bsd/netat/aurp_aurpd.c

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  *      Copyright (c) 1996 Apple Computer, Inc.
  24  *
  25  *              Created April 25, 1996, by Justin C. Walker
  26  *   Modified, March 17, 1997 by Tuyen Nguyen for MacOSX.
  27  *
  28  *      File: aurpd.c
  29  */
  30
  31 /*
  32  * Kernel process to implement the AURP daemon:
  33  *  manage tunnels to remote AURP servers across IP networks
  34  */
  35
  36 #include <sys/errno.h>
  37 #include <sys/types.h>
  38 #include <sys/param.h>
  39 #include <machine/spl.h>
  40 #include <sys/systm.h>
  41 #include <sys/kernel.h>
  42 #include <sys/proc.h>
  43 #include <sys/filedesc.h>
  44 #include <sys/fcntl.h>
  45 #include <sys/mbuf.h>
  46 #include <sys/socket.h>
  47 #include <sys/socketvar.h>
  48 #include <sys/protosw.h>
  49 #include <sys/malloc.h>
  50 #include <sys/proc.h>
  51 #include <netinet/in.h>
  52 #include <net/if.h>
  53
  54 #include <netat/sysglue.h>
  55 #include <netat/appletalk.h>
  56 #include <netat/at_var.h>
  57 #include <netat/routing_tables.h>
  58 #include <netat/at_pcb.h>
  59 #include <netat/aurp.h>
  60 #include <netat/debug.h>
  61
  62 #define M_RCVBUF (64 * 1024)
  63 #define M_SNDBUF (64 * 1024)
  64
  65 static int ip_to_atalk(struct sockaddr_in *fp, register gbuf_t *p_mbuf);
  66 static int aurp_bindrp(struct socket *so);
  67
  68 struct aurp_global_t aurp_global;
  69
  70 /*
  71  * Initialize the aurp pipe -
  72  * -Create, initialize, and start the aurpd kernel process; we need
  73  *  a process to permit queueing between the socket and the stream,
  74  *  which is necessary for orderly access to the socket structure.
  75  * -The user process (aurpd) is there to 'build' the AURP
  76  *  stream, act as a 'logging agent' (:-}), and hold open the stream
  77  *  during its use.
  78  * -Data and AURP packets from the DDP stream will be fed into the
  79  *  UDP tunnel (AURPsend())
  80  * -Data and AURP packets from the UDP tunnel will be fed into the
  81  *  DDP stream (ip_to_atalk(), via the kernel process).
  82  */
  83 int
  84 aurpd_start()
  85 {
  86         register int error;
  87         register struct socket *so;
  88         struct mbuf *m;
  89         int maxbuf;
  90         struct sockopt sopt;
  91
  92         if (suser(current_proc()->p_ucred, &current_proc()->p_acflag) != 0 )
  93                 return(EPERM);
  94
  95         /*
  96          * Set up state prior to starting kernel process so we can back out
  97          *  (error return) if something goes wrong.
  98          */
  99         bzero((char *)&aurp_global.tunnel, sizeof(aurp_global.tunnel));
 100         /*lock_alloc(&aurp_global.glock, LOCK_ALLOC_PIN, AURP_EVNT_LOCK, -1);*/
 101         ATLOCKINIT(aurp_global.glock);
 102         ATEVENTINIT(aurp_global.event_anchor);
 103
 104         /* open udp socket */
 105         if (aurp_global.udp_port == 0)
 106                 aurp_global.udp_port = AURP_SOCKNUM;
 107         error = socreate(AF_INET, &aurp_global.tunnel, SOCK_DGRAM,
 108                          IPPROTO_UDP);
 109         if (error)
 110         {       dPrintf(D_M_AURP, D_L_FATAL, ("AURP: Can't get socket (%d)\n",
 111                         error));
 112                 return(error);
 113         }
 114
 115         so = aurp_global.tunnel;
 116
 117         if ((error = aurp_bindrp(so)) != 0)
 118         {       dPrintf(D_M_AURP, D_L_FATAL,
 119                         ("AURP: Can't bind to port %d (error %d)\n",
 120                         aurp_global.udp_port, error));
 121                 soclose(so);
 122                 return(error);
 123         }
 124
 125         sblock(&so->so_rcv, M_WAIT);
 126         sblock(&so->so_snd, M_WAIT);
 127
 128         /*
 129          * Set socket Receive buffer size
 130          */
 131         m = m_get(M_WAIT, MT_SOOPTS);
 132         if (m == NULL) {
 133                 error = ENOBUFS;
 134                 goto out;
 135         } else {
 136                 maxbuf = M_RCVBUF;
