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gnupg/util/http.c

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/* http.c - HTTP protocol handler
* Copyright (C) 1999, 2001, 2002, 2003 Free Software Foundation, Inc.
*
* This file is part of GnuPG.
*
* GnuPG is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* GnuPG is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include <config.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#ifdef _WIN32
#include <windows.h>
#else
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <netdb.h>
#endif
#include "util.h"
#include "iobuf.h"
#include "i18n.h"
#include "http.h"
#include "srv.h"
#ifdef __riscos__
#define HTTP_PROXY_ENV "GnuPG$HttpProxy"
#define HTTP_PROXY_ENV_PRINTABLE "<GnuPG$HttpProxy>"
#else
#define HTTP_PROXY_ENV "http_proxy"
#define HTTP_PROXY_ENV_PRINTABLE "$http_proxy"
#endif
#ifdef _WIN32
#define sock_close(a) closesocket(a)
#else
#define sock_close(a) close(a)
#endif
#define MAX_LINELEN 20000 /* max. length of a HTTP line */
#define VALID_URI_CHARS "abcdefghijklmnopqrstuvwxyz" \
"ABCDEFGHIJKLMNOPQRSTUVWXYZ" \
"01234567890@" \
"!\"#$%&'()*+,-./:;<=>?[\\]^_{|}~"
#ifndef EAGAIN
#define EAGAIN EWOULDBLOCK
#endif
static int parse_uri( PARSED_URI *ret_uri, const char *uri );
static void release_parsed_uri( PARSED_URI uri );
static int do_parse_uri( PARSED_URI uri, int only_local_part );
static int remove_escapes( byte *string );
static int insert_escapes( byte *buffer, const byte *string,
const byte *special );
static URI_TUPLE parse_tuple( byte *string );
static int send_request( HTTP_HD hd );
static byte *build_rel_path( PARSED_URI uri );
static int parse_response( HTTP_HD hd );
static int connect_server(const char *server, ushort port, unsigned int flags);
static int write_server( int sock, const char *data, size_t length );
#ifdef _WIN32
static void
deinit_sockets (void)
{
WSACleanup();
}
static void
init_sockets (void)
{
static int initialized;
static WSADATA wsdata;
if (initialized)
return;
if( WSAStartup( 0x0101, &wsdata ) ) {
log_error ("error initializing socket library: ec=%d\n",
(int)WSAGetLastError () );
return;
}
if( wsdata.wVersion < 0x0001 ) {
log_error ("socket library version is %x.%x - but 1.1 needed\n",
LOBYTE(wsdata.wVersion), HIBYTE(wsdata.wVersion));
WSACleanup();
return;
}
atexit ( deinit_sockets );
initialized = 1;
}
#endif /*_WIN32*/
int
http_open( HTTP_HD hd, HTTP_REQ_TYPE reqtype, const char *url,
unsigned int flags )
{
int rc;
if( !(reqtype == HTTP_REQ_GET || reqtype == HTTP_REQ_POST) )
return G10ERR_INV_ARG;
/* initialize the handle */
memset( hd, 0, sizeof *hd );
hd->sock = -1;
hd->initialized = 1;
hd->req_type = reqtype;
hd->flags = flags;
rc = parse_uri( &hd->uri, url );
if( !rc ) {
rc = send_request( hd );
if( !rc ) {
hd->fp_write = iobuf_sockopen( hd->sock , "w" );
if( hd->fp_write )
return 0;
rc = G10ERR_GENERAL;
}
}
if( !hd->fp_read && !hd->fp_write && hd->sock != -1 )
sock_close( hd->sock );
iobuf_close( hd->fp_read );
iobuf_close( hd->fp_write);
release_parsed_uri( hd->uri );
hd->initialized = 0;
return rc;
}
void
http_start_data( HTTP_HD hd )
{
iobuf_flush ( hd->fp_write );
if( !hd->in_data ) {
write_server (hd->sock, "\r\n", 2);
hd->in_data = 1;
}
}
int
http_wait_response( HTTP_HD hd, unsigned int *ret_status )
{
int rc;
http_start_data( hd ); /* make sure that we are in the data */
#if 0
hd->sock = dup( hd->sock );
if( hd->sock == -1 )
return G10ERR_GENERAL;
#endif
iobuf_ioctl (hd->fp_write, 1, 1, NULL); /* keep the socket open */
