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linux/net/tipc/socket.c
Allan Stephens cfb0c0890b [TIPC]: Optimize wakeup logic when socket has no waiting processes 
This patch adds a simple test so TIPC doesn't try waking up processes
waiting on a socket if there are none waiting.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2006-10-18 19:55:17 -07:00

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/*
* net/tipc/socket.c: TIPC socket API
*
* Copyright (c) 2001-2006, Ericsson AB
* Copyright (c) 2004-2006, Wind River Systems
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the names of the copyright holders nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/net.h>
#include <linux/socket.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/poll.h>
#include <linux/fcntl.h>
#include <asm/semaphore.h>
#include <asm/string.h>
#include <asm/atomic.h>
#include <net/sock.h>
#include <linux/tipc.h>
#include <linux/tipc_config.h>
#include <net/tipc/tipc_msg.h>
#include <net/tipc/tipc_port.h>
#include "core.h"
#define SS_LISTENING -1 /* socket is listening */
#define SS_READY -2 /* socket is connectionless */
#define OVERLOAD_LIMIT_BASE 5000
struct tipc_sock {
struct sock sk;
struct tipc_port *p;
struct semaphore sem;
};
#define tipc_sk(sk) ((struct tipc_sock*)sk)
static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf);
static void wakeupdispatch(struct tipc_port *tport);
static struct proto_ops packet_ops;
static struct proto_ops stream_ops;
static struct proto_ops msg_ops;
static struct proto tipc_proto;
static int sockets_enabled = 0;
static atomic_t tipc_queue_size = ATOMIC_INIT(0);
/*
* sock_lock(): Lock a port/socket pair. lock_sock() can
* not be used here, since the same lock must protect ports
* with non-socket interfaces.
* See net.c for description of locking policy.
*/
static void sock_lock(struct tipc_sock* tsock)
{
spin_lock_bh(tsock->p->lock);
}
/*
* sock_unlock(): Unlock a port/socket pair
*/
static void sock_unlock(struct tipc_sock* tsock)
{
spin_unlock_bh(tsock->p->lock);
}
/**
* pollmask - determine the current set of poll() events for a socket
* @sock: socket structure
*
* TIPC sets the returned events as follows:
* a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty
* or if a connection-oriented socket is does not have an active connection
* (i.e. a read operation will not block).
* b) POLLOUT is set except when a socket's connection has been terminated
* (i.e. a write operation will not block).
* c) POLLHUP is set when a socket's connection has been terminated.
*
* IMPORTANT: The fact that a read or write operation will not block does NOT
* imply that the operation will succeed!
*
* Returns pollmask value
*/
static u32 pollmask(struct socket *sock)
{
u32 mask;
if ((skb_queue_len(&sock->sk->sk_receive_queue) != 0) ||
(sock->state == SS_UNCONNECTED) ||
(sock->state == SS_DISCONNECTING))
mask = (POLLRDNORM | POLLIN);
else
mask = 0;
if (sock->state == SS_DISCONNECTING)
mask |= POLLHUP;
else
mask |= POLLOUT;
return mask;
}
/**
* advance_queue - discard first buffer in queue
* @tsock: TIPC socket
*/
static void advance_queue(struct tipc_sock *tsock)
{
sock_lock(tsock);
buf_discard(skb_dequeue(&tsock->sk.sk_receive_queue));
sock_unlock(tsock);
atomic_dec(&tipc_queue_size);
}
/**
* tipc_create - create a TIPC socket
* @sock: pre-allocated socket structure
* @protocol: protocol indicator (must be 0)
*
* This routine creates and attaches a 'struct sock' to the 'struct socket',
* then create and attaches a TIPC port to the 'struct sock' part.
*
* Returns 0 on success, errno otherwise
*/
static int tipc_create(struct socket *sock, int protocol)
{
struct tipc_sock *tsock;
struct tipc_port *port;
struct sock *sk;
u32 ref;
if (unlikely(protocol != 0))
return -EPROTONOSUPPORT;
ref = tipc_createport_raw(NULL, &dispatch, &wakeupdispatch, TIPC_LOW_IMPORTANCE);
if (unlikely(!ref))
return -ENOMEM;
sock->state = SS_UNCONNECTED;
switch (sock->type) {
case SOCK_STREAM:
sock->ops = &stream_ops;
break;
case SOCK_SEQPACKET:
sock->ops = &packet_ops;
break;
case SOCK_DGRAM:
tipc_set_portunreliable(ref, 1);
/* fall through */
case SOCK_RDM:
tipc_set_portunreturnable(ref, 1);
sock->ops = &msg_ops;
sock->state = SS_READY;
break;
default:
tipc_deleteport(ref);
return -EPROTOTYPE;
}
sk = sk_alloc(AF_TIPC, GFP_KERNEL, &tipc_proto, 1);
if (!sk) {
tipc_deleteport(ref);
return -ENOMEM;
}
sock_init_data(sock, sk);
init_waitqueue_head(sk->sk_sleep);
sk->sk_rcvtimeo = 8 * HZ; /* default connect timeout = 8s */
tsock = tipc_sk(sk);
port = tipc_get_port(ref);
tsock->p = port;
port->usr_handle = tsock;
init_MUTEX(&tsock->sem);
dbg("sock_create: %x\n",tsock);
atomic_inc(&tipc_user_count);
return 0;
}
/**
* release - destroy a TIPC socket
* @sock: socket to destroy
*
* This routine cleans up any messages that are still queued on the socket.
