1 // -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
2 // vim: ts=8 sw=2 smarttab
3 /*
4 * Ceph - scalable distributed file system
5 *
6 * Copyright (C) 2016 SUSE LINUX GmbH
7 *
8 * This is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License version 2.1, as published by the Free Software
11 * Foundation. See file COPYING.
12 *
13 */
14
15 #include <arpa/inet.h>
16
17 #include "include/scope_guard.h"
18 #include "dns_resolve.h"
19 #include "common/debug.h"
20
21 #define dout_subsys ceph_subsys_
22
23
24 namespace ceph {
25
26 #ifdef HAVE_RES_NQUERY
27
28 int ResolvHWrapper::res_nquery(res_state s, const char *hostname, int cls,
29 int type, u_char *buf, int bufsz) {
30 return ::res_nquery(s, hostname, cls, type, buf, bufsz);
31 }
32
33 int ResolvHWrapper::res_nsearch(res_state s, const char *hostname, int cls,
34 int type, u_char *buf, int bufsz) {
35 return ::res_nsearch(s, hostname, cls, type, buf, bufsz);
36 }
37
38 #else
39
40 int ResolvHWrapper::res_query(const char *hostname, int cls,
41 int type, u_char *buf, int bufsz) {
42 return ::res_query(hostname, cls, type, buf, bufsz);
43 }
44
45 int ResolvHWrapper::res_search(const char *hostname, int cls,
46 int type, u_char *buf, int bufsz) {
47 return ::res_search(hostname, cls, type, buf, bufsz);
48 }
49
50 #endif
51
52 DNSResolver::~DNSResolver()
53 {
54 #ifdef HAVE_RES_NQUERY
55 list<res_state>::iterator iter;
56 for (iter = states.begin(); iter != states.end(); ++iter) {
57 struct __res_state *s = *iter;
58 delete s;
59 }
60 #endif
61 delete resolv_h;
62 }
63
64 #ifdef HAVE_RES_NQUERY
65 int DNSResolver::get_state(CephContext *cct, res_state *ps)
66 {
67 lock.lock();
68 if (!states.empty()) {
69 res_state s = states.front();
70 states.pop_front();
71 lock.unlock();
72 *ps = s;
73 return 0;
74 }
75 lock.unlock();
76 struct __res_state *s = new struct __res_state;
77 s->options = 0;
78 if (res_ninit(s) < 0) {
79 delete s;
80 lderr(cct) << "ERROR: failed to call res_ninit()" << dendl;
81 return -EINVAL;
82 }
83 *ps = s;
84 return 0;
85 }
86
87 void DNSResolver::put_state(res_state s)
88 {
|
(1) Event fun_call_w_exception: |
Called function throws an exception of type "_ZN5boost16exception_detail10clone_implINS0_19error_info_injectorINSt8ios_base7failureB5cxx11EEEEE". [details] |
89 std::lock_guard l(lock);
90 states.push_back(s);
91 }
92 #endif
93
94 int DNSResolver::resolve_cname(CephContext *cct, const string& hostname,
95 string *cname, bool *found)
96 {
97 *found = false;
98
99 #ifdef HAVE_RES_NQUERY
100 res_state res;
101 int r = get_state(cct, &res);
102 if (r < 0) {
103 return r;
104 }
105 auto put_state = make_scope_guard([res, this] {
106 this->put_state(res);
107 });
108 #endif
109
110 #define LARGE_ENOUGH_DNS_BUFSIZE 1024
111 unsigned char buf[LARGE_ENOUGH_DNS_BUFSIZE];
112
113 #define MAX_FQDN_SIZE 255
114 char host[MAX_FQDN_SIZE + 1];
115 const char *origname = hostname.c_str();
116 unsigned char *pt, *answer;
117 unsigned char *answend;
118 int len;
119
120 #ifdef HAVE_RES_NQUERY
121 len = resolv_h->res_nquery(res, origname, ns_c_in, ns_t_cname, buf, sizeof(buf));
122 #else
123 {
124 # ifndef HAVE_THREAD_SAFE_RES_QUERY
125 std::lock_guard l(lock);
126 # endif
127 len = resolv_h->res_query(origname, ns_c_in, ns_t_cname, buf, sizeof(buf));
128 }
129 #endif
130 if (len < 0) {
