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authorH. Peter Anvin <hpa@zytor.com>2008-06-13 16:20:05 -0700
committerH. Peter Anvin <hpa@zytor.com>2008-06-13 16:20:05 -0700
commit958ddda00522f768bf9adc86c0d5b446e0a672cf (patch)
treed03715b7cbd8580f90ebb231fcc987137776b3f7 /gpxe/src/net
parent0095d560ef91676d3a07db560f58ca83d85bff95 (diff)
downloadsyslinux.git-958ddda00522f768bf9adc86c0d5b446e0a672cf.tar.gz
syslinux.git-958ddda00522f768bf9adc86c0d5b446e0a672cf.tar.xz
syslinux.git-958ddda00522f768bf9adc86c0d5b446e0a672cf.zip
gpxe: update gpxe to latest git
Diffstat (limited to 'gpxe/src/net')
-rw-r--r--gpxe/src/net/retry.c9
-rw-r--r--gpxe/src/net/udp.c51
-rw-r--r--gpxe/src/net/udp/dhcp.c10
-rw-r--r--gpxe/src/net/udp/slam.c810
4 files changed, 852 insertions, 28 deletions
diff --git a/gpxe/src/net/retry.c b/gpxe/src/net/retry.c
index 90b89711..3c934018 100644
--- a/gpxe/src/net/retry.c
+++ b/gpxe/src/net/retry.c
@@ -74,15 +74,14 @@ void start_timer ( struct retry_timer *timer ) {
}
/**
- * Start timer with no delay
+ * Start timer with a specified fixed timeout
*
* @v timer Retry timer
- *
- * This starts the timer running with a zero timeout value.
+ * @v timeout Timeout, in ticks
*/
-void start_timer_nodelay ( struct retry_timer *timer ) {
+void start_timer_fixed ( struct retry_timer *timer, unsigned long timeout ) {
start_timer ( timer );
- timer->timeout = 0;
+ timer->timeout = timeout;
}
/**
diff --git a/gpxe/src/net/udp.c b/gpxe/src/net/udp.c
index 89a5b868..8df76a44 100644
--- a/gpxe/src/net/udp.c
+++ b/gpxe/src/net/udp.c
@@ -29,10 +29,10 @@ struct udp_connection {
/** Data transfer interface */
struct xfer_interface xfer;
+ /** Local socket address */
+ struct sockaddr_tcpip local;
/** Remote socket address */
struct sockaddr_tcpip peer;
- /** Local port on which the connection receives packets */
- unsigned int local_port;
};
/**
@@ -48,22 +48,22 @@ struct tcpip_protocol udp_protocol;
* Bind UDP connection to local port
*
* @v udp UDP connection
- * @v port Local port, in network byte order, or zero
* @ret rc Return status code
*
- * Opens the UDP connection and binds to a local port. If no local
- * port is specified, the first available port will be used.
+ * Opens the UDP connection and binds to the specified local port. If
+ * no local port is specified, the first available port will be used.
*/
-static int udp_bind ( struct udp_connection *udp, unsigned int port ) {
+static int udp_bind ( struct udp_connection *udp ) {
struct udp_connection *existing;
static uint16_t try_port = 1024;
/* If no port specified, find the first available port */
- if ( ! port ) {
+ if ( ! udp->local.st_port ) {
for ( ; try_port ; try_port++ ) {
if ( try_port < 1024 )
continue;
- if ( udp_bind ( udp, htons ( try_port ) ) == 0 )
+ udp->local.st_port = htons ( try_port );
+ if ( udp_bind ( udp ) == 0 )
return 0;
}
return -EADDRINUSE;
@@ -71,16 +71,16 @@ static int udp_bind ( struct udp_connection *udp, unsigned int port ) {
/* Attempt bind to local port */
list_for_each_entry ( existing, &udp_conns, list ) {
- if ( existing->local_port == port ) {
+ if ( existing->local.st_port == udp->local.st_port ) {
DBGC ( udp, "UDP %p could not bind: port %d in use\n",
- udp, ntohs ( port ) );
+ udp, ntohs ( udp->local.st_port ) );
return -EADDRINUSE;
}
}
- udp->local_port = port;
/* Add to UDP connection list */
- DBGC ( udp, "UDP %p bound to port %d\n", udp, ntohs ( port ) );
+ DBGC ( udp, "UDP %p bound to port %d\n",
+ udp, ntohs ( udp->local.st_port ) );
return 0;
}
@@ -100,7 +100,6 @@ static int udp_open_common ( struct xfer_interface *xfer,
struct sockaddr_tcpip *st_peer = ( struct sockaddr_tcpip * ) peer;
struct sockaddr_tcpip *st_local = ( struct sockaddr_tcpip * ) local;
struct udp_connection *udp;
