diff options
author | David S. Miller <davem@davemloft.net> | 2014-09-10 12:46:32 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-09-10 12:46:32 -0700 |
commit | 0aac383353693edcd8fc5a82a692bb7e5f60d2fd (patch) | |
tree | 53750f41a82c12fb468d360b635bcbd65958ccc9 /net/ipv4 | |
parent | b167a37c7bbc6f7589f439ba7d9a49af5ad37ff5 (diff) | |
parent | 9ba1f726bec090399eb9bb9157eb32dedc8e8c45 (diff) |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next
Pablo Neira Ayuso says:
====================
nf-next pull request
The following patchset contains Netfilter/IPVS updates for your
net-next tree. Regarding nf_tables, most updates focus on consolidating
the NAT infrastructure and adding support for masquerading. More
specifically, they are:
1) use __u8 instead of u_int8_t in arptables header, from
Mike Frysinger.
2) Add support to match by skb->pkttype to the meta expression, from
Ana Rey.
3) Add support to match by cpu to the meta expression, also from
Ana Rey.
4) A smatch warning about IPSET_ATTR_MARKMASK validation, patch from
Vytas Dauksa.
5) Fix netnet and netportnet hash types the range support for IPv4,
from Sergey Popovich.
6) Fix missing-field-initializer warnings resolved, from Mark Rustad.
7) Dan Carperter reported possible integer overflows in ipset, from
Jozsef Kadlecsick.
8) Filter out accounting objects in nfacct by type, so you can
selectively reset quotas, from Alexey Perevalov.
9) Move specific NAT IPv4 functions to the core so x_tables and
nf_tables can share the same NAT IPv4 engine.
10) Use the new NAT IPv4 functions from nft_chain_nat_ipv4.
11) Move specific NAT IPv6 functions to the core so x_tables and
nf_tables can share the same NAT IPv4 engine.
12) Use the new NAT IPv6 functions from nft_chain_nat_ipv6.
13) Refactor code to add nft_delrule(), which can be reused in the
enhancement of the NFT_MSG_DELTABLE to remove a table and its
content, from Arturo Borrero.
14) Add a helper function to unregister chain hooks, from
Arturo Borrero.
15) A cleanup to rename to nft_delrule_by_chain for consistency with
the new nft_*() functions, also from Arturo.
16) Add support to match devgroup to the meta expression, from Ana Rey.
17) Reduce stack usage for IPVS socket option, from Julian Anastasov.
18) Remove unnecessary textsearch state initialization in xt_string,
from Bojan Prtvar.
19) Add several helper functions to nf_tables, more work to prepare
the enhancement of NFT_MSG_DELTABLE, again from Arturo Borrero.
20) Enhance NFT_MSG_DELTABLE to delete a table and its content, from
Arturo Borrero.
21) Support NAT flags in the nat expression to indicate the flavour,
eg. random fully, from Arturo.
22) Add missing audit code to ebtables when replacing tables, from
Nicolas Dichtel.
23) Generalize the IPv4 masquerading code to allow its re-use from
nf_tables, from Arturo.
24) Generalize the IPv6 masquerading code, also from Arturo.
