u32 match added
diff --git a/extensions/.u32-test b/extensions/.u32-test
new file mode 100755
index 0000000..77d8a00
--- /dev/null
+++ b/extensions/.u32-test
@@ -0,0 +1,3 @@
+#!/bin/sh
+# True if u32 is applied.
+[ -f $KERNEL_DIR/include/linux/netfilter_ipv4/ipt_u32.h ] && echo u32
diff --git a/extensions/libipt_u32.c b/extensions/libipt_u32.c
new file mode 100644
index 0000000..788413c
--- /dev/null
+++ b/extensions/libipt_u32.c
@@ -0,0 +1,272 @@
+/* Shared library add-on to iptables to add u32 matching,
+ * generalized matching on values found at packet offsets
+ *
+ * Detailed doc is in the kernel module source
+ * net/ipv4/netfilter/ipt_u32.c
+ *
+ * (C) 2002 by Don Cohen <don-netf@isis.cs3-inc.com>
+ * Released under the terms of GNU GPL v2
+ */
+#include <stdio.h>
+#include <netdb.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ipt_u32.h>
+#include <errno.h>
+#include <ctype.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+ printf( "u32 v%s options:\n"
+ " --u32 tests\n"
+ " tests := location = value | tests && location = value\n"
+ " value := range | value , range\n"
+ " range := number | number : number\n"
+ " location := number | location operator number\n"
+ " operator := & | << | >> | @\n"
+ ,IPTABLES_VERSION);
+}
+
+/* defined in /usr/include/getopt.h maybe in man getopt */
+static struct option opts[] = {
+ { "u32", 1, 0, '1' },
+ { 0 }
+};
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+ *nfcache |= NFC_UNKNOWN;
+}
+
+/* shared printing code */
+static void print_u32(struct ipt_u32 *data)
+{
+ unsigned int testind;
+
+ for (testind=0; testind < data->ntests; testind++) {
+ if (testind) printf("&&");
+ {
+ unsigned int i;
+
+ printf("0x%x", data->tests[testind].location[0].number);
+ for (i = 1; i < data->tests[testind].nnums; i++) {
+ switch (data->tests[testind].location[i].nextop) {
+ case IPT_U32_AND: printf("&"); break;
+ case IPT_U32_LEFTSH: printf("<<"); break;
+ case IPT_U32_RIGHTSH: printf(">>"); break;
+ case IPT_U32_AT: printf("@"); break;
+ }
+ printf("0x%x", data->tests[testind].location[i].number);
+ }
+ printf("=");
+ for (i = 0; i < data->tests[testind].nvalues; i++) {
+ if (i) printf(",");
+ if (data->tests[testind].value[i].min
+ == data->tests[testind].value[i].max)
+ printf("0x%x", data->tests[testind].value[i].min);
+ else printf("0x%x:0x%x", data->tests[testind].value[i].min,
+ data->tests[testind].value[i].max);
+ }
+ }
+ }
+ printf(" ");
+}
+
+/* string_to_number is not quite what we need here ... */
+u_int32_t parse_number(char **s, int pos)
+{
+ u_int32_t number;
+ char *end;
+ errno = 0;
+
+ number = strtol(*s, &end, 0);
+ if (end == *s)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d expected number", pos);
+ if (errno)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d error reading number", pos);
+ *s = end;
+ return number;
+}
+
+/* Function which parses command options; returns true if it ate an option */
+static int
+parse(int c, char **argv, int invert, unsigned int *flags,
+ const struct ipt_entry *entry,
+ unsigned int *nfcache,
+ struct ipt_entry_match **match)
+{
+ struct ipt_u32 *data = (struct ipt_u32 *)(*match)->data;
+ char *arg = argv[optind-1]; /* the argument string */
+ char *start = arg;
+ int state=0, testind=0, locind=0, valind=0;
+
+ if (c != '1') return 0;
+ /* states: 0 = looking for numbers and operations, 1 = looking for ranges */
+ while (1) { /* read next operand/number or range */
+ while (isspace(*arg))
+ arg++; /* skip white space */
+ if (! *arg) { /* end of argument found */
+ if (state == 0)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: input ended in location spec");
+ if (valind == 0)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: test ended with no value spec");