- unsigned int bind_port;
int rc;
/* Allocate and initialise structure */
@@ -111,11 +110,12 @@ static int udp_open_common ( struct xfer_interface *xfer,
xfer_init ( &udp->xfer, &udp_xfer_operations, &udp->refcnt );
if ( st_peer )
memcpy ( &udp->peer, st_peer, sizeof ( udp->peer ) );
+ if ( st_local )
+ memcpy ( &udp->local, st_local, sizeof ( udp->local ) );
/* Bind to local port */
if ( ! promisc ) {
- bind_port = ( st_local ? st_local->st_port : 0 );
- if ( ( rc = udp_bind ( udp, bind_port ) ) != 0 )
+ if ( ( rc = udp_bind ( udp ) ) != 0 )
goto err;
}
@@ -201,7 +201,7 @@ static int udp_tx ( struct udp_connection *udp, struct io_buffer *iobuf,
/* Fill in default values if not explicitly provided */
if ( ! src_port )
- src_port = udp->local_port;
+ src_port = udp->local.st_port;
if ( ! dest )
dest = &udp->peer;
@@ -231,17 +231,24 @@ static int udp_tx ( struct udp_connection *udp, struct io_buffer *iobuf,
}
/**
- * Identify UDP connection by local port number
+ * Identify UDP connection by local address
*
- * @v local_port Local port (in network-endian order)
+ * @v local Local address
* @ret udp UDP connection, or NULL
*/
-static struct udp_connection * udp_demux ( unsigned int local_port ) {
+static struct udp_connection * udp_demux ( struct sockaddr_tcpip *local ) {
+ static const struct sockaddr_tcpip empty_sockaddr;
struct udp_connection *udp;
list_for_each_entry ( udp, &udp_conns, list ) {
- if ( ( udp->local_port == local_port ) ||
- ( udp->local_port == 0 ) ) {
+ if ( ( ( udp->local.st_family == local->st_family ) ||
+ ( udp->local.st_family == 0 ) ) &&
+ ( ( udp->local.st_port == local->st_port ) ||
+ ( udp->local.st_port == 0 ) ) &&
+ ( ( memcmp ( udp->local.pad, local->pad,
+ sizeof ( udp->local.pad ) ) == 0 ) ||
+ ( memcmp ( udp->local.pad, empty_sockaddr.pad,
+ sizeof ( udp->local.pad ) ) == 0 ) ) ) {
return udp;
}
}
@@ -300,7 +307,7 @@ static int udp_rx ( struct io_buffer *iobuf, struct sockaddr_tcpip *st_src,
/* Parse parameters from header and strip header */
st_src->st_port = udphdr->src;
st_dest->st_port = udphdr->dest;
- udp = udp_demux ( udphdr->dest );
+ udp = udp_demux ( st_dest );
iob_unput ( iobuf, ( iob_len ( iobuf ) - ulen ) );
iob_pull ( iobuf, sizeof ( *udphdr ) );
diff --git a/gpxe/src/net/udp/dhcp.c b/gpxe/src/net/udp/dhcp.c
index ecb73785..6ff8afe9 100644
--- a/gpxe/src/net/udp/dhcp.c
+++ b/gpxe/src/net/udp/dhcp.c
@@ -260,6 +260,14 @@ static struct dhcp_settings * dhcpset_create ( const struct dhcphdr *dhcphdr,
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
@@ -924,7 +932,7 @@ static void dhcp_timer_expired ( struct retry_timer *timer, int fail ) {
}
/* Give up waiting for ProxyDHCP before we reach the failure point */
- if ( elapsed > PROXYDHCP_WAIT_TIME ) {
+ if ( dhcp->dhcpoffer && ( elapsed > PROXYDHCP_WAIT_TIME ) ) {
if ( dhcp->state == DHCP_STATE_DISCOVER ) {
dhcp_set_state ( dhcp, DHCP_STATE_REQUEST );
return;
diff --git a/gpxe/src/net/udp/slam.c b/gpxe/src/net/udp/slam.c
new file mode 100644
index 00000000..cb0dfa5c
--- /dev/null
+++ b/gpxe/src/net/udp/slam.c
@@ -0,0 +1,810 @@
+/*
+ * Copyright (C) 2008 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+#include <assert.h>
+#include <byteswap.h>
+#include <gpxe/features.h>
+#include <gpxe/iobuf.h>
+#include <gpxe/bitmap.h>
+#include <gpxe/xfer.h>
+#include <gpxe/open.h>
+#include <gpxe/uri.h>
+#include <gpxe/tcpip.h>
+#include <gpxe/timer.h>
+#include <gpxe/retry.h>
+
+/** @file
+ *
+ * Scalable Local Area Multicast protocol
+ *
+ * The SLAM protocol is supported only by Etherboot; it was designed
+ * and implemented by Eric Biederman. A server implementation is
+ * available in contrib/mini-slamd. There does not appear to be any
+ * documentation beyond a few sparse comments in Etherboot's
+ * proto_slam.c.
