blob: 96ffa5d5733bd73249e32e2c10a420af9946e9b2 [file] [log] [blame]
/* AF_RXRPC sendmsg() implementation.
*
* 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 Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/net.h>
#include <linux/gfp.h>
#include <linux/skbuff.h>
#include <linux/export.h>
#include <linux/sched/signal.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>
#include "ar-internal.h"
enum rxrpc_command {
RXRPC_CMD_SEND_DATA, /* send data message */
RXRPC_CMD_SEND_ABORT, /* request abort generation */
RXRPC_CMD_ACCEPT, /* [server] accept incoming call */
RXRPC_CMD_REJECT_BUSY, /* [server] reject a call as busy */
};
/*
* wait for space to appear in the transmit/ACK window
* - caller holds the socket locked
*/
static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
struct rxrpc_call *call,
long *timeo)
{
DECLARE_WAITQUEUE(myself, current);
int ret;
_enter(",{%u,%u,%u}",
call->tx_hard_ack, call->tx_top, call->tx_winsize);
add_wait_queue(&call->waitq, &myself);
for (;;) {
set_current_state(TASK_INTERRUPTIBLE);
ret = 0;
if (call->tx_top - call->tx_hard_ack <
min_t(unsigned int, call->tx_winsize,
call->cong_cwnd + call->cong_extra))
break;
if (call->state >= RXRPC_CALL_COMPLETE) {
ret = -call->error;
break;
}
if (signal_pending(current)) {
ret = sock_intr_errno(*timeo);
break;
}
trace_rxrpc_transmit(call, rxrpc_transmit_wait);
mutex_unlock(&call->user_mutex);
*timeo = schedule_timeout(*timeo);
if (mutex_lock_interruptible(&call->user_mutex) < 0) {
ret = sock_intr_errno(*timeo);
break;
}
}
remove_wait_queue(&call->waitq, &myself);
set_current_state(TASK_RUNNING);
_leave(" = %d", ret);
return ret;
}
/*
* Schedule an instant Tx resend.
*/
static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
{
spin_lock_bh(&call->lock);
if (call->state < RXRPC_CALL_COMPLETE) {
call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
rxrpc_queue_call(call);
}
spin_unlock_bh(&call->lock);
}
/*
* Queue a DATA packet for transmission, set the resend timeout and send the
* packet immediately
*/
static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
bool last)
{
struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
rxrpc_seq_t seq = sp->hdr.seq;
int ret, ix;
u8 annotation = RXRPC_TX_ANNO_UNACK;
_net("queue skb %p [%d]", skb, seq);
ASSERTCMP(seq, ==, call->tx_top + 1);
if (last)
annotation |= RXRPC_TX_ANNO_LAST;
/* We have to set the timestamp before queueing as the retransmit
* algorithm can see the packet as soon as we queue it.
*/
skb->tstamp = ktime_get_real();
ix = seq & RXRPC_RXTX_BUFF_MASK;
rxrpc_get_skb(skb, rxrpc_skb_tx_got);
call->rxtx_annotations[ix] = annotation;
smp_wmb();
call->rxtx_buffer[ix] = skb;
call->tx_top = seq;
if (last)
trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
else
trace_rxrpc_transmit(call, rxrpc_transmit_queue);
if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
_debug("________awaiting reply/ACK__________");
write_lock_bh(&call->state_lock);
switch (call->state) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
break;
case RXRPC_CALL_SERVER_ACK_REQUEST:
call->state = RXRPC_CALL_SERVER_SEND_REPLY;
call->ack_at = call->expire_at;
if (call->ackr_reason == RXRPC_ACK_DELAY)
call->ackr_reason = 0;
__rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,
ktime_get_real());
if (!last)
break;
case RXRPC_CALL_SERVER_SEND_REPLY:
call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
break;
default:
break;
}
write_unlock_bh(&call->state_lock);
}
if (seq == 1 && rxrpc_is_client_call(call))
rxrpc_expose_client_call(call);
ret = rxrpc_send_data_packet(call, skb, false);
if (ret < 0) {
_debug("need instant resend %d", ret);
rxrpc_instant_resend(call, ix);
} else {
ktime_t now = ktime_get_real(), resend_at;
resend_at = ktime_add_ms(now, rxrpc_resend_timeout);
if (ktime_before(resend_at, call->resend_at)) {
call->resend_at = resend_at;
rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);
}
}
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
_leave("");
}
/*
* send data through a socket
* - must be called in process context
* - The caller holds the call user access mutex, but not the socket lock.
