[lib] Fix the struct message LOOKUP function to be more robust

2008-02-28 Paul Jakma <paul.jakma@sun.com>

	* log.c: (mes_lookup) Sowmini Varadhan diagnosed a problem where
	  this function can cause a NULL dereference, on lookups for unknown
	  indices, or messages with NULL strings. Can occur, e.g., debug
	  logging code when processing received messages. Fixed to accept a
	  pointer to a default string to be used if there is no match.
	* log.h: LOOKUP adjusted to match
This commit is contained in:
Paul Jakma 2008-02-28 23:26:02 +00:00
parent 5f56808431
commit 11486b5265
3 changed files with 34 additions and 10 deletions

View File

@ -1,3 +1,12 @@
2008-02-28 Paul Jakma <paul.jakma@sun.com>
* log.c: (mes_lookup) Sowmini Varadhan diagnosed a problem where
this function can cause a NULL dereference, on lookups for unknown
indices, or messages with NULL strings. Can occur, e.g., debug
logging code when processing received messages. Fixed to accept a
pointer to a default string to be used if there is no match.
* log.h: LOOKUP adjusted to match
2008-02-28 Paul Jakma <paul.jakma@sun.com>
* linklist.c: This implementation expects that the data pointer not

View File

@ -752,14 +752,24 @@ lookup (struct message *mes, int key)
}
/* Older/faster version of message lookup function, but requires caller to pass
in the array size (instead of relying on a 0 key to terminate the search). */
* in the array size (instead of relying on a 0 key to terminate the search).
*
* The return value is the message string if found, or the 'none' pointer
* provided otherwise.
*/
const char *
mes_lookup (struct message *meslist, int max, int index)
mes_lookup (struct message *meslist, int max, int index, const char *none)
{
int pos = index - meslist[0].key;
/* first check for best case: index is in range and matches the key
value in that slot */
if ((index >= 0) && (index < max) && (meslist[index].key == index))
return meslist[index].str;
* value in that slot.
* NB: key numbering might be offset from 0. E.g. protocol constants
* often start at 1.
*/
if ((pos >= 0) && (pos < max)
&& (meslist[pos].key == index))
return meslist[pos].str;
/* fall back to linear search */
{
@ -769,14 +779,17 @@ mes_lookup (struct message *meslist, int max, int index)
{
if (meslist->key == index)
{
const char *str = (meslist->str ? meslist->str : none);
zlog_debug ("message index %d [%s] found in position %d (max is %d)",
index, meslist->str, i, max);
return meslist->str;
index, str, i, max);
return str;
}
}
}
zlog_err("message index %d not found (max is %d)", index, max);
return NULL;
assert (none);
return none;
}
/* Wrapper around strerror to handle case where it returns NULL. */

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@ -142,10 +142,12 @@ extern int zlog_reset_file (struct zlog *zl);
extern int zlog_rotate (struct zlog *);
/* For hackey massage lookup and check */
#define LOOKUP(x, y) mes_lookup(x, x ## _max, y)
#define LOOKUP(x, y) mes_lookup(x, x ## _max, y, "(no item found)")
extern const char *lookup (struct message *, int);
extern const char *mes_lookup (struct message *meslist, int max, int index);
extern const char *mes_lookup (struct message *meslist,
int max, int index,
const char *no_item);
extern const char *zlog_priority[];
extern const char *zlog_proto_names[];