conntrack: add timestamp support

This patch adds the connection tracking extension that allows
conntrack timestamping.

This requires a Linux kernel >= 2.6.38.

We have now 65 attributes, we need 96 bits to store what attributes
are set in the objects.

Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

7 files changed, 249 insertions, 25 deletions

diff --git a/src/conntrack/api.c b/src/conntrack/api.c
index 6b73817..2262974 100644
--- a/src/conntrack/api.c
+++ b/src/conntrack/api.c
@@ -356,6 +356,7 @@ void nfct_callback_unregister2(struct nfct_handle *h)
  * 	- ATTR_ID
  * 	- ATTR_*_COUNTER_*
  *	- ATTR_SECCTX
+ *	- ATTR_TIMESTAMP_*
  * The call of this function for such attributes do nothing.
  */
 void nfct_set_attr(struct nf_conntrack *ct,
@@ -970,7 +971,20 @@ int nfct_catch(struct nfct_handle *h)
  * The output flags are:
  * 	- NFCT_OF_SHOW_LAYER3: include layer 3 information in the output, 
  * 	this is *only* required by NFCT_O_DEFAULT.
- * 	- NFCT_OF_TIME: display time.
+ * 	- NFCT_OF_TIME: display current time.
+ * 	- NFCT_OF_ID: display the ID number.
+ * 	- NFCT_OF_TIMESTAMP: display creation and (if exists) deletion time.
+ *
+ * To use NFCT_OF_TIMESTAMP, you have to:
+ * \verbatim
+ *  $ echo 1 > /proc/sys/net/netfilter/nf_conntrack_timestamp
+\endverbatim
+ * This requires a Linux kernel >= 2.6.38.
+ *
+ * Note that NFCT_OF_TIME displays the current time when nfct_snprintf() has
+ * been called. Thus, it can be used to know when a flow was destroy if you
+ * print the message just after you receive the destroy event. If you want
+ * more accurate timestamping, use NFCT_OF_TIMESTAMP.
  *
  * This function returns the size of the information that _would_ have been 
  * written to the buffer, even if there was no room for it. Thus, the
diff --git a/src/conntrack/copy.c b/src/conntrack/copy.c
index 9148640..591dde1 100644
--- a/src/conntrack/copy.c
+++ b/src/conntrack/copy.c
@@ -423,6 +423,18 @@ static void copy_attr_secctx(struct nf_conntrack *dest,
 	dest->secctx = strdup(orig->secctx);
 }
 
+static void copy_attr_timestamp_start(struct nf_conntrack *dest,
+				      const struct nf_conntrack *orig)
+{
+	dest->timestamp.start = orig->timestamp.start;
+}
+
+static void copy_attr_timestamp_stop(struct nf_conntrack *dest,
+				     const struct nf_conntrack *orig)
+{
+	dest->timestamp.stop = orig->timestamp.stop;
+}
+
 const copy_attr copy_attr_array[ATTR_MAX] = {
 	[ATTR_ORIG_IPV4_SRC]		= copy_attr_orig_ipv4_src,
 	[ATTR_ORIG_IPV4_DST] 		= copy_attr_orig_ipv4_dst,
@@ -487,4 +499,6 @@ const copy_attr copy_attr_array[ATTR_MAX] = {
 	[ATTR_TCP_WSCALE_REPL]		= copy_attr_tcp_wscale_repl,
 	[ATTR_ZONE]			= copy_attr_zone,
 	[ATTR_SECCTX]			= copy_attr_secctx,
+	[ATTR_TIMESTAMP_START]		= copy_attr_timestamp_start,
+	[ATTR_TIMESTAMP_STOP]		= copy_attr_timestamp_stop,
 };
diff --git a/src/conntrack/getter.c b/src/conntrack/getter.c
index 8a093c6..0b56468 100644
--- a/src/conntrack/getter.c
+++ b/src/conntrack/getter.c
@@ -322,6 +322,16 @@ static const void *get_attr_secctx(const struct nf_conntrack *ct)
 	return ct->secctx;
 }
 
