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Convert off_linktype to use variable offsets.
[libpcap] / gencode.c
diff --git a/gencode.c b/gencode.c
index ddc587c5b13f4984e8c4c2a2f2935f75b25ab084..c5229550243f1ec49a59191c360cb92feb72e282 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -195,6 +195,7 @@ enum e_offrel {
        OR_PREVLINKHDR,         /* previous link-layer header */
        OR_LLC,                 /* 802.2 LLC header */
        OR_PREVMPLSHDR,         /* previous MPLS header */
        OR_PREVLINKHDR,         /* previous link-layer header */
        OR_LLC,                 /* 802.2 LLC header */
        OR_PREVMPLSHDR,         /* previous MPLS header */
+       OR_LINKTYPE,            /* link-layer type */
        OR_LINKPL,              /* link-layer payload */
        OR_LINKPL_NOSNAP,       /* link-layer payload, with no SNAP header at the link layer */
        OR_TRAN_IPV4,           /* transport-layer header, with IPv4 network layer */
        OR_LINKPL,              /* link-layer payload */
        OR_LINKPL_NOSNAP,       /* link-layer payload, with no SNAP header at the link layer */
        OR_TRAN_IPV4,           /* transport-layer header, with IPv4 network layer */
@@ -834,10 +835,8 @@ static bpf_abs_offset off_linkpl;
 
 /*
  * "off_linktype" is the offset to information in the link-layer header
 
 /*
  * "off_linktype" is the offset to information in the link-layer header
- * giving the packet type.  This offset is relative to the beginning
- * of the link-layer header - i.e., it doesn't include off_linkhdr.constant_part - so
- * loads with an offset that includes "off_linktype" should use
- * OR_LINKHDR.
+ * giving the packet type. This is an absolute offset from the beginning
+ * of the packet.
  *
  * For Ethernet, it's the offset of the Ethernet type field; this
  * means that it must have a value that skips VLAN tags.
  *
  * For Ethernet, it's the offset of the Ethernet type field; this
  * means that it must have a value that skips VLAN tags.
@@ -854,9 +853,10 @@ static bpf_abs_offset off_linkpl;
  *
  * For Linux cooked sockets, it's the offset of the type field.
  *
  *
  * For Linux cooked sockets, it's the offset of the type field.
  *
- * It's set to -1 for no encapsulation, in which case, IP is assumed.
+ * off_linktype.constant_part is set to -1 for no encapsulation,
+ * in which case, IP is assumed.
  */
  */
-static u_int off_linktype;
+static bpf_abs_offset off_linktype;
 
 /*
  * TRUE if the link layer includes an ATM pseudo-header.
 
 /*
  * TRUE if the link layer includes an ATM pseudo-header.
@@ -952,6 +952,10 @@ init_linktype(p)
        off_linkpl.is_variable = 0;
        off_linkpl.reg = -1;
 
        off_linkpl.is_variable = 0;
        off_linkpl.reg = -1;
 
+       off_linktype.constant_part = 0;
+       off_linktype.is_variable = 0;
+       off_linktype.reg = -1;
+
        /*
         * Assume it's not raw ATM with a pseudo-header, for now.
         */
        /*
         * Assume it's not raw ATM with a pseudo-header, for now.
         */
@@ -977,21 +981,21 @@ init_linktype(p)
        switch (linktype) {
 
        case DLT_ARCNET:
        switch (linktype) {
 
        case DLT_ARCNET:
-               off_linktype = 2;
+               off_linktype.constant_part = 2;
                off_linkpl.constant_part = 6;
                off_nl = 0;             /* XXX in reality, variable! */
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_ARCNET_LINUX:
                off_linkpl.constant_part = 6;
                off_nl = 0;             /* XXX in reality, variable! */
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_ARCNET_LINUX:
-               off_linktype = 4;
+               off_linktype.constant_part = 4;
                off_linkpl.constant_part = 8;
                off_nl = 0;             /* XXX in reality, variable! */
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_EN10MB:
                off_linkpl.constant_part = 8;
                off_nl = 0;             /* XXX in reality, variable! */
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_EN10MB:
-               off_linktype = 12;
+               off_linktype.constant_part = 12;
                off_linkpl.constant_part = 14;  /* Ethernet header length */
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 3;      /* 802.3+802.2 */
                off_linkpl.constant_part = 14;  /* Ethernet header length */
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 3;      /* 802.3+802.2 */
@@ -1002,7 +1006,7 @@ init_linktype(p)
                 * SLIP doesn't have a link level type.  The 16 byte
                 * header is hacked into our SLIP driver.
                 */
                 * SLIP doesn't have a link level type.  The 16 byte
                 * header is hacked into our SLIP driver.
                 */
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = 16;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 16;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1010,7 +1014,7 @@ init_linktype(p)
 
        case DLT_SLIP_BSDOS:
                /* XXX this may be the same as the DLT_PPP_BSDOS case */
 
        case DLT_SLIP_BSDOS:
                /* XXX this may be the same as the DLT_PPP_BSDOS case */
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                /* XXX end */
                off_linkpl.constant_part = 24;
                off_nl = 0;
                /* XXX end */
                off_linkpl.constant_part = 24;
                off_nl = 0;
@@ -1019,14 +1023,14 @@ init_linktype(p)
 
        case DLT_NULL:
        case DLT_LOOP:
 
