From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Michael Chang <mchang@suse.com>
Date: Thu, 14 Jul 2016 17:48:45 +0800
Subject: [PATCH] efinet: Setting DNS server from UEFI protocol

In the URI device path node, any name rahter than address can be used for
looking up the resources so that DNS service become needed to get answer of the
name's address. Unfortunately the DNS is not defined in any of the device path
nodes so that we use the EFI_IP4_CONFIG2_PROTOCOL and EFI_IP6_CONFIG_PROTOCOL
to obtain it.

These two protcols are defined the sections of UEFI specification.

 27.5 EFI IPv4 Configuration II Protocol
 27.7 EFI IPv6 Configuration Protocol

include/grub/efi/api.h:
Add new structure and protocol UUID of EFI_IP4_CONFIG2_PROTOCOL and
EFI_IP6_CONFIG_PROTOCOL.

grub-core/net/drivers/efi/efinet.c:
Use the EFI_IP4_CONFIG2_PROTOCOL and EFI_IP6_CONFIG_PROTOCOL to obtain the list
of DNS server address for IPv4 and IPv6 respectively. The address of DNS
servers is structured into DHCPACK packet and feed into the same DHCP packet
processing functions to ensure the network interface is setting up the same way
it used to be.

Signed-off-by: Michael Chang <mchang@suse.com>
Signed-off-by: Ken Lin <ken.lin@hpe.com>
---
 grub-core/net/drivers/efi/efinet.c | 163 +++++++++++++++++++++++++++++++++++++
 include/grub/efi/api.h             |  76 +++++++++++++++++
 2 files changed, 239 insertions(+)

diff --git a/grub-core/net/drivers/efi/efinet.c b/grub-core/net/drivers/efi/efinet.c
index 3e51e1064..3d7750747 100644
--- a/grub-core/net/drivers/efi/efinet.c
+++ b/grub-core/net/drivers/efi/efinet.c
@@ -34,6 +34,8 @@ GRUB_MOD_LICENSE ("GPLv3+");
 /* GUID.  */
 static grub_efi_guid_t net_io_guid = GRUB_EFI_SIMPLE_NETWORK_GUID;
 static grub_efi_guid_t pxe_io_guid = GRUB_EFI_PXE_GUID;
+static grub_efi_guid_t ip4_config_guid = GRUB_EFI_IP4_CONFIG2_PROTOCOL_GUID;
+static grub_efi_guid_t ip6_config_guid = GRUB_EFI_IP6_CONFIG_PROTOCOL_GUID;
 
 static grub_err_t
 send_card_buffer (struct grub_net_card *dev,
@@ -333,6 +335,125 @@ grub_efinet_findcards (void)
   grub_free (handles);
 }
 
