sys/netproto/ncp/ncp_conn.c

   1 /*
   2  * Copyright (c) 1999, Boris Popov
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *    This product includes software developed by Boris Popov.
  16  * 4. Neither the name of the author nor the names of any co-contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  * $FreeBSD: src/sys/netncp/ncp_conn.c,v 1.3.2.5 2001/02/22 08:54:11 bp Exp $
  32  * $DragonFly: src/sys/netproto/ncp/ncp_conn.c,v 1.15 2007/05/13 18:33:58 swildner Exp $
  33  *
  34  * Connection tables
  35  */
  36 #include <sys/param.h>
  37 #include <sys/systm.h>
  38 #include <sys/kernel.h>
  39 #include <sys/malloc.h>
  40 #include <sys/proc.h>
  41 #include <sys/lock.h>
  42 #include <sys/sysctl.h>
  43
  44 #include "ncp.h"
  45 #include "ncp_subr.h"
  46 #include "ncp_conn.h"
  47
  48 SLIST_HEAD(ncp_handle_head,ncp_handle);
  49
  50 int ncp_burst_enabled = 1;
  51
  52 struct ncp_conn_head conn_list={NULL};
  53 static int ncp_conn_cnt = 0;
  54 static int ncp_next_ref = 1;
  55 static struct lock listlock;
  56
  57 struct ncp_handle_head lhlist={NULL};
  58 static int ncp_next_handle = 1;
  59 static struct lock lhlock;
  60
  61 static int ncp_sysctl_connstat(SYSCTL_HANDLER_ARGS);
  62 static int ncp_conn_lock_any(struct ncp_conn *conn, struct thread *td,
  63     struct ucred *cred);
  64
  65 SYSCTL_DECL(_net_ncp);
  66 SYSCTL_INT (_net_ncp, OID_AUTO, burst_enabled, CTLFLAG_RD, &ncp_burst_enabled, 0, "");
  67 SYSCTL_INT (_net_ncp, OID_AUTO, conn_cnt, CTLFLAG_RD, &ncp_conn_cnt, 0, "");
  68 SYSCTL_PROC(_net_ncp, OID_AUTO, conn_stat, CTLFLAG_RD|CTLTYPE_OPAQUE,
  69             NULL, 0, ncp_sysctl_connstat, "S,connstat", "Connections list");
  70
  71 MALLOC_DEFINE(M_NCPDATA, "NCP data", "NCP private data");
  72
  73 int
  74 ncp_conn_init(void) {
  75         lockinit(&listlock, "ncpll", 0, 0);
  76         lockinit(&lhlock, "ncplh", 0, 0);
  77         return 0;
  78 }
  79
  80 int
  81 ncp_conn_locklist(int flags, struct thread *td)
  82 {
  83         return lockmgr(&listlock, flags | LK_CANRECURSE);
  84 }
  85
  86 void
  87 ncp_conn_unlocklist(struct thread *td)
  88 {
  89         lockmgr(&listlock, LK_RELEASE);
  90 }
  91
  92 int
  93 ncp_conn_access(struct ncp_conn *conn, struct ucred *cred, mode_t mode)
  94 {
  95         int error;
  96
  97         if (cred == NOCRED || ncp_suser(cred) == 0 ||
  98             cred->cr_uid == conn->nc_owner->cr_uid)
  99                 return 0;
 100         mode >>= 3;
 101         if (!groupmember(conn->nc_group, cred))
 102                 mode >>= 3;
 103         error = (conn->li.access_mode & mode) == mode ? 0 : EACCES;
 104         return error;
 105 }
 106
 107 /*
 108  * NOTE: The lockmgr() call is protected by nc_lwant
 109  */
 110 int
 111 ncp_conn_lock_any(struct ncp_conn *conn, struct thread *td, struct ucred *cred)
 112 {
 113         int error;
 114
 115         if (conn->nc_id == 0)
 116                 return EACCES;
 117         error = lockmgr(&conn->nc_lock, LK_EXCLUSIVE | LK_CANRECURSE);
 118         if (error == ERESTART)
 119                 return EINTR;
 120         error = ncp_chkintr(conn, td);
 121         if (error) {
 122                 lockmgr(&conn->nc_lock, LK_RELEASE);
 123                 return error;
 124         }
 125
 126         if (conn->nc_id == 0) {
 127                 lockmgr(&conn->nc_lock, LK_RELEASE);
 128                 return EACCES;
 129         }
 130         conn->td = td;  /* who currently operates */
 131         conn->ucred = cred;
 132         return 0;
 133 }
 134
 135 /*
 136  * NOTE: The lockmgr() call should be protected by nc_lwant, but it
 137  * is unclear whether callers have coded this correctly.
