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/malloc.h> 33 #include <sys/module.h> 34 35 #include <sys/lock.h> 36 #include <sys/rmlock.h> 37 #include <sys/ck.h> 38 #include <sys/syslog.h> 39 40 #include <netlink/netlink.h> 41 #include <netlink/netlink_ctl.h> 42 #include <netlink/netlink_var.h> 43 44 #include <machine/atomic.h> 45 46 MALLOC_DEFINE(M_NETLINK, "netlink", "Memory used for netlink packets"); 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_DEBUG); 52 53 SYSCTL_NODE(_net, OID_AUTO, netlink, CTLFLAG_RD, 0, ""); 54 SYSCTL_NODE(_net_netlink, OID_AUTO, debug, CTLFLAG_RD | CTLFLAG_MPSAFE, 0, ""); 55 56 #define NL_MAX_HANDLERS 20 57 struct nl_proto_handler _nl_handlers[NL_MAX_HANDLERS]; 58 struct nl_proto_handler *nl_handlers = _nl_handlers; 59 60 CK_LIST_HEAD(nl_control_head, nl_control); 61 static struct nl_control_head vnets_head = CK_LIST_HEAD_INITIALIZER(); 62 63 VNET_DEFINE(struct nl_control *, nl_ctl) = NULL; 64 65 struct mtx nl_global_mtx; 66 MTX_SYSINIT(nl_global_mtx, &nl_global_mtx, "global netlink lock", MTX_DEF); 67 68 #define NL_GLOBAL_LOCK() mtx_lock(&nl_global_mtx) 69 #define NL_GLOBAL_UNLOCK() mtx_unlock(&nl_global_mtx) 70 71 int netlink_unloading = 0; 72 73 static void 74 free_nl_ctl(struct nl_control *ctl) 75 { 76 rm_destroy(&ctl->ctl_lock); 77 free(ctl, M_NETLINK); 78 } 79 80 struct nl_control * 81 vnet_nl_ctl_init(void) 82 { 83 struct nl_control *ctl; 84 85 ctl = malloc(sizeof(struct nl_control), M_NETLINK, M_WAITOK | M_ZERO); 86 rm_init(&ctl->ctl_lock, "netlink lock"); 87 CK_LIST_INIT(&ctl->ctl_port_head); 88 CK_LIST_INIT(&ctl->ctl_pcb_head); 89 90 NL_GLOBAL_LOCK(); 91 92 struct nl_control *tmp = atomic_load_ptr(&V_nl_ctl); 93 94 if (tmp == NULL) { 95 atomic_store_ptr(&V_nl_ctl, ctl); 96 CK_LIST_INSERT_HEAD(&vnets_head, ctl, ctl_next); 97 NL_LOG(LOG_DEBUG2, "VNET %p init done, inserted %p into global list", 98 curvnet, ctl); 99 } else { 100 NL_LOG(LOG_DEBUG, "per-VNET init clash, dropping this instance"); 101 free_nl_ctl(ctl); 102 ctl = tmp; 103 } 104 105 NL_GLOBAL_UNLOCK(); 106 107 return (ctl); 108 } 109 110 static void 111 vnet_nl_ctl_destroy(const void *unused __unused) 112 { 113 struct nl_control *ctl; 114 115 /* Assume at the time all of the processes / sockets are dead */ 116 117 NL_GLOBAL_LOCK(); 118 ctl = atomic_load_ptr(&V_nl_ctl); 119 atomic_store_ptr(&V_nl_ctl, NULL); 120 if (ctl != NULL) { 121 NL_LOG(LOG_DEBUG2, "Removing %p from global list", ctl); 122 CK_LIST_REMOVE(ctl, ctl_next); 123 } 124 NL_GLOBAL_UNLOCK(); 125 126 if (ctl != NULL) 127 free_nl_ctl(ctl); 128 } 129 VNET_SYSUNINIT(vnet_nl_ctl_destroy, SI_SUB_PROTO_IF, SI_ORDER_ANY, 130 vnet_nl_ctl_destroy, NULL); 131 132 int 133 nl_verify_proto(int proto) 134 { 135 if (proto < 0 || proto >= NL_MAX_HANDLERS) { 136 return (EINVAL); 137 } 138 int handler_defined = nl_handlers[proto].cb != NULL; 139 return (handler_defined ? 0 : EPROTONOSUPPORT); 140 } 141 142 const char * 143 nl_get_proto_name(int proto) 144 { 145 return (nl_handlers[proto].proto_name); 146 } 147 148 bool 149 netlink_register_proto(int proto, const char *proto_name, nl_handler_f handler) 150 { 151 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 152 return (false); 153 NL_GLOBAL_LOCK(); 154 KASSERT((nl_handlers[proto].cb == NULL), ("netlink handler %d is already set", proto)); 155 nl_handlers[proto].cb = handler; 156 nl_handlers[proto].proto_name = proto_name; 157 NL_GLOBAL_UNLOCK(); 158 NL_LOG(LOG_DEBUG, "Registered netlink %s(%d) handler", proto_name, proto); 159 return (true); 160 } 161 162 bool 163 netlink_unregister_proto(int proto) 164 { 165 if ((proto < 0) || (proto >= NL_MAX_HANDLERS)) 166 return (false); 167 NL_GLOBAL_LOCK(); 168 KASSERT((nl_handlers[proto].cb != NULL), ("netlink handler %d is not set", proto)); 169 nl_handlers[proto].cb = NULL; 170 nl_handlers[proto].proto_name = NULL; 171 NL_GLOBAL_UNLOCK(); 172 NL_LOG(LOG_DEBUG, "Unregistered netlink proto %d handler", proto); 173 return (true); 174 } 175 176 static bool 177 can_unload(void) 178 { 179 struct nl_control *ctl; 180 bool result = true; 181 182 NL_GLOBAL_LOCK(); 183 184 CK_LIST_FOREACH(ctl, &vnets_head, ctl_next) { 185 NL_LOG(LOG_DEBUG2, "Iterating VNET head %p", ctl); 186 if (!CK_LIST_EMPTY(&ctl->ctl_pcb_head)) { 187 NL_LOG(LOG_NOTICE, "non-empty socket list in ctl %p", ctl); 188 result = false; 189 break; 190 } 191 } 192 193 NL_GLOBAL_UNLOCK(); 194 195 return (result); 196 } 197 198 static int 199 netlink_modevent(module_t mod __unused, int what, void *priv __unused) 200 { 201 int ret = 0; 202 203 switch (what) { 204 case MOD_LOAD: 205 NL_LOG(LOG_DEBUG, "Loading"); 206 NL_LOG(LOG_NOTICE, "netlink support is in BETA stage"); 207 break; 208 209 case MOD_UNLOAD: 210 NL_LOG(LOG_DEBUG, "Unload called"); 211 if (can_unload()) { 212 NL_LOG(LOG_WARNING, "unloading"); 213 netlink_unloading = 1; 214 } else 215 ret = EBUSY; 216 break; 217 218 default: 219 ret = EOPNOTSUPP; 220 break; 221 } 222 223 return (ret); 224 } 225 static moduledata_t netlink_mod = { "netlink", netlink_modevent, NULL }; 226 227 DECLARE_MODULE(netlink, netlink_mod, SI_SUB_PSEUDO, SI_ORDER_ANY); 228 MODULE_VERSION(netlink, 1); 229