add Linux network namespace support for TUN device

Change-Id: Idd0ad8fa9c8e7ba0aeec1b52947598d4d297b620
This commit is contained in:
Andreas Schultz 2018-10-05 13:58:45 +01:00 committed by Pau Espin Pedrol
parent b283c32027
commit b629240a35
7 changed files with 294 additions and 12 deletions

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@ -1,10 +1,10 @@
noinst_LIBRARIES = libmisc.a
noinst_HEADERS = gnugetopt.h ippool.h lookup.h syserr.h tun.h in46_addr.h netdev.h gtp-kernel.h util.h
noinst_HEADERS = gnugetopt.h ippool.h lookup.h syserr.h tun.h in46_addr.h netdev.h gtp-kernel.h netns.h util.h
AM_CFLAGS = -O2 -fno-builtin -Wall -DSBINDIR='"$(sbindir)"' -ggdb $(LIBOSMOCORE_CFLAGS)
libmisc_a_SOURCES = getopt1.c getopt.c ippool.c lookup.c tun.c debug.c in46_addr.c netdev.c util.c
libmisc_a_SOURCES = getopt1.c getopt.c ippool.c lookup.c tun.c debug.c in46_addr.c netdev.c netns.c util.c
if ENABLE_GTP_KERNEL
AM_CFLAGS += -DGTP_KERNEL $(LIBGTPNL_CFLAGS)

147
lib/netns.c Normal file
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@ -0,0 +1,147 @@
/*
* Copyright (C) 2014-2017, Travelping GmbH <info@travelping.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#if defined(__linux__)
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifndef _GNU_SOURCE
# define _GNU_SOURCE
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sched.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/socket.h>
#include <sys/mount.h>
#include <sys/param.h>
#include <fcntl.h>
#include <errno.h>
#include "netns.h"
#define NETNS_PATH "/var/run/netns"
static int default_nsfd;
int switch_ns(int nsfd, sigset_t *oldmask)
{
sigset_t intmask;
sigfillset(&intmask);
sigprocmask(SIG_BLOCK, &intmask, oldmask);
return setns(nsfd, CLONE_NEWNET);
}
void restore_ns(sigset_t *oldmask)
{
setns(default_nsfd, CLONE_NEWNET);
sigprocmask(SIG_SETMASK, oldmask, NULL);
}
int open_ns(int nsfd, const char *pathname, int flags)
{
sigset_t intmask, oldmask;
int fd;
int errsv;
sigfillset(&intmask);
sigprocmask(SIG_BLOCK, &intmask, &oldmask);
setns(nsfd, CLONE_NEWNET);
fd = open(pathname, flags);
errsv = errno;
setns(default_nsfd, CLONE_NEWNET);
sigprocmask(SIG_SETMASK, &oldmask, NULL);
errno = errsv;
return fd;
}
int socket_ns(int nsfd, int domain, int type, int protocol)
{
sigset_t intmask, oldmask;
int sk;
int errsv;
sigfillset(&intmask);
sigprocmask(SIG_BLOCK, &intmask, &oldmask);
setns(nsfd, CLONE_NEWNET);
sk = socket(domain, type, protocol);
errsv = errno;
setns(default_nsfd, CLONE_NEWNET);
sigprocmask(SIG_SETMASK, &oldmask, NULL);
errno = errsv;
return sk;
}
void init_netns()
{
if ((default_nsfd = open("/proc/self/ns/net", O_RDONLY)) < 0) {
perror("init_netns");
exit(EXIT_FAILURE);
}
}
int get_nsfd(const char *name)
{
int r;
sigset_t intmask, oldmask;
char path[MAXPATHLEN] = NETNS_PATH;
r = mkdir(path, S_IRWXU|S_IRGRP|S_IXGRP|S_IROTH|S_IXOTH);
if (r < 0 && errno != EEXIST)
return r;
snprintf(path, sizeof(path), "%s/%s", NETNS_PATH, name);
r = open(path, O_RDONLY|O_CREAT|O_EXCL, 0);
if (r < 0) {
if (errno == EEXIST)
return open(path, O_RDONLY);
return r;
}
close(r);
sigfillset(&intmask);
sigprocmask(SIG_BLOCK, &intmask, &oldmask);
unshare(CLONE_NEWNET);
mount("/proc/self/ns/net", path, "none", MS_BIND, NULL);
setns(default_nsfd, CLONE_NEWNET);
sigprocmask(SIG_SETMASK, &oldmask, NULL);
return open(path, O_RDONLY);
}
#endif

