/*
 * Copyright (c) 1995 Danny Gasparovski.
 * 
 * Please read the file COPYRIGHT for the 
 * terms and conditions of the copyright.
 */

#define WANT_SYS_IOCTL_H
#include <stdlib.h>
#include "slirp/slirp.h"
#include "slirp/ip_icmp.h"
#include "slirp/main.h"
#ifdef __sun__
#include <sys/filio.h>
#endif

#ifndef FIONREAD
#include <sys/ioctl.h>
#endif

void
so_init() {
	/* Nothing yet */
}

struct SLIRPsocket *
solookup(head, laddr, lport, faddr, fport)
	struct SLIRPsocket *head;
	struct in_addr laddr;
	u_int lport;
	struct in_addr faddr;
	u_int fport;
{
	struct SLIRPsocket *so;

	for (so = head->so_next; so != head; so = so->so_next) {
		if (so->so_lport == lport &&
			so->so_laddr.s_addr == laddr.s_addr &&
			so->so_faddr.s_addr == faddr.s_addr &&
			so->so_fport == fport)
			break;
	}

	if (so == head)
		return (struct SLIRPsocket *)NULL;
	return so;

}

/*
 * Create a new socket, initialise the fields
 * It is the responsibility of the caller to
 * insque() it into the correct linked-list
 */
struct SLIRPsocket *
socreate() {
	struct SLIRPsocket *so;

	so = (struct SLIRPsocket *)malloc(sizeof(struct SLIRPsocket));
	if (so) {
		memset(so, 0, sizeof(struct SLIRPsocket));
		so->so_state = SS_NOFDREF;
		so->s = -1;
	}
	return (so);
}

/*
 * remque and free a socket, clobber cache
 */
void
sofree(so)
	struct SLIRPsocket *so;
{
	if (so->so_emu == EMU_RSH && so->extra) {
		sofree(so->extra);
		so->extra = NULL;
	}
	if (so == tcp_last_so)
		tcp_last_so = &tcb;
	else if (so == udp_last_so)
		udp_last_so = &udb;

	if (so->so_m != NULL)
		m_free(so->so_m);

	if (so->so_next && so->so_prev)
		remque(so);  /* crashes if so is not in a queue */

	free(so);
}

/*
 * Read from so's socket into sb_snd, updating all relevant sbuf fields
 * NOTE: This will only be called if it is select()ed for reading, so
 * a read() of 0 (or less) means it's disconnected
 */
int
soread(so)
	struct SLIRPsocket *so;
{
	int n, nn, lss, total;
	struct sbuf *sb = &so->so_snd;
	int len = sb->sb_datalen - sb->sb_cc;
	struct iovec iov[2];
	int mss;
	if (!so->so_tcpcb)
		return 0;

	mss = so->so_tcpcb->t_maxseg;

	DEBUG_CALL("soread");
	DEBUG_ARG("so = %lx", (long)so);

	/* 
	 * No need to check if there's enough room to read.
	 * soread wouldn't have been called if there weren't
	 */

	len = sb->sb_datalen - sb->sb_cc;

	iov[0].iov_base = sb->sb_wptr;
	if (sb->sb_wptr < sb->sb_rptr) {
		iov[0].iov_len = sb->sb_rptr - sb->sb_wptr;
		/* Should never succeed, but... */
		if (iov[0].iov_len > len)
			iov[0].iov_len = len;
		if (iov[0].iov_len > mss)
			iov[0].iov_len -= iov[0].iov_len % mss;
		n = 1;
	} else {
		iov[0].iov_len = (sb->sb_data + sb->sb_datalen) - sb->sb_wptr;
		/* Should never succeed, but... */
		if (iov[0].iov_len > len)
			iov[0].iov_len = len;
		len -= iov[0].iov_len;
		if (len) {
			iov[1].iov_base = sb->sb_data;
			iov[1].iov_len = sb->sb_rptr - sb->sb_data;
			if (iov[1].iov_len > len)
				iov[1].iov_len = len;
			total = iov[0].iov_len + iov[1].iov_len;
			if (total > mss) {
				lss = total % mss;
				if (iov[1].iov_len > lss) {
					iov[1].iov_len -= lss;
					n = 2;
				} else {
					lss -= iov[1].iov_len;
					iov[0].iov_len -= lss;
					n = 1;
				}
			} else
				n = 2;
		} else {
			if (iov[0].iov_len > mss)
				iov[0].iov_len -= iov[0].iov_len % mss;
			n = 1;
		}
	}

