import of dnsmasq-2.34.tar.gz

CHANGELOG

@@ -1935,3 +1935,80 @@ version 2.33
 	    Add contrib/wrt/dhcp_release.c which is a small utility 
 	    which removes DHCP leases using DHCPRELEASE operation in
 	    the DHCP protocol.
+
+version 2.34
+	    Tweak network-determination code for another corner case:
+	    in this case a host forced to move between dhcp-ranges on
+	    the same physical interface. Thanks to Matthias Andree.
+	    
+	    Improve handling of high DNS loads by throttling acceptance of
+	    new queries when resources are tight. This should be a
+	    better response than the "forwarding table full..."
+	    message which was logged before.
+
+	    Fixed intermittent infinite loop when re-reading
+	    /etc/ethers after SIGHUP. Thanks to Eldon Ziegler for the
+	    bug report.
+
+	    Provide extra information to the lease-change script: when
+	    a lease loses its hostname (because a new lease comes
+	    along and claims the same new), the "old" action is called 
+	    with the current state of the lease, ie no name. The
+	    change is to provide the former name which the lease had
+	    in the environment variable DNSMASQ_OLD_HOSTNAME. This
+	    helps scripts which do stuff based on hostname, rather
+	    than IP address. Also provide vendor-class and user-class
+	    information to the lease-change script when a new lease is
+	    created in the DNSMASQ_VENDOR_CLASS and
+	    DNSMASQ_USER_CLASS<n> environment variables. Suggestion 
+            from Francois-Xavier Le Bail.
+
+	    Run the lease change script as root, even when dnsmasq is
+	    configured to change UID to an unprivileged user. Since
+	    most uses of the lease change script need root, this
+	    allows its use whilst keeping the security advantages of
+	    running the daemon without privs. The script is invoked
+	    via a small helper process which keeps root UID, and
+	    validates all data received from the main process. To get
+	    root, an attacker would have to break dnsmasq and then
+	    break the helper through the restricted comms channel 
+	    linking the two.
+	    
+	    Add contrib/port-forward/* which is a script to set up 
+	    port-forwards using the DHCP lease-change script. It's
+	    possible to add a host to a config file by name, and when
+	    that host gets a DHCP lease, the script will use iptables
+	    to set up port-forwards to configured ports at the address
+	    which the host is allocated. The script also handles
+	    setting up the port-forward iptables entries after reboot,
+	    using the persistent lease database, and removing them
+	    when a host leaves and its DHCP lease expires.
+
+	    Fix unaligned access problem which caused wrong log
+	    messages with some clients on some architectures. Thanks
+	    to Francois-Xavier Le Bail for the bugreport.
+
+	    Fixed problem with DHCPRELEASE and multi-address
+	    interfaces. Enhanced contrib/wrt/dhcp_release to cope
+	    under these circumstances too. Thanks to Eldon Ziegler for
+	    input on this.
+
+	    Updated French translation: thanks to Gildas Le Nadan.
+
+	    Upgraded the name hash function in the DNS cache. Thanks
+	    to Oleg Khovayko for good work on this.
+
+	    Added --clear-on-reload flag.  Suggestion from Johannes
+	    Stezenbach.
+
+	    Treat a nameserver address of 0.0.0.0 as "nothing". Erwin 
+            Cabrera spotted that specifying a nameserver as 0.0.0.0 
+	    breaks things badly; this is because the network stack
+	    treats is as "this host" and an endless loop ensues.
+		   
+            Added Webmin module in contrib/webmin. Thanks to Neil
+            Fisher for that.
+
+
+
+ 

bld/Makefile

@@ -3,7 +3,7 @@ PKG_CONFIG ?= pkg-config
 
 
 OBJS = cache.o rfc1035.o util.o option.o forward.o isc.o network.o \
-       dnsmasq.o dhcp.o lease.o rfc2131.o netlink.o dbus.o bpf.o
+       dnsmasq.o dhcp.o lease.o rfc2131.o netlink.o dbus.o bpf.o helper.o
 
 .c.o:
 	$(CC) $(CFLAGS) $(COPTS) $(I18N) `echo $(COPTS) | ../bld/pkg-wrapper $(PKG_CONFIG) --cflags dbus-1` $(RPM_OPT_FLAGS) -Wall -W -c $<

contrib/port-forward/dnsmasq-portforward

@@ -0,0 +1,68 @@
+#!/bin/bash
+# 
+# /usr/sbin/dnsmasq-portforward
+#
+# A script which gets run when the dnsmasq DHCP lease database changes.
+# It logs to $LOGFILE, if it exists, and maintains port-forwards using
+# IP-tables so that they always point to the correct host. See
+# $PORTSFILE for details on configuring this. dnsmasq must be version 2.34 
+# or later.
+#
+# To enable this script, add 
+#    dhcp-script=/usr/sbin/dnsmasq-portforward
+# to /etc/dnsmasq.conf
+#
+# To enable logging, touch $LOGFILE
+#
+
+PORTSFILE=/etc/portforward
+LOGFILE=/var/log/dhcp.log
+IPTABLES=/sbin/iptables
+
+action=${1:-0}
+hostname=${4}
+
+# log what's going on.
+if [ -f ${LOGFILE} ] ; then
+    date +"%D %T $*" >>${LOGFILE}
+fi
+
+# If a lease gets stripped of a name, we see that as an "old" action
+# with DNSMASQ_OLD_HOSTNAME set, convert it into a "del" 
+if [ ${DNSMASQ_OLD_HOSTNAME} ] && [ ${action} = old ] ; then
+    action=del
+    hostname=${DNSMASQ_OLD_HOSTNAME}
+fi
+
+# action init is not relevant, and will only be seen when leasefile-ro is set.
+if [ ${action} = init ] ; then
+    exit 0
+fi
+
+if [ ${hostname} ]; then
+    ports=$(sed -n -e "/^${hostname}\ .*/ s/^.* //p" ${PORTSFILE})
+
+    for port in $ports; do
+	verb=removed
+	protocol=tcp
+	if [ ${port:0:1} = u ] ; then
+	    protocol=udp 
+	    port=${port/u/}
+	fi
+	src=${port/:*/}
+	dst=${port/*:/}
+# delete first, to avoid multiple copies of rules.
+	${IPTABLES} -t nat -D PREROUTING -p $protocol --destination-port $src -j DNAT --to-destination ${3}:$dst
+        if [ ${action} != del ] ; then
+	    ${IPTABLES} -t nat -A PREROUTING -p $protocol --destination-port $src -j DNAT --to-destination ${3}:$dst
+	    verb=added
+	fi
+	if [ -f ${LOGFILE} ] ; then
+	    echo "     DNAT $protocol $src to ${3}:$dst ${verb}." >>${LOGFILE}
+	fi
+    done
+fi
+    
+exit 0
+
+

contrib/port-forward/portforward

@@ -0,0 +1,28 @@
+# This file is read by /usr/sbin/dnsmasq-portforward and used to set up port 
+# forwarding to hostnames. If the dnsmasq-determined hostname matches the
+# first column of this file, then a DNAT port-forward will be set up 
+# to the address which has just been allocated by DHCP . The second field 
+# is port number(s). If there is only one, then the port-forward goes to 
+# the same port on the DHCP-client, if there are two seperated with a 
+# colon, then the second number is the port to which the connection 
+# is forwarded on the DHCP-client. By default, forwarding is set up 
+# for TCP, but it can done for UDP instead by prefixing the port to "u". 
+# To forward both TCP and UDP, two lines are required. 
+#
+# eg.
+# wwwserver 80
+# will set up a port forward from port 80 on this host to port 80 
+# at the address allocated to wwwserver whenever wwwserver gets a DHCP lease.
+#
+# wwwserver 8080:80
+# will set up a port forward from port 8080 on this host to port 80
+# on the DHCP-client.
+#
+# dnsserver 53
+# dnsserver u53
+# will port forward port 53 UDP and TCP from this host to port 53 on dnsserver.
+#
+# Port forwards will recreated when dnsmasq restarts after a reboot, and
+# removed when DHCP leases expire. After editing this file, restart dnsmasq 
+# to install new iptables entries in the kernel.
+

contrib/webmin/README

@@ -0,0 +1,54 @@
+
+This is the README for the DNSmasq webmin module.
+
+Problems:
+
+1) There's only basic error checking - if you enter some bad
+addresses or names, they will go straight into the config file
+although we do check for things like IP addresses being of
+the correct form (no letters, 4 groups of up to 3 digits
+separated by dots etc). One thing that ISN'T CHECKED FOR is
+that IP dotted quads are all numbers < 256. Another is that
+netmasks are logical (you could enter a netmask of 255.0.255.0 
+for example). Essentially, if it'll pass the config file
+regex scanner (and the above examples will), it won't be 
+flagged as "bad" even if it is a big no-no for dnsmasq itself. 
+
+2) Code is ugly and a kludge - I ain't a programmer! There are probably 
+a lot of things that could be done to tidy up the code - eg, 
+it probably wouldn't hurt to move some common stuff into the lib file.
+
+3) I've used the %text hash and written an english lang file, but
+I am mono-lingual so no other language support as yet.
+
+4) for reasons unknown to me, the icon does not appear properly
+on the servers page of webmin (at least it doesn't for me!)
+
+5) icons have been shamelessly stolen from the ipfilter module,
+specifically the up and down arrows.
+
+6) if you delete an item, the config file will contain
+an otherwise empty, but commented line. This means that if
+you add some new stuff, then delete it, the config file
+will have a number of lines at the end that are just comments.
+Therefore, the config file could possibly grow quite large.
+
+7) NO INCLUDE FILES!
+if you use an include file, it'll be flagged as an error. 
+OK if the include file line is commented out though.
+
+8) deprecated lines not supported (eg user and group) - they
+may produce an error! (user and group don't, but you can't change
+them)
+
+IOW, it works, it's just not very elegant and not very robust.
+
+Hope you find it useful though - I do, as I prevents me having to ever
+wade through the config file and man pages again.
+
+If you modify it, or add a language file, and you have a spare moment,
+please e-mail me - I won't be upset at all if you fix my poor coding!
+(rather the opposite - I'd be pleased someone found it usefull)
+
+Cheers,
+	Neil Fisher <neil@magnecor.com.au>

contrib/wrt/dhcp_release.c

@@ -44,6 +44,10 @@
 #include <stdlib.h>
 #include <net/if_arp.h>
 #include <sys/ioctl.h>
+#include <linux/types.h>
+#include <linux/netlink.h>
+#include <linux/rtnetlink.h>
+#include <errno.h>
 
 #define DHCP_CHADDR_MAX          16
 #define BOOTREQUEST              1
@@ -69,6 +73,72 @@ struct dhcp_packet {
   unsigned char options[308];
 };
 
