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machined: add logic to query IP addresses of containers

This commit is contained in:
Lennart Poettering 2014-05-18 20:48:53 +09:00
parent 4eaea66423
commit 878cd7e95c
9 changed files with 384 additions and 77 deletions
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8
src/libsystemd/sd-bus/bus-container.c
View File

@ -42,7 +42,7 @@ int bus_container_connect_socket(sd_bus *b) {
if (r < 0)
return r;
r = namespace_open(leader, &pidnsfd, &mntnsfd, &rootfd);
r = namespace_open(leader, &pidnsfd, &mntnsfd, NULL, &rootfd);
if (r < 0)
return r;
@ -61,7 +61,7 @@ int bus_container_connect_socket(sd_bus *b) {
if (child == 0) {
pid_t grandchild;
r = namespace_enter(pidnsfd, mntnsfd, rootfd);
r = namespace_enter(pidnsfd, mntnsfd, -1, rootfd);
if (r < 0)
_exit(255);
@ -140,7 +140,7 @@ int bus_container_connect_kernel(sd_bus *b) {
if (r < 0)
return r;
r = namespace_open(leader, &pidnsfd, &mntnsfd, &rootfd);
r = namespace_open(leader, &pidnsfd, &mntnsfd, NULL, &rootfd);
if (r < 0)
return r;
@ -156,7 +156,7 @@ int bus_container_connect_kernel(sd_bus *b) {
pair[0] = safe_close(pair[0]);
r = namespace_enter(pidnsfd, mntnsfd, rootfd);
r = namespace_enter(pidnsfd, mntnsfd, -1, rootfd);
if (r < 0)
_exit(EXIT_FAILURE);