 138  */
 139 int
 140 ncp_conn_lock(struct ncp_conn *conn, struct thread *td,
 141         struct ucred *cred, int mode)
 142 {
 143         int error;
 144
 145         error = ncp_conn_access(conn, cred, mode);
 146         if (error)
 147                 return error;
 148         return ncp_conn_lock_any(conn, td, cred);
 149 }
 150
 151 /*
 152  * Lock conn but unlock connlist
 153  */
 154 static int
 155 ncp_conn_lock2(struct ncp_conn *conn, struct thread *td,
 156         struct ucred *cred, int mode)
 157 {
 158         int error;
 159
 160         error = ncp_conn_access(conn, cred, mode);
 161         if (error) {
 162                 ncp_conn_unlocklist(td);
 163                 return error;
 164         }
 165         conn->nc_lwant++;
 166         ncp_conn_unlocklist(td);
 167         error = ncp_conn_lock_any(conn, td, cred);
 168         conn->nc_lwant--;
 169         if (conn->nc_lwant == 0) {
 170                 wakeup(&conn->nc_lwant);
 171         }
 172         return error;
 173 }
 174
 175 void
 176 ncp_conn_unlock(struct ncp_conn *conn, struct thread *td) {
 177         /*
 178          * note, that LK_RELASE will do wakeup() instead of wakeup_one().
 179          * this will do a little overhead
 180          */
 181         lockmgr(&conn->nc_lock, LK_RELEASE);
 182 }
 183
 184 int
 185 ncp_conn_assert_locked(struct ncp_conn *conn, const char *checker,
 186                        struct thread *td)
 187 {
 188         if (conn->nc_lock.lk_flags & LK_HAVE_EXCL)
 189                 return 0;
 190         kprintf("%s: connection isn't locked!\n", checker);
 191         return EIO;
 192 }
 193
 194 /*
 195  * create, fill with defaults and return in locked state
 196  */
 197 int
 198 ncp_conn_alloc(struct thread *td, struct ucred *cred, struct ncp_conn **conn)
 199 {
 200         int error;
 201         struct ncp_conn *ncp;
 202
 203         MALLOC(ncp, struct ncp_conn *, sizeof(struct ncp_conn),
 204             M_NCPDATA, M_WAITOK | M_ZERO);
 205         error = 0;
 206         lockinit(&ncp->nc_lock, "ncplck", 0, 0);
 207         ncp_conn_cnt++;
 208         ncp->nc_id = ncp_next_ref++;
 209         ncp->nc_owner = cred;
 210         ncp->seq = 0;
 211         ncp->connid = 0xFFFF;
 212         ncp_conn_lock_any(ncp, td, ncp->nc_owner);
 213         *conn = ncp;
 214         ncp_conn_locklist(LK_EXCLUSIVE, td);
 215         SLIST_INSERT_HEAD(&conn_list,ncp,nc_next);
 216         ncp_conn_unlocklist(td);
 217         return (error);
 218 }
 219
 220 /*
 221  * Remove the connection, on entry it must be locked
 222  */
 223 int
 224 ncp_conn_free(struct ncp_conn *ncp)
 225 {
 226         int error;
 227         struct ncp_conn *ncp1;
 228
 229         if (ncp == NULL) {
 230                 NCPFATAL("conn==NULL !\n");
 231                 return(EIO);
 232         }
 233         if (ncp->nc_id == 0) {
 234                 kprintf("already!!!!\n");
 235                 return EACCES;
 236         }
 237         error = ncp_conn_assert_locked(ncp, __func__, ncp->td);
 238         if (error)
 239                 return error;
 240         if (ncp->ref_cnt) {
 241                 NCPFATAL("there are %d references left\n",ncp->ref_cnt);
 242                 return(EBUSY);
 243         }
 244
 245         /*
 246          * Mark conn as died and wait for other process.  This also
 247          * interlocks against other ncp_conn_free() ops.
