Init

usr.etc/etherfind/parse.c

@@ -0,0 +1,305 @@
+/*
+ * Filter parsing module for the "Etherfind" program
+ *
+ * @(#)parse.c 1.1 94/10/31
+ *
+ * Copyright (c) 1988 by Sun Microsystems, Inc.
+ */
+
+#include <stdio.h>
+#include <ctype.h>
+
+#include <sys/types.h>
+
+#include "etherfind.h"
+
+char	**Argv;
+int	Argc,
+	Ai;
+
+struct	anode	*exp(),
+		*e1(),
+		*e2(),
+		*e3(),
+		*mk();
+
+char	*nxtarg();
+
+extern char *index();
+extern char *strcpy();
+extern char *malloc();
+extern char *sprintf();
+
+struct colon *strtocolon();
+struct addrpair *stringtoaddrpair();
+
+int Randlast;
+
+struct anode Node[100];
+int Nn;  /* number of nodes */
+
+/*
+ * Return true if the given string matches, modulo an optional "-"
+ */
+EQ(x, y)
+    char *x, *y;
+{
+	if (*x == '-')
+		x++;
+	return(strcmp(x, y)==0);
+}
+
+
+/* 
+ * convert a:b to a struct colon
+ */
+struct colon *
+strtocolon(str)
+	char *str;
+{
+	char *p, *ntoi();
+	struct colon *colonp;
+	
+	colonp = (struct colon *)malloc(sizeof(colon));
+	p = ntoi(str, &colonp->byte);
+	colonp->op = *p++;
+	(void) ntoi(p, (int *)&colonp->value);
+	return (colonp);
+}
+
+char *
+ntoi(cp, valp)
+	char *cp;
+	int *valp;
+{
+	register val, base, c;
+	
+	val = 0; base = 10;
+	if (*cp == '0')
+		base = 8, cp++;
+	if (*cp == 'x' || *cp == 'X')
+		base = 16, cp++;
+	while (c = *cp) {
+		if (isdigit(c)) {
+			val = (val * base) + (c - '0');
+			cp++;
+			continue;
+		}
+		if (base == 16 && isxdigit(c)) {
+			val = (val << 4) + (c + 10 - (islower(c) ? 'a' : 'A'));
+			cp++;
+			continue;
+		}
+		break;
+	}
+	*valp = val;
+	return (cp);
+}
+
+
+/*
+ *  convert two strings to an addrpair
+ */
+struct addrpair *
+stringtoaddrpair(str1, str2)
+	char *str1, *str2;
+{
+	struct addrpair *p;
+	
+	p = (struct addrpair *)malloc(sizeof(struct addrpair));
+	p->addr1 = stringtoaddr(str1);
+	p->addr2 = stringtoaddr(str2);
+	return (p);
+}
+
+parseargs(argc, argv)
+	char *argv[];
+{
+
+	Argc = argc; Argv = argv;
+	Ai = 1;
+	if (!(exlist[0] = exp())) { /* parse and compile the arguments */
+		fprintf(stderr, "etherfind: parsing error\n");
+		exit(1);
+	}
+}
+
+/* compile time functions:  priority is  exp()<e1()<e2()<e3()  */
+
+struct anode *
+exp()		/* parse ALTERNATION (or)  */
+{
+	int or();
+	register struct anode * p1;
+	char *a;
+
+	p1 = e1() /* get left operand */ ;
+	a = nxtarg();
+	if (EQ(a, "or") || EQ(a, "o")) {
+		Randlast--;
+		return(mk(or, p1, exp()));
+	}
+	else if (Ai <= Argc) --Ai;
+	return(p1);
+}
+
+struct anode *
+e1() { /* parse CONCATENATION (formerly -a) */
+	int and();
+	register struct anode * p1;
+	register char *a;
+
+	p1 = e2();
+	a = nxtarg();
+	if (EQ(a, "and") || EQ(a, "a")) {
+And:
+		Randlast--;
+		return(mk(and, p1, e1()));
+	} else if (EQ(a, "(") || EQ(a, "!") || EQ(a, "not") ||
+	          ( *a != NULL && !EQ(a, "or") && !EQ(a, "o"))) {
+		--Ai;
+		goto And;
+	} else if (Ai <= Argc) --Ai;
+	return(p1);
+}
+
+struct anode *
+e2()		/* parse NOT (!) */
+{
+	int not();
+	char *a;
+
+	if (Randlast) {
+		fprintf(stderr, "etherfind: operand follows operand\n");
+		exit(1);
+	}
+	Randlast++;
+	a = nxtarg();
+	if (EQ(a, "!") || EQ(a, "not"))
+		return(mk(not, e3(), (struct anode *)0));
+	else if (Ai <= Argc) --Ai;
+	return(e3());
+}
+
+struct anode *
+e3()		/* parse parens and predicates */
