diff options
Diffstat (limited to 'Documentation/networking')
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 6 | ||||
| -rw-r--r-- | Documentation/networking/tc-actions-env-rules.txt | 29 |
2 files changed, 32 insertions, 3 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 747a5d15d52..6f7872ba1de 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -184,14 +184,14 @@ tcp_frto - INTEGER F-RTO is an enhanced recovery algorithm for TCP retransmission timeouts. It is particularly beneficial in wireless environments where packet loss is typically due to random radio interference - rather than intermediate router congestion. FRTO is sender-side + rather than intermediate router congestion. F-RTO is sender-side only modification. Therefore it does not require any support from the peer, but in a typical case, however, where wireless link is the local access link and most of the data flows downlink, the - faraway servers should have FRTO enabled to take advantage of it. + faraway servers should have F-RTO enabled to take advantage of it. If set to 1, basic version is enabled. 2 enables SACK enhanced F-RTO if flow uses SACK. The basic version can be used also when - SACK is in use though scenario(s) with it exists where FRTO + SACK is in use though scenario(s) with it exists where F-RTO interacts badly with the packet counting of the SACK enabled TCP flow. diff --git a/Documentation/networking/tc-actions-env-rules.txt b/Documentation/networking/tc-actions-env-rules.txt new file mode 100644 index 00000000000..01e716d185f --- /dev/null +++ b/Documentation/networking/tc-actions-env-rules.txt @@ -0,0 +1,29 @@ + +The "enviromental" rules for authors of any new tc actions are: + +1) If you stealeth or borroweth any packet thou shalt be branching +from the righteous path and thou shalt cloneth. + +For example if your action queues a packet to be processed later +or intentionaly branches by redirecting a packet then you need to +clone the packet. +There are certain fields in the skb tc_verd that need to be reset so we +avoid loops etc. A few are generic enough so much so that skb_act_clone() +resets them for you. So invoke skb_act_clone() rather than skb_clone() + +2) If you munge any packet thou shalt call pskb_expand_head in the case +someone else is referencing the skb. After that you "own" the skb. +You must also tell us if it is ok to munge the packet (TC_OK2MUNGE), +this way any action downstream can stomp on the packet. + +3) dropping packets you dont own is a nono. You simply return +TC_ACT_SHOT to the caller and they will drop it. + +The "enviromental" rules for callers of actions (qdiscs etc) are: + +*) thou art responsible for freeing anything returned as being +TC_ACT_SHOT/STOLEN/QUEUED. If none of TC_ACT_SHOT/STOLEN/QUEUED is +returned then all is great and you dont need to do anything. + +Post on netdev if something is unclear. + |