+ *
+ * SLAM packets use three types of data field:
+ *
+ * Nul : A single NUL (0) byte, used as a list terminator
+ *
+ * Raw : A block of raw data
+ *
+ * Int : A variable-length integer, in big-endian order. The length
+ * of the integer is encoded in the most significant three bits.
+ *
+ * Packets received by the client have the following layout:
+ *
+ * Int : Transaction identifier. This is an opaque value.
+ *
+ * Int : Total number of bytes in the transfer.
+ *
+ * Int : Block size, in bytes.
+ *
+ * Int : Packet sequence number within the transfer (if this packet
+ * contains data).
+ *
+ * Raw : Packet data (if this packet contains data).
+ *
+ * Packets transmitted by the client consist of a run-length-encoded
+ * representation of the received-blocks bitmap, looking something
+ * like:
+ *
+ * Int : Number of consecutive successfully-received packets
+ * Int : Number of consecutive missing packets
+ * Int : Number of consecutive successfully-received packets
+ * Int : Number of consecutive missing packets
+ * ....
+ * Nul
+ *
+ */
+
+FEATURE ( FEATURE_PROTOCOL, "SLAM", DHCP_EB_FEATURE_SLAM, 1 );
+
+/** Default SLAM server port */
+#define SLAM_DEFAULT_PORT 10000
+
+/** Default SLAM multicast IP address */
+#define SLAM_DEFAULT_MULTICAST_IP \
+ ( ( 239 << 24 ) | ( 255 << 16 ) | ( 1 << 8 ) | ( 1 << 0 ) )
+
+/** Default SLAM multicast port */
+#define SLAM_DEFAULT_MULTICAST_PORT 10000
+
+/** Maximum SLAM header length */
+#define SLAM_MAX_HEADER_LEN ( 7 /* transaction id */ + 7 /* total_bytes */ + \
+ 7 /* block_size */ )
+
+/** Maximum number of blocks to request per NACK
+ *
+ * This is a policy decision equivalent to selecting a TCP window
+ * size.
+ */
+#define SLAM_MAX_BLOCKS_PER_NACK 4
+
+/** Maximum SLAM NACK length
+ *
+ * We only ever send a NACK for a single range of up to @c
+ * SLAM_MAX_BLOCKS_PER_NACK blocks.
+ */
+#define SLAM_MAX_NACK_LEN ( 7 /* block */ + 7 /* #blocks */ + 1 /* NUL */ )
+
+/** SLAM slave timeout */
+#define SLAM_SLAVE_TIMEOUT ( 1 * TICKS_PER_SEC )
+
+/** A SLAM request */
+struct slam_request {
+ /** Reference counter */
+ struct refcnt refcnt;
+
+ /** Data transfer interface */
+ struct xfer_interface xfer;
+ /** Unicast socket */
+ struct xfer_interface socket;
+ /** Multicast socket */
+ struct xfer_interface mc_socket;
+
+ /** Master client retry timer */
+ struct retry_timer master_timer;
+ /** Slave client retry timer */
+ struct retry_timer slave_timer;
+
+ /** Cached header */
+ uint8_t header[SLAM_MAX_HEADER_LEN];
+ /** Size of cached header */
+ size_t header_len;
+ /** Total number of bytes in transfer */
+ unsigned long total_bytes;
+ /** Transfer block size */
+ unsigned long block_size;
+ /** Number of blocks in transfer */
+ unsigned long num_blocks;
+ /** Block bitmap */
+ struct bitmap bitmap;
+ /** NACK sent flag */
+ int nack_sent;
+};
+
+/**
+ * Free a SLAM request
+ *
+ * @v refcnt Reference counter
+ */
+static void slam_free ( struct refcnt *refcnt ) {
+ struct slam_request *slam =
+ container_of ( refcnt, struct slam_request, refcnt );
+
+ bitmap_free ( &slam->bitmap );
+ free ( slam );
+}
+
+/**
+ * Mark SLAM request as complete
+ *
+ * @v slam SLAM request
+ * @v rc Return status code
+ */
+static void slam_finished ( struct slam_request *slam, int rc ) {
+ static const uint8_t slam_disconnect[] = { 0 };
+
+ DBGC ( slam, "SLAM %p finished with status code %d (%s)\n",
+ slam, rc, strerror ( rc ) );
+
+ /* Send a disconnect message if we ever sent anything to the
+ * server.
