/*
* _mem_fr_sds moves data into user memory from a secondary data segment (SDS).
*
* Returns 0 on normal return, or else -1 with error code in errno.
*/
_mem_fr_sds(
bitptr ubuf, /* user buffer to receive data */
bitptr sdsaddr, /* SDS bit address of data */
int nbits /* number of bits to move */
)
{
long sds_bit_offset;
char *ucaddr;
long *uwaddr;
int ret;
if (nbits & (BITPBLOCK - 1)) {
errno = FDC_ERR_GRAN; /* must be block multiple */
return -1;
}
ucaddr = BPTR2CP(ubuf);
uwaddr = BPTR2WP(ubuf);
if (ucaddr != (char*)uwaddr) {
errno = FDC_ERR_SDSWB; /* must be word-aligned */
return -1;
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
if (sds_bit_offset & (BITPBLOCK - 1)) {
errno = FDC_ERR_GRAN; /* must be block multiple */
return -1;
}
ret = ssread(uwaddr, BITS2BLOCKS(sds_bit_offset), BITS2BLOCKS(nbits));
if (ret == -1)
errno = FDC_ERR_SDSIO;
return ret;
}
if (do_cksum) {
if (do_byteswap)
fletcher_4_incremental_byteswap(buf, len, cksum);
else
fletcher_4_incremental_native(buf, len, cksum);
}
total_stream_len += len;
return (outlen);
}
static size_t
read_hdr(dmu_replay_record_t *drr, zio_cksum_t *cksum)
{
ASSERT3U(offsetof(dmu_replay_record_t, drr_u.drr_checksum.drr_checksum),
==, sizeof (dmu_replay_record_t) - sizeof (zio_cksum_t));
size_t r = ssread(drr, sizeof (*drr) - sizeof (zio_cksum_t), cksum);
if (r == 0)
return (0);
zio_cksum_t saved_cksum = *cksum;
r = ssread(&drr->drr_u.drr_checksum.drr_checksum,
sizeof (zio_cksum_t), cksum);
if (r == 0)
return (0);
if (!ZIO_CHECKSUM_IS_ZERO(&drr->drr_u.drr_checksum.drr_checksum) &&
!ZIO_CHECKSUM_EQUAL(saved_cksum,
drr->drr_u.drr_checksum.drr_checksum)) {
fprintf(stderr, "invalid checksum\n");
(void) printf("Incorrect checksum in record header.\n");
(void) printf("Expected checksum = %llx/%llx/%llx/%llx\n",
saved_cksum.zc_word[0],
saved_cksum.zc_word[1],
int
main(int argc, char *argv[])
{
char *buf = malloc(INITIAL_BUFLEN);
dmu_replay_record_t thedrr;
dmu_replay_record_t *drr = &thedrr;
struct drr_begin *drrb = &thedrr.drr_u.drr_begin;
struct drr_end *drre = &thedrr.drr_u.drr_end;
struct drr_object *drro = &thedrr.drr_u.drr_object;
struct drr_freeobjects *drrfo = &thedrr.drr_u.drr_freeobjects;
struct drr_write *drrw = &thedrr.drr_u.drr_write;
struct drr_write_byref *drrwbr = &thedrr.drr_u.drr_write_byref;
struct drr_free *drrf = &thedrr.drr_u.drr_free;
struct drr_spill *drrs = &thedrr.drr_u.drr_spill;
char c;
boolean_t verbose = B_FALSE;
boolean_t first = B_TRUE;
int err;
zio_cksum_t zc = { 0 };
zio_cksum_t pcksum = { 0 };
while ((c = getopt(argc, argv, ":vC")) != -1) {
switch (c) {
case 'C':
do_cksum = B_FALSE;
break;
case 'v':
verbose = B_TRUE;
break;
case ':':
(void) fprintf(stderr,
"missing argument for '%c' option\n", optopt);
usage();
break;
case '?':
(void) fprintf(stderr, "invalid option '%c'\n",
optopt);
usage();
}
}
if (isatty(STDIN_FILENO)) {
(void) fprintf(stderr,
"Error: Backup stream can not be read "
"from a terminal.\n"
"You must redirect standard input.\n");
exit(1);
}
send_stream = stdin;
pcksum = zc;
while (ssread(drr, sizeof (dmu_replay_record_t), &zc)) {
if (first) {
if (drrb->drr_magic == BSWAP_64(DMU_BACKUP_MAGIC)) {
do_byteswap = B_TRUE;
if (do_cksum) {
ZIO_SET_CHECKSUM(&zc, 0, 0, 0, 0);
/*
* recalculate header checksum now
* that we know it needs to be
* byteswapped.
