[mirror_lxc.git] / src / lxc / nl.c

/*
 * lxc: linux Container library
 *
 * (C) Copyright IBM Corp. 2007, 2008
 *
 * Authors:
 * Daniel Lezcano <dlezcano at fr.ibm.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */
#include <sys/socket.h>
#include <string.h>
#include <stdio.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#include <stdlib.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>
#include <nl.h>

#define NLMSG_TAIL(nmsg) \
        ((struct rtattr *) (((void *) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))

extern size_t nlmsg_len(const struct nlmsg *nlmsg)
{
	return nlmsg->nlmsghdr.nlmsg_len - NLMSG_HDRLEN;
}

extern void *nlmsg_data(struct nlmsg *nlmsg)
{
	char *data = ((char *)nlmsg) + NLMSG_ALIGN(sizeof(struct nlmsghdr));
	if (!nlmsg_len(nlmsg))
		return NULL;
	return data;
}

static int nla_put(struct nlmsg *nlmsg, int attr, 
		   const void *data, size_t len)
{
	struct rtattr *rta;
	size_t rtalen = RTA_LENGTH(len);
	
        rta = NLMSG_TAIL(&nlmsg->nlmsghdr);
        rta->rta_type = attr;
        rta->rta_len = rtalen;
        memcpy(RTA_DATA(rta), data, len);
        nlmsg->nlmsghdr.nlmsg_len =
		NLMSG_ALIGN(nlmsg->nlmsghdr.nlmsg_len) + RTA_ALIGN(rtalen);
	return 0;
}

extern int nla_put_buffer(struct nlmsg *nlmsg, int attr, 
			  const void *data, size_t size)
{
	return nla_put(nlmsg, attr, data, size);
}

extern int nla_put_string(struct nlmsg *nlmsg, int attr, const char *string)
{
        return nla_put(nlmsg, attr, string, strlen(string) + 1);
}

extern int nla_put_u32(struct nlmsg *nlmsg, int attr, int value)
{
	return nla_put(nlmsg, attr, &value, sizeof(value));
}

extern int nla_put_u16(struct nlmsg *nlmsg, int attr, ushort value)
{
	return nla_put(nlmsg, attr, &value, 2);
}

extern int nla_put_attr(struct nlmsg *nlmsg, int attr)
{
	return nla_put(nlmsg, attr, NULL, 0);
}

struct rtattr *nla_begin_nested(struct nlmsg *nlmsg, int attr)
{
	struct rtattr *rtattr = NLMSG_TAIL(&nlmsg->nlmsghdr);

	if (nla_put_attr(nlmsg, attr))
		return NULL;

	return rtattr;
}

void nla_end_nested(struct nlmsg *nlmsg, struct rtattr *attr)
{
	attr->rta_len = (void *)NLMSG_TAIL(&nlmsg->nlmsghdr) - (void *)attr;
}

extern struct nlmsg *nlmsg_alloc(size_t size)
{
	struct nlmsg *nlmsg;
	size_t len = NLMSG_ALIGN(size) + NLMSG_ALIGN(sizeof(struct nlmsghdr *));

	nlmsg = (struct nlmsg *)malloc(len);
	if (!nlmsg)
		return NULL;

	memset(nlmsg, 0, len);
	nlmsg->nlmsghdr.nlmsg_len = NLMSG_ALIGN(size);

	return nlmsg;
}

extern void nlmsg_free(struct nlmsg *nlmsg)
{
	free(nlmsg);
}

extern int netlink_rcv(struct nl_handler *handler, struct nlmsg *answer)
{
	int ret;
        struct sockaddr_nl nladdr;
        struct iovec iov = {
                .iov_base = answer,
                .iov_len = answer->nlmsghdr.nlmsg_len,
        };
	
	struct msghdr msg = {
                .msg_name = &nladdr,
                .msg_namelen = sizeof(nladdr),
                .msg_iov = &iov,
                .msg_iovlen = 1,
        };
	
        memset(&nladdr, 0, sizeof(nladdr));
        nladdr.nl_family = AF_NETLINK;
        nladdr.nl_pid = 0;
        nladdr.nl_groups = 0;

again:
	ret = recvmsg(handler->fd, &msg, 0);
	if (ret < 0) {
		if (errno == EINTR)
			goto again;
		return -errno;
	}

