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authorLennart Poettering <lennart@poettering.net>2014-10-31 16:54:11 +0100
committerLennart Poettering <lennart@poettering.net>2014-10-31 16:55:04 +0100
commit023fb90b83871a15ef7f57e8cd126e3426f99b9e (patch)
tree616c6080d064bcb8df72ef8a08899a15e5f8557b /src/shared/ptyfwd.c
parentfedfcdee6f55c3f183752b7fac4879bf41eed60b (diff)
ptyforward: rework PTY forwarder logic used by nspawn to utilize the normal event loop
We really should not run manual event loops anymore, but standardize on sd_event, so that we can run sd_bus connections from it eventually.
Diffstat (limited to 'src/shared/ptyfwd.c')
-rw-r--r--src/shared/ptyfwd.c534
1 files changed, 269 insertions, 265 deletions
diff --git a/src/shared/ptyfwd.c b/src/shared/ptyfwd.c
index d44d70bf9f..7c6e182e5b 100644
--- a/src/shared/ptyfwd.c
+++ b/src/shared/ptyfwd.c
@@ -28,13 +28,44 @@
#include "util.h"
#include "ptyfwd.h"
-#define ESCAPE_USEC USEC_PER_SEC
+struct PTYForward {
+ sd_event *event;
-static bool look_for_escape(usec_t *timestamp, unsigned *counter, const char *buffer, size_t n) {
+ 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 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;
+
+ 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(timestamp);
- assert(counter);
+ assert(f);
assert(buffer);
assert(n > 0);
@@ -44,343 +75,316 @@ static bool look_for_escape(usec_t *timestamp, unsigned *counter, const char *bu
if (*p == 0x1D) {
usec_t nw = now(CLOCK_MONOTONIC);
- if (*counter == 0 || nw > *timestamp + USEC_PER_SEC) {
- *timestamp = nw;
- *counter = 1;
+ if (f->escape_counter == 0 || nw > f->escape_timestamp + ESCAPE_USEC) {
+ f->escape_timestamp = nw;
+ f->escape_counter = 1;
} else {
- (*counter)++;
+ (f->escape_counter)++;
- if (*counter >= 3)
+ if (f->escape_counter >= 3)
return true;
}
} else {
- *timestamp = 0;
- *counter = 0;
+ f->escape_timestamp = 0;
+ f->escape_counter = 0;
}
}
return false;
}
-static int process_pty_loop(int master, sigset_t *mask, pid_t kill_pid, int signo) {
- 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;
- bool stdin_hangup = false, stdout_hangup = false, master_hangup = false;
- bool tried_orderly_shutdown = false, process_signalfd = false, quit = false;
- usec_t escape_timestamp = 0;
- unsigned escape_counter = 0;
- _cleanup_close_ int ep = -1, signal_fd = -1;
-
- assert(master >= 0);
- assert(mask);
- assert(kill_pid == 0 || kill_pid > 1);
- assert(signo >= 0 && signo < _NSIG);
-
- fd_nonblock(STDIN_FILENO, true);
- fd_nonblock(STDOUT_FILENO, true);
- fd_nonblock(master, true);
-
- signal_fd = signalfd(-1, mask, SFD_NONBLOCK|SFD_CLOEXEC);
- if (signal_fd < 0) {
- log_error("signalfd(): %m");
- return -errno;
- }
-
- ep = epoll_create1(EPOLL_CLOEXEC);
- if (ep < 0) {
- log_error("Failed to create epoll: %m");
- return -errno;
- }
+static int shovel(PTYForward *f) {
+ ssize_t k;
- /* 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;
+ assert(f);
- if (epoll_ctl(ep, EPOLL_CTL_ADD, STDIN_FILENO, &stdin_ev) < 0) {
- log_error("Failed to register STDIN in epoll: %m");
- return -errno;
- }
- }
+ 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)) {
- zero(stdout_ev);
- stdout_ev.events = EPOLLOUT|EPOLLET;
- stdout_ev.data.fd = STDOUT_FILENO;
+ if (f->stdin_readable && f->in_buffer_full < LINE_MAX) {
- zero(master_ev);
- master_ev.events = EPOLLIN|EPOLLOUT|EPOLLET;
- master_ev.data.fd = master;
+ k = read(STDIN_FILENO, f->in_buffer + f->in_buffer_full, LINE_MAX - f->in_buffer_full);
+ if (k < 0) {
- zero(signal_ev);
- signal_ev.events = EPOLLIN;
- signal_ev.data.fd = signal_fd;
+ if (errno == EAGAIN)
+ f->stdin_readable = false;
+ else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) {
+ f->stdin_readable = false;
+ f->stdin_hangup = true;
- if (epoll_ctl(ep, EPOLL_CTL_ADD, STDOUT_FILENO, &stdout_ev) < 0) {
- if (errno != EPERM) {
- log_error("Failed to register stdout in epoll: %m");
- return -errno;
+ f->stdin_event_source = sd_event_source_unref(f->stdin_event_source);
+ } else {
+ log_error("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;
+ }
}
- /* 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");
- return -errno;
- }
-
- for (;;) {
- struct epoll_event ev[16];
- ssize_t k;
- int i, nfds;
+ if (f->master_writable && f->in_buffer_full > 0) {
