[mirror_frr.git] / zebra / zebra_netns_id.c

/* zebra NETNS ID handling routines
 * those routines are implemented locally to avoid having external dependencies.
 * Copyright (C) 2018 6WIND
 *
 * 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.
 *
 * This program 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 General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include "ns.h"
#include "vrf.h"
#include "log.h"
#include "lib_errors.h"

#include "zebra/rib.h"
#include "zebra/zebra_dplane.h"
#if defined(HAVE_NETLINK)

#include <linux/net_namespace.h>
#include <linux/netlink.h>
#include <linux/rtnetlink.h>

#include "zebra_ns.h"
#include "kernel_netlink.h"
#endif /* defined(HAVE_NETLINK) */

#include "zebra/zebra_netns_id.h"
#include "zebra/zebra_errors.h"

/* in case NEWNSID not available, the NSID will be locally obtained
 */
#define NS_BASE_NSID 0

#if defined(HAVE_NETLINK)

#define NETLINK_SOCKET_BUFFER_SIZE 512
#define NETLINK_ALIGNTO             4
#define NETLINK_ALIGN(len)                                                     \
	(((len) + NETLINK_ALIGNTO - 1) & ~(NETLINK_ALIGNTO - 1))
#define NETLINK_NLATTR_LEN(_a, _b)   (unsigned int)((char *)_a - (char *)_b)

#endif /* defined(HAVE_NETLINK) */

static ns_id_t zebra_ns_id_get_fallback(const char *netnspath)
{
	static int zebra_ns_id_local;

	return zebra_ns_id_local++;
}

#if defined(HAVE_NETLINK)

static struct nlmsghdr *initiate_nlh(char *buf, unsigned int *seq, int type)
{
	struct nlmsghdr *nlh;

	nlh = (struct nlmsghdr *)buf;
	nlh->nlmsg_len = NETLINK_ALIGN(sizeof(struct nlmsghdr));

	nlh->nlmsg_type = type;
	nlh->nlmsg_flags = NLM_F_REQUEST;
	if (type == RTM_NEWNSID)
		nlh->nlmsg_flags |= NLM_F_ACK;
	nlh->nlmsg_seq = *seq = time(NULL);
	return nlh;
}

static int send_receive(int sock, struct nlmsghdr *nlh, unsigned int seq,
			char *buf)
{
	int ret;
	static const struct sockaddr_nl snl = {.nl_family = AF_NETLINK};

	ret = sendto(sock, (const void *)nlh, (size_t)nlh->nlmsg_len, 0,
		     (struct sockaddr *)&snl, (socklen_t)sizeof(snl));
	if (ret < 0) {
		flog_err_sys(EC_LIB_SOCKET, "netlink( %u) sendmsg() error: %s",
			     sock, safe_strerror(errno));
		return -1;
	}

	/* reception */
	struct sockaddr_nl addr;
	struct iovec iov = {
		.iov_base = buf, .iov_len = NETLINK_SOCKET_BUFFER_SIZE,
	};
	struct msghdr msg = {
		.msg_name = &addr,
		.msg_namelen = sizeof(struct sockaddr_nl),
		.msg_iov = &iov,
		.msg_iovlen = 1,
		.msg_control = NULL,
		.msg_controllen = 0,
		.msg_flags = 0,
	};
	ret = recvmsg(sock, &msg, 0);
	if (ret < 0) {
		flog_err_sys(EC_LIB_SOCKET,
			     "netlink recvmsg: error %d (errno %u)", ret,
			     errno);
		return -1;
	}
	if (msg.msg_flags & MSG_TRUNC) {
		flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
			 "netlink recvmsg : error message truncated");
		return -1;
	}
	/* nlh already points to buf */
	if (nlh->nlmsg_seq != seq) {
		flog_err(
			EC_ZEBRA_NETLINK_BAD_SEQUENCE,
			"netlink recvmsg: bad sequence number %x (expected %x)",
			seq, nlh->nlmsg_seq);
		return -1;
	}
	return ret;
}

