diff options
Diffstat (limited to 'net/bridge/netfilter')
26 files changed, 6402 insertions, 0 deletions
diff --git a/net/bridge/netfilter/Kconfig b/net/bridge/netfilter/Kconfig new file mode 100644 index 000000000..7f304a19a --- /dev/null +++ b/net/bridge/netfilter/Kconfig @@ -0,0 +1,242 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# Bridge netfilter configuration +# +# +menuconfig NF_TABLES_BRIDGE + depends on BRIDGE && NETFILTER && NF_TABLES + select NETFILTER_FAMILY_BRIDGE + tristate "Ethernet Bridge nf_tables support" + +if NF_TABLES_BRIDGE + +config NFT_BRIDGE_META + tristate "Netfilter nf_table bridge meta support" + help + Add support for bridge dedicated meta key. + +config NFT_BRIDGE_REJECT + tristate "Netfilter nf_tables bridge reject support" + depends on NFT_REJECT + depends on NF_REJECT_IPV4 + depends on NF_REJECT_IPV6 + help + Add support to reject packets. + +endif # NF_TABLES_BRIDGE + +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. + +menuconfig BRIDGE_NF_EBTABLES + tristate "Ethernet Bridge tables (ebtables) support" + depends on BRIDGE && NETFILTER && NETFILTER_XTABLES + select NETFILTER_FAMILY_BRIDGE + help + ebtables is a general, extensible frame/packet identification + framework. Say 'Y' or 'M' here if you want to do Ethernet + filtering/NAT/brouting on the Ethernet bridge. + +if BRIDGE_NF_EBTABLES + +# +# tables +# +config BRIDGE_EBT_BROUTE + tristate "ebt: broute table support" + help + The ebtables broute table is used to define rules that decide between + bridging and routing frames, giving Linux the functionality of a + brouter. See the man page for ebtables(8) and examples on the ebtables + website. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_T_FILTER + tristate "ebt: filter table support" + help + The ebtables filter table is used to define frame filtering rules at + local input, forwarding and local output. See the man page for + ebtables(8). + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_T_NAT + tristate "ebt: nat table support" + help + The ebtables nat table is used to define rules that alter the MAC + source address (MAC SNAT) or the MAC destination address (MAC DNAT). + See the man page for ebtables(8). + + To compile it as a module, choose M here. If unsure, say N. +# +# matches +# +config BRIDGE_EBT_802_3 + tristate "ebt: 802.3 filter support" + help + This option adds matching support for 802.3 Ethernet frames. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_AMONG + tristate "ebt: among filter support" + help + This option adds the among match, which allows matching the MAC source + and/or destination address on a list of addresses. Optionally, + MAC/IP address pairs can be matched, f.e. for anti-spoofing rules. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_ARP + tristate "ebt: ARP filter support" + help + This option adds the ARP match, which allows ARP and RARP header field + filtering. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_IP + tristate "ebt: IP filter support" + help + This option adds the IP match, which allows basic IP header field + filtering. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_IP6 + tristate "ebt: IP6 filter support" + depends on BRIDGE_NF_EBTABLES && IPV6 + help + This option adds the IP6 match, which allows basic IPV6 header field + filtering. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_LIMIT + tristate "ebt: limit match support" + help + This option adds the limit match, which allows you to control + the rate at which a rule can be matched. This match is the + equivalent of the iptables limit match. + + If you want to compile it as a module, say M here and read + <file:Documentation/kbuild/modules.rst>. If unsure, say `N'. + +config BRIDGE_EBT_MARK + tristate "ebt: mark filter support" + help + This option adds the mark match, which allows matching frames based on + the 'nfmark' value in the frame. This can be set by the mark target. + This value is the same as the one used in the iptables mark match and + target. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_PKTTYPE + tristate "ebt: packet type filter support" + help + This option adds the packet type match, which allows matching on the + type of packet based on its Ethernet "class" (as determined by + the generic networking code): broadcast, multicast, + for this host alone or for another host. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_STP + tristate "ebt: STP filter support" + help + This option adds the Spanning Tree Protocol match, which + allows STP header field filtering. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_VLAN + tristate "ebt: 802.1Q VLAN filter support" + help + This option adds the 802.1Q vlan match, which allows the filtering of + 802.1Q vlan fields. + + To compile it as a module, choose M here. If unsure, say N. +# +# targets +# +config BRIDGE_EBT_ARPREPLY + tristate "ebt: arp reply target support" + depends on BRIDGE_NF_EBTABLES && INET + help + This option adds the arp reply target, which allows + automatically sending arp replies to arp requests. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_DNAT + tristate "ebt: dnat target support" + help + This option adds the MAC DNAT target, which allows altering the MAC + destination address of frames. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_MARK_T + tristate "ebt: mark target support" + help + This option adds the mark target, which allows marking frames by + setting the 'nfmark' value in the frame. + This value is the same as the one used in the iptables mark match and + target. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_REDIRECT + tristate "ebt: redirect target support" + help + This option adds the MAC redirect target, which allows altering the MAC + destination address of a frame to that of the device it arrived on. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_SNAT + tristate "ebt: snat target support" + help + This option adds the MAC SNAT target, which allows altering the MAC + source address of frames. + + To compile it as a module, choose M here. If unsure, say N. +# +# watchers +# +config BRIDGE_EBT_LOG + tristate "ebt: log support" + help + This option adds the log watcher, that you can use in any rule + in any ebtables table. It records info about the frame header + to the syslog. + + To compile it as a module, choose M here. If unsure, say N. + +config BRIDGE_EBT_NFLOG + tristate "ebt: nflog support" + help + This option enables the nflog watcher, which allows to LOG + messages through the netfilter logging API, which can use + either the old LOG target, the old ULOG target or nfnetlink_log + as backend. + + This option adds the nflog watcher, that you can use in any rule + in any ebtables table. + + To compile it as a module, choose M here. If unsure, say N. + +endif # BRIDGE_NF_EBTABLES diff --git a/net/bridge/netfilter/Makefile b/net/bridge/netfilter/Makefile new file mode 100644 index 000000000..1c9ce49ab --- /dev/null +++ b/net/bridge/netfilter/Makefile @@ -0,0 +1,40 @@ +# SPDX-License-Identifier: GPL-2.0 +# +# Makefile for the netfilter modules for Link Layer filtering on a bridge. +# + +obj-$(CONFIG_NFT_BRIDGE_META) += nft_meta_bridge.o +obj-$(CONFIG_NFT_BRIDGE_REJECT) += nft_reject_bridge.o + +# connection tracking +obj-$(CONFIG_NF_CONNTRACK_BRIDGE) += nf_conntrack_bridge.o + +obj-$(CONFIG_BRIDGE_NF_EBTABLES) += ebtables.o + +# tables +obj-$(CONFIG_BRIDGE_EBT_BROUTE) += ebtable_broute.o +obj-$(CONFIG_BRIDGE_EBT_T_FILTER) += ebtable_filter.o +obj-$(CONFIG_BRIDGE_EBT_T_NAT) += ebtable_nat.o + +#matches +obj-$(CONFIG_BRIDGE_EBT_802_3) += ebt_802_3.o +obj-$(CONFIG_BRIDGE_EBT_AMONG) += ebt_among.o +obj-$(CONFIG_BRIDGE_EBT_ARP) += ebt_arp.o +obj-$(CONFIG_BRIDGE_EBT_IP) += ebt_ip.o +obj-$(CONFIG_BRIDGE_EBT_IP6) += ebt_ip6.o +obj-$(CONFIG_BRIDGE_EBT_LIMIT) += ebt_limit.o +obj-$(CONFIG_BRIDGE_EBT_MARK) += ebt_mark_m.o +obj-$(CONFIG_BRIDGE_EBT_PKTTYPE) += ebt_pkttype.o +obj-$(CONFIG_BRIDGE_EBT_STP) += ebt_stp.o +obj-$(CONFIG_BRIDGE_EBT_VLAN) += ebt_vlan.o + +# targets +obj-$(CONFIG_BRIDGE_EBT_ARPREPLY) += ebt_arpreply.o +obj-$(CONFIG_BRIDGE_EBT_MARK_T) += ebt_mark.o +obj-$(CONFIG_BRIDGE_EBT_DNAT) += ebt_dnat.o +obj-$(CONFIG_BRIDGE_EBT_REDIRECT) += ebt_redirect.o +obj-$(CONFIG_BRIDGE_EBT_SNAT) += ebt_snat.o + +# watchers +obj-$(CONFIG_BRIDGE_EBT_LOG) += ebt_log.o +obj-$(CONFIG_BRIDGE_EBT_NFLOG) += ebt_nflog.o diff --git a/net/bridge/netfilter/ebt_802_3.c b/net/bridge/netfilter/ebt_802_3.c new file mode 100644 index 000000000..68c2519bd --- /dev/null +++ b/net/bridge/netfilter/ebt_802_3.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * 802_3 + * + * Author: + * Chris Vitale csv@bluetail.com + * + * May 2003 + * + */ +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/skbuff.h> +#include <uapi/linux/netfilter_bridge/ebt_802_3.h> + +static struct ebt_802_3_hdr *ebt_802_3_hdr(const struct sk_buff *skb) +{ + return (struct ebt_802_3_hdr *)skb_mac_header(skb); +} + +static bool +ebt_802_3_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_802_3_info *info = par->matchinfo; + const struct ebt_802_3_hdr *hdr = ebt_802_3_hdr(skb); + __be16 type = hdr->llc.ui.ctrl & IS_UI ? hdr->llc.ui.type : hdr->llc.ni.type; + + if (info->bitmask & EBT_802_3_SAP) { + if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.ssap)) + return false; + if (NF_INVF(info, EBT_802_3_SAP, info->sap != hdr->llc.ui.dsap)) + return false; + } + + if (info->bitmask & EBT_802_3_TYPE) { + if (!(hdr->llc.ui.dsap == CHECK_TYPE && hdr->llc.ui.ssap == CHECK_TYPE)) + return false; + if (NF_INVF(info, EBT_802_3_TYPE, info->type != type)) + return false; + } + + return true; +} + +static int ebt_802_3_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_802_3_info *info = par->matchinfo; + + if (info->bitmask & ~EBT_802_3_MASK || info->invflags & ~EBT_802_3_MASK) + return -EINVAL; + + return 0; +} + +static struct xt_match ebt_802_3_mt_reg __read_mostly = { + .name = "802_3", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_802_3_mt, + .checkentry = ebt_802_3_mt_check, + .matchsize = sizeof(struct ebt_802_3_info), + .me = THIS_MODULE, +}; + +static int __init ebt_802_3_init(void) +{ + return xt_register_match(&ebt_802_3_mt_reg); +} + +static void __exit ebt_802_3_fini(void) +{ + xt_unregister_match(&ebt_802_3_mt_reg); +} + +module_init(ebt_802_3_init); +module_exit(ebt_802_3_fini); +MODULE_DESCRIPTION("Ebtables: DSAP/SSAP field and SNAP type matching"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_among.c b/net/bridge/netfilter/ebt_among.c new file mode 100644 index 000000000..96f7243b6 --- /dev/null +++ b/net/bridge/netfilter/ebt_among.c @@ -0,0 +1,281 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_among + * + * Authors: + * Grzegorz Borowiak <grzes@gnu.univ.gda.pl> + * + * August, 2003 + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/ip.h> +#include <linux/if_arp.h> +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_among.h> + +static bool ebt_mac_wormhash_contains(const struct ebt_mac_wormhash *wh, + const char *mac, __be32 ip) +{ + /* You may be puzzled as to how this code works. + * Some tricks were used, refer to + * include/linux/netfilter_bridge/ebt_among.h + * as there you can find a solution of this mystery. + */ + const struct ebt_mac_wormhash_tuple *p; + int start, limit, i; + uint32_t cmp[2] = { 0, 0 }; + int key = ((const unsigned char *)mac)[5]; + + ether_addr_copy(((char *) cmp) + 2, mac); + start = wh->table[key]; + limit = wh->table[key + 1]; + if (ip) { + for (i = start; i < limit; i++) { + p = &wh->pool[i]; + if (cmp[1] == p->cmp[1] && cmp[0] == p->cmp[0]) + if (p->ip == 0 || p->ip == ip) + return true; + } + } else { + for (i = start; i < limit; i++) { + p = &wh->pool[i]; + if (cmp[1] == p->cmp[1] && cmp[0] == p->cmp[0]) + if (p->ip == 0) + return true; + } + } + return false; +} + +static int ebt_mac_wormhash_check_integrity(const struct ebt_mac_wormhash + *wh) +{ + int i; + + for (i = 0; i < 256; i++) { + if (wh->table[i] > wh->table[i + 1]) + return -0x100 - i; + if (wh->table[i] < 0) + return -0x200 - i; + if (wh->table[i] > wh->poolsize) + return -0x300 - i; + } + if (wh->table[256] > wh->poolsize) + return -0xc00; + return 0; +} + +static int get_ip_dst(const struct sk_buff *skb, __be32 *addr) +{ + if (eth_hdr(skb)->h_proto == htons(ETH_P_IP)) { + const struct iphdr *ih; + struct iphdr _iph; + + ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (ih == NULL) + return -1; + *addr = ih->daddr; + } else if (eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) { + const struct arphdr *ah; + struct arphdr _arph; + const __be32 *bp; + __be32 buf; + + ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); + if (ah == NULL || + ah->ar_pln != sizeof(__be32) || + ah->ar_hln != ETH_ALEN) + return -1; + bp = skb_header_pointer(skb, sizeof(struct arphdr) + + 2 * ETH_ALEN + sizeof(__be32), + sizeof(__be32), &buf); + if (bp == NULL) + return -1; + *addr = *bp; + } + return 0; +} + +static int get_ip_src(const struct sk_buff *skb, __be32 *addr) +{ + if (eth_hdr(skb)->h_proto == htons(ETH_P_IP)) { + const struct iphdr *ih; + struct iphdr _iph; + + ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (ih == NULL) + return -1; + *addr = ih->saddr; + } else if (eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) { + const struct arphdr *ah; + struct arphdr _arph; + const __be32 *bp; + __be32 buf; + + ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); + if (ah == NULL || + ah->ar_pln != sizeof(__be32) || + ah->ar_hln != ETH_ALEN) + return -1; + bp = skb_header_pointer(skb, sizeof(struct arphdr) + + ETH_ALEN, sizeof(__be32), &buf); + if (bp == NULL) + return -1; + *addr = *bp; + } + return 0; +} + +static bool +ebt_among_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_among_info *info = par->matchinfo; + const char *dmac, *smac; + const struct ebt_mac_wormhash *wh_dst, *wh_src; + __be32 dip = 0, sip = 0; + + wh_dst = ebt_among_wh_dst(info); + wh_src = ebt_among_wh_src(info); + + if (wh_src) { + smac = eth_hdr(skb)->h_source; + if (get_ip_src(skb, &sip)) + return false; + if (!(info->bitmask & EBT_AMONG_SRC_NEG)) { + /* we match only if it contains */ + if (!ebt_mac_wormhash_contains(wh_src, smac, sip)) + return false; + } else { + /* we match only if it DOES NOT contain */ + if (ebt_mac_wormhash_contains(wh_src, smac, sip)) + return false; + } + } + + if (wh_dst) { + dmac = eth_hdr(skb)->h_dest; + if (get_ip_dst(skb, &dip)) + return false; + if (!(info->bitmask & EBT_AMONG_DST_NEG)) { + /* we match only if it contains */ + if (!ebt_mac_wormhash_contains(wh_dst, dmac, dip)) + return false; + } else { + /* we match only if it DOES NOT contain */ + if (ebt_mac_wormhash_contains(wh_dst, dmac, dip)) + return false; + } + } + + return true; +} + +static bool poolsize_invalid(const struct ebt_mac_wormhash *w) +{ + return w && w->poolsize >= (INT_MAX / sizeof(struct ebt_mac_wormhash_tuple)); +} + +static bool wormhash_offset_invalid(int off, unsigned int len) +{ + if (off == 0) /* not present */ + return false; + + if (off < (int)sizeof(struct ebt_among_info) || + off % __alignof__(struct ebt_mac_wormhash)) + return true; + + off += sizeof(struct ebt_mac_wormhash); + + return off > len; +} + +static bool wormhash_sizes_valid(const struct ebt_mac_wormhash *wh, int a, int b) +{ + if (a == 0) + a = sizeof(struct ebt_among_info); + + return ebt_mac_wormhash_size(wh) + a == b; +} + +static int ebt_among_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_among_info *info = par->matchinfo; + const struct ebt_entry_match *em = + container_of(par->matchinfo, const struct ebt_entry_match, data); + unsigned int expected_length = sizeof(struct ebt_among_info); + const struct ebt_mac_wormhash *wh_dst, *wh_src; + int err; + + if (expected_length > em->match_size) + return -EINVAL; + + if (wormhash_offset_invalid(info->wh_dst_ofs, em->match_size) || + wormhash_offset_invalid(info->wh_src_ofs, em->match_size)) + return -EINVAL; + + wh_dst = ebt_among_wh_dst(info); + if (poolsize_invalid(wh_dst)) + return -EINVAL; + + expected_length += ebt_mac_wormhash_size(wh_dst); + if (expected_length > em->match_size) + return -EINVAL; + + wh_src = ebt_among_wh_src(info); + if (poolsize_invalid(wh_src)) + return -EINVAL; + + if (info->wh_src_ofs < info->wh_dst_ofs) { + if (!wormhash_sizes_valid(wh_src, info->wh_src_ofs, info->wh_dst_ofs)) + return -EINVAL; + } else { + if (!wormhash_sizes_valid(wh_dst, info->wh_dst_ofs, info->wh_src_ofs)) + return -EINVAL; + } + + expected_length += ebt_mac_wormhash_size(wh_src); + + if (em->match_size != EBT_ALIGN(expected_length)) { + pr_err_ratelimited("wrong size: %d against expected %d, rounded to %zd\n", + em->match_size, expected_length, + EBT_ALIGN(expected_length)); + return -EINVAL; + } + if (wh_dst && (err = ebt_mac_wormhash_check_integrity(wh_dst))) { + pr_err_ratelimited("dst integrity fail: %x\n", -err); + return -EINVAL; + } + if (wh_src && (err = ebt_mac_wormhash_check_integrity(wh_src))) { + pr_err_ratelimited("src integrity fail: %x\n", -err); + return -EINVAL; + } + return 0; +} + +static struct xt_match ebt_among_mt_reg __read_mostly = { + .name = "among", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_among_mt, + .checkentry = ebt_among_mt_check, + .matchsize = -1, /* special case */ + .me = THIS_MODULE, +}; + +static int __init ebt_among_init(void) +{ + return xt_register_match(&ebt_among_mt_reg); +} + +static void __exit ebt_among_fini(void) +{ + xt_unregister_match(&ebt_among_mt_reg); +} + +module_init(ebt_among_init); +module_exit(ebt_among_fini); +MODULE_DESCRIPTION("Ebtables: Combined MAC/IP address list matching"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_arp.c b/net/bridge/netfilter/ebt_arp.c new file mode 100644 index 000000000..0707cc00f --- /dev/null +++ b/net/bridge/netfilter/ebt_arp.c @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_arp + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * Tim Gardner <timg@tpi.com> + * + * April, 2002 + * + */ +#include <linux/if_arp.h> +#include <linux/if_ether.h> +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_arp.h> + +static bool +ebt_arp_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_arp_info *info = par->matchinfo; + const struct arphdr *ah; + struct arphdr _arph; + + ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); + if (ah == NULL) + return false; + if ((info->bitmask & EBT_ARP_OPCODE) && + NF_INVF(info, EBT_ARP_OPCODE, info->opcode != ah->ar_op)) + return false; + if ((info->bitmask & EBT_ARP_HTYPE) && + NF_INVF(info, EBT_ARP_HTYPE, info->htype != ah->ar_hrd)) + return false; + if ((info->bitmask & EBT_ARP_PTYPE) && + NF_INVF(info, EBT_ARP_PTYPE, info->ptype != ah->ar_pro)) + return false; + + if (info->bitmask & (EBT_ARP_SRC_IP | EBT_ARP_DST_IP | EBT_ARP_GRAT)) { + const __be32 *sap, *dap; + __be32 saddr, daddr; + + if (ah->ar_pln != sizeof(__be32) || ah->ar_pro != htons(ETH_P_IP)) + return false; + sap = skb_header_pointer(skb, sizeof(struct arphdr) + + ah->ar_hln, sizeof(saddr), + &saddr); + if (sap == NULL) + return false; + dap = skb_header_pointer(skb, sizeof(struct arphdr) + + 2*ah->ar_hln+sizeof(saddr), + sizeof(daddr), &daddr); + if (dap == NULL) + return false; + if ((info->bitmask & EBT_ARP_SRC_IP) && + NF_INVF(info, EBT_ARP_SRC_IP, + info->saddr != (*sap & info->smsk))) + return false; + if ((info->bitmask & EBT_ARP_DST_IP) && + NF_INVF(info, EBT_ARP_DST_IP, + info->daddr != (*dap & info->dmsk))) + return false; + if ((info->bitmask & EBT_ARP_GRAT) && + NF_INVF(info, EBT_ARP_GRAT, *dap != *sap)) + return false; + } + + if (info->bitmask & (EBT_ARP_SRC_MAC | EBT_ARP_DST_MAC)) { + const unsigned char *mp; + unsigned char _mac[ETH_ALEN]; + + if (ah->ar_hln != ETH_ALEN || ah->ar_hrd != htons(ARPHRD_ETHER)) + return false; + if (info->bitmask & EBT_ARP_SRC_MAC) { + mp = skb_header_pointer(skb, sizeof(struct arphdr), + sizeof(_mac), &_mac); + if (mp == NULL) + return false; + if (NF_INVF(info, EBT_ARP_SRC_MAC, + !ether_addr_equal_masked(mp, info->smaddr, + info->smmsk))) + return false; + } + + if (info->bitmask & EBT_ARP_DST_MAC) { + mp = skb_header_pointer(skb, sizeof(struct arphdr) + + ah->ar_hln + ah->ar_pln, + sizeof(_mac), &_mac); + if (mp == NULL) + return false; + if (NF_INVF(info, EBT_ARP_DST_MAC, + !ether_addr_equal_masked(mp, info->dmaddr, + info->dmmsk))) + return false; + } + } + + return true; +} + +static int ebt_arp_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_arp_info *info = par->matchinfo; + const struct ebt_entry *e = par->entryinfo; + + if ((e->ethproto != htons(ETH_P_ARP) && + e->ethproto != htons(ETH_P_RARP)) || + e->invflags & EBT_IPROTO) + return -EINVAL; + if (info->bitmask & ~EBT_ARP_MASK || info->invflags & ~EBT_ARP_MASK) + return -EINVAL; + return 0; +} + +static struct xt_match ebt_arp_mt_reg __read_mostly = { + .name = "arp", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_arp_mt, + .checkentry = ebt_arp_mt_check, + .matchsize = sizeof(struct ebt_arp_info), + .me = THIS_MODULE, +}; + +static int __init ebt_arp_init(void) +{ + return xt_register_match(&ebt_arp_mt_reg); +} + +static void __exit ebt_arp_fini(void) +{ + xt_unregister_match(&ebt_arp_mt_reg); +} + +module_init(ebt_arp_init); +module_exit(ebt_arp_fini); +MODULE_DESCRIPTION("Ebtables: ARP protocol packet match"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_arpreply.c b/net/bridge/netfilter/ebt_arpreply.c new file mode 100644 index 000000000..d9e77e250 --- /dev/null +++ b/net/bridge/netfilter/ebt_arpreply.c @@ -0,0 +1,103 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_arpreply + * + * Authors: + * Grzegorz Borowiak <grzes@gnu.univ.gda.pl> + * Bart De Schuymer <bdschuym@pandora.be> + * + * August, 2003 + * + */ +#include <linux/if_arp.h> +#include <net/arp.h> +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_arpreply.h> + +static unsigned int +ebt_arpreply_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_arpreply_info *info = par->targinfo; + const __be32 *siptr, *diptr; + __be32 _sip, _dip; + const struct arphdr *ap; + struct arphdr _ah; + const unsigned char *shp; + unsigned char _sha[ETH_ALEN]; + + ap = skb_header_pointer(skb, 0, sizeof(_ah), &_ah); + if (ap == NULL) + return EBT_DROP; + + if (ap->ar_op != htons(ARPOP_REQUEST) || + ap->ar_hln != ETH_ALEN || + ap->ar_pro != htons(ETH_P_IP) || + ap->ar_pln != 4) + return EBT_CONTINUE; + + shp = skb_header_pointer(skb, sizeof(_ah), ETH_ALEN, &_sha); + if (shp == NULL) + return EBT_DROP; + + siptr = skb_header_pointer(skb, sizeof(_ah) + ETH_ALEN, + sizeof(_sip), &_sip); + if (siptr == NULL) + return EBT_DROP; + + diptr = skb_header_pointer(skb, + sizeof(_ah) + 2 * ETH_ALEN + sizeof(_sip), + sizeof(_dip), &_dip); + if (diptr == NULL) + return EBT_DROP; + + arp_send(ARPOP_REPLY, ETH_P_ARP, *siptr, + (struct net_device *)xt_in(par), + *diptr, shp, info->mac, shp); + + return info->target; +} + +static int ebt_arpreply_tg_check(const struct xt_tgchk_param *par) +{ + const struct ebt_arpreply_info *info = par->targinfo; + const struct ebt_entry *e = par->entryinfo; + + if (BASE_CHAIN && info->target == EBT_RETURN) + return -EINVAL; + if (e->ethproto != htons(ETH_P_ARP) || + e->invflags & EBT_IPROTO) + return -EINVAL; + if (ebt_invalid_target(info->target)) + return -EINVAL; + + return 0; +} + +static struct xt_target ebt_arpreply_tg_reg __read_mostly = { + .name = "arpreply", + .revision = 0, + .family = NFPROTO_BRIDGE, + .table = "nat", + .hooks = (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING), + .target = ebt_arpreply_tg, + .checkentry = ebt_arpreply_tg_check, + .targetsize = sizeof(struct ebt_arpreply_info), + .me = THIS_MODULE, +}; + +static int __init ebt_arpreply_init(void) +{ + return xt_register_target(&ebt_arpreply_tg_reg); +} + +static void __exit ebt_arpreply_fini(void) +{ + xt_unregister_target(&ebt_arpreply_tg_reg); +} + +module_init(ebt_arpreply_init); +module_exit(ebt_arpreply_fini); +MODULE_DESCRIPTION("Ebtables: ARP reply target"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_dnat.c b/net/bridge/netfilter/ebt_dnat.c new file mode 100644 index 000000000..3fda71a85 --- /dev/null +++ b/net/bridge/netfilter/ebt_dnat.c @@ -0,0 +1,106 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_dnat + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * June, 2002 + * + */ +#include <linux/module.h> +#include <net/sock.h> +#include "../br_private.h" +#include <linux/netfilter.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_nat.h> + +static unsigned int +ebt_dnat_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_nat_info *info = par->targinfo; + + if (skb_ensure_writable(skb, 0)) + return EBT_DROP; + + ether_addr_copy(eth_hdr(skb)->h_dest, info->mac); + + if (is_multicast_ether_addr(info->mac)) { + if (is_broadcast_ether_addr(info->mac)) + skb->pkt_type = PACKET_BROADCAST; + else + skb->pkt_type = PACKET_MULTICAST; + } else { + const struct net_device *dev; + + switch (xt_hooknum(par)) { + case NF_BR_BROUTING: + dev = xt_in(par); + break; + case NF_BR_PRE_ROUTING: + dev = br_port_get_rcu(xt_in(par))->br->dev; + break; + default: + dev = NULL; + break; + } + + if (!dev) /* NF_BR_LOCAL_OUT */ + return info->target; + + if (ether_addr_equal(info->mac, dev->dev_addr)) + skb->pkt_type = PACKET_HOST; + else + skb->pkt_type = PACKET_OTHERHOST; + } + + return info->target; +} + +static int ebt_dnat_tg_check(const struct xt_tgchk_param *par) +{ + const struct ebt_nat_info *info = par->targinfo; + unsigned int hook_mask; + + if (BASE_CHAIN && info->target == EBT_RETURN) + return -EINVAL; + + hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS); + if ((strcmp(par->table, "nat") != 0 || + (hook_mask & ~((1 << NF_BR_PRE_ROUTING) | + (1 << NF_BR_LOCAL_OUT)))) && + (strcmp(par->table, "broute") != 0 || + hook_mask & ~(1 << NF_BR_BROUTING))) + return -EINVAL; + if (ebt_invalid_target(info->target)) + return -EINVAL; + return 0; +} + +static struct xt_target ebt_dnat_tg_reg __read_mostly = { + .name = "dnat", + .revision = 0, + .family = NFPROTO_BRIDGE, + .hooks = (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) | + (1 << NF_BR_LOCAL_OUT) | (1 << NF_BR_BROUTING), + .target = ebt_dnat_tg, + .checkentry = ebt_dnat_tg_check, + .targetsize = sizeof(struct ebt_nat_info), + .me = THIS_MODULE, +}; + +static int __init ebt_dnat_init(void) +{ + return xt_register_target(&ebt_dnat_tg_reg); +} + +static void __exit ebt_dnat_fini(void) +{ + xt_unregister_target(&ebt_dnat_tg_reg); +} + +module_init(ebt_dnat_init); +module_exit(ebt_dnat_fini); +MODULE_DESCRIPTION("Ebtables: Destination MAC address translation"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_ip.c b/net/bridge/netfilter/ebt_ip.c new file mode 100644 index 000000000..df372496c --- /dev/null +++ b/net/bridge/netfilter/ebt_ip.c @@ -0,0 +1,169 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_ip + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2002 + * + * Changes: + * added ip-sport and ip-dport + * Innominate Security Technologies AG <mhopf@innominate.com> + * September, 2002 + */ +#include <linux/ip.h> +#include <net/ip.h> +#include <linux/in.h> +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_ip.h> + +union pkthdr { + struct { + __be16 src; + __be16 dst; + } tcpudphdr; + struct { + u8 type; + u8 code; + } icmphdr; + struct { + u8 type; + } igmphdr; +}; + +static bool +ebt_ip_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_ip_info *info = par->matchinfo; + const struct iphdr *ih; + struct iphdr _iph; + const union pkthdr *pptr; + union pkthdr _pkthdr; + + ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (ih == NULL) + return false; + if ((info->bitmask & EBT_IP_TOS) && + NF_INVF(info, EBT_IP_TOS, info->tos != ih->tos)) + return false; + if ((info->bitmask & EBT_IP_SOURCE) && + NF_INVF(info, EBT_IP_SOURCE, + (ih->saddr & info->smsk) != info->saddr)) + return false; + if ((info->bitmask & EBT_IP_DEST) && + NF_INVF(info, EBT_IP_DEST, + (ih->daddr & info->dmsk) != info->daddr)) + return false; + if (info->bitmask & EBT_IP_PROTO) { + if (NF_INVF(info, EBT_IP_PROTO, info->protocol != ih->protocol)) + return false; + if (!(info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT | + EBT_IP_ICMP | EBT_IP_IGMP))) + return true; + if (ntohs(ih->frag_off) & IP_OFFSET) + return false; + + /* min icmp/igmp headersize is 4, so sizeof(_pkthdr) is ok. */ + pptr = skb_header_pointer(skb, ih->ihl*4, + sizeof(_pkthdr), &_pkthdr); + if (pptr == NULL) + return false; + if (info->bitmask & EBT_IP_DPORT) { + u32 dst = ntohs(pptr->tcpudphdr.dst); + if (NF_INVF(info, EBT_IP_DPORT, + dst < info->dport[0] || + dst > info->dport[1])) + return false; + } + if (info->bitmask & EBT_IP_SPORT) { + u32 src = ntohs(pptr->tcpudphdr.src); + if (NF_INVF(info, EBT_IP_SPORT, + src < info->sport[0] || + src > info->sport[1])) + return false; + } + if ((info->bitmask & EBT_IP_ICMP) && + NF_INVF(info, EBT_IP_ICMP, + pptr->icmphdr.type < info->icmp_type[0] || + pptr->icmphdr.type > info->icmp_type[1] || + pptr->icmphdr.code < info->icmp_code[0] || + pptr->icmphdr.code > info->icmp_code[1])) + return false; + if ((info->bitmask & EBT_IP_IGMP) && + NF_INVF(info, EBT_IP_IGMP, + pptr->igmphdr.type < info->igmp_type[0] || + pptr->igmphdr.type > info->igmp_type[1])) + return false; + } + return true; +} + +static int ebt_ip_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_ip_info *info = par->matchinfo; + const struct ebt_entry *e = par->entryinfo; + + if (e->ethproto != htons(ETH_P_IP) || + e->invflags & EBT_IPROTO) + return -EINVAL; + if (info->bitmask & ~EBT_IP_MASK || info->invflags & ~EBT_IP_MASK) + return -EINVAL; + if (info->bitmask & (EBT_IP_DPORT | EBT_IP_SPORT)) { + if (info->invflags & EBT_IP_PROTO) + return -EINVAL; + if (info->protocol != IPPROTO_TCP && + info->protocol != IPPROTO_UDP && + info->protocol != IPPROTO_UDPLITE && + info->protocol != IPPROTO_SCTP && + info->protocol != IPPROTO_DCCP) + return -EINVAL; + } + if (info->bitmask & EBT_IP_DPORT && info->dport[0] > info->dport[1]) + return -EINVAL; + if (info->bitmask & EBT_IP_SPORT && info->sport[0] > info->sport[1]) + return -EINVAL; + if (info->bitmask & EBT_IP_ICMP) { + if ((info->invflags & EBT_IP_PROTO) || + info->protocol != IPPROTO_ICMP) + return -EINVAL; + if (info->icmp_type[0] > info->icmp_type[1] || + info->icmp_code[0] > info->icmp_code[1]) + return -EINVAL; + } + if (info->bitmask & EBT_IP_IGMP) { + if ((info->invflags & EBT_IP_PROTO) || + info->protocol != IPPROTO_IGMP) + return -EINVAL; + if (info->igmp_type[0] > info->igmp_type[1]) + return -EINVAL; + } + return 0; +} + +static struct xt_match ebt_ip_mt_reg __read_mostly = { + .name = "ip", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_ip_mt, + .checkentry = ebt_ip_mt_check, + .matchsize = sizeof(struct ebt_ip_info), + .me = THIS_MODULE, +}; + +static int __init ebt_ip_init(void) +{ + return xt_register_match(&ebt_ip_mt_reg); +} + +static void __exit ebt_ip_fini(void) +{ + xt_unregister_match(&ebt_ip_mt_reg); +} + +module_init(ebt_ip_init); +module_exit(ebt_ip_fini); +MODULE_DESCRIPTION("Ebtables: IPv4 protocol packet match"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_ip6.c b/net/bridge/netfilter/ebt_ip6.c new file mode 100644 index 000000000..f3225bc31 --- /dev/null +++ b/net/bridge/netfilter/ebt_ip6.c @@ -0,0 +1,164 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_ip6 + * + * Authors: + * Manohar Castelino <manohar.r.castelino@intel.com> + * Kuo-Lang Tseng <kuo-lang.tseng@intel.com> + * Jan Engelhardt <jengelh@medozas.de> + * + * Summary: + * This is just a modification of the IPv4 code written by + * Bart De Schuymer <bdschuym@pandora.be> + * with the changes required to support IPv6 + * + * Jan, 2008 + */ +#include <linux/ipv6.h> +#include <net/ipv6.h> +#include <linux/in.h> +#include <linux/module.h> +#include <net/dsfield.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_ip6.h> + +union pkthdr { + struct { + __be16 src; + __be16 dst; + } tcpudphdr; + struct { + u8 type; + u8 code; + } icmphdr; +}; + +static bool +ebt_ip6_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_ip6_info *info = par->matchinfo; + const struct ipv6hdr *ih6; + struct ipv6hdr _ip6h; + const union pkthdr *pptr; + union pkthdr _pkthdr; + + ih6 = skb_header_pointer(skb, 0, sizeof(_ip6h), &_ip6h); + if (ih6 == NULL) + return false; + if ((info->bitmask & EBT_IP6_TCLASS) && + NF_INVF(info, EBT_IP6_TCLASS, + info->tclass != ipv6_get_dsfield(ih6))) + return false; + if (((info->bitmask & EBT_IP6_SOURCE) && + NF_INVF(info, EBT_IP6_SOURCE, + ipv6_masked_addr_cmp(&ih6->saddr, &info->smsk, + &info->saddr))) || + ((info->bitmask & EBT_IP6_DEST) && + NF_INVF(info, EBT_IP6_DEST, + ipv6_masked_addr_cmp(&ih6->daddr, &info->dmsk, + &info->daddr)))) + return false; + if (info->bitmask & EBT_IP6_PROTO) { + uint8_t nexthdr = ih6->nexthdr; + __be16 frag_off; + int offset_ph; + + offset_ph = ipv6_skip_exthdr(skb, sizeof(_ip6h), &nexthdr, &frag_off); + if (offset_ph == -1) + return false; + if (NF_INVF(info, EBT_IP6_PROTO, info->protocol != nexthdr)) + return false; + if (!(info->bitmask & (EBT_IP6_DPORT | + EBT_IP6_SPORT | EBT_IP6_ICMP6))) + return true; + + /* min icmpv6 headersize is 4, so sizeof(_pkthdr) is ok. */ + pptr = skb_header_pointer(skb, offset_ph, sizeof(_pkthdr), + &_pkthdr); + if (pptr == NULL) + return false; + if (info->bitmask & EBT_IP6_DPORT) { + u16 dst = ntohs(pptr->tcpudphdr.dst); + if (NF_INVF(info, EBT_IP6_DPORT, + dst < info->dport[0] || + dst > info->dport[1])) + return false; + } + if (info->bitmask & EBT_IP6_SPORT) { + u16 src = ntohs(pptr->tcpudphdr.src); + if (NF_INVF(info, EBT_IP6_SPORT, + src < info->sport[0] || + src > info->sport[1])) + return false; + } + if ((info->bitmask & EBT_IP6_ICMP6) && + NF_INVF(info, EBT_IP6_ICMP6, + pptr->icmphdr.type < info->icmpv6_type[0] || + pptr->icmphdr.type > info->icmpv6_type[1] || + pptr->icmphdr.code < info->icmpv6_code[0] || + pptr->icmphdr.code > info->icmpv6_code[1])) + return false; + } + return true; +} + +static int ebt_ip6_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_entry *e = par->entryinfo; + struct ebt_ip6_info *info = par->matchinfo; + + if (e->ethproto != htons(ETH_P_IPV6) || e->invflags & EBT_IPROTO) + return -EINVAL; + if (info->bitmask & ~EBT_IP6_MASK || info->invflags & ~EBT_IP6_MASK) + return -EINVAL; + if (info->bitmask & (EBT_IP6_DPORT | EBT_IP6_SPORT)) { + if (info->invflags & EBT_IP6_PROTO) + return -EINVAL; + if (info->protocol != IPPROTO_TCP && + info->protocol != IPPROTO_UDP && + info->protocol != IPPROTO_UDPLITE && + info->protocol != IPPROTO_SCTP && + info->protocol != IPPROTO_DCCP) + return -EINVAL; + } + if (info->bitmask & EBT_IP6_DPORT && info->dport[0] > info->dport[1]) + return -EINVAL; + if (info->bitmask & EBT_IP6_SPORT && info->sport[0] > info->sport[1]) + return -EINVAL; + if (info->bitmask & EBT_IP6_ICMP6) { + if ((info->invflags & EBT_IP6_PROTO) || + info->protocol != IPPROTO_ICMPV6) + return -EINVAL; + if (info->icmpv6_type[0] > info->icmpv6_type[1] || + info->icmpv6_code[0] > info->icmpv6_code[1]) + return -EINVAL; + } + return 0; +} + +static struct xt_match ebt_ip6_mt_reg __read_mostly = { + .name = "ip6", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_ip6_mt, + .checkentry = ebt_ip6_mt_check, + .matchsize = sizeof(struct ebt_ip6_info), + .me = THIS_MODULE, +}; + +static int __init ebt_ip6_init(void) +{ + return xt_register_match(&ebt_ip6_mt_reg); +} + +static void __exit ebt_ip6_fini(void) +{ + xt_unregister_match(&ebt_ip6_mt_reg); +} + +module_init(ebt_ip6_init); +module_exit(ebt_ip6_fini); +MODULE_DESCRIPTION("Ebtables: IPv6 protocol packet match"); +MODULE_AUTHOR("Kuo-Lang Tseng <kuo-lang.tseng@intel.com>"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_limit.c b/net/bridge/netfilter/ebt_limit.c new file mode 100644 index 000000000..e16183bd1 --- /dev/null +++ b/net/bridge/netfilter/ebt_limit.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_limit + * + * Authors: + * Tom Marshall <tommy@home.tig-grr.com> + * + * Mostly copied from netfilter's ipt_limit.c, see that file for + * more explanation + * + * September, 2003 + * + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/spinlock.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_limit.h> + +static DEFINE_SPINLOCK(limit_lock); + +#define MAX_CPJ (0xFFFFFFFF / (HZ*60*60*24)) + +#define _POW2_BELOW2(x) ((x)|((x)>>1)) +#define _POW2_BELOW4(x) (_POW2_BELOW2(x)|_POW2_BELOW2((x)>>2)) +#define _POW2_BELOW8(x) (_POW2_BELOW4(x)|_POW2_BELOW4((x)>>4)) +#define _POW2_BELOW16(x) (_POW2_BELOW8(x)|_POW2_BELOW8((x)>>8)) +#define _POW2_BELOW32(x) (_POW2_BELOW16(x)|_POW2_BELOW16((x)>>16)) +#define POW2_BELOW32(x) ((_POW2_BELOW32(x)>>1) + 1) + +#define CREDITS_PER_JIFFY POW2_BELOW32(MAX_CPJ) + +static bool +ebt_limit_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + struct ebt_limit_info *info = (void *)par->matchinfo; + unsigned long now = jiffies; + + spin_lock_bh(&limit_lock); + info->credit += (now - xchg(&info->prev, now)) * CREDITS_PER_JIFFY; + if (info->credit > info->credit_cap) + info->credit = info->credit_cap; + + if (info->credit >= info->cost) { + /* We're not limited. */ + info->credit -= info->cost; + spin_unlock_bh(&limit_lock); + return true; + } + + spin_unlock_bh(&limit_lock); + return false; +} + +/* Precision saver. */ +static u_int32_t +user2credits(u_int32_t user) +{ + /* If multiplying would overflow... */ + if (user > 0xFFFFFFFF / (HZ*CREDITS_PER_JIFFY)) + /* Divide first. */ + return (user / EBT_LIMIT_SCALE) * HZ * CREDITS_PER_JIFFY; + + return (user * HZ * CREDITS_PER_JIFFY) / EBT_LIMIT_SCALE; +} + +static int ebt_limit_mt_check(const struct xt_mtchk_param *par) +{ + struct ebt_limit_info *info = par->matchinfo; + + /* Check for overflow. */ + if (info->burst == 0 || + user2credits(info->avg * info->burst) < user2credits(info->avg)) { + pr_info_ratelimited("overflow, try lower: %u/%u\n", + info->avg, info->burst); + return -EINVAL; + } + + /* User avg in seconds * EBT_LIMIT_SCALE: convert to jiffies * 128. */ + info->prev = jiffies; + info->credit = user2credits(info->avg * info->burst); + info->credit_cap = user2credits(info->avg * info->burst); + info->cost = user2credits(info->avg); + return 0; +} + + +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT +/* + * no conversion function needed -- + * only avg/burst have meaningful values in userspace. + */ +struct ebt_compat_limit_info { + compat_uint_t avg, burst; + compat_ulong_t prev; + compat_uint_t credit, credit_cap, cost; +}; +#endif + +static struct xt_match ebt_limit_mt_reg __read_mostly = { + .name = "limit", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_limit_mt, + .checkentry = ebt_limit_mt_check, + .matchsize = sizeof(struct ebt_limit_info), + .usersize = offsetof(struct ebt_limit_info, prev), +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + .compatsize = sizeof(struct ebt_compat_limit_info), +#endif + .me = THIS_MODULE, +}; + +static int __init ebt_limit_init(void) +{ + return xt_register_match(&ebt_limit_mt_reg); +} + +static void __exit ebt_limit_fini(void) +{ + xt_unregister_match(&ebt_limit_mt_reg); +} + +module_init(ebt_limit_init); +module_exit(ebt_limit_fini); +MODULE_DESCRIPTION("Ebtables: Rate-limit match"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_log.c b/net/bridge/netfilter/ebt_log.c new file mode 100644 index 000000000..e2eea1daa --- /dev/null +++ b/net/bridge/netfilter/ebt_log.c @@ -0,0 +1,226 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_log + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * Harald Welte <laforge@netfilter.org> + * + * April, 2002 + * + */ +#include <linux/module.h> +#include <linux/ip.h> +#include <linux/in.h> +#include <linux/if_arp.h> +#include <linux/spinlock.h> +#include <net/netfilter/nf_log.h> +#include <linux/ipv6.h> +#include <net/ipv6.h> +#include <linux/in6.