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- /*
- * Copyright (C) 2006 Michael Brown <mbrown@fensystems.co.uk>.
- *
- * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
- #include <string.h>
- #include <stdlib.h>
- #include <stdio.h>
- #include <errno.h>
- #include <assert.h>
- #include <byteswap.h>
- #include <gpxe/if_ether.h>
- #include <gpxe/netdevice.h>
- #include <gpxe/device.h>
- #include <gpxe/xfer.h>
- #include <gpxe/open.h>
- #include <gpxe/job.h>
- #include <gpxe/retry.h>
- #include <gpxe/tcpip.h>
- #include <gpxe/ip.h>
- #include <gpxe/uuid.h>
- #include <gpxe/dhcp.h>
-
- /** @file
- *
- * Dynamic Host Configuration Protocol
- *
- */
-
- /** DHCP operation types
- *
- * This table maps from DHCP message types (i.e. values of the @c
- * DHCP_MESSAGE_TYPE option) to values of the "op" field within a DHCP
- * packet.
- */
- static const uint8_t dhcp_op[] = {
- [DHCPDISCOVER] = BOOTP_REQUEST,
- [DHCPOFFER] = BOOTP_REPLY,
- [DHCPREQUEST] = BOOTP_REQUEST,
- [DHCPDECLINE] = BOOTP_REQUEST,
- [DHCPACK] = BOOTP_REPLY,
- [DHCPNAK] = BOOTP_REPLY,
- [DHCPRELEASE] = BOOTP_REQUEST,
- [DHCPINFORM] = BOOTP_REQUEST,
- };
-
- /** Raw option data for options common to all DHCP requests */
- static uint8_t dhcp_request_options_data[] = {
- DHCP_MAX_MESSAGE_SIZE, DHCP_WORD ( ETH_MAX_MTU ),
- DHCP_VENDOR_CLASS_ID,
- DHCP_STRING ( 'P', 'X', 'E', 'C', 'l', 'i', 'e', 'n', 't', ':',
- 'A', 'r', 'c', 'h', ':', '0', '0', '0', '0', '0', ':',
- 'U', 'N', 'D', 'I', ':', '0', '0', '2', '0', '0', '1' ),
- DHCP_CLIENT_ARCHITECTURE, DHCP_WORD ( 0 ),
- DHCP_CLIENT_NDI, DHCP_OPTION ( 1 /* UNDI */ , 2, 1 /* v2.1 */ ),
- DHCP_PARAMETER_REQUEST_LIST,
- DHCP_OPTION ( DHCP_SUBNET_MASK, DHCP_ROUTERS, DHCP_DNS_SERVERS,
- DHCP_LOG_SERVERS, DHCP_HOST_NAME, DHCP_DOMAIN_NAME,
- DHCP_ROOT_PATH, DHCP_VENDOR_ENCAP, DHCP_VENDOR_CLASS_ID,
- DHCP_TFTP_SERVER_NAME, DHCP_BOOTFILE_NAME,
- DHCP_EB_ENCAP, DHCP_ISCSI_INITIATOR_IQN ),
- DHCP_END
- };
-
- /** DHCP feature codes */
- static uint8_t dhcp_features[0] __table_start ( uint8_t, dhcp_features );
- static uint8_t dhcp_features_end[0] __table_end ( uint8_t, dhcp_features );
-
- /**
- * Name a DHCP packet type
- *
- * @v msgtype DHCP message type
- * @ret string DHCP mesasge type name
- */
- static inline const char * dhcp_msgtype_name ( unsigned int msgtype ) {
- switch ( msgtype ) {
- case 0: return "BOOTP"; /* Non-DHCP packet */
- case DHCPDISCOVER: return "DHCPDISCOVER";
- case DHCPOFFER: return "DHCPOFFER";
- case DHCPREQUEST: return "DHCPREQUEST";
- case DHCPDECLINE: return "DHCPDECLINE";
- case DHCPACK: return "DHCPACK";
- case DHCPNAK: return "DHCPNAK";
- case DHCPRELEASE: return "DHCPRELEASE";
- case DHCPINFORM: return "DHCPINFORM";
- default: return "DHCP<invalid>";
- }
- }
-
- /**
- * Calculate DHCP transaction ID for a network device
- *
- * @v netdev Network device
- * @ret xid DHCP XID
- *
- * Extract the least significant bits of the hardware address for use
- * as the transaction ID.
