X-Git-Url: https://git.tcpdump.org/libpcap/blobdiff_plain/2c7f925c86ec27823da37c8e21c3eaee9294976c..refs/heads/master:/gencode.c

diff --git a/gencode.c b/gencode.c
index 8d38bb21..0c2f6e0d 100644
--- a/gencode.c
+++ b/gencode.c
@@ -64,7 +64,6 @@
     /* Defines BPF extensions for Npcap */
     #include <npcap-bpf.h>
   #endif
-  #ifdef INET6
     #if defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF)
 /* IPv6 address */
 struct in6_addr
@@ -108,7 +107,6 @@ struct addrinfo {
 };
       #endif /* EAI_ADDRFAMILY */
     #endif /* defined(__MINGW32__) && defined(DEFINE_ADDITIONAL_IPV6_STUFF) */
-  #endif /* INET6 */
 #else /* _WIN32 */
   #include <netdb.h>	/* for "struct addrinfo" */
 #endif /* _WIN32 */
@@ -410,13 +408,6 @@ struct _compiler_state {
 	 */
 	struct addrinfo *ai;
 
-	/*
-	 * Another thing that's allocated is the result of pcap_ether_aton();
-	 * it must be freed with free().  This variable points to any
-	 * address that would need to be freed.
-	 */
-	u_char *e;
-
 	/*
 	 * Various code constructs need to know the layout of the packet.
 	 * These values give the necessary offsets from the beginning
@@ -674,28 +665,23 @@ static struct block *gen_snap(compiler_state_t *, bpf_u_int32, bpf_u_int32);
 static struct block *gen_llc_linktype(compiler_state_t *, bpf_u_int32);
 static struct block *gen_hostop(compiler_state_t *, bpf_u_int32, bpf_u_int32,
     int, u_int, u_int);
-#ifdef INET6
 static struct block *gen_hostop6(compiler_state_t *, struct in6_addr *,
     struct in6_addr *, int, u_int, u_int);
-#endif
 static struct block *gen_ahostop(compiler_state_t *, const uint8_t, int);
-static struct block *gen_ehostop(compiler_state_t *, const u_char *, int);
-static struct block *gen_fhostop(compiler_state_t *, const u_char *, int);
-static struct block *gen_thostop(compiler_state_t *, const u_char *, int);
 static struct block *gen_wlanhostop(compiler_state_t *, const u_char *, int);
-static struct block *gen_ipfchostop(compiler_state_t *, const u_char *, int);
+static unsigned char is_mac48_linktype(const int);
+static struct block *gen_mac48host(compiler_state_t *, const u_char *,
+    const u_char, const char *);
+static struct block *gen_mac48host_byname(compiler_state_t *, const char *,
+    const u_char, const char *);
 static struct block *gen_dnhostop(compiler_state_t *, bpf_u_int32, int);
 static struct block *gen_mpls_linktype(compiler_state_t *, bpf_u_int32);
 static struct block *gen_host(compiler_state_t *, bpf_u_int32, bpf_u_int32,
     int, int, int);
-#ifdef INET6
 static struct block *gen_host6(compiler_state_t *, struct in6_addr *,
     struct in6_addr *, int, int, int);
-#endif
-#ifndef INET6
-static struct block *gen_gateway(compiler_state_t *, const u_char *,
+static struct block *gen_gateway(compiler_state_t *, const char *,
     struct addrinfo *, int);
-#endif
 static struct block *gen_ip_proto(compiler_state_t *, const uint8_t);
 static struct block *gen_ip6_proto(compiler_state_t *, const uint8_t);
 static struct block *gen_ipfrag(compiler_state_t *);
@@ -729,6 +715,8 @@ static struct block *gen_atmfield_code_internal(compiler_state_t *, int,
 static struct block *gen_atmtype_llc(compiler_state_t *);
 static struct block *gen_msg_abbrev(compiler_state_t *, const uint8_t);
 static struct block *gen_atm_prototype(compiler_state_t *, const uint8_t);
+static struct block *gen_atm_vpi(compiler_state_t *, const uint8_t);
+static struct block *gen_atm_vci(compiler_state_t *, const uint16_t);
 
 static void
 initchunks(compiler_state_t *cstate)
@@ -1065,6 +1053,7 @@ assert_maxval(compiler_state_t *cstate, const char *name,
 
 #define ERRSTR_802_11_ONLY_KW "'%s' is valid for 802.11 syntax only"
 #define ERRSTR_INVALID_QUAL "'%s' is not a valid qualifier for '%s'"
+#define ERRSTR_UNKNOWN_MAC48HOST "unknown Ethernet-like host '%s'"
 
 // Validate a port/portrange proto qualifier and map to an IP protocol number.
 static int
@@ -1144,10 +1133,7 @@ pcap_compile(pcap_t *p, struct bpf_program *program,
 
 	initchunks(&cstate);
 	cstate.no_optimize = 0;
-#ifdef INET6
 	cstate.ai = NULL;
-#endif
-	cstate.e = NULL;
 	cstate.ic.root = NULL;
 	cstate.ic.cur_mark = 0;
 	cstate.bpf_pcap = p;
@@ -1183,12 +1169,8 @@ pcap_compile(pcap_t *p, struct bpf_program *program,
 		goto quit;
 	}
 	if (pcap_parse(scanner, &cstate) != 0) {
-#ifdef INET6
 		if (cstate.ai != NULL)
 			freeaddrinfo(cstate.ai);
-#endif
-		if (cstate.e != NULL)
-			free(cstate.e);
 		rc = PCAP_ERROR;
 		goto quit;
 	}
@@ -1455,6 +1437,19 @@ static struct block *
 gen_mcmp(compiler_state_t *cstate, enum e_offrel offrel, u_int offset,
     u_int size, bpf_u_int32 v, bpf_u_int32 mask)
 {
+	/*
+	 * For any A: if mask == 0, it means A & mask == 0, so the result is
+	 * true iff v == 0.  In this case ideally the caller should have
+	 * skipped this invocation and have fewer statement blocks to juggle.
+	 * If the caller could have skipped, but has not, produce a block with
+	 * fewer statements.
+	 *
+	 * This could be done in gen_ncmp() in a more generic way, but this
+	 * function is the only code path that can have mask == 0.
+	 */
+	if (mask == 0)
+		return v ? gen_false(cstate) : gen_true(cstate);
+
 	return gen_ncmp(cstate, offrel, offset, size, mask, BPF_JEQ, 0, v);
 }
 
@@ -4398,7 +4393,6 @@ gen_hostop(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
 	return gen_mcmp(cstate, OR_LINKPL, offset, BPF_W, addr, mask);
 }
 
