doio.c

早期freebsd实现

	if (stio->dirp)
	    closedir(stio->dirp);
	if (!(stio->dirp = opendir(str_get(st[sp+1]))))
	    goto nope;
	break;
    case O_READDIR:
	if (gimme == G_ARRAY) {
	    --sp;
	    /*SUPPRESS 560*/
	    while (dp = readdir(stio->dirp)) {
#ifdef DIRNAMLEN
		(void)astore(ary,++sp,
		  str_2mortal(str_make(dp->d_name,dp->d_namlen)));
#else
		(void)astore(ary,++sp,
		  str_2mortal(str_make(dp->d_name,0)));
#endif
	    }
	}
	else {
	    if (!(dp = readdir(stio->dirp)))
		goto nope;
	    st[sp] = str_mortal(&str_undef);
#ifdef DIRNAMLEN
	    str_nset(st[sp], dp->d_name, dp->d_namlen);
#else
	    str_set(st[sp], dp->d_name);
#endif
	}
	break;
#if defined(HAS_TELLDIR) || defined(telldir)
    case O_TELLDIR: {
#ifndef telldir
	    long telldir();
#endif
	    st[sp] = str_mortal(&str_undef);
	    str_numset(st[sp], (double)telldir(stio->dirp));
	    break;
	}
#endif
#if defined(HAS_SEEKDIR) || defined(seekdir)
    case O_SEEKDIR:
	st[sp] = str_mortal(&str_undef);
	along = (long)str_gnum(st[sp+1]);
	(void)seekdir(stio->dirp,along);
	break;
#endif
#if defined(HAS_REWINDDIR) || defined(rewinddir)
    case O_REWINDDIR:
	st[sp] = str_mortal(&str_undef);
	(void)rewinddir(stio->dirp);
	break;
#endif
    case O_CLOSEDIR:
	st[sp] = str_mortal(&str_undef);
	(void)closedir(stio->dirp);
	stio->dirp = 0;
	break;
    default:
	goto phooey;
    }
    return sp;

nope:
    st[sp] = &str_undef;
    if (!errno)
	errno = EBADF;
    return sp;

#endif
phooey:
    fatal("Unimplemented directory operation");
}

int
apply(type,arglast)
int type;
int *arglast;
{
    register STR **st = stack->ary_array;
    register int sp = arglast[1];
    register int items = arglast[2] - sp;
    register int val;
    register int val2;
    register int tot = 0;
    char *s;

#ifdef TAINT
    for (st += ++sp; items--; st++)
	tainted |= (*st)->str_tainted;
    st = stack->ary_array;
    sp = arglast[1];
    items = arglast[2] - sp;
#endif
    switch (type) {
    case O_CHMOD:
#ifdef TAINT
	taintproper("Insecure dependency in chmod");
#endif
	if (--items > 0) {
	    tot = items;
	    val = (int)str_gnum(st[++sp]);
	    while (items--) {
		if (chmod(str_get(st[++sp]),val))
		    tot--;
	    }
	}
	break;
#ifdef HAS_CHOWN
    case O_CHOWN:
#ifdef TAINT
	taintproper("Insecure dependency in chown");
#endif
	if (items > 2) {
	    items -= 2;
	    tot = items;
	    val = (int)str_gnum(st[++sp]);
	    val2 = (int)str_gnum(st[++sp]);
	    while (items--) {
		if (chown(str_get(st[++sp]),val,val2))
		    tot--;
	    }
	}
	break;
#endif
#ifdef HAS_KILL
    case O_KILL:
#ifdef TAINT
	taintproper("Insecure dependency in kill");
#endif
	if (--items > 0) {
	    tot = items;
	    s = str_get(st[++sp]);
	    if (isUPPER(*s)) {
		if (*s == 'S' && s[1] == 'I' && s[2] == 'G')
		    s += 3;
		if (!(val = whichsig(s)))
		    fatal("Unrecognized signal name \"%s\"",s);
	    }
	    else
		val = (int)str_gnum(st[sp]);
	    if (val < 0) {
		val = -val;
		while (items--) {
		    int proc = (int)str_gnum(st[++sp]);
#ifdef HAS_KILLPG
		    if (killpg(proc,val))	/* BSD */
#else
		    if (kill(-proc,val))	/* SYSV */
#endif
			tot--;
		}
	    }
	    else {
		while (items--) {
		    if (kill((int)(str_gnum(st[++sp])),val))
			tot--;
		}
	    }
	}
	break;
#endif
    case O_UNLINK:
#ifdef TAINT
	taintproper("Insecure dependency in unlink");
#endif
	tot = items;
	while (items--) {
	    s = str_get(st[++sp]);
	    if (euid || unsafe) {
		if (UNLINK(s))
		    tot--;
	    }
	    else {	/* don't let root wipe out directories without -U */
#ifdef HAS_LSTAT
		if (lstat(s,&statbuf) < 0 || S_ISDIR(statbuf.st_mode))
#else
		if (stat(s,&statbuf) < 0 || S_ISDIR(statbuf.st_mode))
#endif
		    tot--;
		else {
		    if (UNLINK(s))
			tot--;
		}
	    }
	}
	break;
    case O_UTIME:
#ifdef TAINT
	taintproper("Insecure dependency in utime");
#endif
	if (items > 2) {
#ifdef I_UTIME
	    struct utimbuf utbuf;
#else
	    struct {
		long    actime;
		long	modtime;
	    } utbuf;
#endif

