[mirror_iproute2.git] / lib / libnetlink.c

/*
 * libnetlink.c	RTnetlink service routines.
 *
 *		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:	Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <fcntl.h>
#include <net/if_arp.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <string.h>
#include <errno.h>
#include <time.h>
#include <sys/uio.h>

#include "libnetlink.h"

void rtnl_close(struct rtnl_handle *rth)
{
	if (rth->fd >= 0) {
		close(rth->fd);
		rth->fd = -1;
	}
}

int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
		      int protocol)
{
	socklen_t addr_len;
	int sndbuf = 32768;
	int rcvbuf = 32768;

	memset(rth, 0, sizeof(*rth));

	rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
	if (rth->fd < 0) {
		perror("Cannot open netlink socket");
		return -1;
	}

	if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) {
		perror("SO_SNDBUF");
		return -1;
	}

	if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) {
		perror("SO_RCVBUF");
		return -1;
	}

	memset(&rth->local, 0, sizeof(rth->local));
	rth->local.nl_family = AF_NETLINK;
	rth->local.nl_groups = subscriptions;

	if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
		perror("Cannot bind netlink socket");
		return -1;
	}
	addr_len = sizeof(rth->local);
	if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
		perror("Cannot getsockname");
		return -1;
	}
	if (addr_len != sizeof(rth->local)) {
		fprintf(stderr, "Wrong address length %d\n", addr_len);
		return -1;
	}
	if (rth->local.nl_family != AF_NETLINK) {
		fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
		return -1;
	}
	rth->seq = time(NULL);
	return 0;
}

int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
{
	return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
}

int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
{
	struct {
		struct nlmsghdr nlh;
		struct rtgenmsg g;
	} req;

	memset(&req, 0, sizeof(req));
	req.nlh.nlmsg_len = sizeof(req);
	req.nlh.nlmsg_type = type;
	req.nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
	req.nlh.nlmsg_pid = 0;
	req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
	req.g.rtgen_family = family;

	return send(rth->fd, (void*)&req, sizeof(req), 0);
}

int rtnl_send(struct rtnl_handle *rth, const char *buf, int len)
{
	return send(rth->fd, buf, len, 0);
}

int rtnl_send_check(struct rtnl_handle *rth, const char *buf, int len)
{
	struct nlmsghdr *h;
	int status;
	char resp[1024];

	status = send(rth->fd, buf, len, 0);
	if (status < 0)
		return status;

	/* Check for immediate errors */
	status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT|MSG_PEEK);
	if (status < 0) {
		if (errno == EAGAIN)
			return 0;
		return -1;
	}

	for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
	     h = NLMSG_NEXT(h, status)) {
		if (h->nlmsg_type == NLMSG_ERROR) {
			struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
			if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
				fprintf(stderr, "ERROR truncated\n");
			else 
				errno = -err->error;
		}
		return -1;
	}

	return 0;
}

int rtnl_dump_request(struct rtnl_handle *rth, int type, void *req, int len)
{
	struct nlmsghdr nlh;
	struct sockaddr_nl nladdr;
	struct iovec iov[2] = {
		{ .iov_base = &nlh, .iov_len = sizeof(nlh) },
		{ .iov_base = req, .iov_len = len }
	};
	struct msghdr msg = {
		.msg_name = &nladdr,
		.msg_namelen = 	sizeof(nladdr),
		.msg_iov = iov,
		.msg_iovlen = 2,
	};

	memset(&nladdr, 0, sizeof(nladdr));
	nladdr.nl_family = AF_NETLINK;

	nlh.nlmsg_len = NLMSG_LENGTH(len);
	nlh.nlmsg_type = type;
	nlh.nlmsg_flags = NLM_F_ROOT|NLM_F_MATCH|NLM_F_REQUEST;
	nlh.nlmsg_pid = 0;
	nlh.nlmsg_seq = rth->dump = ++rth->seq;

	return sendmsg(rth->fd, &msg, 0);
}

int rtnl_dump_filter(struct rtnl_handle *rth,
		     rtnl_filter_t filter,
		     void *arg1,
		     rtnl_filter_t junk,
		     void *arg2)
{
	struct sockaddr_nl nladdr;
	struct iovec iov;
	struct msghdr msg = {
		.msg_name = &nladdr,
		.msg_namelen = sizeof(nladdr),
		.msg_iov = &iov,
		.msg_iovlen = 1,
	};
	char buf[16384];

	iov.iov_base = buf;
	while (1) {
		int status;
		struct nlmsghdr *h;

		iov.iov_len = sizeof(buf);
		status = recvmsg(rth->fd, &msg, 0);

		if (status < 0) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			fprintf(stderr, "netlink receive error %s (%d)\n",
				strerror(errno), errno);
			return -1;
		}

		if (status == 0) {
			fprintf(stderr, "EOF on netlink\n");
			return -1;
		}

		h = (struct nlmsghdr*)buf;
		while (NLMSG_OK(h, status)) {
			int err;

			if (nladdr.nl_pid != 0 ||
			    h->nlmsg_pid != rth->local.nl_pid ||
			    h->nlmsg_seq != rth->dump) {
				if (junk) {
					err = junk(&nladdr, h, arg2);
					if (err < 0)
						return err;
				}
				goto skip_it;
			}

			if (h->nlmsg_type == NLMSG_DONE)
				return 0;
			if (h->nlmsg_type == NLMSG_ERROR) {
				struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
				if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
					fprintf(stderr, "ERROR truncated\n");
				} else {
					errno = -err->error;
					perror("RTNETLINK answers");
				}
				return -1;
			}
			err = filter(&nladdr, h, arg1);
			if (err < 0)
				return err;

