diff options
Diffstat (limited to 'net/rxrpc/input.c')
| -rw-r--r-- | net/rxrpc/input.c | 1475 |
1 files changed, 1475 insertions, 0 deletions
diff --git a/net/rxrpc/input.c b/net/rxrpc/input.c new file mode 100644 index 000000000..e9178115a --- /dev/null +++ b/net/rxrpc/input.c @@ -0,0 +1,1475 @@ +// 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 <linux/module.h> +#include <linux/net.h> +#include <linux/skbuff.h> +#include <linux/errqueue.h> +#include <linux/udp.h> +#include <linux/in.h> +#include <linux/in6.h> +#include <linux/icmp.h> +#include <linux/gfp.h> +#include <net/sock.h> +#include <net/af_rxrpc.h> +#include <net/ip.h> +#include <net/udp.h> +#include <net/net_namespace.h> +#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->tx_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; + + switch (call->cong_mode) { + case RXRPC_CALL_SLOW_START: + if (summary->nr_nacks > 0) + 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->nr_nacks > 0) + 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->nr_nacks == 0) + 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->nr_nacks == 0) + 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_RXTX_BUFF_SIZE - 1) + cwnd = RXRPC_RXTX_BUFF_SIZE - 1; + 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 (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & + RXRPC_TX_ANNO_LAST || + summary->nr_acks != call->tx_top - call->tx_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 sk_buff *skb, *list = NULL; + bool rot_last = false; + int ix; + u8 annotation; + + if (call->acks_lowest_nak == call->tx_hard_ack) { + call->acks_lowest_nak = to; + } else if (before_eq(call->acks_lowest_nak, to)) { + summary->new_low_nack = true; + call->acks_lowest_nak = to; + } + + spin_lock(&call->lock); + + while (before(call->tx_hard_ack, to)) { + call->tx_hard_ack++; + ix = call->tx_hard_ack & RXRPC_RXTX_BUFF_MASK; + skb = call->rxtx_buffer[ix]; + annotation = call->rxtx_annotations[ix]; + rxrpc_see_skb(skb, rxrpc_skb_rotated); + call->rxtx_buffer[ix] = NULL; + call->rxtx_annotations[ix] = 0; + skb->next = list; + list = skb; + + if (annotation & RXRPC_TX_ANNO_LAST) { + set_bit(RXRPC_CALL_TX_LAST, &call->flags); + rot_last = true; + } + if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK) + summary->nr_rot_new_acks++; + } + + spin_unlock(&call->lock); + + trace_rxrpc_transmit(call, (rot_last ? + rxrpc_transmit_rotate_last : + rxrpc_transmit_rotate)); + wake_up(&call->waitq); + + while (list) { + skb = list; + list = skb->next; + skb_mark_not_on_list(skb); + rxrpc_free_skb(skb, rxrpc_skb_freed); + } + + 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_transmit(call, rxrpc_transmit_await_reply); + else + trace_rxrpc_transmit(call, rxrpc_transmit_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) { + spin_lock_bh(&call->lock); + call->ackr_reason = 0; + spin_unlock_bh(&call->lock); + now = jiffies; + timo = now + MAX_JIFFY_OFFSET; + WRITE_ONCE(call->resend_at, timo); + WRITE_ONCE(call->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; + } + } + if (!rxrpc_end_tx_phase(call, true, "ETD")) + return false; + call->tx_phase = false; + return true; +} + +/* + * Scan a data packet to validate its structure and to work out how many + * subpackets it contains. + * + * A jumbo packet is a collection of consecutive packets glued together with + * little headers between that indicate how to change the initial header for + * each subpacket. + * + * RXRPC_JUMBO_PACKET must be set on all but the last subpacket - and all but + * the last are RXRPC_JUMBO_DATALEN in size. The last subpacket may be of any + * size. + */ +static bool rxrpc_validate_data(struct sk_buff *skb) +{ + struct rxrpc_skb_priv *sp = rxrpc_skb(skb); + unsigned int offset = sizeof(struct rxrpc_wire_header); + unsigned int len = skb->len; + u8 flags = sp->hdr.flags; + + for (;;) { + if (flags & RXRPC_REQUEST_ACK) + __set_bit(sp->nr_subpackets, sp->rx_req_ack); + sp->nr_subpackets++; + + if (!