/*- * Copyright (c) 2010,2013 Lawrence Stewart * Copyright (c) 2010 The FreeBSD Foundation * All rights reserved. * * This software was developed by Lawrence Stewart while studying at the Centre * for Advanced Internet Architectures, Swinburne University of Technology, made * possible in part by grants from the FreeBSD Foundation and Cisco University * Research Program Fund at Community Foundation Silicon Valley. * * Portions of this software were developed at the Centre for Advanced * Internet Architectures, Swinburne University of Technology, Melbourne, * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD$ */ /* * A KPI modelled on the pfil framework for instantiating helper hook points * within the kernel for use by Khelp modules. Originally released as part of * the NewTCP research project at Swinburne University of Technology's Centre * for Advanced Internet Architectures, Melbourne, Australia, which was made * possible in part by a grant from the Cisco University Research Program Fund * at Community Foundation Silicon Valley. More details are available at: * http://caia.swin.edu.au/urp/newtcp/ */ #ifndef _SYS_HHOOK_H_ #define _SYS_HHOOK_H_ /* XXXLAS: Is there a way around this? */ #include #include /* hhook_head flags. */ #define HHH_ISINVNET 0x00000001 /* Is the hook point in a vnet? */ /* Flags common to all register functions. */ #define HHOOK_WAITOK 0x00000001 /* Sleeping allowed. */ #define HHOOK_NOWAIT 0x00000002 /* Sleeping disallowed. */ /* Flags only relevant to hhook_head_register() and hhook_head_is_virtual(). */ #define HHOOK_HEADISINVNET 0x00000100 /* Public proxy for HHH_ISINVNET. */ /* Helper hook types. */ #define HHOOK_TYPE_TCP 1 #define HHOOK_TYPE_SOCKET 2 struct helper; struct osd; /* Signature for helper hook functions. */ typedef int (*hhook_func_t)(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, void *hdata, struct osd *hosd); /* * Information required to add/remove a helper hook function to/from a helper * hook point. */ struct hookinfo { hhook_func_t hook_func; struct helper *hook_helper; void *hook_udata; int32_t hook_id; int32_t hook_type; }; /* * Ideally this would be private but we need access to the hhh_nhooks member * variable in order to make the HHOOKS_RUN_IF() macro low impact. */ struct hhook_head { STAILQ_HEAD(hhook_list, hhook) hhh_hooks; struct rmlock hhh_lock; uintptr_t hhh_vid; int32_t hhh_id; int32_t hhh_nhooks; int32_t hhh_type; uint32_t hhh_flags; volatile uint32_t hhh_refcount; LIST_ENTRY(hhook_head) hhh_next; LIST_ENTRY(hhook_head) hhh_vnext; }; /* Public KPI functions. */ void hhook_run_hooks(struct hhook_head *hhh, void *ctx_data, struct osd *hosd); int hhook_add_hook(struct hhook_head *hhh, struct hookinfo *hki, uint32_t flags); int hhook_add_hook_lookup(struct hookinfo *hki, uint32_t flags); int hhook_remove_hook(struct hhook_head *hhh, struct hookinfo *hki); int hhook_remove_hook_lookup(struct hookinfo *hki); int hhook_head_register(int32_t hhook_type, int32_t hhook_id, struct hhook_head **hhh, uint32_t flags); int hhook_head_deregister(struct hhook_head *hhh); int hhook_head_deregister_lookup(int32_t hhook_type, int32_t hhook_id); struct hhook_head * hhook_head_get(int32_t hhook_type, int32_t hhook_id); void hhook_head_release(struct hhook_head *hhh); uint32_t hhook_head_is_virtualised(struct hhook_head *hhh); uint32_t hhook_head_is_virtualised_lookup(int32_t hook_type, int32_t hook_id); /* * A wrapper around hhook_run_hooks() that only calls the function if at least * one helper hook function is registered for the specified helper hook point. */ #define HHOOKS_RUN_IF(hhh, ctx_data, hosd) do { \ if (hhh != NULL && hhh->hhh_nhooks > 0) \ hhook_run_hooks(hhh, ctx_data, hosd); \ } while (0) /* * WARNING: This macro should only be used in code paths that execute * infrequently, otherwise the refcounting overhead would be excessive. * * A similar wrapper to HHOOKS_RUN_IF() for situations where the caller prefers * not to lookup and store the appropriate hhook_head pointer themselves. */ #define HHOOKS_RUN_LOOKUP_IF(hhook_type, hhook_id, ctx_data, hosd) do { \ struct hhook_head *_hhh; \ \ _hhh = hhook_head_get(hhook_type, hhook_id); \ if (_hhh != NULL) { \ if (_hhh->hhh_nhooks > 0) \ hhook_run_hooks(_hhh, ctx_data, hosd); \ hhook_head_release(_hhh); \ } \ } while (0) #endif /* _SYS_HHOOK_H_ */