1 #include <netlink/cli/utils.h>
2
3 #include <linux/taskstats.h>
4 #include <linux/genetlink.h>
5
6 static struct nla_policy attr_policy[TASKSTATS_TYPE_MAX+1] = {
7 [TASKSTATS_TYPE_PID] = { .type = NLA_U32 },
8 [TASKSTATS_TYPE_TGID] = { .type = NLA_U32 },
9 [TASKSTATS_TYPE_STATS] = { .minlen = sizeof(struct taskstats) },
10 [TASKSTATS_TYPE_AGGR_PID] = { .type = NLA_NESTED },
11 [TASKSTATS_TYPE_AGGR_TGID] = { .type = NLA_NESTED },
12 };
13
14
parse_cmd_new(struct nl_cache_ops * unused,struct genl_cmd * cmd,struct genl_info * info,void * arg)15 static int parse_cmd_new(struct nl_cache_ops *unused, struct genl_cmd *cmd,
16 struct genl_info *info, void *arg)
17 {
18 struct nlattr *attrs[TASKSTATS_TYPE_MAX+1];
19 struct nlattr *nested;
20 int err;
21
22 if (info->attrs[TASKSTATS_TYPE_AGGR_PID])
23 nested = info->attrs[TASKSTATS_TYPE_AGGR_PID];
24 else if (info->attrs[TASKSTATS_TYPE_AGGR_TGID])
25 nested = info->attrs[TASKSTATS_TYPE_AGGR_TGID];
26 else {
27 fprintf(stderr, "Invalid taskstats message: Unable to find "
28 "nested attribute/\n");
29 return NL_SKIP;
30 }
31
32 err = nla_parse_nested(attrs, TASKSTATS_TYPE_MAX, nested, attr_policy);
33 if (err < 0) {
34 nl_perror(err, "Error while parsing generic netlink message");
35 return err;
36 }
37
38
39 if (attrs[TASKSTATS_TYPE_STATS]) {
40 struct taskstats *stats = nla_data(attrs[TASKSTATS_TYPE_STATS]);
41
42 printf("%s pid %u uid %u gid %u parent %u\n",
43 stats->ac_comm, stats->ac_pid, stats->ac_uid,
44 stats->ac_gid, stats->ac_ppid);
45 }
46
47 return 0;
48 }
49
parse_cb(struct nl_msg * msg,void * arg)50 static int parse_cb(struct nl_msg *msg, void *arg)
51 {
52 return genl_handle_msg(msg, NULL);
53 }
54
55 static struct genl_cmd cmds[] = {
56 {
57 .c_id = TASKSTATS_CMD_NEW,
58 .c_name = "taskstats_new()",
59 .c_maxattr = TASKSTATS_TYPE_MAX,
60 .c_attr_policy = attr_policy,
61 .c_msg_parser = &parse_cmd_new,
62 },
63 };
64
65 #define ARRAY_SIZE(X) (sizeof(X) / sizeof((X)[0]))
66
67 static struct genl_ops ops = {
68 .o_name = TASKSTATS_GENL_NAME,
69 .o_cmds = cmds,
70 .o_ncmds = ARRAY_SIZE(cmds),
71 };
72
main(int argc,char * argv[])73 int main(int argc, char *argv[])
74 {
75 struct nl_sock *sock;
76 struct nl_msg *msg;
77 void *hdr;
78 int err;
79
80 sock = nl_cli_alloc_socket();
81 nl_cli_connect(sock, NETLINK_GENERIC);
82
83 if ((err = genl_register_family(&ops)) < 0)
84 nl_cli_fatal(err, "Unable to register Generic Netlink family");
85
86 if ((err = genl_ops_resolve(sock, &ops)) < 0)
87 nl_cli_fatal(err, "Unable to resolve family name");
88
89 if (genl_ctrl_resolve(sock, "nlctrl") != GENL_ID_CTRL)
90 nl_cli_fatal(NLE_INVAL, "Resolving of \"nlctrl\" failed");
91
92 msg = nlmsg_alloc();
93 if (msg == NULL)
94 nl_cli_fatal(NLE_NOMEM, "Unable to allocate netlink message");
95
96 hdr = genlmsg_put(msg, NL_AUTO_PORT, NL_AUTO_SEQ, ops.o_id,
97 0, 0, TASKSTATS_CMD_GET, TASKSTATS_GENL_VERSION);
98 if (hdr == NULL)
99 nl_cli_fatal(ENOMEM, "Unable to write genl header");
100
101 if ((err = nla_put_u32(msg, TASKSTATS_CMD_ATTR_PID, 1)) < 0)
102 nl_cli_fatal(err, "Unable to add attribute: %s", nl_geterror(err));
103
104 if ((err = nl_send_auto(sock, msg)) < 0)
105 nl_cli_fatal(err, "Unable to send message: %s", nl_geterror(err));
106
107 nlmsg_free(msg);
108
109 if ((err = nl_socket_modify_cb(sock, NL_CB_VALID, NL_CB_CUSTOM,
110 parse_cb, NULL)) < 0)
111 nl_cli_fatal(err, "Unable to modify valid message callback");
112
113 if ((err = nl_recvmsgs_default(sock)) < 0)
114 nl_cli_fatal(err, "Unable to receive message: %s", nl_geterror(err));
115
116 nl_close(sock);
117 nl_socket_free(sock);
118
119 return 0;
120 }
121