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_var.h>
  67 #include <netat/routing_tables.h>
  68 #include <netat/at_pcb.h>
  69 #include <netat/aurp.h>
  70 #include <netat/debug.h>
  71
  72 #define M_RCVBUF (64 * 1024)
  73 #define M_SNDBUF (64 * 1024)
  74
  75 extern lck_mtx_t * atalk_mutex;
  76
  77 static int ip_to_atalk(struct sockaddr_in *fp, register gbuf_t *p_mbuf);
  78 static int aurp_bindrp(struct socket *so);
  79
  80 struct aurp_global_t aurp_global;
  81
  82 /*
  83  * Initialize the aurp pipe -
  84  * -Create, initialize, and start the aurpd kernel process; we need
  85  *  a process to permit queueing between the socket and the stream,
  86  *  which is necessary for orderly access to the socket structure.
  87  * -The user process (aurpd) is there to 'build' the AURP
  88  *  stream, act as a 'logging agent' (:-}), and hold open the stream
  89  *  during its use.
  90  * -Data and AURP packets from the DDP stream will be fed into the
  91  *  UDP tunnel (AURPsend())
  92  * -Data and AURP packets from the UDP tunnel will be fed into the
  93  *  DDP stream (ip_to_atalk(), via the kernel process).
  94  */
  95 int
  96 aurpd_start()
  97 {
  98         register int error;
  99         register struct socket *so;
 100         struct mbuf *m;
 101         int maxbuf;
 102         struct sockopt sopt;
 103
 104         if (suser(kauth_cred_get(), 0) != 0 )
 105                 return(EPERM);
 106
 107         /*
 108          * Set up state prior to starting kernel process so we can back out
 109          *  (error return) if something goes wrong.
 110          */
 111         bzero((char *)&aurp_global.tunnel, sizeof(aurp_global.tunnel));
 112         /*lock_alloc(&aurp_global.glock, LOCK_ALLOC_PIN, AURP_EVNT_LOCK, -1);*/
 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                 events = aurp_global.event;
 213                 if (((*err == 0) || (*err == EWOULDBLOCK)) && events == 0)
 214                   {
 215                         lck_mtx_assert(atalk_mutex, LCK_MTX_ASSERT_OWNED);
 216                     *err = msleep(&aurp_global.event_anchor, atalk_mutex, PSOCK | PCATCH, "AURPgetmsg", 0);
 217                     events = aurp_global.event;
 218                     aurp_global.event = 0;
 219                   }
 220
 221                 /*
 222                  * Shut down if we have the AE_SHUTDOWN event or if we got
 223                  * a system error other than EWOULDBLOCK, such as EINTR.
 224                  */
 225                 if (((*err != EWOULDBLOCK) && (*err != 0)) || events & AE_SHUTDOWN)
 226                   {
 227                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 228                         ("AURPgetmsg: AE_SHUTDOWN detected--starting shutdown sequence\n"));
 229                     aurp_global.shutdown = 1;
 230                     while (aurp_global.running)
 231                         ;
 232                     /*lock_free(&aurp_global.glock);*/
 233                     aurp_global.tunnel = 0;
 234                     aurp_global.event = 0;
 235                     aurp_global.shutdown = 0;
 236                     soclose(so);
 237                     if (*err == 0)
 238                     *err = ESHUTDOWN;
 239                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 240                         ("AURPgetmsg: shutdown completed\n"));
 241                     return -1;
 242                   }
 243
 244
 245
 246                 /*
 247                  * Set up the nominal uio structure -
 248                  *  give it no iov's, point off to non-existant user space,
 249                  *  but make sure the 'resid' count means somehting.
 250                  */
 251                 auio = uio_createwithbuffer(0, 0, UIO_SYSSPACE, UIO_READ,
 252                                                                   &uio_buf[0], sizeof(uio_buf));
 253
 254                 /* Keep up an even flow... */
 255                 for (;;)
 256                 {
 257 /*
 258  * This should be large enough to encompass a full DDP packet plus
 259  *  domain header.
 260  */
 261 #define A_LARGE_SIZE 700
 262
 263                         flags = MSG_DONTWAIT;
 264                         uio_setresid(auio, A_LARGE_SIZE);
 265                         *err = soreceive(so, (struct sockaddr **)&from, auio, &p_mbuf, 0, &flags);
 266                         dPrintf(D_M_AURP, D_L_VERBOSE,
 267                                 ("AURPgetmsg: soreceive returned %d, aurp_global.event==0x%x\n", *err, events));
 268                         /* soreceive() sets *mp to zero! at start */
 269                         if (p_mbuf)
 270                                 ip_to_atalk((struct sockaddr_in *)from, p_mbuf);
 271                         if (*err || (p_mbuf == NULL)) {
 272                                 /*
 273                                  * An error occurred in soreceive(),
 274                                  * so clear the data input event flag
 275                                  * and break out of this inner loop.
 276                                  *
 277                                  * XXX Note that clearing AE_UDPIP here could
 278                                  * cause us to lose an AE_UDPIP event that
 279                                  * was posted in aurp_global.event between
 280                                  * the soreceive() above and the code here.
 281                                  * The protocol should recover from this
 282                                  * lost event, though, since the next
 283                                  * request (a tickle, for example) from
 284                                  * the other end of the tunnel will cause
 285                                  * another AE_UDPIP event to be posted,
 286                                  * which will wake us from the sleep at
 287                                  * the top of the outer loop.
