--- /dev/null
+// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
+// vim: ts=8 sw=2 smarttab
+/*
+ * Ceph - scalable distributed file system
+ *
+ * Copyright (C) 2016 SUSE LINUX GmbH
+ *
+ * This is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License version 2.1, as published by the Free Software
+ * Foundation. See file COPYING.
+ *
+ */
+
+#include <arpa/inet.h>
+
+#include "include/scope_guard.h"
+#include "dns_resolve.h"
+#include "common/debug.h"
+
+#define dout_subsys ceph_subsys_
+
+using namespace std;
+
+namespace ceph {
+
+#ifdef HAVE_RES_NQUERY
+
+int ResolvHWrapper::res_nquery(res_state s, const char *hostname, int cls,
+ int type, u_char *buf, int bufsz) {
+ return ::res_nquery(s, hostname, cls, type, buf, bufsz);
+}
+
+int ResolvHWrapper::res_nsearch(res_state s, const char *hostname, int cls,
+ int type, u_char *buf, int bufsz) {
+ return ::res_nsearch(s, hostname, cls, type, buf, bufsz);
+}
+
+#else
+
+int ResolvHWrapper::res_query(const char *hostname, int cls,
+ int type, u_char *buf, int bufsz) {
+ return ::res_query(hostname, cls, type, buf, bufsz);
+}
+
+int ResolvHWrapper::res_search(const char *hostname, int cls,
+ int type, u_char *buf, int bufsz) {
+ return ::res_search(hostname, cls, type, buf, bufsz);
+}
+
+#endif
+
+DNSResolver::~DNSResolver()
+{
+#ifdef HAVE_RES_NQUERY
+ list<res_state>::iterator iter;
+ for (iter = states.begin(); iter != states.end(); ++iter) {
+ struct __res_state *s = *iter;
+ delete s;
+ }
+#endif
+ delete resolv_h;
+}
+
+#ifdef HAVE_RES_NQUERY
+int DNSResolver::get_state(CephContext *cct, res_state *ps)
+{
+ lock.Lock();
+ if (!states.empty()) {
+ res_state s = states.front();
+ states.pop_front();
+ lock.Unlock();
+ *ps = s;
+ return 0;
+ }
+ lock.Unlock();
+ struct __res_state *s = new struct __res_state;
+ s->options = 0;
+ if (res_ninit(s) < 0) {
+ delete s;
+ lderr(cct) << "ERROR: failed to call res_ninit()" << dendl;
+ return -EINVAL;
+ }
+ *ps = s;
+ return 0;
+}
+
+void DNSResolver::put_state(res_state s)
+{
+ Mutex::Locker l(lock);
+ states.push_back(s);
+}
+#endif
+
+int DNSResolver::resolve_cname(CephContext *cct, const string& hostname,
+ string *cname, bool *found)
+{
+ *found = false;
+
+#ifdef HAVE_RES_NQUERY
+ res_state res;
+ int r = get_state(cct, &res);
+ if (r < 0) {
+ return r;
+ }
+ auto put_state = make_scope_guard([res, this] {
+ this->put_state(res);
+ });
+#endif
+
+#define LARGE_ENOUGH_DNS_BUFSIZE 1024
+ unsigned char buf[LARGE_ENOUGH_DNS_BUFSIZE];
+
+#define MAX_FQDN_SIZE 255
+ char host[MAX_FQDN_SIZE + 1];
+ const char *origname = hostname.c_str();
+ unsigned char *pt, *answer;
+ unsigned char *answend;
+ int len;
+
+#ifdef HAVE_RES_NQUERY
+ len = resolv_h->res_nquery(res, origname, ns_c_in, ns_t_cname, buf, sizeof(buf));
+#else
+ {
+# ifndef HAVE_THREAD_SAFE_RES_QUERY
+ Mutex::Locker l(lock);
+# endif
+ len = resolv_h->res_query(origname, ns_c_in, ns_t_cname, buf, sizeof(buf));
