From 4d2bb0bfe8741a8778e0053f31a4e0f0cba80e8b Mon Sep 17 00:00:00 2001 From: Lorenzo Bianconi Date: Mon, 12 Feb 2024 10:50:55 +0100 Subject: xdp: rely on skb pointer reference in do_xdp_generic and netif_receive_generic_xdp Rely on skb pointer reference instead of the skb pointer in do_xdp_generic and netif_receive_generic_xdp routine signatures. This is a preliminary patch to add multi-buff support for xdp running in generic mode where we will need to reallocate the skb to avoid linearization and we will need to make it visible to do_xdp_generic() caller. Acked-by: Jesper Dangaard Brouer Reviewed-by: Toke Hoiland-Jorgensen Signed-off-by: Lorenzo Bianconi Link: https://lore.kernel.org/r/c09415b1f48c8620ef4d76deed35050a7bddf7c2.1707729884.git.lorenzo@kernel.org Signed-off-by: Jakub Kicinski --- drivers/net/tun.c | 4 ++-- include/linux/netdevice.h | 2 +- net/core/dev.c | 16 +++++++++------- 3 files changed, 12 insertions(+), 10 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index b472f2c972d8..bc80fc1d576e 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1926,7 +1926,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, struct tun_file *tfile, rcu_read_lock(); xdp_prog = rcu_dereference(tun->xdp_prog); if (xdp_prog) { - ret = do_xdp_generic(xdp_prog, skb); + ret = do_xdp_generic(xdp_prog, &skb); if (ret != XDP_PASS) { rcu_read_unlock(); local_bh_enable(); @@ -2516,7 +2516,7 @@ build: skb_record_rx_queue(skb, tfile->queue_index); if (skb_xdp) { - ret = do_xdp_generic(xdp_prog, skb); + ret = do_xdp_generic(xdp_prog, &skb); if (ret != XDP_PASS) { ret = 0; goto out; diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 07cefa32eafa..a3f9c95da51e 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -3958,7 +3958,7 @@ static inline void dev_consume_skb_any(struct sk_buff *skb) u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp, struct bpf_prog *xdp_prog); void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog); -int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb); +int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff **pskb); int netif_rx(struct sk_buff *skb); int __netif_rx(struct sk_buff *skb); diff --git a/net/core/dev.c b/net/core/dev.c index e19bdf1421e0..ffeb0e0279fe 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4936,10 +4936,11 @@ u32 bpf_prog_run_generic_xdp(struct sk_buff *skb, struct xdp_buff *xdp, return act; } -static u32 netif_receive_generic_xdp(struct sk_buff *skb, +static u32 netif_receive_generic_xdp(struct sk_buff **pskb, struct xdp_buff *xdp, struct bpf_prog *xdp_prog) { + struct sk_buff *skb = *pskb; u32 act = XDP_DROP; /* Reinjected packets coming from act_mirred or similar should @@ -5020,24 +5021,24 @@ void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog) static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key); -int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb) +int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff **pskb) { if (xdp_prog) { struct xdp_buff xdp; u32 act; int err; - act = netif_receive_generic_xdp(skb, &xdp, xdp_prog); + act = netif_receive_generic_xdp(pskb, &xdp, xdp_prog); if (act != XDP_PASS) { switch (act) { case XDP_REDIRECT: - err = xdp_do_generic_redirect(skb->dev, skb, + err = xdp_do_generic_redirect((*pskb)->dev, *pskb, &xdp, xdp_prog); if (err) goto out_redir; break; case XDP_TX: - generic_xdp_tx(skb, xdp_prog); + generic_xdp_tx(*pskb, xdp_prog); break; } return XDP_DROP; @@ -5045,7 +5046,7 @@ int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb) } return XDP_PASS; out_redir: - kfree_skb_reason(skb, SKB_DROP_REASON_XDP); + kfree_skb_reason(*pskb, SKB_DROP_REASON_XDP); return XDP_DROP; } EXPORT_SYMBOL_GPL(do_xdp_generic); @@ -5368,7 +5369,8 @@ another_round: int ret2; migrate_disable(); - ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb); + ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), + &skb); migrate_enable(); if (ret2 != XDP_PASS) { -- cgit