	    Zero(&utbuf, sizeof utbuf, char);
	    utbuf.actime = (long)str_gnum(st[++sp]);    /* time accessed */
	    utbuf.modtime = (long)str_gnum(st[++sp]);    /* time modified */
	    items -= 2;
#ifndef lint
	    tot = items;
	    while (items--) {
		if (utime(str_get(st[++sp]),&utbuf))
		    tot--;
	    }
#endif
	}
	else
	    items = 0;
	break;
    }
    return tot;
}

/* Do the permissions allow some operation?  Assumes statcache already set. */

int
cando(bit, effective, statbufp)
int bit;
int effective;
register struct stat *statbufp;
{
#ifdef DOSISH
    /* [Comments and code from Len Reed]
     * MS-DOS "user" is similar to UNIX's "superuser," but can't write
     * to write-protected files.  The execute permission bit is set
     * by the Miscrosoft C library stat() function for the following:
     *		.exe files
     *		.com files
     *		.bat files
     *		directories
     * All files and directories are readable.
     * Directories and special files, e.g. "CON", cannot be
     * write-protected.
     * [Comment by Tom Dinger -- a directory can have the write-protect
     *		bit set in the file system, but DOS permits changes to
     *		the directory anyway.  In addition, all bets are off
     *		here for networked software, such as Novell and
     *		Sun's PC-NFS.]
     */

     /* Atari stat() does pretty much the same thing. we set x_bit_set_in_stat
      * too so it will actually look into the files for magic numbers
      */
     return (bit & statbufp->st_mode) ? TRUE : FALSE;

#else /* ! MSDOS */
    if ((effective ? euid : uid) == 0) {	/* root is special */
	if (bit == S_IXUSR) {
	    if (statbufp->st_mode & 0111 || S_ISDIR(statbufp->st_mode))
		return TRUE;
	}
	else
	    return TRUE;		/* root reads and writes anything */
	return FALSE;
    }
    if (statbufp->st_uid == (effective ? euid : uid) ) {
	if (statbufp->st_mode & bit)
	    return TRUE;	/* ok as "user" */
    }
    else if (ingroup((int)statbufp->st_gid,effective)) {
	if (statbufp->st_mode & bit >> 3)
	    return TRUE;	/* ok as "group" */
    }
    else if (statbufp->st_mode & bit >> 6)
	return TRUE;	/* ok as "other" */
    return FALSE;
#endif /* ! MSDOS */
}

int
ingroup(testgid,effective)
int testgid;
int effective;
{
    if (testgid == (effective ? egid : gid))
	return TRUE;
#ifdef HAS_GETGROUPS
#ifndef NGROUPS
#define NGROUPS 32
#endif
    {
	GROUPSTYPE gary[NGROUPS];
	int anum;

	anum = getgroups(NGROUPS,gary);
	while (--anum >= 0)
	    if (gary[anum] == testgid)
		return TRUE;
    }
#endif
    return FALSE;
}

