]> The Tcpdump Group git mirrors - libpcap/blobdiff - gencode.c
Propagate from the main branch:
[libpcap] / gencode.c
index b9f75ccb558793f65271f0e52353e9c7dd4e0314..81da02ef76d26ac90b0ba96c1c30fe6b0ed8e389 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 1.221.2.35 2005-11-17 04:50:13 guy Exp $ (LBL)";
+    "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.221.2.41 2006-09-13 07:02:15 guy Exp $ (LBL)";
 #endif
 
 #ifdef HAVE_CONFIG_H
@@ -668,20 +668,26 @@ 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.
+ * This is the offset of the beginning of the link-layer header from
+ * the beginning of the raw packet data.
+ *
  * It's usually 0, except for 802.11 with a fixed-length radio header.
+ * (For 802.11 with a variable-length radio header, we have to generate
+ * code to compute that offset; off_ll is 0 in that case.)
  */
 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.
+ * It's usually 0, except for ATM LANE, where it's the offset, relative
+ * to the beginning of the raw packet data, of the Ethernet header.
  */
 static u_int off_mac;
 
 /*
  * "off_linktype" is the offset to information in the link-layer header
- * giving the packet type.
+ * giving the packet type.  This offset is relative to the beginning
+ * of the link-layer header (i.e., it doesn't include off_ll).
  *
  * For Ethernet, it's the offset of the Ethernet type field.
  *
@@ -734,6 +740,8 @@ static u_int off_payload;
 
 /*
  * These are offsets to the beginning of the network-layer header.
+ * They are relative to the beginning of the link-layer header (i.e.,
+ * they don't include off_ll).
  *
  * If the link layer never uses 802.2 LLC:
  *
@@ -956,9 +964,9 @@ init_linktype(p)
                 * 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 */
+               off_linktype = 24;
+               off_nl = 32;    /* Prism+802.11+802.2+SNAP */
+               off_nl_nosnap = 27;     /* Prism+802.11+802.2 */
                return;
 
        case DLT_IEEE802_11_RADIO_AVS:
@@ -974,12 +982,23 @@ init_linktype(p)
                 * more so; this header is also variable-length,
                 * with the length being the 32-bit big-endian
                 * number at an offset of 4 from the beginning
-                * of the radio header.
+                * of the radio header.  We should handle that the
+                * same way we handle the length at the beginning
+                * of the radiotap header.
+                *
+                * XXX - in Linux, do any drivers that supply an AVS
+                * header supply a link-layer type other than
+                * ARPHRD_IEEE80211_PRISM?  If so, we should map that
+                * to DLT_IEEE802_11_RADIO_AVS; if not, or if there are
+                * any drivers that supply an AVS header but supply
+                * an ARPHRD value of ARPHRD_IEEE80211_PRISM, we'll
+                * have to check the header in the generated code to
+                * determine whether it's Prism or AVS.
                 */
                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 */
+               off_linktype = 24;
+               off_nl = 32;            /* Radio+802.11+802.2+SNAP */
+               off_nl_nosnap = 27;     /* Radio+802.11+802.2 */
                return;
 
        case DLT_IEEE802_11_RADIO:
@@ -1081,6 +1100,17 @@ init_linktype(p)
                off_nl_nosnap = 0;      /* no 802.2 LLC */
                return;
 
