protocol.c

/*
** Copyright (c) 2002  Hughes Technologies Pty Ltd.  All rights
** reserved.
**
** Terms under which this software may be used or copied are
** provided in the  specific license associated with this product.
**
** Hughes Technologies disclaims all warranties with regard to this
** software, including all implied warranties of merchantability and
** fitness, in no event shall Hughes Technologies be liable for any
** special, indirect or consequential damages or any damages whatsoever
** resulting from loss of use, data or profits, whether in an action of
** contract, negligence or other tortious action, arising out of or in
** connection with the use or performance of this software.
**
**
** $Id: protocol.c,v 1.6 2005/02/12 15:38:22 minaguib Exp $
**
*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <time.h>

#if defined(_WIN32) 
#else
#include <unistd.h>
#include <sys/file.h>
#endif

#include "config.h"
#include "httpd.h"
#include "httpd_priv.h"

int _httpd_net_read(sock, buf, len)
        int     sock;
        char    *buf;
        int     len;
{
#if defined(_WIN32) 
        return( recv(sock, buf, len, 0));
#else
        /*return( read(sock, buf, len));*/
        /* XXX Select based IO */

        int             nfds;
        fd_set          readfds;
        struct timeval  timeout;
        
        FD_ZERO(&readfds);
        FD_SET(sock, &readfds);
        timeout.tv_sec = 10;
        timeout.tv_usec = 0;
        nfds = sock + 1;

        nfds = select(nfds, &readfds, NULL, NULL, &timeout);

        if (nfds > 0) {
                return(read(sock, buf, len));
        }
        return(nfds);
#endif
}


int _httpd_net_write(sock, buf, len)
        int     sock;
        char    *buf;
        int     len;
{
#if defined(_WIN32) 
        return( send(sock, buf, len, 0));
#else
        return( write(sock, buf, len));
#endif
}

int _httpd_readChar(request *r, char *cp)
{
        if (r->readBufRemain == 0)
        {
                bzero(r->readBuf, HTTP_READ_BUF_LEN + 1);
                r->readBufRemain = _httpd_net_read(r->clientSock, 
                        r->readBuf, HTTP_READ_BUF_LEN);
                if (r->readBufRemain < 1)
                        return(0);
                r->readBuf[r->readBufRemain] = 0;
                r->readBufPtr = r->readBuf;
        }
        *cp = *r->readBufPtr++;
        r->readBufRemain--;
        return(1);
}


int _httpd_readLine(request *r, char *destBuf, int len)
{
        char    curChar,
                *dst;
        int     count;
        

        count = 0;
        dst = destBuf;
        while(count < len)
        {
                if (_httpd_readChar(r, &curChar) < 1)
                        return(0);
                // Fixed by Mina - if we read binary junk it's probably not a regular HTTP client
                //if (curChar == '\n')
                if (curChar == '\n' || !isascii(curChar))
                {
                        *dst = 0;
                        return(1);
                }
                if (curChar == '\r')
                {
                        continue;
                }
                else
                {
                        *dst++ = curChar;
                        count++;
                }
        }
        *dst = 0;
        return(1);
}


int _httpd_readBuf(request *r, char *destBuf, int len)
{
        char    curChar,
                *dst;
        int     count;
        

        count = 0;
        dst = destBuf;
        while(count < len)
        {
                if (_httpd_readChar(r, &curChar) < 1)
                        return(0);
                *dst++ = curChar;
                count++;
        }
        return(1);
}

void _httpd_writeAccessLog(httpd *server, request *r)
{
        char    dateBuf[30];
        struct  tm *timePtr;
        time_t  clock;
        int     responseCode;


        if (server->accessLog == NULL)
                return;
        clock = time(NULL);
        timePtr = localtime(&clock);
        strftime(dateBuf, 30, "%d/%b/%Y:%T %Z",  timePtr);
        responseCode = atoi(r->response.response);
        fprintf(server->accessLog, "%s - - [%s] %s \"%s\" %d %d\n", 
                r->clientAddr, dateBuf, httpdRequestMethodName(r), 
                httpdRequestPath(r), responseCode, 
                r->response.responseLength);
}

void _httpd_writeErrorLog(httpd *server, request *r, char *level, char *message)
{
        char    dateBuf[30];
        struct  tm *timePtr;
        time_t  clock;