iobuf_close (hd->fp_write);
hd->fp_write = NULL;
if ( !(hd->flags & HTTP_FLAG_NO_SHUTDOWN) )
shutdown( hd->sock, 1 );
hd->in_data = 0;
hd->fp_read = iobuf_sockopen( hd->sock , "r" );
if( !hd->fp_read )
return G10ERR_GENERAL;
rc = parse_response( hd );
if( !rc && ret_status )
*ret_status = hd->status_code;
return rc;
}
int
http_open_document( HTTP_HD hd, const char *document, unsigned int flags )
{
int rc;
rc = http_open( hd, HTTP_REQ_GET, document, flags );
if( rc )
return rc;
rc = http_wait_response( hd, NULL );
if( rc )
http_close( hd );
return rc;
}
void
http_close( HTTP_HD hd )
{
if( !hd || !hd->initialized )
return;
if( !hd->fp_read && !hd->fp_write && hd->sock != -1 )
sock_close( hd->sock );
iobuf_close( hd->fp_read );
iobuf_close( hd->fp_write );
release_parsed_uri( hd->uri );
m_free( hd->buffer );
hd->initialized = 0;
}
/****************
* Parse an URI and put the result into the newly allocated ret_uri.
* The caller must always use release_parsed_uri to releases the
* resources (even on an error).
*/
static int
parse_uri( PARSED_URI *ret_uri, const char *uri )
{
*ret_uri = m_alloc_clear( sizeof(**ret_uri) + strlen(uri) );
strcpy( (*ret_uri)->buffer, uri );
return do_parse_uri( *ret_uri, 0 );
}
static void
release_parsed_uri( PARSED_URI uri )
{
if( uri )
{
URI_TUPLE r, r2;
for( r = uri->query; r; r = r2 ) {
r2 = r->next;
m_free( r );
}
m_free( uri );
}
}
static int
do_parse_uri( PARSED_URI uri, int only_local_part )
{
URI_TUPLE *tail;
char *p, *p2, *p3;
int n;
p = uri->buffer;
n = strlen( uri->buffer );
/* initialize all fields to an empty string or an empty list */
uri->scheme = uri->host = uri->path = p + n;
uri->port = 0;
uri->params = uri->query = NULL;
/* a quick validity check */
if( strspn( p, VALID_URI_CHARS) != n )
return G10ERR_BAD_URI; /* invalid characters found */
if( !only_local_part ) {
/* find the scheme */
if( !(p2 = strchr( p, ':' ) ) || p2 == p )
return G10ERR_BAD_URI; /* No scheme */
*p2++ = 0;
strlwr( p );
uri->scheme = p;
uri->port = 80;
if( !strcmp( uri->scheme, "http" ) )
;
else if( !strcmp( uri->scheme, "x-hkp" ) ) /* same as HTTP */
uri->port = 11371;
else
return G10ERR_INVALID_URI; /* Unsupported scheme */
p = p2;
/* find the hostname */
if( *p != '/' )
return G10ERR_INVALID_URI; /* does not start with a slash */
p++;
if( *p == '/' ) { /* there seems to be a hostname */
p++;
if( (p2 = strchr(p, '/')) )
*p2++ = 0;
strlwr( p );
uri->host = p;
if( (p3=strchr( p, ':' )) ) {
*p3++ = 0;
uri->port = atoi( p3 );
}
uri->host = p;
if( (n = remove_escapes( uri->host )) < 0 )
return G10ERR_BAD_URI;
if( n != strlen( p ) )
return G10ERR_BAD_URI; /* hostname with a Nul in it */
p = p2 ? p2 : NULL;
}
} /* end global URI part */
/* parse the pathname part */
if( !p || !*p ) /* we don't have a path */
return 0; /* and this is okay */
/* todo: here we have to check params */
/* do we have a query part */
if( (p2 = strchr( p, '?' )) )
*p2++ = 0;
uri->path = p;
if( (n = remove_escapes( p )) < 0 )
return G10ERR_BAD_URI;
if( n != strlen( p ) )
return G10ERR_BAD_URI; /* path with a Nul in it */
p = p2 ? p2 : NULL;
if( !p || !*p ) /* we don't have a query string */
return 0; /* okay */
/* now parse the query string */
tail = &uri->query;
for(;;) {
URI_TUPLE elem;
if( (p2 = strchr( p, '&' )) )
*p2++ = 0;
if( !(elem = parse_tuple( p )) )
return G10ERR_BAD_URI;
*tail = elem;
tail = &elem->next;
if( !p2 )
break; /* ready */
p = p2;
}
return 0;
}
/****************
* Remove all %xx escapes; this is done inplace.