- nfds = epoll_wait(ep, ev, ELEMENTSOF(ev), quit ? 0 : -1);
- if (nfds < 0) {
+ k = write(f->master, f->in_buffer, f->in_buffer_full);
+ if (k < 0) {
- if (errno == EINTR || errno == EAGAIN)
- continue;
+ 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;
- log_error("epoll_wait(): %m");
- return -errno;
+ f->master_event_source = sd_event_source_unref(f->master_event_source);
+ } else {
+ log_error("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 (nfds == 0)
- return 0;
-
- 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;
+ if (f->master_readable && f->out_buffer_full < LINE_MAX) {
- } else if (ev[i].data.fd == master) {
+ k = read(f->master, f->out_buffer + f->out_buffer_full, LINE_MAX - f->out_buffer_full);
+ if (k < 0) {
- if (ev[i].events & (EPOLLIN|EPOLLHUP))
- master_readable = true;
+ /* Note that EIO on the master device
+ * might be cause by vhangup() or
+ * temporary closing of everything on
+ * the other side, we treat it like
+ * EAGAIN here and try again. */
- if (ev[i].events & (EPOLLOUT|EPOLLHUP))
- master_writable = true;
+ if (errno == EAGAIN || errno == EIO)
+ f->master_readable = false;
+ else if (errno == EPIPE || errno == ECONNRESET) {
+ f->master_readable = f->master_writable = false;
+ f->master_hangup = true;
- } else if (ev[i].data.fd == signal_fd)
- process_signalfd = true;
- }
-
- 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)
- stdin_readable = false;
- else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) {
- stdin_readable = false;
- stdin_hangup = true;
- epoll_ctl(ep, EPOLL_CTL_DEL, STDIN_FILENO, NULL);
- } else {
- log_error("read(): %m");
- return -errno;
- }
+ f->master_event_source = sd_event_source_unref(f->master_event_source);
} else {
- /* Check if ^] has been
- * pressed three times within
- * one second. If we get this
- * we quite immediately. */
- if (look_for_escape(&escape_timestamp, &escape_counter, in_buffer + in_buffer_full, k))
- return !quit;
-
- in_buffer_full += (size_t) k;
+ log_error("read(): %m");
+ return sd_event_exit(f->event, EXIT_FAILURE);
}
- }
-
- if (master_writable && in_buffer_full > 0) {
+ } else
+ f->out_buffer_full += (size_t) k;
+ }
- k = write(master, in_buffer, in_buffer_full);
- if (k < 0) {
+ if (f->stdout_writable && f->out_buffer_full > 0) {
- if (errno == EAGAIN || errno == EIO)
- master_writable = false;
- else if (errno == EPIPE || errno == ECONNRESET) {
- master_writable = master_readable = false;
- master_hangup = true;
- epoll_ctl(ep, EPOLL_CTL_DEL, master, NULL);
- } else {
- log_error("write(): %m");
- return -errno;
- }
+ 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 {
- assert(in_buffer_full >= (size_t) k);
- memmove(in_buffer, in_buffer + k, in_buffer_full - k);
- in_buffer_full -= k;
+ log_error("write(): %m");
+ return sd_event_exit(f->event, EXIT_FAILURE);
}
- }
- if (master_readable && out_buffer_full < LINE_MAX) {
-
- k = read(master, out_buffer + out_buffer_full, LINE_MAX - out_buffer_full);
- if (k < 0) {
-
- /* Note that EIO on the master
- * device might be cause by
- * vhangup() or temporary
- * closing of everything on
- * the other side, we treat it
- * like EAGAIN here and try
- * again. */
-
- if (errno == EAGAIN || errno == EIO)
- master_readable = false;
- else if (errno == EPIPE || errno == ECONNRESET) {
- master_readable = master_writable = false;
- master_hangup = true;
- epoll_ctl(ep, EPOLL_CTL_DEL, master, NULL);
- } else {
- log_error("read(): %m");
- return -errno;
- }
- } else
- out_buffer_full += (size_t) k;
+ } else {
+ 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 (stdout_writable && out_buffer_full > 0) {
+ 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);
+ }
- k = write(STDOUT_FILENO, out_buffer, out_buffer_full);
- if (k < 0) {
+ return 0;
+}
- if (errno == EAGAIN)
- stdout_writable = false;
- else if (errno == EIO || errno == EPIPE || errno == ECONNRESET) {
- stdout_writable = false;
- stdout_hangup = true;
- epoll_ctl(ep, EPOLL_CTL_DEL, STDOUT_FILENO, NULL);
- } else {
- log_error("write(): %m");
- return -errno;
- }
+static int on_master_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
+ PTYForward *f = userdata;
- } else {
- assert(out_buffer_full >= (size_t) k);
- memmove(out_buffer, out_buffer + k, out_buffer_full - k);
- out_buffer_full -= k;
- }
- }
