Differential D25605 Diff 74258 stand/libsa/geli/gelidev.c

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stand/libsa/geli/gelidev.c

Show First 20 Lines • Show All 109 Lines • ▼ Show 20 Lines	geli_dev_strategy(void devdata, int rw, daddr_t blk, size_t size, char buf,
size_t *rsize)		size_t *rsize)
{		{
struct geli_devdesc *gdesc;		struct geli_devdesc *gdesc;
off_t alnend, alnstart, reqend, reqstart;		off_t alnend, alnstart, reqend, reqstart;
size_t alnsize;		size_t alnsize;
char *iobuf;		char *iobuf;
int rc;		int rc;

/* We only handle reading; no write support. */
if ((rw & F_MASK) != F_READ)
return (EOPNOTSUPP);

gdesc = (struct geli_devdesc *)devdata;		gdesc = (struct geli_devdesc *)devdata;

/*		/*
* We can only decrypt full geli blocks. The blk arg is expressed in		* We can only decrypt full geli blocks. The blk arg is expressed in
* units of DEV_BSIZE blocks, while size is in bytes. Convert		* units of DEV_BSIZE blocks, while size is in bytes. Convert
* everything to bytes, and calculate the geli-blocksize-aligned start		* everything to bytes, and calculate the geli-blocksize-aligned start
* and end points.		* and end points.
*		*
* Note: md_sectorsize must be cast to a signed type for the round2		* Note: md_sectorsize must be cast to a signed type for the round2
* macros to work correctly (otherwise they get zero-extended to 64 bits		* macros to work correctly (otherwise they get zero-extended to 64 bits
* and mask off the high order 32 bits of the requested start/end).		* and mask off the high order 32 bits of the requested start/end).
*/		*/

reqstart = blk * DEV_BSIZE;		reqstart = blk * DEV_BSIZE;
reqend = reqstart + size;		reqend = reqstart + size;
alnstart = rounddown2(reqstart, (int)gdesc->gdev->md.md_sectorsize);		alnstart = rounddown2(reqstart, (int)gdesc->gdev->md.md_sectorsize);
alnend = roundup2(reqend, (int)gdesc->gdev->md.md_sectorsize);		alnend = roundup2(reqend, (int)gdesc->gdev->md.md_sectorsize);
alnsize = alnend - alnstart;		alnsize = alnend - alnstart;

/*		/*
* If alignment requires us to read more than the size of the provided		* If alignment requires us to read/write more than the size of the
* buffer, allocate a temporary buffer.		* provided buffer, allocate a temporary buffer.
		* The writes will always get temporary buffer because of encryption.
*/		*/
if (alnsize <= size)		if (alnsize <= size && (rw & F_MASK) == F_READ)
iobuf = buf;		iobuf = buf;
else if ((iobuf = malloc(alnsize)) == NULL)		else if ((iobuf = malloc(alnsize)) == NULL)
return (ENOMEM);		return (ENOMEM);

		switch (rw & F_MASK) {
		case F_READ:
/*		/*
* Read the encrypted data using the host provider, then decrypt it.		* Read the encrypted data using the host provider,
		* then decrypt it.
*/		*/
rc = gdesc->hdesc->dd.d_dev->dv_strategy(gdesc->hdesc, rw,		rc = gdesc->hdesc->dd.d_dev->dv_strategy(gdesc->hdesc, rw,
alnstart / DEV_BSIZE, alnsize, iobuf, NULL);		alnstart / DEV_BSIZE, alnsize, iobuf, NULL);
if (rc != 0)		if (rc != 0)
goto out;		goto out;
rc = geli_read(gdesc->gdev, alnstart, iobuf, alnsize);		rc = geli_io(gdesc->gdev, GELI_DECRYPT, alnstart, iobuf,
		alnsize);
if (rc != 0)		if (rc != 0)
goto out;		goto out;

/*		/*
* If we had to use a temporary buffer, copy the requested part of the		* If we had to use a temporary buffer, copy the requested
* data to the caller's buffer.		* part of the data to the caller's buffer.
*/		*/
if (iobuf != buf)		if (iobuf != buf)
memcpy(buf, iobuf + (reqstart - alnstart), size);		memcpy(buf, iobuf + (reqstart - alnstart), size);

if (rsize != NULL)		if (rsize != NULL)
*rsize = size;		*rsize = size;
		break;
		case F_WRITE:
		if (iobuf != buf) {
		/* Read data and decrypt it */
		rpokalaUnsubmitted Done Inline Actions "Need to read/modify/write, so read and decrypt, then modify." rpokala: "Need to read/modify/write, so read and decrypt, then modify."
		rc = gdesc->hdesc->dd.d_dev->dv_strategy(gdesc->hdesc,
		F_READ, alnstart / DEV_BSIZE, alnsize, iobuf, NULL);
		if (rc != 0)
		goto out;
		rc = geli_io(gdesc->gdev, GELI_DECRYPT, alnstart, iobuf,
		alnsize);
		if (rc != 0)
		goto out;
		/* Copy data to iobuf */
		memcpy(iobuf + (reqstart - alnstart), buf, size);
		}

		/* Encrypt and write it. */
		rc = geli_io(gdesc->gdev, GELI_ENCRYPT, alnstart, iobuf,
		alnsize);
		if (rc != 0)
		goto out;
		rc = gdesc->hdesc->dd.d_dev->dv_strategy(gdesc->hdesc,
		rw, alnstart / DEV_BSIZE, alnsize, iobuf, NULL);
		}
out:		out:
if (iobuf != buf)		if (iobuf != buf)
free(iobuf);		free(iobuf);

return (rc);		return (rc);
}		}

static int		static int
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