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opengnsys_ipxe/src/net/udp/tftp.c

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/*
* 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.
*/
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <strings.h>
#include <byteswap.h>
#include <errno.h>
#include <assert.h>
#include <gpxe/refcnt.h>
#include <gpxe/xfer.h>
#include <gpxe/open.h>
#include <gpxe/uri.h>
#include <gpxe/tcpip.h>
#include <gpxe/retry.h>
#include <gpxe/features.h>
#include <gpxe/bitmap.h>
#include <gpxe/settings.h>
#include <gpxe/dhcp.h>
#include <gpxe/uri.h>
#include <gpxe/tftp.h>
/** @file
*
* TFTP protocol
*
*/
FEATURE ( FEATURE_PROTOCOL, "TFTP", DHCP_EB_FEATURE_TFTP, 1 );
/* TFTP-specific error codes */
#define ETFTP_INVALID_BLKSIZE EUNIQ_01
#define ETFTP_INVALID_TSIZE EUNIQ_02
#define ETFTP_MC_NO_PORT EUNIQ_03
#define ETFTP_MC_NO_MC EUNIQ_04
#define ETFTP_MC_INVALID_MC EUNIQ_05
#define ETFTP_MC_INVALID_IP EUNIQ_06
#define ETFTP_MC_INVALID_PORT EUNIQ_07
/**
* A TFTP request
*
* This data structure holds the state for an ongoing TFTP transfer.
*/
struct tftp_request {
/** Reference count */
struct refcnt refcnt;
/** Data transfer interface */
struct xfer_interface xfer;
/** URI being fetched */
struct uri *uri;
/** Transport layer interface */
struct xfer_interface socket;
/** Multicast transport layer interface */
struct xfer_interface mc_socket;
/** Data block size
*
* This is the "blksize" option negotiated with the TFTP
* server. (If the TFTP server does not support TFTP options,
* this will default to 512).
*/
unsigned int blksize;
/** File size
*
* This is the value returned in the "tsize" option from the
* TFTP server. If the TFTP server does not support the
* "tsize" option, this value will be zero.
*/
unsigned long tsize;
/** Server port
*
* This is the port to which RRQ packets are sent.
*/
unsigned int port;
/** Peer address
*
* The peer address is determined by the first response
* received to the TFTP RRQ.
*/
struct sockaddr_tcpip peer;
/** Request flags */
unsigned int flags;
/** MTFTP timeout count */
unsigned int mtftp_timeouts;
/** Block bitmap */
struct bitmap bitmap;
/** Maximum known length
*
* We don't always know the file length in advance. In
* particular, if the TFTP server doesn't support the tsize
* option, or we are using MTFTP, then we don't know the file
* length until we see the end-of-file block (which, in the
* case of MTFTP, may not be the last block we see).
*
* This value is updated whenever we obtain information about
* the file length.
*/
size_t filesize;
/** Retransmission timer */
struct retry_timer timer;
};
/** TFTP request flags */
enum {
/** Send ACK packets */
TFTP_FL_SEND_ACK = 0x0001,
/** Request blksize and tsize options */
TFTP_FL_RRQ_SIZES = 0x0002,
/** Request multicast option */
TFTP_FL_RRQ_MULTICAST = 0x0004,
/** Perform MTFTP recovery on timeout */
TFTP_FL_MTFTP_RECOVERY = 0x0008,
};
/** Maximum number of MTFTP open requests before falling back to TFTP */
#define MTFTP_MAX_TIMEOUTS 3
/**
* Free TFTP request
*
* @v refcnt Reference counter
*/
static void tftp_free ( struct refcnt *refcnt ) {
struct tftp_request *tftp =
container_of ( refcnt, struct tftp_request, refcnt );
uri_put ( tftp->uri );
bitmap_free ( &tftp->bitmap );
free ( tftp );
}
/**
* Mark TFTP request as complete
*
* @v tftp TFTP connection
* @v rc Return status code
*/
static void tftp_done ( struct tftp_request *tftp, int rc ) {
DBGC ( tftp, "TFTP %p finished with status %d (%s)\n",
tftp, rc, strerror ( rc ) );
/* Stop the retry timer */
stop_timer ( &tftp->timer );
/* Close all data transfer interfaces */
xfer_nullify ( &tftp->socket );
xfer_close ( &tftp->socket, rc );
xfer_nullify ( &tftp->mc_socket );
xfer_close ( &tftp->mc_socket, rc );
xfer_nullify ( &tftp->xfer );
xfer_close ( &tftp->xfer, rc );
}
/**
