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 #include <linux/errno.h>
16
17 #define DFS_INTERLINK(v) \
18 (((v) & DFSREF_REFERRAL_SERVER) && !((v) & DFSREF_STORAGE_SERVER))
19
20 struct dfs_ref {
21 char *path;
22 char *full_path;
23 struct cifs_ses *ses;
24 struct dfs_cache_tgt_list tl;
25 struct dfs_cache_tgt_iterator *tit;
26 };
27
28 struct dfs_ref_walk {
29 struct cifs_mount_ctx *mnt_ctx;
30 struct dfs_ref *ref;
31 struct dfs_ref refs[MAX_NESTED_LINKS];
32 };
33
34 #define ref_walk_start(w) ((w)->refs)
35 #define ref_walk_end(w) (&(w)->refs[ARRAY_SIZE((w)->refs) - 1])
36 #define ref_walk_cur(w) ((w)->ref)
37 #define ref_walk_descend(w) (--ref_walk_cur(w) >= ref_walk_start(w))
38
39 #define ref_walk_tit(w) (ref_walk_cur(w)->tit)
40 #define ref_walk_path(w) (ref_walk_cur(w)->path)
41 #define ref_walk_fpath(w) (ref_walk_cur(w)->full_path)
42 #define ref_walk_tl(w) (&ref_walk_cur(w)->tl)
43 #define ref_walk_ses(w) (ref_walk_cur(w)->ses)
44
ref_walk_alloc(void)45 static inline struct dfs_ref_walk *ref_walk_alloc(void)
46 {
47 struct dfs_ref_walk *rw;
48
49 rw = kmalloc(sizeof(*rw), GFP_KERNEL);
50 if (!rw)
51 return ERR_PTR(-ENOMEM);
52 return rw;
53 }
54
ref_walk_init(struct dfs_ref_walk * rw,struct cifs_mount_ctx * mnt_ctx)55 static inline void ref_walk_init(struct dfs_ref_walk *rw,
56 struct cifs_mount_ctx *mnt_ctx)
57 {
58 memset(rw, 0, sizeof(*rw));
59 rw->mnt_ctx = mnt_ctx;
60 ref_walk_cur(rw) = ref_walk_start(rw);
61 }
62
__ref_walk_free(struct dfs_ref * ref)63 static inline void __ref_walk_free(struct dfs_ref *ref)
64 {
65 kfree(ref->path);
66 kfree(ref->full_path);
67 dfs_cache_free_tgts(&ref->tl);
68 if (ref->ses)
69 cifs_put_smb_ses(ref->ses);
70 memset(ref, 0, sizeof(*ref));
71 }
72
ref_walk_free(struct dfs_ref_walk * rw)73 static inline void ref_walk_free(struct dfs_ref_walk *rw)
74 {
75 struct dfs_ref *ref;
76
77 if (!rw)
78 return;
79
80 for (ref = ref_walk_start(rw); ref <= ref_walk_end(rw); ref++)
81 __ref_walk_free(ref);
82 kfree(rw);
83 }
84
ref_walk_advance(struct dfs_ref_walk * rw)85 static inline int ref_walk_advance(struct dfs_ref_walk *rw)
86 {
87 struct dfs_ref *ref = ref_walk_cur(rw) + 1;
88
89 if (ref > ref_walk_end(rw))
90 return -ELOOP;
91 __ref_walk_free(ref);
92 ref_walk_cur(rw) = ref;
93 return 0;
94 }
95
96 static inline struct dfs_cache_tgt_iterator *
ref_walk_next_tgt(struct dfs_ref_walk * rw)97 ref_walk_next_tgt(struct dfs_ref_walk *rw)
98 {
99 struct dfs_ref *ref = ref_walk_cur(rw);
100 struct dfs_cache_tgt_iterator *tit;
101
102 if (IS_ERR(ref->tit))
103 return NULL;
104
105 if (!ref->tit)
106 tit = dfs_cache_get_tgt_iterator(&ref->tl);
107 else
108 tit = dfs_cache_get_next_tgt(&ref->tl, ref->tit);
109
110 if (!tit) {
111 ref->tit = ERR_PTR(-ENOENT);
112 return NULL;
113 }
114 ref->tit = tit;
115 return ref->tit;
116 }
117
ref_walk_get_tgt(struct dfs_ref_walk * rw,struct dfs_info3_param * tgt)118 static inline int ref_walk_get_tgt(struct dfs_ref_walk *rw,
