[PATCH v2 1/3] net: dhcp6: Add DHCPv6 (DHCP for IPv6)

seanedmond
2023-04-07T06:56:58Z

From: Sean Edmond <seanedmond@microsoft.com>

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>
---
include/net.h | 8 +-
net/Makefile | 1 +
net/dhcpv6.c | 735 ++++++++++++++++++++++++++++++++++++++++++++++++++
net/dhcpv6.h | 212 +++++++++++++++
net/net.c | 12 +
5 files changed, 966 insertions(+), 2 deletions(-)
create mode 100644 net/dhcpv6.c
create mode 100644 net/dhcpv6.h

diff --git a/include/net.h b/include/net.h
index 399af5e064..cac818e292 100644
--- a/include/net.h
+++ b/include/net.h
@@ -484,6 +484,10 @@ extern char net_hostname[32]; /* Our hostname */
#ifdef CONFIG_NET
extern char net_root_path[CONFIG_BOOTP_MAX_ROOT_PATH_LEN]; /* Our root path */
#endif
+#if defined(CONFIG_DHCP6_PXE_DHCP_OPTION)
+/* Indicates whether the pxe path prefix / config file was specified in dhcp option */
+extern char *pxelinux_configfile;
+#endif
/** END OF BOOTP EXTENTIONS **/
extern u8 net_ethaddr[ARP_HLEN]; /* Our ethernet address */
extern u8 net_server_ethaddr[ARP_HLEN]; /* Boot server enet address */
@@ -504,8 +508,8 @@ extern ushort net_native_vlan; /* Our Native VLAN */
extern int net_restart_wrap; /* Tried all network devices */

enum proto_t {
- BOOTP, RARP, ARP, TFTPGET, DHCP, PING, PING6, DNS, NFS, CDP, NETCONS,
- SNTP, TFTPSRV, TFTPPUT, LINKLOCAL, FASTBOOT, WOL, UDP, NCSI, WGET
+ BOOTP, RARP, ARP, TFTPGET, DHCP, DHCP6, PING, PING6, DNS, NFS, CDP,
+ NETCONS, SNTP, TFTPSRV, TFTPPUT, LINKLOCAL, FASTBOOT, WOL, UDP, NCSI, WGET
};

extern char net_boot_file_name[1024];/* Boot File name */
diff --git a/net/Makefile b/net/Makefile
index bea000b206..5968110170 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_IPV6) += net6.o
obj-$(CONFIG_CMD_NFS) += nfs.o
obj-$(CONFIG_CMD_PING) += ping.o
obj-$(CONFIG_CMD_PING6) += ping6.o
+obj-$(CONFIG_CMD_DHCP6) += dhcpv6.o
obj-$(CONFIG_CMD_PCAP) += pcap.o
obj-$(CONFIG_CMD_RARP) += rarp.o
obj-$(CONFIG_CMD_SNTP) += sntp.o
diff --git a/net/dhcpv6.c b/net/dhcpv6.c
new file mode 100644
index 0000000000..9204909c1f
--- /dev/null
+++ b/net/dhcpv6.c
@@ -0,0 +1,735 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) Microsoft Corporation
+ * Author: Sean Edmond <seanedmond@microsoft.com>
+ *
+ */
+
+/* Simple DHCP6 network layer implementation. */
+
+#include <common.h>
+#include <bootstage.h>
+#include <command.h>
+#include <env.h>
+#include <efi_loader.h>
+#include <log.h>
+#include <net.h>
+#include <rand.h>
+#include <uuid.h>
+#include <linux/delay.h>
+#include <net/tftp.h>
+#include "dhcpv6.h"
+#include <net6.h>
+#include <malloc.h>
+#include "net_rand.h"
+
+#define PORT_DHCP6_S 547 /* DHCP6 server UDP port */
+#define PORT_DHCP6_C 546 /* DHCP6 client UDP port */
+
+/* default timeout parameters (in ms) */
+#define SOL_MAX_DELAY_MS 1000
+#define SOL_TIMEOUT_MS 1000
+#define SOL_MAX_RT_MS 3600000
+#define REQ_TIMEOUT_MS 1000
+#define REQ_MAX_RT_MS 30000
+#define REQ_MAX_RC 10
+#define MAX_WAIT_TIME_MS 60000
+
+/* global variable to track any updates from DHCP6 server */
+int updated_sol_max_rt_ms = SOL_MAX_RT_MS;
+
+static void dhcp6_timeout_handler(void);
