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dccp: Increase the scope of variable-length htonl/ntohl functions

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This extends the scope of two available functions,
encode|decode_value_var, to work up to 6 (8) bytes, to match maximum
requirements in the RFC.

These functions are going to be used both by general option processing
and feature negotiation code, hence declarations have been put into
feat.h.

Signed-off-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Acked-by: Ian McDonald <ian.mcdonald@jandi.co.nz>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gerrit Renker 2008-11-23 16:07:53 -08:00 committed by David S. Miller
parent 71c262a3dd
commit 02fa460ef5
2 changed files with 28 additions and 7 deletions
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14
net/dccp/feat.h
View File

@ -125,4 +125,18 @@ extern int dccp_feat_clone(struct sock *oldsk, struct sock *newsk);
extern int dccp_feat_clone_list(struct list_head const *, struct list_head *); extern int dccp_feat_clone_list(struct list_head const *, struct list_head *);
extern int dccp_feat_init(struct sock *sk); extern int dccp_feat_init(struct sock *sk);
/*
* Encoding variable-length options and their maximum length.
*
* This affects NN options (SP options are all u8) and other variable-length
* options (see table 3 in RFC 4340). The limit is currently given the Sequence
* Window NN value (sec. 7.5.2) and the NDP count (sec. 7.7) option, all other
* options consume less than 6 bytes (timestamps are 4 bytes).
* When updating this constant (e.g. due to new internet drafts / RFCs), make
* sure that you also update all code which refers to it.
*/
#define DCCP_OPTVAL_MAXLEN 6
extern void dccp_encode_value_var(const u64 value, u8 *to, const u8 len);
extern u64 dccp_decode_value_var(const u8 *bf, const u8 len);
#endif /* _DCCP_FEAT_H */ #endif /* _DCCP_FEAT_H */

21
net/dccp/options.c
View File

@ -29,16 +29,20 @@ int sysctl_dccp_feat_tx_ccid = DCCPF_INITIAL_CCID;
int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR; int sysctl_dccp_feat_send_ack_vector = DCCPF_INITIAL_SEND_ACK_VECTOR;
int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT; int sysctl_dccp_feat_send_ndp_count = DCCPF_INITIAL_SEND_NDP_COUNT;
static u32 dccp_decode_value_var(const unsigned char *bf, const u8 len) u64 dccp_decode_value_var(const u8 *bf, const u8 len)
{ {
u32 value = 0; u64 value = 0;
if (len >= DCCP_OPTVAL_MAXLEN)
value += ((u64)*bf++) << 40;
if (len > 4)
value += ((u64)*bf++) << 32;
if (len > 3) if (len > 3)
value += *bf++ << 24; value += ((u64)*bf++) << 24;
if (len > 2) if (len > 2)
value += *bf++ << 16; value += ((u64)*bf++) << 16;
if (len > 1) if (len > 1)
value += *bf++ << 8; value += ((u64)*bf++) << 8;
if (len > 0) if (len > 0)
value += *bf; value += *bf;
@ -298,9 +302,12 @@ out_invalid_option:
EXPORT_SYMBOL_GPL(dccp_parse_options); EXPORT_SYMBOL_GPL(dccp_parse_options);
static void dccp_encode_value_var(const u32 value, unsigned char *to, void dccp_encode_value_var(const u64 value, u8 *to, const u8 len)
const unsigned int len)
{ {
if (len >= DCCP_OPTVAL_MAXLEN)
*to++ = (value & 0xFF0000000000ull) >> 40;
if (len > 4)
*to++ = (value & 0xFF00000000ull) >> 32;
if (len > 3) if (len > 3)
*to++ = (value & 0xFF000000) >> 24; *to++ = (value & 0xFF000000) >> 24;
if (len > 2) if (len > 2)