[mirror_frr.git] / zebra / zebra_netns_notify.c

/*
 * Zebra NS collector and notifier for Network NameSpaces
 * Copyright (C) 2017 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>

#ifdef HAVE_NETLINK
#ifdef HAVE_NETNS
#undef _GNU_SOURCE
#define _GNU_SOURCE

#include <sched.h>
#endif
#include <dirent.h>
#include <sys/inotify.h>
#include <sys/stat.h>

#include "thread.h"
#include "ns.h"
#include "command.h"
#include "memory.h"
#include "lib_errors.h"

#include "zserv.h"
#include "zebra_memory.h"
#endif /* defined(HAVE_NETLINK) */

#include "zebra_netns_notify.h"
#include "zebra_netns_id.h"

#ifdef HAVE_NETLINK

/* upon creation of folder under /var/run/netns,
 * wait that netns context is bound to
 * that folder 10 seconds
 */
#define ZEBRA_NS_POLLING_INTERVAL_MSEC     1000
#define ZEBRA_NS_POLLING_MAX_RETRIES  200

DEFINE_MTYPE_STATIC(ZEBRA, NETNS_MISC, "ZebraNetNSInfo")
static struct thread *zebra_netns_notify_current;

struct zebra_netns_info {
	const char *netnspath;
	unsigned int retries;
};

static int zebra_ns_ready_read(struct thread *t);
static void zebra_ns_notify_create_context_from_entry_name(const char *name);
static int zebra_ns_continue_read(struct zebra_netns_info *zns_info,
				  int stop_retry);
static int zebra_ns_notify_read(struct thread *t);

static void zebra_ns_notify_create_context_from_entry_name(const char *name)
{
	char *netnspath = ns_netns_pathname(NULL, name);
	struct vrf *vrf;
	int ret;
	ns_id_t ns_id, ns_id_external;

	if (netnspath == NULL)
		return;

	frr_elevate_privs(&zserv_privs) {
		ns_id = zebra_ns_id_get(netnspath);
	}
	if (ns_id == NS_UNKNOWN)
		return;
	ns_id_external = ns_map_nsid_with_external(ns_id, true);
	/* if VRF with NS ID already present */
	vrf = vrf_lookup_by_id((vrf_id_t)ns_id_external);
	if (vrf) {
		zlog_warn(
			"NS notify : same NSID used by VRF %s. Ignore NS %s creation",
			vrf->name, netnspath);
		return;
	}
	if (vrf_handler_create(NULL, name, &vrf) != CMD_SUCCESS) {
		zlog_warn("NS notify : failed to create VRF %s", name);
		ns_map_nsid_with_external(ns_id, false);
		return;
	}
	frr_elevate_privs(&zserv_privs) {
		ret = vrf_netns_handler_create(NULL, vrf, netnspath,
					       ns_id_external, ns_id);
	}
	if (ret != CMD_SUCCESS) {
		zlog_warn("NS notify : failed to create NS %s", netnspath);
		ns_map_nsid_with_external(ns_id, false);
		vrf_delete(vrf);
		return;
	}
	zlog_info("NS notify : created VRF %s NS %s", name, netnspath);
}

static int zebra_ns_continue_read(struct zebra_netns_info *zns_info,
				  int stop_retry)
{
	void *ns_path_ptr = (void *)zns_info->netnspath;

	if (stop_retry) {
		XFREE(MTYPE_NETNS_MISC, ns_path_ptr);
		XFREE(MTYPE_NETNS_MISC, zns_info);
		return 0;
	}
	thread_add_timer_msec(zebrad.master, zebra_ns_ready_read,
			      (void *)zns_info, ZEBRA_NS_POLLING_INTERVAL_MSEC,
			      NULL);
	return 0;
}

static int zebra_ns_delete(char *name)
{
	struct vrf *vrf = vrf_lookup_by_name(name);
	struct ns *ns;

	if (!vrf) {
		zlog_warn(
			"NS notify : no VRF found using NS %s",
			name);
		return 0;
	}
	/* Clear configured flag and invoke delete. */
	UNSET_FLAG(vrf->status, VRF_CONFIGURED);
	ns = (struct ns *)vrf->ns_ctxt;
	/* the deletion order is the same
	 * as the one used when siging signal is received
	 */
	vrf_delete(vrf);
	if (ns)
		ns_delete(ns);

