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tcp_usrreq.c
1478 lines (1306 loc) · 36.8 KB
/
tcp_usrreq.c
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/* $OpenBSD: tcp_usrreq.c,v 1.196 2022/08/27 20:28:01 mvs Exp $ */
/* $NetBSD: tcp_usrreq.c,v 1.20 1996/02/13 23:44:16 christos Exp $ */
/*
* 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. 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.
*
* @(#)COPYRIGHT 1.1 (NRL) 17 January 1995
*
* NRL grants permission for redistribution and use in source and binary
* forms, with or without modification, of the software and documentation
* created at NRL 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 acknowledgements:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* This product includes software developed at the Information
* Technology Division, US Naval Research Laboratory.
* 4. Neither the name of the NRL nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THE SOFTWARE PROVIDED BY NRL IS PROVIDED BY NRL 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 NRL 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.
*
* The views and conclusions contained in the software and documentation
* are those of the authors and should not be interpreted as representing
* official policies, either expressed or implied, of the US Naval
* Research Laboratory (NRL).
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/domain.h>
#include <sys/kernel.h>
#include <sys/pool.h>
#include <sys/proc.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/route.h>
#include <netinet/in.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#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/tcp_debug.h>
#ifdef INET6
#include <netinet6/in6_var.h>
#endif
#ifndef TCP_SENDSPACE
#define TCP_SENDSPACE 1024*16
#endif
u_int tcp_sendspace = TCP_SENDSPACE;
#ifndef TCP_RECVSPACE
#define TCP_RECVSPACE 1024*16
#endif
u_int tcp_recvspace = TCP_RECVSPACE;
u_int tcp_autorcvbuf_inc = 16 * 1024;
const struct pr_usrreqs tcp_usrreqs = {
.pru_usrreq = tcp_usrreq,
.pru_attach = tcp_attach,
.pru_detach = tcp_detach,
.pru_bind = tcp_bind,
.pru_listen = tcp_listen,
.pru_connect = tcp_connect,
.pru_accept = tcp_accept,
.pru_disconnect = tcp_disconnect,
.pru_shutdown = tcp_shutdown,
.pru_rcvd = tcp_rcvd,
.pru_send = tcp_send,
};
static int pr_slowhz = PR_SLOWHZ;
const struct sysctl_bounded_args tcpctl_vars[] = {
{ TCPCTL_SLOWHZ, &pr_slowhz, SYSCTL_INT_READONLY },
{ TCPCTL_RFC1323, &tcp_do_rfc1323, 0, 1 },
{ TCPCTL_KEEPINITTIME, &tcptv_keep_init, 1, 3 * TCPTV_KEEP_INIT },
{ TCPCTL_KEEPIDLE, &tcp_keepidle, 1, 5 * TCPTV_KEEP_IDLE },
{ TCPCTL_KEEPINTVL, &tcp_keepintvl, 1, 3 * TCPTV_KEEPINTVL },
{ TCPCTL_SACK, &tcp_do_sack, 0, 1 },
{ TCPCTL_MSSDFLT, &tcp_mssdflt, TCP_MSS, 65535 },
{ TCPCTL_RSTPPSLIMIT, &tcp_rst_ppslim, 1, 1000 * 1000 },
{ TCPCTL_ACK_ON_PUSH, &tcp_ack_on_push, 0, 1 },
#ifdef TCP_ECN
{ TCPCTL_ECN, &tcp_do_ecn, 0, 1 },
#endif
{ TCPCTL_SYN_CACHE_LIMIT, &tcp_syn_cache_limit, 1, 1000 * 1000 },
{ TCPCTL_SYN_BUCKET_LIMIT, &tcp_syn_bucket_limit, 1, INT_MAX },
{ TCPCTL_RFC3390, &tcp_do_rfc3390, 0, 2 },
{ TCPCTL_ALWAYS_KEEPALIVE, &tcp_always_keepalive, 0, 1 },
};
struct inpcbtable tcbtable;
int tcp_fill_info(struct tcpcb *, struct socket *, struct mbuf *);
int tcp_ident(void *, size_t *, void *, size_t, int);
static inline int tcp_sogetpcb(struct socket *, struct inpcb **,
struct tcpcb **);
static inline int
tcp_sogetpcb(struct socket *so, struct inpcb **rinp, struct tcpcb **rtp)
{
struct inpcb *inp;
struct tcpcb *tp;
/*
* 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 subsidiary (struct tcpcb).
