Make "link[N:M]" refer to the 802.11 header for all 802.11 DLT_ values,

including those with fixed-length radio headers (it already refers to
the 802.11 header for radiotap).

Add a new "radio" keyword, to allow access to the radio header.  In
theory, something to allow testing for specific signal strengths, etc.
might be useful, but radiotap makes that difficult as the code can't
loop through the header looking for the signal strength field, the loop
has to be unrolled, and some of the other headers might not have
standardized the meaning of some of the fields, so we require the user
to construct such a filter themselves, for now.

diff --git a/gencode.c b/gencode.c
index 74052f796443936e1cc62dd669beb0287fb016c4..f44c11139273a21a395e5ae0439a5711bcd16a4d 100644 (file)
--- a/gencode.c
+++ b/gencode.c
@@ -21,7 +21,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.15 2005-05-01 19:33:11 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.16 2005-05-02 21:13:38 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -135,6 +135,7 @@ static struct block *root;
  * is relative to.
  */
 enum e_offrel {
+       OR_PACKET,      /* relative to the beginning of the packet */
        OR_LINK,        /* relative to the link-layer header */
        OR_NET,         /* relative to the network-layer header */
        OR_NET_NOSNAP,  /* relative to the network-layer header, with no SNAP header at the link layer */
@@ -665,6 +666,12 @@ gen_ncmp(offrel, offset, size, mask, jtype, reverse, v)
  */
 static int reg_ll_size;
 
+/*
+ * This is the offset of the beginning of the link-layer header.
+ * It's usually 0, except for 802.11 with a fixed-length radio header.
+ */
+static u_int off_ll;
+
 /*
  * This is the offset of the beginning of the MAC-layer header.
  * It's usually 0, except for ATM LANE.
@@ -763,6 +770,11 @@ init_linktype(p)
        off_proto = -1;
        off_payload = -1;
 
+       /*
+        * Also assume it's not 802.11 with a fixed-length radio header.
+        */
+       off_ll = 0;
+
        orig_linktype = -1;
        orig_nl = -1;
 
@@ -925,6 +937,7 @@ init_linktype(p)
                 * XXX - same variable-length header problem; at least
                 * the Prism header is fixed-length.
                 */
+               off_ll = 144;
                off_linktype = 144+24;
                off_nl = 144+32;        /* Prism+802.11+802.2+SNAP */
                off_nl_nosnap = 144+27; /* Prism+802.11+802.2 */
@@ -945,6 +958,7 @@ init_linktype(p)
                 * number at an offset of 4 from the beginning
                 * of the radio header.
                 */
+               off_ll = 64;
                off_linktype = 64+24;
                off_nl = 64+32;         /* Radio+802.11+802.2+SNAP */
                off_nl_nosnap = 64+27;  /* Radio+802.11+802.2 */
@@ -1161,10 +1175,14 @@ gen_load_a(offrel, offset, size)
 
        switch (offrel) {
 
-       case OR_LINK:
+       case OR_PACKET:
                s = gen_load_llrel(offset, size);
                break;
 
+       case OR_LINK:
+               s = gen_load_llrel(off_ll + offset, size);
+               break;
+
        case OR_NET:
                s = gen_load_llrel(off_nl + offset, size);
                break;
@@ -3051,6 +3069,9 @@ gen_host(addr, mask, proto, dir)
        case Q_NETBEUI:
                bpf_error("'netbeui' modifier applied to host");
 
+       case Q_RADIO:
+               bpf_error("'radio' modifier applied to host");
+
        default:
                abort();
        }
@@ -3157,6 +3178,9 @@ gen_host6(addr, mask, proto, dir)
        case Q_NETBEUI:
                bpf_error("'netbeui' modifier applied to host");
 
+       case Q_RADIO:
+               bpf_error("'radio' modifier applied to host");
+
        default:
                abort();
        }
@@ -3464,6 +3488,9 @@ gen_proto_abbrev(proto)
                b1 = gen_linktype(LLCSAP_NETBEUI);
                break;
 
+       case Q_RADIO:
+               bpf_error("'radio' is not a valid protocol type");
+
        default:
                abort();
        }
@@ -4448,6 +4475,9 @@ gen_proto(v, proto, dir)
        case Q_NETBEUI:
                bpf_error("'netbeui proto' is bogus");
 
+       case Q_RADIO:
+               bpf_error("'radio proto' is bogus");
+
        default:
                abort();
                /* NOTREACHED */
@@ -5093,6 +5123,31 @@ gen_load(proto, index, size)
        default:
                bpf_error("unsupported index operation");
 
