1 /* $NetBSD: nfs_iod.c,v 1.9 2023/03/21 15:47:46 christos Exp $ */
2
3 /*
4 * Copyright (c) 1989, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Rick Macklem at The University of Guelph.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 *
34 * @(#)nfs_syscalls.c 8.5 (Berkeley) 3/30/95
35 */
36
37 #include <sys/cdefs.h>
38 __KERNEL_RCSID(0, "$NetBSD: nfs_iod.c,v 1.9 2023/03/21 15:47:46 christos Exp $");
39
40 #include <sys/param.h>
41 #include <sys/systm.h>
42 #include <sys/kernel.h>
43 #include <sys/file.h>
44 #include <sys/stat.h>
45 #include <sys/vnode.h>
46 #include <sys/mount.h>
47 #include <sys/proc.h>
48 #include <sys/uio.h>
49 #include <sys/malloc.h>
50 #include <sys/kmem.h>
51 #include <sys/buf.h>
52 #include <sys/mbuf.h>
53 #include <sys/socket.h>
54 #include <sys/socketvar.h>
55 #include <sys/signalvar.h>
56 #include <sys/domain.h>
57 #include <sys/protosw.h>
58 #include <sys/namei.h>
59 #include <sys/syslog.h>
60 #include <sys/filedesc.h>
61 #include <sys/kthread.h>
62 #include <sys/kauth.h>
63 #include <sys/syscallargs.h>
64
65 #include <netinet/in.h>
66 #include <netinet/tcp.h>
67 #include <nfs/xdr_subs.h>
68 #include <nfs/rpcv2.h>
69 #include <nfs/nfsproto.h>
70 #include <nfs/nfs.h>
71 #include <nfs/nfsm_subs.h>
72 #include <nfs/nfsrvcache.h>
73 #include <nfs/nfsmount.h>
74 #include <nfs/nfsnode.h>
75 #include <nfs/nfsrtt.h>
76 #include <nfs/nfs_var.h>
77
78 extern int nuidhash_max;
79
80 /*
81 * locking order:
82 * nfs_iodlist_lock -> nid_lock -> nm_lock
83 */
84 kmutex_t nfs_iodlist_lock;
85 struct nfs_iodlist nfs_iodlist_idle;
86 struct nfs_iodlist nfs_iodlist_all;
87 int nfs_niothreads = -1; /* == "0, and has never been set" */
88 int nfs_defect = 0;
89
90 /*
91 * Asynchronous I/O threads for client nfs.
92 * They do read-ahead and write-behind operations on the block I/O cache.
93 * Never returns unless it fails or gets killed.
94 */
95
96 static void
nfssvc_iod(void * arg)97 nfssvc_iod(void *arg)
98 {
99 struct buf *bp;
100 struct nfs_iod *myiod;
101 struct nfsmount *nmp;
102
103 myiod = kmem_alloc(sizeof(*myiod), KM_SLEEP);
104 mutex_init(&myiod->nid_lock, MUTEX_DEFAULT, IPL_NONE);
105 cv_init(&myiod->nid_cv, "nfsiod");
106 myiod->nid_exiting = false;
107 myiod->nid_mount = NULL;
108 mutex_enter(&nfs_iodlist_lock);
109 LIST_INSERT_HEAD(&nfs_iodlist_all, myiod, nid_all);
110 mutex_exit(&nfs_iodlist_lock);
111
112 for (;;) {
113 mutex_enter(&nfs_iodlist_lock);
114 LIST_INSERT_HEAD(&nfs_iodlist_idle, myiod, nid_idle);
115 mutex_exit(&nfs_iodlist_lock);
116
117 mutex_enter(&myiod->nid_lock);
118 while (/*CONSTCOND*/ true) {
119 nmp = myiod->nid_mount;
120 if (nmp) {
121 myiod->nid_mount = NULL;
122 break;
123 }
124 if (__predict_false(myiod->nid_exiting)) {
125 /*
126 * drop nid_lock to preserve locking order.
127 */
128 mutex_exit(&myiod->nid_lock);
129 mutex_enter(&nfs_iodlist_lock);
130 mutex_enter(&myiod->nid_lock);
131 /*
132 * recheck nid_mount because nfs_asyncio can
133 * pick us in the meantime as we are still on
134 * nfs_iodlist_lock.
