dhcpd: write lease file on exit

[oweals/busybox.git] / networking / ipcalc.c

diff --git a/networking/ipcalc.c b/networking/ipcalc.c
index 78558495ece4d48f85ecf7544504be7e39475578..3c8b8bfc910026c270161fd829178d61f7c623f6 100644 (file)
--- a/networking/ipcalc.c
+++ b/networking/ipcalc.c
@@ -9,17 +9,41 @@
  * from Red Hat.  I didn't look at their source code, but there
  * is no denying that this is a loving reimplementation
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#include <sys/socket.h>
-#include <arpa/inet.h>
+//usage:#define ipcalc_trivial_usage
+//usage:       "[OPTIONS] ADDRESS[[/]NETMASK] [NETMASK]"
+//usage:#define ipcalc_full_usage "\n\n"
+//usage:       "Calculate IP network settings from a IP address\n"
+//usage:       IF_FEATURE_IPCALC_LONG_OPTIONS(
+//usage:     "\n       -b,--broadcast  Display calculated broadcast address"
+//usage:     "\n       -n,--network    Display calculated network address"
+//usage:     "\n       -m,--netmask    Display default netmask for IP"
+//usage:       IF_FEATURE_IPCALC_FANCY(
+//usage:     "\n       -p,--prefix     Display the prefix for IP/NETMASK"
+//usage:     "\n       -h,--hostname   Display first resolved host name"
+//usage:     "\n       -s,--silent     Don't ever display error messages"
+//usage:       )
+//usage:       )
+//usage:       IF_NOT_FEATURE_IPCALC_LONG_OPTIONS(
+//usage:     "\n       -b      Display calculated broadcast address"
+//usage:     "\n       -n      Display calculated network address"
+//usage:     "\n       -m      Display default netmask for IP"
+//usage:       IF_FEATURE_IPCALC_FANCY(
+//usage:     "\n       -p      Display the prefix for IP/NETMASK"
+//usage:     "\n       -h      Display first resolved host name"
+//usage:     "\n       -s      Don't ever display error messages"
+//usage:       )
+//usage:       )
 
 #include "libbb.h"
+/* After libbb.h, because on some systems it needs other includes */
+#include <arpa/inet.h>
 
-#define CLASS_A_NETMASK        ntohl(0xFF000000)
-#define CLASS_B_NETMASK        ntohl(0xFFFF0000)
-#define CLASS_C_NETMASK        ntohl(0xFFFFFF00)
+#define CLASS_A_NETMASK ntohl(0xFF000000)
+#define CLASS_B_NETMASK ntohl(0xFFFF0000)
+#define CLASS_C_NETMASK ntohl(0xFFFFFF00)
 
 static unsigned long get_netmask(unsigned long ipaddr)
 {
@@ -63,13 +87,13 @@ int get_prefix(unsigned long netmask);
 
 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
        static const char ipcalc_longopts[] ALIGN1 =
-               "netmask\0"   No_argument "m"
-               "broadcast\0" No_argument "b"
-               "network\0"   No_argument "n"
+               "netmask\0"   No_argument "m" // netmask from IP (assuming complete class A, B, or C network)
+               "broadcast\0" No_argument "b" // broadcast from IP [netmask]
+               "network\0"   No_argument "n" // network from IP [netmask]
 # if ENABLE_FEATURE_IPCALC_FANCY
-               "prefix\0"    No_argument "p"
-               "hostname\0"  No_argument "h"
-               "silent\0"    No_argument "s"
+               "prefix\0"    No_argument "p" // prefix from IP[/prefix] [netmask]
+               "hostname\0"  No_argument "h" // hostname from IP
+               "silent\0"    No_argument "s" // don’t ever display error messages
 # endif
                ;
 #endif
@@ -92,15 +116,16 @@ int ipcalc_main(int argc UNUSED_PARAM, char **argv)
 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
        applet_long_options = ipcalc_longopts;
 #endif
+       opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
        opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
        argv += optind;
        if (opt & SILENT)
                logmode = LOGMODE_NONE; /* suppress error_msg() output */
-       if (opt & (BROADCAST | NETWORK | NETPREFIX)) {
-               if (!argv[0] || !argv[1] || argv[2])
-                       bb_show_usage();
-       } else {
-               if (!argv[0] || argv[1])
+       opt &= ~SILENT;
+       if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
+               /* if no options at all or
+                * (no broadcast,network,prefix) and (two args)... */
+               if (!opt || argv[1])
                        bb_show_usage();
        }