xref: /linux/fs/nfsd/lockd.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This file contains all the stubs needed when communicating with lockd.
4  * This level of indirection is necessary so we can run nfsd+lockd without
5  * requiring the nfs client to be compiled in/loaded, and vice versa.
6  *
7  * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8  */
9 
10 #include <linux/file.h>
11 #include <linux/lockd/bind.h>
12 #include "nfsd.h"
13 #include "vfs.h"
14 
15 #define NFSDDBG_FACILITY		NFSDDBG_LOCKD
16 
17 #ifdef CONFIG_LOCKD_V4
18 #define nlm_stale_fh	nlm4_stale_fh
19 #define nlm_failed	nlm4_failed
20 #else
21 #define nlm_stale_fh	nlm_lck_denied_nolocks
22 #define nlm_failed	nlm_lck_denied_nolocks
23 #endif
24 /*
25  * Note: we hold the dentry use count while the file is open.
26  */
27 static __be32
28 nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp,
29 		int mode)
30 {
31 	__be32		nfserr;
32 	int		access;
33 	struct svc_fh	fh;
34 
35 	/* must initialize before using! but maxsize doesn't matter */
36 	fh_init(&fh,0);
37 	fh.fh_handle.fh_size = f->size;
38 	memcpy(&fh.fh_handle.fh_raw, f->data, f->size);
39 	fh.fh_export = NULL;
40 
41 	/*
42 	 * Allow BYPASS_GSS as some client implementations use AUTH_SYS
43 	 * for NLM even when GSS is used for NFS.
44 	 * Allow OWNER_OVERRIDE as permission might have been changed
45 	 * after the file was opened.
46 	 * Pass MAY_NLM so that authentication can be completely bypassed
47 	 * if NFSEXP_NOAUTHNLM is set.  Some older clients use AUTH_NULL
48 	 * for NLM requests.
49 	 */
50 	access = (mode == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ;
51 	access |= NFSD_MAY_NLM | NFSD_MAY_OWNER_OVERRIDE | NFSD_MAY_BYPASS_GSS;
52 	nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp);
53 	fh_put(&fh);
54 	/* We return nlm error codes as nlm doesn't know
55 	 * about nfsd, but nfsd does know about nlm..
56 	 */
57 	switch (nfserr) {
58 	case nfs_ok:
59 		return 0;
60 	case nfserr_dropit:
61 		return nlm_drop_reply;
62 	case nfserr_stale:
63 		return nlm_stale_fh;
64 	default:
65 		return nlm_failed;
66 	}
67 }
68 
69 static void
70 nlm_fclose(struct file *filp)
71 {
72 	fput(filp);
73 }
74 
75 static const struct nlmsvc_binding nfsd_nlm_ops = {
76 	.fopen		= nlm_fopen,		/* open file for locking */
77 	.fclose		= nlm_fclose,		/* close file */
78 };
79 
80 void
81 nfsd_lockd_init(void)
82 {
83 	dprintk("nfsd: initializing lockd\n");
84 	nlmsvc_ops = &nfsd_nlm_ops;
85 }
86 
87 void
88 nfsd_lockd_shutdown(void)
89 {
90 	nlmsvc_ops = NULL;
91 }
92