Use O_CLOEXEC when creating FDs

This is needed so that new processes (created with fork+exec) don't
inherit open files, which can be important for a number of reasons.

Since O_CLOEXEC is relatively new (POSIX.1-2008, before that Linux
specific), we #define it to 0 in io.h to prevent compilation errors on
older/crappy systems. At least this is the plan.

input.c creates a pipe. For that, add a mp_set_cloexec() function (which
is based on Weston's code in vo_wayland.c, but more correct). We could
use pipe2() instead, but that is Linux specific. Technically, we have a
race condition, but it won't matter.

audio/filter/af_export.c

@@ -39,6 +39,8 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include "osdep/io.h"
+
 #include "talloc.h"
 #include "af.h"
 #include "mpvcore/path.h"
@@ -107,7 +109,7 @@ static int control(struct af_instance* af, int cmd, void* arg)
     }
 
     // Init memory mapping
-    s->fd = open(s->filename, O_RDWR | O_CREAT | O_TRUNC, 0640);
+    s->fd = open(s->filename, O_RDWR | O_CREAT | O_TRUNC | O_CLOEXEC, 0640);
     mp_msg(MSGT_AFILTER, MSGL_INFO, "[export] Exporting to file: %s\n", s->filename);
     if(s->fd < 0) {
       mp_msg(MSGT_AFILTER, MSGL_FATAL, "[export] Could not open/create file: %s\n",

mpvcore/input/input.c

@@ -2309,12 +2309,17 @@ struct input_ctx *mp_input_init(struct mpv_global *global)
     }
 
 #ifndef __MINGW32__
-    long ret = pipe(ictx->wakeup_pipe);
-    for (int i = 0; i < 2 && ret >= 0; i++) {
-        ret = fcntl(ictx->wakeup_pipe[i], F_GETFL);
-        if (ret < 0)
-            break;
-        ret = fcntl(ictx->wakeup_pipe[i], F_SETFL, ret | O_NONBLOCK);
+    int ret = pipe(ictx->wakeup_pipe);
+    if (ret == 0) {
+        for (int i = 0; i < 2 && ret >= 0; i++) {
+            mp_set_cloexec(ictx->wakeup_pipe[i]);
+            ret = fcntl(ictx->wakeup_pipe[i], F_GETFL);
+            if (ret < 0)
+                break;
+            ret = fcntl(ictx->wakeup_pipe[i], F_SETFL, ret | O_NONBLOCK);
+            if (ret < 0)
+                break;
+        }
     }
     if (ret < 0)
         MP_ERR(ictx, "Failed to initialize wakeup pipe: %s\n", strerror(errno));

mpvcore/player/command.c

@@ -65,6 +65,8 @@
 #include <sys/mman.h>
 #endif
 
+#include "osdep/io.h"
+
 #include "mp_core.h"
 #include "mp_lua.h"
 
@@ -2334,7 +2336,7 @@ static int overlay_add(struct MPContext *mpctx, int id, int x, int y,
             fd = -1;
         close_fd = false;
     } else {
-        fd = open(file, O_RDONLY | O_BINARY);
+        fd = open(file, O_RDONLY | O_BINARY | O_CLOEXEC);
     }
     void *p = mmap(NULL, h * stride, PROT_READ, MAP_SHARED, fd, offset);
     if (fd >= 0 && close_fd)

