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 <slirp.h>
  42#include "ip_icmp.h"
  43
  44static uint8_t udp_tos(struct socket *so);
  45
  46void
  47udp_init(Slirp *slirp)
  48{
  49    slirp->udb.so_next = slirp->udb.so_prev = &slirp->udb;
  50    slirp->udp_last_so = &slirp->udb;
  51}
  52
  53void udp_cleanup(Slirp *slirp)
  54{
  55    while (slirp->udb.so_next != &slirp->udb) {
  56        udp_detach(slirp->udb.so_next);
  57    }
  58}
  59
  60/* m->m_data  points at ip packet header
  61 * m->m_len   length ip packet
  62 * ip->ip_len length data (IPDU)
  63 */
  64void
  65udp_input(register struct mbuf *m, int iphlen)
  66{
  67        Slirp *slirp = m->slirp;
  68        register struct ip *ip;
  69        register struct udphdr *uh;
  70        int len;
  71        struct ip save_ip;
  72        struct socket *so;
  73
  74        DEBUG_CALL("udp_input");
  75        DEBUG_ARG("m = %p", m);
  76        DEBUG_ARG("iphlen = %d", iphlen);
  77
  78        /*
  79         * Strip IP options, if any; should skip this,
  80         * make available to user, and use on returned packets,
  81         * but we don't yet have a way to check the checksum
  82         * with options still present.
  83         */
  84        if(iphlen > sizeof(struct ip)) {
  85                ip_stripoptions(m, (struct mbuf *)0);
  86                iphlen = sizeof(struct ip);
  87        }
  88
  89        /*
  90         * Get IP and UDP header together in first mbuf.
  91         */
  92        ip = mtod(m, struct ip *);
  93        uh = (struct udphdr *)((caddr_t)ip + iphlen);
  94
  95        /*
  96         * Make mbuf data length reflect UDP length.
  97         * If not enough data to reflect UDP length, drop.
  98         */
  99        len = ntohs((uint16_t)uh->uh_ulen);
 100
 101        if (ip->ip_len != len) {
 102                if (len > ip->ip_len) {
 103                        goto bad;
 104                }
 105                m_adj(m, len - ip->ip_len);
 106                ip->ip_len = len;
 107        }
 108
 109        /*
 110         * Save a copy of the IP header in case we want restore it
 111         * for sending an ICMP error message in response.
 112         */
 113        save_ip = *ip;
 114        save_ip.ip_len+= iphlen;         /* tcp_input subtracts this */
 115
 116        /*
 117         * Checksum extended UDP header and data.
 118         */
 119        if (uh->uh_sum) {
 120      memset(&((struct ipovly *)ip)->ih_mbuf, 0, sizeof(struct mbuf_ptr));
 121          ((struct ipovly *)ip)->ih_x1 = 0;
 122          ((struct ipovly *)ip)->ih_len = uh->uh_ulen;
 123          if(cksum(m, len + sizeof(struct ip))) {
 124            goto bad;
 125          }
 126        }
 127
 128        /*
 129         *  handle DHCP/BOOTP
 130         */
 131        if (ntohs(uh->uh_dport) == BOOTP_SERVER &&
 132            (ip->ip_dst.s_addr == slirp->vhost_addr.s_addr ||
 133             ip->ip_dst.s_addr == 0xffffffff)) {
 134                bootp_input(m);
 135                goto bad;
 136            }
 137
 138        /*
 139         *  handle TFTP
 140         */
 141        if (ntohs(uh->uh_dport) == TFTP_SERVER &&
 142            ip->ip_dst.s_addr == slirp->vhost_addr.s_addr) {
 143            tftp_input(m);
 144            goto bad;
 145        }
 146
 147        if (slirp->restricted) {
 148            goto bad;
 149        }
 150
 151        /*
 152         * Locate pcb for datagram.
