[PATCH 07/10] efinet: Set DNS server from UEFI protocol

[Michael Chang]

In the URI device path node, any string of characters (i.e., a name),
rather than a network address, can be used to look up resources. This
requires DNS services to resolve the name to an IP address. However,
since the DNS device path requires a later UEFI version and may not
always be available, we use the EFI_IP4_CONFIG2_PROTOCOL and
EFI_IP6_CONFIG_PROTOCOL to obtain the DNS server information.

These two protocols are defined in the following sections of the UEFI
specification:

    27.5 EFI IPv4 Configuration II Protocol
    27.7 EFI IPv6 Configuration Protocol

include/grub/efi/api.h:
Added new structures and protocol UUIDs for EFI_IP4_CONFIG2_PROTOCOL and
EFI_IP6_CONFIG_PROTOCOL.

grub-core/net/drivers/efi/efinet.c:
Uses the EFI_IP4_CONFIG2_PROTOCOL and EFI_IP6_CONFIG_PROTOCOL to obtain
the DNS server addresses for IPv4 and IPv6, respectively. The DNS server
addresses are incorporated into the DHCPACK packet and passed into the
shared DHCP packet processing routines to ensure the network interface
is configured as it was previously.

Signed-off-by: Ken Lin <ken.lin@hpe.com>
Signed-off-by: Robbie Harwood <rharwood@redhat.com>
Signed-off-by: Michael Chang <mchang@suse.com>
---
 grub-core/net/drivers/efi/efinet.c | 163 +++++++++++++++++++++++++++++
 include/grub/efi/api.h             |  77 ++++++++++++++
 2 files changed, 240 insertions(+)

diff --git a/grub-core/net/drivers/efi/efinet.c 
b/grub-core/net/drivers/efi/efinet.c
index 5bafd9fe8..45665c0e9 100644
--- a/grub-core/net/drivers/efi/efinet.c
+++ b/grub-core/net/drivers/efi/efinet.c
@@ -30,6 +30,8 @@ GRUB_MOD_LICENSE ("GPLv3+");
 /* GUID.  */
 static grub_guid_t net_io_guid = GRUB_EFI_SIMPLE_NETWORK_GUID;
 static grub_guid_t pxe_io_guid = GRUB_EFI_PXE_GUID;
+static grub_guid_t ip4_config_guid = GRUB_EFI_IP4_CONFIG2_PROTOCOL_GUID;
+static grub_guid_t ip6_config_guid = GRUB_EFI_IP6_CONFIG_PROTOCOL_GUID;
 
 static grub_err_t
 send_card_buffer (struct grub_net_card *dev,
@@ -343,6 +345,125 @@ grub_efinet_findcards (void)
   grub_free (handles);
 }
 
+static grub_efi_handle_t
+grub_efi_locate_device_path (grub_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 = 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 = 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 = 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 = 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 = 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)
 {
@@ -412,6 +533,8 @@ 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);
@@ -473,6 +596,25 @@ 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)
@@ -505,6 +647,8 @@ 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));
@@ -568,6 +712,25 @@ 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 58a15a9bf..4505c76f7 100644
--- a/include/grub/efi/api.h
+++ b/include/grub/efi/api.h
@@ -367,6 +367,15 @@
 #define GRUB_EFI_RNG_PROTOCOL_GUID \
   { 0x3152bca5, 0xeade, 0x433d, \
     { 0x86, 0x2e, 0xc0, 0x1c, 0xdc, 0x29, 0x1f, 0x44 } \
+
+#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 } \
   }
 
 #define LINUX_EFI_INITRD_MEDIA_GUID  \
@@ -1993,4 +2002,72 @@ struct grub_efi_memory_attribute_protocol
 };
 typedef struct grub_efi_memory_attribute_protocol 
grub_efi_memory_attribute_protocol_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 (__grub_efi_api *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 (__grub_efi_api *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 (__grub_efi_api *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 (__grub_efi_api *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 (__grub_efi_api *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 (__grub_efi_api *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 (__grub_efi_api *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 (__grub_efi_api *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;
+
 #endif /* ! GRUB_EFI_API_HEADER */
-- 
2.47.1