        case DLT_NULL:
        case DLT_LOOP:
-               off_linktype = 0;
+               off_linktype.constant_part = 0;
                off_linkpl.constant_part = 4;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_ENC:
                off_linkpl.constant_part = 4;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_ENC:
-               off_linktype = 0;
+               off_linktype.constant_part = 0;
                off_linkpl.constant_part = 12;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 12;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1036,7 +1040,7 @@ init_linktype(p)
        case DLT_PPP_PPPD:
        case DLT_C_HDLC:                /* BSD/OS Cisco HDLC */
        case DLT_PPP_SERIAL:            /* NetBSD sync/async serial PPP */
        case DLT_PPP_PPPD:
        case DLT_C_HDLC:                /* BSD/OS Cisco HDLC */
        case DLT_PPP_SERIAL:            /* NetBSD sync/async serial PPP */
-               off_linktype = 2;       /* skip HDLC-like framing */
+               off_linktype.constant_part = 2; /* skip HDLC-like framing */
                off_linkpl.constant_part = 4;   /* skip HDLC-like framing and protocol field */
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 4;   /* skip HDLC-like framing and protocol field */
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1047,14 +1051,14 @@ init_linktype(p)
                 * This does no include the Ethernet header, and
                 * only covers session state.
                 */
                 * This does no include the Ethernet header, and
                 * only covers session state.
                 */
-               off_linktype = 6;
+               off_linktype.constant_part = 6;
                off_linkpl.constant_part = 8;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_PPP_BSDOS:
                off_linkpl.constant_part = 8;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_PPP_BSDOS:
-               off_linktype = 5;
+               off_linktype.constant_part = 5;
                off_linkpl.constant_part = 24;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 24;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1069,8 +1073,8 @@ init_linktype(p)
                 * is being used and pick out the encapsulated Ethernet type.
                 * XXX - should we generate code to check for SNAP?
                 */
                 * is being used and pick out the encapsulated Ethernet type.
                 * XXX - should we generate code to check for SNAP?
                 */
-               off_linktype = 13;
-               off_linktype += pcap_fddipad;
+               off_linktype.constant_part = 13;
+               off_linktype.constant_part += pcap_fddipad;
                off_linkpl.constant_part = 13;  /* FDDI MAC header length */
                off_linkpl.constant_part += pcap_fddipad;
                off_nl = 8;             /* 802.2+SNAP */
                off_linkpl.constant_part = 13;  /* FDDI MAC header length */
                off_linkpl.constant_part += pcap_fddipad;
                off_nl = 8;             /* 802.2+SNAP */
@@ -1101,7 +1105,7 @@ init_linktype(p)
                 * the 16-bit value at an offset of 14 (shifted right
                 * 8 - figure out which byte that is).
                 */
                 * the 16-bit value at an offset of 14 (shifted right
                 * 8 - figure out which byte that is).
                 */
-               off_linktype = 14;
+               off_linktype.constant_part = 14;
                off_linkpl.constant_part = 14;  /* Token Ring MAC header length */
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
                off_linkpl.constant_part = 14;  /* Token Ring MAC header length */
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
@@ -1117,7 +1121,8 @@ init_linktype(p)
        case DLT_IEEE802_11:
                /*
                 * 802.11 doesn't really have a link-level type field.
        case DLT_IEEE802_11:
                /*
                 * 802.11 doesn't really have a link-level type field.
-                * We set "off_linktype" to the offset of the LLC header.
+                * We set "off_linktype.constant_part" to the offset of
+                * the LLC header.
                 *
                 * To check for Ethernet types, we assume that SSAP = SNAP
                 * is being used and pick out the encapsulated Ethernet type.
                 *
                 * To check for Ethernet types, we assume that SSAP = SNAP
                 * is being used and pick out the encapsulated Ethernet type.
@@ -1132,7 +1137,7 @@ init_linktype(p)
                 * header or an AVS header, so, in practice, it's
                 * variable-length.
                 */
                 * header or an AVS header, so, in practice, it's
                 * variable-length.
                 */
-               off_linktype = 24;
+               off_linktype.constant_part = 24;
                off_linkpl.constant_part = 0;   /* link-layer header is variable-length */
                off_linkpl.is_variable = 1;
                off_nl = 8;             /* 802.2+SNAP */
                off_linkpl.constant_part = 0;   /* link-layer header is variable-length */
                off_linkpl.is_variable = 1;
                off_nl = 8;             /* 802.2+SNAP */
@@ -1149,7 +1154,7 @@ init_linktype(p)
                 * the encapsulated DLT should be DLT_IEEE802_11) we
                 * generate code to check for this too.
                 */
                 * the encapsulated DLT should be DLT_IEEE802_11) we
                 * generate code to check for this too.
                 */
-               off_linktype = 24;
+               off_linktype.constant_part = 24;
                off_linkpl.constant_part = 0;   /* link-layer header is variable-length */
                off_linkpl.is_variable = 1;
                off_linkhdr.is_variable = 1;
                off_linkpl.constant_part = 0;   /* link-layer header is variable-length */
                off_linkpl.is_variable = 1;
                off_linkhdr.is_variable = 1;
@@ -1170,7 +1175,7 @@ init_linktype(p)
                 * or "pppoa and tcp port 80" and have it check for
                 * PPPo{A,E} and a PPP protocol of IP and....
                 */
                 * or "pppoa and tcp port 80" and have it check for
                 * PPPo{A,E} and a PPP protocol of IP and....
                 */
-               off_linktype = 0;
+               off_linktype.constant_part = 0;
                off_linkpl.constant_part = 0;   /* packet begins with LLC header */
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
                off_linkpl.constant_part = 0;   /* packet begins with LLC header */
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
@@ -1186,7 +1191,7 @@ init_linktype(p)
                off_vci = SUNATM_VCI_POS;
                off_proto = PROTO_POS;
                off_payload = SUNATM_PKT_BEGIN_POS;
                off_vci = SUNATM_VCI_POS;
                off_proto = PROTO_POS;
                off_payload = SUNATM_PKT_BEGIN_POS;
-               off_linktype = off_payload;
+               off_linktype.constant_part = off_payload;
                off_linkpl.constant_part = off_payload; /* if LLC-encapsulated */
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
                off_linkpl.constant_part = off_payload; /* if LLC-encapsulated */
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
@@ -1195,14 +1200,14 @@ init_linktype(p)
        case DLT_RAW:
        case DLT_IPV4:
        case DLT_IPV6:
        case DLT_RAW:
        case DLT_IPV4:
        case DLT_IPV6:
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = 0;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_LINUX_SLL:     /* fake header for Linux cooked socket */
                off_linkpl.constant_part = 0;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_LINUX_SLL:     /* fake header for Linux cooked socket */
-               off_linktype = 14;
+               off_linktype.constant_part = 14;
                off_linkpl.constant_part = 16;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 16;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1214,7 +1219,7 @@ init_linktype(p)
                 * but really it just indicates whether there is a "short" or
                 * "long" DDP packet following.
                 */
                 * but really it just indicates whether there is a "short" or
                 * "long" DDP packet following.
                 */
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = 0;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 0;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1231,7 +1236,7 @@ init_linktype(p)
                 * XXX - should we generate code to check for SNAP? RFC
                 * 2625 says SNAP should be used.
                 */
                 * XXX - should we generate code to check for SNAP? RFC
                 * 2625 says SNAP should be used.
                 */
-               off_linktype = 16;
+               off_linktype.constant_part = 16;
                off_linkpl.constant_part = 16;
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
                off_linkpl.constant_part = 16;
                off_nl = 8;             /* 802.2+SNAP */
                off_nl_nosnap = 3;      /* 802.2 */
@@ -1242,7 +1247,7 @@ init_linktype(p)
                 * XXX - we should set this to handle SNAP-encapsulated
                 * frames (NLPID of 0x80).
                 */
                 * XXX - we should set this to handle SNAP-encapsulated
                 * frames (NLPID of 0x80).
                 */
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = 0;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = 0;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1254,21 +1259,21 @@ init_linktype(p)
                  * so lets start with offset 4 for now and increments later on (FIXME);
                  */
        case DLT_MFR:
                  * so lets start with offset 4 for now and increments later on (FIXME);
                  */
        case DLT_MFR:
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = 0;
                off_nl = 4;
                off_nl_nosnap = 0;      /* XXX - for now -> no 802.2 LLC */
                break;
 
