hostap/src/common/wpa_ctrl.c
Jouni Malinen b686745c76 Android: Harden wpa_ctrl_open2() against potential race conditions
The Android-specific chmod and chown operations on the client socket
(for communication with wpa_supplicant) did not protect against file
replacement between the bind() and chmod()/chown() calls. If the
directory in which the client socket is created (depends a bit on the
version and platform, but /data/misc/wifi/sockets is commonly used)
allows write access to processes that are different (less privileged)
compared to the process calling wpa_ctrl_open2(), it might be possible
to delete the socket file and replace it with something else (mainly, a
symlink) before the chmod/chown operations occur. This could have
resulted in the owner or permissions of the target of that symlink being
modified.

In general, it would be safest to use a directory which has more limited
write privileges (/data/misc/wifi/sockets normally has 'wifi' group
(AID_WIFI) with write access), but if that cannot be easily changed due
to other constraints, it is better to make wpa_ctrl_open2() less likely
to enable this type of race condition between the operations.

Replace chown() with lchown() (i.e., a version that does not dereference
symlinks) and chmod() with fchmod() on the socket before the bind() call
which is also not going to dereference a symlink (whereas chmod()
would). lchown() is a standard operation, but the fchmod() on the socket
is less so (unspecified behavior in some systems). However, it seems to
work on Linux and in particular, on Android, where this code is
executed.

Signed-off-by: Jouni Malinen <j@w1.fi>
2019-01-06 20:20:20 +02:00

768 lines
18 KiB
C

/*
* wpa_supplicant/hostapd control interface library
* Copyright (c) 2004-2007, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include "includes.h"
#ifdef CONFIG_CTRL_IFACE
#ifdef CONFIG_CTRL_IFACE_UNIX
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/un.h>
#include <unistd.h>
#include <fcntl.h>
#endif /* CONFIG_CTRL_IFACE_UNIX */
#ifdef CONFIG_CTRL_IFACE_UDP_REMOTE
#include <netdb.h>
#endif /* CONFIG_CTRL_IFACE_UDP_REMOTE */
#ifdef ANDROID
#include <dirent.h>
#include <sys/stat.h>
#include <cutils/sockets.h>
#include "private/android_filesystem_config.h"
#endif /* ANDROID */
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
#include <net/if.h>
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
#include "wpa_ctrl.h"
#include "common.h"
#if defined(CONFIG_CTRL_IFACE_UNIX) || defined(CONFIG_CTRL_IFACE_UDP)
#define CTRL_IFACE_SOCKET
#endif /* CONFIG_CTRL_IFACE_UNIX || CONFIG_CTRL_IFACE_UDP */
/**
* struct wpa_ctrl - Internal structure for control interface library
*
* This structure is used by the wpa_supplicant/hostapd control interface
* library to store internal data. Programs using the library should not touch
* this data directly. They can only use the pointer to the data structure as
* an identifier for the control interface connection and use this as one of
* the arguments for most of the control interface library functions.