 248          */
 249         ncp->nc_id = 0;
 250         while (ncp->nc_lwant) {
 251                 ncp_conn_unlock(ncp, ncp->td);
 252                 kprintf("lwant = %d\n", ncp->nc_lwant);
 253                 tsleep(&ncp->nc_lwant, 0, "ncpdr", 2*hz);
 254                 lockmgr(&ncp->nc_lock, LK_EXCLUSIVE);
 255         }
 256         ncp_conn_locklist(LK_EXCLUSIVE, ncp->td);
 257         SLIST_FOREACH(ncp1, &conn_list, nc_next) {
 258                 if (ncp1 == ncp)
 259                         break;
 260         }
 261         KKASSERT(ncp1 == ncp);
 262         SLIST_REMOVE(&conn_list, ncp, ncp_conn, nc_next);
 263         ncp_conn_cnt--;
 264         ncp_conn_unlocklist(ncp->td);
 265         if (ncp->li.user) kfree(ncp->li.user, M_NCPDATA);
 266         if (ncp->li.password) kfree(ncp->li.password, M_NCPDATA);
 267         crfree(ncp->nc_owner);
 268         FREE(ncp, M_NCPDATA);
 269         return (0);
 270 }
 271
 272 /*
 273  * Lookup connection by handle, return a locked conn descriptor
 274  */
 275 int
 276 ncp_conn_getbyref(int ref,struct thread *td,struct ucred *cred, int mode, struct ncp_conn **connpp){
 277         struct ncp_conn *ncp;
 278         int error=0;
 279
 280         ncp_conn_locklist(LK_SHARED, td);
 281         SLIST_FOREACH(ncp, &conn_list, nc_next)
 282                 if (ncp->nc_id == ref) break;
 283         if (ncp == NULL) {
 284                 ncp_conn_unlocklist(td);
 285                 return(EBADF);
 286         }
 287         error = ncp_conn_lock2(ncp, td, cred, mode);
 288         if (!error)
 289                 *connpp = ncp;
 290         return (error);
 291 }
 292 /*
 293  * find attached, but not logged in connection to specified server
 294  */
 295 int
 296 ncp_conn_getattached(struct ncp_conn_args *li,struct thread *td,struct ucred *cred,int mode, struct ncp_conn **connpp){
 297         struct ncp_conn *ncp, *ncp2=NULL;
 298         int error = 0;
 299
 300         ncp_conn_locklist(LK_SHARED, td);
 301         SLIST_FOREACH(ncp, &conn_list, nc_next) {
 302                 if ((ncp->flags & NCPFL_LOGGED) != 0 ||
 303                     strcmp(ncp->li.server,li->server) != 0 ||
 304                     ncp->li.saddr.sa_len != li->saddr.sa_len ||
 305                     bcmp(&ncp->li.saddr,&ncp->li.saddr,li->saddr.sa_len) != 0)
 306                         continue;
 307                 if (ncp_suser(cred) == 0 ||
 308                     cred->cr_uid == ncp->nc_owner->cr_uid)
 309                         break;
 310                 error = ncp_conn_access(ncp,cred,mode);
 311                 if (!error && ncp2 == NULL)
 312                         ncp2 = ncp;
 313         }
 314         if (ncp == NULL) ncp = ncp2;
 315         if (ncp == NULL) {
 316                 ncp_conn_unlocklist(td);
 317                 return(EBADF);
 318         }
 319         error = ncp_conn_lock2(ncp,td,cred,mode);
 320         if (!error)
 321                 *connpp=ncp;
 322         return (error);
 323 }
 324
 325 /*
 326  * Lookup connection by server/user pair, return a locked conn descriptor.
 327  * if li is NULL or server/user pair incomplete, try to select best connection
 328  * based on owner.
