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-rw-r--r--contrib/syslinux-4.02/gpxe/src/net/udp/dhcp.c1587
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diff --git a/contrib/syslinux-4.02/gpxe/src/net/udp/dhcp.c b/contrib/syslinux-4.02/gpxe/src/net/udp/dhcp.c
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+++ b/contrib/syslinux-4.02/gpxe/src/net/udp/dhcp.c
@@ -0,0 +1,1587 @@
+/*
+ * 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.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER );
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <ctype.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/timer.h>
+#include <gpxe/settings.h>
+#include <gpxe/dhcp.h>
+#include <gpxe/dhcpopts.h>
+#include <gpxe/dhcppkt.h>
+#include <gpxe/features.h>
+
+/** @file
+ *
+ * Dynamic Host Configuration Protocol
+ *
+ */
+
+struct dhcp_session;
+static int dhcp_tx ( struct dhcp_session *dhcp );
+
+/**
+ * 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_MESSAGE_TYPE, DHCP_BYTE ( 0 ),
+ 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_USER_CLASS_ID,
+ DHCP_STRING ( 'g', 'P', 'X', 'E' ),
+ 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
+};
+
+/** Version number feature */
+FEATURE_VERSION ( VERSION_MAJOR, VERSION_MINOR, VERSION_PATCH );
+
+/** 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 user class setting */
+struct setting user_class_setting __setting = {
+ .name = "user-class",
+ .description = "User class identifier",
+ .tag = DHCP_USER_CLASS_ID,
+ .type = &setting_type_string,
+};
+
+/** Use cached network settings */
+struct setting use_cached_setting __setting = {
+ .name = "use-cached",
+ .description = "Use cached network settings",
+ .tag = DHCP_EB_USE_CACHED,
+ .type = &setting_type_uint8,
+};
+
+/**
+ * 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<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;
+}
+
+/****************************************************************************
+ *
+ * DHCP session
+ *
+ */
+
+struct dhcp_session;
+
+/** DHCP session state operations */
+struct dhcp_session_state {
+ /** State name */
+ const char *name;
+ /**
+ * Construct transmitted packet
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer Destination address
+ */
+ int ( * tx ) ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer );
+ /** Handle received packet
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer DHCP server address
+ * @v msgtype DHCP message type
+ * @v server_id DHCP server ID
+ */
+ void ( * rx ) ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer,
+ uint8_t msgtype, struct in_addr server_id );
+ /** Handle timer expiry
+ *
+ * @v dhcp DHCP session
+ */
+ void ( * expired ) ( struct dhcp_session *dhcp );
+ /** Transmitted message type */
+ uint8_t tx_msgtype;
+ /** Apply minimum timeout */
+ uint8_t apply_min_timeout;
+};
+
+static struct dhcp_session_state dhcp_state_discover;
+static struct dhcp_session_state dhcp_state_request;
+static struct dhcp_session_state dhcp_state_proxy;
+static struct dhcp_session_state dhcp_state_pxebs;
+
+/** DHCP offer is valid for IP lease */
+#define DHCP_OFFER_IP 1
+
+/** DHCP offer is valid for PXE options */
+#define DHCP_OFFER_PXE 2
+
+/** A DHCP offer */
+struct dhcp_offer {
+ /** IP address of server granting offer */
+ struct in_addr server;
+
+ /** IP address being offered, or 0.0.0.0 for a pure proxy */
+ struct in_addr ip;
+
+ /** DHCP packet containing PXE options; NULL if missing or proxied */
+ struct dhcp_packet *pxe;
+
+ /** Valid uses for this offer, a combination of DHCP_OFFER bits */
+ uint8_t valid;
+
+ /** Priority of this offer */
+ int8_t priority;
+
+ /** Whether to ignore PXE DHCP extensions */
+ uint8_t no_pxedhcp;
+};
+
+/** Maximum number of DHCP offers to queue */
+#define DHCP_MAX_OFFERS 6
+
+/** 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;
+ /** Local socket address */
+ struct sockaddr_in local;
+ /** State of the session */
+ struct dhcp_session_state *state;
+
+ /** PXE Boot Server type */
+ uint16_t pxe_type;
+ /** List of PXE Boot Servers to attempt */
+ struct in_addr *pxe_attempt;
+ /** List of PXE Boot Servers to accept */
+ struct in_addr *pxe_accept;
+
+ /** Retransmission timer */
+ struct retry_timer timer;
+ /** Start time of the current state (in ticks) */
+ unsigned long start;
+
+ /** DHCP offer just requested */
+ struct dhcp_offer *current_offer;
+ /** List of DHCP offers received */
+ struct dhcp_offer offers[DHCP_MAX_OFFERS];
+};
+
+/**
+ * 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 );
+ int i;
+
+ for ( i = 0 ; i < DHCP_MAX_OFFERS ; i++ ) {
+ if ( dhcp->offers[i].pxe )
+ dhcppkt_put ( dhcp->offers[i].pxe );
+ }
+
+ netdev_put ( dhcp->netdev );
+ 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 );
+}
+
+/**
+ * Transition to new DHCP session state
+ *
+ * @v dhcp DHCP session
+ * @v state New session state
+ */
+static void dhcp_set_state ( struct dhcp_session *dhcp,
+ struct dhcp_session_state *state ) {
+
+ DBGC ( dhcp, "DHCP %p entering %s state\n", dhcp, state->name );
+ dhcp->state = state;
+ dhcp->start = currticks();
+ stop_timer ( &dhcp->timer );
+ dhcp->timer.min_timeout =
+ ( state->apply_min_timeout ? DHCP_MIN_TIMEOUT : 0 );
+ dhcp->timer.max_timeout = DHCP_MAX_TIMEOUT;
+ start_timer_nodelay ( &dhcp->timer );
+}
+
+/**
+ * Determine next DHCP offer to try
+ *
+ * @v dhcp DHCP session
+ * @v type DHCP offer type
+ * @ret offer Next DHCP offer to try
+ *
+ * Offers are ranked by priority, then by completeness (combined
+ * IP+PXE are tried before @a type alone), then by order of receipt.