*/
struct wpa_ctrl {
#ifdef CONFIG_CTRL_IFACE_UDP
int s;
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
struct sockaddr_in6 local;
struct sockaddr_in6 dest;
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
struct sockaddr_in local;
struct sockaddr_in dest;
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
char *cookie;
char *remote_ifname;
char *remote_ip;
#endif /* CONFIG_CTRL_IFACE_UDP */
#ifdef CONFIG_CTRL_IFACE_UNIX
int s;
struct sockaddr_un local;
struct sockaddr_un dest;
#endif /* CONFIG_CTRL_IFACE_UNIX */
#ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
HANDLE pipe;
#endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
};
#ifdef CONFIG_CTRL_IFACE_UNIX
#ifndef CONFIG_CTRL_IFACE_CLIENT_DIR
#define CONFIG_CTRL_IFACE_CLIENT_DIR "/tmp"
#endif /* CONFIG_CTRL_IFACE_CLIENT_DIR */
#ifndef CONFIG_CTRL_IFACE_CLIENT_PREFIX
#define CONFIG_CTRL_IFACE_CLIENT_PREFIX "wpa_ctrl_"
#endif /* CONFIG_CTRL_IFACE_CLIENT_PREFIX */
struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
return wpa_ctrl_open2(ctrl_path, NULL);
}
struct wpa_ctrl * wpa_ctrl_open2(const char *ctrl_path,
const char *cli_path)
{
struct wpa_ctrl *ctrl;
static int counter = 0;
int ret;
size_t res;
int tries = 0;
int flags;
if (ctrl_path == NULL)
return NULL;
ctrl = os_zalloc(sizeof(*ctrl));
if (ctrl == NULL)
return NULL;
ctrl->s = socket(PF_UNIX, SOCK_DGRAM, 0);
if (ctrl->s < 0) {
os_free(ctrl);
return NULL;
}
ctrl->local.sun_family = AF_UNIX;
counter++;
try_again:
if (cli_path && cli_path[0] == '/') {
ret = os_snprintf(ctrl->local.sun_path,
sizeof(ctrl->local.sun_path),
"%s/" CONFIG_CTRL_IFACE_CLIENT_PREFIX "%d-%d",
cli_path, (int) getpid(), counter);
} else {
ret = os_snprintf(ctrl->local.sun_path,
sizeof(ctrl->local.sun_path),
CONFIG_CTRL_IFACE_CLIENT_DIR "/"
CONFIG_CTRL_IFACE_CLIENT_PREFIX "%d-%d",
(int) getpid(), counter);
}
if (os_snprintf_error(sizeof(ctrl->local.sun_path), ret)) {
close(ctrl->s);
os_free(ctrl);
return NULL;
}
tries++;
#ifdef ANDROID
/* Set client socket file permissions so that bind() creates the client
* socket with these permissions and there is no need to try to change
* them with chmod() after bind() which would have potential issues with
* race conditions. These permissions are needed to make sure the server
* side (wpa_supplicant or hostapd) can reply to the control interface
* messages.
*
* The lchown() calls below after bind() are also part of the needed
* operations to allow the response to go through. Those are using the
* no-deference-symlinks version to avoid races. */
fchmod(ctrl->s, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP);
#endif /* ANDROID */
if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
sizeof(ctrl->local)) < 0) {
if (errno == EADDRINUSE && tries < 2) {
/*
* getpid() returns unique identifier for this instance
* of wpa_ctrl, so the existing socket file must have
* been left by unclean termination of an earlier run.
* Remove the file and try again.
*/
unlink(ctrl->local.sun_path);
goto try_again;
}
close(ctrl->s);
os_free(ctrl);
return NULL;
}
#ifdef ANDROID
/* Set group even if we do not have privileges to change owner */
lchown(ctrl->local.sun_path, -1, AID_WIFI);
lchown(ctrl->local.sun_path, AID_SYSTEM, AID_WIFI);
if (os_strncmp(ctrl_path, "@android:", 9) == 0) {
if (socket_local_client_connect(
ctrl->s, ctrl_path + 9,
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_DGRAM) < 0) {
close(ctrl->s);
unlink(ctrl->local.sun_path);
os_free(ctrl);
return NULL;
}
return ctrl;
}
/*
* If the ctrl_path isn't an absolute pathname, assume that
* it's the name of a socket in the Android reserved namespace.
* Otherwise, it's a normal UNIX domain socket appearing in the
* filesystem.
*/
if (*ctrl_path != '/') {
char buf[21];
os_snprintf(buf, sizeof(buf), "wpa_%s", ctrl_path);
if (socket_local_client_connect(
ctrl->s, buf,
ANDROID_SOCKET_NAMESPACE_RESERVED,
SOCK_DGRAM) < 0) {
close(ctrl->s);
unlink(ctrl->local.sun_path);
os_free(ctrl);
return NULL;
}
return ctrl;
}
#endif /* ANDROID */
ctrl->dest.sun_family = AF_UNIX;
if (os_strncmp(ctrl_path, "@abstract:", 10) == 0) {
ctrl->dest.sun_path[0] = '\0';
os_strlcpy(ctrl->dest.sun_path + 1, ctrl_path + 10,
sizeof(ctrl->dest.sun_path) - 1);
} else {
res = os_strlcpy(ctrl->dest.sun_path, ctrl_path,
sizeof(ctrl->dest.sun_path));
if (res >= sizeof(ctrl->dest.sun_path)) {
close(ctrl->s);
os_free(ctrl);
return NULL;
}
}
if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
sizeof(ctrl->dest)) < 0) {
close(ctrl->s);
unlink(ctrl->local.sun_path);
os_free(ctrl);
return NULL;
}
/*
* Make socket non-blocking so that we don't hang forever if
* target dies unexpectedly.
