[Linux] add new function linux_check_direction()

We're right now have the same code in two places, split it into new inline
function: linux_check_direction()

Merged-with-my-pcap_t-changes-by: Guy Harris <[email protected]>

diff --git a/pcap-linux.c b/pcap-linux.c
index e49af804be85e1aadfae662a12c2a237631471dd..9fe97f30981018926c5e5b3776967a2727512aae 100644 (file)
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -1377,6 +1377,42 @@ pcap_set_datalink_linux(pcap_t *handle, int dlt)
        return 0;
 }
 
+/*
+ * linux_check_direction()
+ *
+ * Do checks based on packet direction.
+ */
+static inline int
+linux_check_direction(const pcap_t *handle, const struct sockaddr_ll *sll)
+{
+       struct pcap_linux       *handlep = handle->private;
+
+       if (sll->sll_pkttype == PACKET_OUTGOING) {
+               /*
+                * Outgoing packet.
+                * If this is from the loopback device, reject it;
+                * we'll see the packet as an incoming packet as well,
+                * and we don't want to see it twice.
+                */
+               if (sll->sll_ifindex == handlep->lo_ifindex)
+                       return 0;
+
+               /*
+                * If the user only wants incoming packets, reject it.
+                */
+               if (handle->direction == PCAP_D_IN)
+                       return 0;
+       } else {
+               /*
+                * Incoming packet.
+                * If the user only wants outgoing packets, reject it.
+                */
+               if (handle->direction == PCAP_D_OUT)
+                       return 0;
+       }
+       return 1;
+}
+
 /*
  *  Read a packet from the socket calling the handler provided by
  *  the user. Returns the number of packets received or -1 if an
@@ -1531,29 +1567,8 @@ pcap_read_packet(pcap_t *handle, pcap_handler callback, u_char *userdata)
                 * address returned for SOCK_PACKET is a "sockaddr_pkt"
                 * which lacks the relevant packet type information.
                 */
-               if (from.sll_pkttype == PACKET_OUTGOING) {
-                       /*
-                        * Outgoing packet.
-                        * If this is from the loopback device, reject it;
-                        * we'll see the packet as an incoming packet as well,
-                        * and we don't want to see it twice.
-                        */
-                       if (from.sll_ifindex == handlep->lo_ifindex)
-                               return 0;
-
-                       /*
-                        * If the user only wants incoming packets, reject it.
-                        */
-                       if (handle->direction == PCAP_D_IN)
-                               return 0;
-               } else {
-                       /*
-                        * Incoming packet.
-                        * If the user only wants outgoing packets, reject it.
-                        */
-                       if (handle->direction == PCAP_D_OUT)
-                               return 0;
-               }
+               if (!linux_check_direction(handle, &from))
+                       return 0;
        }
 #endif
 
@@ -4000,33 +4015,9 @@ pcap_read_linux_mmap(pcap_t *handle, int max_packets, pcap_handler callback,
                                        tp_len, tp_snaplen) == 0))
                        goto skip;
 
-               /*
-                * Do checks based on packet direction.
-                */
                sll = (void *)h.raw + TPACKET_ALIGN(handlep->tp_hdrlen);
-               if (sll->sll_pkttype == PACKET_OUTGOING) {
-                       /*
-                        * Outgoing packet.
-                        * If this is from the loopback device, reject it;
-                        * we'll see the packet as an incoming packet as well,
-                        * and we don't want to see it twice.
-                        */
-                       if (sll->sll_ifindex == handlep->lo_ifindex)
-                               goto skip;
-
-                       /*
-                        * If the user only wants incoming packets, reject it.
-                        */
-                       if (handle->direction == PCAP_D_IN)
-                               goto skip;
-               } else {
-                       /*
-                        * Incoming packet.
-                        * If the user only wants outgoing packets, reject it.
-                        */
-                       if (handle->direction == PCAP_D_OUT)
-                               goto skip;
-               }
+               if (!linux_check_direction(handle, sll))
+                       goto skip;
 
                /* get required packet info from ring header */
                pcaphdr.ts.tv_sec = tp_sec;