From 2fa34085e28992dd7409496709af822776bd8fc6 Mon Sep 17 00:00:00 2001 From: Michael Brown Date: Fri, 8 Nov 2013 14:35:29 +0000 Subject: [PATCH] [dhcpv6] Add basic support for stateful and stateless DHCPv6 Add support for the stateful and stateless variants of the DHCPv6 protocol. The resulting settings block is registered as "net.dhcpv6", and DHCPv6 options can be obtained using e.g. "${net0.dhcpv6/23:ipv6}" to obtain the IPv6 DNS server address. IPv6 addresses obtained via stateful DHCPv6 are not yet applied to the network device. Signed-off-by: Michael Brown --- src/include/ipxe/dhcpv6.h | 215 +++++++++ src/include/ipxe/errfile.h | 1 + src/net/ndp.c | 41 +- src/net/udp/dhcpv6.c | 955 +++++++++++++++++++++++++++++++++++++ 4 files changed, 1207 insertions(+), 5 deletions(-) create mode 100644 src/include/ipxe/dhcpv6.h create mode 100644 src/net/udp/dhcpv6.c diff --git a/src/include/ipxe/dhcpv6.h b/src/include/ipxe/dhcpv6.h new file mode 100644 index 000000000..7a1a2b07f --- /dev/null +++ b/src/include/ipxe/dhcpv6.h @@ -0,0 +1,215 @@ +#ifndef _IPXE_DHCPV6_H +#define _IPXE_DHCPV6_H + +/** @file + * + * Dynamic Host Configuration Protocol for IPv6 + * + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include +#include + +/** DHCPv6 server port */ +#define DHCPV6_SERVER_PORT 547 + +/** DHCPv6 client port */ +#define DHCPV6_CLIENT_PORT 546 + +/** + * A DHCPv6 option + * + */ +struct dhcpv6_option { + /** Code */ + uint16_t code; + /** Length of the data field */ + uint16_t len; + /** Data */ + uint8_t data[0]; +} __attribute__ (( packed )); + +/** DHCP unique identifier based on link-layer address (DUID-LL) */ +struct dhcpv6_duid_ll { + /** Type */ + uint16_t type; + /** Hardware type */ + uint16_t htype; + /** Link-layer address */ + uint8_t ll_addr[0]; +} __attribute__ (( packed )); + +/** DHCP unique identifier based on link-layer address (DUID-LL) */ +#define DHCPV6_DUID_LL 3 + +/** DHCPv6 client or server identifier option */ +struct dhcpv6_duid_option { + /** Option header */ + struct dhcpv6_option header; + /** DHCP unique identifier (DUID) */ + uint8_t duid[0]; +} __attribute__ (( packed )); + +/** DHCPv6 client identifier option */ +#define DHCPV6_CLIENT_ID 1 + +/** DHCPv6 server identifier option */ +#define DHCPV6_SERVER_ID 2 + +/** DHCPv6 identity association for non-temporary address (IA_NA) option */ +struct dhcpv6_ia_na_option { + /** Option header */ + struct dhcpv6_option header; + /** Identity association identifier (IAID) */ + uint32_t iaid; + /** Renew time (in seconds) */ + uint32_t renew; + /** Rebind time (in seconds) */ + uint32_t rebind; + /** IA_NA options */ + struct dhcpv6_option options[0]; +} __attribute__ (( packed )); + +/** DHCPv6 identity association for non-temporary address (IA_NA) option */ +#define DHCPV6_IA_NA 3 + +/** DHCPv6 identity association address (IAADDR) option */ +struct dhcpv6_iaaddr_option { + /** Option header */ + struct dhcpv6_option header; + /** IPv6 address */ + struct in6_addr address; + /** Preferred lifetime (in seconds) */ + uint32_t preferred; + /** Valid lifetime (in seconds) */ + uint32_t valid; + /** IAADDR options */ + struct dhcpv6_option options[0]; +} __attribute__ (( packed )); + +/** DHCPv6 identity association address (IAADDR) option */ +#define DHCPV6_IAADDR 5 + +/** DHCPv6 option request option */ +struct dhcpv6_option_request_option { + /** Option header */ + struct dhcpv6_option header; + /** Requested options */ + uint16_t requested[0]; +} __attribute__ (( packed )); + +/** DHCPv6 option request option */ +#define DHCPV6_OPTION_REQUEST 6 + +/** DHCPv6 elapsed time option */ +struct dhcpv6_elapsed_time_option { + /** Option header */ + struct dhcpv6_option header; + /** Elapsed time, in centiseconds */ + uint16_t elapsed; +} __attribute__ (( packed )); + +/** DHCPv6 elapsed time option */ +#define DHCPV6_ELAPSED_TIME 8 + +/** DHCPv6 status code option */ +struct dhcpv6_status_code_option { + /** Option header */ + struct dhcpv6_option header; + /** Status code */ + uint16_t status; + /** Status message */ + char message[0]; +} __attribute__ (( packed )); + +/** DHCPv6 status code option */ +#define DHCPV6_STATUS_CODE 13 + +/** DHCPv6 user class */ +struct dhcpv6_user_class { + /** Length */ + uint16_t len; + /** User class string */ + char string[0]; +} __attribute__ (( packed )); + +/** DHCPv6 user class option */ +struct dhcpv6_user_class_option { + /** Option header */ + struct dhcpv6_option header; + /** User class */ + struct dhcpv6_user_class user_class[0]; +} __attribute__ (( packed )); + +/** DHCPv6 user class option */ +#define DHCPV6_USER_CLASS 15 + +/** DHCPv6 DNS