factor our ether_addheader for readability; there's more to come there

ok claudio reyk

diff --git a/sys/net/if_ethersubr.c b/sys/net/if_ethersubr.c
index cf0de75..6184dde 100644 (file)
--- a/sys/net/if_ethersubr.c
+++ b/sys/net/if_ethersubr.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_ethersubr.c,v 1.167 2014/04/20 14:54:39 henning Exp $      */
+/*     $OpenBSD: if_ethersubr.c,v 1.168 2014/04/20 15:29:52 henning Exp $      */
 /*     $NetBSD: if_ethersubr.c,v 1.19 1996/05/07 02:40:30 thorpej Exp $        */
 
 /*
@@ -155,6 +155,9 @@ u_char etherbroadcastaddr[ETHER_ADDR_LEN] =
     { 0xff, 0xff, 0xff, 0xff, 0xff, 0xff };
 #define senderr(e) { error = (e); goto bad;}
 
+static __inline int    ether_addheader(struct mbuf **, u_int16_t, u_char *,
+                          u_char *);
+
 int
 ether_ioctl(struct ifnet *ifp, struct arpcom *arp, u_long cmd, caddr_t data)
 {
@@ -189,6 +192,21 @@ ether_ioctl(struct ifnet *ifp, struct arpcom *arp, u_long cmd, caddr_t data)
        return (error);
 }
 
+static __inline int
+ether_addheader(struct mbuf **m, u_int16_t etype, u_char *esrc, u_char *edst)
+{
+       struct ether_header *eh;
+
+       M_PREPEND(*m, ETHER_HDR_LEN, M_DONTWAIT);
+       if (*m == 0)
+               return (-1);
+       eh = mtod(*m, struct ether_header *);
+       eh->ether_type = etype;
+       memcpy(eh->ether_dhost, edst, sizeof(eh->ether_dhost));
+       memcpy(eh->ether_shost, esrc, sizeof(eh->ether_shost));
+       return (0);
+}
+
 /*
  * Ethernet output routine.
  * Encapsulate a packet of type family for the local net.
@@ -348,17 +366,8 @@ ether_output(struct ifnet *ifp0, struct mbuf *m0, struct sockaddr *dst,
                esrc = carp_get_srclladdr(ifp0, esrc);
 #endif
 
-       /*
-        * Add local net header.  If no space in first mbuf,
-        * allocate another.
-        */
-       M_PREPEND(m, ETHER_HDR_LEN, M_DONTWAIT);
-       if (m == 0)
+       if (ether_addheader(&m, etype, esrc, edst) == -1)
                senderr(ENOBUFS);
-       eh = mtod(m, struct ether_header *);
-       eh->ether_type = etype;
-       memcpy(eh->ether_dhost, edst, sizeof(eh->ether_dhost));
-       memcpy(eh->ether_shost, esrc, sizeof(eh->ether_shost));
 
 #if NBRIDGE > 0
        /*