Merge pull request #1263 from nyorain/master

Implement get_clipboard ipc message

10 files changed, 574 insertions, 8 deletions

diff --git a/completions/zsh/_swaymsg b/completions/zsh/_swaymsg
index 4207ce3b..1c3ccd65 100644
--- a/completions/zsh/_swaymsg
+++ b/completions/zsh/_swaymsg
@@ -21,6 +21,7 @@ types=(
 'get_marks'
 'get_bar_config'
 'get_version'
+'get_clipboard'
 )
 
 _arguments -s \
diff --git a/include/ipc.h b/include/ipc.h
index 98390335..2b16dc50 100644
--- a/include/ipc.h
+++ b/include/ipc.h
@@ -13,6 +13,7 @@ enum ipc_command_type {
 	IPC_GET_BAR_CONFIG = 6,
 	IPC_GET_VERSION = 7,
 	IPC_GET_INPUTS = 8,
+	IPC_GET_CLIPBOARD = 9,
 	// Events send from sway to clients. Events have the highest bits set.
 	IPC_EVENT_WORKSPACE = ((1<<31) | 0),
 	IPC_EVENT_OUTPUT = ((1<<31) | 1),
diff --git a/include/sway/config.h b/include/sway/config.h
index 999a471a..a05d5ede 100644
--- a/include/sway/config.h
+++ b/include/sway/config.h
@@ -235,8 +235,9 @@ enum ipc_feature {
 	IPC_FEATURE_EVENT_WINDOW = 2048,
 	IPC_FEATURE_EVENT_BINDING = 4096,
 	IPC_FEATURE_EVENT_INPUT = 8192,
+	IPC_FEATURE_GET_CLIPBOARD = 16384,
 
-	IPC_FEATURE_ALL_COMMANDS = 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128,
+	IPC_FEATURE_ALL_COMMANDS = 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 16384,
 	IPC_FEATURE_ALL_EVENTS = 256 | 512 | 1024 | 2048 | 4096 | 8192,
 
 	IPC_FEATURE_ALL = IPC_FEATURE_ALL_COMMANDS | IPC_FEATURE_ALL_EVENTS,
diff --git a/include/util.h b/include/util.h
index e5365458..f68deae8 100644
--- a/include/util.h
+++ b/include/util.h
@@ -3,6 +3,7 @@
 
 #include <stdint.h>
 #include <unistd.h>
+#include <sys/types.h> 
 #include <xkbcommon/xkbcommon.h>
 
 /**
@@ -57,4 +58,8 @@ uint32_t parse_color(const char *color);
  * to a dangling symlink, NULL is returned.
  */
 char* resolve_path(const char* path);
+
+char *b64_encode(const char* binaryData, size_t len, size_t *flen);
+unsigned char *b64_decode(const char *ascii, size_t len, size_t *flen);
+
 #endif
diff --git a/sway/CMakeLists.txt b/sway/CMakeLists.txt
index 61c22b84..48f7a7a8 100644
--- a/sway/CMakeLists.txt
+++ b/sway/CMakeLists.txt
@@ -19,6 +19,7 @@ file(GLOB cmds
 add_executable(sway
 	commands.c
 	${cmds}
+	base64.c
 	config.c
 	container.c
 	criteria.c
@@ -35,7 +36,7 @@ add_executable(sway
 	output.c
 	workspace.c
 	border.c
-    security.c
+	security.c
 )
 
