data_end = xdp.data + len; xdp.rxq = &tfile->xdp_rxq; - orig_data = xdp.data; - act = bpf_prog_run_xdp(xdp_prog, &xdp); - - switch (act) { - case XDP_REDIRECT: - err = xdp_do_redirect(tun->dev, &xdp, xdp_prog); - xdp_do_flush_map(); - if (err) - goto err_xdp; - goto out; - case XDP_TX: - if (tun_xdp_tx(tun->dev, &xdp) < 0) - goto err_xdp; - goto out; - case XDP_PASS: - delta = orig_data - xdp.data; - len = xdp.data_end - xdp.data; - break; - default: - bpf_warn_invalid_xdp_action(act); - /* fall through */ - case XDP_ABORTED: - trace_xdp_exception(tun->dev, xdp_prog, act); - /* fall through */ - case XDP_DROP: + act = tun_do_xdp(tun, tfile, xdp_prog, &xdp, &err); + if (err) goto err_xdp; - } + if (act != XDP_PASS) + goto out; + + pad = xdp.data - xdp.data_hard_start; + len = xdp.data_end - xdp.data; } rcu_read_unlock(); local_bh_enable();
@@ -1729,18 +1747,18 @@ static struct sk_buff *tun_build_skb(struct tun_struct *tun, build: skb = build_skb(buf, buflen); if (!skb) { + put_page(alloc_frag->page); skb = ERR_PTR(-ENOMEM); goto out; } - skb_reserve(skb, pad - delta); + skb_reserve(skb, pad); skb_put(skb, len); return skb; err_xdp: - alloc_frag->offset -= buflen; - put_page(alloc_frag->page); + this_cpu_inc(tun->pcpu_stats->rx_dropped); out: rcu_read_unlock(); local_bh_enable();
--
2.17.1