Sweden-Number/server/request.c

789 lines
22 KiB
C

/*
* Server-side request handling
*
* Copyright (C) 1998 Alexandre Julliard
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include "config.h"
#include "wine/port.h"
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_PWD_H
#include <pwd.h>
#endif
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#ifdef HAVE_SYS_SOCKET_H
# include <sys/socket.h>
#endif
#ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h>
#endif
#ifdef HAVE_SYS_UIO_H
#include <sys/uio.h>
#endif
#ifdef HAVE_SYS_UN_H
#include <sys/un.h>
#endif
#include <unistd.h>
#include "windef.h"
#include "winbase.h"
#include "wincon.h"
#include "wine/library.h"
#include "file.h"
#include "handle.h"
#include "thread.h"
#include "process.h"
#include "user.h"
#define WANT_REQUEST_HANDLERS
#include "request.h"
/* Some versions of glibc don't define this */
#ifndef SCM_RIGHTS
#define SCM_RIGHTS 1
#endif
/* path names for server master Unix socket */
static const char * const server_socket_name = "socket"; /* name of the socket file */
static const char * const server_lock_name = "lock"; /* name of the server lock file */
struct master_socket
{
struct object obj; /* object header */
struct timeout_user *timeout; /* timeout on last process exit */
};
static void master_socket_dump( struct object *obj, int verbose );
static void master_socket_poll_event( struct object *obj, int event );
static const struct object_ops master_socket_ops =
{
sizeof(struct master_socket), /* size */
master_socket_dump, /* dump */
no_add_queue, /* add_queue */
NULL, /* remove_queue */
NULL, /* signaled */
NULL, /* satisfied */
no_get_fd, /* get_fd */
no_get_file_info, /* get_file_info */
no_destroy /* destroy */
};
static const struct fd_ops master_socket_fd_ops =
{
NULL, /* get_poll_events */
master_socket_poll_event, /* poll_event */
no_flush, /* flush */
no_get_file_info, /* get_file_info */
no_queue_async /* queue_async */
};
struct thread *current = NULL; /* thread handling the current request */
unsigned int global_error = 0; /* global error code for when no thread is current */
unsigned int server_start_ticks = 0; /* tick count offset from server startup */
static struct master_socket *master_socket; /* the master socket object */
/* socket communication static structures */
static struct iovec myiovec;
static struct msghdr msghdr;
#ifndef HAVE_MSGHDR_ACCRIGHTS
struct cmsg_fd
{
int len; /* sizeof structure */
int level; /* SOL_SOCKET */
int type; /* SCM_RIGHTS */
int fd; /* fd to pass */
};
static struct cmsg_fd cmsg = { sizeof(cmsg), SOL_SOCKET, SCM_RIGHTS, -1 };
#endif /* HAVE_MSGHDR_ACCRIGHTS */
/* complain about a protocol error and terminate the client connection */
void fatal_protocol_error( struct thread *thread, const char *err, ... )
{
va_list args;
va_start( args, err );
fprintf( stderr, "Protocol error:%p: ", thread );
vfprintf( stderr, err, args );
va_end( args );
thread->exit_code = 1;
kill_thread( thread, 1 );
}
/* complain about a protocol error and terminate the client connection */
void fatal_protocol_perror( struct thread *thread, const char *err, ... )
{
va_list args;
va_start( args, err );
fprintf( stderr, "Protocol error:%p: ", thread );
vfprintf( stderr, err, args );
perror( " " );
va_end( args );
thread->exit_code = 1;
kill_thread( thread, 1 );
}
/* die on a fatal error */
void fatal_error( const char *err, ... )
{
va_list args;
va_start( args, err );
fprintf( stderr, "wineserver: " );
vfprintf( stderr, err, args );
va_end( args );
exit(1);
}
/* die on a fatal error */
void fatal_perror( const char *err, ... )
{
va_list args;
va_start( args, err );
fprintf( stderr, "wineserver: " );
vfprintf( stderr, err, args );
perror( " " );
va_end( args );
