linux/net/rxrpc/input.c
David Howells 4e255721d1 rxrpc: Add service upgrade support for client connections
Make it possible for a client to use AuriStor's service upgrade facility.

The client does this by adding an RXRPC_UPGRADE_SERVICE control message to
the first sendmsg() of a call.  This takes no parameters.

When recvmsg() starts returning data from the call, the service ID field in
the returned msg_name will reflect the result of the upgrade attempt.  If
the upgrade was ignored, srx_service will match what was set in the
sendmsg(); if the upgrade happened the srx_service will be altered to
indicate the service the server upgraded to.

Note that:

 (1) The choice of upgrade service is up to the server

 (2) Further client calls to the same server that would share a connection
     are blocked if an upgrade probe is in progress.

 (3) This should only be used to probe the service.  Clients should then
     use the returned service ID in all subsequent communications with that
     server (and not set the upgrade).  Note that the kernel will not
     retain this information should the connection expire from its cache.

 (4) If a server that supports upgrading is replaced by one that doesn't,
     whilst a connection is live, and if the replacement is running, say,
     OpenAFS 1.6.4 or older or an older IBM AFS, then the replacement
     server will not respond to packets sent to the upgraded connection.

     At this point, calls will time out and the server must be reprobed.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-06-05 14:30:49 +01:00

