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

#include "qemu/osdep.h"
#include "slirp.h"
#include "libslirp.h"
#include "qemu/error-report.h"
#include "qemu/main-loop.h"

#ifdef DEBUG
int slirp_debug = DBG_CALL|DBG_MISC|DBG_ERROR;
#endif

inline void
insque(void *a, void *b)
{
	register struct quehead *element = (struct quehead *) a;
	register struct quehead *head = (struct quehead *) b;
	element->qh_link = head->qh_link;
	head->qh_link = (struct quehead *)element;
	element->qh_rlink = (struct quehead *)head;
	((struct quehead *)(element->qh_link))->qh_rlink
	= (struct quehead *)element;
}

inline void
remque(void *a)
{
  register struct quehead *element = (struct quehead *) a;
  ((struct quehead *)(element->qh_link))->qh_rlink = element->qh_rlink;
  ((struct quehead *)(element->qh_rlink))->qh_link = element->qh_link;
  element->qh_rlink = NULL;
}

int add_exec(struct ex_list **ex_ptr, void *chardev, const char *cmdline,
             struct in_addr addr, int port)
{
	struct ex_list *tmp_ptr;

	/* First, check if the port is "bound" */
	for (tmp_ptr = *ex_ptr; tmp_ptr; tmp_ptr = tmp_ptr->ex_next) {
		if (port == tmp_ptr->ex_fport &&
		    addr.s_addr == tmp_ptr->ex_addr.s_addr)
			return -1;
	}

	tmp_ptr = *ex_ptr;
	*ex_ptr = g_new0(struct ex_list, 1);
	(*ex_ptr)->ex_fport = port;
	(*ex_ptr)->ex_addr = addr;
	if (chardev) {
		(*ex_ptr)->ex_chardev = chardev;
	} else {
		(*ex_ptr)->ex_exec = g_strdup(cmdline);
	}
	(*ex_ptr)->ex_next = tmp_ptr;
	return 0;
}


#ifdef _WIN32

int
fork_exec(struct socket *so, const char *ex)
{
    /* not implemented */
    return 0;
}

#else

static int
slirp_socketpair_with_oob(int sv[2])
{
    struct sockaddr_in addr = {
        .sin_family = AF_INET,
        .sin_port = 0,
        .sin_addr.s_addr = INADDR_ANY,
    };
    socklen_t addrlen = sizeof(addr);
    int ret, s;

    sv[1] = -1;
    s = qemu_socket(AF_INET, SOCK_STREAM, 0);
    if (s < 0 || bind(s, (struct sockaddr *)&addr, addrlen) < 0 ||
        listen(s, 1) < 0 ||
        getsockname(s, (struct sockaddr *)&addr, &addrlen) < 0) {
        goto err;
    }

    sv[1] = qemu_socket(AF_INET, SOCK_STREAM, 0);
    if (sv[1] < 0) {
        goto err;
    }
    /*
     * This connect won't block because we've already listen()ed on
     * the server end (even though we won't accept() the connection
     * until later on).
     */
    do {
        ret = connect(sv[1], (struct sockaddr *)&addr, addrlen);
    } while (ret < 0 && errno == EINTR);
    if (ret < 0) {
        goto err;
    }

    do {
        sv[0] = accept(s, (struct sockaddr *)&addr, &addrlen);
    } while (sv[0] < 0 && errno == EINTR);
    if (sv[0] < 0) {
        goto err;
    }

    closesocket(s);
    return 0;

err:
    error_report("Error: slirp_socketpair(): %s", strerror(errno));
    if (s >= 0) {
        closesocket(s);
    }
    if (sv[1] >= 0) {
        closesocket(sv[1]);
    }
    return -1;
}

int
fork_exec(struct socket *so, const char *ex)
{
	char **argv;
	int opt, c, sp[2];
	pid_t pid;

	DEBUG_CALL("fork_exec");
	DEBUG_ARG("so = %p", so);
	DEBUG_ARG("ex = %p", ex);

    if (slirp_socketpair_with_oob(sp) < 0) {
        return 0;
    }

	pid = fork();
	switch(pid) {
	 case -1:
		error_report("Error: fork failed: %s", strerror(errno));
		closesocket(sp[0]);
		closesocket(sp[1]);
		return 0;

	 case 0:
		setsid();
		dup2(sp[1], 0);
		dup2(sp[1], 1);
		dup2(sp[1], 2);
		for (c = getdtablesize() - 1; c >= 3; c--)
		   close(c);

                argv = g_strsplit(ex, " ", -1);
		execvp(argv[0], (char **)argv);

