hc
2024-12-19 9370bb92b2d16684ee45cf24e879c93c509162da
kernel/fs/afs/addr_list.c
....@@ -1,12 +1,8 @@
1
+// SPDX-License-Identifier: GPL-2.0-or-later
12 /* Server address list management
23 *
34 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
45 * Written by David Howells (dhowells@redhat.com)
5
- *
6
- * This program is free software; you can redistribute it and/or
7
- * modify it under the terms of the GNU General Public Licence
8
- * as published by the Free Software Foundation; either version
9
- * 2 of the Licence, or (at your option) any later version.
106 */
117
128 #include <linux/slab.h>
....@@ -17,18 +13,13 @@
1713 #include "internal.h"
1814 #include "afs_fs.h"
1915
20
-//#define AFS_MAX_ADDRESSES
21
-// ((unsigned int)((PAGE_SIZE - sizeof(struct afs_addr_list)) /
22
-// sizeof(struct sockaddr_rxrpc)))
23
-#define AFS_MAX_ADDRESSES ((unsigned int)(sizeof(unsigned long) * 8))
24
-
2516 /*
2617 * Release an address list.
2718 */
2819 void afs_put_addrlist(struct afs_addr_list *alist)
2920 {
3021 if (alist && refcount_dec_and_test(&alist->usage))
31
- call_rcu(&alist->rcu, (rcu_callback_t)kfree);
22
+ kfree_rcu(alist, rcu);
3223 }
3324
3425 /*
....@@ -43,11 +34,15 @@
4334
4435 _enter("%u,%u,%u", nr, service, port);
4536
37
+ if (nr > AFS_MAX_ADDRESSES)
38
+ nr = AFS_MAX_ADDRESSES;
39
+
4640 alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);
4741 if (!alist)
4842 return NULL;
4943
5044 refcount_set(&alist->usage, 1);
45
+ alist->max_addrs = nr;
5146
5247 for (i = 0; i < nr; i++) {
5348 struct sockaddr_rxrpc *srx = &alist->addrs[i];
....@@ -65,19 +60,25 @@
6560 /*
6661 * Parse a text string consisting of delimited addresses.
6762 */
68
-struct afs_addr_list *afs_parse_text_addrs(const char *text, size_t len,
69
- char delim,
70
- unsigned short service,
71
- unsigned short port)
63
+struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *net,
64
+ const char *text, size_t len,
65
+ char delim,
66
+ unsigned short service,
67
+ unsigned short port)
7268 {
69
+ struct afs_vlserver_list *vllist;
7370 struct afs_addr_list *alist;
7471 const char *p, *end = text + len;
72
+ const char *problem;
7573 unsigned int nr = 0;
74
+ int ret = -ENOMEM;
7675
7776 _enter("%*.*s,%c", (int)len, (int)len, text, delim);
7877
79
- if (!len)
78
+ if (!len) {
79
+ _leave(" = -EDESTADDRREQ [empty]");
8080 return ERR_PTR(-EDESTADDRREQ);
81
+ }
8182
8283 if (delim == ':' && (memchr(text, ',', len) || !memchr(text, '.', len)))
8384 delim = ',';
....@@ -85,18 +86,24 @@
8586 /* Count the addresses */
8687 p = text;
8788 do {
88
- if (!*p)
89
- return ERR_PTR(-EINVAL);
89
+ if (!*p) {
90
+ problem = "nul";
91
+ goto inval;
92
+ }
9093 if (*p == delim)
9194 continue;
9295 nr++;
9396 if (*p == '[') {
9497 p++;
95
- if (p == end)
96
- return ERR_PTR(-EINVAL);
98
+ if (p == end) {
99
+ problem = "brace1";
100
+ goto inval;
101
+ }
97102 p = memchr(p, ']', end - p);
98
- if (!p)
99
- return ERR_PTR(-EINVAL);
103
+ if (!p) {
104
+ problem = "brace2";
105
+ goto inval;
106
+ }
100107 p++;
101108 if (p >= end)
102109 break;
....@@ -109,18 +116,27 @@
109116 } while (p < end);
110117
111118 _debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);
112
- if (nr > AFS_MAX_ADDRESSES)
113
- nr = AFS_MAX_ADDRESSES;
114119
115
- alist = afs_alloc_addrlist(nr, service, port);
