kegs-android/jni/scc_socket_driver.c

/************************************************************************/
/*			KEGS: Apple //gs Emulator			*/
/*			Copyright 2002-2004 by Kent Dickey		*/
/*									*/
/*		This code is covered by the GNU GPL			*/
/*									*/
/*	The KEGS web page is kegs.sourceforge.net			*/
/*	You may contact the author at: kadickey@alumni.princeton.edu	*/
/************************************************************************/

const char rcsid_scc_socket_driver_c[] = "@(#)$KmKId: scc_socket_driver.c,v 1.11 2004-12-06 19:42:09-05 kentd Exp $";

/* This file contains the socket calls */

#include "defc.h"
#include "scc.h"
#include <signal.h>

extern Scc scc_stat[2];
extern int g_serial_modem[];

extern int h_errno;
int g_wsastartup_called = 0;

/* Usage: scc_socket_init() called to init socket mode */
/*  At all times, we try to have a listen running on the incoming socket */
/* If we want to dial out, we close the incoming socket and create a new */
/*  outgoing socket.  Any hang-up causes the socket to be closed and it will */
/*  then re-open on a subsequent call to scc_socket_open */

void
scc_socket_init(int port)
{
	Scc	*scc_ptr;

#ifdef _WIN32
	WSADATA	wsadata;
	int	ret;

	if(g_wsastartup_called == 0) {
		ret = WSAStartup(MAKEWORD(2,0), &wsadata);
		printf("WSAStartup ret: %d\n", ret);
		g_wsastartup_called = 1;
	}
#endif
	scc_ptr = &(scc_stat[port]);
	scc_ptr->state = 1;		/* successful socket */
	scc_ptr->sockfd = -1;		/* Indicate no socket open yet */
	scc_ptr->accfd = -1;		/* Indicate no socket open yet */
	scc_ptr->rdwrfd = -1;		/* Indicate no socket open yet */
	scc_ptr->socket_state = -2;	/* 0 means talk to "modem" */
					/* 1 connected */
	scc_ptr->socket_num_rings = 0;
	scc_ptr->socket_last_ring_dcycs = 0;
	scc_ptr->dcd = 0;		/* 0 means no carrier */
	scc_ptr->modem_s0_val = 0;
	scc_ptr->host_aux1 = sizeof(struct sockaddr_in);
	scc_ptr->host_handle = malloc(scc_ptr->host_aux1);
	/* Real init will be done when bytes need to be read/write from skt */
}

void
scc_socket_maybe_open_incoming(int port, double dcycs)
{
	Scc	*scc_ptr;
	struct sockaddr_in sa_in;
	int	on;
	int	ret;
	SOCKET	sockfd;
	int	inc;

	inc = 0;

	scc_ptr = &(scc_stat[port]);

	if(scc_ptr->sockfd != -1) {
		/* it's already open, get out */
		return;
	}
	if(scc_ptr->socket_state < 0) {
		/* not initialized, get out */
		return;
	}

	printf("scc socket close being called from socket_open_out\n");
	scc_socket_close(port, 0, dcycs);

	scc_ptr->socket_state = 0;
	scc_ptr->socket_num_rings = 0;

	memset(scc_ptr->host_handle, 0, scc_ptr->host_aux1);

	while(1) {
		sockfd = socket(AF_INET, SOCK_STREAM, 0);
		printf("sockfd ret: %d\n", sockfd);
		if(sockfd == -1) {
			printf("socket ret: %d, errno: %d\n", sockfd, errno);
			scc_socket_close(port, 0, dcycs);
			scc_ptr->socket_state = -1;
			return;
		}
		/* printf("socket ret: %d\n", sockfd); */

		on = 1;
		ret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
					(char *)&on, sizeof(on));
		if(ret < 0) {
			printf("setsockopt REUSEADDR ret: %d, err:%d\n",
				ret, errno);
			scc_socket_close(port, 0, dcycs);
			scc_ptr->socket_state = -1;
			return;
		}

		memset(&sa_in, 0, sizeof(sa_in));
		sa_in.sin_family = AF_INET;
		sa_in.sin_port = htons(6501 + port + inc);
		sa_in.sin_addr.s_addr = htonl(INADDR_ANY);

		ret = bind(sockfd, (struct sockaddr *)&sa_in, sizeof(sa_in));

		if(ret >= 0) {
			ret = listen(sockfd, 1);
			break;
		}
		/* else ret to bind was < 0 */
		printf("bind ret: %d, errno: %d\n", ret, errno);
		inc++;
		close(sockfd);
		printf("Trying next port: %d\n", 6501 + port + inc);
		if(inc >= 10) {
			printf("Too many retries, quitting\n");
			scc_socket_close(port, 0, dcycs);
			scc_ptr->socket_state = -1;
			return;
		}
	}

	printf("SCC port %d is at unix port %d\n", port, 6501 + port + inc);

	scc_ptr->sockfd = sockfd;
	scc_ptr->state = 1;		/* successful socket */

	scc_socket_make_nonblock(port, dcycs);

