Akifumi Takahashi / HTTP_SERVER

The library with which to make your mbed a HTTP Server which just reads HTML files in the mbed and sends it to the clients.

Dependents:   httpserversample SIMPLE_WSS

Quote:

This library depends on EthernetInterface class, TCPSocketServer class and TCPSocketConnection class. These classes can be imported at EthernetInterface library. Moreover, the EthernetInterface library depends on the mbed-rtos library, so import it here.

Abstract

This is the library to make a mbed a simple HTTP server. With this library, a mbed can understand only GET requests, and can send clients htm or jpg files as a response.

Handleable Requests:

  • GET

Handleable files:

  • html
  • jpg

Note the length of the Filename

A mbed can handle only 8.3 filename (also called as "short filename" or SFN), such as index.htm (in this case, length of the filename is 5.3).

Sample Code

Running the code below, if your mbed is connected to a network, you can see an IP address of the mbed on your console. (When connecting the mbed to a PC with USB, the baud rate should be 9600)

Hello World

#include "mbed.h"
#include "HTTP_SERVER.h"
int main()
{
    HttpServer httpsvr;
    if(httpsvr.init()){
        if(httpsvr.run() == 0)
            printf("end\r\n");
        else
            printf("error end\r\n");
    }
    return 0;
}

As an example, make a index.htm like below (NOT .html; the reason is referred above) in the mbed, and access to <the IP address>/index.htm with a web browser on your PC or any terminals on the network the mbed is connected to, then you would be able to see the page.

index.htm in mbed

<!DOCTYPE html>
<html>
<head>
<title>mbed http server demo</title>
</head>
<body>
	<h1>Mbed Simple HTTP Server</h1> 
	hello world<br />
	<a href="./index.htm" terget="self">Hyper Link Test</a><br />
</body>
</html>

handlers/ResponseMessenger.cpp

Committer:
aktk
Date:
2018-03-16
Revision:
13:b6dd6ed0060b
Parent:
11:0ee7d100db24

File content as of revision 13:b6dd6ed0060b:

#include "ResponseMessenger.h"

const char ResponseMessenger::http_ver[9] = "HTTP/1.1";
ResponseMessenger::ResponseMessenger()
{
    //  Status-Line
    status_code         = 0;
    reason_phrase[0]    = '\0';
    header_field_buffer[0]='\0';
    //  Response Header
}
ResponseMessenger::~ResponseMessenger()
{
}
int ResponseMessenger::resetHeader()
{
    //  Status-Line
    status_code         = 0;
    reason_phrase[0]    = '\0';
    //  Response Header
    header_field_buffer[0]='\0';
    return 0;
}
int ResponseMessenger::setStatusLine(
    int arg_status_code,
    const char* arg_reason_phrase
)
{
    status_code = arg_status_code;
    strcpy(reason_phrase, arg_reason_phrase);

    //  To be safe on the sage side
    reason_phrase[REASON_PHRASE_SIZE - 1] = '\0';
    //  Send 0 if arg str size is too big, else -1.
    if (strlen(arg_reason_phrase) < REASON_PHRASE_SIZE)
        return 0;
    else
        return -1;
}

int ResponseMessenger::setHeaderField(
    const char* arg_field_name, const char* arg_field_val)
{
    const int nField = 7;
    char registered_field_name[nField][32]= {
        "Connection",
        "Location",
        "Keep-Alive",
        "Content-Type",
        "Upgrade",
        "Sec-WebSocket-Accept",
        "Access-Control-Allow-Origin"
    };
    bool flag = false;
    char header_field_line_buffer[128];
    int  buffer_size = strlen(header_field_buffer);

    for (int i = 0; i < nField; i++) {
        if(strcmp(arg_field_name, registered_field_name[i]) == 0)
            flag = true;
    }
    if(flag) {
        sprintf(header_field_line_buffer, "%s: %s\r\n", arg_field_name, arg_field_val);
        strcat(header_field_buffer, header_field_line_buffer);
        //printf("(RM) header field: \r\n%s\r\n", header_field_buffer);
    }
    //  To be safe on the sage side
    header_field_buffer[HEADER_FIELDS_SIZE - 1] = '\0';
    //  Send 0 if arg str size is too big, else -1.
    if (buffer_size + strlen(arg_field_name) + strlen(arg_field_val) < HEADER_FIELDS_SIZE + 1)
        return 0;
    else
        return -1;
}

