mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
68b54aeff8
In the blamed commit below, I completely forgot to release the acquired
resources before erroring out in the TCP BPF code, as reported by Dan.
Address the issues by replacing the bogus return with a jump to the
relevant cleanup code.
Fixes: 419ce133ab
("tcp: allow again tcp_disconnect() when threads are waiting")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Jakub Sitnicki <jakub@cloudflare.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/r/8f99194c698bcef12666f0a9a999c58f8b1cb52c.1697557782.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
701 lines
16 KiB
C
701 lines
16 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2017 - 2018 Covalent IO, Inc. http://covalent.io */
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#include <linux/skmsg.h>
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#include <linux/filter.h>
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#include <linux/bpf.h>
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#include <linux/init.h>
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#include <linux/wait.h>
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#include <linux/util_macros.h>
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#include <net/inet_common.h>
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#include <net/tls.h>
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void tcp_eat_skb(struct sock *sk, struct sk_buff *skb)
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{
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struct tcp_sock *tcp;
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int copied;
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if (!skb || !skb->len || !sk_is_tcp(sk))
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return;
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if (skb_bpf_strparser(skb))
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return;
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tcp = tcp_sk(sk);
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copied = tcp->copied_seq + skb->len;
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WRITE_ONCE(tcp->copied_seq, copied);
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tcp_rcv_space_adjust(sk);
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__tcp_cleanup_rbuf(sk, skb->len);
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}
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static int bpf_tcp_ingress(struct sock *sk, struct sk_psock *psock,
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struct sk_msg *msg, u32 apply_bytes, int flags)
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{
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bool apply = apply_bytes;
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struct scatterlist *sge;
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u32 size, copied = 0;
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struct sk_msg *tmp;
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int i, ret = 0;
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tmp = kzalloc(sizeof(*tmp), __GFP_NOWARN | GFP_KERNEL);
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if (unlikely(!tmp))
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return -ENOMEM;
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lock_sock(sk);
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tmp->sg.start = msg->sg.start;
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i = msg->sg.start;
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do {
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sge = sk_msg_elem(msg, i);
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size = (apply && apply_bytes < sge->length) ?
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apply_bytes : sge->length;
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if (!sk_wmem_schedule(sk, size)) {
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if (!copied)
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ret = -ENOMEM;
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break;
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}
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sk_mem_charge(sk, size);
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sk_msg_xfer(tmp, msg, i, size);
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copied += size;
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if (sge->length)
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get_page(sk_msg_page(tmp, i));
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sk_msg_iter_var_next(i);
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tmp->sg.end = i;
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if (apply) {
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apply_bytes -= size;
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if (!apply_bytes) {
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if (sge->length)
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sk_msg_iter_var_prev(i);
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break;
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}
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}
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} while (i != msg->sg.end);
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if (!ret) {
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msg->sg.start = i;
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sk_psock_queue_msg(psock, tmp);
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sk_psock_data_ready(sk, psock);
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} else {
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sk_msg_free(sk, tmp);
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kfree(tmp);
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}
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release_sock(sk);
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return ret;
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}
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static int tcp_bpf_push(struct sock *sk, struct sk_msg *msg, u32 apply_bytes,
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int flags, bool uncharge)
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{
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struct msghdr msghdr = {};
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bool apply = apply_bytes;
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struct scatterlist *sge;
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struct page *page;
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int size, ret = 0;
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u32 off;
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while (1) {
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struct bio_vec bvec;
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bool has_tx_ulp;
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sge = sk_msg_elem(msg, msg->sg.start);
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size = (apply && apply_bytes < sge->length) ?
