This patch is for the dccp test tree at
git://eden-feed.erg.abdn.ac.uk/dccp_exp [subtree 'dccp']
The actual 'module' is only 5 lines long.
>>>>>>>>>>>>>>>>>>>>> Patch <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
dccp: sample kernel module, NULL-CCID ("UDP-like")
This implements an experimental CCID which does not do any congestion control,
i.e. "UDP-like".
This is an experimental CCID. It is not meant for actual deployment, but
rather as sample kernel code, providing a worked example of how to add a
new CCID module.
Since CCID-0 is reserved (RFC 4340, table 5), this experimental NULL CCID uses
the first available experimental CCID, CCID-248 (RFC 4340, 19.5).
Signed-off-by: Gerrit Renker <gerrit@xxxxxxxxxxxxxx>
---
include/linux/dccp.h | 7 +++++++
net/dccp/Makefile | 1 +
net/dccp/ccid.c | 3 +++
net/dccp/ccid.h | 3 +++
net/dccp/ccids/Kconfig | 12 ++++++++++++
net/dccp/ccids/ccid0.c | 27 +++++++++++++++++++++++++++
net/dccp/feat.c | 17 ++++++++++++++++-
7 files changed, 69 insertions(+), 1 deletion(-)
--- a/include/linux/dccp.h
+++ b/include/linux/dccp.h
@@ -177,6 +177,13 @@ enum {
enum {
DCCPC_CCID2 = 2,
DCCPC_CCID3 = 3,
+ /*
+ * CCIDs 248-255 below are permanently reserved for
+ * experimental and testing use (RFC 4340, 19.5).
+ */
+#define DCCPC_TESTING_MIN 248
+#define DCCPC_TESTING_MAX 255
+ DCCPC_CCID_ZERO = DCCPC_TESTING_MIN,
};
/* DCCP features (RFC 4340 section 6.4) */
--- /dev/null
+++ b/net/dccp/ccids/ccid0.c
@@ -0,0 +1,27 @@
+/*
+ * CCID-ZERO - UDP-like congestion control
+ *
+ * This is a sample kernel module, used for testing and development, but not
+ * for actual deployment. The CCID number is taken from the range of CCIDs
+ * set apart for testing and experimenting.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include "../ccid.h"
+
+struct ccid_operations ccid0_ops = {
+ .ccid_id = DCCPC_CCID_ZERO,
+ .ccid_name = "UDP-like transport"
+};
--- a/net/dccp/ccid.c
+++ b/net/dccp/ccid.c
@@ -19,6 +19,9 @@ static struct ccid_operations *ccids[] =
#ifdef CONFIG_IP_DCCP_CCID3
&ccid3_ops,
#endif
+#ifdef CONFIG_IP_DCCP_CCID0
+ &ccid0_ops,
+#endif
};
static struct ccid_operations *ccid_by_number(const u8 id)
--- a/net/dccp/ccid.h
+++ b/net/dccp/ccid.h
@@ -91,6 +91,9 @@ struct ccid_operations {
int __user *optlen);
};
+#ifdef CONFIG_IP_DCCP_CCID0
+extern struct ccid_operations ccid0_ops;
+#endif
extern struct ccid_operations ccid2_ops;
#ifdef CONFIG_IP_DCCP_CCID3
extern struct ccid_operations ccid3_ops;
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -620,7 +620,8 @@ static u8 dccp_feat_is_valid_sp_val(u8 f
{
switch (feat_num) {
case DCCPF_CCID:
- return val == DCCPC_CCID2 || val == DCCPC_CCID3;
+ return val == DCCPC_CCID2 || val == DCCPC_CCID3 ||
+ (val >= DCCPC_TESTING_MIN && val <= DCCPC_TESTING_MAX);
/* Type-check Boolean feature values: */
case DCCPF_SHORT_SEQNOS:
case DCCPF_ECN_INCAPABLE:
@@ -831,6 +832,18 @@ EXPORT_SYMBOL_GPL(dccp_feat_signal_nn_ch
*/
static const struct ccid_dependency *dccp_feat_ccid_deps(u8 ccid, bool is_local)
{
+ static const struct ccid_dependency ccid0_dependencies[2][2] = {
+ /*
+ * The UDP-like CCID does not have special dependencies, but for
+ * testing dependencies (e.g. Ack Vectors) can be defined below.
+ */
+ {
+ { 0, 0, 0, 0 }
+ },
+ {
+ { 0, 0, 0, 0 }
+ }
+ };
static const struct ccid_dependency ccid2_dependencies[2][2] = {
/*
* CCID2 mandates Ack Vectors (RFC 4341, 4.): as CCID is a TX
@@ -916,6 +929,8 @@ static const struct ccid_dependency *dcc
}
};
switch (ccid) {
+ case DCCPC_CCID_ZERO:
+ return ccid0_dependencies[is_local];
case DCCPC_CCID2:
return ccid2_dependencies[is_local];
case DCCPC_CCID3:
--- a/net/dccp/ccids/Kconfig
+++ b/net/dccp/ccids/Kconfig
@@ -103,4 +103,16 @@ config IP_DCCP_TFRC_LIB
config IP_DCCP_TFRC_DEBUG
def_bool y if IP_DCCP_CCID3_DEBUG
+
+config IP_DCCP_CCID0
+ bool "CCID-ZERO (UDP-Like) sample kernel module"
+ def_bool n
+ ---help---
+ This is a sample kernel module to illustrate the integration of new
+ CCID kernel modules into CCID. It can also be used for performance
+ testing, but is not meant for deployment since it operates without
+ any congestion control. It is a NULL CCID, its identifier is 248.
+
+ Say N.
+
endmenu
--- a/net/dccp/Makefile
+++ b/net/dccp/Makefile
@@ -7,6 +7,7 @@ dccp-y := ccid.o feat.o input.o minisock
#
# CCID-2 is default (RFC 4340, p. 77) and has Ack Vectors as dependency
dccp-y += ccids/ccid2.o ackvec.o
+dccp-$(CONFIG_IP_DCCP_CCID0) += ccids/ccid0.o
dccp-$(CONFIG_IP_DCCP_CCID3) += ccids/ccid3.o
dccp-$(CONFIG_IP_DCCP_TFRC_LIB) += ccids/lib/tfrc.o \
ccids/lib/tfrc_equation.o \
--
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