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_log.h> +#include <linux/netfilter.h> + +static DEFINE_SPINLOCK(ebt_log_lock); + +static int ebt_log_tg_check(const struct xt_tgchk_param *par) +{ + struct ebt_log_info *info = par->targinfo; + + if (info->bitmask & ~EBT_LOG_MASK) + return -EINVAL; + if (info->loglevel >= 8) + return -EINVAL; + info->prefix[EBT_LOG_PREFIX_SIZE - 1] = '\0'; + return 0; +} + +struct tcpudphdr { + __be16 src; + __be16 dst; +}; + +struct arppayload { + unsigned char mac_src[ETH_ALEN]; + unsigned char ip_src[4]; + unsigned char mac_dst[ETH_ALEN]; + unsigned char ip_dst[4]; +}; + +static void +print_ports(const struct sk_buff *skb, uint8_t protocol, int offset) +{ + if (protocol == IPPROTO_TCP || + protocol == IPPROTO_UDP || + protocol == IPPROTO_UDPLITE || + protocol == IPPROTO_SCTP || + protocol == IPPROTO_DCCP) { + const struct tcpudphdr *pptr; + struct tcpudphdr _ports; + + pptr = skb_header_pointer(skb, offset, + sizeof(_ports), &_ports); + if (pptr == NULL) { + pr_cont(" INCOMPLETE TCP/UDP header"); + return; + } + pr_cont(" SPT=%u DPT=%u", ntohs(pptr->src), ntohs(pptr->dst)); + } +} + +static void +ebt_log_packet(struct net *net, u_int8_t pf, unsigned int hooknum, + const struct sk_buff *skb, const struct net_device *in, + const struct net_device *out, const struct nf_loginfo *loginfo, + const char *prefix) +{ + unsigned int bitmask; + + /* FIXME: Disabled from containers until syslog ns is supported */ + if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) + return; + + spin_lock_bh(&ebt_log_lock); + printk(KERN_SOH "%c%s IN=%s OUT=%s MAC source = %pM MAC dest = %pM proto = 0x%04x", + '0' + loginfo->u.log.level, prefix, + in ? in->name : "", out ? out->name : "", + eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, + ntohs(eth_hdr(skb)->h_proto)); + + if (loginfo->type == NF_LOG_TYPE_LOG) + bitmask = loginfo->u.log.logflags; + else + bitmask = NF_LOG_DEFAULT_MASK; + + if ((bitmask & EBT_LOG_IP) && eth_hdr(skb)->h_proto == + htons(ETH_P_IP)) { + const struct iphdr *ih; + struct iphdr _iph; + + ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (ih == NULL) { + pr_cont(" INCOMPLETE IP header"); + goto out; + } + pr_cont(" IP SRC=%pI4 IP DST=%pI4, IP tos=0x%02X, IP proto=%d", + &ih->saddr, &ih->daddr, ih->tos, ih->protocol); + print_ports(skb, ih->protocol, ih->ihl*4); + goto out; + } + +#if IS_ENABLED(CONFIG_BRIDGE_EBT_IP6) + if ((bitmask & EBT_LOG_IP6) && eth_hdr(skb)->h_proto == + htons(ETH_P_IPV6)) { + const struct ipv6hdr *ih; + struct ipv6hdr _iph; + uint8_t nexthdr; + __be16 frag_off; + int offset_ph; + + ih = skb_header_pointer(skb, 0, sizeof(_iph), &_iph); + if (ih == NULL) { + pr_cont(" INCOMPLETE IPv6 header"); + goto out; + } + pr_cont(" IPv6 SRC=%pI6 IPv6 DST=%pI6, IPv6 priority=0x%01X, Next Header=%d", + &ih->saddr, &ih->daddr, ih->priority, ih->nexthdr); + nexthdr = ih->nexthdr; + offset_ph = ipv6_skip_exthdr(skb, sizeof(_iph), &nexthdr, &frag_off); + if (offset_ph == -1) + goto out; + print_ports(skb, nexthdr, offset_ph); + goto out; + } +#endif + + if ((bitmask & EBT_LOG_ARP) && + ((eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) || + (eth_hdr(skb)->h_proto == htons(ETH_P_RARP)))) { + const struct arphdr *ah; + struct arphdr _arph; + + ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); + if (ah == NULL) { + pr_cont(" INCOMPLETE ARP header"); + goto out; + } + pr_cont(" ARP HTYPE=%d, PTYPE=0x%04x, OPCODE=%d", + ntohs(ah->ar_hrd), ntohs(ah->ar_pro), + ntohs(ah->ar_op)); + + /* If it's for Ethernet and the lengths are OK, + * then log the ARP payload + */ + if (ah->ar_hrd == htons(1) && + ah->ar_hln == ETH_ALEN && + ah->ar_pln == sizeof(__be32)) { + const struct arppayload *ap; + struct arppayload _arpp; + + ap = skb_header_pointer(skb, sizeof(_arph), + sizeof(_arpp), &_arpp); + if (ap == NULL) { + pr_cont(" INCOMPLETE ARP payload"); + goto out; + } + pr_cont(" ARP MAC SRC=%pM ARP IP SRC=%pI4 ARP MAC DST=%pM ARP IP DST=%pI4", + ap->mac_src, ap->ip_src, + ap->mac_dst, ap->ip_dst); + } + } +out: + pr_cont("\n"); + spin_unlock_bh(&ebt_log_lock); +} + +static unsigned int +ebt_log_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_log_info *info = par->targinfo; + struct nf_loginfo li; + struct net *net = xt_net(par); + + li.type = NF_LOG_TYPE_LOG; + li.u.log.level = info->loglevel; + li.u.log.logflags = info->bitmask; + + /* Remember that we have to use ebt_log_packet() not to break backward + * compatibility. We cannot use the default bridge packet logger via + * nf_log_packet() with NFT_LOG_TYPE_LOG here. --Pablo + */ + if (info->bitmask & EBT_LOG_NFLOG) + nf_log_packet(net, NFPROTO_BRIDGE, xt_hooknum(par), skb, + xt_in(par), xt_out(par), &li, "%s", + info->prefix); + else + ebt_log_packet(net, NFPROTO_BRIDGE, xt_hooknum(par), skb, + xt_in(par), xt_out(par), &li, info->prefix); + return EBT_CONTINUE; +} + +static struct xt_target ebt_log_tg_reg __read_mostly = { + .name = "log", + .revision = 0, + .family = NFPROTO_BRIDGE, + .target = ebt_log_tg, + .checkentry = ebt_log_tg_check, + .targetsize = sizeof(struct ebt_log_info), + .me = THIS_MODULE, +}; + +static int __init ebt_log_init(void) +{ + return xt_register_target(&ebt_log_tg_reg); +} + +static void __exit ebt_log_fini(void) +{ + xt_unregister_target(&ebt_log_tg_reg); +} + +module_init(ebt_log_init); +module_exit(ebt_log_fini); +MODULE_DESCRIPTION("Ebtables: Packet logging to syslog"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_mark.c b/net/bridge/netfilter/ebt_mark.c new file mode 100644 index 000000000..8cf653c72 --- /dev/null +++ b/net/bridge/netfilter/ebt_mark.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_mark + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * July, 2002 + * + */ + +/* The mark target can be used in any chain, + * I believe adding a mangle table just for marking is total overkill. + * Marking a frame doesn't really change anything in the frame anyway. + */ + +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_mark_t.h> + +static unsigned int +ebt_mark_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_mark_t_info *info = par->targinfo; + int action = info->target & -16; + + if (action == MARK_SET_VALUE) + skb->mark = info->mark; + else if (action == MARK_OR_VALUE) + skb->mark |= info->mark; + else if (action == MARK_AND_VALUE) + skb->mark &= info->mark; + else + skb->mark ^= info->mark; + + return info->target | ~EBT_VERDICT_BITS; +} + +static int ebt_mark_tg_check(const struct xt_tgchk_param *par) +{ + const struct ebt_mark_t_info *info = par->targinfo; + int tmp; + + tmp = info->target | ~EBT_VERDICT_BITS; + if (BASE_CHAIN && tmp == EBT_RETURN) + return -EINVAL; + if (ebt_invalid_target(tmp)) + return -EINVAL; + tmp = info->target & ~EBT_VERDICT_BITS; + if (tmp != MARK_SET_VALUE && tmp != MARK_OR_VALUE && + tmp != MARK_AND_VALUE && tmp != MARK_XOR_VALUE) + return -EINVAL; + return 0; +} +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT +struct compat_ebt_mark_t_info { + compat_ulong_t mark; + compat_uint_t target; +}; + +static void mark_tg_compat_from_user(void *dst, const void *src) +{ + const struct compat_ebt_mark_t_info *user = src; + struct ebt_mark_t_info *kern = dst; + + kern->mark = user->mark; + kern->target = user->target; +} + +static int mark_tg_compat_to_user(void __user *dst, const void *src) +{ + struct compat_ebt_mark_t_info __user *user = dst; + const struct ebt_mark_t_info *kern = src; + + if (put_user(kern->mark, &user->mark) || + put_user(kern->target, &user->target)) + return -EFAULT; + return 0; +} +#endif + +static struct xt_target ebt_mark_tg_reg __read_mostly = { + .name = "mark", + .revision = 0, + .family = NFPROTO_BRIDGE, + .target = ebt_mark_tg, + .checkentry = ebt_mark_tg_check, + .targetsize = sizeof(struct ebt_mark_t_info), +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + .compatsize = sizeof(struct compat_ebt_mark_t_info), + .compat_from_user = mark_tg_compat_from_user, + .compat_to_user = mark_tg_compat_to_user, +#endif + .me = THIS_MODULE, +}; + +static int __init ebt_mark_init(void) +{ + return xt_register_target(&ebt_mark_tg_reg); +} + +static void __exit ebt_mark_fini(void) +{ + xt_unregister_target(&ebt_mark_tg_reg); +} + +module_init(ebt_mark_init); +module_exit(ebt_mark_fini); +MODULE_DESCRIPTION("Ebtables: Packet mark modification"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_mark_m.c b/net/bridge/netfilter/ebt_mark_m.c new file mode 100644 index 000000000..5872e73c7 --- /dev/null +++ b/net/bridge/netfilter/ebt_mark_m.c @@ -0,0 +1,99 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_mark_m + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * July, 2002 + * + */ +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_mark_m.h> + +static bool +ebt_mark_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_mark_m_info *info = par->matchinfo; + + if (info->bitmask & EBT_MARK_OR) + return !!(skb->mark & info->mask) ^ info->invert; + return ((skb->mark & info->mask) == info->mark) ^ info->invert; +} + +static int ebt_mark_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_mark_m_info *info = par->matchinfo; + + if (info->bitmask & ~EBT_MARK_MASK) + return -EINVAL; + if ((info->bitmask & EBT_MARK_OR) && (info->bitmask & EBT_MARK_AND)) + return -EINVAL; + if (!info->bitmask) + return -EINVAL; + return 0; +} + + +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT +struct compat_ebt_mark_m_info { + compat_ulong_t mark, mask; + uint8_t invert, bitmask; +}; + +static void mark_mt_compat_from_user(void *dst, const void *src) +{ + const struct compat_ebt_mark_m_info *user = src; + struct ebt_mark_m_info *kern = dst; + + kern->mark = user->mark; + kern->mask = user->mask; + kern->invert = user->invert; + kern->bitmask = user->bitmask; +} + +static int mark_mt_compat_to_user(void __user *dst, const void *src) +{ + struct compat_ebt_mark_m_info __user *user = dst; + const struct ebt_mark_m_info *kern = src; + + if (put_user(kern->mark, &user->mark) || + put_user(kern->mask, &user->mask) || + put_user(kern->invert, &user->invert) || + put_user(kern->bitmask, &user->bitmask)) + return -EFAULT; + return 0; +} +#endif + +static struct xt_match ebt_mark_mt_reg __read_mostly = { + .name = "mark_m", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_mark_mt, + .checkentry = ebt_mark_mt_check, + .matchsize = sizeof(struct ebt_mark_m_info), +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + .compatsize = sizeof(struct compat_ebt_mark_m_info), + .compat_from_user = mark_mt_compat_from_user, + .compat_to_user = mark_mt_compat_to_user, +#endif + .me = THIS_MODULE, +}; + +static int __init ebt_mark_m_init(void) +{ + return xt_register_match(&ebt_mark_mt_reg); +} + +static void __exit ebt_mark_m_fini(void) +{ + xt_unregister_match(&ebt_mark_mt_reg); +} + +module_init(ebt_mark_m_init); +module_exit(ebt_mark_m_fini); +MODULE_DESCRIPTION("Ebtables: Packet mark match"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_nflog.c b/net/bridge/netfilter/ebt_nflog.c new file mode 100644 index 000000000..61bf8f446 --- /dev/null +++ b/net/bridge/netfilter/ebt_nflog.c @@ -0,0 +1,75 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_nflog + * + * Author: + * Peter Warasin <peter@endian.com> + * + * February, 2008 + * + * Based on: + * xt_NFLOG.c, (C) 2006 by Patrick McHardy <kaber@trash.net> + * ebt_ulog.c, (C) 2004 by Bart De Schuymer <bdschuym@pandora.be> + * + */ + +#include <linux/module.h> +#include <linux/spinlock.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_nflog.h> +#include <net/netfilter/nf_log.h> + +static unsigned int +ebt_nflog_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_nflog_info *info = par->targinfo; + struct net *net = xt_net(par); + struct nf_loginfo li; + + li.type = NF_LOG_TYPE_ULOG; + li.u.ulog.copy_len = info->len; + li.u.ulog.group = info->group; + li.u.ulog.qthreshold = info->threshold; + li.u.ulog.flags = 0; + + nf_log_packet(net, PF_BRIDGE, xt_hooknum(par), skb, xt_in(par), + xt_out(par), &li, "%s", info->prefix); + return EBT_CONTINUE; +} + +static int ebt_nflog_tg_check(const struct xt_tgchk_param *par) +{ + struct ebt_nflog_info *info = par->targinfo; + + if (info->flags & ~EBT_NFLOG_MASK) + return -EINVAL; + info->prefix[EBT_NFLOG_PREFIX_SIZE - 1] = '\0'; + return 0; +} + +static struct xt_target ebt_nflog_tg_reg __read_mostly = { + .name = "nflog", + .revision = 0, + .family = NFPROTO_BRIDGE, + .target = ebt_nflog_tg, + .checkentry = ebt_nflog_tg_check, + .targetsize = sizeof(struct ebt_nflog_info), + .me = THIS_MODULE, +}; + +static int __init ebt_nflog_init(void) +{ + return xt_register_target(&ebt_nflog_tg_reg); +} + +static void __exit ebt_nflog_fini(void) +{ + xt_unregister_target(&ebt_nflog_tg_reg); +} + +module_init(ebt_nflog_init); +module_exit(ebt_nflog_fini); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Peter Warasin <peter@endian.com>"); +MODULE_DESCRIPTION("ebtables NFLOG netfilter logging module"); diff --git a/net/bridge/netfilter/ebt_pkttype.c b/net/bridge/netfilter/ebt_pkttype.c new file mode 100644 index 000000000..c9e306119 --- /dev/null +++ b/net/bridge/netfilter/ebt_pkttype.c @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_pkttype + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2003 + * + */ +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_pkttype.h> + +static bool +ebt_pkttype_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_pkttype_info *info = par->matchinfo; + + return (skb->pkt_type == info->pkt_type) ^ info->invert; +} + +static int ebt_pkttype_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_pkttype_info *info = par->matchinfo; + + if (info->invert != 0 && info->invert != 1) + return -EINVAL; + /* Allow any pkt_type value */ + return 0; +} + +static struct xt_match ebt_pkttype_mt_reg __read_mostly = { + .name = "pkttype", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_pkttype_mt, + .checkentry = ebt_pkttype_mt_check, + .matchsize = sizeof(struct ebt_pkttype_info), + .me = THIS_MODULE, +}; + +static int __init ebt_pkttype_init(void) +{ + return xt_register_match(&ebt_pkttype_mt_reg); +} + +static void __exit ebt_pkttype_fini(void) +{ + xt_unregister_match(&ebt_pkttype_mt_reg); +} + +module_init(ebt_pkttype_init); +module_exit(ebt_pkttype_fini); +MODULE_DESCRIPTION("Ebtables: Link layer packet type match"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_redirect.c b/net/bridge/netfilter/ebt_redirect.c new file mode 100644 index 000000000..307790562 --- /dev/null +++ b/net/bridge/netfilter/ebt_redirect.c @@ -0,0 +1,81 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_redirect + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2002 + * + */ +#include <linux/module.h> +#include <net/sock.h> +#include "../br_private.h" +#include <linux/netfilter.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_redirect.h> + +static unsigned int +ebt_redirect_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_redirect_info *info = par->targinfo; + + if (skb_ensure_writable(skb, 0)) + return EBT_DROP; + + if (xt_hooknum(par) != NF_BR_BROUTING) + /* rcu_read_lock()ed by nf_hook_thresh */ + ether_addr_copy(eth_hdr(skb)->h_dest, + br_port_get_rcu(xt_in(par))->br->dev->dev_addr); + else + ether_addr_copy(eth_hdr(skb)->h_dest, xt_in(par)->dev_addr); + skb->pkt_type = PACKET_HOST; + return info->target; +} + +static int ebt_redirect_tg_check(const struct xt_tgchk_param *par) +{ + const struct ebt_redirect_info *info = par->targinfo; + unsigned int hook_mask; + + if (BASE_CHAIN && info->target == EBT_RETURN) + return -EINVAL; + + hook_mask = par->hook_mask & ~(1 << NF_BR_NUMHOOKS); + if ((strcmp(par->table, "nat") != 0 || + hook_mask & ~(1 << NF_BR_PRE_ROUTING)) && + (strcmp(par->table, "broute") != 0 || + hook_mask & ~(1 << NF_BR_BROUTING))) + return -EINVAL; + if (ebt_invalid_target(info->target)) + return -EINVAL; + return 0; +} + +static struct xt_target ebt_redirect_tg_reg __read_mostly = { + .name = "redirect", + .revision = 0, + .family = NFPROTO_BRIDGE, + .hooks = (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_PRE_ROUTING) | + (1 << NF_BR_BROUTING), + .target = ebt_redirect_tg, + .checkentry = ebt_redirect_tg_check, + .targetsize = sizeof(struct ebt_redirect_info), + .me = THIS_MODULE, +}; + +static int __init ebt_redirect_init(void) +{ + return xt_register_target(&ebt_redirect_tg_reg); +} + +static void __exit ebt_redirect_fini(void) +{ + xt_unregister_target(&ebt_redirect_tg_reg); +} + +module_init(ebt_redirect_init); +module_exit(ebt_redirect_fini); +MODULE_DESCRIPTION("Ebtables: Packet redirection to localhost"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_snat.c b/net/bridge/netfilter/ebt_snat.c new file mode 100644 index 000000000..7dfbcdfc3 --- /dev/null +++ b/net/bridge/netfilter/ebt_snat.c @@ -0,0 +1,88 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_snat + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * June, 2002 + * + */ +#include <linux/module.h> +#include <net/sock.h> +#include <linux/if_arp.h> +#include <net/arp.h> +#include <linux/netfilter.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_nat.h> + +static unsigned int +ebt_snat_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct ebt_nat_info *info = par->targinfo; + + if (skb_ensure_writable(skb, 0)) + return EBT_DROP; + + ether_addr_copy(eth_hdr(skb)->h_source, info->mac); + if (!(info->target & NAT_ARP_BIT) && + eth_hdr(skb)->h_proto == htons(ETH_P_ARP)) { + const struct arphdr *ap; + struct arphdr _ah; + + ap = skb_header_pointer(skb, 0, sizeof(_ah), &_ah); + if (ap == NULL) + return EBT_DROP; + if (ap->ar_hln != ETH_ALEN) + goto out; + if (skb_store_bits(skb, sizeof(_ah), info->mac, ETH_ALEN)) + return EBT_DROP; + } +out: + return info->target | ~EBT_VERDICT_BITS; +} + +static int ebt_snat_tg_check(const struct xt_tgchk_param *par) +{ + const struct ebt_nat_info *info = par->targinfo; + int tmp; + + tmp = info->target | ~EBT_VERDICT_BITS; + if (BASE_CHAIN && tmp == EBT_RETURN) + return -EINVAL; + + if (ebt_invalid_target(tmp)) + return -EINVAL; + tmp = info->target | EBT_VERDICT_BITS; + if ((tmp & ~NAT_ARP_BIT) != ~NAT_ARP_BIT) + return -EINVAL; + return 0; +} + +static struct xt_target ebt_snat_tg_reg __read_mostly = { + .name = "snat", + .revision = 0, + .family = NFPROTO_BRIDGE, + .table = "nat", + .hooks = (1 << NF_BR_NUMHOOKS) | (1 << NF_BR_POST_ROUTING), + .target = ebt_snat_tg, + .checkentry = ebt_snat_tg_check, + .targetsize = sizeof(struct ebt_nat_info), + .me = THIS_MODULE, +}; + +static int __init ebt_snat_init(void) +{ + return xt_register_target(&ebt_snat_tg_reg); +} + +static void __exit ebt_snat_fini(void) +{ + xt_unregister_target(&ebt_snat_tg_reg); +} + +module_init(ebt_snat_init); +module_exit(ebt_snat_fini); +MODULE_DESCRIPTION("Ebtables: Source MAC address translation"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_stp.c b/net/bridge/netfilter/ebt_stp.c new file mode 100644 index 000000000..8f68afda5 --- /dev/null +++ b/net/bridge/netfilter/ebt_stp.c @@ -0,0 +1,194 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebt_stp + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * Stephen Hemminger <shemminger@osdl.org> + * + * July, 2003 + */ +#include <linux/etherdevice.h> +#include <linux/module.