}

void
scc_socket_open_outgoing(int port, double dcycs)
{
	Scc	*scc_ptr;
	struct sockaddr_in sa_in;
	struct hostent *hostentptr;
	int	on;
	int	ret;
	SOCKET	sockfd;

	scc_ptr = &(scc_stat[port]);

	printf("scc socket close being called from socket_open_out\n");
	scc_socket_close(port, 0, dcycs);

	scc_ptr->socket_state = 0;

	memset(scc_ptr->host_handle, 0, scc_ptr->host_aux1);

	sockfd = socket(AF_INET, SOCK_STREAM, 0);
	printf("sockfd ret: %d\n", sockfd);
	if(sockfd == -1) {
		printf("socket ret: %d, errno: %d\n", sockfd, errno);
		scc_socket_close(port, 1, dcycs);
		return;
	}
	/* printf("socket ret: %d\n", sockfd); */

	on = 1;
	ret = setsockopt(sockfd, SOL_SOCKET, SO_REUSEADDR,
					(char *)&on, sizeof(on));
	if(ret < 0) {
		printf("setsockopt REUSEADDR ret: %d, err:%d\n",
			ret, errno);
		scc_socket_close(port, 1, dcycs);
		return;
	}

	memset(&sa_in, 0, sizeof(sa_in));
	sa_in.sin_family = AF_INET;
	sa_in.sin_port = htons(23);
	hostentptr = gethostbyname(&scc_ptr->modem_cmd_str[0]);
	if(hostentptr == 0) {
#ifdef _WIN32
		fatal_printf("Lookup host %s failed\n",
						&scc_ptr->modem_cmd_str[0]);
#else
		fatal_printf("Lookup host %s failed, herrno: %d\n",
					&scc_ptr->modem_cmd_str[0], h_errno);
#endif
		close(sockfd);
		scc_socket_close(port, 1, dcycs);
		x_show_alert(0, 0);
		return;
	}
	memcpy(&sa_in.sin_addr.s_addr, hostentptr->h_addr,
							hostentptr->h_length);
	/* The above copies the 32-bit internet address into */
	/*   sin_addr.s_addr.  It's in correct network format */

	ret = connect(sockfd, (struct sockaddr *)&sa_in, sizeof(sa_in));
	if(ret < 0) {
		printf("connect ret: %d, errno: %d\n", ret, errno);
		close(sockfd);
		scc_socket_close(port, 1, dcycs);
		return;
	}
	scc_socket_modem_connect(port, dcycs);
	scc_ptr->dcd = 1;		/* carrier on */
	scc_ptr->socket_state = 1;	/* talk to socket */
	scc_ptr->socket_num_rings = 0;

	printf("SCC port %d is now outgoing to %s\n", port,
						&scc_ptr->modem_cmd_str[0]);

	scc_ptr->sockfd = sockfd;
	scc_ptr->state = 1;		/* successful socket */

	scc_socket_make_nonblock(port, dcycs);
	scc_ptr->rdwrfd = scc_ptr->sockfd;
}

void
scc_socket_make_nonblock(int port, double dcycs)
{
	Scc	*scc_ptr;
	SOCKET	sockfd;
	int	ret;
#ifdef _WIN32
	u_long	flags;
#else
	int	flags;
#endif

	scc_ptr = &(scc_stat[port]);
	sockfd = scc_ptr->sockfd;

#ifdef _WIN32
	flags = 1;
	ret = ioctlsocket(sockfd, FIONBIO, &flags);
	if(ret != 0) {
		printf("ioctlsocket ret: %d\n", ret);
	}
#else
	flags = fcntl(sockfd, F_GETFL, 0);
	if(flags == -1) {
		printf("fcntl GETFL ret: %d, errno: %d\n", flags, errno);
		scc_socket_close(port, 1, dcycs);
		scc_ptr->socket_state = -1;
		return;
	}
	ret = fcntl(sockfd, F_SETFL, flags | O_NONBLOCK);
	if(ret == -1) {
		printf("fcntl SETFL ret: %d, errno: %d\n", ret, errno);
		scc_socket_close(port, 1, dcycs);
		scc_ptr->socket_state = -1;
		return;
	}
#endif
}

void
scc_socket_change_params(int port)
{
}

void
scc_socket_close(int port, int full_close, double dcycs)
{
	Scc	*scc_ptr;
	int	rdwrfd;
	SOCKET	sockfd;
	int	i;

