static int get_response(struct nlmsghdr *n, void *arg)
{
	struct genlmsghdr *ghdr;
	struct l2tp_data *data = arg;
	struct l2tp_parm *p = &data->config;
	struct rtattr *attrs[L2TP_ATTR_MAX + 1];
	struct rtattr *nla_stats;
	int len;

	/* Validate message and parse attributes */
	if (n->nlmsg_type == NLMSG_ERROR)
		return -EBADMSG;

	ghdr = NLMSG_DATA(n);
	len = n->nlmsg_len - NLMSG_LENGTH(sizeof(*ghdr));
	if (len < 0)
		return -1;

	parse_rtattr(attrs, L2TP_ATTR_MAX, (void *)ghdr + GENL_HDRLEN, len);

	if (attrs[L2TP_ATTR_PW_TYPE])
		p->pw_type = rta_getattr_u16(attrs[L2TP_ATTR_PW_TYPE]);
	if (attrs[L2TP_ATTR_ENCAP_TYPE])
		p->encap = rta_getattr_u16(attrs[L2TP_ATTR_ENCAP_TYPE]);
	if (attrs[L2TP_ATTR_OFFSET])
		p->offset = rta_getattr_u16(attrs[L2TP_ATTR_OFFSET]);
	if (attrs[L2TP_ATTR_DATA_SEQ])
		p->data_seq = rta_getattr_u16(attrs[L2TP_ATTR_DATA_SEQ]);
	if (attrs[L2TP_ATTR_CONN_ID])
		p->tunnel_id = rta_getattr_u32(attrs[L2TP_ATTR_CONN_ID]);
	if (attrs[L2TP_ATTR_PEER_CONN_ID])
		p->peer_tunnel_id = rta_getattr_u32(attrs[L2TP_ATTR_PEER_CONN_ID]);
	if (attrs[L2TP_ATTR_SESSION_ID])
		p->session_id = rta_getattr_u32(attrs[L2TP_ATTR_SESSION_ID]);
	if (attrs[L2TP_ATTR_PEER_SESSION_ID])
		p->peer_session_id = rta_getattr_u32(attrs[L2TP_ATTR_PEER_SESSION_ID]);
	if (attrs[L2TP_ATTR_L2SPEC_TYPE])
		p->l2spec_type = rta_getattr_u8(attrs[L2TP_ATTR_L2SPEC_TYPE]);
	if (attrs[L2TP_ATTR_L2SPEC_LEN])
		p->l2spec_len = rta_getattr_u8(attrs[L2TP_ATTR_L2SPEC_LEN]);

	if (attrs[L2TP_ATTR_UDP_CSUM])
		p->udp_csum = !!rta_getattr_u8(attrs[L2TP_ATTR_UDP_CSUM]);

	p->udp6_csum_tx = !attrs[L2TP_ATTR_UDP_ZERO_CSUM6_TX];
	p->udp6_csum_rx = !attrs[L2TP_ATTR_UDP_ZERO_CSUM6_RX];

	if (attrs[L2TP_ATTR_COOKIE])
		memcpy(p->cookie, RTA_DATA(attrs[L2TP_ATTR_COOKIE]),
		       p->cookie_len = RTA_PAYLOAD(attrs[L2TP_ATTR_COOKIE]));

	if (attrs[L2TP_ATTR_PEER_COOKIE])
		memcpy(p->peer_cookie, RTA_DATA(attrs[L2TP_ATTR_PEER_COOKIE]),
		       p->peer_cookie_len = RTA_PAYLOAD(attrs[L2TP_ATTR_PEER_COOKIE]));

	if (attrs[L2TP_ATTR_RECV_SEQ])
		p->recv_seq = !!rta_getattr_u8(attrs[L2TP_ATTR_RECV_SEQ]);
	if (attrs[L2TP_ATTR_SEND_SEQ])
		p->send_seq = !!rta_getattr_u8(attrs[L2TP_ATTR_SEND_SEQ]);

	if (attrs[L2TP_ATTR_RECV_TIMEOUT])
		p->reorder_timeout = rta_getattr_u64(attrs[L2TP_ATTR_RECV_TIMEOUT]);
	if (attrs[L2TP_ATTR_IP_SADDR]) {
		p->local_ip.family = AF_INET;
		p->local_ip.data[0] = rta_getattr_u32(attrs[L2TP_ATTR_IP_SADDR]);
		p->local_ip.bytelen = 4;
		p->local_ip.bitlen = -1;
	}
	if (attrs[L2TP_ATTR_IP_DADDR]) {
		p->peer_ip.family = AF_INET;
		p->peer_ip.data[0] = rta_getattr_u32(attrs[L2TP_ATTR_IP_DADDR]);
		p->peer_ip.bytelen = 4;
		p->peer_ip.bitlen = -1;
	}
	if (attrs[L2TP_ATTR_IP6_SADDR]) {
		p->local_ip.family = AF_INET6;
		memcpy(&p->local_ip.data, RTA_DATA(attrs[L2TP_ATTR_IP6_SADDR]),
			p->local_ip.bytelen = 16);
		p->local_ip.bitlen = -1;
	}
	if (attrs[L2TP_ATTR_IP6_DADDR]) {
		p->peer_ip.family = AF_INET6;
		memcpy(&p->peer_ip.data, RTA_DATA(attrs[L2TP_ATTR_IP6_DADDR]),
			p->peer_ip.bytelen = 16);
		p->peer_ip.bitlen = -1;
	}
	if (attrs[L2TP_ATTR_UDP_SPORT])
		p->local_udp_port = rta_getattr_u16(attrs[L2TP_ATTR_UDP_SPORT]);
	if (attrs[L2TP_ATTR_UDP_DPORT])
		p->peer_udp_port = rta_getattr_u16(attrs[L2TP_ATTR_UDP_DPORT]);
	if (attrs[L2TP_ATTR_MTU])
		p->mtu = rta_getattr_u16(attrs[L2TP_ATTR_MTU]);
	if (attrs[L2TP_ATTR_IFNAME])
		p->ifname = rta_getattr_str(attrs[L2TP_ATTR_IFNAME]);

	nla_stats = attrs[L2TP_ATTR_STATS];
	if (nla_stats) {
		struct rtattr *tb[L2TP_ATTR_STATS_MAX + 1];

		parse_rtattr_nested(tb, L2TP_ATTR_STATS_MAX, nla_stats);
//.........这里部分代码省略.........

