@@ -307,85 +307,27 @@ static inline __u16 sctp_data_size(struct sctp_chunk *chunk)
}
/* Compare two TSNs */
+#define TSN_lt(a,b) \
+ (typecheck(__u32, a) && \
+ typecheck(__u32, b) && \
+ ((__s32)((a) - (b)) < 0))
-/* RFC 1982 - Serial Number Arithmetic
- *
- * 2. Comparison
- * Then, s1 is said to be equal to s2 if and only if i1 is equal to i2,
- * in all other cases, s1 is not equal to s2.
- *
- * s1 is said to be less than s2 if, and only if, s1 is not equal to s2,
- * and
- *
- * (i1 < i2 and i2 - i1 < 2^(SERIAL_BITS - 1)) or
- * (i1 > i2 and i1 - i2 > 2^(SERIAL_BITS - 1))
- *
- * s1 is said to be greater than s2 if, and only if, s1 is not equal to
- * s2, and
- *
- * (i1 < i2 and i2 - i1 > 2^(SERIAL_BITS - 1)) or
- * (i1 > i2 and i1 - i2 < 2^(SERIAL_BITS - 1))
- */
-
-/*
- * RFC 2960
- * 1.6 Serial Number Arithmetic
- *
- * Comparisons and arithmetic on TSNs in this document SHOULD use Serial
- * Number Arithmetic as defined in [RFC1982] where SERIAL_BITS = 32.
- */
-
-enum {
- TSN_SIGN_BIT = (1<<31)
-};
-
-static inline int TSN_lt(__u32 s, __u32 t)
-{
- return ((s) - (t)) & TSN_SIGN_BIT;
-}
-
-static inline int TSN_lte(__u32 s, __u32 t)
-{
- return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT);
-}
+#define TSN_lte(a,b) \
+ (typecheck(__u32, a) && \
+ typecheck(__u32, b) && \
+ ((__s32)((a) - (b)) <= 0))
/* Compare two SSNs */
-
-/*
- * RFC 2960
- * 1.6 Serial Number Arithmetic
- *
- * Comparisons and arithmetic on Stream Sequence Numbers in this document
- * SHOULD use Serial Number Arithmetic as defined in [RFC1982] where
- * SERIAL_BITS = 16.
- */
-enum {
- SSN_SIGN_BIT = (1<<15)
-};
-
-static inline int SSN_lt(__u16 s, __u16 t)
-{
- return ((s) - (t)) & SSN_SIGN_BIT;
-}
-
-static inline int SSN_lte(__u16 s, __u16 t)
-{
- return ((s) == (t)) || (((s) - (t)) & SSN_SIGN_BIT);
-}
-
-/*
- * ADDIP 3.1.1
- * The valid range of Serial Number is from 0 to 4294967295 (2**32 - 1). Serial
- * Numbers wrap back to 0 after reaching 4294967295.
- */
-enum {
- ADDIP_SERIAL_SIGN_BIT = (1<<31)
-};
-
-static inline int ADDIP_SERIAL_gte(__u32 s, __u32 t)
-{
- return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT);
-}
+#define SSN_lt(a,b) \
+ (typecheck(__u16, a) && \
+ typecheck(__u16, b) && \
+ ((__s16)((a) - (b)) < 0))
+
+/* ADDIP 3.1.1 */
+#define ADDIP_SERIAL_gte(a,b) \
+ (typecheck(__u32, a) && \
+ typecheck(__u32, b) && \
+ ((__s32)((b) - (a)) <= 0))
/* Check VTAG of the packet matches the sender's own tag. */
static inline int
Make it similar to time_before() macros: - easier to understand - make use of typecheck() to avoid working on unexpected variable types (made the issue on previous patch visible) - for _[lg]te versions, slighly faster, as the compiler used to generate a sequence of cmp/je/cmp/js instructions and now it's sub/test/jle (for _lte): Before, for sctp_outq_sack: if (primary->cacc.changeover_active) { 1f01: 80 b9 84 02 00 00 00 cmpb $0x0,0x284(%rcx) 1f08: 74 6e je 1f78 <sctp_outq_sack+0xe8> u8 clear_cycling = 0; if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { 1f0a: 8b 81 80 02 00 00 mov 0x280(%rcx),%eax return ((s) - (t)) & TSN_SIGN_BIT; } static inline int TSN_lte(__u32 s, __u32 t) { return ((s) == (t)) || (((s) - (t)) & TSN_SIGN_BIT); 1f10: 8b 7d bc mov -0x44(%rbp),%edi 1f13: 39 c7 cmp %eax,%edi 1f15: 74 25 je 1f3c <sctp_outq_sack+0xac> 1f17: 39 f8 cmp %edi,%eax 1f19: 78 21 js 1f3c <sctp_outq_sack+0xac> primary->cacc.changeover_active = 0; After: if (primary->cacc.changeover_active) { 1ee7: 80 b9 84 02 00 00 00 cmpb $0x0,0x284(%rcx) 1eee: 74 73 je 1f63 <sctp_outq_sack+0xf3> u8 clear_cycling = 0; if (TSN_lte(primary->cacc.next_tsn_at_change, sack_ctsn)) { 1ef0: 8b 81 80 02 00 00 mov 0x280(%rcx),%eax 1ef6: 2b 45 b4 sub -0x4c(%rbp),%eax 1ef9: 85 c0 test %eax,%eax 1efb: 7e 26 jle 1f23 <sctp_outq_sack+0xb3> primary->cacc.changeover_active = 0; *_lt() generated pretty much the same code. Tested with gcc (GCC) 6.1.1 20160621. This patch also removes SSN_lte as it is not used and cleanups some comments. Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> --- include/net/sctp/sm.h | 94 ++++++++++----------------------------------------- 1 file changed, 18 insertions(+), 76 deletions(-)