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-rw-r--r--net/netfilter/nf_log_syslog.c1082
1 files changed, 1082 insertions, 0 deletions
diff --git a/net/netfilter/nf_log_syslog.c b/net/netfilter/nf_log_syslog.c
new file mode 100644
index 000000000000..cb894f0d63e9
--- /dev/null
+++ b/net/netfilter/nf_log_syslog.c
@@ -0,0 +1,1082 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* (C) 1999-2001 Paul `Rusty' Russell
+ * (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#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_bridge.h>
+#include <linux/netfilter_ipv6.h>
+#include <linux/netfilter/xt_LOG.h>
+#include <net/netfilter/nf_log.h>
+
+static const struct nf_loginfo default_loginfo = {
+ .type = NF_LOG_TYPE_LOG,
+ .u = {
+ .log = {
+ .level = LOGLEVEL_NOTICE,
+ .logflags = NF_LOG_DEFAULT_MASK,
+ },
+ },
+};
+
+struct arppayload {
+ unsigned char mac_src[ETH_ALEN];
+ unsigned char ip_src[4];
+ unsigned char mac_dst[ETH_ALEN];
+ unsigned char ip_dst[4];
+};
+
+/* Guard against containers flooding syslog. */
+static bool nf_log_allowed(const struct net *net)
+{
+ return net_eq(net, &init_net) || sysctl_nf_log_all_netns;
+}
+
+static void nf_log_dump_vlan(struct nf_log_buf *m, const struct sk_buff *skb)
+{
+ u16 vid;
+
+ if (!skb_vlan_tag_present(skb))
+ return;
+
+ vid = skb_vlan_tag_get(skb);
+ nf_log_buf_add(m, "VPROTO=%04x VID=%u ", ntohs(skb->vlan_proto), vid);
+}
+static void noinline_for_stack
+dump_arp_packet(struct nf_log_buf *m,
+ const struct nf_loginfo *info,
+ const struct sk_buff *skb, unsigned int nhoff)
+{
+ const struct arppayload *ap;
+ struct arppayload _arpp;
+ const struct arphdr *ah;
+ unsigned int logflags;
+ struct arphdr _arph;
+
+ ah = skb_header_pointer(skb, nhoff, sizeof(_arph), &_arph);
+ if (!ah) {
+ nf_log_buf_add(m, "TRUNCATED");
+ return;
+ }
+
+ if (info->type == NF_LOG_TYPE_LOG)
+ logflags = info->u.log.logflags;
+ else
+ logflags = NF_LOG_DEFAULT_MASK;
+
+ if (logflags & NF_LOG_MACDECODE) {
+ nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM ",
+ eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest);
+ nf_log_dump_vlan(m, skb);
+ nf_log_buf_add(m, "MACPROTO=%04x ",
+ ntohs(eth_hdr(skb)->h_proto));
+ }
+
+ 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(ARPHRD_ETHER) ||
+ ah->ar_hln != ETH_ALEN ||
+ ah->ar_pln != sizeof(__be32))
+ return;
+
+ ap = skb_header_pointer(skb, nhoff + sizeof(_arph), sizeof(_arpp), &_arpp);
+ if (!ap) {
+ 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);
+}
+
+static void
+nf_log_dump_packet_common(struct nf_log_buf *m, u8 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)
+{
+ const struct net_device *physoutdev __maybe_unused;
+ const struct net_device *physindev __maybe_unused;
+
+ 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)
+ 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 nf_log_arp_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;
+
+ if (!nf_log_allowed(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);
+ dump_arp_packet(m, loginfo, skb, skb_network_offset(skb));
+
+ nf_log_buf_close(m);
+}
+
+static struct nf_logger nf_arp_logger __read_mostly = {
+ .name = "nf_log_arp",
+ .type = NF_LOG_TYPE_LOG,
+ .logfn = nf_log_arp_packet,
+ .me = THIS_MODULE,
+};
+
+static void nf_log_dump_sk_uid_gid(struct net *net, struct nf_log_buf *m,
+ struct sock *sk)
+{
+ if (!sk || !sk_fullsock(sk) || !net_eq(net, sock_net(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 noinline_for_stack 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) {
+ 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 & NF_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 & NF_LOG_TCPOPT) && th->doff * 4 > sizeof(struct tcphdr)) {
+ unsigned int optsize = th->doff * 4 - sizeof(struct tcphdr);
+ u8 _opt[60 - sizeof(struct tcphdr)];
+ unsigned int i;
+ const u8 *op;
+
+ op = skb_header_pointer(skb, offset + sizeof(struct tcphdr),
+ optsize, _opt);
+ if (!op) {
+ 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;
+}
+
+static noinline_for_stack 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) {