int genl_ctrl_resolve_family(const char *family)
{
	struct rtnl_handle rth;
	struct nlmsghdr *nlh;
	struct genlmsghdr *ghdr;
	int ret = 0;
	struct {
		struct nlmsghdr         n;
		char                    buf[4096];
	} req;

	memset(&req, 0, sizeof(req));

	nlh = &req.n;
	nlh->nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
	nlh->nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
	nlh->nlmsg_type = GENL_ID_CTRL;

	ghdr = NLMSG_DATA(&req.n);
	ghdr->cmd = CTRL_CMD_GETFAMILY;

	if (rtnl_open_byproto(&rth, 0, NETLINK_GENERIC) < 0) {
		fprintf(stderr, "Cannot open generic netlink socket\n");
		exit(1);
	}

	addattr_l(nlh, 128, CTRL_ATTR_FAMILY_NAME, family, strlen(family) + 1);

	if (rtnl_talk(&rth, nlh, nlh, sizeof(req)) < 0) {
		fprintf(stderr, "Error talking to the kernel\n");
		goto errout;
	}

	{
		struct rtattr *tb[CTRL_ATTR_MAX + 1];
		struct genlmsghdr *ghdr = NLMSG_DATA(nlh);
		int len = nlh->nlmsg_len;
		struct rtattr *attrs;

		if (nlh->nlmsg_type !=  GENL_ID_CTRL) {
			fprintf(stderr, "Not a controller message, nlmsg_len=%d "
				"nlmsg_type=0x%x\n", nlh->nlmsg_len, nlh->nlmsg_type);
			goto errout;
		}

		if (ghdr->cmd != CTRL_CMD_NEWFAMILY) {
			fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
			goto errout;
		}

		len -= NLMSG_LENGTH(GENL_HDRLEN);

		if (len < 0) {
			fprintf(stderr, "wrong controller message len %d\n", len);
			return -1;
		}

		attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
		parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);

		if (tb[CTRL_ATTR_FAMILY_ID] == NULL) {
			fprintf(stderr, "Missing family id TLV\n");
			goto errout;
		}

		ret = rta_getattr_u16(tb[CTRL_ATTR_FAMILY_ID]);
	}

errout:
	rtnl_close(&rth);
	return ret;
}

static int tc_qdisc_modify(int cmd, unsigned flags, int argc, char **argv)
{
	struct qdisc_util *q = NULL;
	struct tc_estimator est;
	struct {
		struct tc_sizespec	szopts;
		__u16			*data;
	} stab;
	char  d[16];
	char  k[16];
	struct {
		struct nlmsghdr 	n;
		struct tcmsg 		t;
		char   			buf[TCA_BUF_MAX];
	} req;

	memset(&req, 0, sizeof(req));
	memset(&stab, 0, sizeof(stab));
	memset(&est, 0, sizeof(est));
	memset(&d, 0, sizeof(d));
	memset(&k, 0, sizeof(k));

	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct tcmsg));
	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
	req.n.nlmsg_type = cmd;
	req.t.tcm_family = AF_UNSPEC;

	while (argc > 0) {
		if (strcmp(*argv, "dev") == 0) {
			NEXT_ARG();
			if (d[0])
				duparg("dev", *argv);
			strncpy(d, *argv, sizeof(d)-1);
		} else if (strcmp(*argv, "handle") == 0) {
			__u32 handle;
			if (req.t.tcm_handle)
				duparg("handle", *argv);
			NEXT_ARG();
			if (get_qdisc_handle(&handle, *argv))
				invarg("invalid qdisc ID", *argv);
			req.t.tcm_handle = handle;
		} else if (strcmp(*argv, "root") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr, "Error: \"root\" is duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_ROOT;
#ifdef TC_H_INGRESS
		} else if (strcmp(*argv, "ingress") == 0) {
			if (req.t.tcm_parent) {
				fprintf(stderr, "Error: \"ingress\" is a duplicate parent ID\n");
				return -1;
			}
			req.t.tcm_parent = TC_H_INGRESS;
			strncpy(k, "ingress", sizeof(k)-1);
			q = get_qdisc_kind(k);
			req.t.tcm_handle = 0xffff0000;

			argc--; argv++;
			break;
#endif
		} else if (strcmp(*argv, "parent") == 0) {
			__u32 handle;
			NEXT_ARG();
			if (req.t.tcm_parent)
				duparg("parent", *argv);
			if (get_tc_classid(&handle, *argv))
				invarg("invalid parent ID", *argv);
			req.t.tcm_parent = handle;
		} else if (matches(*argv, "estimator") == 0) {
			if (parse_estimator(&argc, &argv, &est))
				return -1;
		} else if (matches(*argv, "stab") == 0) {
			if (parse_size_table(&argc, &argv, &stab.szopts) < 0)
				return -1;
			continue;
		} else if (matches(*argv, "help") == 0) {
			usage();
		} else {
			strncpy(k, *argv, sizeof(k)-1);

			q = get_qdisc_kind(k);
			argc--; argv++;
			break;
		}
		argc--; argv++;
	}

	if (k[0])
		addattr_l(&req.n, sizeof(req), TCA_KIND, k, strlen(k)+1);
	if (est.ewma_log)
		addattr_l(&req.n, sizeof(req), TCA_RATE, &est, sizeof(est));

	if (q) {
		if (q->parse_qopt) {
			if (q->parse_qopt(q, argc, argv, &req.n))
				return 1;
		} else if (argc) {
			fprintf(stderr, "qdisc '%s' does not support option parsing\n", k);
			return -1;
//.........这里部分代码省略.........

static int gre_parse_opt(struct link_util *lu, int argc, char **argv,
			 struct nlmsghdr *n)
{
	struct {
		struct nlmsghdr n;
		struct ifinfomsg i;
		char buf[1024];
	} req;
	struct ifinfomsg *ifi = (struct ifinfomsg *)(n + 1);
	struct rtattr *tb[IFLA_MAX + 1];
	struct rtattr *linkinfo[IFLA_INFO_MAX+1];
	struct rtattr *greinfo[IFLA_GRE_MAX + 1];
	__u16 iflags = 0;
	__u16 oflags = 0;
	unsigned ikey = 0;
	unsigned okey = 0;
	unsigned saddr = 0;
	unsigned daddr = 0;
	unsigned link = 0;
	__u8 pmtudisc = 1;
	__u8 ttl = 0;
	__u8 tos = 0;
	int len;

	if (!(n->nlmsg_flags & NLM_F_CREATE)) {
		memset(&req, 0, sizeof(req));

		req.n.nlmsg_len = NLMSG_LENGTH(sizeof(*ifi));
		req.n.nlmsg_flags = NLM_F_REQUEST;
		req.n.nlmsg_type = RTM_GETLINK;
		req.i.ifi_family = preferred_family;
		req.i.ifi_index = ifi->ifi_index;

		if (rtnl_talk(&rth, &req.n, 0, 0, &req.n, NULL, NULL) < 0) {
get_failed:
			fprintf(stderr,
				"Failed to get existing tunnel info.\n");
			return -1;
		}

		len = req.n.nlmsg_len;
		len -= NLMSG_LENGTH(sizeof(*ifi));
		if (len < 0)
			goto get_failed;

		parse_rtattr(tb, IFLA_MAX, IFLA_RTA(&req.i), len);

		if (!tb[IFLA_LINKINFO])
			goto get_failed;

		parse_rtattr_nested(linkinfo, IFLA_INFO_MAX, tb[IFLA_LINKINFO]);