+                /*
+                 * the only BPF-interesting FRF.16 frames are non-control frames;
+                 * Frame Relay has a variable length link-layer
+                 * so lets start with offset 4 for now and increments later on (FIXME);
+                 */
+       case DLT_MFR:
+               off_linktype = -1;
+               off_nl = 4;
+               off_nl_nosnap = 0;      /* XXX - for now -> no 802.2 LLC */
+               return;
+
        case DLT_APPLE_IP_OVER_IEEE1394:
                off_linktype = 16;
                off_nl = 18;
@@ -1229,6 +1259,9 @@ gen_load_llrel(offset, size)
         * If "s" is non-null, it has code to arrange that the X register
         * contains the length of the prefix preceding the link-layer
         * header.
+        *
+        * Otherwise, the length of the prefix preceding the link-layer
+        * header is "off_ll".
         */
        if (s != NULL) {
                s2 = new_stmt(BPF_LD|BPF_IND|size);
@@ -1236,7 +1269,7 @@ gen_load_llrel(offset, size)
                sappend(s, s2);
        } else {
                s = new_stmt(BPF_LD|BPF_ABS|size);
-               s->s.k = offset;
+               s->s.k = offset + off_ll;
        }
        return s;
 }
@@ -1254,11 +1287,12 @@ gen_load_a(offrel, offset, size)
        switch (offrel) {
 
        case OR_PACKET:
-               s = gen_load_llrel(offset, size);
+                s = new_stmt(BPF_LD|BPF_ABS|size);
+                s->s.k = offset;
                break;
 
        case OR_LINK:
-               s = gen_load_llrel(off_ll + offset, size);
+               s = gen_load_llrel(offset, size);
                break;
 
        case OR_NET:
@@ -3368,18 +3402,24 @@ gen_gateway(eaddr, alist, proto, dir)
        case Q_IP:
        case Q_ARP:
        case Q_RARP:
-               if (linktype == DLT_EN10MB)
-                       b0 = gen_ehostop(eaddr, Q_OR);
-               else if (linktype == DLT_FDDI)
-                       b0 = gen_fhostop(eaddr, Q_OR);
-               else if (linktype == DLT_IEEE802)
-                       b0 = gen_thostop(eaddr, Q_OR);
-               else if (linktype == DLT_IEEE802_11 ||
-                   linktype == DLT_IEEE802_11_RADIO_AVS ||
-                   linktype == DLT_IEEE802_11_RADIO ||
-                   linktype == DLT_PRISM_HEADER)
-                       b0 = gen_wlanhostop(eaddr, Q_OR);
-               else if (linktype == DLT_SUNATM && is_lane) {
+                switch (linktype) {
+                case DLT_EN10MB:
+                    b0 = gen_ehostop(eaddr, Q_OR);
+                    break;
+                case DLT_FDDI:
+                    b0 = gen_fhostop(eaddr, Q_OR);
+                    break;
+               case DLT_IEEE802:
+                    b0 = gen_thostop(eaddr, Q_OR);
+                    break;
+               case DLT_IEEE802_11:
+               case DLT_IEEE802_11_RADIO_AVS:
+               case DLT_IEEE802_11_RADIO:
+               case DLT_PRISM_HEADER:
+                    b0 = gen_wlanhostop(eaddr, Q_OR);
+                    break;
+                case DLT_SUNATM:
+                    if (is_lane) {
                        /*
                         * Check that the packet doesn't begin with an
                         * LE Control marker.  (We've already generated
@@ -3394,12 +3434,15 @@ gen_gateway(eaddr, alist, proto, dir)
                         */
                        b0 = gen_ehostop(eaddr, Q_OR);
                        gen_and(b1, b0);
-               } else if (linktype == DLT_IP_OVER_FC)
-                       b0 = gen_ipfchostop(eaddr, Q_OR);
-               else
-                       bpf_error(
+                    }
+                    break;
+               case DLT_IP_OVER_FC:
+                    b0 = gen_ipfchostop(eaddr, Q_OR);
+                    break;
+                default:
+                    bpf_error(
                            "'gateway' supported only on ethernet/FDDI/token ring/802.11/Fibre Channel");
-
+                }
                b1 = gen_host(**alist++, 0xffffffff, proto, Q_OR, Q_HOST);
                while (*alist) {
                        tmp = gen_host(**alist++, 0xffffffff, proto, Q_OR,
@@ -4991,7 +5034,14 @@ gen_mcode(s1, s2, masklen, q)
                /* Convert mask len to mask */
                if (masklen > 32)
                        bpf_error("mask length must be <= 32");
-               m = 0xffffffff << (32 - masklen);
+               if (masklen == 0) {
+                       /*
+                        * X << 32 is not guaranteed by C to be 0; it's
+                        * undefined.
+                        */
+                       m = 0;
+               } else
+                       m = 0xffffffff << (32 - masklen);
                if ((n & ~m) != 0)
                        bpf_error("non-network bits set in \"%s/%d\"",
                            s1, masklen);
@@ -5186,18 +5236,20 @@ gen_ecode(eaddr, q)
        struct block *b, *tmp;
 
