/*
 * 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 */

                closesocket(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);
}