35
lib/netns.h Normal file
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@ -0,0 +1,35 @@
/*
* Copyright (C) 2014-2017, Travelping GmbH <info@travelping.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#ifndef __NETNS_H
#define __NETNS_H
#if defined(__linux__)
void init_netns(void);
int switch_ns(int nsfd, sigset_t *oldmask);
void restore_ns(sigset_t *oldmask);
int open_ns(int nsfd, const char *pathname, int flags);
int socket_ns(int nsfd, int domain, int type, int protocol);
int get_nsfd(const char *name);
#endif
#endif

View File

@ -72,6 +72,7 @@ const char *gengetopt_args_info_help[] = {
" --ipup=STRING Script to run after link-up",
" --ipdown=STRING Script to run after link-down",
" --tun-device=STRING Name of the local network interface",
" --netns=STRING Network namespace to use",
"\n Mode: pinghost\n generate ICMP payload inside G-PDU without setting up tun interface",
" --pinghost=STRING Ping remote host",
" --pingrate=INT Number of ping req per second (default=`1')",
@ -163,6 +164,7 @@ void clear_given(struct gengetopt_args_info *args_info)
args_info->ipup_given = 0;
args_info->ipdown_given = 0;
args_info->tun_device_given = 0;
args_info->netns_given = 0;
args_info->pinghost_given = 0;
args_info->pingrate_given = 0;
args_info->pingsize_given = 0;
@ -244,6 +246,8 @@ void clear_args(struct gengetopt_args_info *args_info)
args_info->ipdown_orig = NULL;
args_info->tun_device_arg = NULL;
args_info->tun_device_orig = NULL;
args_info->netns_arg = NULL;
args_info->netns_orig = NULL;
args_info->pinghost_arg = NULL;
args_info->pinghost_orig = NULL;
args_info->pingrate_arg = 1;
@ -300,13 +304,14 @@ void init_args_info(struct gengetopt_args_info *args_info)
args_info->ipup_help = gengetopt_args_info_help[35];
args_info->ipdown_help = gengetopt_args_info_help[36];
args_info->tun_device_help = gengetopt_args_info_help[37];
args_info->pinghost_help = gengetopt_args_info_help[39];
args_info->pingrate_help = gengetopt_args_info_help[40];
args_info->pingsize_help = gengetopt_args_info_help[41];
args_info->pingcount_help = gengetopt_args_info_help[42];
args_info->pingquiet_help = gengetopt_args_info_help[43];
args_info->no_tx_gpdu_seq_help = gengetopt_args_info_help[44];
args_info->pdp_type_help = gengetopt_args_info_help[45];
args_info->netns_help = gengetopt_args_info_help[38];
args_info->pinghost_help = gengetopt_args_info_help[40];
args_info->pingrate_help = gengetopt_args_info_help[41];
args_info->pingsize_help = gengetopt_args_info_help[42];
args_info->pingcount_help = gengetopt_args_info_help[43];
args_info->pingquiet_help = gengetopt_args_info_help[44];
args_info->no_tx_gpdu_seq_help = gengetopt_args_info_help[45];
args_info->pdp_type_help = gengetopt_args_info_help[46];
}
@ -432,6 +437,8 @@ static void cmdline_parser_release(struct gengetopt_args_info *args_info)
free_string_field(&(args_info->ipdown_orig));
free_string_field(&(args_info->tun_device_arg));
free_string_field(&(args_info->tun_device_orig));
free_string_field(&(args_info->netns_arg));
free_string_field(&(args_info->netns_orig));
free_string_field(&(args_info->pinghost_arg));
free_string_field(&(args_info->pinghost_orig));
free_string_field(&(args_info->pingrate_orig));
@ -545,6 +552,8 @@ int cmdline_parser_dump(FILE * outfile, struct gengetopt_args_info *args_info)
if (args_info->tun_device_given)
write_into_file(outfile, "tun-device",
args_info->tun_device_orig, 0);
if (args_info->netns_given)
write_into_file(outfile, "netns", args_info->netns_orig, 0);
if (args_info->pinghost_given)
write_into_file(outfile, "pinghost", args_info->pinghost_orig,
0);
@ -709,6 +718,12 @@ cmdline_parser_required2(struct gengetopt_args_info *args_info,
prog_name, (additional_error ? additional_error : ""));
error_occurred = 1;
}
if (args_info->netns_given && !args_info->createif_given) {
fprintf(stderr,
"%s: '--netns' option depends on option 'createif'%s\n",
prog_name, (additional_error ? additional_error : ""));
error_occurred = 1;
}
if (args_info->pingrate_given && !args_info->pinghost_given) {
fprintf(stderr,
"%s: '--pingrate' option depends on option 'pinghost'%s\n",
@ -954,6 +969,7 @@ cmdline_parser_internal(int argc, char **argv,
{"ipup", 1, NULL, 0},
{"ipdown", 1, NULL, 0},
{"tun-device", 1, NULL, 0},
{"netns", 1, NULL, 0},
{"pinghost", 1, NULL, 0},
{"pingrate", 1, NULL, 0},
{"pingsize", 1, NULL, 0},
@ -1493,6 +1509,22 @@ cmdline_parser_internal(int argc, char **argv,
additional_error))
goto failure;
}
/* Network namespace to use. */
else if (strcmp
(long_options[option_index].name,
"netns") == 0) {
args_info->createif_mode_counter += 1;
if (update_arg((void *)&(args_info->netns_arg),
&(args_info->netns_orig),
&(args_info->netns_given),
&(local_args_info.netns_given),
optarg, 0, 0, ARG_STRING,
check_ambiguity, override, 0, 0,
"netns", '-', additional_error))
goto failure;
}
/* Ping remote host. */
else if (strcmp
@ -1609,11 +1641,12 @@ cmdline_parser_internal(int argc, char **argv,
int createif_given[] =
{ args_info->createif_given, args_info->net_given,
args_info->defaultroute_given, args_info->ipup_given,
args_info->ipdown_given, args_info->tun_device_given, -1
args_info->ipdown_given, args_info->tun_device_given,
args_info->netns_given, -1
};
const char *createif_desc[] =
{ "--createif", "--net", "--defaultroute", "--ipup",
"--ipdown", "--tun-device", 0
"--ipdown", "--tun-device", "--netns", 0
};
int pinghost_given[] =
{ args_info->pinghost_given, args_info->pingrate_given,

