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tcp_subr.c
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tcp_subr.c
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/*
* Copyright (c) 1982, 1986, 1988, 1990, 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_subr.c 8.1 (Berkeley) 6/10/93
* tcp_subr.c,v 1.5 1994/10/08 22:39:58 phk Exp
*/
/*
* Changes and additions relating to SLiRP
* Copyright (c) 1995 Danny Gasparovski.
*
* Please read the file COPYRIGHT for the
* terms and conditions of the copyright.
*/
#define WANT_SYS_IOCTL_H
#include <slirp.h>
/* patchable/settable parameters for tcp */
int tcp_mssdflt = TCP_MSS;
int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ;
int tcp_do_rfc1323 = 0; /* Don't do rfc1323 performance enhancements */
int tcp_rcvspace; /* You may want to change this */
int tcp_sndspace; /* Keep small if you have an error prone link */
/*
* Tcp initialization
*/
void
tcp_init()
{
tcp_iss = 1; /* wrong */
tcb.so_next = tcb.so_prev = &tcb;
/* tcp_rcvspace = our Window we advertise to the remote */
tcp_rcvspace = TCP_RCVSPACE;
tcp_sndspace = TCP_SNDSPACE;
/* Make sure tcp_sndspace is at least 2*MSS */
if (tcp_sndspace < 2*(min(if_mtu, if_mru) - sizeof(struct tcpiphdr)))
tcp_sndspace = 2*(min(if_mtu, if_mru) - sizeof(struct tcpiphdr));
}
/*
* Create template to be used to send tcp packets on a connection.
* Call after host entry created, fills
* in a skeletal tcp/ip header, minimizing the amount of work
* necessary when the connection is used.
*/
/* struct tcpiphdr * */
void
tcp_template(tp)
struct tcpcb *tp;
{
struct socket *so = tp->t_socket;
register struct tcpiphdr *n = &tp->t_template;
n->ti_next = n->ti_prev = 0;
n->ti_x1 = 0;
n->ti_pr = IPPROTO_TCP;
n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip));
n->ti_src = so->so_faddr;
n->ti_dst = so->so_laddr;
n->ti_sport = so->so_fport;
n->ti_dport = so->so_lport;
n->ti_seq = 0;
n->ti_ack = 0;
n->ti_x2 = 0;
n->ti_off = 5;
n->ti_flags = 0;
n->ti_win = 0;
n->ti_sum = 0;
n->ti_urp = 0;
}
/*
* Send a single message to the TCP at address specified by
* the given TCP/IP header. If m == 0, then we make a copy
* of the tcpiphdr at ti and send directly to the addressed host.
* This is used to force keep alive messages out using the TCP
* template for a connection tp->t_template. If flags are given
* then we send a message back to the TCP which originated the
* segment ti, and discard the mbuf containing it and any other
* attached mbufs.
*
* In any case the ack and sequence number of the transmitted
* segment are as specified by the parameters.