*/
static int rxrpc_send_data(struct rxrpc_sock *rx,
struct rxrpc_call *call,
struct msghdr *msg, size_t len)
{
struct rxrpc_skb_priv *sp;
struct sk_buff *skb;
struct sock *sk = &rx->sk;
long timeo;
bool more;
int ret, copied;
timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
/* this should be in poll */
sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
return -EPIPE;
more = msg->msg_flags & MSG_MORE;
skb = call->tx_pending;
call->tx_pending = NULL;
rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
copied = 0;
do {
/* Check to see if there's a ping ACK to reply to. */
if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
rxrpc_send_ack_packet(call, false);
if (!skb) {
size_t size, chunk, max, space;
_debug("alloc");
if (call->tx_top - call->tx_hard_ack >=
min_t(unsigned int, call->tx_winsize,
call->cong_cwnd + call->cong_extra)) {
ret = -EAGAIN;
if (msg->msg_flags & MSG_DONTWAIT)
goto maybe_error;
ret = rxrpc_wait_for_tx_window(rx, call,
&timeo);
if (ret < 0)
goto maybe_error;
}
max = RXRPC_JUMBO_DATALEN;
max -= call->conn->security_size;
max &= ~(call->conn->size_align - 1UL);
chunk = max;
if (chunk > msg_data_left(msg) && !more)
chunk = msg_data_left(msg);
space = chunk + call->conn->size_align;
space &= ~(call->conn->size_align - 1UL);
size = space + call->conn->security_size;
_debug("SIZE: %zu/%zu/%zu", chunk, space, size);
/* create a buffer that we can retain until it's ACK'd */
skb = sock_alloc_send_skb(
sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
if (!skb)
goto maybe_error;
rxrpc_new_skb(skb, rxrpc_skb_tx_new);
_debug("ALLOC SEND %p", skb);
ASSERTCMP(skb->mark, ==, 0);
_debug("HS: %u", call->conn->security_size);
skb_reserve(skb, call->conn->security_size);
skb->len += call->conn->security_size;
sp = rxrpc_skb(skb);
sp->remain = chunk;
if (sp->remain > skb_tailroom(skb))
sp->remain = skb_tailroom(skb);
_net("skb: hr %d, tr %d, hl %d, rm %d",
skb_headroom(skb),
skb_tailroom(skb),
skb_headlen(skb),
sp->remain);
skb->ip_summed = CHECKSUM_UNNECESSARY;
}
_debug("append");
sp = rxrpc_skb(skb);
/* append next segment of data to the current buffer */
if (msg_data_left(msg) > 0) {
int copy = skb_tailroom(skb);
ASSERTCMP(copy, >, 0);
if (copy > msg_data_left(msg))
copy = msg_data_left(msg);
if (copy > sp->remain)
copy = sp->remain;
_debug("add");
ret = skb_add_data(skb, &msg->msg_iter, copy);
_debug("added");
if (ret < 0)
goto efault;
sp->remain -= copy;
skb->mark += copy;
copied += copy;
}
/* check for the far side aborting the call or a network error
* occurring */
if (call->state == RXRPC_CALL_COMPLETE)
goto call_terminated;
/* add the packet to the send queue if it's now full */
if (sp->remain <= 0 ||
(msg_data_left(msg) == 0 && !more)) {
struct rxrpc_connection *conn = call->conn;
uint32_t seq;
size_t pad;
/* pad out if we're using security */
if (conn->security_ix) {
pad = conn->security_size + skb->mark;
pad = conn->size_align - pad;
pad &= conn->size_align - 1;
_debug("pad %zu", pad);
if (pad)
memset(skb_put(skb, pad), 0, pad);
}
seq = call->tx_top + 1;
sp->hdr.seq = seq;
sp->hdr._rsvd = 0;
sp->hdr.flags = conn->out_clientflag;
if (msg_data_left(msg) == 0 && !more)
sp->hdr.flags |= RXRPC_LAST_PACKET;
else if (call->tx_top - call->tx_hard_ack <
call->tx_winsize)
sp->hdr.flags |= RXRPC_MORE_PACKETS;
ret = conn->security->secure_packet(
call, skb, skb->mark, skb->head);
if (ret < 0)
goto out;
rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
skb = NULL;
}
} while (msg_data_left(msg) > 0);
success:
ret = copied;
out:
call->tx_pending = skb;
_leave(" = %d", ret);
return ret;
call_terminated:
rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
_leave(" = %d", -call->error);
return -call->error;
maybe_error:
