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OpenCloudOS-Kernel/net/rxrpc/input.c

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/* RxRPC packet reception
*
* Copyright (C) 2007 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"
/*
* queue a packet for recvmsg to pass to userspace
* - the caller must hold a lock on call->lock
* - must not be called with interrupts disabled (sk_filter() disables BH's)
* - eats the packet whether successful or not
* - there must be just one reference to the packet, which the caller passes to
* this function
*/
int rxrpc_queue_rcv_skb(struct rxrpc_call *call, struct sk_buff *skb,
bool force, bool terminal)
{
struct rxrpc_skb_priv *sp;
struct rxrpc_sock *rx = call->socket;
struct sock *sk;
int ret;
_enter(",,%d,%d", force, terminal);
ASSERT(!irqs_disabled());
sp = rxrpc_skb(skb);
ASSERTCMP(sp->call, ==, call);
/* if we've already posted the terminal message for a call, then we
* don't post any more */
if (test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags)) {
_debug("already terminated");
ASSERTCMP(call->state, >=, RXRPC_CALL_COMPLETE);
rxrpc_free_skb(skb);
return 0;
}
sk = &rx->sk;
if (!force) {
/* cast skb->rcvbuf to unsigned... It's pointless, but
* reduces number of warnings when compiling with -W
* --ANK */
// ret = -ENOBUFS;
// if (atomic_read(&sk->sk_rmem_alloc) + skb->truesize >=
// (unsigned int) sk->sk_rcvbuf)
// goto out;
ret = sk_filter(sk, skb);
if (ret < 0)
goto out;
}
spin_lock_bh(&sk->sk_receive_queue.lock);
if (!test_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags) &&
!test_bit(RXRPC_CALL_RELEASED, &call->flags) &&
call->socket->sk.sk_state != RXRPC_CLOSE) {
skb->destructor = rxrpc_packet_destructor;
skb->dev = NULL;
skb->sk = sk;
atomic_add(skb->truesize, &sk->sk_rmem_alloc);
if (terminal) {
_debug("<<<< TERMINAL MESSAGE >>>>");
set_bit(RXRPC_CALL_TERMINAL_MSG, &call->flags);
}
/* allow interception by a kernel service */
if (rx->interceptor) {
rx->interceptor(sk, call->user_call_ID, skb);
spin_unlock_bh(&sk->sk_receive_queue.lock);
} else {
_net("post skb %p", skb);
__skb_queue_tail(&sk->sk_receive_queue, skb);
spin_unlock_bh(&sk->sk_receive_queue.lock);
if (!sock_flag(sk, SOCK_DEAD))
sk->sk_data_ready(sk);
}
skb = NULL;
} else {
spin_unlock_bh(&sk->sk_receive_queue.lock);
}
ret = 0;
out:
rxrpc_free_skb(skb);
_leave(" = %d", ret);
return ret;
}
/*
* process a DATA packet, posting the packet to the appropriate queue
* - eats the packet if successful
*/
static int rxrpc_fast_process_data(struct rxrpc_call *call,
struct sk_buff *skb, u32 seq)
{
struct rxrpc_skb_priv *sp;
bool terminal;
int ret, ackbit, ack;
u32 serial;
u8 flags;
_enter("{%u,%u},,{%u}", call->rx_data_post, call->rx_first_oos, seq);
sp = rxrpc_skb(skb);
ASSERTCMP(sp->call, ==, NULL);
flags = sp->hdr.flags;
serial = sp->hdr.serial;
spin_lock(&call->lock);
if (call->state > RXRPC_CALL_COMPLETE)
goto discard;
ASSERTCMP(call->rx_data_expect, >=, call->rx_data_post);
ASSERTCMP(call->rx_data_post, >=, call->rx_data_recv);
ASSERTCMP(call->rx_data_recv, >=, call->rx_data_eaten);
if (seq < call->rx_data_post) {
_debug("dup #%u [-%u]", seq, call->rx_data_post);
ack = RXRPC_ACK_DUPLICATE;
ret = -ENOBUFS;