+static void dhcp6_state_machine(bool timeout, uchar *rx_pkt, unsigned int len);
+static void dhcp6_parse_options(uchar *rx_pkt, unsigned int len);
+
+struct dhcp6_sm_params sm_params;
+
+/*
+ * Handle DHCP received packets (set as UDP handler)
+ */
+static void dhcp6_handler(uchar *pkt, unsigned int dest, struct in_addr sip,
+ unsigned int src, unsigned int len)
+{
+ /* return if ports don't match DHCPv6 ports */
+ if (dest != PORT_DHCP6_C || src != PORT_DHCP6_S)
+ return;
+
+ dhcp6_state_machine(false, pkt, len);
+}
+
+/**
+ * dhcp6_add_option() - Adds DHCP6 option to a packet
+ * @option_id: The option ID to add (See DHCP6_OPTION_* definitions)
+ * @pkt: A pointer to the current write location of the TX packet
+ *
+ * Return: The number of bytes written into "*pkt"
+ */
+static int dhcp6_add_option(int option_id, uchar *pkt)
+{
+ struct dhcp6_option_duid_ll *duid_opt;
+ struct dhcp6_option_elapsed_time *elapsed_time_opt;
+ struct dhcp6_option_ia_ta *ia_ta_opt;
+ struct dhcp6_option_ia_na *ia_na_opt;
+ struct dhcp6_option_oro *oro_opt;
+ struct dhcp6_option_client_arch *client_arch_opt;
+ struct dhcp6_option_vendor_class *vendor_class_opt;
+ int opt_len;
+ long elapsed_time;
+ size_t vci_strlen;
+ int num_oro = 0;
+ int num_client_arch = 0;
+ int num_vc_data = 0;
+ struct dhcp6_option_hdr *dhcp_option = (struct dhcp6_option_hdr *)pkt;
+ uchar *dhcp_option_start = pkt + sizeof(struct dhcp6_option_hdr);
+
+ dhcp_option->option_id = htons(option_id);
+
+ switch (option_id) {
+ case DHCP6_OPTION_CLIENTID:
+ /* Only support for DUID-LL in Client ID option for now */
+ duid_opt = (struct dhcp6_option_duid_ll *)dhcp_option_start;
+ duid_opt->duid_type = htons(DUID_TYPE_LL);
+ duid_opt->hw_type = htons(DUID_HW_TYPE_ENET);
+ memcpy(duid_opt->ll_addr, net_ethaddr, ETH_ALEN);
+ opt_len = sizeof(struct dhcp6_option_duid_ll) + ETH_ALEN;
+
+ /* Save DUID for comparison later */
+ memcpy(sm_params.duid, duid_opt, opt_len);
+ break;
+ case DHCP6_OPTION_ELAPSED_TIME:
+ /* calculate elapsed time in 1/100th of a second */
+ elapsed_time = (sm_params.dhcp6_retry_ms -
+ sm_params.dhcp6_start_ms) / 10;
+ if (elapsed_time > 0xFFFF)
+ elapsed_time = 0xFFFF;
+
+ elapsed_time_opt = (struct dhcp6_option_elapsed_time *)dhcp_option_start;
+ elapsed_time_opt->elapsed_time = htons(elapsed_time);
+
+ opt_len = sizeof(struct dhcp6_option_elapsed_time);
+ break;
+ case DHCP6_OPTION_IA_TA:
+ ia_ta_opt = (struct dhcp6_option_ia_ta *)dhcp_option_start;
+ ia_ta_opt->iaid = htonl(sm_params.ia_id);
+
+ opt_len = sizeof(struct dhcp6_option_ia_ta);
+ break;
+ case DHCP6_OPTION_IA_NA:
+ ia_na_opt = (struct dhcp6_option_ia_na *)dhcp_option_start;
+ ia_na_opt->iaid = htonl(sm_params.ia_id);
+ /* In a message sent by a client to a server,
+ * the T1 and T2 fields SHOULD be set to 0
+ */
+ ia_na_opt->t1 = 0;
+ ia_na_opt->t2 = 0;
+
+ opt_len = sizeof(struct dhcp6_option_ia_na);
+ break;
+ case DHCP6_OPTION_ORO:
+ oro_opt = (struct dhcp6_option_oro *)dhcp_option_start;
+ oro_opt->req_option_code[num_oro++] = htons(DHCP6_OPTION_OPT_BOOTFILE_URL);
+ oro_opt->req_option_code[num_oro++] = htons(DHCP6_OPTION_SOL_MAX_RT);
+ if (IS_ENABLED(CONFIG_DHCP6_PXE_DHCP_OPTION)) {
+ oro_opt->req_option_code[num_oro++] =
