Require a live capture for all Linux BPF extensions.

[libpcap] / pcap-linux.c

diff --git a/pcap-linux.c b/pcap-linux.c
index ac7e668aad0235977d44d009aa39ebcd32635a2c..8fca8b60b484671b68b65d2032886ad345b21450 100644 (file)
--- a/pcap-linux.c
+++ b/pcap-linux.c
@@ -2762,7 +2762,7 @@ setup_socket(pcap_t *handle, int is_any_device)
         */
        handle->fd = sock_fd;
 
-#if defined(SO_BPF_EXTENSIONS) && defined(SKF_AD_VLAN_TAG_PRESENT)
+#ifdef SO_BPF_EXTENSIONS
        /*
         * Can we generate special code for VLAN checks?
         * (XXX - what if we need the special code but it's not supported
@@ -2770,14 +2770,23 @@ setup_socket(pcap_t *handle, int is_any_device)
         */
        if (getsockopt(sock_fd, SOL_SOCKET, SO_BPF_EXTENSIONS,
            &bpf_extensions, &len) == 0) {
+               /*
+                * This is a live capture with some BPF extensions support,
+                * so indicate that at least the auxiliary data items from
+                * Linux 2.6.27 are available (this concerns SKF_AD_PKTTYPE
+                * and SKF_AD_IFINDEX in the first place).
+                */
+               handle->bpf_codegen_flags |= BPF_SPECIAL_BASIC_HANDLING;
+#ifdef SKF_AD_VLAN_TAG_PRESENT
                if (bpf_extensions >= SKF_AD_VLAN_TAG_PRESENT) {
                        /*
                         * Yes, we can.  Request that we do so.
                         */
                        handle->bpf_codegen_flags |= BPF_SPECIAL_VLAN_HANDLING;
                }
+#endif // SKF_AD_VLAN_TAG_PRESENT
        }
-#endif /* defined(SO_BPF_EXTENSIONS) && defined(SKF_AD_VLAN_TAG_PRESENT) */
+#endif // SO_BPF_EXTENSIONS
 
        return status;
 }