kern_sysctl.c

来自「eCos操作系统源码」· C语言 代码 · 共 1,055 行 · 第 1/2 页

			break;
		}
		lsp = lsp2;
	}
	return (SYSCTL_OUT(req, "", 1));
}

SYSCTL_NODE(_sysctl, 1, name, CTLFLAG_RD, sysctl_sysctl_name, "");

static int
sysctl_sysctl_next_ls(struct sysctl_oid_list *lsp, int *name, u_int namelen, 
	int *next, int *len, int level, struct sysctl_oid **oidpp)
{
	struct sysctl_oid *oidp;

	*len = level;
	SLIST_FOREACH(oidp, lsp, oid_link) {
		*next = oidp->oid_number;
		*oidpp = oidp;

		if (!namelen) {
			if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE) 
				return 0;
			if (oidp->oid_handler) 
				/* We really should call the handler here...*/
				return 0;
			lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
			if (!sysctl_sysctl_next_ls(lsp, 0, 0, next+1, 
				len, level+1, oidpp))
				return 0;
			goto emptynode;
		}

		if (oidp->oid_number < *name)
			continue;

		if (oidp->oid_number > *name) {
			if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
				return 0;
			if (oidp->oid_handler)
				return 0;
			lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
			if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, 
				next+1, len, level+1, oidpp))
				return (0);
			goto next;
		}
		if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
			continue;

		if (oidp->oid_handler)
			continue;

		lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
		if (!sysctl_sysctl_next_ls(lsp, name+1, namelen-1, next+1, 
			len, level+1, oidpp))
			return (0);
	next:
		namelen = 1;
        emptynode:
		*len = level;
	}
	return 1;
}

static int
sysctl_sysctl_next(SYSCTL_HANDLER_ARGS)
{
	int *name = (int *) arg1;
	u_int namelen = arg2;
	int i, j, error;
	struct sysctl_oid *oid;
	struct sysctl_oid_list *lsp = &sysctl__children;
	int newoid[CTL_MAXNAME];

	i = sysctl_sysctl_next_ls(lsp, name, namelen, newoid, &j, 1, &oid);
	if (i)
		return ENOENT;
	error = SYSCTL_OUT(req, newoid, j * sizeof (int));
	return (error);
}

SYSCTL_NODE(_sysctl, 2, next, CTLFLAG_RD, sysctl_sysctl_next, "");

static int
name2oid (char *name, int *oid, int *len, struct sysctl_oid **oidpp)
{
	int i;
	struct sysctl_oid *oidp;
	struct sysctl_oid_list *lsp = &sysctl__children;
	char *p;

	if (!*name)
		return ENOENT;

	p = name + strlen(name) - 1 ;
	if (*p == '.')
		*p = '\0';

	*len = 0;

	for (p = name; *p && *p != '.'; p++) 
		;
	i = *p;
	if (i == '.')
		*p = '\0';

	oidp = SLIST_FIRST(lsp);

	while (oidp && *len < CTL_MAXNAME) {
		if (strcmp(name, oidp->oid_name)) {
			oidp = SLIST_NEXT(oidp, oid_link);
			continue;
		}
		*oid++ = oidp->oid_number;
		(*len)++;

		if (!i) {
			if (oidpp)
				*oidpp = oidp;
			return (0);
		}

		if ((oidp->oid_kind & CTLTYPE) != CTLTYPE_NODE)
			break;

		if (oidp->oid_handler)
			break;

		lsp = (struct sysctl_oid_list *)oidp->oid_arg1;
		oidp = SLIST_FIRST(lsp);
		name = p+1;
		for (p = name; *p && *p != '.'; p++) 
				;
		i = *p;
		if (i == '.')
			*p = '\0';
	}
	return ENOENT;
}

static int
sysctl_sysctl_name2oid(SYSCTL_HANDLER_ARGS)
{
	char *p;
	int error, oid[CTL_MAXNAME], len;
	struct sysctl_oid *op = 0;

	if (!req->newlen) 
		return ENOENT;
	if (req->newlen >= _POSIX_PATH_MAX)	/* XXX arbitrary, undocumented */
		return (ENAMETOOLONG);

	p = malloc(req->newlen+1, M_SYSCTL, M_WAITOK);

	error = SYSCTL_IN(req, p, req->newlen);
	if (error) {
		free(p, M_SYSCTL);
		return (error);
	}

	p [req->newlen] = '\0';

	error = name2oid(p, oid, &len, &op);

	free(p, M_SYSCTL);