*/
if ((inp = sotoinpcb(so)) == NULL || (tp = intotcpcb(inp)) == NULL) {
if (so->so_error)
return so->so_error;
return EINVAL;
}
*rinp = inp;
*rtp = tp;
return 0;
}
/*
* 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(struct socket *so, int req, struct mbuf *m, struct mbuf *nam,
struct mbuf *control, struct proc *p)
{
struct inpcb *inp;
struct tcpcb *otp = NULL, *tp;
int error = 0;
short ostate;
if (req == PRU_CONTROL) {
#ifdef INET6
if (sotopf(so) == PF_INET6)
return in6_control(so, (u_long)m, (caddr_t)nam,
(struct ifnet *)control);
else
#endif /* INET6 */
return (in_control(so, (u_long)m, (caddr_t)nam,
(struct ifnet *)control));
}
soassertlocked(so);
if (control && control->m_len) {
error = EINVAL;
goto release;
}
if ((error = tcp_sogetpcb(so, &inp, &tp)))
goto release;
if (so->so_options & SO_DEBUG) {
otp = tp;
ostate = tp->t_state;
}
switch (req) {
/*
* Create a TCP connection between two sockets.
*/
case PRU_CONNECT2:
error = EOPNOTSUPP;
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;
break;
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 (((long)nam & MSG_PEEK) == 0)
tp->t_oobflags ^= (TCPOOB_HAVEDATA | TCPOOB_HADDATA);
break;
case PRU_SENDOOB:
if (sbspace(so, &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.
*/
sbappendstream(so, &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:
#ifdef INET6
if (inp->inp_flags & INP_IPV6)
in6_setsockaddr(inp, nam);
else
#endif
in_setsockaddr(inp, nam);
break;
case PRU_PEERADDR:
#ifdef INET6
if (inp->inp_flags & INP_IPV6)
in6_setpeeraddr(inp, nam);
else
#endif
in_setpeeraddr(inp, nam);
break;
default:
panic("tcp_usrreq");
}
if (otp)
tcp_trace(TA_USER, ostate, tp, otp, NULL, req, 0);
return (error);
release:
if (req != PRU_RCVD && req != PRU_RCVOOB && req != PRU_SENSE) {
m_freem(control);
m_freem(m);
}
return (error);
}
/*
* Export internal TCP state information via a struct tcp_info without
* leaking any sensitive information. Sequence numbers are reported
* relative to the initial sequence number.
*/
int
tcp_fill_info(struct tcpcb *tp, struct socket *so, struct mbuf *m)
{
struct proc *p = curproc;
struct tcp_info *ti;
u_int t = 1000000 / PR_SLOWHZ;
if (sizeof(*ti) > MLEN) {
MCLGETL(m, M_WAITOK, sizeof(*ti));
if (!ISSET(m->m_flags, M_EXT))
return ENOMEM;
}
ti = mtod(m, struct tcp_info *);
m->m_len = sizeof(*ti);
memset(ti, 0, 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;
}
#ifdef TCP_ECN
if (tp->t_flags & TF_ECN_PERMIT)
ti->tcpi_options |= TCPI_OPT_ECN;
#endif
ti->tcpi_rto = tp->t_rxtcur * t;
ti->tcpi_snd_mss = tp->t_maxseg;
ti->tcpi_rcv_mss = tp->t_peermss;
ti->tcpi_last_data_sent = (tcp_now - tp->t_sndtime) * t;
ti->tcpi_last_ack_sent = (tcp_now - tp->t_sndacktime) * t;
ti->tcpi_last_data_recv = (tcp_now - tp->t_rcvtime) * t;
ti->tcpi_last_ack_recv = (tcp_now - tp->t_rcvacktime) * t;
ti->tcpi_rtt = ((uint64_t)tp->t_srtt * t) >>
(TCP_RTT_SHIFT + TCP_RTT_BASE_SHIFT);
ti->tcpi_rttvar = ((uint64_t)tp->t_rttvar * t) >>
(TCP_RTTVAR_SHIFT + TCP_RTT_BASE_SHIFT);
ti->tcpi_snd_ssthresh = tp->snd_ssthresh;
ti->tcpi_snd_cwnd = tp->snd_cwnd;
ti->tcpi_rcv_space = tp->rcv_wnd;
/*
* Provide only minimal information for unprivileged processes.
