Add comment match extension (Brad Fisher)

1 files changed, 127 insertions, 0 deletions

diff --git a/extensions/libipt_comment.c b/extensions/libipt_comment.c
new file mode 100644
index 00000000..778051e8
--- /dev/null
+++ b/extensions/libipt_comment.c
@@ -0,0 +1,127 @@
+/* Shared library add-on to iptables to add comment match support.
+ *
+ * ChangeLog
+ *     2003-05-13: Brad Fisher <brad@info-link.net>
+ *         Initial comment match
+ *     2004-05-12: Brad Fisher <brad@info-link.net>
+ *         Port to patch-o-matic-ng
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdlib.h>
+#include <getopt.h>
+
+#include <iptables.h>
+#include <linux/netfilter_ipv4/ipt_comment.h>
+
+/* Function which prints out usage message. */
+static void
+help(void)
+{
+	printf(
+		"COMMENT match options:\n"
+		"--comment COMMENT             Attach a comment to a rule\n\n"
+		);
+}
+
+static struct option opts[] = {
+	{ "comment", 1, 0, '1' },
+	{0}
+};
+
+/* Initialize the match. */
+static void
+init(struct ipt_entry_match *m, unsigned int *nfcache)
+{
+	*nfcache |= NFC_UNKNOWN;
+}
+
+static void
+parse_comment(const unsigned char *s, struct ipt_comment_info *info)
+{	
+	int slen = strlen(s);
+
+	if (slen >= IPT_MAX_COMMENT_LEN) {
+		exit_error(PARAMETER_PROBLEM,
+			"COMMENT must be shorter than %i characters", IPT_MAX_COMMENT_LEN);
+	}
+	strcpy(info->comment, s);
+}
+
+/* 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_comment_info *commentinfo = (struct ipt_comment_info *)(*match)->data;
+
+	switch (c) {
+	case '1':
+		check_inverse(argv[optind-1], &invert, &optind, 0);
+		if (invert) {
+			exit_error(PARAMETER_PROBLEM,
+					"Sorry, you can't have an inverted comment");
+		}
+		parse_comment(argv[optind-1], commentinfo);
+		*flags = 1;
+		break;
+
+	default:
+		return 0;
+	}
+	return 1;
+}
+
+/* Final check; must have specified --comment. */
+static void
+final_check(unsigned int flags)
+{
+	if (!flags)
+		exit_error(PARAMETER_PROBLEM,
+			   "COMMENT match: You must specify `--comment'");
+}
+
+/* Prints out the matchinfo. */
+static void
+print(const struct ipt_ip *ip,
+      const struct ipt_entry_match *match,
+      int numeric)
+{
+	struct ipt_comment_info *commentinfo = (struct ipt_comment_info *)match->data;
+
+	commentinfo->comment[IPT_MAX_COMMENT_LEN-1] = '\0';
+	printf("/* %s */ ", commentinfo->comment);
+}
+
+/* Saves the union ipt_matchinfo in parsable form to stdout. */
+static void
+save(const struct ipt_ip *ip, const struct ipt_entry_match *match)
+{
+	struct ipt_comment_info *commentinfo = (struct ipt_comment_info *)match->data;
+
+	commentinfo->comment[IPT_MAX_COMMENT_LEN-1] = '\0';
+	printf("--comment \"%s\" ", commentinfo->comment);
+}
+
+static struct iptables_match comment = {
+    NULL,
+    "comment",
+    IPTABLES_VERSION,
+    IPT_ALIGN(sizeof(struct ipt_comment_info)),
+    IPT_ALIGN(sizeof(struct ipt_comment_info)),
+    &help,
+    &init,
+    &parse,
+    &final_check,
+    &print,
+    &save,
+    opts
+};
+
+void _init(void)
+{
+	register_match(&comment);
+}