summaryrefslogtreecommitdiff
path: root/execute.c
diff options
context:
space:
mode:
authorLennart Poettering <lennart@poettering.net>2010-04-13 02:06:27 +0200
committerLennart Poettering <lennart@poettering.net>2010-04-13 02:06:27 +0200
commit80876c20f64f87765242bc35895977ab6a855729 (patch)
treefdb82b57685c706f99fde5659d350b1d3b381eda /execute.c
parent4112df163517478207526e0d3e7278ab1acf1f9f (diff)
rework tty handling
We now make sure to run all services in their own session, possibly with a controlling terminal. This also extends the service and socket state machines a little.
Diffstat (limited to 'execute.c')
-rw-r--r--execute.c574
1 files changed, 464 insertions, 110 deletions
diff --git a/execute.c b/execute.c
index 3d2e511333..065296bafd 100644
--- a/execute.c
+++ b/execute.c
@@ -115,130 +115,320 @@ static int flags_fds(int fds[], unsigned n_fds, bool nonblock) {
return 0;
}
-static int replace_null_fd(int fd, int flags) {
- int nfd;
- assert(fd >= 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;
- close_nointr(fd);
+ assert(nfd >= 0);
- if ((nfd = open("/dev/null", flags|O_NOCTTY)) < 0)
+ if ((fd = open("/dev/null", flags|O_NOCTTY)) < 0)
return -errno;
- if (nfd != fd) {
- close_nointr_nofail(nfd);
- return -EIO;
- }
+ if (fd != nfd) {
+ r = dup2(fd, nfd) < 0 ? -errno : nfd;
+ close_nointr(fd);
+ } else
+ r = nfd;
- return 0;
+ return r;
}
-static int setup_output(const ExecContext *context, const char *ident) {
- int 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);
- switch (context->output) {
+ if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
+ return -errno;
- case EXEC_OUTPUT_CONSOLE:
- return 0;
+ zero(sa);
+ sa.sa.sa_family = AF_UNIX;
+ strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1);
- case EXEC_OUTPUT_NULL:
+ if (connect(fd, &sa.sa, sizeof(sa)) < 0) {
+ close_nointr_nofail(fd);
+ return -errno;
+ }
- if ((r = replace_null_fd(STDOUT_FILENO, O_WRONLY)) < 0 ||
- (r = replace_null_fd(STDERR_FILENO, O_WRONLY)) < 0)
- return r;
+ if (shutdown(fd, SHUT_RD) < 0) {
+ close_nointr_nofail(fd);
+ return -errno;
+ }
- return 0;
+ /* We speak a very simple protocol between log server
+ * and client: one line for the log destination (kmsg
+ * or syslog), followed by the priority field,
+ * followed by the process name. Since we replaced
+ * stdin/stderr we simple use stdio to write to
+ * it. Note that we use stderr, to minimize buffer
+ * flushing issues. */
+
+ dprintf(fd,
+ "%s\n"
+ "%i\n"
+ "%s\n",
+ output == EXEC_OUTPUT_KERNEL ? "kmsg" : "syslog",
+ context->syslog_priority,
+ context->syslog_identifier ? context->syslog_identifier : ident);
+
+ if (fd != nfd) {
+ r = dup2(fd, nfd) < 0 ? -errno : nfd;
+ close_nointr(fd);
+ } else
+ r = nfd;
- case EXEC_OUTPUT_KERNEL:
- case EXEC_OUTPUT_SYSLOG: {
+ return r;
+}
+static int open_terminal_as(const char *path, mode_t mode, int nfd) {
+ int fd, r;
- int fd;
- union {
- struct sockaddr sa;
- struct sockaddr_un un;
- } sa;
+ assert(path);
+ assert(nfd >= 0);
- close_nointr(STDOUT_FILENO);
- close_nointr(STDERR_FILENO);
+ if ((fd = open_terminal(path, mode | O_NOCTTY)) < 0)
+ return fd;
- if ((fd = socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
- return -errno;
+ if (fd != nfd) {
+ r = dup2(fd, nfd) < 0 ? -errno : nfd;
+ close_nointr_nofail(fd);
+ } else
+ r = nfd;
- if (fd != STDOUT_FILENO) {
- close_nointr_nofail(fd);
- return -EIO;
- }
+ return r;
+}
- zero(sa);
- sa.sa.sa_family = AF_UNIX;
- strncpy(sa.un.sun_path+1, LOGGER_SOCKET, sizeof(sa.un.sun_path)-1);
+static bool is_terminal_input(ExecInput i) {
+ return
+ i == EXEC_INPUT_TTY ||
+ i == EXEC_INPUT_TTY_FORCE ||
+ i == EXEC_INPUT_TTY_FAIL;
+}
- if (connect(fd, &sa.sa, sizeof(sa)) < 0) {
- close_nointr_nofail(fd);
- return -errno;
- }
+static int setup_input(const ExecContext *context) {