+ */
+static struct dhcp_offer * dhcp_next_offer ( struct dhcp_session *dhcp,
+ uint8_t type ) {
+
+ struct dhcp_offer *offer;
+ struct dhcp_offer *best = NULL;
+
+ for ( offer = dhcp->offers ; offer < dhcp->offers + DHCP_MAX_OFFERS ;
+ offer++ ) {
+ if ( ( offer->valid & type ) &&
+ ( ( best == NULL ) ||
+ ( offer->priority > best->priority ) ||
+ ( ( offer->priority == best->priority ) &&
+ ( offer->valid & ~best->valid ) ) ) )
+ best = offer;
+ }
+
+ return best;
+}
+
+/****************************************************************************
+ *
+ * DHCP state machine
+ *
+ */
+
+/**
+ * Construct transmitted packet for DHCP discovery
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer Destination address
+ */
+static int dhcp_discovery_tx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt __unused,
+ struct sockaddr_in *peer ) {
+
+ DBGC ( dhcp, "DHCP %p DHCPDISCOVER\n", dhcp );
+
+ /* Set server address */
+ peer->sin_addr.s_addr = INADDR_BROADCAST;
+ peer->sin_port = htons ( BOOTPS_PORT );
+
+ return 0;
+}
+
+/**
+ * Handle received DHCPOFFER during any state
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer DHCP server address
+ * @v msgtype DHCP message type
+ * @v server_id DHCP server ID
+ */
+static void dhcp_rx_offer ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer, uint8_t msgtype,
+ struct in_addr server_id ) {
+ char vci[9]; /* "PXEClient" */
+ int vci_len;
+ int has_pxeclient;
+ int pxeopts_len;
+ int has_pxeopts;
+ struct dhcp_offer *offer;
+ int i;
+
+ DBGC ( dhcp, "DHCP %p %s from %s:%d", dhcp,
+ dhcp_msgtype_name ( msgtype ), inet_ntoa ( peer->sin_addr ),
+ ntohs ( peer->sin_port ) );
+ if ( server_id.s_addr != peer->sin_addr.s_addr )
+ DBGC ( dhcp, " (%s)", inet_ntoa ( server_id ) );
+
+ /* Identify offered IP address */
+ if ( dhcppkt->dhcphdr->yiaddr.s_addr )
+ DBGC ( dhcp, " for %s", inet_ntoa ( dhcppkt->dhcphdr->yiaddr ));
+
+ /* Enqueue an offer to be filled in */
+ for ( i = 0 ; i < DHCP_MAX_OFFERS ; i++ ) {
+ if ( dhcp->offers[i].server.s_addr == server_id.s_addr ) {
+ DBGC ( dhcp, " dup\n" );
+ return;
+ }
+
+ if ( ! dhcp->offers[i].valid )
+ break;
+ }
+ if ( i == DHCP_MAX_OFFERS ) {
+ DBGC ( dhcp, " dropped\n" );
+ return;
+ }
+
+ offer = &dhcp->offers[i];
+ offer->server = server_id;
+ offer->ip = dhcppkt->dhcphdr->yiaddr;
+
+ /* Identify "PXEClient" vendor class */
+ vci_len = dhcppkt_fetch ( dhcppkt, DHCP_VENDOR_CLASS_ID,
+ vci, sizeof ( vci ) );
+ has_pxeclient = ( ( vci_len >= ( int ) sizeof ( vci ) ) &&
+ ( strncmp ( "PXEClient", vci, sizeof (vci) ) == 0 ));
+
+ /* Identify presence of PXE-specific options */
+ pxeopts_len = dhcppkt_fetch ( dhcppkt, DHCP_PXE_BOOT_MENU, NULL, 0 );
+ has_pxeopts = ( pxeopts_len >= 0 );
+ if ( has_pxeclient )
+ DBGC ( dhcp, "%s", ( has_pxeopts ? " pxe" : " proxy" ) );
+
+ if ( has_pxeclient && has_pxeopts ) {
+ /* Save reference to packet for future use */
+ if ( offer->pxe )
+ dhcppkt_put ( offer->pxe );
+ offer->pxe = dhcppkt_get ( dhcppkt );
+ }
+
+ /* Identify priority */
+ dhcppkt_fetch ( dhcppkt, DHCP_EB_PRIORITY, &offer->priority,
+ sizeof ( offer->priority ) );
+ if ( offer->priority )
+ DBGC ( dhcp, " pri %d", offer->priority );
+
+ /* Identify ignore-PXE flag */
+ dhcppkt_fetch ( dhcppkt, DHCP_EB_NO_PXEDHCP, &offer->no_pxedhcp,
+ sizeof ( offer->no_pxedhcp ) );
+ if ( offer->no_pxedhcp )
+ DBGC ( dhcp, " nopxe" );
+ DBGC ( dhcp, "\n" );
+
+ /* Determine roles this offer can fill */
+ if ( offer->ip.s_addr &&
+ ( peer->sin_port == htons ( BOOTPS_PORT ) ) &&
+ ( ( msgtype == DHCPOFFER ) || ( ! msgtype /* BOOTP */ ) ) )
+ offer->valid |= DHCP_OFFER_IP;
+
+ if ( has_pxeclient && ( msgtype == DHCPOFFER ) )
+ offer->valid |= DHCP_OFFER_PXE;
+}
+
+/**
+ * Handle received packet during DHCP discovery
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer DHCP server address
+ * @v msgtype DHCP message type
+ * @v server_id DHCP server ID
+ */
+static void dhcp_discovery_rx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer, uint8_t msgtype,
+ struct in_addr server_id ) {
+ unsigned long elapsed;
+ struct dhcp_offer *ip_offer;
+
+ dhcp_rx_offer ( dhcp, dhcppkt, peer, msgtype, server_id );
+
+ /* We can exit the discovery state when we have a valid
