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 <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 #include <sys/param.h> 32 #include <sys/kernel.h> 33 #include <sys/malloc.h> 34 #include <sys/module.h> 35 36 #include <sys/lock.h> 37 #include <sys/rmlock.h> 38 #include <sys/ck.h> 39 #include <sys/syslog.h> 40 41 #include <netlink/netlink.h> 42 #include <netlink/netlink_ctl.h> 43 #include <netlink/netlink_var.h> 44 45 #include <machine/atomic.h> 46 47 MALLOC_DEFINE(M_NETLINK, "netlink", "Memory used for netlink packets"); 48 49 #define DEBUG_MOD_NAME nl_mod 50 #define DEBUG_MAX_LEVEL LOG_DEBUG3 51 #include <netlink/netlink_debug.h> 52 _DECLARE_DEBUG(LOG_DEBUG); 53 54 SYSCTL_NODE(_net, OID_AUTO, netlink, CTLFLAG_RD, 0, ""); 55 SYSCTL_NODE(_net_netlink, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, ""); 56 57 #define NL_MAX_HANDLERS 20 58 struct nl_proto_handler _nl_handlers[NL_MAX_HANDLERS]; 59 struct nl_proto_handler *nl_handlers = _nl_handlers; 60 61 CK_LIST_HEAD(nl_control_head, nl_control); 62 static struct nl_control_head vnets_head = CK_LIST_HEAD_INITIALIZER(); 63 64 VNET_DEFINE(struct nl_control *, nl_ctl) = NULL; 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 free_nl_ctl(struct nl_control *ctl) 76 { 77 rm_destroy(&ctl->ctl_lock); 78 free(ctl, M_NETLINK); 79 } 80 81 struct nl_control * 82 vnet_nl_ctl_init(void) 83 { 84 struct nl_control *ctl; 85 86 ctl = malloc(sizeof(struct nl_control), M_NETLINK, M_WAITOK | M_ZERO); 87 rm_init(&ctl->ctl_lock, "netlink lock"); 88 CK_LIST_INIT(&ctl->ctl_port_head); 89 CK_LIST_INIT(&ctl->ctl_pcb_head); 90 91 NL_GLOBAL_LOCK(); 92 93 struct nl_control *tmp = atomic_load_ptr(&V_nl_ctl); 94 95 if (tmp == NULL) { 96 atomic_store_ptr(&V_nl_ctl, ctl); 97 CK_LIST_INSERT_HEAD(&vnets_head, ctl, ctl_next); 98 NL_LOG(LOG_DEBUG2, "VNET %p init done, inserted %p into global list", 99 curvnet, ctl); 100 } else { 101 NL_LOG(LOG_DEBUG, "per-VNET init clash, dropping this instance"); 102 free_nl_ctl(ctl); 103 ctl = tmp; 104 } 105 106 NL_GLOBAL_UNLOCK(); 107 108 return (ctl); 109 } 110 111 static void 112 vnet_nl_ctl_destroy(const void *unused __unused) 113 { 114 struct nl_control *ctl; 115 116 /* Assume at the time all of the processes / sockets are dead */ 117 118 NL_GLOBAL_LOCK(); 119 ctl = atomic_load_ptr(&V_nl_ctl); 120 atomic_store_ptr(&V_nl_ctl, NULL); 121 if (ctl != NULL) { 122 NL_LOG(LOG_DEBUG2, "Removing %p from global list", ctl); 123 CK_LIST_REMOVE(ctl, ctl_next); 124 } 125 NL_GLOBAL_UNLOCK(); 126 127 if (ctl != NULL) 128 free_nl_ctl(ctl); 129 } 130 VNET_SYSUNINIT(vnet_nl_ctl_destroy, SI_SUB_PROTO_IF, SI_ORDER_ANY, 131 vnet_nl_ctl_destroy, NULL); 132 133 int 134 nl_verify_proto(int proto) 135 { 136 if (proto < 0 || proto >= NL_MAX_HANDLERS) { 137 return (EINVAL); 138 } 139 int handler_defined = nl_handlers[proto].cb != NULL; 140 return (handler_defined ? 0 : EPROTONOSUPPORT); 141 } 142 143 const char * 144 nl_get_proto_name(int proto) 145 { 146 return (nl_handlers[proto].proto_name); 147 } 148 149 bool 150 netlink_register_proto(int proto, const char *proto_name, nl_handler_f handler) 151 { 152 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 153 return (false); 154 NL_GLOBAL_LOCK(); 155 KASSERT((nl_handlers[proto].cb == NULL), ("netlink handler %d is already set", proto)); 156 nl_handlers[proto].cb = handler; 157 nl_handlers[proto].proto_name = proto_name; 158 NL_GLOBAL_UNLOCK(); 159 NL_LOG(LOG_DEBUG, "Registered netlink %s(%d) handler", proto_name, proto); 160 return (true); 161 } 162 163 bool 164 netlink_unregister_proto(int proto) 165 { 166 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 167 return (false); 168 NL_GLOBAL_LOCK(); 169 KASSERT((nl_handlers[proto].cb != NULL), ("netlink handler %d is not set", proto)); 170 nl_handlers[proto].cb = NULL; 171 nl_handlers[proto].proto_name = NULL; 172 NL_GLOBAL_UNLOCK(); 173 NL_LOG(LOG_DEBUG, "Unregistered netlink proto %d handler", proto); 174 return (true); 175 } 176 177 static bool 178 can_unload(void) 179 { 180 struct nl_control *ctl; 181 bool result = true; 182 183 NL_GLOBAL_LOCK(); 184 185 CK_LIST_FOREACH(ctl, &vnets_head, ctl_next) { 186 NL_LOG(LOG_DEBUG2, "Iterating VNET head %p", ctl); 187 if (!CK_LIST_EMPTY(&ctl->ctl_pcb_head)) { 188 NL_LOG(LOG_NOTICE, "non-empty socket list in ctl %p", ctl); 189 result = false; 190 break; 191 } 192 } 193 194 NL_GLOBAL_UNLOCK(); 195 196 return (result); 197 } 198 199 static int 200 netlink_modevent(module_t mod __unused, int what, void *priv __unused) 201 { 202 int ret = 0; 203 204 switch (what) { 205 case MOD_LOAD: 206 NL_LOG(LOG_DEBUG, "Loading"); 207 NL_LOG(LOG_NOTICE, "netlink support is in BETA stage"); 208 break; 209 210 case MOD_UNLOAD: 211 NL_LOG(LOG_DEBUG, "Unload called"); 212 if (can_unload()) { 213 NL_LOG(LOG_WARNING, "unloading"); 214 netlink_unloading = 1; 215 } else 216 ret = EBUSY; 217 break; 218 219 default: 220 ret = EOPNOTSUPP; 221 break; 222 } 223 224 return (ret); 225 } 226 static moduledata_t netlink_mod = { "netlink", netlink_modevent, NULL }; 227 228 DECLARE_MODULE(netlink, netlink_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 229 MODULE_VERSION(netlink, 1); 230