freebsd-skq/sys/dev/iscsi/initiator/isc_soc.c

/*-
 * Copyright (c) 2005-2008 Daniel Braniss <danny@cs.huji.ac.il>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 */
/*
 | iSCSI
 | $Id: isc_soc.c,v 1.26 2007/05/19 06:09:01 danny Exp danny $
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_iscsi_initiator.h"

#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/ctype.h>
#include <sys/errno.h>
#include <sys/sysctl.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/socketvar.h>
#include <sys/socket.h>
#include <sys/protosw.h>
#include <sys/proc.h>
#include <sys/ioccom.h>
#include <sys/queue.h>
#include <sys/kthread.h>
#include <sys/syslog.h>
#include <sys/mbuf.h>
#include <sys/user.h>

#include <cam/cam.h>
#include <cam/cam_ccb.h>

#include <dev/iscsi/initiator/iscsi.h>
#include <dev/iscsi/initiator/iscsivar.h>

#ifndef NO_USE_MBUF
#define USE_MBUF
#endif

#ifdef USE_MBUF

static int ou_refcnt = 0;

/*
 | function for freeing external storage for mbuf
 */
static void
ext_free(void *a, void *b)
{
     pduq_t *pq = b;

     if(pq->buf != NULL) {
	  debug(3, "ou_refcnt=%d a=%p b=%p", ou_refcnt, a, pq->buf);
	  free(pq->buf, M_ISCSI);
	  pq->buf = NULL;
     }
}

int
isc_sendPDU(isc_session_t *sp, pduq_t *pq)
{
     struct mbuf *mh, **mp;
     pdu_t		*pp = &pq->pdu;
     int		len, error;

     debug_called(8);
     /* 
      | mbuf for the iSCSI header
      */
     MGETHDR(mh, M_TRYWAIT, MT_DATA);
     mh->m_len = mh->m_pkthdr.len = sizeof(union ipdu_u);
     mh->m_pkthdr.rcvif = NULL;
     MH_ALIGN(mh, sizeof(union ipdu_u));
     bcopy(&pp->ipdu, mh->m_data, sizeof(union ipdu_u));
     mh->m_next = NULL;

     if(sp->hdrDigest)
	  pq->pdu.hdr_dig = sp->hdrDigest(&pp->ipdu, sizeof(union ipdu_u), 0);
     if(pp->ahs_len) {
          /* 
	   | Add any AHS to the iSCSI hdr mbuf
           |  XXX Assert: (mh->m_pkthdr.len + pp->ahs_len) < MHLEN
	   */
          bcopy(pp->ahs, (mh->m_data + mh->m_len), pp->ahs_len);
          mh->m_len += pp->ahs_len;
          mh->m_pkthdr.len += pp->ahs_len;

	  if(sp->hdrDigest)
	       pq->pdu.hdr_dig = sp->hdrDigest(&pp->ahs, pp->ahs_len, pq->pdu.hdr_dig);
     }
     if(sp->hdrDigest) {
	  debug(2, "hdr_dig=%x", pq->pdu.hdr_dig);
          /* 
	   | Add header digest to the iSCSI hdr mbuf
	   | XXX Assert: (mh->m_pkthdr.len + 4) < MHLEN
	   */
          bcopy(&pp->hdr_dig, (mh->m_data + mh->m_len), sizeof(int));
          mh->m_len += sizeof(int);
          mh->m_pkthdr.len += sizeof(int);
     }
     mp = &mh->m_next;
     if(pq->pdu.ds) {
          struct mbuf   *md;
          int           off = 0;

          len = pp->ds_len;
	  while(len & 03) // the specs say it must be int alligned
	       len++;
          while(len > 0) {
                int       l;
          
	       MGET(md, M_TRYWAIT, MT_DATA);
	       md->m_ext.ref_cnt = &ou_refcnt;
                l = min(MCLBYTES, len);
	       debug(5, "setting ext_free(arg=%p len/l=%d/%d)", pq->buf, len, l);
	       MEXTADD(md, pp->ds + off, l, ext_free, pp->ds + off, pq, 0, EXT_EXTREF);
                md->m_len = l;
                md->m_next = NULL;
                mh->m_pkthdr.len += l;
                *mp = md;
                mp = &md->m_next;
                len -= l;
                off += l;
          } 
     }
     if(sp->dataDigest) {
          struct mbuf   *me;

	  pp->ds_dig = sp->dataDigest(pp->ds, pp->ds_len, 0);