 add_definitions(
diff --git a/sway/base64.c b/sway/base64.c
new file mode 100644
index 00000000..0d51b5c7
--- /dev/null
+++ b/sway/base64.c
@@ -0,0 +1,221 @@
+/*
+ * Adapted from https://github.com/littlstar/b64.c
+ * License under the MIT License:
+ * Copyright (c) 2014 Little Star Media, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <ctype.h>
+#include <stdlib.h>
+#include "util.h"
+
+static const char b64_table[] = {
+	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
+	'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
+	'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
+	'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
+	'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
+	'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
+	'w', 'x', 'y', 'z', '0', '1', '2', '3',
+	'4', '5', '6', '7', '8', '9', '+', '/'
+};
+
+char *b64_encode(const char *src, size_t len, size_t *flen) {
+	int i = 0;
+	int j = 0;
+	char *enc = NULL;
+	size_t size = len * 4 / 3;
+	size_t idx = 0;
+	unsigned char buf[4];
+	char tmp[3];
+
+	// alloc
+	enc = (char *) malloc(size + 1);
+	if (NULL == enc) { return NULL; }
+
+	// parse until end of source
+	while (len--) {
+		// read up to 3 bytes at a time into `tmp'
+		tmp[i++] = *(src++);
+
+		// if 3 bytes read then encode into `buf'
+		if (3 == i) {
+			buf[0] = (tmp[0] & 0xfc) >> 2;
+			buf[1] = ((tmp[0] & 0x03) << 4) + ((tmp[1] & 0xf0) >> 4);
+			buf[2] = ((tmp[1] & 0x0f) << 2) + ((tmp[2] & 0xc0) >> 6);
+			buf[3] = tmp[2] & 0x3f;
+
+			// shouldn't really happen
+			if (idx + 4 > size) {
+				size += 16;
+				enc = (char *) realloc(enc, size + 1);
+			}
+			for (i = 0; i < 4; ++i) {
+				enc[idx++] = b64_table[buf[i]];
+			}
+
+			// reset index
+			i = 0;
+		}
+	}
+
+	// remainder
+	if (i > 0) {
+		// fill `tmp' with `\0' at most 3 times
+		for (j = i; j < 3; ++j) {
+			tmp[j] = '\0';
+		}
+
+		// perform same codec as above
+		buf[0] = (tmp[0] & 0xfc) >> 2;
+		buf[1] = ((tmp[0] & 0x03) << 4) + ((tmp[1] & 0xf0) >> 4);
+		buf[2] = ((tmp[1] & 0x0f) << 2) + ((tmp[2] & 0xc0) >> 6);
+		buf[3] = tmp[2] & 0x3f;
+
+		// perform same write to `enc` with new allocation
+		size_t delta = (i > 3 ? 0 : 3 - i) + (j > i + 1 ? 0 : i + 1 - j);
+		if (idx + delta > size) {
+			size += delta;
+			enc = (char *) realloc(enc, size + 1);
+		}
+		for (j = 0; (j < i + 1); ++j) {
+			enc[idx++] = b64_table[buf[j]];
+		}
+
+		// while there is still a remainder
+		// append `=' to `enc'
+		while ((i++ < 3)) {
+			enc[idx++] = '=';
+		}
+	}
+
+	enc[idx] = '\0';
+
+	if (flen)
+		*flen = size;
+	return enc;
+}
+
+unsigned char *b64_decode(const char *src, size_t len, size_t *decsize) {
+	int i = 0;
+	int j = 0;
+	int l = 0;
+	// max size estimate
+	size_t size = len * 3 / 4;
+	size_t idx = 0;
+	unsigned char *dec = NULL;
+	unsigned char buf[3];
+	unsigned char tmp[4];
+
+	// alloc
+	dec = (unsigned char *) malloc(size + 1);
+	if (NULL == dec) { return NULL; }
+
+	// parse until end of source
+	while (len--) {
+		if (isspace(src[j])) { j++; continue; }
+		// break if char is `=' or not base64 char
+		if ('=' == src[j]) { break; }
+		if (!(isalnum(src[j]) || '+' == src[j] || '/' == src[j])) { break; }
+
+		// read up to 4 bytes at a time into `tmp'
+		tmp[i++] = src[j++];
+
+		// if 4 bytes read then decode into `buf'
+		if (4 == i) {
+			// translate values in `tmp' from table
+			for (i = 0; i < 4; ++i) {
+				// find translation char in `b64_table'
+				for (l = 0; l < 64; ++l) {
+					if (tmp[i] == b64_table[l]) {
+						tmp[i] = l;
+						break;
+					}
+				}
+			}
+
+			// decode
+			buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4);
+			buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2);
+			buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3];
+
+			// unlikely
+			if (idx + 3 > size) {
+				size += 16;
+				dec = (unsigned char *) realloc(dec, size + 1);
+			}
+			if (dec != NULL){
+				for (i = 0; i < 3; ++i) {
+					dec[idx++] = buf[i];
+				}
+			} else {
+				return NULL;
+			}
+
+			// reset
+			i = 0;
+		}
+	}
+
+	// remainder
+	if (i > 0) {
+		// fill `tmp' with `\0' at most 4 times
+		for (j = i; j < 4; ++j) {
+			tmp[j] = '\0';
+		}
+
+		// translate remainder
+		for (j = 0; j < 4; ++j) {
+			// find translation char in `b64_table'
+			for (l = 0; l < 64; ++l) {
+				if (tmp[j] == b64_table[l]) {
+					tmp[j] = l;
+					break;
+				}
+			}
+		}
+
+		// decode remainder
+		buf[0] = (tmp[0] << 2) + ((tmp[1] & 0x30) >> 4);
+		buf[1] = ((tmp[1] & 0xf) << 4) + ((tmp[2] & 0x3c) >> 2);
+		buf[2] = ((tmp[2] & 0x3) << 6) + tmp[3];
+
+		// write remainer decoded buffer to `dec'
+		if (idx + (i - 1) > size) {
+			size += 16;
+			dec = (unsigned char *) realloc(dec, size + 1);
+		}
+		if (dec != NULL){
+			for (j = 0; (j < i - 1); ++j) {
+				dec[idx++] = buf[j];
+			}
+		} else {
+			return NULL;
+		}
+	}
+
+	dec[idx] = '\0';
+	// Return back the size of decoded string if demanded.
+	if (decsize != NULL) {
+		*decsize = size;
+	}
+
+	return dec;
+}
diff --git a/sway/commands/ipc.c b/sway/commands/ipc.c
index f0b3035a..0c678961 100644
--- a/sway/commands/ipc.c
+++ b/sway/commands/ipc.c
@@ -89,6 +89,7 @@ struct cmd_results *cmd_ipc_cmd(int argc, char **argv) {
 		{ "marks", IPC_FEATURE_GET_MARKS },
 		{ "bar-config", IPC_FEATURE_GET_BAR_CONFIG },
 		{ "inputs", IPC_FEATURE_GET_INPUTS },
+		{ "clipboard", IPC_FEATURE_GET_CLIPBOARD },
 	};
 