	if (error)
		return (error);

	error = SYSCTL_OUT(req, oid, len * sizeof *oid);
	return (error);
}

SYSCTL_PROC(_sysctl, 3, name2oid, CTLFLAG_RW|CTLFLAG_ANYBODY, 0, 0, 
	sysctl_sysctl_name2oid, "I", "");

static int
sysctl_sysctl_oidfmt(SYSCTL_HANDLER_ARGS)
{
	struct sysctl_oid *oid;
	int error;

	error = sysctl_find_oid(arg1, arg2, &oid, NULL, req);
	if (error)
		return (error);

	if (!oid->oid_fmt)
		return (ENOENT);
	error = SYSCTL_OUT(req, &oid->oid_kind, sizeof(oid->oid_kind));
	if (error)
		return (error);
	error = SYSCTL_OUT(req, oid->oid_fmt, strlen(oid->oid_fmt) + 1);
	return (error);
}


SYSCTL_NODE(_sysctl, 4, oidfmt, CTLFLAG_RD, sysctl_sysctl_oidfmt, "");

/*
 * Default "handler" functions.
 */

/*
 * Handle an int, signed or unsigned.
 * Two cases:
 *     a variable:  point arg1 at it.
 *     a constant:  pass it in arg2.
 */

int
sysctl_handle_int(SYSCTL_HANDLER_ARGS)
{
	int error = 0;

	if (arg1)
		error = SYSCTL_OUT(req, arg1, sizeof(int));
	else
		error = SYSCTL_OUT(req, &arg2, sizeof(int));

	if (error || !req->newptr)
		return (error);

	if (!arg1)
		error = EPERM;
	else
		error = SYSCTL_IN(req, arg1, sizeof(int));
	return (error);
}

/*
 * Handle a long, signed or unsigned.  arg1 points to it.
 */

int
sysctl_handle_long(SYSCTL_HANDLER_ARGS)
{
	int error = 0;

	if (!arg1)
		return (EINVAL);
	error = SYSCTL_OUT(req, arg1, sizeof(long));

	if (error || !req->newptr)
		return (error);

	error = SYSCTL_IN(req, arg1, sizeof(long));
	return (error);
}

/*
 * Handle our generic '\0' terminated 'C' string.
 * Two cases:
 * 	a variable string:  point arg1 at it, arg2 is max length.
 * 	a constant string:  point arg1 at it, arg2 is zero.
 */

int
sysctl_handle_string(SYSCTL_HANDLER_ARGS)
{
	int error=0;

	error = SYSCTL_OUT(req, arg1, strlen((char *)arg1)+1);

	if (error || !req->newptr)
		return (error);

	if ((req->newlen - req->newidx) >= arg2) {
		error = EINVAL;
	} else {
		arg2 = (req->newlen - req->newidx);
		error = SYSCTL_IN(req, arg1, arg2);
		((char *)arg1)[arg2] = '\0';
	}

	return (error);
}

/*
 * Handle any kind of opaque data.
 * arg1 points to it, arg2 is the size.
 */

int
sysctl_handle_opaque(SYSCTL_HANDLER_ARGS)
{
	int error;

	error = SYSCTL_OUT(req, arg1, arg2);

	if (error || !req->newptr)
		return (error);

	error = SYSCTL_IN(req, arg1, arg2);

	return (error);
}

/*
 * Transfer function to/from user space.
 */
static int
sysctl_old_user(struct sysctl_req *req, const void *p, size_t l)
{
	int error = 0;
	size_t i = 0;

	if (req->oldptr) {
		i = l;
		if (i > req->oldlen - req->oldidx)
			i = req->oldlen - req->oldidx;
		if (i > 0)
			error = copyout(p, (char *)req->oldptr + req->oldidx,
					i);
	}
	req->oldidx += l;
	if (error)
		return (error);
	if (req->oldptr && i < l)
		return (ENOMEM);
	return (0);
}

static int
sysctl_new_user(struct sysctl_req *req, void *p, size_t l)
{
	int error;

	if (!req->newptr)
		return 0;
	if (req->newlen - req->newidx < l)
		return (EINVAL);
	error = copyin((char *)req->newptr + req->newidx, p, l);
	req->newidx += l;
	return (error);
}

int
sysctl_find_oid(int *name, u_int namelen, struct sysctl_oid **noid,
    int *nindx, struct sysctl_req *req)
{
	struct sysctl_oid *oid;
	int indx;

