mirror of https://github.com/ipxe/ipxe.git
[peerdist] Add segment discovery mechanism
Signed-off-by: Michael Brown <mcb30@ipxe.org>pull/54/head
Michael Brown
parent
518a98eb56
commit
dc9d24e7d2
|
|
@ -14,6 +14,9 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
|
||||||
/* Drop every N transmitted or received network packets */
|
/* Drop every N transmitted or received network packets */
|
||||||
#define NETDEV_DISCARD_RATE 0
|
#define NETDEV_DISCARD_RATE 0
|
||||||
|
|
||||||
|
/* Drop every N transmitted or received PeerDist discovery packets */
|
||||||
|
#define PEERDISC_DISCARD_RATE 0
|
||||||
|
|
||||||
#include <config/local/fault.h>
|
#include <config/local/fault.h>
|
||||||
|
|
||||||
#endif /* CONFIG_FAULT_H */
|
#endif /* CONFIG_FAULT_H */
|
||||||
|
|
|
||||||
|
|
@ -252,6 +252,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
|
||||||
#define ERRFILE_httpauth ( ERRFILE_NET | 0x00420000 )
|
#define ERRFILE_httpauth ( ERRFILE_NET | 0x00420000 )
|
||||||
#define ERRFILE_httpbasic ( ERRFILE_NET | 0x00430000 )
|
#define ERRFILE_httpbasic ( ERRFILE_NET | 0x00430000 )
|
||||||
#define ERRFILE_httpdigest ( ERRFILE_NET | 0x00440000 )
|
#define ERRFILE_httpdigest ( ERRFILE_NET | 0x00440000 )
|
||||||
|
#define ERRFILE_peerdisc ( ERRFILE_NET | 0x00450000 )
|
||||||
|
|
||||||
#define ERRFILE_image ( ERRFILE_IMAGE | 0x00000000 )
|
#define ERRFILE_image ( ERRFILE_IMAGE | 0x00000000 )
|
||||||
#define ERRFILE_elf ( ERRFILE_IMAGE | 0x00010000 )
|
#define ERRFILE_elf ( ERRFILE_IMAGE | 0x00010000 )
|
||||||
|
|
|
||||||
|
|
@ -0,0 +1,116 @@
|
||||||
|
#ifndef _IPXE_PEERDISC_H
|
||||||
|
#define _IPXE_PEERDISC_H
|
||||||
|
|
||||||
|
/** @file
|
||||||
|
*
|
||||||
|
* Peer Content Caching and Retrieval (PeerDist) protocol peer discovery
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
|
||||||
|
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
|
||||||
|
|
||||||
|
#include <stdint.h>
|
||||||
|
#include <ipxe/refcnt.h>
|
||||||
|
#include <ipxe/list.h>
|
||||||
|
#include <ipxe/tables.h>
|
||||||
|
#include <ipxe/retry.h>
|
||||||
|
#include <ipxe/socket.h>
|
||||||
|
#include <ipxe/interface.h>
|
||||||
|
#include <ipxe/pccrc.h>
|
||||||
|
|
||||||
|
/** A PeerDist discovery socket */
|
||||||
|
struct peerdisc_socket {
|
||||||
|
/** Name */
|
||||||
|
const char *name;
|
||||||
|
/** Data transfer interface */
|
||||||
|
struct interface xfer;
|
||||||
|
/** Socket address */
|
||||||
|
union {
|
||||||
|
struct sockaddr sa;
|
||||||
|
struct sockaddr_in sin;
|
||||||
|
struct sockaddr_in6 sin6;
|
||||||
|
} address;
|
||||||
|
};
|
||||||
|
|
||||||
|
/** PeerDist discovery socket table */
|
||||||
|
#define PEERDISC_SOCKETS __table ( struct peerdisc_socket, "peerdisc_sockets" )
|
||||||
|
|
||||||
|
/** Declare a PeerDist discovery socket */
|
||||||
|
#define __peerdisc_socket __table_entry ( PEERDISC_SOCKETS, 01 )
|
||||||
|
|
||||||
|
/** A PeerDist discovery segment */
|
||||||
|
struct peerdisc_segment {
|
||||||
|
/** Reference count */
|
||||||
|
struct refcnt refcnt;
|
||||||
|
/** List of segments */
|
||||||
|
struct list_head list;
|
||||||
|
/** Segment identifier string
|
||||||
|
*
|
||||||
|
* This is MS-PCCRC's "HoHoDk", transcribed as an upper-case
|
||||||
|
* Base16-encoded string.
