From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752663Ab2AVWpE (ORCPT ); Sun, 22 Jan 2012 17:45:04 -0500 Received: from a.ns.miles-group.at ([95.130.255.143]:47848 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752520Ab2AVWoR (ORCPT ); Sun, 22 Jan 2012 17:44:17 -0500 From: Richard Weinberger To: netfilter-devel@vger.kernel.org Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, eric.dumazet@gmail.com, jengelh@medozas.de, Richard Weinberger Subject: [PATCH 4/6] Netfilter: xt_LOG: Implement ring buffer support Date: Sun, 22 Jan 2012 22:56:19 +0100 Message-Id: <1327269381-20748-5-git-send-email-richard@nod.at> X-Mailer: git-send-email 1.7.7 In-Reply-To: <1327269381-20748-1-git-send-email-richard@nod.at> References: <1327269381-20748-1-git-send-email-richard@nod.at> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch introduces NETFILTER_XT_TARGET_LOG_RING. It allows logging into various ring buffers which are represented as pipe-like files in /proc/net/netfilter/xt_LOG_ring/. Signed-off-by: Richard Weinberger --- include/linux/netfilter/xt_LOG.h | 13 +- include/net/netfilter/nf_log.h | 1 + include/net/netfilter/xt_log_ring.h | 24 + net/netfilter/Kconfig | 13 + net/netfilter/Makefile | 2 + net/netfilter/xt_LOG.c | 921 ----------------------------- net/netfilter/xt_LOG_core.c | 1102 +++++++++++++++++++++++++++++++++++ net/netfilter/xt_LOG_ring.c | 430 ++++++++++++++ 8 files changed, 1584 insertions(+), 922 deletions(-) create mode 100644 include/net/netfilter/xt_log_ring.h delete mode 100644 net/netfilter/xt_LOG.c create mode 100644 net/netfilter/xt_LOG_core.c create mode 100644 net/netfilter/xt_LOG_ring.c diff --git a/include/linux/netfilter/xt_LOG.h b/include/linux/netfilter/xt_LOG.h index cac0790..4df80ce 100644 --- a/include/linux/netfilter/xt_LOG.h +++ b/include/linux/netfilter/xt_LOG.h @@ -8,7 +8,8 @@ #define XT_LOG_UID 0x08 /* Log UID owning local socket */ #define XT_LOG_NFLOG 0x10 /* Unsupported, don't reuse */ #define XT_LOG_MACDECODE 0x20 /* Decode MAC header */ -#define XT_LOG_MASK 0x2f +#define XT_LOG_ADD_TIMESTAMP 0x40 /* Add a timestamp */ +#define XT_LOG_MASK 0x6f struct xt_log_info { unsigned char level; @@ -16,4 +17,14 @@ struct xt_log_info { char prefix[30]; }; +struct xt_log_info_v1 { + unsigned char level; + unsigned char logflags; + char prefix[30]; + + char ring_name[30]; + unsigned long ring_size; + struct xt_LOG_ring_ctx *rctx; +}; + #endif /* _XT_LOG_H */ diff --git a/include/net/netfilter/nf_log.h b/include/net/netfilter/nf_log.h index e991bd0..18a94f9 100644 --- a/include/net/netfilter/nf_log.h +++ b/include/net/netfilter/nf_log.h @@ -14,6 +14,7 @@ #define NF_LOG_TYPE_LOG 0x01 #define NF_LOG_TYPE_ULOG 0x02 +#define NF_LOG_TYPE_RING 0x04 struct nf_loginfo { u_int8_t type; diff --git a/include/net/netfilter/xt_log_ring.h b/include/net/netfilter/xt_log_ring.h new file mode 100644 index 0000000..1c14ddf --- /dev/null +++ b/include/net/netfilter/xt_log_ring.h @@ -0,0 +1,24 @@ +#ifndef XT_LOG_RING_H +#define XT_LOG_RING_H + +struct xt_LOG_ring_ctx; +struct xt_LOG_ring_ctx *xt_LOG_ring_new_ctx(const char *name, size_t rb_size); +int xt_LOG_ring_add_record(const struct xt_LOG_ring_ctx *rctx, const char *buf, unsigned int len); +void xt_LOG_ring_get(struct xt_LOG_ring_ctx *ctx); +void xt_LOG_ring_put(struct xt_LOG_ring_ctx *ctx); +struct xt_LOG_ring_ctx *xt_LOG_ring_find_ctx(const char *name); + +#ifdef CONFIG_NETFILTER_XT_TARGET_LOG_RING +void xt_LOG_ring_exit(void); +int xt_LOG_ring_init(void); +#else +static inline void xt_LOG_ring_exit(void) +{ +} + +static inline int xt_LOG_ring_init(void) +{ + return 0; +} +#endif +#endif diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig index b895d8b..ac62599 100644 --- a/net/netfilter/Kconfig +++ b/net/netfilter/Kconfig @@ -533,6 +533,19 @@ config NETFILTER_XT_TARGET_LOG To compile it as a module, choose M here. If unsure, say N. +if NETFILTER_XT_TARGET_LOG + +config NETFILTER_XT_TARGET_LOG_RING + bool 'Ring buffer support' + default y + select RING_BUFFER + help + Using this it is possible to record packets into one or more ring buffers + instead of the kernel syslog. + Each ring buffer is represented as file in /proc/net/netfilter/xt_LOG_ring/. + +endif + config NETFILTER_XT_TARGET_MARK tristate '"MARK" target support' depends on NETFILTER_ADVANCED diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile index a28c2a6..e93de2a 100644 --- a/net/netfilter/Makefile +++ b/net/netfilter/Makefile @@ -58,6 +58,8 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_CT) += xt_CT.o obj-$(CONFIG_NETFILTER_XT_TARGET_DSCP) += xt_DSCP.o obj-$(CONFIG_NETFILTER_XT_TARGET_HL) += xt_HL.o obj-$(CONFIG_NETFILTER_XT_TARGET_LED) += xt_LED.o +xt_LOG-$(CONFIG_NETFILTER_XT_TARGET_LOG_RING) := xt_LOG_ring.o +xt_LOG-y += xt_LOG_core.o obj-$(CONFIG_NETFILTER_XT_TARGET_LOG) += xt_LOG.o obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o diff --git a/net/netfilter/xt_LOG.c b/net/netfilter/xt_LOG.c deleted file mode 100644 index baa084e..0000000 --- a/net/netfilter/xt_LOG.c +++ /dev/null @@ -1,921 +0,0 @@ -/* - * This is a module which is used for logging packets. - */ - -/* (C) 1999-2001 Paul `Rusty' Russell - * (C) 2002-2004 Netfilter Core Team - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 as - * published by the Free Software Foundation. - */ - -#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -#include -#include -#include -#include -#include -#include - -static struct nf_loginfo default_loginfo = { - .type = NF_LOG_TYPE_LOG, - .u = { - .log = { - .level = 5, - .logflags = NF_LOG_MASK, - }, - }, -}; - -static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb, - u8 proto, int fragment, unsigned int offset) -{ - struct udphdr _udph; - const struct udphdr *uh; - - if (proto == IPPROTO_UDP) - /* Max length: 10 "PROTO=UDP " */ - sb_add(m, "PROTO=UDP "); - else /* Max length: 14 "PROTO=UDPLITE " */ - sb_add(m, "PROTO=UDPLITE "); - - if (fragment) - goto out; - - /* Max length: 25 "INCOMPLETE [65535 bytes] " */ - uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); - if (uh == NULL) { - sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); - - return 1; - } - - /* Max length: 20 "SPT=65535 DPT=65535 " */ - sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest), - ntohs(uh->len)); - -out: - return 0; -} - -static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb, - u8 proto, int fragment, unsigned int offset, - unsigned int logflags) -{ - struct tcphdr _tcph; - const struct tcphdr *th; - - /* Max length: 10 "PROTO=TCP " */ - sb_add(m, "PROTO=TCP "); - - if (fragment) - return 0; - - /* Max length: 25 "INCOMPLETE [65535 bytes] " */ - th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); - if (th == NULL) { - sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); - return 1; - } - - /* Max length: 20 "SPT=65535 DPT=65535 " */ - sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest)); - /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ - if (logflags & XT_LOG_TCPSEQ) - sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq)); - - /* Max