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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:54:28 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-21 11:54:28 +0000
commite6918187568dbd01842d8d1d2c808ce16a894239 (patch)
tree64f88b554b444a49f656b6c656111a145cbbaa28 /src/common/dns_resolve.h
parentInitial commit. (diff)
downloadceph-e6918187568dbd01842d8d1d2c808ce16a894239.tar.xz
ceph-e6918187568dbd01842d8d1d2c808ce16a894239.zip
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/common/dns_resolve.h')
-rw-r--r--src/common/dns_resolve.h167
1 files changed, 167 insertions, 0 deletions
diff --git a/src/common/dns_resolve.h b/src/common/dns_resolve.h
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+// -*- 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.
+ *
+ */
+#ifndef CEPH_DNS_RESOLVE_H
+#define CEPH_DNS_RESOLVE_H
+
+#include <netinet/in.h>
+#ifndef _WIN32
+#include <resolv.h>
+#endif
+
+#include "common/ceph_mutex.h"
+#include "msg/msg_types.h" // for entity_addr_t
+
+namespace ceph {
+
+/**
+ * this class is used to facilitate the testing of
+ * resolv.h functions.
+ */
+class ResolvHWrapper {
+ public:
+ virtual ~ResolvHWrapper() {}
+
+#ifdef HAVE_RES_NQUERY
+ virtual int res_nquery(res_state s, const char *hostname, int cls, int type,
+ u_char *buf, int bufsz);
+
+ virtual int res_nsearch(res_state s, const char *hostname, int cls, int type,
+ u_char *buf, int bufsz);
+#else
+ virtual int res_query(const char *hostname, int cls, int type,
+ u_char *buf, int bufsz);
+
+ virtual int res_search(const char *hostname, int cls, int type,
+ u_char *buf, int bufsz);
+#endif
+
+};
+
+
+/**
+ * @class DNSResolver
+ *
+ * This is a singleton class that exposes the functionality of DNS querying.
+ */
+class DNSResolver {
+
+ public:
+ // singleton declaration
+ static DNSResolver *get_instance()
+ {
+ static DNSResolver instance;
+ return &instance;
+ }
+ DNSResolver(DNSResolver const&) = delete;
+ void operator=(DNSResolver const&) = delete;
+
+ // this function is used by the unit test
+ static DNSResolver *get_instance(ResolvHWrapper *resolv_wrapper) {
+ DNSResolver *resolv = DNSResolver::get_instance();
+ delete resolv->resolv_h;
+ resolv->resolv_h = resolv_wrapper;
+ return resolv;
+ }
+
+ enum class SRV_Protocol {
+ TCP, UDP
+ };
+
+
+ struct Record {
+ uint16_t priority;
+ uint16_t weight;
+ entity_addr_t addr;
+ };
+
+ int resolve_cname(CephContext *cct, const std::string& hostname,
+ std::string *cname, bool *found);
+
+ /**
+ * Resolves the address given a hostname.
+ *
+ * @param hostname the hostname to resolved
+ * @param[out] addr the hostname's address
+ * @returns 0 on success, negative error code on failure
+ */
+ int resolve_ip_addr(CephContext *cct, const std::string& hostname,
+ entity_addr_t *addr);
+
+ /**
+ * Returns the list of hostnames and addresses that provide a given
+ * service configured as DNS SRV records.
+ *
+ * @param service_name the service name
+ * @param trans_protocol the IP protocol used by the service (TCP or UDP)
+ * @param[out] srv_hosts the hostname to address map of available hosts
+ * providing the service. If no host exists the map is not
+ * changed.
+ * @returns 0 on success, negative error code on failure
+ */
+ int resolve_srv_hosts(CephContext *cct, const std::string& service_name,
+ const SRV_Protocol trans_protocol, std::map<std::string, Record> *srv_hosts);
+
+ /**
+ * Returns the list of hostnames and addresses that provide a given
+ * service configured as DNS SRV records.
+ *
+ * @param service_name the service name
+ * @param trans_protocol the IP protocol used by the service (TCP or UDP)
+ * @param domain the domain of the service
+ * @param[out] srv_hosts the hostname to address map of available hosts
+ * providing the service. If no host exists the map is not
+ * changed.
+ * @returns 0 on success, negative error code on failure
+ */
+ int resolve_srv_hosts(CephContext *cct, const std::string& service_name,
+ const SRV_Protocol trans_protocol, const std::string& domain,
+ std::map<std::string, Record> *srv_hosts);
+
+ private:
+ DNSResolver() { resolv_h = new ResolvHWrapper(); }
+ ~DNSResolver();
+
+ ceph::mutex lock = ceph::make_mutex("DNSResolver::lock");
+ ResolvHWrapper *resolv_h;
+#ifdef HAVE_RES_NQUERY
+ std::list<res_state> states;
+
+ int get_state(CephContext *cct, res_state *ps);
+ void put_state(res_state s);
+#endif
+
+#ifndef _WIN32
+ /* this private function allows to reuse the res_state structure used
+ * by other function of this class
+ */
+ int resolve_ip_addr(CephContext *cct, res_state *res,
+ const std::string& hostname, entity_addr_t *addr);
+#endif
+
+ std::string srv_protocol_to_str(SRV_Protocol proto) {
+ switch (proto) {
+ case SRV_Protocol::TCP:
+ return "tcp";
+ case SRV_Protocol::UDP:
+ return "udp";
+ }
+ return "";
+ }
+
+};
+
+}
+
+#endif
+