+static const void *get_attr_timestamp_start(const struct nf_conntrack *ct)
+{
+	return &ct->timestamp.start;
+}
+
+static const void *get_attr_timestamp_stop(const struct nf_conntrack *ct)
+{
+	return &ct->timestamp.stop;
+}
+
 const get_attr get_attr_array[ATTR_MAX] = {
 	[ATTR_ORIG_IPV4_SRC]		= get_attr_orig_ipv4_src,
 	[ATTR_ORIG_IPV4_DST] 		= get_attr_orig_ipv4_dst,
@@ -386,4 +396,6 @@ const get_attr get_attr_array[ATTR_MAX] = {
 	[ATTR_TCP_WSCALE_REPL]		= get_attr_tcp_wscale_repl,
 	[ATTR_ZONE]			= get_attr_zone,
 	[ATTR_SECCTX]			= get_attr_secctx,
+	[ATTR_TIMESTAMP_START]		= get_attr_timestamp_start,
+	[ATTR_TIMESTAMP_STOP]		= get_attr_timestamp_stop,
 };
diff --git a/src/conntrack/parse.c b/src/conntrack/parse.c
index 841693e..743e8d4 100644
--- a/src/conntrack/parse.c
+++ b/src/conntrack/parse.c
@@ -453,6 +453,26 @@ int __parse_message_type(const struct nlmsghdr *nlh)
 	return ret;
 }
 
+static void
+__parse_timestamp(const struct nfattr *attr, struct nf_conntrack *ct)
+{
+	struct nfattr *tb[CTA_TIMESTAMP_MAX];
+
+	nfnl_parse_nested(tb, CTA_TIMESTAMP_MAX, attr);
+	if (tb[CTA_TIMESTAMP_START-1]) {
+		u_int64_t tmp;
+		memcpy(&tmp, NFA_DATA(tb[CTA_TIMESTAMP_START-1]), sizeof(tmp));
+		ct->timestamp.start = __be64_to_cpu(tmp);
+		set_bit(ATTR_TIMESTAMP_START, ct->set);
+	}
+	if (tb[CTA_TIMESTAMP_STOP-1]) {
+		u_int64_t tmp;
+		memcpy(&tmp, NFA_DATA(tb[CTA_TIMESTAMP_STOP-1]), sizeof(tmp));
+		ct->timestamp.stop = __be64_to_cpu(tmp);
+		set_bit(ATTR_TIMESTAMP_STOP, ct->set);
+	}
+}
+
 void __parse_conntrack(const struct nlmsghdr *nlh,
 		       struct nfattr *cda[],
 		       struct nf_conntrack *ct)
@@ -538,4 +558,7 @@ void __parse_conntrack(const struct nlmsghdr *nlh,
 
 	if (cda[CTA_SECCTX-1])
 		__parse_secctx(cda[CTA_SECCTX-1], ct);
+
+	if (cda[CTA_TIMESTAMP-1])
+		__parse_timestamp(cda[CTA_TIMESTAMP-1], ct);
 }
diff --git a/src/conntrack/setter.c b/src/conntrack/setter.c
index 99ac8d7..3282035 100644
--- a/src/conntrack/setter.c
+++ b/src/conntrack/setter.c
@@ -411,4 +411,6 @@ const set_attr set_attr_array[ATTR_MAX] = {
 	[ATTR_TCP_WSCALE_REPL]	= set_attr_tcp_wscale_repl,
 	[ATTR_ZONE]		= set_attr_zone,
 	[ATTR_SECCTX]		= set_attr_do_nothing,
+	[ATTR_TIMESTAMP_START]	= set_attr_do_nothing,
+	[ATTR_TIMESTAMP_STOP]	= set_attr_do_nothing,
 };
diff --git a/src/conntrack/snprintf_default.c b/src/conntrack/snprintf_default.c
index abb9d9f..8523bd1 100644
--- a/src/conntrack/snprintf_default.c
+++ b/src/conntrack/snprintf_default.c
@@ -231,6 +231,47 @@ __snprintf_secctx(char *buf, unsigned int len, const struct nf_conntrack *ct)
 	return (snprintf(buf, len, "secctx=%s ", ct->secctx));
 }
 
+static int
+__snprintf_timestamp_start(char *buf, unsigned int len,
+			   const struct nf_conntrack *ct)
+{
+	time_t start = (time_t)(ct->timestamp.start / NSEC_PER_SEC);
+	char *tmp = ctime(&start);
+
+	/* overwrite \n in the ctime() output. */
+	tmp[strlen(tmp)-1] = '\0';
+	return (snprintf(buf, len, "[start=%s] ", tmp));
+}
+
+static int
+__snprintf_timestamp_stop(char *buf, unsigned int len,
+			  const struct nf_conntrack *ct)
+{
+	time_t stop = (time_t)(ct->timestamp.stop / NSEC_PER_SEC);
+	char *tmp = ctime(&stop);
+
+	/* overwrite \n in the ctime() output. */
+	tmp[strlen(tmp)-1] = '\0';
+	return (snprintf(buf, len, "[stop=%s] ", tmp));
+}
+
+static int
+__snprintf_timestamp_delta(char *buf, unsigned int len,
+			   const struct nf_conntrack *ct)
+{
+	time_t delta_time, stop;
+
+	if (ct->timestamp.stop == 0)
+		time(&stop);
+	else
+		stop = (time_t)(ct->timestamp.stop / NSEC_PER_SEC);
+
+	delta_time = stop - (time_t)(ct->timestamp.start / NSEC_PER_SEC);
+
+	return (snprintf(buf, len, "delta-time=%llu ",
+			(unsigned long long)delta_time));
+}
+
 int __snprintf_conntrack_default(char *buf, 
 				 unsigned int len,
 				 const struct nf_conntrack *ct,
@@ -337,6 +378,21 @@ int __snprintf_conntrack_default(char *buf,
 		BUFFER_SIZE(ret, size, len, offset);
 	}
 
