From 883ca833e5fb814fb03426c9d35e5489ce43e8da Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Fri, 16 Jan 2009 23:36:32 +0000 Subject: 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 Acked-by: Ian McDonald Signed-off-by: David S. Miller --- net/dccp/feat.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'net/dccp/feat.c') 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); -- cgit v1.2.3