dhcpv6: implement statistics for DHCPv6

Problem:
    odhcp6c does not provide any statistics.

Solution:
    Count the number of packets transmitted or received by message type.
    Add a UBus RPC method to get this information.

Signed-off-by: Nicolas BESNARD <nico.besnard31@gmail.com>
Signed-off-by: Paul Donald <newtwen+github@gmail.com>
Link: https://github.com/openwrt/odhcp6c/pull/106
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

3 files changed, 129 insertions, 1 deletions

diff --git a/src/dhcpv6.c b/src/dhcpv6.c
index 9637ada..dc48fe0 100644
--- a/src/dhcpv6.c
+++ b/src/dhcpv6.c
@@ -118,6 +118,9 @@ static uint8_t reconf_key[16];
 // client options
 static unsigned int client_options = 0;
 
+// counters for statistics
+static struct dhcpv6_stats dhcpv6_stats = {0};
+
 static uint32_t ntohl_unaligned(const uint8_t *data)
 {
 	uint32_t buf;
@@ -138,6 +141,54 @@ static void dhcpv6_prev_state(void)
 	dhcpv6_reset_state_timeout();
 }
 
+static void dhcpv6_inc_counter(enum dhcpv6_msg type)
+{
+	switch (type) {
+	case DHCPV6_MSG_SOLICIT:
+		dhcpv6_stats.solicit++;
+		break;
+
+	case DHCPV6_MSG_ADVERT:
+		dhcpv6_stats.advertise++;
+		break;
+
+	case DHCPV6_MSG_REQUEST:
+		dhcpv6_stats.request++;
+		break;
+
+	case DHCPV6_MSG_RENEW:
+		dhcpv6_stats.renew++;
+		break;
+
+	case DHCPV6_MSG_REBIND:
+		dhcpv6_stats.rebind++;
+		break;
+
+	case DHCPV6_MSG_REPLY:
+		dhcpv6_stats.reply++;
+		break;
+
+	case DHCPV6_MSG_RELEASE:
+		dhcpv6_stats.release++;
+		break;
+
+	case DHCPV6_MSG_DECLINE:
+		dhcpv6_stats.decline++;
+		break;
+
+	case DHCPV6_MSG_RECONF:
+		dhcpv6_stats.reconfigure++;
+		break;
+
+	case DHCPV6_MSG_INFO_REQ:
+		dhcpv6_stats.information_request++;
+		break;
+
+	default:
+		break;
+	}
+}
+
 static char *dhcpv6_msg_to_str(enum dhcpv6_msg msg)
 {
 	switch (msg) {
@@ -340,6 +391,16 @@ void dhcpv6_reset_state_timeout(void)
 	dhcpv6_state_timeout = 0;
 }
 
+struct dhcpv6_stats dhcpv6_get_stats(void)
+{
+	return dhcpv6_stats;
+}
+
+void dhcpv6_reset_stats(void)
+{
+	memset(&dhcpv6_stats, 0, sizeof(dhcpv6_stats));
+}
+
 int init_dhcpv6(const char *ifname, unsigned int options, int sk_prio, int sol_timeout, unsigned int dscp)
 {
 	client_options = options;
@@ -794,6 +855,9 @@ static void dhcpv6_send(enum dhcpv6_msg type, uint8_t trid[3], uint32_t ecs)
 			dhcpv6_msg_to_str(type),
 			inet_ntop(AF_INET6, (const void *)&srv.sin6_addr,
 				in6_str, sizeof(in6_str)), strerror(errno));
+		dhcpv6_stats.transmit_failures++;
+	} else {
+		dhcpv6_inc_counter(type);
 	}
 }
 
@@ -1900,14 +1964,18 @@ int dhcpv6_receive_response(enum dhcpv6_msg type)
 	}
 
 	if (pktinfo == NULL) {
+		dhcpv6_stats.discarded_packets++;
 		return -1;
 	}
 
 	if (!dhcpv6_response_is_valid(buf, len, retx->tr_id, type,
 					 &pktinfo->ipi6_addr)) {
+		dhcpv6_stats.discarded_packets++;
 		return -1;
 	}
 
+	dhcpv6_inc_counter(hdr->msg_type);
+
 	uint8_t *opt = &buf[4];
 	uint8_t *opt_end = opt + len - 4;
 	retx->round_start = odhcp6c_get_milli_time();
diff --git a/src/odhcp6c.h b/src/odhcp6c.h
index a28decc..740dce7 100644
--- a/src/odhcp6c.h
+++ b/src/odhcp6c.h
@@ -323,7 +323,22 @@ struct dhcpv6_server_cand {
 	size_t ia_pd_len;
 };
 
