Loading...
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Server address list management
3 *
4 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/slab.h>
9#include <linux/ctype.h>
10#include <linux/dns_resolver.h>
11#include <linux/inet.h>
12#include <keys/rxrpc-type.h>
13#include "internal.h"
14#include "afs_fs.h"
15
16static void afs_free_addrlist(struct rcu_head *rcu)
17{
18 struct afs_addr_list *alist = container_of(rcu, struct afs_addr_list, rcu);
19 unsigned int i;
20
21 for (i = 0; i < alist->nr_addrs; i++)
22 rxrpc_kernel_put_peer(alist->addrs[i].peer);
23 trace_afs_alist(alist->debug_id, refcount_read(&alist->usage), afs_alist_trace_free);
24 kfree(alist);
25}
26
27/*
28 * Release an address list.
29 */
30void afs_put_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
31{
32 unsigned int debug_id;
33 bool dead;
34 int r;
35
36 if (!alist)
37 return;
38 debug_id = alist->debug_id;
39 dead = __refcount_dec_and_test(&alist->usage, &r);
40 trace_afs_alist(debug_id, r - 1, reason);
41 if (dead)
42 call_rcu(&alist->rcu, afs_free_addrlist);
43}
44
45struct afs_addr_list *afs_get_addrlist(struct afs_addr_list *alist, enum afs_alist_trace reason)
46{
47 int r;
48
49 if (alist) {
50 __refcount_inc(&alist->usage, &r);
51 trace_afs_alist(alist->debug_id, r + 1, reason);
52 }
53 return alist;
54}
55
56/*
57 * Allocate an address list.
58 */
59struct afs_addr_list *afs_alloc_addrlist(unsigned int nr)
60{
61 struct afs_addr_list *alist;
62 static atomic_t debug_id;
63
64 _enter("%u", nr);
65
66 if (nr > AFS_MAX_ADDRESSES)
67 nr = AFS_MAX_ADDRESSES;
68
69 alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);
70 if (!alist)
71 return NULL;
72
73 refcount_set(&alist->usage, 1);
74 alist->max_addrs = nr;
75 alist->debug_id = atomic_inc_return(&debug_id);
76 trace_afs_alist(alist->debug_id, 1, afs_alist_trace_alloc);
77 return alist;
78}
79
80/*
81 * Parse a text string consisting of delimited addresses.
82 */
83struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *net,
84 const char *text, size_t len,
85 char delim,
86 unsigned short service,
87 unsigned short port)
88{
89 struct afs_vlserver_list *vllist;
90 struct afs_addr_list *alist;
91 const char *p, *end = text + len;
92 const char *problem;
93 unsigned int nr = 0;
94 int ret = -ENOMEM;
95
96 _enter("%*.*s,%c", (int)len, (int)len, text, delim);
97
98 if (!len) {
99 _leave(" = -EDESTADDRREQ [empty]");
100 return ERR_PTR(-EDESTADDRREQ);
101 }
102
103 if (delim == ':' && (memchr(text, ',', len) || !memchr(text, '.', len)))
104 delim = ',';
105
106 /* Count the addresses */
107 p = text;
108 do {
109 if (!*p) {
110 problem = "nul";
111 goto inval;
112 }
113 if (*p == delim)
114 continue;
115 nr++;
116 if (*p == '[') {
117 p++;
118 if (p == end) {
119 problem = "brace1";
120 goto inval;
121 }
122 p = memchr(p, ']', end - p);
123 if (!p) {
124 problem = "brace2";
125 goto inval;
126 }
127 p++;
128 if (p >= end)
129 break;
130 }
131
132 p = memchr(p, delim, end - p);
133 if (!p)
134 break;
135 p++;
136 } while (p < end);
137
138 _debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);
139
140 vllist = afs_alloc_vlserver_list(1);
141 if (!vllist)