- */
- static uint32_t dhcp_xid ( struct net_device *netdev ) {
- uint32_t xid;
-
- memcpy ( &xid, ( netdev->ll_addr + netdev->ll_protocol->ll_addr_len
- - sizeof ( xid ) ), sizeof ( xid ) );
- return xid;
- }
-
- /** Options common to all DHCP requests */
- static struct dhcp_option_block dhcp_request_options = {
- .data = dhcp_request_options_data,
- .max_len = sizeof ( dhcp_request_options_data ),
- .len = sizeof ( dhcp_request_options_data ),
- };
-
- /**
- * Set option within DHCP packet
- *
- * @v dhcppkt DHCP packet
- * @v tag DHCP option tag
- * @v data New value for DHCP option
- * @v len Length of value, in bytes
- * @ret rc Return status code
- *
- * Sets the option within the first available options block within the
- * DHCP packet. Option blocks are tried in the order specified by @c
- * dhcp_option_block_fill_order.
- *
- * The magic options @c DHCP_EB_YIADDR and @c DHCP_EB_SIADDR are
- * intercepted and inserted into the appropriate fixed fields within
- * the DHCP packet. The option @c DHCP_OPTION_OVERLOAD is silently
- * ignored, since our DHCP packet assembly method relies on always
- * having option overloading in use.
- */
- static int set_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
- unsigned int tag, const void *data,
- size_t len ) {
- struct dhcphdr *dhcphdr = dhcppkt->dhcphdr;
- struct dhcp_option_block *options = &dhcppkt->options;
- struct dhcp_option *option = NULL;
-
- /* Special-case the magic options */
- switch ( tag ) {
- case DHCP_OPTION_OVERLOAD:
- /* Hard-coded in packets we create; always ignore */
- return 0;
- case DHCP_EB_YIADDR:
- memcpy ( &dhcphdr->yiaddr, data, sizeof ( dhcphdr->yiaddr ) );
- return 0;
- case DHCP_EB_SIADDR:
- memcpy ( &dhcphdr->siaddr, data, sizeof ( dhcphdr->siaddr ) );
- return 0;
- case DHCP_TFTP_SERVER_NAME:
- memset ( dhcphdr->sname, 0, sizeof ( dhcphdr->sname ) );
- if ( len > sizeof ( dhcphdr->sname ) )
- len = sizeof ( dhcphdr->sname );
- memcpy ( dhcphdr->sname, data, len );
- return 0;
- case DHCP_BOOTFILE_NAME:
- memset ( dhcphdr->file, 0, sizeof ( dhcphdr->file ) );
- if ( len > sizeof ( dhcphdr->file ) )
- len = sizeof ( dhcphdr->file );
- memcpy ( dhcphdr->file, data, len );
- return 0;
- default:
- /* Continue processing as normal */
- break;
- }
-
- /* Set option */
- option = set_dhcp_option ( options, tag, data, len );
-
- /* Update DHCP packet length */
- dhcppkt->len = ( offsetof ( typeof ( *dhcppkt->dhcphdr ), options )
- + dhcppkt->options.len );
-
- return ( option ? 0 : -ENOSPC );
- }
-
- /**
- * Copy option into DHCP packet
- *
- * @v dhcppkt DHCP packet
- * @v options DHCP option block, or NULL
- * @v tag DHCP option tag to search for
- * @v new_tag DHCP option tag to use for copied option
- * @ret rc Return status code
- *
- * Copies a single option, if present, from the DHCP options block
- * into a DHCP packet. The tag for the option may be changed if
- * desired; this is required by other parts of the DHCP code.
- *
- * @c options may specify a single options block, or be left as NULL
- * in order to search for the option within all registered options
- * blocks.
- */
- static int copy_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
- struct dhcp_option_block *options,
- unsigned int tag, unsigned int new_tag ) {
- struct dhcp_option *option;
- int rc;
-
- option = find_dhcp_option ( options, tag );
- if ( option ) {
- if ( ( rc = set_dhcp_packet_option ( dhcppkt, new_tag,
- &option->data,
- option->len ) ) != 0 )
- return rc;
- }
- return 0;
- }
-
- /**
- * Copy options into DHCP packet
- *
- * @v dhcppkt DHCP packet
- * @v options DHCP option block, or NULL
- * @v encapsulator Encapsulating option, or zero
- * @ret rc Return status code
- *
- * Copies options with the specified encapsulator from DHCP options
- * blocks into a DHCP packet. Most options are copied verbatim.
- * Recognised encapsulated options fields are handled as such.
- *
- * @c options may specify a single options block, or be left as NULL
- * in order to copy options from all registered options blocks.