        case DLT_APPLE_IP_OVER_IEEE1394:
                off_linkpl.constant_part = 0;
                off_nl = 4;
                off_nl_nosnap = 0;      /* XXX - for now -> no 802.2 LLC */
                break;
 
        case DLT_APPLE_IP_OVER_IEEE1394:
-               off_linktype = 16;
+               off_linktype.constant_part = 16;
                off_linkpl.constant_part = 18;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_SYMANTEC_FIREWALL:
                off_linkpl.constant_part = 18;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                break;
 
        case DLT_SYMANTEC_FIREWALL:
-               off_linktype = 6;
+               off_linktype.constant_part = 6;
                off_linkpl.constant_part = 44;
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 0;      /* XXX - what does it do with 802.3 packets? */
                off_linkpl.constant_part = 44;
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 0;      /* XXX - what does it do with 802.3 packets? */
@@ -1276,7 +1281,7 @@ init_linktype(p)
 
 #ifdef HAVE_NET_PFVAR_H
        case DLT_PFLOG:
 
 #ifdef HAVE_NET_PFVAR_H
        case DLT_PFLOG:
-               off_linktype = 0;
+               off_linktype.constant_part = 0;
                off_linkpl.constant_part = PFLOG_HDRLEN;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                off_linkpl.constant_part = PFLOG_HDRLEN;
                off_nl = 0;
                off_nl_nosnap = 0;      /* no 802.2 LLC */
@@ -1289,21 +1294,21 @@ init_linktype(p)
         case DLT_JUNIPER_PPP:
         case DLT_JUNIPER_CHDLC:
         case DLT_JUNIPER_FRELAY:
         case DLT_JUNIPER_PPP:
         case DLT_JUNIPER_CHDLC:
         case DLT_JUNIPER_FRELAY:
-                off_linktype = 4;
+                off_linktype.constant_part = 4;
                off_linkpl.constant_part = 4;
                off_nl = 0;
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                 break;
 
        case DLT_JUNIPER_ATM1:
                off_linkpl.constant_part = 4;
                off_nl = 0;
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                 break;
 
        case DLT_JUNIPER_ATM1:
-               off_linktype = 4;               /* in reality variable between 4-8 */
+               off_linktype.constant_part = 4;         /* in reality variable between 4-8 */
                off_linkpl.constant_part = 4;   /* in reality variable between 4-8 */
                off_nl = 0;
                off_nl_nosnap = 10;
                break;
 
