1 /*
2 Unix SMB/CIFS implementation.
3
4 file_id structure handling
5
6 Copyright (C) Andrew Tridgell 2007
7
8 This program is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3 of the License, or
11 (at your option) any later version.
12
13 This program is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with this program. If not, see <http://www.gnu.org/licenses/>.
20 */
21
22 #include "includes.h"
23 #include "lib/file_id.h"
24
25 /*
26 return True if two file_id structures are equal
27 */
file_id_equal(const struct file_id * id1,const struct file_id * id2)28 bool file_id_equal(const struct file_id *id1, const struct file_id *id2)
29 {
30 return id1->inode == id2->inode && id1->devid == id2->devid &&
31 id1->extid == id2->extid;
32 }
33
file_id_str_buf(struct file_id fid,struct file_id_buf * dst)34 char *file_id_str_buf(struct file_id fid, struct file_id_buf *dst)
35 {
36 snprintf(dst->buf,
37 sizeof(dst->buf),
38 "%"PRIu64":%"PRIu64":%"PRIu64,
39 fid.devid,
40 fid.inode,
41 fid.extid);
42 return dst->buf;
43 }
44
45 /*
46 push a 16 byte version of a file id into a buffer. This ignores the extid
47 and is needed when dev/inodes are stored in persistent storage (tdbs).
48 */
push_file_id_16(char * buf,const struct file_id * id)49 void push_file_id_16(char *buf, const struct file_id *id)
50 {
51 SIVAL(buf, 0, id->devid&0xFFFFFFFF);
52 SIVAL(buf, 4, id->devid>>32);
53 SIVAL(buf, 8, id->inode&0xFFFFFFFF);
54 SIVAL(buf, 12, id->inode>>32);
55 }
56
57 /*
58 push a 24 byte version of a file id into a buffer
59 */
push_file_id_24(char * buf,const struct file_id * id)60 void push_file_id_24(char *buf, const struct file_id *id)
61 {
62 SIVAL(buf, 0, id->devid&0xFFFFFFFF);
63 SIVAL(buf, 4, id->devid>>32);
64 SIVAL(buf, 8, id->inode&0xFFFFFFFF);
65 SIVAL(buf, 12, id->inode>>32);
66 SIVAL(buf, 16, id->extid&0xFFFFFFFF);
67 SIVAL(buf, 20, id->extid>>32);
68 }
69
70 /*
71 pull a 24 byte version of a file id from a buffer
72 */
pull_file_id_24(const char * buf,struct file_id * id)73 void pull_file_id_24(const char *buf, struct file_id *id)
74 {
75 ZERO_STRUCTP(id);
76 id->devid = IVAL(buf, 0);
77 id->devid |= ((uint64_t)IVAL(buf,4))<<32;
78 id->inode = IVAL(buf, 8);
79 id->inode |= ((uint64_t)IVAL(buf,12))<<32;
80 id->extid = IVAL(buf, 16);
81 id->extid |= ((uint64_t)IVAL(buf,20))<<32;
82 }
83
make_file_id_from_itime(SMB_STRUCT_STAT * st)84 uint64_t make_file_id_from_itime(SMB_STRUCT_STAT *st)
85 {
86 struct timespec itime = st->st_ex_itime;
87 ino_t ino = st->st_ex_ino;
88 uint64_t file_id_low;
89 uint64_t file_id;
90
91 if (st->st_ex_iflags & ST_EX_IFLAG_CALCULATED_ITIME) {
92 return ino;
93 }
94
95 round_timespec_to_nttime(&itime);
96
97 file_id_low = itime.tv_nsec;
98 if (file_id_low == 0) {
99 /*
100 * This could be by coincidence, but more likely the filesystem
101 * is only giving us seconds granularity. We need more fine
102 * grained granularity for the File-ID, so combine with the
103 * inode number.
104 */
105 file_id_low = ino & ((1 << 30) - 1);
106 }
107
108 /*
109 * Set the high bit so ideally File-IDs based on inode numbers and
110 * File-IDs based on Birth Time use disjoint ranges, given inodes never
111 * have the high bit set.
112 */
113 file_id = ((uint64_t)1) << 63;
114 file_id |= (uint64_t)itime.tv_sec << 30;
115 file_id |= file_id_low;
116
117 return file_id;
118 }
119