+ htons(DHCP6_OPTION_OPT_BOOTFILE_PARAM);
+ }
+
+ opt_len = sizeof(__be16) * num_oro;
+ break;
+ case DHCP6_OPTION_CLIENT_ARCH_TYPE:
+ client_arch_opt = (struct dhcp6_option_client_arch *)dhcp_option_start;
+ client_arch_opt->arch_type[num_client_arch++] = htons(CONFIG_DHCP6_PXE_CLIENTARCH);
+
+ opt_len = sizeof(__be16) * num_client_arch;
+ break;
+ case DHCP6_OPTION_VENDOR_CLASS:
+ vendor_class_opt = (struct dhcp6_option_vendor_class *)dhcp_option_start;
+ vendor_class_opt->enterprise_number = htonl(CONFIG_DHCP6_ENTERPRISE_ID);
+
+ vci_strlen = strlen(DHCP6_VCI_STRING);
+ vendor_class_opt->vendor_class_data[num_vc_data].vendor_class_len =
+ htons(vci_strlen);
+ memcpy(vendor_class_opt->vendor_class_data[num_vc_data].opaque_data,
+ DHCP6_VCI_STRING, vci_strlen);
+ num_vc_data++;
+
+ opt_len = sizeof(struct dhcp6_option_vendor_class) +
+ sizeof(struct vendor_class_data) * num_vc_data +
+ vci_strlen;
+ break;
+ case DHCP6_OPTION_NII:
+ dhcp_option_start[0] = 1;
+ dhcp_option_start[1] = 0;
+ dhcp_option_start[2] = 0;
+
+ opt_len = 3;
+ break;
+ default:
+ printf("***Warning unknown DHCP6 option %d. Not adding to message\n", option_id);
+ return 0;
+ }
+ dhcp_option->option_len = htons(opt_len);
+
+ return opt_len + sizeof(struct dhcp6_option_hdr);
+}
+
+/**
+ * dhcp6_send_solicit_packet() - Send a SOLICIT packet
+ *
+ * Implements RFC 8415:
+ * - 16.2. Solicit Message
+ * - 18.2.1. Creation and Transmission of Solicit Messages
+ *
+ * Adds DHCP6 header and DHCP6 options. Sends the UDP packet
+ * and sets the UDP handler.
+ */
+static void dhcp6_send_solicit_packet(void)
+{
+ struct in6_addr dhcp_bcast_ip6;
+ int len = 0;
+ uchar *pkt;
+ uchar *dhcp_pkt_start_ptr;
+ struct dhcp6_hdr *dhcp_hdr;
+
+ pkt = net_tx_packet + net_eth_hdr_size() + IP6_HDR_SIZE + UDP_HDR_SIZE;
+ dhcp_pkt_start_ptr = pkt;
+
+ /* Add the DHCP6 header */
+ dhcp_hdr = (struct dhcp6_hdr *)pkt;
+ dhcp_hdr->msg_type = DHCP6_MSG_SOLICIT;
+ dhcp_hdr->trans_id = htons(sm_params.trans_id);
+ pkt += sizeof(struct dhcp6_hdr);
+
+ /* Add the options */
+ pkt += dhcp6_add_option(DHCP6_OPTION_CLIENTID, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_ELAPSED_TIME, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_IA_NA, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_ORO, pkt);
+ if (CONFIG_DHCP6_PXE_CLIENTARCH != 0xFF)
+ pkt += dhcp6_add_option(DHCP6_OPTION_CLIENT_ARCH_TYPE, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_VENDOR_CLASS, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_NII, pkt);
+
+ /* calculate packet length */
+ len = pkt - dhcp_pkt_start_ptr;
+
+ /* send UDP packet to DHCP6 multicast address */
+ string_to_ip6(DHCP6_MULTICAST_ADDR, sizeof(DHCP6_MULTICAST_ADDR), &dhcp_bcast_ip6);
+ net_set_udp_handler(dhcp6_handler);
+ net_send_udp_packet6((uchar *)net_bcast_ethaddr, &dhcp_bcast_ip6,
+ PORT_DHCP6_S, PORT_DHCP6_C, len);
+}
+
+/**
+ * dhcp6_send_request_packet() - Send a REQUEST packet
+ *
+ * * Implements RFC 8415:
+ * - 16.4. Request Message
+ * - 18.2.2. Creation and Transmission of Request Messages
+ *
+ * Adds DHCP6 header and DHCP6 options. Sends the UDP packet
+ * and sets the UDP handler.
