📄 tcp_usrreq.c
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//==========================================================================
//
// src/sys/netinet/tcp_usrreq.c
//
//==========================================================================
//####BSDCOPYRIGHTBEGIN####
//
// -------------------------------------------
//
// Portions of this software may have been derived from OpenBSD,
// FreeBSD or other sources, and are covered by the appropriate
// copyright disclaimers included herein.
//
// Portions created by Red Hat are
// Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
//
// -------------------------------------------
//
//####BSDCOPYRIGHTEND####
//==========================================================================
/*
* Copyright (c) 1982, 1986, 1988, 1993
* The Regents of the University of California. 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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
* $FreeBSD: src/sys/netinet/tcp_usrreq.c,v 1.51.2.9 2001/08/22 00:59:12 silby Exp $
*/
#include <sys/param.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 <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>
#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
#ifdef IPSEC
#include <netinet6/ipsec.h>
#endif /*IPSEC*/
/*
* TCP protocol interface to socket abstraction.
*/
extern char *tcpstates[]; /* XXX ??? */
static int tcp_attach __P((struct socket *, struct proc *));
static int tcp_connect __P((struct tcpcb *, struct sockaddr *,
struct proc *));
#ifdef INET6
static int tcp6_connect __P((struct tcpcb *, struct sockaddr *,
struct proc *));
#endif /* INET6 */
static struct tcpcb *
tcp_disconnect __P((struct tcpcb *));
static struct tcpcb *
tcp_usrclosed __P((struct tcpcb *));
#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 proc *p)
{
int s = splnet();
int error;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp = 0;
TCPDEBUG0;
TCPDEBUG1();
if (inp) {
error = EISCONN;
goto out;
}
error = tcp_attach(so, p);
if (error)
goto out;
if ((so->so_options & SO_LINGER) && so->so_linger == 0)
so->so_linger = TCP_LINGERTIME;
tp = sototcpcb(so);
out:
TCPDEBUG2(PRU_ATTACH);
splx(s);
return error;
}
/*
* 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 int
tcp_usr_detach(struct socket *so)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
TCPDEBUG0;
if (inp == 0) {
splx(s);
return EINVAL; /* XXX */
}
tp = intotcpcb(inp);
TCPDEBUG1();
tp = tcp_disconnect(tp);
TCPDEBUG2(PRU_DETACH);
splx(s);
return error;
}
#define COMMON_START() TCPDEBUG0; \ do { \ if (inp == 0) { \ splx(s); \ return EINVAL; \ } \ tp = intotcpcb(inp); \ TCPDEBUG1(); \ } while(0)
#define COMMON_END(req) out: TCPDEBUG2(req); splx(s); return error; goto out
/*
* Give the socket an address.
*/
static int
tcp_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
struct sockaddr_in *sinp;
COMMON_START();
/*
* Must check for multicast addresses and disallow binding
* to them.
*/
sinp = (struct sockaddr_in *)nam;
if (sinp->sin_family == AF_INET &&
IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
error = EAFNOSUPPORT;
goto out;
}
error = in_pcbbind(inp, nam, p);
if (error)
goto out;
COMMON_END(PRU_BIND);
}
#ifdef INET6
static int
tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
struct sockaddr_in6 *sin6p;
COMMON_START();
/*
* Must check for multicast addresses and disallow binding
* to them.
*/
sin6p = (struct sockaddr_in6 *)nam;
if (sin6p->sin6_family == AF_INET6 &&
IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
error = EAFNOSUPPORT;
goto out;
}
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
if (ip6_mapped_addr_on && (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, p);
goto out;
}
}
error = in6_pcbbind(inp, nam, p);
if (error)
goto out;
COMMON_END(PRU_BIND);
}
#endif /* INET6 */
/*
* Prepare to accept connections.