		if (!linkinfo[IFLA_INFO_DATA])
			goto get_failed;

		parse_rtattr_nested(greinfo, IFLA_GRE_MAX,
				    linkinfo[IFLA_INFO_DATA]);

		if (greinfo[IFLA_GRE_IKEY])
			ikey = *(__u32 *)RTA_DATA(greinfo[IFLA_GRE_IKEY]);

		if (greinfo[IFLA_GRE_OKEY])
			okey = *(__u32 *)RTA_DATA(greinfo[IFLA_GRE_OKEY]);

		if (greinfo[IFLA_GRE_IFLAGS])
			iflags = *(__u16 *)RTA_DATA(greinfo[IFLA_GRE_IFLAGS]);

		if (greinfo[IFLA_GRE_OFLAGS])
			oflags = *(__u16 *)RTA_DATA(greinfo[IFLA_GRE_OFLAGS]);

		if (greinfo[IFLA_GRE_LOCAL])
			saddr = *(__u32 *)RTA_DATA(greinfo[IFLA_GRE_LOCAL]);

		if (greinfo[IFLA_GRE_REMOTE])
			daddr = *(__u32 *)RTA_DATA(greinfo[IFLA_GRE_REMOTE]);

		if (greinfo[IFLA_GRE_PMTUDISC])
			pmtudisc = *(__u8 *)RTA_DATA(
				greinfo[IFLA_GRE_PMTUDISC]);

		if (greinfo[IFLA_GRE_TTL])
			ttl = *(__u8 *)RTA_DATA(greinfo[IFLA_GRE_TTL]);

		if (greinfo[IFLA_GRE_TOS])
			tos = *(__u8 *)RTA_DATA(greinfo[IFLA_GRE_TOS]);

		if (greinfo[IFLA_GRE_LINK])
			link = *(__u8 *)RTA_DATA(greinfo[IFLA_GRE_LINK]);
	}

	while (argc > 0) {
		if (!matches(*argv, "key")) {
			unsigned uval;

			NEXT_ARG();
			iflags |= GRE_KEY;
			oflags |= GRE_KEY;
			if (strchr(*argv, '.'))
				uval = get_addr32(*argv);
			else {
//.........这里部分代码省略.........

/*
 * The controller sends one nlmsg per family
*/
static int print_ctrl(const struct sockaddr_nl *who,
		      struct rtnl_ctrl_data *ctrl,
		      struct nlmsghdr *n, void *arg)
{
	struct rtattr *tb[CTRL_ATTR_MAX + 1];
	struct genlmsghdr *ghdr = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	struct rtattr *attrs;
	FILE *fp = (FILE *) arg;
	__u32 ctrl_v = 0x1;

	if (n->nlmsg_type !=  GENL_ID_CTRL) {
		fprintf(stderr, "Not a controller message, nlmsg_len=%d "
			"nlmsg_type=0x%x\n", n->nlmsg_len, n->nlmsg_type);
		return 0;
	}

	if (ghdr->cmd != CTRL_CMD_GETFAMILY &&
	    ghdr->cmd != CTRL_CMD_DELFAMILY &&
	    ghdr->cmd != CTRL_CMD_NEWFAMILY &&
	    ghdr->cmd != CTRL_CMD_NEWMCAST_GRP &&
	    ghdr->cmd != CTRL_CMD_DELMCAST_GRP) {
		fprintf(stderr, "Unknown controller command %d\n", ghdr->cmd);
		return 0;
	}

	len -= NLMSG_LENGTH(GENL_HDRLEN);

	if (len < 0) {
		fprintf(stderr, "wrong controller message len %d\n", len);
		return -1;
	}

	attrs = (struct rtattr *) ((char *) ghdr + GENL_HDRLEN);
	parse_rtattr(tb, CTRL_ATTR_MAX, attrs, len);

	if (tb[CTRL_ATTR_FAMILY_NAME]) {
		char *name = RTA_DATA(tb[CTRL_ATTR_FAMILY_NAME]);
		fprintf(fp, "\nName: %s\n",name);
	}
	if (tb[CTRL_ATTR_FAMILY_ID]) {
		__u16 *id = RTA_DATA(tb[CTRL_ATTR_FAMILY_ID]);
		fprintf(fp, "\tID: 0x%x ",*id);
	}
	if (tb[CTRL_ATTR_VERSION]) {
		__u32 *v = RTA_DATA(tb[CTRL_ATTR_VERSION]);
		fprintf(fp, " Version: 0x%x ",*v);
		ctrl_v = *v;
	}
	if (tb[CTRL_ATTR_HDRSIZE]) {
		__u32 *h = RTA_DATA(tb[CTRL_ATTR_HDRSIZE]);
		fprintf(fp, " header size: %d ",*h);
	}
	if (tb[CTRL_ATTR_MAXATTR]) {
		__u32 *ma = RTA_DATA(tb[CTRL_ATTR_MAXATTR]);
		fprintf(fp, " max attribs: %d ",*ma);
	}
	/* end of family definitions .. */
	fprintf(fp,"\n");
	if (tb[CTRL_ATTR_OPS]) {
		struct rtattr *tb2[GENL_MAX_FAM_OPS];
		int i=0;
		parse_rtattr_nested(tb2, GENL_MAX_FAM_OPS, tb[CTRL_ATTR_OPS]);
		fprintf(fp, "\tcommands supported: \n");
		for (i = 0; i < GENL_MAX_FAM_OPS; i++) {
			if (tb2[i]) {
				fprintf(fp, "\t\t#%d: ", i);
				if (0 > print_ctrl_cmds(fp, tb2[i], ctrl_v)) {
					fprintf(fp, "Error printing command\n");
				}
				/* for next command */
				fprintf(fp,"\n");
			}
		}

		/* end of family::cmds definitions .. */
		fprintf(fp,"\n");
	}

	if (tb[CTRL_ATTR_MCAST_GROUPS]) {
		struct rtattr *tb2[GENL_MAX_FAM_GRPS + 1];
		int i;

		parse_rtattr_nested(tb2, GENL_MAX_FAM_GRPS,
				    tb[CTRL_ATTR_MCAST_GROUPS]);
		fprintf(fp, "\tmulticast groups:\n");

		for (i = 0; i < GENL_MAX_FAM_GRPS; i++) {
			if (tb2[i]) {
				fprintf(fp, "\t\t#%d: ", i);
				if (0 > print_ctrl_grp(fp, tb2[i], ctrl_v))
					fprintf(fp, "Error printing group\n");
				/* for next group */
				fprintf(fp,"\n");
			}
		}

//.........这里部分代码省略.........