+ 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;
+}
+
+/* One level of recursion won't kill us */
+static noinline_for_stack void
+dump_ipv4_packet(struct net *net, struct nf_log_buf *m,
+ const struct nf_loginfo *info,
+ const struct sk_buff *skb, unsigned int iphoff)
+{
+ const struct iphdr *ih;
+ unsigned int logflags;
+ struct iphdr _iph;
+
+ 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) {
+ 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)) {
+ unsigned char _opt[4 * 15 - sizeof(struct iphdr)];
+ const unsigned char *op;
+ unsigned int i, optsize;
+
+ optsize = ih->ihl * 4 - sizeof(struct iphdr);
+ op = skb_header_pointer(skb, iphoff + sizeof(_iph),
+ optsize, _opt);
+ if (!op) {
+ 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: {
+ 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 };
+ const struct icmphdr *ich;
+ struct icmphdr _icmph;
+
+ /* 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) {
+ 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);
+ fallthrough;
+ 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(net, 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: {
+ const struct ip_auth_hdr *ah;
+ struct ip_auth_hdr _ahdr;
+
+ 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) {
+ 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: {
+ const struct ip_esp_hdr *eh;
+ struct ip_esp_hdr _esph;
+
+ /* 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) {
+ 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(net, 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 noinline_for_stack void
+dump_ipv6_packet(struct net *net, struct nf_log_buf *m,
+ const struct nf_loginfo *info,
+ const struct sk_buff *skb, unsigned int ip6hoff,
+ int recurse)
+{
+ const struct ipv6hdr *ih;
+ unsigned int hdrlen = 0;
+ unsigned int logflags;
+ struct ipv6hdr _ip6h;
+ unsigned int ptr;
+ u8 currenthdr;
+ int fragment;
+
+ 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) {
+ 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 && nf_ip6_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) {
+ 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) {
+ 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) {
+ /* 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 = ipv6_authlen(hp);
+ 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) {
+ 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) {
+ 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));
+ fallthrough;
+ 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(net, 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(net, m, skb->sk);
+
+ /* Max length: 16 "MARK=0xFFFFFFFF " */
+ if (recurse && skb->mark)
+ nf_log_buf_add(m, "MARK=0x%x ", skb->mark);
+}
+
+static void dump_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 ",
+ eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest);
+ nf_log_dump_vlan(m, skb);
+ nf_log_buf_add(m, "MACPROTO=%04x ",
+ 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;
+
+ if (dev->type == ARPHRD_SIT) {
+ p -= ETH_HLEN;
+
+ if (p < skb->head)
+ p = NULL;
+ }
+
+ if (p) {
+ nf_log_buf_add(m, "%02x", *p++);
+ for (i = 1; i < dev->hard_header_len; i++)
+ nf_log_buf_add(m, ":%02x", *p++);
+ }
+
+ 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);
+ }
+ }
+ 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;
+
+ if (!nf_log_allowed(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)
+ dump_mac_header(m, loginfo, skb);
+
+ dump_ipv4_packet(net, m, loginfo, skb, skb_network_offset(skb));
+
+ 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 void nf_log_ip6_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;
+
+ if (!nf_log_allowed(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)
+ dump_mac_header(m, loginfo, skb);
+
+ dump_ipv6_packet(net, m, loginfo, skb, skb_network_offset(skb), 1);
+
+ nf_log_buf_close(m);
+}
+
+static struct nf_logger nf_ip6_logger __read_mostly = {
+ .name = "nf_log_ipv6",
+ .type = NF_LOG_TYPE_LOG,
+ .logfn = nf_log_ip6_packet,