* Reopen TFTP socket
*
* @v tftp TFTP connection
* @ret rc Return status code
*/
static int tftp_reopen ( struct tftp_request *tftp ) {
struct sockaddr_tcpip server;
int rc;
/* Close socket */
xfer_close ( &tftp->socket, 0 );
/* Disable ACK sending. */
tftp->flags &= ~TFTP_FL_SEND_ACK;
/* Reset peer address */
memset ( &tftp->peer, 0, sizeof ( tftp->peer ) );
/* Open socket */
memset ( &server, 0, sizeof ( server ) );
server.st_port = htons ( tftp->port );
if ( ( rc = xfer_open_named_socket ( &tftp->socket, SOCK_DGRAM,
( struct sockaddr * ) &server,
tftp->uri->host, NULL ) ) != 0 ) {
DBGC ( tftp, "TFTP %p could not open socket: %s\n",
tftp, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Reopen TFTP multicast socket
*
* @v tftp TFTP connection
* @v local Local socket address
* @ret rc Return status code
*/
static int tftp_reopen_mc ( struct tftp_request *tftp,
struct sockaddr *local ) {
int rc;
/* Close multicast socket */
xfer_close ( &tftp->mc_socket, 0 );
/* Open multicast socket. We never send via this socket, so
* use the local address as the peer address (since the peer
* address cannot be NULL).
*/
if ( ( rc = xfer_open_socket ( &tftp->mc_socket, SOCK_DGRAM,
local, local ) ) != 0 ) {
DBGC ( tftp, "TFTP %p could not open multicast "
"socket: %s\n", tftp, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* Presize TFTP receive buffers and block bitmap
*
* @v tftp TFTP connection
* @v filesize Known minimum file size
* @ret rc Return status code
*/
static int tftp_presize ( struct tftp_request *tftp, size_t filesize ) {
unsigned int num_blocks;
int rc;
/* Do nothing if we are already large enough */
if ( filesize <= tftp->filesize )
return 0;
/* Record filesize */
tftp->filesize = filesize;
/* Notify recipient of file size */
xfer_seek ( &tftp->xfer, filesize, SEEK_SET );
xfer_seek ( &tftp->xfer, 0, SEEK_SET );
/* Calculate expected number of blocks. Note that files whose
* length is an exact multiple of the blocksize will have a
* trailing zero-length block, which must be included.
*/
num_blocks = ( ( filesize / tftp->blksize ) + 1 );
if ( ( rc = bitmap_resize ( &tftp->bitmap, num_blocks ) ) != 0 ) {
DBGC ( tftp, "TFTP %p could not resize bitmap to %d blocks: "
"%s\n", tftp, num_blocks, strerror ( rc ) );
return rc;
}
return 0;
}
/**
* TFTP requested blocksize
*
* This is treated as a global configuration parameter.
*/
static unsigned int tftp_request_blksize = TFTP_MAX_BLKSIZE;
/**
* Set TFTP request blocksize
*
* @v blksize Requested block size
*/
void tftp_set_request_blksize ( unsigned int blksize ) {
if ( blksize < TFTP_DEFAULT_BLKSIZE )
blksize = TFTP_DEFAULT_BLKSIZE;
tftp_request_blksize = blksize;
}
/**
* MTFTP multicast receive address
*
* This is treated as a global configuration parameter.
*/
static struct sockaddr_in tftp_mtftp_socket = {
.sin_family = AF_INET,
.sin_addr.s_addr = htonl ( 0xefff0101 ),
.sin_port = htons ( 3001 ),
};
/**
* Set MTFTP multicast address
*
* @v address Multicast IPv4 address
*/
void tftp_set_mtftp_address ( struct in_addr address ) {
tftp_mtftp_socket.sin_addr = address;
}
/**
* Set MTFTP multicast port
*
* @v port Multicast port
*/
void tftp_set_mtftp_port ( unsigned int port ) {
tftp_mtftp_socket.sin_port = htons ( port );
}
/**
* Transmit RRQ
*
* @v tftp TFTP connection
* @ret rc Return status code
*/
static int tftp_send_rrq ( struct tftp_request *tftp ) {
struct tftp_rrq *rrq;
const char *path;
size_t len;
struct io_buffer *iobuf;
/* Strip initial '/' if present. If we were opened via the
* URI interface, then there will be an initial '/', since a
* full tftp:// URI provides no way to specify a non-absolute
* path. However, many TFTP servers (particularly Windows
* TFTP servers) complain about having an initial '/', and it
* violates user expectations to have a '/' silently added to
* the DHCP-specified filename.