mpvcore/player/configfiles.c

@@ -51,7 +51,6 @@ bool mp_parse_cfgfiles(struct MPContext *mpctx)
     struct MPOpts *opts = mpctx->opts;
     m_config_t *conf = mpctx->mconfig;
     char *conffile;
-    int conffile_fd;
     if (!opts->load_config)
         return true;
     if (!m_config_parse_config_file(conf, MPLAYER_CONFDIR "/mpv.conf", 0) < 0)
@@ -60,11 +59,11 @@ bool mp_parse_cfgfiles(struct MPContext *mpctx)
     if ((conffile = mp_find_user_config_file("config")) == NULL)
         MP_ERR(mpctx, "mp_find_user_config_file(\"config\") problem\n");
     else {
-        if ((conffile_fd = open(conffile, O_CREAT | O_EXCL | O_WRONLY,
-                    0666)) != -1) {
+        int fd = open(conffile, O_CREAT | O_EXCL | O_WRONLY | O_CLOEXEC, 0666);
+        if (fd != -1) {
             MP_INFO(mpctx, "Creating config file: %s\n", conffile);
-            write(conffile_fd, DEF_CONFIG, sizeof(DEF_CONFIG) - 1);
-            close(conffile_fd);
+            write(fd, DEF_CONFIG, sizeof(DEF_CONFIG) - 1);
+            close(fd);
         }
         if (m_config_parse_config_file(conf, conffile, 0) < 0)
             return false;

osdep/io.c

@@ -19,6 +19,23 @@
  */
 
 #include "config.h"
+#include "osdep/io.h"
+
+// Set the CLOEXEC flag on the given fd.
+// On error, false is returned (and errno set).
+bool mp_set_cloexec(int fd)
+{
+#if defined(FD_CLOEXEC) && defined(F_SETFD)
+    if (fd >= 0) {
+        int flags = fcntl(fd, F_GETFD);
+        if (flags == -1)
+            return false;
+        if (fcntl(fd, F_SETFD, flags | FD_CLOEXEC) == -1)
+            return false;
+    }
+#endif
+    return true;
+}
 
 #ifdef _WIN32
 
@@ -27,7 +44,6 @@
 #include <stdio.h>
 #include <stddef.h>
 
-#include "osdep/io.h"
 #include "talloc.h"
 
 //copied and modified from libav

osdep/io.h

@@ -20,7 +20,18 @@
 #ifndef MPLAYER_OSDEP_IO
 #define MPLAYER_OSDEP_IO
 
+#include <stdbool.h>
 #include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+
+// This is in POSIX.1-2008, but support outside of Linux is scarce.
+#ifndef O_CLOEXEC
+#define O_CLOEXEC 0
+#endif
+
+bool mp_set_cloexec(int fd);
 
 #ifdef _WIN32
 #include <wchar.h>

stream/ai_oss.c

@@ -36,6 +36,8 @@
 #endif
 #endif
 
+#include "osdep/io.h"
+
 #include "audio_in.h"
 #include "mpvcore/mp_msg.h"
 
@@ -85,7 +87,7 @@ int ai_oss_init(audio_in_t *ai)
     int err;
     int ioctl_param;
 
-    ai->oss.audio_fd = open(ai->oss.device, O_RDONLY);
+    ai->oss.audio_fd = open(ai->oss.device, O_RDONLY | O_CLOEXEC);
     if (ai->oss.audio_fd < 0)
     {
 	mp_tmsg(MSGT_TV, MSGL_ERR, "Unable to open '%s': %s\n",

stream/cookies.c

@@ -99,7 +99,7 @@ static char *load_file(const char *filename, int64_t * length)
 
     mp_msg(MSGT_NETWORK, MSGL_V, "Loading cookie file: %s\n", filename);
 
-    fd = open(filename, O_RDONLY);
+    fd = open(filename, O_RDONLY | O_CLOEXEC);
     if (fd < 0) {
 	mp_msg(MSGT_NETWORK, MSGL_V, "Could not open");
 	goto err_out;