(flags & RXRPC_JUMBO_PACKET)) + break; + + if (len - offset < RXRPC_JUMBO_SUBPKTLEN) + goto protocol_error; + if (flags & RXRPC_LAST_PACKET) + goto protocol_error; + offset += RXRPC_JUMBO_DATALEN; + if (skb_copy_bits(skb, offset, &flags, 1) < 0) + goto protocol_error; + offset += sizeof(struct rxrpc_jumbo_header); + } + + if (flags & RXRPC_LAST_PACKET) + sp->rx_flags |= RXRPC_SKB_INCL_LAST; + return true; + +protocol_error: + return false; +} + +/* + * Handle reception of a duplicate packet. + * + * We have to take care to avoid an attack here whereby we're given a series of + * jumbograms, each with a sequence number one before the preceding one and + * filled up to maximum UDP size. If they never send us the first packet in + * the sequence, they can cause us to have to hold on to around 2MiB of kernel + * space until the call times out. + * + * We limit the space usage by only accepting three duplicate jumbo packets per + * call. After that, we tell the other side we're no longer accepting jumbos + * (that information is encoded in the ACK packet). + */ +static void rxrpc_input_dup_data(struct rxrpc_call *call, rxrpc_seq_t seq, + bool is_jumbo, bool *_jumbo_bad) +{ + /* Discard normal packets that are duplicates. */ + if (is_jumbo) + return; + + /* Skip jumbo subpackets that are duplicates. When we've had three or + * more partially duplicate jumbo packets, we refuse to take any more + * jumbos for this call. + */ + if (!*_jumbo_bad) { + call->nr_jumbo_bad++; + *_jumbo_bad = true; + } +} + +/* + * 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; + unsigned int j, nr_subpackets, nr_unacked = 0; + rxrpc_serial_t serial = sp->hdr.serial, ack_serial = serial; + rxrpc_seq_t seq0 = sp->hdr.seq, hard_ack; + bool immediate_ack = false, jumbo_bad = false; + u8 ack = 0; + + _enter("{%u,%u},{%u,%u}", + call->rx_hard_ack, call->rx_top, skb->len, seq0); + + _proto("Rx DATA %%%u { #%u f=%02x n=%u }", + sp->hdr.serial, seq0, sp->hdr.flags, sp->nr_subpackets); + + state = READ_ONCE(call->state); + if (state >= RXRPC_CALL_COMPLETE) { + rxrpc_free_skb(skb, rxrpc_skb_freed); + return; + } + + 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 unlock; + + hard_ack = READ_ONCE(call->rx_hard_ack); + + nr_subpackets = sp->nr_subpackets; + if (nr_subpackets > 1) { + if (call->nr_jumbo_bad > 3) { + ack = RXRPC_ACK_NOSPACE; + ack_serial = serial; + goto ack; + } + } + + for (j = 0; j < nr_subpackets; j++) { + rxrpc_serial_t serial = sp->hdr.serial + j; + rxrpc_seq_t seq = seq0 + j; + unsigned int ix = seq & RXRPC_RXTX_BUFF_MASK; + bool terminal = (j == nr_subpackets - 1); + bool last = terminal && (sp->rx_flags & RXRPC_SKB_INCL_LAST); + u8 flags, annotation = j; + + _proto("Rx DATA+%u %%%u { #%x t=%u l=%u }", + j, serial, seq, terminal, last); + + if (last) { + if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && + seq != call->rx_top) { + rxrpc_proto_abort("LSN", call, seq); + goto unlock; + } + } else { + if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) && + after_eq(seq, call->rx_top)) { + rxrpc_proto_abort("LSA", call, seq); + goto unlock; + } + } + + flags = 0; + if (last) + flags |= RXRPC_LAST_PACKET; + if (!terminal) + flags |= RXRPC_JUMBO_PACKET; + if (test_bit(j, sp->rx_req_ack)) + flags |= RXRPC_REQUEST_ACK; + trace_rxrpc_rx_data(call->debug_id, seq, serial, flags, annotation); + + if (before_eq(seq, hard_ack)) { + ack = RXRPC_ACK_DUPLICATE; + ack_serial = serial; + continue; + } + + if (call->rxtx_buffer[ix]) { + rxrpc_input_dup_data(call, seq, nr_subpackets > 1, + &jumbo_bad); + if (ack != RXRPC_ACK_DUPLICATE) { + ack = RXRPC_ACK_DUPLICATE; + ack_serial = serial; + } + immediate_ack = true; + continue; + } + + if (after(seq, hard_ack + call->rx_winsize)) { + ack = RXRPC_ACK_EXCEEDS_WINDOW; + ack_serial = serial; + if (flags & RXRPC_JUMBO_PACKET) { + if (!jumbo_bad) { + call->nr_jumbo_bad++; + jumbo_bad = true; + } + } + + goto ack; + } + + if (flags & RXRPC_REQUEST_ACK && !ack) { + ack = RXRPC_ACK_REQUESTED; + ack_serial = serial; + } + + if (after(seq0, call->ackr_highest_seq)) + call->ackr_highest_seq = seq0; + + /* Queue the packet. We use a couple of memory barriers here as need + * to make sure that rx_top is perceived to be set after the buffer + * pointer and that the buffer pointer is set after the annotation and + * the skb data. + * + * Barriers against rxrpc_recvmsg_data() and rxrpc_rotate_rx_window() + * and also rxrpc_fill_out_ack(). + */ + if (!terminal) + rxrpc_get_skb(skb, rxrpc_skb_got); + call->rxtx_annotations[ix] = annotation; + smp_wmb(); + call->rxtx_buffer[ix] = skb; + if (after(seq, call->rx_top)) { + smp_store_release(&call->rx_top, seq); + } else if (before(seq, call->rx_top)) { + /* Send an immediate ACK if we fill in a hole */ + if (!ack) { + ack = RXRPC_ACK_DELAY; + ack_serial = serial; + } + immediate_ack = true; + } + + if (terminal) { + /* From this point on, we're not allowed to touch the + * packet any longer as its ref now belongs to the Rx + * ring. + */ + skb = NULL; + sp = NULL; + } + + nr_unacked++; + + if (last) { + set_bit(RXRPC_CALL_RX_LAST, &call->flags); + if (!ack) { + ack = RXRPC_ACK_DELAY; + ack_serial = serial; + } + trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq); + } else { + trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq); + } + + if (after_eq(seq, call->rx_expect_next)) { + if (after(seq, call->rx_expect_next)) { + _net("OOS %u > %u", seq, call->rx_expect_next); + ack = RXRPC_ACK_OUT_OF_SEQUENCE; + ack_serial = serial; + } + call->rx_expect_next = seq + 1; + } + if (!ack) + ack_serial = serial; + } + +ack: + if (atomic_add_return(nr_unacked, &call->ackr_nr_unacked) > 2 && !ack) + ack = RXRPC_ACK_IDLE; + + if (ack) + rxrpc_propose_ACK(call, ack, ack_serial, + immediate_ack, true, + rxrpc_propose_ack_input_data); + else + rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, + false, true, + rxrpc_propose_ack_input_data); + + trace_rxrpc_notify_socket(call->debug_id, serial); + rxrpc_notify_socket(call); + +unlock: + 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) +{ + rxrpc_seq_t top, bottom, seq; + bool resend = false; + + spin_lock_bh(&call->lock); + + bottom = call->tx_hard_ack + 1; + top = call->acks_lost_top; + if (before(bottom, top)) { + for (seq = bottom; before_eq(seq, top); seq++) { + int ix = seq & RXRPC_RXTX_BUFF_MASK; + u8 annotation = call->rxtx_annotations[ix]; + u8 anno_type = annotation & RXRPC_TX_ANNO_MASK; + + if (anno_type != RXRPC_TX_ANNO_UNACK) + continue; + annotation &= ~RXRPC_TX_ANNO_MASK; + annotation |= RXRPC_TX_ANNO_RETRANS; + call->rxtx_annotations[ix] = annotation; + resend = true; + } + } + + spin_unlock_bh(&call->lock); + + if (resend && !