/* * Copyright (C) 2006 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** @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 - 20 /* IP header */ - 8 /* UDP header */ ), DHCP_CLIENT_ARCHITECTURE, DHCP_WORD ( 0 ), DHCP_CLIENT_NDI, DHCP_OPTION ( 1 /* UNDI */ , 2, 1 /* v2.1 */ ), 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_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 }; /** Options common to all DHCP requests */ static struct dhcp_options dhcp_request_options = { .data = dhcp_request_options_data, .max_len = sizeof ( dhcp_request_options_data ), .len = sizeof ( dhcp_request_options_data ), }; /** 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 ); /** 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 /** * 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 DHCPNONE: 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"; } } /** * 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; } /**************************************************************************** * * DHCP settings * */ /** A DHCP settings block */ struct dhcp_settings { /** Reference counter */ struct refcnt refcnt; /** DHCP packet */ struct dhcp_packet dhcppkt; /** Setting interface */ struct settings settings; }; /** * Increment reference count on DHCP settings block * * @v dhcpset DHCP settings block * @ret dhcpset DHCP settings block */ static inline __attribute__ (( always_inline )) struct dhcp_settings * dhcpset_get ( struct dhcp_settings *dhcpset ) { ref_get ( &dhcpset->refcnt ); return dhcpset; } /** * Decrement reference count on DHCP settings block * * @v dhcpset DHCP settings block */ static inline __attribute__ (( always_inline )) void dhcpset_put ( struct dhcp_settings *dhcpset ) { ref_put ( &dhcpset->refcnt ); } /** * Store value of DHCP setting * * @v settings Settings block * @v setting Setting to store * @v data Setting data, or NULL to clear setting * @v len Length of setting data * @ret rc Return status code */ static int dhcpset_store ( struct settings *settings, struct setting *setting, const void *data, size_t len ) { struct dhcp_settings *dhcpset = container_of ( settings, struct dhcp_settings, settings ); return dhcppkt_store ( &dhcpset->dhcppkt, setting->tag, data, len ); } /** * Fetch value of DHCP setting * * @v settings Settings block, or NULL to search all blocks * @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 dhcpset_fetch ( struct settings *settings, struct setting *setting, void *data, size_t len ) { struct dhcp_settings *dhcpset = container_of ( settings, struct dhcp_settings, settings ); return dhcppkt_fetch ( &dhcpset->dhcppkt, setting->tag, data, len ); } /** DHCP settings operations */ static struct settings_operations dhcpset_settings_operations = { .store = dhcpset_store, .fetch = dhcpset_fetch, }; /** * Create DHCP setting block * * @v dhcphdr DHCP packet * @v len Length of DHCP packet * @ret dhcpset DHCP settings block */ static struct dhcp_settings * dhcpset_create ( const struct dhcphdr *dhcphdr, size_t len ) { struct dhcp_settings *dhcpset; void *data; dhcpset = zalloc ( sizeof ( *dhcpset ) + len ); if ( dhcpset ) { data = ( ( ( void * ) dhcpset ) + sizeof ( *dhcpset ) ); memcpy ( data, dhcphdr, len ); dhcppkt_init ( &dhcpset->dhcppkt, data, len ); settings_init ( &dhcpset->settings, &dhcpset_settings_operations, &dhcpset->refcnt, DHCP_SETTINGS_NAME ); } return dhcpset; } /** DHCP server