25) Add the new masq expression to support IPv4/IPv6 masquerading
from nf_tables, also from Arturo.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
-rw-r--r-- | net/ipv4/netfilter/Kconfig | 13 | ||||
-rw-r--r-- | net/ipv4/netfilter/Makefile | 2 | ||||
-rw-r--r-- | net/ipv4/netfilter/ipt_MASQUERADE.c | 108 | ||||
-rw-r--r-- | net/ipv4/netfilter/iptable_nat.c | 233 | ||||
-rw-r--r-- | net/ipv4/netfilter/nf_nat_l3proto_ipv4.c | 199 | ||||
-rw-r--r-- | net/ipv4/netfilter/nf_nat_masquerade_ipv4.c | 153 | ||||
-rw-r--r-- | net/ipv4/netfilter/nft_chain_nat_ipv4.c | 157 | ||||
-rw-r--r-- | net/ipv4/netfilter/nft_masq_ipv4.c | 89 |
8 files changed, 536 insertions, 418 deletions
diff --git a/net/ipv4/netfilter/Kconfig b/net/ipv4/netfilter/Kconfig index 7cbcaf4f0194..d189c5262bdb 100644 --- a/net/ipv4/netfilter/Kconfig +++ b/net/ipv4/netfilter/Kconfig @@ -232,8 +232,21 @@ config IP_NF_NAT if IP_NF_NAT +config NF_NAT_MASQUERADE_IPV4 + tristate "IPv4 masquerade support" + help + This is the kernel functionality to provide NAT in the masquerade + flavour (automatic source address selection). + +config NFT_MASQ_IPV4 + tristate "IPv4 masquerading support for nf_tables" + depends on NF_TABLES_IPV4 + depends on NFT_MASQ + select NF_NAT_MASQUERADE_IPV4 + config IP_NF_TARGET_MASQUERADE tristate "MASQUERADE target support" + select NF_NAT_MASQUERADE_IPV4 default m if NETFILTER_ADVANCED=n help Masquerading is a special case of NAT: all outgoing connections are diff --git a/net/ipv4/netfilter/Makefile b/net/ipv4/netfilter/Makefile index edf4af32e9f2..14488cc5fd2c 100644 --- a/net/ipv4/netfilter/Makefile +++ b/net/ipv4/netfilter/Makefile @@ -27,6 +27,7 @@ obj-$(CONFIG_NF_LOG_IPV4) += nf_log_ipv4.o obj-$(CONFIG_NF_NAT_H323) += nf_nat_h323.o obj-$(CONFIG_NF_NAT_PPTP) += nf_nat_pptp.o obj-$(CONFIG_NF_NAT_SNMP_BASIC) += nf_nat_snmp_basic.o +obj-$(CONFIG_NF_NAT_MASQUERADE_IPV4) += nf_nat_masquerade_ipv4.o # NAT protocols (nf_nat) obj-$(CONFIG_NF_NAT_PROTO_GRE) += nf_nat_proto_gre.o @@ -35,6 +36,7 @@ obj-$(CONFIG_NF_TABLES_IPV4) += nf_tables_ipv4.o obj-$(CONFIG_NFT_CHAIN_ROUTE_IPV4) += nft_chain_route_ipv4.o obj-$(CONFIG_NFT_CHAIN_NAT_IPV4) += nft_chain_nat_ipv4.o obj-$(CONFIG_NFT_REJECT_IPV4) += nft_reject_ipv4.o +obj-$(CONFIG_NFT_MASQ_IPV4) += nft_masq_ipv4.o obj-$(CONFIG_NF_TABLES_ARP) += nf_tables_arp.o # generic IP tables diff --git a/net/ipv4/netfilter/ipt_MASQUERADE.c b/net/ipv4/netfilter/ipt_MASQUERADE.c index 00352ce0f0de..da7f02a0b868 100644 --- a/net/ipv4/netfilter/ipt_MASQUERADE.c +++ b/net/ipv4/netfilter/ipt_MASQUERADE.c @@ -22,6 +22,7 @@ #include <linux/netfilter_ipv4.h> #include <linux/netfilter/x_tables.h> #include <net/netfilter/nf_nat.h> +#include <net/netfilter/ipv4/nf_nat_masquerade.h> MODULE_LICENSE("GPL"); MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); @@ -46,103 +47,17 @@ static int masquerade_tg_check(const struct xt_tgchk_param *par) static unsigned int masquerade_tg(struct sk_buff *skb, const struct xt_action_param *par) { - struct nf_conn *ct; - struct nf_conn_nat *nat; - enum ip_conntrack_info ctinfo; - struct nf_nat_range newrange; + struct nf_nat_range range; const struct nf_nat_ipv4_multi_range_compat *mr; - const struct rtable *rt; - __be32 newsrc, nh; - - NF_CT_ASSERT(par->hooknum == NF_INET_POST_ROUTING); - - ct = nf_ct_get(skb, &ctinfo); - nat = nfct_nat(ct); - - NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || - ctinfo == IP_CT_RELATED_REPLY)); - - /* Source address is 0.0.0.0 - locally generated packet that is - * probably not supposed to be masqueraded. - */ - if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip == 0) - return NF_ACCEPT; mr = par->targinfo; - rt = skb_rtable(skb); - nh = rt_nexthop(rt, ip_hdr(skb)->daddr); - newsrc = inet_select_addr(par->out, nh, RT_SCOPE_UNIVERSE); - if (!newsrc) { - pr_info("%s