1270 lines
33 KiB
C

/* RxRPC packet reception
*
* Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#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_usage == 0)
goto out;
if (ktime_before(skb->tstamp,
ktime_add_ns(call->cong_tstamp,
call->peer->rtt)))
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;
}
/*
* Ping the other end to fill our RTT cache and to retrieve the rwind
* and MTU parameters.
*/
static void rxrpc_send_ping(struct rxrpc_call *call, struct sk_buff *skb,
int skew)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
ktime_t now = skb->tstamp;
if (call->peer->rtt_usage < 3 ||
ktime_before(ktime_add_ms(call->peer->rtt_last_req, 1000), now))
rxrpc_propose_ACK(call, RXRPC_ACK_PING, skew, sp->hdr.serial,
true, true,
rxrpc_propose_ack_ping_for_params);
}
/*
* Apply a hard ACK by advancing the Tx window.
*/
static void rxrpc_rotate_tx_window(struct rxrpc_call *call, rxrpc_seq_t to,
struct rxrpc_ack_summary *summary)
{
struct sk_buff *skb, *list = NULL;
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_tx_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);
if ((annotation & RXRPC_TX_ANNO_MASK) != RXRPC_TX_ANNO_ACK)
summary->nr_rot_new_acks++;
}
spin_unlock(&call->lock);
trace_rxrpc_transmit(call, (test_bit(RXRPC_CALL_TX_LAST, &call->flags) ?
rxrpc_transmit_rotate_last :
rxrpc_transmit_rotate));
wake_up(&call->waitq);
while (list) {
skb = list;
list = skb->next;
skb->next = NULL;
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
}
}
/*
* 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)
{
ASSERT(test_bit(RXRPC_CALL_TX_LAST, &call->flags));
write_lock(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
if (reply_begun)
call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
else
call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
break;
case RXRPC_CALL_SERVER_AWAIT_ACK:
__rxrpc_call_completed(call);
rxrpc_notify_socket(call);
break;
default:
goto bad_state;
}
write_unlock(&call->state_lock);
if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY) {
rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, 0, false, true,
rxrpc_propose_ack_client_tx_end);
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 };
rxrpc_seq_t top = READ_ONCE(call->tx_top);
if (call->ackr_reason) {
spin_lock_bh(&call->lock);
call->ackr_reason = 0;
call->resend_at = call->expire_at;
call->ack_at = call->expire_at;
spin_unlock_bh(&call->lock);
rxrpc_set_timer(call, rxrpc_timer_init_for_reply,
ktime_get_real());
}
if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags))
rxrpc_rotate_tx_window(call, top, &summary);
if (!test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
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 jumbo 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_jumbo(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;
int nr_jumbo = 1;
u8 flags = sp->hdr.flags;
do {
nr_jumbo++;
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);
} while (flags & RXRPC_JUMBO_PACKET);
sp->nr_jumbo = nr_jumbo;
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,
u8 annotation, bool *_jumbo_bad)
{
/* Discard normal packets that are duplicates. */
if (annotation == 0)
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.
*/
static void rxrpc_input_data(struct rxrpc_call *call, struct sk_buff *skb,
u16 skew)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
enum rxrpc_call_state state;
unsigned int offset = sizeof(struct rxrpc_wire_header);
unsigned int ix;
rxrpc_serial_t serial = sp->hdr.serial, ack_serial = 0;
rxrpc_seq_t seq = sp->hdr.seq, hard_ack;
bool immediate_ack = false, jumbo_bad = false, queued;
u16 len;
u8 ack = 0, flags, annotation = 0;
_enter("{%u,%u},{%u,%u}",
call->rx_hard_ack, call->rx_top, skb->len, seq);
_proto("Rx DATA %%%u { #%u f=%02x }",
sp->hdr.serial, seq, sp->hdr.flags);
state = READ_ONCE(call->state);
if (state >= RXRPC_CALL_COMPLETE)
return;
/* 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))
return;
call->ackr_prev_seq = seq;
hard_ack = READ_ONCE(call->rx_hard_ack);
if (after(seq, hard_ack + call->rx_winsize)) {
ack = RXRPC_ACK_EXCEEDS_WINDOW;
ack_serial = serial;
goto ack;
}
flags = sp->hdr.flags;
