[PATCH] Add name_status_lmhosts

[Volker Lendecke]

Hi!

This is a pretty desparate hack to make winbind work in a special
environment. I'm happy if this is too special, but it did help me big
time.

Review appreciated!

Thanks, Volker
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>From b3b3cf12f846fcd0c539a6eed22e939ccfacb6a5 Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Mon, 19 Dec 2016 20:18:41 +0100
Subject: [PATCH] libsmb: Add name_status_lmhosts

Don't ask... Oh, you did? :-)

Try to figure out a hosts' name from lmhosts. This is for a setup I've
come across where for several reasons kerberos and ldap were unusable
(very organically grown but unchangeable Solaris 10 installation with
tons of ancient libs that ./configure incorrectly finds and where tar xf
samba-4.5.3.tar takes 5 minutes...), so I had to fall back to compile
with --without-ads. Unfortunately in that environment NetBIOS was also
turned off, but the "winbind rpc only" code relies on name_status to
get a DC's name from its IP address for the netlogon calls. This walks
the local lmhosts file to scan for the same information.

Signed-off-by: Volker Lendecke <vl at samba.org>
---
 source3/libsmb/namequery.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/source3/libsmb/namequery.c b/source3/libsmb/namequery.c
index 945fc64..e39d761 100644
--- a/source3/libsmb/namequery.c
+++ b/source3/libsmb/namequery.c
@@ -916,6 +916,42 @@ NTSTATUS node_status_query(TALLOC_CTX *mem_ctx, struct nmb_name *name,
 	return status;
 }
 
+static bool name_status_lmhosts(const struct sockaddr_storage *paddr,
+				int qname_type, fstring pname)
+{
+	FILE *f;
+	char *name;
+	int name_type;
+	struct sockaddr_storage addr;
+
+	if (paddr->ss_family != AF_INET) {
+		return false;
+	}
+
+	f = startlmhosts(get_dyn_LMHOSTSFILE());
+	if (f == NULL) {
+		return false;
+	}
+
+	while (getlmhostsent(talloc_tos(), f, &name, &name_type, &addr)) {
+		if (addr.ss_family != AF_INET) {
+			continue;
+		}
+		if (name_type != qname_type) {
+			continue;
+		}
+		if (memcmp(&((const struct sockaddr_in *)paddr)->sin_addr,
+			   &((const struct sockaddr_in *)&addr)->sin_addr,
+			   sizeof(struct in_addr)) == 0) {
+			fstrcpy(pname, name);
+			endlmhosts(f);
+			return true;
+		}
+	}
+	endlmhosts(f);
+	return false;
+}
+
 /****************************************************************************
  Find the first type XX name in a node status reply - used for finding
  a servers name given its IP. Return the matched name in *name.
@@ -957,6 +993,13 @@ bool name_status_find(const char *q_name,
 		return false;
 	}
 
+	result = name_status_lmhosts(to_ss, type, name);
+	if (result) {
+		DBG_DEBUG("Found name %s in lmhosts\n", name);
+		namecache_status_store(q_name, q_type, type, to_ss, name);
+		return true;
+	}
+
 	set_socket_addr_v4(&ss);
 
 	/* W2K PDC's seem not to respond to '*'#0. JRA */
-- 
2.1.4