length: 13 "WINDOW=65535 " */ - sb_add(m, "WINDOW=%u ", ntohs(th->window)); - /* Max length: 9 "RES=0x3C " */ - sb_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & - TCP_RESERVED_BITS) >> 22)); - /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */ - if (th->cwr) - sb_add(m, "CWR "); - if (th->ece) - sb_add(m, "ECE "); - if (th->urg) - sb_add(m, "URG "); - if (th->ack) - sb_add(m, "ACK "); - if (th->psh) - sb_add(m, "PSH "); - if (th->rst) - sb_add(m, "RST "); - if (th->syn) - sb_add(m, "SYN "); - if (th->fin) - sb_add(m, "FIN "); - /* Max length: 11 "URGP=65535 " */ - sb_add(m, "URGP=%u ", ntohs(th->urg_ptr)); - - if ((logflags & XT_LOG_TCPOPT) && th->doff*4 > sizeof(struct tcphdr)) { - u_int8_t _opt[60 - sizeof(struct tcphdr)]; - const u_int8_t *op; - unsigned int i; - unsigned int optsize = th->doff*4 - sizeof(struct tcphdr); - - op = skb_header_pointer(skb, offset + sizeof(struct tcphdr), - optsize, _opt); - if (op == NULL) { - sb_add(m, "OPT (TRUNCATED)"); - return 1; - } - - /* Max length: 127 "OPT (" 15*4*2chars ") " */ - sb_add(m, "OPT ("); - for (i = 0; i < optsize; i++) - sb_add(m, "%02X", op[i]); - - sb_add(m, ") "); - } - - return 0; -} - -/* One level of recursion won't kill us */ -static void dump_ipv4_packet(struct sbuff *m, - const struct nf_loginfo *info, - const struct sk_buff *skb, - unsigned int iphoff) -{ - struct iphdr _iph; - const struct iphdr *ih; - unsigned int logflags; - - if (info->type == NF_LOG_TYPE_LOG) - logflags = info->u.log.logflags; - else - logflags = NF_LOG_MASK; - - ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); - if (ih == NULL) { - sb_add(m, "TRUNCATED"); - return; - } - - /* Important fields: - * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */ - /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */ - sb_add(m, "SRC=%pI4 DST=%pI4 ", - &ih->saddr, &ih->daddr); - - /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ - sb_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", - ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, - ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); - - /* Max length: 6 "CE DF MF " */ - if (ntohs(ih->frag_off) & IP_CE) - sb_add(m, "CE "); - if (ntohs(ih->frag_off) & IP_DF) - sb_add(m, "DF "); - if (ntohs(ih->frag_off) & IP_MF) - sb_add(m, "MF "); - - /* Max length: 11 "FRAG:65535 " */ - if (ntohs(ih->frag_off) & IP_OFFSET) - sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); - - if ((logflags & XT_LOG_IPOPT) && - ih->ihl * 4 > sizeof(struct iphdr)) { - const unsigned char *op; - unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; - unsigned int i, optsize; - - optsize = ih->ihl * 4 - sizeof(struct iphdr); - op = skb_header_pointer(skb, iphoff+sizeof(_iph), - optsize, _opt); - if (op == NULL) { - sb_add(m, "TRUNCATED"); - return; - } - - /* Max length: 127 "OPT (" 15*4*2chars ") " */ - sb_add(m, "OPT ("); - for (i = 0; i < optsize; i++) - sb_add(m, "%02X", op[i]); - sb_add(m, ") "); - } - - switch (ih->protocol) { - case IPPROTO_TCP: - if (dump_tcp_header(m, skb, ih->protocol, - ntohs(ih->frag_off) & IP_OFFSET, - iphoff+ih->ihl*4, logflags)) - return; - case IPPROTO_UDP: - case IPPROTO_UDPLITE: - if (dump_udp_header(m, skb, ih->protocol, - ntohs(ih->frag_off) & IP_OFFSET, - iphoff+ih->ihl*4)) - return; - case IPPROTO_ICMP: { - struct icmphdr _icmph; - const struct icmphdr *ich; - static const size_t required_len[NR_ICMP_TYPES+1] - = { [ICMP_ECHOREPLY] = 4, - [ICMP_DEST_UNREACH] - = 8 + sizeof(struct iphdr), - [ICMP_SOURCE_QUENCH] - = 8 + sizeof(struct iphdr), - [ICMP_REDIRECT] - = 8 + sizeof(struct iphdr), - [ICMP_ECHO] = 4, - [ICMP_TIME_EXCEEDED] - = 8 + sizeof(struct iphdr), - [ICMP_PARAMETERPROB] - = 8 + sizeof(struct iphdr), - [ICMP_TIMESTAMP] = 20, - [ICMP_TIMESTAMPREPLY] = 20, - [ICMP_ADDRESS] = 12, - [ICMP_ADDRESSREPLY] = 12 }; - - /* Max length: 11 "PROTO=ICMP " */ - sb_add(m, "PROTO=ICMP "); - - if (ntohs(ih->frag_off) & IP_OFFSET) - break; - - /* Max length: 25 "INCOMPLETE [65535 bytes] " */ - ich = skb_header_pointer(skb, iphoff + ih->ihl * 4, - sizeof(_icmph), &_icmph); - if (ich == NULL) { - sb_add(m, "INCOMPLETE [%u bytes] ", - skb->len - iphoff - ih->ihl*4); - break; - } - - /* Max length: 18 "TYPE=255 CODE=255 " */ - sb_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code); - - /* Max length: 25 "INCOMPLETE [65535 bytes] " */ - if (ich->type <= NR_ICMP_TYPES && - required_len[ich->type] && - skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) { - sb_add(m, "INCOMPLETE [%u bytes] ", - skb->len - iphoff - ih->ihl*4); - break; - } - - switch (ich->type) { - case ICMP_ECHOREPLY: - case ICMP_ECHO: - /* Max length: 19 "ID=65535 SEQ=65535 " */ - sb_add(m, "ID=%u SEQ=%u ", - ntohs(ich->un.echo.id), - ntohs(ich->un.echo.sequence)); - break; - - case ICMP_PARAMETERPROB: - /* Max length: 14 "PARAMETER=255 " */ - sb_add(m, "PARAMETER=%u ", - ntohl(ich->un.gateway) >> 24); - break; - case ICMP_REDIRECT: - /* Max length: 24 "GATEWAY=255.255.255.255 " */ - sb_add(m, "GATEWAY=%pI4 ", &ich->un.gateway); - /* Fall through */ - case ICMP_DEST_UNREACH: - case ICMP_SOURCE_QUENCH: - case ICMP_TIME_EXCEEDED: - /* Max length: 3+maxlen */ - if (!iphoff) { /* Only recurse once. */ - sb_add(m, "["); - dump_ipv4_packet(m, info, skb, - iphoff + ih->ihl*4+sizeof(_icmph)); - sb_add(m, "] "); - } - - /* Max length: 10 "MTU=65535 " */ - if (ich->type == ICMP_DEST_UNREACH && - ich->code == ICMP_FRAG_NEEDED) - sb_add(m, "MTU=%u ", ntohs(ich->un.frag.mtu)); - } - break; - } - /* Max Length */ - case IPPROTO_AH: { - struct ip_auth_hdr _ahdr; - const struct ip_auth_hdr *ah; - - if (ntohs(ih->frag_off) & IP_OFFSET) - break; - - /* Max length: 9 "PROTO=AH " */ - sb_add(m, "PROTO=AH "); - - /* Max length: 25 "INCOMPLETE [65535 bytes] " */ - ah = skb_header_pointer(skb, iphoff+ih->ihl*4, - sizeof(_ahdr), &_ahdr); - if (ah == NULL) { - sb_add(m, "INCOMPLETE [%u bytes] ", - skb->len - iphoff - ih->ihl*4); - break; - } - - /* Length: 15 "SPI=0xF1234567 " */ - sb_add(m, "SPI=0x%x ", ntohl(ah->spi)); - break; - } - case IPPROTO_ESP: { - struct ip_esp_hdr _esph; - const struct ip_esp_hdr *eh; - - /* Max length: 10 "PROTO=ESP " */ - sb_add(m, "PROTO=ESP "); - - if (ntohs(ih->frag_off) & IP_OFFSET) - break; - - /* Max length: 25 "INCOMPLETE [65535 bytes] " */ - eh = skb_header_pointer(skb, iphoff+ih->ihl*4, - sizeof(_esph), &_esph); - if (eh == NULL) { - sb_add(m, "INCOMPLETE [%u bytes] ", - skb->len - iphoff - ih->ihl*4); - break; - } - - /* Length: 15 "SPI=0xF1234567 " */ - sb_add(m, "SPI=0x%x ", ntohl(eh->spi)); - break; - } - /* Max length: 10 "PROTO 255 " */ - default: - sb_add(m, "PROTO=%u ", ih->protocol); - } - - /* Max length: 15 "UID=4294967295 " */ - if ((logflags & XT_LOG_UID) && !iphoff && skb->sk) { - read_lock_bh(&skb->sk->sk_callback_lock); - if (skb->sk->sk_socket && skb->sk->sk_socket->file) - sb_add(m, "UID=%u GID=%u ", - skb->sk->sk_socket->file->f_cred->fsuid, - skb->sk->sk_socket->file->f_cred->fsgid); - read_unlock_bh(&skb->sk->sk_callback_lock); - } - - /* Max length: 16 "MARK=0xFFFFFFFF " */ - if (!iphoff && skb->mark) - sb_add(m, "MARK=0x%x ", skb->mark); - - /* Proto Max log string length */ - /* IP: 40+46+6+11+127 = 230 */ - /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */ - /* UDP: 10+max(25,20) = 35 */ - /* UDPLITE: 14+max(25,20) = 39 */ - /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */ - /* ESP: 10+max(25)+15 = 50 */ - /* AH: 9+max(25)+15 = 49 */ - /* unknown: 10 */ - - /* (ICMP allows recursion one level deep) */ - /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */ - /* maxlen = 230+ 91 + 230 + 252 = 803 */ -} - -static void dump_ipv4_mac_header(struct sbuff *m, - const struct nf_loginfo *info, - const struct sk_buff *skb) -{ - struct net_device *dev = skb->dev; - unsigned int logflags = 0; - - if (info->type == NF_LOG_TYPE_LOG) - logflags = info->u.log.logflags; - - if (!