#include <assert.h>

#include <dirent.h>

#include <errno.h>

#include <fcntl.h>

#include <unistd.h>

#include <string.h>

#include <signal.h>

#include <sys/socket.h>

#include <sys/un.h>

#include <sys/prctl.h>

#include <linux/sched.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <grp.h>

#include <pwd.h>

#include <sys/mount.h>

#include <linux/fs.h>

#ifdef HAVE_PAM

#include <security/pam_appl.h>

#endif

#include "execute.h"

#include "strv.h"

#include "macro.h"

#include "util.h"

#include "log.h"

#include "ioprio.h"

#include "securebits.h"

#include "cgroup.h"

#include "namespace.h"

#include "tcpwrap.h"

#define TTY_MODE 0620

static int shift_fds(int fds[], unsigned n_fds) {

int start, restart_from;

if (n_fds <= 0)

return 0;

/* Modifies the fds array! (sorts it) */

assert(fds);

start = 0;

for (;;) {

int i;

restart_from = -1;

for (i = start; i < (int) n_fds; i++) {

int nfd;

/* Already at right index? */

if (fds[i] == i+3)

continue;

if ((nfd = fcntl(fds[i], F_DUPFD, i+3)) < 0)

return -errno;

close_nointr_nofail(fds[i]);

fds[i] = nfd;

/* Hmm, the fd we wanted isn't free? Then

if (nfd != i+3 && restart_from < 0)

restart_from = i;

}

if (restart_from < 0)

break;

start = restart_from;

}

return 0;

}

static int flags_fds(const int fds[], unsigned n_fds, bool nonblock) {

unsigned i;

int r;

if (n_fds <= 0)

return 0;

assert(fds);

/* Drops/Sets O_NONBLOCK and FD_CLOEXEC from the file flags */

for (i = 0; i < n_fds; i++) {

if ((r = fd_nonblock(fds[i], nonblock)) < 0)

return r;

/* We unconditionally drop FD_CLOEXEC from the fds,

if ((r = fd_cloexec(fds[i], false)) < 0)

return r;

}

return 0;

}

static const char *tty_path(const ExecContext *context) {

assert(context);

if (context->tty_path)

return context->tty_path;

return "/dev/console";

}

static int open_null_as(int flags, int nfd) {

int fd, r;

assert(nfd >= 0);

if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0)

return -errno;

if (fd != nfd) {

r = dup2(fd, nfd) < 0 ? -errno : nfd;

close_nointr_nofail(fd);

} else

r = nfd;

return r;

}

static int connect_logger_as(const ExecContext *context, ExecOutput output, const char *ident, int nfd) {

int fd, r;

union {

struct sockaddr sa;

struct sockaddr_un un;

} sa;

assert(context);

assert(output < _EXEC_OUTPUT_MAX);

assert(ident);

assert(nfd >= 0);

if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)

return -errno;

zero(sa);

sa.sa.sa_family = AF_UNIX;

strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1);

if (connect(fd, &sa.sa, sizeof(sa)) < 0) {

close_nointr_nofail(fd);

return -errno;

}

if (shutdown(fd, SHUT_RD) < 0) {

close_nointr_nofail(fd);

return -errno;

}

/* We speak a very simple protocol between log server

dprintf(fd,

"%s\n"

"%i\n"

"%s\n"

"%i\n",

output == EXEC_OUTPUT_KMSG ? "kmsg" : "syslog",

context->syslog_priority,

context->syslog_identifier ? context->syslog_identifier : ident,

!context->syslog_no_prefix);

if (fd != nfd) {

r = dup2(fd, nfd) < 0 ? -errno : nfd;

close_nointr_nofail(fd);

} else

r = nfd;

return r;

}

static int open_terminal_as(const char *path, mode_t mode, int nfd) {

int fd, r;

assert(path);

assert(nfd >= 0);

if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)

return fd;

if (fd != nfd) {

r = dup2(fd, nfd) < 0 ? -errno : nfd;

close_nointr_nofail(fd);

} else

r = nfd;

return r;

}

static bool is_terminal_input(ExecInput i) {

return

i == EXEC_INPUT_TTY ||

i == EXEC_INPUT_TTY_FORCE ||

i == EXEC_INPUT_TTY_FAIL;

}

static int fixup_input(ExecInput std_input, int socket_fd) {

if (std_input == EXEC_INPUT_SOCKET && socket_fd < 0)

return EXEC_INPUT_NULL;

return std_input;

}

static int fixup_output(ExecOutput std_output, int socket_fd) {

if (std_output == EXEC_OUTPUT_SOCKET && socket_fd < 0)

return EXEC_OUTPUT_INHERIT;

return std_output;

}

static int setup_input(const ExecContext *context, int socket_fd) {

ExecInput i;

assert(context);

i = fixup_input(context->std_input, socket_fd);

switch (i) {

case EXEC_INPUT_NULL:

return open_null_as(O_RDONLY, STDIN_FILENO);

case EXEC_INPUT_TTY:

case EXEC_INPUT_TTY_FORCE:

case EXEC_INPUT_TTY_FAIL: {

int fd, r;

if ((fd = acquire_terminal(

tty_path(context),

i == EXEC_INPUT_TTY_FAIL,

i == EXEC_INPUT_TTY_FORCE,

false)) < 0)

return fd;

if (fd != STDIN_FILENO) {

r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;

close_nointr_nofail(fd);

