Big cleanup in config help and description
[oweals/busybox.git] / networking / ipcalc.c
index 8c61e3a71b43589cb76bdd1a3ee7a782681b80ce..9359f901611969e8978432e50a928fc5c7d5b83a 100644 (file)
@@ -1,4 +1,4 @@
-/* vi: set sw=4 ts=4 ai: */
+/* vi: set sw=4 ts=4: */
 /*
  * Mini ipcalc implementation for busybox
  *
@@ -9,20 +9,65 @@
  * 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 "busybox.h"
-#include <ctype.h>
-#include <getopt.h>
-#include <sys/socket.h>
+//config:config IPCALC
+//config:      bool "ipcalc"
+//config:      default y
+//config:      help
+//config:        ipcalc takes an IP address and netmask and calculates the
+//config:        resulting broadcast, network, and host range.
+//config:
+//config:config FEATURE_IPCALC_LONG_OPTIONS
+//config:      bool "Enable long options"
+//config:      default y
+//config:      depends on IPCALC && LONG_OPTS
+//config:
+//config:config FEATURE_IPCALC_FANCY
+//config:      bool "Fancy IPCALC, more options, adds 1 kbyte"
+//config:      default y
+//config:      depends on IPCALC
+//config:      help
+//config:        Adds the options hostname, prefix and silent to the output of
+//config:        "ipcalc".
+
+//applet:IF_IPCALC(APPLET(ipcalc, BB_DIR_BIN, BB_SUID_DROP))
+
+//kbuild:lib-$(CONFIG_IPCALC) += ipcalc.o
+
+//usage:#define ipcalc_trivial_usage
+//usage:       "[OPTIONS] ADDRESS"
+//usage:       IF_FEATURE_IPCALC_FANCY("[/PREFIX]") " [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 IPCALC_MSG(CMD,ALTCMD) if (mode & SILENT) {ALTCMD;} else {CMD;}
-
-#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)
 {
@@ -38,14 +83,14 @@ static unsigned long get_netmask(unsigned long ipaddr)
                return 0;
 }
 
-#ifdef CONFIG_FEATURE_IPCALC_FANCY
+#if ENABLE_FEATURE_IPCALC_FANCY
 static int get_prefix(unsigned long netmask)
 {
        unsigned long msk = 0x80000000;
        int ret = 0;
 
        netmask = htonl(netmask);
-       while(msk) {
+       while (msk) {
                if (netmask & msk)
                        ret++;
                msk >>= 1;
@@ -56,6 +101,7 @@ static int get_prefix(unsigned long netmask)
 int get_prefix(unsigned long netmask);
 #endif
 
+
 #define NETMASK   0x01
 #define BROADCAST 0x02
 #define NETWORK   0x04
@@ -64,43 +110,46 @@ int get_prefix(unsigned long netmask);
 #define SILENT    0x20
 
 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
-       static const struct option long_options[] = {
-               {"netmask",             no_argument, NULL, 'm'},
-               {"broadcast",   no_argument, NULL, 'b'},
-               {"network",             no_argument, NULL, 'n'},
-#ifdef CONFIG_FEATURE_IPCALC_FANCY
-               {"prefix",              no_argument, NULL, 'p'},
-               {"hostname",    no_argument, NULL, 'h'},
-               {"silent",              no_argument, NULL, 's'},
-#endif
-               {NULL, 0, NULL, 0}
-       };
-#else
-#define long_options 0
+       static const char ipcalc_longopts[] ALIGN1 =
+               "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" // 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
 
-
-
-int ipcalc_main(int argc, char **argv)
+int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int ipcalc_main(int argc UNUSED_PARAM, char **argv)
 {
-       unsigned long mode;
-       int have_netmask = 0;
-       in_addr_t netmask, broadcast, network, ipaddr;
-       struct in_addr a;
+       unsigned opt;
+       bool have_netmask = 0;
+       struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
+       /* struct in_addr { in_addr_t s_addr; }  and  in_addr_t
+        * (which in turn is just a typedef to uint32_t)
+        * are essentially the same type. A few macros for less verbosity: */
+#define netmask   (s_netmask.s_addr)
+#define broadcast (s_broadcast.s_addr)
+#define network   (s_network.s_addr)
+#define ipaddr    (s_ipaddr.s_addr)
        char *ipstr;
 
