use kernel packet logging code, just adding some compat skbuff/nf_log_buf and disable some blocks using ifdefs. --- include/Makefile.am | 1 + include/log.h | 17 ++ src/Makefile.am | 1 + src/log.c | 779 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 798 insertions(+) create mode 100644 include/log.h create mode 100644 src/log.c diff --git a/include/Makefile.am b/include/Makefile.am index c351b55..7951587 100644 --- a/include/Makefile.am +++ b/include/Makefile.am @@ -20,4 +20,5 @@ noinst_HEADERS = cli.h \ proto.h \ rule.h \ trace.h \ + log.h \ utils.h diff --git a/include/log.h b/include/log.h new file mode 100644 index 0000000..22545f4 --- /dev/null +++ b/include/log.h @@ -0,0 +1,17 @@ +#include <stdint.h> +#include <inttypes.h> + +struct nf_log_buf; + +void nf_log_buf_init(struct nf_log_buf *); +int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...); +void nf_log_buf_exit(struct nf_log_buf *m); + +struct nlattr; +void nf_log_packet(struct nlattr *tb[]); + +#define IP_CE 0x8000 /* Flag: "Congestion" */ +#define IP_DF 0x4000 /* Flag: "Don't Fragment" */ +#define IP_MF 0x2000 /* Flag: "More Fragments" */ +#define IP_OFFSET 0x1FFF /* "Fragment Offset" part */ + diff --git a/src/Makefile.am b/src/Makefile.am index db77e8e..3fd07ca 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -46,6 +46,7 @@ nft_SOURCES = main.c \ mnl.c \ scanner.l \ trace.c \ + log.c \ parser_bison.y if BUILD_CLI diff --git a/src/log.c b/src/log.c new file mode 100644 index 0000000..410c21e --- /dev/null +++ b/src/log.c @@ -0,0 +1,779 @@ +#include <stdio.h> +#include <stdlib.h> +#include <stdarg.h> + +#include <stddef.h> +#include <stdint.h> +#include <string.h> +#include <net/if_arp.h> +#include <net/ethernet.h> +#include <net/if.h> +#include <arpa/inet.h> + +#include <linux/ip.h> +#include <linux/ipv6.h> +#include <linux/icmp.h> +#include <linux/icmpv6.h> +#include <linux/if_ether.h> +#include <linux/tcp.h> +#include <linux/udp.h> + +#include <log.h> +#include <linux/netfilter/nfnetlink_log.h> +#include <libnfnetlink/libnfnetlink.h> + + +#include <libmnl/libmnl.h> + +#define S_SIZE (1024 - (sizeof(unsigned int) + 1)) + +struct nf_log_buf { + unsigned int count; + char buf[S_SIZE + 1]; +}; + +int nf_log_buf_add(struct nf_log_buf *m, const char *f, ...) +{ + va_list args; + int len; + + if (m->count < S_SIZE) { + va_start(args, f); + len = vsnprintf(m->buf + m->count, S_SIZE - m->count, f, args); + va_end(args); + if (m->count + len < S_SIZE) { + m->count += len; + return 0; + } + } + m->count = S_SIZE; + return -1; +} + +void nf_log_buf_init(struct nf_log_buf *m) +{ + m->count = 0; +} + +void nf_log_buf_exit(struct nf_log_buf *m) +{ + m->buf[m->count] = 0; +} + +struct sk_buff +{ + void *data; + uint16_t len; + uint32_t mark; +}; + +static void *skb_header_pointer(const struct sk_buff *skb, int offset, int len, void *dest) +{ + if (skb->len-offset < len) + return NULL; + memcpy(dest, &((unsigned char *)skb->data)[offset], len); + return dest; +} + +struct nf_loginfo +{ + int type; +}; + +#define u8 uint8_t + +static 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 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)); + +#ifdef XT_LOG_TCPSEQ + /* 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)); + } +#endif + + /* 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)); + +#ifdef XT_LOG_TCPOPT + 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, ") "); + } +#endif + return 0; +} + +#define NEXTHDR_NONE 59 +static inline int +ip6t_ext_hdr(u8 nexthdr) +{ return (nexthdr == IPPROTO_HOPOPTS) || + (nexthdr == IPPROTO_ROUTING) || + (nexthdr == IPPROTO_FRAGMENT) || + (nexthdr == IPPROTO_ESP) || + (nexthdr == IPPROTO_AH) || + (nexthdr == IPPROTO_NONE) || + (nexthdr == IPPROTO_DSTOPTS); +} + +/* 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; + +#ifdef NF_LOG_TYPE_LOG + if (info->type == NF_LOG_TYPE_LOG) + logflags = info->u.log.logflags; + else + logflags = NF_LOG_MASK; +#endif + + 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); + { + char src[INET6_ADDRSTRLEN+1], dst[INET6_ADDRSTRLEN+1]; + nf_log_buf_add(m, "SRC=%s DST=%s ", + inet_ntop(AF_INET6, (void *)&ih->saddr, src, sizeof(src)), + inet_ntop(AF_INET6, (void *)&ih->daddr, dst, sizeof(dst))); + } + + /* 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; + } + +#ifdef XT_LOG_IPOPT + /* Max length: 48 "OPT (...) " */ + if (logflags & XT_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 & XT_LOG_IPOPT) + nf_log_buf_add(m, ")"); + return; + } + hdrlen = ipv6_optlen(hp); + break; + /* Max Length */ + case IPPROTO_AH: + if (logflags & XT_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 & XT_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 & XT_LOG_IPOPT) + nf_log_buf_add(m, ") "); +#endif + + 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); + } + +#ifdef XT_LOG_UID + /* Max length: 15 "UID=4294967295 " */ + if ((logflags & XT_LOG_UID) && recurse) + nf_log_dump_sk_uid_gid(m, skb->sk); +#endif + + /* 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; + +#ifdef NF_LOG_TYPE_LOG + if (info->type == NF_LOG_TYPE_LOG) + logflags = info->u.log.logflags; + else + logflags = NF_LOG_MASK; +#endif + + 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); + { + char src[INET_ADDRSTRLEN+1], dst[INET_ADDRSTRLEN+1]; + nf_log_buf_add(m, "SRC=%s DST=%s ", + inet_ntop(AF_INET, (void *)&ih->saddr, src, sizeof(src)), + inet_ntop(AF_INET, (void *)&ih->daddr, dst, sizeof(dst))); + } + + /* 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); + +#ifdef XT_LOG_IPOPT + 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, ") "); + } +#endif + + 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); + } + +#ifdef XT_LOG_UID + /* Max length: 15 "UID=4294967295 " */ + if ((logflags & XT_LOG_UID) && !iphoff) + nf_log_dump_sk_uid_gid(m, skb->sk); +#endif + + /* 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 */ +} + +void nf_log_packet(struct nlattr *tb[]) +{ + struct nf_log_buf m; + struct nfulnl_msg_packet_hdr *ph = NULL; + + nf_log_buf_init(&m); + + if (tb[NFULA_IFINDEX_INDEV]) { + char ifname[IFNAMSIZ]; + if_indextoname(ntohl(mnl_attr_get_u32(tb[NFULA_IFINDEX_INDEV])), ifname); + nf_log_buf_add(&m, "IN=%s ", ifname); + }else + nf_log_buf_add(&m, "IN= "); + + if (tb[NFULA_IFINDEX_OUTDEV]) { + char ifname[IFNAMSIZ]; + if_indextoname(ntohl(mnl_attr_get_u32(tb[NFULA_IFINDEX_OUTDEV])), ifname); + nf_log_buf_add(&m, "OUT=%s ", ifname); + }else + nf_log_buf_add(&m, "OUT= "); + + /* + if (tb[NFULA_HWHEADER] && tb[NFULA_HWLEN]) + { + uint16_t hwlen = ntohs(mnl_attr_get_u16(tb[NFULA_HWLEN])); + unsigned char *hwheader = mnl_attr_get_payload(tb[NFULA_HWHEADER]); + } + */ + + if (tb[NFULA_PACKET_HDR]) + ph = mnl_attr_get_payload(tb[NFULA_PACKET_HDR]); + + if(ph && tb[NFULA_PAYLOAD]) + { + struct sk_buff skb = + { + .data = mnl_attr_get_payload(tb[NFULA_PAYLOAD]), + .len = NFA_PAYLOAD((struct nfattr *)tb[NFULA_PAYLOAD]), + .mark = 0, + }; + + switch (ntohs(ph->hw_protocol)) { + case ETHERTYPE_IP: + dump_ipv4_packet(&m, NULL, &skb, 0); + break; + + case ETHERTYPE_IPV6: + dump_ipv6_packet(&m, NULL, &skb, 0, 1); + break; + + default: + nf_log_buf_add(&m, "NOT IMPLEMENTED"); + } + + } + + nf_log_buf_exit(&m); + printf("%s\n", m.buf); +} -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html