bsd/netat/aurp_aurpd.c

   1 /*
   2  * Copyright (c) 2000-2004 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*
  29  *      Copyright (c) 1996 Apple Computer, Inc.
  30  *
  31  *              Created April 25, 1996, by Justin C. Walker
  32  *   Modified, March 17, 1997 by Tuyen Nguyen for MacOSX.
  33  *
  34  *      File: aurpd.c
  35  */
  36
  37 /*
  38  * Kernel process to implement the AURP daemon:
  39  *  manage tunnels to remote AURP servers across IP networks
  40  */
  41 #ifdef AURP_SUPPORT
  42
  43 #include <sys/errno.h>
  44 #include <sys/types.h>
  45 #include <sys/param.h>
  46 #include <machine/spl.h>
  47 #include <sys/systm.h>
  48 #include <sys/kernel.h>
  49 #include <sys/proc.h>
  50 #include <sys/kauth.h>
  51 #include <sys/filedesc.h>
  52 #include <sys/fcntl.h>
  53 #include <sys/mbuf.h>
  54 #include <sys/socket.h>
  55 #include <sys/socketvar.h>
  56 #include <sys/protosw.h>
  57 #include <sys/malloc.h>
  58 #include <sys/proc.h>
  59 #include <sys/uio_internal.h>
  60 #include <kern/locks.h>
  61 #include <netinet/in.h>
  62 #include <net/if.h>
  63
  64 #include <netat/sysglue.h>
  65 #include <netat/appletalk.h>
  66 #include <netat/at_pcb.h>
  67 #include <netat/at_var.h>
  68 #include <netat/routing_tables.h>
  69 #include <netat/at_pcb.h>
  70 #include <netat/aurp.h>
  71 #include <netat/debug.h>
  72
  73 #define M_RCVBUF (64 * 1024)
  74 #define M_SNDBUF (64 * 1024)
  75
  76 extern lck_mtx_t * atalk_mutex;
  77
  78 static int ip_to_atalk(struct sockaddr_in *fp, register gbuf_t *p_mbuf);
  79 static int aurp_bindrp(struct socket *so);
  80
  81 struct aurp_global_t aurp_global;
  82
  83 /*
  84  * Initialize the aurp pipe -
  85  * -Create, initialize, and start the aurpd kernel process; we need
  86  *  a process to permit queueing between the socket and the stream,
  87  *  which is necessary for orderly access to the socket structure.
  88  * -The user process (aurpd) is there to 'build' the AURP
  89  *  stream, act as a 'logging agent' (:-}), and hold open the stream
  90  *  during its use.
  91  * -Data and AURP packets from the DDP stream will be fed into the
  92  *  UDP tunnel (AURPsend())
  93  * -Data and AURP packets from the UDP tunnel will be fed into the
  94  *  DDP stream (ip_to_atalk(), via the kernel process).
  95  */
  96 int
  97 aurpd_start()
  98 {
  99         register int error;
 100         register struct socket *so;
 101         struct mbuf *m;
 102         int maxbuf;
 103         struct sockopt sopt;
 104
 105         if (suser(kauth_cred_get(), 0) != 0 )
 106                 return(EPERM);
 107
 108         /*
 109          * Set up state prior to starting kernel process so we can back out
 110          *  (error return) if something goes wrong.
