On Thu, Jan 20, 2022 at 06:36:36PM -0700, Theo de Raadt wrote:
> > Alternatives are:
> > - put U to every TF_ TCP flag
> > - put U to all TF_TMR_ timer flags
> > - put U to TF_TMR_REXMT retransmit timer flag
> > - cast TF_TIMER to unsigned (what I did)
> > - cast to unsigned in the TCP_TIMER_ARM, TCP_TIMER_ARM_MSEC,
> > TCP_TIMER_DISARM, TCP_TIMER_ISARMED macros where the shift happens.
> >
> > There is no best, minimalistic and most consistent solution.
>
> I have always considered numberU as being the same type of thing as
> using 'u_int' instead of 'int' for a variable, it is idiomatic C
> to force all considerations into signed.
>
> If our system header files had 4000 lines with U, how many bugs
> would get fixed incidentaly?
>
> It is a strong idiom. A sad idiom, perhaps. It wasn't needed in
> historic C, a compiler would always generate the correct code, but
> here we are.
Sounds like a call for the huge U change.
ok?
bluhm
Index: netinet/tcp_var.h
===================================================================
RCS file: /data/mirror/openbsd/cvs/src/sys/netinet/tcp_var.h,v
retrieving revision 1.136
diff -u -p -r1.136 tcp_var.h
--- netinet/tcp_var.h 28 Jan 2021 14:53:20 -0000 1.136
+++ netinet/tcp_var.h 21 Jan 2022 15:29:14 -0000
@@ -77,33 +77,33 @@ struct tcpcb {
u_short t_maxseg; /* maximum segment size */
char t_force; /* 1 if forcing out a byte */
u_int t_flags;
-#define TF_ACKNOW 0x0001 /* ack peer immediately */
-#define TF_NODELAY 0x0004 /* don't delay packets to
coalesce */
-#define TF_NOOPT 0x0008 /* don't use tcp options */
-#define TF_SENTFIN 0x0010 /* have sent FIN */
-#define TF_REQ_SCALE 0x0020 /* have/will request window
scaling */
-#define TF_RCVD_SCALE 0x0040 /* other side has requested
scaling */
-#define TF_REQ_TSTMP 0x0080 /* have/will request timestamps
*/
-#define TF_RCVD_TSTMP 0x0100 /* a timestamp was received in
SYN */
-#define TF_SACK_PERMIT 0x0200 /* other side said I could SACK
*/
-#define TF_SIGNATURE 0x0400 /* require TCP MD5 signature */
+#define TF_ACKNOW 0x0001U /* ack peer immediately */
+#define TF_NODELAY 0x0004U /* don't delay packets to
coalesce */
+#define TF_NOOPT 0x0008U /* don't use tcp options */
+#define TF_SENTFIN 0x0010U /* have sent FIN */
+#define TF_REQ_SCALE 0x0020U /* have/will request window
scaling */
+#define TF_RCVD_SCALE 0x0040U /* other side has requested
scaling */
+#define TF_REQ_TSTMP 0x0080U /* have/will request timestamps
*/
+#define TF_RCVD_TSTMP 0x0100U /* a timestamp was received in
SYN */
+#define TF_SACK_PERMIT 0x0200U /* other side said I could SACK
*/
+#define TF_SIGNATURE 0x0400U /* require TCP MD5 signature */
#ifdef TCP_ECN
-#define TF_ECN_PERMIT 0x00008000 /* other side said I could ECN */
-#define TF_RCVD_CE 0x00010000 /* send ECE in subsequent segs */
-#define TF_SEND_CWR 0x00020000 /* send CWR in next seg */
-#define TF_DISABLE_ECN 0x00040000 /* disable ECN for this connection */
+#define TF_ECN_PERMIT 0x00008000U /* other side said I could ECN */
+#define TF_RCVD_CE 0x00010000U /* send ECE in subsequent segs */
+#define TF_SEND_CWR 0x00020000U /* send CWR in next seg */
+#define TF_DISABLE_ECN 0x00040000U /* disable ECN for this connection */
#endif
-#define TF_LASTIDLE 0x00100000 /* no outstanding ACK on last send */
-#define TF_PMTUD_PEND 0x00400000 /* Path MTU Discovery pending */
-#define TF_NEEDOUTPUT 0x00800000 /* call tcp_output after tcp_input */
-#define TF_BLOCKOUTPUT 0x01000000 /* avert tcp_output during tcp_input */
-#define TF_NOPUSH 0x02000000 /* don't push */
-#define TF_TMR_REXMT 0x04000000 /* retransmit timer armed */
-#define TF_TMR_PERSIST 0x08000000 /* retransmit persistence timer armed */
-#define TF_TMR_KEEP 0x10000000 /* keep alive timer armed */
-#define TF_TMR_2MSL 0x20000000 /* 2*msl quiet time timer armed */
-#define TF_TMR_REAPER 0x40000000 /* delayed cleanup timer armed, dead */
-#define TF_TMR_DELACK 0x80000000 /* delayed ack timer armed */
+#define TF_LASTIDLE 0x00100000U /* no outstanding ACK on last send */
+#define TF_PMTUD_PEND 0x00400000U /* Path MTU Discovery pending */
+#define TF_NEEDOUTPUT 0x00800000U /* call tcp_output after tcp_input */
+#define TF_BLOCKOUTPUT 0x01000000U /* avert tcp_output during tcp_input */
+#define TF_NOPUSH 0x02000000U /* don't push */
+#define TF_TMR_REXMT 0x04000000U /* retransmit timer armed */
+#define TF_TMR_PERSIST 0x08000000U /* retransmit persistence timer armed */
+#define TF_TMR_KEEP 0x10000000U /* keep alive timer armed */
+#define TF_TMR_2MSL 0x20000000U /* 2*msl quiet time timer armed */
+#define TF_TMR_REAPER 0x40000000U /* delayed cleanup timer armed, dead */
+#define TF_TMR_DELACK 0x80000000U /* delayed ack timer armed */
#define TF_TIMER TF_TMR_REXMT /* used to shift with TCPT values */
struct mbuf *t_template; /* skeletal packet for transmit */