#if defined(HAS_MSG) || defined(HAS_SEM) || defined(HAS_SHM)

int
do_ipcget(optype, arglast)
int optype;
int *arglast;
{
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    key_t key;
    int n, flags;

    key = (key_t)str_gnum(st[++sp]);
    n = (optype == O_MSGGET) ? 0 : (int)str_gnum(st[++sp]);
    flags = (int)str_gnum(st[++sp]);
    errno = 0;
    switch (optype)
    {
#ifdef HAS_MSG
    case O_MSGGET:
	return msgget(key, flags);
#endif
#ifdef HAS_SEM
    case O_SEMGET:
	return semget(key, n, flags);
#endif
#ifdef HAS_SHM
    case O_SHMGET:
	return shmget(key, n, flags);
#endif
#if !defined(HAS_MSG) || !defined(HAS_SEM) || !defined(HAS_SHM)
    default:
	fatal("%s not implemented", opname[optype]);
#endif
    }
    return -1;			/* should never happen */
}

int
do_ipcctl(optype, arglast)
int optype;
int *arglast;
{
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    STR *astr;
    char *a;
    int id, n, cmd, infosize, getinfo, ret;

    id = (int)str_gnum(st[++sp]);
    n = (optype == O_SEMCTL) ? (int)str_gnum(st[++sp]) : 0;
    cmd = (int)str_gnum(st[++sp]);
    astr = st[++sp];

    infosize = 0;
    getinfo = (cmd == IPC_STAT);

    switch (optype)
    {
#ifdef HAS_MSG
    case O_MSGCTL:
	if (cmd == IPC_STAT || cmd == IPC_SET)
	    infosize = sizeof(struct msqid_ds);
	break;
#endif
#ifdef HAS_SHM
    case O_SHMCTL:
	if (cmd == IPC_STAT || cmd == IPC_SET)
	    infosize = sizeof(struct shmid_ds);
	break;
#endif
#ifdef HAS_SEM
    case O_SEMCTL:
	if (cmd == IPC_STAT || cmd == IPC_SET)
	    infosize = sizeof(struct semid_ds);
	else if (cmd == GETALL || cmd == SETALL)
	{
	    struct semid_ds semds;
	    if (semctl(id, 0, IPC_STAT, &semds) == -1)
		return -1;
	    getinfo = (cmd == GETALL);
	    infosize = semds.sem_nsems * sizeof(short);
		/* "short" is technically wrong but much more portable
		   than guessing about u_?short(_t)? */
	}
	break;
#endif
#if !defined(HAS_MSG) || !defined(HAS_SEM) || !defined(HAS_SHM)
    default:
	fatal("%s not implemented", opname[optype]);
#endif
    }

    if (infosize)
    {
	if (getinfo)
	{
	    STR_GROW(astr, infosize+1);
	    a = str_get(astr);
	}
	else
	{
	    a = str_get(astr);
	    if (astr->str_cur != infosize)
	    {
		errno = EINVAL;
		return -1;
	    }
	}
    }
    else
    {
	int i = (int)str_gnum(astr);
	a = (char *)i;		/* ouch */
    }
    errno = 0;
    switch (optype)
    {
#ifdef HAS_MSG
    case O_MSGCTL:
	ret = msgctl(id, cmd, (struct msqid_ds *)a);
	break;
#endif
#ifdef HAS_SEM
    case O_SEMCTL:
	ret = semctl(id, n, cmd, a);
	break;
#endif
#ifdef HAS_SHM
    case O_SHMCTL:
	ret = shmctl(id, cmd, (struct shmid_ds *)a);
	break;
#endif
    }
    if (getinfo && ret >= 0) {
	astr->str_cur = infosize;
	astr->str_ptr[infosize] = '\0';
    }
    return ret;
}

