// SPDX-License-Identifier: GPL-2.0-only
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/* (C) 1999-2001 Paul `Rusty' Russell
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* (C) 2002-2004 Netfilter Core Team <coreteam@netfilter.org>
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/spinlock.h>
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#include <linux/skbuff.h>
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#include <linux/if_arp.h>
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#include <linux/ip.h>
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#include <net/ipv6.h>
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#include <net/icmp.h>
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#include <net/udp.h>
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#include <net/tcp.h>
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#include <net/route.h>
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#include <linux/netfilter.h>
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#include <linux/netfilter_ipv6.h>
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#include <linux/netfilter/xt_LOG.h>
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#include <net/netfilter/nf_log.h>
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static const struct nf_loginfo default_loginfo = {
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.type = NF_LOG_TYPE_LOG,
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.u = {
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.log = {
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.level = LOGLEVEL_NOTICE,
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.logflags = NF_LOG_DEFAULT_MASK,
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},
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},
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};
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/* One level of recursion won't kill us */
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static void dump_ipv6_packet(struct net *net, struct nf_log_buf *m,
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const struct nf_loginfo *info,
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const struct sk_buff *skb, unsigned int ip6hoff,
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int recurse)
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{
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u_int8_t currenthdr;
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int fragment;
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struct ipv6hdr _ip6h;
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const struct ipv6hdr *ih;
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unsigned int ptr;
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unsigned int hdrlen = 0;
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unsigned int logflags;
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if (info->type == NF_LOG_TYPE_LOG)
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logflags = info->u.log.logflags;
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else
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logflags = NF_LOG_DEFAULT_MASK;
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ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h);
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if (ih == NULL) {
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nf_log_buf_add(m, "TRUNCATED");
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return;
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}
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/* Max length: 88 "SRC=0000.0000.0000.0000.0000.0000.0000.0000 DST=0000.0000.0000.0000.0000.0000.0000.0000 " */
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nf_log_buf_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr);
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/* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */
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nf_log_buf_add(m, "LEN=%zu TC=%u HOPLIMIT=%u FLOWLBL=%u ",
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ntohs(ih->payload_len) + sizeof(struct ipv6hdr),
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(ntohl(*(__be32 *)ih) & 0x0ff00000) >> 20,
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ih->hop_limit,
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(ntohl(*(__be32 *)ih) & 0x000fffff));
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fragment = 0;
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ptr = ip6hoff + sizeof(struct ipv6hdr);
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currenthdr = ih->nexthdr;
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while (currenthdr != NEXTHDR_NONE && nf_ip6_ext_hdr(currenthdr)) {
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struct ipv6_opt_hdr _hdr;
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const struct ipv6_opt_hdr *hp;
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hp = skb_header_pointer(skb, ptr, sizeof(_hdr), &_hdr);
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if (hp == NULL) {
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nf_log_buf_add(m, "TRUNCATED");
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return;
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}
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/* Max length: 48 "OPT (...) " */
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if (logflags & NF_LOG_IPOPT)
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nf_log_buf_add(m, "OPT ( ");
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switch (currenthdr) {
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case IPPROTO_FRAGMENT: {
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struct frag_hdr _fhdr;
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const struct frag_hdr *fh;
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nf_log_buf_add(m, "FRAG:");
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fh = skb_header_pointer(skb, ptr, sizeof(_fhdr),
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&_fhdr);
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if (fh == NULL) {
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nf_log_buf_add(m, "TRUNCATED ");
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return;
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}
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/* Max length: 6 "65535 " */
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nf_log_buf_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8);
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/* Max length: 11 "INCOMPLETE " */
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if (fh->frag_off & htons(0x0001))
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nf_log_buf_add(m, "INCOMPLETE ");
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nf_log_buf_add(m, "ID:%08x ",
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ntohl(fh->identification));
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if (ntohs(fh->frag_off) & 0xFFF8)
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fragment = 1;
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hdrlen = 8;
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break;
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}
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case IPPROTO_DSTOPTS:
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case IPPROTO_ROUTING:
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case IPPROTO_HOPOPTS:
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if (fragment) {
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if (logflags & NF_LOG_IPOPT)
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nf_log_buf_add(m, ")");
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return;
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}
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hdrlen = ipv6_optlen(hp);
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break;
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/* Max Length */
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case IPPROTO_AH:
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if (logflags & NF_LOG_IPOPT) {
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struct ip_auth_hdr _ahdr;
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const struct ip_auth_hdr *ah;
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/* Max length: 3 "AH " */
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nf_log_buf_add(m, "AH ");
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if (fragment) {
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nf_log_buf_add(m, ")");
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return;
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}
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ah = skb_header_pointer(skb, ptr, sizeof(_ahdr),
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&_ahdr);
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if (ah == NULL) {