stream/dvb_tune.c

@@ -34,7 +34,9 @@
 #include <errno.h>
 #include <linux/dvb/dmx.h>
 #include <linux/dvb/frontend.h>
+
 #include "config.h"
+#include "osdep/io.h"
 #include "dvbin.h"
 #include "dvb_tune.h"
 #include "mpvcore/mp_msg.h"
@@ -88,7 +90,7 @@ int dvb_open_devices(dvb_priv_t *priv, int n, int demux_cnt)
 	sprintf(frontend_dev, "/dev/dvb/adapter%d/frontend0", n);
 	sprintf(dvr_dev, "/dev/dvb/adapter%d/dvr0", n);
 	sprintf(demux_dev, "/dev/dvb/adapter%d/demux0", n);
-	priv->fe_fd = open(frontend_dev, O_RDWR | O_NONBLOCK);
+	priv->fe_fd = open(frontend_dev, O_RDWR | O_NONBLOCK | O_CLOEXEC);
 	if(priv->fe_fd < 0)
 	{
 		mp_msg(MSGT_DEMUX, MSGL_ERR, "ERROR OPENING FRONTEND DEVICE %s: ERRNO %d\n", frontend_dev, errno);
@@ -98,7 +100,7 @@ int dvb_open_devices(dvb_priv_t *priv, int n, int demux_cnt)
 	mp_msg(MSGT_DEMUX, MSGL_V, "DVB_OPEN_DEVICES(%d)\n", demux_cnt);
 	for(i = 0; i < demux_cnt; i++)
 	{
-		priv->demux_fds[i] = open(demux_dev, O_RDWR | O_NONBLOCK);
+		priv->demux_fds[i] = open(demux_dev, O_RDWR | O_NONBLOCK | O_CLOEXEC);
 		if(priv->demux_fds[i] < 0)
 		{
 			mp_msg(MSGT_DEMUX, MSGL_ERR, "ERROR OPENING DEMUX 0: %d\n", errno);
@@ -112,7 +114,7 @@ int dvb_open_devices(dvb_priv_t *priv, int n, int demux_cnt)
 	}
 
 
-	priv->dvr_fd = open(dvr_dev, O_RDONLY| O_NONBLOCK);
+	priv->dvr_fd = open(dvr_dev, O_RDONLY| O_NONBLOCK | O_CLOEXEC);
 	if(priv->dvr_fd < 0)
 	{
 		mp_msg(MSGT_DEMUX, MSGL_ERR, "ERROR OPENING DVR DEVICE %s: %d\n", dvr_dev, errno);
@@ -143,7 +145,7 @@ int dvb_fix_demuxes(dvb_priv_t *priv, int cnt)
 	{
 		for(i = priv->demux_fds_cnt; i < cnt; i++)
 		{
-			priv->demux_fds[i] = open(demux_dev, O_RDWR | O_NONBLOCK);
+			priv->demux_fds[i] = open(demux_dev, O_RDWR | O_NONBLOCK | O_CLOEXEC);
 			mp_msg(MSGT_DEMUX, MSGL_V, "FIX, OPEN fd(%d): %d\n", i, priv->demux_fds[i]);
 			if(priv->demux_fds[i] < 0)
 			{

stream/stream_dvb.c

@@ -42,10 +42,13 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 #include <fcntl.h>
 #include <errno.h>
 
+#include <libavutil/avstring.h>
+
+#include "osdep/io.h"
+
 #include "stream.h"
 #include "mpvcore/m_option.h"
 #include "mpvcore/path.h"
-#include "libavutil/avstring.h"
 
 #include "dvbin.h"
 
@@ -735,7 +738,7 @@ dvb_config_t *dvb_get_config(void)
 	for(i=0; i<MAX_CARDS; i++)
 	{
 		snprintf(filename, sizeof(filename), "/dev/dvb/adapter%d/frontend0", i);
-		fd = open(filename, O_RDONLY|O_NONBLOCK);
+		fd = open(filename, O_RDONLY|O_NONBLOCK|O_CLOEXEC);
 		if(fd < 0)
 		{
 			mp_msg(MSGT_DEMUX, MSGL_V, "DVB_CONFIG, can't open device %s, skipping\n", filename);

stream/stream_dvd_common.c

@@ -39,6 +39,8 @@
 #include <sys/ioctl.h>
 #endif
 
+#include "osdep/io.h"
+
 #include "mpvcore/mp_msg.h"
 #include "stream_dvd_common.h"
 
