File content as of revision 16:6ebacf2946d8:

//
// @note Copyright © 2013 by Smartware Computing, all rights reserved.
//     Individuals may use this application for evaluation or non-commercial
//     purposes. Within this restriction, changes may be made to this application
//     as long as this copyright notice is retained. The user shall make
//     clear that their work is a derived work, and not the original.
//     Users of this application and sources accept this application "as is" and
//     shall hold harmless Smartware Computing, for any undesired results while
//     using this application - whether real or imagined.
//
// author David Smart, Smartware Computing
//
#include "mbed.h"
#include "SW_HTTPServer.h"
#include "Utility.h"

#define DEBUG

const char * DEFAULT_FILENAME = "index.htm";

// Header information to always send (must be \r\n terminated)
const char hdr_httpver[] = "HTTP/1.0";                  // typically HTTP/1.0 or HTTP/1.1
const char hdr_age[]     = "Max-age: 0\r\n";            // expires right away
const char hdr_server[]  = "Server: Smart_Server v0.1\r\n"; // Server
const char hdr_dnt[]     = "DNT: 1\r\n";                // Do Not Track
const char hdr_close[]   = "Connection: close\r\n";     // tell the client to close the connection
const char nl[]          = "\r\n";                      // final \r\n for the termination of the header


static const struct {
    char *ext;
    char *filetype;
} extensions [] = {
    {".gif", "Content-Type: image/gif\r\n"          },
    {".jpg", "Content-Type: image/jpeg\r\n"         },
    {".jpeg","Content-Type: image/jpeg\r\n"         },
    {".ico", "Content-Type: image/x-icon\r\n"       },
    {".png", "Content-Type: image/png\r\n"          },
    {".zip", "Content-Type: image/zip\r\n"          },
    {".gz",  "Content-Type: image/gz\r\n"           },
    {".tar", "Content-Type: image/tar\r\n"          },
    {".txt", "Content-Type: plain/text\r\n"         },
    {".pdf", "Content-Type: application/pdf\r\n"    },
    {".htm", "Content-Type: text/html\r\n"          },
    {".html","Content-Type: text/html\r\n"          },
    {0,0}
};

#ifdef DEBUG
// This uses standard library dynamic memory management, but for an
// embedded system there are alternates that may make better sense -
// search the web for embedded system malloc alternates.
static void * MyMalloc(int x, int y)
{
    std::printf("[%04d] malloc(%d)\r\n", y, x);
    return malloc(x);
}
static char toP(void * x)
{
    char * c = (char *) x;
    if (*c >= ' ' && *c < 0x7F)
        return *c;
    else
        return '.';
}
#define mymalloc(x) MyMalloc(x, __LINE__)
#define myfree(x) \
    pc->printf("[%4d] free(%02x %02x %02x %02x %02x ... %c%c%c%c%c)\r\n", __LINE__, \
        *x, *(x+1), *(x+2), *(x+3), *(x+4), \
        toP(x), toP(x+1), toP(x+2), toP(x+3), toP(x+4) ); \
    free(x);
#else
#define mymalloc(x) malloc(x)
#define myfree(x) free(x)
#endif

HTTPServer::HTTPServer(
    Wifly * _wf,
    int port,
    const char * _webroot,
    int maxheaderParams,
    int _maxqueryParams,
    int _maxdynamicpages,
    PC * _pc,
    int _allocforheader,
    int _allocforfile)
{
    wifly = _wf;
    webroot = (char *)malloc(strlen(_webroot)+1);
    strcpy(webroot, _webroot);
    maxqueryParams = _maxqueryParams;
    maxdynamicpages = _maxdynamicpages;
    headerParams = (namevalue *)malloc(maxheaderParams * sizeof(namevalue));
    queryParams = (namevalue *)malloc(maxqueryParams * sizeof(namevalue));
    handlers = (handler *)malloc(maxdynamicpages * sizeof(handler));
    headerbuffersize = _allocforheader;
    headerbuffer = (char *)malloc(headerbuffersize);
    pc = _pc;
    queryType = NULL;
    queryString = NULL;
    postQueryString = NULL;
    queryParamCount = 0;
    handlercount = 0;
    maxheaderbytes = 0;
    server = new TCPSocketServer();
    server->bind(port);
    server->listen();
    server->set_blocking(false, 10);
    ResetPerformanceData();
    PerformanceTimer.start();
}