*/
if (suser(p) != 0)
return 0;
/* FreeBSD-specific extension fields for tcp_info. */
ti->tcpi_snd_wnd = tp->snd_wnd;
ti->tcpi_snd_nxt = tp->snd_nxt - tp->iss;
ti->tcpi_rcv_nxt = tp->rcv_nxt - tp->irs;
/* missing tcpi_toe_tid */
ti->tcpi_snd_rexmitpack = tp->t_sndrexmitpack;
ti->tcpi_rcv_ooopack = tp->t_rcvoopack;
ti->tcpi_snd_zerowin = tp->t_sndzerowin;
/* OpenBSD extensions */
ti->tcpi_rttmin = tp->t_rttmin * t;
ti->tcpi_max_sndwnd = tp->max_sndwnd;
ti->tcpi_rcv_adv = tp->rcv_adv - tp->irs;
ti->tcpi_rcv_up = tp->rcv_up - tp->irs;
ti->tcpi_snd_una = tp->snd_una - tp->iss;
ti->tcpi_snd_up = tp->snd_up - tp->iss;
ti->tcpi_snd_wl1 = tp->snd_wl1 - tp->iss;
ti->tcpi_snd_wl2 = tp->snd_wl2 - tp->iss;
ti->tcpi_snd_max = tp->snd_max - tp->iss;
ti->tcpi_ts_recent = tp->ts_recent; /* XXX value from the wire */
ti->tcpi_ts_recent_age = (tcp_now - tp->ts_recent_age) * t;
ti->tcpi_rfbuf_cnt = tp->rfbuf_cnt;
ti->tcpi_rfbuf_ts = (tcp_now - tp->rfbuf_ts) * t;
ti->tcpi_so_rcv_sb_cc = so->so_rcv.sb_cc;
ti->tcpi_so_rcv_sb_hiwat = so->so_rcv.sb_hiwat;
ti->tcpi_so_rcv_sb_lowat = so->so_rcv.sb_lowat;
ti->tcpi_so_rcv_sb_wat = so->so_rcv.sb_wat;
ti->tcpi_so_snd_sb_cc = so->so_snd.sb_cc;
ti->tcpi_so_snd_sb_hiwat = so->so_snd.sb_hiwat;
ti->tcpi_so_snd_sb_lowat = so->so_snd.sb_lowat;
ti->tcpi_so_snd_sb_wat = so->so_snd.sb_wat;
return 0;
}
int
tcp_ctloutput(int op, struct socket *so, int level, int optname,
struct mbuf *m)
{
int error = 0;
struct inpcb *inp;
struct tcpcb *tp;
int i;
inp = sotoinpcb(so);
if (inp == NULL)
return (ECONNRESET);
if (level != IPPROTO_TCP) {
switch (so->so_proto->pr_domain->dom_family) {
#ifdef INET6
case PF_INET6:
error = ip6_ctloutput(op, so, level, optname, m);
break;
#endif /* INET6 */
case PF_INET:
error = ip_ctloutput(op, so, level, optname, m);
break;
default:
error = EAFNOSUPPORT; /*?*/
break;
}
return (error);
}
tp = intotcpcb(inp);
switch (op) {
case PRCO_SETOPT:
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_NOPUSH:
if (m == NULL || m->m_len < sizeof (int))
error = EINVAL;
else if (*mtod(m, int *))
tp->t_flags |= TF_NOPUSH;
else if (tp->t_flags & TF_NOPUSH) {
tp->t_flags &= ~TF_NOPUSH;
if (TCPS_HAVEESTABLISHED(tp->t_state))
error = tcp_output(tp);
}
break;
case TCP_MAXSEG:
if (m == NULL || m->m_len < sizeof (int)) {
error = EINVAL;
break;
}
i = *mtod(m, int *);
if (i > 0 && i <= tp->t_maxseg)
tp->t_maxseg = i;
else
error = EINVAL;
break;
case TCP_SACK_ENABLE:
if (m == NULL || m->m_len < sizeof (int)) {
error = EINVAL;
break;
}
if (TCPS_HAVEESTABLISHED(tp->t_state)) {
error = EPERM;
break;
}
if (tp->t_flags & TF_SIGNATURE) {
error = EPERM;
break;
}
if (*mtod(m, int *))
tp->sack_enable = 1;
else
tp->sack_enable = 0;
break;
#ifdef TCP_SIGNATURE
case TCP_MD5SIG:
if (m == NULL || m->m_len < sizeof (int)) {
error = EINVAL;
break;
}
if (TCPS_HAVEESTABLISHED(tp->t_state)) {
error = EPERM;
break;
}
if (*mtod(m, int *)) {
tp->t_flags |= TF_SIGNATURE;
tp->sack_enable = 0;
} else
tp->t_flags &= ~TF_SIGNATURE;
break;
#endif /* TCP_SIGNATURE */
default:
error = ENOPROTOOPT;
break;
}
break;