- */
- static int copy_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
- struct dhcp_option_block *options,
- unsigned int encapsulator ) {
- unsigned int subtag;
- unsigned int tag;
- int rc;
-
- for ( subtag = DHCP_MIN_OPTION; subtag <= DHCP_MAX_OPTION; subtag++ ) {
- tag = DHCP_ENCAP_OPT ( encapsulator, subtag );
- switch ( tag ) {
- case DHCP_EB_ENCAP:
- case DHCP_VENDOR_ENCAP:
- /* Process encapsulated options field */
- if ( ( rc = copy_dhcp_packet_encap_options ( dhcppkt,
- options,
- tag)) !=0)
- return rc;
- break;
- default:
- /* Copy option to reassembled packet */
- if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
- tag, tag ) ) !=0)
- return rc;
- break;
- };
- }
-
- return 0;
- }
-
- /**
- * Copy options into DHCP packet
- *
- * @v dhcppkt DHCP packet
- * @v options DHCP option block, or NULL
- * @ret rc Return status code
- *
- * Copies options from DHCP options blocks into a DHCP packet. Most
- * options are copied verbatim. Recognised encapsulated options
- * fields are handled as such.
- *
- * @c options may specify a single options block, or be left as NULL
- * in order to copy options from all registered options blocks.
- */
- static int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
- struct dhcp_option_block *options ) {
- return copy_dhcp_packet_encap_options ( dhcppkt, options, 0 );
- }
-
- /**
- * Create a DHCP packet
- *
- * @v netdev Network device
- * @v msgtype DHCP message type
- * @v data Buffer for DHCP packet
- * @v max_len Size of DHCP packet buffer
- * @v dhcppkt DHCP packet structure to fill in
- * @ret rc Return status code
- *
- * Creates a DHCP packet in the specified buffer, and fills out a @c
- * dhcp_packet structure that can be passed to
- * set_dhcp_packet_option() or copy_dhcp_packet_options().
- */
- static int create_dhcp_packet ( struct net_device *netdev, uint8_t msgtype,
- void *data, size_t max_len,
- struct dhcp_packet *dhcppkt ) {
- struct dhcphdr *dhcphdr = data;
- unsigned int hlen;
- int rc;
-
- /* Sanity check */
- if ( max_len < sizeof ( *dhcphdr ) )
- return -ENOSPC;
-
- /* Initialise DHCP packet content */
- memset ( dhcphdr, 0, max_len );
- dhcphdr->xid = dhcp_xid ( netdev );
- dhcphdr->magic = htonl ( DHCP_MAGIC_COOKIE );
- dhcphdr->htype = ntohs ( netdev->ll_protocol->ll_proto );
- dhcphdr->op = dhcp_op[msgtype];
- /* If hardware length exceeds the chaddr field length, don't
- * use the chaddr field. This is as per RFC4390.
- */
- hlen = netdev->ll_protocol->ll_addr_len;
- if ( hlen > sizeof ( dhcphdr->chaddr ) ) {
- hlen = 0;
- dhcphdr->flags = htons ( BOOTP_FL_BROADCAST );
- }
- dhcphdr->hlen = hlen;
- memcpy ( dhcphdr->chaddr, netdev->ll_addr, hlen );
-
- /* Initialise DHCP packet structure */
- dhcppkt->dhcphdr = dhcphdr;
- dhcppkt->max_len = max_len;
- init_dhcp_options ( &dhcppkt->options, dhcphdr->options,
- ( max_len -
- offsetof ( typeof ( *dhcphdr ), options ) ) );
-
- /* Set DHCP_MESSAGE_TYPE option */
- if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_MESSAGE_TYPE,
- &msgtype,
- sizeof ( msgtype ) ) ) != 0 )
- return rc;
-
- return 0;
- }
-
- /**
- * Calculate used length of a field containing DHCP options
- *
- * @v data Field containing DHCP options
- * @v max_len Field length
- * @ret len Used length (excluding the @c DHCP_END tag)
- */
- static size_t dhcp_field_len ( const void *data, size_t max_len ) {
- struct dhcp_option_block options;
- struct dhcp_option *end;
-
- options.data = ( ( void * ) data );
- options.len = max_len;
- end = find_dhcp_option ( &options, DHCP_END );
- return ( end ? ( ( ( void * ) end ) - data ) : 0 );
- }
-
- /**
- * Merge field containing DHCP options or string into DHCP options block
- *
- * @v options DHCP option block
- * @v data Field containing DHCP options
- * @v max_len Field length
- * @v tag DHCP option tag, or 0
- *
- * If @c tag is non-zero (and the field is not empty), the field will
- * be treated as a NUL-terminated string representing the value of the
- * specified DHCP option. If @c tag is zero, the field will be
- * treated as a block of DHCP options, and simply appended to the
- * existing options in the option block.
- *
- * The caller must ensure that there is enough space in the options
- * block to perform the merge.