recursive name server option */ +#define DHCPV6_DNS_SERVER 23 + +/** DHCPv6 domain search list option */ +#define DHCPV6_DOMAIN_SEARCH 24 + +/** + * Any DHCPv6 option + * + */ +union dhcpv6_any_option { + struct dhcpv6_option header; + struct dhcpv6_duid_option duid; + struct dhcpv6_ia_na_option ia_na; + struct dhcpv6_iaaddr_option iaaddr; + struct dhcpv6_option_request_option option_request; + struct dhcpv6_elapsed_time_option elapsed_time; + struct dhcpv6_status_code_option status_code; + struct dhcpv6_user_class_option user_class; +}; + +/** + * A DHCPv6 header + * + */ +struct dhcpv6_header { + /** Message type */ + uint8_t type; + /** Transaction ID */ + uint8_t xid[3]; + /** Options */ + struct dhcpv6_option options[0]; +} __attribute__ (( packed )); + +/** DHCPv6 solicitation */ +#define DHCPV6_SOLICIT 1 + +/** DHCPv6 advertisement */ +#define DHCPV6_ADVERTISE 2 + +/** DHCPv6 request */ +#define DHCPV6_REQUEST 3 + +/** DHCPv6 reply */ +#define DHCPV6_REPLY 7 + +/** DHCPv6 information request */ +#define DHCPV6_INFORMATION_REQUEST 11 + +/** DHCPv6 settings block name */ +#define DHCPV6_SETTINGS_NAME "dhcpv6" + +/** + * Construct all-DHCP-relay-agents-and-servers multicast address + * + * @v addr Zeroed address to construct + */ +static inline void ipv6_all_dhcp_relay_and_servers ( struct in6_addr *addr ) { + addr->s6_addr16[0] = htons ( 0xff02 ); + addr->s6_addr[13] = 1; + addr->s6_addr[15] = 2; +} + +extern int start_dhcpv6 ( struct interface *job, struct net_device *netdev, + int stateful ); + +#endif /* _IPXE_DHCPV6_H */ diff --git a/src/include/ipxe/errfile.h b/src/include/ipxe/errfile.h index 1db94466a..8e5e30f0a 100644 --- a/src/include/ipxe/errfile.h +++ b/src/include/ipxe/errfile.h @@ -219,6 +219,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #define ERRFILE_socket ( ERRFILE_NET | 0x00380000 ) #define ERRFILE_icmp ( ERRFILE_NET | 0x00390000 ) #define ERRFILE_ping ( ERRFILE_NET | 0x003a0000 ) +#define ERRFILE_dhcpv6 ( ERRFILE_NET | 0x003b0000 ) #define ERRFILE_image ( ERRFILE_IMAGE | 0x00000000 ) #define ERRFILE_elf ( ERRFILE_IMAGE | 0x00010000 ) diff --git a/src/net/ndp.c b/src/net/ndp.c index 1b1109edb..f56bbe928 100644 --- a/src/net/ndp.c +++ b/src/net/ndp.c @@ -29,6 +29,7 @@ FILE_LICENCE ( GPL2_OR_LATER ); #include #include #include +#include #include /** @file @@ -596,6 +597,8 @@ struct ipv6conf { /** Job control interface */ struct interface job; + /** DHCPv6 interface */ + struct interface dhcp; /** Network device being configured */ struct net_device *netdev; @@ -646,6 +649,7 @@ static void ipv6conf_done ( struct ipv6conf *ipv6conf, int rc ) { /* Shut down interfaces */ intf_shutdown ( &ipv6conf->job, rc ); + intf_shutdown ( &ipv6conf->dhcp, rc ); /* Stop timer */ stop_timer ( &ipv6conf->timer ); @@ -686,6 +690,8 @@ static void ipv6conf_expired ( struct retry_timer *timer, int fail ) { static int ipv6conf_rx_router_advertisement ( struct net_device *netdev, unsigned int flags ) { struct ipv6conf *ipv6conf; + int stateful; + int rc; /* Identify IPv6 configurator, if any */ ipv6conf = ipv6conf_demux ( netdev ); @@ -697,13 +703,28 @@ static int ipv6conf_rx_router_advertisement ( struct net_device *netdev, return 0; } - /* Fail if stateful address autoconfiguration is required */ - if ( flags & NDP_ROUTER_MANAGED ) { - ipv6conf_done ( ipv6conf, -ENOTSUP ); - return -ENOTSUP; + /* If this is not the first solicited router advertisement, ignore it */ + if ( ! timer_running ( &ipv6conf->timer ) ) + return 0; + + /* Stop router solicitation timer */ + stop_timer ( &ipv6conf->timer ); + + /* Start DHCPv6 if required */ + if ( flags & ( NDP_ROUTER_MANAGED | NDP_ROUTER_OTHER ) ) { + stateful = ( flags & NDP_ROUTER_MANAGED ); + if ( ( rc = start_dhcpv6 ( &ipv6conf->dhcp, netdev, + stateful ) ) != 0 ) { + DBGC ( netdev, "NDP could not start state%s DHCPv6: " + "%s\n", ( stateful ? "ful" : "less" ), + strerror ( rc ) ); + ipv6conf_done ( ipv6conf, rc ); + return rc; + } + return 0; } - /* Mark autoconfiguration as complete */ + /* Otherwise, terminate autoconfiguration */ ipv6conf_done ( ipv6conf, 0 ); return 0; @@ -718,6 +739,15 @@ static struct interface_operation ipv6conf_job_op[] = { static struct interface_descriptor ipv6conf_job_desc = INTF_DESC ( struct ipv6conf, job, ipv6conf_job_op ); +/** IPv6 configurator DHCPv6 interface operations */ +static struct interface_operation ipv6conf_dhcp_op[] = { + INTF_OP ( intf_close, struct ipv6conf *, ipv6conf_done ), +}; + +/** IPv6 configurator DHCPv6 interface descriptor */ +static struct interface_descriptor ipv6conf_dhcp_desc = + INTF_DESC ( struct ipv6conf, dhcp, ipv6conf_dhcp_op ); + /** * Start