 153         */
 154        so = slirp->udp_last_so;
 155        if (so == &slirp->udb || so->so_lport != uh->uh_sport ||
 156            so->so_laddr.s_addr != ip->ip_src.s_addr) {
 157                struct socket *tmp;
 158
 159                for (tmp = slirp->udb.so_next; tmp != &slirp->udb;
 160                     tmp = tmp->so_next) {
 161                        if (tmp->so_lport == uh->uh_sport &&
 162                            tmp->so_laddr.s_addr == ip->ip_src.s_addr) {
 163                                so = tmp;
 164                                break;
 165                        }
 166                }
 167                if (tmp == &slirp->udb) {
 168                  so = NULL;
 169                } else {
 170                  slirp->udp_last_so = so;
 171                }
 172        }
 173
 174        if (so == NULL) {
 175          /*
 176           * If there's no socket for this packet,
 177           * create one
 178           */
 179          so = socreate(slirp);
 180          if (!so) {
 181              goto bad;
 182          }
 183          if(udp_attach(so) == -1) {
 184            DEBUG_MISC((dfd," udp_attach errno = %d-%s\n",
 185                        errno,strerror(errno)));
 186            sofree(so);
 187            goto bad;
 188          }
 189
 190          /*
 191           * Setup fields
 192           */
 193          so->so_laddr = ip->ip_src;
 194          so->so_lport = uh->uh_sport;
 195
 196          if ((so->so_iptos = udp_tos(so)) == 0)
 197            so->so_iptos = ip->ip_tos;
 198
 199          /*
 200           * XXXXX Here, check if it's in udpexec_list,
 201           * and if it is, do the fork_exec() etc.
 202           */
 203        }
 204
 205        so->so_faddr = ip->ip_dst; /* XXX */
 206        so->so_fport = uh->uh_dport; /* XXX */
 207
 208        iphlen += sizeof(struct udphdr);
 209        m->m_len -= iphlen;
 210        m->m_data += iphlen;
 211
 212        /*
 213         * Now we sendto() the packet.
 214         */
 215        if(sosendto(so,m) == -1) {
 216          m->m_len += iphlen;
 217          m->m_data -= iphlen;
 218          *ip=save_ip;
 219          DEBUG_MISC((dfd,"udp tx errno = %d-%s\n",errno,strerror(errno)));
 220          icmp_error(m, ICMP_UNREACH,ICMP_UNREACH_NET, 0,strerror(errno));
 221        }
 222
 223        m_free(so->so_m);   /* used for ICMP if error on sorecvfrom */
 224
 225        /* restore the orig mbuf packet */
 226        m->m_len += iphlen;
 227        m->m_data -= iphlen;
 228        *ip=save_ip;
 229        so->so_m=m;         /* ICMP backup */
 230
 231        return;
 232bad:
 233        m_free(m);
 234}
 235
 236int udp_output2(struct socket *so, struct mbuf *m,
 237                struct sockaddr_in *saddr, struct sockaddr_in *daddr,
 238                int iptos)
 239{
 240        register struct udpiphdr *ui;
 241        int error = 0;
 242
 243        DEBUG_CALL("udp_output");
 244        DEBUG_ARG("so = %p", so);
 245        DEBUG_ARG("m = %p", m);
 246        DEBUG_ARG("saddr = %lx", (long)saddr->sin_addr.s_addr);
 247        DEBUG_ARG("daddr = %lx", (long)daddr->sin_addr.s_addr);
 248
 249        /*
 250         * Adjust for header
 251         */
 252        m->m_data -= sizeof(struct udpiphdr);
 253        m->m_len += sizeof(struct udpiphdr);
 254
 255        /*
 256         * Fill in mbuf with extended UDP header
 257         * and addresses and length put into network format.
 258         */
 259        ui = mtod(m, struct udpiphdr *);
 260    memset(&ui->ui_i.ih_mbuf, 0 , sizeof(struct mbuf_ptr));
 261        ui->ui_x1 = 0;
 262        ui->ui_pr = IPPROTO_UDP;
 263        ui->ui_len = htons(m->m_len - sizeof(struct ip));
 264        /* XXXXX Check for from-one-location sockets, or from-any-location sockets */
 265        ui->ui_src = saddr->sin_addr;
 266        ui->ui_dst = daddr->sin_addr;
 267        ui->ui_sport = saddr->sin_port;
 268        ui->ui_dport = daddr->sin_port;
 269        ui->ui_ulen = ui->ui_len;
 270
 271        /*
 272         * Stuff checksum and output datagram.