        case DLT_JUNIPER_ATM2:
                off_linkpl.constant_part = 4;   /* in reality variable between 4-8 */
                off_nl = 0;
                off_nl_nosnap = 10;
                break;
 
        case DLT_JUNIPER_ATM2:
-               off_linktype = 8;               /* in reality variable between 8-12 */
+               off_linktype.constant_part = 8;         /* in reality variable between 8-12 */
                off_linkpl.constant_part = 8;   /* in reality variable between 8-12 */
                off_nl = 0;
                off_nl_nosnap = 10;
                off_linkpl.constant_part = 8;   /* in reality variable between 8-12 */
                off_nl = 0;
                off_nl_nosnap = 10;
@@ -1314,69 +1319,69 @@ init_linktype(p)
        case DLT_JUNIPER_PPPOE:
         case DLT_JUNIPER_ETHER:
                off_linkpl.constant_part = 14;
        case DLT_JUNIPER_PPPOE:
         case DLT_JUNIPER_ETHER:
                off_linkpl.constant_part = 14;
-               off_linktype = 16;
+               off_linktype.constant_part = 16;
                off_nl = 18;            /* Ethernet II */
                off_nl_nosnap = 21;     /* 802.3+802.2 */
                break;
 
        case DLT_JUNIPER_PPPOE_ATM:
                off_nl = 18;            /* Ethernet II */
                off_nl_nosnap = 21;     /* 802.3+802.2 */
                break;
 
        case DLT_JUNIPER_PPPOE_ATM:
-               off_linktype = 4;
+               off_linktype.constant_part = 4;
                off_linkpl.constant_part = 6;
                off_nl = 0;
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_GGSN:
                off_linkpl.constant_part = 6;
                off_nl = 0;
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_GGSN:
-               off_linktype = 6;
+               off_linktype.constant_part = 6;
                off_linkpl.constant_part = 12;
                off_nl = 0;
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_ES:
                off_linkpl.constant_part = 12;
                off_nl = 0;
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_ES:
-               off_linktype = 6;
+               off_linktype.constant_part = 6;
                off_linkpl.constant_part = -1;  /* not really a network layer but raw IP addresses */
                off_nl = -1;            /* not really a network layer but raw IP addresses */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_MONITOR:
                off_linkpl.constant_part = -1;  /* not really a network layer but raw IP addresses */
                off_nl = -1;            /* not really a network layer but raw IP addresses */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_MONITOR:
-               off_linktype = 12;
+               off_linktype.constant_part = 12;
                off_linkpl.constant_part = 12;
                off_nl = 0;             /* raw IP/IP6 header */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_BACNET_MS_TP:
                off_linkpl.constant_part = 12;
                off_nl = 0;             /* raw IP/IP6 header */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_BACNET_MS_TP:
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_JUNIPER_SERVICES:
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_JUNIPER_SERVICES:
-               off_linktype = 12;
+               off_linktype.constant_part = 12;
                off_linkpl.constant_part = -1;  /* L3 proto location dep. on cookie type */
                off_nl = -1;            /* L3 proto location dep. on cookie type */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_VP:
                off_linkpl.constant_part = -1;  /* L3 proto location dep. on cookie type */
                off_nl = -1;            /* L3 proto location dep. on cookie type */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_JUNIPER_VP:
-               off_linktype = 18;
+               off_linktype.constant_part = 18;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_JUNIPER_ST:
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_JUNIPER_ST:
-               off_linktype = 18;
+               off_linktype.constant_part = 18;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_JUNIPER_ISM:
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_JUNIPER_ISM:
-               off_linktype = 8;
+               off_linktype.constant_part = 8;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
@@ -1386,7 +1391,7 @@ init_linktype(p)
        case DLT_JUNIPER_SRX_E2E:
        case DLT_JUNIPER_FIBRECHANNEL:
        case DLT_JUNIPER_ATM_CEMIC:
        case DLT_JUNIPER_SRX_E2E:
        case DLT_JUNIPER_FIBRECHANNEL:
        case DLT_JUNIPER_ATM_CEMIC:
-               off_linktype = 8;
+               off_linktype.constant_part = 8;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
@@ -1399,7 +1404,7 @@ init_linktype(p)
                off_opc = 4;
                off_dpc = 4;
                off_sls = 7;
                off_opc = 4;
                off_dpc = 4;
                off_sls = 7;
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
@@ -1412,7 +1417,7 @@ init_linktype(p)
                off_opc = 8;
                off_dpc = 8;
                off_sls = 11;
                off_opc = 8;
                off_dpc = 8;
                off_sls = 11;
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
@@ -1425,14 +1430,14 @@ init_linktype(p)
                off_opc = 24;
                off_dpc = 24;
                off_sls = 27;
                off_opc = 24;
                off_dpc = 24;
                off_sls = 27;
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_PFSYNC:
                off_linkpl.constant_part = -1;
                off_nl = -1;
                off_nl_nosnap = -1;
                break;
 