*/
flags = fcntl(ctrl->s, F_GETFL);
if (flags >= 0) {
flags |= O_NONBLOCK;
if (fcntl(ctrl->s, F_SETFL, flags) < 0) {
perror("fcntl(ctrl->s, O_NONBLOCK)");
/* Not fatal, continue on.*/
}
}
return ctrl;
}
void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
if (ctrl == NULL)
return;
unlink(ctrl->local.sun_path);
if (ctrl->s >= 0)
close(ctrl->s);
os_free(ctrl);
}
#ifdef ANDROID
/**
* wpa_ctrl_cleanup() - Delete any local UNIX domain socket files that
* may be left over from clients that were previously connected to
* wpa_supplicant. This keeps these files from being orphaned in the
* event of crashes that prevented them from being removed as part
* of the normal orderly shutdown.
*/
void wpa_ctrl_cleanup(void)
{
DIR *dir;
struct dirent entry;
struct dirent *result;
size_t dirnamelen;
size_t maxcopy;
char pathname[PATH_MAX];
char *namep;
if ((dir = opendir(CONFIG_CTRL_IFACE_CLIENT_DIR)) == NULL)
return;
dirnamelen = (size_t) os_snprintf(pathname, sizeof(pathname), "%s/",
CONFIG_CTRL_IFACE_CLIENT_DIR);
if (dirnamelen >= sizeof(pathname)) {
closedir(dir);
return;
}
namep = pathname + dirnamelen;
maxcopy = PATH_MAX - dirnamelen;
while (readdir_r(dir, &entry, &result) == 0 && result != NULL) {
if (os_strlcpy(namep, entry.d_name, maxcopy) < maxcopy)
unlink(pathname);
}
closedir(dir);
}
#endif /* ANDROID */
#else /* CONFIG_CTRL_IFACE_UNIX */
#ifdef ANDROID
void wpa_ctrl_cleanup(void)
{
}
#endif /* ANDROID */
#endif /* CONFIG_CTRL_IFACE_UNIX */
#ifdef CONFIG_CTRL_IFACE_UDP
struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
struct wpa_ctrl *ctrl;
char buf[128];
size_t len;
#ifdef CONFIG_CTRL_IFACE_UDP_REMOTE
struct hostent *h;
#endif /* CONFIG_CTRL_IFACE_UDP_REMOTE */
ctrl = os_zalloc(sizeof(*ctrl));
if (ctrl == NULL)
return NULL;
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
ctrl->s = socket(PF_INET6, SOCK_DGRAM, 0);
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
ctrl->s = socket(PF_INET, SOCK_DGRAM, 0);
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
if (ctrl->s < 0) {
perror("socket");
os_free(ctrl);
return NULL;
}
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
ctrl->local.sin6_family = AF_INET6;
#ifdef CONFIG_CTRL_IFACE_UDP_REMOTE
ctrl->local.sin6_addr = in6addr_any;
#else /* CONFIG_CTRL_IFACE_UDP_REMOTE */
inet_pton(AF_INET6, "::1", &ctrl->local.sin6_addr);
#endif /* CONFIG_CTRL_IFACE_UDP_REMOTE */
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
ctrl->local.sin_family = AF_INET;
#ifdef CONFIG_CTRL_IFACE_UDP_REMOTE
ctrl->local.sin_addr.s_addr = INADDR_ANY;
#else /* CONFIG_CTRL_IFACE_UDP_REMOTE */
ctrl->local.sin_addr.s_addr = htonl((127 << 24) | 1);
#endif /* CONFIG_CTRL_IFACE_UDP_REMOTE */
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
if (bind(ctrl->s, (struct sockaddr *) &ctrl->local,
sizeof(ctrl->local)) < 0) {
close(ctrl->s);
os_free(ctrl);
return NULL;
}
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
ctrl->dest.sin6_family = AF_INET6;
