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-rw-r--r--source3/lib/util.c62
1 files changed, 56 insertions, 6 deletions
diff --git a/source3/lib/util.c b/source3/lib/util.c
index b74c08991a..b558571a77 100644
--- a/source3/lib/util.c
+++ b/source3/lib/util.c
@@ -3126,24 +3126,74 @@ int this_is_smp(void)
}
/****************************************************************
- Return a safe offset into a buffer, or NULL.
+ Check if an offset into a buffer is safe.
****************************************************************/
-char *get_safe_offset(const char *buf_base, size_t buf_len, char *ptr, size_t off)
+BOOL is_offset_safe(const char *buf_base, size_t buf_len, char *ptr, size_t off)
{
const char *end_base = buf_base + buf_len;
char *end_ptr = ptr + off;
if (!buf_base || !ptr) {
- return NULL;
+ return False;
}
if (end_base < buf_base || end_ptr < ptr) {
- return NULL; /* wrap. */
+ return False; /* wrap. */
}
if (end_ptr < end_base) {
- return end_ptr;
+ return True;
}
- return NULL;
+ return False;
+}
+
+/****************************************************************
+ Return a safe pointer into a buffer, or NULL.
+****************************************************************/
+
+char *get_safe_ptr(const char *buf_base, size_t buf_len, char *ptr, size_t off)
+{
+ return is_offset_safe(buf_base, buf_len, ptr, off) ?
+ ptr + off : NULL;
+}
+
+/****************************************************************
+ Return a safe pointer into a string within a buffer, or NULL.
+****************************************************************/
+
+char *get_safe_str_ptr(const char *buf_base, size_t buf_len, char *ptr, size_t off)
+{
+ if (!is_offset_safe(buf_base, buf_len, ptr, off)) {
+ return NULL;
+ }
+ /* Check if a valid string exists at this offset. */
+ if (skip_string(buf_base,buf_len, ptr + off, 1) == NULL) {
+ return NULL;
+ }
+ return ptr + off;
+}
+
+/****************************************************************
+ Return an SVAL at a pointer, or failval if beyond the end.
+****************************************************************/
+
+int get_safe_SVAL(const char *buf_base, size_t buf_len, char *ptr, size_t off, int failval)
+{
+ if (!is_offset_safe(buf_base, buf_len, ptr, off+2)) {
+ return failval;
+ }
+ return SVAL(ptr,0);
+}
+
+/****************************************************************
+ Return an IVAL at a pointer, or failval if beyond the end.
+****************************************************************/
+
+int get_safe_IVAL(const char *buf_base, size_t buf_len, char *ptr, size_t off, int failval)
+{
+ if (!is_offset_safe(buf_base, buf_len, ptr, off+4)) {
+ return failval;
+ }
+ return IVAL(ptr,0);
}