217
src/machine/machine-dbus.c
View File

@ -22,11 +22,15 @@
#include <errno.h>
#include <string.h>
#include <sys/capability.h>
#include <arpa/inet.h>
#include "sd-rtnl.h"
#include "bus-util.h"
#include "bus-label.h"
#include "strv.h"
#include "machine.h"
#include "rtnl-util.h"
#include "bus-errors.h"
static int property_get_id(
sd_bus *bus,
@ -79,7 +83,7 @@ static int property_get_state(
static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_class, machine_class, MachineClass);
static int method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
int bus_machine_method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
Machine *m = userdata;
int r;
@ -94,7 +98,7 @@ static int method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata
return sd_bus_reply_method_return(message, NULL);
}
static int method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
int bus_machine_method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
Machine *m = userdata;
const char *swho;
int32_t signo;
@ -127,6 +131,208 @@ static int method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_
return sd_bus_reply_method_return(message, NULL);
}
int bus_machine_method_get_addresses(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
_cleanup_close_pair_ int pair[2] = { -1, -1 };
_cleanup_free_ char *us = NULL, *them = NULL;
_cleanup_close_ int netns_fd = -1;
Machine *m = userdata;
const char *p;
siginfo_t si;
pid_t child;
int r;
assert(bus);
assert(message);
assert(m);
r = readlink_malloc("/proc/self/ns/net", &us);
if (r < 0)
return sd_bus_error_set_errno(error, r);
p = procfs_file_alloca(m->leader, "ns/net");
r = readlink_malloc(p, &them);
if (r < 0)
return sd_bus_error_set_errno(error, r);
if (streq(us, them))
return sd_bus_error_setf(error, BUS_ERROR_NO_PRIVATE_NETWORKING, "Machine %s does not use private networking", m->name);
r = namespace_open(m->leader, NULL, NULL, &netns_fd, NULL);
if (r < 0)
return sd_bus_error_set_errno(error, r);
if (socketpair(AF_UNIX, SOCK_SEQPACKET, 0, pair) < 0)
return sd_bus_error_set_errno(error, -errno);
child = fork();
if (child < 0)
return sd_bus_error_set_errno(error, -errno);
if (child == 0) {
_cleanup_rtnl_message_unref_ sd_rtnl_message *req = NULL, *resp = NULL;
_cleanup_rtnl_unref_ sd_rtnl *rtnl = NULL;
sd_rtnl_message *addr;
pair[0] = safe_close(pair[0]);
r = namespace_enter(-1, -1, netns_fd, -1);
if (r < 0)
_exit(EXIT_FAILURE);
r = sd_rtnl_open(&rtnl, 0);
if (r < 0)
_exit(EXIT_FAILURE);
r = sd_rtnl_message_new_addr(rtnl, &req, RTM_GETADDR, 0, AF_UNSPEC);
if (r < 0)
_exit(EXIT_FAILURE);
r = sd_rtnl_message_request_dump(req, true);
if (r < 0)
_exit(EXIT_FAILURE);
r = sd_rtnl_call(rtnl, req, 0, &resp);
if (r < 0)
_exit(EXIT_FAILURE);
for (addr = resp; addr; addr = sd_rtnl_message_next(addr)) {
uint16_t type;
unsigned char family;
union {
struct in_addr in;
struct in6_addr in6;
} in_addr;
struct iovec iov[2];
r = sd_rtnl_message_get_type(addr, &type);
if (r < 0)
_exit(EXIT_FAILURE);
if (type != RTM_NEWADDR)
continue;
r = sd_rtnl_message_addr_get_family(addr, &family);
if (r < 0)
_exit(EXIT_FAILURE);
iov[0] = (struct iovec) { .iov_base = &family, .iov_len = sizeof(family) };
switch (family) {
case AF_INET:
r = sd_rtnl_message_read_in_addr(addr, IFA_LOCAL, &in_addr.in);
if (r < 0)
_exit(EXIT_FAILURE);
if (in_addr.in.s_addr == htobe32(INADDR_LOOPBACK))
continue;
iov[1] = (struct iovec) { .iov_base = &in_addr.in, .iov_len = sizeof(in_addr.in) };
break;
case AF_INET6:
r = sd_rtnl_message_read_in6_addr(addr, IFA_ADDRESS, &in_addr.in6);
if (r < 0)
_exit(EXIT_FAILURE);
if (IN6_IS_ADDR_LOOPBACK(&in_addr.in6))
continue;
iov[1] = (struct iovec) { .iov_base = &in_addr.in6, .iov_len = sizeof(in_addr.in6) };
break;
default:
continue;
}
r = writev(pair[1], iov, 2);
if (r < 0)
_exit(EXIT_FAILURE);
}
_exit(EXIT_SUCCESS);
}
pair[1] = safe_close(pair[1]);
r = sd_bus_message_new_method_return(message, &reply);
if (r < 0)
return sd_bus_error_set_errno(error, r);
r = sd_bus_message_open_container(reply, 'a', "(yay)");
if (r < 0)
return sd_bus_error_set_errno(error, r);
for (;;) {
unsigned char family;
ssize_t n;
union {
struct in_addr in;
struct in6_addr in6;
} in_addr;
struct iovec iov[2];
struct msghdr mh = {
.msg_iov = iov,
.msg_iovlen = 2,
};
iov[0] = (struct iovec) { .iov_base = &family, .iov_len = sizeof(family) };
iov[1] = (struct iovec) { .iov_base = &in_addr, .iov_len = sizeof(in_addr) };
n = recvmsg(pair[0], &mh, 0);
if (n < 0)
return sd_bus_error_set_errno(error, -errno);
if ((size_t) n < sizeof(family))
break;
r = sd_bus_message_open_container(reply, 'r', "yay");
if (r < 0)
return sd_bus_error_set_errno(error, r);
r = sd_bus_message_append(reply, "y", family);
if (r < 0)
return sd_bus_error_set_errno(error, r);
switch (family) {
case AF_INET:
if (n != sizeof(struct in_addr) + sizeof(family))
return sd_bus_error_set_errno(error, EIO);
r = sd_bus_message_append_array(reply, 'y', &in_addr.in, sizeof(in_addr.in));
break;
case AF_INET6:
if (n != sizeof(struct in6_addr) + sizeof(family))
return sd_bus_error_set_errno(error, EIO);
r = sd_bus_message_append_array(reply, 'y', &in_addr.in6, sizeof(in_addr.in6));
break;
}
if (r < 0)
return sd_bus_error_set_errno(error, r);
r = sd_bus_message_close_container(reply);
if (r < 0)
return sd_bus_error_set_errno(error, r);
}
r = wait_for_terminate(child, &si);
if (r < 0)
return sd_bus_error_set_errno(error, r);
if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
return sd_bus_error_set_errno(error, EIO);
r = sd_bus_message_close_container(reply);
if (r < 0)
return sd_bus_error_set_errno(error, r);
return sd_bus_send(bus, reply, NULL);
}
const sd_bus_vtable machine_vtable[] = {
SD_BUS_VTABLE_START(0),
SD_BUS_PROPERTY("Name", "s", NULL, offsetof(Machine, name), SD_BUS_VTABLE_PROPERTY_CONST),
@ -139,9 +345,10 @@ const sd_bus_vtable machine_vtable[] = {
SD_BUS_PROPERTY("Class", "s", property_get_class, offsetof(Machine, class), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("RootDirectory", "s", NULL, offsetof(Machine, root_directory), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("State", "s", property_get_state, 0, 0),
SD_BUS_METHOD("Terminate", NULL, NULL, method_terminate, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
SD_BUS_METHOD("Kill", "si", NULL, method_kill, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
SD_BUS_VTABLE_END
SD_BUS_METHOD("Terminate", NULL, NULL, bus_machine_method_terminate, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
SD_BUS_METHOD("Kill", "si", NULL, bus_machine_method_kill, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
SD_BUS_METHOD("GetAddresses", NULL, "a(yay)", bus_machine_method_get_addresses, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_VTABLE_END
};
int machine_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error) {

