daemon: interactive terminal (proof-of-concept)

daemon/cmd.c

+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <libknot/internal/mempool.h>
+
+#include "daemon/cmd.h"
+#include "lib/defines.h"
+
+struct cmd {
+	const char *name;
+	int (*cb)(struct worker_ctx *, char *);
+};
+
+static int help(struct worker_ctx *worker, char *args)
+{
+	printf("help:\n    show this help\n");
+	printf("context:\n    show context information\n");
+	printf("load:\n    load module\n");
+	printf("unload:\n    unload module\n");
+
+	struct kr_context *ctx = &worker->resolve;
+	for (unsigned i = 0; i < ctx->mod_loaded; ++i) {
+		struct kr_module *mod = &ctx->modules[i];
+		for (struct kr_prop *p = mod->props; p && p->name; ++p) {
+			printf("%s.%s:\n    %s\n", mod->name, p->name, p->info);
+		}
+	}
+
+	return kr_ok();
+}
+
+static int context(struct worker_ctx *worker, char *args)
+{
+	struct kr_context *ctx = &worker->resolve;
+
+	/* Modules */
+	printf("modules:\n");
+	for (unsigned i = 0; i < ctx->mod_loaded; ++i) {
+		struct kr_module *mod = &ctx->modules[i];
+		printf("    %s\n", mod->name);
+	}
+	/* Options */
+	printf("options: 0x%x\n", ctx->options);
+
+	return kr_ok();
+}
+
+static int mod_load(struct worker_ctx *worker, char *args)
+{
+	struct kr_context *ctx = &worker->resolve;
+	char *saveptr = NULL;
+	char *prop_name = strtok_r(args, " \t\n\r", &saveptr);
+	return kr_context_register(ctx, prop_name);
+}
+
+static int mod_unload(struct worker_ctx *worker, char *args)
+{
+	return kr_error(ENOTSUP);
+}
+
+static int cmd_exec_prop(struct worker_ctx *worker, char *name, char *prop, char *args)
+{
+	struct kr_context *ctx = &worker->resolve;
+
+	for (unsigned i = 0; i < ctx->mod_loaded; ++i) {
+		struct kr_module *mod = &ctx->modules[i];
+		if (strncmp(mod->name, name, strlen(mod->name)) != 0) {
+			continue;
+		}
+		for (struct kr_prop *p = mod->props; p && p->name; ++p) {
+			if (strncmp(p->name, prop, strlen(p->name)) == 0) {
+				auto_free char *res = p->cb(ctx, mod, args);
+				printf("%s\n", res);
+				return kr_ok();
+			}
+		}
+	}
+
+	return kr_error(ENOENT);
+}
+
+int cmd_exec(struct worker_ctx *worker, char *cmd)
+{
+	static struct cmd cmd_table[] = {
+		{ "help", &help },
+		{ "context", &context },
+		{ "load", &mod_load },
+		{ "unload", &mod_unload },
+		{ NULL, NULL }
+	};
+
+	int ret = kr_error(ENOENT);
+	char *args = strchr(cmd, ' ');
+	if (args != NULL) {
+		*args = '\0';
+		args += 1;
+	}
+
+	/* Search builtin namespace. */
+	for (struct cmd *c = cmd_table; c->name; ++c) {
+		if (strncmp(cmd, c->name, strlen(c->name)) == 0) {
+			return c->cb(worker, args);
+		}
+	}
+
+	/* Search module namespace. */
+	char *prop = strchr(cmd, '.');
+	if (prop != NULL) {
+		ret = cmd_exec_prop(worker, cmd, prop + 1, args);
+
+	}
+
+	return ret;
+}
\ No newline at end of file

daemon/cmd.h

+/*  Copyright (C) 2015 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program 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 General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <uv.h>
+#include "daemon/worker.h"
+
+int cmd_exec(struct worker_ctx *worker, char *cmd);
\ No newline at end of file

daemon/kresolved.mk

@@ -2,6 +2,7 @@ kresolved_SOURCES := \
 	daemon/layer/query.c \
 	daemon/udp.c         \
 	daemon/tcp.c         \
+	daemon/cmd.c         \
 	daemon/worker.c      \
 	daemon/main.c
 

daemon/main.c

@@ -23,9 +23,33 @@
 #include <libknot/internal/sockaddr.h>
 #include <libknot/errcode.h>
 
+#include "lib/defines.h"
 #include "lib/resolve.h"
 #include "daemon/udp.h"
 #include "daemon/tcp.h"
+#include "daemon/cmd.h"
+
+static void tty_read(uv_stream_t *stream, ssize_t nread, const uv_buf_t *buf)
+{
+	if (stream && buf && nread > 0) {
+		/* Trim endln */
+		char *cmd = buf->base;
+		cmd[nread - 1] = '\0';
+		/* Execute */
+		int ret = cmd_exec((struct worker_ctx *)stream->data, cmd);
+		if (ret != 0) {
+			printf("ret: %s\n", kr_strerror(ret));
+		}
+	}
+
+	printf("> ");
+	fflush(stdout);
+}
+
+static void tty_alloc(uv_handle_t *handle, size_t suggested, uv_buf_t *buf) {
+    buf->len = suggested;
+    buf->base = malloc(suggested);
+}
 
 void signal_handler(uv_signal_t *handle, int signum)
 {
@@ -124,13 +148,24 @@ int main(int argc, char **argv)
 		ret = tcp_bind((uv_handle_t *)&tcp_sock, &worker, (struct sockaddr *)&addr);
 	}
 
+	/* Allocate TTY */
+	uv_pipe_t pipe;
+	uv_pipe_init(loop, &pipe, 0);
+	uv_pipe_open(&pipe, 0);
+	pipe.data = &worker;
+
 	/* Check results */
 	if (ret != KNOT_EOK) {
 		fprintf(stderr, "[system] bind to '%s' %s\n", addr_str, knot_strerror(ret));
 		ret = EXIT_FAILURE;
 	} else {
+		/* Interactive stdin */
+		if (!feof(stdin)) {
+			printf("[system] started in interactive mode, type 'help'\n");
+			tty_read(NULL, 0, NULL);
+			uv_read_start((uv_stream_t*) &pipe, tty_alloc, tty_read);
+		}
 		/* Run the event loop. */
-		fflush(stdout);
 		ret = uv_run(loop, UV_RUN_DEFAULT);
 	}