traceroute: even with -v, don't show other ping processes reply's

function                                             old     new   delta
traceroute_init                                     1135    1151     +16
common_ping_main                                    1919    1935     +16
common_traceroute_main                              1715    1668     -47
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 32/-47)            Total: -15 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

2 files changed, 21 insertions, 2 deletions

diff --git a/networking/ping.c b/networking/ping.c
index 5f7e5b9b5..318d561bb 100644
--- a/networking/ping.c
+++ b/networking/ping.c
@@ -332,6 +332,11 @@ static int common_ping_main(sa_family_t af, char **argv)
 
         create_icmp_socket(lsa);
         G.myid = (uint16_t) getpid();
+        /* we can use native-endian ident, but other Unix ping/traceroute
+         * utils use *big-endian pid*, and e.g. traceroute on our machine may be
+         * *not* from busybox, idents may collide. Follow the convention:
+         */
+        G.myid = htons(G.myid);
 #if ENABLE_PING6
         if (lsa->u.sa.sa_family == AF_INET6)
                 ping6(lsa);
@@ -927,6 +932,11 @@ static int common_ping_main(int opt, char **argv)
         G.interval_us = interval * 1000000;
 
         myid = (uint16_t) getpid();
+        /* we can use native-endian ident, but other Unix ping/traceroute
+         * utils use *big-endian pid*, and e.g. traceroute on our machine may be
+         * *not* from busybox, idents may collide. Follow the convention:
+         */
+        myid = htons(myid);
         hostname = argv[optind];
 #if ENABLE_PING6
         {
diff --git a/networking/traceroute.c b/networking/traceroute.c
index 8ab4caefe..c1eb2d92e 100644
--- a/networking/traceroute.c
+++ b/networking/traceroute.c
@@ -659,9 +659,11 @@ packet4_ok(int read_len, int seq)
 
         if ((option_mask32 & OPT_USE_ICMP)
          && type == ICMP_ECHOREPLY
-         && icp->icmp_id == ident
          && icp->icmp_seq == htons(seq)
         ) {
+                if (icp->icmp_id != ident)
+                        /* reply to another ping/traceroute from this box? */
+                        return 0; /* ignore, silently */
                 /* In UDP mode, when we reach the machine, we (usually)
                  * would get "port unreachable" - in ICMP we got "echo reply".
                  * Simulate "port unreachable" for caller:
@@ -726,9 +728,11 @@ packet6_ok(int read_len, int seq)
 
         if ((option_mask32 & OPT_USE_ICMP)
          && type == ICMP6_ECHO_REPLY
-         && icp->icmp6_id == ident
          && icp->icmp6_seq == htons(seq)
         ) {
+                if (icp->icmp6_id != ident)
+                        /* reply to another ping/traceroute from this box? */
+                        return 0; /* ignore, silently */
                 /* In UDP mode, when we reach the machine, we (usually)
                  * would get "port unreachable" - in ICMP we got "echo reply".
                  * Simulate "port unreachable" for caller:
@@ -988,6 +992,11 @@ traceroute_init(int op, char **argv)
         outip = xzalloc(packlen);
 
         ident = getpid();
+        /* we can use native-endian ident, but other Unix ping/traceroute
+         * utils use *big-endian pid*, and e.g. ping on our machine may be
+         * *not* from busybox, idents may collide. Follow the convention:
+         */
+        ident = htons(ident);
 
         outdata = (void*)(outudp + 1);
         if (af == AF_INET) {