(logflags & XT_LOG_MACDECODE)) - goto fallback; - - switch (dev->type) { - case ARPHRD_ETHER: - sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", - eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, - ntohs(eth_hdr(skb)->h_proto)); - return; - default: - break; - } - -fallback: - sb_add(m, "MAC="); - if (dev->hard_header_len && - skb->mac_header != skb->network_header) { - const unsigned char *p = skb_mac_header(skb); - unsigned int i; - - sb_add(m, "%02x", *p++); - for (i = 1; i < dev->hard_header_len; i++, p++) - sb_add(m, ":%02x", *p); - } - sb_add(m, " "); -} - -static void -log_packet_common(struct sbuff *m, - u_int8_t pf, - unsigned int hooknum, - const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct nf_loginfo *loginfo, - const char *prefix) -{ - sb_add(m, "<%d>%sIN=%s OUT=%s ", loginfo->u.log.level, - prefix, - in ? in->name : "", - out ? out->name : ""); -#ifdef CONFIG_BRIDGE_NETFILTER - if (skb->nf_bridge) { - const struct net_device *physindev; - const struct net_device *physoutdev; - - physindev = skb->nf_bridge->physindev; - if (physindev && in != physindev) - sb_add(m, "PHYSIN=%s ", physindev->name); - physoutdev = skb->nf_bridge->physoutdev; - if (physoutdev && out != physoutdev) - sb_add(m, "PHYSOUT=%s ", physoutdev->name); - } -#endif -} - - -static void -ipt_log_packet(u_int8_t pf, - unsigned int hooknum, - const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct nf_loginfo *loginfo, - const char *prefix) -{ - struct sbuff *m = sb_open(); - - if (!loginfo) - loginfo = &default_loginfo; - - log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); - - if (in != NULL) - dump_ipv4_mac_header(m, loginfo, skb); - - dump_ipv4_packet(m, loginfo, skb, 0); - - sb_close(m); -} - -#if IS_ENABLED(CONFIG_IPV6) -/* One level of recursion won't kill us */ -static void dump_ipv6_packet(struct sbuff *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_MASK; - - ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h); - if (ih == NULL) { - sb_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 " */ - sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr); - - /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ - sb_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) { - sb_add(m, "TRUNCATED"); - return; - } - - /* Max length: 48 "OPT (...) " */ - if (logflags & XT_LOG_IPOPT) - sb_add(m, "OPT ( "); - - switch (currenthdr) { - case IPPROTO_FRAGMENT: { - struct frag_hdr _fhdr; - const struct frag_hdr *fh; - - sb_add(m, "FRAG:"); - fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), - &_fhdr); - if (fh == NULL) { - sb_add(m, "TRUNCATED "); - return; - } - - /* Max length: 6 "65535 " */ - sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8); - - /* Max length: 11 "INCOMPLETE " */ - if (fh->frag_off & htons(0x0001)) - sb_add(m, "INCOMPLETE "); - - sb_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) - sb_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 " */ - sb_add(m, "AH "); - - if (fragment) { - sb_add(m, ")"); - return; - } - - ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), - &_ahdr); - if (ah == NULL) { - /* - * Max length: 26 "INCOMPLETE [65535 - * bytes] )" - */ - sb_add(m, "INCOMPLETE [%u bytes] )", - skb->len - ptr); - return; - } - - /* Length: 15 "SPI=0xF1234567 */ - sb_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 " */ - sb_add(m, "ESP "); - - if (fragment) { - sb_add(m, ")"); - return; - } - - /* - * Max length: 26 "INCOMPLETE [65535 bytes] )" - */ - eh = skb_header_pointer(skb, ptr, sizeof(_esph), - &_esph); - if (eh == NULL) { - sb_add(m, "INCOMPLETE [%u bytes] )", - skb->len - ptr); - return; - } - - /* Length: 16 "SPI=0xF1234567 )" */ - sb_add(m, "SPI=0x%x )", ntohl(eh->spi)); - - } - return; - default: - /* Max length: 20 "Unknown Ext Hdr 255" */ - sb_add(m, "Unknown Ext Hdr %u", currenthdr); - return; - } - if (logflags & XT_LOG_IPOPT) - sb_add(m, ") "); - - currenthdr = hp->nexthdr; - ptr += hdrlen; - } - - switch (currenthdr) { - case IPPROTO_TCP: - if (dump_tcp_header(m, skb, currenthdr, fragment, ptr, - logflags)) - return; - case IPPROTO_UDP: - case IPPROTO_UDPLITE: - if (dump_udp_header(m, skb, currenthdr, fragment, ptr)) - return; - case IPPROTO_ICMPV6: { - struct icmp6hdr _icmp6h; - const struct icmp6hdr *ic; - - /* Max length: 13 "PROTO=ICMPv6 " */ - sb_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) { - sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr); - return; - } - - /* Max length: 18 "TYPE=255 CODE=255 " */ - sb_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 " */ - sb_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 " */ - sb_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) { - sb_add(m, "["); - dump_ipv6_packet(m, info, skb, - ptr + sizeof(_icmp6h), 0); - sb_add(m, "] "); - } - - /* Max length: 10 "MTU=65535 " */ - if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) - sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu)); - } - break; - } - /* Max length: 10 "PROTO=255 " */ - default: - sb_add(m, "PROTO=%u ", currenthdr); - } - - /* Max length: 15 "UID=4294967295 " */ - if ((logflags & XT_LOG_UID) && recurse && skb->sk) { - read_lock_bh(&skb->sk->sk_callback_lock); - if (skb->sk->sk_socket && skb->sk->sk_socket->file) - sb_add(m, "UID=%u GID=%u ", - skb->sk->sk_socket->file->f_cred->fsuid, - skb->sk->sk_socket->file->f_cred->fsgid); - read_unlock_bh(&skb->sk->sk_callback_lock); - } - - /* Max length: 16 "MARK=0xFFFFFFFF " */ - if (!recurse && skb->mark) - sb_add(m, "MARK=0x%x ", skb->mark); -} - -static void dump_ipv6_mac_header(struct sbuff *m, - const struct nf_loginfo *info, - const struct sk_buff *skb) -{ - struct net_device *dev = skb->dev; - unsigned int logflags = 0; - - if (info->type == NF_LOG_TYPE_LOG) - logflags = info->u.log.logflags; - - if (!