#ifdef HAVE_READV
	nn = readv(so->s, (struct iovec *)iov, n);
	DEBUG_MISC((dfd, " ... read nn = %d bytes\n", nn));
#else
	nn = recv(so->s, iov[0].iov_base, iov[0].iov_len, 0);
#endif
	if (nn <= 0) {
		if (nn < 0 && (errno == EINTR || errno == EAGAIN))
			return 0;
		else {
			DEBUG_MISC((dfd, " --- soread() disconnected, nn = %d, errno = %d-%s\n", nn, errno, strerror(errno)));
			sofcantrcvmore(so);
			tcp_sockclosed(sototcpcb(so));
			return -1;
		}
	}

#ifndef HAVE_READV
	/*
	 * If there was no error, try and read the second time round
	 * We read again if n = 2 (ie, there's another part of the buffer)
	 * and we read as much as we could in the first read
	 * We don't test for <= 0 this time, because there legitimately
	 * might not be any more data (since the socket is non-blocking),
	 * a close will be detected on next iteration.
	 * A return of -1 wont (shouldn't) happen, since it didn't happen above
	 */
	if (n == 2 && nn == iov[0].iov_len) {
		int ret;
		ret = recv(so->s, iov[1].iov_base, iov[1].iov_len, 0);
		if (ret > 0)
			nn += ret;
	}

	DEBUG_MISC((dfd, " ... read nn = %d bytes\n", nn));
#endif

	/* Update fields */
	sb->sb_cc += nn;
	sb->sb_wptr += nn;
	if (sb->sb_wptr >= (sb->sb_data + sb->sb_datalen))
		sb->sb_wptr -= sb->sb_datalen;
	return nn;
}

/*
 * Get urgent data
 * 
 * When the socket is created, we set it SO_OOBINLINE,
 * so when OOB data arrives, we soread() it and everything
 * in the send buffer is sent as urgent data
 */
void
sorecvoob(so)
	struct SLIRPsocket *so;
{
	struct tcpcb *tp = sototcpcb(so);

	DEBUG_CALL("sorecvoob");
	DEBUG_ARG("so = %lx", (long)so);

	/*
	 * We take a guess at how much urgent data has arrived.
	 * In most situations, when urgent data arrives, the next
	 * read() should get all the urgent data.  This guess will
	 * be wrong however if more data arrives just after the
	 * urgent data, or the read() doesn't return all the 
	 * urgent data.
	 */
	soread(so);
	tp->snd_up = tp->snd_una + so->so_snd.sb_cc;
	tp->t_force = 1;
	tcp_output(tp);
	tp->t_force = 0;
}

/*
 * Send urgent data
 * There's a lot duplicated code here, but...
 */
int
sosendoob(so)
	struct SLIRPsocket *so;
{
	struct sbuf *sb = &so->so_rcv;
	char buff[2048]; /* XXX Shouldn't be sending more oob data than this */

	int n, len;

	DEBUG_CALL("sosendoob");
	DEBUG_ARG("so = %lx", (long)so);
	DEBUG_ARG("sb->sb_cc = %d", sb->sb_cc);

	if (so->so_urgc > 2048)
		so->so_urgc = 2048; /* XXXX */

	if (sb->sb_rptr < sb->sb_wptr) {
		/* We can send it directly */
		n = send(so->s, sb->sb_rptr, so->so_urgc, (MSG_OOB)); /* |MSG_DONTWAIT)); */
		so->so_urgc -= n;