          MGET(me, M_TRYWAIT, MT_DATA);
          me->m_len = sizeof(int);
          MH_ALIGN(mh, sizeof(int));
          bcopy(&pp->ds_dig, me->m_data, sizeof(int));
          me->m_next = NULL;
          mh->m_pkthdr.len += sizeof(int);
          *mp = me;
     }
     if((error = sosend(sp->soc, NULL, NULL, mh, 0, 0, sp->td)) != 0) {
	  sdebug(3, "error=%d", error);
	  return error;
     }
     sp->stats.nsent++;
     getbintime(&sp->stats.t_sent);
     return 0;
}
#else /* NO_USE_MBUF */
int
isc_sendPDU(isc_session_t *sp, pduq_t *pq)
{
     struct uio *uio = &pq->uio;
     struct iovec *iv;
     pdu_t	*pp = &pq->pdu;
     int	len, error;

     debug_called(8);

     bzero(uio, sizeof(struct uio));
     uio->uio_rw = UIO_WRITE;
     uio->uio_segflg = UIO_SYSSPACE;
     uio->uio_td = sp->td;
     uio->uio_iov = iv = pq->iov;

     iv->iov_base = &pp->ipdu;
     iv->iov_len = sizeof(union ipdu_u);
     uio->uio_resid = pq->len;
     iv++;
     if(sp->hdrDigest)
	  pq->pdu.hdr_dig = sp->hdrDigest(&pp->ipdu, sizeof(union ipdu_u), 0);
     if(pp->ahs_len) {
	  iv->iov_base = pp->ahs;
	  iv->iov_len = pp->ahs_len;
	  iv++;

	  if(sp->hdrDigest)
	       pq->pdu.hdr_dig = sp->hdrDigest(&pp->ahs, pp->ahs_len, pq->pdu.hdr_dig);
     }
     if(sp->hdrDigest) {
	  debug(2, "hdr_dig=%x", pq->pdu.hdr_dig);
	  iv->iov_base = &pp->hdr_dig;
	  iv->iov_len = sizeof(int);
	  iv++;
     }
     if(pq->pdu.ds) {
	  iv->iov_base = pp->ds;
	  iv->iov_len = pp->ds_len;
	  while(iv->iov_len & 03) // the specs say it must be int alligned
	       iv->iov_len++;
	  iv++;
     }
     if(sp->dataDigest) {
	  pp->ds_dig = sp->dataDigest(pp->ds, pp->ds_len, 0);
	  iv->iov_base = &pp->ds_dig;
	  iv->iov_len = sizeof(int);
	  iv++;
     }
     uio->uio_iovcnt	= iv - pq->iov;
     sdebug(5, "opcode=%x iovcnt=%d uio_resid=%d itt=%x",
	    pp->ipdu.bhs.opcode, uio->uio_iovcnt, uio->uio_resid,
	    ntohl(pp->ipdu.bhs.itt));
     sdebug(5, "sp=%p sp->soc=%p uio=%p sp->td=%p",
	    sp, sp->soc, uio, sp->td);
     do {
	  len = uio->uio_resid;
	  error = sosend(sp->soc, NULL, uio, 0, 0, 0, sp->td);
	  if(uio->uio_resid == 0 || error || len == uio->uio_resid) {
	       if(uio->uio_resid) {
		    sdebug(2, "uio->uio_resid=%d uio->uio_iovcnt=%d error=%d len=%d",
			   uio->uio_resid, uio->uio_iovcnt, error, len);
		    if(error == 0)
			 error = EAGAIN; // 35
	       }
	       break;
	  }
	  /*
	   | XXX: untested code
	   */
	  sdebug(1, "uio->uio_resid=%d uio->uio_iovcnt=%d",
		uio->uio_resid, uio->uio_iovcnt);
	  iv = uio->uio_iov;
	  len -= uio->uio_resid;
	  while(uio->uio_iovcnt > 0) {
	       if(iv->iov_len > len) {
		    caddr_t	bp = (caddr_t)iv->iov_base;

		    iv->iov_len -= len;
		    iv->iov_base = (void *)&bp[len];
		    break;
	       }
	       len -= iv->iov_len;
	       uio->uio_iovcnt--;
	       uio->uio_iov++;
	       iv++;
	  }
     } while(uio->uio_resid);

     if(error == 0) {
	  sp->stats.nsent++;
	  getbintime(&sp->stats.t_sent);

