1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2023 Baptiste Daroussin <bapt@FreeBSD.org>
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/param.h>
29 #include <sys/types.h>
30 #include <sys/devctl.h>
31 #include <sys/errno.h>
32 #include <sys/module.h>
33 #include <sys/kernel.h>
34 #include <sys/malloc.h>
35 #include <net/vnet.h>
36 #include <netlink/netlink.h>
37 #include <netlink/netlink_ctl.h>
38 #include <netlink/netlink_generic.h>
39 #include <netlink/netlink_sysevent.h>
40
41 #define DEBUG_MOD_NAME nl_sysevent
42 #define DEBUG_MAX_LEVEL LOG_DEBUG3
43 #include <netlink/netlink_debug.h>
44 _DECLARE_DEBUG(LOG_INFO);
45
46 MALLOC_DEFINE(M_NLSE, "nlsysevent", "Memory used for Netlink sysevent");
47 #define NLSE_FAMILY_NAME "nlsysevent"
48 static uint16_t ctrl_family_id;
49
50 #define MAX_SYSEVENT_GROUPS 64
51 static struct sysevent_group {
52 char *name;
53 uint32_t id;
54 } sysevent_groups[MAX_SYSEVENT_GROUPS] = {};
55
56 static const char *devctl_systems[] = {
57 "ACPI",
58 "AEON",
59 "CAM",
60 "CARP",
61 "coretemp",
62 "DEVFS",
63 "device",
64 "ETHERNET",
65 "GEOM",
66 "HYPERV_NIC_VF",
67 "IFNET",
68 "INFINIBAND",
69 "KERNEL",
70 "nvme",
71 "PMU",
72 "RCTL",
73 "USB",
74 "VFS",
75 "VT",
76 "ZFS",
77 };
78
79 static void
sysevent_write(struct sysevent_group * se,const char * subsystem,const char * type,const char * data)80 sysevent_write(struct sysevent_group *se, const char *subsystem, const char *type,
81 const char *data)
82 {
83 struct nl_writer nw;
84
85 if (!nl_writer_group(&nw, NLMSG_LARGE, NETLINK_GENERIC, se->id, 0,
86 false)) {
87 NL_LOG(LOG_DEBUG, "error allocating group writer");
88 return;
89 }
90 struct nlmsghdr hdr = { .nlmsg_type = ctrl_family_id };
91 if (!nlmsg_reply(&nw, &hdr, sizeof(struct genlmsghdr))) {
92 return;
93 }
94
95 struct genlmsghdr *ghdr = nlmsg_reserve_object(&nw, struct genlmsghdr);
96 if (ghdr == NULL) {
97 NL_LOG(LOG_DEBUG, "unable to allocate memory");
98 return;
99 }
100 ghdr->version = 0;
101 ghdr->cmd = NLSE_CMD_NEWEVENT;
102 ghdr->reserved = 0;
103 nlattr_add_string(&nw, NLSE_ATTR_SYSTEM, se->name);
104 nlattr_add_string(&nw, NLSE_ATTR_SUBSYSTEM, subsystem);
105 nlattr_add_string(&nw, NLSE_ATTR_TYPE, type);
106 if (data != NULL)
107 nlattr_add_string(&nw, NLSE_ATTR_DATA, data);
108 nlmsg_end(&nw);
109 nlmsg_flush(&nw);
110 }
111
112 static void
sysevent_new_group(size_t index,const char * name)113 sysevent_new_group(size_t index, const char *name)
114 {
115 if (index >= MAX_SYSEVENT_GROUPS) {
116 NL_LOG(LOG_WARNING, "impossible to add the event %s, "
117 "too many event groups\n", name);
118 return;
119 }
120 sysevent_groups[index].name = strdup(name, M_NLSE);
121 sysevent_groups[index].id = genl_register_group(ctrl_family_id,
122 sysevent_groups[index].name);
123 }
124
125 static struct sysevent_group *
sysevent_get_group(const char * system)126 sysevent_get_group(const char *system)
127 {
128 for (size_t i = 0; i < MAX_SYSEVENT_GROUPS; i++) {
129 if (sysevent_groups[i].name == NULL) {
130 sysevent_new_group(i, system);
131 return (&sysevent_groups[i]);
132 }
133 if (strcmp(sysevent_groups[i].name, system) == 0)
134 return (&sysevent_groups[i]);
135 }
136
137 return (NULL);
138 }
139
140 static void
sysevent_send(const char * system,const char * subsystem,const char * type,const char * data)141 sysevent_send(const char *system, const char *subsystem, const char *type,
142 const char *data)
143 {
144 struct sysevent_group *se = sysevent_get_group(system);
145
146 if (se == NULL) {
147 NL_LOG(LOG_WARNING, "impossible to add the event %s, "
148 "too many event groups\n", system);
149 return;
150 }
151
152 CURVNET_SET(vnet0);
153 sysevent_write(se, subsystem, type, data);
154 CURVNET_RESTORE();
155 }
156
157 static void
nlsysevent_load(void)158 nlsysevent_load(void)
159 {
160 devctl_set_notify_hook(sysevent_send);
161 ctrl_family_id = genl_register_family(NLSE_FAMILY_NAME, 0, 2, NLSE_ATTR_MAX);
162 for (size_t i = 0; i < nitems(devctl_systems); i++) {
163 if (i >= MAX_SYSEVENT_GROUPS) {
164 NL_LOG(LOG_WARNING, "impossible to add the event %s, too many events\n", devctl_systems[i]);
165 continue;
166 }
167 sysevent_new_group(i, devctl_systems[i]);
168 }
169 }
170
171 static void
nlsysevent_unload(void)172 nlsysevent_unload(void)
173 {
174 devctl_unset_notify_hook();
175 genl_unregister_family(ctrl_family_id);
176 for (size_t i = 0; i < MAX_SYSEVENT_GROUPS; i++) {
177 if (sysevent_groups[i].name == NULL)
178 break;
179 free(sysevent_groups[i].name, M_NLSE);
180 }
181 }
182
183 static int
nlsysevent_loader(module_t mod __unused,int what,void * priv __unused)184 nlsysevent_loader(module_t mod __unused, int what, void *priv __unused)
185 {
186 int err = 0;
187
188 switch (what) {
189 case MOD_LOAD:
190 nlsysevent_load();
191 break;
192 case MOD_UNLOAD:
193 nlsysevent_unload();
194 break;
195 default:
196 err = EOPNOTSUPP;
197 break;
198 }
199 return (err);
200 }
201 static moduledata_t nlsysevent_mod = { "nlsysevent", nlsysevent_loader, NULL};
202
203 DECLARE_MODULE(nlsysevent, nlsysevent_mod, SI_SUB_PSEUDO, SI_ORDER_ANY);
204 MODULE_DEPEND(nlsysevent, netlink, 1, 1, 1);
205 MODULE_VERSION(nlsysevent, 1);
206