pjs/network/main/robotxt.c

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C
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/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
/*** robotxt.c ****************************************************/
/* description: implementation of robots.txt parser */
/********************************************************************
1998-05-23 03:38:40 +04:00
$Revision: 1.3 $
$Date: 1998-05-22 23:38:14 $
*********************************************************************/
#include "xp.h"
#include "xp_str.h"
#include "ntypes.h" /* for MWContext */
#include "net.h"
#include "robotxt.h"
#include "prmem.h"
#include "prthread.h"
#include "prinrval.h"
#include "prio.h" /* for testing */
#define USER_AGENT "User-agent"
#define DISALLOW "Disallow"
#define ALLOW "Allow"
#define ASTERISK "*"
#define MOZILLA "mozilla"
typedef uint8 CRAWL_RobotControlAvailability;
#define ROBOT_CONTROL_AVAILABLE ((CRAWL_RobotControlAvailability)0x00)
#define ROBOT_CONTROL_NOT_AVAILABLE ((CRAWL_RobotControlAvailability)0x01)
#define ROBOT_CONTROL_NOT_YET_QUERIED ((CRAWL_RobotControlAvailability)0x02)
#define PARSE_STATE_ALLOW 1
#define PARSE_STATE_DISALLOW 2
#define PARSE_STATE_AGENT 3
#define PARSE_NO_ERR 0
#define PARSE_ERR 1
#define PARSE_NO_MEMORY 2
#define MOZILLA_RECORD_READ 3 /* found the Mozilla record so we're done */
extern int crawl_appendString(char **str, uint16 *len, uint16 *size, char c);
typedef struct _CRAWL_RobotControlStruct {
/* char *host; */
char *siteURL;
CRAWL_RobotControlAvailability status;
char **line;
uint16 numLines;
uint16 sizeLines;
PRBool *allowed;
MWContext *context;
CRAWL_RobotControlStatusFunc completion_func;
void *owner_data;
PRBool freeData;
/* char *requested_url; */
} CRAWL_RobotControlStruct;
typedef struct _CRAWL_RobotParseStruct {
uint8 state;
char *token;
uint16 lenToken;
uint16 sizeToken;
PRBool inComment;
PRBool isProcessing;
PRBool skipWhitespace;
PRBool mozillaSeen; /* true if we saw a mozilla user agent */
PRBool defaultSeen; /* true if we saw a default user agent */
PRBool foundRecord; /* true if we read a mozilla or default record */
} CRAWL_RobotParseStruct;
typedef CRAWL_RobotParseStruct *CRAWL_RobotParse;
/* prototypes */
static int crawl_unescape (char *str, char *reserved, int numReserved);
PRBool crawl_startsWith (char *pattern, char *uuid);
PRBool crawl_endsWith (char *pattern, char *uuid);
void crawl_stringToLower(char *str);
static void crawl_destroyLines(CRAWL_RobotControl control);
static void crawl_addRobotControlDirective(CRAWL_RobotControl control, char *token, PRBool isAllowed);
static int crawl_parseRobotControlInfo(CRAWL_RobotControl control, CRAWL_RobotParse parse, char *str, uint32 len);
static CRAWL_RobotControlStatus crawl_isRobotAllowed(CRAWL_RobotControl control, char *url);
/* this stuff is adapted from mkparse.c */
#define HEX_ESCAPE '%'
#define RESERVED_CHARS ";/:@=&"
#define NUM_RESERVED 6
/* decode % escaped hex codes into character values
*/
#define UNHEX(C) \
((C >= '0' && C <= '9') ? C - '0' : \
((C >= 'A' && C <= 'F') ? C - 'A' + 10 : \
((C >= 'a' && C <= 'f') ? C - 'a' + 10 : 0)))
/* unescapes a string, but leaves octets encoded if they match one of the supplied reserved characters.