     }

     return error;
}
#endif /* USE_MBUF */

/*
 | wait till a PDU header is received
 | from the socket.
 */
/*
   The format of the BHS is:

   Byte/     0       |       1       |       2       |       3       |
      /              |               |               |               |
     |0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|0 1 2 3 4 5 6 7|
     +---------------+---------------+---------------+---------------+
    0|.|I| Opcode    |F|  Opcode-specific fields                     |
     +---------------+---------------+---------------+---------------+
    4|TotalAHSLength | DataSegmentLength                             |
     +---------------+---------------+---------------+---------------+
    8| LUN or Opcode-specific fields                                 |
     +                                                               +
   12|                                                               |
     +---------------+---------------+---------------+---------------+
   16| Initiator Task Tag                                            |
     +---------------+---------------+---------------+---------------+
   20/ Opcode-specific fields                                        /
    +/                                                               /
     +---------------+---------------+---------------+---------------+
   48
 */
static __inline int
so_getbhs(isc_session_t *sp)
{
     bhs_t *bhs		= &sp->bhs;
     struct uio		*uio = &sp->uio;
     struct iovec	*iov = &sp->iov;
     int		error, flags;

     debug_called(8);

     iov->iov_base	= bhs;
     iov->iov_len	= sizeof(bhs_t);

     uio->uio_iov	= iov;
     uio->uio_iovcnt	= 1;
     uio->uio_rw	= UIO_READ;
     uio->uio_segflg	= UIO_SYSSPACE;
     uio->uio_td	= curthread; // why ...
     uio->uio_resid	= sizeof(bhs_t);

     flags = MSG_WAITALL;
     error = soreceive(sp->soc, NULL, uio, 0, 0, &flags);

     if(error)
	  debug(2, "error=%d so_error=%d uio->uio_resid=%d iov.iov_len=%zd",
		error,
		sp->soc->so_error, uio->uio_resid, iov->iov_len);
     if(!error && (uio->uio_resid > 0)) {
	  error = EPIPE; // was EAGAIN
	  debug(2, "error=%d so_error=%d uio->uio_resid=%d iov.iov_len=%zd so_state=%x",
		error,
		sp->soc->so_error, uio->uio_resid, iov->iov_len, sp->soc->so_state);
     }
	  
     return error;
}

/*
 | so_recv gets called when there is at least
 | an iSCSI header in the queue
 */
static int
so_recv(isc_session_t *sp, pduq_t *pq)
{
     struct socket	*so = sp->soc;
     sn_t		*sn = &sp->sn;
     struct uio		*uio = &pq->uio;
     pdu_t		*pp;
     int		error;
     size_t		n, len;
     bhs_t		*bhs;
     u_int		max, exp;

     debug_called(8);
     /*
      | now calculate how much data should be in the buffer
      | NOTE: digest is not verified/calculated - yet
      */
     pp = &pq->pdu;
     bhs = &pp->ipdu.bhs;

     len = 0;
     if(bhs->AHSLength) {
	  pp->ahs_len = bhs->AHSLength * 4;
	  len += pp->ahs_len;
     }
     if(sp->hdrDigest)
	  len += 4;
     if(bhs->DSLength) {
	  n = bhs->DSLength;
#if BYTE_ORDER == LITTLE_ENDIAN
	  pp->ds_len = ((n & 0x00ff0000) >> 16)
	       | (n & 0x0000ff00)
	       | ((n & 0x000000ff) << 16);
#else
	  pp->ds_len = n;
#endif
	  len += pp->ds_len;
	  while(len & 03)
	       len++;
	  if(sp->dataDigest)
	       len += 4;
     }

     if((sp->opt.maxRecvDataSegmentLength > 0) && (len > sp->opt.maxRecvDataSegmentLength)) {
#if 0
	  xdebug("impossible PDU length(%d) opt.maxRecvDataSegmentLength=%d",
		 len, sp->opt.maxRecvDataSegmentLength);
	  // deep trouble here, probably all we can do is
	  // force a disconnect, XXX: check RFC ...
	  log(LOG_ERR,
	      "so_recv: impossible PDU length(%ld) from iSCSI %s/%s\n",
	      len, sp->opt.targetAddress, sp->opt.targetName);
#endif
	  /*
	   | XXX: this will really screwup the stream.
	   | should clear up the buffer till a valid header
	   | is found, or just close connection ...
	   | should read the RFC.
	   */
	  error = E2BIG;
	  goto out;
     }
     if(len) {
	  int	flags = MSG_WAITALL;
	  struct mbuf **mp;