+static struct iovec iov;
+
+static int expand_buf(struct iovec *iov, size_t size)
+{
+  void *new;
+
+  if (size <= iov->iov_len)
+    return 1;
+
+  if (!(new = malloc(size)))
+    {
+      errno = ENOMEM;
+      return 0;
+    }
+
+  if (iov->iov_base)
+    {
+      memcpy(new, iov->iov_base, iov->iov_len);
+      free(iov->iov_base);
+    }
+
+  iov->iov_base = new;
+  iov->iov_len = size;
+
+  return 1;
+}
+
+static ssize_t netlink_recv(int fd)
+{
+  struct msghdr msg;
+  ssize_t rc;
+
+  msg.msg_control = NULL;
+  msg.msg_controllen = 0;
+  msg.msg_name = NULL;
+  msg.msg_namelen = 0;
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 1;
+    
+  while (1)
+    {
+      msg.msg_flags = 0;
+      while ((rc = recvmsg(fd, &msg, MSG_PEEK)) == -1 && errno == EINTR);
+      
+      /* 2.2.x doesn't suport MSG_PEEK at all, returning EOPNOTSUPP, so we just grab a 
+         big buffer and pray in that case. */
+      if (rc == -1 && errno == EOPNOTSUPP)
+        {
+          if (!expand_buf(&iov, 2000))
+            return -1;
+          break;
+        }
+      
+      if (rc == -1 || !(msg.msg_flags & MSG_TRUNC))
+        break;
+            
+      if (!expand_buf(&iov, iov.iov_len + 100))
+        return -1;
+    }
+
+  /* finally, read it for real */
+  while ((rc = recvmsg(fd, &msg, 0)) == -1 && errno == EINTR);
+  
+  return rc;
+}
+
 static int parse_hex(char *in, unsigned char *out, int maxlen, int *mac_type)
 {
   int i = 0;
@@ -103,6 +173,78 @@ static int parse_hex(char *in, unsigned char *out, int maxlen, int *mac_type)
     return i;
 }
 
+static int is_same_net(struct in_addr a, struct in_addr b, struct in_addr mask)
+{
+  return (a.s_addr & mask.s_addr) == (b.s_addr & mask.s_addr);
+}
+
+static struct in_addr find_interface(struct in_addr client, int fd, int index)
+{
+  struct sockaddr_nl addr;
+  struct nlmsghdr *h;
+  ssize_t len;
+ 
+  struct {
+    struct nlmsghdr nlh;
+    struct rtgenmsg g; 
+  } req;
+
+  addr.nl_family = AF_NETLINK;
+  addr.nl_pad = 0;
+  addr.nl_groups = 0;
+  addr.nl_pid = 0; /* address to kernel */
+
+  req.nlh.nlmsg_len = sizeof(req);
+  req.nlh.nlmsg_type = RTM_GETADDR;
+  req.nlh.nlmsg_flags = NLM_F_ROOT | NLM_F_MATCH | NLM_F_REQUEST | NLM_F_ACK; 
+  req.nlh.nlmsg_pid = 0;
+  req.nlh.nlmsg_seq = 1;
+  req.g.rtgen_family = AF_INET; 
+
+  if (sendto(fd, (void *)&req, sizeof(req), 0, 
+	     (struct sockaddr *)&addr, sizeof(addr)) == -1)
+    {
+      perror("sendto failed");
+      exit(1);
+    }
+  
+  while (1)
+    {
+      if ((len = netlink_recv(fd)) == -1)
+	{
+	  perror("netlink");
+	  exit(1);
+	}
+
+      for (h = (struct nlmsghdr *)iov.iov_base; NLMSG_OK(h, (size_t)len); h = NLMSG_NEXT(h, len))
+	if (h->nlmsg_type == NLMSG_DONE)
+	  exit(0);
+	else if (h->nlmsg_type == RTM_NEWADDR)
+          {
+            struct ifaddrmsg *ifa = NLMSG_DATA(h);  
+            struct rtattr *rta;
+            unsigned int len1 = h->nlmsg_len - NLMSG_LENGTH(sizeof(*ifa));
+            
+            if (ifa->ifa_index == index && ifa->ifa_family == AF_INET)
+              {
+                struct in_addr netmask, addr;
+                
+                netmask.s_addr = htonl(0xffffffff << (32 - ifa->ifa_prefixlen));
+                addr.s_addr = 0;
+                
+                for (rta = IFA_RTA(ifa); RTA_OK(rta, len1); rta = RTA_NEXT(rta, len1))
+		  if (rta->rta_type == IFA_LOCAL)
+		    addr = *((struct in_addr *)(rta+1));
+		
+                if (addr.s_addr && is_same_net(addr, client, netmask))
+		  return addr;
+	      }
+	  }
+    }
+ 
+  exit(0);
+}
+
 int main(int argc, char **argv)
 { 
   struct in_addr server, lease;
@@ -112,6 +254,11 @@ int main(int argc, char **argv)
   struct sockaddr_in dest;
   struct ifreq ifr;
   int fd = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP);
+  int nl = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
+  struct iovec iov;
+ 
+  iov.iov_len = 200;
+  iov.iov_base = malloc(iov.iov_len);
 
   if (argc < 4 || argc > 5)
     { 
@@ -119,7 +266,7 @@ int main(int argc, char **argv)
       exit(1);
     }
 
-  if (fd == -1)
+  if (fd == -1 || nl == -1)
     {
       perror("cannot create socket");
       exit(1);
@@ -128,15 +275,15 @@ int main(int argc, char **argv)
   /* This voodoo fakes up a packet coming from the correct interface, which really matters for 
      a DHCP server */
   strcpy(ifr.ifr_name, argv[1]);
-  ifr.ifr_addr.sa_family = AF_INET;
+  if (setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) == -1)
-  if (ioctl(fd, SIOCGIFADDR, &ifr) == -1 || setsockopt(fd, SOL_SOCKET, SO_BINDTODEVICE, &ifr, sizeof(ifr)) == -1)
     {
       perror("cannot setup interface");
       exit(1);
     }
   
-  server = ((struct sockaddr_in *) &ifr.ifr_addr)->sin_addr;
+  
   lease.s_addr = inet_addr(argv[2]);
+  server = find_interface(lease, nl, if_nametoindex(argv[1]));
   
   memset(&packet, 0, sizeof(packet));
  
@@ -174,7 +321,7 @@ int main(int argc, char **argv)
   dest.sin_addr = server;
 
   if (sendto(fd, &packet, sizeof(packet), 0, 
-	     (struct sockaddr *)&dest, sizeof(dest)) == 1)
+	     (struct sockaddr *)&dest, sizeof(dest)) == -1)
     {
       perror("sendto failed");
       exit(1);

contrib/wrt/lease_update.sh

@@ -35,9 +35,6 @@ PREFIX=dnsmasq_lease_
 
 # Primary key is address.
 
-NVRAM=/usr/sbin/nvram
-PREFIX=dnsmasq_lease_
-
 if [ ${1} = init ] ; then
      ${NVRAM} show | sed -n -e "/^${PREFIX}.*/ s/^.*=//p"
 else

dnsmasq.conf.example

@@ -11,9 +11,9 @@
 # these requests from bringing up the link uneccessarily.
 
 # Never forward plain names (without a dot or domain part)
-domain-needed
+#domain-needed
 # Never forward addresses in the non-routed address spaces.
-bogus-priv
+#bogus-priv
 
 
 # Uncomment this to filter useless windows-originated DNS requests
@@ -382,3 +382,4 @@ bogus-priv
 
 # Include a another lot of configuration options.
 #conf-file=/etc/dnsmasq.more.conf
+#conf-dir=/etc/dnsmasq.d

man/dnsmasq.8

@@ -219,6 +219,11 @@ server strictly in the order they appear in /etc/resolv.conf
 .B \-n, --no-poll
 Don't poll /etc/resolv.conf for changes.
 .TP
+.B --clear-on-reload
+Whenever /etc/resolv.conf is re-read, clear the DNS cache.
+This is useful when new nameservers may have different
+data than that held in cache.
+.TP
 .B \-D, --domain-needed
 Tells dnsmasq to never forward queries for plain names, without dots
 or domain parts, to upstream nameservers. If the name is not known
@@ -326,11 +331,11 @@ Disable negative caching. Negative caching allows dnsmasq to remember
 identical queries without forwarding them again. This flag disables
 negative caching.
 .TP
-.B \-0, --dns-forward-max
+.B \-0, --dns-forward-max=<queries>
-Set the maximum number of concurrent DNS queries. Unanswered queries
+Set the maximum number of concurrent DNS queries. The default value is
-time out after 20 seconds. If you sometimes see the log message 
+150, which should be fine for most setups. The only known situation
-"forwarding table overflow: check for server loops." then it is worth
+where this needs to be increased is when using web-server log file
-experimenting with this setting. The default value is 150.
+resolvers, which can generate large numbers of concurrent queries.
 .TP
 .B \-F, --dhcp-range=[[net:]network-id,]<start-addr>,<end-addr>[[,<netmask>],<broadcast>][,<default lease time>]
 Enable the DHCP server. Addresses will be given out from the range
@@ -363,7 +368,7 @@ addresses given via
 .B dhcp-host
 or from /etc/ethers will be served.
 .TP
-.B \-G, --dhcp-host=[[<hwaddr>]|[id:[<client_id>][*]]][net:<netid>][,<ipaddr>][,<hostname>][,<lease_time>][,ignore]
+.B \-G, --dhcp-host=[[<hwaddr>]|[id:[<client_id>][*]]][,net:<netid>][,<ipaddr>][,<hostname>][,<lease_time>][,ignore]
 Specify per host parameters for the DHCP server. This allows a machine
 with a particular hardware address to be always allocated the same
 hostname, IP address and lease time. A hostname specified like this
@@ -557,16 +562,21 @@ if known. "add" means a lease has been created, "del" means it has
 been destroyed, "old" is a notification of an existing lease when
 dnsmasq starts or a change to MAC address or hostname of an existing
 lease (also, lease length or expiry and client-id, if leasefile-ro is set).
-The process is run as any unprivileged user which dnsmasq
+The process is run as root (assuming that dnsmasq was originally run as
-runs as, so it may be necessary to inhibit dropping of the root user,
+root) even if dnsmasq is configured to change UID to an unprivileged user.
-using the
-.B -u
-directive, if the script needs root privs.
 The environment is inherited from the invoker of dnsmasq, and if the
-host provided a client-id, this is stored in the variable
+host provided a client-id, this is stored in the environment variable
-DNSMASQ_CLIENT_ID. If dnsmasq was compiled with HAVE_BROKEN_RTC, then
+DNSMASQ_CLIENT_ID. If the client provides vendor-class or user-class 
+information, these are provided in DNSMASQ_VENDOR_CLASS and 
+DNSMASQ_USER_CLASS0..DNSMASQ_USER_CLASSn variables, but only for the
+"add" actions, since these data are not held in dnsmasq's lease
+database. If dnsmasq was compiled with HAVE_BROKEN_RTC, then
 the length of the lease (in seconds) is stored in
-DNSMASQ_LEASE_LENGTH, otherwise the time of lease expiry is stored in DNSMASQ_LEASE_EXPIRES.
+DNSMASQ_LEASE_LENGTH, otherwise the time of lease expiry is stored in
+DNSMASQ_LEASE_EXPIRES. If a lease used to have a hostname, which is
+removed, an "old" event is generated with the new state of the lease, 
+ie no name, and the former name is provided in the environment 
+variable DNSMASQ_OLD_HOSTNAME.
 All file decriptors are
 closed except stdin, stdout and stderr which are open to /dev/null
 (except in debug mode).

