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Diffstat (limited to 'usr.sbin/bind/lib/lwres/lwbuffer.c')
| -rw-r--r-- | usr.sbin/bind/lib/lwres/lwbuffer.c | 360 |
1 files changed, 0 insertions, 360 deletions
diff --git a/usr.sbin/bind/lib/lwres/lwbuffer.c b/usr.sbin/bind/lib/lwres/lwbuffer.c deleted file mode 100644 index 8aee809e4a6..00000000000 --- a/usr.sbin/bind/lib/lwres/lwbuffer.c +++ /dev/null @@ -1,360 +0,0 @@ -/* - * Copyright (C) Internet Systems Consortium, Inc. ("ISC") - * - * 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: lwbuffer.c,v 1.3 2019/12/17 01:46:38 sthen Exp $ */ - -/*! \file */ - -/** - * These functions provide bounds checked access to a region of memory - * where data is being read or written. They are based on, and similar - * to, the isc_buffer_ functions in the ISC library. - * - * A buffer is a region of memory, together with a set of related - * subregions. The used region and the available region are disjoint, and - * their union is the buffer's region. The used region extends from the - * beginning of the buffer region to the last used byte. The available - * region extends from one byte greater than the last used byte to the - * end of the buffer's region. The size of the used region can be changed - * using various buffer commands. Initially, the used region is empty. - * - * The used region is further subdivided into two disjoint regions: the - * consumed region and the remaining region. The union of these two - * regions is the used region. The consumed region extends from the - * beginning of the used region to the byte before the current offset (if - * any). The remaining region the current pointer to the end of the used - * region. The size of the consumed region can be changed using various - * buffer commands. Initially, the consumed region is empty. - * - * The active region is an (optional) subregion of the remaining region. - * It extends from the current offset to an offset in the remaining - * region. Initially, the active region is empty. If the current offset - * advances beyond the chosen offset, the active region will also be - * empty. - * - * - * \verbatim - * /------------entire length---------------\\ - * /----- used region -----\\/-- available --\\ - * +----------------------------------------+ - * | consumed | remaining | | - * +----------------------------------------+ - * a b c d e - * - * a == base of buffer. - * b == current pointer. Can be anywhere between a and d. - * c == active pointer. Meaningful between b and d. - * d == used pointer. - * e == length of buffer. - * - * a-e == entire length of buffer. - * a-d == used region. - * a-b == consumed region. - * b-d == remaining region. - * b-c == optional active region. - * \endverbatim - * - * lwres_buffer_init() initializes the lwres_buffer_t *b and assocates it - * with the memory region of size length bytes starting at location base. - * - * lwres_buffer_invalidate() marks the buffer *b as invalid. Invalidating - * a buffer after use is not required, but makes it possible to catch its - * possible accidental use. - * - * The functions lwres_buffer_add() and lwres_buffer_subtract() - * respectively increase and decrease the used space in buffer *b by n - * bytes. lwres_buffer_add() checks for buffer overflow and - * lwres_buffer_subtract() checks for underflow. These functions do not - * allocate or deallocate memory. They just change the value of used. - * - * A buffer is re-initialised by lwres_buffer_clear(). The function sets - * used , current and active to zero. - * - * lwres_buffer_first() makes the consumed region of buffer *p empty by - * setting current to zero (the start of the buffer). - * - * lwres_buffer_forward() increases the consumed region of buffer *b by n - * bytes, checking for overflow. Similarly, lwres_buffer_back() decreases - * buffer b's consumed region by n bytes and checks for underflow. - * - * lwres_buffer_getuint8() reads an unsigned 8-bit integer from *b and - * returns it. lwres_buffer_putuint8() writes the unsigned 8-bit integer - * val to buffer *b. - * - * lwres_buffer_getuint16() and lwres_buffer_getuint32() are identical to - * lwres_buffer_putuint8() except that they respectively read an unsigned - * 16-bit or 32-bit integer in network byte order from b. Similarly, - * lwres_buffer_putuint16() and lwres_buffer_putuint32() writes the - * unsigned 16-bit or 32-bit integer val to buffer b, in network byte - * order. - * - * Arbitrary amounts of data are read or written from a lightweight - * resolver buffer with lwres_buffer_getmem() and lwres_buffer_putmem() - * respectively. lwres_buffer_putmem() copies length bytes of memory at - * base to b. Conversely, lwres_buffer_getmem() copies length bytes of - * memory from b to base. - */ - -#include <config.h> - -#include <string.h> - -#include <lwres/lwbuffer.h> - -#include "assert_p.h" - -void -lwres_buffer_init(lwres_buffer_t *b, void *base, unsigned int length) -{ - /* - * Make 'b' refer to the 'length'-byte region starting at base. - */ - - REQUIRE(b != NULL); - - b->magic = LWRES_BUFFER_MAGIC; - b->base = base; - b->length = length; - b->used = 0; - b->current = 0; - b->active = 0; -} - -/* Make 'b' an invalid buffer. */ -void -lwres_buffer_invalidate(lwres_buffer_t *b) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - - b->magic = 0; - b->base = NULL; - b->length = 0; - b->used = 0; - b->current = 0; - b->active = 0; -} - -/* Increase the 'used' region of 'b' by 'n' bytes. */ -void -lwres_buffer_add(lwres_buffer_t *b, unsigned int n) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used + n <= b->length); - - b->used += n; -} - -/* Decrease the 'used' region of 'b' by 'n' bytes. */ -void -lwres_buffer_subtract(lwres_buffer_t *b, unsigned int n) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used >= n); - - b->used -= n; - if (b->current > b->used) - b->current = b->used; - if (b->active > b->used) - b->active = b->used; -} - -/* Make the used region empty. */ -void -lwres_buffer_clear(lwres_buffer_t *b) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - - b->used = 0; - b->current = 0; - b->active = 0; -} - -/* Make the consumed region empty. */ -void -lwres_buffer_first(lwres_buffer_t *b) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - - b->current = 0; -} - -/* Increase the 'consumed' region of 'b' by 'n' bytes. */ -void -lwres_buffer_forward(lwres_buffer_t *b, unsigned int n) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->current + n <= b->used); - - b->current += n; -} - -/* Decrease the 'consumed' region of 'b' by 'n' bytes. */ -void -lwres_buffer_back(lwres_buffer_t *b, unsigned int n) -{ - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(n <= b->current); - - b->current -= n; -} - -/* Read an unsigned 8-bit integer from 'b' and return it. */ -lwres_uint8_t -lwres_buffer_getuint8(lwres_buffer_t *b) -{ - unsigned char *cp; - lwres_uint8_t result; - - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used - b->current >= 1); - - cp = b->base; - cp += b->current; - b->current += 1; - result = ((unsigned int)(cp[0])); - - return (result); -} - -/* Put an unsigned 8-bit integer */ -void -lwres_buffer_putuint8(lwres_buffer_t *b, lwres_uint8_t val) -{ - unsigned char *cp; - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used + 1 <= b->length); - - cp = b->base; - cp += b->used; - b->used += 1; - cp[0] = (val & 0x00ff); -} - -/* Read an unsigned 16-bit integer in network byte order from 'b', convert it to host byte order, and return it. */ -lwres_uint16_t -lwres_buffer_getuint16(lwres_buffer_t *b) -{ - unsigned char *cp; - lwres_uint16_t result; - - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used - b->current >= 2); - - cp = b->base; - cp += b->current; - b->current += 2; - result = ((unsigned int)(cp[0])) << 8; - result |= ((unsigned int)(cp[1])); - - return (result); -} - -/* Put an unsigned 16-bit integer. */ -void -lwres_buffer_putuint16(lwres_buffer_t *b, lwres_uint16_t val) -{ - unsigned char *cp; - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used + 2 <= b->length); - - cp = b->base; - cp += b->used; - b->used += 2; - cp[0] = (val & 0xff00) >> 8; - cp[1] = (val & 0x00ff); -} - -/* Read an unsigned 32-bit integer in network byte order from 'b', convert it to host byte order, and return it. */ -lwres_uint32_t -lwres_buffer_getuint32(lwres_buffer_t *b) -{ - unsigned char *cp; - lwres_uint32_t result; - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used - b->current >= 4); - - cp = b->base; - cp += b->current; - 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); -} - -/* Put an unsigned 32-bit integer. */ -void -lwres_buffer_putuint32(lwres_buffer_t *b, lwres_uint32_t val) -{ - unsigned char *cp; - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used + 4 <= b->length); - - cp = b->base; - cp += b->used; - b->used += 4; - cp[0] = (unsigned char)((val & 0xff000000) >> 24); - cp[1] = (unsigned char)((val & 0x00ff0000) >> 16); - cp[2] = (unsigned char)((val & 0x0000ff00) >> 8); - cp[3] = (unsigned char)(val & 0x000000ff); -} - -/* copies length bytes of memory at base to b */ -void -lwres_buffer_putmem(lwres_buffer_t *b, const unsigned char *base, - unsigned int length) -{ - unsigned char *cp; - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used + length <= b->length); - - cp = (unsigned char *)b->base + b->used; - memmove(cp, base, length); - b->used += length; -} - -/* copies length bytes of memory at b to base */ -void -lwres_buffer_getmem(lwres_buffer_t *b, unsigned char *base, - unsigned int length) -{ - unsigned char *cp; - - REQUIRE(LWRES_BUFFER_VALID(b)); - REQUIRE(b->used - b->current >= length); - - cp = b->base; - cp += b->current; - b->current += length; - - memmove(base, cp, length); -} |