142 return ERR_PTR(-ENOMEM);
143
144 vllist->nr_servers = 1;
145 vllist->servers[0].server = afs_alloc_vlserver("<dummy>", 7, AFS_VL_PORT);
146 if (!vllist->servers[0].server)
147 goto error_vl;
148
149 alist = afs_alloc_addrlist(nr);
150 if (!alist)
151 goto error;
152
153 /* Extract the addresses */
154 p = text;
155 do {
156 const char *q, *stop;
157 unsigned int xport = port;
158 __be32 x[4];
159 int family;
160
161 if (*p == delim) {
162 p++;
163 continue;
164 }
165
166 if (*p == '[') {
167 p++;
168 q = memchr(p, ']', end - p);
169 } else {
170 for (q = p; q < end; q++)
171 if (*q == '+' || *q == delim)
172 break;
173 }
174
175 if (in4_pton(p, q - p, (u8 *)&x[0], -1, &stop)) {
176 family = AF_INET;
177 } else if (in6_pton(p, q - p, (u8 *)x, -1, &stop)) {
178 family = AF_INET6;
179 } else {
180 problem = "family";
181 goto bad_address;
182 }
183
184 p = q;
185 if (stop != p) {
186 problem = "nostop";
187 goto bad_address;
188 }
189
190 if (q < end && *q == ']')
191 p++;
192
193 if (p < end) {
194 if (*p == '+') {
195 /* Port number specification "+1234" */
196 xport = 0;
197 p++;
198 if (p >= end || !isdigit(*p)) {
199 problem = "port";
200 goto bad_address;
201 }
202 do {
203 xport *= 10;
204 xport += *p - '0';
205 if (xport > 65535) {
206 problem = "pval";
207 goto bad_address;
208 }
209 p++;
210 } while (p < end && isdigit(*p));
211 } else if (*p == delim) {
212 p++;
213 } else {
214 problem = "weird";
215 goto bad_address;
216 }
217 }
218
219 if (family == AF_INET)
220 ret = afs_merge_fs_addr4(net, alist, x[0], xport);
221 else
222 ret = afs_merge_fs_addr6(net, alist, x, xport);
223 if (ret < 0)
224 goto error;
225
226 } while (p < end);
227
228 rcu_assign_pointer(vllist->servers[0].server->addresses, alist);
229 _leave(" = [nr %u]", alist->nr_addrs);
230 return vllist;
231
232inval:
233 _leave(" = -EINVAL [%s %zu %*.*s]",
234 problem, p - text, (int)len, (int)len, text);
235 return ERR_PTR(-EINVAL);
236bad_address:
237 _leave(" = -EINVAL [%s %zu %*.*s]",
238 problem, p - text, (int)len, (int)len, text);
239 ret = -EINVAL;
240error:
241 afs_put_addrlist(alist, afs_alist_trace_put_parse_error);
242error_vl:
243 afs_put_vlserverlist(net, vllist);
244 return ERR_PTR(ret);
245}
246
247/*
248 * Perform a DNS query for VL servers and build a up an address list.
249 */
250struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
251{
252 struct afs_vlserver_list *vllist;
253 char *result = NULL;
254 int ret;
255
256 _enter("%s", cell->name);
257
258 ret = dns_query(cell->net->net, "afsdb", cell->name, cell->name_len,
259 "srv=1", &result, _expiry, true);
260 if (ret < 0) {
261 _leave(" = %d [dns]", ret);
262 return ERR_PTR(ret);
263 }
264
265 if (*_expiry == 0)
266 *_expiry = ktime_get_real_seconds() + 60;
267
268 if (ret > 1 && result[0] == 0)
269 vllist = afs_extract_vlserver_list(cell, result, ret);
270 else
271 vllist = afs_parse_text_addrs(cell->net, result, ret, ',',
272 VL_SERVICE, AFS_VL_PORT);
273 kfree(result);
274 if (IS_ERR(vllist) && vllist != ERR_PTR(-ENOMEM))
275 pr_err("Failed to parse DNS data %ld\n", PTR_ERR(vllist));
276
277 return vllist;
278}
279
280/*
281 * Merge an IPv4 entry into a fileserver address list.