src/cache.c

@@ -20,6 +20,40 @@ static int bignames_left, log_queries, cache_size, hash_size;
 static int uid;
 static char *addrbuff;
 
+/* type->string mapping: this is also used by the name-hash function as a mixing table. */
+static const struct {
+  unsigned int type;
+  const char * const name;
+} typestr[] = {
+  { 1,   "A" },
+  { 2,   "NS" },
+  { 5,   "CNAME" },
+  { 6,   "SOA" },
+  { 10,  "NULL" },
+  { 11,  "WKS" },
+  { 12,  "PTR" },
+  { 13,  "HINFO" },	
+  { 15,  "MX" },
+  { 16,  "TXT" },
+  { 22,  "NSAP" },
+  { 23,  "NSAP_PTR" },
+  { 24,  "SIG" },
+  { 25,  "KEY" },
+  { 28,  "AAAA" },
+  { 33,  "SRV" },
+  { 36,  "KX" },
+  { 37,  "CERT" },
+  { 38,  "A6" },
+  { 39,  "DNAME" },
+  { 41,  "OPT" },
+  { 250, "TSIG" },
+  { 251, "IXFR" },
+  { 252, "AXFR" },
+  { 253, "MAILB" },
+  { 254, "MAILA" },
+  { 255, "ANY" }
+};
+
 static void cache_free(struct crec *crecp);
 static void cache_unlink(struct crec *crecp);
 static void cache_link(struct crec *crecp);
@@ -66,17 +100,19 @@ void cache_init(int size, int logq)
 
 static struct crec **hash_bucket(char *name)
 {
-  unsigned int c, val = 0;
+  unsigned int c, val = 017465; /* Barker code - minimum self-correlationin cyclic shift */
+  const unsigned char *mix_tab = (const unsigned char*)typestr; 
 
-  /* don't use tolower and friends here - they may be messed up by LOCALE */
   while((c = (unsigned char) *name++))
-    if (c >= 'A' && c <= 'Z')
+    {
-      val += c + 'a' - 'A';
+      /* don't use tolower and friends here - they may be messed up by LOCALE */
-    else
+      if (c >= 'A' && c <= 'Z')
-      val += c;
+	c += 'a' - 'A';
+      val = ((val << 7) | (val >> (32 - 7))) + (mix_tab[(val + c) & 0x1F] ^ c);
+    } 
   
   /* hash_size is a power of two */
-  return hash_table + (val & (hash_size - 1));
+  return hash_table + ((val ^ (val >> 16)) & (hash_size - 1));
 }
 
 static void cache_hash(struct crec *crecp)
@@ -909,38 +945,6 @@ void log_query(unsigned short flags, char *name, struct all_addr *addr,
   else if (flags & F_QUERY)
     {
       unsigned int i;
-      static const struct {
-	unsigned int type;
-	const char * const name;
-      } typestr[] = {
-	{ 1,   "A" },
-	{ 2,   "NS" },
-	{ 5,   "CNAME" },
-	{ 6,   "SOA" },
-	{ 10,  "NULL" },
-	{ 11,  "WKS" },
-	{ 12,  "PTR" },
-	{ 13,  "HINFO" },	
-        { 15,  "MX" },
-	{ 16,  "TXT" },
-	{ 22,  "NSAP" },
-	{ 23,  "NSAP_PTR" },
-	{ 24,  "SIG" },
-	{ 25,  "KEY" },
-	{ 28,  "AAAA" },
- 	{ 33,  "SRV" },
-        { 36,  "KX" },
-        { 37,  "CERT" },
-        { 38,  "A6" },
-        { 39,  "DNAME" },
-	{ 41,  "OPT" },
-	{ 250, "TSIG" },
-	{ 251, "IXFR" },
-	{ 252, "AXFR" },
-        { 253, "MAILB" },
-	{ 254, "MAILA" },
-	{ 255, "ANY" }
-      };
       
       if (type != 0)
         {

src/config.h

@@ -10,15 +10,14 @@
    GNU General Public License for more details.
 */
 
-#define VERSION "2.33"
+#define VERSION "2.34"
 
 #define FTABSIZ 150 /* max number of outstanding requests (default) */
 #define MAX_PROCS 20 /* max no children for TCP requests */
 #define CHILD_LIFETIME 150 /* secs 'till terminated (RFC1035 suggests > 120s) */
 #define EDNS_PKTSZ 1280 /* default max EDNS.0 UDP packet from RFC2671 */
-#define TIMEOUT 20 /* drop UDP queries after TIMEOUT seconds */
+#define TIMEOUT 10 /* drop UDP queries after TIMEOUT seconds */
 #define LEASE_RETRY 60 /* on error, retry writing leasefile after LEASE_RETRY seconds */
-#define LOGRATE 120 /* log table overflows every LOGRATE seconds */
 #define CACHESIZ 150 /* default cache size */
 #define MAXLEASES 150 /* maximum number of DHCP leases */
 #define PING_WAIT 3 /* wait for ping address-in-use test */

src/dbus.c

@@ -282,8 +282,8 @@ char *dbus_init(struct daemon *daemon)
 }
  
 
-int set_dbus_listeners(struct daemon *daemon, int maxfd,
+void set_dbus_listeners(struct daemon *daemon, int *maxfdp,
-		       fd_set *rset, fd_set *wset, fd_set *eset)
+			fd_set *rset, fd_set *wset, fd_set *eset)
 {
   struct watch *w;
   
@@ -293,8 +293,7 @@ int set_dbus_listeners(struct daemon *daemon, int maxfd,
 	unsigned int flags = dbus_watch_get_flags(w->watch);
 	int fd = dbus_watch_get_fd(w->watch);
 	
-	if (fd > maxfd)
+	bump_maxfd(fd, maxfdp);
-	  maxfd = fd;
 	
 	if (flags & DBUS_WATCH_READABLE)
 	  FD_SET(fd, rset);
@@ -304,7 +303,6 @@ int set_dbus_listeners(struct daemon *daemon, int maxfd,
 	
 	FD_SET(fd, eset);
       }
-  return maxfd;
 }
 
 void check_dbus_listeners(struct daemon *daemon,

src/dhcp.c

@@ -138,7 +138,7 @@ void dhcp_packet(struct daemon *daemon, time_t now)
   msg.msg_name = &dest;
   msg.msg_namelen = sizeof(dest);
 
-  while ((sz = recvmsg(daemon->dhcpfd, &msg, 0)) && errno == EINTR);
+  while ((sz = recvmsg(daemon->dhcpfd, &msg, 0)) == -1 && errno == EINTR);
  
   if ((msg.msg_flags & MSG_TRUNC) ||
       sz < (ssize_t)(sizeof(*mess) - sizeof(mess->options)))
@@ -205,7 +205,6 @@ void dhcp_packet(struct daemon *daemon, time_t now)
   iov.iov_len = dhcp_reply(daemon, parm.current, ifr.ifr_name, (size_t)sz, now, unicast_dest);
   lease_update_file(daemon, now);
   lease_update_dns(daemon);
-  lease_collect(daemon);
     
   if (iov.iov_len == 0)
     return;
@@ -625,7 +624,7 @@ void dhcp_read_ethers(struct daemon *daemon)
   struct in_addr addr;
   unsigned char hwaddr[ETHER_ADDR_LEN];
   struct dhcp_config **up, *tmp;
-  struct dhcp_config *config, *configs = daemon->dhcp_conf;
+  struct dhcp_config *config;
   int count = 0, lineno = 0;
 
   addr.s_addr = 0; /* eliminate warning */
@@ -637,7 +636,7 @@ void dhcp_read_ethers(struct daemon *daemon)
     }
 
   /* This can be called again on SIGHUP, so remove entries created last time round. */
-  for (up = &daemon->dhcp_conf, config = configs; config; config = tmp)
+  for (up = &daemon->dhcp_conf, config = daemon->dhcp_conf; config; config = tmp)
     {
       tmp = config->next;
       if (config->flags & CONFIG_FROM_ETHERS)
@@ -686,7 +685,7 @@ void dhcp_read_ethers(struct daemon *daemon)
 
 	  flags = CONFIG_ADDR;
 	  
-	  for (config = configs; config; config = config->next)
+	  for (config = daemon->dhcp_conf; config; config = config->next)
 	    if ((config->flags & CONFIG_ADDR) && config->addr.s_addr == addr.s_addr)
 	      break;
 	}
@@ -700,14 +699,14 @@ void dhcp_read_ethers(struct daemon *daemon)
 
 	  flags = CONFIG_NAME;
 
-	  for (config = configs; config; config = config->next)
+	  for (config = daemon->dhcp_conf; config; config = config->next)
 	    if ((config->flags & CONFIG_NAME) && hostname_isequal(config->hostname, ip))
 	      break;
 	}
       
       if (!config)
 	{ 
-	  for (config = configs; config; config = config->next)
+	  for (config = daemon->dhcp_conf; config; config = config->next)
 	    if ((config->flags & CONFIG_HWADDR) && 
 		config->wildcard_mask == 0 &&
 		config->hwaddr_len == ETHER_ADDR_LEN &&
@@ -721,8 +720,8 @@ void dhcp_read_ethers(struct daemon *daemon)
 		continue;
 	      config->flags = CONFIG_FROM_ETHERS;
 	      config->wildcard_mask = 0;
-	      config->next = configs;
+	      config->next = daemon->dhcp_conf;
-	      configs = config;
+	      daemon->dhcp_conf = config;
 	    }
 	  
 	  config->flags |= flags;
@@ -749,8 +748,6 @@ void dhcp_read_ethers(struct daemon *daemon)
   fclose(f);
 
   syslog(LOG_INFO, _("read %s - %d addresses"), ETHERSFILE, count);
-  
-  daemon->dhcp_conf =  configs;
 }
 
 void dhcp_update_configs(struct dhcp_config *configs)

src/dnsmasq.c

@@ -24,6 +24,9 @@ static char *compile_opts =
 #ifdef HAVE_BROKEN_RTC
 "no-RTC "
 #endif
+#ifdef NO_FORK
+"no-MMU "
+#endif
 #ifndef HAVE_ISC_READER
 "no-"
 #endif
@@ -40,7 +43,7 @@ static char *compile_opts =
 static pid_t pid;
 static int pipewrite;
 
-static int set_dns_listeners(struct daemon *daemon, fd_set *set, int maxfd);
+static int set_dns_listeners(struct daemon *daemon, time_t now, fd_set *set, int *maxfdp);
 static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now);
 static void sig_handler(int sig);
 
@@ -196,57 +199,13 @@ int main (int argc, char **argv)
   sig = SIGHUP; 
   write(pipewrite, &sig, 1);
   
-  if (daemon->options & OPT_DEBUG)   
+  if (!(daemon->options & OPT_DEBUG))   
-    {
-#ifdef LOG_PERROR
-      openlog("dnsmasq", LOG_PERROR, daemon->log_fac);
-#else
-      openlog("dnsmasq", 0, daemon->log_fac);
-#endif
-      
-#ifdef HAVE_LINUX_NETWORK
-      prctl(PR_SET_DUMPABLE, 1);
-#endif
-    }
-  else
     {
       FILE *pidfile;
-      struct passwd *ent_pw = daemon->username ? getpwnam(daemon->username) : NULL;
       fd_set test_set;
-      int maxfd, i; 
+      int maxfd = -1, i; 
       int nullfd = open("/dev/null", O_RDWR);
 
