Extend DHCP timeou

Per Alex Williamson <alex.williamson@redhat.com>: For discovery, both the DHCP and PXE specs suggest timeouts of 4, 8, 16, and 32 seconds. This gives us a maximum timeout of 60 seconds, versus the current timeout of 15 seconds at timeouts of 1, 2, 4, and 8 seconds. On the request phase, the specs are quite different. RFC2131 for DHCP suggests the same intervals as above for discovery, while the PXE spec recommends intervals of 1, 2, 3, and 4 seconds. Our timer only wants to do exponential back-off, so we compromise and adjust to intervals of 1, 2, 4, and 8 seconds. PXE boot server discovery appears to want the same timeouts as the DHCP request phase.
ipxe · Mar 7, 2014 · 2058e73 · 2058e73
1 parent ab7d5e8
commit 2058e73
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Showing 2 changed files with 12 additions and 13 deletions.
diff --git a/src/include/ipxe/dhcp.h b/src/include/ipxe/dhcp.h
@@ -643,10 +643,6 @@ struct dhcphdr {
  */
 #define DHCP_MIN_LEN 552
 
-/** Timeouts for sending DHCP packets */
-#define DHCP_MIN_TIMEOUT ( 1 * TICKS_PER_SEC )
-#define DHCP_MAX_TIMEOUT ( 10 * TICKS_PER_SEC )
-
 /** Maximum time that we will wait for ProxyDHCP responses */
 #define PROXYDHCP_MAX_TIMEOUT ( 2 * TICKS_PER_SEC )
 

diff --git a/src/net/udp/dhcp.c b/src/net/udp/dhcp.c
@@ -185,8 +185,8 @@ struct dhcp_session_state {
 	void ( * expired ) ( struct dhcp_session *dhcp );
 	/** Transmitted message type */
 	uint8_t tx_msgtype;
-	/** Apply minimum timeout */
-	uint8_t apply_min_timeout;
+    uint8_t min_timeout;
+    uint8_t max_timeout;
 };
 
 static struct dhcp_session_state dhcp_state_discover;
@@ -286,9 +286,8 @@ static void dhcp_set_state ( struct dhcp_session *dhcp,
 	dhcp->state = state;
 	dhcp->start = currticks();
 	stop_timer ( &dhcp->timer );
-	dhcp->timer.min_timeout =
-		( state->apply_min_timeout ? DHCP_MIN_TIMEOUT : 0 );
-	dhcp->timer.max_timeout = DHCP_MAX_TIMEOUT;
+    dhcp->timer.min_timeout = state->min_timeout * TICKS_PER_SEC;
+    dhcp->timer.max_timeout = state->max_timeout * TICKS_PER_SEC;
 	start_timer_nodelay ( &dhcp->timer );
 }
 
@@ -461,7 +460,8 @@ static struct dhcp_session_state dhcp_state_discover = {
 	.rx			= dhcp_discovery_rx,
 	.expired		= dhcp_discovery_expired,
 	.tx_msgtype		= DHCPDISCOVER,
-	.apply_min_timeout	= 1,
+    .min_timeout    = 4,
+    .max_timeout    = 32,
 };
 
 /**
@@ -598,7 +598,8 @@ static struct dhcp_session_state dhcp_state_request = {
 	.rx			= dhcp_request_rx,
 	.expired		= dhcp_request_expired,
 	.tx_msgtype		= DHCPREQUEST,
-	.apply_min_timeout	= 0,
+    .min_timeout    = 1,
+    .max_timeout    = 8,
 };
 
 /**
@@ -699,7 +700,8 @@ static struct dhcp_session_state dhcp_state_proxy = {
 	.rx			= dhcp_proxy_rx,
 	.expired		= dhcp_proxy_expired,
 	.tx_msgtype		= DHCPREQUEST,
-	.apply_min_timeout	= 0,
+    .min_timeout    = 1,
+    .max_timeout    = 8,
 };
 
 /**
@@ -846,7 +848,8 @@ static struct dhcp_session_state dhcp_state_pxebs = {
 	.rx			= dhcp_pxebs_rx,
 	.expired		= dhcp_pxebs_expired,
 	.tx_msgtype		= DHCPREQUEST,
-	.apply_min_timeout	= 1,
+    .min_timeout    = 1,
+    .max_timeout    = 8,
 };
 
 /****************************************************************************