+ * DHCPOFFER, and either:
+ *
+ * o The DHCPOFFER instructs us to ignore ProxyDHCPOFFERs, 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 */
+ ip_offer = dhcp_next_offer ( dhcp, DHCP_OFFER_IP );
+ if ( ! ip_offer )
+ return;
+
+ /* If we can't yet transition to DHCPREQUEST, do nothing */
+ elapsed = ( currticks() - dhcp->start );
+ if ( ! ( ip_offer->no_pxedhcp ||
+ dhcp_next_offer ( dhcp, DHCP_OFFER_PXE ) ||
+ ( elapsed > PROXYDHCP_MAX_TIMEOUT ) ) )
+ return;
+
+ /* Transition to DHCPREQUEST */
+ dhcp_set_state ( dhcp, &dhcp_state_request );
+}
+
+/**
+ * Handle timer expiry during DHCP discovery
+ *
+ * @v dhcp DHCP session
+ */
+static void dhcp_discovery_expired ( struct dhcp_session *dhcp ) {
+ unsigned long elapsed = ( currticks() - dhcp->start );
+
+ /* Give up waiting for ProxyDHCP before we reach the failure point */
+ if ( dhcp_next_offer ( dhcp, DHCP_OFFER_IP ) &&
+ ( elapsed > PROXYDHCP_MAX_TIMEOUT ) ) {
+ dhcp_set_state ( dhcp, &dhcp_state_request );
+ return;
+ }
+
+ /* Otherwise, retransmit current packet */
+ dhcp_tx ( dhcp );
+}
+
+/** DHCP discovery state operations */
+static struct dhcp_session_state dhcp_state_discover = {
+ .name = "discovery",
+ .tx = dhcp_discovery_tx,
+ .rx = dhcp_discovery_rx,
+ .expired = dhcp_discovery_expired,
+ .tx_msgtype = DHCPDISCOVER,
+ .apply_min_timeout = 1,
+};
+
+/**
+ * Construct transmitted packet for DHCP request
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer Destination address
+ */
+static int dhcp_request_tx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer ) {
+ int rc;
+ struct dhcp_offer *offer;
+
+ offer = dhcp->current_offer = dhcp_next_offer ( dhcp, DHCP_OFFER_IP );
+
+ DBGC ( dhcp, "DHCP %p DHCPREQUEST to %s:%d",
+ dhcp, inet_ntoa ( offer->server ), BOOTPS_PORT );
+ DBGC ( dhcp, " for %s\n", inet_ntoa ( offer->ip ) );
+
+ /* Set server ID */
+ if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_SERVER_IDENTIFIER,
+ &offer->server,
+ sizeof ( offer->server ) ) ) != 0 )
+ return rc;
+
+ /* Set requested IP address */
+ if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_REQUESTED_ADDRESS,
+ &offer->ip, sizeof ( offer->ip ) ) ) != 0 )
+ return rc;
+
+ /* Set server address */
+ peer->sin_addr.s_addr = INADDR_BROADCAST;
+ peer->sin_port = htons ( BOOTPS_PORT );
+
+ return 0;
+}
+
+/**
+ * Handle received packet during DHCP request
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer DHCP server address
+ * @v msgtype DHCP message type
+ * @v server_id DHCP server ID
+ */
+static void dhcp_request_rx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer, uint8_t msgtype,
+ struct in_addr server_id ) {
+ struct in_addr ip;
+ struct settings *parent;
+ int rc;
+ struct dhcp_offer *pxe_offer;
+
+ if ( msgtype == DHCPOFFER ) {
+ dhcp_rx_offer ( dhcp, dhcppkt, peer, msgtype, server_id );
+ if ( dhcp_next_offer ( dhcp, DHCP_OFFER_IP ) !=
+ dhcp->current_offer ) {
+ /* Restart due to higher-priority offer received */
+ DBGC ( dhcp, "DHCP %p re-requesting\n", dhcp );
+ dhcp_set_state ( dhcp, &dhcp_state_request );
+ }
+ return;
+ }
+
+ DBGC ( dhcp, "DHCP %p %s from %s:%d", dhcp,
+ dhcp_msgtype_name ( msgtype ), inet_ntoa ( peer->sin_addr ),
+ ntohs ( peer->sin_port ) );
+ if ( server_id.s_addr != peer->sin_addr.s_addr )
+ DBGC ( dhcp, " (%s)", inet_ntoa ( server_id ) );
+
+ /* Identify leased IP address */
+ ip = dhcppkt->dhcphdr->yiaddr;
+ if ( ip.s_addr )
+ DBGC ( dhcp, " for %s", inet_ntoa ( ip ) );
+ DBGC ( dhcp, "\n" );
+
+ /* Filter out unacceptable responses */
+ if ( peer->sin_port != htons ( BOOTPS_PORT ) )
+ return;
+ if ( msgtype /* BOOTP */ && ( msgtype != DHCPACK ) )
+ return;
+ if ( server_id.s_addr != dhcp->current_offer->server.s_addr )
+ return;
+
+ /* Record assigned address */
+ dhcp->local.sin_addr = ip;
+
+ /* Register settings */
+ parent = netdev_settings ( dhcp->netdev );
+ if ( ( rc = register_settings ( &dhcppkt->settings, parent ) ) != 0 ){
+ DBGC ( dhcp, "DHCP %p could not register settings: %s\n",
+ dhcp, strerror ( rc ) );
+ dhcp_finished ( dhcp, rc );
+ return;
+ }
+
+ /* Locate best source of PXE settings */
+ pxe_offer = dhcp_next_offer ( dhcp, DHCP_OFFER_PXE );
+
+ if ( ( ! pxe_offer ) || /* No PXE available */