* For DGRAM and RDM socket types, all queued messages are rejected.
* For SEQPACKET and STREAM socket types, the first message is rejected
* and any others are discarded. (If the first message on a STREAM socket
* is partially-read, it is discarded and the next one is rejected instead.)
*
* NOTE: Rejected messages are not necessarily returned to the sender! They
* are returned or discarded according to the "destination droppable" setting
* specified for the message by the sender.
*
* Returns 0 on success, errno otherwise
*/
static int release(struct socket *sock)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sock *sk = sock->sk;
int res = TIPC_OK;
struct sk_buff *buf;
dbg("sock_delete: %x\n",tsock);
if (!tsock)
return 0;
down_interruptible(&tsock->sem);
if (!sock->sk) {
up(&tsock->sem);
return 0;
}
/* Reject unreceived messages, unless no longer connected */
while (sock->state != SS_DISCONNECTING) {
sock_lock(tsock);
buf = skb_dequeue(&sk->sk_receive_queue);
if (!buf)
tsock->p->usr_handle = NULL;
sock_unlock(tsock);
if (!buf)
break;
if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf)))
buf_discard(buf);
else
tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
atomic_dec(&tipc_queue_size);
}
/* Delete TIPC port */
res = tipc_deleteport(tsock->p->ref);
sock->sk = NULL;
/* Discard any remaining messages */
while ((buf = skb_dequeue(&sk->sk_receive_queue))) {
buf_discard(buf);
atomic_dec(&tipc_queue_size);
}
up(&tsock->sem);
sock_put(sk);
atomic_dec(&tipc_user_count);
return res;
}
/**
* bind - associate or disassocate TIPC name(s) with a socket
* @sock: socket structure
* @uaddr: socket address describing name(s) and desired operation
* @uaddr_len: size of socket address data structure
*
* Name and name sequence binding is indicated using a positive scope value;
* a negative scope value unbinds the specified name. Specifying no name
* (i.e. a socket address length of 0) unbinds all names from the socket.
*
* Returns 0 on success, errno otherwise
*/
static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
int res;
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
if (unlikely(!uaddr_len)) {
res = tipc_withdraw(tsock->p->ref, 0, NULL);
goto exit;
}
if (uaddr_len < sizeof(struct sockaddr_tipc)) {
res = -EINVAL;
goto exit;
}
if (addr->family != AF_TIPC) {
res = -EAFNOSUPPORT;
goto exit;
}
if (addr->addrtype == TIPC_ADDR_NAME)
addr->addr.nameseq.upper = addr->addr.nameseq.lower;
else if (addr->addrtype != TIPC_ADDR_NAMESEQ) {
res = -EAFNOSUPPORT;
goto exit;
}
if (addr->scope > 0)
res = tipc_publish(tsock->p->ref, addr->scope,
&addr->addr.nameseq);
else
res = tipc_withdraw(tsock->p->ref, -addr->scope,
&addr->addr.nameseq);
exit:
up(&tsock->sem);
return res;
}
/**
* get_name - get port ID of socket or peer socket
* @sock: socket structure
* @uaddr: area for returned socket address
* @uaddr_len: area for returned length of socket address
* @peer: 0 to obtain socket name, 1 to obtain peer socket name
*
* Returns 0 on success, errno otherwise
*/
static int get_name(struct socket *sock, struct sockaddr *uaddr,
int *uaddr_len, int peer)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
u32 res;
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
*uaddr_len = sizeof(*addr);
addr->addrtype = TIPC_ADDR_ID;
addr->family = AF_TIPC;
addr->scope = 0;
if (peer)
res = tipc_peer(tsock->p->ref, &addr->addr.id);
else
res = tipc_ownidentity(tsock->p->ref, &addr->addr.id);
addr->addr.name.domain = 0;
up(&tsock->sem);
return res;
}
/**
* poll - read and possibly block on pollmask
* @file: file structure associated with the socket
* @sock: socket for which to calculate the poll bits
* @wait: ???
*
* Returns the pollmask
*/
static unsigned int poll(struct file *file, struct socket *sock,
poll_table *wait)
{
poll_wait(file, sock->sk->sk_sleep, wait);
/* NEED LOCK HERE? */
return pollmask(sock);
}
/**
* dest_name_check - verify user is permitted to send to specified port name
* @dest: destination address
* @m: descriptor for message to be sent
*
* Prevents restricted configuration commands from being issued by
* unauthorized users.
*
* Returns 0 if permission is granted, otherwise errno
*/
static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m)
{
struct tipc_cfg_msg_hdr hdr;
if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES))
return 0;
if (likely(dest->addr.name.name.type == TIPC_TOP_SRV))
return 0;
if (likely(dest->addr.name.name.type != TIPC_CFG_SRV))
return -EACCES;
if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr)))
return -EFAULT;
if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN)))
return -EACCES;
return 0;
}
/**
* send_msg - send message in connectionless manner
* @iocb: (unused)
* @sock: socket structure
* @m: message to send
* @total_len: length of message
*
* Message must have an destination specified explicitly.
* Used for SOCK_RDM and SOCK_DGRAM messages,
* and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections.
* (Note: 'SYN+' is prohibited on SOCK_STREAM.)