131 lderr(cct) << "res_query() failed" << dendl;
132 return 0;
133 }
134
135 answer = buf;
136 pt = answer + NS_HFIXEDSZ;
137 answend = answer + len;
138
139 /* read query */
140 if ((len = dn_expand(answer, answend, pt, host, sizeof(host))) < 0) {
141 lderr(cct) << "ERROR: dn_expand() failed" << dendl;
142 return -EINVAL;
143 }
144 pt += len;
145
146 if (pt + 4 > answend) {
147 lderr(cct) << "ERROR: bad reply" << dendl;
148 return -EIO;
149 }
150
151 int type;
152 NS_GET16(type, pt);
153
154 if (type != ns_t_cname) {
155 lderr(cct) << "ERROR: failed response type: type=" << type <<
156 " (was expecting " << ns_t_cname << ")" << dendl;
157 return -EIO;
158 }
159
160 pt += NS_INT16SZ; /* class */
161
162 /* read answer */
163 if ((len = dn_expand(answer, answend, pt, host, sizeof(host))) < 0) {
164 return 0;
165 }
166 pt += len;
167 ldout(cct, 20) << "name=" << host << dendl;
168
169 if (pt + 10 > answend) {
170 lderr(cct) << "ERROR: bad reply" << dendl;
171 return -EIO;
172 }
173
174 NS_GET16(type, pt);
175 pt += NS_INT16SZ; /* class */
176 pt += NS_INT32SZ; /* ttl */
177 pt += NS_INT16SZ; /* size */
178
179 if ((len = dn_expand(answer, answend, pt, host, sizeof(host))) < 0) {
180 return 0;
181 }
182 ldout(cct, 20) << "cname host=" << host << dendl;
183 *cname = host;
184
185 *found = true;
186 return 0;
187 }
188
189
190 int DNSResolver::resolve_ip_addr(CephContext *cct, const string& hostname,
191 entity_addr_t *addr) {
192
193 #ifdef HAVE_RES_NQUERY
194 res_state res;
195 int r = get_state(cct, &res);
196 if (r < 0) {
197 return r;
198 }
199 auto put_state = make_scope_guard([res, this] {
|
(1) Event fun_call_w_exception: |
Called function throws an exception of type "_ZN5boost16exception_detail10clone_implINS0_19error_info_injectorINSt8ios_base7failureB5cxx11EEEEE". [details] |
200 this->put_state(res);
201 });
202 return this->resolve_ip_addr(cct, &res, hostname, addr);
203 #else
204 return this->resolve_ip_addr(cct, NULL, hostname, addr);
205 #endif
206
207 }
208
209 int DNSResolver::resolve_ip_addr(CephContext *cct, res_state *res, const string& hostname,
210 entity_addr_t *addr) {
211
212 u_char nsbuf[NS_PACKETSZ];
213 int len;
214 int family = cct->_conf->ms_bind_ipv6 ? AF_INET6 : AF_INET;
215 int type = cct->_conf->ms_bind_ipv6 ? ns_t_aaaa : ns_t_a;
216
217 #ifdef HAVE_RES_NQUERY
218 len = resolv_h->res_nquery(*res, hostname.c_str(), ns_c_in, type, nsbuf, sizeof(nsbuf));
219 #else
220 {
221 # ifndef HAVE_THREAD_SAFE_RES_QUERY
222 std::lock_guard l(lock);
223 # endif
224 len = resolv_h->res_query(hostname.c_str(), ns_c_in, type, nsbuf, sizeof(nsbuf));
225 }
226 #endif
227 if (len < 0) {
228 lderr(cct) << "res_query() failed" << dendl;
229 return len;
230 }
231 else if (len == 0) {
232 ldout(cct, 20) << "no address found for hostname " << hostname << dendl;
233 return -1;
234 }
235
236 ns_msg handle;
237 ns_initparse(nsbuf, len, &handle);
238
239 if (ns_msg_count(handle, ns_s_an) == 0) {
240 ldout(cct, 20) << "no address found for hostname " << hostname << dendl;
241 return -1;
242 }
243
244 ns_rr rr;
245 int r;
246 if ((r = ns_parserr(&handle, ns_s_an, 0, &rr)) < 0) {
247 lderr(cct) << "error while parsing DNS record" << dendl;
248 return r;
249 }
250
251 char addr_buf[64];
252 memset(addr_buf, 0, sizeof(addr_buf));
253 inet_ntop(family, ns_rr_rdata(rr), addr_buf, sizeof(addr_buf));