if (flags & RXRPC_JUMBO_PACKET) {
if (call->nr_jumbo_bad > 3) {
ack = RXRPC_ACK_NOSPACE;
ack_serial = serial;
goto ack;
}
annotation = 1;
}
next_subpacket:
queued = false;
ix = seq & RXRPC_RXTX_BUFF_MASK;
len = skb->len;
if (flags & RXRPC_JUMBO_PACKET)
len = RXRPC_JUMBO_DATALEN;
if (flags & RXRPC_LAST_PACKET) {
if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
seq != call->rx_top)
return rxrpc_proto_abort("LSN", call, seq);
} else {
if (test_bit(RXRPC_CALL_RX_LAST, &call->flags) &&
after_eq(seq, call->rx_top))
return rxrpc_proto_abort("LSA", call, seq);
}
trace_rxrpc_rx_data(call, seq, serial, flags, annotation);
if (before_eq(seq, hard_ack)) {
ack = RXRPC_ACK_DUPLICATE;
ack_serial = serial;
goto skip;
}
if (flags & RXRPC_REQUEST_ACK && !ack) {
ack = RXRPC_ACK_REQUESTED;
ack_serial = serial;
}
if (call->rxtx_buffer[ix]) {
rxrpc_input_dup_data(call, seq, annotation, &jumbo_bad);
if (ack != RXRPC_ACK_DUPLICATE) {
ack = RXRPC_ACK_DUPLICATE;
ack_serial = serial;
}
immediate_ack = true;
goto skip;
}
/* 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().
*/
rxrpc_get_skb(skb, rxrpc_skb_rx_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 (flags & RXRPC_LAST_PACKET) {
set_bit(RXRPC_CALL_RX_LAST, &call->flags);
trace_rxrpc_receive(call, rxrpc_receive_queue_last, serial, seq);
} else {
trace_rxrpc_receive(call, rxrpc_receive_queue, serial, seq);
}
queued = true;
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;
}
skip:
offset += len;
if (flags & RXRPC_JUMBO_PACKET) {
if (skb_copy_bits(skb, offset, &flags, 1) < 0)
return rxrpc_proto_abort("XJF", call, seq);
offset += sizeof(struct rxrpc_jumbo_header);
seq++;
serial++;
annotation++;
if (flags & RXRPC_JUMBO_PACKET)
annotation |= RXRPC_RX_ANNO_JLAST;
if (after(seq, hard_ack + call->rx_winsize)) {
ack = RXRPC_ACK_EXCEEDS_WINDOW;
ack_serial = serial;
if (!jumbo_bad) {
call->nr_jumbo_bad++;
jumbo_bad = true;
}
goto ack;
}
_proto("Rx DATA Jumbo %%%u", serial);
goto next_subpacket;
}
if (queued && flags & RXRPC_LAST_PACKET && !ack) {
ack = RXRPC_ACK_DELAY;
ack_serial = serial;
}
ack:
if (ack)
rxrpc_propose_ACK(call, ack, skew, ack_serial,
immediate_ack, true,
rxrpc_propose_ack_input_data);
if (sp->hdr.seq == READ_ONCE(call->rx_hard_ack) + 1)
rxrpc_notify_socket(call);
_leave(" [queued]");
}
/*
* Process a requested ACK.
*/
static void rxrpc_input_requested_ack(struct rxrpc_call *call,
ktime_t resp_time,
rxrpc_serial_t orig_serial,
rxrpc_serial_t ack_serial)
{
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
ktime_t sent_at;
int ix;
for (ix = 0; ix < RXRPC_RXTX_BUFF_SIZE; ix++) {
skb = call->rxtx_buffer[ix];
if (!skb)
continue;
sp = rxrpc_skb(skb);
if (sp->hdr.serial != orig_serial)
continue;
smp_rmb();
sent_at = skb->tstamp;
goto found;
}
return;
found:
rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_requested_ack,
orig_serial, ack_serial, sent_at, resp_time);
}
/*
* Process a ping response.
*/
static void rxrpc_input_ping_response(struct rxrpc_call *call,
ktime_t resp_time,
rxrpc_serial_t orig_serial,
rxrpc_serial_t ack_serial)
{
rxrpc_serial_t ping_serial;
ktime_t ping_time;
ping_time = call->ping_time;
smp_rmb();
ping_serial = call->ping_serial;
if (!test_bit(RXRPC_CALL_PINGING, &call->flags) ||
before(orig_serial, ping_serial))
return;
clear_bit(RXRPC_CALL_PINGING, &call->flags);
if (after(orig_serial, ping_serial))
return;
rxrpc_peer_add_rtt(call, rxrpc_rtt_rx_ping_response,
orig_serial, ack_serial, ping_time, resp_time);
}
/*
* 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 (call->tx_winsize != rwind) {
if (rwind > RXRPC_RXTX_BUFF_SIZE - 1)
rwind = RXRPC_RXTX_BUFF_SIZE - 1;
if (rwind > call->tx_winsize)
wake = true;
trace_rxrpc_rx_rwind_change(call, sp->hdr.serial,
ntohl(ackinfo->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);
}
}
}
/*
* 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,
u16 skew)
{
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 acked_serial;
rxrpc_seq_t first_soft_ack, hard_ack;
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);
acked_serial = ntohl(buf.ack.serial);
first_soft_ack = ntohl(buf.ack.firstPacket);
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, sp->hdr.serial, acked_serial,