        if (server->errorLog == NULL)
                return;
        clock = time(NULL);
        timePtr = localtime(&clock);
        strftime(dateBuf, 30, "%a %b %d %T %Y",  timePtr);
        if (r != NULL && *r->clientAddr != 0)
        {
                fprintf(server->errorLog, "[%s] [%s] [client %s] %s\n",
                        dateBuf, level, r->clientAddr, message);
        }
        else
        {
                fprintf(server->errorLog, "[%s] [%s] %s\n",
                        dateBuf, level, message);
        }
}



int _httpd_decode (bufcoded, bufplain, outbufsize)
        char *          bufcoded;
        char *          bufplain;
        int             outbufsize;
{
        static char six2pr[64] = {
                'A','B','C','D','E','F','G','H','I','J','K','L','M',
                'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
                'a','b','c','d','e','f','g','h','i','j','k','l','m',
                'n','o','p','q','r','s','t','u','v','w','x','y','z',
                '0','1','2','3','4','5','6','7','8','9','+','/'   
        };
  
        static unsigned char pr2six[256];

        /* single character decode */
#       define DEC(c) pr2six[(int)c]
#       define _DECODE_MAXVAL 63

        static int first = 1;

        int nbytesdecoded, j;
        register char *bufin = bufcoded;
        register unsigned char *bufout = bufplain;
        register int nprbytes;

        /*
        ** If this is the first call, initialize the mapping table.
        ** This code should work even on non-ASCII machines.
        */
        if(first) 
        {
                first = 0;
                for(j=0; j<256; j++) pr2six[j] = _DECODE_MAXVAL+1;
                for(j=0; j<64; j++) pr2six[(int)six2pr[j]] = (unsigned char)j;
        }

        /* Strip leading whitespace. */

        while(*bufcoded==' ' || *bufcoded == '\t') bufcoded++;

        /*
        ** Figure out how many characters are in the input buffer.
        ** If this would decode into more bytes than would fit into
        ** the output buffer, adjust the number of input bytes downwards.
        */
        bufin = bufcoded;
        while(pr2six[(int)*(bufin++)] <= _DECODE_MAXVAL);
        nprbytes = bufin - bufcoded - 1;
        nbytesdecoded = ((nprbytes+3)/4) * 3;
        if(nbytesdecoded > outbufsize) 
        {
                nprbytes = (outbufsize*4)/3;
        }
        bufin = bufcoded;
   
        while (nprbytes > 0) 
        {
                *(bufout++)=(unsigned char)(DEC(*bufin)<<2|DEC(bufin[1])>>4);
                *(bufout++)=(unsigned char)(DEC(bufin[1])<<4|DEC(bufin[2])>>2);
                *(bufout++)=(unsigned char)(DEC(bufin[2])<<6|DEC(bufin[3]));
                bufin += 4;
                nprbytes -= 4;
        }
        if(nprbytes & 03) 
        {
                if(pr2six[(int)bufin[-2]] > _DECODE_MAXVAL) 
                {
                        nbytesdecoded -= 2;
                }
                else 
                {
                        nbytesdecoded -= 1;
                }
        }
        bufplain[nbytesdecoded] = 0;
        return(nbytesdecoded);
}



char _httpd_from_hex (c)
        char    c;
{
    return  c >= '0' && c <= '9' ?  c - '0'
            : c >= 'A' && c <= 'F'? c - 'A' + 10
            : c - 'a' + 10;     /* accept small letters just in case */
}

char * _httpd_unescape(str)
        char    *str;
{
    char * p = str;
    char * q = str;
    static char blank[] = "";

    if (!str)
        return(blank);
    while(*p) {
        if (*p == '%') {
            p++;
            if (*p) *q = _httpd_from_hex(*p++) * 16;
            if (*p) *q = (*q + _httpd_from_hex(*p++));
            q++;
        } else {
            if (*p == '+') {
                *q++ = ' ';
                p++;
            } else {
                *q++ = *p++;
              }
        }
    }

