A simple web server mainly based on ideas from Jasper Schuurmans Netduino web server

Dependents:   RdBlindsServer SpideyWallWeb RdGasUseMonitor

A fast and reliable web server for MBED! http://robdobson.com/2015/08/a-reliable-mbed-webserver/

It has a very neat way to implement REST commands and can serve files from local storage (on LPC1768 for instance) and from SD cards. It also has a caching facility which is particularly useful for serving files from local storage.

The server can be run in the main() thread (and has a sub-2ms response time if this is done) or in a mbed-rtos thread which increases the response time to (a still respectable) 30ms or so.

The latest project that uses this is here - https://developer.mbed.org/users/Bobty/code/SpideyWallWeb/

int main (void)
{
    // Ethernet interface
    EthernetInterface::init();

    // Connect ethernet
    EthernetInterface::connect();

    // Init the web server
    pc.printf("Starting web server\r\n");
    char* baseWebFolder = "/sd/";  // should be /sd/ for SDcard files - not used for local file system
    RdWebServer webServer;
    
    // Add commands to handle the home page and favicon
    webServer.addCommand("", RdWebServerCmdDef::CMD_LOCALFILE, NULL, "index.htm", true);
    webServer.addCommand("favicon.ico", RdWebServerCmdDef::CMD_LOCALFILE, NULL, NULL, true);
    
    // Add the lightwall control commands
    webServer.addCommand("name", RdWebServerCmdDef::CMD_CALLBACK, &lightwallGetSystemName);
    webServer.addCommand("clear", RdWebServerCmdDef::CMD_CALLBACK, &lightwallClear);
    webServer.addCommand("rawfill", RdWebServerCmdDef::CMD_CALLBACK, &lightwallRawFill);
    webServer.addCommand("fill", RdWebServerCmdDef::CMD_CALLBACK, &lightwallFill);
    webServer.addCommand("showleds", RdWebServerCmdDef::CMD_CALLBACK, &lightwallShowLeds);
    
    // Start the server
    webServer.init(WEBPORT, &led4, baseWebFolder);
    webServer.run();

}

// Get system name - No arguments required
char* lightwallGetSystemName(int method, char*cmdStr, char* argStr, char* msgBuffer, int msgLen, 
                int contentLen, unsigned char* pPayload, int payloadLen, int splitPayloadPos)
{
    // Perform any required actions here ....

    // ...

    // Return the system name
    return systemName;
}

This server was originally based on a Netduino web server from Jasper Schuurmans but has been optimised for speed.

Files at this revision

API Documentation at this revision

Comitter:
Bobty
Date:
Fri Oct 04 07:41:28 2013 +0000
Parent:
1:75bb184de749
Child:
3:594136d34a32
Commit message:
Initial Revision Working

Changed in this revision

RdWebServer.cpp Show annotated file Show diff for this revision Revisions of this file
RdWebServer.h Show annotated file Show diff for this revision Revisions of this file
--- a/RdWebServer.cpp	Thu Sep 19 12:06:18 2013 +0000
+++ b/RdWebServer.cpp	Fri Oct 04 07:41:28 2013 +0000
@@ -3,6 +3,44 @@
 #define MAX_CMDSTR_LEN 100
 #define MAX_ARGSTR_LEN 100
 
