/* * 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. 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 #include "proxy_common.h" /* patchable/settable parameters for tcp */ /* Don't do rfc1323 performance enhancements */ #define TCP_DO_RFC1323 0 /* * Tcp initialization */ void tcp_init(void) { tcp_iss = 1; /* wrong */ tcb.so_next = tcb.so_prev = &tcb; } /* * 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(struct tcpcb *tp) { struct socket *so = tp->t_socket; register struct tcpiphdr *n = &tp->t_template; n->ti_mbuf = NULL; n->ti_x1 = 0; n->ti_pr = IPPROTO_TCP; n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip)); n->ti_src = ip_seth(so->so_faddr_ip); n->ti_dst = ip_seth(so->so_laddr_ip); n->ti_sport = port_seth(so->so_faddr_port); n->ti_dport = port_seth(so->so_laddr_port); 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(struct tcpcb *tp, struct tcpiphdr *ti, struct mbuf *m, tcp_seq ack, tcp_seq 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 == NULL) { 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, ti->ti_src, ipaddr_t); xchg(ti->ti_dport, ti->ti_sport, port_t); #undef xchg } ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen)); tlen += sizeof (struct tcpiphdr); m->m_len = tlen; ti->ti_mbuf = NULL; 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 = IPDEFTTL; (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(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 = (struct tcpiphdr*)tp; tp->t_maxseg = TCP_MSS; 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 = TCPTV_SRTTDFLT << 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); STAT(tcpstat.tcps_drops++); } else STAT(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(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 = tcpfrag_list_first(tp); while (!tcpfrag_list_end(t, tp)) { t = tcpiphdr_next(t); m = tcpiphdr_prev(t)->ti_mbuf; remque(tcpiphdr2qlink(tcpiphdr_prev(t))); 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 = NULL; soisfdisconnected(so); /* clobber input socket cache if we're closing the cached connection */ if (so == tcp_last_so) tcp_last_so = &tcb; socket_close(so->s); sbfree(&so->so_rcv); sbfree(&so->so_snd); sofree(so); STAT(tcpstat.tcps_closed++); return ((struct tcpcb *)0); } #ifdef notdef 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. */ 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(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); } static void tcp_proxy_event( struct socket* so, int s, ProxyEvent event ) { so->so_state &= ~SS_PROXIFIED; if (event == PROXY_EVENT_CONNECTED) { so->s = s; so->so_state &= ~(SS_ISFCONNECTING); } else { so->so_state = SS_NOFDREF; } /* continue the connect */ tcp_input(NULL, sizeof(struct ip), so); } /* Tests if an IP address corresponds to a special Qemu service (eg, the DNS * server or the gateway - see ctl.h) and if so, rewrites it with the real * address of the service. */ int is_qemu_special_address(unsigned long dst_addr, unsigned long *redir_addr) { if ((dst_addr & 0xffffff00) == special_addr_ip) { /* It's an alias */ int last_byte = dst_addr & 0xff; if (CTL_IS_DNS(last_byte)) *redir_addr = dns_addr[last_byte - CTL_DNS]; else *redir_addr = loopback_addr_ip; return 1; } return 0; } /* * 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(struct socket *so) { int ret=0; int try_proxy = 0; SockAddress sockaddr; unsigned long sock_ip; int sock_port; int redirect_happened = 0; /* for logging new src ip/port after connect */ DEBUG_CALL("tcp_fconnect"); DEBUG_ARG("so = %lx", (long )so); /* when true, a