diff options
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.developer | 30 |
1 files changed, 16 insertions, 14 deletions
diff --git a/doc/README.developer b/doc/README.developer index 57aaed46f6..29cc51443d 100644 --- a/doc/README.developer +++ b/doc/README.developer @@ -898,20 +898,22 @@ dissect_PROTOABBREV(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree) data needed only if you're building the protocol tree, if possible. Note, however, that you must fill in column information, create - conversations, reassemble packets, build any other persistent state - needed for dissection, and call subdissectors regardless of whether - "tree" is NULL or not. This might be inconvenient to do without - doing most of the dissection work; the routines for adding items to - the protocol tree can be passed a null protocol tree pointer, in - which case they'll return a null item pointer, and - "proto_item_add_subtree()" returns a null tree pointer if passed a - null item pointer, so, if you're careful not to dereference any null - tree or item pointers, you can accomplish this by doing all the - dissection work. This might not be as efficient as skipping that - work if you're not building a protocol tree, but if the code would - have a lot of tests whether "tree" is null if you skipped that work, - you might still be better off just doing all that work regardless of - whether "tree" is null or not. + conversations, reassemble packets, do calls to "expert" functions, + build any other persistent state needed for dissection, and call + subdissectors regardless of whether "tree" is NULL or not. + + This might be inconvenient to do without doing most of the + dissection work; the routines for adding items to the protocol tree + can be passed a null protocol tree pointer, in which case they'll + return a null item pointer, and "proto_item_add_subtree()" returns + a null tree pointer if passed a null item pointer, so, if you're + careful not to dereference any null tree or item pointers, you can + accomplish this by doing all the dissection work. This might not + be as efficient as skipping that work if you're not building a + protocol tree, but if the code would have a lot of tests whether + "tree" is null if you skipped that work, you might still be better + off just doing all that work regardless of whether "tree" is null + or not. Note also that there is no guarantee, the first time the dissector is called, whether "tree" will be null or not; your dissector must work |