1 /** @file
2 * @brief Class for handling UUIDs
3 */
4 /* Copyright (C) 2008 Lemur Consulting Ltd
5 * Copyright (C) 2013,2015,2016,2017,2018 Olly Betts
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <config.h>
23
24 #include "uuids.h"
25
26 #include "xapian/error.h"
27
28 #include <cerrno>
29 #include <cstring>
30 #include "stringutils.h"
31
32 #include <sys/types.h>
33 #include "safefcntl.h"
34 #include "safeunistd.h"
35
36 #ifdef USE_PROC_FOR_UUID
37 # include "safesysstat.h"
38 #elif defined HAVE_UUID_UUID_H
39 # include <exception>
40 # include <uuid/uuid.h>
41 #elif defined HAVE_UUID_H
42 // UUID API on FreeBSD, NetBSD, OpenBSD and AIX.
43 # include <arpa/inet.h> // For htonl() and htons().
44 # include <exception>
45 # include <uuid.h>
46 #elif defined USE_WIN32_UUID_API
47 # include "safewindows.h"
48 # include <rpc.h>
49 # ifdef __WIN32__
50 # include "safewinsock2.h" // For htonl() and htons().
51 # else
52 // Cygwin:
53 # include <arpa/inet.h> // For htonl() and htons().
54 # endif
55 #endif
56
57 using namespace std;
58
59 /// Bit-mask to determine where to put hyphens in the string representation.
60 static constexpr unsigned UUID_GAP_MASK = 0x2a8;
61
62 void
generate()63 Uuid::generate()
64 {
65 #ifdef USE_PROC_FOR_UUID
66 char buf[STRING_SIZE];
67 int fd = open("/proc/sys/kernel/random/uuid", O_RDONLY);
68 if (rare(fd == -1)) {
69 throw Xapian::DatabaseCreateError("Opening UUID generator failed", errno);
70 }
71 bool failed = (read(fd, buf, STRING_SIZE) != STRING_SIZE);
72 close(fd);
73 if (failed) {
74 throw Xapian::DatabaseCreateError("Generating UUID failed");
75 }
76 parse(buf);
77 #elif defined HAVE_UUID_UUID_H
78 uuid_t uu;
79 uuid_generate(uu);
80 memcpy(uuid_data, &uu, BINARY_SIZE);
81 #elif defined HAVE_UUID_H
82 uuid_t uu;
83 uint32_t status;
84 uuid_create(&uu, &status);
85 if (status != uuid_s_ok) {
86 // Can only be uuid_s_no_memory it seems.
87 throw std::bad_alloc();
88 }
89 uu.time_low = htonl(uu.time_low);
90 uu.time_mid = htons(uu.time_mid);
91 uu.time_hi_and_version = htons(uu.time_hi_and_version);
92 memcpy(uuid_data, &uu, BINARY_SIZE);
93 #elif defined USE_WIN32_UUID_API
94 UUID uuid;
95 if (rare(UuidCreate(&uuid) != RPC_S_OK)) {
96 // Throw a DatabaseCreateError, since we can't make a UUID. The
97 // windows API documentation is a bit unclear about the situations in
98 // which this can happen.
99 throw Xapian::DatabaseCreateError("Cannot create UUID");
100 }
101 uuid.Data1 = htonl(uuid.Data1);
102 uuid.Data2 = htons(uuid.Data2);
103 uuid.Data3 = htons(uuid.Data3);
104 memcpy(uuid_data, &uuid, BINARY_SIZE);
105 #else
106 # error Do not know how to generate UUIDs
107 #endif
108 }
109
110 void
parse(const char * in)111 Uuid::parse(const char* in)
112 {
113 for (unsigned i = 0; i != BINARY_SIZE; ++i) {
114 uuid_data[i] = hex_digit(in[0]) << 4 | hex_digit(in[1]);
115 in += ((UUID_GAP_MASK >> i) & 1) | 2;
116 }
117 }
118
119 string
to_string() const120 Uuid::to_string() const
121 {
122 string result;
123 result.reserve(STRING_SIZE);
124 for (unsigned i = 0; i != BINARY_SIZE; ++i) {
125 unsigned char ch = uuid_data[i];
126 result += "0123456789abcdef"[ch >> 4];
127 result += "0123456789abcdef"[ch & 0x0f];
128 if ((UUID_GAP_MASK >> i) & 1)
129 result += '-';
130 }
131 return result;
132 }
133