exit(1);
}
/* allocate the reply data */
void *set_reply_data_size( size_t size )
{
assert( size <= get_reply_max_size() );
if (size && !(current->reply_data = mem_alloc( size ))) size = 0;
current->reply_size = size;
return current->reply_data;
}
/* write the remaining part of the reply */
void write_reply( struct thread *thread )
{
int ret;
if ((ret = write( thread->reply_fd,
(char *)thread->reply_data + thread->reply_size - thread->reply_towrite,
thread->reply_towrite )) >= 0)
{
if (!(thread->reply_towrite -= ret))
{
free( thread->reply_data );
thread->reply_data = NULL;
/* sent everything, can go back to waiting for requests */
change_select_fd( &thread->obj, thread->request_fd, POLLIN );
}
return;
}
if (errno == EPIPE)
kill_thread( thread, 0 ); /* normal death */
else if (errno != EWOULDBLOCK && errno != EAGAIN)
fatal_protocol_perror( thread, "reply write" );
}
/* send a reply to the current thread */
static void send_reply( union generic_reply *reply )
{
int ret;
if (!current->reply_size)
{
if ((ret = write( current->reply_fd, reply, sizeof(*reply) )) != sizeof(*reply)) goto error;
}
else
{
struct iovec vec[2];
vec[0].iov_base = (void *)reply;
vec[0].iov_len = sizeof(*reply);
vec[1].iov_base = current->reply_data;
vec[1].iov_len = current->reply_size;
if ((ret = writev( current->reply_fd, vec, 2 )) < sizeof(*reply)) goto error;
if ((current->reply_towrite = current->reply_size - (ret - sizeof(*reply))))
{
/* couldn't write it all, wait for POLLOUT */
change_select_fd( &current->obj, current->reply_fd, POLLOUT );
return;
}
}
if (current->reply_data)
{
free( current->reply_data );
current->reply_data = NULL;
}
return;
error:
if (ret >= 0)
fatal_protocol_error( current, "partial write %d\n", ret );
else if (errno == EPIPE)
kill_thread( current, 0 ); /* normal death */
else
fatal_protocol_perror( current, "reply write" );
}
/* call a request handler */
static void call_req_handler( struct thread *thread )
{
union generic_reply reply;
enum request req = thread->req.request_header.req;
current = thread;
current->reply_size = 0;
clear_error();
memset( &reply, 0, sizeof(reply) );
if (debug_level) trace_request();
if (req < REQ_NB_REQUESTS)
{
req_handlers[req]( &current->req, &reply );
if (current)
{
reply.reply_header.error = current->error;
reply.reply_header.reply_size = current->reply_size;
if (debug_level) trace_reply( req, &reply );
send_reply( &reply );
}
current = NULL;
return;
}
fatal_protocol_error( current, "bad request %d\n", req );
}
/* read a request from a thread */
void read_request( struct thread *thread )
{
int ret;
if (!thread->req_toread) /* no pending request */
{
if ((ret = read( thread->obj.fd, &thread->req,
sizeof(thread->req) )) != sizeof(thread->req)) goto error;
if (!(thread->req_toread = thread->req.request_header.request_size))
{
/* no data, handle request at once */
call_req_handler( thread );
return;
}
if (!(thread->req_data = malloc( thread->req_toread )))
fatal_protocol_error( thread, "no memory for %d bytes request\n", thread->req_toread );
}
/* read the variable sized data */
for (;;)
{
ret = read( thread->obj.fd, ((char *)thread->req_data +
thread->req.request_header.request_size - thread->req_toread),
thread->req_toread );
if (ret <= 0) break;
if (!(thread->req_toread -= ret))
{
call_req_handler( thread );
free( thread->req_data );
thread->req_data = NULL;
return;
}
}
error:
if (!ret) /* closed pipe */
kill_thread( thread, 0 );
else if (ret > 0)
fatal_protocol_error( thread, "partial read %d\n", ret );
else if (errno != EWOULDBLOCK && errno != EAGAIN)
fatal_protocol_perror( thread, "read" );
}
/* receive a file descriptor on the process socket */
int receive_fd( struct process *process )
{
struct send_fd data;
int fd, ret;
