[PATCH 2/2] staging: wlan-ng: Avoid duplicate header in tx/rx frames
From: Kees Cook
Date: Thu Aug 19 2021 - 13:45:50 EST
Instead of open-coding the same header details in the tx/rx frames,
directly include the actual struct. Rename associated variables to the
more verbose of the two versions. This also has the benefit of being
able to replace a field-spanning memcpy() with a direct assignment,
helping clear the way for coming FORTIFY_SOURCE improvements.
"diffoscope" reports no object code differences after this change,
excepting the selection of different registers when switching from
memcpy() to direct assignment:
--- drivers/staging/wlan-ng/prism2usb.o.before
+++ drivers/staging/wlan-ng/prism2usb.o.after
├── objdump --line-numbers --disassemble --demangle --reloc --no-show-raw-insn --section=.text {}
│ @@ -4887,24 +4887,24 @@
│ sub %rdi,%rcx
│ add $0x3c,%ecx
│ shr $0x3,%ecx
│ rep stos %rax,%es:(%rdi)
│ mov $0x8,%eax
│ movl $0x123,0x23e(%rbx)
│ mov %ax,0x244(%rbx)
│ - mov (%rdx),%rcx
│ - mov %rcx,0x246(%rbx)
│ - mov 0x8(%rdx),%rcx
│ - mov %rcx,0x24e(%rbx)
│ - mov 0x10(%rdx),%rcx
│ - mov %rcx,0x256(%rbx)
│ - mov 0x18(%rdx),%ecx
│ - mov %ecx,0x25e(%rbx)
│ - movzwl 0x1c(%rdx),%edx
│ - mov %dx,0x262(%rbx)
│ + mov (%rdx),%rax
│ + mov %rax,0x246(%rbx)
│ + mov 0x8(%rdx),%rax
│ + mov %rax,0x24e(%rbx)
│ + mov 0x10(%rdx),%rax
│ + mov %rax,0x256(%rbx)
│ + mov 0x18(%rdx),%eax
│ + mov %eax,0x25e(%rbx)
│ + movzwl 0x1c(%rdx),%eax
│ + mov %ax,0x262(%rbx)
│ cmpq $0x0,0x0(%rbp)
│ movzwl 0x70(%rsi),%eax
│ je 477a <hfa384x_drvr_txframe+0xba>
│ add $0x8,%eax
│ mov $0x44,%r12d
│ mov %ax,0x264(%rbx)
│ mov 0x70(%r13),%edx
Cc: Romain Perier <romain.perier@xxxxxxxxx>
Cc: Allen Pais <apais@xxxxxxxxxxxxxxxxxxx>
Cc: Ivan Safonov <insafonov@xxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: linux-staging@xxxxxxxxxxxxxxx
Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
drivers/staging/wlan-ng/hfa384x.h | 17 ++---------
drivers/staging/wlan-ng/hfa384x_usb.c | 11 +++----
drivers/staging/wlan-ng/p80211conv.c | 42 +++++++++++++-------------
drivers/staging/wlan-ng/p80211hdr.h | 14 ++++-----
drivers/staging/wlan-ng/p80211netdev.c | 6 ++--
drivers/staging/wlan-ng/prism2sta.c | 2 +-
6 files changed, 39 insertions(+), 53 deletions(-)
diff --git a/drivers/staging/wlan-ng/hfa384x.h b/drivers/staging/wlan-ng/hfa384x.h
index f1bc1f2816af..75ed8bc4bbc1 100644
--- a/drivers/staging/wlan-ng/hfa384x.h
+++ b/drivers/staging/wlan-ng/hfa384x.h
@@ -475,14 +475,7 @@ struct hfa384x_tx_frame {
u16 tx_control;
/*-- 802.11 Header Information --*/
-
- u16 frame_control;
- u16 duration_id;
- u8 address1[6];
- u8 address2[6];
- u8 address3[6];
