| /* |
| * This is a module which is used for logging packets. |
| */ |
| |
| /* (C) 2001 Jan Rekorajski <baggins@pld.org.pl> |
| * (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/module.h> |
| #include <linux/skbuff.h> |
| #include <linux/if_arp.h> |
| #include <linux/ip.h> |
| #include <linux/spinlock.h> |
| #include <linux/icmpv6.h> |
| #include <net/udp.h> |
| #include <net/tcp.h> |
| #include <net/ipv6.h> |
| #include <linux/netfilter.h> |
| #include <linux/netfilter/x_tables.h> |
| #include <linux/netfilter_ipv6/ip6_tables.h> |
| #include <net/netfilter/nf_log.h> |
| |
| MODULE_AUTHOR("Jan Rekorajski <baggins@pld.org.pl>"); |
| MODULE_DESCRIPTION("Xtables: IPv6 packet logging to syslog"); |
| MODULE_LICENSE("GPL"); |
| |
| struct in_device; |
| #include <net/route.h> |
| #include <linux/netfilter_ipv6/ip6t_LOG.h> |
| |
| /* Use lock to serialize, so printks don't overlap */ |
| static DEFINE_SPINLOCK(log_lock); |
| |
| /* One level of recursion won't kill us */ |
| static void dump_packet(const struct nf_loginfo *info, |
| const struct sk_buff *skb, unsigned int ip6hoff, |
| int recurse) |
| { |
| u_int8_t currenthdr; |
| int fragment; |
| struct ipv6hdr _ip6h; |
| const struct ipv6hdr *ih; |
| unsigned int ptr; |
| unsigned int hdrlen = 0; |
| 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, ip6hoff, sizeof(_ip6h), &_ip6h); |
| if (ih == NULL) { |
| printk("TRUNCATED"); |
| return; |
| } |
| |
| /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */ |
| printk("SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr); |
| |
| /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ |
| printk("LEN=%Zu TC=%u HOPLIMIT=%u FLOWLBL=%u ", |
| ntohs(ih->payload_len) + sizeof(struct ipv6hdr), |
| (ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20, |
| ih->hop_limit, |
| (ntohl(*(__be32 *)ih) & 0x000fffff)); |
| |
| fragment = 0; |
| ptr = ip6hoff + sizeof(struct ipv6hdr); |
| currenthdr = ih->nexthdr; |
| while (currenthdr != NEXTHDR_NONE && ip6t_ext_hdr(currenthdr)) { |
| struct ipv6_opt_hdr _hdr; |
| const struct ipv6_opt_hdr *hp; |
| |
| hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr); |
| if (hp == NULL) { |
| printk("TRUNCATED"); |
| return; |
| } |
| |
| /* Max length: 48 "OPT (...) " */ |
| if (logflags & IP6T_LOG_IPOPT) |
| printk("OPT ( "); |
| |
| switch (currenthdr) { |
| case IPPROTO_FRAGMENT: { |
| struct frag_hdr _fhdr; |
| const struct frag_hdr *fh; |
| |
| printk("FRAG:"); |
| fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), |
| &_fhdr); |
| if (fh == NULL) { |
| printk("TRUNCATED "); |
| return; |
| } |
| |
| /* Max length: 6 "65535 " */ |
| printk("%u ", ntohs(fh->frag_off) & 0xFFF8); |
| |
| /* Max length: 11 "INCOMPLETE " */ |
| if (fh->frag_off & htons(0x0001)) |
| printk("INCOMPLETE "); |
| |
| printk("ID:%08x ", ntohl(fh->identification)); |
| |
| if (ntohs(fh->frag_off) & 0xFFF8) |
| fragment = 1; |
| |
| hdrlen = 8; |
| |
| break; |
| } |
| case IPPROTO_DSTOPTS: |
| case IPPROTO_ROUTING: |
| case IPPROTO_HOPOPTS: |
| if (fragment) { |
