abrtd: call res_init() if /etc/resolv.conf or friends were changed

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/src/Daemon/Daemon.cpp b/src/Daemon/Daemon.cpp
index af4f9dc..175efe9 100644
--- a/src/Daemon/Daemon.cpp
+++ b/src/Daemon/Daemon.cpp
@@ -19,6 +19,7 @@
 
 #include <syslog.h>
 #include <pthread.h>
+#include <resolv.h> /* res_init */
 #include <string>
 #include <limits.h>
 #include <sys/inotify.h>
@@ -594,6 +595,8 @@ static gboolean handle_inotify_cb(GIOChannel *gio, GIOCondition condition, gpoin
 static void run_main_loop(GMainLoop* loop)
 {
     GMainContext *context = g_main_loop_get_context(loop);
+    time_t old_time = 0;
+    time_t dns_conf_hash = 0;
 
     while (!s_exiting)
     {
@@ -618,6 +621,33 @@ static void run_main_loop(GMainLoop* loop)
         if (s_timeout)
             alarm(0);
 
+        /* res_init() makes glibc reread /etc/resolv.conf.
+         * I'd think libc should be clever enough to do it itself
+         * at every name resolution attempt, but no...
+         * We need to guess ourself whether we want to do it.
+         */
+        time_t now = time(NULL) >> 2;
+        if (old_time != now) /* check once in 4 seconds */
+        {
+            old_time = now;
+
+            time_t hash = 0;
+            struct stat sb;
+            if (stat("/etc/resolv.conf", &sb) == 0)
+                hash = sb.st_mtime;
+            if (stat("/etc/host.conf", &sb) == 0)
+                hash += sb.st_mtime;
+            if (stat("/etc/hosts", &sb) == 0)
+                hash += sb.st_mtime;
+            if (stat("/etc/nsswitch.conf", &sb) == 0)
+                hash += sb.st_mtime;
+            if (dns_conf_hash != hash)
+            {
+                dns_conf_hash = hash;
+                res_init();
+            }
+        }
+
         some_ready = g_main_context_check(context, max_priority, fds, nfds);
         if (some_ready)
             g_main_context_dispatch(context);