*/
#ifndef lint
static const char rcsid[] =
- "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.177 2002-08-08 09:09:58 guy Exp $ (LBL)";
+ "@(#) $Header: /tcpdump/master/libpcap/gencode.c,v 1.178 2002-08-08 11:07:27 guy Exp $ (LBL)";
#endif
#ifdef HAVE_CONFIG_H
register const u_char *eaddr;
register int dir;
{
- register struct block *b0, *b1, *b2, *b3;
+ register struct block *b0, *b1, *b2;
register struct slist *s;
switch (dir) {
*/
/*
- * 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.
+ * Generate the tests to be done for data frames
+ * with From DS set.
*
- * I.e., first check "!(link[0] & 0x04)".
+ * First, check for To DS set, i.e. check "link[1] & 0x01".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 0x04;
- b0->stmts = s;
- gen_not(b0);
+ s->s.k = 1;
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01; /* To DS */
+ b1->stmts = s;
/*
- * If the high-order bit of the type value is 0, this
- * is a management frame.
- * I.e, check "!(link[0] & 0x08)".
+ * If To DS is set, the SA is at 24.
+ */
+ b0 = gen_bcmp(24, 6, eaddr);
+ gen_and(b1, b0);
+
+ /*
+ * Now, check for To DS not set, i.e. check
+ * "!(link[1] & 0x01)".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
+ s->s.k = 1;
b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x08;
+ b2->s.k = 0x01; /* To DS */
b2->stmts = s;
gen_not(b2);
/*
- * For management frames, test the SA at 10.
+ * If To DS is not set, the SA is at 16.
*/
- b1 = gen_bcmp(10, 6, eaddr);
+ b1 = gen_bcmp(16, 6, eaddr);
gen_and(b2, b1);
- b3 = b1;
/*
- * If the high-order bit of the type value is 0, this
- * is a data frame; check From DS.
- *
- * I.e., check "(link[0] & 0x08) && !(link[1] & 0x02)".
+ * Now OR together the last two checks. That gives
+ * the complete set of checks for data frames with
+ * From DS set.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * Now check for From DS being set, and AND that with
+ * the ORed-together checks.
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
+ s->s.k = 1;
b1 = new_block(JMP(BPF_JSET));
- b1->s.k = 0x08;
+ b1->s.k = 0x02; /* From DS */
b1->stmts = s;
+ gen_and(b1, b0);
+ /*
+ * Now check for data frames with From DS not set.
+ */
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 1;
b2 = new_block(JMP(BPF_JSET));
b2->s.k = 0x02; /* From DS */
b2->stmts = s;
gen_not(b2);
- gen_and(b1, b2);
/*
- * For data frames with From DS not set, test the SA at 10;
- * then combine that test with the management frame test.
+ * If From DS isn't set, the SA is at 10.
*/
b1 = gen_bcmp(10, 6, eaddr);
gen_and(b2, b1);
- gen_or(b3, b1);
- b3 = b1;
/*
- * Now, check for a data frame with From DS set and
- * To DS not set.
- *
- * I.e., check "(link[0] & 0x08) && (link[1] & 0x02)
- * && !(link[1] & 0x01)".
+ * Now OR together the checks for data frames with
+ * From DS not set and for data frames with From DS
+ * set; that gives the checks done for data frames.
+ */
+ gen_or(b1, b0);
+
+ /*
+ * Now check for a data frame.
+ * I.e, check "link[0] & 0x08".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 0;
b1->s.k = 0x08;
b1->stmts = s;
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x02; /* From DS */
- b2->stmts = s;
- gen_and(b1, b2);
- b1 = b2;
+ /*
+ * 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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
+ s->s.k = 0;
b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x01; /* To DS */
+ b2->s.k = 0x08;
b2->stmts = s;
gen_not(b2);
- gen_and(b1, b2); /* Data && From DS and not To DS */
/*
- * Test the SA at 16, and OR the previous SA tests
- * with it.
+ * For management frames, the SA is at 10.
*/
- b1 = gen_bcmp(16, 6, eaddr);
+ b1 = gen_bcmp(10, 6, eaddr);
gen_and(b2, b1);
- gen_or(b3, b1);
- b3 = b1;
/*
- * And now for a data frame with From DS set and To DS set.
+ * 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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 0;
b1 = new_block(JMP(BPF_JSET));
- b1->s.k = 0x08;
+ b1->s.k = 0x04;
b1->stmts = s;
-
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x02; /* From DS */
- b2->stmts = s;
- gen_and(b1, b2);
- b1 = b2;
-
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x01; /* To DS */
- b2->stmts = s;
- gen_and(b1, b2); /* Data && From DS and To DS */
+ gen_not(b1);
/*
- * Test the SA at 24, and OR the previous SA tests
- * with it.
+ * AND that with the checks for data and management
+ * frames.
*/
- b1 = gen_bcmp(24, 6, eaddr);
- gen_and(b2, b1);
- gen_or(b3, b1);
-
- gen_and(b0, b1);
- return b1;
+ gen_and(b1, b0);
+ return b0;
case Q_DST:
/*
*/
/*
- * 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 a DA.
+ * Generate the tests to be done for data frames.
*
- * I.e., first check "!(link[0] & 0x04)".
+ * First, check for To DS set, i.e. "link[1] & 0x01".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 0x04;
- b0->stmts = s;
- gen_not(b0);
+ s->s.k = 1;
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01; /* To DS */
+ b1->stmts = s;
/*
- * If the high-order bit of the type value is 0, this
- * is a management frame.
