/* src/p80211/p80211conv.c
*
* Ether/802.11 conversions and packet buffer routines
*
* Copyright (C) 1999 AbsoluteValue Systems, Inc. All Rights Reserved.
* --------------------------------------------------------------------
*
* linux-wlan
*
* The contents of this file are subject to the Mozilla Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License version 2 (the "GPL"), in which
* case the provisions of the GPL are applicable instead of the
* above. If you wish to allow the use of your version of this file
* only under the terms of the GPL and not to allow others to use
* your version of this file under the MPL, indicate your decision
* by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL. If you do not delete
* the provisions above, a recipient may use your version of this
* file under either the MPL or the GPL.
*
* --------------------------------------------------------------------
*
* Inquiries regarding the linux-wlan Open Source project can be
* made directly to:
*
* AbsoluteValue Systems Inc.
* info@linux-wlan.com
* http://www.linux-wlan.com
*
* --------------------------------------------------------------------
*
* Portions of the development of this software were funded by
* Intersil Corporation as part of PRISM(R) chipset product development.
*
* --------------------------------------------------------------------
*
* This file defines the functions that perform Ethernet to/from
* 802.11 frame conversions.
*
* --------------------------------------------------------------------
*
*================================================================ */
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/skbuff.h>
#include <linux/slab.h>
#include <linux/wireless.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/if_ether.h>
#include <linux/byteorder/generic.h>
#include <asm/byteorder.h>
#include "p80211types.h"
#include "p80211hdr.h"
#include "p80211conv.h"
#include "p80211mgmt.h"
#include "p80211msg.h"
#include "p80211netdev.h"
#include "p80211ioctl.h"
#include "p80211req.h"
static u8 oui_rfc1042[] = { 0x00, 0x00, 0x00 };
static u8 oui_8021h[] = { 0x00, 0x00, 0xf8 };
/*----------------------------------------------------------------
* p80211pb_ether_to_80211
*
* Uses the contents of the ether frame and the etherconv setting
* to build the elements of the 802.11 frame.
*
* We don't actually set
* up the frame header here. That's the MAC's job. We're only handling
* conversion of DIXII or 802.3+LLC frames to something that works
* with 802.11.
*
* Note -- 802.11 header is NOT part of the skb. Likewise, the 802.11
* FCS is also not present and will need to be added elsewhere.
*
* Arguments:
* ethconv Conversion type to perform
* skb skbuff containing the ether frame
* p80211_hdr 802.11 header
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int skb_ether_to_p80211(wlandevice_t *wlandev, u32 ethconv,
struct sk_buff *skb, union p80211_hdr *p80211_hdr,
struct p80211_metawep *p80211_wep)
{
u16 fc;
u16 proto;
struct wlan_ethhdr e_hdr;
struct wlan_llc *e_llc;
struct wlan_snap *e_snap;
int foo;
memcpy(&e_hdr, skb->data, sizeof(e_hdr));
if (skb->len <= 0) {
pr_debug("zero-length skb!\n");
return 1;
}
if (ethconv == WLAN_ETHCONV_ENCAP) { /* simplest case */
pr_debug("ENCAP len: %d\n", skb->len);
/* here, we don't care what kind of ether frm. Just stick it */
/* in the 80211 payload */
/* which is to say, leave the skb alone. */
} else {
/* step 1: classify ether frame, DIX or 802.3? */