*
* Returns the number of bytes sent on success, or errno otherwise
*/
static int send_msg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
struct sk_buff *buf;
int needs_conn;
int res = -EINVAL;
if (unlikely(!dest))
return -EDESTADDRREQ;
if (unlikely((m->msg_namelen < sizeof(*dest)) ||
(dest->family != AF_TIPC)))
return -EINVAL;
needs_conn = (sock->state != SS_READY);
if (unlikely(needs_conn)) {
if (sock->state == SS_LISTENING)
return -EPIPE;
if (sock->state != SS_UNCONNECTED)
return -EISCONN;
if ((tsock->p->published) ||
((sock->type == SOCK_STREAM) && (total_len != 0)))
return -EOPNOTSUPP;
if (dest->addrtype == TIPC_ADDR_NAME) {
tsock->p->conn_type = dest->addr.name.name.type;
tsock->p->conn_instance = dest->addr.name.name.instance;
}
}
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
if (needs_conn) {
/* Abort any pending connection attempts (very unlikely) */
while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
atomic_dec(&tipc_queue_size);
}
sock->state = SS_CONNECTING;
}
do {
if (dest->addrtype == TIPC_ADDR_NAME) {
if ((res = dest_name_check(dest, m)))
goto exit;
res = tipc_send2name(tsock->p->ref,
&dest->addr.name.name,
dest->addr.name.domain,
m->msg_iovlen,
m->msg_iov);
}
else if (dest->addrtype == TIPC_ADDR_ID) {
res = tipc_send2port(tsock->p->ref,
&dest->addr.id,
m->msg_iovlen,
m->msg_iov);
}
else if (dest->addrtype == TIPC_ADDR_MCAST) {
if (needs_conn) {
res = -EOPNOTSUPP;
goto exit;
}
if ((res = dest_name_check(dest, m)))
goto exit;
res = tipc_multicast(tsock->p->ref,
&dest->addr.nameseq,
0,
m->msg_iovlen,
m->msg_iov);
}
if (likely(res != -ELINKCONG)) {
exit:
up(&tsock->sem);
return res;
}
if (m->msg_flags & MSG_DONTWAIT) {
res = -EWOULDBLOCK;
goto exit;
}
if (wait_event_interruptible(*sock->sk->sk_sleep,
!tsock->p->congested)) {
res = -ERESTARTSYS;
goto exit;
}
} while (1);
}
/**
* send_packet - send a connection-oriented message
* @iocb: (unused)
* @sock: socket structure
* @m: message to send
* @total_len: length of message
*
* Used for SOCK_SEQPACKET messages and SOCK_STREAM data.
*
* Returns the number of bytes sent on success, or errno otherwise
*/
static int send_packet(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
int res;
/* Handle implied connection establishment */
if (unlikely(dest))
return send_msg(iocb, sock, m, total_len);
if (down_interruptible(&tsock->sem)) {
return -ERESTARTSYS;
}
do {
if (unlikely(sock->state != SS_CONNECTED)) {
if (sock->state == SS_DISCONNECTING)
res = -EPIPE;
else
res = -ENOTCONN;
goto exit;
}
res = tipc_send(tsock->p->ref, m->msg_iovlen, m->msg_iov);
if (likely(res != -ELINKCONG)) {
exit:
up(&tsock->sem);
return res;
}
if (m->msg_flags & MSG_DONTWAIT) {
res = -EWOULDBLOCK;
goto exit;
}
if (wait_event_interruptible(*sock->sk->sk_sleep,
!tsock->p->congested)) {
res = -ERESTARTSYS;
goto exit;
}
} while (1);
}
/**
* send_stream - send stream-oriented data
* @iocb: (unused)
* @sock: socket structure
* @m: data to send
* @total_len: total length of data to be sent
*
* Used for SOCK_STREAM data.
*
* Returns the number of bytes sent on success (or partial success),
* or errno if no data sent
*/
static int send_stream(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t total_len)
{
struct msghdr my_msg;
struct iovec my_iov;
struct iovec *curr_iov;
int curr_iovlen;
char __user *curr_start;
int curr_left;
int bytes_to_send;
int bytes_sent;
int res;
if (likely(total_len <= TIPC_MAX_USER_MSG_SIZE))
return send_packet(iocb, sock, m, total_len);
/* Can only send large data streams if already connected */
if (unlikely(sock->state != SS_CONNECTED)) {
if (sock->state == SS_DISCONNECTING)
return -EPIPE;
else
return -ENOTCONN;
}
if (unlikely(m->msg_name))
return -EISCONN;
/*
* Send each iovec entry using one or more messages
*
* Note: This algorithm is good for the most likely case
* (i.e. one large iovec entry), but could be improved to pass sets
* of small iovec entries into send_packet().