} else

r = STDIN_FILENO;

return r;

}

case EXEC_INPUT_SOCKET:

return dup2(socket_fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;

default:

assert_not_reached("Unknown input type");

}

}

static int setup_output(const ExecContext *context, int socket_fd, const char *ident) {

ExecOutput o;

ExecInput i;

assert(context);

assert(ident);

i = fixup_input(context->std_input, socket_fd);

o = fixup_output(context->std_output, socket_fd);

/* This expects the input is already set up */

switch (o) {

case EXEC_OUTPUT_INHERIT:

/* If the input is connected to a terminal, inherit that... */

if (i != EXEC_INPUT_NULL)

return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;

/* For PID 1 stdout is always connected to /dev/null,

if (getppid() == 1)

return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);

return STDOUT_FILENO;

case EXEC_OUTPUT_NULL:

return open_null_as(O_WRONLY, STDOUT_FILENO);

case EXEC_OUTPUT_TTY:

if (is_terminal_input(i))

return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;

/* We don't reset the terminal if this is just about output */

return open_terminal_as(tty_path(context), O_WRONLY, STDOUT_FILENO);

case EXEC_OUTPUT_SYSLOG:

case EXEC_OUTPUT_KMSG:

return connect_logger_as(context, o, ident, STDOUT_FILENO);

case EXEC_OUTPUT_SOCKET:

assert(socket_fd >= 0);

return dup2(socket_fd, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;

default:

assert_not_reached("Unknown output type");

}

}

static int setup_error(const ExecContext *context, int socket_fd, const char *ident) {

ExecOutput o, e;

ExecInput i;

assert(context);

assert(ident);

i = fixup_input(context->std_input, socket_fd);

o = fixup_output(context->std_output, socket_fd);

e = fixup_output(context->std_error, socket_fd);

/* This expects the input and output are already set up */

/* Don't change the stderr file descriptor if we inherit all

if (e == EXEC_OUTPUT_INHERIT &&

o == EXEC_OUTPUT_INHERIT &&

i != EXEC_INPUT_NULL &&

getppid () != 1)

return STDERR_FILENO;

/* Duplicate form stdout if possible */

if (e == o || e == EXEC_OUTPUT_INHERIT)

return dup2(STDOUT_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;

switch (e) {

case EXEC_OUTPUT_NULL:

return open_null_as(O_WRONLY, STDERR_FILENO);

case EXEC_OUTPUT_TTY:

if (is_terminal_input(i))

return dup2(STDIN_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;

/* We don't reset the terminal if this is just about output */

return open_terminal_as(tty_path(context), O_WRONLY, STDERR_FILENO);

case EXEC_OUTPUT_SYSLOG:

case EXEC_OUTPUT_KMSG:

return connect_logger_as(context, e, ident, STDERR_FILENO);

case EXEC_OUTPUT_SOCKET:

assert(socket_fd >= 0);

return dup2(socket_fd, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;

default:

assert_not_reached("Unknown error type");

}

}

static int chown_terminal(int fd, uid_t uid) {

struct stat st;

assert(fd >= 0);

/* This might fail. What matters are the results. */

(void) fchown(fd, uid, -1);

(void) fchmod(fd, TTY_MODE);

if (fstat(fd, &st) < 0)

return -errno;

if (st.st_uid != uid || (st.st_mode & 0777) != TTY_MODE)

return -EPERM;

return 0;

}

static int setup_confirm_stdio(const ExecContext *context,

int *_saved_stdin,

int *_saved_stdout) {

int fd = -1, saved_stdin, saved_stdout = -1, r;

assert(context);

assert(_saved_stdin);

assert(_saved_stdout);

/* This returns positive EXIT_xxx return values instead of

if ((saved_stdin = fcntl(STDIN_FILENO, F_DUPFD, 3)) < 0)

return EXIT_STDIN;

if ((saved_stdout = fcntl(STDOUT_FILENO, F_DUPFD, 3)) < 0) {

r = EXIT_STDOUT;

goto fail;

}

if ((fd = acquire_terminal(

tty_path(context),

context->std_input == EXEC_INPUT_TTY_FAIL,

context->std_input == EXEC_INPUT_TTY_FORCE,

false)) < 0) {

r = EXIT_STDIN;

goto fail;

}

if (chown_terminal(fd, getuid()) < 0) {

r = EXIT_STDIN;

goto fail;

}

if (dup2(fd, STDIN_FILENO) < 0) {

r = EXIT_STDIN;

goto fail;

}

if (dup2(fd, STDOUT_FILENO) < 0) {

r = EXIT_STDOUT;

goto fail;

}

if (fd >= 2)

close_nointr_nofail(fd);

*_saved_stdin = saved_stdin;

*_saved_stdout = saved_stdout;

return 0;

fail:

if (saved_stdout >= 0)

close_nointr_nofail(saved_stdout);

if (saved_stdin >= 0)

close_nointr_nofail(saved_stdin);

if (fd >= 0)

close_nointr_nofail(fd);

return r;

}

static int restore_confirm_stdio(const ExecContext *context,

int *saved_stdin,

int *saved_stdout,

bool *keep_stdin,

bool *keep_stdout) {

assert(context);

assert(saved_stdin);

assert(*saved_stdin >= 0);

assert(saved_stdout);

assert(*saved_stdout >= 0);