+bool RdFileCacheEntry::readLocalFileIntoCache(char* fileName)
+{
+    printf("Reading into cache %s\n\r", fileName);
+    LocalFileSystem local("local");
+    FILE* fp = fopen(fileName, "r");
+    if (fp == NULL)
+    {
+        printf("Failed to open file\n\r");
+        return false;
+    }
+    fseek(fp, 0, SEEK_END);
+    _nFileLen = (int)ftell(fp);
+    _pFileContent = new char[_nFileLen];
+    if (!_pFileContent)
+    {
+        printf("Failed to allocate %lu\n\r", _nFileLen);
+        fclose(fp);
+        return false;
+    }
+    fseek(fp, 0, SEEK_SET);
+    char* pMem = _pFileContent;
+    char fileBuf[500];
+    int totCnt = 0;
+    int rdCnt;
+    while ((rdCnt = fread(fileBuf, sizeof( char ), 500, fp)) == 500) 
+    {
+        memcpy(pMem, fileBuf, rdCnt);
+        pMem += rdCnt;
+        totCnt += rdCnt;
+    }
+    memcpy(pMem, fileBuf, rdCnt);
+    totCnt += rdCnt;
+    fclose(fp);
+    printf("Success in caching %d bytes (read %d)\n\r", _nFileLen, totCnt);
+    _bCacheValid = true;
+    return true;
+}
+
 RdWebServer::RdWebServer()
 {
     _serverIsListening = false;
@@ -11,6 +49,9 @@
 
 RdWebServer::~RdWebServer()
 {
+    // Clean-up - probably never called as we're on a microcontroller!
+    for (std::vector<RdWebServerCmdDef*>::iterator it = _commands.begin() ; it != _commands.end(); ++it)
+        delete (*it);
 }
 
 bool RdWebServer::init(int port, DigitalOut* pStatusLed)
@@ -24,23 +65,23 @@
     //setup tcp socket
     if(_socketSrv.bind(port)< 0) 
     {
-        printf("tcp server bind failed.\n\r");
+        printf("TCP server bind fail\n\r");
         return false;
     }
     else 
     {
-        printf("tcp server bind successed.\n\r");
+//        printf("TCP server bind success\n\r");
         _serverIsListening = true;
     }
 
     if(_socketSrv.listen(1) < 0)
     {
-        printf("tcp server listen failed.\n\r");
+        printf("TCP server listen fail\n\r");
         return false;
     }
     else 
     {
-        printf("tcp server is listening...\n\r");
+        printf("TCP server is listening...\r\n");
     }
     
