LXR qemu/slirp/udp.c

   1/*
   2 * Copyright (c) 1982, 1986, 1988, 1990, 1993
   3 *      The Regents of the University of California.  All rights reserved.
   4 *
   5 * Redistribution and use in source and binary forms, with or without
   6 * modification, are permitted provided that the following conditions
   7 * are met:
   8 * 1. Redistributions of source code must retain the above copyright
   9 *    notice, this list of conditions and the following disclaimer.
  10 * 2. Redistributions in binary form must reproduce the above copyright
  11 *    notice, this list of conditions and the following disclaimer in the
  12 *    documentation and/or other materials provided with the distribution.
  13 * 3. Neither the name of the University nor the names of its contributors
  14 *    may be used to endorse or promote products derived from this software
  15 *    without specific prior written permission.
  16 *
  17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27 * SUCH DAMAGE.
  28 *
  29 *      @(#)udp_usrreq.c        8.4 (Berkeley) 1/21/94
  30 * udp_usrreq.c,v 1.4 1994/10/02 17:48:45 phk Exp
  31 */
  32
  33/*
  34 * Changes and additions relating to SLiRP
  35 * Copyright (c) 1995 Danny Gasparovski.
  36 *
  37 * Please read the file COPYRIGHT for the
  38 * terms and conditions of the copyright.
  39 */
  40
  41#include "qemu/osdep.h"
  42#include "slirp.h"
  43#include "ip_icmp.h"
  44
  45static uint8_t udp_tos(struct socket *so);
  46
  47void
  48udp_init(Slirp *slirp)
  49{
  50    slirp->udb.so_next = slirp->udb.so_prev = &slirp->udb;
  51    slirp->udp_last_so = &slirp->udb;
  52}
  53
  54void udp_cleanup(Slirp *slirp)
  55{
  56    while (slirp->udb.so_next != &slirp->udb) {
  57        udp_detach(slirp->udb.so_next);
  58    }
  59}
  60
  61/* m->m_data  points at ip packet header
  62 * m->m_len   length ip packet
  63 * ip->ip_len length data (IPDU)
  64 */
  65void
  66udp_input(register struct mbuf *m, int iphlen)
  67{
  68        Slirp *slirp = m->slirp;
  69        register struct ip *ip;
  70        register struct udphdr *uh;
  71        int len;
  72        struct ip save_ip;
  73        struct socket *so;
  74        struct sockaddr_storage lhost;
  75        struct sockaddr_in *lhost4;
  76
  77        DEBUG_CALL("udp_input");
  78        DEBUG_ARG("m = %p", m);
  79        DEBUG_ARG("iphlen = %d", iphlen);
  80
  81        /*
  82         * Strip IP options, if any; should skip this,
  83         * make available to user, and use on returned packets,
  84         * but we don't yet have a way to check the checksum
  85         * with options still present.
  86         */
  87        if(iphlen > sizeof(struct ip)) {
  88                ip_stripoptions(m, (struct mbuf *)0);
  89                iphlen = sizeof(struct ip);
  90        }
  91
  92        /*
  93         * Get IP and UDP header together in first mbuf.
  94         */
  95        ip = mtod(m, struct ip *);
  96        uh = (struct udphdr *)((caddr_t)ip + iphlen);
  97
  98        /*
  99         * Make mbuf data length reflect UDP length.
 100         * If not enough data to reflect UDP length, drop.
 101         */
 102        len = ntohs((uint16_t)uh->uh_ulen);
 103
 104        if (ip->ip_len != len) {
 105                if (len > ip->ip_len) {
 106                        goto bad;
 107                }
 108                m_adj(m, len - ip->ip_len);
 109                ip->ip_len = len;
 110        }
 111
 112        /*
 113         * Save a copy of the IP header in case we want restore it
 114         * for sending an ICMP error message in response.
 115         */
 116        save_ip = *ip;
 117        save_ip.ip_len+= iphlen;         /* tcp_input subtracts this */
 118
 119        /*
 120         * Checksum extended UDP header and data.
