From fd14078a3ab2110cd10e5eb55cdaeecfa51a189c Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Wed, 16 Mar 2011 03:18:23 +0100 Subject: [PATCH] nspawn: make tty code more robust against closed/reopened /dev/console --- src/nspawn.c | 69 +++++++++------------------------------------------- 1 file changed, 12 insertions(+), 57 deletions(-) diff --git a/src/nspawn.c b/src/nspawn.c index f8a190097..cd528deb7 100644 --- a/src/nspawn.c +++ b/src/nspawn.c @@ -371,7 +371,6 @@ static int process_pty(int master, sigset_t *mask) { size_t in_buffer_full = 0, out_buffer_full = 0; 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_rhup = false, stdout_whup = false, master_rhup = false, master_whup = false; int ep = -1, signal_fd = -1, r; fd_nonblock(STDIN_FILENO, 1); @@ -415,7 +414,7 @@ static int process_pty(int master, sigset_t *mask) { goto finish; } - do { + for (;;) { struct epoll_event ev[16]; ssize_t k; int i, nfds; @@ -435,30 +434,20 @@ static int process_pty(int master, sigset_t *mask) { for (i = 0; i < nfds; i++) { if (ev[i].data.fd == STDIN_FILENO) { - if (!stdin_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN))) + if (ev[i].events & (EPOLLIN|EPOLLHUP)) stdin_readable = true; } else if (ev[i].data.fd == STDOUT_FILENO) { - if (ev[i].events & EPOLLHUP) { - stdout_writable = false; - stdout_whup = true; - } - - if (!stdout_whup && (ev[i].events & EPOLLOUT)) + if (ev[i].events & (EPOLLOUT|EPOLLHUP)) stdout_writable = true; } else if (ev[i].data.fd == master) { - /* We don't connect EPOLLHUP to - * master_whup here, since EPOLLHUP - * can happen when noone has opened - * the other side */ - - if (!master_rhup && (ev[i].events & (EPOLLHUP|EPOLLIN))) + if (ev[i].events & (EPOLLIN|EPOLLHUP)) master_readable = true; - if (!master_whup && (ev[i].events & EPOLLOUT)) + if (ev[i].events & (EPOLLOUT|EPOLLHUP)) master_writable = true; } else if (ev[i].data.fd == signal_fd) { @@ -482,7 +471,6 @@ static int process_pty(int master, sigset_t *mask) { struct winsize ws; /* The window size changed, let's forward that. */ - if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0) ioctl(master, TIOCSWINSZ, &ws); } 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 (errno == EAGAIN) + if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) stdin_readable = false; - else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) - k = 0; else { log_error("read(): %m"); goto finish; } } else 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 ((k = write(master, in_buffer, in_buffer_full)) < 0) { - if (errno == EAGAIN) - master_writable = false; - else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) { - master_whup = true; + if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) master_writable = false; - } else { + else { log_error("write(): %m"); 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 (errno == EAGAIN) + if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) master_readable = false; - else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) - k = 0; else { log_error("read(): %m"); goto finish; } } else out_buffer_full += (size_t) k; - - if (k == 0) { - master_rhup = true; - master_readable = false; - } } if (stdout_writable && out_buffer_full > 0) { if ((k = write(STDOUT_FILENO, out_buffer, out_buffer_full)) < 0) { - if (errno == EAGAIN) - stdout_writable = false; - else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) { - stdout_whup = true; + if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO) stdout_writable = false; - } else { + else { log_error("write(): %m"); goto finish; } @@ -583,19 +550,7 @@ 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: if (ep >= 0) -- 2.30.2