skip_it:
			h = NLMSG_NEXT(h, status);
		}
		if (msg.msg_flags & MSG_TRUNC) {
			fprintf(stderr, "Message truncated\n");
			continue;
		}
		if (status) {
			fprintf(stderr, "!!!Remnant of size %d\n", status);
			exit(1);
		}
	}
}

int rtnl_talk(struct rtnl_handle *rtnl, struct nlmsghdr *n, pid_t peer,
	      unsigned groups, struct nlmsghdr *answer,
	      rtnl_filter_t junk,
	      void *jarg)
{
	int status;
	unsigned seq;
	struct nlmsghdr *h;
	struct sockaddr_nl nladdr;
	struct iovec iov = {
		.iov_base = (void*) n,
		.iov_len = n->nlmsg_len
	};
	struct msghdr msg = {
		.msg_name = &nladdr,
		.msg_namelen = sizeof(nladdr),
		.msg_iov = &iov,
		.msg_iovlen = 1,
	};
	char   buf[16384];

	memset(&nladdr, 0, sizeof(nladdr));
	nladdr.nl_family = AF_NETLINK;
	nladdr.nl_pid = peer;
	nladdr.nl_groups = groups;

	n->nlmsg_seq = seq = ++rtnl->seq;

	if (answer == NULL)
		n->nlmsg_flags |= NLM_F_ACK;

	status = sendmsg(rtnl->fd, &msg, 0);

	if (status < 0) {
		perror("Cannot talk to rtnetlink");
		return -1;
	}

	memset(buf,0,sizeof(buf));

	iov.iov_base = buf;

	while (1) {
		iov.iov_len = sizeof(buf);
		status = recvmsg(rtnl->fd, &msg, 0);

		if (status < 0) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			fprintf(stderr, "netlink receive error %s (%d)\n",
				strerror(errno), errno);
			return -1;
		}
		if (status == 0) {
			fprintf(stderr, "EOF on netlink\n");
			return -1;
		}
		if (msg.msg_namelen != sizeof(nladdr)) {
			fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
			exit(1);
		}
		for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
			int err;
			int len = h->nlmsg_len;
			int l = len - sizeof(*h);

			if (l<0 || len>status) {
				if (msg.msg_flags & MSG_TRUNC) {
					fprintf(stderr, "Truncated message\n");
					return -1;
				}
				fprintf(stderr, "!!!malformed message: len=%d\n", len);
				exit(1);
			}

			if (nladdr.nl_pid != peer ||
			    h->nlmsg_pid != rtnl->local.nl_pid ||
			    h->nlmsg_seq != seq) {
				if (junk) {
					err = junk(&nladdr, h, jarg);
					if (err < 0)
						return err;
				}
				/* Don't forget to skip that message. */
				status -= NLMSG_ALIGN(len);
				h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
				continue;
			}

			if (h->nlmsg_type == NLMSG_ERROR) {
				struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(h);
				if (l < sizeof(struct nlmsgerr)) {
					fprintf(stderr, "ERROR truncated\n");
				} else {
					errno = -err->error;
					if (errno == 0) {
						if (answer)
							memcpy(answer, h, h->nlmsg_len);
						return 0;
					}
					perror("RTNETLINK answers");
				}
				return -1;
			}
			if (answer) {
				memcpy(answer, h, h->nlmsg_len);
				return 0;
			}

			fprintf(stderr, "Unexpected reply!!!\n");

			status -= NLMSG_ALIGN(len);
			h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
		}
		if (msg.msg_flags & MSG_TRUNC) {
			fprintf(stderr, "Message truncated\n");
			continue;
		}
		if (status) {
			fprintf(stderr, "!!!Remnant of size %d\n", status);
			exit(1);
		}
	}
}

int rtnl_listen(struct rtnl_handle *rtnl,
		rtnl_filter_t handler,
		void *jarg)
{
	int status;
	struct nlmsghdr *h;
	struct sockaddr_nl nladdr;
	struct iovec iov;
	struct msghdr msg = {
		.msg_name = &nladdr,
		.msg_namelen = sizeof(nladdr),
		.msg_iov = &iov,
		.msg_iovlen = 1,
	};
	char   buf[8192];

	memset(&nladdr, 0, sizeof(nladdr));
	nladdr.nl_family = AF_NETLINK;
	nladdr.nl_pid = 0;
	nladdr.nl_groups = 0;

	iov.iov_base = buf;
	while (1) {
		iov.iov_len = sizeof(buf);
		status = recvmsg(rtnl->fd, &msg, 0);

		if (status < 0) {
			if (errno == EINTR || errno == EAGAIN)
				continue;
			fprintf(stderr, "netlink receive error %s (%d)\n",
				strerror(errno), errno);
			return -1;
		}
		if (status == 0) {
			fprintf(stderr, "EOF on netlink\n");
			return -1;
		}
		if (msg.msg_namelen != sizeof(nladdr)) {
			fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
			exit(1);
		}
		for (h = (struct nlmsghdr*)buf; status >= sizeof(*h); ) {
			int err;
			int len = h->nlmsg_len;
			int l = len - sizeof(*h);

			if (l<0 || len>status) {
				if (msg.msg_flags & MSG_TRUNC) {
					fprintf(stderr, "Truncated message\n");
					return -1;
				}
				fprintf(stderr, "!!!malformed message: len=%d\n", len);
				exit(1);
			}