/* extract on a valid nlmsg the nsid
 * valid nlmsghdr - not a nlmsgerr
 */
static ns_id_t extract_nsid(struct nlmsghdr *nlh, char *buf)
{
	ns_id_t ns_id = NS_UNKNOWN;
	int offset = NETLINK_ALIGN(sizeof(struct nlmsghdr))
		     + NETLINK_ALIGN(sizeof(struct rtgenmsg));
	int curr_length = offset;
	void *tail = (void *)((char *)nlh + NETLINK_ALIGN(nlh->nlmsg_len));
	struct nlattr *attr;

	for (attr = (struct nlattr *)(buf + offset);
	     NETLINK_NLATTR_LEN(tail, attr) >= sizeof(struct nlattr)
	     && attr->nla_len >= sizeof(struct nlattr)
	     && attr->nla_len <= NETLINK_NLATTR_LEN(tail, attr);
	     attr += NETLINK_ALIGN(attr->nla_len)) {
		curr_length += attr->nla_len;
		if ((attr->nla_type & NLA_TYPE_MASK) == NETNSA_NSID) {
			uint32_t *ptr = (uint32_t *)(attr);

			ns_id = ptr[1];
			break;
		}
	}
	return ns_id;
}

/* fd_param = -1 is ignored.
 * netnspath set to null is ignored.
 * one of the 2 params is mandatory. netnspath is looked in priority
 */
ns_id_t zebra_ns_id_get(const char *netnspath, int fd_param)
{
	int ns_id = -1;
	struct sockaddr_nl snl;
	int fd = -1, sock, ret;
	unsigned int seq;
	ns_id_t return_nsid = NS_UNKNOWN;

	/* netns path check */
	if (!netnspath && fd_param == -1)
		return NS_UNKNOWN;
	if (netnspath)  {
		fd = open(netnspath, O_RDONLY);
		if (fd == -1)
			return NS_UNKNOWN;
	} else if (fd_param != -1)
		fd = fd_param;
	/* netlink socket */
	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	if (sock < 0) {
		flog_err_sys(EC_LIB_SOCKET, "netlink( %u) socket() error: %s",
			     sock, safe_strerror(errno));
		if (netnspath)
			close(fd);
		return NS_UNKNOWN;
	}
	memset(&snl, 0, sizeof(snl));
	snl.nl_family = AF_NETLINK;
	snl.nl_groups = RTNLGRP_NSID;
	snl.nl_pid = 0; /* AUTO PID */
	ret = bind(sock, (struct sockaddr *)&snl, sizeof(snl));
	if (ret < 0) {
		flog_err_sys(EC_LIB_SOCKET,
			     "netlink( %u) socket() bind error: %s", sock,
			     safe_strerror(errno));
		close(sock);
		if (netnspath)
			close(fd);
		return NS_UNKNOWN;
	}

	/* message to send to netlink,and response : NEWNSID */
	char buf[NETLINK_SOCKET_BUFFER_SIZE];
	struct nlmsghdr *nlh;
	struct rtgenmsg *rt;
	int len;

	memset(buf, 0, NETLINK_SOCKET_BUFFER_SIZE);
	nlh = initiate_nlh(buf, &seq, RTM_NEWNSID);
	rt = (struct rtgenmsg *)(buf + nlh->nlmsg_len);
	nlh->nlmsg_len += NETLINK_ALIGN(sizeof(struct rtgenmsg));
	rt->rtgen_family = AF_UNSPEC;

	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_FD, fd);
	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_NSID, ns_id);

	ret = send_receive(sock, nlh, seq, buf);
	if (ret < 0) {
		close(sock);
		if (netnspath)
			close(fd);
		return NS_UNKNOWN;
	}
	nlh = (struct nlmsghdr *)buf;