-#ifdef INET6
 static struct block *
 gen_hostop6(compiler_state_t *cstate, struct in6_addr *addr,
     struct in6_addr *mask, int dir, u_int src_off, u_int dst_off)
@@ -4455,139 +4449,23 @@ gen_hostop6(compiler_state_t *cstate, struct in6_addr *addr,
 	/* this order is important */
 	memcpy(a, addr, sizeof(a));
 	memcpy(m, mask, sizeof(m));
-	b1 = gen_mcmp(cstate, OR_LINKPL, offset + 12, BPF_W, ntohl(a[3]), ntohl(m[3]));
-	b0 = gen_mcmp(cstate, OR_LINKPL, offset + 8, BPF_W, ntohl(a[2]), ntohl(m[2]));
-	gen_and(b0, b1);
-	b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4, BPF_W, ntohl(a[1]), ntohl(m[1]));
-	gen_and(b0, b1);
-	b0 = gen_mcmp(cstate, OR_LINKPL, offset + 0, BPF_W, ntohl(a[0]), ntohl(m[0]));
-	gen_and(b0, b1);
-	return b1;
-}
-#endif
-
-static struct block *
-gen_ehostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-	register struct block *b0, *b1;
-
-	switch (dir) {
-	case Q_SRC:
-		return gen_bcmp(cstate, OR_LINKHDR, 6, 6, eaddr);
-
-	case Q_DST:
-		return gen_bcmp(cstate, OR_LINKHDR, 0, 6, eaddr);
-
-	case Q_AND:
-		b0 = gen_ehostop(cstate, eaddr, Q_SRC);
-		b1 = gen_ehostop(cstate, eaddr, Q_DST);
-		gen_and(b0, b1);
-		return b1;
-
-	case Q_DEFAULT:
-	case Q_OR:
-		b0 = gen_ehostop(cstate, eaddr, Q_SRC);
-		b1 = gen_ehostop(cstate, eaddr, Q_DST);
-		gen_or(b0, b1);
-		return b1;
-
-	case Q_ADDR1:
-	case Q_ADDR2:
-	case Q_ADDR3:
-	case Q_ADDR4:
-	case Q_RA:
-	case Q_TA:
-		bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
-		/*NOTREACHED*/
-	}
-	abort();
-	/*NOTREACHED*/
-}
-
-/*
- * Like gen_ehostop, but for DLT_FDDI
- */
-static struct block *
-gen_fhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-	struct block *b0, *b1;
-
-	switch (dir) {
-	case Q_SRC:
-		return gen_bcmp(cstate, OR_LINKHDR, 6 + 1 + cstate->pcap_fddipad, 6, eaddr);
-
-	case Q_DST:
-		return gen_bcmp(cstate, OR_LINKHDR, 0 + 1 + cstate->pcap_fddipad, 6, eaddr);
-
-	case Q_AND:
-		b0 = gen_fhostop(cstate, eaddr, Q_SRC);
-		b1 = gen_fhostop(cstate, eaddr, Q_DST);
-		gen_and(b0, b1);
-		return b1;
-
-	case Q_DEFAULT:
-	case Q_OR:
-		b0 = gen_fhostop(cstate, eaddr, Q_SRC);
-		b1 = gen_fhostop(cstate, eaddr, Q_DST);
-		gen_or(b0, b1);
-		return b1;
-
-	case Q_ADDR1:
-	case Q_ADDR2:
-	case Q_ADDR3:
-	case Q_ADDR4:
-	case Q_RA:
-	case Q_TA:
-		bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
-		/*NOTREACHED*/
-	}
-	abort();
-	/*NOTREACHED*/
-}
-
-/*
- * Like gen_ehostop, but for DLT_IEEE802 (Token Ring)
- */
-static struct block *
-gen_thostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-	register struct block *b0, *b1;
-
-	switch (dir) {
-	case Q_SRC:
-		return gen_bcmp(cstate, OR_LINKHDR, 8, 6, eaddr);
-
-	case Q_DST:
-		return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr);
-
-	case Q_AND:
-		b0 = gen_thostop(cstate, eaddr, Q_SRC);
-		b1 = gen_thostop(cstate, eaddr, Q_DST);
-		gen_and(b0, b1);
-		return b1;
-
-	case Q_DEFAULT:
-	case Q_OR:
-		b0 = gen_thostop(cstate, eaddr, Q_SRC);
-		b1 = gen_thostop(cstate, eaddr, Q_DST);
-		gen_or(b0, b1);
-		return b1;
-
-	case Q_ADDR1:
-	case Q_ADDR2:
-	case Q_ADDR3:
-	case Q_ADDR4:
-	case Q_RA:
-	case Q_TA:
-		bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
-		/*NOTREACHED*/
+	b1 = NULL;
+	for (int i = 3; i >= 0; i--) {
+		// Same as the Q_IP case in gen_host().
+		if (m[i] == 0 && a[i] == 0)
+			continue;
+		b0 = gen_mcmp(cstate, OR_LINKPL, offset + 4 * i, BPF_W,
+		    ntohl(a[i]), ntohl(m[i]));
+		if (b1)
+			gen_and(b0, b1);
+		else
+			b1 = b0;
 	}
-	abort();
-	/*NOTREACHED*/
+	return b1 ? b1 : gen_true(cstate);
 }
 
 /*
- * Like gen_ehostop, but for DLT_IEEE802_11 (802.11 wireless LAN) and
+ * Like gen_mac48host(), but for DLT_IEEE802_11 (802.11 wireless LAN) and
  * various 802.11 + radio headers.
  */
 static struct block *
@@ -4967,49 +4845,6 @@ gen_wlanhostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
 	/*NOTREACHED*/
 }
 
-/*
- * Like gen_ehostop, but for RFC 2625 IP-over-Fibre-Channel.
- * (We assume that the addresses are IEEE 48-bit MAC addresses,
- * as the RFC states.)
- */
-static struct block *
-gen_ipfchostop(compiler_state_t *cstate, const u_char *eaddr, int dir)
-{
-	register struct block *b0, *b1;
-
-	switch (dir) {
-	case Q_SRC:
-		return gen_bcmp(cstate, OR_LINKHDR, 10, 6, eaddr);
-
-	case Q_DST:
-		return gen_bcmp(cstate, OR_LINKHDR, 2, 6, eaddr);
-
-	case Q_AND:
-		b0 = gen_ipfchostop(cstate, eaddr, Q_SRC);
-		b1 = gen_ipfchostop(cstate, eaddr, Q_DST);
-		gen_and(b0, b1);
-		return b1;
-
-	case Q_DEFAULT:
-	case Q_OR:
-		b0 = gen_ipfchostop(cstate, eaddr, Q_SRC);
-		b1 = gen_ipfchostop(cstate, eaddr, Q_DST);
-		gen_or(b0, b1);
-		return b1;
-
-	case Q_ADDR1:
-	case Q_ADDR2:
-	case Q_ADDR3:
-	case Q_ADDR4:
-	case Q_RA:
-	case Q_TA:
-		bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
-		/*NOTREACHED*/
-	}
-	abort();
-	/*NOTREACHED*/
-}
-
 /*
  * This is quite tricky because there may be pad bytes in front of the
  * DECNET header, and then there are two possible data packet formats that
@@ -5205,18 +5040,33 @@ gen_host(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
 