135 */
136 if (myiod->nid_mount != NULL) {
137 mutex_exit(&nfs_iodlist_lock);
138 continue;
139 }
140 LIST_REMOVE(myiod, nid_idle);
141 mutex_exit(&nfs_iodlist_lock);
142 goto quit;
143 }
144 cv_wait(&myiod->nid_cv, &myiod->nid_lock);
145 }
146 mutex_exit(&myiod->nid_lock);
147
148 mutex_enter(&nmp->nm_lock);
149 while ((bp = TAILQ_FIRST(&nmp->nm_bufq)) != NULL) {
150 /* Take one off the front of the list */
151 TAILQ_REMOVE(&nmp->nm_bufq, bp, b_freelist);
152 nmp->nm_bufqlen--;
153 if (nmp->nm_bufqlen < 2 * nmp->nm_bufqiods) {
154 cv_broadcast(&nmp->nm_aiocv);
155 }
156 mutex_exit(&nmp->nm_lock);
157 KERNEL_LOCK(1, curlwp);
158 (void)nfs_doio(bp);
159 KERNEL_UNLOCK_LAST(curlwp);
160 mutex_enter(&nmp->nm_lock);
161 /*
162 * If there are more than one iod on this mount,
163 * then defect so that the iods can be shared out
164 * fairly between the mounts
165 */
166 if (nfs_defect && nmp->nm_bufqiods > 1) {
167 break;
168 }
169 }
170 KASSERT(nmp->nm_bufqiods > 0);
171 nmp->nm_bufqiods--;
172 mutex_exit(&nmp->nm_lock);
173 }
174 quit:
175 KASSERT(myiod->nid_mount == NULL);
176 mutex_exit(&myiod->nid_lock);
177
178 cv_destroy(&myiod->nid_cv);
179 mutex_destroy(&myiod->nid_lock);
180 kmem_free(myiod, sizeof(*myiod));
181
182 kthread_exit(0);
183 }
184
185 void
nfs_iodinit(void)186 nfs_iodinit(void)
187 {
188
189 mutex_init(&nfs_iodlist_lock, MUTEX_DEFAULT, IPL_NONE);
190 LIST_INIT(&nfs_iodlist_all);
191 LIST_INIT(&nfs_iodlist_idle);
192 }
193
194 void
nfs_iodfini(void)195 nfs_iodfini(void)
196 {
197 int error __diagused;
198
199 error = nfs_set_niothreads(0);
200 KASSERT(error == 0);
201 mutex_destroy(&nfs_iodlist_lock);
202 }
203
204 int
nfs_iodbusy(struct nfsmount * nmp)205 nfs_iodbusy(struct nfsmount *nmp)
206 {
207 struct nfs_iod *iod;
208 int ret = 0;
209
210 mutex_enter(&nfs_iodlist_lock);
211 LIST_FOREACH(iod, &nfs_iodlist_all, nid_all) {
212 if (iod->nid_mount == nmp)
213 ret++;
214 }
215 mutex_exit(&nfs_iodlist_lock);
216
217 return ret;
218 }
219
220 int
nfs_set_niothreads(int newval)221 nfs_set_niothreads(int newval)
222 {
223 struct nfs_iod *nid;
224 int error = 0;
225 int hold_count;
226
227 KERNEL_UNLOCK_ALL(curlwp, &hold_count);
228
229 mutex_enter(&nfs_iodlist_lock);
230 /* clamp to sane range */
231 nfs_niothreads = uimax(0, uimin(newval, NFS_MAXASYNCDAEMON));
232
233 while (nfs_numasync != nfs_niothreads && error == 0) {
234 while (nfs_numasync < nfs_niothreads) {
235
236 /*
237 * kthread_create can wait for pagedaemon and
238 * pagedaemon can wait for nfsiod which needs to acquire
239 * nfs_iodlist_lock.
240 */
241
242 mutex_exit(&nfs_iodlist_lock);
243 error = kthread_create(PRI_NONE, KTHREAD_MPSAFE, NULL,
244 nfssvc_iod, NULL, NULL, "nfsio");
245 mutex_enter(&nfs_iodlist_lock);
246 if (error) {
247 /* give up */
248 nfs_niothreads = nfs_numasync;
249 break;
250 }
251 nfs_numasync++;
252 }
253 while (nfs_numasync > nfs_niothreads) {
254 nid = LIST_FIRST(&nfs_iodlist_all);
255 if (nid == NULL) {
256 /* iod has not started yet. */
257 kpause("nfsiorm", false, hz, &nfs_iodlist_lock);
258 continue;
259 }
260 LIST_REMOVE(nid, nid_all);
261 mutex_enter(&nid->nid_lock);
262 KASSERT(!nid->nid_exiting);
263 nid->nid_exiting = true;
264 cv_signal(&nid->nid_cv);
265 mutex_exit(&nid->nid_lock);
266 nfs_numasync--;
267 }
268 }
269 mutex_exit(&nfs_iodlist_lock);
270
271 KERNEL_LOCK(hold_count, curlwp);
272 return error;
273 }
274
275 /*
276 * Get an authorization string for the uid by having the mount_nfs sitting
277 * on this mount point porpous out of the kernel and do it.