282 */
283int afs_merge_fs_addr4(struct afs_net *net, struct afs_addr_list *alist,
284 __be32 xdr, u16 port)
285{
286 struct sockaddr_rxrpc srx;
287 struct rxrpc_peer *peer;
288 int i;
289
290 if (alist->nr_addrs >= alist->max_addrs)
291 return 0;
292
293 srx.srx_family = AF_RXRPC;
294 srx.transport_type = SOCK_DGRAM;
295 srx.transport_len = sizeof(srx.transport.sin);
296 srx.transport.sin.sin_family = AF_INET;
297 srx.transport.sin.sin_port = htons(port);
298 srx.transport.sin.sin_addr.s_addr = xdr;
299
300 peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
301 if (!peer)
302 return -ENOMEM;
303
304 for (i = 0; i < alist->nr_ipv4; i++) {
305 if (peer == alist->addrs[i].peer) {
306 rxrpc_kernel_put_peer(peer);
307 return 0;
308 }
309 if (peer <= alist->addrs[i].peer)
310 break;
311 }
312
313 if (i < alist->nr_addrs)
314 memmove(alist->addrs + i + 1,
315 alist->addrs + i,
316 sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
317
318 alist->addrs[i].peer = peer;
319 alist->nr_ipv4++;
320 alist->nr_addrs++;
321 return 0;
322}
323
324/*
325 * Merge an IPv6 entry into a fileserver address list.
326 */
327int afs_merge_fs_addr6(struct afs_net *net, struct afs_addr_list *alist,
328 __be32 *xdr, u16 port)
329{
330 struct sockaddr_rxrpc srx;
331 struct rxrpc_peer *peer;
332 int i;
333
334 if (alist->nr_addrs >= alist->max_addrs)
335 return 0;
336
337 srx.srx_family = AF_RXRPC;
338 srx.transport_type = SOCK_DGRAM;
339 srx.transport_len = sizeof(srx.transport.sin6);
340 srx.transport.sin6.sin6_family = AF_INET6;
341 srx.transport.sin6.sin6_port = htons(port);
342 memcpy(&srx.transport.sin6.sin6_addr, xdr, 16);
343
344 peer = rxrpc_kernel_lookup_peer(net->socket, &srx, GFP_KERNEL);
345 if (!peer)
346 return -ENOMEM;
347
348 for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
349 if (peer == alist->addrs[i].peer) {
350 rxrpc_kernel_put_peer(peer);
351 return 0;
352 }
353 if (peer <= alist->addrs[i].peer)
354 break;
355 }
356
357 if (i < alist->nr_addrs)
358 memmove(alist->addrs + i + 1,
359 alist->addrs + i,
360 sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
361 alist->addrs[i].peer = peer;
362 alist->nr_addrs++;
363 return 0;
364}
1// SPDX-License-Identifier: GPL-2.0-or-later
2/* Server address list management
3 *
4 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
6 */
7
8#include <linux/slab.h>
9#include <linux/ctype.h>
10#include <linux/dns_resolver.h>
11#include <linux/inet.h>
12#include <keys/rxrpc-type.h>
13#include "internal.h"
14#include "afs_fs.h"
15
16/*
17 * Release an address list.
18 */
19void afs_put_addrlist(struct afs_addr_list *alist)
20{
21 if (alist && refcount_dec_and_test(&alist->usage))
22 kfree_rcu(alist, rcu);
23}
24
25/*
26 * Allocate an address list.
27 */
28struct afs_addr_list *afs_alloc_addrlist(unsigned int nr,
29 unsigned short service,
30 unsigned short port)
31{
32 struct afs_addr_list *alist;
33 unsigned int i;
34
35 _enter("%u,%u,%u", nr, service, port);
36
37 if (nr > AFS_MAX_ADDRESSES)
38 nr = AFS_MAX_ADDRESSES;
39
40 alist = kzalloc(struct_size(alist, addrs, nr), GFP_KERNEL);
41 if (!alist)
42 return NULL;
43
44 refcount_set(&alist->usage, 1);
45 alist->max_addrs = nr;
46
47 for (i = 0; i < nr; i++) {
48 struct sockaddr_rxrpc *srx = &alist->addrs[i];
49 srx->srx_family = AF_RXRPC;
50 srx->srx_service = service;
51 srx->transport_type = SOCK_DGRAM;
52 srx->transport_len = sizeof(srx->transport.sin6);
53 srx->transport.sin6.sin6_family = AF_INET6;
54 srx->transport.sin6.sin6_port = htons(port);
55 }
56
57 return alist;
58}
59
60/*
61 * Parse a text string consisting of delimited addresses.