IPv6 autoconfiguration * @@ -734,6 +764,7 @@ int start_ipv6conf ( struct interface *job, struct net_device *netdev ) { return -ENOMEM; ref_init ( &ipv6conf->refcnt, ipv6conf_free ); intf_init ( &ipv6conf->job, &ipv6conf_job_desc, &ipv6conf->refcnt ); + intf_init ( &ipv6conf->dhcp, &ipv6conf_dhcp_desc, &ipv6conf->refcnt ); timer_init ( &ipv6conf->timer, ipv6conf_expired, &ipv6conf->refcnt ); ipv6conf->netdev = netdev_get ( netdev ); diff --git a/src/net/udp/dhcpv6.c b/src/net/udp/dhcpv6.c new file mode 100644 index 000000000..ebd7221f9 --- /dev/null +++ b/src/net/udp/dhcpv6.c @@ -0,0 +1,955 @@ +/* + * Copyright (C) 2013 Michael Brown . + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of the + * License, or any later version. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA + * 02110-1301, USA. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** @file + * + * Dynamic Host Configuration Protocol for IPv6 + * + */ + +/* Disambiguate the various error causes */ +#define EPROTO_UNSPECFAIL __einfo_error ( EINFO_EPROTO_UNSPECFAIL ) +#define EINFO_EPROTO_UNSPECFAIL \ + __einfo_uniqify ( EINFO_EPROTO, 1, "Unspecified server failure" ) +#define EPROTO_NOADDRSAVAIL __einfo_error ( EINFO_EPROTO_NOADDRSAVAIL ) +#define EINFO_EPROTO_NOADDRSAVAIL \ + __einfo_uniqify ( EINFO_EPROTO, 2, "No addresses available" ) +#define EPROTO_NOBINDING __einfo_error ( EINFO_EPROTO_NOBINDING ) +#define EINFO_EPROTO_NOBINDING \ + __einfo_uniqify ( EINFO_EPROTO, 3, "Client record unavailable" ) +#define EPROTO_NOTONLINK __einfo_error ( EINFO_EPROTO_NOTONLINK ) +#define EINFO_EPROTO_NOTONLINK \ + __einfo_uniqify ( EINFO_EPROTO, 4, "Prefix not on link" ) +#define EPROTO_USEMULTICAST __einfo_error ( EINFO_EPROTO_USEMULTICAST ) +#define EINFO_EPROTO_USEMULTICAST \ + __einfo_uniqify ( EINFO_EPROTO, 5, "Use multicast address" ) +#define EPROTO_STATUS( status ) \ + EUNIQ ( EINFO_EPROTO, ( (status) & 0x0f ), EPROTO_UNSPECFAIL, \ + EPROTO_NOADDRSAVAIL, EPROTO_NOBINDING, \ + EPROTO_NOTONLINK, EPROTO_USEMULTICAST ) + +/** Human-readable error messages */ +struct errortab dhcpv6_errors[] __errortab = { + __einfo_errortab ( EINFO_EPROTO_NOADDRSAVAIL ), +}; + +/**************************************************************************** + * + * DHCPv6 option lists + * + */ + +/** A DHCPv6 option list */ +struct dhcpv6_option_list { + /** Data buffer */ + const void *data; + /** Length of data buffer */ + size_t len; +}; + +/** + * Find DHCPv6 option + * + * @v options DHCPv6 option list + * @v code Option code + * @ret option DHCPv6 option, or NULL if not found + */ +static const union dhcpv6_any_option * +dhcpv6_option ( struct dhcpv6_option_list *options, unsigned int code ) { + const union dhcpv6_any_option *option = options->data; + size_t remaining = options->len; + size_t data_len; + + /* Scan through list of options */ + while ( remaining >= sizeof ( option->header ) ) { + + /* Calculate and validate option length */ + remaining -= sizeof ( option->header ); + data_len = ntohs ( option->header.len ); + if ( data_len > remaining ) { + /* Malformed option list */ + return NULL; + } + + /* Return if we have found the specified option */ + if ( option->header.code == htons ( code ) ) + return option; + + /* Otherwise, move to the next option */ + option = ( ( ( void * ) option->header.data ) + data_len ); + remaining -= data_len; + } + + return NULL; +} + +/** + * Check DHCPv6 client or server identifier + * + * @v options DHCPv6 option list + * @v code Option code + * @v expected Expected value + * @v len Length of expected value + * @ret rc Return status code + */ +static int dhcpv6_check_duid ( struct dhcpv6_option_list *options, + unsigned int code, const void *expected, + size_t len ) { + const union dhcpv6_any_option *option; + const struct dhcpv6_duid_option *duid; + + /* Find option */ + option = dhcpv6_option ( options, code ); + if ( ! option ) + return -ENOENT; + duid = &option->duid; + + /* Check option length */ + if ( ntohs ( duid->header.len ) != len ) + return -EINVAL; + + /* Compare option value */ + if ( memcmp ( duid->duid, expected, len ) != 0 ) + return -EINVAL; + + return 0; +} + +/** + * Get DHCPv6 status code + * + * @v options DHCPv6 option list + * @ret rc Return status code + */ +static int dhcpv6_status_code ( struct dhcpv6_option_list *options ) { + const union dhcpv6_any_option *option; + const struct dhcpv6_status_code_option *status_code; + unsigned int status; + + /* Find status code option, if present */ + option = dhcpv6_option ( options, DHCPV6_STATUS_CODE ); + if ( ! option ) { + /* Omitted status code should be treated as "success" */ + return 