Google Git
Sign in
android-kvm / linux / 224b744abf9f0663ca6762a79c7298b663fa4f04 / . / net / rxrpc / input.c
blob: bdf70b81addc497172e55f103d09751ac8a24706 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
/* RxRPC packet reception
*
* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include "ar-internal.h"
static void rxrpc_proto_abort(const char *why,
struct rxrpc_call *call, rxrpc_seq_t seq)
{
if (rxrpc_abort_call(why, call, seq, RX_PROTOCOL_ERROR, -EBADMSG)) {
set_bit(RXRPC_CALL_EV_ABORT, &call->events);
rxrpc_queue_call(call);
}
}
/*
* Do TCP-style congestion management [RFC 5681].
*/
static void rxrpc_congestion_management(struct rxrpc_call *call,
struct sk_buff *skb,
struct rxrpc_ack_summary *summary,
rxrpc_serial_t acked_serial)
{
enum rxrpc_congest_change change = rxrpc_cong_no_change;
unsigned int cumulative_acks = call->cong_cumul_acks;
unsigned int cwnd = call->cong_cwnd;
bool resend = false;
summary->flight_size =
(call->tx_top - call->acks_hard_ack) - summary->nr_acks;
if (test_and_clear_bit(RXRPC_CALL_RETRANS_TIMEOUT, &call->flags)) {
summary->retrans_timeo = true;
call->cong_ssthresh = max_t(unsigned int,
summary->flight_size / 2, 2);
cwnd = 1;
if (cwnd >= call->cong_ssthresh &&
call->cong_mode == RXRPC_CALL_SLOW_START) {
call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
call->cong_tstamp = skb->tstamp;
cumulative_acks = 0;
}
}
cumulative_acks += summary->nr_new_acks;
cumulative_acks += summary->nr_rot_new_acks;
if (cumulative_acks > 255)
cumulative_acks = 255;
summary->mode = call->cong_mode;
summary->cwnd = call->cong_cwnd;
summary->ssthresh = call->cong_ssthresh;
summary->cumulative_acks = cumulative_acks;
summary->dup_acks = call->cong_dup_acks;
/* If we haven't transmitted anything for >1RTT, we should reset the
* congestion management state.
*/
if ((call->cong_mode == RXRPC_CALL_SLOW_START ||
call->cong_mode == RXRPC_CALL_CONGEST_AVOIDANCE) &&
ktime_before(ktime_add_us(call->tx_last_sent,
call->peer->srtt_us >> 3),
ktime_get_real())
) {
change = rxrpc_cong_idle_reset;
summary->mode = RXRPC_CALL_SLOW_START;
if (RXRPC_TX_SMSS > 2190)
summary->cwnd = 2;
else if (RXRPC_TX_SMSS > 1095)
summary->cwnd = 3;
else
summary->cwnd = 4;
}
switch (call->cong_mode) {
case RXRPC_CALL_SLOW_START:
if (summary->saw_nacks)
goto packet_loss_detected;
if (summary->cumulative_acks > 0)
cwnd += 1;
if (cwnd >= call->cong_ssthresh) {
call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
call->cong_tstamp = skb->tstamp;
}
goto out;
case RXRPC_CALL_CONGEST_AVOIDANCE:
if (summary->saw_nacks)
goto packet_loss_detected;
/* We analyse the number of packets that get ACK'd per RTT
* period and increase the window if we managed to fill it.
*/
if (call->peer->rtt_count == 0)
goto out;
if (ktime_before(skb->tstamp,
ktime_add_us(call->cong_tstamp,
call->peer->srtt_us >> 3)))
goto out_no_clear_ca;
change = rxrpc_cong_rtt_window_end;
call->cong_tstamp = skb->tstamp;
if (cumulative_acks >= cwnd)
cwnd++;
goto out;
case RXRPC_CALL_PACKET_LOSS:
if (!summary->saw_nacks)
goto resume_normality;
if (summary->new_low_nack) {
change = rxrpc_cong_new_low_nack;
call->cong_dup_acks = 1;
if (call->cong_extra > 1)
call->cong_extra = 1;
goto send_extra_data;
}
call->cong_dup_acks++;
if (call->cong_dup_acks < 3)
goto send_extra_data;
change = rxrpc_cong_begin_retransmission;
call->cong_mode = RXRPC_CALL_FAST_RETRANSMIT;
call->cong_ssthresh = max_t(unsigned int,
summary->flight_size / 2, 2);
cwnd = call->cong_ssthresh + 3;
call->cong_extra = 0;
call->cong_dup_acks = 0;
resend = true;
goto out;
case RXRPC_CALL_FAST_RETRANSMIT:
if (!summary->new_low_nack) {
if (summary->nr_new_acks == 0)
cwnd += 1;
call->cong_dup_acks++;
if (call->cong_dup_acks == 2) {
change = rxrpc_cong_retransmit_again;
call->cong_dup_acks = 0;
resend = true;
}
} else {
change = rxrpc_cong_progress;
cwnd = call->cong_ssthresh;
if (!summary->saw_nacks)
goto resume_normality;
}
goto out;
default:
BUG();
goto out;
}
resume_normality:
change = rxrpc_cong_cleared_nacks;
call->cong_dup_acks = 0;
call->cong_extra = 0;
call->cong_tstamp = skb->tstamp;
if (cwnd < call->cong_ssthresh)
call->cong_mode = RXRPC_CALL_SLOW_START;
else
call->cong_mode = RXRPC_CALL_CONGEST_AVOIDANCE;
out:
cumulative_acks = 0;
out_no_clear_ca:
if (cwnd >= RXRPC_TX_MAX_WINDOW)
cwnd = RXRPC_TX_MAX_WINDOW;
call->cong_cwnd = cwnd;
call->cong_cumul_acks = cumulative_acks;
trace_rxrpc_congest(call, summary, acked_serial, change);
if (resend && !test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
rxrpc_queue_call(call);
return;
packet_loss_detected:
change = rxrpc_cong_saw_nack;
call->cong_mode = RXRPC_CALL_PACKET_LOSS;
call->cong_dup_acks = 0;
goto send_extra_data;
send_extra_data:
/* Send some previously unsent DATA if we have some to advance the ACK
* state.
