[PATCH 1/1] ppp: Add MAX_IPCP_FAILURE to avoid timeout quickly

[Zhenhua Zhang]

We use IPCP NAK response to stall the progress of acquiring the client
IP address from DHCP server. So we need to increase the max failure of
NAKs in IPCP handshaking.
---
 gatchat/ppp_cp.c   |    8 ++++++--
 gatchat/ppp_cp.h   |    2 +-
 gatchat/ppp_ipcp.c |   10 +++++++++-
 gatchat/ppp_lcp.c  |    2 +-
 4 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/gatchat/ppp_cp.c b/gatchat/ppp_cp.c
index 647e241..e013283 100644
--- a/gatchat/ppp_cp.c
+++ b/gatchat/ppp_cp.c
@@ -997,7 +997,7 @@ void pppcp_set_local_options(struct pppcp_data *pppcp,
 }
 
 struct pppcp_data *pppcp_new(GAtPPP *ppp, const struct pppcp_proto *proto,
-				gboolean dormant)
+				gboolean dormant, int max_failure)
 {
 	struct pppcp_data *data;
 
@@ -1016,7 +1016,11 @@ struct pppcp_data *pppcp_new(GAtPPP *ppp, const struct pppcp_proto *proto,
 	data->terminate_timer_data.max_counter = MAX_TERMINATE;
 	data->config_timer_data.data = data;
 	data->terminate_timer_data.data = data;
-	data->max_failure = MAX_FAILURE;
+
+	if (max_failure)
+		data->max_failure = max_failure;
+	else
+		data->max_failure = MAX_FAILURE;
 
 	data->ppp = ppp;
 	data->driver = proto;
diff --git a/gatchat/ppp_cp.h b/gatchat/ppp_cp.h
index 56a20e0..1e69562 100644
--- a/gatchat/ppp_cp.h
+++ b/gatchat/ppp_cp.h
@@ -104,7 +104,7 @@ guint8 ppp_option_iter_get_length(struct ppp_option_iter *iter);
 const guint8 *ppp_option_iter_get_data(struct ppp_option_iter *iter);
 
 struct pppcp_data *pppcp_new(GAtPPP *ppp, const struct pppcp_proto *proto,
-				gboolean dormant);
+				gboolean dormant, int max_failure);
 void pppcp_free(struct pppcp_data *data);
 
 void pppcp_set_data(struct pppcp_data *pppcp, gpointer data);
diff --git a/gatchat/ppp_ipcp.c b/gatchat/ppp_ipcp.c
index d64bded..3aa9eec 100644
--- a/gatchat/ppp_ipcp.c
+++ b/gatchat/ppp_ipcp.c
@@ -63,6 +63,8 @@ enum ipcp_option_types {
 #define REQ_OPTION_NBNS1	0x08
 #define REQ_OPTION_NBNS2	0x10
 
+#define MAX_IPCP_FAILURE	100
+
 struct ipcp_data {
 	guint8 options[MAX_CONFIG_OPTION_SIZE];
 	guint16 options_len;
@@ -472,7 +474,13 @@ struct pppcp_data *ipcp_new(GAtPPP *ppp, gboolean is_server, guint32 ip)
 	if (!ipcp)
 		return NULL;
 
-	pppcp = pppcp_new(ppp, &ipcp_proto, FALSE);
+	/*
+	 * Some 3G modems use repeated IPCP NAKs as the way of stalling
+	 * util sending us the client IP address. So we increase the
+	 * default number of NAKs we accept before start treating them
+	 * as rejects.
+	 */
+	pppcp = pppcp_new(ppp, &ipcp_proto, FALSE, MAX_IPCP_FAILURE);
 	if (!pppcp) {
 		g_printerr("Failed to allocate PPPCP struct\n");
 		g_free(ipcp);
diff --git a/gatchat/ppp_lcp.c b/gatchat/ppp_lcp.c
index 3cfab5c..5838ebd 100644
--- a/gatchat/ppp_lcp.c
+++ b/gatchat/ppp_lcp.c
@@ -313,7 +313,7 @@ struct pppcp_data *lcp_new(GAtPPP *ppp, gboolean is_server)
 	if (!lcp)
 		return NULL;
 
-	pppcp = pppcp_new(ppp, &lcp_proto, is_server);
+	pppcp = pppcp_new(ppp, &lcp_proto, is_server, 0);
 	if (!pppcp) {
 		g_free(lcp);
 		return NULL;
-- 
1.6.3.3