 288                                  */
 289                                 aurp_global.event &= ~AE_UDPIP;
 290                                 dPrintf(D_M_AURP, D_L_WARNING, ("AURPgetmsg: spurious soreceive, err==%d, p_mbuf==0x%x\n", *err, (unsigned int) p_mbuf));
 291                           break;
 292                 }
 293         }
 294         }
 295         return -1;
 296 }
 297
 298 /*
 299  * Wakeup the sleeping giant - we've put a message on his queue(s).
 300  * The arg indicates what queue has been updated.
 301  *
 302  * This conforms to the so_upcall function pointer member of struct sockbuf.
 303  */
 304 void aurp_wakeup(__unused struct socket *so, register caddr_t p, __unused int state)
 305 {
 306         register int bit;
 307
 308         bit = (int) p;
 309         aurp_global.event |= bit;
 310
 311         dPrintf(D_M_AURP, D_L_STATE_CHG,
 312                 ("aurp_wakeup: bit 0x%x, aurp_global.event now 0x%x\n",
 313                 bit, aurp_global.event));
 314
 315         wakeup(&aurp_global.event_anchor);
 316 }
 317
 318 /*
 319  * Try to bind to the specified reserved port.
 320  * Sort of like sobind(), but no suser() check.
 321  */
 322 static int
 323 aurp_bindrp(struct socket *so)
 324 {
 325         struct sockaddr_in sin;
 326         struct proc *p = current_proc();
 327         int error;
 328
 329
 330         bzero(&sin, sizeof(sin));
 331         sin.sin_family      = AF_INET;
 332         sin.sin_addr.s_addr = htons(aurp_global.src_addr);
 333         sin.sin_port        = htons(aurp_global.udp_port);
 334         sin.sin_len         = sizeof(struct sockaddr_in);
 335
 336         sblock(&so->so_rcv, M_WAIT);
 337         sblock(&so->so_snd, M_WAIT);
 338         so->so_state |= SS_PRIV;
 339         error = (*so->so_proto->pr_usrreqs->pru_bind)(so, (struct sockaddr *) &sin, p);
 340         sbunlock(&so->so_snd, 0);
 341         sbunlock(&so->so_rcv, 0);
 342
 343         return (error);
 344 }
 345
 346 /*
 347  * receive from UDP
 348  * fp is the 'source address' mbuf; p_mbuf is the data mbuf.
 349  * Use the source address to find the 'node number' (index of the address),
 350  *  and pass that to the next stage.
 351  */
 352 int ip_to_atalk(register struct sockaddr_in *rem_addr, register gbuf_t *p_mbuf)
 353 {
 354         register aurp_domain_t *domain;
 355         unsigned char node;
 356
 357
 358         /* determine the node where the packet came from */
 359         for (node=1; node <= dst_addr_cnt; node++) {
 360                 if (aurp_global.dst_addr[node] == *(long *)&rem_addr->sin_addr)
 361                         break;
 362         }
 363         if (node > dst_addr_cnt) {
 364                 dPrintf(D_M_AURP, D_L_WARNING,
 365                         ("AURPrecv: invalid node, %d.%lx\n",
 366                         rem_addr->sin_port,
 367                         rem_addr->sin_addr.s_addr));
 368
 369                 gbuf_freem(p_mbuf);
 370                 FREE(rem_addr, M_SONAME);
 371                 return -1;
 372         }
 373
 374         /* validate the domain */
 375         domain = (aurp_domain_t *)gbuf_rptr(p_mbuf);
 376         if ( (domain->dst_length != IP_LENGTH) ||
 377             (domain->dst_authority != IP_AUTHORITY) ||
 378             (domain->version != AUD_Version) ||
 379             ((domain->type != AUD_Atalk) && (domain->type != AUD_AURP)) ) {
 380                 dPrintf(D_M_AURP, D_L_WARNING,
 381                         ("AURPrecv: invalid domain, %d.%lx\n",
 382                         rem_addr->sin_port,
 383                         rem_addr->sin_addr.s_addr));
 384
 385                 gbuf_freem(p_mbuf);
 386                 FREE(rem_addr, M_SONAME);
 387                 return -1;
 388         }
 389
 390         /* Remove domain header */
 391         p_mbuf->m_pkthdr.len -= IP_DOMAINSIZE;
 392         gbuf_rinc(p_mbuf,IP_DOMAINSIZE);
 393         gbuf_set_type(p_mbuf, MSG_DATA);
 394
 395         /* forward the packet to the local AppleTalk stack */
 396
 397         at_insert(p_mbuf, domain->type, node);
 398         FREE(rem_addr, M_SONAME);
 399         return 0;
 400 }
 401
 402 /*
 403  * send to UDP
 404  * The real work has been done already.  Here, we just cobble together
 405  *  a sockaddr for the destination and call sosend().
 406  */
 407 void
 408 atalk_to_ip(register gbuf_t *m)
 409 {       register aurp_domain_t *domain;
 410         int error;
 411         int flags = MSG_DONTWAIT;
 412         struct sockaddr_in rem_addr;
 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         aurp_global.running++;
 426         if (aurp_global.shutdown) {
 427                 gbuf_freem(m);
 428                 aurp_global.running--;
 429                 dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 430                         ("atalk_to_ip: detected aurp_global.shutdown state\n"));
 431                 return;
 432         }
 433         dPrintf(D_M_AURP, D_L_VERBOSE, ("atalk_to_ip: calling sosend\n"));
 434         error = sosend(aurp_global.tunnel, (struct sockaddr *) &rem_addr, NULL, m, NULL, flags);
 435         if (error)
 436         {       /*log error*/
 437           dPrintf(D_M_AURP, D_L_ERROR, ("AURP: sosend error (%d)\n",
 438                   error));
 439         }
 440
 441         aurp_global.running--;
 442         return;
 443 }
 444
 445 #endif  /* AURP_SUPPORT */