/**
 * In case one binds to 0.0.0.0/INADDR_ANY and wants to know which source
 * address will be used when sending a message this function can be used.
 * It will ask the routing code of the kernel for the PREFSRC
 */
int source_for_dest(const struct in_addr *dest, struct in_addr *loc_source)
{
	int fd, rc;
	struct rtmsg *r;
	struct rtattr *rta;
        struct {
		struct nlmsghdr         n;
		struct rtmsg            r;
		char                    buf[1024];
        } req;

	memset(&req, 0, sizeof(req));

	fd = socket(AF_NETLINK, SOCK_RAW|SOCK_CLOEXEC, NETLINK_ROUTE);
	if (fd < 0) {
		perror("nl socket");
		return -1;
	}

	/* Send a rtmsg and ask for a response */
        req.n.nlmsg_len = NLMSG_LENGTH(sizeof(struct rtmsg));
        req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
        req.n.nlmsg_type = RTM_GETROUTE;
        req.n.nlmsg_seq = 1;

	/* Prepare the routing request */
        req.r.rtm_family = AF_INET;

	/* set the dest */
	rta = NLMSG_TAIL(&req.n);
	rta->rta_type = RTA_DST;
	rta->rta_len = RTA_LENGTH(sizeof(*dest));
	memcpy(RTA_DATA(rta), dest, sizeof(*dest));

	/* update sizes for dest */
	req.r.rtm_dst_len = sizeof(*dest) * 8;
	req.n.nlmsg_len = NLMSG_ALIGN(req.n.nlmsg_len) + RTA_ALIGN(rta->rta_len);

	rc = send(fd, &req, req.n.nlmsg_len, 0);
	if (rc != req.n.nlmsg_len) {
		perror("short write");
		close(fd);
		return -2;
	}


	/* now receive a response and parse it */
	rc = recv(fd, &req, sizeof(req), 0);
	if (rc <= 0) {
		perror("short read");
		close(fd);
		return -3;
	}

	if (!NLMSG_OK(&req.n, rc) || req.n.nlmsg_type != RTM_NEWROUTE) {
		close(fd);
		return -4;
	}

	r = NLMSG_DATA(&req.n);
	rc -= NLMSG_LENGTH(sizeof(*r));
	rta = RTM_RTA(r);
	while (RTA_OK(rta, rc)) {
		if (rta->rta_type != RTA_PREFSRC) {
			rta = RTA_NEXT(rta, rc);
			continue;
		}

		/* we are done */
		memcpy(loc_source, RTA_DATA(rta), RTA_PAYLOAD(rta));
		close(fd);
		return 0;
	}

	close(fd);
	return -5;
}

int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
	FILE *fp = (FILE*)arg;
	struct rtmsg *r = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	struct rtattr * tb[RTA_MAX+1];
	char abuf[256];
	int host_len;
	__u32 table;
	SPRINT_BUF(b1);
	static int hz;

	if (n->nlmsg_type != RTM_NEWROUTE && n->nlmsg_type != RTM_DELROUTE) {
		fprintf(stderr, "Not a route: %08x %08x %08x\n",
			n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
		return 0;
	}
	if (filter.flushb && n->nlmsg_type != RTM_NEWROUTE)
		return 0;
	len -= NLMSG_LENGTH(sizeof(*r));
	if (len < 0) {
		fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
		return -1;
	}

	host_len = af_bit_len(r->rtm_family);

	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
	table = rtm_get_table(r, tb);

	if (!filter_nlmsg(n, tb, host_len))
		return 0;

	if (filter.flushb) {
		struct nlmsghdr *fn;
		if (NLMSG_ALIGN(filter.flushp) + n->nlmsg_len > filter.flushe) {
			if (flush_update())
				return -1;
		}
		fn = (struct nlmsghdr*)(filter.flushb + NLMSG_ALIGN(filter.flushp));
		memcpy(fn, n, n->nlmsg_len);
		fn->nlmsg_type = RTM_DELROUTE;
		fn->nlmsg_flags = NLM_F_REQUEST;
		fn->nlmsg_seq = ++rth.seq;
		filter.flushp = (((char*)fn) + n->nlmsg_len) - filter.flushb;
		filter.flushed++;
		if (show_stats < 2)
			return 0;
	}

	if (n->nlmsg_type == RTM_DELROUTE)
		fprintf(fp, "Deleted ");
	if ((r->rtm_type != RTN_UNICAST || show_details > 0) && !filter.type)
		fprintf(fp, "%s ", rtnl_rtntype_n2a(r->rtm_type, b1, sizeof(b1)));

	if (tb[RTA_DST]) {
		if (r->rtm_dst_len != host_len) {
			fprintf(fp, "%s/%u ", rt_addr_n2a(r->rtm_family,
						       RTA_PAYLOAD(tb[RTA_DST]),
						       RTA_DATA(tb[RTA_DST]),
						       abuf, sizeof(abuf)),
				r->rtm_dst_len
				);
		} else {
			fprintf(fp, "%s ", format_host(r->rtm_family,
						       RTA_PAYLOAD(tb[RTA_DST]),
						       RTA_DATA(tb[RTA_DST]),
						       abuf, sizeof(abuf))
				);
		}
	} else if (r->rtm_dst_len) {
		fprintf(fp, "0/%d ", r->rtm_dst_len);
	} else {
		fprintf(fp, "default ");
	}
	if (tb[RTA_SRC]) {
		if (r->rtm_src_len != host_len) {
			fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
						       RTA_PAYLOAD(tb[RTA_SRC]),
						       RTA_DATA(tb[RTA_SRC]),
						       abuf, sizeof(abuf)),
				r->rtm_src_len
				);
		} else {
			fprintf(fp, "from %s ", format_host(r->rtm_family,
						       RTA_PAYLOAD(tb[RTA_SRC]),
						       RTA_DATA(tb[RTA_SRC]),
						       abuf, sizeof(abuf))
				);
		}
	} else if (r->rtm_src_len) {
		fprintf(fp, "from 0/%u ", r->rtm_src_len);
	}
	if (tb[RTA_NEWDST]) {
		fprintf(fp, "as to %s ", format_host(r->rtm_family,
						  RTA_PAYLOAD(tb[RTA_NEWDST]),
						  RTA_DATA(tb[RTA_NEWDST]),
						  abuf, sizeof(abuf))
			);
	}
//.........这里部分代码省略.........

int
netlink_link_add_vmac(vrrp_t *vrrp)
{
	struct rtattr *linkinfo;
	struct rtattr *data;
	unsigned int base_ifindex;
	interface_t *ifp;
	interface_t *base_ifp;
	char ifname[IFNAMSIZ];
	struct {
		struct nlmsghdr n;
		struct ifinfomsg ifi;
		char buf[256];
	} req;

	if (!vrrp->ifp || __test_bit(VRRP_VMAC_UP_BIT, &vrrp->vmac_flags) || !vrrp->vrid)
		return -1;

	if (vrrp->family == AF_INET6)
		ll_addr[4] = 0x02;
	else
		ll_addr[4] = 0x01;

	ll_addr[ETH_ALEN-1] = vrrp->vrid;

	memset(&req, 0, sizeof (req));
	memset(ifname, 0, IFNAMSIZ);
	strncpy(ifname, vrrp->vmac_ifname, IFNAMSIZ - 1);