 137                 sopt.sopt_val     = &maxbuf;
 138                 sopt.sopt_valsize = sizeof(maxbuf);
 139                 sopt.sopt_level   = SOL_SOCKET;
 140                 sopt.sopt_name    = SO_RCVBUF;
 141                 sopt.sopt_dir     = SOPT_SET;
 142                 if ((error = sosetopt(so, &sopt)) != 0)
 143                         goto out;
 144         }
 145
 146         /*
 147          * Set socket Send buffer size
 148          */
 149         m = m_get(M_WAIT, MT_SOOPTS);
 150         if (m == NULL) {
 151                 error = ENOBUFS;
 152                 goto out;
 153         } else {
 154
 155                 maxbuf = M_SNDBUF;
 156                 sopt.sopt_val     = &maxbuf;
 157                 sopt.sopt_valsize = sizeof(maxbuf);
 158                 sopt.sopt_level   = SOL_SOCKET;
 159                 sopt.sopt_name    = SO_SNDBUF;
 160                 sopt.sopt_dir     = SOPT_SET;
 161                 if ((error = sosetopt(so, &sopt)) != 0)
 162                         goto out;
 163         }
 164
 165         so->so_upcall = aurp_wakeup;
 166         so->so_upcallarg = (caddr_t)AE_UDPIP; /* Yuck */
 167         so->so_state |= SS_NBIO;
 168         so->so_rcv.sb_flags |=SB_NOINTR;
 169         so->so_rcv.sb_sel.si_flags |=SI_SBSEL;
 170         so->so_snd.sb_flags |=SB_NOINTR;
 171         so->so_snd.sb_sel.si_flags |=SI_SBSEL;
 172
 173 out:
 174         sbunlock(&so->so_snd);
 175         sbunlock(&so->so_rcv);
 176
 177         return(error);
 178 }
 179
 180 int
 181 AURPgetmsg(err)
 182         int *err;
 183 {       register struct socket *so;
 184         register int s, events;
 185
 186         so = aurp_global.tunnel;
 187         *err = 0;
 188
 189         for (;;)
 190         {       gbuf_t *from, *p_mbuf;
 191                 int flags = MSG_DONTWAIT;
 192                 struct uio auio;
 193
 194                 /*
 195                  * Wait for a package to arrive.  This will be from the
 196                  * IP side - sowakeup() calls aurp_wakeup()
 197                  *           when a packet arrives
 198                  */
 199
 200                 ATDISABLE(s, aurp_global.glock);
 201                 events = aurp_global.event;
 202                 if (((*err == 0) || (*err == EWOULDBLOCK)) && events == 0)
 203                   {
 204                     *err = tsleep(&aurp_global.event_anchor, PSOCK | PCATCH, "AURPgetmsg", 0);
 205                     events = aurp_global.event;
 206                     aurp_global.event = 0;
 207                   }
 208                 ATENABLE(s, aurp_global.glock);
 209
 210                 /*
 211                  * Shut down if we have the AE_SHUTDOWN event or if we got
 212                  * a system error other than EWOULDBLOCK, such as EINTR.
 213                  */
 214                 if (((*err != EWOULDBLOCK) && (*err != 0)) || events & AE_SHUTDOWN)
 215                   {
 216                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 217                         ("AURPgetmsg: AE_SHUTDOWN detected--starting shutdown sequence\n"));
 218                     aurp_global.shutdown = 1;
 219                     while (aurp_global.running)
 220                         ;
 221                     /*lock_free(&aurp_global.glock);*/
 222                     aurp_global.tunnel = 0;
 223                     aurp_global.event = 0;
 224                     aurp_global.shutdown = 0;
 225                     soclose(so);
 226                     if (*err == 0)
 227                     *err = ESHUTDOWN;
 228                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 229                         ("AURPgetmsg: shutdown completed\n"));
 230                     return -1;
 231                   }
 232
 233
 234
 235                 /*
 236                  * Set up the nominal uio structure -
 237                  *  give it no iov's, point off to non-existant user space,
 238                  *  but make sure the 'resid' count means somehting.
