kexec: Output grabber implementation

klish/ksession/kexec.c

@@ -10,6 +10,7 @@
 
 #include <faux/list.h>
 #include <faux/buf.h>
+#include <faux/eloop.h>
 #include <klish/khelper.h>
 #include <klish/kcontext.h>
 #include <klish/kexec.h>
@@ -184,7 +185,6 @@ bool_t kexec_add(kexec_t *exec, kcontext_t *context)
 }
 
 
-
 static bool_t kexec_prepare(kexec_t *exec)
 {
 	int pipefd[2] = {};
@@ -253,6 +253,179 @@ static bool_t kexec_prepare(kexec_t *exec)
 }
 
 
+typedef struct {
+	int fd_in;
+	int fd_out;
+	faux_buf_t *buf;
+} grabber_stream_t;
+
+typedef enum {
+	IN,
+	OUT
+} direction_t;
+
+
+grabber_stream_t *grabber_stream_new(int fd_in, int fd_out)
+{
+	grabber_stream_t *stream = NULL;
+
+	stream = malloc(sizeof(*stream));
+	assert(stream);
+
+	stream->fd_in = fd_in;
+	stream->fd_out = fd_out;
+	stream->buf = faux_buf_new(0);
+
+	return stream;
+}
+
+
+void grabber_stream_free(grabber_stream_t *stream)
+{
+	if (!stream)
+		return;
+
+	faux_free(stream->buf);
+	faux_free(stream);
+}
+
+
+static bool_t grabber_stop_ev(faux_eloop_t *eloop, faux_eloop_type_e type,
+	void *associated_data, void *user_data)
+{
+	// Happy compiler
+	eloop = eloop;
+	type = type;
+	associated_data = associated_data;
+	user_data = user_data;
+
+	return BOOL_FALSE; // Stop Event Loop
+}
+
+
+static bool_t grabber_fd_ev(faux_eloop_t *eloop, faux_eloop_type_e type,
+	void *associated_data, void *user_data)
+{
+	faux_eloop_info_fd_t *info = (faux_eloop_info_fd_t *)associated_data;
+	faux_list_t *stream_list = (faux_list_t *)user_data;
+	grabber_stream_t *stream = NULL;
+	grabber_stream_t *cur_stream = NULL;
+	direction_t direction = IN;
+	faux_list_node_t *iter = NULL;
+	type = type; // Happy compiler
+
+	iter = faux_list_head(stream_list);
+	while((cur_stream = (grabber_stream_t *)faux_list_each(&iter))) {
+		if (info->fd == cur_stream->fd_in) {
+			direction = IN;
+			stream = cur_stream;
+			break;
+		}
+		if (info->fd == cur_stream->fd_out) {
+			direction = OUT;
+			stream = cur_stream;
+			break;
+		}
+	}
+	if (!stream)
+		return BOOL_FALSE; // Problems
+
+	// Read data
+	if (info->revents & POLLIN) {
+		ssize_t r = 0;
+		size_t total = 0;
+		do {
+			ssize_t len = 0;
+			void *data = NULL;
+			size_t readed = 0;
+			len = faux_buf_dwrite_lock_easy(stream->buf, &data);
+			if (len <= 0)
+				break;
+			r = read(stream->fd_in, data, len);
+			readed = r < 0 ? 0 : r;
+			faux_buf_dwrite_unlock_easy(stream->buf, readed);
+			total += readed;
+		} while (r > 0);
+		if (total > 0)
+			faux_eloop_include_fd_event(eloop, stream->fd_out, POLLOUT);
+	}
+
+	// Write data
+	if (info->revents & POLLOUT) {
+		ssize_t r = 0;
+		ssize_t sent = 0;
+		ssize_t len = 0;
+		do {
+			void *data = NULL;
+			len = faux_buf_dread_lock_easy(stream->buf, &data);
+			if (len <= 0)
+				break;
+			r = write(stream->fd_out, data, len);
+			sent = r < 0 ? 0 : r;
+			faux_buf_dread_unlock_easy(stream->buf, sent);
+		} while (sent == len);
+		if (faux_buf_len(stream->buf) == 0)
+			faux_eloop_exclude_fd_event(eloop, stream->fd_out, POLLOUT);
+	}
+
+	// EOF
+	if (info->revents & POLLHUP) {
+		faux_eloop_del_fd(eloop, info->fd);
+		if (IN == direction)
+			stream->fd_in = -1;
+		else
+			stream->fd_out = -1;
+	}
+
+	iter = faux_list_head(stream_list);
+	while((cur_stream = (grabber_stream_t *)faux_list_each(&iter))) {
+		if (cur_stream->fd_in != -1)
+			return BOOL_TRUE;
+	}
+
+	return BOOL_FALSE;
+}
+
+
+static void grabber(int fds[][2])
+{
+	faux_eloop_t *eloop = NULL;
+	int i = 0;
+	faux_list_t *stream_list = NULL;
+
+	stream_list = faux_list_new(FAUX_LIST_UNSORTED, FAUX_LIST_NONUNIQUE,
+		NULL, NULL, (void (*)(void *))grabber_stream_free);
+
+	eloop = faux_eloop_new(NULL);
+	faux_eloop_add_signal(eloop, SIGINT, grabber_stop_ev, NULL);
+	faux_eloop_add_signal(eloop, SIGTERM, grabber_stop_ev, NULL);
+	faux_eloop_add_signal(eloop, SIGQUIT, grabber_stop_ev, NULL);
+
+	i = 0;
+	while (fds[i][0] != -1) {
+		grabber_stream_t *stream = grabber_stream_new(fds[i][0], fds[i][1]);
+		int fflags = 0;
+
+		faux_list_add(stream_list, stream);
+
+		fflags = fcntl(stream->fd_in, F_GETFL);
+		fcntl(stream->fd_in, F_SETFL, fflags | O_NONBLOCK);
+		fflags = fcntl(stream->fd_out, F_GETFL);
+		fcntl(stream->fd_out, F_SETFL, fflags | O_NONBLOCK);
+
+		faux_eloop_add_fd(eloop, stream->fd_in, POLLIN, grabber_fd_ev, stream_list);
+		faux_eloop_add_fd(eloop, stream->fd_out, 0, grabber_fd_ev, stream_list);
+
+		i++;
+	}
+
+	faux_eloop_loop(eloop);
+	faux_eloop_free(eloop);
+
+	faux_list_free(stream_list);
+}
+
+
 // === SYNC symbol execution
 // The function will be executed right here. It's necessary for
 // navigation implementation for example. To grab function output the
@@ -337,8 +510,17 @@ static bool_t exec_action_sync(kcontext_t *context, const kaction_t *action,
 	close(pipe_stderr[1]);
 
 	{
+		int fds[][2] = {
+			{pipe_stdout[0], kcontext_stdout(context)},
+			{pipe_stderr[0], kcontext_stderr(context)},
+			{-1, -1},
+			};
+		grabber(fds);
 	}
 
+	close(pipe_stdout[0]);
+	close(pipe_stderr[0]);
+
 	_exit(0);
 
 	return BOOL_TRUE;