	/*
	 * Check to see if this vmac interface was created
	 * by a previous instance.
	 */
	if ((ifp = if_get_by_ifname(ifname))) {
		/* Check to see whether this interface has wrong mac ? */
		if (memcmp((const void *) ifp->hw_addr,
			   (const void *) ll_addr, ETH_ALEN) != 0) {
			/* We have found a VIF but the vmac do not match */
			log_message(LOG_INFO, "vmac: Removing old VMAC interface %s due to conflicting "
					      "interface MAC for vrrp_instance %s!!!"
					    , vrrp->vmac_ifname, vrrp->iname);

			/* Request that NETLINK remove the VIF interface first */
			memset(&req, 0, sizeof (req));
			req.n.nlmsg_len = NLMSG_LENGTH(sizeof (struct ifinfomsg));
			req.n.nlmsg_flags = NLM_F_REQUEST;
			req.n.nlmsg_type = RTM_DELLINK;
			req.ifi.ifi_family = AF_INET;
			req.ifi.ifi_index = IF_INDEX(ifp);

			if (netlink_talk(&nl_cmd, &req.n) < 0) {
				log_message(LOG_INFO, "vmac: Error removing VMAC interface %s for "
						      "vrrp_instance %s!!!"
						    , vrrp->vmac_ifname, vrrp->iname);
				return -1;
			}

			/* Interface successfully removed, now recreate */
		}
	}

	/* Request that NETLINK create the VIF interface */
	req.n.nlmsg_len = NLMSG_LENGTH(sizeof (struct ifinfomsg));
	req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL;
	req.n.nlmsg_type = RTM_NEWLINK;
	req.ifi.ifi_family = AF_INET;

	/* macvlan settings */
	linkinfo = NLMSG_TAIL(&req.n);
	addattr_l(&req.n, sizeof(req), IFLA_LINKINFO, NULL, 0);
	addattr_l(&req.n, sizeof(req), IFLA_INFO_KIND, (void *)macvlan_ll_kind, strlen(macvlan_ll_kind));
	data = NLMSG_TAIL(&req.n);
	addattr_l(&req.n, sizeof(req), IFLA_INFO_DATA, NULL, 0);

	/*
	 * In private mode, macvlan will receive frames with same MAC addr
	 * as configured on the interface.
	 */
	addattr32(&req.n, sizeof(req), IFLA_MACVLAN_MODE,
		  MACVLAN_MODE_PRIVATE);
	data->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)data;
	linkinfo->rta_len = (void *)NLMSG_TAIL(&req.n) - (void *)linkinfo;
	addattr_l(&req.n, sizeof(req), IFLA_LINK, &IF_INDEX(vrrp->ifp), sizeof(uint32_t));
	addattr_l(&req.n, sizeof(req), IFLA_IFNAME, ifname, strlen(ifname));
	addattr_l(&req.n, sizeof(req), IFLA_ADDRESS, ll_addr, ETH_ALEN);

	if (netlink_talk(&nl_cmd, &req.n) < 0) {
		log_message(LOG_INFO, "vmac: Error creating VMAC interface %s for vrrp_instance %s!!!"
				    , ifname, vrrp->iname);
		return -1;
	}

	log_message(LOG_INFO, "vmac: Success creating VMAC interface %s for vrrp_instance %s"
			    , ifname, vrrp->iname);

	/*
	 * Update interface queue and vrrp instance interface binding.
	 */
	netlink_interface_lookup();
	ifp = if_get_by_ifname(ifname);
//.........这里部分代码省略.........

int print_route(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
	FILE *fp = (FILE*)arg;
	struct rtmsg *r = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	struct rtattr * tb[RTA_MAX+1];
	char abuf[256];
	inet_prefix dst;
	inet_prefix src;
	inet_prefix prefsrc;
	inet_prefix via;
	int host_len = -1;
	static int ip6_multiple_tables;
	__u32 table;
	SPRINT_BUF(b1);
	static int hz;

	if (n->nlmsg_type != RTM_NEWROUTE && n->nlmsg_type != RTM_DELROUTE) {
		fprintf(stderr, "Not a route: %08x %08x %08x\n",
			n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
		return 0;
	}
	if (filter.flushb && n->nlmsg_type != RTM_NEWROUTE)
		return 0;
	len -= NLMSG_LENGTH(sizeof(*r));
	if (len < 0) {
		fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
		return -1;
	}

	if (r->rtm_family == AF_INET6)
		host_len = 128;
	else if (r->rtm_family == AF_INET)
		host_len = 32;
	else if (r->rtm_family == AF_DECnet)
		host_len = 16;
	else if (r->rtm_family == AF_IPX)
		host_len = 80;

	parse_rtattr(tb, RTA_MAX, RTM_RTA(r), len);
	table = rtm_get_table(r, tb);

	if (r->rtm_family == AF_INET6 && table != RT_TABLE_MAIN)
		ip6_multiple_tables = 1;

	if (filter.cloned == !(r->rtm_flags&RTM_F_CLONED))
		return 0;

	if (r->rtm_family == AF_INET6 && !ip6_multiple_tables) {
		if (filter.tb) {
			if (filter.tb == RT_TABLE_LOCAL) {
				if (r->rtm_type != RTN_LOCAL)
					return 0;
			} else if (filter.tb == RT_TABLE_MAIN) {
				if (r->rtm_type == RTN_LOCAL)
					return 0;
			} else {
				return 0;
			}
		}
	} else {
		if (filter.tb > 0 && filter.tb != table)
			return 0;
	}
	if ((filter.protocol^r->rtm_protocol)&filter.protocolmask)
		return 0;
	if ((filter.scope^r->rtm_scope)&filter.scopemask)
		return 0;
	if ((filter.type^r->rtm_type)&filter.typemask)
		return 0;
	if ((filter.tos^r->rtm_tos)&filter.tosmask)
		return 0;
	if (filter.rdst.family &&
	    (r->rtm_family != filter.rdst.family || filter.rdst.bitlen > r->rtm_dst_len))
		return 0;
	if (filter.mdst.family &&
	    (r->rtm_family != filter.mdst.family ||
	     (filter.mdst.bitlen >= 0 && filter.mdst.bitlen < r->rtm_dst_len)))
		return 0;
	if (filter.rsrc.family &&
	    (r->rtm_family != filter.rsrc.family || filter.rsrc.bitlen > r->rtm_src_len))
		return 0;
	if (filter.msrc.family &&
	    (r->rtm_family != filter.msrc.family ||
	     (filter.msrc.bitlen >= 0 && filter.msrc.bitlen < r->rtm_src_len)))
		return 0;
	if (filter.rvia.family && r->rtm_family != filter.rvia.family)
		return 0;
	if (filter.rprefsrc.family && r->rtm_family != filter.rprefsrc.family)
		return 0;

	memset(&dst, 0, sizeof(dst));
	dst.family = r->rtm_family;
	if (tb[RTA_DST])
		memcpy(&dst.data, RTA_DATA(tb[RTA_DST]), (r->rtm_dst_len+7)/8);
	if (filter.rsrc.family || filter.msrc.family) {
		memset(&src, 0, sizeof(src));
		src.family = r->rtm_family;
		if (tb[RTA_SRC])
			memcpy(&src.data, RTA_DATA(tb[RTA_SRC]), (r->rtm_src_len+7)/8);
//.........这里部分代码省略.........