proto = ntohs(e_hdr.type);
if (proto <= 1500) {
pr_debug("802.3 len: %d\n", skb->len);
/* codes <= 1500 reserved for 802.3 lengths */
/* it's 802.3, pass ether payload unchanged, */
/* trim off ethernet header */
skb_pull(skb, WLAN_ETHHDR_LEN);
/* leave off any PAD octets. */
skb_trim(skb, proto);
} else {
pr_debug("DIXII len: %d\n", skb->len);
/* it's DIXII, time for some conversion */
/* trim off ethernet header */
skb_pull(skb, WLAN_ETHHDR_LEN);
/* tack on SNAP */
e_snap =
(struct wlan_snap *) skb_push(skb,
sizeof(struct wlan_snap));
e_snap->type = htons(proto);
if (ethconv == WLAN_ETHCONV_8021h
&& p80211_stt_findproto(proto)) {
memcpy(e_snap->oui, oui_8021h,
WLAN_IEEE_OUI_LEN);
} else {
memcpy(e_snap->oui, oui_rfc1042,
WLAN_IEEE_OUI_LEN);
}
/* tack on llc */
e_llc =
(struct wlan_llc *) skb_push(skb,
sizeof(struct wlan_llc));
e_llc->dsap = 0xAA; /* SNAP, see IEEE 802 */
e_llc->ssap = 0xAA;
e_llc->ctl = 0x03;
}
}
/* Set up the 802.11 header */
/* It's a data frame */
fc = cpu_to_le16(WLAN_SET_FC_FTYPE(WLAN_FTYPE_DATA) |
WLAN_SET_FC_FSTYPE(WLAN_FSTYPE_DATAONLY));
switch (wlandev->macmode) {
case WLAN_MACMODE_IBSS_STA:
memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
memcpy(p80211_hdr->a3.a3, wlandev->bssid, ETH_ALEN);
break;
case WLAN_MACMODE_ESS_STA:
fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
memcpy(p80211_hdr->a3.a1, wlandev->bssid, ETH_ALEN);
memcpy(p80211_hdr->a3.a2, wlandev->netdev->dev_addr, ETH_ALEN);
memcpy(p80211_hdr->a3.a3, &e_hdr.daddr, ETH_ALEN);
break;
case WLAN_MACMODE_ESS_AP:
fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
memcpy(p80211_hdr->a3.a1, &e_hdr.daddr, ETH_ALEN);
memcpy(p80211_hdr->a3.a2, wlandev->bssid, ETH_ALEN);
memcpy(p80211_hdr->a3.a3, &e_hdr.saddr, ETH_ALEN);
break;
default:
printk(KERN_ERR
"Error: Converting eth to wlan in unknown mode.\n");
return 1;
break;
}
p80211_wep->data = NULL;
if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED)
&& (wlandev->hostwep & HOSTWEP_ENCRYPT)) {
/* XXXX need to pick keynum other than default? */
p80211_wep->data = kmalloc(skb->len, GFP_ATOMIC);
foo = wep_encrypt(wlandev, skb->data, p80211_wep->data,
skb->len,
(wlandev->hostwep & HOSTWEP_DEFAULTKEY_MASK),
p80211_wep->iv, p80211_wep->icv);
if (foo) {
printk(KERN_WARNING
"Host en-WEP failed, dropping frame (%d).\n",
foo);
return 2;
}
fc |= cpu_to_le16(WLAN_SET_FC_ISWEP(1));
}
/* skb->nh.raw = skb->data; */
p80211_hdr->a3.fc = fc;
p80211_hdr->a3.dur = 0;
p80211_hdr->a3.seq = 0;
return 0;
}
/* jkriegl: from orinoco, modified */
static void orinoco_spy_gather(wlandevice_t *wlandev, char *mac,
struct p80211_rxmeta *rxmeta)
{
int i;
/* Gather wireless spy statistics: for each packet, compare the
* source address with out list, and if match, get the stats... */
for (i = 0; i < wlandev->spy_number; i++) {
if (!memcmp(wlandev->spy_address[i], mac, ETH_ALEN)) {
memcpy(wlandev->spy_address[i], mac, ETH_ALEN);
wlandev->spy_stat[i].level = rxmeta->signal;
wlandev->spy_stat[i].noise = rxmeta->noise;
wlandev->spy_stat[i].qual =
(rxmeta->signal >
rxmeta->noise) ? (rxmeta->signal -
rxmeta->noise) : 0;
wlandev->spy_stat[i].updated = 0x7;
}
}
}
/*----------------------------------------------------------------
* p80211pb_80211_to_ether
*
* Uses the contents of a received 802.11 frame and the etherconv
* setting to build an ether frame.
*
* This function extracts the src and dest address from the 802.11
* frame to use in the construction of the eth frame.