-#ifdef HAVE_LINUX_NETWORK
-      cap_user_header_t hdr = NULL;
-      cap_user_data_t data = NULL; 
-      
-      /* On linux, we keep CAP_NETADMIN (for ARP-injection) and
-	 CAP_NET_RAW (for icmp) if we're doing dhcp */
-      if (ent_pw && ent_pw->pw_uid != 0)
-	{
-	  hdr = safe_malloc(sizeof(*hdr));
-	  data = safe_malloc(sizeof(*data));
-	  hdr->version = _LINUX_CAPABILITY_VERSION;
-	  hdr->pid = 0; /* this process */
-	  data->effective = data->permitted = data->inheritable =
-	    (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) |
-	    (1 << CAP_SETGID) | (1 << CAP_SETUID);
-	  	  
-	  /* Tell kernel to not clear capabilities when dropping root */
-	  if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1) == -1)
-	    {
-	      bad_capabilities = errno;
-	      ent_pw = NULL;
-	    }
-	}
-#endif
-
-      FD_ZERO(&test_set);
-      maxfd = set_dns_listeners(daemon, &test_set, -1);
-#ifdef HAVE_DBUS
-      maxfd = set_dbus_listeners(daemon, maxfd, &test_set, &test_set, &test_set);
-#endif
-      
       /* The following code "daemonizes" the process. 
 	 See Stevens section 12.4 */
 
@@ -275,6 +234,11 @@ int main (int argc, char **argv)
       
       umask(0);
       
+      FD_ZERO(&test_set);
+      set_dns_listeners(daemon, now, &test_set, &maxfd);
+#ifdef HAVE_DBUS
+      set_dbus_listeners(daemon, &maxfd, &test_set, &test_set, &test_set);
+#endif
       for (i=0; i<64; i++)
 	{
 	  if (i == piperead || i == pipewrite)
@@ -303,6 +267,15 @@ int main (int argc, char **argv)
 	  else
 	    close(i);
 	}
+    }
+  
+  /* if we are to run scripts, we need to fork a helper before dropping root. */
+      daemon->helperfd = create_helper(daemon);
+    
+  if (!(daemon->options & OPT_DEBUG))   
+    {
+      /* UID changing, etc */
+      struct passwd *ent_pw = daemon->username ? getpwnam(daemon->username) : NULL;    
       
       if (daemon->groupname || ent_pw)
 	{
@@ -321,22 +294,45 @@ int main (int argc, char **argv)
       
       if (ent_pw && ent_pw->pw_uid != 0)
 	{     
-	  /* finally drop root */
+#ifdef HAVE_LINUX_NETWORK
-	  setuid(ent_pw->pw_uid);
+	  /* On linux, we keep CAP_NETADMIN (for ARP-injection) and
+	     CAP_NET_RAW (for icmp) if we're doing dhcp */
+	  cap_user_header_t hdr = safe_malloc(sizeof(*hdr));
+	  cap_user_data_t data = safe_malloc(sizeof(*data));
+	  hdr->version = _LINUX_CAPABILITY_VERSION;
+	  hdr->pid = 0; /* this process */
+	  data->effective = data->permitted = data->inheritable =
+	    (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW) |
+	    (1 << CAP_SETGID) | (1 << CAP_SETUID);
+	  
+	  /* Tell kernel to not clear capabilities when dropping root */
+	  if (capset(hdr, data) == -1 || prctl(PR_SET_KEEPCAPS, 1) == -1)
+	    bad_capabilities = errno;
+	  else
+#endif
+	    {
+	      /* finally drop root */
+	      setuid(ent_pw->pw_uid);
 	      
 #ifdef HAVE_LINUX_NETWORK
-	  data->effective = data->permitted = 
+	      data->effective = data->permitted = 
-	    (1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW);
+		(1 << CAP_NET_ADMIN) | (1 << CAP_NET_RAW);
-	  data->inheritable = 0;
+	      data->inheritable = 0;
 	      
-	  /* lose the setuid and setgid capbilities */
+	      /* lose the setuid and setgid capbilities */
-	  capset(hdr, data);
+	      capset(hdr, data);
 #endif
+	    }
 	}
-
-      openlog("dnsmasq", LOG_PID, daemon->log_fac);
     }
   
+  log_start(daemon);
+  
+#ifdef HAVE_LINUX_NETWORK
+  if (daemon->options & OPT_DEBUG) 
+    prctl(PR_SET_DUMPABLE, 1);
+#endif
+
   if (daemon->cachesize != 0)
     syslog(LOG_INFO, _("started, version %s cachesize %d"), VERSION, daemon->cachesize);
   else
@@ -399,52 +395,58 @@ int main (int argc, char **argv)
 
   pid = getpid();
   
-  /* Start lease-change script */
-  if (daemon->dhcp)
-    lease_collect(daemon);
-  
   while (1)
     {
-      int maxfd;
+      int maxfd = -1;
       struct timeval t, *tp = NULL;
       fd_set rset, wset, eset;
       
-      t.tv_sec = 0; /* no warning */
-      
       FD_ZERO(&rset);
       FD_ZERO(&wset);
       FD_ZERO(&eset);
       
-      maxfd = set_dns_listeners(daemon, &rset, -1);
+      /* if we are out of resources, find how long we have to wait
+	 for some to come free, we'll loop around then and restart
+	 listening for queries */
+      if ((t.tv_sec = set_dns_listeners(daemon, now, &rset, &maxfd)) != 0)
+	{
+	  t.tv_usec = 0;
+	  tp = &t;
+	}
 
 #ifdef HAVE_DBUS
       /* Whilst polling for the dbus, wake every quarter second */
       if ((daemon->options & OPT_DBUS) && !daemon->dbus)
 	{
+	  t.tv_sec = 0;
+	  t.tv_usec = 250000;
 	  tp = &t;
-	  tp->tv_sec = 0;
-	  tp->tv_usec = 250000;
 	}
 
-      maxfd = set_dbus_listeners(daemon, maxfd, &rset, &wset, &eset);
+      set_dbus_listeners(daemon, &maxfd, &rset, &wset, &eset);
 #endif	
   
       if (daemon->dhcp)
 	{
 	  FD_SET(daemon->dhcpfd, &rset);
-	  if (daemon->dhcpfd > maxfd)
+	  bump_maxfd(daemon->dhcpfd, &maxfd);
-	    maxfd = daemon->dhcpfd;
 	}
 
 #ifdef HAVE_LINUX_NETWORK
       FD_SET(daemon->netlinkfd, &rset);
-      if (daemon->netlinkfd > maxfd)
+      bump_maxfd(daemon->netlinkfd, &maxfd);
-	maxfd = daemon->netlinkfd;
 #endif
       
       FD_SET(piperead, &rset);
-      if (piperead > maxfd)
+      bump_maxfd(piperead, &maxfd);
-	maxfd = piperead;
+
+      while (helper_buf_empty() && do_script_run(daemon));
+
+      if (!helper_buf_empty())
+	{
+	  FD_SET(daemon->helperfd, &wset);
+	  bump_maxfd(daemon->helperfd, &maxfd);
+	}
 
       if (select(maxfd+1, &rset, &wset, &eset, tp) < 0)
 	{
@@ -502,6 +504,8 @@ int main (int argc, char **argv)
 		      syslog(LOG_INFO, _("reading %s"), latest->name);
 		      warned = 0;
 		      check_servers(daemon);
+		      if (daemon->options & OPT_RELOAD)
+			cache_reload(daemon->options, daemon->namebuff, daemon->domain_suffix, daemon->addn_hosts);
 		    }
 		  else 
 		    {
@@ -541,22 +545,33 @@ int main (int argc, char **argv)
 		  {
 		    lease_prune(NULL, now);
 		    lease_update_file(daemon, now);
-		    lease_collect(daemon);
 		  }
 		break;
 		
 	      case SIGTERM:
 		{
 		  int i;
-		  syslog(LOG_INFO, _("exiting on receipt of SIGTERM"));
 		  /* Knock all our children on the head. */
 		  for (i = 0; i < MAX_PROCS; i++)
 		    if (daemon->tcp_pids[i] != 0)
 		      kill(daemon->tcp_pids[i], SIGALRM);
 		  
+		  /* handle pending lease transitions */
+		  if (daemon->helperfd != -1)
+		    {
+		      /* block in writes until all done */
+		      if ((i = fcntl(daemon->helperfd, F_GETFL)) != -1)
+			fcntl(daemon->helperfd, F_SETFL, i & ~O_NONBLOCK); 
+		      do {
+			helper_write(daemon);
+		      } while (!helper_buf_empty() || do_script_run(daemon));
+		      close(daemon->helperfd);
+		    }
+		     
 		  if (daemon->lease_stream)
 		    fclose(daemon->lease_stream);
 
+		  syslog(LOG_INFO, _("exiting on receipt of SIGTERM"));
 		  exit(0);
 		}
 
@@ -568,22 +583,13 @@ int main (int argc, char **argv)
 		   whose pid != script_pid are TCP server threads. */ 
 		while ((p = waitpid(-1, NULL, WNOHANG)) > 0)
 		  {
-		    if (p == daemon->script_pid)
+		    int i;
-		      {
+		    for (i = 0 ; i < MAX_PROCS; i++)
-			daemon->script_pid = 0;
+		      if (daemon->tcp_pids[i] == p)
-			lease_collect(daemon);
+			{
-		      }
+			  daemon->tcp_pids[i] = 0;
-		    else
+			  break;
-		      {
+			}
-			int i;
-			for (i = 0 ; i < MAX_PROCS; i++)
-			  if (daemon->tcp_pids[i] == p)
-			    {
-			      daemon->tcp_pids[i] = 0;
-			      daemon->num_kids--;
-			      break;
-			    }
-		      }
 		  }
 		break;
 	      }
@@ -611,6 +617,9 @@ int main (int argc, char **argv)
       
       if (daemon->dhcp && FD_ISSET(daemon->dhcpfd, &rset))
 	dhcp_packet(daemon, now);
+
+      if (daemon->helperfd != -1 && FD_ISSET(daemon->helperfd, &wset))
+	helper_write(daemon);
     }
 }
 
@@ -618,7 +627,8 @@ static void sig_handler(int sig)
 {
   if (pid == 0)
     {
-      /* ignore anything other than TERM during startup */
+      /* ignore anything other than TERM during startup
+	 and in helper proc. (helper ignore TERM too) */
       if (sig == SIGTERM)
 	exit(0);
     }
@@ -632,7 +642,7 @@ static void sig_handler(int sig)
     }
   else
     {
-      /* alarm is used to kill children after a fixed time. */
+      /* alarm is used to kill TCP children after a fixed time. */
       if (sig == SIGALRM)
 	_exit(0);
     }
@@ -653,29 +663,42 @@ void clear_cache_and_reload(struct daemon *daemon, time_t now)
     }
 }
 
