1 // SPDX-License-Identifier: LGPL-2.1+
2 // Copyright (C) 2022, Linaro Ltd - Daniel Lezcano <daniel.lezcano@linaro.org>
3 #include <errno.h>
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <unistd.h>
7
8 #include <thermal.h>
9 #include "thermal_nl.h"
10
11 struct handler_args {
12 const char *group;
13 int id;
14 };
15
16 static __thread int err;
17 static __thread int done;
18
nl_seq_check_handler(struct nl_msg * msg,void * arg)19 static int nl_seq_check_handler(struct nl_msg *msg, void *arg)
20 {
21 return NL_OK;
22 }
23
nl_error_handler(struct sockaddr_nl * nla,struct nlmsgerr * nl_err,void * arg)24 static int nl_error_handler(struct sockaddr_nl *nla, struct nlmsgerr *nl_err,
25 void *arg)
26 {
27 int *ret = arg;
28
29 if (ret)
30 *ret = nl_err->error;
31
32 return NL_STOP;
33 }
34
nl_finish_handler(struct nl_msg * msg,void * arg)35 static int nl_finish_handler(struct nl_msg *msg, void *arg)
36 {
37 int *ret = arg;
38
39 if (ret)
40 *ret = 1;
41
42 return NL_OK;
43 }
44
nl_ack_handler(struct nl_msg * msg,void * arg)45 static int nl_ack_handler(struct nl_msg *msg, void *arg)
46 {
47 int *ret = arg;
48
49 if (ret)
50 *ret = 1;
51
52 return NL_OK;
53 }
54
nl_send_msg(struct nl_sock * sock,struct nl_cb * cb,struct nl_msg * msg,int (* rx_handler)(struct nl_msg *,void *),void * data)55 int nl_send_msg(struct nl_sock *sock, struct nl_cb *cb, struct nl_msg *msg,
56 int (*rx_handler)(struct nl_msg *, void *), void *data)
57 {
58 if (!rx_handler)
59 return THERMAL_ERROR;
60
61 err = nl_send_auto_complete(sock, msg);
62 if (err < 0)
63 return err;
64
65 nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, rx_handler, data);
66
67 err = done = 0;
68
69 while (err == 0 && done == 0)
70 nl_recvmsgs(sock, cb);
71
72 return err;
73 }
74
nl_family_handler(struct nl_msg * msg,void * arg)75 static int nl_family_handler(struct nl_msg *msg, void *arg)
76 {
77 struct handler_args *grp = arg;
78 struct nlattr *tb[CTRL_ATTR_MAX + 1];
79 struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
80 struct nlattr *mcgrp;
81 int rem_mcgrp;
82
83 nla_parse(tb, CTRL_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
84 genlmsg_attrlen(gnlh, 0), NULL);
85
86 if (!tb[CTRL_ATTR_MCAST_GROUPS])
87 return THERMAL_ERROR;
88
89 nla_for_each_nested(mcgrp, tb[CTRL_ATTR_MCAST_GROUPS], rem_mcgrp) {
90
91 struct nlattr *tb_mcgrp[CTRL_ATTR_MCAST_GRP_MAX + 1];
92
93 nla_parse(tb_mcgrp, CTRL_ATTR_MCAST_GRP_MAX,
94 nla_data(mcgrp), nla_len(mcgrp), NULL);
95
96 if (!tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME] ||
97 !tb_mcgrp[CTRL_ATTR_MCAST_GRP_ID])
98 continue;
99
100 if (strncmp(nla_data(tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME]),
101 grp->group,
102 nla_len(tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME])))
103 continue;
104
105 grp->id = nla_get_u32(tb_mcgrp[CTRL_ATTR_MCAST_GRP_ID]);
106
107 break;
108 }
109
110 return THERMAL_SUCCESS;
111 }
112
