From: Ted Lemon <source@isc.org>
Date: Thu, 1 Jul 1999 20:17:20 +0000 (+0000)
Subject: Name service update routines, from Irina Goble, by way of Brian Murrell
X-Git-Tag: V3-BETA-1-PATCH-0~27
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=46e5d066c467637133d8aacec4a6ac7a41e6162b;p=thirdparty%2Fdhcp.git

Name service update routines, from Irina Goble, by way of Brian Murrell
---

diff --git a/common/nsupdate.c b/common/nsupdate.c
new file mode 100644
index 000000000..64c1e193d
--- /dev/null
+++ b/common/nsupdate.c
@@ -0,0 +1,381 @@
+/* nsupdate.c
+
+   Tables of information... */
+
+/*
+ * Copyright (c) 1999 Internet Software Consortium.
+ * Use is subject to license terms which appear in the file named
+ * ISC-LICENSE that should have accompanied this file when you
+ * received it.   If a file named ISC-LICENSE did not accompany this
+ * file, or you are not sure the one you have is correct, you may
+ * obtain an applicable copy of the license at:
+ *
+ *             http://www.isc.org/isc-license-1.0.html. 
+ *
+ * This file is part of the ISC DHCP distribution.   The documentation
+ * associated with this file is listed in the file DOCUMENTATION,
+ * included in the top-level directory of this release.
+ *
+ * Support and other services are available for ISC products - see
+ * http://www.isc.org for more information.
+ *
+ * Note: file is currently based on work done by Brian Murrell, Irina
+ * Goble and others.   The copyright message is not final.
+ */
+
+#ifndef lint
+static char copyright[] =
+"$Id: nsupdate.c,v 1.1 1999/07/01 20:17:20 mellon Exp $ Copyright (c) 1999 The Internet Software Consortium.  All rights reserved.\n";
+#endif /* not lint */
+
+#include "dhcpd.h"
+
+#if defined (NSUPDATE)
+/* Yet another new plan.
+   First thing to be done is to determine if a change actually needs to be
+   done.  This can be done by figuring out the hostname.domain and revname
+   and then comparing them to the lease->ddns* values.  Only make the changes
+   necessary which can be any combination and number of remove A, add A,
+   remove PTR, add PTR */
+
+/* Return the forward name of a lease. */
+char *ddns_rev_name(lease, state, packet)
+	struct lease *lease;
+	struct lease_state *state;
+	struct packet *packet;
+{
+	struct option_cache *oc = NULL;
+	struct data_string d;
+	static char revname[MAXDNAME];
+	char	revdomain[MAXDNAME];
+
+	revname[0]='\0';
+	revdomain[0]='\0';
+
+	/* Figure out what reverse domain to update
+	   First take the scoped "ddns-rev-domainname" option if present
+	   then assume d.c.b.a.in-addr.arpa. if not present
+	   error if neither are present */
+	oc = lookup_option (&server_universe, state -> options,
+			    SV_DDNS_REV_DOMAIN_NAME);
+	memset (&d, 0, sizeof d);
+	if (oc && evaluate_option_cache (&d, packet, packet -> options, oc)) {
+		memcpy(revdomain, d.data, d.len);
+		revdomain[d.len]='\0';
+		data_string_forget (&d, "nsupdate");
+	} else
+		strcpy(revdomain, "in-addr.arpa");
+	if ( lease->ip_addr.len != 4 ) { /* IPv4 */
+		log_error("unsupported IP address length: %d",
+			  lease->ip_addr.len);
+		return NULL;
+	}
+	snprintf(revname, MAXDNAME, "%d.%d.%d.%d.%s.",
+		 lease->ip_addr.iabuf[3], lease->ip_addr.iabuf[2],
+		 lease->ip_addr.iabuf[1], lease->ip_addr.iabuf[0], revdomain);
+
+	return revname;
+}
+
+/* Return the forward name of a lease. */
+char *ddns_fwd_name(lease, state, packet)
+	struct lease *lease;
+	struct lease_state *state;
+	struct packet *packet;
+{
+	struct option_cache *oc = NULL;
+	struct data_string d;
+	static char hostname[MAXDNAME];
+	char	domain[MAXDNAME];
+
+	domain[0]='\0';
+	hostname[0]='\0';
+
+	/* Figure out the domain name of a lease.
+	   First take the scoped "ddns-domainname" option if present
+	   then the dhcp option "domain-name" if present
+	   error if neither are present */
+	oc = lookup_option (&server_universe, state -> options,
+			    SV_DDNS_DOMAIN_NAME);
+	memset (&d, 0, sizeof d);
+	if (oc && evaluate_option_cache (&d, packet, packet -> options, oc)) {
+		memcpy(domain, d.data, d.len);
+		domain[d.len]='\0';
+		data_string_forget (&d, "nsupdate");
+	} else {
+		oc = lookup_option (&dhcp_universe, state -> options,
+				    DHO_DOMAIN_NAME);
+		memset (&d, 0, sizeof d);
+		if (oc && evaluate_option_cache (&d, packet, packet -> options,
+						 oc)) {
+			memcpy(domain, d.data, d.len);
+			domain[d.len]='\0';
+			data_string_forget (&d, "nsupdate");
+		} else {
+			log_info("nsupdate failed: %s",
+				 "unknown domain for update");
+			return NULL;
+		}
+	}
+
+	/* Figure out what host in the domain to assign to.