        if ((q.addr == Q_HOST || q.addr == Q_DEFAULT) && q.proto == Q_LINK) {
-               if (linktype == DLT_EN10MB)
-                       return gen_ehostop(eaddr, (int)q.dir);
-               if (linktype == DLT_FDDI)
-                       return gen_fhostop(eaddr, (int)q.dir);
-               if (linktype == DLT_IEEE802)
-                       return gen_thostop(eaddr, (int)q.dir);
-               if (linktype == DLT_IEEE802_11 ||
-                   linktype == DLT_IEEE802_11_RADIO_AVS ||
-                   linktype == DLT_IEEE802_11_RADIO ||
-                   linktype == DLT_PRISM_HEADER)
-                       return gen_wlanhostop(eaddr, (int)q.dir);
-               if (linktype == DLT_SUNATM && is_lane) {
+            switch (linktype) {
+            case DLT_EN10MB:
+                return gen_ehostop(eaddr, (int)q.dir);
+            case DLT_FDDI:
+                return gen_fhostop(eaddr, (int)q.dir);
+            case DLT_IEEE802:
+                return gen_thostop(eaddr, (int)q.dir);
+           case DLT_IEEE802_11:
+           case DLT_IEEE802_11_RADIO_AVS:
+           case DLT_IEEE802_11_RADIO:
+           case DLT_PRISM_HEADER:
+                return gen_wlanhostop(eaddr, (int)q.dir);
+            case DLT_SUNATM:
+               if (is_lane) {
                        /*
                         * Check that the packet doesn't begin with an
                         * LE Control marker.  (We've already generated
@@ -5214,9 +5266,13 @@ gen_ecode(eaddr, q)
                        gen_and(tmp, b);
                        return b;
                }
-               if (linktype == DLT_IP_OVER_FC)
-                       return gen_ipfchostop(eaddr, (int)q.dir);
+                break;
+           case DLT_IP_OVER_FC:
+                return gen_ipfchostop(eaddr, (int)q.dir);
+            default:
                bpf_error("ethernet addresses supported only on ethernet/FDDI/token ring/802.11/ATM LANE/Fibre Channel");
+                break;
+            }
        }
        bpf_error("ethernet address used in non-ether expression");
        /* NOTREACHED */
@@ -5751,22 +5807,25 @@ gen_broadcast(proto)
 