	if (!ret)
		return 0;

	if (msg.msg_flags & MSG_TRUNC &&
	    ret == answer->nlmsghdr.nlmsg_len)
		return -EMSGSIZE;

	return ret;
}

extern int netlink_send(struct nl_handler *handler, struct nlmsg *nlmsg)
{
        struct sockaddr_nl nladdr;
        struct iovec iov = {
                .iov_base = (void*)nlmsg,
                .iov_len = nlmsg->nlmsghdr.nlmsg_len,
        };
	struct msghdr msg = {
                .msg_name = &nladdr,
                .msg_namelen = sizeof(nladdr),
                .msg_iov = &iov,
                .msg_iovlen = 1,
        };
	int ret;
	
        memset(&nladdr, 0, sizeof(nladdr));
        nladdr.nl_family = AF_NETLINK;
        nladdr.nl_pid = 0;
        nladdr.nl_groups = 0;

	ret = sendmsg(handler->fd, &msg, 0);
	if (ret < 0)
		return -errno;

	return ret;
}

#ifndef NLMSG_ERROR
#define NLMSG_ERROR                0x2
#endif
extern int netlink_transaction(struct nl_handler *handler, 
			       struct nlmsg *request, struct nlmsg *answer)
{
	int ret;

	ret = netlink_send(handler, request);
	if (ret < 0)
		return ret;

	ret = netlink_rcv(handler, answer);
	if (ret < 0)
		return ret;

	if (answer->nlmsghdr.nlmsg_type == NLMSG_ERROR) {
		struct nlmsgerr *err = (struct nlmsgerr*)NLMSG_DATA(answer);
		return err->error;
	}

	return 0;
}

extern int netlink_open(struct nl_handler *handler, int protocol)
{
	socklen_t socklen;
        int sndbuf = 32768;
        int rcvbuf = 32768;

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

        handler->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
        if (handler->fd < 0)
                return -errno;

        if (setsockopt(handler->fd, SOL_SOCKET, SO_SNDBUF, 
		       &sndbuf, sizeof(sndbuf)) < 0)
                return -errno;

        if (setsockopt(handler->fd, SOL_SOCKET, SO_RCVBUF, 
		       &rcvbuf,sizeof(rcvbuf)) < 0)
                return -errno;

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

        if (bind(handler->fd, (struct sockaddr*)&handler->local, 
		 sizeof(handler->local)) < 0)
                return -errno;

        socklen = sizeof(handler->local);
        if (getsockname(handler->fd, (struct sockaddr*)&handler->local, 
			&socklen) < 0)
                return -errno;

        if (socklen != sizeof(handler->local))
                return -EINVAL;

        if (handler->local.nl_family != AF_NETLINK)
                return -EINVAL;

	handler->seq = time(NULL);