*/
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ||
summary->nr_acks != call->tx_top - call->acks_hard_ack) {
call->cong_extra++;
wake_up(&call->waitq);
}
goto out_no_clear_ca;
}
/*
* Apply a hard ACK by advancing the Tx window.
*/
static bool rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
struct rxrpc_ack_summary *summary)
{
struct rxrpc_txbuf *txb;
bool rot_last = false;
list_for_each_entry_rcu(txb, &call->tx_buffer, call_link, false) {
if (before_eq(txb->seq, call->acks_hard_ack))
continue;
summary->nr_rot_new_acks++;
if (test_bit(RXRPC_TXBUF_LAST, &txb->flags)) {
set_bit(RXRPC_CALL_TX_LAST, &call->flags);
rot_last = true;
}
if (txb->seq == to)
break;
}
if (rot_last)
set_bit(RXRPC_CALL_TX_ALL_ACKED, &call->flags);
_enter("%x,%x,%x,%d", to, call->acks_hard_ack, call->tx_top, rot_last);
if (call->acks_lowest_nak == call->acks_hard_ack) {
call->acks_lowest_nak = to;
} else if (after(to, call->acks_lowest_nak)) {
summary->new_low_nack = true;
call->acks_lowest_nak = to;
}
smp_store_release(&call->acks_hard_ack, to);
trace_rxrpc_txqueue(call, (rot_last ?
rxrpc_txqueue_rotate_last :
rxrpc_txqueue_rotate));
wake_up(&call->waitq);
return rot_last;
}
/*
* End the transmission phase of a call.
*
* This occurs when we get an ACKALL packet, the first DATA packet of a reply,
* or a final ACK packet.
*/
static bool rxrpc_end_tx_phase(struct rxrpc_call *call, bool reply_begun,
const char *abort_why)
{
unsigned int state;
ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
write_lock(&call->state_lock);
state = call->state;
switch (state) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
if (reply_begun)
call->state = state = RXRPC_CALL_CLIENT_RECV_REPLY;
else
call->state = state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
break;
case RXRPC_CALL_SERVER_AWAIT_ACK:
__rxrpc_call_completed(call);
state = call->state;
break;
default:
goto bad_state;
}
write_unlock(&call->state_lock);
if (state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
trace_rxrpc_txqueue(call, rxrpc_txqueue_await_reply);
else
trace_rxrpc_txqueue(call, rxrpc_txqueue_end);
_leave(" = ok");
return true;
bad_state:
write_unlock(&call->state_lock);
kdebug("end_tx %s", rxrpc_call_states[call->state]);
rxrpc_proto_abort(abort_why, call, call->tx_top);
return false;
}
/*
* Begin the reply reception phase of a call.
*/
static bool rxrpc_receiving_reply(struct rxrpc_call *call)
{
struct rxrpc_ack_summary summary = { 0 };
unsigned long now, timo;
rxrpc_seq_t top = READ_ONCE(call->tx_top);
if (call->ackr_reason) {
now = jiffies;
timo = now + MAX_JIFFY_OFFSET;
WRITE_ONCE(call->resend_at, timo);
WRITE_ONCE(call->delay_ack_at, timo);
trace_rxrpc_timer(call, rxrpc_timer_init_for_reply, now);
}
if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
if (!rxrpc_rotate_tx_window(call, top, &summary)) {
rxrpc_proto_abort("TXL", call, top);
return false;
}
}
return rxrpc_end_tx_phase(call, true, "ETD");
}
static void rxrpc_input_update_ack_window(struct rxrpc_call *call,
rxrpc_seq_t window, rxrpc_seq_t wtop)
{
atomic64_set_release(&call->ackr_window, ((u64)wtop) << 32 | window);
}
/*
* Push a DATA packet onto the Rx queue.
*/
static void rxrpc_input_queue_data(struct rxrpc_call *call, struct sk_buff *skb,
rxrpc_seq_t window, rxrpc_seq_t wtop,
enum rxrpc_receive_trace why)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
__skb_queue_tail(&call->recvmsg_queue, skb);
rxrpc_input_update_ack_window(call, window, wtop);
trace_rxrpc_receive(call, last ? why + 1 : why, sp->hdr.serial, sp->hdr.seq);
}
/*
* Process a DATA packet.
