fs/smb/client/dfs.h

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