iptunnel: share common code when setting tunnel mode

Signed-off-by: Phil Sutter <phil@nwl.cc>

diff --git a/ip/iptunnel.c b/ip/iptunnel.c
index e323c1f7264f645a222723d4ceb52670e773a053..92edb34b11cbbbb0f46aa8d2157569e0058fda6a 100644 (file)
--- a/ip/iptunnel.c
+++ b/ip/iptunnel.c
@@ -47,6 +47,15 @@ static void usage(void)
        exit(-1);
 }
 
+static void set_tunnel_proto(struct ip_tunnel_parm *p, int proto)
+{
+       if (p->iph.protocol && p->iph.protocol != proto) {
+               fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
+               exit(-1);
+       }
+       p->iph.protocol = proto;
+}
+
 static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
 {
        int count = 0;
@@ -68,38 +77,18 @@ static int parse_args(int argc, char **argv, int cmd, struct ip_tunnel_parm *p)
                        NEXT_ARG();
                        if (strcmp(*argv, "ipip") == 0 ||
                            strcmp(*argv, "ip/ip") == 0) {
-                               if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
-                                       fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
-                                       exit(-1);
-                               }
-                               p->iph.protocol = IPPROTO_IPIP;
+                               set_tunnel_proto(p, IPPROTO_IPIP);
                        } else if (strcmp(*argv, "gre") == 0 ||
                                   strcmp(*argv, "gre/ip") == 0) {
-                               if (p->iph.protocol && p->iph.protocol != IPPROTO_GRE) {
-                                       fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
-                                       exit(-1);
-                               }
-                               p->iph.protocol = IPPROTO_GRE;
+                               set_tunnel_proto(p, IPPROTO_GRE);
                        } else if (strcmp(*argv, "sit") == 0 ||
                                   strcmp(*argv, "ipv6/ip") == 0) {
-                               if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
-                                       fprintf(stderr,"You managed to ask for more than one tunnel mode.\n");
-                                       exit(-1);
-                               }
-                               p->iph.protocol = IPPROTO_IPV6;
+                               set_tunnel_proto(p, IPPROTO_IPV6);
                        } else if (strcmp(*argv, "isatap") == 0) {
-                               if (p->iph.protocol && p->iph.protocol != IPPROTO_IPV6) {
-                                       fprintf(stderr, "You managed to ask for more than one tunnel mode.\n");
-                                       exit(-1);
-                               }
-                               p->iph.protocol = IPPROTO_IPV6;
+                               set_tunnel_proto(p, IPPROTO_IPV6);
                                isatap++;
                        } else if (strcmp(*argv, "vti") == 0) {
-                               if (p->iph.protocol && p->iph.protocol != IPPROTO_IPIP) {
-                                       fprintf(stderr, "You managed to ask for more than one tunnel mode.\n");
-                                       exit(-1);
-                               }
-                               p->iph.protocol = IPPROTO_IPIP;
+                               set_tunnel_proto(p, IPPROTO_IPIP);
                                p->i_flags |= VTI_ISVTI;
                        } else {
                                fprintf(stderr,"Unknown tunnel mode \"%s\"\n", *argv);