/* This returns positive EXIT_xxx return values instead of

if (is_terminal_input(context->std_input)) {

/* The service wants terminal input. */

*keep_stdin = true;

*keep_stdout =

context->std_output == EXEC_OUTPUT_INHERIT ||

context->std_output == EXEC_OUTPUT_TTY;

} else {

/* If the service doesn't want a controlling terminal,

if (release_terminal() < 0)

return EXIT_STDIN;

if (dup2(*saved_stdin, STDIN_FILENO) < 0)

return EXIT_STDIN;

if (dup2(*saved_stdout, STDOUT_FILENO) < 0)

return EXIT_STDOUT;

*keep_stdout = *keep_stdin = false;

}

return 0;

}

static int get_group_creds(const char *groupname, gid_t *gid) {

struct group *g;

unsigned long lu;

assert(groupname);

assert(gid);

/* We enforce some special rules for gid=0: in order to avoid

if (streq(groupname, "root") || streq(groupname, "0")) {

*gid = 0;

return 0;

}

if (safe_atolu(groupname, &lu) >= 0) {

errno = 0;

g = getgrgid((gid_t) lu);

} else {

errno = 0;

g = getgrnam(groupname);

}

if (!g)

return errno != 0 ? -errno : -ESRCH;

*gid = g->gr_gid;

return 0;

}

static int get_user_creds(const char **username, uid_t *uid, gid_t *gid, const char **home) {

struct passwd *p;

unsigned long lu;

assert(username);

assert(*username);

assert(uid);

assert(gid);

assert(home);

/* We enforce some special rules for uid=0: in order to avoid

if (streq(*username, "root") || streq(*username, "0")) {

*username = "root";

*uid = 0;

*gid = 0;

*home = "/root";

return 0;

}

if (safe_atolu(*username, &lu) >= 0) {

errno = 0;

p = getpwuid((uid_t) lu);

/* If there are multiple users with the same id, make

if (*username && p)

*username = p->pw_name;

} else {

errno = 0;

p = getpwnam(*username);

}

if (!p)

return errno != 0 ? -errno : -ESRCH;

*uid = p->pw_uid;

*gid = p->pw_gid;

*home = p->pw_dir;

return 0;

}

static int enforce_groups(const ExecContext *context, const char *username, gid_t gid) {

bool keep_groups = false;

int r;

assert(context);

/* Lookup and ser GID and supplementary group list. Here too

if (context->group || username) {

if (context->group)

if ((r = get_group_creds(context->group, &gid)) < 0)

return r;

/* First step, initialize groups from /etc/groups */

if (username && gid != 0) {

if (initgroups(username, gid) < 0)

return -errno;

keep_groups = true;

}

/* Second step, set our gids */

if (setresgid(gid, gid, gid) < 0)

return -errno;

}

if (context->supplementary_groups) {

int ngroups_max, k;

gid_t *gids;

char **i;

/* Final step, initialize any manually set supplementary groups */

ngroups_max = (int) sysconf(_SC_NGROUPS_MAX);

if (!(gids = new(gid_t, ngroups_max)))

return -ENOMEM;

if (keep_groups) {

if ((k = getgroups(ngroups_max, gids)) < 0) {

free(gids);

return -errno;

}

} else

k = 0;

STRV_FOREACH(i, context->supplementary_groups) {

if (k >= ngroups_max) {

free(gids);

return -E2BIG;

}

if ((r = get_group_creds(*i, gids+k)) < 0) {

free(gids);

return r;

}

k++;

}

if (setgroups(k, gids) < 0) {

free(gids);

return -errno;

}

free(gids);

}

return 0;

}

static int enforce_user(const ExecContext *context, uid_t uid) {

int r;

assert(context);

/* Sets (but doesn't lookup) the uid and make sure we keep the

if (context->capabilities) {

cap_t d;

static const cap_value_t bits[] = {

CAP_SETUID, /* Necessary so that we can run setresuid() below */

CAP_SETPCAP /* Necessary so that we can set PR_SET_SECUREBITS later on */

};

/* First step: If we need to keep capabilities but

if (uid != 0) {

int sb = context->secure_bits|SECURE_KEEP_CAPS;

if (prctl(PR_GET_SECUREBITS) != sb)

if (prctl(PR_SET_SECUREBITS, sb) < 0)

return -errno;

}

/* Second step: set the capabilites. This will reduce

if (!(d = cap_dup(context->capabilities)))

return -errno;

if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||

cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) {

r = -errno;

cap_free(d);

return r;

}

if (cap_set_proc(d) < 0) {

r = -errno;

cap_free(d);

return r;

}

cap_free(d);

}

/* Third step: actually set the uids */

if (setresuid(uid, uid, uid) < 0)

return -errno;

/* At this point we should have all necessary capabilities but

return 0;

}

#ifdef HAVE_PAM

static int null_conv(

int num_msg,

const struct pam_message **msg,

struct pam_response **resp,

void *appdata_ptr) {

/* We don't support conversations */

return PAM_CONV_ERR;

}

static int setup_pam(

const char *name,

const char *user,

const char *tty,

char ***pam_env,

int fds[], unsigned n_fds) {

static const struct pam_conv conv = {

.conv = null_conv,

.appdata_ptr = NULL

};

pam_handle_t *handle = NULL;

sigset_t ss, old_ss;

int pam_code = PAM_SUCCESS;

char **e = NULL;

bool close_session = false;

pid_t pam_pid = 0, parent_pid;

assert(name);

assert(user);

assert(pam_env);

