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| author | John Fastabend <john.fastabend@gmail.com> | 2020-11-16 14:28:06 -0800 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2020-11-18 00:12:34 +0100 |
| commit | 36cd0e696a832a00247fca522034703566ac8885 (patch) | |
| tree | 28849770d1faadc2117ca1fd60799173cf46231d /net | |
| parent | c9c89dcd872ea33327673fcb97398993a1f22736 (diff) | |
| download | linux-36cd0e696a832a00247fca522034703566ac8885.tar.gz linux-36cd0e696a832a00247fca522034703566ac8885.tar.bz2 linux-36cd0e696a832a00247fca522034703566ac8885.zip | |
bpf, sockmap: Ensure SO_RCVBUF memory is observed on ingress redirect
Fix sockmap sk_skb programs so that they observe sk_rcvbuf limits. This
allows users to tune SO_RCVBUF and sockmap will honor them.
We can refactor the if(charge) case out in later patches. But, keep this
fix to the point.
Fixes: 51199405f9672 ("bpf: skb_verdict, support SK_PASS on RX BPF path")
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/160556568657.73229.8404601585878439060.stgit@john-XPS-13-9370
Diffstat (limited to 'net')
| -rw-r--r-- | net/core/skmsg.c | 20 | ||||
| -rw-r--r-- | net/ipv4/tcp_bpf.c | 3 |
2 files changed, 18 insertions, 5 deletions
diff --git a/net/core/skmsg.c b/net/core/skmsg.c index 654182ecf87b..fe44280c033e 100644 --- a/net/core/skmsg.c +++ b/net/core/skmsg.c @@ -170,10 +170,12 @@ static int sk_msg_free_elem(struct sock *sk, struct sk_msg *msg, u32 i, struct scatterlist *sge = sk_msg_elem(msg, i); u32 len = sge->length; - if (charge) - sk_mem_uncharge(sk, len); - if (!msg->skb) + /* When the skb owns the memory we free it from consume_skb path. */ + if (!msg->skb) { + if (charge) + sk_mem_uncharge(sk, len); put_page(sg_page(sge)); + } memset(sge, 0, sizeof(*sge)); return len; } @@ -403,6 +405,9 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) int copied = 0, num_sge; struct sk_msg *msg; + if (atomic_read(&sk->sk_rmem_alloc) > sk->sk_rcvbuf) + return -EAGAIN; + msg = kzalloc(sizeof(*msg), __GFP_NOWARN | GFP_ATOMIC); if (unlikely(!msg)) return -EAGAIN; @@ -418,7 +423,14 @@ static int sk_psock_skb_ingress(struct sk_psock *psock, struct sk_buff *skb) return num_sge; } - sk_mem_charge(sk, skb->len); + /* This will transition ownership of the data from the socket where + * the BPF program was run initiating the redirect to the socket + * we will eventually receive this data on. The data will be released + * from skb_consume found in __tcp_bpf_recvmsg() after its been copied + * into user buffers. + */ + skb_set_owner_r(skb, sk); + copied = skb->len; msg->sg.start = 0; msg->sg.size = copied; diff --git a/net/ipv4/tcp_bpf.c b/net/ipv4/tcp_bpf.c index 8e950b0bfabc..bc7d2a586e18 100644 --- a/net/ipv4/tcp_bpf.c +++ b/net/ipv4/tcp_bpf.c @@ -45,7 +45,8 @@ int __tcp_bpf_recvmsg(struct sock *sk, struct sk_psock *psock, if (likely(!peek)) { sge->offset += copy; sge->length -= copy; - sk_mem_uncharge(sk, copy); + if (!msg_rx->skb) + sk_mem_uncharge(sk, copy); msg_rx->sg.size -= copy; if (!sge->length) { |