net: dhcp6: Add DHCPv6 (DHCP for IPv6)
Adds DHCPv6 protocol to u-boot.
Allows for address assignement with DHCPv6 4-message exchange
(SOLICIT->ADVERTISE->REQUEST->REPLY). Includes DHCPv6 options
required by RFC 8415. Also adds DHCPv6 options required
for PXE boot.
Possible enhancements:
- Duplicate address detection on DHCPv6 assigned address
- IPv6 address assignement through SLAAC
- Sending/parsing other DHCPv6 options (NTP, DNS, etc...)
Signed-off-by: Sean Edmond <seanedmond@microsoft.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>
diff --git a/net/dhcpv6.h b/net/dhcpv6.h
new file mode 100644
index 0000000..80ca520
--- /dev/null
+++ b/net/dhcpv6.h
@@ -0,0 +1,256 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) Microsoft Corporation
+ * Author: Sean Edmond <seanedmond@microsoft.com>
+ *
+ */
+
+#ifndef __DHCP6_H__
+#define __DHCP6_H__
+
+/* Message types */
+#define DHCP6_MSG_SOLICIT 1
+#define DHCP6_MSG_ADVERTISE 2
+#define DHCP6_MSG_REQUEST 3
+#define DHCP6_MSG_REPLY 7
+
+/* Option Codes */
+#define DHCP6_OPTION_CLIENTID 1
+#define DHCP6_OPTION_SERVERID 2
+#define DHCP6_OPTION_IA_NA 3
+#define DHCP6_OPTION_IA_TA 4
+#define DHCP6_OPTION_IAADDR 5
+#define DHCP6_OPTION_ORO 6
+#define DHCP6_OPTION_PREFERENCE 7
+#define DHCP6_OPTION_ELAPSED_TIME 8
+#define DHCP6_OPTION_STATUS_CODE 13
+#define DHCP6_OPTION_OPT_BOOTFILE_URL 59
+#define DHCP6_OPTION_OPT_BOOTFILE_PARAM 60
+#define DHCP6_OPTION_SOL_MAX_RT 82
+#define DHCP6_OPTION_CLIENT_ARCH_TYPE 61
+#define DHCP6_OPTION_VENDOR_CLASS 16
+#define DHCP6_OPTION_NII 62
+
+/* DUID */
+#define DUID_TYPE_LL 3
+#define DUID_HW_TYPE_ENET 1
+#define DUID_LL_SIZE (sizeof(struct dhcp6_option_duid_ll) + ETH_ALEN)
+#define DUID_MAX_SIZE DUID_LL_SIZE /* only supports DUID-LL currently */
+
+/* vendor-class-data to send in vendor clas option */
+#define DHCP6_VCI_STRING "U-boot"
+
+#define DHCP6_MULTICAST_ADDR "ff02::1:2" /* DHCP multicast address */
+
+/* DHCP6 States supported */
+enum dhcp6_state {
+ DHCP6_INIT,
+ DHCP6_SOLICIT,
+ DHCP6_REQUEST,
+ DHCP6_DONE,
+ DHCP6_FAIL,
+};
+
+/* DHCP6 Status codes */
+enum dhcp6_status {
+ DHCP6_SUCCESS = 0,
+ DHCP6_UNSPEC_FAIL = 1,
+ DHCP6_NO_ADDRS_AVAIL = 2,
+ DHCP6_NO_BINDING = 3,
+ DHCP6_NOT_ON_LINK = 4,
+ DHCP6_USE_MULTICAST = 5,
+ DHCP6_NO_PREFIX_AVAIL = 6,
+};
+
+/* DHCP6 message header format */
+struct dhcp6_hdr {
+ unsigned int msg_type : 8; /* message type */
+ unsigned int trans_id : 24; /* transaction ID */
+} __packed;
+
+/* DHCP6 option header format */
+struct dhcp6_option_hdr {
+ __be16 option_id; /* option id */
+ __be16 option_len; /* Option length */
+ u8 option_data[0]; /* Option data */
+} __packed;
+
+/* DHCP6_OPTION_CLIENTID option (DUID-LL) */
+struct dhcp6_option_duid_ll {
+ __be16 duid_type;
+ __be16 hw_type;
+ u8 ll_addr[0];
+} __packed;
+
+/* DHCP6_OPTION_ELAPSED_TIME option */
+struct dhcp6_option_elapsed_time {
+ __be16 elapsed_time;
+} __packed;
+
+/* DHCP6_OPTION_IA_TA option */
+struct dhcp6_option_ia_ta {
+ __be32 iaid;
+ u8 ia_ta_options[0];
+} __packed;
+
+/* DHCP6_OPTION_IA_NA option */
+struct dhcp6_option_ia_na {
+ __be32 iaid;
+ __be32 t1;
+ __be32 t2;
+ u8 ia_na_options[0];
+} __packed;
+
+/* OPTION_ORO option */
+struct dhcp6_option_oro {
+ __be16 req_option_code[0];
+} __packed;
+
+/* DHCP6_OPTION_CLIENT_ARCH_TYPE option */
+struct dhcp6_option_client_arch {
+ __be16 arch_type[0];
+} __packed;
+
+/* vendor-class-data inside OPTION_VENDOR_CLASS option */
+struct vendor_class_data {
+ __be16 vendor_class_len;
+ u8 opaque_data[0];
+} __packed;
+
+/* DHCP6_OPTION_VENDOR_CLASS option */
+struct dhcp6_option_vendor_class {
+ __be32 enterprise_number;
+ struct vendor_class_data vendor_class_data[0];
+} __packed;
+
+/**
+ * struct dhcp6_rx_pkt_status - Structure that holds status
+ * from a received message
+ * @client_id_match: Client ID was found and matches DUID sent
+ * @server_id_found: Server ID was found in the message
+ * @server_uid_ptr: Pointer to received server ID
+ * @server_uid_size: Size of received server ID
+ * @ia_addr_found: IA addr option was found in received message
+ * @ia_addr_ipv6: The IPv6 address received in IA
+ * @ia_status_code: Status code received in the IA
+ * @status_code: Top-level status code received
+ * @preference: Preference code received
+ */
+struct dhcp6_rx_pkt_status {
+ bool client_id_match;
+ bool server_id_found;
+ uchar *server_uid_ptr;
+ u16 server_uid_size;
+ bool ia_addr_found;
+ struct in6_addr ia_addr_ipv6;
+ enum dhcp6_status ia_status_code;
+ enum dhcp6_status status_code;
+ u8 preference;
+};
+
+/**
+ * struct dhcp6_server_uid - Structure that holds the server UID
+ * received from an ADVERTISE and saved
+ * given the server selection criteria.