+static grub_efi_handle_t
+grub_efi_locate_device_path (grub_efi_guid_t *protocol, grub_efi_device_path_t *device_path,
+			    grub_efi_device_path_t **r_device_path)
+{
+  grub_efi_handle_t handle;
+  grub_efi_status_t status;
+
+  status = efi_call_3 (grub_efi_system_table->boot_services->locate_device_path,
+		      protocol, &device_path, &handle);
+
+  if (status != GRUB_EFI_SUCCESS)
+    return 0;
+
+  if (r_device_path)
+    *r_device_path = device_path;
+
+  return handle;
+}
+
+static grub_efi_ipv4_address_t *
+grub_dns_server_ip4_address (grub_efi_device_path_t *dp, grub_efi_uintn_t *num_dns)
+{
+  grub_efi_handle_t hnd;
+  grub_efi_status_t status;
+  grub_efi_ip4_config2_protocol_t *conf;
+  grub_efi_ipv4_address_t *addrs;
+  grub_efi_uintn_t data_size = 1 * sizeof (grub_efi_ipv4_address_t);
+
+  hnd = grub_efi_locate_device_path (&ip4_config_guid, dp, NULL);
+
+  if (!hnd)
+    return 0;
+
+  conf = grub_efi_open_protocol (hnd, &ip4_config_guid,
+				GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+
+  if (!conf)
+    return 0;
+
+  addrs  = grub_malloc (data_size);
+  if (!addrs)
+    return 0;
+
+  status = efi_call_4 (conf->get_data, conf,
+		      GRUB_EFI_IP4_CONFIG2_DATA_TYPE_DNSSERVER,
+		      &data_size, addrs);
+
+  if (status == GRUB_EFI_BUFFER_TOO_SMALL)
+    {
+      grub_free (addrs);
+      addrs  = grub_malloc (data_size);
+      if (!addrs)
+	return 0;
+
+      status = efi_call_4 (conf->get_data,  conf,
+			  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_DNSSERVER,
+			  &data_size, addrs);
+    }
+
+  if (status != GRUB_EFI_SUCCESS)
+    {
+      grub_free (addrs);
+      return 0;
+    }
+
+  *num_dns = data_size / sizeof (grub_efi_ipv4_address_t);
+  return addrs;
+}
+
+static grub_efi_ipv6_address_t *
+grub_dns_server_ip6_address (grub_efi_device_path_t *dp, grub_efi_uintn_t *num_dns)
+{
+  grub_efi_handle_t hnd;
+  grub_efi_status_t status;
+  grub_efi_ip6_config_protocol_t *conf;
+  grub_efi_ipv6_address_t *addrs;
+  grub_efi_uintn_t data_size = 1 * sizeof (grub_efi_ipv6_address_t);
+
+  hnd = grub_efi_locate_device_path (&ip6_config_guid, dp, NULL);
+
+  if (!hnd)
+    return 0;
+
+  conf = grub_efi_open_protocol (hnd, &ip6_config_guid,
+				GRUB_EFI_OPEN_PROTOCOL_GET_PROTOCOL);
+
+  if (!conf)
+    return 0;
+
+  addrs  = grub_malloc (data_size);
+  if (!addrs)
+    return 0;
+
+  status = efi_call_4 (conf->get_data, conf,
+		      GRUB_EFI_IP6_CONFIG_DATA_TYPE_DNSSERVER,
+		      &data_size, addrs);
+
+  if (status == GRUB_EFI_BUFFER_TOO_SMALL)
+    {
+      grub_free (addrs);
+      addrs  = grub_malloc (data_size);
+      if (!addrs)
+	return 0;
+
+      status = efi_call_4 (conf->get_data,  conf,
+			  GRUB_EFI_IP6_CONFIG_DATA_TYPE_DNSSERVER,
+			  &data_size, addrs);
+    }
+
+  if (status != GRUB_EFI_SUCCESS)
+    {
+      grub_free (addrs);
+      return 0;
+    }
+
+  *num_dns = data_size / sizeof (grub_efi_ipv6_address_t);
+  return addrs;
+}
+
 static struct grub_net_buff *
 grub_efinet_create_dhcp_ack_from_device_path (grub_efi_device_path_t *dp, int *use_ipv6)
 {
@@ -391,6 +512,8 @@ grub_efinet_create_dhcp_ack_from_device_path (grub_efi_device_path_t *dp, int *u
       grub_efi_ipv4_device_path_t *ipv4 = (grub_efi_ipv4_device_path_t *) ldp;
       struct grub_net_bootp_packet *bp;
       grub_uint8_t *ptr;
+      grub_efi_ipv4_address_t *dns;
+      grub_efi_uintn_t num_dns;
 
       bp = (struct grub_net_bootp_packet *) nb->tail;
       err = grub_netbuff_put (nb, sizeof (*bp) + 4);
@@ -452,6 +575,25 @@ grub_efinet_create_dhcp_ack_from_device_path (grub_efi_device_path_t *dp, int *u
       *ptr++ = sizeof ("HTTPClient") - 1;
       grub_memcpy (ptr, "HTTPClient", sizeof ("HTTPClient") - 1);
 
+      dns = grub_dns_server_ip4_address (dp, &num_dns);
+      if (dns)
+	{
+	  grub_efi_uintn_t size_dns = sizeof (*dns) * num_dns;
+
+	  ptr = nb->tail;
+	  err = grub_netbuff_put (nb, size_dns + 2);
+	  if (err)
+	    {
+	      grub_free (ddp);
+	      grub_netbuff_free (nb);
+	      return NULL;
+	    }
+	  *ptr++ = GRUB_NET_BOOTP_DNS;
+	  *ptr++ = size_dns;
+	  grub_memcpy (ptr, dns, size_dns);
+	  grub_free (dns);
+	}
+
       ptr = nb->tail;
       err = grub_netbuff_put (nb, 1);
       if (err)
@@ -484,6 +626,8 @@ grub_efinet_create_dhcp_ack_from_device_path (grub_efi_device_path_t *dp, int *u
       struct grub_net_dhcp6_option *opt;
       struct grub_net_dhcp6_option_iana *iana;
       struct grub_net_dhcp6_option_iaaddr *iaaddr;
+      grub_efi_ipv6_address_t *dns;
+      grub_efi_uintn_t num_dns;
 
       d6p = (struct grub_net_dhcp6_packet *)nb->tail;
       err = grub_netbuff_put (nb, sizeof(*d6p));
@@ -547,6 +691,25 @@ grub_efinet_create_dhcp_ack_from_device_path (grub_efi_device_path_t *dp, int *u
       opt->len = grub_cpu_to_be16 (uri_len);
       grub_memcpy (opt->data, uri_dp->uri, uri_len);
 