connection that otherwise would be dropped will instead be * redirected to the sink ('-net-forward-tcp2sink') */ int forward_dropped_to_sink = 0; time_t timestamp = time(NULL); /*-------------------------------------------------------------*/ /* User mode network stack restrictions */ if (slirp_should_drop(so->so_faddr_ip, so->so_faddr_port, IPPROTO_TCP)) { /* If forwarding to sink is enabled, don't actually drop it */ if (slirp_should_forward_dropped_tcp2sink()) { slirp_drop_log( "About to be dropped TCP allowed to sink: " "0x%08lx:0x%04x -> 0x%08lx:0x%04x %ld\n", so->so_laddr_ip, so->so_laddr_port, so->so_faddr_ip, so->so_faddr_port, timestamp ); forward_dropped_to_sink = 1; } else { slirp_drop_log( "Dropped TCP: 0x%08lx:0x%04x -> 0x%08lx:0x%04x %ld\n", so->so_laddr_ip, so->so_laddr_port, so->so_faddr_ip, so->so_faddr_port, timestamp ); //errno = ENETUNREACH; errno = ECONNREFUSED; return -1; } } else { slirp_drop_log( "Allowed TCP: 0x%08lx:0x%04x -> 0x%08lx:0x%04x %ld\n", so->so_laddr_ip, so->so_laddr_port, so->so_faddr_ip, so->so_faddr_port, timestamp ); } /*-------------------------------------------------------------*/ if ((ret=so->s=socket_create_inet(SOCKET_STREAM)) >= 0) { int s = so->s; socket_set_nonblock(s); socket_set_xreuseaddr(s); socket_set_oobinline(s); if (forward_dropped_to_sink) { /* This connection would normally be dropped, but since forwarding of * dropped connections is enabled, redirect it to the sink */ sock_ip = slirp_get_tcp_sink_ip(); sock_port= slirp_get_tcp_sink_port(); redirect_happened = 1; } else { /* An allowed connection */ unsigned long faddr; int fport; /* Determine if the connection should be redirected * due to a -net-forward rule */ /* faddr and fport are modified only on success */ if (slirp_should_net_forward(so->so_faddr_ip, so->so_faddr_port, &faddr, &fport)) { redirect_happened = 1; sock_ip = faddr; /* forced dst addr */ sock_port= fport; /* forced dst port */ } /* Determine if this is a connection to a special qemu service, * and change the destination address accordingly. * 'faddr' is modified only on success */ else if (is_qemu_special_address(so->so_faddr_ip, &faddr)) { /* We keep the original destination port. If a special service * listens on a different port than the standard, then appropriate * forwarding should be set up using -net-forward, e.g., as it is * the case with Mawler's DNS traffic, which is redirected to the * special DNS port: * -net-forward 0.0.0.0:0.0.0.0:53:127.0.0.1:21737 */ sock_ip = faddr; /* real DNS/gateway addr */ sock_port= so->so_faddr_port;/* original dst port */ } /* A normal connection - keep the original destination addr/port */ else { try_proxy = 1; sock_ip = so->so_faddr_ip; /* original dst addr */ sock_port= so->so_faddr_port; /* original dst port */ } } DEBUG_MISC((dfd, " connect()ing, addr=%s, proxy=%d\n", sock_address_to_string(&sockaddr), try_proxy)); sock_address_init_inet( &sockaddr, sock_ip, sock_port ); if (try_proxy) { if (!proxy_manager_add(&sockaddr, SOCKET_STREAM, (ProxyEventFunc) tcp_proxy_event, so)) { soisfconnecting(so); so->s = -1; so->so_state |= SS_PROXIFIED; return 0; } } /* We don't care what port we get */ socket_connect(s, &sockaddr); if (redirect_happened) { SockAddress local_addr; if (socket_get_address(s, &local_addr)) { fprintf (stderr, "Warning: tcp_fconnect: could not get socket name\n"); } slirp_drop_log( "Redirected TCP: orig 0x%08lx:0x%04x -> 0x%08lx:0x%04x " "new 0x%08lx:0x%04x -> 0x%08lx:0x%04x %ld\n", so->so_laddr_ip, so->so_laddr_port, so->so_faddr_ip, so->so_laddr_port, sock_address_get_ip(&local_addr), sock_address_get_port(&local_addr), sock_ip, sock_port, timestamp ); } /* * 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(struct socket *inso) { struct socket *so; SockAddress addr; uint32_t addr_ip; struct tcpcb *tp; int s; 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 */ socket_close(socket_accept(inso->s, NULL)); return; } if (tcp_attach(so) < 0) { free(so); /* NOT sofree */ return; } so->so_laddr_ip = inso->so_laddr_ip; so->so_laddr_port = inso->so_laddr_port; } (void) tcp_mss(sototcpcb(so), 0); if ((s = socket_accept(inso->s, &addr)) < 0) { tcp_close(sototcpcb(so)); /* This will sofree() as well */ return; } socket_set_nonblock(s); socket_set_xreuseaddr(s); socket_set_oobinline(s); socket_set_nodelay(s); so->so_faddr_port = sock_address_get_port(&addr); addr_ip = sock_address_get_ip(&addr); so->so_faddr_ip = addr_ip; /* Translate connections from localhost to the real hostname */ if (addr_ip == 0 || addr_ip == loopback_addr_ip) so->so_faddr_ip = alias_addr_ip; /* Close the accept() socket, set right state */ if (inso->so_state & SS_FACCEPTONCE) { socket_close(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 */ STAT(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(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 */ static const 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} }; #ifdef CONFIG_QEMU static #endif struct emu_t *tcpemu = NULL; /* * Return TOS according to the above table */ u_int8_t tcp_tos(struct socket *so) { int i = 0; struct emu_t *emup; while(tcptos[i].tos) { if ((tcptos[i].fport && so->so_faddr_port == tcptos[i].fport) || (tcptos[i].lport && so->so_laddr_port == 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 && (so->so_faddr_port == emup->fport)) || (emup->lport && (so->so_laddr_port == emup->lport))) { so->so_emu = emup->emu; return emup->tos; } } return 0; } #if 0 int do_echo = -1; #endif /* * 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(struct socket *so, struct mbuf *m) { u_int n1, n2, n3, n4, n5, n6; char buff[257]; 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; SockAddress addr; 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, "%u%*[ ,]%u", &n1, &n2) == 2) { /* n2 is the one on our host */ for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) { if (tmpso->so_laddr_ip == so->so_laddr_ip && tmpso->so_laddr_port == n2 && tmpso->so_faddr_ip == so->so_faddr_ip && tmpso->so_faddr_port == n1) { if (socket_get_address(tmpso->s, &addr) == 0) n2 = sock_address_get_port(&addr); break; } } } so_rcv->sb_cc = snprintf(so_rcv->sb_data, so_rcv->sb_datalen, "%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; } case EMU_FTP: /* ftp */ *(m->m_data+m->m_len) = 0; /* NUL terminate for strstr */ if ((bptr = (char *)strstr(m->m_data, "ORT")) != NULL) { /* * Need to emulate the PORT command */ x = sscanf(bptr, "ORT %u,%u,%u,%u,%u,%u\r\n%256[^\177]", &n1, &n2, &n3, &n4, &n5, &n6, buff); if (x < 6) return 1; laddr = (n1 << 24) | (n2 << 16) | (n3 << 8) | (n4); lport = (n5 << 8) | (n6); if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL) return 1; n6 = so->so_faddr_port; n5 = (n6 >> 8) & 0xff; n6 &= 0xff; laddr = so->so_faddr_ip; n1 = ((laddr >> 24) & 0xff); n2 = ((laddr >> 16) & 0xff); n3 = ((laddr >> 8) & 0xff); n4 = (laddr & 0xff); m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len, "ORT %d,%d,%d,%d,%d,%d\r\n%s", n1, n2, n3, n4, n5, n6, x==7?buff:""); return 1; } else if ((bptr = (char *)strstr(m->m_data, "27 Entering")) != NULL) { /* * Need to emulate the PASV response */ x = sscanf(bptr, "27 