int nf_log_dump_udp_header(struct nf_log_buf *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 " */ nf_log_buf_add(m, "PROTO=UDP "); else /* Max length: 14 "PROTO=UDPLITE " */ nf_log_buf_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) { nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); return 1; } /* Max length: 20 "SPT=65535 DPT=65535 " */ nf_log_buf_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest), ntohs(uh->len)); out: return 0; }
static void dump_arp_packet(struct nf_log_buf *m, const struct nf_loginfo *info, const struct sk_buff *skb, unsigned int nhoff) { const struct arphdr *ah; struct arphdr _arph; const struct arppayload *ap; struct arppayload _arpp; ah = skb_header_pointer(skb, 0, sizeof(_arph), &_arph); if (ah == NULL) { nf_log_buf_add(m, "TRUNCATED"); return; } nf_log_buf_add(m, "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)) return; ap = skb_header_pointer(skb, sizeof(_arph), sizeof(_arpp), &_arpp); if (ap == NULL) { nf_log_buf_add(m, " INCOMPLETE [%Zu bytes]", skb->len - sizeof(_arph)); return; } nf_log_buf_add(m, " MACSRC=%pM IPSRC=%pI4 MACDST=%pM IPDST=%pI4", ap->mac_src, ap->ip_src, ap->mac_dst, ap->ip_dst); }
void nf_log_dump_packet_common(struct nf_log_buf *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) { nf_log_buf_add(m, KERN_SOH "%c%sIN=%s OUT=%s ", '0' + loginfo->u.log.level, prefix, in ? in->name : "", out ? out->name : ""); #if IS_ENABLED(CONFIG_BRIDGE_NETFILTER) if (skb->nf_bridge) { const struct net_device *physindev; const struct net_device *physoutdev; physindev = nf_bridge_get_physindev(skb); if (physindev && in != physindev) nf_log_buf_add(m, "PHYSIN=%s ", physindev->name); physoutdev = nf_bridge_get_physoutdev(skb); if (physoutdev && out != physoutdev) nf_log_buf_add(m, "PHYSOUT=%s ", physoutdev->name); } #endif }
static void dump_ipv6_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 len = dev->hard_header_len; unsigned int i; if (dev->type == ARPHRD_SIT) { p -= ETH_HLEN; if (p < skb->head) p = NULL; } if (p != NULL) { nf_log_buf_add(m, "%02x", *p++); for (i = 1; i < len; i++) nf_log_buf_add(m, ":%02x", *p++); } nf_log_buf_add(m, " "); if (dev->type == ARPHRD_SIT) { const struct iphdr *iph = (struct iphdr *)skb_mac_header(skb); nf_log_buf_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr, &iph->daddr); } } else { nf_log_buf_add(m, " "); } }
void nf_log_dump_sk_uid_gid(struct nf_log_buf *m, struct sock *sk) { if (!sk || !sk_fullsock(sk)) 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; nf_log_buf_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); }
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, " "); }
int nf_log_dump_tcp_header(struct nf_log_buf *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 " */ nf_log_buf_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) { nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); return 1; } /* Max length: 20 "SPT=65535 DPT=65535 " */ nf_log_buf_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest)); /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ if (logflags & XT_LOG_TCPSEQ) { nf_log_buf_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq)); } /* Max length: 13 "WINDOW=65535 " */ nf_log_buf_add(m, "WINDOW=%u ", ntohs(th->window)); /* Max length: 9 "RES=0x3C " */ nf_log_buf_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) nf_log_buf_add(m, "CWR "); if (th->ece) nf_log_buf_add(m, "ECE "); if (th->urg) nf_log_buf_add(m, "URG "); if (th->ack) nf_log_buf_add(m, "ACK "); if (th->psh) nf_log_buf_add(m, "PSH "); if (th->rst) nf_log_buf_add(m, "RST "); if (th->syn) nf_log_buf_add(m, "SYN "); if (th->fin) nf_log_buf_add(m, "FIN "); /* Max length: 11 "URGP=65535 " */ nf_log_buf_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) { nf_log_buf_add(m, "OPT (TRUNCATED)"); return 1; } /* 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, ") "); } return 0; }
