#ident "$Id: cgi.c,v 1.6 2011/04/16 07:02:28 pwh Exp $"
/*
* Sudoku Puzzle Solver, CGI interface logic.
*/
#if defined(DEBUG)
#include <stdio.h>
extern FILE *logFile;
#endif
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include "cgi.h"
static const char *environ [] = {
"AUTH_TYPE",
"CONTENT_LENGTH",
"CONTENT_TYPE",
"GATEWAY_INTERFACE",
"HTTP_ACCEPT",
"HTTP_ACCEPT_LANGUAGE",
"HTTP_COOKIE",
"HTTP_USER_AGENT",
"PATH_INFO",
"PATH_TRANSLATED",
"QUERY_STRING",
"REMOTE_ADDR",
"REMOTE_HOST",
"REMOTE_IDENT",
"REMOTE_USER",
"REQUEST_METHOD",
"SCRIPT_NAME",
"SERVER_NAME",
"SERVER_PROTOCOL",
"SERVER_PORT",
"SERVER_SOFTWARE"
};
#define AUTH_TYPE 0
#define CONTENT_LENGTH 1
#define CONTENT_TYPE 2
#define GATEWAY_INTERFACE 3
#define HTTP_ACCEPT 4
#define HTTP_ACCEPT_LANGUAGE 5
#define HTTP_COOKIE 6
#define HTTP_USER_AGENT 7
#define PATH_INFO 8
#define PATH_TRANSLATED 9
#define QUERY_STRING 10
#define REMOTE_ADDR 11
#define REMOTE_HOST 12
#define REMOTE_IDENT 13
#define REMOTE_USER 14
#define REQUEST_METHOD 15
#define SCRIPT_NAME 16
#define SERVER_NAME 17
#define SERVER_PROTOCOL 18
#define SERVER_PORT 19
#define SERVER_SOFTWARE 20
#define ENVIRON_COUNT 21
static int envcmp ( const unsigned char *p, const unsigned char *q,
const unsigned char **environValue )
{
int diff;
#if defined(DEBUG)
fprintf ( logFile, "envcmp ( \"%s\", \"%s\" ) {\n", p, q );
fflush ( logFile );
#endif
*environValue = NULL;
while ( ! ( diff = *p - *q ) && *p != '=' && *q ) {
++p;
++q;
}
if ( diff && *p == '=' && ! *q ) {
diff = 0;
*environValue = ++p;
}
#if defined(DEBUG)
fprintf ( logFile, "} = %d /* envcmp () */\n", diff );
fflush ( logFile );
#endif
return ( diff );
}
static int findEnv ( const char *name, const char **environValues )
{
int top = ENVIRON_COUNT;
int bottom = 0;
int i = ( top + bottom ) >> 1;
int found = -1;
const unsigned char *environValue = NULL;
#if defined(DEBUG)
fprintf ( logFile, "findEnv ( \"%s\" ) {\n", name );
fflush ( logFile );
#endif
while ( top > bottom ) {
int diff = envcmp ( name, environ [i], &environValue );
if ( diff > 0 ) {
bottom = i + 1;
} else if ( diff < 0 ) {
top = i;
} else {
found = i;
break;
}
i = ( top + bottom ) >> 1;
}
if ( found > -1 && *environValue ) environValues [found] = environValue;
#if defined(DEBUG)
fprintf ( logFile, "} = %s /* findEnv () */\n", found < 0 ? "not found"
: environ [found] );
fflush ( logFile );
#endif
return ( found );
}
static int readEnv ( char **envp, const char **environValues )
{
int i;
int status = 0;
#if defined(DEBUG)
fprintf ( logFile, "readEnv ( %p ) {\n", envp );
fflush ( logFile );
#endif
/* Initialize the environValues array. */
for ( i = 0; i < ENVIRON_COUNT; ++i ) environValues [i] = NULL;
while ( *envp ) {
if ( findEnv ( *envp, environValues ) > -1 ) ++status;
++envp;
}
if ( environValues [GATEWAY_INTERFACE] == NULL ) status = 0;
else {
const char *p = environValues [GATEWAY_INTERFACE];
while ( isspace ( *p ) ) ++p;
