From: Andrei Borzenkov <arvidj...@gmail.com>
Even though we were parsing some DHCP options sent by the server, so far
we are only using the BOOTP 2-way handshake, even when talking to a DHCP
server.
Change this by actually sending out DHCP DISCOVER packets instead of the
generic (mostly empty) BOOTP BOOTREQUEST packets.
A pure BOOTP server would ignore the extra DHCP options in the DISCOVER
packet and would just reply with a BOOTREPLY packet, which we also
handle in the code.
Signed-off-by: Andre Przywara <andre.przyw...@arm.com>
Reviewed-by: Daniel Kiper <daniel.ki...@oracle.com>
---
grub-core/net/bootp.c | 120 +++++++++++++++++++++++++++++++++++++++++-
include/grub/net.h | 2 +
2 files changed, 121 insertions(+), 1 deletion(-)
diff --git a/grub-core/net/bootp.c b/grub-core/net/bootp.c
index d0482a7d5..63763aaab 100644
--- a/grub-core/net/bootp.c
+++ b/grub-core/net/bootp.c
@@ -25,6 +25,48 @@
#include <grub/net/udp.h>
#include <grub/datetime.h>
+struct grub_dhcp_discover_options
+{
+ grub_uint8_t magic[4];
+ struct
+ {
+ grub_uint8_t code;
+ grub_uint8_t len;
+ grub_uint8_t data;
+ } GRUB_PACKED message_type;
+ grub_uint8_t end;
+} GRUB_PACKED;
+
+struct grub_dhcp_request_options
+{
+ grub_uint8_t magic[4];
+ struct
+ {
+ grub_uint8_t code;
+ grub_uint8_t len;
+ grub_uint8_t data;
+ } GRUB_PACKED message_type;
+ struct
+ {
+ grub_uint8_t type;
+ grub_uint8_t len;
+ grub_uint32_t data;
+ } GRUB_PACKED server_identifier;
+ struct
+ {
+ grub_uint8_t type;
+ grub_uint8_t len;
+ grub_uint32_t data;
+ } GRUB_PACKED requested_ip;
+ struct
+ {
+ grub_uint8_t type;
+ grub_uint8_t len;
+ grub_uint8_t data[7];
+ } GRUB_PACKED parameter_request;
+ grub_uint8_t end;
+} GRUB_PACKED;
+
enum
{
GRUB_DHCP_OPT_OVERLOAD_FILE = 1,
@@ -43,6 +85,8 @@ enum
GRUB_DHCP_MESSAGE_INFORM,
};
+#define GRUB_BOOTP_MAX_OPTIONS_SIZE 64
+
/* Max timeout when waiting for BOOTP/DHCP reply */
#define GRUB_DHCP_MAX_PACKET_TIMEOUT 32
@@ -386,6 +430,64 @@ send_dhcp_packet (struct grub_net_network_level_interface
*iface)
grub_net_network_level_address_t target;
grub_net_link_level_address_t ll_target;
+ static struct grub_dhcp_discover_options discover_options =
+ {
+ {
+ GRUB_NET_BOOTP_RFC1048_MAGIC_0,
+ GRUB_NET_BOOTP_RFC1048_MAGIC_1,
+ GRUB_NET_BOOTP_RFC1048_MAGIC_2,
+ GRUB_NET_BOOTP_RFC1048_MAGIC_3,
+ },
+ {
+ GRUB_NET_DHCP_MESSAGE_TYPE,
+ sizeof (discover_options.message_type.data),
+ GRUB_DHCP_MESSAGE_DISCOVER,
+ },
+ GRUB_NET_BOOTP_END,
+ };
+
+ static struct grub_dhcp_request_options request_options =
+ {
+ {
+ GRUB_NET_BOOTP_RFC1048_MAGIC_0,
+ GRUB_NET_BOOTP_RFC1048_MAGIC_1,
+ GRUB_NET_BOOTP_RFC1048_MAGIC_2,