+	   First take the scoped "ddns-hostname" option
+	   then the dhcp option "host-name" if present
+	   then the dhcp host_decl "name" if present
+	   error if neither are present. */
+	oc = lookup_option (&server_universe, state -> options,
+			    SV_DDNS_HOST_NAME);
+	memset (&d, 0, sizeof d);
+	if (oc && evaluate_option_cache (&d, packet, packet -> options, oc)) {
+		memcpy(hostname, d.data, d.len);
+		hostname[d.len]='\0';
+		data_string_forget (&d, "nsupdate");
+	} else {
+		oc = lookup_option (&dhcp_universe,
+			      state -> options, DHO_HOST_NAME);
+		memset (&d, 0, sizeof d);
+		if (oc && evaluate_option_cache (&d, packet, packet -> options,
+						 oc)) {
+			memcpy(hostname, d.data, d.len);
+			hostname[d.len]='\0';
+			data_string_forget (&d, "nsupdate");
+		} else {
+			if (lease -> host && lease -> host -> name &&
+			    strcmp(lease -> host -> name, "")!=0)
+				strcpy(hostname, lease -> host -> name);
+			else {
+				log_info("nsupdate failed: %s",
+					 "unknown hostname for update");
+				return NULL;
+			}
+		}
+	}
+	if ( !res_hnok(hostname) ) {
+		log_error("nsupdate: Bad hostname \"%s\"", hostname);
+		return NULL;
+	}
+
+	if (snprintf(hostname, MAXDNAME, "%s.%s.", hostname, domain) < 0) {
+		log_error("nsupdate: Build FQDN failed");
+		return NULL;
+	}
+
+	return hostname;
+}
+
+int nsupdateA(hostname, ip_addr, ttl, opcode)
+	char *hostname;
+	char *ip_addr;
+	u_int32_t ttl;
+	int	opcode;
+{
+	int 	z;
+	ns_updrec	*u, *n;
+
+	switch (opcode) {
+	case ADD:
+		if (!(u = res_mkupdrec(S_PREREQ, hostname, C_IN, T_A, 0))) 
+			return 0;
+		u->r_opcode = NXRRSET; u->r_data = NULL; u->r_size = 0;
+		if (!(n = res_mkupdrec(S_UPDATE, hostname, C_IN, T_A, ttl))) {
+			res_freeupdrec(u);
+			return 0;
+		}
+		n->r_opcode = opcode;
+		n->r_data = ip_addr;
+		n->r_size = strlen(n->r_data);
+		u->r_next = n;
+		z = res_update(u);
+		log_info("add %s: %s %d IN A %s",
+			 z == 1 ? "succeeded" : "failed", hostname, ttl,
+			 n->r_data);
+		res_freeupdrec(u); 
+		res_freeupdrec(n);
+		if (z != 1) 
+			return;
+		/* delete all PTR RRs with the same ip address. Wow! */
+		if (!(u = res_mkupdrec(S_UPDATE, revname, C_IN, T_PTR, 0)))
+			return;
+		u->r_opcode = DELETE; u->r_data = NULL; u->r_size = 0;
+		log_info("cleaning all PTR RRs for %s", revname);
+		res_update(u);
+		res_freeupdrec(u);
+		break;
+	case	DELETE:
+		ttl = 0;
+		if (!(u = res_mkupdrec(S_UPDATE, hostname, C_IN, T_A, ttl)))
+			return 0;
+		u->r_opcode = opcode;
+		u->r_data = ip_addr;
+		u->r_size = strlen(u->r_data);
+		z = res_update(u);
+		log_info("delete %s: %s %d IN A %s",
+			 z == 1 ? "succeeded" : "failed",
+			 hostname, ttl, u->r_data);
+		res_freeupdrec(u);
+		break;
+	}
+	return z;
+}
+
+int nsupdatePTR(hostname, revname, ttl, opcode)
+	char *hostname;
+	char *revname;
+	u_int32_t ttl;
+	int	opcode;
+{
+	int 	z;
+	ns_updrec	*u;
+
+	if (opcode == DELETE)
+		ttl = 0;
+	if (!(u = res_mkupdrec(S_UPDATE, revname, C_IN, T_PTR, ttl)))
+		return 0;
+	u->r_opcode = opcode;
+	u->r_data = hostname;
+	u->r_size = strlen(u->r_data);
+	z = res_update(u);
+	log_info("%s %s: %s %d IN PTR %s", 
+		 opcode == ADD ? "add" : 
+				 "delete", z == 1 ? "succeeded" : "failed",
+		 revname, ttl, hostname);
+	res_freeupdrec(u);
+	return z;
+}
+
+void nsupdate(lease, state, packet, opcode)
+	struct lease *lease;
+	struct lease_state *state;
+	struct packet *packet;
+	int	opcode;
+{