int ResponseMessenger::setHeaderField(
    const char* arg_field_name, int arg_field_val)
{
    const int nField = 1;
    char registered_field_name[nField][32]= {
        "Content-Length"
    };
    bool flag = false;
    char header_field_line_buffer[128];
    int  buffer_size = strlen(header_field_buffer);

    for (int i = 0; i < nField; i++) {
        if(strcmp(arg_field_name, registered_field_name[i]) == 0)
            flag = true;
    }
    if(flag) {
        sprintf(header_field_line_buffer, "%s: %d\r\n", arg_field_name, arg_field_val);
        strcat(header_field_buffer, header_field_line_buffer);
        //printf("(RM) header field: \r\n%s\r\n", header_field_buffer);
    }
    //  To be safe on the sage side
    header_field_buffer[HEADER_FIELDS_SIZE - 1] = '\0';
    //  Send 0 if arg str size is too big, else -1.
    if (buffer_size + strlen(arg_field_name) + 10 < HEADER_FIELDS_SIZE + 1)
        return 0;
    else
        return -1;
}

int ResponseMessenger::rmHeaderField(
    const char* arg_field_name)
{
    char* removedLineHead;
    char* removedLineEnd;
    int  buffer_size;
    
    //  Look for the head of the line to want to remove
    removedLineHead = strstr(header_field_buffer, arg_field_name);
    if(removedLineHead == NULL) return -1;
    //  Look for the first "\r\n" which is the end of the line
    removedLineEnd = strstr(removedLineHead, "\r\n");
    removedLineEnd += 3; //pointing next line head or '\0' if the line of the last one.
    buffer_size = strlen(removedLineEnd);
    
    for(int i = 0; i < buffer_size + 1; i++)
        removedLineHead[i] = removedLineEnd[i];
    
    return 0;
}

int  ResponseMessenger::getStatusCode()
{
    return status_code;
}

char ResponseMessenger::sendHTTPResponse(
    TCPSocketConnection &arg_connection)
{
    int err_log  = 0;
    int err_code = 0;
    enum {
        MAX_BUFFER_SIZE = 1024
    };
    char buffer[MAX_BUFFER_SIZE] = "\0";

    //
    //  Header
    //
    printf("(RM) [send]Header\r\n");
    //  Status Line
    sprintf(buffer, "%s %d %s\r\n", http_ver, status_code, reason_phrase);
    buffer[MAX_BUFFER_SIZE - 1] = '\0';
    err_log = arg_connection.send_all(buffer, strlen(buffer));
    if(err_log < 0) err_code = ((err_code << 1) | 1);
    //  Response Header
    err_log = arg_connection.send_all(header_field_buffer, strlen(header_field_buffer));
    if(err_log < 0) err_code = ((err_code << 1) | 1);
    //  Blank line
    err_log = arg_connection.send_all("\r\n", strlen("\r\n"));
    if(err_log < 0) err_code = ((err_code << 1) | 1);
    printf("(RM) [Header has sent]\r\n");
    //return error code
    return err_code << 2;

}

char ResponseMessenger::sendHTTPResponse(
    TCPSocketConnection &arg_connection,
    FileHandler &arg_file)
{
    int err_log  = 0;
    int err_code = 0;
    enum {
        MAX_BUFFER_SIZE = 1024
    };
    signed char buffer[MAX_BUFFER_SIZE];

    //
    //  Header
    //
    err_code = sendHTTPResponse(arg_connection);
    //
    //  Body
    //
    if (arg_file.arrival() && status_code == 200) {
        printf("(RM) [send]Body\r\n");
        do {
            int i = 0;
            do {
                buffer[i++] = arg_file.getc();//return a byte from file ponter, or -1 if EOF or ERROR
            } while ((i < MAX_BUFFER_SIZE - 1) && (buffer[i - 1] != EOF));
            if(buffer[i - 1] == EOF)buffer[i - 1] = '\0';
            buffer[i] = '\0';
            if (!arg_file.hasError()) {
                err_log = arg_connection.send_all((char*)buffer, i);
                //printf("(RM) buffer log: %s",  buffer);
            }
            if (arg_file.hasError()) printf("(RM)---[ERR]---\r\n");
            if (arg_file.atEOF())    printf("(RM)---[EOF]---\r\n");
        } while (!arg_file.atEOF() && !arg_file.hasError());
        printf("(RM) [Body has sent]\r\n");

        if (err_log < 0) err_code = ((err_code) | 2);
        if (!arg_file.hasError())err_code = ((err_code) | 1);
    } else {
        printf("(RM) [No Body]\r\n");
    }
    return (char)err_code;
}