diff --git a/include/linux/netfilter_ipv6.h b/include/linux/netfilter_ipv6.h index 12113e502656..a21b8c9623ee 100644 --- a/include/linux/netfilter_ipv6.h +++ b/include/linux/netfilter_ipv6.h @@ -19,6 +19,7 @@ struct ip6_rt_info { }; struct nf_queue_entry; +struct nf_ct_bridge_frag_data; /* * Hook functions for ipv6 to allow xt_* modules to be built-in even @@ -39,6 +40,15 @@ struct nf_ipv6_ops { int (*fragment)(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)); int (*reroute)(struct sk_buff *skb, const struct nf_queue_entry *entry); +#if IS_MODULE(CONFIG_IPV6) + int (*br_defrag)(struct net *net, struct sk_buff *skb, u32 user); + int (*br_fragment)(struct net *net, struct sock *sk, + struct sk_buff *skb, + struct nf_ct_bridge_frag_data *data, + int (*output)(struct net *, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *)); +#endif }; #ifdef CONFIG_NETFILTER @@ -86,6 +96,46 @@ static inline int nf_ip6_route(struct net *net, struct dst_entry **dst, #endif } +static inline int nf_ipv6_br_defrag(struct net *net, struct sk_buff *skb, + u32 user) +{ +#if IS_MODULE(CONFIG_IPV6) + const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops(); + + if (!v6_ops) + return 1; + + return v6_ops->br_defrag(net, skb, user); +#else + return nf_ct_frag6_gather(net, skb, user); +#endif +} + +int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, + struct nf_ct_bridge_frag_data *data, + int (*output)(struct net *, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *)); + +static inline int nf_br_ip6_fragment(struct net *net, struct sock *sk, + struct sk_buff *skb, + struct nf_ct_bridge_frag_data *data, + int (*output)(struct net *, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *)) +{ +#if IS_MODULE(CONFIG_IPV6) + const struct nf_ipv6_ops *v6_ops = nf_get_ipv6_ops(); + + if (!v6_ops) + return 1; + + return v6_ops->br_fragment(net, sk, skb, data, output); +#else + return br_ip6_fragment(net, sk, skb, data, output); +#endif +} + int ip6_route_me_harder(struct net *net, struct sk_buff *skb); static inline int nf_ip6_route_me_harder(struct net *net, struct sk_buff *skb) diff --git a/include/net/ip.h b/include/net/ip.h index 2d3cce7c3e8a..029cc3fd26bd 100644 --- a/include/net/ip.h +++ b/include/net/ip.h @@ -165,6 +165,45 @@ int ip_output(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_mc_output(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)); + +struct ip_fraglist_iter { + struct sk_buff *frag_list; + struct sk_buff *frag; + struct iphdr *iph; + int offset; + unsigned int hlen; +}; + +void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, + unsigned int hlen, struct ip_fraglist_iter *iter); +void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter); + +static inline struct sk_buff *ip_fraglist_next(struct ip_fraglist_iter *iter) +{ + struct sk_buff *skb = iter->frag; + + iter->frag = skb->next; + skb_mark_not_on_list(skb); + + return skb; +} + +struct ip_frag_state { + struct iphdr *iph; + unsigned int hlen; + unsigned int ll_rs; + unsigned int mtu; + unsigned int left; + int offset; + int ptr; + __be16 not_last_frag; +}; + +void ip_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int ll_rs, + unsigned int mtu, struct ip_frag_state *state); +struct sk_buff *ip_frag_next(struct sk_buff *skb, + struct ip_frag_state *state); + void ip_send_check(struct iphdr *ip); int __ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); int ip_local_out(struct net *net, struct sock *sk, struct sk_buff *skb); diff --git a/include/net/ipv6.h b/include/net/ipv6.h index daf80863d3a5..21bb830e9679 100644 --- a/include/net/ipv6.h +++ b/include/net/ipv6.h @@ -154,6 +154,50 @@ struct frag_hdr { #define IP6_MF 0x0001 #define IP6_OFFSET 0xFFF8 +struct ip6_fraglist_iter { + struct ipv6hdr *tmp_hdr; + struct sk_buff *frag_list; + struct sk_buff *frag; + int offset; + unsigned int hlen; + __be32 frag_id; + u8 nexthdr; +}; + +int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, + u8 nexthdr, __be32 frag_id, + struct ip6_fraglist_iter *iter); +void ip6_fraglist_prepare(struct sk_buff *skb, struct ip6_fraglist_iter *iter); + +static inline struct sk_buff *ip6_fraglist_next(struct ip6_fraglist_iter *iter) +{ + struct sk_buff *skb = iter->frag; + + iter->frag = skb->next; + skb_mark_not_on_list(skb); + + return skb; +} + +struct ip6_frag_state { + u8 *prevhdr; + unsigned int hlen; + unsigned int mtu; + unsigned int left; + int offset; + int ptr; + int hroom; + int troom; + __be32 frag_id; + u8 nexthdr; +}; + +void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, + unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, + u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state); +struct sk_buff *ip6_frag_next(struct sk_buff *skb, + struct ip6_frag_state *state); + #define IP6_REPLY_MARK(net, mark) \ ((net)->ipv6.sysctl.fwmark_reflect ? (mark) : 0) diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h index d2bc733a2ef1..5cb19ce454d1 100644 --- a/include/net/netfilter/nf_conntrack.h +++ b/include/net/netfilter/nf_conntrack.h @@ -49,6 +49,7 @@ union nf_conntrack_expect_proto { struct nf_conntrack_net { unsigned int users4; unsigned int users6; + unsigned int users_bridge; }; #include diff --git a/include/net/netfilter/nf_conntrack_bridge.h b/include/net/netfilter/nf_conntrack_bridge.h new file mode 100644 index 000000000000..9a5514d5bc51 --- /dev/null +++ b/include/net/netfilter/nf_conntrack_bridge.h @@ -0,0 +1,20 @@ +#ifndef NF_CONNTRACK_BRIDGE_ +#define NF_CONNTRACK_BRIDGE_ + +struct nf_ct_bridge_info { + struct nf_hook_ops *ops; + unsigned int ops_size; + struct module *me; +}; + +void nf_ct_bridge_register(struct nf_ct_bridge_info *info); +void nf_ct_bridge_unregister(struct nf_ct_bridge_info *info); + +struct