Archipelago » qemu

/*

 * 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.

 *

 *        @(#)udp_usrreq.c        8.4 (Berkeley) 1/21/94

 * udp_usrreq.c,v 1.4 1994/10/02 17:48:45 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>

#include "ip_icmp.h"

#ifdef LOG_ENABLED

struct udpstat udpstat;

#endif

struct socket udb;

static u_int8_t udp_tos(struct socket *so);

static void udp_emu(struct socket *so, struct mbuf *m);

/*

 * UDP protocol implementation.

 * Per RFC 768, August, 1980.

 */

#ifndef        COMPAT_42

#define UDPCKSUM 1

#else

#define UDPCKSUM 0 /* XXX */

#endif

struct        socket *udp_last_so = &udb;

void

udp_init(void)

{

        udb.so_next = udb.so_prev = &udb;

}

/* m->m_data  points at ip packet header

 * m->m_len   length ip packet

 * ip->ip_len length data (IPDU)

 */

void

udp_input(register struct mbuf *m, int iphlen)

{

        register struct ip *ip;

        register struct udphdr *uh;

/*        struct mbuf *opts = 0;*/

        int len;

        struct ip save_ip;

        struct socket *so;

        DEBUG_CALL("udp_input");

        DEBUG_ARG("m = %lx", (long)m);

        DEBUG_ARG("iphlen = %d", iphlen);

        STAT(udpstat.udps_ipackets++);

        /*

         * Strip IP options, if any; should skip this,

         * make available to user, and use on returned packets,

         * but we don't yet have a way to check the checksum

         * with options still present.

         */

        if(iphlen > sizeof(struct ip)) {

                ip_stripoptions(m, (struct mbuf *)0);

                iphlen = sizeof(struct ip);

        }

        /*

         * Get IP and UDP header together in first mbuf.

         */

        ip = mtod(m, struct ip *);

        uh = (struct udphdr *)((caddr_t)ip + iphlen);

        /*

         * Make mbuf data length reflect UDP length.

         * If not enough data to reflect UDP length, drop.

         */

        len = ntohs((u_int16_t)uh->uh_ulen);

        if (ip->ip_len != len) {

                if (len > ip->ip_len) {

                        STAT(udpstat.udps_badlen++);

                        goto bad;

                }

                m_adj(m, len - ip->ip_len);

                ip->ip_len = len;

        }

        /*

         * Save a copy of the IP header in case we want restore it

         * for sending an ICMP error message in response.

         */

        save_ip = *ip;

        save_ip.ip_len+= iphlen;         /* tcp_input subtracts this */

        /*

         * Checksum extended UDP header and data.

         */

        if (UDPCKSUM && uh->uh_sum) {

      memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr));

          ((struct ipovly *)ip)->ih_x1 = 0;

          ((struct ipovly *)ip)->ih_len = uh->uh_ulen;

          /* keep uh_sum for ICMP reply

           * uh->uh_sum = cksum(m, len + sizeof (struct ip));

           * if (uh->uh_sum) {

           */

          if(cksum(m, len + sizeof(struct ip))) {

            STAT(udpstat.udps_badsum++);

            goto bad;

          }

        }

        /*

         *  handle DHCP/BOOTP

         */

        if (ntohs(uh->uh_dport) == BOOTP_SERVER) {

            bootp_input(m);

            goto bad;

        }

        if (slirp_restrict)

            goto bad;

        /*

         *  handle TFTP

         */

        if (ntohs(uh->uh_dport) == TFTP_SERVER) {

            tftp_input(m);

            goto bad;

        }

        /*

         * Locate pcb for datagram.