	  mp = &pq->mp;

	  uio->uio_resid = len;
	  uio->uio_td = curthread; // why ...
	  if(sp->douio) {
	       // it's more efficient to use mbufs -- why?
	       if(bhs->opcode == ISCSI_READ_DATA) {
		    pduq_t	*opq;

		    opq = i_search_hld(sp, pq->pdu.ipdu.bhs.itt, 1);
		    if(opq != NULL) {
			 union ccb *ccb 		= opq->ccb;
			 struct ccb_scsiio *csio	= &ccb->csio;
			 pdu_t *opp			= &opq->pdu;
			 scsi_req_t *cmd		= &opp->ipdu.scsi_req;
			 data_in_t *rcmd		= &pq->pdu.ipdu.data_in;
			 bhs_t *bhp			= &opp->ipdu.bhs;
			 int	r;
			 
			 if(bhp->opcode == ISCSI_SCSI_CMD 
			    && cmd->R
			    && (ntohl(cmd->edtlen) >= pq->pdu.ds_len)) {
			      struct iovec *iov = pq->iov;
			      iov->iov_base = csio->data_ptr + ntohl(rcmd->bo);
			      iov->iov_len = pq->pdu.ds_len;

			      uio->uio_rw = UIO_READ;
			      uio->uio_segflg = UIO_SYSSPACE;
			      uio->uio_iov = iov;
			      uio->uio_iovcnt = 1;
			      if(len > pq->pdu.ds_len) {
				   pq->iov[1].iov_base = &r;
				   pq->iov[1].iov_len = len - pq->pdu.ds_len;
				   uio->uio_iovcnt++;
			      }
			      mp = NULL;
			      
			      sdebug(4, "uio_resid=0x%x itt=0x%x bp=%p bo=%x len=%x/%x",
				     uio->uio_resid,
				     ntohl(pq->pdu.ipdu.bhs.itt),
				     csio->data_ptr, ntohl(rcmd->bo), ntohl(cmd->edtlen), pq->pdu.ds_len);
			 }
		    }
	       }
	  }
	  error = soreceive(so, NULL, uio, mp, NULL, &flags);
	  //if(error == EAGAIN)
	  // XXX: this needs work! it hangs iscontrol
	  if(error || uio->uio_resid)
	       goto out;
     }
     pq->len += len;
     sdebug(6, "len=%d] opcode=0x%x ahs_len=0x%x ds_len=0x%x",
	    pq->len, bhs->opcode, pp->ahs_len, pp->ds_len);

     max = ntohl(bhs->MaxCmdSN);
     exp = ntohl(bhs->ExpStSN);

     if(max < exp - 1 &&
	max > exp - _MAXINCR) {
	  sdebug(2,  "bad cmd window size");
	  error = EIO; // XXX: for now;
	  goto out; // error
     }

     if(SNA_GT(max, sn->maxCmd))
	  sn->maxCmd = max;

     if(SNA_GT(exp, sn->expCmd))
	  sn->expCmd = exp;

     sp->cws = sn->maxCmd - sn->expCmd + 1;

     return 0;

 out:
     // XXX: need some work here
     xdebug("have a problem, error=%d", error);
     pdu_free(sp->isc, pq);
     if(!error && uio->uio_resid > 0)
	  error = EPIPE;
     return error;
}

/*
 | wait for something to arrive.
 | and if the pdu is without errors, process it.
 */
static int
so_input(isc_session_t *sp)
{
     pduq_t		*pq;
     int		error;

     debug_called(8);
     /*
      | first read in the iSCSI header
      */
     error = so_getbhs(sp);
     if(error == 0) {
	  /*
	   | now read the rest.
	   */
	  pq = pdu_alloc(sp->isc, M_NOWAIT); 
	  if(pq == NULL) { // XXX: might cause a deadlock ...
	       debug(3, "out of pdus, wait");
	       pq = pdu_alloc(sp->isc, M_NOWAIT);  // OK to WAIT
	  }
	  pq->pdu.ipdu.bhs = sp->bhs;
	  pq->len = sizeof(bhs_t);	// so far only the header was read
	  error = so_recv(sp, pq);
	  if(error != 0) {
	       error += 0x800; // XXX: just to see the error.
	       // terminal error
	       // XXX: close connection and exit
	  }
	  else {
	       sp->stats.nrecv++;
	       getbintime(&sp->stats.t_recv);
	       ism_recv(sp, pq);
	  }
     }
     return error;
}