*/
curr_iov = m->msg_iov;
curr_iovlen = m->msg_iovlen;
my_msg.msg_iov = &my_iov;
my_msg.msg_iovlen = 1;
my_msg.msg_flags = m->msg_flags;
my_msg.msg_name = NULL;
bytes_sent = 0;
while (curr_iovlen--) {
curr_start = curr_iov->iov_base;
curr_left = curr_iov->iov_len;
while (curr_left) {
bytes_to_send = (curr_left < TIPC_MAX_USER_MSG_SIZE)
? curr_left : TIPC_MAX_USER_MSG_SIZE;
my_iov.iov_base = curr_start;
my_iov.iov_len = bytes_to_send;
if ((res = send_packet(iocb, sock, &my_msg, 0)) < 0) {
return bytes_sent ? bytes_sent : res;
}
curr_left -= bytes_to_send;
curr_start += bytes_to_send;
bytes_sent += bytes_to_send;
}
curr_iov++;
}
return bytes_sent;
}
/**
* auto_connect - complete connection setup to a remote port
* @sock: socket structure
* @tsock: TIPC-specific socket structure
* @msg: peer's response message
*
* Returns 0 on success, errno otherwise
*/
static int auto_connect(struct socket *sock, struct tipc_sock *tsock,
struct tipc_msg *msg)
{
struct tipc_portid peer;
if (msg_errcode(msg)) {
sock->state = SS_DISCONNECTING;
return -ECONNREFUSED;
}
peer.ref = msg_origport(msg);
peer.node = msg_orignode(msg);
tipc_connect2port(tsock->p->ref, &peer);
tipc_set_portimportance(tsock->p->ref, msg_importance(msg));
sock->state = SS_CONNECTED;
return 0;
}
/**
* set_orig_addr - capture sender's address for received message
* @m: descriptor for message info
* @msg: received message header
*
* Note: Address is not captured if not requested by receiver.
*/
static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
{
struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
if (addr) {
addr->family = AF_TIPC;
addr->addrtype = TIPC_ADDR_ID;
addr->addr.id.ref = msg_origport(msg);
addr->addr.id.node = msg_orignode(msg);
addr->addr.name.domain = 0; /* could leave uninitialized */
addr->scope = 0; /* could leave uninitialized */
m->msg_namelen = sizeof(struct sockaddr_tipc);
}
}
/**
* anc_data_recv - optionally capture ancillary data for received message
* @m: descriptor for message info
* @msg: received message header
* @tport: TIPC port associated with message
*
* Note: Ancillary data is not captured if not requested by receiver.
*
* Returns 0 if successful, otherwise errno
*/
static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
struct tipc_port *tport)
{
u32 anc_data[3];
u32 err;
u32 dest_type;
int has_name;
int res;
if (likely(m->msg_controllen == 0))
return 0;
/* Optionally capture errored message object(s) */
err = msg ? msg_errcode(msg) : 0;
if (unlikely(err)) {
anc_data[0] = err;
anc_data[1] = msg_data_sz(msg);
if ((res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data)))
return res;
if (anc_data[1] &&
(res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
msg_data(msg))))
return res;
}
/* Optionally capture message destination object */
dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
switch (dest_type) {
case TIPC_NAMED_MSG:
has_name = 1;
anc_data[0] = msg_nametype(msg);
anc_data[1] = msg_namelower(msg);
anc_data[2] = msg_namelower(msg);
break;
case TIPC_MCAST_MSG:
has_name = 1;
anc_data[0] = msg_nametype(msg);
anc_data[1] = msg_namelower(msg);
anc_data[2] = msg_nameupper(msg);
break;
case TIPC_CONN_MSG:
has_name = (tport->conn_type != 0);
anc_data[0] = tport->conn_type;
anc_data[1] = tport->conn_instance;
anc_data[2] = tport->conn_instance;
break;
default:
has_name = 0;
}
if (has_name &&
(res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data)))
return res;
return 0;
}
/**
* recv_msg - receive packet-oriented message
* @iocb: (unused)
* @m: descriptor for message info
* @buf_len: total size of user buffer area
* @flags: receive flags
*
* Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
* If the complete message doesn't fit in user area, truncate it.
*
* Returns size of returned message data, errno otherwise
*/
static int recv_msg(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t buf_len, int flags)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sk_buff *buf;
struct tipc_msg *msg;
unsigned int q_len;
unsigned int sz;
u32 err;
int res;
/* Currently doesn't support receiving into multiple iovec entries */
if (m->msg_iovlen != 1)
return -EOPNOTSUPP;
/* Catch invalid receive attempts */
if (unlikely(!buf_len))
return -EINVAL;
if (sock->type == SOCK_SEQPACKET) {
if (unlikely(sock->state == SS_UNCONNECTED))
return -ENOTCONN;
if (unlikely((sock->state == SS_DISCONNECTING) &&
(skb_queue_len(&sock->sk->sk_receive_queue) == 0)))
return -ENOTCONN;
}
/* Look for a message in receive queue; wait if necessary */
if (unlikely(down_interruptible(&tsock->sem)))
return -ERESTARTSYS;
restart:
if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
(flags & MSG_DONTWAIT))) {
res = -EWOULDBLOCK;
goto exit;
}
if ((res = wait_event_interruptible(
*sock->sk->sk_sleep,
((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) ||
(sock->state == SS_DISCONNECTING))) )) {
goto exit;
}
/* Catch attempt to receive on an already terminated connection */
/* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */
if (!q_len) {
res = -ENOTCONN;
goto exit;
}
/* Get access to first message in receive queue */
buf = skb_peek(&sock->sk->sk_receive_queue);
msg = buf_msg(buf);
sz = msg_data_sz(msg);
err = msg_errcode(msg);
/* Complete connection setup for an implied connect */
if (unlikely(sock->state == SS_CONNECTING)) {
if ((res = auto_connect(sock, tsock, msg)))
goto exit;
}
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
advance_queue(tsock);
goto restart;
}
/* Capture sender's address (optional) */
set_orig_addr(m, msg);
/* Capture ancillary data (optional) */
if ((res = anc_data_recv(m, msg, tsock->p)))
goto exit;
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
if (unlikely(buf_len < sz)) {
sz = buf_len;
m->msg_flags |= MSG_TRUNC;
}
if (unlikely(copy_to_user(m->msg_iov->iov_base, msg_data(msg),
sz))) {
res = -EFAULT;
goto exit;
}
res = sz;
} else {
if ((sock->state == SS_READY) ||
((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
res = 0;
else
res = -ECONNRESET;
}
/* Consume received message (optional) */
if (likely(!(flags & MSG_PEEK))) {
if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked);
advance_queue(tsock);
}
exit:
up(&tsock->sem);
return res;
}
/**
* recv_stream - receive stream-oriented data
* @iocb: (unused)
* @m: descriptor for message info
* @buf_len: total size of user buffer area
* @flags: receive flags
*
* Used for SOCK_STREAM messages only. If not enough data is available
* will optionally wait for more; never truncates data.
