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15cc4a8205
freebsd/sys/netinet/tcp_usrreq.c
Robert Watson 109058b094 tcp_usrreq.c:1.313 removed tcbinfo locking from tcp_usr_accept(), which 
while in principle a good idea, opened us up to a race inherrent to
the syncache's direct insertion of incoming TCP connections into the
"completed connection" listen queue, as it transpires that the socket
is inserted before the inpcb is fully filled in by syncache_expand().
The bug manifested with the occasional returning of 0.0.0.0:0 in the
address returned by the accept() system call, which occurred if accept
managed to execute tcp_usr_accept() before syncache_expand() had copied
the endpoint addresses into inpcb connection state.

Re-add tcbinfo locking around the address copyout, which has the effect
of delaying the copy until syncache_expand() has finished running, as
it is run while the tcbinfo lock is held.  This is undesirable in that
it increases contention on tcbinfo further, but a more significant
change will be required to how the syncache inserts new sockets in
order to fix this and keep more granular locking here.  In particular,
either more state needs to be passed into sonewconn() so that
pru_attach() can fill in the fields *before* the socket is inserted, or
the socket needs to be inserted in the incomplete connection queue
until it is actually ready to be used.

Reported by:	glebius (and kris)
Tested by:	glebius
2008-01-23 21:15:51 +00:00

1897 lines
45 KiB
C
Raw Blame History

/*-
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California.
* Copyright (c) 2006-2007 Robert N. M. Watson
* 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.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
*
* From: @(#)tcp_usrreq.c 8.2 (Berkeley) 1/3/94
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_tcpdebug.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/sysctl.h>
#include <sys/mbuf.h>
#ifdef INET6
#include <sys/domain.h>
#endif /* INET6 */
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/proc.h>
#include <sys/jail.h>
#ifdef DDB
#include <ddb/ddb.h>
#endif
#include <net/if.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#ifdef INET6
#include <netinet/ip6.h>
#endif
#include <netinet/in_pcb.h>
#ifdef INET6
#include <netinet6/in6_pcb.h>
#endif
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#ifdef INET6
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#endif
#include <netinet/tcp.h>
#include <netinet/tcp_fsm.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
#include <netinet/tcpip.h>
#ifdef TCPDEBUG
#include <netinet/tcp_debug.h>
#endif
#include <netinet/tcp_offload.h>
/*
* TCP protocol interface to socket abstraction.
*/
static int tcp_attach(struct socket *);
static int tcp_connect(struct tcpcb *, struct sockaddr *,
struct thread *td);
#ifdef INET6
static int tcp6_connect(struct tcpcb *, struct sockaddr *,
struct thread *td);
#endif /* INET6 */
static void tcp_disconnect(struct tcpcb *);
static void tcp_usrclosed(struct tcpcb *);
static void tcp_fill_info(struct tcpcb *, struct tcp_info *);
#ifdef TCPDEBUG
#define TCPDEBUG0 int ostate = 0
#define TCPDEBUG1() ostate = tp ? tp->t_state : 0
#define TCPDEBUG2(req) if (tp && (so->so_options & SO_DEBUG)) \
tcp_trace(TA_USER, ostate, tp, 0, 0, req)
#else
#define TCPDEBUG0
#define TCPDEBUG1()
#define TCPDEBUG2(req)
#endif
/*
* TCP attaches to socket via pru_attach(), reserving space,
* and an internet control block.
*/
static int
tcp_usr_attach(struct socket *so, int proto, struct thread *td)
{
struct inpcb *inp;
struct tcpcb *tp = NULL;
int error;
TCPDEBUG0;
inp = sotoinpcb(so);
KASSERT(inp == NULL, ("tcp_usr_attach: inp != NULL"));
TCPDEBUG1();
error = tcp_attach(so);
if (error)
goto out;
if ((so->so_options & SO_LINGER) && so->so_linger == 0)
so->so_linger = TCP_LINGERTIME;
inp = sotoinpcb(so);
tp = intotcpcb(inp);
out:
TCPDEBUG2(PRU_ATTACH);
return error;
}
/*
* tcp_detach is called when the socket layer loses its final reference
* to the socket, be it a file descriptor reference, a reference from TCP,
* etc. At this point, there is only one case in which we will keep around
* inpcb state: time wait.
*
* This function can probably be re-absorbed back into tcp_usr_detach() now
* that there is a single detach path.
*/
static void
tcp_detach(struct socket *so, struct inpcb *inp)
{
struct tcpcb *tp;
#ifdef INET6
int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
#endif
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(inp);
KASSERT(so->so_pcb == inp, ("tcp_detach: so_pcb != inp"));
KASSERT(inp->inp_socket == so, ("tcp_detach: inp_socket != so"));
tp = intotcpcb(inp);
if (inp->inp_vflag & INP_TIMEWAIT) {
/*
* There are two cases to handle: one in which the time wait
* state is being discarded (INP_DROPPED), and one in which
* this connection will remain in timewait. In the former,
* it is time to discard all state (except tcptw, which has
* already been discarded by the timewait close code, which
* should be further up the call stack somewhere). In the
* latter case, we detach from the socket, but leave the pcb
* present until timewait ends.
*
* XXXRW: Would it be cleaner to free the tcptw here?
*/
if (inp->inp_vflag & INP_DROPPED) {
KASSERT(tp == NULL, ("tcp_detach: INP_TIMEWAIT && "
"INP_DROPPED && tp != NULL"));
#ifdef INET6
if (isipv6) {
in6_pcbdetach(inp);
in6_pcbfree(inp);
} else {
#endif
in_pcbdetach(inp);
in_pcbfree(inp);
#ifdef INET6
}
#endif
} else {
#ifdef INET6
if (isipv6)
in6_pcbdetach(inp);
else
#endif
in_pcbdetach(inp);
INP_UNLOCK(inp);
}
} else {
/*
* If the connection is not in timewait, we consider two
* two conditions: one in which no further processing is
* necessary (dropped || embryonic), and one in which TCP is
* not yet done, but no longer requires the socket, so the
* pcb will persist for the time being.
*
* XXXRW: Does the second case still occur?