62 */
63struct 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)
68{
69 struct afs_vlserver_list *vllist;
70 struct afs_addr_list *alist;
71 const char *p, *end = text + len;
72 const char *problem;
73 unsigned int nr = 0;
74 int ret = -ENOMEM;
75
76 _enter("%*.*s,%c", (int)len, (int)len, text, delim);
77
78 if (!len) {
79 _leave(" = -EDESTADDRREQ [empty]");
80 return ERR_PTR(-EDESTADDRREQ);
81 }
82
83 if (delim == ':' && (memchr(text, ',', len) || !memchr(text, '.', len)))
84 delim = ',';
85
86 /* Count the addresses */
87 p = text;
88 do {
89 if (!*p) {
90 problem = "nul";
91 goto inval;
92 }
93 if (*p == delim)
94 continue;
95 nr++;
96 if (*p == '[') {
97 p++;
98 if (p == end) {
99 problem = "brace1";
100 goto inval;
101 }
102 p = memchr(p, ']', end - p);
103 if (!p) {
104 problem = "brace2";
105 goto inval;
106 }
107 p++;
108 if (p >= end)
109 break;
110 }
111
112 p = memchr(p, delim, end - p);
113 if (!p)
114 break;
115 p++;
116 } while (p < end);
117
118 _debug("%u/%u addresses", nr, AFS_MAX_ADDRESSES);
119
120 vllist = afs_alloc_vlserver_list(1);
121 if (!vllist)
122 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;
132
133 /* Extract the addresses */
134 p = text;
135 do {
136 const char *q, *stop;
137 unsigned int xport = port;
138 __be32 x[4];
139 int family;
140
141 if (*p == delim) {
142 p++;
143 continue;
144 }
145
146 if (*p == '[') {
147 p++;
148 q = memchr(p, ']', end - p);
149 } else {
150 for (q = p; q < end; q++)
151 if (*q == '+' || *q == delim)
152 break;
153 }
154
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;
159 } else {
160 problem = "family";
161 goto bad_address;
162 }
163
164 p = q;
165 if (stop != p) {
166 problem = "nostop";
167 goto bad_address;
168 }
169
170 if (q < end && *q == ']')
171 p++;
172
173 if (p < end) {
174 if (*p == '+') {
175 /* Port number specification "+1234" */
176 xport = 0;
177 p++;
178 if (p >= end || !isdigit(*p)) {
179 problem = "port";
180 goto bad_address;
181 }
182 do {
183 xport *= 10;
184 xport += *p - '0';
185 if (xport > 65535) {
186 problem = "pval";
187 goto bad_address;
188 }
189 p++;
190 } while (p < end && isdigit(*p));
191 } else if (*p == delim) {
192 p++;
193 } else {
194 problem = "weird";
195 goto bad_address;
196 }
197 }
198
199 if (family == AF_INET)
200 afs_merge_fs_addr4(alist, x[0], xport);
201 else
202 afs_merge_fs_addr6(alist, x, xport);
203
204 } while (p < end);
205
206 rcu_assign_pointer(vllist->servers[0].server->addresses, alist);
207 _leave(" = [nr %u]", alist->nr_addrs);
208 return vllist;
209
210inval:
211 _leave(" = -EINVAL [%s %zu %*.*s]",
212 problem, p - text, (int)len, (int)len, text);
213 return ERR_PTR(-EINVAL);
214bad_address:
215 _leave(" = -EINVAL [%s %zu %*.*s]",
216 problem, p - text, (int)len, (int)len, text);
217 ret = -EINVAL;
218error:
219 afs_put_addrlist(alist);
220error_vl:
221 afs_put_vlserverlist(net, vllist);
222 return ERR_PTR(ret);
223}
224
225/*
226 * Compare old and new address lists to see if there's been any change.