 	uint32_t type = 0;
diff --git a/sway/ipc-server.c b/sway/ipc-server.c
index 9122d548..4ce2b7eb 100644
--- a/sway/ipc-server.c
+++ b/sway/ipc-server.c
@@ -1,5 +1,6 @@
 // See https://i3wm.org/docs/ipc.html for protocol information
 
+#define _XOPEN_SOURCE 700
 #include <errno.h>
 #include <string.h>
 #include <sys/socket.h>
@@ -59,6 +60,19 @@ struct get_pixels_request {
 	struct wlc_geometry geo;
 };
 
+struct get_clipboard_request {
+	struct ipc_client *client;
+	json_object *json;
+	int fd;
+	struct wlc_event_source *fd_event_source;
+	struct wlc_event_source *timer_event_source;
+	char *type;
+	unsigned int *pending;
+	char *buf;
+	size_t buf_size;
+	size_t buf_position;
+};
+
 struct sockaddr_un *ipc_user_sockaddr(void);
 int ipc_handle_connection(int fd, uint32_t mask, void *data);
 int ipc_client_handle_readable(int client_fd, uint32_t mask, void *data);
@@ -394,6 +408,266 @@ void ipc_get_pixels(wlc_handle output) {
 	ipc_get_pixel_requests = unhandled;
 }
 
