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 <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>
diff --git a/net/dccp/feat.h b/net/dccp/feat.h
index 093af16..a8ab9e1 100644
--- a/net/dccp/feat.h
+++ b/net/dccp/feat.h
@@ -125,4 +125,18 @@
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 515ad45..9cb0ff8 100644
--- a/net/dccp/options.c
+++ b/net/dccp/options.c
@@ -29,16 +29,20 @@
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 @@
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)