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
  42 #include <sys/errno.h>
  43 #include <sys/types.h>
  44 #include <sys/param.h>
  45 #include <machine/spl.h>
  46 #include <sys/systm.h>
  47 #include <sys/kernel.h>
  48 #include <sys/proc.h>
  49 #include <sys/kauth.h>
  50 #include <sys/filedesc.h>
  51 #include <sys/fcntl.h>
  52 #include <sys/mbuf.h>
  53 #include <sys/socket.h>
  54 #include <sys/socketvar.h>
  55 #include <sys/protosw.h>
  56 #include <sys/malloc.h>
  57 #include <sys/proc.h>
  58 #include <sys/uio_internal.h>
  59 #include <kern/locks.h>
  60 #include <netinet/in.h>
  61 #include <net/if.h>
  62
  63 #include <netat/sysglue.h>
  64 #include <netat/appletalk.h>
  65 #include <netat/at_var.h>
  66 #include <netat/routing_tables.h>
  67 #include <netat/at_pcb.h>
  68 #include <netat/aurp.h>
  69 #include <netat/debug.h>
  70
  71 #define M_RCVBUF (64 * 1024)
  72 #define M_SNDBUF (64 * 1024)
  73
  74 extern lck_mtx_t * atalk_mutex;
  75
  76 static int ip_to_atalk(struct sockaddr_in *fp, register gbuf_t *p_mbuf);
  77 static int aurp_bindrp(struct socket *so);
  78
  79 struct aurp_global_t aurp_global;
  80
  81 /*
  82  * Initialize the aurp pipe -
  83  * -Create, initialize, and start the aurpd kernel process; we need
  84  *  a process to permit queueing between the socket and the stream,
  85  *  which is necessary for orderly access to the socket structure.
  86  * -The user process (aurpd) is there to 'build' the AURP
  87  *  stream, act as a 'logging agent' (:-}), and hold open the stream
  88  *  during its use.
  89  * -Data and AURP packets from the DDP stream will be fed into the
  90  *  UDP tunnel (AURPsend())
  91  * -Data and AURP packets from the UDP tunnel will be fed into the
  92  *  DDP stream (ip_to_atalk(), via the kernel process).
  93  */
  94 int
  95 aurpd_start()
  96 {
  97         register int error;
  98         register struct socket *so;
  99         struct mbuf *m;
 100         int maxbuf;
 101         struct sockopt sopt;
 102
 103         if (suser(kauth_cred_get(), 0) != 0 )
 104                 return(EPERM);
 105
 106         /*
 107          * Set up state prior to starting kernel process so we can back out
 108          *  (error return) if something goes wrong.
 109          */
 110         bzero((char *)&aurp_global.tunnel, sizeof(aurp_global.tunnel));
 111         /*lock_alloc(&aurp_global.glock, LOCK_ALLOC_PIN, AURP_EVNT_LOCK, -1);*/
 112         ATLOCKINIT(aurp_global.glock);
 113         ATEVENTINIT(aurp_global.event_anchor);
 114
 115         /* open udp socket */
 116         if (aurp_global.udp_port == 0)
 117                 aurp_global.udp_port = AURP_SOCKNUM;
 118         error = socreate(AF_INET, &aurp_global.tunnel, SOCK_DGRAM,
 119                          IPPROTO_UDP);
 120         if (error)
 121         {       dPrintf(D_M_AURP, D_L_FATAL, ("AURP: Can't get socket (%d)\n",
 122                         error));
 123                 return(error);
 124         }
 125
 126         so = aurp_global.tunnel;
 127
 128         if ((error = aurp_bindrp(so)) != 0)
 129         {       dPrintf(D_M_AURP, D_L_FATAL,
 130                         ("AURP: Can't bind to port %d (error %d)\n",
 131                         aurp_global.udp_port, error));
 132                 soclose(so);
 133                 return(error);
 134         }
 135
 136         sblock(&so->so_rcv, M_WAIT);
 137         sblock(&so->so_snd, M_WAIT);
 138
 139         /*
 140          * Set socket Receive buffer size
 141          */
 142         m = m_get(M_WAIT, MT_SOOPTS);
 143         if (m == NULL) {
 144                 error = ENOBUFS;
 145                 goto out;
 146         } else {
 147                 maxbuf = M_RCVBUF;
 148                 sopt.sopt_val     = CAST_USER_ADDR_T(&maxbuf);
 149                 sopt.sopt_valsize = sizeof(maxbuf);
 150                 sopt.sopt_level   = SOL_SOCKET;
 151                 sopt.sopt_name    = SO_RCVBUF;
