Data structure to help domain name compression in outgoing messages. More...
Data Fields | |
| struct compress_tree_node * | left |
| left node in tree, all smaller to this | |
| struct compress_tree_node * | right |
| right node in tree, all larger than this | |
| struct compress_tree_node * | parent |
| the parent node - not for tree, but zone parent. | |
| uint8_t * | dname |
| the domain name for this node. | |
| int | labs |
| number of labels in domain name, kept to help compare func. | |
| size_t | offset |
| offset in packet that points to this dname | |
Data structure to help domain name compression in outgoing messages.
A tree of dnames and their offsets in the packet is kept. It is kept sorted, not canonical, but by label at least, so that after a lookup of a name you know its closest match, and the parent from that closest match. These are possible compression targets.
It is a binary tree, not a rbtree or balanced tree, as the effort of keeping it balanced probably outweighs usefulness (given typical DNS packet size).
| struct compress_tree_node* compress_tree_node::parent |
the parent node - not for tree, but zone parent.
One less label
Referenced by compress_tree_lookup(), compress_tree_newnode(), and compress_tree_store().
| uint8_t* compress_tree_node::dname |
the domain name for this node.
Pointer to uncompressed memory.
Referenced by compress_any_dname(), compress_tree_lookup(), compress_tree_newnode(), compress_tree_search(), compress_tree_store(), and write_compressed_dname().