+static bool is_text_target(const char *target) {
+	return (strncmp(target, "text/", 5) == 0
+		|| strcmp(target, "UTF8_STRING") == 0
+		|| strcmp(target, "STRING") == 0
+		|| strcmp(target, "TEXT") == 0
+		|| strcmp(target, "COMPOUND_TEXT") == 0);
+}
+
+static void release_clipboard_request(struct get_clipboard_request *req) {
+	if (--(*req->pending) == 0) {
+		const char *str = json_object_to_json_string(req->json);
+		ipc_send_reply(req->client, str, (uint32_t)strlen(str));
+		json_object_put(req->json);
+	}
+
+	free(req->type);
+	free(req->buf);
+	wlc_event_source_remove(req->fd_event_source);
+	wlc_event_source_remove(req->timer_event_source);
+	close(req->fd);
+	free(req);
+}
+
+static int ipc_selection_data_cb(int fd, uint32_t mask, void *data) {
+	assert(data);
+	struct get_clipboard_request *req = (struct get_clipboard_request *)data;
+
+	if (mask & WLC_EVENT_ERROR) {
+		sway_log(L_ERROR, "Selection data fd error");
+		goto error;
+	}
+
+	if (mask & WLC_EVENT_READABLE) {
+		static const unsigned int max_size = 8192 * 1024;
+		int amt = 0;
+
+		do {
+			int size = req->buf_size - req->buf_position;
+			int amt = read(fd, req->buf + req->buf_position, size - 1);
+			if (amt < 0) {
+				if (errno == EAGAIN) {
+					return 0;
+				}
+
+				sway_log_errno(L_INFO, "Failed to read from clipboard data fd");
+				goto release;
+			}
+
+			req->buf_position += amt;
+			if (req->buf_position >= req->buf_size - 1) {
+				if (req->buf_size >= max_size) {
+					sway_log(L_ERROR, "get_clipbard: selection data too large");
+					goto error;
+				}
+				char *next = realloc(req->buf, req->buf_size *= 2);
+				if (!next) {
+					sway_log_errno(L_ERROR, "get_clipboard: realloc data buffer failed");
+					goto error;
+				}
+
+				req->buf = next;
+			}
+		} while(amt != 0);
+
+		req->buf[req->buf_position] = '\0';
+
+		json_object *obj = json_object_new_object();
+		json_object_object_add(obj, "success", json_object_new_boolean(true));
+		if (is_text_target(req->type)) {
+			json_object_object_add(obj, "content", json_object_new_string(req->buf));
+			json_object_object_add(req->json, req->type, obj);
+		} else {
+			size_t outlen;
+			char *b64 = b64_encode(req->buf, req->buf_position, &outlen);
+			json_object_object_add(obj, "content", json_object_new_string(b64));
+			free(b64);
+
+			char *type = malloc(strlen(req->type) + 8);
+			strcat(type, ";base64");
+			json_object_object_add(req->json, type, obj);
+			free(type);
+		}
+	}
+
+	goto release;
+
+error:;
+	json_object *obj = json_object_new_object();
+	json_object_object_add(obj, "success", json_object_new_boolean(false));
+	json_object_object_add(obj, "error",
+		json_object_new_string("Failed to retrieve data"));
+	json_object_object_add(req->json, req->type, obj);
+
+release:
+	release_clipboard_request(req);
+	return 0;
+}
+
+static int ipc_selection_timer_cb(void *data) {
+	assert(data);
+	struct get_clipboard_request *req = (struct get_clipboard_request *)data;
+
+	sway_log(L_INFO, "get_clipbard: timeout for type %s", req->type);
+	json_object *obj = json_object_new_object();
+	json_object_object_add(obj, "success", json_object_new_boolean(false));
+	json_object_object_add(obj, "error", json_object_new_string("Timeout"));
+	json_object_object_add(req->json, req->type, obj);
+
+	release_clipboard_request(req);
+	return 0;
+}
+
+// greedy wildcard (only "*") matching
+bool mime_type_matches(const char *mime_type, const char *pattern) {
+	const char *wildcard = NULL;
+	while (*mime_type && *pattern) {
+		if (*pattern == '*' && !wildcard) {
+			wildcard = pattern;
+			++pattern;
+		}
+
+		if (*mime_type != *pattern) {
+			if (!wildcard)
+				return false;
+
+			pattern = wildcard;
+			++mime_type;
+			continue;
+		}
+
+		++mime_type;
+		++pattern;
+	}