-static int set_dns_listeners(struct daemon *daemon, fd_set *set, int maxfd)
+static int set_dns_listeners(struct daemon *daemon, time_t now, fd_set *set, int *maxfdp)
 {
   struct serverfd *serverfdp;
   struct listener *listener;
+  int wait, i;
+
+  /* will we be able to get memory? */
+  get_new_frec(daemon, now, &wait);
   
   for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
     {
       FD_SET(serverfdp->fd, set);
-      if (serverfdp->fd > maxfd)
+      bump_maxfd(serverfdp->fd, maxfdp);
-	maxfd = serverfdp->fd;
     }
 	  
   for (listener = daemon->listeners; listener; listener = listener->next)
     {
-      FD_SET(listener->fd, set);
+      /* only listen for queries if we have resources */
-      if (listener->fd > maxfd)
+      if (wait == 0)
-	maxfd = listener->fd;
+	{
-      FD_SET(listener->tcpfd, set);
+	  FD_SET(listener->fd, set);
-      if (listener->tcpfd > maxfd)
+	  bump_maxfd(listener->fd, maxfdp);
-	maxfd = listener->tcpfd;
+	}
+
+      /* death of a child goes through the select loop, so
+	 we don't need to explicitly arrange to wake up here */
+      for (i = 0; i < MAX_PROCS; i++)
+	if (daemon->tcp_pids[i] == 0)
+	  {
+	    FD_SET(listener->tcpfd, set);
+	    bump_maxfd(listener->tcpfd, maxfdp);
+	    break;
+	  }
     }
 
-  return maxfd;
+  return wait;
 }
 
 static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now)
@@ -723,7 +746,7 @@ static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now)
 		     break;
 	     }
 	   
-	   if ((daemon->num_kids >= MAX_PROCS) || !iface)
+	   if (!iface)
 	     {
 	       shutdown(confd, SHUT_RDWR);
 	       close(confd);
@@ -740,7 +763,6 @@ static void check_dns_listeners(struct daemon *daemon, fd_set *set, time_t now)
 			 daemon->tcp_pids[i] = p;
 			 break;
 		       }
-		   daemon->num_kids++;
 		 }
 	       close(confd);
 	     }
@@ -869,7 +891,7 @@ int icmp_ping(struct daemon *daemon, struct in_addr addr)
       struct timeval tv;
       fd_set rset;
       struct sockaddr_in faddr;
-      int maxfd; 
+      int maxfd = fd; 
       socklen_t len = sizeof(faddr);
       
       tv.tv_usec = 250000;
@@ -877,7 +899,7 @@ int icmp_ping(struct daemon *daemon, struct in_addr addr)
       
       FD_ZERO(&rset);
       FD_SET(fd, &rset);
-      maxfd = set_dns_listeners(daemon, &rset, fd);
+      set_dns_listeners(daemon, now, &rset, &maxfd);
 		
       if (select(maxfd+1, &rset, NULL, NULL, &tv) < 0)
 	FD_ZERO(&rset);

src/dnsmasq.h

@@ -111,6 +111,7 @@ extern int capset(cap_user_header_t header, cap_user_data_t data);
 #define OPT_BOOTP_DYNAMIC  1048576
 #define OPT_NO_PING        2097152
 #define OPT_LEASE_RO       4194304
+#define OPT_RELOAD         8388608
 
 struct all_addr {
   union {
@@ -229,8 +230,7 @@ struct serverfd {
 
 struct server {
   union mysockaddr addr, source_addr;
-  struct serverfd *sfd; /* non-NULL if this server has its own fd bound to
+  struct serverfd *sfd; 
-			   a source port */
   char *domain; /* set if this server only handles a domain. */ 
   int flags, tcpfd;
   struct server *next; 
@@ -283,12 +283,19 @@ struct frec {
   struct frec *next;
 };
 
+/* actions in the daemon->helper RPC */
+#define ACTION_DEL           1
+#define ACTION_OLD_HOSTNAME  2
+#define ACTION_OLD           3
+#define ACTION_ADD           4
+
 #define DHCP_CHADDR_MAX 16
 
 struct dhcp_lease {
   int clid_len;          /* length of client identifier */
   unsigned char *clid;   /* clientid */
   char *hostname, *fqdn; /* name from client-hostname option or config */
+  char *old_hostname;    /* hostname before it moved to another lease */
   char auth_name;        /* hostname came from config, not from client */
   char new;              /* newly created */
   char changed;          /* modified */
@@ -300,6 +307,8 @@ struct dhcp_lease {
   int hwaddr_len, hwaddr_type;
   unsigned char hwaddr[DHCP_CHADDR_MAX]; 
   struct in_addr addr;
+  unsigned char *vendorclass, *userclass;
+  unsigned int vendorclass_len, userclass_len;
   struct dhcp_lease *next;
 };
 
@@ -312,6 +321,7 @@ struct dhcp_netid_list {
   struct dhcp_netid *list;
   struct dhcp_netid_list *next;
 };
+
 struct dhcp_config {
   unsigned int flags;
   int clid_len;          /* length of client identifier */
@@ -450,11 +460,10 @@ struct daemon {
   struct server *last_server;
   struct server *srv_save; /* Used for resend on DoD */
   size_t packet_len;       /*      "        "        */
-  pid_t script_pid, tcp_pids[MAX_PROCS];
+  pid_t tcp_pids[MAX_PROCS];
-  int num_kids;
  
   /* DHCP state */
-  int dhcpfd; 
+  int dhcpfd, helperfd; 
 #ifdef HAVE_LINUX_NETWORK
   int netlinkfd;
 #else
@@ -534,6 +543,9 @@ int memcmp_masked(unsigned char *a, unsigned char *b, int len,
 		  unsigned int mask);
 int expand_buf(struct iovec *iov, size_t size);
 char *print_mac(struct daemon *daemon, unsigned char *mac, int len);
+void bump_maxfd(int fd, int *max);
+void log_start(struct daemon *daemon);
+int read_write(int fd, unsigned char *packet, int size, int rw);
 
 /* option.c */
 struct daemon *read_opts (int argc, char **argv, char *compile_opts);
@@ -544,6 +556,7 @@ void receive_query(struct listener *listen, struct daemon *daemon, time_t now);
 unsigned char *tcp_request(struct daemon *daemon, int confd, time_t now,
 			   struct in_addr local_addr, struct in_addr netmask);
 void server_gone(struct daemon *daemon, struct server *server);
+struct frec *get_new_frec(struct daemon *daemon, time_t now, int *wait);
 
 /* network.c */
 struct serverfd *allocate_sfd(union mysockaddr *addr, struct serverfd **sfds);
@@ -592,7 +605,7 @@ struct dhcp_lease *lease_find_by_client(unsigned char *hwaddr, int hw_len, int h
 struct dhcp_lease *lease_find_by_addr(struct in_addr addr);
 void lease_prune(struct dhcp_lease *target, time_t now);
 void lease_update_from_configs(struct daemon *daemon);
-void lease_collect(struct daemon *daemon);
+int do_script_run(struct daemon *daemon);
 
 /* rfc2131.c */
 size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *iface_name, size_t sz, time_t now, int unicast_dest);
@@ -629,6 +642,13 @@ int iface_enumerate(struct daemon *daemon, void *parm,
 char *dbus_init(struct daemon *daemon);
 void check_dbus_listeners(struct daemon *daemon,
 			  fd_set *rset, fd_set *wset, fd_set *eset);
-int set_dbus_listeners(struct daemon *daemon, int maxfd, 
+void set_dbus_listeners(struct daemon *daemon, int *maxfdp, 
-		       fd_set *rset, fd_set *wset, fd_set *eset);
+			fd_set *rset, fd_set *wset, fd_set *eset);
 #endif
+
+/* helper.c */
+int create_helper(struct daemon *daemon);
+void helper_write(struct daemon *daemon);
+void queue_script(struct daemon *daemon, int action, 
+		  struct dhcp_lease *lease, char *hostname);
+int helper_buf_empty(void);

src/forward.c

@@ -14,7 +14,6 @@
 
 static struct frec *frec_list = NULL;
 
-static struct frec *get_new_frec(struct daemon *daemon, time_t now);
 static struct frec *lookup_frec(unsigned short id);
 static struct frec *lookup_frec_by_sender(unsigned short id,
 					  union mysockaddr *addr,
@@ -232,7 +231,7 @@ static void forward_query(struct daemon *daemon, int udpfd, union mysockaddr *ud
       if (gotname)
 	flags = search_servers(daemon, now, &addrp, gotname, daemon->namebuff, &type, &domain);
       
-      if (!flags && !(forward = get_new_frec(daemon, now)))
+      if (!flags && !(forward = get_new_frec(daemon, now, NULL)))
 	/* table full - server failure. */
 	flags = F_NEG;
       
@@ -459,7 +458,6 @@ void reply_query(struct serverfd *sfd, struct daemon *daemon, time_t now)
 	   header->arcount = htons(0);
 	   if ((nn = resize_packet(header, (size_t)n, pheader, plen)))
 	     {
-	       forward->forwardall = 1;
 	       header->qr = 0;
 	       header->tc = 0;
 	       forward_query(daemon, -1, NULL, NULL, 0, header, nn, now, forward);
@@ -657,31 +655,6 @@ void receive_query(struct listener *listen, struct daemon *daemon, time_t now)
 		  header, (size_t)n, now, NULL);
 }
 
-static int read_write(int fd, unsigned char *packet, int size, int rw)
-{
-  ssize_t n, done;
-  
-  for (done = 0; done < size; done += n)
-    {
-    retry:
-      if (rw)
-	n = read(fd, &packet[done], (size_t)(size - done));
-      else
-	n = write(fd, &packet[done], (size_t)(size - done));
-
-      if (n == 0)
-	return 0;
-      else if (n == -1)
-	{
-	  if (errno == EINTR)
-	    goto retry;
-	  else
-	    return 0;
-	}
-    }
-  return 1;
-}
-  
 /* The daemon forks before calling this: it should deal with one connection,
    blocking as neccessary, and then return. Note, need to be a bit careful
    about resources for debug mode, when the fork is suppressed: that's
@@ -837,48 +810,9 @@ unsigned char *tcp_request(struct daemon *daemon, int confd, time_t now,
     }
 }
 
