iscsi_client.c

一个iSCSI协议实现源代码

/* 
 *  $Id: iscsi_client.c,v 1.24 2001/04/24 05:49:09 mbrown Exp $
 *
 *  iscsi_client.c implements the iSCSI initiator (or client) SCSI adapter
 *  driver.  This is based on a proposed iSCSI standard 
 *  ( http://search.ietf.org/internet-drafts/draft-ietf-ips-iscsi-03.txt ) 
 *  and as all internet drafts in intended to be a work in progress.  
 *  Therefore this driver will likely break, change significantly, and
 *  corrupt your hard disks.
 *  Copyright (C) 2001 Michael F. Brown ([e-mail])
 * 
 *  Changes :
 *
 *  $Log: iscsi_client.c,v $
 *  Revision 1.24  2001/04/24 05:49:09  mbrown
 *  verbose error messages commented for now
 *
 *  Revision 1.23  2001/04/24 05:05:08  mbrown
 *  write functionality functional
 *
 *  Revision 1.22  2001/04/24 03:51:42  mbrown
 *  more fixes for scsi write data
 *
 *  Revision 1.21  2001/04/24 03:28:54  mbrown
 *  fixed but in write data
 *
 *  Revision 1.20  2001/04/24 00:33:39  mbrown
 *  write bug fix (still hacked)
 *
 *  Revision 1.19  2001/04/24 00:04:47  mbrown
 *  fixed bugs
 *
 *  Revision 1.18  2001/04/23 23:41:39  mbrown
 *  fixed bugs
 *
 *  Revision 1.17  2001/04/23 22:50:27  jhawkins
 *  added converge read for READ_DATA op
 *
 *  Revision 1.16  2001/04/23 19:18:34  mbrown
 *  changed target addr to cypher, (10.1.1.20)
 *
 *  Revision 1.15  2001/04/21 04:07:01  mbrown
 *  more bug fixing, mount readonly works, use the new DISK file, it
 *  contains a valid ext2 partition
 *
 *  Revision 1.14  2001/04/20 03:35:01  mbrown
 *  lun bug fixed, debug prints in big endian order
 *
 *  Revision 1.13  2001/04/19 15:16:50  mbrown
 *  devices now show up, fdisk still causes a kernel panic,
 *  checkin per jhawkins' request
 *
 *  Revision 1.12  2001/04/18 07:56:36  mbrown
 *  more debug output in reader() and dispatch()
 *
 *  Revision 1.11  2001/04/18 07:52:43  mbrown
 *  minor cleanup
 *
 *  Revision 1.10  2001/04/15 03:50:00  jhawkins
 *  successful login after a bit of hacking, changed version code expectation from 0 to 1, target sends us a 1
 *
 *  Revision 1.9  2001/04/15 03:01:04  mostman
 *  Some debugging
 *
 *  Revision 1.8  2001/04/15 02:58:27  jhawkins
 *  address/localhost issues
 *
 *  Revision 1.7  2001/04/11 20:33:57  mbrown
 *  debug string newline fixes, aesthetic update
 *
 *  Revision 1.6  2001/04/06 04:07:37  mbrown
 *  bug fix having to do with byte ordering fixed.  Added lots of debug
 *  prints in iscsi_client.c now that I can start testing
 *
 *  Revision 1.5  2001/04/03 09:44:58  mbrown
 *  iscsi.o and iscsi_client.o now successfully compile.
 *
 *  Revision 1.4  2001/04/03 03:04:39  mbrown
 *  latest and greatest hacks.  iscsi_client_reader() implemented along with
 *  iscsi_client_proc_info().  Should be all set to test now, will work
 *  on compiling.
 *
 *  Revision 1.3  2001/03/12 10:49:31  mbrown
 *  iscsi_client is now basically fully implemented minus proper
 *  /proc communication and compilation fixes.  This is going
 *  to be put aside for now.
 *
 *  Revision 1.2  2001/03/09 11:03:15  mbrown
 *  implemented queue_command.  All that's left is the dispatch
 *  function, /proc stuff, and cleanup.  Then its on to help
 *  mostman and jhawkins with the pass-through target.
 *
 *  Revision 1.1  2001/03/04 10:24:43  mbrown
 *  initial revision.  Doesn't compile but source here might be
 *  useful for Mike and Josh.
 *
 *
 *
 *  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, 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.
 *
 */

/* Credits:
 *
 * Some of this code was copied and or modified from sym53c416.c and 
 * Alan Cox's Linux Gear articles on SCSI drivers:
 *
 * http://www.linux-mag.com/1999-08/gear_01.html
 * http://www.linux-mag.com/1999-09/gear_01.html
 */


#include <linux/config.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/socket.h>
#include <linux/uio.h>
#include <linux/kdev_t.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/net.h>
#include <linux/sched.h>
#include <linux/tcp.h>
#include <linux/skbuff.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/spinlock.h>
#include <linux/blkdev.h>
#include <linux/blk.h>
#include <linux/init.h>