address setting */ struct setting dhcp_server_setting __setting = { .name = "dhcp-server", .description = "DHCP server address", .tag = DHCP_SERVER_IDENTIFIER, .type = &setting_type_ipv4, }; /**************************************************************************** * * DHCP session * */ /** DHCP session states */ enum dhcp_session_state { /** Sending DHCPDISCOVERs, collecting DHCPOFFERs and ProxyDHCPOFFERs */ DHCP_STATE_DISCOVER = 0, /** Sending DHCPREQUESTs, waiting for DHCPACK */ DHCP_STATE_REQUEST, /** Sending ProxyDHCPREQUESTs, waiting for ProxyDHCPACK */ DHCP_STATE_PROXYREQUEST, }; /** * Name a DHCP session state * * @v state DHCP session state * @ret string DHCP session state name */ static inline const char * dhcp_state_name ( enum dhcp_session_state state ) { switch ( state ) { case DHCP_STATE_DISCOVER: return "DHCPDISCOVER"; case DHCP_STATE_REQUEST: return "DHCPREQUEST"; case DHCP_STATE_PROXYREQUEST: return "ProxyDHCPREQUEST"; default: return ""; } } /** 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; /** State of the session * * This is a value for the @c DHCP_MESSAGE_TYPE option * (e.g. @c DHCPDISCOVER). */ enum dhcp_session_state state; /** DHCPOFFER obtained during DHCPDISCOVER */ struct dhcp_settings *dhcpoffer; /** ProxyDHCPOFFER obtained during DHCPDISCOVER */ struct dhcp_settings *proxydhcpoffer; /** Retransmission timer */ struct retry_timer timer; /** Start time of the current state (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 ); dhcpset_put ( dhcp->dhcpoffer ); dhcpset_put ( dhcp->proxydhcpoffer ); 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 * */ /** * Create a DHCP packet * * @v dhcppkt DHCP packet structure to fill in * @v netdev Network device * @v msgtype DHCP message type * @v options Initial options to include (or NULL) * @v data Buffer for DHCP packet * @v max_len Size of DHCP packet buffer * @ret rc Return status code * * Creates a DHCP packet in the specified buffer, and fills out a @c * dhcp_packet structure. */ int dhcp_create_packet ( struct dhcp_packet *dhcppkt, struct net_device *netdev, uint8_t msgtype, struct dhcp_options *options, void *data, size_t max_len ) { struct dhcphdr *dhcphdr = data; size_t options_len; unsigned int hlen; int rc; /* Sanity check */ options_len = ( options ? options->len : 0 ); if ( max_len < ( sizeof ( *dhcphdr ) + options_len ) ) 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 ); memcpy ( dhcphdr->options, options->data, options_len ); /* Initialise DHCP packet structure */ memset ( dhcppkt, 0, sizeof ( *dhcppkt ) ); dhcppkt_init ( dhcppkt, data, max_len ); /* Set DHCP_MESSAGE_TYPE option */ if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_MESSAGE_TYPE, &msgtype, sizeof ( msgtype ) ) ) != 0 ) return rc; return 0; } /** * Create DHCP request packet * * @v dhcppkt DHCP packet structure to fill in * @v netdev Network device * @v ciaddr Client IP address * @v offer DHCP offer, if applicable * @v data Buffer for DHCP packet * @v max_len Size of DHCP packet buffer * @ret rc Return status code */ int dhcp_create_request ( struct dhcp_packet *dhcppkt, struct net_device *netdev, struct in_addr ciaddr, struct dhcp_packet *offer, void *data, size_t max_len ) { 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; unsigned int msgtype; size_t dhcp_features_len; size_t ll_addr_len; int rc; /* Create DHCP packet */ msgtype = ( offer ? DHCPREQUEST : DHCPDISCOVER ); if ( ( rc = dhcp_create_packet ( dhcppkt, netdev, msgtype, &dhcp_request_options, data, max_len ) ) != 0 ) { DBG ( "DHCP could not create DHCP packet: %s\n", strerror ( rc ) ); return rc; } /* Set client IP address */ dhcppkt->dhcphdr->ciaddr = ciaddr; /* Copy any required options from previous server repsonse */ if ( offer ) { struct in_addr server = { 0 }; struct in_addr *ip = &offer->dhcphdr->yiaddr; /* Copy server identifier, if present */ if ( ( dhcppkt_fetch ( offer, DHCP_SERVER_IDENTIFIER, &server, sizeof ( server ) ) >= 0 ) && ( ( rc = dhcppkt_store ( dhcppkt, DHCP_SERVER_IDENTIFIER, &server, sizeof ( server ) ) ) != 0 ) ) { DBG ( "DHCP could not set server ID: %s\n", strerror ( rc ) ); return rc; } /* Copy requested IP address, if present */ if ( ( ip->s_addr != 0 ) && ( ( rc = dhcppkt_store ( dhcppkt, DHCP_REQUESTED_ADDRESS, ip, sizeof ( *ip ) ) ) != 0 ) ) { DBG ( "DHCP could not set requested address: %s\n", strerror ( rc ) ); return rc; } } /* Add options to identify the feature list */ dhcp_features_len = ( dhcp_features_end - dhcp_features ); if ( ( rc = dhcppkt_store ( 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 = dhcppkt_store ( 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 = ntohs ( 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 = dhcppkt_store ( 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 = fetch_uuid_setting ( NULL, &uuid_setting, &client_uuid.uuid ) ) >= 0 ) { if ( ( rc = dhcppkt_store ( 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; } /** * Transmit DHCP request * * @v dhcp DHCP session * @ret rc Return status code */ static int dhcp_tx ( struct dhcp_session *dhcp ) { static struct sockaddr_in proxydhcp_server = { .sin_family = AF_INET, .sin_port = htons ( PROXYDHCP_PORT ), }; struct xfer_metadata meta = { .netdev = dhcp->netdev, }; struct io_buffer *iobuf; struct dhcp_packet dhcppkt; struct dhcp_packet *offer = NULL; struct in_addr ciaddr = { 0 }; int check_len; int rc; /* Start retry timer. Do this first so that failures to * transmit will be retried. */ start_timer ( &dhcp->timer ); /* Determine packet contents based on current state */ switch ( dhcp->state ) { case DHCP_STATE_DISCOVER: DBGC ( dhcp, "DHCP %p transmitting DHCPDISCOVER\n", dhcp ); break; case DHCP_STATE_REQUEST: DBGC ( dhcp, "DHCP %p transmitting DHCPREQUEST\n", dhcp ); assert ( dhcp->dhcpoffer ); offer = &dhcp->dhcpoffer->dhcppkt; break; case DHCP_STATE_PROXYREQUEST: DBGC ( dhcp, "DHCP %p transmitting ProxyDHCPREQUEST\n", dhcp ); assert ( dhcp->dhcpoffer ); assert ( dhcp->proxydhcpoffer ); offer = &dhcp->proxydhcpoffer->dhcppkt; ciaddr = dhcp->dhcpoffer->dhcppkt.dhcphdr->yiaddr; check_len = dhcppkt_fetch ( offer, DHCP_SERVER_IDENTIFIER, &proxydhcp_server.sin_addr, sizeof(proxydhcp_server.sin_addr)); meta.dest = ( struct sockaddr * ) &proxydhcp_server; assert ( ciaddr.s_addr != 0 ); assert ( proxydhcp_server.sin_addr.s_addr != 0 ); assert ( check_len == sizeof ( proxydhcp_server.sin_addr ) ); break; default: assert ( 0 ); break; } /* 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 = dhcp_create_request ( &dhcppkt, dhcp->netdev, ciaddr, offer, iobuf->data, iob_tailroom ( iobuf ) ) ) != 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; } /** * Transition to new DHCP session state * * @v dhcp DHCP session * @v state New session state */ static void dhcp_set_state ( struct dhcp_session *dhcp, enum