+ */
+ if ( slam->nack_sent ) {
+ xfer_deliver_raw ( &slam->socket, slam_disconnect,
+ sizeof ( slam_disconnect ) );
+ }
+
+ /* Stop the retry timers */
+ stop_timer ( &slam->master_timer );
+ stop_timer ( &slam->slave_timer );
+
+ /* Close all data transfer interfaces */
+ xfer_nullify ( &slam->socket );
+ xfer_close ( &slam->socket, rc );
+ xfer_nullify ( &slam->mc_socket );
+ xfer_close ( &slam->mc_socket, rc );
+ xfer_nullify ( &slam->xfer );
+ xfer_close ( &slam->xfer, rc );
+}
+
+/****************************************************************************
+ *
+ * TX datapath
+ *
+ */
+
+/**
+ * Add a variable-length value to a SLAM packet
+ *
+ * @v slam SLAM request
+ * @v iobuf I/O buffer
+ * @v value Value to add
+ * @ret rc Return status code
+ *
+ * Adds a variable-length value to the end of an I/O buffer. Will
+ * always leave at least one byte of tailroom in the I/O buffer (to
+ * allow space for the terminating NUL).
+ */
+static int slam_put_value ( struct slam_request *slam,
+ struct io_buffer *iobuf, unsigned long value ) {
+ uint8_t *data;
+ size_t len;
+ unsigned int i;
+
+ /* Calculate variable length required to store value. Always
+ * leave at least one byte in the I/O buffer.
+ */
+ len = ( ( flsl ( value ) + 10 ) / 8 );
+ if ( len >= iob_tailroom ( iobuf ) ) {
+ DBGC2 ( slam, "SLAM %p cannot add %d-byte value\n",
+ slam, len );
+ return -ENOBUFS;
+ }
+ /* There is no valid way within the protocol that we can end
+ * up trying to push a full-sized long (i.e. without space for
+ * the length encoding).
+ */
+ assert ( len <= sizeof ( value ) );
+
+ /* Add value */
+ data = iob_put ( iobuf, len );
+ for ( i = len ; i-- ; ) {
+ data[i] = value;
+ value >>= 8;
+ }
+ *data |= ( len << 5 );
+ assert ( value == 0 );
+
+ return 0;
+}
+
+/**
+ * Send SLAM NACK packet
+ *
+ * @v slam SLAM request
+ * @ret rc Return status code
+ */
+static int slam_tx_nack ( struct slam_request *slam ) {
+ struct io_buffer *iobuf;
+ unsigned long first_block;
+ unsigned long num_blocks;
+ uint8_t *nul;
+ int rc;
+
+ /* Mark NACK as sent, so that we know we have to disconnect later */
+ slam->nack_sent = 1;
+
+ /* Allocate I/O buffer */
+ iobuf = xfer_alloc_iob ( &slam->socket, SLAM_MAX_NACK_LEN );
+ if ( ! iobuf ) {
+ DBGC ( slam, "SLAM %p could not allocate I/O buffer\n",
+ slam );
+ return -ENOMEM;
+ }
+
+ /* Construct NACK. We always request only a single packet;
+ * this allows us to force multicast-TFTP-style flow control
+ * on the SLAM server, which will otherwise just blast the
+ * data out as fast as it can. On a gigabit network, without
+ * RX checksumming, this would inevitably cause packet drops.
+ */
+ first_block = bitmap_first_gap ( &slam->bitmap );
+ for ( num_blocks = 1 ; ; num_blocks++ ) {
+ if ( num_blocks >= SLAM_MAX_BLOCKS_PER_NACK )
+ break;
+ if ( ( first_block + num_blocks ) >= slam->num_blocks )
+ break;
+ if ( bitmap_test ( &slam->bitmap,
+ ( first_block + num_blocks ) ) )
+ break;
+ }
+ if ( first_block ) {
+ DBGCP ( slam, "SLAM %p transmitting NACK for blocks "
+ "%ld-%ld\n", slam, first_block,
+ ( first_block + num_blocks - 1 ) );
+ } else {
+ DBGC ( slam, "SLAM %p transmitting initial NACK for blocks "
+ "0-%ld\n", slam, ( num_blocks - 1 ) );
+ }
+ if ( ( rc = slam_put_value ( slam, iobuf, first_block ) ) != 0 )
+ return rc;
+ if ( ( rc = slam_put_value ( slam, iobuf, num_blocks ) ) != 0 )
+ return rc;
+ nul = iob_put ( iobuf, 1 );
+ *nul = 0;
+
+ /* Transmit packet */
+ return xfer_deliver_iob ( &slam->socket, iobuf );
+}
+
+/**
+ * Handle SLAM master client retry timer expiry
+ *
+ * @v timer Master retry timer
+ * @v fail Failure indicator
+ */
+static void slam_master_timer_expired ( struct retry_timer *timer,
+ int fail ) {
+ struct slam_request *slam =
+ container_of ( timer, struct slam_request, master_timer );
+
+ if ( fail ) {
+ /* Allow timer to stop running. We will terminate the
+ * connection only if the slave timer times out.
