1 /*-
2 * Copyright (c) 1989, 1993
3 * The Regents of the University of California. All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Rick Macklem at The University of Guelph.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 4. Neither the name of the University nor the names of its 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 REGENTS 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 REGENTS 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 *
32 * @(#)nfs_syscalls.c 8.5 (Berkeley) 3/30/95
33 */
34
35 #include <sys/cdefs.h>
36 __FBSDID("$FreeBSD: stable/10/sys/nfsserver/nfs_srvkrpc.c 280258 2015-03-19 13:37:36Z rwatson $");
37
38 #include "opt_inet6.h"
39 #include "opt_kgssapi.h"
40
41 #include <sys/param.h>
42 #include <sys/capsicum.h>
43 #include <sys/systm.h>
44 #include <sys/sysproto.h>
45 #include <sys/kernel.h>
46 #include <sys/sysctl.h>
47 #include <sys/file.h>
48 #include <sys/filedesc.h>
49 #include <sys/jail.h>
50 #include <sys/vnode.h>
51 #include <sys/malloc.h>
52 #include <sys/mount.h>
53 #include <sys/priv.h>
54 #include <sys/proc.h>
55 #include <sys/bio.h>
56 #include <sys/buf.h>
57 #include <sys/mbuf.h>
58 #include <sys/socket.h>
59 #include <sys/socketvar.h>
60 #include <sys/domain.h>
61 #include <sys/protosw.h>
62 #include <sys/namei.h>
63 #include <sys/fcntl.h>
64 #include <sys/lockf.h>
65 #include <sys/eventhandler.h>
66
67 #include <netinet/in.h>
68 #include <netinet/tcp.h>
69 #ifdef INET6
70 #include <net/if.h>
71 #include <netinet6/in6_var.h>
72 #endif
73
74 #include <rpc/rpc.h>
75 #include <rpc/rpcsec_gss.h>
76 #include <rpc/replay.h>
77
78 #include <nfs/xdr_subs.h>
79 #include <nfs/nfsproto.h>
80 #include <nfs/nfs_fha.h>
81 #include <nfsserver/nfs.h>
82 #include <nfsserver/nfsm_subs.h>
83 #include <nfsserver/nfsrvcache.h>
84 #include <nfsserver/nfs_fha_old.h>
85
86 #include <security/mac/mac_framework.h>
87
88 static MALLOC_DEFINE(M_NFSSVC, "nfss_srvsock", "Nfs server structure");
89
90 MALLOC_DEFINE(M_NFSRVDESC, "nfss_srvdesc", "NFS server socket descriptor");
91 MALLOC_DEFINE(M_NFSD, "nfss_daemon", "Nfs server daemon structure");
92
93 #define TRUE 1
94 #define FALSE 0
95
96 SYSCTL_DECL(_vfs_nfsrv);
97
98 SVCPOOL *nfsrv_pool;
99 int nfsd_waiting = 0;
100 int nfsrv_numnfsd = 0;
101 struct callout nfsrv_callout;
102 static eventhandler_tag nfsrv_nmbclusters_tag;
103
104 static int nfs_privport = 0;
105 SYSCTL_INT(_vfs_nfsrv, NFS_NFSPRIVPORT, nfs_privport, CTLFLAG_RW,
106 &nfs_privport, 0,
107 "Only allow clients using a privileged port");
108 SYSCTL_INT(_vfs_nfsrv, OID_AUTO, gatherdelay, CTLFLAG_RW,
109 &nfsrvw_procrastinate, 0,
110 "Delay value for write gathering");
111 SYSCTL_INT(_vfs_nfsrv, OID_AUTO, gatherdelay_v3, CTLFLAG_RW,
112 &nfsrvw_procrastinate_v3, 0,
113 "Delay in seconds for NFSv3 write gathering");
114
115 static int nfssvc_addsock(struct file *, struct thread *);
116 static int nfssvc_nfsd(struct thread *, struct nfsd_nfsd_args *);
117
118 extern u_long sb_max_adj;
119
120 int32_t (*nfsrv3_procs[NFS_NPROCS])(struct nfsrv_descript *nd,
121 struct nfssvc_sock *slp, struct mbuf **mreqp) = {
122 nfsrv_null,
123 nfsrv_getattr,
124 nfsrv_setattr,
125 nfsrv_lookup,
126 nfsrv3_access,
127 nfsrv_readlink,
128 nfsrv_read,
129 nfsrv_write,
130 nfsrv_create,
131 nfsrv_mkdir,
132 nfsrv_symlink,
133 nfsrv_mknod,
134 nfsrv_remove,
135 nfsrv_rmdir,
136 nfsrv_rename,
137 nfsrv_link,
138 nfsrv_readdir,
139 nfsrv_readdirplus,
140 nfsrv_statfs,
141 nfsrv_fsinfo,
142 nfsrv_pathconf,
143 nfsrv_commit,
144 nfsrv_noop
145 };
146
147 /*
148 * NFS server system calls
149 */
150 /*
151 * This is now called from nfssvc() in nfs/nfs_nfssvc.c.