 152                 sopt.sopt_dir     = SOPT_SET;
 153                 sopt.sopt_p               = NULL;
 154                 if ((error = sosetopt(so, &sopt)) != 0)
 155                         goto out;
 156         }
 157
 158         /*
 159          * Set socket Send buffer size
 160          */
 161         m = m_get(M_WAIT, MT_SOOPTS);
 162         if (m == NULL) {
 163                 error = ENOBUFS;
 164                 goto out;
 165         } else {
 166
 167                 maxbuf = M_SNDBUF;
 168                 sopt.sopt_val     = CAST_USER_ADDR_T(&maxbuf);
 169                 sopt.sopt_valsize = sizeof(maxbuf);
 170                 sopt.sopt_level   = SOL_SOCKET;
 171                 sopt.sopt_name    = SO_SNDBUF;
 172                 sopt.sopt_dir     = SOPT_SET;
 173                 sopt.sopt_p               = NULL;
 174                 if ((error = sosetopt(so, &sopt)) != 0)
 175                         goto out;
 176         }
 177
 178         so->so_upcall = aurp_wakeup;
 179         so->so_upcallarg = (caddr_t)AE_UDPIP; /* Yuck */
 180         so->so_state |= SS_NBIO;
 181         so->so_rcv.sb_flags |=(SB_SEL|SB_NOINTR);
 182         so->so_snd.sb_flags |=(SB_SEL|SB_NOINTR);
 183
 184 out:
 185         sbunlock(&so->so_snd, 0);
 186         sbunlock(&so->so_rcv, 0);
 187
 188         return(error);
 189 }
 190
 191 int
 192 AURPgetmsg(err)
 193         int *err;
 194 {       register struct socket *so;
 195         register int events;
 196
 197         so = aurp_global.tunnel;
 198         *err = 0;
 199
 200         for (;;)
 201         {       gbuf_t *from, *p_mbuf;
 202                 int flags = MSG_DONTWAIT;
 203                 uio_t auio;
 204                 char uio_buf[ UIO_SIZEOF(0) ];
 205
 206                 /*
 207                  * Wait for a package to arrive.  This will be from the
 208                  * IP side - sowakeup() calls aurp_wakeup()
 209                  *           when a packet arrives
 210                  */
 211
 212                 ATDISABLE(s, aurp_global.glock);
 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                 ATENABLE(s, aurp_global.glock);
 222
 223                 /*
 224                  * Shut down if we have the AE_SHUTDOWN event or if we got
 225                  * a system error other than EWOULDBLOCK, such as EINTR.
 226                  */
 227                 if (((*err != EWOULDBLOCK) && (*err != 0)) || events & AE_SHUTDOWN)
 228                   {
 229                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 230                         ("AURPgetmsg: AE_SHUTDOWN detected--starting shutdown sequence\n"));
 231                     aurp_global.shutdown = 1;
 232                     while (aurp_global.running)
 233                         ;
 234                     /*lock_free(&aurp_global.glock);*/
 235                     aurp_global.tunnel = 0;
 236                     aurp_global.event = 0;
 237                     aurp_global.shutdown = 0;
 238                     soclose(so);
 239                     if (*err == 0)
 240                     *err = ESHUTDOWN;
 241                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 242                         ("AURPgetmsg: shutdown completed\n"));
 243                     return -1;
 244                   }
 245
 246
 247
 248                 /*
 249                  * Set up the nominal uio structure -
 250                  *  give it no iov's, point off to non-existant user space,
 251                  *  but make sure the 'resid' count means somehting.
 252                  */
 253                 auio = uio_createwithbuffer(0, 0, UIO_SYSSPACE, UIO_READ,
 254                                                                   &uio_buf[0], sizeof(uio_buf));
 255
 256                 /* Keep up an even flow... */
 257                 for (;;)
 258                 {
 259 /*
 260  * This should be large enough to encompass a full DDP packet plus
 261  *  domain header.