*/
static void rxrpc_input_data_one(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct sk_buff *oos;
rxrpc_serial_t serial = sp->hdr.serial;
u64 win = atomic64_read(&call->ackr_window);
rxrpc_seq_t window = lower_32_bits(win);
rxrpc_seq_t wtop = upper_32_bits(win);
rxrpc_seq_t wlimit = window + call->rx_winsize - 1;
rxrpc_seq_t seq = sp->hdr.seq;
bool last = sp->hdr.flags & RXRPC_LAST_PACKET;
int ack_reason = -1;
rxrpc_inc_stat(call->rxnet, stat_rx_data);
if (sp->hdr.flags & RXRPC_REQUEST_ACK)
rxrpc_inc_stat(call->rxnet, stat_rx_data_reqack);
if (sp->hdr.flags & RXRPC_JUMBO_PACKET)
rxrpc_inc_stat(call->rxnet, stat_rx_data_jumbo);
if (last) {
if (test_and_set_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
seq + 1 != wtop) {
rxrpc_proto_abort("LSN", call, seq);
goto err_free;
}
} else {
if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
after_eq(seq, wtop)) {
pr_warn("Packet beyond last: c=%x q=%x window=%x-%x wlimit=%x\n",
call->debug_id, seq, window, wtop, wlimit);
rxrpc_proto_abort("LSA", call, seq);
goto err_free;
}
}
if (after(seq, call->rx_highest_seq))
call->rx_highest_seq = seq;
trace_rxrpc_rx_data(call->debug_id, seq, serial, sp->hdr.flags);
if (before(seq, window)) {
ack_reason = RXRPC_ACK_DUPLICATE;
goto send_ack;
}
if (after(seq, wlimit)) {
ack_reason = RXRPC_ACK_EXCEEDS_WINDOW;
goto send_ack;
}
/* Queue the packet. */
if (seq == window) {
rxrpc_seq_t reset_from;
bool reset_sack = false;
if (sp->hdr.flags & RXRPC_REQUEST_ACK)
ack_reason = RXRPC_ACK_REQUESTED;
/* Send an immediate ACK if we fill in a hole */
else if (!skb_queue_empty(&call->rx_oos_queue))
ack_reason = RXRPC_ACK_DELAY;
window++;
if (after(window, wtop))
wtop = window;
spin_lock(&call->recvmsg_queue.lock);
rxrpc_input_queue_data(call, skb, window, wtop, rxrpc_receive_queue);
skb = NULL;
while ((oos = skb_peek(&call->rx_oos_queue))) {
struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
if (after(osp->hdr.seq, window))
break;
__skb_unlink(oos, &call->rx_oos_queue);
last = osp->hdr.flags & RXRPC_LAST_PACKET;
seq = osp->hdr.seq;
if (!reset_sack) {
reset_from = seq;
reset_sack = true;
}
window++;
rxrpc_input_queue_data(call, oos, window, wtop,
rxrpc_receive_queue_oos);
}
spin_unlock(&call->recvmsg_queue.lock);
if (reset_sack) {
do {
call->ackr_sack_table[reset_from % RXRPC_SACK_SIZE] = 0;
} while (reset_from++, before(reset_from, window));
}
} else {
bool keep = false;
ack_reason = RXRPC_ACK_OUT_OF_SEQUENCE;
if (!call->ackr_sack_table[seq % RXRPC_SACK_SIZE]) {
call->ackr_sack_table[seq % RXRPC_SACK_SIZE] = 1;
keep = 1;
}
if (after(seq + 1, wtop)) {
wtop = seq + 1;
rxrpc_input_update_ack_window(call, window, wtop);
}
if (!keep) {
ack_reason = RXRPC_ACK_DUPLICATE;
goto send_ack;
}
skb_queue_walk(&call->rx_oos_queue, oos) {
struct rxrpc_skb_priv *osp = rxrpc_skb(oos);
if (after(osp->hdr.seq, seq)) {
__skb_queue_before(&call->rx_oos_queue, oos, skb);
goto oos_queued;
}
}
__skb_queue_tail(&call->rx_oos_queue, skb);
oos_queued:
trace_rxrpc_receive(call, last ? rxrpc_receive_oos_last : rxrpc_receive_oos,
sp->hdr.serial, sp->hdr.seq);
skb = NULL;
}
send_ack:
if (ack_reason < 0 &&
atomic_inc_return(&call->ackr_nr_unacked) > 2 &&
test_and_set_bit(RXRPC_CALL_IDLE_ACK_PENDING, &call->flags)) {
ack_reason = RXRPC_ACK_IDLE;
} else if (ack_reason >= 0) {
set_bit(RXRPC_CALL_IDLE_ACK_PENDING, &call->flags);
}
if (ack_reason >= 0)
rxrpc_send_ACK(call, ack_reason, serial,
rxrpc_propose_ack_input_data);
else
rxrpc_propose_delay_ACK(call, serial,
rxrpc_propose_ack_input_data);
err_free:
rxrpc_free_skb(skb, rxrpc_skb_freed);
}
/*
* Split a jumbo packet and file the bits separately.
*/
static bool rxrpc_input_split_jumbo(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_jumbo_header jhdr;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb), *jsp;
struct sk_buff *jskb;
unsigned int offset = sizeof(struct rxrpc_wire_header);
unsigned int len = skb->len - offset;
while (sp->hdr.flags & RXRPC_JUMBO_PACKET) {
if (len < RXRPC_JUMBO_SUBPKTLEN)
goto protocol_error;
if (sp->hdr.flags & RXRPC_LAST_PACKET)
goto protocol_error;
if (skb_copy_bits(skb, offset + RXRPC_JUMBO_DATALEN,
&jhdr, sizeof(jhdr)) < 0)
goto protocol_error;
jskb = skb_clone(skb, GFP_ATOMIC);
if (!jskb) {
kdebug("couldn't clone");
return false;
}
rxrpc_new_skb(jskb, rxrpc_skb_cloned_jumbo);
jsp = rxrpc_skb(jskb);
jsp->offset = offset;
jsp->len = RXRPC_JUMBO_DATALEN;
rxrpc_input_data_one(call, jskb);
sp->hdr.flags = jhdr.flags;
sp->hdr._rsvd = ntohs(jhdr._rsvd);
sp->hdr.seq++;
sp->hdr.serial++;
offset += RXRPC_JUMBO_SUBPKTLEN;
len -= RXRPC_JUMBO_SUBPKTLEN;
}
sp->offset = offset;
sp->len = len;
rxrpc_input_data_one(call, skb);
return true;
protocol_error:
return false;
}
/*
* Process a DATA packet, adding the packet to the Rx ring. The caller's
* packet ref must be passed on or discarded.