4
src/machine/machine.h
View File

@ -96,6 +96,10 @@ char *machine_bus_path(Machine *s);
int machine_object_find(sd_bus *bus, const char *path, const char *interface, void *userdata, void **found, sd_bus_error *error);
int machine_node_enumerator(sd_bus *bus, const char *path, void *userdata, char ***nodes, sd_bus_error *error);
int bus_machine_method_terminate(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_machine_method_kill(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_machine_method_get_addresses(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error);
int machine_send_signal(Machine *m, bool new_machine);
int machine_send_create_reply(Machine *m, sd_bus_error *error);

75
src/machine/machinectl.c
View File

@ -27,6 +27,8 @@
#include <pwd.h>
#include <locale.h>
#include <fcntl.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include "sd-bus.h"
#include "log.h"
@ -165,6 +167,63 @@ static int show_unit_cgroup(sd_bus *bus, const char *unit, pid_t leader) {
return 0;
}
static int print_addresses(sd_bus *bus, const char *name, const char *prefix, const char *prefix2) {
_cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
int r;
assert(bus);
assert(name);
assert(prefix);
assert(prefix2);
r = sd_bus_call_method(bus,
"org.freedesktop.machine1",
"/org/freedesktop/machine1",
"org.freedesktop.machine1.Manager",
"GetMachineAddresses",
NULL,
&reply,
"s", name);
if (r < 0)
return r;
r = sd_bus_message_enter_container(reply, 'a', "(yay)");
if (r < 0)
return bus_log_parse_error(r);
while ((r = sd_bus_message_enter_container(reply, 'r', "yay")) > 0) {
unsigned char family;
const void *a;
size_t sz;
char buffer[MAX(INET6_ADDRSTRLEN, INET_ADDRSTRLEN)];
r = sd_bus_message_read(reply, "y", &family);
if (r < 0)
return bus_log_parse_error(r);
r = sd_bus_message_read_array(reply, 'y', &a, &sz);
if (r < 0)
return bus_log_parse_error(r);
printf("%s%s\n", prefix, inet_ntop(family, a, buffer, sizeof(buffer)));
r = sd_bus_message_exit_container(reply);
if (r < 0)
return bus_log_parse_error(r);
if (prefix != prefix2)
prefix = prefix2;
}
if (r < 0)
return bus_log_parse_error(r);
r = sd_bus_message_exit_container(reply);
if (r < 0)
return bus_log_parse_error(r);
return 0;
}
typedef struct MachineStatusInfo {
char *name;
sd_id128_t id;
@ -221,6 +280,10 @@ static void print_machine_status_info(sd_bus *bus, MachineStatusInfo *i) {
if (i->root_directory)
printf("\t Root: %s\n", i->root_directory);
print_addresses(bus, i->name,
"\t Address: ",
"\t ");
if (i->unit) {
printf("\t Unit: %s\n", i->unit);
show_unit_cgroup(bus, i->unit, i->leader);
@ -427,7 +490,7 @@ static int openpt_in_namespace(pid_t pid, int flags) {
pid_t child;
siginfo_t si;
r = namespace_open(pid, &pidnsfd, &mntnsfd, &rootfd);
r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &rootfd);
if (r < 0)
return r;
@ -441,7 +504,7 @@ static int openpt_in_namespace(pid_t pid, int flags) {
if (child == 0) {
pair[0] = safe_close(pair[0]);
r = namespace_enter(pidnsfd, mntnsfd, rootfd);
r = namespace_enter(pidnsfd, mntnsfd, -1, rootfd);
if (r < 0)
_exit(EXIT_FAILURE);
@ -466,10 +529,10 @@ static int openpt_in_namespace(pid_t pid, int flags) {
pair[1] = safe_close(pair[1]);
r = wait_for_terminate(child, &si);
if (r < 0 || si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS) {
return r < 0 ? r : -EIO;
}
if (r < 0)
return r;
if (si.si_code != CLD_EXITED || si.si_status != EXIT_SUCCESS)
return -EIO;
if (recvmsg(pair[0], &mh, MSG_NOSIGNAL|MSG_CMSG_CLOEXEC) < 0)
return -errno;