        return 0;
}

extern int netlink_close(struct nl_handler *handler)
{
	close(handler->fd);
	handler->fd = -1;
	return 0;
}
Commit	Line	Data
0ad19a3f	1	/*
	2	* lxc: linux Container library
	3	*
	4	* (C) Copyright IBM Corp. 2007, 2008
	5	*
	6	* Authors:
	7	* Daniel Lezcano <dlezcano at fr.ibm.com>
	8	*
	9	* This library is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU Lesser General Public
	11	* License as published by the Free Software Foundation; either
	12	* version 2.1 of the License, or (at your option) any later version.
	13	*
	14	* This library is distributed in the hope that it will be useful,
	15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	17	* Lesser General Public License for more details.
	18	*
	19	* You should have received a copy of the GNU Lesser General Public
	20	* License along with this library; if not, write to the Free Software
	21	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	22	*/
	23	#include <sys/socket.h>
	24	#include <string.h>
	25	#include <stdio.h>
	26	#include <time.h>
	27	#include <unistd.h>
	28	#include <errno.h>
	29	#include <stdlib.h>
	30	#include <linux/netlink.h>
	31	#include <linux/rtnetlink.h>
	32	#include <nl.h>
	33
	34	#define NLMSG_TAIL(nmsg) \
	35	((struct rtattr ) (((void ) (nmsg)) + NLMSG_ALIGN((nmsg)->nlmsg_len)))
	36
	37	extern size_t nlmsg_len(const struct nlmsg *nlmsg)
	38	{
	39	return nlmsg->nlmsghdr.nlmsg_len - NLMSG_HDRLEN;
	40	}
	41
	42	extern void nlmsg_data(struct nlmsg nlmsg)
	43	{
	44	char data = ((char )nlmsg) + NLMSG_ALIGN(sizeof(struct nlmsghdr));
	45	if (!nlmsg_len(nlmsg))
	46	return NULL;
	47	return data;
	48	}
	49
	50	static int nla_put(struct nlmsg *nlmsg, int attr,
	51	const void *data, size_t len)
	52	{
	53	struct rtattr *rta;
	54	size_t rtalen = RTA_LENGTH(len);
	55
	56	rta = NLMSG_TAIL(&nlmsg->nlmsghdr);
	57	rta->rta_type = attr;
	58	rta->rta_len = rtalen;
	59	memcpy(RTA_DATA(rta), data, len);
	60	nlmsg->nlmsghdr.nlmsg_len =
	61	NLMSG_ALIGN(nlmsg->nlmsghdr.nlmsg_len) + RTA_ALIGN(rtalen);
	62	return 0;
	63	}
	64
65	extern int nla_put_buffer(struct nlmsg *nlmsg, int attr,
66	const void *data, size_t size)
67	{
68	return nla_put(nlmsg, attr, data, size);
69	}
70
71	extern int nla_put_string(struct nlmsg nlmsg, int attr, const char string)
72	{
73	return nla_put(nlmsg, attr, string, strlen(string) + 1);
74	}
75
76	extern int nla_put_u32(struct nlmsg *nlmsg, int attr, int value)
77	{
78	return nla_put(nlmsg, attr, &value, sizeof(value));
79	}
80
9ddaf3bf JHS	81	extern int nla_put_u16(struct nlmsg *nlmsg, int attr, ushort value)
	82	{
	83	return nla_put(nlmsg, attr, &value, 2);
	84	}
	85
0ad19a3f	86	extern int nla_put_attr(struct nlmsg *nlmsg, int attr)
	87	{
	88	return nla_put(nlmsg, attr, NULL, 0);
	89	}
	90
	91	struct rtattr nla_begin_nested(struct nlmsg nlmsg, int attr)
	92	{
	93	struct rtattr *rtattr = NLMSG_TAIL(&nlmsg->nlmsghdr);
	94
	95	if (nla_put_attr(nlmsg, attr))
	96	return NULL;
	97
	98	return rtattr;
	99	}
	100
	101	void nla_end_nested(struct nlmsg nlmsg, struct rtattr attr)
	102	{
	103	attr->rta_len = (void )NLMSG_TAIL(&nlmsg->nlmsghdr) - (void )attr;
	104	}
	105
	106	extern struct nlmsg *nlmsg_alloc(size_t size)
	107	{
	108	struct nlmsg *nlmsg;
	109	size_t len = NLMSG_ALIGN(size) + NLMSG_ALIGN(sizeof(struct nlmsghdr *));
	110
	111	nlmsg = (struct nlmsg *)malloc(len);
	112	if (!nlmsg)
	113	return NULL;
	114
	115	memset(nlmsg, 0, len);
	116	nlmsg->nlmsghdr.nlmsg_len = NLMSG_ALIGN(size);
	117
	118	return nlmsg;
	119	}
	120