+
+	while (*pattern == '*') {
+		++pattern;
+	}
+
+	return (*mime_type == *pattern);
+}
+
+void ipc_get_clipboard(struct ipc_client *client, char *buf) {
+	size_t size;
+	const char **types = wlc_get_selection_types(&size);
+	if (client->payload_length == 0) {
+		json_object *obj = json_object_new_array();
+		for (size_t i = 0; i < size; ++i) {
+			json_object_array_add(obj, json_object_new_string(types[i]));
+		}
+
+		const char *str = json_object_to_json_string(obj);
+		ipc_send_reply(client, str, strlen(str));
+		json_object_put(obj);
+		return;
+	}
+
+	unescape_string(buf);
+	strip_quotes(buf);
+	list_t *requested = split_string(buf, " ");
+	json_object *json = json_object_new_object();
+	unsigned int *pending = malloc(sizeof(unsigned int));
+	*pending = 0;
+
+	for (size_t l = 0; l < (size_t) requested->length; ++l) {
+		const char *pattern = requested->items[l];
+		bool found = false;
+		for (size_t i = 0; i < size; ++i) {
+			if (!mime_type_matches(types[i], pattern)) {
+				continue;
+			}
+
+			found = true;
+
+			struct get_clipboard_request *req = malloc(sizeof(*req));
+			if (!req) {
+				sway_log(L_ERROR, "get_clipboard: request malloc failed");
+				goto data_error;
+			}
+
+			int pipes[2];
+			if (pipe(pipes) == -1) {
+				sway_log_errno(L_ERROR, "get_clipboard: pipe call failed");
+				free(req);
+				goto data_error;
+			}
+
+			fcntl(pipes[0], F_SETFD, FD_CLOEXEC | O_NONBLOCK);
+			fcntl(pipes[1], F_SETFD, FD_CLOEXEC | O_NONBLOCK);
+
+			if (!wlc_get_selection_data(types[i], pipes[1])) {
+				close(pipes[0]);
+				close(pipes[1]);
+				free(req);
+				sway_log(L_ERROR, "get_clipboard: failed to retrieve "
+					"selection data");
+				goto data_error;
+			}
+
+			if (!(req->buf = malloc(512))) {
+				close(pipes[0]);
+				close(pipes[1]);
+				free(req);
+				sway_log_errno(L_ERROR, "get_clipboard: buf malloc failed");
+				goto data_error;
+			}
+
+			(*pending)++;
+
+			req->client = client;
+			req->type = strdup(types[i]);
+			req->json = json;
+			req->pending = pending;
+			req->buf_position = 0;
+			req->buf_size = 512;
+			req->fd = pipes[0];
+			req->timer_event_source = wlc_event_loop_add_timer(ipc_selection_timer_cb, req);
+			req->fd_event_source = wlc_event_loop_add_fd(pipes[0],
+				WLC_EVENT_READABLE | WLC_EVENT_ERROR | WLC_EVENT_HANGUP,
+				&ipc_selection_data_cb, req);
+
+			wlc_event_source_timer_update(req->timer_event_source, 30000);
+
+			// NOTE: remove this goto to enable retrieving multiple
+			// targets at once. The whole implementation is already
+			// made for it. The only reason it was disabled
+			// at the time of writing is that neither wlc's xselection
+			// implementation nor (apparently) gtk on wayland supports
+			// multiple send requests at the same time which makes
+			// every request except the last one fail (and therefore
+			// return empty data)
+			goto cleanup;
+		}
+
+		if (!found) {
+			sway_log(L_INFO, "Invalid clipboard type %s requested", pattern);
+		}
+	}
+
+	if (*pending == 0) {
+		static const char *error_empty = "{ \"success\": false, \"error\": "
+			"\"No matching types found\" }";
+		ipc_send_reply(client, error_empty, (uint32_t)strlen(error_empty));
+		free(json);
+		free(pending);
+	}
+
+	goto cleanup;
+
+data_error:;
+	static const char *error_json = "{ \"success\": false, \"error\": "
+		"\"Failed to create clipboard data request\" }";
+	ipc_send_reply(client, error_json, (uint32_t)strlen(error_json));
+	free(json);
+	free(pending);
+
+cleanup:
+	list_free(requested);
+	free(types);
+}
+
 void ipc_client_handle_command(struct ipc_client *client) {
 	if (!sway_assert(client != NULL, "client != NULL")) {
 		return;
@@ -638,6 +912,16 @@ void ipc_client_handle_command(struct ipc_client *client) {
 		goto exit_cleanup;
 	}
 
