[src/trunk]: src/sys/netinet Separate IP address matching functions

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

details:   https://anonhg.NetBSD.org/src/rev/bc88512eb166
branches:  trunk
changeset: 346273:bc88512eb166
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Mon Jul 04 08:10:50 2016 +0000

description:
Separate IP address matching functions

No functional change intended.

diffstat:

 sys/netinet/ip_input.c |  145 +++++++++++++++++++++++++++++-------------------
 1 files changed, 88 insertions(+), 57 deletions(-)

diffs (200 lines):

diff -r 50812f527248 -r bc88512eb166 sys/netinet/ip_input.c
--- a/sys/netinet/ip_input.c    Mon Jul 04 07:56:07 2016 +0000
+++ b/sys/netinet/ip_input.c    Mon Jul 04 08:10:50 2016 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ip_input.c,v 1.332 2016/06/30 06:56:27 ozaki-r Exp $   */
+/*     $NetBSD: ip_input.c,v 1.333 2016/07/04 08:10:50 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_input.c,v 1.332 2016/06/30 06:56:27 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ip_input.c,v 1.333 2016/07/04 08:10:50 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_inet.h"
@@ -289,6 +289,11 @@
 static struct in_ifaddr *ip_rtaddr(struct in_addr);
 static void            sysctl_net_inet_ip_setup(struct sysctllog **);
 
+static struct in_ifaddr        *ip_match_our_address(struct ifnet *, struct ip *,
+                           int *);
+static struct in_ifaddr        *ip_match_our_address_broadcast(struct ifnet *,
+                           struct ip *);
+
 /* XXX: Not yet enabled. */
 #define        SOFTNET_LOCK()          KASSERT(mutex_owned(softnet_lock))
 #define        SOFTNET_UNLOCK()        KASSERT(mutex_owned(softnet_lock))
@@ -342,6 +347,81 @@
        ipstat_percpu = percpu_alloc(sizeof(uint64_t) * IP_NSTATS);
 }
 
+static struct in_ifaddr *
+ip_match_our_address(struct ifnet *ifp, struct ip *ip, int *downmatch)
+{
+       struct in_ifaddr *ia = NULL;
+       int checkif;
+
+       /*
+        * Enable a consistency check between the destination address
+        * and the arrival interface for a unicast packet (the RFC 1122
+        * strong ES model) if IP forwarding is disabled and the packet
+        * is not locally generated.
+        *
+        * XXX - Checking also should be disabled if the destination
+        * address is ipnat'ed to a different interface.
+        *
+        * XXX - Checking is incompatible with IP aliases added
+        * to the loopback interface instead of the interface where
+        * the packets are received.
+        *
+        * XXX - We need to add a per ifaddr flag for this so that
+        * we get finer grain control.
+        */
+       checkif = ip_checkinterface && (ipforwarding == 0) &&
+           (ifp->if_flags & IFF_LOOPBACK) == 0;
+
+       LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
+               if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
+                       if (ia->ia4_flags & IN_IFF_NOTREADY)
+                               continue;
+                       if (checkif && ia->ia_ifp != ifp)
+                               continue;
+                       if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
+                               break;
+                       else
+                               downmatch++;
+               }
+       }
+
+       return ia;
+}
+
+static struct in_ifaddr *
+ip_match_our_address_broadcast(struct ifnet *ifp, struct ip *ip)
+{
+       struct in_ifaddr *ia = NULL;
+       struct ifaddr *ifa;
+
+       IFADDR_FOREACH(ifa, ifp) {
+               if (ifa->ifa_addr->sa_family != AF_INET)
+                       continue;
+               ia = ifatoia(ifa);
+               if (ia->ia4_flags & IN_IFF_NOTREADY)
+                       continue;
+               if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
+                   in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
+                   /*
+                    * Look for all-0's host part (old broadcast addr),
+                    * either for subnet or net.
+                    */
+                   ip->ip_dst.s_addr == ia->ia_subnet ||
+                   ip->ip_dst.s_addr == ia->ia_net)
+                       goto matched;
+               /*
+                * An interface with IP address zero accepts
+                * all packets that arrive on that interface.
+                */
+               if (in_nullhost(ia->ia_addr.sin_addr))
+                       goto matched;
+       }
+       ia = NULL;
+
+matched:
+       return ia;
+}
+
 /*
  * IP software interrupt routine.
  */
@@ -368,10 +448,8 @@
 {
        struct ip *ip = NULL;
        struct in_ifaddr *ia;
-       struct ifaddr *ifa;
        int hlen = 0, len;
        int downmatch;
-       int checkif;
        int srcrt = 0;
        ifnet_t *ifp;
        struct psref psref;
@@ -581,25 +659,6 @@
                goto out;
 
        /*
-        * Enable a consistency check between the destination address
-        * and the arrival interface for a unicast packet (the RFC 1122
-        * strong ES model) if IP forwarding is disabled and the packet
-        * is not locally generated.
-        *
-        * XXX - Checking also should be disabled if the destination
-        * address is ipnat'ed to a different interface.
-        *
-        * XXX - Checking is incompatible with IP aliases added
-        * to the loopback interface instead of the interface where
-        * the packets are received.
-        *
-        * XXX - We need to add a per ifaddr flag for this so that
-        * we get finer grain control.
-        */
-       checkif = ip_checkinterface && (ipforwarding == 0) &&
-           (ifp->if_flags & IFF_LOOPBACK) == 0;
-
-       /*
         * Check our list of addresses, to see if the packet is for us.
         *
         * Traditional 4.4BSD did not consult IFF_UP at all.
@@ -607,44 +666,16 @@
         * or IN_IFF_NOTREADY addresses as not mine.
         */
        downmatch = 0;
-       LIST_FOREACH(ia, &IN_IFADDR_HASH(ip->ip_dst.s_addr), ia_hash) {
-               if (in_hosteq(ia->ia_addr.sin_addr, ip->ip_dst)) {
-                       if (ia->ia4_flags & IN_IFF_NOTREADY)
-                               continue;
-                       if (checkif && ia->ia_ifp != ifp)
-                               continue;
-                       if ((ia->ia_ifp->if_flags & IFF_UP) != 0)
-                               break;
-                       else
-                               downmatch++;
-               }
-       }
+       ia = ip_match_our_address(ifp, ip, &downmatch);
        if (ia != NULL)
                goto ours;
+
        if (ifp->if_flags & IFF_BROADCAST) {
-               IFADDR_FOREACH(ifa, ifp) {
-                       if (ifa->ifa_addr->sa_family != AF_INET)
-                               continue;
-                       ia = ifatoia(ifa);
-                       if (ia->ia4_flags & IN_IFF_NOTREADY)
-                               continue;
-                       if (in_hosteq(ip->ip_dst, ia->ia_broadaddr.sin_addr) ||
-                           in_hosteq(ip->ip_dst, ia->ia_netbroadcast) ||
-                           /*
-                            * Look for all-0's host part (old broadcast addr),
-                            * either for subnet or net.
-                            */
-                           ip->ip_dst.s_addr == ia->ia_subnet ||
-                           ip->ip_dst.s_addr == ia->ia_net)
-                               goto ours;
-                       /*
-                        * An interface with IP address zero accepts
-                        * all packets that arrive on that interface.
-                        */
-                       if (in_nullhost(ia->ia_addr.sin_addr))
-                               goto ours;
-               }
+               ia = ip_match_our_address_broadcast(ifp, ip);
+               if (ia != NULL)
+                       goto ours;
        }
+
        if (IN_MULTICAST(ip->ip_dst.s_addr)) {
 #ifdef MROUTING
                extern struct socket *ip_mrouter;