			err = handler(&nladdr, h, jarg);
			if (err < 0)
				return err;

			status -= NLMSG_ALIGN(len);
			h = (struct nlmsghdr*)((char*)h + NLMSG_ALIGN(len));
		}
		if (msg.msg_flags & MSG_TRUNC) {
			fprintf(stderr, "Message truncated\n");
			continue;
		}
		if (status) {
			fprintf(stderr, "!!!Remnant of size %d\n", status);
			exit(1);
		}
	}
}

int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
		   void *jarg)
{
	int status;
	struct sockaddr_nl nladdr;
	char   buf[8192];
	struct nlmsghdr *h = (void*)buf;

	memset(&nladdr, 0, sizeof(nladdr));
	nladdr.nl_family = AF_NETLINK;
	nladdr.nl_pid = 0;
	nladdr.nl_groups = 0;

	while (1) {
		int err, len, type;
		int l;

		status = fread(&buf, 1, sizeof(*h), rtnl);

		if (status < 0) {
			if (errno == EINTR)
				continue;
			perror("rtnl_from_file: fread");
			return -1;
		}
		if (status == 0)
			return 0;

		len = h->nlmsg_len;
		type= h->nlmsg_type;
		l = len - sizeof(*h);

		if (l<0 || len>sizeof(buf)) {
			fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
				len, ftell(rtnl));
			return -1;
		}

		status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);

		if (status < 0) {
			perror("rtnl_from_file: fread");
			return -1;
		}
		if (status < l) {
			fprintf(stderr, "rtnl-from_file: truncated message\n");
			return -1;
		}

		err = handler(&nladdr, h, jarg);
		if (err < 0)
			return err;
	}
}

int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
{
	int len = RTA_LENGTH(4);
	struct rtattr *rta;
	if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
		fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
		return -1;
	}
	rta = NLMSG_TAIL(n);
	rta->rta_type = type;
	rta->rta_len = len;
	memcpy(RTA_DATA(rta), &data, 4);
	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
	return 0;
}

int addattr_l(struct nlmsghdr *n, int maxlen, int type, const void *data,
	      int alen)
{
	int len = RTA_LENGTH(alen);
	struct rtattr *rta;

	if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
		fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
		return -1;
	}
	rta = NLMSG_TAIL(n);
	rta->rta_type = type;
	rta->rta_len = len;
	memcpy(RTA_DATA(rta), data, alen);
	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
	return 0;
}

int addraw_l(struct nlmsghdr *n, int maxlen, const void *data, int len)
{
	if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
		fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
		return -1;
	}

	memcpy(NLMSG_TAIL(n), data, len);
	memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
	return 0;
}

struct rtattr *addattr_nest(struct nlmsghdr *n, int maxlen, int type)
{
	struct rtattr *nest = NLMSG_TAIL(n);

	addattr_l(n, maxlen, type, NULL, 0);
	return nest;
}

int addattr_nest_end(struct nlmsghdr *n, struct rtattr *nest)
{
	nest->rta_len = (void *)NLMSG_TAIL(n) - (void *)nest;
	return n->nlmsg_len;
}

struct rtattr *addattr_nest_compat(struct nlmsghdr *n, int maxlen, int type,
				   const void *data, int len)
{
	struct rtattr *start = NLMSG_TAIL(n);

	addattr_l(n, maxlen, type, data, len);
	addattr_nest(n, maxlen, type);
	return start;
}

int addattr_nest_compat_end(struct nlmsghdr *n, struct rtattr *start)
{
	struct rtattr *nest = (void *)start + NLMSG_ALIGN(start->rta_len);

	start->rta_len = (void *)NLMSG_TAIL(n) - (void *)start;
	addattr_nest_end(n, nest);
	return n->nlmsg_len;
}

int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
{
	int len = RTA_LENGTH(4);
	struct rtattr *subrta;

	if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
		fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
		return -1;
	}
	subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
	subrta->rta_type = type;
	subrta->rta_len = len;
	memcpy(RTA_DATA(subrta), &data, 4);
	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
	return 0;
}

int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
		  const void *data, int alen)
{
	struct rtattr *subrta;
	int len = RTA_LENGTH(alen);

	if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
		fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
		return -1;
	}
	subrta = (struct rtattr*)(((char*)rta) + RTA_ALIGN(rta->rta_len));
	subrta->rta_type = type;
	subrta->rta_len = len;
	memcpy(RTA_DATA(subrta), data, alen);
	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
	return 0;
}

int parse_rtattr(struct rtattr *tb[], int max, struct rtattr *rta, int len)
{
	memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
	while (RTA_OK(rta, len)) {
		if (rta->rta_type <= max)
			tb[rta->rta_type] = rta;
		rta = RTA_NEXT(rta,len);
	}
	if (len)
		fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
	return 0;
}

int parse_rtattr_byindex(struct rtattr *tb[], int max, struct rtattr *rta, int len)
{
	int i = 0;

	memset(tb, 0, sizeof(struct rtattr *) * max);
	while (RTA_OK(rta, len)) {
		if (rta->rta_type <= max && i < max)
			tb[i++] = rta;
		rta = RTA_NEXT(rta,len);
	}
	if (len)
		fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
	return i;
}