*/
if (inp->inp_vflag & INP_DROPPED ||
tp->t_state < TCPS_SYN_SENT) {
tcp_discardcb(tp);
#ifdef INET6
if (isipv6) {
in6_pcbdetach(inp);
in6_pcbfree(inp);
} else {
#endif
in_pcbdetach(inp);
in_pcbfree(inp);
#ifdef INET6
}
#endif
} else {
#ifdef INET6
if (isipv6)
in6_pcbdetach(inp);
else
#endif
in_pcbdetach(inp);
}
}
}
/*
* pru_detach() detaches the TCP protocol from the socket.
* If the protocol state is non-embryonic, then can't
* do this directly: have to initiate a pru_disconnect(),
* which may finish later; embryonic TCB's can just
* be discarded here.
*/
static void
tcp_usr_detach(struct socket *so)
{
struct inpcb *inp;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_detach: inp == NULL"));
INP_INFO_WLOCK(&tcbinfo);
INP_LOCK(inp);
KASSERT(inp->inp_socket != NULL,
("tcp_usr_detach: inp_socket == NULL"));
tcp_detach(so, inp);
INP_INFO_WUNLOCK(&tcbinfo);
}
/*
* Give the socket an address.
*/
static int
tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
struct sockaddr_in *sinp;
sinp = (struct sockaddr_in *)nam;
if (nam->sa_len != sizeof (*sinp))
return (EINVAL);
/*
* Must check for multicast addresses and disallow binding
* to them.
*/
if (sinp->sin_family == AF_INET &&
IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
return (EAFNOSUPPORT);
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_bind: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
error = in_pcbbind(inp, nam, td->td_ucred);
out:
TCPDEBUG2(PRU_BIND);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
#ifdef INET6
static int
tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
struct sockaddr_in6 *sin6p;
sin6p = (struct sockaddr_in6 *)nam;
if (nam->sa_len != sizeof (*sin6p))
return (EINVAL);
/*
* Must check for multicast addresses and disallow binding
* to them.
*/
if (sin6p->sin6_family == AF_INET6 &&
IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
return (EAFNOSUPPORT);
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
if (IN6_IS_ADDR_UNSPECIFIED(&sin6p->sin6_addr))
inp->inp_vflag |= INP_IPV4;
else if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
struct sockaddr_in sin;
in6_sin6_2_sin(&sin, sin6p);
inp->inp_vflag |= INP_IPV4;
inp->inp_vflag &= ~INP_IPV6;
error = in_pcbbind(inp, (struct sockaddr *)&sin,
td->td_ucred);
goto out;
}
}
error = in6_pcbbind(inp, nam, td->td_ucred);
out:
TCPDEBUG2(PRU_BIND);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
#endif /* INET6 */
/*
* Prepare to accept connections.
*/
static int
tcp_usr_listen(struct socket *so, int backlog, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_listen: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
SOCK_LOCK(so);
error = solisten_proto_check(so);
if (error == 0 && inp->inp_lport == 0)
error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
if (error == 0) {
tp->t_state = TCPS_LISTEN;
solisten_proto(so, backlog);
tcp_offload_listen_open(tp);
}
SOCK_UNLOCK(so);
out:
TCPDEBUG2(PRU_LISTEN);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
#ifdef INET6
static int
tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp6_usr_listen: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
SOCK_LOCK(so);
error = solisten_proto_check(so);
if (error == 0 && inp->inp_lport == 0) {
inp->inp_vflag &= ~INP_IPV4;
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
inp->inp_vflag |= INP_IPV4;
error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
}
if (error == 0) {
tp->t_state = TCPS_LISTEN;
solisten_proto(so, backlog);
}
SOCK_UNLOCK(so);
out:
TCPDEBUG2(PRU_LISTEN);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
#endif /* INET6 */
/*
* Initiate connection to peer.
* Create a template for use in transmissions on this connection.
* Enter SYN_SENT state, and mark socket as connecting.
* Start keep-alive timer, and seed output sequence space.
* Send initial segment on connection.
*/
static int
tcp_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
struct sockaddr_in *sinp;
sinp = (struct sockaddr_in *)nam;
if (nam->sa_len != sizeof (*sinp))
return (EINVAL);
/*
* Must disallow TCP ``connections'' to multicast addresses.
*/
if (sinp->sin_family == AF_INET
&& IN_MULTICAST(ntohl(sinp->sin_addr.s_addr)))
return (EAFNOSUPPORT);
if (jailed(td->td_ucred))
prison_remote_ip(td->td_ucred, 0, &sinp->sin_addr.s_addr);
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_connect: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
if ((error = tcp_connect(tp, nam, td)) != 0)
goto out;
error = tcp_output_connect(so, nam);
out:
TCPDEBUG2(PRU_CONNECT);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
#ifdef INET6
static int
tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
struct sockaddr_in6 *sin6p;
TCPDEBUG0;
sin6p = (struct sockaddr_in6 *)nam;
if (nam->sa_len != sizeof (*sin6p))
return (EINVAL);
/*
* Must disallow TCP ``connections'' to multicast addresses.
*/
if (sin6p->sin6_family == AF_INET6
&& IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr))
return (EAFNOSUPPORT);
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
struct sockaddr_in sin;
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) != 0) {
error = EINVAL;
goto out;
}
in6_sin6_2_sin(&sin, sin6p);
inp->inp_vflag |= INP_IPV4;
inp->inp_vflag &= ~INP_IPV6;
if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
goto out;
error = tcp_output_connect(so, nam);
goto out;
}
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
inp->inp_inc.inc_isipv6 = 1;
if ((error = tcp6_connect(tp, nam, td)) != 0)
goto out;
error = tcp_output_connect(so, nam);
out:
TCPDEBUG2(PRU_CONNECT);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
#endif /* INET6 */
/*
* Initiate disconnect from peer.
* If connection never passed embryonic stage, just drop;
* else if don't need to let data drain, then can just drop anyways,
* else have to begin TCP shutdown process: mark socket disconnecting,
* drain unread data, state switch to reflect user close, and
* send segment (e.g. FIN) to peer. Socket will be really disconnected
* when peer sends FIN and acks ours.
