This was one of my first attempts, and so I was sure to miss something.. I've
incorporated all the updates in this patch.. Let me know what you think about
this..
net/cadence_gem: Updating the GEM MAC IP to properly filter out the multicast
addresses.
The current code makes a bad assumption that the most-significant byte
of the MAC address is used to determine if the address is multicast or
unicast, but in reality only a single bit is used to determine this.
This caused IPv6 to not work.. Fix is now in place and has been tested
with ZCU102-A53 / IPv6 on a TAP interface. Works well..
Signed-off-by: Bilal Wasim <bilal_wa...@mentor.com>
---
hw/net/cadence_gem.c | 21 ++++++++++++++-------
1 file changed, 14 insertions(+), 7 deletions(-)
diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c
index b8be73dc55..98efb93f8a 100644
--- a/hw/net/cadence_gem.c
+++ b/hw/net/cadence_gem.c
@@ -34,6 +34,7 @@
#include "qemu/module.h"
#include "sysemu/dma.h"
#include "net/checksum.h"
+#include "net/eth.h"
#ifdef CADENCE_GEM_ERR_DEBUG
#define DB_PRINT(...) do { \
@@ -315,6 +316,12 @@
#define GEM_MODID_VALUE 0x00020118
+/* IEEE has specified that the most significant bit of the most significant
byte be used for
+ * distinguishing between Unicast and Multicast addresses.
+ * If its a 1, that means multicast, 0 means unicast. */
+#define IS_MULTICAST(address) is_multicast_ether_addr(address)
+#define IS_UNICAST(address) is_unicast_ether_addr(address)
+
static inline uint64_t tx_desc_get_buffer(CadenceGEMState *s, uint32_t *desc)
{
uint64_t ret = desc[0];
@@ -601,7 +608,7 @@ static void gem_receive_updatestats(CadenceGEMState *s,
const uint8_t *packet,
}
/* Error-free Multicast Frames counter */
- if (packet[0] == 0x01) {
+ if (IS_MULTICAST(packet)) {
s->regs[GEM_RXMULTICNT]++;
}
@@ -690,21 +697,21 @@ static int gem_mac_address_filter(CadenceGEMState *s,
const uint8_t *packet)
}
/* Accept packets -w- hash match? */
- if ((packet[0] == 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_MCAST_HASH)) ||
- (packet[0] != 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_UCAST_HASH))) {
+ if ((IS_MULTICAST(packet) && (s->regs[GEM_NWCFG] & GEM_NWCFG_MCAST_HASH))
||
+ (IS_UNICAST(packet) && (s->regs[GEM_NWCFG] & GEM_NWCFG_UCAST_HASH)))
{
unsigned hash_index;
hash_index = calc_mac_hash(packet);
if (hash_index < 32) {
if (s->regs[GEM_HASHLO] & (1<<hash_index)) {
- return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
- GEM_RX_UNICAST_HASH_ACCEPT;
+ return IS_MULTICAST(packet) ? GEM_RX_MULTICAST_HASH_ACCEPT :
+ GEM_RX_UNICAST_HASH_ACCEPT;
}
} else {
hash_index -= 32;
if (s->regs[GEM_HASHHI] & (1<<hash_index)) {
- return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
- GEM_RX_UNICAST_HASH_ACCEPT;
+ return IS_MULTICAST(packet) ? GEM_RX_MULTICAST_HASH_ACCEPT :
+ GEM_RX_UNICAST_HASH_ACCEPT;
}
}
}
--
2.19.1.windows.1
------------------------------------------------------------------------------------------------------------------------------
-----Original Message-----
From: Edgar E. Iglesias [mailto:edgar.igles...@gmail.com]
Sent: Thursday, November 28, 2019 9:00 PM
To: Wasim, Bilal <bilal_wa...@mentor.com>
Cc: qemu-devel@nongnu.org; alist...@alistair23.me; peter.mayd...@linaro.org;
qemu-...@nongnu.org
Subject: Re: [PATCH] Updating the GEM MAC IP to properly filter out the
multicast addresses
On Thu, Nov 28, 2019 at 03:10:16PM +0000, Wasim, Bilal wrote:
> [PATCH] Updating the GEM MAC IP to properly filter out the multicast
> addresses. The current code makes a bad assumption that the
> most-significant byte of the MAC address is used to determine if the
> address is multicast or unicast, but in reality only a single bit is
> used to determine this. This caused IPv6 to not work.. Fix is now in
> place and has been tested with
> ZCU102-A53 / IPv6 on a TAP interface. Works well..