254 if (!addr->parse(addr_buf)) {
255 lderr(cct) << "failed to parse address '" << (const char *)ns_rr_rdata(rr)
256 << "'" << dendl;
257 return -1;
258 }
259
260 return 0;
261 }
262
263 int DNSResolver::resolve_srv_hosts(CephContext *cct, const string& service_name,
264 const SRV_Protocol trans_protocol,
265 map<string, DNSResolver::Record> *srv_hosts) {
266 return this->resolve_srv_hosts(cct, service_name, trans_protocol, "", srv_hosts);
267 }
268
269 int DNSResolver::resolve_srv_hosts(CephContext *cct, const string& service_name,
270 const SRV_Protocol trans_protocol, const string& domain,
271 map<string, DNSResolver::Record> *srv_hosts) {
272
273 #ifdef HAVE_RES_NQUERY
274 res_state res;
275 int r = get_state(cct, &res);
276 if (r < 0) {
277 return r;
278 }
279 auto put_state = make_scope_guard([res, this] {
280 this->put_state(res);
281 });
282 #endif
283
284 u_char nsbuf[NS_PACKETSZ];
285 int num_hosts;
286
287 string proto_str = srv_protocol_to_str(trans_protocol);
288 string query_str = "_"+service_name+"._"+proto_str+(domain.empty() ? ""
289 : "."+domain);
290 int len;
291
292 #ifdef HAVE_RES_NQUERY
293 len = resolv_h->res_nsearch(res, query_str.c_str(), ns_c_in, ns_t_srv, nsbuf,
294 sizeof(nsbuf));
295 #else
296 {
297 # ifndef HAVE_THREAD_SAFE_RES_QUERY
298 std::lock_guard l(lock);
299 # endif
300 len = resolv_h->res_search(query_str.c_str(), ns_c_in, ns_t_srv, nsbuf,
301 sizeof(nsbuf));
302 }
303 #endif
304 if (len < 0) {
305 lderr(cct) << "failed for service " << query_str << dendl;
306 return len;
307 }
308 else if (len == 0) {
309 ldout(cct, 20) << "No hosts found for service " << query_str << dendl;
310 return 0;
311 }
312
313 ns_msg handle;
314
315 ns_initparse(nsbuf, len, &handle);
316
317 num_hosts = ns_msg_count (handle, ns_s_an);
318 if (num_hosts == 0) {
319 ldout(cct, 20) << "No hosts found for service " << query_str << dendl;
320 return 0;
321 }
322
323 ns_rr rr;
324 char full_target[NS_MAXDNAME];
325
326 for (int i = 0; i < num_hosts; i++) {
327 int r;
328 if ((r = ns_parserr(&handle, ns_s_an, i, &rr)) < 0) {
329 lderr(cct) << "Error while parsing DNS record" << dendl;
330 return r;
331 }
332
333 string full_srv_name = ns_rr_name(rr);
334 string protocol = "_" + proto_str;
335 string srv_domain = full_srv_name.substr(full_srv_name.find(protocol)
336 + protocol.length());
337
338 auto rdata = ns_rr_rdata(rr);
339 uint16_t priority = ns_get16(rdata); rdata += NS_INT16SZ;
340 uint16_t weight = ns_get16(rdata); rdata += NS_INT16SZ;
341 uint16_t port = ns_get16(rdata); rdata += NS_INT16SZ;
342 memset(full_target, 0, sizeof(full_target));
343 ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
344 rdata, full_target, sizeof(full_target));
345
346 entity_addr_t addr;
347 #ifdef HAVE_RES_NQUERY
348 r = this->resolve_ip_addr(cct, &res, full_target, &addr);
349 #else
350 r = this->resolve_ip_addr(cct, NULL, full_target, &addr);
351 #endif
352
353 if (r == 0) {
354 addr.set_port(port);
355 string target = full_target;
356 auto end = target.find(srv_domain);
357 if (end == target.npos) {
358 lderr(cct) << "resolved target not in search domain: "
359 << target << " / " << srv_domain << dendl;
360 return -EINVAL;
361 }
362 target = target.substr(0, end);
363 (*srv_hosts)[target] = {priority, weight, addr};
364 }
365 }
366 return 0;
367 }
368
369 }
370