	scc_ptr = &(scc_stat[port]);

	printf("In scc_socket_close, %d, %d, %f\n", port, full_close, dcycs);

	rdwrfd = scc_ptr->rdwrfd;
	if(rdwrfd >= 0) {
		printf("socket_close: rdwrfd=%d, closing\n", rdwrfd);
		close(rdwrfd);
	}
	sockfd = scc_ptr->sockfd;
	if(sockfd != -1) {
		printf("socket_close: sockfd=%d, closing\n", sockfd);
		close(sockfd);
	}

	scc_ptr->modem_cmd_len = 0;
	scc_ptr->telnet_mode = 0;
	scc_ptr->telnet_iac = 0;
	for(i = 0; i < 2; i++) {
		scc_ptr->telnet_local_mode[i] = 0;
		scc_ptr->telnet_remote_mode[i] = 0;
		scc_ptr->telnet_reqwill_mode[i] = 0;
		scc_ptr->telnet_reqdo_mode[i] = 0;
	}
	scc_ptr->rdwrfd = -1;
	scc_ptr->sockfd = -1;
	scc_ptr->dcd = 0;
	scc_ptr->socket_num_rings = 0;

	if(!full_close) {
		return;
	}

	scc_socket_modem_hangup(port, dcycs);

	/* and go back to modem mode */
	scc_ptr->socket_state = 0;
	if(g_serial_modem[port]) {
		scc_ptr->modem_dial_or_acc_mode = 0;
	} else {
		scc_ptr->modem_dial_or_acc_mode = 2;	/* always accept */
	}
}

void
scc_accept_socket(int port, double dcycs)
{
#ifdef SCC_SOCKETS
	Scc	*scc_ptr;
	int	flags;
	int	num_rings;
	int	rdwrfd;
	int	ret;

	scc_ptr = &(scc_stat[port]);

	if(scc_ptr->sockfd == -1) {
		printf("in accept_socket, call socket_open\n");
		scc_socket_maybe_open_incoming(port, dcycs);
	}
	if(scc_ptr->sockfd == -1) {
		return;		/* just give up */
	}
	if(scc_ptr->rdwrfd == -1) {
		rdwrfd = accept(scc_ptr->sockfd, scc_ptr->host_handle,
						&(scc_ptr->host_aux1));
		if(rdwrfd < 0) {
			return;
		}

		flags = 0;
		ret = 0;
#ifndef _WIN32
		/* For Linux, we need to set O_NONBLOCK on the rdwrfd */
		flags = fcntl(rdwrfd, F_GETFL, 0);
		if(flags == -1) {
			printf("fcntl GETFL ret: %d, errno: %d\n", flags,errno);
			return;
		}
		ret = fcntl(rdwrfd, F_SETFL, flags | O_NONBLOCK);
		if(ret == -1) {
			printf("fcntl SETFL ret: %d, errno: %d\n", ret, errno);
			return;
		}
#endif
		scc_ptr->rdwrfd = rdwrfd;
		printf("Set port[%d].rdwrfd = %d\n", port, rdwrfd);

		num_rings = 4;
		if(scc_ptr->modem_s0_val > 0) {
			num_rings = scc_ptr->modem_s0_val;
		}
		scc_ptr->socket_num_rings = num_rings;
		scc_ptr->socket_last_ring_dcycs = 0;	/* do ring now*/
		scc_socket_modem_do_ring(port, dcycs);

		/* and send some telnet codes */
		scc_ptr->telnet_reqwill_mode[0] = 0xa;	/* 3=GO_AH and 1=ECHO */
		scc_ptr->telnet_reqdo_mode[0] = 0xa;	/* 3=GO_AH and 1=ECHO */
#if 0
		scc_ptr->telnet_reqdo_mode[1] = 0x4;	/* 34=LINEMODE */
#endif
	}
#endif
}

void
scc_socket_telnet_reqs(int port, double dcycs)
{
	Scc	*scc_ptr;
	word32	mask, willmask, domask;
	int	i, j;

	scc_ptr = &(scc_stat[port]);
	
	for(i = 0; i < 64; i++) {
		j = i >> 5;
		mask = 1 << (i & 31);
		willmask = scc_ptr->telnet_reqwill_mode[j];
		if(willmask & mask) {
			scc_add_to_writebuf(port, 0xff, dcycs);
			scc_add_to_writebuf(port, 0xfb, dcycs);	/* WILL */
			scc_add_to_writebuf(port, i, dcycs);
		}
		domask = scc_ptr->telnet_reqdo_mode[j];
		if(domask & mask) {
			scc_add_to_writebuf(port, 0xff, dcycs);
			scc_add_to_writebuf(port, 0xfd, dcycs);	/* DO */
			scc_add_to_writebuf(port, i, dcycs);
		}
	}
}