|
||||||
|
*/
|
||||||
|
const char *id;
|
||||||
|
/** Message UUID string */
|
||||||
|
const char *uuid;
|
||||||
|
/** List of discovered peers
|
||||||
|
*
|
||||||
|
* The list of peers may be appended to during the lifetime of
|
||||||
|
* the discovery segment. Discovered peers will not be
|
||||||
|
* removed from the list until the last discovery has been
|
||||||
|
* closed; this allows users to safely maintain a pointer to a
|
||||||
|
* current position within the list.
|
||||||
|
*/
|
||||||
|
struct list_head peers;
|
||||||
|
/** List of active clients */
|
||||||
|
struct list_head clients;
|
||||||
|
/** Transmission timer */
|
||||||
|
struct retry_timer timer;
|
||||||
|
};
|
||||||
|
|
||||||
|
/** A PeerDist discovery peer */
|
||||||
|
struct peerdisc_peer {
|
||||||
|
/** List of peers */
|
||||||
|
struct list_head list;
|
||||||
|
/** Peer location */
|
||||||
|
char location[0];
|
||||||
|
};
|
||||||
|
|
||||||
|
/** A PeerDist discovery client */
|
||||||
|
struct peerdisc_client {
|
||||||
|
/** Discovery segment */
|
||||||
|
struct peerdisc_segment *segment;
|
||||||
|
/** List of clients */
|
||||||
|
struct list_head list;
|
||||||
|
/** Operations */
|
||||||
|
struct peerdisc_client_operations *op;
|
||||||
|
};
|
||||||
|
|
||||||
|
/** PeerDist discovery client operations */
|
||||||
|
struct peerdisc_client_operations {
|
||||||
|
/** New peers have been discovered
|
||||||
|
*
|
||||||
|
* @v peerdisc PeerDist discovery client
|
||||||
|
*/
|
||||||
|
void ( * discovered ) ( struct peerdisc_client *peerdisc );
|
||||||
|
};
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Initialise PeerDist discovery
|
||||||
|
*
|
||||||
|
* @v peerdisc PeerDist discovery client
|
||||||
|
* @v op Discovery operations
|
||||||
|
*/
|
||||||
|
static inline __attribute__ (( always_inline )) void
|
||||||
|
peerdisc_init ( struct peerdisc_client *peerdisc,
|
||||||
|
struct peerdisc_client_operations *op ) {
|
||||||
|
|
||||||
|
peerdisc->op = op;
|
||||||
|
}
|
||||||
|
|
||||||
|
extern unsigned int peerdisc_timeout_secs;
|
||||||
|
|
||||||
|
extern int peerdisc_open ( struct peerdisc_client *peerdisc, const void *id,
|
||||||
|
size_t len );
|
||||||
|
extern void peerdisc_close ( struct peerdisc_client *peerdisc );
|
||||||
|
|
||||||
|
#endif /* _IPXE_PEERDISC_H */
|
||||||
|
|
@ -0,0 +1,551 @@
|
||||||
|
/*
|
||||||
|
* Copyright (C) 2015 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 (at your option) any later version.
|
||||||
|
*
|
||||||
|
* This program is distributed in the hope that it will be useful, but
|
||||||
|
* WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||||
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
||||||
|
* General Public License for more details.
|
||||||
|
*
|
||||||
|
* You should have received a copy of the GNU General Public License
|
||||||
|
* along with this program; if not, write to the Free Software
|
||||||
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
|
||||||
|
* 02110-1301, USA.
|
||||||
|
*
|
||||||
|
* You can also choose to distribute this program under the terms of
|
||||||
|
* the Unmodified Binary Distribution Licence (as given in the file
|
||||||
|
* COPYING.UBDL), provided that you have satisfied its requirements.