        case Q_DEFAULT:
        case Q_LINK:
-               if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
-                       return gen_ahostop(abroadcast, Q_DST);
-               if (linktype == DLT_EN10MB)
-                       return gen_ehostop(ebroadcast, Q_DST);
-               if (linktype == DLT_FDDI)
-                       return gen_fhostop(ebroadcast, Q_DST);
-               if (linktype == DLT_IEEE802)
-                       return gen_thostop(ebroadcast, Q_DST);
-               if (linktype == DLT_IEEE802_11 ||
-                   linktype == DLT_IEEE802_11_RADIO_AVS ||
-                   linktype == DLT_IEEE802_11_RADIO ||
-                   linktype == DLT_PRISM_HEADER)
-                       return gen_wlanhostop(ebroadcast, Q_DST);
-               if (linktype == DLT_IP_OVER_FC)
-                       return gen_ipfchostop(ebroadcast, Q_DST);
-               if (linktype == DLT_SUNATM && is_lane) {
+                switch (linktype) {
+                case DLT_ARCNET:
+                case DLT_ARCNET_LINUX:
+                    return gen_ahostop(abroadcast, Q_DST);
+                case DLT_EN10MB:    
+                    return gen_ehostop(ebroadcast, Q_DST);
+                case DLT_FDDI:
+                    return gen_fhostop(ebroadcast, Q_DST);
+                case DLT_IEEE802:
+                    return gen_thostop(ebroadcast, Q_DST);
+                case DLT_IEEE802_11:
+                case DLT_IEEE802_11_RADIO_AVS:
+                case DLT_IEEE802_11_RADIO:
+                case DLT_PRISM_HEADER:
+                    return gen_wlanhostop(ebroadcast, Q_DST);
+                case DLT_IP_OVER_FC:
+                    return gen_ipfchostop(ebroadcast, Q_DST);
+                case DLT_SUNATM:
+                    if (is_lane) {
                        /*
                         * Check that the packet doesn't begin with an
                         * LE Control marker.  (We've already generated
@@ -5782,8 +5841,11 @@ gen_broadcast(proto)
                        b0 = gen_ehostop(ebroadcast, Q_DST);
                        gen_and(b1, b0);
                        return b0;
-               }
-               bpf_error("not a broadcast link");
+                    }
+                    break;
+                default:
+                    bpf_error("not a broadcast link");
+                }
                break;
 
        case Q_IP:
@@ -5830,154 +5892,146 @@ gen_multicast(proto)
 
