Use constant BPF structures and defines to alter the data instead of functions. Smaller code :)

1 files changed, 5 insertions, 24 deletions

diff --git a/lpf.c b/lpf.c
index 0e0b2cf7..4491e0be 100644
--- a/lpf.c
+++ b/lpf.c
@@ -38,6 +38,9 @@
 # include <linux/filter.h>
 # include <netpacket/packet.h>
 # define bpf_insn sock_filter
+# define BPF_SKIPTYPE
+# define BPF_ETHCOOK		-ETH_HLEN
+# define BPF_WHOLEPACKET	65535 /* work around buggy LPF filters */
 #endif
 
 #include <errno.h>
@@ -64,27 +67,6 @@ static const uint8_t ipv4_bcast_addr[] = {
 	0x00, 0x00, 0x00, 0x00, 0xff, 0xff, 0xff, 0xff
 };
 
-void
-setup_packet_filters(void)
-{
-#ifdef __linux__
-	/* We need to massage the filters for Linux cooked packets */
-	dhcp_bpf_filter[1].jf = 0; /* skip the IP packet type check */
-	dhcp_bpf_filter[2].k -= ETH_HLEN;
-	dhcp_bpf_filter[4].k -= ETH_HLEN;
-	dhcp_bpf_filter[6].k -= ETH_HLEN;
-	dhcp_bpf_filter[7].k -= ETH_HLEN;
-
-	arp_bpf_filter[1].jf = 0; /* skip the IP packet type check */
-	arp_bpf_filter[2].k -= ETH_HLEN;
-
-	/* Some buggy Linux kernels do not work with ~0U.
-	 * 65536 should be enough for anyone ;) */
-	dhcp_bpf_filter[9].k = 65536;
-	arp_bpf_filter[5].k = 65536;
-#endif
-}
-
 int
 open_socket(struct interface *iface, int protocol)
 {
@@ -108,14 +90,13 @@ open_socket(struct interface *iface, int protocol)
 		errno = ENOENT;
 		goto eexit;
 	}
-
 	/* Install the DHCP filter */
 	memset(&pf, 0, sizeof(pf));
 	if (protocol == ETHERTYPE_ARP) {
-		pf.filter = arp_bpf_filter;
+		pf.filter = UNCONST(arp_bpf_filter);
 		pf.len = arp_bpf_filter_len;
 	} else {
-		pf.filter = dhcp_bpf_filter;
+		pf.filter = UNCONST(dhcp_bpf_filter);
 		pf.len = dhcp_bpf_filter_len;
 	}
 	if (setsockopt(s, SOL_SOCKET, SO_ATTACH_FILTER, &pf, sizeof(pf)) != 0)