Add ctl-client code

Signed-off-by: Jim Ramsay <i.am@jimramsay.com>

include/ctl-client.h

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2022 Jim Ramsay
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#pragma once
+
+#include <stdbool.h>
+
+struct ctl_client;
+
+void ctl_client_debug_log(bool enable);
+
+struct ctl_client* ctl_client_new(const char* socket_path, void* userdata);
+void ctl_client_destroy(struct ctl_client*);
+void* ctl_client_userdata(struct ctl_client*);
+
+
+int ctl_client_run_command(struct ctl_client* self,
+		int argc, char* argv[]);

include/util.h

@@ -16,8 +16,12 @@
 
 #pragma once
 
+#include <sys/types.h>
+
 #define UDIV_UP(a, b) (((a) + (b) - 1) / (b))
 
 extern const char* wayvnc_version;
 
 const char* default_ctl_socket_path();
+
+void advance_read_buffer(char (*buffer)[], size_t* current_len, size_t advance_by);

src/ctl-client.c

@@ -0,0 +1,272 @@
+/*
+ * Copyright (c) 2022 Jim Ramsay
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+ * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+ * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+ * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
+ * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <poll.h>
+#include <jansson.h>
+
+#include "json-ipc.h"
+#include "ctl-client.h"
+#include "ctl-server.h"
+#include "strlcpy.h"
+#include "util.h"
+
+#define WARN(fmt, ...) \
+	fprintf(stderr, "[WARNING] " fmt "\n", ##__VA_ARGS__)
+
+static bool do_debug = false;
+
+#define DEBUG(fmt, ...) \
+	if (do_debug) \
+		fprintf(stderr, "[%s:%d] " fmt "\n", __FILE__, __LINE__, ##__VA_ARGS__);
+
+#define FAILED_TO(action) \
+	WARN("Failed to " action ": %m");
+
+struct ctl_client {
+	void* userdata;
+
+	char read_buffer[512];
+	size_t read_len;
+
+	int fd;
+};
+
+void ctl_client_debug_log(bool enable)
+{
+	do_debug = enable;
+}
+
+struct ctl_client* ctl_client_new(const char* socket_path, void* userdata)
+{
+	if (!socket_path)
+		socket_path = default_ctl_socket_path();
+	struct ctl_client* new = calloc(1, sizeof(*new));
+	new->userdata = userdata;
+
+	struct sockaddr_un addr = {
+		.sun_family = AF_UNIX,
+	};
+
+	if (strlen(socket_path) >= sizeof(addr.sun_path)) {
+		errno = ENAMETOOLONG;
+		FAILED_TO("create unix socket");
+		goto socket_failure;
+	}
+	strcpy(addr.sun_path, socket_path);
+
+	new->fd = socket(AF_UNIX, SOCK_STREAM, 0);
+	if (new->fd < 0) {
+		FAILED_TO("create unix socket");
+		goto socket_failure;
+	}
+
+	if (connect(new->fd, (struct sockaddr*)&addr, sizeof(addr)) != 0) {
+		FAILED_TO("connect to unix socket");
+		goto connect_failure;
+	}
+
+	return new;
+
+connect_failure:
+	close(new->fd);
+socket_failure:
+	free(new);
+	return NULL;
+}
+
+void ctl_client_destroy(struct ctl_client* self)
+{
+	close(self->fd);
+	free(self);
+}
+
+void* ctl_client_userdata(struct ctl_client* self)
+{
+	return self->userdata;
+}
+
+static struct jsonipc_request*	ctl_client_parse_args(struct ctl_client* self,
+		int argc, char* argv[])
+{
+	struct jsonipc_request* request = NULL;
+	const char* method = argv[0];
+	json_t* params = json_object();
+	for (int i = 1; i < argc; ++i) {
+		char* key = argv[i];
+		char* value = NULL;
+		if (key[0] == '-' && key[1] == '-')
+			key += 2;
+		char* delim = strchr(key, '=');
+		if (delim) {
+			*delim = '\0';
+			value = delim + 1;
+		} else if (++i < argc) {
+			value = argv[i];
+		} else {
+			WARN("Argument must be of the format --key=value or --key value");
+			goto failure;
+		}
+		json_object_set_new(params, key, json_string(value));
+	}
+	request = jsonipc_request_new(method, params);
+
+failure:
+	json_decref(params);
+	return request;
+}
+
+static ssize_t ctl_client_send_request(struct ctl_client* self,
+		struct jsonipc_request* request)
+{
+	json_error_t err;
+	json_t* packed = jsonipc_request_pack(request, &err);
+	if (!packed) {
+		WARN("Could not encode json: %s", err.text);
+		return -1;
+	}
+	char buffer[512];
+	int len = json_dumpb(packed, buffer, sizeof(buffer), JSON_COMPACT);
+	json_decref(packed);
+	DEBUG(">> %.*s", len, buffer);
+	return send(self->fd, buffer, len, MSG_NOSIGNAL);
+}
+
+static json_t* json_from_buffer(struct ctl_client* self)
+{
+	if (self->read_len == 0) {
+		DEBUG("Read buffer is empty");
+		errno = ENODATA;
+		return NULL;
+	}
+	json_error_t err;
+	json_t* root = json_loadb(self->read_buffer, self->read_len, 0, &err);
+	if (root) {
+		advance_read_buffer(&self->read_buffer, &self->read_len, err.position);
+	} else if (json_error_code(&err) == json_error_premature_end_of_input) {
+		DEBUG("Awaiting more data");
+		errno = ENODATA;
+	} else {
+		WARN("Json parsing failed: %s", err.text);
+		errno = EINVAL;
+	}
+	return root;
+}
+
+static json_t* read_one_object(struct ctl_client* self, int timeout_ms)
+{
+	json_t* root = json_from_buffer(self);
+	if (root)
+		return root;
+	if (errno != ENODATA)
+		return NULL;
+	struct pollfd pfd = {
+		.fd = self->fd,
+		.events = POLLIN,
+		.revents = 0
+	};
+	while (root == NULL) {
+		int n = poll(&pfd, 1, timeout_ms);
+		if (n == -1) {
+			if (errno == EINTR)
+				continue;
+			WARN("Error waiting for a response: %m");
+			break;
+		} else if (n == 0) {
+			WARN("Timeout waiting for a response");
+			break;
+		}
+		char* readptr = self->read_buffer + self->read_len;
+		size_t remainder = sizeof(self->read_buffer) - self->read_len;
+		n = recv(self->fd, readptr, remainder, 0);
+		if (n == -1) {
+			WARN("Read failed: %m");
+			break;
+		} else if (n == 0) {
+			WARN("Disconnected");
+			errno = ECONNRESET;
+			break;
+		}
+		DEBUG("Read %d bytes", n);
+		DEBUG("<< %.*s", n, readptr);
+		self->read_len += n;
+		root = json_from_buffer(self);
+		if (!root && errno != ENODATA)
+			break;
+	}
+	return root;
+}
+
+static struct jsonipc_response* ctl_client_wait_for_response(struct ctl_client* self)
+{
+	DEBUG("Waiting for a response");
+	json_t* root = read_one_object(self, 1000);
+	if (!root)
+		return NULL;
+	struct jsonipc_error jipc_err = JSONIPC_ERR_INIT;
+	struct jsonipc_response* response = jsonipc_response_parse_new(root,
+			&jipc_err);
+	if (!response) {
+		char* msg = json_dumps(jipc_err.data, JSON_EMBED);
+		WARN("Could not parse json: %s", msg);
+		free(msg);
+	}
+	json_decref(root);
+	jsonipc_error_cleanup(&jipc_err);
+	return response;
+}
+
+static int ctl_client_print_response(struct ctl_client* self,
+		struct jsonipc_response* response)
+{
+	DEBUG("Response code: %d", response->code);
+	if (response->data) {
+		char* data = json_dumps(response->data, JSON_INDENT(4));
+		printf("%s\n", data);
+		free(data);
+	}
+	return response->code;
+}
+
+int ctl_client_run_command(struct ctl_client* self,
+		int argc, char* argv[])
+{
+	int result = -1;
+	struct jsonipc_request*	request = ctl_client_parse_args(self, argc, argv);
+	if (!request)
+		goto parse_failure;
+
+	if (ctl_client_send_request(self, request) < 0)
+		goto send_failure;
+
+	struct jsonipc_response* response = ctl_client_wait_for_response(self);
+	if (!response)
+		goto receive_failure;
+
+	result = ctl_client_print_response(self, response);
+
+	jsonipc_response_destroy(response);
+receive_failure:
+send_failure:
+	jsonipc_request_destroy(request);
+parse_failure:
+	return result;
+}

src/ctl-server.c

@@ -219,16 +219,7 @@ static ssize_t client_read(struct ctl_client* self, struct cmd_response** err)
 	return n;
 }
 
-static void client_advance_buffer(struct ctl_client* self, size_t len)
+static json_t* client_next_object(struct ctl_client* self, struct cmd_response** ierr)
-{
-	size_t remainder = self->read_len - len;
-	if (remainder > 0)
-		memmove(self->read_buffer, self->read_buffer + len, remainder);
-	self->read_len = remainder;
-}
-
-static json_t* client_next_object(struct ctl_client* self,
-		struct cmd_response** ierr)
 {
 	if (self->read_len == 0)
 		return NULL;
@@ -238,7 +229,7 @@ static json_t* client_next_object(struct ctl_client* self,
 			JSON_DISABLE_EOF_CHECK, &err);
 	if (root) {
 		nvnc_log(NVNC_LOG_DEBUG, "<< %.*s", err.position, self->read_buffer);
-		client_advance_buffer(self, err.position);
+		advance_read_buffer(&self->read_buffer, &self->read_len, err.position);
 	} else if (json_error_code(&err) == json_error_premature_end_of_input) {
 		nvnc_trace("Awaiting more data");
 	} else {

src/util.c

@@ -43,3 +43,13 @@ const char* default_ctl_socket_path()
 				"/tmp/wayvncctl-%d", getuid());
 	return buffer;
 }
+
+void advance_read_buffer(char (*buffer)[], size_t* current_len, size_t advance_by)
+{
+	ssize_t remainder = *current_len - advance_by;
+	if (remainder < 0)
+		remainder = 0;
+	else if (remainder > 0)
+		memmove(*buffer, *buffer + advance_by, remainder);
+	*current_len = remainder;
+}