 239                  */
 240
 241                 auio.uio_iov = NULL;
 242                 auio.uio_iovcnt = 0;
 243                 auio.uio_segflg = UIO_SYSSPACE;
 244                 auio.uio_offset = 0;                    /* XXX */
 245
 246                 /* Keep up an even flow... */
 247                 for (;;)
 248                 {
 249 /*
 250  * This should be large enough to encompass a full DDP packet plus
 251  *  domain header.
 252  */
 253 #define A_LARGE_SIZE 700
 254
 255                         flags = MSG_DONTWAIT;
 256                         auio.uio_resid = A_LARGE_SIZE;
 257                         *err = soreceive(so, (struct sockaddr **)&from, &auio, &p_mbuf, 0, &flags);
 258                         dPrintf(D_M_AURP, D_L_VERBOSE,
 259                                 ("AURPgetmsg: soreceive returned %d, aurp_global.event==0x%x\n", *err, events));
 260                         /* soreceive() sets *mp to zero! at start */
 261                         if (p_mbuf)
 262                                 ip_to_atalk(from, p_mbuf);
 263                         if (*err || (p_mbuf == NULL)) {
 264                                 /*
 265                                  * An error occurred in soreceive(),
 266                                  * so clear the data input event flag
 267                                  * and break out of this inner loop.
 268                                  *
 269                                  * XXX Note that clearing AE_UDPIP here could
 270                                  * cause us to lose an AE_UDPIP event that
 271                                  * was posted in aurp_global.event between
 272                                  * the soreceive() above and the code here.
 273                                  * The protocol should recover from this
 274                                  * lost event, though, since the next
 275                                  * request (a tickle, for example) from
 276                                  * the other end of the tunnel will cause
 277                                  * another AE_UDPIP event to be posted,
 278                                  * which will wake us from the sleep at
 279                                  * the top of the outer loop.
 280                                  */
 281                                 int s;
 282                                 ATDISABLE(s, aurp_global.glock);
 283                                 aurp_global.event &= ~AE_UDPIP;
 284                                 ATENABLE(s, aurp_global.glock);
 285                                 dPrintf(D_M_AURP, D_L_WARNING, ("AURPgetmsg: spurious soreceive, err==%d, p_mbuf==0x%x\n", *err, (unsigned int) p_mbuf));
 286                           break;
 287                 }
 288         }
 289         }
 290         return -1;
 291 }
 292
 293 /*
 294  * Wakeup the sleeping giant - we've put a message on his queue(s).
 295  * The arg indicates what queue has been updated.
 296  *
 297  * This conforms to the so_upcall function pointer member of struct sockbuf.
 298  */
 299 void aurp_wakeup(struct socket *so, register caddr_t p, int state)
 300 {
 301         register int s;
 302         register int bit;
 303
 304         bit = (int) p;
 305         ATDISABLE(s, aurp_global.glock);
 306         aurp_global.event |= bit;
 307         ATENABLE(s, aurp_global.glock);
 308
 309         dPrintf(D_M_AURP, D_L_STATE_CHG,
 310                 ("aurp_wakeup: bit 0x%x, aurp_global.event now 0x%x\n",
 311                 bit, aurp_global.event));
 312
 313         thread_wakeup(&aurp_global.event_anchor);
 314 }
 315
 316 /*
 317  * Try to bind to the specified reserved port.
 318  * Sort of like sobind(), but no suser() check.
 319  */
 320 static int
 321 aurp_bindrp(struct socket *so)
 322 {
 323         struct sockaddr_in sin;
 324         struct proc *p = current_proc();
 325         gbuf_t *m;
 326         int error;
 327
 328
 329         bzero(&sin, sizeof(sin));
 330         sin.sin_family      = AF_INET;
 331         sin.sin_addr.s_addr = htons(aurp_global.src_addr);
 332         sin.sin_port        = htons(aurp_global.udp_port);
 333         sin.sin_len         = sizeof(struct sockaddr_in);
 334
 335         sblock(&so->so_rcv, M_WAIT);
 336         sblock(&so->so_snd, M_WAIT);
 337         so->so_state |= SS_PRIV;
 338         error = (*so->so_proto->pr_usrreqs->pru_bind)(so, (struct sockaddr *) &sin, p);
 339         sbunlock(&so->so_snd);
 340         sbunlock(&so->so_rcv);
 341
 342         return (error);
 343 }
 344
 345 /*
 346  * receive from UDP
 347  * fp is the 'source address' mbuf; p_mbuf is the data mbuf.