| if (logflags & IP6T_LOG_IPOPT) |
| printk(")"); |
| return; |
| } |
| hdrlen = ipv6_optlen(hp); |
| break; |
| /* Max Length */ |
| case IPPROTO_AH: |
| if (logflags & IP6T_LOG_IPOPT) { |
| struct ip_auth_hdr _ahdr; |
| const struct ip_auth_hdr *ah; |
| |
| /* Max length: 3 "AH " */ |
| printk("AH "); |
| |
| if (fragment) { |
| printk(")"); |
| return; |
| } |
| |
| ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), |
| &_ahdr); |
| if (ah == NULL) { |
| /* |
| * Max length: 26 "INCOMPLETE [65535 |
| * bytes] )" |
| */ |
| printk("INCOMPLETE [%u bytes] )", |
| skb->len - ptr); |
| return; |
| } |
| |
| /* Length: 15 "SPI=0xF1234567 */ |
| printk("SPI=0x%x ", ntohl(ah->spi)); |
| |
| } |
| |
| hdrlen = (hp->hdrlen+2)<<2; |
| break; |
| case IPPROTO_ESP: |
| if (logflags & IP6T_LOG_IPOPT) { |
| struct ip_esp_hdr _esph; |
| const struct ip_esp_hdr *eh; |
| |
| /* Max length: 4 "ESP " */ |
| printk("ESP "); |
| |
| if (fragment) { |
| printk(")"); |
| return; |
| } |
| |
| /* |
| * Max length: 26 "INCOMPLETE [65535 bytes] )" |
| */ |
| eh = skb_header_pointer(skb, ptr, sizeof(_esph), |
| &_esph); |
| if (eh == NULL) { |
| printk("INCOMPLETE [%u bytes] )", |
| skb->len - ptr); |
| return; |
| } |
| |
| /* Length: 16 "SPI=0xF1234567 )" */ |
| printk("SPI=0x%x )", ntohl(eh->spi) ); |
| |
| } |
| return; |
| default: |
| /* Max length: 20 "Unknown Ext Hdr 255" */ |
| printk("Unknown Ext Hdr %u", currenthdr); |
| return; |
| } |
| if (logflags & IP6T_LOG_IPOPT) |
| printk(") "); |
| |
| currenthdr = hp->nexthdr; |
| ptr += hdrlen; |
| } |
| |
| switch (currenthdr) { |
| case IPPROTO_TCP: { |
| struct tcphdr _tcph; |
| const struct tcphdr *th; |
| |
| /* Max length: 10 "PROTO=TCP " */ |
| printk("PROTO=TCP "); |
| |
| if (fragment) |
| break; |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| th = skb_header_pointer(skb, ptr, sizeof(_tcph), &_tcph); |
| if (th == NULL) { |
| printk("INCOMPLETE [%u bytes] ", skb->len - ptr); |
| return; |
| } |
| |
| /* Max length: 20 "SPT=65535 DPT=65535 " */ |
| printk("SPT=%u DPT=%u ", |
| ntohs(th->source), ntohs(th->dest)); |
| /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ |
| if (logflags & IP6T_LOG_TCPSEQ) |
| printk("SEQ=%u ACK=%u ", |
| ntohl(th->seq), ntohl(th->ack_seq)); |
| /* Max length: 13 "WINDOW=65535 " */ |
| printk("WINDOW=%u ", ntohs(th->window)); |
| /* Max length: 9 "RES=0x3C " */ |
| printk("RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & TCP_RESERVED_BITS) >> 22)); |
| /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */ |
| if (th->cwr) |
| printk("CWR "); |
| if (th->ece) |
| printk("ECE "); |
| if (th->urg) |
| printk("URG "); |
| if (th->ack) |
| printk("ACK "); |
| if (th->psh) |
| printk("PSH "); |
| if (th->rst) |
| printk("RST "); |
| if (th->syn) |
| printk("SYN "); |
| if (th->fin) |
| printk("FIN "); |
| /* Max length: 11 "URGP=65535 " */ |
| printk("URGP=%u ", ntohs(th->urg_ptr)); |
| |
| if ((logflags & IP6T_LOG_TCPOPT) && |
| th->doff * 4 > sizeof(struct tcphdr)) { |
| u_int8_t _opt[60 - sizeof(struct tcphdr)]; |