*
* SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
*/
static int
tcp_usr_disconnect(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp = NULL;
int error = 0;
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_disconnect: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = ECONNRESET;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
tcp_disconnect(tp);
out:
TCPDEBUG2(PRU_DISCONNECT);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
/*
* Accept a connection. Essentially all the work is
* done at higher levels; just return the address
* of the peer, storing through addr.
*/
static int
tcp_usr_accept(struct socket *so, struct sockaddr **nam)
{
int error = 0;
struct inpcb *inp = NULL;
struct tcpcb *tp = NULL;
struct in_addr addr;
in_port_t port = 0;
TCPDEBUG0;
if (so->so_state & SS_ISDISCONNECTED)
return (ECONNABORTED);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_accept: inp == NULL"));
INP_INFO_RLOCK(&tcbinfo);
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = ECONNABORTED;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
/*
* We inline in_getpeeraddr and COMMON_END here, so that we can
* copy the data of interest and defer the malloc until after we
* release the lock.
*/
port = inp->inp_fport;
addr = inp->inp_faddr;
out:
TCPDEBUG2(PRU_ACCEPT);
INP_UNLOCK(inp);
INP_INFO_RUNLOCK(&tcbinfo);
if (error == 0)
*nam = in_sockaddr(port, &addr);
return error;
}
#ifdef INET6
static int
tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
{
struct inpcb *inp = NULL;
int error = 0;
struct tcpcb *tp = NULL;
struct in_addr addr;
struct in6_addr addr6;
in_port_t port = 0;
int v4 = 0;
TCPDEBUG0;
if (so->so_state & SS_ISDISCONNECTED)
return (ECONNABORTED);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp6_usr_accept: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = ECONNABORTED;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
/*
* We inline in6_mapped_peeraddr and COMMON_END here, so that we can
* copy the data of interest and defer the malloc until after we
* release the lock.
*/
if (inp->inp_vflag & INP_IPV4) {
v4 = 1;
port = inp->inp_fport;
addr = inp->inp_faddr;
} else {
port = inp->inp_fport;
addr6 = inp->in6p_faddr;
}
out:
TCPDEBUG2(PRU_ACCEPT);
INP_UNLOCK(inp);
if (error == 0) {
if (v4)
*nam = in6_v4mapsin6_sockaddr(port, &addr);
else
*nam = in6_sockaddr(port, &addr6);
}
return error;
}
#endif /* INET6 */
/*
* Mark the connection as being incapable of further output.
*/
static int
tcp_usr_shutdown(struct socket *so)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
TCPDEBUG0;
INP_INFO_WLOCK(&tcbinfo);
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = ECONNRESET;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
socantsendmore(so);
tcp_usrclosed(tp);
error = tcp_output_disconnect(tp);
out:
TCPDEBUG2(PRU_SHUTDOWN);
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
/*
* After a receive, possibly send window update to peer.
*/
static int
tcp_usr_rcvd(struct socket *so, int flags)
{
struct inpcb *inp;
struct tcpcb *tp = NULL;
int error = 0;
TCPDEBUG0;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_rcvd: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = ECONNRESET;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
tcp_output_rcvd(tp);
out:
TCPDEBUG2(PRU_RCVD);
INP_UNLOCK(inp);
return (error);
}
/*
* Do a send by putting data in output queue and updating urgent
* marker if URG set. Possibly send more data. Unlike the other
* pru_*() routines, the mbuf chains are our responsibility. We
* must either enqueue them or free them. The other pru_* routines
* generally are caller-frees.
*/
static int
tcp_usr_send(struct socket *so, int flags, struct mbuf *m,
struct sockaddr *nam, struct mbuf *control, struct thread *td)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
int headlocked = 0;
#ifdef INET6
int isipv6;
#endif
TCPDEBUG0;
/*
* We require the pcbinfo lock in two cases:
*
* (1) An implied connect is taking place, which can result in
* binding IPs and ports and hence modification of the pcb hash
* chains.
*
* (2) PRUS_EOF is set, resulting in explicit close on the send.
*/
if ((nam != NULL) || (flags & PRUS_EOF)) {
INP_INFO_WLOCK(&tcbinfo);
headlocked = 1;
}
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_send: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
if (control)
m_freem(control);
if (m)
m_freem(m);
error = ECONNRESET;
goto out;
}
#ifdef INET6
isipv6 = nam && nam->sa_family == AF_INET6;
#endif /* INET6 */
tp = intotcpcb(inp);
TCPDEBUG1();
if (control) {
/* TCP doesn't do control messages (rights, creds, etc) */
if (control->m_len) {
m_freem(control);
if (m)
m_freem(m);
error = EINVAL;
goto out;
}
m_freem(control); /* empty control, just free it */
}
if (!(flags & PRUS_OOB)) {
sbappendstream(&so->so_snd, m);
if (nam && tp->t_state < TCPS_SYN_SENT) {
/*
* Do implied connect if not yet connected,
* initialize window to default value, and
* initialize maxseg/maxopd using peer's cached
* MSS.
*/
INP_INFO_WLOCK_ASSERT(&tcbinfo);
#ifdef INET6
if (isipv6)
error = tcp6_connect(tp, nam, td);
else
#endif /* INET6 */
error = tcp_connect(tp, nam, td);
if (error)
goto out;
tp->snd_wnd = TTCP_CLIENT_SND_WND;
tcp_mss(tp, -1);
}
if (flags & PRUS_EOF) {
/*
* Close the send side of the connection after
* the data is sent.
*/
INP_INFO_WLOCK_ASSERT(&tcbinfo);
socantsendmore(so);
tcp_usrclosed(tp);
}
if (headlocked) {
INP_INFO_WUNLOCK(&tcbinfo);
headlocked = 0;
}
if (tp != NULL) {
if (flags & PRUS_MORETOCOME)
tp->t_flags |= TF_MORETOCOME;
error = tcp_output_send(tp);
if (flags & PRUS_MORETOCOME)
tp->t_flags &= ~TF_MORETOCOME;
}
} else {
/*
* XXXRW: PRUS_EOF not implemented with PRUS_OOB?