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apply_bytes : sge->length;
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off = sge->offset;
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page = sg_page(sge);
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tcp_rate_check_app_limited(sk);
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retry:
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msghdr.msg_flags = flags | MSG_SPLICE_PAGES;
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has_tx_ulp = tls_sw_has_ctx_tx(sk);
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if (has_tx_ulp)
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msghdr.msg_flags |= MSG_SENDPAGE_NOPOLICY;
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if (size < sge->length && msg->sg.start != msg->sg.end)
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msghdr.msg_flags |= MSG_MORE;
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bvec_set_page(&bvec, page, size, off);
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iov_iter_bvec(&msghdr.msg_iter, ITER_SOURCE, &bvec, 1, size);
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ret = tcp_sendmsg_locked(sk, &msghdr, size);
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if (ret <= 0)
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return ret;
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if (apply)
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apply_bytes -= ret;
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msg->sg.size -= ret;
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sge->offset += ret;
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sge->length -= ret;
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if (uncharge)
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sk_mem_uncharge(sk, ret);
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if (ret != size) {
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size -= ret;
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off += ret;
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goto retry;
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}
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if (!sge->length) {
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put_page(page);
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sk_msg_iter_next(msg, start);
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sg_init_table(sge, 1);
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if (msg->sg.start == msg->sg.end)
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break;
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}
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if (apply && !apply_bytes)
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break;
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}
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return 0;
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}
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static int tcp_bpf_push_locked(struct sock *sk, struct sk_msg *msg,
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u32 apply_bytes, int flags, bool uncharge)
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{
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int ret;
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lock_sock(sk);
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ret = tcp_bpf_push(sk, msg, apply_bytes, flags, uncharge);
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release_sock(sk);
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return ret;
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}
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int tcp_bpf_sendmsg_redir(struct sock *sk, bool ingress,
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struct sk_msg *msg, u32 bytes, int flags)
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{
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struct sk_psock *psock = sk_psock_get(sk);
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int ret;
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if (unlikely(!psock))
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return -EPIPE;
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ret = ingress ? bpf_tcp_ingress(sk, psock, msg, bytes, flags) :
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tcp_bpf_push_locked(sk, msg, bytes, flags, false);
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sk_psock_put(sk, psock);
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return ret;
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}
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EXPORT_SYMBOL_GPL(tcp_bpf_sendmsg_redir);
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#ifdef CONFIG_BPF_SYSCALL
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static int tcp_msg_wait_data(struct sock *sk, struct sk_psock *psock,
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long timeo)
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{
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DEFINE_WAIT_FUNC(wait, woken_wake_function);
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int ret = 0;
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if (sk->sk_shutdown & RCV_SHUTDOWN)
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return 1;
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if (!timeo)
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return ret;
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add_wait_queue(sk_sleep(sk), &wait);
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sk_set_bit(SOCKWQ_ASYNC_WAITDATA, sk);
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ret = sk_wait_event(sk, &timeo,
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!list_empty(&psock->ingress_msg) ||
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!skb_queue_empty_lockless(&sk->sk_receive_queue), &wait);
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sk_clear_bit(SOCKWQ_ASYNC_WAITDATA, sk);
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remove_wait_queue(sk_sleep(sk), &wait);
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return ret;
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}
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static bool is_next_msg_fin(struct sk_psock *psock)
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{
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struct scatterlist *sge;
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struct sk_msg *msg_rx;
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int i;
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msg_rx = sk_psock_peek_msg(psock);
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i = msg_rx->sg.start;
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sge = sk_msg_elem(msg_rx, i);
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if (!sge->length) {
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struct sk_buff *skb = msg_rx->skb;
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if (skb && TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN)
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return true;
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}
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return false;
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}
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static int tcp_bpf_recvmsg_parser(struct sock *sk,
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struct msghdr *msg,
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size_t len,
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int flags,
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int *addr_len)
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{
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struct tcp_sock *tcp = tcp_sk(sk);
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int peek = flags & MSG_PEEK;
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u32 seq = tcp->copied_seq;
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struct sk_psock *psock;
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int copied = 0;
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if (unlikely(flags & MSG_ERRQUEUE))
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return inet_recv_error(sk, msg, len, addr_len);
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if (!len)
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return 0;
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psock = sk_psock_get(sk);
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if (unlikely(!psock))
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return tcp_recvmsg(sk, msg, len, flags, addr_len);
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lock_sock(sk);
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/* We may have received data on the sk_receive_queue pre-accept and
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* then we can not use read_skb in this context because we haven't
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* assigned a sk_socket yet so have no link to the ops. The work-around
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* is to check the sk_receive_queue and in these cases read skbs off
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* queue again. The read_skb hook is not running at this point because
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* of lock_sock so we avoid having multiple runners in read_skb.