 262  */
 263 #define A_LARGE_SIZE 700
 264
 265                         flags = MSG_DONTWAIT;
 266                         uio_setresid(auio, A_LARGE_SIZE);
 267                         *err = soreceive(so, (struct sockaddr **)&from, auio, &p_mbuf, 0, &flags);
 268                         dPrintf(D_M_AURP, D_L_VERBOSE,
 269                                 ("AURPgetmsg: soreceive returned %d, aurp_global.event==0x%x\n", *err, events));
 270                         /* soreceive() sets *mp to zero! at start */
 271                         if (p_mbuf)
 272                                 ip_to_atalk((struct sockaddr_in *)from, p_mbuf);
 273                         if (*err || (p_mbuf == NULL)) {
 274                                 /*
 275                                  * An error occurred in soreceive(),
 276                                  * so clear the data input event flag
 277                                  * and break out of this inner loop.
 278                                  *
 279                                  * XXX Note that clearing AE_UDPIP here could
 280                                  * cause us to lose an AE_UDPIP event that
 281                                  * was posted in aurp_global.event between
 282                                  * the soreceive() above and the code here.
 283                                  * The protocol should recover from this
 284                                  * lost event, though, since the next
 285                                  * request (a tickle, for example) from
 286                                  * the other end of the tunnel will cause
 287                                  * another AE_UDPIP event to be posted,
 288                                  * which will wake us from the sleep at
 289                                  * the top of the outer loop.
 290                                  */
 291                                 ATDISABLE(s, aurp_global.glock);
 292                                 aurp_global.event &= ~AE_UDPIP;
 293                                 ATENABLE(s, aurp_global.glock);
 294                                 dPrintf(D_M_AURP, D_L_WARNING, ("AURPgetmsg: spurious soreceive, err==%d, p_mbuf==0x%x\n", *err, (unsigned int) p_mbuf));
 295                           break;
 296                 }
 297         }
 298         }
 299         return -1;
 300 }
 301
 302 /*
 303  * Wakeup the sleeping giant - we've put a message on his queue(s).
 304  * The arg indicates what queue has been updated.
 305  *
 306  * This conforms to the so_upcall function pointer member of struct sockbuf.
 307  */
 308 void aurp_wakeup(__unused struct socket *so, register caddr_t p, __unused int state)
 309 {
 310         register int bit;
 311
 312         bit = (int) p;
 313         ATDISABLE(s, aurp_global.glock);
 314         aurp_global.event |= bit;
 315         ATENABLE(s, aurp_global.glock);
 316
 317         dPrintf(D_M_AURP, D_L_STATE_CHG,
 318                 ("aurp_wakeup: bit 0x%x, aurp_global.event now 0x%x\n",
 319                 bit, aurp_global.event));
 320
 321         wakeup(&aurp_global.event_anchor);
 322 }
 323
 324 /*
 325  * Try to bind to the specified reserved port.
 326  * Sort of like sobind(), but no suser() check.
 327  */
 328 static int
 329 aurp_bindrp(struct socket *so)
 330 {
 331         struct sockaddr_in sin;
 332         struct proc *p = current_proc();
 333         int error;
 334
 335
 336         bzero(&sin, sizeof(sin));
 337         sin.sin_family      = AF_INET;
 338         sin.sin_addr.s_addr = htons(aurp_global.src_addr);
 339         sin.sin_port        = htons(aurp_global.udp_port);
 340         sin.sin_len         = sizeof(struct sockaddr_in);
 341
 342         sblock(&so->so_rcv, M_WAIT);
 343         sblock(&so->so_snd, M_WAIT);
 344         so->so_state |= SS_PRIV;
 345         error = (*so->so_proto->pr_usrreqs->pru_bind)(so, (struct sockaddr *) &sin, p);
 346         sbunlock(&so->so_snd, 0);
 347         sbunlock(&so->so_rcv, 0);
 348
 349         return (error);
 350 }
 351
 352 /*
 353  * receive from UDP
 354  * fp is the 'source address' mbuf; p_mbuf is the data mbuf.
 355  * Use the source address to find the 'node number' (index of the address),
 356  *  and pass that to the next stage.
