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/*
* 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"
#include "zebra_errors.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_debug(
"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) {
flog_warn(EC_ZEBRA_NS_VRF_CREATION_FAILED,
"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) {
flog_warn(EC_ZEBRA_NS_VRF_CREATION_FAILED,
"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) {
flog_warn(EC_ZEBRA_NS_DELETION_FAILED_NO_VRF,
"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_notify_self_identify(struct stat *netst)
{
char net_path[64];
int netns;
sprintf(net_path, "/proc/self/ns/net");
netns = open(net_path, O_RDONLY);
if (netns < 0)
return -1;
if (fstat(netns, netst) < 0) {
close(netns);
return -1;
}
close(netns);
return 0;
}
static bool zebra_ns_notify_is_default_netns(const char *name)
{
struct stat default_netns_stat;
struct stat st;
char netnspath[64];
if (zebra_ns_notify_self_identify(&default_netns_stat))
return false;
memset(&st, 0, sizeof(struct stat));
snprintf(netnspath, 64, "%s/%s", NS_RUN_DIR, name);
/* compare with local stat */
if (stat(netnspath, &st) == 0 &&
(st.st_dev == default_netns_stat.st_dev) &&
(st.st_ino == default_netns_stat.st_ino))
return true;
return false;
}
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);
if (zebra_ns_notify_is_default_netns(basename(netnspath))) {
zlog_warn(
"NS notify : NS %s is default VRF."
" Updating VRF Name", basename(netnspath));
vrf_set_default_name(basename(netnspath));
return zebra_ns_continue_read(zns_info, 1);
}
/* 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) {
flog_err_sys(EC_ZEBRA_NS_NOTIFY_READ,
"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)) {
flog_err(EC_ZEBRA_NS_NOTIFY_READ,
"NS notify read: buffer underflow");
break;
}
if (strnlen(event->name, event->len) == event->len) {
flog_err(EC_ZEBRA_NS_NOTIFY_READ,
"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) {
flog_err_sys(EC_LIB_SYSTEM_CALL,
"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) {
flog_err_sys(
EC_LIB_SYSTEM_CALL,
"NS parsing init: failed to parse entry %s",
dent->d_name);
continue;
}
if (S_ISDIR(st.st_mode)) {
zlog_debug("NS parsing init: %s is not a NS",
dent->d_name);
continue;
}
if (zebra_ns_notify_is_default_netns(dent->d_name)) {
zlog_warn(
"NS notify : NS %s is default VRF."
" Updating VRF Name", dent->d_name);
vrf_set_default_name(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) {
flog_err_sys(
EC_LIB_SYSTEM_CALL,
"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) {
flog_err_sys(EC_LIB_SYSTEM_CALL,
"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 */
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