blob: dc09d05048f3703ea68e2b83945b001a2a9b7e3b [file] [log] [blame]
/*
* msg.c Messaging (netlink) helper functions.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
* Authors: Richard Alpe <richard.alpe@ericsson.com>
*/
#include <stdio.h>
#include <time.h>
#include <errno.h>
#include <linux/tipc_netlink.h>
#include <linux/tipc.h>
#include <linux/genetlink.h>
#include <libmnl/libmnl.h>
#include "msg.h"
int parse_attrs(const struct nlattr *attr, void *data)
{
const struct nlattr **tb = data;
int type = mnl_attr_get_type(attr);
tb[type] = attr;
return MNL_CB_OK;
}
static int family_id_cb(const struct nlmsghdr *nlh, void *data)
{
struct nlattr *tb[CTRL_ATTR_MAX + 1] = {};
struct genlmsghdr *genl = mnl_nlmsg_get_payload(nlh);
int *id = data;
mnl_attr_parse(nlh, sizeof(*genl), parse_attrs, tb);
if (!tb[CTRL_ATTR_FAMILY_ID])
return MNL_CB_ERROR;
*id = mnl_attr_get_u16(tb[CTRL_ATTR_FAMILY_ID]);
return MNL_CB_OK;
}
static struct mnl_socket *msg_send(struct nlmsghdr *nlh)
{
int ret;
struct mnl_socket *nl;
nl = mnl_socket_open(NETLINK_GENERIC);
if (nl == NULL) {
perror("mnl_socket_open");
return NULL;
}
ret = mnl_socket_bind(nl, 0, MNL_SOCKET_AUTOPID);
if (ret < 0) {
perror("mnl_socket_bind");
return NULL;
}
ret = mnl_socket_sendto(nl, nlh, nlh->nlmsg_len);
if (ret < 0) {
perror("mnl_socket_send");
return NULL;
}
return nl;
}
static int msg_recv(struct mnl_socket *nl, mnl_cb_t callback, void *data, int seq)
{
int ret;
unsigned int portid;
char buf[MNL_SOCKET_BUFFER_SIZE];
portid = mnl_socket_get_portid(nl);
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
while (ret > 0) {
ret = mnl_cb_run(buf, ret, seq, portid, callback, data);
if (ret <= 0)
break;
ret = mnl_socket_recvfrom(nl, buf, sizeof(buf));
}
if (ret == -1)
perror("error");
mnl_socket_close(nl);
return ret;
}
static int msg_query(struct nlmsghdr *nlh, mnl_cb_t callback, void *data)
{
unsigned int seq;
struct mnl_socket *nl;
seq = time(NULL);
nlh->nlmsg_seq = seq;
nl = msg_send(nlh);
if (!nl)
return -ENOTSUP;
return msg_recv(nl, callback, data, seq);
}
static int get_family(void)
{
int err;
int nl_family;
struct nlmsghdr *nlh;
struct genlmsghdr *genl;
char buf[MNL_SOCKET_BUFFER_SIZE];
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = GENL_ID_CTRL;
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));
genl->cmd = CTRL_CMD_GETFAMILY;
genl->version = 1;
mnl_attr_put_u16(nlh, CTRL_ATTR_FAMILY_ID, GENL_ID_CTRL);
mnl_attr_put_strz(nlh, CTRL_ATTR_FAMILY_NAME, TIPC_GENL_V2_NAME);
if ((err = msg_query(nlh, family_id_cb, &nl_family)))
return err;
return nl_family;
}
int msg_doit(struct nlmsghdr *nlh, mnl_cb_t callback, void *data)
{
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
return msg_query(nlh, callback, data);
}
int msg_dumpit(struct nlmsghdr *nlh, mnl_cb_t callback, void *data)
{
nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_DUMP;
return msg_query(nlh, callback, data);
}
struct nlmsghdr *msg_init(char *buf, int cmd)
{
int family;
struct nlmsghdr *nlh;
struct genlmsghdr *genl;
family = get_family();
if (family <= 0) {
fprintf(stderr,
"Unable to get TIPC nl family id (module loaded?)\n");
return NULL;
}
nlh = mnl_nlmsg_put_header(buf);
nlh->nlmsg_type = family;
genl = mnl_nlmsg_put_extra_header(nlh, sizeof(struct genlmsghdr));
genl->cmd = cmd;
genl->version = 1;
return nlh;
}