goto discard_and_ack;
}
/* we may already have the packet in the out of sequence queue */
ackbit = seq - (call->rx_data_eaten + 1);
ASSERTCMP(ackbit, >=, 0);
if (__test_and_set_bit(ackbit, call->ackr_window)) {
_debug("dup oos #%u [%u,%u]",
seq, call->rx_data_eaten, call->rx_data_post);
ack = RXRPC_ACK_DUPLICATE;
goto discard_and_ack;
}
if (seq >= call->ackr_win_top) {
_debug("exceed #%u [%u]", seq, call->ackr_win_top);
__clear_bit(ackbit, call->ackr_window);
ack = RXRPC_ACK_EXCEEDS_WINDOW;
goto discard_and_ack;
}
if (seq == call->rx_data_expect) {
clear_bit(RXRPC_CALL_EXPECT_OOS, &call->flags);
call->rx_data_expect++;
} else if (seq > call->rx_data_expect) {
_debug("oos #%u [%u]", seq, call->rx_data_expect);
call->rx_data_expect = seq + 1;
if (test_and_set_bit(RXRPC_CALL_EXPECT_OOS, &call->flags)) {
ack = RXRPC_ACK_OUT_OF_SEQUENCE;
goto enqueue_and_ack;
}
goto enqueue_packet;
}
if (seq != call->rx_data_post) {
_debug("ahead #%u [%u]", seq, call->rx_data_post);
goto enqueue_packet;
}
if (test_bit(RXRPC_CALL_RCVD_LAST, &call->flags))
goto protocol_error;
/* if the packet need security things doing to it, then it goes down
* the slow path */
if (call->conn->security_ix)
goto enqueue_packet;
sp->call = call;
rxrpc_get_call(call);
atomic_inc(&call->skb_count);
terminal = ((flags & RXRPC_LAST_PACKET) &&
!(flags & RXRPC_CLIENT_INITIATED));
ret = rxrpc_queue_rcv_skb(call, skb, false, terminal);
if (ret < 0) {
if (ret == -ENOMEM || ret == -ENOBUFS) {
__clear_bit(ackbit, call->ackr_window);
ack = RXRPC_ACK_NOSPACE;
goto discard_and_ack;
}
goto out;
}
skb = NULL;
sp = NULL;
_debug("post #%u", seq);
ASSERTCMP(call->rx_data_post, ==, seq);
call->rx_data_post++;
if (flags & RXRPC_LAST_PACKET)
set_bit(RXRPC_CALL_RCVD_LAST, &call->flags);
/* if we've reached an out of sequence packet then we need to drain
* that queue into the socket Rx queue now */
if (call->rx_data_post == call->rx_first_oos) {
_debug("drain rx oos now");
read_lock(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE &&
!test_and_set_bit(RXRPC_CALL_EV_DRAIN_RX_OOS, &call->events))
rxrpc_queue_call(call);
read_unlock(&call->state_lock);
}
spin_unlock(&call->lock);
atomic_inc(&call->ackr_not_idle);
rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, serial, false);
_leave(" = 0 [posted]");
return 0;
protocol_error:
ret = -EBADMSG;
out:
spin_unlock(&call->lock);
_leave(" = %d", ret);
return ret;
discard_and_ack:
_debug("discard and ACK packet %p", skb);
__rxrpc_propose_ACK(call, ack, serial, true);
discard:
spin_unlock(&call->lock);
rxrpc_free_skb(skb);
_leave(" = 0 [discarded]");
return 0;
enqueue_and_ack:
__rxrpc_propose_ACK(call, ack, serial, true);
enqueue_packet:
_net("defer skb %p", skb);
spin_unlock(&call->lock);
skb_queue_tail(&call->rx_queue, skb);
atomic_inc(&call->ackr_not_idle);
read_lock(&call->state_lock);
if (call->state < RXRPC_CALL_DEAD)
rxrpc_queue_call(call);
read_unlock(&call->state_lock);
_leave(" = 0 [queued]");
return 0;
}
/*
* assume an implicit ACKALL of the transmission phase of a client socket upon
* reception of the first reply packet
*/
static void rxrpc_assume_implicit_ackall(struct rxrpc_call *call, u32 serial)
{
write_lock_bh(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_AWAIT_REPLY:
call->state = RXRPC_CALL_CLIENT_RECV_REPLY;
call->acks_latest = serial;
_debug("implicit ACKALL %%%u", call->acks_latest);
set_bit(RXRPC_CALL_EV_RCVD_ACKALL, &call->events);
write_unlock_bh(&call->state_lock);
if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
clear_bit(RXRPC_CALL_EV_RESEND_TIMER, &call->events);
clear_bit(RXRPC_CALL_EV_RESEND, &call->events);
clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
}
break;
default:
write_unlock_bh(&call->state_lock);
break;
}
}
/*
* post an incoming packet to the nominated call to deal with
* - must get rid of the sk_buff, either by freeing it or by queuing it
*/
void rxrpc_fast_process_packet(struct rxrpc_call *call, struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
__be32 wtmp;
u32 hi_serial, abort_code;
_enter("%p,%p", call, skb);
ASSERT(!irqs_disabled());
#if 0 // INJECT RX ERROR
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
static int skip = 0;
if (++skip == 3) {
printk("DROPPED 3RD PACKET!!!!!!!!!!!!!\n");
skip = 0;
goto free_packet;
}
}
#endif
/* track the latest serial number on this connection for ACK packet
* information */
hi_serial = atomic_read(&call->conn->hi_serial);
while (sp->hdr.serial > hi_serial)
hi_serial = atomic_cmpxchg(&call->conn->hi_serial, hi_serial,
sp->hdr.serial);
/* request ACK generation for any ACK or DATA packet that requests
* it */
if (sp->hdr.flags & RXRPC_REQUEST_ACK) {
_proto("ACK Requested on %%%u", sp->hdr.serial);
rxrpc_propose_ACK(call, RXRPC_ACK_REQUESTED, sp->hdr.serial, false);
}
switch (sp->hdr.type) {
case RXRPC_PACKET_TYPE_ABORT:
_debug("abort");
if (skb_copy_bits(skb, 0, &wtmp, sizeof(wtmp)) < 0)
goto protocol_error;
abort_code = ntohl(wtmp);
_proto("Rx ABORT %%%u { %x }", sp->hdr.serial, abort_code);
write_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_COMPLETE) {
call->state = RXRPC_CALL_REMOTELY_ABORTED;
call->remote_abort = abort_code;
set_bit(RXRPC_CALL_EV_RCVD_ABORT, &call->events);
rxrpc_queue_call(call);
}
goto free_packet_unlock;
case RXRPC_PACKET_TYPE_BUSY:
_proto("Rx BUSY %%%u", sp->hdr.serial);
if (rxrpc_conn_is_service(call->conn))
goto protocol_error;
write_lock_bh(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
call->state = RXRPC_CALL_SERVER_BUSY;
set_bit(RXRPC_CALL_EV_RCVD_BUSY, &call->events);
rxrpc_queue_call(call);
case RXRPC_CALL_SERVER_BUSY:
goto free_packet_unlock;
default:
goto protocol_error_locked;
}
default:
_proto("Rx %s %%%u", rxrpc_pkts[sp->hdr.type], sp->hdr.serial);
goto protocol_error;
case RXRPC_PACKET_TYPE_DATA:
_proto("Rx DATA %%%u { #%u }", sp->hdr.serial, sp->hdr.seq);
if (sp->hdr.seq == 0)
goto protocol_error;
call->ackr_prev_seq = sp->hdr.seq;
/* received data implicitly ACKs all of the request packets we
* sent when we're acting as a client */
if (call->state == RXRPC_CALL_CLIENT_AWAIT_REPLY)
rxrpc_assume_implicit_ackall(call, sp->hdr.serial);
switch (rxrpc_fast_process_data(call, skb, sp->hdr.seq)) {
case 0:
skb = NULL;
goto done;
default:
BUG();
/* data packet received beyond the last packet */
case -EBADMSG:
goto protocol_error;
}
case RXRPC_PACKET_TYPE_ACKALL:
case RXRPC_PACKET_TYPE_ACK:
/* ACK processing is done in process context */
