sys/hash.h provides a simple (simplistic) hash function. There are probably better alternatives, like SipHash24. With the previous two diffs, there are no longer any references to sys/hash.h in the kernel.
Userland, however.... These should all be converted to SipHash24 to prevent bucket attacks. usr.sbin/bgpd/rde_attr.c:#include <sys/hash.h> usr.sbin/bgpd/rde_rib.c:#include <sys/hash.h> usr.sbin/bgpd/rde_update.c:#include <sys/hash.h> usr.sbin/httpd/httpd.c:#include <sys/hash.h> usr.sbin/httpd/parse.y:#include <sys/hash.h> usr.sbin/httpd/server.c:#include <sys/hash.h> usr.sbin/httpd/server_file.c:#include <sys/hash.h> usr.sbin/httpd/server_http.c:#include <sys/hash.h> usr.sbin/httpd/server_fcgi.c:#include <sys/hash.h> usr.sbin/ospf6d/lsupdate.c:#include <sys/hash.h> usr.sbin/ospfd/lsupdate.c:#include <sys/hash.h> usr.sbin/relayd/parse.y:#include <sys/hash.h> usr.sbin/relayd/relay.c:#include <sys/hash.h> usr.sbin/relayd/relay_http.c:#include <sys/hash.h> usr.sbin/relayd/relay_udp.c:#include <sys/hash.h> usr.sbin/relayd/relayd.c:#include <sys/hash.h>