45
src/machine/machined-dbus.c
View File

@ -27,7 +27,6 @@
#include "sd-id128.h"
#include "sd-messages.h"
#include "strv.h"
#include "mkdir.h"
#include "path-util.h"
@ -343,50 +342,49 @@ static int method_terminate_machine(sd_bus *bus, sd_bus_message *message, void *
if (!machine)
return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_MACHINE, "No machine '%s' known", name);
r = machine_stop(machine);
if (r < 0)
return sd_bus_error_set_errno(error, r);
return sd_bus_reply_method_return(message, NULL);
return bus_machine_method_terminate(bus, message, machine, error);
}
static int method_kill_machine(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
Manager *m = userdata;
Machine *machine;
const char *name;
const char *swho;
int32_t signo;
KillWho who;
int r;
assert(bus);
assert(message);
assert(m);
r = sd_bus_message_read(message, "ssi", &name, &swho, &signo);
r = sd_bus_message_read(message, "s", &name);
if (r < 0)
return sd_bus_error_set_errno(error, r);
if (isempty(swho))
who = KILL_ALL;
else {
who = kill_who_from_string(swho);
if (who < 0)
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid kill parameter '%s'", swho);
}
if (signo <= 0 || signo >= _NSIG)
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid signal %i", signo);
machine = hashmap_get(m->machines, name);
if (!machine)
return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_MACHINE, "No machine '%s' known", name);
r = machine_kill(machine, who, signo);
return bus_machine_method_kill(bus, message, machine, error);
}
static int method_get_machine_addresses(sd_bus *bus, sd_bus_message *message, void *userdata, sd_bus_error *error) {
Manager *m = userdata;
Machine *machine;
const char *name;
int r;
assert(bus);
assert(message);
assert(m);
r = sd_bus_message_read(message, "s", &name);
if (r < 0)
return sd_bus_error_set_errno(error, r);
return sd_bus_reply_method_return(message, NULL);
machine = hashmap_get(m->machines, name);
if (!machine)
return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_MACHINE, "No machine '%s' known", name);
return bus_machine_method_get_addresses(bus, message, machine, error);
}
const sd_bus_vtable manager_vtable[] = {
@ -398,6 +396,7 @@ const sd_bus_vtable manager_vtable[] = {
SD_BUS_METHOD("RegisterMachine", "sayssus", "o", method_register_machine, 0),
SD_BUS_METHOD("KillMachine", "ssi", NULL, method_kill_machine, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
SD_BUS_METHOD("TerminateMachine", "s", NULL, method_terminate_machine, SD_BUS_VTABLE_CAPABILITY(CAP_KILL)),
SD_BUS_METHOD("GetMachineAddresses", "s", "a(yay)", method_get_machine_addresses, SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_SIGNAL("MachineNew", "so", 0),
SD_BUS_SIGNAL("MachineRemoved", "so", 0),
SD_BUS_VTABLE_END

1
src/shared/bus-errors.h
View File

@ -42,6 +42,7 @@
#define BUS_ERROR_NO_SUCH_MACHINE "org.freedesktop.machine1.NoSuchMachine"
#define BUS_ERROR_NO_MACHINE_FOR_PID "org.freedesktop.machine1.NoMachineForPID"
#define BUS_ERROR_MACHINE_EXISTS "org.freedesktop.machine1.MachineExists"
#define BUS_ERROR_NO_PRIVATE_NETWORKING "org.freedesktop.machine1.NoPrivateNetworking"
#define BUS_ERROR_NO_SUCH_SESSION "org.freedesktop.login1.NoSuchSession"
#define BUS_ERROR_NO_SESSION_FOR_PID "org.freedesktop.login1.NoSessionForPID"

