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Diffstat (limited to 'slirp/src/tcp_subr.c')
| -rw-r--r-- | slirp/src/tcp_subr.c | 989 |
1 files changed, 989 insertions, 0 deletions
diff --git a/slirp/src/tcp_subr.c b/slirp/src/tcp_subr.c new file mode 100644 index 0000000000..1db59caa89 --- /dev/null +++ b/slirp/src/tcp_subr.c @@ -0,0 +1,989 @@ +/* + * 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" + +/* 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; + memset(&n->ti, 0, sizeof(n->ti)); + n->ti_x0 = 0; + switch (so->so_ffamily) { + case AF_INET: + n->ti_pr = IPPROTO_TCP; + n->ti_len = htons(sizeof(struct tcphdr)); + n->ti_src = so->so_faddr; + n->ti_dst = so->so_laddr; + n->ti_sport = so->so_fport; + n->ti_dport = so->so_lport; + break; + + case AF_INET6: + n->ti_nh6 = IPPROTO_TCP; + n->ti_len = htons(sizeof(struct tcphdr)); + n->ti_src6 = so->so_faddr6; + n->ti_dst6 = so->so_laddr6; + n->ti_sport = so->so_fport6; + n->ti_dport = so->so_lport6; + break; + + default: + g_assert_not_reached(); + } + + 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, unsigned short af) +{ + 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 *); + switch (af) { + case AF_INET: + ti->ti.ti_i4.ih_x1 = 0; + break; + case AF_INET6: + ti->ti.ti_i6.ih_x1 = 0; + break; + default: + g_assert_not_reached(); + } + flags = TH_ACK; + } else { + /* + * ti points into m so the next line is just making + * the mbuf point to ti + */ + m->m_data = (char *)ti; + + m->m_len = sizeof (struct tcpiphdr); + tlen = 0; +#define xchg(a,b,type) { type t; t=a; a=b; b=t; } + switch (af) { + case AF_INET: + xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, uint32_t); + xchg(ti->ti_dport, ti->ti_sport, uint16_t); + break; + case AF_INET6: + xchg(ti->ti_dst6, ti->ti_src6, struct in6_addr); + xchg(ti->ti_dport, ti->ti_sport, uint16_t); + break; + default: + g_assert_not_reached(); + } +#undef xchg + } + ti->ti_len = htons((uint16_t)(sizeof (struct tcphdr) + tlen)); + tlen += sizeof (struct tcpiphdr); + m->m_len = tlen; + + ti->ti_mbuf = NULL; + ti->ti_x0 = 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 tcpiphdr tcpiph_save = *(mtod(m, struct tcpiphdr *)); + struct ip *ip; + struct ip6 *ip6; + + switch (af) { + case AF_INET: + m->m_data += sizeof(struct tcpiphdr) - sizeof(struct tcphdr) + - sizeof(struct ip); + m->m_len -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr) + - sizeof(struct ip); + ip = mtod(m, struct ip *); + ip->ip_len = m->m_len; + ip->ip_dst = tcpiph_save.ti_dst; + ip->ip_src = tcpiph_save.ti_src; + ip->ip_p = tcpiph_save.ti_pr; + + if (flags & TH_RST) { + ip->ip_ttl = MAXTTL; + } else { + ip->ip_ttl = IPDEFTTL; + } + + ip_output(NULL, m); + break; + + case AF_INET6: + m->m_data += sizeof(struct tcpiphdr) - sizeof(struct tcphdr) + - sizeof(struct ip6); + m->m_len -= sizeof(struct tcpiphdr) - sizeof(struct tcphdr) + - sizeof(struct ip6); + ip6 = mtod(m, struct ip6 *); + ip6->ip_pl = tcpiph_save.ti_len; + ip6->ip_dst = tcpiph_save.ti_dst6; + ip6->ip_src = tcpiph_save.ti_src6; + ip6->ip_nh = tcpiph_save.ti_nh6; + + ip6_output(NULL, m, 0); + break; + + default: + g_assert_not_reached(); + } +} + +/* + * 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 = (so->so_ffamily == AF_INET) ? TCP_MSS : TCP6_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 = %p", 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 = %p", 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; + so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque); + 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 = %p", tp); + + if (!tp) { + return; + } + + 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; + } + 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, unsigned short af) +{ + int ret=0; + + DEBUG_CALL("tcp_fconnect"); + DEBUG_ARG("so = %p", so); + + ret = so->s = slirp_socket(af, SOCK_STREAM, 0); + if (ret >= 0) { + int opt, s=so->s; + struct sockaddr_storage addr; + + slirp_set_nonblock(s); + so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque); + slirp_socket_set_fast_reuse(s); + opt = 1; + setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(opt)); + opt = 1; + setsockopt(s, IPPROTO_TCP, TCP_NODELAY, &opt, sizeof(opt)); + + addr = so->fhost.ss; + DEBUG_CALL(" connect()ing"); + sotranslate_out(so, &addr); + + /* We don't care what port we get */ + ret = connect(s, (struct sockaddr *)&addr, sockaddr_size(&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_storage addr; + socklen_t addrlen = sizeof(struct sockaddr_storage); + struct tcpcb *tp; + int s, opt; + + DEBUG_CALL("tcp_connect"); + DEBUG_ARG("inso = %p", 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 (tcp_attach(so) < 0) { + g_free(so); /* NOT sofree */ + return; + } + so->lhost = inso->lhost; + so->so_ffamily = inso->so_ffamily; + } + + 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; + } + slirp_set_nonblock(s); + so->slirp->cb->register_poll_fd(so->s, so->slirp->opaque); + slirp_socket_set_fast_reuse(s); + opt = 1; + setsockopt(s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int)); + slirp_socket_set_nodelay(s); + + so->fhost.ss = addr; + sotranslate_accept(so); + + /* Close the accept() socket, set right state */ + if (inso->so_state & SS_FACCEPTONCE) { + /* If we only accept once, close the accept() socket */ + so->slirp->cb->unregister_poll_fd(so->s, so->slirp->opaque); + 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, 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; + unsigned n1, n2, n3, n4, n5, n6; + char buff[257]; + uint32_t laddr; + unsigned lport; + char *bptr; + + DEBUG_CALL("tcp_emu"); + DEBUG_ARG("so = %p", so); + DEBUG_ARG("m = %p", m); + + switch(so->so_emu) { + int x, i; + + /* TODO: IPv6 */ + 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; + + if (m->m_len > so_rcv->sb_datalen + - (so_rcv->sb_wptr - so_rcv->sb_data)) { + return 1; + } + + 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 = addr.sin_port; + break; + } + } + NTOHS(n1); + NTOHS(n2); + 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) { + uint16_t 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 = (((uint8_t*)bptr)[0] << 8) + + ((uint8_t *)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; + *(uint8_t *)bptr++ = (p >> 8) & 0xff; + *(uint8_t *)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 gfwd_list *ex_ptr; + + DEBUG_CALL("tcp_ctl"); + DEBUG_ARG("so = %p", so); + + /* TODO: IPv6 */ + if (so->so_faddr.s_addr != slirp->vhost_addr.s_addr) { + /* Check if it's pty_exec */ + for (ex_ptr = slirp->guestfwd_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->write_cb) { + so->s = -1; + so->guestfwd = ex_ptr; + return 1; + } + DEBUG_MISC(" executing %s", ex_ptr->ex_exec); + return fork_exec(so, ex_ptr->ex_exec); + } + } + } + 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; +} |