* Returns: new length of the string.
*/
static int
remove_escapes( byte *string )
{
int n = 0;
byte *p, *s;
for(p=s=string; *s ; s++ ) {
if( *s == '%' ) {
if( s[1] && s[2] && isxdigit(s[1]) && isxdigit(s[2]) ) {
s++;
*p = *s >= '0' && *s <= '9' ? *s - '0' :
*s >= 'A' && *s <= 'F' ? *s - 'A' + 10 : *s - 'a' + 10 ;
*p <<= 4;
s++;
*p |= *s >= '0' && *s <= '9' ? *s - '0' :
*s >= 'A' && *s <= 'F' ? *s - 'A' + 10 : *s - 'a' + 10 ;
p++;
n++;
}
else {
*p++ = *s++;
if( *s )
*p++ = *s++;
if( *s )
*p++ = *s++;
if( *s )
*p = 0;
return -1; /* bad URI */
}
}
else
{
*p++ = *s;
n++;
}
}
*p = 0; /* always keep a string terminator */
return n;
}
static int
insert_escapes( byte *buffer, const byte *string, const byte *special )
{
int n = 0;
for( ; *string; string++ ) {
if( strchr( VALID_URI_CHARS, *string )
&& !strchr( special, *string ) ) {
if( buffer )
*buffer++ = *string;
n++;
}
else {
if( buffer ) {
sprintf( buffer, "%02X", *string );
buffer += 3;
}
n += 3;
}
}
return n;
}
static URI_TUPLE
parse_tuple( byte *string )
{
byte *p = string;
byte *p2;
int n;
URI_TUPLE tuple;
if( (p2 = strchr( p, '=' )) )
*p2++ = 0;
if( (n = remove_escapes( p )) < 0 )
return NULL; /* bad URI */
if( n != strlen( p ) )
return NULL; /* name with a Nul in it */
tuple = m_alloc_clear( sizeof *tuple );
tuple->name = p;
if( !p2 ) {
/* we have only the name, so we assume an empty value string */
tuple->value = p + strlen(p);
tuple->valuelen = 0;
}
else { /* name and value */
if( (n = remove_escapes( p2 )) < 0 ) {
m_free( tuple );
return NULL; /* bad URI */
}
tuple->value = p2;
tuple->valuelen = n;
}
return tuple;
}
/****************
* Send a HTTP request to the server
* Returns 0 if the request was successful
*/
static int
send_request( HTTP_HD hd )
{
const byte *server;
byte *request, *p;
ushort port;
int rc;
const char *http_proxy = NULL;
server = *hd->uri->host? hd->uri->host : "localhost";
port = hd->uri->port? hd->uri->port : 80;
if( (hd->flags & HTTP_FLAG_TRY_PROXY)
&& (http_proxy = getenv( HTTP_PROXY_ENV )) ) {
PARSED_URI uri;
rc = parse_uri( &uri, http_proxy );
if (rc) {
log_error("invalid " HTTP_PROXY_ENV_PRINTABLE ": %s\n",
g10_errstr(rc));
release_parsed_uri( uri );
return G10ERR_NETWORK;
}
hd->sock = connect_server( *uri->host? uri->host : "localhost",
uri->port? uri->port : 80, 0 );
release_parsed_uri( uri );
}
else
hd->sock = connect_server( server, port, hd->flags );
if( hd->sock == -1 )
return G10ERR_NETWORK;
p = build_rel_path( hd->uri );
request = m_alloc( strlen(server) + strlen(p) + 50 );
if( http_proxy ) {
sprintf( request, "%s http://%s:%hu%s%s HTTP/1.0\r\n",
hd->req_type == HTTP_REQ_GET ? "GET" :
hd->req_type == HTTP_REQ_HEAD? "HEAD":
hd->req_type == HTTP_REQ_POST? "POST": "OOPS",
server, port, *p == '/'? "":"/", p );
}
else {
sprintf( request, "%s %s%s HTTP/1.0\r\n",
hd->req_type == HTTP_REQ_GET ? "GET" :
hd->req_type == HTTP_REQ_HEAD? "HEAD":
hd->req_type == HTTP_REQ_POST? "POST": "OOPS",
*p == '/'? "":"/", p );
}
m_free(p);
rc = write_server( hd->sock, request, strlen(request) );
m_free( request );
return rc;
}
/****************
* Build the relative path from the parsed URI.