View File

@ -59,6 +59,7 @@ modeoption "defaultroute" - "Create default route" flag dependon="
modeoption "ipup" - "Script to run after link-up" string dependon="createif" no mode="createif"
modeoption "ipdown" - "Script to run after link-down" string dependon="createif" no mode="createif"
modeoption "tun-device" - "Name of the local network interface" string dependon="createif" no mode="createif"
modeoption "netns" - "Network namespace to use" string dependon="createif" no mode="createif"
modeoption "pinghost" - "Ping remote host" string no mode="pinghost"
modeoption "pingrate" - "Number of ping req per second" int default="1" dependon="pinghost" no mode="pinghost"

View File

@ -242,6 +242,12 @@ extern "C" {
/**< @brief Name of the local network interface original value given at command line. */
const char *tun_device_help;
/**< @brief Name of the local network interface help description. */
char *netns_arg;
/**< @brief Network namespace to use. */
char *netns_orig;
/**< @brief Network namespace to use original value given at command line. */
const char *netns_help;
/**< @brief Network namespace to use help description. */
char *pinghost_arg;
/**< @brief Ping remote host. */
char *pinghost_orig;
@ -355,6 +361,8 @@ extern "C" {
/**< @brief Whether ipdown was given. */
unsigned int tun_device_given;
/**< @brief Whether tun-device was given. */
unsigned int netns_given;
/**< @brief Whether netns was given. */
unsigned int pinghost_given;
/**< @brief Whether pinghost was given. */
unsigned int pingrate_given;

