From 02fa460ef553faabc7e0b15ff9f607f028739808 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Sun, 23 Nov 2008 16:07:53 -0800 Subject: [PATCH] dccp: Increase the scope of variable-length htonl/ntohl functions 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 Acked-by: Ian McDonald Acked-by: Arnaldo Carvalho de Melo Signed-off-by: David S. Miller --- net/dccp/feat.h | 14 ++++++++++++++ net/dccp/options.c | 21 ++++++++++++++------- 2 files changed, 28 insertions(+), 7 deletions(-) diff --git a/net/dccp/feat.h b/net/dccp/feat.h index 093af1610d1..a8ab9e1e8b1 100644 --- a/net/dccp/feat.h +++ b/net/dccp/feat.h @@ -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_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 */ diff --git a/net/dccp/options.c b/net/dccp/options.c index 515ad45013a..9cb0ff89405 100644 --- a/net/dccp/options.c +++ b/net/dccp/options.c @@ -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_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) - value += *bf++ << 24; + value += ((u64)*bf++) << 24; if (len > 2) - value += *bf++ << 16; + value += ((u64)*bf++) << 16; if (len > 1) - value += *bf++ << 8; + value += ((u64)*bf++) << 8; if (len > 0) value += *bf; @@ -298,9 +302,12 @@ out_invalid_option: EXPORT_SYMBOL_GPL(dccp_parse_options); -static void dccp_encode_value_var(const u32 value, unsigned char *to, - const unsigned int len) +void dccp_encode_value_var(const u64 value, u8 *to, const u8 len) { + if (len >= DCCP_OPTVAL_MAXLEN) + *to++ = (value & 0xFF0000000000ull) >> 40; + if (len > 4) + *to++ = (value & 0xFF00000000ull) >> 32; if (len > 3) *to++ = (value & 0xFF000000) >> 24; if (len > 2) -- 2.39.5