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authorJozsef Kadlecsik <kadlec@blackhole.kfki.hu>2007-07-07 22:21:23 -0700
committerDavid S. Miller <davem@sunset.davemloft.net>2007-07-10 22:17:14 -0700
commitba9dda3ab5a865542e69dfe01edb2436857c9420 (patch)
tree93f92442a8ad134d78b4d7cd8dc74e089baef3d7 /net
parent1b50b8a371e90a5e110f466e4ac02cf6b5f681de (diff)
[NETFILTER]: x_tables: add TRACE target
The TRACE target can be used to follow IP and IPv6 packets through the ruleset. Signed-off-by: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu> Signed-off-by: Patrick NcHardy <kaber@trash.net> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/core/skbuff.c8
-rw-r--r--net/ipv4/ip_output.c4
-rw-r--r--net/ipv4/netfilter/ip_tables.c127
-rw-r--r--net/ipv6/ip6_output.c4
-rw-r--r--net/ipv6/netfilter/ip6_tables.c128
-rw-r--r--net/netfilter/Kconfig12
-rw-r--r--net/netfilter/Makefile1
-rw-r--r--net/netfilter/xt_TRACE.c53
8 files changed, 311 insertions, 26 deletions
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6a41b96b3d3..0583e8498f1 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -428,6 +428,10 @@ struct sk_buff *skb_clone(struct sk_buff *skb, gfp_t gfp_mask)
n->destructor = NULL;
C(mark);
__nf_copy(n, skb);
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+ C(nf_trace);
+#endif
#ifdef CONFIG_NET_SCHED
C(tc_index);
#ifdef CONFIG_NET_CLS_ACT
@@ -485,6 +489,10 @@ static void copy_skb_header(struct sk_buff *new, const struct sk_buff *old)
new->destructor = NULL;
new->mark = old->mark;
__nf_copy(new, old);
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+ new->nf_trace = old->nf_trace;
+#endif
#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
new->ipvs_property = old->ipvs_property;
#endif
diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index a7dd343d3a0..c9e2b5e6305 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -399,6 +399,10 @@ static void ip_copy_metadata(struct sk_buff *to, struct sk_buff *from)
to->tc_index = from->tc_index;
#endif
nf_copy(to, from);
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+ to->nf_trace = from->nf_trace;
+#endif
#if defined(CONFIG_IP_VS) || defined(CONFIG_IP_VS_MODULE)
to->ipvs_property = from->ipvs_property;
#endif
diff --git a/net/ipv4/netfilter/ip_tables.c b/net/ipv4/netfilter/ip_tables.c
index 7962306df58..650ab52e915 100644
--- a/net/ipv4/netfilter/ip_tables.c
+++ b/net/ipv4/netfilter/ip_tables.c
@@ -204,6 +204,112 @@ get_entry(void *base, unsigned int offset)
return (struct ipt_entry *)(base + offset);
}
+/* All zeroes == unconditional rule. */
+static inline int
+unconditional(const struct ipt_ip *ip)
+{
+ unsigned int i;
+
+ for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
+ if (((__u32 *)ip)[i])
+ return 0;
+
+ return 1;
+}
+
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+static const char *hooknames[] = {
+ [NF_IP_PRE_ROUTING] = "PREROUTING",
+ [NF_IP_LOCAL_IN] = "INPUT",
+ [NF_IP_FORWARD] = "FORWARD",
+ [NF_IP_LOCAL_OUT] = "OUTPUT",
+ [NF_IP_POST_ROUTING] = "POSTROUTING",
+};
+
+enum nf_ip_trace_comments {
+ NF_IP_TRACE_COMMENT_RULE,
+ NF_IP_TRACE_COMMENT_RETURN,
+ NF_IP_TRACE_COMMENT_POLICY,
+};
+
+static const char *comments[] = {
+ [NF_IP_TRACE_COMMENT_RULE] = "rule",
+ [NF_IP_TRACE_COMMENT_RETURN] = "return",
+ [NF_IP_TRACE_COMMENT_POLICY] = "policy",
+};
+
+static struct nf_loginfo trace_loginfo = {
+ .type = NF_LOG_TYPE_LOG,
+ .u = {
+ .log = {
+ .level = 4,
+ .logflags = NF_LOG_MASK,
+ },
+ },
+};
+
+static inline int
+get_chainname_rulenum(struct ipt_entry *s, struct ipt_entry *e,
+ char *hookname, char **chainname,