*/
void
tcp_respond(tp, ti, m, ack, seq, flags)
struct tcpcb *tp;
register struct tcpiphdr *ti;
register struct mbuf *m;
tcp_seq ack, seq;
int flags;
{
register int tlen;
int win = 0;
DEBUG_CALL("tcp_respond");
DEBUG_ARG("tp = %lx", (long)tp);
DEBUG_ARG("ti = %lx", (long)ti);
DEBUG_ARG("m = %lx", (long)m);
DEBUG_ARG("ack = %u", ack);
DEBUG_ARG("seq = %u", seq);
DEBUG_ARG("flags = %x", flags);
if (tp)
win = sbspace(&tp->t_socket->so_rcv);
if (m == 0) {
if ((m = m_get()) == NULL)
return;
#ifdef TCP_COMPAT_42
tlen = 1;
#else
tlen = 0;
#endif
m->m_data += if_maxlinkhdr;
*mtod(m, struct tcpiphdr *) = *ti;
ti = mtod(m, struct tcpiphdr *);
flags = TH_ACK;
} else {
/*
* ti points into m so the next line is just making
* the mbuf point to ti
*/
m->m_data = (caddr_t)ti;
m->m_len = sizeof (struct tcpiphdr);
tlen = 0;
#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_int32_t);
xchg(ti->ti_dport, ti->ti_sport, u_int16_t);
#undef xchg
}
ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen));
tlen += sizeof (struct tcpiphdr);
m->m_len = tlen;
ti->ti_next = ti->ti_prev = 0;
ti->ti_x1 = 0;
ti->ti_seq = htonl(seq);
ti->ti_ack = htonl(ack);
ti->ti_x2 = 0;
ti->ti_off = sizeof (struct tcphdr) >> 2;
ti->ti_flags = flags;
if (tp)
ti->ti_win = htons((u_int16_t) (win >> tp->rcv_scale));
else
ti->ti_win = htons((u_int16_t)win);
ti->ti_urp = 0;
ti->ti_sum = 0;
ti->ti_sum = cksum(m, tlen);
((struct ip *)ti)->ip_len = tlen;
if(flags & TH_RST)
((struct ip *)ti)->ip_ttl = MAXTTL;
else
((struct ip *)ti)->ip_ttl = ip_defttl;
(void) ip_output((struct socket *)0, m);
}
/*
* Create a new TCP control block, making an
* empty reassembly queue and hooking it to the argument
* protocol control block.
*/
struct tcpcb *
tcp_newtcpcb(so)
struct socket *so;
{
register struct tcpcb *tp;
tp = (struct tcpcb *)malloc(sizeof(*tp));
if (tp == NULL)
return ((struct tcpcb *)0);
memset((char *) tp, 0, sizeof(struct tcpcb));
tp->seg_next = tp->seg_prev = (tcpiphdrp_32)tp;
tp->t_maxseg = tcp_mssdflt;
tp->t_flags = tcp_do_rfc1323 ? (TF_REQ_SCALE|TF_REQ_TSTMP) : 0;
tp->t_socket = so;
/*
* Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no
* rtt estimate. Set rttvar so that srtt + 2 * rttvar gives
* reasonable initial retransmit time.
*/
tp->t_srtt = TCPTV_SRTTBASE;
tp->t_rttvar = tcp_rttdflt * PR_SLOWHZ << 2;
tp->t_rttmin = TCPTV_MIN;
TCPT_RANGESET(tp->t_rxtcur,
((TCPTV_SRTTBASE >> 2) + (TCPTV_SRTTDFLT << 2)) >> 1,
TCPTV_MIN, TCPTV_REXMTMAX);
tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT;
tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
tp->t_state = TCPS_CLOSED;
so->so_tcpcb = tp;
return (tp);
}
/*
* Drop a TCP connection, reporting
* the specified error. If connection is synchronized,
* then send a RST to peer.