0; + } + status_code = &option->status_code; + + /* Sanity check */ + if ( ntohs ( status_code->header.len ) < + ( sizeof ( *status_code ) - sizeof ( status_code->header ) ) ) { + return -EINVAL; + } + + /* Calculate iPXE error code from DHCPv6 status code */ + status = ntohs ( status_code->status ); + return ( status ? -EPROTO_STATUS ( status ) : 0 ); +} + +/** + * Get DHCPv6 identity association address + * + * @v options DHCPv6 option list + * @v iaid Identity association ID + * @v address IPv6 address to fill in + * @ret rc Return status code + */ +static int dhcpv6_iaaddr ( struct dhcpv6_option_list *options, uint32_t iaid, + struct in6_addr *address ) { + const union dhcpv6_any_option *option; + const struct dhcpv6_ia_na_option *ia_na; + const struct dhcpv6_iaaddr_option *iaaddr; + struct dhcpv6_option_list suboptions; + size_t len; + int rc; + + /* Find identity association option, if present */ + option = dhcpv6_option ( options, DHCPV6_IA_NA ); + if ( ! option ) + return -ENOENT; + ia_na = &option->ia_na; + + /* Sanity check */ + len = ntohs ( ia_na->header.len ); + if ( len < ( sizeof ( *ia_na ) - sizeof ( ia_na->header ) ) ) + return -EINVAL; + + /* Check identity association ID */ + if ( ia_na->iaid != htonl ( iaid ) ) + return -EINVAL; + + /* Construct IA_NA sub-options list */ + suboptions.data = ia_na->options; + suboptions.len = ( len + sizeof ( ia_na->header ) - + offsetof ( typeof ( *ia_na ), options ) ); + + /* Check IA_NA status code */ + if ( ( rc = dhcpv6_status_code ( &suboptions ) ) != 0 ) + return rc; + + /* Find identity association address, if present */ + option = dhcpv6_option ( &suboptions, DHCPV6_IAADDR ); + if ( ! option ) + return -ENOENT; + iaaddr = &option->iaaddr; + + /* Sanity check */ + len = ntohs ( iaaddr->header.len ); + if ( len < ( sizeof ( *iaaddr ) - sizeof ( iaaddr->header ) ) ) + return -EINVAL; + + /* Construct IAADDR sub-options list */ + suboptions.data = iaaddr->options; + suboptions.len = ( len + sizeof ( iaaddr->header ) - + offsetof ( typeof ( *iaaddr ), options ) ); + + /* Check IAADDR status code */ + if ( ( rc = dhcpv6_status_code ( &suboptions ) ) != 0 ) + return rc; + + /* Extract IPv6 address */ + memcpy ( address, &iaaddr->address, sizeof ( *address ) ); + + return 0; +} + +/**************************************************************************** + * + * DHCPv6 settings blocks + * + */ + +/** DHCPv6 settings scope */ +static struct settings_scope dhcpv6_settings_scope; + +/** A DHCPv6 settings block */ +struct dhcpv6_settings { + /** Reference count */ + struct refcnt refcnt; + /** Settings block */ + struct settings settings; + /** Option list */ + struct dhcpv6_option_list options; +}; + +/** + * Check applicability of DHCPv6 setting + * + * @v settings Settings block + * @v setting Setting + * @ret applies Setting applies within this settings block + */ +static int dhcpv6_applies ( struct settings *settings __unused, + struct setting *setting ) { + + return ( setting->scope == &dhcpv6_settings_scope ); +} + +/** + * Fetch value of DHCPv6 setting + * + * @v settings Settings block + * @v setting Setting to fetch + * @v data Buffer to fill with setting data + * @v len Length of buffer + * @ret len Length of setting data, or negative error + */ +static int dhcpv6_fetch ( struct settings *settings, + struct setting *setting, + void *data, size_t len ) { + struct dhcpv6_settings *dhcpv6set = + container_of ( settings, struct dhcpv6_settings, settings ); + const union dhcpv6_any_option *option; + size_t option_len; + + /* Find option */ + option = dhcpv6_option ( &dhcpv6set->options, setting->tag ); + if ( ! option ) + return -ENOENT; + + /* Copy option to data buffer */ + option_len = ntohs ( option->header.len ); + if ( len > option_len ) + len = option_len; + memcpy ( data, option->header.data, len ); + return option_len; +} + +/** DHCPv6 settings operations */ +static struct settings_operations dhcpv6_settings_operations = { + .applies = dhcpv6_applies, + .fetch = dhcpv6_fetch, +}; + +/** + * Register DHCPv6 options as network device settings + * + * @v options DHCPv6 option list + * @v parent Parent settings block + * @ret rc Return status code + */ +static int dhcpv6_register ( struct dhcpv6_option_list *options, + struct settings *parent ) { + struct dhcpv6_settings *dhcpv6set; + void *data; + size_t len; + int rc; + + /* Allocate and initialise structure */ + dhcpv6set = zalloc ( sizeof ( *dhcpv6set ) + options->len ); + if ( ! dhcpv6set ) { + rc = -ENOMEM; + goto err_alloc; + } + ref_init ( &dhcpv6set->refcnt, NULL ); + settings_init ( &dhcpv6set->settings, &dhcpv6_settings_operations, + &dhcpv6set->refcnt, &dhcpv6_settings_scope ); + data = ( ( ( void * ) dhcpv6set ) + sizeof ( *dhcpv6set ) ); + len = options->len; + memcpy ( data, options->data, len ); + dhcpv6set->options.data = data; + dhcpv6set->options.len = len; + + /* Register settings */ + if ( ( rc = register_settings ( &dhcpv6set->settings, parent, + DHCPV6_SETTINGS_NAME ) ) != 0 ) + goto err_register; + + err_register: + ref_put ( &dhcpv6set->refcnt ); + err_alloc: + return rc; +} + +/**************************************************************************** + * + * DHCPv6 protocol + * + */ + +/** Options to be requested */ +static uint16_t dhcpv6_requested_options[] = { + htons ( DHCPV6_DNS_SERVER ), htons ( DHCPV6_DOMAIN_SEARCH ), +}; + +/** + * Name a DHCPv6 packet type + * + * @v type DHCPv6 packet type + * @ret name DHCPv6 packet type name + */ +static __attribute__ (( unused )) const char * +dhcpv6_type_name ( unsigned int type ) { + static char buf[ 12 /* "UNKNOWN-xxx" + NUL */ ]; + + switch ( type ) { + case DHCPV6_SOLICIT: return "SOLICIT"; + case DHCPV6_ADVERTISE: return "ADVERTISE"; + case DHCPV6_REQUEST: return "REQUEST"; + case DHCPV6_REPLY: return "REPLY"; + case DHCPV6_INFORMATION_REQUEST: return "INFORMATION-REQUEST"; + default: + snprintf ( buf, sizeof ( buf ), "UNKNOWN-%d", type ); + return buf; + } +} + +/** A DHCPv6 session state */ +struct dhcpv6_session_state { + /** Current transmitted packet type */ + uint8_t tx_type; + /** Current expected received packet type */ + uint8_t rx_type; + /** Flags */ + uint8_t flags; + /** Next state (or NULL to terminate) */ + struct dhcpv6_session_state *next; +}; + +/** DHCPv6 session state flags */ +enum dhcpv6_session_state_flags { + /** Include identity association within request */ + DHCPV6_TX_IA_NA = 0x01, + /** Include leased IPv6 address within request */ + DHCPV6_TX_IAADDR = 0x02, + /** Record received server ID */ + DHCPV6_RX_SERVER_ID = 0x04, + /** Record received IPv6 address */ + DHCPV6_RX_IAADDR = 0x08, +}; + +/** DHCPv6 request state */ +static struct dhcpv6_session_state dhcpv6_request = { + .tx_type = DHCPV6_REQUEST, + .rx_type = DHCPV6_REPLY, + .flags = ( DHCPV6_TX_IA_NA | DHCPV6_TX_IAADDR | DHCPV6_RX_IAADDR ), + .next = NULL, +}; + +/** DHCPv6 solicitation state */ +static struct dhcpv6_session_state dhcpv6_solicit = { + .tx_type = DHCPV6_SOLICIT, + .rx_type = DHCPV6_ADVERTISE, + .flags = ( DHCPV6_TX_IA_NA | DHCPV6_RX_SERVER_ID | DHCPV6_RX_IAADDR ), + .next = &dhcpv6_request, +}; + +/** DHCPv6 information request state */ +static struct dhcpv6_session_state dhcpv6_information_request = { + .tx_type = DHCPV6_INFORMATION_REQUEST, + .rx_type = DHCPV6_REPLY, + .flags = 0, + .next = NULL, +}; + +/** A DHCPv6 session */ +struct dhcpv6_session { + /** Reference counter */ + struct refcnt refcnt; + /** Job control interface */ + struct interface job; + /** Data transfer interface */ + struct interface xfer; + + /** Network device being configured */ + struct net_device *netdev; + /** Transaction ID */ + uint8_t xid[3]; + /** Identity association ID */ + uint32_t iaid; + /** Start time (in ticks) */ + unsigned long start; + /** Client DUID */ + void *client_duid; + /** Client DUID length */ + size_t client_duid_len; + /** Server DUID, if known */ + void *server_duid; + /** Server DUID length */ + size_t server_duid_len; + /** Leased IPv6 address */ + struct in6_addr lease; + + /** Retransmission timer */ + struct retry_timer timer; + + /** Current session state */ + struct dhcpv6_session_state *state; + /** Current timeout status code */ + int rc; +}; + +/** + * Free DHCPv6 session + * + * @v refcnt Reference count + */ +static void dhcpv6_free ( struct refcnt *refcnt ) { + struct dhcpv6_session *dhcpv6 = + container_of ( refcnt, struct dhcpv6_session, refcnt ); + + netdev_put ( dhcpv6->netdev ); + free ( dhcpv6->server_duid ); + free ( dhcpv6 ); +} + +/** + * Terminate DHCPv6 session + * + * @v dhcpv6 DHCPv6 session + * @v rc Reason for close + */ +static void dhcpv6_finished ( struct dhcpv6_session *dhcpv6, int rc ) { + + /* Stop timer */ + stop_timer ( &dhcpv6->timer ); + + /* Shut down interfaces */ + intf_shutdown ( &dhcpv6->xfer, rc ); + intf_shutdown ( &dhcpv6->job, rc ); +} + +/** + * Transition to new DHCPv6 session state + * + * @v dhcpv6 DHCPv6 session + * @v state New session state + */ +static void dhcpv6_set_state ( struct dhcpv6_session *dhcpv6, + struct dhcpv6_session_state *state ) { + + DBGC ( dhcpv6, "DHCPv6 %s entering %s state\n", dhcpv6->netdev->name, + dhcpv6_type_name ( state->tx_type ) ); + + /* Record state */ + dhcpv6->state = state; + + /* Default to -ETIMEDOUT if no more