diff options
author | Jesse Brandeburg <jesse.brandeburg@intel.com> | 2008-02-21 15:11:02 -0800 |
---|---|---|
committer | Jeff Garzik <jeff@garzik.org> | 2008-02-24 00:07:49 -0500 |
commit | de92d84ec2305c490aa1db33f6e40680f8c236a8 (patch) | |
tree | 78298ae28581b04642313f1d78c968d1e53573e5 /drivers | |
parent | 4a5694e66428607585c9f4dd14bcf4158d2de191 (diff) | |
download | blackbird-op-linux-de92d84ec2305c490aa1db33f6e40680f8c236a8.tar.gz blackbird-op-linux-de92d84ec2305c490aa1db33f6e40680f8c236a8.zip |
e1000e: fix flow control denial of service possibility
this patch avoids a denial of service from an evildoer sending a
continuous stream of flow control at our adapter that is plugged
into a non-flow control enabled switch.
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/net/e1000e/lib.c | 31 |
1 files changed, 5 insertions, 26 deletions
diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c index 0860b5fb3471..341d74e81fb0 100644 --- a/drivers/net/e1000e/lib.c +++ b/drivers/net/e1000e/lib.c @@ -1104,34 +1104,13 @@ s32 e1000e_config_fc_after_link_up(struct e1000_hw *hw) (mii_nway_lp_ability_reg & NWAY_LPAR_ASM_DIR)) { mac->fc = e1000_fc_rx_pause; hw_dbg(hw, "Flow Control = RX PAUSE frames only.\r\n"); - } - /* Per the IEEE spec, at this point flow control should be - * disabled. However, we want to consider that we could - * be connected to a legacy switch that doesn't advertise - * desired flow control, but can be forced on the link - * partner. So if we advertised no flow control, that is - * what we will resolve to. If we advertised some kind of - * receive capability (Rx Pause Only or Full Flow Control) - * and the link partner advertised none, we will configure - * ourselves to enable Rx Flow Control only. We can do - * this safely for two reasons: If the link partner really - * didn't want flow control enabled, and we enable Rx, no - * harm done since we won't be receiving any PAUSE frames - * anyway. If the intent on the link partner was to have - * flow control enabled, then by us enabling RX only, we - * can at least receive pause frames and process them. - * This is a good idea because in most cases, since we are - * predominantly a server NIC, more times than not we will - * be asked to delay transmission of packets than asking - * our link partner to pause transmission of frames. - */ - else if ((mac->original_fc == e1000_fc_none) || - (mac->original_fc == e1000_fc_tx_pause)) { + } else { + /* + * Per the IEEE spec, at this point flow control + * should be disabled. + */ mac->fc = e1000_fc_none; hw_dbg(hw, "Flow Control = NONE.\r\n"); - } else { - mac->fc = e1000_fc_rx_pause; - hw_dbg(hw, "Flow Control = RX PAUSE frames only.\r\n"); } /* Now we need to do one last check... If we auto- |