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apr_buffer: Redefine size to separate the unsigned size and the
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flag to indicate whether a zero terminated string or not.


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1917266 13f79535-47bb-0310-9956-ffa450edef68
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@minfrin
minfrin committed Apr 22, 2024
1 parent 497fef2 commit d409804
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Showing 3 changed files with 70 additions and 108 deletions.
123 changes: 49 additions & 74 deletions buffer/apr_buffer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -28,7 +28,7 @@
#include "apr_strings.h"
#include "apr_private.h"

#define APR_BUFFER_MAX APR_SIZE_MAX/2
#define APR_BUFFER_MAX (APR_SIZE_MAX/2-1)

APR_DECLARE(apr_status_t) apr_buffer_mem_set(apr_buffer_t *buf,
void *mem, apr_size_t len)
Expand All @@ -40,6 +40,7 @@ APR_DECLARE(apr_status_t) apr_buffer_mem_set(apr_buffer_t *buf,

buf->d.mem = mem;
buf->size = len;
buf->zero_terminated = 0;

return APR_SUCCESS;
}
Expand All @@ -58,6 +59,7 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_mem_make(apr_pool_t *pool,
if (buf) {
buf->d.mem = mem;
buf->size = len;
buf->zero_terminated = 0;
}

return buf;
Expand All @@ -74,21 +76,25 @@ APR_DECLARE(apr_status_t) apr_buffer_str_set(apr_buffer_t *buf,
if (!str) {
buf->d.str = NULL;
buf->size = 0;
buf->zero_terminated = 0;
}
else if (len < 0) {
apr_size_t slen = strlen(str);
if (slen <= APR_BUFFER_MAX) {
buf->d.str = str;
buf->size = -(apr_off_t)(slen + 1);
buf->size = slen;
buf->zero_terminated = 1;
}
else {
buf->d.str = NULL;
buf->size = 0;
buf->zero_terminated = 0;
}
}
else {
buf->d.str = str;
buf->size = -(len + 1);
buf->size = len;
buf->zero_terminated = 1;
}

return APR_SUCCESS;
Expand All @@ -100,32 +106,33 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_str_make(apr_pool_t *pool,
apr_buffer_t *buf;
apr_int64_t size;
apr_size_t slen;
unsigned int zero_terminated;

if (!str) {
str = NULL;
size = 0;
zero_terminated = 0;
}
if (APR_BUFFER_STRING == len && !str[0]) {
size = len;
}
else if (len < 0) {
if (APR_BUFFER_STRING == len) {
slen = strlen(str);
if (slen <= APR_BUFFER_MAX) {
size = -(apr_off_t)(slen + 1);
size = slen;
zero_terminated = 1;
}
else {
return NULL;
}
}
else {
size = -(len + 1);
size = (apr_size_t)len;
}

buf = apr_palloc(pool, sizeof(apr_buffer_t));

if (buf) {
buf->d.str = str;
buf->size = size;
buf->zero_terminated = zero_terminated;
}

return buf;
Expand All @@ -138,22 +145,12 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_null_make(apr_pool_t *pool)

APR_DECLARE(apr_size_t) apr_buffer_len(const apr_buffer_t *buf)
{
if (buf->size < 0) {
return (apr_size_t)((-buf->size) - 1);
}
else {
return (apr_size_t)buf->size;
}
return buf->size;
}

APR_DECLARE(apr_size_t) apr_buffer_allocated(const apr_buffer_t *buf)
{
if (buf->size < 0) {
return (apr_size_t)((-buf->size));
}
else {
return (apr_size_t)buf->size;
}
return buf->size + buf->zero_terminated;
}

APR_DECLARE(int) apr_buffer_is_null(const apr_buffer_t *buf)
Expand All @@ -168,17 +165,12 @@ APR_DECLARE(int) apr_buffer_is_null(const apr_buffer_t *buf)

APR_DECLARE(int) apr_buffer_is_str(const apr_buffer_t *buf)
{
if (buf->size < 0) {
return 1;
}
else {
return 0;
}
return buf->zero_terminated;
}

APR_DECLARE(char *) apr_buffer_str(const apr_buffer_t *buf)
{
if (buf->size < 0) {
if (buf->zero_terminated) {
return buf->d.str;
}
else {
Expand All @@ -188,12 +180,7 @@ APR_DECLARE(char *) apr_buffer_str(const apr_buffer_t *buf)