int __parse_rtattr_nested_compat(struct rtattr *tb[], int max, struct rtattr *rta,
			         int len)
{
	if (RTA_PAYLOAD(rta) < len)
		return -1;
	if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
		rta = RTA_DATA(rta) + RTA_ALIGN(len);
		return parse_rtattr_nested(tb, max, rta);
	}
	memset(tb, 0, sizeof(struct rtattr *) * (max + 1));
	return 0;
}
Commit	Line	Data
aba5acdf SH	1	/*
	2	* libnetlink.c RTnetlink service routines.
	3	*
	4	* This program is free software; you can redistribute it and/or
	5	* modify it under the terms of the GNU General Public License
	6	* as published by the Free Software Foundation; either version
	7	* 2 of the License, or (at your option) any later version.
	8	*
	9	* Authors: Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
	10	*
	11	*/
	12
	13	#include <stdio.h>
	14	#include <stdlib.h>
	15	#include <unistd.h>
	16	#include <syslog.h>
	17	#include <fcntl.h>
	18	#include <net/if_arp.h>
	19	#include <sys/socket.h>
	20	#include <netinet/in.h>
	21	#include <string.h>
	22	#include <errno.h>
	23	#include <time.h>
	24	#include <sys/uio.h>
	25
	26	#include "libnetlink.h"
	27
	28	void rtnl_close(struct rtnl_handle *rth)
	29	{
3bfa73ff SH	30	if (rth->fd >= 0) {
	31	close(rth->fd);
	32	rth->fd = -1;
	33	}
aba5acdf SH	34	}
aba5acdf SH	35
8ed63ab1 SH	36	int rtnl_open_byproto(struct rtnl_handle *rth, unsigned subscriptions,
8ed63ab1 SH	37	int protocol)
aba5acdf	38	{
f332d169	39	socklen_t addr_len;
007d3a3e SH	40	int sndbuf = 32768;
007d3a3e SH	41	int rcvbuf = 32768;
aba5acdf	42
b16621ca	43	memset(rth, 0, sizeof(*rth));
aba5acdf	44
c7699875	45	rth->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
aba5acdf SH	46	if (rth->fd < 0) {
	47	perror("Cannot open netlink socket");
	48	return -1;
	49	}
	50
007d3a3e SH	51	if (setsockopt(rth->fd,SOL_SOCKET,SO_SNDBUF,&sndbuf,sizeof(sndbuf)) < 0) {
	52	perror("SO_SNDBUF");
	53	return -1;
	54	}
	55
	56	if (setsockopt(rth->fd,SOL_SOCKET,SO_RCVBUF,&rcvbuf,sizeof(rcvbuf)) < 0) {
	57	perror("SO_RCVBUF");
	58	return -1;
	59	}
	60
aba5acdf SH	61	memset(&rth->local, 0, sizeof(rth->local));
	62	rth->local.nl_family = AF_NETLINK;
	63	rth->local.nl_groups = subscriptions;
	64
	65	if (bind(rth->fd, (struct sockaddr*)&rth->local, sizeof(rth->local)) < 0) {
	66	perror("Cannot bind netlink socket");
	67	return -1;
	68	}
	69	addr_len = sizeof(rth->local);
	70	if (getsockname(rth->fd, (struct sockaddr*)&rth->local, &addr_len) < 0) {
	71	perror("Cannot getsockname");
	72	return -1;
	73	}
	74	if (addr_len != sizeof(rth->local)) {
	75	fprintf(stderr, "Wrong address length %d\n", addr_len);
	76	return -1;
	77	}
	78	if (rth->local.nl_family != AF_NETLINK) {
	79	fprintf(stderr, "Wrong address family %d\n", rth->local.nl_family);
	80	return -1;
	81	}
	82	rth->seq = time(NULL);
	83	return 0;
	84	}
	85
c7699875	86	int rtnl_open(struct rtnl_handle *rth, unsigned subscriptions)
	87	{
	88	return rtnl_open_byproto(rth, subscriptions, NETLINK_ROUTE);
	89	}
	90
aba5acdf SH	91	int rtnl_wilddump_request(struct rtnl_handle *rth, int family, int type)
	92	{
	93	struct {
	94	struct nlmsghdr nlh;
	95	struct rtgenmsg g;
	96	} req;
aba5acdf	97
8ed63ab1	98	memset(&req, 0, sizeof(req));
aba5acdf SH	99	req.nlh.nlmsg_len = sizeof(req);
	100	req.nlh.nlmsg_type = type;
	101	req.nlh.nlmsg_flags = NLM_F_ROOT\|NLM_F_MATCH\|NLM_F_REQUEST;
	102	req.nlh.nlmsg_pid = 0;
	103	req.nlh.nlmsg_seq = rth->dump = ++rth->seq;
	104	req.g.rtgen_family = family;
	105
f31a37f7	106	return send(rth->fd, (void*)&req, sizeof(req), 0);
aba5acdf SH	107	}
aba5acdf SH	108
6dc9f016	109	int rtnl_send(struct rtnl_handle rth, const char buf, int len)
aba5acdf	110	{
f31a37f7 SH	111	return send(rth->fd, buf, len, 0);
	112	}
	113
	114	int rtnl_send_check(struct rtnl_handle rth, const char buf, int len)
	115	{
54bb35c6 SH	116	struct nlmsghdr *h;
	117	int status;
	118	char resp[1024];
