./move.sh

1 files changed, 487 insertions, 0 deletions

diff --git a/src/libshared/ptyfwd.c b/src/libshared/ptyfwd.c
new file mode 100644
index 0000000000..a97e0d5143
--- /dev/null
+++ b/src/libshared/ptyfwd.c
@@ -0,0 +1,487 @@
+/***
+  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 <errno.h>
+#include <limits.h>
+#include <signal.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <sys/ioctl.h>
+#include <sys/time.h>
+#include <termios.h>
+#include <unistd.h>
+
+#include <systemd/sd-event.h>
+
+#include "alloc-util.h"
+#include "fd-util.h"
+#include "log.h"
+#include "macro.h"
+#include "ptyfwd.h"
+#include "time-util.h"
+
+struct PTYForward {
+        sd_event *event;
+
+        int master;
+
+        PTYForwardFlags flags;
+
+        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 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;
+
+        bool read_from_master: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 bool ignore_vhangup(PTYForward *f) {
+        assert(f);
+
+        if (f->flags & PTY_FORWARD_IGNORE_VHANGUP)
+                return true;
+
+        if ((f->flags & PTY_FORWARD_IGNORE_INITIAL_VHANGUP) && !f->read_from_master)
+                return true;
+
+        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 && ignore_vhangup(f)))
+                                        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->read_from_master = true;
+                                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,
+                PTYForwardFlags flags,
+                PTYForward **ret) {
+
+        _cleanup_(pty_forward_freep) PTYForward *f = NULL;
+        struct winsize ws;
+        int r;
+
+        f = new0(PTYForward, 1);
+        if (!f)
+                return -ENOMEM;
+
+        f->flags = flags;
+
+        if (event)
+                f->event = sd_event_ref(event);
+        else {
+                r = sd_event_default(&f->event);
+                if (r < 0)
+                        return r;
+        }
+
+        if (!(flags & PTY_FORWARD_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 (!(flags & PTY_FORWARD_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_source_unref(f->sigwinch_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 b) {
+        int r;
+
+        assert(f);
+
+        if (!!(f->flags & PTY_FORWARD_IGNORE_VHANGUP) == b)
+                return 0;
+
+        if (b)
+                f->flags |= PTY_FORWARD_IGNORE_VHANGUP;
+        else
+                f->flags &= ~PTY_FORWARD_IGNORE_VHANGUP;
+
+        if (!ignore_vhangup(f)) {
+
+                /* 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->flags & PTY_FORWARD_IGNORE_VHANGUP);
+}