		DEBUG_MISC((dfd, " --- sent %d bytes urgent data, %d urgent bytes left\n", n, so->so_urgc));
	} else {
		/* 
		 * Since there's no sendv or sendtov like writev,
		 * we must copy all data to a linear buffer then
		 * send it all
		 */
		len = (sb->sb_data + sb->sb_datalen) - sb->sb_rptr;
		if (len > so->so_urgc)
			len = so->so_urgc;
		memcpy(buff, sb->sb_rptr, len);
		so->so_urgc -= len;
		if (so->so_urgc) {
			n = sb->sb_wptr - sb->sb_data;
			if (n > so->so_urgc)
				n = so->so_urgc;
			memcpy((buff + len), sb->sb_data, n);
			so->so_urgc -= n;
			len += n;
		}
		n = send(so->s, buff, len, (MSG_OOB)); /* |MSG_DONTWAIT)); */
#ifdef SLIRP_DEBUG
		if (n != len)
		   DEBUG_ERROR((dfd, "Didn't send all data urgently XXXXX\n"));
#endif
		DEBUG_MISC((dfd, " ---2 sent %d bytes urgent data, %d urgent bytes left\n", n, so->so_urgc));
	}

	sb->sb_cc -= n;
	sb->sb_rptr += n;
	if (sb->sb_rptr >= (sb->sb_data + sb->sb_datalen))
		sb->sb_rptr -= sb->sb_datalen;

	return n;
}

/*
 * Write data from so_rcv to so's socket, 
 * updating all sbuf field as necessary
 */
int
sowrite(so)
	struct SLIRPsocket *so;
{
	int n, nn;
	struct sbuf *sb = &so->so_rcv;
	int len = sb->sb_cc;
	struct iovec iov[2];

	DEBUG_CALL("sowrite");
	DEBUG_ARG("so = %lx", (long)so);

	if (so->so_urgc) {
		sosendoob(so);
		if (sb->sb_cc == 0)
			return 0;
	}

	/*
	 * No need to check if there's something to write,
	 * sowrite wouldn't have been called otherwise
	 */

	len = sb->sb_cc;

	iov[0].iov_base = sb->sb_rptr;
	if (sb->sb_rptr < sb->sb_wptr) {
		iov[0].iov_len = sb->sb_wptr - sb->sb_rptr;
		/* Should never succeed, but... */
		if (iov[0].iov_len > len)
			iov[0].iov_len = len;
		n = 1;
	} else {
		iov[0].iov_len = (sb->sb_data + sb->sb_datalen) - sb->sb_rptr;
		if (iov[0].iov_len > len)
			iov[0].iov_len = len;
		len -= iov[0].iov_len;
		if (len) {
			iov[1].iov_base = sb->sb_data;
			iov[1].iov_len = sb->sb_wptr - sb->sb_data;
			if (iov[1].iov_len > len)
				iov[1].iov_len = len;
			n = 2;
		} else
			n = 1;
	}
	/* Check if there's urgent data to send, and if so, send it */

#ifdef HAVE_READV
	nn = writev(so->s, (const struct iovec *)iov, n);
	
	DEBUG_MISC((dfd, "  ... wrote nn = %d bytes\n", nn));
#else
	nn = send(so->s, iov[0].iov_base, iov[0].iov_len, 0);
#endif
	/* This should never happen, but people tell me it does *shrug* */
	if (nn < 0 && (errno == EAGAIN || errno == EINTR))
		return 0;

	if (nn <= 0) {
		DEBUG_MISC((dfd, " --- sowrite disconnected, so->so_state = %x, errno = %d\n",
			so->so_state, errno));
		sofcantsendmore(so);
		tcp_sockclosed(sototcpcb(so));
		return -1;
	}

