iot: Add HTTP support for Zephyr

This commit adds HTTP message handling support for Zephyr.
So, no network routines are involved at this level.

To add HTTP message handling support for Zephyr, we explored the
following options:

1. Importing an external project and perhaps adapting it to fit our
   requirements.
   The criteria to pick one codebase among all the available projects
   are: licensing, correctness and performance.

2. Writing our own implementation from scratch.

We decided to import an external project instead of implementing our
own parser, mainly due to code maturity and correctness. It could take
more time to obtain a production-ready parser from scratch than adapting
a state-of-art library.

The following is a list of some projects offering similar functionality.

lighttpd (many files)
	* License: revised BSD license
	* Supported: active
	* Comments: this parser can't be integrated to Zephyr due to
	  dependencies that currently are not satisficed by our SDK.

nginx (src/http/ngx_http_parse.c)
	* License: 2-clause BSD-like
	* Supported: very active
	* Comments: this parser can't be integrated to Zephyr due to
	  dependencies that currently are not satisficed by our SDK.

wget (src/http-parse.c)
	* License: GPL 3.0
	* Supported: very active
	* Comments: this code can't be included in Zephyr due to
	  licensing issues

curl (lib/http.c)
	* License: MIT/X derivate, see:
	  https://curl.haxx.se/docs/copyright.html
	* Supported: very active
	* Comment: it must be forked and adapted to run in Zephyr.
	  It is not optimized for low-power devices.

nodejs http-parser (http_parser.c)
	* License: nginx license (2-clause BSD-like) and MIT license
	* Supported: very active
	* Comments: optimized with performance in mind.
	  From https://github.com/nodejs/http-parser: "It does
	  not make any syscalls nor allocations, it does not buffer data,
	  it can be interrupted at anytime. It only requires about 40
	  bytes of data per message stream."

So, nodejs/http-parser looks a very good choice for Zephyr. In this
commit, we integrate nodejs' parser to Zephyr.

Origin: https://github.com/nodejs/http-parser/releases/tag/v2.7.1
        https://github.com/nodejs/http-parser/archive/v2.7.1.tar.gz

NOTE:
	This patch reformats the http_parser files to reduce checkpatch
	warnings. Changes made in this refactoring are available at:
Repo:	https://gitlab.com/santes/http_parser/commits/refactoring1
Commit:	9ccfaa23f1c8438855211fa902ec8e7236b702b1

Jira: ZEP-346
Jira: ZEP-776

Change-Id: I29b1d47f323a5841cd4d0a2afbc2cc83a0f576f0
Signed-off-by: Flavio Santes <flavio.santes@intel.com>

