From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Paulo Flabiano Smorigo <pfsmorigo@br.ibm.com>
Date: Tue, 27 Nov 2012 17:22:07 -0200
Subject: [PATCH] Search for specific config file for netboot
This patch implements a search for a specific configuration when the config
file is on a remoteserver. It uses the following order:
1) DHCP client UUID option.
2) MAC address (in lower case hexadecimal with dash separators);
3) IP (in upper case hexadecimal) or IPv6;
4) The original grub.cfg file.
This procedure is similar to what is used by pxelinux and yaboot:
http://www.syslinux.org/wiki/index.php/PXELINUX#config
This should close the bugzilla:
https://bugzilla.redhat.com/show_bug.cgi?id=873406
---
grub-core/net/net.c | 118 ++++++++++++++++++++++++++++++++++++++++++++++++
grub-core/normal/main.c | 18 ++++++--
include/grub/net.h | 3 ++
3 files changed, 135 insertions(+), 4 deletions(-)
diff --git a/grub-core/net/net.c b/grub-core/net/net.c
index 10773fc34..0769bf850 100644
--- a/grub-core/net/net.c
+++ b/grub-core/net/net.c
@@ -1735,6 +1735,124 @@ grub_net_restore_hw (void)
return GRUB_ERR_NONE;
}
+grub_err_t
+grub_net_search_configfile (char *config)
+{
+ grub_size_t config_len;
+ char *suffix;
+
+ auto int search_through (grub_size_t num_tries, grub_size_t slice_size);
+ int search_through (grub_size_t num_tries, grub_size_t slice_size)
+ {
+ while (num_tries-- > 0)
+ {
+ grub_dprintf ("net", "probe %s\n", config);
+
+ grub_file_t file;
+ file = grub_file_open (config);
+
+ if (file)
+ {
+ grub_file_close (file);
+ grub_dprintf ("net", "found!\n");
+ return 0;
+ }
+ else
+ {
+ if (grub_errno == GRUB_ERR_IO)
+ grub_errno = GRUB_ERR_NONE;
+ }
+
+ if (grub_strlen (suffix) < slice_size)
+ break;
+
+ config[grub_strlen (config) - slice_size] = '\0';
+ }
+
+ return 1;
+ }
+
+ config_len = grub_strlen (config);
+ config[config_len] = '-';
+ suffix = config + config_len + 1;
+
+ struct grub_net_network_level_interface *inf;
+ FOR_NET_NETWORK_LEVEL_INTERFACES (inf)
+ {
+ /* By the Client UUID. */
+
+ char client_uuid_var[sizeof ("net_") + grub_strlen (inf->name) +
+ sizeof ("_clientuuid") + 1];
+ grub_snprintf (client_uuid_var, sizeof (client_uuid_var),
+ "net_%s_clientuuid", inf->name);
+
+ const char *client_uuid;
+ client_uuid = grub_env_get (client_uuid_var);
+
+ if (client_uuid)
+ {
+ grub_strcpy (suffix, client_uuid);
+ if (search_through (1, 0) == 0) return GRUB_ERR_NONE;
+ }
+
+ /* By the MAC address. */
+
+ /* Add ethernet type */
+ grub_strcpy (suffix, "01-");
+
+ grub_net_hwaddr_to_str (&inf->hwaddress, suffix + 3);
+
+ char *ptr;
+ for (ptr = suffix; *ptr; ptr++)
+ if (*ptr == ':')
+ *ptr = '-';
+
+ if (search_through (1, 0) == 0) return GRUB_ERR_NONE;
+
+ /* By IP address */
+
+ switch ((&inf->address)->type)
+ {
+ case GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV4:
+ {
+ grub_uint32_t n = grub_be_to_cpu32 ((&inf->address)->ipv4);
+ grub_snprintf (suffix, GRUB_NET_MAX_STR_ADDR_LEN, "%02X%02X%02X%02X", \
+ ((n >> 24) & 0xff), ((n >> 16) & 0xff), \
+ ((n >> 8) & 0xff), ((n >> 0) & 0xff));
+
+ if (search_through (8, 1) == 0) return GRUB_ERR_NONE;
+ break;
+ }
+ case GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6:
+ {
+ char buf[GRUB_NET_MAX_STR_ADDR_LEN];
+ struct grub_net_network_level_address base;
+ base.type = GRUB_NET_NETWORK_LEVEL_PROTOCOL_IPV6;
+ grub_memcpy (&base.ipv6, ((&inf->address)->ipv6), 16);
+ grub_net_addr_to_str (&base, buf);
+
+ for (ptr = buf; *ptr; ptr++)
+ if (*ptr == ':')
+ *ptr = '-';
+
+ grub_snprintf (suffix, GRUB_NET_MAX_STR_ADDR_LEN, "%s", buf);
+ if (search_through (1, 0) == 0) return GRUB_ERR_NONE;
+ break;
+ }
+ case GRUB_NET_NETWORK_LEVEL_PROTOCOL_DHCP_RECV:
+ return grub_error (GRUB_ERR_BUG, "shouldn't reach here");
+ default:
+ return grub_error (GRUB_ERR_BUG,
+ "unsupported address type %d", (&inf->address)->type);
+ }
+ }
+
+ /* Remove the remaining minus sign at the end. */
+ config[config_len] = '\0';
+
+ return GRUB_ERR_NONE;
+}
+
static struct grub_preboot *fini_hnd;
static grub_command_t cmd_addaddr, cmd_deladdr, cmd_addroute, cmd_delroute;
diff --git a/grub-core/normal/main.c b/grub-core/normal/main.c
index 759c475c4..b2654ef62 100644
--- a/grub-core/normal/main.c
+++ b/grub-core/normal/main.c
@@ -33,6 +33,7 @@
#include <grub/charset.h>
#include <grub/script_sh.h>
#include <grub/bufio.h>
+#include <grub/net.h>
#ifdef GRUB_MACHINE_IEEE1275
#include <grub/ieee1275/ieee1275.h>
#endif
@@ -365,10 +366,19 @@ grub_cmd_normal (struct grub_command *cmd __attribute__ ((unused)),
prefix = grub_env_get ("prefix");
if (prefix)
- {
- config = grub_xasprintf ("%s/grub.cfg", prefix);
- if (! config)
- goto quit;
+ {
+ grub_size_t config_len;
+ config_len = grub_strlen (prefix) +
+ sizeof ("/grub.cfg-XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX");
+ config = grub_malloc (config_len);
+
+ if (! config)
+ goto quit;
+
+ grub_snprintf (config, config_len, "%s/grub.cfg", prefix);
+
+ if (grub_strncmp (prefix + 1, "tftp", sizeof ("tftp") - 1) == 0)
+ grub_net_search_configfile (config);
grub_enter_normal_mode (config);
grub_free (config);
diff --git a/include/grub/net.h b/include/grub/net.h
index e266bae23..50d62ab0c 100644
--- a/include/grub/net.h
+++ b/include/grub/net.h
@@ -566,4 +566,7 @@ extern char *grub_net_default_server;
#define VLANTAG_IDENTIFIER 0x8100
+grub_err_t
+grub_net_search_configfile (char *config);
+
#endif /* ! GRUB_NET_HEADER */