	/* message to analyse : NEWNSID response */
	ret = 0;
	if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
		return_nsid = extract_nsid(nlh, buf);
	} else {
		if (nlh->nlmsg_type == NLMSG_ERROR) {
			struct nlmsgerr *err =
				(struct nlmsgerr
					 *)((char *)nlh
					    + NETLINK_ALIGN(
						      sizeof(struct nlmsghdr)));

			ret = -1;
			if (err->error < 0)
				errno = -err->error;
			else
				errno = err->error;
			if (errno == 0) {
				/* request NEWNSID was successfull
				 * return EEXIST error to get GETNSID
				 */
				errno = EEXIST;
			}
		} else {
			/* other errors ignored
			 * attempt to get nsid
			 */
			ret = -1;
			errno = EEXIST;
		}
	}

	if (ret <= 0) {
		if (errno != EEXIST && ret != 0) {
			flog_err(
				EC_LIB_SOCKET,
				"netlink( %u) recvfrom() error 2 when reading: %s",
				fd, safe_strerror(errno));
			close(sock);
			if (netnspath)
				close(fd);
			if (errno == ENOTSUP) {
				zlog_debug("NEWNSID locally generated");
				return zebra_ns_id_get_fallback(netnspath);
			}
			return NS_UNKNOWN;
		}
		/* message to send to netlink : GETNSID */
		memset(buf, 0, NETLINK_SOCKET_BUFFER_SIZE);
		nlh = initiate_nlh(buf, &seq, RTM_GETNSID);
		rt = (struct rtgenmsg *)(buf + nlh->nlmsg_len);
		nlh->nlmsg_len += NETLINK_ALIGN(sizeof(struct rtgenmsg));
		rt->rtgen_family = AF_UNSPEC;

		nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_FD, fd);
		nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_NSID,
			      ns_id);

		ret = send_receive(sock, nlh, seq, buf);
		if (ret < 0) {
			close(sock);
			if (netnspath)
				close(fd);
			return NS_UNKNOWN;
		}
		nlh = (struct nlmsghdr *)buf;
		len = ret;
		ret = 0;
		do {
			if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
				return_nsid = extract_nsid(nlh, buf);
				if (return_nsid != NS_UNKNOWN)
					break;
			} else if (nlh->nlmsg_type == NLMSG_ERROR) {
				struct nlmsgerr *err =
					(struct nlmsgerr
						 *)((char *)nlh
						    + NETLINK_ALIGN(sizeof(
							      struct
							      nlmsghdr)));
				if (err->error < 0)
					errno = -err->error;
				else
					errno = err->error;
				break;
			}
			len = len - NETLINK_ALIGN(nlh->nlmsg_len);
			nlh = (struct nlmsghdr *)((char *)nlh
						  + NETLINK_ALIGN(
							    nlh->nlmsg_len));
		} while (len != 0 && ret == 0);
	}

	if (netnspath)
		close(fd);
	close(sock);
	return return_nsid;
}

#else
ns_id_t zebra_ns_id_get(const char *netnspath, int fd __attribute__ ((unused)))
{
	return zebra_ns_id_get_fallback(netnspath);
}

#endif /* ! defined(HAVE_NETLINK) */

#ifdef HAVE_NETNS
static void zebra_ns_create_netns_directory(void)
{
	/* check that /var/run/netns is created */
	/* S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH */
	if (mkdir(NS_RUN_DIR, 0755)) {
		if (errno != EEXIST) {
			flog_warn(EC_ZEBRA_NAMESPACE_DIR_INACCESSIBLE,
				  "NS check: failed to access %s", NS_RUN_DIR);
			return;
		}
	}
}
#endif

ns_id_t zebra_ns_id_get_default(void)
{
#ifdef HAVE_NETNS
	int fd;
#endif /* !HAVE_NETNS */

#ifdef HAVE_NETNS
	if (vrf_is_backend_netns())
		zebra_ns_create_netns_directory();
	fd = open(NS_DEFAULT_NAME, O_RDONLY);