+ */
+static void dhcp6_send_request_packet(void)
+{
+ struct in6_addr dhcp_bcast_ip6;
+ int len = 0;
+ uchar *pkt;
+ uchar *dhcp_pkt_start_ptr;
+ struct dhcp6_hdr *dhcp_hdr;
+
+ pkt = net_tx_packet + net_eth_hdr_size() + IP6_HDR_SIZE + UDP_HDR_SIZE;
+ dhcp_pkt_start_ptr = pkt;
+
+ /* Add the DHCP6 header */
+ dhcp_hdr = (struct dhcp6_hdr *)pkt;
+ dhcp_hdr->msg_type = DHCP6_MSG_REQUEST;
+ dhcp_hdr->trans_id = htons(sm_params.trans_id);
+ pkt += sizeof(struct dhcp6_hdr);
+
+ /* add the options */
+ pkt += dhcp6_add_option(DHCP6_OPTION_CLIENTID, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_ELAPSED_TIME, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_IA_NA, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_ORO, pkt);
+ /* copy received IA_TA/IA_NA into the REQUEST packet */
+ if (sm_params.server_uid.uid_ptr) {
+ memcpy(pkt, sm_params.server_uid.uid_ptr, sm_params.server_uid.uid_size);
+ pkt += sm_params.server_uid.uid_size;
+ }
+ if (CONFIG_DHCP6_PXE_CLIENTARCH != 0xFF)
+ pkt += dhcp6_add_option(DHCP6_OPTION_CLIENT_ARCH_TYPE, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_VENDOR_CLASS, pkt);
+ pkt += dhcp6_add_option(DHCP6_OPTION_NII, pkt);
+
+ /* calculate packet length */
+ len = pkt - dhcp_pkt_start_ptr;
+
+ /* send UDP packet to DHCP6 multicast address */
+ string_to_ip6(DHCP6_MULTICAST_ADDR, strlen(DHCP6_MULTICAST_ADDR), &dhcp_bcast_ip6);
+ net_set_udp_handler(dhcp6_handler);
+ net_send_udp_packet6((uchar *)net_bcast_ethaddr, &dhcp_bcast_ip6,
+ PORT_DHCP6_S, PORT_DHCP6_C, len);
+}
+
+static void dhcp6_parse_ia_options(struct dhcp6_option_hdr *ia_ptr, uchar *ia_option_ptr)
+{
+ struct dhcp6_option_hdr *ia_option_hdr;
+
+ ia_option_hdr = (struct dhcp6_option_hdr *)ia_option_ptr;
+
+ /* Search for options encapsulated in IA_NA/IA_TA (DHCP6_OPTION_IAADDR
+ * or DHCP6_OPTION_STATUS_CODE)
+ */
+ while (ia_option_ptr < ((uchar *)ia_ptr + ntohs(ia_ptr->option_len))) {
+ switch (ntohs(ia_option_hdr->option_id)) {
+ case DHCP6_OPTION_IAADDR:
+ sm_params.rx_status.ia_addr_found = true;
+ net_copy_ip6(&sm_params.rx_status.ia_addr_ipv6,
+ (ia_option_ptr + sizeof(struct dhcp6_hdr)));
+ debug("DHCP6_OPTION_IAADDR FOUND\n");
+ break;
+ case DHCP6_OPTION_STATUS_CODE:
+ sm_params.rx_status.ia_status_code =
+ ntohs(*((u16 *)(ia_option_ptr + sizeof(struct dhcp6_hdr))));
+ printf("ERROR : IA STATUS %d\n", sm_params.rx_status.ia_status_code);
+ break;
+ default:
+ debug("Unknown Option in IA, skipping\n");
+ break;
+ }
+
+ ia_option_ptr += ntohs(((struct dhcp6_option_hdr *)ia_option_ptr)->option_len);
+ }
+}
+
+/**
+ * dhcp6_parse_options() - Parse the DHCP6 options
+ *
+ * @rx_pkt: pointer to beginning of received DHCP6 packet
+ * @len: Total length of the DHCP6 packet
+ *
+ * Parses the DHCP options from a received DHCP packet. Perform error checking
+ * on the options received. Any relevant status is available in:
+ * "sm_params.rx_status"
+ *
+ */
+static void dhcp6_parse_options(uchar *rx_pkt, unsigned int len)
+{
+ uchar *option_ptr;
+ int sol_max_rt_sec, option_len;
+ char *s, *e;
+ struct dhcp6_option_hdr *option_hdr;
+
+ memset(&sm_params.rx_status, 0, sizeof(struct dhcp6_rx_pkt_status));
+
+ option_hdr = (struct dhcp6_option_hdr *)(rx_pkt + sizeof(struct dhcp6_hdr));
+ /* check that required options exist */
+ while (option_hdr < (struct dhcp6_option_hdr *)(rx_pkt + len)) {
+ option_ptr = ((uchar *)option_hdr) + sizeof(struct dhcp6_hdr);
+ option_len = ntohs(option_hdr->option_len);
+
+ switch (ntohs(option_hdr->option_id)) {
