1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (c) 2022 Paulo Alcantara <palcantara@suse.de>
4 */
5
6 #ifndef _CIFS_DFS_H
7 #define _CIFS_DFS_H
8
9 #include "cifsglob.h"
10 #include "cifsproto.h"
11 #include "fs_context.h"
12 #include "dfs_cache.h"
13 #include "cifs_unicode.h"
14 #include <linux/namei.h>
15
16 #define DFS_INTERLINK(v) \
17 (((v) & DFSREF_REFERRAL_SERVER) && !((v) & DFSREF_STORAGE_SERVER))
18
19 struct dfs_ref {
20 char *path;
21 char *full_path;
22 struct dfs_cache_tgt_list tl;
23 struct dfs_cache_tgt_iterator *tit;
24 };
25
26 struct dfs_ref_walk {
27 struct dfs_ref *ref;
28 struct dfs_ref refs[MAX_NESTED_LINKS];
29 };
30
31 #define ref_walk_start(w) ((w)->refs)
32 #define ref_walk_end(w) (&(w)->refs[ARRAY_SIZE((w)->refs) - 1])
33 #define ref_walk_cur(w) ((w)->ref)
34 #define ref_walk_descend(w) (--ref_walk_cur(w) >= ref_walk_start(w))
35
36 #define ref_walk_tit(w) (ref_walk_cur(w)->tit)
37 #define ref_walk_empty(w) (!ref_walk_tit(w))
38 #define ref_walk_path(w) (ref_walk_cur(w)->path)
39 #define ref_walk_fpath(w) (ref_walk_cur(w)->full_path)
40 #define ref_walk_tl(w) (&ref_walk_cur(w)->tl)
41
42 static inline struct dfs_ref_walk *ref_walk_alloc(void)
43 {
44 struct dfs_ref_walk *rw;
45
46 rw = kmalloc(sizeof(*rw), GFP_KERNEL);
47 if (!rw)
48 return ERR_PTR(-ENOMEM);
49 return rw;
50 }
51
52 static inline void ref_walk_init(struct dfs_ref_walk *rw)
53 {
54 memset(rw, 0, sizeof(*rw));
55 ref_walk_cur(rw) = ref_walk_start(rw);
56 }
57
58 static inline void __ref_walk_free(struct dfs_ref *ref)
59 {
60 kfree(ref->path);
61 kfree(ref->full_path);
62 dfs_cache_free_tgts(&ref->tl);
63 memset(ref, 0, sizeof(*ref));
64 }
65
66 static inline void ref_walk_free(struct dfs_ref_walk *rw)
67 {
68 struct dfs_ref *ref = ref_walk_start(rw);
69
70 for (; ref <= ref_walk_end(rw); ref++)
71 __ref_walk_free(ref);
72 kfree(rw);
73 }
74
75 static inline int ref_walk_advance(struct dfs_ref_walk *rw)
76 {
77 struct dfs_ref *ref = ref_walk_cur(rw) + 1;
78
79 if (ref > ref_walk_end(rw))
80 return -ELOOP;
81 __ref_walk_free(ref);
82 ref_walk_cur(rw) = ref;
83 return 0;
84 }
85
86 static inline struct dfs_cache_tgt_iterator *
87 ref_walk_next_tgt(struct dfs_ref_walk *rw)
88 {
89 struct dfs_cache_tgt_iterator *tit;
90 struct dfs_ref *ref = ref_walk_cur(rw);
91
92 if (!ref->tit)
93 tit = dfs_cache_get_tgt_iterator(&ref->tl);
94 else
95 tit = dfs_cache_get_next_tgt(&ref->tl, ref->tit);
96 ref->tit = tit;
97 return tit;
98 }
99
100 static inline int ref_walk_get_tgt(struct dfs_ref_walk *rw,
101 struct dfs_info3_param *tgt)
102 {
103 zfree_dfs_info_param(tgt);
104 return dfs_cache_get_tgt_referral(ref_walk_path(rw) + 1,
105 ref_walk_tit(rw), tgt);
106 }
107
108 static inline int ref_walk_num_tgts(struct dfs_ref_walk *rw)
109 {
110 return dfs_cache_get_nr_tgts(ref_walk_tl(rw));
111 }
112
113 static inline void ref_walk_set_tgt_hint(struct dfs_ref_walk *rw)
114 {
115 dfs_cache_noreq_update_tgthint(ref_walk_path(rw) + 1,
116 ref_walk_tit(rw));
117 }
118
119 int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_param *ref,
120 struct smb3_fs_context *ctx);
121 int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs);
122
123 static inline char *dfs_get_path(struct cifs_sb_info *cifs_sb, const char *path)
124 {
125 return dfs_cache_canonical_path(path, cifs_sb->local_nls, cifs_remap(cifs_sb));
126 }
127
128 static inline int dfs_get_referral(struct cifs_mount_ctx *mnt_ctx, const char *path,
129 struct dfs_info3_param *ref, struct dfs_cache_tgt_list *tl)
130 {
131 struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
132 struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
133 struct cifs_ses *rses = ctx->dfs_root_ses ?: mnt_ctx->ses;
134
135 return dfs_cache_find(mnt_ctx->xid, rses, cifs_sb->local_nls,
136 cifs_remap(cifs_sb), path, ref, tl);
137 }
138
139 /*
140 * cifs_get_smb_ses() already guarantees an active reference of
141 * @ses->dfs_root_ses when a new session is created, so we need to put extra
142 * references of all DFS root sessions that were used across the mount process
143 * in dfs_mount_share().
144 */
145 static inline void dfs_put_root_smb_sessions(struct cifs_mount_ctx *mnt_ctx)
146 {
147 const struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
148 struct cifs_ses *ses = ctx->dfs_root_ses;
149 struct cifs_ses *cur;
150
151 if (!ses)
152 return;
153
154 for (cur = ses; cur; cur = cur->dfs_root_ses) {
155 if (cur->dfs_root_ses)
156 cifs_put_smb_ses(cur->dfs_root_ses);
157 }
158 cifs_put_smb_ses(ses);
159 }
160
161 #endif /* _CIFS_DFS_H */
162
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