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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /net/ipv6/netfilter/ip6table_mangle.c | |
parent | Initial commit. (diff) | |
download | linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'net/ipv6/netfilter/ip6table_mangle.c')
-rw-r--r-- | net/ipv6/netfilter/ip6table_mangle.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/net/ipv6/netfilter/ip6table_mangle.c b/net/ipv6/netfilter/ip6table_mangle.c new file mode 100644 index 000000000..cee74803d --- /dev/null +++ b/net/ipv6/netfilter/ip6table_mangle.c @@ -0,0 +1,146 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IPv6 packet mangling table, a port of the IPv4 mangle table to IPv6 + * + * Copyright (C) 2000-2001 by Harald Welte <laforge@gnumonks.org> + * Copyright (C) 2000-2004 Netfilter Core Team <coreteam@netfilter.org> + */ +#include <linux/module.h> +#include <linux/netfilter_ipv6/ip6_tables.h> +#include <linux/slab.h> +#include <net/ipv6.h> + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); +MODULE_DESCRIPTION("ip6tables mangle table"); + +#define MANGLE_VALID_HOOKS ((1 << NF_INET_PRE_ROUTING) | \ + (1 << NF_INET_LOCAL_IN) | \ + (1 << NF_INET_FORWARD) | \ + (1 << NF_INET_LOCAL_OUT) | \ + (1 << NF_INET_POST_ROUTING)) + +static int __net_init ip6table_mangle_table_init(struct net *net); + +static const struct xt_table packet_mangler = { + .name = "mangle", + .valid_hooks = MANGLE_VALID_HOOKS, + .me = THIS_MODULE, + .af = NFPROTO_IPV6, + .priority = NF_IP6_PRI_MANGLE, + .table_init = ip6table_mangle_table_init, +}; + +static unsigned int +ip6t_mangle_out(struct sk_buff *skb, const struct nf_hook_state *state) +{ + unsigned int ret; + struct in6_addr saddr, daddr; + u_int8_t hop_limit; + u_int32_t flowlabel, mark; + int err; + + /* save source/dest address, mark, hoplimit, flowlabel, priority, */ + memcpy(&saddr, &ipv6_hdr(skb)->saddr, sizeof(saddr)); + memcpy(&daddr, &ipv6_hdr(skb)->daddr, sizeof(daddr)); + mark = skb->mark; + hop_limit = ipv6_hdr(skb)->hop_limit; + + /* flowlabel and prio (includes version, which shouldn't change either */ + flowlabel = *((u_int32_t *)ipv6_hdr(skb)); + + ret = ip6t_do_table(skb, state, state->net->ipv6.ip6table_mangle); + + if (ret != NF_DROP && ret != NF_STOLEN && + (!ipv6_addr_equal(&ipv6_hdr(skb)->saddr, &saddr) || + !ipv6_addr_equal(&ipv6_hdr(skb)->daddr, &daddr) || + skb->mark != mark || + ipv6_hdr(skb)->hop_limit != hop_limit || + flowlabel != *((u_int32_t *)ipv6_hdr(skb)))) { + err = ip6_route_me_harder(state->net, state->sk, skb); + if (err < 0) + ret = NF_DROP_ERR(err); + } + + return ret; +} + +/* The work comes in here from netfilter.c. */ +static unsigned int +ip6table_mangle_hook(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + if (state->hook == NF_INET_LOCAL_OUT) + return ip6t_mangle_out(skb, state); + return ip6t_do_table(skb, state, state->net->ipv6.ip6table_mangle); +} + +static struct nf_hook_ops *mangle_ops __read_mostly; +static int __net_init ip6table_mangle_table_init(struct net *net) +{ + struct ip6t_replace *repl; + int ret; + + if (net->ipv6.ip6table_mangle) + return 0; + + repl = ip6t_alloc_initial_table(&packet_mangler); + if (repl == NULL) + return -ENOMEM; + ret = ip6t_register_table(net, &packet_mangler, repl, mangle_ops, + &net->ipv6.ip6table_mangle); + kfree(repl); + return ret; +} + +static void __net_exit ip6table_mangle_net_pre_exit(struct net *net) +{ + if (net->ipv6.ip6table_mangle) + ip6t_unregister_table_pre_exit(net, net->ipv6.ip6table_mangle, + mangle_ops); +} + +static void __net_exit ip6table_mangle_net_exit(struct net *net) +{ + if (!net->ipv6.ip6table_mangle) + return; + + ip6t_unregister_table_exit(net, net->ipv6.ip6table_mangle); + net->ipv6.ip6table_mangle = NULL; +} + +static struct pernet_operations ip6table_mangle_net_ops = { + .pre_exit = ip6table_mangle_net_pre_exit, + .exit = ip6table_mangle_net_exit, +}; + +static int __init ip6table_mangle_init(void) +{ + int ret; + + mangle_ops = xt_hook_ops_alloc(&packet_mangler, ip6table_mangle_hook); + if (IS_ERR(mangle_ops)) + return PTR_ERR(mangle_ops); + + ret = register_pernet_subsys(&ip6table_mangle_net_ops); + if (ret < 0) { + kfree(mangle_ops); + return ret; + } + + ret = ip6table_mangle_table_init(&init_net); + if (ret) { + unregister_pernet_subsys(&ip6table_mangle_net_ops); + kfree(mangle_ops); + } + return ret; +} + +static void __exit ip6table_mangle_fini(void) +{ + unregister_pernet_subsys(&ip6table_mangle_net_ops); + kfree(mangle_ops); +} + +module_init(ip6table_mangle_init); +module_exit(ip6table_mangle_fini); |