227 * - How to do this in better than O(Nlog(N)) time?
228 * - We don't really want to sort the address list, but would rather take the
229 * list as we got it so as not to undo record rotation by the DNS server.
230 */
231#if 0
232static int afs_cmp_addr_list(const struct afs_addr_list *a1,
233 const struct afs_addr_list *a2)
234{
235}
236#endif
237
238/*
239 * Perform a DNS query for VL servers and build a up an address list.
240 */
241struct afs_vlserver_list *afs_dns_query(struct afs_cell *cell, time64_t *_expiry)
242{
243 struct afs_vlserver_list *vllist;
244 char *result = NULL;
245 int ret;
246
247 _enter("%s", cell->name);
248
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);
253 return ERR_PTR(ret);
254 }
255
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;
269}
270
271/*
272 * Merge an IPv4 entry into a fileserver address list.
273 */
274void afs_merge_fs_addr4(struct afs_addr_list *alist, __be32 xdr, u16 port)
275{
276 struct sockaddr_rxrpc *srx;
277 u32 addr = ntohl(xdr);
278 int i;
279
280 if (alist->nr_addrs >= alist->max_addrs)
281 return;
282
283 for (i = 0; i < alist->nr_ipv4; i++) {
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)
289 return;
290 if (addr == a_addr && port < a_port)
291 break;
292 if (addr < a_addr)
293 break;
294 }
295
296 if (i < alist->nr_addrs)
297 memmove(alist->addrs + i + 1,
298 alist->addrs + i,
299 sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
300
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;
308 alist->nr_ipv4++;
309 alist->nr_addrs++;
310}
311
312/*
313 * Merge an IPv6 entry into a fileserver address list.
314 */
315void afs_merge_fs_addr6(struct afs_addr_list *alist, __be32 *xdr, u16 port)
316{
317 struct sockaddr_rxrpc *srx;
318 int i, diff;
319
320 if (alist->nr_addrs >= alist->max_addrs)
321 return;
322
323 for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
324 struct sockaddr_in6 *a = &alist->addrs[i].transport.sin6;
325 u16 a_port = ntohs(a->sin6_port);
326
327 diff = memcmp(xdr, &a->sin6_addr, 16);
328 if (diff == 0 && port == a_port)
329 return;
330 if (diff == 0 && port < a_port)
331 break;
332 if (diff < 0)
333 break;
334 }
335
336 if (i < alist->nr_addrs)
337 memmove(alist->addrs + i + 1,
338 alist->addrs + i,
339 sizeof(alist->addrs[0]) * (alist->nr_addrs - i));
340
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);
348 alist->nr_addrs++;
349}
350
351/*
352 * Get an address to try.
353 */
354bool afs_iterate_addresses(struct afs_addr_cursor *ac)
355{
356 unsigned long set, failed;
357 int index;
358
359 if (!ac->alist)
360 return false;
361
362 set = ac->alist->responded;
363 failed = ac->alist->failed;
364 _enter("%lx-%lx-%lx,%d", set, failed, ac->tried, ac->index);
365
366 ac->nr_iterations++;
367
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
379selected:
380 ac->index = index;
381 set_bit(index, &ac->tried);
382 ac->responded = false;
383 return true;
384}
385
386/*
387 * Release an address list cursor.
388 */
389int afs_end_cursor(struct afs_addr_cursor *ac)
390{
391 struct afs_addr_list *alist;
392
393 alist = ac->alist;
394 if (alist) {
395 if (ac->responded &&
396 ac->index != alist->preferred &&
397 test_bit(ac->alist->preferred, &ac->tried))
398 WRITE_ONCE(alist->preferred, ac->index);
399 afs_put_addrlist(alist);
400 ac->alist = NULL;
401 }
402
403 return ac->error;
404}