libnl-tiny: add unl a convenience wrapper around the libnl api

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@25263 3c298f89-4303-0410-b956-a3cf2f4a3e73

package/libnl-tiny/src/Makefile

@@ -11,7 +11,7 @@ all: $(LIBNAME)
 	$(CC) $(WFLAGS) -c -o $@ $(INCLUDES) $(CFLAGS) $<
 
 LIBNL_OBJ=nl.o handlers.o msg.o attr.o cache.o cache_mngt.o object.o socket.o error.o
-GENL_OBJ=genl.o genl_family.o genl_ctrl.o genl_mngt.o
+GENL_OBJ=genl.o genl_family.o genl_ctrl.o genl_mngt.o unl.o
 
 $(LIBNAME): $(LIBNL_OBJ) $(GENL_OBJ)
 	$(CC) -shared -o $@ $^

package/libnl-tiny/src/include/unl.h

@@ -0,0 +1,46 @@
+#ifndef __UNL_H
+#define __UNL_H
+
+#include <netlink/netlink.h>
+#include <netlink/genl/genl.h>
+#include <netlink/genl/family.h>
+#include <stdbool.h>
+
+struct unl {
+	struct nl_sock *sock;
+	struct nl_cache *cache;
+	struct genl_family *family;
+	char *family_name;
+	int hdrlen;
+	bool loop_done;
+};
+
+int unl_genl_init(struct unl *unl, const char *family);
+void unl_free(struct unl *unl);
+
+typedef int (*unl_cb)(struct nl_msg *, void *);
+
+struct nl_msg *unl_genl_msg(struct unl *unl, int cmd, bool dump);
+int unl_genl_request(struct unl *unl, struct nl_msg *msg, unl_cb handler, void *arg);
+int unl_genl_request_single(struct unl *unl, struct nl_msg *msg, struct nl_msg **dest);
+void unl_genl_loop(struct unl *unl, unl_cb handler, void *arg);
+
+int unl_genl_subscribe(struct unl *unl, const char *name);
+int unl_genl_unsubscribe(struct unl *unl, const char *name);
+
+int unl_nl80211_phy_lookup(const char *name);
+int unl_nl80211_wdev_to_phy(struct unl *unl, int wdev);
+struct nl_msg *unl_nl80211_phy_msg(struct unl *unl, int phy, int cmd, bool dump);
+struct nl_msg *unl_nl80211_vif_msg(struct unl *unl, int dev, int cmd, bool dump);
+
+static inline void unl_loop_done(struct unl *unl)
+{
+	unl->loop_done = true;
+}
+
+static inline struct nlattr *unl_find_attr(struct unl *unl, struct nl_msg *msg, int attr)
+{
+	return nlmsg_find_attr(nlmsg_hdr(msg), unl->hdrlen, attr);
+}
+
+#endif

package/libnl-tiny/src/unl.c

@@ -0,0 +1,290 @@
+#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);
+}
+
+static 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)
+		goto nla_put_failure;
+
+	groups = unl_find_attr(unl, msg, CTRL_ATTR_MCAST_GROUPS);
+	if (!groups)
+		goto fail;
+
+	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;
+	}
+
+fail:
+	nlmsg_free(msg);
+nla_put_failure:
+	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;
+}
+
+