cregit-Linux how code gets into the kernel

Release 4.8 net/ipv6/netfilter/ip6t_NPT.c

/*
 * Copyright (c) 2011, 2012 Patrick McHardy <kaber@trash.net>
 *
 * 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/ipv6.h>
#include <net/ipv6.h>
#include <linux/netfilter.h>
#include <linux/netfilter_ipv6.h>
#include <linux/netfilter_ipv6/ip6t_NPT.h>
#include <linux/netfilter/x_tables.h>


static int ip6t_npt_checkentry(const struct xt_tgchk_param *par) { struct ip6t_npt_tginfo *npt = par->targinfo; struct in6_addr pfx; __wsum src_sum, dst_sum; if (npt->src_pfx_len > 64 || npt->dst_pfx_len > 64) return -EINVAL; /* Ensure that LSB of prefix is zero */ ipv6_addr_prefix(&pfx, &npt->src_pfx.in6, npt->src_pfx_len); if (!ipv6_addr_equal(&pfx, &npt->src_pfx.in6)) return -EINVAL; ipv6_addr_prefix(&pfx, &npt->dst_pfx.in6, npt->dst_pfx_len); if (!ipv6_addr_equal(&pfx, &npt->dst_pfx.in6)) return -EINVAL; src_sum = csum_partial(&npt->src_pfx.in6, sizeof(npt->src_pfx.in6), 0); dst_sum = csum_partial(&npt->dst_pfx.in6, sizeof(npt->dst_pfx.in6), 0); npt->adjustment = ~csum_fold(csum_sub(src_sum, dst_sum)); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
hideaki yoshifujihideaki yoshifuji10757.22%360.00%
patrick mchardypatrick mchardy7942.25%120.00%
ulrich weberulrich weber10.53%120.00%
Total187100.00%5100.00%


static bool ip6t_npt_map_pfx(const struct ip6t_npt_tginfo *npt, struct in6_addr *addr) { unsigned int pfx_len; unsigned int i, idx; __be32 mask; __sum16 sum; pfx_len = max(npt->src_pfx_len, npt->dst_pfx_len); for (i = 0; i < pfx_len; i += 32) { if (pfx_len - i >= 32) mask = 0; else mask = htonl((1 << (i - pfx_len + 32)) - 1); idx = i / 32; addr->s6_addr32[idx] &= mask; addr->s6_addr32[idx] |= ~mask & npt->dst_pfx.in6.s6_addr32[idx]; } if (pfx_len <= 48) idx = 3; else { for (idx = 4; idx < ARRAY_SIZE(addr->s6_addr16); idx++) { if ((__force __sum16)addr->s6_addr16[idx] != CSUM_MANGLED_0) break; } if (idx == ARRAY_SIZE(addr->s6_addr16)) return false; } sum = ~csum_fold(csum_add(csum_unfold((__force __sum16)addr->s6_addr16[idx]), csum_unfold(npt->adjustment))); if (sum == CSUM_MANGLED_0) sum = 0; *(__force __sum16 *)&addr->s6_addr16[idx] = sum; return true; }

Contributors

PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy22990.87%120.00%
hideaki yoshifujihideaki yoshifuji145.56%240.00%
ulrich weberulrich weber51.98%120.00%
matthias schiffermatthias schiffer41.59%120.00%
Total252100.00%5100.00%


static unsigned int ip6t_snpt_tg(struct sk_buff *skb, const struct xt_action_param *par) { const struct ip6t_npt_tginfo *npt = par->targinfo; if (!ip6t_npt_map_pfx(npt, &ipv6_hdr(skb)->saddr)) { icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_HDR_FIELD, offsetof(struct ipv6hdr, saddr)); return NF_DROP; } return XT_CONTINUE; }

Contributors

PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy69100.00%1100.00%
Total69100.00%1100.00%


static unsigned int ip6t_dnpt_tg(struct sk_buff *skb, const struct xt_action_param *par) { const struct ip6t_npt_tginfo *npt = par->targinfo; if (!ip6t_npt_map_pfx(npt, &ipv6_hdr(skb)->daddr)) { icmpv6_send(skb, ICMPV6_PARAMPROB, ICMPV6_HDR_FIELD, offsetof(struct ipv6hdr, daddr)); return NF_DROP; } return XT_CONTINUE; }

Contributors

PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy69100.00%1100.00%
Total69100.00%1100.00%

static struct xt_target ip6t_npt_target_reg[] __read_mostly = { { .name = "SNPT", .table = "mangle", .target = ip6t_snpt_tg, .targetsize = sizeof(struct ip6t_npt_tginfo), .checkentry = ip6t_npt_checkentry, .family = NFPROTO_IPV6, .hooks = (1 << NF_INET_LOCAL_IN) | (1 << NF_INET_POST_ROUTING), .me = THIS_MODULE, }, { .name = "DNPT", .table = "mangle", .target = ip6t_dnpt_tg, .targetsize = sizeof(struct ip6t_npt_tginfo), .checkentry = ip6t_npt_checkentry, .family = NFPROTO_IPV6, .hooks = (1 << NF_INET_PRE_ROUTING) | (1 << NF_INET_LOCAL_OUT), .me = THIS_MODULE, }, };
static int __init ip6t_npt_init(void) { return xt_register_targets(ip6t_npt_target_reg, ARRAY_SIZE(ip6t_npt_target_reg)); }

Contributors

PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy20100.00%1100.00%
Total20100.00%1100.00%


static void __exit ip6t_npt_exit(void) { xt_unregister_targets(ip6t_npt_target_reg, ARRAY_SIZE(ip6t_npt_target_reg)); }

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patrick mchardypatrick mchardy19100.00%1100.00%
Total19100.00%1100.00%

module_init(ip6t_npt_init); module_exit(ip6t_npt_exit); MODULE_LICENSE("GPL"); MODULE_DESCRIPTION("IPv6-to-IPv6 Network Prefix Translation (RFC 6296)"); MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>"); MODULE_ALIAS("ip6t_SNPT"); MODULE_ALIAS("ip6t_DNPT");

Overall Contributors

PersonTokensPropCommitsCommitProp
patrick mchardypatrick mchardy65381.93%112.50%
hideaki yoshifujihideaki yoshifuji12415.56%450.00%
florian westphalflorian westphal101.25%112.50%
ulrich weberulrich weber60.75%112.50%
matthias schiffermatthias schiffer40.50%112.50%
Total797100.00%8100.00%
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