*/
fletcher_4_incremental_byteswap(drr,
sizeof (dmu_replay_record_t), &zc);
}
} else if (drrb->drr_magic != DMU_BACKUP_MAGIC) {
(void) fprintf(stderr, "Invalid stream "
"(bad magic number)\n");
exit(1);
}
first = B_FALSE;
}
if (do_byteswap) {
drr->drr_type = BSWAP_32(drr->drr_type);
drr->drr_payloadlen =
BSWAP_32(drr->drr_payloadlen);
}
/*
* At this point, the leading fields of the replay record
* (drr_type and drr_payloadlen) have been byte-swapped if
* necessary, but the rest of the data structure (the
* union of type-specific structures) is still in its
* original state.
*/
if (drr->drr_type >= DRR_NUMTYPES) {
(void) printf("INVALID record found: type 0x%x\n",
drr->drr_type);
(void) printf("Aborting.\n");
exit(1);
}
drr_record_count[drr->drr_type]++;
switch (drr->drr_type) {
case DRR_BEGIN:
if (do_byteswap) {
drrb->drr_magic = BSWAP_64(drrb->drr_magic);
drrb->drr_versioninfo =
BSWAP_64(drrb->drr_versioninfo);
drrb->drr_creation_time =
BSWAP_64(drrb->drr_creation_time);
drrb->drr_type = BSWAP_32(drrb->drr_type);
drrb->drr_flags = BSWAP_32(drrb->drr_flags);
drrb->drr_toguid = BSWAP_64(drrb->drr_toguid);
drrb->drr_fromguid =
BSWAP_64(drrb->drr_fromguid);
}
(void) printf("BEGIN record\n");
(void) printf("\thdrtype = %lld\n",
DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo));
(void) printf("\tfeatures = %llx\n",
DMU_GET_FEATUREFLAGS(drrb->drr_versioninfo));
(void) printf("\tmagic = %llx\n",
(u_longlong_t)drrb->drr_magic);
(void) printf("\tcreation_time = %llx\n",
(u_longlong_t)drrb->drr_creation_time);
(void) printf("\ttype = %u\n", drrb->drr_type);
(void) printf("\tflags = 0x%x\n", drrb->drr_flags);
(void) printf("\ttoguid = %llx\n",
(u_longlong_t)drrb->drr_toguid);
(void) printf("\tfromguid = %llx\n",
(u_longlong_t)drrb->drr_fromguid);
(void) printf("\ttoname = %s\n", drrb->drr_toname);
if (verbose)
(void) printf("\n");
if ((DMU_GET_STREAM_HDRTYPE(drrb->drr_versioninfo) ==
DMU_COMPOUNDSTREAM) && drr->drr_payloadlen != 0) {
nvlist_t *nv;
int sz = drr->drr_payloadlen;
if (sz > 1<<20) {
free(buf);
buf = malloc(sz);
}
(void) ssread(buf, sz, &zc);
if (ferror(send_stream))
perror("fread");
err = nvlist_unpack(buf, sz, &nv, 0);
if (err)
perror(strerror(err));
nvlist_print(stdout, nv);
nvlist_free(nv);
}
break;
case DRR_END:
if (do_byteswap) {
drre->drr_checksum.zc_word[0] =
BSWAP_64(drre->drr_checksum.zc_word[0]);
drre->drr_checksum.zc_word[1] =
BSWAP_64(drre->drr_checksum.zc_word[1]);
drre->drr_checksum.zc_word[2] =
BSWAP_64(drre->drr_checksum.zc_word[2]);
drre->drr_checksum.zc_word[3] =
BSWAP_64(drre->drr_checksum.zc_word[3]);
}
/*
* We compare against the *previous* checksum
* value, because the stored checksum is of
* everything before the DRR_END record.
