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/*
* Copyright (C) 2014-2018 Firejail Authors
*
* This file is part of firejail project
*
* 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; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/statvfs.h>
#include <sys/mount.h>
#include <dirent.h>
#include <sys/wait.h>
#include <fcntl.h>
// disable pulseaudio socket
void pulseaudio_disable(void) {
if (arg_debug)
printf("disable pulseaudio\n");
// blacklist user config directory
disable_file_path(cfg.homedir, ".config/pulse");
// blacklist pulseaudio socket in XDG_RUNTIME_DIR
char *name = getenv("XDG_RUNTIME_DIR");
if (name)
disable_file_path(name, "pulse/native");
// try the default location anyway
char *path;
if (asprintf(&path, "/run/user/%d", getuid()) == -1)
errExit("asprintf");
disable_file_path(path, "pulse/native");
free(path);
// blacklist any pulse* file in /tmp directory
DIR *dir;
if (!(dir = opendir("/tmp"))) {
// sleep 2 seconds and try again
sleep(2);
if (!(dir = opendir("/tmp"))) {
return;
}
}
struct dirent *entry;
while ((entry = readdir(dir))) {
if (strncmp(entry->d_name, "pulse-", 6) == 0) {
disable_file_path("/tmp", entry->d_name);
}
}
closedir(dir);
}
// disable shm in pulseaudio
void pulseaudio_init(void) {
struct stat s;
// do we have pulseaudio in the system?
if (stat("/etc/pulse/client.conf", &s) == -1) {
if (arg_debug)
printf("/etc/pulse/client.conf not found\n");
return;
}
// create the new user pulseaudio directory
if (mkdir(RUN_PULSE_DIR, 0700) == -1)
errExit("mkdir");
// mount it nosuid, noexec, nodev
fs_noexec(RUN_PULSE_DIR);
// create the new client.conf file
char *pulsecfg = NULL;
if (asprintf(&pulsecfg, "%s/client.conf", RUN_PULSE_DIR) == -1)
errExit("asprintf");
if (copy_file("/etc/pulse/client.conf", pulsecfg, -1, -1, 0644)) // root needed
errExit("copy_file");
FILE *fp = fopen(pulsecfg, "a");
if (!fp)
errExit("fopen");
fprintf(fp, "%s", "\nenable-shm = no\n");
SET_PERMS_STREAM(fp, getuid(), getgid(), 0644);
fclose(fp);
// hand over the directory to the user
if (set_perms(RUN_PULSE_DIR, getuid(), getgid(), 0700))
errExit("set_perms");
// create ~/.config/pulse directory if not present
char *homeusercfg;
if (asprintf(&homeusercfg, "%s/.config", cfg.homedir) == -1)
errExit("asprintf");
if (lstat(homeusercfg, &s) == -1) {
if (create_empty_dir_as_user(homeusercfg, 0700))
fs_logger2("create", homeusercfg);
}
else if (!S_ISDIR(s.st_mode)) {
if (S_ISLNK(s.st_mode))
fprintf(stderr, "Error: %s is a symbolic link\n", homeusercfg);
else
fprintf(stderr, "Error: %s is not a directory\n", homeusercfg);
exit(1);
}
free(homeusercfg);
if (asprintf(&homeusercfg, "%s/.config/pulse", cfg.homedir) == -1)
errExit("asprintf");
if (lstat(homeusercfg, &s) == -1) {
if (create_empty_dir_as_user(homeusercfg, 0700))
fs_logger2("create", homeusercfg);
}
else if (!S_ISDIR(s.st_mode)) {
if (S_ISLNK(s.st_mode))
fprintf(stderr, "Error: %s is a symbolic link\n", homeusercfg);
else
fprintf(stderr, "Error: %s is not a directory\n", homeusercfg);
exit(1);
}
// if we have ~/.config/pulse mount the new directory, else set environment variable.
if (stat(homeusercfg, &s) == 0) {
// get a file descriptor for ~/.config/pulse, fails if there is any symlink
int fd = safe_fd(homeusercfg, O_PATH|O_DIRECTORY|O_NOFOLLOW|O_CLOEXEC);
if (fd == -1)
errExit("safe_fd");
// confirm the actual mount destination is owned by the user
if (fstat(fd, &s) == -1)
errExit("fstat");
if (s.st_uid != getuid()) {
fprintf(stderr, "Error: %s is not owned by the current user\n", homeusercfg);
exit(1);
}
// preserve a read-only mount
struct statvfs vfs;
if (fstatvfs(fd, &vfs) == -1)
errExit("fstatvfs");
if ((vfs.f_flag & MS_RDONLY) == MS_RDONLY)
fs_rdonly(RUN_PULSE_DIR);
// mount via the link in /proc/self/fd
char *proc;
if (asprintf(&proc, "/proc/self/fd/%d", fd) == -1)
errExit("asprintf");
if (mount(RUN_PULSE_DIR, proc, "none", MS_BIND, NULL) < 0)
errExit("mount pulseaudio");
fs_logger2("tmpfs", homeusercfg);
free(proc);
close(fd);
// check /proc/self/mountinfo to confirm the mount is ok
MountData *mptr = get_last_mount();
if (strcmp(mptr->dir, homeusercfg) != 0 || strcmp(mptr->fstype, "tmpfs") != 0)
errLogExit("invalid pulseaudio mount");
char *p;
if (asprintf(&p, "%s/client.conf", homeusercfg) == -1)
errExit("asprintf");
fs_logger2("create", p);
free(p);
}
else {
// set environment
if (setenv("PULSE_CLIENTCONFIG", pulsecfg, 1) < 0)
errExit("setenv");
}
free(pulsecfg);
free(homeusercfg);
}
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