ate my IP address\n", par->out->name); - return NF_DROP; - } - - nat->masq_index = par->out->ifindex; - - /* Transfer from original range. */ - memset(&newrange.min_addr, 0, sizeof(newrange.min_addr)); - memset(&newrange.max_addr, 0, sizeof(newrange.max_addr)); - newrange.flags = mr->range[0].flags | NF_NAT_RANGE_MAP_IPS; - newrange.min_addr.ip = newsrc; - newrange.max_addr.ip = newsrc; - newrange.min_proto = mr->range[0].min; - newrange.max_proto = mr->range[0].max; + range.flags = mr->range[0].flags; + range.min_proto = mr->range[0].min; + range.max_proto = mr->range[0].max; - /* Hand modified range to generic setup. */ - return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC); + return nf_nat_masquerade_ipv4(skb, par->hooknum, &range, par->out); } -static int -device_cmp(struct nf_conn *i, void *ifindex) -{ - const struct nf_conn_nat *nat = nfct_nat(i); - - if (!nat) - return 0; - if (nf_ct_l3num(i) != NFPROTO_IPV4) - return 0; - return nat->masq_index == (int)(long)ifindex; -} - -static int masq_device_event(struct notifier_block *this, - unsigned long event, - void *ptr) -{ - const struct net_device *dev = netdev_notifier_info_to_dev(ptr); - struct net *net = dev_net(dev); - - if (event == NETDEV_DOWN) { - /* Device was downed. Search entire table for - conntracks which were associated with that device, - and forget them. */ - NF_CT_ASSERT(dev->ifindex != 0); - - nf_ct_iterate_cleanup(net, device_cmp, - (void *)(long)dev->ifindex, 0, 0); - } - - return NOTIFY_DONE; -} - -static int masq_inet_event(struct notifier_block *this, - unsigned long event, - void *ptr) -{ - struct net_device *dev = ((struct in_ifaddr *)ptr)->ifa_dev->dev; - struct netdev_notifier_info info; - - netdev_notifier_info_init(&info, dev); - return masq_device_event(this, event, &info); -} - -static struct notifier_block masq_dev_notifier = { - .notifier_call = masq_device_event, -}; - -static struct notifier_block masq_inet_notifier = { - .notifier_call = masq_inet_event, -}; - static struct xt_target masquerade_tg_reg __read_mostly = { .name = "MASQUERADE", .family = NFPROTO_IPV4, @@ -160,12 +75,8 @@ static int __init masquerade_tg_init(void) ret = xt_register_target(&masquerade_tg_reg); - if (ret == 0) { - /* Register for device down reports */ - register_netdevice_notifier(&masq_dev_notifier); - /* Register IP address change reports */ - register_inetaddr_notifier(&masq_inet_notifier); - } + if (ret == 0) + nf_nat_masquerade_ipv4_register_notifier(); return ret; } @@ -173,8 +84,7 @@ static int __init masquerade_tg_init(void) static void __exit masquerade_tg_exit(void) { xt_unregister_target(&masquerade_tg_reg); - unregister_netdevice_notifier(&masq_dev_notifier); - unregister_inetaddr_notifier(&masq_inet_notifier); + nf_nat_masquerade_ipv4_unregister_notifier(); } module_init(masquerade_tg_init); diff --git a/net/ipv4/netfilter/iptable_nat.c b/net/ipv4/netfilter/iptable_nat.c index f1787c04a4dd..6b67d7e9a75d 100644 --- a/net/ipv4/netfilter/iptable_nat.c +++ b/net/ipv4/netfilter/iptable_nat.c @@ -28,222 +28,57 @@ static const struct xt_table nf_nat_ipv4_table = { .af = NFPROTO_IPV4, }; -static unsigned int alloc_null_binding(struct nf_conn *ct, unsigned int hooknum) -{ - /* Force range to this IP; let proto decide mapping for - * per-proto parts (hence not IP_NAT_RANGE_PROTO_SPECIFIED). - */ - struct nf_nat_range range; - - range.flags = 0; - pr_debug("Allocating NULL binding for %p (%pI4)\n", ct, - HOOK2MANIP(hooknum) == NF_NAT_MANIP_SRC ? - &ct->tuplehash[IP_CT_DIR_REPLY].tuple.dst.u3.ip : - &ct->tuplehash[IP_CT_DIR_REPLY].tuple.src.u3.ip); - - return nf_nat_setup_info(ct, &range, HOOK2MANIP(hooknum)); -} - -static unsigned int nf_nat_rule_find(struct sk_buff *skb, unsigned int hooknum, - const struct net_device *in, - const struct net_device *out, - struct nf_conn *ct) +static unsigned int iptable_nat_do_chain(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct) { struct net *net = nf_ct_net(ct); - unsigned int ret; - ret = ipt_do_table(skb, hooknum, in, out, net->ipv4.nat_table); - if (ret == NF_ACCEPT) { - if (!nf_nat_initialized(ct, HOOK2MANIP(hooknum))) - ret = alloc_null_binding(ct, hooknum); - } - return ret; + return ipt_do_table(skb, ops->hooknum, in, out, net->ipv4.nat_table); } -static unsigned int -nf_nat_ipv4_fn(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int iptable_nat_ipv4_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - struct nf_conn_nat *nat; - /* maniptype == SRC for postrouting. */ - enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum); - - /* We never see fragments: conntrack defrags on pre-routing - * and local-out, and nf_nat_out protects post-routing. - */ - NF_CT_ASSERT(!ip_is_fragment(ip_hdr(skb))); - - ct = nf_ct_get(skb, &ctinfo); - /* Can't track? It's not due to stress, or conntrack would - * have dropped it. Hence it's the user's responsibilty to - * packet filter it out, or implement conntrack/NAT for that - * protocol. 8) --RR - */ - if (!ct) - return NF_ACCEPT; - - /* Don't try to NAT if this packet is not conntracked */ - if (nf_ct_is_untracked(ct)) - return NF_ACCEPT; - - nat = nf_ct_nat_ext_add(ct); - if (nat == NULL) - return NF_ACCEPT; - - switch (ctinfo) { - case IP_CT_RELATED: - case IP_CT_RELATED_REPLY: - if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { - if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, - ops->hooknum)) - return NF_DROP; - else - return NF_ACCEPT; - } - /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */ - case IP_CT_NEW: - /* Seen it before? This can happen for loopback, retrans, - * or local packets. - */ - if (!nf_nat_initialized(ct, maniptype)) { - unsigned int ret; - - ret = nf_nat_rule_find(skb, ops->hooknum, in, out, ct); - if (ret != NF_ACCEPT) - return ret; - } else { - pr_debug("Already setup manip %s for ct %p\n", - maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST", - ct); - if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) - goto oif_changed; - } - break; - - default: - /* ESTABLISHED */ - NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || - ctinfo == IP_CT_ESTABLISHED_REPLY); - if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) - goto oif_changed; - } - - return nf_nat_packet(ct, ctinfo, ops->hooknum, skb); - -oif_changed: - nf_ct_kill_acct(ct, ctinfo, skb); - return NF_DROP; + return nf_nat_ipv4_fn(ops, skb, in, out, iptable_nat_do_chain); } -static unsigned int -nf_nat_ipv4_in(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int iptable_nat_ipv4_in(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - unsigned int ret; - __be32 daddr = ip_hdr(skb)->daddr; - - ret = nf_nat_ipv4_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - daddr != ip_hdr(skb)->daddr) - skb_dst_drop(skb); - - return ret; + return nf_nat_ipv4_in(ops, skb, in, out, iptable_nat_do_chain); } -static unsigned int -nf_nat_ipv4_out(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int iptable_nat_ipv4_out(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { -#ifdef CONFIG_XFRM - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - int err; -#endif - unsigned int ret; - - /* root is playing with raw sockets. */ - if (skb->len < sizeof(struct iphdr) || - ip_hdrlen(skb) < sizeof(struct iphdr)) - return NF_ACCEPT; - - ret = nf_nat_ipv4_fn(ops, skb, in, out, okfn); -#ifdef CONFIG_XFRM - if (ret != NF_DROP && ret != NF_STOLEN && - !