 348  * Use the source address to find the 'node number' (index of the address),
 349  *  and pass that to the next stage.
 350  */
 351 int ip_to_atalk(register struct sockaddr_in *rem_addr, register gbuf_t *p_mbuf)
 352 {
 353         register aurp_domain_t *domain;
 354         unsigned char node;
 355
 356
 357         /* determine the node where the packet came from */
 358         for (node=1; node <= dst_addr_cnt; node++) {
 359                 if (aurp_global.dst_addr[node] == *(long *)&rem_addr->sin_addr)
 360                         break;
 361         }
 362         if (node > dst_addr_cnt) {
 363                 dPrintf(D_M_AURP, D_L_WARNING,
 364                         ("AURPrecv: invalid node, %d.%lx\n",
 365                         rem_addr->sin_port,
 366                         rem_addr->sin_addr.s_addr));
 367
 368                 gbuf_freem(p_mbuf);
 369                 FREE(rem_addr, M_SONAME);
 370                 return -1;
 371         }
 372
 373         /* validate the domain */
 374         domain = (aurp_domain_t *)gbuf_rptr(p_mbuf);
 375         if ( (domain->dst_length != IP_LENGTH) ||
 376             (domain->dst_authority != IP_AUTHORITY) ||
 377             (domain->version != AUD_Version) ||
 378             ((domain->type != AUD_Atalk) && (domain->type != AUD_AURP)) ) {
 379                 dPrintf(D_M_AURP, D_L_WARNING,
 380                         ("AURPrecv: invalid domain, %d.%lx\n",
 381                         rem_addr->sin_port,
 382                         rem_addr->sin_addr.s_addr));
 383
 384                 gbuf_freem(p_mbuf);
 385                 FREE(rem_addr, M_SONAME);
 386                 return -1;
 387         }
 388
 389         /* Remove domain header */
 390         p_mbuf->m_pkthdr.len -= IP_DOMAINSIZE;
 391         gbuf_rinc(p_mbuf,IP_DOMAINSIZE);
 392         gbuf_set_type(p_mbuf, MSG_DATA);
 393
 394         /* forward the packet to the local AppleTalk stack */
 395
 396         at_insert(p_mbuf, domain->type, node);
 397         FREE(rem_addr, M_SONAME);
 398         return 0;
 399 }
 400
 401 /*
 402  * send to UDP
 403  * The real work has been done already.  Here, we just cobble together
 404  *  a sockaddr for the destination and call sosend().
 405  */
 406 void
 407 atalk_to_ip(register gbuf_t *m)
 408 {       register aurp_domain_t *domain;
 409         int error;
 410         int flags = MSG_DONTWAIT;
 411         struct sockaddr_in rem_addr;
 412         int s;
 413
 414         m->m_type = MT_HEADER;
 415         m->m_pkthdr.len = gbuf_msgsize(m);
 416         m->m_pkthdr.rcvif = 0;
 417
 418         bzero((char *) &rem_addr, sizeof(rem_addr));
 419         rem_addr.sin_family = PF_INET;
 420         rem_addr.sin_port = aurp_global.udp_port;
 421         rem_addr.sin_len  = sizeof (struct sockaddr_in);
 422         domain = (aurp_domain_t *)gbuf_rptr(m);
 423         *(long *) &rem_addr.sin_addr = domain->dst_address;
 424
 425         ATDISABLE(s, aurp_global.glock);
 426         aurp_global.running++;
 427         ATENABLE(s, aurp_global.glock);
 428         if (aurp_global.shutdown) {
 429                 gbuf_freem(m);
 430                         ATDISABLE(s, aurp_global.glock);
 431                 aurp_global.running--;
 432                 ATENABLE(s, aurp_global.glock);
 433                 dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 434                         ("atalk_to_ip: detected aurp_global.shutdown state\n"));
 435                 return;
 436         }
 437         dPrintf(D_M_AURP, D_L_VERBOSE, ("atalk_to_ip: calling sosend\n"));
 438         error = sosend(aurp_global.tunnel, (struct sockaddr *) &rem_addr, NULL, m, NULL, flags);
 439         if (error)
 440         {       /*log error*/
 441           dPrintf(D_M_AURP, D_L_ERROR, ("AURP: sosend error (%d)\n",
 442                   error));
 443         }
 444
 445         ATDISABLE(s, aurp_global.glock);
 446         aurp_global.running--;
 447         ATENABLE(s, aurp_global.glock);
 448         return;
 449 }
 450