include/iot/http_parser.h

@@ -0,0 +1,325 @@
+/* Copyright Joyent, Inc. and other Node contributors. All rights reserved.
+ *
+ * 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.
+ */
+#ifndef _HTTP_PARSER_H_
+#define _HTTP_PARSER_H_
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* Also update SONAME in the Makefile whenever you change these. */
+#define HTTP_PARSER_VERSION_MAJOR 2
+#define HTTP_PARSER_VERSION_MINOR 7
+#define HTTP_PARSER_VERSION_PATCH 1
+
+#include <sys/types.h>
+#if defined(_WIN32) && !defined(__MINGW32__) && \
+	(!defined(_MSC_VER) || _MSC_VER < 1600) && !defined(__WINE__)
+#include <BaseTsd.h>
+#include <stddef.h>
+typedef __int8 int8_t;
+typedef unsigned __int8 uint8_t;
+typedef __int16 int16_t;
+typedef unsigned __int16 uint16_t;
+typedef __int32 int32_t;
+typedef unsigned __int32 uint32_t;
+typedef __int64 int64_t;
+typedef unsigned __int64 uint64_t;
+#else
+#include <stdint.h>
+#include <stddef.h>
+#endif
+
+/* Maximium header size allowed. If the macro is not defined
+ * before including this header then the default is used. To
+ * change the maximum header size, define the macro in the build
+ * environment (e.g. -DHTTP_MAX_HEADER_SIZE=<value>). To remove
+ * the effective limit on the size of the header, define the macro
+ * to a very large number (e.g. -DHTTP_MAX_HEADER_SIZE=0x7fffffff)
+ */
+#ifndef HTTP_MAX_HEADER_SIZE
+# define HTTP_MAX_HEADER_SIZE (80 * 1024)
+#endif
+
+struct http_parser;
+struct http_parser_settings;
+
+
+/* Callbacks should return non-zero to indicate an error. The parser will
+ * then halt execution.
+ *
+ * The one exception is on_headers_complete. In a HTTP_RESPONSE parser
+ * returning '1' from on_headers_complete will tell the parser that it
+ * should not expect a body. This is used when receiving a response to a
+ * HEAD request which may contain 'Content-Length' or 'Transfer-Encoding:
+ * chunked' headers that indicate the presence of a body.
+ *
+ * Returning `2` from on_headers_complete will tell parser that it should not
+ * expect neither a body nor any futher responses on this connection. This is
+ * useful for handling responses to a CONNECT request which may not contain
+ * `Upgrade` or `Connection: upgrade` headers.
+ *
+ * http_data_cb does not return data chunks. It will be called arbitrarily
+ * many times for each string. E.G. you might get 10 callbacks for "on_url"
+ * each providing just a few characters more data.
+ */
+typedef int (*http_data_cb)(struct http_parser *, const char *at,
+			    size_t length);
+typedef int (*http_cb)(struct http_parser *);
+
+enum http_method {
+	HTTP_DELETE = 0,
+	HTTP_GET = 1,
+	HTTP_HEAD = 2,
+	HTTP_POST = 3,
+	HTTP_PUT = 4,
+	HTTP_CONNECT = 5,
+	HTTP_OPTIONS = 6,
+	HTTP_TRACE = 7,
+	HTTP_COPY = 8,
+	HTTP_LOCK = 9,
+	HTTP_MKCOL = 10,
+	HTTP_MOVE = 11,
+	HTTP_PROPFIND = 12,
+	HTTP_PROPPATCH = 13,
+	HTTP_SEARCH = 14,
+	HTTP_UNLOCK = 15,
+	HTTP_BIND = 16,
+	HTTP_REBIND = 17,
+	HTTP_UNBIND = 18,
+	HTTP_ACL = 19,
+	HTTP_REPORT = 20,
+	HTTP_MKACTIVITY = 21,
+	HTTP_CHECKOUT = 22,
+	HTTP_MERGE = 23,
+	HTTP_MSEARCH = 24,
+	HTTP_NOTIFY = 25,
+	HTTP_SUBSCRIBE = 26,
+	HTTP_UNSUBSCRIBE = 27,
+	HTTP_PATCH = 28,
+	HTTP_PURGE = 29,
+	HTTP_MKCALENDAR = 30,
+	HTTP_LINK = 31,
+	HTTP_UNLINK = 32
+};
+
+enum http_parser_type { HTTP_REQUEST, HTTP_RESPONSE, HTTP_BOTH };
+
+/* Flag values for http_parser.flags field */
+enum flags {
+	F_CHUNKED               = 1 << 0,
+	F_CONNECTION_KEEP_ALIVE = 1 << 1,
+	F_CONNECTION_CLOSE      = 1 << 2,
+	F_CONNECTION_UPGRADE    = 1 << 3,
+	F_TRAILING              = 1 << 4,
+	F_UPGRADE               = 1 << 5,
+	F_SKIPBODY              = 1 << 6,
+	F_CONTENTLENGTH         = 1 << 7
+};
+
+enum http_errno {
+	HPE_OK,
+	HPE_CB_message_begin,
+	HPE_CB_url,
+	HPE_CB_header_field,
+	HPE_CB_header_value,
+	HPE_CB_headers_complete,
+	HPE_CB_body,
+	HPE_CB_message_complete,
+	HPE_CB_status,
+	HPE_CB_chunk_header,
+	HPE_CB_chunk_complete,
+	HPE_INVALID_EOF_STATE,
+	HPE_HEADER_OVERFLOW,
+	HPE_CLOSED_CONNECTION,
+	HPE_INVALID_VERSION,
+	HPE_INVALID_STATUS,
+	HPE_INVALID_METHOD,
+	HPE_INVALID_URL,
+	HPE_INVALID_HOST,
+	HPE_INVALID_PORT,
+	HPE_INVALID_PATH,
+	HPE_INVALID_QUERY_STRING,
+	HPE_INVALID_FRAGMENT,
+	HPE_LF_EXPECTED,
+	HPE_INVALID_HEADER_TOKEN,
+	HPE_INVALID_CONTENT_LENGTH,
+	HPE_UNEXPECTED_CONTENT_LENGTH,
+	HPE_INVALID_CHUNK_SIZE,
+	HPE_INVALID_CONSTANT,
+	HPE_INVALID_INTERNAL_STATE,
+	HPE_STRICT,
+	HPE_PAUSED,
+	HPE_UNKNOWN
+};
+
+/* Get an http_errno value from an http_parser */
+#define HTTP_PARSER_ERRNO(p)            ((enum http_errno) (p)->http_errno)
+
+
+struct http_parser {
+	/** PRIVATE **/
+	unsigned int type : 2;         /* enum http_parser_type */