*/
path = tftp->uri->path;
if ( *path == '/' )
path++;
DBGC ( tftp, "TFTP %p requesting \"%s\"\n", tftp, path );
/* Allocate buffer */
len = ( sizeof ( *rrq ) + strlen ( path ) + 1 /* NUL */
+ 5 + 1 /* "octet" + NUL */
+ 7 + 1 + 5 + 1 /* "blksize" + NUL + ddddd + NUL */
+ 5 + 1 + 1 + 1 /* "tsize" + NUL + "0" + NUL */
+ 9 + 1 + 1 /* "multicast" + NUL + NUL */ );
iobuf = xfer_alloc_iob ( &tftp->socket, len );
if ( ! iobuf )
return -ENOMEM;
/* Build request */
rrq = iob_put ( iobuf, sizeof ( *rrq ) );
rrq->opcode = htons ( TFTP_RRQ );
iob_put ( iobuf, snprintf ( iobuf->tail, iob_tailroom ( iobuf ),
"%s%coctet", path, 0 ) + 1 );
if ( tftp->flags & TFTP_FL_RRQ_SIZES ) {
iob_put ( iobuf, snprintf ( iobuf->tail,
iob_tailroom ( iobuf ),
"blksize%c%d%ctsize%c0", 0,
tftp_request_blksize, 0, 0 ) + 1 );
}
if ( tftp->flags & TFTP_FL_RRQ_MULTICAST ) {
iob_put ( iobuf, snprintf ( iobuf->tail,
iob_tailroom ( iobuf ),
"multicast%c", 0 ) + 1 );
}
/* RRQ always goes to the address specified in the initial
* xfer_open() call
*/
return xfer_deliver_iob ( &tftp->socket, iobuf );
}
/**
* Transmit ACK
*
* @v tftp TFTP connection
* @ret rc Return status code
*/
static int tftp_send_ack ( struct tftp_request *tftp ) {
struct tftp_ack *ack;
struct io_buffer *iobuf;
struct xfer_metadata meta = {
.dest = ( struct sockaddr * ) &tftp->peer,
};
unsigned int block;
/* Determine next required block number */
block = bitmap_first_gap ( &tftp->bitmap );
DBGC2 ( tftp, "TFTP %p sending ACK for block %d\n", tftp, block );
/* Allocate buffer */
iobuf = xfer_alloc_iob ( &tftp->socket, sizeof ( *ack ) );
if ( ! iobuf )
return -ENOMEM;
/* Build ACK */
ack = iob_put ( iobuf, sizeof ( *ack ) );
ack->opcode = htons ( TFTP_ACK );
ack->block = htons ( block );
/* ACK always goes to the peer recorded from the RRQ response */
return xfer_deliver_iob_meta ( &tftp->socket, iobuf, &meta );
}
/**
* Transmit next relevant packet
*
* @v tftp TFTP connection
* @ret rc Return status code
*/
static int tftp_send_packet ( struct tftp_request *tftp ) {
/* Update retransmission timer */
stop_timer ( &tftp->timer );
start_timer ( &tftp->timer );
/* Send RRQ or ACK as appropriate */
if ( ! tftp->peer.st_family ) {
return tftp_send_rrq ( tftp );
} else {
if ( tftp->flags & TFTP_FL_SEND_ACK ) {
return tftp_send_ack ( tftp );
} else {
return 0;
}
}
}
/**
* Handle TFTP retransmission timer expiry
*
* @v timer Retry timer
* @v fail Failure indicator
*/
static void tftp_timer_expired ( struct retry_timer *timer, int fail ) {
struct tftp_request *tftp =
container_of ( timer, struct tftp_request, timer );
int rc;
/* If we are doing MTFTP, attempt the various recovery strategies */
if ( tftp->flags & TFTP_FL_MTFTP_RECOVERY ) {
if ( tftp->peer.st_family ) {
/* If we have received any response from the server,
* try resending the RRQ to restart the download.
