1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2021 Ng Peng Nam Sean 5 * Copyright (c) 2022 Alexander V. Chernikov <melifaro@FreeBSD.org> 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include "opt_netlink.h" 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 #include <sys/param.h> 34 #include <sys/kernel.h> 35 #include <sys/malloc.h> 36 #include <sys/module.h> 37 38 #include <sys/lock.h> 39 #include <sys/rmlock.h> 40 #include <sys/ck.h> 41 #include <sys/syslog.h> 42 43 #include <netlink/netlink.h> 44 #include <netlink/netlink_ctl.h> 45 #include <netlink/netlink_var.h> 46 #include <netlink/route/route_var.h> 47 48 #include <machine/atomic.h> 49 50 FEATURE(netlink, "Netlink support"); 51 52 #define DEBUG_MOD_NAME nl_mod 53 #define DEBUG_MAX_LEVEL LOG_DEBUG3 54 #include <netlink/netlink_debug.h> 55 _DECLARE_DEBUG(LOG_DEBUG); 56 57 58 #define NL_MAX_HANDLERS 20 59 struct nl_proto_handler _nl_handlers[NL_MAX_HANDLERS]; 60 struct nl_proto_handler *nl_handlers = _nl_handlers; 61 62 CK_LIST_HEAD(nl_control_head, nl_control); 63 static struct nl_control_head vnets_head = CK_LIST_HEAD_INITIALIZER(); 64 65 VNET_DEFINE(struct nl_control *, nl_ctl) = NULL; 66 67 struct mtx nl_global_mtx; 68 MTX_SYSINIT(nl_global_mtx, &nl_global_mtx, "global netlink lock", MTX_DEF); 69 70 #define NL_GLOBAL_LOCK() mtx_lock(&nl_global_mtx) 71 #define NL_GLOBAL_UNLOCK() mtx_unlock(&nl_global_mtx) 72 73 int netlink_unloading = 0; 74 75 static void 76 free_nl_ctl(struct nl_control *ctl) 77 { 78 rm_destroy(&ctl->ctl_lock); 79 free(ctl, M_NETLINK); 80 } 81 82 struct nl_control * 83 vnet_nl_ctl_init(void) 84 { 85 struct nl_control *ctl; 86 87 ctl = malloc(sizeof(struct nl_control), M_NETLINK, M_WAITOK | M_ZERO); 88 rm_init(&ctl->ctl_lock, "netlink lock"); 89 CK_LIST_INIT(&ctl->ctl_port_head); 90 CK_LIST_INIT(&ctl->ctl_pcb_head); 91 92 NL_GLOBAL_LOCK(); 93 94 struct nl_control *tmp = atomic_load_ptr(&V_nl_ctl); 95 96 if (tmp == NULL) { 97 atomic_store_ptr(&V_nl_ctl, ctl); 98 CK_LIST_INSERT_HEAD(&vnets_head, ctl, ctl_next); 99 NL_LOG(LOG_DEBUG2, "VNET %p init done, inserted %p into global list", 100 curvnet, ctl); 101 } else { 102 NL_LOG(LOG_DEBUG, "per-VNET init clash, dropping this instance"); 103 free_nl_ctl(ctl); 104 ctl = tmp; 105 } 106 107 NL_GLOBAL_UNLOCK(); 108 109 return (ctl); 110 } 111 112 static void 113 vnet_nl_ctl_destroy(const void *unused __unused) 114 { 115 struct nl_control *ctl; 116 117 /* Assume at the time all of the processes / sockets are dead */ 118 119 NL_GLOBAL_LOCK(); 120 ctl = atomic_load_ptr(&V_nl_ctl); 121 atomic_store_ptr(&V_nl_ctl, NULL); 122 if (ctl != NULL) { 123 NL_LOG(LOG_DEBUG2, "Removing %p from global list", ctl); 124 CK_LIST_REMOVE(ctl, ctl_next); 125 } 126 NL_GLOBAL_UNLOCK(); 127 128 if (ctl != NULL) 129 free_nl_ctl(ctl); 130 } 131 VNET_SYSUNINIT(vnet_nl_ctl_destroy, SI_SUB_PROTO_IF, SI_ORDER_ANY, 132 vnet_nl_ctl_destroy, NULL); 133 134 int 135 nl_verify_proto(int proto) 136 { 137 if (proto < 0 || proto >= NL_MAX_HANDLERS) { 138 return (EINVAL); 139 } 140 int handler_defined = nl_handlers[proto].cb != NULL; 141 return (handler_defined ? 