*/
SOCKBUF_LOCK(&so->so_snd);
if (sbspace(&so->so_snd) < -512) {
SOCKBUF_UNLOCK(&so->so_snd);
m_freem(m);
error = ENOBUFS;
goto out;
}
/*
* According to RFC961 (Assigned Protocols),
* the urgent pointer points to the last octet
* of urgent data. We continue, however,
* to consider it to indicate the first octet
* of data past the urgent section.
* Otherwise, snd_up should be one lower.
*/
sbappendstream_locked(&so->so_snd, m);
SOCKBUF_UNLOCK(&so->so_snd);
if (nam && tp->t_state < TCPS_SYN_SENT) {
/*
* Do implied connect if not yet connected,
* initialize window to default value, and
* initialize maxseg/maxopd using peer's cached
* MSS.
*/
INP_INFO_WLOCK_ASSERT(&tcbinfo);
#ifdef INET6
if (isipv6)
error = tcp6_connect(tp, nam, td);
else
#endif /* INET6 */
error = tcp_connect(tp, nam, td);
if (error)
goto out;
tp->snd_wnd = TTCP_CLIENT_SND_WND;
tcp_mss(tp, -1);
INP_INFO_WUNLOCK(&tcbinfo);
headlocked = 0;
} else if (nam) {
INP_INFO_WUNLOCK(&tcbinfo);
headlocked = 0;
}
tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
tp->t_flags |= TF_FORCEDATA;
error = tcp_output_send(tp);
tp->t_flags &= ~TF_FORCEDATA;
}
out:
TCPDEBUG2((flags & PRUS_OOB) ? PRU_SENDOOB :
((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND));
INP_UNLOCK(inp);
if (headlocked)
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
/*
* Abort the TCP. Drop the connection abruptly.
*/
static void
tcp_usr_abort(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp = NULL;
TCPDEBUG0;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_abort: inp == NULL"));
INP_INFO_WLOCK(&tcbinfo);
INP_LOCK(inp);
KASSERT(inp->inp_socket != NULL,
("tcp_usr_abort: inp_socket == NULL"));
/*
* If we still have full TCP state, and we're not dropped, drop.
*/
if (!(inp->inp_vflag & INP_TIMEWAIT) &&
!(inp->inp_vflag & INP_DROPPED)) {
tp = intotcpcb(inp);
TCPDEBUG1();
tcp_drop(tp, ECONNABORTED);
TCPDEBUG2(PRU_ABORT);
}
if (!(inp->inp_vflag & INP_DROPPED)) {
SOCK_LOCK(so);
so->so_state |= SS_PROTOREF;
SOCK_UNLOCK(so);
inp->inp_vflag |= INP_SOCKREF;
}
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
}
/*
* TCP socket is closed. Start friendly disconnect.
*/
static void
tcp_usr_close(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp = NULL;
TCPDEBUG0;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_close: inp == NULL"));
INP_INFO_WLOCK(&tcbinfo);
INP_LOCK(inp);
KASSERT(inp->inp_socket != NULL,
("tcp_usr_close: inp_socket == NULL"));
/*
* If we still have full TCP state, and we're not dropped, initiate
* a disconnect.
*/
if (!(inp->inp_vflag & INP_TIMEWAIT) &&
!(inp->inp_vflag & INP_DROPPED)) {
tp = intotcpcb(inp);
TCPDEBUG1();
tcp_disconnect(tp);
TCPDEBUG2(PRU_CLOSE);
}
if (!(inp->inp_vflag & INP_DROPPED)) {
SOCK_LOCK(so);
so->so_state |= SS_PROTOREF;
SOCK_UNLOCK(so);
inp->inp_vflag |= INP_SOCKREF;
}
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
}
/*
* Receive out-of-band data.
*/
static int
tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
TCPDEBUG0;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_usr_rcvoob: inp == NULL"));
INP_LOCK(inp);
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
error = ECONNRESET;
goto out;
}
tp = intotcpcb(inp);
TCPDEBUG1();
if ((so->so_oobmark == 0 &&
(so->so_rcv.sb_state & SBS_RCVATMARK) == 0) ||
so->so_options & SO_OOBINLINE ||
tp->t_oobflags & TCPOOB_HADDATA) {
error = EINVAL;
goto out;
}
if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
error = EWOULDBLOCK;
goto out;
}
m->m_len = 1;
*mtod(m, caddr_t) = tp->t_iobc;
if ((flags & MSG_PEEK) == 0)
tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
out:
TCPDEBUG2(PRU_RCVOOB);
INP_UNLOCK(inp);
return (error);
}
struct pr_usrreqs tcp_usrreqs = {
.pru_abort = tcp_usr_abort,
.pru_accept = tcp_usr_accept,
.pru_attach = tcp_usr_attach,
.pru_bind = tcp_usr_bind,
.pru_connect = tcp_usr_connect,
.pru_control = in_control,
.pru_detach = tcp_usr_detach,
.pru_disconnect = tcp_usr_disconnect,
.pru_listen = tcp_usr_listen,
.pru_peeraddr = in_getpeeraddr,
.pru_rcvd = tcp_usr_rcvd,
.pru_rcvoob = tcp_usr_rcvoob,
.pru_send = tcp_usr_send,
.pru_shutdown = tcp_usr_shutdown,
.pru_sockaddr = in_getsockaddr,
.pru_sosetlabel = in_pcbsosetlabel,
.pru_close = tcp_usr_close,
};
#ifdef INET6
struct pr_usrreqs tcp6_usrreqs = {
.pru_abort = tcp_usr_abort,
.pru_accept = tcp6_usr_accept,
.pru_attach = tcp_usr_attach,
.pru_bind = tcp6_usr_bind,
.pru_connect = tcp6_usr_connect,
.pru_control = in6_control,
.pru_detach = tcp_usr_detach,
.pru_disconnect = tcp_usr_disconnect,
.pru_listen = tcp6_usr_listen,
.pru_peeraddr = in6_mapped_peeraddr,
.pru_rcvd = tcp_usr_rcvd,
.pru_rcvoob = tcp_usr_rcvoob,
.pru_send = tcp_usr_send,
.pru_shutdown = tcp_usr_shutdown,
.pru_sockaddr = in6_mapped_sockaddr,
.pru_sosetlabel = in_pcbsosetlabel,
.pru_close = tcp_usr_close,
};
#endif /* INET6 */
/*
* Common subroutine to open a TCP connection to remote host specified
* by struct sockaddr_in in mbuf *nam. Call in_pcbbind to assign a local
* port number if needed. Call in_pcbconnect_setup to do the routing and
* to choose a local host address (interface). If there is an existing
* incarnation of the same connection in TIME-WAIT state and if the remote
* host was sending CC options and if the connection duration was < MSL, then
* truncate the previous TIME-WAIT state and proceed.
