From 883ca833e5fb814fb03426c9d35e5489ce43e8da Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Fri, 16 Jan 2009 23:36:32 +0000 Subject: [PATCH] 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 --- include/linux/dccp.h | 8 -------- net/dccp/dccp.h | 3 --- net/dccp/feat.c | 11 ++++++++--- net/dccp/feat.h | 8 ++++++++ net/dccp/options.c | 4 ---- net/dccp/sysctl.c | 43 ++++++++++++++++++++++++++++++------------- 6 files changed, 46 insertions(+), 31 deletions(-) diff --git a/include/linux/dccp.h b/include/linux/dccp.h index 7a0502ab383a..7434a8353e23 100644 --- a/include/linux/dccp.h +++ b/include/linux/dccp.h @@ -355,14 +355,6 @@ static inline unsigned int dccp_hdr_len(const struct sk_buff *skb) return __dccp_hdr_len(dccp_hdr(skb)); } - -/* initial values for each feature */ -#define DCCPF_INITIAL_SEQUENCE_WINDOW 100 -#define DCCPF_INITIAL_ACK_RATIO 2 -#define DCCPF_INITIAL_CCID DCCPC_CCID2 -/* FIXME: for now we're default to 1 but it should really be 0 */ -#define DCCPF_INITIAL_SEND_NDP_COUNT 1 - /** * struct dccp_request_sock - represent DCCP-specific connection request * @dreq_inet_rsk: structure inherited from 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", -- GitLab