case PRCO_GETOPT:
switch (optname) {
case TCP_NODELAY:
m->m_len = sizeof(int);
*mtod(m, int *) = tp->t_flags & TF_NODELAY;
break;
case TCP_NOPUSH:
m->m_len = sizeof(int);
*mtod(m, int *) = tp->t_flags & TF_NOPUSH;
break;
case TCP_MAXSEG:
m->m_len = sizeof(int);
*mtod(m, int *) = tp->t_maxseg;
break;
case TCP_SACK_ENABLE:
m->m_len = sizeof(int);
*mtod(m, int *) = tp->sack_enable;
break;
case TCP_INFO:
error = tcp_fill_info(tp, so, m);
break;
#ifdef TCP_SIGNATURE
case TCP_MD5SIG:
m->m_len = sizeof(int);
*mtod(m, int *) = tp->t_flags & TF_SIGNATURE;
break;
#endif
default:
error = ENOPROTOOPT;
break;
}
break;
}
return (error);
}
/*
* Attach TCP protocol to socket, allocating
* internet protocol control block, tcp control block,
* buffer space, and entering LISTEN state to accept connections.
*/
int
tcp_attach(struct socket *so, int proto)
{
struct tcpcb *tp;
struct inpcb *inp;
int error;
if (so->so_pcb)
return EISCONN;
if (so->so_snd.sb_hiwat == 0 || so->so_rcv.sb_hiwat == 0 ||
sbcheckreserve(so->so_snd.sb_wat, tcp_sendspace) ||
sbcheckreserve(so->so_rcv.sb_wat, tcp_recvspace)) {
error = soreserve(so, tcp_sendspace, tcp_recvspace);
if (error)
return (error);
}
NET_ASSERT_LOCKED();
error = in_pcballoc(so, &tcbtable);
if (error)
return (error);
inp = sotoinpcb(so);
tp = tcp_newtcpcb(inp);
if (tp == NULL) {
unsigned 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;
#ifdef INET6
/* we disallow IPv4 mapped address completely. */
if (inp->inp_flags & INP_IPV6)
tp->pf = PF_INET6;
else
tp->pf = PF_INET;
#else
tp->pf = PF_INET;
#endif
if ((so->so_options & SO_LINGER) && so->so_linger == 0)
so->so_linger = TCP_LINGERTIME;
if (so->so_options & SO_DEBUG)
tcp_trace(TA_USER, TCPS_CLOSED, tp, tp, NULL, PRU_ATTACH, 0);
return (0);
}
int
tcp_detach(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *otp = NULL, *tp;
int error = 0;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG) {
otp = tp;
ostate = tp->t_state;
}
/*
* Detach 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.
*/
tp = tcp_dodisconnect(tp);
if (otp)
tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_DETACH, 0);
return (error);
}
/*
* Give the socket an address.
*/
int
tcp_bind(struct socket *so, struct mbuf *nam, struct proc *p)
{
struct inpcb *inp;
struct tcpcb *tp;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG)
ostate = tp->t_state;
error = in_pcbbind(inp, nam, p);
if (so->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_BIND, 0);
return (error);
}
/*
* Prepare to accept connections.
*/
int
tcp_listen(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp, *otp = NULL;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG) {
otp = tp;
ostate = tp->t_state;
}
if (inp->inp_lport == 0)
if ((error = in_pcbbind(inp, NULL, curproc)))
goto out;
/*
* If the in_pcbbind() above is called, the tp->pf
* should still be whatever it was before.
*/
tp->t_state = TCPS_LISTEN;
out:
if (otp)
tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_LISTEN, 0);
return (error);
}
/*
* 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.
