| /* |
| * os-posix.c |
| * |
| * Copyright (c) 2003-2008 Fabrice Bellard |
| * Copyright (c) 2010 Red Hat, Inc. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| * THE SOFTWARE. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include <sys/wait.h> |
| /*needed for MAP_POPULATE before including qemu-options.h */ |
| #include <pwd.h> |
| #include <grp.h> |
| #include <libgen.h> |
| |
| /* Needed early for CONFIG_BSD etc. */ |
| #include "sysemu/sysemu.h" |
| #include "net/slirp.h" |
| #include "qemu-options.h" |
| #include "qemu/rcu.h" |
| #include "qemu/error-report.h" |
| #include "qemu/log.h" |
| #include "qemu/cutils.h" |
| |
| #ifdef CONFIG_LINUX |
| #include <sys/prctl.h> |
| #endif |
| |
| static struct passwd *user_pwd; |
| static const char *chroot_dir; |
| static int daemonize; |
| static int daemon_pipe; |
| |
| void os_setup_early_signal_handling(void) |
| { |
| struct sigaction act; |
| sigfillset(&act.sa_mask); |
| act.sa_flags = 0; |
| act.sa_handler = SIG_IGN; |
| sigaction(SIGPIPE, &act, NULL); |
| } |
| |
| static void termsig_handler(int signal, siginfo_t *info, void *c) |
| { |
| qemu_system_killed(info->si_signo, info->si_pid); |
| } |
| |
| void os_setup_signal_handling(void) |
| { |
| struct sigaction act; |
| |
| memset(&act, 0, sizeof(act)); |
| act.sa_sigaction = termsig_handler; |
| act.sa_flags = SA_SIGINFO; |
| sigaction(SIGINT, &act, NULL); |
| sigaction(SIGHUP, &act, NULL); |
| sigaction(SIGTERM, &act, NULL); |
| } |
| |
| /* Find a likely location for support files using the location of the binary. |
| For installed binaries this will be "$bindir/../share/qemu". When |
| running from the build tree this will be "$bindir/../pc-bios". */ |
| #define SHARE_SUFFIX "/share/qemu" |
| #define BUILD_SUFFIX "/pc-bios" |
| char *os_find_datadir(void) |
| { |
| char *dir, *exec_dir; |
| char *res; |
| size_t max_len; |
| |
| exec_dir = qemu_get_exec_dir(); |
| if (exec_dir == NULL) { |
| return NULL; |
| } |
| dir = g_path_get_dirname(exec_dir); |
| |
| max_len = strlen(dir) + |
| MAX(strlen(SHARE_SUFFIX), strlen(BUILD_SUFFIX)) + 1; |
| res = g_malloc0(max_len); |
| snprintf(res, max_len, "%s%s", dir, SHARE_SUFFIX); |
| if (access(res, R_OK)) { |
| snprintf(res, max_len, "%s%s", dir, BUILD_SUFFIX); |
| if (access(res, R_OK)) { |
| g_free(res); |
| res = NULL; |
| } |
| } |
| |
| g_free(dir); |
| g_free(exec_dir); |
| return res; |
| } |
| #undef SHARE_SUFFIX |
| #undef BUILD_SUFFIX |
| |
| void os_set_proc_name(const char *s) |
| { |
| #if defined(PR_SET_NAME) |
| char name[16]; |
| if (!s) |
| return; |
| pstrcpy(name, sizeof(name), s); |
| /* Could rewrite argv[0] too, but that's a bit more complicated. |
| This simple way is enough for `top'. */ |
| if (prctl(PR_SET_NAME, name)) { |
| perror("unable to change process name"); |
| exit(1); |
| } |
| #else |
| fprintf(stderr, "Change of process name not supported by your OS\n"); |
| exit(1); |
| #endif |
| } |
| |
| /* |
| * Parse OS specific command line options. |
| * return 0 if option handled, -1 otherwise |
| */ |
| void os_parse_cmd_args(int index, const char *optarg) |
| { |
| switch (index) { |
| #ifdef CONFIG_SLIRP |
| case QEMU_OPTION_smb: |
| error_report("The -smb option is deprecated. " |
| "Please use '-netdev user,smb=...' instead."); |
| if (net_slirp_smb(optarg) < 0) |
| exit(1); |
| break; |
| #endif |
| case QEMU_OPTION_runas: |
| user_pwd = getpwnam(optarg); |
| if (!user_pwd) { |
| fprintf(stderr, "User \"%s\" doesn't exist\n", optarg); |
| exit(1); |
| } |