APR_DECLARE(char *) apr_buffer_pstrdup(apr_pool_t *pool, const apr_buffer_t *buf)
{
if (buf->size < 0) {
return apr_pstrmemdup(pool, buf->d.str, (apr_size_t)(-(buf->size + 1)));
}
else {
return apr_pstrmemdup(pool, buf->d.str, (apr_size_t)buf->size);
}
return apr_pstrmemdup(pool, buf->d.str, buf->size);
}

APR_DECLARE(void *) apr_buffer_mem(const apr_buffer_t *buf, apr_size_t *size)
Expand Down Expand Up @@ -227,11 +214,12 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_arraydup(const apr_buffer_t *src,
for (i = 0; i < nelts; i++) {

/* absolute value is size of mem buffer including optional terminating zero */
apr_size_t size = src->size < 0 ? -src->size : src->size;
apr_size_t size = src->size + src->zero_terminated;

void *mem = alloc(ctx, size);
memcpy(mem, src->d.mem, size);

dst->zero_terminated = src->zero_terminated;
dst->size = src->size;
dst->d.mem = mem;

Expand All @@ -256,22 +244,25 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_cpy(apr_buffer_t *dst,

dst->d.mem = NULL;
dst->size = 0;
dst->zero_terminated = 0;

}
else if (!alloc) {

dst->d.mem = src->d.mem;
dst->size = src->size;

dst->zero_terminated = src->zero_terminated;

}
else {

/* absolute value is size of mem buffer including optional terminating zero */
apr_size_t size = src->size < 0 ? -src->size : src->size;
apr_size_t size = src->size + src->zero_terminated;

void *mem = alloc(ctx, size);
memcpy(mem, src->d.mem, size);

dst->zero_terminated = src->zero_terminated;
dst->size = src->size;
dst->d.mem = mem;

Expand All @@ -280,33 +271,7 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_cpy(apr_buffer_t *dst,
return dst;
}


APR_DECLARE(int) apr_buffer_cmp(const apr_buffer_t *src,
const apr_buffer_t *dst)
{
apr_size_t slen = apr_buffer_len(src);
apr_size_t dlen = apr_buffer_len(dst);

if (slen != dlen) {
return slen < dlen ? -1 : 1;
}
else if (src->d.mem == dst->d.mem) {
/* identical data or both NULL */
return 0;
}
else if (!src->d.mem) {
return -1;
}
else if (!dst->d.mem) {
return 1;
}
else {
return memcmp(src->d.mem, dst->d.mem, slen);
}
}


APR_DECLARE(int) apr_buffer_ncmp(const apr_buffer_t *src,
const apr_buffer_t *dst)
{
if (!src || !src->d.mem) {
Expand All @@ -322,7 +287,17 @@ APR_DECLARE(int) apr_buffer_ncmp(const apr_buffer_t *src,
return 1;
}
else {
return apr_buffer_cmp(src, dst);

apr_size_t slen = apr_buffer_len(src);
apr_size_t dlen = apr_buffer_len(dst);

if (slen != dlen) {
return slen < dlen ? -1 : 1;
}
else {
return memcmp(src->d.mem, dst->d.mem, slen);
}

}
}
}
Expand All @@ -344,17 +319,17 @@ APR_DECLARE(char *) apr_buffer_pstrncat(apr_pool_t *p, const apr_buffer_t *buf,
size += seplen;
}

if (src->size < 0) {
size += (apr_size_t)(-src->size) - 1;
if (src->zero_terminated) {
size += src->size;
}
else {
if (APR_BUFFER_NONE == flags) {
size += (apr_size_t)src->size;
size += src->size;
}
else if (APR_BUFFER_BASE64 == flags) {
apr_size_t b64len;

if (APR_SUCCESS != apr_encode_base64(NULL, src->d.mem, (apr_size_t)src->size,
if (APR_SUCCESS != apr_encode_base64(NULL, src->d.mem, src->size,
APR_ENCODE_NONE, &b64len)) {
return NULL;
}
Expand All @@ -379,19 +354,19 @@ APR_DECLARE(char *) apr_buffer_pstrncat(apr_pool_t *p, const apr_buffer_t *buf,
strncpy(dst, sep, seplen);
dst += seplen;
}
if (src->size < 0) {
strncpy(dst, src->d.str, (apr_size_t)((-src->size) - 1));
dst += (-src->size) - 1;

if (src->zero_terminated) {
strncpy(dst, src->d.str, src->size);
dst += src->size;
}
else {
if (APR_BUFFER_NONE == flags) {
memcpy(dst, src->d.mem, (apr_size_t)src->size);
memcpy(dst, src->d.mem, src->size);
}
else if (APR_BUFFER_BASE64 == flags) {
apr_size_t b64len;

if (APR_SUCCESS != apr_encode_base64(dst, src->d.mem, (apr_size_t)src->size,
if (APR_SUCCESS != apr_encode_base64(dst, src->d.mem, src->size,
APR_ENCODE_NONE, &b64len)) {
return NULL;
}
Expand Down
43 changes: 15 additions & 28 deletions include/apr_buffer.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -73,13 +73,17 @@ typedef struct
void *mem;
} d;