*/
if (do_cksum && !ZIO_CHECKSUM_EQUAL(drre->drr_checksum,
pcksum)) {
(void) printf("Expected checksum differs from "
"checksum in stream.\n");
(void) printf("Expected checksum = %"
FX64 "/%" FX64 "/%" FX64 "/%" FX64 "\n",
pcksum.zc_word[0],
pcksum.zc_word[1],
pcksum.zc_word[2],
pcksum.zc_word[3]);
}
(void) printf("END checksum = %" FX64 "/%" FX64 "/%" FX64 "/%" FX64 "\n",
drre->drr_checksum.zc_word[0],
drre->drr_checksum.zc_word[1],
drre->drr_checksum.zc_word[2],
drre->drr_checksum.zc_word[3]);
ZIO_SET_CHECKSUM(&zc, 0, 0, 0, 0);
break;
case DRR_OBJECT:
if (do_byteswap) {
drro->drr_object = BSWAP_64(drro->drr_object);
drro->drr_type = BSWAP_32(drro->drr_type);
drro->drr_bonustype =
BSWAP_32(drro->drr_bonustype);
drro->drr_blksz = BSWAP_32(drro->drr_blksz);
drro->drr_bonuslen =
BSWAP_32(drro->drr_bonuslen);
drro->drr_toguid = BSWAP_64(drro->drr_toguid);
}
if (verbose) {
(void) printf("OBJECT object = %llu type = %u "
"bonustype = %u blksz = %u bonuslen = %u\n",
(u_longlong_t)drro->drr_object,
drro->drr_type,
drro->drr_bonustype,
drro->drr_blksz,
drro->drr_bonuslen);
}
if (drro->drr_bonuslen > 0) {
(void) ssread(buf, P2ROUNDUP(drro->drr_bonuslen,
8), &zc);
}
break;
case DRR_FREEOBJECTS:
if (do_byteswap) {
drrfo->drr_firstobj =
BSWAP_64(drrfo->drr_firstobj);
drrfo->drr_numobjs =
BSWAP_64(drrfo->drr_numobjs);
drrfo->drr_toguid = BSWAP_64(drrfo->drr_toguid);
}
if (verbose) {
(void) printf("FREEOBJECTS firstobj = %llu "
"numobjs = %llu\n",
(u_longlong_t)drrfo->drr_firstobj,
(u_longlong_t)drrfo->drr_numobjs);
}
break;
case DRR_WRITE:
if (do_byteswap) {
drrw->drr_object = BSWAP_64(drrw->drr_object);
drrw->drr_type = BSWAP_32(drrw->drr_type);
drrw->drr_offset = BSWAP_64(drrw->drr_offset);
drrw->drr_length = BSWAP_64(drrw->drr_length);
drrw->drr_toguid = BSWAP_64(drrw->drr_toguid);
drrw->drr_key.ddk_prop =
BSWAP_64(drrw->drr_key.ddk_prop);
}
if (verbose) {
(void) printf("WRITE object = %llu type = %u "
"checksum type = %u\n"
"offset = %llu length = %llu "
"props = %llx\n",
(u_longlong_t)drrw->drr_object,
drrw->drr_type,
drrw->drr_checksumtype,
(u_longlong_t)drrw->drr_offset,
(u_longlong_t)drrw->drr_length,
(u_longlong_t)drrw->drr_key.ddk_prop);
}
(void) ssread(buf, drrw->drr_length, &zc);
total_write_size += drrw->drr_length;
break;
case DRR_WRITE_BYREF:
if (do_byteswap) {
drrwbr->drr_object =
BSWAP_64(drrwbr->drr_object);
drrwbr->drr_offset =
BSWAP_64(drrwbr->drr_offset);
drrwbr->drr_length =
BSWAP_64(drrwbr->drr_length);
drrwbr->drr_toguid =
BSWAP_64(drrwbr->drr_toguid);
drrwbr->drr_refguid =
BSWAP_64(drrwbr->drr_refguid);
drrwbr->drr_refobject =
BSWAP_64(drrwbr->drr_refobject);
drrwbr->drr_refoffset =
BSWAP_64(drrwbr->drr_refoffset);
drrwbr->drr_key.ddk_prop =
BSWAP_64(drrwbr->drr_key.ddk_prop);
}