+ /* IP offer instructs us to ignore PXE */
+ dhcp->current_offer->no_pxedhcp ||
+ /* PXE settings already registered with IP offer */
+ ( ( dhcp->current_offer == pxe_offer ) && ( pxe_offer->pxe ) ) ) {
+
+ /* Terminate DHCP */
+ dhcp_finished ( dhcp, 0 );
+
+ } else if ( pxe_offer->pxe ) {
+ /* Register PXE settings and terminate DHCP */
+ pxe_offer->pxe->settings.name = PROXYDHCP_SETTINGS_NAME;
+ if ( ( rc = register_settings ( &pxe_offer->pxe->settings,
+ NULL ) ) != 0 ) {
+ DBGC ( dhcp, "DHCP %p could not register settings: "
+ "%s\n", dhcp, strerror ( rc ) );
+ }
+ dhcp_finished ( dhcp, rc );
+ } else {
+ /* Start ProxyDHCP */
+ dhcp_set_state ( dhcp, &dhcp_state_proxy );
+ }
+}
+
+/**
+ * Handle timer expiry during DHCP discovery
+ *
+ * @v dhcp DHCP session
+ */
+static void dhcp_request_expired ( struct dhcp_session *dhcp ) {
+
+ /* Retransmit current packet */
+ dhcp_tx ( dhcp );
+}
+
+/** DHCP request state operations */
+static struct dhcp_session_state dhcp_state_request = {
+ .name = "request",
+ .tx = dhcp_request_tx,
+ .rx = dhcp_request_rx,
+ .expired = dhcp_request_expired,
+ .tx_msgtype = DHCPREQUEST,
+ .apply_min_timeout = 0,
+};
+
+/**
+ * Construct transmitted packet for ProxyDHCP request
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer Destination address
+ */
+static int dhcp_proxy_tx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer ) {
+ int rc;
+ struct dhcp_offer *offer;
+
+ offer = dhcp->current_offer = dhcp_next_offer ( dhcp, DHCP_OFFER_PXE );
+
+ DBGC ( dhcp, "DHCP %p ProxyDHCP REQUEST to %s:%d\n", dhcp,
+ inet_ntoa ( offer->server ), PXE_PORT );
+
+ /* Set server ID */
+ if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_SERVER_IDENTIFIER,
+ &offer->server,
+ sizeof ( offer->server ) ) ) != 0 )
+ return rc;
+
+ /* Set server address */
+ peer->sin_addr = offer->server;
+ peer->sin_port = htons ( PXE_PORT );
+
+ return 0;
+}
+
+/**
+ * Handle received packet during ProxyDHCP request
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer DHCP server address
+ * @v msgtype DHCP message type
+ * @v server_id DHCP server ID
+ */
+static void dhcp_proxy_rx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer, uint8_t msgtype,
+ struct in_addr server_id ) {
+ int rc;
+
+ /* Enqueue last-minute DHCPOFFERs for use in case of failure */
+ if ( peer->sin_port == htons ( BOOTPS_PORT ) &&
+ msgtype == DHCPOFFER ) {
+ dhcp_rx_offer ( dhcp, dhcppkt, peer, msgtype, server_id );
+ return;
+ }
+
+ DBGC ( dhcp, "DHCP %p %s from %s:%d", dhcp,
+ dhcp_msgtype_name ( msgtype ), inet_ntoa ( peer->sin_addr ),
+ ntohs ( peer->sin_port ) );
+ if ( server_id.s_addr != peer->sin_addr.s_addr )
+ DBGC ( dhcp, " (%s)", inet_ntoa ( server_id ) );
+ DBGC ( dhcp, "\n" );
+
+ /* Filter out unacceptable responses */
+ if ( peer->sin_port != htons ( PXE_PORT ) )
+ return;
+ if ( msgtype != DHCPACK && msgtype != DHCPOFFER )
+ return;
+ if ( server_id.s_addr /* Linux PXE server omits server ID */ &&
+ ( server_id.s_addr != dhcp->current_offer->server.s_addr ) )
+ return;
+
+ /* Register settings */
+ dhcppkt->settings.name = PROXYDHCP_SETTINGS_NAME;
+ if ( ( rc = register_settings ( &dhcppkt->settings, NULL ) ) != 0 ) {
+ DBGC ( dhcp, "DHCP %p could not register settings: %s\n",
+ dhcp, strerror ( rc ) );
+ dhcp_finished ( dhcp, rc );
+ return;
+ }
+
+ /* Terminate DHCP */
+ dhcp_finished ( dhcp, 0 );
+}
+
+/**
+ * Handle timer expiry during ProxyDHCP request
+ *
+ * @v dhcp DHCP session
+ */
+static void dhcp_proxy_expired ( struct dhcp_session *dhcp ) {
+ unsigned long elapsed = ( currticks() - dhcp->start );
+
+ /* Give up waiting for ProxyDHCP before we reach the failure point */
+ if ( elapsed > PROXYDHCP_MAX_TIMEOUT ) {
+
+ /* Mark failed offer as unsuitable for ProxyDHCP */
+ dhcp->current_offer->valid &= ~DHCP_OFFER_PXE;
+
+ /* Prefer not to use only half of a PXE+IP offer if we
+ * have other offers available
+ */
+ dhcp->current_offer->priority = -1;
+
+ /* If we have any other PXE offers we can try, go back
+ * to DHCPREQUEST (since they might not be proxied
+ * offers, or might be coupled to a new IP address).
+ * We should probably DHCPRELEASE our old IP, but the
+ * standard does not require it.