	if (fd == -1)
		return NS_DEFAULT;
	if (!vrf_is_backend_netns()) {
		close(fd);
		return NS_DEFAULT;
	}
	close(fd);
	return zebra_ns_id_get((char *)NS_DEFAULT_NAME, -1);
#else  /* HAVE_NETNS */
	return NS_DEFAULT;
#endif /* !HAVE_NETNS */
}
Commit	Line	Data
05895ad0 PG	1	/* zebra NETNS ID handling routines
	2	* those routines are implemented locally to avoid having external dependencies.
	3	* Copyright (C) 2018 6WIND
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms of the GNU General Public License as published by the Free
	7	* Software Foundation; either version 2 of the License, or (at your option)
	8	* any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful, but WITHOUT
	11	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	12	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	13	* more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along
	16	* with this program; see the file COPYING; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	18	*/
	19
	20	#include <zebra.h>
	21
	22	#include "ns.h"
ec31f30d	23	#include "vrf.h"
05895ad0	24	#include "log.h"
43e52561	25	#include "lib_errors.h"
05895ad0	26
85a75f1e MS	27	#include "zebra/rib.h"
85a75f1e MS	28	#include "zebra/zebra_dplane.h"
05895ad0 PG	29	#if defined(HAVE_NETLINK)
	30
	31	#include <linux/net_namespace.h>
	32	#include <linux/netlink.h>
	33	#include <linux/rtnetlink.h>
	34
05895ad0 PG	35	#include "zebra_ns.h"
	36	#include "kernel_netlink.h"
	37	#endif /* defined(HAVE_NETLINK) */
	38
43e52561 QY	39	#include "zebra/zebra_netns_id.h"
43e52561 QY	40	#include "zebra/zebra_errors.h"
05895ad0 PG	41
	42	/* in case NEWNSID not available, the NSID will be locally obtained
	43	*/
	44	#define NS_BASE_NSID 0
	45
	46	#if defined(HAVE_NETLINK)
	47
	48	#define NETLINK_SOCKET_BUFFER_SIZE 512
	49	#define NETLINK_ALIGNTO 4
996c9314 LB	50	#define NETLINK_ALIGN(len) \
996c9314 LB	51	(((len) + NETLINK_ALIGNTO - 1) & ~(NETLINK_ALIGNTO - 1))
05895ad0 PG	52	#define NETLINK_NLATTR_LEN(_a, _b) (unsigned int)((char )_a - (char )_b)
	53
	54	#endif /* defined(HAVE_NETLINK) */
	55
	56	static ns_id_t zebra_ns_id_get_fallback(const char *netnspath)
	57	{
	58	static int zebra_ns_id_local;
	59
	60	return zebra_ns_id_local++;
	61	}
	62
	63	#if defined(HAVE_NETLINK)
	64
	65	static struct nlmsghdr initiate_nlh(char buf, unsigned int *seq, int type)
	66	{
	67	struct nlmsghdr *nlh;
	68
	69	nlh = (struct nlmsghdr *)buf;
	70	nlh->nlmsg_len = NETLINK_ALIGN(sizeof(struct nlmsghdr));
	71
	72	nlh->nlmsg_type = type;
	73	nlh->nlmsg_flags = NLM_F_REQUEST;
	74	if (type == RTM_NEWNSID)
	75	nlh->nlmsg_flags \|= NLM_F_ACK;
	76	nlh->nlmsg_seq = *seq = time(NULL);
	77	return nlh;
	78	}
	79
996c9314 LB	80	static int send_receive(int sock, struct nlmsghdr *nlh, unsigned int seq,
996c9314 LB	81	char *buf)
05895ad0 PG	82	{
05895ad0 PG	83	int ret;
996c9314	84	static const struct sockaddr_nl snl = {.nl_family = AF_NETLINK};
05895ad0 PG	85
05895ad0 PG	86	ret = sendto(sock, (const void *)nlh, (size_t)nlh->nlmsg_len, 0,