first_soft_ack, ntohl(buf.ack.previousPacket),
summary.ack_reason, nr_acks);
if (buf.ack.reason == RXRPC_ACK_PING_RESPONSE)
rxrpc_input_ping_response(call, skb->tstamp, acked_serial,
sp->hdr.serial);
if (buf.ack.reason == RXRPC_ACK_REQUESTED)
rxrpc_input_requested_ack(call, skb->tstamp, acked_serial,
sp->hdr.serial);
if (buf.ack.reason == RXRPC_ACK_PING) {
_proto("Rx ACK %%%u PING Request", sp->hdr.serial);
rxrpc_propose_ACK(call, RXRPC_ACK_PING_RESPONSE,
skew, sp->hdr.serial, true, true,
rxrpc_propose_ack_respond_to_ping);
} else if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED,
skew, sp->hdr.serial, true, true,
rxrpc_propose_ack_respond_to_ack);
}
ioffset = offset + nr_acks + 3;
if (skb->len >= ioffset + sizeof(buf.info)) {
if (skb_copy_bits(skb, ioffset, &buf.info, sizeof(buf.info)) < 0)
return rxrpc_proto_abort("XAI", call, 0);
rxrpc_input_ackinfo(call, skb, &buf.info);
}
if (first_soft_ack == 0)
return rxrpc_proto_abort("AK0", call, 0);
/* 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:
return;
}
/* Discard any out-of-order or duplicate ACKs. */
if (before_eq(sp->hdr.serial, call->acks_latest)) {
_debug("discard ACK %d <= %d",
sp->hdr.serial, call->acks_latest);
return;
}
call->acks_latest_ts = skb->tstamp;
call->acks_latest = sp->hdr.serial;
if (before(hard_ack, call->tx_hard_ack) ||
after(hard_ack, call->tx_top))
return rxrpc_proto_abort("AKW", call, 0);
if (nr_acks > call->tx_top - hard_ack)
return rxrpc_proto_abort("AKN", call, 0);
if (after(hard_ack, call->tx_hard_ack))
rxrpc_rotate_tx_window(call, hard_ack, &summary);
if (nr_acks > 0) {
if (skb_copy_bits(skb, offset, buf.acks, nr_acks) < 0)
return rxrpc_proto_abort("XSA", call, 0);
rxrpc_input_soft_acks(call, buf.acks, first_soft_ack, nr_acks,
&summary);
}
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags)) {
rxrpc_end_tx_phase(call, false, "ETA");
return;
}
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, skew, sp->hdr.serial,
false, true,
rxrpc_propose_ack_ping_for_lost_reply);
return rxrpc_congestion_management(call, skb, &summary, acked_serial);
}
/*
* 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);
rxrpc_rotate_tx_window(call, call->tx_top, &summary);
if (test_bit(RXRPC_CALL_TX_LAST, &call->flags))
rxrpc_end_tx_phase(call, false, "ETL");
}
/*
* 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);
if (rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
abort_code, -ECONNABORTED))
rxrpc_notify_socket(call);
}
/*
* Process an incoming call packet.
*/
static void rxrpc_input_call_packet(struct rxrpc_call *call,
struct sk_buff *skb, u16 skew)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
_enter("%p,%p", call, skb);
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_DATA:
rxrpc_input_data(call, skb, skew);
break;
case RXRPC_PACKET_TYPE_ACK:
rxrpc_input_ack(call, skb, skew);
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;
}
_leave("");
}
/*
* Handle a new call on a channel implicitly completing the preceding call on
* that channel.
*
* TODO: If callNumber > call_id + 1, renegotiate security.
*/
static void rxrpc_input_implicit_end_call(struct rxrpc_connection *conn,
struct rxrpc_call *call)
{
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_SERVER_AWAIT_ACK:
rxrpc_call_completed(call);
break;
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);
}
break;
}
trace_rxrpc_improper_term(call);
__rxrpc_disconnect_call(conn, call);
rxrpc_notify_socket(call);
}
/*
* 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);
skb_queue_tail(&local->event_queue, skb);
rxrpc_queue_local(local);
}
/*
* put a packet up for transport-level abort
*/
static void rxrpc_reject_packet(struct rxrpc_local *local, struct sk_buff *skb)
{
CHECK_SLAB_OKAY(&local->usage);
skb_queue_tail(&local->reject_queue, skb);
rxrpc_queue_local(local);
}
/*
* 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
*
* The socket is locked by the caller and this prevents the socket from being
* shut down and the local endpoint from going away, thus sk_user_data will not
* be cleared until this function returns.
*/
void rxrpc_data_ready(struct sock *udp_sk)
{
struct rxrpc_connection *conn;