        case DLT_PFSYNC:
-               off_linktype = -1;
+               off_linktype.constant_part = -1;
                off_linkpl.constant_part = 4;
                off_nl = 0;
                off_nl_nosnap = 0;
                off_linkpl.constant_part = 4;
                off_nl = 0;
                off_nl_nosnap = 0;
@@ -1442,14 +1447,14 @@ init_linktype(p)
                /*
                 * Currently, only raw "link[N:M]" filtering is supported.
                 */
                /*
                 * Currently, only raw "link[N:M]" filtering is supported.
                 */
-               off_linktype = -1;      /* variable, min 15, max 71 steps of 7 */
+               off_linktype.constant_part = -1;        /* variable, min 15, max 71 steps of 7 */
                off_linkpl.constant_part = -1;
                off_nl = -1;            /* variable, min 16, max 71 steps of 7 */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_IPNET:
                off_linkpl.constant_part = -1;
                off_nl = -1;            /* variable, min 16, max 71 steps of 7 */
                off_nl_nosnap = -1;     /* no 802.2 LLC */
                break;
 
        case DLT_IPNET:
-               off_linktype = 1;
+               off_linktype.constant_part = 1;
                off_linkpl.constant_part = 24;  /* ipnet header length */
                off_nl = 0;
                off_nl_nosnap = -1;
                off_linkpl.constant_part = 24;  /* ipnet header length */
                off_nl = 0;
                off_nl_nosnap = -1;
@@ -1457,7 +1462,7 @@ init_linktype(p)
 
        case DLT_NETANALYZER:
                off_linkhdr.constant_part = 4;  /* Ethernet header is past 4-byte pseudo-header */
 
        case DLT_NETANALYZER:
                off_linkhdr.constant_part = 4;  /* Ethernet header is past 4-byte pseudo-header */
-               off_linktype = 12;
+               off_linktype.constant_part = off_linkhdr.constant_part + 12;
                off_linkpl.constant_part = off_linkhdr.constant_part + 14;      /* pseudo-header+Ethernet header length */
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 3;      /* 802.3+802.2 */
                off_linkpl.constant_part = off_linkhdr.constant_part + 14;      /* pseudo-header+Ethernet header length */
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 3;      /* 802.3+802.2 */
@@ -1465,7 +1470,7 @@ init_linktype(p)
 
        case DLT_NETANALYZER_TRANSPARENT:
                off_linkhdr.constant_part = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */
 
        case DLT_NETANALYZER_TRANSPARENT:
                off_linkhdr.constant_part = 12; /* MAC header is past 4-byte pseudo-header, preamble, and SFD */
-               off_linktype = 12;
+               off_linktype.constant_part = off_linkhdr.constant_part + 12;
                off_linkpl.constant_part = off_linkhdr.constant_part + 14;      /* pseudo-header+preamble+SFD+Ethernet header length */
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 3;      /* 802.3+802.2 */
                off_linkpl.constant_part = off_linkhdr.constant_part + 14;      /* pseudo-header+preamble+SFD+Ethernet header length */
                off_nl = 0;             /* Ethernet II */
                off_nl_nosnap = 3;      /* 802.3+802.2 */
@@ -1478,7 +1483,7 @@ init_linktype(p)
                 */
                if (linktype >= DLT_MATCHING_MIN &&
                    linktype <= DLT_MATCHING_MAX) {
                 */
                if (linktype >= DLT_MATCHING_MIN &&
                    linktype <= DLT_MATCHING_MAX) {
-                       off_linktype = -1;
+                       off_linktype.constant_part = -1;
                        off_linkpl.constant_part = -1;
                        off_nl = -1;
                        off_nl_nosnap = -1;
                        off_linkpl.constant_part = -1;
                        off_nl = -1;
                        off_nl_nosnap = -1;
@@ -1571,6 +1576,10 @@ gen_load_a(offrel, offset, size)
                s = gen_load_absoffsetrel(&off_linkpl, off_nl_nosnap + offset, size);
                break;
 
                s = gen_load_absoffsetrel(&off_linkpl, off_nl_nosnap + offset, size);
                break;
 
+       case OR_LINKTYPE:
+               s = gen_load_absoffsetrel(&off_linktype, offset, size);
+               break;
+
        case OR_TRAN_IPV4:
                /*
                 * Load the X register with the length of the IPv4 header
        case OR_TRAN_IPV4:
                /*
                 * Load the X register with the length of the IPv4 header
@@ -1733,7 +1742,7 @@ gen_ether_linktype(proto)
                 * DSAP, as we do for other types <= ETHERMTU
                 * (i.e., other SAP values)?
                 */
                 * DSAP, as we do for other types <= ETHERMTU
                 * (i.e., other SAP values)?
                 */
-               b0 = gen_cmp_gt(OR_LINKHDR, off_linktype, BPF_H, ETHERMTU);
+               b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
                gen_not(b0);
                b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)
                             ((proto << 8) | proto));
                gen_not(b0);
                b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)
                             ((proto << 8) | proto));
@@ -1788,7 +1797,7 @@ gen_ether_linktype(proto)
                 * Now we generate code to check for 802.3
                 * frames in general.
                 */
                 * Now we generate code to check for 802.3
                 * frames in general.
                 */
-               b0 = gen_cmp_gt(OR_LINKHDR, off_linktype, BPF_H, ETHERMTU);
+               b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
                gen_not(b0);
 
                /*
                gen_not(b0);
 
                /*
@@ -1804,8 +1813,7 @@ gen_ether_linktype(proto)
                 * do that before checking for the other frame
                 * types.
                 */
                 * do that before checking for the other frame
                 * types.
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
-                   (bpf_int32)ETHERTYPE_IPX);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
                gen_or(b0, b1);
                return b1;
 
                gen_or(b0, b1);
                return b1;
 
