xref: /kernel/linux/linux-6.6/fs/smb/client/dfs.h (revision 62306a36) 
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 "fs_context.h"
11#include "cifs_unicode.h"
12#include <linux/namei.h>
13
14#define DFS_INTERLINK(v) \
15	(((v) & DFSREF_REFERRAL_SERVER) && !((v) & DFSREF_STORAGE_SERVER))
16
17struct dfs_ref {
18	char *path;
19	char *full_path;
20	struct dfs_cache_tgt_list tl;
21	struct dfs_cache_tgt_iterator *tit;
22};
23
24struct dfs_ref_walk {
25	struct dfs_ref *ref;
26	struct dfs_ref refs[MAX_NESTED_LINKS];
27};
28
29#define ref_walk_start(w)	((w)->refs)
30#define ref_walk_end(w)	(&(w)->refs[ARRAY_SIZE((w)->refs) - 1])
31#define ref_walk_cur(w)	((w)->ref)
32#define ref_walk_descend(w)	(--ref_walk_cur(w) >= ref_walk_start(w))
33
34#define ref_walk_tit(w)	(ref_walk_cur(w)->tit)
35#define ref_walk_empty(w)	(!ref_walk_tit(w))
36#define ref_walk_path(w)	(ref_walk_cur(w)->path)
37#define ref_walk_fpath(w)	(ref_walk_cur(w)->full_path)
38#define ref_walk_tl(w)		(&ref_walk_cur(w)->tl)
39
40static inline struct dfs_ref_walk *ref_walk_alloc(void)
41{
42	struct dfs_ref_walk *rw;
43
44	rw = kmalloc(sizeof(*rw), GFP_KERNEL);
45	if (!rw)
46		return ERR_PTR(-ENOMEM);
47	return rw;
48}
49
50static inline void ref_walk_init(struct dfs_ref_walk *rw)
51{
52	memset(rw, 0, sizeof(*rw));
53	ref_walk_cur(rw) = ref_walk_start(rw);
54}
55
56static inline void __ref_walk_free(struct dfs_ref *ref)
57{
58	kfree(ref->path);
59	kfree(ref->full_path);
60	dfs_cache_free_tgts(&ref->tl);
61	memset(ref, 0, sizeof(*ref));
62}
63
64static inline void ref_walk_free(struct dfs_ref_walk *rw)
65{
66	struct dfs_ref *ref = ref_walk_start(rw);
67
68	for (; ref <= ref_walk_end(rw); ref++)
69		__ref_walk_free(ref);
70	kfree(rw);
71}
72
73static inline int ref_walk_advance(struct dfs_ref_walk *rw)
74{
75	struct dfs_ref *ref = ref_walk_cur(rw) + 1;
76
77	if (ref > ref_walk_end(rw))
78		return -ELOOP;
79	__ref_walk_free(ref);
80	ref_walk_cur(rw) = ref;
81	return 0;
82}
83
84static inline struct dfs_cache_tgt_iterator *
85ref_walk_next_tgt(struct dfs_ref_walk *rw)
86{
87	struct dfs_cache_tgt_iterator *tit;
88	struct dfs_ref *ref = ref_walk_cur(rw);
89
90	if (!ref->tit)
91		tit = dfs_cache_get_tgt_iterator(&ref->tl);
92	else
93		tit = dfs_cache_get_next_tgt(&ref->tl, ref->tit);
94	ref->tit = tit;
95	return tit;
96}
97
98static inline int ref_walk_get_tgt(struct dfs_ref_walk *rw,
99				   struct dfs_info3_param *tgt)
100{
101	zfree_dfs_info_param(tgt);
102	return dfs_cache_get_tgt_referral(ref_walk_path(rw) + 1,
103					  ref_walk_tit(rw), tgt);
104}
105
106static inline int ref_walk_num_tgts(struct dfs_ref_walk *rw)
107{
108	return dfs_cache_get_nr_tgts(ref_walk_tl(rw));
109}
110
111static inline void ref_walk_set_tgt_hint(struct dfs_ref_walk *rw)
112{
113	dfs_cache_noreq_update_tgthint(ref_walk_path(rw) + 1,
114				       ref_walk_tit(rw));
115}
116
117struct dfs_root_ses {
118	struct list_head list;
119	struct cifs_ses *ses;
120};
121
122int dfs_parse_target_referral(const char *full_path, const struct dfs_info3_param *ref,
123			      struct smb3_fs_context *ctx);
124int dfs_mount_share(struct cifs_mount_ctx *mnt_ctx, bool *isdfs);
125
126static inline char *dfs_get_path(struct cifs_sb_info *cifs_sb, const char *path)
127{
128	return dfs_cache_canonical_path(path, cifs_sb->local_nls, cifs_remap(cifs_sb));
129}
130
131static inline int dfs_get_referral(struct cifs_mount_ctx *mnt_ctx, const char *path,
132				   struct dfs_info3_param *ref, struct dfs_cache_tgt_list *tl)
133{
134	struct smb3_fs_context *ctx = mnt_ctx->fs_ctx;
135	struct cifs_sb_info *cifs_sb = mnt_ctx->cifs_sb;
136
137	return dfs_cache_find(mnt_ctx->xid, ctx->dfs_root_ses, cifs_sb->local_nls,
138			      cifs_remap(cifs_sb), path, ref, tl);
139}
140
141static inline void dfs_put_root_smb_sessions(struct list_head *head)
142{
143	struct dfs_root_ses *root, *tmp;
144
145	list_for_each_entry_safe(root, tmp, head, list) {
146		list_del_init(&root->list);
147		cifs_put_smb_ses(root->ses);
148		kfree(root);
149	}
150}
151
152#endif /* _CIFS_DFS_H */
153