HTTPServer::~HTTPServer()
{
    int i;

    for (i=0; i<handlercount; i++)
        myfree(handlers[i].path);
    myfree(headerbuffer);
    myfree(handlers);
    myfree(queryParams);
    myfree(webroot);
    webroot = NULL;
}

int HTTPServer::GetMaxHeaderSize()
{
    return maxheaderbytes;
}

bool HTTPServer::RegisterHandler(const char * path, Handler callback)
{
    if (handlercount < maxdynamicpages && path && callback) {
        handlers[handlercount].path = (char *)mymalloc(strlen(path)+1);
        memcpy(handlers[handlercount].path, path, strlen(path)+1);
        handlers[handlercount].callback = callback;
        handlercount++;
        return true;
    } else {
        return false;
    }
}

// Poll()
//
// *OPEN*GET /x=1 HTTP/1.1
// Host: 192.168.1.140
// Connection: keep-alive
// Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
// User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/27.0.1453.94 Safari/537.36
// Accept-Encoding: gzip,deflate,sdch
// Accept-Language: en-US,en;q=0.8
//
void HTTPServer::Poll()
{
    typedef enum {
        Idle,               // waiting for a connection
        Receiving,          // receiving data
        Sending,            // send the response
        WaitingToClose,     // small timeout to close
        Reset
    } state;
    static state op = Idle;
    static char * bPtr = headerbuffer;
    int n;
    static unsigned int t_ref;       // reference point for the PerformanceTimer

#ifdef DEBUG
    static state lastOp = Reset;
    if (lastOp != op) {
        const char *states[] = {"Idle", "Receiving", "Sending", "WaitingToClose", "Reset"};
        pc->printf("Poll: %s\r\n", states[op]);
        lastOp = op;
    }
#endif
    switch(op) {
        default:                    // not expected to arrive here
            op = Idle;
            break;

        case Idle:
            PerformanceTimer.reset();
            bPtr = headerbuffer;
            if (0 == server->accept(client)) {
                op = Receiving;
                t_ref = (unsigned int)PerformanceTimer.read_us();
#ifdef DEBUG
                pc->printf("Accept at %u\r\n", t_ref);
#endif
            }
            break;

        case Receiving:
            n = client.receive(bPtr, headerbuffersize - (bPtr - headerbuffer));
            if (n < 0) {
#ifdef DEBUG
                pc->printf("*** client.receive() => %d\r\n", n);
#endif
            } else if (n) {
                bPtr[n] = '\0';
                if (ParseHeader(headerbuffer)) {
                    op = Sending;
                    t_ref = RecordPerformanceData(&perfData.Header, t_ref);
                }
                bPtr += n;
            }
            break;

        case Sending:
            SendResponse();
            op = WaitingToClose;
            RecordPerformanceData(&perfData.SendData, t_ref);
            break;

        case WaitingToClose:
            close_connection();
            op = Idle;
            break;
    }
}


const char * HTTPServer::GetSupportedType(const char * filename)
{
    int i;
    int buflen = strlen(filename);
    int extlen;

    for (i=0; extensions[i].ext != 0; i++) {
        extlen = strlen(extensions[i].ext);
        if ( !strncmp(&filename[buflen-extlen], extensions[i].ext, extlen)) {
            return extensions[i].filetype;
        }
    }
    return NULL;
}


void HTTPServer::send(const char * msg, int bytes)
{
    if (bytes == -1)
        bytes = strlen(msg);
    wifly->send(msg, bytes);
}