 121         */
 122        if (uh->uh_sum) {
 123      memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr));
 124          ((struct ipovly *)ip)->ih_x1 = 0;
 125          ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 126          if(cksum(m, len + sizeof(struct ip))) {
 127            goto bad;
 128          }
 129        }
 130
 131        lhost.ss_family = AF_INET;
 132        lhost4 = (struct sockaddr_in *) &lhost;
 133        lhost4->sin_addr = ip->ip_src;
 134        lhost4->sin_port = uh->uh_sport;
 135
 136        /*
 137         *  handle DHCP/BOOTP
 138         */
 139        if (ntohs(uh->uh_dport) == BOOTP_SERVER &&
 140            (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr ||
 141             ip->ip_dst.s_addr == 0xffffffff)) {
 142                bootp_input(m);
 143                goto bad;
 144            }
 145
 146        /*
 147         *  handle TFTP
 148         */
 149        if (ntohs(uh->uh_dport) == TFTP_SERVER &&
 150            ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
 151            m->m_data += iphlen;
 152            m->m_len -= iphlen;
 153            tftp_input(&lhost, m);
 154            m->m_data -= iphlen;
 155            m->m_len += iphlen;
 156            goto bad;
 157        }
 158
 159        if (slirp->restricted) {
 160            goto bad;
 161        }
 162
 163        /*
 164         * Locate pcb for datagram.
 165         */
 166        so = solookup(&slirp->udp_last_so, &slirp->udb, &lhost, NULL);
 167
 168        if (so == NULL) {
 169          /*
 170           * If there's no socket for this packet,
 171           * create one
 172           */
 173          so = socreate(slirp);
 174          if (!so) {
 175              goto bad;
 176          }
 177          if (udp_attach(so, AF_INET) == -1) {
 178            DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",
 179                        errno,strerror(errno)));
 180            sofree(so);
 181            goto bad;
 182          }
 183
 184          /*
 185           * Setup fields
 186           */
 187          so->so_lfamily = AF_INET;
 188          so->so_laddr = ip->ip_src;
 189          so->so_lport = uh->uh_sport;
 190
 191          if ((so->so_iptos = udp_tos(so)) == 0)
 192            so->so_iptos = ip->ip_tos;
 193
 194          /*
 195           * XXXXX Here, check if it's in udpexec_list,
 196           * and if it is, do the fork_exec() etc.
 197           */
 198        }
 199
 200        so->so_ffamily = AF_INET;
 201        so->so_faddr = ip->ip_dst; /* XXX */
 202        so->so_fport = uh->uh_dport; /* XXX */
 203
 204        iphlen += sizeof(struct udphdr);
 205        m->m_len -= iphlen;
 206        m->m_data += iphlen;
 207
 208        /*
 209         * Now we sendto() the packet.
 210         */
 211        if(sosendto(so,m) == -1) {
 212          m->m_len += iphlen;
 213          m->m_data -= iphlen;
 214          *ip=save_ip;
 215          DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
 216          icmp_send_error(m, ICMP_UNREACH, ICMP_UNREACH_NET, 0,
 217                          strerror(errno));
 218          goto bad;
 219        }
 220
 221        m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */
 222
 223        /* restore the orig mbuf packet */
 224        m->m_len += iphlen;
 225        m->m_data -= iphlen;
 226        *ip=save_ip;
 227        so->so_m=m;         /* ICMP backup */
 228
 229        return;
 230bad:
 231        m_free(m);
 232}
 233
 234int udp_output(struct socket *so, struct mbuf *m,
 235                struct sockaddr_in *saddr, struct sockaddr_in *daddr,
 236                int iptos)
 237{
 238        register struct udpiphdr *ui;
 239        int error = 0;
 240
 241        DEBUG_CALL("udp_output");
 242        DEBUG_ARG("so = %p", so);
 243        DEBUG_ARG("m = %p", m);
 244        DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
 245        DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);
 246
 247        /*
 248         * Adjust for header
 249         */
 250        m->m_data -= sizeof(struct udpiphdr);
 251        m->m_len += sizeof(struct udpiphdr);
 252
 253        /*
 254         * Fill in mbuf with extended UDP header
 255         * and addresses and length put into network format.