#ifndef HAVE_READV
	if (n == 2 && nn == iov[0].iov_len) {
		int ret;
		ret = send(so->s, iov[1].iov_base, iov[1].iov_len, 0);
		if (ret > 0)
			nn += ret;
	}
	DEBUG_MISC((dfd, "  ... wrote nn = %d bytes\n", nn));
#endif

	/* Update sbuf */
	sb->sb_cc -= nn;
	sb->sb_rptr += nn;
	if (sb->sb_rptr >= (sb->sb_data + sb->sb_datalen))
		sb->sb_rptr -= sb->sb_datalen;

	/*
	 * If in DRAIN mode, and there's no more data, set
	 * it CANTSENDMORE
	 */
	if ((so->so_state & SS_FWDRAIN) && sb->sb_cc == 0)
		sofcantsendmore(so);

	return nn;
}

/*
 * recvfrom() a UDP socket
 */
void
sorecvfrom(so)
	struct SLIRPsocket *so;
{
	struct sockaddr_in addr;
	socklen_t addrlen = sizeof(struct sockaddr_in);

	DEBUG_CALL("sorecvfrom");
	DEBUG_ARG("so = %lx", (long)so);

	if (so->so_type == IPPROTO_ICMP) {   /* This is a "ping" reply */
		char buff[256];
		int len;

		len = recvfrom(so->s, buff, 256, 0,
			       (struct sockaddr *)&addr, &addrlen);
		/* XXX Check if reply is "correct"? */

		if (len == -1 || len == 0) {
			u_char code = ICMP_UNREACH_PORT;

			if (errno == EHOSTUNREACH)
				code = ICMP_UNREACH_HOST;
			else if (errno == ENETUNREACH)
				code = ICMP_UNREACH_NET;

			DEBUG_MISC((dfd, " udp icmp rx errno = %d-%s\n",
				errno, strerror(errno)));
			icmp_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno));
		} else {
			icmp_reflect(so->so_m);
			so->so_m = 0; /* Don't m_free() it again! */
		}
		/* No need for this socket anymore, udp_detach it */
		udp_detach(so);
	} else {                                /* A "normal" UDP packet */
		struct SLIRPmbuf *m;
		int len;
		ioctlsockopt_t n;

		if (!(m = m_get()))
			return;
		m->m_data += if_maxlinkhdr;

		/*
		 * XXX Shouldn't FIONREAD packets destined for port 53,
		 * but I don't know the max packet size for DNS lookups
		 */
		len = M_FREEROOM(m);
		/* if (so->so_fport != htons(53)) { */
		ioctlsocket(so->s, FIONREAD, &n);

		if (n > len) {
			n = (m->m_data - m->m_dat) + m->m_len + n + 1;
			m_inc(m, n);
			len = M_FREEROOM(m);
		}
		/* } */

		m->m_len = recvfrom(so->s, m->m_data, len, 0,
				    (struct sockaddr *)&addr, &addrlen);
		DEBUG_MISC((dfd, " did recvfrom %d, errno = %d-%s\n",
			m->m_len, errno, strerror(errno)));
		if (m->m_len < 0) {
			u_char code = ICMP_UNREACH_PORT;

			if (errno == EHOSTUNREACH)
				code = ICMP_UNREACH_HOST;
			else if (errno == ENETUNREACH)
				code = ICMP_UNREACH_NET;

			DEBUG_MISC((dfd, " rx error, tx icmp ICMP_UNREACH:%i\n", code));
			icmp_error(so->so_m, ICMP_UNREACH, code, 0, strerror(errno));
			m_free(m);
		} else {
			/*
			 * Hack: domain name lookup will be used the most for UDP,
			 * and since they'll only be used once there's no need
			 * for the 4 minute (or whatever) timeout... So we time them
			 * out much quicker (10 seconds  for now...)
			 */
			if (so->so_expire) {
				if (so->so_fport == htons(53))
					so->so_expire = curtime + SO_EXPIREFAST;
				else
					so->so_expire = curtime + SO_EXPIRE;
			}