@@ -1821,7 +1829,7 @@ gen_ether_linktype(proto)
                 * we check for an Ethernet type field less than
                 * 1500, which means it's an 802.3 length field.
                 */
                 * we check for an Ethernet type field less than
                 * 1500, which means it's an 802.3 length field.
                 */
-               b0 = gen_cmp_gt(OR_LINKHDR, off_linktype, BPF_H, ETHERMTU);
+               b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
                gen_not(b0);
 
                /*
                gen_not(b0);
 
                /*
@@ -1846,7 +1854,7 @@ gen_ether_linktype(proto)
                 * phase 1?); we just check for the Ethernet
                 * protocol type.
                 */
                 * phase 1?); we just check for the Ethernet
                 * protocol type.
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, (bpf_int32)proto);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
 
                gen_or(b0, b1);
                return b1;
 
                gen_or(b0, b1);
                return b1;
@@ -1861,10 +1869,9 @@ gen_ether_linktype(proto)
                         * a length field, <= ETHERMTU) and
                         * then check the DSAP.
                         */
                         * a length field, <= ETHERMTU) and
                         * then check the DSAP.
                         */
-                       b0 = gen_cmp_gt(OR_LINKHDR, off_linktype, BPF_H, ETHERMTU);
+                       b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
                        gen_not(b0);
                        gen_not(b0);
-                       b1 = gen_cmp(OR_LINKHDR, off_linktype + 2, BPF_B,
-                           (bpf_int32)proto);
+                       b1 = gen_cmp(OR_LINKTYPE, 2, BPF_B, (bpf_int32)proto);
                        gen_and(b0, b1);
                        return b1;
                } else {
                        gen_and(b0, b1);
                        return b1;
                } else {
@@ -1877,7 +1884,7 @@ gen_ether_linktype(proto)
                         * will fail and the frame won't match,
                         * which is what we want).
                         */
                         * will fail and the frame won't match,
                         * which is what we want).
                         */
-                       return gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
+                       return gen_cmp(OR_LINKTYPE, 0, BPF_H,
                            (bpf_int32)proto);
                }
        }
                            (bpf_int32)proto);
                }
        }
@@ -1894,12 +1901,11 @@ gen_ipnet_linktype(proto)
        switch (proto) {
 
        case ETHERTYPE_IP:
        switch (proto) {
 
        case ETHERTYPE_IP:
-               return gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
-                   (bpf_int32)IPH_AF_INET);
+               return gen_cmp(OR_LINKTYPE, 0, BPF_B, (bpf_int32)IPH_AF_INET);
                /* NOTREACHED */
 
        case ETHERTYPE_IPV6:
                /* NOTREACHED */
 
        case ETHERTYPE_IPV6:
-               return gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+               return gen_cmp(OR_LINKTYPE, 0, BPF_B,
                    (bpf_int32)IPH_AF_INET6);
                /* NOTREACHED */
 
                    (bpf_int32)IPH_AF_INET6);
                /* NOTREACHED */
 
@@ -1941,7 +1947,7 @@ gen_linux_sll_linktype(proto)
                 * DSAP, as we do for other types <= ETHERMTU
                 * (i.e., other SAP values)?
                 */
                 * DSAP, as we do for other types <= ETHERMTU
                 * (i.e., other SAP values)?
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, LINUX_SLL_P_802_2);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
                b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)
                             ((proto << 8) | proto));
                gen_and(b0, b1);
                b1 = gen_cmp(OR_LLC, 0, BPF_H, (bpf_int32)
                             ((proto << 8) | proto));
                gen_and(b0, b1);
@@ -1976,14 +1982,14 @@ gen_linux_sll_linktype(proto)
                b0 = gen_cmp(OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
                b1 = gen_snap(0x000000, ETHERTYPE_IPX);
                gen_or(b0, b1);
                b0 = gen_cmp(OR_LLC, 0, BPF_B, (bpf_int32)LLCSAP_IPX);
                b1 = gen_snap(0x000000, ETHERTYPE_IPX);
                gen_or(b0, b1);
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, LINUX_SLL_P_802_2);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
                gen_and(b0, b1);
 
                /*
                 * Now check for 802.3 frames and OR that with
                 * the previous test.
                 */
                gen_and(b0, b1);
 
                /*
                 * Now check for 802.3 frames and OR that with
                 * the previous test.
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, LINUX_SLL_P_802_3);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_3);
                gen_or(b0, b1);
 
                /*
                gen_or(b0, b1);
 
                /*
@@ -1991,8 +1997,7 @@ gen_linux_sll_linktype(proto)
                 * do that before checking for the other frame
                 * types.
                 */
                 * do that before checking for the other frame
                 * types.
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
-                   (bpf_int32)ETHERTYPE_IPX);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)ETHERTYPE_IPX);
                gen_or(b0, b1);
                return b1;
 
                gen_or(b0, b1);
                return b1;
 
@@ -2008,7 +2013,7 @@ gen_linux_sll_linktype(proto)
                 * we check for the 802.2 protocol type in the
                 * "Ethernet type" field.
                 */
                 * we check for the 802.2 protocol type in the
                 * "Ethernet type" field.
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, LINUX_SLL_P_802_2);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
 