     return true;
@@ -83,73 +124,257 @@
     }
     return true;
 }
-  
+
+void RdWebServer::sendFromCache(RdFileCacheEntry* pCacheEntry, TCPSocketConnection* pClient, char* httpHeader)
+{
+    printf ("Sending file %s from cache %d bytes\r\n", pCacheEntry->_fileName, pCacheEntry->_nFileLen);
+    sprintf(httpHeader,"HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: Close\r\n\r\n");
+    pClient->send(httpHeader,strlen(httpHeader));
+    char* pMem = pCacheEntry->_pFileContent;
+    int nLenLeft = pCacheEntry->_nFileLen;
+    int blkSize = 2048;
+    while(nLenLeft > 0)
+    {
+        if (blkSize > nLenLeft)
+            blkSize = nLenLeft;
+        pClient->send_all(pMem, blkSize);
+        pMem += blkSize;
+        nLenLeft -= blkSize;
+    }
+}
+
+void RdWebServer::handleLocalFileRequest(char* inFileName, char* argStr, TCPSocketConnection* pClient, char* httpHeader, bool bCacheIfPossible)
+{
+    const int HTTPD_MAX_FNAME_LENGTH = 127;
+    char localFilename[HTTPD_MAX_FNAME_LENGTH+1];
+    char reqFileNameStr[HTTPD_MAX_FNAME_LENGTH+1];
+
+    printf("Requesting local file %s\n\r", inFileName);
+    sprintf(reqFileNameStr, "/%s", inFileName);
+    sprintf(localFilename, "/local/%s", inFileName);
+        
+    if (bCacheIfPossible)
+    {
+        // Check if file already cached
+        bool bTryToCache = true;
+        for (std::vector<RdFileCacheEntry*>::iterator it = _cachedFiles.begin() ; it != _cachedFiles.end(); ++it)
+        {
+            if (strcmp(inFileName, (*it)->_fileName) == 0)
+            {
+                if ((*it)->_bCacheValid)
+                {
+                    sendFromCache(*it, pClient, httpHeader);
+                    return;
+                }
+                bTryToCache = false; // don't try to cache as cacheing must have already failed
+            }
+        }
+        
+        // See if we can cache the file
+        if (bTryToCache)
+        {
+            RdFileCacheEntry* pCacheEntry = new RdFileCacheEntry(inFileName);
+            if (pCacheEntry)
+            {
+                bool bCacheSuccess = pCacheEntry->readLocalFileIntoCache(localFilename);
+                // Store the cache entry even if reading failed (mem alloc or file not found, etc) so we don't try to cache again
+                _cachedFiles.push_back(pCacheEntry);
+                if (bCacheSuccess)
+                {
+                    sendFromCache(pCacheEntry, pClient, httpHeader);
+                    return;
+                }
+            }
+        }        
+    }
+    
+    LocalFileSystem local("local");
+    
+    FILE* fp = fopen(localFilename, "r");
+    if (fp == NULL)
+    {
+        printf ("Local file %s not found\r\n", localFilename);
+        sprintf(httpHeader,"HTTP/1.1 404 Not Found \r\nContent-Type: text\r\nConnection: Close\r\n\r\n");
+        pClient->send(httpHeader,strlen(httpHeader));
+        pClient->send(reqFileNameStr,strlen(reqFileNameStr));
+    }
+    else
+    {
+        printf ("Sending file %s from disk\r\n", localFilename);
+        sprintf(httpHeader,"HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: Close\r\n\r\n");
+        pClient->send(httpHeader,strlen(httpHeader));
+        int rdCnt = 0;
+        char fileBuf[2000];
+        while ((rdCnt = fread(fileBuf, sizeof( char ), 2000, fp)) == 2000) 
+        {
+            pClient->send_all(fileBuf, rdCnt);
+        }
+        pClient->send_all(fileBuf, rdCnt);
+        fclose(fp);