(logflags & XT_LOG_MACDECODE)) - goto fallback; - - switch (dev->type) { - case ARPHRD_ETHER: - sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", - eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, - ntohs(eth_hdr(skb)->h_proto)); - return; - default: - break; - } - -fallback: - sb_add(m, "MAC="); - if (dev->hard_header_len && - skb->mac_header != skb->network_header) { - const unsigned char *p = skb_mac_header(skb); - unsigned int 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) { - sb_add(m, "%02x", *p++); - for (i = 1; i < len; i++) - sb_add(m, ":%02x", *p++); - } - sb_add(m, " "); - - if (dev->type == ARPHRD_SIT) { - const struct iphdr *iph = - (struct iphdr *)skb_mac_header(skb); - sb_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr, - &iph->daddr); - } - } else - sb_add(m, " "); -} - -static void -ip6t_log_packet(u_int8_t pf, - unsigned int hooknum, - const struct sk_buff *skb, - const struct net_device *in, - const struct net_device *out, - const struct nf_loginfo *loginfo, - const char *prefix) -{ - struct sbuff *m = sb_open(); - - if (!loginfo) - loginfo = &default_loginfo; - - log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); - - if (in != NULL) - dump_ipv6_mac_header(m, loginfo, skb); - - dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1); - - sb_close(m); -} -#endif - -static unsigned int -log_tg(struct sk_buff *skb, const struct xt_action_param *par) -{ - const struct xt_log_info *loginfo = par->targinfo; - struct nf_loginfo li; - - li.type = NF_LOG_TYPE_LOG; - li.u.log.level = loginfo->level; - li.u.log.logflags = loginfo->logflags; - - if (par->family == NFPROTO_IPV4) - ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, - par->out, &li, loginfo->prefix); -#if IS_ENABLED(CONFIG_IPV6) - else if (par->family == NFPROTO_IPV6) - ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, - par->out, &li, loginfo->prefix); -#endif - else - BUG(); - - return XT_CONTINUE; -} - -static int log_tg_check(const struct xt_tgchk_param *par) -{ - const struct xt_log_info *loginfo = par->targinfo; - - if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6) - return -EINVAL; - - if (loginfo->level >= 8) { - pr_debug("level %u >= 8\n", loginfo->level); - return -EINVAL; - } - - if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') { - pr_debug("prefix is not null-terminated\n"); - return -EINVAL; - } - - return 0; -} - -static struct xt_target log_tg_regs[] __read_mostly = { - { - .name = "LOG", - .family = NFPROTO_IPV4, - .target = log_tg, - .targetsize = sizeof(struct xt_log_info), - .checkentry = log_tg_check, - .me = THIS_MODULE, - }, -#if IS_ENABLED(CONFIG_IPV6) - { - .name = "LOG", - .family = NFPROTO_IPV6, - .target = log_tg, - .targetsize = sizeof(struct xt_log_info), - .checkentry = log_tg_check, - .me = THIS_MODULE, - }, -#endif -}; - -static struct nf_logger ipt_log_logger __read_mostly = { - .name = "ipt_LOG", - .logfn = &ipt_log_packet, - .me = THIS_MODULE, -}; - -#if IS_ENABLED(CONFIG_IPV6) -static struct nf_logger ip6t_log_logger __read_mostly = { - .name = "ip6t_LOG", - .logfn = &ip6t_log_packet, - .me = THIS_MODULE, -}; -#endif - -static int __init log_tg_init(void) -{ - int ret; - - ret = xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); - if (ret < 0) - return ret; - - nf_log_register(NFPROTO_IPV4, &ipt_log_logger); -#if IS_ENABLED(CONFIG_IPV6) - nf_log_register(NFPROTO_IPV6, &ip6t_log_logger); -#endif - return 0; -} - -static void __exit log_tg_exit(void) -{ - nf_log_unregister(&ipt_log_logger); -#if IS_ENABLED(CONFIG_IPV6) - nf_log_unregister(&ip6t_log_logger); -#endif - xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); -} - -module_init(log_tg_init); -module_exit(log_tg_exit); - -MODULE_LICENSE("GPL"); -MODULE_AUTHOR("Netfilter Core Team "); -MODULE_AUTHOR("Jan Rekorajski "); -MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging"); -MODULE_ALIAS("ipt_LOG"); -MODULE_ALIAS("ip6t_LOG"); diff --git a/net/netfilter/xt_LOG_core.c b/net/netfilter/xt_LOG_core.c new file mode 100644 index 0000000..4c6abca --- /dev/null +++ b/net/netfilter/xt_LOG_core.c @@ -0,0 +1,1102 @@ +/* + * This is a module which is used for logging packets. + */ + +/* (C) 1999-2001 Paul `Rusty' Russell + * (C) 2002-2004 Netfilter Core Team + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Netfilter Core Team "); +MODULE_AUTHOR("Jan Rekorajski "); +MODULE_AUTHOR("Richard Weinberger "); +MODULE_DESCRIPTION("Xtables: IPv4/IPv6 packet logging"); +MODULE_ALIAS("ipt_LOG"); +MODULE_ALIAS("ip6t_LOG"); + +static struct nf_loginfo default_loginfo = { + .type = NF_LOG_TYPE_LOG, + .u = { + .log = { + .level = 5, + .logflags = NF_LOG_MASK, + }, + }, +}; + +static int dump_udp_header(struct sbuff *m, const struct sk_buff *skb, + u8 proto, int fragment, unsigned int offset) +{ + struct udphdr _udph; + const struct udphdr *uh; + + if (proto == IPPROTO_UDP) + /* Max length: 10 "PROTO=UDP " */ + sb_add(m, "PROTO=UDP "); + else /* Max length: 14 "PROTO=UDPLITE " */ + sb_add(m, "PROTO=UDPLITE "); + + if (fragment) + goto out; + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph); + if (uh == NULL) { + sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); + + return 1; + } + + /* Max length: 20 "SPT=65535 DPT=65535 " */ + sb_add(m, "SPT=%u DPT=%u LEN=%u ", ntohs(uh->source), ntohs(uh->dest), + ntohs(uh->len)); + +out: + return 0; +} + +static int dump_tcp_header(struct sbuff *m, const struct sk_buff *skb, + u8 proto, int fragment, unsigned int offset, + unsigned int logflags) +{ + struct tcphdr _tcph; + const struct tcphdr *th; + + /* Max length: 10 "PROTO=TCP " */ + sb_add(m, "PROTO=TCP "); + + if (fragment) + return 0; + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph); + if (th == NULL) { + sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - offset); + return 1; + } + + /* Max length: 20 "SPT=65535 DPT=65535 " */ + sb_add(m, "SPT=%u DPT=%u ", ntohs(th->source), ntohs(th->dest)); + /* Max length: 30 "SEQ=4294967295 ACK=4294967295 " */ + if (logflags & XT_LOG_TCPSEQ) + sb_add(m, "SEQ=%u ACK=%u ", ntohl(th->seq), ntohl(th->ack_seq)); + + /* Max length: 13 "WINDOW=65535 " */ + sb_add(m, "WINDOW=%u ", ntohs(th->window)); + /* Max length: 9 "RES=0x3C " */ + sb_add(m, "RES=0x%02x ", (u_int8_t)(ntohl(tcp_flag_word(th) & + TCP_RESERVED_BITS) >> 22)); + /* Max length: 32 "CWR ECE URG ACK PSH RST SYN FIN " */ + if (th->cwr) + sb_add(m, "CWR "); + if (th->ece) + sb_add(m, "ECE "); + if (th->urg) + sb_add(m, "URG "); + if (th->ack) + sb_add(m, "ACK "); + if (th->psh) + sb_add(m, "PSH "); + if (th->rst) + sb_add(m, "RST "); + if (th->syn) + sb_add(m, "SYN "); + if (th->fin) + sb_add(m, "FIN "); + /* Max length: 11 "URGP=65535 " */ + sb_add(m, "URGP=%u ", ntohs(th->urg_ptr)); + + if ((logflags & XT_LOG_TCPOPT) && th->doff*4 > sizeof(struct tcphdr)) { + u_int8_t _opt[60 - sizeof(struct tcphdr)]; + const u_int8_t *op; + unsigned int i; + unsigned int optsize = th->doff*4 - sizeof(struct tcphdr); + + op = skb_header_pointer(skb, offset + sizeof(struct tcphdr), + optsize, _opt); + if (op == NULL) { + sb_add(m, "OPT (TRUNCATED)"); + return 1; + } + + /* Max length: 127 "OPT (" 15*4*2chars ") " */ + sb_add(m, "OPT ("); + for (i = 0; i < optsize; i++) + sb_add(m, "%02X", op[i]); + + sb_add(m, ") "); + } + + return 0; +} + +/* One level of recursion won't kill us */ +static void dump_ipv4_packet(struct