-
+struct dhcpv6_stats {
+	uint64_t solicit;
+	uint64_t advertise;
+	uint64_t request;
+	uint64_t confirm;
+	uint64_t renew;
+	uint64_t rebind;
+	uint64_t reply;
+	uint64_t release;
+	uint64_t decline;
+	uint64_t reconfigure;
+	uint64_t information_request;
+	uint64_t discarded_packets;
+	uint64_t transmit_failures;
+};
+	
 enum odhcp6c_state {
 	STATE_CLIENT_ID,
 	STATE_SERVER_ID,
@@ -437,6 +452,8 @@ int dhcpv6_receive_response(enum dhcpv6_msg type);
 enum dhcpv6_state dhcpv6_get_state(void);
 void dhcpv6_set_state(enum dhcpv6_state state);
 int dhcpv6_get_socket(void);
+struct dhcpv6_stats dhcpv6_get_stats(void);
+void dhcpv6_reset_stats(void);
 int dhcpv6_state_processing(enum dhcpv6_msg type);
 int dhcpv6_get_state_timeout(void);
 void dhcpv6_set_state_timeout(int timeout);
diff --git a/src/ubus.c b/src/ubus.c
index ebe16ae..402ba68 100644
--- a/src/ubus.c
+++ b/src/ubus.c
@@ -103,9 +103,15 @@ static char ubus_name[24];
 
 static int ubus_handle_get_state(struct ubus_context *ctx, struct ubus_object *obj,
 		struct ubus_request_data *req, const char *method, struct blob_attr *msg);
+static int ubus_handle_get_stats(struct ubus_context *ctx, struct ubus_object *obj,
+		struct ubus_request_data *req, const char *method, struct blob_attr *msg);
+static int ubus_handle_reset_stats(struct ubus_context *ctx, struct ubus_object *obj,
+		struct ubus_request_data *req, const char *method, struct blob_attr *msg);
 
 static struct ubus_method odhcp6c_object_methods[] = {
 	UBUS_METHOD_NOARG("get_state", ubus_handle_get_state),
+	UBUS_METHOD_NOARG("get_statistics", ubus_handle_get_stats),
+	UBUS_METHOD_NOARG("reset_statistics", ubus_handle_reset_stats),
 };
 
 static struct ubus_object_type odhcp6c_object_type = 
@@ -528,6 +534,43 @@ static int states_to_blob(void)
 	return UBUS_STATUS_OK;
 }
 
+static int ubus_handle_get_stats(struct ubus_context *ctx, _unused struct ubus_object *obj,
+		struct ubus_request_data *req, _unused const char *method,
+		_unused struct blob_attr *msg)
+{
+	struct dhcpv6_stats stats = dhcpv6_get_stats();
+
+	blob_buf_init(&b, BLOBMSG_TYPE_TABLE);
+	blobmsg_add_u64(&b, "dhcp_solicit", stats.solicit);
+	blobmsg_add_u64(&b, "dhcp_advertise", stats.advertise);
+	blobmsg_add_u64(&b, "dhcp_request", stats.request);
+	blobmsg_add_u64(&b, "dhcp_confirm", stats.confirm);
+	blobmsg_add_u64(&b, "dhcp_renew", stats.renew);
+	blobmsg_add_u64(&b, "dhcp_rebind", stats.rebind);
+	blobmsg_add_u64(&b, "dhcp_reply", stats.reply);
+	blobmsg_add_u64(&b, "dhcp_release", stats.release);
+	blobmsg_add_u64(&b, "dhcp_decline", stats.decline);
+	blobmsg_add_u64(&b, "dhcp_reconfigure", stats.reconfigure);
+	blobmsg_add_u64(&b, "dhcp_information_request", stats.information_request);
+	blobmsg_add_u64(&b, "dhcp_discarded_packets", stats.discarded_packets);
+	blobmsg_add_u64(&b, "dhcp_transmit_failures", stats.transmit_failures);
+
+	CHECK(ubus_send_reply(ctx, req, b.head));
+	blob_buf_free(&b);
+
+	return UBUS_STATUS_OK;
+}
+
+static int ubus_handle_reset_stats(_unused struct ubus_context *ctx, _unused struct ubus_object *obj,
+		_unused struct ubus_request_data *req, _unused const char *method,
+		_unused struct blob_attr *msg)
+{
+	dhcpv6_reset_stats();
+
+	return UBUS_STATUS_OK;
+}
+
+
 static int ubus_handle_get_state(struct ubus_context *ctx, _unused struct ubus_object *obj,
 		struct ubus_request_data *req, _unused const char *method,
 		_unused struct blob_attr *msg)