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/*
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* Max length: 26 "INCOMPLETE [65535
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* bytes] )"
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*/
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nf_log_buf_add(m, "INCOMPLETE [%u bytes] )",
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skb->len - ptr);
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return;
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}
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/* Length: 15 "SPI=0xF1234567 */
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nf_log_buf_add(m, "SPI=0x%x ", ntohl(ah->spi));
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}
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hdrlen = ipv6_authlen(hp);
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break;
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case IPPROTO_ESP:
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if (logflags & NF_LOG_IPOPT) {
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struct ip_esp_hdr _esph;
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const struct ip_esp_hdr *eh;
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/* Max length: 4 "ESP " */
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nf_log_buf_add(m, "ESP ");
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if (fragment) {
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nf_log_buf_add(m, ")");
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return;
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}
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/*
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* Max length: 26 "INCOMPLETE [65535 bytes] )"
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*/
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eh = skb_header_pointer(skb, ptr, sizeof(_esph),
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&_esph);
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if (eh == NULL) {
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nf_log_buf_add(m, "INCOMPLETE [%u bytes] )",
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skb->len - ptr);
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return;
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}
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/* Length: 16 "SPI=0xF1234567 )" */
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nf_log_buf_add(m, "SPI=0x%x )",
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ntohl(eh->spi));
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}
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return;
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default:
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/* Max length: 20 "Unknown Ext Hdr 255" */
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nf_log_buf_add(m, "Unknown Ext Hdr %u", currenthdr);
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return;
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}
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if (logflags & NF_LOG_IPOPT)
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nf_log_buf_add(m, ") ");
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currenthdr = hp->nexthdr;
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ptr += hdrlen;
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}
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switch (currenthdr) {
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case IPPROTO_TCP:
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if (nf_log_dump_tcp_header(m, skb, currenthdr, fragment,
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ptr, logflags))
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return;
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break;
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case IPPROTO_UDP:
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case IPPROTO_UDPLITE:
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if (nf_log_dump_udp_header(m, skb, currenthdr, fragment, ptr))
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return;
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break;
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case IPPROTO_ICMPV6: {
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struct icmp6hdr _icmp6h;
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const struct icmp6hdr *ic;
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/* Max length: 13 "PROTO=ICMPv6 " */
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nf_log_buf_add(m, "PROTO=ICMPv6 ");
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if (fragment)
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break;
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/* Max length: 25 "INCOMPLETE [65535 bytes] " */
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ic = skb_header_pointer(skb, ptr, sizeof(_icmp6h), &_icmp6h);
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if (ic == NULL) {
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nf_log_buf_add(m, "INCOMPLETE [%u bytes] ",
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skb->len - ptr);
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return;
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}
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/* Max length: 18 "TYPE=255 CODE=255 " */
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nf_log_buf_add(m, "TYPE=%u CODE=%u ",
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ic->icmp6_type, ic->icmp6_code);
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switch (ic->icmp6_type) {
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case ICMPV6_ECHO_REQUEST:
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case ICMPV6_ECHO_REPLY:
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/* Max length: 19 "ID=65535 SEQ=65535 " */
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nf_log_buf_add(m, "ID=%u SEQ=%u ",
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ntohs(ic->icmp6_identifier),
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ntohs(ic->icmp6_sequence));
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break;
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case ICMPV6_MGM_QUERY:
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case ICMPV6_MGM_REPORT:
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case ICMPV6_MGM_REDUCTION:
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break;
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case ICMPV6_PARAMPROB:
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/* Max length: 17 "POINTER=ffffffff " */
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nf_log_buf_add(m, "POINTER=%08x ",
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ntohl(ic->icmp6_pointer));
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fallthrough;
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case ICMPV6_DEST_UNREACH:
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case ICMPV6_PKT_TOOBIG:
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case ICMPV6_TIME_EXCEED:
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/* Max length: 3+maxlen */
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if (recurse) {
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nf_log_buf_add(m, "[");
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dump_ipv6_packet(net, m, info, skb,
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ptr + sizeof(_icmp6h), 0);
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nf_log_buf_add(m, "] ");
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}
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/* Max length: 10 "MTU=65535 " */
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if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) {
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nf_log_buf_add(m, "MTU=%u ",
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ntohl(ic->icmp6_mtu));
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}
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}
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break;
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}
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/* Max length: 10 "PROTO=255 " */
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default:
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nf_log_buf_add(m, "PROTO=%u ", currenthdr);
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}
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/* Max length: 15 "UID=4294967295 " */
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if ((logflags & NF_LOG_UID) && recurse)
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nf_log_dump_sk_uid_gid(net, m, skb->sk);
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/* Max length: 16 "MARK=0xFFFFFFFF " */
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if (recurse && skb->mark)
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nf_log_buf_add(m, "MARK=0x%x ", skb->mark);
