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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 | // 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; u_int32_t oldmark; ct = nf_ct_get(skb, &ctinfo); if (ct == NULL) return XT_CONTINUE; switch (info->mode) { case XT_CONNMARK_SET: oldmark = READ_ONCE(ct->mark); newmark = (oldmark & ~info->ctmask) ^ info->ctmark; if (info->shift_dir == D_SHIFT_RIGHT) newmark >>= info->shift_bits; else newmark <<= info->shift_bits; if (READ_ONCE(ct->mark) != newmark) { WRITE_ONCE(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 = (READ_ONCE(ct->mark) & ~info->ctmask) ^ new_targetmark; if (READ_ONCE(ct->mark) != newmark) { WRITE_ONCE(ct->mark, newmark); nf_conntrack_event_cache(IPCT_MARK, ct); } break; case XT_CONNMARK_RESTORE: new_targetmark = (READ_ONCE(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 ((READ_ONCE(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); |