(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if ((ct->tuplehash[dir].tuple.src.u3.ip != - ct->tuplehash[!dir].tuple.dst.u3.ip) || - (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && - ct->tuplehash[dir].tuple.src.u.all != - ct->tuplehash[!dir].tuple.dst.u.all)) { - err = nf_xfrm_me_harder(skb, AF_INET); - if (err < 0) - ret = NF_DROP_ERR(err); - } - } -#endif - return ret; + return nf_nat_ipv4_out(ops, skb, in, out, iptable_nat_do_chain); } -static unsigned int -nf_nat_ipv4_local_fn(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int iptable_nat_ipv4_local_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - const struct nf_conn *ct; - enum ip_conntrack_info ctinfo; - unsigned int ret; - int err; - - /* root is playing with raw sockets. */ - if (skb->len < sizeof(struct iphdr) || - ip_hdrlen(skb) < sizeof(struct iphdr)) - return NF_ACCEPT; - - ret = nf_nat_ipv4_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (ct->tuplehash[dir].tuple.dst.u3.ip != - ct->tuplehash[!dir].tuple.src.u3.ip) { - err = ip_route_me_harder(skb, RTN_UNSPEC); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#ifdef CONFIG_XFRM - else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && - ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && - ct->tuplehash[dir].tuple.dst.u.all != - ct->tuplehash[!dir].tuple.src.u.all) { - err = nf_xfrm_me_harder(skb, AF_INET); - if (err < 0) - ret = NF_DROP_ERR(err); - } -#endif - } - return ret; + return nf_nat_ipv4_local_fn(ops, skb, in, out, iptable_nat_do_chain); } static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = { /* Before packet filtering, change destination */ { - .hook = nf_nat_ipv4_in, + .hook = iptable_nat_ipv4_in, .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_PRE_ROUTING, @@ -251,7 +86,7 @@ static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = { }, /* After packet filtering, change source */ { - .hook = nf_nat_ipv4_out, + .hook = iptable_nat_ipv4_out, .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_POST_ROUTING, @@ -259,7 +94,7 @@ static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = { }, /* Before packet filtering, change destination */ { - .hook = nf_nat_ipv4_local_fn, + .hook = iptable_nat_ipv4_local_fn, .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_LOCAL_OUT, @@ -267,7 +102,7 @@ static struct nf_hook_ops nf_nat_ipv4_ops[] __read_mostly = { }, /* After packet filtering, change source */ { - .hook = nf_nat_ipv4_fn, + .hook = iptable_nat_ipv4_fn, .owner = THIS_MODULE, .pf = NFPROTO_IPV4, .hooknum = NF_INET_LOCAL_IN, diff --git a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c index 14f5ccd06337..fc37711e11f3 100644 --- a/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c +++ b/net/ipv4/netfilter/nf_nat_l3proto_ipv4.c @@ -254,6 +254,205 @@ int nf_nat_icmp_reply_translation(struct sk_buff *skb, } EXPORT_SYMBOL_GPL(nf_nat_icmp_reply_translation); +unsigned int +nf_nat_ipv4_fn(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ + struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + struct nf_conn_nat *nat; + /* maniptype == SRC for postrouting. */ + enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum); + + /* We never see fragments: conntrack defrags on pre-routing + * and local-out, and nf_nat_out protects post-routing. + */ + NF_CT_ASSERT(!ip_is_fragment(ip_hdr(skb))); + + ct = nf_ct_get(skb, &ctinfo); + /* Can't track? It's not due to stress, or conntrack would + * have dropped it. Hence it's the user's responsibilty to + * packet filter it out, or implement conntrack/NAT for that + * protocol. 