- u16 sequence_control;
- u8 address4[6];
+ struct p80211_hdr hdr;
__le16 data_len; /* little endian format */
/*-- 802.3 Header Information --*/
@@ -541,13 +534,7 @@ struct hfa384x_rx_frame {
u16 reserved2;
/*-- 802.11 Header Information (802.11 byte order) --*/
- __le16 frame_control;
- u16 duration_id;
- u8 address1[6];
- u8 address2[6];
- u8 address3[6];
- u16 sequence_control;
- u8 address4[6];
+ struct p80211_hdr hdr;
__le16 data_len; /* hfa384x (little endian) format */
/*-- 802.3 Header Information --*/
diff --git a/drivers/staging/wlan-ng/hfa384x_usb.c b/drivers/staging/wlan-ng/hfa384x_usb.c
index 0bf71f395b37..8c8524679ba3 100644
--- a/drivers/staging/wlan-ng/hfa384x_usb.c
+++ b/drivers/staging/wlan-ng/hfa384x_usb.c
@@ -2516,8 +2516,7 @@ int hfa384x_drvr_txframe(struct hfa384x *hw, struct sk_buff *skb,
cpu_to_le16s(&hw->txbuff.txfrm.desc.tx_control);
/* copy the header over to the txdesc */
- memcpy(&hw->txbuff.txfrm.desc.frame_control, p80211_hdr,
- sizeof(struct p80211_hdr));
+ hw->txbuff.txfrm.desc.hdr = *p80211_hdr;
/* if we're using host WEP, increase size by IV+ICV */
if (p80211_wep->data) {
@@ -3258,7 +3257,7 @@ static void hfa384x_usbin_rx(struct wlandevice *wlandev, struct sk_buff *skb)
switch (status) {
case 0:
- fc = le16_to_cpu(usbin->rxfrm.desc.frame_control);
+ fc = le16_to_cpu(usbin->rxfrm.desc.hdr.frame_control);
/* If exclude and we receive an unencrypted, drop it */
if ((wlandev->hostwep & HOSTWEP_EXCLUDEUNENCRYPTED) &&
@@ -3278,7 +3277,7 @@ static void hfa384x_usbin_rx(struct wlandevice *wlandev, struct sk_buff *skb)
* with an "overlapping" copy
*/
memmove(skb_push(skb, hdrlen),
- &usbin->rxfrm.desc.frame_control, hdrlen);
+ &usbin->rxfrm.desc.hdr, hdrlen);
skb->dev = wlandev->netdev;
@@ -3356,7 +3355,7 @@ static void hfa384x_int_rxmonitor(struct wlandevice *wlandev,
/* Remember the status, time, and data_len fields are in host order */
/* Figure out how big the frame is */
- fc = le16_to_cpu(rxdesc->frame_control);
+ fc = le16_to_cpu(rxdesc->hdr.frame_control);
hdrlen = p80211_headerlen(fc);
datalen = le16_to_cpu(rxdesc->data_len);
@@ -3404,7 +3403,7 @@ static void hfa384x_int_rxmonitor(struct wlandevice *wlandev,
/* Copy the 802.11 header to the skb
* (ctl frames may be less than a full header)
*/
- skb_put_data(skb, &rxdesc->frame_control, hdrlen);
+ skb_put_data(skb, &rxdesc->hdr.frame_control, hdrlen);
/* If any, copy the data from the card to the skb */
if (datalen > 0) {
diff --git a/drivers/staging/wlan-ng/p80211conv.c b/drivers/staging/wlan-ng/p80211conv.c
index 0b3ba03c1f1f..59b25ca50d15 100644
--- a/drivers/staging/wlan-ng/p80211conv.c