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*/
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if (unlikely(!skb_queue_empty(&sk->sk_receive_queue))) {
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tcp_data_ready(sk);
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/* This handles the ENOMEM errors if we both receive data
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* pre accept and are already under memory pressure. At least
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* let user know to retry.
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*/
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if (unlikely(!skb_queue_empty(&sk->sk_receive_queue))) {
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copied = -EAGAIN;
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goto out;
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}
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}
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msg_bytes_ready:
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copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
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/* The typical case for EFAULT is the socket was gracefully
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* shutdown with a FIN pkt. So check here the other case is
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* some error on copy_page_to_iter which would be unexpected.
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* On fin return correct return code to zero.
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*/
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if (copied == -EFAULT) {
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bool is_fin = is_next_msg_fin(psock);
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if (is_fin) {
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copied = 0;
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seq++;
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goto out;
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}
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}
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seq += copied;
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if (!copied) {
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long timeo;
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int data;
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if (sock_flag(sk, SOCK_DONE))
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goto out;
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if (sk->sk_err) {
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copied = sock_error(sk);
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goto out;
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}
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if (sk->sk_shutdown & RCV_SHUTDOWN)
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goto out;
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if (sk->sk_state == TCP_CLOSE) {
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copied = -ENOTCONN;
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goto out;
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}
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timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
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if (!timeo) {
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copied = -EAGAIN;
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goto out;
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}
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if (signal_pending(current)) {
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copied = sock_intr_errno(timeo);
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goto out;
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}
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data = tcp_msg_wait_data(sk, psock, timeo);
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if (data < 0) {
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copied = data;
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goto unlock;
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}
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if (data && !sk_psock_queue_empty(psock))
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goto msg_bytes_ready;
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copied = -EAGAIN;
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}
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out:
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if (!peek)
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WRITE_ONCE(tcp->copied_seq, seq);
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tcp_rcv_space_adjust(sk);
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if (copied > 0)
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__tcp_cleanup_rbuf(sk, copied);
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unlock:
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release_sock(sk);
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sk_psock_put(sk, psock);
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return copied;
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}
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static int tcp_bpf_recvmsg(struct sock *sk, struct msghdr *msg, size_t len,
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int flags, int *addr_len)
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{
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struct sk_psock *psock;
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int copied, ret;
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if (unlikely(flags & MSG_ERRQUEUE))
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return inet_recv_error(sk, msg, len, addr_len);
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if (!len)
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return 0;
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psock = sk_psock_get(sk);
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if (unlikely(!psock))
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return tcp_recvmsg(sk, msg, len, flags, addr_len);
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if (!skb_queue_empty(&sk->sk_receive_queue) &&
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sk_psock_queue_empty(psock)) {
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sk_psock_put(sk, psock);
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return tcp_recvmsg(sk, msg, len, flags, addr_len);
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}
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lock_sock(sk);
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msg_bytes_ready:
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copied = sk_msg_recvmsg(sk, psock, msg, len, flags);
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if (!copied) {
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long timeo;
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int data;
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timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
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data = tcp_msg_wait_data(sk, psock, timeo);
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if (data < 0) {
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ret = data;
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goto unlock;
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}
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if (data) {
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if (!sk_psock_queue_empty(psock))
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goto msg_bytes_ready;
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release_sock(sk);
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sk_psock_put(sk, psock);
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return tcp_recvmsg(sk, msg, len, flags, addr_len);
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}
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copied = -EAGAIN;
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}
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ret = copied;
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unlock:
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release_sock(sk);
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sk_psock_put(sk, psock);
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return ret;
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}
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static int tcp_bpf_send_verdict(struct sock *sk, struct sk_psock *psock,
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struct sk_msg *msg, int *copied, int flags)
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{
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bool cork = false, enospc = sk_msg_full(msg), redir_ingress;
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struct sock *sk_redir;
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u32 tosend, origsize, sent, delta = 0;
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u32 eval;
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int ret;
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more_data:
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if (psock->eval == __SK_NONE) {
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/* Track delta in msg size to add/subtract it on SK_DROP from
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* returned to user copied size. This ensures user doesn't
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* get a positive return code with msg_cut_data and SK_DROP
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* verdict.
