Commit 9ee02f80 authored by Daniel Veillard's avatar Daniel Veillard

Harden the buffer code and make it more compatible

Mimic the old xmlBuffer strcture in xmlBuf to avaoid catastrophic
failures in case of old code directly reading ctxt->input->buf->buffer

Check on all buffer entry points if an error previously occured on
the buffer, and fail the operation if this is the case, the buffer
becomes immutable and unreadable.
parent 00ac0d3b
......@@ -32,15 +32,19 @@
/**
* xmlBuf:
*
* A buffer structure
* A buffer structure. The base of the structure is somehow compatible
* with struct _xmlBuffer to limit risks on application which accessed
* directly the input->buf->buffer structures.
*/
struct _xmlBuf {
xmlChar *content; /* The buffer content UTF8 */
size_t use; /* The buffer size used */
size_t size; /* The buffer size */
unsigned int compat_use; /* for binary compatibility */
unsigned int compat_size; /* for binary compatibility */
xmlBufferAllocationScheme alloc; /* The realloc method */
xmlChar *contentIO; /* in IO mode we may have a different base */
size_t use; /* The buffer size used */
size_t size; /* The buffer size */
xmlBufferPtr buffer; /* wrapper for an old buffer */
int error; /* an error code if a failure occured */
};
......@@ -91,6 +95,8 @@ xmlBufCreate(void) {
xmlBufMemoryError(NULL, "creating buffer");
return(NULL);
}
ret->compat_use = 0;
ret->compat_size = 0;
ret->use = 0;
ret->error = 0;
ret->buffer = NULL;
......@@ -123,6 +129,8 @@ xmlBufCreateSize(size_t size) {
xmlBufMemoryError(NULL, "creating buffer");
return(NULL);
}
ret->compat_use = 0;
ret->compat_size = 0;
ret->use = 0;
ret->error = 0;
ret->buffer = NULL;
......@@ -197,6 +205,13 @@ xmlBufCreateStatic(void *mem, size_t size) {
xmlBufMemoryError(NULL, "creating buffer");
return(NULL);
}
if (size < INT_MAX) {
ret->compat_use = size;
ret->compat_size = size;
} else {
ret->compat_use = 0;
ret->compat_size = 0;
}
ret->use = size;
ret->size = size;
ret->alloc = XML_BUFFER_ALLOC_IMMUTABLE;
......@@ -234,10 +249,10 @@ xmlBufGetAllocationScheme(xmlBufPtr buf) {
int
xmlBufSetAllocationScheme(xmlBufPtr buf,
xmlBufferAllocationScheme scheme) {
if (buf == NULL) {
if ((buf == NULL) || (buf->error != 0)) {
#ifdef DEBUG_BUFFER
xmlGenericError(xmlGenericErrorContext,
"xmlBufSetAllocationScheme: buf == NULL\n");
"xmlBufSetAllocationScheme: buf == NULL or in error\n");
#endif
return(-1);
}
......@@ -299,7 +314,7 @@ xmlBufFree(xmlBufPtr buf) {
*/
void
xmlBufEmpty(xmlBufPtr buf) {
if (buf == NULL) return;
if ((buf == NULL) || (buf->error != 0)) return;
if (buf->content == NULL) return;
buf->use = 0;
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) {
......@@ -330,7 +345,7 @@ xmlBufEmpty(xmlBufPtr buf) {
*/
size_t
xmlBufShrink(xmlBufPtr buf, size_t len) {
if (buf == NULL) return(0);
if ((buf == NULL) || (buf->error != 0)) return(0);
if (len == 0) return(0);
if (len > buf->use) return(0);
......@@ -380,7 +395,7 @@ xmlBufGrowInternal(xmlBufPtr buf, size_t len) {
size_t size;
xmlChar *newbuf;
if (buf == NULL) return(0);
if ((buf == NULL) || (buf->error != 0)) return(0);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0);
if (buf->use + len < buf->size)
......@@ -476,10 +491,10 @@ size_t
xmlBufDump(FILE *file, xmlBufPtr buf) {
size_t ret;
if (buf == NULL) {
if ((buf == NULL) || (buf->error != 0)) {
#ifdef DEBUG_BUFFER
xmlGenericError(xmlGenericErrorContext,
"xmlBufDump: buf == NULL\n");
"xmlBufDump: buf == NULL or in error\n");
#endif
return(0);
}
......@@ -508,7 +523,7 @@ xmlBufDump(FILE *file, xmlBufPtr buf) {
xmlChar *
xmlBufContent(const xmlBufPtr buf)
{
if(!buf)
if ((!buf) || (buf->error))
return NULL;
return(buf->content);
......@@ -526,7 +541,7 @@ xmlBufContent(const xmlBufPtr buf)
xmlChar *
xmlBufEnd(const xmlBufPtr buf)
{
if(!buf)
if ((!buf) || (buf->error))
return NULL;
return(&buf->content[buf->use]);
......@@ -545,7 +560,7 @@ xmlBufEnd(const xmlBufPtr buf)
*/
int
xmlBufAddLen(xmlBufPtr buf, size_t len) {
if ((buf == NULL) || (len > (buf->size - buf->use)))
if ((buf == NULL) || (buf->error) || (len > (buf->size - buf->use)))
return(-1);
buf->use += len;
if (buf->size > buf->use)
......@@ -566,7 +581,7 @@ xmlBufAddLen(xmlBufPtr buf, size_t len) {
