1 files changed, 147 insertions, 0 deletions
diff --git a/net/netfilter/xt_SECMARK.c b/net/netfilter/xt_SECMARK.c
new file mode 100644
index 00000000..9faf5e05
--- /dev/null
+++ b/net/netfilter/xt_SECMARK.c
@@ -0,0 +1,147 @@
+/*
+ * Module for modifying the secmark field of the skb, for use by
+ * security subsystems.
+ *
+ * Based on the nfmark match by:
+ * (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
+ *
+ * (C) 2006,2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/module.h>
+#include <linux/security.h>
+#include <linux/skbuff.h>
+#include <linux/netfilter/x_tables.h>
+#include <linux/netfilter/xt_SECMARK.h>
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
+MODULE_DESCRIPTION("Xtables: packet security mark modification");
+MODULE_ALIAS("ipt_SECMARK");
+MODULE_ALIAS("ip6t_SECMARK");
+
+#define PFX "SECMARK: "
+
+static u8 mode;
+
+static unsigned int
+secmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
+{
+	u32 secmark = 0;
+	const struct xt_secmark_target_info *info = par->targinfo;
+
+	BUG_ON(info->mode != mode);
+
+	switch (mode) {
+	case SECMARK_MODE_SEL:
+		secmark = info->secid;
+		break;
+	default:
+		BUG();
+	}
+
+	skb->secmark = secmark;
+	return XT_CONTINUE;
+}
+
+static int checkentry_lsm(struct xt_secmark_target_info *info)
+{
+	int err;
+
+	info->secctx[SECMARK_SECCTX_MAX - 1] = '\0';
+	info->secid = 0;
+
+	err = security_secctx_to_secid(info->secctx, strlen(info->secctx),
+				       &info->secid);
+	if (err) {
+		if (err == -EINVAL)
+			pr_info("invalid security context \'%s\'\n", info->secctx);
+		return err;
+	}
+
+	if (!info->secid) {
+		pr_info("unable to map security context \'%s\'\n", info->secctx);
+		return -ENOENT;
+	}
+
+	err = security_secmark_relabel_packet(info->secid);
+	if (err) {
+		pr_info("unable to obtain relabeling permission\n");
+		return err;
+	}
+
+	security_secmark_refcount_inc();
+	return 0;
+}
+
+static int secmark_tg_check(const struct xt_tgchk_param *par)
+{
+	struct xt_secmark_target_info *info = par->targinfo;
+	int err;
+
+	if (strcmp(par->table, "mangle") != 0 &&
+	    strcmp(par->table, "security") != 0) {
+		pr_info("target only valid in the \'mangle\' "
+			"or \'security\' tables, not \'%s\'.\n", par->table);
+		return -EINVAL;
+	}
+
+	if (mode && mode != info->mode) {
+		pr_info("mode already set to %hu cannot mix with "
+			"rules for mode %hu\n", mode, info->mode);
+		return -EINVAL;
+	}
+
+	switch (info->mode) {
+	case SECMARK_MODE_SEL:
+		break;
+	default:
+		pr_info("invalid mode: %hu\n", info->mode);
+		return -EINVAL;
+	}
+
+	err = checkentry_lsm(info);
+	if (err)
+		return err;
+
+	if (!mode)
+		mode = info->mode;
+	return 0;
+}
+
+static void secmark_tg_destroy(const struct xt_tgdtor_param *par)
+{
+	switch (mode) {
+	case SECMARK_MODE_SEL:
+		security_secmark_refcount_dec();
+	}
+}
+
+static struct xt_target secmark_tg_reg __read_mostly = {
+	.name       = "SECMARK",
+	.revision   = 0,
+	.family     = NFPROTO_UNSPEC,
+	.checkentry = secmark_tg_check,
+	.destroy    = secmark_tg_destroy,
+	.target     = secmark_tg,
+	.targetsize = sizeof(struct xt_secmark_target_info),
+	.me         = THIS_MODULE,
+};
+
+static int __init secmark_tg_init(void)
+{
+	return xt_register_target(&secmark_tg_reg);
+}
+
+static void __exit secmark_tg_exit(void)
+{
+	xt_unregister_target(&secmark_tg_reg);
+}
+
+module_init(secmark_tg_init);
+module_exit(secmark_tg_exit);