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*/
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delta = msg->sg.size;
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psock->eval = sk_psock_msg_verdict(sk, psock, msg);
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delta -= msg->sg.size;
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}
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if (msg->cork_bytes &&
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msg->cork_bytes > msg->sg.size && !enospc) {
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psock->cork_bytes = msg->cork_bytes - msg->sg.size;
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if (!psock->cork) {
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psock->cork = kzalloc(sizeof(*psock->cork),
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GFP_ATOMIC | __GFP_NOWARN);
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if (!psock->cork)
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return -ENOMEM;
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}
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memcpy(psock->cork, msg, sizeof(*msg));
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return 0;
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}
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tosend = msg->sg.size;
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if (psock->apply_bytes && psock->apply_bytes < tosend)
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tosend = psock->apply_bytes;
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eval = __SK_NONE;
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switch (psock->eval) {
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case __SK_PASS:
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ret = tcp_bpf_push(sk, msg, tosend, flags, true);
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if (unlikely(ret)) {
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*copied -= sk_msg_free(sk, msg);
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break;
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}
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sk_msg_apply_bytes(psock, tosend);
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break;
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case __SK_REDIRECT:
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redir_ingress = psock->redir_ingress;
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sk_redir = psock->sk_redir;
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sk_msg_apply_bytes(psock, tosend);
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if (!psock->apply_bytes) {
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/* Clean up before releasing the sock lock. */
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eval = psock->eval;
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psock->eval = __SK_NONE;
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psock->sk_redir = NULL;
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}
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if (psock->cork) {
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cork = true;
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psock->cork = NULL;
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}
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sk_msg_return(sk, msg, tosend);
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release_sock(sk);
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origsize = msg->sg.size;
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ret = tcp_bpf_sendmsg_redir(sk_redir, redir_ingress,
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msg, tosend, flags);
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sent = origsize - msg->sg.size;
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if (eval == __SK_REDIRECT)
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sock_put(sk_redir);
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lock_sock(sk);
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if (unlikely(ret < 0)) {
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int free = sk_msg_free_nocharge(sk, msg);
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if (!cork)
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*copied -= free;
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}
