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Now successfully negotiates the whole DHCPDISCOVER/OFFER/REQUEST/ACK 

cycle.  :)
This commit is contained in:
Michael Brown 2006-07-20 02:19:06 +00:00
parent 30d9bcdc6e
commit 7ca1bb0fbe
2 changed files with 170 additions and 43 deletions
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16
src/include/gpxe/dhcp.h
View File

@ -12,6 +12,7 @@
#include <gpxe/in.h>
#include <gpxe/udp.h>
#include <gpxe/async.h>
#include <gpxe/retry.h>
/** BOOTP/DHCP server port */
#define BOOTPS_PORT 67
@ -407,6 +408,14 @@ struct dhcp_session {
/** UDP connection for this session */
struct udp_connection udp;
/** Network device being configured */
struct net_device *netdev;
/** Options obtained from server */
struct dhcp_option_block *options;
/** Transaction ID, in network-endian order */
uint32_t xid;
/** State of the session
*
* This is a value for the @c DHCP_MESSAGE_TYPE option
@ -415,11 +424,8 @@ struct dhcp_session {
int state;
/** Asynchronous operation for this DHCP session */
struct async_operation aop;
/** Network device being configured */
struct net_device *netdev;
/** Transaction ID, in network-endian order */
uint32_t xid;
/** Retransmission timer */
struct retry_timer timer;
};
extern unsigned long dhcp_num_option ( struct dhcp_option *option );

