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authorGerrit Renker <gerrit@erg.abdn.ac.uk>2009-01-17 00:36:32 +0100
committerDavid S. Miller <davem@davemloft.net>2009-01-21 23:34:05 +0100
commit883ca833e5fb814fb03426c9d35e5489ce43e8da (patch)
treedcf361291b79e57195f8d89ca493c15c835b14cf /net
parentdccp: Implement both feature-local and feature-remote Sequence Window feature (diff)
downloadlinux-883ca833e5fb814fb03426c9d35e5489ce43e8da.tar.xz
linux-883ca833e5fb814fb03426c9d35e5489ce43e8da.zip
dccp: Initialisation and type-checking of feature sysctls
This patch takes care of initialising and type-checking sysctls related to feature negotiation. Type checking is important since some of the sysctls now directly impact the feature-negotiation process. The sysctls are initialised with the known default values for each feature. For the type-checking the value constraints from RFC 4340 are used: * Sequence Window uses the specified Wmin=32, the maximum is ulong (4 bytes), tested and confirmed that it works up to 4294967295 - for Gbps speed; * Ack Ratio is between 0 .. 0xffff (2-byte unsigned integer); * CCIDs are between 0 .. 255; * request_retries, retries1, retries2 also between 0..255 for good measure; * tx_qlen is checked to be non-negative; * sync_ratelimit remains as before. Notes: ------ 1. Die s@sysctl_dccp_feat@sysctl_dccp@g since the sysctls are now in feat.c. 2. As pointed out by Arnaldo, the pattern of type-checking repeats itself in other places, sometimes with exactly the same kind of definitions (e.g. "static int zero;"). It may be a good idea (kernel janitors?) to consolidate type checking. For the sake of keeping the changeset small and in order not to affect other subsystems, I have not strived to generalise here. Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk> Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
-rw-r--r--net/dccp/dccp.h3
-rw-r--r--net/dccp/feat.c11
-rw-r--r--net/dccp/feat.h8
-rw-r--r--net/dccp/options.c4
-rw-r--r--net/dccp/sysctl.c43
5 files changed, 46 insertions, 23 deletions
diff --git a/net/dccp/dccp.h b/net/dccp/dccp.h
index 04ae91898a68..44a5bc6f6785 100644
--- a/net/dccp/dccp.h
+++ b/net/dccp/dccp.h
@@ -95,9 +95,6 @@ extern void dccp_time_wait(struct sock *sk, int state, int timeo);
extern int sysctl_dccp_request_retries;
extern int sysctl_dccp_retries1;
extern int sysctl_dccp_retries2;
-extern int sysctl_dccp_feat_sequence_window;
-extern int sysctl_dccp_feat_rx_ccid;
-extern int sysctl_dccp_feat_tx_ccid;
extern int sysctl_dccp_tx_qlen;
extern int sysctl_dccp_sync_ratelimit;
diff --git a/net/dccp/feat.c b/net/dccp/feat.c
index 7303f79705d2..12006e9b2472 100644
--- a/net/dccp/feat.c
+++ b/net/dccp/feat.c
@@ -25,6 +25,11 @@
#include "ccid.h"
#include "feat.h"
+/* feature-specific sysctls - initialised to the defaults from RFC 4340, 6.4 */
+unsigned long sysctl_dccp_sequence_window __read_mostly = 100;
+int sysctl_dccp_rx_ccid __read_mostly = 2,
+ sysctl_dccp_tx_ccid __read_mostly = 2;
+
/*
* Feature activation handlers.