+ case DHCP6_OPTION_CLIENTID:
+ if (memcmp(option_ptr, sm_params.duid, option_len)
+ != 0) {
+ debug("CLIENT ID DOESN'T MATCH\n");
+ } else {
+ debug("CLIENT ID FOUND and MATCHES\n");
+ sm_params.rx_status.client_id_match = true;
+ }
+ break;
+ case DHCP6_OPTION_SERVERID:
+ sm_params.rx_status.server_id_found = true;
+ sm_params.rx_status.server_uid_ptr = (uchar *)option_hdr;
+ sm_params.rx_status.server_uid_size = option_len +
+ sizeof(struct dhcp6_option_hdr);
+ debug("SERVER ID FOUND\n");
+ break;
+ case DHCP6_OPTION_IA_TA:
+ case DHCP6_OPTION_IA_NA:
+ /* check the IA_ID */
+ if (*((u32 *)option_ptr) != htonl(sm_params.ia_id)) {
+ debug("IA_ID mismatch 0x%08x 0x%08x\n",
+ *((u32 *)option_ptr), htonl(sm_params.ia_id));
+ break;
+ }
+
+ if (ntohs(option_hdr->option_id) == DHCP6_OPTION_IA_NA) {
+ /* skip past IA_ID/T1/T2 */
+ option_ptr += 3 * sizeof(u32);
+ } else if (ntohs(option_hdr->option_id) == DHCP6_OPTION_IA_TA) {
+ /* skip past IA_ID */
+ option_ptr += sizeof(u32);
+ }
+ /* parse the IA_NA/IA_TA encapsulated options */
+ dhcp6_parse_ia_options(option_hdr, option_ptr);
+ break;
+ case DHCP6_OPTION_STATUS_CODE:
+ debug("DHCP6_OPTION_STATUS_CODE FOUND\n");
+ sm_params.rx_status.status_code = ntohs(*((u16 *)option_ptr));
+ debug("DHCP6 top-level status code %d\n", sm_params.rx_status.status_code);
+ debug("DHCP6 status message: %.*s\n", len, option_ptr + 2);
+ break;
+ case DHCP6_OPTION_SOL_MAX_RT:
+ debug("DHCP6_OPTION_SOL_MAX_RT FOUND\n");
+ sol_max_rt_sec = ntohl(*((u32 *)option_ptr));
+
+ /* A DHCP client MUST ignore any SOL_MAX_RT option values that are less
+ * than 60 or more than 86400
+ */
+ if (sol_max_rt_sec >= 60 && sol_max_rt_sec <= 86400) {
+ updated_sol_max_rt_ms = sol_max_rt_sec * 1000;
+ if (sm_params.curr_state == DHCP6_SOLICIT)
+ sm_params.mrt_ms = updated_sol_max_rt_ms;
+ }
+ break;
+ case DHCP6_OPTION_OPT_BOOTFILE_URL:
+ debug("DHCP6_OPTION_OPT_BOOTFILE_URL FOUND\n");
+ copy_filename(net_boot_file_name, option_ptr, option_len + 1);
+ debug("net_boot_file_name: %s\n", net_boot_file_name);
+
+ /* copy server_ip6 (required for PXE) */
+ s = strchr(net_boot_file_name, '[');
+ e = strchr(net_boot_file_name, ']');
+ if (s && e && e > s)
+ string_to_ip6(s + 1, e - s - 1, &net_server_ip6);
+ break;
+#if IS_ENABLED(CONFIG_DHCP6_PXE_DHCP_OPTION)
+ case DHCP6_OPTION_OPT_BOOTFILE_PARAM:
+ debug("DHCP6_OPTION_OPT_BOOTFILE_PARAM FOUND\n");
+
+ if (pxelinux_configfile)
+ free(pxelinux_configfile);
+
+ pxelinux_configfile = (char *)malloc((option_len + 1) * sizeof(char));
+ if (pxelinux_configfile) {
+ memcpy(pxelinux_configfile, option_ptr, option_len);
+ pxelinux_configfile[option_len] = '\0';
+ }
+
+ debug("PXE CONFIG FILE %s\n", pxelinux_configfile);
+ break;
+#endif
+ case DHCP6_OPTION_PREFERENCE:
+ debug("DHCP6_OPTION_PREFERENCE FOUND\n");
+ sm_params.rx_status.preference = *option_ptr;
+ break;
+ default:
+ debug("Unknown Option ID: %d, skipping parsing\n",
+ ntohs(option_hdr->option_id));
+ break;
+ }
+ /* Increment to next option header */
+ option_hdr = (struct dhcp6_option_hdr *)(((uchar *)option_hdr) +
+ sizeof(struct dhcp6_option_hdr) + option_len);
+ }
+}
+
+/**
+ * dhcp6_check_advertise_packet() - Perform error checking on an expected
+ * ADVERTISE packet.
+ *
+ * @rx_pkt: pointer to beginning of received DHCP6 packet
+ * @len: Total length of the DHCP6 packet
+ *
+ * Implements RFC 8415:
+ * - 16.3. Advertise Message
+ * - 18.2.10. Receipt of Reply Messages
+ *
+ * Return : 0 : ADVERTISE packet was received with no errors.
