[src/trunk]: src/sys/netinet inet: reduce indents of a normal path to improve...

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/3b922dddbec0
branches:  trunk
changeset: 943161:3b922dddbec0
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Fri Aug 28 06:22:25 2020 +0000

description:
inet: reduce indents of a normal path to improve readability (NFCI)

diffstat:

 sys/netinet/ip_output.c |  99 ++++++++++++++++++++++++------------------------
 1 files changed, 49 insertions(+), 50 deletions(-)

diffs (142 lines):

diff -r a0eb6ae85958 -r 3b922dddbec0 sys/netinet/ip_output.c
--- a/sys/netinet/ip_output.c   Fri Aug 28 06:20:44 2020 +0000
+++ b/sys/netinet/ip_output.c   Fri Aug 28 06:22:25 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ip_output.c,v 1.316 2020/08/28 06:19:13 ozaki-r Exp $  */
+/*     $NetBSD: ip_output.c,v 1.317 2020/08/28 06:22:25 ozaki-r Exp $  */
 
 /*
  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
@@ -91,7 +91,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.316 2020/08/28 06:19:13 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_output.c,v 1.317 2020/08/28 06:22:25 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -252,6 +252,7 @@
        struct psref psref, psref_ia;
        int bound;
        bool bind_need_restore = false;
+       const struct sockaddr *sa;
 
        len = 0;
 
@@ -679,59 +680,59 @@
        }
        sw_csum = m->m_pkthdr.csum_flags & ~ifp->if_csum_flags_tx;
 
-       /*
-        * If small enough for mtu of path, or if using TCP segmentation
-        * offload, can just send directly.
-        */
-       if (ntohs(ip->ip_len) <= mtu ||
-           (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) != 0) {
-               const struct sockaddr *sa;
+       sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst);
+
+       /* Need to fragment the packet */
+       if (ntohs(ip->ip_len) > mtu &&
+           (m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) {
+               goto fragment;
+       }
 
 #if IFA_STATS
-               if (ia)
-                       ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len);
+       if (ia)
+               ia->ia_ifa.ifa_data.ifad_outbytes += ntohs(ip->ip_len);
 #endif
-               /*
-                * Always initialize the sum to 0!  Some HW assisted
-                * checksumming requires this.
-                */
-               ip->ip_sum = 0;
+       /*
+        * Always initialize the sum to 0!  Some HW assisted
+        * checksumming requires this.
+        */
+       ip->ip_sum = 0;
 
-               if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) {
-                       /*
-                        * Perform any checksums that the hardware can't do
-                        * for us.
-                        *
-                        * XXX Does any hardware require the {th,uh}_sum
-                        * XXX fields to be 0?
-                        */
-                       if (sw_csum & M_CSUM_IPv4) {
-                               KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4));
-                               ip->ip_sum = in_cksum(m, hlen);
-                               m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4;
+       if ((m->m_pkthdr.csum_flags & M_CSUM_TSOv4) == 0) {
+               /*
+                * Perform any checksums that the hardware can't do
+                * for us.
+                *
+                * XXX Does any hardware require the {th,uh}_sum
+                * XXX fields to be 0?
+                */
+               if (sw_csum & M_CSUM_IPv4) {
+                       KASSERT(IN_NEED_CHECKSUM(ifp, M_CSUM_IPv4));
+                       ip->ip_sum = in_cksum(m, hlen);
+                       m->m_pkthdr.csum_flags &= ~M_CSUM_IPv4;
+               }
+               if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
+                       if (IN_NEED_CHECKSUM(ifp,
+                           sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) {
+                               in_undefer_cksum_tcpudp(m);
                        }
-                       if (sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4)) {
-                               if (IN_NEED_CHECKSUM(ifp,
-                                   sw_csum & (M_CSUM_TCPv4|M_CSUM_UDPv4))) {
-                                       in_undefer_cksum_tcpudp(m);
-                               }
-                               m->m_pkthdr.csum_flags &=
-                                   ~(M_CSUM_TCPv4|M_CSUM_UDPv4);
-                       }
+                       m->m_pkthdr.csum_flags &=
+                           ~(M_CSUM_TCPv4|M_CSUM_UDPv4);
                }
-
-               sa = (m->m_flags & M_MCAST) ? sintocsa(rdst) : sintocsa(dst);
-               if (__predict_false(sw_csum & M_CSUM_TSOv4)) {
-                       /*
-                        * TSO4 is required by a packet, but disabled for
-                        * the interface.
-                        */
-                       error = ip_tso_output(ifp, m, sa, rt);
-               } else
-                       error = ip_if_output(ifp, m, sa, rt);
-               goto done;
        }
 
+       /* Send it */
+       if (__predict_false(sw_csum & M_CSUM_TSOv4)) {
+               /*
+                * TSO4 is required by a packet, but disabled for
+                * the interface.
+                */
+               error = ip_tso_output(ifp, m, sa, rt);
+       } else
+               error = ip_if_output(ifp, m, sa, rt);
+       goto done;
+
+fragment:
        /*
         * We can't use HW checksumming if we're about to fragment the packet.
         *
@@ -789,9 +790,7 @@
                } else {
                        KASSERT((m->m_pkthdr.csum_flags &
                            (M_CSUM_UDPv4 | M_CSUM_TCPv4)) == 0);
-                       error = ip_if_output(ifp, m,
-                           (m->m_flags & M_MCAST) ?
-                           sintocsa(rdst) : sintocsa(dst), rt);
+                       error = ip_if_output(ifp, m, sa, rt);
                }
        }
        if (error == 0) {