         */

        so = udp_last_so;

        if (so->so_lport != uh->uh_sport ||

            so->so_laddr.s_addr != ip->ip_src.s_addr) {

                struct socket *tmp;

                for (tmp = udb.so_next; tmp != &udb; tmp = tmp->so_next) {

                        if (tmp->so_lport == uh->uh_sport &&

                            tmp->so_laddr.s_addr == ip->ip_src.s_addr) {

                                tmp->so_faddr.s_addr = ip->ip_dst.s_addr;

                                tmp->so_fport = uh->uh_dport;

                                so = tmp;

                                break;

                        }

                }

                if (tmp == &udb) {

                  so = NULL;

                } else {

                  STAT(udpstat.udpps_pcbcachemiss++);

                  udp_last_so = so;

                }

        }

        if (so == NULL) {

          /*

           * If there's no socket for this packet,

           * create one

           */

          if ((so = socreate()) == NULL) goto bad;

          if(udp_attach(so) == -1) {

            DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",

                        errno,strerror(errno)));

            sofree(so);

            goto bad;

          }

          /*

           * Setup fields

           */

          /* udp_last_so = so; */

          so->so_laddr = ip->ip_src;

          so->so_lport = uh->uh_sport;

          if ((so->so_iptos = udp_tos(so)) == 0)

            so->so_iptos = ip->ip_tos;

          /*

           * XXXXX Here, check if it's in udpexec_list,

           * and if it is, do the fork_exec() etc.

           */

        }

        so->so_faddr = ip->ip_dst; /* XXX */

        so->so_fport = uh->uh_dport; /* XXX */

        iphlen += sizeof(struct udphdr);

        m->m_len -= iphlen;

        m->m_data += iphlen;

        /*

         * Now we sendto() the packet.

         */

        if (so->so_emu)

           udp_emu(so, m);

        if(sosendto(so,m) == -1) {

          m->m_len += iphlen;

          m->m_data -= iphlen;

          *ip=save_ip;

          DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));

          icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));

        }

        m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */

        /* restore the orig mbuf packet */

        m->m_len += iphlen;

        m->m_data -= iphlen;

        *ip=save_ip;

        so->so_m=m;         /* ICMP backup */

        return;

bad:

        m_freem(m);

        /* if (opts) m_freem(opts); */

        return;

}

int udp_output2(struct socket *so, struct mbuf *m,

                struct sockaddr_in *saddr, struct sockaddr_in *daddr,

                int iptos)

{

        register struct udpiphdr *ui;

        int error = 0;

        DEBUG_CALL("udp_output");

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

        DEBUG_ARG("m = %lx", (long)m);

        DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);

        DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);

        /*

         * Adjust for header

         */

        m->m_data -= sizeof(struct udpiphdr);

        m->m_len += sizeof(struct udpiphdr);

        /*

         * Fill in mbuf with extended UDP header

         * and addresses and length put into network format.

         */

        ui = mtod(m, struct udpiphdr *);

    memset(&ui->ui_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));

        ui->ui_x1 = 0;

        ui->ui_pr = IPPROTO_UDP;

        ui->ui_len = htons(m->m_len - sizeof(struct ip)); /* + sizeof (struct udphdr)); */

        /* XXXXX Check for from-one-location sockets, or from-any-location sockets */

        ui->ui_src = saddr->sin_addr;

        ui->ui_dst = daddr->sin_addr;

        ui->ui_sport = saddr->sin_port;

        ui->ui_dport = daddr->sin_port;

        ui->ui_ulen = ui->ui_len;

        /*

         * Stuff checksum and output datagram.

         */

        ui->ui_sum = 0;

        if (UDPCKSUM) {

            if ((ui->ui_sum = cksum(m, /* sizeof (struct udpiphdr) + */ m->m_len)) == 0)

                ui->ui_sum = 0xffff;

        }

        ((struct ip *)ui)->ip_len = m->m_len;

        ((struct ip *)ui)->ip_ttl = IPDEFTTL;

        ((struct ip *)ui)->ip_tos = iptos;

        STAT(udpstat.udps_opackets++);

        error = ip_output(so, m);

        return (error);

}

int udp_output(struct socket *so, struct mbuf *m,

               struct sockaddr_in *addr)

{

    struct sockaddr_in saddr, daddr;

    saddr = *addr;

    if ((so->so_faddr.s_addr & htonl(0xffffff00)) == special_addr.s_addr) {

        if ((so->so_faddr.s_addr & htonl(0x000000ff)) == htonl(0xff))

            saddr.sin_addr.s_addr = alias_addr.s_addr;

        else if (addr->sin_addr.s_addr == loopback_addr.s_addr ||

                 (ntohl(so->so_faddr.s_addr) & 0xff) != CTL_ALIAS)

            saddr.sin_addr.s_addr = so->so_faddr.s_addr;

