1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
|
/* Server address list management
*
* Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public Licence
* as published by the Free Software Foundation; either version
* 2 of the Licence, or (at your option) any later version.
*/
#include <linux/slab.h>
#include <linux/ctype.h>
#include <linux/dns_resolver.h>
#include <linux/inet.h>
#include <keys/rxrpc-type.h>
#include "internal.h"
#include "afs_fs.h"
//#define AFS_MAX_ADDRESSES
// ((unsigned int)((PAGE_SIZE - sizeof(struct afs_addr_list)) /
// sizeof(struct sockaddr_rxrpc)))
#define AFS_MAX_ADDRESSES ((unsigned int)(sizeof(unsigned long) * 8))
/*
* Release an address list.
*/
void afs_put_addrlist(struct afs_addr_list *alist)
{
if (alist && refcount_dec_and_test(&alist->usage))
call_rcu(&alist->rcu, (rcu_callback_t)kfree);
}
/*
* Allocate an address list.
*/
struct afs_addr_list *afs_alloc_addrlist(unsigned int nr,
unsigned short service,
unsigned short port)
{
struct afs_addr_list *alist;
unsigned int i;
_enter("%u,%u,%u", nr, service, port);
alist = kzalloc(sizeof(*alist) + sizeof(alist->addrs[0]) * nr,
GFP_KERNEL);
if (!alist)
return NULL;
refcount_set(&alist->usage, 1);
for (i = 0; i < nr; i++) {
struct sockaddr_rxrpc *srx = &alist->addrs[i];
srx->srx_family = AF_RXRPC;
srx->srx_service = service;
srx->transport_type = SOCK_DGRAM;
srx->transport_len = sizeof(srx->transport.sin6);
srx->transport.sin6.sin6_family = AF_INET6;
srx->transport.sin6.sin6_port = htons(port);
}
return alist;
}
/*
* Parse a text string consisting of delimited addresses.
*/
struct afs_addr_list *afs_parse_text_addrs(const char *text, size_t len,
char delim,
unsigned short service,
unsigned short port)
{
struct afs_addr_list *alist;
const char *p, *end = text + len;
unsigned int nr = 0;
_enter("%*.*s,%c", (int)len, (int)len, text, delim);
if (!len)
return ERR_PTR(-EDESTADDRREQ);
if (delim == ':' && (memchr(text, ',', len) || !memchr(text, '.', len)))
delim = ',';
/* Count the addresses */
p = text;
do {
if (!*p)
return ERR_PTR(-EINVAL);
if (*p == delim)
continue;
nr++;
if (*p == '[') {
p++;
if (p == end)
return ERR_PTR(-EINVAL);
p = memchr(p, ']', end - p);
if (!p)
return ERR_PTR(-EINVAL);
p++;
if (p >= end)
break;
}
p = memchr(p, delim, end - p);
if (!p)
break;
p++;
} while (p < end);
_debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);
if (nr > AFS_MAX_ADDRESSES)
nr = AFS_MAX_ADDRESSES;
alist = afs_alloc_addrlist(nr, service, port);
if (!alist)
return ERR_PTR(-ENOMEM);
/* Extract the addresses */
p = text;
do {
struct sockaddr_rxrpc *srx = &alist->addrs[alist->nr_addrs];
char tdelim = delim;
if (*p == delim) {
p++;
continue;
}
if (*p == '[') {
p++;
tdelim = ']';
}
if (in4_pton(p, end - p,
(u8 *)&srx->transport.sin6.sin6_addr.s6_addr32[3],
tdelim, &p)) {
srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
} else if (in6_pton(p, end - p,
srx->transport.sin6.sin6_addr.s6_addr,
tdelim, &p)) {
/* Nothing to do */
} else {
goto bad_address;
}
if (tdelim == ']') {
if (p == end || *p != ']')
goto bad_address;
p++;
}
if (p < end) {
if (*p == '+') {
/* Port number specification "+1234" */
unsigned int xport = 0;
p++;
if (p >= end || !isdigit(*p))
goto bad_address;
do {
xport *= 10;
xport += *p - '0';
if (xport > 65535)
goto bad_address;
p++;
} while (p < end && isdigit(*p));
srx->transport.sin6.sin6_port = htons(xport);
} else if (*p == delim) {
p++;
} else {
goto bad_address;
}
}
alist->nr_addrs++;
} while (p < end && alist->nr_addrs < AFS_MAX_ADDRESSES);
_leave(" = [nr %u]", alist->nr_addrs);
return alist;
bad_address:
kfree(alist);
return ERR_PTR(-EINVAL);
}
/*
* Compare old and new address lists to see if there's been any change.
* - How to do this in better than O(Nlog(N)) time?
* - We don't really want to sort the address list, but would rather take the
* list as we got it so as not to undo record rotation by the DNS server.
*/
#if 0
static int afs_cmp_addr_list(const struct afs_addr_list *a1,
const struct afs_addr_list *a2)
{
}
#endif
/*
* Perform a DNS query for VL servers and build a up an address list.
*/
struct afs_addr_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
{
struct afs_addr_list *alist;
char *vllist = NULL;
int ret;
_enter("%s", cell->name);
ret = dns_query("afsdb", cell->name, cell->name_len,
"ipv4", &vllist, _expiry);
if (ret < 0)
return ERR_PTR(ret);
alist = afs_parse_text_addrs(vllist, strlen(vllist), ',',
VL_SERVICE, AFS_VL_PORT);
if (IS_ERR(alist)) {
kfree(vllist);
if (alist != ERR_PTR(-ENOMEM))
pr_err("Failed to parse DNS data\n");
return alist;
}
kfree(vllist);
return alist;
}
/*
* Merge an IPv4 entry into a fileserver address list.
*/
void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
{
struct sockaddr_in6 *a;
__be16 xport = htons(port);
int i;
for (i = 0; i < alist->nr_ipv4; i++) {
a = &alist->addrs[i].transport.sin6;
if (xdr == a->sin6_addr.s6_addr32[3] &&
xport == a->sin6_port)
return;
if (xdr == a->sin6_addr.s6_addr32[3] &&
xport < a->sin6_port)
break;
if (xdr < a->sin6_addr.s6_addr32[3])
break;
}
if (i < alist->nr_addrs)
memmove(alist->addrs + i + 1,
alist->addrs + i,
|