*/
DBGC ( tftp, "TFTP %p attempting reopen\n", tftp );
if ( ( rc = tftp_reopen ( tftp ) ) != 0 )
goto err;
} else {
/* Fall back to plain TFTP after several attempts */
tftp->mtftp_timeouts++;
DBGC ( tftp, "TFTP %p timeout %d waiting for MTFTP "
"open\n", tftp, tftp->mtftp_timeouts );
if ( tftp->mtftp_timeouts > MTFTP_MAX_TIMEOUTS ) {
DBGC ( tftp, "TFTP %p falling back to plain "
"TFTP\n", tftp );
tftp->flags = TFTP_FL_RRQ_SIZES;
/* Close multicast socket */
xfer_close ( &tftp->mc_socket, 0 );
/* Reset retry timer */
start_timer_nodelay ( &tftp->timer );
/* The blocksize may change: discard
* the block bitmap
*/
bitmap_free ( &tftp->bitmap );
memset ( &tftp->bitmap, 0,
sizeof ( tftp->bitmap ) );
/* Reopen on standard TFTP port */
tftp->port = TFTP_PORT;
if ( ( rc = tftp_reopen ( tftp ) ) != 0 )
goto err;
}
}
} else {
/* Not doing MTFTP (or have fallen back to plain
* TFTP); fail as per normal.
*/
if ( fail ) {
rc = -ETIMEDOUT;
goto err;
}
}
tftp_send_packet ( tftp );
return;
err:
tftp_done ( tftp, rc );
}
/**
* Process TFTP "blksize" option
*
* @v tftp TFTP connection
* @v value Option value
* @ret rc Return status code
*/
static int tftp_process_blksize ( struct tftp_request *tftp,
const char *value ) {
char *end;
tftp->blksize = strtoul ( value, &end, 10 );
if ( *end ) {
DBGC ( tftp, "TFTP %p got invalid blksize \"%s\"\n",
tftp, value );
return -( EINVAL | ETFTP_INVALID_BLKSIZE );
}
DBGC ( tftp, "TFTP %p blksize=%d\n", tftp, tftp->blksize );
return 0;
}
/**
* Process TFTP "tsize" option
*
* @v tftp TFTP connection
* @v value Option value
* @ret rc Return status code
*/
static int tftp_process_tsize ( struct tftp_request *tftp,
const char *value ) {
char *end;
tftp->tsize = strtoul ( value, &end, 10 );
if ( *end ) {
DBGC ( tftp, "TFTP %p got invalid tsize \"%s\"\n",
tftp, value );
return -( EINVAL | ETFTP_INVALID_TSIZE );
}
DBGC ( tftp, "TFTP %p tsize=%ld\n", tftp, tftp->tsize );
return 0;
}
/**
* Process TFTP "multicast" option
*
* @v tftp TFTP connection
* @v value Option value
* @ret rc Return status code
*/
static int tftp_process_multicast ( struct tftp_request *tftp,
const char *value ) {
union {
struct sockaddr sa;
struct sockaddr_in sin;
} socket;
char buf[ strlen ( value ) + 1 ];
char *addr;
char *port;
char *port_end;
char *mc;
char *mc_end;
int rc;
/* Split value into "addr,port,mc" fields */
memcpy ( buf, value, sizeof ( buf ) );
addr = buf;
port = strchr ( addr, ',' );
if ( ! port ) {
DBGC ( tftp, "TFTP %p multicast missing port,mc\n", tftp );
return -( EINVAL | ETFTP_MC_NO_PORT );
}
*(port++) = '\0';
mc = strchr ( port, ',' );
if ( ! mc ) {
DBGC ( tftp, "TFTP %p multicast missing mc\n", tftp );
return -( EINVAL | ETFTP_MC_NO_MC );
}
*(mc++) = '\0';
/* Parse parameters */
if ( strtoul ( mc, &mc_end, 0 ) == 0 )
tftp->flags &= ~TFTP_FL_SEND_ACK;
if ( *mc_end ) {
DBGC ( tftp, "TFTP %p multicast invalid mc %s\n", tftp, mc );
return -( EINVAL | ETFTP_MC_INVALID_MC );
}
DBGC ( tftp, "TFTP %p is%s the master client\n",
tftp, ( ( tftp->flags & TFTP_FL_SEND_ACK ) ? "" : " not" ) );
