cups/cups-resolv_reload.patch

diff -up cups-2.1.4/cups/auth.c.resolv_reload cups-2.1.4/cups/auth.c
--- cups-2.1.4/cups/auth.c.resolv_reload	2016-06-14 19:45:32.000000000 +0200
+++ cups-2.1.4/cups/auth.c	2017-03-30 09:27:13.481181830 +0200
@@ -522,6 +522,16 @@ cups_gss_getname(
   DEBUG_printf(("7cups_gss_getname(http=%p, service_name=\"%s\")", http,
                 service_name));
 
+#ifdef HAVE_RES_INIT
+ /*
+  * Check if /etc/resolv.conf is modified.
+  * If so, reload resolver.
+  */
+
+  http_resolv_check_t status;
+
+  status = httpCheckResolv();
+#endif /* HAVE_RES_INIT */
 
  /*
   * Get the hostname...
diff -up cups-2.1.4/cups/http-addr.c.resolv_reload cups-2.1.4/cups/http-addr.c
--- cups-2.1.4/cups/http-addr.c.resolv_reload	2017-03-30 09:27:13.452182143 +0200
+++ cups-2.1.4/cups/http-addr.c	2017-03-30 09:27:13.482181819 +0200
@@ -364,6 +364,17 @@ httpAddrLookup(
 
 #ifdef HAVE_RES_INIT
  /*
+  * Check if /etc/resolv.conf is modified.
+  * If so, reload resolver and set need_res_init to 0.
+  */
+
+  http_resolv_check_t status;
+
+  status = httpCheckResolv();
+
+  if (status == HTTP_RESOLV_CHECK_RELOADED && cg->need_res_init == 1)
+    cg->need_res_init = 0;
+ /*
   * STR #2920: Initialize resolver after failure in cups-polld
   *
   * If the previous lookup failed, re-initialize the resolver to prevent
diff -up cups-2.1.4/cups/http-addrlist.c.resolv_reload cups-2.1.4/cups/http-addrlist.c
--- cups-2.1.4/cups/http-addrlist.c.resolv_reload	2017-03-30 09:27:13.419182500 +0200
+++ cups-2.1.4/cups/http-addrlist.c	2017-03-30 09:27:13.482181819 +0200
@@ -414,6 +414,17 @@ httpAddrGetList(const char *hostname,	/*
 
 #ifdef HAVE_RES_INIT
  /*
+  * Check if /etc/resolv.conf is modified.
+  * If so, reload resolver and set cg->need_res_init to 0
+  */
+
+  http_resolv_check_t status;
+
+  status = httpCheckResolv();
+
+  if (status == HTTP_RESOLV_CHECK_RELOADED && cg->need_res_init == 1)
+    cg->need_res_init = 0;
+ /*
   * STR #2920: Initialize resolver after failure in cups-polld
   *
   * If the previous lookup failed, re-initialize the resolver to prevent
diff -up cups-2.1.4/cups/http.c.resolv_reload cups-2.1.4/cups/http.c
--- cups-2.1.4/cups/http.c.resolv_reload	2017-03-30 09:27:13.484181798 +0200
+++ cups-2.1.4/cups/http.c	2017-03-30 09:34:19.393276147 +0200
@@ -109,6 +109,9 @@ static const char * const http_fields[]
 			  "Allow",
 			  "Server"
 			};
+#ifdef HAVE_RES_INIT
+time_t resolv_conf_modtime = 0;
+#endif /* HAVE_RES_INIT */
 
 
 /*
@@ -4848,6 +4851,35 @@ http_write_chunk(http_t     *http,	/* I
   return (bytes);
 }
 
+#ifdef HAVE_RES_INIT
+/*
+ * Function to check modification time of resolv.conf. 
+ * If time is changed, it reloads resolver.
+ */
+
+http_resolv_check_t
+httpCheckResolv()
+{
+  http_resolv_check_t status = HTTP_RESOLV_CHECK_OK;
+  struct stat resolv_conf_status;
+
+  status = stat(HTTP_RESOLV_CONF_PATH, &resolv_conf_status);
+
+  if (status == HTTP_RESOLV_CHECK_ERROR)
+    return (status);
+
+  if (resolv_conf_modtime != 0 && resolv_conf_status.st_mtime != resolv_conf_modtime)
+  {
+    res_init();
+
+    status = HTTP_RESOLV_CHECK_RELOADED;
+  }
+
+  resolv_conf_modtime = resolv_conf_status.st_mtime;
+
+  return (status);
+}
+#endif /* HAVE_RES_INIT */
 
 /*
  * End of "$Id: http.c 12970 2015-11-13 20:02:51Z msweet $".
diff -up cups-2.1.4/cups/http.h.resolv_reload cups-2.1.4/cups/http.h
--- cups-2.1.4/cups/http.h.resolv_reload	2016-06-14 19:45:32.000000000 +0200
+++ cups-2.1.4/cups/http.h	2017-03-30 10:05:09.679859230 +0200
@@ -57,6 +57,12 @@ typedef off_t ssize_t;			/* @private@ */
 #      define SO_PEERCRED LOCAL_PEERCRED
 #    endif /* LOCAL_PEERCRED && !SO_PEERCRED */
 #  endif /* WIN32 */
+#  ifdef HAVE_RES_INIT
+#    include <sys/stat.h>
+#    include <unistd.h>
+#    include <arpa/nameser.h>
+#    include <resolv.h>
+#  endif /* HAVE_RES_INIT */
 