	zlog_info("NS notify : deleted VRF %s", name);
	return 0;
}


static int zebra_ns_ready_read(struct thread *t)
{
	struct zebra_netns_info *zns_info = THREAD_ARG(t);
	const char *netnspath;
	int err, stop_retry = 0;

	if (!zns_info)
		return 0;
	if (!zns_info->netnspath) {
		XFREE(MTYPE_NETNS_MISC, zns_info);
		return 0;
	}
	netnspath = zns_info->netnspath;
	if (--zns_info->retries == 0)
		stop_retry = 1;
	frr_elevate_privs(&zserv_privs) {
		err = ns_switch_to_netns(netnspath);
	}
	if (err < 0)
		return zebra_ns_continue_read(zns_info, stop_retry);

	/* go back to default ns */
	frr_elevate_privs(&zserv_privs) {
		err = ns_switchback_to_initial();
	}
	if (err < 0)
		return zebra_ns_continue_read(zns_info, stop_retry);

	/* success : close fd and create zns context */
	zebra_ns_notify_create_context_from_entry_name(basename(netnspath));
	return zebra_ns_continue_read(zns_info, 1);
}

static int zebra_ns_notify_read(struct thread *t)
{
	int fd_monitor = THREAD_FD(t);
	struct inotify_event *event;
	char buf[BUFSIZ];
	ssize_t len;

	zebra_netns_notify_current = thread_add_read(
		zebrad.master, zebra_ns_notify_read, NULL, fd_monitor, NULL);
	len = read(fd_monitor, buf, sizeof(buf));
	if (len < 0) {
		zlog_warn("NS notify read: failed to read (%s)",
			  safe_strerror(errno));
		return 0;
	}
	for (event = (struct inotify_event *)buf; (char *)event < &buf[len];
	     event = (struct inotify_event *)((char *)event + sizeof(*event)
					      + event->len)) {
		char *netnspath;
		struct zebra_netns_info *netnsinfo;

		if (!(event->mask & (IN_CREATE | IN_DELETE)))
			continue;
		if (event->mask & IN_DELETE)
			return zebra_ns_delete(event->name);

		if (offsetof(struct inotify_event, name) + event->len
		    >= sizeof(buf)) {
			zlog_err("NS notify read: buffer underflow");
			break;
		}

		if (strnlen(event->name, event->len) == event->len) {
			zlog_err("NS notify error: bad event name");
			break;
		}

		netnspath = ns_netns_pathname(NULL, event->name);
		if (!netnspath)
			continue;
		netnspath = XSTRDUP(MTYPE_NETNS_MISC, netnspath);
		netnsinfo = XCALLOC(MTYPE_NETNS_MISC,
				    sizeof(struct zebra_netns_info));
		netnsinfo->retries = ZEBRA_NS_POLLING_MAX_RETRIES;
		netnsinfo->netnspath = netnspath;
		thread_add_timer_msec(zebrad.master, zebra_ns_ready_read,
				      (void *)netnsinfo, 0, NULL);
	}
	return 0;
}

void zebra_ns_notify_parse(void)
{
	struct dirent *dent;
	DIR *srcdir = opendir(NS_RUN_DIR);

	if (srcdir == NULL) {
		zlog_warn("NS parsing init: failed to parse %s", NS_RUN_DIR);
		return;
	}
	while ((dent = readdir(srcdir)) != NULL) {
		struct stat st;

		if (strcmp(dent->d_name, ".") == 0
		    || strcmp(dent->d_name, "..") == 0)
			continue;
		if (fstatat(dirfd(srcdir), dent->d_name, &st, 0) < 0) {
			zlog_warn("NS parsing init: failed to parse entry %s",
				  dent->d_name);
			continue;
		}
		if (S_ISDIR(st.st_mode)) {
			zlog_warn("NS parsing init: %s is not a NS",
				  dent->d_name);
			continue;
		}
		zebra_ns_notify_create_context_from_entry_name(dent->d_name);
	}
	closedir(srcdir);
}

void zebra_ns_notify_init(void)
{
	int fd_monitor;

	zebra_netns_notify_current = NULL;
	fd_monitor = inotify_init();
	if (fd_monitor < 0) {
		zlog_warn("NS notify init: failed to initialize inotify (%s)",
			  safe_strerror(errno));
	}
	if (inotify_add_watch(fd_monitor, NS_RUN_DIR,
			      IN_CREATE | IN_DELETE) < 0) {
		zlog_warn("NS notify watch: failed to add watch (%s)",
			  safe_strerror(errno));
	}
	zebra_netns_notify_current = thread_add_read(
		zebrad.master, zebra_ns_notify_read, NULL, fd_monitor, NULL);
}

void zebra_ns_notify_close(void)
{
	if (zebra_netns_notify_current == NULL)
		return;

	int fd = 0;

	if (zebra_netns_notify_current->u.fd > 0)
		fd = zebra_netns_notify_current->u.fd;
	thread_cancel(zebra_netns_notify_current);
	/* auto-removal of inotify items */
	if (fd > 0)
		close(fd);
}