 	case Q_IP:
 		b0 = gen_linktype(cstate, ETHERTYPE_IP);
+		/*
+		 * Belt and braces: if other code works correctly, any host
+		 * bits are clear and mask == 0 means addr == 0.  In this case
+		 * the call to gen_hostop() would produce an "always true"
+		 * instruction block and ANDing it with the link type check
+		 * would be a no-op.
+		 */
+		if (mask == 0 && addr == 0)
+			return b0;
 		b1 = gen_hostop(cstate, addr, mask, dir, 12, 16);
 		gen_and(b0, b1);
 		return b1;
 
 	case Q_RARP:
 		b0 = gen_linktype(cstate, ETHERTYPE_REVARP);
+		// Same as for Q_IP above.
+		if (mask == 0 && addr == 0)
+			return b0;
 		b1 = gen_hostop(cstate, addr, mask, dir, 14, 24);
 		gen_and(b0, b1);
 		return b1;
 
 	case Q_ARP:
 		b0 = gen_linktype(cstate, ETHERTYPE_ARP);
+		// Same as for Q_IP above.
+		if (mask == 0 && addr == 0)
+			return b0;
 		b1 = gen_hostop(cstate, addr, mask, dir, 14, 24);
 		gen_and(b0, b1);
 		return b1;
@@ -5273,7 +5123,6 @@ gen_host(compiler_state_t *cstate, bpf_u_int32 addr, bpf_u_int32 mask,
 	/*NOTREACHED*/
 }
 
-#ifdef INET6
 static struct block *
 gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
     struct in6_addr *mask, int proto, int dir, int type)
@@ -5285,6 +5134,12 @@ gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
 	case Q_DEFAULT:
 	case Q_IPV6:
 		b0 = gen_linktype(cstate, ETHERTYPE_IPV6);
+		// Same as the Q_IP case in gen_host().
+		if (
+			! memcmp(mask, &in6addr_any, sizeof(struct in6_addr)) &&
+			! memcmp(addr, &in6addr_any, sizeof(struct in6_addr))
+		)
+			return b0;
 		b1 = gen_hostop6(cstate, addr, mask, dir, 8, 24);
 		gen_and(b0, b1);
 		return b1;
@@ -5336,15 +5191,128 @@ gen_host6(compiler_state_t *cstate, struct in6_addr *addr,
 	    type == Q_NET ? "ip6 net" : "ip6 host");
 	/*NOTREACHED*/
 }
-#endif
 
-#ifndef INET6
+static unsigned char
+is_mac48_linktype(const int linktype)
+{
+	switch (linktype) {
+	case DLT_EN10MB:
+	case DLT_FDDI:
+	case DLT_IEEE802:
+	case DLT_IEEE802_11:
+	case DLT_IEEE802_11_RADIO:
+	case DLT_IEEE802_11_RADIO_AVS:
+	case DLT_IP_OVER_FC:
+	case DLT_NETANALYZER:
+	case DLT_NETANALYZER_TRANSPARENT:
+	case DLT_PPI:
+	case DLT_PRISM_HEADER:
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+static struct block *
+gen_mac48host(compiler_state_t *cstate, const u_char *eaddr, const u_char dir,
+    const char *keyword)
+{
+	struct block *b1 = NULL;
+	u_int src_off, dst_off;
+
+	switch (cstate->linktype) {
+	case DLT_EN10MB:
+	case DLT_NETANALYZER:
+	case DLT_NETANALYZER_TRANSPARENT:
+		b1 = gen_prevlinkhdr_check(cstate);
+		src_off = 6;
+		dst_off = 0;
+		break;
+	case DLT_FDDI:
+		src_off = 6 + 1 + cstate->pcap_fddipad;
+		dst_off = 0 + 1 + cstate->pcap_fddipad;
+		break;
+	case DLT_IEEE802:
+		src_off = 8;
+		dst_off = 2;
+		break;
+	case DLT_IEEE802_11:
+	case DLT_PRISM_HEADER:
+	case DLT_IEEE802_11_RADIO_AVS:
+	case DLT_IEEE802_11_RADIO:
+	case DLT_PPI:
+		return gen_wlanhostop(cstate, eaddr, dir);
+	case DLT_IP_OVER_FC:
+		/*
+		 * Assume that the addresses are IEEE 48-bit MAC addresses,
+		 * as RFC 2625 states.
+		 */
+		src_off = 10;
+		dst_off = 2;
+		break;
+	case DLT_SUNATM:
+		/*
+		 * This is LLC-multiplexed traffic; if it were
+		 * LANE, cstate->linktype would have been set to
+		 * DLT_EN10MB.
+		 */
+		 /* FALLTHROUGH */
+	default:
+		fail_kw_on_dlt(cstate, keyword);
+	}
+
+	struct block *b0, *tmp;
+
+	switch (dir) {
+	case Q_SRC:
+		b0 = gen_bcmp(cstate, OR_LINKHDR, src_off, 6, eaddr);
+		break;
+	case Q_DST:
+		b0 = gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, eaddr);
+		break;
+	case Q_AND:
+		tmp = gen_bcmp(cstate, OR_LINKHDR, src_off, 6, eaddr);
+		b0 = gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, eaddr);
+		gen_and(tmp, b0);
+		break;
+	case Q_DEFAULT:
+	case Q_OR:
+		tmp = gen_bcmp(cstate, OR_LINKHDR, src_off, 6, eaddr);
+		b0 = gen_bcmp(cstate, OR_LINKHDR, dst_off, 6, eaddr);
+		gen_or(tmp, b0);
+		break;
+	default:
+		bpf_error(cstate, ERRSTR_802_11_ONLY_KW, dqkw(dir));
+	}
+
+	if (b1 != NULL)
+		gen_and(b1, b0);
+	return b0;
+}
+
+static struct block *
+gen_mac48host_byname(compiler_state_t *cstate, const char *name,
+    const u_char dir, const char *context)
+{
+	if (! is_mac48_linktype(cstate->linktype))
+		fail_kw_on_dlt(cstate, context);
+
+	u_char *eaddrp = pcap_ether_hostton(name);
+	if (eaddrp == NULL)
+		bpf_error(cstate, ERRSTR_UNKNOWN_MAC48HOST, name);
+	u_char eaddr[6];
+	memcpy(eaddr, eaddrp, sizeof(eaddr));
+	free(eaddrp);
+
+	return gen_mac48host(cstate, eaddr, dir, context);
+}
+
 /*
  * This primitive is non-directional by design, so the grammar does not allow
  * to qualify it with a direction.
  */
 static struct block *
-gen_gateway(compiler_state_t *cstate, const u_char *eaddr,
+gen_gateway(compiler_state_t *cstate, const char *name,
     struct addrinfo *alist, int proto)
 {
 	struct block *b0, *b1, *tmp;
@@ -5356,42 +5324,7 @@ gen_gateway(compiler_state_t *cstate, const u_char *eaddr,
 	case Q_IP:
 	case Q_ARP:
 	case Q_RARP:
-		switch (cstate->linktype) {
-		case DLT_EN10MB:
-		case DLT_NETANALYZER:
-		case DLT_NETANALYZER_TRANSPARENT:
-			b1 = gen_prevlinkhdr_check(cstate);
-			b0 = gen_ehostop(cstate, eaddr, Q_OR);
-			if (b1 != NULL)
-				gen_and(b1, b0);
-			break;
-		case DLT_FDDI:
-			b0 = gen_fhostop(cstate, eaddr, Q_OR);
-			break;
-		case DLT_IEEE802:
-			b0 = gen_thostop(cstate, eaddr, Q_OR);
-			break;
-		case DLT_IEEE802_11:
-		case DLT_PRISM_HEADER:
-		case DLT_IEEE802_11_RADIO_AVS:
-		case DLT_IEEE802_11_RADIO:
-		case DLT_PPI:
-			b0 = gen_wlanhostop(cstate, eaddr, Q_OR);
-			break;
-		case DLT_IP_OVER_FC:
-			b0 = gen_ipfchostop(cstate, eaddr, Q_OR);
-			break;
-		case DLT_SUNATM:
-			/*
-			 * This is LLC-multiplexed traffic; if it were
-			 * LANE, cstate->linktype would have been set to
-			 * DLT_EN10MB.
-			 */
-			 /* FALLTHROUGH */
-		default:
-			bpf_error(cstate,
-			    "'gateway' supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
-		}
+		b0 = gen_mac48host_byname(cstate, name, Q_OR, "gateway");
 		b1 = NULL;
 		for (ai = alist; ai != NULL; ai = ai->ai_next) {
 			/*
@@ -5442,7 +5375,6 @@ gen_gateway(compiler_state_t *cstate, const u_char *eaddr,
 	bpf_error(cstate, ERRSTR_INVALID_QUAL, pqkw(proto), "gateway");
 	/*NOTREACHED*/
 }
-#endif
 