4
src/shared/logs-show.c
View File

@ -1158,7 +1158,7 @@ static int get_boot_id_for_machine(const char *machine, sd_id128_t *boot_id) {
if (r < 0)
return r;
r = namespace_open(pid, &pidnsfd, &mntnsfd, &rootfd);
r = namespace_open(pid, &pidnsfd, &mntnsfd, NULL, &rootfd);
if (r < 0)
return r;
@ -1174,7 +1174,7 @@ static int get_boot_id_for_machine(const char *machine, sd_id128_t *boot_id) {
pair[0] = safe_close(pair[0]);
r = namespace_enter(pidnsfd, mntnsfd, rootfd);
r = namespace_enter(pidnsfd, mntnsfd, -1, rootfd);
if (r < 0)
_exit(EXIT_FAILURE);

103
src/shared/util.c
View File

@ -6091,60 +6091,93 @@ int container_get_leader(const char *machine, pid_t *pid) {
return 0;
}
int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *root_fd) {
_cleanup_close_ int pidnsfd = -1, mntnsfd = -1;
const char *pidns, *mntns, *root;
int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *root_fd) {
_cleanup_close_ int pidnsfd = -1, mntnsfd = -1, netnsfd = -1;
int rfd;
assert(pid >= 0);
assert(pidns_fd);
assert(mntns_fd);
assert(root_fd);
mntns = procfs_file_alloca(pid, "ns/mnt");
mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (mntnsfd < 0)
return -errno;
if (mntns_fd) {
const char *mntns;
pidns = procfs_file_alloca(pid, "ns/pid");
pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (pidnsfd < 0)
return -errno;
mntns = procfs_file_alloca(pid, "ns/mnt");
mntnsfd = open(mntns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (mntnsfd < 0)
return -errno;
}
root = procfs_file_alloca(pid, "root");
rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
if (rfd < 0)
return -errno;
if (pidns_fd) {
const char *pidns;
*pidns_fd = pidnsfd;
*mntns_fd = mntnsfd;
*root_fd = rfd;
pidnsfd = -1;
mntnsfd = -1;
pidns = procfs_file_alloca(pid, "ns/pid");
pidnsfd = open(pidns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (pidnsfd < 0)
return -errno;
}
if (netns_fd) {
const char *netns;
netns = procfs_file_alloca(pid, "ns/net");
netnsfd = open(netns, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (netnsfd < 0)
return -errno;
}
if (root_fd) {
const char *root;
root = procfs_file_alloca(pid, "root");
rfd = open(root, O_RDONLY|O_NOCTTY|O_CLOEXEC|O_DIRECTORY);
if (rfd < 0)
return -errno;
}
if (pidns_fd)
*pidns_fd = pidnsfd;
if (mntns_fd)
*mntns_fd = mntnsfd;
if (netns_fd)
*netns_fd = netnsfd;
if (root_fd)
*root_fd = rfd;
pidnsfd = mntnsfd = netnsfd = -1;
return 0;
}
int namespace_enter(int pidns_fd, int mntns_fd, int root_fd) {
assert(pidns_fd >= 0);
assert(mntns_fd >= 0);
assert(root_fd >= 0);
int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int root_fd) {
if (setns(pidns_fd, CLONE_NEWPID) < 0)
return -errno;
if (pidns_fd >= 0)
if (setns(pidns_fd, CLONE_NEWPID) < 0)
return -errno;
if (setns(mntns_fd, CLONE_NEWNS) < 0)
return -errno;
if (mntns_fd >= 0)
if (setns(mntns_fd, CLONE_NEWNS) < 0)
return -errno;
if (fchdir(root_fd) < 0)
return -errno;
if (netns_fd >= 0)
if (setns(netns_fd, CLONE_NEWNET) < 0)
return -errno;
if (chroot(".") < 0)
return -errno;
if (root_fd >= 0) {
if (fchdir(root_fd) < 0)
return -errno;
if (chroot(".") < 0)
return -errno;
}
if (setresgid(0, 0, 0) < 0)
return -errno;
if (setgroups(0, NULL) < 0)
return -errno;
if (setresuid(0, 0, 0) < 0)
return -errno;

4
src/shared/util.h
View File

@ -910,8 +910,8 @@ int parse_proc_cmdline(int (*parse_word)(const char *key, const char *value));
int container_get_leader(const char *machine, pid_t *pid);
int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *root_fd);
int namespace_enter(int pidns_fd, int mntns_fd, int root_fd);
int namespace_open(pid_t pid, int *pidns_fd, int *mntns_fd, int *netns_fd, int *root_fd);
int namespace_enter(int pidns_fd, int mntns_fd, int netns_fd, int root_fd);
bool pid_is_alive(pid_t pid);
bool pid_is_unwaited(pid_t pid);