bool HTTPServer::SendFile(const char * filename, const char * filetype)
{
    FILE * fp;

    fp  = fopen(filename,"rb");
    if (fp) { // can open it
        char *fbuffer = (char *)mymalloc(FILESEND_BUF_SIZE);
        int bytes;

        if (fbuffer) {
            header(200, "OK", filetype);
            bytes = fread(fbuffer,sizeof(char),FILESEND_BUF_SIZE,fp);
            while (bytes > 0) {
                send(fbuffer, bytes);
                bytes = fread(fbuffer,sizeof(char),FILESEND_BUF_SIZE,fp);
            }
            myfree(fbuffer);
        } else {
            header(500, "Server Error", "Pragma: err - insufficient memory\r\n");
        }
        fclose(fp);
        return true;
    } else {
        header(404, "Not Found", "Pragma: err - Can't open file\r\n");
        return false;
    }
}

int HTTPServer::HexCharToInt(char c)
{
    if (c >= 'a' && c <= 'f')
        return (c - 'a' + 10);
    else if (c >= 'A' && c <= 'F')
        return (c - 'A' + 10);
    else if (c >= '0' && c <= '9')
        return c - '0';
    else
        return 0;
}

char HTTPServer::HexPairToChar(char * p)
{
    return 16 * HexCharToInt(*p) + HexCharToInt(*(p+1));
}

void HTTPServer::UnescapeString(char * encoded)
{
    char *p;

    // first convert '+' to ' '
    p = strchr(encoded, '+');
    while (p) {
        *p = ' ';
        p = strchr(encoded, '+');
    }
    // then convert hex '%xx' to char 'x'
    p = strchr(encoded, '%');
    while (p) {
        if (strchr("0123456789ABCDEFabcdef", *(p+1))
                && strchr("0123456789ABCDEFabcdef", *(p+2)) ) {
            *p = HexPairToChar(p+1);
            p++;    // advance past the %
            char * a = p;
            char * b = p + 2;
            do {
                *a++ = *b++;
            } while (*b);
            *a = '\0';
        }
        p = strchr(p, '%');
    }
}

const char * HTTPServer::GetParameter(const char * name)
{
    for (int i=0; i<queryParamCount; i++) {
        if (strcmp(queryParams[i].name, name) == 0) {
            return queryParams[i].value;
        }
    }
    return NULL;
}

// this=that&who=what&more=stuff...
// ^   ^    ^
void HTTPServer::ParseParameters(char * pName)
{
    char * pVal;
    char * pNextName;

    // Parse queryParams
    pVal = strchr(pName, '#');      // If there is a '#fragment_id', we can ignore it
    if (pVal)
        *pVal = '\0';
    do {
        queryParams[queryParamCount].name = pName;
        pVal = strchr(pName, '=');
        pNextName = strchr(pName,'&');
        if (pVal) {
            if (pNextName == NULL || (pNextName && pNextName > pVal)) {
                *pVal++ = '\0';
                queryParams[queryParamCount].value = pVal;
                pName = pVal;
            }
        }
        queryParamCount++;
        if (pNextName) {
            pName = pNextName;
            *pName++ = '\0';
        } else {
            pName = NULL;
        }
    } while (pName && queryParamCount < maxqueryParams);
}


bool HTTPServer::GetRemoteAddr(char * str, int strSize)
{
    bool res = false;
    char *p;

    if (strSize < 16) {        // Can only guard it here w/o modifying Wifly class
        *str = '\0';
        return res;
    }
    res = wifly->sendCommand("show z\r", NULL, str, strSize);
    if (res) {
        p = strchr(str, '\n');  // truncate after the octets.
        if (p) *p = '\0';
        p = strchr(str, ' ');   // or a space
        if (p) *p = '\0';
        p = strchr(str, '<');   // or a <
        if (p) *p = '\0';
        res = true;
    }
    wifly->exit();
    return res;
}