specific error is recorded */ + dhcpv6->rc = -ETIMEDOUT; + + /* Start timer to trigger transmission */ + start_timer_nodelay ( &dhcpv6->timer ); +} + +/** + * Get DHCPv6 user class + * + * @v data Data buffer + * @v len Length of data buffer + * @ret len Length of user class + */ +static size_t dhcpv6_user_class ( void *data, size_t len ) { + static const char default_user_class[4] = { 'i', 'P', 'X', 'E' }; + int actual_len; + + /* Fetch user-class setting, if defined */ + actual_len = fetch_setting ( NULL, &user_class_setting, data, len ); + if ( actual_len >= 0 ) + return actual_len; + + /* Otherwise, use the default user class ("iPXE") */ + if ( len > sizeof ( default_user_class ) ) + len = sizeof ( default_user_class ); + memcpy ( data, default_user_class, len ); + return sizeof ( default_user_class ); +} + +/** + * Transmit current request + * + * @v dhcpv6 DHCPv6 session + * @ret rc Return status code + */ +static int dhcpv6_tx ( struct dhcpv6_session *dhcpv6 ) { + struct dhcpv6_duid_option *client_id; + struct dhcpv6_duid_option *server_id; + struct dhcpv6_ia_na_option *ia_na; + struct dhcpv6_iaaddr_option *iaaddr; + struct dhcpv6_option_request_option *option_request; + struct dhcpv6_user_class_option *user_class; + struct dhcpv6_elapsed_time_option *elapsed; + struct dhcpv6_header *dhcphdr; + struct io_buffer *iobuf; + size_t client_id_len; + size_t server_id_len; + size_t ia_na_len; + size_t option_request_len; + size_t user_class_string_len; + size_t user_class_len; + size_t elapsed_len; + size_t total_len; + int rc; + + /* Calculate lengths */ + client_id_len = ( sizeof ( *client_id ) + dhcpv6->client_duid_len ); + server_id_len = ( dhcpv6->server_duid ? ( sizeof ( *server_id ) + + dhcpv6->server_duid_len ) :0); + if ( dhcpv6->state->flags & DHCPV6_TX_IA_NA ) { + ia_na_len = sizeof ( *ia_na ); + if ( dhcpv6->state->flags & DHCPV6_TX_IAADDR ) + ia_na_len += sizeof ( *iaaddr ); + } else { + ia_na_len = 0; + } + option_request_len = ( sizeof ( *option_request ) + + sizeof ( dhcpv6_requested_options ) ); + user_class_string_len = dhcpv6_user_class ( NULL, 0 ); + user_class_len = ( sizeof ( *user_class ) + + sizeof ( user_class->user_class[0] ) + + user_class_string_len ); + elapsed_len = sizeof ( *elapsed ); + total_len = ( sizeof ( *dhcphdr ) + client_id_len + server_id_len + + ia_na_len + option_request_len + user_class_len + + elapsed_len ); + + /* Allocate packet */ + iobuf = xfer_alloc_iob ( &dhcpv6->xfer, total_len ); + if ( ! iobuf ) + return -ENOMEM; + + /* Construct header */ + dhcphdr = iob_put ( iobuf, sizeof ( *dhcphdr ) ); + dhcphdr->type = dhcpv6->state->tx_type; + memcpy ( dhcphdr->xid, dhcpv6->xid, sizeof ( dhcphdr->xid ) ); + + /* Construct client identifier */ + client_id = iob_put ( iobuf, client_id_len ); + client_id->header.code = htons ( DHCPV6_CLIENT_ID ); + client_id->header.len = htons ( client_id_len - + sizeof ( client_id->header ) ); + memcpy ( client_id->duid, dhcpv6->client_duid, + dhcpv6->client_duid_len ); + + /* Construct server identifier, if applicable */ + if ( server_id_len ) { + server_id = iob_put ( iobuf, server_id_len ); + server_id->header.code = htons ( DHCPV6_SERVER_ID ); + server_id->header.len = htons ( server_id_len - + sizeof ( server_id->header ) ); + memcpy ( server_id->duid, dhcpv6->server_duid, + dhcpv6->server_duid_len ); + } + + /* Construct identity association, if applicable */ + if ( ia_na_len ) { + ia_na = iob_put ( iobuf, ia_na_len ); + ia_na->header.code = htons ( DHCPV6_IA_NA ); + ia_na->header.len = htons ( ia_na_len - + sizeof ( ia_na->header ) ); + ia_na->iaid = htonl ( dhcpv6->iaid ); + ia_na->renew = htonl ( 0 ); + ia_na->rebind = htonl ( 0 ); + if ( dhcpv6->state->flags & DHCPV6_TX_IAADDR ) { + iaaddr = ( ( void * ) ia_na->options ); + iaaddr->header.code = htons ( DHCPV6_IAADDR ); + iaaddr->header.len = htons ( sizeof ( *iaaddr ) - + sizeof ( iaaddr->header )); + memcpy ( &iaaddr->address, &dhcpv6->lease, + sizeof ( iaaddr->address ) ); + iaaddr->preferred = htonl ( 0 ); + iaaddr->valid = htonl ( 0 ); + } + } + + /* Construct option request */ + option_request = iob_put ( iobuf, option_request_len ); + option_request->header.code = htons ( DHCPV6_OPTION_REQUEST ); + option_request->header.len = htons ( option_request_len - + sizeof ( option_request->header )); + memcpy ( option_request->requested, dhcpv6_requested_options, + sizeof ( dhcpv6_requested_options ) ); + + /* Construct user class */ + user_class = iob_put ( iobuf, user_class_len ); + user_class->header.code = htons ( DHCPV6_USER_CLASS ); + user_class->header.len = htons ( user_class_len - + sizeof ( user_class->header ) ); + user_class->user_class[0].len = htons ( user_class_string_len ); + dhcpv6_user_class ( user_class->user_class[0].string, + user_class_string_len ); + + /* Construct elapsed time */ + elapsed = iob_put ( iobuf, elapsed_len ); + elapsed->header.code = htons ( DHCPV6_ELAPSED_TIME ); + elapsed->header.len = htons ( elapsed_len - + sizeof ( elapsed->header ) ); + elapsed->elapsed = htons ( ( ( currticks() - dhcpv6->start ) * 100 ) / + TICKS_PER_SEC ); + + /* Sanity check */ + assert ( iob_len ( iobuf ) == total_len ); + + /* Transmit packet */ + if ( ( rc = xfer_deliver_iob ( &dhcpv6->xfer, iobuf ) ) != 0 ) { + DBGC ( dhcpv6, "DHCPv6 %s could not transmit: %s\n", + dhcpv6->netdev->name, strerror ( rc ) ); + return rc; + } + + return 0; +} + +/** + * Handle timer expiry + * + * @v timer Retransmission timer + * @v fail Failure indicator + */ +static void dhcpv6_timer_expired ( struct retry_timer *timer, int fail ) { + struct dhcpv6_session *dhcpv6 = + container_of ( timer, struct dhcpv6_session, timer ); + + /* If we have failed, terminate DHCPv6 */ + if ( fail ) { + dhcpv6_finished ( dhcpv6, dhcpv6->rc ); + return; + } + + /* Restart timer */ + start_timer ( &dhcpv6->timer ); + + /* (Re)transmit current request */ + dhcpv6_tx ( dhcpv6 ); +} + +/** + * Receive new data + * + * @v dhcpv6 DHCPv6 session + * @v iobuf I/O buffer + * @v meta Data transfer metadata + * @ret rc Return status code + */ +static int dhcpv6_rx ( struct dhcpv6_session *dhcpv6, + struct io_buffer *iobuf, + struct xfer_metadata *meta ) { + struct settings *parent = netdev_settings ( dhcpv6->netdev ); + struct sockaddr_in6 *src = ( ( struct sockaddr_in6 * ) meta->src ); + struct dhcpv6_header *dhcphdr = iobuf->data; + struct dhcpv6_option_list options; + const union dhcpv6_any_option *option; + int rc; + + /* Sanity checks */ + if ( iob_len ( iobuf ) < sizeof ( *dhcphdr ) ) { + DBGC ( dhcpv6, "DHCPv6 %s received packet too short (%zd " + "bytes, min %zd bytes)\n", dhcpv6->netdev->name, + iob_len ( iobuf ), sizeof ( *dhcphdr ) ); + rc = -EINVAL; + goto done; + } + assert ( src != NULL ); + assert ( src->sin6_family == AF_INET6 ); + DBGC ( dhcpv6, "DHCPv6 %s received %s from %s\n", + dhcpv6->netdev->name, dhcpv6_type_name ( dhcphdr->type ), + inet6_ntoa ( &src->sin6_addr ) ); + + /* Construct option list */ + options.data = dhcphdr->options; + options.len = ( iob_len ( iobuf ) - + offsetof ( typeof ( *dhcphdr ), options ) ); + + /* Verify client identifier */ + if ( ( rc = dhcpv6_check_duid ( &options, DHCPV6_CLIENT_ID, + dhcpv6->client_duid, + dhcpv6->client_duid_len ) ) != 0 ) { + DBGC ( dhcpv6, "DHCPv6 %s received %s without correct client " + "ID: %s\n", dhcpv6->netdev->name, + dhcpv6_type_name ( dhcphdr->type ), strerror ( rc ) ); + goto done; + } + + /* Verify server identifier, if applicable */ + if ( dhcpv6->server_duid && + ( ( rc = dhcpv6_check_duid ( &options, DHCPV6_SERVER_ID, + dhcpv6->server_duid, + dhcpv6->server_duid_len ) ) != 0 ) ) { + DBGC ( dhcpv6, "DHCPv6 %s received %s without correct server " + "ID: %s\n", dhcpv6->netdev->name, + dhcpv6_type_name ( dhcphdr->type ), strerror ( rc ) ); + goto done; + } + + /* Check message type */ + if ( dhcphdr->type != dhcpv6->state->rx_type ) { + DBGC ( dhcpv6, "DHCPv6 %s received %s while expecting %s\n", + dhcpv6->netdev->name, dhcpv6_type_name ( dhcphdr->type ), + dhcpv6_type_name ( dhcpv6->state->rx_type ) ); + rc = -ENOTTY; + goto done; + } + + /* Fetch status code, if present */ + if ( ( rc = dhcpv6_status_code ( &options ) ) != 0 ) { + DBGC ( dhcpv6, "DHCPv6 %s received %s with error status: %s\n", + dhcpv6->netdev->name, dhcpv6_type_name ( dhcphdr->type ), + strerror ( rc ) ); + /* This is plausibly the error we want to return */ + dhcpv6->rc = rc; + goto done; + } + + /* Record identity association address, if applicable */ + if ( dhcpv6->state->flags & DHCPV6_RX_IAADDR ) { + if ( ( rc = dhcpv6_iaaddr ( &options, dhcpv6->iaid, + &dhcpv6->lease ) ) != 0 ) { + DBGC ( dhcpv6, "DHCPv6 %s received %s with unusable " + "IAADDR: %s\n", dhcpv6->netdev->name, + dhcpv6_type_name ( dhcphdr->type ), + strerror ( rc ) ); + /* This is plausibly the error we want to return */ + dhcpv6->rc = rc; + goto done; + } + DBGC ( dhcpv6, "DHCPv6 %s received %s is for %s\n", + dhcpv6->netdev->name, dhcpv6_type_name ( dhcphdr->type ), + inet6_ntoa ( &dhcpv6->lease ) ); + } + + /* Record server ID, if applicable */ + if ( dhcpv6->state->flags & DHCPV6_RX_SERVER_ID ) { + assert ( dhcpv6->server_duid == NULL ); + option = dhcpv6_option ( &options, DHCPV6_SERVER_ID ); + if ( ! option ) { + DBGC ( dhcpv6, "DHCPv6 %s received %s missing server " + "ID\n", dhcpv6->netdev->name, + dhcpv6_type_name ( dhcphdr->type ) ); + rc = -EINVAL; + goto done; + } + dhcpv6->server_duid_len = ntohs ( option->duid.header.len ); + dhcpv6->server_duid = malloc ( dhcpv6->server_duid_len ); + if ( ! dhcpv6->server_duid ) { + rc = -ENOMEM; + goto done; + } + memcpy ( dhcpv6->server_duid, option->duid.duid, + dhcpv6->server_duid_len ); + } + + /* Transition to next state or complete DHCPv6, as applicable */ + if ( dhcpv6->state->next ) { + + /* Transition to next state */ + dhcpv6_set_state ( dhcpv6, dhcpv6->state->next ); + rc = 0; + + } else { + + /* Register settings */ + if ( ( rc = dhcpv6_register ( &options, parent ) ) != 0 ) { + DBGC ( dhcpv6, "DHCPv6 %s could not register " + "settings: %s\n", dhcpv6->netdev->name, + strerror ( rc ) ); + goto done; + } + + /* Mark as complete */ + dhcpv6_finished ( dhcpv6, 0 ); + DBGC ( dhcpv6, "DHCPv6 %s complete\n", dhcpv6->netdev->name ); + } + + done: + free_iob ( iobuf ); + return rc; +} + +/** DHCPv6 job control interface operations */ +static struct interface_operation dhcpv6_job_op[] = { + INTF_OP ( intf_close, struct dhcpv6_session *, dhcpv6_finished ), +}; + +/** DHCPv6 job control interface descriptor */ +static struct interface_descriptor dhcpv6_job_desc = + INTF_DESC ( struct dhcpv6_session, job, dhcpv6_job_op ); + +/** DHCPv6 data transfer interface operations */ +static struct interface_operation dhcpv6_xfer_op[] = { + INTF_OP ( xfer_deliver, struct dhcpv6_session *, dhcpv6_rx ), +}; + +/** DHCPv6 data transfer interface descriptor */ +static struct interface_descriptor dhcpv6_xfer_desc = + INTF_DESC ( struct dhcpv6_session, xfer, dhcpv6_xfer_op ); + +/** + * Start DHCPv6 + * + * @v job Job control interface + * @v netdev Network device + * @v stateful Perform stateful address autoconfiguration + * @ret rc Return status code + */ +int start_dhcpv6 ( struct interface *job, struct net_device *netdev, + int stateful ) { + struct ll_protocol *ll_protocol = netdev->ll_protocol; + struct dhcpv6_session *dhcpv6; + struct { + union { + struct sockaddr_in6 sin6; + struct sockaddr sa; + } client; + union { + struct sockaddr_in6 sin6; + struct sockaddr sa; + } server; + } addresses; + struct dhcpv6_duid_ll *client_duid; + size_t client_duid_len; + uint32_t xid; + int rc; + + /* Allocate and initialise structure */ + client_duid_len = ( sizeof ( *client_duid ) + ll_protocol->ll_addr_len); + dhcpv6 = zalloc ( sizeof ( *dhcpv6 ) + client_duid_len ); + if ( ! dhcpv6 ) + return -ENOMEM; + ref_init ( &dhcpv6->refcnt, dhcpv6_free ); + intf_init ( &dhcpv6->job, &dhcpv6_job_desc, &dhcpv6->refcnt ); + intf_init ( &dhcpv6->xfer, &dhcpv6_xfer_desc, &dhcpv6->refcnt ); + dhcpv6->netdev = netdev_get ( netdev ); + xid = random(); + memcpy ( dhcpv6->xid, &xid, sizeof ( dhcpv6->xid ) ); + dhcpv6->start = currticks(); + dhcpv6->client_duid = ( ( ( void * ) dhcpv6 ) + sizeof ( *dhcpv6 ) ); + dhcpv6->client_duid_len = client_duid_len; + timer_init ( &dhcpv6->timer, dhcpv6_timer_expired, &dhcpv6->refcnt ); + + /* Construct client and server addresses */ + memset ( &addresses, 0, sizeof ( addresses ) ); + addresses.client.sin6.sin6_family = AF_INET6; + addresses.client.sin6.sin6_scope_id = netdev->index; + addresses.client.sin6.sin6_port = htons ( DHCPV6_CLIENT_PORT ); + addresses.server.sin6.sin6_family = AF_INET6; + ipv6_all_dhcp_relay_and_servers ( &addresses.server.sin6.sin6_addr ); + addresses.server.sin6.sin6_scope_id = netdev->index; + addresses.server.sin6.sin6_port = htons ( DHCPV6_SERVER_PORT ); + + /* Construct client DUID and IAID from link-layer address */ + client_duid = dhcpv6->client_duid; + client_duid->type = htons ( DHCPV6_DUID_LL ); + client_duid->htype = ll_protocol->ll_proto; + memcpy ( client_duid->ll_addr, netdev->ll_addr, + ll_protocol->ll_addr_len ); + dhcpv6->iaid = crc32_le ( 0, netdev->ll_addr, ll_protocol->ll_addr_len); + DBGC ( dhcpv6, "DHCPv6 %s has XID %02x%02x%02x\n", dhcpv6->netdev->name, + dhcpv6->xid[0], dhcpv6->xid[1], dhcpv6->xid[2] ); + + /* Enter initial state */ + dhcpv6_set_state ( dhcpv6, ( stateful ? &dhcpv6_solicit : + &dhcpv6_information_request ) ); + + /* Open socket */ + if ( ( rc = xfer_open_socket ( &dhcpv6->xfer, SOCK_DGRAM, + &addresses.server.sa, + &addresses.client.sa ) ) != 0 ) { + DBGC ( dhcpv6, "DHCPv6 %s could not open socket: %s\n", + dhcpv6->netdev->name, strerror ( rc ) ); + goto err_open_socket; + } + + /* Attach parent interface, mortalise self, and return */ + intf_plug_plug ( &dhcpv6->job, job ); + ref_put ( &dhcpv6->refcnt ); + return 0; + + err_open_socket: + dhcpv6_finished ( dhcpv6, rc ); + ref_put ( &dhcpv6->refcnt ); + return rc; +}