+      dns = grub_dns_server_ip6_address (dp, &num_dns);
+      if (dns)
+	{
+	  grub_efi_uintn_t size_dns = sizeof (*dns) * num_dns;
+
+	  opt = (struct grub_net_dhcp6_option *)nb->tail;
+	  err = grub_netbuff_put (nb, sizeof(*opt) + size_dns);
+	  if (err)
+	  {
+	    grub_free (ddp);
+	    grub_netbuff_free (nb);
+	    return NULL;
+	  }
+	  opt->code = grub_cpu_to_be16_compile_time (GRUB_NET_DHCP6_OPTION_DNS_SERVERS);
+	  opt->len = grub_cpu_to_be16 (size_dns);
+	  grub_memcpy (opt->data, dns, size_dns);
+	  grub_free (dns);
+	}
+
       *use_ipv6 = 1;
     }
 
diff --git a/include/grub/efi/api.h b/include/grub/efi/api.h
index eb6bb5085..dd3b07eac 100644
--- a/include/grub/efi/api.h
+++ b/include/grub/efi/api.h
@@ -334,6 +334,16 @@
       { 0x8B, 0x8C, 0xE2, 0x1B, 0x01, 0xAE, 0xF2, 0xB7 } \
   }
 
+#define GRUB_EFI_IP4_CONFIG2_PROTOCOL_GUID \
+  { 0x5b446ed1, 0xe30b, 0x4faa, \
+      { 0x87, 0x1a, 0x36, 0x54, 0xec, 0xa3, 0x60, 0x80 } \
+  }
+
+#define GRUB_EFI_IP6_CONFIG_PROTOCOL_GUID \
+  { 0x937fe521, 0x95ae, 0x4d1a, \
+      { 0x89, 0x29, 0x48, 0xbc, 0xd9, 0x0a, 0xd3, 0x1a } \
+  }
+
 struct grub_efi_sal_system_table
 {
   grub_uint32_t signature;
@@ -1838,6 +1848,72 @@ struct grub_efi_block_io
 };
 typedef struct grub_efi_block_io grub_efi_block_io_t;
 
+enum grub_efi_ip4_config2_data_type {
+  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_INTERFACEINFO,
+  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_POLICY,
+  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_MANUAL_ADDRESS,
+  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_GATEWAY,
+  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_DNSSERVER,
+  GRUB_EFI_IP4_CONFIG2_DATA_TYPE_MAXIMUM
+};
+typedef enum grub_efi_ip4_config2_data_type grub_efi_ip4_config2_data_type_t;
+
+struct grub_efi_ip4_config2_protocol
+{
+  grub_efi_status_t (*set_data) (struct grub_efi_ip4_config2_protocol *this,
+				 grub_efi_ip4_config2_data_type_t data_type,
+				 grub_efi_uintn_t data_size,
+				 void *data);
+
+  grub_efi_status_t (*get_data) (struct grub_efi_ip4_config2_protocol *this,
+				 grub_efi_ip4_config2_data_type_t data_type,
+				 grub_efi_uintn_t *data_size,
+				 void *data);
+
+  grub_efi_status_t (*register_data_notify) (struct grub_efi_ip4_config2_protocol *this,
+					     grub_efi_ip4_config2_data_type_t data_type,
+					     grub_efi_event_t event);
+
+  grub_efi_status_t (*unregister_datanotify) (struct grub_efi_ip4_config2_protocol *this,
+					     grub_efi_ip4_config2_data_type_t data_type,
+					     grub_efi_event_t event);
+};
+typedef struct grub_efi_ip4_config2_protocol grub_efi_ip4_config2_protocol_t;
+
+enum grub_efi_ip6_config_data_type {
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_INTERFACEINFO,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_ALT_INTERFACEID,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_POLICY,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_DUP_ADDR_DETECT_TRANSMITS,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_MANUAL_ADDRESS,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_GATEWAY,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_DNSSERVER,
+  GRUB_EFI_IP6_CONFIG_DATA_TYPE_MAXIMUM
+};
+typedef enum grub_efi_ip6_config_data_type grub_efi_ip6_config_data_type_t;
+
+struct grub_efi_ip6_config_protocol
+{
+  grub_efi_status_t (*set_data) (struct grub_efi_ip6_config_protocol *this,
+				 grub_efi_ip6_config_data_type_t data_type,
+				 grub_efi_uintn_t data_size,
+				 void *data);
+
+  grub_efi_status_t (*get_data) (struct grub_efi_ip6_config_protocol *this,
+				 grub_efi_ip6_config_data_type_t data_type,
+				 grub_efi_uintn_t *data_size,
+				 void *data);
+
+  grub_efi_status_t (*register_data_notify) (struct grub_efi_ip6_config_protocol *this,
+					     grub_efi_ip6_config_data_type_t data_type,
+					     grub_efi_event_t event);
+
+  grub_efi_status_t (*unregister_datanotify) (struct grub_efi_ip6_config_protocol *this,
+					     grub_efi_ip6_config_data_type_t data_type,
+					     grub_efi_event_t event);
+};
+typedef struct grub_efi_ip6_config_protocol grub_efi_ip6_config_protocol_t;
+
 #if (GRUB_TARGET_SIZEOF_VOID_P == 4) || defined (__ia64__) \
   || defined (__aarch64__) || defined (__MINGW64__) || defined (__CYGWIN__)
 