+ GRUB_NET_BOOTP_RFC1048_MAGIC_3,
+ },
+ {
+ GRUB_NET_DHCP_MESSAGE_TYPE,
+ sizeof (request_options.message_type.data),
+ GRUB_DHCP_MESSAGE_REQUEST,
+ },
+ {
+ GRUB_NET_DHCP_SERVER_IDENTIFIER,
+ sizeof (request_options.server_identifier.data),
+ 0,
+ },
+ {
+ GRUB_NET_DHCP_REQUESTED_IP_ADDRESS,
+ sizeof (request_options.requested_ip.data),
+ 0,
+ },
+ {
+ GRUB_NET_DHCP_PARAMETER_REQUEST_LIST,
+ sizeof (request_options.parameter_request.data),
+ {
+ GRUB_NET_BOOTP_NETMASK,
+ GRUB_NET_BOOTP_ROUTER,
+ GRUB_NET_BOOTP_DNS,
+ GRUB_NET_BOOTP_DOMAIN,
+ GRUB_NET_BOOTP_HOSTNAME,
+ GRUB_NET_BOOTP_ROOT_PATH,
+ GRUB_NET_BOOTP_EXTENSIONS_PATH,
+ },
+ },
+ GRUB_NET_BOOTP_END,
+ };
+
+ COMPILE_TIME_ASSERT (sizeof (discover_options) <=
GRUB_BOOTP_MAX_OPTIONS_SIZE);
+ COMPILE_TIME_ASSERT (sizeof (request_options) <=
GRUB_BOOTP_MAX_OPTIONS_SIZE);
+
nb = grub_netbuff_alloc (sizeof (*pack) + GRUB_BOOTP_MAX_OPTIONS_SIZE + 128);
if (!nb)
return grub_errno;
@@ -399,6 +501,19 @@ send_dhcp_packet (struct grub_net_network_level_interface
*iface)
goto out;
grub_memset (nb->data, 0, GRUB_BOOTP_MAX_OPTIONS_SIZE);
+ if (!iface->srv_id)
+ {
+ grub_memcpy (nb->data, &discover_options, sizeof (discover_options));
+ }
+ else
+ {
+ struct grub_dhcp_request_options *ro = (struct grub_dhcp_request_options
*) nb->data;
+
+ grub_memcpy (nb->data, &request_options, sizeof (request_options));
+ /* my_ip and srv_id are stored in network order so do not need
conversion. */
+ grub_set_unaligned32 (&ro->server_identifier.data, iface->srv_id);
+ grub_set_unaligned32 (&ro->requested_ip.data, iface->my_ip);
+ }
err = grub_netbuff_push (nb, sizeof (*pack));
if (err)
@@ -416,7 +531,10 @@ send_dhcp_packet (struct grub_net_network_level_interface
*iface)
t = 0;
}
pack->seconds = grub_cpu_to_be16 (t);
- pack->ident = grub_cpu_to_be32 (t);
+ if (!iface->srv_id)
+ iface->xid = pack->ident = grub_cpu_to_be32 (t);
+ else
+ pack->ident = iface->xid;
grub_memcpy (&pack->mac_addr, &iface->hwaddress.mac, 6);
diff --git a/include/grub/net.h b/include/grub/net.h
index 68a9f1311..4a9069a14 100644
--- a/include/grub/net.h
+++ b/include/grub/net.h
@@ -462,9 +462,11 @@ enum
GRUB_NET_BOOTP_DOMAIN = 0x0f,
GRUB_NET_BOOTP_ROOT_PATH = 0x11,
GRUB_NET_BOOTP_EXTENSIONS_PATH = 0x12,
+ GRUB_NET_DHCP_REQUESTED_IP_ADDRESS = 50,
GRUB_NET_DHCP_OVERLOAD = 52,
GRUB_NET_DHCP_MESSAGE_TYPE = 53,
GRUB_NET_DHCP_SERVER_IDENTIFIER = 54,
+ GRUB_NET_DHCP_PARAMETER_REQUEST_LIST = 55,
GRUB_NET_DHCP_TFTP_SERVER_NAME = 66,
GRUB_NET_DHCP_BOOTFILE_NAME = 67,
GRUB_NET_BOOTP_END = 0xff
--
2.17.1
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