static void
format_netlink(struct nlmsghdr *msg)
{
	struct rtattr *tb[ACPI_GENL_ATTR_MAX + 1];
	struct genlmsghdr *ghdr = NLMSG_DATA(msg);
	int len;
	struct rtattr *attrs;
	
	len = msg->nlmsg_len;
	
	/* if this message doesn't have the proper family ID, drop it */
	if (msg->nlmsg_type != acpi_ids_getfamily()) {
		if (logevents) {
			acpid_log(LOG_INFO, "wrong netlink family ID.\n");
		}
		return;
	}

	len -= NLMSG_LENGTH(GENL_HDRLEN);

	if (len < 0) {
		acpid_log(LOG_WARNING,
			"wrong netlink controller message len: %d\n", len);
		return;
	}

	attrs = (struct rtattr *)((char *)ghdr + GENL_HDRLEN);
	/* parse the attributes in this message */
	parse_rtattr(tb, ACPI_GENL_ATTR_MAX, attrs, len);

	/* if there's an ACPI event attribute... */
	if (tb[ACPI_GENL_ATTR_EVENT]) {
		/* get the actual event struct */
		struct acpi_genl_event *event =
				RTA_DATA(tb[ACPI_GENL_ATTR_EVENT]);
		char buf[64];

		/* format it */
		snprintf(buf, sizeof(buf), "%s %s %08x %08x",
			event->device_class, event->bus_id, event->type, event->data);

		/* if we're locked, don't process the event */
		if (locked()) {
			if (logevents) {
				acpid_log(LOG_INFO,
					"lockfile present, not processing "
					"netlink event \"%s\"\n", buf);
			}
			return;
		}

		if (logevents)
			acpid_log(LOG_INFO,
				"received netlink event \"%s\"\n", buf);

		/* send the event off to the handler */
		acpid_handle_event(buf);

		if (logevents)
			acpid_log(LOG_INFO,
				"completed netlink event \"%s\"\n", buf);
	}
}

static void recvaddrs(int fd, struct ifaddrs **ifa, __u32 seq)
{
    char    buf[8192];
    struct sockaddr_nl nladdr;
    struct iovec iov = { buf, sizeof(buf) };
    struct ifaddrmsg *m;
    struct rtattr * rta_tb[IFA_MAX+1];
    struct ifaddrs *I;

    while (1) {
        int status;
        struct nlmsghdr *h;

        struct msghdr msg = {
            (void*)&nladdr, sizeof(nladdr),
            &iov,   1,
            NULL,   0,
            0
        };

        status = recvmsg(fd, &msg, 0);

        if (status < 0)
            continue;

        if (status == 0)
            return;

        if (nladdr.nl_pid) /* Message not from kernel */
            continue;

        h = (struct nlmsghdr*)buf;
        while (NLMSG_OK(h, status)) {
            if (h->nlmsg_seq != seq)
                goto skip_it;

            if (h->nlmsg_type == NLMSG_DONE)
                return;

            if (h->nlmsg_type == NLMSG_ERROR)
                return;

            if (h->nlmsg_type != RTM_NEWADDR)
                goto skip_it;

            m = NLMSG_DATA(h);

            if (m->ifa_family != AF_INET &&
                    m->ifa_family != AF_INET6)
                goto skip_it;

            if (m->ifa_flags&IFA_F_TENTATIVE)
                goto skip_it;

            memset(rta_tb, 0, sizeof(rta_tb));
            parse_rtattr(rta_tb, IFA_MAX, IFA_RTA(m), h->nlmsg_len - NLMSG_LENGTH(sizeof(*m)));

            if (rta_tb[IFA_LOCAL] == NULL)
                rta_tb[IFA_LOCAL] = rta_tb[IFA_ADDRESS];
            if (rta_tb[IFA_LOCAL] == NULL)
                goto skip_it;

            I = malloc(sizeof(struct ifaddrs));
            if (!I)
                return;
            memset(I, 0, sizeof(*I));

            I->ifa_ifindex = m->ifa_index;
            I->ifa_addr = (struct sockaddr*)&I->ifa_addrbuf;
            I->ifa_addr->sa_family = m->ifa_family;
            if (m->ifa_family == AF_INET) {
                struct sockaddr_in *sin = (void*)I->ifa_addr;
                memcpy(&sin->sin_addr, RTA_DATA(rta_tb[IFA_LOCAL]), 4);
            } else {
                struct sockaddr_in6 *sin = (void*)I->ifa_addr;
                memcpy(&sin->sin6_addr, RTA_DATA(rta_tb[IFA_LOCAL]), 16);
                if (IN6_IS_ADDR_LINKLOCAL(&sin->sin6_addr))
                    sin->sin6_scope_id = I->ifa_ifindex;
            }
            I->ifa_next = *ifa;
            *ifa = I;

skip_it:
            h = NLMSG_NEXT(h, status);
        }
        if (msg.msg_flags & MSG_TRUNC)
            continue;
    }
    return;
}

static int xfrm_policy_keep(const struct sockaddr_nl *who,
			    struct nlmsghdr *n,
			    void *arg)
{
	struct xfrm_buffer *xb = (struct xfrm_buffer *)arg;
	struct rtnl_handle *rth = xb->rth;
	struct xfrm_userpolicy_info *xpinfo = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	struct rtattr *tb[XFRMA_MAX+1];
	__u8 ptype = XFRM_POLICY_TYPE_MAIN;
	struct nlmsghdr *new_n;
	struct xfrm_userpolicy_id *xpid;

	if (n->nlmsg_type != XFRM_MSG_NEWPOLICY) {
		fprintf(stderr, "Not a policy: %08x %08x %08x\n",
			n->nlmsg_len, n->nlmsg_type, n->nlmsg_flags);
		return 0;
	}

	len -= NLMSG_LENGTH(sizeof(*xpinfo));
	if (len < 0) {
		fprintf(stderr, "BUG: wrong nlmsg len %d\n", len);
		return -1;
	}

	parse_rtattr(tb, XFRMA_MAX, XFRMP_RTA(xpinfo), len);

	if (tb[XFRMA_POLICY_TYPE]) {
		struct xfrm_userpolicy_type *upt;

		if (RTA_PAYLOAD(tb[XFRMA_POLICY_TYPE]) < sizeof(*upt)) {
			fprintf(stderr, "too short XFRMA_POLICY_TYPE len\n");
			return -1;
		}
		upt = (struct xfrm_userpolicy_type *)RTA_DATA(tb[XFRMA_POLICY_TYPE]);
		ptype = upt->type;
	}

