/* * 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. */ #include "slirp.h" #if BX_NETWORKING && BX_NETMOD_SLIRP_NEW /* patchable/settable parameters for tcp */ /* Don't do rfc1323 performance enhancements */ #define TCP_DO_RFC1323 0 /* * Tcp initialization */ void tcp_init(Slirp *slirp) { slirp->tcp_iss = 1; /* wrong */ slirp->tcb.so_next = slirp->tcb.so_prev = &slirp->tcb; slirp->tcp_last_so = &slirp->tcb; } void tcp_cleanup(Slirp *slirp) { while (slirp->tcb.so_next != &slirp->tcb) { tcp_close(sototcpcb(slirp->tcb.so_next)); } } /* * 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. */ 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 = 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(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 = %p", tp); DEBUG_ARG("ti = %p", ti); DEBUG_ARG("m = %p", 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 (!tp || (m = m_get(tp->t_socket->slirp)) == NULL) return; tlen = 0; 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, uint32_t); xchg(ti->ti_dport, ti->ti_sport, uint16_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((uint16_t) (win >> tp->rcv_scale)); else ti->ti_win = htons((uint16_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) { 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); } 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; Slirp *slirp = so->slirp; 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_free(m); } free(tp); so->so_tcpcb = NULL; /* clobber input socket cache if we're closing the cached connection */ if (so == slirp->tcp_last_so) slirp->tcp_last_so = &slirp->tcb; closesocket(so->s); sbfree(&so->so_rcv); sbfree(&so->so_snd); sofree(so); return ((struct tcpcb *)0); } /* * 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; } 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(struct socket *so) { Slirp *slirp = so->slirp; int ret=0; DEBUG_CALL("tcp_fconnect"); DEBUG_ARG("so = %lx", (long )so); if( (ret = so->s = qemu_socket(AF_INET,SOCK_STREAM,0)) >= 0) { int opt, s=so->s; struct sockaddr_in addr; qemu_set_nonblock(s); socket_set_fast_reuse(s); opt = 1; qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt)); addr.sin_family = AF_INET; if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) == slirp->vnetwork_addr.s_addr) { /* It's an alias */ if (so->so_faddr.s_addr == slirp->vnameserver_addr.s_addr) { if (get_dns_addr(&addr.sin_addr) < 0) addr.sin_addr = loopback_addr; } else { addr.sin_addr = loopback_addr; } } 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(struct socket *inso) { Slirp *slirp = inso->slirp; struct socket *so; struct sockaddr_in addr; socklen_t 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 { so = socreate(slirp); if (so == 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; } tcp_mss(sototcpcb(so), 0); s = accept(inso->s, (struct sockaddr *)&addr, &addrlen); if (s < 0) { tcp_close(sototcpcb(so)); /* This will sofree() as well */ return; } qemu_set_nonblock(s); socket_set_fast_reuse(s); opt = 1; qemu_setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int)); socket_set_nodelay(s); 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_mask) == (loopback_addr.s_addr & loopback_mask)) { so->so_faddr = slirp->vhost_addr; } /* Close the accept() socket, set right state */ if (inso->so_state & SS_FACCEPTONCE) { /* If we only accept once, close the accept() socket */ closesocket(so->s); /* Don't select it yet, even though we have an FD */ /* if it's not FACCEPTONCE, it's already NOFDREF */ so->so_state = SS_NOFDREF; } so->s = s; so->so_state |= SS_INCOMING; so->so_iptos = tcp_tos(so); tp = sototcpcb(so); tcp_template(tp); tp->t_state = TCPS_SYN_SENT; tp->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT; tp->iss = slirp->tcp_iss; slirp->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, &so->slirp->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} }; static struct emu_t *tcpemu = NULL; /* * Return TOS according to the above table */ uint8_t tcp_tos(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; } /* * 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) { Slirp *slirp = so->slirp; u_int n1, n2, n3, n4, n5, n6; char buff[257]; uint32_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; socklen_t 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, "%u%*[ ,]%u", &n1, &n2) == 2) { HTONS(n1); HTONS(n2); /* n2 is the one on our host */ for (tmpso = slirp->tcb.so_next; tmpso != &slirp->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 = 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 = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4)); lport = htons((n5 << 8) | (n6)); if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr, lport, SS_FACCEPTONCE)) == NULL) { return 1; } n6 = ntohs(so->so_fport); n5 = (n6 >> 8) & 0xff; n6 &= 0xff; laddr = ntohl(so->so_faddr.s_addr); 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_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 = htonl((n1 << 24) | (n2 << 16) | (n3 << 8) | (n4)); lport = htons((n5 << 8) | (n6)); if ((so = tcp_listen(slirp, INADDR_ANY, 0, laddr, lport, SS_FACCEPTONCE)) == NULL) { return 1; } n6 = ntohs(so->so_fport); n5 = (n6 >> 8) & 0xff; n6 &= 0xff; laddr = ntohl(so->so_faddr.s_addr); 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_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 = tcp_listen(slirp, INADDR_ANY, 0, so->so_laddr.s_addr, htons(lport), SS_FACCEPTONCE)) != NULL) m->m_len = snprintf(m->m_data, m->m_size, "%d", ntohs(so->so_fport)) + 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 = tcp_listen(slirp, INADDR_ANY, 0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL) { return 1; } m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_size, "DCC CHAT chat %lu %u%c\n", (unsigned long)ntohl(so->so_faddr.s_addr), ntohs(so->so_fport), 1); } else if (sscanf(bptr, "DCC SEND %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) { if ((so = tcp_listen(slirp, INADDR_ANY, 0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL) { return 1; } m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_size, "DCC SEND %s %lu %u %u%c\n", buff, (unsigned long)ntohl(so->so_faddr.s_addr), ntohs(so->so_fport), n1, 1); } else if (sscanf(bptr, "DCC MOVE %256s %u %u %u", buff, &laddr, &lport, &n1) == 4) { if ((so = tcp_listen(slirp, INADDR_ANY, 0, htonl(laddr), htons(lport), SS_FACCEPTONCE)) == NULL) { return 1; } m->m_len = bptr - m->m_data; /* Adjust length */ m->m_len += snprintf(bptr, m->m_size, "DCC MOVE %s %lu %u %u%c\n", buff, (unsigned long)ntohl(so->so_faddr.s_addr), ntohs(so->so_fport), 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 ........g.l.c..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............. * 0010:00 67 75 78 F5 63 00 0A 57 69 6E 32 2E 30 2E 30 .gux.c..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(slirp, INADDR_ANY, htons(p), so->so_laddr.s_addr, htons(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) { Slirp *slirp = so->slirp; struct sbuf *sb = &so->so_snd; struct ex_list *ex_ptr; int do_pty; DEBUG_CALL("tcp_ctl"); DEBUG_ARG("so = %lx", (long )so); if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) { /* Check if it's pty_exec */ for (ex_ptr = slirp->exec_list; ex_ptr; ex_ptr = ex_ptr->ex_next) { if (ex_ptr->ex_fport == so->so_fport && so->so_faddr.s_addr == ex_ptr->ex_addr.s_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; DEBUG_MISC((dfd, " executing %s\n", ex_ptr->ex_exec)); return fork_exec(so, ex_ptr->ex_exec, do_pty); } } } 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; } #endif