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
vnet_nl_init(const void * unused __unused)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
vnet_nl_uninit(const void * unused __unused)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
nl_verify_proto(int proto)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 *
nl_get_proto_name(int proto)112 nl_get_proto_name(int proto)
113 {
114 return (nl_handlers[proto].proto_name);
115 }
116
117 bool
netlink_register_proto(int proto,const char * proto_name,nl_handler_f handler)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
netlink_unregister_proto(int proto)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
can_unload(void)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
netlink_modevent(module_t mod __unused,int what,void * priv __unused)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