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nspawn: make tty code more robust against closed/reopened /dev/console

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This commit is contained in:
Lennart Poettering 2011-03-16 03:18:23 +01:00
parent 14f3c8252b
commit fd14078a3a
1 changed files with 12 additions and 57 deletions
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67
src/nspawn.c
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@ -371,7 +371,6 @@ static int process_pty(int master, sigset_t *mask) {
size_t in_buffer_full = 0, out_buffer_full = 0; size_t in_buffer_full = 0, out_buffer_full = 0;
struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev; struct epoll_event stdin_ev, stdout_ev, master_ev, signal_ev;
bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false; bool stdin_readable = false, stdout_writable = false, master_readable = false, master_writable = false;
bool stdin_rhup = false, stdout_whup = false, master_rhup = false, master_whup = false;
int ep = -1, signal_fd = -1, r; int ep = -1, signal_fd = -1, r;
fd_nonblock(STDIN_FILENO, 1); fd_nonblock(STDIN_FILENO, 1);
@ -415,7 +414,7 @@ static int process_pty(int master, sigset_t *mask) {
goto finish; goto finish;
} }
do { for (;;) {
struct epoll_event ev[16]; struct epoll_event ev[16];
ssize_t k; ssize_t k;
int i, nfds; int i, nfds;
@ -435,30 +434,20 @@ static int process_pty(int master, sigset_t *mask) {
for (i = 0; i < nfds; i++) { for (i = 0; i < nfds; i++) {
if (ev[i].data.fd == STDIN_FILENO) { if (ev[i].data.fd == STDIN_FILENO) {
if (!stdin_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN))) if (ev[i].events & (EPOLLIN|EPOLLHUP))
stdin_readable = true; stdin_readable = true;
} else if (ev[i].data.fd == STDOUT_FILENO) { } else if (ev[i].data.fd == STDOUT_FILENO) {
if (ev[i].events & EPOLLHUP) { if (ev[i].events & (EPOLLOUT|EPOLLHUP))
stdout_writable = false;
stdout_whup = true;
}
if (!stdout_whup && (ev[i].events & EPOLLOUT))
stdout_writable = true; stdout_writable = true;
} else if (ev[i].data.fd == master) { } else if (ev[i].data.fd == master) {
/* We don't connect EPOLLHUP to if (ev[i].events & (EPOLLIN|EPOLLHUP))
* master_whup here, since EPOLLHUP
* can happen when noone has opened
* the other side */
if (!master_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN)))
master_readable = true; master_readable = true;
if (!master_whup && (ev[i].events & EPOLLOUT)) if (ev[i].events & (EPOLLOUT|EPOLLHUP))
master_writable = true; master_writable = true;
} else if (ev[i].data.fd == signal_fd) { } else if (ev[i].data.fd == signal_fd) {
@ -482,7 +471,6 @@ static int process_pty(int master, sigset_t *mask) {
struct winsize ws; struct winsize ws;
/* The window size changed, let's forward that. */ /* The window size changed, let's forward that. */
if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0) if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
ioctl(master, TIOCSWINSZ, &ws); ioctl(master, TIOCSWINSZ, &ws);
} else { } else {
@ -502,34 +490,23 @@ static int process_pty(int master, sigset_t *mask) {
if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, BUFFER_SIZE - in_buffer_full)) < 0) { if ((k = read(STDIN_FILENO, in_buffer + in_buffer_full, BUFFER_SIZE - in_buffer_full)) < 0) {
if (errno == EAGAIN) if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
stdin_readable = false; stdin_readable = false;
else if (errno == EPIPE || errno == ECONNRESET || errno == EIO)
k = 0;
else { else {
log_error("read(): %m"); log_error("read(): %m");
goto finish; goto finish;
} }
} else } else
in_buffer_full += (size_t) k; in_buffer_full += (size_t) k;
if (k == 0) {
stdin_rhup = true;
stdin_readable = false;
shutdown(STDIN_FILENO, SHUT_RD);
}
} }
if (master_writable && in_buffer_full > 0) { if (master_writable && in_buffer_full > 0) {
if ((k = write(master, in_buffer, in_buffer_full)) < 0) { if ((k = write(master, in_buffer, in_buffer_full)) < 0) {
if (errno == EAGAIN) if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
master_writable = false; master_writable = false;
else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) { else {
master_whup = true;
master_writable = false;
} else {
log_error("write(): %m"); log_error("write(): %m");
goto finish; goto finish;
} }
@ -545,33 +522,23 @@ static int process_pty(int master, sigset_t *mask) {
if ((k = read(master, out_buffer + out_buffer_full, BUFFER_SIZE - out_buffer_full)) < 0) { if ((k = read(master, out_buffer + out_buffer_full, BUFFER_SIZE - out_buffer_full)) < 0) {
if (errno == EAGAIN) if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
master_readable = false; master_readable = false;
else if (errno == EPIPE || errno == ECONNRESET || errno == EIO)
k = 0;
else { else {
log_error("read(): %m"); log_error("read(): %m");
goto finish; goto finish;
} }
} else } else
out_buffer_full += (size_t) k; out_buffer_full += (size_t) k;
if (k == 0) {
master_rhup = true;
master_readable = false;
}
} }
if (stdout_writable && out_buffer_full > 0) { if (stdout_writable && out_buffer_full > 0) {
if ((k = write(STDOUT_FILENO, out_buffer, out_buffer_full)) < 0) { if ((k = write(STDOUT_FILENO, out_buffer, out_buffer_full)) < 0) {
if (errno == EAGAIN) if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
stdout_writable = false; stdout_writable = false;
else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) { else {
stdout_whup = true;
stdout_writable = false;
} else {
log_error("write(): %m"); log_error("write(): %m");
goto finish; goto finish;
} }
@ -583,20 +550,8 @@ static int process_pty(int master, sigset_t *mask) {
} }
} }
} }
if (stdin_rhup && in_buffer_full <= 0 && !master_whup) {
master_whup = true;
master_writable = false;
} }
if (master_rhup && out_buffer_full <= 0 && !stdout_whup) {
stdout_whup = true;
stdout_writable = false;
shutdown(STDOUT_FILENO, SHUT_WR);
}
} while (!stdout_whup || !master_whup);
finish: finish:
if (ep >= 0) if (ep >= 0)
close_nointr_nofail(ep); close_nointr_nofail(ep);