*
* Arguments:
* ethconv Conversion type to perform
* skb Packet buffer containing the 802.11 frame
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int skb_p80211_to_ether(wlandevice_t *wlandev, u32 ethconv,
struct sk_buff *skb)
{
netdevice_t *netdev = wlandev->netdev;
u16 fc;
unsigned int payload_length;
unsigned int payload_offset;
u8 daddr[WLAN_ETHADDR_LEN];
u8 saddr[WLAN_ETHADDR_LEN];
union p80211_hdr *w_hdr;
struct wlan_ethhdr *e_hdr;
struct wlan_llc *e_llc;
struct wlan_snap *e_snap;
int foo;
payload_length = skb->len - WLAN_HDR_A3_LEN - WLAN_CRC_LEN;
payload_offset = WLAN_HDR_A3_LEN;
w_hdr = (union p80211_hdr *) skb->data;
/* setup some vars for convenience */
fc = le16_to_cpu(w_hdr->a3.fc);
if ((WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0)) {
memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
} else if ((WLAN_GET_FC_TODS(fc) == 0)
&& (WLAN_GET_FC_FROMDS(fc) == 1)) {
memcpy(daddr, w_hdr->a3.a1, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
} else if ((WLAN_GET_FC_TODS(fc) == 1)
&& (WLAN_GET_FC_FROMDS(fc) == 0)) {
memcpy(daddr, w_hdr->a3.a3, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a3.a2, WLAN_ETHADDR_LEN);
} else {
payload_offset = WLAN_HDR_A4_LEN;
if (payload_length < WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN) {
printk(KERN_ERR "A4 frame too short!\n");
return 1;
}
payload_length -= (WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN);
memcpy(daddr, w_hdr->a4.a3, WLAN_ETHADDR_LEN);
memcpy(saddr, w_hdr->a4.a4, WLAN_ETHADDR_LEN);
}
/* perform de-wep if necessary.. */
if ((wlandev->hostwep & HOSTWEP_PRIVACYINVOKED) && WLAN_GET_FC_ISWEP(fc)
&& (wlandev->hostwep & HOSTWEP_DECRYPT)) {
if (payload_length <= 8) {
printk(KERN_ERR "WEP frame too short (%u).\n",
skb->len);
return 1;
}
foo = wep_decrypt(wlandev, skb->data + payload_offset + 4,
payload_length - 8, -1,
skb->data + payload_offset,
skb->data + payload_offset +
payload_length - 4);
if (foo) {
/* de-wep failed, drop skb. */
pr_debug("Host de-WEP failed, dropping frame (%d).\n",
foo);
wlandev->rx.decrypt_err++;
return 2;
}
/* subtract the IV+ICV length off the payload */
payload_length -= 8;
/* chop off the IV */
skb_pull(skb, 4);
/* chop off the ICV. */
skb_trim(skb, skb->len - 4);
wlandev->rx.decrypt++;
}
e_hdr = (struct wlan_ethhdr *) (skb->data + payload_offset);
e_llc = (struct wlan_llc *) (skb->data + payload_offset);
e_snap =
(struct wlan_snap *) (skb->data + payload_offset +
sizeof(struct wlan_llc));
/* Test for the various encodings */
if ((payload_length >= sizeof(struct wlan_ethhdr)) &&
(e_llc->dsap != 0xaa || e_llc->ssap != 0xaa) &&
((memcmp(daddr, e_hdr->daddr, WLAN_ETHADDR_LEN) == 0) ||
(memcmp(saddr, e_hdr->saddr, WLAN_ETHADDR_LEN) == 0))) {
pr_debug("802.3 ENCAP len: %d\n", payload_length);
/* 802.3 Encapsulated */
/* Test for an overlength frame */
if (payload_length > (netdev->mtu + WLAN_ETHHDR_LEN)) {
/* A bogus length ethfrm has been encap'd. */
/* Is someone trying an oflow attack? */
printk(KERN_ERR "ENCAP frame too large (%d > %d)\n",
payload_length, netdev->mtu + WLAN_ETHHDR_LEN);
return 1;
}
/* Chop off the 802.11 header. it's already sane. */
skb_pull(skb, payload_offset);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
} else if ((payload_length >= sizeof(struct wlan_llc) +
sizeof(struct wlan_snap))
&& (e_llc->dsap == 0xaa)
&& (e_llc->ssap == 0xaa)
&& (e_llc->ctl == 0x03)
&&
(((memcmp(e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN) == 0)
&& (ethconv == WLAN_ETHCONV_8021h)
