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- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * xt_connmark - Netfilter module to operate on connection marks
- *
- * Copyright (C) 2002,2004 MARA Systems AB <https://www.marasystems.com>
- * by Henrik Nordstrom <hno@marasystems.com>
- * Copyright © CC Computer Consultants GmbH, 2007 - 2008
- * Jan Engelhardt <jengelh@medozas.de>
- */
- #include <linux/module.h>
- #include <linux/skbuff.h>
- #include <net/netfilter/nf_conntrack.h>
- #include <net/netfilter/nf_conntrack_ecache.h>
- #include <linux/netfilter/x_tables.h>
- #include <linux/netfilter/xt_connmark.h>
- MODULE_AUTHOR("Henrik Nordstrom <hno@marasystems.com>");
- MODULE_DESCRIPTION("Xtables: connection mark operations");
- MODULE_LICENSE("GPL");
- MODULE_ALIAS("ipt_CONNMARK");
- MODULE_ALIAS("ip6t_CONNMARK");
- MODULE_ALIAS("ipt_connmark");
- MODULE_ALIAS("ip6t_connmark");
- static unsigned int
- connmark_tg_shift(struct sk_buff *skb, const struct xt_connmark_tginfo2 *info)
- {
- enum ip_conntrack_info ctinfo;
- u_int32_t new_targetmark;
- struct nf_conn *ct;
- u_int32_t newmark;
- ct = nf_ct_get(skb, &ctinfo);
- if (ct == NULL)
- return XT_CONTINUE;
- switch (info->mode) {
- case XT_CONNMARK_SET:
- newmark = (ct->mark & ~info->ctmask) ^ info->ctmark;
- if (info->shift_dir == D_SHIFT_RIGHT)
- newmark >>= info->shift_bits;
- else
- newmark <<= info->shift_bits;
- if (ct->mark != newmark) {
- ct->mark = newmark;
- nf_conntrack_event_cache(IPCT_MARK, ct);
- }
- break;
- case XT_CONNMARK_SAVE:
- new_targetmark = (skb->mark & info->nfmask);
- if (info->shift_dir == D_SHIFT_RIGHT)
- new_targetmark >>= info->shift_bits;
- else
- new_targetmark <<= info->shift_bits;
- newmark = (ct->mark & ~info->ctmask) ^
- new_targetmark;
- if (ct->mark != newmark) {
- ct->mark = newmark;
- nf_conntrack_event_cache(IPCT_MARK, ct);
- }
- break;
- case XT_CONNMARK_RESTORE:
- new_targetmark = (ct->mark & info->ctmask);
- if (info->shift_dir == D_SHIFT_RIGHT)
- new_targetmark >>= info->shift_bits;
- else
- new_targetmark <<= info->shift_bits;
- newmark = (skb->mark & ~info->nfmask) ^
- new_targetmark;
- skb->mark = newmark;
- break;
- }
- return XT_CONTINUE;
- }
- static unsigned int
- connmark_tg(struct sk_buff *skb, const struct xt_action_param *par)
- {
- const struct xt_connmark_tginfo1 *info = par->targinfo;
- const struct xt_connmark_tginfo2 info2 = {
- .ctmark = info->ctmark,
- .ctmask = info->ctmask,
- .nfmask = info->nfmask,
- .mode = info->mode,
- };
- return connmark_tg_shift(skb, &info2);
- }
- static unsigned int
- connmark_tg_v2(struct sk_buff *skb, const struct xt_action_param *par)
- {
- const struct xt_connmark_tginfo2 *info = par->targinfo;
- return connmark_tg_shift(skb, info);
- }
- static int connmark_tg_check(const struct xt_tgchk_param *par)
- {
- int ret;
- ret = nf_ct_netns_get(par->net, par->family);
- if (ret < 0)
- pr_info_ratelimited("cannot load conntrack support for proto=%u\n",
- par->family);
- return ret;
- }
- static void connmark_tg_destroy(const struct xt_tgdtor_param *par)
- {
- nf_ct_netns_put(par->net, par->family);
- }
- static bool
- connmark_mt(const struct sk_buff *skb, struct xt_action_param *par)
- {
- const struct xt_connmark_mtinfo1 *info = par->matchinfo;
- enum ip_conntrack_info ctinfo;
- const struct nf_conn *ct;
- ct = nf_ct_get(skb, &ctinfo);
- if (ct == NULL)
- return false;
- return ((ct->mark & info->mask) == info->mark) ^ info->invert;
- }
- static int connmark_mt_check(const struct xt_mtchk_param *par)
- {
- int ret;
- ret = nf_ct_netns_get(par->net, par->family);
- if (ret < 0)
- pr_info_ratelimited("cannot load conntrack support for proto=%u\n",
- par->family);
- return ret;
- }
- static void connmark_mt_destroy(const struct xt_mtdtor_param *par)
- {
- nf_ct_netns_put(par->net, par->family);
- }
- static struct xt_target connmark_tg_reg[] __read_mostly = {
- {
- .name = "CONNMARK",
- .revision = 1,
- .family = NFPROTO_UNSPEC,
- .checkentry = connmark_tg_check,
- .target = connmark_tg,
- .targetsize = sizeof(struct xt_connmark_tginfo1),
- .destroy = connmark_tg_destroy,
- .me = THIS_MODULE,
- },
- {
- .name = "CONNMARK",
- .revision = 2,
- .family = NFPROTO_UNSPEC,
- .checkentry = connmark_tg_check,
- .target = connmark_tg_v2,
- .targetsize = sizeof(struct xt_connmark_tginfo2),
- .destroy = connmark_tg_destroy,
- .me = THIS_MODULE,
- }
- };
- static struct xt_match connmark_mt_reg __read_mostly = {
- .name = "connmark",
- .revision = 1,
- .family = NFPROTO_UNSPEC,
- .checkentry = connmark_mt_check,
- .match = connmark_mt,
- .matchsize = sizeof(struct xt_connmark_mtinfo1),
- .destroy = connmark_mt_destroy,
- .me = THIS_MODULE,
- };
- static int __init connmark_mt_init(void)
- {
- int ret;
- ret = xt_register_targets(connmark_tg_reg,
- ARRAY_SIZE(connmark_tg_reg));
- if (ret < 0)
- return ret;
- ret = xt_register_match(&connmark_mt_reg);
- if (ret < 0) {
- xt_unregister_targets(connmark_tg_reg,
- ARRAY_SIZE(connmark_tg_reg));
- return ret;
- }
- return 0;
- }
- static void __exit connmark_mt_exit(void)
- {
- xt_unregister_match(&connmark_mt_reg);
- xt_unregister_targets(connmark_tg_reg, ARRAY_SIZE(connmark_tg_reg));
- }
- module_init(connmark_mt_init);
- module_exit(connmark_mt_exit);
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