 static struct block *
 gen_proto_abbrev_internal(compiler_state_t *cstate, int proto)
@@ -6043,6 +5975,7 @@ gen_protochain(compiler_state_t *cstate, bpf_u_int32 v, int proto)
 	switch (proto) {
 	case Q_IP:
 	case Q_IPV6:
+		assert_maxval(cstate, "protocol number", v, UINT8_MAX);
 		break;
 	case Q_DEFAULT:
 		b0 = gen_protochain(cstate, v, Q_IP);
@@ -6249,12 +6182,10 @@ gen_protochain(compiler_state_t *cstate, bpf_u_int32 v, int proto)
 	 * A = P[X];
 	 * X = X + (P[X + 1] + 2) * 4;
 	 */
-	/* A = X */
-	s[i - 1]->s.jt = s[i] = new_stmt(cstate, BPF_MISC|BPF_TXA);
-	i++;
 	/* A = P[X + packet head]; */
 	s[i] = new_stmt(cstate, BPF_LD|BPF_IND|BPF_B);
 	s[i]->s.k = cstate->off_linkpl.constant_part + cstate->off_nl;
+	s[i - 1]->s.jt = s[i];
 	i++;
 	/* MEM[reg2] = A */
 	s[i] = new_stmt(cstate, BPF_ST);
@@ -6518,9 +6449,7 @@ nametoport(compiler_state_t *cstate, const char *name, int ipproto)
 	struct addrinfo hints, *res, *ai;
 	int error;
 	struct sockaddr_in *in4;
-#ifdef INET6
 	struct sockaddr_in6 *in6;
-#endif
 	int port = -1;
 
 	/*
@@ -6594,13 +6523,11 @@ nametoport(compiler_state_t *cstate, const char *name, int ipproto)
 					port = ntohs(in4->sin_port);
 					break;
 				}
-#ifdef INET6
 				if (ai->ai_addr->sa_family == AF_INET6) {
 					in6 = (struct sockaddr_in6 *)ai->ai_addr;
 					port = ntohs(in6->sin6_port);
 					break;
 				}
-#endif
 			}
 		}
 		freeaddrinfo(res);
@@ -6783,15 +6710,12 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 	int proto = q.proto;
 	int dir = q.dir;
 	int tproto;
-	u_char *eaddr;
 	bpf_u_int32 mask, addr;
 	struct addrinfo *res, *res0;
 	struct sockaddr_in *sin4;
-#ifdef INET6
 	int tproto6;
 	struct sockaddr_in6 *sin6;
 	struct in6_addr mask128;
-#endif /*INET6*/
 	struct block *b, *tmp;
 	int port, real_proto;
 	bpf_u_int32 port1, port2;
@@ -6820,64 +6744,7 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 	case Q_DEFAULT:
 	case Q_HOST:
 		if (proto == Q_LINK) {
-			switch (cstate->linktype) {
-
-			case DLT_EN10MB:
-			case DLT_NETANALYZER:
-			case DLT_NETANALYZER_TRANSPARENT:
-				eaddr = pcap_ether_hostton(name);
-				if (eaddr == NULL)
-					bpf_error(cstate,
-					    "unknown ether host '%s'", name);
-				tmp = gen_prevlinkhdr_check(cstate);
-				b = gen_ehostop(cstate, eaddr, dir);
-				if (tmp != NULL)
-					gen_and(tmp, b);
-				free(eaddr);
-				return b;
-
-			case DLT_FDDI:
-				eaddr = pcap_ether_hostton(name);
-				if (eaddr == NULL)
-					bpf_error(cstate,
-					    "unknown FDDI host '%s'", name);
-				b = gen_fhostop(cstate, eaddr, dir);
-				free(eaddr);
-				return b;
-
-			case DLT_IEEE802:
-				eaddr = pcap_ether_hostton(name);
-				if (eaddr == NULL)
-					bpf_error(cstate,
-					    "unknown token ring host '%s'", name);
-				b = gen_thostop(cstate, eaddr, dir);
-				free(eaddr);
-				return b;
-
-			case DLT_IEEE802_11:
-			case DLT_PRISM_HEADER:
-			case DLT_IEEE802_11_RADIO_AVS:
-			case DLT_IEEE802_11_RADIO:
-			case DLT_PPI:
-				eaddr = pcap_ether_hostton(name);
-				if (eaddr == NULL)
-					bpf_error(cstate,
-					    "unknown 802.11 host '%s'", name);
-				b = gen_wlanhostop(cstate, eaddr, dir);
-				free(eaddr);
-				return b;
-
-			case DLT_IP_OVER_FC:
-				eaddr = pcap_ether_hostton(name);
-				if (eaddr == NULL)
-					bpf_error(cstate,
-					    "unknown Fibre Channel host '%s'", name);
-				b = gen_ipfchostop(cstate, eaddr, dir);
-				free(eaddr);
-				return b;
-			}
-
-			bpf_error(cstate, "only ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel supports link-level host name");
+			return gen_mac48host_byname(cstate, name, q.dir, "link host NAME");
 		} else if (proto == Q_DECNET) {
 			/*
 			 * A long time ago on Ultrix libpcap supported
@@ -6886,39 +6753,30 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 			 */
 			bpf_error(cstate, "invalid DECnet address '%s'", name);
 		} else {
-#ifdef INET6
 			memset(&mask128, 0xff, sizeof(mask128));
-#endif
 			res0 = res = pcap_nametoaddrinfo(name);
 			if (res == NULL)
 				bpf_error(cstate, "unknown host '%s'", name);
 			cstate->ai = res;
 			b = tmp = NULL;
 			tproto = proto;
-#ifdef INET6
 			tproto6 = proto;
-#endif
 			if (cstate->off_linktype.constant_part == OFFSET_NOT_SET &&
 			    tproto == Q_DEFAULT) {
 				tproto = Q_IP;
-#ifdef INET6
 				tproto6 = Q_IPV6;
-#endif
 			}
 			for (res = res0; res; res = res->ai_next) {
 				switch (res->ai_family) {
 				case AF_INET:
-#ifdef INET6
 					if (tproto == Q_IPV6)
 						continue;
-#endif
 