|
||||||
|
*/
|
||||||
|
|
||||||
|
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
|
||||||
|
|
||||||
|
#include <stdlib.h>
|
||||||
|
#include <string.h>
|
||||||
|
#include <ctype.h>
|
||||||
|
#include <errno.h>
|
||||||
|
#include <assert.h>
|
||||||
|
#include <ipxe/xfer.h>
|
||||||
|
#include <ipxe/iobuf.h>
|
||||||
|
#include <ipxe/open.h>
|
||||||
|
#include <ipxe/tcpip.h>
|
||||||
|
#include <ipxe/uuid.h>
|
||||||
|
#include <ipxe/base16.h>
|
||||||
|
#include <ipxe/netdevice.h>
|
||||||
|
#include <ipxe/timer.h>
|
||||||
|
#include <ipxe/fault.h>
|
||||||
|
#include <ipxe/pccrd.h>
|
||||||
|
#include <ipxe/peerdisc.h>
|
||||||
|
|
||||||
|
/** @file
|
||||||
|
*
|
||||||
|
* Peer Content Caching and Retrieval (PeerDist) protocol peer discovery
|
||||||
|
*
|
||||||
|
*/
|
||||||
|
|
||||||
|
/** List of discovery segments */
|
||||||
|
static LIST_HEAD ( peerdisc_segments );
|
||||||
|
|
||||||
|
/** Number of repeated discovery attempts */
|
||||||
|
#define PEERDISC_REPEAT_COUNT 2
|
||||||
|
|
||||||
|
/** Time between repeated discovery attempts */
|
||||||
|
#define PEERDISC_REPEAT_TIMEOUT ( 1 * TICKS_PER_SEC )
|
||||||
|
|
||||||
|
/** Default discovery timeout (in seconds) */
|
||||||
|
#define PEERDISC_DEFAULT_TIMEOUT_SECS 2
|
||||||
|
|
||||||
|
/** Recommended discovery timeout (in seconds)
|
||||||
|
*
|
||||||
|
* We reduce the recommended discovery timeout whenever a segment
|
||||||
|
* fails to discover any peers, and restore the default value whenever
|
||||||
|
* a valid discovery reply is received. We continue to send discovery
|
||||||
|
* requests even if the recommended timeout is reduced to zero.
|
||||||
|
*
|
||||||
|
* This strategy is intended to minimise discovery delays when no
|
||||||
|
* peers are available on the network, while allowing downloads to
|
||||||
|
* quickly switch back to using PeerDist acceleration if new peers
|
||||||
|
* become available.
|
||||||
|
*/
|
||||||
|
unsigned int peerdisc_timeout_secs = PEERDISC_DEFAULT_TIMEOUT_SECS;
|
||||||
|
|
||||||
|
static struct peerdisc_segment * peerdisc_find ( const char *id );
|
||||||
|
static int peerdisc_discovered ( struct peerdisc_segment *segment,
|
||||||
|
const char *location );
|
||||||
|
|
||||||
|
/******************************************************************************
|
||||||
|
*
|
||||||
|
* Discovery sockets
|
||||||
|
*
|
||||||
|
******************************************************************************
|
||||||
|
*/
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Open all PeerDist discovery sockets
|
||||||
|
*
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
static int peerdisc_socket_open ( void ) {
|
||||||
|
struct peerdisc_socket *socket;
|
||||||
|
int rc;
|
||||||
|
|
||||||
|
/* Open each socket */
|
||||||
|
for_each_table_entry ( socket, PEERDISC_SOCKETS ) {
|
||||||
|
if ( ( rc = xfer_open_socket ( &socket->xfer, SOCK_DGRAM,
|
||||||
|
&socket->address.sa,
|
||||||
|
NULL ) ) != 0 ) {
|
||||||
|
DBGC ( socket, "PEERDISC %s could not open socket: "
|
||||||
|
"%s\n", socket->name, strerror ( rc ) );
|
||||||
|
goto err;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
|
||||||
|
err:
|
||||||
|
for_each_table_entry_continue_reverse ( socket, PEERDISC_SOCKETS )
|
||||||
|
intf_restart ( &socket->xfer, rc );
|
||||||
|
return rc;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Attempt to transmit PeerDist discovery requests on all sockets