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if (cork) {
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sk_msg_free(sk, msg);
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kfree(msg);
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msg = NULL;
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ret = 0;
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}
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break;
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case __SK_DROP:
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default:
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sk_msg_free_partial(sk, msg, tosend);
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sk_msg_apply_bytes(psock, tosend);
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*copied -= (tosend + delta);
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return -EACCES;
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}
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if (likely(!ret)) {
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if (!psock->apply_bytes) {
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psock->eval = __SK_NONE;
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if (psock->sk_redir) {
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sock_put(psock->sk_redir);
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psock->sk_redir = NULL;
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}
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}
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if (msg &&
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msg->sg.data[msg->sg.start].page_link &&
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msg->sg.data[msg->sg.start].length) {
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if (eval == __SK_REDIRECT)
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sk_mem_charge(sk, tosend - sent);
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goto more_data;
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}
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}
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return ret;
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}
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static int tcp_bpf_sendmsg(struct sock *sk, struct msghdr *msg, size_t size)
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{
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struct sk_msg tmp, *msg_tx = NULL;
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int copied = 0, err = 0;
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struct sk_psock *psock;
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long timeo;
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int flags;
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/* Don't let internal flags through */
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flags = (msg->msg_flags & ~MSG_SENDPAGE_DECRYPTED);
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flags |= MSG_NO_SHARED_FRAGS;
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psock = sk_psock_get(sk);
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if (unlikely(!psock))
|
|
return tcp_sendmsg(sk, msg, size);
|
|
|
|
lock_sock(sk);
|
|
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
|
|
while (msg_data_left(msg)) {
|
|
bool enospc = false;
|
|
u32 copy, osize;
|
|
|
|
if (sk->sk_err) {
|
|
err = -sk->sk_err;
|
|
goto out_err;
|
|
}
|
|
|
|
copy = msg_data_left(msg);
|
|
if (!sk_stream_memory_free(sk))
|
|
goto wait_for_sndbuf;
|
|
if (psock->cork) {
|
|
msg_tx = psock->cork;
|
|
} else {
|
|
msg_tx = &tmp;
|
|
sk_msg_init(msg_tx);
|
|
}
|
|
|
|
osize = msg_tx->sg.size;
|
|
err = sk_msg_alloc(sk, msg_tx, msg_tx->sg.size + copy, msg_tx->sg.end - 1);
|
|
if (err) {
|
|
if (err != -ENOSPC)
|
|
goto wait_for_memory;
|
|
enospc = true;
|
|
copy = msg_tx->sg.size - osize;
|
|
}
|
|
|
|
err = sk_msg_memcopy_from_iter(sk, &msg->msg_iter, msg_tx,
|
|
copy);
|
|
if (err < 0) {
|
|
sk_msg_trim(sk, msg_tx, osize);
|
|
goto out_err;
|
|
}
|
|
|
|
copied += copy;
|
|
if (psock->cork_bytes) {
|
|
if (size > psock->cork_bytes)
|
|
psock->cork_bytes = 0;
|
|
else
|
|
psock->cork_bytes -= size;
|
|
if (psock->cork_bytes && !enospc)
|
|
goto out_err;
|
|
/* All cork bytes are accounted, rerun the prog. */
|
|
psock->eval = __SK_NONE;
