diff options
Diffstat (limited to 'net/bridge/netfilter/ebt_log.c')
| -rw-r--r-- | net/bridge/netfilter/ebt_log.c | 226 |
1 files changed, 226 insertions, 0 deletions
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"); |