void HTTPServer::header(int code, const char * code_text, const char * content_type, const char * optional_text)
{
    char http[100];

    sprintf(http, "%s %i %s\r\n", hdr_httpver, code, code_text);
    send(http);
    send(hdr_age);
    send(hdr_server);
    if (content_type) {
        send(content_type);
    }
    if (optional_text) {
        send(optional_text);
    }
    send(hdr_dnt);
    send(hdr_close);
    send(nl);
}


bool HTTPServer::close_connection()
{
    bool res;

    res = server->close();
#ifdef DEBUG
    pc->printf("close connection returned %d\r\n", res);
#endif
    return res;
}


bool HTTPServer::Extract(char * haystack, char * needle, char ** string)
{
    bool ret = false;       // assume failure until proven otherwise
    char * qs = NULL;
    char * eqs = NULL;
    char * container = NULL;
    char * get = strstr(haystack, needle);    // what if not at the front?
    if (get) {
        // Seems to be a valid "...GET /QueryString HTTP/1.1"
        // or "...<needle>param..."
        qs = get + strlen(needle);  // in case the needle didn't have space delimiters
        while (*qs == ' ')
            qs++;
        // /QueryString\0HTTP/1.1\0\0
        if (*string)            // recycle old string when working a new one
            myfree(*string);
        container = (char *)mymalloc(strlen(qs));
        if (container) {
            strcpy(container, qs);
            eqs = strchr(container, ' ');
            if (eqs)
                *eqs = '\0';
            *string = container;
#ifdef DEBUG
            pc->printf("Extract(%s) = %s\r\n", needle, container);
#endif
            ret = true;
        } else {
            *string = NULL;     // something bad happened... no memory
        }
    }
    return ret;
}


char * HTTPServer::rewriteWithDefaultFile(char * queryString)
{
    char * temp = (char *)mymalloc(strlen(queryString) + strlen(DEFAULT_FILENAME) + 1);

    if (temp) {
        *temp = '\0';
        strcpy(temp, queryString);
        strcat(temp, DEFAULT_FILENAME);
        myfree(queryString);
        return temp;
    } else {
        return queryString;
    }
}


char * HTTPServer::rewritePrependWebroot(char * queryString)
{
    char * temp = (char *)mymalloc(strlen(webroot) + strlen(queryString) + 1);

    if (temp) {
        *temp = '\0';
        strcpy(temp, webroot);
        if (temp[strlen(temp)-1] == '/' && *queryString == '/')
            temp[strlen(temp)-1] = '\0';
        strcat(temp, queryString);
        myfree(queryString);
        return temp;
    } else {
        return queryString;
    }
}


bool HTTPServer::CheckDynamicHandlers()
{
    bool regHandled = false;

    // If this queryString is in the list of registered handlers, call that
    for (int i=0; i<handlercount; i++) {
        if (strcmp(handlers[i].path, queryString) == 0) {
            (*handlers[i].callback)(this, SEND_PAGE, queryString, queryParams, queryParamCount);
            regHandled = true;
            break;      // we only execute the first one
        }
    }
    return regHandled;
}


void HTTPServer::SendResponse()
{
#ifdef DEBUG
    pc->printf("SendResponse(%s) [%d]\r\n", queryType, __LINE__);
#endif
    if (strcmp(queryType, "GET") == 0 ||  strcmp(queryType, "POST") == 0) {
        if (!(queryString[0] == '.' && queryString[1] == '.')) {
            const char * fType;