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_RXTX_BUFF_SIZE - 1) + rwind = RXRPC_RXTX_BUFF_SIZE - 1; + 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) +{ + int ix; + u8 annotation, anno_type; + + for (; nr_acks > 0; nr_acks--, seq++) { + ix = seq & RXRPC_RXTX_BUFF_MASK; + annotation = call->rxtx_annotations[ix]; + anno_type = annotation & RXRPC_TX_ANNO_MASK; + annotation &= ~RXRPC_TX_ANNO_MASK; + switch (*acks++) { + case RXRPC_ACK_TYPE_ACK: + summary->nr_acks++; + if (anno_type == RXRPC_TX_ANNO_ACK) + continue; + summary->nr_new_acks++; + call->rxtx_annotations[ix] = + RXRPC_TX_ANNO_ACK | annotation; + break; + case RXRPC_ACK_TYPE_NACK: + if (!summary->nr_nacks && + call->acks_lowest_nak != seq) { + call->acks_lowest_nak = seq; + summary->new_low_nack = true; + } + summary->nr_nacks++; + if (anno_type == RXRPC_TX_ANNO_NAK) + continue; + summary->nr_new_nacks++; + if (anno_type == RXRPC_TX_ANNO_RETRANS) + continue; + call->rxtx_annotations[ix] = + RXRPC_TX_ANNO_NAK | annotation; + break; + default: + return rxrpc_proto_abort("SFT", call, 0); + } + } +} + +/* + * 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_skb_priv *sp = rxrpc_skb(skb); + union { + struct rxrpc_ackpacket ack; + struct rxrpc_ackinfo info; + u8 acks[RXRPC_MAXACKS]; + } buf; + 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, &buf.ack, sizeof(buf.ack)) < 0) { + _debug("extraction failure"); + return rxrpc_proto_abort("XAK", call, 0); + } + offset += sizeof(buf.ack); + + ack_serial = sp->hdr.serial; + acked_serial = ntohl(buf.ack.serial); + first_soft_ack = ntohl(buf.ack.firstPacket); + prev_pkt = ntohl(buf.ack.previousPacket); + hard_ack = first_soft_ack - 1; + nr_acks = buf.ack.nAcks; + summary.ack_reason = (buf.ack.reason < RXRPC_ACK__INVALID ? + buf.ack.reason : RXRPC_ACK__INVALID); + + trace_rxrpc_rx_ack(call, ack_serial, acked_serial, + first_soft_ack, prev_pkt, + summary.ack_reason, nr_acks); + + switch (buf.ack.reason) { + case RXRPC_ACK_PING_RESPONSE: + rxrpc_input_ping_response(call, skb->tstamp, acked_serial, + ack_serial); + 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 (buf.ack.reason == RXRPC_ACK_PING) { + _proto("Rx ACK %%%u PING Request", ack_serial); + rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE, + ack_serial, true, true, + rxrpc_propose_ack_respond_to_ping); + } else if (sp->hdr.flags & RXRPC_REQUEST_ACK) { + rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, + ack_serial, true, true, + rxrpc_propose_ack_respond_to_ack); + } + + /* 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); + return; + } + + buf.info.rxMTU = 0; + ioffset = offset + nr_acks + 3; + if (skb->len >= ioffset + sizeof(buf.info) && + skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0) + return rxrpc_proto_abort("XAI", call, 0); + + 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; + + /* Parse rwind and mtu sizes if provided. */ + if (buf.info.rxMTU) + rxrpc_input_ackinfo(call, skb, &buf.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->tx_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->tx_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 (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0) { + rxrpc_proto_abort("XSA", call, 0); + goto out; + } + rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks, + &summary); + } + + if (call->rxtx_annotations[call->tx_top & RXRPC_RXTX_BUFF_MASK] & + RXRPC_TX_ANNO_LAST && + summary.nr_acks == call->tx_top - hard_ack && + rxrpc_is_client_call(call)) + rxrpc_propose_ACK(call, RXRPC_ACK_PING, ack_serial, + false, true, + rxrpc_propose_ack_ping_for_lost_reply); + + rxrpc_congestion_management(call, skb, &summary, acked_serial); +out: + spin_unlock(&call->input_lock); +} + +/* + * 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); + break; + + 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; + if (!rxrpc_validate_data(skb)) + 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, 0); + 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; +} |