*/
static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
enum rxrpc_call_state state;
rxrpc_serial_t serial = sp->hdr.serial;
rxrpc_seq_t seq0 = sp->hdr.seq;
_enter("{%llx,%x},{%u,%x}",
atomic64_read(&call->ackr_window), call->rx_highest_seq,
skb->len, seq0);
_proto("Rx DATA %%%u { #%u f=%02x }",
sp->hdr.serial, seq0, sp->hdr.flags);
state = READ_ONCE(call->state);
if (state >= RXRPC_CALL_COMPLETE) {
rxrpc_free_skb(skb, rxrpc_skb_freed);
return;
}
/* Unshare the packet so that it can be modified for in-place
* decryption.
*/
if (sp->hdr.securityIndex != 0) {
struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
if (!nskb) {
rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
return;
}
if (nskb != skb) {
rxrpc_eaten_skb(skb, rxrpc_skb_received);
skb = nskb;
rxrpc_new_skb(skb, rxrpc_skb_unshared);
sp = rxrpc_skb(skb);
}
}
if (state == RXRPC_CALL_SERVER_RECV_REQUEST) {
unsigned long timo = READ_ONCE(call->next_req_timo);
unsigned long now, expect_req_by;
if (timo) {
now = jiffies;
expect_req_by = now + timo;
WRITE_ONCE(call->expect_req_by, expect_req_by);
rxrpc_reduce_call_timer(call, expect_req_by, now,
rxrpc_timer_set_for_idle);
}
}
spin_lock(&call->input_lock);
/* Received data implicitly ACKs all of the request packets we sent
* when we're acting as a client.
*/
if ((state == RXRPC_CALL_CLIENT_SEND_REQUEST ||
state == RXRPC_CALL_CLIENT_AWAIT_REPLY) &&
!rxrpc_receiving_reply(call))
goto out;
if (!rxrpc_input_split_jumbo(call, skb)) {
rxrpc_proto_abort("VLD", call, sp->hdr.seq);
goto out;
}
skb = NULL;
out:
trace_rxrpc_notify_socket(call->debug_id, serial);
rxrpc_notify_socket(call);
spin_unlock(&call->input_lock);
rxrpc_free_skb(skb, rxrpc_skb_freed);
_leave(" [queued]");
}
/*
* See if there's a cached RTT probe to complete.
*/
static void rxrpc_complete_rtt_probe(struct rxrpc_call *call,
ktime_t resp_time,
rxrpc_serial_t acked_serial,
rxrpc_serial_t ack_serial,
enum rxrpc_rtt_rx_trace type)
{
rxrpc_serial_t orig_serial;
unsigned long avail;
ktime_t sent_at;
bool matched = false;
int i;
avail = READ_ONCE(call->rtt_avail);
smp_rmb(); /* Read avail bits before accessing data. */
for (i = 0; i < ARRAY_SIZE(call->rtt_serial); i++) {
if (!test_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &avail))
continue;
sent_at = call->rtt_sent_at[i];
orig_serial = call->rtt_serial[i];
if (orig_serial == acked_serial) {
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
smp_mb(); /* Read data before setting avail bit */
set_bit(i, &call->rtt_avail);
if (type != rxrpc_rtt_rx_cancel)
rxrpc_peer_add_rtt(call, type, i, acked_serial, ack_serial,
sent_at, resp_time);
else
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_cancel, i,
orig_serial, acked_serial, 0, 0);
matched = true;
}
/* If a later serial is being acked, then mark this slot as
* being available.
*/
if (after(acked_serial, orig_serial)) {
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_obsolete, i,
orig_serial, acked_serial, 0, 0);
clear_bit(i + RXRPC_CALL_RTT_PEND_SHIFT, &call->rtt_avail);
smp_wmb();
set_bit(i, &call->rtt_avail);
}
}
if (!matched)
trace_rxrpc_rtt_rx(call, rxrpc_rtt_rx_lost, 9, 0, acked_serial, 0, 0);
}
/*
* Process the response to a ping that we sent to find out if we lost an ACK.
*
* If we got back a ping response that indicates a lower tx_top than what we
* had at the time of the ping transmission, we adjudge all the DATA packets
* sent between the response tx_top and the ping-time tx_top to have been lost.
*/
static void rxrpc_input_check_for_lost_ack(struct rxrpc_call *call)
{
if (after(call->acks_lost_top, call->acks_prev_seq) &&
!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
rxrpc_queue_call(call);
}
/*
* Process a ping response.
*/
static void rxrpc_input_ping_response(struct rxrpc_call *call,
ktime_t resp_time,
rxrpc_serial_t acked_serial,
rxrpc_serial_t ack_serial)
{
if (acked_serial == call->acks_lost_ping)
rxrpc_input_check_for_lost_ack(call);
}
/*
* Process the extra information that may be appended to an ACK packet
*/
static void rxrpc_input_ackinfo(struct rxrpc_call *call, struct sk_buff *skb,
struct rxrpc_ackinfo *ackinfo)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_peer *peer;
unsigned int mtu;
bool wake = false;
u32 rwind = ntohl(ackinfo->rwind);
_proto("Rx ACK %%%u Info { rx=%u max=%u rwin=%u jm=%u }",
sp->hdr.serial,
ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU),
rwind, ntohl(ackinfo->jumbo_max));
if (rwind > RXRPC_TX_MAX_WINDOW)
rwind = RXRPC_TX_MAX_WINDOW;
if (call->tx_winsize != rwind) {
if (rwind > call->tx_winsize)
wake = true;
trace_rxrpc_rx_rwind_change(call, sp->hdr.serial, rwind, wake);
call->tx_winsize = rwind;
}
if (call->cong_ssthresh > rwind)
call->cong_ssthresh = rwind;
mtu = min(ntohl(ackinfo->rxMTU), ntohl(ackinfo->maxMTU));
peer = call->peer;
if (mtu < peer->maxdata) {
spin_lock_bh(&peer->lock);
peer->maxdata = mtu;
peer->mtu = mtu + peer->hdrsize;
spin_unlock_bh(&peer->lock);
_net("Net MTU %u (maxdata %u)", peer->mtu, peer->maxdata);
}
if (wake)
wake_up(&call->waitq);
}
/*
* Process individual soft ACKs.