+{
+	int src(), dst(), srcnet(), dstnet(), less(), greater(), proto(),
+	    tcp(), udp(), rpc(), nfs(),
+	    src_port(), dst_port(), byte(), between(), host(),
+	    broadcast(), arp(), rarp(), ip(), decnet(), apple();
+	struct anode *p1;
+	register char *a, *b, *c, s;
+
+	a = nxtarg();
+	if (EQ(a, "(")) {
+		Randlast--;
+		p1 = exp();
+		a = nxtarg();
+		if (!EQ(a, ")")) goto err;
+		return(p1);
+	}
+	else if (EQ(a, "broadcast"))
+		return(mk(broadcast, (struct anode *)0, (struct anode *)0));
+	else if (EQ(a, "arp"))
+		return(mk(arp, (struct anode *)0, (struct anode *)0));
+	else if (EQ(a, "rarp"))
+		return(mk(rarp, (struct anode *)0, (struct anode *)0));
+	else if (EQ(a, "ip"))
+		return(mk(ip, (struct anode *)0, (struct anode *)0));
+	else if (EQ(a, "decnet"))
+		return(mk(decnet, (struct anode *)0, (struct anode *)0));
+	else if (EQ(a, "apple"))
+		return(mk(apple, (struct anode *)0, (struct anode *)0));
+	b = nxtarg();
+	s = *b;
+	if (s=='+')
+		b++;
+	if (EQ(a, "proto"))
+		return(mk(proto, (struct anode *)getproto(b),
+		    (struct anode *)s));
+	else if (EQ(a, "src"))
+		return(mk(src, (struct anode *)stringtoaddr(b),
+		    (struct anode *)s));
+	else if (EQ(a, "dst"))
+		return(mk(dst, (struct anode *)stringtoaddr(b),
+		    (struct anode *)s));
+	else if (EQ(a, "dstnet"))
+		return(mk(dstnet, (struct anode *)stringtonetaddr(b),
+		    (struct anode *)s));
+	else if (EQ(a, "srcnet"))
+		return(mk(srcnet, (struct anode *)stringtonetaddr(b),
+		    (struct anode *)s));
+	else if (EQ(a, "srcport"))
+		return(mk(src_port, (struct anode *)stringtoport(b),
+		    (struct anode *)s));
+	else if (EQ(a, "dstport"))
+		return(mk(dst_port, (struct anode *)stringtoport(b),
+		    (struct anode *)s));
+	else if (EQ(a, "greater"))
+		return(mk(greater, (struct anode *)atoi(b),
+		    (struct anode *)s));
+	else if (EQ(a, "less"))
+		return(mk(less, (struct anode *)atoi(b), (struct anode *)s));
+	else if (EQ(a, "byte"))
+		return(mk(byte,(struct anode *)strtocolon(b),
+		    (struct anode *)s));
+	else if (EQ(a, "between")) {
+		c = nxtarg();
+		return(mk(between, (struct anode *)stringtoaddrpair(b, c),
+		    (struct anode *)s));
+	}
+	else if (EQ(a, "host"))
+		return(mk(host, (struct anode *)stringtoaddr(b),
+		    (struct anode *)s));
+err:	fprintf(stderr, "etherfind: bad option or expression < %s >\n", a);
+	usage();
+	exit(1);
+	/*NOTREACHED*/
+}
+
+
+struct anode *
+mk(f, l, r)
+	int (*f)();
+	struct anode *l, *r;
+{
+	Node[Nn].F = f;
+	Node[Nn].L = l;
+	Node[Nn].R = r;
+	return(&(Node[Nn++]));
+}
+
+char *
+nxtarg()			/* get next arg from command line */
+{
+	static strikes = 0;
+
+	if (strikes==3) {
+		fprintf(stderr, "etherfind: incomplete statement\n");
+		usage();
+		exit(1);
+	}
+	if (Ai>=Argc) {
+		strikes++;
+		Ai = Argc + 1;
+		return("");
+	}
+	return(Argv[Ai++]);
+}
+
+usage()
+{
+	fprintf(stderr,
+"Usage: etherfind [-d] [-n] [-p] [-r] [-t] [-u] [-v] [-x]\n");
+	fprintf(stderr,
+"	[-i interface] [-c cnt] [-l length] expression\n");
+	fprintf(stderr,
+"expressions are:\n");
+	fprintf(stderr,
+"       broadcast arp rarp ip decnet apple\n");
+	fprintf(stderr, 
+"       dst src dstnet srcnet less greater proto srcport dstport byte\n");
+	fprintf(stderr, 
+"       between host and or not\n");
+}