+	unsigned int flags : 8;		/* F_xxx values from 'flags' enum;
+					 * semi-public
+					 */
+	unsigned int state : 7;        /* enum state from http_parser.c */
+	unsigned int header_state : 7; /* enum header_state from http_parser.c
+					*/
+	unsigned int index : 7;        /* index into current matcher */
+	unsigned int lenient_http_headers : 1;
+
+	uint32_t nread;          /* # bytes read in various scenarios */
+	uint64_t content_length; /* # bytes in body (0 if no Content-Length
+				  * header)
+				  */
+	/** READ-ONLY **/
+	unsigned short http_major;
+	unsigned short http_minor;
+	unsigned int status_code : 16; /* responses only */
+	unsigned int method : 8;       /* requests only */
+	unsigned int http_errno : 7;
+
+	/* 1 = Upgrade header was present and the parser has exited because of
+	 * that.
+	 * 0 = No upgrade header present.
+	 * Should be checked when http_parser_execute() returns in addition to
+	 * error checking.
+	 */
+	unsigned int upgrade : 1;
+
+	/** PUBLIC **/
+	void *data; /* A pointer to get hook to the "connection" or "socket"
+		     * object
+		     */
+};
+
+
+struct http_parser_settings {
+	http_cb      on_message_begin;
+	http_data_cb on_url;
+	http_data_cb on_status;
+	http_data_cb on_header_field;
+	http_data_cb on_header_value;
+	http_cb      on_headers_complete;
+	http_data_cb on_body;
+	http_cb      on_message_complete;
+	/* When on_chunk_header is called, the current chunk length is stored
+	 * in parser->content_length.
+	 */
+	http_cb      on_chunk_header;
+	http_cb      on_chunk_complete;
+};
+
+
+enum http_parser_url_fields {
+	  UF_SCHEMA           = 0
+	, UF_HOST             = 1
+	, UF_PORT             = 2
+	, UF_PATH             = 3
+	, UF_QUERY            = 4
+	, UF_FRAGMENT         = 5
+	, UF_USERINFO         = 6
+	, UF_MAX              = 7
+};
+
+
+/* Result structure for http_parser_parse_url().
+ *
+ * Callers should index into field_data[] with UF_* values iff field_set
+ * has the relevant (1 << UF_*) bit set. As a courtesy to clients (and
+ * because we probably have padding left over), we convert any port to
+ * a uint16_t.
+ */
+struct http_parser_url {
+	uint16_t field_set;           /* Bitmask of (1 << UF_*) values */
+	uint16_t port;                /* Converted UF_PORT string */
+
+	struct {
+		uint16_t off;               /* Offset into buffer in which field
+					     * starts
+					     */
+		uint16_t len;               /* Length of run in buffer */
+	} field_data[UF_MAX];
+};
+
+
+/* Returns the library version. Bits 16-23 contain the major version number,
+ * bits 8-15 the minor version number and bits 0-7 the patch level.
+ * Usage example:
+ *
+ *   unsigned long version = http_parser_version();
+ *   unsigned major = (version >> 16) & 255;
+ *   unsigned minor = (version >> 8) & 255;
+ *   unsigned patch = version & 255;
+ *   printf("http_parser v%u.%u.%u\n", major, minor, patch);
+ */
+unsigned long http_parser_version(void);
+
+void http_parser_init(struct http_parser *parser, enum http_parser_type type);
+
+
+/* Initialize http_parser_settings members to 0
+ */
+void http_parser_settings_init(struct http_parser_settings *settings);
+
+
+/* Executes the parser. Returns number of parsed bytes. Sets
+ * `parser->http_errno` on error.
+ */
+
+int http_parser_execute(struct http_parser *parser,
+			const struct http_parser_settings *settings,
+			const char *data, size_t len);
+
+/* If http_should_keep_alive() in the on_headers_complete or
+ * on_message_complete callback returns 0, then this should be
+ * the last message on the connection.
+ * If you are the server, respond with the "Connection: close" header.
+ * If you are the client, close the connection.
+ */
+int http_should_keep_alive(const struct http_parser *parser);
+
+/* Returns a string version of the HTTP method. */
+const char *http_method_str(enum http_method m);
+
+/* Return a string name of the given error */
+const char *http_errno_name(enum http_errno err);
+
+/* Return a string description of the given error */
+const char *http_errno_description(enum http_errno err);
+
+/* Initialize all http_parser_url members to 0 */
+void http_parser_url_init(struct http_parser_url *u);
+
+/* Parse a URL; return nonzero on failure */
+int http_parser_parse_url(const char *buf, size_t buflen,
+			  int is_connect, struct http_parser_url *u);
+
+/* Pause or un-pause the parser; a nonzero value pauses */
+void http_parser_pause(struct http_parser *parser, int paused);
+
+/* Checks if this is the final chunk of the body. */
+int http_body_is_final(const struct http_parser *parser);
+
+#ifdef __cplusplus
+}
+#endif
+#endif

