samples: net: sockets: Add HTTP GET example

This example shows usage of client connection and getaddrinfo().

Signed-off-by: Paul Sokolovsky <paul.sokolovsky@linaro.org>

samples/net/sockets/http_get/Makefile

@@ -0,0 +1,18 @@
+# Makefile - simple socket-based HTTP GET example
+
+#
+# Copyright (c) 2017 Linaro Limited
+#
+# SPDX-License-Identifier: Apache-2.0
+#
+
+BOARD ?= qemu_x86
+CONF_FILE ?= prj.conf
+
+include $(ZEPHYR_BASE)/Makefile.inc
+
+ifeq ($(CONFIG_NET_L2_BT), y)
+	QEMU_EXTRA_FLAGS = -serial unix:/tmp/bt-server-bredr
+else
+	include $(ZEPHYR_BASE)/samples/net/common/Makefile.ipstack
+endif

samples/net/sockets/http_get/Makefile.posix

@@ -0,0 +1,4 @@
+# This makefile builds the sample for a POSIX system, like Linux
+
+http_get: src/http_get.c
+	$(CC) $^ -o $@

samples/net/sockets/http_get/README.rst

@@ -0,0 +1,68 @@
+.. _sockets-http-get:
+
+Socket HTTP GET Example
+#######################
+
+Overview
+********
+
+The sockets/http_get sample application for Zephyr implements a simple
+HTTP GET client using a BSD Sockets compatible API. The purpose of this
+sample is to show how it's possible to develop a sockets application
+portable to both POSIX and Zephyr. As such, it is kept minimal and
+supports only IPv4.
+
+The source code for this sample application can be found at:
+:file:`samples/net/sockets/http_get`.
+
+Requirements
+************
+
+- :ref:`networking_with_qemu`
+- or, a board with hardware networking
+- NAT/routing should be set up to allow connections to the Internet
+- DNS server should be available on the host to resolve domain names
+
+Building and Running
+********************
+
+Build the Zephyr version of the application like this:
+
+.. code-block:: console
+
+    $ cd $ZEPHYR_BASE/samples/net/sockets/http_get
+    $ make pristine
+    $ make BOARD=<board_to_use>
+
+``board_to_use`` defaults to ``qemu_x86``. In this case, you can run the
+application in QEMU using ``make run``. If you used another BOARD, you
+will need to consult its documentation for application deployment
+instructions. You can read about Zephyr support for specific boards in
+the documentation at :ref:`boards`.
+
+After the sample starts, it issues HTTP GET request to "google.com:80"
+and dumps the response. You can edit the source code to issue a request
+to any other site on the Internet (or on the local network, in which
+case no NAT/routing setup is needed).
+
+Running application on POSIX Host
+=================================
+
+The same application source code can be built for a POSIX system, e.g.
+Linux. (Note: if you look at the source, you will see that the code is
+the same except the header files are different for Zephyr vs POSIX.)
+
+To build for a host POSIX OS:
+
+.. code-block:: console
+
+    $ make -f Makefile.posix
+
+To run:
+
+.. code-block:: console
+
+    $ ./http_get
+
+As can be seen, the behavior of the application is the same as the Zephyr
+version.

samples/net/sockets/http_get/prj.conf

@@ -0,0 +1,33 @@
+# General config
+CONFIG_NEWLIB_LIBC=y
+
+# Networking config
+CONFIG_NETWORKING=y
+CONFIG_NET_IPV4=y
+CONFIG_NET_IPV6=y
+CONFIG_NET_TCP=y
+CONFIG_NET_SOCKETS=y
+CONFIG_NET_SOCKETS_POSIX_NAMES=y
+
+CONFIG_DNS_RESOLVER=y
+CONFIG_DNS_SERVER_IP_ADDRESSES=y
+CONFIG_DNS_SERVER1="192.0.2.2"
+
+# Network driver config
+CONFIG_TEST_RANDOM_GENERATOR=y
+
+# Without CONFIG_NET_BUF_LOG printf() doesn't work
+CONFIG_NET_BUF_LOG=y
+
+# Network address config
+CONFIG_NET_APP_SETTINGS=y
+CONFIG_NET_APP_NEED_IPV4=y
+CONFIG_NET_APP_MY_IPV4_ADDR="192.0.2.1"
+CONFIG_NET_APP_PEER_IPV4_ADDR="192.0.2.2"
+CONFIG_NET_APP_MY_IPV4_GW="192.0.2.2"
+
+# Network debug config
+CONFIG_NET_LOG=y
+CONFIG_NET_LOG_GLOBAL=y
+CONFIG_SYS_LOG_NET_LEVEL=2
+#CONFIG_NET_DEBUG_SOCKETS=y

samples/net/sockets/http_get/sample.yaml

@@ -0,0 +1,8 @@
+sample:
+    description: BSD Sockets API HTTP GET example
+    name: socket_http_get
+tests:
+-   test:
+        min_ram: 32
+        build_only: true
+        tags: net

samples/net/sockets/http_get/src/Makefile

@@ -0,0 +1,3 @@
+include $(ZEPHYR_BASE)/samples/net/common/Makefile.common
+
+obj-y += http_get.o

samples/net/sockets/http_get/src/http_get.c

@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2017 Linaro Limited
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <stdio.h>
+
+#ifndef __ZEPHYR__
+
+#include <netinet/in.h>
+#include <sys/socket.h>
+#include <arpa/inet.h>
+#include <unistd.h>
+#include <netdb.h>
+
+#else
+
+#include <net/socket.h>
+#include <kernel.h>
+#include <net/net_app.h>
+
+#endif
+
+#define SSTRLEN(s) (sizeof(s) - 1)
+#define CHECK(r) { if (r == -1) { printf("Error: " #r "\n"); } }
+
+#define REQUEST "GET / HTTP/1.0\r\n\r\n"
+
+static char response[1024];
+
+void dump_addrinfo(const struct addrinfo *ai)
+{
+	printf("addrinfo @%p: fam=%d, socktype=%d, proto=%d, "
+	       "addr_fam=%d, addr_port=%x\n",
+	       ai, ai->ai_family, ai->ai_socktype, ai->ai_protocol,
+	       ai->ai_addr->sa_family,
+	       ((struct sockaddr_in *)ai->ai_addr)->sin_port);
+}
+
+int main(void)
+{
+	static struct addrinfo hints;
+	struct addrinfo *res;
+	int st, sock;
+
+	hints.ai_family = AF_INET;
+	hints.ai_socktype = SOCK_STREAM;
+	st = getaddrinfo("google.com", "80", &hints, &res);
+	printf("getaddrinfo status: %d\n", st);
+
+	if (st != 0) {
+		printf("Unable to resolve address, quitting\n");
+		return 1;
+	}
+
+#if 0
+	for (; res; res = res->ai_next) {
+		dump_addrinfo(res);
+	}
+#endif
+
+	dump_addrinfo(res);
+
+	sock = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
+	CHECK(sock);
+	printf("sock = %d\n", sock);
+	CHECK(connect(sock, res->ai_addr, res->ai_addrlen));
+	send(sock, REQUEST, SSTRLEN(REQUEST), 0);
+
+	printf("Response:\n");
+
+	while (1) {
+		int len = recv(sock, response, sizeof(response) - 1, 0);
+
+		if (len < 0) {
+			printf("Error reading response\n");
+			return 1;
+		}
+
+		if (len == 0) {
+			break;
+		}
+
+		response[len] = 0;
+		printf("%s", response);
+	}
+
+	return 0;
+}