lkml.org 
[lkml]   [2022]   [Jun]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH net-next v3 5/9] net: tcp: make tcp_rcv_state_process() return drop reason
    Date
    From: Menglong Dong <imagedong@tencent.com>

    For now, the return value of tcp_rcv_state_process() is treated as bool.
    Therefore, we can make it return the reasons of the skb drops.

    Meanwhile, the return value of tcp_child_process() comes from
    tcp_rcv_state_process(), make it drop reasons by the way.

    The new drop reason SKB_DROP_REASON_TCP_LINGER is added for skb dropping
    out of TCP linger.

    Reviewed-by: Jiang Biao <benbjiang@tencent.com>
    Reviewed-by: Hao Peng <flyingpeng@tencent.com>
    Signed-off-by: Menglong Dong <imagedong@tencent.com>
    v3:
    - instead SKB_DROP_REASON_TCP_ABORTONDATA with SKB_DROP_REASON_TCP_LINGER
    ---
    include/net/dropreason.h | 6 ++++++
    include/net/tcp.h | 8 +++++---
    net/ipv4/tcp_input.c | 36 ++++++++++++++++++++----------------
    net/ipv4/tcp_ipv4.c | 20 +++++++++++++-------
    net/ipv4/tcp_minisocks.c | 11 ++++++-----
    net/ipv6/tcp_ipv6.c | 19 ++++++++++++-------
    6 files changed, 62 insertions(+), 38 deletions(-)

    diff --git a/include/net/dropreason.h b/include/net/dropreason.h
    index c60913aba0e9..bbbf70ce207d 100644
    --- a/include/net/dropreason.h
    +++ b/include/net/dropreason.h
    @@ -242,6 +242,12 @@ enum skb_drop_reason {
    * LINUX_MIB_PAWSACTIVEREJECTED
    */
    SKB_DROP_REASON_TCP_PAWSACTIVEREJECTED,
    + /**
    + * @SKB_DROP_REASON_TCP_LINGER: dropped because of the setting of
    + * TCP socket option TCP_LINGER2, corresponding to
    + * LINUX_MIB_TCPABORTONLINGER
    + */
    + SKB_DROP_REASON_TCP_LINGER,
    /**
    * @SKB_DROP_REASON_MAX: the maximum of drop reason, which shouldn't be
    * used as a real 'reason'
    diff --git a/include/net/tcp.h b/include/net/tcp.h
    index 1e99f5c61f84..ea0eb2d4a743 100644
    --- a/include/net/tcp.h
    +++ b/include/net/tcp.h
    @@ -339,7 +339,8 @@ void tcp_wfree(struct sk_buff *skb);
    void tcp_write_timer_handler(struct sock *sk);
    void tcp_delack_timer_handler(struct sock *sk);
    int tcp_ioctl(struct sock *sk, int cmd, unsigned long arg);
    -int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb);
    +enum skb_drop_reason tcp_rcv_state_process(struct sock *sk,
    + struct sk_buff *skb);
    void tcp_rcv_established(struct sock *sk, struct sk_buff *skb);
    void tcp_rcv_space_adjust(struct sock *sk);
    int tcp_twsk_unique(struct sock *sk, struct sock *sktw, void *twp);
    @@ -385,8 +386,9 @@ enum tcp_tw_status tcp_timewait_state_process(struct inet_timewait_sock *tw,
    struct sock *tcp_check_req(struct sock *sk, struct sk_buff *skb,
    struct request_sock *req, bool fastopen,
    bool *lost_race);
    -int tcp_child_process(struct sock *parent, struct sock *child,
    - struct sk_buff *skb);
    +enum skb_drop_reason tcp_child_process(struct sock *parent,
    + struct sock *child,
    + struct sk_buff *skb);
    void tcp_enter_loss(struct sock *sk);
    void tcp_cwnd_reduction(struct sock *sk, int newly_acked_sacked, int newly_lost, int flag);
    void tcp_clear_retrans(struct tcp_sock *tp);
    diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
    index 9254f14def43..4a6a93d83866 100644
    --- a/net/ipv4/tcp_input.c
    +++ b/net/ipv4/tcp_input.c
    @@ -6425,13 +6425,13 @@ static void tcp_rcv_synrecv_state_fastopen(struct sock *sk)
    * address independent.
    */

    -int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    +enum skb_drop_reason tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    {
    struct tcp_sock *tp = tcp_sk(sk);
    struct inet_connection_sock *icsk = inet_csk(sk);
    const struct tcphdr *th = tcp_hdr(skb);
    struct request_sock *req;
    - int queued = 0;
    + int queued = 0, ret;
    bool acceptable;
    SKB_DR(reason);

