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) = { 62 .ctl_port_head = CK_LIST_HEAD_INITIALIZER(), 63 .ctl_pcb_head = CK_LIST_HEAD_INITIALIZER(), 64 }; 65 66 struct mtx nl_global_mtx; 67 MTX_SYSINIT(nl_global_mtx, &nl_global_mtx, "global netlink lock", MTX_DEF); 68 69 #define NL_GLOBAL_LOCK() mtx_lock(&nl_global_mtx) 70 #define NL_GLOBAL_UNLOCK() mtx_unlock(&nl_global_mtx) 71 72 int netlink_unloading = 0; 73 74 static void 75 vnet_nl_init(const void *unused __unused) 76 { 77 rm_init(&V_nl_ctl.ctl_lock, "netlink lock"); 78 79 NL_GLOBAL_LOCK(); 80 CK_LIST_INSERT_HEAD(&vnets_head, &V_nl_ctl, ctl_next); 81 NL_LOG(LOG_DEBUG2, "VNET %p init done, inserted %p into global list", 82 curvnet, &V_nl_ctl); 83 NL_GLOBAL_UNLOCK(); 84 } 85 VNET_SYSINIT(vnet_nl_init, SI_SUB_INIT_IF, SI_ORDER_FIRST, vnet_nl_init, NULL); 86 87 static void 88 vnet_nl_uninit(const void *unused __unused) 89 { 90 /* Assume at the time all of the processes / sockets are dead */ 91 NL_GLOBAL_LOCK(); 92 NL_LOG(LOG_DEBUG2, "Removing %p from global list", &V_nl_ctl); 93 CK_LIST_REMOVE(&V_nl_ctl, ctl_next); 94 NL_GLOBAL_UNLOCK(); 95 96 rm_destroy(&V_nl_ctl.ctl_lock); 97 } 98 VNET_SYSUNINIT(vnet_nl_uninit, SI_SUB_INIT_IF, SI_ORDER_FIRST, vnet_nl_uninit, 99 NULL); 100 101 int 102 nl_verify_proto(int proto) 103 { 104 if (proto < 0 || proto >= NL_MAX_HANDLERS) { 105 return (EINVAL); 106 } 107 int handler_defined = nl_handlers[proto].cb != NULL; 108 return (handler_defined ? 0 : EPROTONOSUPPORT); 109 } 110 111 const char * 112 nl_get_proto_name(int proto) 113 { 114 return (nl_handlers[proto].proto_name); 115 } 116 117 bool 118 netlink_register_proto(int proto, const char *proto_name, nl_handler_f handler) 119 { 120 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 121 return (false); 122 NL_GLOBAL_LOCK(); 123 KASSERT((nl_handlers[proto].cb == NULL), ("netlink handler %d is already set", proto)); 124 nl_handlers[proto].cb = handler; 125 nl_handlers[proto].proto_name = proto_name; 126 NL_GLOBAL_UNLOCK(); 127 NL_LOG(LOG_DEBUG2, "Registered netlink %s(%d) handler", proto_name, proto); 128 return (true); 129 } 130 131 bool 132 netlink_unregister_proto(int proto) 133 { 134 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 135 return (false); 136 NL_GLOBAL_LOCK(); 137 KASSERT((nl_handlers[proto].cb != NULL), ("netlink handler %d is not set", proto)); 138 nl_handlers[proto].cb = NULL; 139 nl_handlers[proto].proto_name = NULL; 140 NL_GLOBAL_UNLOCK(); 141 NL_LOG(LOG_DEBUG2, "Unregistered netlink proto %d handler", proto); 142 return (true); 143 } 144 145 #if !defined(NETLINK) && defined(NETLINK_MODULE) 146 /* Non-stub function provider */ 147 const static struct nl_function_wrapper nl_module = { 148 .nlmsg_add = _nlmsg_add, 149 .nlmsg_refill_buffer = _nlmsg_refill_buffer, 150 .nlmsg_flush = _nlmsg_flush, 151 .nlmsg_end = _nlmsg_end, 152 .nlmsg_abort = _nlmsg_abort, 153 .nl_writer_unicast = _nl_writer_unicast, 154 .nl_writer_group = _nl_writer_group, 155 .nlmsg_end_dump = _nlmsg_end_dump, 156 .nl_modify_ifp_generic = _nl_modify_ifp_generic, 157 .nl_store_ifp_cookie = _nl_store_ifp_cookie, 158 .nl_get_thread_nlp = _nl_get_thread_nlp, 159 }; 160 #endif 161 162 static bool 163 can_unload(void) 164 { 165 struct nl_control *ctl; 166 bool result = true; 167 168 NL_GLOBAL_LOCK(); 169 170 CK_LIST_FOREACH(ctl, &vnets_head, ctl_next) { 171 NL_LOG(LOG_DEBUG2, "Iterating VNET head %p", ctl); 172 if (!CK_LIST_EMPTY(&ctl->ctl_pcb_head)) { 173 NL_LOG(LOG_NOTICE, "non-empty socket list in ctl %p", ctl); 174 result = false; 175 break; 176 } 177 } 178 179 NL_GLOBAL_UNLOCK(); 180 181 return (result); 182 } 183 184 static int 185 netlink_modevent(module_t mod __unused, int what, void *priv __unused) 186 { 187 int ret = 0; 188 189 switch (what) { 190 case MOD_LOAD: 191 NL_LOG(LOG_DEBUG2, "Loading"); 192 nl_osd_register(); 193 #if !defined(NETLINK) && defined(NETLINK_MODULE) 194 nl_set_functions(&nl_module); 195 #endif 196 break; 197 198 case MOD_UNLOAD: 199 NL_LOG(LOG_DEBUG2, "Unload called"); 200 if (can_unload()) { 201 NL_LOG(LOG_WARNING, "unloading"); 202 netlink_unloading = 1; 203 #if !defined(NETLINK) && defined(NETLINK_MODULE) 204 nl_set_functions(NULL); 205 #endif 206 nl_osd_unregister(); 207 } else 208 ret = EBUSY; 209 break; 210 211 default: 212 ret = EOPNOTSUPP; 213 break; 214 } 215 216 return (ret); 217 } 218 static moduledata_t netlink_mod = { "netlink", netlink_modevent, NULL }; 219 220 DECLARE_MODULE(netlink, netlink_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 221 MODULE_VERSION(netlink, 1); 222