        case Q_DEFAULT:
        case Q_LINK:
-               if (linktype == DLT_ARCNET || linktype == DLT_ARCNET_LINUX)
-                       /* all ARCnet multicasts use the same address */
-                       return gen_ahostop(abroadcast, Q_DST);
-
-               if (linktype == DLT_EN10MB) {
-                       /* ether[0] & 1 != 0 */
-                       return gen_mac_multicast(0);
-               }
-
-               if (linktype == DLT_FDDI) {
-                       /*
-                        * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
-                        *
-                        * XXX - was that referring to bit-order issues?
-                        */
-                       /* fddi[1] & 1 != 0 */
-                       return gen_mac_multicast(1);
-               }
-
-               if (linktype == DLT_IEEE802) {
-                       /* tr[2] & 1 != 0 */
-                       return gen_mac_multicast(2);
-               }
-
-               if (linktype == DLT_IEEE802_11 ||
-                   linktype == DLT_IEEE802_11_RADIO_AVS ||
-                   linktype == DLT_IEEE802_11_RADIO ||
-                   linktype == DLT_PRISM_HEADER) {
-                       /*
-                        * Oh, yuk.
-                        *
-                        *      For control frames, there is no DA.
-                        *
-                        *      For management frames, DA is at an
-                        *      offset of 4 from the beginning of
-                        *      the packet.
-                        *
-                        *      For data frames, DA is at an offset
-                        *      of 4 from the beginning of the packet
-                        *      if To DS is clear and at an offset of
-                        *      16 from the beginning of the packet
-                        *      if To DS is set.
-                        */
-
-                       /*
-                        * Generate the tests to be done for data frames.
-                        *
-                        * First, check for To DS set, i.e. "link[1] & 0x01".
-                        */
-                       s = gen_load_a(OR_LINK, 1, BPF_B);
-                       b1 = new_block(JMP(BPF_JSET));
-                       b1->s.k = 0x01; /* To DS */
-                       b1->stmts = s;
-
-                       /*
-                        * If To DS is set, the DA is at 16.
-                        */
-                       b0 = gen_mac_multicast(16);
-                       gen_and(b1, b0);
-
-                       /*
-                        * Now, check for To DS not set, i.e. check
-                        * "!(link[1] & 0x01)".
-                        */
-                       s = gen_load_a(OR_LINK, 1, BPF_B);
-                       b2 = new_block(JMP(BPF_JSET));
-                       b2->s.k = 0x01; /* To DS */
-                       b2->stmts = s;
-                       gen_not(b2);
-
-                       /*
-                        * If To DS is not set, the DA is at 4.
-                        */
-                       b1 = gen_mac_multicast(4);
-                       gen_and(b2, b1);
-
-                       /*
-                        * Now OR together the last two checks.  That gives
-                        * the complete set of checks for data frames.
-                        */
-                       gen_or(b1, b0);
-
-                       /*
-                        * Now check for a data frame.
-                        * I.e, check "link[0] & 0x08".
-                        */
-                       s = gen_load_a(OR_LINK, 0, BPF_B);
-                       b1 = new_block(JMP(BPF_JSET));
-                       b1->s.k = 0x08;
-                       b1->stmts = s;
-
-                       /*
-                        * AND that with the checks done for data frames.
-                        */
-                       gen_and(b1, b0);
-
-                       /*
-                        * If the high-order bit of the type value is 0, this
-                        * is a management frame.
-                        * I.e, check "!(link[0] & 0x08)".
-                        */
-                       s = gen_load_a(OR_LINK, 0, BPF_B);
-                       b2 = new_block(JMP(BPF_JSET));
-                       b2->s.k = 0x08;
-                       b2->stmts = s;
-                       gen_not(b2);
-
-                       /*
-                        * For management frames, the DA is at 4.
-                        */
-                       b1 = gen_mac_multicast(4);
-                       gen_and(b2, b1);
-
-                       /*
-                        * OR that with the checks done for data frames.
-                        * That gives the checks done for management and
-                        * data frames.
-                        */
-                       gen_or(b1, b0);
-
-                       /*
-                        * If the low-order bit of the type value is 1,
-                        * this is either a control frame or a frame
-                        * with a reserved type, and thus not a
-                        * frame with an SA.
-                        *
-                        * I.e., check "!(link[0] & 0x04)".
-                        */
-                       s = gen_load_a(OR_LINK, 0, BPF_B);
-                       b1 = new_block(JMP(BPF_JSET));
-                       b1->s.k = 0x04;
-                       b1->stmts = s;
-                       gen_not(b1);
-
-                       /*
-                        * AND that with the checks for data and management
-                        * frames.
-                        */
-                       gen_and(b1, b0);
-                       return b0;
-               }
-
-               if (linktype == DLT_IP_OVER_FC) {
-                       b0 = gen_mac_multicast(2);
-                       return b0;
-               }
-
-               if (linktype == DLT_SUNATM && is_lane) {
+                switch (linktype) {
+                case DLT_ARCNET:
+                case DLT_ARCNET_LINUX:
+                    /* all ARCnet multicasts use the same address */