996c9314	87	(struct sockaddr *)&snl, (socklen_t)sizeof(snl));
05895ad0	88	if (ret < 0) {
450971aa	89	flog_err_sys(EC_LIB_SOCKET, "netlink( %u) sendmsg() error: %s",
09c866e3	90	sock, safe_strerror(errno));
05895ad0 PG	91	return -1;
	92	}
	93
	94	/* reception */
	95	struct sockaddr_nl addr;
	96	struct iovec iov = {
996c9314	97	.iov_base = buf, .iov_len = NETLINK_SOCKET_BUFFER_SIZE,
05895ad0 PG	98	};
05895ad0 PG	99	struct msghdr msg = {
996c9314 LB	100	.msg_name = &addr,
	101	.msg_namelen = sizeof(struct sockaddr_nl),
	102	.msg_iov = &iov,
	103	.msg_iovlen = 1,
	104	.msg_control = NULL,
05895ad0	105	.msg_controllen = 0,
996c9314	106	.msg_flags = 0,
05895ad0 PG	107	};
	108	ret = recvmsg(sock, &msg, 0);
	109	if (ret < 0) {
450971aa	110	flog_err_sys(EC_LIB_SOCKET,
09c866e3 QY	111	"netlink recvmsg: error %d (errno %u)", ret,
09c866e3 QY	112	errno);
05895ad0 PG	113	return -1;
	114	}
	115	if (msg.msg_flags & MSG_TRUNC) {
e914ccbe	116	flog_err(EC_ZEBRA_NETLINK_LENGTH_ERROR,
1c50c1c0	117	"netlink recvmsg : error message truncated");
05895ad0 PG	118	return -1;
	119	}
	120	/* nlh already points to buf */
	121	if (nlh->nlmsg_seq != seq) {
af4c2728	122	flog_err(
e914ccbe	123	EC_ZEBRA_NETLINK_BAD_SEQUENCE,
996c9314 LB	124	"netlink recvmsg: bad sequence number %x (expected %x)",
996c9314 LB	125	seq, nlh->nlmsg_seq);
05895ad0 PG	126	return -1;
	127	}
	128	return ret;
	129	}
	130
	131	/* extract on a valid nlmsg the nsid
	132	* valid nlmsghdr - not a nlmsgerr
	133	*/
	134	static ns_id_t extract_nsid(struct nlmsghdr nlh, char buf)
	135	{
	136	ns_id_t ns_id = NS_UNKNOWN;
996c9314 LB	137	int offset = NETLINK_ALIGN(sizeof(struct nlmsghdr))
996c9314 LB	138	+ NETLINK_ALIGN(sizeof(struct rtgenmsg));
05895ad0 PG	139	int curr_length = offset;
	140	void tail = (void )((char *)nlh + NETLINK_ALIGN(nlh->nlmsg_len));
	141	struct nlattr *attr;
	142
c4efd0f4	143	for (attr = (struct nlattr *)(buf + offset);
996c9314 LB	144	NETLINK_NLATTR_LEN(tail, attr) >= sizeof(struct nlattr)
	145	&& attr->nla_len >= sizeof(struct nlattr)
	146	&& attr->nla_len <= NETLINK_NLATTR_LEN(tail, attr);
05895ad0 PG	147	attr += NETLINK_ALIGN(attr->nla_len)) {
	148	curr_length += attr->nla_len;
	149	if ((attr->nla_type & NLA_TYPE_MASK) == NETNSA_NSID) {
d7c0a89a	150	uint32_t ptr = (uint32_t )(attr);
05895ad0 PG	151
	152	ns_id = ptr[1];
	153	break;
	154	}
	155	}
	156	return ns_id;
	157	}
	158
289b0f0d PG	159	/* fd_param = -1 is ignored.
	160	* netnspath set to null is ignored.
	161	* one of the 2 params is mandatory. netnspath is looked in priority
	162	*/
	163	ns_id_t zebra_ns_id_get(const char *netnspath, int fd_param)
05895ad0 PG	164	{
	165	int ns_id = -1;
	166	struct sockaddr_nl snl;
289b0f0d	167	int fd = -1, sock, ret;
05895ad0 PG	168	unsigned int seq;
	169	ns_id_t return_nsid = NS_UNKNOWN;
	170
	171	/* netns path check */
289b0f0d	172	if (!netnspath && fd_param == -1)
bd23c840	173	return NS_UNKNOWN;
289b0f0d PG	174	if (netnspath) {