#else
void zebra_ns_notify_parse(void)
{
}

void zebra_ns_notify_init(void)
{
}

void zebra_ns_notify_close(void)
{
}
#endif /* !HAVE_NETLINK */
Commit	Line	Data
e27dec3c PG	1	/*
	2	* Zebra NS collector and notifier for Network NameSpaces
	3	* Copyright (C) 2017 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	#ifdef HAVE_NETLINK
	23	#ifdef HAVE_NETNS
	24	#undef _GNU_SOURCE
	25	#define _GNU_SOURCE
	26
	27	#include <sched.h>
	28	#endif
	29	#include <dirent.h>
	30	#include <sys/inotify.h>
	31	#include <sys/stat.h>
	32
	33	#include "thread.h"
	34	#include "ns.h"
	35	#include "command.h"
	36	#include "memory.h"
174482ef	37	#include "lib_errors.h"
e27dec3c PG	38
	39	#include "zserv.h"
	40	#include "zebra_memory.h"
	41	#endif /* defined(HAVE_NETLINK) */
	42
	43	#include "zebra_netns_notify.h"
	44	#include "zebra_netns_id.h"
	45
	46	#ifdef HAVE_NETLINK
	47
	48	/* upon creation of folder under /var/run/netns,
	49	* wait that netns context is bound to
	50	* that folder 10 seconds
	51	*/
	52	#define ZEBRA_NS_POLLING_INTERVAL_MSEC 1000
	53	#define ZEBRA_NS_POLLING_MAX_RETRIES 200
	54
	55	DEFINE_MTYPE_STATIC(ZEBRA, NETNS_MISC, "ZebraNetNSInfo")
	56	static struct thread *zebra_netns_notify_current;
	57
	58	struct zebra_netns_info {
	59	const char *netnspath;
	60	unsigned int retries;
	61	};
	62
	63	static int zebra_ns_ready_read(struct thread *t);
	64	static void zebra_ns_notify_create_context_from_entry_name(const char *name);
	65	static int zebra_ns_continue_read(struct zebra_netns_info *zns_info,
	66	int stop_retry);
	67	static int zebra_ns_notify_read(struct thread *t);
	68
	69	static void zebra_ns_notify_create_context_from_entry_name(const char *name)
	70	{
	71	char *netnspath = ns_netns_pathname(NULL, name);
	72	struct vrf *vrf;
	73	int ret;
03aff2d8	74	ns_id_t ns_id, ns_id_external;
e27dec3c PG	75
	76	if (netnspath == NULL)
	77	return;
	78
01b9e3fd DL	79	frr_elevate_privs(&zserv_privs) {
	80	ns_id = zebra_ns_id_get(netnspath);
	81	}
85a0edca PG	82	if (ns_id == NS_UNKNOWN)
85a0edca PG	83	return;
03aff2d8	84	ns_id_external = ns_map_nsid_with_external(ns_id, true);
b7b816df	85	/* if VRF with NS ID already present */
03aff2d8	86	vrf = vrf_lookup_by_id((vrf_id_t)ns_id_external);
b7b816df	87	if (vrf) {
996c9314 LB	88	zlog_warn(
	89	"NS notify : same NSID used by VRF %s. Ignore NS %s creation",
	90	vrf->name, netnspath);
b7b816df PG	91	return;
	92	}
	93	if (vrf_handler_create(NULL, name, &vrf) != CMD_SUCCESS) {
	94	zlog_warn("NS notify : failed to create VRF %s", name);
03aff2d8	95	ns_map_nsid_with_external(ns_id, false);
b7b816df PG	96	return;
b7b816df PG	97	}
01b9e3fd DL	98	frr_elevate_privs(&zserv_privs) {
	99	ret = vrf_netns_handler_create(NULL, vrf, netnspath,
	100	ns_id_external, ns_id);
	101	}
e27dec3c PG	102	if (ret != CMD_SUCCESS) {
e27dec3c PG	103	zlog_warn("NS notify : failed to create NS %s", netnspath);
03aff2d8	104	ns_map_nsid_with_external(ns_id, false);
73899a2f	105	vrf_delete(vrf);
e27dec3c PG	106	return;
e27dec3c PG	107	}
