Line data Source code
1 : /*
2 : * ID Mapping Plugin interface for cifs-utils
3 : * Copyright (C) 2012 Jeff Layton (jlayton@samba.org)
4 : *
5 : * This program is free software; you can redistribute it and/or modify
6 : * it under the terms of the GNU General Public License as published by
7 : * the Free Software Foundation; either version 3 of the License, or
8 : * (at your option) any later version.
9 : *
10 : * This program is distributed in the hope that it will be useful,
11 : * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 : * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 : * GNU General Public License for more details.
14 : *
15 : * You should have received a copy of the GNU General Public License
16 : * along with this program. If not, see <http://www.gnu.org/licenses/>.
17 : */
18 : #include <stdint.h>
19 :
20 : #ifndef _CIFSIDMAP_H
21 : #define _CIFSIDMAP_H
22 :
23 : #define NUM_AUTHS (6) /* number of authority fields */
24 : #define SID_MAX_SUB_AUTHORITIES (15) /* max number of sub authority fields */
25 :
26 : /*
27 : * Binary representation of a SID as presented to/from the kernel. Note that
28 : * the sub_auth field is always stored in little-endian here.
29 : */
30 : struct cifs_sid {
31 : uint8_t revision; /* revision level */
32 : uint8_t num_subauth;
33 : uint8_t authority[NUM_AUTHS];
34 : uint32_t sub_auth[SID_MAX_SUB_AUTHORITIES];
35 : } __attribute__((packed));
36 :
37 :
38 : /*
39 : * The type of the ID stored within cifs_uxid. UNKNOWN generally means that
40 : * the mapping failed for some reason. BOTH means that the ID is usable as
41 : * either a UID or a GID -- IOW, the UID and GID namespaces are unity-mapped.
42 : */
43 : #define CIFS_UXID_TYPE_UNKNOWN (0) /* mapping type is unknown */
44 : #define CIFS_UXID_TYPE_UID (1) /* mapping is a UID */
45 : #define CIFS_UXID_TYPE_GID (2) /* mapping is a GID */
46 : #define CIFS_UXID_TYPE_BOTH (3) /* usable as UID or GID */
47 :
48 : /* This struct represents a uid or gid and its type */
49 : struct cifs_uxid {
50 : union {
51 : uid_t uid;
52 : gid_t gid;
53 : } id;
54 : unsigned char type;
55 : } __attribute__((packed));
56 :
57 : /*
58 : * Plugins should implement the following functions:
59 : */
60 :
61 : /**
62 : * cifs_idmap_init_plugin - Initialize the plugin interface
63 : * @handle - return pointer for an opaque handle
64 : * @errmsg - pointer to error message pointer
65 : *
66 : * This function should do whatever is required to establish a context
67 : * for later ID mapping operations. The "handle" is an opaque context
68 : * cookie that will be passed in on subsequent ID mapping operations.
69 : * The errmsg is used to pass back an error string both during the init
70 : * and in subsequent idmapping functions. On any error, the plugin
71 : * should point *errmsg at a string describing that error. Returns 0
72 : * on success and non-zero on error.
73 : */
74 0 : extern int cifs_idmap_init_plugin(void **handle, const char **errmsg);
75 :
76 : /**
77 : * cifs_idmap_exit_plugin - Destroy an idmapping context
78 : * @handle - context handle that should be destroyed
79 : *
80 : * When programs are finished with the idmapping plugin, they'll call
81 : * this function to destroy any context that was created during the
82 : * init_plugin. The handle passed back in was the one given by the init
83 : * routine.
84 : */
85 0 : extern void cifs_idmap_exit_plugin(void *handle);
86 :
87 : /**
88 : * cifs_idmap_sid_to_str - convert cifs_sid to a string
89 : * @handle - context handle
90 : * @sid - pointer to a cifs_sid
91 : * @name - return pointer for the name
92 : *
93 : * This function should convert the given cifs_sid to a string
94 : * representation or mapped name in a heap-allocated buffer. The caller
95 : * of this function is expected to free "name" on success. Returns 0 on
96 : * success and non-zero on error. On error, the errmsg pointer passed
97 : * in to the init_plugin function should point to an error string. The
98 : * caller will not free the error string.
99 : */
100 0 : extern int cifs_idmap_sid_to_str(void *handle, const struct cifs_sid *sid,
101 : char **name);
102 :
103 : /**
104 : * cifs_idmap_str_to_sid - convert string to struct cifs_sid
105 : * @handle - context handle
106 : * @name - pointer to name string to be converted
107 : * @sid - pointer to struct cifs_sid where result should go
108 : *
109 : * This function converts a name string or string representation of
110 : * a SID to a struct cifs_sid. The cifs_sid should already be
111 : * allocated. Returns 0 on success and non-zero on error. On error, the
112 : * plugin should reset the errmsg pointer passed to the init_plugin
113 : * function to an error string. The caller will not free the error string.
114 : */
115 0 : extern int cifs_idmap_str_to_sid(void *handle, const char *name,
116 : struct cifs_sid *sid);
117 :
118 : /**
119 : * cifs_idmap_sids_to_ids - convert struct cifs_sids to struct cifs_uxids
120 : * @handle - context handle
121 : * @sid - pointer to array of struct cifs_sids to be converted
122 : * @num - number of sids to be converted
123 : * @cuxid - pointer to preallocated array of struct cifs_uxids for return
124 : *
125 : * This function should map an array of struct cifs_sids to an array of
126 : * struct cifs_uxids.
127 : *
128 : * Returns 0 if at least one conversion was successful and non-zero on error.
129 : * Any that were not successfully converted will have a cuxid->type of
130 : * CIFS_UXID_TYPE_UNKNOWN.
131 : *
132 : * On any error, the plugin should reset the errmsg pointer passed to the
133 : * init_plugin function to an error string. The caller will not free the error
134 : * string.
135 : */
136 0 : extern int cifs_idmap_sids_to_ids(void *handle, const struct cifs_sid *sid,
137 : const size_t num, struct cifs_uxid *cuxid);
138 :
139 : /**
140 : * cifs_idmap_ids_to_sids - convert uid to struct cifs_sid
141 : * @handle - context handle
142 : * @cuxid - pointer to array of struct cifs_uxid to be converted to SIDs
143 : * @num - number of cifs_uxids to be converted to SIDs
144 : * @sid - pointer to preallocated array of struct cifs_sid where results
145 : * should be stored
146 : *
147 : * This function should map an array of cifs_uxids an array of struct cifs_sids.
148 : * Returns 0 if at least one conversion was successful and non-zero on error.
149 : * Any sids that were not successfully converted should have their revision
150 : * number set to 0.
151 : *
152 : * On any error, the plugin should reset the errmsg pointer passed to the
153 : * init_plugin function to an error string. The caller will not free the error
154 : * string.
155 : */
156 0 : extern int cifs_idmap_ids_to_sids(void *handle, const struct cifs_uxid *cuxid,
157 : const size_t num, struct cifs_sid *sid);
158 : #endif /* _CIFSIDMAP_H */
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