+ * State machine can progress
+ * 1 : - packet received is not an ADVERTISE packet
+ * - there were errors in the packet received,
+ * - this is the first SOLICIT packet, but
+ * received preference is not 255, so we have
+ * to wait for more server responses.
+ */
+static int dhcp6_check_advertise_packet(uchar *rx_pkt, unsigned int len)
+{
+ u16 rx_uid_size;
+ struct dhcp6_hdr *dhcp6_hdr = (struct dhcp6_hdr *)rx_pkt;
+
+ /* Ignore message if msg-type != advertise */
+ if (dhcp6_hdr->msg_type != DHCP6_MSG_ADVERTISE)
+ return 1;
+ /* Ignore message if transaction ID doesn't match */
+ if (dhcp6_hdr->trans_id != htons(sm_params.trans_id))
+ return 1;
+
+ dhcp6_parse_options(rx_pkt, len);
+
+ /* Ignore advertise if any of these conditions met */
+ if (!sm_params.rx_status.server_id_found ||
+ !sm_params.rx_status.client_id_match ||
+ sm_params.rx_status.status_code != DHCP6_SUCCESS) {
+ return 1;
+ }
+
+ if (sm_params.rx_status.server_id_found) {
+ /* if no server UID has been received yet, or if the server UID
+ * received has a higher preference value than the currently saved
+ * server UID, save the new server UID and preference
+ */
+ if (!sm_params.server_uid.uid_ptr ||
+ (sm_params.server_uid.uid_ptr &&
+ sm_params.server_uid.preference < sm_params.rx_status.preference)) {
+ rx_uid_size = sm_params.rx_status.server_uid_size;
+ if (sm_params.server_uid.uid_ptr)
+ free(sm_params.server_uid.uid_ptr);
+ sm_params.server_uid.uid_ptr = malloc(rx_uid_size * sizeof(uchar));
+ if (sm_params.server_uid.uid_ptr)
+ memcpy(sm_params.server_uid.uid_ptr,
+ sm_params.rx_status.server_uid_ptr, rx_uid_size);
+
+ sm_params.server_uid.uid_size = rx_uid_size;
+ sm_params.server_uid.preference = sm_params.rx_status.preference;
+ }
+
+ /* If the first SOLICIT and preference code is 255, use right away.
+ * Otherwise, wait for the first SOLICIT period for more
+ * DHCP6 servers to respond.
+ */
+ if (sm_params.retry_cnt == 1 &&
+ sm_params.server_uid.preference != 255) {
+ debug("valid ADVERTISE, waiting for first SOLICIT period\n");
+ return 1;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * dhcp6_check_reply_packet() - Perform error checking on an expected
+ * REPLY packet.
+ *
+ * @rx_pkt: pointer to beginning of received DHCP6 packet
+ * @len: Total length of the DHCP6 packet
+ *
+ * Implements RFC 8415:
+ * - 16.10. Reply Message
+ * - 18.2.10. Receipt of Reply Messages
+ *
+ * Return : 0 - REPLY packet was received with no errors
+ * 1 - packet received is not an REPLY packet,
+ * or there were errors in the packet received
+ */
+static int dhcp6_check_reply_packet(uchar *rx_pkt, unsigned int len)
+{
+ struct dhcp6_hdr *dhcp6_hdr = (struct dhcp6_hdr *)rx_pkt;
+
+ /* Ignore message if msg-type != reply */
+ if (dhcp6_hdr->msg_type != DHCP6_MSG_REPLY)
+ return 1;
+ /* check that transaction ID matches */
+ if (dhcp6_hdr->trans_id != htons(sm_params.trans_id))
+ return 1;
+
+ dhcp6_parse_options(rx_pkt, len);
+
+ /* if no addresses found, restart DHCP */
+ if (!sm_params.rx_status.ia_addr_found ||
+ sm_params.rx_status.ia_status_code == DHCP6_NO_ADDRS_AVAIL ||
+ sm_params.rx_status.status_code == DHCP6_NOT_ON_LINK) {
+ /* restart DHCP */
+ debug("No address found in reply. Restarting DHCP\n");
+ dhcp6_start();
+ }
+
+ /* ignore reply if any of these conditions met */
+ if (!sm_params.rx_status.server_id_found ||
+ !sm_params.rx_status.client_id_match ||
+ sm_params.rx_status.status_code == DHCP6_UNSPEC_FAIL) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/**
+ * dhcp6_state_machine() - DHCP6 state machine
+ *
+ * @timeout: TRUE : timeout waiting for response from
+ * DHCP6 server
+ * FALSE : init or received response from DHCP6 server
+ * @rx_pkt: Pointer to the beginning of received DHCP6 packet.