- */
- static void merge_dhcp_field ( struct dhcp_option_block *options,
- const void *data, size_t max_len,
- unsigned int tag ) {
- size_t len;
- void *dest;
- struct dhcp_option *end;
-
- if ( tag ) {
- len = strlen ( data );
- if ( len )
- set_dhcp_option ( options, tag, data, len );
- } else {
- len = dhcp_field_len ( data, max_len );
- dest = ( options->data + options->len - 1 );
- memcpy ( dest, data, len );
- options->len += len;
- end = ( dest + len );
- end->tag = DHCP_END;
- }
- }
-
- /**
- * Parse DHCP packet and construct DHCP options block
- *
- * @v dhcphdr DHCP packet
- * @v len Length of DHCP packet
- * @ret options DHCP options block, or NULL
- *
- * Parses a received DHCP packet and canonicalises its contents into a
- * single DHCP options block. The "file" and "sname" fields are
- * converted into the corresponding DHCP options (@c
- * DHCP_BOOTFILE_NAME and @c DHCP_TFTP_SERVER_NAME respectively). If
- * these fields are used for option overloading, their options are
- * merged in to the options block.
- *
- * The values of the "yiaddr" and "siaddr" fields will be stored
- * within the options block as the magic options @c DHCP_EB_YIADDR and
- * @c DHCP_EB_SIADDR.
- *
- * Note that this call allocates new memory for the constructed DHCP
- * options block; it is the responsibility of the caller to eventually
- * free this memory.
- */
- static struct dhcp_option_block * dhcp_parse ( const struct dhcphdr *dhcphdr,
- size_t len ) {
- struct dhcp_option_block *options;
- size_t options_len;
- unsigned int overloading;
-
- /* Sanity check */
- if ( len < sizeof ( *dhcphdr ) )
- return NULL;
-
- /* Calculate size of resulting concatenated option block:
- *
- * The "options" field : length of the field minus the DHCP_END tag.
- *
- * The "file" field : maximum length of the field minus the
- * NUL terminator, plus a 2-byte DHCP header or, if used for
- * option overloading, the length of the field minus the
- * DHCP_END tag.
- *
- * The "sname" field : as for the "file" field.
- *
- * 15 bytes for an encapsulated options field to contain the
- * value of the "yiaddr" and "siaddr" fields
- *
- * 1 byte for a final terminating DHCP_END tag.
- */
- options_len = ( ( len - offsetof ( typeof ( *dhcphdr ), options ) ) - 1
- + ( sizeof ( dhcphdr->file ) + 1 )
- + ( sizeof ( dhcphdr->sname ) + 1 )
- + 15 /* yiaddr and siaddr */
- + 1 /* DHCP_END tag */ );
-
- /* Allocate empty options block of required size */
- options = alloc_dhcp_options ( options_len );
- if ( ! options ) {
- DBG ( "DHCP could not allocate %zd-byte option block\n",
- options_len );
- return NULL;
- }
-
- /* Merge in "options" field, if this is a DHCP packet */
- if ( dhcphdr->magic == htonl ( DHCP_MAGIC_COOKIE ) ) {
- merge_dhcp_field ( options, dhcphdr->options,
- ( len -
- offsetof ( typeof (*dhcphdr), options ) ),
- 0 /* Always contains options */ );
- }
-
- /* Identify overloaded fields */
- overloading = find_dhcp_num_option ( options, DHCP_OPTION_OVERLOAD );
-
- /* Merge in "file" and "sname" fields */
- merge_dhcp_field ( options, dhcphdr->file, sizeof ( dhcphdr->file ),
- ( ( overloading & DHCP_OPTION_OVERLOAD_FILE ) ?
- 0 : DHCP_BOOTFILE_NAME ) );
- merge_dhcp_field ( options, dhcphdr->sname, sizeof ( dhcphdr->sname ),
- ( ( overloading & DHCP_OPTION_OVERLOAD_SNAME ) ?
