xt_CONNSECMARK.rar_back

/* * This module is used to copy security markings from packets * to connections, and restore security markings from connections * back to packets. This would normally be performed in conjunction * with the SECMARK target and state match. * * * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/skbuff.h> #include <linux/netfilter/x_tables.h> #include <linux/netfilter/xt_CONNSECMARK.h> #include <net/netfilter/nf_conntrack.h> #include <net/netfilter/nf_conntrack_ecache.h> MODULE_LICENSE("GPL"); MODULE_AUTHOR("James Morris <jmorris@redhat.com>"); MODULE_DESCRIPTION("Xtables: target for copying between connection and security mark"); MODULE_ALIAS("ipt_CONNSECMARK"); MODULE_ALIAS("ip6t_CONNSECMARK"); /* * If the packet has a security mark and the connection does not, copy * the security mark from the packet to the connection. */ static void secmark_save(const struct sk_buff *skb) { if (skb->secmark) { struct nf_conn *ct; enum ip_conntrack_info ctinfo; ct = nf_ct_get(skb, &ctinfo); if (ct && !ct->secmark) { ct->secmark = skb->secmark; nf_conntrack_event_cache(IPCT_SECMARK, ct); } } } /* * If packet has no security mark, and the connection does, restore the * security mark from the connection to the packet. */ static void secmark_restore(struct sk_buff *skb) { if (!skb->secmark) { const struct nf_conn *ct; enum ip_conntrack_info ctinfo; ct = nf_ct_get(skb, &ctinfo); if (ct && ct->secmark) skb->secmark = ct->secmark; } } static unsigned int connsecmark_tg(struct sk_buff *skb, const struct xt_action_param *par) { const struct xt_connsecmark_target_info *info = par->targinfo; switch (info->mode) { case CONNSECMARK_SAVE: secmark_save(skb); break; case CONNSECMARK_RESTORE: secmark_restore(skb); break; default: BUG(); } return XT_CONTINUE; } static int connsecmark_tg_check(const struct xt_tgchk_param *par) { const struct xt_connsecmark_target_info *info = par->targinfo; int ret; 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; } switch (info->mode) { case CONNSECMARK_SAVE: case CONNSECMARK_RESTORE: break; default: pr_info("invalid mode: %hu\n", info->mode); return -EINVAL; } ret = nf_ct_l3proto_try_module_get(par->family); if (ret < 0) pr_info("cannot load conntrack support for proto=%u\n", par->family); return ret; } static void connsecmark_tg_destroy(const struct xt_tgdtor_param *par) { nf_ct_l3proto_module_put(par->family); } static struct xt_target connsecmark_tg_reg __read_mostly = { .name = "CONNSECMARK", .revision = 0, .family = NFPROTO_UNSPEC, .checkentry = connsecmark_tg_check, .destroy = connsecmark_tg_destroy, .target = connsecmark_tg, .targetsize = sizeof(struct xt_connsecmark_target_info), .me = THIS_MODULE, }; static int __init connsecmark_tg_init(void) { return xt_register_target(&connsecmark_tg_reg); } static void __exit connsecmark_tg_exit(void) { xt_unregister_target(&connsecmark_tg_reg); } module_init(connsecmark_tg_init); module_exit(connsecmark_tg_exit);