From 98e5c02b1602eaaac5c63045fa7a06e40249445e Mon Sep 17 00:00:00 2001

From: Lennart Poettering <lennart@poettering.net>

Date: Wed, 18 Feb 2015 23:32:55 +0100

Subject: [PATCH] nspawn: when connected to pipes for stdin/stdout, pass them

 as-is to PID 1

Previously we always invoked the container PID 1 on /dev/console of the

container. With this change we do so only if nspawn was invoked

interactively (i.e. its stdin/stdout was connected to a TTY). In all other

cases we directly pass through the fds unmodified.

This has the benefit that nspawn can be added into shell pipelines.

https://bugs.freedesktop.org/show_bug.cgi?id=87732

Cherry-picked from: 9c857b9d160c10b4454fc9f83442c1878343422f

Resolves: #1307080

---

 src/machine/machinectl.c |  2 +-

 src/nspawn/nspawn.c      | 48 ++++++++++++++-----------

 src/run/run.c            |  2 +-

 src/shared/ptyfwd.c      | 75 +++++++++++++++++++++++-----------------

 src/shared/ptyfwd.h      |  2 +-

 5 files changed, 74 insertions(+), 55 deletions(-)

diff --git a/src/machine/machinectl.c b/src/machine/machinectl.c

index cfd3162fb7..1a58aeaf11 100644

--- a/src/machine/machinectl.c

+++ b/src/machine/machinectl.c

@@ -1427,7 +1427,7 @@ static int login_machine(int argc, char *argv[], void *userdata) {

         sd_event_add_signal(event, NULL, SIGINT, NULL, NULL);

         sd_event_add_signal(event, NULL, SIGTERM, NULL, NULL);

-        r = pty_forward_new(event, master, true, &forward);

+        r = pty_forward_new(event, master, true, false, &forward);

         if (r < 0)

                 return log_error_errno(r, "Failed to create PTY forwarder: %m");

diff --git a/src/nspawn/nspawn.c b/src/nspawn/nspawn.c

index 78bd584834..a37b64094b 100644

--- a/src/nspawn/nspawn.c

+++ b/src/nspawn/nspawn.c

@@ -3581,6 +3581,7 @@ int main(int argc, char *argv[]) {

         int ret = EXIT_SUCCESS;

         union in_addr_union exposed = {};

         _cleanup_release_lock_file_ LockFile tree_global_lock = LOCK_FILE_INIT, tree_local_lock = LOCK_FILE_INIT;

+        bool interactive;

         log_parse_environment();

         log_open();

@@ -3754,6 +3755,8 @@ int main(int argc, char *argv[]) {

                         goto finish;

         }

+        interactive = isatty(STDIN_FILENO) > 0 && isatty(STDOUT_FILENO) > 0;

+

         master = posix_openpt(O_RDWR|O_NOCTTY|O_CLOEXEC|O_NDELAY);

         if (master < 0) {

                 r = log_error_errno(errno, "Failed to acquire pseudo tty: %m");

@@ -3766,15 +3769,15 @@ int main(int argc, char *argv[]) {

                 goto finish;

         }

-        if (!arg_quiet)

-                log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",

-                         arg_machine, arg_image ?: arg_directory);

-

         if (unlockpt(master) < 0) {

                 r = log_error_errno(errno, "Failed to unlock tty: %m");

                 goto finish;

         }

+        if (!arg_quiet)

+                log_info("Spawning container %s on %s.\nPress ^] three times within 1s to kill container.",

+                         arg_machine, arg_image ?: arg_directory);

+

         assert_se(sigemptyset(&mask) == 0);

         sigset_add_many(&mask, SIGCHLD, SIGWINCH, SIGTERM, SIGINT, -1);

         assert_se(sigprocmask(SIG_BLOCK, &mask, NULL) == 0);

@@ -3860,9 +3863,6 @@ int main(int argc, char *argv[]) {

                         master = safe_close(master);

-                        close_nointr(STDIN_FILENO);

-                        close_nointr(STDOUT_FILENO);

-                        close_nointr(STDERR_FILENO);

                         kmsg_socket_pair[0] = safe_close(kmsg_socket_pair[0]);

                         rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);

@@ -3870,21 +3870,27 @@ int main(int argc, char *argv[]) {

                         reset_all_signal_handlers();

