dnsmasq: backport --tftp-no-fail to ignore missing tftp root

This patch backports the option --tftp-no-fail to dnsmasq and prevents the
service from aborting if the specified TFTP root directory is not available;
this might be the case if TFTP files are located on external media that might
occasionally not be present at startup.

Signed-off-by: Stefan Tomanek <[email protected]>

SVN-Revision: 45213

package/network/services/dnsmasq/files/dnsmasq.init

@@ -128,6 +128,7 @@ dnsmasq() {
 	append_bool "$cfg" boguspriv "--bogus-priv"
 	append_bool "$cfg" expandhosts "--expand-hosts"
 	append_bool "$cfg" enable_tftp "--enable-tftp"
+	append_bool "$cfg" tftp_no_fail "--tftp-no-fail"
 	append_bool "$cfg" nonwildcard "--bind-interfaces"
 	append_bool "$cfg" fqdn "--dhcp-fqdn"
 	append_bool "$cfg" proxydnssec "--proxy-dnssec"

package/network/services/dnsmasq/patches/120-add-tftp-no-fail-to-ignore-missing-tftp-root.patch

@@ -0,0 +1,193 @@
+From 56920681eaf2c5eb08fc75baee4939d15d03b0ea Mon Sep 17 00:00:00 2001
+From: Stefan Tomanek <[email protected]>
+Date: Tue, 31 Mar 2015 22:32:11 +0100
+Subject: [PATCH] add --tftp-no-fail to ignore missing tftp root
+
+(cherry picked from commit 30d0879ed55cb67b1b735beab3d93f3bb3ef1dd2)
+
+Conflicts:
+	CHANGELOG
+	src/dnsmasq.c
+	src/dnsmasq.h
+	src/option.c
+---
+ dnsmasq.conf.example |  3 +++
+ man/dnsmasq.8        |  3 +++
+ src/dnsmasq.c        | 42 +++++++++++++++++++++++++++++++-----------
+ src/dnsmasq.h        |  4 +++-
+ src/option.c         |  3 +++
+ 5 files changed, 43 insertions(+), 12 deletions(-)
+
+diff --git a/dnsmasq.conf.example b/dnsmasq.conf.example
+index 1bd305d..67be99a 100644
+--- a/dnsmasq.conf.example
++++ b/dnsmasq.conf.example
+@@ -486,6 +486,9 @@
+ # Set the root directory for files available via FTP.
+ #tftp-root=/var/ftpd
+ 
++# Do not abort if the tftp-root is unavailable
++#tftp-no-fail
++
+ # Make the TFTP server more secure: with this set, only files owned by
+ # the user dnsmasq is running as will be send over the net.
+ #tftp-secure
+diff --git a/man/dnsmasq.8 b/man/dnsmasq.8
+index 0b8e04f..2ff4b96 100644
+--- a/man/dnsmasq.8
++++ b/man/dnsmasq.8
+@@ -1670,6 +1670,9 @@ Absolute paths (starting with /) are allowed, but they must be within
+ the tftp-root. If the optional interface argument is given, the
+ directory is only used for TFTP requests via that interface.
+ .TP
++.B --tftp-no-fail
++Do not abort startup if specified tftp root directories are inaccessible.
++.TP
+ .B --tftp-unique-root
+ Add the IP address of the TFTP client as a path component on the end
+ of the TFTP-root (in standard dotted-quad format). Only valid if a
+diff --git a/src/dnsmasq.c b/src/dnsmasq.c
+index 5c7750d..b6fa285 100644
+--- a/src/dnsmasq.c
++++ b/src/dnsmasq.c
+@@ -58,6 +58,9 @@ int main (int argc, char **argv)
+   struct dhcp_context *context;
+   struct dhcp_relay *relay;
+ #endif
++#ifdef HAVE_TFTP
++  int tftp_prefix_missing = 0;
++#endif
+ 
+ #ifdef LOCALEDIR
+   setlocale(LC_ALL, "");
+@@ -623,7 +626,7 @@ int main (int argc, char **argv)
+ #endif
+ 
+ #ifdef HAVE_TFTP
+-      if (option_bool(OPT_TFTP))
++  if (option_bool(OPT_TFTP))
+     {
+       DIR *dir;
+       struct tftp_prefix *p;
+@@ -632,24 +635,33 @@ int main (int argc, char **argv)
+ 	{
+ 	  if (!((dir = opendir(daemon->tftp_prefix))))
+ 	    {
+-	      send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix);
+-	      _exit(0);
++	      tftp_prefix_missing = 1;
++	      if (!option_bool(OPT_TFTP_NO_FAIL))
++	        {
++	          send_event(err_pipe[1], EVENT_TFTP_ERR, errno, daemon->tftp_prefix);
++	          _exit(0);
++	        }
+ 	    }
+ 	  closedir(dir);
+ 	}
+-
++      
+       for (p = daemon->if_prefix; p; p = p->next)
+ 	{
++	  p->missing = 0;
+ 	  if (!((dir = opendir(p->prefix))))