|
||||||
|
*
|
||||||
|
* @v uuid Message UUID string
|
||||||
|
* @v id Segment identifier string
|
||||||
|
*/
|
||||||
|
static void peerdisc_socket_tx ( const char *uuid, const char *id ) {
|
||||||
|
struct peerdisc_socket *socket;
|
||||||
|
struct net_device *netdev;
|
||||||
|
struct xfer_metadata meta;
|
||||||
|
union {
|
||||||
|
struct sockaddr sa;
|
||||||
|
struct sockaddr_tcpip st;
|
||||||
|
} address;
|
||||||
|
char *request;
|
||||||
|
size_t len;
|
||||||
|
int rc;
|
||||||
|
|
||||||
|
/* Construct discovery request */
|
||||||
|
request = peerdist_discovery_request ( uuid, id );
|
||||||
|
if ( ! request )
|
||||||
|
goto err_request;
|
||||||
|
len = strlen ( request );
|
||||||
|
|
||||||
|
/* Initialise data transfer metadata */
|
||||||
|
memset ( &meta, 0, sizeof ( meta ) );
|
||||||
|
meta.dest = &address.sa;
|
||||||
|
|
||||||
|
/* Send message on each socket */
|
||||||
|
for_each_table_entry ( socket, PEERDISC_SOCKETS ) {
|
||||||
|
|
||||||
|
/* Initialise socket address */
|
||||||
|
memcpy ( &address.sa, &socket->address.sa,
|
||||||
|
sizeof ( address.sa ) );
|
||||||
|
|
||||||
|
/* Send message on each open network device */
|
||||||
|
for_each_netdev ( netdev ) {
|
||||||
|
|
||||||
|
/* Skip unopened network devices */
|
||||||
|
if ( ! netdev_is_open ( netdev ) )
|
||||||
|
continue;
|
||||||
|
address.st.st_scope_id = netdev->index;
|
||||||
|
|
||||||
|
/* Discard request (for test purposes) if applicable */
|
||||||
|
if ( inject_fault ( PEERDISC_DISCARD_RATE ) )
|
||||||
|
continue;
|
||||||
|
|
||||||
|
/* Transmit request */
|
||||||
|
if ( ( rc = xfer_deliver_raw_meta ( &socket->xfer,
|
||||||
|
request, len,
|
||||||
|
&meta ) ) != 0 ) {
|
||||||
|
DBGC ( socket, "PEERDISC %s could not transmit "
|
||||||
|
"via %s: %s\n", socket->name,
|
||||||
|
netdev->name, strerror ( rc ) );
|
||||||
|
/* Contine to try other net devices/sockets */
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
free ( request );
|
||||||
|
err_request:
|
||||||
|
return;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Handle received PeerDist discovery reply
|
||||||
|
*
|
||||||
|
* @v socket PeerDist discovery socket
|
||||||
|
* @v iobuf I/O buffer
|
||||||
|
* @v meta Data transfer metadata
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
static int peerdisc_socket_rx ( struct peerdisc_socket *socket,
|
||||||
|
struct io_buffer *iobuf,
|
||||||
|
struct xfer_metadata *meta __unused ) {
|
||||||
|
struct peerdist_discovery_reply reply;
|
||||||
|
struct peerdisc_segment *segment;
|
||||||
|
char *id;
|
||||||
|
char *location;
|
||||||
|
int rc;
|
||||||
|
|
||||||
|
/* Discard reply (for test purposes) if applicable */
|
||||||
|
if ( ( rc = inject_fault ( PEERDISC_DISCARD_RATE ) ) != 0 )
|
||||||
|
goto err;
|
||||||
|
|
||||||
|
/* Parse reply */
|
||||||
|
if ( ( rc = peerdist_discovery_reply ( iobuf->data, iob_len ( iobuf ),
|
||||||
|
&reply ) ) != 0 ) {
|
||||||
|
DBGC ( socket, "PEERDISC %s could not parse reply: %s\n",
|
||||||
|
socket->name, strerror ( rc ) );
|
||||||
|
DBGC_HDA ( socket, 0, iobuf->data, iob_len ( iobuf ) );
|
||||||
|
goto err;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Any kind of discovery reply indicates that there are active
|
||||||
|
* peers on a local network, so restore the recommended
|
||||||
|
* discovery timeout to its default value for future requests.