*/
int
xmlBufErase(xmlBufPtr buf, size_t len) {
if ((buf == NULL) || (len > buf->use))
if ((buf == NULL) || (buf->error) || (len > buf->use))
return(-1);
buf->use -= len;
buf->content[buf->use] = 0;
......@@ -585,7 +600,7 @@ xmlBufErase(xmlBufPtr buf, size_t len) {
size_t
xmlBufLength(const xmlBufPtr buf)
{
if (!buf)
if ((!buf) || (buf->error))
return 0;
return(buf->use);
......@@ -603,7 +618,7 @@ xmlBufLength(const xmlBufPtr buf)
size_t
xmlBufUse(const xmlBufPtr buf)
{
if (!buf)
if ((!buf) || (buf->error))
return 0;
return(buf->use);
......@@ -623,7 +638,7 @@ xmlBufUse(const xmlBufPtr buf)
size_t
xmlBufAvail(const xmlBufPtr buf)
{
if (!buf)
if ((!buf) || (buf->error))
return 0;
return(buf->size - buf->use);
......@@ -640,7 +655,7 @@ xmlBufAvail(const xmlBufPtr buf)
int
xmlBufIsEmpty(const xmlBufPtr buf)
{
if(!buf)
if ((!buf) || (buf->error))
return(-1);
return(buf->use == 0);
......@@ -662,7 +677,7 @@ xmlBufResize(xmlBufPtr buf, size_t size)
xmlChar* rebuf = NULL;
size_t start_buf;
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(0);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return(0);
......@@ -771,7 +786,7 @@ int
xmlBufAdd(xmlBufPtr buf, const xmlChar *str, int len) {
unsigned int needSize;
if ((str == NULL) || (buf == NULL)) {
if ((str == NULL) || (buf == NULL) || (buf->error)) {
return -1;
}
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1;
......@@ -820,7 +835,7 @@ int
xmlBufAddHead(xmlBufPtr buf, const xmlChar *str, int len) {
unsigned int needSize;
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1;
if (str == NULL) {
......@@ -885,7 +900,7 @@ xmlBufAddHead(xmlBufPtr buf, const xmlChar *str, int len) {
*/
int
xmlBufCat(xmlBufPtr buf, const xmlChar *str) {
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1;
if (str == NULL) return -1;
......@@ -906,7 +921,7 @@ int
xmlBufCCat(xmlBufPtr buf, const char *str) {
const char *cur;
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE) return -1;
if (str == NULL) {
......@@ -942,7 +957,7 @@ xmlBufCCat(xmlBufPtr buf, const char *str) {
*/
int
xmlBufWriteCHAR(xmlBufPtr buf, const xmlChar *string) {
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE)
return(-1);
......@@ -962,7 +977,7 @@ xmlBufWriteCHAR(xmlBufPtr buf, const xmlChar *string) {
*/
int
xmlBufWriteChar(xmlBufPtr buf, const char *string) {
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE)
return(-1);
......@@ -985,7 +1000,7 @@ xmlBufWriteChar(xmlBufPtr buf, const char *string) {
int
xmlBufWriteQuotedString(xmlBufPtr buf, const xmlChar *string) {
const xmlChar *cur, *base;
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(-1);
if (buf->alloc == XML_BUFFER_ALLOC_IMMUTABLE)
return(-1);
......@@ -1076,7 +1091,7 @@ xmlBufferPtr
xmlBufBackToBuffer(xmlBufPtr buf) {
xmlBufferPtr ret;
if (buf == NULL)
if ((buf == NULL) || (buf->error))
return(NULL);
if (buf->buffer == NULL) {
xmlBufFree(buf);
......@@ -1128,7 +1143,7 @@ int
xmlBufMergeBuffer(xmlBufPtr buf, xmlBufferPtr buffer) {
int ret;
if (buffer == NULL)
if ((buf == NULL) || (buf->error))
return(0);
if ((buf != NULL) && (buffer->content != NULL) && (buffer->use > 0)) {
ret = xmlBufAdd(buf, buffer->content, buffer->use);
......@@ -1148,7 +1163,7 @@ xmlBufMergeBuffer(xmlBufPtr buf, xmlBufferPtr buffer) {
*/
int
xmlBufResetInput(xmlBufPtr buf, xmlParserInputPtr input) {
if ((input == NULL) || (buf == NULL))
if ((input == NULL) || (buf == NULL) || (buf->error))
return(-1);
input->base = input->cur = buf->content;
input->end = &buf->content[buf->use];
......@@ -1168,6 +1183,8 @@ size_t
xmlBufGetInputBase(xmlBufPtr buf, xmlParserInputPtr input) {
size_t base;
if ((input == NULL) || (buf == NULL) || (buf->error))
return(-1);
base = input->base - buf->content;
/*
* We could do some pointer arythmetic checks but that's probably
......@@ -1193,7 +1210,7 @@ xmlBufGetInputBase(xmlBufPtr buf, xmlParserInputPtr input) {
int
xmlBufSetInputBaseCur(xmlBufPtr buf, xmlParserInputPtr input,
size_t base, size_t cur) {
if ((input == NULL) || (buf == NULL))
if ((input == NULL) || (buf == NULL) || (buf->error))
return(-1);
input->base = &buf->content[base];
input->cur = input->base + cur;
......
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