+	if (test_bit(ATTR_TIMESTAMP_START, ct->set)) {
+		ret = __snprintf_timestamp_delta(buf+offset, len, ct);
+		BUFFER_SIZE(ret, size, len, offset);
+	}
+	if (flags & NFCT_OF_TIMESTAMP) {
+		if (test_bit(ATTR_TIMESTAMP_START, ct->set)) {
+			ret = __snprintf_timestamp_start(buf+offset, len, ct);
+			BUFFER_SIZE(ret, size, len, offset);
+		}
+		if (test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
+			ret = __snprintf_timestamp_stop(buf+offset, len, ct);
+			BUFFER_SIZE(ret, size, len, offset);
+		}
+	}
+
 	if (test_bit(ATTR_USE, ct->set)) {
 		ret = __snprintf_use(buf+offset, len, ct);
 		BUFFER_SIZE(ret, size, len, offset);
diff --git a/src/conntrack/snprintf_xml.c b/src/conntrack/snprintf_xml.c
index 97f6650..12dd686 100644
--- a/src/conntrack/snprintf_xml.c
+++ b/src/conntrack/snprintf_xml.c
@@ -198,6 +198,97 @@ static int __snprintf_counters_xml(char *buf,
 	return size;
 }
 
+static int
+__snprintf_timestamp_start(char *buf, unsigned int len,
+			   const struct nf_conntrack *ct)
+{
+	int ret;
+	unsigned int size = 0, offset = 0;
+
+	ret = snprintf(buf, len, "<start>%llu</start>",
+		       (unsigned long long)ct->timestamp.start);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	return size;
+}
+
+static int
+__snprintf_timestamp_stop(char *buf, unsigned int len,
+			  const struct nf_conntrack *ct)
+{
+	int ret;
+	unsigned int size = 0, offset = 0;
+
+	ret = snprintf(buf, len, "<stop>%llu</stop>",
+		       (unsigned long long)ct->timestamp.stop);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	return size;
+}
+
+static int
+__snprintf_deltatime_now(char *buf, unsigned int len,
+			 const struct nf_conntrack *ct)
+{
+	int ret;
+	unsigned int size = 0, offset = 0;
+	time_t now, delta_time;
+
+	time(&now);
+        delta_time = now - (time_t)(ct->timestamp.start / NSEC_PER_SEC);
+
+	ret = snprintf(buf+offset, len, "<deltatime>%llu</deltatime>",
+		(unsigned long long)delta_time);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	return size;
+}
+
+static int
+__snprintf_deltatime(char *buf, unsigned int len, const struct nf_conntrack *ct)
+{
+	int ret;
+	unsigned int size = 0, offset = 0;
+	time_t delta_time = (time_t)((ct->timestamp.stop -
+				ct->timestamp.start) / NSEC_PER_SEC);
+
+	ret = snprintf(buf+offset, len, "<deltatime>%llu</deltatime>",
+		(unsigned long long)delta_time);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	return size;
+}
+
+static int
+__snprintf_localtime_xml(char *buf, unsigned int len, const struct tm *tm)
+{
+	int ret = 0;
+	unsigned int size = 0, offset = 0;
+
+	ret = snprintf(buf+offset, len, "<hour>%d</hour>", tm->tm_hour);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<min>%02d</min>", tm->tm_min);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<sec>%02d</sec>", tm->tm_sec);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<wday>%d</wday>", tm->tm_wday + 1);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<day>%d</day>", tm->tm_mday);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<month>%d</month>", tm->tm_mon + 1);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	ret = snprintf(buf+offset, len, "<year>%d</year>", 1900 + tm->tm_year);
+	BUFFER_SIZE(ret, size, len, offset);
+
+	return size;
+}
+
 static int __snprintf_tuple_xml(char *buf,
 				unsigned int len,
 				const struct nf_conntrack *ct,
@@ -298,7 +389,9 @@ int __snprintf_conntrack_xml(char *buf,
 	    test_bit(ATTR_ZONE, ct->set) ||
 	    test_bit(ATTR_USE, ct->set) ||
 	    test_bit(ATTR_STATUS, ct->set) ||
-	    test_bit(ATTR_ID, ct->set)) {
+	    test_bit(ATTR_ID, ct->set) ||
+	    test_bit(ATTR_TIMESTAMP_START, ct->set) ||
+	    test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
 		ret = snprintf(buf+offset, len, 
 			       "<meta direction=\"independent\">");
 		BUFFER_SIZE(ret, size, len, offset);
@@ -378,6 +471,35 @@ int __snprintf_conntrack_xml(char *buf,
 		BUFFER_SIZE(ret, size, len, offset);
 	}
 