    @@ -6442,7 +6442,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)

    case TCP_LISTEN:
    if (th->ack)
    - return 1;
    + return SKB_DROP_REASON_TCP_FLAGS;

    if (th->rst) {
    SKB_DR_SET(reason, TCP_RESET);
    @@ -6463,9 +6463,9 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    rcu_read_unlock();

    if (!acceptable)
    - return 1;
    + return SKB_DROP_REASON_NOT_SPECIFIED;
    consume_skb(skb);
    - return 0;
    + return SKB_NOT_DROPPED_YET;
    }
    SKB_DR_SET(reason, TCP_FLAGS);
    goto discard;
    @@ -6475,13 +6475,13 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    tcp_mstamp_refresh(tp);
    queued = tcp_rcv_synsent_state_process(sk, skb, th);
    if (queued >= 0)
    - return queued;
    + return (enum skb_drop_reason)queued;

    /* Do step6 onward by hand. */
    tcp_urg(sk, skb, th);
    __kfree_skb(skb);
    tcp_data_snd_check(sk);
    - return 0;
    + return SKB_NOT_DROPPED_YET;
    }

    tcp_mstamp_refresh(tp);
    @@ -6508,15 +6508,19 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    return 0;

    /* step 5: check the ACK field */
    - acceptable = tcp_ack(sk, skb, FLAG_SLOWPATH |
    - FLAG_UPDATE_TS_RECENT |
    - FLAG_NO_CHALLENGE_ACK) > 0;
    + ret = tcp_ack(sk, skb, FLAG_SLOWPATH |
    + FLAG_UPDATE_TS_RECENT |
    + FLAG_NO_CHALLENGE_ACK);
    + acceptable = ret > 0;

    if (!acceptable) {
    if (sk->sk_state == TCP_SYN_RECV)
    return 1; /* send one RST */
    tcp_send_challenge_ack(sk);
    - SKB_DR_SET(reason, TCP_OLD_ACK);
    + if (ret == 0)
    + SKB_DR_SET(reason, TCP_OLD_ACK);
    + else
    + reason = -ret;
    goto discard;
    }
    switch (sk->sk_state) {
    @@ -6585,7 +6589,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    if (tp->linger2 < 0) {
    tcp_done(sk);
    NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
    - return 1;
    + return SKB_DROP_REASON_TCP_LINGER;
    }
    if (TCP_SKB_CB(skb)->end_seq != TCP_SKB_CB(skb)->seq &&
    after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) {
    @@ -6594,7 +6598,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    tcp_fastopen_active_disable(sk);
    tcp_done(sk);
    NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
    - return 1;
    + return SKB_DROP_REASON_TCP_INVALID_SEQUENCE;
    }

    tmo = tcp_fin_time(sk);
    @@ -6659,7 +6663,7 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    after(TCP_SKB_CB(skb)->end_seq - th->fin, tp->rcv_nxt)) {
    NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPABORTONDATA);
    tcp_reset(sk, skb);
    - return 1;
    + return SKB_DROP_REASON_TCP_INVALID_SEQUENCE;
    }
    }
    fallthrough;
    @@ -6679,11 +6683,11 @@ int tcp_rcv_state_process(struct sock *sk, struct sk_buff *skb)
    discard:
    tcp_drop_reason(sk, skb, reason);
    }
    - return 0;
    + return SKB_NOT_DROPPED_YET;

    consume:
    __kfree_skb(skb);
    - return 0;
    + return SKB_NOT_DROPPED_YET;
    }
    EXPORT_SYMBOL(tcp_rcv_state_process);

    diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
    index fe8f23b95d32..7bd35ce48b01 100644
    --- a/net/ipv4/tcp_ipv4.c
    +++ b/net/ipv4/tcp_ipv4.c
    @@ -1670,7 +1670,8 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
    if (!nsk)
    goto discard;
    if (nsk != sk) {
    - if (tcp_child_process(sk, nsk, skb)) {
    + reason = tcp_child_process(sk, nsk, skb);
    + if (reason) {
    rsk = nsk;
    goto reset;
    }
    @@ -1679,7 +1680,8 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
    } else
    sock_rps_save_rxhash(sk, skb);

