1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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 <sys/param.h> 30 #include <sys/kernel.h> 31 #include <sys/malloc.h> 32 #include <sys/module.h> 33 34 #include <sys/lock.h> 35 #include <sys/rmlock.h> 36 #include <sys/ck.h> 37 #include <sys/syslog.h> 38 39 #include <netlink/netlink.h> 40 #include <netlink/netlink_ctl.h> 41 #include <netlink/netlink_var.h> 42 #include <netlink/route/route_var.h> 43 44 #include <machine/atomic.h> 45 46 FEATURE(netlink, "Netlink support"); 47 48 #define DEBUG_MOD_NAME nl_mod 49 #define DEBUG_MAX_LEVEL LOG_DEBUG3 50 #include <netlink/netlink_debug.h> 51 _DECLARE_DEBUG(LOG_INFO); 52 53 54 #define NL_MAX_HANDLERS 20 55 struct nl_proto_handler _nl_handlers[NL_MAX_HANDLERS]; 56 struct nl_proto_handler *nl_handlers = _nl_handlers; 57 58 CK_LIST_HEAD(nl_control_head, nl_control); 59 static struct nl_control_head vnets_head = CK_LIST_HEAD_INITIALIZER(); 60 61 VNET_DEFINE(struct nl_control *, nl_ctl) = NULL; 62 63 struct mtx nl_global_mtx; 64 MTX_SYSINIT(nl_global_mtx, &nl_global_mtx, "global netlink lock", MTX_DEF); 65 66 #define NL_GLOBAL_LOCK() mtx_lock(&nl_global_mtx) 67 #define NL_GLOBAL_UNLOCK() mtx_unlock(&nl_global_mtx) 68 69 int netlink_unloading = 0; 70 71 static void 72 free_nl_ctl(struct nl_control *ctl) 73 { 74 rm_destroy(&ctl->ctl_lock); 75 free(ctl, M_NETLINK); 76 } 77 78 struct nl_control * 79 vnet_nl_ctl_init(void) 80 { 81 struct nl_control *ctl; 82 83 ctl = malloc(sizeof(struct nl_control), M_NETLINK, M_WAITOK | M_ZERO); 84 rm_init(&ctl->ctl_lock, "netlink lock"); 85 CK_LIST_INIT(&ctl->ctl_port_head); 86 CK_LIST_INIT(&ctl->ctl_pcb_head); 87 88 NL_GLOBAL_LOCK(); 89 90 struct nl_control *tmp = atomic_load_ptr(&V_nl_ctl); 91 92 if (tmp == NULL) { 93 atomic_store_ptr(&V_nl_ctl, ctl); 94 CK_LIST_INSERT_HEAD(&vnets_head, ctl, ctl_next); 95 NL_LOG(LOG_DEBUG2, "VNET %p init done, inserted %p into global list", 96 curvnet, ctl); 97 } else { 98 NL_LOG(LOG_DEBUG, "per-VNET init clash, dropping this instance"); 99 free_nl_ctl(ctl); 100 ctl = tmp; 101 } 102 103 NL_GLOBAL_UNLOCK(); 104 105 return (ctl); 106 } 107 108 static void 109 vnet_nl_ctl_destroy(const void *unused __unused) 110 { 111 struct nl_control *ctl; 112 113 /* Assume at the time all of the processes / sockets are dead */ 114 115 NL_GLOBAL_LOCK(); 116 ctl = atomic_load_ptr(&V_nl_ctl); 117 atomic_store_ptr(&V_nl_ctl, NULL); 118 if (ctl != NULL) { 119 NL_LOG(LOG_DEBUG2, "Removing %p from global list", ctl); 120 CK_LIST_REMOVE(ctl, ctl_next); 121 } 122 NL_GLOBAL_UNLOCK(); 123 124 if (ctl != NULL) 125 free_nl_ctl(ctl); 126 } 127 VNET_SYSUNINIT(vnet_nl_ctl_destroy, SI_SUB_PROTO_IF, SI_ORDER_ANY, 128 vnet_nl_ctl_destroy, NULL); 129 130 int 131 nl_verify_proto(int proto) 132 { 133 if (proto < 0 || proto >= NL_MAX_HANDLERS) { 134 return (EINVAL); 135 } 136 int handler_defined = nl_handlers[proto].cb != NULL; 137 return (handler_defined ? 