*/
struct tcpcb *tcp_drop(struct tcpcb *tp, int err)
{
/* tcp_drop(tp, errno)
register struct tcpcb *tp;
int errno;
{
*/
DEBUG_CALL("tcp_drop");
DEBUG_ARG("tp = %lx", (long)tp);
DEBUG_ARG("errno = %d", errno);
if (TCPS_HAVERCVDSYN(tp->t_state)) {
tp->t_state = TCPS_CLOSED;
(void) tcp_output(tp);
tcpstat.tcps_drops++;
} else
tcpstat.tcps_conndrops++;
/* if (errno == ETIMEDOUT && tp->t_softerror)
* errno = tp->t_softerror;
*/
/* so->so_error = errno; */
return (tcp_close(tp));
}
/*
* Close a TCP control block:
* discard all space held by the tcp
* discard internet protocol block
* wake up any sleepers
*/
struct tcpcb *
tcp_close(tp)
register struct tcpcb *tp;
{
register struct tcpiphdr *t;
struct socket *so = tp->t_socket;
register struct mbuf *m;
DEBUG_CALL("tcp_close");
DEBUG_ARG("tp = %lx", (long )tp);
/* free the reassembly queue, if any */
t = (struct tcpiphdr *) tp->seg_next;
while (t != (struct tcpiphdr *)tp) {
t = (struct tcpiphdr *)t->ti_next;
m = (struct mbuf *) REASS_MBUF((struct tcpiphdr *)t->ti_prev);
remque_32((struct tcpiphdr *) t->ti_prev);
m_freem(m);
}
/* It's static */
/* if (tp->t_template)
* (void) m_free(dtom(tp->t_template));
*/
/* free(tp, M_PCB); */
free(tp);
so->so_tcpcb = 0;
soisfdisconnected(so);
/* clobber input socket cache if we're closing the cached connection */
if (so == tcp_last_so)
tcp_last_so = &tcb;
closesocket(so->s);
sbfree(&so->so_rcv);
sbfree(&so->so_snd);
sofree(so);
tcpstat.tcps_closed++;
return ((struct tcpcb *)0);
}
void
tcp_drain()
{
/* XXX */
}
/*
* When a source quench is received, close congestion window
* to one segment. We will gradually open it again as we proceed.
*/
#ifdef notdef
void
tcp_quench(i, errno)
int errno;
{
struct tcpcb *tp = intotcpcb(inp);
if (tp)
tp->snd_cwnd = tp->t_maxseg;
}
#endif /* notdef */
/*
* TCP protocol interface to socket abstraction.
*/
/*
* 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.
*/
void
tcp_sockclosed(tp)
struct tcpcb *tp;
{
DEBUG_CALL("tcp_sockclosed");
DEBUG_ARG("tp = %lx", (long)tp);
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;
}
/* soisfdisconnecting(tp->t_socket); */
if (tp && tp->t_state >= TCPS_FIN_WAIT_2)
soisfdisconnected(tp->t_socket);
if (tp)
tcp_output(tp);
}
/*
* Connect to a host on the Internet
* Called by tcp_input
* Only do a connect, the tcp fields will be set in tcp_input
* return 0 if there's a result of the connect,
* else return -1 means we're still connecting
* The return value is almost always -1 since the socket is
* nonblocking. Connect returns after the SYN is sent, and does
* not wait for ACK+SYN.
*/
int tcp_fconnect(so)
struct socket *so;
{
int ret=0;
DEBUG_CALL("tcp_fconnect");
DEBUG_ARG("so = %lx", (long )so);
if( (ret=so->s=socket(AF_INET,SOCK_STREAM,0)) >= 0) {
int opt, s=so->s;
struct sockaddr_in addr;
fd_nonblock(s);
opt = 1;
setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(opt ));
opt = 1;
setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(opt ));
addr.sin_family = AF_INET;
if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
/* It's an alias */
switch(ntohl(so->so_faddr.s_addr) & 0xff) {
case CTL_DNS:
addr.sin_addr = dns_addr;
break;
case CTL_ALIAS:
default:
addr.sin_addr = loopback_addr;
break;
}
} else
addr.sin_addr = so->so_faddr;
addr.sin_port = so->so_fport;
DEBUG_MISC((dfd, " connect()ing, addr.sin_port=%d, "
"addr.sin_addr.s_addr=%.16s\n",
ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));
/* We don't care what port we get */
ret = connect(s,(struct sockaddr *)&addr,sizeof (addr));
/*
* If it's not in progress, it failed, so we just return 0,
* without clearing SS_NOFDREF
*/
soisfconnecting(so);
}
return(ret);
}
/*
* Accept the socket and connect to the local-host
*
* We have a problem. The correct thing to do would be
* to first connect to the local-host, and only if the
* connection is accepted, then do an accept() here.