 					sin4 = (struct sockaddr_in *)
 						res->ai_addr;
 					tmp = gen_host(cstate, ntohl(sin4->sin_addr.s_addr),
 						0xffffffff, tproto, dir, q.addr);
 					break;
-#ifdef INET6
 				case AF_INET6:
 					if (tproto6 == Q_IP)
 						continue;
@@ -6928,7 +6786,6 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 					tmp = gen_host6(cstate, &sin6->sin6_addr,
 						&mask128, tproto6, dir, q.addr);
 					break;
-#endif
 				default:
 					continue;
 				}
@@ -7032,25 +6889,16 @@ gen_scode(compiler_state_t *cstate, const char *name, struct qual q)
 		return b;
 
 	case Q_GATEWAY:
-#ifndef INET6
-		eaddr = pcap_ether_hostton(name);
-		if (eaddr == NULL)
-			bpf_error(cstate, "unknown ether host: %s", name);
-
 		res = pcap_nametoaddrinfo(name);
 		cstate->ai = res;
 		if (res == NULL)
 			bpf_error(cstate, "unknown host '%s'", name);
-		b = gen_gateway(cstate, eaddr, res, proto);
+		b = gen_gateway(cstate, name, res, proto);
 		cstate->ai = NULL;
 		freeaddrinfo(res);
-		free(eaddr);
 		if (b == NULL)
 			bpf_error(cstate, "unknown host '%s'", name);
 		return b;
-#else
-		bpf_error(cstate, "'gateway' not supported in this configuration");
-#endif /*INET6*/
 
 	case Q_PROTO:
 		real_proto = lookup_proto(cstate, name, proto);
@@ -7260,7 +7108,6 @@ gen_ncode(compiler_state_t *cstate, const char *s, bpf_u_int32 v, struct qual q)
 	/*NOTREACHED*/
 }
 
-#ifdef INET6
 struct block *
 gen_mcode6(compiler_state_t *cstate, const char *s, bpf_u_int32 masklen,
     struct qual q)
@@ -7322,13 +7169,10 @@ gen_mcode6(compiler_state_t *cstate, const char *s, bpf_u_int32 masklen,
 		/*NOTREACHED*/
 	}
 }
-#endif /*INET6*/
 
 struct block *
 gen_ecode(compiler_state_t *cstate, const char *s, struct qual q)
 {
-	struct block *b, *tmp;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -7336,47 +7180,21 @@ gen_ecode(compiler_state_t *cstate, const char *s, struct qual q)
 	if (setjmp(cstate->top_ctx))
 		return (NULL);
 
-	if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
-		cstate->e = pcap_ether_aton(s);
-		if (cstate->e == NULL)
-			bpf_error(cstate, "malloc");
-		switch (cstate->linktype) {
-		case DLT_EN10MB:
-		case DLT_NETANALYZER:
-		case DLT_NETANALYZER_TRANSPARENT:
-			tmp = gen_prevlinkhdr_check(cstate);
-			b = gen_ehostop(cstate, cstate->e, (int)q.dir);
-			if (tmp != NULL)
-				gen_and(tmp, b);
-			break;
-		case DLT_FDDI:
-			b = gen_fhostop(cstate, cstate->e, (int)q.dir);
-			break;
-		case DLT_IEEE802:
-			b = gen_thostop(cstate, cstate->e, (int)q.dir);
-			break;
-		case DLT_IEEE802_11:
-		case DLT_PRISM_HEADER:
-		case DLT_IEEE802_11_RADIO_AVS:
-		case DLT_IEEE802_11_RADIO:
-		case DLT_PPI:
-			b = gen_wlanhostop(cstate, cstate->e, (int)q.dir);
-			break;
-		case DLT_IP_OVER_FC:
-			b = gen_ipfchostop(cstate, cstate->e, (int)q.dir);
-			break;
-		default:
-			free(cstate->e);
-			cstate->e = NULL;
-			bpf_error(cstate, "ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
-			/*NOTREACHED*/
-		}
-		free(cstate->e);
-		cstate->e = NULL;
-		return (b);
-	}
-	bpf_error(cstate, "ethernet address used in non-ether expression");
-	/*NOTREACHED*/
+	const char *context = "link host XX:XX:XX:XX:XX:XX";
+
+	if (! ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK))
+		bpf_error(cstate, "ethernet address used in non-ether expression");
+	if (! is_mac48_linktype(cstate->linktype))
+		fail_kw_on_dlt(cstate, context);
+
+	u_char *eaddrp = pcap_ether_aton(s);
+	if (eaddrp == NULL)
+		bpf_error(cstate, "malloc");
+	u_char eaddr[6];
+	memcpy(eaddr, eaddrp, sizeof(eaddr));
+	free(eaddrp);
+
+	return gen_mac48host(cstate, eaddr, q.dir, context);
 }
 
 void
@@ -8068,28 +7886,8 @@ gen_broadcast(compiler_state_t *cstate, int proto)
 		case DLT_ARCNET_LINUX:
 			// ARCnet broadcast is [8-bit] destination address 0.
 			return gen_ahostop(cstate, 0, Q_DST);
-		case DLT_EN10MB:
-		case DLT_NETANALYZER:
-		case DLT_NETANALYZER_TRANSPARENT:
-			b1 = gen_prevlinkhdr_check(cstate);
-			b0 = gen_ehostop(cstate, ebroadcast, Q_DST);
-			if (b1 != NULL)
-				gen_and(b1, b0);
-			return b0;
-		case DLT_FDDI:
-			return gen_fhostop(cstate, ebroadcast, Q_DST);
-		case DLT_IEEE802:
-			return gen_thostop(cstate, ebroadcast, Q_DST);
-		case DLT_IEEE802_11:
-		case DLT_PRISM_HEADER:
-		case DLT_IEEE802_11_RADIO_AVS:
-		case DLT_IEEE802_11_RADIO:
-		case DLT_PPI:
-			return gen_wlanhostop(cstate, ebroadcast, Q_DST);
-		case DLT_IP_OVER_FC:
-			return gen_ipfchostop(cstate, ebroadcast, Q_DST);
 		}
-		fail_kw_on_dlt(cstate, "broadcast");
+		return gen_mac48host(cstate, ebroadcast, Q_DST, "broadcast");
 		/*NOTREACHED*/
 