152 */
153
154 /*
155 * Nfs server psuedo system call for the nfsd's
156 * Based on the flag value it either:
157 * - adds a socket to the selection list
158 * - remains in the kernel as an nfsd
159 * - remains in the kernel as an nfsiod
160 * For INET6 we suppose that nfsd provides only IN6P_IPV6_V6ONLY sockets
161 * and that mountd provides
162 * - sockaddr with no IPv4-mapped addresses
163 * - mask for both INET and INET6 families if there is IPv4-mapped overlap
164 */
165 int
nfssvc_nfsserver(struct thread * td,struct nfssvc_args * uap)166 nfssvc_nfsserver(struct thread *td, struct nfssvc_args *uap)
167 {
168 struct file *fp;
169 struct nfsd_addsock_args addsockarg;
170 struct nfsd_nfsd_args nfsdarg;
171 cap_rights_t rights;
172 int error;
173
174 if (uap->flag & NFSSVC_ADDSOCK) {
175 error = copyin(uap->argp, (caddr_t)&addsockarg,
176 sizeof(addsockarg));
177 if (error)
178 return (error);
179 error = fget(td, addsockarg.sock,
180 cap_rights_init(&rights, CAP_SOCK_SERVER), &fp);
181 if (error)
182 return (error);
183 if (fp->f_type != DTYPE_SOCKET) {
184 fdrop(fp, td);
185 return (error); /* XXXRW: Should be EINVAL? */
186 }
187 error = nfssvc_addsock(fp, td);
188 fdrop(fp, td);
189 } else if (uap->flag & NFSSVC_OLDNFSD)
190 error = nfssvc_nfsd(td, NULL);
191 else if (uap->flag & NFSSVC_NFSD) {
192 if (!uap->argp)
193 return (EINVAL);
194 error = copyin(uap->argp, (caddr_t)&nfsdarg,
195 sizeof(nfsdarg));
196 if (error)
197 return (error);
198 error = nfssvc_nfsd(td, &nfsdarg);
199 } else
200 error = ENXIO;
201 return (error);
202 }
203
204 /*
205 * Generate the rpc reply header
206 * siz arg. is used to decide if adding a cluster is worthwhile
207 */
208 struct mbuf *
nfs_rephead(int siz,struct nfsrv_descript * nd,int err,struct mbuf ** mbp,caddr_t * bposp)209 nfs_rephead(int siz, struct nfsrv_descript *nd, int err,
210 struct mbuf **mbp, caddr_t *bposp)
211 {
212 u_int32_t *tl;
213 struct mbuf *mreq;
214 caddr_t bpos;
215 struct mbuf *mb;
216
217 if (err == EBADRPC)
218 return (NULL);
219
220 nd->nd_repstat = err;
221 if (err && (nd->nd_flag & ND_NFSV3) == 0) /* XXX recheck */
222 siz = 0;
223
224 MGET(mreq, M_WAITOK, MT_DATA);
225
226 /*
227 * If this is a big reply, use a cluster
228 */
229 mreq->m_len = 0;
230 if (siz >= MINCLSIZE) {
231 MCLGET(mreq, M_WAITOK);
232 }
233 mb = mreq;
234 bpos = mtod(mb, caddr_t);
235
236 if (err != NFSERR_RETVOID) {
237 tl = nfsm_build(u_int32_t *, NFSX_UNSIGNED);
238 if (err)