read_lock_bh(&call->state_lock);
if (call->state < RXRPC_CALL_DEAD) {
skb_queue_tail(&call->rx_queue, skb);
rxrpc_queue_call(call);
skb = NULL;
}
read_unlock_bh(&call->state_lock);
goto free_packet;
}
protocol_error:
_debug("protocol error");
write_lock_bh(&call->state_lock);
protocol_error_locked:
if (call->state <= RXRPC_CALL_COMPLETE) {
call->state = RXRPC_CALL_LOCALLY_ABORTED;
call->local_abort = RX_PROTOCOL_ERROR;
set_bit(RXRPC_CALL_EV_ABORT, &call->events);
rxrpc_queue_call(call);
}
free_packet_unlock:
write_unlock_bh(&call->state_lock);
free_packet:
rxrpc_free_skb(skb);
done:
_leave("");
}
/*
* split up a jumbo data packet
*/
static void rxrpc_process_jumbo_packet(struct rxrpc_call *call,
struct sk_buff *jumbo)
{
struct rxrpc_jumbo_header jhdr;
struct rxrpc_skb_priv *sp;
struct sk_buff *part;
_enter(",{%u,%u}", jumbo->data_len, jumbo->len);
sp = rxrpc_skb(jumbo);
do {
sp->hdr.flags &= ~RXRPC_JUMBO_PACKET;
/* make a clone to represent the first subpacket in what's left
* of the jumbo packet */
part = skb_clone(jumbo, GFP_ATOMIC);
if (!part) {
/* simply ditch the tail in the event of ENOMEM */
pskb_trim(jumbo, RXRPC_JUMBO_DATALEN);
break;
}
rxrpc_new_skb(part);
pskb_trim(part, RXRPC_JUMBO_DATALEN);
if (!pskb_pull(jumbo, RXRPC_JUMBO_DATALEN))
goto protocol_error;
if (skb_copy_bits(jumbo, 0, &jhdr, sizeof(jhdr)) < 0)
goto protocol_error;
if (!pskb_pull(jumbo, sizeof(jhdr)))
BUG();
sp->hdr.seq += 1;
sp->hdr.serial += 1;
sp->hdr.flags = jhdr.flags;
sp->hdr._rsvd = ntohs(jhdr._rsvd);
_proto("Rx DATA Jumbo %%%u", sp->hdr.serial - 1);
rxrpc_fast_process_packet(call, part);
part = NULL;
} while (sp->hdr.flags & RXRPC_JUMBO_PACKET);
rxrpc_fast_process_packet(call, jumbo);
_leave("");
return;
protocol_error:
_debug("protocol error");
rxrpc_free_skb(part);
rxrpc_free_skb(jumbo);
write_lock_bh(&call->state_lock);
if (call->state <= RXRPC_CALL_COMPLETE) {
call->state = RXRPC_CALL_LOCALLY_ABORTED;
call->local_abort = RX_PROTOCOL_ERROR;
set_bit(RXRPC_CALL_EV_ABORT, &call->events);
rxrpc_queue_call(call);
}
write_unlock_bh(&call->state_lock);
_leave("");
}
/*
* post an incoming packet to the appropriate call/socket to deal with
* - must get rid of the sk_buff, either by freeing it or by queuing it
*/
static void rxrpc_post_packet_to_call(struct rxrpc_call *call,
struct sk_buff *skb)
{
struct rxrpc_skb_priv *sp;
_enter("%p,%p", call, skb);
sp = rxrpc_skb(skb);
_debug("extant call [%d]", call->state);
read_lock(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_LOCALLY_ABORTED:
if (!test_and_set_bit(RXRPC_CALL_EV_ABORT, &call->events)) {
rxrpc_queue_call(call);
goto free_unlock;
}
case RXRPC_CALL_REMOTELY_ABORTED:
case RXRPC_CALL_NETWORK_ERROR:
case RXRPC_CALL_DEAD:
goto dead_call;
case RXRPC_CALL_COMPLETE:
case RXRPC_CALL_CLIENT_FINAL_ACK:
/* complete server call */
if (rxrpc_conn_is_service(call->conn))
goto dead_call;
/* resend last packet of a completed call */
_debug("final ack again");
rxrpc_get_call(call);
set_bit(RXRPC_CALL_EV_ACK_FINAL, &call->events);
rxrpc_queue_call(call);
goto free_unlock;
default:
break;
}
read_unlock(&call->state_lock);
rxrpc_get_call(call);
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
sp->hdr.flags & RXRPC_JUMBO_PACKET)