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}
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static void dump_ipv6_mac_header(struct nf_log_buf *m,
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const struct nf_loginfo *info,
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const struct sk_buff *skb)
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{
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struct net_device *dev = skb->dev;
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unsigned int logflags = 0;
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if (info->type == NF_LOG_TYPE_LOG)
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logflags = info->u.log.logflags;
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if (!(logflags & NF_LOG_MACDECODE))
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goto fallback;
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switch (dev->type) {
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case ARPHRD_ETHER:
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nf_log_buf_add(m, "MACSRC=%pM MACDST=%pM ",
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eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest);
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nf_log_dump_vlan(m, skb);
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nf_log_buf_add(m, "MACPROTO=%04x ",
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ntohs(eth_hdr(skb)->h_proto));
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return;
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default:
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break;
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}
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fallback:
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nf_log_buf_add(m, "MAC=");
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if (dev->hard_header_len &&
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skb->mac_header != skb->network_header) {
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const unsigned char *p = skb_mac_header(skb);
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unsigned int len = dev->hard_header_len;
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unsigned int i;
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if (dev->type == ARPHRD_SIT) {
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p -= ETH_HLEN;
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if (p < skb->head)
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p = NULL;
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}
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if (p != NULL) {
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nf_log_buf_add(m, "%02x", *p++);
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for (i = 1; i < len; i++)
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nf_log_buf_add(m, ":%02x", *p++);
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}
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nf_log_buf_add(m, " ");
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if (dev->type == ARPHRD_SIT) {
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const struct iphdr *iph =
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(struct iphdr *)skb_mac_header(skb);
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nf_log_buf_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr,
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&iph->daddr);
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}
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} else {
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nf_log_buf_add(m, " ");
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}
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}
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static void nf_log_ip6_packet(struct net *net, u_int8_t pf,
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unsigned int hooknum, const struct sk_buff *skb,
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const struct net_device *in,
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const struct net_device *out,
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const struct nf_loginfo *loginfo,
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const char *prefix)
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{
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struct nf_log_buf *m;
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/* FIXME: Disabled from containers until syslog ns is supported */
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if (!net_eq(net, &init_net) && !sysctl_nf_log_all_netns)
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return;
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m = nf_log_buf_open();
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if (!loginfo)
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loginfo = &default_loginfo;
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nf_log_dump_packet_common(m, pf, hooknum, skb, in, out,
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loginfo, prefix);
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if (in != NULL)
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dump_ipv6_mac_header(m, loginfo, skb);
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dump_ipv6_packet(net, m, loginfo, skb, skb_network_offset(skb), 1);
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nf_log_buf_close(m);
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}
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static struct nf_logger nf_ip6_logger __read_mostly = {
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.name = "nf_log_ipv6",
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.type = NF_LOG_TYPE_LOG,
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.logfn = nf_log_ip6_packet,
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.me = THIS_MODULE,
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};
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static int __net_init nf_log_ipv6_net_init(struct net *net)
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{
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return nf_log_set(net, NFPROTO_IPV6, &nf_ip6_logger);
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}
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static void __net_exit nf_log_ipv6_net_exit(struct net *net)
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{
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nf_log_unset(net, &nf_ip6_logger);
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}
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static struct pernet_operations nf_log_ipv6_net_ops = {
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.init = nf_log_ipv6_net_init,
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.exit = nf_log_ipv6_net_exit,
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};
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static int __init nf_log_ipv6_init(void)
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{
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int ret;
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ret = register_pernet_subsys(&nf_log_ipv6_net_ops);
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if (ret < 0)
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return ret;
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ret = nf_log_register(NFPROTO_IPV6, &nf_ip6_logger);
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if (ret < 0) {
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pr_err("failed to register logger\n");
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goto err1;
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}
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return 0;
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err1:
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unregister_pernet_subsys(&nf_log_ipv6_net_ops);
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return ret;
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}
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static void __exit nf_log_ipv6_exit(void)
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{
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unregister_pernet_subsys(&nf_log_ipv6_net_ops);
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nf_log_unregister(&nf_ip6_logger);
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}
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module_init(nf_log_ipv6_init);
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module_exit(nf_log_ipv6_exit);
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MODULE_AUTHOR("Netfilter Core Team <coreteam@netfilter.org>");
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MODULE_DESCRIPTION("Netfilter IPv6 packet logging");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_NF_LOGGER(AF_INET6, 0);
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