|
||||||
|
*/
|
||||||
|
if ( peerdisc_timeout_secs != PEERDISC_DEFAULT_TIMEOUT_SECS ) {
|
||||||
|
DBGC ( socket, "PEERDISC %s restoring timeout to %d seconds\n",
|
||||||
|
socket->name, PEERDISC_DEFAULT_TIMEOUT_SECS );
|
||||||
|
}
|
||||||
|
peerdisc_timeout_secs = PEERDISC_DEFAULT_TIMEOUT_SECS;
|
||||||
|
|
||||||
|
/* Iterate over segment IDs */
|
||||||
|
for ( id = reply.ids ; *id ; id += ( strlen ( id ) + 1 /* NUL */ ) ) {
|
||||||
|
|
||||||
|
/* Find corresponding segment */
|
||||||
|
segment = peerdisc_find ( id );
|
||||||
|
if ( ! segment ) {
|
||||||
|
DBGC ( socket, "PEERDISC %s ignoring reply for %s\n",
|
||||||
|
socket->name, id );
|
||||||
|
continue;
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Report all discovered peer locations */
|
||||||
|
for ( location = reply.locations ; *location ;
|
||||||
|
location += ( strlen ( location ) + 1 /* NUL */ ) ) {
|
||||||
|
|
||||||
|
/* Report discovered peer location */
|
||||||
|
if ( ( rc = peerdisc_discovered ( segment,
|
||||||
|
location ) ) != 0 )
|
||||||
|
goto err;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
|
||||||
|
err:
|
||||||
|
free_iob ( iobuf );
|
||||||
|
return rc;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Close all PeerDist discovery sockets
|
||||||
|
*
|
||||||
|
* @v rc Reason for close
|
||||||
|
*/
|
||||||
|
static void peerdisc_socket_close ( int rc ) {
|
||||||
|
struct peerdisc_socket *socket;
|
||||||
|
|
||||||
|
/* Close all sockets */
|
||||||
|
for_each_table_entry ( socket, PEERDISC_SOCKETS )
|
||||||
|
intf_restart ( &socket->xfer, rc );
|
||||||
|
}
|
||||||
|
|
||||||
|
/** PeerDist discovery socket interface operations */
|
||||||
|
static struct interface_operation peerdisc_socket_operations[] = {
|
||||||
|
INTF_OP ( xfer_deliver, struct peerdisc_socket *, peerdisc_socket_rx ),
|
||||||
|
};
|
||||||
|
|
||||||
|
/** PeerDist discovery socket interface descriptor */
|
||||||
|
static struct interface_descriptor peerdisc_socket_desc =
|
||||||
|
INTF_DESC ( struct peerdisc_socket, xfer, peerdisc_socket_operations );
|
||||||
|
|
||||||
|
/** PeerDist discovery IPv4 socket */
|
||||||
|
struct peerdisc_socket peerdisc_socket_ipv4 __peerdisc_socket = {
|
||||||
|
.name = "IPv4",
|
||||||
|
.address = {
|
||||||
|
.sin = {
|
||||||
|
.sin_family = AF_INET,
|
||||||
|
.sin_port = htons ( PEERDIST_DISCOVERY_PORT ),
|
||||||
|
.sin_addr.s_addr = htonl ( PEERDIST_DISCOVERY_IPV4 ),
|
||||||
|
},
|
||||||
|
},
|
||||||
|
.xfer = INTF_INIT ( peerdisc_socket_desc ),
|
||||||
|
};
|
||||||
|
|
||||||
|
/** PeerDist discovery IPv6 socket */
|
||||||
|
struct peerdisc_socket peerdisc_socket_ipv6 __peerdisc_socket = {
|
||||||
|
.name = "IPv6",
|
||||||
|
.address = {
|
||||||
|
.sin6 = {
|
||||||
|
.sin6_family = AF_INET6,
|
||||||
|
.sin6_port = htons ( PEERDIST_DISCOVERY_PORT ),
|
||||||
|
.sin6_addr.s6_addr = PEERDIST_DISCOVERY_IPV6,
|
||||||
|
},
|
||||||
|
},
|
||||||
|
.xfer = INTF_INIT ( peerdisc_socket_desc ),
|
||||||
|
};
|
||||||
|
|
||||||
|
/******************************************************************************
|
||||||
|
*
|
||||||
|
* Discovery segments
|
||||||
|