239 *tl = txdr_unsigned(nfsrv_errmap(nd, err));
240 else
241 *tl = 0;
242 }
243
244 *mbp = mb;
245 *bposp = bpos;
246 if (err != 0 && err != NFSERR_RETVOID)
247 nfsrvstats.srvrpc_errs++;
248
249 return (mreq);
250 }
251
252 static void
nfssvc_program(struct svc_req * rqst,SVCXPRT * xprt)253 nfssvc_program(struct svc_req *rqst, SVCXPRT *xprt)
254 {
255 rpcproc_t procnum;
256 int32_t (*proc)(struct nfsrv_descript *nd, struct nfssvc_sock *slp,
257 struct mbuf **mreqp);
258 int flag;
259 struct nfsrv_descript nd;
260 struct mbuf *mreq, *mrep;
261 int error;
262
263 if (rqst->rq_vers == NFS_VER2) {
264 if (rqst->rq_proc > NFSV2PROC_STATFS) {
265 svcerr_noproc(rqst);
266 svc_freereq(rqst);
267 return;
268 }
269 procnum = nfsrv_nfsv3_procid[rqst->rq_proc];
270 flag = 0;
271 } else {
272 if (rqst->rq_proc >= NFS_NPROCS) {
273 svcerr_noproc(rqst);
274 svc_freereq(rqst);
275 return;
276 }
277 procnum = rqst->rq_proc;
278 flag = ND_NFSV3;
279 }
280 proc = nfsrv3_procs[procnum];
281
282 mreq = mrep = NULL;
283 mreq = rqst->rq_args;
284 rqst->rq_args = NULL;
285 (void)nfs_realign(&mreq, M_WAITOK);
286
287 /*
288 * Note: we want rq_addr, not svc_getrpccaller for nd_nam2 -
289 * NFS_SRVMAXDATA uses a NULL value for nd_nam2 to detect TCP
290 * mounts.
291 */
292 memset(&nd, 0, sizeof(nd));
293 nd.nd_md = nd.nd_mrep = mreq;
294 nd.nd_dpos = mtod(mreq, caddr_t);
295 nd.nd_nam = svc_getrpccaller(rqst);
296 nd.nd_nam2 = rqst->rq_addr;
297 nd.nd_procnum = procnum;
298 nd.nd_cr = NULL;
299 nd.nd_flag = flag;
300
301 if (nfs_privport) {
302 /* Check if source port is privileged */
303 u_short port;
304 struct sockaddr *nam = nd.nd_nam;
305 struct sockaddr_in *sin;
306
307 sin = (struct sockaddr_in *)nam;
308 /*
309 * INET/INET6 - same code:
310 * sin_port and sin6_port are at same offset
311 */
312 port = ntohs(sin->sin_port);
313 if (port >= IPPORT_RESERVED &&
314 nd.nd_procnum != NFSPROC_NULL) {
315 #ifdef INET6
316 char b6[INET6_ADDRSTRLEN];
317 #if defined(KLD_MODULE)
318 /* Do not use ip6_sprintf: the nfs module should work without INET6. */
319 #define ip6_sprintf(buf, a) \
320 (sprintf((buf), "%x:%x:%x:%x:%x:%x:%x:%x", \
321 (a)->s6_addr16[0], (a)->s6_addr16[1], \
322 (a)->s6_addr16[2], (a)->s6_addr16[3], \
323 (a)->s6_addr16[4], (a)->s6_addr16[5], \
324 (a)->s6_addr16[6], (a)->s6_addr16[7]), \
325 (buf))
326 #endif
327 #endif
328 printf("NFS request from unprivileged port (%s:%d)\n",
329 #ifdef INET6
330 sin->sin_family == AF_INET6 ?