+ }
+#endif
+ if (len < 0) {
+ lderr(cct) << "res_query() failed" << dendl;
+ return 0;
+ }
+
+ answer = buf;
+ pt = answer + NS_HFIXEDSZ;
+ answend = answer + len;
+
+ /* read query */
+ if ((len = dn_expand(answer, answend, pt, host, sizeof(host))) < 0) {
+ lderr(cct) << "ERROR: dn_expand() failed" << dendl;
+ return -EINVAL;
+ }
+ pt += len;
+
+ if (pt + 4 > answend) {
+ lderr(cct) << "ERROR: bad reply" << dendl;
+ return -EIO;
+ }
+
+ int type;
+ NS_GET16(type, pt);
+
+ if (type != ns_t_cname) {
+ lderr(cct) << "ERROR: failed response type: type=" << type <<
+ " (was expecting " << ns_t_cname << ")" << dendl;
+ return -EIO;
+ }
+
+ pt += NS_INT16SZ; /* class */
+
+ /* read answer */
+ if ((len = dn_expand(answer, answend, pt, host, sizeof(host))) < 0) {
+ return 0;
+ }
+ pt += len;
+ ldout(cct, 20) << "name=" << host << dendl;
+
+ if (pt + 10 > answend) {
+ lderr(cct) << "ERROR: bad reply" << dendl;
+ return -EIO;
+ }
+
+ NS_GET16(type, pt);
+ pt += NS_INT16SZ; /* class */
+ pt += NS_INT32SZ; /* ttl */
+ pt += NS_INT16SZ; /* size */
+
+ if ((len = dn_expand(answer, answend, pt, host, sizeof(host))) < 0) {
+ return 0;
+ }
+ ldout(cct, 20) << "cname host=" << host << dendl;
+ *cname = host;
+
+ *found = true;
+ return 0;
+}
+
+
+int DNSResolver::resolve_ip_addr(CephContext *cct, const string& hostname,
+ entity_addr_t *addr) {
+
+#ifdef HAVE_RES_NQUERY
+ res_state res;
+ int r = get_state(cct, &res);
+ if (r < 0) {
+ return r;
+ }
+ return this->resolve_ip_addr(cct, &res, hostname, addr);
+#else
+ return this->resolve_ip_addr(cct, NULL, hostname, addr);
+#endif
+
+}
+
+int DNSResolver::resolve_ip_addr(CephContext *cct, res_state *res, const string& hostname,
+ entity_addr_t *addr) {
+
+ u_char nsbuf[NS_PACKETSZ];
+ int len;
+
+
+#ifdef HAVE_RES_NQUERY
+ len = resolv_h->res_nquery(*res, hostname.c_str(), ns_c_in, ns_t_a, nsbuf, sizeof(nsbuf));
+#else
+ {
+# ifndef HAVE_THREAD_SAFE_RES_QUERY
+ Mutex::Locker l(lock);
+# endif
+ len = resolv_h->res_query(hostname.c_str(), ns_c_in, ns_t_a, nsbuf, sizeof(nsbuf));
+ }
+#endif
+ if (len < 0) {
+ lderr(cct) << "res_query() failed" << dendl;
+ return len;
+ }
+ else if (len == 0) {
+ ldout(cct, 20) << "no address found for hostname " << hostname << dendl;
+ return -1;
+ }
+
+ ns_msg handle;
+ ns_initparse(nsbuf, len, &handle);
+
+ if (ns_msg_count(handle, ns_s_an) == 0) {
+ ldout(cct, 20) << "no address found for hostname " << hostname << dendl;
+ return -1;
+ }
+
+ ns_rr rr;
+ int r;
+ if ((r = ns_parserr(&handle, ns_s_an, 0, &rr)) < 0) {
+ lderr(cct) << "error while parsing DNS record" << dendl;
+ return r;
+ }
+
+ char addr_buf[64];
+ memset(addr_buf, 0, sizeof(addr_buf));
+ inet_ntop(AF_INET, ns_rr_rdata(rr), addr_buf, sizeof(addr_buf));
+ if (!addr->parse(addr_buf)) {
+ lderr(cct) << "failed to parse address '" << (const char *)ns_rr_rdata(rr)
+ << "'" << dendl;
+ return -1;
+ }
+
+ return 0;
+}
+
