leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity

dccp: Initialisation and type-checking of feature sysctls

Browse Source 
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>
This commit is contained in:
Gerrit Renker 2009-01-16 23:36:32 +00:00 committed by David S. Miller
parent 792b48780e
commit 883ca833e5
6 changed files with 46 additions and 31 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
include/linux/dccp.h
View File

@ -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

3
net/dccp/dccp.h
View File

@ -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;

11
net/dccp/feat.c
View File

@ -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);

8
net/dccp/feat.h
View File

@ -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);

4
net/dccp/options.c
View File

@ -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;

43
net/dccp/sysctl.c
View File

@ -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",