    *q++ = 0;
    return str;
} 


void _httpd_freeVariables(var)
        httpVar *var;
{
        httpVar *curVar, *lastVar;

        if (var == NULL)
                return;
        _httpd_freeVariables(var->nextVariable);
        var->nextVariable = NULL;
        curVar = var;
        while(curVar)
        {
                lastVar = curVar;
                curVar = curVar->nextValue;
                free(lastVar->name);
                free(lastVar->value);
                free(lastVar);
        }
        return;
}

void _httpd_storeData(request *r, char *query)
{
        char    *cp,
                *cp2,
                *var,
                *val,
                *tmpVal;

        if (!query)
                return;

        var = (char *)malloc(strlen(query));
        
        cp = query;
        cp2 = var;
        bzero(var, strlen(query));
        val = NULL;
        while(*cp)
        {
                if (*cp == '=')
                {
                        cp++;
                        *cp2 = 0;
                        val = cp;
                        continue;
                }
                if (*cp == '&')
                {
                        *cp = 0;
                        tmpVal = _httpd_unescape(val);
                        httpdAddVariable(r, var, tmpVal);
                        cp++;
                        cp2 = var;
                        val = NULL;
                        continue;
                }
                if (val)
                {
                        cp++;
                }
                else
                {
                        *cp2 = *cp++;
                        if (*cp2 == '.')
                        {
                                strcpy(cp2,"_dot_");
                                cp2 += 5;
                        }
                        else
                        {
                                cp2++;
                        }
                }
        }
        *cp = 0;
        tmpVal = _httpd_unescape(val);
        httpdAddVariable(r, var, tmpVal);
        free(var);
}


void _httpd_formatTimeString(char *ptr, int clock)
{
        struct  tm *timePtr;

        if (clock == 0)
                clock = time(NULL);
        timePtr = gmtime((time_t*)&clock);
        strftime(ptr, HTTP_TIME_STRING_LEN,"%a, %d %b %Y %T GMT",timePtr);
}


void _httpd_sendHeaders(request *r, int contentLength, int modTime)
{
        char    tmpBuf[80],
                timeBuf[HTTP_TIME_STRING_LEN];

        if(r->response.headersSent)
                return;

        r->response.headersSent = 1;
        _httpd_net_write(r->clientSock, "HTTP/1.0 ", 9);
        _httpd_net_write(r->clientSock, r->response.response, 
                strlen(r->response.response));
        _httpd_net_write(r->clientSock, r->response.headers, 
                strlen(r->response.headers));

        _httpd_formatTimeString(timeBuf, 0);
        _httpd_net_write(r->clientSock,"Date: ", 6);
        _httpd_net_write(r->clientSock, timeBuf, strlen(timeBuf));
        _httpd_net_write(r->clientSock, "\n", 1);

        _httpd_net_write(r->clientSock, "Connection: close\n", 18);
        _httpd_net_write(r->clientSock, "Content-Type: ", 14);
        _httpd_net_write(r->clientSock, r->response.contentType, 
                strlen(r->response.contentType));
        _httpd_net_write(r->clientSock, "\n", 1);

        if (contentLength > 0)
        {
                _httpd_net_write(r->clientSock, "Content-Length: ", 16);
                snprintf(tmpBuf, sizeof(tmpBuf), "%d", contentLength);
                _httpd_net_write(r->clientSock, tmpBuf, strlen(tmpBuf));
                _httpd_net_write(r->clientSock, "\n", 1);

                _httpd_formatTimeString(timeBuf, modTime);
                _httpd_net_write(r->clientSock, "Last-Modified: ", 15);
                _httpd_net_write(r->clientSock, timeBuf, strlen(timeBuf));
                _httpd_net_write(r->clientSock, "\n", 1);
        }
        _httpd_net_write(r->clientSock, "\n", 1);
}

httpDir *_httpd_findContentDir(server, dir, createFlag)
        httpd   *server;
        char    *dir;
        int     createFlag;
{
        char    buffer[HTTP_MAX_URL],
                *curDir;
        httpDir *curItem,
                *curChild;

        strncpy(buffer, dir, HTTP_MAX_URL);
        curItem = server->content;
        curDir = strtok(buffer,"/");
        while(curDir)
        {
                curChild = curItem->children;
                while(curChild)
                {
                        if (strcmp(curChild->name, curDir) == 0)
                                break;
                        curChild = curChild->next;
                }
                if (curChild == NULL)
                {
                        if (createFlag == HTTP_TRUE)
                        {
                                curChild = malloc(sizeof(httpDir));
                                bzero(curChild, sizeof(httpDir));
                                curChild->name = strdup(curDir);
                                curChild->next = curItem->children;
                                curItem->children = curChild;
                        }
                        else
                        {
                                return(NULL);
                        }
                }
                curItem = curChild;
                curDir = strtok(NULL,"/");
        }
        return(curItem);
}


