User-defined TTL for external IP header.

diff --git a/sys/netinet/ip_ip4.c b/sys/netinet/ip_ip4.c
index b16b078..206af88 100644 (file)
--- a/sys/netinet/ip_ip4.c
+++ b/sys/netinet/ip_ip4.c
@@ -151,6 +151,7 @@ int
 ipe4_output(struct mbuf *m, struct sockaddr_encap *gw, struct tdb *tdb, struct mbuf **mp)
 {
        struct ip *ipo, *ipi;
+       struct ip4_xdata *xd;
        ushort ilen;
 
        ipi = mtod(m, struct ip *);
@@ -169,7 +170,19 @@ ipe4_output(struct mbuf *m, struct sockaddr_encap *gw, struct tdb *tdb, struct m
        /* ipo->ip_id = htons(ip_id++); */
        get_random_bytes((void *)&(ipo->ip_id), sizeof(ipo->ip_id));
        ipo->ip_off = ipi->ip_off & ~(IP_MF | IP_OFFMASK); /* keep C and DF */
-       ipo->ip_ttl = ipi->ip_ttl;      /* already decremented if fwding */
+       xd = (struct ip4_xdata *)tdb->tdb_xdata;
+       switch (xd->ip4_ttl)
+       {
+           case IP4_SAME_TTL:
+               ipo->ip_ttl = ipi->ip_ttl;
+               break;
+           case IP4_DEFAULT_TTL:
+               ipo->ip_ttl = ip_defttl;
+               break;
+           default:
+               ipo->ip_ttl = xd->ip4_ttl;
+       }
+       
        ipo->ip_p = IPPROTO_IPIP;
        ipo->ip_sum = 0;
        ipo->ip_src = gw->sen_ipsp_src;
@@ -197,17 +210,39 @@ ipe4_attach()
 int
 ipe4_init(struct tdb *tdbp, struct xformsw *xsp, struct mbuf *m)
 {
-       printf("ipe4_init: setting up\n");
+        struct ip4_xdata *xd;
+       struct ip4_xencap txd;
+       struct encap_msghdr *em;
+       
+#ifdef ENCDEBUG
+        if (encdebug)
+         printf("ipe4_init: setting up\n");
+#endif
        tdbp->tdb_xform = xsp;
-       if (m)
-         m_freem(m);
+       MALLOC(tdbp->tdb_xdata, caddr_t, sizeof (struct ip4_xdata), M_XDATA,
+              M_WAITOK);
+       if (tdbp->tdb_xdata == NULL)
+         return ENOBUFS;
+       bzero(tdbp->tdb_xdata, sizeof (struct ip4_xdata));
+       xd = (struct ip4_xdata *)tdbp->tdb_xdata;
+       
+       em = mtod(m, struct encap_msghdr *);
+       if (em->em_msglen - EMT_SETSPI_FLEN > sizeof (struct ip4_xencap))
+       {
+           free((caddr_t)tdbp->tdb_xdata, M_XDATA);
+           tdbp->tdb_xdata = NULL;
+           return EINVAL;
+       }
+       m_copydata(m, EMT_SETSPI_FLEN, em->em_msglen - EMT_SETSPI_FLEN,
+                  (caddr_t)&txd);
+       xd->ip4_ttl = txd.ip4_ttl;
        return 0;
 }
 
 int
 ipe4_zeroize(struct tdb *tdbp)
 {
-       /* Nothing much really - we don't need any state */
+        FREE(tdbp->tdb_xdata, M_XDATA);
        return 0;
 }
 

diff --git a/sys/netinet/ip_ip4.h b/sys/netinet/ip_ip4.h
index 4e580fe..ec6b214 100644 (file)
--- a/sys/netinet/ip_ip4.h
+++ b/sys/netinet/ip_ip4.h
@@ -26,6 +26,16 @@
  * Not quite all the functionality of RFC-1853, but the main idea is there.
  */
 
+struct ip4_xdata
+{
+    int32_t ip4_ttl;
+};
+
+struct ip4_xencap
+{
+    int32_t ip4_ttl;
+};
+
 struct ip4stat
 {
        u_long  ip4s_ipackets;          /* total input packets */
@@ -35,6 +45,9 @@ struct ip4stat
        u_long  ip4s_qfull;
 };
 
+#define IP4_SAME_TTL 0
+#define IP4_DEFAULT_TTL -1
+
 #ifdef _KERNEL
 struct ip4stat ip4stat;
 #endif