*
* Returns size of returned message data, errno otherwise
*/
static int recv_stream(struct kiocb *iocb, struct socket *sock,
struct msghdr *m, size_t buf_len, int flags)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sk_buff *buf;
struct tipc_msg *msg;
unsigned int q_len;
unsigned int sz;
int sz_to_copy;
int sz_copied = 0;
int needed;
char __user *crs = m->msg_iov->iov_base;
unsigned char *buf_crs;
u32 err;
int res;
/* Currently doesn't support receiving into multiple iovec entries */
if (m->msg_iovlen != 1)
return -EOPNOTSUPP;
/* Catch invalid receive attempts */
if (unlikely(!buf_len))
return -EINVAL;
if (unlikely(sock->state == SS_DISCONNECTING)) {
if (skb_queue_len(&sock->sk->sk_receive_queue) == 0)
return -ENOTCONN;
} else if (unlikely(sock->state != SS_CONNECTED))
return -ENOTCONN;
/* Look for a message in receive queue; wait if necessary */
if (unlikely(down_interruptible(&tsock->sem)))
return -ERESTARTSYS;
restart:
if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
(flags & MSG_DONTWAIT))) {
res = -EWOULDBLOCK;
goto exit;
}
if ((res = wait_event_interruptible(
*sock->sk->sk_sleep,
((q_len = skb_queue_len(&sock->sk->sk_receive_queue)) ||
(sock->state == SS_DISCONNECTING))) )) {
goto exit;
}
/* Catch attempt to receive on an already terminated connection */
/* [THIS CHECK MAY OVERLAP WITH AN EARLIER CHECK] */
if (!q_len) {
res = -ENOTCONN;
goto exit;
}
/* Get access to first message in receive queue */
buf = skb_peek(&sock->sk->sk_receive_queue);
msg = buf_msg(buf);
sz = msg_data_sz(msg);
err = msg_errcode(msg);
/* Discard an empty non-errored message & try again */
if ((!sz) && (!err)) {
advance_queue(tsock);
goto restart;
}
/* Optionally capture sender's address & ancillary data of first msg */
if (sz_copied == 0) {
set_orig_addr(m, msg);
if ((res = anc_data_recv(m, msg, tsock->p)))
goto exit;
}
/* Capture message data (if valid) & compute return value (always) */
if (!err) {
buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
sz = buf->tail - buf_crs;
needed = (buf_len - sz_copied);
sz_to_copy = (sz <= needed) ? sz : needed;
if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) {
res = -EFAULT;
goto exit;
}
sz_copied += sz_to_copy;
if (sz_to_copy < sz) {
if (!(flags & MSG_PEEK))
TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy;
goto exit;
}
crs += sz_to_copy;
} else {
if (sz_copied != 0)
goto exit; /* can't add error msg to valid data */
if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
res = 0;
else
res = -ECONNRESET;
}
/* Consume received message (optional) */
if (likely(!(flags & MSG_PEEK))) {
if (unlikely(++tsock->p->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
tipc_acknowledge(tsock->p->ref, tsock->p->conn_unacked);
advance_queue(tsock);
}
/* Loop around if more data is required */
if ((sz_copied < buf_len) /* didn't get all requested data */
&& (flags & MSG_WAITALL) /* ... and need to wait for more */
&& (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */
&& (!err) /* ... and haven't reached a FIN */
)
goto restart;
exit:
up(&tsock->sem);
return sz_copied ? sz_copied : res;
}
/**
* queue_overloaded - test if queue overload condition exists
* @queue_size: current size of queue
* @base: nominal maximum size of queue
* @msg: message to be added to queue
*
* Returns 1 if queue is currently overloaded, 0 otherwise
*/
static int queue_overloaded(u32 queue_size, u32 base, struct tipc_msg *msg)
{
u32 threshold;
u32 imp = msg_importance(msg);
if (imp == TIPC_LOW_IMPORTANCE)
threshold = base;
else if (imp == TIPC_MEDIUM_IMPORTANCE)
threshold = base * 2;
else if (imp == TIPC_HIGH_IMPORTANCE)
threshold = base * 100;
else
return 0;
if (msg_connected(msg))
threshold *= 4;
return (queue_size > threshold);
}
/**
* async_disconnect - wrapper function used to disconnect port
* @portref: TIPC port reference (passed as pointer-sized value)
*/
static void async_disconnect(unsigned long portref)
{
tipc_disconnect((u32)portref);
}
/**
* dispatch - handle arriving message
* @tport: TIPC port that received message
* @buf: message
*
* Called with port locked. Must not take socket lock to avoid deadlock risk.
