Adds Kconfig-entries, modified Makefile, and adds DCCP_CCID enum for for
CCID 4. Kconfig-entries are derived from CCID 3, and are probably
invalid.
Signed-off-by: Tommi Saviranta <wnd@xxxxxx>
---
diff --git a/include/linux/dccp.h b/include/linux/dccp.h
index b569947..dc19d6b 100644
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -173,6 +173,7 @@ enum {
enum {
DCCPC_CCID2 = 2,
DCCPC_CCID3 = 3,
+ DCCPC_CCID4 = 4,
};
/* DCCP features (RFC 4340 section 6.4) */
diff --git a/net/dccp/ccids/Kconfig b/net/dccp/ccids/Kconfig
index a0c42d7..e402869 100644
--- a/net/dccp/ccids/Kconfig
+++ b/net/dccp/ccids/Kconfig
@@ -115,4 +115,87 @@ config IP_DCCP_TFRC_DEBUG
bool
default y if IP_DCCP_CCID3_DEBUG
+config IP_DCCP_CCID4
+ tristate "CCID4 (TCP-Friendly, Small Packet Variant) (EXPERIMENTAL)"
+ depends on IP_DCCP
+ def_tristate IP_DCCP
+ ---help---
+ CCID 4 denotes the Small-Packet variant of TCP-Friendly Rate Control
+ (TFRC-SP), an equation-based rate-controlled congestion control
+ mechanism. TFRC-SP is designed to be reasonably fair when competing
+ for bandwidth with TCP-like flows, where a flow is "reasonably fair"
+ if its sending rate is generally within a factor of two of the
+ sending rate of a TCP flow under the same conditions. However,
+ TFRC-SP has a much lower variation of throughput over time compared
+ with TCP, which makes CCID 4 more suitable than CCID 2 for
+ applications such streaming media where a relatively smooth sending
+ rate is of importance.
+
+ CCID 4 is further described in RFC xxxx,
+ http://www.ietf.org/rfc/rfcXXXX.txt
+
+ The TFRC-SP congestion control algorithms were initially described in
+ RFC 4828.
+
+ This text was extracted from RFC 4340 (sec. 10.2),
+ http://www.ietf.org/rfc/rfc4340.txt, and modified to match CCID4.
+
+ To compile this CCID as a module, choose M here: the module will be
+ called dccp_ccid4.
+
+ If in doubt, say M.
+
+config IP_DCCP_CCID4_DEBUG
+ bool "CCID4 debugging messages"
+ depends on IP_DCCP_CCID4
+ ---help---
+ Enable CCID4-specific debugging messages.
+
+ When compiling CCID4 as a module, this debugging output can
+ additionally be toggled by setting the ccid4_debug module
+ parameter to 0 or 1.
+
+ If in doubt, say N.
+
+config IP_DCCP_CCID4_RTO
+ int "Use higher bound for nofeedback timer"
+ default 100
+ depends on IP_DCCP_CCID4 && EXPERIMENTAL
+ ---help---
+ FIXME
+ Use higher lower bound for nofeedback timer expiration.
+
+ The TFRC-SP nofeedback timer normally expires after the maximum of 4
+ RTTs and twice the current send interval (RFC 3448, 4.3). On LANs
+ with a small RTT this can mean a high processing load and reduced
+ performance, since then the nofeedback timer is triggered very
+ frequently.
+
+ This option enables to set a higher lower bound for the nofeedback
+ value. Values in units of milliseconds can be set here.
+
+ A value of 0 disables this feature by enforcing the value specified
+ in RFC 3448. The following values have been suggested as bounds for
+ experimental use:
+ * 16-20ms to match the typical multimedia inter-frame interval
+ * 100ms as a reasonable compromise [default]
+ * 1000ms corresponds to the lower TCP RTO bound (RFC 2988, 2.4)
+
+ The default of 100ms is a compromise between a large value for
+ efficient DCCP implementations, and a small value to avoid disrupting
+ the network in times of congestion.
+
+ The purpose of the nofeedback timer is to slow DCCP down when there
+ is serious network congestion: experimenting with larger values should
+ therefore not be performed on WANs.
+
+# The TFRC-SP Library: currently only has CCID 4 as customer
+config IP_DCCP_TFRC_SP_LIB
+ depends on IP_DCCP_CCID4
+ def_tristate IP_DCCP_CCID4
+
+config IP_DCCP_TFRC_SP_DEBUG
+ bool
+ default y if IP_DCCP_CCID4_DEBUG
+
endmenu
diff --git a/net/dccp/ccids/Makefile b/net/dccp/ccids/Makefile
index 438f20b..fa21407 100644
--- a/net/dccp/ccids/Makefile
+++ b/net/dccp/ccids/Makefile
@@ -5,5 +5,9 @@ dccp_ccid3-y := ccid3.o
obj-$(CONFIG_IP_DCCP_CCID2) += dccp_ccid2.o
dccp_ccid2-y := ccid2.o
+
+obj-$(CONFIG_IP_DCCP_CCID4) += dccp_ccid4.o
+
+dccp_ccid4-y := ccid4.o
obj-y += lib/
-
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