*
@@ -1146,7 +1151,7 @@ int dccp_feat_init(struct sock *sk)
/* Non-negotiable (NN) features */
rc = __feat_register_nn(fn, DCCPF_SEQUENCE_WINDOW, 0,
- sysctl_dccp_feat_sequence_window);
+ sysctl_dccp_sequence_window);
if (rc)
return rc;
@@ -1172,8 +1177,8 @@ int dccp_feat_init(struct sock *sk)
ccid_get_builtin_ccids(&rx.val, &rx.len))
return -ENOBUFS;
- if (!dccp_feat_prefer(sysctl_dccp_feat_tx_ccid, tx.val, tx.len) ||
- !dccp_feat_prefer(sysctl_dccp_feat_rx_ccid, rx.val, rx.len))
+ if (!dccp_feat_prefer(sysctl_dccp_tx_ccid, tx.val, tx.len) ||
+ !dccp_feat_prefer(sysctl_dccp_rx_ccid, rx.val, rx.len))
goto free_ccid_lists;
rc = __feat_register_sp(fn, DCCPF_CCID, true, false, tx.val, tx.len);
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
index 5e7b8481cd04..40aa7a10bd5f 100644
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -100,6 +100,13 @@ struct ccid_dependency {
u8 val;
};
+/*
+ * Sysctls to seed defaults for feature negotiation
+ */
+extern unsigned long sysctl_dccp_sequence_window;
+extern int sysctl_dccp_rx_ccid;
+extern int sysctl_dccp_tx_ccid;
+
#ifdef CONFIG_IP_DCCP_DEBUG
extern const char *dccp_feat_typename(const u8 type);
extern const char *dccp_feat_name(const u8 feat);
@@ -114,6 +121,7 @@ static inline void dccp_feat_debug(const u8 type, const u8 feat, const u8 val)
#endif /* CONFIG_IP_DCCP_DEBUG */
extern int dccp_feat_init(struct sock *sk);
+extern void dccp_feat_initialise_sysctls(void);
extern int dccp_feat_register_sp(struct sock *sk, u8 feat, u8 is_local,
u8 const *list, u8 len);
extern int dccp_feat_register_nn(struct sock *sk, u8 feat, u64 val);
diff --git a/net/dccp/options.c b/net/dccp/options.c
index 7b1165c21f51..3e2726c7182d 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -23,10 +23,6 @@
#include "dccp.h"
#include "feat.h"
-int sysctl_dccp_feat_sequence_window = DCCPF_INITIAL_SEQUENCE_WINDOW;
-int sysctl_dccp_feat_rx_ccid = DCCPF_INITIAL_CCID;
-int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
-
u64 dccp_decode_value_var(const u8 *bf, const u8 len)
{
u64 value = 0;
diff --git a/net/dccp/sysctl.c b/net/dccp/sysctl.c
index 018e210875e1..a5a1856234e7 100644
--- a/net/dccp/sysctl.c
+++ b/net/dccp/sysctl.c
@@ -18,55 +18,72 @@
#error This file should not be compiled without CONFIG_SYSCTL defined
#endif
+/* Boundary values */
+static int zero = 0,
+ u8_max = 0xFF;
+static unsigned long seqw_min = 32;
+
static struct ctl_table dccp_default_table[] = {
{
.procname = "seq_window",
- .data = &sysctl_dccp_feat_sequence_window,
- .maxlen = sizeof(sysctl_dccp_feat_sequence_window),
+ .data = &sysctl_dccp_sequence_window,
+ .maxlen = sizeof(sysctl_dccp_sequence_window),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_doulongvec_minmax,
+ .extra1 = &seqw_min, /* RFC 4340, 7.5.2 */
},
{
.procname = "rx_ccid",
- .data = &sysctl_dccp_feat_rx_ccid,
- .maxlen = sizeof(sysctl_dccp_feat_rx_ccid),
+ .data = &sysctl_dccp_rx_ccid,
+ .maxlen = sizeof(sysctl_dccp_rx_ccid),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &u8_max, /* RFC 4340, 10. */
},
{
.procname = "tx_ccid",
- .data = &sysctl_dccp_feat_tx_ccid,
- .maxlen = sizeof(sysctl_dccp_feat_tx_ccid),
+ .data = &sysctl_dccp_tx_ccid,
+ .maxlen = sizeof(sysctl_dccp_tx_ccid),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &u8_max, /* RFC 4340, 10. */
},
{
.procname = "request_retries",
.data = &sysctl_dccp_request_retries,
.maxlen = sizeof(sysctl_dccp_request_retries),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &u8_max,
},
{
.procname = "retries1",
.data = &sysctl_dccp_retries1,
.maxlen = sizeof(sysctl_dccp_retries1),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &u8_max,
},
{
.procname = "retries2",
.data = &sysctl_dccp_retries2,
.maxlen = sizeof(sysctl_dccp_retries2),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
+ .extra2 = &u8_max,
},
{
.procname = "tx_qlen",
.data = &sysctl_dccp_tx_qlen,
.maxlen = sizeof(sysctl_dccp_tx_qlen),
.mode = 0644,
- .proc_handler = proc_dointvec,
+ .proc_handler = proc_dointvec_minmax,
+ .extra1 = &zero,
},
{
.procname = "sync_ratelimit",