|
|
psock->cork_bytes = 0;
|
|
}
|
|
|
|
err = tcp_bpf_send_verdict(sk, psock, msg_tx, &copied, flags);
|
|
if (unlikely(err < 0))
|
|
goto out_err;
|
|
continue;
|
|
wait_for_sndbuf:
|
|
set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
|
|
wait_for_memory:
|
|
err = sk_stream_wait_memory(sk, &timeo);
|
|
if (err) {
|
|
if (msg_tx && msg_tx != psock->cork)
|
|
sk_msg_free(sk, msg_tx);
|
|
goto out_err;
|
|
}
|
|
}
|
|
out_err:
|
|
if (err < 0)
|
|
err = sk_stream_error(sk, msg->msg_flags, err);
|
|
release_sock(sk);
|
|
sk_psock_put(sk, psock);
|
|
return copied ? copied : err;
|
|
}
|
|
|
|
enum {
|
|
TCP_BPF_IPV4,
|
|
TCP_BPF_IPV6,
|
|
TCP_BPF_NUM_PROTS,
|
|
};
|
|
|
|
enum {
|
|
TCP_BPF_BASE,
|
|
TCP_BPF_TX,
|
|
TCP_BPF_RX,
|
|
TCP_BPF_TXRX,
|
|
TCP_BPF_NUM_CFGS,
|
|
};
|
|
|
|
static struct proto *tcpv6_prot_saved __read_mostly;
|
|
static DEFINE_SPINLOCK(tcpv6_prot_lock);
|
|
static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS];
|
|
|
|
static void tcp_bpf_rebuild_protos(struct proto prot[TCP_BPF_NUM_CFGS],
|
|
struct proto *base)
|
|
{
|
|
prot[TCP_BPF_BASE] = *base;
|
|
prot[TCP_BPF_BASE].destroy = sock_map_destroy;
|
|
prot[TCP_BPF_BASE].close = sock_map_close;
|
|
prot[TCP_BPF_BASE].recvmsg = tcp_bpf_recvmsg;
|
|
prot[TCP_BPF_BASE].sock_is_readable = sk_msg_is_readable;
|
|
|
|
prot[TCP_BPF_TX] = prot[TCP_BPF_BASE];
|
|
prot[TCP_BPF_TX].sendmsg = tcp_bpf_sendmsg;
|
|
|
|
prot[TCP_BPF_RX] = prot[TCP_BPF_BASE];
|
|
prot[TCP_BPF_RX].recvmsg = tcp_bpf_recvmsg_parser;
|
|
|
|
prot[TCP_BPF_TXRX] = prot[TCP_BPF_TX];
|
|
prot[TCP_BPF_TXRX].recvmsg = tcp_bpf_recvmsg_parser;
|
|
}
|
|
|
|
static void tcp_bpf_check_v6_needs_rebuild(struct proto *ops)
|
|
{
|
|
if (unlikely(ops != smp_load_acquire(&tcpv6_prot_saved))) {
|
|
spin_lock_bh(&tcpv6_prot_lock);
|
|
if (likely(ops != tcpv6_prot_saved)) {
|
|
tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV6], ops);
|
|
smp_store_release(&tcpv6_prot_saved, ops);
|
|
}
|
|
spin_unlock_bh(&tcpv6_prot_lock);
|
|
}
|
|
}
|
|
|
|
static int __init tcp_bpf_v4_build_proto(void)
|
|
{
|
|
tcp_bpf_rebuild_protos(tcp_bpf_prots[TCP_BPF_IPV4], &tcp_prot);
|
|
return 0;
|
|
}
|
|
late_initcall(tcp_bpf_v4_build_proto);
|
|
|
|
static int tcp_bpf_assert_proto_ops(struct proto *ops)
|
|
{
|
|
/* In order to avoid retpoline, we make assumptions when we call
|
|
* into ops if e.g. a psock is not present. Make sure they are
|
|
* indeed valid assumptions.
|
|
*/
|
|
return ops->recvmsg == tcp_recvmsg &&
|
|
ops->sendmsg == tcp_sendmsg ? 0 : -ENOTSUPP;
|
|
}
|
|
|
|
int tcp_bpf_update_proto(struct sock *sk, struct sk_psock *psock, bool restore)
|
|
{
|
|
int family = sk->sk_family == AF_INET6 ? TCP_BPF_IPV6 : TCP_BPF_IPV4;
|
|
int config = psock->progs.msg_parser ? TCP_BPF_TX : TCP_BPF_BASE;
|
|
|
|
if (psock->progs.stream_verdict || psock->progs.skb_verdict) {
|
|
config = (config == TCP_BPF_TX) ? TCP_BPF_TXRX : TCP_BPF_RX;
|
|
}
|
|
|
|
if (restore) {
|
|
if (inet_csk_has_ulp(sk)) {
|
|
/* TLS does not have an unhash proto in SW cases,
|
|
* but we need to ensure we stop using the sock_map
|
|
* unhash routine because the associated psock is being
|
|
* removed. So use the original unhash handler.
|
|
*/
|
|
WRITE_ONCE(sk->sk_prot->unhash, psock->saved_unhash);
|
|
tcp_update_ulp(sk, psock->sk_proto, psock->saved_write_space);
|
|
} else {
|
|
sk->sk_write_space = psock->saved_write_space;
|
|
/* Pairs with lockless read in sk_clone_lock() */
|
|
sock_replace_proto(sk, psock->sk_proto);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
if (sk->sk_family == AF_INET6) {
|
|
if (tcp_bpf_assert_proto_ops(psock->sk_proto))
|
|
return -EINVAL;
|
|
|
|
tcp_bpf_check_v6_needs_rebuild(psock->sk_proto);
|
|
}
|
|
|
|
/* Pairs with lockless read in sk_clone_lock() */
|
|
sock_replace_proto(sk, &tcp_bpf_prots[family][config]);
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(tcp_bpf_update_proto);
|
|
|
|
/* If a child got cloned from a listening socket that had tcp_bpf
|
|
* protocol callbacks installed, we need to restore the callbacks to
|
|
* the default ones because the child does not inherit the psock state
|
|
* that tcp_bpf callbacks expect.
|
|
*/
|
|
void tcp_bpf_clone(const struct sock *sk, struct sock *newsk)
|
|
{
|
|
struct proto *prot = newsk->sk_prot;
|
|
|
|
if (is_insidevar(prot, tcp_bpf_prots))
|
|
newsk->sk_prot = sk->sk_prot_creator;
|
|
}
|
|
#endif /* CONFIG_BPF_SYSCALL */
|