if ( toupper ( p[0] ) != 'C' || toupper ( p[1] ) != 'G'
|| toupper ( p[2] ) != 'I' ) status = 0;
}
#if defined(DEBUG)
fprintf ( logFile, "} = %d /* readEnv () */\n", status );
fflush ( logFile );
#endif
return ( status );
}
static char *decodeParams ( char *code )
{
int strLen = 0;
unsigned char *p = code;
unsigned char *decodedString = NULL;
#if defined(DEBUG)
fprintf ( logFile, "decodeParams ( \"%s\" ) {\n", code );
fflush ( logFile );
#endif
while ( *p ) {
if ( ! ( isspace ( *p ) ) ) {
++strLen;
if ( *p == '%' ) {
if ( isxdigit ( p [1] ) ) {
++p;
if ( isxdigit ( p [1] ) ) ++p;
}
}
}
++p;
}
if ( strLen > 0 && ( decodedString = malloc ( strLen + 1 ) ) ) {
char *q = decodedString;
p = code;
while ( *p ) {
if ( ! isspace ( *p ) ) {
if ( *p == '%' ) {
int ch;
int digit;
if ( isxdigit ( p [1] ) ) {
++p;
if ( isdigit ( *p ) ) digit = *p - '0';
else digit = toupper ( *p ) - 'A' + 10;
ch = digit;
if ( isxdigit ( p [1] ) ) {
++p;
if ( isdigit ( *p ) ) digit
= *p - '0';
else digit = toupper ( *p )
- 'A' + 10;
ch <<= 4;
ch += digit;
}
*q++ = ch;
} else *q++ = *p;
} else if ( *p == '+' ) {
*q++ = ' ';
} else *q++ = *p;
}
++p;
}
*q = '\0';
}
#if defined(DEBUG)
fprintf ( logFile, "} = \"%s\" /* decodeParams () */\n", decodedString );
fflush ( logFile );
#endif
return ( decodedString );
}
static void insertHeap ( CGIparams *params, int i )
{
int newName = params->sorted [i];
#if defined(DEBUG)
fprintf ( logFile, "insertHeap ( %p, %d ) {\n", params, i );
fflush ( logFile );
#endif
while ( i != 0 ) {
int parent = ( ( i + 1 ) >> 1 ) - 1;
if ( strcmp ( params->names [newName],
params->names [params->sorted [parent]] ) > 0 ) {
params->sorted [i] = params->sorted [parent];
i = parent;
} else break;
}
params->sorted [i] = newName;
#if defined(DEBUG)
fprintf ( logFile, "} /* insertHeap () */\n" );
fflush ( logFile );
#endif
}
static void emptyHeap ( CGIparams *params, int last )
{
int root = params->sorted [0];
int parent = 0;
int leftChild = 1;
int rightChild = 2;
#if defined(DEBUG)
fprintf ( logFile, "emptyHeap ( %p, %d ) {\n", params, last );
fflush ( logFile );
#endif
while ( leftChild <= last ) {
if ( rightChild > last
|| strcmp ( params->names [params->sorted [leftChild]],
params->names [params->sorted [rightChild]] ) > 0 ) {
params->sorted [parent] = params->sorted [leftChild];
parent = leftChild;
} else {
params->sorted [parent] = params->sorted [rightChild];
parent = rightChild;
}
rightChild = ( ( parent + 1 ) << 1 ) - 1;
leftChild = rightChild - 1;
}
if ( parent != last ) {
params->sorted [parent] = params->sorted [last];
insertHeap ( params, parent );
}
params->sorted [last] = root;
#if defined(DEBUG)
fprintf ( logFile, "} /* emptyHeap () */\n" );
fflush ( logFile );
#endif
}
static void sortParams ( CGIparams *params )
{
int i;
#if defined(DEBUG)
fprintf ( logFile, "sortParams ( %p ) {\n", params );
fflush ( logFile );
#endif
params->sorted [0] = 0;
for ( i = 1; i < params->paramCount; ++i ) {
params->sorted [i] = i;
