| /* (C) 1999-2001 Paul `Rusty' Russell |
| * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/spinlock.h> |
| #include <linux/skbuff.h> |
| #include <linux/if_arp.h> |
| #include <linux/ip.h> |
| #include <net/ipv6.h> |
| #include <net/icmp.h> |
| #include <net/udp.h> |
| #include <net/tcp.h> |
| #include <net/route.h> |
| |
| #include <linux/netfilter.h> |
| #include <linux/netfilter/xt_LOG.h> |
| #include <net/netfilter/nf_log.h> |
| |
| static const struct nf_loginfo default_loginfo = { |
| .type = NF_LOG_TYPE_LOG, |
| .u = { |
| .log = { |
| .level = LOGLEVEL_NOTICE, |
| .logflags = NF_LOG_DEFAULT_MASK, |
| }, |
| }, |
| }; |
| |
| /* One level of recursion won't kill us */ |
| static void dump_ipv4_packet(struct net *net, struct nf_log_buf *m, |
| const struct nf_loginfo *info, |
| const struct sk_buff *skb, unsigned int iphoff) |
| { |
| struct iphdr _iph; |
| const struct iphdr *ih; |
| unsigned int logflags; |
| |
| if (info->type == NF_LOG_TYPE_LOG) |
| logflags = info->u.log.logflags; |
| else |
| logflags = NF_LOG_DEFAULT_MASK; |
| |
| ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); |
| if (ih == NULL) { |
| nf_log_buf_add(m, "TRUNCATED"); |
| return; |
| } |
| |
| /* Important fields: |
| * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */ |
| /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */ |
| nf_log_buf_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr); |
| |
| /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ |
| nf_log_buf_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", |
| ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, |
| ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); |
| |
| /* Max length: 6 "CE DF MF " */ |
| if (ntohs(ih->frag_off) & IP_CE) |
| nf_log_buf_add(m, "CE "); |
| if (ntohs(ih->frag_off) & IP_DF) |
| nf_log_buf_add(m, "DF "); |
| if (ntohs(ih->frag_off) & IP_MF) |
| nf_log_buf_add(m, "MF "); |
| |
| /* Max length: 11 "FRAG:65535 " */ |
| if (ntohs(ih->frag_off) & IP_OFFSET) |
| nf_log_buf_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); |
| |
| if ((logflags & NF_LOG_IPOPT) && |
| ih->ihl * 4 > sizeof(struct iphdr)) { |
| const unsigned char *op; |
| unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; |
| unsigned int i, optsize; |
| |
| optsize = ih->ihl * 4 - sizeof(struct iphdr); |
| op = skb_header_pointer(skb, iphoff+sizeof(_iph), |
| optsize, _opt); |
| if (op == NULL) { |
| nf_log_buf_add(m, "TRUNCATED"); |
| return; |
| } |
| |
| /* Max length: 127 "OPT (" 15*4*2chars ") " */ |
| nf_log_buf_add(m, "OPT ("); |
| for (i = 0; i < optsize; i++) |
| nf_log_buf_add(m, "%02X", op[i]); |
| nf_log_buf_add(m, ") "); |
| } |
| |
| switch (ih->protocol) { |
| case IPPROTO_TCP: |
| if (nf_log_dump_tcp_header(m, skb, ih->protocol, |
| ntohs(ih->frag_off) & IP_OFFSET, |
| iphoff+ih->ihl*4, logflags)) |
| return; |
| break; |
| case IPPROTO_UDP: |
| case IPPROTO_UDPLITE: |
| if (nf_log_dump_udp_header(m, skb, ih->protocol, |
| ntohs(ih->frag_off) & IP_OFFSET, |
| iphoff+ih->ihl*4)) |
| return; |
| break; |
| case IPPROTO_ICMP: { |
| struct icmphdr _icmph; |
| const struct icmphdr *ich; |
| static const size_t required_len[NR_ICMP_TYPES+1] |
| = { [ICMP_ECHOREPLY] = 4, |
| [ICMP_DEST_UNREACH] |
| = 8 + sizeof(struct iphdr), |
| [ICMP_SOURCE_QUENCH] |
| = 8 + sizeof(struct iphdr), |
| [ICMP_REDIRECT] |
| = 8 + sizeof(struct iphdr), |
| [ICMP_ECHO] = 4, |
| [ICMP_TIME_EXCEEDED] |
| = 8 + sizeof(struct iphdr), |
| [ICMP_PARAMETERPROB] |
| = 8 + sizeof(struct iphdr), |
| [ICMP_TIMESTAMP] = 20, |