void
scc_socket_fill_readbuf(int port, int space_left, double dcycs)
{
#ifdef SCC_SOCKETS
	byte	tmp_buf[256];
	Scc	*scc_ptr;
	int	rdwrfd;
	int	ret;
	int	i;

	scc_ptr = &(scc_stat[port]);

	scc_accept_socket(port, dcycs);
	scc_socket_modem_do_ring(port, dcycs);

	if(scc_ptr->socket_state == 0 && g_serial_modem[port]) {
		/* Just get out, this is modem mode */
		/*  The transmit function stuffs any bytes in receive buf */
		return;
	}
	rdwrfd = scc_ptr->rdwrfd;
	if(rdwrfd < 0) {
		return;		/* just get out */
	}

	/* Try reading some bytes */
	space_left = MIN(space_left, 256);
	ret = recv(rdwrfd, tmp_buf, space_left, 0);
	if(ret > 0) {
		for(i = 0; i < ret; i++) {
			if(tmp_buf[i] == 0) {
				/* Skip null chars */
				continue;
			}
			scc_socket_recvd_char(port, tmp_buf[i], dcycs);
		}
	} else if(ret == 0) {
		/* assume socket close */
		printf("recv got 0 from rdwrfd=%d, closing\n", rdwrfd);
		scc_socket_close(port, 1, dcycs);
	}
#endif
}

int g_scc_dbg_print_cnt = 50;

void
scc_socket_recvd_char(int port, int c, double dcycs)
{
	Scc	*scc_ptr;
	word32	locmask, remmask, mask;
	word32	reqwillmask, reqdomask;
	int	telnet_mode, telnet_iac;
	int	eff_c, cpos;
	int	reply;

	scc_ptr = &(scc_stat[port]);

	scc_socket_maybe_open_incoming(port, dcycs);

	telnet_mode = scc_ptr->telnet_mode;
	telnet_iac = scc_ptr->telnet_iac;
	if(c >= 0xf0 || telnet_mode || telnet_iac) {
		g_scc_dbg_print_cnt = 50;
	}
#if 0
	if(g_scc_dbg_print_cnt) {
		printf("Recv: %02x mode: %d\n", c, telnet_mode);
		g_scc_dbg_print_cnt--;
	}
#endif

	eff_c = c;
	if(telnet_iac == 0) {
		if(c == 0xff) {
			scc_ptr->telnet_iac = 0xff;
			return;			/* and just get out */
		}
	} else {
		/* last char was 0xff, see if this is 0xff */
		if(c != 0xff) {
			/* this is some kind of command */
			eff_c = eff_c | 0x100;	/* indicate prev char IAC */
		}
	}
	scc_ptr->telnet_iac = 0;