8) --RR + */ + if (!ct) + return NF_ACCEPT; + + /* Don't try to NAT if this packet is not conntracked */ + if (nf_ct_is_untracked(ct)) + return NF_ACCEPT; + + nat = nf_ct_nat_ext_add(ct); + if (nat == NULL) + return NF_ACCEPT; + + switch (ctinfo) { + case IP_CT_RELATED: + case IP_CT_RELATED_REPLY: + if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { + if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, + ops->hooknum)) + return NF_DROP; + else + return NF_ACCEPT; + } + /* Fall thru... (Only ICMPs can be IP_CT_IS_REPLY) */ + case IP_CT_NEW: + /* Seen it before? This can happen for loopback, retrans, + * or local packets. + */ + if (!nf_nat_initialized(ct, maniptype)) { + unsigned int ret; + + ret = do_chain(ops, skb, in, out, ct); + if (ret != NF_ACCEPT) + return ret; + + if (nf_nat_initialized(ct, HOOK2MANIP(ops->hooknum))) + break; + + ret = nf_nat_alloc_null_binding(ct, ops->hooknum); + if (ret != NF_ACCEPT) + return ret; + } else { + pr_debug("Already setup manip %s for ct %p\n", + maniptype == NF_NAT_MANIP_SRC ? "SRC" : "DST", + ct); + if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) + goto oif_changed; + } + break; + + default: + /* ESTABLISHED */ + NF_CT_ASSERT(ctinfo == IP_CT_ESTABLISHED || + ctinfo == IP_CT_ESTABLISHED_REPLY); + if (nf_nat_oif_changed(ops->hooknum, ctinfo, nat, out)) + goto oif_changed; + } + + return nf_nat_packet(ct, ctinfo, ops->hooknum, skb); + +oif_changed: + nf_ct_kill_acct(ct, ctinfo, skb); + return NF_DROP; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv4_fn); + +unsigned int +nf_nat_ipv4_in(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ + unsigned int ret; + __be32 daddr = ip_hdr(skb)->daddr; + + ret = nf_nat_ipv4_fn(ops, skb, in, out, do_chain); + if (ret != NF_DROP && ret != NF_STOLEN && + daddr != ip_hdr(skb)->daddr) + skb_dst_drop(skb); + + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv4_in); + +unsigned int +nf_nat_ipv4_out(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ +#ifdef CONFIG_XFRM + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + int err; +#endif + unsigned int ret; + + /* root is playing with raw sockets. */ + if (skb->len < sizeof(struct iphdr) || + ip_hdrlen(skb) < sizeof(struct iphdr)) + return NF_ACCEPT; + + ret = nf_nat_ipv4_fn(ops, skb, in, out, do_chain); +#ifdef CONFIG_XFRM + if (ret != NF_DROP && ret != NF_STOLEN && + !(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && + (ct = nf_ct_get(skb, &ctinfo)) != NULL) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if ((ct->tuplehash[dir].tuple.src.u3.ip != + ct->tuplehash[!dir].tuple.dst.u3.ip) || + (ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && + ct->tuplehash[dir].tuple.src.u.all != + ct->tuplehash[!dir].tuple.dst.u.all)) { + err = nf_xfrm_me_harder(skb, AF_INET); + if (err < 0) + ret = NF_DROP_ERR(err); + } + } +#endif + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv4_out); + +unsigned int +nf_nat_ipv4_local_fn(const struct nf_hook_ops *ops, struct sk_buff *skb, + const struct net_device *in, const struct net_device *out, + unsigned int (*do_chain)(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct)) +{ + const struct nf_conn *ct; + enum ip_conntrack_info ctinfo; + unsigned int ret; + int err; + + /* root is playing with raw sockets. */ + if (skb->len < sizeof(struct iphdr) || + ip_hdrlen(skb) < sizeof(struct iphdr)) + return NF_ACCEPT; + + ret = nf_nat_ipv4_fn(ops, skb, in, out, do_chain); + if (ret != NF_DROP && ret != NF_STOLEN && + (ct = nf_ct_get(skb, &ctinfo)) != NULL) { + enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); + + if (ct->tuplehash[dir].tuple.dst.u3.ip != + ct->tuplehash[!dir].tuple.src.u3.ip) { + err = ip_route_me_harder(skb, RTN_UNSPEC); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#ifdef CONFIG_XFRM + else if (!