[dhcp] Split PXE menuing code out of dhcp.c

The DHCP client code now implements only the mechanism of the DHCP and
PXE Boot Server protocols.  Boot Server Discovery can be initiated
manually using the "pxebs" command.  The menuing code is separated out
into a user-level function on a par with boot_root_path(), and is
entered in preference to a normal filename boot if the DHCP vendor
class is "PXEClient" and the PXE boot menu option exists.

1 files changed, 71 insertions, 7 deletions

diff --git a/src/net/dhcppkt.c b/src/net/dhcppkt.c
index c8bf215..1f2d373 100644
--- a/src/net/dhcppkt.c
+++ b/src/net/dhcppkt.c
@@ -32,6 +32,12 @@
  *
  */
 
+/****************************************************************************
+ *
+ * DHCP packet raw interface
+ *
+ */
+
 /**
  * Calculate used length of an IPv4 field within a DHCP packet
  *
@@ -193,21 +199,79 @@ int dhcppkt_fetch ( struct dhcp_packet *dhcppkt, unsigned int tag,
 	return dhcpopt_fetch ( &dhcppkt->options, tag, data, len );
 }
 
+/****************************************************************************
+ *
+ * DHCP packet settings interface
+ *
+ */
+
+/**
+ * Store value of DHCP setting
+ *
+ * @v settings		Settings block
+ * @v setting		Setting to store
+ * @v data		Setting data, or NULL to clear setting
+ * @v len		Length of setting data
+ * @ret rc		Return status code
+ */
+static int dhcppkt_settings_store ( struct settings *settings,
+				    struct setting *setting,
+				    const void *data, size_t len ) {
+	struct dhcp_packet *dhcppkt =
+		container_of ( settings, struct dhcp_packet, settings );
+
+	return dhcppkt_store ( dhcppkt, setting->tag, data, len );
+}
+
+/**
+ * Fetch value of DHCP setting
+ *
+ * @v settings		Settings block, or NULL to search all blocks
+ * @v setting		Setting to fetch
+ * @v data		Buffer to fill with setting data
+ * @v len		Length of buffer
+ * @ret len		Length of setting data, or negative error
+ */
+static int dhcppkt_settings_fetch ( struct settings *settings,
+				    struct setting *setting,
+				    void *data, size_t len ) {
+	struct dhcp_packet *dhcppkt =
+		container_of ( settings, struct dhcp_packet, settings );
+
+	return dhcppkt_fetch ( dhcppkt, setting->tag, data, len );
+}
+
+/** DHCP settings operations */
+static struct settings_operations dhcppkt_settings_operations = {
+	.store = dhcppkt_settings_store,
+	.fetch = dhcppkt_settings_fetch,
+};
+
+/****************************************************************************
+ *
+ * Constructor
+ *
+ */
+
 /**
- * Initialise prepopulated DHCP packet
+ * Initialise DHCP packet
  *
- * @v dhcppkt		Uninitialised DHCP packet
- * @v data		Memory for DHCP packet data
- * @v max_len		Length of memory for DHCP packet data
+ * @v dhcppkt		DHCP packet structure to fill in
+ * @v data		DHCP packet raw data
+ * @v max_len		Length of raw data buffer
  *
- * The memory content must already be filled with valid DHCP options.
- * A zeroed block counts as a block of valid DHCP options.
+ * Initialise a DHCP packet structure from a data buffer containing a
+ * DHCP packet.
  */
-void dhcppkt_init ( struct dhcp_packet *dhcppkt, void *data, size_t len ) {
+void dhcppkt_init ( struct dhcp_packet *dhcppkt, struct dhcphdr *data,
+		    size_t len ) {
 	dhcppkt->dhcphdr = data;
 	dhcppkt->max_len = len;
 	dhcpopt_init ( &dhcppkt->options, &dhcppkt->dhcphdr->options,
 		       ( len - offsetof ( struct dhcphdr, options ) ) );
 	dhcppkt->len = ( offsetof ( struct dhcphdr, options ) +
 			 dhcppkt->options.len );
+	settings_init ( &dhcppkt->settings,
+			&dhcppkt_settings_operations, &dhcppkt->refcnt,
+			DHCP_SETTINGS_NAME, 0 );
 }