-static struct frec *get_new_frec(struct daemon *daemon, time_t now)
+static struct frec *allocate_frec(time_t now)
 {
-  struct frec *f = frec_list, *oldest = NULL;
+  struct frec *f;
-  time_t oldtime = now;
-  int count = 0;
-  static time_t warntime = 0;
-
-  while (f)
-    {
-      if (f->new_id == 0)
-	{
-	  f->time = now;
-	  return f;
-	}
-
-      if (difftime(f->time, oldtime) <= 0)
-	{
-	  oldtime = f->time;
-	  oldest = f;
-	}
-
-      count++;
-      f = f->next;
-    }
-  
-  /* can't find empty one, use oldest if there is one
-     and it's older than timeout */
-  if (oldest && difftime(now, oldtime)  > TIMEOUT)
-    { 
-      oldest->time = now;
-      return oldest;
-    }
-  
-  if (count > daemon->ftabsize)
-    { /* limit logging rate so syslog isn't DOSed either */
-      if (!warntime || difftime(now, warntime) > LOGRATE)
-	{
-	  warntime = now;
-	  syslog(LOG_WARNING, _("forwarding table overflow: check for server loops."));
-	}
-      return NULL;
-    }
   
   if ((f = (struct frec *)malloc(sizeof(struct frec))))
     {
@@ -887,6 +821,61 @@ static struct frec *get_new_frec(struct daemon *daemon, time_t now)
       f->new_id = 0;
       frec_list = f;
     }
+
+  return f;
+}
+
+/* if wait==NULL return a free or older than TIMEOUT record.
+   else return *wait zero if one available, or *wait is delay to
+   when the oldest in-use record will expire. */
+struct frec *get_new_frec(struct daemon *daemon, time_t now, int *wait)
+{
+  struct frec *f, *oldest;
+  int count;
+  
+  if (wait)
+    *wait = 0;
+
+  for (f = frec_list, oldest = NULL, count = 0; f; f = f->next, count++)
+    if (f->new_id == 0)
+      {
+	f->time = now;
+	return f;
+      }
+    else if (!oldest || difftime(f->time, oldest->time) <= 0)
+      oldest = f;
+  
+  /* can't find empty one, use oldest if there is one
+     and it's older than timeout */
+  if (oldest && ((int)difftime(now, oldest->time)) >= TIMEOUT)
+    { 
+      /* keep stuff for twice timeout if we can by allocating a new
+	 record instead */
+      if (difftime(now, oldest->time) < 2*TIMEOUT && 
+	  count <= daemon->ftabsize &&
+	  (f = allocate_frec(now)))
+	return f;
+
+      if (!wait)
+	{
+	  oldest->new_id = 0;
+	  oldest->time = now;
+	}
+      return oldest;
+    }
+  
+  /* none available, calculate time 'till oldest record expires */
+  if (count > daemon->ftabsize)
+    {
+      if (oldest && wait)
+	*wait = oldest->time + (time_t)TIMEOUT - now;
+      return NULL;
+    }
+  
+  if (!(f = allocate_frec(now)) && wait)
+    /* wait one second on malloc failure */
+    *wait = 1;
+
   return f; /* OK if malloc fails and this is NULL */
 }
  

src/helper.c

@@ -0,0 +1,330 @@
+/* dnsmasq is Copyright (c) 2000-2006 Simon Kelley
+
+   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.
+
+   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.
+*/
+
+#include "dnsmasq.h"
+
+/* This file has code to fork a helper process which recieves data via a pipe 
+   shared with the main process and which is responsible for calling a script when
+   DHCP leases change.
+
+   The helper process is forked before the main process drops root, so it retains root 
+   privs to pass on to the script. For this reason it tries to be paranoid about 
+   data received from the main process, in case that has been compromised. We don't
+   want the helper to give an attacker root. In particular, the script to be run is
+   not settable via the pipe, once the fork has taken place it is not alterable by the 
+   main process.
+*/
+
+struct script_data
+{
+  unsigned char action, hwaddr_len, hwaddr_type;
+  unsigned char clid_len, hostname_len, uclass_len, vclass_len;
+  struct in_addr addr;
+#ifdef HAVE_BROKEN_RTC
+  unsigned int length;
+#else
+  time_t expires;
+#endif
+  unsigned char hwaddr[DHCP_CHADDR_MAX];
+};
+
+static struct script_data *buf;
+static size_t bytes_in_buf, buf_size;
+
+int create_helper(struct daemon *daemon)
+{
+  pid_t pid;
+  int i, pipefd[2];
+  struct sigaction sigact;
+
+  buf = NULL;
+  buf_size = bytes_in_buf = 0;
+
+  if (!daemon->dhcp || !daemon->lease_change_command)
+    return -1;
+
+  /* create the pipe through which the main program sends us commands,
+   then fork our process. */
+  if (pipe(pipefd) == -1 || !fix_fd(pipefd[1]) || (pid = fork()) == -1)
+    return -1;
+  
+  if (pid != 0)
+    {
+      close(pipefd[0]); /* close reader side */
+      return pipefd[1];
+    }
+
+  /* ignore SIGTERM, so that we can clean up when the main process gets hit */
+  sigact.sa_handler = SIG_IGN;
+  sigact.sa_flags = 0;
+  sigemptyset(&sigact.sa_mask);
+  sigaction(SIGTERM, &sigact, NULL);
+
+  /* close all the sockets etc, we don't need them here */
+  for (i = 0; i < 64; i++)
+    if (i != STDOUT_FILENO && i != STDERR_FILENO && 
+	i != STDIN_FILENO && i != pipefd[0])
+      close(i);
+
+  /* we open our own log connection. */
+  log_start(daemon);
+  
+  /* don't give our end of the pipe to our children */
+  if ((i = fcntl(pipefd[0], F_GETFD)) != -1)
+    fcntl(pipefd[0], F_SETFD, i | FD_CLOEXEC); 
+      
+  /* loop here */
+  while(1)
+    {
+      struct script_data data;
+      char *p, *action_str, *hostname = NULL;
+      unsigned char *buf = (unsigned char *)daemon->namebuff;
+
+      /* we read zero bytes when pipe closed: this is our signal to exit */ 
+      if (!read_write(pipefd[0], (unsigned char *)&data, sizeof(data), 1))
+	_exit(0);
+      
+      if (data.action == ACTION_DEL)
+	action_str = "del";
+      else if (data.action == ACTION_ADD)
+	action_str = "add";
+      else if (data.action == ACTION_OLD || data.action == ACTION_OLD_HOSTNAME)
+	action_str = "old";
+      else
+	continue;
+	
+      /* stringify MAC into dhcp_buff */
+      p = daemon->dhcp_buff;
+      if (data.hwaddr_type != ARPHRD_ETHER || data.hwaddr_len == 0) 
+	p += sprintf(p, "%.2x-", data.hwaddr_type);
+      for (i = 0; (i < data.hwaddr_len) && (i < DHCP_CHADDR_MAX); i++)
+	{
+	  p += sprintf(p, "%.2x", data.hwaddr[i]);
+	  if (i != data.hwaddr_len - 1)
+	    p += sprintf(p, ":");
+	}
+      
+      /* and CLID into packet */
+      if (!read_write(pipefd[0], buf, data.clid_len, 1))
+	continue;
+      for (p = daemon->packet, i = 0; i < data.clid_len; i++)
+	{
+	  p += sprintf(p, "%.2x", buf[i]);
+	  if (i != data.clid_len - 1) 
+	    p += sprintf(p, ":");
+	}
+      
+      /* and expiry or length into dhcp_buff2 */
+#ifdef HAVE_BROKEN_RTC
+      sprintf(daemon->dhcp_buff2, "%u ", data.length);
+#else
+      sprintf(daemon->dhcp_buff2, "%lu ", (unsigned long)data.expires);
+#endif
+      
+      if (!read_write(pipefd[0], buf, data.hostname_len + data.uclass_len + data.vclass_len, 1))
+	continue;
+      
+      if ((pid = fork()) == -1)
+	continue;
+      
+      /* wait for child to complete */
+      if (pid != 0)
+	{
+	  int status;
+	  waitpid(pid, &status, 0);
+	  if (WIFSIGNALED(status))
+	    syslog(LOG_WARNING, _("child process killed by signal %d"), WTERMSIG(status));
+	  else if (WIFEXITED(status) && WEXITSTATUS(status) != 0)
+	    syslog(LOG_WARNING, _("child process exited with status %d"), WEXITSTATUS(status));
+	  continue;
+	}
+      
+      if (data.clid_len != 0)
+	setenv("DNSMASQ_CLIENT_ID", daemon->packet, 1);
+      else
+	unsetenv("DNSMASQ_CLIENT_ID");
+      
+#ifdef HAVE_BROKEN_RTC
+      setenv("DNSMASQ_LEASE_LENGTH", daemon->dhcp_buff2, 1);
+      unsetenv("DNSMASQ_LEASE_EXPIRES");
+#else
+      setenv("DNSMASQ_LEASE_EXPIRES", daemon->dhcp_buff2, 1); 
+      unsetenv("DNSMASQ_LEASE_LENGTH");
+#endif
+      
+      if (data.vclass_len != 0)
+	{
+	  buf[data.vclass_len - 1] = 0; /* don't trust zero-term */
+	  /* cannot have = chars in env - truncate if found . */
+	  if ((p = strchr((char *)buf, '=')))
+	    *p = 0;
+	  setenv("DNSMASQ_VENDOR_CLASS", (char *)buf, 1);
+	  buf += data.vclass_len;
+	}
+      else 
+	unsetenv("DNSMASQ_VENDOR_CLASS");
+      
+      if (data.uclass_len != 0)
+	{
+	  unsigned char *end = buf + data.uclass_len;
+	  buf[data.uclass_len - 1] = 0; /* don't trust zero-term */
+	  
+	  for (i = 0; buf < end;)
+	    {
+	      size_t len = strlen((char *)buf) + 1;
+	      if ((p = strchr((char *)buf, '=')))
+		*p = 0;
+	      if (strlen((char *)buf) != 0)
+		{
+		  sprintf(daemon->dhcp_buff2, "DNSMASQ_USER_CLASS%i", i++);
+		  setenv(daemon->dhcp_buff2, (char *)buf, 1);
+		}
+	      buf += len;
+	    }
+	}
+      
+      if (data.hostname_len != 0)
+	{
+	  hostname = (char *)buf;
+	  hostname[data.hostname_len - 1] = 0;
+	  canonicalise(hostname);
+	}
+      
+      if (data.action == ACTION_OLD_HOSTNAME && hostname)
+	{
+	  setenv("DNSMASQ_OLD_HOSTNAME", hostname, 1);
+	  hostname = NULL;
+	}
+      else
+	unsetenv("DNSMASQ_OLD_HOSTNAME");
+      
+      p =  strrchr(daemon->lease_change_command, '/');
+      execl(daemon->lease_change_command, 
+	    p ? p+1 : daemon->lease_change_command,
+	    action_str, daemon->dhcp_buff, inet_ntoa(data.addr), hostname, (char*)NULL);
+      
+      /* log socket should still be open, right? */
+      syslog(LOG_ERR, _("failed to execute %s: %m"), 
+	     daemon->lease_change_command);
+      _exit(0); 
+    }
+}
+
+/* pack up lease data into a buffer */    
+void queue_script(struct daemon *daemon, int action, struct dhcp_lease *lease, char *hostname)
+{
+  unsigned char *p;
+  size_t size;
+  unsigned int hostname_len = 0, clid_len = 0, vclass_len = 0, uclass_len = 0;
+
+  /* no script */
+  if (daemon->helperfd == -1)
+    return;
+
+  if (action == ACTION_ADD)
+    {
+      if (lease->vendorclass)
+	vclass_len = lease->vendorclass_len;
+      if (lease->userclass)
+	uclass_len = lease->userclass_len;
+    }
+  if (lease->clid)
+    clid_len = lease->clid_len;
+  if (hostname)
+    hostname_len = strlen(hostname) + 1;
+
+  size = sizeof(struct script_data) +  clid_len + vclass_len + uclass_len + hostname_len;
+
+  if (size > buf_size)
+    {
+      struct script_data *new;
+      
+      /* start with resonable size, will almost never need extending. */
+      if (size < sizeof(struct script_data) + 200)
+	size = sizeof(struct script_data) + 200;
+
+      if (!(new = malloc(size)))
+	return;
+      if (buf)
+	free(buf);
+      buf = new;
+      buf_size = size;
+    }
+
+  buf->action = action;
+  buf->hwaddr_len = lease->hwaddr_len;
+  buf->hwaddr_type = lease->hwaddr_type;
+  buf->clid_len = clid_len;
+  buf->vclass_len = vclass_len;
+  buf->uclass_len = uclass_len;
+  buf->hostname_len = hostname_len;
+  buf->addr = lease->addr;
+  memcpy(buf->hwaddr, lease->hwaddr, lease->hwaddr_len);
+#ifdef HAVE_BROKEN_RTC 
+  buf->length = lease->length;
+#else
+  buf->expires = lease->expires;
+#endif
+ 
+  p = (unsigned char *)(buf+1);
+  if (buf->clid_len != 0)
+    {
+      memcpy(p, lease->clid, clid_len);
+      p += clid_len;
+    }
+  if (buf->vclass_len != 0)
+    {
+      memcpy(p, lease->vendorclass, vclass_len);
+      p += vclass_len;
+    }
+  if (buf->uclass_len != 0)
+    {
+      memcpy(p, lease->userclass, uclass_len);
+      p += uclass_len;
+    }
+  if (buf->hostname_len != 0)
+    {
+      memcpy(p, hostname, hostname_len);
+      p += hostname_len;
+    }
+
+  bytes_in_buf = p - (unsigned char *)buf;
+}
+
+int helper_buf_empty(void)
+{
+  return bytes_in_buf == 0;
+}
+
+void helper_write(struct daemon *daemon)
+{
+  ssize_t rc;
+
+  if (bytes_in_buf == 0)
+    return;
+  
+  if ((rc = write(daemon->helperfd, buf, bytes_in_buf)) != -1)
+    {
+      if (bytes_in_buf != (size_t)rc)
+	memmove(buf, buf + rc, bytes_in_buf - rc); 
+      bytes_in_buf -= rc;
+    }
+  else
+    {
+      if (errno == EAGAIN || errno == EINTR)
+	return;
+      bytes_in_buf = 0;
+    }
+}
+
+
+