197
src/net/udp/dhcp.c
View File

@ -109,7 +109,7 @@ 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;
struct dhcp_option_block *options = dhcppkt->options;
struct dhcp_option *option = NULL;
/* Special-case the magic options */
@ -123,14 +123,22 @@ static int set_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
case DHCP_EB_SIADDR:
memcpy ( &dhcphdr->siaddr, data, sizeof ( dhcphdr->siaddr ) );
return 0;
case DHCP_MESSAGE_TYPE:
case DHCP_REQUESTED_ADDRESS:
/* These options have to be within the main options
* block. This doesn't seem to be required by the
* RFCs, but at least ISC dhcpd refuses to recognise
* them otherwise.
*/
options = &dhcppkt->options[OPTS_MAIN];
break;
default:
/* Continue processing as normal */
break;
}
/* Set option in first available options block */
for ( options = dhcppkt->options ;
options < &dhcppkt->options[NUM_OPT_BLOCKS] ; options++ ) {
for ( ; options < &dhcppkt->options[NUM_OPT_BLOCKS] ; options++ ) {
option = set_dhcp_option ( options, tag, data, len );
if ( option )
break;
@ -144,7 +152,40 @@ static int set_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
}
/**
* Set options within DHCP packet
* 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
@ -158,12 +199,11 @@ static int set_dhcp_packet_option ( struct dhcp_packet *dhcppkt,
* @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 set_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options,
unsigned int encapsulator ) {
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;
struct dhcp_option *option;
int rc;
for ( subtag = DHCP_MIN_OPTION; subtag <= DHCP_MAX_OPTION; subtag++ ) {
@ -172,19 +212,15 @@ static int set_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
case DHCP_EB_ENCAP:
case DHCP_VENDOR_ENCAP:
/* Process encapsulated options field */
if ( ( rc = set_dhcp_packet_encap_options ( dhcppkt,
options,
tag )) !=0)
if ( ( rc = copy_dhcp_packet_encap_options ( dhcppkt,
options,
tag)) !=0)
return rc;
break;
default:
/* Copy option to reassembled packet */
option = find_dhcp_option ( options, tag );
if ( ! option )
break;
if ( ( rc = set_dhcp_packet_option ( dhcppkt, tag,
&option->data,
option->len)) !=0)
if ( ( rc = copy_dhcp_packet_option ( dhcppkt, options,
tag, tag ) ) !=0)
return rc;
break;
};
@ -194,7 +230,7 @@ static int set_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
}
/**
* Set options within DHCP packet
* Copy options into DHCP packet
*
* @v dhcppkt DHCP packet
* @v options DHCP option block, or NULL
@ -207,9 +243,9 @@ static int set_dhcp_packet_encap_options ( struct dhcp_packet *dhcppkt,
* @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 set_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options ) {
return set_dhcp_packet_encap_options ( dhcppkt, options, 0 );
static int copy_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
struct dhcp_option_block *options ) {
return copy_dhcp_packet_encap_options ( dhcppkt, options, 0 );
}
/**
@ -224,7 +260,7 @@ static int set_dhcp_packet_options ( struct dhcp_packet *dhcppkt,
*
* 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 set_dhcp_packet_options().
* set_dhcp_packet_option() or copy_dhcp_packet_options().
*/
static int create_dhcp_packet ( struct dhcp_session *dhcp, uint8_t msgtype,
void *data, size_t max_len,
@ -232,6 +268,7 @@ static int create_dhcp_packet ( struct dhcp_session *dhcp, uint8_t msgtype,
struct dhcphdr *dhcphdr = data;
static const uint8_t overloading = ( DHCP_OPTION_OVERLOAD_FILE |
DHCP_OPTION_OVERLOAD_SNAME );
int rc;
/* Sanity check */
if ( max_len < sizeof ( *dhcphdr ) )
@ -263,14 +300,11 @@ static int create_dhcp_packet ( struct dhcp_session *dhcp, uint8_t msgtype,
sizeof ( overloading ) ) == NULL )
return -ENOSPC;
/* Set DHCP_MESSAGE_TYPE option within the main options block.
* This doesn't seem to be required by the RFCs, but at least
* ISC dhcpd and ethereal refuse to recognise it otherwise.
*/
if ( set_dhcp_option ( &dhcppkt->options[OPTS_MAIN],
DHCP_MESSAGE_TYPE, &msgtype,
sizeof ( msgtype ) ) == NULL )
return -ENOSPC;
/* Set DHCP_MESSAGE_TYPE option */
if ( ( rc = set_dhcp_packet_option ( dhcppkt, DHCP_MESSAGE_TYPE,
&msgtype,
sizeof ( msgtype ) ) ) != 0 )
return rc;
return 0;
}
@ -435,6 +469,17 @@ udp_to_dhcp ( struct udp_connection *conn ) {
return container_of ( conn, struct dhcp_session, udp );
}
/**
* Mark DHCP session as complete
*
* @v dhcp DHCP session
* @v rc Return status code
*/
static void dhcp_done ( struct dhcp_session *dhcp, int rc ) {
/* Mark async operation as complete */
async_done ( &dhcp->aop, rc );
}
/** Address for transmitting DHCP requests */
static struct sockaddr sa_dhcp_server = {
.sa_family = AF_INET,
@ -470,12 +515,28 @@ static void dhcp_senddata ( struct udp_connection *conn,
}
/* Copy in options common to all requests */
if ( ( rc = set_dhcp_packet_options ( &dhcppkt,
&dhcp_request_options ) ) != 0 ){
if ( ( rc = copy_dhcp_packet_options ( &dhcppkt,
&dhcp_request_options ) ) != 0){
DBG ( "Could not set common DHCP options\n" );
return;
}
/* Copy any required options from previous server repsonse */
if ( dhcp->options ) {
if ( ( rc = copy_dhcp_packet_option ( &dhcppkt, dhcp->options,
DHCP_SERVER_IDENTIFIER,
DHCP_SERVER_IDENTIFIER ) ) != 0 ) {
DBG ( "Could not set server identifier option\n" );
return;
}
if ( ( rc = copy_dhcp_packet_option ( &dhcppkt, dhcp->options,
DHCP_EB_YIADDR,
DHCP_REQUESTED_ADDRESS ) ) != 0 ) {
DBG ( "Could not set requested address option\n" );
return;
}
}
/* Transmit the packet */
if ( ( rc = udp_sendto ( conn, &sa_dhcp_server,
dhcppkt.dhcphdr, dhcppkt.len ) ) != 0 ) {
@ -484,6 +545,33 @@ static void dhcp_senddata ( struct udp_connection *conn,
}
}
/**
* Transmit DHCP request
*
* @v dhcp DHCP session
*/
static void dhcp_send_request ( struct dhcp_session *dhcp ) {
start_timer ( &dhcp->timer );
udp_senddata ( &dhcp->udp );
}
/**
* 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_done ( dhcp, -ETIMEDOUT );
} else {
dhcp_send_request ( dhcp );
}
}
/**
* Receive new data
*
@ -496,6 +584,7 @@ static void dhcp_newdata ( struct udp_connection *conn,
struct dhcp_session *dhcp = udp_to_dhcp ( conn );
struct dhcphdr *dhcphdr = data;
struct dhcp_option_block *options;
unsigned int msgtype;
/* Check for matching transaction ID */
if ( dhcphdr->xid != dhcp->xid ) {
@ -511,12 +600,42 @@ static void dhcp_newdata ( struct udp_connection *conn,
return;
}
DBG ( "Received %s\n",
dhcp_msgtype_name ( find_dhcp_num_option ( options,
DHCP_MESSAGE_TYPE )));
/* Determine message type */
msgtype = find_dhcp_num_option ( options, DHCP_MESSAGE_TYPE );
DBG ( "Received %s\n", dhcp_msgtype_name ( msgtype ) );
/* Proof of concept: just dump out the parsed options */
hex_dump ( options->data, options->len );
/* Handle DHCP reply */
switch ( dhcp->state ) {
case DHCPDISCOVER:
if ( msgtype != DHCPOFFER )
goto out_discard;
dhcp->state = DHCPREQUEST;
break;
case DHCPREQUEST:
if ( msgtype != DHCPACK )
goto out_discard;
dhcp->state = DHCPACK;
break;
default:
assert ( 0 );
goto out_discard;
}
/* Stop timer and update stored options */
stop_timer ( &dhcp->timer );
if ( dhcp->options )
free_dhcp_options ( dhcp->options );
dhcp->options = options;
/* Transmit next packet, or terminate session */
if ( dhcp->state < DHCPACK ) {
dhcp_send_request ( dhcp );
} else {
dhcp_done ( dhcp, 0 );
}
return;
out_discard:
free_dhcp_options ( options );
}
@ -535,7 +654,9 @@ static struct udp_operations dhcp_udp_operations = {
struct async_operation * start_dhcp ( struct dhcp_session *dhcp ) {
int rc;
/* Initialise DHCP session */
dhcp->udp.udp_op = &dhcp_udp_operations;
dhcp->timer.expired = dhcp_timer_expired;
dhcp->state = DHCPDISCOVER;
/* Use least significant 32 bits of link-layer address as XID */
memcpy ( &dhcp->xid, ( dhcp->netdev->ll_addr
@ -549,7 +670,7 @@ struct async_operation * start_dhcp ( struct dhcp_session *dhcp ) {
}
/* Proof of concept: just send a single DHCPDISCOVER */
udp_senddata ( &dhcp->udp );
dhcp_send_request ( dhcp );
out:
return &dhcp->aop;