| [ICMP_TIMESTAMPREPLY] = 20, |
| [ICMP_ADDRESS] = 12, |
| [ICMP_ADDRESSREPLY] = 12 }; |
| |
| /* Max length: 11 "PROTO=ICMP " */ |
| nf_log_buf_add(m, "PROTO=ICMP "); |
| |
| if (ntohs(ih->frag_off) & IP_OFFSET) |
| break; |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| ich = skb_header_pointer(skb, iphoff + ih->ihl * 4, |
| sizeof(_icmph), &_icmph); |
| if (ich == NULL) { |
| nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", |
| skb->len - iphoff - ih->ihl*4); |
| break; |
| } |
| |
| /* Max length: 18 "TYPE=255 CODE=255 " */ |
| nf_log_buf_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code); |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| if (ich->type <= NR_ICMP_TYPES && |
| required_len[ich->type] && |
| skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) { |
| nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", |
| skb->len - iphoff - ih->ihl*4); |
| break; |
| } |
| |
| switch (ich->type) { |
| case ICMP_ECHOREPLY: |
| case ICMP_ECHO: |
| /* Max length: 19 "ID=65535 SEQ=65535 " */ |
| nf_log_buf_add(m, "ID=%u SEQ=%u ", |
| ntohs(ich->un.echo.id), |
| ntohs(ich->un.echo.sequence)); |
| break; |
| |
| case ICMP_PARAMETERPROB: |
| /* Max length: 14 "PARAMETER=255 " */ |
| nf_log_buf_add(m, "PARAMETER=%u ", |
| ntohl(ich->un.gateway) >> 24); |
| break; |
| case ICMP_REDIRECT: |
| /* Max length: 24 "GATEWAY=255.255.255.255 " */ |
| nf_log_buf_add(m, "GATEWAY=%pI4 ", &ich->un.gateway); |
| /* Fall through */ |
| case ICMP_DEST_UNREACH: |
| case ICMP_SOURCE_QUENCH: |
| case ICMP_TIME_EXCEEDED: |
| /* Max length: 3+maxlen */ |
| if (!iphoff) { /* Only recurse once. */ |
| nf_log_buf_add(m, "["); |
| dump_ipv4_packet(net, m, info, skb, |
| iphoff + ih->ihl*4+sizeof(_icmph)); |
| nf_log_buf_add(m, "] "); |
| } |
| |
| /* Max length: 10 "MTU=65535 " */ |
| if (ich->type == ICMP_DEST_UNREACH && |
| ich->code == ICMP_FRAG_NEEDED) { |
| nf_log_buf_add(m, "MTU=%u ", |
| ntohs(ich->un.frag.mtu)); |
| } |
| } |
| break; |
| } |
| /* Max Length */ |
| case IPPROTO_AH: { |
| struct ip_auth_hdr _ahdr; |
| const struct ip_auth_hdr *ah; |
| |
| if (ntohs(ih->frag_off) & IP_OFFSET) |
| break; |
| |
| /* Max length: 9 "PROTO=AH " */ |
| nf_log_buf_add(m, "PROTO=AH "); |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| ah = skb_header_pointer(skb, iphoff+ih->ihl*4, |
| sizeof(_ahdr), &_ahdr); |
| if (ah == NULL) { |
| nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", |
| skb->len - iphoff - ih->ihl*4); |
| break; |
| } |
| |
| /* Length: 15 "SPI=0xF1234567 " */ |
| nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi)); |
| break; |
| } |
| case IPPROTO_ESP: { |
| struct ip_esp_hdr _esph; |
| const struct ip_esp_hdr *eh; |
| |
| /* Max length: 10 "PROTO=ESP " */ |
| nf_log_buf_add(m, "PROTO=ESP "); |
| |
| if (ntohs(ih->frag_off) & IP_OFFSET) |
| break; |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| eh = skb_header_pointer(skb, iphoff+ih->ihl*4, |
| sizeof(_esph), &_esph); |
| if (eh == NULL) { |
| nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", |
| skb->len - iphoff - ih->ihl*4); |
| break; |
| } |
| |
| /* Length: 15 "SPI=0xF1234567 " */ |
| nf_log_buf_add(m, "SPI=0x%x ", ntohl(eh->spi)); |
| break; |
| } |
| /* Max length: 10 "PROTO 255 " */ |
| default: |
| nf_log_buf_add(m, "PROTO=%u ", ih->protocol); |
| } |
| |
| /* Max length: 15 "UID=4294967295 " */ |
| if ((logflags & NF_LOG_UID) && !iphoff) |
| nf_log_dump_sk_uid_gid(net, m, skb->sk); |
| |
| /* Max length: 16 "MARK=0xFFFFFFFF " */ |
| if (!iphoff && skb->mark) |