/*
 | one per active (connected) session.
 | this thread is responsible for reading
 | in packets from the target.
 */
static void
isc_soc(void *vp)
{
     isc_session_t	*sp = (isc_session_t *)vp;
     struct socket	*so = sp->soc;
     int		error;

     debug_called(8);

     sp->flags |= ISC_CON_RUNNING;
     if(sp->cam_path)
	  ic_release(sp);

     error = 0;
     while((sp->flags & (ISC_CON_RUN | ISC_LINK_UP)) == (ISC_CON_RUN | ISC_LINK_UP)) {
	  // XXX: hunting ...
	  if(sp->soc == NULL || !(so->so_state & SS_ISCONNECTED)) {
	       debug(2, "sp->soc=%p", sp->soc);
	       break;
	  }
	  error = so_input(sp);
	  if(error == 0) {
	       mtx_lock(&sp->io_mtx);
	       if(sp->flags & ISC_OWAITING) {
	       wakeup(&sp->flags);
	       }
	       mtx_unlock(&sp->io_mtx);
	  } else if(error == EPIPE) {
	       break;
	  }
	  else if(error == EAGAIN) {
	       if(so->so_state & SS_ISCONNECTED) 
		    // there seems to be a problem in 6.0 ...
		    tsleep(sp, PRIBIO, "isc_soc", 2*hz);
	  }
     }
     sdebug(2, "terminated, flags=%x so_count=%d so_state=%x error=%d proc=%p",
	    sp->flags, so->so_count, so->so_state, error, sp->proc);
     if((sp->proc != NULL) && sp->signal) {
	  PROC_LOCK(sp->proc);
	  psignal(sp->proc, sp->signal);
	  PROC_UNLOCK(sp->proc);
	  sp->flags |= ISC_SIGNALED;
	  sdebug(2, "pid=%d signaled(%d)", sp->proc->p_pid, sp->signal);
     }
     else {
	  // we have to do something ourselves
	  // like closing this session ...
     }
     /*
      | we've been terminated
      */
     // do we need this mutex ...?
     mtx_lock(&sp->io_mtx);
     sp->flags &= ~(ISC_CON_RUNNING | ISC_LINK_UP);
     wakeup(&sp->soc);
     mtx_unlock(&sp->io_mtx);

     sdebug(2, "dropped ISC_CON_RUNNING");

     kproc_exit(0);
}

void
isc_stop_receiver(isc_session_t *sp)
{
     int	n;

     debug_called(8);
     sdebug(3, "sp=%p sp->soc=%p", sp, sp? sp->soc: 0);
     mtx_lock(&sp->io_mtx);
     sp->flags &= ~ISC_LINK_UP;
     msleep(&sp->soc, &sp->io_mtx, PRIBIO|PDROP, "isc_stpc", 5*hz);

     soshutdown(sp->soc, SHUT_RD);

     mtx_lock(&sp->io_mtx);
     sdebug(3, "soshutdown");
     sp->flags &= ~ISC_CON_RUN;
     n = 2;
     while(n-- && (sp->flags & ISC_CON_RUNNING)) {
	  sdebug(3, "waiting n=%d... flags=%x", n, sp->flags);
	  msleep(&sp->soc, &sp->io_mtx, PRIBIO, "isc_stpc", 5*hz);
     }
     mtx_unlock(&sp->io_mtx);


     if(sp->fp != NULL)
	  fdrop(sp->fp, sp->td);
     fputsock(sp->soc);
     sp->soc = NULL;
     sp->fp = NULL;

     sdebug(3, "done");
}

void
isc_start_receiver(isc_session_t *sp)
{
     debug_called(8);

     sp->flags |= ISC_CON_RUN | ISC_LINK_UP;

     kproc_create(isc_soc, sp, &sp->soc_proc, 0, 0, "iscsi%d", sp->sid);
}