+ 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 (process_signalfd) {
- struct signalfd_siginfo sfsi;
- ssize_t n;
+ if (revents & (EPOLLOUT|EPOLLHUP))
+ f->master_writable = true;
- n = read(signal_fd, &sfsi, sizeof(sfsi));
- if (n != sizeof(sfsi)) {
+ return shovel(f);
+}
- if (n >= 0) {
- log_error("Failed to read from signalfd: invalid block size");
- return -EIO;
- }
+static int on_stdin_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
+ PTYForward *f = userdata;
- if (errno != EINTR && errno != EAGAIN) {
- log_error("Failed to read from signalfd: %m");
- return -errno;
- }
- } else {
+ assert(f);
+ assert(e);
+ assert(e == f->stdin_event_source);
+ assert(fd >= 0);
+ assert(fd == STDIN_FILENO);
- if (sfsi.ssi_signo == SIGWINCH) {
- struct winsize ws;
+ if (revents & (EPOLLIN|EPOLLHUP))
+ f->stdin_readable = true;
- /* The window size changed, let's forward that. */
- if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) >= 0)
- ioctl(master, TIOCSWINSZ, &ws);
+ return shovel(f);
+}
- } else if (sfsi.ssi_signo == SIGTERM && kill_pid > 0 && signo > 0 && !tried_orderly_shutdown) {
+static int on_stdout_event(sd_event_source *e, int fd, uint32_t revents, void *userdata) {
+ PTYForward *f = userdata;
- if (kill(kill_pid, signo) < 0)
- quit = true;
- else {
- log_info("Trying to halt container. Send SIGTERM again to trigger immediate termination.");
+ assert(f);
+ assert(e);
+ assert(e == f->stdout_event_source);
+ assert(fd >= 0);
+ assert(fd == STDOUT_FILENO);
- /* This only works for systemd... */
- tried_orderly_shutdown = true;
- }
+ if (revents & (EPOLLOUT|EPOLLHUP))
+ f->stdout_writable = true;
- } else
- /* Signals that where
- * delivered via signalfd that
- * we didn't know are a reason
- * for us to quit */
- quit = true;
- }
- }
+ return shovel(f);
+}
- if (stdin_hangup || stdout_hangup || master_hangup) {
- /* Exit the loop if any side hung up and if
- * there's nothing more to write or nothing we
- * could write. */
+static int on_sigwinch_event(sd_event_source *e, const struct signalfd_siginfo *si, void *userdata) {
+ PTYForward *f = userdata;
+ struct winsize ws;
- if ((out_buffer_full <= 0 || stdout_hangup) &&
- (in_buffer_full <= 0 || master_hangup))
- return !quit;
- }
- }
+ 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)
+ ioctl(f->master, TIOCSWINSZ, &ws);
+
+ return 0;
}
-int process_pty(int master, sigset_t *mask, pid_t kill_pid, int signo) {
- struct termios saved_stdin_attr, raw_stdin_attr;
- struct termios saved_stdout_attr, raw_stdout_attr;
- bool saved_stdin = false;
- bool saved_stdout = false;
+int pty_forward_new(sd_event *event, int master, PTYForward **ret) {
+ _cleanup_(pty_forward_freep) PTYForward *f = NULL;
struct winsize ws;
int r;
+ f = new0(PTYForward, 1);
+ if (!f)
+ return -ENOMEM;
+
+ if (event)
+ f->event = sd_event_ref(event);
+ else {
+ r = sd_event_default(&f->event);
+ if (r < 0)
+ return r;
+ }
+
+ 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)
ioctl(master, TIOCSWINSZ, &ws);
- if (tcgetattr(STDIN_FILENO, &saved_stdin_attr) >= 0) {
- saved_stdin = true;
+ if (tcgetattr(STDIN_FILENO, &f->saved_stdin_attr) >= 0) {
+ struct termios raw_stdin_attr;
- raw_stdin_attr = saved_stdin_attr;
+ f->saved_stdin = true;
+
+ raw_stdin_attr = f->saved_stdin_attr;
cfmakeraw(&raw_stdin_attr);
- raw_stdin_attr.c_oflag = saved_stdin_attr.c_oflag;
+ raw_stdin_attr.c_oflag = f->saved_stdin_attr.c_oflag;
tcsetattr(STDIN_FILENO, TCSANOW, &raw_stdin_attr);
}
- if (tcgetattr(STDOUT_FILENO, &saved_stdout_attr) >= 0) {
- saved_stdout = true;
- raw_stdout_attr = saved_stdout_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 = saved_stdout_attr.c_iflag;
- raw_stdout_attr.c_lflag = saved_stdout_attr.c_lflag;
+ 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 = process_pty_loop(master, mask, kill_pid, signo);
+ r = sd_event_add_io(f->event, &f->master_event_source, master, EPOLLIN|EPOLLOUT|EPOLLET, on_master_event, f);
+ if (r < 0)
+ return r;
- if (saved_stdout)
- tcsetattr(STDOUT_FILENO, TCSANOW, &saved_stdout_attr);
- if (saved_stdin)
- tcsetattr(STDIN_FILENO, TCSANOW, &saved_stdin_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_signal(f->event, &f->sigwinch_event_source, SIGWINCH, on_sigwinch_event, f);
+
+ *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 r;
-
+ return NULL;
}