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=== Description (from pull-request) ===
Scenario:
- lxc-attach to container with pty allocated inside of the container.
- shutdown container
lxc-attach did not reset the terminal attributes to oldtios which caused
various problems and users had to call /usr/bin/reset. This patch ensures that
lxc-attach resets oldtios even in such cases.
Additionally, this commit makes the exit code in main() cleaner and most of
all, correct. Before we called lxc_container_put() before waitpid(). Let's do
it the other way around!
Signed-off-by: Christian Brauner <christian.brau...@mailbox.org>
From f7bb32fc80b2de5837957a1f7aeac2982019feec Mon Sep 17 00:00:00 2001
From: Christian Brauner <christian.brau...@mailbox.org>
Date: Thu, 25 Feb 2016 11:57:11 +0100
Subject: [PATCH] lxc-attach: ensure that oldtios is set
Scenario:
- lxc-attach to container with pty allocated inside of the container.
- shutdown container
lxc-attach did not reset the terminal attributes to oldtios which caused
various problems and users had to call /usr/bin/reset. This patch ensures that
lxc-attach resets oldtios even in such cases.
Additionally, this commit makes the exit code in main() cleaner and most of
all, correct. Before we called lxc_container_put() before waitpid(). Let's do
it the other way around!
Signed-off-by: Christian Brauner <christian.brau...@mailbox.org>
---
src/lxc/lxc_attach.c | 65 ++++++++++++++++++++++++++++++++++------------------
1 file changed, 43 insertions(+), 22 deletions(-)
diff --git a/src/lxc/lxc_attach.c b/src/lxc/lxc_attach.c
index 3439b2f..fcccb72 100644
--- a/src/lxc/lxc_attach.c
+++ b/src/lxc/lxc_attach.c
@@ -207,6 +207,7 @@ struct wrapargs {
lxc_attach_command_t *command;
struct lxc_tty_state *ts;
struct lxc_console *console;
+ struct termios *oldtios;
int ptyfd;
};
@@ -286,16 +287,22 @@ static int pty_in_container(void *p)
return -1;
}
- /* Get termios from one of the stdfds. */
- struct termios oldtios;
- ret = lxc_setup_tios(args->ptyfd, &oldtios);
- if (ret < 0)
+ args->oldtios->c_iflag &= ~IGNBRK;
+ args->oldtios->c_iflag &= BRKINT;
+ args->oldtios->c_lflag &= ~(ECHO | ICANON | ISIG);
+ args->oldtios->c_cc[VMIN] = 1;
+ args->oldtios->c_cc[VTIME] = 0;
+
+ /* Set new termios. */
+ if (tcsetattr(args->ptyfd, TCSAFLUSH, args->oldtios)) {
+ ERROR("failed to set new terminal settings");
return -1;
+ }
/* Create master/slave fd pair for pty. */
pid = fork_pty(&master);
if (pid < 0)
- goto err1;
+ return -1;
/* Pass windowsize from one of the stdfds to the current masterfd. */
lxc_console_winsz(args->ptyfd, master);
@@ -317,7 +324,7 @@ static int pty_in_container(void *p)
args->ts = lxc_console_sigwinch_init(args->ptyfd, master);
if (!args->ts) {
ret = -1;
- goto err2;
+ goto err1;
}
args->ts->escape = -1;
args->ts->stdoutfd = STDOUT_FILENO;
@@ -327,7 +334,7 @@ static int pty_in_container(void *p)
ret = lxc_mainloop_open(&descr);
if (ret) {
ERROR("failed to create mainloop");
- goto err3;
+ goto err2;
}
/* Register sigwinch handler in mainloop. */
@@ -335,7 +342,7 @@ static int pty_in_container(void *p)
lxc_console_cb_sigwinch_fd, args->ts);
if (ret) {
ERROR("failed to add handler for SIGWINCH fd");
- goto err4;
+ goto err3;
}
/* Register i/o callbacks in mainloop. */
@@ -343,30 +350,28 @@ static int pty_in_container(void *p)
lxc_console_cb_tty_stdin, args->ts);
if (ret) {
ERROR("failed to add handler for stdinfd");
- goto err4;
+ goto err3;
}
ret = lxc_mainloop_add_handler(&descr, args->ts->masterfd,
lxc_console_cb_tty_master, args->ts);
if (ret) {
ERROR("failed to add handler for masterfd");
- goto err4;
+ goto err3;
}
ret = lxc_mainloop(&descr, -1);
if (ret) {
ERROR("mainloop returned an error");
- goto err4;
+ goto err3;
}
-err4:
- lxc_mainloop_close(&descr);
err3:
- lxc_console_sigwinch_fini(args->ts);
+ lxc_mainloop_close(&descr);
err2:
- close(args->ts->masterfd);
+ lxc_console_sigwinch_fini(args->ts);
err1:
- tcsetattr(args->ptyfd, TCSAFLUSH, &oldtios);
+ close(args->ts->masterfd);
ret = lxc_wait_for_pid_status(pid);
if (ret < 0)
@@ -537,6 +542,7 @@ int main(int argc, char *argv[])
wrap.command->argv = (char**)my_args.argv;
}
+ struct termios oldtios;
if (isatty(STDIN_FILENO) || isatty(STDOUT_FILENO) ||
isatty(STDERR_FILENO)) {
if (isatty(STDIN_FILENO))
wrap.ptyfd = STDIN_FILENO;
@@ -544,9 +550,19 @@ int main(int argc, char *argv[])
wrap.ptyfd = STDOUT_FILENO;
else if (isatty(STDERR_FILENO))
wrap.ptyfd = STDERR_FILENO;
+
+ /* Get current termios */
+ if (tcgetattr(wrap.ptyfd, &oldtios))
+ SYSERROR("failed to get current terminal settings");
+ wrap.oldtios = &oldtios;
+
+ /* Try to allocate pty in the container. */
ret = c->attach(c, pty_in_container, &wrap, &attach_options,
&pid);
- if (ret < 0)
+ if (ret < 0) {
+ wrap.oldtios = NULL;
+ /* Try to allocate pty on the host. */
ret = pty_on_host(c, &wrap, &pid);
+ }
} else {
if (my_args.argc > 1)
ret = c->attach(c, lxc_attach_run_command, &command,
&attach_options, &pid);
@@ -554,17 +570,22 @@ int main(int argc, char *argv[])
ret = c->attach(c, lxc_attach_run_shell, NULL,
&attach_options, &pid);
}
- lxc_container_put(c);
-
if (ret < 0)
- exit(EXIT_FAILURE);
+ goto out;
ret = lxc_wait_for_pid_status(pid);
if (ret < 0)
- exit(EXIT_FAILURE);
+ goto out;
if (WIFEXITED(ret))
- return WEXITSTATUS(ret);
+ ret = WEXITSTATUS(ret);
+
+out:
+ if (wrap.oldtios)
+ tcsetattr(wrap.ptyfd, TCSAFLUSH, &oldtios);
+ lxc_container_put(c);
+ if (ret >= 0)
+ exit(ret);
exit(EXIT_FAILURE);
}
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