+ */
+ if ( dhcp_next_offer ( dhcp, DHCP_OFFER_PXE ) ) {
+ dhcp->local.sin_addr.s_addr = 0;
+ dhcp_set_state ( dhcp, &dhcp_state_request );
+ return;
+ }
+
+ /* No possibilities left; finish without PXE options */
+ dhcp_finished ( dhcp, 0 );
+ return;
+ }
+
+ /* Retransmit current packet */
+ dhcp_tx ( dhcp );
+}
+
+/** ProxyDHCP request state operations */
+static struct dhcp_session_state dhcp_state_proxy = {
+ .name = "ProxyDHCP",
+ .tx = dhcp_proxy_tx,
+ .rx = dhcp_proxy_rx,
+ .expired = dhcp_proxy_expired,
+ .tx_msgtype = DHCPREQUEST,
+ .apply_min_timeout = 0,
+};
+
+/**
+ * Construct transmitted packet for PXE Boot Server Discovery
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer Destination address
+ */
+static int dhcp_pxebs_tx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer ) {
+ struct dhcp_pxe_boot_menu_item menu_item = { 0, 0 };
+ int rc;
+
+ /* Set server address */
+ peer->sin_addr = *(dhcp->pxe_attempt);
+ peer->sin_port = ( ( peer->sin_addr.s_addr == INADDR_BROADCAST ) ?
+ htons ( BOOTPS_PORT ) : htons ( PXE_PORT ) );
+
+ DBGC ( dhcp, "DHCP %p PXEBS REQUEST to %s:%d for type %d\n",
+ dhcp, inet_ntoa ( peer->sin_addr ), ntohs ( peer->sin_port ),
+ le16_to_cpu ( dhcp->pxe_type ) );
+
+ /* Set boot menu item */
+ menu_item.type = dhcp->pxe_type;
+ if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_PXE_BOOT_MENU_ITEM,
+ &menu_item, sizeof ( menu_item ) ) ) != 0 )
+ return rc;
+
+ return 0;
+}
+
+/**
+ * Check to see if PXE Boot Server address is acceptable
+ *
+ * @v dhcp DHCP session
+ * @v bs Boot Server address
+ * @ret accept Boot Server is acceptable
+ */
+static int dhcp_pxebs_accept ( struct dhcp_session *dhcp,
+ struct in_addr bs ) {
+ struct in_addr *accept;
+
+ /* Accept if we have no acceptance filter */
+ if ( ! dhcp->pxe_accept )
+ return 1;
+
+ /* Scan through acceptance list */
+ for ( accept = dhcp->pxe_accept ; accept->s_addr ; accept++ ) {
+ if ( accept->s_addr == bs.s_addr )
+ return 1;
+ }
+
+ DBGC ( dhcp, "DHCP %p rejecting server %s\n",
+ dhcp, inet_ntoa ( bs ) );
+ return 0;
+}
+
+/**
+ * Handle received packet during PXE Boot Server Discovery
+ *
+ * @v dhcp DHCP session
+ * @v dhcppkt DHCP packet
+ * @v peer DHCP server address
+ * @v msgtype DHCP message type
+ * @v server_id DHCP server ID
+ */
+static void dhcp_pxebs_rx ( struct dhcp_session *dhcp,
+ struct dhcp_packet *dhcppkt,
+ struct sockaddr_in *peer, uint8_t msgtype,
+ struct in_addr server_id ) {
+ struct dhcp_pxe_boot_menu_item menu_item = { 0, 0 };
+ int rc;
+
+ DBGC ( dhcp, "DHCP %p %s from %s:%d", dhcp,
+ dhcp_msgtype_name ( msgtype ), inet_ntoa ( peer->sin_addr ),
+ ntohs ( peer->sin_port ) );
+ if ( server_id.s_addr != peer->sin_addr.s_addr )
+ DBGC ( dhcp, " (%s)", inet_ntoa ( server_id ) );
+
+ /* Identify boot menu item */
+ dhcppkt_fetch ( dhcppkt, DHCP_PXE_BOOT_MENU_ITEM,
+ &menu_item, sizeof ( menu_item ) );
+ if ( menu_item.type )
+ DBGC ( dhcp, " for type %d", ntohs ( menu_item.type ) );
+ DBGC ( dhcp, "\n" );
+
+ /* Filter out unacceptable responses */
+ if ( ( peer->sin_port != htons ( BOOTPS_PORT ) ) &&
+ ( peer->sin_port != htons ( PXE_PORT ) ) )
+ return;
+ if ( msgtype != DHCPACK )
+ return;
+ if ( menu_item.type != dhcp->pxe_type )
+ return;
+ if ( ! dhcp_pxebs_accept ( dhcp, ( server_id.s_addr ?
+ server_id : peer->sin_addr ) ) )
+ return;
+
+ /* Register settings */
+ dhcppkt->settings.name = PXEBS_SETTINGS_NAME;
+ if ( ( rc = register_settings ( &dhcppkt->settings, NULL ) ) != 0 ) {
+ DBGC ( dhcp, "DHCP %p could not register settings: %s\n",
+ dhcp, strerror ( rc ) );
+ dhcp_finished ( dhcp, rc );
+ return;
+ }
+
+ /* Terminate DHCP */
+ dhcp_finished ( dhcp, 0 );
+}
+
+/**
+ * Handle timer expiry during PXE Boot Server Discovery
+ *
+ * @v dhcp DHCP session
+ */
+static void dhcp_pxebs_expired ( struct dhcp_session *dhcp ) {
+ unsigned long elapsed = ( currticks() - dhcp->start );
+
+ /* Give up waiting before we reach the failure point, and fail
+ * over to the next server in the attempt list
+ */
+ if ( elapsed > PXEBS_MAX_TIMEOUT ) {
+ dhcp->pxe_attempt++;
+ if ( dhcp->pxe_attempt->s_addr ) {
+ dhcp_set_state ( dhcp, &dhcp_state_pxebs );
+ return;
+ } else {
+ dhcp_finished ( dhcp, -ETIMEDOUT );
+ return;
+ }
+ }
+
+ /* Retransmit current packet */
+ dhcp_tx ( dhcp );
+}
+
+/** PXE Boot Server Discovery state operations */
+static struct dhcp_session_state dhcp_state_pxebs = {
+ .name = "PXEBS",
+ .tx = dhcp_pxebs_tx,
+ .rx = dhcp_pxebs_rx,
+ .expired = dhcp_pxebs_expired,
+ .tx_msgtype = DHCPREQUEST,
+ .apply_min_timeout = 1,
+};
+
+/****************************************************************************
+ *
+ * Packet construction
+ *
+ */
+
+/**
+ * Construct DHCP client hardware address field and broadcast flag
+ *
+ * @v netdev Network device
+ * @v hlen DHCP hardware address length to fill in
+ * @v flags DHCP flags to fill in
+ * @ret chaddr DHCP client hardware address
+ */
+void * dhcp_chaddr ( struct net_device *netdev, uint8_t *hlen,
+ uint16_t *flags ) {
+ struct ll_protocol *ll_protocol = netdev->ll_protocol;
+ typeof ( ( ( struct dhcphdr * ) NULL )->chaddr ) chaddr;
+
+ /* If the link-layer address cannot fit into the chaddr field
+ * (as is the case for IPoIB) then try using the hardware
+ * address instead. If we do this, set the broadcast flag,
+ * since chaddr then does not represent a valid link-layer
+ * address for the return path.