	121	extern void nlmsg_free(struct nlmsg *nlmsg)
	122	{
	123	free(nlmsg);
	124	}
	125
	126	extern int netlink_rcv(struct nl_handler handler, struct nlmsg answer)
	127	{
	128	int ret;
	129	struct sockaddr_nl nladdr;
	130	struct iovec iov = {
	131	.iov_base = answer,
	132	.iov_len = answer->nlmsghdr.nlmsg_len,
	133	};
	134
	135	struct msghdr msg = {
	136	.msg_name = &nladdr,
	137	.msg_namelen = sizeof(nladdr),
	138	.msg_iov = &iov,
	139	.msg_iovlen = 1,
	140	};
	141
	142	memset(&nladdr, 0, sizeof(nladdr));
	143	nladdr.nl_family = AF_NETLINK;
	144	nladdr.nl_pid = 0;
	145	nladdr.nl_groups = 0;
	146
	147	again:
	148	ret = recvmsg(handler->fd, &msg, 0);
	149	if (ret < 0) {
150	if (errno == EINTR)
151	goto again;
152	return -errno;
153	}
154
155	if (!ret)
156	return 0;
157
e239ff31 DL	158	if (msg.msg_flags & MSG_TRUNC &&
e239ff31 DL	159	ret == answer->nlmsghdr.nlmsg_len)
0ad19a3f	160	return -EMSGSIZE;
	161
	162	return ret;
	163	}
	164
	165	extern int netlink_send(struct nl_handler handler, struct nlmsg nlmsg)
	166	{
	167	struct sockaddr_nl nladdr;
	168	struct iovec iov = {
	169	.iov_base = (void*)nlmsg,
	170	.iov_len = nlmsg->nlmsghdr.nlmsg_len,
	171	};
	172	struct msghdr msg = {
	173	.msg_name = &nladdr,
	174	.msg_namelen = sizeof(nladdr),
	175	.msg_iov = &iov,
	176	.msg_iovlen = 1,
	177	};
	178	int ret;
	179
	180	memset(&nladdr, 0, sizeof(nladdr));
	181	nladdr.nl_family = AF_NETLINK;
	182	nladdr.nl_pid = 0;
	183	nladdr.nl_groups = 0;
	184
	185	ret = sendmsg(handler->fd, &msg, 0);
e239ff31	186	if (ret < 0)
0ad19a3f	187	return -errno;
0ad19a3f	188
	189	return ret;
	190	}
	191
9ddaf3bf JHS	192	#ifndef NLMSG_ERROR
	193	#define NLMSG_ERROR 0x2
	194	#endif
0ad19a3f	195	extern int netlink_transaction(struct nl_handler *handler,
	196	struct nlmsg request, struct nlmsg answer)
	197	{
0ad19a3f	198	int ret;
	199
	200	ret = netlink_send(handler, request);
	201	if (ret < 0)
	202	return ret;
	203
	204	ret = netlink_rcv(handler, answer);
	205	if (ret < 0)
	206	return ret;
	207
	208	if (answer->nlmsghdr.nlmsg_type == NLMSG_ERROR) {
	209	struct nlmsgerr err = (struct nlmsgerr)NLMSG_DATA(answer);
3cfc0f3a	210	return err->error;
0ad19a3f	211	}
e239ff31	212
0ad19a3f	213	return 0;
	214	}
	215
	216	extern int netlink_open(struct nl_handler *handler, int protocol)
	217	{
	218	socklen_t socklen;
	219	int sndbuf = 32768;
	220	int rcvbuf = 32768;
	221
	222	memset(handler, 0, sizeof(*handler));
	223
	224	handler->fd = socket(AF_NETLINK, SOCK_RAW, protocol);
	225	if (handler->fd < 0)
	226	return -errno;
	227
	228	if (setsockopt(handler->fd, SOL_SOCKET, SO_SNDBUF,
	229	&sndbuf, sizeof(sndbuf)) < 0)
	230	return -errno;
	231
	232	if (setsockopt(handler->fd, SOL_SOCKET, SO_RCVBUF,
	233	&rcvbuf,sizeof(rcvbuf)) < 0)
	234	return -errno;
	235
	236	memset(&handler->local, 0, sizeof(handler->local));
	237	handler->local.nl_family = AF_NETLINK;
	238	handler->local.nl_groups = 0;
	239
	240	if (bind(handler->fd, (struct sockaddr*)&handler->local,
	241	sizeof(handler->local)) < 0)
	242	return -errno;
	243
	244	socklen = sizeof(handler->local);
	245	if (getsockname(handler->fd, (struct sockaddr*)&handler->local,
	246	&socklen) < 0)
	247	return -errno;
	248
	249	if (socklen != sizeof(handler->local))
	250	return -EINVAL;
	251
	252	if (handler->local.nl_family != AF_NETLINK)
	253	return -EINVAL;
	254
	255	handler->seq = time(NULL);
	256
	257	return 0;
	258	}
	259
	260	extern int netlink_close(struct nl_handler *handler)
	261	{
	262	close(handler->fd);
	263	handler->fd = -1;
	264	return 0;
	265	}
	266