*
* Each ACK in the array corresponds to one packet and can be either an ACK or
* a NAK. If we get find an explicitly NAK'd packet we resend immediately;
* packets that lie beyond the end of the ACK list are scheduled for resend by
* the timer on the basis that the peer might just not have processed them at
* the time the ACK was sent.
*/
static void rxrpc_input_soft_acks(struct rxrpc_call *call, u8 *acks,
rxrpc_seq_t seq, int nr_acks,
struct rxrpc_ack_summary *summary)
{
unsigned int i;
for (i = 0; i < nr_acks; i++) {
if (acks[i] == RXRPC_ACK_TYPE_ACK) {
summary->nr_acks++;
summary->nr_new_acks++;
} else {
if (!summary->saw_nacks &&
call->acks_lowest_nak != seq + i) {
call->acks_lowest_nak = seq + i;
summary->new_low_nack = true;
}
summary->saw_nacks = true;
}
}
}
/*
* Return true if the ACK is valid - ie. it doesn't appear to have regressed
* with respect to the ack state conveyed by preceding ACKs.
*/
static bool rxrpc_is_ack_valid(struct rxrpc_call *call,
rxrpc_seq_t first_pkt, rxrpc_seq_t prev_pkt)
{
rxrpc_seq_t base = READ_ONCE(call->acks_first_seq);
if (after(first_pkt, base))
return true; /* The window advanced */
if (before(first_pkt, base))
return false; /* firstPacket regressed */
if (after_eq(prev_pkt, call->acks_prev_seq))
return true; /* previousPacket hasn't regressed. */
/* Some rx implementations put a serial number in previousPacket. */
if (after_eq(prev_pkt, base + call->tx_winsize))
return false;
return true;
}
/*
* Process an ACK packet.
*
* ack.firstPacket is the sequence number of the first soft-ACK'd/NAK'd packet
* in the ACK array. Anything before that is hard-ACK'd and may be discarded.
*
* A hard-ACK means that a packet has been processed and may be discarded; a
* soft-ACK means that the packet may be discarded and retransmission
* requested. A phase is complete when all packets are hard-ACK'd.
*/
static void rxrpc_input_ack(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_ack_summary summary = { 0 };
struct rxrpc_ackpacket ack;
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
struct rxrpc_ackinfo info;
struct sk_buff *skb_old = NULL, *skb_put = skb;
rxrpc_serial_t ack_serial, acked_serial;
rxrpc_seq_t first_soft_ack, hard_ack, prev_pkt;
int nr_acks, offset, ioffset;
_enter("");
offset = sizeof(struct rxrpc_wire_header);
if (skb_copy_bits(skb, offset, &ack, sizeof(ack)) < 0) {
rxrpc_proto_abort("XAK", call, 0);
goto out_not_locked;
}
offset += sizeof(ack);
ack_serial = sp->hdr.serial;
acked_serial = ntohl(ack.serial);
first_soft_ack = ntohl(ack.firstPacket);
prev_pkt = ntohl(ack.previousPacket);
hard_ack = first_soft_ack - 1;
nr_acks = ack.nAcks;
summary.ack_reason = (ack.reason < RXRPC_ACK__INVALID ?
ack.reason : RXRPC_ACK__INVALID);
trace_rxrpc_rx_ack(call, ack_serial, acked_serial,
first_soft_ack, prev_pkt,
summary.ack_reason, nr_acks);
rxrpc_inc_stat(call->rxnet, stat_rx_acks[ack.reason]);
switch (ack.reason) {
case RXRPC_ACK_PING_RESPONSE:
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
rxrpc_rtt_rx_ping_response);
break;
case RXRPC_ACK_REQUESTED:
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
rxrpc_rtt_rx_requested_ack);
break;
default:
if (acked_serial != 0)
rxrpc_complete_rtt_probe(call, skb->tstamp, acked_serial, ack_serial,
rxrpc_rtt_rx_cancel);
break;
}
if (ack.reason == RXRPC_ACK_PING) {
_proto("Rx ACK %%%u PING Request", ack_serial);
rxrpc_send_ACK(call, RXRPC_ACK_PING_RESPONSE, ack_serial,
rxrpc_propose_ack_respond_to_ping);
} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
rxrpc_send_ACK(call, RXRPC_ACK_REQUESTED, ack_serial,
rxrpc_propose_ack_respond_to_ack);
}
/* If we get an EXCEEDS_WINDOW ACK from the server, it probably
* indicates that the client address changed due to NAT. The server
* lost the call because it switched to a different peer.
*/
if (unlikely(ack.reason == RXRPC_ACK_EXCEEDS_WINDOW) &&
first_soft_ack == 1 &&
prev_pkt == 0 &&
rxrpc_is_client_call(call)) {
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
0, -ENETRESET);
return;
}
/* If we get an OUT_OF_SEQUENCE ACK from the server, that can also
* indicate a change of address. However, we can retransmit the call
* if we still have it buffered to the beginning.