aba5acdf	119
f31a37f7	120	status = send(rth->fd, buf, len, 0);
54bb35c6 SH	121	if (status < 0)
	122	return status;
	123
2d8240f8 SH	124	/* Check for immediate errors */
2d8240f8 SH	125	status = recv(rth->fd, resp, sizeof(resp), MSG_DONTWAIT\|MSG_PEEK);
54bb35c6 SH	126	if (status < 0) {
	127	if (errno == EAGAIN)
	128	return 0;
	129	return -1;
	130	}
	131
	132	for (h = (struct nlmsghdr *)resp; NLMSG_OK(h, status);
	133	h = NLMSG_NEXT(h, status)) {
	134	if (h->nlmsg_type == NLMSG_ERROR) {
	135	struct nlmsgerr err = (struct nlmsgerr)NLMSG_DATA(h);
	136	if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr)))
	137	fprintf(stderr, "ERROR truncated\n");
	138	else
	139	errno = -err->error;
	140	}
	141	return -1;
	142	}
	143
	144	return 0;
aba5acdf SH	145	}
	146
	147	int rtnl_dump_request(struct rtnl_handle rth, int type, void req, int len)
	148	{
	149	struct nlmsghdr nlh;
	150	struct sockaddr_nl nladdr;
8ed63ab1 SH	151	struct iovec iov[2] = {
	152	{ .iov_base = &nlh, .iov_len = sizeof(nlh) },
	153	{ .iov_base = req, .iov_len = len }
	154	};
aba5acdf	155	struct msghdr msg = {
8ed63ab1 SH	156	.msg_name = &nladdr,
	157	.msg_namelen = sizeof(nladdr),
	158	.msg_iov = iov,
	159	.msg_iovlen = 2,
aba5acdf SH	160	};
	161
	162	memset(&nladdr, 0, sizeof(nladdr));
	163	nladdr.nl_family = AF_NETLINK;
	164
	165	nlh.nlmsg_len = NLMSG_LENGTH(len);
	166	nlh.nlmsg_type = type;
	167	nlh.nlmsg_flags = NLM_F_ROOT\|NLM_F_MATCH\|NLM_F_REQUEST;
	168	nlh.nlmsg_pid = 0;
	169	nlh.nlmsg_seq = rth->dump = ++rth->seq;
	170
	171	return sendmsg(rth->fd, &msg, 0);
	172	}
	173
	174	int rtnl_dump_filter(struct rtnl_handle *rth,
6dc9f016	175	rtnl_filter_t filter,
aba5acdf	176	void *arg1,
6dc9f016	177	rtnl_filter_t junk,
aba5acdf SH	178	void *arg2)
aba5acdf SH	179	{
aba5acdf	180	struct sockaddr_nl nladdr;
8ed63ab1 SH	181	struct iovec iov;
	182	struct msghdr msg = {
	183	.msg_name = &nladdr,
	184	.msg_namelen = sizeof(nladdr),
	185	.msg_iov = &iov,
	186	.msg_iovlen = 1,
	187	};
	188	char buf[16384];
aba5acdf	189
8ed63ab1	190	iov.iov_base = buf;
aba5acdf SH	191	while (1) {
	192	int status;
	193	struct nlmsghdr *h;
	194
8ed63ab1	195	iov.iov_len = sizeof(buf);
aba5acdf SH	196	status = recvmsg(rth->fd, &msg, 0);
	197
	198	if (status < 0) {
aa8032e6	199	if (errno == EINTR \|\| errno == EAGAIN)
aba5acdf	200	continue;
aa8032e6 SH	201	fprintf(stderr, "netlink receive error %s (%d)\n",
	202	strerror(errno), errno);
	203	return -1;
aba5acdf	204	}
8ed63ab1	205
aba5acdf SH	206	if (status == 0) {
	207	fprintf(stderr, "EOF on netlink\n");
	208	return -1;
	209	}
aba5acdf SH	210
	211	h = (struct nlmsghdr*)buf;
	212	while (NLMSG_OK(h, status)) {
	213	int err;
	214
10f57ef1	215	if (nladdr.nl_pid != 0 \|\|
10f57ef1	216	h->nlmsg_pid != rth->local.nl_pid \|\|
aba5acdf SH	217	h->nlmsg_seq != rth->dump) {
	218	if (junk) {
	219	err = junk(&nladdr, h, arg2);
	220	if (err < 0)
	221	return err;
	222	}
	223	goto skip_it;
	224	}
	225
	226	if (h->nlmsg_type == NLMSG_DONE)
	227	return 0;
	228	if (h->nlmsg_type == NLMSG_ERROR) {
	229	struct nlmsgerr err = (struct nlmsgerr)NLMSG_DATA(h);
	230	if (h->nlmsg_len < NLMSG_LENGTH(sizeof(struct nlmsgerr))) {
	231	fprintf(stderr, "ERROR truncated\n");
	232	} else {
	233	errno = -err->error;
	234	perror("RTNETLINK answers");
	235	}
	236	return -1;
	237	}
	238	err = filter(&nladdr, h, arg1);
	239	if (err < 0)
	240	return err;
	241
	242	skip_it:
	243	h = NLMSG_NEXT(h, status);
	244	}
	245	if (msg.msg_flags & MSG_TRUNC) {
	246	fprintf(stderr, "Message truncated\n");
	247	continue;
	248	}
	249	if (status) {
	250	fprintf(stderr, "!!!Remnant of size %d\n", status);
	251	exit(1);
	252	}
	253	}
	254	}
	255
	256	int rtnl_talk(struct rtnl_handle rtnl, struct nlmsghdr n, pid_t peer,
	257	unsigned groups, struct nlmsghdr *answer,
6dc9f016	258	rtnl_filter_t junk,
aba5acdf SH	259	void *jarg)
	260	{
	261	int status;