inet_pton(AF_INET6, "::1", &ctrl->dest.sin6_addr);
ctrl->dest.sin6_port = htons(WPA_CTRL_IFACE_PORT);
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
ctrl->dest.sin_family = AF_INET;
ctrl->dest.sin_addr.s_addr = htonl((127 << 24) | 1);
ctrl->dest.sin_port = htons(WPA_CTRL_IFACE_PORT);
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
#ifdef CONFIG_CTRL_IFACE_UDP_REMOTE
if (ctrl_path) {
char *port, *name;
int port_id;
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
char *scope;
int scope_id = 0;
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
name = os_strdup(ctrl_path);
if (name == NULL) {
close(ctrl->s);
os_free(ctrl);
return NULL;
}
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
port = os_strchr(name, ',');
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
port = os_strchr(name, ':');
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
if (port) {
port_id = atoi(&port[1]);
port[0] = '\0';
} else
port_id = WPA_CTRL_IFACE_PORT;
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
scope = os_strchr(name, '%');
if (scope) {
scope_id = if_nametoindex(&scope[1]);
scope[0] = '\0';
}
h = gethostbyname2(name, AF_INET6);
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
h = gethostbyname(name);
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
ctrl->remote_ip = os_strdup(name);
os_free(name);
if (h == NULL) {
perror("gethostbyname");
close(ctrl->s);
os_free(ctrl->remote_ip);
os_free(ctrl);
return NULL;
}
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
ctrl->dest.sin6_scope_id = scope_id;
ctrl->dest.sin6_port = htons(port_id);
os_memcpy(&ctrl->dest.sin6_addr, h->h_addr, h->h_length);
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
ctrl->dest.sin_port = htons(port_id);
os_memcpy(&ctrl->dest.sin_addr.s_addr, h->h_addr, h->h_length);
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
} else
ctrl->remote_ip = os_strdup("localhost");
#endif /* CONFIG_CTRL_IFACE_UDP_REMOTE */
if (connect(ctrl->s, (struct sockaddr *) &ctrl->dest,
sizeof(ctrl->dest)) < 0) {
#ifdef CONFIG_CTRL_IFACE_UDP_IPV6
char addr[INET6_ADDRSTRLEN];
wpa_printf(MSG_ERROR, "connect(%s:%d) failed: %s",
inet_ntop(AF_INET6, &ctrl->dest.sin6_addr, addr,
sizeof(ctrl->dest)),
ntohs(ctrl->dest.sin6_port),
strerror(errno));
#else /* CONFIG_CTRL_IFACE_UDP_IPV6 */
wpa_printf(MSG_ERROR, "connect(%s:%d) failed: %s",
inet_ntoa(ctrl->dest.sin_addr),
ntohs(ctrl->dest.sin_port),
strerror(errno));
#endif /* CONFIG_CTRL_IFACE_UDP_IPV6 */
close(ctrl->s);
os_free(ctrl->remote_ip);
os_free(ctrl);
return NULL;
}
len = sizeof(buf) - 1;
if (wpa_ctrl_request(ctrl, "GET_COOKIE", 10, buf, &len, NULL) == 0) {
buf[len] = '\0';
ctrl->cookie = os_strdup(buf);
}
if (wpa_ctrl_request(ctrl, "IFNAME", 6, buf, &len, NULL) == 0) {
buf[len] = '\0';
ctrl->remote_ifname = os_strdup(buf);
}
return ctrl;
}
char * wpa_ctrl_get_remote_ifname(struct wpa_ctrl *ctrl)
{
#define WPA_CTRL_MAX_PS_NAME 100
static char ps[WPA_CTRL_MAX_PS_NAME] = {};