+ char **comment, unsigned int *rulenum)
+{
+ struct ipt_standard_target *t = (void *)ipt_get_target(s);
+
+ if (strcmp(t->target.u.kernel.target->name, IPT_ERROR_TARGET) == 0) {
+ /* Head of user chain: ERROR target with chainname */
+ *chainname = t->target.data;
+ (*rulenum) = 0;
+ } else if (s == e) {
+ (*rulenum)++;
+
+ if (s->target_offset == sizeof(struct ipt_entry)
+ && strcmp(t->target.u.kernel.target->name,
+ IPT_STANDARD_TARGET) == 0
+ && t->verdict < 0
+ && unconditional(&s->ip)) {
+ /* Tail of chains: STANDARD target (return/policy) */
+ *comment = *chainname == hookname
+ ? (char *)comments[NF_IP_TRACE_COMMENT_POLICY]
+ : (char *)comments[NF_IP_TRACE_COMMENT_RETURN];
+ }
+ return 1;
+ } else
+ (*rulenum)++;
+
+ return 0;
+}
+
+static void trace_packet(struct sk_buff *skb,
+ unsigned int hook,
+ const struct net_device *in,
+ const struct net_device *out,
+ char *tablename,
+ struct xt_table_info *private,
+ struct ipt_entry *e)
+{
+ void *table_base;
+ struct ipt_entry *root;
+ char *hookname, *chainname, *comment;
+ unsigned int rulenum = 0;
+
+ table_base = (void *)private->entries[smp_processor_id()];
+ root = get_entry(table_base, private->hook_entry[hook]);
+
+ hookname = chainname = (char *)hooknames[hook];
+ comment = (char *)comments[NF_IP_TRACE_COMMENT_RULE];
+
+ IPT_ENTRY_ITERATE(root,
+ private->size - private->hook_entry[hook],
+ get_chainname_rulenum,
+ e, hookname, &chainname, &comment, &rulenum);
+
+ nf_log_packet(AF_INET, hook, skb, in, out, &trace_loginfo,
+ "TRACE: %s:%s:%s:%u ",
+ tablename, chainname, comment, rulenum);
+}
+#endif
+
/* Returns one of the generic firewall policies, like NF_ACCEPT. */
unsigned int
ipt_do_table(struct sk_buff **pskb,
@@ -261,6 +367,14 @@ ipt_do_table(struct sk_buff **pskb,
t = ipt_get_target(e);
IP_NF_ASSERT(t->u.kernel.target);
+
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+ /* The packet is traced: log it */
+ if (unlikely((*pskb)->nf_trace))
+ trace_packet(*pskb, hook, in, out,
+ table->name, private, e);
+#endif
/* Standard target? */
if (!t->u.kernel.target->target) {
int v;
@@ -341,19 +455,6 @@ ipt_do_table(struct sk_buff **pskb,
#endif
}
-/* All zeroes == unconditional rule. */
-static inline int
-unconditional(const struct ipt_ip *ip)
-{
- unsigned int i;
-
- for (i = 0; i < sizeof(*ip)/sizeof(__u32); i++)
- if (((__u32 *)ip)[i])
- return 0;
-
- return 1;
-}
-
/* Figures out from what hook each rule can be called: returns 0 if
there are loops. Puts hook bitmask in comefrom. */
static int
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 31dafaf0b65..50d86e94d9e 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -521,6 +521,10 @@ static void ip6_copy_metadata(struct sk_buff *to, struct sk_buff *from)
to->tc_index = from->tc_index;
#endif
nf_copy(to, from);
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+ to->nf_trace = from->nf_trace;
+#endif
skb_copy_secmark(to, from);
}
diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c
index 7fe4d29708c..4f93b79163a 100644
--- a/net/ipv6/netfilter/ip6_tables.c
+++ b/net/ipv6/netfilter/ip6_tables.c
@@ -241,6 +241,113 @@ get_entry(void *base, unsigned int offset)
return (struct ip6t_entry *)(base + offset);
}
+/* All zeroes == unconditional rule. */
+static inline int
+unconditional(const struct ip6t_ip6 *ipv6)
+{
+ unsigned int i;
+
+ for (i = 0; i < sizeof(*ipv6); i++)
+ if (((char *)ipv6)[i])
+ break;
+
+ return (i == sizeof(*ipv6));
+}
+
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+/* This cries for unification! */
+static const char *hooknames[] = {
+ [NF_IP6_PRE_ROUTING] = "PREROUTING",
+ [NF_IP6_LOCAL_IN] = "INPUT",