*
* Returns TIPC error status code (TIPC_OK if message is not to be rejected)
*/
static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf)
{
struct tipc_msg *msg = buf_msg(buf);
struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle;
struct socket *sock;
u32 recv_q_len;
/* Reject message if socket is closing */
if (!tsock)
return TIPC_ERR_NO_PORT;
/* Reject message if it is wrong sort of message for socket */
/*
* WOULD IT BE BETTER TO JUST DISCARD THESE MESSAGES INSTEAD?
* "NO PORT" ISN'T REALLY THE RIGHT ERROR CODE, AND THERE MAY
* BE SECURITY IMPLICATIONS INHERENT IN REJECTING INVALID TRAFFIC
*/
sock = tsock->sk.sk_socket;
if (sock->state == SS_READY) {
if (msg_connected(msg)) {
msg_dbg(msg, "dispatch filter 1\n");
return TIPC_ERR_NO_PORT;
}
} else {
if (msg_mcast(msg)) {
msg_dbg(msg, "dispatch filter 2\n");
return TIPC_ERR_NO_PORT;
}
if (sock->state == SS_CONNECTED) {
if (!msg_connected(msg)) {
msg_dbg(msg, "dispatch filter 3\n");
return TIPC_ERR_NO_PORT;
}
}
else if (sock->state == SS_CONNECTING) {
if (!msg_connected(msg) && (msg_errcode(msg) == 0)) {
msg_dbg(msg, "dispatch filter 4\n");
return TIPC_ERR_NO_PORT;
}
}
else if (sock->state == SS_LISTENING) {
if (msg_connected(msg) || msg_errcode(msg)) {
msg_dbg(msg, "dispatch filter 5\n");
return TIPC_ERR_NO_PORT;
}
}
else if (sock->state == SS_DISCONNECTING) {
msg_dbg(msg, "dispatch filter 6\n");
return TIPC_ERR_NO_PORT;
}
else /* (sock->state == SS_UNCONNECTED) */ {
if (msg_connected(msg) || msg_errcode(msg)) {
msg_dbg(msg, "dispatch filter 7\n");
return TIPC_ERR_NO_PORT;
}
}
}
/* Reject message if there isn't room to queue it */
if (unlikely((u32)atomic_read(&tipc_queue_size) >
OVERLOAD_LIMIT_BASE)) {
if (queue_overloaded(atomic_read(&tipc_queue_size),
OVERLOAD_LIMIT_BASE, msg))
return TIPC_ERR_OVERLOAD;
}
recv_q_len = skb_queue_len(&tsock->sk.sk_receive_queue);
if (unlikely(recv_q_len > (OVERLOAD_LIMIT_BASE / 2))) {
if (queue_overloaded(recv_q_len,
OVERLOAD_LIMIT_BASE / 2, msg))
return TIPC_ERR_OVERLOAD;
}
/* Initiate connection termination for an incoming 'FIN' */
if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) {
sock->state = SS_DISCONNECTING;
/* Note: Use signal since port lock is already taken! */
tipc_k_signal((Handler)async_disconnect, tport->ref);
}
/* Enqueue message (finally!) */
msg_dbg(msg,"<DISP<: ");
TIPC_SKB_CB(buf)->handle = msg_data(msg);
atomic_inc(&tipc_queue_size);
skb_queue_tail(&sock->sk->sk_receive_queue, buf);
if (waitqueue_active(sock->sk->sk_sleep))
wake_up_interruptible(sock->sk->sk_sleep);
return TIPC_OK;
}
/**
* wakeupdispatch - wake up port after congestion
* @tport: port to wakeup
*
* Called with port lock on.
*/
static void wakeupdispatch(struct tipc_port *tport)
{
struct tipc_sock *tsock = (struct tipc_sock *)tport->usr_handle;
if (waitqueue_active(tsock->sk.sk_sleep))
wake_up_interruptible(tsock->sk.sk_sleep);
}
/**
* connect - establish a connection to another TIPC port
* @sock: socket structure
* @dest: socket address for destination port
* @destlen: size of socket address data structure
* @flags: (unused)
*
* Returns 0 on success, errno otherwise
*/
static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
int flags)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
struct msghdr m = {NULL,};
struct sk_buff *buf;
struct tipc_msg *msg;
int res;
/* For now, TIPC does not allow use of connect() with DGRAM or RDM types */
if (sock->state == SS_READY)
return -EOPNOTSUPP;
/* Issue Posix-compliant error code if socket is in the wrong state */
if (sock->state == SS_LISTENING)
return -EOPNOTSUPP;
if (sock->state == SS_CONNECTING)
return -EALREADY;
if (sock->state != SS_UNCONNECTED)
return -EISCONN;
/*
* Reject connection attempt using multicast address
*
* Note: send_msg() validates the rest of the address fields,
* so there's no need to do it here
*/
if (dst->addrtype == TIPC_ADDR_MCAST)
return -EINVAL;
/* Send a 'SYN-' to destination */
m.msg_name = dest;
m.msg_namelen = destlen;
if ((res = send_msg(NULL, sock, &m, 0)) < 0) {
sock->state = SS_DISCONNECTING;
return res;
}
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
/* Wait for destination's 'ACK' response */