- * I.e, check "!(link[0] & 0x08)".
+ * If To DS is set, the DA is at 16.
+ */
+ b0 = gen_bcmp(16, 6, eaddr);
+ gen_and(b1, b0);
+
+ /*
+ * Now, check for To DS not set, i.e. check
+ * "!(link[1] & 0x01)".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
+ s->s.k = 1;
b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x08;
+ b2->s.k = 0x01; /* To DS */
b2->stmts = s;
gen_not(b2);
/*
- * For management frames, test the DA at 4.
+ * If To DS is not set, the DA is at 4.
*/
b1 = gen_bcmp(4, 6, eaddr);
gen_and(b2, b1);
- b3 = b1;
/*
- * If the high-order bit of the type value is 0, this
- * is a data frame; check To DS.
- *
- * I.e., check "(link[0] & 0x08) && !(link[1] & 0x01)".
+ * 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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 0;
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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
+ s->s.k = 0;
b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x01; /* To DS */
+ b2->s.k = 0x08;
b2->stmts = s;
gen_not(b2);
- gen_and(b1, b2);
/*
- * For data frames with To DS not set, test the DA at 4;
- * then combine that test with the management frame test.
+ * For management frames, the DA is at 4.
*/
b1 = gen_bcmp(4, 6, eaddr);
gen_and(b2, b1);
- gen_or(b3, b1);
- b3 = b1;
/*
- * Now, check for a data frame with To DS set.
+ * 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] & 0x08) && (link[1] & 0x01)".
+ * I.e., check "!(link[0] & 0x04)".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 0;
b1 = new_block(JMP(BPF_JSET));
- b1->s.k = 0x08;
+ b1->s.k = 0x04;
b1->stmts = s;
-
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x01; /* To DS */
- b2->stmts = s;
- gen_and(b1, b2);
+ gen_not(b1);
/*
- * Test the DA at 16, and OR the previous DA tests
- * with it.
+ * AND that with the checks for data and management
+ * frames.
*/
- b1 = gen_bcmp(16, 6, eaddr);
- gen_and(b2, b1);
- gen_or(b3, b1);
-
- gen_and(b0, b1);
- return b1;
+ gen_and(b1, b0);
+ return b0;
case Q_AND:
b0 = gen_wlanhostop(eaddr, Q_SRC);
gen_multicast(proto)
int proto;
{
- register struct block *b0, *b1, *b2, *b3;
+ register struct block *b0, *b1, *b2;
register struct slist *s;
switch (proto) {
*/
/*
- * 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 a DA.
+ * Generate the tests to be done for data frames.
*
- * I.e., first check "!(link[0] & 0x04)".
+ * First, check for To DS set, i.e. "link[1] & 0x01".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
- b0 = new_block(JMP(BPF_JSET));
- b0->s.k = 0x04;
- b0->stmts = s;
- gen_not(b0);
+ s->s.k = 1;
+ b1 = new_block(JMP(BPF_JSET));
+ b1->s.k = 0x01; /* To DS */
+ b1->stmts = s;
/*
- * If the high-order bit of the type value is 0,
- * this is a management frame.
- * I.e, check "!(link[0] & 0x08)".
+ * 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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 0;
+ s->s.k = 1;
b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x08;
+ b2->s.k = 0x01; /* To DS */
b2->stmts = s;
gen_not(b2);
/*
- * For management frames, test the DA at 4.
+ * If To DS is not set, the DA is at 4.
*/
b1 = gen_mac_multicast(4);
gen_and(b2, b1);
- b3 = b1;
/*
- * If the high-order bit of the type value is 0,
- * this is a data frame; check To DS.
- *
- * I.e., check "(link[0] & 0x08) && !(link[1] & 0x01)".
+ * 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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 0;
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 = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
+ s->s.k = 0;
b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x01; /* To DS */
+ b2->s.k = 0x08;
b2->stmts = s;
gen_not(b2);
- gen_and(b1, b2);
/*
- * For data frames with To DS not set, test the DA
- * at 4; then combine that test with the management
- * frame test.
+ * For management frames, the DA is at 4.
*/
b1 = gen_mac_multicast(4);
gen_and(b2, b1);
- gen_or(b3, b1);
- b3 = b1;
/*
- * Now, check for a data frame with To DS set.
+ * 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] & 0x08) && (link[1] & 0x01)".
+ * I.e., check "!(link[0] & 0x04)".
*/
s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
s->s.k = 0;
b1 = new_block(JMP(BPF_JSET));
- b1->s.k = 0x08;
+ b1->s.k = 0x04;
b1->stmts = s;
-
- s = new_stmt(BPF_LD|BPF_B|BPF_ABS);
- s->s.k = 1;
- b2 = new_block(JMP(BPF_JSET));
- b2->s.k = 0x01; /* To DS */
- b2->stmts = s;
- gen_and(b1, b2);
+ gen_not(b1);
/*
- * Test the DA at 16, and OR the previous DA tests
- * with it.
+ * AND that with the checks for data and management
+ * frames.
*/
- b1 = gen_mac_multicast(16);
- gen_and(b2, b1);
- gen_or(b3, b1);
-
- gen_and(b0, b1);
- return b1;
+ gen_and(b1, b0);
+ return b0;
}
/* Link not known to support multicasts */
projects / libpcap / commitdiff
