X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=src%2Fceph%2Fsrc%2Fcommon%2Fdns_resolve.cc;fp=src%2Fceph%2Fsrc%2Fcommon%2Fdns_resolve.cc;h=13f06548e84d040a9ab17da1beb06dfb24430d6d;hb=812ff6ca9fcd3e629e49d4328905f33eee8ca3f5;hp=0000000000000000000000000000000000000000;hpb=15280273faafb77777eab341909a3f495cf248d9;p=stor4nfv.git

diff --git a/src/ceph/src/common/dns_resolve.cc b/src/ceph/src/common/dns_resolve.cc
new file mode 100644
index 0000000..13f0654
--- /dev/null
+++ b/src/ceph/src/common/dns_resolve.cc
@@ -0,0 +1,366 @@
+// -*- 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;
+}
+
+}