&& (p80211_stt_findproto(le16_to_cpu(e_snap->type))))
|| (memcmp(e_snap->oui, oui_rfc1042, WLAN_IEEE_OUI_LEN) !=
0))) {
pr_debug("SNAP+RFC1042 len: %d\n", payload_length);
/* it's a SNAP + RFC1042 frame && protocol is in STT */
/* build 802.3 + RFC1042 */
/* Test for an overlength frame */
if (payload_length > netdev->mtu) {
/* A bogus length ethfrm has been sent. */
/* Is someone trying an oflow attack? */
printk(KERN_ERR "SNAP frame too large (%d > %d)\n",
payload_length, netdev->mtu);
return 1;
}
/* chop 802.11 header from skb. */
skb_pull(skb, payload_offset);
/* create 802.3 header at beginning of skb. */
e_hdr = (struct wlan_ethhdr *) skb_push(skb, WLAN_ETHHDR_LEN);
memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
e_hdr->type = htons(payload_length);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
} else if ((payload_length >= sizeof(struct wlan_llc) +
sizeof(struct wlan_snap))
&& (e_llc->dsap == 0xaa)
&& (e_llc->ssap == 0xaa)
&& (e_llc->ctl == 0x03)) {
pr_debug("802.1h/RFC1042 len: %d\n", payload_length);
/* it's an 802.1h frame || (an RFC1042 && protocol not in STT)
build a DIXII + RFC894 */
/* Test for an overlength frame */
if ((payload_length - sizeof(struct wlan_llc) -
sizeof(struct wlan_snap))
> netdev->mtu) {
/* A bogus length ethfrm has been sent. */
/* Is someone trying an oflow attack? */
printk(KERN_ERR "DIXII frame too large (%ld > %d)\n",
(long int)(payload_length -
sizeof(struct wlan_llc) -
sizeof(struct wlan_snap)), netdev->mtu);
return 1;
}
/* chop 802.11 header from skb. */
skb_pull(skb, payload_offset);
/* chop llc header from skb. */
skb_pull(skb, sizeof(struct wlan_llc));
/* chop snap header from skb. */
skb_pull(skb, sizeof(struct wlan_snap));
/* create 802.3 header at beginning of skb. */
e_hdr = (struct wlan_ethhdr *) skb_push(skb, WLAN_ETHHDR_LEN);
e_hdr->type = e_snap->type;
memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
} else {
pr_debug("NON-ENCAP len: %d\n", payload_length);
/* any NON-ENCAP */
/* it's a generic 80211+LLC or IPX 'Raw 802.3' */
/* build an 802.3 frame */
/* allocate space and setup hostbuf */
/* Test for an overlength frame */
if (payload_length > netdev->mtu) {
/* A bogus length ethfrm has been sent. */
/* Is someone trying an oflow attack? */
printk(KERN_ERR "OTHER frame too large (%d > %d)\n",
payload_length, netdev->mtu);
return 1;
}
/* Chop off the 802.11 header. */
skb_pull(skb, payload_offset);
/* create 802.3 header at beginning of skb. */
e_hdr = (struct wlan_ethhdr *) skb_push(skb, WLAN_ETHHDR_LEN);
memcpy(e_hdr->daddr, daddr, WLAN_ETHADDR_LEN);
memcpy(e_hdr->saddr, saddr, WLAN_ETHADDR_LEN);
e_hdr->type = htons(payload_length);
/* chop off the 802.11 CRC */
skb_trim(skb, skb->len - WLAN_CRC_LEN);
}
/*
* Note that eth_type_trans() expects an skb w/ skb->data pointing
* at the MAC header, it then sets the following skb members:
* skb->mac_header,
* skb->data, and
* skb->pkt_type.
* It then _returns_ the value that _we're_ supposed to stuff in
* skb->protocol. This is nuts.
*/
skb->protocol = eth_type_trans(skb, netdev);
/* jkriegl: process signal and noise as set in hfa384x_int_rx() */
/* jkriegl: only process signal/noise if requested by iwspy */
if (wlandev->spy_number)
orinoco_spy_gather(wlandev, eth_hdr(skb)->h_source,
P80211SKB_RXMETA(skb));
/* Free the metadata */
p80211skb_rxmeta_detach(skb);
return 0;
}
/*----------------------------------------------------------------
* p80211_stt_findproto
*
* Searches the 802.1h Selective Translation Table for a given
* protocol.