	175	fd = open(netnspath, O_RDONLY);
	176	if (fd == -1)
	177	return NS_UNKNOWN;
	178	} else if (fd_param != -1)
	179	fd = fd_param;
05895ad0 PG	180	/* netlink socket */
	181	sock = socket(AF_NETLINK, SOCK_RAW, NETLINK_ROUTE);
	182	if (sock < 0) {
450971aa	183	flog_err_sys(EC_LIB_SOCKET, "netlink( %u) socket() error: %s",
09c866e3	184	sock, safe_strerror(errno));
7529bf8f	185	if (netnspath)
289b0f0d	186	close(fd);
05895ad0 PG	187	return NS_UNKNOWN;
	188	}
	189	memset(&snl, 0, sizeof(snl));
	190	snl.nl_family = AF_NETLINK;
	191	snl.nl_groups = RTNLGRP_NSID;
	192	snl.nl_pid = 0; /* AUTO PID */
	193	ret = bind(sock, (struct sockaddr *)&snl, sizeof(snl));
	194	if (ret < 0) {
450971aa	195	flog_err_sys(EC_LIB_SOCKET,
09c866e3 QY	196	"netlink( %u) socket() bind error: %s", sock,
09c866e3 QY	197	safe_strerror(errno));
05895ad0	198	close(sock);
7529bf8f	199	if (netnspath)
289b0f0d	200	close(fd);
05895ad0 PG	201	return NS_UNKNOWN;
	202	}
	203
	204	/* message to send to netlink,and response : NEWNSID */
	205	char buf[NETLINK_SOCKET_BUFFER_SIZE];
	206	struct nlmsghdr *nlh;
	207	struct rtgenmsg *rt;
	208	int len;
	209
	210	memset(buf, 0, NETLINK_SOCKET_BUFFER_SIZE);
	211	nlh = initiate_nlh(buf, &seq, RTM_NEWNSID);
	212	rt = (struct rtgenmsg *)(buf + nlh->nlmsg_len);
	213	nlh->nlmsg_len += NETLINK_ALIGN(sizeof(struct rtgenmsg));
	214	rt->rtgen_family = AF_UNSPEC;
	215
312a6bee JU	216	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_FD, fd);
312a6bee JU	217	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_NSID, ns_id);
05895ad0 PG	218
	219	ret = send_receive(sock, nlh, seq, buf);
	220	if (ret < 0) {
	221	close(sock);
7529bf8f	222	if (netnspath)
289b0f0d	223	close(fd);
05895ad0 PG	224	return NS_UNKNOWN;
	225	}
	226	nlh = (struct nlmsghdr *)buf;
	227
	228	/* message to analyse : NEWNSID response */
05895ad0	229	ret = 0;
b5891e15 A	230	if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
	231	return_nsid = extract_nsid(nlh, buf);
	232	} else {
	233	if (nlh->nlmsg_type == NLMSG_ERROR) {
	234	struct nlmsgerr *err =
	235	(struct nlmsgerr
	236	)((char )nlh
	237	+ NETLINK_ALIGN(
	238	sizeof(struct nlmsghdr)));
	239
	240	ret = -1;
	241	if (err->error < 0)
	242	errno = -err->error;
	243	else
	244	errno = err->error;
	245	if (errno == 0) {
	246	/* request NEWNSID was successfull
	247	* return EEXIST error to get GETNSID
05895ad0	248	*/
05895ad0	249	errno = EEXIST;
05895ad0	250	}
b5891e15 A	251	} else {
	252	/* other errors ignored
	253	* attempt to get nsid
	254	*/
	255	ret = -1;
	256	errno = EEXIST;
05895ad0	257	}
b5891e15	258	}
05895ad0 PG	259
	260	if (ret <= 0) {
	261	if (errno != EEXIST && ret != 0) {
af4c2728	262	flog_err(
450971aa	263	EC_LIB_SOCKET,
996c9314 LB	264	"netlink( %u) recvfrom() error 2 when reading: %s",
996c9314 LB	265	fd, safe_strerror(errno));
05895ad0	266	close(sock);
7529bf8f	267	if (netnspath)
289b0f0d	268	close(fd);
05895ad0	269	if (errno == ENOTSUP) {
9df414fe	270	zlog_debug("NEWNSID locally generated");