	if (!xfrm_policy_filter_match(xpinfo, ptype))
		return 0;

	if (xb->offset > xb->size) {
		fprintf(stderr, "Policy buffer overflow\n");
		return -1;
	}

	new_n = (struct nlmsghdr *)(xb->buf + xb->offset);
	new_n->nlmsg_len = NLMSG_LENGTH(sizeof(*xpid));
	new_n->nlmsg_flags = NLM_F_REQUEST;
	new_n->nlmsg_type = XFRM_MSG_DELPOLICY;
	new_n->nlmsg_seq = ++rth->seq;

	xpid = NLMSG_DATA(new_n);
	memcpy(&xpid->sel, &xpinfo->sel, sizeof(xpid->sel));
	xpid->dir = xpinfo->dir;
	xpid->index = xpinfo->index;

	xb->offset += new_n->nlmsg_len;
	xb->nlmsg_count ++;

	return 0;
}

static int xfrm_policy_modify(int cmd, unsigned flags, int argc, char **argv)
{
	struct rtnl_handle rth;
	struct {
		struct nlmsghdr			n;
		struct xfrm_userpolicy_info	xpinfo;
		char				buf[RTA_BUF_SIZE];
	} req;
	char *dirp = NULL;
	char *selp = NULL;
	char *ptypep = NULL;
	char *sctxp = NULL;
	struct xfrm_userpolicy_type upt;
	char tmpls_buf[XFRM_TMPLS_BUF_SIZE];
	int tmpls_len = 0;
	struct xfrm_mark mark = {0, 0};
	struct {
		struct xfrm_user_sec_ctx sctx;
		char	str[CTX_BUF_SIZE];
	} ctx;

	memset(&req, 0, sizeof(req));
	memset(&upt, 0, sizeof(upt));
	memset(&tmpls_buf, 0, sizeof(tmpls_buf));
	memset(&ctx, 0, sizeof(ctx));

	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.xpinfo));
	req.n.nlmsg_flags = NLM_F_REQUEST|flags;
	req.n.nlmsg_type = cmd;
	req.xpinfo.sel.family = preferred_family;

	req.xpinfo.lft.soft_byte_limit = XFRM_INF;
	req.xpinfo.lft.hard_byte_limit = XFRM_INF;
	req.xpinfo.lft.soft_packet_limit = XFRM_INF;
	req.xpinfo.lft.hard_packet_limit = XFRM_INF;

	while (argc > 0) {
		if (strcmp(*argv, "dir") == 0) {
			if (dirp)
				duparg("dir", *argv);
			dirp = *argv;

			NEXT_ARG();
			xfrm_policy_dir_parse(&req.xpinfo.dir, &argc, &argv);
		} else if (strcmp(*argv, "ctx") == 0) {
			char *context;

			if (sctxp)
				duparg("ctx", *argv);
			sctxp = *argv;
			NEXT_ARG();
			context = *argv;
			xfrm_sctx_parse((char *)&ctx.str, context, &ctx.sctx);
		} else if (strcmp(*argv, "mark") == 0) {
			xfrm_parse_mark(&mark, &argc, &argv);
		} else if (strcmp(*argv, "index") == 0) {
			NEXT_ARG();
			if (get_u32(&req.xpinfo.index, *argv, 0))
				invarg("\"INDEX\" is invalid", *argv);
		} else if (strcmp(*argv, "ptype") == 0) {
			if (ptypep)
				duparg("ptype", *argv);
			ptypep = *argv;

			NEXT_ARG();
			xfrm_policy_ptype_parse(&upt.type, &argc, &argv);
		} else if (strcmp(*argv, "action") == 0) {
			NEXT_ARG();
			if (strcmp(*argv, "allow") == 0)
				req.xpinfo.action = XFRM_POLICY_ALLOW;
			else if (strcmp(*argv, "block") == 0)
				req.xpinfo.action = XFRM_POLICY_BLOCK;
			else
				invarg("\"action\" value is invalid\n", *argv);
		} else if (strcmp(*argv, "priority") == 0) {
			NEXT_ARG();
			if (get_u32(&req.xpinfo.priority, *argv, 0))
				invarg("\"PRIORITY\" is invalid", *argv);
		} else if (strcmp(*argv, "flag") == 0) {
			NEXT_ARG();
			xfrm_policy_flag_parse(&req.xpinfo.flags, &argc,
					       &argv);
		} else if (strcmp(*argv, "limit") == 0) {
			NEXT_ARG();
			xfrm_lifetime_cfg_parse(&req.xpinfo.lft, &argc, &argv);
		} else if (strcmp(*argv, "tmpl") == 0) {
			struct xfrm_user_tmpl *tmpl;

			if (tmpls_len + sizeof(*tmpl) > sizeof(tmpls_buf)) {
				fprintf(stderr, "Too many tmpls: buffer overflow\n");
				exit(1);
			}
			tmpl = (struct xfrm_user_tmpl *)((char *)tmpls_buf + tmpls_len);

			tmpl->family = preferred_family;
			tmpl->aalgos = (~(__u32)0);
			tmpl->ealgos = (~(__u32)0);
			tmpl->calgos = (~(__u32)0);

			NEXT_ARG();
//.........这里部分代码省略.........

	char *indexp = NULL;
	char *ptypep = NULL;
	char *sctxp = NULL;
	struct xfrm_userpolicy_type upt;
	struct xfrm_mark mark = {0, 0};
	struct {
		struct xfrm_user_sec_ctx sctx;
		char    str[CTX_BUF_SIZE];
	} ctx;


	memset(&req, 0, sizeof(req));
	memset(&upt, 0, sizeof(upt));
	memset(&ctx, 0, sizeof(ctx));

	req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.xpid));
	req.n.nlmsg_flags = NLM_F_REQUEST;
	req.n.nlmsg_type = delete ? XFRM_MSG_DELPOLICY : XFRM_MSG_GETPOLICY;

	while (argc > 0) {
		if (strcmp(*argv, "dir") == 0) {
			if (dirp)
				duparg("dir", *argv);
			dirp = *argv;

			NEXT_ARG();
			xfrm_policy_dir_parse(&req.xpid.dir, &argc, &argv);