 	case Q_IP:
@@ -8318,8 +8116,6 @@ require_basic_bpf_extensions(compiler_state_t *cstate, const char *keyword)
 struct block *
 gen_ifindex(compiler_state_t *cstate, int ifindex)
 {
-	register struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8333,20 +8129,18 @@ gen_ifindex(compiler_state_t *cstate, int ifindex)
 	switch (cstate->linktype) {
 	case DLT_LINUX_SLL2:
 		/* match packets on this interface */
-		b0 = gen_cmp(cstate, OR_LINKHDR, 4, BPF_W, ifindex);
-		break;
+		return gen_cmp(cstate, OR_LINKHDR, 4, BPF_W, ifindex);
 	default:
 #if defined(__linux__)
 		require_basic_bpf_extensions(cstate, "ifindex");
 		/* match ifindex */
-		b0 = gen_cmp(cstate, OR_LINKHDR, SKF_AD_OFF + SKF_AD_IFINDEX, BPF_W,
+		return gen_cmp(cstate, OR_LINKHDR, SKF_AD_OFF + SKF_AD_IFINDEX, BPF_W,
 		             ifindex);
 #else /* defined(__linux__) */
 		fail_kw_on_dlt(cstate, "ifindex");
 		/*NOTREACHED*/
 #endif /* defined(__linux__) */
 	}
-	return (b0);
 }
 
 /*
@@ -8375,14 +8169,12 @@ gen_inbound_outbound(compiler_state_t *cstate, const int outbound)
 	 */
 	switch (cstate->linktype) {
 	case DLT_SLIP:
-		b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B,
+		return gen_cmp(cstate, OR_LINKHDR, 0, BPF_B,
 			  outbound ? SLIPDIR_OUT : SLIPDIR_IN);
-		break;
 
 	case DLT_IPNET:
-		b0 = gen_cmp(cstate, OR_LINKHDR, 2, BPF_H,
+		return gen_cmp(cstate, OR_LINKHDR, 2, BPF_H,
 		    outbound ? IPNET_OUTBOUND : IPNET_INBOUND);
-		break;
 
 	case DLT_LINUX_SLL:
 		/* match outgoing packets */
@@ -8391,7 +8183,7 @@ gen_inbound_outbound(compiler_state_t *cstate, const int outbound)
 			/* to filter on inbound traffic, invert the match */
 			gen_not(b0);
 		}
-		break;
+		return b0;
 
 	case DLT_LINUX_SLL2:
 		/* match outgoing packets */
@@ -8400,16 +8192,14 @@ gen_inbound_outbound(compiler_state_t *cstate, const int outbound)
 			/* to filter on inbound traffic, invert the match */
 			gen_not(b0);
 		}
-		break;
+		return b0;
 
 	case DLT_PFLOG:
-		b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, dir), BPF_B,
+		return gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, dir), BPF_B,
 		    outbound ? PF_OUT : PF_IN);
-		break;
 
 	case DLT_PPP_PPPD:
-		b0 = gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, outbound ? PPP_PPPD_OUT : PPP_PPPD_IN);
-		break;
+		return gen_cmp(cstate, OR_LINKHDR, 0, BPF_B, outbound ? PPP_PPPD_OUT : PPP_PPPD_IN);
 
 	case DLT_JUNIPER_MFR:
 	case DLT_JUNIPER_MLFR:
@@ -8435,8 +8225,7 @@ gen_inbound_outbound(compiler_state_t *cstate, const int outbound)
 	case DLT_JUNIPER_ATM_CEMIC:
 		/* juniper flags (including direction) are stored
 		 * the byte after the 3-byte magic number */
-		b0 = gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, outbound ? 0 : 1, 0x01);
-		break;
+		return gen_mcmp(cstate, OR_LINKHDR, 3, BPF_B, outbound ? 0 : 1, 0x01);
 
 	default:
 		/*
@@ -8463,19 +8252,18 @@ gen_inbound_outbound(compiler_state_t *cstate, const int outbound)
 			/* to filter on inbound traffic, invert the match */
 			gen_not(b0);
 		}
+		return b0;
 #else /* defined(__linux__) */
 		fail_kw_on_dlt(cstate, outbound ? "outbound" : "inbound");
 		/*NOTREACHED*/
 #endif /* defined(__linux__) */
 	}
-	return (b0);
 }
 
 /* PF firewall log matched interface */
 struct block *
 gen_pf_ifname(compiler_state_t *cstate, const char *ifname)
 {
-	struct block *b0;
 	u_int len, off;
 
 	/*
@@ -8494,17 +8282,14 @@ gen_pf_ifname(compiler_state_t *cstate, const char *ifname)
 		    len-1);
 		/*NOTREACHED*/
 	}
-	b0 = gen_bcmp(cstate, OR_LINKHDR, off, (u_int)strlen(ifname),
+	return gen_bcmp(cstate, OR_LINKHDR, off, (u_int)strlen(ifname),
 	    (const u_char *)ifname);
-	return (b0);
 }
 
 /* PF firewall log ruleset name */
 struct block *
 gen_pf_ruleset(compiler_state_t *cstate, char *ruleset)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8520,17 +8305,14 @@ gen_pf_ruleset(compiler_state_t *cstate, char *ruleset)
 		/*NOTREACHED*/
 	}
 
-	b0 = gen_bcmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, ruleset),
+	return gen_bcmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, ruleset),
 	    (u_int)strlen(ruleset), (const u_char *)ruleset);
-	return (b0);
 }
 
 /* PF firewall log rule number */
 struct block *
 gen_pf_rnr(compiler_state_t *cstate, int rnr)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8540,17 +8322,14 @@ gen_pf_rnr(compiler_state_t *cstate, int rnr)
 
 	assert_pflog(cstate, "rnr");
 
-	b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, rulenr), BPF_W,
+	return gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, rulenr), BPF_W,
 		 (bpf_u_int32)rnr);
-	return (b0);
 }
 
 /* PF firewall log sub-rule number */
 struct block *
 gen_pf_srnr(compiler_state_t *cstate, int srnr)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8560,17 +8339,14 @@ gen_pf_srnr(compiler_state_t *cstate, int srnr)
 
 	assert_pflog(cstate, "srnr");
 
-	b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, subrulenr), BPF_W,
+	return gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, subrulenr), BPF_W,
 	    (bpf_u_int32)srnr);
-	return (b0);
 }
 