 329  * Connection selected in next order:
 330  * 1. Try to search conn with ucred owner, if li is NULL also find a primary
 331  * 2. If 1. fails try to get first suitable shared connection
 332  * 3. If 2. fails then nothing can help to poor ucred owner
 333  */
 334
 335 int
 336 ncp_conn_getbyli(struct ncp_conn_args *li, struct thread *td,
 337         struct ucred *cred, int mode, struct ncp_conn **connpp)
 338 {
 339         struct ncp_conn *ncp, *ncp2=NULL;
 340         int error=0, partial, haveserv;
 341
 342         partial = (li == NULL || li->server[0] == 0 || li->user == NULL);
 343         haveserv = (li && li->server[0]);
 344         ncp_conn_locklist(LK_SHARED, td);
 345         SLIST_FOREACH(ncp, &conn_list, nc_next) {
 346                 if (partial) {
 347                         if (cred->cr_uid == ncp->nc_owner->cr_uid) {
 348                                 if (haveserv) {
 349                                         if (strcmp(ncp->li.server,li->server) == 0)
 350                                                 break;
 351                                 } else {
 352                                         if (ncp->flags & NCPFL_PRIMARY)
 353                                                 break;
 354                                         ncp2 = ncp;
 355                                 }
 356                                 continue;
 357                         }
 358                 } else {
 359                         if (strcmp(ncp->li.server,li->server) != 0 ||
 360                             ncp->li.user == NULL ||
 361                             strcmp(ncp->li.user,li->user) != 0)
 362                                 continue;
 363                         if (cred->cr_uid == ncp->nc_owner->cr_uid)
 364                                 break;
 365                         if (ncp_suser(cred) == 0)
 366                                 ncp2 = ncp;
 367                 }
 368                 error = ncp_conn_access(ncp,cred,mode);
 369                 if (!error && ncp2 == NULL)
 370                         ncp2 = ncp;
 371         }
 372         if (ncp == NULL) ncp = ncp2;
 373         if (ncp == NULL) {
 374                 ncp_conn_unlocklist(td);
 375                 return(EBADF);
 376         }
 377         error = ncp_conn_lock2(ncp,td,cred,mode);
 378         if (!error)
 379                 *connpp=ncp;
 380         return (error);
 381 }
 382
 383 /*
 384  * Set primary connection flag, since it have sence only for an owner,
 385  * only owner can modify this flag.
 386  * connection expected to be locked.
 387  */
 388 int
 389 ncp_conn_setprimary(struct ncp_conn *conn, int on){
 390         struct ncp_conn *ncp=NULL;
 391
 392         if (conn->ucred->cr_uid != conn->nc_owner->cr_uid)
 393                 return EACCES;
 394         ncp_conn_locklist(LK_SHARED, conn->td);
 395         SLIST_FOREACH(ncp, &conn_list, nc_next) {
 396                 if (conn->ucred->cr_uid == ncp->nc_owner->cr_uid)
 397                         ncp->flags &= ~NCPFL_PRIMARY;
 398         }
 399         ncp_conn_unlocklist(conn->td);
 400         if (on)
 401                 conn->flags |= NCPFL_PRIMARY;
 402         return 0;
 403 }
 404 /*
 405  * Lease conn to given proc, returning unique handle
 406  * problem: how locks should be applied ?
 407  */
 408 int
 409 ncp_conn_gethandle(struct ncp_conn *conn, struct thread *td, struct ncp_handle **handle){
 410         struct ncp_handle *refp;
 411
 412         lockmgr(&lhlock, LK_EXCLUSIVE);
 413         SLIST_FOREACH(refp, &lhlist, nh_next)
 414                 if (refp->nh_conn == conn && td == refp->nh_td) break;
 415         if (refp) {
 416                 conn->ref_cnt++;
 417                 refp->nh_ref++;
 418                 *handle = refp;
 419                 lockmgr(&lhlock, LK_RELEASE);
 420                 return 0;
 421         }
 422         MALLOC(refp,struct ncp_handle *,sizeof(struct ncp_handle),M_NCPDATA,
 423             M_WAITOK | M_ZERO);
 424         SLIST_INSERT_HEAD(&lhlist,refp,nh_next);
 425         refp->nh_ref++;
 426         refp->nh_td = td;
 427         refp->nh_conn = conn;
 428         refp->nh_id = ncp_next_handle++;
 429         *handle = refp;