331 ip6_sprintf(b6, &satosin6(sin)->sin6_addr) :
332 #if defined(KLD_MODULE)
333 #undef ip6_sprintf
334 #endif
335 #endif
336 inet_ntoa(sin->sin_addr), port);
337 m_freem(mreq);
338 svcerr_weakauth(rqst);
339 svc_freereq(rqst);
340 return;
341 }
342 }
343
344 if (proc != nfsrv_null) {
345 if (!svc_getcred(rqst, &nd.nd_cr, &nd.nd_credflavor)) {
346 m_freem(mreq);
347 svcerr_weakauth(rqst);
348 svc_freereq(rqst);
349 return;
350 }
351 #ifdef MAC
352 mac_cred_associate_nfsd(nd.nd_cr);
353 #endif
354 }
355 nfsrvstats.srvrpccnt[nd.nd_procnum]++;
356
357 error = proc(&nd, NULL, &mrep);
358
359 if (nd.nd_cr)
360 crfree(nd.nd_cr);
361
362 if (mrep == NULL) {
363 svcerr_decode(rqst);
364 svc_freereq(rqst);
365 return;
366 }
367 if (error && error != NFSERR_RETVOID) {
368 svcerr_systemerr(rqst);
369 svc_freereq(rqst);
370 return;
371 }
372 if (nd.nd_repstat & NFSERR_AUTHERR) {
373 svcerr_auth(rqst, nd.nd_repstat & ~NFSERR_AUTHERR);
374 m_freem(mrep);
375 } else {
376 if (!svc_sendreply_mbuf(rqst, mrep))
377 svcerr_systemerr(rqst);
378 }
379 svc_freereq(rqst);
380 }
381
382 /*
383 * Adds a socket to the list for servicing by nfsds.
384 */
385 static int
nfssvc_addsock(struct file * fp,struct thread * td)386 nfssvc_addsock(struct file *fp, struct thread *td)
387 {
388 int siz;
389 struct socket *so;
390 int error;
391 SVCXPRT *xprt;
392
393 so = fp->f_data;
394
395 siz = sb_max_adj;
396 error = soreserve(so, siz, siz);
397 if (error)
398 return (error);
399
400 /*
401 * Steal the socket from userland so that it doesn't close
402 * unexpectedly.
403 */
404 if (so->so_type == SOCK_DGRAM)
405 xprt = svc_dg_create(nfsrv_pool, so, 0, 0);
406 else
407 xprt = svc_vc_create(nfsrv_pool, so, 0, 0);
408 if (xprt) {
409 fp->f_ops = &badfileops;
410 fp->f_data = NULL;
411 svc_reg(xprt, NFS_PROG, NFS_VER2, nfssvc_program, NULL);
412 svc_reg(xprt, NFS_PROG, NFS_VER3, nfssvc_program, NULL);
413 SVC_RELEASE(xprt);
414 }
415
416 return (0);
417 }
418
419 /*
420 * Called by nfssvc() for nfsds. Just loops around servicing rpc requests
421 * until it is killed by a signal.
422 */
423 static int
nfssvc_nfsd(struct thread * td,struct nfsd_nfsd_args * args)424 nfssvc_nfsd(struct thread *td, struct nfsd_nfsd_args *args)
425 {
426 char principal[128];
427 int error;
428
429 if (args) {
430 error = copyinstr(args->principal, principal,
431 sizeof(principal), NULL);
432 if (error)
433 return (error);
434 } else {
435 memcpy(principal, "nfs@", 4);
436 getcredhostname(td->td_ucred, principal + 4,
437 sizeof(principal) - 4);
438 }
439
440 /*
441 * Only the first nfsd actually does any work. The RPC code
442 * adds threads to it as needed. Any extra processes offered
443 * by nfsd just exit. If nfsd is new enough, it will call us
444 * once with a structure that specifies how many threads to
445 * use.