	262	unsigned seq;
	263	struct nlmsghdr *h;
	264	struct sockaddr_nl nladdr;
fb229759 SH	265	struct iovec iov = {
	266	.iov_base = (void*) n,
	267	.iov_len = n->nlmsg_len
	268	};
aba5acdf	269	struct msghdr msg = {
8ed63ab1 SH	270	.msg_name = &nladdr,
	271	.msg_namelen = sizeof(nladdr),
	272	.msg_iov = &iov,
	273	.msg_iovlen = 1,
aba5acdf	274	};
8ed63ab1	275	char buf[16384];
aba5acdf SH	276
	277	memset(&nladdr, 0, sizeof(nladdr));
	278	nladdr.nl_family = AF_NETLINK;
	279	nladdr.nl_pid = peer;
	280	nladdr.nl_groups = groups;
	281
	282	n->nlmsg_seq = seq = ++rtnl->seq;
007d3a3e	283
aba5acdf SH	284	if (answer == NULL)
	285	n->nlmsg_flags \|= NLM_F_ACK;
	286
	287	status = sendmsg(rtnl->fd, &msg, 0);
	288
	289	if (status < 0) {
	290	perror("Cannot talk to rtnetlink");
	291	return -1;
	292	}
	293
007d3a3e SH	294	memset(buf,0,sizeof(buf));
007d3a3e SH	295
aba5acdf SH	296	iov.iov_base = buf;
	297
	298	while (1) {
	299	iov.iov_len = sizeof(buf);
	300	status = recvmsg(rtnl->fd, &msg, 0);
	301
	302	if (status < 0) {
aa8032e6	303	if (errno == EINTR \|\| errno == EAGAIN)
aba5acdf	304	continue;
aa8032e6 SH	305	fprintf(stderr, "netlink receive error %s (%d)\n",
	306	strerror(errno), errno);
	307	return -1;
aba5acdf SH	308	}
	309	if (status == 0) {
	310	fprintf(stderr, "EOF on netlink\n");
	311	return -1;
	312	}
	313	if (msg.msg_namelen != sizeof(nladdr)) {
	314	fprintf(stderr, "sender address length == %d\n", msg.msg_namelen);
	315	exit(1);
	316	}
	317	for (h = (struct nlmsghdr)buf; status >= sizeof(h); ) {
	318	int err;
	319	int len = h->nlmsg_len;
	320	int l = len - sizeof(*h);
	321
	322	if (l<0 \|\| len>status) {
	323	if (msg.msg_flags & MSG_TRUNC) {
	324	fprintf(stderr, "Truncated message\n");
	325	return -1;
	326	}
	327	fprintf(stderr, "!!!malformed message: len=%d\n", len);
	328	exit(1);
	329	}
	330
10f57ef1	331	if (nladdr.nl_pid != peer \|\|
10f57ef1	332	h->nlmsg_pid != rtnl->local.nl_pid \|\|
aba5acdf SH	333	h->nlmsg_seq != seq) {
	334	if (junk) {
	335	err = junk(&nladdr, h, jarg);
	336	if (err < 0)
	337	return err;
	338	}
4cca16f2 SH	339	/* Don't forget to skip that message. */
	340	status -= NLMSG_ALIGN(len);
	341	h = (struct nlmsghdr)((char)h + NLMSG_ALIGN(len));
aba5acdf SH	342	continue;
	343	}
	344
	345	if (h->nlmsg_type == NLMSG_ERROR) {
	346	struct nlmsgerr err = (struct nlmsgerr)NLMSG_DATA(h);
	347	if (l < sizeof(struct nlmsgerr)) {
	348	fprintf(stderr, "ERROR truncated\n");
	349	} else {
	350	errno = -err->error;
	351	if (errno == 0) {
	352	if (answer)
	353	memcpy(answer, h, h->nlmsg_len);
	354	return 0;
	355	}
	356	perror("RTNETLINK answers");
	357	}
	358	return -1;
	359	}
	360	if (answer) {
	361	memcpy(answer, h, h->nlmsg_len);
	362	return 0;
	363	}
	364
	365	fprintf(stderr, "Unexpected reply!!!\n");
	366
	367	status -= NLMSG_ALIGN(len);
	368	h = (struct nlmsghdr)((char)h + NLMSG_ALIGN(len));
	369	}
	370	if (msg.msg_flags & MSG_TRUNC) {
	371	fprintf(stderr, "Message truncated\n");
	372	continue;
	373	}
	374	if (status) {
	375	fprintf(stderr, "!!!Remnant of size %d\n", status);
	376	exit(1);
	377	}
	378	}
	379	}
	380
8ed63ab1	381	int rtnl_listen(struct rtnl_handle *rtnl,
6dc9f016 SH	382	rtnl_filter_t handler,
6dc9f016 SH	383	void *jarg)
aba5acdf SH	384	{
	385	int status;
	386	struct nlmsghdr *h;
	387	struct sockaddr_nl nladdr;
	388	struct iovec iov;
aba5acdf	389	struct msghdr msg = {
8ed63ab1 SH	390	.msg_name = &nladdr,
	391	.msg_namelen = sizeof(nladdr),
	392	.msg_iov = &iov,
	393	.msg_iovlen = 1,
aba5acdf	394	};
8ed63ab1	395	char buf[8192];
aba5acdf SH	396
	397	memset(&nladdr, 0, sizeof(nladdr));
	398	nladdr.nl_family = AF_NETLINK;
	399	nladdr.nl_pid = 0;
	400	nladdr.nl_groups = 0;
	401
aba5acdf	402	iov.iov_base = buf;
aba5acdf SH	403	while (1) {
	404	iov.iov_len = sizeof(buf);
	405	status = recvmsg(rtnl->fd, &msg, 0);
	406
	407	if (status < 0) {