httpContent *_httpd_findContentEntry(request *r, httpDir *dir, char *entryName)
{
        httpContent *curEntry;

        curEntry = dir->entries;
        while(curEntry)
        {
                if (curEntry->type == HTTP_WILDCARD || 
                    curEntry->type ==HTTP_C_WILDCARD)
                        break;
                if (*entryName == 0 && curEntry->indexFlag)
                        break;
                if (strcmp(curEntry->name, entryName) == 0)
                        break;
                curEntry = curEntry->next;
        }
        if (curEntry)
                r->response.content = curEntry;
        return(curEntry);
}


void _httpd_send304(request *r)
{
        httpdSetResponse(r, "304 Not Modified\n");
        _httpd_sendHeaders(r,0,0);
}


void _httpd_send403(request *r)
{
        httpdSetResponse(r, "403 Permission Denied\n");
        _httpd_sendHeaders(r,0,0);
        _httpd_sendText(r,
                "<HTML><HEAD><TITLE>403 Permission Denied</TITLE></HEAD>\n");
        _httpd_sendText(r,
                "<BODY><H1>Access to the request URL was denied!</H1>\n");
}


void _httpd_send404(httpd *server, request *r)
{
        char    msg[HTTP_MAX_URL];

        snprintf(msg, HTTP_MAX_URL,
                "File does not exist: %s\n", r->request.path);
        _httpd_writeErrorLog(server, r, LEVEL_ERROR, msg);

        if (server->handle404 && server->handle404->function) {
                /*
                 * There's a custom C 404 handler defined with httpdAddC404Content
                 */
                (server->handle404->function)(server, r);
        }
        else {
                /*
                 * Send stock 404
                 */
                httpdSetResponse(r, "404 Not Found\n");
                _httpd_sendHeaders(r,0,0);
                _httpd_sendText(r,
                        "<HTML><HEAD><TITLE>404 Not Found</TITLE></HEAD>\n");
                _httpd_sendText(r,
                        "<BODY><H1>The request URL was not found!</H1>\n");
                _httpd_sendText(r, "</BODY></HTML>\n");
        }
}


void _httpd_catFile(request *r, char *path)
{
        int     fd,
                len;
        char    buf[HTTP_MAX_LEN];

        fd = open(path,O_RDONLY);
        if (fd < 0)
                return;
        len = read(fd, buf, HTTP_MAX_LEN);
        while(len > 0)
        {
                r->response.responseLength += len;
                _httpd_net_write(r->clientSock, buf, len);
                len = read(fd, buf, HTTP_MAX_LEN);
        }
        close(fd);
}


void _httpd_sendStatic(httpd *server, request *r, char *data)
{
        if (_httpd_checkLastModified(r, server->startTime) == 0)
        {
                _httpd_send304(r);
        }
        _httpd_sendHeaders(r, server->startTime, strlen(data));
        httpdOutput(r, data);
}



void _httpd_sendFile(httpd *server, request *r, char *path)
{
        char    *suffix;
        struct  stat sbuf;

        suffix = rindex(path, '.');
        if (suffix != NULL)
        {
                if (strcasecmp(suffix,".gif") == 0) 
                        strcpy(r->response.contentType,"image/gif");
                if (strcasecmp(suffix,".jpg") == 0) 
                        strcpy(r->response.contentType,"image/jpeg");
                if (strcasecmp(suffix,".xbm") == 0) 
                        strcpy(r->response.contentType,"image/xbm");
                if (strcasecmp(suffix,".png") == 0) 
                        strcpy(r->response.contentType,"image/png");
        }
        if (stat(path, &sbuf) < 0)
        {
                _httpd_send404(server, r);
                return;
        }
        if (_httpd_checkLastModified(r, sbuf.st_mtime) == 0)
        {
                _httpd_send304(r);
        }
        else
        {
                _httpd_sendHeaders(r, sbuf.st_size, sbuf.st_mtime);
                _httpd_catFile(r, path);
        }
}


