usr.lib/in.dhcpd/README.caching

5 # Common Development and Distribution License, Version 1.0 only
12 # and limitations under the License.
15 # file and include the License file at usr/src/OPENSOLARIS.LICENSE.
46 The cache implementation consists of a number of hash tables and lists,
47 enumerated below, along with a timeout and refresh mechanism:
54 	  handle to the underlying datastore, and a variety of caches which
73 	  and in-use IP addresses on the given network.
96 The concurrency between the datastore and cached records is handled by the
97 underlying datastore implementation using perimeters and is transparent to
99 functions used by in.dhcpd and DHCP server admin tools to lookup and modify
108 or a new dsvc_dnet_t is allocated and inserted to ntable.  Then, using the
110 dsvc_dnet_t's ctable hash and returns the client structure (dsvc_clnt_t) if
111 found.  Otherwise, a new dsvc_clnt_t is allocated and inserted into the
120 	1. If there is a pre-assigned IP for this client and the cached offer
121 	   is not timed out, then use the IP and the record in the
122 	   dsvc_clnt_t and make an OFFER.
125 	   remove the cached OFFER from the itable, and try to find a new
133 	If none is found, then the free record list (freerec) and least
136 	is expired, in.dhcpd removes any existing records and attempts to
140 	If a usable record is found, the server generates and sends an OFFER
149 	   record is updated, and the ACK is sent.  If it is expired and the
151 	   silently ignored (and the client should eventually drop back
157 	   and an ACK is sent.
160 datastore so that it is marked free, and, if successful, puts the record onto