Sweden-Number/ipc/shm_main_blk.c

272 lines
6.7 KiB
C

/***************************************************************************
* Copyright 1995, Technion, Israel Institute of Technology
* Electrical Eng, Software Lab.
* Author: Michael Veksler.
***************************************************************************
* File: shm_main_blk.c
* Purpose: Main Wine's shared memory block
***************************************************************************
*/
#ifdef CONFIG_IPC
#include <sys/types.h>
#include <sys/sem.h>
#include <time.h>
#include <assert.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include "debugtools.h"
#include "shm_fragment.h"
#include "shm_block.h"
#include "shm_main_blk.h"
#include "shm_semaph.h"
DEFAULT_DEBUG_CHANNEL(shm)
#define WineKey ( 'W'+((int)'i'<<8)+((int)'n'<<16)+((int)'e'<<24) )
#define SHM_KEY_RANGE 8
/* main block (set during initialization) */
struct shm_main_block *main_block=NULL;
static char *shm_header="Wine - Windows emulator DDE mechanism";
static int main_shm_id;
static void shm_main_refresh();
/* for debugging only */
static void print_perm(struct ipc_perm *perm)
{
printf("Permission:\n");
/* FIXME: not portable
printf("\tKey=%d, mode=%03o, sequence #=%d\n",
(int)perm->key,perm->mode, perm->seq);
*/
printf("\towner: uid=%d, gid=%d ;" ,perm->uid, perm->gid);
printf(" creator: uid=%d, gid=%d\n",perm->cuid,perm->cgid);
}
/* for debugging only */
/* print_shm_info: print shared memory descriptor info */
static void print_shm_info(int shm_id)
{
struct shmid_ds ds;
shmctl(shm_id, IPC_STAT, &ds );
printf("shm_id=%d, Size=0x%08x , Number of attaches=%d\n",
shm_id, ds.shm_segsz, (int)ds.shm_nattch);
if (ds.shm_atime)
printf("Last attach=%s",ctime(&ds.shm_atime));
if (ds.shm_dtime)
printf("Last detach=%s",ctime(&ds.shm_dtime));
printf("Last change=%s",ctime(&ds.shm_ctime));
printf("pid: creator=%d, last operator=%d\n",
(int)ds.shm_cpid,(int)ds.shm_lpid);
print_perm( &ds.shm_perm);
}
int proc_exist(pid_t pid)
{
if ( kill(pid,0) == 0) /* dummy signal to test existence */
return 1;
else if (errno==ESRCH) /* "no such process" */
return 0;
else
return 1;
}
/* setup a new main shm block (only construct a shm block object). */
static void shm_setup_main_block()
{
TRACE("creating data structure\n");
main_block->build_lock=1;
strcpy(main_block->magic, shm_header);
shm_setup_block(&main_block->block,sizeof(*main_block),SHM_MINBLOCK);
dde_proc_init(main_block->proc);
ATOM_GlobalInit();
shm_sem_init(&main_block->sem);
/* main block set and data structure is stable now */
main_block->build_lock=0;
}
/* Delete everything related to main_block */
void shm_delete_all(int shmid)
{
int proc_idx;
if (shmid == -1)
shmid= main_shm_id;
shmctl( shmid, IPC_RMID, NULL);
for (proc_idx= 0 ; proc_idx < DDE_PROCS ; proc_idx++)
dde_proc_done( &main_block->proc[proc_idx] );
shm_sem_done(&main_block->sem);
shmdt( (void *) main_block);
main_block= NULL;
}
int DDE_no_of_attached()
{
struct shmid_ds shm_info;
if (shmctl(main_shm_id, IPC_STAT, &shm_info) == -1)
return -1;
return shm_info.shm_nattch;
