PXE: add dhcp option support for better pxe support
"MAGIC" - 208 - An option whose presence and content verifies to
the PXELINUX bootloader that the options numbered 209-211 are for
the purpose as described herein.
"ConfigFile" - 209 - Configures the path/filename component of the
configuration file's location, which this bootloader should use to
configure itself.
"PathPrefix" - 210 - Configures a value to be prepended to the
ConfigFile to discern the directory location of the file.
"RebootTime" - 211 - Configures a timeout after which the
bootstrap program will reboot the system (most likely returning it
to PXE).
Signed-off-by: Justin L Werner <justin.werner@caononical.com>
Signed-off-by: John Rigby <john.rigby@linaro.org>
diff --git a/net/magic.c b/net/magic.c
new file mode 100644
index 0000000..59fff92
--- /dev/null
+++ b/net/magic.c
@@ -0,0 +1,242 @@
+/*
+ * magic.c
+ * Copyright (c) 2012 Canonical LTD.
+ * Author: Justin L Werner <justin.werner@caononical.com>
+ * See: RFC 5071
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 (at your option) 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ *
+ */
+
+#include <common.h>
+#include <command.h>
+#include <net.h>
+#include "bootp.h"
+
+#include <linux/compiler.h>
+
+#if defined(CONFIG_BOOTP_VENDOREX) && defined(CONFIG_BOOTP_VENDOREX_PXE_SHARED)
+#include "magic.h"
+
+#define OPT_MAGIC 208
+#define OPT_CONFIG_FILE 209
+#define OPT_PATH_PREFIX 210
+#define OPT_REBOOT_TIME 211
+
+#define OPT_MAGIC_LEN 4
+#define OPT_REBOOT_TIME_LEN 4
+
+
+static const u8 opt_magic_string[] = {0xf1, 0x0, 0x74, 0x7e};
+
+static int opt_magic_seen = 0;
+static u8 opt_config_file_value[UCHAR_MAX + 1];
+static u8 opt_path_prefix_value[UCHAR_MAX + 1];
+static size_t opt_reboot_time = 0;
+
+static u8 *parse_magic(u8 *);
+static u8 *parse_config_file(u8 *);
+static u8 *parse_path_prefix(u8 *);
+static u8 *parse_reboot_time(u8 *);
+
+
+/*
+ * Init/done processing any vendor extension options that we care
+ * about here. It is possible (at least in my env) for the PXE options
+ * processing to occur more than once.
+ */
+void
+dhcp_vendorex_opts_done(void)
+{
+ opt_magic_seen = 0;
+ memset(opt_config_file_value, 0, sizeof(opt_config_file_value));
+ memset(opt_path_prefix_value, 0, sizeof(opt_path_prefix_value));
+ opt_reboot_time = 0;
+}
+
+/*
+ * Add vendor option(s) to the request
+ * - add own opts and return e as ptr just beyond them
+ *
+ * For our common PXE MAGIC implementation, we don't add anything: it's a noop
+ */
+u8 *
+dhcp_vendorex_prep (u8 *e)
+{
+ return e;
+}
+
+/*
+ * Parse vendor options from a response
+ * - e points into the bp_vend[] array, which is OPT_SIZE
+ * returns next 'e' if recognized and accepted, NULL otherwise
+ */
+u8 *
+dhcp_vendorex_proc (u8 *e)
+{
+ switch (*e) {
+ case OPT_MAGIC:
+ printf("INFO: DHCP PXE vendorex PXE MAGIC option encountered\n");
+ e = parse_magic(++e);
+ break;
+
+ case OPT_CONFIG_FILE:
+ printf("INFO: DHCP PXE vendorex PXE ConfigFile option encountered\n");
+ e = parse_config_file(++e);
+ break;
+
+ case OPT_PATH_PREFIX:
+ printf("INFO: DHCP PXE vendorex PXE PathPrefix option encountered\n");
+ e = parse_path_prefix(++e);
+ break;
+
+ case OPT_REBOOT_TIME:
+ printf("INFO: DHCP PXE vendorex RebootTime option encountered\n");
+ e = parse_reboot_time(++e);
+ break;
+
+ default:
+ e = NULL;
+ break;
+ }
+
+ return e;
+}
+
+static u8 *
+parse_magic(u8 *e)
+{
+ size_t len = *e++;
+
+ if (opt_magic_seen) {
+ printf("INFO: DHCP PXE vendorex MAGIC option already seen\n");
+ }
+
+ if (len != OPT_MAGIC_LEN) {
+ e = NULL;
+ printf("ERROR: DHCP PXE vendorex MAGIC has invalid length [%u]\n", len);
+
+ } else if (memcmp(e, opt_magic_string, sizeof(opt_magic_string))) {
+ e = NULL;
+ opt_magic_seen = 0;
+ printf("ERROR: DHCP PXE vendorex MAGIC invalid magic value %02x:%02x:%02x:%02x\n",
+ (unsigned int) e[0], (unsigned int) e[1], (unsigned int) e[2], (unsigned int) e[3]);
+
+ } else {
+ e += sizeof(opt_magic_string);
+ opt_magic_seen = 1;
+ printf("INFO: DHCP PXE vendorex MAGIC confirmed\n");
+ }
+
+ return e;
+}
+
+static u8 *
+parse_config_file(u8 *e)
+{
+ size_t len = *e++;
+
+ if (! opt_magic_seen) {
+ printf("ERROR: DHCP PXE vendorex ConfigFile without MAGIC\n");
+ e = NULL;
+
+ } else if (len == 0) {
+ printf("WARNING: DHCP PXE vendorex ConfigFile string has zero length, ignoring\n");
+
+ } else {
+ memset(opt_config_file_value, 0, sizeof(opt_config_file_value));
+ memcpy(opt_config_file_value, e, len);
+ e += len;
+ opt_config_file_value[len] = 0;
+ setenv(PXE_CONFIG_FILE, (char *)opt_config_file_value);
+ printf("INFO: DHCP PXE vendorex ConfigFile is [%s]\n", opt_config_file_value);
+ }
+
+ return e;
+}
+
+static u8 *
+parse_path_prefix(u8 *e)
+{
+ size_t len = *e++;
+
+ if (! opt_magic_seen) {
+ printf("ERROR: DHCP PXE vendorex ConfigFile without MAGIC\n");
+ e = NULL;
+
+ } if (len == 0) {
+ printf("WARNING: DHCP PXE vendorex PathPrefix string has zero length, ignoring\n");
+
+ } else {
+ memset(opt_path_prefix_value, 0, sizeof(opt_path_prefix_value));
+ memcpy(opt_path_prefix_value, e, len);
+ e += len;
+ opt_path_prefix_value[len] = 0;
+ setenv(PXE_PATH_PREFIX, (char *)opt_path_prefix_value);
+ printf("INFO: DHCP PXE vendorex PathPrefix is [%s]\n", opt_path_prefix_value);
+ }
+
+ return e;
+}
+
+static u8 *
+parse_reboot_time(u8 *e)
+{
+ size_t len = *e++;
+ char bfr[12];
+
+ if (! opt_magic_seen) {
+ printf("ERROR: DHCP PXE vendorex ConfigFile without MAGIC\n");
+ e = NULL;
+
+ } else if (len != OPT_REBOOT_TIME_LEN) {
+ e += len;
+ printf("WARNING: DHCP PXE vendorex RebootTime has invalid length [%u], ignoring\n", len);
+
+ } else {
+ unsigned long value;
+
+ memcpy(&value, e, OPT_REBOOT_TIME_LEN);
+ opt_reboot_time = (size_t) ntohl(value);
+ e += OPT_REBOOT_TIME_LEN;
+
+ sprintf(bfr, "%u", opt_reboot_time);
+ setenv(PXE_REBOOT_TIME, bfr);
+
+ printf("INFO: DHCP PXE vendorex RebootTime is [%u]\n", opt_reboot_time);
+
+#if defined(CONFIG_BOOT_RETRY_TIME)
+ if (opt_reboot_time < CONFIG_BOOT_RETRY_MIN) {
+ opt_reboot_time = CONFIG_BOOT_RETRY_MIN;
+ sprintf(bfr, "%u", opt_reboot_time);
+ setenv(PXE_REBOOT_TIME, bfr);
+ printf("INFO: DHCP PXE vendorex RebootTime adjusted up to allowable minimum value [%d]\n",
+ CONFIG_BOOT_RETRY_MIN);
+ }
+ reset_cmd_timeout();
+#else
+ printf("INFO: DHCP PXE vendorex RebootTime is N/A and ignored due to u-boot configs\n");
+#endif
+ }
+
+ return e;
+}
+#else
+const int no_arm_vendorex_options = 1;
+#endif