* But, a) we need to know who's trying to connect
* to the socket to be able to SYN the local-host, and
* b) we are already connected to the foreign host by
* the time it gets to accept(), so... We simply accept
* here and SYN the local-host.
*/
void
tcp_connect(inso)
struct socket *inso;
{
struct socket *so;
struct sockaddr_in addr;
int addrlen = sizeof(struct sockaddr_in);
struct tcpcb *tp;
int s, opt;
DEBUG_CALL("tcp_connect");
DEBUG_ARG("inso = %lx", (long)inso);
/*
* If it's an SS_ACCEPTONCE socket, no need to socreate()
* another socket, just use the accept() socket.
*/
if (inso->so_state & SS_FACCEPTONCE) {
/* FACCEPTONCE already have a tcpcb */
so = inso;
} else {
if ((so = socreate()) == NULL) {
/* If it failed, get rid of the pending connection */
closesocket(accept(inso->s,(struct sockaddr *)&addr,&addrlen));
return;
}
if (tcp_attach(so) < 0) {
free(so); /* NOT sofree */
return;
}
so->so_laddr = inso->so_laddr;
so->so_lport = inso->so_lport;
}
(void) tcp_mss(sototcpcb(so), 0);
if ((s = accept(inso->s,(struct sockaddr *)&addr,&addrlen)) < 0) {
tcp_close(sototcpcb(so)); /* This will sofree() as well */
return;
}
fd_nonblock(s);
opt = 1;
setsockopt(s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));
opt = 1;
setsockopt(s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int));
so->so_fport = addr.sin_port;
so->so_faddr = addr.sin_addr;
/* Translate connections from localhost to the real hostname */
if (so->so_faddr.s_addr == 0 || so->so_faddr.s_addr == loopback_addr.s_addr)
so->so_faddr = our_addr;
/* Close the accept() socket, set right state */
if (inso->so_state & SS_FACCEPTONCE) {
closesocket(so->s); /* If we only accept once, close the accept() socket */
so->so_state = SS_NOFDREF; /* Don't select it yet, even though we have an FD */
/* if it's not FACCEPTONCE, it's already NOFDREF */
}
so->s = s;
so->so_iptos = tcp_tos(so);
tp = sototcpcb(so);
tcp_template(tp);
/* 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); */ /* NOFDREF used instead */
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);
tcp_output(tp);
}
/*
* Attach a TCPCB to a socket.
*/
int
tcp_attach(so)
struct socket *so;
{
if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL)
return -1;
insque(so, &tcb);
return 0;
}
/*
* Set the socket's type of service field
*/
struct tos_t tcptos[] = {
{0, 20, IPTOS_THROUGHPUT, 0}, /* ftp data */
{21, 21, IPTOS_LOWDELAY, EMU_FTP}, /* ftp control */
{0, 23, IPTOS_LOWDELAY, 0}, /* telnet */
{0, 80, IPTOS_THROUGHPUT, 0}, /* WWW */
{0, 513, IPTOS_LOWDELAY, EMU_RLOGIN|EMU_NOCONNECT}, /* rlogin */
{0, 514, IPTOS_LOWDELAY, EMU_RSH|EMU_NOCONNECT}, /* shell */
{0, 544, IPTOS_LOWDELAY, EMU_KSH}, /* kshell */
{0, 543, IPTOS_LOWDELAY, 0}, /* klogin */
{0, 6667, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC */
{0, 6668, IPTOS_THROUGHPUT, EMU_IRC}, /* IRC undernet */
{0, 7070, IPTOS_LOWDELAY, EMU_REALAUDIO }, /* RealAudio control */
{0, 113, IPTOS_LOWDELAY, EMU_IDENT }, /* identd protocol */