this was adapted from NET_UnescapeCnt */
static int
crawl_unescape (char *str, char *reserved, int numReserved)
{
int i;
register char *src = str;
register char *dst = str;
while(*src)
if (*src != HEX_ESCAPE)
{
*dst++ = *src++;
}
else
{
src++; /* walk over escape */
if (*src)
{
*dst = UNHEX(*src) << 4;
src++;
}
if (*src)
{
*dst = (*dst + UNHEX(*src));
src++;
}
/* check if it belongs to the reserved characters */
for (i = 0; i < numReserved; i++) {
if (*dst == reserved[i]) {
/* put it back */
*dst++ = HEX_ESCAPE;
*dst++ = *(src-2);
*dst = *(src-1);
}
}
dst++;
}
*dst = 0;
return (int)(dst - str);
}
1998-05-23 03:38:40 +04:00
#define CHAR_CMP(x, y) ((x == y) || (NET_TO_LOWER(x) == NET_TO_LOWER(y)))
PRBool crawl_startsWith (char *pattern, char *uuid) {
short l1 = strlen(pattern);
short l2 = strlen(uuid);
short index;
if (l2 < l1) return PR_FALSE;
for (index = 0; index < l1; index++) {
if (!(CHAR_CMP(pattern[index], uuid[index]))) return PR_FALSE;
}
return PR_TRUE;
}
PRBool crawl_endsWith (char *pattern, char *uuid) {
short l1 = strlen(pattern);
short l2 = strlen(uuid);
short index;
if (l2 < l1) return PR_FALSE;
for (index = 0; index < l1; index++) {
if (!(CHAR_CMP(pattern[l1-index], uuid[l2-index]))) return PR_FALSE;
}
return PR_TRUE;
}
void crawl_stringToLower(char *str) {
register char *src = str;
register char *dst = str;
while(*src) {
*dst++ = tolower(*src++);
}
*dst = 0;
}
PR_IMPLEMENT(CRAWL_RobotControl) CRAWL_MakeRobotControl(MWContext *context, char *siteURL) {
CRAWL_RobotControl control = PR_NEWZAP(CRAWL_RobotControlStruct);
if (control == NULL) return(NULL);
control->siteURL = PL_strdup(siteURL);
if (siteURL == NULL) return(NULL);
control->status = ROBOT_CONTROL_NOT_YET_QUERIED;
control->context = context;
return control;
}
static void
crawl_destroyLines(CRAWL_RobotControl control) {
uint16 i;
for (i = 0; i < control->numLines; i++) {
PR_Free(control->line[i]);
}
if (control->line != NULL) PR_Free(control->line);
if (control->allowed != NULL) PR_Free(control->allowed);
control->allowed = NULL;
control->line = NULL;
control->numLines = control->sizeLines = 0;
}
PR_IMPLEMENT(void) CRAWL_DestroyRobotControl(CRAWL_RobotControl control) {
if (control->siteURL != NULL) PR_Free(control->siteURL);
crawl_destroyLines(control);
PR_Free(control);
}
static void
crawl_addRobotControlDirective(CRAWL_RobotControl control, char *token, PRBool isAllowed) {
/* convert token to lower case and unescape it */
crawl_stringToLower(token);
crawl_unescape(token, RESERVED_CHARS, NUM_RESERVED);
if (control->numLines == control->sizeLines) {
char **newLines;
char **old;
PRBool *newAllowed;
PRBool *oldAllowed;
/* copy the paths array */
newLines = (char**)PR_MALLOC(sizeof(char**) * (control->sizeLines + 10));
if (newLines == NULL) return;
old = control->line;
memcpy((char*)newLines, (char*)control->line, (sizeof(char**) * control->numLines));
control->line = newLines;
if (old != NULL) PR_Free(old);
/* copy the boolean array */
newAllowed = (PRBool*)PR_MALLOC(sizeof(PRBool) * (control->sizeLines + 10));
if (newAllowed == NULL) return;