+-	   {
+-	     send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix);
+-	     _exit(0);
+-	   } 
++	    {
++	      p->missing = 1;
++	      if (!option_bool(OPT_TFTP_NO_FAIL))
++		{
++		  send_event(err_pipe[1], EVENT_TFTP_ERR, errno, p->prefix);
++		  _exit(0);
++		}
++	    } 
+ 	  closedir(dir);
+ 	}
+     }
+ #endif
+-
++  
+   if (daemon->port == 0)
+     my_syslog(LOG_INFO, _("started, version %s DNS disabled"), VERSION);
+   else if (daemon->cachesize != 0)
+@@ -743,8 +755,9 @@ int main (int argc, char **argv)
+ #endif
+ 
+ #ifdef HAVE_TFTP
+-	if (option_bool(OPT_TFTP))
+-    {
++  if (option_bool(OPT_TFTP))
++    { 
++      struct tftp_prefix *p;
+ #ifdef FD_SETSIZE
+       if (FD_SETSIZE < (unsigned)max_fd)
+ 	max_fd = FD_SETSIZE;
+@@ -754,7 +767,14 @@ int main (int argc, char **argv)
+ 		daemon->tftp_prefix ? _("root is ") : _("enabled"),
+ 		daemon->tftp_prefix ? daemon->tftp_prefix: "",
+ 		option_bool(OPT_TFTP_SECURE) ? _("secure mode") : "");
++       
++      if (tftp_prefix_missing)
++	my_syslog(MS_TFTP | LOG_WARNING, _("warning: %s inaccessible"), daemon->tftp_prefix);
+       
++      for (p = daemon->if_prefix; p; p = p->next)
++	if (p->missing)
++	   my_syslog(MS_TFTP | LOG_WARNING, _("warning: TFTP directory %s inaccessible"), p->prefix);
++
+       /* This is a guess, it assumes that for small limits, 
+ 	 disjoint files might be served, but for large limits, 
+ 	 a single file will be sent to may clients (the file only needs
+diff --git a/src/dnsmasq.h b/src/dnsmasq.h
+index 1dd61c5..086cb67 100644
+--- a/src/dnsmasq.h
++++ b/src/dnsmasq.h
+@@ -238,7 +238,8 @@ struct event_desc {
+ #define OPT_DNSSEC_NO_SIGN 48 
+ #define OPT_LOCAL_SERVICE  49
+ #define OPT_LOOP_DETECT    50
+-#define OPT_LAST           51
++#define OPT_TFTP_NO_FAIL   51
++#define OPT_LAST           52
+ 
+ /* extra flags for my_syslog, we use a couple of facilities since they are known 
+    not to occupy the same bits as priorities, no matter how syslog.h is set up. */
+@@ -888,6 +889,7 @@ struct addr_list {
+ struct tftp_prefix {
+   char *interface;
+   char *prefix;
++  int missing;
+   struct tftp_prefix *next;
+ };
+ 
+diff --git a/src/option.c b/src/option.c
+index 209fa69..fa5e4d3 100644
+--- a/src/option.c
++++ b/src/option.c
+@@ -147,6 +147,7 @@ struct myoption {
+ #define LOPT_LOCAL_SERVICE 335
+ #define LOPT_DNSSEC_TIME   336
+ #define LOPT_LOOP_DETECT   337
++#define LOPT_TFTP_NO_FAIL  338
+ 
+ #ifdef HAVE_GETOPT_LONG
+ static const struct option opts[] =  
+@@ -227,6 +228,7 @@ static const struct myoption opts[] =
+     { "dhcp-ignore-names", 2, 0, LOPT_NO_NAMES },
+     { "enable-tftp", 2, 0, LOPT_TFTP },
+     { "tftp-secure", 0, 0, LOPT_SECURE },
++    { "tftp-no-fail", 0, 0, LOPT_TFTP_NO_FAIL },
+     { "tftp-unique-root", 0, 0, LOPT_APREF },
+     { "tftp-root", 1, 0, LOPT_PREFIX },
+     { "tftp-max", 1, 0, LOPT_TFTP_MAX },
+@@ -402,6 +404,7 @@ static struct {
+   { LOPT_PREFIX, ARG_DUP, "<dir>[,<iface>]", gettext_noop("Export files by TFTP only from the specified subtree."), NULL },
+   { LOPT_APREF, OPT_TFTP_APREF, NULL, gettext_noop("Add client IP address to tftp-root."), NULL },
+   { LOPT_SECURE, OPT_TFTP_SECURE, NULL, gettext_noop("Allow access only to files owned by the user running dnsmasq."), NULL },
++  { LOPT_TFTP_NO_FAIL, OPT_TFTP_NO_FAIL, NULL, gettext_noop("Do not terminate the service if TFTP directories are inaccessible."), NULL },
+   { LOPT_TFTP_MAX, ARG_ONE, "<integer>", gettext_noop("Maximum number of conncurrent TFTP transfers (defaults to %s)."), "#" },
+   { LOPT_NOBLOCK, OPT_TFTP_NOBLOCK, NULL, gettext_noop("Disable the TFTP blocksize extension."), NULL },
+   { LOPT_TFTP_LC, OPT_TFTP_LC, NULL, gettext_noop("Convert TFTP filenames to lowercase"), NULL },
+-- 
+2.1.4
+