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  1. /*-
  2. * SPDX-License-Identifier: BSD-3-Clause
  3. *
  4. * Copyright (c) 1997 Berkeley Software Design, Inc. All rights reserved.
  5. *
  6. * Redistribution and use in source and binary forms, with or without
  7. * modification, are permitted provided that the following conditions
  8. * are met:
  9. * 1. Redistributions of source code must retain the above copyright
  10. * notice, this list of conditions and the following disclaimer.
  11. * 2. Redistributions in binary form must reproduce the above copyright
  12. * notice, this list of conditions and the following disclaimer in the
  13. * documentation and/or other materials provided with the distribution.
  14. * 3. Berkeley Software Design Inc's name may not be used to endorse or
  15. * promote products derived from this software without specific prior
  16. * written permission.
  17. *
  18. * THIS SOFTWARE IS PROVIDED BY BERKELEY SOFTWARE DESIGN INC ``AS IS'' AND
  19. * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20. * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21. * ARE DISCLAIMED. IN NO EVENT SHALL BERKELEY SOFTWARE DESIGN INC BE LIABLE
  22. * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23. * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24. * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25. * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26. * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27. * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28. * SUCH DAMAGE.
  29. *
  30. * from BSDI nfs_lock.c,v 2.4 1998/12/14 23:49:56 jch Exp
  31. */
  32. #include <sys/cdefs.h>
  33. __FBSDID("$FreeBSD$");
  34. #include <sys/param.h>
  35. #include <sys/systm.h>
  36. #include <sys/conf.h>
  37. #include <sys/fcntl.h>
  38. #include <sys/kernel.h> /* for hz */
  39. #include <sys/limits.h>
  40. #include <sys/lock.h>
  41. #include <sys/malloc.h>
  42. #include <sys/lockf.h> /* for hz */ /* Must come after sys/malloc.h */
  43. #include <sys/mbuf.h>
  44. #include <sys/mount.h>
  45. #include <sys/namei.h>
  46. #include <sys/priv.h>
  47. #include <sys/proc.h>
  48. #include <sys/resourcevar.h>
  49. #include <sys/socket.h>
  50. #include <sys/socket.h>
  51. #include <sys/unistd.h>
  52. #include <sys/vnode.h>
  53. #include <net/if.h>
  54. #include <nfs/nfsproto.h>
  55. #include <nfs/nfs_lock.h>
  56. #include <nfsclient/nfs.h>
  57. #include <nfsclient/nfsmount.h>
  58. #include <nfsclient/nfsnode.h>
  59. #include <nfsclient/nlminfo.h>
  60. extern void (*nlminfo_release_p)(struct proc *p);
  61. vop_advlock_t *nfs_advlock_p = nfs_dolock;
  62. vop_reclaim_t *nfs_reclaim_p = NULL;
  63. static MALLOC_DEFINE(M_NFSLOCK, "nfsclient_lock", "NFS lock request");
  64. static MALLOC_DEFINE(M_NLMINFO, "nfsclient_nlminfo",
  65. "NFS lock process structure");
  66. static int nfslockdans(struct thread *td, struct lockd_ans *ansp);
  67. static void nlminfo_release(struct proc *p);
  68. /*
  69. * --------------------------------------------------------------------
  70. * A miniature device driver which the userland uses to talk to us.
  71. *
  72. */
  73. static struct cdev *nfslock_dev;
  74. static struct mtx nfslock_mtx;
  75. static int nfslock_isopen;
  76. static TAILQ_HEAD(,__lock_msg) nfslock_list;
  77. static int
  78. nfslock_open(struct cdev *dev, int oflags, int devtype, struct thread *td)
  79. {
  80. int error;
  81. gone_in(13, "uses Giant; replace with NFSLOCKD/nfslockd.ko");
  82. error = priv_check(td, PRIV_NFS_LOCKD);
  83. if (error)
  84. return (error);
  85. mtx_lock(&nfslock_mtx);
  86. if (!nfslock_isopen) {
  87. error = 0;
  88. nfslock_isopen = 1;
  89. } else {
  90. error = EOPNOTSUPP;
  91. }
  92. mtx_unlock(&nfslock_mtx);
  93. return (error);
  94. }
  95. static int
  96. nfslock_close(struct cdev *dev, int fflag, int devtype, struct thread *td)
  97. {
  98. struct __lock_msg *lm;
  99. mtx_lock(&nfslock_mtx);
  100. nfslock_isopen = 0;
  101. while (!TAILQ_EMPTY(&nfslock_list)) {
  102. lm = TAILQ_FIRST(&nfslock_list);
  103. /* XXX: answer request */
