Module Name: src Committed By: christos Date: Tue Mar 9 13:48:16 UTC 2021
Modified Files: src/sys/netinet: tcp_subr.c Log Message: Move the offset addition in one place and mask the random generated value to make sure that the isn is monotonic. To generate a diff of this commit: cvs rdiff -u -r1.287 -r1.288 src/sys/netinet/tcp_subr.c Please note that diffs are not public domain; they are subject to the copyright notices on the relevant files.
Modified files: Index: src/sys/netinet/tcp_subr.c diff -u src/sys/netinet/tcp_subr.c:1.287 src/sys/netinet/tcp_subr.c:1.288 --- src/sys/netinet/tcp_subr.c:1.287 Mon Mar 8 13:17:27 2021 +++ src/sys/netinet/tcp_subr.c Tue Mar 9 08:48:16 2021 @@ -1,4 +1,4 @@ -/* $NetBSD: tcp_subr.c,v 1.287 2021/03/08 18:17:27 christos Exp $ */ +/* $NetBSD: tcp_subr.c,v 1.288 2021/03/09 13:48:16 christos Exp $ */ /* * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project. @@ -91,7 +91,7 @@ */ #include <sys/cdefs.h> -__KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.287 2021/03/08 18:17:27 christos Exp $"); +__KERNEL_RCSID(0, "$NetBSD: tcp_subr.c,v 1.288 2021/03/09 13:48:16 christos Exp $"); #ifdef _KERNEL_OPT #include "opt_inet.h" @@ -2210,23 +2210,23 @@ tcp_new_iss1(void *laddr, void *faddr, u #ifdef TCPISS_DEBUG printf("ISS hash 0x%08x, ", tcp_iss); #endif - /* - * Add the offset in to the computed value. - */ - tcp_iss += tcp_iss_seq; -#ifdef TCPISS_DEBUG - printf("ISS %08x\n", tcp_iss); -#endif } else { /* * Randomize. */ - tcp_iss = cprng_fast32(); + tcp_iss = cprng_fast32() & TCP_ISS_RANDOM_MASK; #ifdef TCPISS_DEBUG printf("ISS random 0x%08x, ", tcp_iss); #endif } + /* + * Add the offset in to the computed value. + */ + tcp_iss += tcp_iss_seq; +#ifdef TCPISS_DEBUG + printf("ISS %08x\n", tcp_iss); +#endif return tcp_iss; }