	mask = 1 << (c & 31);
	cpos = (c >> 5) & 1;
	locmask = scc_ptr->telnet_local_mode[cpos] & mask;
	remmask = scc_ptr->telnet_remote_mode[cpos] & mask;
	reqwillmask = scc_ptr->telnet_reqwill_mode[cpos] & mask;
	reqdomask = scc_ptr->telnet_reqdo_mode[cpos] & mask;
	switch(telnet_mode) {
	case 0:	/* just passing through bytes */
		switch(eff_c) {
		case 0x1fe:	/* DON'T */
		case 0x1fd:	/* DO */
		case 0x1fc:	/* WON'T */
		case 0x1fb:	/* WILL */
		case 0x1fa:	/* SB */
			telnet_mode = c;
			break;
		default:
			if(eff_c < 0x100) {
				scc_add_to_readbuf(port, c, dcycs);
			}
			break;
		}
		break;
	case 3: /* LINEMODE SB SLC, octet 0 */
		if(eff_c == 0x1f0) {
			/* SE, the end */
			telnet_mode = 0;
		}
		printf("LINEMODE SLC octet 0: %02x\n", c);
		telnet_mode = 4;
		break;
	case 4: /* LINEMODE SB SLC, octet 1 */
		printf("LINEMODE SLC octet 1: %02x\n", c);
		telnet_mode = 5;
		if(eff_c == 0x1f0) {
			/* SE, the end */
			printf("Got SE at octet 1...\n");
			telnet_mode = 0;
		}
		break;
	case 5: /* LINEMODE SB SLC, octet 2 */
		printf("LINEMODE SLC octet 2: %02x\n", c);
		telnet_mode = 3;
		if(eff_c == 0x1f0) {
			/* SE, the end */
			printf("Got SE at octet 2...\n");
			telnet_mode = 0;
		}
		break;
	case 34: /* LINEMODE SB beginning */
		switch(c) {
		case 3:	/* SLC */
			telnet_mode = 3;
			break;
		default:
			telnet_mode = 0xee;	/* go to SB eat */
			break;
		}
		break;
	case 0xfa: /* in 0xfa = SB mode, eat up subcommands */
		switch(c) {
		case 34:	/* LINEMODE */
			telnet_mode = 34;
			break;
		default:
			telnet_mode = 0xee;	/* SB eat mode */
			break;
		}
		break;
	case 0xee: /* in SB eat mode */
		if(eff_c == 0x1f0) {		/* SE, end of sub-command */
			telnet_mode = 0;
		} else {
			/* just stay in eat mode */
		}
		break;
	case 0xfe:	/* previous char was "DON'T" */
		if(locmask && (reqwillmask == 0)) {
			/* it's a mode change */
			/* always OK to turn off a mode that we had on */
			scc_add_to_writebuf(port, 0xff, dcycs);
			scc_add_to_writebuf(port, 0xfc, dcycs);	/* WON'T */
			scc_add_to_writebuf(port, c, dcycs);
		}
		scc_ptr->telnet_local_mode[cpos] &= ~mask;
		scc_ptr->telnet_reqwill_mode[cpos] &= ~mask;
		telnet_mode = 0;
		break;
	case 0xfd:	/* previous char was "DO" */
		reply = 0xfc;
		if(locmask == 0 && (reqwillmask == 0)) {
			/* it's a mode change, send some response  */
			reply = 0xfc;	/* nack it with WON'T */
			if(c == 0x03 || c == 0x01) {
				reply = 0xfb;	/* Ack with WILL */
			}
			scc_add_to_writebuf(port, 0xff, dcycs);
			scc_add_to_writebuf(port, reply, dcycs);
			scc_add_to_writebuf(port, c, dcycs);
		}
		if(reqwillmask || (reply == 0xfb)) {
			scc_ptr->telnet_local_mode[cpos] |= mask;
		}
		scc_ptr->telnet_reqwill_mode[cpos] &= ~mask;
		telnet_mode = 0;
		break;
	case 0xfc:	/* previous char was "WON'T" */
		if(remmask && (reqdomask == 0)) {
			/* it's a mode change, ack with DON'T */
			scc_add_to_writebuf(port, 0xff, dcycs);
			scc_add_to_writebuf(port, 0xfe, dcycs);	/* DON'T */
			scc_add_to_writebuf(port, c, dcycs);
		}
		scc_ptr->telnet_remote_mode[cpos] &= ~mask;
		scc_ptr->telnet_reqdo_mode[cpos] &= ~mask;
		telnet_mode = 0;
		break;
	case 0xfb:	/* previous char was "WILL" */
		reply = 0xfe;	/* nack it with DON'T */
		if(remmask == 0 && (reqdomask == 0)) {
			/* it's a mode change, send some response  */
			if(c == 0x03 || c == 0x01) {
				reply = 0xfd;	/* Ack with DO */
			}
			scc_add_to_writebuf(port, 0xff, dcycs);
			scc_add_to_writebuf(port, reply, dcycs);
			scc_add_to_writebuf(port, c, dcycs);
		}
		if(reqdomask || (reply == 0xfd)) {
			scc_ptr->telnet_remote_mode[cpos] |= mask;
		}
		scc_ptr->telnet_reqdo_mode[cpos] &= ~mask;
		telnet_mode = 0;
		break;
	default:
		telnet_mode = 0;
		break;
	}
	scc_ptr->telnet_mode = telnet_mode;
}

void
scc_socket_empty_writebuf(int port, double dcycs)
{
#ifdef SCC_SOCKETS
# ifndef _WIN32
	struct sigaction newact, oldact;
# endif
	Scc	*scc_ptr;
	double	diff_dcycs;
	int	plus_mode;
	int	rdptr;
	int	wrptr;
	int	rdwrfd;
	int	done;
	int	ret;
	int	len;
	int	c;
	int	i;

	scc_ptr = &(scc_stat[port]);

	/* See if +++ done and we should go to command mode */
	diff_dcycs = dcycs - scc_ptr->out_char_dcycs;
	if((diff_dcycs > 900.0*1000) && (scc_ptr->modem_plus_mode == 3) &&
				(scc_ptr->socket_state >= 1) &&
				(g_serial_modem[port] != 0)) {
		scc_ptr->socket_state = 0;	/* go modem mode, stay connect*/
		scc_ptr->modem_plus_mode = 0;
		scc_socket_send_modem_code(port, 0, dcycs);
	}