	oid = SLIST_FIRST(&sysctl__children);
	indx = 0;
	while (oid && indx < CTL_MAXNAME) {
		if (oid->oid_number == name[indx]) {
			indx++;
			if (oid->oid_kind & CTLFLAG_NOLOCK)
				req->lock = 0;
			if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
				if (oid->oid_handler != NULL ||
				    indx == namelen) {
					*noid = oid;
					if (nindx != NULL)
						*nindx = indx;
					return (0);
				}
				oid = SLIST_FIRST(
				    (struct sysctl_oid_list *)oid->oid_arg1);
			} else if (indx == namelen) {
				*noid = oid;
				if (nindx != NULL)
					*nindx = indx;
				return (0);
			} else {
				return (ENOTDIR);
			}
		} else {
			oid = SLIST_NEXT(oid, oid_link);
		}
	}
	return (ENOENT);
}

/*
 * Traverse our tree, and find the right node, execute whatever it points
 * to, and return the resulting error code.
 */

int
sysctl_root(SYSCTL_HANDLER_ARGS)
{
	struct sysctl_oid *oid;
	int error, indx;

	error = sysctl_find_oid(arg1, arg2, &oid, &indx, req);
	if (error)
		return (error);

	if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE) {
		/*
		 * You can't call a sysctl when it's a node, but has
		 * no handler.  Inform the user that it's a node.
		 * The indx may or may not be the same as namelen.
		 */
		if (oid->oid_handler == NULL)
			return (EISDIR);
	}

	/* If writing isn't allowed */
	if (req->newptr && (!(oid->oid_kind & CTLFLAG_WR)))
		return (EPERM);

	if (!oid->oid_handler)
		return EINVAL;

	if ((oid->oid_kind & CTLTYPE) == CTLTYPE_NODE)
		error = oid->oid_handler(oid, (int *)arg1 + indx, arg2 - indx,
		    req);
	else
		error = oid->oid_handler(oid, oid->oid_arg1, oid->oid_arg2,
		    req);
	return (error);
}

#ifndef _SYS_SYSPROTO_H_
struct sysctl_args {
	int	*name;
	u_int	namelen;
	void	*old;
	size_t	*oldlenp;
	void	*new;
	size_t	newlen;
};
#endif

int
sysctl(int *name, u_int namelen, void *old, size_t *oldlenp, void *new, size_t newlen)
{
	int error = 0;
	struct sysctl_req req, req2;
        int retval;

        if (!mutex_init) {
          cyg_mutex_init(&mutex);
        }

	bzero(&req, sizeof req);

	if (oldlenp) {
                req.oldlen = *oldlenp;
	}

	if (old) {
		req.oldptr= old;
	}

	if (new != NULL) {
		req.newlen = newlen;
		req.newptr = new;
	}

	req.oldfunc = sysctl_old_user;
	req.newfunc = sysctl_new_user;
	req.lock = 1;

        cyg_mutex_lock(&mutex);
        
	do {
	    req2 = req;
	    error = sysctl_root(0, name, namelen, &req2);
	} while (error == EAGAIN);

	req = req2;

        cyg_mutex_unlock(&mutex);

	if (error && error != ENOMEM) {
          errno = error;
          return -1;
        }

        if (oldlenp) {
          *oldlenp = req.oldidx;
        }
        
        if (req.oldptr && req.oldidx > req.oldlen)
          retval = req.oldlen;
        else
          retval = req.oldidx;
        
	return retval;
}

/* name2oid modify the name passed to it. So we have to make a local copy */
int sysctlnametomib(const char * name, int *mibp, size_t *sizep) 
{
  int error = 0, oid[CTL_MAXNAME], len;
  char *namep;

  len = strlen(name);
  namep = malloc(len+1,M_SYSCTLOID, M_WAITOK);
  strcpy(namep, name);

  error = name2oid(namep, oid, &len, NULL);
  free(namep,M_SYSCTLOID);

  if (len * sizeof(int) > *sizep) {
    error = ENOMEM;
  }
  
  if (error) {
    errno = error;
    return -1;
  }
  
  memcpy(mibp, oid, len * sizeof(int));
  *sizep = len;
  return 0;
}
  
int sysctlbyname(const char * name,void *oldp, size_t *oldlenp, 
                 void *newp, size_t newlen) 
{
  int oid[CTL_MAXNAME];
  size_t sizep = sizeof(oid);

  if (sysctlnametomib(name, oid, &sizep) != -1) {
    return (sysctl(oid, sizep, oldp, oldlenp, newp, newlen));
  }
  
  return -1;
}