View File

@ -50,6 +50,7 @@
#include "../lib/tun.h"
#include "../lib/ippool.h"
#include "../lib/syserr.h"
#include "../lib/netns.h"
#include "../gtp/pdp.h"
#include "../gtp/gtp.h"
#include "cmdline.h"
@ -81,12 +82,16 @@ struct tun_t *tun = NULL; /* TUN instance */
int maxfd = 0; /* For select() */
int echoversion = 1; /* First try this version */
void *tall_sgsnemu_ctx; /* root talloc ctx */
#if defined(__linux__)
int netns = -1; /* network namespace */
#endif
/* Struct with local versions of gengetopt options */
struct {
int debug; /* Print debug messages */
int createif; /* Create local network interface */
char *tun_dev_name;
char *netns;
struct in46_addr netaddr, destaddr, net; /* Network interface */
size_t prefixlen;
char *ipup, *ipdown; /* Filename of scripts */
@ -294,6 +299,8 @@ static int process_options(int argc, char **argv)
printf("createif: %d\n", args_info.createif_flag);
if (args_info.tun_device_arg)
printf("tun-device: %s\n", args_info.tun_device_arg);
if (args_info.netns_arg)
printf("netns: %s\n", args_info.netns_arg);
if (args_info.ipup_arg)
printf("ipup: %s\n", args_info.ipup_arg);
if (args_info.ipdown_arg)
@ -352,6 +359,8 @@ static int process_options(int argc, char **argv)
printf("createif: %d\n", args_info.createif_flag);
if (args_info.tun_device_arg)
printf("tun-device: %s\n", args_info.tun_device_arg);
if (args_info.netns_arg)
printf("netns: %s\n", args_info.netns_arg);
if (args_info.ipup_arg)
printf("ipup: %s\n", args_info.ipup_arg);
if (args_info.ipdown_arg)
@ -870,6 +879,7 @@ static int process_options(int argc, char **argv)
/* createif */
options.createif = args_info.createif_flag;
options.tun_dev_name = args_info.tun_device_arg;
options.netns = args_info.netns_arg;
/* net */
/* Store net as in_addr net and mask */
@ -1313,10 +1323,23 @@ static int create_ping(void *gsn, struct pdp_t *pdp,
static int delete_context(struct pdp_t *pdp)
{
if (tun && options.ipdown) {
#if defined(__linux__)
sigset_t oldmask;
if (tun && options.ipdown)
if ((options.netns)) {
switch_ns(netns, &oldmask);
}
#endif
tun_runscript(tun, options.ipdown);
#if defined(__linux__)
if ((options.netns)) {
restore_ns(&oldmask);
}
#endif
}
ipdel((struct iphash_t *)pdp->peer[0]);
memset(pdp->peer[0], 0, sizeof(struct iphash_t)); /* To be sure */
@ -1377,6 +1400,9 @@ static int cb_tun_ind(struct tun_t *tun, void *pack, unsigned len)
static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
{
struct in46_addr addr;
#if defined(__linux__)
sigset_t oldmask;
#endif
struct iphash_t *iph = (struct iphash_t *)cbp;
@ -1430,6 +1456,12 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
break;
}
#if defined(__linux__)
if ((options.createif) && (options.netns)) {
switch_ns(netns, &oldmask);
}
#endif
if ((options.createif) && (!options.net.len)) {
size_t prefixlen = 32;
if (addr.len == 16)
@ -1470,6 +1502,12 @@ static int create_pdp_conf(struct pdp_t *pdp, void *cbp, int cause)
free(forwarding);
}
#if defined(__linux__)
if ((options.createif) && (options.netns)) {
restore_ns(&oldmask);
}
#endif
ipset(iph, &addr);
state = 2; /* Connected */
@ -1543,6 +1581,9 @@ int main(int argc, char **argv)
struct timezone tz; /* Used for calculating ping times */
struct timeval tv;
int diff;
#if defined(__linux__)
sigset_t oldmask;
#endif
signal(SIGTERM, signal_handler);
signal(SIGHUP, signal_handler);
@ -1552,6 +1593,10 @@ int main(int argc, char **argv)
msgb_talloc_ctx_init(tall_sgsnemu_ctx, 0);
osmo_init_logging2(tall_sgsnemu_ctx, &log_info);
#if defined(__linux__)
init_netns();
#endif
/* Process options given in configuration file and command line */
if (process_options(argc, argv))
exit(1);
@ -1575,6 +1620,13 @@ int main(int argc, char **argv)
else
gtp_set_cb_data_ind(gsn, encaps_ping);
#if defined(__linux__)
if ((options.createif) && (options.netns)) {
netns = get_nsfd(options.netns);
switch_ns(netns, &oldmask);
}
#endif
if (options.createif) {
printf("Setting up interface\n");
/* Create a tunnel interface */
@ -1600,6 +1652,12 @@ int main(int argc, char **argv)
tun_runscript(tun, options.ipup);
}
#if defined(__linux__)
if ((options.createif) && (options.netns)) {
restore_ns(&oldmask);
}
#endif
/* Initialise hash tables */
memset(&iphash, 0, sizeof(iphash));
memset(&iparr, 0, sizeof(iparr));