*
|
||||||
|
******************************************************************************
|
||||||
|
*/
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Free PeerDist discovery segment
|
||||||
|
*
|
||||||
|
* @v refcnt Reference count
|
||||||
|
*/
|
||||||
|
static void peerdisc_free ( struct refcnt *refcnt ) {
|
||||||
|
struct peerdisc_segment *segment =
|
||||||
|
container_of ( refcnt, struct peerdisc_segment, refcnt );
|
||||||
|
struct peerdisc_peer *peer;
|
||||||
|
struct peerdisc_peer *tmp;
|
||||||
|
|
||||||
|
/* Free all discovered peers */
|
||||||
|
list_for_each_entry_safe ( peer, tmp, &segment->peers, list ) {
|
||||||
|
list_del ( &peer->list );
|
||||||
|
free ( peer );
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Free segment */
|
||||||
|
free ( segment );
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Find PeerDist discovery segment
|
||||||
|
*
|
||||||
|
* @v id Segment ID
|
||||||
|
* @ret segment PeerDist discovery segment, or NULL if not found
|
||||||
|
*/
|
||||||
|
static struct peerdisc_segment * peerdisc_find ( const char *id ) {
|
||||||
|
struct peerdisc_segment *segment;
|
||||||
|
|
||||||
|
/* Look for a matching segment */
|
||||||
|
list_for_each_entry ( segment, &peerdisc_segments, list ) {
|
||||||
|
if ( strcmp ( id, segment->id ) == 0 )
|
||||||
|
return segment;
|
||||||
|
}
|
||||||
|
|
||||||
|
return NULL;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Add discovered PeerDist peer
|
||||||
|
*
|
||||||
|
* @v segment PeerDist discovery segment
|
||||||
|
* @v location Peer location
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
static int peerdisc_discovered ( struct peerdisc_segment *segment,
|
||||||
|
const char *location ) {
|
||||||
|
struct peerdisc_peer *peer;
|
||||||
|
struct peerdisc_client *peerdisc;
|
||||||
|
struct peerdisc_client *tmp;
|
||||||
|
|
||||||
|
/* Ignore duplicate peers */
|
||||||
|
list_for_each_entry ( peer, &segment->peers, list ) {
|
||||||
|
if ( strcmp ( peer->location, location ) == 0 ) {
|
||||||
|
DBGC2 ( segment, "PEERDISC %p duplicate %s\n",
|
||||||
|
segment, location );
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
}
|
||||||
|
DBGC2 ( segment, "PEERDISC %p discovered %s\n", segment, location );
|
||||||
|
|
||||||
|
/* Allocate and initialise structure */
|
||||||
|
peer = zalloc ( sizeof ( *peer ) + strlen ( location ) + 1 /* NUL */ );
|
||||||
|
if ( ! peer )
|
||||||
|
return -ENOMEM;
|
||||||
|
strcpy ( peer->location, location );
|
||||||
|
|
||||||
|
/* Add to end of list of peers */
|
||||||
|
list_add_tail ( &peer->list, &segment->peers );
|
||||||
|
|
||||||
|
/* Notify all clients */
|
||||||
|
list_for_each_entry_safe ( peerdisc, tmp, &segment->clients, list )
|
||||||
|
peerdisc->op->discovered ( peerdisc );
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Handle discovery timer expiry
|
||||||
|
*
|
||||||
|
* @v timer Discovery timer
|
||||||
|
* @v over Failure indicator
|
||||||
|
*/
|
||||||
|
static void peerdisc_expired ( struct retry_timer *timer, int over __unused ) {
|
||||||
|
struct peerdisc_segment *segment =
|
||||||
|