+	case IPC_GET_CLIPBOARD:
+	{
+		if (!(client->security_policy & IPC_FEATURE_GET_CLIPBOARD)) {
+			goto exit_denied;
+		}
+
+		ipc_get_clipboard(client, buf);
+		goto exit_cleanup;
+	}
+
 	default:
 		sway_log(L_INFO, "Unknown IPC command type %i", client->current_command);
 		goto exit_cleanup;
diff --git a/swaymsg/main.c b/swaymsg/main.c
index efd0ec25..2f9cfb14 100644
--- a/swaymsg/main.c
+++ b/swaymsg/main.c
@@ -19,15 +19,17 @@ void sway_terminate(int exit_code) {
 	exit(exit_code);
 }
 
-static void pretty_print_cmd(json_object *r) {
-	bool _success;
+static bool success(json_object *r, bool fallback) {
 	json_object *success;
 	if (!json_object_object_get_ex(r, "success", &success)) {
-		_success = true;
+		return fallback;
 	} else {
-		_success = json_object_get_boolean(success);
+		return json_object_get_boolean(success);
 	}
-	if (!_success) {
+}
+
+static void pretty_print_cmd(json_object *r) {
+	if (!success(r, true)) {
 		json_object *error;
 		if (!json_object_object_get_ex(r, "error", &error)) {
 			printf("An unknkown error occured");
@@ -144,10 +146,43 @@ static void pretty_print_version(json_object *v) {
 	printf("sway version %s\n", json_object_get_string(ver));
 }
 
+static void pretty_print_clipboard(json_object *v) {
+	if (success(v, true)) {
+		if (json_object_is_type(v, json_type_array)) {
+			for (int i = 0; i < json_object_array_length(v); ++i) {
+				json_object *o = json_object_array_get_idx(v, i);
+				printf("%s\n", json_object_get_string(o));
+			}
+		} else {
+			// NOTE: could be extended to print all received types
+			// instead just the first one when sways ipc server
+			// supports it
+			struct json_object_iterator iter = json_object_iter_begin(v);
+			struct json_object_iterator end = json_object_iter_end(v);
+			if (!json_object_iter_equal(&iter, &end)) {
+				json_object *obj = json_object_iter_peek_value(&iter);
+				if (success(obj, false)) {
+					json_object *content;
+					json_object_object_get_ex(obj, "content", &content);
+					printf("%s\n", json_object_get_string(content));
+				} else {
+					json_object *error;
+					json_object_object_get_ex(obj, "error", &error);
+					printf("Error: %s\n", json_object_get_string(error));
+				}
+			}
+		}
+	} else {
+		json_object *error;
+		json_object_object_get_ex(v, "error", &error);
+		printf("Error: %s\n", json_object_get_string(error));
+	}
+}
+
 static void pretty_print(int type, json_object *resp) {
 	if (type != IPC_COMMAND && type != IPC_GET_WORKSPACES &&
 			type != IPC_GET_INPUTS && type != IPC_GET_OUTPUTS &&
-			type != IPC_GET_VERSION) {
+			type != IPC_GET_VERSION && type != IPC_GET_CLIPBOARD) {
 		printf("%s\n", json_object_to_json_string_ext(resp,
 			JSON_C_TO_STRING_PRETTY | JSON_C_TO_STRING_SPACED));
 		return;
@@ -158,6 +193,11 @@ static void pretty_print(int type, json_object *resp) {
 		return;
 	}
 
+	if (type == IPC_GET_CLIPBOARD) {
+		pretty_print_clipboard(resp);
+		return;
+	}
+
 	json_object *obj;
 	size_t len = json_object_array_length(resp);
 	for (size_t i = 0; i < len; ++i) {
@@ -267,6 +307,8 @@ int main(int argc, char **argv) {
 		type = IPC_GET_BAR_CONFIG;
 	} else if (strcasecmp(cmdtype, "get_version") == 0) {
 		type = IPC_GET_VERSION;
+	} else if (strcasecmp(cmdtype, "get_clipboard") == 0) {
+		type = IPC_GET_CLIPBOARD;
 	} else {
 		sway_abort("Unknown message type %s", cmdtype);
 	}
@@ -290,6 +332,9 @@ int main(int argc, char **argv) {
 			printf("%s\n", resp);
 			ret = 1;
 		} else {
+			if (!success(obj, true)) {
+				ret = 1;
+			}
 			if (raw) {
 				printf("%s\n", json_object_to_json_string_ext(obj,
 					JSON_C_TO_STRING_PRETTY | JSON_C_TO_STRING_SPACED));
diff --git a/swaymsg/swaymsg.1.txt b/swaymsg/swaymsg.1.txt
index 1466a0fa..27813588 100644
--- a/swaymsg/swaymsg.1.txt
+++ b/swaymsg/swaymsg.1.txt
@@ -65,6 +65,12 @@ IPC Message Types
 *get_version*::
 	Get JSON-encoded version information for the running instance of sway.
 
+*get_clipboard*::
+	Get JSON-encoded information about the clipboard.
+	Returns the current clipboard mime-types if called without
+	arguments, otherwise returns the clipboard data in the requested
+	formats. Encodes the data using base64 for non-text mime types.
+
 Authors
 -------