+ */
+ DBGC ( slam, "SLAM %p giving up acting as master client\n",
+ slam );
+ } else {
+ /* Retransmit NACK */
+ start_timer ( timer );
+ slam_tx_nack ( slam );
+ }
+}
+
+/**
+ * Handle SLAM slave client retry timer expiry
+ *
+ * @v timer Master retry timer
+ * @v fail Failure indicator
+ */
+static void slam_slave_timer_expired ( struct retry_timer *timer,
+ int fail ) {
+ struct slam_request *slam =
+ container_of ( timer, struct slam_request, slave_timer );
+
+ if ( fail ) {
+ /* Terminate connection */
+ slam_finished ( slam, -ETIMEDOUT );
+ } else {
+ /* Try sending a NACK */
+ DBGC ( slam, "SLAM %p trying to become master client\n",
+ slam );
+ start_timer ( timer );
+ slam_tx_nack ( slam );
+ }
+}
+
+/****************************************************************************
+ *
+ * RX datapath
+ *
+ */
+
+/**
+ * Read and strip a variable-length value from a SLAM packet
+ *
+ * @v slam SLAM request
+ * @v iobuf I/O buffer
+ * @v value Value to fill in, or NULL to ignore value
+ * @ret rc Return status code
+ *
+ * Reads a variable-length value from the start of the I/O buffer.
+ */
+static int slam_pull_value ( struct slam_request *slam,
+ struct io_buffer *iobuf,
+ unsigned long *value ) {
+ uint8_t *data;
+ size_t len;
+
+ /* Sanity check */
+ if ( iob_len ( iobuf ) == 0 ) {
+ DBGC ( slam, "SLAM %p empty value\n", slam );
+ return -EINVAL;
+ }
+
+ /* Read and verify length of value */
+ data = iobuf->data;
+ len = ( *data >> 5 );
+ if ( ( len == 0 ) ||
+ ( value && ( len > sizeof ( *value ) ) ) ) {
+ DBGC ( slam, "SLAM %p invalid value length %d bytes\n",
+ slam, len );
+ return -EINVAL;
+ }
+ if ( len > iob_len ( iobuf ) ) {
+ DBGC ( slam, "SLAM %p value extends beyond I/O buffer\n",
+ slam );
+ return -EINVAL;
+ }
+
+ /* Read value */
+ iob_pull ( iobuf, len );
+ *value = ( *data & 0x1f );
+ while ( --len ) {
+ *value <<= 8;
+ *value |= *(++data);
+ }
+
+ return 0;
+}
+
+/**
+ * Read and strip SLAM header
+ *
+ * @v slam SLAM request
+ * @v iobuf I/O buffer
+ * @ret rc Return status code
+ */
+static int slam_pull_header ( struct slam_request *slam,
+ struct io_buffer *iobuf ) {
+ void *header = iobuf->data;
+ int rc;
+
+ /* If header matches cached header, just pull it and return */
+ if ( ( slam->header_len <= iob_len ( iobuf ) ) &&
+ ( memcmp ( slam->header, iobuf->data, slam->header_len ) == 0 )){
+ iob_pull ( iobuf, slam->header_len );
+ return 0;
+ }
+
+ DBGC ( slam, "SLAM %p detected changed header; resetting\n", slam );
+
+ /* Read and strip transaction ID, total number of bytes, and
+ * block size.