/* We set up PAM in the parent process, then fork. The child

if ((pam_code = pam_start(name, user, &conv, &handle)) != PAM_SUCCESS) {

handle = NULL;

goto fail;

}

if (tty)

if ((pam_code = pam_set_item(handle, PAM_TTY, tty)) != PAM_SUCCESS)

goto fail;

if ((pam_code = pam_acct_mgmt(handle, PAM_SILENT)) != PAM_SUCCESS)

goto fail;

if ((pam_code = pam_open_session(handle, PAM_SILENT)) != PAM_SUCCESS)

goto fail;

close_session = true;

if ((pam_code = pam_setcred(handle, PAM_ESTABLISH_CRED | PAM_SILENT)) != PAM_SUCCESS)

goto fail;

if ((!(e = pam_getenvlist(handle)))) {

pam_code = PAM_BUF_ERR;

goto fail;

}

/* Block SIGTERM, so that we know that it won't get lost in

if (sigemptyset(&ss) < 0 ||

sigaddset(&ss, SIGTERM) < 0 ||

sigprocmask(SIG_BLOCK, &ss, &old_ss) < 0)

goto fail;

parent_pid = getpid();

if ((pam_pid = fork()) < 0)

goto fail;

if (pam_pid == 0) {

int sig;

int r = EXIT_PAM;

/* The child's job is to reset the PAM session on

/* This string must fit in 10 chars (i.e. the length

rename_process("sd:pam");

/* Make sure we don't keep open the passed fds in this

close_many(fds, n_fds);

/* Wait until our parent died. This will most likely

if (prctl(PR_SET_PDEATHSIG, SIGTERM) < 0)

goto child_finish;

/* Check if our parent process might already have

if (getppid() == parent_pid) {

if (sigwait(&ss, &sig) < 0)

goto child_finish;

assert(sig == SIGTERM);

}

/* Only if our parent died we'll end the session */

if (getppid() != parent_pid)

if ((pam_code = pam_close_session(handle, PAM_DATA_SILENT)) != PAM_SUCCESS)

goto child_finish;

r = 0;

child_finish:

pam_end(handle, pam_code | PAM_DATA_SILENT);

_exit(r);

}

/* If the child was forked off successfully it will do all the

handle = NULL;

/* Unblock SIGSUR1 again in the parent */

if (sigprocmask(SIG_SETMASK, &old_ss, NULL) < 0)

goto fail;

/* We close the log explicitly here, since the PAM modules

closelog();

return 0;

fail:

if (handle) {

if (close_session)

pam_code = pam_close_session(handle, PAM_DATA_SILENT);

pam_end(handle, pam_code | PAM_DATA_SILENT);

}

strv_free(e);

closelog();

if (pam_pid > 1)

kill(pam_pid, SIGTERM);

return EXIT_PAM;

}

#endif

int exec_spawn(ExecCommand *command,

char **argv,

const ExecContext *context,

int fds[], unsigned n_fds,

char **environment,

bool apply_permissions,

bool apply_chroot,

bool confirm_spawn,

CGroupBonding *cgroup_bondings,

pid_t *ret) {

pid_t pid;

int r;

char *line;

int socket_fd;

assert(command);

assert(context);

assert(ret);

assert(fds || n_fds <= 0);

if (context->std_input == EXEC_INPUT_SOCKET ||

context->std_output == EXEC_OUTPUT_SOCKET ||

context->std_error == EXEC_OUTPUT_SOCKET) {

if (n_fds != 1)

return -EINVAL;

socket_fd = fds[0];

fds = NULL;

n_fds = 0;

} else

socket_fd = -1;

if (!argv)

argv = command->argv;

if (!(line = exec_command_line(argv)))

return -ENOMEM;

log_debug("About to execute: %s", line);

free(line);

if (cgroup_bondings)

if ((r = cgroup_bonding_realize_list(cgroup_bondings)))

return r;

if ((pid = fork()) < 0)

return -errno;

if (pid == 0) {

int i;

sigset_t ss;

const char *username = NULL, *home = NULL;

uid_t uid = (uid_t) -1;

gid_t gid = (gid_t) -1;

char **our_env = NULL, **pam_env = NULL, **final_env = NULL;

unsigned n_env = 0;

int saved_stdout = -1, saved_stdin = -1;

bool keep_stdout = false, keep_stdin = false;

/* child */

/* This string must fit in 10 chars (i.e. the length

rename_process("sd:exec");

/* We reset exactly these signals, since they are the

default_signals(SIGNALS_CRASH_HANDLER,

SIGNALS_IGNORE, -1);

if (sigemptyset(&ss) < 0 ||

sigprocmask(SIG_SETMASK, &ss, NULL) < 0) {

r = EXIT_SIGNAL_MASK;

goto fail;

}

if (!context->no_setsid)

if (setsid() < 0) {

r = EXIT_SETSID;

goto fail;

}

if (socket_fd >= 0 && context->tcpwrap_name)

if (!socket_tcpwrap(socket_fd, context->tcpwrap_name)) {

r = EXIT_TCPWRAP;

goto fail;

}

if (confirm_spawn) {

char response;

/* Set up terminal for the question */

if ((r = setup_confirm_stdio(context,

&saved_stdin, &saved_stdout)))

goto fail;