nf_ct_bridge_frag_data { + char mac[ETH_HLEN]; + bool vlan_present; + u16 vlan_tci; + __be16 vlan_proto; +}; + +#endif diff --git a/include/net/netfilter/nf_conntrack_core.h b/include/net/netfilter/nf_conntrack_core.h index ae41e92251dd..de10faf2ce91 100644 --- a/include/net/netfilter/nf_conntrack_core.h +++ b/include/net/netfilter/nf_conntrack_core.h @@ -64,6 +64,9 @@ static inline int nf_conntrack_confirm(struct sk_buff *skb) return ret; } +unsigned int nf_confirm(struct sk_buff *skb, unsigned int protoff, + struct nf_conn *ct, enum ip_conntrack_info ctinfo); + void print_tuple(struct seq_file *s, const struct nf_conntrack_tuple *tuple, const struct nf_conntrack_l4proto *proto); diff --git a/net/bridge/br_device.c b/net/bridge/br_device.c index 013323b6dbe4..693aefad7f8a 100644 --- a/net/bridge/br_device.c +++ b/net/bridge/br_device.c @@ -56,6 +56,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev) br_switchdev_frame_unmark(skb); BR_INPUT_SKB_CB(skb)->brdev = dev; + BR_INPUT_SKB_CB(skb)->frag_max_size = 0; skb_reset_mac_header(skb); eth = eth_hdr(skb); diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h index 334a8c496b50..68561741e827 100644 --- a/net/bridge/br_private.h +++ b/net/bridge/br_private.h @@ -425,6 +425,7 @@ struct net_bridge { struct br_input_skb_cb { struct net_device *brdev; + u16 frag_max_size; #ifdef CONFIG_BRIDGE_IGMP_SNOOPING u8 igmp; u8 mrouters_only:1; diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig index c3ad90c43801..f4fb0b9b927d 100644 --- a/net/bridge/netfilter/Kconfig +++ b/net/bridge/netfilter/Kconfig @@ -19,6 +19,20 @@ config NF_LOG_BRIDGE tristate "Bridge packet logging" select NF_LOG_COMMON +config NF_CONNTRACK_BRIDGE + tristate "IPv4/IPV6 bridge connection tracking support" + depends on NF_CONNTRACK + default n + help + Connection tracking keeps a record of what packets have passed + through your machine, in order to figure out how they are related + into connections. This is used to enhance packet filtering via + stateful policies. Enable this if you want native tracking from + the bridge. This provides a replacement for the `br_netfilter' + infrastructure. + + To compile it as a module, choose M here. If unsure, say N. + endif # NF_TABLES_BRIDGE menuconfig BRIDGE_NF_EBTABLES diff --git a/net/bridge/netfilter/Makefile b/net/bridge/netfilter/Makefile index 9b868861f21a..9d7767322a64 100644 --- a/net/bridge/netfilter/Makefile +++ b/net/bridge/netfilter/Makefile @@ -5,6 +5,9 @@ obj-$(CONFIG_NFT_BRIDGE_REJECT) += nft_reject_bridge.o +# connection tracking +obj-$(CONFIG_NF_CONNTRACK_BRIDGE) += nf_conntrack_bridge.o + # packet logging obj-$(CONFIG_NF_LOG_BRIDGE) += nf_log_bridge.o diff --git a/net/bridge/netfilter/nf_conntrack_bridge.c b/net/bridge/netfilter/nf_conntrack_bridge.c new file mode 100644 index 000000000000..b675cd7c1a82 --- /dev/null +++ b/net/bridge/netfilter/nf_conntrack_bridge.c @@ -0,0 +1,433 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +#include +#include +#include + +#include "../br_private.h" + +/* Best effort variant of ip_do_fragment which preserves geometry, unless skbuff + * has been linearized or cloned. + */ +static int nf_br_ip_fragment(struct net *net, struct sock *sk, + struct sk_buff *skb, + struct nf_ct_bridge_frag_data *data, + int (*output)(struct net *, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *)) +{ + int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; + unsigned int hlen, ll_rs, mtu; + struct ip_frag_state state; + struct iphdr *iph; + int err; + + /* for offloaded checksums cleanup checksum before fragmentation */ + if (skb->ip_summed == CHECKSUM_PARTIAL && + (err = skb_checksum_help(skb))) + goto blackhole; + + iph = ip_hdr(skb); + + /* + * Setup starting values + */ + + hlen = iph->ihl * 4; + frag_max_size -= hlen; + ll_rs = LL_RESERVED_SPACE(skb->dev); + mtu = skb->dev->mtu; + + if (skb_has_frag_list(skb)) { + unsigned int first_len = skb_pagelen(skb); + struct ip_fraglist_iter iter; + struct sk_buff *frag; + + if (first_len - hlen > mtu || + skb_headroom(skb) < ll_rs) + goto blackhole; + + if (skb_cloned(skb)) + goto slow_path; + + skb_walk_frags(skb, frag) { + if (frag->len > mtu || + skb_headroom(frag) < hlen + ll_rs) + goto blackhole; + + if (skb_shared(frag)) + goto slow_path; + } + + ip_fraglist_init(skb, iph, hlen, &iter); + + for (;;) { + if (iter.frag) + ip_fraglist_prepare(skb, &iter); + + err = output(net, sk, data, skb); + if (err || !iter.frag) + break; + + skb = ip_fraglist_next(&iter); + } + return err; + } +slow_path: + /* This is a linearized skbuff, the original geometry is lost for us. + * This may also be a clone skbuff, we could preserve the geometry for + * the copies but probably not worth the effort. + */ + ip_frag_init(skb, hlen, ll_rs, frag_max_size, &state); + + while (state.left > 0) { + struct sk_buff *skb2; + + skb2 = ip_frag_next(skb, &state); + if (IS_ERR(skb2)) { + err = PTR_ERR(skb2); + goto blackhole; + } + + err = output(net, sk, data, skb2); + if (err) + goto blackhole; + } + consume_skb(skb); + return err; + +blackhole: + kfree_skb(skb); + return 0; +} + +/* ip_defrag() expects IPCB() in place. */ +static void br_skb_cb_save(struct sk_buff *skb, struct br_input_skb_cb *cb, + size_t inet_skb_parm_size) +{ + memcpy(cb, skb->cb, sizeof(*cb)); + memset(skb->cb, 0, inet_skb_parm_size); +} + +static void br_skb_cb_restore(struct sk_buff *skb, + const struct br_input_skb_cb *cb, + u16 fragsz) +{ + memcpy(skb->cb, cb, sizeof(*cb)); + BR_INPUT_SKB_CB(skb)->frag_max_size = fragsz; +} + +static unsigned int nf_ct_br_defrag4(struct sk_buff *skb, + const struct nf_hook_state *state) +{ + u16 zone_id = NF_CT_DEFAULT_ZONE_ID; + enum ip_conntrack_info ctinfo; + struct br_input_skb_cb