278 */
279 int
nfs_getauth(struct nfsmount * nmp,struct nfsreq * rep,kauth_cred_t cred,char ** auth_str,int * auth_len,char * verf_str,int * verf_len,NFSKERBKEY_T key)280 nfs_getauth(struct nfsmount *nmp, struct nfsreq *rep, kauth_cred_t cred, char **auth_str, int *auth_len, char *verf_str, int *verf_len, NFSKERBKEY_T key)
281 /* key: return session key */
282 {
283 int error = 0;
284
285 while ((nmp->nm_iflag & NFSMNT_WAITAUTH) == 0) {
286 nmp->nm_iflag |= NFSMNT_WANTAUTH;
287 (void) tsleep((void *)&nmp->nm_authtype, PSOCK,
288 "nfsauth1", 2 * hz);
289 error = nfs_sigintr(nmp, rep, rep->r_lwp);
290 if (error) {
291 nmp->nm_iflag &= ~NFSMNT_WANTAUTH;
292 return (error);
293 }
294 }
295 nmp->nm_iflag &= ~(NFSMNT_WAITAUTH | NFSMNT_WANTAUTH);
296 nmp->nm_authstr = *auth_str = (char *)malloc(RPCAUTH_MAXSIZ, M_TEMP, M_WAITOK);
297 nmp->nm_authlen = RPCAUTH_MAXSIZ;
298 nmp->nm_verfstr = verf_str;
299 nmp->nm_verflen = *verf_len;
300 nmp->nm_authuid = kauth_cred_geteuid(cred);
301 wakeup((void *)&nmp->nm_authstr);
302
303 /*
304 * And wait for mount_nfs to do its stuff.
305 */
306 while ((nmp->nm_iflag & NFSMNT_HASAUTH) == 0 && error == 0) {
307 (void) tsleep((void *)&nmp->nm_authlen, PSOCK,
308 "nfsauth2", 2 * hz);
309 error = nfs_sigintr(nmp, rep, rep->r_lwp);
310 }
311 if (nmp->nm_iflag & NFSMNT_AUTHERR) {
312 nmp->nm_iflag &= ~NFSMNT_AUTHERR;
313 error = EAUTH;
314 }
315 if (error)
316 free((void *)*auth_str, M_TEMP);
317 else {
318 *auth_len = nmp->nm_authlen;
319 *verf_len = nmp->nm_verflen;
320 memcpy(key, nmp->nm_key, sizeof (NFSKERBKEY_T));
321 }
322 nmp->nm_iflag &= ~NFSMNT_HASAUTH;
323 nmp->nm_iflag |= NFSMNT_WAITAUTH;
324 if (nmp->nm_iflag & NFSMNT_WANTAUTH) {
325 nmp->nm_iflag &= ~NFSMNT_WANTAUTH;
326 wakeup((void *)&nmp->nm_authtype);
327 }
328 return (error);
329 }
330
331 /*
332 * Get a nickname authenticator and verifier.
333 */
334 int
nfs_getnickauth(struct nfsmount * nmp,kauth_cred_t cred,char ** auth_str,int * auth_len,char * verf_str,int verf_len)335 nfs_getnickauth(struct nfsmount *nmp, kauth_cred_t cred, char **auth_str,
336 int *auth_len, char *verf_str, int verf_len)
337 {
338 #ifdef NFSKERB
339 struct timeval ktvin;
340 #endif
341 struct timeval ktvout, tv;
342 struct nfsuid *nuidp;
343 u_int32_t *nickp, *verfp;
344
345 memset(&ktvout, 0, sizeof ktvout); /* XXX gcc */
346
347 #ifdef DIAGNOSTIC
348 if (verf_len < (4 * NFSX_UNSIGNED))
349 panic("nfs_getnickauth verf too small");
350 #endif
351 LIST_FOREACH(nuidp, NMUIDHASH(nmp, kauth_cred_geteuid(cred)), nu_hash) {
352 if (kauth_cred_geteuid(nuidp->nu_cr) == kauth_cred_geteuid(cred))
353 break;
354 }
355 if (!nuidp || nuidp->nu_expire < time_second)
356 return (EACCES);
357
358 /*
359 * Move to the end of the lru list (end of lru == most recently used).
360 */
361 TAILQ_REMOVE(&nmp->nm_uidlruhead, nuidp, nu_lru);
362 TAILQ_INSERT_TAIL(&nmp->nm_uidlruhead, nuidp, nu_lru);
363
364 nickp = (u_int32_t *)malloc(2 * NFSX_UNSIGNED, M_TEMP, M_WAITOK);
365 *nickp++ = txdr_unsigned(RPCAKN_NICKNAME);
366 *nickp = txdr_unsigned(nuidp->nu_nickname);
367 *auth_str = (char *)nickp;
368 *auth_len = 2 * NFSX_UNSIGNED;
369
370 /*
371 * Now we must encrypt the verifier and package it up.
