554 lines
13 KiB
C
554 lines
13 KiB
C
/*
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* Copyright (c) 1982, 1986, 1988, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* @(#)tcp_usrreq.c 8.2 (Berkeley) 1/3/94
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* $Id: tcp_usrreq.c,v 1.5 1994/09/15 10:36:56 davidg Exp $
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*/
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/malloc.h>
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#include <sys/mbuf.h>
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#include <sys/socket.h>
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#include <sys/socketvar.h>
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#include <sys/protosw.h>
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#include <sys/errno.h>
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#include <sys/stat.h>
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#include <net/if.h>
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#include <net/route.h>
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#include <netinet/in.h>
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#include <netinet/in_systm.h>
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#include <netinet/ip.h>
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#include <netinet/in_pcb.h>
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#include <netinet/ip_var.h>
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#include <netinet/tcp.h>
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#include <netinet/tcp_fsm.h>
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#include <netinet/tcp_seq.h>
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#include <netinet/tcp_timer.h>
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#include <netinet/tcp_var.h>
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#include <netinet/tcpip.h>
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#ifdef TCPDEBUG
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#include <netinet/tcp_debug.h>
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#endif
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/*
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* TCP protocol interface to socket abstraction.
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*/
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extern char *tcpstates[];
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/*
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* Process a TCP user request for TCP tb. If this is a send request
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* then m is the mbuf chain of send data. If this is a timer expiration
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* (called from the software clock routine), then timertype tells which timer.
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*/
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/*ARGSUSED*/
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int
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tcp_usrreq(so, req, m, nam, control)
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struct socket *so;
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int req;
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struct mbuf *m, *nam, *control;
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{
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register struct inpcb *inp;
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register struct tcpcb *tp = 0;
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struct sockaddr_in *sinp;
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int s;
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int error = 0;
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int ostate;
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if (req == PRU_CONTROL)
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return (in_control(so, (int)m, (caddr_t)nam,
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(struct ifnet *)control));
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if (control && control->m_len) {
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m_freem(control);
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if (m)
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m_freem(m);
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return (EINVAL);
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}
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s = splnet();
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inp = sotoinpcb(so);
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/*
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* When a TCP is attached to a socket, then there will be
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* a (struct inpcb) pointed at by the socket, and this
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* structure will point at a subsidary (struct tcpcb).
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*/
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if (inp == 0 && req != PRU_ATTACH) {
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splx(s);
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return (EINVAL); /* XXX */
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}
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if (inp) {
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tp = intotcpcb(inp);
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/* WHAT IF TP IS 0? */
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#ifdef KPROF
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tcp_acounts[tp->t_state][req]++;
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#endif
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ostate = tp->t_state;
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} else
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ostate = 0;
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switch (req) {
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/*
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* TCP attaches to socket via PRU_ATTACH, reserving space,
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* and an internet control block.
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*/
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case PRU_ATTACH:
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if (inp) {
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error = EISCONN;
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break;
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}
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error = tcp_attach(so);
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if (error)
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break;
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if ((so->so_options & SO_LINGER) && so->so_linger == 0)
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so->so_linger = TCP_LINGERTIME;
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tp = sototcpcb(so);
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break;
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/*
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* PRU_DETACH detaches the TCP protocol from the socket.
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* If the protocol state is non-embryonic, then can't
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* do this directly: have to initiate a PRU_DISCONNECT,
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* which may finish later; embryonic TCB's can just
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* be discarded here.
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*/
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case PRU_DETACH:
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if (tp->t_state > TCPS_LISTEN)
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tp = tcp_disconnect(tp);
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else
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tp = tcp_close(tp);
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break;
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/*
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* Give the socket an address.
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*/
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case PRU_BIND:
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/*
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* Must check for multicast addresses and disallow binding
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* to them.
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*/
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sinp = mtod(nam, struct sockaddr_in *);
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if (sinp->sin_family == AF_INET &&
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IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
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error = EAFNOSUPPORT;
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break;
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}
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error = in_pcbbind(inp, nam);
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if (error)
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break;
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break;
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/*
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* Prepare to accept connections.
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*/
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case PRU_LISTEN:
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if (inp->inp_lport == 0)
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error = in_pcbbind(inp, (struct mbuf *)0);
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if (error == 0)
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tp->t_state = TCPS_LISTEN;
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break;
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/*
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* Initiate connection to peer.
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* Create a template for use in transmissions on this connection.
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* Enter SYN_SENT state, and mark socket as connecting.
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* Start keep-alive timer, and seed output sequence space.
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* Send initial segment on connection.
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*/
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case PRU_CONNECT:
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/*
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* Must disallow TCP ``connections'' to multicast addresses.