{0, 0, 0, 0}
};
struct emu_t *tcpemu = 0;
/*
* Return TOS according to the above table
*/
u_int8_t
tcp_tos(so)
struct socket *so;
{
int i = 0;
struct emu_t *emup;
while(tcptos[i].tos) {
if ((tcptos[i].fport && (ntohs(so->so_fport) == tcptos[i].fport)) ||
(tcptos[i].lport && (ntohs(so->so_lport) == tcptos[i].lport))) {
so->so_emu = tcptos[i].emu;
return tcptos[i].tos;
}
i++;
}
/* Nope, lets see if there's a user-added one */
for (emup = tcpemu; emup; emup = emup->next) {
if ((emup->fport && (ntohs(so->so_fport) == emup->fport)) ||
(emup->lport && (ntohs(so->so_lport) == emup->lport))) {
so->so_emu = emup->emu;
return emup->tos;
}
}
return 0;
}
int do_echo = -1;
/*
* Emulate programs that try and connect to us
* This includes ftp (the data connection is
* initiated by the server) and IRC (DCC CHAT and
* DCC SEND) for now
*
* NOTE: It's possible to crash SLiRP by sending it
* unstandard strings to emulate... if this is a problem,
* more checks are needed here
*
* XXX Assumes the whole command came in one packet
*
* XXX Some ftp clients will have their TOS set to
* LOWDELAY and so Nagel will kick in. Because of this,
* we'll get the first letter, followed by the rest, so
* we simply scan for ORT instead of PORT...
* DCC doesn't have this problem because there's other stuff
* in the packet before the DCC command.
*
* Return 1 if the mbuf m is still valid and should be
* sbappend()ed
*
* NOTE: if you return 0 you MUST m_free() the mbuf!
*/
int
tcp_emu(so, m)
struct socket *so;
struct mbuf *m;
{
u_int n1, n2, n3, n4, n5, n6;
char buff[256];
u_int32_t laddr;
u_int lport;
char *bptr;
DEBUG_CALL("tcp_emu");
DEBUG_ARG("so = %lx", (long)so);
DEBUG_ARG("m = %lx", (long)m);
switch(so->so_emu) {
int x, i;
case EMU_IDENT:
/*
* Identification protocol as per rfc-1413
*/
{
struct socket *tmpso;
struct sockaddr_in addr;
int addrlen = sizeof(struct sockaddr_in);
struct sbuf *so_rcv = &so->so_rcv;
memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
so_rcv->sb_wptr += m->m_len;
so_rcv->sb_rptr += m->m_len;
m->m_data[m->m_len] = 0; /* NULL terminate */
if (strchr(m->m_data, '\r') || strchr(m->m_data, '\n')) {
if (sscanf(so_rcv->sb_data, "%d%*[ ,]%d", &n1, &n2) == 2) {
HTONS(n1);
HTONS(n2);
/* n2 is the one on our host */
for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) {
if (tmpso->so_laddr.s_addr == so->so_laddr.s_addr &&
tmpso->so_lport == n2 &&
tmpso->so_faddr.s_addr == so->so_faddr.s_addr &&
tmpso->so_fport == n1) {
if (getsockname(tmpso->s,
(struct sockaddr *)&addr, &addrlen) == 0)
n2 = ntohs(addr.sin_port);
break;
}
}
}
so_rcv->sb_cc = sprintf(so_rcv->sb_data, "%d,%d\r\n", n1, n2);
so_rcv->sb_rptr = so_rcv->sb_data;
so_rcv->sb_wptr = so_rcv->sb_data + so_rcv->sb_cc;
}
m_free(m);
return 0;
}
#if 0
case EMU_RLOGIN:
/*
* Rlogin emulation
* First we accumulate all the initial option negotiation,
* then fork_exec() rlogin according to the options
*/
{
int i, i2, n;
char *ptr;
char args[100];
char term[100];