res = wait_event_interruptible_timeout(*sock->sk->sk_sleep,
skb_queue_len(&sock->sk->sk_receive_queue),
sock->sk->sk_rcvtimeo);
buf = skb_peek(&sock->sk->sk_receive_queue);
if (res > 0) {
msg = buf_msg(buf);
res = auto_connect(sock, tsock, msg);
if (!res) {
if (!msg_data_sz(msg))
advance_queue(tsock);
}
} else {
if (res == 0) {
res = -ETIMEDOUT;
} else
{ /* leave "res" unchanged */ }
sock->state = SS_DISCONNECTING;
}
up(&tsock->sem);
return res;
}
/**
* listen - allow socket to listen for incoming connections
* @sock: socket structure
* @len: (unused)
*
* Returns 0 on success, errno otherwise
*/
static int listen(struct socket *sock, int len)
{
/* REQUIRES SOCKET LOCKING OF SOME SORT? */
if (sock->state == SS_READY)
return -EOPNOTSUPP;
if (sock->state != SS_UNCONNECTED)
return -EINVAL;
sock->state = SS_LISTENING;
return 0;
}
/**
* accept - wait for connection request
* @sock: listening socket
* @newsock: new socket that is to be connected
* @flags: file-related flags associated with socket
*
* Returns 0 on success, errno otherwise
*/
static int accept(struct socket *sock, struct socket *newsock, int flags)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
struct sk_buff *buf;
int res = -EFAULT;
if (sock->state == SS_READY)
return -EOPNOTSUPP;
if (sock->state != SS_LISTENING)
return -EINVAL;
if (unlikely((skb_queue_len(&sock->sk->sk_receive_queue) == 0) &&
(flags & O_NONBLOCK)))
return -EWOULDBLOCK;
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
if (wait_event_interruptible(*sock->sk->sk_sleep,
skb_queue_len(&sock->sk->sk_receive_queue))) {
res = -ERESTARTSYS;
goto exit;
}
buf = skb_peek(&sock->sk->sk_receive_queue);
res = tipc_create(newsock, 0);
if (!res) {
struct tipc_sock *new_tsock = tipc_sk(newsock->sk);
struct tipc_portid id;
struct tipc_msg *msg = buf_msg(buf);
u32 new_ref = new_tsock->p->ref;
id.ref = msg_origport(msg);
id.node = msg_orignode(msg);
tipc_connect2port(new_ref, &id);
newsock->state = SS_CONNECTED;
tipc_set_portimportance(new_ref, msg_importance(msg));
if (msg_named(msg)) {
new_tsock->p->conn_type = msg_nametype(msg);
new_tsock->p->conn_instance = msg_nameinst(msg);
}
/*
* Respond to 'SYN-' by discarding it & returning 'ACK'-.
* Respond to 'SYN+' by queuing it on new socket.
*/
msg_dbg(msg,"<ACC<: ");
if (!msg_data_sz(msg)) {
struct msghdr m = {NULL,};
send_packet(NULL, newsock, &m, 0);
advance_queue(tsock);
} else {
sock_lock(tsock);
skb_dequeue(&sock->sk->sk_receive_queue);
sock_unlock(tsock);
skb_queue_head(&newsock->sk->sk_receive_queue, buf);
}
}
exit:
up(&tsock->sem);
return res;
}
/**
* shutdown - shutdown socket connection
* @sock: socket structure
* @how: direction to close (unused; always treated as read + write)
*
* Terminates connection (if necessary), then purges socket's receive queue.
*
* Returns 0 on success, errno otherwise
*/
static int shutdown(struct socket *sock, int how)
{
struct tipc_sock* tsock = tipc_sk(sock->sk);
struct sk_buff *buf;
int res;
/* Could return -EINVAL for an invalid "how", but why bother? */
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
sock_lock(tsock);
switch (sock->state) {
case SS_CONNECTED:
/* Send 'FIN+' or 'FIN-' message to peer */
sock_unlock(tsock);
restart:
if ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
atomic_dec(&tipc_queue_size);
if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) {
buf_discard(buf);
goto restart;
}
tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
}
else {
tipc_shutdown(tsock->p->ref);
}
sock_lock(tsock);
/* fall through */
case SS_DISCONNECTING:
/* Discard any unreceived messages */
while ((buf = skb_dequeue(&sock->sk->sk_receive_queue))) {
atomic_dec(&tipc_queue_size);
buf_discard(buf);
}
tsock->p->conn_unacked = 0;
/* fall through */
case SS_CONNECTING:
sock->state = SS_DISCONNECTING;
res = 0;
break;
default:
res = -ENOTCONN;
}
sock_unlock(tsock);
up(&tsock->sem);
return res;
}
/**
* setsockopt - set socket option
* @sock: socket structure
* @lvl: option level
* @opt: option identifier
* @ov: pointer to new option value
* @ol: length of option value
*
* For stream sockets only, accepts and ignores all IPPROTO_TCP options
* (to ease compatibility).