    }

    daddr.sin_addr = so->so_laddr;

    daddr.sin_port = so->so_lport;

    return udp_output2(so, m, &saddr, &daddr, so->so_iptos);

}

int

udp_attach(struct socket *so)

{

  struct sockaddr_in addr;

  if((so->s = socket(AF_INET,SOCK_DGRAM,0)) != -1) {

    /*

     * Here, we bind() the socket.  Although not really needed

     * (sendto() on an unbound socket will bind it), it's done

     * here so that emulation of ytalk etc. don't have to do it

     */

    addr.sin_family = AF_INET;

    addr.sin_port = 0;

    addr.sin_addr.s_addr = INADDR_ANY;

    if(bind(so->s, (struct sockaddr *)&addr, sizeof(addr))<0) {

      int lasterrno=errno;

      closesocket(so->s);

      so->s=-1;

#ifdef _WIN32

      WSASetLastError(lasterrno);

#else

      errno=lasterrno;

#endif

    } else {

      /* success, insert in queue */

      so->so_expire = curtime + SO_EXPIRE;

      insque(so,&udb);

    }

  }

  return(so->s);

}

void

udp_detach(struct socket *so)

{

        closesocket(so->s);

        /* if (so->so_m) m_free(so->so_m);    done by sofree */

        sofree(so);

}

static const struct tos_t udptos[] = {

        {0, 53, IPTOS_LOWDELAY, 0},                        /* DNS */

        {517, 517, IPTOS_LOWDELAY, EMU_TALK},        /* talk */

        {518, 518, IPTOS_LOWDELAY, EMU_NTALK},        /* ntalk */

        {0, 7648, IPTOS_LOWDELAY, EMU_CUSEEME},        /* Cu-Seeme */

        {0, 0, 0, 0}

};

static u_int8_t

udp_tos(struct socket *so)

{

        int i = 0;

        while(udptos[i].tos) {

                if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) ||

                    (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {

                            so->so_emu = udptos[i].emu;

                        return udptos[i].tos;

                }

                i++;

        }

        return 0;

}

#ifdef EMULATE_TALK

#include "talkd.h"

#endif

/*

 * Here, talk/ytalk/ntalk requests must be emulated

 */

static void

udp_emu(struct socket *so, struct mbuf *m)

{

        struct sockaddr_in addr;

        socklen_t addrlen = sizeof(addr);

#ifdef EMULATE_TALK

        CTL_MSG_OLD *omsg;

        CTL_MSG *nmsg;

        char buff[sizeof(CTL_MSG)];

        u_char type;

struct talk_request {

        struct talk_request *next;

        struct socket *udp_so;

        struct socket *tcp_so;

} *req;

        static struct talk_request *req_tbl = 0;

#endif

struct cu_header {

        uint16_t        d_family;                // destination family

        uint16_t        d_port;                        // destination port

        uint32_t        d_addr;                        // destination address

        uint16_t        s_family;                // source family

        uint16_t        s_port;                        // source port

        uint32_t        so_addr;                // source address

        uint32_t        seqn;                        // sequence number

        uint16_t        message;                // message

        uint16_t        data_type;                // data type

        uint16_t        pkt_len;                // packet length

} *cu_head;

        switch(so->so_emu) {

#ifdef EMULATE_TALK

         case EMU_TALK:

         case EMU_NTALK:

                /*

                 * Talk emulation. We always change the ctl_addr to get

                 * some answers from the daemon. When an ANNOUNCE comes,

                 * we send LEAVE_INVITE to the local daemons. Also when a

                 * DELETE comes, we send copies to the local daemons.