116
- if (!alist)
120
+ vllist = afs_alloc_vlserver_list(1);
121
+ if (!vllist)
117122 return ERR_PTR(-ENOMEM);
123
+
124
+ vllist->nr_servers = 1;
125
+ vllist->servers[0].server = afs_alloc_vlserver("<dummy>", 7, AFS_VL_PORT);
126
+ if (!vllist->servers[0].server)
127
+ goto error_vl;
128
+
129
+ alist = afs_alloc_addrlist(nr, service, AFS_VL_PORT);
130
+ if (!alist)
131
+ goto error;
118132
119133 /* Extract the addresses */
120134 p = text;
121135 do {
122
- struct sockaddr_rxrpc *srx = &alist->addrs[alist->nr_addrs];
123136 const char *q, *stop;
137
+ unsigned int xport = port;
138
+ __be32 x[4];
139
+ int family;
124140
125141 if (*p == delim) {
126142 p++;
....@@ -136,58 +152,74 @@
136152 break;
137153 }
138154
139
- if (in4_pton(p, q - p,
140
- (u8 *)&srx->transport.sin6.sin6_addr.s6_addr32[3],
141
- -1, &stop)) {
142
- srx->transport.sin6.sin6_addr.s6_addr32[0] = 0;
143
- srx->transport.sin6.sin6_addr.s6_addr32[1] = 0;
144
- srx->transport.sin6.sin6_addr.s6_addr32[2] = htonl(0xffff);
145
- } else if (in6_pton(p, q - p,
146
- srx->transport.sin6.sin6_addr.s6_addr,
147
- -1, &stop)) {
148
- /* Nothing to do */
155
+ if (in4_pton(p, q - p, (u8 *)&x[0], -1, &stop)) {
156
+ family = AF_INET;
157
+ } else if (in6_pton(p, q - p, (u8 *)x, -1, &stop)) {
158
+ family = AF_INET6;
149159 } else {
160
+ problem = "family";
150161 goto bad_address;
151162 }
152163
153
- if (stop != q)
154
- goto bad_address;
155
-
156164 p = q;
165
+ if (stop != p) {
166
+ problem = "nostop";
167
+ goto bad_address;
168
+ }
169
+
157170 if (q < end && *q == ']')
158171 p++;
159172
160173 if (p < end) {
161174 if (*p == '+') {
162175 /* Port number specification "+1234" */
163
- unsigned int xport = 0;
176
+ xport = 0;
164177 p++;
165
- if (p >= end || !isdigit(*p))
178
+ if (p >= end || !isdigit(*p)) {
179
+ problem = "port";
166180 goto bad_address;
181
+ }
167182 do {
168183 xport *= 10;
169184 xport += *p - '0';
170
- if (xport > 65535)
185
+ if (xport > 65535) {
186
+ problem = "pval";
171187 goto bad_address;
188
+ }
172189 p++;
173190 } while (p < end && isdigit(*p));
174
- srx->transport.sin6.sin6_port = htons(xport);
175191 } else if (*p == delim) {
176192 p++;
177193 } else {
194
+ problem = "weird";
178195 goto bad_address;
179196 }
180197 }
181198
182
- alist->nr_addrs++;
183
- } while (p < end && alist->nr_addrs < AFS_MAX_ADDRESSES);
199
+ if (family == AF_INET)
200
+ afs_merge_fs_addr4(alist, x[0], xport);
201
+ else
202
+ afs_merge_fs_addr6(alist, x, xport);
184203
204
+ } while (p < end);
205
+
206
+ rcu_assign_pointer(vllist->servers[0].server->addresses, alist);
185207 _leave(" = [nr %u]", alist->nr_addrs);
186
- return alist;
208
+ return vllist;
187209
188
-bad_address:
189
- kfree(alist);
210
+inval:
211
+ _leave(" = -EINVAL [%s %zu %*.*s]",
212
+ problem, p - text, (int)len, (int)len, text);
190213 return ERR_PTR(-EINVAL);
214
+bad_address:
215
+ _leave(" = -EINVAL [%s %zu %*.*s]",
216
+ problem, p - text, (int)len, (int)len, text);
217
+ ret = -EINVAL;
218
+error:
219
+ afs_put_addrlist(alist);
220
+error_vl:
221
+ afs_put_vlserverlist(net, vllist);
222
+ return ERR_PTR(ret);
191223 }
192224
193225 /*
....@@ -206,30 +238,34 @@
206238 /*
207239 * Perform a DNS query for VL servers and build a up an address list.