996c9314	108	zlog_info("NS notify : created VRF %s NS %s", name, netnspath);
e27dec3c PG	109	}
	110
	111	static int zebra_ns_continue_read(struct zebra_netns_info *zns_info,
	112	int stop_retry)
	113	{
	114	void ns_path_ptr = (void )zns_info->netnspath;
	115
	116	if (stop_retry) {
	117	XFREE(MTYPE_NETNS_MISC, ns_path_ptr);
	118	XFREE(MTYPE_NETNS_MISC, zns_info);
	119	return 0;
	120	}
	121	thread_add_timer_msec(zebrad.master, zebra_ns_ready_read,
996c9314 LB	122	(void *)zns_info, ZEBRA_NS_POLLING_INTERVAL_MSEC,
996c9314 LB	123	NULL);
e27dec3c PG	124	return 0;
	125	}
	126
0c902ba5 PG	127	static int zebra_ns_delete(char *name)
	128	{
	129	struct vrf *vrf = vrf_lookup_by_name(name);
	130	struct ns *ns;
	131
	132	if (!vrf) {
	133	zlog_warn(
	134	"NS notify : no VRF found using NS %s",
	135	name);
	136	return 0;
	137	}
	138	/* Clear configured flag and invoke delete. */
	139	UNSET_FLAG(vrf->status, VRF_CONFIGURED);
	140	ns = (struct ns *)vrf->ns_ctxt;
	141	/* the deletion order is the same
	142	* as the one used when siging signal is received
	143	*/
	144	vrf_delete(vrf);
	145	if (ns)
	146	ns_delete(ns);
	147
	148	zlog_info("NS notify : deleted VRF %s", name);
	149	return 0;
	150	}
	151
	152
e27dec3c PG	153	static int zebra_ns_ready_read(struct thread *t)
	154	{
	155	struct zebra_netns_info *zns_info = THREAD_ARG(t);
	156	const char *netnspath;
	157	int err, stop_retry = 0;
	158
	159	if (!zns_info)
	160	return 0;
	161	if (!zns_info->netnspath) {
	162	XFREE(MTYPE_NETNS_MISC, zns_info);
	163	return 0;
	164	}
	165	netnspath = zns_info->netnspath;
	166	if (--zns_info->retries == 0)
	167	stop_retry = 1;
01b9e3fd DL	168	frr_elevate_privs(&zserv_privs) {
	169	err = ns_switch_to_netns(netnspath);
	170	}
e27dec3c PG	171	if (err < 0)
	172	return zebra_ns_continue_read(zns_info, stop_retry);
	173
	174	/* go back to default ns */
01b9e3fd DL	175	frr_elevate_privs(&zserv_privs) {
	176	err = ns_switchback_to_initial();
	177	}
e27dec3c PG	178	if (err < 0)
	179	return zebra_ns_continue_read(zns_info, stop_retry);
	180
	181	/* success : close fd and create zns context */
	182	zebra_ns_notify_create_context_from_entry_name(basename(netnspath));
	183	return zebra_ns_continue_read(zns_info, 1);
	184	}
	185
	186	static int zebra_ns_notify_read(struct thread *t)
	187	{
	188	int fd_monitor = THREAD_FD(t);
	189	struct inotify_event *event;
	190	char buf[BUFSIZ];
	191	ssize_t len;
	192
996c9314 LB	193	zebra_netns_notify_current = thread_add_read(
996c9314 LB	194	zebrad.master, zebra_ns_notify_read, NULL, fd_monitor, NULL);
e27dec3c PG	195	len = read(fd_monitor, buf, sizeof(buf));
	196	if (len < 0) {
	197	zlog_warn("NS notify read: failed to read (%s)",
	198	safe_strerror(errno));
	199	return 0;
	200	}
996c9314 LB	201	for (event = (struct inotify_event )buf; (char )event < &buf[len];
	202	event = (struct inotify_event )((char )event + sizeof(*event)
	203	+ event->len)) {
e27dec3c PG	204	char *netnspath;
	205	struct zebra_netns_info *netnsinfo;
	206