+ * Will be NULL if called as part of init
+ * or timeout==TRUE
+ * @len: Total length of the DHCP6 packet if rx_pkt != NULL
+ *
+ * Implements RFC 8415:
+ * - 5.2. Client/Server Exchanges Involving Four Messages
+ * - 15. Reliability of Client-Initiated Message Exchanges
+ *
+ * Handles:
+ * - transmission of SOLICIT and REQUEST packets
+ * - retransmission of SOLICIT and REQUEST packets if no
+ * response is received within the timeout window
+ * - checking received ADVERTISE and REPLY packets to
+ * assess if the DHCP state machine can progress
+ */
+static void dhcp6_state_machine(bool timeout, uchar *rx_pkt, unsigned int len)
+{
+ int rand_minus_plus_100;
+
+ switch (sm_params.curr_state) {
+ case DHCP6_INIT:
+ sm_params.next_state = DHCP6_SOLICIT;
+ break;
+ case DHCP6_SOLICIT:
+ if (!timeout) {
+ /* check the rx packet and determine if we can transition to next
+ * state.
+ */
+ if (dhcp6_check_advertise_packet(rx_pkt, len))
+ return;
+
+ debug("ADVERTISE good, transition to REQUEST\n");
+ sm_params.next_state = DHCP6_REQUEST;
+ } else if (sm_params.retry_cnt == 1) {
+ /* If a server UID was received in the first SOLICIT period
+ * transition to REQUEST
+ */
+ if (sm_params.server_uid.uid_ptr)
+ sm_params.next_state = DHCP6_REQUEST;
+ }
+ break;
+ case DHCP6_REQUEST:
+ if (!timeout) {
+ /* check the rx packet and determine if we can transition to next state */
+ if (dhcp6_check_reply_packet(rx_pkt, len))
+ return;
+
+ debug("REPLY good, transition to DONE\n");
+ sm_params.next_state = DHCP6_DONE;
+ }
+ break;
+ case DHCP6_DONE:
+ case DHCP6_FAIL:
+ /* Shouldn't get here, as state machine should exit
+ * immediately when DHCP6_DONE or DHCP6_FAIL is entered.
+ * Proceed anyway to proceed DONE/FAIL actions
+ */
+ debug("Unexpected DHCP6 state : %d\n", sm_params.curr_state);
+ break;
+ }
+ /* re-seed the RNG */
+ srand(get_ticks() + rand());
+
+ /* handle state machine entry conditions */
+ if (sm_params.curr_state != sm_params.next_state) {
+ sm_params.retry_cnt = 0;
+
+ if (sm_params.next_state == DHCP6_SOLICIT) {
+ /* delay a random ammount (special for SOLICIT) */
+ udelay((rand() % SOL_MAX_DELAY_MS) * 1000);
+ /* init timestamp variables after SOLICIT delay */
+ sm_params.dhcp6_start_ms = get_timer(0);
+ sm_params.dhcp6_retry_start_ms = sm_params.dhcp6_start_ms;
+ sm_params.dhcp6_retry_ms = sm_params.dhcp6_start_ms;
+ /* init transaction and ia_id */
+ sm_params.trans_id = rand() & 0xFFFFFF;
+ sm_params.ia_id = rand();
+ /* initialize retransmission parameters */
+ sm_params.irt_ms = SOL_TIMEOUT_MS;
+ sm_params.mrt_ms = updated_sol_max_rt_ms;
+ /* RFCs default MRC is be 0 (try infinitely)
+ * give up after CONFIG_NET_RETRY_COUNT number of tries (same as DHCPv4)
+ */
+ sm_params.mrc = CONFIG_NET_RETRY_COUNT;
+ sm_params.mrd_ms = 0;
+
+ } else if (sm_params.next_state == DHCP6_REQUEST) {
+ /* init timestamp variables */
+ sm_params.dhcp6_retry_start_ms = get_timer(0);
+ sm_params.dhcp6_retry_ms = sm_params.dhcp6_start_ms;
+ /* initialize retransmission parameters */
+ sm_params.irt_ms = REQ_TIMEOUT_MS;
+ sm_params.mrt_ms = REQ_MAX_RT_MS;
+ sm_params.mrc = REQ_MAX_RC;
+ sm_params.mrd_ms = 0;
+ }
+ }
+
+ if (timeout)
+ sm_params.dhcp6_retry_ms = get_timer(0);
+
+ /* Check if MRC or MRD have been passed */
+ if ((sm_params.mrc != 0 &&
+ sm_params.retry_cnt >= sm_params.mrc) ||
+ (sm_params.mrd_ms != 0 &&