#ifdef HAVE_MSGHDR_ACCRIGHTS
msghdr.msg_accrightslen = sizeof(int);
msghdr.msg_accrights = (void *)&fd;
#else /* HAVE_MSGHDR_ACCRIGHTS */
msghdr.msg_control = &cmsg;
msghdr.msg_controllen = sizeof(cmsg);
cmsg.fd = -1;
#endif /* HAVE_MSGHDR_ACCRIGHTS */
myiovec.iov_base = (void *)&data;
myiovec.iov_len = sizeof(data);
ret = recvmsg( process->obj.fd, &msghdr, 0 );
#ifndef HAVE_MSGHDR_ACCRIGHTS
fd = cmsg.fd;
#endif
if (ret == sizeof(data))
{
struct thread *thread;
if (data.tid) thread = get_thread_from_id( data.tid );
else thread = (struct thread *)grab_object( process->thread_list );
if (!thread || thread->process != process || thread->state == TERMINATED)
{
if (debug_level)
fprintf( stderr, "%04x: *fd* %d <- %d bad thread id\n",
data.tid, data.fd, fd );
close( fd );
}
else
{
if (debug_level)
fprintf( stderr, "%04x: *fd* %d <- %d\n",
thread->id, data.fd, fd );
thread_add_inflight_fd( thread, data.fd, fd );
}
if (thread) release_object( thread );
return 0;
}
if (ret >= 0)
{
if (ret > 0)
fprintf( stderr, "Protocol error: process %p: partial recvmsg %d for fd\n",
process, ret );
kill_process( process, NULL, 1 );
}
else
{
if (errno != EWOULDBLOCK && errno != EAGAIN)
{
fprintf( stderr, "Protocol error: process %p: ", process );
perror( "recvmsg" );
kill_process( process, NULL, 1 );
}
}
return -1;
}
/* send an fd to a client */
int send_client_fd( struct process *process, int fd, obj_handle_t handle )
{
int ret;
if (debug_level)
fprintf( stderr, "%04x: *fd* %p -> %d\n",
current ? current->id : process->id, handle, fd );
#ifdef HAVE_MSGHDR_ACCRIGHTS
msghdr.msg_accrightslen = sizeof(fd);
msghdr.msg_accrights = (void *)&fd;
#else /* HAVE_MSGHDR_ACCRIGHTS */
msghdr.msg_control = &cmsg;
msghdr.msg_controllen = sizeof(cmsg);
cmsg.fd = fd;
#endif /* HAVE_MSGHDR_ACCRIGHTS */
myiovec.iov_base = (void *)&handle;
myiovec.iov_len = sizeof(handle);
ret = sendmsg( process->obj.fd, &msghdr, 0 );
if (ret == sizeof(handle)) return 0;
if (ret >= 0)
{
fprintf( stderr, "Protocol error: process %p: partial sendmsg %d\n", process, ret );
kill_process( process, NULL, 1 );
}
else if (errno == EPIPE)
{
kill_process( process, NULL, 0 );
}
else
{
fprintf( stderr, "Protocol error: process %p: ", process );
perror( "sendmsg" );
kill_process( process, NULL, 1 );
}
return -1;
}
/* get current tick count to return to client */
unsigned int get_tick_count(void)
{
struct timeval t;
gettimeofday( &t, NULL );
return (t.tv_sec * 1000) + (t.tv_usec / 1000) - server_start_ticks;
}
static void master_socket_dump( struct object *obj, int verbose )
{
struct master_socket *sock = (struct master_socket *)obj;
assert( obj->ops == &master_socket_ops );
fprintf( stderr, "Master socket fd=%d\n", sock->obj.fd );
}
/* handle a socket event */
static void master_socket_poll_event( struct object *obj, int event )
{
struct master_socket *sock = (struct master_socket *)obj;
assert( obj->ops == &master_socket_ops );
assert( sock == master_socket ); /* there is only one master socket */
if (event & (POLLERR | POLLHUP))
{
/* this is not supposed to happen */
fprintf( stderr, "wineserver: Error on master socket\n" );
release_object( obj );
}
else if (event & POLLIN)
{
struct sockaddr_un dummy;
int len = sizeof(dummy);
int client = accept( master_socket->obj.fd, (struct sockaddr *) &dummy, &len );
if (client == -1) return;
if (sock->timeout)
{
remove_timeout_user( sock->timeout );
sock->timeout = NULL;
}
fcntl( client, F_SETFL, O_NONBLOCK );
create_process( client );
}
}
/* remove the socket upon exit */
static void socket_cleanup(void)
{
static int do_it_once;
if (!do_it_once++) unlink( server_socket_name );
}
/* create a directory and check its permissions */
static void create_dir( const char *name, struct stat *st )