 /* PF firewall log reason code */
 struct block *
 gen_pf_reason(compiler_state_t *cstate, int reason)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8580,17 +8356,14 @@ gen_pf_reason(compiler_state_t *cstate, int reason)
 
 	assert_pflog(cstate, "reason");
 
-	b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, reason), BPF_B,
+	return gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, reason), BPF_B,
 	    (bpf_u_int32)reason);
-	return (b0);
 }
 
 /* PF firewall log action */
 struct block *
 gen_pf_action(compiler_state_t *cstate, int action)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8600,17 +8373,14 @@ gen_pf_action(compiler_state_t *cstate, int action)
 
 	assert_pflog(cstate, "action");
 
-	b0 = gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, action), BPF_B,
+	return gen_cmp(cstate, OR_LINKHDR, offsetof(struct pfloghdr, action), BPF_B,
 	    (bpf_u_int32)action);
-	return (b0);
 }
 
 /* IEEE 802.11 wireless header */
 struct block *
 gen_p80211_type(compiler_state_t *cstate, bpf_u_int32 type, bpf_u_int32 mask)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8625,22 +8395,17 @@ gen_p80211_type(compiler_state_t *cstate, bpf_u_int32 type, bpf_u_int32 mask)
 	case DLT_IEEE802_11_RADIO_AVS:
 	case DLT_IEEE802_11_RADIO:
 	case DLT_PPI:
-		b0 = gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, type, mask);
-		break;
+		return gen_mcmp(cstate, OR_LINKHDR, 0, BPF_B, type, mask);
 
 	default:
 		fail_kw_on_dlt(cstate, "type/subtype");
 		/*NOTREACHED*/
 	}
-
-	return (b0);
 }
 
 struct block *
 gen_p80211_fcdir(compiler_state_t *cstate, bpf_u_int32 fcdir)
 {
-	struct block *b0;
-
 	/*
 	 * Catch errors reported by us and routines below us, and return NULL
 	 * on an error.
@@ -8655,17 +8420,13 @@ gen_p80211_fcdir(compiler_state_t *cstate, bpf_u_int32 fcdir)
 	case DLT_IEEE802_11_RADIO_AVS:
 	case DLT_IEEE802_11_RADIO:
 	case DLT_PPI:
-		break;
+		return gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B, fcdir,
+		    IEEE80211_FC1_DIR_MASK);
 
 	default:
 		fail_kw_on_dlt(cstate, "dir");
 		/*NOTREACHED*/
 	}
-
-	b0 = gen_mcmp(cstate, OR_LINKHDR, 1, BPF_B, fcdir,
-	    IEEE80211_FC1_DIR_MASK);
-
-	return (b0);
 }
 
 // Process an ARCnet host address string.
@@ -9717,50 +9478,35 @@ static struct block *
 gen_atmfield_code_internal(compiler_state_t *cstate, int atmfield,
     bpf_u_int32 jvalue, int jtype, int reverse)
 {
-	struct block *b0;
-
 	assert_atm(cstate, atmkw(atmfield));
 
 	switch (atmfield) {
 
 	case A_VPI:
 		assert_maxval(cstate, "VPI", jvalue, UINT8_MAX);
-		b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vpi, BPF_B,
+		return gen_ncmp(cstate, OR_LINKHDR, cstate->off_vpi, BPF_B,
 		    0xffffffffU, jtype, reverse, jvalue);
-		break;
 
 	case A_VCI:
 		assert_maxval(cstate, "VCI", jvalue, UINT16_MAX);
-		b0 = gen_ncmp(cstate, OR_LINKHDR, cstate->off_vci, BPF_H,
+		return gen_ncmp(cstate, OR_LINKHDR, cstate->off_vci, BPF_H,
 		    0xffffffffU, jtype, reverse, jvalue);
-		break;
 
 	default:
 		abort();
 	}
-	return b0;
 }
 
 static struct block *
-gen_atmtype_metac(compiler_state_t *cstate)
+gen_atm_vpi(compiler_state_t *cstate, const uint8_t v)
 {
-	struct block *b0, *b1;
-
-	b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
-	b1 = gen_atmfield_code_internal(cstate, A_VCI, 1, BPF_JEQ, 0);
-	gen_and(b0, b1);
-	return b1;
+	return gen_atmfield_code_internal(cstate, A_VPI, v, BPF_JEQ, 0);
 }
 
 static struct block *
-gen_atmtype_sc(compiler_state_t *cstate)
+gen_atm_vci(compiler_state_t *cstate, const uint16_t v)
 {
-	struct block *b0, *b1;
-
-	b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
-	b1 = gen_atmfield_code_internal(cstate, A_VCI, 5, BPF_JEQ, 0);
-	gen_and(b0, b1);
-	return b1;
+	return gen_atmfield_code_internal(cstate, A_VCI, v, BPF_JEQ, 0);
 }
 
 static struct block *
@@ -9812,41 +9558,45 @@ gen_atmtype_abbrev(compiler_state_t *cstate, int type)
 
 	case A_METAC:
 		/* Get all packets in Meta signalling Circuit */
-		b1 = gen_atmtype_metac(cstate);
-		break;
+		b0 = gen_atm_vpi(cstate, 0);
+		b1 = gen_atm_vci(cstate, 1);
+		gen_and(b0, b1);
+		return b1;
 
 	case A_BCC:
 		/* Get all packets in Broadcast Circuit*/
-		b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
-		b1 = gen_atmfield_code_internal(cstate, A_VCI, 2, BPF_JEQ, 0);
+		b0 = gen_atm_vpi(cstate, 0);
+		b1 = gen_atm_vci(cstate, 2);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_OAMF4SC:
 		/* Get all cells in Segment OAM F4 circuit*/
-		b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
-		b1 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0);
+		b0 = gen_atm_vpi(cstate, 0);
+		b1 = gen_atm_vci(cstate, 3);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_OAMF4EC:
 		/* Get all cells in End-to-End OAM F4 Circuit*/
-		b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
-		b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0);
+		b0 = gen_atm_vpi(cstate, 0);
+		b1 = gen_atm_vci(cstate, 4);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_SC:
 		/*  Get all packets in connection Signalling Circuit */
-		b1 = gen_atmtype_sc(cstate);
-		break;
+		b0 = gen_atm_vpi(cstate, 0);
+		b1 = gen_atm_vci(cstate, 5);
+		gen_and(b0, b1);
+		return b1;
 
 	case A_ILMIC:
 		/* Get all packets in ILMI Circuit */
-		b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
-		b1 = gen_atmfield_code_internal(cstate, A_VCI, 16, BPF_JEQ, 0);
+		b0 = gen_atm_vpi(cstate, 0);
+		b1 = gen_atm_vci(cstate, 16);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_LANE:
 		/* Get all LANE packets */
@@ -9867,12 +9617,11 @@ gen_atmtype_abbrev(compiler_state_t *cstate, int type)
 		cstate->off_linkpl.constant_part = cstate->off_linkhdr.constant_part + 14;	/* Ethernet */
 		cstate->off_nl = 0;			/* Ethernet II */
 		cstate->off_nl_nosnap = 3;		/* 802.3+802.2 */
-		break;
+		return b1;
 
