2 * acpi_ids.c - ACPI Netlink Group and Family IDs
4 * Copyright (C) 2008 Ted Felix (www.tedfelix.com)
5 * Portions from acpi_genl Copyright (C) Zhang Rui <rui.zhang@intel.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 /* needed by netlink.h, should be in there */
24 #include <arpa/inet.h>
25 #include <linux/types.h>
28 #include "genetlink.h"
29 #include "libnetlink.h"
31 #define GENL_MAX_FAM_GRPS 256
32 #define ACPI_EVENT_FAMILY_NAME "acpi_event"
33 #define ACPI_EVENT_MCAST_GROUP_NAME "acpi_mc_group"
35 static int initialized = 0;
36 static __u16 acpi_event_family_id = 0;
37 static __u32 acpi_event_mcast_group_id = 0;
40 * A CTRL_CMD_GETFAMILY message returns an attribute table that looks
43 * CTRL_ATTR_FAMILY_ID Use this to make sure we get the proper msgs
44 * CTRL_ATTR_MCAST_GROUPS
45 * CTRL_ATTR_MCAST_GRP_NAME
46 * CTRL_ATTR_MCAST_GRP_ID Need this for the group mask
51 get_ctrl_grp_id(struct rtattr *arg)
53 struct rtattr *tb[CTRL_ATTR_MCAST_GRP_MAX + 1];
59 /* nested within the CTRL_ATTR_MCAST_GROUPS attribute are the */
60 /* group name and ID */
61 parse_rtattr_nested(tb, CTRL_ATTR_MCAST_GRP_MAX, arg);
63 /* if either of the entries needed cannot be found, bail */
64 if (!tb[CTRL_ATTR_MCAST_GRP_NAME] || !tb[CTRL_ATTR_MCAST_GRP_ID])
67 /* get the name of this multicast group we've found */
68 name = RTA_DATA(tb[CTRL_ATTR_MCAST_GRP_NAME]);
70 /* if it does not match the ACPI event multicast group name, bail */
71 if (strcmp(name, ACPI_EVENT_MCAST_GROUP_NAME))
74 /* At this point, we've found what we were looking for. We now */
75 /* have the multicast group ID for ACPI events over generic netlink. */
76 acpi_event_mcast_group_id =
77 *((__u32 *)RTA_DATA(tb[CTRL_ATTR_MCAST_GRP_ID]));
82 /* n = the response to a CTRL_CMD_GETFAMILY message */
84 genl_get_mcast_group_id(struct nlmsghdr *n)
87 * Attribute table. Note the type name "rtattr" which means "route
88 * attribute". This is a vestige of one of netlink's main uses:
91 struct rtattr *tb[CTRL_ATTR_MAX + 1];
92 /* place for the generic netlink header in the incoming message */
93 struct genlmsghdr ghdr;
94 /* length of the attribute and payload */
95 int len = n->nlmsg_len - NLMSG_LENGTH(GENL_HDRLEN);
96 /* Pointer to the attribute portion of the message */
100 printf("Netlink: CTRL_CMD_GETFAMILY response, "
101 "wrong controller message len: %d\n", len);
105 if (n->nlmsg_type != GENL_ID_CTRL) {
106 printf("Netlink: Not a controller message, nlmsg_len=%d "
107 "nlmsg_type=0x%x\n", n->nlmsg_len, n->nlmsg_type);
111 /* copy generic netlink header into structure */
112 memcpy(&ghdr, NLMSG_DATA(n), GENL_HDRLEN);
114 if (ghdr.cmd != CTRL_CMD_GETFAMILY &&
115 ghdr.cmd != CTRL_CMD_DELFAMILY &&
116 ghdr.cmd != CTRL_CMD_NEWFAMILY &&
117 ghdr.cmd != CTRL_CMD_NEWMCAST_GRP &&
118 ghdr.cmd != CTRL_CMD_DELMCAST_GRP) {
119 printf("Netlink: Unknown controller command %d\n", ghdr.cmd);
123 /* set attrs to point to the attribute */
124 attrs = (struct rtattr *)(NLMSG_DATA(n) + GENL_HDRLEN);
125 /* Read the table from the message into "tb". This actually just */
126 /* places pointers into the message into tb[]. */
127 parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);
129 /* if a family ID attribute is present, get it */
130 if (tb[CTRL_ATTR_FAMILY_ID])
132 acpi_event_family_id =
133 *((__u32 *)RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]));
136 /* if a "multicast groups" attribute is present... */
137 if (tb[CTRL_ATTR_MCAST_GROUPS]) {
138 struct rtattr *tb2[GENL_MAX_FAM_GRPS + 1];
141 /* get the group table within this attribute */
142 parse_rtattr_nested(tb2, GENL_MAX_FAM_GRPS,
143 tb[CTRL_ATTR_MCAST_GROUPS]);
146 for (i = 0; i < GENL_MAX_FAM_GRPS; i++)
147 /* if this group is valid */
149 /* Parse the ID. If successful, we're done. */
150 if (!get_ctrl_grp_id(tb2[i]))
158 genl_get_ids(char *family_name)
160 /* handle to the netlink connection */
161 struct rtnl_handle rth;
162 /* holds the request we are going to send and the reply */
165 char buf[4096]; /* ??? Is this big enough for all cases? */
167 /* pointer to the nlmsghdr in req */
168 struct nlmsghdr *nlh;
169 /* place for the generic netlink header before copied into req */
170 struct genlmsghdr ghdr;
174 /* clear out the request */
175 memset(&req, 0, sizeof(req));
177 /* set up nlh to point to the netlink header in req */
179 /* set up the netlink header */
180 nlh->nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
181 nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
182 nlh->nlmsg_type = GENL_ID_CTRL;
184 /* clear out the generic netlink message header */
185 memset(&ghdr, 0, sizeof(struct genlmsghdr));
186 /* set the command we want to run: "GETFAMILY" */
187 ghdr.cmd = CTRL_CMD_GETFAMILY;
188 /* copy it into req */
189 memcpy(NLMSG_DATA(&req.n), &ghdr, GENL_HDRLEN);
191 /* the message payload is the family name */
192 addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME,
193 family_name, strlen(family_name) + 1);
195 /* open a generic netlink connection */
196 if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
197 printf("Netlink: Cannot open generic netlink socket\n");
202 * Send CTRL_CMD_GETFAMILY message (in nlh) to the generic
203 * netlink controller. Reply will be in nlh upon return.
205 if (rtnl_talk(&rth, nlh, 0, 0, nlh, NULL, NULL) < 0) {
206 printf("Netlink: Error talking to the kernel\n");
210 /* process the response */
211 if (genl_get_mcast_group_id(nlh) < 0) {
212 printf("Netlink: Failed to get acpi_event multicast group\n");
223 /* initialize the ACPI IDs */
227 genl_get_ids(ACPI_EVENT_FAMILY_NAME);
232 /* returns the netlink family ID for ACPI event messages */
236 /* if the IDs haven't been initialized, initialize them */
237 if (initialized == 0)
240 return acpi_event_family_id;
243 /* returns the netlink multicast group ID for ACPI event messages */
247 /* if the IDs haven't been initialized, initialize them */
248 if (initialized == 0)
251 return acpi_event_mcast_group_id;