* Initialize connection parameters and enter SYN-SENT state.
*/
static int
tcp_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
{
struct inpcb *inp = tp->t_inpcb, *oinp;
struct socket *so = inp->inp_socket;
struct in_addr laddr;
u_short lport;
int error;
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(inp);
if (inp->inp_lport == 0) {
error = in_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
if (error)
return error;
}
/*
* Cannot simply call in_pcbconnect, because there might be an
* earlier incarnation of this same connection still in
* TIME_WAIT state, creating an ADDRINUSE error.
*/
laddr = inp->inp_laddr;
lport = inp->inp_lport;
error = in_pcbconnect_setup(inp, nam, &laddr.s_addr, &lport,
&inp->inp_faddr.s_addr, &inp->inp_fport, &oinp, td->td_ucred);
if (error && oinp == NULL)
return error;
if (oinp)
return EADDRINUSE;
inp->inp_laddr = laddr;
in_pcbrehash(inp);
/*
* Compute window scaling to request:
* Scale to fit into sweet spot. See tcp_syncache.c.
* XXX: This should move to tcp_output().
*/
while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
(TCP_MAXWIN << tp->request_r_scale) < sb_max)
tp->request_r_scale++;
soisconnecting(so);
tcpstat.tcps_connattempt++;
tp->t_state = TCPS_SYN_SENT;
tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
tp->iss = tcp_new_isn(tp);
tp->t_bw_rtseq = tp->iss;
tcp_sendseqinit(tp);
return 0;
}
#ifdef INET6
static int
tcp6_connect(struct tcpcb *tp, struct sockaddr *nam, struct thread *td)
{
struct inpcb *inp = tp->t_inpcb, *oinp;
struct socket *so = inp->inp_socket;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)nam;
struct in6_addr *addr6;
int error;
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(inp);
if (inp->inp_lport == 0) {
error = in6_pcbbind(inp, (struct sockaddr *)0, td->td_ucred);
if (error)
return error;
}
/*
* Cannot simply call in_pcbconnect, because there might be an
* earlier incarnation of this same connection still in
* TIME_WAIT state, creating an ADDRINUSE error.
* in6_pcbladdr() also handles scope zone IDs.
*/
error = in6_pcbladdr(inp, nam, &addr6);
if (error)
return error;
oinp = in6_pcblookup_hash(inp->inp_pcbinfo,
&sin6->sin6_addr, sin6->sin6_port,
IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr)
? addr6
: &inp->in6p_laddr,
inp->inp_lport, 0, NULL);
if (oinp)
return EADDRINUSE;
if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr))
inp->in6p_laddr = *addr6;
inp->in6p_faddr = sin6->sin6_addr;
inp->inp_fport = sin6->sin6_port;
/* update flowinfo - draft-itojun-ipv6-flowlabel-api-00 */
inp->in6p_flowinfo &= ~IPV6_FLOWLABEL_MASK;
if (inp->in6p_flags & IN6P_AUTOFLOWLABEL)
inp->in6p_flowinfo |=
(htonl(ip6_randomflowlabel()) & IPV6_FLOWLABEL_MASK);
in_pcbrehash(inp);
/* Compute window scaling to request. */
while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
(TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
tp->request_r_scale++;
soisconnecting(so);
tcpstat.tcps_connattempt++;
tp->t_state = TCPS_SYN_SENT;
tcp_timer_activate(tp, TT_KEEP, tcp_keepinit);
tp->iss = tcp_new_isn(tp);
tp->t_bw_rtseq = tp->iss;
tcp_sendseqinit(tp);
return 0;
}
#endif /* INET6 */
/*
* Export TCP internal state information via a struct tcp_info, based on the
* Linux 2.6 API. Not ABI compatible as our constants are mapped differently
* (TCP state machine, etc). We export all information using FreeBSD-native
* constants -- for example, the numeric values for tcpi_state will differ
* from Linux.
*/
static void
tcp_fill_info(struct tcpcb *tp, struct tcp_info *ti)
{
INP_LOCK_ASSERT(tp->t_inpcb);
bzero(ti, sizeof(*ti));
ti->tcpi_state = tp->t_state;
if ((tp->t_flags & TF_REQ_TSTMP) && (tp->t_flags & TF_RCVD_TSTMP))
ti->tcpi_options |= TCPI_OPT_TIMESTAMPS;
if (tp->t_flags & TF_SACK_PERMIT)
ti->tcpi_options |= TCPI_OPT_SACK;
if ((tp->t_flags & TF_REQ_SCALE) && (tp->t_flags & TF_RCVD_SCALE)) {
ti->tcpi_options |= TCPI_OPT_WSCALE;
ti->tcpi_snd_wscale = tp->snd_scale;
ti->tcpi_rcv_wscale = tp->rcv_scale;
}
ti->tcpi_rtt = ((u_int64_t)tp->t_srtt * tick) >> TCP_RTT_SHIFT;
ti->tcpi_rttvar = ((u_int64_t)tp->t_rttvar * tick) >> TCP_RTTVAR_SHIFT;
ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
ti->tcpi_snd_cwnd = tp->snd_cwnd;
/*
* FreeBSD-specific extension fields for tcp_info.
*/
ti->tcpi_rcv_space = tp->rcv_wnd;
ti->tcpi_snd_wnd = tp->snd_wnd;
ti->tcpi_snd_bwnd = tp->snd_bwnd;
}
/*
* tcp_ctloutput() must drop the inpcb lock before performing copyin on
* socket option arguments. When it re-acquires the lock after the copy, it
* has to revalidate that the connection is still valid for the socket
* option.