- 0 : DHCP_TFTP_SERVER_NAME ) );
-
- /* Set magic options for "yiaddr" and "siaddr", if present */
- if ( dhcphdr->yiaddr.s_addr ) {
- set_dhcp_option ( options, DHCP_EB_YIADDR,
- &dhcphdr->yiaddr, sizeof (dhcphdr->yiaddr) );
- }
- if ( dhcphdr->siaddr.s_addr ) {
- set_dhcp_option ( options, DHCP_EB_SIADDR,
- &dhcphdr->siaddr, sizeof (dhcphdr->siaddr) );
- }
-
- assert ( options->len <= options->max_len );
-
- return options;
- }
-
- /****************************************************************************
- *
- * Whole-packet construction
- *
- */
-
- /** DHCP network device descriptor */
- struct dhcp_netdev_desc {
- /** Bus type ID */
- uint8_t type;
- /** Vendor ID */
- uint16_t vendor;
- /** Device ID */
- uint16_t device;
- } __attribute__ (( packed ));
-
- /** DHCP client identifier */
- struct dhcp_client_id {
- /** Link-layer protocol */
- uint8_t ll_proto;
- /** Link-layer address */
- uint8_t ll_addr[MAX_LL_ADDR_LEN];
- } __attribute__ (( packed ));
-
- /** DHCP client UUID */
- struct dhcp_client_uuid {
- /** Identifier type */
- uint8_t type;
- /** UUID */
- union uuid uuid;
- } __attribute__ (( packed ));
-
- #define DHCP_CLIENT_UUID_TYPE 0
-
- /**
- * Create DHCP request
- *
- * @v netdev Network device
- * @v msgtype DHCP message type
- * @v options DHCP server response options, or NULL
- * @v data Buffer for DHCP packet
- * @v max_len Size of DHCP packet buffer
- * @v dhcppkt DHCP packet structure to fill in
- * @ret rc Return status code
- */
- int create_dhcp_request ( struct net_device *netdev, int msgtype,
- struct dhcp_option_block *options,
- void *data, size_t max_len,
- struct dhcp_packet *dhcppkt ) {
- struct device_description *desc = &netdev->dev->desc;
- struct dhcp_netdev_desc dhcp_desc;
- struct dhcp_client_id client_id;
- struct dhcp_client_uuid client_uuid;
- size_t dhcp_features_len;
- size_t ll_addr_len;
- int rc;
-
- /* Create DHCP packet */
- if ( ( rc = create_dhcp_packet ( netdev, msgtype, data, max_len,
- dhcppkt ) ) != 0 ) {
- DBG ( "DHCP could not create DHCP packet: %s\n",
- strerror ( rc ) );
- return rc;
- }
-
- /* Copy in options common to all requests */
- if ( ( rc = copy_dhcp_packet_options ( dhcppkt,
- &dhcp_request_options )) !=0 ){
- DBG ( "DHCP could not set common DHCP options: %s\n",
- strerror ( rc ) );
- return rc;
- }
-
- /* Copy any required options from previous server repsonse */
- if ( options ) {
- if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
- DHCP_SERVER_IDENTIFIER,
- DHCP_SERVER_IDENTIFIER ) ) != 0 ) {
- DBG ( "DHCP could not set server identifier "
- "option: %s\n", strerror ( rc ) );
- return rc;
- }
- if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
- DHCP_EB_YIADDR,
- DHCP_REQUESTED_ADDRESS ) ) != 0 ) {
- DBG ( "DHCP could not set requested address "
- "option: %s\n", strerror ( rc ) );
- return rc;
- }
- }
-
- /* Add options to identify the feature list */
- dhcp_features_len = ( dhcp_features_end - dhcp_features );
- if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_EB_ENCAP,
- dhcp_features,
- dhcp_features_len ) ) != 0 ) {
- DBG ( "DHCP could not set features list option: %s\n",
- strerror ( rc ) );
- return rc;
- }
-
- /* Add options to identify the network device */
- dhcp_desc.type = desc->bus_type;
- dhcp_desc.vendor = htons ( desc->vendor );
- dhcp_desc.device = htons ( desc->device );
- if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_EB_BUS_ID,
- &dhcp_desc,
- sizeof ( dhcp_desc ) ) ) != 0 ) {
- DBG ( "DHCP could not set bus ID option: %s\n",
- strerror ( rc ) );
- return rc;
- }
-
- /* Add DHCP client identifier. Required for Infiniband, and
- * doesn't hurt other link layers.