* Minimal implementation.
*/
static byte*
build_rel_path( PARSED_URI uri )
{
URI_TUPLE r;
byte *rel_path, *p;
int n;
/* count the needed space */
n = insert_escapes( NULL, uri->path, "%;?&" );
/* todo: build params */
for( r=uri->query; r; r = r->next ) {
n++; /* '?'/'&' */
n += insert_escapes( NULL, r->name, "%;?&=" );
n++; /* '='*/
n += insert_escapes( NULL, r->value, "%;?&=" );
}
n++;
/* now allocate and copy */
p = rel_path = m_alloc( n );
n = insert_escapes( p, uri->path, "%;?&" );
p += n;
/* todo: add params */
for( r=uri->query; r; r = r->next ) {
*p++ = r == uri->query? '?':'&';
n = insert_escapes( p, r->name, "%;?&=" );
p += n;
*p++ = '=';
/* todo: use valuelen */
n = insert_escapes( p, r->value, "%;?&=" );
p += n;
}
*p = 0;
return rel_path;
}
/***********************
* Parse the response from a server.
* Returns: errorcode and sets some fileds in the handle
*/
static int
parse_response( HTTP_HD hd )
{
byte *line, *p, *p2;
unsigned maxlen, len;
/* Wait for the status line */
do {
maxlen = MAX_LINELEN;
len = iobuf_read_line( hd->fp_read, &hd->buffer,
&hd->buffer_size, &maxlen );
line = hd->buffer;
if( !maxlen )
return -1; /* line has been truncated */
if( !len )
return -1; /* eof */
} while( !*line );
if( (p = strchr( line, '/')) )
*p++ = 0;
if( !p || strcmp( line, "HTTP" ) )
return 0; /* assume http 0.9 */
if( (p2 = strpbrk( p, " \t" ) ) ) {
*p2++ = 0;
p2 += strspn( p2, " \t" );
}
if( !p2 )
return 0; /* assume http 0.9 */
p = p2;
/* todo: add HTTP version number check here */
if( (p2 = strpbrk( p, " \t" ) ) )
*p2++ = 0;
if( !isdigit(p[0]) || !isdigit(p[1]) || !isdigit(p[2]) || p[3] ) {
/* malformed HTTP statuscode - assume HTTP 0.9 */
hd->is_http_0_9 = 1;
hd->status_code = 200;
return 0;
}
hd->status_code = atoi( p );
/* skip all the header lines and wait for the empty line */
do {
maxlen = MAX_LINELEN;
len = iobuf_read_line( hd->fp_read, &hd->buffer,
&hd->buffer_size, &maxlen );
line = hd->buffer;
/* we ignore truncated lines */
if( !len )
return -1; /* eof */
/* time lineendings */
if( (*line == '\r' && line[1] == '\n') || *line == '\n' )
*line = 0;
} while( len && *line );
return 0;
}
#if 0
static int
start_server()
{
struct sockaddr_in mya;
struct sockaddr_in peer;
int fd, client;
fd_set rfds;
int addrlen;
int i;
if( (fd=socket(AF_INET,SOCK_STREAM, 0)) == -1 ) {
log_error("socket() failed: %s\n", strerror(errno));
return -1;
}
i = 1;
if( setsockopt( fd, SOL_SOCKET, SO_REUSEADDR, (byte*)&i, sizeof(i) ) )
log_info("setsockopt(SO_REUSEADDR) failed: %s\n", strerror(errno) );
mya.sin_family=AF_INET;
memset(&mya.sin_addr, 0, sizeof(mya.sin_addr));
mya.sin_port=htons(11371);
if( bind( fd, (struct sockaddr *)&mya, sizeof(mya)) ) {
log_error("bind to port 11371 failed: %s\n", strerror(errno) );