+	char	*hostname, *revname;
+	u_int32_t	ttl = 0;
+
+	if (!(opcode == ADD || opcode == DELETE))
+		return;
+
+	if (!packet){
+		log_info("invalid pointer at %s:%d",
+			 __FILE__, __LINE__-2);
+		return;
+	}
+	if (!packet -> options) {
+		log_info("invalid pointer at %s:%d",
+			 __FILE__, __LINE__-2);
+		return;
+	}
+	if (!lease){
+		log_info("invalid pointer at %s:%d",
+			 __FILE__, __LINE__-2);
+		return;
+	}
+	
+	switch (opcode) {
+	case ADD:
+		if (!state) {
+			log_info("invalid pointer at %s:%d",
+				 __FILE__, __LINE__-2);
+			return;
+		}
+		if (!state -> options) {
+			log_info("invalid pointer at %s:%d",
+				 __FILE__, __LINE__-2);
+			return;
+		}
+
+		hostname = ddns_fwd_name(lease, state, packet);
+		if (!hostname)	/* there is nothing we can do now */
+			return;
+		revname = ddns_rev_name(lease, state, packet);
+		
+		if (state -> offered_expiry > lease -> timestamp)
+			ttl = state -> offered_expiry -
+			lease->timestamp;
+		else
+			log_error("nsupdate: ttl < 0");
+
+		/* delete an existing A if the one to be added is different */
+		if (lease -> ddns_fwd_name &&
+		    strcmp(hostname, lease -> ddns_fwd_name)) {
+			int y;
+			y=nsupdateA(lease -> ddns_fwd_name,
+				    piaddr(lease->ip_addr), ttl, DELETE);
+
+			/* delete an existing PTR if new one is different */
+			if (lease -> ddns_rev_name &&
+			    (strcmp(hostname, lease -> ddns_fwd_name) ||
+			     strcmp(revname, lease -> ddns_rev_name)) &&
+			    nsupdatePTR(lease -> ddns_fwd_name, revname,
+					      ttl, DELETE)) {
+				/* clear the forward DNS name pointer */
+				if (lease -> ddns_rev_name)
+					dfree(lease -> ddns_rev_name,
+					      "nsupdate");
+				lease -> ddns_rev_name = 0;
+			}
+			if (y) {
+				/* clear the forward DNS name pointer */
+				if (lease -> ddns_fwd_name)
+					dfree(lease -> ddns_fwd_name,
+					      "nsupdate");
+				lease -> ddns_fwd_name = 0;
+			}
+		}
+		/* only update if there is no A record there already */
+		if (!lease -> ddns_fwd_name) {
+			int z;
+		    	z=nsupdateA(hostname, piaddr(lease->ip_addr), ttl, ADD);
+			if (z < 1)
+				return;
+
+			/* remember this in the lease structure for release */
+			lease -> ddns_fwd_name = dmalloc(strlen(hostname) + 1,
+						 	 "nsupdate");
+			strcpy (lease -> ddns_fwd_name, hostname);
+		}
+
+		if (!revname)	/* there is nothing more we can do now */
+			return;
+
+		if (!lease -> ddns_rev_name) {
+			/* add a PTR RR */
+			if (nsupdatePTR(hostname, revname, ttl, ADD)) {
+				/* remember in the lease struct for a release */
+				lease -> ddns_rev_name =
+				       dmalloc(strlen(revname) + 1, "nsupdate");
+				strcpy (lease -> ddns_rev_name, revname);
+			}
+		}
+		break;
+	case DELETE:
+		ttl = 0;
+		if (lease -> ddns_fwd_name) {
+			int y;
+			y = nsupdateA(lease -> ddns_fwd_name,
+				      piaddr(lease->ip_addr), ttl, DELETE);
+
+			if (lease -> ddns_rev_name &&
+			    nsupdatePTR(lease -> ddns_fwd_name,
+					lease -> ddns_rev_name, ttl, opcode)) {
+				/* clear the reverse DNS name pointer */
+				if (lease -> ddns_rev_name)
+					dfree(lease -> ddns_rev_name,
+					      "nsupdate");
+				lease -> ddns_rev_name = 0;
+			}
+
+			if (y) {
+				/* clear the forward DNS name pointer */
+				if (lease -> ddns_fwd_name)
+					dfree(lease -> ddns_fwd_name,
+					      "nsupdate");
+				lease -> ddns_fwd_name = 0;
+			}
+		}
+		break;
+	}
+	
+	return;
+}
+#endif /* defined (NSUPDATE) */