(IPCB(skb)->flags & IPSKB_XFRM_TRANSFORMED) && + ct->tuplehash[dir].tuple.dst.protonum != IPPROTO_ICMP && + ct->tuplehash[dir].tuple.dst.u.all != + ct->tuplehash[!dir].tuple.src.u.all) { + err = nf_xfrm_me_harder(skb, AF_INET); + if (err < 0) + ret = NF_DROP_ERR(err); + } +#endif + } + return ret; +} +EXPORT_SYMBOL_GPL(nf_nat_ipv4_local_fn); + static int __init nf_nat_l3proto_ipv4_init(void) { int err; diff --git a/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c new file mode 100644 index 000000000000..c6eb42100e9a --- /dev/null +++ b/net/ipv4/netfilter/nf_nat_masquerade_ipv4.c @@ -0,0 +1,153 @@ +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2006 Netfilter Core Team <coreteam@netfilter.org> + * + * 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/types.h> +#include <linux/module.h> +#include <linux/atomic.h> +#include <linux/inetdevice.h> +#include <linux/ip.h> +#include <linux/timer.h> +#include <linux/netfilter.h> +#include <net/protocol.h> +#include <net/ip.h> +#include <net/checksum.h> +#include <net/route.h> +#include <linux/netfilter_ipv4.h> +#include <linux/netfilter/x_tables.h> +#include <net/netfilter/nf_nat.h> +#include <net/netfilter/ipv4/nf_nat_masquerade.h> + +unsigned int +nf_nat_masquerade_ipv4(struct sk_buff *skb, unsigned int hooknum, + const struct nf_nat_range *range, + const struct net_device *out) +{ + struct nf_conn *ct; + struct nf_conn_nat *nat; + enum ip_conntrack_info ctinfo; + struct nf_nat_range newrange; + const struct rtable *rt; + __be32 newsrc, nh; + + NF_CT_ASSERT(hooknum == NF_INET_POST_ROUTING); + + ct = nf_ct_get(skb, &ctinfo); + nat = nfct_nat(ct); + + NF_CT_ASSERT(ct && (ctinfo == IP_CT_NEW || ctinfo == IP_CT_RELATED || + ctinfo == IP_CT_RELATED_REPLY)); + + /* Source address is 0.0.0.0 - locally generated packet that is + * probably not supposed to be masqueraded. + */ + if (ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple.src.u3.ip == 0) + return NF_ACCEPT; + + rt = skb_rtable(skb); + nh = rt_nexthop(rt, ip_hdr(skb)->daddr); + newsrc = inet_select_addr(out, nh, RT_SCOPE_UNIVERSE); + if (!newsrc) { + pr_info("%s ate my IP address\n", out->name); + return NF_DROP; + } + + nat->masq_index = out->ifindex; + + /* Transfer from original range. */ + memset(&newrange.min_addr, 0, sizeof(newrange.min_addr)); + memset(&newrange.max_addr, 0, sizeof(newrange.max_addr)); + newrange.flags = range->flags | NF_NAT_RANGE_MAP_IPS; + newrange.min_addr.ip = newsrc; + newrange.max_addr.ip = newsrc; + newrange.min_proto = range->min_proto; + newrange.max_proto = range->max_proto; + + /* Hand modified range to generic setup. */ + return nf_nat_setup_info(ct, &newrange, NF_NAT_MANIP_SRC); +} +EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4); + +static int device_cmp(struct nf_conn *i, void *ifindex) +{ + const struct nf_conn_nat *nat = nfct_nat(i); + + if (!nat) + return 0; + if (nf_ct_l3num(i) != NFPROTO_IPV4) + return 0; + return nat->masq_index == (int)(long)ifindex; +} + +static int masq_device_event(struct notifier_block *this, + unsigned long event, + void *ptr) +{ + const struct net_device *dev = netdev_notifier_info_to_dev(ptr); + struct net *net = dev_net(dev); + + if (event == NETDEV_DOWN) { + /* Device was downed. Search entire table for + * conntracks which were associated with that device, + * and forget them. + */ + NF_CT_ASSERT(dev->ifindex != 0); + + nf_ct_iterate_cleanup(net, device_cmp, + (void *)(long)dev->ifindex, 0, 0); + } + + return NOTIFY_DONE; +} + +static int masq_inet_event(struct notifier_block *this, + unsigned long event, + void *ptr) +{ + struct net_device *dev = ((struct in_ifaddr *)ptr)->ifa_dev->dev; + struct netdev_notifier_info info; + + netdev_notifier_info_init(&info, dev); + return masq_device_event(this, event, &info); +} + +static struct notifier_block masq_dev_notifier = { + .notifier_call = masq_device_event, +}; + +static struct notifier_block masq_inet_notifier = { + .notifier_call = masq_inet_event, +}; + +static atomic_t masquerade_notifier_refcount = ATOMIC_INIT(0); + +void nf_nat_masquerade_ipv4_register_notifier(void) +{ + /* check if the notifier was already set */ + if (atomic_inc_return(&masquerade_notifier_refcount) > 1) + return; + + /* Register for device down reports */ + register_netdevice_notifier(&masq_dev_notifier); + /* Register