{
if (lstat( name, st ) == -1)
{
if (errno != ENOENT) fatal_perror( "lstat %s", name );
if (mkdir( name, 0700 ) == -1) fatal_perror( "mkdir %s", name );
if (lstat( name, st ) == -1) fatal_perror( "lstat %s", name );
}
if (!S_ISDIR(st->st_mode)) fatal_error( "%s is not a directory\n", name );
if (st->st_uid != getuid()) fatal_error( "%s is not owned by you\n", name );
if (st->st_mode & 077) fatal_error( "%s must not be accessible by other users\n", name );
}
/* create the server directory and chdir to it */
static void create_server_dir(void)
{
char *p, *server_dir;
struct stat st, st2;
if (!(server_dir = strdup( wine_get_server_dir() ))) fatal_error( "out of memory\n" );
/* first create the base directory if needed */
p = strrchr( server_dir, '/' );
*p = 0;
create_dir( server_dir, &st );
/* now create the server directory */
*p = '/';
create_dir( server_dir, &st );
if (chdir( server_dir ) == -1) fatal_perror( "chdir %s", server_dir );
if (stat( ".", &st2 ) == -1) fatal_perror( "stat %s", server_dir );
if (st.st_dev != st2.st_dev || st.st_ino != st2.st_ino)
fatal_error( "chdir did not end up in %s\n", server_dir );
free( server_dir );
}
/* create the lock file and return its file descriptor */
static int create_server_lock(void)
{
struct stat st;
int fd;
if (lstat( server_lock_name, &st ) == -1)
{
if (errno != ENOENT)
fatal_perror( "lstat %s/%s", wine_get_server_dir(), server_lock_name );
}
else
{
if (!S_ISREG(st.st_mode))
fatal_error( "%s/%s is not a regular file\n", wine_get_server_dir(), server_lock_name );
}
if ((fd = open( server_lock_name, O_CREAT|O_TRUNC|O_WRONLY, 0600 )) == -1)
fatal_perror( "error creating %s/%s", wine_get_server_dir(), server_lock_name );
return fd;
}
/* wait for the server lock */
int wait_for_lock(void)
{
int fd, r;
struct flock fl;
create_server_dir();
fd = create_server_lock();
fl.l_type = F_WRLCK;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 1;
r = fcntl( fd, F_SETLKW, &fl );
close(fd);
return r;
}
/* kill the wine server holding the lock */
int kill_lock_owner( int sig )
{
int fd, i, ret = 0;
pid_t pid = 0;
struct flock fl;
create_server_dir();
fd = create_server_lock();
for (i = 0; i < 10; i++)
{
fl.l_type = F_WRLCK;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 1;
if (fcntl( fd, F_GETLK, &fl ) == -1) goto done;
if (fl.l_type != F_WRLCK) goto done; /* the file is not locked */
if (!pid) /* first time around */
{
if (!(pid = fl.l_pid)) goto done; /* shouldn't happen */
if (sig == -1)
{
if (kill( pid, SIGINT ) == -1) goto done;
kill( pid, SIGCONT );
ret = 1;
}
else /* just send the specified signal and return */
{
ret = (kill( pid, sig ) != -1);
goto done;
}
}
else if (fl.l_pid != pid) goto done; /* no longer the same process */
sleep( 1 );
}
/* waited long enough, now kill it */
kill( pid, SIGKILL );
done:
close( fd );
return ret;
}
/* acquire the main server lock */
static void acquire_lock(void)
{
struct sockaddr_un addr;
struct stat st;
struct flock fl;
int fd, slen, got_lock = 0;
fd = create_server_lock();
fl.l_type = F_WRLCK;
fl.l_whence = SEEK_SET;
fl.l_start = 0;
fl.l_len = 1;
if (fcntl( fd, F_SETLK, &fl ) != -1)
{
/* check for crashed server */
if (stat( server_socket_name, &st ) != -1 && /* there is a leftover socket */
stat( "core", &st ) != -1 && st.st_size) /* and there is a non-empty core file */
{
fprintf( stderr,
"Warning: a previous instance of the wine server seems to have crashed.\n"
"Please run 'gdb %s %s/core',\n"
"type 'backtrace' at the gdb prompt and report the results. Thanks.\n\n",
server_argv0, wine_get_server_dir() );
}
unlink( server_socket_name ); /* we got the lock, we can safely remove the socket */
got_lock = 1;
/* in that case we reuse fd without closing it, this ensures