*/
#define INP_LOCK_RECHECK(inp) do { \
INP_LOCK(inp); \
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) { \
INP_UNLOCK(inp); \
return (ECONNRESET); \
} \
tp = intotcpcb(inp); \
} while(0)
int
tcp_ctloutput(struct socket *so, struct sockopt *sopt)
{
int error, opt, optval;
struct inpcb *inp;
struct tcpcb *tp;
struct tcp_info ti;
error = 0;
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp_ctloutput: inp == NULL"));
INP_LOCK(inp);
if (sopt->sopt_level != IPPROTO_TCP) {
#ifdef INET6
if (INP_CHECK_SOCKAF(so, AF_INET6)) {
INP_UNLOCK(inp);
error = ip6_ctloutput(so, sopt);
} else {
#endif /* INET6 */
INP_UNLOCK(inp);
error = ip_ctloutput(so, sopt);
#ifdef INET6
}
#endif
return (error);
}
if (inp->inp_vflag & (INP_TIMEWAIT | INP_DROPPED)) {
INP_UNLOCK(inp);
return (ECONNRESET);
}
switch (sopt->sopt_dir) {
case SOPT_SET:
switch (sopt->sopt_name) {
#ifdef TCP_SIGNATURE
case TCP_MD5SIG:
INP_UNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
return (error);
INP_LOCK_RECHECK(inp);
if (optval > 0)
tp->t_flags |= TF_SIGNATURE;
else
tp->t_flags &= ~TF_SIGNATURE;
INP_UNLOCK(inp);
break;
#endif /* TCP_SIGNATURE */
case TCP_NODELAY:
case TCP_NOOPT:
INP_UNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
return (error);
INP_LOCK_RECHECK(inp);
switch (sopt->sopt_name) {
case TCP_NODELAY:
opt = TF_NODELAY;
break;
case TCP_NOOPT:
opt = TF_NOOPT;
break;
default:
opt = 0; /* dead code to fool gcc */
break;
}
if (optval)
tp->t_flags |= opt;
else
tp->t_flags &= ~opt;
INP_UNLOCK(inp);
break;
case TCP_NOPUSH:
INP_UNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
return (error);
INP_LOCK_RECHECK(inp);
if (optval)
tp->t_flags |= TF_NOPUSH;
else {
tp->t_flags &= ~TF_NOPUSH;
error = tcp_output(tp);
}
INP_UNLOCK(inp);
break;
case TCP_MAXSEG:
INP_UNLOCK(inp);
error = sooptcopyin(sopt, &optval, sizeof optval,
sizeof optval);
if (error)
return (error);
INP_LOCK_RECHECK(inp);
if (optval > 0 && optval <= tp->t_maxseg &&
optval + 40 >= tcp_minmss)
tp->t_maxseg = optval;
else
error = EINVAL;
INP_UNLOCK(inp);
break;
case TCP_INFO:
INP_UNLOCK(inp);
error = EINVAL;
break;
default:
INP_UNLOCK(inp);
error = ENOPROTOOPT;
break;
}
break;
case SOPT_GET:
tp = intotcpcb(inp);
switch (sopt->sopt_name) {
#ifdef TCP_SIGNATURE
case TCP_MD5SIG:
optval = (tp->t_flags & TF_SIGNATURE) ? 1 : 0;
INP_UNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
#endif
case TCP_NODELAY:
optval = tp->t_flags & TF_NODELAY;
INP_UNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case TCP_MAXSEG:
optval = tp->t_maxseg;
INP_UNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case TCP_NOOPT:
optval = tp->t_flags & TF_NOOPT;
INP_UNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case TCP_NOPUSH:
optval = tp->t_flags & TF_NOPUSH;
INP_UNLOCK(inp);
error = sooptcopyout(sopt, &optval, sizeof optval);
break;
case TCP_INFO:
tcp_fill_info(tp, &ti);
INP_UNLOCK(inp);
error = sooptcopyout(sopt, &ti, sizeof ti);
break;
default:
INP_UNLOCK(inp);
error = ENOPROTOOPT;
break;
}
break;
}
return (error);
}
#undef INP_LOCK_RECHECK
/*
* tcp_sendspace and tcp_recvspace are the default send and receive window
* sizes, respectively. These are obsolescent (this information should
* be set by the route).
*/
u_long tcp_sendspace = 1024*32;
SYSCTL_ULONG(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW,
&tcp_sendspace , 0, "Maximum outgoing TCP datagram size");
u_long tcp_recvspace = 1024*64;
SYSCTL_ULONG(_net_inet_tcp, TCPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
&tcp_recvspace , 0, "Maximum incoming TCP datagram size");
/*
* Attach TCP protocol to socket, allocating
* internet protocol control block, tcp control block,
* bufer space, and entering LISTEN state if to accept connections.
*/
static int
tcp_attach(struct socket *so)
{
struct tcpcb *tp;
struct inpcb *inp;
int error;
#ifdef INET6
int isipv6 = INP_CHECK_SOCKAF(so, AF_INET6) != 0;
#endif
if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
error = soreserve(so, tcp_sendspace, tcp_recvspace);
if (error)
return (error);
}
so->so_rcv.sb_flags |= SB_AUTOSIZE;
so->so_snd.sb_flags |= SB_AUTOSIZE;
INP_INFO_WLOCK(&tcbinfo);
error = in_pcballoc(so, &tcbinfo);
if (error) {
INP_INFO_WUNLOCK(&tcbinfo);
return (error);
}
inp = sotoinpcb(so);
#ifdef INET6
if (isipv6) {
inp->inp_vflag |= INP_IPV6;
inp->in6p_hops = -1; /* use kernel default */
}
else
#endif
inp->inp_vflag |= INP_IPV4;
tp = tcp_newtcpcb(inp);
if (tp == NULL) {
#ifdef INET6
if (isipv6) {
in6_pcbdetach(inp);
in6_pcbfree(inp);
} else {
#endif
in_pcbdetach(inp);
in_pcbfree(inp);
#ifdef INET6
}
#endif
INP_INFO_WUNLOCK(&tcbinfo);
return (ENOBUFS);
}
tp->t_state = TCPS_CLOSED;
INP_UNLOCK(inp);
INP_INFO_WUNLOCK(&tcbinfo);
return (0);
}
/*
* Initiate (or continue) disconnect.
