1 /* 2 * Copyright (c) 2007-2008 3 * Swinburne University of Technology, Melbourne, Australia. 4 * Copyright (c) 2009-2010 Lawrence Stewart <lstewart@freebsd.org> 5 * Copyright (c) 2010 The FreeBSD Foundation 6 * All rights reserved. 7 * Copyright (c) 2017 by Delphix. All rights reserved. 8 * 9 * This software was developed at the Centre for Advanced Internet 10 * Architectures, Swinburne University of Technology, by Lawrence Stewart and 11 * James Healy, made possible in part by a grant from the Cisco University 12 * Research Program Fund at Community Foundation Silicon Valley. 13 * 14 * Portions of this software were developed at the Centre for Advanced 15 * Internet Architectures, Swinburne University of Technology, Melbourne, 16 * Australia by David Hayes under sponsorship from the FreeBSD Foundation. 17 * 18 * Redistribution and use in source and binary forms, with or without 19 * modification, are permitted provided that the following conditions 20 * are met: 21 * 1. Redistributions of source code must retain the above copyright 22 * notice, this list of conditions and the following disclaimer. 23 * 2. Redistributions in binary form must reproduce the above copyright 24 * notice, this list of conditions and the following disclaimer in the 25 * documentation and/or other materials provided with the distribution. 26 * 27 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 28 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 30 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 37 * SUCH DAMAGE. 38 */ 39 40 /* 41 * This software was first released in 2007 by James Healy and Lawrence Stewart 42 * whilst working on the NewTCP research project at Swinburne University of 43 * Technology's Centre for Advanced Internet Architectures, Melbourne, 44 * Australia, which was made possible in part by a grant from the Cisco 45 * University Research Program Fund at Community Foundation Silicon Valley. 46 * More details are available at: 47 * http://caia.swin.edu.au/urp/newtcp/ 48 */ 49 50 #include <sys/param.h> 51 #include <sys/errno.h> 52 #include <sys/systm.h> 53 #include <sys/queue.h> 54 #include <inet/cc.h> 55 #include <inet/tcp.h> 56 #include <sys/sdt.h> 57 58 #define CC_KMODDIR "cc" 59 60 /* 61 * List of available cc algorithms on the current system. Access is 62 * synchronized using cc_list_lock. 63 */ 64 static STAILQ_HEAD(cc_head, cc_algo) cc_list = STAILQ_HEAD_INITIALIZER(cc_list); 65 static kmutex_t cc_list_lock; 66 67 static struct modlmisc cc_modlmisc = { 68 &mod_miscops, 69 "Pluggable Congestion Control Framework" 70 }; 71 72 static struct modlinkage cc_modlinkage = { 73 MODREV_1, 74 &cc_modlmisc, 75 NULL 76 }; 77 78 /* 79 * Initialise CC subsystem on system boot. 80 */ 81 int 82 _init(void) 83 { 84 STAILQ_INIT(&cc_list); 85 86 return (mod_install(&cc_modlinkage)); 87 } 88 89 int 90 _fini(void) 91 { 92 return (EBUSY); 93 } 94 95 int 96 _info(struct modinfo *modinfop) 97 { 98 return (mod_info(&cc_modlinkage, modinfop)); 99 } 100 101 int 102 cc_walk_algos(cc_walk_func_t *func, void *cd) 103 { 104 struct cc_algo *algo; 105 int ret = 0; 106 107 mutex_enter(&cc_list_lock); 108 STAILQ_FOREACH(algo, &cc_list, entries) { 109 if ((ret = func(cd, algo)) != 0) { 110 break; 111 } 112 } 113 mutex_exit(&cc_list_lock); 114 115 return (ret); 116 } 117 118 /* 119 * Search for an algorithm of a given name, and return the corresponding set of 120 * operations. If there is no algorithm with the given name present, then this 121 * function returns NULL. 122 * 123 * Since this function is passed names from userland, it needs to be paranoid 124 * about the string, in case it's missing a terminating NUL character. 125 */ 126 struct cc_algo * 127 cc_load_algo(const char *name) 128 { 129 struct cc_algo *algo; 130 boolean_t found = B_FALSE; 131 132 if (strnlen(name, CC_ALGO_NAME_MAX) >= CC_ALGO_NAME_MAX) { 133 return (NULL); 134 } 135 136 mutex_enter(&cc_list_lock); 137 STAILQ_FOREACH(algo, &cc_list, entries) { 138 if (strncmp(algo->name, name, CC_ALGO_NAME_MAX) == 0) { 139 found = B_TRUE; 140 break; 141 } 142 } 143 mutex_exit(&cc_list_lock); 144 145 return (found ? algo : NULL); 146 } 147 148 /* 149 * Returns non-zero on success, 0 on failure. 150 */ 151 int 152 cc_deregister_algo(struct cc_algo *remove_cc) 153 { 154 struct cc_algo *funcs, *tmpfuncs; 155 int err = ENOENT; 156 157 mutex_enter(&cc_list_lock); 158 STAILQ_FOREACH_SAFE(funcs, &cc_list, entries, tmpfuncs) { 159 if (funcs == remove_cc) { 160 STAILQ_REMOVE(&cc_list, funcs, cc_algo, entries); 161 err = 0; 162 break; 163 } 164 } 165 mutex_exit(&cc_list_lock); 166 return (err); 167 } 168 169 /* 170 * Returns 0 on success, non-zero on failure. 171 */ 172 int 173 cc_register_algo(struct cc_algo *add_cc) 174 { 175 struct cc_algo *funcs; 176 size_t nlen; 177 int err = 0; 178 179 nlen = strnlen(add_cc->name, CC_ALGO_NAME_MAX); 180 if (nlen == 0 || nlen >= CC_ALGO_NAME_MAX) { 181 return (EINVAL); 182 } 183 184 /* 185 * Iterate over list of registered CC algorithms and make sure 186 * we're not trying to add a duplicate. 187 */ 188 mutex_enter(&cc_list_lock); 189 STAILQ_FOREACH(funcs, &cc_list, entries) { 190 if (strncmp(funcs->name, add_cc->name, CC_ALGO_NAME_MAX) == 0) 191 err = EEXIST; 192 } 193 194 if (err == 0) 195 STAILQ_INSERT_TAIL(&cc_list, add_cc, entries); 196 197 mutex_exit(&cc_list_lock); 198 199 return (err); 200 } 201