From 804de7cec2dadf8f4dd364cc162a2d3530245c86 Mon Sep 17 00:00:00 2001
From: Travis Geiselbrecht <travisg@gmail.com>
Date: Fri, 28 May 2021 17:17:01 -0700
Subject: [PATCH] WIP telnetd

---
 app/telnetd/rules.mk                         | 12 ++++
 app/telnetd/telnetd.cpp                      | 72 ++++++++++++++++++++
 project/qemu-virt-riscv64-supervisor-test.mk |  2 +-
 project/virtual/inetapps.mk                  |  8 +++
 project/virtual/minip.mk                     |  4 +-
 5 files changed, 94 insertions(+), 4 deletions(-)
 create mode 100644 app/telnetd/rules.mk
 create mode 100644 app/telnetd/telnetd.cpp
 create mode 100644 project/virtual/inetapps.mk

diff --git a/app/telnetd/rules.mk b/app/telnetd/rules.mk
new file mode 100644
index 00000000..2252ec7f
--- /dev/null
+++ b/app/telnetd/rules.mk
@@ -0,0 +1,12 @@
+LOCAL_DIR := $(GET_LOCAL_DIR)
+
+MODULE := $(LOCAL_DIR)
+
+MODULE_SRCS += $(LOCAL_DIR)/telnetd.cpp
+
+MODULE_DEPS := \
+    lib/cksum \
+    lib/libcpp \
+    lib/minip
+
+include make/module.mk
diff --git a/app/telnetd/telnetd.cpp b/app/telnetd/telnetd.cpp
new file mode 100644
index 00000000..1d418146
--- /dev/null
+++ b/app/telnetd/telnetd.cpp
@@ -0,0 +1,72 @@
+/*
+ * Copyright (c) 2014 Travis Geiselbrecht
+ *
+ * Use of this source code is governed by a MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT
+ */
+#include <app.h>
+#include <lk/err.h>
+#include <lk/debug.h>
+#include <lk/trace.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <lk/compiler.h>
+#include <kernel/thread.h>
+#include <lib/minip.h>
+#include <lib/tftp.h>
+#include <lib/cksum.h>
+#include <platform.h>
+
+#define LOCAL_TRACE 1
+
+static int telnet_worker(void *arg) {
+    tcp_socket_t *s = static_cast<tcp_socket_t *>(arg);
+
+    char buf[128];
+    for (;;) {
+        ssize_t err = tcp_read(s, buf, sizeof(buf));
+        if (err < 0) {
+            printf("TELENT: error from read, exiting\n");
+            return err;
+        }
+
+        hexdump8(buf, err);
+    }
+
+    return 0;
+}
+
+static void telnetd_entry(const struct app_descriptor *app, void *args) {
+    printf("TELNET: waiting for network configuration\n");
+    minip_wait_for_configured(INFINITE_TIME);
+    printf("TELNET: starting telnet server\n");
+
+    // starting telnet stack
+    tcp_socket_t *listen_socket;
+    status_t err = tcp_open_listen(&listen_socket, 23);
+    if (err < 0) {
+        printf("tcp_open_listen returns %d\n", err);
+    }
+
+    for (;;) {
+        tcp_socket_t *accept_socket;
+
+        err = tcp_accept(listen_socket, &accept_socket);
+        LTRACEF("tcp_accept returns returns %d, handle %p\n", err, accept_socket);
+        if (err < 0) {
+            TRACEF("error accepting socket, retrying\n");
+            continue;
+        }
+
+        printf("TELNET: starting worker\n");
+        thread_detach_and_resume(thread_create("chargen_worker", &telnet_worker, accept_socket, DEFAULT_PRIORITY, DEFAULT_STACK_SIZE));
+    }
+}
+
+APP_START(inetsrv)
+.init = nullptr,
+.entry = telnetd_entry,
+.flags = 0,
+.stack_size = 0,
+APP_END
diff --git a/project/qemu-virt-riscv64-supervisor-test.mk b/project/qemu-virt-riscv64-supervisor-test.mk
index a2e9a1a7..b16ae7cf 100644
--- a/project/qemu-virt-riscv64-supervisor-test.mk
+++ b/project/qemu-virt-riscv64-supervisor-test.mk
@@ -7,6 +7,6 @@ RISCV_MODE := supervisor
 
 include project/virtual/test.mk
 include project/virtual/fs.mk
-include project/virtual/minip.mk
+include project/virtual/inetapps.mk
 include project/target/qemu-virt-riscv.mk
 
diff --git a/project/virtual/inetapps.mk b/project/virtual/inetapps.mk
new file mode 100644
index 00000000..6eb42b8a
--- /dev/null
+++ b/project/virtual/inetapps.mk
@@ -0,0 +1,8 @@
+# some internet apps that depend on minip
+
+MODULES += \
+    app/inetsrv \
+    app/irc \
+    app/telnetd \
+
+include project/virtual/minip.mk
diff --git a/project/virtual/minip.mk b/project/virtual/minip.mk
index 8654fccc..46b8f072 100644
--- a/project/virtual/minip.mk
+++ b/project/virtual/minip.mk
@@ -1,6 +1,4 @@
 # modules related to the minip stack
 
 MODULES += \
-    lib/minip \
-    app/inetsrv
-
+    lib/minip