sbuff *m, + const struct nf_loginfo *info, + const struct sk_buff *skb, + unsigned int iphoff) +{ + struct iphdr _iph; + const struct iphdr *ih; + unsigned int logflags; + + if (info->type == NF_LOG_TYPE_LOG || info->type == NF_LOG_TYPE_RING) + logflags = info->u.log.logflags; + else + logflags = NF_LOG_MASK; + + ih = skb_header_pointer(skb, iphoff, sizeof(_iph), &_iph); + if (ih == NULL) { + sb_add(m, "TRUNCATED"); + return; + } + + /* Important fields: + * TOS, len, DF/MF, fragment offset, TTL, src, dst, options. */ + /* Max length: 40 "SRC=255.255.255.255 DST=255.255.255.255 " */ + sb_add(m, "SRC=%pI4 DST=%pI4 ", + &ih->saddr, &ih->daddr); + + /* Max length: 46 "LEN=65535 TOS=0xFF PREC=0xFF TTL=255 ID=65535 " */ + sb_add(m, "LEN=%u TOS=0x%02X PREC=0x%02X TTL=%u ID=%u ", + ntohs(ih->tot_len), ih->tos & IPTOS_TOS_MASK, + ih->tos & IPTOS_PREC_MASK, ih->ttl, ntohs(ih->id)); + + /* Max length: 6 "CE DF MF " */ + if (ntohs(ih->frag_off) & IP_CE) + sb_add(m, "CE "); + if (ntohs(ih->frag_off) & IP_DF) + sb_add(m, "DF "); + if (ntohs(ih->frag_off) & IP_MF) + sb_add(m, "MF "); + + /* Max length: 11 "FRAG:65535 " */ + if (ntohs(ih->frag_off) & IP_OFFSET) + sb_add(m, "FRAG:%u ", ntohs(ih->frag_off) & IP_OFFSET); + + if ((logflags & XT_LOG_IPOPT) && + ih->ihl * 4 > sizeof(struct iphdr)) { + const unsigned char *op; + unsigned char _opt[4 * 15 - sizeof(struct iphdr)]; + unsigned int i, optsize; + + optsize = ih->ihl * 4 - sizeof(struct iphdr); + op = skb_header_pointer(skb, iphoff+sizeof(_iph), + optsize, _opt); + if (op == NULL) { + sb_add(m, "TRUNCATED"); + return; + } + + /* Max length: 127 "OPT (" 15*4*2chars ") " */ + sb_add(m, "OPT ("); + for (i = 0; i < optsize; i++) + sb_add(m, "%02X", op[i]); + sb_add(m, ") "); + } + + switch (ih->protocol) { + case IPPROTO_TCP: + if (dump_tcp_header(m, skb, ih->protocol, + ntohs(ih->frag_off) & IP_OFFSET, + iphoff+ih->ihl*4, logflags)) + return; + case IPPROTO_UDP: + case IPPROTO_UDPLITE: + if (dump_udp_header(m, skb, ih->protocol, + ntohs(ih->frag_off) & IP_OFFSET, + iphoff+ih->ihl*4)) + return; + case IPPROTO_ICMP: { + struct icmphdr _icmph; + const struct icmphdr *ich; + static const size_t required_len[NR_ICMP_TYPES+1] + = { [ICMP_ECHOREPLY] = 4, + [ICMP_DEST_UNREACH] + = 8 + sizeof(struct iphdr), + [ICMP_SOURCE_QUENCH] + = 8 + sizeof(struct iphdr), + [ICMP_REDIRECT] + = 8 + sizeof(struct iphdr), + [ICMP_ECHO] = 4, + [ICMP_TIME_EXCEEDED] + = 8 + sizeof(struct iphdr), + [ICMP_PARAMETERPROB] + = 8 + sizeof(struct iphdr), + [ICMP_TIMESTAMP] = 20, + [ICMP_TIMESTAMPREPLY] = 20, + [ICMP_ADDRESS] = 12, + [ICMP_ADDRESSREPLY] = 12 }; + + /* Max length: 11 "PROTO=ICMP " */ + sb_add(m, "PROTO=ICMP "); + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + ich = skb_header_pointer(skb, iphoff + ih->ihl * 4, + sizeof(_icmph), &_icmph); + if (ich == NULL) { + sb_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + /* Max length: 18 "TYPE=255 CODE=255 " */ + sb_add(m, "TYPE=%u CODE=%u ", ich->type, ich->code); + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + if (ich->type <= NR_ICMP_TYPES && + required_len[ich->type] && + skb->len-iphoff-ih->ihl*4 < required_len[ich->type]) { + sb_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + switch (ich->type) { + case ICMP_ECHOREPLY: + case ICMP_ECHO: + /* Max length: 19 "ID=65535 SEQ=65535 " */ + sb_add(m, "ID=%u SEQ=%u ", + ntohs(ich->un.echo.id), + ntohs(ich->un.echo.sequence)); + break; + + case ICMP_PARAMETERPROB: + /* Max length: 14 "PARAMETER=255 " */ + sb_add(m, "PARAMETER=%u ", + ntohl(ich->un.gateway) >> 24); + break; + case ICMP_REDIRECT: + /* Max length: 24 "GATEWAY=255.255.255.255 " */ + sb_add(m, "GATEWAY=%pI4 ", &ich->un.gateway); + /* Fall through */ + case ICMP_DEST_UNREACH: + case ICMP_SOURCE_QUENCH: + case ICMP_TIME_EXCEEDED: + /* Max length: 3+maxlen */ + if (!iphoff) { /* Only recurse once. */ + sb_add(m, "["); + dump_ipv4_packet(m, info, skb, + iphoff + ih->ihl*4+sizeof(_icmph)); + sb_add(m, "] "); + } + + /* Max length: 10 "MTU=65535 " */ + if (ich->type == ICMP_DEST_UNREACH && + ich->code == ICMP_FRAG_NEEDED) + sb_add(m, "MTU=%u ", ntohs(ich->un.frag.mtu)); + } + break; + } + /* Max Length */ + case IPPROTO_AH: { + struct ip_auth_hdr _ahdr; + const struct ip_auth_hdr *ah; + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + /* Max length: 9 "PROTO=AH " */ + sb_add(m, "PROTO=AH "); + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + ah = skb_header_pointer(skb, iphoff+ih->ihl*4, + sizeof(_ahdr), &_ahdr); + if (ah == NULL) { + sb_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + /* Length: 15 "SPI=0xF1234567 " */ + sb_add(m, "SPI=0x%x ", ntohl(ah->spi)); + break; + } + case IPPROTO_ESP: { + struct ip_esp_hdr _esph; + const struct ip_esp_hdr *eh; + + /* Max length: 10 "PROTO=ESP " */ + sb_add(m, "PROTO=ESP "); + + if (ntohs(ih->frag_off) & IP_OFFSET) + break; + + /* Max length: 25 "INCOMPLETE [65535 bytes] " */ + eh = skb_header_pointer(skb, iphoff+ih->ihl*4, + sizeof(_esph), &_esph); + if (eh == NULL) { + sb_add(m, "INCOMPLETE [%u bytes] ", + skb->len - iphoff - ih->ihl*4); + break; + } + + /* Length: 15 "SPI=0xF1234567 " */ + sb_add(m, "SPI=0x%x ", ntohl(eh->spi)); + break; + } + /* Max length: 10 "PROTO 255 " */ + default: + sb_add(m, "PROTO=%u ", ih->protocol); + } + + /* Max length: 15 "UID=4294967295 " */ + if ((logflags & XT_LOG_UID) && !iphoff && skb->sk) { + read_lock_bh(&skb->sk->sk_callback_lock); + if (skb->sk->sk_socket && skb->sk->sk_socket->file) + sb_add(m, "UID=%u GID=%u ", + skb->sk->sk_socket->file->f_cred->fsuid, + skb->sk->sk_socket->file->f_cred->fsgid); + read_unlock_bh(&skb->sk->sk_callback_lock); + } + + /* Max length: 16 "MARK=0xFFFFFFFF " */ + if (!iphoff && skb->mark) + sb_add(m, "MARK=0x%x ", skb->mark); + + /* Proto Max log string length */ + /* IP: 40+46+6+11+127 = 230 */ + /* TCP: 10+max(25,20+30+13+9+32+11+127) = 252 */ + /* UDP: 10+max(25,20) = 35 */ + /* UDPLITE: 14+max(25,20) = 39 */ + /* ICMP: 11+max(25, 18+25+max(19,14,24+3+n+10,3+n+10)) = 91+n */ + /* ESP: 10+max(25)+15 = 50 */ + /* AH: 9+max(25)+15 = 49 */ + /* unknown: 10 */ + + /* (ICMP allows recursion one level deep) */ + /* maxlen = IP + ICMP + IP + max(TCP,UDP,ICMP,unknown) */ + /* maxlen = 230+ 91 + 230 + 252 = 803 */ +} + +static void dump_ipv4_mac_header(struct sbuff *m, + const struct nf_loginfo *info, + const struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + unsigned int logflags = 0; + + if (info->type == NF_LOG_TYPE_LOG || info->type == NF_LOG_TYPE_RING) + logflags = info->u.log.logflags; + + if (!