oldAllowed = control->allowed;
memcpy((char*)newAllowed, (char*)control->allowed, (sizeof(PRBool) * control->numLines));
control->allowed = newAllowed;
if (oldAllowed != NULL) PR_Free(oldAllowed);
control->sizeLines += 10;
}
*(control->line + control->numLines) = token;
*(control->allowed + control->numLines) = isAllowed;
control->numLines++;
}
static int
crawl_parseRobotControlInfo(CRAWL_RobotControl control, CRAWL_RobotParse parse, char *str, uint32 len) {
uint32 n = 0; /* where we are in the buffer */
char c;
while (n < len) {
c = *(str + n);
if (parse->skipWhitespace) {
if ((c == ' ') || (c == '\n') || (c == '\r') || (c == '\t')) {
n++;
} else parse->skipWhitespace = PR_FALSE;
} else {
if (c == '#') {
parse->inComment = PR_TRUE;
n++;
} else if (parse->inComment) {
if ((c == '\n') || (c == '\r')) {
parse->inComment = PR_FALSE;
parse->skipWhitespace = PR_TRUE;
n++;
} else n++; /* skip all other characters */
} else if (c == ':') { /* directive */
PRBool mozillaRecordRead = PR_FALSE;
if (crawl_appendString(&parse->token, &parse->lenToken, &parse->sizeToken, '\0') != 0) /* null terminate */
return PARSE_NO_MEMORY;
if (PL_strcasecmp(parse->token, USER_AGENT) == 0) {
if ((parse->state == PARSE_STATE_DISALLOW) || (parse->state == PARSE_STATE_ALLOW)) {
/* already read a disallow or allow directive so the previous record is done */
if (parse->isProcessing) {
if (parse->mozillaSeen) mozillaRecordRead = PR_TRUE;
if (parse->mozillaSeen || parse->defaultSeen) parse->foundRecord = PR_TRUE;
parse->isProcessing = PR_FALSE;
}
}
parse->state = PARSE_STATE_AGENT;
} else if (PL_strcasecmp(parse->token, DISALLOW) == 0) {
parse->state = PARSE_STATE_DISALLOW;
} else if (PL_strcasecmp(parse->token, ALLOW) == 0)
parse->state = PARSE_STATE_ALLOW;
/* else it is an unknown directive */
PR_Free(parse->token);
parse->token = NULL;
parse->lenToken = parse->sizeToken = 0;
parse->skipWhitespace = PR_TRUE;
n++;
if (mozillaRecordRead) return MOZILLA_RECORD_READ; /* read the mozilla record so we're outta here */
} else if ((c == '\n') || (c == '\r')) {
if (crawl_appendString(&parse->token, &parse->lenToken, &parse->sizeToken, '\0') != 0) /* null terminate */
return PARSE_NO_MEMORY;
switch (parse->state) {
case PARSE_STATE_AGENT:
if (PL_strcasestr(parse->token, MOZILLA) != NULL) {
parse->mozillaSeen = PR_TRUE;
crawl_destroyLines(control); /* destroy previous default data */
parse->isProcessing = PR_TRUE; /* start processing */
} else if ((PL_strcmp(parse->token, ASTERISK) == 0) && (!parse->mozillaSeen)) {
parse->defaultSeen = PR_TRUE;
parse->isProcessing = PR_TRUE; /* start processing */
}
PR_Free(parse->token);
break;
case PARSE_STATE_DISALLOW:
/* if processing, add to disallowed */
if (parse->isProcessing) {
crawl_addRobotControlDirective(control, parse->token, PR_FALSE);
}
break;
case PARSE_STATE_ALLOW:
/* if processing, add to allowed */
if (parse->isProcessing) {
crawl_addRobotControlDirective(control, parse->token, PR_TRUE);
}
break;
default:
PR_Free(parse->token);
break;
}
parse->token = NULL;
parse->lenToken = parse->sizeToken = 0;
parse->skipWhitespace = PR_TRUE;