 
 /*
@@ -97,6 +103,13 @@ extern "C" {
 #endif /* AF_INET6 && !s6_addr32 */
 
 
+#ifdef HAVE_RES_INIT
+/*
+ * Global variable for storing old modification time of resolv.conf 
+ */
+  extern time_t resolv_conf_modtime;
+#endif /* HAVE_RES_INIT */
+
 /*
  * Limits...
  */
@@ -105,6 +118,9 @@ extern "C" {
 #  define HTTP_MAX_HOST		256	/* Max length of hostname string */
 #  define HTTP_MAX_BUFFER	2048	/* Max length of data buffer */
 #  define HTTP_MAX_VALUE	256	/* Max header field value length */
+#  ifdef HAVE_RES_INIT
+#    define HTTP_RESOLV_CONF_PATH	"/etc/resolv.conf" /* Path to resolv.conf */
+#  endif /* HAVE_RES_INIT */
 
 
 /*
@@ -408,6 +424,15 @@ typedef enum http_version_e		/**** HTTP
 #  endif /* !_CUPS_NO_DEPRECATED */
 } http_version_t;
 
+#ifdef HAVE_RES_INIT
+typedef enum http_resolv_check_e
+{
+  HTTP_RESOLV_CHECK_ERROR = -1,
+  HTTP_RESOLV_CHECK_OK = 0,
+  HTTP_RESOLV_CHECK_RELOADED = 1
+} http_resolv_check_t;
+#endif /* HAVE_RES_INIT */
+
 typedef union _http_addr_u		/**** Socket address union, which
 					 **** makes using IPv6 and other
 					 **** address types easier and
@@ -646,6 +671,11 @@ extern void		httpShutdown(http_t *http)
 extern const char	*httpStateString(http_state_t state) _CUPS_API_2_0;
 extern const char	*httpURIStatusString(http_uri_status_t status) _CUPS_API_2_0;
 
+/**** Prototype of function to check modification time of /etc/resolv.conf ****/
+#ifdef HAVE_RES_INIT
+extern http_resolv_check_t	httpCheckResolv();
+#endif /* HAVE_RES_INIT */
+
 /*
  * C++ magic...
  */
diff -up cups-2.1.4/cups/http-support.c.resolv_reload cups-2.1.4/cups/http-support.c
--- cups-2.1.4/cups/http-support.c.resolv_reload	2017-03-30 09:27:13.445182219 +0200
+++ cups-2.1.4/cups/http-support.c	2017-03-30 09:27:13.486181776 +0200
@@ -2266,6 +2266,16 @@ http_resolve_cb(
     http_addrlist_t	*addrlist,	/* List of addresses */
 			*addr;		/* Current address */
 
+#ifdef HAVE_RES_INIT
+   /*
+	* Check if resolv.conf is modified, if so, reload resolver
+	*/
+
+    http_resolv_check_t status;
+
+	status = httpCheckResolv();
+#endif /* HAVE_RES_INIT */
+
     DEBUG_printf(("8http_resolve_cb: Looking up \"%s\".", hostTarget));
 
     snprintf(fqdn, sizeof(fqdn), "%d", ntohs(port));
diff -up cups-2.1.4/scheduler/conf.c.resolv_reload cups-2.1.4/scheduler/conf.c
--- cups-2.1.4/scheduler/conf.c.resolv_reload	2017-03-30 09:27:13.478181863 +0200
+++ cups-2.1.4/scheduler/conf.c	2017-03-30 09:27:13.487181765 +0200
@@ -939,6 +939,12 @@ cupsdReadConfiguration(void)
   if (!RemotePort)
     BrowseLocalProtocols = 0;		/* Disable sharing - no remote access */
 
+#ifdef HAVE_RES_INIT
+  http_resolv_check_t res_status;	/* Return status of httpCheckResolv() */
+
+  res_status = httpCheckResolv();
+#endif /* HAVE_RES_INIT */
+
  /*
   * See if the ServerName is an IP address...
   */
diff -up cups-2.1.4/scheduler/main.c.resolv_reload cups-2.1.4/scheduler/main.c
--- cups-2.1.4/scheduler/main.c.resolv_reload	2017-03-30 09:27:13.464182014 +0200
+++ cups-2.1.4/scheduler/main.c	2017-03-30 09:27:13.488181755 +0200
@@ -141,6 +141,17 @@ main(int  argc,				/* I - Number of comm
 #endif /* HAVE_AVAHI */
 
 
+#ifdef HAVE_RES_INIT
+  http_resolv_check_t status;	/* Return status from httpCheckResolv() */
+
+  status = httpCheckResolv();
+  if (status == HTTP_RESOLV_CHECK_ERROR)
+  {
+    fputs("cupsd: Cannot get a status of /etc/resolv.conf\n", stderr);
+	return (1);
+  }
+#endif /* HAVE_RES_INIT */
+
 #ifdef HAVE_GETEUID
  /*
   * Check for setuid invocation, which we do not support!