+    }
+}
+
+void RdWebServer::handleSDFileRequest(char* inFileName, char* argStr, TCPSocketConnection* pClient, char* httpHeader)
+{
+    const int HTTPD_MAX_FNAME_LENGTH = 127;
+    char filename[HTTPD_MAX_FNAME_LENGTH+1];
+    
+    printf("Requesting file %s\n\r", inFileName);
+    
+    char *lstchr = strrchr(inFileName, NULL) -1;
+    if ('/' == *lstchr)
+    {
+        // printf("Open directory /sd/%s\n", inFileName);
+        *lstchr = 0;
+        sprintf(filename, "/sd/%s", inFileName);
+        DIR *d = opendir(filename);
+        if (d != NULL) {
+            sprintf(httpHeader,"HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: Close\r\n\r\n");
+            pClient->send(httpHeader,strlen(httpHeader));
+            sprintf(httpHeader,"<html><head><title>Directory Listing</title></head><body><h1>%s</h1><ul>", inFileName);
+            pClient->send(httpHeader,strlen(httpHeader));
+            struct dirent *p;
+            while((p = readdir(d)) != NULL) {
+                // printf("%s\n", p->d_name);
+                sprintf(httpHeader,"<li>%s</li>", p->d_name);
+                pClient->send(httpHeader,strlen(httpHeader));
+            }
+        }
+        closedir(d);
+        // printf("Directory closed\n");
+        sprintf(httpHeader,"</ul></body></html>");
+        pClient->send(httpHeader,strlen(httpHeader));
+    }
+    else
+    {
+        sprintf(filename, "/sd/%s", inFileName);
+        // printf ("Filename %s\r\n", filename);
+        FILE* fp = fopen(filename, "r");
+        if (fp == NULL)
+        {
+            printf ("Filename %s not found\r\n", filename);
+            sprintf(httpHeader,"HTTP/1.1 404 Not Found \r\nContent-Type: text\r\nConnection: Close\r\n\r\n");
+            pClient->send(httpHeader,strlen(httpHeader));
+            pClient->send(inFileName,strlen(inFileName));
+        }
+        else
+        {
+            printf ("Sending file %s\r\n", filename);
+            sprintf(httpHeader,"HTTP/1.1 200 OK\r\nContent-Type: text/html\r\nConnection: Close\r\n\r\n");
+            pClient->send(httpHeader,strlen(httpHeader));
+            int rdCnt = 0;
+            char fileBuf[1024];
+            while ((rdCnt = fread(fileBuf, sizeof( char ), 1024, fp)) == 1024) 
+            {
+                pClient->send(fileBuf, rdCnt);
+            }
+            pClient->send(fileBuf, rdCnt);
+            fclose(fp);
+        }
+    }
+}
+
 void RdWebServer::run()
 {
     TCPSocketConnection client;
-    bool clientIsConnected = false;
-
+    const int HTTPD_MAX_HDR_LENGTH = 255;
+    char httpHeader[HTTPD_MAX_HDR_LENGTH+1];
+    const int HTTPD_MAX_REQ_LENGTH = 1023;
+    char buffer[HTTPD_MAX_REQ_LENGTH+1];
+    
     //listening for http GET request
-    while (isListening()) 
+    while (isListening())
     {
         //blocking mode(never timeout)
         if(_socketSrv.accept(client)<0) 
         {
-            printf("failed to accept connection.\n\r");
+            printf("TCP Socket failed to accept connection\n\r");
         }
         else
         {
-            printf("connection success!\n\rIP: %s\n\r",client.get_address());
-            clientIsConnected = true;
+            client.set_blocking(false, 1000);
+            printf("Connection from IP: %s\n\r",client.get_address());
             if (_pStatusLed != NULL)
                 *_pStatusLed = true;
+            Timer connectLimitTimer;
+            connectLimitTimer.start();
             
