HTTPD bug fix which is caused by stack overflow.

Dependents:   mbed_controller_demo

Fork of HTTPD by Suga koubou

Original HTTPD implementation of Suga koubou is great but has some bug inside unfortunately. The most critical bug was accessing buffer with the index of out of range like following.

problematic code

char buf[256];

n = httpd->_state[id].client->receive(buf, sizeof(buf));
buf[n] =0;

With above code, it could set buf[256] = 0 when more that 255 data is received. Setting buf[256] causes some other area of memory is corrupted so that system can be predictive status since than.

bug fixed code

n = httpd->_state[id].client->receive(buf, sizeof(buf)-1);
buf[n] =0;
Revision:
0:d18dff347122
Child:
1:a4c4bd58dd3b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/HTTPD.cpp	Wed Nov 13 01:58:04 2013 +0000
@@ -0,0 +1,120 @@
+/* Copyright (C) 2013 Hiroshi Suga, MIT License
+ *
+ * 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 "HTTPD.h"
+
+HTTPD * HTTPD::_inst;
+
+HTTPD::HTTPD () {
+    _inst = this;
+    memset(_state, 0, sizeof(_state));
+    _handler_count = 0;
+}
+
+int HTTPD::start (int port) {
+    int i;
+
+    for (i = 0; i < HTTPD_MAX_CLIENTS; i ++) {
+        _state[i].buf = new CircBuffer<char>(HTTPD_BUF_SIZE);
+        _state[i].thread = new Thread(child, (void*)i, osPriorityNormal, HTTPD_STACK_SIZE);
+        _state[i].client = new TCPSocketConnection;
+    }
+#ifdef HTTPD_ENABLE_CLOSER
+    _state[HTTPD_MAX_CLIENTS].thread = new Thread(closer, (void*)HTTPD_MAX_CLIENTS, osPriorityNormal, 128);
+    _state[HTTPD_MAX_CLIENTS].client = new TCPSocketConnection;
+#endif
+
+    _server.bind(port);
+    _server.listen();
+    _daemon = new Thread(daemon, NULL, osPriorityNormal, 256);
+    return 0;
+}
+
+void HTTPD::daemon (void const *args) {
+    HTTPD *httpd = HTTPD::getInstance();
+    int i, t = 0;
+
+    INFO("Wait for new connection...\r\n");
+    for (;;) {
+        if (t >= 0) {
+            if (httpd->_server.accept(*httpd->_state[t].client) == 0) {
+                INFO("accept %d\r\n", t);
+                httpd->_state[t].thread->signal_set(1);
+            }
+        } else {
+#ifdef HTTPD_ENABLE_CLOSER
+            if (httpd->_server.accept(*httpd->_state[HTTPD_MAX_CLIENTS].client) == 0) {
+                INFO("accept x\r\n");
+                httpd->_state[HTTPD_MAX_CLIENTS].thread->signal_set(1);
+            }
+#endif
+        }
+
+        t = -1;
+        for (i = 0; i < HTTPD_MAX_CLIENTS; i ++) {
+            if (httpd->_state[i].thread->get_state() == Thread::WaitingAnd) {
+                if (t < 0) t = i; // next empty thread
+            }
+        }
+    }
+}
+
+void HTTPD::child (void const *arg) {
+    HTTPD *httpd = HTTPD::getInstance();
+    int id = (int)arg;
+    int i, n;
+    char buf[HTTPD_BUF_SIZE];
+
+    for (;;) {
+        Thread::signal_wait(1);
+
+        httpd->_state[id].mode = MODE_REQUEST;
+        httpd->_state[id].buf->flush();
+        httpd->_state[id].keepalive = 0;
+        INFO("Connection from %s\r\n", httpd->_state[id].client->get_address());
+        httpd->_state[id].client->set_blocking(false, HTTPD_TIMEOUT);
+        for (;;) {
+            if (! httpd->_state[id].client->is_connected()) break;
+
+            n = httpd->_state[id].client->receive(buf, sizeof(buf));
+            if (n < 0) break;
+            buf[n] = 0;
+//            DBG("Recv %d '%s'", n, buf);
+
+            for (i = 0; i < n; i ++) {
+                httpd->recvData(id, buf[i]);
+            }
+        }
+
+        httpd->_state[id].client->close();
+        INFO("Close %s\r\n", httpd->_state[id].client->get_address());
+    }
+}
+
+void HTTPD::closer (void const *arg) {
+    HTTPD *httpd = HTTPD::getInstance();
+    int id = (int)arg;
+
+    for (;;) {
+        Thread::signal_wait(1);
+
+        httpd->_state[id].client->close();
+        INFO("Close %s\r\n", httpd->_state[id].client->get_address());
+    }
+}
+