new option --rdns

ChangeLog

@@ -15,9 +15,14 @@ Unreleased
 
   * Version 4.0
   * (feature) Unified 'fping' and 'fping6' into one binary (#80)
+  * (feature) Long option names for all options
   * (feature) --enable-ipv6 is now default
-  * (feature) New option '-4' to force IPv4
+  * (feature) New option -4 to force IPv4
-  * (feature) New option '-6' to force IPv6
+  * (feature) New option -6 to force IPv6
+  * (feature) Keep original name if a hostname is given with -n/--name
+  * (feature) New option -X/--rdns, similar to -n/--name, but which always
+              does a rdns-lookup, even for names (name->IP->name), as '-n'
+	      was doing until now
   * (bugfix)  Fix compatibility issue with GNU Hurd
   * (other)   A C99 compiler is now required
   * (other)   Option parsing with optparse (https://github.com/skeeto/optparse)

ci/test-14-ping-internet-hosts.pl

@@ -9,7 +9,7 @@ if(!gethostbyname("www.google.com")) {
     exit 0;
 }
 
-plan tests => 21;
+plan tests => 27;
 
 my $re_num = qr{\d+(?:\.\d+)?};
 
@@ -41,6 +41,22 @@ $cmd->stdout_is_eq("google-public-dns-a.google.com (8.8.8.8) is alive\n");
 $cmd->stderr_is_eq("");
 }
 
+# fping -4 --addr --rdns
+{
+my $cmd = Test::Command->new(cmd => "fping -4 --addr --rdns www.google.com");
+$cmd->exit_is_num(0);
+$cmd->stdout_like(qr{^\S+\.1e100\.net \(\d+\.\d+\.\d+\.\d+\) is alive\n$});
+$cmd->stderr_is_eq("");
+}
+
+# fping -4 --addr --name
+{
+my $cmd = Test::Command->new(cmd => "fping -4 --addr --name www.google.com");
+$cmd->exit_is_num(0);
+$cmd->stdout_like(qr{^www\.google\.com \(\d+\.\d+\.\d+\.\d+\) is alive\n$});
+$cmd->stderr_is_eq("");
+}
+
 # fping -A -n (IPv6)
 SKIP: {
     if(system("/sbin/ifconfig | grep inet6.*Scope:Global") != 0) {

src/fping.c

@@ -281,7 +281,7 @@ struct timezone tz;
 int generate_flag = 0; /* flag for IP list generation */
 int verbose_flag, quiet_flag, stats_flag, unreachable_flag, alive_flag;
 int elapsed_flag, version_flag, count_flag, loop_flag, netdata_flag;
-int per_recv_flag, report_all_rtts_flag, name_flag, addr_flag, backoff_flag;
+int per_recv_flag, report_all_rtts_flag, name_flag, addr_flag, backoff_flag, rdns_flag;
 int multif_flag;
 int outage_flag = 0;
 int timestamp_flag = 0;
@@ -376,7 +376,7 @@ int main(int argc, char** argv)
         { "backoff", 'B', OPTPARSE_REQUIRED },
         { "count", 'c', OPTPARSE_REQUIRED },
         { "vcount", 'C', OPTPARSE_REQUIRED },
-        { NULL,        'd', OPTPARSE_NONE }, // same as '--names'
+        { NULL, 'd', OPTPARSE_NONE }, // same as '--name'
         { "timestamp", 'D', OPTPARSE_NONE },
         { "elapsed", 'e', OPTPARSE_NONE },
         { "file", 'f', OPTPARSE_REQUIRED },
@@ -388,7 +388,7 @@ int main(int argc, char** argv)
         { "loop", 'l', OPTPARSE_NONE },
         { "all", 'm', OPTPARSE_NONE },
         { "dontfrag", 'M', OPTPARSE_NONE },
-        { "names",     'n', OPTPARSE_NONE },
+        { "name", 'n', OPTPARSE_NONE },
         { "netdata", 'N', OPTPARSE_NONE },
         { "outage", 'o', OPTPARSE_NONE },
         { "tos", 'O', OPTPARSE_REQUIRED },
@@ -403,7 +403,7 @@ int main(int argc, char** argv)
         { NULL, 'T', OPTPARSE_REQUIRED },
         { "unreach", 'u', OPTPARSE_NONE },
         { "version", 'v', OPTPARSE_NONE },
-        { "rdns",      'X', OPTPARSE_NONE }, // FIXME: similar to --names, but do name->IP->name if a name is provided
+        { "rdns", 'X', OPTPARSE_NONE }, // FIXME: similar to --name, but do name->IP->name if a name is provided
         { 0, 0, 0 }
     };
 
@@ -529,6 +529,10 @@ int main(int argc, char** argv)
             name_flag = 1;
             break;
 
+        case 'X':
+            rdns_flag = 1;
+            break;
+
         case 'A':
             addr_flag = 1;
             break;
@@ -2215,23 +2219,28 @@ void add_name(char* name)
      */
     for (res = res0; res; res = res->ai_next) {
         /* name_flag: addr -> name lookup requested) */
-        if (!name_flag) {
+        if (name_flag || rdns_flag) {
-            printname = name;
+            int do_rdns = rdns_flag ? 1 : 0;
+            if (name_flag) {
+                /* Was it a numerical address? Only then do a rdns-query */
+                struct addrinfo* nres;
+                hints.ai_flags = AI_NUMERICHOST;
+                if (getaddrinfo(name, NULL, &hints, &nres) == 0) {
+                    do_rdns = 1;
+                    freeaddrinfo(nres);
                 }
-        else {
-            int ret;
-            ret = getnameinfo(res->ai_addr, res->ai_addrlen, namebuf,
-                sizeof(namebuf) / sizeof(char), NULL, 0, 0);
-            if (ret) {
-                if (!quiet_flag) {
-                    print_warning("%s: can't reverse-lookup (%s)\n", name, gai_strerror(ret));
             }
-                printname = name;
+
+            if (do_rdns && getnameinfo(res->ai_addr, res->ai_addrlen, namebuf, sizeof(namebuf) / sizeof(char), NULL, 0, 0) == 0) {
+                printname = namebuf;
             }
             else {
-                printname = namebuf;
+                printname = name;
             }
         }
+        else {
+            printname = name;
+        }
 
         /* addr_flag: name -> addr lookup requested */
         if (addr_flag) {
@@ -2245,7 +2254,7 @@ void add_name(char* name)
                 continue;
             }
 
-            if (name_flag) {
+            if (name_flag || rdns_flag) {
                 char nameaddrbuf[512];
                 snprintf(nameaddrbuf, sizeof(nameaddrbuf) / sizeof(char), "%s (%s)", printname, addrbuf);
                 add_addr(name, nameaddrbuf, res->ai_addr, res->ai_addrlen);