/* Now ask the question. */

if (!(line = exec_command_line(argv))) {

r = EXIT_MEMORY;

goto fail;

}

r = ask(&response, "yns", "Execute %s? [Yes, No, Skip] ", line);

free(line);

if (r < 0 || response == 'n') {

r = EXIT_CONFIRM;

goto fail;

} else if (response == 's') {

r = 0;

goto fail;

}

/* Release terminal for the question */

if ((r = restore_confirm_stdio(context,

&saved_stdin, &saved_stdout,

&keep_stdin, &keep_stdout)))

goto fail;

}

if (!keep_stdin)

if (setup_input(context, socket_fd) < 0) {

r = EXIT_STDIN;

goto fail;

}

if (!keep_stdout)

if (setup_output(context, socket_fd, file_name_from_path(command->path)) < 0) {

r = EXIT_STDOUT;

goto fail;

}

if (setup_error(context, socket_fd, file_name_from_path(command->path)) < 0) {

r = EXIT_STDERR;

goto fail;

}

if (cgroup_bondings)

if ((r = cgroup_bonding_install_list(cgroup_bondings, 0)) < 0) {

r = EXIT_CGROUP;

goto fail;

}

if (context->oom_adjust_set) {

char t[16];

snprintf(t, sizeof(t), "%i", context->oom_adjust);

char_array_0(t);

if (write_one_line_file("/proc/self/oom_adj", t) < 0) {

r = EXIT_OOM_ADJUST;

goto fail;

}

}

if (context->nice_set)

if (setpriority(PRIO_PROCESS, 0, context->nice) < 0) {

r = EXIT_NICE;

goto fail;

}

if (context->cpu_sched_set) {

struct sched_param param;

zero(param);

param.sched_priority = context->cpu_sched_priority;

if (sched_setscheduler(0, context->cpu_sched_policy |

(context->cpu_sched_reset_on_fork ? SCHED_RESET_ON_FORK : 0), &param) < 0) {

r = EXIT_SETSCHEDULER;

goto fail;

}

}

if (context->cpu_affinity_set)

if (sched_setaffinity(0, sizeof(context->cpu_affinity), &context->cpu_affinity) < 0) {

r = EXIT_CPUAFFINITY;

goto fail;

}

if (context->ioprio_set)

if (ioprio_set(IOPRIO_WHO_PROCESS, 0, context->ioprio) < 0) {

r = EXIT_IOPRIO;

goto fail;

}

if (context->timer_slack_ns_set)

if (prctl(PR_SET_TIMERSLACK, context->timer_slack_ns_set) < 0) {

r = EXIT_TIMERSLACK;

goto fail;

}

if (context->user) {

username = context->user;

if (get_user_creds(&username, &uid, &gid, &home) < 0) {

r = EXIT_USER;

goto fail;

}

if (is_terminal_input(context->std_input))

if (chown_terminal(STDIN_FILENO, uid) < 0) {

r = EXIT_STDIN;

goto fail;

}

}

#ifdef HAVE_PAM

if (context->pam_name && username) {

/* Make sure no fds leak into the PAM

if (close_all_fds(fds, n_fds) < 0) {

r = EXIT_FDS;

goto fail;

}

if (setup_pam(context->pam_name, username, context->tty_path, &pam_env, fds, n_fds) < 0) {

r = EXIT_PAM;

goto fail;

}

}

#endif

if (apply_permissions)

if (enforce_groups(context, username, uid) < 0) {

r = EXIT_GROUP;

goto fail;

}

umask(context->umask);

if (strv_length(context->read_write_dirs) > 0 ||

strv_length(context->read_only_dirs) > 0 ||

strv_length(context->inaccessible_dirs) > 0 ||

context->mount_flags != MS_SHARED ||

context->private_tmp)

if ((r = setup_namespace(

context->read_write_dirs,

context->read_only_dirs,

context->inaccessible_dirs,

context->private_tmp,

context->mount_flags)) < 0)

goto fail;

if (apply_chroot) {

if (context->root_directory)

if (chroot(context->root_directory) < 0) {

r = EXIT_CHROOT;

goto fail;

}

if (chdir(context->working_directory ? context->working_directory : "/") < 0) {

r = EXIT_CHDIR;

goto fail;

}

} else {

char *d;

if (asprintf(&d, "%s/%s",

context->root_directory ? context->root_directory : "",

context->working_directory ? context->working_directory : "") < 0) {

r = EXIT_MEMORY;

goto fail;

}

if (chdir(d) < 0) {

free(d);

r = EXIT_CHDIR;

goto fail;

}

free(d);

}

if (close_all_fds(fds, n_fds) < 0 ||

shift_fds(fds, n_fds) < 0 ||

flags_fds(fds, n_fds, context->non_blocking) < 0) {

r = EXIT_FDS;

goto fail;

}

if (apply_permissions) {

for (i = 0; i < RLIMIT_NLIMITS; i++) {

if (!context->rlimit[i])

continue;

if (setrlimit(i, context->rlimit[i]) < 0) {

r = EXIT_LIMITS;

goto fail;

}

}

if (context->user)

if (enforce_user(context, uid) < 0) {

r = EXIT_USER;

goto fail;

}

/* PR_GET_SECUREBITS is not priviliged, while

if (prctl(PR_GET_SECUREBITS) != context->secure_bits)

if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) {

r = EXIT_SECUREBITS;

goto fail;

