libbb: add a function to make a copy of a region of memory

Introduce a library routine to package the idiom:

    p = xmalloc(b, n);
    memcpy(p, b, n);

and use it where possible.  The example in traceroute used xzalloc
but it didn't need to.

function                                             old     new   delta
xmemdup                                                -      32     +32
last_main                                            834     826      -8
make_device                                         2321    2311     -10
common_traceroute_main                              3698    3685     -13
readtoken1                                          3182    3168     -14
procps_scan                                         1222    1206     -16
forkchild                                            655     638     -17
------------------------------------------------------------------------------
(add/remove: 1/0 grow/shrink: 0/6 up/down: 32/-78)            Total: -46 bytes

Signed-off-by: Ron Yorston <rmy@frippery.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 1 insertions, 10 deletions

diff --git a/networking/traceroute.c b/networking/traceroute.c
index 97a7a19e0..12ba614e8 100644
--- a/networking/traceroute.c
+++ b/networking/traceroute.c
@@ -387,15 +387,6 @@ struct globals {
 #define outudp  ((struct udphdr *)(outip + 1))
 
 
-/* libbb candidate? tftp uses this idiom too */
-static len_and_sockaddr* dup_sockaddr(const len_and_sockaddr *lsa)
-{
-        len_and_sockaddr *new_lsa = xzalloc(LSA_LEN_SIZE + lsa->len);
-        memcpy(new_lsa, lsa, LSA_LEN_SIZE + lsa->len);
-        return new_lsa;
-}
-
-
 static int
 wait_for_reply(len_and_sockaddr *from_lsa, struct sockaddr *to, unsigned *timestamp_us, int *left_ms)
 {
@@ -1074,7 +1065,7 @@ common_traceroute_main(int op, char **argv)
                 printf(" from %s", source);
         printf(", %d hops max, %d byte packets\n", max_ttl, packlen);
 
-        from_lsa = dup_sockaddr(dest_lsa);
+        from_lsa = xmemdup(dest_lsa, LSA_LEN_SIZE + dest_lsa->len);
         lastaddr = xzalloc(dest_lsa->len);
         to = xzalloc(dest_lsa->len);
         seq = 0;