if ( *addr && *port ) {
socket.sin.sin_family = AF_INET;
if ( inet_aton ( addr, &socket.sin.sin_addr ) == 0 ) {
DBGC ( tftp, "TFTP %p multicast invalid IP address "
"%s\n", tftp, addr );
return -( EINVAL | ETFTP_MC_INVALID_IP );
}
DBGC ( tftp, "TFTP %p multicast IP address %s\n",
tftp, inet_ntoa ( socket.sin.sin_addr ) );
socket.sin.sin_port = htons ( strtoul ( port, &port_end, 0 ) );
if ( *port_end ) {
DBGC ( tftp, "TFTP %p multicast invalid port %s\n",
tftp, port );
return -( EINVAL | ETFTP_MC_INVALID_PORT );
}
DBGC ( tftp, "TFTP %p multicast port %d\n",
tftp, ntohs ( socket.sin.sin_port ) );
if ( ( rc = tftp_reopen_mc ( tftp, &socket.sa ) ) != 0 )
return rc;
}
return 0;
}
/** A TFTP option */
struct tftp_option {
/** Option name */
const char *name;
/** Option processor
*
* @v tftp TFTP connection
* @v value Option value
* @ret rc Return status code
*/
int ( * process ) ( struct tftp_request *tftp, const char *value );
};
/** Recognised TFTP options */
static struct tftp_option tftp_options[] = {
{ "blksize", tftp_process_blksize },
{ "tsize", tftp_process_tsize },
{ "multicast", tftp_process_multicast },
{ NULL, NULL }
};
/**
* Process TFTP option
*
* @v tftp TFTP connection
* @v name Option name
* @v value Option value
* @ret rc Return status code
*/
static int tftp_process_option ( struct tftp_request *tftp,
const char *name, const char *value ) {
struct tftp_option *option;
for ( option = tftp_options ; option->name ; option++ ) {
if ( strcasecmp ( name, option->name ) == 0 )
return option->process ( tftp, value );
}
DBGC ( tftp, "TFTP %p received unknown option \"%s\" = \"%s\"\n",
tftp, name, value );
/* Unknown options should be silently ignored */
return 0;
}
/**
* Receive OACK
*
* @v tftp TFTP connection
* @v buf Temporary data buffer
* @v len Length of temporary data buffer
* @ret rc Return status code
*/
static int tftp_rx_oack ( struct tftp_request *tftp, void *buf, size_t len ) {
struct tftp_oack *oack = buf;
char *end = buf + len;
char *name;
char *value;
int rc = 0;
/* Sanity check */
if ( len < sizeof ( *oack ) ) {
DBGC ( tftp, "TFTP %p received underlength OACK packet "
"length %zd\n", tftp, len );
rc = -EINVAL;
goto done;
}
if ( end[-1] != '\0' ) {
DBGC ( tftp, "TFTP %p received OACK missing final NUL\n",
tftp );
rc = -EINVAL;
goto done;
}
/* Process each option in turn */
name = oack->data;
while ( name < end ) {
value = ( name + strlen ( name ) + 1 );
if ( value == end ) {
DBGC ( tftp, "TFTP %p received OACK missing value "
"for option \"%s\"\n", tftp, name );
rc = -EINVAL;
goto done;
}
if ( ( rc = tftp_process_option ( tftp, name, value ) ) != 0 )
goto done;
name = ( value + strlen ( value ) + 1 );
}
/* Process tsize information, if available */
if ( tftp->tsize ) {
if ( ( rc = tftp_presize ( tftp, tftp->tsize ) ) != 0 )
goto done;
}
/* Request next data block */
tftp_send_packet ( tftp );
done:
if ( rc )
tftp_done ( tftp, rc );
return rc;
}
/**
* Receive DATA
*
* @v tftp TFTP connection
* @v iobuf I/O buffer
* @ret rc Return status code
*
* Takes ownership of I/O buffer.