*
* Arguments:
* proto protocl number (in host order) to search for.
*
* Returns:
* 1 - if the table is empty or a match is found.
* 0 - if the table is non-empty and a match is not found.
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int p80211_stt_findproto(u16 proto)
{
/* Always return found for now. This is the behavior used by the */
/* Zoom Win95 driver when 802.1h mode is selected */
/* TODO: If necessary, add an actual search we'll probably
need this to match the CMAC's way of doing things.
Need to do some testing to confirm.
*/
if (proto == 0x80f3) /* APPLETALK */
return 1;
return 0;
}
/*----------------------------------------------------------------
* p80211skb_rxmeta_detach
*
* Disconnects the frmmeta and rxmeta from an skb.
*
* Arguments:
* wlandev The wlandev this skb belongs to.
* skb The skb we're attaching to.
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
void p80211skb_rxmeta_detach(struct sk_buff *skb)
{
struct p80211_rxmeta *rxmeta;
struct p80211_frmmeta *frmmeta;
/* Sanity checks */
if (skb == NULL) { /* bad skb */
pr_debug("Called w/ null skb.\n");
goto exit;
}
frmmeta = P80211SKB_FRMMETA(skb);
if (frmmeta == NULL) { /* no magic */
pr_debug("Called w/ bad frmmeta magic.\n");
goto exit;
}
rxmeta = frmmeta->rx;
if (rxmeta == NULL) { /* bad meta ptr */
pr_debug("Called w/ bad rxmeta ptr.\n");
goto exit;
}
/* Free rxmeta */
kfree(rxmeta);
/* Clear skb->cb */
memset(skb->cb, 0, sizeof(skb->cb));
exit:
return;
}
/*----------------------------------------------------------------
* p80211skb_rxmeta_attach
*
* Allocates a p80211rxmeta structure, initializes it, and attaches
* it to an skb.
*
* Arguments:
* wlandev The wlandev this skb belongs to.
* skb The skb we're attaching to.
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
int p80211skb_rxmeta_attach(struct wlandevice *wlandev, struct sk_buff *skb)
{
int result = 0;
struct p80211_rxmeta *rxmeta;
struct p80211_frmmeta *frmmeta;
/* If these already have metadata, we error out! */
if (P80211SKB_RXMETA(skb) != NULL) {
printk(KERN_ERR "%s: RXmeta already attached!\n",
wlandev->name);
result = 0;
goto exit;
}
/* Allocate the rxmeta */
rxmeta = kzalloc(sizeof(struct p80211_rxmeta), GFP_ATOMIC);
if (rxmeta == NULL) {
printk(KERN_ERR "%s: Failed to allocate rxmeta.\n",
wlandev->name);
result = 1;
goto exit;
}
/* Initialize the rxmeta */
rxmeta->wlandev = wlandev;
rxmeta->hosttime = jiffies;
/* Overlay a frmmeta_t onto skb->cb */
memset(skb->cb, 0, sizeof(struct p80211_frmmeta));
frmmeta = (struct p80211_frmmeta *) (skb->cb);
frmmeta->magic = P80211_FRMMETA_MAGIC;
frmmeta->rx = rxmeta;
exit:
return result;
}
/*----------------------------------------------------------------
* p80211skb_free
*
* Frees an entire p80211skb by checking and freeing the meta struct
* and then freeing the skb.
*
* Arguments:
* wlandev The wlandev this skb belongs to.
* skb The skb we're attaching to.
*
* Returns:
* 0 on success, non-zero otherwise
*
* Call context:
* May be called in interrupt or non-interrupt context
----------------------------------------------------------------*/
void p80211skb_free(struct wlandevice *wlandev, struct sk_buff *skb)
{
struct p80211_frmmeta *meta;
meta = P80211SKB_FRMMETA(skb);
if (meta && meta->rx)
p80211skb_rxmeta_detach(skb);
else
printk(KERN_ERR "Freeing an skb (%p) w/ no frmmeta.\n", skb);
dev_kfree_skb(skb);
return;
}