1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2010,2013 Lawrence Stewart <lstewart@freebsd.org> 5 * Copyright (c) 2010 The FreeBSD Foundation 6 * All rights reserved. 7 * 8 * This software was developed by Lawrence Stewart while studying at the Centre 9 * for Advanced Internet Architectures, Swinburne University of Technology, made 10 * possible in part by grants from the FreeBSD Foundation and Cisco University 11 * Research Program Fund at Community Foundation Silicon Valley. 12 * 13 * Portions of this software were developed at the Centre for Advanced 14 * Internet Architectures, Swinburne University of Technology, Melbourne, 15 * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation. 16 * 17 * Redistribution and use in source and binary forms, with or without 18 * modification, are permitted provided that the following conditions 19 * are met: 20 * 1. Redistributions of source code must retain the above copyright 21 * notice, this list of conditions and the following disclaimer. 22 * 2. Redistributions in binary form must reproduce the above copyright 23 * notice, this list of conditions and the following disclaimer in the 24 * documentation and/or other materials provided with the distribution. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39 /* 40 * A KPI modelled on the pfil framework for instantiating helper hook points 41 * within the kernel for use by Khelp modules. Originally released as part of 42 * the NewTCP research project at Swinburne University of Technology's Centre 43 * for Advanced Internet Architectures, Melbourne, Australia, which was made 44 * possible in part by a grant from the Cisco University Research Program Fund 45 * at Community Foundation Silicon Valley. More details are available at: 46 * http://caia.swin.edu.au/urp/newtcp/ 47 */ 48 49 #ifndef _SYS_HHOOK_H_ 50 #define _SYS_HHOOK_H_ 51 52 /* XXXLAS: Is there a way around this? */ 53 #include <sys/lock.h> 54 #include <sys/rmlock.h> 55 56 /* hhook_head flags. */ 57 #define HHH_ISINVNET 0x00000001 /* Is the hook point in a vnet? */ 58 59 /* Flags common to all register functions. */ 60 #define HHOOK_WAITOK 0x00000001 /* Sleeping allowed. */ 61 #define HHOOK_NOWAIT 0x00000002 /* Sleeping disallowed. */ 62 /* Flags only relevant to hhook_head_register() and hhook_head_is_virtual(). */ 63 #define HHOOK_HEADISINVNET 0x00000100 /* Public proxy for HHH_ISINVNET. */ 64 65 /* Helper hook types. */ 66 #define HHOOK_TYPE_TCP 1 67 #define HHOOK_TYPE_SOCKET 2 68 #define HHOOK_TYPE_IPSEC_IN 3 69 #define HHOOK_TYPE_IPSEC_OUT 4 70 71 struct helper; 72 struct osd; 73 74 /* Signature for helper hook functions. */ 75 typedef int (*hhook_func_t)(int32_t hhook_type, int32_t hhook_id, void *udata, 76 void *ctx_data, void *hdata, struct osd *hosd); 77 78 /* 79 * Information required to add/remove a helper hook function to/from a helper 80 * hook point. 81 */ 82 struct hookinfo { 83 hhook_func_t hook_func; 84 struct helper *hook_helper; 85 void *hook_udata; 86 int32_t hook_id; 87 int32_t hook_type; 88 }; 89 90 /* 91 * Ideally this would be private but we need access to the hhh_nhooks member 92 * variable in order to make the HHOOKS_RUN_IF() macro low impact. 93 */ 94 struct hhook_head { 95 STAILQ_HEAD(hhook_list, hhook) hhh_hooks; 96 struct rmlock hhh_lock; 97 uintptr_t hhh_vid; 98 int32_t hhh_id; 99 int32_t hhh_nhooks; 100 int32_t hhh_type; 101 uint32_t hhh_flags; 102 volatile uint32_t hhh_refcount; 103 LIST_ENTRY(hhook_head) hhh_next; 104 LIST_ENTRY(hhook_head) hhh_vnext; 105 }; 106 107 /* Public KPI functions. */ 108 void hhook_run_hooks(struct hhook_head *hhh, void *ctx_data, struct osd *hosd); 109 110 int hhook_add_hook(struct hhook_head *hhh, struct hookinfo *hki, 111 uint32_t flags); 112 113 int hhook_add_hook_lookup(struct hookinfo *hki, uint32_t flags); 114 115 int hhook_remove_hook(struct hhook_head *hhh, struct hookinfo *hki); 116 117 int hhook_remove_hook_lookup(struct hookinfo *hki); 118 119 int hhook_head_register(int32_t hhook_type, int32_t hhook_id, 120 struct hhook_head **hhh, uint32_t flags); 121 122 int hhook_head_deregister(struct hhook_head *hhh); 123 124 int hhook_head_deregister_lookup(int32_t hhook_type, int32_t hhook_id); 125 126 struct hhook_head * hhook_head_get(int32_t hhook_type, int32_t hhook_id); 127 128 void hhook_head_release(struct hhook_head *hhh); 129 130 uint32_t hhook_head_is_virtualised(struct hhook_head *hhh); 131 132 uint32_t hhook_head_is_virtualised_lookup(int32_t hook_type, int32_t hook_id); 133 134 /* 135 * A wrapper around hhook_run_hooks() that only calls the function if at least 136 * one helper hook function is registered for the specified helper hook point. 137 */ 138 #define HHOOKS_RUN_IF(hhh, ctx_data, hosd) do { \ 139 if (hhh != NULL && hhh->hhh_nhooks > 0) \ 140 hhook_run_hooks(hhh, ctx_data, hosd); \ 141 } while (0) 142 143 /* 144 * WARNING: This macro should only be used in code paths that execute 145 * infrequently, otherwise the refcounting overhead would be excessive. 146 * 147 * A similar wrapper to HHOOKS_RUN_IF() for situations where the caller prefers 148 * not to lookup and store the appropriate hhook_head pointer themselves. 149 */ 150 #define HHOOKS_RUN_LOOKUP_IF(hhook_type, hhook_id, ctx_data, hosd) do { \ 151 struct hhook_head *_hhh; \ 152 \ 153 _hhh = hhook_head_get(hhook_type, hhook_id); \ 154 if (_hhh != NULL) { \ 155 if (_hhh->hhh_nhooks > 0) \ 156 hhook_run_hooks(_hhh, ctx_data, hosd); \ 157 hhook_head_release(_hhh); \ 158 } \ 159 } while (0) 160 161 #endif /* _SYS_HHOOK_H_ */ 162