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freebsd/sys/netinet/sctp_peeloff.c
Robert Watson 265de5bb62 Correct two problems relating to sorflush(), which is called to flush
read socket buffers in shutdown() and close():

- Call socantrcvmore() before sblock() to dislodge any threads that
  might be sleeping (potentially indefinitely) while holding sblock(),
  such as a thread blocked in recv().

- Flag the sblock() call as non-interruptible so that a signal
  delivered to the thread calling sorflush() doesn't cause sblock() to
  fail.  The sblock() is required to ensure that all other socket
  consumer threads have, in fact, left, and do not enter, the socket
  buffer until we're done flushin it.

To implement the latter, change the 'flags' argument to sblock() to
accept two flags, SBL_WAIT and SBL_NOINTR, rather than one M_WAITOK
flag.  When SBL_NOINTR is set, it forces a non-interruptible sx
acquisition, regardless of the setting of the disposition of SB_NOINTR
on the socket buffer; without this change it would be possible for
another thread to clear SB_NOINTR between when the socket buffer mutex
is released and sblock() is invoked.

Reviewed by:	bz, kmacy
Reported by:	Jos Backus <jos at catnook dot com>
2008-01-31 08:22:24 +00:00

237 lines
8.1 KiB
C

/*-
* Copyright (c) 2001-2007, by Cisco Systems, Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* a) Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* b) 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.
*
* c) Neither the name of Cisco Systems, Inc. nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* 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.
*/
/* $KAME: sctp_peeloff.c,v 1.13 2005/03/06 16:04:18 itojun Exp $ */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <netinet/sctp_os.h>
#include <netinet/sctp_pcb.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_var.h>
#include <netinet/sctp_var.h>
#include <netinet/sctp_sysctl.h>
#include <netinet/sctp.h>
#include <netinet/sctp_uio.h>
#include <netinet/sctp_peeloff.h>
#include <netinet/sctputil.h>
#include <netinet/sctp_auth.h>
int
sctp_can_peel_off(struct socket *head, sctp_assoc_t assoc_id)
{
struct sctp_inpcb *inp;
struct sctp_tcb *stcb;
uint32_t state;
inp = (struct sctp_inpcb *)head->so_pcb;
if (inp == NULL) {
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_PEELOFF, EFAULT);
return (EFAULT);
}
stcb = sctp_findassociation_ep_asocid(inp, assoc_id, 1);
if (stcb == NULL) {
SCTP_LTRACE_ERR_RET(inp, stcb, NULL, SCTP_FROM_SCTP_PEELOFF, ENOENT);
return (ENOENT);
}
state = SCTP_GET_STATE((&stcb->asoc));
if ((state == SCTP_STATE_EMPTY) ||
(state == SCTP_STATE_INUSE) ||
(state == SCTP_STATE_COOKIE_WAIT) ||
(state == SCTP_STATE_COOKIE_ECHOED)) {
SCTP_TCB_UNLOCK(stcb);
SCTP_LTRACE_ERR_RET(inp, stcb, NULL, SCTP_FROM_SCTP_PEELOFF, ENOTCONN);
return (ENOTCONN);
}
SCTP_TCB_UNLOCK(stcb);
/* We are clear to peel this one off */
return (0);
}
int
sctp_do_peeloff(struct socket *head, struct socket *so, sctp_assoc_t assoc_id)
{
struct sctp_inpcb *inp, *n_inp;
struct sctp_tcb *stcb;
uint32_t state;
inp = (struct sctp_inpcb *)head->so_pcb;
if (inp == NULL) {
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_PEELOFF, EFAULT);
return (EFAULT);
}
stcb = sctp_findassociation_ep_asocid(inp, assoc_id, 1);
if (stcb == NULL) {
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_PEELOFF, ENOTCONN);
return (ENOTCONN);
}
state = SCTP_GET_STATE((&stcb->asoc));
if ((state == SCTP_STATE_EMPTY) ||
(state == SCTP_STATE_INUSE) ||
(state == SCTP_STATE_COOKIE_WAIT) ||
(state == SCTP_STATE_COOKIE_ECHOED)) {
SCTP_TCB_UNLOCK(stcb);
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_PEELOFF, ENOTCONN);
return (ENOTCONN);
}
n_inp = (struct sctp_inpcb *)so->so_pcb;
n_inp->sctp_flags = (SCTP_PCB_FLAGS_UDPTYPE |
SCTP_PCB_FLAGS_CONNECTED |
SCTP_PCB_FLAGS_IN_TCPPOOL | /* Turn on Blocking IO */
(SCTP_PCB_COPY_FLAGS & inp->sctp_flags));
n_inp->sctp_socket = so;
n_inp->sctp_features = inp->sctp_features;
n_inp->sctp_mobility_features = inp->sctp_mobility_features;
