diff options
Diffstat (limited to 'net/netfilter/xt_conntrack.c')
| -rw-r--r-- | net/netfilter/xt_conntrack.c | 318 |
1 files changed, 123 insertions, 195 deletions
diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c index 0c50b289405..188404b9b00 100644 --- a/net/netfilter/xt_conntrack.c +++ b/net/netfilter/xt_conntrack.c @@ -3,13 +3,14 @@ * information. (Superset of Rusty's minimalistic state match.) * * (C) 2001 Marc Boucher (marc@mbsi.ca). + * (C) 2006-2012 Patrick McHardy <kaber@trash.net> * Copyright © CC Computer Consultants GmbH, 2007 - 2008 * * 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. */ - +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include <linux/module.h> #include <linux/skbuff.h> #include <net/ipv6.h> @@ -19,111 +20,19 @@ MODULE_LICENSE("GPL"); MODULE_AUTHOR("Marc Boucher <marc@mbsi.ca>"); -MODULE_AUTHOR("Jan Engelhardt <jengelh@computergmbh.de>"); +MODULE_AUTHOR("Jan Engelhardt <jengelh@medozas.de>"); MODULE_DESCRIPTION("Xtables: connection tracking state match"); MODULE_ALIAS("ipt_conntrack"); MODULE_ALIAS("ip6t_conntrack"); static bool -conntrack_mt_v0(const struct sk_buff *skb, const struct net_device *in, - const struct net_device *out, const struct xt_match *match, - const void *matchinfo, int offset, unsigned int protoff, - bool *hotdrop) -{ - const struct xt_conntrack_info *sinfo = matchinfo; - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - unsigned int statebit; - - ct = nf_ct_get(skb, &ctinfo); - -#define FWINV(bool, invflg) ((bool) ^ !!(sinfo->invflags & (invflg))) - - if (ct == &nf_conntrack_untracked) - statebit = XT_CONNTRACK_STATE_UNTRACKED; - else if (ct) - statebit = XT_CONNTRACK_STATE_BIT(ctinfo); - else - statebit = XT_CONNTRACK_STATE_INVALID; - - if (sinfo->flags & XT_CONNTRACK_STATE) { - if (ct) { - if (test_bit(IPS_SRC_NAT_BIT, &ct->status)) - statebit |= XT_CONNTRACK_STATE_SNAT; - if (test_bit(IPS_DST_NAT_BIT, &ct->status)) - statebit |= XT_CONNTRACK_STATE_DNAT; - } - if (FWINV((statebit & sinfo->statemask) == 0, - XT_CONNTRACK_STATE)) - return false; - } - - if (ct == NULL) { - if (sinfo->flags & ~XT_CONNTRACK_STATE) - return false; - return true; - } - - if (sinfo->flags & XT_CONNTRACK_PROTO && - FWINV(ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.protonum != - sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.protonum, - XT_CONNTRACK_PROTO)) - return false; - - if (sinfo->flags & XT_CONNTRACK_ORIGSRC && - FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip & - sinfo->sipmsk[IP_CT_DIR_ORIGINAL].s_addr) != - sinfo->tuple[IP_CT_DIR_ORIGINAL].src.ip, - XT_CONNTRACK_ORIGSRC)) - return false; - - if (sinfo->flags & XT_CONNTRACK_ORIGDST && - FWINV((ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3.ip & - sinfo->dipmsk[IP_CT_DIR_ORIGINAL].s_addr) != - sinfo->tuple[IP_CT_DIR_ORIGINAL].dst.ip, - XT_CONNTRACK_ORIGDST)) - return false; - - if (sinfo->flags & XT_CONNTRACK_REPLSRC && - FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip & - sinfo->sipmsk[IP_CT_DIR_REPLY].s_addr) != - sinfo->tuple[IP_CT_DIR_REPLY].src.ip, - XT_CONNTRACK_REPLSRC)) - return false; - - if (sinfo->flags & XT_CONNTRACK_REPLDST && - FWINV((ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip & - sinfo->dipmsk[IP_CT_DIR_REPLY].s_addr) != - sinfo->tuple[IP_CT_DIR_REPLY].dst.ip, - XT_CONNTRACK_REPLDST)) - return false; - - if (sinfo->flags & XT_CONNTRACK_STATUS && - FWINV((ct->status & sinfo->statusmask) == 0, - XT_CONNTRACK_STATUS)) - return false; - - if(sinfo->flags & XT_CONNTRACK_EXPIRES) { - unsigned long expires = timer_pending(&ct->timeout) ? - (ct->timeout.expires - jiffies)/HZ : 0; - - if (FWINV(!