-       if (ENABLE_FEATURE_IPCALC_LONG_OPTIONS)
-               bb_applet_long_options = long_options;
-
-       mode = bb_getopt_ulflags(argc, argv, "mbn" USE_FEATURE_IPCALC_FANCY("phs"));
-
-       argc -= optind;
+#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 (mode & (BROADCAST | NETWORK | NETPREFIX)) {
-               if (argc > 2 || argc <= 0)
-                       bb_show_usage();
-       } else {
-               if (argc != 1)
+       if (opt & SILENT)
+               logmode = LOGMODE_NONE; /* suppress error_msg() output */
+       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();
        }
 
@@ -111,17 +160,12 @@ int ipcalc_main(int argc, char **argv)
 
                prefixstr = ipstr;
 
-               while(*prefixstr) {
+               while (*prefixstr) {
                        if (*prefixstr == '/') {
-                               *prefixstr = (char)0;
-                               prefixstr++;
+                               *prefixstr++ = '\0';
                                if (*prefixstr) {
-                                       unsigned int msk;
-
-                                       if (safe_strtoul(prefixstr, &netprefix) || netprefix > 32) {
-                                               IPCALC_MSG(bb_error_msg_and_die("bad IP prefix: %s\n", prefixstr),
-                                                               exit(EXIT_FAILURE));
-                                       }
+                                       unsigned msk;
+                                       netprefix = xatoul_range(prefixstr, 0, 32);
                                        netmask = 0;
                                        msk = 0x80000000;
                                        while (netprefix > 0) {
@@ -139,65 +183,51 @@ int ipcalc_main(int argc, char **argv)
                        prefixstr++;
                }
        }
-       ipaddr = inet_aton(ipstr, &a);
 
-       if (ipaddr == 0) {
-               IPCALC_MSG(bb_error_msg_and_die("bad IP address: %s", argv[0]),
-                               exit(EXIT_FAILURE));
+       if (inet_aton(ipstr, &s_ipaddr) == 0) {
+               bb_error_msg_and_die("bad IP address: %s", argv[0]);
        }
-       ipaddr = a.s_addr;
 
-       if (argc == 2) {
+       if (argv[1]) {
                if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
-                       IPCALC_MSG(bb_error_msg_and_die("Use prefix or netmask, not both.\n"),
-                                       exit(EXIT_FAILURE));
+                       bb_error_msg_and_die("use prefix or netmask, not both");
                }
-
-               netmask = inet_aton(argv[1], &a);
-               if (netmask == 0) {
-                       IPCALC_MSG(bb_error_msg_and_die("bad netmask: %s", argv[1]),
-                                       exit(EXIT_FAILURE));
+               if (inet_aton(argv[1], &s_netmask) == 0) {
+                       bb_error_msg_and_die("bad netmask: %s", argv[1]);
                }
-               netmask = a.s_addr;
        } else {
-
                /* JHC - If the netmask wasn't provided then calculate it */
                if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
                        netmask = get_netmask(ipaddr);
        }
 
-       if (mode & NETMASK) {
-               printf("NETMASK=%s\n", inet_ntoa((*(struct in_addr *) &netmask)));
+       if (opt & NETMASK) {
+               printf("NETMASK=%s\n", inet_ntoa(s_netmask));
        }
 
-       if (mode & BROADCAST) {
+       if (opt & BROADCAST) {
                broadcast = (ipaddr & netmask) | ~netmask;
-               printf("BROADCAST=%s\n", inet_ntoa((*(struct in_addr *) &broadcast)));
+               printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
        }
 
-       if (mode & NETWORK) {
+       if (opt & NETWORK) {
                network = ipaddr & netmask;
-               printf("NETWORK=%s\n", inet_ntoa((*(struct in_addr *) &network)));
+               printf("NETWORK=%s\n", inet_ntoa(s_network));
        }
 
        if (ENABLE_FEATURE_IPCALC_FANCY) {
-               if (mode & NETPREFIX) {
+               if (opt & NETPREFIX) {
                        printf("PREFIX=%i\n", get_prefix(netmask));
                }
 
-               if (mode & HOSTNAME) {
+               if (opt & HOSTNAME) {
                        struct hostent *hostinfo;
-                       int x;
 
                        hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
                        if (!hostinfo) {
-                               IPCALC_MSG(bb_herror_msg_and_die(
-                                                       "cannot find hostname for %s", argv[0]),);
-                               exit(EXIT_FAILURE);
-                       }
-                       for (x = 0; hostinfo->h_name[x]; x++) {
-                               hostinfo->h_name[x] = tolower(hostinfo->h_name[x]);
+                               bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
                        }
+                       str_tolower(hostinfo->h_name);
 
                        printf("HOSTNAME=%s\n", hostinfo->h_name);
                }