+                    return gen_ahostop(abroadcast, Q_DST);
+                case  DLT_EN10MB:
+                    /* ether[0] & 1 != 0 */
+                    return gen_mac_multicast(0);
+                case DLT_FDDI:
+                    /*
+                     * XXX TEST THIS: MIGHT NOT PORT PROPERLY XXX
+                     *
+                     * XXX - was that referring to bit-order issues?
+                     */
+                    /* fddi[1] & 1 != 0 */
+                    return gen_mac_multicast(1);
+                case DLT_IEEE802:
+                    /* tr[2] & 1 != 0 */
+                    return gen_mac_multicast(2);
+                case DLT_IEEE802_11:
+                case DLT_IEEE802_11_RADIO_AVS:
+                case DLT_IEEE802_11_RADIO:
+                case DLT_PRISM_HEADER:
+                    /*
+                     * Oh, yuk.
+                     *
+                     * For control frames, there is no DA.
+                     *
+                     * For management frames, DA is at an
+                     * offset of 4 from the beginning of
+                     * the packet.
+                     *
+                     * For data frames, DA is at an offset
+                     * of 4 from the beginning of the packet
+                     * if To DS is clear and at an offset of
+                     * 16 from the beginning of the packet
+                     * if To DS is set.
+                     */
+                    
+                    /*
+                     * Generate the tests to be done for data frames.
+                     *
+                     * First, check for To DS set, i.e. "link[1] & 0x01".
+                     */
+                    s = gen_load_a(OR_LINK, 1, BPF_B);
+                    b1 = new_block(JMP(BPF_JSET));
+                    b1->s.k = 0x01;    /* To DS */
+                    b1->stmts = s;
+                    
+                    /*
+                     * If To DS is set, the DA is at 16.
+                     */
+                    b0 = gen_mac_multicast(16);
+                    gen_and(b1, b0);
+                    
+                    /*
+                     * Now, check for To DS not set, i.e. check
+                     * "!(link[1] & 0x01)".
+                     */
+                    s = gen_load_a(OR_LINK, 1, BPF_B);
+                    b2 = new_block(JMP(BPF_JSET));
+                    b2->s.k = 0x01;    /* To DS */
+                    b2->stmts = s;
+                    gen_not(b2);
+                    
+                    /*
+                     * If To DS is not set, the DA is at 4.
+                     */
+                    b1 = gen_mac_multicast(4);
+                    gen_and(b2, b1);
+                    
+                    /*
+                     * Now OR together the last two checks.  That gives
+                     * the complete set of checks for data frames.
+                     */
+                    gen_or(b1, b0);
+                    
+                    /*
+                     * Now check for a data frame.
+                     * I.e, check "link[0] & 0x08".
+                     */
+                    s = gen_load_a(OR_LINK, 0, BPF_B);
+                    b1 = new_block(JMP(BPF_JSET));
+                    b1->s.k = 0x08;
+                    b1->stmts = s;
+                    
+                    /*
+                     * AND that with the checks done for data frames.
+                     */
+                    gen_and(b1, b0);
+                    
+                    /*
+                     * If the high-order bit of the type value is 0, this
+                     * is a management frame.
+                     * I.e, check "!(link[0] & 0x08)".
+                     */
+                    s = gen_load_a(OR_LINK, 0, BPF_B);
+                    b2 = new_block(JMP(BPF_JSET));
+                    b2->s.k = 0x08;
+                    b2->stmts = s;
+                    gen_not(b2);
+                    
+                    /*
+                     * For management frames, the DA is at 4.
+                     */
+                    b1 = gen_mac_multicast(4);
+                    gen_and(b2, b1);
+                    
+                    /*
+                     * OR that with the checks done for data frames.
+                     * That gives the checks done for management and
+                     * data frames.
+                     */
+                    gen_or(b1, b0);
+                    
+                    /*
+                     * If the low-order bit of the type value is 1,
+                     * this is either a control frame or a frame
+                     * with a reserved type, and thus not a
+                     * frame with an SA.
+                     *
+                     * I.e., check "!(link[0] & 0x04)".
+                     */
+                    s = gen_load_a(OR_LINK, 0, BPF_B);
+                    b1 = new_block(JMP(BPF_JSET));
+                    b1->s.k = 0x04;
+                    b1->stmts = s;
+                    gen_not(b1);
+                    
+                    /*
+                     * AND that with the checks for data and management
+                     * frames.
+                     */
+                    gen_and(b1, b0);
+                    return b0;
+                case DLT_IP_OVER_FC:
+                    b0 = gen_mac_multicast(2);
+                    return b0;
+                case DLT_SUNATM:
+                    if (is_lane) {
                        /*
                         * Check that the packet doesn't begin with an
                         * LE Control marker.  (We've already generated
@@ -5991,10 +6045,13 @@ gen_multicast(proto)
                        b0 = gen_mac_multicast(off_mac);
                        gen_and(b1, b0);
                        return b0;
-               }
-
-               /* Link not known to support multicasts */
-               break;
+                    }
+                    break;
+                default:
+                    break;
+                }
+                /* Link not known to support multicasts */
+                break;
 
        case Q_IP:
                b0 = gen_linktype(ETHERTYPE_IP);