*/
if (unlikely(ack.reason == RXRPC_ACK_OUT_OF_SEQUENCE) &&
first_soft_ack == 1 &&
prev_pkt == 0 &&
call->acks_hard_ack == 0 &&
rxrpc_is_client_call(call)) {
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
0, -ENETRESET);
return;
}
/* Discard any out-of-order or duplicate ACKs (outside lock). */
if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
first_soft_ack, call->acks_first_seq,
prev_pkt, call->acks_prev_seq);
goto out_not_locked;
}
info.rxMTU = 0;
ioffset = offset + nr_acks + 3;
if (skb->len >= ioffset + sizeof(info) &&
skb_copy_bits(skb, ioffset, &info, sizeof(info)) < 0) {
rxrpc_proto_abort("XAI", call, 0);
goto out_not_locked;
}
if (nr_acks > 0)
skb_condense(skb);
spin_lock(&call->input_lock);
/* Discard any out-of-order or duplicate ACKs (inside lock). */
if (!rxrpc_is_ack_valid(call, first_soft_ack, prev_pkt)) {
trace_rxrpc_rx_discard_ack(call->debug_id, ack_serial,
first_soft_ack, call->acks_first_seq,
prev_pkt, call->acks_prev_seq);
goto out;
}
call->acks_latest_ts = skb->tstamp;
call->acks_first_seq = first_soft_ack;
call->acks_prev_seq = prev_pkt;
switch (ack.reason) {
case RXRPC_ACK_PING:
break;
case RXRPC_ACK_PING_RESPONSE:
rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
ack_serial);
fallthrough;
default:
if (after(acked_serial, call->acks_highest_serial))
call->acks_highest_serial = acked_serial;
break;
}
/* Parse rwind and mtu sizes if provided. */
if (info.rxMTU)
rxrpc_input_ackinfo(call, skb, &info);
if (first_soft_ack == 0) {
rxrpc_proto_abort("AK0", call, 0);
goto out;
}
/* Ignore ACKs unless we are or have just been transmitting. */
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
case RXRPC_CALL_SERVER_SEND_REPLY:
case RXRPC_CALL_SERVER_AWAIT_ACK:
break;
default:
goto out;
}
if (before(hard_ack, call->acks_hard_ack) ||
after(hard_ack, call->tx_top)) {
rxrpc_proto_abort("AKW", call, 0);
goto out;
}
if (nr_acks > call->tx_top - hard_ack) {
rxrpc_proto_abort("AKN", call, 0);
goto out;
}
if (after(hard_ack, call->acks_hard_ack)) {
if (rxrpc_rotate_tx_window(call, hard_ack, &summary)) {
rxrpc_end_tx_phase(call, false, "ETA");
goto out;
}
}
if (nr_acks > 0) {
if (offset > (int)skb->len - nr_acks) {
rxrpc_proto_abort("XSA", call, 0);
goto out;
}
spin_lock(&call->acks_ack_lock);
skb_old = call->acks_soft_tbl;
call->acks_soft_tbl = skb;
spin_unlock(&call->acks_ack_lock);
rxrpc_input_soft_acks(call, skb->data + offset, first_soft_ack,
nr_acks, &summary);
skb_put = NULL;
} else if (call->acks_soft_tbl) {
spin_lock(&call->acks_ack_lock);
skb_old = call->acks_soft_tbl;
call->acks_soft_tbl = NULL;
spin_unlock(&call->acks_ack_lock);
}
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags) &&
summary.nr_acks == call->tx_top - hard_ack &&
rxrpc_is_client_call(call))
rxrpc_propose_ping(call, ack_serial,
rxrpc_propose_ack_ping_for_lost_reply);
rxrpc_congestion_management(call, skb, &summary, acked_serial);
out:
spin_unlock(&call->input_lock);
out_not_locked:
rxrpc_free_skb(skb_put, rxrpc_skb_freed);
rxrpc_free_skb(skb_old, rxrpc_skb_freed);
}
/*
* Process an ACKALL packet.
*/
static void rxrpc_input_ackall(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_ack_summary summary = { 0 };
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
_proto("Rx ACKALL %%%u", sp->hdr.serial);
spin_lock(&call->input_lock);
if (rxrpc_rotate_tx_window(call, call->tx_top, &summary))
rxrpc_end_tx_phase(call, false, "ETL");
spin_unlock(&call->input_lock);
}
/*
* Process an ABORT packet directed at a call.
*/
static void rxrpc_input_abort(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
__be32 wtmp;
u32 abort_code = RX_CALL_DEAD;
_enter("");
if (skb->len >= 4 &&
skb_copy_bits(skb, sizeof(struct rxrpc_wire_header),
&wtmp, sizeof(wtmp)) >= 0)
abort_code = ntohl(wtmp);
trace_rxrpc_rx_abort(call, sp->hdr.serial, abort_code);
_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
abort_code, -ECONNABORTED);
}
/*
* Process an incoming call packet.
*/
static void rxrpc_input_call_packet(struct rxrpc_call *call,
struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
unsigned long timo;
_enter("%p,%p", call, skb);
timo = READ_ONCE(call->next_rx_timo);
if (timo) {
unsigned long now = jiffies, expect_rx_by;
expect_rx_by = now + timo;
WRITE_ONCE(call->expect_rx_by, expect_rx_by);
rxrpc_reduce_call_timer(call, expect_rx_by, now,
rxrpc_timer_set_for_normal);
}
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_DATA:
rxrpc_input_data(call, skb);
goto no_free;
case RXRPC_PACKET_TYPE_ACK:
rxrpc_input_ack(call, skb);
goto no_free;
case RXRPC_PACKET_TYPE_BUSY:
_proto("Rx BUSY %%%u", sp->hdr.serial);
/* Just ignore BUSY packets from the server; the retry and
* lifespan timers will take care of business. BUSY packets
* from the client don't make sense.
*/
break;
case RXRPC_PACKET_TYPE_ABORT:
rxrpc_input_abort(call, skb);
break;
case RXRPC_PACKET_TYPE_ACKALL:
rxrpc_input_ackall(call, skb);
break;
default:
break;
}
rxrpc_free_skb(skb, rxrpc_skb_freed);
no_free:
_leave("");
}
/*
* Handle a new service call on a channel implicitly completing the preceding
* call on that channel. This does not apply to client conns.