(logflags & XT_LOG_MACDECODE)) + goto fallback; + + switch (dev->type) { + case ARPHRD_ETHER: + sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", + eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, + ntohs(eth_hdr(skb)->h_proto)); + return; + default: + break; + } + +fallback: + sb_add(m, "MAC="); + if (dev->hard_header_len && + skb->mac_header != skb->network_header) { + const unsigned char *p = skb_mac_header(skb); + unsigned int i; + + sb_add(m, "%02x", *p++); + for (i = 1; i < dev->hard_header_len; i++, p++) + sb_add(m, ":%02x", *p); + } + sb_add(m, " "); +} + +static void +log_packet_common(struct sbuff *m, + u_int8_t pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + if (loginfo->type == NF_LOG_TYPE_LOG) + sb_add(m, "<%d>", loginfo->u.log.level); + + if (loginfo->u.log.logflags & XT_LOG_ADD_TIMESTAMP) { + static struct timespec tv; + unsigned int msec; + + getnstimeofday(&tv); + msec = tv.tv_nsec; + do_div(msec, 1000000); + sb_add(m, "TIMESTAMP=%li.%03li ", tv.tv_sec, msec); + } + + sb_add(m, "%sIN=%s OUT=%s ", prefix, in ? in->name : "", + out ? out->name : ""); +#ifdef CONFIG_BRIDGE_NETFILTER + if (skb->nf_bridge) { + const struct net_device *physindev; + const struct net_device *physoutdev; + + physindev = skb->nf_bridge->physindev; + if (physindev && in != physindev) + sb_add(m, "PHYSIN=%s ", physindev->name); + physoutdev = skb->nf_bridge->physoutdev; + if (physoutdev && out != physoutdev) + sb_add(m, "PHYSOUT=%s ", physoutdev->name); + } +#endif +} + + +static struct sbuff *ipt_log_packet(u_int8_t pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + struct sbuff *m = sb_open(); + + if (!loginfo) + loginfo = &default_loginfo; + + log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); + + if (in != NULL) + dump_ipv4_mac_header(m, loginfo, skb); + + dump_ipv4_packet(m, loginfo, skb, 0); + + return m; +} + +static void ipt_log_packet_logger(u_int8_t pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + struct sbuff *m = ipt_log_packet(pf, hooknum, skb, in, out, loginfo, prefix); + + sb_close(m); +} + +#if IS_ENABLED(CONFIG_IPV6) +/* One level of recursion won't kill us */ +static void dump_ipv6_packet(struct sbuff *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 || info->type == NF_LOG_TYPE_RING) + logflags = info->u.log.logflags; + else + logflags = NF_LOG_MASK; + + ih = skb_header_pointer(skb, ip6hoff, sizeof(_ip6h), &_ip6h); + if (ih == NULL) { + sb_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 " */ + sb_add(m, "SRC=%pI6 DST=%pI6 ", &ih->saddr, &ih->daddr); + + /* Max length: 44 "LEN=65535 TC=255 HOPLIMIT=255 FLOWLBL=FFFFF " */ + sb_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) { + sb_add(m, "TRUNCATED"); + return; + } + + /* Max length: 48 "OPT (...) " */ + if (logflags & XT_LOG_IPOPT) + sb_add(m, "OPT ( "); + + switch (currenthdr) { + case IPPROTO_FRAGMENT: { + struct frag_hdr _fhdr; + const struct frag_hdr *fh; + + sb_add(m, "FRAG:"); + fh = skb_header_pointer(skb, ptr, sizeof(_fhdr), + &_fhdr); + if (fh == NULL) { + sb_add(m, "TRUNCATED "); + return; + } + + /* Max length: 6 "65535 " */ + sb_add(m, "%u ", ntohs(fh->frag_off) & 0xFFF8); + + /* Max length: 11 "INCOMPLETE " */ + if (fh->frag_off & htons(0x0001)) + sb_add(m, "INCOMPLETE "); + + sb_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) + sb_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 " */ + sb_add(m, "AH "); + + if (fragment) { + sb_add(m, ")"); + return; + } + + ah = skb_header_pointer(skb, ptr, sizeof(_ahdr), + &_ahdr); + if (ah == NULL) { + /* + * Max length: 26 "INCOMPLETE [65535 + * bytes] )" + */ + sb_add(m, "INCOMPLETE [%u bytes] )", + skb->len - ptr); + return; + } + + /* Length: 15 "SPI=0xF1234567 */ + sb_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 " */ + sb_add(m, "ESP "); + + if (fragment) { + sb_add(m, ")"); + return; + } + + /* + * Max length: 26 "INCOMPLETE [65535 bytes] )" + */ + eh = skb_header_pointer(skb, ptr, sizeof(_esph), + &_esph); + if (eh == NULL) { + sb_add(m, "INCOMPLETE [%u bytes] )", + skb->len - ptr); + return; + } + + /* Length: 16 "SPI=0xF1234567 )" */ + sb_add(m, "SPI=0x%x )", ntohl(eh->spi)); + + } + return; + default: + /* Max length: 20 "Unknown Ext Hdr 255" */ + sb_add(m, "Unknown Ext Hdr %u", currenthdr); + return; + } + if (logflags & XT_LOG_IPOPT) + sb_add(m, ") "); + + currenthdr = hp->nexthdr; + ptr += hdrlen; + } + + switch (currenthdr) { + case IPPROTO_TCP: + if (dump_tcp_header(m, skb, currenthdr, fragment, ptr, + logflags)) + return; + case IPPROTO_UDP: + case IPPROTO_UDPLITE: + if (dump_udp_header(m, skb, currenthdr, fragment, ptr)) + return; + case IPPROTO_ICMPV6: { + struct icmp6hdr _icmp6h; + const struct icmp6hdr *ic; + + /* Max length: 13 "PROTO=ICMPv6 " */ + sb_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) { + sb_add(m, "INCOMPLETE [%u bytes] ", skb->len - ptr); + return; + } + + /* Max length: 18 "TYPE=255 CODE=255 " */ + sb_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 " */ + sb_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 " */ + sb_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) { + sb_add(m, "["); + dump_ipv6_packet(m, info, skb, + ptr + sizeof(_icmp6h), 0); + sb_add(m, "] "); + } + + /* Max length: 10 "MTU=65535 " */ + if (ic->icmp6_type == ICMPV6_PKT_TOOBIG) + sb_add(m, "MTU=%u ", ntohl(ic->icmp6_mtu)); + } + break; + } + /* Max length: 10 "PROTO=255 " */ + default: + sb_add(m, "PROTO=%u ", currenthdr); + } + + /* Max length: 15 "UID=4294967295 " */ + if ((logflags & XT_LOG_UID) && recurse && skb->sk) { + read_lock_bh(&skb->sk->sk_callback_lock); + if (skb->sk->sk_socket && skb->sk->sk_socket->file) + sb_add(m, "UID=%u GID=%u ", + skb->sk->sk_socket->file->f_cred->fsuid, + skb->sk->sk_socket->file->f_cred->fsgid); + read_unlock_bh(&skb->sk->sk_callback_lock); + } + + /* Max length: 16 "MARK=0xFFFFFFFF " */ + if (!recurse && skb->mark) + sb_add(m, "MARK=0x%x ", skb->mark); +} + +static void dump_ipv6_mac_header(struct sbuff *m, + const struct nf_loginfo *info, + const struct sk_buff *skb) +{ + struct net_device *dev = skb->dev; + unsigned int logflags = 0; + + if (info->type == NF_LOG_TYPE_LOG || info->type == NF_LOG_TYPE_RING) + logflags = info->u.log.logflags; + + if (!(logflags & XT_LOG_MACDECODE)) + goto fallback; + + switch (dev->type) { + case ARPHRD_ETHER: + sb_add(m, "MACSRC=%pM MACDST=%pM MACPROTO=%04x ", + eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, + ntohs(eth_hdr(skb)->h_proto)); + return; + default: + break; + } + +fallback: + sb_add(m, "MAC="); + if (dev->hard_header_len && + skb->mac_header != skb->network_header) { + const unsigned char *p = skb_mac_header(skb); + unsigned int 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) { + sb_add(m, "%02x", *p++); + for (i = 1; i < len; i++) + sb_add(m, ":%02x", *p++); + } + sb_add(m, " "); + + if (dev->type == ARPHRD_SIT) { + const struct iphdr *iph = + (struct iphdr *)skb_mac_header(skb); + sb_add(m, "TUNNEL=%pI4->%pI4 ", &iph->saddr, + &iph->daddr); + } + } else + sb_add(m, " "); +} + +static struct sbuff *ip6t_log_packet(u_int8_t pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + struct sbuff *m = sb_open(); + + if (!loginfo) + loginfo = &default_loginfo; + + log_packet_common(m, pf, hooknum, skb, in, out, loginfo, prefix); + + if (in != NULL) + dump_ipv6_mac_header(m, loginfo, skb); + + dump_ipv6_packet(m, loginfo, skb, skb_network_offset(skb), 1); + + return m; +} + +static void ip6t_log_packet_logger(u_int8_t pf, + unsigned int hooknum, + const struct sk_buff *skb, + const struct net_device *in, + const struct net_device *out, + const struct nf_loginfo *loginfo, + const char *prefix) +{ + struct sbuff *m = ip6t_log_packet(pf, hooknum, skb, in, out, loginfo, prefix); + + sb_close(m); +} +#endif + +static unsigned int +log_tg(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct xt_log_info *loginfo = par->targinfo; + struct nf_loginfo li; + struct sbuff *m; + + li.type = NF_LOG_TYPE_LOG; + li.u.log.level = loginfo->level; + li.u.log.logflags = loginfo->logflags; + + if (par->family == NFPROTO_IPV4) + m = ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, + par->out, &li, loginfo->prefix); +#if IS_ENABLED(CONFIG_IPV6) + else if (par->family == NFPROTO_IPV6) + m = ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, + par->out, &li, loginfo->prefix); +#endif + else + BUG(); + + sb_close(m); + + return XT_CONTINUE; +} + +static int log_tg_check(const struct xt_tgchk_param *par) +{ + const struct xt_log_info *loginfo = par->targinfo; + + if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6) + return -EINVAL; + + if (loginfo->level >= 8) { + pr_debug("level %u >= 8\n", loginfo->level); + return -EINVAL; + } + + if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') { + pr_debug("prefix is not null-terminated\n"); + return -EINVAL; + } + + return 0; +} + +static unsigned int +log_tg_v1(struct sk_buff *skb, const struct xt_action_param *par) +{ + const struct xt_log_info_v1 *loginfo = par->targinfo; + struct nf_loginfo li; + struct sbuff *m; + +#ifdef CONFIG_NETFILTER_XT_TARGET_LOG_RING + if (loginfo->ring_size) + li.type = NF_LOG_TYPE_RING; + else +#endif + li.type = NF_LOG_TYPE_LOG; + + li.u.log.level = loginfo->level; + li.u.log.logflags = loginfo->logflags; + + if (par->family == NFPROTO_IPV4) + m = ipt_log_packet(NFPROTO_IPV4, par->hooknum, skb, par->in, + par->out, &li, loginfo->prefix); +#if IS_ENABLED(CONFIG_IPV6) + else if (par->family == NFPROTO_IPV6) + m = ip6t_log_packet(NFPROTO_IPV6, par->hooknum, skb, par->in, + par->out, &li, loginfo->prefix); +#endif + else + BUG(); + +#ifdef CONFIG_NETFILTER_XT_TARGET_LOG_RING + if (loginfo->ring_size) { + sb_add(m, "\n"); + xt_LOG_ring_add_record(loginfo->rctx, m->buf, m->count); + __sb_close(m, 0); + } + else +#endif + sb_close(m); + + return XT_CONTINUE; +} + +static int log_tg_check_v1(const struct xt_tgchk_param *par) +{ + struct xt_log_info_v1 *loginfo = par->targinfo; + + if (par->family != NFPROTO_IPV4 && par->family != NFPROTO_IPV6) + return -EINVAL; + + if (loginfo->level >= 8) { + pr_debug("level %u >= 8\n", loginfo->level); + return -EINVAL; + } + + if (loginfo->prefix[sizeof(loginfo->prefix)-1] != '\0') { + pr_debug("prefix is not null-terminated\n"); + return -EINVAL; + } + + /* a non-empty ring_size indicates that we're using ring_buffer */ + if (loginfo->ring_size) { +#ifdef CONFIG_NETFILTER_XT_TARGET_LOG_RING + int i; + struct xt_LOG_ring_ctx *rctx; + + if (loginfo->ring_name[sizeof(loginfo->ring_name)-1] != '\0') { + pr_debug("ring_name is not null-terminated\n"); + return -EINVAL; + } + + if (!loginfo->ring_name[0]) { + pr_debug("ring_name is empty\n"); + return -EINVAL; + } + + for (i = 0; i < strlen(loginfo->ring_name); i++) { + if (!isalnum(loginfo->ring_name[i])) { + pr_debug("ring_name contains " + "a non-alphanumeric character\n"); + return -EINVAL; + } + } + + rctx = xt_LOG_ring_find_ctx(loginfo->ring_name); + if (!rctx) { + rctx = xt_LOG_ring_new_ctx(loginfo->ring_name, + loginfo->ring_size); + if (IS_ERR(rctx)) + return PTR_ERR(rctx); + } + + xt_LOG_ring_get(rctx); + loginfo->rctx = rctx; +#else + pr_debug("Sorry, this kernel was built without CONFIG_NETFILTER_XT_TARGET_LOG_RING\n"); + return -EINVAL; +#endif + } + + return 0; +} + +static void log_tg_destroy_v1(const struct xt_tgdtor_param *par) +{ +#ifdef CONFIG_NETFILTER_XT_TARGET_LOG_RING + const struct xt_log_info_v1 *loginfo = par->targinfo; + struct xt_LOG_ring_ctx *rctx = loginfo->rctx; + + if (loginfo->ring_size) + xt_LOG_ring_put(rctx); +#endif +} + +static struct xt_target log_tg_regs[] __read_mostly = { + { + .name = "LOG", + .family = NFPROTO_IPV4, + .revision = 0, + .target = log_tg, + .targetsize = sizeof(struct xt_log_info), + .checkentry = log_tg_check, + .me = THIS_MODULE, + }, + { + .name = "LOG", + .family = NFPROTO_IPV4, + .revision = 1, + .target = log_tg_v1, + .targetsize = sizeof(struct xt_log_info_v1), + .checkentry = log_tg_check_v1, + .destroy = log_tg_destroy_v1, + .me = THIS_MODULE, + }, +#if IS_ENABLED(CONFIG_IPV6) + { + .name = "LOG", + .family = NFPROTO_IPV6, + .revision = 0, + .target = log_tg, + .targetsize = sizeof(struct xt_log_info), + .checkentry = log_tg_check, + .me = THIS_MODULE, + }, + { + .name = "LOG", + .family = NFPROTO_IPV6, + .revision = 1, + .target = log_tg_v1, + .targetsize = sizeof(struct xt_log_info_v1), + .checkentry = log_tg_check_v1, + .destroy = log_tg_destroy_v1, + .me = THIS_MODULE, + }, +#endif +}; + +static struct nf_logger ipt_log_logger __read_mostly = { + .name = "ipt_LOG", + .logfn = &ipt_log_packet_logger, + .me = THIS_MODULE, +}; + +#if IS_ENABLED(CONFIG_IPV6) +static struct nf_logger ip6t_log_logger __read_mostly = { + .name = "ip6t_LOG", + .logfn = &ip6t_log_packet_logger, + .me = THIS_MODULE, +}; +#endif + +static int __init log_tg_init(void) +{ + int ret; + + ret = xt_LOG_ring_init(); + if (ret < 0) + return ret; + + ret = xt_register_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); + if (ret < 0) + return ret; + + nf_log_register(NFPROTO_IPV4, &ipt_log_logger); +#if IS_ENABLED(CONFIG_IPV6) + nf_log_register(NFPROTO_IPV6, &ip6t_log_logger); +#endif + return 0; +} + +static void __exit log_tg_exit(void) +{ + nf_log_unregister(&ipt_log_logger); +#if IS_ENABLED(CONFIG_IPV6) + nf_log_unregister(&ip6t_log_logger); +#endif + xt_unregister_targets(log_tg_regs, ARRAY_SIZE(log_tg_regs)); + xt_LOG_ring_exit(); +} + +module_init(log_tg_init); +module_exit(log_tg_exit); diff --git a/net/netfilter/xt_LOG_ring.c b/net/netfilter/xt_LOG_ring.c new file mode 100644 index 0000000..cd1d871 --- /dev/null +++ b/net/netfilter/xt_LOG_ring.c @@ -0,0 +1,430 @@ +/* + * Copyright (c) 2012 Richard Weinberger + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define TARGETNAME_LEN 32 +#define ME "xt_LOG_ring" + +struct xt_LOG_ring_ctx { + char name[TARGETNAME_LEN]; + struct ring_buffer *buffer; + atomic_t pipe_in_use; + atomic_t refcnt; + + struct list_head list; +}; + +struct rlog_entry { + size_t count; + char msg[0]; +}; + +struct rlog_iter { + struct ring_buffer *buffer; + const char *buffer_name; + struct rlog_entry *ent; + + char print_buf[PAGE_SIZE]; + size_t print_buf_len; + size_t print_buf_pos; + + unsigned long lost_events; + int cpu; + + struct mutex lock; +}; + +static DEFINE_SPINLOCK(target_list_lock); +static LIST_HEAD(target_list); +static DECLARE_WAIT_QUEUE_HEAD(rlog_wait); +static struct proc_dir_entry *prlog; + +static void wakeup_work_handler(struct work_struct *work) +{ + wake_up(&rlog_wait); +} + +static DECLARE_WORK(wakeup_work, wakeup_work_handler); + +static