- */
- client_id.ll_proto = netdev->ll_protocol->ll_proto;
- ll_addr_len = netdev->ll_protocol->ll_addr_len;
- assert ( ll_addr_len <= sizeof ( client_id.ll_addr ) );
- memcpy ( client_id.ll_addr, netdev->ll_addr, ll_addr_len );
- if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_CLIENT_ID,
- &client_id,
- ( ll_addr_len + 1 ) ) ) != 0 ) {
- DBG ( "DHCP could not set client ID: %s\n",
- strerror ( rc ) );
- return rc;
- }
-
- /* Add client UUID, if we have one. Required for PXE. */
- client_uuid.type = DHCP_CLIENT_UUID_TYPE;
- if ( ( rc = get_uuid ( &client_uuid.uuid ) ) == 0 ) {
- if ( ( rc = set_dhcp_packet_option ( dhcppkt,
- DHCP_CLIENT_UUID, &client_uuid,
- sizeof ( client_uuid ) ) ) != 0 ) {
- DBG ( "DHCP could not set client UUID: %s\n",
- strerror ( rc ) );
- return rc;
- }
- }
-
- return 0;
- }
-
- /**
- * Create DHCP response
- *
- * @v netdev Network device
- * @v msgtype DHCP message type
- * @v options DHCP options, or NULL
- * @v data Buffer for DHCP packet
- * @v max_len Size of DHCP packet buffer
- * @v dhcppkt DHCP packet structure to fill in
- * @ret rc Return status code
- */
- int create_dhcp_response ( struct net_device *netdev, int msgtype,
- struct dhcp_option_block *options,
- void *data, size_t max_len,
- struct dhcp_packet *dhcppkt ) {
- int rc;
-
- /* Create packet and copy in options */
- if ( ( rc = create_dhcp_packet ( netdev, msgtype, data, max_len,
- dhcppkt ) ) != 0 ) {
- DBG ( " failed to build packet" );
- return rc;
- }
- if ( ( rc = copy_dhcp_packet_options ( dhcppkt, options ) ) != 0 ) {
- DBG ( " failed to copy options" );
- return rc;
- }
-
- return 0;
- }
-
- /****************************************************************************
- *
- * DHCP to UDP interface
- *
- */
-
- /** A DHCP session */
- struct dhcp_session {
- /** Reference counter */
- struct refcnt refcnt;
- /** Job control interface */
- struct job_interface job;
- /** Data transfer interface */
- struct xfer_interface xfer;
-
- /** Network device being configured */
- struct net_device *netdev;
- /** Option block registration routine */
- int ( * register_options ) ( struct net_device *netdev,
- struct dhcp_option_block *options );
-
- /** State of the session
- *
- * This is a value for the @c DHCP_MESSAGE_TYPE option
- * (e.g. @c DHCPDISCOVER).
- */
- int state;
- /** Options obtained from DHCP server */
- struct dhcp_option_block *options;
- /** Options obtained from ProxyDHCP server */
- struct dhcp_option_block *proxy_options;
- /** Retransmission timer */
- struct retry_timer timer;
- /** Session start time (in ticks) */
- unsigned long start;
- };
-
- /**
- * Free DHCP session
- *
- * @v refcnt Reference counter
- */
- static void dhcp_free ( struct refcnt *refcnt ) {
- struct dhcp_session *dhcp =
- container_of ( refcnt, struct dhcp_session, refcnt );
-
- netdev_put ( dhcp->netdev );
- dhcpopt_put ( dhcp->options );
- dhcpopt_put ( dhcp->proxy_options );
- free ( dhcp );
- }
-
- /**
- * Mark DHCP session as complete
- *
- * @v dhcp DHCP session
- * @v rc Return status code
- */
- static void dhcp_finished ( struct dhcp_session *dhcp, int rc ) {
-
- /* Block futher incoming messages */
- job_nullify ( &dhcp->job );
- xfer_nullify ( &dhcp->xfer );
-
- /* Stop retry timer */
- stop_timer ( &dhcp->timer );
-
- /* Free resources and close interfaces */
- xfer_close ( &dhcp->xfer, rc );
- job_done ( &dhcp->job, rc );
- }
-
- /****************************************************************************
- *
- * Data transfer interface
- *
- */
-
- /**
- * Transmit DHCP request
- *
- * @v dhcp DHCP session
- * @ret rc Return status code
- */
- static int dhcp_send_request ( struct dhcp_session *dhcp ) {
- struct xfer_metadata meta = {
- .netdev = dhcp->netdev,
- };
- struct io_buffer *iobuf;
- struct dhcp_packet dhcppkt;
- int rc;
-
- DBGC ( dhcp, "DHCP %p transmitting %s\n",
- dhcp, dhcp_msgtype_name ( dhcp->state ) );
-
- assert ( ( dhcp->state == DHCPDISCOVER ) ||
- ( dhcp->state == DHCPREQUEST ) );
-
- /* Start retry timer. Do this first so that failures to
- * transmit will be retried.