                         reset_signal_mask();

-                        r = open_terminal(console, O_RDWR);

-                        if (r != STDIN_FILENO) {

-                                if (r >= 0) {

-                                        safe_close(r);

-                                        r = -EINVAL;

-                                }

+                        if (interactive) {

+                                close_nointr(STDIN_FILENO);

+                                close_nointr(STDOUT_FILENO);

+                                close_nointr(STDERR_FILENO);

-                                log_error_errno(r, "Failed to open console: %m");

-                                _exit(EXIT_FAILURE);

-                        }

+                                r = open_terminal(console, O_RDWR);

+                                if (r != STDIN_FILENO) {

+                                        if (r >= 0) {

+                                                safe_close(r);

+                                                r = -EINVAL;

+                                        }

-                        if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||

-                            dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) {

-                                log_error_errno(errno, "Failed to duplicate console: %m");

-                                _exit(EXIT_FAILURE);

+                                        log_error_errno(r, "Failed to open console: %m");

+                                        _exit(EXIT_FAILURE);

+                                }

+

+                                if (dup2(STDIN_FILENO, STDOUT_FILENO) != STDOUT_FILENO ||

+                                    dup2(STDIN_FILENO, STDERR_FILENO) != STDERR_FILENO) {

+                                        log_error_errno(errno, "Failed to duplicate console: %m");

+                                        _exit(EXIT_FAILURE);

+                                }

                         }

                         if (setsid() < 0) {

@@ -4227,7 +4233,7 @@ int main(int argc, char *argv[]) {

                                 rtnl_socket_pair[0] = safe_close(rtnl_socket_pair[0]);

-                                r = pty_forward_new(event, master, true, &forward);

+                                r = pty_forward_new(event, master, true, !interactive, &forward);

                                 if (r < 0) {

                                         log_error_errno(r, "Failed to create PTY forwarder: %m");

                                         goto finish;

diff --git a/src/run/run.c b/src/run/run.c

index dd1338f3b4..4680342846 100644

--- a/src/run/run.c

+++ b/src/run/run.c

@@ -780,7 +780,7 @@ static int start_transient_service(

                 if (!arg_quiet)

                         log_info("Running as unit %s.\nPress ^] three times within 1s to disconnect TTY.", service);

-                r = pty_forward_new(event, master, false, &forward);

+                r = pty_forward_new(event, master, false, false, &forward);

                 if (r < 0)

                         return log_error_errno(r, "Failed to create PTY forwarder: %m");

diff --git a/src/shared/ptyfwd.c b/src/shared/ptyfwd.c

index 88b3f4e3c4..4402af123f 100644

--- a/src/shared/ptyfwd.c

+++ b/src/shared/ptyfwd.c

@@ -42,6 +42,8 @@ struct PTYForward {

         struct termios saved_stdin_attr;

         struct termios saved_stdout_attr;

+        bool read_only:1;

+

         bool saved_stdin:1;

         bool saved_stdout:1;

@@ -298,7 +300,13 @@ static int on_sigwinch_event(sd_event_source *e, const struct signalfd_siginfo *

         return 0;

 }

-int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, PTYForward **ret) {

+int pty_forward_new(

+                sd_event *event,

+                int master,

+                bool ignore_vhangup,

+                bool read_only,

+                PTYForward **ret) {

+

         _cleanup_(pty_forward_freep) PTYForward *f = NULL;

         struct winsize ws;

         int r;

@@ -307,6 +315,7 @@ int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, PTYForward

         if (!f)

                 return -ENOMEM;

+        f->read_only = read_only;

         f->ignore_vhangup = ignore_vhangup;

         if (event)

@@ -317,13 +326,15 @@ int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, PTYForward

                         return r;

         }

-        r = fd_nonblock(STDIN_FILENO, true);

-        if (r < 0)

-                return r;

+        if (!read_only) {

+                r = fd_nonblock(STDIN_FILENO, true);

+                if (r < 0)

+                        return r;

-        r = fd_nonblock(STDOUT_FILENO, true);

-        if (r < 0)

-                return r;

+                r = fd_nonblock(STDOUT_FILENO, true);

+                if (r < 0)

+                        return r;

+        }

         r = fd_nonblock(master, true);

         if (r < 0)

