netdev - [NET-NEXT PATCH 2/2] e1000: don't generate bad checksums for tcp packets with 0 csum

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Thu, 09 Oct 2008 09:58:52 -0700
From:	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To:	jeff@...zik.org, davem@...emloft.net
Cc:	netdev@...r.kernel.org, Dave Graham <david.graham@...el.com>,
	Jesse Brandeburg <jesse.brandeburg@...el.com>,
	Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [NET-NEXT PATCH 2/2] e1000: don't generate bad checksums for tcp
	packets with 0 csum

From: Dave Graham <david.graham@...el.com>

When offloading transmit checksums only, the driver was not
correctly configuring the hardware to handle the case of a zero
checksum.  For UDP the correct behavior is to leave it alone, but
for tcp the checksum must be changed from 0x0000 to 0xFFFF.  The
hardware takes care of this case but only if it is told the
packet is tcp.

same patch as e1000e

Signed-off-by: Dave Graham <david.graham@...el.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---

 drivers/net/e1000/e1000_main.c |   55 ++++++++++++++++++++++++++--------------
 1 files changed, 36 insertions(+), 19 deletions(-)

diff --git a/drivers/net/e1000/e1000_main.c b/drivers/net/e1000/e1000_main.c
index 2ab44db..3bafaed 100644
--- a/drivers/net/e1000/e1000_main.c
+++ b/drivers/net/e1000/e1000_main.c
@@ -2873,32 +2873,49 @@ static bool e1000_tx_csum(struct e1000_adapter *adapter,
 	struct e1000_buffer *buffer_info;
 	unsigned int i;
 	u8 css;
+	u32 cmd_len = E1000_TXD_CMD_DEXT;
 
-	if (likely(skb->ip_summed == CHECKSUM_PARTIAL)) {
-		css = skb_transport_offset(skb);
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		return false;
 
-		i = tx_ring->next_to_use;
-		buffer_info = &tx_ring->buffer_info[i];
-		context_desc = E1000_CONTEXT_DESC(*tx_ring, i);
+	switch (skb->protocol) {
+	case __constant_htons(ETH_P_IP):
+		if (ip_hdr(skb)->protocol == IPPROTO_TCP)
+			cmd_len |= E1000_TXD_CMD_TCP;
+		break;
+	case __constant_htons(ETH_P_IPV6):
+		/* XXX not handling all IPV6 headers */
+		if (ipv6_hdr(skb)->nexthdr == IPPROTO_TCP)
+			cmd_len |= E1000_TXD_CMD_TCP;
+		break;
+	default:
+		if (unlikely(net_ratelimit()))
+			DPRINTK(DRV, WARNING,
+			        "checksum_partial proto=%x!\n", skb->protocol);
+		break;
+	}
 
-		context_desc->lower_setup.ip_config = 0;
-		context_desc->upper_setup.tcp_fields.tucss = css;
-		context_desc->upper_setup.tcp_fields.tucso =
-			css + skb->csum_offset;
-		context_desc->upper_setup.tcp_fields.tucse = 0;
-		context_desc->tcp_seg_setup.data = 0;
-		context_desc->cmd_and_length = cpu_to_le32(E1000_TXD_CMD_DEXT);
+	css = skb_transport_offset(skb);
 
-		buffer_info->time_stamp = jiffies;
-		buffer_info->next_to_watch = i;
+	i = tx_ring->next_to_use;
+	buffer_info = &tx_ring->buffer_info[i];
+	context_desc = E1000_CONTEXT_DESC(*tx_ring, i);
 
-		if (unlikely(++i == tx_ring->count)) i = 0;
-		tx_ring->next_to_use = i;
+	context_desc->lower_setup.ip_config = 0;
+	context_desc->upper_setup.tcp_fields.tucss = css;
+	context_desc->upper_setup.tcp_fields.tucso =
+		css + skb->csum_offset;
+	context_desc->upper_setup.tcp_fields.tucse = 0;
+	context_desc->tcp_seg_setup.data = 0;
+	context_desc->cmd_and_length = cpu_to_le32(cmd_len);
 
-		return true;
-	}
+	buffer_info->time_stamp = jiffies;
+	buffer_info->next_to_watch = i;
 
-	return false;
+	if (unlikely(++i == tx_ring->count)) i = 0;
+	tx_ring->next_to_use = i;
+
+	return true;
 }
 
 #define E1000_MAX_TXD_PWR	12

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html