 111          */
 112         bzero((char *)&aurp_global.tunnel, sizeof(aurp_global.tunnel));
 113         /*lock_alloc(&aurp_global.glock, LOCK_ALLOC_PIN, AURP_EVNT_LOCK, -1);*/
 114         ATEVENTINIT(aurp_global.event_anchor);
 115
 116         /* open udp socket */
 117         if (aurp_global.udp_port == 0)
 118                 aurp_global.udp_port = AURP_SOCKNUM;
 119         error = socreate(AF_INET, &aurp_global.tunnel, SOCK_DGRAM,
 120                          IPPROTO_UDP);
 121         if (error)
 122         {       dPrintf(D_M_AURP, D_L_FATAL, ("AURP: Can't get socket (%d)\n",
 123                         error));
 124                 return(error);
 125         }
 126
 127         so = aurp_global.tunnel;
 128
 129         if ((error = aurp_bindrp(so)) != 0)
 130         {       dPrintf(D_M_AURP, D_L_FATAL,
 131                         ("AURP: Can't bind to port %d (error %d)\n",
 132                         aurp_global.udp_port, error));
 133                 soclose(so);
 134                 return(error);
 135         }
 136
 137         sblock(&so->so_rcv, M_WAIT);
 138         sblock(&so->so_snd, M_WAIT);
 139
 140         /*
 141          * Set socket Receive buffer size
 142          */
 143         m = m_get(M_WAIT, MT_SOOPTS);
 144         if (m == NULL) {
 145                 error = ENOBUFS;
 146                 goto out;
 147         } else {
 148                 maxbuf = M_RCVBUF;
 149                 sopt.sopt_val     = CAST_USER_ADDR_T(&maxbuf);
 150                 sopt.sopt_valsize = sizeof(maxbuf);
 151                 sopt.sopt_level   = SOL_SOCKET;
 152                 sopt.sopt_name    = SO_RCVBUF;
 153                 sopt.sopt_dir     = SOPT_SET;
 154                 sopt.sopt_p               = NULL;
 155                 if ((error = sosetopt(so, &sopt)) != 0)
 156                         goto out;
 157         }
 158
 159         /*
 160          * Set socket Send buffer size
 161          */
 162         m = m_get(M_WAIT, MT_SOOPTS);
 163         if (m == NULL) {
 164                 error = ENOBUFS;
 165                 goto out;
 166         } else {
 167
 168                 maxbuf = M_SNDBUF;
 169                 sopt.sopt_val     = CAST_USER_ADDR_T(&maxbuf);
 170                 sopt.sopt_valsize = sizeof(maxbuf);
 171                 sopt.sopt_level   = SOL_SOCKET;
 172                 sopt.sopt_name    = SO_SNDBUF;
 173                 sopt.sopt_dir     = SOPT_SET;
 174                 sopt.sopt_p               = NULL;
 175                 if ((error = sosetopt(so, &sopt)) != 0)
 176                         goto out;
 177         }
 178
 179         so->so_upcall = aurp_wakeup;
 180         so->so_upcallarg = (caddr_t)AE_UDPIP; /* Yuck */
 181         so->so_state |= SS_NBIO;
 182         so->so_rcv.sb_flags |=(SB_SEL|SB_NOINTR);
 183         so->so_snd.sb_flags |=(SB_SEL|SB_NOINTR);
 184
 185 out:
 186         sbunlock(&so->so_snd, 0);
 187         sbunlock(&so->so_rcv, 0);
 188
 189         return(error);
 190 }
 191
 192 int
 193 AURPgetmsg(err)
 194         int *err;
 195 {       register struct socket *so;
 196         register int events;
 197
 198         so = aurp_global.tunnel;
 199         *err = 0;
 200
 201         for (;;)
 202         {       gbuf_t *from, *p_mbuf;
 203                 int flags = MSG_DONTWAIT;
 204                 uio_t auio;
 205                 char uio_buf[ UIO_SIZEOF(0) ];
 206
 207                 /*
 208                  * Wait for a package to arrive.  This will be from the
 209                  * IP side - sowakeup() calls aurp_wakeup()
 210                  *           when a packet arrives
 211                  */
 212
 213                 events = aurp_global.event;
 214                 if (((*err == 0) || (*err == EWOULDBLOCK)) && events == 0)
 215                   {
 216                         lck_mtx_assert(atalk_mutex, LCK_MTX_ASSERT_OWNED);
 217                     *err = msleep(&aurp_global.event_anchor, atalk_mutex, PSOCK | PCATCH, "AURPgetmsg", 0);
 218                     events = aurp_global.event;
 219                     aurp_global.event = 0;
 220                   }
 221
 222                 /*
 223                  * Shut down if we have the AE_SHUTDOWN event or if we got
 224                  * a system error other than EWOULDBLOCK, such as EINTR.
 225                  */
 226                 if (((*err != EWOULDBLOCK) && (*err != 0)) || events & AE_SHUTDOWN)
 227                   {
 228                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 229                         ("AURPgetmsg: AE_SHUTDOWN detected--starting shutdown sequence\n"));
 230                     aurp_global.shutdown = 1;
 231                     while (aurp_global.running)
 232                         ;
 233                     /*lock_free(&aurp_global.glock);*/
 234                     aurp_global.tunnel = 0;
 235                     aurp_global.event = 0;
 236                     aurp_global.shutdown = 0;
 237                     soclose(so);
 238                     if (*err == 0)
 239                     *err = ESHUTDOWN;
 240                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 241                         ("AURPgetmsg: shutdown completed\n"));
 242                     return -1;
 243                   }
 244
 245
 246
 247                 /*
 248                  * Set up the nominal uio structure -
 249                  *  give it no iov's, point off to non-existant user space,
 250                  *  but make sure the 'resid' count means somehting.