} else {
if (crawl_appendString(&parse->token, &parse->lenToken, &parse->sizeToken, c) != 0)
return PARSE_NO_MEMORY;
n++;
}
}
}
return PARSE_NO_ERR;
}
static CRAWL_RobotControlStatus
crawl_isRobotAllowed(CRAWL_RobotControl control, char *url) {
/* extract file component (after host) from url and decode it */
uint16 i;
char *file = NET_ParseURL(url, GET_PATH_PART);
if (file == NULL) return CRAWL_ROBOT_ALLOWED;
crawl_unescape(file, RESERVED_CHARS, NUM_RESERVED);
for (i = 0; i < control->numLines; i++) {
if (crawl_startsWith(control->line[i], file))
return (control->allowed[i] ? CRAWL_ROBOT_ALLOWED : CRAWL_ROBOT_DISALLOWED);
}
PR_Free(file);
return CRAWL_ROBOT_ALLOWED; /* no matches */
}
static void
crawl_get_robots_txt_exit(URL_Struct *URL_s, int status, MWContext *window_id)
{
#if defined(XP_MAC)
#pragma unused(window_id)
#endif
CRAWL_RobotControl control = (CRAWL_RobotControl)URL_s->owner_data;
if (status < 0) {
control->status = ROBOT_CONTROL_NOT_AVAILABLE;
if (control->owner_data != NULL) {
(control->completion_func)(control->owner_data);
if (control->freeData) PR_DELETE(control->owner_data);
}
}
if(status != MK_CHANGING_CONTEXT)
NET_FreeURLStruct(URL_s);
}
/* issues a request for the robots.txt file.
returns PR_TRUE if the request was issued succesfully, PR_FALSE if not.
*/
PR_IMPLEMENT(PRBool) CRAWL_ReadRobotControlFile(CRAWL_RobotControl control, CRAWL_RobotControlStatusFunc func, void *data, PRBool freeData) {
/* create new cache request for site + /robots.txt" */
char *url = NET_MakeAbsoluteURL(control->siteURL, "/robots.txt");
if (url != NULL) {
URL_Struct *url_s = NET_CreateURLStruct(url, NET_NORMAL_RELOAD);
if (url_s != NULL) {
control->completion_func = func;
control->owner_data = data;
control->freeData = freeData;
url_s->owner_data = control;
NET_GetURL(url_s, FO_CACHE_AND_ROBOTS_TXT, control->context, crawl_get_robots_txt_exit);
/* func(data); */
return PR_TRUE;
}
}
control->status = ROBOT_CONTROL_NOT_AVAILABLE;
return PR_FALSE;
}
PR_IMPLEMENT(CRAWL_RobotControlStatus) CRAWL_GetRobotControl(CRAWL_RobotControl control, char *url) {
/* return ROBOT_ALLOWED; */
switch (control->status) {
case ROBOT_CONTROL_NOT_YET_QUERIED:
return CRAWL_ROBOTS_TXT_NOT_QUERIED;
case ROBOT_CONTROL_AVAILABLE:
return crawl_isRobotAllowed(control, url);
break;
case ROBOT_CONTROL_NOT_AVAILABLE:
return CRAWL_ROBOT_ALLOWED; /* no robots.txt file found so assume we can crawl */
break;
default:
return CRAWL_ROBOT_ALLOWED;
break;
}
}
/* content type conversion */
typedef struct {
CRAWL_RobotParse parse_obj;
CRAWL_RobotControl control;
} crawl_robots_txt_stream;
PRIVATE int
crawl_RobotsTxtConvPut(NET_StreamClass *stream, char *s, int32 l)
{
crawl_robots_txt_stream *obj=stream->data_object;
int status = crawl_parseRobotControlInfo(obj->control, obj->parse_obj, s, l);
if ((status == MOZILLA_RECORD_READ) ||
(status == PARSE_NO_MEMORY)) {
return (MK_UNABLE_TO_CONVERT); /* abort since we read the mozilla record, no need to read any others */
}
return(status);
}
PRIVATE int
crawl_RobotsTxtConvWriteReady(NET_StreamClass *stream)
{