Entering Passive Mode (%u,%u,%u,%u,%u,%u)\r\n%256[^\177]", &n1, &n2, &n3, &n4, &n5, &n6, buff); if (x < 6) return 1; laddr = (n1 << 24) | (n2 << 16) | (n3 << 8) | (n4); lport = (n5 << 8) | (n6); if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL) return 1; n6 = so->so_faddr_port; n5 = (n6 >> 8) & 0xff; n6 &= 0xff; laddr = so->so_faddr_ip; n1 = ((laddr >> 24) & 0xff); n2 = ((laddr >> 16) & 0xff); n3 = ((laddr >> 8) & 0xff); n4 = (laddr & 0xff); m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_hdr.mh_size - m->m_len, "27 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n%s", n1, n2, n3, n4, n5, n6, x==7?buff:""); return 1; } return 1; case EMU_KSH: /* * The kshell (Kerberos rsh) and shell services both pass * a local port port number to carry signals to the server * and stderr to the client. It is passed at the beginning * of the connection as a NUL-terminated decimal ASCII string. */ so->so_emu = 0; for (lport = 0, i = 0; i < m->m_len-1; ++i) { if (m->m_data[i] < '0' || m->m_data[i] > '9') return 1; /* invalid number */ lport *= 10; lport += m->m_data[i] - '0'; } if (m->m_data[m->m_len-1] == '\0' && lport != 0 && (so = solisten(0, so->so_laddr_ip, lport, SS_FACCEPTONCE)) != NULL) m->m_len = snprintf(m->m_data, m->m_hdr.mh_size, "%d", so->so_faddr_port) + 1; return 1; case EMU_IRC: /* * Need to emulate DCC CHAT, DCC SEND and DCC MOVE */ *(m->m_data+m->m_len) = 0; /* NULL terminate the string for strstr */ if ((bptr = (char *)strstr(m->m_data, "DCC")) == NULL) return 1; /* The %256s is for the broken mIRC */ if (sscanf(bptr, "DCC CHAT %256s %u %u", buff, &laddr, &lport) == 3) { if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL) return 1; m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_hdr.mh_size, "DCC CHAT chat %lu %u%c\n", (unsigned long) so->so_faddr_ip, so->so_faddr_port, 1); } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) { if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL) return 1; m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_hdr.mh_size, "DCC SEND %s %u %u %u%c\n", buff, so->so_faddr_ip, so->so_faddr_port, n1, 1); } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) { if ((so = solisten(0, laddr, lport, SS_FACCEPTONCE)) == NULL) return 1; m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_hdr.mh_size, "DCC MOVE %s %lu %u %u%c\n", buff, (unsigned long)so->so_faddr_ip, so->so_faddr_port, n1, 1); } return 1; case EMU_REALAUDIO: /* * RealAudio emulation - JP. We must try to parse the incoming * data and try to find the two characters that contain the * port number. Then we redirect an udp port and replace the * number with the real port we got. * * The 1.0 beta versions of the player are not supported * any more. * * A typical packet for player version 1.0 (release version): * * 0000:50 4E 41 00 05 * 0000:00 01 00 02 1B D7 00 00 67 E6 6C DC 63 00 12 50 .....×..gælÜc..P * 0010:4E 43 4C 49 45 4E 54 20 31 30 31 20 41 4C 50 48 NCLIENT 101 ALPH * 0020:41 6C 00 00 52 00 17 72 61 66 69 6C 65 73 2F 76 Al..R..rafiles/v * 0030:6F 61 2F 65 6E 67 6C 69 73 68 5F 2E 72 61 79 42 oa/english_.rayB * * Now the port number 0x1BD7 is found at offset 0x04 of the * Now the port number 0x1BD7 is found at offset 0x04 of the * second packet. This time we received five bytes first and * then the rest. You never know how many bytes you get. * * A typical packet for player version 2.0 (beta): * * 0000:50 4E 41 00 06 00 02 00 00 00 01 00 02 1B C1 00 PNA...........