0c902ba5	207	if (!(event->mask & (IN_CREATE \| IN_DELETE)))
e27dec3c	208	continue;
b00592cb	209	if (event->mask & IN_DELETE)
0c902ba5	210	return zebra_ns_delete(event->name);
45981fda	211
	212	if (offsetof(struct inotify_event, name) + event->len
	213	>= sizeof(buf)) {
32ac96b2	214	zlog_err("NS notify read: buffer underflow");
	215	break;
	216	}
b6312ad1	217
	218	if (strnlen(event->name, event->len) == event->len) {
	219	zlog_err("NS notify error: bad event name");
	220	break;
	221	}
	222
e27dec3c PG	223	netnspath = ns_netns_pathname(NULL, event->name);
	224	if (!netnspath)
	225	continue;
	226	netnspath = XSTRDUP(MTYPE_NETNS_MISC, netnspath);
	227	netnsinfo = XCALLOC(MTYPE_NETNS_MISC,
	228	sizeof(struct zebra_netns_info));
	229	netnsinfo->retries = ZEBRA_NS_POLLING_MAX_RETRIES;
	230	netnsinfo->netnspath = netnspath;
	231	thread_add_timer_msec(zebrad.master, zebra_ns_ready_read,
996c9314	232	(void *)netnsinfo, 0, NULL);
e27dec3c PG	233	}
	234	return 0;
	235	}
	236
	237	void zebra_ns_notify_parse(void)
	238	{
	239	struct dirent *dent;
	240	DIR *srcdir = opendir(NS_RUN_DIR);
	241
	242	if (srcdir == NULL) {
	243	zlog_warn("NS parsing init: failed to parse %s", NS_RUN_DIR);
	244	return;
	245	}
	246	while ((dent = readdir(srcdir)) != NULL) {
	247	struct stat st;
	248
	249	if (strcmp(dent->d_name, ".") == 0
996c9314	250	\|\| strcmp(dent->d_name, "..") == 0)
e27dec3c PG	251	continue;
	252	if (fstatat(dirfd(srcdir), dent->d_name, &st, 0) < 0) {
	253	zlog_warn("NS parsing init: failed to parse entry %s",
	254	dent->d_name);
	255	continue;
	256	}
	257	if (S_ISDIR(st.st_mode)) {
	258	zlog_warn("NS parsing init: %s is not a NS",
	259	dent->d_name);
	260	continue;
	261	}
	262	zebra_ns_notify_create_context_from_entry_name(dent->d_name);
	263	}
	264	closedir(srcdir);
	265	}
	266
	267	void zebra_ns_notify_init(void)
	268	{
	269	int fd_monitor;
	270
	271	zebra_netns_notify_current = NULL;
	272	fd_monitor = inotify_init();
	273	if (fd_monitor < 0) {
	274	zlog_warn("NS notify init: failed to initialize inotify (%s)",
	275	safe_strerror(errno));
	276	}
0c902ba5 PG	277	if (inotify_add_watch(fd_monitor, NS_RUN_DIR,
0c902ba5 PG	278	IN_CREATE \| IN_DELETE) < 0) {
e27dec3c PG	279	zlog_warn("NS notify watch: failed to add watch (%s)",
	280	safe_strerror(errno));
	281	}
996c9314 LB	282	zebra_netns_notify_current = thread_add_read(
996c9314 LB	283	zebrad.master, zebra_ns_notify_read, NULL, fd_monitor, NULL);
e27dec3c PG	284	}
	285
	286	void zebra_ns_notify_close(void)
	287	{
	288	if (zebra_netns_notify_current == NULL)
	289	return;
	290
	291	int fd = 0;
	292
	293	if (zebra_netns_notify_current->u.fd > 0)
	294	fd = zebra_netns_notify_current->u.fd;
	295	thread_cancel(zebra_netns_notify_current);
	296	/* auto-removal of inotify items */
	297	if (fd > 0)
	298	close(fd);
	299	}
	300
	301	#else
	302	void zebra_ns_notify_parse(void)
	303	{
	304	}
	305
	306	void zebra_ns_notify_init(void)
	307	{
	308	}
	309
	310	void zebra_ns_notify_close(void)
	311	{
	312	}
	313	#endif /* !HAVE_NETLINK */