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![Jan Engelhardt](/assets/img/avatar_default.png)
This patch does this for target extensions' destroy functions. Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: Patrick McHardy <kaber@trash.net>
146 lines
3.3 KiB
C
146 lines
3.3 KiB
C
/*
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* Module for modifying the secmark field of the skb, for use by
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* security subsystems.
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*
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* Based on the nfmark match by:
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* (C) 1999-2001 Marc Boucher <marc@mbsi.ca>
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*
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* (C) 2006,2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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*/
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#include <linux/module.h>
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#include <linux/skbuff.h>
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#include <linux/selinux.h>
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#include <linux/netfilter/x_tables.h>
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#include <linux/netfilter/xt_SECMARK.h>
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("James Morris <jmorris@redhat.com>");
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MODULE_DESCRIPTION("Xtables: packet security mark modification");
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MODULE_ALIAS("ipt_SECMARK");
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MODULE_ALIAS("ip6t_SECMARK");
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#define PFX "SECMARK: "
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static u8 mode;
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static unsigned int
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secmark_tg(struct sk_buff *skb, const struct xt_target_param *par)
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{
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u32 secmark = 0;
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const struct xt_secmark_target_info *info = par->targinfo;
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BUG_ON(info->mode != mode);
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switch (mode) {
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case SECMARK_MODE_SEL:
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secmark = info->u.sel.selsid;
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break;
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default:
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BUG();
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}
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skb->secmark = secmark;
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return XT_CONTINUE;
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}
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static bool checkentry_selinux(struct xt_secmark_target_info *info)
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{
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int err;
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struct xt_secmark_target_selinux_info *sel = &info->u.sel;
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sel->selctx[SECMARK_SELCTX_MAX - 1] = '\0';
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err = selinux_string_to_sid(sel->selctx, &sel->selsid);
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if (err) {
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if (err == -EINVAL)
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printk(KERN_INFO PFX "invalid SELinux context \'%s\'\n",
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sel->selctx);
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return false;
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}
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if (!sel->selsid) {
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printk(KERN_INFO PFX "unable to map SELinux context \'%s\'\n",
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sel->selctx);
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return false;
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}
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err = selinux_secmark_relabel_packet_permission(sel->selsid);
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if (err) {
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printk(KERN_INFO PFX "unable to obtain relabeling permission\n");
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return false;
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}
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selinux_secmark_refcount_inc();
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return true;
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}
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static bool secmark_tg_check(const struct xt_tgchk_param *par)
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{
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struct xt_secmark_target_info *info = par->targinfo;
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if (strcmp(par->table, "mangle") != 0 &&
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strcmp(par->table, "security") != 0) {
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printk(KERN_INFO PFX "target only valid in the \'mangle\' "
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"or \'security\' tables, not \'%s\'.\n", par->table);
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return false;
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}
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if (mode && mode != info->mode) {
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printk(KERN_INFO PFX "mode already set to %hu cannot mix with "
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"rules for mode %hu\n", mode, info->mode);
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return false;
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}
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switch (info->mode) {
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case SECMARK_MODE_SEL:
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if (!checkentry_selinux(info))
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return false;
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break;
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default:
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printk(KERN_INFO PFX "invalid mode: %hu\n", info->mode);
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return false;
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}
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if (!mode)
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mode = info->mode;
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return true;
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}
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static void secmark_tg_destroy(const struct xt_tgdtor_param *par)
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{
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switch (mode) {
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case SECMARK_MODE_SEL:
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selinux_secmark_refcount_dec();
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}
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}
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static struct xt_target secmark_tg_reg __read_mostly = {
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.name = "SECMARK",
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.revision = 0,
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.family = NFPROTO_UNSPEC,
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.checkentry = secmark_tg_check,
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.destroy = secmark_tg_destroy,
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.target = secmark_tg,
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.targetsize = sizeof(struct xt_secmark_target_info),
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.me = THIS_MODULE,
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};
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static int __init secmark_tg_init(void)
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{
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return xt_register_target(&secmark_tg_reg);
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}
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static void __exit secmark_tg_exit(void)
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{
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xt_unregister_target(&secmark_tg_reg);
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}
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module_init(secmark_tg_init);
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module_exit(secmark_tg_exit);
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