}
/*
** Test if shm_id is MainBlock and attach it (if it is),
** Return 1 if ok, 0 otherwise.
*/
static int attach_MainBlock(int shm_id)
{
struct shmid_ds shm_info;
if (shmctl(shm_id, IPC_STAT, &shm_info) == -1)
return 0;
/* Make sure we don't work on somebody else's block */
if (shm_info.shm_perm.cuid != getuid()) { /* creator is not me */
WARN("Creator is not me!\n");
return 0;
}
TRACE("shared memory exist, attaching anywhere\n");
main_block=(struct shm_main_block *)shmat(shm_id, 0, 0);
if ( (int)main_block==-1) {
WARN("Attach failed\n");
return 0;
}
if (strcmp(main_block->magic, shm_header) != 0) {
TRACE("Detaching, wrong magic\n");
shmdt((void *)main_block);
return 0;
}
if (TRACE_ON(shm))
print_shm_info(shm_id);
/* Is it an old unused block ? */
if (shm_info.shm_nattch == 0) {
TRACE("No attaches, deleting old data\n");
shm_delete_all(shm_id);
return 0;
}
/* Wait for data structure to stabilize */
while (main_block->build_lock)
usleep(10000);
main_shm_id= shm_id;
shm_main_refresh();
return 1;
}
/* (Function used by the constructor)
* Try to get existing shared memory with key="Wine", size=SHM_MINBLOCK
* complete user permission.
* If such block is found - return true (1), else return false (0)
*/
static int shm_locate_MainBlock(key_t shm_key)
{
int shm_id; /* Descriptor to this shared memory */
int i;
TRACE("trying to attach, key=0x%x\n",
shm_key);
for (i=0 ; i < SHM_KEY_RANGE ; i++) {
TRACE("iteration=%d\n", i);
shm_id= shmget ( shm_key+i, SHM_MINBLOCK ,0700);
if (shm_id != -1) {
if ( attach_MainBlock(shm_id) ) {
return 1; /* success! */
}
} else {
switch(errno) {
#ifdef EIDRM
case EIDRM: /* segment destroyed */
#endif
case EACCES: /* no user permision */
break;
case ENOMEM: /* no free memory */
case ENOENT: /* this key does not exist */
default :
WARN("shmget failed, errno=%d, %s\n",
errno, strerror(errno) );
return 0; /* Failed */
}
} /* if .. else */
} /* for */
return 0;
}
/* (Function used by the constructor)
* Try to allocate new shared memory with key="Wine", size=SHM_MINBLOCK
* with complete user permission.
* If allocation succeeds - return true (1), else return false (0)
*/
static int shm_create_MainBlock(key_t MainShmKey)
{
int shm_id;
int flags= 0700 | IPC_CREAT | IPC_EXCL;
int i;
TRACE("creating shared memory\n");
/* try to allocate shared memory with key="Wine", size=SHM_MINBLOCK, */
/* complete user permission */
for (i=0 ; i < SHM_KEY_RANGE ; i++) {
shm_id= shmget ( (key_t) MainShmKey, SHM_MINBLOCK, flags);
if (shm_id != -1)
break;
}
if (shm_id == -1) {
WARN("failed to create shared memory\n");
return 0;
}
TRACE("shared memory created, attaching\n");
main_block=(struct shm_main_block*) shmat(shm_id, 0,0);
if (TRACE_ON(shm))
print_shm_info(shm_id);
main_shm_id= shm_id;
shm_setup_main_block();
dde_wnd_setup();
return 1;
}
/* link to the dde shared memory block */
/* RETURN: 0 on success, non zero on failure */
int shm_init(void)
{
if ( !shm_locate_MainBlock(WineKey)
&& !shm_create_MainBlock(WineKey)) {
ERR("Failed to init main shm block\n");
exit(1);
}
dde_proc_add(main_block->proc);
return 0;
}
static void shm_main_refresh()
{
int proc_idx;
for (proc_idx= 0 ; proc_idx < DDE_PROCS ; proc_idx++)
dde_proc_refresh( &main_block->proc[proc_idx] );
}
#endif /* CONFIG_IPC */