1 #include <netlink/cli/utils.h>
2 #include <linux/taskstats.h>
3
4 static struct nla_policy attr_policy[TASKSTATS_TYPE_MAX+1] = {
5 [TASKSTATS_TYPE_PID] = { .type = NLA_U32 },
6 [TASKSTATS_TYPE_TGID] = { .type = NLA_U32 },
7 [TASKSTATS_TYPE_STATS] = { .minlen = sizeof(struct taskstats) },
8 [TASKSTATS_TYPE_AGGR_PID] = { .type = NLA_NESTED },
9 [TASKSTATS_TYPE_AGGR_TGID] = { .type = NLA_NESTED },
10 };
11
12
parse_cmd_new(struct nl_cache_ops * unused,struct genl_cmd * cmd,struct genl_info * info,void * arg)13 static int parse_cmd_new(struct nl_cache_ops *unused, struct genl_cmd *cmd,
14 struct genl_info *info, void *arg)
15 {
16 struct nlattr *attrs[TASKSTATS_TYPE_MAX+1];
17 struct nlattr *nested;
18 int err;
19
20 if (info->attrs[TASKSTATS_TYPE_AGGR_PID])
21 nested = info->attrs[TASKSTATS_TYPE_AGGR_PID];
22 else if (info->attrs[TASKSTATS_TYPE_AGGR_TGID])
23 nested = info->attrs[TASKSTATS_TYPE_AGGR_TGID];
24 else {
25 fprintf(stderr, "Invalid taskstats message: Unable to find "
26 "nested attribute/\n");
27 return NL_SKIP;
28 }
29
30 err = nla_parse_nested(attrs, TASKSTATS_TYPE_MAX, nested, attr_policy);
31 if (err < 0) {
32 nl_perror(err, "Error while parsing generic netlink message");
33 return err;
34 }
35
36
37 if (attrs[TASKSTATS_TYPE_STATS]) {
38 struct taskstats *stats = nla_data(attrs[TASKSTATS_TYPE_STATS]);
39
40 printf("%s pid %u uid %u gid %u parent %u\n",
41 stats->ac_comm, stats->ac_pid, stats->ac_uid,
42 stats->ac_gid, stats->ac_ppid);
43 }
44
45 return 0;
46 }
47
parse_cb(struct nl_msg * msg,void * arg)48 static int parse_cb(struct nl_msg *msg, void *arg)
49 {
50 return genl_handle_msg(msg, NULL);
51 }
52
53 static struct genl_cmd cmds[] = {
54 {
55 .c_id = TASKSTATS_CMD_NEW,
56 .c_name = "taskstats_new()",
57 .c_maxattr = TASKSTATS_TYPE_MAX,
58 .c_attr_policy = attr_policy,
59 .c_msg_parser = &parse_cmd_new,
60 },
61 };
62
63 #define ARRAY_SIZE(X) (sizeof(X) / sizeof((X)[0]))
64
65 static struct genl_ops ops = {
66 .o_name = TASKSTATS_GENL_NAME,
67 .o_cmds = cmds,
68 .o_ncmds = ARRAY_SIZE(cmds),
69 };
70
main(int argc,char * argv[])71 int main(int argc, char *argv[])
72 {
73 struct nl_sock *sock;
74 struct nl_msg *msg;
75 void *hdr;
76 int err;
77
78 sock = nl_cli_alloc_socket();
79 nl_cli_connect(sock, NETLINK_GENERIC);
80
81 if ((err = genl_register_family(&ops)) < 0)
82 nl_cli_fatal(err, "Unable to register Generic Netlink family");
83
84 if ((err = genl_ops_resolve(sock, &ops)) < 0)
85 nl_cli_fatal(err, "Unable to resolve family name");
86
87 if (genl_ctrl_resolve(sock, "nlctrl") != GENL_ID_CTRL)
88 nl_cli_fatal(NLE_INVAL, "Resolving of \"nlctrl\" failed");
89
90 msg = nlmsg_alloc();
91 if (msg == NULL)
92 nl_cli_fatal(NLE_NOMEM, "Unable to allocate netlink message");
93
94 hdr = genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, ops.o_id,
95 0, 0, TASKSTATS_CMD_GET, TASKSTATS_GENL_VERSION);
96 if (hdr == NULL)
97 nl_cli_fatal(ENOMEM, "Unable to write genl header");
98
99 if ((err = nla_put_u32(msg, TASKSTATS_CMD_ATTR_PID, 1)) < 0)
100 nl_cli_fatal(err, "Unable to add attribute: %s", nl_geterror(err));
101
102 if ((err = nl_send_auto_complete(sock, msg)) < 0)
103 nl_cli_fatal(err, "Unable to send message: %s", nl_geterror(err));
104
105 nlmsg_free(msg);
106
107 if ((err = nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM,
108 parse_cb, NULL)) < 0)
109 nl_cli_fatal(err, "Unable to modify valid message callback");
110
111 if ((err = nl_recvmsgs_default(sock)) < 0)
112 nl_cli_fatal(err, "Unable to receive message: %s", nl_geterror(err));
113
114 nl_close(sock);
115 nl_socket_free(sock);
116
117 return 0;
118 }
119