486N/A

486N/A

486N/A#pragma GCC diagnostic ignored "-Wattributes"

486N/A

486N/A#include <assert.h>

486N/A#include <dirent.h>

3233N/A#include <errno.h>

486N/A#include <fcntl.h>

486N/A#include <unistd.h>

486N/A#include <string.h>

486N/A#include <signal.h>

486N/A#include <sys/socket.h>

486N/A#include <sys/un.h>

2976N/A#include <sys/prctl.h>

2976N/A#include <linux/sched.h>

536N/A

486N/A#include "execute.h"

1194N/A#include "strv.h"

#include "macro.h"

#include "util.h"

#include "log.h"

#include "ioprio.h"

#include "securebits.h"

static int close_fds(int except[], unsigned n_except) {

DIR *d;

struct dirent *de;

int r = 0;

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

if (!(d = opendir("/proc/self/fd")))

return -errno;

while ((de = readdir(d))) {

int fd;

if (de->d_name[0] == '.')

continue;

if ((r = safe_atoi(de->d_name, &fd)) < 0)

goto finish;

if (fd < 3)

continue;

if (fd == dirfd(d))

continue;

if (except) {

bool found;

unsigned i;

found = false;

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

if (except[i] == fd) {

found = true;

break;

}

if (found)

continue;

}

if ((r = close_nointr(fd)) < 0)

goto finish;

}

finish:

closedir(d);

return r;

}

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

int start, restart_from;

if (n_fds <= 0)

return 0;

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;

assert_se(close_nointr(fds[i]) == 0);

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(int fds[], unsigned n_fds) {

unsigned i;

if (n_fds <= 0)

return 0;

assert(fds);

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

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

int flags;

if ((flags = fcntl(fds[i], F_GETFL, 0)) < 0)

return -errno;

/* Since we are at it, let's make sure that nobody

if (fcntl(fds[i], F_SETFL, flags &~O_NONBLOCK) < 0)

return -errno;

if ((flags = fcntl(fds[i], F_GETFD, 0)) < 0)

return -errno;

/* Also make sure nobody forgot O_CLOEXEC for all our

if (fcntl(fds[i], F_SETFD, flags &~FD_CLOEXEC) < 0)

return -errno;

}

return 0;

}

static int replace_null_fd(int fd, int flags) {

int nfd;

assert(fd >= 0);

close_nointr(fd);

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

return -errno;

if (nfd != fd) {

close_nointr_nofail(nfd);

return -EIO;

}

return 0;

}

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

int r;

assert(context);

switch (context->output) {

case EXEC_OUTPUT_CONSOLE:

return 0;

case EXEC_OUTPUT_NULL:

if ((r = replace_null_fd(STDOUT_FILENO, O_WRONLY)) < 0 ||

(r = replace_null_fd(STDERR_FILENO, O_WRONLY)) < 0)

return r;

return 0;

case EXEC_OUTPUT_KERNEL:

case EXEC_OUTPUT_SYSLOG: {

int fd;

union {

struct sockaddr sa;

struct sockaddr_un un;

} sa;

close_nointr(STDOUT_FILENO);

close_nointr(STDERR_FILENO);

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

return -errno;

if (fd != STDOUT_FILENO) {

close_nointr_nofail(fd);

return -EIO;

}

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;

}

if ((fd = dup(fd)) < 0) {

close_nointr_nofail(fd);

return -errno;

}

if (fd != STDERR_FILENO) {

close_nointr_nofail(fd);

return -EIO;

}

/* We speak a very simple protocol between log server

fprintf(stderr,

"%s\n"

"%i\n"

"%s\n",

context->output == EXEC_OUTPUT_KERNEL ? "kmsg" : "syslog",

context->syslog_priority,

context->syslog_identifier ? context->syslog_identifier : ident);

return 0;

}

default:

assert_not_reached("Unknown output type");

}

}

static int setup_input(const ExecContext *context) {

int r;

assert(context);

switch (context->input) {

case EXEC_INPUT_CONSOLE:

return 0;

case EXEC_INPUT_NULL:

if ((r = replace_null_fd(STDIN_FILENO, O_RDONLY)) < 0)

return r;

return 0;

default:

assert_not_reached("Unknown input type");

}

}

int exec_spawn(const ExecCommand *command, const ExecContext *context, int *fds, unsigned n_fds, pid_t *ret) {

pid_t pid;

assert(command);

assert(context);

assert(ret);

assert(fds || n_fds <= 0);

log_debug("about to execute %s", command->path);