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*/
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sinp = mtod(nam, struct sockaddr_in *);
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if (sinp->sin_family == AF_INET
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&& IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) {
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error = EAFNOSUPPORT;
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break;
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}
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if (inp->inp_lport == 0) {
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error = in_pcbbind(inp, (struct mbuf *)0);
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if (error)
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break;
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}
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error = in_pcbconnect(inp, nam);
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if (error)
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break;
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tp->t_template = tcp_template(tp);
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if (tp->t_template == 0) {
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in_pcbdisconnect(inp);
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error = ENOBUFS;
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break;
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}
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/* Compute window scaling to request. */
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while (tp->request_r_scale < TCP_MAX_WINSHIFT &&
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(TCP_MAXWIN << tp->request_r_scale) < so->so_rcv.sb_hiwat)
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tp->request_r_scale++;
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soisconnecting(so);
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tcpstat.tcps_connattempt++;
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tp->t_state = TCPS_SYN_SENT;
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tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT;
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tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2;
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tcp_sendseqinit(tp);
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error = tcp_output(tp);
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break;
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/*
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* Create a TCP connection between two sockets.
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*/
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case PRU_CONNECT2:
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error = EOPNOTSUPP;
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break;
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/*
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* Initiate disconnect from peer.
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* If connection never passed embryonic stage, just drop;
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* else if don't need to let data drain, then can just drop anyways,
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* else have to begin TCP shutdown process: mark socket disconnecting,
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* drain unread data, state switch to reflect user close, and
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* send segment (e.g. FIN) to peer. Socket will be really disconnected
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* when peer sends FIN and acks ours.
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*
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* SHOULD IMPLEMENT LATER PRU_CONNECT VIA REALLOC TCPCB.
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*/
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case PRU_DISCONNECT:
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tp = tcp_disconnect(tp);
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break;
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/*
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* Accept a connection. Essentially all the work is
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* done at higher levels; just return the address
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* of the peer, storing through addr.
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*/
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case PRU_ACCEPT:
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in_setpeeraddr(inp, nam);
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break;
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/*
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* Mark the connection as being incapable of further output.
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*/
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case PRU_SHUTDOWN:
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socantsendmore(so);
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tp = tcp_usrclosed(tp);
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if (tp)
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error = tcp_output(tp);
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break;
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/*
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* After a receive, possibly send window update to peer.
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*/
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case PRU_RCVD:
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(void) tcp_output(tp);
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break;
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/*
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* Do a send by putting data in output queue and updating urgent
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* marker if URG set. Possibly send more data.
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*/
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case PRU_SEND:
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sbappend(&so->so_snd, m);
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error = tcp_output(tp);
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break;
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/*
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* Abort the TCP.
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*/
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case PRU_ABORT:
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tp = tcp_drop(tp, ECONNABORTED);
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break;
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case PRU_SENSE:
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((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat;
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(void) splx(s);
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return (0);
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case PRU_RCVOOB:
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if ((so->so_oobmark == 0 &&
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(so->so_state & SS_RCVATMARK) == 0) ||
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so->so_options & SO_OOBINLINE ||
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tp->t_oobflags & TCPOOB_HADDATA) {
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error = EINVAL;
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break;
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}
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if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) {
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error = EWOULDBLOCK;
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break;
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}
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m->m_len = 1;
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*mtod(m, caddr_t) = tp->t_iobc;
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if (((int)nam & MSG_PEEK) == 0)
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tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
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break;
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case PRU_SENDOOB:
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if (sbspace(&so->so_snd) < -512) {
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m_freem(m);
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error = ENOBUFS;
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break;
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}
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/*
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* According to RFC961 (Assigned Protocols),
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* the urgent pointer points to the last octet
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* of urgent data. We continue, however,
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* to consider it to indicate the first octet
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* of data past the urgent section.
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* Otherwise, snd_up should be one lower.
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*/
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sbappend(&so->so_snd, m);
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tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
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tp->t_force = 1;
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error = tcp_output(tp);
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tp->t_force = 0;
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break;
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case PRU_SOCKADDR:
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in_setsockaddr(inp, nam);
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break;
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case PRU_PEERADDR:
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in_setpeeraddr(inp, nam);
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break;
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/*
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* TCP slow timer went off; going through this
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* routine for tracing's sake.