* that we hold the lock until the process exits */
}
else
{
switch(errno)
{
case ENOLCK:
break;
case EACCES:
/* check whether locks work at all on this file system */
if (fcntl( fd, F_GETLK, &fl ) == -1) break;
/* fall through */
case EAGAIN:
exit(2); /* we didn't get the lock, exit with special status */
default:
fatal_perror( "fcntl %s/%s", wine_get_server_dir(), server_lock_name );
}
/* it seems we can't use locks on this fs, so we will use the socket existence as lock */
close( fd );
}
if ((fd = socket( AF_UNIX, SOCK_STREAM, 0 )) == -1) fatal_perror( "socket" );
addr.sun_family = AF_UNIX;
strcpy( addr.sun_path, server_socket_name );
slen = sizeof(addr) - sizeof(addr.sun_path) + strlen(addr.sun_path) + 1;
#ifdef HAVE_SOCKADDR_SUN_LEN
addr.sun_len = slen;
#endif
if (bind( fd, (struct sockaddr *)&addr, slen ) == -1)
{
if ((errno == EEXIST) || (errno == EADDRINUSE))
{
if (got_lock)
fatal_error( "couldn't bind to the socket even though we hold the lock\n" );
exit(2); /* we didn't get the lock, exit with special status */
}
fatal_perror( "bind" );
}
atexit( socket_cleanup );
chmod( server_socket_name, 0600 ); /* make sure no other user can connect */
if (listen( fd, 5 ) == -1) fatal_perror( "listen" );
if (!(master_socket = alloc_fd_object( &master_socket_ops, &master_socket_fd_ops, fd )))
fatal_error( "out of memory\n" );
master_socket->timeout = NULL;
set_select_events( &master_socket->obj, POLLIN );
}
/* open the master server socket and start waiting for new clients */
void open_master_socket(void)
{
int pid, status, sync_pipe[2];
char dummy;
/* make sure no request is larger than the maximum size */
assert( sizeof(union generic_request) == sizeof(struct request_max_size) );
assert( sizeof(union generic_reply) == sizeof(struct request_max_size) );
create_server_dir();
if (pipe( sync_pipe ) == -1) fatal_perror( "pipe" );
pid = fork();
switch( pid )
{
case 0: /* child */
setsid();
close( sync_pipe[0] );
acquire_lock();
/* signal parent */
write( sync_pipe[1], &dummy, 1 );
close( sync_pipe[1] );
break;
case -1:
fatal_perror( "fork" );
break;
default: /* parent */
close( sync_pipe[1] );
/* wait for child to signal us and then exit */
if (read( sync_pipe[0], &dummy, 1 ) == 1) _exit(0);
/* child terminated, propagate exit status */
wait4( pid, &status, 0, NULL );
if (WIFEXITED(status)) _exit( WEXITSTATUS(status) );
_exit(1);
}
/* setup msghdr structure constant fields */
msghdr.msg_name = NULL;
msghdr.msg_namelen = 0;
msghdr.msg_iov = &myiovec;
msghdr.msg_iovlen = 1;
/* init startup ticks */
server_start_ticks = get_tick_count();
}
/* master socket timer expiration handler */
static void close_socket_timeout( void *arg )
{
master_socket->timeout = NULL;
flush_registry();
/* if a new client is waiting, we keep on running */
if (check_select_events( master_socket->obj.fd, POLLIN )) return;
if (debug_level) fprintf( stderr, "wineserver: exiting (pid=%ld)\n", (long) getpid() );
#ifdef DEBUG_OBJECTS
/* shut down everything properly */
release_object( master_socket );
close_global_hooks();
close_global_handles();
close_registry();
close_atom_table();
#else
exit(0);
#endif
}
/* close the master socket and stop waiting for new clients */
void close_master_socket(void)
{
struct timeval when;
if (master_socket_timeout == -1) return; /* just keep running forever */
if (master_socket_timeout)
{
gettimeofday( &when, 0 );
add_timeout( &when, master_socket_timeout * 1000 );
master_socket->timeout = add_timeout_user( &when, close_socket_timeout, NULL );
}
else close_socket_timeout( NULL ); /* close it right away */
}
/* lock/unlock the master socket to stop accepting new clients */
void lock_master_socket( int locked )
{
set_select_events( &master_socket->obj, locked ? 0 : POLLIN );
}