			/*		if (m->m_len == len) {
			 *			m_inc(m, MINCSIZE);
			 *			m->m_len = 0;
			 *		}
			 */

			/*
			 * If this packet was destined for CTL_ADDR,
			 * make it look like that's where it came from, done by udp_output
			 */
			udp_output(so, m, &addr);
		} /* rx error */
	} /* if ping packet */
}

/*
 * sendto() a socket
 */
int
sosendto(so, m)
	struct SLIRPsocket *so;
	struct SLIRPmbuf *m;
{
	int ret;
	struct sockaddr_in addr;

	DEBUG_CALL("sosendto");
	DEBUG_ARG("so = %lx", (long)so);
	DEBUG_ARG("m = %lx", (long)m);

	addr.sin_family = AF_INET;
	if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {
		/* It's an alias */
		switch (ntohl(so->so_faddr.s_addr) & 0xff) {
		case CTL_DNS: addr.sin_addr = dns_addr;
			break;
		case CTL_ALIAS:
		default: addr.sin_addr = loopback_addr;
			break;
		}
	} else
		addr.sin_addr = so->so_faddr;
	addr.sin_port = so->so_fport;

	DEBUG_MISC((dfd, " sendto()ing, addr.sin_port=%d, addr.sin_addr.s_addr=%.16s\n", ntohs(addr.sin_port), inet_ntoa(addr.sin_addr)));

	/* Don't care what port we get */
	ret = sendto(so->s, m->m_data, m->m_len, 0,
		     (struct sockaddr *)&addr, sizeof(struct sockaddr));
	if (ret < 0)
		return -1;

	/*
	 * Kill the socket if there's no reply in 4 minutes,
	 * but only if it's an expirable socket
	 */
	if (so->so_expire)
		so->so_expire = curtime + SO_EXPIRE;
	so->so_state = SS_ISFCONNECTED; /* So that it gets select()ed */
	return 0;
}

/*
 * XXX This should really be tcp_listen
 */
struct SLIRPsocket *
solisten(port, laddr, lport, flags)
	u_int port;
	u_int32_t laddr;
	u_int lport;
	int flags;
{
	struct sockaddr_in addr;
	struct SLIRPsocket *so;
	int s;
	socklen_t addrlen = sizeof(addr);
	int opt = 1;

	DEBUG_CALL("solisten");
	DEBUG_ARG("port = %d", port);
	DEBUG_ARG("laddr = %x", laddr);
	DEBUG_ARG("lport = %d", lport);
	DEBUG_ARG("flags = %x", flags);

	if ((so = socreate()) == NULL) {
		/* free(so);      Not sofree() ??? free(NULL) == NOP */
		return NULL;
	}

	/* Don't tcp_attach... we don't need so_snd nor so_rcv */
	if ((so->so_tcpcb = tcp_newtcpcb(so)) == NULL) {
		free(so);
		return NULL;
	}
	insque(so, &tcb);

	/* 
	 * SS_FACCEPTONCE sockets must time out.
	 */
	if (flags & SS_FACCEPTONCE)
		so->so_tcpcb->t_timer[TCPT_KEEP] = TCPTV_KEEP_INIT * 2;

	so->so_state = (SS_FACCEPTCONN | flags);
	so->so_lport = lport; /* Kept in network format */
	so->so_laddr.s_addr = laddr; /* Ditto */

	memset(&addr, 0, sizeof(struct sockaddr_in));
	addr.sin_family = AF_INET;
	addr.sin_addr.s_addr = INADDR_ANY;
	addr.sin_port = port;

	if (((s = socket(AF_INET, SOCK_STREAM, 0)) < 0) ||
		(setsockopt(s, SOL_SOCKET, SO_REUSEADDR, (char *)&opt, sizeof(int)) < 0) ||
		(bind(s, (struct sockaddr *)&addr, sizeof(addr)) < 0) ||
		(listen(s, 1) < 0)) {
		int tmperrno = errno; /* Don't clobber the real reason we failed */