+ [NF_IP6_FORWARD] = "FORWARD",
+ [NF_IP6_LOCAL_OUT] = "OUTPUT",
+ [NF_IP6_POST_ROUTING] = "POSTROUTING",
+};
+
+enum nf_ip_trace_comments {
+ NF_IP6_TRACE_COMMENT_RULE,
+ NF_IP6_TRACE_COMMENT_RETURN,
+ NF_IP6_TRACE_COMMENT_POLICY,
+};
+
+static const char *comments[] = {
+ [NF_IP6_TRACE_COMMENT_RULE] = "rule",
+ [NF_IP6_TRACE_COMMENT_RETURN] = "return",
+ [NF_IP6_TRACE_COMMENT_POLICY] = "policy",
+};
+
+static struct nf_loginfo trace_loginfo = {
+ .type = NF_LOG_TYPE_LOG,
+ .u = {
+ .log = {
+ .level = 4,
+ .logflags = NF_LOG_MASK,
+ },
+ },
+};
+
+static inline int
+get_chainname_rulenum(struct ip6t_entry *s, struct ip6t_entry *e,
+ char *hookname, char **chainname,
+ char **comment, unsigned int *rulenum)
+{
+ struct ip6t_standard_target *t = (void *)ip6t_get_target(s);
+
+ if (strcmp(t->target.u.kernel.target->name, IP6T_ERROR_TARGET) == 0) {
+ /* Head of user chain: ERROR target with chainname */
+ *chainname = t->target.data;
+ (*rulenum) = 0;
+ } else if (s == e) {
+ (*rulenum)++;
+
+ if (s->target_offset == sizeof(struct ip6t_entry)
+ && strcmp(t->target.u.kernel.target->name,
+ IP6T_STANDARD_TARGET) == 0
+ && t->verdict < 0
+ && unconditional(&s->ipv6)) {
+ /* Tail of chains: STANDARD target (return/policy) */
+ *comment = *chainname == hookname
+ ? (char *)comments[NF_IP6_TRACE_COMMENT_POLICY]
+ : (char *)comments[NF_IP6_TRACE_COMMENT_RETURN];
+ }
+ return 1;
+ } else
+ (*rulenum)++;
+
+ return 0;
+}
+
+static void trace_packet(struct sk_buff *skb,
+ unsigned int hook,
+ const struct net_device *in,
+ const struct net_device *out,
+ char *tablename,
+ struct xt_table_info *private,
+ struct ip6t_entry *e)
+{
+ void *table_base;
+ struct ip6t_entry *root;
+ char *hookname, *chainname, *comment;
+ unsigned int rulenum = 0;
+
+ table_base = (void *)private->entries[smp_processor_id()];
+ root = get_entry(table_base, private->hook_entry[hook]);
+
+ hookname = chainname = (char *)hooknames[hook];
+ comment = (char *)comments[NF_IP6_TRACE_COMMENT_RULE];
+
+ IP6T_ENTRY_ITERATE(root,
+ private->size - private->hook_entry[hook],
+ get_chainname_rulenum,
+ e, hookname, &chainname, &comment, &rulenum);
+
+ nf_log_packet(AF_INET6, hook, skb, in, out, &trace_loginfo,
+ "TRACE: %s:%s:%s:%u ",
+ tablename, chainname, comment, rulenum);
+}
+#endif
+
/* Returns one of the generic firewall policies, like NF_ACCEPT. */
unsigned int
ip6t_do_table(struct sk_buff **pskb,
@@ -298,6 +405,14 @@ ip6t_do_table(struct sk_buff **pskb,
t = ip6t_get_target(e);
IP_NF_ASSERT(t->u.kernel.target);
+
+#if defined(CONFIG_NETFILTER_XT_TARGET_TRACE) || \
+ defined(CONFIG_NETFILTER_XT_TARGET_TRACE_MODULE)
+ /* The packet is traced: log it */
+ if (unlikely((*pskb)->nf_trace))
+ trace_packet(*pskb, hook, in, out,
+ table->name, private, e);
+#endif
/* Standard target? */
if (!t->u.kernel.target->target) {
int v;
@@ -377,19 +492,6 @@ ip6t_do_table(struct sk_buff **pskb,
#endif
}
-/* All zeroes == unconditional rule. */
-static inline int
-unconditional(const struct ip6t_ip6 *ipv6)
-{
- unsigned int i;
-
- for (i = 0; i < sizeof(*ipv6); i++)
- if (((char *)ipv6)[i])
- break;
-
- return (i == sizeof(*ipv6));
-}
-
/* Figures out from what hook each rule can be called: returns 0 if
there are loops. Puts hook bitmask in comefrom. */
static int
diff --git a/net/netfilter/Kconfig b/net/netfilter/Kconfig
index aa567faa2a8..df5e8dab871 100644
--- a/net/netfilter/Kconfig
+++ b/net/netfilter/Kconfig
@@ -343,6 +343,18 @@ config NETFILTER_XT_TARGET_NOTRACK
If you want to compile it as a module, say M here and read
<file:Documentation/kbuild/modules.txt>. If unsure, say `N'.
