+++ /dev/null
-/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
-
-/***
- This file is part of systemd.
-
- Copyright 2010-2013 Lennart Poettering
-
- systemd is free software; you can redistribute it and/or modify it
- under the terms of the GNU Lesser General Public License as published by
- the Free Software Foundation; either version 2.1 of the License, or
- (at your option) any later version.
-
- systemd is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Lesser General Public License for more details.
-
- You should have received a copy of the GNU Lesser General Public License
- along with systemd; If not, see <http://www.gnu.org/licenses/>.
-***/
-
-#include <sys/epoll.h>
-#include <sys/ioctl.h>
-#include <limits.h>
-#include <termios.h>
-
-#include "util.h"
-#include "ptyfwd.h"
-
-struct PTYForward {
- sd_event *event;
-
- int master;
-
- sd_event_source *stdin_event_source;
- sd_event_source *stdout_event_source;
- sd_event_source *master_event_source;
-
- sd_event_source *sigwinch_event_source;
-
- struct termios saved_stdin_attr;
- struct termios saved_stdout_attr;
-
- bool read_only:1;
-
- bool saved_stdin:1;
- bool saved_stdout:1;
-
- bool stdin_readable:1;
- bool stdin_hangup:1;
- bool stdout_writable:1;
- bool stdout_hangup:1;
- bool master_readable:1;
- bool master_writable:1;
- bool master_hangup:1;
-
- /* Continue reading after hangup? */
- bool ignore_vhangup:1;
-
- bool last_char_set:1;
- char last_char;
-
- char in_buffer[LINE_MAX], out_buffer[LINE_MAX];
- size_t in_buffer_full, out_buffer_full;
-
- usec_t escape_timestamp;
- unsigned escape_counter;
-};
-
-#define ESCAPE_USEC (1*USEC_PER_SEC)
-
-static bool look_for_escape(PTYForward *f, const char *buffer, size_t n) {
- const char *p;
-
- assert(f);
- assert(buffer);
- assert(n > 0);
-
- for (p = buffer; p < buffer + n; p++) {
-
- /* Check for ^] */
- if (*p == 0x1D) {
- usec_t nw = now(CLOCK_MONOTONIC);
-
- if (f->escape_counter == 0 || nw > f->escape_timestamp + ESCAPE_USEC) {
- f->escape_timestamp = nw;
- f->escape_counter = 1;
- } else {
- (f->escape_counter)++;
-
- if (f->escape_counter >= 3)
- return true;
- }
- } else {
- f->escape_timestamp = 0;
- f->escape_counter = 0;
- }
- }
-
- return false;
-}
-
-static int shovel(PTYForward *f) {
- ssize_t k;
-
- assert(f);
-
- while ((f->stdin_readable && f->in_buffer_full <= 0) ||
- (f->master_writable && f->in_buffer_full > 0) ||
- (f->master_readable && f->out_buffer_full <= 0) ||
- (f->stdout_writable && f->out_buffer_full > 0)) {
-
- if (f->stdin_readable && f->in_buffer_full < LINE_MAX) {
-
- k = read(STDIN_FILENO, f->in_buffer + f->in_buffer_full, LINE_MAX - f->in_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN)
- f->stdin_readable = false;
- else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) {
- f->stdin_readable = false;
- f->stdin_hangup = true;
-
- f->stdin_event_source = sd_event_source_unref(f->stdin_event_source);
- } else {
- log_error_errno(errno, "read(): %m");
- return sd_event_exit(f->event, EXIT_FAILURE);
- }
- } else if (k == 0) {
- /* EOF on stdin */
- f->stdin_readable = false;
- f->stdin_hangup = true;
-
- f->stdin_event_source = sd_event_source_unref(f->stdin_event_source);
- } else {
- /* Check if ^] has been
- * pressed three times within
- * one second. If we get this
- * we quite immediately. */