		} else if (strcmp(*argv, "ctx") == 0) {
			char *context;

int print_rule(const struct sockaddr_nl *who, struct nlmsghdr *n, void *arg)
{
	FILE *fp = (FILE*)arg;
	struct rtmsg *r = NLMSG_DATA(n);
	int len = n->nlmsg_len;
	int host_len = -1;
	__u32 table;
	struct rtattr * tb[FRA_MAX+1];
	char abuf[256];
	SPRINT_BUF(b1);

	if (n->nlmsg_type != RTM_NEWRULE && n->nlmsg_type != RTM_DELRULE)
		return 0;

	len -= NLMSG_LENGTH(sizeof(*r));
	if (len < 0)
		return -1;

	parse_rtattr(tb, FRA_MAX, RTM_RTA(r), len);

	if (r->rtm_family == AF_INET)
		host_len = 32;
	else if (r->rtm_family == AF_INET6)
		host_len = 128;
	else if (r->rtm_family == AF_DECnet)
		host_len = 16;
	else if (r->rtm_family == AF_IPX)
		host_len = 80;

	if (n->nlmsg_type == RTM_DELRULE)
		fprintf(fp, "Deleted ");

	if (tb[FRA_PRIORITY])
		fprintf(fp, "%u:\t", *(unsigned*)RTA_DATA(tb[FRA_PRIORITY]));
	else
		fprintf(fp, "0:\t");

	if (r->rtm_flags & FIB_RULE_INVERT)
		fprintf(fp, "not ");

	if (tb[FRA_SRC]) {
		if (r->rtm_src_len != host_len) {
			fprintf(fp, "from %s/%u ", rt_addr_n2a(r->rtm_family,
							 RTA_PAYLOAD(tb[FRA_SRC]),
							 RTA_DATA(tb[FRA_SRC]),
							 abuf, sizeof(abuf)),
				r->rtm_src_len
				);
		} else {
			fprintf(fp, "from %s ", format_host(r->rtm_family,
						       RTA_PAYLOAD(tb[FRA_SRC]),
						       RTA_DATA(tb[FRA_SRC]),
						       abuf, sizeof(abuf))
				);
		}
	} else if (r->rtm_src_len) {
		fprintf(fp, "from 0/%d ", r->rtm_src_len);
	} else {
		fprintf(fp, "from all ");
	}

	if (tb[FRA_DST]) {
		if (r->rtm_dst_len != host_len) {
			fprintf(fp, "to %s/%u ", rt_addr_n2a(r->rtm_family,
							 RTA_PAYLOAD(tb[FRA_DST]),
							 RTA_DATA(tb[FRA_DST]),
							 abuf, sizeof(abuf)),
				r->rtm_dst_len
				);
		} else {
			fprintf(fp, "to %s ", format_host(r->rtm_family,
						       RTA_PAYLOAD(tb[FRA_DST]),
						       RTA_DATA(tb[FRA_DST]),
						       abuf, sizeof(abuf)));
		}
	} else if (r->rtm_dst_len) {
		fprintf(fp, "to 0/%d ", r->rtm_dst_len);
	}

	if (r->rtm_tos) {
		SPRINT_BUF(b1);
		fprintf(fp, "tos %s ", rtnl_dsfield_n2a(r->rtm_tos, b1, sizeof(b1)));
	}

 	if (tb[FRA_FWMARK] || tb[FRA_FWMASK]) {
		__u32 mark = 0, mask = 0;

		if (tb[FRA_FWMARK])
			mark = rta_getattr_u32(tb[FRA_FWMARK]);

		if (tb[FRA_FWMASK] &&
		    (mask = rta_getattr_u32(tb[FRA_FWMASK])) != 0xFFFFFFFF)
			fprintf(fp, "fwmark 0x%x/0x%x ", mark, mask);
		else
			fprintf(fp, "fwmark 0x%x ", mark);
	}

	if (tb[FRA_IFNAME]) {
		fprintf(fp, "iif %s ", rta_getattr_str(tb[FRA_IFNAME]));
		if (r->rtm_flags & FIB_RULE_IIF_DETACHED)
//.........这里部分代码省略.........

/*
 * Adds or deletes an IP address on an interface.
 *
 * Action is one of:
 * - RTM_NEWADDR (to add a new address)
 * - RTM_DELADDR (to delete an existing address)
 *
 * Returns zero on success and negative errno on failure.
 */
int ifc_act_on_address(int action, const char *name, const char *address,
                       int prefixlen) {
    int ifindex, s, len, ret;
    struct sockaddr_storage ss;
    void *addr;
    size_t addrlen;
    struct {
        struct nlmsghdr n;
        struct ifaddrmsg r;
        // Allow for IPv6 address, headers, and padding.
        char attrbuf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
                     NLMSG_ALIGN(sizeof(struct rtattr)) +
                     NLMSG_ALIGN(INET6_ADDRLEN)];
    } req;
    struct rtattr *rta;
    struct nlmsghdr *nh;
    struct nlmsgerr *err;
    char buf[NLMSG_ALIGN(sizeof(struct nlmsghdr)) +
             NLMSG_ALIGN(sizeof(struct nlmsgerr)) +
             NLMSG_ALIGN(sizeof(struct nlmsghdr))];

    // Get interface ID.
    ifindex = if_nametoindex(name);
    if (ifindex == 0) {
        return -errno;
    }

    // Convert string representation to sockaddr_storage.
    ret = string_to_ip(address, &ss);
    if (ret) {
        return ret;
    }

    // Determine address type and length.
    if (ss.ss_family == AF_INET) {
        struct sockaddr_in *sin = (struct sockaddr_in *) &ss;
        addr = &sin->sin_addr;
        addrlen = INET_ADDRLEN;
    } else if (ss.ss_family == AF_INET6) {
        struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *) &ss;
        addr = &sin6->sin6_addr;
        addrlen = INET6_ADDRLEN;
    } else {
        return -EAFNOSUPPORT;
    }

    // Fill in netlink structures.
    memset(&req, 0, sizeof(req));

    // Netlink message header.
    req.n.nlmsg_len = NLMSG_LENGTH(sizeof(req.r));
    req.n.nlmsg_type = action;
    req.n.nlmsg_flags = NLM_F_REQUEST | NLM_F_ACK;
    req.n.nlmsg_pid = getpid();

    // Interface address message header.
    req.r.ifa_family = ss.ss_family;
    req.r.ifa_prefixlen = prefixlen;
    req.r.ifa_index = ifindex;

    // Routing attribute. Contains the actual IP address.
    rta = (struct rtattr *) (((char *) &req) + NLMSG_ALIGN(req.n.nlmsg_len));
    rta->rta_type = IFA_LOCAL;
    rta->rta_len = RTA_LENGTH(addrlen);
    req.n.nlmsg_len = NLMSG_ALIGN(req.n.nlmsg_len) + RTA_LENGTH(addrlen);
    memcpy(RTA_DATA(rta), addr, addrlen);

    s = socket(PF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
    if (send(s, &req, req.n.nlmsg_len, 0) < 0) {
        close(s);
        return -errno;
    }

    len = recv(s, buf, sizeof(buf), 0);
    close(s);
    if (len < 0) {
        return -errno;
    }

    // Parse the acknowledgement to find the return code.
    nh = (struct nlmsghdr *) buf;
    if (!NLMSG_OK(nh, (unsigned) len) || nh->nlmsg_type != NLMSG_ERROR) {
        return -EINVAL;
    }
    err = NLMSG_DATA(nh);

    // Return code is negative errno.
    return err->error;
}