insertHeap ( params, i );
}
for ( i = params->paramCount - 1; i > 0; --i ) emptyHeap ( params, i );
#if defined(DEBUG)
fprintf ( logFile, "} /* sortParams () */\n" );
fflush ( logFile );
#endif
}
static CGIparams *createCGIparams ( char *rawParams )
{
CGIparams *params = NULL;
int paramCount = 0;
char *p = rawParams;
#if defined(DEBUG)
fprintf ( logFile, "createCGIparams ( (%p) \"%s\" ) {\n", rawParams,
rawParams ? rawParams : "" );
fflush ( logFile );
#endif
if ( p ) {
/* Count the parameters */
while ( *p ) {
int length = 0;
char *q = p;
while ( *p != '&' && *p ) {
++length;
++p;
}
if ( length > 0 ) {
length = 0;
while ( *q != '=' && *q != '&' && *q ) {
length++;
++q;
}
if ( length > 0 && *q == '=' && *++q && *q != '&' )
paramCount++;
}
if ( *p == '&' ) ++p;
}
}
if ( ( params = ( CGIparams * ) malloc ( sizeof ( CGIparams )
+ 2 * ( paramCount + 1 ) * sizeof ( char * )
+ paramCount * sizeof ( int ) ) ) ) {
params->paramCount = paramCount;
params->names = ( char ** ) ( ( ( void * ) params )
+ sizeof ( CGIparams ) );
params->values = params->names + ( paramCount + 1 );
if ( paramCount ) params->sorted = ( int * )
( params->values + ( paramCount + 1 ) );
else params->sorted = NULL;
params->names [paramCount] = NULL;
params->values [paramCount] = NULL;
params->rawParams = rawParams;
if ( paramCount ) {
p = rawParams;
paramCount = 0;
while ( *p ) {
int length = 0;
char *name = p;
char *q = p;
char nameEnd;
char valueEnd;
while ( *p != '&' && *p ) {
++length;
++p;
}
if ( length > 0 ) {
valueEnd = *p;
*p = '\0';
length = 0;
while ( *q != '=' && *q != '&' && *q ) {
length++;
++q;
}
if ( length > 0 ) {
char *value = ( q + 1 );
nameEnd = *q;
*q = '\0';
if ( nameEnd == '=' && *value ) {
params->names [paramCount]
= strdup ( name );
params->values [paramCount]
= decodeParams ( value );
++paramCount;
}
*q = nameEnd;
}
*p = valueEnd;
}
if ( *p == '&' ) ++p;
}
sortParams ( params );
}
}
#if defined(DEBUG)
fprintf ( logFile, "} = %p /* createCGIparams () */\n", params );
fflush ( logFile );
#endif
return ( params );
}
static char *readStdin ( int length )
{
char *buffer = NULL;
char *p;
size_t buff_size = 255;
size_t buff_used = 0;
#if defined(DEBUG)
fprintf ( logFile, "readStdin ( %d ) {\n", length );
fflush ( logFile );
#endif
if ( length ) buff_size = length;
while ( p = realloc ( buffer, buff_size + 1 ) ) {
size_t bytesRead = 0;
buffer = p;
p += buff_used;
while ( buff_used < buff_size ) {
if ( ( bytesRead = read ( 0, p, buff_size - buff_used ) )
> 0 ) {
buff_used += bytesRead;
p += bytesRead;
} else {
if ( bytesRead < 0 ) p = NULL;
break;
}
}
if ( bytesRead > 0 && length == 0 ) {
buff_size += ( buff_size + 1 );
} else break;
}
if ( ! p || ( length > 0 && buff_used != length ) ) {
if ( buffer ) {
free ( buffer );
buffer = NULL;
}
} else if ( buffer ) buffer [buff_used] = '\0';
#if defined(DEBUG)
fprintf ( logFile, "} = %p /* readStdin () */\n", buffer );
fflush ( logFile );
#endif
return ( buffer );
}