 430         conn->ref_cnt++;
 431         lockmgr(&lhlock, LK_RELEASE);
 432         return 0;
 433 }
 434 /*
 435  * release reference, if force - ignore refcount
 436  */
 437 int
 438 ncp_conn_puthandle(struct ncp_handle *handle, struct thread *td, int force) {
 439         struct ncp_handle *refp = handle;
 440
 441         lockmgr(&lhlock, LK_EXCLUSIVE);
 442         refp->nh_ref--;
 443         refp->nh_conn->ref_cnt--;
 444         if (force) {
 445                 refp->nh_conn->ref_cnt -= refp->nh_ref;
 446                 refp->nh_ref = 0;
 447         }
 448         if (refp->nh_ref == 0) {
 449                 SLIST_REMOVE(&lhlist, refp, ncp_handle, nh_next);
 450                 FREE(refp, M_NCPDATA);
 451         }
 452         lockmgr(&lhlock, LK_RELEASE);
 453         return 0;
 454 }
 455 /*
 456  * find a connHandle
 457  */
 458 int
 459 ncp_conn_findhandle(int connHandle, struct thread *td, struct ncp_handle **handle) {
 460         struct ncp_handle *refp;
 461
 462         lockmgr(&lhlock, LK_SHARED);
 463         SLIST_FOREACH(refp, &lhlist, nh_next)
 464                 if (refp->nh_td == td && refp->nh_id == connHandle) break;
 465         lockmgr(&lhlock, LK_RELEASE);
 466         if (refp == NULL) {
 467                 return EBADF;
 468         }
 469         *handle = refp;
 470         return 0;
 471 }
 472 /*
 473  * Clear handles associated with specified process
 474  */
 475 int
 476 ncp_conn_putprochandles(struct thread *td) {
 477         struct ncp_handle *hp, *nhp;
 478         int haveone = 0;
 479
 480         lockmgr(&lhlock, LK_EXCLUSIVE);
 481         for (hp = SLIST_FIRST(&lhlist); hp; hp = nhp) {
 482                 nhp = SLIST_NEXT(hp, nh_next);
 483                 if (hp->nh_td != td) continue;
 484                 haveone = 1;
 485                 hp->nh_conn->ref_cnt -= hp->nh_ref;
 486                 SLIST_REMOVE(&lhlist, hp, ncp_handle, nh_next);
 487                 FREE(hp, M_NCPDATA);
 488         }
 489         lockmgr(&lhlock, LK_RELEASE);
 490         return haveone;
 491 }
 492 /*
 493  * remove references in all possible connections,
 494  * XXX - possible problem is a locked list.
 495  */
 496 /*void
 497 ncp_conn_list_rm_ref(pid_t pid) {
 498         struct ncp_conn *ncp;
 499
 500         ncp_conn_locklist(LK_SHARED, NULL);
 501         SLIST_FOREACH(ncp, &conn_list, nc_next) {
 502                 ncp_conn_rm_ref(ncp,pid,1);
 503         }
 504         ncp_conn_unlocklist(NULL);
 505         return;
 506 }
 507 */
 508 int
 509 ncp_conn_getinfo(struct ncp_conn *ncp, struct ncp_conn_stat *ncs) {
 510         bzero(ncs,sizeof(*ncs));
 511         ncs->li = ncp->li;
 512         ncs->li.user = ncs->user;
 513         if (ncp->li.user)
 514                 strcpy(ncs->user, ncp->li.user);
 515         ncs->li.password = NULL;
 516         ncs->connRef = ncp->nc_id;
 517         ncs->ref_cnt = ncp->ref_cnt;
 518         ncs->connid = ncp->connid;
 519         ncs->owner = ncp->nc_owner->cr_uid;
 520         ncs->group = ncp->nc_group;
 521         ncs->flags = ncp->flags;
 522         ncs->buffer_size = ncp->buffer_size;
 523         return 0;
 524 }
 525
 526 static int
 527 ncp_sysctl_connstat(SYSCTL_HANDLER_ARGS) {
 528         int error;
 529         struct ncp_conn_stat ncs;
 530         struct ncp_conn *ncp;
 531 /*      struct ucred *cred = req->p->p_ucred;*/
 532
 533         error = 0;
 534         ncp_conn_locklist(LK_SHARED, req->td);
 535         error = SYSCTL_OUT(req, &ncp_conn_cnt, sizeof(ncp_conn_cnt));
 536         SLIST_FOREACH(ncp, &conn_list, nc_next) {
 537                 if (error) break;
 538                 /* I can't do conn_lock while list is locked */
 539                 ncp->nc_lwant++;
 540                 if (!error) {
 541                         ncp_conn_getinfo(ncp, &ncs);
 542                 } else {
 543                         bzero(&ncs,sizeof(ncs));
 544                         ncs.connRef = ncp->nc_id;
 545                         strcpy(ncs.li.server,"***");
 546                 }
 547                 ncp->nc_lwant--;
 548                 error = SYSCTL_OUT(req, &ncs, sizeof(ncs));
 549         }
 550         ncp_conn_unlocklist(req->td);
 551         return(error);
 552 }