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/* Feel free to use this example code in any way
you see fit (Public Domain) */
#include <sys/types.h>
#ifndef _WIN32
#include <sys/select.h>
#include <sys/socket.h>
#else
#include <winsock2.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <microhttpd.h>
#if defined(_MSC_VER) && _MSC_VER + 0 <= 1800
/* Substitution is OK while return value is not used */
#define snprintf _snprintf
#endif
#define PORT 8888
#define POSTBUFFERSIZE 512
#define MAXCLIENTS 2
enum ConnectionType
{
GET = 0,
POST = 1
};
static unsigned int nr_of_uploading_clients = 0;
/**
* Information we keep per connection.
*/
struct connection_info_struct
{
enum ConnectionType connectiontype;
/**
* Handle to the POST processing state.
*/
struct MHD_PostProcessor *postprocessor;
/**
* File handle where we write uploaded data.
*/
FILE *fp;
/**
* HTTP response body we will return, NULL if not yet known.
*/
const char *answerstring;
/**
* HTTP status code we will return, 0 for undecided.
*/
unsigned int answercode;
};
#define ASKPAGE \
"<html><body>\n" \
"Upload a file, please!<br>\n" \
"There are %u clients uploading at the moment.<br>\n" \
"<form action=\"/filepost\" method=\"post\" enctype=\"multipart/form-data\">\n" \
"<input name=\"file\" type=\"file\">\n" \
"<input type=\"submit\" value=\" Send \"></form>\n" \
"</body></html>"
static const char *busypage =
"<html><body>This server is busy, please try again later.</body></html>";
static const char *completepage =
"<html><body>The upload has been completed.</body></html>";
static const char *errorpage =
"<html><body>This doesn't seem to be right.</body></html>";
static const char *servererrorpage =
"<html><body>Invalid request.</body></html>";
static const char *fileexistspage =
"<html><body>This file already exists.</body></html>";
static const char *fileioerror =
"<html><body>IO error writing to disk.</body></html>";
static const char *const postprocerror =
"<html><head><title>Error</title></head><body>Error processing POST data</body></html>";
static enum MHD_Result
send_page (struct MHD_Connection *connection,
const char *page,
unsigned int status_code)
{
enum MHD_Result ret;
struct MHD_Response *response;
response = MHD_create_response_from_buffer_static (strlen (page), page);
if (! response)
return MHD_NO;
if (MHD_YES !=
MHD_add_response_header (response,
MHD_HTTP_HEADER_CONTENT_TYPE,
"text/html"))
{
fprintf (stderr,
"Failed to set content type header!\n");
}
ret = MHD_queue_response (connection,
status_code,
response);
MHD_destroy_response (response);
return ret;
}
static enum MHD_Result
iterate_post (void *coninfo_cls,
enum MHD_ValueKind kind,
const char *key,
const char *filename,
const char *content_type,
const char *transfer_encoding,
const char *data,
uint64_t off,
size_t size)
{
struct connection_info_struct *con_info = coninfo_cls;
FILE *fp;
(void) kind; /* Unused. Silent compiler warning. */
(void) content_type; /* Unused. Silent compiler warning. */
(void) transfer_encoding; /* Unused. Silent compiler warning. */
(void) off; /* Unused. Silent compiler warning. */
if (0 != strcmp (key, "file"))
{
con_info->answerstring = servererrorpage;
con_info->answercode = MHD_HTTP_BAD_REQUEST;
return MHD_YES;
}
if (! con_info->fp)
{
if (0 != con_info->answercode) /* something went wrong */
return MHD_YES;
if (NULL != (fp = fopen (filename, "rb")))
{
fclose (fp);
con_info->answerstring = fileexistspage;
con_info->answercode = MHD_HTTP_FORBIDDEN;
return MHD_YES;
}
/* NOTE: This is technically a race with the 'fopen()' above,
but there is no easy fix, short of moving to open(O_EXCL)
instead of using fopen(). For the example, we do not care. */
con_info->fp = fopen (filename, "ab");