aa8032e6	408	if (errno == EINTR \|\| errno == EAGAIN)
aba5acdf	409	continue;
aa8032e6 SH	410	fprintf(stderr, "netlink receive error %s (%d)\n",
	411	strerror(errno), errno);
	412	return -1;
aba5acdf SH	413	}
	414	if (status == 0) {
	415	fprintf(stderr, "EOF on netlink\n");
	416	return -1;
	417	}
	418	if (msg.msg_namelen != sizeof(nladdr)) {
	419	fprintf(stderr, "Sender address length == %d\n", msg.msg_namelen);
	420	exit(1);
	421	}
	422	for (h = (struct nlmsghdr)buf; status >= sizeof(h); ) {
	423	int err;
	424	int len = h->nlmsg_len;
	425	int l = len - sizeof(*h);
	426
	427	if (l<0 \|\| len>status) {
	428	if (msg.msg_flags & MSG_TRUNC) {
	429	fprintf(stderr, "Truncated message\n");
	430	return -1;
	431	}
	432	fprintf(stderr, "!!!malformed message: len=%d\n", len);
	433	exit(1);
	434	}
	435
	436	err = handler(&nladdr, h, jarg);
	437	if (err < 0)
	438	return err;
	439
	440	status -= NLMSG_ALIGN(len);
	441	h = (struct nlmsghdr)((char)h + NLMSG_ALIGN(len));
	442	}
	443	if (msg.msg_flags & MSG_TRUNC) {
	444	fprintf(stderr, "Message truncated\n");
	445	continue;
	446	}
	447	if (status) {
	448	fprintf(stderr, "!!!Remnant of size %d\n", status);
	449	exit(1);
	450	}
	451	}
	452	}
	453
6dc9f016 SH	454	int rtnl_from_file(FILE *rtnl, rtnl_filter_t handler,
6dc9f016 SH	455	void *jarg)
aba5acdf SH	456	{
	457	int status;
	458	struct sockaddr_nl nladdr;
	459	char buf[8192];
	460	struct nlmsghdr h = (void)buf;
	461
	462	memset(&nladdr, 0, sizeof(nladdr));
	463	nladdr.nl_family = AF_NETLINK;
	464	nladdr.nl_pid = 0;
	465	nladdr.nl_groups = 0;
	466
	467	while (1) {
	468	int err, len, type;
	469	int l;
	470
	471	status = fread(&buf, 1, sizeof(*h), rtnl);
	472
	473	if (status < 0) {
	474	if (errno == EINTR)
	475	continue;
	476	perror("rtnl_from_file: fread");
	477	return -1;
	478	}
	479	if (status == 0)
	480	return 0;
	481
	482	len = h->nlmsg_len;
	483	type= h->nlmsg_type;
	484	l = len - sizeof(*h);
	485
	486	if (l<0 \|\| len>sizeof(buf)) {
	487	fprintf(stderr, "!!!malformed message: len=%d @%lu\n",
	488	len, ftell(rtnl));
	489	return -1;
	490	}
	491
	492	status = fread(NLMSG_DATA(h), 1, NLMSG_ALIGN(l), rtnl);
	493
	494	if (status < 0) {
	495	perror("rtnl_from_file: fread");
	496	return -1;
	497	}
	498	if (status < l) {
	499	fprintf(stderr, "rtnl-from_file: truncated message\n");
	500	return -1;
	501	}
	502
	503	err = handler(&nladdr, h, jarg);
	504	if (err < 0)
	505	return err;
	506	}
	507	}
	508
	509	int addattr32(struct nlmsghdr *n, int maxlen, int type, __u32 data)
	510	{
	511	int len = RTA_LENGTH(4);
	512	struct rtattr *rta;
007d3a3e SH	513	if (NLMSG_ALIGN(n->nlmsg_len) + len > maxlen) {
007d3a3e SH	514	fprintf(stderr,"addattr32: Error! max allowed bound %d exceeded\n",maxlen);
aba5acdf	515	return -1;
007d3a3e	516	}
07f94362	517	rta = NLMSG_TAIL(n);
aba5acdf SH	518	rta->rta_type = type;
	519	rta->rta_len = len;
	520	memcpy(RTA_DATA(rta), &data, 4);
	521	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + len;
	522	return 0;
	523	}
	524
8ed63ab1	525	int addattr_l(struct nlmsghdr n, int maxlen, int type, const void data,
6dc9f016	526	int alen)
aba5acdf SH	527	{
	528	int len = RTA_LENGTH(alen);
	529	struct rtattr *rta;
	530
3dabdbb3	531	if (NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len) > maxlen) {
007d3a3e	532	fprintf(stderr, "addattr_l ERROR: message exceeded bound of %d\n",maxlen);
aba5acdf	533	return -1;
007d3a3e	534	}
07f94362	535	rta = NLMSG_TAIL(n);
aba5acdf SH	536	rta->rta_type = type;
	537	rta->rta_len = len;
	538	memcpy(RTA_DATA(rta), data, alen);
3dabdbb3	539	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + RTA_ALIGN(len);
aba5acdf SH	540	return 0;
	541	}
	542
07f94362	543	int addraw_l(struct nlmsghdr n, int maxlen, const void data, int len)
	544	{
	545	if (NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len) > maxlen) {
	546	fprintf(stderr, "addraw_l ERROR: message exceeded bound of %d\n",maxlen);