                 */

                if (getsockname(so->s, (struct sockaddr *)&addr, &addrlen) < 0)

                        return;

#define        IS_OLD        (so->so_emu == EMU_TALK)

#define COPY_MSG(dest, src) { dest->type = src->type; \

                              dest->id_num = src->id_num; \

                              dest->pid = src->pid; \

                              dest->addr = src->addr; \

                              dest->ctl_addr = src->ctl_addr; \

                              memcpy(&dest->l_name, &src->l_name, NAME_SIZE_OLD); \

                              memcpy(&dest->r_name, &src->r_name, NAME_SIZE_OLD); \

                               memcpy(&dest->r_tty, &src->r_tty, TTY_SIZE); }

#define OTOSIN(ptr, field) ((struct sockaddr_in *)&ptr->field)

/* old_sockaddr to sockaddr_in */

                if (IS_OLD) {                  /* old talk */

                        omsg = mtod(m, CTL_MSG_OLD*);

                        nmsg = (CTL_MSG *) buff;

                        type = omsg->type;

                        OTOSIN(omsg, ctl_addr)->sin_port = addr.sin_port;

                        OTOSIN(omsg, ctl_addr)->sin_addr = our_addr;

                        pstrcpy(omsg->l_name, NAME_SIZE_OLD, getlogin());

                } else {                /* new talk */

                        omsg = (CTL_MSG_OLD *) buff;

                        nmsg = mtod(m, CTL_MSG *);

                        type = nmsg->type;

                        OTOSIN(nmsg, ctl_addr)->sin_port = addr.sin_port;

                        OTOSIN(nmsg, ctl_addr)->sin_addr = our_addr;

                        pstrcpy(nmsg->l_name, NAME_SIZE_OLD, getlogin());

                }

                if (type == LOOK_UP)

                        return;                /* for LOOK_UP this is enough */

                if (IS_OLD) {                /* make a copy of the message */

                        COPY_MSG(nmsg, omsg);

                        nmsg->vers = 1;

                        nmsg->answer = 0;

                } else

                        COPY_MSG(omsg, nmsg);

                /*

                 * If if is an ANNOUNCE message, we go through the

                 * request table to see if a tcp port has already

                 * been redirected for this socket. If not, we solisten()

                 * a new socket and add this entry to the table.

                 * The port number of the tcp socket and our IP

                 * are put to the addr field of the message structures.

                 * Then a LEAVE_INVITE is sent to both local daemon

                 * ports, 517 and 518. This is why we have two copies

                 * of the message, one in old talk and one in new talk

                 * format.

                 */

                if (type == ANNOUNCE) {

                        int s;

                        u_short temp_port;

                        for(req = req_tbl; req; req = req->next)

                                if (so == req->udp_so)

                                        break;          /* found it */

                        if (!req) {        /* no entry for so, create new */

                                req = (struct talk_request *)

                                        malloc(sizeof(struct talk_request));

                                req->udp_so = so;

                                req->tcp_so = solisten(0,

                                        OTOSIN(omsg, addr)->sin_addr.s_addr,

                                        OTOSIN(omsg, addr)->sin_port,

                                        SS_FACCEPTONCE);

                                req->next = req_tbl;

                                req_tbl = req;

                        }

                        /* replace port number in addr field */

                        addrlen = sizeof(addr);

                        getsockname(req->tcp_so->s,

                                        (struct sockaddr *) &addr,

                                        &addrlen);

                        OTOSIN(omsg, addr)->sin_port = addr.sin_port;

                        OTOSIN(omsg, addr)->sin_addr = our_addr;

                        OTOSIN(nmsg, addr)->sin_port = addr.sin_port;

                        OTOSIN(nmsg, addr)->sin_addr = our_addr;

                        /* send LEAVE_INVITEs */

                        temp_port = OTOSIN(omsg, ctl_addr)->sin_port;

                        OTOSIN(omsg, ctl_addr)->sin_port = 0;

                        OTOSIN(nmsg, ctl_addr)->sin_port = 0;

                        omsg->type = nmsg->type = LEAVE_INVITE;

                        s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);

                        addr.sin_addr = our_addr;

                        addr.sin_family = AF_INET;

                        addr.sin_port = htons(517);