os_snprintf(ps, WPA_CTRL_MAX_PS_NAME, "%s/%s",
ctrl->remote_ip, ctrl->remote_ifname);
return ps;
}
void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
close(ctrl->s);
os_free(ctrl->cookie);
os_free(ctrl->remote_ifname);
os_free(ctrl->remote_ip);
os_free(ctrl);
}
#endif /* CONFIG_CTRL_IFACE_UDP */
#ifdef CTRL_IFACE_SOCKET
int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
char *reply, size_t *reply_len,
void (*msg_cb)(char *msg, size_t len))
{
struct timeval tv;
struct os_reltime started_at;
int res;
fd_set rfds;
const char *_cmd;
char *cmd_buf = NULL;
size_t _cmd_len;
#ifdef CONFIG_CTRL_IFACE_UDP
if (ctrl->cookie) {
char *pos;
_cmd_len = os_strlen(ctrl->cookie) + 1 + cmd_len;
cmd_buf = os_malloc(_cmd_len);
if (cmd_buf == NULL)
return -1;
_cmd = cmd_buf;
pos = cmd_buf;
os_strlcpy(pos, ctrl->cookie, _cmd_len);
pos += os_strlen(ctrl->cookie);
*pos++ = ' ';
os_memcpy(pos, cmd, cmd_len);
} else
#endif /* CONFIG_CTRL_IFACE_UDP */
{
_cmd = cmd;
_cmd_len = cmd_len;
}
errno = 0;
started_at.sec = 0;
started_at.usec = 0;
retry_send:
if (send(ctrl->s, _cmd, _cmd_len, 0) < 0) {
if (errno == EAGAIN || errno == EBUSY || errno == EWOULDBLOCK)
{
/*
* Must be a non-blocking socket... Try for a bit
* longer before giving up.
*/
if (started_at.sec == 0)
os_get_reltime(&started_at);
else {
struct os_reltime n;
os_get_reltime(&n);
/* Try for a few seconds. */
if (os_reltime_expired(&n, &started_at, 5))
goto send_err;
}
os_sleep(1, 0);
goto retry_send;
}
send_err:
os_free(cmd_buf);
return -1;
}
os_free(cmd_buf);
for (;;) {
tv.tv_sec = 10;
tv.tv_usec = 0;
FD_ZERO(&rfds);
FD_SET(ctrl->s, &rfds);
res = select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
if (res < 0 && errno == EINTR)
continue;
if (res < 0)
return res;
if (FD_ISSET(ctrl->s, &rfds)) {
res = recv(ctrl->s, reply, *reply_len, 0);
if (res < 0)
return res;
if ((res > 0 && reply[0] == '<') ||
(res > 6 && strncmp(reply, "IFNAME=", 7) == 0)) {
/* This is an unsolicited message from
* wpa_supplicant, not the reply to the
* request. Use msg_cb to report this to the
* caller. */
if (msg_cb) {
/* Make sure the message is nul
* terminated. */
if ((size_t) res == *reply_len)
res = (*reply_len) - 1;
reply[res] = '\0';
msg_cb(reply, res);
}
continue;
}
*reply_len = res;
break;
} else {
return -2;
}
}
return 0;
}
#endif /* CTRL_IFACE_SOCKET */
static int wpa_ctrl_attach_helper(struct wpa_ctrl *ctrl, int attach)
{
char buf[10];
int ret;
size_t len = 10;
ret = wpa_ctrl_request(ctrl, attach ? "ATTACH" : "DETACH", 6,
buf, &len, NULL);
if (ret < 0)
return ret;
if (len == 3 && os_memcmp(buf, "OK\n", 3) == 0)
return 0;
return -1;
}
int wpa_ctrl_attach(struct wpa_ctrl *ctrl)
{
return wpa_ctrl_attach_helper(ctrl, 1);
}
int wpa_ctrl_detach(struct wpa_ctrl *ctrl)
{
return wpa_ctrl_attach_helper(ctrl, 0);
}
#ifdef CTRL_IFACE_SOCKET
int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
{
int res;
res = recv(ctrl->s, reply, *reply_len, 0);
if (res < 0)
