1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * linux/fs/lockd/svcshare.c |
4 | * |
5 | * Management of DOS shares. |
6 | * |
7 | * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de> |
8 | */ |
9 | |
10 | #include <linux/time.h> |
11 | #include <linux/unistd.h> |
12 | #include <linux/string.h> |
13 | #include <linux/slab.h> |
14 | |
15 | #include <linux/sunrpc/clnt.h> |
16 | #include <linux/sunrpc/svc.h> |
17 | #include <linux/lockd/lockd.h> |
18 | #include <linux/lockd/share.h> |
19 | |
20 | static inline int |
21 | nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh) |
22 | { |
23 | return share->s_owner.len == oh->len |
24 | && !memcmp(p: share->s_owner.data, q: oh->data, size: oh->len); |
25 | } |
26 | |
27 | __be32 |
28 | nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file, |
29 | struct nlm_args *argp) |
30 | { |
31 | struct nlm_share *share; |
32 | struct xdr_netobj *oh = &argp->lock.oh; |
33 | u8 *ohdata; |
34 | |
35 | for (share = file->f_shares; share; share = share->s_next) { |
36 | if (share->s_host == host && nlm_cmp_owner(share, oh)) |
37 | goto update; |
38 | if ((argp->fsm_access & share->s_mode) |
39 | || (argp->fsm_mode & share->s_access )) |
40 | return nlm_lck_denied; |
41 | } |
42 | |
43 | share = kmalloc(size: sizeof(*share) + oh->len, |
44 | GFP_KERNEL); |
45 | if (share == NULL) |
46 | return nlm_lck_denied_nolocks; |
47 | |
48 | /* Copy owner handle */ |
49 | ohdata = (u8 *) (share + 1); |
50 | memcpy(ohdata, oh->data, oh->len); |
51 | |
52 | share->s_file = file; |
53 | share->s_host = host; |
54 | share->s_owner.data = ohdata; |
55 | share->s_owner.len = oh->len; |
56 | share->s_next = file->f_shares; |
57 | file->f_shares = share; |
58 | |
59 | update: |
60 | share->s_access = argp->fsm_access; |
61 | share->s_mode = argp->fsm_mode; |
62 | return nlm_granted; |
63 | } |
64 | |
65 | /* |
66 | * Delete a share. |
67 | */ |
68 | __be32 |
69 | nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file, |
70 | struct nlm_args *argp) |
71 | { |
72 | struct nlm_share *share, **shpp; |
73 | struct xdr_netobj *oh = &argp->lock.oh; |
74 | |
75 | for (shpp = &file->f_shares; (share = *shpp) != NULL; |
76 | shpp = &share->s_next) { |
77 | if (share->s_host == host && nlm_cmp_owner(share, oh)) { |
78 | *shpp = share->s_next; |
79 | kfree(objp: share); |
80 | return nlm_granted; |
81 | } |
82 | } |
83 | |
84 | /* X/Open spec says return success even if there was no |
85 | * corresponding share. */ |
86 | return nlm_granted; |
87 | } |
88 | |
89 | /* |
90 | * Traverse all shares for a given file, and delete |
91 | * those owned by the given (type of) host |
92 | */ |
93 | void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file, |
94 | nlm_host_match_fn_t match) |
95 | { |
96 | struct nlm_share *share, **shpp; |
97 | |
98 | shpp = &file->f_shares; |
99 | while ((share = *shpp) != NULL) { |
100 | if (match(share->s_host, host)) { |
101 | *shpp = share->s_next; |
102 | kfree(objp: share); |
103 | continue; |
104 | } |
105 | shpp = &share->s_next; |
106 | } |
107 | } |
108 | |