lib/iot/Kbuild

@@ -1,3 +1,4 @@
 obj-$(CONFIG_ZOAP) += zoap/
 obj-$(CONFIG_DNS_RESOLVER) += dns/
 obj-$(CONFIG_MQTT_LIB) += mqtt/
+obj-$(CONFIG_HTTP_PARSER) += http/

lib/iot/Kconfig

@@ -22,4 +22,6 @@ source "lib/iot/dns/Kconfig"
 
 source "lib/iot/mqtt/Kconfig"
 
+source "lib/iot/http/Kconfig"
+
 endmenu

lib/iot/Makefile

@@ -9,3 +9,7 @@ endif
 ifdef CONFIG_MQTT_LIB
 include $(srctree)/lib/iot/mqtt/Makefile
 endif
+
+ifdef CONFIG_HTTP_PARSER
+include $(srctree)/lib/iot/http/Makefile
+endif

lib/iot/http/Kconfig

@@ -0,0 +1,32 @@
+# Copyright (c) 2016 Intel Corporation
+#
+# Licensed under the Apache License, Version 2.0 (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/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+config HTTP_PARSER
+	bool
+	prompt "HTTP Parser support"
+	default n
+	help
+	This option enables the http_parser library from nodejs.
+	This parser requires some string-related routines commonly
+	provided by a libc implementation. So, MINIMAL_LIBC_EXTENDED
+	can be used here to resolve all the required dependencies.
+
+config HTTP_PARSER_STRICT
+	bool
+	prompt "HTTP strict parsing"
+	default n
+	depends on HTTP_PARSER
+	help
+	This option enables the strict parsing option

lib/iot/http/Makefile

@@ -0,0 +1,3 @@
+ccflags-$(CONFIG_HTTP_PARSER_STRICT) += -DHTTP_PARSER_STRICT
+
+obj-y := http_parser.o

lib/iot/http/README_http_parser

@@ -0,0 +1,11 @@
+HTTP Parser Support in Zephyr
+-----------------------------
+
+The http-parser library* from the nodejs project is a downstream of an
+externally maintained open source project. The original upstream code
+can be found at:
+
+https://github.com/nodejs/http-parser/releases/tag/v2.7.1
+https://github.com/nodejs/http-parser/archive/v2.7.1.tar.gz
+
+* "http-parser" is the project's name, "http_parser" is used in filenames.