+ * @uid_ptr: Dynamically allocated and copied server UID
+ * @uid_size: Size of the server UID in uid_ptr (in bytes)
+ * @preference: Preference code associated with this server UID
+ */
+struct dhcp6_server_uid {
+ uchar *uid_ptr;
+ u16 uid_size;
+ u8 preference;
+};
+
+/**
+ * struct dhcp6_sm_params - Structure that holds DHCP6
+ * state machine parameters
+ * @curr_state: current DHCP6 state
+ * @next_state: next DHCP6 state
+ * @dhcp6_start_ms: timestamp DHCP6 start
+ * @dhcp6_retry_start_ms: timestamp of current TX message start
+ * @dhcp6_retry_ms: timestamp of last retransmission
+ * @retry_cnt: retry count
+ * @trans_id: transaction ID
+ * @ia_id: transmitted IA ID
+ * @irt_ms: Initial retransmission time (in ms)
+ * @mrt_ms: Maximum retransmission time (in ms)
+ * @mrc: Maximum retransmission count
+ * @mrd_ms: Maximum retransmission duration (in ms)
+ * @rt_ms: retransmission timeout (is ms)
+ * @rt_prev_ms: previous retransmission timeout
+ * @rx_status: Status from received message
+ * @server_uid: Saved Server UID for selected server
+ * @duid: pointer to transmitted Client DUID
+ */
+struct dhcp6_sm_params {
+ enum dhcp6_state curr_state;
+ enum dhcp6_state next_state;
+ ulong dhcp6_start_ms;
+ ulong dhcp6_retry_start_ms;
+ ulong dhcp6_retry_ms;
+ u32 retry_cnt;
+ u32 trans_id;
+ u32 ia_id;
+ int irt_ms;
+ int mrt_ms;
+ int mrc;
+ int mrd_ms;
+ int rt_ms;
+ int rt_prev_ms;
+ struct dhcp6_rx_pkt_status rx_status;
+ struct dhcp6_server_uid server_uid;
+ char duid[DUID_MAX_SIZE];
+};
+
+/* Starts a DHCPv6 4-message exchange as a DHCPv6 client. On successful exchange,
+ * the DHCPv6 state machine will transition from internal states:
+ * DHCP6_INIT->DHCP6_SOLICIT->DHCP6_REQUEST->DHCP6_DONE
+ *
+ * Transmitted SOLICIT and REQUEST packets will set/request the minimum required
+ * DHCPv6 options to PXE boot.
+ *
+ * After a successful exchange, the DHCPv6 assigned address will be set in net_ip6
+ *
+ * Additionally, the following will be set after receiving these options:
+ * DHCP6_OPTION_OPT_BOOTFILE_URL (option 59) -> net_server_ip6, net_boot_file_name
+ * DHCP6_OPTION_OPT_BOOTFILE_PARAM (option 60) - > pxelinux_configfile
+ *
+ * Illustration of a 4-message exchange with 2 servers (copied from
+ * https://www.rfc-editor.org/rfc/rfc8415):
+ *
+ * Server Server
+ * (not selected) Client (selected)
+ *
+ * v v v
+ * | | |
+ * | Begins initialization |
+ * | | |
+ * start of | _____________/|\_____________ |
+ * 4-message |/ Solicit | Solicit \|
+ * exchange | | |
+ * Determines | Determines
+ * configuration | configuration
+ * | | |
+ * |\ | ____________/|
+ * | \________ | /Advertise |
+ * | Advertise\ |/ |
+ * | \ | |
+ * | Collects Advertises |
+ * | \ | |
+ * | Selects configuration |
+ * | | |
+ * | _____________/|\_____________ |
+ * |/ Request | Request \|
+ * | | |
+ * | | Commits configuration
+ * | | |
+ * end of | | _____________/|
+ * 4-message | |/ Reply |
+ * exchange | | |
+ * | Initialization complete |
+ * | | |
+ */
+void dhcp6_start(void);
+
+#endif /* __DHCP6_H__ */