cb; + const struct nf_conn *ct; + int err; + + if (!ip_is_fragment(ip_hdr(skb))) + return NF_ACCEPT; + + ct = nf_ct_get(skb, &ctinfo); + if (ct) + zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo)); + + br_skb_cb_save(skb, &cb, sizeof(struct inet_skb_parm)); + local_bh_disable(); + err = ip_defrag(state->net, skb, + IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id); + local_bh_enable(); + if (!err) { + br_skb_cb_restore(skb, &cb, IPCB(skb)->frag_max_size); + skb->ignore_df = 1; + return NF_ACCEPT; + } + + return NF_STOLEN; +} + +static unsigned int nf_ct_br_defrag6(struct sk_buff *skb, + const struct nf_hook_state *state) +{ + u16 zone_id = NF_CT_DEFAULT_ZONE_ID; + enum ip_conntrack_info ctinfo; + struct br_input_skb_cb cb; + const struct nf_conn *ct; + int err; + + ct = nf_ct_get(skb, &ctinfo); + if (ct) + zone_id = nf_ct_zone_id(nf_ct_zone(ct), CTINFO2DIR(ctinfo)); + + br_skb_cb_save(skb, &cb, sizeof(struct inet6_skb_parm)); + + err = nf_ipv6_br_defrag(state->net, skb, + IP_DEFRAG_CONNTRACK_BRIDGE_IN + zone_id); + /* queued */ + if (err == -EINPROGRESS) + return NF_STOLEN; + + br_skb_cb_restore(skb, &cb, IP6CB(skb)->frag_max_size); + return err == 0 ? NF_ACCEPT : NF_DROP; +} + +static int nf_ct_br_ip_check(const struct sk_buff *skb) +{ + const struct iphdr *iph; + int nhoff, len; + + nhoff = skb_network_offset(skb); + iph = ip_hdr(skb); + if (iph->ihl < 5 || + iph->version != 4) + return -1; + + len = ntohs(iph->tot_len); + if (skb->len < nhoff + len || + len < (iph->ihl * 4)) + return -1; + + return 0; +} + +static int nf_ct_br_ipv6_check(const struct sk_buff *skb) +{ + const struct ipv6hdr *hdr; + int nhoff, len; + + nhoff = skb_network_offset(skb); + hdr = ipv6_hdr(skb); + if (hdr->version != 6) + return -1; + + len = ntohs(hdr->payload_len) + sizeof(struct ipv6hdr) + nhoff; + if (skb->len < len) + return -1; + + return 0; +} + +static unsigned int nf_ct_bridge_pre(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct nf_hook_state bridge_state = *state; + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + u32 len; + int ret; + + ct = nf_ct_get(skb, &ctinfo); + if ((ct && !nf_ct_is_template(ct)) || + ctinfo == IP_CT_UNTRACKED) + return NF_ACCEPT; + + switch (skb->protocol) { + case htons(ETH_P_IP): + if (!pskb_may_pull(skb, sizeof(struct iphdr))) + return NF_ACCEPT; + + len = ntohs(ip_hdr(skb)->tot_len); + if (pskb_trim_rcsum(skb, len)) + return NF_ACCEPT; + + if (nf_ct_br_ip_check(skb)) + return NF_ACCEPT; + + bridge_state.pf = NFPROTO_IPV4; + ret = nf_ct_br_defrag4(skb, &bridge_state); + break; + case htons(ETH_P_IPV6): + if (!pskb_may_pull(skb, sizeof(struct ipv6hdr))) + return NF_ACCEPT; + + len = sizeof(struct ipv6hdr) + ntohs(ipv6_hdr(skb)->payload_len); + if (pskb_trim_rcsum(skb, len)) + return NF_ACCEPT; + + if (nf_ct_br_ipv6_check(skb)) + return NF_ACCEPT; + + bridge_state.pf = NFPROTO_IPV6; + ret = nf_ct_br_defrag6(skb, &bridge_state); + break; + default: + nf_ct_set(skb, NULL, IP_CT_UNTRACKED); + return NF_ACCEPT; + } + + if (ret != NF_ACCEPT) + return ret; + + return nf_conntrack_in(skb, &bridge_state); +} + +static void nf_ct_bridge_frag_save(struct sk_buff *skb, + struct nf_ct_bridge_frag_data *data) +{ + if (skb_vlan_tag_present(skb)) { + data->vlan_present = true; + data->vlan_tci = skb->vlan_tci; + data->vlan_proto = skb->vlan_proto; + } else { + data->vlan_present = false; + } + skb_copy_from_linear_data_offset(skb, -ETH_HLEN, data->mac, ETH_HLEN); +} + +static unsigned int +nf_ct_bridge_refrag(struct sk_buff *skb, const struct nf_hook_state *state, + int (*output)(struct net *, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *)) +{ + struct nf_ct_bridge_frag_data data; + + if (!BR_INPUT_SKB_CB(skb)->frag_max_size) + return NF_ACCEPT; + + nf_ct_bridge_frag_save(skb, &data); + switch (skb->protocol) { + case htons(ETH_P_IP): + nf_br_ip_fragment(state->net, state->sk, skb, &data, output); + break; + case htons(ETH_P_IPV6): + nf_br_ip6_fragment(state->net, state->sk, skb, &data, output); + break; + default: + WARN_ON_ONCE(1); + return NF_DROP; + } + + return NF_STOLEN; +} + +/* Actually only slow path refragmentation needs this. */ +static int nf_ct_bridge_frag_restore(struct sk_buff *skb, + const struct nf_ct_bridge_frag_data *data) +{ + int err; + + err = skb_cow_head(skb, ETH_HLEN); + if (err) { + kfree_skb(skb); + return -ENOMEM; + } + if (data->vlan_present) + __vlan_hwaccel_put_tag(skb, data->vlan_proto, data->vlan_tci); + + skb_copy_to_linear_data_offset(skb, -ETH_HLEN, data->mac, ETH_HLEN); + skb_reset_mac_header(skb); + + return 0; +} + +static int nf_ct_bridge_refrag_post(struct net *net, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *skb) +{ + int err; + + err = nf_ct_bridge_frag_restore(skb, data); + if (err < 0) + return err; + + return br_dev_queue_push_xmit(net, sk, skb); +} + +static unsigned int nf_ct_bridge_confirm(struct sk_buff *skb) +{ + enum ip_conntrack_info ctinfo; + struct nf_conn *ct; + int protoff; + + ct = nf_ct_get(skb, &ctinfo); + if (!ct || ctinfo == IP_CT_RELATED_REPLY) + return nf_conntrack_confirm(skb); + + switch (skb->protocol) { + case htons(ETH_P_IP): + protoff = skb_network_offset(skb) + ip_hdrlen(skb); + break; + case htons(ETH_P_IPV6): { + unsigned char pnum = ipv6_hdr(skb)->nexthdr; + __be16 frag_off; + + protoff = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &pnum, + &frag_off); + if (protoff < 0 || (frag_off & htons(~0x7)) != 0) + return nf_conntrack_confirm(skb); + } + break; + default: + return NF_ACCEPT; + } + return nf_confirm(skb, protoff, ct, ctinfo); +} + +static unsigned int nf_ct_bridge_post(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + int ret; + + ret = nf_ct_bridge_confirm(skb); + if (ret != NF_ACCEPT) + return ret; + + return nf_ct_bridge_refrag(skb, state, nf_ct_bridge_refrag_post); +} + +static struct nf_hook_ops nf_ct_bridge_hook_ops[] __read_mostly = { + { + .hook = nf_ct_bridge_pre, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_PRE_ROUTING, + .priority = NF_IP_PRI_CONNTRACK, + }, + { + .hook = nf_ct_bridge_post, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_POST_ROUTING, + .priority = NF_IP_PRI_CONNTRACK_CONFIRM, + }, +}; + +static struct nf_ct_bridge_info bridge_info = { + .ops = nf_ct_bridge_hook_ops, + .ops_size = ARRAY_SIZE(nf_ct_bridge_hook_ops), + .me = THIS_MODULE, +}; + +static int __init nf_conntrack_l3proto_bridge_init(void) +{ + nf_ct_bridge_register(&bridge_info); + + return 0; +} + +static void __exit nf_conntrack_l3proto_bridge_fini(void) +{ + nf_ct_bridge_unregister(&bridge_info); +} + +module_init(nf_conntrack_l3proto_bridge_init); +module_exit(nf_conntrack_l3proto_bridge_fini); + +MODULE_ALIAS("nf_conntrack-" __stringify(AF_BRIDGE)); +MODULE_LICENSE("GPL"); diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c index bfd0ca554977..8bae773cafbd 100644 --- a/net/ipv4/ip_output.c +++ b/net/ipv4/ip_output.c @@ -525,9 +525,6 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from) skb_copy_hash(to, from); - /* Copy the flags to each fragment. */ - IPCB(to)->flags = IPCB(from)->flags; - #ifdef CONFIG_NET_SCHED to->tc_index = from->tc_index; #endif @@ -561,6 +558,176 @@ static int ip_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, return ip_do_fragment(net, sk, skb, output); } +void ip_fraglist_init(struct sk_buff *skb, struct iphdr *iph, + unsigned int hlen, struct ip_fraglist_iter *iter) +{ + unsigned int first_len = skb_pagelen(skb); + + iter->frag_list = skb_shinfo(skb)->frag_list; + iter->frag = iter->frag_list; + skb_frag_list_init(skb); + + iter->offset = 0; + iter->iph = iph; + iter->hlen = hlen; + + skb->data_len = first_len - skb_headlen(skb); + skb->len = first_len; + iph->tot_len = htons(first_len); + iph->frag_off = htons(IP_MF); + ip_send_check(iph); +} +EXPORT_SYMBOL(ip_fraglist_init); + +static void ip_fraglist_ipcb_prepare(struct sk_buff *skb, + struct ip_fraglist_iter *iter) +{ + struct sk_buff *to = iter->frag; + + /* Copy the flags to each fragment. */ + IPCB(to)->flags = IPCB(skb)->flags; + + if (iter->offset == 0) + ip_options_fragment(to); +} + +void ip_fraglist_prepare(struct sk_buff *skb, struct ip_fraglist_iter *iter) +{ + unsigned int hlen = iter->hlen; + struct iphdr *iph = iter->iph; + struct sk_buff *frag; + + frag = iter->frag; + frag->ip_summed = CHECKSUM_NONE; + skb_reset_transport_header(frag); + __skb_push(frag, hlen); + skb_reset_network_header(frag); + memcpy(skb_network_header(frag), iph, hlen); + iter->iph = ip_hdr(frag); + iph = iter->iph; + iph->tot_len = htons(frag->len); + ip_copy_metadata(frag, skb); + iter->offset += skb->len - hlen; + iph->frag_off = htons(iter->offset >> 3); + if (frag->next) + iph->frag_off |= htons(IP_MF); + /* Ready, complete checksum */ + ip_send_check(iph); +} +EXPORT_SYMBOL(ip_fraglist_prepare); + +void ip_frag_init(struct sk_buff *skb, unsigned int hlen, + unsigned int ll_rs, unsigned int mtu, + struct ip_frag_state *state) +{ + struct iphdr *iph = ip_hdr(skb); + + state->hlen = hlen; + state->ll_rs = ll_rs; + state->mtu = mtu; + + state->left = skb->len - hlen; /* Space per frame */ + state->ptr = hlen; /* Where to start from */ + + state->offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; + state->not_last_frag = iph->frag_off & htons(IP_MF); +} +EXPORT_SYMBOL(ip_frag_init); + +static void ip_frag_ipcb(struct sk_buff *from, struct sk_buff *to, + bool first_frag, struct ip_frag_state *state) +{ + /* Copy the flags to each fragment. */ + IPCB(to)->flags = IPCB(from)->flags; + + if (IPCB(from)->flags & IPSKB_FRAG_PMTU) + state->iph->frag_off |= htons(IP_DF); + + /* ANK: dirty, but effective trick. Upgrade options only if + * the segment to be fragmented was THE FIRST (otherwise, + * options are already fixed) and make it ONCE + * on the initial skb, so that all the following fragments + * will inherit fixed options. + */ + if (first_frag) + ip_options_fragment(from); +} + +struct sk_buff *ip_frag_next(struct sk_buff *skb, struct ip_frag_state *state) +{ + unsigned int len = state->left; + struct sk_buff *skb2; + struct iphdr *iph; + + len = state->left; + /* IF: it doesn't fit, use 'mtu' - the data space left */ + if (len > state->mtu) + len = state->mtu; + /* IF: we are not sending up to and including the packet end + then align the next start on an eight byte boundary */ + if (len < state->left) { + len &= ~7; + } + + /* Allocate buffer */ + skb2 = alloc_skb(len + state->hlen + state->ll_rs, GFP_ATOMIC); + if (!skb2) + return ERR_PTR(-ENOMEM); + + /* + * Set up data on packet + */ + + ip_copy_metadata(skb2, skb); + skb_reserve(skb2, state->ll_rs); + skb_put(skb2, len + state->hlen); + skb_reset_network_header(skb2); + skb2->transport_header = skb2->network_header + state->hlen; + + /* + * Charge the memory for the fragment to any owner + * it might possess + */ + + if (skb->sk) + skb_set_owner_w(skb2, skb->sk); + + /* + * Copy the packet header into the new buffer. + */ + + skb_copy_from_linear_data(skb, skb_network_header(skb2), state->hlen); + + /* + * Copy a block of the IP datagram. + */ + if (skb_copy_bits(skb, state->ptr, skb_transport_header(skb2), len)) + BUG(); + state->left -= len; + + /* + * Fill in the new header fields. + */ + iph = ip_hdr(skb2); + iph->frag_off = htons((state->offset >> 3)); + + /* + * Added AC : If we are fragmenting a fragment that's not the + * last fragment then keep MF on each bit + */ + if (state->left > 0 || state->not_last_frag) + iph->frag_off |= htons(IP_MF); + state->ptr += len; + state->offset += len; + + iph->tot_len = htons(len + state->hlen); + + ip_send_check(iph); + + return skb2; +} +EXPORT_SYMBOL(ip_frag_next); + /* * This IP datagram is too large to be sent in one piece. Break it up into * smaller pieces (each of size equal to IP header plus @@ -572,12 +739,11 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)) { struct iphdr *iph; - int ptr; struct sk_buff *skb2; - unsigned int mtu, hlen, left, len, ll_rs; - int offset; - __be16 not_last_frag; struct rtable *rt = skb_rtable(skb); + unsigned int mtu, hlen, ll_rs; + struct ip_fraglist_iter iter; + struct ip_frag_state state; int err = 0; /* for offloaded checksums cleanup checksum before fragmentation */ @@ -642,49 +808,24 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, } /* Everything is OK. Generate! */ - - err = 0; - offset = 0; - frag = skb_shinfo(skb)->frag_list; - skb_frag_list_init(skb); - skb->data_len = first_len - skb_headlen(skb); - skb->len = first_len; - iph->tot_len = htons(first_len); - iph->frag_off = htons(IP_MF); - ip_send_check(iph); + ip_fraglist_init(skb, iph, hlen, &iter); for (;;) { /* Prepare header of the next frame, * before previous one went down. */ - if (frag) { - frag->ip_summed = CHECKSUM_NONE; - skb_reset_transport_header(frag); - __skb_push(frag, hlen); - skb_reset_network_header(frag); - memcpy(skb_network_header(frag), iph, hlen); - iph = ip_hdr(frag); - iph->tot_len = htons(frag->len); - ip_copy_metadata(frag, skb); - if (offset == 0) - ip_options_fragment(frag); - offset += skb->len - hlen; - iph->frag_off = htons(offset>>3); - if (frag->next) - iph->frag_off |= htons(IP_MF); - /* Ready, complete checksum */ - ip_send_check(iph); + if (iter.frag) { + ip_fraglist_ipcb_prepare(skb, &iter); + ip_fraglist_prepare(skb, &iter); } err = output(net, sk, skb); if (!err) IP_INC_STATS(net, IPSTATS_MIB_FRAGCREATES); - if (err || !frag) + if (err || !iter.frag) break; - skb = frag; - frag = skb->next; - skb_mark_not_on_list(skb); + skb = ip_fraglist_next(&iter); } if (err == 0) { @@ -692,7 +833,7 @@ int ip_do_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, return 0; } - kfree_skb_list(frag); + kfree_skb_list(iter.frag_list); IP_INC_STATS(net, IPSTATS_MIB_FRAGFAILS); return err; @@ -708,105 +849,29 @@ slow_path_clean: } slow_path: - iph = ip_hdr(skb); - - left = skb->len - hlen; /* Space per frame */ - ptr = hlen; /* Where to start from */ - /* * Fragment the datagram. */ - offset = (ntohs(iph->frag_off) & IP_OFFSET) << 3; - not_last_frag = iph->frag_off & htons(IP_MF); + ip_frag_init(skb, hlen, ll_rs, mtu, &state); /* * Keep copying data until we run out. */ - while (left > 0) { - len = left; - /* IF: it doesn't fit, use 'mtu' - the data space left */ - if (len > mtu) - len = mtu; - /* IF: we are not sending up to and including the packet end - then align the next start on an eight byte boundary */ - if (len < left) { - len &= ~7; - } + while (state.left > 0) { + bool first_frag = (state.offset == 0); - /* Allocate buffer */ - skb2 = alloc_skb(len + hlen + ll_rs, GFP_ATOMIC); - if (!skb2) { - err = -ENOMEM; + skb2 = ip_frag_next(skb, &state); + if (IS_ERR(skb2)) { + err = PTR_ERR(skb2); goto fail; } - - /* - * Set up data on packet - */ - - ip_copy_metadata(skb2, skb); - skb_reserve(skb2, ll_rs); - skb_put(skb2, len + hlen); - skb_reset_network_header(skb2); - skb2->transport_header = skb2->network_header + hlen; - - /* - * Charge the memory for the fragment to any owner - * it might possess - */ - - if (skb->sk) - skb_set_owner_w(skb2, skb->sk); - - /* - * Copy the packet header into the new buffer. - */ - - skb_copy_from_linear_data(skb, skb_network_header(skb2), hlen); - - /* - * Copy a block of the IP datagram. - */ - if (skb_copy_bits(skb, ptr, skb_transport_header(skb2), len)) - BUG(); - left -= len; - - /* - * Fill in the new header fields. - */ - iph = ip_hdr(skb2); - iph->frag_off = htons((offset >> 3)); - - if (IPCB(skb)->flags & IPSKB_FRAG_PMTU) - iph->frag_off |= htons(IP_DF); - - /* ANK: dirty, but effective trick. Upgrade options only if - * the segment to be fragmented was THE FIRST (otherwise, - * options are already fixed) and make it ONCE - * on the initial skb, so that all the following fragments - * will inherit fixed options. - */ - if (offset == 0) - ip_options_fragment(skb); - - /* - * Added AC : If we are fragmenting a fragment that's not the - * last fragment then keep MF on each bit - */ - if (left > 0 || not_last_frag) - iph->frag_off |= htons(IP_MF); - ptr += len; - offset += len; + ip_frag_ipcb(skb, skb2, first_frag, &state); /* * Put this fragment into the sending queue. */ - iph->tot_len = htons(len + hlen); - - ip_send_check(iph); - err = output(net, sk, skb2); if (err) goto fail; diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index adef2236abe2..812a98b79ec6 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c @@ -592,6 +592,170 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from) skb_copy_secmark(to, from); } +int ip6_fraglist_init(struct sk_buff *skb, unsigned int hlen, u8 *prevhdr, + u8 nexthdr, __be32 frag_id, + struct ip6_fraglist_iter *iter) +{ + unsigned int first_len; + struct frag_hdr *fh; + + /* BUILD HEADER */ + *prevhdr = NEXTHDR_FRAGMENT; + iter->tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); + if (!iter->tmp_hdr) + return -ENOMEM; + + iter->frag_list = skb_shinfo(skb)->frag_list; + iter->frag = iter->frag_list; + skb_frag_list_init(skb); + + iter->offset = 0; + iter->hlen = hlen; + iter->frag_id = frag_id; + iter->nexthdr = nexthdr; + + __skb_pull(skb, hlen); + fh = __skb_push(skb, sizeof(struct frag_hdr)); + __skb_push(skb, hlen); + skb_reset_network_header(skb); + memcpy(skb_network_header(skb), iter->tmp_hdr, hlen); + + fh->nexthdr = nexthdr; + fh->reserved = 0; + fh->frag_off = htons(IP6_MF); + fh->identification = frag_id; + + first_len = skb_pagelen(skb); + skb->data_len = first_len - skb_headlen(skb); + skb->len = first_len; + ipv6_hdr(skb)->payload_len = htons(first_len - sizeof(struct ipv6hdr)); + + return 0; +} +EXPORT_SYMBOL(ip6_fraglist_init); + +void ip6_fraglist_prepare(struct sk_buff *skb, + struct ip6_fraglist_iter *iter) +{ + struct sk_buff *frag = iter->frag; + unsigned int hlen = iter->hlen; + struct frag_hdr *fh; + + frag->ip_summed = CHECKSUM_NONE; + skb_reset_transport_header(frag); + fh = __skb_push(frag, sizeof(struct frag_hdr)); + __skb_push(frag, hlen); + skb_reset_network_header(frag); + memcpy(skb_network_header(frag), iter->tmp_hdr, hlen); + iter->offset += skb->len - hlen - sizeof(struct frag_hdr); + fh->nexthdr = iter->nexthdr; + fh->reserved = 0; + fh->frag_off = htons(iter->offset); + if (frag->next) + fh->frag_off |= htons(IP6_MF); + fh->identification = iter->frag_id; + ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); + ip6_copy_metadata(frag, skb); +} +EXPORT_SYMBOL(ip6_fraglist_prepare); + +void ip6_frag_init(struct sk_buff *skb, unsigned int hlen, unsigned int mtu, + unsigned short needed_tailroom, int hdr_room, u8 *prevhdr, + u8 nexthdr, __be32 frag_id, struct ip6_frag_state *state) +{ + state->prevhdr = prevhdr; + state->nexthdr = nexthdr; + state->frag_id = frag_id; + + state->hlen = hlen; + state->mtu = mtu; + + state->left = skb->len - hlen; /* Space per frame */ + state->ptr = hlen; /* Where to start from */ + + state->hroom = hdr_room; + state->troom = needed_tailroom; + + state->offset = 0; +} +EXPORT_SYMBOL(ip6_frag_init); + +struct sk_buff *ip6_frag_next(struct sk_buff *skb, struct ip6_frag_state *state) +{ + u8 *prevhdr = state->prevhdr, *fragnexthdr_offset; + struct sk_buff *frag; + struct frag_hdr *fh; + unsigned int len; + + len = state->left; + /* IF: it doesn't fit, use 'mtu' - the data space left */ + if (len > state->mtu) + len = state->mtu; + /* IF: we are not sending up to and including the packet end + then align the next start on an eight byte boundary */ + if (len < state->left) + len &= ~7; + + /* Allocate buffer */ + frag = alloc_skb(len + state->hlen + sizeof(struct frag_hdr) + + state->hroom + state->troom, GFP_ATOMIC); + if (!frag) + return ERR_PTR(-ENOMEM); + + /* + * Set up data on packet + */ + + ip6_copy_metadata(frag, skb); + skb_reserve(frag, state->hroom); + skb_put(frag, len + state->hlen + sizeof(struct frag_hdr)); + skb_reset_network_header(frag); + fh = (struct frag_hdr *)(skb_network_header(frag) + state->hlen); + frag->transport_header = (frag->network_header + state->hlen + + sizeof(struct frag_hdr)); + + /* + * Charge the memory for the fragment to any owner + * it might possess + */ + if (skb->sk) + skb_set_owner_w(frag, skb->sk); + + /* + * Copy the packet header into the new buffer. + */ + skb_copy_from_linear_data(skb, skb_network_header(frag), state->hlen); + + fragnexthdr_offset = skb_network_header(frag); + fragnexthdr_offset += prevhdr - skb_network_header(skb); + *fragnexthdr_offset = NEXTHDR_FRAGMENT; + + /* + * Build fragment header. + */ + fh->nexthdr = state->nexthdr; + fh->reserved = 0; + fh->identification = state->frag_id; + + /* + * Copy a block of the IP datagram. + */ + BUG_ON(skb_copy_bits(skb, state->ptr, skb_transport_header(frag), + len)); + state->left -= len; + + fh->frag_off = htons(state->offset); + if (state->left > 0) + fh->frag_off |= htons(IP6_MF); + ipv6_hdr(frag)->payload_len = htons(frag->len - sizeof(struct ipv6hdr)); + + state->ptr += len; + state->offset += len; + + return frag; +} +EXPORT_SYMBOL(ip6_frag_next); + int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, int (*output)(struct net *, struct sock *, struct sk_buff *)) { @@ -599,12 +763,10 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, struct rt6_info *rt = (struct rt6_info *)skb_dst(skb); struct ipv6_pinfo *np = skb->sk && !dev_recursion_level() ? inet6_sk(skb->sk) : NULL; - struct ipv6hdr *tmp_hdr; - struct frag_hdr *fh; - unsigned int mtu, hlen, left, len, nexthdr_offset; - int hroom, troom; + struct ip6_frag_state state; + unsigned int mtu, hlen, nexthdr_offset; + int hroom, err = 0; __be32 frag_id; - int ptr, offset = 0, err = 0; u8 *prevhdr, nexthdr = 0; err = ip6_find_1stfragopt(skb, &prevhdr); @@ -651,6 +813,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, hroom = LL_RESERVED_SPACE(rt->dst.dev); if (skb_has_frag_list(skb)) { unsigned int first_len = skb_pagelen(skb); + struct ip6_fraglist_iter iter; struct sk_buff *frag2; if (first_len - hlen > mtu || @@ -678,74 +841,29 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, skb->truesize -= frag->truesize; } - err = 0; - offset = 0; - /* BUILD HEADER */ - - *prevhdr = NEXTHDR_FRAGMENT; - tmp_hdr = kmemdup(skb_network_header(skb), hlen, GFP_ATOMIC); - if (!tmp_hdr) { - err = -ENOMEM; + err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, + &iter); + if (err < 0) goto fail; - } - frag = skb_shinfo(skb)->frag_list; - skb_frag_list_init(skb); - - __skb_pull(skb, hlen); - fh = __skb_push(skb, sizeof(struct frag_hdr)); - __skb_push(skb, hlen); - skb_reset_network_header(skb); - memcpy(skb_network_header(skb), tmp_hdr, hlen); - - fh->nexthdr = nexthdr; - fh->reserved = 0; - fh->frag_off = htons(IP6_MF); - fh->identification = frag_id; - - first_len = skb_pagelen(skb); - skb->data_len = first_len - skb_headlen(skb); - skb->len = first_len; - ipv6_hdr(skb)->payload_len = htons(first_len - - sizeof(struct ipv6hdr)); for (;;) { /* Prepare header of the next frame, * before previous one went down. */ - if (frag) { - frag->ip_summed = CHECKSUM_NONE; - skb_reset_transport_header(frag); - fh = __skb_push(frag, sizeof(struct frag_hdr)); - __skb_push(frag, hlen); - skb_reset_network_header(frag); - memcpy(skb_network_header(frag), tmp_hdr, - hlen); - offset += skb->len - hlen - sizeof(struct frag_hdr); - fh->nexthdr = nexthdr; - fh->reserved = 0; - fh->frag_off = htons(offset); - if (frag->next) - fh->frag_off |= htons(IP6_MF); - fh->identification = frag_id; - ipv6_hdr(frag)->payload_len = - htons(frag->len - - sizeof(struct ipv6hdr)); - ip6_copy_metadata(frag, skb); - } + if (iter.frag) + ip6_fraglist_prepare(skb, &iter); err = output(net, sk, skb); if (!err) IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), IPSTATS_MIB_FRAGCREATES); - if (err || !frag) + if (err || !iter.frag) break; - skb = frag; - frag = skb->next; - skb_mark_not_on_list(skb); + skb = ip6_fraglist_next(&iter); } - kfree(tmp_hdr); + kfree(iter.tmp_hdr); if (err == 0) { IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), @@ -753,7 +871,7 @@ int ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, return 0; } - kfree_skb_list(frag); + kfree_skb_list(iter.frag_list); IP6_INC_STATS(net, ip6_dst_idev(&rt->dst), IPSTATS_MIB_FRAGFAILS); @@ -770,90 +888,25 @@ slow_path_clean: } slow_path: - left = skb->len - hlen; /* Space per frame */ - ptr = hlen; /* Where to start from */ - /* * Fragment the datagram. */ - troom = rt->dst.dev->needed_tailroom; + ip6_frag_init(skb, hlen, mtu, rt->dst.dev->needed_tailroom, + LL_RESERVED_SPACE(rt->dst.dev), prevhdr, nexthdr, frag_id, + &state); /* * Keep copying data until we run out. */ - while (left > 0) { - u8 *fragnexthdr_offset; - len = left; - /* IF: it doesn't fit, use 'mtu' - the data space left */ - if (len > mtu) - len = mtu; - /* IF: we are not sending up to and including the packet end - then align the next start on an eight byte boundary */ - if (len < left) { - len &= ~7; - } - - /* Allocate buffer */ - frag = alloc_skb(len + hlen + sizeof(struct frag_hdr) + - hroom + troom, GFP_ATOMIC); - if (!frag) { - err = -ENOMEM; + while (state.left > 0) { + frag = ip6_frag_next(skb, &state); + if (IS_ERR(frag)) { + err = PTR_ERR(frag); goto fail; } - /* - * Set up data on packet - */ - - ip6_copy_metadata(frag, skb); - skb_reserve(frag, hroom); - skb_put(frag, len + hlen + sizeof(struct frag_hdr)); - skb_reset_network_header(frag); - fh = (struct frag_hdr *)(skb_network_header(frag) + hlen); - frag->transport_header = (frag->network_header + hlen + - sizeof(struct frag_hdr)); - - /* - * Charge the memory for the fragment to any owner - * it might possess - */ - if (skb->sk) - skb_set_owner_w(frag, skb->sk); - - /* - * Copy the packet header into the new buffer. - */ - skb_copy_from_linear_data(skb, skb_network_header(frag), hlen); - - fragnexthdr_offset = skb_network_header(frag); - fragnexthdr_offset += prevhdr - skb_network_header(skb); - *fragnexthdr_offset = NEXTHDR_FRAGMENT; - - /* - * Build fragment header. - */ - fh->nexthdr = nexthdr; - fh->reserved = 0; - fh->identification = frag_id; - - /* - * Copy a block of the IP datagram. - */ - BUG_ON(skb_copy_bits(skb, ptr, skb_transport_header(frag), - len)); - left -= len; - - fh->frag_off = htons(offset); - if (left > 0) - fh->frag_off |= htons(IP6_MF); - ipv6_hdr(frag)->payload_len = htons(frag->len - - sizeof(struct ipv6hdr)); - - ptr += len; - offset += len; - /* * Put this fragment into the sending queue. */ diff --git a/net/ipv6/netfilter.c b/net/ipv6/netfilter.c index 1240ccd57f39..c6665382acb5 100644 --- a/net/ipv6/netfilter.c +++ b/net/ipv6/netfilter.c @@ -16,6 +16,9 @@ #include #include #include +#include +#include +#include "../bridge/br_private.h" int ip6_route_me_harder(struct net *net, struct sk_buff *skb) { @@ -109,6 +112,122 @@ int __nf_ip6_route(struct net *net, struct dst_entry **dst, } EXPORT_SYMBOL_GPL(__nf_ip6_route); +int br_ip6_fragment(struct net *net, struct sock *sk, struct sk_buff *skb, + struct nf_ct_bridge_frag_data *data, + int (*output)(struct net *, struct sock *sk, + const struct nf_ct_bridge_frag_data *data, + struct sk_buff *)) +{ + int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; + struct ip6_frag_state state; + u8 *prevhdr, nexthdr = 0; + unsigned int mtu, hlen; + int hroom, err = 0; + __be32 frag_id; + + err = ip6_find_1stfragopt(skb, &prevhdr); + if (err < 0) + goto blackhole; + hlen = err; + nexthdr = *prevhdr; + + mtu = skb->dev->mtu; + if (frag_max_size > mtu || + frag_max_size < IPV6_MIN_MTU) + goto blackhole; + + mtu = frag_max_size; + if (mtu < hlen + sizeof(struct frag_hdr) + 8) + goto blackhole; + mtu -= hlen + sizeof(struct frag_hdr); + + frag_id = ipv6_select_ident(net, &ipv6_hdr(skb)->daddr, + &ipv6_hdr(skb)->saddr); + + if (skb->ip_summed == CHECKSUM_PARTIAL && + (err = skb_checksum_help(skb))) + goto blackhole; + + hroom = LL_RESERVED_SPACE(skb->dev); + if (skb_has_frag_list(skb)) { + unsigned int first_len = skb_pagelen(skb); + struct ip6_fraglist_iter iter; + struct sk_buff *frag2; + + if (first_len - hlen > mtu || + skb_headroom(skb) < (hroom + sizeof(struct frag_hdr))) + goto blackhole; + + if (skb_cloned(skb)) + goto slow_path; + + skb_walk_frags(skb, frag2) { + if (frag2->len > mtu || + skb_headroom(frag2) < (hlen + hroom + sizeof(struct frag_hdr))) + goto blackhole; + + /* Partially cloned skb? */ + if (skb_shared(frag2)) + goto slow_path; + } + + err = ip6_fraglist_init(skb, hlen, prevhdr, nexthdr, frag_id, + &iter); + if (err < 0) + goto blackhole; + + for (;;) { + /* Prepare header of the next frame, + * before previous one went down. + */ + if (iter.frag) + ip6_fraglist_prepare(skb, &iter); + + err = output(net, sk, data, skb); + if (err || !iter.frag) + break; + + skb = ip6_fraglist_next(&iter); + } + + kfree(iter.tmp_hdr); + if (!err) + return 0; + + kfree_skb_list(iter.frag_list); + return err; + } +slow_path: + /* This is a linearized skbuff, the original geometry is lost for us. + * This may also be a clone skbuff, we could preserve the geometry for + * the copies but probably not worth the effort. + */ + ip6_frag_init(skb, hlen, mtu, skb->dev->needed_tailroom, + LL_RESERVED_SPACE(skb->dev), prevhdr, nexthdr, frag_id, + &state); + + while (state.left > 0) { + struct sk_buff *skb2; + + skb2 = ip6_frag_next(skb, &state); + if (IS_ERR(skb2)) { + err = PTR_ERR(skb2); + goto blackhole; + } + + err = output(net, sk, data, skb2); + if (err) + goto blackhole; + } + consume_skb(skb); + return err; + +blackhole: + kfree_skb(skb); + return 0; +} +EXPORT_SYMBOL_GPL(br_ip6_fragment); + static const struct nf_ipv6_ops ipv6ops = { #if IS_MODULE(CONFIG_IPV6) .chk_addr = ipv6_chk_addr, @@ -119,6 +238,10 @@ static const struct nf_ipv6_ops ipv6ops = { .route_input = ip6_route_input, .fragment = ip6_fragment, .reroute = nf_ip6_reroute, +#if IS_MODULE(CONFIG_NF_CONNTRACK_BRIDGE) + .br_defrag = nf_ct_frag6_gather, + .br_fragment = br_ip6_fragment, +#endif }; int __init ipv6_netfilter_init(void) diff --git a/net/netfilter/nf_conntrack_proto.c b/net/netfilter/nf_conntrack_proto.c index 37bb530d848f..a0560d175a7f 100644 --- a/net/netfilter/nf_conntrack_proto.c +++ b/net/netfilter/nf_conntrack_proto.c @@ -16,6 +16,7 @@ #include #include #include +#include #include #include @@ -120,10 +121,8 @@ const struct nf_conntrack_l4proto *nf_ct_l4proto_find(u8 l4proto) }; EXPORT_SYMBOL_GPL(nf_ct_l4proto_find); -static unsigned int nf_confirm(struct sk_buff *skb, - unsigned int protoff, - struct nf_conn *ct, - enum ip_conntrack_info ctinfo) +unsigned int nf_confirm(struct sk_buff *skb, unsigned int protoff, + struct nf_conn *ct, enum ip_conntrack_info ctinfo) { const struct nf_conn_help *help; @@ -154,6 +153,7 @@ static unsigned int nf_confirm(struct sk_buff *skb, /* We've seen it coming out the other side: confirm it */ return nf_conntrack_confirm(skb); } +EXPORT_SYMBOL_GPL(nf_confirm); static unsigned int ipv4_confirm(void *priv, struct sk_buff *skb, @@ -442,12 +442,14 @@ static int nf_ct_tcp_fixup(struct nf_conn *ct, void *_nfproto) return 0; } +static struct nf_ct_bridge_info *nf_ct_bridge_info; + static int nf_ct_netns_do_get(struct net *net, u8 nfproto) { struct nf_conntrack_net *cnet = net_generic(net, nf_conntrack_net_id); - bool fixup_needed = false; + bool fixup_needed = false, retry = true; int err = 0; - +retry: mutex_lock(&nf_ct_proto_mutex); switch (nfproto) { @@ -487,6 +489,32 @@ static int nf_ct_netns_do_get(struct net *net, u8 nfproto) fixup_needed = true; break; #endif + case NFPROTO_BRIDGE: + if (!nf_ct_bridge_info) { + if (!retry) { + err = -EPROTO; + goto out_unlock; + } + mutex_unlock(&nf_ct_proto_mutex); + request_module("nf_conntrack_bridge"); + retry = false; + goto retry; + } + if (!try_module_get(nf_ct_bridge_info->me)) { + err = -EPROTO; + goto out_unlock; + } + cnet->users_bridge++; + if (cnet->users_bridge > 1) + goto out_unlock; + + err = nf_register_net_hooks(net, nf_ct_bridge_info->ops, + nf_ct_bridge_info->ops_size); + if (err) + cnet->users_bridge = 0; + else + fixup_needed = true; + break; default: err = -EPROTO; break; @@ -519,47 +547,99 @@ static void nf_ct_netns_do_put(struct net *net, u8 nfproto) ARRAY_SIZE(ipv6_conntrack_ops)); break; #endif - } + case NFPROTO_BRIDGE: + if (!nf_ct_bridge_info) + break; + if (cnet->users_bridge && (--cnet->users_bridge == 0)) + nf_unregister_net_hooks(net, nf_ct_bridge_info->ops, + nf_ct_bridge_info->ops_size); + module_put(nf_ct_bridge_info->me); + break; + } mutex_unlock(&nf_ct_proto_mutex); } +static int nf_ct_netns_inet_get(struct net *net) +{ + int err; + + err = nf_ct_netns_do_get(net, NFPROTO_IPV4); + if (err < 0) + goto err1; + err = nf_ct_netns_do_get(net, NFPROTO_IPV6); + if (err < 0) + goto err2; + + return err; +err2: + nf_ct_netns_put(net, NFPROTO_IPV4); +err1: + return err; +} + int nf_ct_netns_get(struct net *net, u8 nfproto) { int err; - if (nfproto == NFPROTO_INET) { - err = nf_ct_netns_do_get(net, NFPROTO_IPV4); + switch (nfproto) { + case NFPROTO_INET: + err = nf_ct_netns_inet_get(net); + break; + case NFPROTO_BRIDGE: + err = nf_ct_netns_do_get(net, NFPROTO_BRIDGE); if (err < 0) - goto err1; - err = nf_ct_netns_do_get(net, NFPROTO_IPV6); - if (err < 0) - goto err2; - } else { - err = nf_ct_netns_do_get(net, nfproto); - if (err < 0) - goto err1; - } - return 0; + return err; -err2: - nf_ct_netns_put(net, NFPROTO_IPV4); -err1: + err = nf_ct_netns_inet_get(net); + if (err < 0) { + nf_ct_netns_put(net, NFPROTO_BRIDGE); + return err; + } + break; + default: + err = nf_ct_netns_do_get(net, nfproto); + break; + } return err; } EXPORT_SYMBOL_GPL(nf_ct_netns_get); void nf_ct_netns_put(struct net *net, uint8_t nfproto) { - if (nfproto == NFPROTO_INET) { + switch (nfproto) { + case NFPROTO_BRIDGE: + nf_ct_netns_do_put(net, NFPROTO_BRIDGE); + /* fall through */ + case NFPROTO_INET: nf_ct_netns_do_put(net, NFPROTO_IPV4); nf_ct_netns_do_put(net, NFPROTO_IPV6); - } else { + break; + default: nf_ct_netns_do_put(net, nfproto); + break; } } EXPORT_SYMBOL_GPL(nf_ct_netns_put); +void nf_ct_bridge_register(struct nf_ct_bridge_info *info) +{ + WARN_ON(nf_ct_bridge_info); + mutex_lock(&nf_ct_proto_mutex); + nf_ct_bridge_info = info; + mutex_unlock(&nf_ct_proto_mutex); +} +EXPORT_SYMBOL_GPL(nf_ct_bridge_register); + +void nf_ct_bridge_unregister(struct nf_ct_bridge_info *info) +{ + WARN_ON(!nf_ct_bridge_info); + mutex_lock(&nf_ct_proto_mutex); + nf_ct_bridge_info = NULL; + mutex_unlock(&nf_ct_proto_mutex); +} +EXPORT_SYMBOL_GPL(nf_ct_bridge_unregister); + int nf_conntrack_proto_init(void) { int ret;