[PATCH RESEND bpf v3 6/8] skmsg: teach sk_psock_verdict_apply() to return errors
From: Cong Wang <hidden>
Date: 2021-06-15 02:23:27
Also in:
bpf
Subsystem:
bpf [l7 framework] (sockmap), networking [general], the rest · Maintainers:
John Fastabend, Jakub Sitnicki, Jiayuan Chen, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Cong Wang <redacted>
Currently sk_psock_verdict_apply() is void, but it handles some
error conditions too. Its caller is impossible to learn whether
it succeeds or fails, especially sk_psock_verdict_recv().
Make it return int to indicate error cases and propagate errors
to callers properly.
Fixes: ef5659280eb1 ("bpf, sockmap: Allow skipping sk_skb parser program")
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Cc: Lorenz Bauer <redacted>
Signed-off-by: Cong Wang <redacted>
---
net/core/skmsg.c | 23 ++++++++++++++---------
1 file changed, 14 insertions(+), 9 deletions(-)
diff --git a/net/core/skmsg.c b/net/core/skmsg.c
index 5464477e2d3d..e3d210811db4 100644
--- a/net/core/skmsg.c
+++ b/net/core/skmsg.c@@ -824,7 +824,7 @@ int sk_psock_msg_verdict(struct sock *sk, struct sk_psock *psock, } EXPORT_SYMBOL_GPL(sk_psock_msg_verdict); -static void sk_psock_skb_redirect(struct sk_buff *skb) +static int sk_psock_skb_redirect(struct sk_buff *skb) { struct sk_psock *psock_other; struct sock *sk_other;
@@ -835,7 +835,7 @@ static void sk_psock_skb_redirect(struct sk_buff *skb) */ if (unlikely(!sk_other)) { kfree_skb(skb); - return; + return -EIO; } psock_other = sk_psock(sk_other); /* This error indicates the socket is being torn down or had another
@@ -845,19 +845,20 @@ static void sk_psock_skb_redirect(struct sk_buff *skb) if (!psock_other || sock_flag(sk_other, SOCK_DEAD)) { skb_bpf_redirect_clear(skb); kfree_skb(skb); - return; + return -EIO; } spin_lock_bh(&psock_other->ingress_lock); if (!sk_psock_test_state(psock_other, SK_PSOCK_TX_ENABLED)) { spin_unlock_bh(&psock_other->ingress_lock); skb_bpf_redirect_clear(skb); kfree_skb(skb); - return; + return -EIO; } skb_queue_tail(&psock_other->ingress_skb, skb); schedule_work(&psock_other->work); spin_unlock_bh(&psock_other->ingress_lock); + return 0; } static void sk_psock_tls_verdict_apply(struct sk_buff *skb, struct sock *sk, int verdict)
@@ -894,14 +895,15 @@ int sk_psock_tls_strp_read(struct sk_psock *psock, struct sk_buff *skb) } EXPORT_SYMBOL_GPL(sk_psock_tls_strp_read); -static void sk_psock_verdict_apply(struct sk_psock *psock, - struct sk_buff *skb, int verdict) +static int sk_psock_verdict_apply(struct sk_psock *psock, struct sk_buff *skb, + int verdict) { struct sock *sk_other; - int err = -EIO; + int err = 0; switch (verdict) { case __SK_PASS: + err = -EIO; sk_other = psock->sk; if (sock_flag(sk_other, SOCK_DEAD) || !sk_psock_test_state(psock, SK_PSOCK_TX_ENABLED)) {
@@ -934,13 +936,15 @@ static void sk_psock_verdict_apply(struct sk_psock *psock, } break; case __SK_REDIRECT: - sk_psock_skb_redirect(skb); + err = sk_psock_skb_redirect(skb); break; case __SK_DROP: default: out_free: kfree_skb(skb); } + + return err; } static void sk_psock_write_space(struct sock *sk)
@@ -1107,7 +1111,8 @@ static int sk_psock_verdict_recv(read_descriptor_t *desc, struct sk_buff *skb, ret = sk_psock_map_verd(ret, skb_bpf_redirect_fetch(skb)); skb->sk = NULL; } - sk_psock_verdict_apply(psock, skb, ret); + if (sk_psock_verdict_apply(psock, skb, ret) < 0) + len = 0; out: rcu_read_unlock(); return len;
--
2.25.1