 251                  */
 252                 auio = uio_createwithbuffer(0, 0, UIO_SYSSPACE, UIO_READ,
 253                                                                   &uio_buf[0], sizeof(uio_buf));
 254
 255                 /* Keep up an even flow... */
 256                 for (;;)
 257                 {
 258 /*
 259  * This should be large enough to encompass a full DDP packet plus
 260  *  domain header.
 261  */
 262 #define A_LARGE_SIZE 700
 263
 264                         flags = MSG_DONTWAIT;
 265                         uio_setresid(auio, A_LARGE_SIZE);
 266                         *err = soreceive(so, (struct sockaddr **)&from, auio, &p_mbuf, 0, &flags);
 267                         dPrintf(D_M_AURP, D_L_VERBOSE,
 268                                 ("AURPgetmsg: soreceive returned %d, aurp_global.event==0x%x\n", *err, events));
 269                         /* soreceive() sets *mp to zero! at start */
 270                         if (p_mbuf)
 271                                 ip_to_atalk((struct sockaddr_in *)from, p_mbuf);
 272                         if (*err || (p_mbuf == NULL)) {
 273                                 /*
 274                                  * An error occurred in soreceive(),
 275                                  * so clear the data input event flag
 276                                  * and break out of this inner loop.
 277                                  *
 278                                  * XXX Note that clearing AE_UDPIP here could
 279                                  * cause us to lose an AE_UDPIP event that
 280                                  * was posted in aurp_global.event between
 281                                  * the soreceive() above and the code here.
 282                                  * The protocol should recover from this
 283                                  * lost event, though, since the next
 284                                  * request (a tickle, for example) from
 285                                  * the other end of the tunnel will cause
 286                                  * another AE_UDPIP event to be posted,
 287                                  * which will wake us from the sleep at
 288                                  * the top of the outer loop.
 289                                  */
 290                                 aurp_global.event &= ~AE_UDPIP;
 291                                 dPrintf(D_M_AURP, D_L_WARNING, ("AURPgetmsg: spurious soreceive, err==%d, p_mbuf==0x%x\n", *err, (unsigned int) p_mbuf));
 292                           break;
 293                 }
 294         }
 295         }
 296         return -1;
 297 }
 298
 299 /*
 300  * Wakeup the sleeping giant - we've put a message on his queue(s).
 301  * The arg indicates what queue has been updated.
 302  *
 303  * This conforms to the so_upcall function pointer member of struct sockbuf.
 304  */
 305 void aurp_wakeup(__unused struct socket *so, register caddr_t p, __unused int state)
 306 {
 307         register int bit;
 308
 309         bit = (int) p;
 310         aurp_global.event |= bit;
 311
 312         dPrintf(D_M_AURP, D_L_STATE_CHG,
 313                 ("aurp_wakeup: bit 0x%x, aurp_global.event now 0x%x\n",
 314                 bit, aurp_global.event));
 315
 316         wakeup(&aurp_global.event_anchor);
 317 }
 318
 319 /*
 320  * Try to bind to the specified reserved port.
 321  * Sort of like sobind(), but no suser() check.
 322  */
 323 static int
 324 aurp_bindrp(struct socket *so)
 325 {
 326         struct sockaddr_in sin;
 327         struct proc *p = current_proc();
 328         int error;
 329
 330
 331         bzero(&sin, sizeof(sin));
 332         sin.sin_family      = AF_INET;
 333         sin.sin_addr.s_addr = htons(aurp_global.src_addr);
 334         sin.sin_port        = htons(aurp_global.udp_port);
 335         sin.sin_len         = sizeof(struct sockaddr_in);
 336
 337         sblock(&so->so_rcv, M_WAIT);
 338         sblock(&so->so_snd, M_WAIT);
 339         so->so_state |= SS_PRIV;
 340         error = (*so->so_proto->pr_usrreqs->pru_bind)(so, (struct sockaddr *) &sin, p);
 341         sbunlock(&so->so_snd, 0);
 342         sbunlock(&so->so_rcv, 0);
 343
 344         return (error);
 345 }
 346
 347 /*
 348  * receive from UDP
 349  * fp is the 'source address' mbuf; p_mbuf is the data mbuf.