if (copied)
goto success;
goto out;
efault:
ret = -EFAULT;
goto out;
}
/*
* extract control messages from the sendmsg() control buffer
*/
static int rxrpc_sendmsg_cmsg(struct msghdr *msg,
unsigned long *user_call_ID,
enum rxrpc_command *command,
u32 *abort_code,
bool *_exclusive)
{
struct cmsghdr *cmsg;
bool got_user_ID = false;
int len;
*command = RXRPC_CMD_SEND_DATA;
if (msg->msg_controllen == 0)
return -EINVAL;
for_each_cmsghdr(cmsg, msg) {
if (!CMSG_OK(msg, cmsg))
return -EINVAL;
len = cmsg->cmsg_len - sizeof(struct cmsghdr);
_debug("CMSG %d, %d, %d",
cmsg->cmsg_level, cmsg->cmsg_type, len);
if (cmsg->cmsg_level != SOL_RXRPC)
continue;
switch (cmsg->cmsg_type) {
case RXRPC_USER_CALL_ID:
if (msg->msg_flags & MSG_CMSG_COMPAT) {
if (len != sizeof(u32))
return -EINVAL;
*user_call_ID = *(u32 *) CMSG_DATA(cmsg);
} else {
if (len != sizeof(unsigned long))
return -EINVAL;
*user_call_ID = *(unsigned long *)
CMSG_DATA(cmsg);
}
_debug("User Call ID %lx", *user_call_ID);
got_user_ID = true;
break;
case RXRPC_ABORT:
if (*command != RXRPC_CMD_SEND_DATA)
return -EINVAL;
*command = RXRPC_CMD_SEND_ABORT;
if (len != sizeof(*abort_code))
return -EINVAL;
*abort_code = *(unsigned int *) CMSG_DATA(cmsg);
_debug("Abort %x", *abort_code);
if (*abort_code == 0)
return -EINVAL;
break;
case RXRPC_ACCEPT:
if (*command != RXRPC_CMD_SEND_DATA)
return -EINVAL;
*command = RXRPC_CMD_ACCEPT;
if (len != 0)
return -EINVAL;
break;
case RXRPC_EXCLUSIVE_CALL:
*_exclusive = true;
if (len != 0)
return -EINVAL;
break;
default:
return -EINVAL;
}
}
if (!got_user_ID)
return -EINVAL;
_leave(" = 0");
return 0;
}
/*
* Create a new client call for sendmsg().
* - Called with the socket lock held, which it must release.
* - If it returns a call, the call's lock will need releasing by the caller.
*/
static struct rxrpc_call *
rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
unsigned long user_call_ID, bool exclusive)
__releases(&rx->sk.sk_lock.slock)
{
struct rxrpc_conn_parameters cp;
struct rxrpc_call *call;
struct key *key;
DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
_enter("");
if (!msg->msg_name) {
release_sock(&rx->sk);
return ERR_PTR(-EDESTADDRREQ);
}
key = rx->key;
if (key && !rx->key->payload.data[0])
key = NULL;
memset(&cp, 0, sizeof(cp));
cp.local = rx->local;
cp.key = rx->key;
cp.security_level = rx->min_sec_level;
cp.exclusive = rx->exclusive | exclusive;
cp.service_id = srx->srx_service;
call = rxrpc_new_client_call(rx, &cp, srx, user_call_ID, GFP_KERNEL);
/* The socket is now unlocked */
_leave(" = %p\n", call);
return call;
}
/*
* send a message forming part of a client call through an RxRPC socket
* - caller holds the socket locked
* - the socket may be either a client socket or a server socket
*/
int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
__releases(&rx->sk.sk_lock.slock)
{
enum rxrpc_call_state state;
enum rxrpc_command cmd;
struct rxrpc_call *call;
unsigned long user_call_ID = 0;
bool exclusive = false;
u32 abort_code = 0;
int ret;
_enter("");
ret = rxrpc_sendmsg_cmsg(msg, &user_call_ID, &cmd, &abort_code,
&exclusive);
if (ret < 0)
goto error_release_sock;
if (cmd == RXRPC_CMD_ACCEPT) {
ret = -EINVAL;
if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
goto error_release_sock;
call = rxrpc_accept_call(rx, user_call_ID, NULL);
/* The socket is now unlocked. */
if (IS_ERR(call))
return PTR_ERR(call);
rxrpc_put_call(call, rxrpc_call_put);
return 0;
}
call = rxrpc_find_call_by_user_ID(rx, user_call_ID);
if (!call) {
ret = -EBADSLT;
if (cmd != RXRPC_CMD_SEND_DATA)
goto error_release_sock;
call = rxrpc_new_client_call_for_sendmsg(rx, msg, user_call_ID,
exclusive);
/* The socket is now unlocked... */
if (IS_ERR(call))
return PTR_ERR(call);