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

return -errno;

if (pid == 0) {

char **e, **f = NULL;

int i, r;

sigset_t ss;

/* child */

if (sigemptyset(&ss) < 0 ||

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

r = EXIT_SIGNAL_MASK;

goto fail;

}

if (setpgid(0, 0) < 0) {

r = EXIT_PGID;

goto fail;

}

umask(context->umask);

if (setup_input(context) < 0) {

r = EXIT_INPUT;

goto fail;

}

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

r = EXIT_OUTPUT;

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->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;

}

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 (close_fds(fds, n_fds) < 0 ||

shift_fds(fds, n_fds) < 0 ||

flags_fds(fds, n_fds) < 0) {

r = EXIT_FDS;

goto fail;

}

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->secure_bits) {

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

r = EXIT_SECUREBITS;

goto fail;

}

}

if (n_fds > 0) {

char a[64], b[64];

char *listen_env[3] = {

a,

b,

NULL

};

snprintf(a, sizeof(a), "LISTEN_PID=%llu", (unsigned long long) getpid());

snprintf(b, sizeof(b), "LISTEN_FDS=%u", n_fds);

a[sizeof(a)-1] = 0;

b[sizeof(b)-1] = 0;

if (context->environment) {

if (!(f = strv_merge(listen_env, context->environment))) {

r = EXIT_MEMORY;

goto fail;

}

e = f;

} else

e = listen_env;

} else

e = context->environment;

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

r = EXIT_EXEC;

fail:

strv_free(f);

_exit(r);

}

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

*ret = pid;

return 0;

}

void exec_context_init(ExecContext *c) {

assert(c);

c->umask = 0002;

c->oom_adjust = 0;

c->oom_adjust_set = false;

c->nice = 0;

c->nice_set = false;

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

c->ioprio_set = false;

c->cpu_sched_policy = SCHED_OTHER;

c->cpu_sched_priority = 0;

c->cpu_sched_set = false;

CPU_ZERO(&c->cpu_affinity);

c->cpu_affinity_set = false;

c->input = 0;

c->output = 0;

c->syslog_priority = LOG_DAEMON|LOG_INFO;

c->secure_bits = 0;

c->capability_bounding_set_drop = 0;

}

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->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;

if (c->capabilities) {

cap_free(c->capabilities);

c->capabilities = NULL;

}

}

void exec_command_free_list(ExecCommand *c) {

ExecCommand *i;

while ((i = c)) {

LIST_REMOVE(ExecCommand, command, c, i);

free(i->path);

strv_free(i->argv);

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;

}

}

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",

prefix, c->umask,

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

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

if (c->environment)

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

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

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,

"%sInput: %s\n"

"%sOutput: %s\n",

prefix, exec_input_to_string(c->input),

prefix, exec_output_to_string(c->output));

if (c->output == EXEC_OUTPUT_SYSLOG || c->output == EXEC_OUTPUT_KERNEL)

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 (c->supplementary_groups) {

char **g;

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

STRV_FOREACH(g, c->supplementary_groups)

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

fputs("\n", f);

}

}

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

assert(s);

s->pid = pid;

s->code = code;

s->status = status;

s->timestamp = now(CLOCK_REALTIME);

}

char *exec_command_line(ExecCommand *c) {

size_t k;

char *n, *p, **a;

bool first = true;

assert(c);

assert(c->argv);

k = 1;

STRV_FOREACH(a, c->argv)

k += strlen(*a)+3;

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

return NULL;

p = n;

STRV_FOREACH(a, c->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 *cmd;

assert(c);

assert(f);

if (!prefix)

prefix = "";

cmd = exec_command_line(c);

fprintf(f,

"%sCommand Line: %s\n",

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

free(cmd);

}

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);

}

static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {

[EXEC_OUTPUT_CONSOLE] = "console",

[EXEC_OUTPUT_NULL] = "null",

[EXEC_OUTPUT_SYSLOG] = "syslog",

[EXEC_OUTPUT_KERNEL] = "kernel"

};

DEFINE_STRING_TABLE_LOOKUP(exec_output, ExecOutput);

static const char* const exec_input_table[_EXEC_INPUT_MAX] = {

[EXEC_INPUT_NULL] = "null",

[EXEC_INPUT_CONSOLE] = "console"

};

DEFINE_STRING_TABLE_LOOKUP(exec_input, ExecInput);