+ */
+ if ( ( rc = slam_pull_value ( slam, iobuf, NULL ) ) != 0 )
+ return rc;
+ if ( ( rc = slam_pull_value ( slam, iobuf,
+ &slam->total_bytes ) ) != 0 )
+ return rc;
+ if ( ( rc = slam_pull_value ( slam, iobuf,
+ &slam->block_size ) ) != 0 )
+ return rc;
+
+ /* Update the cached header */
+ slam->header_len = ( iobuf->data - header );
+ assert ( slam->header_len <= sizeof ( slam->header ) );
+ memcpy ( slam->header, header, slam->header_len );
+
+ /* Calculate number of blocks */
+ slam->num_blocks = ( ( slam->total_bytes + slam->block_size - 1 ) /
+ slam->block_size );
+
+ DBGC ( slam, "SLAM %p has total bytes %ld, block size %ld, num "
+ "blocks %ld\n", slam, slam->total_bytes, slam->block_size,
+ slam->num_blocks );
+
+ /* Discard and reset the bitmap */
+ bitmap_free ( &slam->bitmap );
+ memset ( &slam->bitmap, 0, sizeof ( slam->bitmap ) );
+
+ /* Allocate a new bitmap */
+ if ( ( rc = bitmap_resize ( &slam->bitmap,
+ slam->num_blocks ) ) != 0 ) {
+ /* Failure to allocate a bitmap is fatal */
+ DBGC ( slam, "SLAM %p could not allocate bitmap for %ld "
+ "blocks: %s\n", slam, slam->num_blocks,
+ strerror ( rc ) );
+ slam_finished ( slam, rc );
+ return rc;
+ }
+
+ /* Notify recipient of file size */
+ xfer_seek ( &slam->xfer, slam->total_bytes, SEEK_SET );
+
+ return 0;
+}
+
+/**
+ * Receive SLAM data packet
+ *
+ * @v mc_socket SLAM multicast socket
+ * @v iobuf I/O buffer
+ * @ret rc Return status code
+ */
+static int slam_mc_socket_deliver ( struct xfer_interface *mc_socket,
+ struct io_buffer *iobuf,
+ struct xfer_metadata *rx_meta __unused ) {
+ struct slam_request *slam =
+ container_of ( mc_socket, struct slam_request, mc_socket );
+ struct xfer_metadata meta;
+ unsigned long packet;
+ size_t len;
+ int rc;
+
+ /* Stop the master client timer. Restart the slave client timer. */
+ stop_timer ( &slam->master_timer );
+ stop_timer ( &slam->slave_timer );
+ start_timer_fixed ( &slam->slave_timer, SLAM_SLAVE_TIMEOUT );
+
+ /* Read and strip packet header */
+ if ( ( rc = slam_pull_header ( slam, iobuf ) ) != 0 )
+ goto err_discard;
+
+ /* Read and strip packet number */
+ if ( ( rc = slam_pull_value ( slam, iobuf, &packet ) ) != 0 )
+ goto err_discard;
+
+ /* Sanity check packet number */
+ if ( packet >= slam->num_blocks ) {
+ DBGC ( slam, "SLAM %p received out-of-range packet %ld "
+ "(num_blocks=%ld)\n", slam, packet, slam->num_blocks );
+ rc = -EINVAL;
+ goto err_discard;
+ }
+
+ /* Sanity check length */
+ len = iob_len ( iobuf );
+ if ( len > slam->block_size ) {
+ DBGC ( slam, "SLAM %p received oversize packet of %zd bytes "
+ "(block_size=%ld)\n", slam, len, slam->block_size );
+ rc = -EINVAL;
+ goto err_discard;
+ }
+ if ( ( packet != ( slam->num_blocks - 1 ) ) &&
+ ( len < slam->block_size ) ) {
+ DBGC ( slam, "SLAM %p received short packet of %zd bytes "
+ "(block_size=%ld)\n", slam, len, slam->block_size );
+ rc = -EINVAL;
+ goto err_discard;
+ }
+
+ /* If we have already seen this packet, discard it */
+ if ( bitmap_test ( &slam->bitmap, packet ) ) {
+ goto discard;
+ }
+
+ /* Pass to recipient */
+ memset ( &meta, 0, sizeof ( meta ) );
+ meta.whence = SEEK_SET;
+ meta.offset = ( packet * slam->block_size );
+ if ( ( rc = xfer_deliver_iob_meta ( &slam->xfer, iobuf,
+ &meta ) ) != 0 )
+ goto err;
+
+ /* Mark block as received */
+ bitmap_set ( &slam->bitmap, packet );
+
+ /* If we have received all blocks, terminate */
+ if ( bitmap_full ( &slam->bitmap ) )
+ slam_finished ( slam, 0 );
+
+ return 0;
+
+ err_discard:
+ discard:
+ free_iob ( iobuf );
