openwrt/package/libs/libnl-tiny/src/unl.c

291 lines
5.3 KiB
C

#define _GNU_SOURCE
#include <netlink/netlink.h>
#include <netlink/genl/genl.h>
#include <netlink/genl/ctrl.h>
#include <netlink/genl/family.h>
#include <sys/types.h>
#include <net/if.h>
#include <unistd.h>
#include <fcntl.h>
#include <linux/nl80211.h>
#include "unl.h"
static int unl_init(struct unl *unl)
{
unl->sock = nl_socket_alloc();
if (!unl->sock)
return -1;
return 0;
}
int unl_genl_init(struct unl *unl, const char *family)
{
memset(unl, 0, sizeof(*unl));
if (unl_init(unl))
goto error_out;
unl->hdrlen = NLMSG_ALIGN(sizeof(struct genlmsghdr));
unl->family_name = strdup(family);
if (!unl->family_name)
goto error;
if (genl_connect(unl->sock))
goto error;
if (genl_ctrl_alloc_cache(unl->sock, &unl->cache))
goto error;
unl->family = genl_ctrl_search_by_name(unl->cache, family);
if (!unl->family)
goto error;
return 0;
error:
unl_free(unl);
error_out:
return -1;
}
void unl_free(struct unl *unl)
{
if (unl->family_name)
free(unl->family_name);
if (unl->sock)
nl_socket_free(unl->sock);
if (unl->cache)
nl_cache_free(unl->cache);
memset(unl, 0, sizeof(*unl));
}
static int
ack_handler(struct nl_msg *msg, void *arg)
{
int *err = arg;
*err = 0;
return NL_STOP;
}
static int
finish_handler(struct nl_msg *msg, void *arg)
{
int *err = arg;
*err = 0;
return NL_SKIP;
}
static int
error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err, void *arg)
{
int *ret = arg;
*ret = err->error;
return NL_SKIP;
}
struct nl_msg *unl_genl_msg(struct unl *unl, int cmd, bool dump)
{
struct nl_msg *msg;
int flags = 0;
msg = nlmsg_alloc();
if (!msg)
goto out;
if (dump)
flags |= NLM_F_DUMP;
genlmsg_put(msg, NL_AUTO_PID, NL_AUTO_SEQ,
genl_family_get_id(unl->family), 0, flags, cmd, 0);
out:
return msg;
}
int unl_genl_request(struct unl *unl, struct nl_msg *msg, unl_cb handler, void *arg)
{
struct nlmsghdr *nlh;
struct nl_cb *cb;
int err;
cb = nl_cb_alloc(NL_CB_CUSTOM);
nlh = nlmsg_hdr(msg);
err = nl_send_auto_complete(unl->sock, msg);
if (err < 0)
goto out;
err = 1;
nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &err);
nl_cb_set(cb, NL_CB_FINISH, NL_CB_CUSTOM, finish_handler, &err);
nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &err);
if (handler)
nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, handler, arg);
while (err > 0)
nl_recvmsgs(unl->sock, cb);
out:
nlmsg_free(msg);
nl_cb_put(cb);
return err;
}
static int request_single_cb(struct nl_msg *msg, void *arg)
{
struct nl_msg **dest = arg;
if (!*dest) {
nlmsg_get(msg);
*dest = msg;
}
return NL_SKIP;
}
int unl_genl_request_single(struct unl *unl, struct nl_msg *msg, struct nl_msg **dest)
{
*dest = NULL;
return unl_genl_request(unl, msg, request_single_cb, dest);
}
static int no_seq_check(struct nl_msg *msg, void *arg)
{
return NL_OK;
}
void unl_genl_loop(struct unl *unl, unl_cb handler, void *arg)
{
struct nl_cb *cb;
cb = nl_cb_alloc(NL_CB_CUSTOM);
unl->loop_done = false;
nl_cb_set(cb, NL_CB_SEQ_CHECK, NL_CB_CUSTOM, no_seq_check, NULL);
nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, handler, arg);
while (!unl->loop_done)
nl_recvmsgs(unl->sock, cb);
nl_cb_put(cb);
}
int unl_genl_multicast_id(struct unl *unl, const char *name)
{
struct nlattr *tb[CTRL_ATTR_MCAST_GRP_MAX + 1];
struct nlattr *groups, *group;
struct nl_msg *msg;
int ctrlid;
int ret = -1;
int rem;
msg = nlmsg_alloc();
if (!msg)
return -1;
ctrlid = genl_ctrl_resolve(unl->sock, "nlctrl");
genlmsg_put(msg, 0, 0, ctrlid, 0, 0, CTRL_CMD_GETFAMILY, 0);
NLA_PUT_STRING(msg, CTRL_ATTR_FAMILY_NAME, unl->family_name);
unl_genl_request_single(unl, msg, &msg);
if (!msg)
return -1;
groups = unl_find_attr(unl, msg, CTRL_ATTR_MCAST_GROUPS);
if (!groups)
goto nla_put_failure;
nla_for_each_nested(group, groups, rem) {
const char *gn;
nla_parse(tb, CTRL_ATTR_MCAST_GRP_MAX, nla_data(group),
nla_len(group), NULL);
if (!tb[CTRL_ATTR_MCAST_GRP_NAME] ||
!tb[CTRL_ATTR_MCAST_GRP_ID])
continue;
gn = nla_data(tb[CTRL_ATTR_MCAST_GRP_NAME]);
if (strcmp(gn, name) != 0)
continue;
ret = nla_get_u32(tb[CTRL_ATTR_MCAST_GRP_ID]);
break;
}
nla_put_failure:
nlmsg_free(msg);
return ret;
}
int unl_genl_subscribe(struct unl *unl, const char *name)
{
int mcid;
mcid = unl_genl_multicast_id(unl, name);
if (mcid < 0)
return mcid;
return nl_socket_add_membership(unl->sock, mcid);
}
int unl_genl_unsubscribe(struct unl *unl, const char *name)
{
int mcid;
mcid = unl_genl_multicast_id(unl, name);
if (mcid < 0)
return mcid;
return nl_socket_drop_membership(unl->sock, mcid);
}
int unl_nl80211_phy_lookup(const char *name)
{
char buf[32];
int fd, pos;
snprintf(buf, sizeof(buf), "/sys/class/ieee80211/%s/index", name);
fd = open(buf, O_RDONLY);
if (fd < 0)
return -1;
pos = read(fd, buf, sizeof(buf) - 1);
if (pos < 0) {
close(fd);
return -1;
}
buf[pos] = '\0';
close(fd);
return atoi(buf);
}
int unl_nl80211_wdev_to_phy(struct unl *unl, int wdev)
{
struct nl_msg *msg;
struct nlattr *attr;
int ret = -1;
msg = unl_genl_msg(unl, NL80211_CMD_GET_INTERFACE, false);
if (!msg)
return -1;
NLA_PUT_U32(msg, NL80211_ATTR_IFINDEX, wdev);
if (unl_genl_request_single(unl, msg, &msg) < 0)
return -1;
attr = unl_find_attr(unl, msg, NL80211_ATTR_WIPHY);
if (!attr)
goto out;
ret = nla_get_u32(attr);
out:
nla_put_failure:
nlmsg_free(msg);
return ret;
}