*/
static int tftp_rx_data ( struct tftp_request *tftp,
struct io_buffer *iobuf ) {
struct tftp_data *data = iobuf->data;
struct xfer_metadata meta;
int block;
off_t offset;
size_t data_len;
int rc;
/* Sanity check */
if ( iob_len ( iobuf ) < sizeof ( *data ) ) {
DBGC ( tftp, "TFTP %p received underlength DATA packet "
"length %zd\n", tftp, iob_len ( iobuf ) );
rc = -EINVAL;
goto done;
}
/* Extract data */
block = ( ntohs ( data->block ) - 1 );
offset = ( block * tftp->blksize );
iob_pull ( iobuf, sizeof ( *data ) );
data_len = iob_len ( iobuf );
if ( data_len > tftp->blksize ) {
DBGC ( tftp, "TFTP %p received overlength DATA packet "
"length %zd\n", tftp, data_len );
rc = -EINVAL;
goto done;
}
/* Deliver data */
memset ( &meta, 0, sizeof ( meta ) );
meta.whence = SEEK_SET;
meta.offset = offset;
rc = xfer_deliver_iob_meta ( &tftp->xfer, iobuf, &meta );
iobuf = NULL;
if ( rc != 0 ) {
DBGC ( tftp, "TFTP %p could not deliver data: %s\n",
tftp, strerror ( rc ) );
goto done;
}
/* Ensure block bitmap is ready */
if ( ( rc = tftp_presize ( tftp, ( offset + data_len ) ) ) != 0 )
goto done;
/* Mark block as received */
bitmap_set ( &tftp->bitmap, block );
/* Acknowledge block */
tftp_send_packet ( tftp );
/* If all blocks have been received, finish. */
if ( bitmap_full ( &tftp->bitmap ) )
tftp_done ( tftp, 0 );
done:
free_iob ( iobuf );
if ( rc )
tftp_done ( tftp, rc );
return rc;
}
/** Translation between TFTP errors and internal error numbers */
static const int tftp_errors[] = {
[TFTP_ERR_FILE_NOT_FOUND] = ENOENT,
[TFTP_ERR_ACCESS_DENIED] = EACCES,
[TFTP_ERR_ILLEGAL_OP] = ENOTSUP,
};
/**
* Receive ERROR
*
* @v tftp TFTP connection
* @v buf Temporary data buffer
* @v len Length of temporary data buffer
* @ret rc Return status code
*/
static int tftp_rx_error ( struct tftp_request *tftp, void *buf, size_t len ) {
struct tftp_error *error = buf;
unsigned int err;
int rc = 0;
/* Sanity check */
if ( len < sizeof ( *error ) ) {
DBGC ( tftp, "TFTP %p received underlength ERROR packet "
"length %zd\n", tftp, len );
return -EINVAL;
}
DBGC ( tftp, "TFTP %p received ERROR packet with code %d, message "
"\"%s\"\n", tftp, ntohs ( error->errcode ), error->errmsg );
/* Determine final operation result */
err = ntohs ( error->errcode );
if ( err < ( sizeof ( tftp_errors ) / sizeof ( tftp_errors[0] ) ) )
rc = -tftp_errors[err];
if ( ! rc )
rc = -ENOTSUP;
/* Close TFTP request */
tftp_done ( tftp, rc );
return 0;
}
/**
* Receive new data
*
* @v tftp TFTP connection
* @v iobuf I/O buffer
* @v meta Transfer metadata, or NULL
* @ret rc Return status code
*/
static int tftp_rx ( struct tftp_request *tftp,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
struct sockaddr_tcpip *st_src;
struct tftp_common *common = iobuf->data;
size_t len = iob_len ( iobuf );
int rc = -EINVAL;
/* Sanity checks */
if ( len < sizeof ( *common ) ) {
DBGC ( tftp, "TFTP %p received underlength packet length "
"%zd\n", tftp, len );
goto done;
}
if ( ! meta ) {
DBGC ( tftp, "TFTP %p received packet without metadata\n",
tftp );
goto done;
}
if ( ! meta->src ) {
DBGC ( tftp, "TFTP %p received packet without source port\n",
tftp );
goto done;
}
/* Filter by TID. Set TID on first response received */
st_src = ( struct sockaddr_tcpip * ) meta->src;
if ( ! tftp->peer.st_family ) {
memcpy ( &tftp->peer, st_src, sizeof ( tftp->peer ) );
DBGC ( tftp, "TFTP %p using remote port %d\n", tftp,
ntohs ( tftp->peer.st_port ) );
} else if ( memcmp ( &tftp->peer, st_src,
sizeof ( tftp->peer ) ) != 0 ) {
DBGC ( tftp, "TFTP %p received packet from wrong source (got "
"%d, wanted %d)\n", tftp, ntohs ( st_src->st_port ),
ntohs ( tftp->peer.st_port ) );
goto done;
}
switch ( common->opcode ) {
case htons ( TFTP_OACK ):
rc = tftp_rx_oack ( tftp, iobuf->data, len );
break;
case htons ( TFTP_DATA ):
rc = tftp_rx_data ( tftp, iobuf );
iobuf = NULL;
break;
case htons ( TFTP_ERROR ):
rc = tftp_rx_error ( tftp, iobuf->data, len );
break;
default:
DBGC ( tftp, "TFTP %p received strange packet type %d\n",
tftp, ntohs ( common->opcode ) );
break;
};
done:
free_iob ( iobuf );
return rc;
}
/**
* Receive new data via socket
*
* @v socket Transport layer interface
* @v iobuf I/O buffer
* @v meta Transfer metadata, or NULL
* @ret rc Return status code
*/
static int tftp_socket_deliver_iob ( struct xfer_interface *socket,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
struct tftp_request *tftp =
container_of ( socket, struct tftp_request, socket );
/* Enable sending ACKs when we receive a unicast packet. This
* covers three cases:
*
* 1. Standard TFTP; we should always send ACKs, and will
* always receive a unicast packet before we need to send the
* first ACK.