                        sendto(s, (char *)omsg, sizeof(*omsg), 0,

                                (struct sockaddr *)&addr, sizeof(addr));

                        addr.sin_port = htons(518);

                        sendto(s, (char *)nmsg, sizeof(*nmsg), 0,

                                (struct sockaddr *) &addr, sizeof(addr));

                        closesocket(s) ;

                        omsg->type = nmsg->type = ANNOUNCE;

                        OTOSIN(omsg, ctl_addr)->sin_port = temp_port;

                        OTOSIN(nmsg, ctl_addr)->sin_port = temp_port;

                }

                /*

                 * If it is a DELETE message, we send a copy to the

                 * local daemons. Then we delete the entry corresponding

                 * to our socket from the request table.

                 */

                if (type == DELETE) {

                        struct talk_request *temp_req, *req_next;

                        int s;

                        u_short temp_port;

                        temp_port = OTOSIN(omsg, ctl_addr)->sin_port;

                        OTOSIN(omsg, ctl_addr)->sin_port = 0;

                        OTOSIN(nmsg, ctl_addr)->sin_port = 0;

                        s = socket(AF_INET, SOCK_DGRAM, IPPROTO_IP);

                        addr.sin_addr = our_addr;

                        addr.sin_family = AF_INET;

                        addr.sin_port = htons(517);

                        sendto(s, (char *)omsg, sizeof(*omsg), 0,

                                (struct sockaddr *)&addr, sizeof(addr));

                        addr.sin_port = htons(518);

                        sendto(s, (char *)nmsg, sizeof(*nmsg), 0,

                                (struct sockaddr *)&addr, sizeof(addr));

                        closesocket(s);

                        OTOSIN(omsg, ctl_addr)->sin_port = temp_port;

                        OTOSIN(nmsg, ctl_addr)->sin_port = temp_port;

                        /* delete table entry */

                        if (so == req_tbl->udp_so) {

                                temp_req = req_tbl;

                                req_tbl = req_tbl->next;

                                free(temp_req);

                        } else {

                                temp_req = req_tbl;

                                for(req = req_tbl->next; req; req = req_next) {

                                        req_next = req->next;

                                        if (so == req->udp_so) {

                                                temp_req->next = req_next;

                                                free(req);

                                                break;

                                        } else {

                                                temp_req = req;

                                        }

                                }

                        }

                }

                return;

#endif

        case EMU_CUSEEME:

                /*

                 * Cu-SeeMe emulation.

                 * Hopefully the packet is more that 16 bytes long. We don't

                 * do any other tests, just replace the address and port

                 * fields.

                 */

                if (m->m_len >= sizeof (*cu_head)) {

                        if (getsockname(so->s, (struct sockaddr *)&addr, &addrlen) < 0)

                                return;

                        cu_head = mtod(m, struct cu_header *);

                        cu_head->s_port = addr.sin_port;

                        cu_head->so_addr = our_addr.s_addr;

                }

                return;

        }

}

struct socket *

udp_listen(u_int port, u_int32_t laddr, u_int lport, int flags)

{

        struct sockaddr_in addr;

        struct socket *so;

        socklen_t addrlen = sizeof(struct sockaddr_in), opt = 1;

        if ((so = socreate()) == NULL) {

                free(so);

                return NULL;

        }

        so->s = socket(AF_INET,SOCK_DGRAM,0);

        so->so_expire = curtime + SO_EXPIRE;

        insque(so,&udb);

        addr.sin_family = AF_INET;

        addr.sin_addr.s_addr = INADDR_ANY;

        addr.sin_port = port;

        if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {

                udp_detach(so);

                return NULL;

        }

        setsockopt(so->s,SOL_SOCKET,SO_REUSEADDR,(char *)&opt,sizeof(int));

/*        setsockopt(so->s,SOL_SOCKET,SO_OOBINLINE,(char *)&opt,sizeof(int)); */

        getsockname(so->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->so_lport = lport;

        so->so_laddr.s_addr = laddr;

        if (flags != SS_FACCEPTONCE)

           so->so_expire = 0;

        so->so_state = SS_ISFCONNECTED;

        return so;

}