+ *
+ * If even the hardware address is too large, use an empty
+ * chaddr field and set the broadcast flag.
+ *
+ * This goes against RFC4390, but RFC4390 mandates that we use
+ * a DHCP client identifier that conforms with RFC4361, which
+ * we cannot do without either persistent (NIC-independent)
+ * storage, or by eliminating the hardware address completely
+ * from the DHCP packet, which seems unfriendly to users.
+ */
+ if ( ( *hlen = ll_protocol->ll_addr_len ) <= sizeof ( chaddr ) ) {
+ return netdev->ll_addr;
+ }
+ *flags = htons ( BOOTP_FL_BROADCAST );
+ if ( ( *hlen = ll_protocol->hw_addr_len ) <= sizeof ( chaddr ) ) {
+ return netdev->hw_addr;
+ } else {
+ *hlen = 0;
+ return NULL;
+ }
+}
+
+/**
+ * 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 options_len Length of initial options
+ * @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 initialise a
+ * DHCP packet structure.
+ */
+int dhcp_create_packet ( struct dhcp_packet *dhcppkt,
+ struct net_device *netdev, uint8_t msgtype,
+ const void *options, size_t options_len,
+ void *data, size_t max_len ) {
+ struct dhcphdr *dhcphdr = data;
+ void *chaddr;
+ int rc;
+
+ /* Sanity check */
+ 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];
+ chaddr = dhcp_chaddr ( netdev, &dhcphdr->hlen, &dhcphdr->flags );
+ memcpy ( dhcphdr->chaddr, chaddr, dhcphdr->hlen );
+ memcpy ( dhcphdr->options, options, 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 msgtype DHCP message type
+ * @v ciaddr Client IP address
+ * @v data Buffer for DHCP packet
+ * @v max_len Size of DHCP packet buffer
+ * @ret rc Return status code
+ *
+ * Creates a DHCP request packet in the specified buffer, and
+ * initialise a DHCP packet structure.
+ */
+int dhcp_create_request ( struct dhcp_packet *dhcppkt,
+ struct net_device *netdev, unsigned int msgtype,
+ struct in_addr ciaddr, void *data, size_t max_len ) {
+ struct dhcp_netdev_desc dhcp_desc;
+ struct dhcp_client_id client_id;
+ struct dhcp_client_uuid client_uuid;
+ uint8_t *dhcp_features;
+ size_t dhcp_features_len;
+ size_t ll_addr_len;
+ ssize_t len;
+ int rc;
+
+ /* Create DHCP packet */
+ if ( ( rc = dhcp_create_packet ( dhcppkt, netdev, msgtype,
+ dhcp_request_options_data,
+ sizeof ( dhcp_request_options_data ),
+ 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;
+
+ /* Add options to identify the feature list */
+ dhcp_features = table_start ( DHCP_FEATURES );
+ dhcp_features_len = table_num_entries ( 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 */
+ fetch_setting ( &netdev->settings.settings, &busid_setting, &dhcp_desc,
+ sizeof ( dhcp_desc ) );
+ 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 ( ( len = 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;
+ }
+ }
+
+ /* Add user class, if we have one. */
+ if ( ( len = fetch_setting_len ( NULL, &user_class_setting ) ) >= 0 ) {
+ char user_class[len];
+ fetch_setting ( NULL, &user_class_setting, user_class,
+ sizeof ( user_class ) );
+ if ( ( rc = dhcppkt_store ( dhcppkt, DHCP_USER_CLASS_ID,
+ &user_class,
+ sizeof ( user_class ) ) ) != 0 ) {
+ DBG ( "DHCP could not set user class: %s\n",
+ strerror ( rc ) );
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+/****************************************************************************
+ *
+ * Data transfer interface
+ *
+ */
+
+/**
+ * Transmit DHCP request
+ *
+ * @v dhcp DHCP session
+ * @ret rc Return status code
+ */
+static int dhcp_tx ( struct dhcp_session *dhcp ) {
+ static struct sockaddr_in peer = {
+ .sin_family = AF_INET,
+ };
+ struct xfer_metadata meta = {
+ .netdev = dhcp->netdev,
+ .src = ( struct sockaddr * ) &dhcp->local,
+ .dest = ( struct sockaddr * ) &peer,
+ };
+ struct io_buffer *iobuf;
+ uint8_t msgtype = dhcp->state->tx_msgtype;
+ struct dhcp_packet dhcppkt;
+ int rc;
+
+ /* 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 basic DHCP packet in temporary buffer */
+ if ( ( rc = dhcp_create_request ( &dhcppkt, dhcp->netdev, msgtype,
+ dhcp->local.sin_addr, iobuf->data,
+ iob_tailroom ( iobuf ) ) ) != 0 ) {
+ DBGC ( dhcp, "DHCP %p could not construct DHCP request: %s\n",
+ dhcp, strerror ( rc ) );
+ goto done;
+ }
+
+ /* Fill in packet based on current state */
+ if ( ( rc = dhcp->state->tx ( dhcp, &dhcppkt, &peer ) ) != 0 ) {
+ DBGC ( dhcp, "DHCP %p could not fill DHCP request: %s\n",
+ dhcp, strerror ( rc ) );
+ goto done;
+ }
+
+ /* Transmit the packet */
+ iob_put ( iobuf, dhcppkt.len );
+ if ( ( rc = xfer_deliver_iob_meta ( &dhcp->xfer, iob_disown ( iobuf ),
+ &meta ) ) != 0 ) {
+ DBGC ( dhcp, "DHCP %p could not transmit UDP packet: %s\n",
+ dhcp, strerror ( rc ) );
+ goto done;
+ }
+
+ done:
+ free_iob ( iobuf );
+ return rc;
+}
+
+/**
+ * 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_in *peer;
+ size_t data_len;
+ struct dhcp_packet *dhcppkt;
+ struct dhcphdr *dhcphdr;
+ uint8_t msgtype = 0;
+ struct in_addr server_id = { 0 };
+ int rc = 0;
+
+ /* Sanity checks */
+ if ( ! meta->src ) {
+ DBGC ( dhcp, "DHCP %p received packet without source port\n",
+ dhcp );
+ rc = -EINVAL;
+ goto err_no_src;
+ }
+ peer = ( struct sockaddr_in * ) meta->src;
+
+ /* Create a DHCP packet containing the I/O buffer contents.
