/* * 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. * * @(#)tcp_usrreq.c 8.2 (Berkeley) 1/3/94 * $Id: tcp_usrreq.c,v 1.6 1994/12/15 20:39:34 wollman Exp $ */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef TCPDEBUG #include #endif /* * TCP protocol interface to socket abstraction. */ extern char *tcpstates[]; /* * Process a TCP user request for TCP tb. If this is a send request * then m is the mbuf chain of send data. If this is a timer expiration * (called from the software clock routine), then timertype tells which timer. */ /*ARGSUSED*/ int tcp_usrreq(so, req, m, nam, control) struct socket *so; int req; struct mbuf *m, *nam, *control; { register struct inpcb *inp; register struct tcpcb *tp = 0; struct sockaddr_in *sinp; int s; int error = 0; #ifdef TCPDEBUG int ostate; #endif if (req == PRU_CONTROL) return (in_control(so, (int)m, (caddr_t)nam, (struct ifnet *)control)); if (control && control->m_len) { m_freem(control); if (m) m_freem(m); return (EINVAL); } s = splnet(); inp = sotoinpcb(so); /* * When a TCP is attached to a socket, then there will be * a (struct inpcb) pointed at by the socket, and this * structure will point at a subsidary (struct tcpcb). */ if (inp == 0 && req != PRU_ATTACH) { splx(s); return (EINVAL); /* XXX */ } if (inp) { tp = intotcpcb(inp); /* WHAT IF TP IS 0? */ #ifdef KPROF tcp_acounts[tp->t_state][req]++; #endif #ifdef TCPDEBUG ostate = tp->t_state; } else ostate = 0; #else /* TCPDEBUG */ } #endif /* TCPDEBUG */ switch (req) { /* * TCP attaches to socket via PRU_ATTACH, reserving space, * and an internet control block. */ case PRU_ATTACH: if (inp) { error = EISCONN; break; } error = tcp_attach(so); if (error) break; if ((so->so_options & SO_LINGER) && so->so_linger == 0) so->so_linger = TCP_LINGERTIME; tp = sototcpcb(so); break; /* * 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. */ case PRU_DETACH: if (tp->t_state > TCPS_LISTEN) tp = tcp_disconnect(tp); else tp = tcp_close(tp); break; /* * Give the socket an address. */ case PRU_BIND: /* * Must check for multicast addresses and disallow binding * to them. */ sinp = mtod(nam, struct sockaddr_in *); if (sinp->sin_family == AF_INET && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) { error = EAFNOSUPPORT; break; } error = in_pcbbind(inp, nam); if (error) break; break; /* * Prepare to accept connections. */ case PRU_LISTEN: if (inp->inp_lport == 0) error = in_pcbbind(inp, (struct mbuf *)0); if (error == 0) tp->t_state = TCPS_LISTEN; break; /* * 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. */ case PRU_CONNECT: /* * Must disallow TCP ``connections'' to multicast addresses. */ sinp = mtod(nam, struct sockaddr_in *); if (sinp->sin_family == AF_INET && IN_MULTICAST(ntohl(sinp->sin_addr.s_addr))) { error = EAFNOSUPPORT; break; } #ifdef TTCP if ((error = tcp_connect(tp, nam)) != 0) break; #else /* TTCP */ if (inp->inp_lport == 0) { error = in_pcbbind(inp, (struct mbuf *)0); if (error) break; } error = in_pcbconnect(inp, nam); if (error) break; tp->t_template = tcp_template(tp); if (tp->t_template == 0) { in_pcbdisconnect(inp); error = ENOBUFS; break; } /* 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; tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; tcp_sendseqinit(tp); #endif /* TTCP */ error = tcp_output(tp); break; /* * Create a TCP connection between two sockets. */ case PRU_CONNECT2: error = EOPNOTSUPP; break; /* * 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. */ case PRU_DISCONNECT: tp = tcp_disconnect(tp); break; /* * Accept a connection. Essentially all the work is * done at higher levels; just return the address * of the peer, storing through addr. */ case PRU_ACCEPT: in_setpeeraddr(inp, nam); break; /* * Mark the connection as being incapable of further output. */ case PRU_SHUTDOWN: socantsendmore(so); tp = tcp_usrclosed(tp); if (tp) error = tcp_output(tp); break; /* * After a receive, possibly send window update to peer. */ case PRU_RCVD: (void) tcp_output(tp); break; /* * Do a send by putting data in output queue and updating urgent * marker if URG set. Possibly send more data. */ #ifdef TTCP case PRU_SEND_EOF: #endif case PRU_SEND: sbappend(&so->so_snd, m); #ifdef TTCP 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. */ error = tcp_connect(tp, nam); if (error) break; tp->snd_wnd = TTCP_CLIENT_SND_WND; tcp_mss(tp, -1); } if (req == PRU_SEND_EOF) { /* * Close the send side of the connection after * the data is sent. */ socantsendmore(so); tp = tcp_usrclosed(tp); } if (tp != NULL) #endif TTCP error = tcp_output(tp); break; /* * Abort the TCP. */ case PRU_ABORT: tp = tcp_drop(tp, ECONNABORTED); break; case PRU_SENSE: ((struct stat *) m)->st_blksize = so->so_snd.sb_hiwat; (void) splx(s); return (0); case PRU_RCVOOB: if ((so->so_oobmark == 0 && (so->so_state & SS_RCVATMARK) == 0) || so->so_options & SO_OOBINLINE || tp->t_oobflags & TCPOOB_HADDATA) { error = EINVAL; break; } if ((tp->t_oobflags & TCPOOB_HAVEDATA) == 0) { error = EWOULDBLOCK; break; } m->m_len = 1; *mtod(m, caddr_t) = tp->t_iobc; if (((int)nam & MSG_PEEK) == 0) tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA); break; case PRU_SENDOOB: if (sbspace(&so->so_snd) < -512) { m_freem(m); error = ENOBUFS; break; } /* * 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. */ sbappend(&so->so_snd, m); tp->snd_up = tp->snd_una + so->so_snd.sb_cc; tp->t_force = 1; error = tcp_output(tp); tp->t_force = 0; break; case PRU_SOCKADDR: in_setsockaddr(inp, nam); break; case PRU_PEERADDR: in_setpeeraddr(inp, nam); break; /* * TCP slow timer went off; going through this * routine for tracing's sake. */ case PRU_SLOWTIMO: tp = tcp_timers(tp, (int)nam); #ifdef TCPDEBUG req |= (int)nam << 8; /* for debug's sake */ #endif break; default: panic("tcp_usrreq"); } #ifdef TCPDEBUG if (tp && (so->so_options & SO_DEBUG)) tcp_trace(TA_USER, ostate, tp, (struct tcpiphdr *)0, req); #endif splx(s); return (error); } #ifdef TTCP /* * 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_pcbladdr 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. */ int tcp_connect(tp, nam) register struct tcpcb *tp; struct mbuf *nam; { struct inpcb *inp = tp->t_inpcb, *oinp; struct socket *so = inp->inp_socket; struct tcpcb *otp; struct sockaddr_in *sin = mtod(nam, struct sockaddr_in *); struct sockaddr_in *ifaddr; int error; if (inp->inp_lport == 0) { error = in_pcbbind(inp, NULL); 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. */ error = in_pcbladdr(inp, nam, &ifaddr); oinp = in_pcblookup(inp->inp_head, sin->sin_addr, sin->sin_port, inp->inp_laddr.s_addr != INADDR_ANY ? inp->inp_laddr : ifaddr->sin_addr, inp->inp_lport, 0); if (oinp) { if (oinp != inp && (otp = intotcpcb(oinp)) != NULL && otp->t_state == TCPS_TIME_WAIT && otp->t_duration < TCPTV_MSL && (otp->t_flags & TF_RCVD_CC)) otp = tcp_close(otp); else return EADDRINUSE; } if (inp->inp_laddr.s_addr == INADDR_ANY) inp->inp_laddr = ifaddr->sin_addr; inp->inp_faddr = sin->sin_addr; inp->inp_fport = sin->sin_port; tp->t_template = tcp_template(tp); if (tp->t_template == 0) { in_pcbdisconnect(inp); return ENOBUFS; } /* 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; tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; tcp_sendseqinit(tp); tp->cc_send = CC_INC(tcp_ccgen); return 0; } #endif /* TTCP */ int tcp_ctloutput(op, so, level, optname, mp) int op; struct socket *so; int level, optname; struct mbuf **mp; { int error = 0, s; struct inpcb *inp; register struct tcpcb *tp; register struct mbuf *m; register int i; s = splnet(); inp = sotoinpcb(so); if (inp == NULL) { splx(s); if (op == PRCO_SETOPT && *mp) (void) m_free(*mp); return (ECONNRESET); } if (level != IPPROTO_TCP) { error = ip_ctloutput(op, so, level, optname, mp); splx(s); return (error); } tp = intotcpcb(inp); switch (op) { case PRCO_SETOPT: m = *mp; switch (optname) { case TCP_NODELAY: if (m == NULL || m->m_len < sizeof (int)) error = EINVAL; else if (*mtod(m, int *)) tp->t_flags |= TF_NODELAY; else tp->t_flags &= ~TF_NODELAY; break; case TCP_MAXSEG: if (m && (i = *mtod(m, int *)) > 0 && i <= tp->t_maxseg) tp->t_maxseg = i; else error = EINVAL; break; #ifdef TTCP case TCP_NOOPT: if (m == NULL || m->m_len < sizeof (int)) error = EINVAL; else if (*mtod(m, int *)) tp->t_flags |= TF_NOOPT; else tp->t_flags &= ~TF_NOOPT; break; case TCP_NOPUSH: if (m == NULL || m->m_len < sizeof (int)) error = EINVAL; else if (*mtod(m, int *)) tp->t_flags |= TF_NOPUSH; else tp->t_flags &= ~TF_NOPUSH; break; #endif /* TTCP */ default: error = ENOPROTOOPT; break; } if (m) (void) m_free(m); break; case PRCO_GETOPT: *mp = m = m_get(M_WAIT, MT_SOOPTS); m->m_len = sizeof(int); switch (optname) { case TCP_NODELAY: *mtod(m, int *) = tp->t_flags & TF_NODELAY; break; case TCP_MAXSEG: *mtod(m, int *) = tp->t_maxseg; break; #ifdef TTCP case TCP_NOOPT: *mtod(m, int *) = tp->t_flags & TF_NOOPT; break; case TCP_NOPUSH: *mtod(m, int *) = tp->t_flags & TF_NOPUSH; break; #endif /* TTCP */ default: error = ENOPROTOOPT; break; } break; } splx(s); return (error); } /* * 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). */ #ifdef TCP_SMALLSPACE u_long tcp_sendspace = 1024*4; u_long tcp_recvspace = 1024*4; #else u_long tcp_sendspace = 1024*16; u_long tcp_recvspace = 1024*16; #endif /* * Attach TCP protocol to socket, allocating * internet protocol control block, tcp control block, * bufer space, and entering LISTEN state if to accept connections. */ int tcp_attach(so) struct socket *so; { register struct tcpcb *tp; struct inpcb *inp; int error; if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0) { error = soreserve(so, tcp_sendspace, tcp_recvspace); if (error) return (error); } error = in_pcballoc(so, &tcb); if (error) return (error); inp = sotoinpcb(so); tp = tcp_newtcpcb(inp); if (tp == 0) { int nofd = so->so_state & SS_NOFDREF; /* XXX */ so->so_state &= ~SS_NOFDREF; /* don't free the socket yet */ in_pcbdetach(inp); so->so_state |= nofd; return (ENOBUFS); } tp->t_state = TCPS_CLOSED; 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). */ struct tcpcb * tcp_disconnect(tp) register struct tcpcb *tp; { struct socket *so = tp->t_inpcb->inp_socket; if (tp->t_state < TCPS_ESTABLISHED) tp = tcp_close(tp); else if ((so->so_options & SO_LINGER) && so->so_linger == 0) tp = tcp_drop(tp, 0); else { soisdisconnecting(so); sbflush(&so->so_rcv); tp = tcp_usrclosed(tp); if (tp) (void) tcp_output(tp); } return (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. */ struct tcpcb * tcp_usrclosed(tp) register struct tcpcb *tp; { switch (tp->t_state) { case TCPS_CLOSED: case TCPS_LISTEN: #ifndef TTCP case TCPS_SYN_SENT: #endif tp->t_state = TCPS_CLOSED; tp = tcp_close(tp); break; #ifdef TTCP case TCPS_SYN_SENT: case TCPS_SYN_RECEIVED: tp->t_flags |= TF_NEEDFIN; break; #else case TCPS_SYN_RECEIVED: #endif 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); } /* * Sysctl for tcp variables. */ int tcp_sysctl(name, namelen, oldp, oldlenp, newp, newlen) int *name; u_int namelen; void *oldp; size_t *oldlenp; void *newp; size_t newlen; { extern int tcp_do_rfc1323; #ifdef TTCP extern int tcp_do_rfc1644; #endif extern int tcp_mssdflt; /* All sysctl names at this level are terminal. */ if (namelen != 1) return (ENOTDIR); switch (name[0]) { case TCPCTL_DO_RFC1323: return (sysctl_int(oldp, oldlenp, newp, newlen, &tcp_do_rfc1323)); #ifdef TTCP case TCPCTL_DO_RFC1644: return (sysctl_int(oldp, oldlenp, newp, newlen, &tcp_do_rfc1644)); #endif case TCPCTL_MSSDFLT: return (sysctl_int(oldp, oldlenp, newp, newlen, &tcp_mssdflt)); default: return (ENOPROTOOPT); } /* NOTREACHED */ }