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_stp.h> + +#define BPDU_TYPE_CONFIG 0 + +struct stp_header { + u8 dsap; + u8 ssap; + u8 ctrl; + u8 pid; + u8 vers; + u8 type; +}; + +struct stp_config_pdu { + u8 flags; + u8 root[8]; + u8 root_cost[4]; + u8 sender[8]; + u8 port[2]; + u8 msg_age[2]; + u8 max_age[2]; + u8 hello_time[2]; + u8 forward_delay[2]; +}; + +#define NR16(p) (p[0] << 8 | p[1]) +#define NR32(p) ((p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3]) + +static bool ebt_filter_config(const struct ebt_stp_info *info, + const struct stp_config_pdu *stpc) +{ + const struct ebt_stp_config_info *c; + u16 v16; + u32 v32; + + c = &info->config; + if ((info->bitmask & EBT_STP_FLAGS) && + NF_INVF(info, EBT_STP_FLAGS, c->flags != stpc->flags)) + return false; + if (info->bitmask & EBT_STP_ROOTPRIO) { + v16 = NR16(stpc->root); + if (NF_INVF(info, EBT_STP_ROOTPRIO, + v16 < c->root_priol || v16 > c->root_priou)) + return false; + } + if (info->bitmask & EBT_STP_ROOTADDR) { + if (NF_INVF(info, EBT_STP_ROOTADDR, + !ether_addr_equal_masked(&stpc->root[2], + c->root_addr, + c->root_addrmsk))) + return false; + } + if (info->bitmask & EBT_STP_ROOTCOST) { + v32 = NR32(stpc->root_cost); + if (NF_INVF(info, EBT_STP_ROOTCOST, + v32 < c->root_costl || v32 > c->root_costu)) + return false; + } + if (info->bitmask & EBT_STP_SENDERPRIO) { + v16 = NR16(stpc->sender); + if (NF_INVF(info, EBT_STP_SENDERPRIO, + v16 < c->sender_priol || v16 > c->sender_priou)) + return false; + } + if (info->bitmask & EBT_STP_SENDERADDR) { + if (NF_INVF(info, EBT_STP_SENDERADDR, + !ether_addr_equal_masked(&stpc->sender[2], + c->sender_addr, + c->sender_addrmsk))) + return false; + } + if (info->bitmask & EBT_STP_PORT) { + v16 = NR16(stpc->port); + if (NF_INVF(info, EBT_STP_PORT, + v16 < c->portl || v16 > c->portu)) + return false; + } + if (info->bitmask & EBT_STP_MSGAGE) { + v16 = NR16(stpc->msg_age); + if (NF_INVF(info, EBT_STP_MSGAGE, + v16 < c->msg_agel || v16 > c->msg_ageu)) + return false; + } + if (info->bitmask & EBT_STP_MAXAGE) { + v16 = NR16(stpc->max_age); + if (NF_INVF(info, EBT_STP_MAXAGE, + v16 < c->max_agel || v16 > c->max_ageu)) + return false; + } + if (info->bitmask & EBT_STP_HELLOTIME) { + v16 = NR16(stpc->hello_time); + if (NF_INVF(info, EBT_STP_HELLOTIME, + v16 < c->hello_timel || v16 > c->hello_timeu)) + return false; + } + if (info->bitmask & EBT_STP_FWDD) { + v16 = NR16(stpc->forward_delay); + if (NF_INVF(info, EBT_STP_FWDD, + v16 < c->forward_delayl || v16 > c->forward_delayu)) + return false; + } + return true; +} + +static bool +ebt_stp_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_stp_info *info = par->matchinfo; + const struct stp_header *sp; + struct stp_header _stph; + const u8 header[6] = {0x42, 0x42, 0x03, 0x00, 0x00, 0x00}; + + sp = skb_header_pointer(skb, 0, sizeof(_stph), &_stph); + if (sp == NULL) + return false; + + /* The stp code only considers these */ + if (memcmp(sp, header, sizeof(header))) + return false; + + if ((info->bitmask & EBT_STP_TYPE) && + NF_INVF(info, EBT_STP_TYPE, info->type != sp->type)) + return false; + + if (sp->type == BPDU_TYPE_CONFIG && + info->bitmask & EBT_STP_CONFIG_MASK) { + const struct stp_config_pdu *st; + struct stp_config_pdu _stpc; + + st = skb_header_pointer(skb, sizeof(_stph), + sizeof(_stpc), &_stpc); + if (st == NULL) + return false; + return ebt_filter_config(info, st); + } + return true; +} + +static int ebt_stp_mt_check(const struct xt_mtchk_param *par) +{ + const struct ebt_stp_info *info = par->matchinfo; + const struct ebt_entry *e = par->entryinfo; + + if (info->bitmask & ~EBT_STP_MASK || info->invflags & ~EBT_STP_MASK || + !(info->bitmask & EBT_STP_MASK)) + return -EINVAL; + /* Make sure the match only receives stp frames */ + if (!par->nft_compat && + (!ether_addr_equal(e->destmac, eth_stp_addr) || + !(e->bitmask & EBT_DESTMAC) || + !is_broadcast_ether_addr(e->destmsk))) + return -EINVAL; + + return 0; +} + +static struct xt_match ebt_stp_mt_reg __read_mostly = { + .name = "stp", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_stp_mt, + .checkentry = ebt_stp_mt_check, + .matchsize = sizeof(struct ebt_stp_info), + .me = THIS_MODULE, +}; + +static int __init ebt_stp_init(void) +{ + return xt_register_match(&ebt_stp_mt_reg); +} + +static void __exit ebt_stp_fini(void) +{ + xt_unregister_match(&ebt_stp_mt_reg); +} + +module_init(ebt_stp_init); +module_exit(ebt_stp_fini); +MODULE_DESCRIPTION("Ebtables: Spanning Tree Protocol packet match"); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebt_vlan.c b/net/bridge/netfilter/ebt_vlan.c new file mode 100644 index 000000000..80ede370a --- /dev/null +++ b/net/bridge/netfilter/ebt_vlan.c @@ -0,0 +1,173 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Description: EBTables 802.1Q match extension kernelspace module. + * Authors: Nick Fedchik <nick@fedchik.org.ua> + * Bart De Schuymer <bdschuym@pandora.be> + */ + +#include <linux/if_ether.h> +#include <linux/if_vlan.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/netfilter_bridge/ebt_vlan.h> + +#define MODULE_VERS "0.6" + +MODULE_AUTHOR("Nick Fedchik <nick@fedchik.org.ua>"); +MODULE_DESCRIPTION("Ebtables: 802.1Q VLAN tag match"); +MODULE_LICENSE("GPL"); + +#define GET_BITMASK(_BIT_MASK_) info->bitmask & _BIT_MASK_ +#define EXIT_ON_MISMATCH(_MATCH_,_MASK_) {if (!((info->_MATCH_ == _MATCH_)^!!(info->invflags & _MASK_))) return false; } + +static bool +ebt_vlan_mt(const struct sk_buff *skb, struct xt_action_param *par) +{ + const struct ebt_vlan_info *info = par->matchinfo; + + unsigned short TCI; /* Whole TCI, given from parsed frame */ + unsigned short id; /* VLAN ID, given from frame TCI */ + unsigned char prio; /* user_priority, given from frame TCI */ + /* VLAN encapsulated Type/Length field, given from orig frame */ + __be16 encap; + + if (skb_vlan_tag_present(skb)) { + TCI = skb_vlan_tag_get(skb); + encap = skb->protocol; + } else { + const struct vlan_hdr *fp; + struct vlan_hdr _frame; + + fp = skb_header_pointer(skb, 0, sizeof(_frame), &_frame); + if (fp == NULL) + return false; + + TCI = ntohs(fp->h_vlan_TCI); + encap = fp->h_vlan_encapsulated_proto; + } + + /* Tag Control Information (TCI) consists of the following elements: + * - User_priority. The user_priority field is three bits in length, + * interpreted as a binary number. + * - Canonical Format Indicator (CFI). The Canonical Format Indicator + * (CFI) is a single bit flag value. Currently ignored. + * - VLAN Identifier (VID). The VID is encoded as + * an unsigned binary number. + */ + id = TCI & VLAN_VID_MASK; + prio = (TCI >> 13) & 0x7; + + /* Checking VLAN Identifier (VID) */ + if (GET_BITMASK(EBT_VLAN_ID)) + EXIT_ON_MISMATCH(id, EBT_VLAN_ID); + + /* Checking user_priority */ + if (GET_BITMASK(EBT_VLAN_PRIO)) + EXIT_ON_MISMATCH(prio, EBT_VLAN_PRIO); + + /* Checking Encapsulated Proto (Length/Type) field */ + if (GET_BITMASK(EBT_VLAN_ENCAP)) + EXIT_ON_MISMATCH(encap, EBT_VLAN_ENCAP); + + return true; +} + +static int ebt_vlan_mt_check(const struct xt_mtchk_param *par) +{ + struct ebt_vlan_info *info = par->matchinfo; + const struct ebt_entry *e = par->entryinfo; + + /* Is it 802.1Q frame checked? */ + if (e->ethproto != htons(ETH_P_8021Q)) { + pr_debug("passed entry proto %2.4X is not 802.1Q (8100)\n", + ntohs(e->ethproto)); + return -EINVAL; + } + + /* Check for bitmask range + * True if even one bit is out of mask + */ + if (info->bitmask & ~EBT_VLAN_MASK) { + pr_debug("bitmask %2X is out of mask (%2X)\n", + info->bitmask, EBT_VLAN_MASK); + return -EINVAL; + } + + /* Check for inversion flags range */ + if (info->invflags & ~EBT_VLAN_MASK) { + pr_debug("inversion flags %2X is out of mask (%2X)\n", + info->invflags, EBT_VLAN_MASK); + return -EINVAL; + } + + /* Reserved VLAN ID (VID) values + * ----------------------------- + * 0 - The null VLAN ID. + * 1 - The default Port VID (PVID) + * 0x0FFF - Reserved for implementation use. + * if_vlan.h: VLAN_N_VID 4096. + */ + if (GET_BITMASK(EBT_VLAN_ID)) { + if (!!info->id) { /* if id!=0 => check vid range */ + if (info->id > VLAN_N_VID) { + pr_debug("id %d is out of range (1-4096)\n", + info->id); + return -EINVAL; + } + /* Note: This is valid VLAN-tagged frame point. + * Any value of user_priority are acceptable, + * but should be ignored according to 802.1Q Std. + * So we just drop the prio flag. + */ + info->bitmask &= ~EBT_VLAN_PRIO; + } + /* Else, id=0 (null VLAN ID) => user_priority range (any?) */ + } + + if (GET_BITMASK(EBT_VLAN_PRIO)) { + if ((unsigned char) info->prio > 7) { + pr_debug("prio %d is out of range (0-7)\n", + info->prio); + return -EINVAL; + } + } + /* Check for encapsulated proto range - it is possible to be + * any value for u_short range. + * if_ether.h: ETH_ZLEN 60 - Min. octets in frame sans FCS + */ + if (GET_BITMASK(EBT_VLAN_ENCAP)) { + if ((unsigned short) ntohs(info->encap) < ETH_ZLEN) { + pr_debug("encap frame length %d is less than " + "minimal\n", ntohs(info->encap)); + return -EINVAL; + } + } + + return 0; +} + +static struct xt_match ebt_vlan_mt_reg __read_mostly = { + .name = "vlan", + .revision = 0, + .family = NFPROTO_BRIDGE, + .match = ebt_vlan_mt, + .checkentry = ebt_vlan_mt_check, + .matchsize = sizeof(struct ebt_vlan_info), + .me = THIS_MODULE, +}; + +static int __init ebt_vlan_init(void) +{ + pr_debug("ebtables 802.1Q extension module v" MODULE_VERS "\n"); + return xt_register_match(&ebt_vlan_mt_reg); +} + +static void __exit ebt_vlan_fini(void) +{ + xt_unregister_match(&ebt_vlan_mt_reg); +} + +module_init(ebt_vlan_init); +module_exit(ebt_vlan_fini); diff --git a/net/bridge/netfilter/ebtable_broute.c b/net/bridge/netfilter/ebtable_broute.c new file mode 100644 index 000000000..8f1925302 --- /dev/null +++ b/net/bridge/netfilter/ebtable_broute.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebtable_broute + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2002 + * + * This table lets you choose between routing and bridging for frames + * entering on a bridge enslaved nic. This table is traversed before any + * other ebtables table. See net/bridge/br_input.c. + */ + +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/module.h> +#include <linux/if_bridge.h> + +#include "../br_private.h" + +/* EBT_ACCEPT means the frame will be bridged + * EBT_DROP means the frame will be routed + */ +static struct ebt_entries initial_chain = { + .name = "BROUTING", + .policy = EBT_ACCEPT, +}; + +static struct ebt_replace_kernel initial_table = { + .name = "broute", + .valid_hooks = 1 << NF_BR_BROUTING, + .entries_size = sizeof(struct ebt_entries), + .hook_entry = { + [NF_BR_BROUTING] = &initial_chain, + }, + .entries = (char *)&initial_chain, +}; + +static const struct ebt_table broute_table = { + .name = "broute", + .table = &initial_table, + .valid_hooks = 1 << NF_BR_BROUTING, + .me = THIS_MODULE, +}; + +static unsigned int ebt_broute(void *priv, struct sk_buff *skb, + const struct nf_hook_state *s) +{ + struct net_bridge_port *p = br_port_get_rcu(skb->dev); + struct nf_hook_state state; + unsigned char *dest; + int ret; + + if (!p || p->state != BR_STATE_FORWARDING) + return NF_ACCEPT; + + nf_hook_state_init(&state, NF_BR_BROUTING, + NFPROTO_BRIDGE, s->in, NULL, NULL, + s->net, NULL); + + ret = ebt_do_table(priv, skb, &state); + if (ret != NF_DROP) + return ret; + + /* DROP in ebtables -t broute means that the + * skb should be routed, not bridged. + * This is awkward, but can't be changed for compatibility + * reasons. + * + * We map DROP to ACCEPT and set the ->br_netfilter_broute flag. + */ + BR_INPUT_SKB_CB(skb)->br_netfilter_broute = 1; + + /* undo PACKET_HOST mangling done in br_input in case the dst + * address matches the logical bridge but not the port. + */ + dest = eth_hdr(skb)->h_dest; + if (skb->pkt_type == PACKET_HOST && + !ether_addr_equal(skb->dev->dev_addr, dest) && + ether_addr_equal(p->br->dev->dev_addr, dest)) + skb->pkt_type = PACKET_OTHERHOST; + + return NF_ACCEPT; +} + +static const struct nf_hook_ops ebt_ops_broute = { + .hook = ebt_broute, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_PRE_ROUTING, + .priority = NF_BR_PRI_FIRST, +}; + +static int broute_table_init(struct net *net) +{ + return ebt_register_table(net, &broute_table, &ebt_ops_broute); +} + +static void __net_exit broute_net_pre_exit(struct net *net) +{ + ebt_unregister_table_pre_exit(net, "broute"); +} + +static void __net_exit broute_net_exit(struct net *net) +{ + ebt_unregister_table(net, "broute"); +} + +static struct pernet_operations broute_net_ops = { + .exit = broute_net_exit, + .pre_exit = broute_net_pre_exit, +}; + +static int __init ebtable_broute_init(void) +{ + int ret = ebt_register_template(&broute_table, broute_table_init); + + if (ret) + return ret; + + ret = register_pernet_subsys(&broute_net_ops); + if (ret) { + ebt_unregister_template(&broute_table); + return ret; + } + + return 0; +} + +static void __exit ebtable_broute_fini(void) +{ + unregister_pernet_subsys(&broute_net_ops); + ebt_unregister_template(&broute_table); +} + +module_init(ebtable_broute_init); +module_exit(ebtable_broute_fini); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebtable_filter.c b/net/bridge/netfilter/ebtable_filter.c new file mode 100644 index 000000000..278f324e6 --- /dev/null +++ b/net/bridge/netfilter/ebtable_filter.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebtable_filter + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2002 + * + */ + +#include <linux/netfilter_bridge/ebtables.h> +#include <uapi/linux/netfilter_bridge.h> +#include <linux/module.h> + +#define FILTER_VALID_HOOKS ((1 << NF_BR_LOCAL_IN) | (1 << NF_BR_FORWARD) | \ + (1 << NF_BR_LOCAL_OUT)) + +static struct ebt_entries initial_chains[] = { + { + .name = "INPUT", + .policy = EBT_ACCEPT, + }, + { + .name = "FORWARD", + .policy = EBT_ACCEPT, + }, + { + .name = "OUTPUT", + .policy = EBT_ACCEPT, + }, +}; + +static struct ebt_replace_kernel initial_table = { + .name = "filter", + .valid_hooks = FILTER_VALID_HOOKS, + .entries_size = 3 * sizeof(struct ebt_entries), + .hook_entry = { + [NF_BR_LOCAL_IN] = &initial_chains[0], + [NF_BR_FORWARD] = &initial_chains[1], + [NF_BR_LOCAL_OUT] = &initial_chains[2], + }, + .entries = (char *)initial_chains, +}; + +static const struct ebt_table frame_filter = { + .name = "filter", + .table = &initial_table, + .valid_hooks = FILTER_VALID_HOOKS, + .me = THIS_MODULE, +}; + +static const struct nf_hook_ops ebt_ops_filter[] = { + { + .hook = ebt_do_table, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_LOCAL_IN, + .priority = NF_BR_PRI_FILTER_BRIDGED, + }, + { + .hook = ebt_do_table, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_FORWARD, + .priority = NF_BR_PRI_FILTER_BRIDGED, + }, + { + .hook = ebt_do_table, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_LOCAL_OUT, + .priority = NF_BR_PRI_FILTER_OTHER, + }, +}; + +static int frame_filter_table_init(struct net *net) +{ + return ebt_register_table(net, &frame_filter, ebt_ops_filter); +} + +static void __net_exit frame_filter_net_pre_exit(struct net *net) +{ + ebt_unregister_table_pre_exit(net, "filter"); +} + +static void __net_exit frame_filter_net_exit(struct net *net) +{ + ebt_unregister_table(net, "filter"); +} + +static struct pernet_operations frame_filter_net_ops = { + .exit = frame_filter_net_exit, + .pre_exit = frame_filter_net_pre_exit, +}; + +static int __init ebtable_filter_init(void) +{ + int ret = ebt_register_template(&frame_filter, frame_filter_table_init); + + if (ret) + return ret; + + ret = register_pernet_subsys(&frame_filter_net_ops); + if (ret) { + ebt_unregister_template(&frame_filter); + return ret; + } + + return 0; +} + +static void __exit ebtable_filter_fini(void) +{ + unregister_pernet_subsys(&frame_filter_net_ops); + ebt_unregister_template(&frame_filter); +} + +module_init(ebtable_filter_init); +module_exit(ebtable_filter_fini); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebtable_nat.c b/net/bridge/netfilter/ebtable_nat.c new file mode 100644 index 000000000..9066f7f37 --- /dev/null +++ b/net/bridge/netfilter/ebtable_nat.c @@ -0,0 +1,118 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ebtable_nat + * + * Authors: + * Bart De Schuymer <bdschuym@pandora.be> + * + * April, 2002 + * + */ + +#include <linux/netfilter_bridge/ebtables.h> +#include <uapi/linux/netfilter_bridge.h> +#include <linux/module.h> + +#define NAT_VALID_HOOKS ((1 << NF_BR_PRE_ROUTING) | (1 << NF_BR_LOCAL_OUT) | \ + (1 << NF_BR_POST_ROUTING)) + +static struct ebt_entries initial_chains[] = { + { + .name = "PREROUTING", + .policy = EBT_ACCEPT, + }, + { + .name = "OUTPUT", + .policy = EBT_ACCEPT, + }, + { + .name = "POSTROUTING", + .policy = EBT_ACCEPT, + } +}; + +static struct ebt_replace_kernel initial_table = { + .name = "nat", + .valid_hooks = NAT_VALID_HOOKS, + .entries_size = 3 * sizeof(struct ebt_entries), + .hook_entry = { + [NF_BR_PRE_ROUTING] = &initial_chains[0], + [NF_BR_LOCAL_OUT] = &initial_chains[1], + [NF_BR_POST_ROUTING] = &initial_chains[2], + }, + .entries = (char *)initial_chains, +}; + +static const struct ebt_table frame_nat = { + .name = "nat", + .table = &initial_table, + .valid_hooks = NAT_VALID_HOOKS, + .me = THIS_MODULE, +}; + +static const struct nf_hook_ops ebt_ops_nat[] = { + { + .hook = ebt_do_table, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_LOCAL_OUT, + .priority = NF_BR_PRI_NAT_DST_OTHER, + }, + { + .hook = ebt_do_table, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_POST_ROUTING, + .priority = NF_BR_PRI_NAT_SRC, + }, + { + .hook = ebt_do_table, + .pf = NFPROTO_BRIDGE, + .hooknum = NF_BR_PRE_ROUTING, + .priority = NF_BR_PRI_NAT_DST_BRIDGED, + }, +}; + +static int frame_nat_table_init(struct net *net) +{ + return ebt_register_table(net, &frame_nat, ebt_ops_nat); +} + +static void __net_exit frame_nat_net_pre_exit(struct net *net) +{ + ebt_unregister_table_pre_exit(net, "nat"); +} + +static void __net_exit frame_nat_net_exit(struct net *net) +{ + ebt_unregister_table(net, "nat"); +} + +static struct pernet_operations frame_nat_net_ops = { + .exit = frame_nat_net_exit, + .pre_exit = frame_nat_net_pre_exit, +}; + +static int __init ebtable_nat_init(void) +{ + int ret = ebt_register_template(&frame_nat, frame_nat_table_init); + + if (ret) + return ret; + + ret = register_pernet_subsys(&frame_nat_net_ops); + if (ret) { + ebt_unregister_template(&frame_nat); + return ret; + } + + return ret; +} + +static void __exit ebtable_nat_fini(void) +{ + unregister_pernet_subsys(&frame_nat_net_ops); + ebt_unregister_template(&frame_nat); +} + +module_init(ebtable_nat_init); +module_exit(ebtable_nat_fini); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c new file mode 100644 index 000000000..aa23479b2 --- /dev/null +++ b/net/bridge/netfilter/ebtables.c @@ -0,0 +1,2597 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * ebtables + * + * Author: + * Bart De Schuymer <bdschuym@pandora.be> + * + * ebtables.c,v 2.0, July, 2002 + * + * This code is strongly inspired by the iptables code which is + * Copyright (C) 1999 Paul `Rusty' Russell & Michael J. Neuling + */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include <linux/kmod.h> +#include <linux/module.h> +#include <linux/vmalloc.h> +#include <linux/netfilter/x_tables.h> +#include <linux/netfilter_bridge/ebtables.h> +#include <linux/spinlock.h> +#include <linux/mutex.h> +#include <linux/slab.h> +#include <linux/uaccess.h> +#include <linux/smp.h> +#include <linux/cpumask.h> +#include <linux/audit.h> +#include <net/sock.h> +#include <net/netns/generic.h> +/* needed for logical [in,out]-dev filtering */ +#include "../br_private.h" + +/* Each cpu has its own set of counters, so there is no need for write_lock in + * the softirq + * For reading or updating the counters, the user context needs to + * get a write_lock + */ + +/* The size of each set of counters is altered to get cache alignment */ +#define SMP_ALIGN(x) (((x) + SMP_CACHE_BYTES-1) & ~(SMP_CACHE_BYTES-1)) +#define COUNTER_OFFSET(n) (SMP_ALIGN(n * sizeof(struct ebt_counter))) +#define COUNTER_BASE(c, n, cpu) ((struct ebt_counter *)(((char *)c) + \ + COUNTER_OFFSET(n) * cpu)) + +struct ebt_pernet { + struct list_head tables; +}; + +struct ebt_template { + struct list_head list; + char name[EBT_TABLE_MAXNAMELEN]; + struct module *owner; + /* called when table is needed in the given netns */ + int (*table_init)(struct net *net); +}; + +static unsigned int ebt_pernet_id __read_mostly; +static LIST_HEAD(template_tables); +static DEFINE_MUTEX(ebt_mutex); + +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT +static void ebt_standard_compat_from_user(void *dst, const void *src) +{ + int v = *(compat_int_t *)src; + + if (v >= 0) + v += xt_compat_calc_jump(NFPROTO_BRIDGE, v); + memcpy(dst, &v, sizeof(v)); +} + +static int ebt_standard_compat_to_user(void __user *dst, const void *src) +{ + compat_int_t cv = *(int *)src; + + if (cv >= 0) + cv -= xt_compat_calc_jump(NFPROTO_BRIDGE, cv); + return copy_to_user(dst, &cv, sizeof(cv)) ? -EFAULT : 0; +} +#endif + + +static struct xt_target ebt_standard_target = { + .name = "standard", + .revision = 0, + .family = NFPROTO_BRIDGE, + .targetsize = sizeof(int), +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + .compatsize = sizeof(compat_int_t), + .compat_from_user = ebt_standard_compat_from_user, + .compat_to_user = ebt_standard_compat_to_user, +#endif +}; + +static inline int +ebt_do_watcher(const struct ebt_entry_watcher *w, struct sk_buff *skb, + struct xt_action_param *par) +{ + par->target = w->u.watcher; + par->targinfo = w->data; + w->u.watcher->target(skb, par); + /* watchers don't give a verdict */ + return 0; +} + +static inline int +ebt_do_match(struct ebt_entry_match *m, const struct sk_buff *skb, + struct xt_action_param *par) +{ + par->match = m->u.match; + par->matchinfo = m->data; + return !m->u.match->match(skb, par); +} + +static inline int +ebt_dev_check(const char *entry, const struct net_device *device) +{ + int i = 0; + const char *devname; + + if (*entry == '\0') + return 0; + if (!device) + return 1; + devname = device->name; + /* 1 is the wildcard token */ + while (entry[i] != '\0' && entry[i] != 1 && entry[i] == devname[i]) + i++; + return devname[i] != entry[i] && entry[i] != 1; +} + +/* process standard matches */ +static inline int +ebt_basic_match(const struct ebt_entry *e, const struct sk_buff *skb, + const struct net_device *in, const struct net_device *out) +{ + const struct ethhdr *h = eth_hdr(skb); + const struct net_bridge_port *p; + __be16 ethproto; + + if (skb_vlan_tag_present(skb)) + ethproto = htons(ETH_P_8021Q); + else + ethproto = h->h_proto; + + if (e->bitmask & EBT_802_3) { + if (NF_INVF(e, EBT_IPROTO, eth_proto_is_802_3(ethproto))) + return 1; + } else if (!