diff options
Diffstat (limited to 'net/ipv4/netfilter/nf_log_ipv4.c')
-rw-r--r-- | net/ipv4/netfilter/nf_log_ipv4.c | 385 |
1 files changed, 385 insertions, 0 deletions
diff --git a/net/ipv4/netfilter/nf_log_ipv4.c b/net/ipv4/netfilter/nf_log_ipv4.c new file mode 100644 index 0000000..078bdca --- /dev/null +++ b/net/ipv4/netfilter/nf_log_ipv4.c @@ -0,0 +1,385 @@ +/* (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. + */ + +#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 struct nf_loginfo default_loginfo = { + .type = NF_LOG_TYPE_LOG, + .u = { + .log = { + .level = 5, + .logflags = NF_LOG_MASK, + }, + }, +}; + +/* One level of recursion won't kill us */ +static void dump_ipv4_packet(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_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 & XT_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(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 & XT_LOG_UID) && !iphoff) + nf_log_dump_sk_uid_gid(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 & XT_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)) + 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(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) +{ + nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger); + return 0; +} + +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; + + nf_log_register(NFPROTO_IPV4, &nf_ip_logger); + return 0; +} + +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); |