-            while(clientIsConnected) 
+            while(connectLimitTimer.read() < 5)  // 5 seconds timeout on HTTP operation
             {
-                char buffer[1024] = {};
-                switch(client.receive(buffer, 1023)) 
+                int rxLen = client.receive(buffer, 1023);
+                if (rxLen == -1)
+                {
+                    continue;
+                }
+                else if (rxLen == 0)
+                {
+                    printf("received buffer is empty.\n\r");
+                    break;                
+                }
+                else if (rxLen >= 1024)
                 {
-                    case 0:
-                        printf("recieved buffer is empty.\n\r");
-                        clientIsConnected = false;
-                        break;
-                    case -1:
-                        printf("failed to read data from client.\n\r");
-                        clientIsConnected = false;
-                        break;
-                    default:
-                        printf("Recieved Data: %d\n\r\n\r%.*s\n\r",strlen(buffer),strlen(buffer),buffer);
-                        if(buffer[0] == 'G' && buffer[1] == 'E' && buffer[2] == 'T' ) 
+                    sprintf(httpHeader,"HTTP/1.1 413 Request Entity Too Large \r\nContent-Type: text\r\nConnection: Close\r\n\r\n");
+                    client.send(httpHeader,strlen(httpHeader));
+                    client.send(buffer, rxLen);
+                    break;
+                }
+                buffer[rxLen] = '\0';
+//                printf("Received Data: %d\n\r\n\r%.*s\n\r",strlen(buffer),strlen(buffer),buffer);
+                if (strncmp(buffer, "GET ", 4) == 0)
+                {
+//                    printf("GET request incomming.\n\r");
+                    char cmdStr[MAX_CMDSTR_LEN];
+                    char argStr[MAX_ARGSTR_LEN];
+                    if (extractCmdArgs(buffer+3, cmdStr, MAX_CMDSTR_LEN, argStr, MAX_ARGSTR_LEN))
+                    {
+                        printf("CmdStr %s\n\r", cmdStr);
+                        printf("ArgStr %s\n\r", argStr);
+                        bool cmdFound = false;
+                        for (std::vector<RdWebServerCmdDef*>::iterator it = _commands.begin() ; it != _commands.end(); ++it)
                         {
-                            printf("GET request incomming.\n\r");
-                            char cmdStr[MAX_CMDSTR_LEN];
-                            char argStr[MAX_ARGSTR_LEN];
-                            if (extractCmdArgs(buffer+3, cmdStr, MAX_CMDSTR_LEN, argStr, MAX_ARGSTR_LEN))
-                            {
-                                printf("CmdStr %s\n\r", cmdStr);
-                                printf("ArgStr %s\n\r", argStr);
-                                for (std::vector<RdWebServerCmdDef*>::iterator it = _commands.begin() ; it != _commands.end(); ++it)
+//                            printf("Testing <<%s>> with <<%s>>\r\n", (*it)->_pCmdStr, cmdStr);
+                            if (strcasecmp((*it)->_pCmdStr, cmdStr) == 0)
+                            {                                    
+                                printf("FoundCmd <%s> Type %d\n\r", cmdStr, (*it)->_cmdType);
+                                cmdFound = true;
+                                if ((*it)->_cmdType == RdWebServerCmdDef::CMD_CALLBACK)
                                 {
-                                    if (strcasecmp((*it)->_pCmdStr, cmdStr) == 0)
-                                    {
-                                        printf("FoundCmd %s\n\r", cmdStr);
-                                        ((*it)->_callback)(argStr);
-                                    }
+                                    ((*it)->_callback)(cmdStr, argStr);
+                                }
+                                else if ((*it)->_cmdType == RdWebServerCmdDef::CMD_LOCALFILE)
+                                {
+                                    if ((*it)->_substFileName[0] != '\0')
+                                        handleLocalFileRequest((*it)->_substFileName, argStr, &client, httpHeader, (*it)->_bCacheIfPossible);
+                                    else
+                                        handleLocalFileRequest(cmdStr, argStr, &client, httpHeader, (*it)->_bCacheIfPossible);
                                 }
+                                else if ((*it)->_cmdType == RdWebServerCmdDef::CMD_SDCARDFILE)
+                                {
+                                    if ((*it)->_substFileName[0] != '\0')
+                                        handleSDFileRequest((*it)->_substFileName, argStr, &client, httpHeader);
+                                    else
+                                        handleSDFileRequest(cmdStr, argStr, &client, httpHeader);
+                                }
+                                break;
                             }
-                            
-                            //setup http response header & data
-                            char echoHeader[256] = {};
-                            sprintf(echoHeader,"HTTP/1.1 200 OK\n\rContent-Length: %d\n\rContent-Type: text\n\rConnection: Close\n\r\n\r",strlen(buffer));
-                            client.send(echoHeader,strlen(echoHeader));
-                            client.send(cmdStr,strlen(cmdStr));
-                            clientIsConnected = false;
-                            printf("done.\n\r");
                         }
-                        break;
+                        // If command not found see if it is a local file
+                        if (!cmdFound)
+                            handleLocalFileRequest(cmdStr, argStr, &client, httpHeader, false);
+                    }
+                    
+                    //setup http response header & data
+/*                    char httpHeader[256] = {};
+                    sprintf(httpHeader,"HTTP/1.1 200 OK\n\rContent-Length: %d\n\rContent-Type: text\n\rConnection: Close\n\r\n\r",strlen(buffer));
+                    client.send(httpHeader,strlen(httpHeader));
+                    client.send(cmdStr,strlen(cmdStr)); */
+                    //clientIsConnected = false;
+//                    printf("Server done.\n\r");
+                    break;
                 }
+                
             }
-            printf("close connection.\n\rtcp server is listening...\n\r");
+            printf("Connection closed ... TCP server is listening...\r\n");
             client.close();
             if (_pStatusLed != NULL)
                 *_pStatusLed = false;
@@ -157,8 +382,8 @@
     }
 }
 