+ err:
+ return rc;
+}
+
+/**
+ * Receive SLAM non-data packet
+ *
+ * @v socket SLAM unicast socket
+ * @v iobuf I/O buffer
+ * @ret rc Return status code
+ */
+static int slam_socket_deliver ( struct xfer_interface *socket,
+ struct io_buffer *iobuf,
+ struct xfer_metadata *rx_meta __unused ) {
+ struct slam_request *slam =
+ container_of ( socket, struct slam_request, socket );
+ int rc;
+
+ /* Restart the master client timer */
+ stop_timer ( &slam->master_timer );
+ start_timer ( &slam->master_timer );
+
+ /* Read and strip packet header */
+ if ( ( rc = slam_pull_header ( slam, iobuf ) ) != 0 )
+ goto discard;
+
+ /* Sanity check */
+ if ( iob_len ( iobuf ) != 0 ) {
+ DBGC ( slam, "SLAM %p received trailing garbage:\n", slam );
+ DBGC_HD ( slam, iobuf->data, iob_len ( iobuf ) );
+ rc = -EINVAL;
+ goto discard;
+ }
+
+ /* Discard packet */
+ free_iob ( iobuf );
+
+ /* Send NACK in reply */
+ slam_tx_nack ( slam );
+
+ return 0;
+
+ discard:
+ free_iob ( iobuf );
+ return rc;
+
+}
+
+/**
+ * Close SLAM unicast socket
+ *
+ * @v socket SLAM unicast socket
+ * @v rc Reason for close
+ */
+static void slam_socket_close ( struct xfer_interface *socket, int rc ) {
+ struct slam_request *slam =
+ container_of ( socket, struct slam_request, socket );
+
+ DBGC ( slam, "SLAM %p unicast socket closed: %s\n",
+ slam, strerror ( rc ) );
+
+ slam_finished ( slam, rc );
+}
+
+/** SLAM unicast socket data transfer operations */
+static struct xfer_interface_operations slam_socket_operations = {
+ .close = slam_socket_close,
+ .vredirect = xfer_vopen,
+ .window = unlimited_xfer_window,
+ .alloc_iob = default_xfer_alloc_iob,
+ .deliver_iob = slam_socket_deliver,
+ .deliver_raw = xfer_deliver_as_iob,
+};
+
+/**
+ * Close SLAM multicast socket
+ *
+ * @v mc_socket SLAM multicast socket
+ * @v rc Reason for close
+ */
+static void slam_mc_socket_close ( struct xfer_interface *mc_socket, int rc ){
+ struct slam_request *slam =
+ container_of ( mc_socket, struct slam_request, mc_socket );
+
+ DBGC ( slam, "SLAM %p multicast socket closed: %s\n",
+ slam, strerror ( rc ) );
+
+ slam_finished ( slam, rc );
+}
+
+/** SLAM multicast socket data transfer operations */
+static struct xfer_interface_operations slam_mc_socket_operations = {
+ .close = slam_mc_socket_close,
+ .vredirect = xfer_vopen,
+ .window = unlimited_xfer_window,
+ .alloc_iob = default_xfer_alloc_iob,
+ .deliver_iob = slam_mc_socket_deliver,
+ .deliver_raw = xfer_deliver_as_iob,
+};
+
+/****************************************************************************
+ *
+ * Data transfer interface
+ *
+ */
+
+/**
+ * Close SLAM data transfer interface
+ *
+ * @v xfer SLAM data transfer interface
+ * @v rc Reason for close
+ */
+static void slam_xfer_close ( struct xfer_interface *xfer, int rc ) {
+ struct slam_request *slam =
+ container_of ( xfer, struct slam_request, xfer );
+
+ DBGC ( slam, "SLAM %p data transfer interface closed: %s\n",
+ slam, strerror ( rc ) );
+
+ slam_finished ( slam, rc );
+}
+
+/** SLAM data transfer operations */
+static struct xfer_interface_operations slam_xfer_operations = {
+ .close = slam_xfer_close,
+ .vredirect = ignore_xfer_vredirect,
+ .window = unlimited_xfer_window,
+ .alloc_iob = default_xfer_alloc_iob,
+ .deliver_iob = xfer_deliver_as_raw,
+ .deliver_raw = ignore_xfer_deliver_raw,
+};
+
+/**
+ * Parse SLAM URI multicast address
+ *
+ * @v slam SLAM request
+ * @v path Path portion of x-slam:// URI
+ * @v address Socket address to fill in
+ * @ret rc Return status code
+ */