	/* Try writing some bytes */
	done = 0;
	while(!done) {
		rdptr = scc_ptr->out_rdptr;
		wrptr = scc_ptr->out_wrptr;
		if(rdptr == wrptr) {
			done = 1;
			break;
		}
		rdwrfd = scc_ptr->rdwrfd;
		len = wrptr - rdptr;
		if(len < 0) {
			len = SCC_OUTBUF_SIZE - rdptr;
		}
		if(len > 32) {
			len = 32;
		}
		if(len <= 0) {
			done = 1;
			break;
		}

		if(scc_ptr->socket_state < 1 && g_serial_modem[port]) {
			len = 1;
			scc_socket_modem_write(port, scc_ptr->out_buf[rdptr],
								dcycs);
			ret = 1;
		} else {
			if(rdwrfd == -1) {
				if(g_serial_modem[port]) {
					printf("socket_state: %d, ser_mod: %d, "
						"rdwrfd: %d\n",
						scc_ptr->socket_state,
						g_serial_modem[port], rdwrfd);
				}
				scc_ptr->socket_state = 0;
				scc_socket_maybe_open_incoming(port, dcycs);
				return;
			}
			for(i = 0; i < len; i++) {
				c = scc_ptr->out_buf[rdptr + i];
				plus_mode = scc_ptr->modem_plus_mode;
				diff_dcycs = dcycs - scc_ptr->out_char_dcycs;
				if(c == '+' && plus_mode == 0) {
					if(diff_dcycs > 500*1000) {
						scc_ptr->modem_plus_mode = 1;
					}
				} else if(c == '+') {
					if(diff_dcycs < 800.0*1000) {
						plus_mode++;
						scc_ptr->modem_plus_mode =
								plus_mode;
					}
				} else {
					scc_ptr->modem_plus_mode = 0;
				}
				scc_ptr->out_char_dcycs = dcycs;
			}

# ifdef _WIN32
			ret = send(rdwrfd, &(scc_ptr->out_buf[rdptr]), len, 0);
# else
			/* ignore SIGPIPE around writes to the socket, so we */
			/*  can catch a closed socket and prepare to accept */
			/*  a new connection.  Otherwise, SIGPIPE kills KEGS */
			sigemptyset(&newact.sa_mask);
			newact.sa_handler = SIG_IGN;
			newact.sa_flags = 0;
			sigaction(SIGPIPE, &newact, &oldact);

			ret = send(rdwrfd, &(scc_ptr->out_buf[rdptr]), len, 0);

			sigaction(SIGPIPE, &oldact, 0);
			/* restore previous SIGPIPE behavior */
# endif	/* WIN32 */

#if 0
			printf("sock output: %02x\n", scc_ptr->out_buf[rdptr]);
#endif

		}

		if(ret == 0) {
			done = 1;	/* give up for now */
			break;
		} else if(ret < 0) {
			/* assume socket is dead */
			printf("socket write failed, resuming modem mode\n");
			scc_socket_close(port, 1, dcycs);
			done = 1;
			break;
		} else {
			rdptr = rdptr + ret;
			if(rdptr >= SCC_OUTBUF_SIZE) {
				rdptr = rdptr - SCC_OUTBUF_SIZE;
			}
			scc_ptr->out_rdptr = rdptr;
		}
	}
#endif
}

void
scc_socket_modem_write(int port, int c, double dcycs)
{
	Scc	*scc_ptr;
	char	*str;
	word32	modem_mode;
	int	do_echo;
	int	got_at;
	int	len;

	scc_ptr = &(scc_stat[port]);

	if(scc_ptr->sockfd == -1) {
		scc_ptr->socket_state = 0;
		scc_socket_maybe_open_incoming(port, dcycs);
	}

	modem_mode = scc_ptr->modem_mode;
	str = &(scc_ptr->modem_cmd_str[0]);

#if 0
	printf("M: %02x\n", c);
#endif
	do_echo = ((modem_mode & SCCMODEM_NOECHO) == 0);
	len = scc_ptr->modem_cmd_len;
	got_at = 0;
	if(len >= 2 && str[0] == 'a' && str[1] == 't') {
		/* we've got an 'at', do not back up past it */
		got_at = 1;
	}
	if(c == 0x0d) {
		if(do_echo) {
			scc_add_to_readbuf(port, c, dcycs);	/* echo cr */
			scc_add_to_readbuf(port, 0x0a, dcycs);	/* echo lf */
		}
		do_echo = 0;	/* already did the echo */
		scc_socket_do_cmd_str(port, dcycs);
		scc_ptr->modem_cmd_len = 0;
		len = 0;
		str[0] = 0;
	} else if(c == 0x08) {
		if(len <= 0) {
			do_echo = 0;	/* do not go past left margin */
		} else if(len == 2 && got_at) {
			do_echo = 0;	/* do not erase "AT" */
		} else {
			/* erase a character */
			len--;
			str[len] = 0;
		}
	} else if(c < 0x20) {
		/* ignore all control characters, don't echo */
		/* includes line feeds and nulls */
		do_echo = 0;
	} else {
		/* other characters */
		if(len < SCC_MODEM_MAX_CMD_STR) {
			str[len] = tolower(c);
			str[len+1] = 0;
			len++;
		}
	}
	scc_ptr->modem_cmd_len = len;
	if(do_echo) {
		scc_add_to_readbuf(port, c, dcycs);	/* echo */
	}
}

