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 | static 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(peer: alist->addrs[i].peer); |
23 | trace_afs_alist(alist_debug_id: alist->debug_id, ref: refcount_read(r: &alist->usage), reason: afs_alist_trace_free); |
24 | kfree(objp: alist); |
25 | } |
26 | |
27 | /* |
28 | * Release an address list. |
29 | */ |
30 | void 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(r: &alist->usage, oldp: &r); |
40 | trace_afs_alist(alist_debug_id: debug_id, ref: r - 1, reason); |
41 | if (dead) |
42 | call_rcu(head: &alist->rcu, func: afs_free_addrlist); |
43 | } |
44 | |
45 | struct 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(r: &alist->usage, oldp: &r); |
51 | trace_afs_alist(alist_debug_id: alist->debug_id, ref: r + 1, reason); |
52 | } |
53 | return alist; |
54 | } |
55 | |
56 | /* |
57 | * Allocate an address list. |
58 | */ |
59 | struct 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(r: &alist->usage, n: 1); |
74 | alist->max_addrs = nr; |
75 | alist->debug_id = atomic_inc_return(v: &debug_id); |
76 | trace_afs_alist(alist_debug_id: alist->debug_id, ref: 1, reason: afs_alist_trace_alloc); |
77 | return alist; |
78 | } |
79 | |
80 | /* |
81 | * Parse a text string consisting of delimited addresses. |
82 | */ |
83 | struct 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(error: -EDESTADDRREQ); |
101 | } |
102 | |
103 | if (delim == ':' && (memchr(p: text, c: ',', size: len) || !memchr(p: text, c: '.', size: 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, c: ']', size: 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, c: delim, size: 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(error: -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, c: ']', size: end - p); |
169 | } else { |
170 | for (q = p; q < end; q++) |
171 | if (*q == '+' || *q == delim) |
172 | break; |
173 | } |
174 | |
175 | if (in4_pton(src: p, srclen: q - p, dst: (u8 *)&x[0], delim: -1, end: &stop)) { |
176 | family = AF_INET; |
177 | } else if (in6_pton(src: p, srclen: q - p, dst: (u8 *)x, delim: -1, end: &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(c: *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(c: *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, addr: alist, xdr: x[0], port: xport); |
221 | else |
222 | ret = afs_merge_fs_addr6(net, addr: alist, xdr: x, port: 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 | |
232 | inval: |
233 | _leave(" = -EINVAL [%s %zu %*.*s]" , |
234 | problem, p - text, (int)len, (int)len, text); |
235 | return ERR_PTR(error: -EINVAL); |
236 | bad_address: |
237 | _leave(" = -EINVAL [%s %zu %*.*s]" , |
238 | problem, p - text, (int)len, (int)len, text); |
239 | ret = -EINVAL; |
240 | error: |
241 | afs_put_addrlist(alist, reason: afs_alist_trace_put_parse_error); |
242 | error_vl: |
243 | afs_put_vlserverlist(net, vllist); |
244 | return ERR_PTR(error: ret); |
245 | } |
246 | |
247 | /* |
248 | * Perform a DNS query for VL servers and build a up an address list. |
249 | */ |
250 | struct 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(net: cell->net->net, type: "afsdb" , name: cell->name, namelen: cell->name_len, |
259 | options: "srv=1" , result: &result, _expiry, invalidate: true); |
260 | if (ret < 0) { |
261 | _leave(" = %d [dns]" , ret); |
262 | return ERR_PTR(error: 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(net: cell->net, text: result, len: ret, delim: ',', |
272 | VL_SERVICE, AFS_VL_PORT); |
273 | kfree(objp: result); |
274 | if (IS_ERR(ptr: vllist) && vllist != ERR_PTR(error: -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 | */ |
283 | int 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(sock: net->socket, srx: &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 | */ |
327 | int 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(sock: net->socket, srx: &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 | } |
365 | |