Tell server when ESP is running

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

esp.c

@@ -156,12 +156,35 @@ int print_esp_keys(struct openconnect_info *vpninfo, const char *name, struct es
 	return 0;
 }
 
-int esp_setup(struct openconnect_info *vpninfo, int dtls_attempt_period)
+static int esp_send_probes(struct openconnect_info *vpninfo)
 {
-	int fd;
 	struct pkt *pkt;
 	int pktlen;
 
+	pkt = malloc(sizeof(*pkt) + 1 + vpninfo->pkt_trailer);
+	if (!pkt)
+		return -ENOMEM;
+
+	pkt->len = 1;
+	pkt->data[0] = 0;
+	pktlen = encrypt_esp_packet(vpninfo, pkt);
+	send(vpninfo->dtls_fd, &pkt->esp, pktlen, 0);
+
+	pkt->len = 1;
+	pkt->data[0] = 0;
+	pktlen = encrypt_esp_packet(vpninfo, pkt);
+	send(vpninfo->dtls_fd, &pkt->esp, pktlen, 0);
+
+	free(pkt);
+	time(&vpninfo->new_dtls_started);
+
+	return 0;
+};
+
+int esp_setup(struct openconnect_info *vpninfo, int dtls_attempt_period)
+{
+	int fd;
+
 	if (vpninfo->dtls_state == DTLS_DISABLED ||
 	    vpninfo->dtls_state == DTLS_NOSECRET)
 		return -EINVAL;
@@ -170,34 +193,17 @@ int esp_setup(struct openconnect_info *vpninfo, int dtls_attempt_period)
 	if (fd < 0)
 		return fd;
 
-	pkt = malloc(sizeof(*pkt) + 1 + vpninfo->pkt_trailer);
-	if (!pkt) {
-		closesocket(fd);
-		return -ENOMEM;
-	}
-
 	print_esp_keys(vpninfo, _("incoming"), &vpninfo->esp_in);
 	print_esp_keys(vpninfo, _("outgoing"), &vpninfo->esp_out);
 
 	/* We are not connected until we get an ESP packet back */
-	vpninfo->dtls_state = DTLS_CONNECTING;
+	vpninfo->dtls_state = DTLS_SLEEPING;
 	vpninfo->dtls_fd = fd;
 	monitor_fd_new(vpninfo, dtls);
 	monitor_read_fd(vpninfo, dtls);
 	monitor_except_fd(vpninfo, dtls);
 
-	pkt->len = 1;
-	pkt->data[0] = 0;
-	pktlen = encrypt_esp_packet(vpninfo, pkt);
-	send(fd, &pkt->esp, pktlen, 0);
-
-	pkt->len = 1;
-	pkt->data[0] = 0;
-	pktlen = encrypt_esp_packet(vpninfo, pkt);
-	send(fd, &pkt->esp, pktlen, 0);
-
-	free(pkt);
-	time(&vpninfo->new_dtls_started);
+	esp_send_probes(vpninfo);
 
 	return 0;
 }
@@ -254,9 +260,11 @@ int esp_mainloop(struct openconnect_info *vpninfo, int *timeout)
 		pkt->len = len - 2 - pkt->data[len - 2];
 
 		if (pkt->len  == 1 && pkt->data[0] == 0) {
-			vpn_progress(vpninfo, PRG_INFO,
-				     _("ESP session established with server\n"));
-			vpninfo->dtls_state = DTLS_CONNECTED;
+			if (vpninfo->dtls_state == DTLS_SLEEPING) {
+				vpn_progress(vpninfo, PRG_INFO,
+					     _("ESP session established with server\n"));
+				vpninfo->dtls_state = DTLS_CONNECTING;
+			}
 			continue;
 		}
 		queue_packet(&vpninfo->incoming_queue, pkt);

oncp.c

@@ -908,6 +908,20 @@ static const unsigned char esp_kmp_part2[] = {
 /* And now 0x40 bytes of random secret for encryption and HMAC key */
 
 
+static const struct pkt esp_enable_pkt = {
+	.oncp_hdr = {
+		0x21, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+		0x01, 0x2f, 0x01, 0x00, 0x00, 0x00, 0x01, 0x00,
+		0x00, 0x00, 0x00, 0x00, 0x00, 0x0d
+	},
+	.data = {
+		0x00, 0x06, 0x00, 0x00, 0x00, 0x07, /* Group 6, len 7 */
+		0x00, 0x01, 0x00, 0x00, 0x00, 0x01, /* Attr 1, len 1 */
+		0x01
+	},
+	.len = 13
+};
+
 int oncp_connect(struct openconnect_info *vpninfo)
 {
 	int ret, ofs, kmp, kmpend, kmplen, attr, attrlen, group, grouplen, groupend;
@@ -1447,13 +1461,14 @@ int oncp_mainloop(struct openconnect_info *vpninfo, int *timeout)
 		/* Don't free the 'special' packets */
 		if (vpninfo->current_ssl_pkt == vpninfo->deflate_pkt)
 			free(vpninfo->pending_deflated_pkt);
-		else
-#if 0 /* No DPD or keepalive for Juniper yet */
-		if (vpninfo->current_ssl_pkt != &dpd_pkt &&
-		    vpninfo->current_ssl_pkt != &dpd_resp_pkt &&
-		    vpninfo->current_ssl_pkt != &keepalive_pkt)
-#endif
+		else if (vpninfo->current_ssl_pkt == &esp_enable_pkt) {
+			/* If we sent the special ESP enable packet, ESP
+			 * is now enabled. And we don't need to free it. */
+			if (vpninfo->dtls_state == DTLS_CONNECTING)
+				vpninfo->dtls_state = DTLS_CONNECTED;
+		} else {
 			free(vpninfo->current_ssl_pkt);
+		}
 		vpninfo->current_ssl_pkt = NULL;
 	}
 
@@ -1528,6 +1543,10 @@ int oncp_mainloop(struct openconnect_info *vpninfo, int *timeout)
 	}
 #endif
 
+	if (vpninfo->dtls_state == DTLS_CONNECTING) {
+		vpninfo->current_ssl_pkt = (struct pkt *)&esp_enable_pkt;
+		goto handle_outgoing;
+	}
 	/* Service outgoing packet queue, if no DTLS */
 	while (vpninfo->dtls_state != DTLS_CONNECTED && vpninfo->outgoing_queue) {
 		struct pkt *this = vpninfo->outgoing_queue;

openconnect-internal.h

@@ -155,9 +155,9 @@ struct pkt {
 #define DTLS_NOSECRET	0
 #define DTLS_SECRET	1
 #define DTLS_DISABLED	2
-#define DTLS_SLEEPING	3
-#define DTLS_CONNECTING	4
-#define DTLS_CONNECTED	5
+#define DTLS_SLEEPING	3	/* For ESP, sometimes sending probes */
+#define DTLS_CONNECTING	4	/* ESP probe received; must tell server */
+#define DTLS_CONNECTED	5	/* Server informed and should be sending ESP */
 
 #define COMPR_DEFLATE	(1<<0)
 #define COMPR_LZS	(1<<1)