	547	return -1;
	548	}
	549
	550	memcpy(NLMSG_TAIL(n), data, len);
	551	memset((void *) NLMSG_TAIL(n) + len, 0, NLMSG_ALIGN(len) - len);
	552	n->nlmsg_len = NLMSG_ALIGN(n->nlmsg_len) + NLMSG_ALIGN(len);
	553	return 0;
	554	}
	555
2f90c9c0 PM	556	struct rtattr addattr_nest(struct nlmsghdr n, int maxlen, int type)
	557	{
	558	struct rtattr *nest = NLMSG_TAIL(n);
	559
	560	addattr_l(n, maxlen, type, NULL, 0);
	561	return nest;
	562	}
	563
	564	int addattr_nest_end(struct nlmsghdr n, struct rtattr nest)
	565	{
	566	nest->rta_len = (void )NLMSG_TAIL(n) - (void )nest;
	567	return n->nlmsg_len;
	568	}
	569
	570	struct rtattr addattr_nest_compat(struct nlmsghdr n, int maxlen, int type,
	571	const void *data, int len)
	572	{
	573	struct rtattr *start = NLMSG_TAIL(n);
	574
	575	addattr_l(n, maxlen, type, data, len);
	576	addattr_nest(n, maxlen, type);
	577	return start;
	578	}
	579
	580	int addattr_nest_compat_end(struct nlmsghdr n, struct rtattr start)
	581	{
	582	struct rtattr nest = (void )start + NLMSG_ALIGN(start->rta_len);
	583
	584	start->rta_len = (void )NLMSG_TAIL(n) - (void )start;
	585	addattr_nest_end(n, nest);
	586	return n->nlmsg_len;
	587	}
	588
aba5acdf SH	589	int rta_addattr32(struct rtattr *rta, int maxlen, int type, __u32 data)
	590	{
	591	int len = RTA_LENGTH(4);
	592	struct rtattr *subrta;
	593
007d3a3e SH	594	if (RTA_ALIGN(rta->rta_len) + len > maxlen) {
007d3a3e SH	595	fprintf(stderr,"rta_addattr32: Error! max allowed bound %d exceeded\n",maxlen);
aba5acdf	596	return -1;
007d3a3e	597	}
aba5acdf SH	598	subrta = (struct rtattr)(((char)rta) + RTA_ALIGN(rta->rta_len));
	599	subrta->rta_type = type;
	600	subrta->rta_len = len;
	601	memcpy(RTA_DATA(subrta), &data, 4);
	602	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + len;
	603	return 0;
	604	}
	605
8ed63ab1	606	int rta_addattr_l(struct rtattr *rta, int maxlen, int type,
6dc9f016	607	const void *data, int alen)
aba5acdf SH	608	{
	609	struct rtattr *subrta;
	610	int len = RTA_LENGTH(alen);
	611
3dabdbb3	612	if (RTA_ALIGN(rta->rta_len) + RTA_ALIGN(len) > maxlen) {
007d3a3e	613	fprintf(stderr,"rta_addattr_l: Error! max allowed bound %d exceeded\n",maxlen);
aba5acdf	614	return -1;
007d3a3e	615	}
aba5acdf SH	616	subrta = (struct rtattr)(((char)rta) + RTA_ALIGN(rta->rta_len));
	617	subrta->rta_type = type;
	618	subrta->rta_len = len;
	619	memcpy(RTA_DATA(subrta), data, alen);
3dabdbb3	620	rta->rta_len = NLMSG_ALIGN(rta->rta_len) + RTA_ALIGN(len);
aba5acdf SH	621	return 0;
	622	}
	623
aba5acdf SH	624	int parse_rtattr(struct rtattr tb[], int max, struct rtattr rta, int len)
aba5acdf SH	625	{
175e2440	626	memset(tb, 0, sizeof(struct rtattr ) (max + 1));
aba5acdf SH	627	while (RTA_OK(rta, len)) {
	628	if (rta->rta_type <= max)
	629	tb[rta->rta_type] = rta;
	630	rta = RTA_NEXT(rta,len);
	631	}
	632	if (len)
	633	fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
	634	return 0;
	635	}
c7699875	636
	637	int parse_rtattr_byindex(struct rtattr tb[], int max, struct rtattr rta, int len)
	638	{
	639	int i = 0;
175e2440 SH	640
175e2440 SH	641	memset(tb, 0, sizeof(struct rtattr ) max);
c7699875	642	while (RTA_OK(rta, len)) {
175e2440	643	if (rta->rta_type <= max && i < max)
c7699875	644	tb[i++] = rta;
	645	rta = RTA_NEXT(rta,len);
	646	}
	647	if (len)
	648	fprintf(stderr, "!!!Deficit %d, rta_len=%d\n", len, rta->rta_len);
	649	return i;
	650	}
2f90c9c0 PM	651
	652	int __parse_rtattr_nested_compat(struct rtattr tb[], int max, struct rtattr rta,
	653	int len)
	654	{
	655	if (RTA_PAYLOAD(rta) < len)
	656	return -1;
	657	if (RTA_PAYLOAD(rta) >= RTA_ALIGN(len) + sizeof(struct rtattr)) {
	658	rta = RTA_DATA(rta) + RTA_ALIGN(len);
	659	return parse_rtattr_nested(tb, max, rta);
	660	}
037c635e	661	memset(tb, 0, sizeof(struct rtattr ) (max + 1));
2f90c9c0 PM	662	return 0;
2f90c9c0 PM	663	}