  104. TAILQ_REMOVE(&nfslock_list, lm, lm_link);
  105. free(lm, M_NFSLOCK);
  106. }
  107. mtx_unlock(&nfslock_mtx);
  108. return (0);
  109. }
  110. static int
  111. nfslock_read(struct cdev *dev, struct uio *uio, int ioflag)
  112. {
  113. int error;
  114. struct __lock_msg *lm;
  115. if (uio->uio_resid != sizeof *lm)
  116. return (EOPNOTSUPP);
  117. lm = NULL;
  118. error = 0;
  119. mtx_lock(&nfslock_mtx);
  120. while (TAILQ_EMPTY(&nfslock_list)) {
  121. error = msleep(&nfslock_list, &nfslock_mtx, PSOCK | PCATCH,
  122. "nfslockd", 0);
  123. if (error)
  124. break;
  125. }
  126. if (!error) {
  127. lm = TAILQ_FIRST(&nfslock_list);
  128. TAILQ_REMOVE(&nfslock_list, lm, lm_link);
  129. }
  130. mtx_unlock(&nfslock_mtx);
  131. if (!error) {
  132. error = uiomove(lm, sizeof *lm, uio);
  133. free(lm, M_NFSLOCK);
  134. }
  135. return (error);
  136. }
  137. static int
  138. nfslock_write(struct cdev *dev, struct uio *uio, int ioflag)
  139. {
  140. struct lockd_ans la;
  141. int error;
  142. if (uio->uio_resid != sizeof la)
  143. return (EOPNOTSUPP);
  144. error = uiomove(&la, sizeof la, uio);
  145. if (!error)
  146. error = nfslockdans(curthread, &la);
  147. return (error);
  148. }
  149. static int
  150. nfslock_send(struct __lock_msg *lm)
  151. {
  152. struct __lock_msg *lm2;
  153. int error;
  154. error = 0;
  155. lm2 = malloc(sizeof *lm2, M_NFSLOCK, M_WAITOK);
  156. mtx_lock(&nfslock_mtx);
  157. if (nfslock_isopen) {
  158. memcpy(lm2, lm, sizeof *lm2);
  159. TAILQ_INSERT_TAIL(&nfslock_list, lm2, lm_link);
  160. wakeup(&nfslock_list);
  161. } else {
  162. error = EOPNOTSUPP;
  163. }
  164. mtx_unlock(&nfslock_mtx);
  165. if (error)
  166. free(lm2, M_NFSLOCK);
  167. return (error);
  168. }
  169. static struct cdevsw nfslock_cdevsw = {
  170. .d_version = D_VERSION,
  171. .d_open = nfslock_open,
  172. .d_close = nfslock_close,
  173. .d_read = nfslock_read,
  174. .d_write = nfslock_write,
  175. .d_name = "nfslock"
  176. };
  177. static int
  178. nfslock_modevent(module_t mod __unused, int type, void *data __unused)
  179. {
  180. switch (type) {
  181. case MOD_LOAD:
  182. if (bootverbose)
  183. printf("nfslock: pseudo-device\n");
  184. mtx_init(&nfslock_mtx, "nfslock", NULL, MTX_DEF);
  185. TAILQ_INIT(&nfslock_list);
  186. nlminfo_release_p = nlminfo_release;
  187. nfslock_dev = make_dev(&nfslock_cdevsw, 0,
  188. UID_ROOT, GID_KMEM, 0600, _PATH_NFSLCKDEV);
  189. return (0);
  190. default:
  191. return (EOPNOTSUPP);
  192. }
  193. }
  194. DEV_MODULE(nfslock, nfslock_modevent, NULL);
  195. MODULE_VERSION(nfslock, 1);
  196. /*
  197. * XXX
  198. * We have to let the process know if the call succeeded. I'm using an extra
  199. * field in the p_nlminfo field in the proc structure, as it is already for
  200. * lockd stuff.
  201. */
  202. /*
  203. * nfs_advlock --
  204. * NFS advisory byte-level locks.
  205. *
  206. * The vnode shall be (shared) locked on the entry, it is
  207. * unconditionally unlocked after.
  208. */
  209. int
  210. nfs_dolock(struct vop_advlock_args *ap)
  211. {
  212. LOCKD_MSG msg;
  213. struct thread *td;
  214. struct vnode *vp;
  215. int error;
  216. struct flock *fl;
  217. struct proc *p;
  218. struct nfsmount *nmp;
  219. struct timeval boottime;
  220. td = curthread;
  221. p = td->td_proc;
  222. vp = ap->a_vp;
  223. fl = ap->a_fl;
  224. nmp = VFSTONFS(vp->v_mount);
  225. ASSERT_VOP_LOCKED(vp, "nfs_dolock");
  226. nmp->nm_getinfo(vp, msg.lm_fh, &msg.lm_fh_len, &msg.lm_addr,
  227. &msg.lm_nfsv3, NULL, NULL);
  228. VOP_UNLOCK(vp, 0);
  229. /*
  230. * the NLM protocol doesn't allow the server to return an error
  231. * on ranges, so we do it.
  232. */
  233. if (fl->l_whence != SEEK_END) {
  234. if ((fl->l_whence != SEEK_CUR && fl->l_whence != SEEK_SET) ||
  235. fl->l_start < 0 ||
  236. (fl->l_len < 0 &&
  237. (fl->l_start == 0 || fl->l_start + fl->l_len < 0)))
  238. return (EINVAL);
  239. if (fl->l_len > 0 &&
  240. (fl->l_len - 1 > OFF_MAX - fl->l_start))
  241. return (EOVERFLOW);
  242. }
  243. /*
  244. * Fill in the information structure.
