diff options
author | Daniel Veillard <veillard@redhat.com> | 2012-07-16 19:57:42 +0800 |
---|---|---|
committer | Daniel Veillard <veillard@redhat.com> | 2012-07-23 14:24:27 +0800 |
commit | 9ee02f80a4d674bac96f88b5a241825aad453a7a (patch) | |
tree | a41c7f5081efaae00192d7419f766e9954a5543f /buf.c | |
parent | 00ac0d3b96459865684fc9378e420e93418f9ef9 (diff) | |
download | libxml2-9ee02f80a4d674bac96f88b5a241825aad453a7a.tar.gz |
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.
Diffstat (limited to 'buf.c')
-rw-r--r-- | buf.c | 77 |
1 files changed, 47 insertions, 30 deletions
@@ -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; |