119 struct dfs_info3_param *tgt)
120 {
121 zfree_dfs_info_param(tgt);
122 return dfs_cache_get_tgt_referral(ref_walk_path(rw) + 1,
123 ref_walk_tit(rw), tgt);
124 }
125
ref_walk_set_tgt_hint(struct dfs_ref_walk * rw)126 static inline void ref_walk_set_tgt_hint(struct dfs_ref_walk *rw)
127 {
128 dfs_cache_noreq_update_tgthint(ref_walk_path(rw) + 1,
129 ref_walk_tit(rw));
130 }
131
ref_walk_set_tcon(struct dfs_ref_walk * rw,struct cifs_tcon * tcon)132 static inline void ref_walk_set_tcon(struct dfs_ref_walk *rw,
133 struct cifs_tcon *tcon)
134 {
135 struct dfs_ref *ref = ref_walk_start(rw);
136
137 for (; ref <= ref_walk_cur(rw); ref++) {
138 if (WARN_ON_ONCE(!ref->ses))
139 continue;
140 list_add(&ref->ses->dlist, &tcon->dfs_ses_list);
141 ref->ses = NULL;
142 }
143 }
144
ref_walk_mark_end(struct dfs_ref_walk * rw)145 static inline void ref_walk_mark_end(struct dfs_ref_walk *rw)
146 {
147 struct dfs_ref *ref = ref_walk_cur(rw) - 1;
148
149 WARN_ON_ONCE(ref < ref_walk_start(rw));
150 dfs_cache_noreq_update_tgthint(ref->path + 1, ref->tit);
151 ref->tit = ERR_PTR(-ENOENT); /* end marker */
152 }
153
154 int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_param *ref,
155 struct smb3_fs_context *ctx);
156 int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx);
157
dfs_get_path(struct cifs_sb_info * cifs_sb,const char * path)158 static inline char *dfs_get_path(struct cifs_sb_info *cifs_sb, const char *path)
159 {
160 return dfs_cache_canonical_path(path, cifs_sb->local_nls, cifs_remap(cifs_sb));
161 }
162
dfs_get_referral(struct cifs_mount_ctx * mnt_ctx,const char * path,struct dfs_cache_tgt_list * tl)163 static inline int dfs_get_referral(struct cifs_mount_ctx *mnt_ctx,
164 const char *path,
165 struct dfs_cache_tgt_list *tl)
166 {
167 struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
168 struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
169 struct cifs_ses *rses = ctx->dfs_root_ses ?: mnt_ctx->ses;
170
171 return dfs_cache_find(mnt_ctx->xid, rses, cifs_sb->local_nls,
172 cifs_remap(cifs_sb), path, NULL, tl);
173 }
174
175 /*
176 * cifs_get_smb_ses() already guarantees an active reference of
177 * @ses->dfs_root_ses when a new session is created, so we need to put extra
178 * references of all DFS root sessions that were used across the mount process
179 * in dfs_mount_share().
180 */
dfs_put_root_smb_sessions(struct list_head * head)181 static inline void dfs_put_root_smb_sessions(struct list_head *head)
182 {
183 struct cifs_ses *ses, *n;
184
185 list_for_each_entry_safe(ses, n, head, dlist) {
186 list_del_init(&ses->dlist);
187 cifs_put_smb_ses(ses);
188 }
189 }
190
dfs_ses_refpath(struct cifs_ses * ses)191 static inline const char *dfs_ses_refpath(struct cifs_ses *ses)
192 {
193 const char *path = ses->server->leaf_fullpath;
194
195 return path ? path + 1 : ERR_PTR(-ENOENT);
196 }
197
198 #endif /* _CIFS_DFS_H */
199