activate fanout only after socker is properly binded

pcap-linux.c

@@ -211,6 +211,7 @@ static void map_arphrd_to_dlt(pcap_t *, int, const char *, int);
 static int pcap_activate_linux(pcap_t *);
 static int activate_pf_packet(pcap_t *, int);
 static int setup_mmapped(pcap_t *, int *);
+static int activate_fanout(pcap_t *);
 static int pcap_can_set_rfmon_linux(pcap_t *);
 static int pcap_inject_linux(pcap_t *, const void *, int);
 static int pcap_stats_linux(pcap_t *, struct pcap_stat *);
@@ -1063,6 +1064,16 @@ pcap_activate_linux(pcap_t *handle)
  goto fail;
  }
 
+ /*
+ * Only after we have the socket properly binded and set with the
+ * correct protocol we can set the FANOUT mode.
+ */
+ if ((status2 = activate_fanout(handle)) != 0) {
+ status = status2;
+ goto fail;
+ }
+
+
  handle->inject_op = pcap_inject_linux;
  handle->setfilter_op = pcap_setfilter_linux;
  handle->setdirection_op = pcap_setdirection_linux;
@@ -2268,7 +2279,7 @@ activate_pf_packet(pcap_t *handle, int is_any_device)
  const char *device = handle->opt.device;
  int status = 0;
  int sock_fd, arptype;
-#if defined(HAVE_PACKET_AUXDATA) || defined(PACKET_FANOUT)
+#if defined(HAVE_PACKET_AUXDATA)
  int val = 0;
 #endif
  int err = 0;
@@ -2539,21 +2550,6 @@ activate_pf_packet(pcap_t *handle, int is_any_device)
  }
  }
 
- /*
- * Add the packet socket into FANOUT group, if needed.
- */
-#ifdef PACKET_FANOUT
- if (handle->opt.fanout_enabled) {
- val = handle->opt.fanout_opt;
- if (setsockopt(sock_fd, SOL_PACKET, PACKET_FANOUT,
- &val, sizeof(val)) < 0) {
- pcap_fmt_errmsg_for_errno(handle->errbuf,
- PCAP_ERRBUF_SIZE, errno, "setsockopt (PACKET_FANOUT)");
- return -1;
- }
- }
-#endif /* PACKET_FANOUT */
-
  /* Enable auxiliary data if supported and reserve room for
  * reconstructing VLAN headers. */
 #ifdef HAVE_PACKET_AUXDATA
@@ -2646,6 +2642,30 @@ activate_pf_packet(pcap_t *handle, int is_any_device)
  return status;
 }
 
+/*
+ * Add the packet socket into FANOUT group, if needed.
+ *
+ * On success (or if nothing was done), returns 0.
+ *
+ * On error, returns -1 and sets handle->errbuf to the appropriate message.
+ */
+static int
+activate_fanout(pcap_t *handle) {
+ int rc = 0;
+#ifdef PACKET_FANOUT
+ int val = handle->opt.fanout_opt;
+
+ if (handle->opt.fanout_enabled &&
+ setsockopt(handle->fd, SOL_PACKET, PACKET_FANOUT, &val, sizeof(val)) < 0) {
+ pcap_fmt_errmsg_for_errno(handle->errbuf, PCAP_ERRBUF_SIZE, errno, "setsockopt (PACKET_FANOUT)");
+ rc = -1;
+ }
+#endif /* PACKET_FANOUT */
+
+ return rc;
+}
+
+
 /*
  * Attempt to setup memory-mapped access.
  *