dhcp_session_state state ) { DBGC ( dhcp, "DHCP %p entering %s state\n", dhcp, dhcp_state_name ( state ) ); dhcp->state = state; dhcp->start = currticks(); start_timer_nodelay ( &dhcp->timer ); } /** * Store received DHCPOFFER * * @v dhcp DHCP session * @v dhcpoffer Received DHCPOFFER * @v stored_dhcpoffer Location to store DHCPOFFER * * The DHCPOFFER will be stored in place of the existing stored * DHCPOFFER if its priority is equal to or greater than the stored * DHCPOFFER. */ static void dhcp_store_dhcpoffer ( struct dhcp_session *dhcp, struct dhcp_settings *dhcpoffer, struct dhcp_settings **stored_dhcpoffer ) { uint8_t stored_priority = 0; uint8_t priority = 0; /* Get priorities of the two DHCPOFFERs */ if ( *stored_dhcpoffer ) { dhcppkt_fetch ( &(*stored_dhcpoffer)->dhcppkt, DHCP_EB_PRIORITY, &stored_priority, sizeof ( stored_priority ) ); } dhcppkt_fetch ( &dhcpoffer->dhcppkt, DHCP_EB_PRIORITY, &priority, sizeof ( priority ) ); /* Replace stored offer only if priority is equal or greater */ if ( priority >= stored_priority ) { if ( *stored_dhcpoffer ) { DBGC ( dhcp, "DHCP %p stored DHCPOFFER %p discarded\n", dhcp, *stored_dhcpoffer ); } DBGC ( dhcp, "DHCP %p received DHCPOFFER %p stored\n", dhcp, dhcpoffer ); dhcpset_put ( *stored_dhcpoffer ); *stored_dhcpoffer = dhcpset_get ( dhcpoffer ); } } /** * Handle received DHCPOFFER * * @v dhcp DHCP session * @v dhcpoffer Received DHCPOFFER */ static void dhcp_rx_dhcpoffer ( struct dhcp_session *dhcp, struct dhcp_settings *dhcpoffer ) { struct in_addr server_id = { 0 }; char vci[9]; /* "PXEClient" */ int len; uint8_t ignore_proxy = 0; unsigned long elapsed; /* Check for presence of DHCP server ID */ if ( dhcppkt_fetch ( &dhcpoffer->dhcppkt, DHCP_SERVER_IDENTIFIER, &server_id, sizeof ( server_id ) ) != sizeof ( server_id ) ) { DBGC ( dhcp, "DHCP %p received DHCPOFFER %p missing server " "identifier\n", dhcp, dhcpoffer ); /* Could be a valid BOOTP offer; do not abort processing */ } /* If there is an IP address, it's a normal DHCPOFFER */ if ( dhcpoffer->dhcppkt.dhcphdr->yiaddr.s_addr != 0 ) { DBGC ( dhcp, "DHCP %p received DHCPOFFER %p from %s has IP " "address\n", dhcp, dhcpoffer, inet_ntoa ( server_id ) ); dhcp_store_dhcpoffer ( dhcp, dhcpoffer, &dhcp->dhcpoffer ); } /* If there is a "PXEClient" vendor class ID, it's a * ProxyDHCPOFFER. Note that it could be both a normal * DHCPOFFER and a ProxyDHCPOFFER. */ len = dhcppkt_fetch ( &dhcpoffer->dhcppkt, DHCP_VENDOR_CLASS_ID, vci, sizeof ( vci ) ); if ( ( server_id.s_addr != 0 ) && ( len >= ( int ) sizeof ( vci ) ) && ( strncmp ( "PXEClient", vci, sizeof ( vci ) ) == 0 ) ) { DBGC ( dhcp, "DHCP %p received DHCPOFFER %p from %s is a " "ProxyDHCPOFFER\n", dhcp, dhcpoffer, inet_ntoa ( server_id ) ); dhcp_store_dhcpoffer ( dhcp, dhcpoffer, &dhcp->proxydhcpoffer ); } /* We can transition to making the DHCPREQUEST when we have a * valid DHCPOFFER, and either: * * o The DHCPOFFER instructs us to not wait for ProxyDHCP, or * o We have a valid ProxyDHCPOFFER, or * o We have allowed sufficient time for ProxyDHCPOFFERs. */ /* If we don't yet have a DHCPOFFER, do nothing */ if ( ! dhcp->dhcpoffer ) return; /* If the DHCPOFFER instructs us to ignore ProxyDHCP, discard * any ProxyDHCPOFFER */ dhcppkt_fetch ( &dhcp->dhcpoffer->dhcppkt, DHCP_EB_NO_PROXYDHCP, &ignore_proxy, sizeof ( ignore_proxy ) ); if ( ignore_proxy && dhcp->proxydhcpoffer ) { DBGC ( dhcp, "DHCP %p discarding ProxyDHCPOFFER\n", dhcp ); dhcpset_put ( dhcp->proxydhcpoffer ); dhcp->proxydhcpoffer = NULL; } /* If we can't yet transition to DHCPREQUEST, do nothing */ elapsed = ( currticks() - dhcp->start ); if ( ! ( ignore_proxy || dhcp->proxydhcpoffer || ( elapsed > PROXYDHCP_WAIT_TIME ) ) ) return; /* Transition to DHCPREQUEST */ dhcp_set_state ( dhcp, DHCP_STATE_REQUEST ); } /** * Store received DHCPACK * * @v dhcp DHCP session * @v dhcpack Received DHCPACK * * The DHCPACK will be registered as a settings block. */ static int dhcp_store_dhcpack ( struct dhcp_session *dhcp, struct dhcp_settings *dhcpack, struct settings *parent ) { struct settings *settings = &dhcpack->settings; struct settings *old_settings; int rc; /* Unregister any old settings obtained via DHCP */ if ( ( old_settings = find_child_settings ( parent, settings->name ) )) unregister_settings ( old_settings ); /* Register new settings */ if ( ( rc = register_settings ( settings, parent ) ) != 0 ) { DBGC ( dhcp, "DHCP %p could not register settings: %s\n", dhcp, strerror ( rc ) ); dhcp_finished ( dhcp, rc ); /* This is a fatal error */ return rc; } return 0; } /** * Handle received DHCPACK * * @v dhcp DHCP session * @v dhcpack Received DHCPACK */ static void dhcp_rx_dhcpack ( struct dhcp_session *dhcp, struct dhcp_settings *dhcpack ) { struct settings *parent; struct in_addr offer_server_id = { 0 }; struct in_addr ack_server_id = { 0 }; int rc; /* Verify server ID matches */ assert ( dhcp->dhcpoffer != NULL ); dhcppkt_fetch ( &dhcp->dhcpoffer->dhcppkt, DHCP_SERVER_IDENTIFIER, &offer_server_id, sizeof ( offer_server_id ) ); dhcppkt_fetch ( &dhcpack->dhcppkt, DHCP_SERVER_IDENTIFIER, &ack_server_id, sizeof ( ack_server_id ) ); if ( offer_server_id.s_addr != ack_server_id.s_addr ) { DBGC ( dhcp, "DHCP %p ignoring DHCPACK with wrong server ID " "%s\n", dhcp, inet_ntoa ( ack_server_id ) ); return; } /* Register settings */ parent = netdev_settings ( dhcp->netdev ); if ( ( rc = dhcp_store_dhcpack ( dhcp, dhcpack, parent ) ) !=0 ) return; /* If we have a ProxyDHCPOFFER, transition to PROXYDHCPREQUEST */ if ( dhcp->proxydhcpoffer ) { dhcp->timer.min_timeout = 0; dhcp_set_state ( dhcp, DHCP_STATE_PROXYREQUEST ); return; } /* Terminate DHCP */ dhcp_finished ( dhcp, 0 ); } /** * Handle received ProxyDHCPACK * * @v dhcp DHCP session * @v proxydhcpack Received ProxyDHCPACK */ static void dhcp_rx_proxydhcpack ( struct dhcp_session *dhcp, struct dhcp_settings *proxydhcpack ) { struct in_addr offer_server_id = { 0 }; struct in_addr ack_server_id = { 0 }; int rc; /* Verify server ID matches */ assert ( dhcp->proxydhcpoffer != NULL ); dhcppkt_fetch ( &dhcp->proxydhcpoffer->dhcppkt, DHCP_SERVER_IDENTIFIER, &offer_server_id, sizeof ( offer_server_id ) ); dhcppkt_fetch ( &proxydhcpack->dhcppkt, DHCP_SERVER_IDENTIFIER, &ack_server_id, sizeof ( ack_server_id ) ); if ( offer_server_id.s_addr != ack_server_id.s_addr ) { DBGC ( dhcp, "DHCP %p ignoring ProxyDHCPACK with wrong server " "ID %s\n", dhcp, inet_ntoa ( ack_server_id ) ); return; } /* Rename settings */ proxydhcpack->settings.name = PROXYDHCP_SETTINGS_NAME; /* Register settings */ if ( ( rc = dhcp_store_dhcpack ( dhcp, proxydhcpack, NULL ) ) != 0 ) return; /* Terminate DHCP */ dhcp_finished ( dhcp, 0 ); } /** * Receive new data * * @v xfer Data transfer interface * @v iobuf I/O buffer * @v meta Transfer metadata * @ret rc Return status code */ static int dhcp_deliver_iob ( struct xfer_interface *xfer, struct io_buffer *iobuf, struct xfer_metadata *meta ) { struct dhcp_session *dhcp = container_of ( xfer, struct dhcp_session, xfer ); struct sockaddr_tcpip *st_src; unsigned int src_port; struct dhcp_settings *dhcpset; struct dhcphdr *dhcphdr; uint8_t msgtype = 0; int rc = 0; /* Sanity checks */ if ( ! meta ) { DBGC ( dhcp, "DHCP %p received packet without metadata\n", dhcp ); rc = -EINVAL; goto err_no_meta; } if ( ! meta->src ) { DBGC ( dhcp, "DHCP %p received packet without source port\n", dhcp ); rc = -EINVAL; goto err_no_src; } st_src = ( struct sockaddr_tcpip * ) meta->src; src_port = st_src->st_port; /* Convert packet into a DHCP settings block */ dhcpset = dhcpset_create ( iobuf->data, iob_len ( iobuf ) ); if ( ! dhcpset ) { DBGC ( dhcp, "DHCP %p could not store DHCP packet\n", dhcp ); rc = -ENOMEM; goto err_dhcpset_create; } dhcphdr = dhcpset->dhcppkt.dhcphdr; /* Identify message type */ dhcppkt_fetch ( &dhcpset->dhcppkt, DHCP_MESSAGE_TYPE, &msgtype, sizeof ( msgtype ) ); DBGC ( dhcp, "DHCP %p received %s %p from port %d\n", dhcp, dhcp_msgtype_name ( msgtype ), dhcpset, ntohs ( src_port ) ); /* Check for matching transaction ID */ if ( dhcphdr->xid != dhcp_xid ( dhcp->netdev ) ) { DBGC ( dhcp, "DHCP %p received %s %p has bad transaction ID\n", dhcp, dhcp_msgtype_name ( msgtype ), dhcpset ); rc = -EINVAL; goto err_xid; }; /* Handle packet based on current state */ switch ( dhcp->state ) { case DHCP_STATE_DISCOVER: if ( ( ( msgtype == DHCPOFFER ) || ( msgtype == DHCPNONE ) ) && ( src_port == htons ( BOOTPS_PORT ) ) ) dhcp_rx_dhcpoffer ( dhcp, dhcpset ); break; case DHCP_STATE_REQUEST: if ( ( ( msgtype == DHCPACK ) || ( msgtype == DHCPNONE ) ) && ( src_port == htons ( BOOTPS_PORT ) ) ) dhcp_rx_dhcpack ( dhcp, dhcpset ); break; case DHCP_STATE_PROXYREQUEST: if ( ( msgtype == DHCPACK ) && ( src_port == htons ( PROXYDHCP_PORT ) ) ) dhcp_rx_proxydhcpack ( dhcp, dhcpset ); break; default: assert ( 0 ); break; } err_xid: dhcpset_put ( dhcpset ); err_dhcpset_create: err_no_src: err_no_meta: free_iob ( iobuf ); return rc; } /** DHCP data transfer interface operations */ static struct xfer_interface_operations dhcp_xfer_operations = { .close = ignore_xfer_close, .vredirect = xfer_vopen, .window = unlimited_xfer_window, .alloc_iob = default_xfer_alloc_iob, .deliver_iob = dhcp_deliver_iob, .deliver_raw = xfer_deliver_as_iob, }; /** * 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 ); unsigned long elapsed = ( currticks() - dhcp->start ); /* If we have failed, terminate DHCP */ if ( fail ) { dhcp_finished ( dhcp, -ETIMEDOUT ); return; } /* Give up waiting for ProxyDHCP before we reach the failure point */ if ( dhcp->dhcpoffer && ( elapsed > PROXYDHCP_WAIT_TIME ) ) { if ( dhcp->state == DHCP_STATE_DISCOVER ) { dhcp_set_state ( dhcp, DHCP_STATE_REQUEST ); return; } else if ( dhcp->state == DHCP_STATE_PROXYREQUEST ) { dhcp_finished ( dhcp, 0 ); return; } } /* Otherwise, retransmit current packet */ dhcp_tx ( dhcp ); } /**************************************************************************** * * 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 ) { 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->timer.expired = dhcp_timer_expired; dhcp->timer.min_timeout = DHCP_MIN_TIMEOUT; dhcp->timer.max_timeout = DHCP_MAX_TIMEOUT; 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; }