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      1 /*
      2  * Copyright (C) 2006 Michael Brown <mbrown (at) fensystems.co.uk>.
      3  *
      4  * This program is free software; you can redistribute it and/or
      5  * modify it under the terms of the GNU General Public License as
      6  * published by the Free Software Foundation; either version 2 of the
      7  * License, or any later version.
      8  *
      9  * This program is distributed in the hope that it will be useful, but
     10  * WITHOUT ANY WARRANTY; without even the implied warranty of
     11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     12  * General Public License for more details.
     13  *
     14  * You should have received a copy of the GNU General Public License
     15  * along with this program; if not, write to the Free Software
     16  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
     17  */
     18 
     19 FILE_LICENCE ( GPL2_OR_LATER );
     20 
     21 #include <stddef.h>
     22 #include <string.h>
     23 #include <stdio.h>
     24 #include <stdlib.h>
     25 #include <errno.h>
     26 #include <assert.h>
     27 #include <byteswap.h>
     28 #include <gpxe/list.h>
     29 #include <gpxe/if_ether.h>
     30 #include <gpxe/ethernet.h>
     31 #include <gpxe/iobuf.h>
     32 #include <gpxe/uaccess.h>
     33 #include <gpxe/ata.h>
     34 #include <gpxe/netdevice.h>
     35 #include <gpxe/process.h>
     36 #include <gpxe/features.h>
     37 #include <gpxe/aoe.h>
     38 
     39 /** @file
     40  *
     41  * AoE protocol
     42  *
     43  */
     44 
     45 FEATURE ( FEATURE_PROTOCOL, "AoE", DHCP_EB_FEATURE_AOE, 1 );
     46 
     47 struct net_protocol aoe_protocol;
     48 
     49 /** List of all AoE sessions */
     50 static LIST_HEAD ( aoe_sessions );
     51 
     52 static void aoe_free ( struct refcnt *refcnt ) {
     53 	struct aoe_session *aoe =
     54 		container_of ( refcnt, struct aoe_session, refcnt );
     55 
     56 	netdev_put ( aoe->netdev );
     57 	free ( aoe );
     58 }
     59 
     60 /**
     61  * Mark current AoE command complete
     62  *
     63  * @v aoe		AoE session
     64  * @v rc		Return status code
     65  */
     66 static void aoe_done ( struct aoe_session *aoe, int rc ) {
     67 
     68 	/* Record overall command status */
     69 	if ( aoe->command ) {
     70 		aoe->command->cb.cmd_stat = aoe->status;
     71 		aoe->command->rc = rc;
     72 		aoe->command = NULL;
     73 	}
     74 
     75 	/* Stop retransmission timer */
     76 	stop_timer ( &aoe->timer );
     77 
     78 	/* Mark operation as complete */
     79 	aoe->rc = rc;
     80 }
     81 
     82 /**
     83  * Send AoE command
     84  *
     85  * @v aoe		AoE session
     86  * @ret rc		Return status code
     87  *
     88  * This transmits an AoE command packet.  It does not wait for a
     89  * response.
     90  */
     91 static int aoe_send_command ( struct aoe_session *aoe ) {
     92 	struct ata_command *command = aoe->command;
     93 	struct io_buffer *iobuf;
     94 	struct aoehdr *aoehdr;
     95 	union aoecmd *aoecmd;
     96 	struct aoeata *aoeata;
     97 	unsigned int count;
     98 	unsigned int data_out_len;
     99 	unsigned int aoecmdlen;
    100 
    101 	/* Fail immediately if we have no netdev to send on */
    102 	if ( ! aoe->netdev ) {
    103 		aoe_done ( aoe, -ENETUNREACH );
    104 		return -ENETUNREACH;
    105 	}
    106 
    107 	/* If we are transmitting anything that requires a response,
    108          * start the retransmission timer.  Do this before attempting
    109          * to allocate the I/O buffer, in case allocation itself
    110          * fails.
    111          */
    112 	start_timer ( &aoe->timer );
    113 
    114 	/* Calculate count and data_out_len for this subcommand */
    115 	switch ( aoe->aoe_cmd_type ) {
    116 	case AOE_CMD_ATA:
    117 		count = command->cb.count.native;
    118 		if ( count > AOE_MAX_COUNT )
    119 			count = AOE_MAX_COUNT;
    120 		data_out_len = ( command->data_out ?