+       case Q_RADIO:
+               /*
+                * The offset is relative to the beginning of the packet
+                * data, if we have a radio header.  (If we don't, this
+                * is an error.)
+                */
+               if (linktype != DLT_IEEE802_11_RADIO_AVS &&
+                   linktype != DLT_IEEE802_11_RADIO &&
+                   linktype != DLT_PRISM_HEADER)
+                       bpf_error("radio information not present in capture");
+
+               /*
+                * Load into the X register the offset computed into the
+                * register specifed by "index".
+                */
+               s = xfer_to_x(index);
+
+               /*
+                * Load the item at that offset.
+                */
+               tmp = new_stmt(BPF_LD|BPF_IND|size);
+               sappend(s, tmp);
+               sappend(index->s, s);
+               break;
+
        case Q_LINK:
                /*
                 * The offset is relative to the beginning of
@@ -5124,9 +5179,14 @@ gen_load(proto, index, size)
                        s = xfer_to_x(index);
 
                /*
-                * Load the item at the offset we've put in the X register.
+                * Load the item at the sum of the offset we've put in the
+                * X register and the offset of the start of the link
+                * layer header (which is 0 if the radio header is
+                * variable-length; that header length is what we put
+                * into the X register and then added to the index).
                 */
                tmp = new_stmt(BPF_LD|BPF_IND|size);
+               tmp->s.k = off_ll;
                sappend(s, tmp);
                sappend(index->s, s);
                break;

diff --git a/gencode.h b/gencode.h
index 9cce3954c1d40b8006962761fb80e0fb33902b3a..08f6558c052a6fc9143ff5d9d975e2386feeb50f 100644 (file)
--- a/gencode.h
+++ b/gencode.h
@@ -18,7 +18,7 @@
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  *
- * @(#) $Header: /tcpdump/master/libpcap/gencode.h,v 1.60.2.3 2005-05-01 08:37:50 guy Exp $ (LBL)
+ * @(#) $Header: /tcpdump/master/libpcap/gencode.h,v 1.60.2.4 2005-05-02 21:13:40 guy Exp $ (LBL)
  */
 
 /*
@@ -124,6 +124,8 @@
 #define Q_ISIS_PSNP     38
 #define Q_ISIS_LSP      39
 
+#define Q_RADIO                40
+
 /* Directional qualifiers. */
 
 #define Q_SRC          1

diff --git a/grammar.y b/grammar.y
index bc64f7957fa471a737e64c868880bcd1a9878940..730937bc69ca76dab42ba98224d5f4abac30c99e 100644 (file)
--- a/grammar.y
+++ b/grammar.y
@@ -22,7 +22,7 @@
  */
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/grammar.y,v 1.86.2.2 2005-05-01 08:37:50 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/grammar.y,v 1.86.2.3 2005-05-02 21:13:40 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -134,6 +134,7 @@ pcap_parse()
 %token LANE LLC METAC BCC SC ILMIC OAMF4EC OAMF4SC
 %token OAM OAMF4 CONNECTMSG METACONNECT
 %token VPI VCI
+%token RADIO
 
 %type  <s> ID
 %type  <e> EID
@@ -313,6 +314,7 @@ pname:        LINK                  { $$ = Q_LINK; }
        | STP                   { $$ = Q_STP; }
        | IPX                   { $$ = Q_IPX; }
        | NETBEUI               { $$ = Q_NETBEUI; }
+       | RADIO                 { $$ = Q_RADIO; }
        ;
 other:   pqual TK_BROADCAST    { $$ = gen_broadcast($1); }
        | pqual TK_MULTICAST    { $$ = gen_multicast($1); }

diff --git a/scanner.l b/scanner.l
index 89aed6e2a61c5c676cb492e97890dffe104b619a..b52592e736233163d145e8bb245ee86eb39c0653 100644 (file)
--- a/scanner.l
+++ b/scanner.l
@@ -22,7 +22,7 @@
 
 #ifndef lint
 static const char rcsid[] _U_ =
-    "@(#) $Header: /tcpdump/master/libpcap/scanner.l,v 1.99.2.1 2005-04-19 04:26:08 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/scanner.l,v 1.99.2.2 2005-05-02 21:13:40 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -183,6 +183,7 @@ igmp                return IGMP;
 igrp           return IGRP;
 pim            return PIM;
 vrrp           return VRRP;
+radio          return RADIO;
 
 ip6            {
 #ifdef INET6