*/
static int
tcp_usr_listen(struct socket *so, struct proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
COMMON_START();
if (inp->inp_lport == 0)
error = in_pcbbind(inp, (struct sockaddr *)0, p);
if (error == 0)
tp->t_state = TCPS_LISTEN;
COMMON_END(PRU_LISTEN);
}
#ifdef INET6
static int
tcp6_usr_listen(struct socket *so, struct proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
COMMON_START();
if (inp->inp_lport == 0) {
inp->inp_vflag &= ~INP_IPV4;
if (ip6_mapped_addr_on &&
(inp->inp_flags & IN6P_IPV6_V6ONLY) == 0)
inp->inp_vflag |= INP_IPV4;
error = in6_pcbbind(inp, (struct sockaddr *)0, p);
}
if (error == 0)
tp->t_state = TCPS_LISTEN;
COMMON_END(PRU_LISTEN);
}
#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 proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
struct sockaddr_in *sinp;
COMMON_START();
/*
* Must disallow TCP ``connections'' to multicast addresses.
*/
sinp = (struct sockaddr_in *)nam;
if (sinp->sin_family == AF_INET
&& IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
error = EAFNOSUPPORT;
goto out;
}
if ((error = tcp_connect(tp, nam, p)) != 0)
goto out;
error = tcp_output(tp);
COMMON_END(PRU_CONNECT);
}
#ifdef INET6
static int
tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
struct sockaddr_in6 *sin6p;
COMMON_START();
/*
* Must disallow TCP ``connections'' to multicast addresses.
*/
sin6p = (struct sockaddr_in6 *)nam;
if (sin6p->sin6_family == AF_INET6
&& IN6_IS_ADDR_MULTICAST(&sin6p->sin6_addr)) {
error = EAFNOSUPPORT;
goto out;
}
if (IN6_IS_ADDR_V4MAPPED(&sin6p->sin6_addr)) {
struct sockaddr_in sin;
if (!ip6_mapped_addr_on ||
(inp->inp_flags & IN6P_IPV6_V6ONLY))
return(EINVAL);
in6_sin6_2_sin(&sin, sin6p);
inp->inp_vflag |= INP_IPV4;
inp->inp_vflag &= ~INP_IPV6;
if ((error = tcp_connect(tp, (struct sockaddr *)&sin, p)) != 0)
goto out;
error = tcp_output(tp);
goto out;
}
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
if ((error = tcp6_connect(tp, nam, p)) != 0)
goto out;
error = tcp_output(tp);
COMMON_END(PRU_CONNECT);
}
#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)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
COMMON_START();
tp = tcp_disconnect(tp);
COMMON_END(PRU_DISCONNECT);
}
/*
* 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 s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp = NULL;
TCPDEBUG0;
if (so->so_state & SS_ISDISCONNECTED) {
error = ECONNABORTED;
goto out;
}
if (inp == 0) {
splx(s);
return (EINVAL);
}
tp = intotcpcb(inp);
TCPDEBUG1();
in_setpeeraddr(so, nam);
COMMON_END(PRU_ACCEPT);
}
#ifdef INET6
static int
tcp6_usr_accept(struct socket *so, struct sockaddr **nam)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp = NULL;
TCPDEBUG0;
if (so->so_state & SS_ISDISCONNECTED) {
error = ECONNABORTED;
goto out;
}
if (inp == 0) {
splx(s);
return (EINVAL);
}
tp = intotcpcb(inp);
TCPDEBUG1();
in6_mapped_peeraddr(so, nam);
COMMON_END(PRU_ACCEPT);
}
#endif /* INET6 */
/*
* Mark the connection as being incapable of further output.
*/
static int
tcp_usr_shutdown(struct socket *so)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
COMMON_START();
socantsendmore(so);
tp = tcp_usrclosed(tp);
if (tp)
error = tcp_output(tp);
COMMON_END(PRU_SHUTDOWN);
}
/*
* After a receive, possibly send window update to peer.
*/
static int
tcp_usr_rcvd(struct socket *so, int flags)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
COMMON_START();
tcp_output(tp);
COMMON_END(PRU_RCVD);
}
/*
* 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 proc *p)
{
int s = splnet();
int error = 0;
struct inpcb *inp = sotoinpcb(so);
struct tcpcb *tp;
#ifdef INET6
int isipv6;
#endif
TCPDEBUG0;
if (inp == NULL) {
/*
* OOPS! we lost a race, the TCP session got reset after
* we checked SS_CANTSENDMORE, eg: while doing uiomove or a
* network interrupt in the non-splnet() section of sosend().
*/
if (m)
m_freem(m);
if (control)
m_freem(control);
error = ECONNRESET; /* XXX EPIPE? */
tp = NULL;
TCPDEBUG1();
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)) {
sbappend(&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
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