/* ... and we have the call lock. */
} else {
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_UNINITIALISED:
case RXRPC_CALL_CLIENT_AWAIT_CONN:
case RXRPC_CALL_SERVER_PREALLOC:
case RXRPC_CALL_SERVER_SECURING:
case RXRPC_CALL_SERVER_ACCEPTING:
ret = -EBUSY;
goto error_release_sock;
default:
break;
}
ret = mutex_lock_interruptible(&call->user_mutex);
release_sock(&rx->sk);
if (ret < 0) {
ret = -ERESTARTSYS;
goto error_put;
}
}
state = READ_ONCE(call->state);
_debug("CALL %d USR %lx ST %d on CONN %p",
call->debug_id, call->user_call_ID, state, call->conn);
if (state >= RXRPC_CALL_COMPLETE) {
/* it's too late for this call */
ret = -ESHUTDOWN;
} else if (cmd == RXRPC_CMD_SEND_ABORT) {
ret = 0;
if (rxrpc_abort_call("CMD", call, 0, abort_code, -ECONNABORTED))
ret = rxrpc_send_abort_packet(call);
} else if (cmd != RXRPC_CMD_SEND_DATA) {
ret = -EINVAL;
} else if (rxrpc_is_client_call(call) &&
state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
/* request phase complete for this client call */
ret = -EPROTO;
} else if (rxrpc_is_service_call(call) &&
state != RXRPC_CALL_SERVER_ACK_REQUEST &&
state != RXRPC_CALL_SERVER_SEND_REPLY) {
/* Reply phase not begun or not complete for service call. */
ret = -EPROTO;
} else {
ret = rxrpc_send_data(rx, call, msg, len);
}
mutex_unlock(&call->user_mutex);
error_put:
rxrpc_put_call(call, rxrpc_call_put);
_leave(" = %d", ret);
return ret;
error_release_sock:
release_sock(&rx->sk);
return ret;
}
/**
* rxrpc_kernel_send_data - Allow a kernel service to send data on a call
* @sock: The socket the call is on
* @call: The call to send data through
* @msg: The data to send
* @len: The amount of data to send
*
* Allow a kernel service to send data on a call. The call must be in an state
* appropriate to sending data. No control data should be supplied in @msg,
* nor should an address be supplied. MSG_MORE should be flagged if there's
* more data to come, otherwise this data will end the transmission phase.
*/
int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
struct msghdr *msg, size_t len)
{
int ret;
_enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
ASSERTCMP(msg->msg_name, ==, NULL);
ASSERTCMP(msg->msg_control, ==, NULL);
mutex_lock(&call->user_mutex);
_debug("CALL %d USR %lx ST %d on CONN %p",
call->debug_id, call->user_call_ID, call->state, call->conn);
switch (READ_ONCE(call->state)) {
case RXRPC_CALL_CLIENT_SEND_REQUEST:
case RXRPC_CALL_SERVER_ACK_REQUEST:
case RXRPC_CALL_SERVER_SEND_REPLY:
ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
break;
case RXRPC_CALL_COMPLETE:
read_lock_bh(&call->state_lock);
ret = -call->error;
read_unlock_bh(&call->state_lock);
break;
default:
/* Request phase complete for this client call */
trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
ret = -EPROTO;
break;
}
mutex_unlock(&call->user_mutex);
_leave(" = %d", ret);
return ret;
}
EXPORT_SYMBOL(rxrpc_kernel_send_data);
/**
* rxrpc_kernel_abort_call - Allow a kernel service to abort a call
* @sock: The socket the call is on
* @call: The call to be aborted
* @abort_code: The abort code to stick into the ABORT packet
* @error: Local error value
* @why: 3-char string indicating why.
*
* Allow a kernel service to abort a call, if it's still in an abortable state
* and return true if the call was aborted, false if it was already complete.
*/
bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
u32 abort_code, int error, const char *why)
{
bool aborted;
_enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
mutex_lock(&call->user_mutex);
aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
if (aborted)
rxrpc_send_abort_packet(call);
mutex_unlock(&call->user_mutex);
return aborted;
}
EXPORT_SYMBOL(rxrpc_kernel_abort_call);