+config NETFILTER_XT_TARGET_TRACE
+ tristate '"TRACE" target support'
+ depends on NETFILTER_XTABLES
+ depends on IP_NF_RAW || IP6_NF_RAW
+ help
+ The TRACE target allows you to mark packets so that the kernel
+ will log every rule which match the packets as those traverse
+ the tables, chains, rules.
+
+ If you want to compile it as a module, say M here and read
+ <file:Documentation/modules.txt>. If unsure, say `N'.
+
config NETFILTER_XT_TARGET_SECMARK
tristate '"SECMARK" target support'
depends on NETFILTER_XTABLES && NETWORK_SECMARK
diff --git a/net/netfilter/Makefile b/net/netfilter/Makefile
index 3cf5b9cd6fe..3b792687f00 100644
--- a/net/netfilter/Makefile
+++ b/net/netfilter/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_NETFILTER_XT_TARGET_MARK) += xt_MARK.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NFQUEUE) += xt_NFQUEUE.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NFLOG) += xt_NFLOG.o
obj-$(CONFIG_NETFILTER_XT_TARGET_NOTRACK) += xt_NOTRACK.o
+obj-$(CONFIG_NETFILTER_XT_TARGET_TRACE) += xt_TRACE.o
obj-$(CONFIG_NETFILTER_XT_TARGET_SECMARK) += xt_SECMARK.o
obj-$(CONFIG_NETFILTER_XT_TARGET_TCPMSS) += xt_TCPMSS.o
obj-$(CONFIG_NETFILTER_XT_TARGET_CONNSECMARK) += xt_CONNSECMARK.o
diff --git a/net/netfilter/xt_TRACE.c b/net/netfilter/xt_TRACE.c
new file mode 100644
index 00000000000..b82fc468034
--- /dev/null
+++ b/net/netfilter/xt_TRACE.c
@@ -0,0 +1,53 @@
+/* This is a module which is used to mark packets for tracing.
+ */
+#include <linux/module.h>
+#include <linux/skbuff.h>
+
+#include <linux/netfilter/x_tables.h>
+
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("ipt_TRACE");
+MODULE_ALIAS("ip6t_TRACE");
+
+static unsigned int
+target(struct sk_buff **pskb,
+ const struct net_device *in,
+ const struct net_device *out,
+ unsigned int hooknum,
+ const struct xt_target *target,
+ const void *targinfo)
+{
+ (*pskb)->nf_trace = 1;
+ return XT_CONTINUE;
+}
+
+static struct xt_target xt_trace_target[] = {
+ {
+ .name = "TRACE",
+ .family = AF_INET,
+ .target = target,
+ .table = "raw",
+ .me = THIS_MODULE,
+ },
+ {
+ .name = "TRACE",
+ .family = AF_INET6,
+ .target = target,
+ .table = "raw",
+ .me = THIS_MODULE,
+ },
+};
+
+static int __init xt_trace_init(void)
+{
+ return xt_register_targets(xt_trace_target,
+ ARRAY_SIZE(xt_trace_target));
+}
+
+static void __exit xt_trace_fini(void)
+{
+ xt_unregister_targets(xt_trace_target, ARRAY_SIZE(xt_trace_target));
+}
+
+module_init(xt_trace_init);
+module_exit(xt_trace_fini);