    121 				 ( count * ATA_SECTOR_SIZE ) : 0 );
    122 		aoecmdlen = sizeof ( aoecmd->ata );
    123 		break;
    124 	case AOE_CMD_CONFIG:
    125 		count = 0;
    126 		data_out_len = 0;
    127 		aoecmdlen = sizeof ( aoecmd->cfg );
    128 		break;
    129 	default:
    130 		return -ENOTSUP;
    131 	}
    132 
    133 	/* Create outgoing I/O buffer */
    134 	iobuf = alloc_iob ( ETH_HLEN + sizeof ( *aoehdr ) +
    135 			    aoecmdlen + data_out_len );
    136 
    137 	if ( ! iobuf )
    138 		return -ENOMEM;
    139 	iob_reserve ( iobuf, ETH_HLEN );
    140 	aoehdr = iob_put ( iobuf, sizeof ( *aoehdr ) );
    141 	aoecmd = iob_put ( iobuf, aoecmdlen );
    142 	memset ( aoehdr, 0, ( sizeof ( *aoehdr ) + aoecmdlen ) );
    143 
    144 	/* Fill AoE header */
    145 	aoehdr->ver_flags = AOE_VERSION;
    146 	aoehdr->major = htons ( aoe->major );
    147 	aoehdr->minor = aoe->minor;
    148 	aoehdr->command = aoe->aoe_cmd_type;
    149 	aoehdr->tag = htonl ( ++aoe->tag );
    150 
    151 	/* Fill AoE payload */
    152 	switch ( aoe->aoe_cmd_type ) {
    153 	case AOE_CMD_ATA:
    154 		/* Fill AoE command */
    155 		aoeata = &aoecmd->ata;
    156 		linker_assert ( AOE_FL_DEV_HEAD	== ATA_DEV_SLAVE,
    157 				__fix_ata_h__ );
    158 		aoeata->aflags = ( ( command->cb.lba48 ? AOE_FL_EXTENDED : 0 )|
    159 				   ( command->cb.device & ATA_DEV_SLAVE ) |
    160 				   ( data_out_len ? AOE_FL_WRITE : 0 ) );
    161 		aoeata->err_feat = command->cb.err_feat.bytes.cur;
    162 		aoeata->count = count;
    163 		aoeata->cmd_stat = command->cb.cmd_stat;
    164 		aoeata->lba.u64 = cpu_to_le64 ( command->cb.lba.native );
    165 		if ( ! command->cb.lba48 )
    166 			aoeata->lba.bytes[3] |=
    167 				( command->cb.device & ATA_DEV_MASK );
    168 
    169 		/* Fill data payload */
    170 		copy_from_user ( iob_put ( iobuf, data_out_len ),
    171 				 command->data_out, aoe->command_offset,
    172 				 data_out_len );
    173 		break;
    174 	case AOE_CMD_CONFIG:
    175 		/* Nothing to do */
    176 		break;
    177 	default:
    178 		assert ( 0 );
    179 	}
    180 
    181 	/* Send packet */
    182 	return net_tx ( iobuf, aoe->netdev, &aoe_protocol, aoe->target );
    183 }
    184 
    185 /**
    186  * Handle AoE retry timer expiry
    187  *
    188  * @v timer		AoE retry timer
    189  * @v fail		Failure indicator
    190  */
    191 static void aoe_timer_expired ( struct retry_timer *timer, int fail ) {
    192 	struct aoe_session *aoe =
    193 		container_of ( timer, struct aoe_session, timer );
    194 
    195 	if ( fail ) {
    196 		aoe_done ( aoe, -ETIMEDOUT );
    197 	} else {
    198 		aoe_send_command ( aoe );
    199 	}
    200 }
    201 
    202 /**
    203  * Handle AoE configuration command response
    204  *
    205  * @v aoe		AoE session
    206  * @v ll_source		Link-layer source address
    207  * @ret rc		Return status code
    208  */
    209 static int aoe_rx_cfg ( struct aoe_session *aoe, const void *ll_source ) {
    210 
    211 	/* Record target MAC address */
    212 	memcpy ( aoe->target, ll_source, sizeof ( aoe->target ) );
    213 	DBGC ( aoe, "AoE %p target MAC address %s\n",
    214 	       aoe, eth_ntoa ( aoe->target ) );
    215 
    216 	/* Mark config request as complete */
    217 	aoe_done ( aoe, 0 );
    218 
    219 	return 0;
    220 }
    221 
    222 /**
    223  * Handle AoE ATA command response
    224  *
    225  * @v aoe		AoE session
    226  * @v aoeata		AoE ATA command
    227  * @v len		Length of AoE ATA command
    228  * @ret rc		Return status code
    229  */
    230 static int aoe_rx_ata ( struct aoe_session *aoe, struct aoeata *aoeata,
    231 			size_t len ) {
