From fc1f7fa97e441e4c09b5087ea673b64c1b82fb27 Mon Sep 17 00:00:00 2001
From: Aki Tuomi <cmouse@cmouse.fi>
Date: Fri, 30 Nov 2018 11:49:14 +0200
Subject: [PATCH] pdns_notify: Support hostname for notification

When hostname is provided, attempts to send NOTIFY to all
addresses associated with the given hostname.
---
 pdns/notify.cc | 71 ++++++++++++++++++++++++++++++++++----------------
 1 file changed, 48 insertions(+), 23 deletions(-)

diff --git a/pdns/notify.cc b/pdns/notify.cc
index 8e75e822e..270aaad36 100644
--- a/pdns/notify.cc
+++ b/pdns/notify.cc
@@ -58,6 +58,7 @@ void usage() {
 int main(int argc, char** argv)
 try
 {
+  set<ComboAddress> addrs;
 
   for(int n=1 ; n < argc; ++n) {
     if ((string) argv[n] == "--help") {
@@ -76,39 +77,63 @@ try
     exit(1);
   }
 
-  int sock = socket(AF_INET, SOCK_DGRAM, 0);
-  if(sock < 0)
-    throw runtime_error("Creating socket for incoming packets: "+stringerror());
-
+  int sock = -1;
 
  // ComboAddress local("127.0.0.1", (int)0);
 //  if(::bind(sock, (struct sockaddr*) &local, local.getSocklen()) < 0) 
 //    throw runtime_error("Failed to bind local socket to address "+local.toString()+": "+stringerror());
 
-  ComboAddress pdns(argv[1], 53);
-  if(connect(sock, (struct sockaddr*) &pdns, pdns.getSocklen()) < 0) 
-    throw runtime_error("Failed to connect PowerDNS socket to address "+pdns.toString()+": "+stringerror());
-  
-  vector<uint8_t> outpacket;
-  DNSPacketWriter pw(outpacket, DNSName(argv[2]), QType::SOA, 1, Opcode::Notify);
-  pw.getHeader()->id = random();
+  try {
+     addrs.emplace(ComboAddress{argv[1], 53});
+  } catch (PDNSException &ex) {
+     /* needs resolving, maybe */
+     struct addrinfo *info;
+     vector<string> parts;
+     boost::split(parts, argv[1], [](char c){return c == ':';});
+     if (parts.size() == 1)
+       parts.push_back("domain");
+     else if (parts.size() != 2)
+       throw runtime_error("Invalid hostname:port syntax");
+     if (getaddrinfo(parts[0].c_str(), parts[1].c_str(), NULL, &info) < 0)
+       throw runtime_error("Cannot resolve '" + string(argv[1]) +"'");
+     for(auto ptr = info; ptr != NULL; ptr = ptr->ai_next)
+       addrs.emplace(ComboAddress{ptr->ai_addr, ptr->ai_addrlen});
+  }
 
+  for(const auto &addr: addrs) {
+    if (sock > -1)
+      (void)close(sock);
+    sock = socket(addr.sin4.sin_family, SOCK_DGRAM, 0);
+    if(sock < 0)
+      throw runtime_error("Creating socket for incoming packets: "+stringerror());
+    if(connect(sock, (struct sockaddr*)&addr, addr.getSocklen()) < 0) {
+      cerr<<"Failed to connect PowerDNS socket to address "+addr.toString()+": "+stringerror()<<endl;
+      continue;
+    }
+    vector<uint8_t> outpacket;
+    DNSPacketWriter pw(outpacket, DNSName(argv[2]), QType::SOA, 1, Opcode::Notify);
+    pw.getHeader()->id = random();
 
-  if(send(sock, &outpacket[0], outpacket.size(), 0) < 0) {
-    throw runtime_error("Unable to send notify to PowerDNS: "+stringerror());
-  }
-  
-  char buffer[1500];
 
-  int len=recv(sock, buffer, sizeof(buffer),0);
-  if(len < 0)
-    throw runtime_error("Unable to receive notification response from PowerDNS: "+stringerror());
+    if(send(sock, &outpacket[0], outpacket.size(), 0) < 0) {
+      cerr<<"Unable to send notify to PowerDNS: "+stringerror()<<endl;
+      continue;
+    }
 
-  string packet(buffer, len);
-  MOADNSParser mdp(false, packet);
+    char buffer[1500];
 
-  cerr<<"Received notification response with error: "<<RCode::to_s(mdp.d_header.rcode)<<endl;
-  cerr<<"For: '"<<mdp.d_qname<<"'"<<endl;
+    int len=recv(sock, buffer, sizeof(buffer),0);
+    if(len < 0) {
+      cerr<<"Unable to receive notification response from PowerDNS: "+stringerror()<<endl;
+      continue;
+    }
+
+    string packet(buffer, len);
+    MOADNSParser mdp(false, packet);
+
+    cerr<<addr.toString()<<": Received notification response with error: "<<RCode::to_s(mdp.d_header.rcode)<<endl;
+    cerr<<"For: '"<<mdp.d_qname<<"'"<<endl;
+  }
 }
 catch(std::exception& e)
 {
-- 
2.40.0