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xdp: rely on skb pointer reference in do_xdp_generic and netif_receive_generic_xdp

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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 <hawk@kernel.org>
Reviewed-by: Toke Hoiland-Jorgensen <toke@redhat.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/c09415b1f48c8620ef4d76deed35050a7bddf7c2.1707729884.git.lorenzo@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Lorenzo Bianconi 2024-02-12 10:50:55 +01:00 committed by Jakub Kicinski
parent 2b0cfa6e49
commit 4d2bb0bfe8
3 changed files with 12 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/net/tun.c
View File

@ -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;

2
include/linux/netdevice.h
View File

@ -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);

16
net/core/dev.c
View File

@ -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) {