    - if (tcp_rcv_state_process(sk, skb)) {
    + reason = tcp_rcv_state_process(sk, skb);
    + if (reason) {
    rsk = sk;
    goto reset;
    }
    @@ -1688,6 +1690,7 @@ int tcp_v4_do_rcv(struct sock *sk, struct sk_buff *skb)
    reset:
    tcp_v4_send_reset(rsk, skb);
    discard:
    + SKB_DR_OR(reason, NOT_SPECIFIED);
    kfree_skb_reason(skb, reason);
    /* Be careful here. If this function gets more complicated and
    * gcc suffers from register pressure on the x86, sk (in %ebx)
    @@ -2019,12 +2022,15 @@ int tcp_v4_rcv(struct sk_buff *skb)
    if (nsk == sk) {
    reqsk_put(req);
    tcp_v4_restore_cb(skb);
    - } else if (tcp_child_process(sk, nsk, skb)) {
    - tcp_v4_send_reset(nsk, skb);
    - goto discard_and_relse;
    } else {
    - sock_put(sk);
    - return 0;
    + drop_reason = tcp_child_process(sk, nsk, skb);
    + if (drop_reason) {
    + tcp_v4_send_reset(nsk, skb);
    + goto discard_and_relse;
    + } else {
    + sock_put(sk);
    + return 0;
    + }
    }
    }

    diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c
    index 6854bb1fb32b..1a21018f6f64 100644
    --- a/net/ipv4/tcp_minisocks.c
    +++ b/net/ipv4/tcp_minisocks.c
    @@ -821,11 +821,12 @@ EXPORT_SYMBOL(tcp_check_req);
    * be created.
    */

    -int tcp_child_process(struct sock *parent, struct sock *child,
    - struct sk_buff *skb)
    +enum skb_drop_reason tcp_child_process(struct sock *parent,
    + struct sock *child,
    + struct sk_buff *skb)
    __releases(&((child)->sk_lock.slock))
    {
    - int ret = 0;
    + enum skb_drop_reason reason = SKB_NOT_DROPPED_YET;
    int state = child->sk_state;

    /* record sk_napi_id and sk_rx_queue_mapping of child. */
    @@ -833,7 +834,7 @@ int tcp_child_process(struct sock *parent, struct sock *child,

    tcp_segs_in(tcp_sk(child), skb);
    if (!sock_owned_by_user(child)) {
    - ret = tcp_rcv_state_process(child, skb);
    + reason = tcp_rcv_state_process(child, skb);
    /* Wakeup parent, send SIGIO */
    if (state == TCP_SYN_RECV && child->sk_state != state)
    parent->sk_data_ready(parent);
    @@ -847,6 +848,6 @@ int tcp_child_process(struct sock *parent, struct sock *child,

    bh_unlock_sock(child);
    sock_put(child);
    - return ret;
    + return reason;
    }
    EXPORT_SYMBOL(tcp_child_process);
    diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
    index f37dd4aa91c6..49c640b0cea3 100644
    --- a/net/ipv6/tcp_ipv6.c
    +++ b/net/ipv6/tcp_ipv6.c
    @@ -1489,7 +1489,8 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
    goto discard;

    if (nsk != sk) {
    - if (tcp_child_process(sk, nsk, skb))
    + reason = tcp_child_process(sk, nsk, skb);
    + if (reason)
    goto reset;
    if (opt_skb)
    __kfree_skb(opt_skb);
    @@ -1498,7 +1499,8 @@ int tcp_v6_do_rcv(struct sock *sk, struct sk_buff *skb)
    } else
    sock_rps_save_rxhash(sk, skb);

    - if (tcp_rcv_state_process(sk, skb))
    + reason = tcp_rcv_state_process(sk, skb);
    + if (reason)
    goto reset;
    if (opt_skb)
    goto ipv6_pktoptions;
    @@ -1684,12 +1686,15 @@ INDIRECT_CALLABLE_SCOPE int tcp_v6_rcv(struct sk_buff *skb)
    if (nsk == sk) {
    reqsk_put(req);
    tcp_v6_restore_cb(skb);
    - } else if (tcp_child_process(sk, nsk, skb)) {
    - tcp_v6_send_reset(nsk, skb);
    - goto discard_and_relse;
    } else {
    - sock_put(sk);
    - return 0;
    + drop_reason = tcp_child_process(sk, nsk, skb);
    + if (drop_reason) {
    + tcp_v6_send_reset(nsk, skb);
    + goto discard_and_relse;
    + } else {
    + sock_put(sk);
    + return 0;
    + }
    }
    }

    --
    2.36.1
    \
     
     \ /
      Last update: 2022-06-10 05:46    [W:6.070 / U:0.036 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site