rxrpc_process_jumbo_packet(call, skb);
else
rxrpc_fast_process_packet(call, skb);
rxrpc_put_call(call);
goto done;
dead_call:
if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
skb->priority = RX_CALL_DEAD;
rxrpc_reject_packet(call->conn->params.local, skb);
goto unlock;
}
free_unlock:
rxrpc_free_skb(skb);
unlock:
read_unlock(&call->state_lock);
done:
_leave("");
}
/*
* post connection-level events to the connection
* - this includes challenges, responses and some aborts
*/
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);
}
/*
* 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)
return -EBADMSG;
if (!pskb_pull(skb, sizeof(whdr)))
BUG();
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 *sk)
{
struct rxrpc_connection *conn;
struct rxrpc_skb_priv *sp;
struct rxrpc_local *local = sk->sk_user_data;
struct sk_buff *skb;
int ret;
_enter("%p", sk);
ASSERT(!irqs_disabled());
skb = skb_recv_datagram(sk, 0, 1, &ret);
if (!skb) {
if (ret == -EAGAIN)
return;
_debug("UDP socket error %d", ret);
return;
}
rxrpc_new_skb(skb);
_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);
__UDP_INC_STATS(&init_net, UDP_MIB_INERRORS, 0);
_leave(" [CSUM failed]");
return;
}
__UDP_INC_STATS(&init_net, UDP_MIB_INDATAGRAMS, 0);
/* The socket buffer we have is owned by UDP, with UDP's data all over
* it, but we really want our own data there.
*/
skb_orphan(skb);
sp = rxrpc_skb(skb);
_net("Rx UDP packet from %08x:%04hu",
ntohl(ip_hdr(skb)->saddr), ntohs(udp_hdr(skb)->source));
/* dig out the RxRPC connection details */
if (rxrpc_extract_header(sp, skb) < 0)
goto bad_message;
_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;
}
if (sp->hdr.type == RXRPC_PACKET_TYPE_VERSION) {
rxrpc_post_packet_to_local(local, skb);
goto out;
}
if (sp->hdr.type == RXRPC_PACKET_TYPE_DATA &&
(sp->hdr.callNumber == 0 || sp->hdr.seq == 0))
goto bad_message;
rcu_read_lock();
conn = rxrpc_find_connection_rcu(local, skb);
if (!conn)
goto cant_route_call;
if (sp->hdr.callNumber == 0) {
/* Connection-level packet */
_debug("CONN %p {%d}", conn, conn->debug_id);
rxrpc_post_packet_to_conn(conn, skb);
} else {
/* Call-bound packets are routed by connection channel. */
unsigned int channel = sp->hdr.cid & RXRPC_CHANNELMASK;
struct rxrpc_channel *chan = &conn->channels[channel];
struct rxrpc_call *call = rcu_dereference(chan->call);
if (!call || atomic_read(&call->usage) == 0)
goto cant_route_call;
rxrpc_post_packet_to_call(call, skb);
}
rcu_read_unlock();
out:
return;
cant_route_call:
rcu_read_unlock();
_debug("can't route call");
if (sp->hdr.flags & RXRPC_CLIENT_INITIATED &&
sp->hdr.type == RXRPC_PACKET_TYPE_DATA) {
if (sp->hdr.seq == 1) {
_debug("first packet");
skb_queue_tail(&local->accept_queue, skb);
rxrpc_queue_work(&local->processor);
_leave(" [incoming]");
return;
}
skb->priority = RX_INVALID_OPERATION;
} else {
skb->priority = RX_CALL_DEAD;
}
if (sp->hdr.type != RXRPC_PACKET_TYPE_ABORT) {
_debug("reject type %d",sp->hdr.type);
rxrpc_reject_packet(local, skb);
} else {
rxrpc_free_skb(skb);
}
_leave(" [no call]");
return;
bad_message:
skb->priority = RX_PROTOCOL_ERROR;
rxrpc_reject_packet(local, skb);
_leave(" [badmsg]");
}
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