void closeCGIparams ( CGIparams *deadMeat )
{
int i;
#if defined(DEBUG)
fprintf ( logFile, "closeCGIparams ( %p ) {\n", deadMeat );
fflush ( logFile );
#endif
if ( deadMeat ) {
for ( i = 0; i < deadMeat->paramCount; ++i ) {
free ( deadMeat->names [i] );
free ( deadMeat->values [i] );
}
if ( deadMeat->rawParams ) free ( deadMeat->rawParams );
free ( deadMeat );
}
#if defined(DEBUG)
fprintf ( logFile, "} /* closeCGIparams () */\n" );
fflush ( logFile );
#endif
}
CGIparams *openCGIparams ( char **envp )
{
CGIparams *params = NULL;
char *rawParams = NULL;
const char *environValues [ENVIRON_COUNT];
const char *p;
#if defined(DEBUG)
fprintf ( logFile, "openCGIparams ( %p ) {\n", envp );
fflush ( logFile );
#endif
if ( readEnv ( envp, environValues ) ) {
p = environValues [QUERY_STRING];
/* Get the query string, if there is one. */
if ( ! p ) {
const char *contentLength = environValues [CONTENT_LENGTH];
if ( contentLength ) {
int length = strtol ( contentLength, NULL, 0 );
rawParams = readStdin ( length );
}
} else rawParams = strdup ( p );
if ( params = createCGIparams ( rawParams ) ) {
params->servSoftware = environValues [SERVER_SOFTWARE];
params->servName = environValues [SERVER_NAME];
params->cgiRev = environValues [GATEWAY_INTERFACE];
params->servProtocol = environValues [SERVER_PROTOCOL];
params->servPort = environValues [SERVER_PORT];
params->reqMethod = environValues [REQUEST_METHOD];
params->pathInfo = environValues [PATH_INFO];
params->pathXlate = environValues [PATH_TRANSLATED];
params->scriptName = environValues [SCRIPT_NAME];
params->remoteHost = environValues [REMOTE_HOST];
params->remoteAddr = environValues [REMOTE_ADDR];
params->authType = environValues [AUTH_TYPE];
params->remoteUser = environValues [REMOTE_USER];
params->remoteID = environValues [REMOTE_IDENT];
params->contentType = environValues [CONTENT_TYPE];
params->httpAccept = environValues [HTTP_ACCEPT];
params->httpAcceptLanguage
= environValues [HTTP_ACCEPT_LANGUAGE];
params->httpCookie = environValues [HTTP_COOKIE];
params->browser = environValues [HTTP_USER_AGENT];
}
}
#if defined(DEBUG)
fprintf ( logFile, "} = %p /* openCGIparams () */\n", params );
fflush ( logFile );
#endif
return ( params );
}
char *getCGIparam ( CGIparams *params, char *name )
{
int top = params->paramCount;
int bottom = 0;
int i = ( top + bottom ) >> 1;
int found = -1;
char *value = NULL;
#if defined(DEBUG)
fprintf ( logFile, "getCGIparam ( %p, \"%s\" ) {\n", params, name );
fflush ( logFile );
#endif
while ( top > bottom ) {
int diff = strcmp ( name, params->names [ params->sorted [i]] );
if ( diff > 0 ) {
bottom = i + 1;
} else if ( diff < 0 ) {
top = i;
} else {
found = i;
break;
}
i = ( top + bottom ) >> 1;
}
if ( found > -1 ) value = params->values [params->sorted [found]];
#if defined(DEBUG)
fprintf ( logFile, "} = \"%s\" /* getCGIparam () */\n", value );
fflush ( logFile );
#endif
return ( value );
}
Last updated: Friday, June 12, 2015 03:21:43 AM