#include <linux/byteorder/generic.h>

#include <asm/processor.h>
#include <asm/scatterlist.h>

#include <net/sock.h>

#include "scsi.h"
#include "scsi_obsolete.h"
#include "sd.h"
#include "hosts.h"

#include "iscsi.h"
#include "iscsi_client.h"


static void DUMP_DATA (void *start, int len)
{
        int i;
        unsigned char *tmp = start;


        for (i=0; i<len; i++) {
                if ((i % 4) == 0) {
                        printk ("\n\t0x");
                }
                printk ("%02x", tmp[i]);
        }

        printk ("\n");
}



#define ISCSI_MAX_CONNECTIONS    1
#define ISCSI_MAX_SESSIONS       1

typedef struct iscsi_session_t iscsi_session_t;

typedef struct iscsi_connection_t {
        iscsi_session_t *s;
        
        struct socket *sock;
        u16 in_use;
        u32 cid;
        u32 stat_rn;

        pid_t reader;
} iscsi_connection_t;

struct iscsi_session_t {
        struct iscsi_connection_t connection[ISCSI_MAX_CONNECTIONS];
        u32 num_connections;
        u16 in_use;
        u16 isid;
        u16 tsid;
        u32 itt;
        u32 cmd_rn;
        u32 max_cmd_rn;
        /* this should eventually be a queue */
        Scsi_Cmnd *current_command;
};


#define ASSERT(cond) { if (!(cond)) { printk ("iscsi_client - ASSERT FAILED " \
                       "%s:%d\n", __FILE__, __LINE__); } }

static __inline void iscsi_close_connection (iscsi_connection_t *c) {
        sock_release (c->sock);
}

/* Local prototypes */
static unsigned int iscsi_client_probe(void);
static int iscsi_client_start (iscsi_session_t *s);
static int iscsi_client_login(iscsi_session_t *s, u16 c_idx);
static int iscsi_client_reader(void *connection);
static int iscsi_client_dispatch (iscsi_connection_t *c, iscsi_header_t hdr, s32 bytes_to_read);
static void iscsi_client_it_finished(Scsi_Cmnd * SCpnt);
static int iscsi_client_release(struct Scsi_Host *SChost);

/* iSCSI Globals */
static void *scratch_pad = NULL;
static iscsi_session_t session[ISCSI_MAX_SESSIONS];
static u16 isid = 1;


/* Exported definitions */

/* lifted from scsi_debug.c */
/* iscsi_client_proc_info
 * Used if the driver currently has no own support for /proc/scsi
 */

int iscsi_client_proc_info(char *buffer, char **start, off_t offset,
                           int length, int inode, int inout)
{
	int len, pos, begin;
	int orig_length = length;

        // printk ("iscsi_client - PID %d iscsi_client_proc_info(%p,%p,_,%d,%d,%d) ENTRY\n",
//                current->pid, buffer, start, length, inode, inout);

	if (inout == 1) {
		/* First check for the Signature */
		if (length >= 12 && strncmp(buffer, "iscsi_client", 12) == 0) {
			buffer += 13;
			length -= 13;

			if (buffer[length - 1] == '\n') {
				buffer[length - 1] = '\0';
				length--;
			}
			/*
			 * OK, we are getting some kind of command.  Figure out
			 * what we are supposed to do here.  Simulate bus lockups
			 * to test our reset capability.
			 */
			if (length == 4 && strncmp(buffer, "test", length) == 0) {
                                printk("iscsi_client - Recieved test\n");
                                return orig_length;
                        }
			if (length == 6 && strncmp(buffer, "lockup", length) == 0) {
                                printk("iscsi_client - Recieved lockup\n");
				return orig_length;
			}
			if (length == 6 && strncmp(buffer, "unlock", length) == 0) {
                                printk("iscsi_client Recieved unlock\n");
				return orig_length;
			}
			printk("Unknown command:%s (%d)\n", buffer, length);
		} else
			printk("Wrong Signature:%10s\n", (char *) buffer);

		return -EINVAL;

	}
	begin = 0;
	pos = len = sprintf(buffer,
                            "This driver implements the IETF iSCSI draft (SCSI over TCP/IP)\n");
	if (pos < offset) {
		len = 0;
		begin = pos;
	}
	*start = buffer + (offset - begin);	/* Start of wanted data */
	len -= (offset - begin);
	if (len > length)
		len = length;

        // printk ("iscsi_client - PID %d iscsi_client_proc_info(%p,%p,_,%d,%d,%d) EXIT\n",
//                current->pid, buffer, start, length, inode, inout);

	return (len);
}

const char *iscsi_client_info(struct Scsi_Host *SChost)
{
        return ("iSCSI Client Adapter: $Id: iscsi_client.c,v 1.24 2001/04/24 05:49:09 mbrown Exp $");
}

int iscsi_client_detect(Scsi_Host_Template * tpnt)
{
        struct Scsi_Host *shpnt;