dns plugin: Remove unnecessary poll code and use the (blocking) `pcap_loop' function...

Not only does this simplify things *a lot* on *BSD and Mac OS X, because you
can't always call `poll' on their filedescriptors, it also simplifies the code
a lot and thus removes potential error sources.

diff --git a/src/dns.c b/src/dns.c
index b2039a7..cd068fb 100644 (file)
--- a/src/dns.c
+++ b/src/dns.c
@@ -250,7 +250,6 @@ static void *dns_child_loop (void *dummy)
        char    pcap_error[PCAP_ERRBUF_SIZE];
        struct  bpf_program fp;
 
-       struct pollfd poll_fds[1];
        int status;
 
        /* Don't block any signals */
@@ -265,7 +264,7 @@ static void *dns_child_loop (void *dummy)
        pcap_obj = pcap_open_live (pcap_device,
                        PCAP_SNAPLEN,
                        0 /* Not promiscuous */,
-                       0 /* no read timeout */,
+                       atoi (COLLECTD_STEP),
                        pcap_error);
        if (pcap_obj == NULL)
        {
@@ -295,55 +294,18 @@ static void *dns_child_loop (void *dummy)
        dnstop_set_pcap_obj (pcap_obj);
        dnstop_set_callback (dns_child_callback);
 
-       /* Set up poll object */
-       poll_fds[0].fd = pcap_fileno (pcap_obj);
-       poll_fds[0].events = POLLIN | POLLPRI;
-
-       while (42)
-       {
-               DBG ("poll (...)");
-               status = poll (poll_fds, 1, -1 /* wait forever for a change */);
-
-               /* Signals are not caught, but this is very handy when
-                * attaching to the process with a debugger. -octo */
-               if ((status < 0) && (errno == EINTR))
-               {
-                       errno = 0;
-                       continue;
-               }
-
-               if (status < 0)
-               {
-                       syslog (LOG_ERR, "dns plugin: poll(2) failed: %s",
-                                       strerror (errno));
-                       break;
-               }
-
-               if (poll_fds[0].revents & (POLLERR | POLLHUP | POLLNVAL))
-               {
-                       DBG ("pcap-device closed. Exiting.");
-                       syslog (LOG_ERR, "dns plugin: pcap-device closed. Exiting.");
-                       break;
-               }
-               else if (poll_fds[0].revents & (POLLIN | POLLPRI))
-               {
-                       status = pcap_dispatch (pcap_obj,
-                                       10 /* Only handle 10 packets at a time */,
-                                       handle_pcap /* callback */,
-                                       NULL /* Whatever this means.. */);
-                       if (status < 0)
-                       {
-                               DBG ("pcap_dispatch failed: %s", pcap_geterr (pcap_obj));
-                               syslog (LOG_ERR, "dns plugin: pcap_dispatch failed: %s",
-                                               pcap_geterr (pcap_obj));
-                               break;
-                       }
-               }
-       } /* while (42) */
+       status = pcap_loop (pcap_obj,
+                       -1 /* loop forever */,
+                       handle_pcap /* callback */,
+                       NULL /* Whatever this means.. */);
+       if (status < 0)
+               syslog (LOG_ERR, "dns plugin: Listener thread is exiting "
+                               "abnormally: %s", pcap_geterr (pcap_obj));
 
        DBG ("child is exiting");
 
        pcap_close (pcap_obj);
+       listen_thread_init = 0;
        pthread_exit (NULL);
 
        return (NULL);