int
do_msgsnd(arglast)
int *arglast;
{
#ifdef HAS_MSG
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    STR *mstr;
    char *mbuf;
    int id, msize, flags;

    id = (int)str_gnum(st[++sp]);
    mstr = st[++sp];
    flags = (int)str_gnum(st[++sp]);
    mbuf = str_get(mstr);
    if ((msize = mstr->str_cur - sizeof(long)) < 0) {
	errno = EINVAL;
	return -1;
    }
    errno = 0;
    return msgsnd(id, (struct msgbuf *)mbuf, msize, flags);
#else
    fatal("msgsnd not implemented");
#endif
}

int
do_msgrcv(arglast)
int *arglast;
{
#ifdef HAS_MSG
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    STR *mstr;
    char *mbuf;
    long mtype;
    int id, msize, flags, ret;

    id = (int)str_gnum(st[++sp]);
    mstr = st[++sp];
    msize = (int)str_gnum(st[++sp]);
    mtype = (long)str_gnum(st[++sp]);
    flags = (int)str_gnum(st[++sp]);
    mbuf = str_get(mstr);
    if (mstr->str_cur < sizeof(long)+msize+1) {
	STR_GROW(mstr, sizeof(long)+msize+1);
	mbuf = str_get(mstr);
    }
    errno = 0;
    ret = msgrcv(id, (struct msgbuf *)mbuf, msize, mtype, flags);
    if (ret >= 0) {
	mstr->str_cur = sizeof(long)+ret;
	mstr->str_ptr[sizeof(long)+ret] = '\0';
    }
    return ret;
#else
    fatal("msgrcv not implemented");
#endif
}

int
do_semop(arglast)
int *arglast;
{
#ifdef HAS_SEM
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    STR *opstr;
    char *opbuf;
    int id, opsize;

    id = (int)str_gnum(st[++sp]);
    opstr = st[++sp];
    opbuf = str_get(opstr);
    opsize = opstr->str_cur;
    if (opsize < sizeof(struct sembuf)
	|| (opsize % sizeof(struct sembuf)) != 0) {
	errno = EINVAL;
	return -1;
    }
    errno = 0;
    return semop(id, (struct sembuf *)opbuf, opsize/sizeof(struct sembuf));
#else
    fatal("semop not implemented");
#endif
}

int
do_shmio(optype, arglast)
int optype;
int *arglast;
{
#ifdef HAS_SHM
    register STR **st = stack->ary_array;
    register int sp = arglast[0];
    STR *mstr;
    char *mbuf, *shm;
    int id, mpos, msize;
    struct shmid_ds shmds;
#ifndef VOIDSHMAT
    extern char *shmat();
#endif

    id = (int)str_gnum(st[++sp]);
    mstr = st[++sp];
    mpos = (int)str_gnum(st[++sp]);
    msize = (int)str_gnum(st[++sp]);
    errno = 0;
    if (shmctl(id, IPC_STAT, &shmds) == -1)
	return -1;
    if (mpos < 0 || msize < 0 || mpos + msize > shmds.shm_segsz) {
	errno = EFAULT;		/* can't do as caller requested */
	return -1;
    }
    shm = (char*)shmat(id, (char*)NULL, (optype == O_SHMREAD) ? SHM_RDONLY : 0);
    if (shm == (char *)-1)	/* I hate System V IPC, I really do */
	return -1;
    mbuf = str_get(mstr);
    if (optype == O_SHMREAD) {
	if (mstr->str_cur < msize) {
	    STR_GROW(mstr, msize+1);
	    mbuf = str_get(mstr);
	}
	Copy(shm + mpos, mbuf, msize, char);
	mstr->str_cur = msize;
	mstr->str_ptr[msize] = '\0';
    }
    else {
	int n;

	if ((n = mstr->str_cur) > msize)
	    n = msize;
	Copy(mbuf, shm + mpos, n, char);
	if (n < msize)
	    memzero(shm + mpos + n, msize - n);
    }
    return shmdt(shm);
#else
    fatal("shm I/O not implemented");
#endif
}

#endif /* SYSV IPC */