		/* Ooops, failed, let's tell the user why */
        fprintf(stderr, "Error: execvp of %s failed: %s\n",
                argv[0], strerror(errno));
		close(0); close(1); close(2); /* XXX */
		exit(1);

	 default:
		so->s = sp[0];
		closesocket(sp[1]);
		qemu_add_child_watch(pid);
		socket_set_fast_reuse(so->s);
		opt = 1;
		qemu_setsockopt(so->s, SOL_SOCKET, SO_OOBINLINE, &opt, sizeof(int));
		qemu_set_nonblock(so->s);
		return 1;
	}
}
#endif

char *slirp_connection_info(Slirp *slirp)
{
    GString *str = g_string_new(NULL);
    const char * const tcpstates[] = {
        [TCPS_CLOSED]       = "CLOSED",
        [TCPS_LISTEN]       = "LISTEN",
        [TCPS_SYN_SENT]     = "SYN_SENT",
        [TCPS_SYN_RECEIVED] = "SYN_RCVD",
        [TCPS_ESTABLISHED]  = "ESTABLISHED",
        [TCPS_CLOSE_WAIT]   = "CLOSE_WAIT",
        [TCPS_FIN_WAIT_1]   = "FIN_WAIT_1",
        [TCPS_CLOSING]      = "CLOSING",
        [TCPS_LAST_ACK]     = "LAST_ACK",
        [TCPS_FIN_WAIT_2]   = "FIN_WAIT_2",
        [TCPS_TIME_WAIT]    = "TIME_WAIT",
    };
    struct in_addr dst_addr;
    struct sockaddr_in src;
    socklen_t src_len;
    uint16_t dst_port;
    struct socket *so;
    const char *state;
    char buf[20];

    g_string_append_printf(str,
        "  Protocol[State]    FD  Source Address  Port   "
        "Dest. Address  Port RecvQ SendQ\n");

    for (so = slirp->tcb.so_next; so != &slirp->tcb; so = so->so_next) {
        if (so->so_state & SS_HOSTFWD) {
            state = "HOST_FORWARD";
        } else if (so->so_tcpcb) {
            state = tcpstates[so->so_tcpcb->t_state];
        } else {
            state = "NONE";
        }
        if (so->so_state & (SS_HOSTFWD | SS_INCOMING)) {
            src_len = sizeof(src);
            getsockname(so->s, (struct sockaddr *)&src, &src_len);
            dst_addr = so->so_laddr;
            dst_port = so->so_lport;
        } else {
            src.sin_addr = so->so_laddr;
            src.sin_port = so->so_lport;
            dst_addr = so->so_faddr;
            dst_port = so->so_fport;
        }
        snprintf(buf, sizeof(buf), "  TCP[%s]", state);
        g_string_append_printf(str, "%-19s %3d %15s %5d ", buf, so->s,
                       src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
                       ntohs(src.sin_port));
        g_string_append_printf(str, "%15s %5d %5d %5d\n",
                       inet_ntoa(dst_addr), ntohs(dst_port),
                       so->so_rcv.sb_cc, so->so_snd.sb_cc);
    }

    for (so = slirp->udb.so_next; so != &slirp->udb; so = so->so_next) {
        if (so->so_state & SS_HOSTFWD) {
            snprintf(buf, sizeof(buf), "  UDP[HOST_FORWARD]");
            src_len = sizeof(src);
            getsockname(so->s, (struct sockaddr *)&src, &src_len);
            dst_addr = so->so_laddr;
            dst_port = so->so_lport;
        } else {
            snprintf(buf, sizeof(buf), "  UDP[%d sec]",
                         (so->so_expire - curtime) / 1000);
            src.sin_addr = so->so_laddr;
            src.sin_port = so->so_lport;
            dst_addr = so->so_faddr;
            dst_port = so->so_fport;
        }
        g_string_append_printf(str, "%-19s %3d %15s %5d ", buf, so->s,
                       src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*",
                       ntohs(src.sin_port));
        g_string_append_printf(str, "%15s %5d %5d %5d\n",
                       inet_ntoa(dst_addr), ntohs(dst_port),
                       so->so_rcv.sb_cc, so->so_snd.sb_cc);
    }

    for (so = slirp->icmp.so_next; so != &slirp->icmp; so = so->so_next) {
        snprintf(buf, sizeof(buf), "  ICMP[%d sec]",
                     (so->so_expire - curtime) / 1000);
        src.sin_addr = so->so_laddr;
        dst_addr = so->so_faddr;
        g_string_append_printf(str, "%-19s %3d %15s  -    ", buf, so->s,
                       src.sin_addr.s_addr ? inet_ntoa(src.sin_addr) : "*");
        g_string_append_printf(str, "%15s  -    %5d %5d\n", inet_ntoa(dst_addr),
                       so->so_rcv.sb_cc, so->so_snd.sb_cc);
    }

    return g_string_free(str, FALSE);
}