- */
- start_timer ( &dhcp->timer );
-
- /* Allocate buffer for packet */
- iobuf = xfer_alloc_iob ( &dhcp->xfer, DHCP_MIN_LEN );
- if ( ! iobuf )
- return -ENOMEM;
-
- /* Create DHCP packet in temporary buffer */
- if ( ( rc = create_dhcp_request ( dhcp->netdev, dhcp->state,
- dhcp->options, iobuf->data,
- iob_tailroom ( iobuf ),
- &dhcppkt ) ) != 0 ) {
- DBGC ( dhcp, "DHCP %p could not construct DHCP request: %s\n",
- dhcp, strerror ( rc ) );
- goto done;
- }
-
- /* Transmit the packet */
- iob_put ( iobuf, dhcppkt.len );
- rc = xfer_deliver_iob_meta ( &dhcp->xfer, iobuf, &meta );
- iobuf = NULL;
- if ( rc != 0 ) {
- DBGC ( dhcp, "DHCP %p could not transmit UDP packet: %s\n",
- dhcp, strerror ( rc ) );
- goto done;
- }
-
- done:
- free_iob ( iobuf );
- return rc;
- }
-
- /**
- * Handle DHCP retry timer expiry
- *
- * @v timer DHCP retry timer
- * @v fail Failure indicator
- */
- static void dhcp_timer_expired ( struct retry_timer *timer, int fail ) {
- struct dhcp_session *dhcp =
- container_of ( timer, struct dhcp_session, timer );
-
- if ( fail ) {
- dhcp_finished ( dhcp, -ETIMEDOUT );
- } else {
- dhcp_send_request ( dhcp );
- }
- }
-
- /**
- * Receive new data
- *
- * @v xfer Data transfer interface
- * @v iobuf I/O buffer
- * @v data Received data
- * @v len Length of received data
- * @ret rc Return status code
- */
- static int dhcp_deliver_raw ( struct xfer_interface *xfer,
- const void *data, size_t len ) {
- struct dhcp_session *dhcp =
- container_of ( xfer, struct dhcp_session, xfer );
- const struct dhcphdr *dhcphdr = data;
- struct dhcp_option_block *options;
- struct dhcp_option_block **store_options;
- unsigned int msgtype;
- unsigned long elapsed;
- int is_proxy;
- int ignore_proxy;
-
- /* Check for matching transaction ID */
- if ( dhcphdr->xid != dhcp_xid ( dhcp->netdev ) ) {
- DBGC ( dhcp, "DHCP %p wrong transaction ID (wanted %08lx, "
- "got %08lx)\n", dhcp, ntohl ( dhcphdr->xid ),
- ntohl ( dhcp_xid ( dhcp->netdev ) ) );
- return 0;
- };
-
- /* Parse packet and create options structure */
- options = dhcp_parse ( dhcphdr, len );
- if ( ! options ) {
- DBGC ( dhcp, "DHCP %p could not parse DHCP packet\n", dhcp );
- return -EINVAL;
- }
-
- /* Determine and verify message type */
- is_proxy = ( dhcphdr->yiaddr.s_addr == 0 );
- msgtype = find_dhcp_num_option ( options, DHCP_MESSAGE_TYPE );
- DBGC ( dhcp, "DHCP %p received %s%s\n", dhcp,
- ( is_proxy ? "Proxy" : "" ), dhcp_msgtype_name ( msgtype ) );
- if ( ( ( dhcp->state != DHCPDISCOVER ) || ( msgtype != DHCPOFFER ) ) &&
- ( ( dhcp->state != DHCPREQUEST ) || ( msgtype != DHCPACK ) ) ) {
- DBGC ( dhcp, "DHCP %p discarding %s while in %s state\n",
- dhcp, dhcp_msgtype_name ( msgtype ),
- dhcp_msgtype_name ( dhcp->state ) );
- goto out_discard;
- }
-
- /* Update stored standard/ProxyDHCP options, if the new
- * options have equal or higher priority than the
- * currently-stored options.
- */
- store_options = ( is_proxy ? &dhcp->proxy_options : &dhcp->options );
- if ( ( ! *store_options ) ||
- ( find_dhcp_num_option ( options, DHCP_EB_PRIORITY ) >=
- find_dhcp_num_option ( *store_options, DHCP_EB_PRIORITY ) ) ) {
- dhcpopt_put ( *store_options );
- *store_options = options;
- } else {
- dhcpopt_put ( options );
- }
-
- /* If we don't yet have a standard DHCP response (i.e. one
- * with an IP address), then just leave the timer running.
- */
- if ( ! dhcp->options )
- goto out;
-
- /* Handle DHCP response */
- ignore_proxy = find_dhcp_num_option ( dhcp->options,
- DHCP_EB_NO_PROXYDHCP );
- switch ( dhcp->state ) {
- case DHCPDISCOVER:
- /* If we have allowed sufficient time for ProxyDHCP
- * reponses, then transition to making the DHCPREQUEST.
- */
- elapsed = ( currticks() - dhcp->start );
- if ( ignore_proxy || ( elapsed > PROXYDHCP_WAIT_TIME ) ) {
- stop_timer ( &dhcp->timer );
- dhcp->state = DHCPREQUEST;
- dhcp_send_request ( dhcp );
- }
- break;
- case DHCPREQUEST:
- /* DHCP finished; register options and exit */
- if ( dhcp->proxy_options && ( ! ignore_proxy ) ) {
- dhcp->register_options ( dhcp->netdev,
- dhcp->proxy_options );
- }
- dhcp->register_options ( dhcp->netdev, dhcp->options );
- dhcp_finished ( dhcp, 0 );
- break;
- default:
- assert ( 0 );
- }
-
- out:
- return 0;
-
- out_discard:
- dhcpopt_put ( options );
- return 0;
- }
-
- /** DHCP data transfer interface operations */
- static struct xfer_interface_operations dhcp_xfer_operations = {
- .close = ignore_xfer_close,
- .vredirect = xfer_vopen,
- .seek = ignore_xfer_seek,
- .window = unlimited_xfer_window,
- .deliver_iob = xfer_deliver_as_raw,
- .deliver_raw = dhcp_deliver_raw,
- };
-
- /****************************************************************************
- *
- * Job control interface
- *
- */
-
- /**
- * Handle kill() event received via job control interface
- *
- * @v job DHCP job control interface
- */
- static void dhcp_job_kill ( struct job_interface *job ) {
- struct dhcp_session *dhcp =
- container_of ( job, struct dhcp_session, job );
-
- /* Terminate DHCP session */
- dhcp_finished ( dhcp, -ECANCELED );
- }
-
- /** DHCP job control interface operations */
- static struct job_interface_operations dhcp_job_operations = {
- .done = ignore_job_done,
- .kill = dhcp_job_kill,
- .progress = ignore_job_progress,
- };
-
- /****************************************************************************
- *
- * Instantiator
- *
- */
-
- /**
- * Start DHCP on a network device
- *
- * @v job Job control interface
- * @v netdev Network device
- * @v register_options DHCP option block registration routine
- * @ret rc Return status code
- *
- * Starts DHCP on the specified network device. If successful, the @c
- * register_options() routine will be called with the acquired
- * options.
- */
- int start_dhcp ( struct job_interface *job, struct net_device *netdev,
- int ( * register_options ) ( struct net_device *netdev,
- struct dhcp_option_block * ) ) {
- static struct sockaddr_in server = {
- .sin_family = AF_INET,
- .sin_addr.s_addr = INADDR_BROADCAST,
- .sin_port = htons ( BOOTPS_PORT ),
- };
- static struct sockaddr_in client = {
- .sin_family = AF_INET,
- .sin_port = htons ( BOOTPC_PORT ),
- };
- struct dhcp_session *dhcp;
- int rc;
-
- /* Allocate and initialise structure */
- dhcp = zalloc ( sizeof ( *dhcp ) );
- if ( ! dhcp )
- return -ENOMEM;
- dhcp->refcnt.free = dhcp_free;
- job_init ( &dhcp->job, &dhcp_job_operations, &dhcp->refcnt );
- xfer_init ( &dhcp->xfer, &dhcp_xfer_operations, &dhcp->refcnt );
- dhcp->netdev = netdev_get ( netdev );
- dhcp->register_options = register_options;
- dhcp->timer.expired = dhcp_timer_expired;
- dhcp->state = DHCPDISCOVER;
- dhcp->start = currticks();
-
- /* Instantiate child objects and attach to our interfaces */
- if ( ( rc = xfer_open_socket ( &dhcp->xfer, SOCK_DGRAM,
- ( struct sockaddr * ) &server,
- ( struct sockaddr * ) &client ) ) != 0 )
- goto err;
-
- /* Start timer to initiate initial DHCPREQUEST */
- start_timer_nodelay ( &dhcp->timer );
-
- /* Attach parent interface, mortalise self, and return */
- job_plug_plug ( &dhcp->job, job );
- ref_put ( &dhcp->refcnt );
- return 0;
-
- err:
- dhcp_finished ( dhcp, rc );
- ref_put ( &dhcp->refcnt );
- return rc;
- }
-
- /****************************************************************************
- *
- * Network device configurator
- *
- */
-
- /**
- * Configure network device from DHCP options
- *
- * @v netdev Network device
- * @v options DHCP options block
- * @ret rc Return status code
- */
- int dhcp_configure_netdev ( struct net_device *netdev,
- struct dhcp_option_block *options ) {
- struct in_addr address = { 0 };
- struct in_addr netmask = { 0 };
- struct in_addr gateway = { INADDR_NONE };
- int rc;
-
- /* Retrieve IP address configuration */
- find_dhcp_ipv4_option ( options, DHCP_EB_YIADDR, &address );
- find_dhcp_ipv4_option ( options, DHCP_SUBNET_MASK, &netmask );
- find_dhcp_ipv4_option ( options, DHCP_ROUTERS, &gateway );
-
- /* Do nothing unless we have at least an IP address to use */
- if ( ! address.s_addr )
- return 0;
-
- /* Clear any existing routing table entry */
- del_ipv4_address ( netdev );
-
- /* Set up new IP address configuration */
- if ( ( rc = add_ipv4_address ( netdev, address, netmask,
- gateway ) ) != 0 ) {
- DBG ( "Could not configure %s with DHCP results: %s\n",
- netdev->name, strerror ( rc ) );
- return rc;
- }
-
- return 0;
- }
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