@@ -104,7 +106,7 @@ void dvd_set_speed(char *device, unsigned speed)
   AV_WB16(buffer + 18, 1000);
   AV_WB16(buffer + 26, 1000);
 
-  fd = open(device, O_RDWR | O_NONBLOCK);
+  fd = open(device, O_RDWR | O_NONBLOCK | O_CLOEXEC);
   if (fd == -1) {
     mp_tmsg(MSGT_OPEN, MSGL_INFO, "Couldn't open DVD device for writing, changing DVD speed needs write access.\n");
     return;

stream/stream_file.c

@@ -101,11 +101,11 @@ static int open_f(stream_t *stream, int mode)
     };
     stream->priv = priv;
 
-    mode_t m = 0;
+    mode_t m = O_CLOEXEC;
     if (mode == STREAM_READ)
-        m = O_RDONLY;
+        m |= O_RDONLY;
     else if (mode == STREAM_WRITE)
-        m = O_RDWR | O_CREAT | O_TRUNC;
+        m |= O_RDWR | O_CREAT | O_TRUNC;
     else {
         mp_msg(MSGT_OPEN, MSGL_ERR, "[file] Unknown open mode %d\n", mode);
         return STREAM_UNSUPPORTED;

stream/stream_pvr.c

@@ -42,6 +42,8 @@
 #include <libavutil/common.h>
 #include <libavutil/avstring.h>
 
+#include "osdep/io.h"
+
 #include "mpvcore/mp_msg.h"
 
 #include "stream.h"
@@ -1579,7 +1581,7 @@ pvr_stream_open (stream_t *stream, int mode)
   parse_encoder_options (pvr);
 
   /* open device */
-  pvr->dev_fd = open (pvr->video_dev, O_RDWR);
+  pvr->dev_fd = open (pvr->video_dev, O_RDWR | O_CLOEXEC);
   mp_msg (MSGT_OPEN, MSGL_INFO,
           "%s Using device %s\n", LOG_LEVEL_PVR, pvr->video_dev);
   if (pvr->dev_fd == -1)

stream/stream_radio.c

@@ -39,11 +39,14 @@
 #include <linux/videodev2.h>
 #endif
 
+#include <libavutil/avstring.h>
+
 #include "stream.h"
 #include "mpvcore/m_option.h"
 #include "mpvcore/mp_msg.h"
 #include "stream_radio.h"
-#include "libavutil/avstring.h"
+
+#include "osdep/io.h"
 
 #if HAVE_RADIO_CAPTURE
 #include "audio_in.h"
@@ -877,7 +880,7 @@ static int open_s(stream_t *stream,int mode)
     stream->close=close_s;
     stream->fill_buffer=fill_buffer_s;
 
-    priv->radio_fd = open(priv->radio_param->device, O_RDONLY);
+    priv->radio_fd = open(priv->radio_param->device, O_RDONLY | O_CLOEXEC);
     if (priv->radio_fd < 0) {
         mp_tmsg(MSGT_RADIO, MSGL_ERR, "[radio] Unable to open '%s': %s\n",
             priv->radio_param->device, strerror(errno));

stream/stream_vcd.c

@@ -56,6 +56,8 @@
 #define vcd_close(priv) (close(((mp_vcd_priv_t*)priv)->fd))
 #endif
 
+#include "osdep/io.h"
+
 static int fill_buffer(stream_t *s, char* buffer, int max_len){
   if(s->pos > s->end_pos) /// don't past end of current track
     return 0;
@@ -112,7 +114,7 @@ static int open_s(stream_t *stream,int mode)
 	  OPEN_EXISTING, FILE_FLAG_SEQUENTIAL_SCAN, NULL);
   f = _open_osfhandle((intptr_t)hd, _O_RDONLY);
 #else
-  f=open(dev,O_RDONLY);
+  f=open(dev,O_RDONLY | O_CLOEXEC);
 #endif
   if(f<0){
     mp_tmsg(MSGT_OPEN,MSGL_ERR,"CD-ROM Device '%s' not found.\n",dev);