+ * Whilst we could just use the original buffer in situ, that
+ * would waste the unused space in the packet buffer, and also
+ * waste a relatively scarce fully-aligned I/O buffer.
+ */
+ data_len = iob_len ( iobuf );
+ dhcppkt = zalloc ( sizeof ( *dhcppkt ) + data_len );
+ if ( ! dhcppkt ) {
+ rc = -ENOMEM;
+ goto err_alloc_dhcppkt;
+ }
+ dhcphdr = ( ( ( void * ) dhcppkt ) + sizeof ( *dhcppkt ) );
+ memcpy ( dhcphdr, iobuf->data, data_len );
+ dhcppkt_init ( dhcppkt, dhcphdr, data_len );
+
+ /* Identify message type */
+ dhcppkt_fetch ( dhcppkt, DHCP_MESSAGE_TYPE, &msgtype,
+ sizeof ( msgtype ) );
+
+ /* Identify server ID */
+ dhcppkt_fetch ( dhcppkt, DHCP_SERVER_IDENTIFIER,
+ &server_id, sizeof ( server_id ) );
+
+ /* Check for matching transaction ID */
+ if ( dhcphdr->xid != dhcp_xid ( dhcp->netdev ) ) {
+ DBGC ( dhcp, "DHCP %p %s from %s:%d has bad transaction "
+ "ID\n", dhcp, dhcp_msgtype_name ( msgtype ),
+ inet_ntoa ( peer->sin_addr ),
+ ntohs ( peer->sin_port ) );
+ rc = -EINVAL;
+ goto err_xid;
+ };
+
+ /* Handle packet based on current state */
+ dhcp->state->rx ( dhcp, dhcppkt, peer, msgtype, server_id );
+
+ err_xid:
+ dhcppkt_put ( dhcppkt );
+ err_alloc_dhcppkt:
+ err_no_src:
+ free_iob ( iobuf );
+ return rc;
+}
+
+/** DHCP data transfer interface operations */
+static struct xfer_interface_operations dhcp_xfer_operations = {
+ .close = ignore_xfer_close,
+ .vredirect = xfer_vreopen,
+ .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 );
+
+ /* If we have failed, terminate DHCP */
+ if ( fail ) {
+ dhcp_finished ( dhcp, -ETIMEDOUT );
+ return;
+ }
+
+ /* Handle timer expiry based on current state */
+ dhcp->state->expired ( 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,
+};
+
+/****************************************************************************
+ *
+ * Instantiators
+ *
+ */
+
+/**
+ * DHCP peer address for socket opening
+ *
+ * This is a dummy address; the only useful portion is the socket
+ * family (so that we get a UDP connection). The DHCP client will set
+ * the IP address and source port explicitly on each transmission.
+ */
+static struct sockaddr dhcp_peer = {
+ .sa_family = AF_INET,
+};
+
+/**
+ * Start DHCP state machine on a network device
+ *
+ * @v job Job control interface
+ * @v netdev Network device
+ * @ret rc Return status code, or positive if cached
+ *
+ * Starts DHCP on the specified network device. If successful, the
+ * DHCPACK (and ProxyDHCPACK, if applicable) will be registered as
+ * option sources.
+ *
+ * On a return of 0, a background job has been started to perform the
+ * DHCP request. Any nonzero return means the job has not been
+ * started; a positive return value indicates the success condition of
+ * having fetched the appropriate data from cached information.
+ */
+int start_dhcp ( struct job_interface *job, struct net_device *netdev ) {
+ struct dhcp_session *dhcp;
+ int rc;
+
+ /* Check for cached DHCP information */
+ get_cached_dhcpack();
+ if ( fetch_uintz_setting ( NULL, &use_cached_setting ) ) {
+ DBG ( "DHCP using cached network settings\n" );
+ return 1;
+ }
+
+ /* 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->local.sin_family = AF_INET;
+ dhcp->local.sin_port = htons ( BOOTPC_PORT );
+ dhcp->timer.expired = dhcp_timer_expired;
+
+ /* Instantiate child objects and attach to our interfaces */
+ if ( ( rc = xfer_open_socket ( &dhcp->xfer, SOCK_DGRAM, &dhcp_peer,
+ ( struct sockaddr * ) &dhcp->local ) ) != 0 )
+ goto err;
+
+ /* Enter DHCPDISCOVER state */
+ dhcp_set_state ( dhcp, &dhcp_state_discover );
+
+ /* 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;
+}
+
+/**
+ * Retrieve list of PXE boot servers for a given server type
+ *
+ * @v dhcp DHCP session
+ * @v raw DHCP PXE boot server list
+ * @v raw_len Length of DHCP PXE boot server list
+ * @v ip IP address list to fill in
+ *
+ * The caller must ensure that the IP address list has sufficient
+ * space.