if (! con_info->fp)
{
con_info->answerstring = fileioerror;
con_info->answercode = MHD_HTTP_INTERNAL_SERVER_ERROR;
return MHD_YES;
}
}
if (size > 0)
{
if (! fwrite (data, sizeof (char), size, con_info->fp))
{
con_info->answerstring = fileioerror;
con_info->answercode = MHD_HTTP_INTERNAL_SERVER_ERROR;
return MHD_YES;
}
}
return MHD_YES;
}
static void
request_completed (void *cls,
struct MHD_Connection *connection,
void **req_cls,
enum MHD_RequestTerminationCode toe)
{
struct connection_info_struct *con_info = *req_cls;
(void) cls; /* Unused. Silent compiler warning. */
(void) connection; /* Unused. Silent compiler warning. */
(void) toe; /* Unused. Silent compiler warning. */
if (NULL == con_info)
return;
if (con_info->connectiontype == POST)
{
if (NULL != con_info->postprocessor)
{
MHD_destroy_post_processor (con_info->postprocessor);
nr_of_uploading_clients--;
}
if (con_info->fp)
fclose (con_info->fp);
}
free (con_info);
*req_cls = NULL;
}
static enum MHD_Result
answer_to_connection (void *cls,
struct MHD_Connection *connection,
const char *url,
const char *method,
const char *version,
const char *upload_data,
size_t *upload_data_size,
void **req_cls)
{
(void) cls; /* Unused. Silent compiler warning. */
(void) url; /* Unused. Silent compiler warning. */
(void) version; /* Unused. Silent compiler warning. */
if (NULL == *req_cls)
{
/* First call, setup data structures */
struct connection_info_struct *con_info;
if (nr_of_uploading_clients >= MAXCLIENTS)
return send_page (connection,
busypage,
MHD_HTTP_SERVICE_UNAVAILABLE);
con_info = malloc (sizeof (struct connection_info_struct));
if (NULL == con_info)
return MHD_NO;
con_info->answercode = 0; /* none yet */
con_info->fp = NULL;
if (0 == strcmp (method, MHD_HTTP_METHOD_POST))
{
con_info->postprocessor =
MHD_create_post_processor (connection,
POSTBUFFERSIZE,
&iterate_post,
(void *) con_info);
if (NULL == con_info->postprocessor)
{
free (con_info);
return MHD_NO;
}
nr_of_uploading_clients++;
con_info->connectiontype = POST;
}
else
{
con_info->connectiontype = GET;
}
*req_cls = (void *) con_info;
return MHD_YES;
}
if (0 == strcmp (method, MHD_HTTP_METHOD_GET))
{
/* We just return the standard form for uploads on all GET requests */
char buffer[1024];
snprintf (buffer,
sizeof (buffer),
ASKPAGE,
nr_of_uploading_clients);
return send_page (connection,
buffer,
MHD_HTTP_OK);
}
if (0 == strcmp (method, MHD_HTTP_METHOD_POST))
{
struct connection_info_struct *con_info = *req_cls;
if (0 != *upload_data_size)
{
/* Upload not yet done */
if (0 != con_info->answercode)
{
/* we already know the answer, skip rest of upload */
*upload_data_size = 0;
return MHD_YES;
}
if (MHD_YES !=
MHD_post_process (con_info->postprocessor,
upload_data,
*upload_data_size))
{
con_info->answerstring = postprocerror;
con_info->answercode = MHD_HTTP_INTERNAL_SERVER_ERROR;
}
*upload_data_size = 0;
return MHD_YES;
}
/* Upload finished */
if (NULL != con_info->fp)
{
fclose (con_info->fp);
con_info->fp = NULL;
}
if (0 == con_info->answercode)
{
/* No errors encountered, declare success */
con_info->answerstring = completepage;
con_info->answercode = MHD_HTTP_OK;
}
return send_page (connection,
con_info->answerstring,
con_info->answercode);
}
/* Note a GET or a POST, generate error */
return send_page (connection,
errorpage,
MHD_HTTP_BAD_REQUEST);
}
int
main (void)
{
struct MHD_Daemon *daemon;
daemon = MHD_start_daemon (MHD_USE_INTERNAL_POLLING_THREAD,
PORT, NULL, NULL,
&answer_to_connection, NULL,
MHD_OPTION_NOTIFY_COMPLETED, &request_completed,
NULL,
MHD_OPTION_END);
if (NULL == daemon)
{
fprintf (stderr,
"Failed to start daemon.\n");
return 1;
}
(void) getchar ();
MHD_stop_daemon (daemon);
return 0;
}
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