}

if (context->capabilities)

if (cap_set_proc(context->capabilities) < 0) {

r = EXIT_CAPABILITIES;

goto fail;

}

}

if (!(our_env = new0(char*, 6))) {

r = EXIT_MEMORY;

goto fail;

}

if (n_fds > 0)

if (asprintf(our_env + n_env++, "LISTEN_PID=%llu", (unsigned long long) getpid()) < 0 ||

asprintf(our_env + n_env++, "LISTEN_FDS=%u", n_fds) < 0) {

r = EXIT_MEMORY;

goto fail;

}

if (home)

if (asprintf(our_env + n_env++, "HOME=%s", home) < 0) {

r = EXIT_MEMORY;

goto fail;

}

if (username)

if (asprintf(our_env + n_env++, "LOGNAME=%s", username) < 0 ||

asprintf(our_env + n_env++, "USER=%s", username) < 0) {

r = EXIT_MEMORY;

goto fail;

}

assert(n_env <= 6);

if (!(final_env = strv_env_merge(

4,

environment,

our_env,

context->environment,

pam_env,

NULL))) {

r = EXIT_MEMORY;

goto fail;

}

execve(command->path, argv, final_env);

r = EXIT_EXEC;

fail:

strv_free(our_env);

strv_free(final_env);

strv_free(pam_env);

if (saved_stdin >= 0)

close_nointr_nofail(saved_stdin);

if (saved_stdout >= 0)

close_nointr_nofail(saved_stdout);

_exit(r);

}

/* We add the new process to the cgroup both in the child (so

if (cgroup_bondings)

cgroup_bonding_install_list(cgroup_bondings, pid);

log_debug("Forked %s as %llu", command->path, (unsigned long long) pid);

command->exec_status.pid = pid;

command->exec_status.start_timestamp = now(CLOCK_REALTIME);

*ret = pid;

return 0;

}

void exec_context_init(ExecContext *c) {

assert(c);

c->umask = 0002;

c->ioprio = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 0);

c->cpu_sched_policy = SCHED_OTHER;

c->syslog_priority = LOG_DAEMON|LOG_INFO;

c->mount_flags = MS_SHARED;

}

void exec_context_done(ExecContext *c) {

unsigned l;

assert(c);

strv_free(c->environment);

c->environment = NULL;

for (l = 0; l < ELEMENTSOF(c->rlimit); l++) {

free(c->rlimit[l]);

c->rlimit[l] = NULL;

}

free(c->working_directory);

c->working_directory = NULL;

free(c->root_directory);

c->root_directory = NULL;

free(c->tty_path);

c->tty_path = NULL;

free(c->tcpwrap_name);

c->tcpwrap_name = NULL;

free(c->syslog_identifier);

c->syslog_identifier = NULL;

free(c->user);

c->user = NULL;

free(c->group);

c->group = NULL;

strv_free(c->supplementary_groups);

c->supplementary_groups = NULL;

free(c->pam_name);

c->pam_name = NULL;

if (c->capabilities) {

cap_free(c->capabilities);

c->capabilities = NULL;

}

strv_free(c->read_only_dirs);

c->read_only_dirs = NULL;

strv_free(c->read_write_dirs);

c->read_write_dirs = NULL;

strv_free(c->inaccessible_dirs);

c->inaccessible_dirs = NULL;

}

void exec_command_done(ExecCommand *c) {

assert(c);

free(c->path);

c->path = NULL;

strv_free(c->argv);

c->argv = NULL;

}

void exec_command_done_array(ExecCommand *c, unsigned n) {

unsigned i;

for (i = 0; i < n; i++)

exec_command_done(c+i);

}

void exec_command_free_list(ExecCommand *c) {

ExecCommand *i;

while ((i = c)) {

LIST_REMOVE(ExecCommand, command, c, i);

exec_command_done(i);

free(i);

}

}

void exec_command_free_array(ExecCommand **c, unsigned n) {

unsigned i;

for (i = 0; i < n; i++) {

exec_command_free_list(c[i]);

c[i] = NULL;

}

}

static void strv_fprintf(FILE *f, char **l) {

char **g;

assert(f);

STRV_FOREACH(g, l)

fprintf(f, " %s", *g);

}

void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {

char ** e;

unsigned i;

assert(c);

assert(f);

if (!prefix)

prefix = "";

fprintf(f,

"%sUMask: %04o\n"

"%sWorkingDirectory: %s\n"

"%sRootDirectory: %s\n"

"%sNonBlocking: %s\n"

"%sPrivateTmp: %s\n",

prefix, c->umask,

prefix, c->working_directory ? c->working_directory : "/",

prefix, c->root_directory ? c->root_directory : "/",

prefix, yes_no(c->non_blocking),

prefix, yes_no(c->private_tmp));

if (c->environment)

for (e = c->environment; *e; e++)

fprintf(f, "%sEnvironment: %s\n", prefix, *e);

if (c->tcpwrap_name)

fprintf(f,

"%sTCPWrapName: %s\n",

prefix, c->tcpwrap_name);

if (c->nice_set)

fprintf(f,

"%sNice: %i\n",

prefix, c->nice);

if (c->oom_adjust_set)

fprintf(f,

"%sOOMAdjust: %i\n",

prefix, c->oom_adjust);

for (i = 0; i < RLIM_NLIMITS; i++)

if (c->rlimit[i])

fprintf(f, "%s%s: %llu\n", prefix, rlimit_to_string(i), (unsigned long long) c->rlimit[i]->rlim_max);

if (c->ioprio_set)

fprintf(f,

"%sIOSchedulingClass: %s\n"