@@ -334,36 +345,34 @@ int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, PTYForward

         if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) >= 0)

                 (void)ioctl(master, TIOCSWINSZ, &ws);

-        if (tcgetattr(STDIN_FILENO, &f->saved_stdin_attr) >= 0) {

-                struct termios raw_stdin_attr;

-

-                f->saved_stdin = true;

+        if (!read_only) {

+                if (tcgetattr(STDIN_FILENO, &f->saved_stdin_attr) >= 0) {

+                        struct termios raw_stdin_attr;

-                raw_stdin_attr = f->saved_stdin_attr;

-                cfmakeraw(&raw_stdin_attr);

-                raw_stdin_attr.c_oflag = f->saved_stdin_attr.c_oflag;

-                tcsetattr(STDIN_FILENO, TCSANOW, &raw_stdin_attr);

-        }

+                        f->saved_stdin = true;

-        if (tcgetattr(STDOUT_FILENO, &f->saved_stdout_attr) >= 0) {

-                struct termios raw_stdout_attr;

+                        raw_stdin_attr = f->saved_stdin_attr;

+                        cfmakeraw(&raw_stdin_attr);

+                        raw_stdin_attr.c_oflag = f->saved_stdin_attr.c_oflag;

+                        tcsetattr(STDIN_FILENO, TCSANOW, &raw_stdin_attr);

+                }

-                f->saved_stdout = true;

+                if (tcgetattr(STDOUT_FILENO, &f->saved_stdout_attr) >= 0) {

+                        struct termios raw_stdout_attr;

-                raw_stdout_attr = f->saved_stdout_attr;

-                cfmakeraw(&raw_stdout_attr);

-                raw_stdout_attr.c_iflag = f->saved_stdout_attr.c_iflag;

-                raw_stdout_attr.c_lflag = f->saved_stdout_attr.c_lflag;

-                tcsetattr(STDOUT_FILENO, TCSANOW, &raw_stdout_attr);

-        }

+                        f->saved_stdout = true;

-        r = sd_event_add_io(f->event, &f->master_event_source, master, EPOLLIN|EPOLLOUT|EPOLLET, on_master_event, f);

-        if (r < 0)

-                return r;

+                        raw_stdout_attr = f->saved_stdout_attr;

+                        cfmakeraw(&raw_stdout_attr);

+                        raw_stdout_attr.c_iflag = f->saved_stdout_attr.c_iflag;

+                        raw_stdout_attr.c_lflag = f->saved_stdout_attr.c_lflag;

+                        tcsetattr(STDOUT_FILENO, TCSANOW, &raw_stdout_attr);

+                }

-        r = sd_event_add_io(f->event, &f->stdin_event_source, STDIN_FILENO, EPOLLIN|EPOLLET, on_stdin_event, f);

-        if (r < 0 && r != -EPERM)

-                return r;

+                r = sd_event_add_io(f->event, &f->stdin_event_source, STDIN_FILENO, EPOLLIN|EPOLLET, on_stdin_event, f);

+                if (r < 0 && r != -EPERM)

+                        return r;

+        }

         r = sd_event_add_io(f->event, &f->stdout_event_source, STDOUT_FILENO, EPOLLOUT|EPOLLET, on_stdout_event, f);

         if (r == -EPERM)

@@ -372,6 +381,10 @@ int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, PTYForward

         else if (r < 0)

                 return r;

+        r = sd_event_add_io(f->event, &f->master_event_source, master, EPOLLIN|EPOLLOUT|EPOLLET, on_master_event, f);

+        if (r < 0)

+                return r;

+

         r = sd_event_add_signal(f->event, &f->sigwinch_event_source, SIGWINCH, on_sigwinch_event, f);

         if (r < 0)

                 return r;

diff --git a/src/shared/ptyfwd.h b/src/shared/ptyfwd.h

index d3e229bd70..6208a543db 100644

--- a/src/shared/ptyfwd.h

+++ b/src/shared/ptyfwd.h

@@ -30,7 +30,7 @@

 typedef struct PTYForward PTYForward;

-int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, PTYForward **f);

+int pty_forward_new(sd_event *event, int master, bool ignore_vhangup, bool read_only, PTYForward **f);

 PTYForward *pty_forward_free(PTYForward *f);

 int pty_forward_get_last_char(PTYForward *f, char *ch);