                /*
                 * 802.2-encapsulated ETHERTYPE_ATALK packets are
 
                /*
                 * 802.2-encapsulated ETHERTYPE_ATALK packets are
@@ -2032,7 +2037,7 @@ gen_linux_sll_linktype(proto)
                 * phase 1?); we just check for the Ethernet
                 * protocol type.
                 */
                 * phase 1?); we just check for the Ethernet
                 * protocol type.
                 */
-               b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, (bpf_int32)proto);
+               b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
 
                gen_or(b0, b1);
                return b1;
 
                gen_or(b0, b1);
                return b1;
@@ -2046,8 +2051,7 @@ gen_linux_sll_linktype(proto)
                         * in the "Ethernet type" field, and
                         * then check the DSAP.
                         */
                         * in the "Ethernet type" field, and
                         * then check the DSAP.
                         */
-                       b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
-                           LINUX_SLL_P_802_2);
+                       b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, LINUX_SLL_P_802_2);
                        b1 = gen_cmp(OR_LINKHDR, off_linkpl.constant_part, BPF_B,
                             (bpf_int32)proto);
                        gen_and(b0, b1);
                        b1 = gen_cmp(OR_LINKHDR, off_linkpl.constant_part, BPF_B,
                             (bpf_int32)proto);
                        gen_and(b0, b1);
@@ -2062,8 +2066,7 @@ gen_linux_sll_linktype(proto)
                         * will fail and the frame won't match,
                         * which is what we want).
                         */
                         * will fail and the frame won't match,
                         * which is what we want).
                         */
-                       return gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
-                           (bpf_int32)proto);
+                       return gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
                }
        }
 }
                }
        }
 }
@@ -2852,8 +2855,7 @@ gen_linktype(proto)
                        /* fall through */
 
                default:
                        /* fall through */
 
                default:
-                       return gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
-                           (bpf_int32)proto);
+                       return gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
                        /*NOTREACHED*/
                        break;
                }
                        /*NOTREACHED*/
                        break;
                }
@@ -2980,7 +2982,7 @@ gen_linktype(proto)
                 * map them to the corresponding PPP protocol types.
                 */
                proto = ethertype_to_ppptype(proto);
                 * map them to the corresponding PPP protocol types.
                 */
                proto = ethertype_to_ppptype(proto);
-               return gen_cmp(OR_LINKHDR, off_linktype, BPF_H, (bpf_int32)proto);
+               return gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
                /*NOTREACHED*/
                break;
 
                /*NOTREACHED*/
                break;
 
@@ -2996,16 +2998,16 @@ gen_linktype(proto)
                         * Also check for Van Jacobson-compressed IP.
                         * XXX - do this for other forms of PPP?
                         */
                         * Also check for Van Jacobson-compressed IP.
                         * XXX - do this for other forms of PPP?
                         */
-                       b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, PPP_IP);
-                       b1 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, PPP_VJC);
+                       b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, PPP_IP);
+                       b1 = gen_cmp(OR_LINKTYPE, 0, BPF_H, PPP_VJC);
                        gen_or(b0, b1);
                        gen_or(b0, b1);
-                       b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_H, PPP_VJNC);
+                       b0 = gen_cmp(OR_LINKTYPE, 0, BPF_H, PPP_VJNC);
                        gen_or(b1, b0);
                        return b0;
 
                default:
                        proto = ethertype_to_ppptype(proto);
                        gen_or(b1, b0);
                        return b0;
 
                default:
                        proto = ethertype_to_ppptype(proto);
-                       return gen_cmp(OR_LINKHDR, off_linktype, BPF_H,
+                       return gen_cmp(OR_LINKTYPE, 0, BPF_H,
                                (bpf_int32)proto);
                }
                /*NOTREACHED*/
                                (bpf_int32)proto);
                }
                /*NOTREACHED*/
@@ -3106,31 +3108,31 @@ gen_linktype(proto)
                        return gen_false();
 
                case ETHERTYPE_IPV6:
                        return gen_false();
 
                case ETHERTYPE_IPV6:
-                       return (gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       return (gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                (bpf_int32)ARCTYPE_INET6));
 
                case ETHERTYPE_IP:
                                (bpf_int32)ARCTYPE_INET6));
 
                case ETHERTYPE_IP:
-                       b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       b0 = gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                     (bpf_int32)ARCTYPE_IP);
                                     (bpf_int32)ARCTYPE_IP);
-                       b1 = gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       b1 = gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                     (bpf_int32)ARCTYPE_IP_OLD);
                        gen_or(b0, b1);
                        return (b1);
 
                case ETHERTYPE_ARP:
                                     (bpf_int32)ARCTYPE_IP_OLD);
                        gen_or(b0, b1);
                        return (b1);
 
                case ETHERTYPE_ARP:
-                       b0 = gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       b0 = gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                     (bpf_int32)ARCTYPE_ARP);
                                     (bpf_int32)ARCTYPE_ARP);
-                       b1 = gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       b1 = gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                     (bpf_int32)ARCTYPE_ARP_OLD);
                        gen_or(b0, b1);
                        return (b1);
 
                case ETHERTYPE_REVARP:
                                     (bpf_int32)ARCTYPE_ARP_OLD);
                        gen_or(b0, b1);
                        return (b1);
 
                case ETHERTYPE_REVARP:
-                       return (gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       return (gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                        (bpf_int32)ARCTYPE_REVARP));
 
                case ETHERTYPE_ATALK:
                                        (bpf_int32)ARCTYPE_REVARP));
 