n_inp->sctp_frag_point = inp->sctp_frag_point;
n_inp->partial_delivery_point = inp->partial_delivery_point;
n_inp->sctp_context = inp->sctp_context;
n_inp->inp_starting_point_for_iterator = NULL;
/* copy in the authentication parameters from the original endpoint */
if (n_inp->sctp_ep.local_hmacs)
sctp_free_hmaclist(n_inp->sctp_ep.local_hmacs);
n_inp->sctp_ep.local_hmacs =
sctp_copy_hmaclist(inp->sctp_ep.local_hmacs);
if (n_inp->sctp_ep.local_auth_chunks)
sctp_free_chunklist(n_inp->sctp_ep.local_auth_chunks);
n_inp->sctp_ep.local_auth_chunks =
sctp_copy_chunklist(inp->sctp_ep.local_auth_chunks);
(void)sctp_copy_skeylist(&inp->sctp_ep.shared_keys,
&n_inp->sctp_ep.shared_keys);
/*
* Now we must move it from one hash table to another and get the
* stcb in the right place.
*/
sctp_move_pcb_and_assoc(inp, n_inp, stcb);
atomic_add_int(&stcb->asoc.refcnt, 1);
SCTP_TCB_UNLOCK(stcb);
sctp_pull_off_control_to_new_inp(inp, n_inp, stcb, SBL_WAIT);
atomic_subtract_int(&stcb->asoc.refcnt, 1);
return (0);
}
struct socket *
sctp_get_peeloff(struct socket *head, sctp_assoc_t assoc_id, int *error)
{
struct socket *newso;
struct sctp_inpcb *inp, *n_inp;
struct sctp_tcb *stcb;
SCTPDBG(SCTP_DEBUG_PEEL1, "SCTP peel-off called\n");
inp = (struct sctp_inpcb *)head->so_pcb;
if (inp == NULL) {
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_PEELOFF, EFAULT);
*error = EFAULT;
return (NULL);
}
stcb = sctp_findassociation_ep_asocid(inp, assoc_id, 1);
if (stcb == NULL) {
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP_PEELOFF, ENOTCONN);
*error = ENOTCONN;
return (NULL);
}
atomic_add_int(&stcb->asoc.refcnt, 1);
SCTP_TCB_UNLOCK(stcb);
newso = sonewconn(head, SS_ISCONNECTED
);
if (newso == NULL) {
SCTPDBG(SCTP_DEBUG_PEEL1, "sctp_peeloff:sonewconn failed\n");
SCTP_LTRACE_ERR_RET(NULL, stcb, NULL, SCTP_FROM_SCTP_PEELOFF, ENOMEM);
*error = ENOMEM;
atomic_subtract_int(&stcb->asoc.refcnt, 1);
return (NULL);
}
SCTP_TCB_LOCK(stcb);
atomic_subtract_int(&stcb->asoc.refcnt, 1);
n_inp = (struct sctp_inpcb *)newso->so_pcb;
SOCK_LOCK(head);
n_inp->sctp_flags = (SCTP_PCB_FLAGS_UDPTYPE |
SCTP_PCB_FLAGS_CONNECTED |
SCTP_PCB_FLAGS_IN_TCPPOOL | /* Turn on Blocking IO */
(SCTP_PCB_COPY_FLAGS & inp->sctp_flags));
n_inp->sctp_features = inp->sctp_features;
n_inp->sctp_frag_point = inp->sctp_frag_point;
n_inp->partial_delivery_point = inp->partial_delivery_point;
n_inp->sctp_context = inp->sctp_context;
n_inp->inp_starting_point_for_iterator = NULL;
/* copy in the authentication parameters from the original endpoint */
if (n_inp->sctp_ep.local_hmacs)
sctp_free_hmaclist(n_inp->sctp_ep.local_hmacs);
n_inp->sctp_ep.local_hmacs =
sctp_copy_hmaclist(inp->sctp_ep.local_hmacs);
if (n_inp->sctp_ep.local_auth_chunks)
sctp_free_chunklist(n_inp->sctp_ep.local_auth_chunks);
n_inp->sctp_ep.local_auth_chunks =
sctp_copy_chunklist(inp->sctp_ep.local_auth_chunks);
(void)sctp_copy_skeylist(&inp->sctp_ep.shared_keys,
&n_inp->sctp_ep.shared_keys);
n_inp->sctp_socket = newso;
if (sctp_is_feature_on(inp, SCTP_PCB_FLAGS_AUTOCLOSE)) {
sctp_feature_off(n_inp, SCTP_PCB_FLAGS_AUTOCLOSE);
n_inp->sctp_ep.auto_close_time = 0;
sctp_timer_stop(SCTP_TIMER_TYPE_AUTOCLOSE, n_inp, stcb, NULL,
SCTP_FROM_SCTP_PEELOFF + SCTP_LOC_1);
}
/* Turn off any non-blocking semantic. */
SCTP_CLEAR_SO_NBIO(newso);
newso->so_state |= SS_ISCONNECTED;
/* We remove it right away */
#ifdef SCTP_LOCK_LOGGING
if (sctp_logging_level & SCTP_LOCK_LOGGING_ENABLE) {
sctp_log_lock(inp, (struct sctp_tcb *)NULL, SCTP_LOG_LOCK_SOCK);
}
#endif
TAILQ_REMOVE(&head->so_comp, newso, so_list);
head->so_qlen--;
SOCK_UNLOCK(head);
/*
* Now we must move it from one hash table to another and get the
* stcb in the right place.
*/
sctp_move_pcb_and_assoc(inp, n_inp, stcb);
atomic_add_int(&stcb->asoc.refcnt, 1);
SCTP_TCB_UNLOCK(stcb);
/*
* And now the final hack. We move data in the pending side i.e.
* head to the new socket buffer. Let the GRUBBING begin :-0
*/
sctp_pull_off_control_to_new_inp(inp, n_inp, stcb, SBL_WAIT);
atomic_subtract_int(&stcb->asoc.refcnt, 1);
return (newso);
}