*
* Returns 0 on success, errno otherwise
*/
static int setsockopt(struct socket *sock,
int lvl, int opt, char __user *ov, int ol)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
u32 value;
int res;
if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
return 0;
if (lvl != SOL_TIPC)
return -ENOPROTOOPT;
if (ol < sizeof(value))
return -EINVAL;
if ((res = get_user(value, (u32 __user *)ov)))
return res;
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
switch (opt) {
case TIPC_IMPORTANCE:
res = tipc_set_portimportance(tsock->p->ref, value);
break;
case TIPC_SRC_DROPPABLE:
if (sock->type != SOCK_STREAM)
res = tipc_set_portunreliable(tsock->p->ref, value);
else
res = -ENOPROTOOPT;
break;
case TIPC_DEST_DROPPABLE:
res = tipc_set_portunreturnable(tsock->p->ref, value);
break;
case TIPC_CONN_TIMEOUT:
sock->sk->sk_rcvtimeo = (value * HZ / 1000);
break;
default:
res = -EINVAL;
}
up(&tsock->sem);
return res;
}
/**
* getsockopt - get socket option
* @sock: socket structure
* @lvl: option level
* @opt: option identifier
* @ov: receptacle for option value
* @ol: receptacle for length of option value
*
* For stream sockets only, returns 0 length result for all IPPROTO_TCP options
* (to ease compatibility).
*
* Returns 0 on success, errno otherwise
*/
static int getsockopt(struct socket *sock,
int lvl, int opt, char __user *ov, int __user *ol)
{
struct tipc_sock *tsock = tipc_sk(sock->sk);
int len;
u32 value;
int res;
if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
return put_user(0, ol);
if (lvl != SOL_TIPC)
return -ENOPROTOOPT;
if ((res = get_user(len, ol)))
return res;
if (down_interruptible(&tsock->sem))
return -ERESTARTSYS;
switch (opt) {
case TIPC_IMPORTANCE:
res = tipc_portimportance(tsock->p->ref, &value);
break;
case TIPC_SRC_DROPPABLE:
res = tipc_portunreliable(tsock->p->ref, &value);
break;
case TIPC_DEST_DROPPABLE:
res = tipc_portunreturnable(tsock->p->ref, &value);
break;
case TIPC_CONN_TIMEOUT:
value = (sock->sk->sk_rcvtimeo * 1000) / HZ;
break;
default:
res = -EINVAL;
}
if (res) {
/* "get" failed */
}
else if (len < sizeof(value)) {
res = -EINVAL;
}
else if ((res = copy_to_user(ov, &value, sizeof(value)))) {
/* couldn't return value */
}
else {
res = put_user(sizeof(value), ol);
}
up(&tsock->sem);
return res;
}
/**
* Placeholders for non-implemented functionality
*
* Returns error code (POSIX-compliant where defined)
*/
static int ioctl(struct socket *s, u32 cmd, unsigned long arg)
{
return -EINVAL;
}
static int no_mmap(struct file *file, struct socket *sock,
struct vm_area_struct *vma)
{
return -EINVAL;
}
static ssize_t no_sendpage(struct socket *sock, struct page *page,
int offset, size_t size, int flags)
{
return -EINVAL;
}
static int no_skpair(struct socket *s1, struct socket *s2)
{
return -EOPNOTSUPP;
}
/**
* Protocol switches for the various types of TIPC sockets
*/
static struct proto_ops msg_ops = {
.owner = THIS_MODULE,
.family = AF_TIPC,
.release = release,
.bind = bind,
.connect = connect,
.socketpair = no_skpair,
.accept = accept,
.getname = get_name,
.poll = poll,
.ioctl = ioctl,
.listen = listen,
.shutdown = shutdown,
.setsockopt = setsockopt,
.getsockopt = getsockopt,
.sendmsg = send_msg,
.recvmsg = recv_msg,
.mmap = no_mmap,
.sendpage = no_sendpage
};
static struct proto_ops packet_ops = {
.owner = THIS_MODULE,
.family = AF_TIPC,
.release = release,
.bind = bind,
.connect = connect,
.socketpair = no_skpair,
.accept = accept,
.getname = get_name,
.poll = poll,
.ioctl = ioctl,
.listen = listen,
.shutdown = shutdown,
.setsockopt = setsockopt,
.getsockopt = getsockopt,
.sendmsg = send_packet,
.recvmsg = recv_msg,
.mmap = no_mmap,
.sendpage = no_sendpage
};
static struct proto_ops stream_ops = {
.owner = THIS_MODULE,
.family = AF_TIPC,
.release = release,
.bind = bind,
.connect = connect,
.socketpair = no_skpair,
.accept = accept,
.getname = get_name,
.poll = poll,
.ioctl = ioctl,
.listen = listen,
.shutdown = shutdown,
.setsockopt = setsockopt,
.getsockopt = getsockopt,
.sendmsg = send_stream,
.recvmsg = recv_stream,
.mmap = no_mmap,
.sendpage = no_sendpage
};
static struct net_proto_family tipc_family_ops = {
.owner = THIS_MODULE,
.family = AF_TIPC,
.create = tipc_create
};
static struct proto tipc_proto = {
.name = "TIPC",
.owner = THIS_MODULE,
.obj_size = sizeof(struct tipc_sock)
};
/**
* tipc_socket_init - initialize TIPC socket interface
*
* Returns 0 on success, errno otherwise
*/
int tipc_socket_init(void)
{
int res;
res = proto_register(&tipc_proto, 1);
if (res) {
err("Failed to register TIPC protocol type\n");
goto out;
}
res = sock_register(&tipc_family_ops);
if (res) {
err("Failed to register TIPC socket type\n");
proto_unregister(&tipc_proto);
goto out;
}
sockets_enabled = 1;
out:
return res;
}
/**
* tipc_socket_stop - stop TIPC socket interface
*/
void tipc_socket_stop(void)
{
if (!sockets_enabled)
return;
sockets_enabled = 0;
sock_unregister(tipc_family_ops.family);
proto_unregister(&tipc_proto);
}
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