372 */
373 verfp = (u_int32_t *)verf_str;
374 *verfp++ = txdr_unsigned(RPCAKN_NICKNAME);
375 getmicrotime(&tv);
376 if (tv.tv_sec > nuidp->nu_timestamp.tv_sec ||
377 (tv.tv_sec == nuidp->nu_timestamp.tv_sec &&
378 tv.tv_usec > nuidp->nu_timestamp.tv_usec))
379 nuidp->nu_timestamp = tv;
380 else
381 nuidp->nu_timestamp.tv_usec++;
382 #ifdef NFSKERB
383 ktvin.tv_sec = txdr_unsigned(nuidp->nu_timestamp.tv_sec);
384 ktvin.tv_usec = txdr_unsigned(nuidp->nu_timestamp.tv_usec);
385
386 /*
387 * Now encrypt the timestamp verifier in ecb mode using the session
388 * key.
389 */
390 XXX
391 #endif
392
393 *verfp++ = ktvout.tv_sec;
394 *verfp++ = ktvout.tv_usec;
395 *verfp = 0;
396 return (0);
397 }
398
399 /*
400 * Save the current nickname in a hash list entry on the mount point.
401 */
402 int
nfs_savenickauth(struct nfsmount * nmp,kauth_cred_t cred,int len,NFSKERBKEY_T key,struct mbuf ** mdp,char ** dposp,struct mbuf * mrep)403 nfs_savenickauth(struct nfsmount *nmp, kauth_cred_t cred, int len, NFSKERBKEY_T key, struct mbuf **mdp, char **dposp, struct mbuf *mrep)
404 {
405 struct nfsuid *nuidp;
406 u_int32_t *tl;
407 int32_t t1;
408 struct mbuf *md = *mdp;
409 struct timeval ktvin, ktvout;
410 u_int32_t nick;
411 char *dpos = *dposp, *cp2;
412 time_t deltasec;
413 int error = 0;
414
415 memset(&ktvout, 0, sizeof ktvout); /* XXX gcc */
416
417 if (len == (3 * NFSX_UNSIGNED)) {
418 nfsm_dissect(tl, u_int32_t *, 3 * NFSX_UNSIGNED);
419 ktvin.tv_sec = *tl++;
420 ktvin.tv_usec = *tl++;
421 nick = fxdr_unsigned(u_int32_t, *tl);
422
423 /*
424 * Decrypt the timestamp in ecb mode.
425 */
426 #ifdef NFSKERB
427 XXX
428 #else
429 (void)ktvin.tv_sec;
430 #endif
431 ktvout.tv_sec = fxdr_unsigned(long, ktvout.tv_sec);
432 ktvout.tv_usec = fxdr_unsigned(long, ktvout.tv_usec);
433 deltasec = time_second - ktvout.tv_sec;
434 if (deltasec < 0)
435 deltasec = -deltasec;
436 /*
437 * If ok, add it to the hash list for the mount point.
438 */
439 if (deltasec <= NFS_KERBCLOCKSKEW) {
440 if (nmp->nm_numuids < nuidhash_max) {
441 nmp->nm_numuids++;
442 nuidp = kmem_alloc(sizeof(*nuidp), KM_SLEEP);
443 } else {
444 nuidp = TAILQ_FIRST(&nmp->nm_uidlruhead);
445 LIST_REMOVE(nuidp, nu_hash);
446 TAILQ_REMOVE(&nmp->nm_uidlruhead, nuidp,
447 nu_lru);
448 }
449 nuidp->nu_flag = 0;
450 kauth_cred_seteuid(nuidp->nu_cr, kauth_cred_geteuid(cred));
451 nuidp->nu_expire = time_second + NFS_KERBTTL;
452 nuidp->nu_timestamp = ktvout;
453 nuidp->nu_nickname = nick;
454 memcpy(nuidp->nu_key, key, sizeof (NFSKERBKEY_T));
455 TAILQ_INSERT_TAIL(&nmp->nm_uidlruhead, nuidp,
456 nu_lru);
457 LIST_INSERT_HEAD(NMUIDHASH(nmp, kauth_cred_geteuid(cred)),
458 nuidp, nu_hash);
459 }
460 } else
461 nfsm_adv(nfsm_rndup(len));
462 nfsmout:
463 *mdp = md;
464 *dposp = dpos;
465 return (error);
466 }
467