#ifdef DEBUG
            pc->printf("  SendResponse() [%d]\r\n", __LINE__);
#endif
            if (!CheckDynamicHandlers()) {
                // Otherwise, this queryString must be trying to reference a static file
                if (queryString[strlen(queryString)-1] == '/') {
                    queryString = rewriteWithDefaultFile(queryString);
                }
                // see if we support this file type
                fType = GetSupportedType(queryString);
                if (fType) {
                    queryString = rewritePrependWebroot(queryString);
                    SendFile(queryString, fType);
                } else {
                    //pc->printf("Unsupported file type %s\r\n", queryString);
                    header(404, "Not Found", "Pragma: err - Unsupported type\r\n");
                }
            }
        } else {
            //pc->printf("Unsupported path %s\r\n", queryString);
            header(400, "Bad Request", "Pragma: err - Unsupported path\r\n");
        }
    } else {
        //pc->printf("Unsupported query type %s\r\n", queryType);
        header(400, "Bad Request", "Pragma: err - Unsupported query type\r\n");
    }
    if (queryType) {
        myfree(queryType);
        queryType = NULL;
    }
    if (queryString) {
        myfree(queryString);
        queryString = NULL;
    }
    if (postQueryString) {
        myfree(postQueryString);
        postQueryString = NULL;
    }
}


bool HTTPServer::ParseHeader(char * buffer)
{
    char * dblCR;
    bool advanceState = false;
    int bytecount;

    // Buffer could have partial, but the double \r\n is the key
    //      GET /QueryString?this=that&sky=blue HTTP/1.1\r\n
    //      GET /QueryString HTTP/1.1\r\nHost: 192.168.1.140\r\nCache-Con
    //      GET /QueryString HTTP/1.1\r\nHost: 192.168.1.140\r\nCache-Control: max-age=0\r\n\r\n
    dblCR = strstr(buffer,"\r\n\r\n");
    if (dblCR) {  // Have to scan from the beginning in case split on \r
#ifdef DEBUG
        pc->printf("==\r\n%s==\r\n", buffer);
#endif
        char * soRec = buffer;                  // start of the next record of text
        char * eoRec = strchr(soRec, '\n');     // search for end of the current record

        headerParamCount = 0;
        bytecount = strlen(buffer);
        if (bytecount > maxheaderbytes)
            maxheaderbytes = bytecount;
        while (eoRec) {
            *eoRec = '\0';
            if (*(eoRec-1) == '\r')
                *(eoRec-1) = '\0';
            // Inspect the supported query types (GET, POST) and ignore (HEAD, PUT, OPTION, DELETE, TRACE, CONNECT]
            // This is very clumsy
            if (strstr(soRec, "GET ") == soRec) {
                Extract(soRec, "GET", &queryString);
                if (queryString) {
                    queryType = (char *)mymalloc(strlen("GET")+1);
                    strcpy(queryType, "GET");
                }
            } else if (strstr(soRec, "POST ") == soRec) {
                Extract(soRec, "POST", &queryString);
                if (queryString) {
                    queryType = (char *)mymalloc(strlen("POST")+1);
                    strcpy(queryType, "POST");
                }
            }

            // if there is a ": " delimiter, we have a header item to parse into name,value pair
            // "Connection: keep-alive" becomes "Connection" "keep-alive"
            char *delim = strstr(soRec, ": ");
            char *chkSpace = strchr(soRec, ' ');        // a field-name has no space ahead of the ":"
            if (delim 
            && (!chkSpace || (chkSpace && delim < chkSpace))
            && headerParamCount < maxheaderParams) {
                *delim++ = '\0';        // replace ": " with null
                *delim++ = '\0';
                headerParams[headerParamCount].name = soRec;
                headerParams[headerParamCount].value = delim;
#ifdef DEBUG
                pc->printf("%d: headerParams[%s] = {%s}\r\n", headerParamCount,
                           headerParams[headerParamCount].name, headerParams[headerParamCount].value);
#endif
                headerParamCount++;
            }
            soRec = eoRec + 1;
            eoRec = strchr(soRec, '\n');
        }
        if (queryString) {
            // We have enough to try to reply
#ifdef DEBUG
            pc->printf("create reply queryType{%s}, queryString{%s}\r\n", "GET", queryString);
#endif
            // parse queryParams - if any
            // /file.htm?name1=value1&name2=value2...
            // /file.htm?name1&name2=value2...
            queryParamCount = 0;
            char * paramDelim = strchr(queryString, '?');
            if (paramDelim) {
                *paramDelim++ = '\0';
                UnescapeString(paramDelim);   // everything after the '?'
                ParseParameters(paramDelim);    // pointing at the NULL, but there are queryParams beyond
            }
        } else {
            pc->printf("ERROR: queryString not found in (%s)\r\n", soRec);
        }
        advanceState = true;
        buffer[0] = 0;