Hi Bilal,
The fix looks right to me but I have a few comments.
* Your patch seems a little wrongly formated.
[PATCH] goes into the Subject line for example and you're missing path prefixes.
Do a git log -- hw/net/cadence_gem.c to see examples on how it should look.
* The patch will probably not pass checkpatch since you seem to have long lines.
* We also need to update gem_receive_updatestats() to use the corrected macros.
More inline:
>
> Signed-off-by: Bilal Wasim <bilal_wa...@mentor.com>
> ---
> hw/net/cadence_gem.c | 18 ++++++++++++------
> 1 file changed, 12 insertions(+), 6 deletions(-)
>
> diff --git a/hw/net/cadence_gem.c b/hw/net/cadence_gem.c index
> b8be73d..f8bcbb3 100644
> --- a/hw/net/cadence_gem.c
> +++ b/hw/net/cadence_gem.c
> @@ -315,6 +315,12 @@
> #define GEM_MODID_VALUE 0x00020118
> +/* IEEE has specified that the most significant bit of the most
> +significant byte be used for
> + * distinguishing between Unicast and Multicast addresses.
> + * If its a 1, that means multicast, 0 means unicast. */
> +#define IS_MULTICAST(address) (((address[0] & 0x01) == 0x01) ? 1 :
> 0)
This can be simplified:
#define IS_MULTICAST(address) (address[0] & 1)
Actually, looking closer, we already have functions to do these checks in:
include/net/eth.h
static inline int is_multicast_ether_addr(const uint8_t *addr) static inline
int is_broadcast_ether_addr(const uint8_t *addr) static inline int
is_unicast_ether_addr(const uint8_t *addr)
> +#define IS_UNICAST(address) (!IS_MULTICAST(address))
> +
> static inline uint64_t tx_desc_get_buffer(CadenceGEMState *s, uint32_t
> *desc) {
> uint64_t ret = desc[0];
> @@ -690,21 +696,21 @@ static int gem_mac_address_filter(CadenceGEMState *s,
> const uint8_t *packet)
> }
> /* Accept packets -w- hash match? */
> - if ((packet[0] == 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_MCAST_HASH)) ||
> - (packet[0] != 0x01 && (s->regs[GEM_NWCFG] & GEM_NWCFG_UCAST_HASH))) {
> + if ((IS_MULTICAST(packet) && (s->regs[GEM_NWCFG] &
> GEM_NWCFG_MCAST_HASH)) ||
> + (IS_UNICAST(packet) && (s->regs[GEM_NWCFG] &
> GEM_NWCFG_UCAST_HASH))) {
> unsigned hash_index;
> hash_index = calc_mac_hash(packet);
> if (hash_index < 32) {
> if (s->regs[GEM_HASHLO] & (1<<hash_index)) {
> - return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
> - GEM_RX_UNICAST_HASH_ACCEPT;
> + return IS_MULTICAST(packet) ? GEM_RX_MULTICAST_HASH_ACCEPT :
> +
> + GEM_RX_UNICAST_HASH_ACCEPT;
> }
> } else {
> hash_index -= 32;
> if (s->regs[GEM_HASHHI] & (1<<hash_index)) {
> - return packet[0] == 0x01 ? GEM_RX_MULTICAST_HASH_ACCEPT :
> - GEM_RX_UNICAST_HASH_ACCEPT;
> + return IS_MULTICAST(packet) ? GEM_RX_MULTICAST_HASH_ACCEPT :
> +
> + GEM_RX_UNICAST_HASH_ACCEPT;
> }
> }
> }
> --
> 2.9.3
>