| break; |
| case QEMU_OPTION_chroot: |
| chroot_dir = optarg; |
| break; |
| case QEMU_OPTION_daemonize: |
| daemonize = 1; |
| break; |
| #if defined(CONFIG_LINUX) |
| case QEMU_OPTION_enablefips: |
| fips_set_state(true); |
| break; |
| #endif |
| } |
| } |
| |
| static void change_process_uid(void) |
| { |
| if (user_pwd) { |
| if (setgid(user_pwd->pw_gid) < 0) { |
| fprintf(stderr, "Failed to setgid(%d)\n", user_pwd->pw_gid); |
| exit(1); |
| } |
| if (initgroups(user_pwd->pw_name, user_pwd->pw_gid) < 0) { |
| fprintf(stderr, "Failed to initgroups(\"%s\", %d)\n", |
| user_pwd->pw_name, user_pwd->pw_gid); |
| exit(1); |
| } |
| if (setuid(user_pwd->pw_uid) < 0) { |
| fprintf(stderr, "Failed to setuid(%d)\n", user_pwd->pw_uid); |
| exit(1); |
| } |
| if (setuid(0) != -1) { |
| fprintf(stderr, "Dropping privileges failed\n"); |
| exit(1); |
| } |
| } |
| } |
| |
| static void change_root(void) |
| { |
| if (chroot_dir) { |
| if (chroot(chroot_dir) < 0) { |
| fprintf(stderr, "chroot failed\n"); |
| exit(1); |
| } |
| if (chdir("/")) { |
| perror("not able to chdir to /"); |
| exit(1); |
| } |
| } |
| |
| } |
| |
| void os_daemonize(void) |
| { |
| if (daemonize) { |
| pid_t pid; |
| int fds[2]; |
| |
| if (pipe(fds) == -1) { |
| exit(1); |
| } |
| |
| pid = fork(); |
| if (pid > 0) { |
| uint8_t status; |
| ssize_t len; |
| |
| close(fds[1]); |
| |
| do { |
| len = read(fds[0], &status, 1); |
| } while (len < 0 && errno == EINTR); |
| |
| /* only exit successfully if our child actually wrote |
| * a one-byte zero to our pipe, upon successful init */ |
| exit(len == 1 && status == 0 ? 0 : 1); |
| |
| } else if (pid < 0) { |
| exit(1); |
| } |
| |
| close(fds[0]); |
| daemon_pipe = fds[1]; |
| qemu_set_cloexec(daemon_pipe); |
| |
| setsid(); |
| |
| pid = fork(); |
| if (pid > 0) { |
| exit(0); |
| } else if (pid < 0) { |
| exit(1); |
| } |
| umask(027); |
| |
| signal(SIGTSTP, SIG_IGN); |
| signal(SIGTTOU, SIG_IGN); |
| signal(SIGTTIN, SIG_IGN); |
| rcu_after_fork(); |
| } |
| } |
| |
| void os_setup_post(void) |
| { |
| int fd = 0; |
| |
| if (daemonize) { |
| if (chdir("/")) { |
| perror("not able to chdir to /"); |
| exit(1); |
| } |
| TFR(fd = qemu_open("/dev/null", O_RDWR)); |
| if (fd == -1) { |
| exit(1); |
| } |
| } |
| |
| change_root(); |
| change_process_uid(); |
| |
| if (daemonize) { |
| uint8_t status = 0; |
| ssize_t len; |
| |
| dup2(fd, 0); |
| dup2(fd, 1); |
| /* In case -D is given do not redirect stderr to /dev/null */ |
| if (!qemu_logfile) { |
| dup2(fd, 2); |
| } |
| |
| close(fd); |
| |
| do { |
| len = write(daemon_pipe, &status, 1); |
| } while (len < 0 && errno == EINTR); |
| if (len != 1) { |
| exit(1); |
| } |
| } |
| } |
| |
| void os_set_line_buffering(void) |
| { |
| setvbuf(stdout, NULL, _IOLBF, 0); |
| } |
| |
| int qemu_create_pidfile(const char *filename) |
| { |
| char buffer[128]; |
| int len; |
| int fd; |
| |
| fd = qemu_open(filename, O_RDWR | O_CREAT, 0600); |
| if (fd == -1) { |
| return -1; |
| } |
| if (lockf(fd, F_TLOCK, 0) == -1) { |
| close(fd); |
| return -1; |
| } |
| len = snprintf(buffer, sizeof(buffer), FMT_pid "\n", getpid()); |
| if (write(fd, buffer, len) != len) { |
| close(fd); |
| return -1; |
| } |
| |
| /* keep pidfile open & locked forever */ |
| return 0; |
| } |
| |
| bool is_daemonized(void) |
| { |
| return daemonize; |
| } |
| |
| int os_mlock(void) |
| { |
| int ret = 0; |
| |
| ret = mlockall(MCL_CURRENT | MCL_FUTURE); |
| if (ret < 0) { |
| perror("mlockall"); |
| } |
| |
| return ret; |
| } |