+ ((sm_params.dhcp6_retry_ms - sm_params.dhcp6_retry_start_ms) >= sm_params.mrd_ms))) {
+ sm_params.next_state = DHCP6_FAIL;
+ }
+
+ /* calculate retransmission timeout (RT) */
+ rand_minus_plus_100 = ((rand() % 200) - 100);
+ if (sm_params.retry_cnt == 0) {
+ sm_params.rt_ms = sm_params.irt_ms +
+ ((sm_params.irt_ms * rand_minus_plus_100) / 1000);
+ } else {
+ sm_params.rt_ms = (2 * sm_params.rt_prev_ms) +
+ ((sm_params.rt_prev_ms * rand_minus_plus_100) / 1000);
+ }
+
+ if (sm_params.rt_ms > sm_params.mrt_ms) {
+ sm_params.rt_ms = sm_params.mrt_ms +
+ ((sm_params.mrt_ms * rand_minus_plus_100) / 1000);
+ }
+
+ sm_params.rt_prev_ms = sm_params.rt_ms;
+
+ net_set_timeout_handler(sm_params.rt_ms, dhcp6_timeout_handler);
+
+ /* send transmit/retransmit message or fail */
+ sm_params.curr_state = sm_params.next_state;
+
+ if (sm_params.curr_state == DHCP6_SOLICIT) {
+ /* send solicit packet */
+ dhcp6_send_solicit_packet();
+ printf("DHCP6 SOLICIT %d\n", sm_params.retry_cnt);
+ } else if (sm_params.curr_state == DHCP6_REQUEST) {
+ /* send request packet */
+ dhcp6_send_request_packet();
+ printf("DHCP6 REQUEST %d\n", sm_params.retry_cnt);
+ } else if (sm_params.curr_state == DHCP6_DONE) {
+ net_set_timeout_handler(0, NULL);
+
+ /* Duplicate address detection (DAD) should be
+ * performed here before setting net_ip6
+ * (enhancement should be considered)
+ */
+ net_copy_ip6(&net_ip6, &sm_params.rx_status.ia_addr_ipv6);
+ printf("DHCP6 client bound to %pI6c\n", &net_ip6);
+ /* will load with TFTP6 */
+ net_auto_load();
+ } else if (sm_params.curr_state == DHCP6_FAIL) {
+ printf("DHCP6 FAILED, TERMINATING\n");
+ net_set_state(NETLOOP_FAIL);
+ }
+ sm_params.retry_cnt++;
+}
+
+/*
+ * Timeout for DHCP6 SOLICIT/REQUEST.
+ */
+static void dhcp6_timeout_handler(void)
+{
+ /* call state machine with the timeout flag */
+ dhcp6_state_machine(true, NULL, 0);
+}
+
+/*
+ * Start or restart DHCP6
+ */
+void dhcp6_start(void)
+{
+ memset(&sm_params, 0, sizeof(struct dhcp6_sm_params));
+
+ /* seed the RNG with MAC address */
+ srand_mac();
+
+ sm_params.curr_state = DHCP6_INIT;
+ dhcp6_state_machine(false, NULL, 0);
+}
diff --git a/net/dhcpv6.h b/net/dhcpv6.h
new file mode 100644
index 0000000000..6a0158127a
--- /dev/null
+++ b/net/dhcpv6.h
@@ -0,0 +1,212 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) Microsoft Corporation
+ * Author: Sean Edmond <seanedmond@microsoft.com>
+ *
+ */
+
+#ifndef __DHCP6_H__
+#define __DHCP6_H__
+
+#include <net6.h>
+#include <net.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];
+};
+
+/* Send a DHCPv6 request */
+void dhcp6_start(void);
+
+#endif /* __DHCP6_H__ */
diff --git a/net/net.c b/net/net.c
index c9a749f6cc..73d5b2bc80 100644
--- a/net/net.c
+++ b/net/net.c
@@ -122,6 +122,9 @@
#endif
#include <net/tcp.h>
#include <net/wget.h>
+#if defined(CONFIG_CMD_DHCP6)
+#include "dhcpv6.h"
+#endif

/** BOOTP EXTENTIONS **/

@@ -135,6 +138,10 @@ struct in_addr net_dns_server;
/* Our 2nd DNS IP address */
struct in_addr net_dns_server2;
#endif
+#if defined(CONFIG_DHCP6_PXE_DHCP_OPTION)
+/* Indicates whether the pxe path prefix / config file was specified in dhcp option */
+char *pxelinux_configfile;
+#endif

/** END OF BOOTP EXTENTIONS **/

@@ -510,6 +517,11 @@ restart:
dhcp_request(); /* Basically same as BOOTP */
break;
#endif
+#if defined(CONFIG_CMD_DHCP6)
+ case DHCP6:
+ dhcp6_start();
+ break;
+#endif
#if defined(CONFIG_CMD_BOOTP)
case BOOTP:
bootp_reset();
--
2.40.0