*
* 2. RFC2090 multicast TFTP; the only unicast packets we will
* receive are the OACKs; enable sending ACKs here (before
* processing the OACK) and disable it when processing the
* multicast option if we are not the master client.
*
* 3. MTFTP; receiving a unicast datagram indicates that we
* are the "master client" and should send ACKs.
*/
tftp->flags |= TFTP_FL_SEND_ACK;
return tftp_rx ( tftp, iobuf, meta );
}
/** TFTP socket operations */
static struct xfer_interface_operations tftp_socket_operations = {
.close = ignore_xfer_close,
.vredirect = xfer_vopen,
.window = unlimited_xfer_window,
.alloc_iob = default_xfer_alloc_iob,
.deliver_iob = tftp_socket_deliver_iob,
.deliver_raw = xfer_deliver_as_iob,
};
/**
* Receive new data via multicast socket
*
* @v mc_socket Multicast transport layer interface
* @v iobuf I/O buffer
* @v meta Transfer metadata, or NULL
* @ret rc Return status code
*/
static int tftp_mc_socket_deliver_iob ( struct xfer_interface *mc_socket,
struct io_buffer *iobuf,
struct xfer_metadata *meta ) {
struct tftp_request *tftp =
container_of ( mc_socket, struct tftp_request, mc_socket );
return tftp_rx ( tftp, iobuf, meta );
}
/** TFTP multicast socket operations */
static struct xfer_interface_operations tftp_mc_socket_operations = {
.close = ignore_xfer_close,
.vredirect = xfer_vopen,
.window = unlimited_xfer_window,
.alloc_iob = default_xfer_alloc_iob,
.deliver_iob = tftp_mc_socket_deliver_iob,
.deliver_raw = xfer_deliver_as_iob,
};
/**
* Close TFTP data transfer interface
*
* @v xfer Data transfer interface
* @v rc Reason for close
*/
static void tftp_xfer_close ( struct xfer_interface *xfer, int rc ) {
struct tftp_request *tftp =
container_of ( xfer, struct tftp_request, xfer );
DBGC ( tftp, "TFTP %p interface closed: %s\n",
tftp, strerror ( rc ) );
tftp_done ( tftp, rc );
}
/**
* Check flow control window
*
* @v xfer Data transfer interface
* @ret len Length of window
*/
static size_t tftp_xfer_window ( struct xfer_interface *xfer ) {
struct tftp_request *tftp =
container_of ( xfer, struct tftp_request, xfer );
/* We abuse this data-xfer method to convey the blocksize to
* the caller. This really should be done using some kind of
* stat() method, but we don't yet have the facility to do
* that.