/* One level of recursion won't kill us */ static void dump_ipv6_packet(struct nf_log_buf *m, 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_DEFAULT_MASK; ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h); if (ih == NULL) { nf_log_buf_add(m, "TRUNCATED"); return; } /* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */ nf_log_buf_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr); /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ nf_log_buf_add(m, "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) { nf_log_buf_add(m, "TRUNCATED"); return; } /* Max length: 48 "OPT (...) " */ if (logflags & NF_LOG_IPOPT) nf_log_buf_add(m, "OPT ( "); switch (currenthdr) { case IPPROTO_FRAGMENT: { struct frag_hdr _fhdr; const struct frag_hdr *fh; nf_log_buf_add(m, "FRAG:"); fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), &_fhdr); if (fh == NULL) { nf_log_buf_add(m, "TRUNCATED "); return; } /* Max length: 6 "65535 " */ nf_log_buf_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8); /* Max length: 11 "INCOMPLETE " */ if (fh->frag_off & htons(0x0001)) nf_log_buf_add(m, "INCOMPLETE "); nf_log_buf_add(m, "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 & NF_LOG_IPOPT) nf_log_buf_add(m, ")"); return; } hdrlen = ipv6_optlen(hp); break; /* Max Length */ case IPPROTO_AH: if (logflags & NF_LOG_IPOPT) { struct ip_auth_hdr _ahdr; const struct ip_auth_hdr *ah; /* Max length: 3 "AH " */ nf_log_buf_add(m, "AH "); if (fragment) { nf_log_buf_add(m, ")"); return; } ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), &_ahdr); if (ah == NULL) { /* * Max length: 26 "INCOMPLETE [65535 * bytes] )" */ nf_log_buf_add(m, "INCOMPLETE [%u bytes] )", skb->len - ptr); return; } /* Length: 15 "SPI=0xF1234567 */ nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi)); } hdrlen = (hp->hdrlen+2)<<2; break; case IPPROTO_ESP: if (logflags & NF_LOG_IPOPT) { struct ip_esp_hdr _esph; const struct ip_esp_hdr *eh; /* Max length: 4 "ESP " */ nf_log_buf_add(m, "ESP "); if (fragment) { nf_log_buf_add(m, ")"); return; } /* * Max length: 26 "INCOMPLETE [65535 bytes] )" */ eh = skb_header_pointer(skb, ptr, sizeof(_esph), &_esph); if (eh == NULL) { nf_log_buf_add(m, "INCOMPLETE [%u bytes] )", skb->len - ptr); return; } /* Length: 16 "SPI=0xF1234567 )" */ nf_log_buf_add(m, "SPI=0x%x )", ntohl(eh->spi)); } return; default: /* Max length: 20 "Unknown Ext Hdr 255" */ nf_log_buf_add(m, "Unknown Ext Hdr %u", currenthdr); return; } if (logflags & NF_LOG_IPOPT) nf_log_buf_add(m, ") "); currenthdr = hp->nexthdr; ptr += hdrlen; } switch (currenthdr) { case IPPROTO_TCP: if (nf_log_dump_tcp_header(m, skb, currenthdr, fragment, ptr, logflags)) return; break; case IPPROTO_UDP: case IPPROTO_UDPLITE: if (nf_log_dump_udp_header(m, skb, currenthdr, fragment, ptr)) return; break; case IPPROTO_ICMPV6: { struct icmp6hdr _icmp6h; const struct icmp6hdr *ic; /* Max length: 13 "PROTO=ICMPv6 " */ nf_log_buf_add(m, "PROTO=ICMPv6 "); if (fragment) break; /* Max length: 25 "INCOMPLETE [65535 bytes] " */ ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h); if (ic == NULL) { nf_log_buf_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr); return; } /* Max length: 18 "TYPE=255 CODE=255 " */ nf_log_buf_add(m, "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 " */ nf_log_buf_add(m, "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 " */ nf_log_buf_add(m, "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) { nf_log_buf_add(m, "["); dump_ipv6_packet(m, info, skb, ptr + sizeof(_icmp6h), 0); nf_log_buf_add(m, "] "); } /* Max length: 10 "MTU=65535 " */ if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) { nf_log_buf_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu)); } } break; } /* Max length: 10 "PROTO=255 " */ default: nf_log_buf_add(m, "PROTO=%u ", currenthdr); } /* Max length: 15 "UID=4294967295 " */ if ((logflags & NF_LOG_UID) && recurse) nf_log_dump_sk_uid_gid(m, skb->sk); /* Max length: 16 "MARK=0xFFFFFFFF " */ if (recurse && skb->mark) nf_log_buf_add(m, "MARK=0x%x ", skb->mark); }
/* 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_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(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(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 */ }