*/
int
tcp_connect(struct socket *so, struct mbuf *nam)
{
struct inpcb *inp;
struct tcpcb *tp, *otp = NULL;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG) {
otp = tp;
ostate = tp->t_state;
}
#ifdef INET6
if (inp->inp_flags & INP_IPV6) {
struct sockaddr_in6 *sin6;
if ((error = in6_nam2sin6(nam, &sin6)))
goto out;
if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr) ||
IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr)) {
error = EINVAL;
goto out;
}
error = in6_pcbconnect(inp, nam);
} else
#endif /* INET6 */
{
struct sockaddr_in *sin;
if ((error = in_nam2sin(nam, &sin)))
goto out;
if ((sin->sin_addr.s_addr == INADDR_ANY) ||
(sin->sin_addr.s_addr == INADDR_BROADCAST) ||
IN_MULTICAST(sin->sin_addr.s_addr) ||
in_broadcast(sin->sin_addr, inp->inp_rtableid)) {
error = EINVAL;
goto out;
}
error = in_pcbconnect(inp, nam);
}
if (error)
goto out;
tp->t_template = tcp_template(tp);
if (tp->t_template == 0) {
in_pcbdisconnect(inp);
error = ENOBUFS;
goto out;
}
so->so_state |= SS_CONNECTOUT;
/* Compute window scaling to request. */
tcp_rscale(tp, sb_max);
soisconnecting(so);
tcpstat_inc(tcps_connattempt);
tp->t_state = TCPS_SYN_SENT;
TCP_TIMER_ARM(tp, TCPT_KEEP, tcptv_keep_init);
tcp_set_iss_tsm(tp);
tcp_sendseqinit(tp);
tp->snd_last = tp->snd_una;
error = tcp_output(tp);
out:
if (otp)
tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_CONNECT, 0);
return (error);
}
/*
* Accept a connection. Essentially all the work is done at higher
* levels; just return the address of the peer, storing through addr.
*/
int
tcp_accept(struct socket *so, struct mbuf *nam)
{
struct inpcb *inp;
struct tcpcb *tp;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG)
ostate = tp->t_state;
#ifdef INET6
if (inp->inp_flags & INP_IPV6)
in6_setpeeraddr(inp, nam);
else
#endif
in_setpeeraddr(inp, nam);
if (so->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_ACCEPT, 0);
return (error);
}
/*
* 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.
*/
int
tcp_disconnect(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp, *otp = NULL;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG) {
otp = tp;
ostate = tp->t_state;
}
tp = tcp_dodisconnect(tp);
if (otp)
tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_DISCONNECT, 0);
return (0);
}
/*
* Mark the connection as being incapable of further output.
*/
int
tcp_shutdown(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp, *otp = NULL;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG) {
otp = tp;
ostate = tp->t_state;
}
if (so->so_state & SS_CANTSENDMORE)
goto out;
socantsendmore(so);
tp = tcp_usrclosed(tp);
if (tp)
error = tcp_output(tp);
out:
if (otp)
tcp_trace(TA_USER, ostate, tp, otp, NULL, PRU_SHUTDOWN, 0);
return (error);
}
/*
* After a receive, possibly send window update to peer.
*/
int
tcp_rcvd(struct socket *so)
{
struct inpcb *inp;
struct tcpcb *tp;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
return (error);
if (so->so_options & SO_DEBUG)
ostate = tp->t_state;
/*
* soreceive() calls this function when a user receives
* ancillary data on a listening socket. We don't call
* tcp_output in such a case, since there is no header
* template for a listening socket and hence the kernel
* will panic.
*/
if ((so->so_state & (SS_ISCONNECTED|SS_ISCONNECTING)) != 0)
(void) tcp_output(tp);
if (so->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_RCVD, 0);
return (0);
}
/*
* Do a send by putting data in output queue and updating urgent
* marker if URG set. Possibly send more data.
*/
int
tcp_send(struct socket *so, struct mbuf *m, struct mbuf *nam,
struct mbuf *control)
{
struct inpcb *inp;
struct tcpcb *tp;
int error;
short ostate;
soassertlocked(so);
if ((error = tcp_sogetpcb(so, &inp, &tp)))
goto out;
if (so->so_options & SO_DEBUG)
ostate = tp->t_state;
sbappendstream(so, &so->so_snd, m);
m = NULL;
error = tcp_output(tp);
if (so->so_options & SO_DEBUG)
tcp_trace(TA_USER, ostate, tp, tp, NULL, PRU_SEND, 0);
out:
m_freem(control);
m_freem(m);
return (error);
}
/*
* 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_dodisconnect(struct tcpcb *tp)
{
struct socket *so = tp->t_inpcb->inp_socket;
if (TCPS_HAVEESTABLISHED(tp->t_state) == 0)
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->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.