void
scc_socket_do_cmd_str(int port, double dcycs)
{
	Scc	*scc_ptr;
	char	*str;
	int	pos, len;
	int	ret_val;
	int	reg, reg_val;
	int	was_amp;
	int	c;
	int	i;

	scc_ptr = &(scc_stat[port]);

	str = &(scc_ptr->modem_cmd_str[0]);
	printf("Got modem string :%s:=%02x %02x %02x\n", str, str[0], str[1],
						str[2]);

	len = scc_ptr->modem_cmd_len;
	str[len] = 0;
	str[len+1] = 0;
	str[len+2] = 0;
	pos = -1;
	if(len < 2) {
		/* just ignore it */
		return;
	}
	if(str[0] != 'a' || str[1] != 't') {
		return;
	}

	/* Some AT command received--make sure socket 6501/6502 is open */
	printf("Some AT command received, sockfd=%d\n", scc_ptr->sockfd);

	pos = 2 - 1;
	ret_val = 0;		/* "OK" */
	was_amp = 0;
	while(++pos < len) {
		c = str[pos] + was_amp;
		was_amp = 0;
		switch(c) {
		case '&':	/* at& */
			was_amp = 0x100;
			break;
		case 'z':	/* atz */
			scc_ptr->modem_mode = 0;
			scc_ptr->modem_s0_val = 0;
			pos = len;		/* ignore any other commands */
			break;
		case 'e':	/* ate = echo */
			c = str[pos+1];
			if(c == '1') {
				scc_ptr->modem_mode &= ~SCCMODEM_NOECHO;
				pos++;
			} else {
				scc_ptr->modem_mode |= SCCMODEM_NOECHO;
				pos++;
			}
			break;
		case 'v':	/* atv = verbose */
			c = str[pos+1];
			if(c == '1') {
				scc_ptr->modem_mode &= ~SCCMODEM_NOVERBOSE;
				pos++;
			} else {
				scc_ptr->modem_mode |= SCCMODEM_NOVERBOSE;
				pos++;
			}
			break;
		case 'o':	/* ato = go online */
			printf("ato\n");
			if(scc_ptr->dcd && (scc_ptr->rdwrfd != -1) &&
						(scc_ptr->socket_state == 0)) {
				printf("Going back online\n");
				scc_ptr->socket_state = 1;
				scc_socket_modem_connect(port, dcycs);
				ret_val = -1;
			}
			break;
		case 'h':	/* ath = hang up */
			printf("ath, hanging up\n");
			scc_socket_close(port, (scc_ptr->rdwrfd != -1), dcycs);
			/* scc_socket_maybe_open_incoming(port, dcycs); */
							/* reopen listen */
			break;
		case 'a':	/* ata */
			printf("Doing ATA\n");
			scc_socket_do_answer(port, dcycs);
			ret_val = -1;
			break;
		case 'd':	/* atd */
			pos++;
			c = str[pos];
			if(c == 't' || c == 'p') {
				/* skip tone or pulse */
				pos++;
			}
			/* see if it is 111 */
			if(strcmp(&str[pos], "111") == 0) {
				/* Do PPP! */
			} else {
				/* get string to connect to */
				/* Shift string so hostname moves to str[0] */
				for(i = 0; i < len; i++) {
					str[i] = str[pos];
					if(pos >= len) {
						break;
					}
					pos++;
				}
				
