dnsmasq: Update to 2.70.

[people/teissler/ipfire-2.x.git] / src / patches / dnsmasq-2.70-Add-support-to-read-ISC-DHCP-lease-file.patch

From b3c0d11d8bcf810b8f50f695ea36c8183fa4791a Mon Sep 17 00:00:00 2001
From: Michael Tremer <michael.tremer@ipfire.org>
Date: Mon, 28 Apr 2014 00:51:13 +0200
Subject: [PATCH] Add support to read ISC DHCP lease file.

---
 Makefile      |   2 +-
 src/cache.c   |  13 +++-
 src/dnsmasq.c |   5 ++
 src/dnsmasq.h |   5 ++
 src/isc.c     | 234 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/option.c  |   2 +-
 6 files changed, 256 insertions(+), 5 deletions(-)
 create mode 100644 src/isc.c

diff --git a/Makefile b/Makefile
index 292c8bd..5e0cdbe 100644
--- a/Makefile
+++ b/Makefile
@@ -69,7 +69,7 @@ objs = cache.o rfc1035.o util.o option.o forward.o network.o \
        dnsmasq.o dhcp.o lease.o rfc2131.o netlink.o dbus.o bpf.o \
        helper.o tftp.o log.o conntrack.o dhcp6.o rfc3315.o \
        dhcp-common.o outpacket.o radv.o slaac.o auth.o ipset.o \
-       domain.o dnssec.o blockdata.o
+       domain.o dnssec.o blockdata.o isc.o
 
 hdrs = dnsmasq.h config.h dhcp-protocol.h dhcp6-protocol.h \
        dns-protocol.h radv-protocol.h ip6addr.h
diff --git a/src/cache.c b/src/cache.c
index 5cec918..1f5657f 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -17,7 +17,7 @@
 #include "dnsmasq.h"
 
 static struct crec *cache_head = NULL, *cache_tail = NULL, **hash_table = NULL;
-#ifdef HAVE_DHCP
+#if (defined HAVE_DHCP) || (defined HAVE_ISC_READER)
 static struct crec *dhcp_spare = NULL;
 #endif
 static struct crec *new_chain = NULL;
@@ -222,6 +222,9 @@ static void cache_free(struct crec *crecp)
       crecp->flags &= ~F_BIGNAME;
     }
 
+  if (crecp->flags & F_DHCP)
+    free(crecp->name.namep);
+
 #ifdef HAVE_DNSSEC
   cache_blockdata_free(crecp);
 #endif
@@ -1110,7 +1113,7 @@ void cache_reload(void)
       total_size = read_hostsfile(ah->fname, ah->index, total_size, (struct crec **)daemon->packet, revhashsz);
 } 
 
-#ifdef HAVE_DHCP
+#if (defined HAVE_DHCP) || (defined HAVE_ISC_READER)
 struct in_addr a_record_from_hosts(char *name, time_t now)
 {
   struct crec *crecp = NULL;
@@ -1188,7 +1191,7 @@ void cache_add_dhcp_entry(char *host_name, int prot,
       addrlen = sizeof(struct in6_addr);
     }
 #endif
-  
+
   inet_ntop(prot, host_address, daemon->addrbuff, ADDRSTRLEN);
   
   while ((crec = cache_find_by_name(crec, host_name, 0, flags | F_CNAME)))
@@ -1253,7 +1256,11 @@ void cache_add_dhcp_entry(char *host_name, int prot,
       else
 	crec->ttd = ttd;
       crec->addr.addr = *host_address;
+#ifdef HAVE_ISC_READER
+      crec->name.namep = strdup(host_name);
+#else
       crec->name.namep = host_name;
+#endif
       crec->uid = next_uid();
       cache_hash(crec);
 
diff --git a/src/dnsmasq.c b/src/dnsmasq.c
index 1c96a0e..156ac9a 100644
--- a/src/dnsmasq.c
+++ b/src/dnsmasq.c
@@ -934,6 +934,11 @@ int main (int argc, char **argv)
 
 	  poll_resolv(0, daemon->last_resolv != 0, now); 	  
 	  daemon->last_resolv = now;
+
+#ifdef HAVE_ISC_READER
+	  if (daemon->lease_file && !daemon->dhcp)
+	    load_dhcp(now);
+#endif
 	}
       