int _httpd_sendDirectoryEntry(httpd *server, request *r, httpContent *entry,
                char *entryName)
{
        char            path[HTTP_MAX_URL];

        snprintf(path, HTTP_MAX_URL, "%s/%s", entry->path, entryName);
        _httpd_sendFile(server, r, path);
        return(0);
}


void _httpd_sendText(request *r, char *msg)
{
        r->response.responseLength += strlen(msg);
        _httpd_net_write(r->clientSock,msg,strlen(msg));
}


int _httpd_checkLastModified(request *r, int modTime)
{
        char    timeBuf[HTTP_TIME_STRING_LEN];

        _httpd_formatTimeString(timeBuf, modTime);
        if (strcmp(timeBuf, r->request.ifModified) == 0)
                return(0);
        return(1);
}


static unsigned char isAcceptable[96] =

/* Overencodes */
#define URL_XALPHAS     (unsigned char) 1
#define URL_XPALPHAS    (unsigned char) 2

/*      Bit 0           xalpha          -- see HTFile.h
**      Bit 1           xpalpha         -- as xalpha but with plus.
**      Bit 2 ...       path            -- as xpalpha but with /
*/
    /*   0 1 2 3 4 5 6 7 8 9 A B C D E F */
    {    7,0,0,0,0,0,0,0,0,0,7,0,0,7,7,7,       /* 2x   !"#$%&'()*+,-./ */
         7,7,7,7,7,7,7,7,7,7,0,0,0,0,0,0,       /* 3x  0123456789:;<=>?  */
         7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,       /* 4x  @ABCDEFGHIJKLMNO */
         7,7,7,7,7,7,7,7,7,7,7,0,0,0,0,7,       /* 5X  PQRSTUVWXYZ[\]^_ */
         0,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,       /* 6x  `abcdefghijklmno */
         7,7,7,7,7,7,7,7,7,7,7,0,0,0,0,0 };     /* 7X  pqrstuvwxyz{\}~ DEL */
 
#define ACCEPTABLE(a)   ( a>=32 && a<128 && ((isAcceptable[a-32]) & mask))

static char *hex = "0123456789ABCDEF";


char *_httpd_escape(str)
        char *str;
{
    unsigned char mask = URL_XPALPHAS;
    char * p;
    char * q;
    char * result;
    int unacceptable = 0;
    for(p=str; *p; p++)
        if (!ACCEPTABLE((unsigned char)*p))
                unacceptable +=2;
    result = (char *) malloc(p-str + unacceptable + 1);
    bzero(result,(p-str + unacceptable + 1));

    if (result == NULL)
    {
        return(NULL);
    }
    for(q=result, p=str; *p; p++) {
        unsigned char a = *p;
        if (!ACCEPTABLE(a)) {
            *q++ = '%';  /* Means hex commming */
            *q++ = hex[a >> 4];
            *q++ = hex[a & 15];
        }
        else *q++ = *p;
    }
    *q++ = 0;                   /* Terminate */
    return result;
}



void _httpd_sanitiseUrl(url)
        char    *url;
{
        char    *from,
                *to,
                *last;

        /*
        ** Remove multiple slashes
        */
        from = to = url;
        while(*from)
        {
                if (*from == '/' && *(from+1) == '/')
                {
                        from++;
                        continue;
                }
                *to = *from;
                to++;
                from++;
        }
        *to = 0;


        /*
        ** Get rid of ./ sequences
        */
        from = to = url;
        while(*from)
        {
                if (*from == '/' && *(from+1) == '.' && *(from+2)=='/')
                {
                        from += 2;
                        continue;
                }
                *to = *from;
                to++;
                from++;
        }
        *to = 0;


        /*
        ** Catch use of /../ sequences and remove them.  Must track the
        ** path structure and remove the previous path element.
        */
        from = to = last = url;
        while(*from)
        {
                if (*from == '/' && *(from+1) == '.' && 
                        *(from+2)=='.' && *(from+3)=='/')
                {
                        to = last;
                        from += 3;
                        continue;
                }
                if (*from == '/')
                {
                        last = to;
                }
                *to = *from;
                to++;
                from++;
        }
        *to = 0;
}

---