+ assert(context);
- if (shutdown(fd, SHUT_RD) < 0) {
- close_nointr_nofail(fd);
- return -errno;
- }
+ switch (context->std_input) {
- if ((fd = dup(fd)) < 0) {
- close_nointr_nofail(fd);
- return -errno;
- }
+ 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 != STDERR_FILENO) {
+ if ((fd = acquire_terminal(
+ tty_path(context),
+ context->std_input == EXEC_INPUT_TTY_FAIL,
+ context->std_input == EXEC_INPUT_TTY_FORCE)) < 0)
+ return fd;
+
+ if (fd != STDIN_FILENO) {
+ r = dup2(fd, STDIN_FILENO) < 0 ? -errno : STDIN_FILENO;
close_nointr_nofail(fd);
- return -EIO;
- }
+ } else
+ r = STDIN_FILENO;
+
+ return r;
+ }
+
+ default:
+ assert_not_reached("Unknown input type");
+ }
+}
+
+static int setup_output(const ExecContext *context, const char *ident) {
+ assert(context);
+ assert(ident);
+
+ /* This expects the input is already set up */
+
+ switch (context->std_output) {
- /* We speak a very simple protocol between log server
- * and client: one line for the log destination (kmsg
- * or syslog), followed by the priority field,
- * followed by the process name. Since we replaced
- * stdin/stderr we simple use stdio to write to
- * it. Note that we use stderr, to minimize buffer
- * flushing issues. */
-
- 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);
+ case EXEC_OUTPUT_INHERIT:
+
+ /* If the input is connected to a terminal, inherit that... */
+ if (is_terminal_input(context->std_input))
+ return dup2(STDIN_FILENO, STDOUT_FILENO) < 0 ? -errno : STDOUT_FILENO;
return 0;
+
+ case EXEC_OUTPUT_NULL:
+ return open_null_as(O_WRONLY, STDOUT_FILENO);
+
+ case EXEC_OUTPUT_TTY: {
+ if (is_terminal_input(context->std_input))
+ 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_KERNEL:
+ return connect_logger_as(context, context->std_output, ident, STDOUT_FILENO);
+
default:
assert_not_reached("Unknown output type");
}
}
-static int setup_input(const ExecContext *context) {
- int r;
-
+static int setup_error(const ExecContext *context, const char *ident) {
assert(context);
- switch (context->input) {
+ /* This expects the input and output are already set up */
- case EXEC_INPUT_CONSOLE:
- return 0;
+ /* Don't change the stderr file descriptor if we inherit all
+ * the way and are not on a tty */
+ if (context->std_error == EXEC_OUTPUT_INHERIT &&
+ context->std_output == EXEC_OUTPUT_INHERIT &&
+ !is_terminal_input(context->std_input))
+ return STDERR_FILENO;
- case EXEC_INPUT_NULL:
- if ((r = replace_null_fd(STDIN_FILENO, O_RDONLY)) < 0)
- return r;
+ /* Duplicate form stdout if possible */
+ if (context->std_error == context->std_output ||
+ context->std_error == EXEC_OUTPUT_INHERIT)
+ return dup2(STDOUT_FILENO, STDERR_FILENO) < 0 ? -errno : STDERR_FILENO;
- return 0;
+ switch (context->std_error) {
+
+ case EXEC_OUTPUT_NULL:
+ return open_null_as(O_WRONLY, STDERR_FILENO);
+
+ case EXEC_OUTPUT_TTY:
+ if (is_terminal_input(context->std_input))
+ 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_KERNEL:
+ return connect_logger_as(context, context->std_error, ident, STDERR_FILENO);
default:
- assert_not_reached("Unknown input type");
+ assert_not_reached("Unknown error type");
}
}
+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
+ * negative errno style values! */
+
+ 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)) < 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_conform_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
+ * negative errno style values! */
+
+ 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,
+ * then we need to get rid entirely of what we have
+ * already. */
+
+ 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;
@@ -452,6 +642,7 @@ int exec_spawn(ExecCommand *command,
int *fds, unsigned n_fds,
bool apply_permissions,
bool apply_chroot,
+ bool confirm_spawn,
