bsd/netat/aurp_aurpd.c

   1 /*
   2  * Copyright (c) 2000-2004 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/kauth.h>
  44 #include <sys/filedesc.h>
  45 #include <sys/fcntl.h>
  46 #include <sys/mbuf.h>
  47 #include <sys/socket.h>
  48 #include <sys/socketvar.h>
  49 #include <sys/protosw.h>
  50 #include <sys/malloc.h>
  51 #include <sys/proc.h>
  52 #include <sys/uio_internal.h>
  53 #include <kern/locks.h>
  54 #include <netinet/in.h>
  55 #include <net/if.h>
  56
  57 #include <netat/sysglue.h>
  58 #include <netat/appletalk.h>
  59 #include <netat/at_var.h>
  60 #include <netat/routing_tables.h>
  61 #include <netat/at_pcb.h>
  62 #include <netat/aurp.h>
  63 #include <netat/debug.h>
  64
  65 #define M_RCVBUF (64 * 1024)
  66 #define M_SNDBUF (64 * 1024)
  67
  68 extern lck_mtx_t * atalk_mutex;
  69
  70 static int ip_to_atalk(struct sockaddr_in *fp, register gbuf_t *p_mbuf);
  71 static int aurp_bindrp(struct socket *so);
  72
  73 struct aurp_global_t aurp_global;
  74
  75 /*
  76  * Initialize the aurp pipe -
  77  * -Create, initialize, and start the aurpd kernel process; we need
  78  *  a process to permit queueing between the socket and the stream,
  79  *  which is necessary for orderly access to the socket structure.
  80  * -The user process (aurpd) is there to 'build' the AURP
  81  *  stream, act as a 'logging agent' (:-}), and hold open the stream
  82  *  during its use.
  83  * -Data and AURP packets from the DDP stream will be fed into the
  84  *  UDP tunnel (AURPsend())
  85  * -Data and AURP packets from the UDP tunnel will be fed into the
  86  *  DDP stream (ip_to_atalk(), via the kernel process).
  87  */
  88 int
  89 aurpd_start()
  90 {
  91         register int error;
  92         register struct socket *so;
  93         struct mbuf *m;
  94         int maxbuf;
  95         struct sockopt sopt;
  96
  97         if (suser(kauth_cred_get(), 0) != 0 )
  98                 return(EPERM);
  99
 100         /*
 101          * Set up state prior to starting kernel process so we can back out
 102          *  (error return) if something goes wrong.
 103          */
 104         bzero((char *)&aurp_global.tunnel, sizeof(aurp_global.tunnel));
 105         /*lock_alloc(&aurp_global.glock, LOCK_ALLOC_PIN, AURP_EVNT_LOCK, -1);*/
 106         ATLOCKINIT(aurp_global.glock);
 107         ATEVENTINIT(aurp_global.event_anchor);
 108
 109         /* open udp socket */
 110         if (aurp_global.udp_port == 0)
 111                 aurp_global.udp_port = AURP_SOCKNUM;
 112         error = socreate(AF_INET, &aurp_global.tunnel, SOCK_DGRAM,
 113                          IPPROTO_UDP);
 114         if (error)
 115         {       dPrintf(D_M_AURP, D_L_FATAL, ("AURP: Can't get socket (%d)\n",
 116                         error));
 117                 return(error);
 118         }
 119
 120         so = aurp_global.tunnel;
 121
 122         if ((error = aurp_bindrp(so)) != 0)
 123         {       dPrintf(D_M_AURP, D_L_FATAL,
 124                         ("AURP: Can't bind to port %d (error %d)\n",
 125                         aurp_global.udp_port, error));
 126                 soclose(so);
 127                 return(error);
 128         }
 129
 130         sblock(&so->so_rcv, M_WAIT);
 131         sblock(&so->so_snd, M_WAIT);
 132
 133         /*
 134          * Set socket Receive buffer size
 135          */
 136         m = m_get(M_WAIT, MT_SOOPTS);
 137         if (m == NULL) {
 138                 error = ENOBUFS;
 139                 goto out;
 140         } else {
 141                 maxbuf = M_RCVBUF;
 142                 sopt.sopt_val     = CAST_USER_ADDR_T(&maxbuf);
 143                 sopt.sopt_valsize = sizeof(maxbuf);
 144                 sopt.sopt_level   = SOL_SOCKET;
 145                 sopt.sopt_name    = SO_RCVBUF;
 146                 sopt.sopt_dir     = SOPT_SET;
 147                 sopt.sopt_p               = NULL;
 148                 if ((error = sosetopt(so, &sopt)) != 0)
 149                         goto out;
 150         }
 151
 152         /*
 153          * Set socket Send buffer size
 154          */
 155         m = m_get(M_WAIT, MT_SOOPTS);
 156         if (m == NULL) {
 157                 error = ENOBUFS;
 158                 goto out;
 159         } else {
 160
 161                 maxbuf = M_SNDBUF;
 162                 sopt.sopt_val     = CAST_USER_ADDR_T(&maxbuf);
 163                 sopt.sopt_valsize = sizeof(maxbuf);
 164                 sopt.sopt_level   = SOL_SOCKET;
 165                 sopt.sopt_name    = SO_SNDBUF;
 166                 sopt.sopt_dir     = SOPT_SET;
 167                 sopt.sopt_p               = NULL;
 168                 if ((error = sosetopt(so, &sopt)) != 0)
 169                         goto out;
 170         }
 171
 172         so->so_upcall = aurp_wakeup;
 173         so->so_upcallarg = (caddr_t)AE_UDPIP; /* Yuck */
 174         so->so_state |= SS_NBIO;
 175         so->so_rcv.sb_flags |=(SB_SEL|SB_NOINTR);
 176         so->so_snd.sb_flags |=(SB_SEL|SB_NOINTR);
 177
 178 out:
 179         sbunlock(&so->so_snd, 0);
 180         sbunlock(&so->so_rcv, 0);
 181
 182         return(error);
 183 }
 184
 185 int
 186 AURPgetmsg(err)
 187         int *err;
 188 {       register struct socket *so;
 189         register int events;
 190
 191         so = aurp_global.tunnel;
 192         *err = 0;
 193
 194         for (;;)
 195         {       gbuf_t *from, *p_mbuf;
 196                 int flags = MSG_DONTWAIT;
 197                 uio_t auio;
 198                 char uio_buf[ UIO_SIZEOF(0) ];
 199
 200                 /*