sock_close( fd );
return -1;
}
if( listen( fd, 5 ) ) {
log_error("listen failed: %s\n", strerror(errno) );
sock_close( fd );
return -1;
}
for(;;) {
FD_ZERO(&rfds);
FD_SET( fd, &rfds );
if( select( fd+1, &rfds, NULL, NULL, NULL) <= 0 )
continue; /* ignore any errors */
if( !FD_ISSET( fd, &rfds ) )
continue;
addrlen = sizeof peer;
client = accept( fd, (struct sockaddr *)&peer, &addrlen);
if( client == -1 )
continue; /* oops */
log_info("connect from %s\n", inet_ntoa( peer.sin_addr ) );
fflush(stdout);
fflush(stderr);
if( !fork() ) {
int c;
FILE *fp;
fp = fdopen( client , "r" );
while( (c=getc(fp)) != EOF )
putchar(c);
fclose(fp);
exit(0);
}
sock_close( client );
}
return 0;
}
#endif
static int
connect_server( const char *server, ushort port, unsigned int flags )
{
int sock=-1,srv,srvcount=0,connected=0;
struct srventry *srvlist=NULL;
#ifdef _WIN32
unsigned long inaddr;
init_sockets();
/* Win32 gethostbyname doesn't handle IP addresses internally, so we
try inet_addr first on that platform only. */
if((inaddr=inet_addr(server))!=SOCKET_ERROR)
{
struct sockaddr_in addr;
memset(&addr,0,sizeof(addr));
if((sock=socket(AF_INET,SOCK_STREAM,0))==INVALID_SOCKET)
{
log_error("error creating socket: ec=%d\n",(int)WSAGetLastError());
return -1;
}
addr.sin_family=AF_INET;
addr.sin_port=htons(port);
if(connect(sock,(struct sockaddr *)&addr,sizeof(addr))==0)
return sock;
else
{
sock_close(sock);
return -1;
}
}
#endif
#ifdef USE_DNS_SRV
/* Do the SRV thing */
if(flags&HTTP_FLAG_TRY_SRV)
{
/* We're using SRV, so append the tags */
char srvname[MAXDNAME];
strcpy(srvname,"_hkp._tcp.");
strncat(srvname,server,MAXDNAME-11);
srvname[MAXDNAME-1]='\0';
srvcount=getsrv(srvname,&srvlist);
}
#endif
if(srvlist==NULL)
{
/* Either we're not using SRV, or the SRV lookup failed. Make
up a fake SRV record. */
srvlist=m_alloc_clear(sizeof(struct srventry));
srvlist->port=port;
strncpy(srvlist->target,server,MAXDNAME);
srvcount=1;
}
#ifdef HAVE_GETADDRINFO
for(srv=0;srv<srvcount;srv++)
{
struct addrinfo hints,*res,*ai;
char portstr[6];
sprintf(portstr,"%u",srvlist[srv].port);
memset(&hints,0,sizeof(hints));
hints.ai_socktype=SOCK_STREAM;
if(getaddrinfo(srvlist[srv].target,portstr,&hints,&res)!=0)
continue;
for(ai=res;ai;ai=ai->ai_next)
{
if((sock=socket(ai->ai_family,ai->ai_socktype,ai->ai_protocol))==-1)
{
log_error("error creating socket: %s\n",strerror(errno));
freeaddrinfo(res);
return -1;
}
if(connect(sock,ai->ai_addr,ai->ai_addrlen)==0)
{
connected=1;
break;
}
}
freeaddrinfo(res);
if(ai)
break;
}
#else /* !HAVE_GETADDRINFO */
for(srv=0;srv<srvcount;srv++)
{
int i=0;
struct hostent *host=NULL;
struct sockaddr_in addr;
memset(&addr,0,sizeof(addr));
if((host=gethostbyname(srvlist[srv].target))==NULL)
continue;