- if (look_for_escape(f, f->in_buffer + f->in_buffer_full, k))
- return sd_event_exit(f->event, EXIT_FAILURE);
-
- f->in_buffer_full += (size_t) k;
- }
- }
-
- if (f->master_writable && f->in_buffer_full > 0) {
-
- k = write(f->master, f->in_buffer, f->in_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN || errno == EIO)
- f->master_writable = false;
- else if (errno == EPIPE || errno == ECONNRESET) {
- f->master_writable = f->master_readable = false;
- f->master_hangup = true;
-
- f->master_event_source = sd_event_source_unref(f->master_event_source);
- } else {
- log_error_errno(errno, "write(): %m");
- return sd_event_exit(f->event, EXIT_FAILURE);
- }
- } else {
- assert(f->in_buffer_full >= (size_t) k);
- memmove(f->in_buffer, f->in_buffer + k, f->in_buffer_full - k);
- f->in_buffer_full -= k;
- }
- }
-
- if (f->master_readable && f->out_buffer_full < LINE_MAX) {
-
- k = read(f->master, f->out_buffer + f->out_buffer_full, LINE_MAX - f->out_buffer_full);
- if (k < 0) {
-
- /* Note that EIO on the master device
- * might be caused by vhangup() or
- * temporary closing of everything on
- * the other side, we treat it like
- * EAGAIN here and try again, unless
- * ignore_vhangup is off. */
-
- if (errno == EAGAIN || (errno == EIO && f->ignore_vhangup))
- f->master_readable = false;
- else if (errno == EPIPE || errno == ECONNRESET || errno == EIO) {
- f->master_readable = f->master_writable = false;
- f->master_hangup = true;
-
- f->master_event_source = sd_event_source_unref(f->master_event_source);
- } else {
- log_error_errno(errno, "read(): %m");
- return sd_event_exit(f->event, EXIT_FAILURE);
- }
- } else
- f->out_buffer_full += (size_t) k;
- }
-
- if (f->stdout_writable && f->out_buffer_full > 0) {
-
- k = write(STDOUT_FILENO, f->out_buffer, f->out_buffer_full);
- if (k < 0) {
-
- if (errno == EAGAIN)
- f->stdout_writable = false;
- else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) {
- f->stdout_writable = false;
- f->stdout_hangup = true;
- f->stdout_event_source = sd_event_source_unref(f->stdout_event_source);
- } else {
- log_error_errno(errno, "write(): %m");
- return sd_event_exit(f->event, EXIT_FAILURE);
- }
-
- } else {
-
- if (k > 0) {
- f->last_char = f->out_buffer[k-1];
- f->last_char_set = true;
- }
-
- assert(f->out_buffer_full >= (size_t) k);
- memmove(f->out_buffer, f->out_buffer + k, f->out_buffer_full - k);
- f->out_buffer_full -= k;
- }
- }
- }
-
- if (f->stdin_hangup || f->stdout_hangup || f->master_hangup) {
- /* Exit the loop if any side hung up and if there's
- * nothing more to write or nothing we could write. */
-
- if ((f->out_buffer_full <= 0 || f->stdout_hangup) &&
- (f->in_buffer_full <= 0 || f->master_hangup))
- return sd_event_exit(f->event, EXIT_SUCCESS);
- }
-
- return 0;
-}
-
-static int on_master_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
- PTYForward *f = userdata;
-
- assert(f);
- assert(e);
- assert(e == f->master_event_source);
- assert(fd >= 0);
- assert(fd == f->master);
-
- if (revents & (EPOLLIN|EPOLLHUP))
- f->master_readable = true;
-
- if (revents & (EPOLLOUT|EPOLLHUP))
- f->master_writable = true;
-
- return shovel(f);
-}
-
-static int on_stdin_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
- PTYForward *f = userdata;
-
- assert(f);
- assert(e);
- assert(e == f->stdin_event_source);
- assert(fd >= 0);