+ */
+static void pxebs_list ( struct dhcp_session *dhcp, void *raw,
+ size_t raw_len, struct in_addr *ip ) {
+ struct dhcp_pxe_boot_server *server = raw;
+ size_t server_len;
+ unsigned int i;
+
+ while ( raw_len ) {
+ if ( raw_len < sizeof ( *server ) ) {
+ DBGC ( dhcp, "DHCP %p malformed PXE server list\n",
+ dhcp );
+ break;
+ }
+ server_len = offsetof ( typeof ( *server ),
+ ip[ server->num_ip ] );
+ if ( raw_len < server_len ) {
+ DBGC ( dhcp, "DHCP %p malformed PXE server list\n",
+ dhcp );
+ break;
+ }
+ if ( server->type == dhcp->pxe_type ) {
+ for ( i = 0 ; i < server->num_ip ; i++ )
+ *(ip++) = server->ip[i];
+ }
+ server = ( ( ( void * ) server ) + server_len );
+ raw_len -= server_len;
+ }
+}
+
+/**
+ * Start PXE Boot Server Discovery on a network device
+ *
+ * @v job Job control interface
+ * @v netdev Network device
+ * @v pxe_type PXE server type
+ * @ret rc Return status code
+ *
+ * Starts PXE Boot Server Discovery on the specified network device.
+ * If successful, the Boot Server ACK will be registered as an option
+ * source.
+ */
+int start_pxebs ( struct job_interface *job, struct net_device *netdev,
+ unsigned int pxe_type ) {
+ struct setting pxe_discovery_control_setting =
+ { .tag = DHCP_PXE_DISCOVERY_CONTROL };
+ struct setting pxe_boot_servers_setting =
+ { .tag = DHCP_PXE_BOOT_SERVERS };
+ struct setting pxe_boot_server_mcast_setting =
+ { .tag = DHCP_PXE_BOOT_SERVER_MCAST };
+ ssize_t pxebs_list_len;
+ struct dhcp_session *dhcp;
+ struct in_addr *ip;
+ unsigned int pxe_discovery_control;
+ int rc;
+
+ /* Get upper bound for PXE boot server IP address list */
+ pxebs_list_len = fetch_setting_len ( NULL, &pxe_boot_servers_setting );
+ if ( pxebs_list_len < 0 )
+ pxebs_list_len = 0;
+
+ /* Allocate and initialise structure */
+ dhcp = zalloc ( sizeof ( *dhcp ) + sizeof ( *ip ) /* mcast */ +
+ sizeof ( *ip ) /* bcast */ + pxebs_list_len +
+ sizeof ( *ip ) /* terminator */ );
+ 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->local.sin_family = AF_INET;
+ fetch_ipv4_setting ( netdev_settings ( netdev ), &ip_setting,
+ &dhcp->local.sin_addr );
+ dhcp->local.sin_port = htons ( BOOTPC_PORT );
+ dhcp->pxe_type = cpu_to_le16 ( pxe_type );
+ dhcp->timer.expired = dhcp_timer_expired;
+
+ /* Construct PXE boot server IP address lists */
+ pxe_discovery_control =
+ fetch_uintz_setting ( NULL, &pxe_discovery_control_setting );
+ ip = ( ( ( void * ) dhcp ) + sizeof ( *dhcp ) );
+ dhcp->pxe_attempt = ip;
+ if ( ! ( pxe_discovery_control & PXEBS_NO_MULTICAST ) ) {
+ fetch_ipv4_setting ( NULL, &pxe_boot_server_mcast_setting, ip);
+ if ( ip->s_addr )
+ ip++;
+ }
+ if ( ! ( pxe_discovery_control & PXEBS_NO_BROADCAST ) )
+ (ip++)->s_addr = INADDR_BROADCAST;
+ if ( pxe_discovery_control & PXEBS_NO_UNKNOWN_SERVERS )
+ dhcp->pxe_accept = ip;
+ if ( pxebs_list_len ) {
+ uint8_t buf[pxebs_list_len];
+
+ fetch_setting ( NULL, &pxe_boot_servers_setting,
+ buf, sizeof ( buf ) );
+ pxebs_list ( dhcp, buf, sizeof ( buf ), ip );
+ }
+ if ( ! dhcp->pxe_attempt->s_addr ) {
+ DBGC ( dhcp, "DHCP %p has no PXE boot servers for type %04x\n",
+ dhcp, pxe_type );
+ rc = -EINVAL;
+ goto err;
+ }
+
+ /* Dump out PXE server lists */
+ DBGC ( dhcp, "DHCP %p attempting", dhcp );
+ for ( ip = dhcp->pxe_attempt ; ip->s_addr ; ip++ )
+ DBGC ( dhcp, " %s", inet_ntoa ( *ip ) );
+ DBGC ( dhcp, "\n" );
+ if ( dhcp->pxe_accept ) {
+ DBGC ( dhcp, "DHCP %p accepting", dhcp );
+ for ( ip = dhcp->pxe_accept ; ip->s_addr ; ip++ )
+ DBGC ( dhcp, " %s", inet_ntoa ( *ip ) );
+ DBGC ( dhcp, "\n" );
+ }
+
+ /* Instantiate child objects and attach to our interfaces */
+ if ( ( rc = xfer_open_socket ( &dhcp->xfer, SOCK_DGRAM, &dhcp_peer,
+ ( struct sockaddr * ) &dhcp->local ) ) != 0 )
+ goto err;
+
+ /* Enter PXEBS state */
+ dhcp_set_state ( dhcp, &dhcp_state_pxebs );
+
+ /* 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;
+}