struct rxrpc_channel *chan;
struct rxrpc_call *call;
struct rxrpc_skb_priv *sp;
struct rxrpc_local *local = udp_sk->sk_user_data;
struct sk_buff *skb;
unsigned int channel;
int ret, skew;
_enter("%p", udp_sk);
ASSERT(!irqs_disabled());
skb = skb_recv_udp(udp_sk, 0, 1, &ret);
if (!skb) {
if (ret == -EAGAIN)
return;
_debug("UDP socket error %d", ret);
return;
}
rxrpc_new_skb(skb, rxrpc_skb_rx_received);
_net("recv skb %p", skb);
/* we'll probably need to checksum it (didn't call sock_recvmsg) */
if (skb_checksum_complete(skb)) {
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
__UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
_leave(" [CSUM failed]");
return;
}
__UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0);
/* 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_lose_skb(skb, rxrpc_skb_rx_lost);
return;
}
}
trace_rxrpc_rx_packet(sp);
_net("Rx RxRPC %s ep=%x call=%x:%x",
sp->hdr.flags & RXRPC_CLIENT_INITIATED ? "ToServer" : "ToClient",
sp->hdr.epoch, sp->hdr.cid, sp->hdr.callNumber);
if (sp->hdr.type >= RXRPC_N_PACKET_TYPES ||
!((RXRPC_SUPPORTED_PACKET_TYPES >> sp->hdr.type) & 1)) {
_proto("Rx Bad Packet Type %u", sp->hdr.type);
goto bad_message;
}
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_VERSION:
rxrpc_post_packet_to_local(local, skb);
goto out;
case RXRPC_PACKET_TYPE_BUSY:
if (sp->hdr.flags & RXRPC_CLIENT_INITIATED)
goto discard;
case RXRPC_PACKET_TYPE_DATA:
if (sp->hdr.callNumber == 0)
goto bad_message;
if (sp->hdr.flags & RXRPC_JUMBO_PACKET &&
!rxrpc_validate_jumbo(skb))
goto bad_message;
break;
}
rcu_read_lock();
conn = rxrpc_find_connection_rcu(local, skb);
if (conn) {
if (sp->hdr.securityIndex != conn->security_ix)
goto wrong_security;
if (sp->hdr.serviceId != conn->service_id) {
if (!test_bit(RXRPC_CONN_PROBING_FOR_UPGRADE, &conn->flags) ||
conn->service_id != conn->params.service_id)
goto reupgrade;
conn->service_id = sp->hdr.serviceId;
}
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_unlock;
}
/* Note the serial number skew here */
skew = (int)sp->hdr.serial - (int)conn->hi_serial;
if (skew >= 0) {
if (skew > 0)
conn->hi_serial = sp->hdr.serial;
} else {
skew = -skew;
skew = min(skew, 65535);
}
/* 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_unlock;
if (sp->hdr.callNumber == chan->last_call) {
/* 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 ||
sp->hdr.type == RXRPC_PACKET_TYPE_ABORT))
goto discard_unlock;
/* But otherwise we need to retransmit the final packet from
* data cached in the connection record.
*/
rxrpc_post_packet_to_conn(conn, skb);
goto out_unlock;
}
call = rcu_dereference(chan->call);
if (sp->hdr.callNumber > chan->call_id) {
if (!(sp->hdr.flags & RXRPC_CLIENT_INITIATED)) {
rcu_read_unlock();
goto reject_packet;
}
if (call)
rxrpc_input_implicit_end_call(conn, call);
call = NULL;
}
if (call && sp->hdr.serviceId != call->service_id)
call->service_id = sp->hdr.serviceId;
} else {
skew = 0;
call = NULL;
}
if (!call || atomic_read(&call->usage) == 0) {
if (!(sp->hdr.type & RXRPC_CLIENT_INITIATED) ||
sp->hdr.callNumber == 0 ||
sp->hdr.type != RXRPC_PACKET_TYPE_DATA)
goto bad_message_unlock;
if (sp->hdr.seq != 1)
goto discard_unlock;
call = rxrpc_new_incoming_call(local, conn, skb);
if (!call) {
rcu_read_unlock();
goto reject_packet;
}
rxrpc_send_ping(call, skb, skew);
mutex_unlock(&call->user_mutex);
}
rxrpc_input_call_packet(call, skb, skew);
goto discard_unlock;
discard_unlock:
rcu_read_unlock();
discard:
rxrpc_free_skb(skb, rxrpc_skb_rx_freed);
out:
trace_rxrpc_rx_done(0, 0);
return;
out_unlock:
rcu_read_unlock();
goto out;
wrong_security:
rcu_read_unlock();
trace_rxrpc_abort("SEC", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RXKADINCONSISTENCY, EBADMSG);
skb->priority = RXKADINCONSISTENCY;
goto post_abort;
reupgrade:
rcu_read_unlock();
trace_rxrpc_abort("UPG", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
RX_PROTOCOL_ERROR, EBADMSG);
goto protocol_error;
bad_message_unlock:
rcu_read_unlock();
bad_message:
trace_rxrpc_abort("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_LOCAL_ABORT;
reject_packet:
trace_rxrpc_rx_done(skb->mark, skb->priority);
rxrpc_reject_packet(local, skb);
_leave(" [badmsg]");
}