* If embryonic state, just send reset (once).
* If in ``let data drain'' option and linger null, just drop.
* Otherwise (hard), mark socket disconnecting and drop
* current input data; switch states based on user close, and
* send segment to peer (with FIN).
*/
static void
tcp_disconnect(struct tcpcb *tp)
{
struct inpcb *inp = tp->t_inpcb;
struct socket *so = inp->inp_socket;
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(inp);
/*
* Neither tcp_close() nor tcp_drop() should return NULL, as the
* socket is still open.
*/
if (tp->t_state < TCPS_ESTABLISHED) {
tp = tcp_close(tp);
KASSERT(tp != NULL,
("tcp_disconnect: tcp_close() returned NULL"));
} else if ((so->so_options & SO_LINGER) && so->so_linger == 0) {
tp = tcp_drop(tp, 0);
KASSERT(tp != NULL,
("tcp_disconnect: tcp_drop() returned NULL"));
} else {
soisdisconnecting(so);
sbflush(&so->so_rcv);
tcp_usrclosed(tp);
if (!(inp->inp_vflag & INP_DROPPED))
tcp_output_disconnect(tp);
}
}
/*
* User issued close, and wish to trail through shutdown states:
* if never received SYN, just forget it. If got a SYN from peer,
* but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
* If already got a FIN from peer, then almost done; go to LAST_ACK
* state. In all other cases, have already sent FIN to peer (e.g.
* after PRU_SHUTDOWN), and just have to play tedious game waiting
* for peer to send FIN or not respond to keep-alives, etc.
* We can let the user exit from the close as soon as the FIN is acked.
*/
static void
tcp_usrclosed(struct tcpcb *tp)
{
INP_INFO_WLOCK_ASSERT(&tcbinfo);
INP_LOCK_ASSERT(tp->t_inpcb);
switch (tp->t_state) {
case TCPS_LISTEN:
tcp_offload_listen_close(tp);
/* FALLTHROUGH */
case TCPS_CLOSED:
tp->t_state = TCPS_CLOSED;
tp = tcp_close(tp);
/*
* tcp_close() should never return NULL here as the socket is
* still open.
*/
KASSERT(tp != NULL,
("tcp_usrclosed: tcp_close() returned NULL"));
break;
case TCPS_SYN_SENT:
case TCPS_SYN_RECEIVED:
tp->t_flags |= TF_NEEDFIN;
break;
case TCPS_ESTABLISHED:
tp->t_state = TCPS_FIN_WAIT_1;
break;
case TCPS_CLOSE_WAIT:
tp->t_state = TCPS_LAST_ACK;
break;
}
if (tp->t_state >= TCPS_FIN_WAIT_2) {
soisdisconnected(tp->t_inpcb->inp_socket);
/* Prevent the connection hanging in FIN_WAIT_2 forever. */
if (tp->t_state == TCPS_FIN_WAIT_2) {
int timeout;
timeout = (tcp_fast_finwait2_recycle) ?
tcp_finwait2_timeout : tcp_maxidle;
tcp_timer_activate(tp, TT_2MSL, timeout);
}
}
}
#ifdef DDB
static void
db_print_indent(int indent)
{
int i;
for (i = 0; i < indent; i++)
db_printf(" ");
}
static void
db_print_tstate(int t_state)
{
switch (t_state) {
case TCPS_CLOSED:
db_printf("TCPS_CLOSED");
return;
case TCPS_LISTEN:
db_printf("TCPS_LISTEN");
return;
case TCPS_SYN_SENT:
db_printf("TCPS_SYN_SENT");
return;
case TCPS_SYN_RECEIVED:
db_printf("TCPS_SYN_RECEIVED");
return;
case TCPS_ESTABLISHED:
db_printf("TCPS_ESTABLISHED");
return;
case TCPS_CLOSE_WAIT:
db_printf("TCPS_CLOSE_WAIT");
return;
case TCPS_FIN_WAIT_1:
db_printf("TCPS_FIN_WAIT_1");
return;
case TCPS_CLOSING:
db_printf("TCPS_CLOSING");
return;
case TCPS_LAST_ACK:
db_printf("TCPS_LAST_ACK");
return;
case TCPS_FIN_WAIT_2:
db_printf("TCPS_FIN_WAIT_2");
return;
case TCPS_TIME_WAIT:
db_printf("TCPS_TIME_WAIT");
return;
default:
db_printf("unknown");
return;
}
}
static void
db_print_tflags(u_int t_flags)
{
int comma;
comma = 0;
if (t_flags & TF_ACKNOW) {
db_printf("%sTF_ACKNOW", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_DELACK) {
db_printf("%sTF_DELACK", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_NODELAY) {
db_printf("%sTF_NODELAY", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_NOOPT) {
db_printf("%sTF_NOOPT", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_SENTFIN) {
db_printf("%sTF_SENTFIN", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_REQ_SCALE) {
db_printf("%sTF_REQ_SCALE", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_RCVD_SCALE) {
db_printf("%sTF_RECVD_SCALE", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_REQ_TSTMP) {
db_printf("%sTF_REQ_TSTMP", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_RCVD_TSTMP) {
db_printf("%sTF_RCVD_TSTMP", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_SACK_PERMIT) {
db_printf("%sTF_SACK_PERMIT", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_NEEDSYN) {
db_printf("%sTF_NEEDSYN", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_NEEDFIN) {
db_printf("%sTF_NEEDFIN", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_NOPUSH) {
db_printf("%sTF_NOPUSH", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_NOPUSH) {
db_printf("%sTF_NOPUSH", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_MORETOCOME) {
db_printf("%sTF_MORETOCOME", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_LQ_OVERFLOW) {