| nf_log_buf_add(m, "MARK=0x%x ", skb->mark); |
| |
| /* Proto Max log string length */ |
| /* IP: 40+46+6+11+127 = 230 */ |
| /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */ |
| /* UDP: 10+max(25,20) = 35 */ |
| /* UDPLITE: 14+max(25,20) = 39 */ |
| /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */ |
| /* ESP: 10+max(25)+15 = 50 */ |
| /* AH: 9+max(25)+15 = 49 */ |
| /* unknown: 10 */ |
| |
| /* (ICMP allows recursion one level deep) */ |
| /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */ |
| /* maxlen = 230+ 91 + 230 + 252 = 803 */ |
| } |
| |
| static void dump_ipv4_mac_header(struct nf_log_buf *m, |
| const struct nf_loginfo *info, |
| const struct sk_buff *skb) |
| { |
| struct net_device *dev = skb->dev; |
| unsigned int logflags = 0; |
| |
| if (info->type == NF_LOG_TYPE_LOG) |
| logflags = info->u.log.logflags; |
| |
| if (!(logflags & NF_LOG_MACDECODE)) |
| goto fallback; |
| |
| switch (dev->type) { |
| case ARPHRD_ETHER: |
| nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", |
| eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, |
| ntohs(eth_hdr(skb)->h_proto)); |
| return; |
| default: |
| break; |
| } |
| |
| fallback: |
| nf_log_buf_add(m, "MAC="); |
| if (dev->hard_header_len && |
| skb->mac_header != skb->network_header) { |
| const unsigned char *p = skb_mac_header(skb); |
| unsigned int i; |
| |
| nf_log_buf_add(m, "%02x", *p++); |
| for (i = 1; i < dev->hard_header_len; i++, p++) |
| nf_log_buf_add(m, ":%02x", *p); |
| } |
| nf_log_buf_add(m, " "); |
| } |
| |
| static void nf_log_ip_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) |
| { |
| struct nf_log_buf *m; |
| |
| /* FIXME: Disabled from containers until syslog ns is supported */ |
| if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns) |
| return; |
| |
| m = nf_log_buf_open(); |
| |
| if (!loginfo) |
| loginfo = &default_loginfo; |
| |
| nf_log_dump_packet_common(m, pf, hooknum, skb, in, |
| out, loginfo, prefix); |
| |
| if (in != NULL) |
| dump_ipv4_mac_header(m, loginfo, skb); |
| |
| dump_ipv4_packet(net, m, loginfo, skb, 0); |
| |
| nf_log_buf_close(m); |
| } |
| |
| static struct nf_logger nf_ip_logger __read_mostly = { |
| .name = "nf_log_ipv4", |
| .type = NF_LOG_TYPE_LOG, |
| .logfn = nf_log_ip_packet, |
| .me = THIS_MODULE, |
| }; |
| |
| static int __net_init nf_log_ipv4_net_init(struct net *net) |
| { |
| return nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger); |
| } |
| |
| static void __net_exit nf_log_ipv4_net_exit(struct net *net) |
| { |
| nf_log_unset(net, &nf_ip_logger); |
| } |
| |
| static struct pernet_operations nf_log_ipv4_net_ops = { |
| .init = nf_log_ipv4_net_init, |
| .exit = nf_log_ipv4_net_exit, |
| }; |
| |
| static int __init nf_log_ipv4_init(void) |
| { |
| int ret; |
| |
| ret = register_pernet_subsys(&nf_log_ipv4_net_ops); |
| if (ret < 0) |
| return ret; |
| |
| ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger); |
| if (ret < 0) { |
| pr_err("failed to register logger\n"); |
| goto err1; |
| } |
| |
| return 0; |
| |
| err1: |
| unregister_pernet_subsys(&nf_log_ipv4_net_ops); |
| return ret; |
| } |
| |
| static void __exit nf_log_ipv4_exit(void) |
| { |
| unregister_pernet_subsys(&nf_log_ipv4_net_ops); |
| nf_log_unregister(&nf_ip_logger); |
| } |
| |
| module_init(nf_log_ipv4_init); |
| module_exit(nf_log_ipv4_exit); |
| |
| MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>"); |
| MODULE_DESCRIPTION("Netfilter IPv4 packet logging"); |
| MODULE_LICENSE("GPL"); |
| MODULE_ALIAS_NF_LOGGER(AF_INET, 0); |