struct sbuf *so_snd = &so->so_snd;
struct sbuf *so_rcv = &so->so_rcv;
/* First check if they have a priveladged port, or too much data has arrived */
if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
(m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
so_snd->sb_wptr += 18;
so_snd->sb_cc += 18;
tcp_sockclosed(sototcpcb(so));
m_free(m);
return 0;
}
/* Append the current data */
memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
so_rcv->sb_wptr += m->m_len;
so_rcv->sb_rptr += m->m_len;
m_free(m);
/*
* Check if we have all the initial options,
* and build argument list to rlogin while we're here
*/
n = 0;
ptr = so_rcv->sb_data;
args[0] = 0;
term[0] = 0;
while (ptr < so_rcv->sb_wptr) {
if (*ptr++ == 0) {
n++;
if (n == 2) {
sprintf(args, "rlogin -l %s %s",
ptr, inet_ntoa(so->so_faddr));
} else if (n == 3) {
i2 = so_rcv->sb_wptr - ptr;
for (i = 0; i < i2; i++) {
if (ptr[i] == '/') {
ptr[i] = 0;
#ifdef HAVE_SETENV
sprintf(term, "%s", ptr);
#else
sprintf(term, "TERM=%s", ptr);
#endif
ptr[i] = '/';
break;
}
}
}
}
}
if (n != 4)
return 0;
/* We have it, set our term variable and fork_exec() */
#ifdef HAVE_SETENV
setenv("TERM", term, 1);
#else
putenv(term);
#endif
fork_exec(so, args, 2);
term[0] = 0;
so->so_emu = 0;
/* And finally, send the client a 0 character */
so_snd->sb_wptr[0] = 0;
so_snd->sb_wptr++;
so_snd->sb_cc++;
return 0;
}
case EMU_RSH:
/*
* rsh emulation
* First we accumulate all the initial option negotiation,
* then rsh_exec() rsh according to the options
*/
{
int n;
char *ptr;
char *user;
char *args;
struct sbuf *so_snd = &so->so_snd;
struct sbuf *so_rcv = &so->so_rcv;
/* First check if they have a priveladged port, or too much data has arrived */
if (ntohs(so->so_lport) > 1023 || ntohs(so->so_lport) < 512 ||
(m->m_len + so_rcv->sb_wptr) > (so_rcv->sb_data + so_rcv->sb_datalen)) {
memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
so_snd->sb_wptr += 18;
so_snd->sb_cc += 18;
tcp_sockclosed(sototcpcb(so));
m_free(m);
return 0;
}
/* Append the current data */
memcpy(so_rcv->sb_wptr, m->m_data, m->m_len);
so_rcv->sb_wptr += m->m_len;
so_rcv->sb_rptr += m->m_len;
m_free(m);
/*
* Check if we have all the initial options,
* and build argument list to rlogin while we're here
*/
n = 0;
ptr = so_rcv->sb_data;
user="";
args="";
if (so->extra==NULL) {
struct socket *ns;
struct tcpcb* tp;
int port=atoi(ptr);
if (port <= 0) return 0;
if (port > 1023 || port < 512) {
memcpy(so_snd->sb_wptr, "Permission denied\n", 18);
so_snd->sb_wptr += 18;
so_snd->sb_cc += 18;
tcp_sockclosed(sototcpcb(so));
return 0;
}
if ((ns=socreate()) == NULL)
return 0;
if (tcp_attach(ns)<0) {
free(ns);
return 0;
}
ns->so_laddr=so->so_laddr;
ns->so_lport=htons(port);
(void) tcp_mss(sototcpcb(ns), 0);
ns->so_faddr=so->so_faddr;
ns->so_fport=htons(IPPORT_RESERVED-1); /* Use a fake port. */
if (ns->so_faddr.s_addr == 0 ||
ns->so_faddr.s_addr == loopback_addr.s_addr)
ns->so_faddr = our_addr;
ns->so_iptos = tcp_tos(ns);
tp = sototcpcb(ns);