 	default:
 		abort();
 	}
-	return b1;
 }
 
 /*
@@ -9899,9 +9648,8 @@ gen_mtp2type_abbrev(compiler_state_t *cstate, int type)
 	switch (type) {
 
 	case M_FISU:
-		b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B,
+		return gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B,
 		    0x3fU, BPF_JEQ, 0, 0U);
-		break;
 
 	case M_LSSU:
 		b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B,
@@ -9909,17 +9657,15 @@ gen_mtp2type_abbrev(compiler_state_t *cstate, int type)
 		b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B,
 		    0x3fU, BPF_JGT, 0, 0U);
 		gen_and(b1, b0);
-		break;
+		return b0;
 
 	case M_MSU:
-		b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B,
+		return gen_ncmp(cstate, OR_PACKET, cstate->off_li, BPF_B,
 		    0x3fU, BPF_JGT, 0, 2U);
-		break;
 
 	case MH_FISU:
-		b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H,
+		return gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H,
 		    0xff80U, BPF_JEQ, 0, 0U);
-		break;
 
 	case MH_LSSU:
 		b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H,
@@ -9927,17 +9673,15 @@ gen_mtp2type_abbrev(compiler_state_t *cstate, int type)
 		b1 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H,
 		    0xff80U, BPF_JGT, 0, 0U);
 		gen_and(b1, b0);
-		break;
+		return b0;
 
 	case MH_MSU:
-		b0 = gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H,
+		return gen_ncmp(cstate, OR_PACKET, cstate->off_li_hsl, BPF_H,
 		    0xff80U, BPF_JGT, 0, 0x0100U);
-		break;
 
 	default:
 		abort();
 	}
-	return b0;
 }
 
 /*
@@ -9952,7 +9696,6 @@ static struct block *
 gen_mtp3field_code_internal(compiler_state_t *cstate, int mtp3field,
     bpf_u_int32 jvalue, int jtype, int reverse)
 {
-	struct block *b0;
 	u_int newoff_sio;
 	u_int newoff_opc;
 	u_int newoff_dpc;
@@ -9981,9 +9724,8 @@ gen_mtp3field_code_internal(compiler_state_t *cstate, int mtp3field,
 	case M_SIO:
 		assert_maxval(cstate, ss7kw(mtp3field), jvalue, MTP2_SIO_MAXVAL);
 		// Here the bitmask means "do not apply a bitmask".
-		b0 = gen_ncmp(cstate, OR_PACKET, newoff_sio, BPF_B, UINT32_MAX,
+		return gen_ncmp(cstate, OR_PACKET, newoff_sio, BPF_B, UINT32_MAX,
 		    jtype, reverse, jvalue);
-		break;
 
 	/*
 	 * See UTU-T Rec. Q.704, Section 2.2, Figure 3/Q.704.
@@ -10020,10 +9762,9 @@ gen_mtp3field_code_internal(compiler_state_t *cstate, int mtp3field,
 		/* FALLTHROUGH */
 	case M_OPC:
 		assert_maxval(cstate, ss7kw(mtp3field), jvalue, MTP3_PC_MAXVAL);
-		b0 = gen_ncmp(cstate, OR_PACKET, newoff_opc, BPF_W,
+		return gen_ncmp(cstate, OR_PACKET, newoff_opc, BPF_W,
 		    SWAPLONG(MTP3_PC_MAXVAL << 14), jtype, reverse,
 		    SWAPLONG(jvalue << 14));
-		break;
 
 	case MH_DPC:
 		newoff_dpc += 3;
@@ -10031,10 +9772,9 @@ gen_mtp3field_code_internal(compiler_state_t *cstate, int mtp3field,
 
 	case M_DPC:
 		assert_maxval(cstate, ss7kw(mtp3field), jvalue, MTP3_PC_MAXVAL);
-		b0 = gen_ncmp(cstate, OR_PACKET, newoff_dpc, BPF_H,
+		return gen_ncmp(cstate, OR_PACKET, newoff_dpc, BPF_H,
 		    SWAPSHORT(MTP3_PC_MAXVAL), jtype, reverse,
 		    SWAPSHORT(jvalue));
-		break;
 
 	case MH_SLS:
 		newoff_sls += 3;
@@ -10042,15 +9782,13 @@ gen_mtp3field_code_internal(compiler_state_t *cstate, int mtp3field,
 
 	case M_SLS:
 		assert_maxval(cstate, ss7kw(mtp3field), jvalue, MTP3_SLS_MAXVAL);
-		b0 = gen_ncmp(cstate, OR_PACKET, newoff_sls, BPF_B,
+		return gen_ncmp(cstate, OR_PACKET, newoff_sls, BPF_B,
 		    MTP3_SLS_MAXVAL << 4, jtype, reverse,
 		    jvalue << 4);
-		break;
 
 	default:
 		abort();
 	}
-	return b0;
 }
 
 struct block *
@@ -10097,21 +9835,21 @@ gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
 
 	case A_OAM:
 		/* OAM F4 type */
-		b0 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0);
-		b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0);
+		b0 = gen_atm_vci(cstate, 3);
+		b1 = gen_atm_vci(cstate, 4);
 		gen_or(b0, b1);
-		b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
+		b0 = gen_atm_vpi(cstate, 0);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_OAMF4:
 		/* OAM F4 type */
-		b0 = gen_atmfield_code_internal(cstate, A_VCI, 3, BPF_JEQ, 0);
-		b1 = gen_atmfield_code_internal(cstate, A_VCI, 4, BPF_JEQ, 0);
+		b0 = gen_atm_vci(cstate, 3);
+		b1 = gen_atm_vci(cstate, 4);
 		gen_or(b0, b1);
-		b0 = gen_atmfield_code_internal(cstate, A_VPI, 0, BPF_JEQ, 0);
+		b0 = gen_atm_vpi(cstate, 0);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_CONNECTMSG:
 		/*
@@ -10129,9 +9867,9 @@ gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
 		gen_or(b0, b1);
 		b0 = gen_msg_abbrev(cstate, RELEASE_DONE);
 		gen_or(b0, b1);
-		b0 = gen_atmtype_sc(cstate);
+		b0 = gen_atmtype_abbrev(cstate, A_SC);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	case A_METACONNECT:
 		b0 = gen_msg_abbrev(cstate, SETUP);
@@ -10143,12 +9881,11 @@ gen_atmmulti_abbrev(compiler_state_t *cstate, int type)
 		gen_or(b0, b1);
 		b0 = gen_msg_abbrev(cstate, RELEASE_DONE);
 		gen_or(b0, b1);
-		b0 = gen_atmtype_metac(cstate);
+		b0 = gen_atmtype_abbrev(cstate, A_METAC);
 		gen_and(b0, b1);
-		break;
+		return b1;
 
 	default:
 		abort();
 	}
-	return b1;
 }