CGroupBonding *cgroup_bondings,
pid_t *ret) {
@@ -485,6 +676,8 @@ int exec_spawn(ExecCommand *command,
gid_t gid = (gid_t) -1;
char **our_env = NULL, **final_env = NULL;
unsigned n_env = 0;
+ int saved_stdout = -1, saved_stdin = -1;
+ bool keep_stdout = false, keep_stdin = false;
/* child */
@@ -494,27 +687,59 @@ int exec_spawn(ExecCommand *command,
goto fail;
}
- if (context->new_session) {
- if (setsid() < 0) {
- r = EXIT_SETSID;
+ if (setsid() < 0) {
+ r = EXIT_SETSID;
+ goto fail;
+ }
+
+ umask(context->umask);
+
+ 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(command))) {
+ r = EXIT_MEMORY;
goto fail;
}
- } else {
- if (setpgid(0, 0) < 0) {
- r = EXIT_PGID;
+
+ 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_conform_stdio(context,
+ &saved_stdin, &saved_stdout,
+ &keep_stdin, &keep_stdout)))
+ goto fail;
}
- umask(context->umask);
+ if (!keep_stdin)
+ if (setup_input(context) < 0) {
+ r = EXIT_STDIN;
+ goto fail;
+ }
- if (setup_input(context) < 0) {
- r = EXIT_INPUT;
- goto fail;
- }
+ if (!keep_stdout)
+ if (setup_output(context, file_name_from_path(command->path)) < 0) {
+ r = EXIT_STDOUT;
+ goto fail;
+ }
- if (setup_output(context, file_name_from_path(command->path)) < 0) {
- r = EXIT_OUTPUT;
+ if (setup_error(context, file_name_from_path(command->path)) < 0) {
+ r = EXIT_STDERR;
goto fail;
}
@@ -697,9 +922,25 @@ int exec_spawn(ExecCommand *command,
strv_free(our_env);
strv_free(final_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
+ * that we can be sure that no user code is ever executed
+ * outside of the cgroup) and in the parent (so that we can be
+ * sure that when we kill the cgroup the process will be
+ * killed too). */
+ if (cgroup_bondings)
+ if ((r = cgroup_bonding_install_list(cgroup_bondings, pid)) < 0) {
+ r = EXIT_CGROUP;
+ goto fail;
+ }
log_debug("Forked %s as %llu", command->path, (unsigned long long) pid);
@@ -730,10 +971,10 @@ void exec_context_init(ExecContext *c) {
c->cpu_sched_reset_on_fork = false;
c->non_blocking = false;
- c->new_session = false;
- c->input = 0;
- c->output = 0;
+ c->std_input = 0;
+ c->std_output = 0;
+ c->std_error = 0;
c->syslog_priority = LOG_DAEMON|LOG_INFO;
c->secure_bits = 0;
@@ -758,6 +999,9 @@ void exec_context_done(ExecContext *c) {
free(c->root_directory);
c->root_directory = NULL;
+ free(c->tty_path);
+ c->tty_path = NULL;
+
free(c->syslog_identifier);
c->syslog_identifier = NULL;
@@ -826,13 +1070,11 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
"%sUMask: %04o\n"
"%sWorkingDirectory: %s\n"
"%sRootDirectory: %s\n"
- "%sNonBlocking: %s\n"
- "%sNewSession: %s\n",
+ "%sNonBlocking: %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->new_session));
+ prefix, yes_no(c->non_blocking));
if (c->environment)
for (e = c->environment; *e; e++)
@@ -880,12 +1122,20 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
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));
+ "%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->output == EXEC_OUTPUT_SYSLOG || c->output == EXEC_OUTPUT_KERNEL)
+ if (c->std_output == EXEC_OUTPUT_SYSLOG || c->std_output == EXEC_OUTPUT_KERNEL ||
+ c->std_error == EXEC_OUTPUT_SYSLOG || c->std_error == EXEC_OUTPUT_KERNEL)
fprintf(f,
"%sSyslogFacility: %s\n"
"%sSyslogLevel: %s\n",
@@ -1104,18 +1354,122 @@ int exec_command_set(ExecCommand *c, const char *path, ...) {
return 0;
}
+const char* exit_status_to_string(ExitStatus status) {
+ switch (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";
+
+ 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"
+};
+
static const char* const exec_output_table[_EXEC_OUTPUT_MAX] = {
- [EXEC_OUTPUT_CONSOLE] = "console",
+ [EXEC_OUTPUT_INHERIT] = "inherit",
[EXEC_OUTPUT_NULL] = "null",
+ [EXEC_OUTPUT_TTY] = "tty",
[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);