208240 */
209
-struct afs_addr_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
241
+struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
210242 {
211
- struct afs_addr_list *alist;
212
- char *vllist = NULL;
243
+ struct afs_vlserver_list *vllist;
244
+ char *result = NULL;
213245 int ret;
214246
215247 _enter("%s", cell->name);
216248
217
- ret = dns_query("afsdb", cell->name, cell->name_len,
218
- "", &vllist, _expiry);
219
- if (ret < 0)
249
+ ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,
250
+ "srv=1", &result, _expiry, true);
251
+ if (ret < 0) {
252
+ _leave(" = %d [dns]", ret);
220253 return ERR_PTR(ret);
221
-
222
- alist = afs_parse_text_addrs(vllist, strlen(vllist), ',',
223
- VL_SERVICE, AFS_VL_PORT);
224
- if (IS_ERR(alist)) {
225
- kfree(vllist);
226
- if (alist != ERR_PTR(-ENOMEM))
227
- pr_err("Failed to parse DNS data\n");
228
- return alist;
229254 }
230255
231
- kfree(vllist);
232
- return alist;
256
+ if (*_expiry == 0)
257
+ *_expiry = ktime_get_real_seconds() + 60;
258
+
259
+ if (ret > 1 && result[0] == 0)
260
+ vllist = afs_extract_vlserver_list(cell, result, ret);
261
+ else
262
+ vllist = afs_parse_text_addrs(cell->net, result, ret, ',',
263
+ VL_SERVICE, AFS_VL_PORT);
264
+ kfree(result);
265
+ if (IS_ERR(vllist) && vllist != ERR_PTR(-ENOMEM))
266
+ pr_err("Failed to parse DNS data %ld\n", PTR_ERR(vllist));
267
+
268
+ return vllist;
233269 }
234270
235271 /*
....@@ -237,19 +273,23 @@
237273 */
238274 void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
239275 {
240
- struct sockaddr_in6 *a;
241
- __be16 xport = htons(port);
276
+ struct sockaddr_rxrpc *srx;
277
+ u32 addr = ntohl(xdr);
242278 int i;
243279
280
+ if (alist->nr_addrs >= alist->max_addrs)
281
+ return;
282
+
244283 for (i = 0; i < alist->nr_ipv4; i++) {
245
- a = &alist->addrs[i].transport.sin6;
246
- if (xdr == a->sin6_addr.s6_addr32[3] &&
247
- xport == a->sin6_port)
284
+ struct sockaddr_in *a = &alist->addrs[i].transport.sin;
285
+ u32 a_addr = ntohl(a->sin_addr.s_addr);
286
+ u16 a_port = ntohs(a->sin_port);
287
+
288
+ if (addr == a_addr && port == a_port)
248289 return;
249
- if (xdr == a->sin6_addr.s6_addr32[3] &&
250
- (u16 __force)xport < (u16 __force)a->sin6_port)
290
+ if (addr == a_addr && port < a_port)
251291 break;
252
- if ((u32 __force)xdr < (u32 __force)a->sin6_addr.s6_addr32[3])
292
+ if (addr < a_addr)
253293 break;
254294 }
255295
....@@ -258,12 +298,13 @@
258298 alist->addrs + i,
259299 sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
260300
261
- a = &alist->addrs[i].transport.sin6;
262
- a->sin6_port = xport;
263
- a->sin6_addr.s6_addr32[0] = 0;
264
- a->sin6_addr.s6_addr32[1] = 0;
265
- a->sin6_addr.s6_addr32[2] = htonl(0xffff);
266
- a->sin6_addr.s6_addr32[3] = xdr;
301
+ srx = &alist->addrs[i];
302
+ srx->srx_family = AF_RXRPC;
303
+ srx->transport_type = SOCK_DGRAM;
304
+ srx->transport_len = sizeof(srx->transport.sin);
305
+ srx->transport.sin.sin_family = AF_INET;
306
+ srx->transport.sin.sin_port = htons(port);
307
+ srx->transport.sin.sin_addr.s_addr = xdr;
267308 alist->nr_ipv4++;
268309 alist->nr_addrs++;
269310 }
....@@ -273,18 +314,20 @@
273314 */
274315 void afs_merge_fs_addr6(struct afs_addr_list *alist, __be32 *xdr, u16 port)
275316 {
276
- struct sockaddr_in6 *a;
277
- __be16 xport = htons(port);
317
+ struct sockaddr_rxrpc *srx;
278318 int i, diff;
279319
320
+ if (alist->nr_addrs >= alist->max_addrs)
321
+ return;
322
+
280323 for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
281
- a = &alist->addrs[i].transport.sin6;
324
+ struct sockaddr_in6 *a = &alist->addrs[i].transport.sin6;
325
+ u16 a_port = ntohs(a->sin6_port);
326
+
