118 lines
2.4 KiB
C
118 lines
2.4 KiB
C
/*
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* This ought to be provided by libnl
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*/
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#include <asm/errno.h>
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#include <netlink/genl/genl.h>
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#include <netlink/genl/family.h>
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#include <netlink/genl/ctrl.h>
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#include <netlink/msg.h>
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#include <netlink/attr.h>
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#include <linux/genetlink.h>
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#include "iw.h"
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static int error_handler(struct sockaddr_nl *nla, struct nlmsgerr *err,
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void *arg)
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{
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int *ret = arg;
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*ret = err->error;
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return NL_STOP;
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}
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static int ack_handler(struct nl_msg *msg, void *arg)
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{
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int *ret = arg;
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*ret = 0;
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return NL_STOP;
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}
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struct handler_args {
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const char *group;
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int id;
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};
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static int family_handler(struct nl_msg *msg, void *arg)
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{
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struct handler_args *grp = arg;
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struct nlattr *tb[CTRL_ATTR_MAX + 1];
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struct genlmsghdr *gnlh = nlmsg_data(nlmsg_hdr(msg));
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struct nlattr *mcgrp;
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int rem_mcgrp;
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nla_parse(tb, CTRL_ATTR_MAX, genlmsg_attrdata(gnlh, 0),
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genlmsg_attrlen(gnlh, 0), NULL);
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if (!tb[CTRL_ATTR_MCAST_GROUPS])
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return NL_SKIP;
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nla_for_each_nested(mcgrp, tb[CTRL_ATTR_MCAST_GROUPS], rem_mcgrp) {
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struct nlattr *tb_mcgrp[CTRL_ATTR_MCAST_GRP_MAX + 1];
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nla_parse(tb_mcgrp, CTRL_ATTR_MCAST_GRP_MAX,
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nla_data(mcgrp), nla_len(mcgrp), NULL);
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if (!tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME] ||
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!tb_mcgrp[CTRL_ATTR_MCAST_GRP_ID])
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continue;
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if (strncmp(nla_data(tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME]),
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grp->group, nla_len(tb_mcgrp[CTRL_ATTR_MCAST_GRP_NAME])))
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continue;
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grp->id = nla_get_u32(tb_mcgrp[CTRL_ATTR_MCAST_GRP_ID]);
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break;
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}
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return NL_SKIP;
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}
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int nl_get_multicast_id(struct nl_sock *sock, const char *family, const char *group)
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{
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struct nl_msg *msg;
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struct nl_cb *cb;
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int ret, ctrlid;
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struct handler_args grp = {
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.group = group,
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.id = -ENOENT,
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};
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msg = nlmsg_alloc();
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if (!msg)
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return -ENOMEM;
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cb = nl_cb_alloc(NL_CB_DEFAULT);
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if (!cb) {
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ret = -ENOMEM;
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goto out_fail_cb;
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}
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ctrlid = genl_ctrl_resolve(sock, "nlctrl");
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genlmsg_put(msg, 0, 0, ctrlid, 0,
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0, CTRL_CMD_GETFAMILY, 0);
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ret = -ENOBUFS;
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NLA_PUT_STRING(msg, CTRL_ATTR_FAMILY_NAME, family);
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ret = nl_send_auto_complete(sock, msg);
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if (ret < 0)
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goto out;
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ret = 1;
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nl_cb_err(cb, NL_CB_CUSTOM, error_handler, &ret);
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nl_cb_set(cb, NL_CB_ACK, NL_CB_CUSTOM, ack_handler, &ret);
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nl_cb_set(cb, NL_CB_VALID, NL_CB_CUSTOM, family_handler, &grp);
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while (ret > 0)
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nl_recvmsgs(sock, cb);
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if (ret == 0)
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ret = grp.id;
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nla_put_failure:
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out:
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nl_cb_put(cb);
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out_fail_cb:
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nlmsg_free(msg);
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return ret;
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}
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