/** size of the data. If positive, the data is of fixed size. If
* negative, the data is zero terminated and the absolute value
* represents the data length including terminating zero.
*
* we use apr_off_t to make it simple to detect overflow.
*/
apr_off_t size;
/** is the data zero terminated */
unsigned int zero_terminated:1;

/** size of the data, excluding terminating zero */
#if defined(SIZE_MAX) && SIZE_MAX == APR_UINT64_MAX
apr_size_t size:63;
#elif defined(SIZE_MAX) && SIZE_MAX == APR_UINT32_MAX
apr_size_t size:31;
#else
#error sizeof size_t is neither 64 nor 32 bit (SIZE_MAX not defined)
#endif

} apr_buffer_t;

Expand Down Expand Up @@ -343,23 +347,6 @@ APR_DECLARE(apr_buffer_t *) apr_buffer_cpy(apr_buffer_t *dst,
apr_buffer_alloc alloc, void *ctx)
__attribute__((nonnull(1)));

/**
* Compare two buffers for equality.
*
* Each buffer can be either a string or memory buffer.
*
* A string buffer and a memory buffer are considered equal if the length
* excluding any trailing zero is equal, and the contents without the trailing
* zero are the same.
* @param dst The first buffer
* @param src The second buffer
* @return Positive, negative, or zero, depending on whether b1 is greater
* than, less than, or equal to b2.
*/
APR_DECLARE(int) apr_buffer_cmp(const apr_buffer_t *dst,
const apr_buffer_t *src)
__attribute__((nonnull(1,2)));

/**
* Compare two possibly NULL buffers for equality.
*
Expand All @@ -372,11 +359,11 @@ APR_DECLARE(int) apr_buffer_cmp(const apr_buffer_t *dst,
* zero are the same.
* @param dst The first buffer
* @param src The second buffer
* @return Positive, negative, or zero, depending on whether b1 is greater
* than, less than, or equal to b2.
* @return Positive, negative, or zero, depending on whether src is greater
* than, less than, or equal to dst.
*/
APR_DECLARE(int) apr_buffer_ncmp(const apr_buffer_t *dst,
const apr_buffer_t *src);
APR_DECLARE(int) apr_buffer_cmp(const apr_buffer_t *dst,
const apr_buffer_t *src);

/**
* Concatenate multiple buffers and return a string.
Expand Down
12 changes: 6 additions & 6 deletions test/testbuffer.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -179,29 +179,29 @@ static void test_compare_buffers(abts_case *tc, void *data)
small = NULL;
large = NULL;
ABTS_ASSERT(tc, "NULL equals NULL",
!apr_buffer_ncmp(small, large));
!apr_buffer_cmp(small, large));

small = apr_buffer_null_make(pool);
ABTS_ASSERT(tc, "null buffer equals NULL",
!apr_buffer_ncmp(small, large));
!apr_buffer_cmp(small, large));

large = apr_buffer_null_make(pool);
ABTS_ASSERT(tc, "null buffer equals null buffer",
!apr_buffer_ncmp(small, large));
!apr_buffer_cmp(small, large));

small = NULL;
ABTS_ASSERT(tc, "NULL equals null buffer",
!apr_buffer_ncmp(small, large));
!apr_buffer_cmp(small, large));

small = apr_buffer_str_make(pool, same, APR_BUFFER_STRING);
large = apr_buffer_str_make(pool, same, APR_BUFFER_STRING);
ABTS_ASSERT(tc, "pointer equals same pointer",
!apr_buffer_ncmp(small, large));
!apr_buffer_cmp(small, large));

small = apr_buffer_str_make(pool, "same", APR_BUFFER_STRING);
large = apr_buffer_str_make(pool, "same", APR_BUFFER_STRING);
ABTS_ASSERT(tc, "'same' equals 'same'",
!apr_buffer_ncmp(small, large));
!apr_buffer_cmp(small, large));

small = apr_buffer_str_make(pool, "short", APR_BUFFER_STRING);
large = apr_buffer_str_make(pool, "l o n g", APR_BUFFER_STRING);
Expand Down

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