From f7de8573f5521263449fd80a2d5cdf3901b96087 Mon Sep 17 00:00:00 2001
From: John Denker <jsd@av8n.com>
Date: Sat, 24 Nov 2012 19:40:13 -0800
Subject: Now can check to see if hostnames map to observed IP

---
 tools/libskrewt.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 85 insertions(+), 8 deletions(-)

(limited to 'tools/libskrewt.c')

diff --git a/tools/libskrewt.c b/tools/libskrewt.c
index 3c820f1..d93a9e1 100644
--- a/tools/libskrewt.c
+++ b/tools/libskrewt.c
@@ -214,12 +214,7 @@ int skrewt::dump_bigbuf(std::ostream& xout){
   return 0;
 }
 
-void check_name(name_tester& fqdn, const string ip) {
-   if (ip == "") {
-     cerr << "SPF: should never happen: email with no IP?" <<endl;
-     fqdn.spf = fqdn.map2ip = neutral;
-     return;
-   }
+void check_spf(name_tester& fqdn, const string ip) {
    sepofra my_spf;
    try {
      my_spf.check(ip,
@@ -238,6 +233,88 @@ void check_name(name_tester& fqdn, const string ip) {
    }
 }
 
+void check_map2ip(name_tester& fqdn, const string ipstr) {
+  if (ipstr.length() == 0) {
+    cerr << progid << " check_map2ip: no addr specified." << endl;
+    fqdn.map2ip = fail;
+    return;
+  }
+
+// convert address-as-string to address-as-bits.
+// also get information about family
+  struct addrinfo *ipresult;
+  struct addrinfo *result;
+  addrinfo hints;
+  int error;
+
+  memset(&hints, 0, sizeof(struct addrinfo));
+  // restrict to TCP only; otherwise we get N records per address
+  hints.ai_protocol = IPPROTO_TCP;
+
+  error = getaddrinfo(ipstr.c_str(), NULL, &hints, &ipresult);
+  // EAI_NONAME covers the case of malformed IP address
+  // e.g. 1.2.3.4.5
+  if (error == EAI_NONAME) {
+    fqdn.map2ip = fail;
+    return;
+  }
+  if (error) {          // some unexpected error
+    cerr << progid
+      << " odd error " << error
+      << "  in getaddrinfo for " << ipstr
+      << " : " << gai_strerror(error) << endl;
+    fqdn.map2ip = fail;
+    return;
+  }
+  if (!ipresult) {
+    cerr << progid
+         <<" ??? should never happen (ipstr with no ipbits?)" << endl;
+    fqdn.map2ip = fail;
+    return;
+  }
+
+  error = getaddrinfo(fqdn.name.c_str(), NULL, &hints, &result);
+  if (error == EAI_NONAME) {
+    // malformed name, or no address for name
+    fqdn.map2ip = fail;
+    return;
+  }
+  if (error) {
+    cerr << progid
+      << "  getaddrinfo for " << fqdn.name
+      << " error " << error
+      << " i.e. " << gai_strerror(error) << endl;
+    fqdn.map2ip = fail;
+    return;
+  }
+
+// loop over all returned results and check for a match.
+  for (struct addrinfo *res = result; res != NULL; res = res->ai_next){
+    if (memcmp(res->ai_addr, ipresult->ai_addr, res->ai_addrlen) == 0) {
+      // match!
+      goto done;
+    }
+  }
+  // here if no match
+  fqdn.map2ip = fail;
+  return;
+done:
+  fqdn.map2ip = pass;
+  return;
+}
+
+void check_name_ip(name_tester& fqdn, const string ip) {
+   if (ip == "") {
+     cerr << "check_nane_ip: should never happen: email with no IP?" <<endl;
+     fqdn.spf = fqdn.map2ip = neutral;
+     return;
+   }
+   check_spf(fqdn, ip);
+   check_map2ip(fqdn, ip);
+}
+
+
+
 int skrewt::interstage(){
   if (saw_blank_line) {/* ignore */}
 // Note that the headers are in reverse-chronological order.
@@ -253,8 +330,8 @@ int skrewt::interstage(){
     if (rslt) return rslt;
     if (proximta_AuthUser == "") {
 // FIXME:  also check return-path aka envelope-from
-      check_name(proximta_HELO, proximta_IP);
-      check_name(proximta_rDNS, proximta_IP);
+      check_name_ip(proximta_HELO, proximta_IP);
+      check_name_ip(proximta_rDNS, proximta_IP);
     }
 
     cerr << progid << " === rDNS:     "  << proximta_rDNS.name
-- 
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