0 : EPROTONOSUPPORT); 142 } 143 144 const char * 145 nl_get_proto_name(int proto) 146 { 147 return (nl_handlers[proto].proto_name); 148 } 149 150 bool 151 netlink_register_proto(int proto, const char *proto_name, nl_handler_f handler) 152 { 153 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 154 return (false); 155 NL_GLOBAL_LOCK(); 156 KASSERT((nl_handlers[proto].cb == NULL), ("netlink handler %d is already set", proto)); 157 nl_handlers[proto].cb = handler; 158 nl_handlers[proto].proto_name = proto_name; 159 NL_GLOBAL_UNLOCK(); 160 NL_LOG(LOG_DEBUG2, "Registered netlink %s(%d) handler", proto_name, proto); 161 return (true); 162 } 163 164 bool 165 netlink_unregister_proto(int proto) 166 { 167 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 168 return (false); 169 NL_GLOBAL_LOCK(); 170 KASSERT((nl_handlers[proto].cb != NULL), ("netlink handler %d is not set", proto)); 171 nl_handlers[proto].cb = NULL; 172 nl_handlers[proto].proto_name = NULL; 173 NL_GLOBAL_UNLOCK(); 174 NL_LOG(LOG_DEBUG2, "Unregistered netlink proto %d handler", proto); 175 return (true); 176 } 177 178 #if !defined(NETLINK) && defined(NETLINK_MODULE) 179 /* Non-stub function provider */ 180 const static struct nl_function_wrapper nl_module = { 181 .nlmsg_add = _nlmsg_add, 182 .nlmsg_refill_buffer = _nlmsg_refill_buffer, 183 .nlmsg_flush = _nlmsg_flush, 184 .nlmsg_end = _nlmsg_end, 185 .nlmsg_abort = _nlmsg_abort, 186 .nlmsg_get_unicast_writer = _nlmsg_get_unicast_writer, 187 .nlmsg_get_group_writer = _nlmsg_get_group_writer, 188 .nlmsg_get_chain_writer = _nlmsg_get_chain_writer, 189 .nlmsg_end_dump = _nlmsg_end_dump, 190 .nl_modify_ifp_generic = _nl_modify_ifp_generic, 191 .nl_store_ifp_cookie = _nl_store_ifp_cookie, 192 .nl_get_thread_nlp = _nl_get_thread_nlp, 193 }; 194 #endif 195 196 static bool 197 can_unload(void) 198 { 199 struct nl_control *ctl; 200 bool result = true; 201 202 NL_GLOBAL_LOCK(); 203 204 CK_LIST_FOREACH(ctl, &vnets_head, ctl_next) { 205 NL_LOG(LOG_DEBUG2, "Iterating VNET head %p", ctl); 206 if (!CK_LIST_EMPTY(&ctl->ctl_pcb_head)) { 207 NL_LOG(LOG_NOTICE, "non-empty socket list in ctl %p", ctl); 208 result = false; 209 break; 210 } 211 } 212 213 NL_GLOBAL_UNLOCK(); 214 215 return (result); 216 } 217 218 static int 219 netlink_modevent(module_t mod __unused, int what, void *priv __unused) 220 { 221 int ret = 0; 222 223 switch (what) { 224 case MOD_LOAD: 225 NL_LOG(LOG_DEBUG2, "Loading"); 226 nl_osd_register(); 227 #if !defined(NETLINK) && defined(NETLINK_MODULE) 228 nl_set_functions(&nl_module); 229 #endif 230 break; 231 232 case MOD_UNLOAD: 233 NL_LOG(LOG_DEBUG2, "Unload called"); 234 if (can_unload()) { 235 NL_LOG(LOG_WARNING, "unloading"); 236 netlink_unloading = 1; 237 #if !defined(NETLINK) && defined(NETLINK_MODULE) 238 nl_set_functions(NULL); 239 #endif 240 nl_osd_unregister(); 241 } else 242 ret = EBUSY; 243 break; 244 245 default: 246 ret = EOPNOTSUPP; 247 break; 248 } 249 250 return (ret); 251 } 252 static moduledata_t netlink_mod = { "netlink", netlink_modevent, NULL }; 253 254 DECLARE_MODULE(netlink, netlink_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 255 MODULE_VERSION(netlink, 1); 256