/* * 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 * $FreeBSD$ */ #include "opt_tcpdebug.h" #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[]; /* XXX ??? */ static int tcp_attach __P((struct socket *, struct proc *)); static int tcp_connect __P((struct tcpcb *, struct sockaddr *, struct proc *)); static struct tcpcb * tcp_disconnect __P((struct tcpcb *)); static struct tcpcb * tcp_usrclosed __P((struct tcpcb *)); #ifdef TCPDEBUG #define TCPDEBUG0 int ostate #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, 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); } /* * 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); } /* * 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; } prison_remote_ip(p, 0, &sinp->sin_addr.s_addr); if ((error = tcp_connect(tp, nam, p)) != 0) goto out; error = tcp_output(tp); COMMON_END(PRU_CONNECT); } /* * 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; COMMON_START(); in_setpeeraddr(so, nam); COMMON_END(PRU_ACCEPT); } /* * 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; 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; } 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 * initialize maxseg/maxopd using peer's cached * MSS. */ error = tcp_connect(tp, nam, p); 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. */ socantsendmore(so); tp = tcp_usrclosed(tp); } if (tp != NULL) { if (flags & PRUS_MORETOCOME) tp->t_flags |= TF_MORETOCOME; error = tcp_output(tp); if (flags & PRUS_MORETOCOME) tp->t_flags &= ~TF_MORETOCOME; } } else { if (sbspace(&so->so_snd) < -512) { 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. */ 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 * initialize maxseg/maxopd using peer's cached * MSS. */ error = tcp_connect(tp, nam, p); if (error) goto out; tp->snd_wnd = TTCP_CLIENT_SND_WND; tcp_mss(tp, -1); } tp->snd_up = tp->snd_una + so->so_snd.sb_cc; tp->t_force = 1; error = tcp_output(tp); tp->t_force = 0; } COMMON_END((flags & PRUS_OOB) ? PRU_SENDOOB : ((flags & PRUS_EOF) ? PRU_SEND_EOF : PRU_SEND)); } /* * Abort the TCP. */ static int tcp_usr_abort(struct socket *so) { int s = splnet(); int error = 0; struct inpcb *inp = sotoinpcb(so); struct tcpcb *tp; COMMON_START(); tp = tcp_drop(tp, ECONNABORTED); COMMON_END(PRU_ABORT); } /* * Receive out-of-band data. */ static int tcp_usr_rcvoob(struct socket *so, struct mbuf *m, int flags) { int s = splnet(); int error = 0; struct inpcb *inp = sotoinpcb(so); struct tcpcb *tp; COMMON_START(); if ((so->so_oobmark == 0 && (so->so_state & SS_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); COMMON_END(PRU_RCVOOB); } /* xxx - should be const */ struct pr_usrreqs tcp_usrreqs = { tcp_usr_abort, tcp_usr_accept, tcp_usr_attach, tcp_usr_bind, tcp_usr_connect, pru_connect2_notsupp, in_control, tcp_usr_detach, tcp_usr_disconnect, tcp_usr_listen, in_setpeeraddr, tcp_usr_rcvd, tcp_usr_rcvoob, tcp_usr_send, pru_sense_null, tcp_usr_shutdown, in_setsockaddr, sosend, soreceive, sopoll }; /* * 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. */ static int tcp_connect(tp, nam, p) register struct tcpcb *tp; struct sockaddr *nam; struct proc *p; { struct inpcb *inp = tp->t_inpcb, *oinp; struct socket *so = inp->inp_socket; struct tcpcb *otp; struct sockaddr_in *sin = (struct sockaddr_in *)nam; struct sockaddr_in *ifaddr; struct rmxp_tao *taop; struct rmxp_tao tao_noncached; int error; if (inp->inp_lport == 0) { error = in_pcbbind(inp, (struct sockaddr *)0, p); 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); if (error) return error; oinp = in_pcblookup_hash(inp->inp_pcbinfo, sin->sin_addr, sin->sin_port, inp->inp_laddr.s_addr != INADDR_ANY ? inp->inp_laddr : ifaddr->sin_addr, inp->inp_lport, 