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- /*
- * 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 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.
- *
- */
- #include <linux/module.h>
- #include <linux/skbuff.h>
- #include <linux/selinux.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("ip[6]tables SECMARK modification module");
- MODULE_ALIAS("ipt_SECMARK");
- MODULE_ALIAS("ip6t_SECMARK");
- #define PFX "SECMARK: "
- static u8 mode;
- static unsigned int target(struct sk_buff **pskb, const struct net_device *in,
- const struct net_device *out, unsigned int hooknum,
- const struct xt_target *target,
- const void *targinfo)
- {
- u32 secmark = 0;
- const struct xt_secmark_target_info *info = targinfo;
- BUG_ON(info->mode != mode);
- switch (mode) {
- case SECMARK_MODE_SEL:
- secmark = info->u.sel.selsid;
- break;
- default:
- BUG();
- }
- (*pskb)->secmark = secmark;
- return XT_CONTINUE;
- }
- static int checkentry_selinux(struct xt_secmark_target_info *info)
- {
- int err;
- struct xt_secmark_target_selinux_info *sel = &info->u.sel;
- sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0';
- err = selinux_string_to_sid(sel->selctx, &sel->selsid);
- if (err) {
- if (err == -EINVAL)
- printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n",
- sel->selctx);
- return 0;
- }
- if (!sel->selsid) {
- printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
- sel->selctx);
- return 0;
- }
- err = selinux_relabel_packet_permission(sel->selsid);
- if (err) {
- printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
- return 0;
- }
- return 1;
- }
- static int checkentry(const char *tablename, const void *entry,
- const struct xt_target *target, void *targinfo,
- unsigned int hook_mask)
- {
- struct xt_secmark_target_info *info = targinfo;
- if (mode && mode != info->mode) {
- printk(KERN_INFO PFX "mode already set to %hu cannot mix with "
- "rules for mode %hu\n", mode, info->mode);
- return 0;
- }
- switch (info->mode) {
- case SECMARK_MODE_SEL:
- if (!checkentry_selinux(info))
- return 0;
- break;
- default:
- printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
- return 0;
- }
- if (!mode)
- mode = info->mode;
- return 1;
- }
- static struct xt_target xt_secmark_target[] = {
- {
- .name = "SECMARK",
- .family = AF_INET,
- .checkentry = checkentry,
- .target = target,
- .targetsize = sizeof(struct xt_secmark_target_info),
- .table = "mangle",
- .me = THIS_MODULE,
- },
- {
- .name = "SECMARK",
- .family = AF_INET6,
- .checkentry = checkentry,
- .target = target,
- .targetsize = sizeof(struct xt_secmark_target_info),
- .table = "mangle",
- .me = THIS_MODULE,
- },
- };
- static int __init xt_secmark_init(void)
- {
- return xt_register_targets(xt_secmark_target,
- ARRAY_SIZE(xt_secmark_target));
- }
- static void __exit xt_secmark_fini(void)
- {
- xt_unregister_targets(xt_secmark_target, ARRAY_SIZE(xt_secmark_target));
- }
- module_init(xt_secmark_init);
- module_exit(xt_secmark_fini);
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