(expires >= sinfo->expires_min && - expires <= sinfo->expires_max), - XT_CONNTRACK_EXPIRES)) - return false; - } - return true; -#undef FWINV -} - -static bool conntrack_addrcmp(const union nf_inet_addr *kaddr, const union nf_inet_addr *uaddr, const union nf_inet_addr *umask, unsigned int l3proto) { - if (l3proto == AF_INET) + if (l3proto == NFPROTO_IPV4) return ((kaddr->ip ^ uaddr->ip) & umask->ip) == 0; - else if (l3proto == AF_INET6) + else if (l3proto == NFPROTO_IPV6) return ipv6_masked_addr_cmp(&kaddr->in6, &umask->in6, &uaddr->in6) == 0; else @@ -132,8 +41,8 @@ conntrack_addrcmp(const union nf_inet_addr *kaddr, static inline bool conntrack_mt_origsrc(const struct nf_conn *ct, - const struct xt_conntrack_mtinfo1 *info, - unsigned int family) + const struct xt_conntrack_mtinfo2 *info, + u_int8_t family) { return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3, &info->origsrc_addr, &info->origsrc_mask, family); @@ -141,8 +50,8 @@ conntrack_mt_origsrc(const struct nf_conn *ct, static inline bool conntrack_mt_origdst(const struct nf_conn *ct, - const struct xt_conntrack_mtinfo1 *info, - unsigned int family) + const struct xt_conntrack_mtinfo2 *info, + u_int8_t family) { return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.dst.u3, &info->origdst_addr, &info->origdst_mask, family); @@ -150,8 +59,8 @@ conntrack_mt_origdst(const struct nf_conn *ct, static inline bool conntrack_mt_replsrc(const struct nf_conn *ct, - const struct xt_conntrack_mtinfo1 *info, - unsigned int family) + const struct xt_conntrack_mtinfo2 *info, + u_int8_t family) { return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3, &info->replsrc_addr, &info->replsrc_mask, family); @@ -159,22 +68,22 @@ conntrack_mt_replsrc(const struct nf_conn *ct, static inline bool conntrack_mt_repldst(const struct nf_conn *ct, - const struct xt_conntrack_mtinfo1 *info, - unsigned int family) + const struct xt_conntrack_mtinfo2 *info, + u_int8_t family) { return conntrack_addrcmp(&ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3, &info->repldst_addr, &info->repldst_mask, family); } static inline bool -ct_proto_port_check(const struct xt_conntrack_mtinfo1 *info, +ct_proto_port_check(const struct xt_conntrack_mtinfo2 *info, const struct nf_conn *ct) { const struct nf_conntrack_tuple *tuple; tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; if ((info->match_flags & XT_CONNTRACK_PROTO) && - (tuple->dst.protonum == info->l4proto) ^ + (nf_ct_protonum(ct) == info->l4proto) ^ !(info->invert_flags & XT_CONNTRACK_PROTO)) return false; @@ -204,24 +113,71 @@ ct_proto_port_check(const struct xt_conntrack_mtinfo1 *info, return true; } +static inline bool +port_match(u16 min, u16 max, u16 port, bool invert) +{ + return (port >= min && port <= max) ^ invert; +} + +static inline bool +ct_proto_port_check_v3(const struct xt_conntrack_mtinfo3 *info, + const struct nf_conn *ct) +{ + const struct nf_conntrack_tuple *tuple; + + tuple = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple; + if ((info->match_flags & XT_CONNTRACK_PROTO) && + (nf_ct_protonum(ct) == info->l4proto) ^ + !(info->invert_flags & XT_CONNTRACK_PROTO)) + return false; + + /* Shortcut to match all recognized protocols by using ->src.all. */ + if ((info->match_flags & XT_CONNTRACK_ORIGSRC_PORT) && + !port_match(info->origsrc_port, info->origsrc_port_high, + ntohs(tuple->src.u.all), + info->invert_flags & XT_CONNTRACK_ORIGSRC_PORT)) + return false; + + if ((info->match_flags & XT_CONNTRACK_ORIGDST_PORT) && + !port_match(info->origdst_port, info->origdst_port_high, + ntohs(tuple->dst.u.all), + info->invert_flags & XT_CONNTRACK_ORIGDST_PORT)) + return false; + + tuple = &ct->tuplehash[IP_CT_DIR_REPLY].tuple; + + if ((info->match_flags & XT_CONNTRACK_REPLSRC_PORT) && + !port_match(info->replsrc_port, info->replsrc_port_high, + ntohs(tuple->src.u.all), + info->invert_flags & XT_CONNTRACK_REPLSRC_PORT)) + return false; + + if ((info->match_flags & XT_CONNTRACK_REPLDST_PORT) && + !port_match(info->repldst_port, info->repldst_port_high, + ntohs(tuple->dst.u.all), + info->invert_flags & XT_CONNTRACK_REPLDST_PORT)) + return false; + + return true; +} + static bool -conntrack_mt(const struct sk_buff *skb, const struct net_device *in, - const struct net_device *out, const struct xt_match *match, - const void *matchinfo, int offset, unsigned int protoff, - bool *hotdrop) +conntrack_mt(const struct sk_buff *skb, struct xt_action_param *par, + u16 state_mask, u16 status_mask) { - const struct xt_conntrack_mtinfo1 *info = matchinfo; + const struct xt_conntrack_mtinfo2 *info = par->matchinfo; enum ip_conntrack_info ctinfo; const struct nf_conn *ct; unsigned int statebit; ct = nf_ct_get(skb, &ctinfo); - if (ct == &nf_conntrack_untracked) - statebit = XT_CONNTRACK_STATE_UNTRACKED; - else if (ct != NULL) - statebit = XT_CONNTRACK_STATE_BIT(ctinfo); - else + if (ct) { + if (nf_ct_is_untracked(ct)) + statebit = XT_CONNTRACK_STATE_UNTRACKED; + else + statebit = XT_CONNTRACK_STATE_BIT(ctinfo); + } else statebit = XT_CONNTRACK_STATE_INVALID; if (info->match_flags & XT_CONNTRACK_STATE) { @@ -231,7 +187,7 @@ conntrack_mt(const struct sk_buff *skb, const struct net_device *in, if (test_bit(IPS_DST_NAT_BIT, &ct->status)) statebit |= XT_CONNTRACK_STATE_DNAT; } - if (!!(info->state_mask & statebit) ^ + if (!!(state_mask & statebit) ^ !(info->invert_flags & XT_CONNTRACK_STATE)) return false; } @@ -240,34 +196,39 @@ conntrack_mt(const struct sk_buff *skb, const struct net_device *in, return info->match_flags & XT_CONNTRACK_STATE; if ((info->match_flags & XT_CONNTRACK_DIRECTION) && (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^ - !!(info->invert_flags & XT_CONNTRACK_DIRECTION)) + !(info->invert_flags & XT_CONNTRACK_DIRECTION)) return false; if (info->match_flags & XT_CONNTRACK_ORIGSRC) - if (conntrack_mt_origsrc(ct, info, match->family) ^ + if (conntrack_mt_origsrc(ct, info, par->family) ^ !(info->invert_flags & XT_CONNTRACK_ORIGSRC)) return false; if (info->match_flags & XT_CONNTRACK_ORIGDST) - if (conntrack_mt_origdst(ct, info, match->family) ^ + if (conntrack_mt_origdst(ct, info, par->family) ^ !(info->invert_flags & XT_CONNTRACK_ORIGDST)) return false; if (info->match_flags & XT_CONNTRACK_REPLSRC) - if (conntrack_mt_replsrc(ct, info, match->family) ^ + if (conntrack_mt_replsrc(ct, info, par->family) ^ !(info->invert_flags & XT_CONNTRACK_REPLSRC)) return false; if (info->match_flags & XT_CONNTRACK_REPLDST) - if (conntrack_mt_repldst(ct, info, match->family) ^ + if (conntrack_mt_repldst(ct, info, par->family) ^ !(info->invert_flags & XT_CONNTRACK_REPLDST)) return false; - if (!ct_proto_port_check(info, ct)) - return false; + if (par->match->revision != 3) { + if (!ct_proto_port_check(info, ct)) + return false; + } else { + if (!ct_proto_port_check_v3(par->matchinfo, ct)) + return false; + } if ((info->match_flags & XT_CONNTRACK_STATUS) && - (!!(info->status_mask & ct->status) ^ + (!!(status_mask & ct->status) ^ !