    232 	struct ata_command *command = aoe->command;
    233 	unsigned int rx_data_len;
    234 	unsigned int count;
    235 	unsigned int data_len;
    236 
    237 	/* Sanity check */
    238 	if ( len < sizeof ( *aoeata ) ) {
    239 		/* Ignore packet; allow timer to trigger retransmit */
    240 		return -EINVAL;
    241 	}
    242 	rx_data_len = ( len - sizeof ( *aoeata ) );
    243 
    244 	/* Calculate count and data_len for this subcommand */
    245 	count = command->cb.count.native;
    246 	if ( count > AOE_MAX_COUNT )
    247 		count = AOE_MAX_COUNT;
    248 	data_len = count * ATA_SECTOR_SIZE;
    249 
    250 	/* Merge into overall ATA status */
    251 	aoe->status |= aoeata->cmd_stat;
    252 
    253 	/* Copy data payload */
    254 	if ( command->data_in ) {
    255 		if ( rx_data_len > data_len )
    256 			rx_data_len = data_len;
    257 		copy_to_user ( command->data_in, aoe->command_offset,
    258 			       aoeata->data, rx_data_len );
    259 	}
    260 
    261 	/* Update ATA command and offset */
    262 	aoe->command_offset += data_len;
    263 	command->cb.lba.native += count;
    264 	command->cb.count.native -= count;
    265 
    266 	/* Check for operation complete */
    267 	if ( ! command->cb.count.native ) {
    268 		aoe_done ( aoe, 0 );
    269 		return 0;
    270 	}
    271 
    272 	/* Transmit next portion of request */
    273 	stop_timer ( &aoe->timer );
    274 	aoe_send_command ( aoe );
    275 
    276 	return 0;
    277 }
    278 
    279 /**
    280  * Process incoming AoE packets
    281  *
    282  * @v iobuf		I/O buffer
    283  * @v netdev		Network device
    284  * @v ll_source		Link-layer source address
    285  * @ret rc		Return status code
    286  *
    287  */
    288 static int aoe_rx ( struct io_buffer *iobuf,
    289 		    struct net_device *netdev __unused,
    290 		    const void *ll_source ) {
    291 	struct aoehdr *aoehdr = iobuf->data;
    292 	struct aoe_session *aoe;
    293 	int rc = 0;
    294 
    295 	/* Sanity checks */
    296 	if ( iob_len ( iobuf ) < sizeof ( *aoehdr ) ) {
    297 		rc = -EINVAL;
    298 		goto done;
    299 	}
    300 	if ( ( aoehdr->ver_flags & AOE_VERSION_MASK ) != AOE_VERSION ) {
    301 		rc = -EPROTONOSUPPORT;
    302 		goto done;
    303 	}
    304 	if ( ! ( aoehdr->ver_flags & AOE_FL_RESPONSE ) ) {
    305 		/* Ignore AoE requests that we happen to see */
    306 		goto done;
    307 	}
    308 	iob_pull ( iobuf, sizeof ( *aoehdr ) );
    309 
    310 	/* Demultiplex amongst active AoE sessions */
    311 	list_for_each_entry ( aoe, &aoe_sessions, list ) {
    312 		if ( ntohs ( aoehdr->major ) != aoe->major )
    313 			continue;
    314 		if ( aoehdr->minor != aoe->minor )
    315 			continue;
    316 		if ( ntohl ( aoehdr->tag ) != aoe->tag )
    317 			continue;
    318 		if ( aoehdr->ver_flags & AOE_FL_ERROR ) {
    319 			aoe_done ( aoe, -EIO );
    320 			break;
    321 		}
    322 		switch ( aoehdr->command ) {
    323 		case AOE_CMD_ATA:
    324 			rc = aoe_rx_ata ( aoe, iobuf->data, iob_len ( iobuf ));
    325 			break;
    326 		case AOE_CMD_CONFIG:
    327 			rc = aoe_rx_cfg ( aoe, ll_source );
    328 			break;
    329 		default:
    330 			DBGC ( aoe, "AoE %p ignoring command %02x\n",
    331 			       aoe, aoehdr->command );
    332 			break;
    333 		}
    334 		break;
    335 	}
    336 
    337  done:
    338 	free_iob ( iobuf );
    339 	return rc;
    340 }
    341 
    342 /** AoE protocol */
    343 struct net_protocol aoe_protocol __net_protocol = {
    344 	.name = "AoE",
    345 	.net_proto = htons ( ETH_P_AOE ),
    346 	.rx = aoe_rx,
    347 };
    348 
    349 /**
