/* * This is a module which is used for logging packets. */ /* (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/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/x_tables.h>#include <linux/netfilter/xt_LOG.h>#include <linux/netfilter_ipv6/ip6_tables.h>#include <net/netfilter/nf_log.h>#include <net/netfilter/xt_log.h> static struct nf_loginfo default_loginfo = { .type = NF_LOG_TYPE_LOG, .u = { .log = { .level = 5, .logflags = NF_LOG_MASK, }, },}; static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb, u8 proto, int fragment, unsigned int offset){ struct udphdr _udph; const struct udphdr *uh; if (proto == IPPROTO_UDP) /* Max length: 10 "PROTO=UDP " */ sb_add(m, "PROTO=UDP "); else /* Max length: 14 "PROTO=UDPLITE " */ sb_add(m, "PROTO=UDPLITE "); if (fragment) goto out; /* Max length: 25 "INCOMPLETE [65535 bytes] " */ uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); if (uh == NULL) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); return 1; } /* Max length: 20 "SPT=65535 DPT=65535 " */ sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest), ntohs(uh->len)); out: return 0;} static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb, u8 proto, int fragment, unsigned int offset, unsigned int logflags){ struct tcphdr _tcph; const struct tcphdr *th; /* Max length: 10 "PROTO=TCP " */ sb_add(m, "PROTO=TCP "); if (fragment) return 0; /* Max length: 25 "INCOMPLETE [65535 bytes] " */ th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); if (th == NULL) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); return 1; } /* Max length: 20 "SPT=65535 DPT=65535 " */ sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest)); /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ if (logflags & XT_LOG_TCPSEQ) sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq)); /* Max length: 13 "WINDOW=65535 " */ sb_add(m, "WINDOW=%u ", ntohs(th->window)); /* Max length: 9 "RES=0x3C " */ sb_add(m, "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) sb_add(m, "CWR "); if (th->ece) sb_add(m, "ECE "); if (th->urg) sb_add(m, "URG "); if (th->ack) sb_add(m, "ACK "); if (th->psh) sb_add(m, "PSH "); if (th->rst) sb_add(m, "RST "); if (th->syn) sb_add(m, "SYN "); if (th->fin) sb_add(m, "FIN "); /* Max length: 11 "URGP=65535 " */ sb_add(m, "URGP=%u ", ntohs(th->urg_ptr)); if ((logflags & XT_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, offset + sizeof(struct tcphdr), optsize, _opt); if (op == NULL) { sb_add(m, "OPT (TRUNCATED)"); return 1; } /* Max length: 127 "OPT (" 15*4*2chars ") " */ sb_add(m, "OPT ("); for (i = 0; i < optsize; i++) sb_add(m, "%02X", op[i]); sb_add(m, ") "); } return 0;} static void dump_sk_uid_gid(struct sbuff *m, struct sock *sk){ if (!sk || sk->sk_state == TCP_TIME_WAIT) return; read_lock_bh(&sk->sk_callback_lock); if (sk->sk_socket && sk->sk_socket->file) { const struct cred *cred = sk->sk_socket->file->f_cred; sb_add(m, "UID=%u GID=%u ", from_kuid_munged(&init_user_ns, cred->fsuid), from_kgid_munged(&init_user_ns, cred->fsgid)); } read_unlock_bh(&sk->sk_callback_lock);} /* One level of recursion won't kill us */static void dump_ipv4_packet(struct sbuff *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) { sb_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 " */ sb_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr); /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ sb_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) sb_add(m, "CE "); if (ntohs(ih->frag_off) & IP_DF) sb_add(m, "DF "); if (ntohs(ih->frag_off) & IP_MF) sb_add(m, "MF "); /* Max length: 11 "FRAG:65535 " */ if (ntohs(ih->frag_off) & IP_OFFSET) sb_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) { sb_add(m, "TRUNCATED"); return; } /* Max length: 127 "OPT (" 15*4*2chars ") " */ sb_add(m, "OPT ("); for (i = 0; i < optsize; i++) sb_add(m, "%02X", op[i]); sb_add(m, ") "); } switch (ih->protocol) { case IPPROTO_TCP: if (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 (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 " */ sb_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) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - iphoff - ih->ihl*4); break; } /* Max length: 18 "TYPE=255 CODE=255 " */ sb_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]) { sb_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 " */ sb_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 " */ sb_add(m, "PARAMETER=%u ", ntohl(ich->un.gateway) >> 24); break; case ICMP_REDIRECT: /* Max length: 24 "GATEWAY=255.255.255.255 " */ sb_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. */ sb_add(m, "["); dump_ipv4_packet(m, info, skb, iphoff + ih->ihl*4+sizeof(_icmph)); sb_add(m, "] "); } /* Max length: 10 "MTU=65535 " */ if (ich->type == ICMP_DEST_UNREACH && ich->code == ICMP_FRAG_NEEDED) sb_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 " */ sb_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) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - iphoff - ih->ihl*4); break; } /* Length: 15 "SPI=0xF1234567 " */ sb_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 " */ sb_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) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - iphoff - ih->ihl*4); break; } /* Length: 15 "SPI=0xF1234567 " */ sb_add(m, "SPI=0x%x ", ntohl(eh->spi)); break; } /* Max length: 10 "PROTO 255 " */ default: sb_add(m, "PROTO=%u ", ih->protocol); } /* Max length: 15 "UID=4294967295 " */ if ((logflags & XT_LOG_UID) && !iphoff) dump_sk_uid_gid(m, skb->sk); /* Max length: 16 "MARK=0xFFFFFFFF " */ if (!iphoff && skb->mark) sb_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 sbuff *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: sb_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: sb_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; sb_add(m, "%02x", *p++); for (i = 1; i < dev->hard_header_len; i++, p++) sb_add(m, ":%02x", *p); } sb_add(m, " ");} static voidlog_packet_common(struct sbuff *m, 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){ sb_add(m, KERN_SOH "%c%sIN=%s OUT=%s ", '0' + loginfo->u.log.level, prefix, in ? in->name : "", out ? out->name : "");#ifdef CONFIG_BRIDGE_NETFILTER if (skb->nf_bridge) { const struct net_device *physindev; const struct net_device *physoutdev; physindev = skb->nf_bridge->physindev; if (physindev && in != physindev) sb_add(m, "PHYSIN=%s ", physindev->name); physoutdev = skb->nf_bridge->physoutdev; if (physoutdev && out != physoutdev) sb_add(m, "PHYSOUT=%s ", physoutdev->name); }#endif} static voidipt_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){ struct sbuff *m; /* FIXME: Disabled from containers until syslog ns is supported */ if (!net_eq(net, &init_net)) return; m = sb_open(); if (!loginfo) loginfo = &default_loginfo; log_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); sb_close(m);} #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES)/* One level of recursion won't kill us */Lines 1–500 of 975. 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/* * This is a module which is used for logging packets. */ /* (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/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/x_tables.h> #include <linux/netfilter/xt_LOG.h> #include <linux/netfilter_ipv6/ip6_tables.h> #include <net/netfilter/nf_log.h> #include <net/netfilter/xt_log.h> static struct nf_loginfo default_loginfo = { .type = NF_LOG_TYPE_LOG, .u = { .log = { .level = 5, .logflags = NF_LOG_MASK, }, }, }; static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb, u8 proto, int fragment, unsigned int offset) { struct udphdr _udph; const struct udphdr *uh; if (proto == IPPROTO_UDP) /* Max length: 10 "PROTO=UDP " */ sb_add(m, "PROTO=UDP "); else /* Max length: 14 "PROTO=UDPLITE " */ sb_add(m, "PROTO=UDPLITE "); if (fragment) goto out; /* Max length: 25 "INCOMPLETE [65535 bytes] " */ uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); if (uh == NULL) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); return 1; } /* Max length: 20 "SPT=65535 DPT=65535 " */ sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest), ntohs(uh->len)); out: return 0; } static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb, u8 proto, int fragment, unsigned int offset, unsigned int logflags) { struct tcphdr _tcph; const struct tcphdr *th; /* Max length: 10 "PROTO=TCP " */ sb_add(m, "PROTO=TCP "); if (fragment) return 0; /* Max length: 25 "INCOMPLETE [65535 bytes] " */ th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); if (th == NULL) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); return 1; } /* Max length: 20 "SPT=65535 DPT=65535 " */ sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest)); /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ if (logflags & XT_LOG_TCPSEQ) sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq)); /* Max length: 13 "WINDOW=65535 " */ sb_add(m, "WINDOW=%u ", ntohs(th->window)); /* Max length: 9 "RES=0x3C " */ sb_add(m, "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) sb_add(m, "CWR "); if (th->ece) sb_add(m, "ECE "); if (th->urg) sb_add(m, "URG "); if (th->ack) sb_add(m, "ACK "); if (th->psh) sb_add(m, "PSH "); if (th->rst) sb_add(m, "RST "); if (th->syn) sb_add(m, "SYN "); if (th->fin) sb_add(m, "FIN "); /* Max length: 11 "URGP=65535 " */ sb_add(m, "URGP=%u ", ntohs(th->urg_ptr)); if ((logflags & XT_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, offset + sizeof(struct tcphdr), optsize, _opt); if (op == NULL) { sb_add(m, "OPT (TRUNCATED)"); return 1; } /* Max length: 127 "OPT (" 15*4*2chars ") " */ sb_add(m, "OPT ("); for (i = 0; i < optsize; i++) sb_add(m, "%02X", op[i]); sb_add(m, ") "); } return 0; } static void dump_sk_uid_gid(struct sbuff *m, struct sock *sk) { if (!sk || sk->sk_state == TCP_TIME_WAIT) return; read_lock_bh(&sk->sk_callback_lock); if (sk->sk_socket && sk->sk_socket->file) { const struct cred *cred = sk->sk_socket->file->f_cred; sb_add(m, "UID=%u GID=%u ", from_kuid_munged(&init_user_ns, cred->fsuid), from_kgid_munged(&init_user_ns, cred->fsgid)); } read_unlock_bh(&sk->sk_callback_lock); } /* One level of recursion won't kill us */ static void dump_ipv4_packet(struct sbuff *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) { sb_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 " */ sb_add(m, "SRC=%pI4 DST=%pI4 ", &ih->saddr, &ih->daddr); /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ sb_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) sb_add(m, "CE "); if (ntohs(ih->frag_off) & IP_DF) sb_add(m, "DF "); if (ntohs(ih->frag_off) & IP_MF) sb_add(m, "MF "); /* Max length: 11 "FRAG:65535 " */ if (ntohs(ih->frag_off) & IP_OFFSET) sb_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) { sb_add(m, "TRUNCATED"); return; } /* Max length: 127 "OPT (" 15*4*2chars ") " */ sb_add(m, "OPT ("); for (i = 0; i < optsize; i++) sb_add(m, "%02X", op[i]); sb_add(m, ") "); } switch (ih->protocol) { case IPPROTO_TCP: if (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 (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 " */ sb_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) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - iphoff - ih->ihl*4); break; } /* Max length: 18 "TYPE=255 CODE=255 " */ sb_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]) { sb_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 " */ sb_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 " */ sb_add(m, "PARAMETER=%u ", ntohl(ich->un.gateway) >> 24); break; case ICMP_REDIRECT: /* Max length: 24 "GATEWAY=255.255.255.255 " */ sb_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. */ sb_add(m, "["); dump_ipv4_packet(m, info, skb, iphoff + ih->ihl*4+sizeof(_icmph)); sb_add(m, "] "); } /* Max length: 10 "MTU=65535 " */ if (ich->type == ICMP_DEST_UNREACH && ich->code == ICMP_FRAG_NEEDED) sb_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 " */ sb_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) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - iphoff - ih->ihl*4); break; } /* Length: 15 "SPI=0xF1234567 " */ sb_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 " */ sb_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) { sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - iphoff - ih->ihl*4); break; } /* Length: 15 "SPI=0xF1234567 " */ sb_add(m, "SPI=0x%x ", ntohl(eh->spi)); break; } /* Max length: 10 "PROTO 255 " */ default: sb_add(m, "PROTO=%u ", ih->protocol); } /* Max length: 15 "UID=4294967295 " */ if ((logflags & XT_LOG_UID) && !iphoff) dump_sk_uid_gid(m, skb->sk); /* Max length: 16 "MARK=0xFFFFFFFF " */ if (!iphoff && skb->mark) sb_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 sbuff *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: sb_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: sb_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; sb_add(m, "%02x", *p++); for (i = 1; i < dev->hard_header_len; i++, p++) sb_add(m, ":%02x", *p); } sb_add(m, " "); } static void log_packet_common(struct sbuff *m, 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) { sb_add(m, KERN_SOH "%c%sIN=%s OUT=%s ", '0' + loginfo->u.log.level, prefix, in ? in->name : "", out ? out->name : ""); #ifdef CONFIG_BRIDGE_NETFILTER if (skb->nf_bridge) { const struct net_device *physindev; const struct net_device *physoutdev; physindev = skb->nf_bridge->physindev; if (physindev && in != physindev) sb_add(m, "PHYSIN=%s ", physindev->name); physoutdev = skb->nf_bridge->physoutdev; if (physoutdev && out != physoutdev) sb_add(m, "PHYSOUT=%s ", physoutdev->name); } #endif } static void ipt_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) { struct sbuff *m; /* FIXME: Disabled from containers until syslog ns is supported */ if (!net_eq(net, &init_net)) return; m = sb_open(); if (!loginfo) loginfo = &default_loginfo; log_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); sb_close(m); } #if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) /* One level of recursion won't kill us */