if (verbose) {
(void) printf("WRITE_BYREF object = %llu "
"checksum type = %u props = %llx\n"
"offset = %llu length = %llu\n"
"toguid = %llx refguid = %llx\n"
"refobject = %llu refoffset = %llu\n",
(u_longlong_t)drrwbr->drr_object,
drrwbr->drr_checksumtype,
(u_longlong_t)drrwbr->drr_key.ddk_prop,
(u_longlong_t)drrwbr->drr_offset,
(u_longlong_t)drrwbr->drr_length,
(u_longlong_t)drrwbr->drr_toguid,
(u_longlong_t)drrwbr->drr_refguid,
(u_longlong_t)drrwbr->drr_refobject,
(u_longlong_t)drrwbr->drr_refoffset);
}
break;
case DRR_FREE:
if (do_byteswap) {
drrf->drr_object = BSWAP_64(drrf->drr_object);
drrf->drr_offset = BSWAP_64(drrf->drr_offset);
drrf->drr_length = BSWAP_64(drrf->drr_length);
}
if (verbose) {
(void) printf("FREE object = %llu "
"offset = %llu length = %lld\n",
(u_longlong_t)drrf->drr_object,
(u_longlong_t)drrf->drr_offset,
(longlong_t)drrf->drr_length);
}
break;
case DRR_SPILL:
if (do_byteswap) {
drrs->drr_object = BSWAP_64(drrs->drr_object);
drrs->drr_length = BSWAP_64(drrs->drr_length);
}
if (verbose) {
(void) printf("SPILL block for object = %" FU64
"length = %" FU64 "\n", drrs->drr_object,
drrs->drr_length);
}
(void) ssread(buf, drrs->drr_length, &zc);
break;
}
pcksum = zc;
}
free(buf);
/* Print final summary */
(void) printf("SUMMARY:\n");
(void) printf("\tTotal DRR_BEGIN records = %lld\n",
(u_longlong_t)drr_record_count[DRR_BEGIN]);
(void) printf("\tTotal DRR_END records = %lld\n",
(u_longlong_t)drr_record_count[DRR_END]);
(void) printf("\tTotal DRR_OBJECT records = %lld\n",
(u_longlong_t)drr_record_count[DRR_OBJECT]);
(void) printf("\tTotal DRR_FREEOBJECTS records = %lld\n",
(u_longlong_t)drr_record_count[DRR_FREEOBJECTS]);
(void) printf("\tTotal DRR_WRITE records = %lld\n",
(u_longlong_t)drr_record_count[DRR_WRITE]);
(void) printf("\tTotal DRR_FREE records = %lld\n",
(u_longlong_t)drr_record_count[DRR_FREE]);
(void) printf("\tTotal DRR_SPILL records = %lld\n",
(u_longlong_t)drr_record_count[DRR_SPILL]);
(void) printf("\tTotal records = %lld\n",
(u_longlong_t)(drr_record_count[DRR_BEGIN] +
drr_record_count[DRR_OBJECT] +
drr_record_count[DRR_FREEOBJECTS] +
drr_record_count[DRR_WRITE] +
drr_record_count[DRR_FREE] +
drr_record_count[DRR_SPILL] +
drr_record_count[DRR_END]));
(void) printf("\tTotal write size = %lld (0x%llx)\n",
(u_longlong_t)total_write_size, (u_longlong_t)total_write_size);
(void) printf("\tTotal stream length = %lld (0x%llx)\n",
(u_longlong_t)total_stream_len, (u_longlong_t)total_stream_len);
return (0);
}
/*
* _any_sds_fr_mem moves data into a secondary data segment (SDS) from
* user memory
*
* unlike _sds_fr_mem, _any_sds_fr_mem handles moving a number of bits that
* may not be a multiple of 512.
*
* Returns 0 on normal return, or else -1 with error code in errno.