tcp_template(tp);
/* 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++;
*/
/*soisfconnecting(ns);*/
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);
tcp_output(tp);
so->extra=ns;
}
while (ptr < so_rcv->sb_wptr) {
if (*ptr++ == 0) {
n++;
if (n == 2) {
user=ptr;
} else if (n == 3) {
args=ptr;
}
}
}
if (n != 4)
return 0;
rsh_exec(so,so->extra, user, inet_ntoa(so->so_faddr), args);
so->so_emu = 0;
so->extra=NULL;
/* And finally, send the client a 0 character */
so_snd->sb_wptr[0] = 0;
so_snd->sb_wptr++;
so_snd->sb_cc++;
return 0;
}
case EMU_CTL:
{
int num;
struct sbuf *so_snd = &so->so_snd;
struct sbuf *so_rcv = &so->so_rcv;
/*
* If there is binary data here, we save it in so->so_m
*/
if (!so->so_m) {
int rxlen;
char *rxdata;
rxdata=mtod(m, char *);
for (rxlen=m->m_len; rxlen; rxlen--) {
if (*rxdata++ & 0x80) {
so->so_m = m;
return 0;
}
}
} /* if(so->so_m==NULL) */
/*
* Append the line
*/
sbappendsb(so_rcv, m);
/* To avoid going over the edge of the buffer, we reset it */
if (so_snd->sb_cc == 0)
so_snd->sb_wptr = so_snd->sb_rptr = so_snd->sb_data;
/*
* A bit of a hack:
* If the first packet we get here is 1 byte long, then it
* was done in telnet character mode, therefore we must echo
* the characters as they come. Otherwise, we echo nothing,
* because in linemode, the line is already echoed
* XXX two or more control connections won't work
*/
if (do_echo == -1) {
if (m->m_len == 1) do_echo = 1;
else do_echo = 0;
}
if (do_echo) {
sbappendsb(so_snd, m);
m_free(m);
tcp_output(sototcpcb(so)); /* XXX */
} else
m_free(m);
num = 0;
while (num < so->so_rcv.sb_cc) {
if (*(so->so_rcv.sb_rptr + num) == '\n' ||
*(so->so_rcv.sb_rptr + num) == '\r') {
int n;
*(so_rcv->sb_rptr + num) = 0;
if (ctl_password && !ctl_password_ok) {
/* Need a password */
if (sscanf(so_rcv->sb_rptr, "pass %256s", buff) == 1) {
if (strcmp(buff, ctl_password) == 0) {
ctl_password_ok = 1;
n = sprintf(so_snd->sb_wptr,
"Password OK.\r\n");
goto do_prompt;
}
}
n = sprintf(so_snd->sb_wptr,
"Error: Password required, log on with \"pass PASSWORD\"\r\n");
goto do_prompt;
}
cfg_quitting = 0;
n = do_config(so_rcv->sb_rptr, so, PRN_SPRINTF);
if (!cfg_quitting) {
/* Register the printed data */
do_prompt:
so_snd->sb_cc += n;
so_snd->sb_wptr += n;
/* Add prompt */
n = sprintf(so_snd->sb_wptr, "Slirp> ");
so_snd->sb_cc += n;
so_snd->sb_wptr += n;
}
/* Drop so_rcv data */
so_rcv->sb_cc = 0;
so_rcv->sb_wptr = so_rcv->sb_rptr = so_rcv->sb_data;
tcp_output(sototcpcb(so)); /* Send the reply */
}
num++;
}
return 0;
}
#endif
case EMU_FTP: /* ftp */
*(m->m_data+m->m_len) = 0; /* NULL terminate for strstr */
if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) {
/*
* Need to emulate the PORT command
*/
x = sscanf(bptr, "ORT %d,%d,%d,%d,%d,%d\r\n%256[^\177]",
&n1, &n2, &n3, &n4, &n5, &n6, buff);
if (x < 6)
return 1;
laddr = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4));
lport = htons((n5 << 8) | (n6));
if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL)