freebsd-nq/lib/isc/buffer.c
2012-04-04 23:11:25 +00:00

490 lines
10 KiB
C

/*
* Copyright (C) 2004-2008 Internet Systems Consortium, Inc. ("ISC")
* Copyright (C) 1998-2002 Internet Software Consortium.
*
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
* REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
* INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
* OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/
/* $Id: buffer.c,v 1.49 2008/09/25 04:02:39 tbox Exp $ */
/*! \file */
#include <config.h>
#include <isc/buffer.h>
#include <isc/mem.h>
#include <isc/region.h>
#include <isc/string.h>
#include <isc/util.h>
void
isc__buffer_init(isc_buffer_t *b, const void *base, unsigned int length) {
/*
* Make 'b' refer to the 'length'-byte region starting at 'base'.
* XXXDCL see the comment in buffer.h about base being const.
*/
REQUIRE(b != NULL);
ISC__BUFFER_INIT(b, base, length);
}
void
isc__buffer_initnull(isc_buffer_t *b) {
/*
* Initialize a new buffer which has no backing store. This can
* later be grown as needed and swapped in place.
*/
ISC__BUFFER_INIT(b, NULL, 0);
}
void
isc_buffer_reinit(isc_buffer_t *b, void *base, unsigned int length) {
/*
* Re-initialize the buffer enough to reconfigure the base of the
* buffer. We will swap in the new buffer, after copying any
* data we contain into the new buffer and adjusting all of our
* internal pointers.
*
* The buffer must not be smaller than the length of the original
* buffer.
*/
REQUIRE(b->length <= length);
REQUIRE(base != NULL);
(void)memmove(base, b->base, b->length);
b->base = base;
b->length = length;
}
void
isc__buffer_invalidate(isc_buffer_t *b) {
/*
* Make 'b' an invalid buffer.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(!ISC_LINK_LINKED(b, link));
REQUIRE(b->mctx == NULL);
ISC__BUFFER_INVALIDATE(b);
}
void
isc__buffer_region(isc_buffer_t *b, isc_region_t *r) {
/*
* Make 'r' refer to the region of 'b'.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
ISC__BUFFER_REGION(b, r);
}
void
isc__buffer_usedregion(isc_buffer_t *b, isc_region_t *r) {
/*
* Make 'r' refer to the used region of 'b'.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
ISC__BUFFER_USEDREGION(b, r);
}
void
isc__buffer_availableregion(isc_buffer_t *b, isc_region_t *r) {
/*
* Make 'r' refer to the available region of 'b'.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
ISC__BUFFER_AVAILABLEREGION(b, r);
}
void
isc__buffer_add(isc_buffer_t *b, unsigned int n) {
/*
* Increase the 'used' region of 'b' by 'n' bytes.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + n <= b->length);
ISC__BUFFER_ADD(b, n);
}
void
isc__buffer_subtract(isc_buffer_t *b, unsigned int n) {
/*
* Decrease the 'used' region of 'b' by 'n' bytes.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used >= n);
ISC__BUFFER_SUBTRACT(b, n);
}
void
isc__buffer_clear(isc_buffer_t *b) {
/*
* Make the used region empty.
*/
REQUIRE(ISC_BUFFER_VALID(b));
ISC__BUFFER_CLEAR(b);
}
void
isc__buffer_consumedregion(isc_buffer_t *b, isc_region_t *r) {
/*
* Make 'r' refer to the consumed region of 'b'.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
ISC__BUFFER_CONSUMEDREGION(b, r);
}
void
isc__buffer_remainingregion(isc_buffer_t *b, isc_region_t *r) {
/*
* Make 'r' refer to the remaining region of 'b'.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
ISC__BUFFER_REMAININGREGION(b, r);
}
void
isc__buffer_activeregion(isc_buffer_t *b, isc_region_t *r) {
/*
* Make 'r' refer to the active region of 'b'.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
ISC__BUFFER_ACTIVEREGION(b, r);
}
void
isc__buffer_setactive(isc_buffer_t *b, unsigned int n) {
/*
* Sets the end of the active region 'n' bytes after current.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->current + n <= b->used);
ISC__BUFFER_SETACTIVE(b, n);
}
void
isc__buffer_first(isc_buffer_t *b) {
/*
* Make the consumed region empty.
*/
REQUIRE(ISC_BUFFER_VALID(b));
ISC__BUFFER_FIRST(b);
}
void
isc__buffer_forward(isc_buffer_t *b, unsigned int n) {
/*
* Increase the 'consumed' region of 'b' by 'n' bytes.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->current + n <= b->used);
ISC__BUFFER_FORWARD(b, n);
}
void
isc__buffer_back(isc_buffer_t *b, unsigned int n) {
/*
* Decrease the 'consumed' region of 'b' by 'n' bytes.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(n <= b->current);
ISC__BUFFER_BACK(b, n);
}
void
isc_buffer_compact(isc_buffer_t *b) {
unsigned int length;
void *src;
/*
* Compact the used region by moving the remaining region so it occurs
* at the start of the buffer. The used region is shrunk by the size
* of the consumed region, and the consumed region is then made empty.
*/
REQUIRE(ISC_BUFFER_VALID(b));
src = isc_buffer_current(b);
length = isc_buffer_remaininglength(b);
(void)memmove(b->base, src, (size_t)length);
if (b->active > b->current)
b->active -= b->current;
else
b->active = 0;
b->current = 0;
b->used = length;
}
isc_uint8_t
isc_buffer_getuint8(isc_buffer_t *b) {
unsigned char *cp;
isc_uint8_t result;
/*
* Read an unsigned 8-bit integer from 'b' and return it.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used - b->current >= 1);
cp = isc_buffer_current(b);
b->current += 1;
result = ((isc_uint8_t)(cp[0]));
return (result);
}
void
isc__buffer_putuint8(isc_buffer_t *b, isc_uint8_t val) {
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + 1 <= b->length);
ISC__BUFFER_PUTUINT8(b, val);
}
isc_uint16_t
isc_buffer_getuint16(isc_buffer_t *b) {
unsigned char *cp;
isc_uint16_t result;
/*
* Read an unsigned 16-bit integer in network byte order from 'b',
* convert it to host byte order, and return it.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used - b->current >= 2);
cp = isc_buffer_current(b);
b->current += 2;
result = ((unsigned int)(cp[0])) << 8;
result |= ((unsigned int)(cp[1]));
return (result);
}
void
isc__buffer_putuint16(isc_buffer_t *b, isc_uint16_t val) {
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + 2 <= b->length);
ISC__BUFFER_PUTUINT16(b, val);
}
void
isc__buffer_putuint24(isc_buffer_t *b, isc_uint32_t val) {
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + 3 <= b->length);
ISC__BUFFER_PUTUINT24(b, val);
}
isc_uint32_t
isc_buffer_getuint32(isc_buffer_t *b) {
unsigned char *cp;
isc_uint32_t result;
/*
* Read an unsigned 32-bit integer in network byte order from 'b',
* convert it to host byte order, and return it.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used - b->current >= 4);
cp = isc_buffer_current(b);
b->current += 4;
result = ((unsigned int)(cp[0])) << 24;
result |= ((unsigned int)(cp[1])) << 16;
result |= ((unsigned int)(cp[2])) << 8;
result |= ((unsigned int)(cp[3]));
return (result);
}
void
isc__buffer_putuint32(isc_buffer_t *b, isc_uint32_t val) {
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + 4 <= b->length);
ISC__BUFFER_PUTUINT32(b, val);
}
isc_uint64_t
isc_buffer_getuint48(isc_buffer_t *b) {
unsigned char *cp;
isc_uint64_t result;
/*
* Read an unsigned 48-bit integer in network byte order from 'b',
* convert it to host byte order, and return it.
*/
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used - b->current >= 6);
cp = isc_buffer_current(b);
b->current += 6;
result = ((isc_int64_t)(cp[0])) << 40;
result |= ((isc_int64_t)(cp[1])) << 32;
result |= ((isc_int64_t)(cp[2])) << 24;
result |= ((isc_int64_t)(cp[3])) << 16;
result |= ((isc_int64_t)(cp[4])) << 8;
result |= ((isc_int64_t)(cp[5]));
return (result);
}
void
isc__buffer_putuint48(isc_buffer_t *b, isc_uint64_t val) {
isc_uint16_t valhi;
isc_uint32_t vallo;
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + 6 <= b->length);
valhi = (isc_uint16_t)(val >> 32);
vallo = (isc_uint32_t)(val & 0xFFFFFFFF);
ISC__BUFFER_PUTUINT16(b, valhi);
ISC__BUFFER_PUTUINT32(b, vallo);
}
void
isc__buffer_putmem(isc_buffer_t *b, const unsigned char *base,
unsigned int length)
{
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(b->used + length <= b->length);
ISC__BUFFER_PUTMEM(b, base, length);
}
void
isc__buffer_putstr(isc_buffer_t *b, const char *source) {
unsigned int l;
unsigned char *cp;
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(source != NULL);
/*
* Do not use ISC__BUFFER_PUTSTR(), so strlen is only done once.
*/
l = strlen(source);
REQUIRE(l <= isc_buffer_availablelength(b));
cp = isc_buffer_used(b);
memcpy(cp, source, l);
b->used += l;
}
isc_result_t
isc_buffer_copyregion(isc_buffer_t *b, const isc_region_t *r) {
unsigned char *base;
unsigned int available;
REQUIRE(ISC_BUFFER_VALID(b));
REQUIRE(r != NULL);
/*
* XXXDCL
*/
base = isc_buffer_used(b);
available = isc_buffer_availablelength(b);
if (r->length > available)
return (ISC_R_NOSPACE);
memcpy(base, r->base, r->length);
b->used += r->length;
return (ISC_R_SUCCESS);
}
isc_result_t
isc_buffer_allocate(isc_mem_t *mctx, isc_buffer_t **dynbuffer,
unsigned int length)
{
isc_buffer_t *dbuf;
REQUIRE(dynbuffer != NULL);
REQUIRE(*dynbuffer == NULL);
dbuf = isc_mem_get(mctx, length + sizeof(isc_buffer_t));
if (dbuf == NULL)
return (ISC_R_NOMEMORY);
isc_buffer_init(dbuf, ((unsigned char *)dbuf) + sizeof(isc_buffer_t),
length);
dbuf->mctx = mctx;
*dynbuffer = dbuf;
return (ISC_R_SUCCESS);
}
void
isc_buffer_free(isc_buffer_t **dynbuffer) {
unsigned int real_length;
isc_buffer_t *dbuf;
isc_mem_t *mctx;
REQUIRE(dynbuffer != NULL);
REQUIRE(ISC_BUFFER_VALID(*dynbuffer));
REQUIRE((*dynbuffer)->mctx != NULL);
dbuf = *dynbuffer;
*dynbuffer = NULL; /* destroy external reference */
real_length = dbuf->length + sizeof(isc_buffer_t);
mctx = dbuf->mctx;
dbuf->mctx = NULL;
isc_buffer_invalidate(dbuf);
isc_mem_put(mctx, dbuf, real_length);
}