Add Wificfg

Uses the sysparam store to save the wifi configuration.
Adds a basic http server for configuration.

extras/wificfg/wificfg.h

@@ -0,0 +1,137 @@
+/*
+ * WiFi configuration via a simple web server.
+ *
+ * Copyright (C) 2016 OurAirQuality.org
+ *
+ * Licensed under the Apache License, Version 2.0, January 2004 (the
+ * "License"); you may not use this file except in compliance with the
+ * License.  You may obtain a copy of the License at
+ *      http://www.apache.org/licenses/
+ *
+ * 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 CONTRIBUTORS 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 WITH THE SOFTWARE.
+ *
+ */
+
+#ifndef __WIFICFG_H__
+#define __WIFICFG_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+ * Printf format used to initialize a default AP ssid. It is passed the last
+ * three bytes of the mac address. This may be NULL to not default the ssid,
+ * but the AP network will not run without a ssid.
+ */
+extern char *wificfg_default_ssid;
+
+/*
+ * A default password for the AP interface. This may be NULL to not default the
+ * password, but the AP network will not run without a password. The minimum
+ * length is 8 characters.
+ */
+extern char *wificfg_default_password;
+
+/*
+ * A default hostname printf format string. This may be NULL to not default the
+ * hostname.
+ */
+extern char *wificfg_default_hostname;
+
+/*
+ * The web server parses the http method string in these enums. The ANY method
+ * is only use for dispatch. The method enum is passed to the handler functions.
+ */
+typedef enum {
+    HTTP_METHOD_GET,
+    HTTP_METHOD_POST,
+    HTTP_METHOD_HEAD,
+    HTTP_METHOD_OTHER,
+    HTTP_METHOD_ANY,
+} wificfg_method;
+
+/*
+ * The web server parses these content-type header values. This is passed to the
+ * dispatch function.
+ */
+typedef enum {
+    HTTP_CONTENT_TYPE_WWW_FORM_URLENCODED,
+    HTTP_CONTENT_TYPE_OTHER
+} wificfg_content_type;
+
+/*
+ * The function signature for the http server request handler functions.
+ *
+ * The buffer, with its length, is usable by the handler.
+ */
+typedef int (* wificfg_handler)(int s, wificfg_method method,
+                                uint32_t content_length,
+                                wificfg_content_type content_type,
+                                char *buf, size_t len);
+
+typedef struct {
+    const char *path;
+    wificfg_method method;
+    wificfg_handler handler;
+    bool secure;
+} wificfg_dispatch;
+
+
+/*
+ * Start the Wifi Configuration http server task. The IP port number
+ * and a path dispatch list are needed. The dispatch list can not be
+ * stack allocated as it is passed to another task.
+ */
+void wificfg_init(uint32_t port, const wificfg_dispatch *dispatch);
+
+/*
+ * Support for reading a form name or value from the socket. The name or value
+ * is truncated to the buffer length. The number of characters read is limited
+ * to the remainder which is updated. The 'valp' flag is set if a value follows.
+ */
+int wificfg_form_name_value(int s, bool *valp, size_t *rem, char *buf, size_t len);
+
+/* Support for form url-encoding decoder. */
+void wificfg_form_url_decode(char *string);
+
+/* Support for html-escaping of form values. */
+void wificfg_html_escape(char *string, char *buf, size_t len);
+
+/* Support for writing a string in a response. */
+int wificfg_write_string(int s, const char *str);
+
+/* Support for writing a string in a response, with chunk transfer encoding.
+ * An optional buffer may be supplied to use to construct a chunk with the
+ * header and trailer, reducing the number of write() calls, and the str may be
+ * at the start of this buffer.
+ */
+int wificfg_write_string_chunk(int s, const char *str, char *buf, size_t len);
+
+/* Write a chunk transfer encoding end marker. */
+int wificfg_write_chunk_end(int s);
+
+/* Write a chunk offset 4 bytes into the buffer. */
+int wificfg_write_buffer_chunk(int s, char *buf);
+
+/* Write a html title meta data, using the hostname or AP SSI. */
+int wificfg_write_html_title(int s, char *buf, size_t len, const char *str);
+
+/* Callback to notify the wificfg logic that a station connection has been
+ * successfully established. It might use this to disable the AP interface after
+ * a restart.
+ */
+void wificfg_got_sta_connect(void);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // __WIFICFG_H__