       if (FD_ISSET(piperead, &rset))
diff --git a/src/dnsmasq.h b/src/dnsmasq.h
index 3032546..a40b2a9 100644
--- a/src/dnsmasq.h
+++ b/src/dnsmasq.h
@@ -1447,3 +1447,8 @@ void slaac_add_addrs(struct dhcp_lease *lease, time_t now, int force);
 time_t periodic_slaac(time_t now, struct dhcp_lease *leases);
 void slaac_ping_reply(struct in6_addr *sender, unsigned char *packet, char *interface, struct dhcp_lease *leases);
 #endif
+
+/* isc.c */
+#ifdef HAVE_ISC_READER
+void load_dhcp(time_t now);
+#endif
diff --git a/src/isc.c b/src/isc.c
new file mode 100644
index 0000000..565e4e2
--- /dev/null
+++ b/src/isc.c
@@ -0,0 +1,234 @@
+/* dnsmasq is Copyright (c) 2014 John Volpe, Simon Kelley and
+     Michael Tremer
+
+  This program is free software; you can redistribute it and/or modify
+  it under the terms of the GNU General Public License as published by
+  the Free Software Foundation; version 2 dated June, 1991, or
+  (at your option) version 3 dated 29 June, 2007.
+
+  This program is distributed in the hope that it will be useful,
+  but WITHOUT ANY WARRANTY; without even the implied warranty of
+  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  GNU General Public License for more details.
+  
+  You should have received a copy of the GNU General Public License
+  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+  Code in this file is based on contributions by John Volpe and
+  Simon Kelley. Updated for recent versions of dnsmasq by
+  Michael Tremer.
+*/
+
+#include "dnsmasq.h"
+
+#ifdef HAVE_ISC_READER
+#define MAXTOK 50
+
+struct isc_dhcp_lease {
+	char* name;
+	char* fqdn;
+	time_t expires;
+	struct in_addr addr;
+	struct isc_dhcp_lease* next;
+};
+
+static struct isc_dhcp_lease* dhcp_lease_new() {
+	struct isc_dhcp_lease* lease = whine_malloc(sizeof(*lease));
+
+	lease->name = NULL;
+	lease->fqdn = NULL;
+	lease->next = NULL;
+
+	return lease;
+}
+
+static void dhcp_lease_free(struct isc_dhcp_lease* lease) {
+	if (!lease)
+		return;
+
+	if (lease->name)
+		free(lease->name);
+	if (lease->fqdn)
+		free(lease->fqdn);
+	free(lease);
+}
+
+static int next_token(char* token, int buffsize, FILE* fp) {
+	int c, count = 0;
+	char* cp = token;
+
+	while ((c = getc(fp)) != EOF) {
+		if (c == '#') {
+			do {
+				c = getc(fp);
+			} while (c != '\n' && c != EOF);
+		}
+
+		if (c == ' ' || c == '\t' || c == '\n' || c == ';') {
+			if (count)
+				break;
+		} else if ((c != '"') && (count < buffsize - 1)) {
+			*cp++ = c;
+			count++;
+		}
+	}
+
+	*cp = 0;
+	return count ? 1 : 0;
+}
+
+static time_t parse_lease_time(const char* token_date, const char* token_time) {
+	time_t time = (time_t)(-1);
+	struct tm lease_time;
+
+	static const int months[11] = {31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334};
+
+	if (sscanf(token_date, "%d/%d/%d", &lease_time.tm_year, &lease_time.tm_mon, &lease_time.tm_mday) == 3) {
+		if (sscanf(token_time, "%d:%d:%d", &lease_time.tm_hour, &lease_time.tm_min, &lease_time.tm_sec) == 3) {
+			/* There doesn't seem to be a universally available library function
+			   which converts broken-down _GMT_ time to seconds-in-epoch.
+			   The following was borrowed from ISC dhcpd sources, where
+			   it is noted that it might not be entirely accurate for odd seconds.
+			   Since we're trying to get the same answer as dhcpd, that's just
+			   fine here. */
+			time = ((((((365 * (lease_time.tm_year - 1970) +
+				(lease_time.tm_year - 1969) / 4 +
+				(lease_time.tm_mon > 1 ? months[lease_time.tm_mon - 2] : 0) +
+				(lease_time.tm_mon > 2 && !((lease_time.tm_year - 1972) & 3 )) +
+				(lease_time.tm_mday - 1)) * 24) +
+				 lease_time.tm_hour) * 60) +
+				 lease_time.tm_mon) * 60) +
+				 lease_time.tm_sec;
+		}
+	}
+
+	return time;
+}
+
+static off_t lease_file_size = (off_t)0;
+static ino_t lease_file_inode = (ino_t)0;