(e->bitmask & EBT_NOPROTO) && + NF_INVF(e, EBT_IPROTO, e->ethproto != ethproto)) + return 1; + + if (NF_INVF(e, EBT_IIN, ebt_dev_check(e->in, in))) + return 1; + if (NF_INVF(e, EBT_IOUT, ebt_dev_check(e->out, out))) + return 1; + /* rcu_read_lock()ed by nf_hook_thresh */ + if (in && (p = br_port_get_rcu(in)) != NULL && + NF_INVF(e, EBT_ILOGICALIN, + ebt_dev_check(e->logical_in, p->br->dev))) + return 1; + if (out && (p = br_port_get_rcu(out)) != NULL && + NF_INVF(e, EBT_ILOGICALOUT, + ebt_dev_check(e->logical_out, p->br->dev))) + return 1; + + if (e->bitmask & EBT_SOURCEMAC) { + if (NF_INVF(e, EBT_ISOURCE, + !ether_addr_equal_masked(h->h_source, e->sourcemac, + e->sourcemsk))) + return 1; + } + if (e->bitmask & EBT_DESTMAC) { + if (NF_INVF(e, EBT_IDEST, + !ether_addr_equal_masked(h->h_dest, e->destmac, + e->destmsk))) + return 1; + } + return 0; +} + +static inline +struct ebt_entry *ebt_next_entry(const struct ebt_entry *entry) +{ + return (void *)entry + entry->next_offset; +} + +static inline const struct ebt_entry_target * +ebt_get_target_c(const struct ebt_entry *e) +{ + return ebt_get_target((struct ebt_entry *)e); +} + +/* Do some firewalling */ +unsigned int ebt_do_table(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + struct ebt_table *table = priv; + unsigned int hook = state->hook; + int i, nentries; + struct ebt_entry *point; + struct ebt_counter *counter_base, *cb_base; + const struct ebt_entry_target *t; + int verdict, sp = 0; + struct ebt_chainstack *cs; + struct ebt_entries *chaininfo; + const char *base; + const struct ebt_table_info *private; + struct xt_action_param acpar; + + acpar.state = state; + acpar.hotdrop = false; + + read_lock_bh(&table->lock); + private = table->private; + cb_base = COUNTER_BASE(private->counters, private->nentries, + smp_processor_id()); + if (private->chainstack) + cs = private->chainstack[smp_processor_id()]; + else + cs = NULL; + chaininfo = private->hook_entry[hook]; + nentries = private->hook_entry[hook]->nentries; + point = (struct ebt_entry *)(private->hook_entry[hook]->data); + counter_base = cb_base + private->hook_entry[hook]->counter_offset; + /* base for chain jumps */ + base = private->entries; + i = 0; + while (i < nentries) { + if (ebt_basic_match(point, skb, state->in, state->out)) + goto letscontinue; + + if (EBT_MATCH_ITERATE(point, ebt_do_match, skb, &acpar) != 0) + goto letscontinue; + if (acpar.hotdrop) { + read_unlock_bh(&table->lock); + return NF_DROP; + } + + ADD_COUNTER(*(counter_base + i), skb->len, 1); + + /* these should only watch: not modify, nor tell us + * what to do with the packet + */ + EBT_WATCHER_ITERATE(point, ebt_do_watcher, skb, &acpar); + + t = ebt_get_target_c(point); + /* standard target */ + if (!t->u.target->target) + verdict = ((struct ebt_standard_target *)t)->verdict; + else { + acpar.target = t->u.target; + acpar.targinfo = t->data; + verdict = t->u.target->target(skb, &acpar); + } + if (verdict == EBT_ACCEPT) { + read_unlock_bh(&table->lock); + return NF_ACCEPT; + } + if (verdict == EBT_DROP) { + read_unlock_bh(&table->lock); + return NF_DROP; + } + if (verdict == EBT_RETURN) { +letsreturn: + if (WARN(sp == 0, "RETURN on base chain")) { + /* act like this is EBT_CONTINUE */ + goto letscontinue; + } + + sp--; + /* put all the local variables right */ + i = cs[sp].n; + chaininfo = cs[sp].chaininfo; + nentries = chaininfo->nentries; + point = cs[sp].e; + counter_base = cb_base + + chaininfo->counter_offset; + continue; + } + if (verdict == EBT_CONTINUE) + goto letscontinue; + + if (WARN(verdict < 0, "bogus standard verdict\n")) { + read_unlock_bh(&table->lock); + return NF_DROP; + } + + /* jump to a udc */ + cs[sp].n = i + 1; + cs[sp].chaininfo = chaininfo; + cs[sp].e = ebt_next_entry(point); + i = 0; + chaininfo = (struct ebt_entries *) (base + verdict); + + if (WARN(chaininfo->distinguisher, "jump to non-chain\n")) { + read_unlock_bh(&table->lock); + return NF_DROP; + } + + nentries = chaininfo->nentries; + point = (struct ebt_entry *)chaininfo->data; + counter_base = cb_base + chaininfo->counter_offset; + sp++; + continue; +letscontinue: + point = ebt_next_entry(point); + i++; + } + + /* I actually like this :) */ + if (chaininfo->policy == EBT_RETURN) + goto letsreturn; + if (chaininfo->policy == EBT_ACCEPT) { + read_unlock_bh(&table->lock); + return NF_ACCEPT; + } + read_unlock_bh(&table->lock); + return NF_DROP; +} + +/* If it succeeds, returns element and locks mutex */ +static inline void * +find_inlist_lock_noload(struct net *net, const char *name, int *error, + struct mutex *mutex) +{ + struct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id); + struct ebt_template *tmpl; + struct ebt_table *table; + + mutex_lock(mutex); + list_for_each_entry(table, &ebt_net->tables, list) { + if (strcmp(table->name, name) == 0) + return table; + } + + list_for_each_entry(tmpl, &template_tables, list) { + if (strcmp(name, tmpl->name) == 0) { + struct module *owner = tmpl->owner; + + if (!try_module_get(owner)) + goto out; + + mutex_unlock(mutex); + + *error = tmpl->table_init(net); + if (*error) { + module_put(owner); + return NULL; + } + + mutex_lock(mutex); + module_put(owner); + break; + } + } + + list_for_each_entry(table, &ebt_net->tables, list) { + if (strcmp(table->name, name) == 0) + return table; + } + +out: + *error = -ENOENT; + mutex_unlock(mutex); + return NULL; +} + +static void * +find_inlist_lock(struct net *net, const char *name, const char *prefix, + int *error, struct mutex *mutex) +{ + return try_then_request_module( + find_inlist_lock_noload(net, name, error, mutex), + "%s%s", prefix, name); +} + +static inline struct ebt_table * +find_table_lock(struct net *net, const char *name, int *error, + struct mutex *mutex) +{ + return find_inlist_lock(net, name, "ebtable_", error, mutex); +} + +static inline void ebt_free_table_info(struct ebt_table_info *info) +{ + int i; + + if (info->chainstack) { + for_each_possible_cpu(i) + vfree(info->chainstack[i]); + vfree(info->chainstack); + } +} +static inline int +ebt_check_match(struct ebt_entry_match *m, struct xt_mtchk_param *par, + unsigned int *cnt) +{ + const struct ebt_entry *e = par->entryinfo; + struct xt_match *match; + size_t left = ((char *)e + e->watchers_offset) - (char *)m; + int ret; + + if (left < sizeof(struct ebt_entry_match) || + left - sizeof(struct ebt_entry_match) < m->match_size) + return -EINVAL; + + match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision); + if (IS_ERR(match) || match->family != NFPROTO_BRIDGE) { + if (!IS_ERR(match)) + module_put(match->me); + request_module("ebt_%s", m->u.name); + match = xt_find_match(NFPROTO_BRIDGE, m->u.name, m->u.revision); + } + if (IS_ERR(match)) + return PTR_ERR(match); + m->u.match = match; + + par->match = match; + par->matchinfo = m->data; + ret = xt_check_match(par, m->match_size, + ntohs(e->ethproto), e->invflags & EBT_IPROTO); + if (ret < 0) { + module_put(match->me); + return ret; + } + + (*cnt)++; + return 0; +} + +static inline int +ebt_check_watcher(struct ebt_entry_watcher *w, struct xt_tgchk_param *par, + unsigned int *cnt) +{ + const struct ebt_entry *e = par->entryinfo; + struct xt_target *watcher; + size_t left = ((char *)e + e->target_offset) - (char *)w; + int ret; + + if (left < sizeof(struct ebt_entry_watcher) || + left - sizeof(struct ebt_entry_watcher) < w->watcher_size) + return -EINVAL; + + watcher = xt_request_find_target(NFPROTO_BRIDGE, w->u.name, 0); + if (IS_ERR(watcher)) + return PTR_ERR(watcher); + + if (watcher->family != NFPROTO_BRIDGE) { + module_put(watcher->me); + return -ENOENT; + } + + w->u.watcher = watcher; + + par->target = watcher; + par->targinfo = w->data; + ret = xt_check_target(par, w->watcher_size, + ntohs(e->ethproto), e->invflags & EBT_IPROTO); + if (ret < 0) { + module_put(watcher->me); + return ret; + } + + (*cnt)++; + return 0; +} + +static int ebt_verify_pointers(const struct ebt_replace *repl, + struct ebt_table_info *newinfo) +{ + unsigned int limit = repl->entries_size; + unsigned int valid_hooks = repl->valid_hooks; + unsigned int offset = 0; + int i; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) + newinfo->hook_entry[i] = NULL; + + newinfo->entries_size = repl->entries_size; + newinfo->nentries = repl->nentries; + + while (offset < limit) { + size_t left = limit - offset; + struct ebt_entry *e = (void *)newinfo->entries + offset; + + if (left < sizeof(unsigned int)) + break; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + if ((valid_hooks & (1 << i)) == 0) + continue; + if ((char __user *)repl->hook_entry[i] == + repl->entries + offset) + break; + } + + if (i != NF_BR_NUMHOOKS || !(e->bitmask & EBT_ENTRY_OR_ENTRIES)) { + if (e->bitmask != 0) { + /* we make userspace set this right, + * so there is no misunderstanding + */ + return -EINVAL; + } + if (i != NF_BR_NUMHOOKS) + newinfo->hook_entry[i] = (struct ebt_entries *)e; + if (left < sizeof(struct ebt_entries)) + break; + offset += sizeof(struct ebt_entries); + } else { + if (left < sizeof(struct ebt_entry)) + break; + if (left < e->next_offset) + break; + if (e->next_offset < sizeof(struct ebt_entry)) + return -EINVAL; + offset += e->next_offset; + } + } + if (offset != limit) + return -EINVAL; + + /* check if all valid hooks have a chain */ + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + if (!newinfo->hook_entry[i] && + (valid_hooks & (1 << i))) + return -EINVAL; + } + return 0; +} + +/* this one is very careful, as it is the first function + * to parse the userspace data + */ +static inline int +ebt_check_entry_size_and_hooks(const struct ebt_entry *e, + const struct ebt_table_info *newinfo, + unsigned int *n, unsigned int *cnt, + unsigned int *totalcnt, unsigned int *udc_cnt) +{ + int i; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + if ((void *)e == (void *)newinfo->hook_entry[i]) + break; + } + /* beginning of a new chain + * if i == NF_BR_NUMHOOKS it must be a user defined chain + */ + if (i != NF_BR_NUMHOOKS || !e->bitmask) { + /* this checks if the previous chain has as many entries + * as it said it has + */ + if (*n != *cnt) + return -EINVAL; + + if (((struct ebt_entries *)e)->policy != EBT_DROP && + ((struct ebt_entries *)e)->policy != EBT_ACCEPT) { + /* only RETURN from udc */ + if (i != NF_BR_NUMHOOKS || + ((struct ebt_entries *)e)->policy != EBT_RETURN) + return -EINVAL; + } + if (i == NF_BR_NUMHOOKS) /* it's a user defined chain */ + (*udc_cnt)++; + if (((struct ebt_entries *)e)->counter_offset != *totalcnt) + return -EINVAL; + *n = ((struct ebt_entries *)e)->nentries; + *cnt = 0; + return 0; + } + /* a plain old entry, heh */ + if (sizeof(struct ebt_entry) > e->watchers_offset || + e->watchers_offset > e->target_offset || + e->target_offset >= e->next_offset) + return -EINVAL; + + /* this is not checked anywhere else */ + if (e->next_offset - e->target_offset < sizeof(struct ebt_entry_target)) + return -EINVAL; + + (*cnt)++; + (*totalcnt)++; + return 0; +} + +struct ebt_cl_stack { + struct ebt_chainstack cs; + int from; + unsigned int hookmask; +}; + +/* We need these positions to check that the jumps to a different part of the + * entries is a jump to the beginning of a new chain. + */ +static inline int +ebt_get_udc_positions(struct ebt_entry *e, struct ebt_table_info *newinfo, + unsigned int *n, struct ebt_cl_stack *udc) +{ + int i; + + /* we're only interested in chain starts */ + if (e->bitmask) + return 0; + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + if (newinfo->hook_entry[i] == (struct ebt_entries *)e) + break; + } + /* only care about udc */ + if (i != NF_BR_NUMHOOKS) + return 0; + + udc[*n].cs.chaininfo = (struct ebt_entries *)e; + /* these initialisations are depended on later in check_chainloops() */ + udc[*n].cs.n = 0; + udc[*n].hookmask = 0; + + (*n)++; + return 0; +} + +static inline int +ebt_cleanup_match(struct ebt_entry_match *m, struct net *net, unsigned int *i) +{ + struct xt_mtdtor_param par; + + if (i && (*i)-- == 0) + return 1; + + par.net = net; + par.match = m->u.match; + par.matchinfo = m->data; + par.family = NFPROTO_BRIDGE; + if (par.match->destroy != NULL) + par.match->destroy(&par); + module_put(par.match->me); + return 0; +} + +static inline int +ebt_cleanup_watcher(struct ebt_entry_watcher *w, struct net *net, unsigned int *i) +{ + struct xt_tgdtor_param par; + + if (i && (*i)-- == 0) + return 1; + + par.net = net; + par.target = w->u.watcher; + par.targinfo = w->data; + par.family = NFPROTO_BRIDGE; + if (par.target->destroy != NULL) + par.target->destroy(&par); + module_put(par.target->me); + return 0; +} + +static inline int +ebt_cleanup_entry(struct ebt_entry *e, struct net *net, unsigned int *cnt) +{ + struct xt_tgdtor_param par; + struct ebt_entry_target *t; + + if (e->bitmask == 0) + return 0; + /* we're done */ + if (cnt && (*cnt)-- == 0) + return 1; + EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, NULL); + EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, NULL); + t = ebt_get_target(e); + + par.net = net; + par.target = t->u.target; + par.targinfo = t->data; + par.family = NFPROTO_BRIDGE; + if (par.target->destroy != NULL) + par.target->destroy(&par); + module_put(par.target->me); + return 0; +} + +static inline int +ebt_check_entry(struct ebt_entry *e, struct net *net, + const struct ebt_table_info *newinfo, + const char *name, unsigned int *cnt, + struct ebt_cl_stack *cl_s, unsigned int udc_cnt) +{ + struct ebt_entry_target *t; + struct xt_target *target; + unsigned int i, j, hook = 0, hookmask = 0; + size_t gap; + int ret; + struct xt_mtchk_param mtpar; + struct xt_tgchk_param tgpar; + + /* don't mess with the struct ebt_entries */ + if (e->bitmask == 0) + return 0; + + if (e->bitmask & ~EBT_F_MASK) + return -EINVAL; + + if (e->invflags & ~EBT_INV_MASK) + return -EINVAL; + + if ((e->bitmask & EBT_NOPROTO) && (e->bitmask & EBT_802_3)) + return -EINVAL; + + /* what hook do we belong to? */ + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + if (!newinfo->hook_entry[i]) + continue; + if ((char *)newinfo->hook_entry[i] < (char *)e) + hook = i; + else + break; + } + /* (1 << NF_BR_NUMHOOKS) tells the check functions the rule is on + * a base chain + */ + if (i < NF_BR_NUMHOOKS) + hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); + else { + for (i = 0; i < udc_cnt; i++) + if ((char *)(cl_s[i].cs.chaininfo) > (char *)e) + break; + if (i == 0) + hookmask = (1 << hook) | (1 << NF_BR_NUMHOOKS); + else + hookmask = cl_s[i - 1].hookmask; + } + i = 0; + + memset(&mtpar, 0, sizeof(mtpar)); + memset(&tgpar, 0, sizeof(tgpar)); + mtpar.net = tgpar.net = net; + mtpar.table = tgpar.table = name; + mtpar.entryinfo = tgpar.entryinfo = e; + mtpar.hook_mask = tgpar.hook_mask = hookmask; + mtpar.family = tgpar.family = NFPROTO_BRIDGE; + ret = EBT_MATCH_ITERATE(e, ebt_check_match, &mtpar, &i); + if (ret != 0) + goto cleanup_matches; + j = 0; + ret = EBT_WATCHER_ITERATE(e, ebt_check_watcher, &tgpar, &j); + if (ret != 0) + goto cleanup_watchers; + t = ebt_get_target(e); + gap = e->next_offset - e->target_offset; + + target = xt_request_find_target(NFPROTO_BRIDGE, t->u.name, 0); + if (IS_ERR(target)) { + ret = PTR_ERR(target); + goto cleanup_watchers; + } + + /* Reject UNSPEC, xtables verdicts/return values are incompatible */ + if (target->family != NFPROTO_BRIDGE) { + module_put(target->me); + ret = -ENOENT; + goto cleanup_watchers; + } + + t->u.target = target; + if (t->u.target == &ebt_standard_target) { + if (gap < sizeof(struct ebt_standard_target)) { + ret = -EFAULT; + goto cleanup_watchers; + } + if (((struct ebt_standard_target *)t)->verdict < + -NUM_STANDARD_TARGETS) { + ret = -EFAULT; + goto cleanup_watchers; + } + } else if (t->target_size > gap - sizeof(struct ebt_entry_target)) { + module_put(t->u.target->me); + ret = -EFAULT; + goto cleanup_watchers; + } + + tgpar.target = target; + tgpar.targinfo = t->data; + ret = xt_check_target(&tgpar, t->target_size, + ntohs(e->ethproto), e->invflags & EBT_IPROTO); + if (ret < 0) { + module_put(target->me); + goto cleanup_watchers; + } + (*cnt)++; + return 0; +cleanup_watchers: + EBT_WATCHER_ITERATE(e, ebt_cleanup_watcher, net, &j); +cleanup_matches: + EBT_MATCH_ITERATE(e, ebt_cleanup_match, net, &i); + return ret; +} + +/* checks for loops and sets the hook mask for udc + * the hook mask for udc tells us from which base chains the udc can be + * accessed. This mask is a parameter to the check() functions of the extensions + */ +static int check_chainloops(const struct ebt_entries *chain, struct ebt_cl_stack *cl_s, + unsigned int udc_cnt, unsigned int hooknr, char *base) +{ + int i, chain_nr = -1, pos = 0, nentries = chain->nentries, verdict; + const struct ebt_entry *e = (struct ebt_entry *)chain->data; + const struct ebt_entry_target *t; + + while (pos < nentries || chain_nr != -1) { + /* end of udc, go back one 'recursion' step */ + if (pos == nentries) { + /* put back values of the time when this chain was called */ + e = cl_s[chain_nr].cs.e; + if (cl_s[chain_nr].from != -1) + nentries = + cl_s[cl_s[chain_nr].from].cs.chaininfo->nentries; + else + nentries = chain->nentries; + pos = cl_s[chain_nr].cs.n; + /* make sure we won't see a loop that isn't one */ + cl_s[chain_nr].cs.n = 0; + chain_nr = cl_s[chain_nr].from; + if (pos == nentries) + continue; + } + t = ebt_get_target_c(e); + if (strcmp(t->u.name, EBT_STANDARD_TARGET)) + goto letscontinue; + if (e->target_offset + sizeof(struct ebt_standard_target) > + e->next_offset) + return -1; + + verdict = ((struct ebt_standard_target *)t)->verdict; + if (verdict >= 0) { /* jump to another chain */ + struct ebt_entries *hlp2 = + (struct ebt_entries *)(base + verdict); + for (i = 0; i < udc_cnt; i++) + if (hlp2 == cl_s[i].cs.chaininfo) + break; + /* bad destination or loop */ + if (i == udc_cnt) + return -1; + + if (cl_s[i].cs.n) + return -1; + + if (cl_s[i].hookmask & (1 << hooknr)) + goto