    350  * Issue ATA command via an open AoE session
    351  *
    352  * @v ata		ATA device
    353  * @v command		ATA command
    354  * @ret rc		Return status code
    355  */
    356 static int aoe_command ( struct ata_device *ata,
    357 			 struct ata_command *command ) {
    358 	struct aoe_session *aoe =
    359 		container_of ( ata->backend, struct aoe_session, refcnt );
    360 
    361 	aoe->command = command;
    362 	aoe->status = 0;
    363 	aoe->command_offset = 0;
    364 	aoe->aoe_cmd_type = AOE_CMD_ATA;
    365 
    366 	aoe_send_command ( aoe );
    367 
    368 	return 0;
    369 }
    370 
    371 /**
    372  * Issue AoE config query for AoE target discovery
    373  *
    374  * @v aoe		AoE session
    375  * @ret rc		Return status code
    376  */
    377 static int aoe_discover ( struct aoe_session *aoe ) {
    378 	int rc;
    379 
    380 	aoe->status = 0;
    381 	aoe->aoe_cmd_type = AOE_CMD_CONFIG;
    382 	aoe->command = NULL;
    383 
    384 	aoe_send_command ( aoe );
    385 
    386 	aoe->rc = -EINPROGRESS;
    387 	while ( aoe->rc == -EINPROGRESS )
    388 		step();
    389 	rc = aoe->rc;
    390 
    391 	return rc;
    392 }
    393 
    394 static int aoe_detached_command ( struct ata_device *ata __unused,
    395 				  struct ata_command *command __unused ) {
    396 	return -ENODEV;
    397 }
    398 
    399 void aoe_detach ( struct ata_device *ata ) {
    400 	struct aoe_session *aoe =
    401 		container_of ( ata->backend, struct aoe_session, refcnt );
    402 
    403 	stop_timer ( &aoe->timer );
    404 	ata->command = aoe_detached_command;
    405 	list_del ( &aoe->list );
    406 	ref_put ( ata->backend );
    407 	ata->backend = NULL;
    408 }
    409 
    410 static int aoe_parse_root_path ( struct aoe_session *aoe,
    411 				 const char *root_path ) {
    412 	char *ptr;
    413 
    414 	if ( strncmp ( root_path, "aoe:", 4 ) != 0 )
    415 		return -EINVAL;
    416 	ptr = ( ( char * ) root_path + 4 );
    417 
    418 	if ( *ptr++ != 'e' )
    419 		return -EINVAL;
    420 
    421 	aoe->major = strtoul ( ptr, &ptr, 10 );
    422 	if ( *ptr++ != '.' )
    423 		return -EINVAL;
    424 
    425 	aoe->minor = strtoul ( ptr, &ptr, 10 );
    426 	if ( *ptr )
    427 		return -EINVAL;
    428 
    429 	return 0;
    430 }
    431 
    432 int aoe_attach ( struct ata_device *ata, struct net_device *netdev,
    433 		 const char *root_path ) {
    434 	struct aoe_session *aoe;
    435 	int rc;
    436 
    437 	/* Allocate and initialise structure */
    438 	aoe = zalloc ( sizeof ( *aoe ) );
    439 	if ( ! aoe )
    440 		return -ENOMEM;
    441 	aoe->refcnt.free = aoe_free;
    442 	aoe->netdev = netdev_get ( netdev );
    443 	memcpy ( aoe->target, netdev->ll_broadcast, sizeof ( aoe->target ) );
    444 	aoe->tag = AOE_TAG_MAGIC;
    445 	aoe->timer.expired = aoe_timer_expired;
    446 
    447 	/* Parse root path */
    448 	if ( ( rc = aoe_parse_root_path ( aoe, root_path ) ) != 0 )
    449 		goto err;
    450 
    451 	/* Attach parent interface, transfer reference to connection
    452 	 * list, and return
    453 	 */
    454 	ata->backend = ref_get ( &aoe->refcnt );
    455 	ata->command = aoe_command;
    456 	list_add ( &aoe->list, &aoe_sessions );
    457 
    458 	/* Send discovery packet to find the target MAC address.
    459 	 * Ideally, this ought to be done asynchronously, but the
    460 	 * block device interface does not yet support asynchronous
    461 	 * operation.
    462 	 */
    463 	if ( ( rc = aoe_discover( aoe ) ) != 0 )
    464 	       goto err;
    465 
    466 	return 0;
    467 
    468  err:
    469 	ref_put ( &aoe->refcnt );
    470 	return rc;
    471 }
    472