container_of ( timer, struct peerdisc_segment, timer );
|
||||||
|
|
||||||
|
/* Attempt to transmit discovery requests */
|
||||||
|
peerdisc_socket_tx ( segment->uuid, segment->id );
|
||||||
|
|
||||||
|
/* Schedule next transmission, if applicable */
|
||||||
|
if ( timer->count < PEERDISC_REPEAT_COUNT )
|
||||||
|
start_timer_fixed ( &segment->timer, PEERDISC_REPEAT_TIMEOUT );
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Create PeerDist discovery segment
|
||||||
|
*
|
||||||
|
* @v id Segment ID
|
||||||
|
* @ret segment PeerDist discovery segment, or NULL on error
|
||||||
|
*/
|
||||||
|
static struct peerdisc_segment * peerdisc_create ( const char *id ) {
|
||||||
|
struct peerdisc_segment *segment;
|
||||||
|
union {
|
||||||
|
union uuid uuid;
|
||||||
|
uint32_t dword[ sizeof ( union uuid ) / sizeof ( uint32_t ) ];
|
||||||
|
} random_uuid;
|
||||||
|
size_t uuid_len;
|
||||||
|
size_t id_len;
|
||||||
|
char *uuid;
|
||||||
|
char *uuid_copy;
|
||||||
|
char *id_copy;
|
||||||
|
unsigned int i;
|
||||||
|
|
||||||
|
/* Generate a random message UUID. This does not require high
|
||||||
|
* quality randomness.
|
||||||
|
*/
|
||||||
|
for ( i = 0 ; i < ( sizeof ( random_uuid.dword ) /
|
||||||
|
sizeof ( random_uuid.dword[0] ) ) ; i++ )
|
||||||
|
random_uuid.dword[i] = random();
|
||||||
|
uuid = uuid_ntoa ( &random_uuid.uuid );
|
||||||
|
|
||||||
|
/* Calculate string lengths */
|
||||||
|
id_len = ( strlen ( id ) + 1 /* NUL */ );
|
||||||
|
uuid_len = ( strlen ( uuid ) + 1 /* NUL */ );
|
||||||
|
|
||||||
|
/* Allocate and initialise structure */
|
||||||
|
segment = zalloc ( sizeof ( *segment ) + id_len + uuid_len );
|
||||||
|
if ( ! segment )
|
||||||
|
return NULL;
|
||||||
|
id_copy = ( ( ( void * ) segment ) + sizeof ( *segment ) );
|
||||||
|
memcpy ( id_copy, id, id_len );
|
||||||
|
uuid_copy = ( ( ( void * ) id_copy ) + id_len );
|
||||||
|
memcpy ( uuid_copy, uuid, uuid_len );
|
||||||
|
ref_init ( &segment->refcnt, peerdisc_free );
|
||||||
|
segment->id = id_copy;
|
||||||
|
segment->uuid = uuid_copy;
|
||||||
|
INIT_LIST_HEAD ( &segment->peers );
|
||||||
|
INIT_LIST_HEAD ( &segment->clients );
|
||||||
|
timer_init ( &segment->timer, peerdisc_expired, &segment->refcnt );
|
||||||
|
DBGC2 ( segment, "PEERDISC %p discovering %s\n", segment, segment->id );
|
||||||
|
|
||||||
|
/* Start discovery timer */
|
||||||
|
start_timer_nodelay ( &segment->timer );
|
||||||
|
|
||||||
|
/* Add to list of segments, transfer reference to list, and return */
|
||||||
|
list_add_tail ( &segment->list, &peerdisc_segments );
|
||||||
|
return segment;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Destroy PeerDist discovery segment
|
||||||
|
*
|
||||||
|
* @v segment PeerDist discovery segment
|
||||||
|
*/
|
||||||
|
static void peerdisc_destroy ( struct peerdisc_segment *segment ) {
|
||||||
|
|
||||||
|
/* Sanity check */
|
||||||
|
assert ( list_empty ( &segment->clients ) );
|
||||||
|
|
||||||
|
/* Stop timer */
|
||||||
|
stop_timer ( &segment->timer );
|
||||||
|
|
||||||
|
/* Remove from list of segments and drop list's reference */
|
||||||
|
list_del ( &segment->list );
|
||||||
|