+ data->tests[testind].nnums = locind;
+ data->tests[testind].nvalues = valind;
+ testind++;
+ data->ntests=testind;
+ if (testind > U32MAXSIZE)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d too many &&'s",
+ arg-start);
+ /* debugging
+ print_u32(data);printf("\n");
+ exit_error(PARAMETER_PROBLEM, "debugging output done"); */
+ return 1;
+ }
+ if (state == 0) {
+ /* reading location: read a number if nothing read yet,
+ otherwise either op number or = to end location spec */
+ if (*arg == '=') {
+ if (locind == 0)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d location spec missing", arg-start);
+ else {
+ arg++;
+ state=1;
+ }
+ }
+ else {
+ if (locind) { /* need op before number */
+ if (*arg == '&') {
+ data->tests[testind].location[locind].nextop = IPT_U32_AND;
+ }
+ else if (*arg == '<') {
+ arg++;
+ if (*arg != '<')
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d a second < expected", arg-start);
+ data->tests[testind].location[locind].nextop = IPT_U32_LEFTSH;
+ }
+ else if (*arg == '>') {
+ arg++;
+ if (*arg != '>')
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d a second > expected", arg-start);
+ data->tests[testind].location[locind].nextop = IPT_U32_RIGHTSH;
+ }
+ else if (*arg == '@') {
+ data->tests[testind].location[locind].nextop = IPT_U32_AT;
+ }
+ else exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d operator expected", arg-start);
+ arg++;
+ }
+ /* now a number; string_to_number skips white space? */
+ data->tests[testind].location[locind].number =
+ parse_number(&arg, arg-start);
+ locind++;
+ if (locind > U32MAXSIZE)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d too many operators", arg-start);
+ }
+ }
+ else {
+ /* state 1 - reading values: read a range if nothing read yet,
+ otherwise either ,range or && to end test spec */
+ if (*arg == '&') {
+ arg++;
+ if (*arg != '&')
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d a second & expected", arg-start);
+ if (valind == 0)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d value spec missing", arg-start);
+ else {
+ data->tests[testind].nnums = locind;
+ data->tests[testind].nvalues = valind;
+ testind++;
+ if (testind > U32MAXSIZE)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d too many &&'s", arg-start);
+ arg++; state=0; locind=0; valind=0;
+ }
+ }
+ else { /* read value range */
+ if (valind) { /* need , before number */
+ if (*arg != ',')
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d expected , or &&", arg-start);
+ arg++;
+ }
+ data->tests[testind].value[valind].min = parse_number(&arg, arg-start);
+ while (isspace(*arg))
+ arg++; /* another place white space could be */
+ if (*arg==':') {
+ arg++;
+ data->tests[testind].value[valind].max
+ = parse_number(&arg, arg-start);
+ }
+ else data->tests[testind].value[valind].max
+ = data->tests[testind].value[valind].min;
+ valind++;
+ if (valind > U32MAXSIZE)
+ exit_error(PARAMETER_PROBLEM,
+ "u32: at char %d too many ,'s", arg-start);
+ }
+ }
+ }
+}
+
+/* Final check; must specify something. */
+static void
+final_check(unsigned int flags)
+{
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+ const struct ipt_entry_match *match,
+ int numeric)
+{
+ printf("u32 ");
+ print_u32((struct ipt_u32 *)match->data);
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+ printf("--u32 ");
+ print_u32((struct ipt_u32 *)match->data);
+}
+
+struct iptables_match u32
+= { NULL,
+ "u32",
+ IPTABLES_VERSION,
+ IPT_ALIGN(sizeof(struct ipt_u32)),
+ IPT_ALIGN(sizeof(struct ipt_u32)),
+ &help,
+ &init,
+ &parse,
+ &final_check,
+ &print,
+ &save,
+ opts
+};
+
+void
+_init(void)
+{
+ register_match(&u32);
+}