return res;
*reply_len = res;
return 0;
}
int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
{
struct timeval tv;
fd_set rfds;
tv.tv_sec = 0;
tv.tv_usec = 0;
FD_ZERO(&rfds);
FD_SET(ctrl->s, &rfds);
select(ctrl->s + 1, &rfds, NULL, NULL, &tv);
return FD_ISSET(ctrl->s, &rfds);
}
int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
{
return ctrl->s;
}
#endif /* CTRL_IFACE_SOCKET */
#ifdef CONFIG_CTRL_IFACE_NAMED_PIPE
#ifndef WPA_SUPPLICANT_NAMED_PIPE
#define WPA_SUPPLICANT_NAMED_PIPE "WpaSupplicant"
#endif
#define NAMED_PIPE_PREFIX TEXT("\\\\.\\pipe\\") TEXT(WPA_SUPPLICANT_NAMED_PIPE)
struct wpa_ctrl * wpa_ctrl_open(const char *ctrl_path)
{
struct wpa_ctrl *ctrl;
DWORD mode;
TCHAR name[256];
int i, ret;
ctrl = os_malloc(sizeof(*ctrl));
if (ctrl == NULL)
return NULL;
os_memset(ctrl, 0, sizeof(*ctrl));
#ifdef UNICODE
if (ctrl_path == NULL)
ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX);
else
ret = _snwprintf(name, 256, NAMED_PIPE_PREFIX TEXT("-%S"),
ctrl_path);
#else /* UNICODE */
if (ctrl_path == NULL)
ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX);
else
ret = os_snprintf(name, 256, NAMED_PIPE_PREFIX "-%s",
ctrl_path);
#endif /* UNICODE */
if (os_snprintf_error(256, ret)) {
os_free(ctrl);
return NULL;
}
for (i = 0; i < 10; i++) {
ctrl->pipe = CreateFile(name, GENERIC_READ | GENERIC_WRITE, 0,
NULL, OPEN_EXISTING, 0, NULL);
/*
* Current named pipe server side in wpa_supplicant is
* re-opening the pipe for new clients only after the previous
* one is taken into use. This leaves a small window for race
* conditions when two connections are being opened at almost
* the same time. Retry if that was the case.
*/
if (ctrl->pipe != INVALID_HANDLE_VALUE ||
GetLastError() != ERROR_PIPE_BUSY)
break;
WaitNamedPipe(name, 1000);
}
if (ctrl->pipe == INVALID_HANDLE_VALUE) {
os_free(ctrl);
return NULL;
}
mode = PIPE_READMODE_MESSAGE;
if (!SetNamedPipeHandleState(ctrl->pipe, &mode, NULL, NULL)) {
CloseHandle(ctrl->pipe);
os_free(ctrl);
return NULL;
}
return ctrl;
}
void wpa_ctrl_close(struct wpa_ctrl *ctrl)
{
CloseHandle(ctrl->pipe);
os_free(ctrl);
}
int wpa_ctrl_request(struct wpa_ctrl *ctrl, const char *cmd, size_t cmd_len,
char *reply, size_t *reply_len,
void (*msg_cb)(char *msg, size_t len))
{
DWORD written;
DWORD readlen = *reply_len;
if (!WriteFile(ctrl->pipe, cmd, cmd_len, &written, NULL))
return -1;
if (!ReadFile(ctrl->pipe, reply, *reply_len, &readlen, NULL))
return -1;
*reply_len = readlen;
return 0;
}
int wpa_ctrl_recv(struct wpa_ctrl *ctrl, char *reply, size_t *reply_len)
{
DWORD len = *reply_len;
if (!ReadFile(ctrl->pipe, reply, *reply_len, &len, NULL))
return -1;
*reply_len = len;
return 0;
}
int wpa_ctrl_pending(struct wpa_ctrl *ctrl)
{
DWORD left;
if (!PeekNamedPipe(ctrl->pipe, NULL, 0, NULL, &left, NULL))
return -1;
return left ? 1 : 0;
}
int wpa_ctrl_get_fd(struct wpa_ctrl *ctrl)
{
return -1;
}
#endif /* CONFIG_CTRL_IFACE_NAMED_PIPE */
#endif /* CONFIG_CTRL_IFACE */