*/
_any_sds_fr_mem(
bitptr sdsaddr, /* SDS bit address of data */
bitptr ubuf, /* user buffer to receive data */
int nbits /* number of bits to move */
)
{
int sds_bit_offset;
int sds_bit_offset_blk;
int rbits;
char localbuf[BYTPBLOCK];
bitptr locptr;
long *uwaddr;
char *ucaddr;
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
if (sds_bit_offset & (BITPBLOCK -1)) {
/* The sds address is not on a block boundary. */
/* Read data from sds to a local buffer. Copy the */
/* user's memory to the appropriate part of the local */
/* buffer, and write it back out to sds. */
sds_bit_offset_blk = (sds_bit_offset & ~(BITPBLOCK - 1));
if (ssread((int *)localbuf, BITS2BLOCKS(sds_bit_offset_blk), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
rbits = MIN(nbits, BITPBLOCK - (sds_bit_offset -
sds_bit_offset_blk));
locptr = CPTR2BP(localbuf);
SET_BPTR(locptr, INC_BPTR(locptr, sds_bit_offset - sds_bit_offset_blk));
MOV_BITS(locptr, ubuf, rbits);
SET_BPTR(ubuf, INC_BPTR(ubuf, rbits));
nbits -= rbits;
if(sswrite((int *)localbuf, BITS2BLOCKS(sds_bit_offset_blk), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, rbits));
if (nbits == 0)
return(0);
assert(((SUBT_BPTR(sdsaddr, WPTR2BP(0))) & (BITPBLOCK -1)) == 0);
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
uwaddr = BPTR2WP(ubuf);
ucaddr = BPTR2CP(ubuf);
if ((nbits & (BITPBLOCK-1)) || (ucaddr != (char *)uwaddr)){
int left;
locptr = CPTR2BP(localbuf);
/* round down nbits to a block boundary */
rbits = nbits & ~(BITPBLOCK-1);
if (rbits) {
if (ucaddr != (char*)uwaddr) {
/* ubuf is not word aligned. */
left = rbits;
sds_bit_offset_blk = BITS2BLOCKS(sds_bit_offset);
while (left > 0) {
if( ssread((int *)localbuf,
sds_bit_offset_blk, 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
MOV_BITS(locptr, ubuf, BITPBLOCK);
SET_BPTR(ubuf, INC_BPTR(ubuf, BITPBLOCK));
if( sswrite((int *)localbuf,
sds_bit_offset_blk, 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, BITPBLOCK));
sds_bit_offset_blk++;
left-= BITPBLOCK;
}
}
else {
if (_sds_fr_mem(sdsaddr, ubuf, rbits) == -1) {
return(-1);
}
SET_BPTR(ubuf, INC_BPTR(ubuf, rbits));
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, rbits));
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
}
/* Get last block into local memory. Merge in user's memory */
/* and write it back out to sds. */
if( ssread((int *)localbuf, BITS2BLOCKS(sds_bit_offset), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
MOV_BITS(locptr, ubuf, nbits - rbits);
if( sswrite((int *)localbuf, BITS2BLOCKS(sds_bit_offset), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
}
else {
if(sswrite(uwaddr, BITS2BLOCKS(sds_bit_offset), BITS2BLOCKS(nbits)) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
}
return(0);
}
/*
* _any_mem_fr_sds moves data into user memory from a secondary data segment (SDS).
*
* unlike _mem_fr_sds, _any_mem_fr_sds handles moving a number of bits that
* may not be a multiple of 512.
*
* Returns 0 on normal return, or else -1 with error code in errno.
*/
_any_mem_fr_sds(
bitptr ubuf, /* user buffer to receive data */
bitptr sdsaddr, /* SDS bit address of data */
int nbits /* number of bits to move */
)
{
int sds_bit_offset;
int sds_bit_offset_blk;
int rbits;
char localbuf[BYTPBLOCK];
bitptr locptr;
long *uwaddr;
char *ucaddr;
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
if (sds_bit_offset & (BITPBLOCK -1)) {
/* The sds address is not on a block boundary. */
/* Read data from sds to a local buffer. Copy the */
/* appropriate part of the local buffer to user's memory. */
sds_bit_offset_blk = (sds_bit_offset & ~(BITPBLOCK - 1));
if(ssread((int *)localbuf, BITS2BLOCKS(sds_bit_offset_blk), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
rbits = MIN(nbits, BITPBLOCK - (sds_bit_offset -
sds_bit_offset_blk));
locptr = CPTR2BP(localbuf);