src/lease.c

@@ -418,8 +418,11 @@ void lease_set_hostname(struct dhcp_lease *lease, char *name, char *suffix, int
 	  {
 	    if (lease_tmp->auth_name && !auth)
 	      return;
-	    lease_tmp->changed = 1; /* call script on change */
+	    /* this shouldn't happen unless updates are very quick and the
-	    new_name = lease_tmp->hostname;
+	       script very slow, we just avoid a memory leak if it does. */
+	    if (lease_tmp->old_hostname)
+	      free(lease_tmp->old_hostname);
+	    lease_tmp->old_hostname = lease_tmp->hostname;
 	    lease_tmp->hostname = NULL;
 	    if (lease_tmp->fqdn)
 	      {
@@ -441,7 +444,13 @@ void lease_set_hostname(struct dhcp_lease *lease, char *name, char *suffix, int
     }
 
   if (lease->hostname)
-    free(lease->hostname);
+    {
+      /* run script to say we lost our old name */
+      if (lease->old_hostname)
+	free(lease->old_hostname);
+      lease->old_hostname = lease->hostname;
+    }
+
   if (lease->fqdn)
     free(lease->fqdn);
   
@@ -454,121 +463,81 @@ void lease_set_hostname(struct dhcp_lease *lease, char *name, char *suffix, int
   lease->changed = 1; /* run script on change */
 }
 
-
-#ifndef NO_FORK
-static pid_t run_script(struct daemon *daemon, char *action, struct dhcp_lease *lease)
-{
-  if (daemon->lease_change_command)
-    {
-      char *addr = inet_ntoa(lease->addr);
-      char *com = strrchr(daemon->lease_change_command, '/');
-      char *p;
-      pid_t pid;
-      int i;
-
-      /* stringify MAC into dhcp_buff */
-      p = daemon->dhcp_buff;
-      if (lease->hwaddr_type != ARPHRD_ETHER || lease->hwaddr_len == 0) 
-	p += sprintf(p, "%.2x-", lease->hwaddr_type);
-      for (i = 0; i < lease->hwaddr_len; i++)
-	{
-	  p += sprintf(p, "%.2x", lease->hwaddr[i]);
-	  if (i != lease->hwaddr_len - 1)
-	    p += sprintf(p, ":");
-	}
-      
-      /* and CLID into namebuff */
-      p = daemon->namebuff;
-      if (lease->clid)
-	for (i = 0; i < lease->clid_len; i++)
-	  {
-	    p += sprintf(p, "%.2x", lease->clid[i]);
-	    if (i != lease->clid_len - 1) 
-	      p += sprintf(p, ":");
-	  }
-      
-      /* and expiry or length into dhcp_buff2 */
-#ifdef HAVE_BROKEN_RTC
-      sprintf(daemon->dhcp_buff2, "%u ", lease->length);
-#else
-      sprintf(daemon->dhcp_buff2, "%lu ", (unsigned long)lease->expires);
-#endif
-
-      pid = fork();
-      
-      if (pid == -1)
-	return 0; /* fork error */
-      else if (pid != 0)
-	return pid;
-      
-      if (lease->clid && lease->clid_len != 0)
-	setenv("DNSMASQ_CLIENT_ID", daemon->namebuff, 1);
-      else
-	unsetenv("DNSMASQ_CLIENT_ID");
-
-#ifdef HAVE_BROKEN_RTC
-      setenv("DNSMASQ_LEASE_LENGTH", daemon->dhcp_buff2, 1);
-      unsetenv("DNSMASQ_LEASE_EXPIRES");
-#else
-      setenv("DNSMASQ_LEASE_EXPIRES", daemon->dhcp_buff2, 1); 
-      unsetenv("DNSMASQ_LEASE_LENGTH");
-#endif
-
-      execl(daemon->lease_change_command, 
-	    com ? com+1 : daemon->lease_change_command,
-	    action, daemon->dhcp_buff, addr, lease->hostname, (char*)NULL);
-      
-      /* log socket should still be open, right? */
-      syslog(LOG_ERR, _("failed to execute %s: %m"), 
-	     daemon->lease_change_command);
-      _exit(0);	
-    }
-
-  return 0;
-}
-#endif
-
 /* deleted leases get transferred to the old_leases list.
    remove them here, after calling the lease change
-   script. Also run the lease change script on new leases */
+   script. Also run the lease change script on new/modified leases.
-void lease_collect(struct daemon *daemon)
+
+   Return zero if nothing to do. */
+int do_script_run(struct daemon *daemon)
 {
   struct dhcp_lease *lease;
 
-  while (old_leases)
+  if (old_leases)
     {
-      if (daemon->script_pid != 0)
-	return; /* busy */
-      
       lease = old_leases;
-      old_leases = lease->next;
                   
-#ifndef NO_FORK
+      /* If the lease still has an old_hostname, do the "old" action on that first */
-      daemon->script_pid = run_script(daemon, "del", lease);
+      if (lease->old_hostname)
-#endif
+	{
+	  queue_script(daemon, ACTION_OLD_HOSTNAME, lease, lease->old_hostname);
+	  free(lease->old_hostname);
+	  lease->old_hostname = NULL;
+	  return 1;
+	}
+      else 
+	{
+	  queue_script(daemon, ACTION_DEL, lease, lease->hostname);
+	  old_leases = lease->next;
 	  
-      if (lease->hostname)
+	  if (lease->hostname)
-	free(lease->hostname); 
+	    free(lease->hostname); 
-      if (lease->fqdn)
+	  if (lease->fqdn)
-	free(lease->fqdn);
+	    free(lease->fqdn);
-      if (lease->clid)
+	  if (lease->clid)
-	free(lease->clid);
+	    free(lease->clid);
-      free(lease);
+	  if (lease->vendorclass)
+	    free(lease->vendorclass);
+	  if (lease->userclass)
+	    free(lease->userclass);
+	  free(lease);
+	    
+	  return 1; 
+	}
     }
   
+  /* make sure we announce the loss of a hostname before its new location. */
+  for (lease = leases; lease; lease = lease->next)
+    if (lease->old_hostname)
+      {	
+	queue_script(daemon, ACTION_OLD_HOSTNAME, lease, lease->old_hostname);
+	free(lease->old_hostname);
+	lease->old_hostname = NULL;
+	return 1;
+      }
+  
   for (lease = leases; lease; lease = lease->next)
     if (lease->new || lease->changed || 
 	(lease->aux_changed && (daemon->options & OPT_LEASE_RO)))
       {
-	if (daemon->script_pid != 0)
+	queue_script(daemon, lease->new ? ACTION_ADD : ACTION_OLD, lease, lease->hostname);
-	  return; /* busy */
-
-#ifndef NO_FORK
-	daemon->script_pid = run_script(daemon, lease->new ? "add" : "old", lease);
-#endif
-
 	lease->new = lease->changed = lease->aux_changed = 0;
+	
+	/* these are used for the "add" call, then junked, since they're not in the database */
+	if (lease->vendorclass)
+	  {
+	    free(lease->vendorclass);
+	    lease->vendorclass = NULL;
+	  }
+	if (lease->userclass)
+	  {
+	    free(lease->userclass);
+	    lease->userclass = NULL;
+	  }
+	
+	return 1;
       }
+
+  return 0; /* nothing to do */
 }
 	  
 

src/network.c

@@ -403,6 +403,14 @@ void check_servers(struct daemon *daemon)
 	{
 	  port = prettyprint_addr(&new->addr, daemon->namebuff);
 
+	  /* 0.0.0.0 is nothing, the stack treats it like 127.0.0.1 */
+	  if (new->addr.sa.sa_family == AF_INET &&
+	      new->addr.in.sin_addr.s_addr == 0)
+	    {
+	      free(new);
+	      continue;
+	    }
+
 	  for (iface = daemon->interfaces; iface; iface = iface->next)
 	    if (sockaddr_isequal(&new->addr, &iface->addr))
 	      break;

src/option.c

@@ -26,6 +26,10 @@ struct myoption {
 
 #define OPTSTRING "9531yZDNLERKzowefnbvhdkqr:m:p:c:l:s:i:t:u:g:a:x:S:C:A:T:H:Q:I:B:F:G:O:M:X:V:U:j:P:J:W:Y:2:4:6:7:8:0:"
 
