Parts of the upstream patch, adapted, plus a fix for a typo.

commit e36a4270122f690927d17f06259ce5a9308cd1eb
Author: arthur <arthur@ef36b2f9-881f-0410-afb5-c4e39611909c>
Date:   Wed Aug 24 18:51:55 2011 +0000

    support querying DNS SRV records from a different domain than the current one (based on a patch by James M. Leddy)
    
    git-svn-id: http://arthurdejong.org/svn/nss-pam-ldapd/nss-pam-ldapd@1513 ef36b2f9-881f-0410-afb5-c4e39611909c

diff --git a/man/nslcd.conf.5.xml b/man/nslcd.conf.5.xml
index 6c0f9e3..51869f4 100644
--- a/man/nslcd.conf.5.xml
+++ b/man/nslcd.conf.5.xml
@@ -127,9 +127,14 @@
        <acronym>LDAP</acronym> over <acronym>TCP</acronym>,
        <acronym>ICP</acronym> or <acronym>SSL</acronym> respectively (if
        supported by the <acronym>LDAP</acronym> library).
+      </para>
+      <para>
        Alternatively, the value <literal>DNS</literal> may be
        used to try to lookup the server using <acronym>DNS</acronym>
        <acronym>SRV</acronym> records.
+       By default the current domain is used but another domain can
+       be queried by using the
+       <literal>DNS:</literal><replaceable>DOMAIN</replaceable> syntax.
       </para>
       <para>
        When using the ldapi scheme, %2f should be used to escape slashes
diff --git a/nslcd/cfg.c b/nslcd/cfg.c
index fee3286..ac354c0 100644
--- a/nslcd/cfg.c
+++ b/nslcd/cfg.c
@@ -184,13 +184,13 @@ static const char *cfg_getdomainname(const char *filename,int lnr)
 
 /* add URIs by doing DNS queries for SRV records */
 static void add_uris_from_dns(const char *filename,int lnr,
-                              struct ldap_config *cfg)
+                              struct ldap_config *cfg,
+                              const char *domain)
 {
   int ret=0;
-  char *domain;
   char *hostlist=NULL,*nxt;
   char buf[HOST_NAME_MAX+sizeof("ldap://")];
-  domain=cfg_getdomainname(filename,lnr);
+  log_log(LOG_DEBUG,"query %s for SRV records",domain);
   ret=ldap_domain2hostlist(domain,&hostlist);
   /* FIXME: have better error handling */
   if ((hostlist==NULL)||(*hostlist=='\0'))
@@ -856,7 +856,16 @@ static void cfg_read(const char *filename,struct ldap_config *cfg)
         if (strcasecmp(token,"dns")==0)
         {
 #ifdef HAVE_LDAP_DOMAIN2HOSTLIST
-          add_uris_from_dns(filename,lnr,cfg);
+          add_uris_from_dns(filename,lnr,cfg,cfg_getdomainname(filename,lnr));
+#else /* not HAVE_LDAP_DOMAIN2HOSTLIST */
+          log_log(LOG_ERR,"%s:%d: value %s not supported on platform",filename,lnr,token);
+          exit(EXIT_FAILURE);
+#endif /* not HAVE_LDAP_DOMAIN2HOSTLIST */
+        }
+        else if (strncasecmp(token,"dns:",4)==0)
+        {
+#ifdef HAVE_LDAP_DOMAIN2HOSTLIST
+          add_uris_from_dns(filename,lnr,cfg,strdup(token+sizeof("dns")));
 #else /* not HAVE_LDAP_DOMAIN2HOSTLIST */
           log_log(LOG_ERR,"%s:%d: value %s not supported on platform",filename,lnr,token);
           exit(EXIT_FAILURE);