ref_put ( &segment->refcnt );
|
||||||
|
}
|
||||||
|
|
||||||
|
/******************************************************************************
|
||||||
|
*
|
||||||
|
* Discovery clients
|
||||||
|
*
|
||||||
|
******************************************************************************
|
||||||
|
*/
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Open PeerDist discovery client
|
||||||
|
*
|
||||||
|
* @v peerdisc PeerDist discovery client
|
||||||
|
* @v id Segment ID
|
||||||
|
* @v len Length of segment ID
|
||||||
|
* @ret rc Return status code
|
||||||
|
*/
|
||||||
|
int peerdisc_open ( struct peerdisc_client *peerdisc, const void *id,
|
||||||
|
size_t len ) {
|
||||||
|
struct peerdisc_segment *segment;
|
||||||
|
char id_string[ base16_encoded_len ( len ) + 1 /* NUL */ ];
|
||||||
|
char *id_chr;
|
||||||
|
int rc;
|
||||||
|
|
||||||
|
/* Construct ID string */
|
||||||
|
base16_encode ( id, len, id_string, sizeof ( id_string ) );
|
||||||
|
for ( id_chr = id_string ; *id_chr ; id_chr++ )
|
||||||
|
*id_chr = toupper ( *id_chr );
|
||||||
|
|
||||||
|
/* Sanity check */
|
||||||
|
assert ( peerdisc->segment == NULL );
|
||||||
|
|
||||||
|
/* Open socket if this is the first segment */
|
||||||
|
if ( list_empty ( &peerdisc_segments ) &&
|
||||||
|
( ( rc = peerdisc_socket_open() ) != 0 ) )
|
||||||
|
return rc;
|
||||||
|
|
||||||
|
/* Find or create segment */
|
||||||
|
if ( ! ( ( segment = peerdisc_find ( id_string ) ) ||
|
||||||
|
( segment = peerdisc_create ( id_string ) ) ) )
|
||||||
|
return -ENOMEM;
|
||||||
|
|
||||||
|
/* Add to list of clients */
|
||||||
|
ref_get ( &segment->refcnt );
|
||||||
|
peerdisc->segment = segment;
|
||||||
|
list_add_tail ( &peerdisc->list, &segment->clients );
|
||||||
|
|
||||||
|
return 0;
|
||||||
|
}
|
||||||
|
|
||||||
|
/**
|
||||||
|
* Close PeerDist discovery client
|
||||||
|
*
|
||||||
|
* @v peerdisc PeerDist discovery client
|
||||||
|
*/
|
||||||
|
void peerdisc_close ( struct peerdisc_client *peerdisc ) {
|
||||||
|
struct peerdisc_segment *segment = peerdisc->segment;
|
||||||
|
|
||||||
|
/* Ignore if discovery is already closed */
|
||||||
|
if ( ! segment )
|
||||||
|
return;
|
||||||
|
|
||||||
|
/* If no peers were discovered, reduce the recommended
|
||||||
|
* discovery timeout to minimise delays on future requests.
|
||||||
|
*/
|
||||||
|
if ( list_empty ( &segment->peers ) && peerdisc_timeout_secs ) {
|
||||||
|
peerdisc_timeout_secs--;
|
||||||
|
DBGC ( segment, "PEERDISC %p reducing timeout to %d "
|
||||||
|
"seconds\n", peerdisc, peerdisc_timeout_secs );
|
||||||
|
}
|
||||||
|
|
||||||
|
/* Remove from list of clients */
|
||||||
|
peerdisc->segment = NULL;
|
||||||
|
list_del ( &peerdisc->list );
|
||||||
|
ref_put ( &segment->refcnt );
|
||||||
|
|
||||||
|
/* If this was the last clients, destroy the segment */
|
||||||
|
if ( list_empty ( &segment->clients ) )
|
||||||
|
peerdisc_destroy ( segment );
|
||||||
|
|
||||||
|
/* If there are no more segments, close the socket */
|
||||||
|
if ( list_empty ( &peerdisc_segments ) )
|
||||||
|
peerdisc_socket_close ( 0 );
|
||||||
|
}
|
||||||
Loading…
Reference in New Issue