        // This part parses the extra data on a POST method.
        // Since there has to be a dynamic handler registered for this
        // it would make sense to move some of this responsibility to
        // that handler. It could then choose if it wanted to allocate
        // the requested 'Content-Length' amount of memory.
        // Should we check the 'Content-Type' to see if it is
        //   'application/x-www-form-urlencoded'?
        int postBytes = atoi(GetHeaderValue("Content-Length"));
        bool acceptIt = false;
        if (strcmp(queryType, "POST") == 0 && postBytes > 0 ) {
            if (postBytes) {
                bool regHandled = false;
                // Registered Dynamic Handler
                // Callback and ask if they want to accept this data
                for (int i=0; i<handlercount; i++) {
                    if (strcmp(handlers[i].path, queryString) == 0) {
                        acceptIt = (*handlers[i].callback)(this, CONTENT_LENGTH_REQUEST, queryString, queryParams, queryParamCount);
                        regHandled = true;
                        break;      // we only execute the first one
                    }
                }

                if (regHandled && acceptIt) {
                    // If so, we'll make space for it
                    postQueryString = (char *)mymalloc(postBytes + 1);
                    if (postQueryString) {
                        char * offset;
                        int len;

                        dblCR += 4;                         // If we slurped up any of the POST,
                        while (*dblCR && *dblCR <= ' ')
                            dblCR++;
                        strcpy(postQueryString, dblCR);     // copy that in and then get the rest
                        while ((len = strlen(postQueryString)) < postBytes) {
                            int n;
                            offset = postQueryString + len;
                            n = client.receive(offset, postBytes - len);
                            if (n >=0) {
                                offset[n] = '\0';
                            }
                        }
                        if (len >= 0) {
                            UnescapeString(postQueryString);
                            ParseParameters(postQueryString);
                        }
                    }
                } else {
                    // Simply copy it to the bitbucket
                    int bytesToDump = postBytes;
                    char * bitbucket = (char *)mymalloc(201);
                    dblCR += 4;
                    while (*dblCR && *dblCR <= ' ')
                        dblCR++;
                    bytesToDump -= strlen(dblCR);
                    while (bytesToDump > 0) {
                        int n = (bytesToDump > 200) ? 200 : bytesToDump;
                        n = client.receive(bitbucket, n);
                        bytesToDump -= n;
                    }
                    myfree(bitbucket);
                }
            }
        }
    }
    return advanceState;
}


const char * HTTPServer::GetHeaderValue(const char * hdr)
{
    int i;
    
    for (i=0; i<headerParamCount; i++)
        {
        if (strcmp(hdr, headerParams[i].name) == 0)
            return headerParams[i].value;
        }
    return NULL;
}


void HTTPServer::GetPerformanceData(SW_PerformanceData * p)
{
    memcpy(p, &perfData, sizeof(perfData));
}


unsigned int HTTPServer::RecordPerformanceData(SW_PerformanceParam * param, unsigned int refTime)
{
    unsigned int t_now = (unsigned int)PerformanceTimer.read_us();
    param->TotalTime_us += (t_now - refTime);
    param->Samples++;
    if ((t_now - refTime) > param->MaxTime_us)
        param->MaxTime_us = (t_now - refTime);
    return t_now;
}


void HTTPServer::ResetPerformanceData()
{
    memset(&perfData, 0, sizeof(perfData));
}