-static int process_pty(int master, pid_t pid, sigset_t *mask) {
-
- char in_buffer[LINE_MAX], out_buffer[LINE_MAX];
- 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;
- int ep = -1, signal_fd = -1, r;
- bool tried_orderly_shutdown = false;
-
- assert(master >= 0);
- assert(pid > 0);
- assert(mask);
-
- fd_nonblock(STDIN_FILENO, 1);
- fd_nonblock(STDOUT_FILENO, 1);
- fd_nonblock(master, 1);
-
- signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC);
- if (signal_fd < 0) {
- log_error("signalfd(): %m");
- r = -errno;
- goto finish;
- }
-
- ep = epoll_create1(EPOLL_CLOEXEC);
- if (ep < 0) {
- log_error("Failed to create epoll: %m");
- r = -errno;
- goto finish;
- }
-
- /* We read from STDIN only if this is actually a TTY,
- * otherwise we assume non-interactivity. */
- if (isatty(STDIN_FILENO)) {
- zero(stdin_ev);
- stdin_ev.events = EPOLLIN|EPOLLET;
- stdin_ev.data.fd = STDIN_FILENO;
-
- if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0) {
- log_error("Failed to register STDIN in epoll: %m");
- r = -errno;
- goto finish;
- }
- }
-
- zero(stdout_ev);
- stdout_ev.events = EPOLLOUT|EPOLLET;
- stdout_ev.data.fd = STDOUT_FILENO;
-
- zero(master_ev);
- master_ev.events = EPOLLIN|EPOLLOUT|EPOLLET;
- master_ev.data.fd = master;
-
- zero(signal_ev);
- signal_ev.events = EPOLLIN;
- signal_ev.data.fd = signal_fd;
-
- if (epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0) {
- if (errno != EPERM) {
- log_error("Failed to register stdout in epoll: %m");
- r = -errno;
- goto finish;
- }
- /* stdout without epoll support. Likely redirected to regular file. */
- stdout_writable = true;
- }
-
- if (epoll_ctl(ep, EPOLL_CTL_ADD, master, &master_ev) < 0 ||
- epoll_ctl(ep, EPOLL_CTL_ADD, signal_fd, &signal_ev) < 0) {
- log_error("Failed to register fds in epoll: %m");
- r = -errno;
- goto finish;
- }
-
- for (;;) {
- struct epoll_event ev[16];
- ssize_t k;
- int i, nfds;
-
- nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), -1);
- if (nfds < 0) {
-
- if (errno == EINTR || errno == EAGAIN)
- continue;
-
- log_error("epoll_wait(): %m");
- r = -errno;
- goto finish;
- }
-
- assert(nfds >= 1);
-
- for (i = 0; i < nfds; i++) {
- if (ev[i].data.fd == STDIN_FILENO) {
-
- if (ev[i].events & (EPOLLIN|EPOLLHUP))
- stdin_readable = true;
-
- } else if (ev[i].data.fd == STDOUT_FILENO) {
-
- if (ev[i].events & (EPOLLOUT|EPOLLHUP))
- stdout_writable = true;
-
- } else if (ev[i].data.fd == master) {
-
- if (ev[i].events & (EPOLLIN|EPOLLHUP))
- master_readable = true;
-
- if (ev[i].events & (EPOLLOUT|EPOLLHUP))
- master_writable = true;
-
- } else if (ev[i].data.fd == signal_fd) {
- struct signalfd_siginfo sfsi;
- ssize_t n;
-
- n = read(signal_fd, &sfsi, sizeof(sfsi));
- if (n != sizeof(sfsi)) {
-
- if (n >= 0) {
- log_error("Failed to read from signalfd: invalid block size");
- r = -EIO;
- goto finish;
- }
-
- if (errno != EINTR && errno != EAGAIN) {
- log_error("Failed to read from signalfd: %m");
- r = -errno;
- goto finish;
- }
- } else {
-
- if (sfsi.ssi_signo == SIGWINCH) {
- struct winsize ws;
-
- /* The window size changed, let's forward that. */
- if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) >= 0)
- ioctl(master, TIOCSWINSZ, &ws);
- } else if (sfsi.ssi_signo == SIGTERM && arg_boot && !tried_orderly_shutdown) {
-
- log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
-
- /* This only works for systemd... */
- tried_orderly_shutdown = true;
- kill(pid, SIGRTMIN+3);
-
- } else {
- r = 0;
- goto finish;
- }
- }
- }
- }
-
- while ((stdin_readable && in_buffer_full <= 0) ||
- (master_writable && in_buffer_full > 0) ||
- (master_readable && out_buffer_full <= 0) ||
- (stdout_writable && out_buffer_full > 0)) {
-
- if (stdin_readable && in_buffer_full < LINE_MAX) {
-
- k = read(STDIN_FILENO, in_buffer + in_buffer_full, LINE_MAX - in_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
- stdin_readable = false;
- else {
- log_error("read(): %m");
- r = -errno;
- goto finish;
- }
- } else
- in_buffer_full += (size_t) k;
- }
-
- if (master_writable && in_buffer_full > 0) {
-
- k = write(master, in_buffer, in_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
- master_writable = false;
- else {
- log_error("write(): %m");
- r = -errno;
- goto finish;
- }
-
- } else {
- assert(in_buffer_full >= (size_t) k);
- memmove(in_buffer, in_buffer + k, in_buffer_full - k);
- in_buffer_full -= k;
- }
- }
-
- if (master_readable && out_buffer_full < LINE_MAX) {
-
- k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
- master_readable = false;
- else {
- log_error("read(): %m");
- r = -errno;
- goto finish;
- }
- } else
- out_buffer_full += (size_t) k;
- }
-
- if (stdout_writable && out_buffer_full > 0) {
-
- k = write(STDOUT_FILENO, out_buffer, out_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN || errno == EPIPE || errno == ECONNRESET || errno == EIO)
- stdout_writable = false;
- else {
- log_error("write(): %m");
- r = -errno;
- goto finish;
- }
-
- } else {
- assert(out_buffer_full >= (size_t) k);
- memmove(out_buffer, out_buffer + k, out_buffer_full - k);
- out_buffer_full -= k;
- }
- }
- }
- }
-
-finish:
- if (ep >= 0)
- close_nointr_nofail(ep);
-
- if (signal_fd >= 0)
- close_nointr_nofail(signal_fd);
-
- return r;
-}
-
~ianmdlvl / elogind.git / blobdiff