"%sIOPriority: %i\n",

prefix, ioprio_class_to_string(IOPRIO_PRIO_CLASS(c->ioprio)),

prefix, (int) IOPRIO_PRIO_DATA(c->ioprio));

if (c->cpu_sched_set)

fprintf(f,

"%sCPUSchedulingPolicy: %s\n"

"%sCPUSchedulingPriority: %i\n"

"%sCPUSchedulingResetOnFork: %s\n",

prefix, sched_policy_to_string(c->cpu_sched_policy),

prefix, c->cpu_sched_priority,

prefix, yes_no(c->cpu_sched_reset_on_fork));

if (c->cpu_affinity_set) {

fprintf(f, "%sCPUAffinity:", prefix);

for (i = 0; i < CPU_SETSIZE; i++)

if (CPU_ISSET(i, &c->cpu_affinity))

fprintf(f, " %i", i);

fputs("\n", f);

}

if (c->timer_slack_ns_set)

fprintf(f, "%sTimerSlackNS: %lu\n", prefix, c->timer_slack_ns);

fprintf(f,

"%sStandardInput: %s\n"

"%sStandardOutput: %s\n"

"%sStandardError: %s\n",

prefix, exec_input_to_string(c->std_input),

prefix, exec_output_to_string(c->std_output),

prefix, exec_output_to_string(c->std_error));

if (c->tty_path)

fprintf(f,

"%sTTYPath: %s\n",

prefix, c->tty_path);

if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KMSG ||

c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KMSG)

fprintf(f,

"%sSyslogFacility: %s\n"

"%sSyslogLevel: %s\n",

prefix, log_facility_to_string(LOG_FAC(c->syslog_priority)),

prefix, log_level_to_string(LOG_PRI(c->syslog_priority)));

if (c->capabilities) {

char *t;

if ((t = cap_to_text(c->capabilities, NULL))) {

fprintf(f, "%sCapabilities: %s\n",

prefix, t);

cap_free(t);

}

}

if (c->secure_bits)

fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",

prefix,

(c->secure_bits & SECURE_KEEP_CAPS) ? " keep-caps" : "",

(c->secure_bits & SECURE_KEEP_CAPS_LOCKED) ? " keep-caps-locked" : "",

(c->secure_bits & SECURE_NO_SETUID_FIXUP) ? " no-setuid-fixup" : "",

(c->secure_bits & SECURE_NO_SETUID_FIXUP_LOCKED) ? " no-setuid-fixup-locked" : "",

(c->secure_bits & SECURE_NOROOT) ? " noroot" : "",

(c->secure_bits & SECURE_NOROOT_LOCKED) ? "noroot-locked" : "");

if (c->capability_bounding_set_drop) {

fprintf(f, "%sCapabilityBoundingSetDrop:", prefix);

for (i = 0; i <= CAP_LAST_CAP; i++)

if (c->capability_bounding_set_drop & (1 << i)) {

char *t;

if ((t = cap_to_name(i))) {

fprintf(f, " %s", t);

free(t);

}

}

fputs("\n", f);

}

if (c->user)

fprintf(f, "%sUser: %s", prefix, c->user);

if (c->group)

fprintf(f, "%sGroup: %s", prefix, c->group);

if (strv_length(c->supplementary_groups) > 0) {

fprintf(f, "%sSupplementaryGroups:", prefix);

strv_fprintf(f, c->supplementary_groups);

fputs("\n", f);

}

if (c->pam_name)

fprintf(f, "%sPAMName: %s", prefix, c->pam_name);

if (strv_length(c->read_write_dirs) > 0) {

fprintf(f, "%sReadWriteDirs:", prefix);

strv_fprintf(f, c->read_write_dirs);

fputs("\n", f);

}

if (strv_length(c->read_only_dirs) > 0) {

fprintf(f, "%sReadOnlyDirs:", prefix);

strv_fprintf(f, c->read_only_dirs);

fputs("\n", f);

}

if (strv_length(c->inaccessible_dirs) > 0) {

fprintf(f, "%sInaccessibleDirs:", prefix);

strv_fprintf(f, c->inaccessible_dirs);

fputs("\n", f);

}

}

void exec_status_fill(ExecStatus *s, pid_t pid, int code, int status) {

assert(s);

s->pid = pid;

s->exit_timestamp = now(CLOCK_REALTIME);

s->code = code;

s->status = status;

}

void exec_status_dump(ExecStatus *s, FILE *f, const char *prefix) {

char buf[FORMAT_TIMESTAMP_MAX];

assert(s);

assert(f);

if (!prefix)

prefix = "";

if (s->pid <= 0)

return;

fprintf(f,

"%sPID: %llu\n",

prefix, (unsigned long long) s->pid);

if (s->start_timestamp > 0)

fprintf(f,

"%sStart Timestamp: %s\n",

prefix, format_timestamp(buf, sizeof(buf), s->start_timestamp));

if (s->exit_timestamp > 0)

fprintf(f,

"%sExit Timestamp: %s\n"

"%sExit Code: %s\n"

