library: Add new callback for obtaining TX/RX statistics

The UI may want to periodically request byte/packet counts from the
library without exiting the mainloop.  So we'll allow it to write
OC_CMD_STATS to the cmd_fd and then receive a callback.

Signed-off-by: Kevin Cernekee <cernekee@gmail.com>

libopenconnect.map.in

@@ -51,6 +51,7 @@ OPENCONNECT_3.1 {
 	openconnect_set_protect_socket_handler;
 	openconnect_set_mobile_info;
 	openconnect_set_xmlpost;
+	openconnect_set_stats_handler;
 } OPENCONNECT_3.0;
 
 OPENCONNECT_PRIVATE {

library.c

@@ -556,3 +556,9 @@ void openconnect_set_protect_socket_handler(struct openconnect_info *vpninfo,
 {
 	vpninfo->protect_socket = protect_socket;
 }
+
+void openconnect_set_stats_handler(struct openconnect_info *vpninfo,
+				   openconnect_stats_vfn stats_handler)
+{
+	vpninfo->stats_handler = stats_handler;
+}

openconnect-internal.h

@@ -288,6 +288,8 @@ struct openconnect_info {
 	struct pkt *outgoing_queue;
 	int outgoing_qlen;
 	int max_qlen;
+	struct oc_stats stats;
+	openconnect_stats_vfn stats_handler;
 
 	socklen_t peer_addrlen;
 	struct sockaddr *peer_addr;

openconnect.h

@@ -187,6 +187,13 @@ struct oc_vpn_option {
 	struct oc_vpn_option *next;
 };
 
+struct oc_stats {
+	uint64_t tx_pkts;
+	uint64_t tx_bytes;
+	uint64_t rx_pkts;
+	uint64_t rx_bytes;
+};
+
 /****************************************************************************/
 
 #define PRG_ERR		0
@@ -197,6 +204,7 @@ struct oc_vpn_option {
 /* byte commands to write into the cmd_fd */
 #define OC_CMD_CANCEL		'x'
 #define OC_CMD_PAUSE		'p'
+#define OC_CMD_STATS		's'
 
 #define RECONNECT_INTERVAL_MIN	10
 #define RECONNECT_INTERVAL_MAX	100
@@ -378,6 +386,12 @@ typedef void (*openconnect_protect_socket_vfn) (void *privdata, int fd);
 void openconnect_set_protect_socket_handler(struct openconnect_info *vpninfo,
 					    openconnect_protect_socket_vfn protect_socket);
 
+/* Callback for obtaining traffic stats via OC_CMD_STATS.
+ */
+typedef void (*openconnect_stats_vfn) (void *privdata, const struct oc_stats *stats);
+void openconnect_set_stats_handler(struct openconnect_info *vpninfo,
+				   openconnect_stats_vfn stats_handler);
+
 /* SSL certificate capabilities. openconnect_has_pkcs11_support() means that we
    can accept PKCS#11 URLs in place of filenames, for the certificate and key. */
 int openconnect_has_pkcs11_support(void);

ssl.c

@@ -554,6 +554,9 @@ void check_cmd_fd(struct openconnect_info *vpninfo, fd_set *fds)
 	case OC_CMD_PAUSE:
 		vpninfo->got_pause_cmd = 1;
 		break;
+	case OC_CMD_STATS:
+		if (vpninfo->stats_handler)
+			vpninfo->stats_handler(vpninfo->cbdata, &vpninfo->stats);
 	}
 }
 

tun.c

@@ -736,6 +736,9 @@ int tun_mainloop(struct openconnect_info *vpninfo, int *timeout)
 				break;
 			out_pkt->len = len - prefix_size;
 
+			vpninfo->stats.tx_pkts++;
+			vpninfo->stats.tx_bytes += out_pkt->len;
+
 			queue_packet(&vpninfo->outgoing_queue, out_pkt);
 			out_pkt = NULL;
 
@@ -758,6 +761,9 @@ int tun_mainloop(struct openconnect_info *vpninfo, int *timeout)
 		unsigned char *data = this->data;
 		int len = this->len;
 
+		vpninfo->stats.rx_pkts++;
+		vpninfo->stats.rx_bytes += len;
+
 #ifdef TUN_HAS_AF_PREFIX
 		if (!vpninfo->script_tun) {
 			struct ip *iph = (void *)data;