IP address change reports */ + register_inetaddr_notifier(&masq_inet_notifier); +} +EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_register_notifier); + +void nf_nat_masquerade_ipv4_unregister_notifier(void) +{ + /* check if the notifier still has clients */ + if (atomic_dec_return(&masquerade_notifier_refcount) > 0) + return; + + unregister_netdevice_notifier(&masq_dev_notifier); + unregister_inetaddr_notifier(&masq_inet_notifier); +} +EXPORT_SYMBOL_GPL(nf_nat_masquerade_ipv4_unregister_notifier); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Rusty Russell <rusty@rustcorp.com.au>"); diff --git a/net/ipv4/netfilter/nft_chain_nat_ipv4.c b/net/ipv4/netfilter/nft_chain_nat_ipv4.c index 3964157d826c..df547bf50078 100644 --- a/net/ipv4/netfilter/nft_chain_nat_ipv4.c +++ b/net/ipv4/netfilter/nft_chain_nat_ipv4.c @@ -26,136 +26,53 @@ #include <net/netfilter/nf_nat_l3proto.h> #include <net/ip.h> -/* - * NAT chains - */ - -static unsigned int nf_nat_fn(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_do_chain(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + struct nf_conn *ct) { - enum ip_conntrack_info ctinfo; - struct nf_conn *ct = nf_ct_get(skb, &ctinfo); - struct nf_conn_nat *nat; - enum nf_nat_manip_type maniptype = HOOK2MANIP(ops->hooknum); struct nft_pktinfo pkt; - unsigned int ret; - - if (ct == NULL || nf_ct_is_untracked(ct)) - return NF_ACCEPT; - - NF_CT_ASSERT(!(ip_hdr(skb)->frag_off & htons(IP_MF | IP_OFFSET))); - - nat = nf_ct_nat_ext_add(ct); - if (nat == NULL) - return NF_ACCEPT; - - switch (ctinfo) { - case IP_CT_RELATED: - case IP_CT_RELATED + IP_CT_IS_REPLY: - if (ip_hdr(skb)->protocol == IPPROTO_ICMP) { - if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo, - ops->hooknum)) - return NF_DROP; - else - return NF_ACCEPT; - } - /* Fall through */ - case IP_CT_NEW: - if (nf_nat_initialized(ct, maniptype)) - break; - nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out); + nft_set_pktinfo_ipv4(&pkt, ops, skb, in, out); - ret = nft_do_chain(&pkt, ops); - if (ret != NF_ACCEPT) - return ret; - if (!nf_nat_initialized(ct, maniptype)) { - ret = nf_nat_alloc_null_binding(ct, ops->hooknum); - if (ret != NF_ACCEPT) - return ret; - } - default: - break; - } - - return nf_nat_packet(ct, ctinfo, ops->hooknum, skb); + return nft_do_chain(&pkt, ops); } -static unsigned int nf_nat_prerouting(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_ipv4_fn(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - __be32 daddr = ip_hdr(skb)->daddr; - unsigned int ret; - - ret = nf_nat_fn(ops, skb, in, out, okfn); - if (ret != NF_DROP && ret != NF_STOLEN && - ip_hdr(skb)->daddr != daddr) { - skb_dst_drop(skb); - } - return ret; + return nf_nat_ipv4_fn(ops, skb, in, out, nft_nat_do_chain); } -static unsigned int nf_nat_postrouting(const struct nf_hook_ops *ops, - struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - int (*okfn)(struct sk_buff *)) +static unsigned int nft_nat_ipv4_in(const struct nf_hook_ops *ops, + struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + int (*okfn)(struct sk_buff *)) { - enum ip_conntrack_info ctinfo __maybe_unused; - const struct nf_conn *ct __maybe_unused; - unsigned int ret; - - ret = nf_nat_fn(ops, skb, in, out, okfn); -#ifdef CONFIG_XFRM - if (ret != NF_DROP && ret != NF_STOLEN && - (ct = nf_ct_get(skb, &ctinfo)) != NULL) { - enum ip_conntrack_dir dir = CTINFO2DIR(ctinfo); - - if (ct->tuplehash[dir].tuple.src.u3.ip != - ct->tuplehash[!dir].tuple.dst.u3.ip || - ct->tuplehash[dir].tuple.src.u.all != - ct->tuplehash[!dir].tuple.dst.u.all) - return nf_xfrm_me_harder(skb, AF_INET) == 0 ? - ret : NF_DROP; - } -#endif - return ret; + return nf_nat_ipv4_in(ops, skb, in, out, nft_nat_do_chain); } -static unsigned int nf_nat_output(const struct nf_hook_ops *ops, |