+ .me = THIS_MODULE,
+};
+
+static void nf_log_unknown_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;
+
+ if (!nf_log_allowed(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);
+
+ dump_mac_header(m, loginfo, skb);
+
+ nf_log_buf_close(m);
+}
+
+static void nf_log_netdev_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)
+{
+ switch (skb->protocol) {
+ case htons(ETH_P_IP):
+ nf_log_ip_packet(net, pf, hooknum, skb, in, out, loginfo, prefix);
+ break;
+ case htons(ETH_P_IPV6):
+ nf_log_ip6_packet(net, pf, hooknum, skb, in, out, loginfo, prefix);
+ break;
+ case htons(ETH_P_ARP):
+ case htons(ETH_P_RARP):
+ nf_log_arp_packet(net, pf, hooknum, skb, in, out, loginfo, prefix);
+ break;
+ default:
+ nf_log_unknown_packet(net, pf, hooknum, skb,
+ in, out, loginfo, prefix);
+ break;
+ }
+}
+
+static struct nf_logger nf_netdev_logger __read_mostly = {
+ .name = "nf_log_netdev",
+ .type = NF_LOG_TYPE_LOG,
+ .logfn = nf_log_netdev_packet,
+ .me = THIS_MODULE,
+};
+
+static struct nf_logger nf_bridge_logger __read_mostly = {
+ .name = "nf_log_bridge",
+ .type = NF_LOG_TYPE_LOG,
+ .logfn = nf_log_netdev_packet,
+ .me = THIS_MODULE,
+};
+
+static int __net_init nf_log_syslog_net_init(struct net *net)
+{
+ int ret = nf_log_set(net, NFPROTO_IPV4, &nf_ip_logger);
+
+ if (ret)
+ return ret;
+
+ ret = nf_log_set(net, NFPROTO_ARP, &nf_arp_logger);
+ if (ret)
+ goto err1;
+
+ ret = nf_log_set(net, NFPROTO_IPV6, &nf_ip6_logger);
+ if (ret)
+ goto err2;
+
+ ret = nf_log_set(net, NFPROTO_NETDEV, &nf_netdev_logger);
+ if (ret)
+ goto err3;
+
+ ret = nf_log_set(net, NFPROTO_BRIDGE, &nf_bridge_logger);
+ if (ret)
+ goto err4;
+ return 0;
+err4:
+ nf_log_unset(net, &nf_netdev_logger);
+err3:
+ nf_log_unset(net, &nf_ip6_logger);
+err2:
+ nf_log_unset(net, &nf_arp_logger);
+err1:
+ nf_log_unset(net, &nf_ip_logger);
+ return ret;
+}
+
+static void __net_exit nf_log_syslog_net_exit(struct net *net)
+{
+ nf_log_unset(net, &nf_ip_logger);
+ nf_log_unset(net, &nf_arp_logger);
+ nf_log_unset(net, &nf_ip6_logger);
+ nf_log_unset(net, &nf_netdev_logger);
+ nf_log_unset(net, &nf_bridge_logger);
+}
+
+static struct pernet_operations nf_log_syslog_net_ops = {
+ .init = nf_log_syslog_net_init,
+ .exit = nf_log_syslog_net_exit,
+};
+
+static int __init nf_log_syslog_init(void)
+{
+ int ret;
+
+ ret = register_pernet_subsys(&nf_log_syslog_net_ops);
+ if (ret < 0)
+ return ret;
+
+ ret = nf_log_register(NFPROTO_IPV4, &nf_ip_logger);
+ if (ret < 0)
+ goto err1;
+
+ ret = nf_log_register(NFPROTO_ARP, &nf_arp_logger);
+ if (ret < 0)
+ goto err2;
+
+ ret = nf_log_register(NFPROTO_IPV6, &nf_ip6_logger);
+ if (ret < 0)
+ goto err3;
+
+ ret = nf_log_register(NFPROTO_NETDEV, &nf_netdev_logger);
+ if (ret < 0)
+ goto err4;
+
+ ret = nf_log_register(NFPROTO_BRIDGE, &nf_bridge_logger);
+ if (ret < 0)
+ goto err5;
+
+ return 0;
+err5:
+ nf_log_unregister(&nf_netdev_logger);
+err4:
+ nf_log_unregister(&nf_ip6_logger);
+err3:
+ nf_log_unregister(&nf_arp_logger);
+err2:
+ nf_log_unregister(&nf_ip_logger);
+err1:
+ pr_err("failed to register logger\n");
+ unregister_pernet_subsys(&nf_log_syslog_net_ops);
+ return ret;
+}
+
+static void __exit nf_log_syslog_exit(void)
+{
+ unregister_pernet_subsys(&nf_log_syslog_net_ops);
+ nf_log_unregister(&nf_ip_logger);
+ nf_log_unregister(&nf_arp_logger);
+ nf_log_unregister(&nf_ip6_logger);
+ nf_log_unregister(&nf_netdev_logger);
+ nf_log_unregister(&nf_bridge_logger);
+}
+
+module_init(nf_log_syslog_init);
+module_exit(nf_log_syslog_exit);
+
+MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
+MODULE_DESCRIPTION("Netfilter syslog packet logging");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("nf_log_arp");
+MODULE_ALIAS("nf_log_bridge");
+MODULE_ALIAS("nf_log_ipv4");
+MODULE_ALIAS("nf_log_ipv6");
+MODULE_ALIAS("nf_log_netdev");
+MODULE_ALIAS_NF_LOGGER(AF_BRIDGE, 0);
+MODULE_ALIAS_NF_LOGGER(AF_INET, 0);
+MODULE_ALIAS_NF_LOGGER(3, 0);
+MODULE_ALIAS_NF_LOGGER(5, 0); /* NFPROTO_NETDEV */
+MODULE_ALIAS_NF_LOGGER(AF_INET6, 0);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.