05895ad0 PG	271	return zebra_ns_id_get_fallback(netnspath);
	272	}
	273	return NS_UNKNOWN;
	274	}
	275	/* message to send to netlink : GETNSID */
	276	memset(buf, 0, NETLINK_SOCKET_BUFFER_SIZE);
	277	nlh = initiate_nlh(buf, &seq, RTM_GETNSID);
	278	rt = (struct rtgenmsg *)(buf + nlh->nlmsg_len);
	279	nlh->nlmsg_len += NETLINK_ALIGN(sizeof(struct rtgenmsg));
	280	rt->rtgen_family = AF_UNSPEC;
	281
312a6bee JU	282	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_FD, fd);
	283	nl_attr_put32(nlh, NETLINK_SOCKET_BUFFER_SIZE, NETNSA_NSID,
	284	ns_id);
05895ad0 PG	285
	286	ret = send_receive(sock, nlh, seq, buf);
	287	if (ret < 0) {
	288	close(sock);
7529bf8f	289	if (netnspath)
289b0f0d	290	close(fd);
05895ad0 PG	291	return NS_UNKNOWN;
	292	}
	293	nlh = (struct nlmsghdr *)buf;
	294	len = ret;
	295	ret = 0;
	296	do {
	297	if (nlh->nlmsg_type >= NLMSG_MIN_TYPE) {
	298	return_nsid = extract_nsid(nlh, buf);
	299	if (return_nsid != NS_UNKNOWN)
	300	break;
	301	} else if (nlh->nlmsg_type == NLMSG_ERROR) {
996c9314 LB	302	struct nlmsgerr *err =
	303	(struct nlmsgerr
	304	)((char )nlh
	305	+ NETLINK_ALIGN(sizeof(
	306	struct
	307	nlmsghdr)));
05895ad0 PG	308	if (err->error < 0)
	309	errno = -err->error;
	310	else
	311	errno = err->error;
	312	break;
	313	}
	314	len = len - NETLINK_ALIGN(nlh->nlmsg_len);
996c9314 LB	315	nlh = (struct nlmsghdr )((char )nlh
	316	+ NETLINK_ALIGN(
	317	nlh->nlmsg_len));
0cfbff74	318	} while (len != 0 && ret == 0);
05895ad0 PG	319	}
05895ad0 PG	320
7529bf8f	321	if (netnspath)
289b0f0d	322	close(fd);
05895ad0 PG	323	close(sock);
	324	return return_nsid;
	325	}
	326
	327	#else
289b0f0d	328	ns_id_t zebra_ns_id_get(const char *netnspath, int fd __attribute__ ((unused)))
05895ad0 PG	329	{
	330	return zebra_ns_id_get_fallback(netnspath);
	331	}
2d4e4d39	332
05895ad0	333	#endif /* ! defined(HAVE_NETLINK) */
ec31f30d PG	334
	335	#ifdef HAVE_NETNS
	336	static void zebra_ns_create_netns_directory(void)
	337	{
	338	/* check that /var/run/netns is created */
	339	/* S_IRWXU\|S_IRGRP\|S_IXGRP\|S_IROTH\|S_IXOTH */
	340	if (mkdir(NS_RUN_DIR, 0755)) {
	341	if (errno != EEXIST) {
e914ccbe	342	flog_warn(EC_ZEBRA_NAMESPACE_DIR_INACCESSIBLE,
9df414fe	343	"NS check: failed to access %s", NS_RUN_DIR);
ec31f30d PG	344	return;
	345	}
	346	}
	347	}
	348	#endif
	349
	350	ns_id_t zebra_ns_id_get_default(void)
	351	{
	352	#ifdef HAVE_NETNS
	353	int fd;
	354	#endif /* !HAVE_NETNS */
	355
	356	#ifdef HAVE_NETNS
	357	if (vrf_is_backend_netns())
	358	zebra_ns_create_netns_directory();
	359	fd = open(NS_DEFAULT_NAME, O_RDONLY);
	360
	361	if (fd == -1)
1eb92f06	362	return NS_DEFAULT;
4307629f DS	363	if (!vrf_is_backend_netns()) {
4307629f DS	364	close(fd);
1eb92f06	365	return NS_DEFAULT;
4307629f	366	}
ec31f30d	367	close(fd);
289b0f0d	368	return zebra_ns_id_get((char *)NS_DEFAULT_NAME, -1);
996c9314	369	#else /* HAVE_NETNS */
1eb92f06	370	return NS_DEFAULT;
ec31f30d PG	371	#endif /* !HAVE_NETNS */
ec31f30d PG	372	}