 273         */
 274        ui->ui_sum = 0;
 275        if ((ui->ui_sum = cksum(m, m->m_len)) == 0)
 276                ui->ui_sum = 0xffff;
 277        ((struct ip *)ui)->ip_len = m->m_len;
 278
 279        ((struct ip *)ui)->ip_ttl = IPDEFTTL;
 280        ((struct ip *)ui)->ip_tos = iptos;
 281
 282        error = ip_output(so, m);
 283
 284        return (error);
 285}
 286
 287int udp_output(struct socket *so, struct mbuf *m,
 288               struct sockaddr_in *addr)
 289
 290{
 291    Slirp *slirp = so->slirp;
 292    struct sockaddr_in saddr, daddr;
 293
 294    saddr = *addr;
 295    if ((so->so_faddr.s_addr & slirp->vnetwork_mask.s_addr) ==
 296        slirp->vnetwork_addr.s_addr) {
 297        uint32_t inv_mask = ~slirp->vnetwork_mask.s_addr;
 298
 299        if ((so->so_faddr.s_addr & inv_mask) == inv_mask) {
 300            saddr.sin_addr = slirp->vhost_addr;
 301        } else if (addr->sin_addr.s_addr == loopback_addr.s_addr ||
 302                   so->so_faddr.s_addr != slirp->vhost_addr.s_addr) {
 303            saddr.sin_addr = so->so_faddr;
 304        }
 305    }
 306    daddr.sin_addr = so->so_laddr;
 307    daddr.sin_port = so->so_lport;
 308
 309    return udp_output2(so, m, &saddr, &daddr, so->so_iptos);
 310}
 311
 312int
 313udp_attach(struct socket *so)
 314{
 315  if((so->s = qemu_socket(AF_INET,SOCK_DGRAM,0)) != -1) {
 316    so->so_expire = curtime + SO_EXPIRE;
 317    insque(so, &so->slirp->udb);
 318  }
 319  return(so->s);
 320}
 321
 322void
 323udp_detach(struct socket *so)
 324{
 325        closesocket(so->s);
 326        sofree(so);
 327}
 328
 329static const struct tos_t udptos[] = {
 330        {0, 53, IPTOS_LOWDELAY, 0},                     /* DNS */
 331        {0, 0, 0, 0}
 332};
 333
 334static uint8_t
 335udp_tos(struct socket *so)
 336{
 337        int i = 0;
 338
 339        while(udptos[i].tos) {
 340                if ((udptos[i].fport && ntohs(so->so_fport) == udptos[i].fport) ||
 341                    (udptos[i].lport && ntohs(so->so_lport) == udptos[i].lport)) {
 342                        so->so_emu = udptos[i].emu;
 343                        return udptos[i].tos;
 344                }
 345                i++;
 346        }
 347
 348        return 0;
 349}
 350
 351struct socket *
 352udp_listen(Slirp *slirp, uint32_t haddr, u_int hport, uint32_t laddr,
 353           u_int lport, int flags)
 354{
 355        struct sockaddr_in addr;
 356        struct socket *so;
 357        socklen_t addrlen = sizeof(struct sockaddr_in);
 358
 359        so = socreate(slirp);
 360        if (!so) {
 361            return NULL;
 362        }
 363        so->s = qemu_socket(AF_INET,SOCK_DGRAM,0);
 364        so->so_expire = curtime + SO_EXPIRE;
 365        insque(so, &slirp->udb);
 366
 367        addr.sin_family = AF_INET;
 368        addr.sin_addr.s_addr = haddr;
 369        addr.sin_port = hport;
 370
 371        if (bind(so->s,(struct sockaddr *)&addr, addrlen) < 0) {
 372                udp_detach(so);
 373                return NULL;
 374        }
 375        socket_set_fast_reuse(so->s);
 376
 377        getsockname(so->s,(struct sockaddr *)&addr,&addrlen);
 378        so->so_fport = addr.sin_port;
 379        if (addr.sin_addr.s_addr == 0 ||
 380            addr.sin_addr.s_addr == loopback_addr.s_addr) {
 381           so->so_faddr = slirp->vhost_addr;
 382        } else {
 383           so->so_faddr = addr.sin_addr;
 384        }
 385        so->so_lport = lport;
 386        so->so_laddr.s_addr = laddr;
 387        if (flags != SS_FACCEPTONCE)
 388           so->so_expire = 0;
 389
 390        so->so_state &= SS_PERSISTENT_MASK;
 391        so->so_state |= SS_ISFCONNECTED | flags;
 392
 393        return so;
 394}
 395