SET_BPTR(locptr, INC_BPTR(locptr, sds_bit_offset - sds_bit_offset_blk));
MOV_BITS(ubuf, locptr, rbits);
SET_BPTR(ubuf, INC_BPTR(ubuf, rbits));
nbits -= rbits;
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, rbits));
if (nbits == 0)
return(0);
/* Verify that our sds address is now on a block boundary */
assert (((SUBT_BPTR(sdsaddr, WPTR2BP(0))) & (BITPBLOCK -1)) == 0);
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
uwaddr = BPTR2WP(ubuf);
ucaddr = BPTR2CP(ubuf);
if ((nbits & (BITPBLOCK-1)) || (ucaddr != (char *)uwaddr)){
int left;
/* Either we are not reading in a multiple of blocks or */
/* the user's address is not word-aligned. */
/* Round nbits down to a block boundary and */
/* move those to user's memory. */
locptr = CPTR2BP(localbuf);
rbits = nbits & ~(BITPBLOCK-1);
if (rbits) {
if (ucaddr != (char*)uwaddr) {
/* ubuf is not word aligned. */
/* Read the data from sds into a local */
/* buffer and copy to the user's memory */
left = rbits;
sds_bit_offset_blk = BITS2BLOCKS(sds_bit_offset);
while (left > 0) {
if (ssread((int *)localbuf,
sds_bit_offset_blk, 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
MOV_BITS(ubuf, locptr, BITPBLOCK);
SET_BPTR(ubuf, INC_BPTR(ubuf, BITPBLOCK));
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, BITPBLOCK));
sds_bit_offset_blk++;
left-= BITPBLOCK;
}
}
else {
if (ssread(uwaddr, BITS2BLOCKS(sds_bit_offset),
BITS2BLOCKS(rbits)) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
SET_BPTR(ubuf, INC_BPTR(ubuf, rbits));
SET_BPTR(sdsaddr, INC_BPTR(sdsaddr, rbits));
}
sds_bit_offset = SUBT_BPTR(sdsaddr, WPTR2BP(0));
}
/* get last block into local memory and */
/* transfer to user's memory */
if (ssread((int *)localbuf, BITS2BLOCKS(sds_bit_offset), 1) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
assert((nbits - rbits) < BITPBLOCK);
MOV_BITS(ubuf, locptr, nbits - rbits);
}
else {
if(ssread(uwaddr, BITS2BLOCKS(sds_bit_offset), BITS2BLOCKS(nbits)) == -1) {
errno = FDC_ERR_SDSIO;
return(-1);
}
}
return(0);
}
_sdsset_any(
int byte_offset, /* Byte offset into SDS area */
int value, /* Value to which all bytes should be set */
int nbytes) /* Number of bytes to set */
{
#define _BUFFER_BLOCKS 10
char bytebuf[_BUFFER_BLOCKS * BYTPBLOCK]; /* must be word-aligned */
int nblocks;
int blk_offset;
int ret;
int this_chunk;
int left;
int lblk_offset;
int headbytes,tailbytes;
int orig_byte_offset;
orig_byte_offset = byte_offset;
nblocks = BYTES2BLOCKS(nbytes);
blk_offset = BYTES2BLOCKS(byte_offset);
/* if byte_offset is not on a block boundary */
if ((byte_offset) & (BYTPBLOCK - 1)) {
headbytes = BYTPBLOCK - (byte_offset & (BYTPBLOCK -1 ));
if (headbytes > nbytes)
headbytes = nbytes;
ret = ssread(bytebuf, blk_offset, 1);
if (ret == -1) {
errno = FDC_ERR_SDSIO;
return -1;
}
memset(bytebuf + (byte_offset & (BYTPBLOCK-1)), value, headbytes);
ret = sswrite(bytebuf, blk_offset, 1);
if (ret == -1) {
errno = FDC_ERR_SDSIO;
return -1;
}
nbytes -= headbytes;
nblocks = BYTES2BLOCKS(nbytes);
byte_offset += headbytes;
blk_offset = BYTES2BLOCKS(byte_offset);
}
if (nbytes & (BYTPBLOCK - 1)){
/* these will be the bytes left over at the end */
tailbytes = nbytes & (BYTPBLOCK - 1);
lblk_offset = BYTES2BLOCKS(byte_offset + nbytes -1);
ret = ssread(bytebuf, lblk_offset, 1);
if (ret == -1) {
errno = FDC_ERR_SDSIO;
return -1;
}
memset(bytebuf, value, tailbytes);
ret = sswrite(bytebuf, lblk_offset, 1);
if (ret == -1) {
errno = FDC_ERR_SDSIO;
return -1;
}
nbytes -= tailbytes;
}
if (nbytes & (BYTPBLOCK -1 )){
abort();
}
(void)memset(bytebuf, value, MIN(nblocks, _BUFFER_BLOCKS) * BYTPBLOCK);
left = nblocks;
while (left > 0) {
this_chunk = MIN(left, _BUFFER_BLOCKS);
ret = sswrite((long)bytebuf, blk_offset, this_chunk);
if (ret == -1) {
errno = FDC_ERR_SDSIO;
return -1;
}
left -= this_chunk;
blk_offset += this_chunk;
}
return orig_byte_offset;
}