+
+void load_dhcp(time_t now) {
+	struct isc_dhcp_lease* leases = NULL;
+
+	struct stat statbuf;
+	if (stat(daemon->lease_file, &statbuf) == -1) {
+		return;
+	}
+
+	/* Do nothing if the lease file has not changed. */
+	if ((statbuf.st_size <= lease_file_size) && (statbuf.st_ino == lease_file_inode))
+		return;
+
+	lease_file_size = statbuf.st_size;
+	lease_file_inode = statbuf.st_ino;
+
+	FILE* fp = fopen(daemon->lease_file, "r");
+	if (!fp) {
+		my_syslog(LOG_ERR, _("failed to load %s:%s"), daemon->lease_file, strerror(errno));
+		return;
+	}
+
+	my_syslog(LOG_INFO, _("reading %s"), daemon->lease_file);
+
+	char* hostname = daemon->namebuff;
+	struct in_addr host_address;
+	time_t time_starts = -1;
+	time_t time_ends = -1;
+	int nomem;
+
+	char token[MAXTOK];
+	while ((next_token(token, MAXTOK, fp))) {
+		if (strcmp(token, "lease") == 0) {
+			hostname[0] = '\0';
+
+			if (next_token(token, MAXTOK, fp) && ((host_address.s_addr = inet_addr(token)) != (in_addr_t)-1)) {
+				if (next_token(token, MAXTOK, fp) && *token == '{') {
+					while (next_token(token, MAXTOK, fp) && *token != '}') {
+						if ((strcmp(token, "client-hostname") == 0) || (strcmp(token, "hostname") == 0)) {
+							if (next_token(hostname, MAXDNAME, fp)) {
+								if (!canonicalise(hostname, &nomem)) {
+									*hostname = 0;
+									my_syslog(LOG_ERR, _("bad name in %s"), daemon->lease_file);
+								}
+							}
+						} else if ((strcmp(token, "starts") == 0) || (strcmp(token, "ends") == 0)) {
+							char token_date[MAXTOK];
+							char token_time[MAXTOK];
+
+							int is_starts = strcmp(token, "starts") == 0;
+
+							// Throw away the weekday and parse the date.
+							if (next_token(token, MAXTOK, fp) && next_token(token_date, MAXTOK, fp) && next_token(token_time, MAXTOK, fp)) {
+								time_t time = parse_lease_time(token_date, token_time);
+
+								if (is_starts)
+									time_starts = time;
+								else
+									time_ends = time;
+							}
+						}
+					}
+
+					if (!*hostname)
+						continue;
+
+					if ((time_starts == -1) || (time_ends == -1))
+						continue;
+
+					if (difftime(now, time_ends) > 0)
+						continue;
+
+					char* dot = strchr(hostname, '.');
+					if (dot) {
+						if (!daemon->domain_suffix || hostname_isequal(dot + 1, daemon->domain_suffix)) {
+							my_syslog(LOG_WARNING,
+								_("Ignoring DHCP lease for %s because it has an illegal domain part"),
+								hostname);
+							continue;
+						}
+						*dot = 0;
+					}
+
+					struct isc_dhcp_lease* lease = dhcp_lease_new();
+					lease->name = strdup(hostname);
+					lease->addr = host_address;
+					lease->expires = time_ends;
+					lease->next = NULL;
+
+					if (daemon->domain_suffix) {
+						asprintf(&lease->fqdn, "%s.%s", hostname, daemon->domain_suffix);
+					}
+
+					if (!leases)
+						leases = lease;
+					else
+						leases->next = lease;
+				}
+			}
+		}
+	}
+
+	fclose(fp);
+
+	// Drop all entries.
+	cache_unhash_dhcp();
+
+	while (leases) {
+		struct isc_dhcp_lease *lease = leases;
+		leases = lease->next;
+
+		if (lease->fqdn) {
+			cache_add_dhcp_entry(lease->fqdn, AF_INET, (struct all_addr*)&lease->addr.s_addr, lease->expires);
+		}
+
+		if (lease->name) {
+			cache_add_dhcp_entry(lease->name, AF_INET, (struct all_addr*)&lease->addr.s_addr, lease->expires);
+		}
+
+		// Cleanup
+		dhcp_lease_free(lease);
+	}
+}
+
+#endif
diff --git a/src/option.c b/src/option.c
index daa728f..d16c982 100644
--- a/src/option.c
+++ b/src/option.c
@@ -1642,7 +1642,7 @@ static int one_opt(int option, char *arg, char *errstr, char *gen_err, int comma
 	ret_err(_("bad MX target"));
       break;
 
-#ifdef HAVE_DHCP      
+#if (defined HAVE_DHCP) || (defined HAVE_ISC_READER)
     case 'l':  /* --dhcp-leasefile */
       daemon->lease_file = opt_string_alloc(arg);
       break;
-- 
1.9.0