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*/
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case PRU_SLOWTIMO:
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tp = tcp_timers(tp, (int)nam);
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req |= (int)nam << 8; /* for debug's sake */
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break;
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default:
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panic("tcp_usrreq");
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}
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#ifdef TCPDEBUG
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if (tp && (so->so_options & SO_DEBUG))
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tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req);
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#endif
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splx(s);
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return (error);
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}
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int
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tcp_ctloutput(op, so, level, optname, mp)
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int op;
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struct socket *so;
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int level, optname;
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struct mbuf **mp;
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{
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int error = 0, s;
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struct inpcb *inp;
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register struct tcpcb *tp;
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register struct mbuf *m;
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register int i;
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s = splnet();
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inp = sotoinpcb(so);
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if (inp == NULL) {
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splx(s);
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if (op == PRCO_SETOPT && *mp)
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(void) m_free(*mp);
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return (ECONNRESET);
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}
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if (level != IPPROTO_TCP) {
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error = ip_ctloutput(op, so, level, optname, mp);
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splx(s);
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return (error);
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}
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tp = intotcpcb(inp);
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switch (op) {
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case PRCO_SETOPT:
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m = *mp;
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switch (optname) {
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case TCP_NODELAY:
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if (m == NULL || m->m_len < sizeof (int))
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error = EINVAL;
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else if (*mtod(m, int *))
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tp->t_flags |= TF_NODELAY;
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else
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tp->t_flags &= ~TF_NODELAY;
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break;
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case TCP_MAXSEG:
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if (m && (i = *mtod(m, int *)) > 0 && i <= tp->t_maxseg)
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tp->t_maxseg = i;
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else
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error = EINVAL;
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break;
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default:
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error = ENOPROTOOPT;
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break;
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}
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if (m)
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(void) m_free(m);
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break;
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case PRCO_GETOPT:
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*mp = m = m_get(M_WAIT, MT_SOOPTS);
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m->m_len = sizeof(int);
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switch (optname) {
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case TCP_NODELAY:
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*mtod(m, int *) = tp->t_flags & TF_NODELAY;
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break;
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case TCP_MAXSEG:
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*mtod(m, int *) = tp->t_maxseg;
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break;
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default:
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error = ENOPROTOOPT;
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break;
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}
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break;
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}
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splx(s);
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return (error);
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}
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/*
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* tcp_sendspace and tcp_recvspace are the default send and receive window
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* sizes, respectively. These are obsolescent (this information should
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* be set by the route).
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*/
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#ifdef TCP_SMALLSPACE
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u_long tcp_sendspace = 1024*4;
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u_long tcp_recvspace = 1024*4;
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#else
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u_long tcp_sendspace = 1024*16;
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u_long tcp_recvspace = 1024*16;
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#endif
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/*
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* Attach TCP protocol to socket, allocating
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* internet protocol control block, tcp control block,
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* bufer space, and entering LISTEN state if to accept connections.
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*/
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int
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tcp_attach(so)
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struct socket *so;
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{
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register struct tcpcb *tp;
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struct inpcb *inp;
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int error;
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if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) {
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error = soreserve(so, tcp_sendspace, tcp_recvspace);
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if (error)
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return (error);
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}
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error = in_pcballoc(so, &tcb);
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if (error)
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return (error);
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inp = sotoinpcb(so);
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tp = tcp_newtcpcb(inp);
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if (tp == 0) {
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int nofd = so->so_state & SS_NOFDREF; /* XXX */
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so->so_state &= ~SS_NOFDREF; /* don't free the socket yet */
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in_pcbdetach(inp);
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so->so_state |= nofd;
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return (ENOBUFS);
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}
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tp->t_state = TCPS_CLOSED;
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return (0);
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}
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/*
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* Initiate (or continue) disconnect.
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* If embryonic state, just send reset (once).
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* If in ``let data drain'' option and linger null, just drop.
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* Otherwise (hard), mark socket disconnecting and drop
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* current input data; switch states based on user close, and
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* send segment to peer (with FIN).
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*/
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struct tcpcb *
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tcp_disconnect(tp)
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register struct tcpcb *tp;
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{
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struct socket *so = tp->t_inpcb->inp_socket;
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if (tp->t_state < TCPS_ESTABLISHED)
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tp = tcp_close(tp);
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else if ((so->so_options & SO_LINGER) && so->so_linger == 0)
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tp = tcp_drop(tp, 0);
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else {
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soisdisconnecting(so);
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sbflush(&so->so_rcv);
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tp = tcp_usrclosed(tp);
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if (tp)
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(void) tcp_output(tp);
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}
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return (tp);
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}
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/*
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* User issued close, and wish to trail through shutdown states:
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* if never received SYN, just forget it. If got a SYN from peer,
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* but haven't sent FIN, then go to FIN_WAIT_1 state to send peer a FIN.
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* If already got a FIN from peer, then almost done; go to LAST_ACK
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* state. In all other cases, have already sent FIN to peer (e.g.
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* after PRU_SHUTDOWN), and just have to play tedious game waiting
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* for peer to send FIN or not respond to keep-alives, etc.
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* We can let the user exit from the close as soon as the FIN is acked.
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*/
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struct tcpcb *
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tcp_usrclosed(tp)
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register struct tcpcb *tp;
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{
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switch (tp->t_state) {
|
|
|
|
case TCPS_CLOSED:
|
|
case TCPS_LISTEN:
|
|
case TCPS_SYN_SENT:
|
|
tp->t_state = TCPS_CLOSED;
|
|
tp = tcp_close(tp);
|
|
break;
|
|
|
|
case TCPS_SYN_RECEIVED:
|
|
case TCPS_ESTABLISHED:
|
|
tp->t_state = TCPS_FIN_WAIT_1;
|
|
break;
|
|
|
|
case TCPS_CLOSE_WAIT:
|
|
tp->t_state = TCPS_LAST_ACK;
|
|
break;
|
|
}
|
|
if (tp && tp->t_state >= TCPS_FIN_WAIT_2)
|
|
soisdisconnected(tp->t_inpcb->inp_socket);
|
|
return (tp);
|
|
}
|