letscontinue; + /* this can't be 0, so the loop test is correct */ + cl_s[i].cs.n = pos + 1; + pos = 0; + cl_s[i].cs.e = ebt_next_entry(e); + e = (struct ebt_entry *)(hlp2->data); + nentries = hlp2->nentries; + cl_s[i].from = chain_nr; + chain_nr = i; + /* this udc is accessible from the base chain for hooknr */ + cl_s[i].hookmask |= (1 << hooknr); + continue; + } +letscontinue: + e = ebt_next_entry(e); + pos++; + } + return 0; +} + +/* do the parsing of the table/chains/entries/matches/watchers/targets, heh */ +static int translate_table(struct net *net, const char *name, + struct ebt_table_info *newinfo) +{ + unsigned int i, j, k, udc_cnt; + int ret; + struct ebt_cl_stack *cl_s = NULL; /* used in the checking for chain loops */ + + i = 0; + while (i < NF_BR_NUMHOOKS && !newinfo->hook_entry[i]) + i++; + if (i == NF_BR_NUMHOOKS) + return -EINVAL; + + if (newinfo->hook_entry[i] != (struct ebt_entries *)newinfo->entries) + return -EINVAL; + + /* make sure chains are ordered after each other in same order + * as their corresponding hooks + */ + for (j = i + 1; j < NF_BR_NUMHOOKS; j++) { + if (!newinfo->hook_entry[j]) + continue; + if (newinfo->hook_entry[j] <= newinfo->hook_entry[i]) + return -EINVAL; + + i = j; + } + + /* do some early checkings and initialize some things */ + i = 0; /* holds the expected nr. of entries for the chain */ + j = 0; /* holds the up to now counted entries for the chain */ + k = 0; /* holds the total nr. of entries, should equal + * newinfo->nentries afterwards + */ + udc_cnt = 0; /* will hold the nr. of user defined chains (udc) */ + ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, + ebt_check_entry_size_and_hooks, newinfo, + &i, &j, &k, &udc_cnt); + + if (ret != 0) + return ret; + + if (i != j) + return -EINVAL; + + if (k != newinfo->nentries) + return -EINVAL; + + /* get the location of the udc, put them in an array + * while we're at it, allocate the chainstack + */ + if (udc_cnt) { + /* this will get free'd in do_replace()/ebt_register_table() + * if an error occurs + */ + newinfo->chainstack = + vmalloc(array_size(nr_cpu_ids, + sizeof(*(newinfo->chainstack)))); + if (!newinfo->chainstack) + return -ENOMEM; + for_each_possible_cpu(i) { + newinfo->chainstack[i] = + vmalloc_node(array_size(udc_cnt, + sizeof(*(newinfo->chainstack[0]))), + cpu_to_node(i)); + if (!newinfo->chainstack[i]) { + while (i) + vfree(newinfo->chainstack[--i]); + vfree(newinfo->chainstack); + newinfo->chainstack = NULL; + return -ENOMEM; + } + } + + cl_s = vmalloc(array_size(udc_cnt, sizeof(*cl_s))); + if (!cl_s) + return -ENOMEM; + i = 0; /* the i'th udc */ + EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, + ebt_get_udc_positions, newinfo, &i, cl_s); + /* sanity check */ + if (i != udc_cnt) { + vfree(cl_s); + return -EFAULT; + } + } + + /* Check for loops */ + for (i = 0; i < NF_BR_NUMHOOKS; i++) + if (newinfo->hook_entry[i]) + if (check_chainloops(newinfo->hook_entry[i], + cl_s, udc_cnt, i, newinfo->entries)) { + vfree(cl_s); + return -EINVAL; + } + + /* we now know the following (along with E=mc²): + * - the nr of entries in each chain is right + * - the size of the allocated space is right + * - all valid hooks have a corresponding chain + * - there are no loops + * - wrong data can still be on the level of a single entry + * - could be there are jumps to places that are not the + * beginning of a chain. This can only occur in chains that + * are not accessible from any base chains, so we don't care. + */ + + /* used to know what we need to clean up if something goes wrong */ + i = 0; + ret = EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, + ebt_check_entry, net, newinfo, name, &i, cl_s, udc_cnt); + if (ret != 0) { + EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, + ebt_cleanup_entry, net, &i); + } + vfree(cl_s); + return ret; +} + +/* called under write_lock */ +static void get_counters(const struct ebt_counter *oldcounters, + struct ebt_counter *counters, unsigned int nentries) +{ + int i, cpu; + struct ebt_counter *counter_base; + + /* counters of cpu 0 */ + memcpy(counters, oldcounters, + sizeof(struct ebt_counter) * nentries); + + /* add other counters to those of cpu 0 */ + for_each_possible_cpu(cpu) { + if (cpu == 0) + continue; + counter_base = COUNTER_BASE(oldcounters, nentries, cpu); + for (i = 0; i < nentries; i++) + ADD_COUNTER(counters[i], counter_base[i].bcnt, + counter_base[i].pcnt); + } +} + +static int do_replace_finish(struct net *net, struct ebt_replace *repl, + struct ebt_table_info *newinfo) +{ + int ret; + struct ebt_counter *counterstmp = NULL; + /* used to be able to unlock earlier */ + struct ebt_table_info *table; + struct ebt_table *t; + + /* the user wants counters back + * the check on the size is done later, when we have the lock + */ + if (repl->num_counters) { + unsigned long size = repl->num_counters * sizeof(*counterstmp); + counterstmp = vmalloc(size); + if (!counterstmp) + return -ENOMEM; + } + + newinfo->chainstack = NULL; + ret = ebt_verify_pointers(repl, newinfo); + if (ret != 0) + goto free_counterstmp; + + ret = translate_table(net, repl->name, newinfo); + + if (ret != 0) + goto free_counterstmp; + + t = find_table_lock(net, repl->name, &ret, &ebt_mutex); + if (!t) { + ret = -ENOENT; + goto free_iterate; + } + + if (repl->valid_hooks != t->valid_hooks) { + ret = -EINVAL; + goto free_unlock; + } + + if (repl->num_counters && repl->num_counters != t->private->nentries) { + ret = -EINVAL; + goto free_unlock; + } + + /* we have the mutex lock, so no danger in reading this pointer */ + table = t->private; + /* make sure the table can only be rmmod'ed if it contains no rules */ + if (!table->nentries && newinfo->nentries && !try_module_get(t->me)) { + ret = -ENOENT; + goto free_unlock; + } else if (table->nentries && !newinfo->nentries) + module_put(t->me); + /* we need an atomic snapshot of the counters */ + write_lock_bh(&t->lock); + if (repl->num_counters) + get_counters(t->private->counters, counterstmp, + t->private->nentries); + + t->private = newinfo; + write_unlock_bh(&t->lock); + mutex_unlock(&ebt_mutex); + /* so, a user can change the chains while having messed up her counter + * allocation. Only reason why this is done is because this way the lock + * is held only once, while this doesn't bring the kernel into a + * dangerous state. + */ + if (repl->num_counters && + copy_to_user(repl->counters, counterstmp, + array_size(repl->num_counters, sizeof(struct ebt_counter)))) { + /* Silent error, can't fail, new table is already in place */ + net_warn_ratelimited("ebtables: counters copy to user failed while replacing table\n"); + } + + /* decrease module count and free resources */ + EBT_ENTRY_ITERATE(table->entries, table->entries_size, + ebt_cleanup_entry, net, NULL); + + vfree(table->entries); + ebt_free_table_info(table); + vfree(table); + vfree(counterstmp); + + audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries, + AUDIT_XT_OP_REPLACE, GFP_KERNEL); + return 0; + +free_unlock: + mutex_unlock(&ebt_mutex); +free_iterate: + EBT_ENTRY_ITERATE(newinfo->entries, newinfo->entries_size, + ebt_cleanup_entry, net, NULL); +free_counterstmp: + vfree(counterstmp); + /* can be initialized in translate_table() */ + ebt_free_table_info(newinfo); + return ret; +} + +/* replace the table */ +static int do_replace(struct net *net, sockptr_t arg, unsigned int len) +{ + int ret, countersize; + struct ebt_table_info *newinfo; + struct ebt_replace tmp; + + if (copy_from_sockptr(&tmp, arg, sizeof(tmp)) != 0) + return -EFAULT; + + if (len != sizeof(tmp) + tmp.entries_size) + return -EINVAL; + + if (tmp.entries_size == 0) + return -EINVAL; + + /* overflow check */ + if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / + NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) + return -ENOMEM; + if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) + return -ENOMEM; + + tmp.name[sizeof(tmp.name) - 1] = 0; + + countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; + newinfo = __vmalloc(sizeof(*newinfo) + countersize, GFP_KERNEL_ACCOUNT); + if (!newinfo) + return -ENOMEM; + + if (countersize) + memset(newinfo->counters, 0, countersize); + + newinfo->entries = __vmalloc(tmp.entries_size, GFP_KERNEL_ACCOUNT); + if (!newinfo->entries) { + ret = -ENOMEM; + goto free_newinfo; + } + if (copy_from_user( + newinfo->entries, tmp.entries, tmp.entries_size) != 0) { + ret = -EFAULT; + goto free_entries; + } + + ret = do_replace_finish(net, &tmp, newinfo); + if (ret == 0) + return ret; +free_entries: + vfree(newinfo->entries); +free_newinfo: + vfree(newinfo); + return ret; +} + +static void __ebt_unregister_table(struct net *net, struct ebt_table *table) +{ + mutex_lock(&ebt_mutex); + list_del(&table->list); + mutex_unlock(&ebt_mutex); + audit_log_nfcfg(table->name, AF_BRIDGE, table->private->nentries, + AUDIT_XT_OP_UNREGISTER, GFP_KERNEL); + EBT_ENTRY_ITERATE(table->private->entries, table->private->entries_size, + ebt_cleanup_entry, net, NULL); + if (table->private->nentries) + module_put(table->me); + vfree(table->private->entries); + ebt_free_table_info(table->private); + vfree(table->private); + kfree(table->ops); + kfree(table); +} + +int ebt_register_table(struct net *net, const struct ebt_table *input_table, + const struct nf_hook_ops *template_ops) +{ + struct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id); + struct ebt_table_info *newinfo; + struct ebt_table *t, *table; + struct nf_hook_ops *ops; + unsigned int num_ops; + struct ebt_replace_kernel *repl; + int ret, i, countersize; + void *p; + + if (input_table == NULL || (repl = input_table->table) == NULL || + repl->entries == NULL || repl->entries_size == 0 || + repl->counters != NULL || input_table->private != NULL) + return -EINVAL; + + /* Don't add one table to multiple lists. */ + table = kmemdup(input_table, sizeof(struct ebt_table), GFP_KERNEL); + if (!table) { + ret = -ENOMEM; + goto out; + } + + countersize = COUNTER_OFFSET(repl->nentries) * nr_cpu_ids; + newinfo = vmalloc(sizeof(*newinfo) + countersize); + ret = -ENOMEM; + if (!newinfo) + goto free_table; + + p = vmalloc(repl->entries_size); + if (!p) + goto free_newinfo; + + memcpy(p, repl->entries, repl->entries_size); + newinfo->entries = p; + + newinfo->entries_size = repl->entries_size; + newinfo->nentries = repl->nentries; + + if (countersize) + memset(newinfo->counters, 0, countersize); + + /* fill in newinfo and parse the entries */ + newinfo->chainstack = NULL; + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + if ((repl->valid_hooks & (1 << i)) == 0) + newinfo->hook_entry[i] = NULL; + else + newinfo->hook_entry[i] = p + + ((char *)repl->hook_entry[i] - repl->entries); + } + ret = translate_table(net, repl->name, newinfo); + if (ret != 0) + goto free_chainstack; + + table->private = newinfo; + rwlock_init(&table->lock); + mutex_lock(&ebt_mutex); + list_for_each_entry(t, &ebt_net->tables, list) { + if (strcmp(t->name, table->name) == 0) { + ret = -EEXIST; + goto free_unlock; + } + } + + /* Hold a reference count if the chains aren't empty */ + if (newinfo->nentries && !try_module_get(table->me)) { + ret = -ENOENT; + goto free_unlock; + } + + num_ops = hweight32(table->valid_hooks); + if (num_ops == 0) { + ret = -EINVAL; + goto free_unlock; + } + + ops = kmemdup(template_ops, sizeof(*ops) * num_ops, GFP_KERNEL); + if (!ops) { + ret = -ENOMEM; + if (newinfo->nentries) + module_put(table->me); + goto free_unlock; + } + + for (i = 0; i < num_ops; i++) + ops[i].priv = table; + + list_add(&table->list, &ebt_net->tables); + mutex_unlock(&ebt_mutex); + + table->ops = ops; + ret = nf_register_net_hooks(net, ops, num_ops); + if (ret) + __ebt_unregister_table(net, table); + + audit_log_nfcfg(repl->name, AF_BRIDGE, repl->nentries, + AUDIT_XT_OP_REGISTER, GFP_KERNEL); + return ret; +free_unlock: + mutex_unlock(&ebt_mutex); +free_chainstack: + ebt_free_table_info(newinfo); + vfree(newinfo->entries); +free_newinfo: + vfree(newinfo); +free_table: + kfree(table); +out: + return ret; +} + +int ebt_register_template(const struct ebt_table *t, int (*table_init)(struct net *net)) +{ + struct ebt_template *tmpl; + + mutex_lock(&ebt_mutex); + list_for_each_entry(tmpl, &template_tables, list) { + if (WARN_ON_ONCE(strcmp(t->name, tmpl->name) == 0)) { + mutex_unlock(&ebt_mutex); + return -EEXIST; + } + } + + tmpl = kzalloc(sizeof(*tmpl), GFP_KERNEL); + if (!tmpl) { + mutex_unlock(&ebt_mutex); + return -ENOMEM; + } + + tmpl->table_init = table_init; + strscpy(tmpl->name, t->name, sizeof(tmpl->name)); + tmpl->owner = t->me; + list_add(&tmpl->list, &template_tables); + + mutex_unlock(&ebt_mutex); + return 0; +} +EXPORT_SYMBOL(ebt_register_template); + +void ebt_unregister_template(const struct ebt_table *t) +{ + struct ebt_template *tmpl; + + mutex_lock(&ebt_mutex); + list_for_each_entry(tmpl, &template_tables, list) { + if (strcmp(t->name, tmpl->name)) + continue; + + list_del(&tmpl->list); + mutex_unlock(&ebt_mutex); + kfree(tmpl); + return; + } + + mutex_unlock(&ebt_mutex); + WARN_ON_ONCE(1); +} +EXPORT_SYMBOL(ebt_unregister_template); + +static struct ebt_table *__ebt_find_table(struct net *net, const char *name) +{ + struct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id); + struct ebt_table *t; + + mutex_lock(&ebt_mutex); + + list_for_each_entry(t, &ebt_net->tables, list) { + if (strcmp(t->name, name) == 0) { + mutex_unlock(&ebt_mutex); + return t; + } + } + + mutex_unlock(&ebt_mutex); + return NULL; +} + +void ebt_unregister_table_pre_exit(struct net *net, const char *name) +{ + struct ebt_table *table = __ebt_find_table(net, name); + + if (table) + nf_unregister_net_hooks(net, table->ops, hweight32(table->valid_hooks)); +} +EXPORT_SYMBOL(ebt_unregister_table_pre_exit); + +void ebt_unregister_table(struct net *net, const char *name) +{ + struct ebt_table *table = __ebt_find_table(net, name); + + if (table) + __ebt_unregister_table(net, table); +} + +/* userspace just supplied us with counters */ +static int do_update_counters(struct net *net, const char *name, + struct ebt_counter __user *counters, + unsigned int num_counters, unsigned int len) +{ + int i, ret; + struct ebt_counter *tmp; + struct ebt_table *t; + + if (num_counters == 0) + return -EINVAL; + + tmp = vmalloc(array_size(num_counters, sizeof(*tmp))); + if (!tmp) + return -ENOMEM; + + t = find_table_lock(net, name, &ret, &ebt_mutex); + if (!t) + goto free_tmp; + + if (num_counters != t->private->nentries) { + ret = -EINVAL; + goto unlock_mutex; + } + + if (copy_from_user(tmp, counters, + array_size(num_counters, sizeof(*counters)))) { + ret = -EFAULT; + goto unlock_mutex; + } + + /* we want an atomic add of the counters */ + write_lock_bh(&t->lock); + + /* we add to the counters of the first cpu */ + for (i = 0; i < num_counters; i++) + ADD_COUNTER(t->private->counters[i], tmp[i].bcnt, tmp[i].pcnt); + + write_unlock_bh(&t->lock); + ret = 0; +unlock_mutex: + mutex_unlock(&ebt_mutex); +free_tmp: + vfree(tmp); + return ret; +} + +static int update_counters(struct net *net, sockptr_t arg, unsigned int len) +{ + struct ebt_replace hlp; + + if (copy_from_sockptr(&hlp, arg, sizeof(hlp))) + return -EFAULT; + + if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) + return -EINVAL; + + return do_update_counters(net, hlp.name, hlp.counters, + hlp.num_counters, len); +} + +static inline int ebt_obj_to_user(char __user *um, const char *_name, + const char *data, int entrysize, + int usersize, int datasize, u8 revision) +{ + char name[EBT_EXTENSION_MAXNAMELEN] = {0}; + + /* ebtables expects 31 bytes long names but xt_match names are 29 bytes + * long. Copy 29 bytes and fill remaining bytes with zeroes. + */ + strscpy(name, _name, sizeof(name)); + if (copy_to_user(um, name, EBT_EXTENSION_MAXNAMELEN) || + put_user(revision, (u8 __user *)(um + EBT_EXTENSION_MAXNAMELEN)) || + put_user(datasize, (int __user *)(um + EBT_EXTENSION_MAXNAMELEN + 1)) || + xt_data_to_user(um + entrysize, data, usersize, datasize, + XT_ALIGN(datasize))) + return -EFAULT; + + return 0; +} + +static inline int ebt_match_to_user(const struct ebt_entry_match *m, + const char *base, char __user *ubase) +{ + return ebt_obj_to_user(ubase + ((char *)m - base), + m->u.match->name, m->data, sizeof(*m), + m->u.match->usersize, m->match_size, + m->u.match->revision); +} + +static inline int ebt_watcher_to_user(const struct ebt_entry_watcher *w, + const char *base, char __user *ubase) +{ + return ebt_obj_to_user(ubase + ((char *)w - base), + w->u.watcher->name, w->data, sizeof(*w), + w->u.watcher->usersize, w->watcher_size, + w->u.watcher->revision); +} + +static inline int ebt_entry_to_user(struct ebt_entry *e, const char *base, + char __user *ubase) +{ + int ret; + char __user *hlp; + const struct ebt_entry_target *t; + + if (e->bitmask == 0) { + /* special case !EBT_ENTRY_OR_ENTRIES */ + if (copy_to_user(ubase + ((char *)e - base), e, + sizeof(struct ebt_entries))) + return -EFAULT; + return 0; + } + + if (copy_to_user(ubase + ((char *)e - base), e, sizeof(*e))) + return -EFAULT; + + hlp = ubase + (((char *)e + e->target_offset) - base); + t = ebt_get_target_c(e); + + ret = EBT_MATCH_ITERATE(e, ebt_match_to_user, base, ubase); + if (ret != 0) + return ret; + ret = EBT_WATCHER_ITERATE(e, ebt_watcher_to_user, base, ubase); + if (ret != 0) + return ret; + ret = ebt_obj_to_user(hlp, t->u.target->name, t->data, sizeof(*t), + t->u.target->usersize, t->target_size, + t->u.target->revision); + if (ret != 0) + return ret; + + return 0; +} + +static int copy_counters_to_user(struct ebt_table *t, + const struct ebt_counter *oldcounters, + void __user *user, unsigned int num_counters, + unsigned int nentries) +{ + struct ebt_counter *counterstmp; + int ret = 0; + + /* userspace might not need the counters */ + if (num_counters == 0) + return 0; + + if (num_counters != nentries) + return -EINVAL; + + counterstmp = vmalloc(array_size(nentries, sizeof(*counterstmp))); + if (!counterstmp) + return -ENOMEM; + + write_lock_bh(&t->lock); + get_counters(oldcounters, counterstmp, nentries); + write_unlock_bh(&t->lock); + + if (copy_to_user(user, counterstmp, + array_size(nentries, sizeof(struct ebt_counter)))) + ret = -EFAULT; + vfree(counterstmp); + return ret; +} + +/* called with ebt_mutex locked */ +static int copy_everything_to_user(struct ebt_table *t, void __user *user, + const int *len, int cmd) +{ + struct ebt_replace tmp; + const struct ebt_counter *oldcounters; + unsigned int entries_size, nentries; + int ret; + char *entries; + + if (cmd == EBT_SO_GET_ENTRIES) { + entries_size = t->private->entries_size; + nentries = t->private->nentries; + entries = t->private->entries; + oldcounters = t->private->counters; + } else { + entries_size = t->table->entries_size; + nentries = t->table->nentries; + entries = t->table->entries; + oldcounters = t->table->counters; + } + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + if (*len != sizeof(struct ebt_replace) + entries_size + + (tmp.num_counters ? nentries * sizeof(struct ebt_counter) : 0)) + return -EINVAL; + + if (tmp.nentries != nentries) + return -EINVAL; + + if (tmp.entries_size != entries_size) + return -EINVAL; + + ret = copy_counters_to_user(t, oldcounters, tmp.counters, + tmp.num_counters, nentries); + if (ret) + return ret; + + /* set the match/watcher/target names right */ + return EBT_ENTRY_ITERATE(entries, entries_size, + ebt_entry_to_user, entries, tmp.entries); +} + +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT +/* 32 bit-userspace compatibility definitions. */ +struct compat_ebt_replace { + char name[EBT_TABLE_MAXNAMELEN]; + compat_uint_t valid_hooks; + compat_uint_t nentries; + compat_uint_t entries_size; + /* start of the chains */ + compat_uptr_t hook_entry[NF_BR_NUMHOOKS]; + /* nr of counters userspace expects back */ + compat_uint_t num_counters; + /* where the kernel will put the old counters. */ + compat_uptr_t counters; + compat_uptr_t entries; +}; + +/* struct