/* * This file implement the Wireless Extensions priv API. * * Authors : Jean Tourrilhes - HPL - <jt@hpl.hp.com> * Copyright (c) 1997-2007 Jean Tourrilhes, All Rights Reserved. * Copyright 2009 Johannes Berg <johannes@sipsolutions.net> * * (As all part of the Linux kernel, this file is GPL) */ #include <linux/wireless.h> #include <linux/netdevice.h> #include <net/iw_handler.h> #include <net/wext.h> int iw_handler_get_private(struct net_device * dev, struct iw_request_info * info, union iwreq_data * wrqu, char * extra) { /* Check if the driver has something to export */ if ((dev->wireless_handlers->num_private_args == 0) || (dev->wireless_handlers->private_args == NULL)) return -EOPNOTSUPP; /* Check if there is enough buffer up there */ if (wrqu->data.length < dev->wireless_handlers->num_private_args) { /* User space can't know in advance how large the buffer * needs to be. Give it a hint, so that we can support * any size buffer we want somewhat efficiently... */ wrqu->data.length = dev->wireless_handlers->num_private_args; return -E2BIG; } /* Set the number of available ioctls. */ wrqu->data.length = dev->wireless_handlers->num_private_args; /* Copy structure to the user buffer. */ memcpy(extra, dev->wireless_handlers->private_args, sizeof(struct iw_priv_args) * wrqu->data.length); return 0; } /* Size (in bytes) of the various private data types */ static const char iw_priv_type_size[] = { 0, /* IW_PRIV_TYPE_NONE */ 1, /* IW_PRIV_TYPE_BYTE */ 1, /* IW_PRIV_TYPE_CHAR */ 0, /* Not defined */ sizeof(__u32), /* IW_PRIV_TYPE_INT */ sizeof(struct iw_freq), /* IW_PRIV_TYPE_FLOAT */ sizeof(struct sockaddr), /* IW_PRIV_TYPE_ADDR */ 0, /* Not defined */ }; static int get_priv_size(__u16 args) { int num = args & IW_PRIV_SIZE_MASK; int type = (args & IW_PRIV_TYPE_MASK) >> 12; return num * iw_priv_type_size[type]; } static int adjust_priv_size(__u16 args, struct iw_point *iwp) { int num = iwp->length; int max = args & IW_PRIV_SIZE_MASK; int type = (args & IW_PRIV_TYPE_MASK) >> 12; /* Make sure the driver doesn't goof up */ if (max < num) num = max; return num * iw_priv_type_size[type]; } /* * Wrapper to call a private Wireless Extension handler. * We do various checks and also take care of moving data between * user space and kernel space. * It's not as nice and slimline as the standard wrapper. The cause * is struct iw_priv_args, which was not really designed for the * job we are going here. * * IMPORTANT : This function prevent to set and get data on the same * IOCTL and enforce the SET/GET convention. Not doing it would be * far too hairy... * If you need to set and get data at the same time, please don't use * a iw_handler but process it in your ioctl handler (i.e. use the * old driver API). */ static int get_priv_descr_and_size(struct net_device *dev, unsigned int cmd, const struct iw_priv_args **descrp) { const struct iw_priv_args *descr; int i, extra_size; descr = NULL; for (i = 0; i < dev->wireless_handlers->num_private_args; i++) { if (cmd == dev->wireless_handlers->private_args[i].cmd) { descr = &dev->wireless_handlers->private_args[i]; break; } } extra_size = 0; if (descr) { if (IW_IS_SET(cmd)) { int offset = 0; /* For sub-ioctls */ /* Check for sub-ioctl handler */ if (descr->name[0] == '\0') /* Reserve one int for sub-ioctl index */ offset = sizeof(__u32); /* Size of set arguments */ extra_size = get_priv_size(descr->set_args); /* Does it fits in iwr ? */ if ((descr->set_args & IW_PRIV_SIZE_FIXED) && ((extra_size + offset) <= IFNAMSIZ)) extra_size = 0; } else { /* Size of get arguments */ extra_size = get_priv_size(descr->get_args); /* Does it fits in iwr ? */ if ((descr->get_args & IW_PRIV_SIZE_FIXED) && (extra_size <= IFNAMSIZ)) extra_size = 0; } } *descrp = descr; return extra_size; } static int ioctl_private_iw_point(struct iw_point *iwp, unsigned int cmd, const struct iw_priv_args *descr, iw_handler handler, struct net_device *dev, struct iw_request_info *info, int extra_size) { char *extra; int err; /* Check what user space is giving us */ if (IW_IS_SET(cmd)) { if (!iwp->pointer && iwp->length != 0) return -EFAULT; if (iwp->length > (descr->set_args & IW_PRIV_SIZE_MASK)) return -E2BIG; } else if (!iwp->pointer) return -EFAULT; extra = kmalloc(extra_size, GFP_KERNEL); if (!extra) return -ENOMEM; /* If it is a SET, get all the extra data in here */ if (IW_IS_SET(cmd) && (iwp->length != 0)) { if (copy_from_user(extra, iwp->pointer, extra_size)) { err = -EFAULT; goto out; } } /* Call the handler */ err = handler(dev, info, (union iwreq_data *) iwp, extra); /* If we have something to return to the user */ if (!err && IW_IS_GET(cmd)) { /* Adjust for the actual length if it's variable, * avoid leaking kernel bits outside. */ if (!(descr->get_args & IW_PRIV_SIZE_FIXED)) extra_size = adjust_priv_size(descr->get_args, iwp); if (copy_to_user(iwp->pointer, extra, extra_size)) err = -EFAULT; } out: kfree(extra); return err; } int ioctl_private_call(struct net_device *dev, struct iwreq *iwr, unsigned int cmd, struct iw_request_info *info, iw_handler handler) { int extra_size = 0, ret = -EINVAL; const struct iw_priv_args *descr; extra_size = get_priv_descr_and_size(dev, cmd, &descr); /* Check if we have a pointer to user space data or not. */ if (extra_size == 0) { /* No extra arguments. Trivial to handle */ ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u)); } else { ret = ioctl_private_iw_point(&iwr->u.data, cmd, descr, handler, dev, info, extra_size); } /* Call commit handler if needed and defined */ if (ret == -EIWCOMMIT) ret = call_commit_handler(dev); return ret; } #ifdef CONFIG_COMPAT int compat_private_call(struct net_device *dev, struct iwreq *iwr, unsigned int cmd, struct iw_request_info *info, iw_handler handler) { const struct iw_priv_args *descr; int ret, extra_size; extra_size = get_priv_descr_and_size(dev, cmd, &descr); /* Check if we have a pointer to user space data or not. */ if (extra_size == 0) { /* No extra arguments. Trivial to handle */ ret = handler(dev, info, &(iwr->u), (char *) &(iwr->u)); } else { struct compat_iw_point *iwp_compat; struct iw_point iwp; iwp_compat = (struct compat_iw_point *) &iwr->u.data; iwp.pointer = compat_ptr(iwp_compat->pointer); iwp.length = iwp_compat->length; iwp.flags = iwp_compat->flags; ret = ioctl_private_iw_point(&iwp, cmd, descr, handler, dev, info, extra_size); iwp_compat->pointer = ptr_to_compat(iwp.pointer); iwp_compat->length = iwp.length; iwp_compat->flags = iwp.flags; } /* Call commit handler if needed and defined */ if (ret == -EIWCOMMIT) ret = call_commit_handler(dev); return ret; } #endif