*
* TODO: If callNumber > call_id + 1, renegotiate security.
*/
static void rxrpc_input_implicit_end_call(struct rxrpc_sock *rx,
struct rxrpc_connection *conn,
struct rxrpc_call *call)
{
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_SERVER_AWAIT_ACK:
rxrpc_call_completed(call);
fallthrough;
case RXRPC_CALL_COMPLETE:
break;
default:
if (rxrpc_abort_call("IMP", call, 0, RX_CALL_DEAD, -ESHUTDOWN)) {
set_bit(RXRPC_CALL_EV_ABORT, &call->events);
rxrpc_queue_call(call);
}
trace_rxrpc_improper_term(call);
break;
}
spin_lock(&rx->incoming_lock);
__rxrpc_disconnect_call(conn, call);
spin_unlock(&rx->incoming_lock);
}
/*
* post connection-level events to the connection
* - this includes challenges, responses, some aborts and call terminal packet
* retransmission.
*/
static void rxrpc_post_packet_to_conn(struct rxrpc_connection *conn,
struct sk_buff *skb)
{
_enter("%p,%p", conn, skb);
skb_queue_tail(&conn->rx_queue, skb);
rxrpc_queue_conn(conn);
}
/*
* post endpoint-level events to the local endpoint
* - this includes debug and version messages
*/
static void rxrpc_post_packet_to_local(struct rxrpc_local *local,
struct sk_buff *skb)
{
_enter("%p,%p", local, skb);
if (rxrpc_get_local_maybe(local)) {
skb_queue_tail(&local->event_queue, skb);
rxrpc_queue_local(local);
} else {
rxrpc_free_skb(skb, rxrpc_skb_freed);
}
}
/*
* put a packet up for transport-level abort
*/
static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
{
if (rxrpc_get_local_maybe(local)) {
skb_queue_tail(&local->reject_queue, skb);
rxrpc_queue_local(local);
} else {
rxrpc_free_skb(skb, rxrpc_skb_freed);
}
}
/*
* Extract the wire header from a packet and translate the byte order.
*/
static noinline
int rxrpc_extract_header(struct rxrpc_skb_priv *sp, struct sk_buff *skb)
{
struct rxrpc_wire_header whdr;
/* dig out the RxRPC connection details */
if (skb_copy_bits(skb, 0, &whdr, sizeof(whdr)) < 0) {
trace_rxrpc_rx_eproto(NULL, sp->hdr.serial,
tracepoint_string("bad_hdr"));
return -EBADMSG;
}
memset(sp, 0, sizeof(*sp));
sp->hdr.epoch = ntohl(whdr.epoch);
sp->hdr.cid = ntohl(whdr.cid);
sp->hdr.callNumber = ntohl(whdr.callNumber);
sp->hdr.seq = ntohl(whdr.seq);
sp->hdr.serial = ntohl(whdr.serial);
sp->hdr.flags = whdr.flags;
sp->hdr.type = whdr.type;
sp->hdr.userStatus = whdr.userStatus;
sp->hdr.securityIndex = whdr.securityIndex;
sp->hdr._rsvd = ntohs(whdr._rsvd);
sp->hdr.serviceId = ntohs(whdr.serviceId);
return 0;
}
/*
* handle data received on the local endpoint
* - may be called in interrupt context
*
* [!] Note that as this is called from the encap_rcv hook, the socket is not
* held locked by the caller and nothing prevents sk_user_data on the UDP from
* being cleared in the middle of processing this function.
*
* Called with the RCU read lock held from the IP layer via UDP.
*/
int rxrpc_input_packet(struct sock *udp_sk, struct sk_buff *skb)
{
struct rxrpc_local *local = rcu_dereference_sk_user_data(udp_sk);
struct rxrpc_connection *conn;
struct rxrpc_channel *chan;
struct rxrpc_call *call = NULL;
struct rxrpc_skb_priv *sp;
struct rxrpc_peer *peer = NULL;
struct rxrpc_sock *rx = NULL;
unsigned int channel;
_enter("%p", udp_sk);
if (unlikely(!local)) {
kfree_skb(skb);
return 0;
}
if (skb->tstamp == 0)
skb->tstamp = ktime_get_real();
rxrpc_new_skb(skb, rxrpc_skb_received);
skb_pull(skb, sizeof(struct udphdr));
/* The UDP protocol already released all skb resources;
* we are free to add our own data there.
*/
sp = rxrpc_skb(skb);
/* dig out the RxRPC connection details */
if (rxrpc_extract_header(sp, skb) < 0)
goto bad_message;
if (IS_ENABLED(CONFIG_AF_RXRPC_INJECT_LOSS)) {
static int lose;
if ((lose++ & 7) == 7) {
trace_rxrpc_rx_lose(sp);
rxrpc_free_skb(skb, rxrpc_skb_lost);
return 0;
}
}
if (skb->tstamp == 0)
skb->tstamp = ktime_get_real();
trace_rxrpc_rx_packet(sp);
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_VERSION:
if (rxrpc_to_client(sp))
goto discard;
rxrpc_post_packet_to_local(local, skb);
goto out;
case RXRPC_PACKET_TYPE_BUSY:
if (rxrpc_to_server(sp))
goto discard;
fallthrough;
case RXRPC_PACKET_TYPE_ACK:
case RXRPC_PACKET_TYPE_ACKALL:
if (sp->hdr.callNumber == 0)
goto bad_message;
fallthrough;
case RXRPC_PACKET_TYPE_ABORT:
break;
case RXRPC_PACKET_TYPE_DATA:
if (sp->hdr.callNumber == 0 ||
sp->hdr.seq == 0)
goto bad_message;
/* Unshare the packet so that it can be modified for in-place
* decryption.