 357  */
 358 int ip_to_atalk(register struct sockaddr_in *rem_addr, register gbuf_t *p_mbuf)
 359 {
 360         register aurp_domain_t *domain;
 361         unsigned char node;
 362
 363
 364         /* determine the node where the packet came from */
 365         for (node=1; node <= dst_addr_cnt; node++) {
 366                 if (aurp_global.dst_addr[node] == *(long *)&rem_addr->sin_addr)
 367                         break;
 368         }
 369         if (node > dst_addr_cnt) {
 370                 dPrintf(D_M_AURP, D_L_WARNING,
 371                         ("AURPrecv: invalid node, %d.%lx\n",
 372                         rem_addr->sin_port,
 373                         rem_addr->sin_addr.s_addr));
 374
 375                 gbuf_freem(p_mbuf);
 376                 FREE(rem_addr, M_SONAME);
 377                 return -1;
 378         }
 379
 380         /* validate the domain */
 381         domain = (aurp_domain_t *)gbuf_rptr(p_mbuf);
 382         if ( (domain->dst_length != IP_LENGTH) ||
 383             (domain->dst_authority != IP_AUTHORITY) ||
 384             (domain->version != AUD_Version) ||
 385             ((domain->type != AUD_Atalk) && (domain->type != AUD_AURP)) ) {
 386                 dPrintf(D_M_AURP, D_L_WARNING,
 387                         ("AURPrecv: invalid domain, %d.%lx\n",
 388                         rem_addr->sin_port,
 389                         rem_addr->sin_addr.s_addr));
 390
 391                 gbuf_freem(p_mbuf);
 392                 FREE(rem_addr, M_SONAME);
 393                 return -1;
 394         }
 395
 396         /* Remove domain header */
 397         p_mbuf->m_pkthdr.len -= IP_DOMAINSIZE;
 398         gbuf_rinc(p_mbuf,IP_DOMAINSIZE);
 399         gbuf_set_type(p_mbuf, MSG_DATA);
 400
 401         /* forward the packet to the local AppleTalk stack */
 402
 403         at_insert(p_mbuf, domain->type, node);
 404         FREE(rem_addr, M_SONAME);
 405         return 0;
 406 }
 407
 408 /*
 409  * send to UDP
 410  * The real work has been done already.  Here, we just cobble together
 411  *  a sockaddr for the destination and call sosend().
 412  */
 413 void
 414 atalk_to_ip(register gbuf_t *m)
 415 {       register aurp_domain_t *domain;
 416         int error;
 417         int flags = MSG_DONTWAIT;
 418         struct sockaddr_in rem_addr;
 419
 420         m->m_type = MT_HEADER;
 421         m->m_pkthdr.len = gbuf_msgsize(m);
 422         m->m_pkthdr.rcvif = 0;
 423
 424         bzero((char *) &rem_addr, sizeof(rem_addr));
 425         rem_addr.sin_family = PF_INET;
 426         rem_addr.sin_port = aurp_global.udp_port;
 427         rem_addr.sin_len  = sizeof (struct sockaddr_in);
 428         domain = (aurp_domain_t *)gbuf_rptr(m);
 429         *(long *) &rem_addr.sin_addr = domain->dst_address;
 430
 431         ATDISABLE(s, aurp_global.glock);
 432         aurp_global.running++;
 433         ATENABLE(s, aurp_global.glock);
 434         if (aurp_global.shutdown) {
 435                 gbuf_freem(m);
 436                         ATDISABLE(s, aurp_global.glock);
 437                 aurp_global.running--;
 438                 ATENABLE(s, aurp_global.glock);
 439                 dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 440                         ("atalk_to_ip: detected aurp_global.shutdown state\n"));
 441                 return;
 442         }
 443         dPrintf(D_M_AURP, D_L_VERBOSE, ("atalk_to_ip: calling sosend\n"));
 444         error = sosend(aurp_global.tunnel, (struct sockaddr *) &rem_addr, NULL, m, NULL, flags);
 445         if (error)
 446         {       /*log error*/
 447           dPrintf(D_M_AURP, D_L_ERROR, ("AURP: sosend error (%d)\n",
 448                   error));
 449         }
 450
 451         ATDISABLE(s, aurp_global.glock);
 452         aurp_global.running--;
 453         ATENABLE(s, aurp_global.glock);
 454         return;
 455 }
 456