diff options
| -rw-r--r-- | libc/inet/if_nametoindex.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/libc/inet/if_nametoindex.c b/libc/inet/if_nametoindex.c index a697419b6..45b319f97 100644 --- a/libc/inet/if_nametoindex.c +++ b/libc/inet/if_nametoindex.c @@ -148,6 +148,27 @@ struct if_nameindex * if_nameindex (void) char * if_indextoname (unsigned int ifindex, char *ifname) { +#ifdef SIOCGIFNAME + /* Use ioctl to avoid searching the list. */ + struct ifreq ifr; + int fd, saved_errno; + + fd = __opensock (); + + if (fd < 0) + return NULL; + + ifr.ifr_ifindex = ifindex; + if (ioctl (fd, SIOCGIFNAME, &ifr) < 0) { + saved_errno = errno; + close (fd); + __set_errno (saved_errno); + return NULL; + } + close (fd); + + return strncpy (ifname, ifr.ifr_name, IFNAMSIZ); +#else struct if_nameindex *idx; struct if_nameindex *p; char *result = NULL; @@ -163,5 +184,6 @@ char * if_indextoname (unsigned int ifindex, char *ifname) if_freenameindex (idx); } return result; +#endif } |