*/
if (sp->hdr.securityIndex != 0) {
struct sk_buff *nskb = skb_unshare(skb, GFP_ATOMIC);
if (!nskb) {
rxrpc_eaten_skb(skb, rxrpc_skb_unshared_nomem);
goto out;
}
if (nskb != skb) {
rxrpc_eaten_skb(skb, rxrpc_skb_received);
skb = nskb;
rxrpc_new_skb(skb, rxrpc_skb_unshared);
sp = rxrpc_skb(skb);
}
}
break;
case RXRPC_PACKET_TYPE_CHALLENGE:
if (rxrpc_to_server(sp))
goto discard;
break;
case RXRPC_PACKET_TYPE_RESPONSE:
if (rxrpc_to_client(sp))
goto discard;
break;
/* Packet types 9-11 should just be ignored. */
case RXRPC_PACKET_TYPE_PARAMS:
case RXRPC_PACKET_TYPE_10:
case RXRPC_PACKET_TYPE_11:
goto discard;
default:
_proto("Rx Bad Packet Type %u", sp->hdr.type);
goto bad_message;
}
if (sp->hdr.serviceId == 0)
goto bad_message;
if (rxrpc_to_server(sp)) {
/* Weed out packets to services we're not offering. Packets
* that would begin a call are explicitly rejected and the rest
* are just discarded.
*/
rx = rcu_dereference(local->service);
if (!rx || (sp->hdr.serviceId != rx->srx.srx_service &&
sp->hdr.serviceId != rx->second_service)) {
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
sp->hdr.seq == 1)
goto unsupported_service;
goto discard;
}
}
conn = rxrpc_find_connection_rcu(local, skb, &peer);
if (conn) {
if (sp->hdr.securityIndex != conn->security_ix)
goto wrong_security;
if (sp->hdr.serviceId != conn->service_id) {
int old_id;
if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags))
goto reupgrade;
old_id = cmpxchg(&conn->service_id, conn->params.service_id,
sp->hdr.serviceId);
if (old_id != conn->params.service_id &&
old_id != sp->hdr.serviceId)
goto reupgrade;
}
if (sp->hdr.callNumber == 0) {
/* Connection-level packet */
_debug("CONN %p {%d}", conn, conn->debug_id);
rxrpc_post_packet_to_conn(conn, skb);
goto out;
}
if ((int)sp->hdr.serial - (int)conn->hi_serial > 0)
conn->hi_serial = sp->hdr.serial;
/* Call-bound packets are routed by connection channel. */
channel = sp->hdr.cid & RXRPC_CHANNELMASK;
chan = &conn->channels[channel];
/* Ignore really old calls */
if (sp->hdr.callNumber < chan->last_call)
goto discard;
if (sp->hdr.callNumber == chan->last_call) {
if (chan->call ||
sp->hdr.type == RXRPC_PACKET_TYPE_ABORT)
goto discard;
/* For the previous service call, if completed
* successfully, we discard all further packets.
*/
if (rxrpc_conn_is_service(conn) &&
chan->last_type == RXRPC_PACKET_TYPE_ACK)
goto discard;
/* But otherwise we need to retransmit the final packet
* from data cached in the connection record.
*/
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA)
trace_rxrpc_rx_data(chan->call_debug_id,
sp->hdr.seq,
sp->hdr.serial,
sp->hdr.flags);
rxrpc_post_packet_to_conn(conn, skb);
goto out;
}
call = rcu_dereference(chan->call);
if (sp->hdr.callNumber > chan->call_id) {
if (rxrpc_to_client(sp))
goto reject_packet;
if (call)
rxrpc_input_implicit_end_call(rx, conn, call);
call = NULL;
}
if (call) {
if (sp->hdr.serviceId != call->service_id)
call->service_id = sp->hdr.serviceId;
if ((int)sp->hdr.serial - (int)call->rx_serial > 0)
call->rx_serial = sp->hdr.serial;
if (!test_bit(RXRPC_CALL_RX_HEARD, &call->flags))
set_bit(RXRPC_CALL_RX_HEARD, &call->flags);
}
}
if (!call || refcount_read(&call->ref) == 0) {
if (rxrpc_to_client(sp) ||
sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
goto bad_message;
if (sp->hdr.seq != 1)
goto discard;
call = rxrpc_new_incoming_call(local, rx, skb);
if (!call)
goto reject_packet;
}
/* Process a call packet; this either discards or passes on the ref
* elsewhere.
*/
rxrpc_input_call_packet(call, skb);
goto out;
discard:
rxrpc_free_skb(skb, rxrpc_skb_freed);
out:
trace_rxrpc_rx_done(0, 0);
return 0;
wrong_security:
trace_rxrpc_abort(0, "SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RXKADINCONSISTENCY, EBADMSG);
skb->priority = RXKADINCONSISTENCY;
goto post_abort;
unsupported_service:
trace_rxrpc_abort(0, "INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_INVALID_OPERATION, EOPNOTSUPP);
skb->priority = RX_INVALID_OPERATION;
goto post_abort;
reupgrade:
trace_rxrpc_abort(0, "UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_PROTOCOL_ERROR, EBADMSG);
goto protocol_error;
bad_message:
trace_rxrpc_abort(0, "BAD", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_PROTOCOL_ERROR, EBADMSG);
protocol_error:
skb->priority = RX_PROTOCOL_ERROR;
post_abort:
skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
reject_packet:
trace_rxrpc_rx_done(skb->mark, skb->priority);
rxrpc_reject_packet(local, skb);
_leave(" [badmsg]");
return 0;
}