Á. * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .guxõc..Win2.0.0 * 0020:2E 35 6C 00 00 52 00 1C 72 61 66 69 6C 65 73 2F .5l..R..rafiles/ * 0030:77 65 62 73 69 74 65 2F 32 30 72 65 6C 65 61 73 website/20releas * 0040:65 2E 72 61 79 53 00 00 06 36 42 e.rayS...6B * * Port number 0x1BC1 is found at offset 0x0d. * * This is just a horrible switch statement. Variable ra tells * us where we're going. */ bptr = m->m_data; while (bptr < m->m_data + m->m_len) { u_short p; static int ra = 0; char ra_tbl[4]; ra_tbl[0] = 0x50; ra_tbl[1] = 0x4e; ra_tbl[2] = 0x41; ra_tbl[3] = 0; switch (ra) { case 0: case 2: case 3: if (*bptr++ != ra_tbl[ra]) { ra = 0; continue; } break; case 1: /* * We may get 0x50 several times, ignore them */ if (*bptr == 0x50) { ra = 1; bptr++; continue; } else if (*bptr++ != ra_tbl[ra]) { ra = 0; continue; } break; case 4: /* * skip version number */ bptr++; break; case 5: /* * The difference between versions 1.0 and * 2.0 is here. For future versions of * the player this may need to be modified. */ if (*(bptr + 1) == 0x02) bptr += 8; else bptr += 4; break; case 6: /* This is the field containing the port * number that RA-player is listening to. */ lport = (((u_char*)bptr)[0] << 8) + ((u_char *)bptr)[1]; if (lport < 6970) lport += 256; /* don't know why */ if (lport < 6970 || lport > 7170) return 1; /* failed */ /* try to get udp port between 6970 - 7170 */ for (p = 6970; p < 7071; p++) { if (udp_listen( p, so->so_laddr_ip, lport, SS_FACCEPTONCE)) { break; } } if (p == 7071) p = 0; *(u_char *)bptr++ = (p >> 8) & 0xff; *(u_char *)bptr++ = p & 0xff; ra = 0; return 1; /* port redirected, we're done */ break; default: ra = 0; } ra++; } return 1; default: /* Ooops, not emulated, won't call tcp_emu again */ so->so_emu = 0; return 1; } } /* * Do misc. config of SLiRP while its running. * Return 0 if this connections is to be closed, 1 otherwise, * return 2 if this is a command-line connection */ int tcp_ctl(struct socket *so) { struct sbuf *sb = &so->so_snd; int command; struct ex_list *ex_ptr; int do_pty; // struct socket *tmpso; DEBUG_CALL("tcp_ctl"); DEBUG_ARG("so = %lx", (long )so); #if 0 /* * Check if they're authorised */ if (ctl_addr_ip && (ctl_addr_ip == -1 || (so->so_laddr_ip != ctl_addr_ip))) { sb->sb_cc = sprintf(sb->sb_wptr,"Error: Permission denied.\r\n"); sb->sb_wptr += sb->sb_cc; return 0; } #endif command = (so->so_faddr_ip & 0xff); switch(command) { default: /* Check for exec's */ /* * Check if it's pty_exec */ for (ex_ptr = exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) { if (ex_ptr->ex_fport == so->so_faddr_port && command == ex_ptr->ex_addr) { if (ex_ptr->ex_pty == 3) { so->s = -1; so->extra = (void *)ex_ptr->ex_exec; return 1; } do_pty = ex_ptr->ex_pty; goto do_exec; } } /* * Nothing bound.. */ /* tcp_fconnect(so); */ /* FALLTHROUGH */ case CTL_ALIAS: sb->sb_cc = snprintf(sb->sb_wptr, sb->sb_datalen - (sb->sb_wptr - sb->sb_data), "Error: No application configured.\r\n"); sb->sb_wptr += sb->sb_cc; return(0); do_exec: DEBUG_MISC((dfd, " executing %s \n",ex_ptr->ex_exec)); return(fork_exec(so, ex_ptr->ex_exec, do_pty)); #if 0 case CTL_CMD: for (tmpso = tcb.so_next; tmpso != &tcb; tmpso = tmpso->so_next) { if (tmpso->so_emu == EMU_CTL && !(tmpso->so_tcpcb? (tmpso->so_tcpcb->t_state & (TCPS_TIME_WAIT|TCPS_LAST_ACK)) :0)) { /* Ooops, control connection already active */ sb->sb_cc = sprintf(sb->sb_wptr,"Sorry, already connected.\r\n"); sb->sb_wptr += sb->sb_cc; return 0; } } so->so_emu = EMU_CTL; ctl_password_ok = 0; sb->sb_cc = sprintf(sb->sb_wptr, "Slirp command-line ready (type \"help\" for help).\r\nSlirp> "); sb->sb_wptr += sb->sb_cc; do_echo=-1; return(2); #endif } }