+static int slam_parse_multicast_address ( struct slam_request *slam,
+ const char *path,
+ struct sockaddr_in *address ) {
+ char path_dup[ strlen ( path ) /* no +1 */ ];
+ char *sep;
+ char *end;
+
+ /* Create temporary copy of path, minus the leading '/' */
+ assert ( *path == '/' );
+ memcpy ( path_dup, ( path + 1 ) , sizeof ( path_dup ) );
+
+ /* Parse port, if present */
+ sep = strchr ( path_dup, ':' );
+ if ( sep ) {
+ *(sep++) = '\0';
+ address->sin_port = htons ( strtoul ( sep, &end, 0 ) );
+ if ( *end != '\0' ) {
+ DBGC ( slam, "SLAM %p invalid multicast port "
+ "\"%s\"\n", slam, sep );
+ return -EINVAL;
+ }
+ }
+
+ /* Parse address */
+ if ( inet_aton ( path_dup, &address->sin_addr ) == 0 ) {
+ DBGC ( slam, "SLAM %p invalid multicast address \"%s\"\n",
+ slam, path_dup );
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+/**
+ * Initiate a SLAM request
+ *
+ * @v xfer Data transfer interface
+ * @v uri Uniform Resource Identifier
+ * @ret rc Return status code
+ */
+static int slam_open ( struct xfer_interface *xfer, struct uri *uri ) {
+ static const struct sockaddr_in default_multicast = {
+ .sin_family = AF_INET,
+ .sin_port = htons ( SLAM_DEFAULT_MULTICAST_PORT ),
+ .sin_addr = { htonl ( SLAM_DEFAULT_MULTICAST_IP ) },
+ };
+ struct slam_request *slam;
+ struct sockaddr_tcpip server;
+ struct sockaddr_in multicast;
+ int rc;
+
+ /* Sanity checks */
+ if ( ! uri->host )
+ return -EINVAL;
+
+ /* Allocate and populate structure */
+ slam = zalloc ( sizeof ( *slam ) );
+ if ( ! slam )
+ return -ENOMEM;
+ slam->refcnt.free = slam_free;
+ xfer_init ( &slam->xfer, &slam_xfer_operations, &slam->refcnt );
+ xfer_init ( &slam->socket, &slam_socket_operations, &slam->refcnt );
+ xfer_init ( &slam->mc_socket, &slam_mc_socket_operations,
+ &slam->refcnt );
+ slam->master_timer.expired = slam_master_timer_expired;
+ slam->slave_timer.expired = slam_slave_timer_expired;
+ /* Fake an invalid cached header of { 0x00, ... } */
+ slam->header_len = 1;
+ /* Fake parameters for initial NACK */
+ slam->num_blocks = 1;
+ if ( ( rc = bitmap_resize ( &slam->bitmap, 1 ) ) != 0 ) {
+ DBGC ( slam, "SLAM %p could not allocate initial bitmap: "
+ "%s\n", slam, strerror ( rc ) );
+ goto err;
+ }
+
+ /* Open unicast socket */
+ memset ( &server, 0, sizeof ( server ) );
+ server.st_port = htons ( uri_port ( uri, SLAM_DEFAULT_PORT ) );
+ if ( ( rc = xfer_open_named_socket ( &slam->socket, SOCK_DGRAM,
+ ( struct sockaddr * ) &server,
+ uri->host, NULL ) ) != 0 ) {
+ DBGC ( slam, "SLAM %p could not open unicast socket: %s\n",
+ slam, strerror ( rc ) );
+ goto err;
+ }
+
+ /* Open multicast socket */
+ memcpy ( &multicast, &default_multicast, sizeof ( multicast ) );
+ if ( uri->path &&
+ ( ( rc = slam_parse_multicast_address ( slam, uri->path,
+ &multicast ) ) != 0 ) ) {
+ goto err;
+ }
+ if ( ( rc = xfer_open_socket ( &slam->mc_socket, SOCK_DGRAM,
+ ( struct sockaddr * ) &multicast,
+ ( struct sockaddr * ) &multicast ) ) != 0 ) {
+ DBGC ( slam, "SLAM %p could not open multicast socket: %s\n",
+ slam, strerror ( rc ) );
+ goto err;
+ }
+
+ /* Start slave retry timer */
+ start_timer_fixed ( &slam->slave_timer, SLAM_SLAVE_TIMEOUT );
+
+ /* Attach to parent interface, mortalise self, and return */
+ xfer_plug_plug ( &slam->xfer, xfer );
+ ref_put ( &slam->refcnt );
+ return 0;
+
+ err:
+ slam_finished ( slam, rc );
+ ref_put ( &slam->refcnt );
+ return rc;
+}
+
+/** SLAM URI opener */
+struct uri_opener slam_uri_opener __uri_opener = {
+ .scheme = "x-slam",
+ .open = slam_open,
+};