+/* options which don't have a one-char version */
+#define LOPT_RELOAD 256
+
+
 #ifdef HAVE_GETOPT_LONG
 static const struct option opts[] =  
 #else
@@ -97,39 +101,41 @@ static const struct myoption opts[] =
     {"log-facility", 1, 0 ,'8'},
     {"leasefile-ro", 0, 0, '9'},
     {"dns-forward-max", 1, 0, '0'},
+    {"clear-on-reload", 0, 0, LOPT_RELOAD },
     { NULL, 0, 0, 0 }
   };
 
 struct optflags {
-  char c;
+  int c;
   unsigned int flag; 
 };
 
 static const struct optflags optmap[] = {
-  { 'b', OPT_BOGUSPRIV },
+  { 'b',            OPT_BOGUSPRIV },
-  { 'f', OPT_FILTER },
+  { 'f',            OPT_FILTER },
-  { 'q', OPT_LOG },
+  { 'q',            OPT_LOG },
-  { 'e', OPT_SELFMX },
+  { 'e',            OPT_SELFMX },
-  { 'h', OPT_NO_HOSTS },
+  { 'h',            OPT_NO_HOSTS },
-  { 'n', OPT_NO_POLL },
+  { 'n',            OPT_NO_POLL },
-  { 'd', OPT_DEBUG },
+  { 'd',            OPT_DEBUG },
-  { 'k', OPT_NO_FORK },
+  { 'k',            OPT_NO_FORK },
-  { 'K', OPT_AUTHORITATIVE },
+  { 'K',            OPT_AUTHORITATIVE },
-  { 'o', OPT_ORDER },
+  { 'o',            OPT_ORDER },
-  { 'R', OPT_NO_RESOLV },
+  { 'R',            OPT_NO_RESOLV },
-  { 'E', OPT_EXPAND },
+  { 'E',            OPT_EXPAND },
-  { 'L', OPT_LOCALMX },
+  { 'L',            OPT_LOCALMX },
-  { 'N', OPT_NO_NEG },
+  { 'N',            OPT_NO_NEG },
-  { 'D', OPT_NODOTS_LOCAL },
+  { 'D',            OPT_NODOTS_LOCAL },
-  { 'z', OPT_NOWILD },
+  { 'z',            OPT_NOWILD },
-  { 'Z', OPT_ETHERS },
+  { 'Z',            OPT_ETHERS },
-  { 'y', OPT_LOCALISE },
+  { 'y',            OPT_LOCALISE },
-  { '1', OPT_DBUS },
+  { '1',            OPT_DBUS },
-  { '3', OPT_BOOTP_DYNAMIC },
+  { '3',            OPT_BOOTP_DYNAMIC },
-  { '5', OPT_NO_PING },
+  { '5',            OPT_NO_PING },
-  { '9', OPT_LEASE_RO },
+  { '9',            OPT_LEASE_RO },
-  { 'v', 0},
+  { LOPT_RELOAD,    OPT_RELOAD },
-  { 'w', 0},
+  { 'v',            0},
+  { 'w',            0},
   { 0, 0 }
 };
 
@@ -201,6 +207,7 @@ static const struct {
   { "-8, --log-facility=facilty", gettext_noop("Log to this syslog facility. (defaults to DAEMON)"), NULL },
   { "-9, --leasefile-ro", gettext_noop("Read leases at startup, but never write the lease file."), NULL },
   { "-0, --dns-forward-max=<queries>", gettext_noop("Maximum number of concurrent DNS queries. (defaults to %s)"), "!" }, 
+  { "    --clear-on-reload", gettext_noop("Clear DNS cache when reloading %s."), RESOLVFILE },
   { NULL, NULL, NULL }
 }; 
 

src/rfc2131.c

@@ -72,7 +72,7 @@ static void bootp_option_put(struct dhcp_packet *mess,
 			     struct dhcp_boot *boot_opts, struct dhcp_netid *netids);
 static struct in_addr option_addr(unsigned char *opt);
 static unsigned int option_uint(unsigned char *opt, int size);
-static void log_packet(struct daemon *daemon, char *type, struct in_addr *addr, 
+static void log_packet(struct daemon *daemon, char *type, void *addr, 
 		       struct dhcp_packet *mess, char *interface, char *string);
 static unsigned char *option_find(struct dhcp_packet *mess, size_t size, int opt_type, int minsize);
 static unsigned char *option_find1(unsigned char *p, unsigned char *end, int opt, int minsize);
@@ -214,7 +214,7 @@ size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *ifa
   if (mess->giaddr.s_addr || subnet_addr.s_addr || mess->ciaddr.s_addr)
     {
       struct dhcp_context *context_tmp, *context_new = NULL;
-      struct in_addr addr = mess->ciaddr;
+      struct in_addr addr;
       int force = 0;
       
       if (subnet_addr.s_addr)
@@ -227,15 +227,29 @@ size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *ifa
 	  addr = mess->giaddr;
 	  force = 1;
 	}
+      else
+	{
+	  /* If ciaddr is in the hardware derived set of contexts, leave that unchanged */
+	  addr = mess->ciaddr;
+	  for (context_tmp = context; context_tmp; context_tmp = context_tmp->current)
+	    if (context_tmp->netmask.s_addr && 
+		is_same_net(addr, context_tmp->start, context_tmp->netmask) &&
+		is_same_net(addr, context_tmp->end, context_tmp->netmask))
+	      {
+		context_new = context;
+		break;
+	      }
+	} 
 		
-      for (context_tmp = daemon->dhcp; context_tmp; context_tmp = context_tmp->next)
+      if (!context_new)
-	if (context_tmp->netmask.s_addr  && 
+	for (context_tmp = daemon->dhcp; context_tmp; context_tmp = context_tmp->next)
-	    is_same_net(addr, context_tmp->start, context_tmp->netmask) &&
+	  if (context_tmp->netmask.s_addr  && 
-	    is_same_net(addr, context_tmp->end, context_tmp->netmask))
+	      is_same_net(addr, context_tmp->start, context_tmp->netmask) &&
-	  {
+	      is_same_net(addr, context_tmp->end, context_tmp->netmask))
-	    context_tmp->current = context_new;
+	    {
-	    context_new = context_tmp;
+	      context_tmp->current = context_new;
-	  }
+	      context_new = context_tmp;
+	    }
       
       if (context_new || force)
 	context = context_new;
@@ -461,7 +475,10 @@ size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *ifa
      so zero the counts so that we don't get spurious matches between 
      the vendor string and the counts. If the lengths don't add up, we
      assume that the option is a single string and non RFC3004 compliant 
-     and just do the substring match. dhclient provides these broken options. */
+     and just do the substring match. dhclient provides these broken options.
+     The code, later, which sends user-class data to the lease-change script
+     relies on the transformation done here.
+  */
 
   if ((opt = option_find(mess, sz, OPTION_USER_CLASS, 1)))
     {
@@ -552,7 +569,8 @@ size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *ifa
       return 0;
 
     case DHCPRELEASE:
-      if (!(opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER, INADDRSZ)) ||
+      if (!(context = narrow_context(context, mess->ciaddr)) ||
+	  !(opt = option_find(mess, sz, OPTION_SERVER_IDENTIFIER, INADDRSZ)) ||
 	  (context->local.s_addr != option_addr(opt).s_addr))
 	return 0;
       
@@ -613,7 +631,7 @@ size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *ifa
 	    message = _("no address available");      
 	}
       
-      log_packet(daemon, "DISCOVER", opt ? (struct in_addr *)option_ptr(opt) : NULL, mess, iface_name, message); 
+      log_packet(daemon, "DISCOVER", opt ? option_ptr(opt) : NULL, mess, iface_name, message); 
 
       if (message || !(context = narrow_context(context, mess->yiaddr)))
 	return 0;
@@ -743,9 +761,40 @@ size_t dhcp_reply(struct daemon *daemon, struct dhcp_context *context, char *ifa
 	  else if (!clid && mess->hlen == 0)
 	    message = _("no unique-id");
 	  
-	  else if (!lease && 
+	  else if (!lease)
-		   !(lease = lease_allocate(mess->yiaddr)))
+	    {	     
-	    message = _("no leases left");
+	      if (!(lease = lease_allocate(mess->yiaddr)))
+		message = _("no leases left");
+	      else
+		{
+		  /* copy user-class and vendor class into new lease, for the script */
+		  if ((opt = option_find(mess, sz, OPTION_USER_CLASS, 1)))
+		    {
+		      int len = option_len(opt);
+		      unsigned char *ucp = option_ptr(opt);
+		      /* If the user-class option started as counted strings, the first byte will be zero. */
+		      if (len != 0 && ucp[0] == 0)
+			ucp++, len--;
+		      if ((lease->userclass = malloc(len+1)))
+			{
+			  memcpy(lease->userclass, ucp, len);
+			  lease->userclass[len] = 0;
+			  lease->userclass_len = len+1;
+			}
+		    }
+		  if ((opt = option_find(mess, sz, OPTION_VENDOR_ID, 1)))
+		    {
+		      int len = option_len(opt);
+		      unsigned char *ucp = option_ptr(opt);
+		      if ((lease->vendorclass = malloc(len+1)))
+			{
+			  memcpy(lease->vendorclass, ucp, len);
+			  lease->vendorclass[len] = 0;
+			  lease->vendorclass_len = len+1;
+			}
+		    }
+		}  
+	    }
 	}
 
       if (message)
@@ -869,14 +918,20 @@ static unsigned int calc_time(struct dhcp_context *context, struct dhcp_config *
   return time;
 }
 
-static void log_packet(struct daemon *daemon, char *type, struct in_addr *addr, 
+static void log_packet(struct daemon *daemon, char *type, void *addr, 
 		       struct dhcp_packet *mess, char *interface, char *string)
 {
+  struct in_addr a;
+
+  /* addr may be misaligned */
+  if (addr)
+    memcpy(&a, addr, sizeof(a));
+  
   syslog(LOG_INFO, "%s%s(%s) %s%s%s %s",
 	 type ? "DHCP" : "BOOTP",
 	 type ? type : "",
 	 interface, 
-	 addr ? inet_ntoa(*addr) : "",
+	 addr ? inet_ntoa(a) : "",
 	 addr ? " " : "",
 	 print_mac(daemon, mess->chaddr, mess->hlen),
 	 string ? string : "");

src/util.c

@@ -410,3 +410,48 @@ char *print_mac(struct daemon *daemon, unsigned char *mac, int len)
   
   return daemon->namebuff;
 }
+
+void bump_maxfd(int fd, int *max)
+{
+  if (fd > *max)
+    *max = fd;
+}
+
+void log_start(struct daemon *daemon)
+{
+  if (daemon->options & OPT_DEBUG)   
+    {
+#ifdef LOG_PERROR
+      openlog("dnsmasq", LOG_PERROR, daemon->log_fac);
+#else
+      openlog("dnsmasq", 0, daemon->log_fac);
+#endif
+    }
+  else
+    openlog("dnsmasq", LOG_PID, daemon->log_fac);
+}
+
+int read_write(int fd, unsigned char *packet, int size, int rw)
+{
+  ssize_t n, done;
+  
+  for (done = 0; done < size; done += n)
+    {
+    retry:
+      if (rw)
+        n = read(fd, &packet[done], (size_t)(size - done));
+      else
+        n = write(fd, &packet[done], (size_t)(size - done));
+
+      if (n == 0)
+        return 0;
+      else if (n == -1)
+        {
+          if (errno == EINTR || errno == ENOMEM || errno == ENOBUFS)
+            goto retry;
+          else
+            return 0;
+        }
+    }
+  return 1;
+}