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      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
     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
    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
    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
    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
    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
    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
    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
    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