0 : EPROTONOSUPPORT); 138 } 139 140 const char * 141 nl_get_proto_name(int proto) 142 { 143 return (nl_handlers[proto].proto_name); 144 } 145 146 bool 147 netlink_register_proto(int proto, const char *proto_name, nl_handler_f handler) 148 { 149 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 150 return (false); 151 NL_GLOBAL_LOCK(); 152 KASSERT((nl_handlers[proto].cb == NULL), ("netlink handler %d is already set", proto)); 153 nl_handlers[proto].cb = handler; 154 nl_handlers[proto].proto_name = proto_name; 155 NL_GLOBAL_UNLOCK(); 156 NL_LOG(LOG_DEBUG2, "Registered netlink %s(%d) handler", proto_name, proto); 157 return (true); 158 } 159 160 bool 161 netlink_unregister_proto(int proto) 162 { 163 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 164 return (false); 165 NL_GLOBAL_LOCK(); 166 KASSERT((nl_handlers[proto].cb != NULL), ("netlink handler %d is not set", proto)); 167 nl_handlers[proto].cb = NULL; 168 nl_handlers[proto].proto_name = NULL; 169 NL_GLOBAL_UNLOCK(); 170 NL_LOG(LOG_DEBUG2, "Unregistered netlink proto %d handler", proto); 171 return (true); 172 } 173 174 #if !defined(NETLINK) && defined(NETLINK_MODULE) 175 /* Non-stub function provider */ 176 const static struct nl_function_wrapper nl_module = { 177 .nlmsg_add = _nlmsg_add, 178 .nlmsg_refill_buffer = _nlmsg_refill_buffer, 179 .nlmsg_flush = _nlmsg_flush, 180 .nlmsg_end = _nlmsg_end, 181 .nlmsg_abort = _nlmsg_abort, 182 .nlmsg_get_unicast_writer = _nlmsg_get_unicast_writer, 183 .nlmsg_get_group_writer = _nlmsg_get_group_writer, 184 .nlmsg_end_dump = _nlmsg_end_dump, 185 .nl_modify_ifp_generic = _nl_modify_ifp_generic, 186 .nl_store_ifp_cookie = _nl_store_ifp_cookie, 187 .nl_get_thread_nlp = _nl_get_thread_nlp, 188 }; 189 #endif 190 191 static bool 192 can_unload(void) 193 { 194 struct nl_control *ctl; 195 bool result = true; 196 197 NL_GLOBAL_LOCK(); 198 199 CK_LIST_FOREACH(ctl, &vnets_head, ctl_next) { 200 NL_LOG(LOG_DEBUG2, "Iterating VNET head %p", ctl); 201 if (!CK_LIST_EMPTY(&ctl->ctl_pcb_head)) { 202 NL_LOG(LOG_NOTICE, "non-empty socket list in ctl %p", ctl); 203 result = false; 204 break; 205 } 206 } 207 208 NL_GLOBAL_UNLOCK(); 209 210 return (result); 211 } 212 213 static int 214 netlink_modevent(module_t mod __unused, int what, void *priv __unused) 215 { 216 int ret = 0; 217 218 switch (what) { 219 case MOD_LOAD: 220 NL_LOG(LOG_DEBUG2, "Loading"); 221 nl_osd_register(); 222 #if !defined(NETLINK) && defined(NETLINK_MODULE) 223 nl_set_functions(&nl_module); 224 #endif 225 break; 226 227 case MOD_UNLOAD: 228 NL_LOG(LOG_DEBUG2, "Unload called"); 229 if (can_unload()) { 230 NL_LOG(LOG_WARNING, "unloading"); 231 netlink_unloading = 1; 232 #if !defined(NETLINK) && defined(NETLINK_MODULE) 233 nl_set_functions(NULL); 234 #endif 235 nl_osd_unregister(); 236 } else 237 ret = EBUSY; 238 break; 239 240 default: 241 ret = EOPNOTSUPP; 242 break; 243 } 244 245 return (ret); 246 } 247 static moduledata_t netlink_mod = { "netlink", netlink_modevent, NULL }; 248 249 DECLARE_MODULE(netlink, netlink_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 250 MODULE_VERSION(netlink, 1); 251