0, NULL); if (oinp) { if (oinp != inp && (otp = intotcpcb(oinp)) != NULL && otp->t_state == TCPS_TIME_WAIT && (ticks - otp->t_starttime) < tcp_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; in_pcbrehash(inp); 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; callout_reset(tp->tt_keep, tcp_keepinit, tcp_timer_keep, tp); tp->iss = tcp_iss; tcp_iss += TCP_ISSINCR/2; tcp_sendseqinit(tp); /* * Generate a CC value for this connection and * check whether CC or CCnew should be used. */ if ((taop = tcp_gettaocache(tp->t_inpcb)) == NULL) { taop = &tao_noncached; bzero(taop, sizeof(*taop)); } tp->cc_send = CC_INC(tcp_ccgen); if (taop->tao_ccsent != 0 && CC_GEQ(tp->cc_send, taop->tao_ccsent)) { taop->tao_ccsent = tp->cc_send; } else { taop->tao_ccsent = 0; tp->t_flags |= TF_SENDCCNEW; } return 0; } /* * The new sockopt interface makes it possible for us to block in the * copyin/out step (if we take a page fault). Taking a page fault at * splnet() is probably a Bad Thing. (Since sockets and pcbs both now * use TSM, there probably isn't any need for this function to run at * splnet() any more. This needs more examination.) */ int tcp_ctloutput(so, sopt) struct socket *so; struct sockopt *sopt; { int error, opt, optval, s; struct inpcb *inp; struct tcpcb *tp; error = 0; s = splnet(); /* XXX */ inp = sotoinpcb(so); if (inp == NULL) { splx(s); return (ECONNRESET); } if (sopt->sopt_level != IPPROTO_TCP) { error = ip_ctloutput(so, sopt); splx(s); return (error); } tp = intotcpcb(inp); switch (sopt->sopt_dir) { case SOPT_SET: switch (sopt->sopt_name) { case TCP_NODELAY: case TCP_NOOPT: case TCP_NOPUSH: error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; switch (sopt->sopt_name) { case TCP_NODELAY: opt = TF_NODELAY; break; case TCP_NOOPT: opt = TF_NOOPT; break; case TCP_NOPUSH: opt = TF_NOPUSH; break; default: opt = 0; /* dead code to fool gcc */ break; } if (optval) tp->t_flags |= opt; else tp->t_flags &= ~opt; break; case TCP_MAXSEG: error = sooptcopyin(sopt, &optval, sizeof optval, sizeof optval); if (error) break; if (optval > 0 && optval <= tp->t_maxseg) tp->t_maxseg = optval; else error = EINVAL; break; default: error = ENOPROTOOPT; break; } break; case SOPT_GET: switch (sopt->sopt_name) { case TCP_NODELAY: optval = tp->t_flags & TF_NODELAY; break; case TCP_MAXSEG: optval = tp->t_maxseg; break; case TCP_NOOPT: optval = tp->t_flags & TF_NOOPT; break; case TCP_NOPUSH: optval = tp->t_flags & TF_NOPUSH; break; default: error = ENOPROTOOPT; break; } if (error == 0) error = sooptcopyout(sopt, &optval, sizeof optval); 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). */ u_long tcp_sendspace = 1024*16; SYSCTL_INT(_net_inet_tcp, TCPCTL_SENDSPACE, sendspace, CTLFLAG_RW, &tcp_sendspace , 0, "Maximum outgoing TCP datagram size"); u_long tcp_recvspace = 1024*16; SYSCTL_INT(_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(so, p) struct socket *so; struct proc *p; { 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, &tcbinfo, p); if (error) return (error); inp = sotoinpcb(so); inp->inp_vflag |= INP_IPV4; 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). */ static 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. */ static struct tcpcb * tcp_usrclosed(tp) register struct tcpcb *tp; { switch (tp->t_state) { case TCPS_CLOSED: case TCPS_LISTEN: tp->t_state = TCPS_CLOSED; tp = tcp_close(tp); 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 && tp->t_state >= TCPS_FIN_WAIT_2) { soisdisconnected(tp->t_inpcb->inp_socket); /* To prevent the connection hanging in FIN_WAIT_2 forever. */ if (tp->t_state == TCPS_FIN_WAIT_2) callout_reset(tp->tt_2msl, tcp_maxidle, tcp_timer_2msl, tp); } return (tp); }