-void RdWebServer::addCommand(char* pCmdStr, CmdCallbackType callback)
+void RdWebServer::addCommand(char* pCmdStr, int cmdType, CmdCallbackType callback, char* substFileName, bool cacheIfPossible)
 {
-    _commands.push_back(new RdWebServerCmdDef(pCmdStr, callback));
+    _commands.push_back(new RdWebServerCmdDef(pCmdStr, cmdType, callback, substFileName, cacheIfPossible));
 }
 
--- a/RdWebServer.h	Thu Sep 19 12:06:18 2013 +0000
+++ b/RdWebServer.h	Fri Oct 04 07:41:28 2013 +0000
@@ -6,18 +6,55 @@
 #include "mbed.h"
 #include "EthernetInterface.h"
 
-typedef void (*CmdCallbackType)(char* argStr);
+class RdFileCacheEntry
+{
+    public:
+        static const int CACHE_MAX_FNAME_LEN = 15;  // note local files on MBED are 8.3
+        RdFileCacheEntry(char* pFileName)
+        {
+            _bCacheValid = false;
+            strncpy(_fileName, pFileName, CACHE_MAX_FNAME_LEN-1);
+            _fileName[CACHE_MAX_FNAME_LEN-1] = '\0';
+            _pFileContent = NULL;
+        }
+        ~RdFileCacheEntry()
+        {
+            delete _pFileContent;
+        }
+        bool readLocalFileIntoCache(char* fileName);
+    public:
+        bool _bCacheValid;
+        char _fileName[CACHE_MAX_FNAME_LEN];
+        char* _pFileContent;
+        int _nFileLen;
+};
+
+typedef void (*CmdCallbackType)(char*cmdStr, char* argStr);
 
 class RdWebServerCmdDef
 {
     public:
-        RdWebServerCmdDef(char* pStr, CmdCallbackType callback)
+        static const int CMD_LOCALFILE = 1;
+        static const int CMD_CALLBACK = 2;
+        static const int CMD_SDCARDFILE = 3;
+        RdWebServerCmdDef(char* pStr, int cmdType, CmdCallbackType callback, char* substFileName, bool bCacheIfPossible)
         {
             _pCmdStr = pStr;
+            _cmdType = cmdType;
             _callback = callback;
+            _substFileName[0] = '\0';
+            if (substFileName != NULL)
+            {
+                strncpy(_substFileName, substFileName, RdFileCacheEntry::CACHE_MAX_FNAME_LEN);
+                _substFileName[RdFileCacheEntry::CACHE_MAX_FNAME_LEN-1] = '\0';
+            }
+            _bCacheIfPossible = bCacheIfPossible;
         };
         char* _pCmdStr;
+        int _cmdType;
         CmdCallbackType _callback;
+        char _substFileName[RdFileCacheEntry::CACHE_MAX_FNAME_LEN];
+        bool _bCacheIfPossible;
 };
 
 class RdWebServer
@@ -34,7 +71,7 @@
             return _serverIsListening;
         };
         
-        void addCommand(char* pCmdStr, CmdCallbackType callback);
+        void addCommand(char* pCmdStr, int cmdType, CmdCallbackType callback = NULL, char* substFileName = NULL, bool cacheIfPossible = false);
         
     private :
         int _port;
@@ -42,9 +79,14 @@
         TCPSocketServer _socketSrv;
         bool _serverIsListening;
         std::vector<RdWebServerCmdDef*> _commands;
+        std::vector<RdFileCacheEntry*> _cachedFiles;
         bool extractCmdArgs(char* buf, char* pCmdStr, int maxCmdStrLen, char* pArgStr, int maxArgStrLen);
 
-        
+        void handleLocalFileRequest(char* cmdStr, char* argStr, TCPSocketConnection* pClient, char* httpHeader, bool bCacheIfPossible);
+        void handleSDFileRequest(char* cmdStr, char* argStr, TCPSocketConnection* pClient, char* httpHeader);
+        void handleCGIRequest(char* pUriStr, char* pQueryStr);
+        void sendFromCache(RdFileCacheEntry* pCacheEntry, TCPSocketConnection* pClient, char* httpHeader);
+
 };
 
 #endif