 256         */
 257        ui = mtod(m, struct udpiphdr *);
 258    memset(&ui->ui_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
 259        ui->ui_x1 = 0;
 260        ui->ui_pr = IPPROTO_UDP;
 261        ui->ui_len = htons(m->m_len - sizeof(struct ip));
 262        /* XXXXX Check for from-one-location sockets, or from-any-location sockets */
 263        ui->ui_src = saddr->sin_addr;
 264        ui->ui_dst = daddr->sin_addr;
 265        ui->ui_sport = saddr->sin_port;
 266        ui->ui_dport = daddr->sin_port;
 267        ui->ui_ulen = ui->ui_len;
 268
 269        /*
 270         * Stuff checksum and output datagram.
 271         */
 272        ui->ui_sum = 0;
 273        if ((ui->ui_sum = cksum(m, m->m_len)) == 0)
 274                ui->ui_sum = 0xffff;
 275        ((struct ip *)ui)->ip_len = m->m_len;
 276
 277        ((struct ip *)ui)->ip_ttl = IPDEFTTL;
 278        ((struct ip *)ui)->ip_tos = iptos;
 279
 280        error = ip_output(so, m);
 281
 282        return (error);
 283}
 284
 285int
 286udp_attach(struct socket *so, unsigned short af)
 287{
 288  so->s = qemu_socket(af, SOCK_DGRAM, 0);
 289  if (so->s != -1) {
 290    so->so_expire = curtime + SO_EXPIRE;
 291    insque(so, &so->slirp->udb);
 292  }
 293  return(so->s);
 294}
 295
 296void
 297udp_detach(struct socket *so)
 298{
 299        closesocket(so->s);
 300        sofree(so);
 301}
 302
 303static const struct tos_t udptos[] = {
 304        {0, 53, IPTOS_LOWDELAY, 0},                     /* DNS */
 305        {0, 0, 0, 0}
 306};
 307
 308static uint8_t
 309udp_tos(struct socket *so)
 310{
 311        int i = 0;
 312
 313        while(udptos[i].tos) {
 314                if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) ||
 315                    (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {
 316                        so->so_emu = udptos[i].emu;
 317                        return udptos[i].tos;
 318                }
 319                i++;
 320        }
 321
 322        return 0;
 323}
 324
 325struct socket *
 326udp_listen(Slirp *slirp, uint32_t haddr, u_int hport, uint32_t laddr,
 327           u_int lport, int flags)
 328{
 329        struct sockaddr_in addr;
 330        struct socket *so;
 331        socklen_t addrlen = sizeof(struct sockaddr_in);
 332
 333        so = socreate(slirp);
 334        if (!so) {
 335            return NULL;
 336        }
 337        so->s = qemu_socket(AF_INET,SOCK_DGRAM,0);
 338        so->so_expire = curtime + SO_EXPIRE;
 339        insque(so, &slirp->udb);
 340
 341        addr.sin_family = AF_INET;
 342        addr.sin_addr.s_addr = haddr;
 343        addr.sin_port = hport;
 344
 345        if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {
 346                udp_detach(so);
 347                return NULL;
 348        }
 349        socket_set_fast_reuse(so->s);
 350
 351        getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
 352        so->fhost.sin = addr;
 353        sotranslate_accept(so);
 354        so->so_lfamily = AF_INET;
 355        so->so_lport = lport;
 356        so->so_laddr.s_addr = laddr;
 357        if (flags != SS_FACCEPTONCE)
 358           so->so_expire = 0;
 359
 360        so->so_state &= SS_PERSISTENT_MASK;
 361        so->so_state |= SS_ISFCONNECTED | flags;
 362
 363        return so;
 364}
 365