(info->invert_flags & XT_CONNTRACK_STATUS))) return false; @@ -285,105 +246,72 @@ conntrack_mt(const struct sk_buff *skb, const struct net_device *in, } static bool -conntrack_mt_check(const char *tablename, const void *ip, - const struct xt_match *match, void *matchinfo, - unsigned int hook_mask) +conntrack_mt_v1(const struct sk_buff *skb, struct xt_action_param *par) { - if (nf_ct_l3proto_try_module_get(match->family) < 0) { - printk(KERN_WARNING "can't load conntrack support for " - "proto=%u\n", match->family); - return false; - } - return true; + const struct xt_conntrack_mtinfo1 *info = par->matchinfo; + + return conntrack_mt(skb, par, info->state_mask, info->status_mask); } -static void -conntrack_mt_destroy(const struct xt_match *match, void *matchinfo) +static bool +conntrack_mt_v2(const struct sk_buff *skb, struct xt_action_param *par) { - nf_ct_l3proto_module_put(match->family); + const struct xt_conntrack_mtinfo2 *info = par->matchinfo; + + return conntrack_mt(skb, par, info->state_mask, info->status_mask); } -#ifdef CONFIG_COMPAT -struct compat_xt_conntrack_info +static bool +conntrack_mt_v3(const struct sk_buff *skb, struct xt_action_param *par) { - compat_uint_t statemask; - compat_uint_t statusmask; - struct ip_conntrack_old_tuple tuple[IP_CT_DIR_MAX]; - struct in_addr sipmsk[IP_CT_DIR_MAX]; - struct in_addr dipmsk[IP_CT_DIR_MAX]; - compat_ulong_t expires_min; - compat_ulong_t expires_max; - u_int8_t flags; - u_int8_t invflags; -}; + const struct xt_conntrack_mtinfo3 *info = par->matchinfo; + + return conntrack_mt(skb, par, info->state_mask, info->status_mask); +} -static void conntrack_mt_compat_from_user_v0(void *dst, void *src) +static int conntrack_mt_check(const struct xt_mtchk_param *par) { - const struct compat_xt_conntrack_info *cm = src; - struct xt_conntrack_info m = { - .statemask = cm->statemask, - .statusmask = cm->statusmask, - .expires_min = cm->expires_min, - .expires_max = cm->expires_max, - .flags = cm->flags, - .invflags = cm->invflags, - }; - memcpy(m.tuple, cm->tuple, sizeof(m.tuple)); - memcpy(m.sipmsk, cm->sipmsk, sizeof(m.sipmsk)); - memcpy(m.dipmsk, cm->dipmsk, sizeof(m.dipmsk)); - memcpy(dst, &m, sizeof(m)); + int ret; + + 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 int conntrack_mt_compat_to_user_v0(void __user *dst, void *src) +static void conntrack_mt_destroy(const struct xt_mtdtor_param *par) { - const struct xt_conntrack_info *m = src; - struct compat_xt_conntrack_info cm = { - .statemask = m->statemask, - .statusmask = m->statusmask, - .expires_min = m->expires_min, - .expires_max = m->expires_max, - .flags = m->flags, - .invflags = m->invflags, - }; - memcpy(cm.tuple, m->tuple, sizeof(cm.tuple)); - memcpy(cm.sipmsk, m->sipmsk, sizeof(cm.sipmsk)); - memcpy(cm.dipmsk, m->dipmsk, sizeof(cm.dipmsk)); - return copy_to_user(dst, &cm, sizeof(cm)) ? -EFAULT : 0; + nf_ct_l3proto_module_put(par->family); } -#endif static struct xt_match conntrack_mt_reg[] __read_mostly = { { .name = "conntrack", - .revision = 0, - .family = AF_INET, - .match = conntrack_mt_v0, + .revision = 1, + .family = NFPROTO_UNSPEC, + .matchsize = sizeof(struct xt_conntrack_mtinfo1), + .match = conntrack_mt_v1, .checkentry = conntrack_mt_check, .destroy = conntrack_mt_destroy, - .matchsize = sizeof(struct xt_conntrack_info), .me = THIS_MODULE, -#ifdef CONFIG_COMPAT - .compatsize = sizeof(struct compat_xt_conntrack_info), - .compat_from_user = conntrack_mt_compat_from_user_v0, - .compat_to_user = conntrack_mt_compat_to_user_v0, -#endif }, { .name = "conntrack", - .revision = 1, - .family = AF_INET, - .matchsize = sizeof(struct xt_conntrack_mtinfo1), - .match = conntrack_mt, + .revision = 2, + .family = NFPROTO_UNSPEC, + .matchsize = sizeof(struct xt_conntrack_mtinfo2), + .match = conntrack_mt_v2, .checkentry = conntrack_mt_check, .destroy = conntrack_mt_destroy, .me = THIS_MODULE, }, { .name = "conntrack", - .revision = 1, - .family = AF_INET6, - .matchsize = sizeof(struct xt_conntrack_mtinfo1), - .match = conntrack_mt, + .revision = 3, + .family = NFPROTO_UNSPEC, + .matchsize = sizeof(struct xt_conntrack_mtinfo3), + .match = conntrack_mt_v3, .checkentry = conntrack_mt_check, .destroy = conntrack_mt_destroy, .me = THIS_MODULE, |