                case ETHERTYPE_ATALK:
-                       return (gen_cmp(OR_LINKHDR, off_linktype, BPF_B,
+                       return (gen_cmp(OR_LINKTYPE, 0, BPF_B,
                                        (bpf_int32)ARCTYPE_ATALK));
                }
                /*NOTREACHED*/
                                        (bpf_int32)ARCTYPE_ATALK));
                }
                /*NOTREACHED*/
@@ -3295,16 +3297,16 @@ gen_linktype(proto)
                /*
                 * Does this link-layer header type have a field
                 * indicating the type of the next protocol?  If
                /*
                 * Does this link-layer header type have a field
                 * indicating the type of the next protocol?  If
-                * so, off_linktype will be the offset of that
+                * so, off_linktype.constant_part will be the offset of that
                 * field in the packet; if not, it will be -1.
                 */
                 * field in the packet; if not, it will be -1.
                 */
-               if (off_linktype != (u_int)-1) {
+               if (off_linktype.constant_part != (u_int)-1) {
                        /*
                         * Yes; assume it's an Ethernet type.  (If
                         * it's not, it needs to be handled specially
                         * above.)
                         */
                        /*
                         * Yes; assume it's an Ethernet type.  (If
                         * it's not, it needs to be handled specially
                         * above.)
                         */
-                       return gen_cmp(OR_LINKHDR, off_linktype, BPF_H, (bpf_int32)proto);
+                       return gen_cmp(OR_LINKTYPE, 0, BPF_H, (bpf_int32)proto);
                } else {
                        /*
                         * No; report an error.
                } else {
                        /*
                         * No; report an error.
@@ -3362,7 +3364,7 @@ gen_llc(void)
                 * We check for an Ethernet type field less than
                 * 1500, which means it's an 802.3 length field.
                 */
                 * We check for an Ethernet type field less than
                 * 1500, which means it's an 802.3 length field.
                 */
-               b0 = gen_cmp_gt(OR_LINKHDR, off_linktype, BPF_H, ETHERMTU);
+               b0 = gen_cmp_gt(OR_LINKTYPE, 0, BPF_H, ETHERMTU);
                gen_not(b0);
 
                /*
                gen_not(b0);
 
                /*
@@ -6170,7 +6172,8 @@ gen_scode(name, q)
                        if (alist == NULL || *alist == NULL)
                                bpf_error("unknown host '%s'", name);
                        tproto = proto;
                        if (alist == NULL || *alist == NULL)
                                bpf_error("unknown host '%s'", name);
                        tproto = proto;
-                       if (off_linktype == (u_int)-1 && tproto == Q_DEFAULT)
+                       if (off_linktype.constant_part == (u_int)-1 &&
+                           tproto == Q_DEFAULT)
                                tproto = Q_IP;
                        b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr);
                        while (*alist) {
                                tproto = Q_IP;
                        b = gen_host(**alist++, 0xffffffff, tproto, dir, q.addr);
                        while (*alist) {
@@ -6188,7 +6191,8 @@ gen_scode(name, q)
                        ai = res;
                        b = tmp = NULL;
                        tproto = tproto6 = proto;
                        ai = res;
                        b = tmp = NULL;
                        tproto = tproto6 = proto;
-                       if (off_linktype == -1 && tproto == Q_DEFAULT) {
+                       if (off_linktype.constant_part == -1 &&
+                           tproto == Q_DEFAULT) {
                                tproto = Q_IP;
                                tproto6 = Q_IPV6;
                        }
                                tproto = Q_IP;
                                tproto6 = Q_IPV6;
                        }
@@ -7893,7 +7897,7 @@ gen_vlan_no_bpf_extensions(int vlan_num)
         * The link-layer type information follows the VLAN tags, so
         * skip past this VLAN tag.
         */
         * The link-layer type information follows the VLAN tags, so
         * skip past this VLAN tag.
         */
-        off_linktype += 4;
+        off_linktype.constant_part += 4;
 
         return b0;
 }
 
         return b0;
 }
@@ -8127,7 +8131,7 @@ gen_pppoes(sess_num)
            off_linkpl.constant_part + off_nl + 6, /* 6 bytes past the PPPoE header */
            off_linkpl.reg);
 
            off_linkpl.constant_part + off_nl + 6, /* 6 bytes past the PPPoE header */
            off_linkpl.reg);
 
-       off_linktype = 0;
+       off_linktype = off_linkhdr;
        off_linkpl.constant_part = off_linkhdr.constant_part + 2;
 
        off_nl = 0;
        off_linkpl.constant_part = off_linkhdr.constant_part + 2;
 
        off_nl = 0;
@@ -8273,7 +8277,7 @@ gen_atmtype_abbrev(type)
                PUSH_LINKHDR(DLT_EN10MB, 0,
                    off_payload + 2,    /* Ethernet header */
                    -1);
                PUSH_LINKHDR(DLT_EN10MB, 0,
                    off_payload + 2,    /* Ethernet header */
                    -1);
-               off_linktype = 12;
+               off_linktype.constant_part = off_linkhdr.constant_part + 12;
                off_linkpl.constant_part = off_linkhdr.constant_part + 14;      /* Ethernet */
                off_nl = 0;                     /* Ethernet II */
                off_nl_nosnap = 3;              /* 802.3+802.2 */
                off_linkpl.constant_part = off_linkhdr.constant_part + 14;      /* Ethernet */
                off_nl = 0;                     /* Ethernet II */
                off_nl_nosnap = 3;              /* 802.3+802.2 */
[mirror] the LIBpcap interface to various kernel packet capture mechanism