1 files changed, 283 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/gpxe/src/net/dhcppkt.c b/contrib/syslinux-4.02/gpxe/src/net/dhcppkt.c
new file mode 100644
index 0000000..20a0e66
--- /dev/null
+++ b/contrib/syslinux-4.02/gpxe/src/net/dhcppkt.c
@@ -0,0 +1,283 @@
+/*
+ * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <string.h>
+#include <gpxe/netdevice.h>
+#include <gpxe/dhcp.h>
+#include <gpxe/dhcpopts.h>
+#include <gpxe/dhcppkt.h>
+
+/** @file
+ *
+ * DHCP packets
+ *
+ */
+
+/****************************************************************************
+ *
+ * DHCP packet raw interface
+ *
+ */
+
+/**
+ * Calculate used length of an IPv4 field within a DHCP packet
+ *
+ * @v data		Field data
+ * @v len		Length of field
+ * @ret used		Used length of field
+ */
+static size_t used_len_ipv4 ( const void *data, size_t len __unused ) {
+	const struct in_addr *in = data;
+
+	return ( in->s_addr ? sizeof ( *in ) : 0 );
+}
+
+/**
+ * Calculate used length of a string field within a DHCP packet
+ *
+ * @v data		Field data
+ * @v len		Length of field
+ * @ret used		Used length of field
+ */
+static size_t used_len_string ( const void *data, size_t len ) {
+	return strnlen ( data, len );
+}
+
+/** A dedicated field within a DHCP packet */
+struct dhcp_packet_field {
+	/** Settings tag number */
+	unsigned int tag;
+	/** Offset within DHCP packet */
+	uint16_t offset;
+	/** Length of field */
+	uint16_t len;
+	/** Calculate used length of field
+	 *
+	 * @v data	Field data
+	 * @v len	Length of field
+	 * @ret used	Used length of field
+	 */
+	size_t ( * used_len ) ( const void *data, size_t len );
+};
+
+/** Declare a dedicated field within a DHCP packet
+ *
+ * @v _tag		Settings tag number
+ * @v _field		Field name
+ * @v _used_len		Function to calculate used length of field
+ */
+#define DHCP_PACKET_FIELD( _tag, _field, _used_len ) {			\
+		.tag = (_tag),						\
+		.offset = offsetof ( struct dhcphdr, _field ),		\
+		.len = sizeof ( ( ( struct dhcphdr * ) 0 )->_field ),	\
+		.used_len = _used_len,					\
+	}
+
+/** Dedicated fields within a DHCP packet */
+static struct dhcp_packet_field dhcp_packet_fields[] = {
+	DHCP_PACKET_FIELD ( DHCP_EB_YIADDR, yiaddr, used_len_ipv4 ),
+	DHCP_PACKET_FIELD ( DHCP_EB_SIADDR, siaddr, used_len_ipv4 ),
+	DHCP_PACKET_FIELD ( DHCP_TFTP_SERVER_NAME, sname, used_len_string ),
+	DHCP_PACKET_FIELD ( DHCP_BOOTFILE_NAME, file, used_len_string ),
+};
+
+/**
+ * Get address of a DHCP packet field
+ *
+ * @v dhcphdr		DHCP packet header
+ * @v field		DHCP packet field
+ * @ret data		Packet field data
+ */
+static inline void * dhcp_packet_field ( struct dhcphdr *dhcphdr,
+					 struct dhcp_packet_field *field ) {
+	return ( ( ( void * ) dhcphdr ) + field->offset );
+}
+
+/**
+ * Find DHCP packet field corresponding to settings tag number
+ *
+ * @v tag		Settings tag number
+ * @ret field		DHCP packet field, or NULL
+ */
+static struct dhcp_packet_field *
+find_dhcp_packet_field ( unsigned int tag ) {
+	struct dhcp_packet_field *field;
+	unsigned int i;
+
+	for ( i = 0 ; i < ( sizeof ( dhcp_packet_fields ) /
+			    sizeof ( dhcp_packet_fields[0] ) ) ; i++ ) {
+		field = &dhcp_packet_fields[i];
+		if ( field->tag == tag )
+			return field;
+	}
+	return NULL;
+}
+
+/**
+ * Store value of DHCP packet setting
+ *
+ * @v dhcppkt		DHCP packet
+ * @v tag		Setting tag number
+ * @v data		Setting data, or NULL to clear setting
+ * @v len		Length of setting data
+ * @ret rc		Return status code
+ */
+int dhcppkt_store ( struct dhcp_packet *dhcppkt, unsigned int tag,
+		    const void *data, size_t len ) {
+	struct dhcp_packet_field *field;
+	void *field_data;
+	int rc;
+
+	/* If this is a special field, fill it in */
+	if ( ( field = find_dhcp_packet_field ( tag ) ) != NULL ) {
+		if ( len > field->len )
+			return -ENOSPC;
+		field_data = dhcp_packet_field ( dhcppkt->dhcphdr, field );
+		memset ( field_data, 0, field->len );
+		memcpy ( dhcp_packet_field ( dhcppkt->dhcphdr, field ),
+			 data, len );
+		/* Erase any equivalent option from the options block */
+		dhcpopt_store ( &dhcppkt->options, tag, NULL, 0 );
+		return 0;
+	}
+
+	/* Otherwise, use the generic options block */
+	rc = dhcpopt_store ( &dhcppkt->options, tag, data, len );
+
+	/* Update our used-length field */
+	dhcppkt->len = ( offsetof ( struct dhcphdr, options ) +
+			 dhcppkt->options.len );
+
+	return rc;
+}
+
+/**
+ * Fetch value of DHCP packet setting
+ *
+ * @v dhcppkt		DHCP packet
+ * @v tag		Setting tag number
+ * @v data		Buffer to fill with setting data
+ * @v len		Length of buffer
+ * @ret len		Length of setting data, or negative error
+ */
+int dhcppkt_fetch ( struct dhcp_packet *dhcppkt, unsigned int tag,
+		    void *data, size_t len ) {
+	struct dhcp_packet_field *field;
+	void *field_data;
+	size_t field_len = 0;
+	
+	/* Identify special field, if any */
+	if ( ( field = find_dhcp_packet_field ( tag ) ) != NULL ) {
+		field_data = dhcp_packet_field ( dhcppkt->dhcphdr, field );
+		field_len = field->used_len ( field_data, field->len );
+	}
+
+	/* Return special field, if it exists and is populated */
+	if ( field_len ) {
+		if ( len > field_len )
+			len = field_len;
+		memcpy ( data, field_data, len );
+		return field_len;
+	}
+
+	/* Otherwise, use the generic options block */
+	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 DHCP packet
+ *
+ * @v dhcppkt		DHCP packet structure to fill in
+ * @v data		DHCP packet raw data
+ * @v max_len		Length of raw data buffer
+ *
+ * Initialise a DHCP packet structure from a data buffer containing a
+ * DHCP packet.
+ */
+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 );
+}