 201                  * Wait for a package to arrive.  This will be from the
 202                  * IP side - sowakeup() calls aurp_wakeup()
 203                  *           when a packet arrives
 204                  */
 205
 206                 ATDISABLE(s, aurp_global.glock);
 207                 events = aurp_global.event;
 208                 if (((*err == 0) || (*err == EWOULDBLOCK)) && events == 0)
 209                   {
 210                         lck_mtx_assert(atalk_mutex, LCK_MTX_ASSERT_OWNED);
 211                     *err = msleep(&aurp_global.event_anchor, atalk_mutex, PSOCK | PCATCH, "AURPgetmsg", 0);
 212                     events = aurp_global.event;
 213                     aurp_global.event = 0;
 214                   }
 215                 ATENABLE(s, aurp_global.glock);
 216
 217                 /*
 218                  * Shut down if we have the AE_SHUTDOWN event or if we got
 219                  * a system error other than EWOULDBLOCK, such as EINTR.
 220                  */
 221                 if (((*err != EWOULDBLOCK) && (*err != 0)) || events & AE_SHUTDOWN)
 222                   {
 223                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 224                         ("AURPgetmsg: AE_SHUTDOWN detected--starting shutdown sequence\n"));
 225                     aurp_global.shutdown = 1;
 226                     while (aurp_global.running)
 227                         ;
 228                     /*lock_free(&aurp_global.glock);*/
 229                     aurp_global.tunnel = 0;
 230                     aurp_global.event = 0;
 231                     aurp_global.shutdown = 0;
 232                     soclose(so);
 233                     if (*err == 0)
 234                     *err = ESHUTDOWN;
 235                     dPrintf(D_M_AURP, D_L_SHUTDN_INFO,
 236                         ("AURPgetmsg: shutdown completed\n"));
 237                     return -1;
 238                   }
 239
 240
 241
 242                 /*
 243                  * Set up the nominal uio structure -
 244                  *  give it no iov's, point off to non-existant user space,
 245                  *  but make sure the 'resid' count means somehting.
 246                  */
 247                 auio = uio_createwithbuffer(0, 0, UIO_SYSSPACE, UIO_READ,
 248                                                                   &uio_buf[0], sizeof(uio_buf));
 249
 250                 /* Keep up an even flow... */
 251                 for (;;)
 252                 {
 253 /*
 254  * This should be large enough to encompass a full DDP packet plus
 255  *  domain header.
 256  */
 257 #define A_LARGE_SIZE 700
 258
 259                         flags = MSG_DONTWAIT;
 260                         uio_setresid(auio, A_LARGE_SIZE);
 261                         *err = soreceive(so, (struct sockaddr **)&from, auio, &p_mbuf, 0, &flags);
 262                         dPrintf(D_M_AURP, D_L_VERBOSE,
 263                                 ("AURPgetmsg: soreceive returned %d, aurp_global.event==0x%x\n", *err, events));
 264                         /* soreceive() sets *mp to zero! at start */
 265                         if (p_mbuf)
 266                                 ip_to_atalk((struct sockaddr_in *)from, p_mbuf);
 267                         if (*err || (p_mbuf == NULL)) {
 268                                 /*
 269                                  * An error occurred in soreceive(),
 270                                  * so clear the data input event flag
 271                                  * and break out of this inner loop.
 272                                  *
 273                                  * XXX Note that clearing AE_UDPIP here could
 274                                  * cause us to lose an AE_UDPIP event that
 275                                  * was posted in aurp_global.event between
 276                                  * the soreceive() above and the code here.
 277                                  * The protocol should recover from this
 278                                  * lost event, though, since the next
 279                                  * request (a tickle, for example) from
 280                                  * the other end of the tunnel will cause
 281                                  * another AE_UDPIP event to be posted,
 282                                  * which will wake us from the sleep at
 283                                  * the top of the outer loop.
 284                                  */
 285                                 ATDISABLE(s, aurp_global.glock);
 286                                 aurp_global.event &= ~AE_UDPIP;
 287                                 ATENABLE(s, aurp_global.glock);
 288                                 dPrintf(D_M_AURP, D_L_WARNING, ("AURPgetmsg: spurious soreceive, err==%d, p_mbuf==0x%x\n", *err, (unsigned int) p_mbuf));
 289                           break;
 290                 }
 291         }
 292         }
 293         return -1;
 294 }
 295
 296 /*
 297  * Wakeup the sleeping giant - we've put a message on his queue(s).
 298  * The arg indicates what queue has been updated.
 299  *
 300  * This conforms to the so_upcall function pointer member of struct sockbuf.
 301  */
 302 void aurp_wakeup(__unused struct socket *so, register caddr_t p, __unused int state)
 303 {
 304         register int bit;
 305
 306         bit = (int) p;
 307         ATDISABLE(s, aurp_global.glock);
 308         aurp_global.event |= bit;
 309         ATENABLE(s, aurp_global.glock);
 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         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