| const u_int8_t *op; |
| unsigned int i; |
| unsigned int optsize = th->doff * 4 |
| - sizeof(struct tcphdr); |
| |
| op = skb_header_pointer(skb, |
| ptr + sizeof(struct tcphdr), |
| optsize, _opt); |
| if (op == NULL) { |
| printk("OPT (TRUNCATED)"); |
| return; |
| } |
| |
| /* Max length: 127 "OPT (" 15*4*2chars ") " */ |
| printk("OPT ("); |
| for (i =0; i < optsize; i++) |
| printk("%02X", op[i]); |
| printk(") "); |
| } |
| break; |
| } |
| case IPPROTO_UDP: |
| case IPPROTO_UDPLITE: { |
| struct udphdr _udph; |
| const struct udphdr *uh; |
| |
| if (currenthdr == IPPROTO_UDP) |
| /* Max length: 10 "PROTO=UDP " */ |
| printk("PROTO=UDP " ); |
| else /* Max length: 14 "PROTO=UDPLITE " */ |
| printk("PROTO=UDPLITE "); |
| |
| if (fragment) |
| break; |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| uh = skb_header_pointer(skb, ptr, sizeof(_udph), &_udph); |
| if (uh == NULL) { |
| printk("INCOMPLETE [%u bytes] ", skb->len - ptr); |
| return; |
| } |
| |
| /* Max length: 20 "SPT=65535 DPT=65535 " */ |
| printk("SPT=%u DPT=%u LEN=%u ", |
| ntohs(uh->source), ntohs(uh->dest), |
| ntohs(uh->len)); |
| break; |
| } |
| case IPPROTO_ICMPV6: { |
| struct icmp6hdr _icmp6h; |
| const struct icmp6hdr *ic; |
| |
| /* Max length: 13 "PROTO=ICMPv6 " */ |
| printk("PROTO=ICMPv6 "); |
| |
| if (fragment) |
| break; |
| |
| /* Max length: 25 "INCOMPLETE [65535 bytes] " */ |
| ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h); |
| if (ic == NULL) { |
| printk("INCOMPLETE [%u bytes] ", skb->len - ptr); |
| return; |
| } |
| |
| /* Max length: 18 "TYPE=255 CODE=255 " */ |
| printk("TYPE=%u CODE=%u ", ic->icmp6_type, ic->icmp6_code); |
| |
| switch (ic->icmp6_type) { |
| case ICMPV6_ECHO_REQUEST: |
| case ICMPV6_ECHO_REPLY: |
| /* Max length: 19 "ID=65535 SEQ=65535 " */ |
| printk("ID=%u SEQ=%u ", |
| ntohs(ic->icmp6_identifier), |
| ntohs(ic->icmp6_sequence)); |
| break; |
| case ICMPV6_MGM_QUERY: |
| case ICMPV6_MGM_REPORT: |
| case ICMPV6_MGM_REDUCTION: |
| break; |
| |
| case ICMPV6_PARAMPROB: |
| /* Max length: 17 "POINTER=ffffffff " */ |
| printk("POINTER=%08x ", ntohl(ic->icmp6_pointer)); |
| /* Fall through */ |
| case ICMPV6_DEST_UNREACH: |
| case ICMPV6_PKT_TOOBIG: |
| case ICMPV6_TIME_EXCEED: |
| /* Max length: 3+maxlen */ |
| if (recurse) { |
| printk("["); |
| dump_packet(info, skb, ptr + sizeof(_icmp6h), |
| 0); |
| printk("] "); |
| } |
| |
| /* Max length: 10 "MTU=65535 " */ |
| if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) |
| printk("MTU=%u ", ntohl(ic->icmp6_mtu)); |
| } |
| break; |
| } |
| /* Max length: 10 "PROTO=255 " */ |
| default: |
| printk("PROTO=%u ", currenthdr); |
| } |
| |
| /* Max length: 15 "UID=4294967295 " */ |
| if ((logflags & IP6T_LOG_UID) && recurse && skb->sk) { |
| read_lock_bh(&skb->sk->sk_callback_lock); |
| if (skb->sk->sk_socket && skb->sk->sk_socket->file) |
| printk("UID=%u GID=%u ", |
| skb->sk->sk_socket->file->f_cred->fsuid, |
| skb->sk->sk_socket->file->f_cred->fsgid); |
| read_unlock_bh(&skb->sk->sk_callback_lock); |
| } |
| |