nl_get_multicast_id(struct nl_sock * sock,struct nl_cb * cb,const char * family,const char * group)113 static int nl_get_multicast_id(struct nl_sock *sock, struct nl_cb *cb,
114 const char *family, const char *group)
115 {
116 struct nl_msg *msg;
117 int ret = 0, ctrlid;
118 struct handler_args grp = {
119 .group = group,
120 .id = -ENOENT,
121 };
122
123 msg = nlmsg_alloc();
124 if (!msg)
125 return THERMAL_ERROR;
126
127 ctrlid = genl_ctrl_resolve(sock, "nlctrl");
128
129 genlmsg_put(msg, 0, 0, ctrlid, 0, 0, CTRL_CMD_GETFAMILY, 0);
130
131 nla_put_string(msg, CTRL_ATTR_FAMILY_NAME, family);
132
133 ret = nl_send_msg(sock, cb, msg, nl_family_handler, &grp);
134 if (ret)
135 goto nla_put_failure;
136
137 ret = grp.id;
138
139 nla_put_failure:
140 nlmsg_free(msg);
141 return ret;
142 }
143
nl_thermal_connect(struct nl_sock ** nl_sock,struct nl_cb ** nl_cb)144 int nl_thermal_connect(struct nl_sock **nl_sock, struct nl_cb **nl_cb)
145 {
146 struct nl_cb *cb;
147 struct nl_sock *sock;
148
149 cb = nl_cb_alloc(NL_CB_DEFAULT);
150 if (!cb)
151 return THERMAL_ERROR;
152
153 sock = nl_socket_alloc();
154 if (!sock)
155 goto out_cb_free;
156
157 if (genl_connect(sock))
158 goto out_socket_free;
159
160 if (nl_cb_err(cb, NL_CB_CUSTOM, nl_error_handler, &err) ||
161 nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, nl_finish_handler, &done) ||
162 nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, nl_ack_handler, &done) ||
163 nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, nl_seq_check_handler, &done))
164 return THERMAL_ERROR;
165
166 *nl_sock = sock;
167 *nl_cb = cb;
168
169 return THERMAL_SUCCESS;
170
171 out_socket_free:
172 nl_socket_free(sock);
173 out_cb_free:
174 nl_cb_put(cb);
175 return THERMAL_ERROR;
176 }
177
nl_thermal_disconnect(struct nl_sock * nl_sock,struct nl_cb * nl_cb)178 void nl_thermal_disconnect(struct nl_sock *nl_sock, struct nl_cb *nl_cb)
179 {
180 nl_close(nl_sock);
181 nl_socket_free(nl_sock);
182 nl_cb_put(nl_cb);
183 }
184
nl_unsubscribe_thermal(struct nl_sock * nl_sock,struct nl_cb * nl_cb,const char * group)185 int nl_unsubscribe_thermal(struct nl_sock *nl_sock, struct nl_cb *nl_cb,
186 const char *group)
187 {
188 int mcid;
189
190 mcid = nl_get_multicast_id(nl_sock, nl_cb, THERMAL_GENL_FAMILY_NAME,
191 group);
192 if (mcid < 0)
193 return THERMAL_ERROR;
194
195 if (nl_socket_drop_membership(nl_sock, mcid))
196 return THERMAL_ERROR;
197
198 return THERMAL_SUCCESS;
199 }
200
nl_subscribe_thermal(struct nl_sock * nl_sock,struct nl_cb * nl_cb,const char * group)201 int nl_subscribe_thermal(struct nl_sock *nl_sock, struct nl_cb *nl_cb,
202 const char *group)
203 {
204 int mcid;
205
206 mcid = nl_get_multicast_id(nl_sock, nl_cb, THERMAL_GENL_FAMILY_NAME,
207 group);
208 if (mcid < 0)
209 return THERMAL_ERROR;
210
211 if (nl_socket_add_membership(nl_sock, mcid))
212 return THERMAL_ERROR;
213
214 return THERMAL_SUCCESS;
215 }
216