282327 diff = memcmp(xdr, &a->sin6_addr, 16);
283
- if (diff == 0 &&
284
- xport == a->sin6_port)
328
+ if (diff == 0 && port == a_port)
285329 return;
286
- if (diff == 0 &&
287
- (u16 __force)xport < (u16 __force)a->sin6_port)
330
+ if (diff == 0 && port < a_port)
288331 break;
289332 if (diff < 0)
290333 break;
....@@ -295,12 +338,13 @@
295338 alist->addrs + i,
296339 sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
297340
298
- a = &alist->addrs[i].transport.sin6;
299
- a->sin6_port = xport;
300
- a->sin6_addr.s6_addr32[0] = xdr[0];
301
- a->sin6_addr.s6_addr32[1] = xdr[1];
302
- a->sin6_addr.s6_addr32[2] = xdr[2];
303
- a->sin6_addr.s6_addr32[3] = xdr[3];
341
+ srx = &alist->addrs[i];
342
+ srx->srx_family = AF_RXRPC;
343
+ srx->transport_type = SOCK_DGRAM;
344
+ srx->transport_len = sizeof(srx->transport.sin6);
345
+ srx->transport.sin6.sin6_family = AF_INET6;
346
+ srx->transport.sin6.sin6_port = htons(port);
347
+ memcpy(&srx->transport.sin6.sin6_addr, xdr, 16);
304348 alist->nr_addrs++;
305349 }
306350
....@@ -309,25 +353,33 @@
309353 */
310354 bool afs_iterate_addresses(struct afs_addr_cursor *ac)
311355 {
312
- _enter("%hu+%hd", ac->start, (short)ac->index);
356
+ unsigned long set, failed;
357
+ int index;
313358
314359 if (!ac->alist)
315360 return false;
316361
317
- if (ac->begun) {
318
- ac->index++;
319
- if (ac->index == ac->alist->nr_addrs)
320
- ac->index = 0;
362
+ set = ac->alist->responded;
363
+ failed = ac->alist->failed;
364
+ _enter("%lx-%lx-%lx,%d", set, failed, ac->tried, ac->index);
321365
322
- if (ac->index == ac->start) {
323
- ac->error = -EDESTADDRREQ;
324
- return false;
325
- }
326
- }
366
+ ac->nr_iterations++;
327367
328
- ac->begun = true;
368
+ set &= ~(failed | ac->tried);
369
+
370
+ if (!set)
371
+ return false;
372
+
373
+ index = READ_ONCE(ac->alist->preferred);
374
+ if (test_bit(index, &set))
375
+ goto selected;
376
+
377
+ index = __ffs(set);
378
+
379
+selected:
380
+ ac->index = index;
381
+ set_bit(index, &ac->tried);
329382 ac->responded = false;
330
- ac->addr = &ac->alist->addrs[ac->index];
331383 return true;
332384 }
333385
....@@ -340,53 +392,13 @@
340392
341393 alist = ac->alist;
342394 if (alist) {
343
- if (ac->responded && ac->index != ac->start)
344
- WRITE_ONCE(alist->index, ac->index);
395
+ if (ac->responded &&
396
+ ac->index != alist->preferred &&
397
+ test_bit(ac->alist->preferred, &ac->tried))
398
+ WRITE_ONCE(alist->preferred, ac->index);
345399 afs_put_addrlist(alist);
400
+ ac->alist = NULL;
346401 }
347402
348
- ac->addr = NULL;
349
- ac->alist = NULL;
350
- ac->begun = false;
351403 return ac->error;
352
-}
353
-
354
-/*
355
- * Set the address cursor for iterating over VL servers.
356
- */
357
-int afs_set_vl_cursor(struct afs_addr_cursor *ac, struct afs_cell *cell)
358
-{
359
- struct afs_addr_list *alist;
360
- int ret;
361
-
362
- if (!rcu_access_pointer(cell->vl_addrs)) {
363
- ret = wait_on_bit(&cell->flags, AFS_CELL_FL_NO_LOOKUP_YET,
364
- TASK_INTERRUPTIBLE);
365
- if (ret < 0)
366
- return ret;
367
-
368
- if (!rcu_access_pointer(cell->vl_addrs) &&
369
- ktime_get_real_seconds() < cell->dns_expiry)
370
- return cell->error;
371
- }
372
-
373
- read_lock(&cell->vl_addrs_lock);
374
- alist = rcu_dereference_protected(cell->vl_addrs,
375
- lockdep_is_held(&cell->vl_addrs_lock));
376
- if (alist->nr_addrs > 0)
377
- afs_get_addrlist(alist);
378
- else
379
- alist = NULL;
380
- read_unlock(&cell->vl_addrs_lock);
381
-
382
- if (!alist)
383
- return -EDESTADDRREQ;
384
-
385
- ac->alist = alist;
386
- ac->addr = NULL;
387
- ac->start = READ_ONCE(alist->index);
388
- ac->index = ac->start;
389
- ac->error = 0;
390
- ac->begun = false;
391
- return 0;
392404 }