		close(s);
		sofree(so);
		/* Restore the real errno */
#ifdef _WIN32
		WSASetLastError(tmperrno);
#else
		errno = tmperrno;
#endif
		return NULL;
	}
	setsockopt(s, SOL_SOCKET, SO_OOBINLINE, (char *)&opt, sizeof(int));

	getsockname(s, (struct sockaddr *)&addr, &addrlen);
	so->so_fport = addr.sin_port;
	if (addr.sin_addr.s_addr == 0 || addr.sin_addr.s_addr == loopback_addr.s_addr)
		so->so_faddr = alias_addr;
	else
		so->so_faddr = addr.sin_addr;

	so->s = s;
	return so;
}

/* 
 * Data is available in so_rcv
 * Just write() the data to the socket
 * XXX not yet...
 */
void
sorwakeup(so)
	struct SLIRPsocket *so;
{
/*	sowrite(so); */
/*	FD_CLR(so->s,&writefds); */
}

/*
 * Data has been freed in so_snd
 * We have room for a read() if we want to
 * For now, don't read, it'll be done in the main loop
 */
void
sowwakeup(so)
	struct SLIRPsocket *so;
{
	/* Nothing, yet */
}

/*
 * Various session state calls
 * XXX Should be #define's
 * The socket state stuff needs work, these often get call 2 or 3
 * times each when only 1 was needed
 */
void
soisfconnecting(so)
	register struct SLIRPsocket *so;
{
	so->so_state &= ~(SS_NOFDREF | SS_ISFCONNECTED | SS_FCANTRCVMORE |
		SS_FCANTSENDMORE | SS_FWDRAIN);
	so->so_state |= SS_ISFCONNECTING; /* Clobber other states */
}

void
soisfconnected(so)
	register struct SLIRPsocket *so;
{
	so->so_state &= ~(SS_ISFCONNECTING | SS_FWDRAIN | SS_NOFDREF);
	so->so_state |= SS_ISFCONNECTED; /* Clobber other states */
}

void
sofcantrcvmore(so)
	struct SLIRPsocket *so;
{
	if ((so->so_state & SS_NOFDREF) == 0) {
		shutdown(so->s, 0);
		if (global_writefds) {
			FD_CLR(so->s, global_writefds);
		}
	}
	so->so_state &= ~(SS_ISFCONNECTING);
	if (so->so_state & SS_FCANTSENDMORE)
		so->so_state = SS_NOFDREF; /* Don't select it */ /* XXX close() here as well? */
	else
		so->so_state |= SS_FCANTRCVMORE;
}

void
sofcantsendmore(so)
	struct SLIRPsocket *so;
{
	if ((so->so_state & SS_NOFDREF) == 0) {
		shutdown(so->s, 1);           /* send FIN to fhost */
		if (global_readfds) {
			FD_CLR(so->s, global_readfds);
		}
		if (global_xfds) {
			FD_CLR(so->s, global_xfds);
		}
	}
	so->so_state &= ~(SS_ISFCONNECTING);
	if (so->so_state & SS_FCANTRCVMORE)
		so->so_state = SS_NOFDREF; /* as above */
	else
		so->so_state |= SS_FCANTSENDMORE;
}

void
soisfdisconnected(so)
	struct SLIRPsocket *so;
{
/*	so->so_state &= ~(SS_ISFCONNECTING|SS_ISFCONNECTED); */
/*	close(so->s); */
/*	so->so_state = SS_ISFDISCONNECTED; */
	/*
	 * XXX Do nothing ... ?
	 */
}

/*
 * Set write drain mode
 * Set CANTSENDMORE once all data has been write()n
 */
void
sofwdrain(so)
	struct SLIRPsocket *so;
{
	if (so->so_rcv.sb_cc)
		so->so_state |= SS_FWDRAIN;
	else
		sofcantsendmore(so);
}