if((sock=socket(host->h_addrtype,SOCK_STREAM,0))==-1)
{
log_error("error creating socket: %s\n",strerror(errno));
return -1;
}
addr.sin_family=host->h_addrtype;
addr.sin_port=htons(srvlist[srv].port);
/* Try all A records until one responds. */
while(host->h_addr_list[i])
{
memcpy(&addr.sin_addr,host->h_addr_list[i],host->h_length);
if(connect(sock,(struct sockaddr *)&addr,sizeof(addr))==0)
{
connected=1;
break;
}
i++;
}
if(host->h_addr_list[i])
break;
}
#endif /* !HAVE_GETADDRINFO */
m_free(srvlist);
if(!connected)
{
#ifdef _WIN32
log_error("%s: host not found: ec=%d\n",server,(int)WSAGetLastError());
#else
log_error("%s: host not found\n",server);
#endif
if(sock!=-1)
sock_close(sock);
return -1;
}
return sock;
}
static int
write_server( int sock, const char *data, size_t length )
{
int nleft;
nleft = length;
while( nleft > 0 ) {
#ifdef _WIN32
int nwritten;
nwritten = send (sock, data, nleft, 0);
if ( nwritten == SOCKET_ERROR ) {
log_info ("write failed: ec=%d\n", (int)WSAGetLastError ());
return G10ERR_NETWORK;
}
#else
int nwritten = write( sock, data, nleft );
if( nwritten == -1 ) {
if( errno == EINTR )
continue;
if( errno == EAGAIN ) {
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 50000;
select(0, NULL, NULL, NULL, &tv);
continue;
}
log_info("write failed: %s\n", strerror(errno));
return G10ERR_NETWORK;
}
#endif
nleft -=nwritten;
data += nwritten;
}
return 0;
}
/**** Test code ****/
#ifdef TEST
int
main(int argc, char **argv)
{
int rc;
PARSED_URI uri;
URI_TUPLE r;
struct http_context hd;
int c;
log_set_name("http-test");
if( argc == 1 ) {
start_server();
return 0;
}
if( argc != 2 ) {
fprintf(stderr,"usage: http-test uri\n");
return 1;
}
argc--; argv++;
rc = parse_uri( &uri, *argv );
if( rc ) {
log_error("`%s': %s\n", *argv, g10_errstr(rc));
release_parsed_uri( uri );
return 1;
}
printf("Scheme: %s\n", uri->scheme );
printf("Host : %s\n", uri->host );
printf("Port : %u\n", uri->port );
printf("Path : %s\n", uri->path );
for( r=uri->params; r; r = r->next ) {
printf("Params: %s=%s", r->name, r->value );
if( strlen( r->value ) != r->valuelen )
printf(" [real length=%d]", (int)r->valuelen );
putchar('\n');
}
for( r=uri->query; r; r = r->next ) {
printf("Query : %s=%s", r->name, r->value );
if( strlen( r->value ) != r->valuelen )
printf(" [real length=%d]", (int)r->valuelen );
putchar('\n');
}
release_parsed_uri( uri ); uri = NULL;
rc = http_open_document( &hd, *argv, 0 );
if( rc ) {
log_error("can't get `%s': %s\n", *argv, g10_errstr(rc));
return 1;
}
log_info("open_http_document succeeded; status=%u\n", hd.status_code );
while( (c=iobuf_get( hd.fp_read)) != -1 )
putchar(c);
http_close( &hd );
return 0;
}
#endif /*TEST*/
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