lwip/contrib/examples/httpd/post_example/post_example.c

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/**
* @file
* HTTPD example for simple POST
*/
/*
* Copyright (c) 2017 Simon Goldschmidt
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification,
* are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
* OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
* IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
* OF SUCH DAMAGE.
*
* This file is part of the lwIP TCP/IP stack.
*
* Author: Simon Goldschmidt <goldsimon@gmx.de>
*
*/
#include "lwip/opt.h"
#include "lwip/apps/httpd.h"
#include "lwip/def.h"
#include "lwip/mem.h"
#include <stdio.h>
#include <string.h>
/** define LWIP_HTTPD_EXAMPLE_GENERATEDFILES to 1 to enable this file system */
#ifndef LWIP_HTTPD_EXAMPLE_SIMPLEPOST
#define LWIP_HTTPD_EXAMPLE_SIMPLEPOST 0
#endif
#if LWIP_HTTPD_EXAMPLE_SIMPLEPOST
#if !LWIP_HTTPD_SUPPORT_POST
#error This needs LWIP_HTTPD_SUPPORT_POST
#endif
#define USER_PASS_BUFSIZE 16
static void *current_connection;
static void *valid_connection;
static char last_user[USER_PASS_BUFSIZE];
err_t
httpd_post_begin(void *connection, const char *uri, const char *http_request,
u16_t http_request_len, int content_len, char *response_uri,
u16_t response_uri_len, u8_t *post_auto_wnd)
{
LWIP_UNUSED_ARG(connection);
LWIP_UNUSED_ARG(http_request);
LWIP_UNUSED_ARG(http_request_len);
LWIP_UNUSED_ARG(content_len);
LWIP_UNUSED_ARG(post_auto_wnd);
if (!memcmp(uri, "/login.cgi", 11)) {
if (current_connection != connection) {
current_connection = connection;
valid_connection = NULL;
/* default page is "login failed" */
snprintf(response_uri, response_uri_len, "/loginfail.html");
/* e.g. for large uploads to slow flash over a fast connection, you should
manually update the rx window. That way, a sender can only send a full
tcp window at a time. If this is required, set 'post_aut_wnd' to 0.
We do not need to throttle upload speed here, so: */
*post_auto_wnd = 1;
return ERR_OK;
}
}
return ERR_VAL;
}
err_t
httpd_post_receive_data(void *connection, struct pbuf *p)
{
err_t ret;
LWIP_ASSERT("NULL pbuf", p != NULL);
if (current_connection == connection) {
u16_t token_user = pbuf_memfind(p, "user=", 5, 0);
u16_t token_pass = pbuf_memfind(p, "pass=", 5, 0);
if ((token_user != 0xFFFF) && (token_pass != 0xFFFF)) {
u16_t value_user = token_user + 5;
u16_t value_pass = token_pass + 5;
u16_t len_user = 0;
u16_t len_pass = 0;
u16_t tmp;
/* find user len */
tmp = pbuf_memfind(p, "&", 1, value_user);
if (tmp != 0xFFFF) {
len_user = tmp - value_user;
} else {
len_user = p->tot_len - value_user;
}
/* find pass len */
tmp = pbuf_memfind(p, "&", 1, value_pass);
if (tmp != 0xFFFF) {
len_pass = tmp - value_pass;
} else {
len_pass = p->tot_len - value_pass;
}
if ((len_user > 0) && (len_user < USER_PASS_BUFSIZE) &&
(len_pass > 0) && (len_pass < USER_PASS_BUFSIZE)) {
/* provide contiguous storage if p is a chained pbuf */
char buf_user[USER_PASS_BUFSIZE];
char buf_pass[USER_PASS_BUFSIZE];
char *user = (char *)pbuf_get_contiguous(p, buf_user, sizeof(buf_user), len_user, value_user);
char *pass = (char *)pbuf_get_contiguous(p, buf_pass, sizeof(buf_pass), len_pass, value_pass);
if (user && pass) {
user[len_user] = 0;
pass[len_pass] = 0;
if (!strcmp(user, "lwip") && !strcmp(pass, "post")) {
/* user and password are correct, create a "session" */
valid_connection = connection;
memcpy(last_user, user, sizeof(last_user));
}
}
}
}
/* not returning ERR_OK aborts the connection, so return ERR_OK unless the
connection is unknown */
ret = ERR_OK;
} else {
ret = ERR_VAL;
}
/* this function must ALWAYS free the pbuf it is passed or it will leak memory */
pbuf_free(p);
return ret;
}
void
httpd_post_finished(void *connection, char *response_uri, u16_t response_uri_len)
{
/* default page is "login failed" */
snprintf(response_uri, response_uri_len, "/loginfail.html");
if (current_connection == connection) {
if (valid_connection == connection) {
/* login succeeded */
snprintf(response_uri, response_uri_len, "/session.html");
}
current_connection = NULL;
valid_connection = NULL;
}
}
#endif /* LWIP_HTTPD_EXAMPLE_SIMPLEPOST*/