*/
return tftp->blksize;
}
/** TFTP data transfer interface operations */
static struct xfer_interface_operations tftp_xfer_operations = {
.close = tftp_xfer_close,
.vredirect = ignore_xfer_vredirect,
.window = tftp_xfer_window,
.alloc_iob = default_xfer_alloc_iob,
.deliver_iob = xfer_deliver_as_raw,
.deliver_raw = ignore_xfer_deliver_raw,
};
/**
* Initiate TFTP/TFTM/MTFTP download
*
* @v xfer Data transfer interface
* @v uri Uniform Resource Identifier
* @ret rc Return status code
*/
static int tftp_core_open ( struct xfer_interface *xfer, struct uri *uri,
unsigned int default_port,
struct sockaddr *multicast,
unsigned int flags ) {
struct tftp_request *tftp;
int rc;
/* Sanity checks */
if ( ! uri->host )
return -EINVAL;
if ( ! uri->path )
return -EINVAL;
/* Allocate and populate TFTP structure */
tftp = zalloc ( sizeof ( *tftp ) );
if ( ! tftp )
return -ENOMEM;
tftp->refcnt.free = tftp_free;
xfer_init ( &tftp->xfer, &tftp_xfer_operations, &tftp->refcnt );
tftp->uri = uri_get ( uri );
xfer_init ( &tftp->socket, &tftp_socket_operations, &tftp->refcnt );
xfer_init ( &tftp->mc_socket, &tftp_mc_socket_operations,
&tftp->refcnt );
tftp->blksize = TFTP_DEFAULT_BLKSIZE;
tftp->flags = flags;
tftp->timer.expired = tftp_timer_expired;
/* Open socket */
tftp->port = uri_port ( tftp->uri, default_port );
if ( ( rc = tftp_reopen ( tftp ) ) != 0 )
goto err;
/* Open multicast socket */
if ( multicast ) {
if ( ( rc = tftp_reopen_mc ( tftp, multicast ) ) != 0 )
goto err;
}
/* Start timer to initiate RRQ */
start_timer_nodelay ( &tftp->timer );
/* Attach to parent interface, mortalise self, and return */
xfer_plug_plug ( &tftp->xfer, xfer );
ref_put ( &tftp->refcnt );
return 0;
err:
DBGC ( tftp, "TFTP %p could not create request: %s\n",
tftp, strerror ( rc ) );
tftp_done ( tftp, rc );
ref_put ( &tftp->refcnt );
return rc;
}
/**
* Initiate TFTP download
*
* @v xfer Data transfer interface
* @v uri Uniform Resource Identifier
* @ret rc Return status code
*/
static int tftp_open ( struct xfer_interface *xfer, struct uri *uri ) {
return tftp_core_open ( xfer, uri, TFTP_PORT, NULL,
TFTP_FL_RRQ_SIZES );
}
/** TFTP URI opener */
struct uri_opener tftp_uri_opener __uri_opener = {
.scheme = "tftp",
.open = tftp_open,
};
/**
* Initiate TFTM download
*
* @v xfer Data transfer interface
* @v uri Uniform Resource Identifier
* @ret rc Return status code
*/
static int tftm_open ( struct xfer_interface *xfer, struct uri *uri ) {
return tftp_core_open ( xfer, uri, TFTP_PORT, NULL,
( TFTP_FL_RRQ_SIZES |
TFTP_FL_RRQ_MULTICAST ) );
}
/** TFTM URI opener */
struct uri_opener tftm_uri_opener __uri_opener = {
.scheme = "tftm",
.open = tftm_open,
};
/**
* Initiate MTFTP download
*
* @v xfer Data transfer interface
* @v uri Uniform Resource Identifier
* @ret rc Return status code
*/
static int mtftp_open ( struct xfer_interface *xfer, struct uri *uri ) {
return tftp_core_open ( xfer, uri, MTFTP_PORT,
( struct sockaddr * ) &tftp_mtftp_socket,
TFTP_FL_MTFTP_RECOVERY );
}
/** MTFTP URI opener */
struct uri_opener mtftp_uri_opener __uri_opener = {
.scheme = "mtftp",
.open = mtftp_open,
};
/******************************************************************************
*
* Settings
*
******************************************************************************
*/
/** TFTP server setting */
struct setting next_server_setting __setting = {
.name = "next-server",
.description = "TFTP server",
.tag = DHCP_EB_SIADDR,
.type = &setting_type_ipv4,
};
/**
* Apply TFTP configuration settings
*
* @ret rc Return status code
*/
static int tftp_apply_settings ( void ) {
static struct in_addr tftp_server = { 0 };
struct in_addr last_tftp_server;
char uri_string[32];
struct uri *uri;
/* Retrieve TFTP server setting */
last_tftp_server = tftp_server;
fetch_ipv4_setting ( NULL, &next_server_setting, &tftp_server );
/* If TFTP server setting has changed, set the current working
* URI to match. Do it only when the TFTP server has changed
* to try to minimise surprises to the user, who probably
* won't expect the CWURI to change just because they updated
* an unrelated setting and triggered all the settings
* applicators.
*/
if ( tftp_server.s_addr != last_tftp_server.s_addr ) {
snprintf ( uri_string, sizeof ( uri_string ),
"tftp://%s/", inet_ntoa ( tftp_server ) );
uri = parse_uri ( uri_string );
if ( ! uri )
return -ENOMEM;
churi ( uri );
uri_put ( uri );
}
return 0;
}
/** TFTP settings applicator */
struct settings_applicator tftp_settings_applicator __settings_applicator = {
.apply = tftp_apply_settings,
};
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