446 */
447 NFSD_LOCK();
448 if (nfsrv_numnfsd == 0) {
449 nfsrv_numnfsd++;
450
451 NFSD_UNLOCK();
452
453 rpc_gss_set_svc_name_call(principal, "kerberosv5",
454 GSS_C_INDEFINITE, NFS_PROG, NFS_VER2);
455 rpc_gss_set_svc_name_call(principal, "kerberosv5",
456 GSS_C_INDEFINITE, NFS_PROG, NFS_VER3);
457
458 if (args) {
459 nfsrv_pool->sp_minthreads = args->minthreads;
460 nfsrv_pool->sp_maxthreads = args->maxthreads;
461 } else {
462 nfsrv_pool->sp_minthreads = 4;
463 nfsrv_pool->sp_maxthreads = 4;
464 }
465
466 svc_run(nfsrv_pool);
467
468 rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER2);
469 rpc_gss_clear_svc_name_call(NFS_PROG, NFS_VER3);
470
471 NFSD_LOCK();
472 nfsrv_numnfsd--;
473 nfsrv_init(TRUE);
474 }
475 NFSD_UNLOCK();
476
477 return (0);
478 }
479
480 /*
481 * Size the NFS server's duplicate request cache at 1/2 the
482 * nmbclusters, floating within a (64, 2048) range. This is to
483 * prevent all mbuf clusters being tied up in the NFS dupreq
484 * cache for small values of nmbclusters.
485 */
486 static size_t
nfsrv_replay_size(void)487 nfsrv_replay_size(void)
488 {
489 size_t replaysiz;
490
491 replaysiz = nmbclusters / 2;
492 if (replaysiz > NFSRVCACHE_MAX_SIZE)
493 replaysiz = NFSRVCACHE_MAX_SIZE;
494 if (replaysiz < NFSRVCACHE_MIN_SIZE)
495 replaysiz = NFSRVCACHE_MIN_SIZE;
496 replaysiz *= MCLBYTES;
497
498 return (replaysiz);
499 }
500
501 /*
502 * Called when nmbclusters changes - we resize the replay cache
503 * accordingly.
504 */
505 static void
nfsrv_nmbclusters_change(void * tag)506 nfsrv_nmbclusters_change(void *tag)
507 {
508
509 if (nfsrv_pool)
510 replay_setsize(nfsrv_pool->sp_rcache, nfsrv_replay_size());
511 }
512
513 /*
514 * Initialize the data structures for the server.
515 * Handshake with any new nfsds starting up to avoid any chance of
516 * corruption.
517 */
518 void
nfsrv_init(int terminating)519 nfsrv_init(int terminating)
520 {
521
522 NFSD_LOCK_ASSERT();
523
524 if (terminating) {
525 NFSD_UNLOCK();
526 EVENTHANDLER_DEREGISTER(nmbclusters_change,
527 nfsrv_nmbclusters_tag);
528 svcpool_destroy(nfsrv_pool);
529 nfsrv_pool = NULL;
530 NFSD_LOCK();
531 } else
532 nfs_pub.np_valid = 0;
533
534 NFSD_UNLOCK();
535
536 nfsrv_pool = svcpool_create("nfsd", SYSCTL_STATIC_CHILDREN(_vfs_nfsrv));
537 nfsrv_pool->sp_rcache = replay_newcache(nfsrv_replay_size());
538 nfsrv_pool->sp_assign = fhaold_assign;
539 nfsrv_pool->sp_done = fha_nd_complete;
540 nfsrv_nmbclusters_tag = EVENTHANDLER_REGISTER(nmbclusters_change,
541 nfsrv_nmbclusters_change, NULL, EVENTHANDLER_PRI_FIRST);
542
543 NFSD_LOCK();
544 }
545