+++ b/drivers/staging/wlan-ng/p80211conv.c
@@ -175,21 +175,21 @@ int skb_ether_to_p80211(struct wlandevice *wlandev, u32 ethconv,
switch (wlandev->macmode) {
case WLAN_MACMODE_IBSS_STA:
- memcpy(p80211_hdr->a1, &e_hdr.daddr, ETH_ALEN);
- memcpy(p80211_hdr->a2, wlandev->netdev->dev_addr, ETH_ALEN);
- memcpy(p80211_hdr->a3, wlandev->bssid, ETH_ALEN);
+ memcpy(p80211_hdr->address1, &e_hdr.daddr, ETH_ALEN);
+ memcpy(p80211_hdr->address2, wlandev->netdev->dev_addr, ETH_ALEN);
+ memcpy(p80211_hdr->address3, wlandev->bssid, ETH_ALEN);
break;
case WLAN_MACMODE_ESS_STA:
fc |= cpu_to_le16(WLAN_SET_FC_TODS(1));
- memcpy(p80211_hdr->a1, wlandev->bssid, ETH_ALEN);
- memcpy(p80211_hdr->a2, wlandev->netdev->dev_addr, ETH_ALEN);
- memcpy(p80211_hdr->a3, &e_hdr.daddr, ETH_ALEN);
+ memcpy(p80211_hdr->address1, wlandev->bssid, ETH_ALEN);
+ memcpy(p80211_hdr->address2, wlandev->netdev->dev_addr, ETH_ALEN);
+ memcpy(p80211_hdr->address3, &e_hdr.daddr, ETH_ALEN);
break;
case WLAN_MACMODE_ESS_AP:
fc |= cpu_to_le16(WLAN_SET_FC_FROMDS(1));
- memcpy(p80211_hdr->a1, &e_hdr.daddr, ETH_ALEN);
- memcpy(p80211_hdr->a2, wlandev->bssid, ETH_ALEN);
- memcpy(p80211_hdr->a3, &e_hdr.saddr, ETH_ALEN);
+ memcpy(p80211_hdr->address1, &e_hdr.daddr, ETH_ALEN);
+ memcpy(p80211_hdr->address2, wlandev->bssid, ETH_ALEN);
+ memcpy(p80211_hdr->address3, &e_hdr.saddr, ETH_ALEN);
break;
default:
netdev_err(wlandev->netdev,
@@ -222,9 +222,9 @@ int skb_ether_to_p80211(struct wlandevice *wlandev, u32 ethconv,
/* skb->nh.raw = skb->data; */
- p80211_hdr->fc = fc;
- p80211_hdr->dur = 0;
- p80211_hdr->seq = 0;
+ p80211_hdr->frame_control = fc;
+ p80211_hdr->duration_id = 0;
+ p80211_hdr->sequence_control = 0;
return 0;
}
@@ -294,18 +294,18 @@ int skb_p80211_to_ether(struct wlandevice *wlandev, u32 ethconv,
w_hdr = (struct p80211_hdr *)skb->data;
/* setup some vars for convenience */
- fc = le16_to_cpu(w_hdr->fc);
+ fc = le16_to_cpu(w_hdr->frame_control);
if ((WLAN_GET_FC_TODS(fc) == 0) && (WLAN_GET_FC_FROMDS(fc) == 0)) {
- ether_addr_copy(daddr, w_hdr->a1);
- ether_addr_copy(saddr, w_hdr->a2);
+ ether_addr_copy(daddr, w_hdr->address1);
+ ether_addr_copy(saddr, w_hdr->address2);
} else if ((WLAN_GET_FC_TODS(fc) == 0) &&
(WLAN_GET_FC_FROMDS(fc) == 1)) {
- ether_addr_copy(daddr, w_hdr->a1);
- ether_addr_copy(saddr, w_hdr->a3);
+ ether_addr_copy(daddr, w_hdr->address1);
+ ether_addr_copy(saddr, w_hdr->address3);
} else if ((WLAN_GET_FC_TODS(fc) == 1) &&
(WLAN_GET_FC_FROMDS(fc) == 0)) {
- ether_addr_copy(daddr, w_hdr->a3);
- ether_addr_copy(saddr, w_hdr->a2);
+ ether_addr_copy(daddr, w_hdr->address3);
+ ether_addr_copy(saddr, w_hdr->address2);
} else {