#if defined(XP_MAC)
#pragma unused(stream)
#endif
return(MAX_WRITE_READY);
}
PRIVATE void
crawl_RobotsTxtConvComplete(NET_StreamClass *stream)
{
crwal_robots_txt_stream*obj=stream->data_object;
if (obj->parse_obj->foundRecord) obj->control->status = ROBOT_CONTROL_AVAILABLE;
if (obj->control->owner_data != NULL) {
(obj->control->completion_func)(obj->control->owner_data);
if (obj->control->freeData) PR_DELETE(obj->control->owner_data);
}
PR_Free(obj->parse_obj);
}
PRIVATE void
crawl_RobotsTxtConvAbort(NET_StreamClass *stream, int status)
{
crawl_robots_txt_stream *obj=stream->data_object;
if(status == MK_UNABLE_TO_CONVERT) { /* special case, we read the mozilla record and exited early */
obj->control->status = ROBOT_CONTROL_AVAILABLE;
} else obj->control->status = ROBOT_CONTROL_NOT_AVAILABLE;
if (obj->control->owner_data != NULL) {
(obj->control->completion_func)(obj->control->owner_data);
if (obj->control->freeData) PR_DELETE(obj->control->owner_data);
}
PR_Free(obj->parse_obj);
}
PUBLIC NET_StreamClass *
CRAWL_RobotsTxtConverter(int format_out,
void *data_object,
URL_Struct *URL_s,
MWContext *window_id)
{
#if defined(XP_MAC)
#pragma unused(format_out, data_object)
#endif
crawl_robots_txt_stream *obj;
NET_StreamClass *stream;
CRAWL_RobotControl control = (CRAWL_RobotControl)URL_s->owner_data;
TRACEMSG(("Setting up display stream. Have URL: %s\n", URL_s->address));
if (URL_s->server_status < 400) {
stream = PR_NEW(NET_StreamClass);
if(stream == NULL) {
control->status = ROBOT_CONTROL_NOT_AVAILABLE;
return(NULL);
}
obj = PR_NEW(crawl_robots_txt_stream);
if (obj == NULL)
{
PR_Free(stream);
control->status = ROBOT_CONTROL_NOT_AVAILABLE;
return(NULL);
}
obj->parse_obj = PR_NEWZAP(CRAWL_RobotParseStruct);
if (obj->parse_obj == NULL) return(NULL);
obj->control = URL_s->owner_data;
stream->name = "robots.txt Converter";
stream->complete = (MKStreamCompleteFunc) crawl_RobotsTxtConvComplete;
stream->abort = (MKStreamAbortFunc) crawl_RobotsTxtConvAbort;
stream->put_block = (MKStreamWriteFunc) crawl_RobotsTxtConvPut;
stream->is_write_ready = (MKStreamWriteReadyFunc) crawl_RobotsTxtConvWriteReady;
stream->data_object = obj; /* document info object */
stream->window_id = window_id;
return(stream);
} else {
control->status = ROBOT_CONTROL_NOT_AVAILABLE;
if (control->owner_data != NULL) {
control->completion_func(control->owner_data);
if (control->freeData) PR_DELETE(control->owner_data);
}
return (NULL);
}
}
#if DEBUG_TEST_ROBOT
void testRobotControlParser(char *url) {
/* this will be done through libnet but for now use PR_OpenFile */
PRFileDesc *fp;
int32 len;
char *path;
static char buf[512]; /* xxx alloc */
CRAWL_RobotParse parse;
CRAWL_RobotControl control = MakeRobotControl("foo");
/* XXX need to unescape URL */
path=&(url[8]);
fp = PR_Open(path, PR_RDONLY, 0644);
if(fp == NULL)
{
return;
}
parse = PR_NEWZAP(CRAWL_RobotParseStruct);
while((len=PR_Read(fp, buf, 512))>0) {
if (crawl_parseRobotControlInfo(control, parse, buf, len) == MOZILLA_RECORD_READ) break;
}
PR_Close(fp);
PR_Free(parse);
DestroyRobotControl(control);
return;
}
#endif