			}
			scc_ptr->modem_dial_or_acc_mode = 1;
			scc_socket_open_outgoing(port, dcycs);
			ret_val = -1;
			pos = len;	/* always eat rest of the line */
			break;
		case 's':	/* atsnn=yy */
			pos++;
			reg = 0;
			while(1) {
				c = str[pos];
				if(c < '0' || c > '9') {
					break;
				}
				reg = (reg * 10) + c - '0';
				pos++;
			}
			if(c == '?') {
				/* display S-register */
				if(reg == 0) {
					scc_add_to_readbufv(port, dcycs,
						"S0=%d\n",
						scc_ptr->modem_s0_val);
				}
				break;
			}
			if(c != '=') {
				break;
			}
			pos++;
			reg_val = 0;
			while(1) {
				c = str[pos];
				if(c < '0' || c >'9') {
					break;
				}
				reg_val = (reg_val * 10) + c - '0';
				pos++;
			}
			printf("ats%d = %d\n", reg, reg_val);
			if(reg == 0) {
				scc_ptr->modem_s0_val = reg_val;
			}
			pos--;
			break;
		default:
			/* some command--peek into next chars to finish it */
			while(1) {
				c = str[pos+1];
				if(c >= '0' && c <= '9') {
					/* eat numbers */
					pos++;
					continue;
				}
				if(c == '=') {
					/* eat this as well */
					pos++;
					continue;
				}
				/* else get out */
				break;
			}
		}
	}

	if(ret_val >= 0) {
		scc_socket_send_modem_code(port, ret_val, dcycs);
	}
}

void
scc_socket_send_modem_code(int port, int code, double dcycs)
{
	Scc	*scc_ptr;
	char	*str;
	word32	modem_mode;

	scc_ptr = &(scc_stat[port]);

	switch(code) {
	case 0: str = "OK"; break;
	case 1: str = "CONNECT"; break;
	case 2: str = "RING"; break;
	case 3: str = "NO CARRIER"; break;
	case 4: str = "ERROR"; break;
	case 5: str = "CONNECT 1200"; break;
	case 13: str = "CONNECT 9600"; break;
	case 16: str = "CONNECT 19200"; break;
	case 25: str = "CONNECT 14400"; break;
	case 85: str = "CONNECT 19200"; break;
	default:
		str = "ERROR";
	}

	printf("Sending modem code %d = %s\n", code, str);

	modem_mode = scc_ptr->modem_mode;
	if(modem_mode & SCCMODEM_NOVERBOSE) {
		/* just the number */
		scc_add_to_readbufv(port, dcycs, "%d", code);
		scc_add_to_readbuf(port, 0x0d, dcycs);
	} else {
		scc_add_to_readbufv(port, dcycs, "%s\n", str);
	}
}

void
scc_socket_modem_hangup(int port, double dcycs)
{
	scc_socket_send_modem_code(port, 3, dcycs);
}

void
scc_socket_modem_connect(int port, double dcycs)
{
	/* decide which code to send.  Default to 1 if needed */
	scc_socket_send_modem_code(port, 13, dcycs);	/*13=9600*/
}

void
scc_socket_modem_do_ring(int port, double dcycs)
{
	Scc	*scc_ptr;
	double	diff_dcycs;
	int	num_rings;

	scc_ptr = &(scc_stat[port]);
	num_rings = scc_ptr->socket_num_rings;
	if(num_rings > 0 && scc_ptr->socket_state == 0) {
		num_rings--;
		diff_dcycs = dcycs - scc_ptr->socket_last_ring_dcycs;
		if(diff_dcycs < 2.0*1000*1000 && g_serial_modem[port]) {
			return;		/* nothing more to do */
		}
		printf("In modem_do_ring, ringing at %f\n", dcycs);
		if(g_serial_modem[port]) {
			scc_socket_send_modem_code(port, 2, dcycs); /* RING */
		} else {
			num_rings = 0;
		}
		scc_ptr->socket_num_rings = num_rings;
		scc_ptr->socket_last_ring_dcycs = dcycs;
		if(num_rings <= 0) {
			/* decide on answering */
			if(scc_ptr->modem_s0_val || (g_serial_modem[port]==0)) {
				scc_socket_do_answer(port, dcycs);
			} else {
				printf("No answer, closing socket\n");
				scc_socket_close(port, 0, dcycs);
			}
		}
	}
}

void
scc_socket_do_answer(int port, double dcycs)
{
	Scc	*scc_ptr;

	scc_ptr = &(scc_stat[port]);
	scc_ptr->modem_dial_or_acc_mode = 2;
	scc_accept_socket(port, dcycs);
	if(scc_ptr->rdwrfd == -1) {
		printf("Answer when rdwrfd=-1, closing\n");
		scc_socket_close(port, 1, dcycs);
		/* send NO CARRIER message */
	} else {
		scc_ptr->socket_state = 1;
		scc_socket_telnet_reqs(port, dcycs);
		printf("Send telnet reqs, rdwrfd=%d\n", scc_ptr->rdwrfd);
		if(g_serial_modem[port]) {
			scc_socket_modem_connect(port, dcycs);
		}
		scc_ptr->dcd = 1;		/* carrier on */
		scc_ptr->socket_state = 1; /* talk to socket */
		scc_ptr->socket_num_rings = 0;
	}
}