db_printf("%sTF_LQ_OVERFLOW", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_LASTIDLE) {
db_printf("%sTF_LASTIDLE", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_RXWIN0SENT) {
db_printf("%sTF_RXWIN0SENT", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_FASTRECOVERY) {
db_printf("%sTF_FASTRECOVERY", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_WASFRECOVERY) {
db_printf("%sTF_WASFRECOVERY", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_SIGNATURE) {
db_printf("%sTF_SIGNATURE", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_FORCEDATA) {
db_printf("%sTF_FORCEDATA", comma ? ", " : "");
comma = 1;
}
if (t_flags & TF_TSO) {
db_printf("%sTF_TSO", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_toobflags(char t_oobflags)
{
int comma;
comma = 0;
if (t_oobflags & TCPOOB_HAVEDATA) {
db_printf("%sTCPOOB_HAVEDATA", comma ? ", " : "");
comma = 1;
}
if (t_oobflags & TCPOOB_HADDATA) {
db_printf("%sTCPOOB_HADDATA", comma ? ", " : "");
comma = 1;
}
}
static void
db_print_tcpcb(struct tcpcb *tp, const char *name, int indent)
{
db_print_indent(indent);
db_printf("%s at %p\n", name, tp);
indent += 2;
db_print_indent(indent);
db_printf("t_segq first: %p t_segqlen: %d t_dupacks: %d\n",
LIST_FIRST(&tp->t_segq), tp->t_segqlen, tp->t_dupacks);
db_print_indent(indent);
db_printf("tt_rexmt: %p tt_persist: %p tt_keep: %p\n",
&tp->t_timers->tt_rexmt, &tp->t_timers->tt_persist, &tp->t_timers->tt_keep);
db_print_indent(indent);
db_printf("tt_2msl: %p tt_delack: %p t_inpcb: %p\n", &tp->t_timers->tt_2msl,
&tp->t_timers->tt_delack, tp->t_inpcb);
db_print_indent(indent);
db_printf("t_state: %d (", tp->t_state);
db_print_tstate(tp->t_state);
db_printf(")\n");
db_print_indent(indent);
db_printf("t_flags: 0x%x (", tp->t_flags);
db_print_tflags(tp->t_flags);
db_printf(")\n");
db_print_indent(indent);
db_printf("snd_una: 0x%08x snd_max: 0x%08x snd_nxt: x0%08x\n",
tp->snd_una, tp->snd_max, tp->snd_nxt);
db_print_indent(indent);
db_printf("snd_up: 0x%08x snd_wl1: 0x%08x snd_wl2: 0x%08x\n",
tp->snd_up, tp->snd_wl1, tp->snd_wl2);
db_print_indent(indent);
db_printf("iss: 0x%08x irs: 0x%08x rcv_nxt: 0x%08x\n",
tp->iss, tp->irs, tp->rcv_nxt);
db_print_indent(indent);
db_printf("rcv_adv: 0x%08x rcv_wnd: %lu rcv_up: 0x%08x\n",
tp->rcv_adv, tp->rcv_wnd, tp->rcv_up);
db_print_indent(indent);
db_printf("snd_wnd: %lu snd_cwnd: %lu snd_bwnd: %lu\n",
tp->snd_wnd, tp->snd_cwnd, tp->snd_bwnd);
db_print_indent(indent);
db_printf("snd_ssthresh: %lu snd_bandwidth: %lu snd_recover: "
"0x%08x\n", tp->snd_ssthresh, tp->snd_bandwidth,
tp->snd_recover);
db_print_indent(indent);
db_printf("t_maxopd: %u t_rcvtime: %lu t_startime: %lu\n",
tp->t_maxopd, tp->t_rcvtime, tp->t_starttime);
db_print_indent(indent);
db_printf("t_rttime: %d t_rtsq: 0x%08x t_bw_rtttime: %d\n",
tp->t_rtttime, tp->t_rtseq, tp->t_bw_rtttime);
db_print_indent(indent);
db_printf("t_bw_rtseq: 0x%08x t_rxtcur: %d t_maxseg: %u "
"t_srtt: %d\n", tp->t_bw_rtseq, tp->t_rxtcur, tp->t_maxseg,
tp->t_srtt);
db_print_indent(indent);
db_printf("t_rttvar: %d t_rxtshift: %d t_rttmin: %u "
"t_rttbest: %u\n", tp->t_rttvar, tp->t_rxtshift, tp->t_rttmin,
tp->t_rttbest);
db_print_indent(indent);
db_printf("t_rttupdated: %lu max_sndwnd: %lu t_softerror: %d\n",
tp->t_rttupdated, tp->max_sndwnd, tp->t_softerror);
db_print_indent(indent);
db_printf("t_oobflags: 0x%x (", tp->t_oobflags);
db_print_toobflags(tp->t_oobflags);
db_printf(") t_iobc: 0x%02x\n", tp->t_iobc);
db_print_indent(indent);
db_printf("snd_scale: %u rcv_scale: %u request_r_scale: %u\n",
tp->snd_scale, tp->rcv_scale, tp->request_r_scale);
db_print_indent(indent);
db_printf("ts_recent: %u ts_recent_age: %lu\n",
tp->ts_recent, tp->ts_recent_age);
db_print_indent(indent);
db_printf("ts_offset: %u last_ack_sent: 0x%08x snd_cwnd_prev: "
"%lu\n", tp->ts_offset, tp->last_ack_sent, tp->snd_cwnd_prev);
db_print_indent(indent);
db_printf("snd_ssthresh_prev: %lu snd_recover_prev: 0x%08x "
"t_badrxtwin: %lu\n", tp->snd_ssthresh_prev,
tp->snd_recover_prev, tp->t_badrxtwin);
db_print_indent(indent);
db_printf("snd_numholes: %d snd_holes first: %p\n",
tp->snd_numholes, TAILQ_FIRST(&tp->snd_holes));
db_print_indent(indent);
db_printf("snd_fack: 0x%08x rcv_numsacks: %d sack_newdata: "
"0x%08x\n", tp->snd_fack, tp->rcv_numsacks, tp->sack_newdata);
/* Skip sackblks, sackhint. */
db_print_indent(indent);
db_printf("t_rttlow: %d rfbuf_ts: %u rfbuf_cnt: %d\n",
tp->t_rttlow, tp->rfbuf_ts, tp->rfbuf_cnt);
}
DB_SHOW_COMMAND(tcpcb, db_show_tcpcb)
{
struct tcpcb *tp;
if (!have_addr) {
db_printf("usage: show tcpcb <addr>\n");
return;
}
tp = (struct tcpcb *)addr;
db_print_tcpcb(tp, "tcpcb", 0);
}
#endif
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