Support american fuzzy lop

When built with AFL_MODE set to true, whois will use the first line of
standard input as command line parameters and the rest as network input.

Makefile

@@ -96,6 +96,19 @@ tld_serv.h: tld_serv_list make_tld_serv.pl
 servers_charset.h: servers_charset_list make_servers_charset.pl
 	$(PERL) make_servers_charset.pl < $< > $@
 
+##############################################################################
+afl:
+	$(MAKE) whois \
+		CC=afl-gcc AFL_HARDEN=1 \
+		HAVE_LIBIDN=1 HAVE_ICONV=1 DEFS=-DAFL_MODE=1
+
+afl2:
+	$(MAKE) whois \
+		HAVE_LIBIDN=1 HAVE_ICONV=1 DEFS=-DAFL_MODE=1
+
+afl-run:
+	nice afl-fuzz -i ../afl_in -o ../afl_out -- ./whois
+
 ##############################################################################
 install: install-whois install-mkpasswd install-pos
 

utils.h

@@ -9,6 +9,10 @@
 
 #define NOFAIL(ptr) do_nofail((ptr), __FILE__, __LINE__)
 
+#ifndef AFL_MODE
+# define AFL_MODE 0
+#endif
+
 /* Portability macros */
 #ifdef __GNUC__
 # define NORETURN __attribute__((noreturn))

whois.c

@@ -140,6 +140,20 @@ int main(int argc, char *argv[])
     fstring = malloc(fstringlen + 1);
     *fstring = '\0';
 
+    /* interface for American Fuzzy Lop */
+    if (AFL_MODE) {
+	FILE *fp = fdopen(0, "r");
+	char *buf = NULL;
+	size_t len = 0;
+
+	/* read one line from stdin */
+	if (getline(&buf, &len, fp) < 0)
+	    err_sys("getline");
+	fflush(fp);
+	/* and use it as command line arguments */
+	argv = merge_args(buf, argv, &argc);
+    }
+
     /* prepend options from environment */
     argv = merge_args(getenv("WHOIS_OPTIONS"), argv, &argc);
 
@@ -907,6 +921,13 @@ int openconn(const char *server, const char *port)
     struct sockaddr_in saddr;
 #endif
 
+    /*
+     * When using American Fuzzy Lop get the data from it using stdin
+     * instead of connecting to the actual whois server.
+     */
+    if (AFL_MODE)
+	return (dup(0));
+
     alarm(60);
 
 #ifdef HAVE_GETADDRINFO