+int DNSResolver::resolve_srv_hosts(CephContext *cct, const string& service_name,
+ const SRV_Protocol trans_protocol,
+ map<string, DNSResolver::Record> *srv_hosts) {
+ return this->resolve_srv_hosts(cct, service_name, trans_protocol, "", srv_hosts);
+}
+
+int DNSResolver::resolve_srv_hosts(CephContext *cct, const string& service_name,
+ const SRV_Protocol trans_protocol, const string& domain,
+ map<string, DNSResolver::Record> *srv_hosts) {
+
+#ifdef HAVE_RES_NQUERY
+ res_state res;
+ int r = get_state(cct, &res);
+ if (r < 0) {
+ return r;
+ }
+ auto put_state = make_scope_guard([res, this] {
+ this->put_state(res);
+ });
+#endif
+
+ u_char nsbuf[NS_PACKETSZ];
+ int num_hosts;
+
+ string proto_str = srv_protocol_to_str(trans_protocol);
+ string query_str = "_"+service_name+"._"+proto_str+(domain.empty() ? ""
+ : "."+domain);
+ int len;
+
+#ifdef HAVE_RES_NQUERY
+ len = resolv_h->res_nsearch(res, query_str.c_str(), ns_c_in, ns_t_srv, nsbuf,
+ sizeof(nsbuf));
+#else
+ {
+# ifndef HAVE_THREAD_SAFE_RES_QUERY
+ Mutex::Locker l(lock);
+# endif
+ len = resolv_h->res_search(query_str.c_str(), ns_c_in, ns_t_srv, nsbuf,
+ sizeof(nsbuf));
+ }
+#endif
+ if (len < 0) {
+ lderr(cct) << "failed for service " << query_str << dendl;
+ return len;
+ }
+ else if (len == 0) {
+ ldout(cct, 20) << "No hosts found for service " << query_str << dendl;
+ return 0;
+ }
+
+ ns_msg handle;
+
+ ns_initparse(nsbuf, len, &handle);
+
+ num_hosts = ns_msg_count (handle, ns_s_an);
+ if (num_hosts == 0) {
+ ldout(cct, 20) << "No hosts found for service " << query_str << dendl;
+ return 0;
+ }
+
+ ns_rr rr;
+ char full_target[NS_MAXDNAME];
+
+ for (int i = 0; i < num_hosts; i++) {
+ int r;
+ if ((r = ns_parserr(&handle, ns_s_an, i, &rr)) < 0) {
+ lderr(cct) << "Error while parsing DNS record" << dendl;
+ return r;
+ }
+
+ string full_srv_name = ns_rr_name(rr);
+ string protocol = "_" + proto_str;
+ string srv_domain = full_srv_name.substr(full_srv_name.find(protocol)
+ + protocol.length());
+
+ auto rdata = ns_rr_rdata(rr);
+ uint16_t priority = ns_get16(rdata); rdata += NS_INT16SZ;
+ rdata += NS_INT16SZ; // weight
+ uint16_t port = ns_get16(rdata); rdata += NS_INT16SZ;
+ memset(full_target, 0, sizeof(full_target));
+ ns_name_uncompress(ns_msg_base(handle), ns_msg_end(handle),
+ rdata, full_target, sizeof(full_target));
+
+ entity_addr_t addr;
+#ifdef HAVE_RES_NQUERY
+ r = this->resolve_ip_addr(cct, &res, full_target, &addr);
+#else
+ r = this->resolve_ip_addr(cct, NULL, full_target, &addr);
+#endif
+
+ if (r == 0) {
+ addr.set_port(port);
+ string target = full_target;
+ auto end = target.find(srv_domain);
+ if (end == target.npos) {
+ lderr(cct) << "resolved target not in search domain: "
+ << target << " / " << srv_domain << dendl;
+ return -EINVAL;
+ }
+ target = target.substr(0, end);
+ (*srv_hosts)[target] = {priority, addr};
+ }
+ }
+ return 0;
+}
+
+}
Code Review / stor4nfv.git / blobdiff