 350  * Use the source address to find the 'node number' (index of the address),
 351  *  and pass that to the next stage.
 352  */
 353 int ip_to_atalk(register struct sockaddr_in *rem_addr, register gbuf_t *p_mbuf)
 354 {
 355         register aurp_domain_t *domain;
 356         unsigned char node;
 357
 358
 359         /* determine the node where the packet came from */
 360         for (node=1; node <= dst_addr_cnt; node++) {
 361                 if (aurp_global.dst_addr[node] == *(long *)&rem_addr->sin_addr)
 362                         break;
 363         }
 364         if (node > dst_addr_cnt) {
 365                 dPrintf(D_M_AURP, D_L_WARNING,
 366                         ("AURPrecv: invalid node, %d.%lx\n",
 367                         rem_addr->sin_port,
 368                         rem_addr->sin_addr.s_addr));
 369
 370                 gbuf_freem(p_mbuf);
 371                 FREE(rem_addr, M_SONAME);
 372                 return -1;
 373         }
 374
 375         /* validate the domain */
 376         domain = (aurp_domain_t *)gbuf_rptr(p_mbuf);
 377         if ( (domain->dst_length != IP_LENGTH) ||
 378             (domain->dst_authority != IP_AUTHORITY) ||
 379             (domain->version != AUD_Version) ||
 380             ((domain->type != AUD_Atalk) && (domain->type != AUD_AURP)) ) {
 381                 dPrintf(D_M_AURP, D_L_WARNING,
 382                         ("AURPrecv: invalid domain, %d.%lx\n",
 383                         rem_addr->sin_port,
 384                         rem_addr->sin_addr.s_addr));
 385
 386                 gbuf_freem(p_mbuf);
 387                 FREE(rem_addr, M_SONAME);
 388                 return -1;
 389         }
 390
 391         /* Remove domain header */
 392         p_mbuf->m_pkthdr.len -= IP_DOMAINSIZE;
 393         gbuf_rinc(p_mbuf,IP_DOMAINSIZE);
 394         gbuf_set_type(p_mbuf, MSG_DATA);
 395
 396         /* forward the packet to the local AppleTalk stack */
 397
 398         at_insert(p_mbuf, domain->type, node);
 399         FREE(rem_addr, M_SONAME);
 400         return 0;
 401 }
 402
 403 /*
 404  * send to UDP
 405  * The real work has been done already.  Here, we just cobble together
 406  *  a sockaddr for the destination and call sosend().
 407  */
 408 void
 409 atalk_to_ip(register gbuf_t *m)
 410 {       register aurp_domain_t *domain;
 411         int error;
 412         int flags = MSG_DONTWAIT;
 413         struct sockaddr_in rem_addr;
 414
 415         m_mchtype(m, MT_HEADER);
 416         m->m_pkthdr.len = gbuf_msgsize(m);
 417         m->m_pkthdr.rcvif = 0;
 418
 419         bzero((char *) &rem_addr, sizeof(rem_addr));
 420         rem_addr.sin_family = PF_INET;
 421         rem_addr.sin_port = aurp_global.udp_port;
 422         rem_addr.sin_len  = sizeof (struct sockaddr_in);
 423         domain = (aurp_domain_t *)gbuf_rptr(m);
 424         *(long *) &rem_addr.sin_addr = domain->dst_address;
 425
 426         aurp_global.running++;
 427         if (aurp_global.shutdown) {
 428                 gbuf_freem(m);
 429                 aurp_global.running--;
 430                 dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 431                         ("atalk_to_ip: detected aurp_global.shutdown state\n"));
 432                 return;
 433         }
 434         dPrintf(D_M_AURP, D_L_VERBOSE, ("atalk_to_ip: calling sosend\n"));
 435         error = sosend(aurp_global.tunnel, (struct sockaddr *) &rem_addr, NULL, m, NULL, flags);
 436         if (error)
 437         {       /*log error*/
 438           dPrintf(D_M_AURP, D_L_ERROR, ("AURP: sosend error (%d)\n",
 439                   error));
 440         }
 441
 442         aurp_global.running--;
 443         return;
 444 }
 445
 446 #endif  /* AURP_SUPPORT */