payload_offset = WLAN_HDR_A4_LEN;
if (payload_length < WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN) {
@@ -313,8 +313,8 @@ int skb_p80211_to_ether(struct wlandevice *wlandev, u32 ethconv,
return 1;
}
payload_length -= (WLAN_HDR_A4_LEN - WLAN_HDR_A3_LEN);
- ether_addr_copy(daddr, w_hdr->a3);
- ether_addr_copy(saddr, w_hdr->a4);
+ ether_addr_copy(daddr, w_hdr->address3);
+ ether_addr_copy(saddr, w_hdr->address4);
}
/* perform de-wep if necessary.. */
diff --git a/drivers/staging/wlan-ng/p80211hdr.h b/drivers/staging/wlan-ng/p80211hdr.h
index 93dd8ff1940c..dd1fb99bf340 100644
--- a/drivers/staging/wlan-ng/p80211hdr.h
+++ b/drivers/staging/wlan-ng/p80211hdr.h
@@ -149,13 +149,13 @@
/* Generic 802.11 Header types */
struct p80211_hdr {
- u16 fc;
- u16 dur;
- u8 a1[ETH_ALEN];
- u8 a2[ETH_ALEN];
- u8 a3[ETH_ALEN];
- u16 seq;
- u8 a4[ETH_ALEN];
+ u16 frame_control;
+ u16 duration_id;
+ u8 address1[ETH_ALEN];
+ u8 address2[ETH_ALEN];
+ u8 address3[ETH_ALEN];
+ u16 sequence_control;
+ u8 address4[ETH_ALEN];
} __packed;
/* Frame and header length macros */
diff --git a/drivers/staging/wlan-ng/p80211netdev.c b/drivers/staging/wlan-ng/p80211netdev.c
index 53cbac890614..2a3f9385ab3f 100644
--- a/drivers/staging/wlan-ng/p80211netdev.c
+++ b/drivers/staging/wlan-ng/p80211netdev.c
@@ -238,7 +238,7 @@ static int p80211_convert_to_ether(struct wlandevice *wlandev,
struct p80211_hdr *hdr;
hdr = (struct p80211_hdr *)skb->data;
- if (p80211_rx_typedrop(wlandev, le16_to_cpu(hdr->fc)))
+ if (p80211_rx_typedrop(wlandev, le16_to_cpu(hdr->frame_control)))
return CONV_TO_ETHER_SKIPPED;
/* perform mcast filtering: allow my local address through but reject
@@ -246,8 +246,8 @@ static int p80211_convert_to_ether(struct wlandevice *wlandev,
*/
if (wlandev->netdev->flags & IFF_ALLMULTI) {
if (!ether_addr_equal_unaligned(wlandev->netdev->dev_addr,
- hdr->a1)) {
- if (!is_multicast_ether_addr(hdr->a1))
+ hdr->address1)) {
+ if (!is_multicast_ether_addr(hdr->address1))
return CONV_TO_ETHER_SKIPPED;
}
}
diff --git a/drivers/staging/wlan-ng/prism2sta.c b/drivers/staging/wlan-ng/prism2sta.c
index 1f9ba26f1f36..f67b7405156a 100644
--- a/drivers/staging/wlan-ng/prism2sta.c
+++ b/drivers/staging/wlan-ng/prism2sta.c
@@ -250,7 +250,7 @@ static int prism2sta_txframe(struct wlandevice *wlandev, struct sk_buff *skb,
/* If necessary, set the 802.11 WEP bit */
if ((wlandev->hostwep & (HOSTWEP_PRIVACYINVOKED | HOSTWEP_ENCRYPT)) ==
HOSTWEP_PRIVACYINVOKED) {
- p80211_hdr->fc |= cpu_to_le16(WLAN_SET_FC_ISWEP(1));
+ p80211_hdr->frame_control |= cpu_to_le16(WLAN_SET_FC_ISWEP(1));
}
return hfa384x_drvr_txframe(hw, skb, p80211_hdr, p80211_wep);
--
2.30.2