| /* Max length: 16 "MARK=0xFFFFFFFF " */ |
| if (!recurse && skb->mark) |
| printk("MARK=0x%x ", skb->mark); |
| } |
| |
| static struct nf_loginfo default_loginfo = { |
| .type = NF_LOG_TYPE_LOG, |
| .u = { |
| .log = { |
| .level = 0, |
| .logflags = NF_LOG_MASK, |
| }, |
| }, |
| }; |
| |
| static void |
| ip6t_log_packet(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) |
| { |
| if (!loginfo) |
| loginfo = &default_loginfo; |
| |
| spin_lock_bh(&log_lock); |
| printk("<%d>%sIN=%s OUT=%s ", loginfo->u.log.level, |
| prefix, |
| in ? in->name : "", |
| out ? out->name : ""); |
| if (in && !out) { |
| unsigned int len; |
| /* MAC logging for input chain only. */ |
| printk("MAC="); |
| if (skb->dev && (len = skb->dev->hard_header_len) && |
| skb->mac_header != skb->network_header) { |
| const unsigned char *p = skb_mac_header(skb); |
| int i; |
| |
| if (skb->dev->type == ARPHRD_SIT && |
| (p -= ETH_HLEN) < skb->head) |
| p = NULL; |
| |
| if (p != NULL) { |
| for (i = 0; i < len; i++) |
| printk("%02x%s", p[i], |
| i == len - 1 ? "" : ":"); |
| } |
| printk(" "); |
| |
| if (skb->dev->type == ARPHRD_SIT) { |
| const struct iphdr *iph = |
| (struct iphdr *)skb_mac_header(skb); |
| printk("TUNNEL=%pI4->%pI4 ", |
| &iph->saddr, &iph->daddr); |
| } |
| } else |
| printk(" "); |
| } |
| |
| dump_packet(loginfo, skb, skb_network_offset(skb), 1); |
| printk("\n"); |
| spin_unlock_bh(&log_lock); |
| } |
| |
| static unsigned int |
| log_tg6(struct sk_buff *skb, const struct xt_target_param *par) |
| { |
| const struct ip6t_log_info *loginfo = par->targinfo; |
| struct nf_loginfo li; |
| |
| li.type = NF_LOG_TYPE_LOG; |
| li.u.log.level = loginfo->level; |
| li.u.log.logflags = loginfo->logflags; |
| |
| ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, par->out, |
| &li, loginfo->prefix); |
| return XT_CONTINUE; |
| } |
| |
| |
| static int log_tg6_check(const struct xt_tgchk_param *par) |
| { |
| const struct ip6t_log_info *loginfo = par->targinfo; |
| |
| if (loginfo->level >= 8) { |
| pr_debug("level %u >= 8\n", loginfo->level); |
| return false; |
| } |
| if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') { |
| pr_debug("prefix not null-terminated\n"); |
| return false; |
| } |
| return true; |
| } |
| |
| static struct xt_target log_tg6_reg __read_mostly = { |
| .name = "LOG", |
| .family = NFPROTO_IPV6, |
| .target = log_tg6, |
| .targetsize = sizeof(struct ip6t_log_info), |
| .checkentry = log_tg6_check, |
| .me = THIS_MODULE, |
| }; |
| |
| static struct nf_logger ip6t_logger __read_mostly = { |
| .name = "ip6t_LOG", |
| .logfn = &ip6t_log_packet, |
| .me = THIS_MODULE, |
| }; |
| |
| static int __init log_tg6_init(void) |
| { |
| int ret; |
| |
| ret = xt_register_target(&log_tg6_reg); |
| if (ret < 0) |
| return ret; |
| nf_log_register(NFPROTO_IPV6, &ip6t_logger); |
| return 0; |
| } |
| |
| static void __exit log_tg6_exit(void) |
| { |
| nf_log_unregister(&ip6t_logger); |
| xt_unregister_target(&log_tg6_reg); |
| } |
| |
| module_init(log_tg6_init); |
| module_exit(log_tg6_exit); |