+	if (flags & NFCT_OF_TIMESTAMP) {
+		if (test_bit(ATTR_TIMESTAMP_START, ct->set) ||
+		    test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
+			ret = snprintf(buf+offset, len, "<timestamp>");
+			BUFFER_SIZE(ret, size, len, offset);
+		}
+		if (test_bit(ATTR_TIMESTAMP_START, ct->set)) {
+	 		ret = __snprintf_timestamp_start(buf+offset, len, ct);
+			BUFFER_SIZE(ret, size, len, offset);
+		}
+		if (test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
+	 		ret = __snprintf_timestamp_stop(buf+offset, len, ct);
+			BUFFER_SIZE(ret, size, len, offset);
+		}
+		if (test_bit(ATTR_TIMESTAMP_START, ct->set) ||
+		    test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
+			ret = snprintf(buf+offset, len, "</timestamp>");
+			BUFFER_SIZE(ret, size, len, offset);
+		}
+	}
+	if (test_bit(ATTR_TIMESTAMP_START, ct->set) &&
+	    test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
+		ret = __snprintf_deltatime(buf+offset, len, ct);
+		BUFFER_SIZE(ret, size, len, offset);
+	} else if (test_bit(ATTR_TIMESTAMP_START, ct->set)) {
+		ret = __snprintf_deltatime_now(buf+offset, len, ct);
+		BUFFER_SIZE(ret, size, len, offset);
+	}
+
 	if (test_bit(ATTR_TCP_STATE, ct->set) ||
 	    test_bit(ATTR_SCTP_STATE, ct->set) ||
 	    test_bit(ATTR_DCCP_STATE, ct->set) ||
@@ -387,7 +509,9 @@ int __snprintf_conntrack_xml(char *buf,
 	    test_bit(ATTR_ZONE, ct->set) ||
 	    test_bit(ATTR_USE, ct->set) ||
 	    test_bit(ATTR_STATUS, ct->set) ||
-	    test_bit(ATTR_ID, ct->set)) {
+	    test_bit(ATTR_ID, ct->set) ||
+	    test_bit(ATTR_TIMESTAMP_START, ct->set) ||
+	    test_bit(ATTR_TIMESTAMP_STOP, ct->set)) {
 	    	ret = snprintf(buf+offset, len, "</meta>");
 		BUFFER_SIZE(ret, size, len, offset);
 	}
@@ -403,28 +527,7 @@ int __snprintf_conntrack_xml(char *buf,
 		ret = snprintf(buf+offset, len, "<when>");
 		BUFFER_SIZE(ret, size, len, offset);
 
-		ret = snprintf(buf+offset, len, "<hour>%d</hour>", tm.tm_hour);
-		BUFFER_SIZE(ret, size, len, offset);
-
-		ret = snprintf(buf+offset, len, "<min>%02d</min>", tm.tm_min);
-		BUFFER_SIZE(ret, size, len, offset);
-
-		ret = snprintf(buf+offset, len, "<sec>%02d</sec>", tm.tm_sec);
-		BUFFER_SIZE(ret, size, len, offset);
-
-		ret = snprintf(buf+offset, len, "<wday>%d</wday>", 
-			       tm.tm_wday + 1);
-		BUFFER_SIZE(ret, size, len, offset);
-
-		ret = snprintf(buf+offset, len, "<day>%d</day>", tm.tm_mday);
-		BUFFER_SIZE(ret, size, len, offset);
-
-		ret = snprintf(buf+offset, len, "<month>%d</month>", 
-			       tm.tm_mon + 1);
-		BUFFER_SIZE(ret, size, len, offset);
-
-		ret = snprintf(buf+offset, len, "<year>%d</year>", 
-			       1900 + tm.tm_year);
+		ret = __snprintf_localtime_xml(buf+offset, len, &tm);
 		BUFFER_SIZE(ret, size, len, offset);
 
 		ret = snprintf(buf+offset, len, "</when>");