xnu-3248.40.184.tar.gz

[apple/xnu.git] / bsd / netinet / in_gif.c

diff --git a/bsd/netinet/in_gif.c b/bsd/netinet/in_gif.c
index 66bf01c30ee5c32fd0ff4cc412fba6a6b100f6c7..0cd7a22874af3474c83ffa75c1c2c14518c92e5b 100644 (file)
--- a/bsd/netinet/in_gif.c
+++ b/bsd/netinet/in_gif.c
@@ -177,12 +177,12 @@ in_gif_output(
        iphdr.ip_ttl = ip_gif_ttl;
        iphdr.ip_len = m->m_pkthdr.len + sizeof (struct ip);
        if (ifp->if_flags & IFF_LINK1)
-               ip_ecn_ingress(ECN_ALLOWED, &iphdr.ip_tos, &tos);
+               ip_ecn_ingress(ECN_NORMAL, &iphdr.ip_tos, &tos);
        else
                ip_ecn_ingress(ECN_NOCARE, &iphdr.ip_tos, &tos);
 
        /* prepend new IP header */
-       M_PREPEND(m, sizeof (struct ip), M_DONTWAIT);
+       M_PREPEND(m, sizeof (struct ip), M_DONTWAIT, 0);
        if (m && mbuf_len(m) < sizeof (struct ip))
                m = m_pullup(m, sizeof (struct ip));
        if (m == NULL) {
@@ -239,7 +239,9 @@ in_gif_input(m, off)
        struct ifnet *gifp = NULL;
        struct ip *ip;
        int af, proto;
-       u_int8_t otos;
+       u_int8_t otos, old_tos;
+       int egress_success = 0;
+       int sum;
 
        ip = mtod(m, struct ip *);
        proto = ip->ip_p;
@@ -267,10 +269,18 @@ in_gif_input(m, off)
                                return;
                }
                ip = mtod(m, struct ip *);
-               if (gifp->if_flags & IFF_LINK1)
-                       ip_ecn_egress(ECN_ALLOWED, &otos, &ip->ip_tos);
-               else
-                       ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
+               if (gifp->if_flags & IFF_LINK1) {
+                       old_tos = ip->ip_tos;
+                       egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &ip->ip_tos);
+                       if (old_tos != ip->ip_tos) {
+                           sum = ~ntohs(ip->ip_sum) & 0xffff;
+                           sum += (~otos & 0xffff) + ip->ip_tos;
+                           sum = (sum >> 16) + (sum & 0xffff);
+                           sum += (sum >> 16);  /* add carry */
+                           ip->ip_sum = htons(~sum & 0xffff);
+                       }
+               } else
+                       egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &ip->ip_tos);
                break;
            }
 #endif
@@ -288,9 +298,9 @@ in_gif_input(m, off)
                ip6 = mtod(m, struct ip6_hdr *);
                itos = (ntohl(ip6->ip6_flow) >> 20) & 0xff;
                if (gifp->if_flags & IFF_LINK1)
-                       ip_ecn_egress(ECN_ALLOWED, &otos, &itos);
+                       egress_success = ip_ecn_egress(ECN_NORMAL, &otos, &itos);
                else
-                       ip_ecn_egress(ECN_NOCARE, &otos, &itos);
+                       egress_success = ip_ecn_egress(ECN_NOCARE, &otos, &itos);
                ip6->ip6_flow &= ~htonl(0xff << 20);
                ip6->ip6_flow |= htonl((u_int32_t)itos << 20);
                break;
@@ -301,6 +311,13 @@ in_gif_input(m, off)
                m_freem(m);
                return;
        }
+
+       if (egress_success == 0) {
+               OSAddAtomic(1, &ipstat.ips_nogif);
+               m_freem(m);
+               return;
+       }
+
 #ifdef __APPLE__
        /* Replace the rcvif by gifp for dlil to route it correctly */
        if (m->m_pkthdr.rcvif)