ebt_entry_match, _target and _watcher have same layout */ +struct compat_ebt_entry_mwt { + union { + struct { + char name[EBT_EXTENSION_MAXNAMELEN]; + u8 revision; + }; + compat_uptr_t ptr; + } u; + compat_uint_t match_size; + compat_uint_t data[] __aligned(__alignof__(struct compat_ebt_replace)); +}; + +/* account for possible padding between match_size and ->data */ +static int ebt_compat_entry_padsize(void) +{ + BUILD_BUG_ON(sizeof(struct ebt_entry_match) < + sizeof(struct compat_ebt_entry_mwt)); + return (int) sizeof(struct ebt_entry_match) - + sizeof(struct compat_ebt_entry_mwt); +} + +static int ebt_compat_match_offset(const struct xt_match *match, + unsigned int userlen) +{ + /* ebt_among needs special handling. The kernel .matchsize is + * set to -1 at registration time; at runtime an EBT_ALIGN()ed + * value is expected. + * Example: userspace sends 4500, ebt_among.c wants 4504. + */ + if (unlikely(match->matchsize == -1)) + return XT_ALIGN(userlen) - COMPAT_XT_ALIGN(userlen); + return xt_compat_match_offset(match); +} + +static int compat_match_to_user(struct ebt_entry_match *m, void __user **dstptr, + unsigned int *size) +{ + const struct xt_match *match = m->u.match; + struct compat_ebt_entry_mwt __user *cm = *dstptr; + int off = ebt_compat_match_offset(match, m->match_size); + compat_uint_t msize = m->match_size - off; + + if (WARN_ON(off >= m->match_size)) + return -EINVAL; + + if (copy_to_user(cm->u.name, match->name, strlen(match->name) + 1) || + put_user(match->revision, &cm->u.revision) || + put_user(msize, &cm->match_size)) + return -EFAULT; + + if (match->compat_to_user) { + if (match->compat_to_user(cm->data, m->data)) + return -EFAULT; + } else { + if (xt_data_to_user(cm->data, m->data, match->usersize, msize, + COMPAT_XT_ALIGN(msize))) + return -EFAULT; + } + + *size -= ebt_compat_entry_padsize() + off; + *dstptr = cm->data; + *dstptr += msize; + return 0; +} + +static int compat_target_to_user(struct ebt_entry_target *t, + void __user **dstptr, + unsigned int *size) +{ + const struct xt_target *target = t->u.target; + struct compat_ebt_entry_mwt __user *cm = *dstptr; + int off = xt_compat_target_offset(target); + compat_uint_t tsize = t->target_size - off; + + if (WARN_ON(off >= t->target_size)) + return -EINVAL; + + if (copy_to_user(cm->u.name, target->name, strlen(target->name) + 1) || + put_user(target->revision, &cm->u.revision) || + put_user(tsize, &cm->match_size)) + return -EFAULT; + + if (target->compat_to_user) { + if (target->compat_to_user(cm->data, t->data)) + return -EFAULT; + } else { + if (xt_data_to_user(cm->data, t->data, target->usersize, tsize, + COMPAT_XT_ALIGN(tsize))) + return -EFAULT; + } + + *size -= ebt_compat_entry_padsize() + off; + *dstptr = cm->data; + *dstptr += tsize; + return 0; +} + +static int compat_watcher_to_user(struct ebt_entry_watcher *w, + void __user **dstptr, + unsigned int *size) +{ + return compat_target_to_user((struct ebt_entry_target *)w, + dstptr, size); +} + +static int compat_copy_entry_to_user(struct ebt_entry *e, void __user **dstptr, + unsigned int *size) +{ + struct ebt_entry_target *t; + struct ebt_entry __user *ce; + u32 watchers_offset, target_offset, next_offset; + compat_uint_t origsize; + int ret; + + if (e->bitmask == 0) { + if (*size < sizeof(struct ebt_entries)) + return -EINVAL; + if (copy_to_user(*dstptr, e, sizeof(struct ebt_entries))) + return -EFAULT; + + *dstptr += sizeof(struct ebt_entries); + *size -= sizeof(struct ebt_entries); + return 0; + } + + if (*size < sizeof(*ce)) + return -EINVAL; + + ce = *dstptr; + if (copy_to_user(ce, e, sizeof(*ce))) + return -EFAULT; + + origsize = *size; + *dstptr += sizeof(*ce); + + ret = EBT_MATCH_ITERATE(e, compat_match_to_user, dstptr, size); + if (ret) + return ret; + watchers_offset = e->watchers_offset - (origsize - *size); + + ret = EBT_WATCHER_ITERATE(e, compat_watcher_to_user, dstptr, size); + if (ret) + return ret; + target_offset = e->target_offset - (origsize - *size); + + t = ebt_get_target(e); + + ret = compat_target_to_user(t, dstptr, size); + if (ret) + return ret; + next_offset = e->next_offset - (origsize - *size); + + if (put_user(watchers_offset, &ce->watchers_offset) || + put_user(target_offset, &ce->target_offset) || + put_user(next_offset, &ce->next_offset)) + return -EFAULT; + + *size -= sizeof(*ce); + return 0; +} + +static int compat_calc_match(struct ebt_entry_match *m, int *off) +{ + *off += ebt_compat_match_offset(m->u.match, m->match_size); + *off += ebt_compat_entry_padsize(); + return 0; +} + +static int compat_calc_watcher(struct ebt_entry_watcher *w, int *off) +{ + *off += xt_compat_target_offset(w->u.watcher); + *off += ebt_compat_entry_padsize(); + return 0; +} + +static int compat_calc_entry(const struct ebt_entry *e, + const struct ebt_table_info *info, + const void *base, + struct compat_ebt_replace *newinfo) +{ + const struct ebt_entry_target *t; + unsigned int entry_offset; + int off, ret, i; + + if (e->bitmask == 0) + return 0; + + off = 0; + entry_offset = (void *)e - base; + + EBT_MATCH_ITERATE(e, compat_calc_match, &off); + EBT_WATCHER_ITERATE(e, compat_calc_watcher, &off); + + t = ebt_get_target_c(e); + + off += xt_compat_target_offset(t->u.target); + off += ebt_compat_entry_padsize(); + + newinfo->entries_size -= off; + + ret = xt_compat_add_offset(NFPROTO_BRIDGE, entry_offset, off); + if (ret) + return ret; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + const void *hookptr = info->hook_entry[i]; + if (info->hook_entry[i] && + (e < (struct ebt_entry *)(base - hookptr))) { + newinfo->hook_entry[i] -= off; + pr_debug("0x%08X -> 0x%08X\n", + newinfo->hook_entry[i] + off, + newinfo->hook_entry[i]); + } + } + + return 0; +} + +static int ebt_compat_init_offsets(unsigned int number) +{ + if (number > INT_MAX) + return -EINVAL; + + /* also count the base chain policies */ + number += NF_BR_NUMHOOKS; + + return xt_compat_init_offsets(NFPROTO_BRIDGE, number); +} + +static int compat_table_info(const struct ebt_table_info *info, + struct compat_ebt_replace *newinfo) +{ + unsigned int size = info->entries_size; + const void *entries = info->entries; + int ret; + + newinfo->entries_size = size; + ret = ebt_compat_init_offsets(info->nentries); + if (ret) + return ret; + + return EBT_ENTRY_ITERATE(entries, size, compat_calc_entry, info, + entries, newinfo); +} + +static int compat_copy_everything_to_user(struct ebt_table *t, + void __user *user, int *len, int cmd) +{ + struct compat_ebt_replace repl, tmp; + struct ebt_counter *oldcounters; + struct ebt_table_info tinfo; + int ret; + void __user *pos; + + memset(&tinfo, 0, sizeof(tinfo)); + + if (cmd == EBT_SO_GET_ENTRIES) { + tinfo.entries_size = t->private->entries_size; + tinfo.nentries = t->private->nentries; + tinfo.entries = t->private->entries; + oldcounters = t->private->counters; + } else { + tinfo.entries_size = t->table->entries_size; + tinfo.nentries = t->table->nentries; + tinfo.entries = t->table->entries; + oldcounters = t->table->counters; + } + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + if (tmp.nentries != tinfo.nentries || + (tmp.num_counters && tmp.num_counters != tinfo.nentries)) + return -EINVAL; + + memcpy(&repl, &tmp, sizeof(repl)); + if (cmd == EBT_SO_GET_ENTRIES) + ret = compat_table_info(t->private, &repl); + else + ret = compat_table_info(&tinfo, &repl); + if (ret) + return ret; + + if (*len != sizeof(tmp) + repl.entries_size + + (tmp.num_counters? tinfo.nentries * sizeof(struct ebt_counter): 0)) { + pr_err("wrong size: *len %d, entries_size %u, replsz %d\n", + *len, tinfo.entries_size, repl.entries_size); + return -EINVAL; + } + + /* userspace might not need the counters */ + ret = copy_counters_to_user(t, oldcounters, compat_ptr(tmp.counters), + tmp.num_counters, tinfo.nentries); + if (ret) + return ret; + + pos = compat_ptr(tmp.entries); + return EBT_ENTRY_ITERATE(tinfo.entries, tinfo.entries_size, + compat_copy_entry_to_user, &pos, &tmp.entries_size); +} + +struct ebt_entries_buf_state { + char *buf_kern_start; /* kernel buffer to copy (translated) data to */ + u32 buf_kern_len; /* total size of kernel buffer */ + u32 buf_kern_offset; /* amount of data copied so far */ + u32 buf_user_offset; /* read position in userspace buffer */ +}; + +static int ebt_buf_count(struct ebt_entries_buf_state *state, unsigned int sz) +{ + state->buf_kern_offset += sz; + return state->buf_kern_offset >= sz ? 0 : -EINVAL; +} + +static int ebt_buf_add(struct ebt_entries_buf_state *state, + const void *data, unsigned int sz) +{ + if (state->buf_kern_start == NULL) + goto count_only; + + if (WARN_ON(state->buf_kern_offset + sz > state->buf_kern_len)) + return -EINVAL; + + memcpy(state->buf_kern_start + state->buf_kern_offset, data, sz); + + count_only: + state->buf_user_offset += sz; + return ebt_buf_count(state, sz); +} + +static int ebt_buf_add_pad(struct ebt_entries_buf_state *state, unsigned int sz) +{ + char *b = state->buf_kern_start; + + if (WARN_ON(b && state->buf_kern_offset > state->buf_kern_len)) + return -EINVAL; + + if (b != NULL && sz > 0) + memset(b + state->buf_kern_offset, 0, sz); + /* do not adjust ->buf_user_offset here, we added kernel-side padding */ + return ebt_buf_count(state, sz); +} + +enum compat_mwt { + EBT_COMPAT_MATCH, + EBT_COMPAT_WATCHER, + EBT_COMPAT_TARGET, +}; + +static int compat_mtw_from_user(const struct compat_ebt_entry_mwt *mwt, + enum compat_mwt compat_mwt, + struct ebt_entries_buf_state *state, + const unsigned char *base) +{ + char name[EBT_EXTENSION_MAXNAMELEN]; + struct xt_match *match; + struct xt_target *wt; + void *dst = NULL; + int off, pad = 0; + unsigned int size_kern, match_size = mwt->match_size; + + if (strscpy(name, mwt->u.name, sizeof(name)) < 0) + return -EINVAL; + + if (state->buf_kern_start) + dst = state->buf_kern_start + state->buf_kern_offset; + + switch (compat_mwt) { + case EBT_COMPAT_MATCH: + match = xt_request_find_match(NFPROTO_BRIDGE, name, + mwt->u.revision); + if (IS_ERR(match)) + return PTR_ERR(match); + + off = ebt_compat_match_offset(match, match_size); + if (dst) { + if (match->compat_from_user) + match->compat_from_user(dst, mwt->data); + else + memcpy(dst, mwt->data, match_size); + } + + size_kern = match->matchsize; + if (unlikely(size_kern == -1)) + size_kern = match_size; + module_put(match->me); + break; + case EBT_COMPAT_WATCHER: + case EBT_COMPAT_TARGET: + wt = xt_request_find_target(NFPROTO_BRIDGE, name, + mwt->u.revision); + if (IS_ERR(wt)) + return PTR_ERR(wt); + off = xt_compat_target_offset(wt); + + if (dst) { + if (wt->compat_from_user) + wt->compat_from_user(dst, mwt->data); + else + memcpy(dst, mwt->data, match_size); + } + + size_kern = wt->targetsize; + module_put(wt->me); + break; + + default: + return -EINVAL; + } + + state->buf_kern_offset += match_size + off; + state->buf_user_offset += match_size; + pad = XT_ALIGN(size_kern) - size_kern; + + if (pad > 0 && dst) { + if (WARN_ON(state->buf_kern_len <= pad)) + return -EINVAL; + if (WARN_ON(state->buf_kern_offset - (match_size + off) + size_kern > state->buf_kern_len - pad)) + return -EINVAL; + memset(dst + size_kern, 0, pad); + } + return off + match_size; +} + +/* return size of all matches, watchers or target, including necessary + * alignment and padding. + */ +static int ebt_size_mwt(const struct compat_ebt_entry_mwt *match32, + unsigned int size_left, enum compat_mwt type, + struct ebt_entries_buf_state *state, const void *base) +{ + const char *buf = (const char *)match32; + int growth = 0; + + if (size_left == 0) + return 0; + + do { + struct ebt_entry_match *match_kern; + int ret; + + if (size_left < sizeof(*match32)) + return -EINVAL; + + match_kern = (struct ebt_entry_match *) state->buf_kern_start; + if (match_kern) { + char *tmp; + tmp = state->buf_kern_start + state->buf_kern_offset; + match_kern = (struct ebt_entry_match *) tmp; + } + ret = ebt_buf_add(state, buf, sizeof(*match32)); + if (ret < 0) + return ret; + size_left -= sizeof(*match32); + + /* add padding before match->data (if any) */ + ret = ebt_buf_add_pad(state, ebt_compat_entry_padsize()); + if (ret < 0) + return ret; + + if (match32->match_size > size_left) + return -EINVAL; + + size_left -= match32->match_size; + + ret = compat_mtw_from_user(match32, type, state, base); + if (ret < 0) + return ret; + + if (WARN_ON(ret < match32->match_size)) + return -EINVAL; + growth += ret - match32->match_size; + growth += ebt_compat_entry_padsize(); + + buf += sizeof(*match32); + buf += match32->match_size; + + if (match_kern) + match_kern->match_size = ret; + + match32 = (struct compat_ebt_entry_mwt *) buf; + } while (size_left); + + return growth; +} + +/* called for all ebt_entry structures. */ +static int size_entry_mwt(const struct ebt_entry *entry, const unsigned char *base, + unsigned int *total, + struct ebt_entries_buf_state *state) +{ + unsigned int i, j, startoff, next_expected_off, new_offset = 0; + /* stores match/watchers/targets & offset of next struct ebt_entry: */ + unsigned int offsets[4]; + unsigned int *offsets_update = NULL; + int ret; + char *buf_start; + + if (*total < sizeof(struct ebt_entries)) + return -EINVAL; + + if (!entry->bitmask) { + *total -= sizeof(struct ebt_entries); + return ebt_buf_add(state, entry, sizeof(struct ebt_entries)); + } + if (*total < sizeof(*entry) || entry->next_offset < sizeof(*entry)) + return -EINVAL; + + startoff = state->buf_user_offset; + /* pull in most part of ebt_entry, it does not need to be changed. */ + ret = ebt_buf_add(state, entry, + offsetof(struct ebt_entry, watchers_offset)); + if (ret < 0) + return ret; + + offsets[0] = sizeof(struct ebt_entry); /* matches come first */ + memcpy(&offsets[1], &entry->offsets, sizeof(entry->offsets)); + + if (state->buf_kern_start) { + buf_start = state->buf_kern_start + state->buf_kern_offset; + offsets_update = (unsigned int *) buf_start; + } + ret = ebt_buf_add(state, &offsets[1], + sizeof(offsets) - sizeof(offsets[0])); + if (ret < 0) + return ret; + buf_start = (char *) entry; + /* 0: matches offset, always follows ebt_entry. + * 1: watchers offset, from ebt_entry structure + * 2: target offset, from ebt_entry structure + * 3: next ebt_entry offset, from ebt_entry structure + * + * offsets are relative to beginning of struct ebt_entry (i.e., 0). + */ + for (i = 0; i < 4 ; ++i) { + if (offsets[i] > *total) + return -EINVAL; + + if (i < 3 && offsets[i] == *total) + return -EINVAL; + + if (i == 0) + continue; + if (offsets[i-1] > offsets[i]) + return -EINVAL; + } + + for (i = 0, j = 1 ; j < 4 ; j++, i++) { + struct compat_ebt_entry_mwt *match32; + unsigned int size; + char *buf = buf_start + offsets[i]; + + if (offsets[i] > offsets[j]) + return -EINVAL; + + match32 = (struct compat_ebt_entry_mwt *) buf; + size = offsets[j] - offsets[i]; + ret = ebt_size_mwt(match32, size, i, state, base); + if (ret < 0) + return ret; + new_offset += ret; + if (offsets_update && new_offset) { + pr_debug("change offset %d to %d\n", + offsets_update[i], offsets[j] + new_offset); + offsets_update[i] = offsets[j] + new_offset; + } + } + + if (state->buf_kern_start == NULL) { + unsigned int offset = buf_start - (char *) base; + + ret = xt_compat_add_offset(NFPROTO_BRIDGE, offset, new_offset); + if (ret < 0) + return ret; + } + + next_expected_off = state->buf_user_offset - startoff; + if (next_expected_off != entry->next_offset) + return -EINVAL; + + if (*total < entry->next_offset) + return -EINVAL; + *total -= entry->next_offset; + return 0; +} + +/* repl->entries_size is the size of the ebt_entry blob in userspace. + * It might need more memory when copied to a 64 bit kernel in case + * userspace is 32-bit. So, first task: find out how much memory is needed. + * + * Called before validation is performed. + */ +static int compat_copy_entries(unsigned char *data, unsigned int size_user, + struct ebt_entries_buf_state *state) +{ + unsigned int size_remaining = size_user; + int ret; + + ret = EBT_ENTRY_ITERATE(data, size_user, size_entry_mwt, data, + &size_remaining, state); + if (ret < 0) + return ret; + + if (size_remaining) + return -EINVAL; + + return state->buf_kern_offset; +} + + +static int compat_copy_ebt_replace_from_user(struct ebt_replace *repl, + sockptr_t arg, unsigned int len) +{ + struct compat_ebt_replace tmp; + int i; + + if (len < sizeof(tmp)) + return -EINVAL; + + if (copy_from_sockptr(&tmp, arg, sizeof(tmp))) + return -EFAULT; + + if (len != sizeof(tmp) + tmp.entries_size) + return -EINVAL; + + if (tmp.entries_size == 0) + return -EINVAL; + + if (tmp.nentries >= ((INT_MAX - sizeof(struct ebt_table_info)) / + NR_CPUS - SMP_CACHE_BYTES) / sizeof(struct ebt_counter)) + return -ENOMEM; + if (tmp.num_counters >= INT_MAX / sizeof(struct ebt_counter)) + return -ENOMEM; + + memcpy(repl, &tmp, offsetof(struct ebt_replace, hook_entry)); + + /* starting with hook_entry, 32 vs. 64 bit structures are different */ + for (i = 0; i < NF_BR_NUMHOOKS; i++) + repl->hook_entry[i] = compat_ptr(tmp.hook_entry[i]); + + repl->num_counters = tmp.num_counters; + repl->counters = compat_ptr(tmp.counters); + repl->entries = compat_ptr(tmp.entries); + return 0; +} + +static int compat_do_replace(struct net *net, sockptr_t arg, unsigned int len) +{ + int ret, i, countersize, size64; + struct ebt_table_info *newinfo; + struct ebt_replace tmp; + struct ebt_entries_buf_state state; + void *entries_tmp; + + ret = compat_copy_ebt_replace_from_user(&tmp, arg, len); + if (ret) { + /* try real handler in case userland supplied needed padding */ + if (ret == -EINVAL && do_replace(net, arg, len) == 0) + ret = 0; + return ret; + } + + countersize = COUNTER_OFFSET(tmp.nentries) * nr_cpu_ids; + newinfo = vmalloc(sizeof(*newinfo) + countersize); + if (!newinfo) + return -ENOMEM; + + if (countersize) + memset(newinfo->counters, 0, countersize); + + memset(&state, 0, sizeof(state)); + + newinfo->entries = vmalloc(tmp.entries_size); + if (!newinfo->entries) { + ret = -ENOMEM; + goto free_newinfo; + } + if (copy_from_user( + newinfo->entries, tmp.entries, tmp.entries_size) != 0) { + ret = -EFAULT; + goto free_entries; + } + + entries_tmp = newinfo->entries; + + xt_compat_lock(NFPROTO_BRIDGE); + + ret = ebt_compat_init_offsets(tmp.nentries); + if (ret < 0) + goto out_unlock; + + ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); + if (ret < 0) + goto out_unlock; + + pr_debug("tmp.entries_size %d, kern off %d, user off %d delta %d\n", + tmp.entries_size, state.buf_kern_offset, state.buf_user_offset, + xt_compat_calc_jump(NFPROTO_BRIDGE, tmp.entries_size)); + + size64 = ret; + newinfo->entries = vmalloc(size64); + if (!newinfo->entries) { + vfree(entries_tmp); + ret = -ENOMEM; + goto out_unlock; + } + + memset(&state, 0, sizeof(state)); + state.buf_kern_start = newinfo->entries; + state.buf_kern_len = size64; + + ret = compat_copy_entries(entries_tmp, tmp.entries_size, &state); + if (WARN_ON(ret < 0)) { + vfree(entries_tmp); + goto out_unlock; + } + + vfree(entries_tmp); + tmp.entries_size = size64; + + for (i = 0; i < NF_BR_NUMHOOKS; i++) { + char __user *usrptr; + if (tmp.hook_entry[i]) { + unsigned int delta; + usrptr = (char __user *) tmp.hook_entry[i]; + delta = usrptr - tmp.entries; + usrptr += xt_compat_calc_jump(NFPROTO_BRIDGE, delta); + tmp.hook_entry[i] = (struct ebt_entries __user *)usrptr; + } + } + + xt_compat_flush_offsets(NFPROTO_BRIDGE); + xt_compat_unlock(NFPROTO_BRIDGE); + + ret = do_replace_finish(net, &tmp, newinfo); + if (ret == 0) + return ret; +free_entries: + vfree(newinfo->entries); +free_newinfo: + vfree(newinfo); + return ret; +out_unlock: + xt_compat_flush_offsets(NFPROTO_BRIDGE); + xt_compat_unlock(NFPROTO_BRIDGE); + goto free_entries; +} + +static int compat_update_counters(struct net *net, sockptr_t arg, + unsigned int len) +{ + struct compat_ebt_replace hlp; + + if (copy_from_sockptr(&hlp, arg, sizeof(hlp))) + return -EFAULT; + + /* try real handler in case userland supplied needed padding */ + if (len != sizeof(hlp) + hlp.num_counters * sizeof(struct ebt_counter)) + return update_counters(net, arg, len); + + return do_update_counters(net, hlp.name, compat_ptr(hlp.counters), + hlp.num_counters, len); +} + +static int compat_do_ebt_get_ctl(struct sock *sk, int cmd, + void __user *user, int *len) +{ + int ret; + struct compat_ebt_replace tmp; + struct ebt_table *t; + struct net *net = sock_net(sk); + + if ((cmd == EBT_SO_GET_INFO || cmd == EBT_SO_GET_INIT_INFO) && + *len != sizeof(struct compat_ebt_replace)) + return -EINVAL; + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + tmp.name[sizeof(tmp.name) - 1] = '\0'; + + t = find_table_lock(net, tmp.name, &ret, &ebt_mutex); + if (!t) + return ret; + + xt_compat_lock(NFPROTO_BRIDGE); + switch (cmd) { + case EBT_SO_GET_INFO: + tmp.nentries = t->private->nentries; + ret = compat_table_info(t->private, &tmp); + if (ret) + goto out; + tmp.valid_hooks = t->valid_hooks; + + if (copy_to_user(user, &tmp, *len) != 0) { + ret = -EFAULT; + break; + } + ret = 0; + break; + case EBT_SO_GET_INIT_INFO: + tmp.nentries = t->table->nentries; + tmp.entries_size = t->table->entries_size; + tmp.valid_hooks = t->table->valid_hooks; + + if (copy_to_user(user, &tmp, *len) != 0) { + ret = -EFAULT; + break; + } + ret = 0; + break; + case EBT_SO_GET_ENTRIES: + case EBT_SO_GET_INIT_ENTRIES: + /* try real handler first in case of userland-side padding. + * in case we are dealing with an 'ordinary' 32 bit binary + * without 64bit compatibility padding, this will fail right + * after copy_from_user when the *len argument is validated. + * + * the compat_ variant needs to do one pass over the kernel + * data set to adjust for size differences before it the check. + */ + if (copy_everything_to_user(t, user, len, cmd) == 0) + ret = 0; + else + ret = compat_copy_everything_to_user(t, user, len, cmd); + break; + default: + ret = -EINVAL; + } + out: + xt_compat_flush_offsets(NFPROTO_BRIDGE); + xt_compat_unlock(NFPROTO_BRIDGE); + mutex_unlock(&ebt_mutex); + return ret; +} +#endif + +static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len) +{ + struct net *net = sock_net(sk); + struct ebt_replace tmp; + struct ebt_table *t; + int ret; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + /* try real handler in case userland supplied needed padding */ + if (in_compat_syscall() && + ((cmd != EBT_SO_GET_INFO && cmd != EBT_SO_GET_INIT_INFO) || + *len != sizeof(tmp))) + return compat_do_ebt_get_ctl(sk, cmd, user, len); +#endif + + if (copy_from_user(&tmp, user, sizeof(tmp))) + return -EFAULT; + + tmp.name[sizeof(tmp.name) - 1] = '\0'; + + t = find_table_lock(net, tmp.name, &ret, &ebt_mutex); + if (!t) + return ret; + + switch (cmd) { + case EBT_SO_GET_INFO: + case EBT_SO_GET_INIT_INFO: + if (*len != sizeof(struct ebt_replace)) { + ret = -EINVAL; + mutex_unlock(&ebt_mutex); + break; + } + if (cmd == EBT_SO_GET_INFO) { + tmp.nentries = t->private->nentries; + tmp.entries_size = t->private->entries_size; + tmp.valid_hooks = t->valid_hooks; + } else { + tmp.nentries = t->table->nentries; + tmp.entries_size = t->table->entries_size; + tmp.valid_hooks = t->table->valid_hooks; + } + mutex_unlock(&ebt_mutex); + if (copy_to_user(user, &tmp, *len) != 0) { + ret = -EFAULT; + break; + } + ret = 0; + break; + + case EBT_SO_GET_ENTRIES: + case EBT_SO_GET_INIT_ENTRIES: + ret = copy_everything_to_user(t, user, len, cmd); + mutex_unlock(&ebt_mutex); + break; + + default: + mutex_unlock(&ebt_mutex); + ret = -EINVAL; + } + + return ret; +} + +static int do_ebt_set_ctl(struct sock *sk, int cmd, sockptr_t arg, + unsigned int len) +{ + struct net *net = sock_net(sk); + int ret; + + if (!ns_capable(net->user_ns, CAP_NET_ADMIN)) + return -EPERM; + + switch (cmd) { + case EBT_SO_SET_ENTRIES: +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + if (in_compat_syscall()) + ret = compat_do_replace(net, arg, len); + else +#endif + ret = do_replace(net, arg, len); + break; + case EBT_SO_SET_COUNTERS: +#ifdef CONFIG_NETFILTER_XTABLES_COMPAT + if (in_compat_syscall()) + ret = compat_update_counters(net, arg, len); + else +#endif + ret = update_counters(net, arg, len); + break; + default: + ret = -EINVAL; + } + return ret; +} + +static struct nf_sockopt_ops ebt_sockopts = { + .pf = PF_INET, + .set_optmin = EBT_BASE_CTL, + .set_optmax = EBT_SO_SET_MAX + 1, + .set = do_ebt_set_ctl, + .get_optmin = EBT_BASE_CTL, + .get_optmax = EBT_SO_GET_MAX + 1, + .get = do_ebt_get_ctl, + .owner = THIS_MODULE, +}; + +static int __net_init ebt_pernet_init(struct net *net) +{ + struct ebt_pernet *ebt_net = net_generic(net, ebt_pernet_id); + + INIT_LIST_HEAD(&ebt_net->tables); + return 0; +} + +static struct pernet_operations ebt_net_ops = { + .init = ebt_pernet_init, + .id = &ebt_pernet_id, + .size = sizeof(struct ebt_pernet), +}; + +static int __init ebtables_init(void) +{ + int ret; + + ret = xt_register_target(&ebt_standard_target); + if (ret < 0) + return ret; + ret = nf_register_sockopt(&ebt_sockopts); + if (ret < 0) { + xt_unregister_target(&ebt_standard_target); + return ret; + } + + ret = register_pernet_subsys(&ebt_net_ops); + if (ret < 0) { + nf_unregister_sockopt(&ebt_sockopts); + xt_unregister_target(&ebt_standard_target); + return ret; + } + + return 0; +} + +static void ebtables_fini(void) +{ + nf_unregister_sockopt(&ebt_sockopts); + xt_unregister_target(&ebt_standard_target); + unregister_pernet_subsys(&ebt_net_ops); +} + +EXPORT_SYMBOL(ebt_register_table); +EXPORT_SYMBOL(ebt_unregister_table); +EXPORT_SYMBOL(ebt_do_table); +module_init(ebtables_init); +module_exit(ebtables_fini); +MODULE_LICENSE("GPL"); diff --git a/net/bridge/netfilter/nf_conntrack_bridge.c b/net/bridge/netfilter/nf_conntrack_bridge.c new file mode 100644 index 000000000..0fcf357ea --- /dev/null +++ b/net/bridge/netfilter/nf_conntrack_bridge.c @@ -0,0 +1,418 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#include <linux/types.h> +#include <linux/ip.h> +#include <linux/netfilter.h> +#include <linux/netfilter_ipv6.h> +#include <linux/netfilter_bridge.h> +#include <linux/module.h> +#include <linux/skbuff.h> +#include <linux/icmp.h> +#include <linux/sysctl.h> +#include <net/route.h> +#include <net/ip.h> + +#include <net/netfilter/nf_conntrack.h> +#include <net/netfilter/nf_conntrack_core.h> +#include <net/netfilter/nf_conntrack_helper.h> +#include <net/netfilter/nf_conntrack_bridge.h> + +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> + +#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_bridge_frag_data *data, + int (*output)(struct net *, struct sock *sk, + const struct nf_bridge_frag_data *data, + struct sk_buff *)) +{ + int frag_max_size = BR_INPUT_SKB_CB(skb)->frag_max_size; + bool mono_delivery_time = skb->mono_delivery_time; + unsigned int hlen, ll_rs, mtu; + ktime_t tstamp = skb->tstamp; + struct ip_frag_state state; + struct iphdr *iph; + int err = 0; + + /* 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); + + skb_set_delivery_time(skb, tstamp, mono_delivery_time); + err = output(net, sk, data, skb); + if (err || !iter.frag) + break; + + skb = ip_fraglist_next(&iter); + } + + if (!err) + return 0; + + kfree_skb_list(iter.frag); + + 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, false, &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; + } + + skb_set_delivery_time(skb2, tstamp, mono_delivery_time); + 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) +{ +#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6) + 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_ct_frag6_gather(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; +#else + return NF_ACCEPT; +#endif +} + +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 = skb_ip_totlen(skb); + 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 = skb_ip_totlen(skb); + 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_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_bridge_frag_data *data, + struct sk_buff *)) +{ + struct nf_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_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); + else if (skb_vlan_tag_present(skb)) + __vlan_hwaccel_clear_tag(skb); + + 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_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_post(void *priv, struct sk_buff *skb, + const struct nf_hook_state *state) +{ + int ret; + + ret = nf_confirm(priv, skb, state); + 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/bridge/netfilter/nft_meta_bridge.c b/net/bridge/netfilter/nft_meta_bridge.c new file mode 100644 index 000000000..bd4d1b4d7 --- /dev/null +++ b/net/bridge/netfilter/nft_meta_bridge.c @@ -0,0 +1,243 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/nft_meta.h> +#include <linux/if_bridge.h> +#include <uapi/linux/netfilter_bridge.h> /* NF_BR_PRE_ROUTING */ + +#include "../br_private.h" + +static const struct net_device * +nft_meta_get_bridge(const struct net_device *dev) +{ + if (dev && netif_is_bridge_port(dev)) + return netdev_master_upper_dev_get_rcu((struct net_device *)dev); + + return NULL; +} + +static void nft_meta_bridge_get_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_meta *priv = nft_expr_priv(expr); + const struct net_device *in = nft_in(pkt), *out = nft_out(pkt); + u32 *dest = ®s->data[priv->dreg]; + const struct net_device *br_dev; + + switch (priv->key) { + case NFT_META_BRI_IIFNAME: + br_dev = nft_meta_get_bridge(in); + break; + case NFT_META_BRI_OIFNAME: + br_dev = nft_meta_get_bridge(out); + break; + case NFT_META_BRI_IIFPVID: { + u16 p_pvid; + + br_dev = nft_meta_get_bridge(in); + if (!br_dev || !br_vlan_enabled(br_dev)) + goto err; + + br_vlan_get_pvid_rcu(in, &p_pvid); + nft_reg_store16(dest, p_pvid); + return; + } + case NFT_META_BRI_IIFVPROTO: { + u16 p_proto; + + br_dev = nft_meta_get_bridge(in); + if (!br_dev || !br_vlan_enabled(br_dev)) + goto err; + + br_vlan_get_proto(br_dev, &p_proto); + nft_reg_store_be16(dest, htons(p_proto)); + return; + } + default: + return nft_meta_get_eval(expr, regs, pkt); + } + + strncpy((char *)dest, br_dev ? br_dev->name : "", IFNAMSIZ); + return; +err: + regs->verdict.code = NFT_BREAK; +} + +static int nft_meta_bridge_get_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_meta *priv = nft_expr_priv(expr); + unsigned int len; + + priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); + switch (priv->key) { + case NFT_META_BRI_IIFNAME: + case NFT_META_BRI_OIFNAME: + len = IFNAMSIZ; + break; + case NFT_META_BRI_IIFPVID: + case NFT_META_BRI_IIFVPROTO: + len = sizeof(u16); + break; + default: + return nft_meta_get_init(ctx, expr, tb); + } + + priv->len = len; + return nft_parse_register_store(ctx, tb[NFTA_META_DREG], &priv->dreg, + NULL, NFT_DATA_VALUE, len); +} + +static struct nft_expr_type nft_meta_bridge_type; +static const struct nft_expr_ops nft_meta_bridge_get_ops = { + .type = &nft_meta_bridge_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), + .eval = nft_meta_bridge_get_eval, + .init = nft_meta_bridge_get_init, + .dump = nft_meta_get_dump, + .reduce = nft_meta_get_reduce, +}; + +static void nft_meta_bridge_set_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_meta *meta = nft_expr_priv(expr); + u32 *sreg = ®s->data[meta->sreg]; + struct sk_buff *skb = pkt->skb; + u8 value8; + + switch (meta->key) { + case NFT_META_BRI_BROUTE: + value8 = nft_reg_load8(sreg); + BR_INPUT_SKB_CB(skb)->br_netfilter_broute = !!value8; + break; + default: + nft_meta_set_eval(expr, regs, pkt); + } +} + +static int nft_meta_bridge_set_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_meta *priv = nft_expr_priv(expr); + unsigned int len; + int err; + + priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); + switch (priv->key) { + case NFT_META_BRI_BROUTE: + len = sizeof(u8); + break; + default: + return nft_meta_set_init(ctx, expr, tb); + } + + priv->len = len; + err = nft_parse_register_load(tb[NFTA_META_SREG], &priv->sreg, len); + if (err < 0) + return err; + + return 0; +} + +static bool nft_meta_bridge_set_reduce(struct nft_regs_track *track, + const struct nft_expr *expr) +{ + int i; + + for (i = 0; i < NFT_REG32_NUM; i++) { + if (!track->regs[i].selector) + continue; + + if (track->regs[i].selector->ops != &nft_meta_bridge_get_ops) + continue; + + __nft_reg_track_cancel(track, i); + } + + return false; +} + +static int nft_meta_bridge_set_validate(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nft_data **data) +{ + struct nft_meta *priv = nft_expr_priv(expr); + unsigned int hooks; + + switch (priv->key) { + case NFT_META_BRI_BROUTE: + hooks = 1 << NF_BR_PRE_ROUTING; + break; + default: + return nft_meta_set_validate(ctx, expr, data); + } + + return nft_chain_validate_hooks(ctx->chain, hooks); +} + +static const struct nft_expr_ops nft_meta_bridge_set_ops = { + .type = &nft_meta_bridge_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), + .eval = nft_meta_bridge_set_eval, + .init = nft_meta_bridge_set_init, + .destroy = nft_meta_set_destroy, + .dump = nft_meta_set_dump, + .reduce = nft_meta_bridge_set_reduce, + .validate = nft_meta_bridge_set_validate, +}; + +static const struct nft_expr_ops * +nft_meta_bridge_select_ops(const struct nft_ctx *ctx, + const struct nlattr * const tb[]) +{ + if (tb[NFTA_META_KEY] == NULL) + return ERR_PTR(-EINVAL); + + if (tb[NFTA_META_DREG] && tb[NFTA_META_SREG]) + return ERR_PTR(-EINVAL); + + if (tb[NFTA_META_DREG]) + return &nft_meta_bridge_get_ops; + + if (tb[NFTA_META_SREG]) + return &nft_meta_bridge_set_ops; + + return ERR_PTR(-EINVAL); +} + +static struct nft_expr_type nft_meta_bridge_type __read_mostly = { + .family = NFPROTO_BRIDGE, + .name = "meta", + .select_ops = nft_meta_bridge_select_ops, + .policy = nft_meta_policy, + .maxattr = NFTA_META_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_meta_bridge_module_init(void) +{ + return nft_register_expr(&nft_meta_bridge_type); +} + +static void __exit nft_meta_bridge_module_exit(void) +{ + nft_unregister_expr(&nft_meta_bridge_type); +} + +module_init(nft_meta_bridge_module_init); +module_exit(nft_meta_bridge_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("wenxu <wenxu@ucloud.cn>"); +MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "meta"); +MODULE_DESCRIPTION("Support for bridge dedicated meta key"); diff --git a/net/bridge/netfilter/nft_reject_bridge.c b/net/bridge/netfilter/nft_reject_bridge.c new file mode 100644 index 000000000..71b54fed7 --- /dev/null +++ b/net/bridge/netfilter/nft_reject_bridge.c @@ -0,0 +1,216 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) 2014 Pablo Neira Ayuso <pablo@netfilter.org> + */ + +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/netlink.h> +#include <linux/netfilter.h> +#include <linux/netfilter/nf_tables.h> +#include <net/netfilter/nf_tables.h> +#include <net/netfilter/nft_reject.h> +#include <net/netfilter/ipv4/nf_reject.h> +#include <net/netfilter/ipv6/nf_reject.h> +#include <linux/ip.h> +#include <net/ip.h> +#include <net/ip6_checksum.h> +#include <linux/netfilter_bridge.h> +#include <linux/netfilter_ipv6.h> +#include "../br_private.h" + +static void nft_reject_br_push_etherhdr(struct sk_buff *oldskb, + struct sk_buff *nskb) +{ + struct ethhdr *eth; + + eth = skb_push(nskb, ETH_HLEN); + skb_reset_mac_header(nskb); + ether_addr_copy(eth->h_source, eth_hdr(oldskb)->h_dest); + ether_addr_copy(eth->h_dest, eth_hdr(oldskb)->h_source); + eth->h_proto = eth_hdr(oldskb)->h_proto; + skb_pull(nskb, ETH_HLEN); + + if (skb_vlan_tag_present(oldskb)) { + u16 vid = skb_vlan_tag_get(oldskb); + + __vlan_hwaccel_put_tag(nskb, oldskb->vlan_proto, vid); + } +} + +/* We cannot use oldskb->dev, it can be either bridge device (NF_BRIDGE INPUT) + * or the bridge port (NF_BRIDGE PREROUTING). + */ +static void nft_reject_br_send_v4_tcp_reset(struct net *net, + struct sk_buff *oldskb, + const struct net_device *dev, + int hook) +{ + struct sk_buff *nskb; + + nskb = nf_reject_skb_v4_tcp_reset(net, oldskb, NULL, hook); + if (!nskb) + return; + + nft_reject_br_push_etherhdr(oldskb, nskb); + + br_forward(br_port_get_rcu(dev), nskb, false, true); +} + +static void nft_reject_br_send_v4_unreach(struct net *net, + struct sk_buff *oldskb, + const struct net_device *dev, + int hook, u8 code) +{ + struct sk_buff *nskb; + + nskb = nf_reject_skb_v4_unreach(net, oldskb, NULL, hook, code); + if (!nskb) + return; + + nft_reject_br_push_etherhdr(oldskb, nskb); + + br_forward(br_port_get_rcu(dev), nskb, false, true); +} + +static void nft_reject_br_send_v6_tcp_reset(struct net *net, + struct sk_buff *oldskb, + const struct net_device *dev, + int hook) +{ + struct sk_buff *nskb; + + nskb = nf_reject_skb_v6_tcp_reset(net, oldskb, NULL, hook); + if (!nskb) + return; + + nft_reject_br_push_etherhdr(oldskb, nskb); + + br_forward(br_port_get_rcu(dev), nskb, false, true); +} + + +static void nft_reject_br_send_v6_unreach(struct net *net, + struct sk_buff *oldskb, + const struct net_device *dev, + int hook, u8 code) +{ + struct sk_buff *nskb; + + nskb = nf_reject_skb_v6_unreach(net, oldskb, NULL, hook, code); + if (!nskb) + return; + + nft_reject_br_push_etherhdr(oldskb, nskb); + + br_forward(br_port_get_rcu(dev), nskb, false, true); +} + +static void nft_reject_bridge_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + struct nft_reject *priv = nft_expr_priv(expr); + const unsigned char *dest = eth_hdr(pkt->skb)->h_dest; + + if (is_broadcast_ether_addr(dest) || + is_multicast_ether_addr(dest)) + goto out; + + switch (eth_hdr(pkt->skb)->h_proto) { + case htons(ETH_P_IP): + switch (priv->type) { + case NFT_REJECT_ICMP_UNREACH: + nft_reject_br_send_v4_unreach(nft_net(pkt), pkt->skb, + nft_in(pkt), + nft_hook(pkt), + priv->icmp_code); + break; + case NFT_REJECT_TCP_RST: + nft_reject_br_send_v4_tcp_reset(nft_net(pkt), pkt->skb, + nft_in(pkt), + nft_hook(pkt)); + break; + case NFT_REJECT_ICMPX_UNREACH: + nft_reject_br_send_v4_unreach(nft_net(pkt), pkt->skb, + nft_in(pkt), + nft_hook(pkt), + nft_reject_icmp_code(priv->icmp_code)); + break; + } + break; + case htons(ETH_P_IPV6): + switch (priv->type) { + case NFT_REJECT_ICMP_UNREACH: + nft_reject_br_send_v6_unreach(nft_net(pkt), pkt->skb, + nft_in(pkt), + nft_hook(pkt), + priv->icmp_code); + break; + case NFT_REJECT_TCP_RST: + nft_reject_br_send_v6_tcp_reset(nft_net(pkt), pkt->skb, + nft_in(pkt), + nft_hook(pkt)); + break; + case NFT_REJECT_ICMPX_UNREACH: + nft_reject_br_send_v6_unreach(nft_net(pkt), pkt->skb, + nft_in(pkt), + nft_hook(pkt), + nft_reject_icmpv6_code(priv->icmp_code)); + break; + } + break; + default: + /* No explicit way to reject this protocol, drop it. */ + break; + } +out: + regs->verdict.code = NF_DROP; +} + +static int nft_reject_bridge_validate(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nft_data **data) +{ + return nft_chain_validate_hooks(ctx->chain, (1 << NF_BR_PRE_ROUTING) | + (1 << NF_BR_LOCAL_IN)); +} + +static struct nft_expr_type nft_reject_bridge_type; +static const struct nft_expr_ops nft_reject_bridge_ops = { + .type = &nft_reject_bridge_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_reject)), + .eval = nft_reject_bridge_eval, + .init = nft_reject_init, + .dump = nft_reject_dump, + .validate = nft_reject_bridge_validate, + .reduce = NFT_REDUCE_READONLY, +}; + +static struct nft_expr_type nft_reject_bridge_type __read_mostly = { + .family = NFPROTO_BRIDGE, + .name = "reject", + .ops = &nft_reject_bridge_ops, + .policy = nft_reject_policy, + .maxattr = NFTA_REJECT_MAX, + .owner = THIS_MODULE, +}; + +static int __init nft_reject_bridge_module_init(void) +{ + return nft_register_expr(&nft_reject_bridge_type); +} + +static void __exit nft_reject_bridge_module_exit(void) +{ + nft_unregister_expr(&nft_reject_bridge_type); +} + +module_init(nft_reject_bridge_module_init); +module_exit(nft_reject_bridge_module_exit); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Pablo Neira Ayuso <pablo@netfilter.org>"); +MODULE_ALIAS_NFT_AF_EXPR(AF_BRIDGE, "reject"); +MODULE_DESCRIPTION("Reject packets from bridge via nftables"); |