dnsmasq: follow upstream dnsmasq pre-v2.81 v2

Backport upstream commits.  Most interesting 122392e which changes how
SERVFAIL is handled especially in event of genuine server down/failure
scenarios with multiple servers.  a799ca0 also interesting in that
answered received via TCP are now cached, DNSSEC typically using TCP
meant until now answers weren't cached, hence reducing performance.

59e4703 Free config file values on parsing errors.
48d12f1 Remove the NO_FORK compile-time option, and support for uclinux.
122392e Revert 68f6312d4bae30b78daafcd6f51dc441b8685b1e
3a5a84c Fix Makefile lines generating UBUS linker config.
24b8760 Do not rely on dead code elimination, use array instead. Make options bits derived from size and count. Use size of option bits and last supported bit in computation. No new change would be required when new options are added. Just change OPT_LAST constant.
6f7812d Fix spurious AD flags in some DNS replies from local config.
cbb5b17 Fix logging in cf5984367bc6a949e3803a576512c5a7bc48ebab
cf59843 Don't forward *.bind/*.server queries upstream
ee87504 Remove ability to compile without IPv6 support.
a220545 Ensure that AD bit is reset on answers from --address=/<domain>/<address>.
a799ca0 Impove cache behaviour for TCP connections.

Along with an additional patch to fix compilation without DHCPv6, sent
upstream.

I've been running this for aaaages without obvious issue hence brave
step of opening to wider openwrt community.

Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>

1 files changed, 199 insertions, 0 deletions

diff --git a/package/network/services/dnsmasq/patches/0010-Remove-the-NO_FORK-compile-time-option-and-support-f.patch b/package/network/services/dnsmasq/patches/0010-Remove-the-NO_FORK-compile-time-option-and-support-f.patch
new file mode 100644
index 0000000000..1110d4c5fa
--- /dev/null
+++ b/package/network/services/dnsmasq/patches/0010-Remove-the-NO_FORK-compile-time-option-and-support-f.patch
@@ -0,0 +1,199 @@
+From 48d12f14c9c0fc8cf943b52774c3892517dd72d4 Mon Sep 17 00:00:00 2001
+From: Simon Kelley <simon@thekelleys.org.uk>
+Date: Fri, 2 Nov 2018 21:55:04 +0000
+Subject: [PATCH 10/11] Remove the NO_FORK compile-time option, and support for
+ uclinux.
+
+In an era where everything has an MMU, this looks like
+an anachronism, and it adds to (Ok, multiplies!) the
+combinatorial explosion of compile-time options.
+
+Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk>
+---
+ CHANGELOG     |  6 ++++++
+ src/config.h  | 21 ++-------------------
+ src/dnsmasq.c | 14 --------------
+ src/option.c  |  4 +---
+ 4 files changed, 9 insertions(+), 36 deletions(-)
+
+--- a/CHANGELOG
++++ b/CHANGELOG
+@@ -11,6 +11,12 @@ version 2.81
+ 	This fix passes cache entries back from the TCP child process to
+ 	the main server process, and fixes the problem.
+ 
++	Remove the NO_FORK compile-time option, and support for uclinux.
++	In an era where everything has an MMU, this looks like
++	an anachronism, and it adds to (Ok, multiplies!) the
++	combinatorial explosion of compile-time options. Thanks to
++	Kevin Darbyshire-Bryant for the patch.
++
+ 
+ version 2.80
+ 	Add support for RFC 4039 DHCP rapid commit. Thanks to Ashram Method
+--- a/src/config.h
++++ b/src/config.h
+@@ -239,27 +239,13 @@ HAVE_SOCKADDR_SA_LEN
+    defined if struct sockaddr has sa_len field (*BSD) 
+ */
+ 
+-/* Must precede __linux__ since uClinux defines __linux__ too. */
+-#if defined(__uClinux__)
+-#define HAVE_LINUX_NETWORK
+-#define HAVE_GETOPT_LONG
+-#undef HAVE_SOCKADDR_SA_LEN
+-/* Never use fork() on uClinux. Note that this is subtly different from the
+-   --keep-in-foreground option, since it also  suppresses forking new 
+-   processes for TCP connections and disables the call-a-script on leasechange
+-   system. It's intended for use on MMU-less kernels. */
+-#define NO_FORK
+-
+-#elif defined(__UCLIBC__)
++#if defined(__UCLIBC__)
+ #define HAVE_LINUX_NETWORK
+ #if defined(__UCLIBC_HAS_GNU_GETOPT__) || \
+    ((__UCLIBC_MAJOR__==0) && (__UCLIBC_MINOR__==9) && (__UCLIBC_SUBLEVEL__<21))
+ #    define HAVE_GETOPT_LONG
+ #endif
+ #undef HAVE_SOCKADDR_SA_LEN
+-#if !defined(__ARCH_HAS_MMU__) && !defined(__UCLIBC_HAS_MMU__)
+-#  define NO_FORK
+-#endif
+ #if defined(__UCLIBC_HAS_IPV6__)
+ #  ifndef IPV6_V6ONLY
+ #    define IPV6_V6ONLY 26
+@@ -328,7 +314,7 @@ HAVE_SOCKADDR_SA_LEN
+ #define HAVE_DHCP
+ #endif
+ 
+-#if defined(NO_SCRIPT) || defined(NO_FORK)
++#if defined(NO_SCRIPT)
+ #undef HAVE_SCRIPT
+ #undef HAVE_LUASCRIPT
+ #endif
+@@ -372,9 +358,6 @@ static char *compile_opts =
+ #ifdef HAVE_BROKEN_RTC
+ "no-RTC "
+ #endif
+-#ifdef NO_FORK
+-"no-MMU "
+-#endif
+ #ifndef HAVE_DBUS
+ "no-"
+ #endif
+--- a/src/dnsmasq.c
++++ b/src/dnsmasq.c
+@@ -485,7 +485,6 @@ int main (int argc, char **argv)
+       if (chdir("/") != 0)
+ 	die(_("cannot chdir to filesystem root: %s"), NULL, EC_MISC); 
+ 
+-#ifndef NO_FORK      
+       if (!option_bool(OPT_NO_FORK))
+ 	{
+ 	  pid_t pid;
+@@ -525,7 +524,6 @@ int main (int argc, char **argv)
+ 	  if (pid != 0)
+ 	    _exit(0);
+ 	}
+-#endif
+             
+       /* write pidfile _after_ forking ! */
+       if (daemon->runfile)
+@@ -1628,12 +1626,10 @@ static int set_dns_listeners(time_t now)
+ 
+     }
+   
+-#ifndef NO_FORK
+   if (!option_bool(OPT_DEBUG))
+     for (i = 0; i < MAX_PROCS; i++)
+       if (daemon->tcp_pipes[i] != -1)
+ 	poll_listen(daemon->tcp_pipes[i], POLLIN);
+-#endif
+   
+   return wait;
+ }
+@@ -1643,9 +1639,7 @@ static void check_dns_listeners(time_t n
+   struct serverfd *serverfdp;
+   struct listener *listener;
+   int i;
+-#ifndef NO_FORK
+   int pipefd[2];
+-#endif
+   
+   for (serverfdp = daemon->sfds; serverfdp; serverfdp = serverfdp->next)
+     if (poll_check(serverfdp->fd, POLLIN))
+@@ -1657,7 +1651,6 @@ static void check_dns_listeners(time_t n
+ 	  poll_check(daemon->randomsocks[i].fd, POLLIN))
+ 	reply_query(daemon->randomsocks[i].fd, daemon->randomsocks[i].family, now);
+ 
+-#ifndef NO_FORK
+   /* Races. The child process can die before we read all of the data from the
+      pipe, or vice versa. Therefore send tcp_pids to zero when we wait() the 
+      process, and tcp_pipes to -1 and close the FD when we read the last
+@@ -1674,7 +1667,6 @@ static void check_dns_listeners(time_t n
+ 	  close(daemon->tcp_pipes[i]);
+ 	  daemon->tcp_pipes[i] = -1;	
+ 	}
+-#endif
+ 	
+   for (listener = daemon->listeners; listener; listener = listener->next)
+     {
+@@ -1768,7 +1760,6 @@ static void check_dns_listeners(time_t n
+ 	      shutdown(confd, SHUT_RDWR);
+ 	      while (retry_send(close(confd)));
+ 	    }
+-#ifndef NO_FORK
+ 	  else if (!option_bool(OPT_DEBUG) && pipe(pipefd) == 0 && (p = fork()) != 0)
+ 	    {
+ 	      close(pipefd[1]); /* parent needs read pipe end. */
+@@ -1791,7 +1782,6 @@ static void check_dns_listeners(time_t n
+ 	      /* The child can use up to TCP_MAX_QUERIES ids, so skip that many. */
+ 	      daemon->log_id += TCP_MAX_QUERIES;
+ 	    }
+-#endif
+ 	  else
+ 	    {
+ 	      unsigned char *buff;
+@@ -1811,7 +1801,6 @@ static void check_dns_listeners(time_t n
+ 		  auth_dns = 0;
+ 		}
+ 
+-#ifndef NO_FORK
+ 	      /* Arrange for SIGALRM after CHILD_LIFETIME seconds to
+ 		 terminate the process. */
+ 	      if (!option_bool(OPT_DEBUG))
+@@ -1820,7 +1809,6 @@ static void check_dns_listeners(time_t n
+ 		  close(pipefd[0]); /* close read end in child. */
+ 		  daemon->pipe_to_parent = pipefd[1];
+ 		}
+-#endif
+ 
+ 	      /* start with no upstream connections. */
+ 	      for (s = daemon->servers; s; s = s->next)
+@@ -1846,13 +1834,11 @@ static void check_dns_listeners(time_t n
+ 		    shutdown(s->tcpfd, SHUT_RDWR);
+ 		    while (retry_send(close(s->tcpfd)));
+ 		  }
+-#ifndef NO_FORK		   
+ 	      if (!option_bool(OPT_DEBUG))
+ 		{
+ 		  flush_log();
+ 		  _exit(0);
+ 		}
+-#endif
+ 	    }
+ 	}
+     }
+--- a/src/option.c
++++ b/src/option.c
+@@ -1828,9 +1828,7 @@ static int one_opt(int option, char *arg
+       /* Sorry about the gross pre-processor abuse */
+     case '6':             /* --dhcp-script */
+     case LOPT_LUASCRIPT:  /* --dhcp-luascript */
+-#  if defined(NO_FORK)
+-      ret_err(_("cannot run scripts under uClinux"));
+-#  elif !defined(HAVE_SCRIPT)
++#  if !defined(HAVE_SCRIPT)
+       ret_err(_("recompile with HAVE_SCRIPT defined to enable lease-change scripts"));
+ #  else
+       if (option == LOPT_LUASCRIPT)