ospf6d: Fix LSA formatting inconsistent retvals

Make return values for lh_get_prefix_str LSA handlers consistent, i.e.
return NULL in case of error without having written to the passed buffer
and non-NULL (address of buffer) if a string was written to the buffer.

Previously, it was possible in certain cases (bogus LSAs) to not initialize
(and 0-terminate) the buffer but still return non-NULL, causing the caller
to print random junk.

Signed-off-by: Martin Buck <mb-tmp-tvguho.pbz@gromit.dyndns.org>

diff --git a/ospf6d/ospf6_intra.c b/ospf6d/ospf6_intra.c
index 01e4b31c4ef4b44c9048a7a433e9f2c98d638156..fd154e7ee53e49b5af0c74d9f0bbf70788c9e826 100644 (file)
--- a/ospf6d/ospf6_intra.c
+++ b/ospf6d/ospf6_intra.c
@@ -84,12 +84,13 @@ static char *ospf6_router_lsa_get_nbr_id(struct ospf6_lsa *lsa, char *buf,
                                inet_ntop(AF_INET, &lsdesc->neighbor_router_id,
                                          buf2, sizeof(buf2));
                                sprintf(buf, "%s/%s", buf2, buf1);
+
+                               return buf;
                        }
-               } else
-                       return NULL;
+               }
        }
 
-       return buf;
+       return NULL;
 }
 
 static int ospf6_router_lsa_show(struct vty *vty, struct ospf6_lsa *lsa,
@@ -444,14 +445,15 @@ static char *ospf6_network_lsa_get_ar_id(struct ospf6_lsa *lsa, char *buf,
 
                if ((current + sizeof(struct ospf6_network_lsdesc)) <= end) {
                        lsdesc = (struct ospf6_network_lsdesc *)current;
-                       if (buf)
+                       if (buf) {
                                inet_ntop(AF_INET, &lsdesc->router_id, buf,
                                          buflen);
-               } else
-                       return NULL;
+                               return buf;
+                       }
+               }
        }
 
-       return (buf);
+       return NULL;
 }
 
 static int ospf6_network_lsa_show(struct vty *vty, struct ospf6_lsa *lsa,
@@ -901,7 +903,7 @@ static char *ospf6_intra_prefix_lsa_get_prefix_str(struct ospf6_lsa *lsa,
                        }
                } while (current <= end);
        }
-       return (buf);
+       return NULL;
 }
 
 static int ospf6_intra_prefix_lsa_show(struct vty *vty, struct ospf6_lsa *lsa,