  245. */
  246. msg.lm_version = LOCKD_MSG_VERSION;
  247. msg.lm_msg_ident.pid = p->p_pid;
  248. mtx_lock(&Giant);
  249. /*
  250. * if there is no nfsowner table yet, allocate one.
  251. */
  252. if (p->p_nlminfo == NULL) {
  253. p->p_nlminfo = malloc(sizeof(struct nlminfo),
  254. M_NLMINFO, M_WAITOK | M_ZERO);
  255. p->p_nlminfo->pid_start = p->p_stats->p_start;
  256. getboottime(&boottime);
  257. timevaladd(&p->p_nlminfo->pid_start, &boottime);
  258. }
  259. msg.lm_msg_ident.pid_start = p->p_nlminfo->pid_start;
  260. msg.lm_msg_ident.msg_seq = ++(p->p_nlminfo->msg_seq);
  261. msg.lm_fl = *fl;
  262. msg.lm_wait = ap->a_flags & F_WAIT;
  263. msg.lm_getlk = ap->a_op == F_GETLK;
  264. cru2x(td->td_ucred, &msg.lm_cred);
  265. for (;;) {
  266. error = nfslock_send(&msg);
  267. if (error)
  268. goto out;
  269. /* Unlocks succeed immediately. */
  270. if (fl->l_type == F_UNLCK)
  271. goto out;
  272. /*
  273. * Retry after 20 seconds if we haven't gotten a response yet.
  274. * This number was picked out of thin air... but is longer
  275. * then even a reasonably loaded system should take (at least
  276. * on a local network). XXX Probably should use a back-off
  277. * scheme.
  278. *
  279. * XXX: No PCATCH here since we currently have no useful
  280. * way to signal to the userland rpc.lockd that the request
  281. * has been aborted. Once the rpc.lockd implementation
  282. * can handle aborts, and we report them properly,
  283. * PCATCH can be put back. In the mean time, if we did
  284. * permit aborting, the lock attempt would "get lost"
  285. * and the lock would get stuck in the locked state.
  286. */
  287. error = tsleep(p->p_nlminfo, PUSER, "lockd", 20*hz);
  288. if (error != 0) {
  289. if (error == EWOULDBLOCK) {
  290. /*
  291. * We timed out, so we rewrite the request
  292. * to the fifo.
  293. */
  294. continue;
  295. }
  296. break;
  297. }
  298. if (msg.lm_getlk && p->p_nlminfo->retcode == 0) {
  299. if (p->p_nlminfo->set_getlk_pid) {
  300. fl->l_sysid = 0; /* XXX */
  301. fl->l_pid = p->p_nlminfo->getlk_pid;
  302. } else {
  303. fl->l_type = F_UNLCK;
  304. }
  305. }
  306. error = p->p_nlminfo->retcode;
  307. break;
  308. }
  309. out:
  310. mtx_unlock(&Giant);
  311. return (error);
  312. }
  313. /*
  314. * nfslockdans --
  315. * NFS advisory byte-level locks answer from the lock daemon.
  316. */
  317. static int
  318. nfslockdans(struct thread *td, struct lockd_ans *ansp)
  319. {
  320. struct proc *targetp;
  321. /* the version should match, or we're out of sync */
  322. if (ansp->la_vers != LOCKD_ANS_VERSION)
  323. return (EINVAL);
  324. /* Find the process, set its return errno and wake it up. */
  325. if ((targetp = pfind(ansp->la_msg_ident.pid)) == NULL)
  326. return (ESRCH);
  327. /* verify the pid hasn't been reused (if we can), and it isn't waiting
  328. * for an answer from a more recent request. We return an EPIPE if
  329. * the match fails, because we've already used ESRCH above, and this
  330. * is sort of like writing on a pipe after the reader has closed it.
  331. */
  332. if (targetp->p_nlminfo == NULL ||
  333. ((ansp->la_msg_ident.msg_seq != -1) &&
  334. (timevalcmp(&targetp->p_nlminfo->pid_start,
  335. &ansp->la_msg_ident.pid_start, !=) ||
  336. targetp->p_nlminfo->msg_seq != ansp->la_msg_ident.msg_seq))) {
  337. PROC_UNLOCK(targetp);
  338. return (EPIPE);
  339. }
  340. targetp->p_nlminfo->retcode = ansp->la_errno;
  341. targetp->p_nlminfo->set_getlk_pid = ansp->la_set_getlk_pid;
  342. targetp->p_nlminfo->getlk_pid = ansp->la_getlk_pid;
  343. wakeup(targetp->p_nlminfo);
  344. PROC_UNLOCK(targetp);
  345. return (0);
  346. }
  347. /*
  348. * Free nlminfo attached to process.
  349. */
  350. void
  351. nlminfo_release(struct proc *p)
  352. {
  353. free(p->p_nlminfo, M_NLMINFO);
  354. p->p_nlminfo = NULL;
  355. }