"%sExit Status: %i\n",

prefix, format_timestamp(buf, sizeof(buf), s->exit_timestamp),

prefix, sigchld_code_to_string(s->code),

prefix, s->status);

}

char *exec_command_line(char **argv) {

size_t k;

char *n, *p, **a;

bool first = true;

assert(argv);

k = 1;

STRV_FOREACH(a, argv)

k += strlen(*a)+3;

if (!(n = new(char, k)))

return NULL;

p = n;

STRV_FOREACH(a, argv) {

if (!first)

*(p++) = ' ';

else

first = false;

if (strpbrk(*a, WHITESPACE)) {

*(p++) = '\'';

p = stpcpy(p, *a);

*(p++) = '\'';

} else

p = stpcpy(p, *a);

}

*p = 0;

/* FIXME: this doesn't really handle arguments that have

return n;

}

void exec_command_dump(ExecCommand *c, FILE *f, const char *prefix) {

char *p2;

const char *prefix2;

char *cmd;

assert(c);

assert(f);

if (!prefix)

prefix = "";

p2 = strappend(prefix, "\t");

prefix2 = p2 ? p2 : prefix;

cmd = exec_command_line(c->argv);

fprintf(f,

"%sCommand Line: %s\n",

prefix, cmd ? cmd : strerror(ENOMEM));

free(cmd);

exec_status_dump(&c->exec_status, f, prefix2);

free(p2);

}

void exec_command_dump_list(ExecCommand *c, FILE *f, const char *prefix) {

assert(f);

if (!prefix)

prefix = "";

LIST_FOREACH(command, c, c)

exec_command_dump(c, f, prefix);

}

void exec_command_append_list(ExecCommand **l, ExecCommand *e) {

ExecCommand *end;

assert(l);

assert(e);

if (*l) {

/* It's kinda important that we keep the order here */

LIST_FIND_TAIL(ExecCommand, command, *l, end);

LIST_INSERT_AFTER(ExecCommand, command, *l, end, e);

} else

*l = e;

}

int exec_command_set(ExecCommand *c, const char *path, ...) {

va_list ap;

char **l, *p;

assert(c);

assert(path);

va_start(ap, path);

l = strv_new_ap(path, ap);

va_end(ap);

if (!l)

return -ENOMEM;

if (!(p = strdup(path))) {

strv_free(l);

return -ENOMEM;

}

free(c->path);

c->path = p;

strv_free(c->argv);

c->argv = l;

return 0;

}

const char* exit_status_to_string(ExitStatus status) {

/* We cast to int here, so that -Wenum doesn't complain that

switch ((int) status) {

case EXIT_SUCCESS:

return "SUCCESS";

case EXIT_FAILURE:

return "FAILURE";

case EXIT_INVALIDARGUMENT:

return "INVALIDARGUMENT";

case EXIT_NOTIMPLEMENTED:

return "NOTIMPLEMENTED";

case EXIT_NOPERMISSION:

return "NOPERMISSION";

case EXIT_NOTINSTALLED:

return "NOTINSSTALLED";

case EXIT_NOTCONFIGURED:

return "NOTCONFIGURED";

case EXIT_NOTRUNNING:

return "NOTRUNNING";

case EXIT_CHDIR:

return "CHDIR";

case EXIT_NICE:

return "NICE";

case EXIT_FDS:

return "FDS";

case EXIT_EXEC:

return "EXEC";

case EXIT_MEMORY:

return "MEMORY";

case EXIT_LIMITS:

return "LIMITS";

case EXIT_OOM_ADJUST:

return "OOM_ADJUST";

case EXIT_SIGNAL_MASK:

return "SIGNAL_MASK";

case EXIT_STDIN:

return "STDIN";

case EXIT_STDOUT:

return "STDOUT";

case EXIT_CHROOT:

return "CHROOT";

case EXIT_IOPRIO:

return "IOPRIO";

case EXIT_TIMERSLACK:

return "TIMERSLACK";

case EXIT_SECUREBITS:

return "SECUREBITS";

case EXIT_SETSCHEDULER:

return "SETSCHEDULER";

case EXIT_CPUAFFINITY:

return "CPUAFFINITY";

case EXIT_GROUP:

return "GROUP";

case EXIT_USER:

return "USER";

case EXIT_CAPABILITIES:

return "CAPABILITIES";

case EXIT_CGROUP:

return "CGROUP";

case EXIT_SETSID:

return "SETSID";

case EXIT_CONFIRM:

return "CONFIRM";

case EXIT_STDERR:

return "STDERR";

case EXIT_TCPWRAP:

return "TCPWRAP";

case EXIT_PAM:

return "PAM";

default:

return NULL;

}

}

static const char* const exec_input_table[_EXEC_INPUT_MAX] = {

[EXEC_INPUT_NULL] = "null",

[EXEC_INPUT_TTY] = "tty",

[EXEC_INPUT_TTY_FORCE] = "tty-force",

[EXEC_INPUT_TTY_FAIL] = "tty-fail",

[EXEC_INPUT_SOCKET] = "socket"

};

static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {

[EXEC_OUTPUT_INHERIT] = "inherit",

[EXEC_OUTPUT_NULL] = "null",

[EXEC_OUTPUT_TTY] = "tty",

[EXEC_OUTPUT_SYSLOG] = "syslog",

[EXEC_OUTPUT_KMSG] = "kmsg",

[EXEC_OUTPUT_SOCKET] = "socket"

};

DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);

DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);