- assert(fd == STDIN_FILENO);
-
- if (revents & (EPOLLIN|EPOLLHUP))
- f->stdin_readable = true;
-
- return shovel(f);
-}
-
-static int on_stdout_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
- PTYForward *f = userdata;
-
- assert(f);
- assert(e);
- assert(e == f->stdout_event_source);
- assert(fd >= 0);
- assert(fd == STDOUT_FILENO);
-
- if (revents & (EPOLLOUT|EPOLLHUP))
- f->stdout_writable = true;
-
- return shovel(f);
-}
-
-static int on_sigwinch_event(sd_event_source *e, const struct signalfd_siginfo *si, void *userdata) {
- PTYForward *f = userdata;
- struct winsize ws;
-
- assert(f);
- assert(e);
- assert(e == f->sigwinch_event_source);
-
- /* The window size changed, let's forward that. */
- if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) >= 0)
- (void) ioctl(f->master, TIOCSWINSZ, &ws);
-
- return 0;
-}
-
-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;
-
- f = new0(PTYForward, 1);
- if (!f)
- return -ENOMEM;
-
- f->read_only = read_only;
- f->ignore_vhangup = ignore_vhangup;
-
- if (event)
- f->event = sd_event_ref(event);
- else {
- r = sd_event_default(&f->event);
- 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(master, true);
- if (r < 0)
- return r;
-
- f->master = master;
-
- if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) >= 0)
- (void) ioctl(master, TIOCSWINSZ, &ws);
-
- if (!read_only) {
- if (tcgetattr(STDIN_FILENO, &f->saved_stdin_attr) >= 0) {
- struct termios raw_stdin_attr;
-
- f->saved_stdin = true;
-
- 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);
- }
-
- if (tcgetattr(STDOUT_FILENO, &f->saved_stdout_attr) >= 0) {
- struct termios raw_stdout_attr;
-
- f->saved_stdout = true;
-
- 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->stdout_event_source, STDOUT_FILENO, EPOLLOUT|EPOLLET, on_stdout_event, f);
- if (r == -EPERM)
- /* stdout without epoll support. Likely redirected to regular file. */
- f->stdout_writable = true;
- 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;
-
- *ret = f;
- f = NULL;
-
- return 0;
-}
-
-PTYForward *pty_forward_free(PTYForward *f) {
-
- if (f) {
- sd_event_source_unref(f->stdin_event_source);
- sd_event_source_unref(f->stdout_event_source);
- sd_event_source_unref(f->master_event_source);
- sd_event_unref(f->event);
-
- if (f->saved_stdout)
- tcsetattr(STDOUT_FILENO, TCSANOW, &f->saved_stdout_attr);
- if (f->saved_stdin)
- tcsetattr(STDIN_FILENO, TCSANOW, &f->saved_stdin_attr);
-
- free(f);
- }
-
- /* STDIN/STDOUT should not be nonblocking normally, so let's
- * unconditionally reset it */
- fd_nonblock(STDIN_FILENO, false);
- fd_nonblock(STDOUT_FILENO, false);
-
- return NULL;
-}
-
-int pty_forward_get_last_char(PTYForward *f, char *ch) {
- assert(f);
- assert(ch);
-
- if (!f->last_char_set)
- return -ENXIO;
-
- *ch = f->last_char;
- return 0;
-}
-
-int pty_forward_set_ignore_vhangup(PTYForward *f, bool ignore_vhangup) {
- int r;
-
- assert(f);
-
- if (f->ignore_vhangup == ignore_vhangup)
- return 0;
-
- f->ignore_vhangup = ignore_vhangup;
- if (!f->ignore_vhangup) {
-
- /* We shall now react to vhangup()s? Let's check
- * immediately if we might be in one */
-
- f->master_readable = true;
- r = shovel(f);
- if (r < 0)
- return r;
- }
-
- return 0;
-}
-
-int pty_forward_get_ignore_vhangup(PTYForward *f) {
- assert(f);
-
- return f->ignore_vhangup;
-}
~ianmdlvl / elogind.git / blobdiff