1 /* vi: set sw=4 ts=4: */
3 * Mini ipcalc implementation for busybox
5 * By Jordan Crouse <jordan@cosmicpenguin.net>
6 * Stephan Linz <linz@li-pro.net>
8 * This is a complete reimplementation of the ipcalc program
9 * from Red Hat. I didn't look at their source code, but there
10 * is no denying that this is a loving reimplementation
12 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
14 //config:config IPCALC
15 //config: bool "ipcalc"
18 //config: ipcalc takes an IP address and netmask and calculates the
19 //config: resulting broadcast, network, and host range.
21 //config:config FEATURE_IPCALC_LONG_OPTIONS
22 //config: bool "Enable long options"
24 //config: depends on IPCALC && LONG_OPTS
26 //config:config FEATURE_IPCALC_FANCY
27 //config: bool "Fancy IPCALC, more options, adds 1 kbyte"
29 //config: depends on IPCALC
31 //config: Adds the options hostname, prefix and silent to the output of
34 //applet:IF_IPCALC(APPLET(ipcalc, BB_DIR_BIN, BB_SUID_DROP))
36 //kbuild:lib-$(CONFIG_IPCALC) += ipcalc.o
38 //usage:#define ipcalc_trivial_usage
39 //usage: "[OPTIONS] ADDRESS"
40 //usage: IF_FEATURE_IPCALC_FANCY("[/PREFIX]") " [NETMASK]"
41 //usage:#define ipcalc_full_usage "\n\n"
42 //usage: "Calculate IP network settings from a IP address\n"
43 //usage: IF_FEATURE_IPCALC_LONG_OPTIONS(
44 //usage: "\n -b,--broadcast Display calculated broadcast address"
45 //usage: "\n -n,--network Display calculated network address"
46 //usage: "\n -m,--netmask Display default netmask for IP"
47 //usage: IF_FEATURE_IPCALC_FANCY(
48 //usage: "\n -p,--prefix Display the prefix for IP/NETMASK"
49 //usage: "\n -h,--hostname Display first resolved host name"
50 //usage: "\n -s,--silent Don't ever display error messages"
53 //usage: IF_NOT_FEATURE_IPCALC_LONG_OPTIONS(
54 //usage: "\n -b Display calculated broadcast address"
55 //usage: "\n -n Display calculated network address"
56 //usage: "\n -m Display default netmask for IP"
57 //usage: IF_FEATURE_IPCALC_FANCY(
58 //usage: "\n -p Display the prefix for IP/NETMASK"
59 //usage: "\n -h Display first resolved host name"
60 //usage: "\n -s Don't ever display error messages"
65 /* After libbb.h, because on some systems it needs other includes */
66 #include <arpa/inet.h>
68 #define CLASS_A_NETMASK ntohl(0xFF000000)
69 #define CLASS_B_NETMASK ntohl(0xFFFF0000)
70 #define CLASS_C_NETMASK ntohl(0xFFFFFF00)
72 static unsigned long get_netmask(unsigned long ipaddr)
74 ipaddr = htonl(ipaddr);
76 if ((ipaddr & 0xC0000000) == 0xC0000000)
77 return CLASS_C_NETMASK;
78 else if ((ipaddr & 0x80000000) == 0x80000000)
79 return CLASS_B_NETMASK;
80 else if ((ipaddr & 0x80000000) == 0)
81 return CLASS_A_NETMASK;
86 #if ENABLE_FEATURE_IPCALC_FANCY
87 static int get_prefix(unsigned long netmask)
89 unsigned long msk = 0x80000000;
92 netmask = htonl(netmask);
101 int get_prefix(unsigned long netmask);
106 #define BROADCAST 0x02
108 #define NETPREFIX 0x08
109 #define HOSTNAME 0x10
112 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
113 static const char ipcalc_longopts[] ALIGN1 =
114 "netmask\0" No_argument "m" // netmask from IP (assuming complete class A, B, or C network)
115 "broadcast\0" No_argument "b" // broadcast from IP [netmask]
116 "network\0" No_argument "n" // network from IP [netmask]
117 # if ENABLE_FEATURE_IPCALC_FANCY
118 "prefix\0" No_argument "p" // prefix from IP[/prefix] [netmask]
119 "hostname\0" No_argument "h" // hostname from IP
120 "silent\0" No_argument "s" // don’t ever display error messages
125 int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
126 int ipcalc_main(int argc UNUSED_PARAM, char **argv)
129 bool have_netmask = 0;
130 struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
131 /* struct in_addr { in_addr_t s_addr; } and in_addr_t
132 * (which in turn is just a typedef to uint32_t)
133 * are essentially the same type. A few macros for less verbosity: */
134 #define netmask (s_netmask.s_addr)
135 #define broadcast (s_broadcast.s_addr)
136 #define network (s_network.s_addr)
137 #define ipaddr (s_ipaddr.s_addr)
140 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
141 applet_long_options = ipcalc_longopts;
143 opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
144 opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
147 logmode = LOGMODE_NONE; /* suppress error_msg() output */
149 if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
150 /* if no options at all or
151 * (no broadcast,network,prefix) and (two args)... */
157 if (ENABLE_FEATURE_IPCALC_FANCY) {
158 unsigned long netprefix = 0;
164 if (*prefixstr == '/') {
168 netprefix = xatoul_range(prefixstr, 0, 32);
171 while (netprefix > 0) {
176 netmask = htonl(netmask);
177 /* Even if it was 0, we will signify that we have a netmask. This allows */
178 /* for specification of default routes, etc which have a 0 netmask/prefix */
187 if (inet_aton(ipstr, &s_ipaddr) == 0) {
188 bb_error_msg_and_die("bad IP address: %s", argv[0]);
192 if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
193 bb_error_msg_and_die("use prefix or netmask, not both");
195 if (inet_aton(argv[1], &s_netmask) == 0) {
196 bb_error_msg_and_die("bad netmask: %s", argv[1]);
199 /* JHC - If the netmask wasn't provided then calculate it */
200 if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
201 netmask = get_netmask(ipaddr);
205 printf("NETMASK=%s\n", inet_ntoa(s_netmask));
208 if (opt & BROADCAST) {
209 broadcast = (ipaddr & netmask) | ~netmask;
210 printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
214 network = ipaddr & netmask;
215 printf("NETWORK=%s\n", inet_ntoa(s_network));
218 if (ENABLE_FEATURE_IPCALC_FANCY) {
219 if (opt & NETPREFIX) {
220 printf("PREFIX=%i\n", get_prefix(netmask));
223 if (opt & HOSTNAME) {
224 struct hostent *hostinfo;
226 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
228 bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
230 str_tolower(hostinfo->h_name);
232 printf("HOSTNAME=%s\n", hostinfo->h_name);