void rlog_wake_up(void) +{ + schedule_work(&wakeup_work); +} + +int xt_LOG_ring_add_record(struct xt_LOG_ring_ctx *rctx, const char *buf, unsigned int len) +{ + struct rlog_entry *entry; + struct ring_buffer_event *event; + + event = ring_buffer_lock_reserve(rctx->buffer, sizeof(*entry) + len); + if (!event) + return 1; + + entry = ring_buffer_event_data(event); + memcpy(entry->msg, buf, len); + entry->count = len; + + ring_buffer_unlock_commit(rctx->buffer, event); + rlog_wake_up(); + + return 0; +} + +static struct rlog_entry *peek_next_entry(struct rlog_iter *iter, int cpu, + unsigned long long *ts) +{ + struct ring_buffer_event *event; + + event = ring_buffer_peek(iter->buffer, cpu, ts, &iter->lost_events); + + if (event) + return ring_buffer_event_data(event); + + return NULL; +} + +static struct rlog_entry *find_next_entry(struct rlog_iter *iter) +{ + struct rlog_entry *ent, *next = NULL; + unsigned long long next_ts = 0, ts; + int cpu, next_cpu = -1; + + for_each_buffer_cpu (iter->buffer, cpu) { + if (ring_buffer_empty_cpu(iter->buffer, cpu)) + continue; + + ent = peek_next_entry(iter, cpu, &ts); + + if (ent && (!next || ts < next_ts)) { + next = ent; + next_cpu = cpu; + next_ts = ts; + } + } + + iter->cpu = next_cpu; + + return next; +} + +static struct rlog_iter *find_next_entry_inc(struct rlog_iter *iter) +{ + iter->ent = find_next_entry(iter); + + if (iter->ent) + return iter; + + return NULL; +} + +static int buffer_empty(struct rlog_iter *iter) +{ + int cpu; + + for_each_buffer_cpu (iter->buffer, cpu) { + if (!ring_buffer_empty_cpu(iter->buffer, cpu)) + return 0; + } + + return 1; +} + +static ssize_t rlog_to_user(struct rlog_iter *iter, char __user *ubuf, + size_t cnt) +{ + int ret; + int len; + + if (!cnt) + goto out; + + len = iter->print_buf_len - iter->print_buf_pos; + if (len < 1) + return -EBUSY; + + if (cnt > len) + cnt = len; + + ret = copy_to_user(ubuf, iter->print_buf + iter->print_buf_pos, cnt); + if (ret == cnt) + return -EFAULT; + + cnt -= ret; + iter->print_buf_pos += cnt; + +out: + return cnt; +} + +static int rlog_open_pipe(struct inode *inode, struct file *file) +{ + struct rlog_iter *iter; + struct xt_LOG_ring_ctx *tgt = PDE(inode)->data; + int ret = 0; + + /* only one consuming reader is allowed */ + if (atomic_cmpxchg(&tgt->pipe_in_use, 0, 1)) { + ret = -EBUSY; + goto out; + } + + iter = kzalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) { + ret = -ENOMEM; + goto out; + } + + mutex_init(&iter->lock); + iter->buffer = tgt->buffer; + iter->buffer_name = tgt->name; + + file->private_data = iter; +out: + return ret; +} + +static unsigned int rlog_poll_pipe(struct file *file, poll_table *poll_table) +{ + struct rlog_iter *iter = file->private_data; + + if (!buffer_empty(iter)) + return POLLIN | POLLRDNORM; + + poll_wait(file, &rlog_wait, poll_table); + + if (!buffer_empty(iter)) + return POLLIN | POLLRDNORM; + + return 0; +} + +static int rlog_release_pipe(struct inode *inode, struct file *file) +{ + struct rlog_iter *iter = file->private_data; + struct xt_LOG_ring_ctx *tgt = PDE(inode)->data; + + mutex_destroy(&iter->lock); + kfree(iter); + atomic_set(&tgt->pipe_in_use, 0); + + return 0; +} + +static void wait_pipe(struct rlog_iter *iter) +{ + DEFINE_WAIT(wait); + + prepare_to_wait(&rlog_wait, &wait, TASK_INTERRUPTIBLE); + + if (buffer_empty(iter)) + schedule(); + + finish_wait(&rlog_wait, &wait); +} + +static int rlog_wait_pipe(struct file *file) +{ + struct rlog_iter *iter = file->private_data; + + while (buffer_empty(iter)) { + if (file->f_flags & O_NONBLOCK) + return -EAGAIN; + + mutex_unlock(&iter->lock); + + wait_pipe(iter); + + mutex_lock(&iter->lock); + + if (signal_pending(current)) + return -EINTR; + } + + return 1; +} + +static ssize_t rlog_read_pipe(struct file *file, char __user *ubuf, + size_t cnt, loff_t *ppos) +{ + struct rlog_iter *iter = file->private_data; + ssize_t ret; + + ret = rlog_to_user(iter, ubuf, cnt); + if (ret != -EBUSY) + goto out; + + iter->print_buf_pos = 0; + iter->print_buf_len = 0; + + if (cnt >= PAGE_SIZE) + cnt = PAGE_SIZE - 1; + + mutex_lock(&iter->lock); +again: + ret = rlog_wait_pipe(file); + if (ret <= 0) + goto out_unlock; + + while (find_next_entry_inc(iter) != NULL) { + struct rlog_entry *ent; + ent = iter->ent; + + if (ent->count >= PAGE_SIZE - iter->print_buf_len) + break; + + memcpy(iter->print_buf + iter->print_buf_len, ent->msg, + ent->count); + iter->print_buf_len += ent->count; + + ring_buffer_consume(iter->buffer, iter->cpu, NULL, + &iter->lost_events); + if (iter->lost_events) + printk(KERN_WARNING ME ": Ring %s " + "lost %lu events\n", iter->buffer_name, + iter->lost_events); + + if (iter->print_buf_len >= cnt) + break; + } + + ret = rlog_to_user(iter, ubuf, cnt); + + if (iter->print_buf_pos >= iter->print_buf_len) { + iter->print_buf_pos = 0; + iter->print_buf_len = 0; + } + + if (ret == -EBUSY) + goto again; +out_unlock: + mutex_unlock(&iter->lock); +out: + return ret; +} + +static const struct file_operations rlog_pipe_fops = { + .open = rlog_open_pipe, + .poll = rlog_poll_pipe, + .read = rlog_read_pipe, + .release = rlog_release_pipe, + .llseek = no_llseek, +}; + +struct xt_LOG_ring_ctx *xt_LOG_ring_new_ctx(const char *name, size_t rb_size) +{ + struct xt_LOG_ring_ctx *new; + + new = kmalloc(sizeof(*new), GFP_KERNEL); + if (!new) { + new = ERR_PTR(-ENOMEM); + + goto out; + } + + new->buffer = ring_buffer_alloc(rb_size << 10, RB_FL_OVERWRITE); + if (!new->buffer) { + kfree(new); + new = ERR_PTR(-ENOMEM); + + goto out; + } + + strlcpy(new->name, name, TARGETNAME_LEN); + + if (!proc_create_data(name, 0400, prlog, &rlog_pipe_fops, new)) { + ring_buffer_free(new->buffer); + kfree(new); + new = ERR_PTR(-ENOMEM); + + goto out; + } + + atomic_set(&new->pipe_in_use, 0); + atomic_set(&new->refcnt, 0); + + spin_lock(&target_list_lock); + list_add(&new->list, &target_list); + spin_unlock(&target_list_lock); +out: + return new; +} + +static void free_xt_LOG_ring_ctx(struct xt_LOG_ring_ctx *target) +{ + remove_proc_entry(target->name, prlog); + ring_buffer_free(target->buffer); + list_del(&target->list); + kfree(target); +} + +void xt_LOG_ring_get(struct xt_LOG_ring_ctx *ctx) +{ + atomic_inc(&ctx->refcnt); +} + +void xt_LOG_ring_put(struct xt_LOG_ring_ctx *ctx) +{ + if (atomic_dec_and_test(&ctx->refcnt)) + free_xt_LOG_ring_ctx(ctx); +} + +struct xt_LOG_ring_ctx *xt_LOG_ring_find_ctx(const char *name) +{ + struct list_head *e; + struct xt_LOG_ring_ctx *tmp, *victim = NULL; + + spin_lock(&target_list_lock); + + list_for_each(e, &target_list) { + tmp = list_entry(e, struct xt_LOG_ring_ctx, list); + if (strcmp(tmp->name, name) == 0) { + victim = tmp; + + goto out; + } + } + +out: + spin_unlock(&target_list_lock); + + return victim; +} + +void __exit xt_LOG_ring_exit(void) +{ + BUG_ON(!list_empty(&target_list)); + remove_proc_entry(ME, proc_net_netfilter); +} + +int __init xt_LOG_ring_init(void) +{ + prlog = proc_mkdir(ME, proc_net_netfilter); + if (!prlog) + return -ENOMEM; + + return 0; +} -- 1.7.7