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 tarball for details.
15 #include <sys/socket.h>
16 #include <arpa/inet.h>
20 #define CLASS_A_NETMASK ntohl(0xFF000000)
21 #define CLASS_B_NETMASK ntohl(0xFFFF0000)
22 #define CLASS_C_NETMASK ntohl(0xFFFFFF00)
24 static unsigned long get_netmask(unsigned long ipaddr)
26 ipaddr = htonl(ipaddr);
28 if ((ipaddr & 0xC0000000) == 0xC0000000)
29 return CLASS_C_NETMASK;
30 else if ((ipaddr & 0x80000000) == 0x80000000)
31 return CLASS_B_NETMASK;
32 else if ((ipaddr & 0x80000000) == 0)
33 return CLASS_A_NETMASK;
38 #if ENABLE_FEATURE_IPCALC_FANCY
39 static int get_prefix(unsigned long netmask)
41 unsigned long msk = 0x80000000;
44 netmask = htonl(netmask);
53 int get_prefix(unsigned long netmask);
58 #define BROADCAST 0x02
60 #define NETPREFIX 0x08
64 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
65 static const char ipcalc_longopts[] ALIGN1 =
66 "netmask\0" No_argument "m" // netmask from IP (assuming complete class A, B, or C network)
67 "broadcast\0" No_argument "b" // broadcast from IP [netmask]
68 "network\0" No_argument "n" // network from IP [netmask]
69 # if ENABLE_FEATURE_IPCALC_FANCY
70 "prefix\0" No_argument "p" // prefix from IP[/prefix] [netmask]
71 "hostname\0" No_argument "h" // hostname from IP
72 "silent\0" No_argument "s" // don’t ever display error messages
77 int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
78 int ipcalc_main(int argc UNUSED_PARAM, char **argv)
81 bool have_netmask = 0;
82 struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
83 /* struct in_addr { in_addr_t s_addr; } and in_addr_t
84 * (which in turn is just a typedef to uint32_t)
85 * are essentially the same type. A few macros for less verbosity: */
86 #define netmask (s_netmask.s_addr)
87 #define broadcast (s_broadcast.s_addr)
88 #define network (s_network.s_addr)
89 #define ipaddr (s_ipaddr.s_addr)
92 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
93 applet_long_options = ipcalc_longopts;
95 opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
96 opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
99 logmode = LOGMODE_NONE; /* suppress error_msg() output */
101 if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
102 /* if no options at all or
103 * (no broadcast,network,prefix) and (two args)... */
109 if (ENABLE_FEATURE_IPCALC_FANCY) {
110 unsigned long netprefix = 0;
116 if (*prefixstr == '/') {
120 netprefix = xatoul_range(prefixstr, 0, 32);
123 while (netprefix > 0) {
128 netmask = htonl(netmask);
129 /* Even if it was 0, we will signify that we have a netmask. This allows */
130 /* for specification of default routes, etc which have a 0 netmask/prefix */
139 if (inet_aton(ipstr, &s_ipaddr) == 0) {
140 bb_error_msg_and_die("bad IP address: %s", argv[0]);
144 if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
145 bb_error_msg_and_die("use prefix or netmask, not both");
147 if (inet_aton(argv[1], &s_netmask) == 0) {
148 bb_error_msg_and_die("bad netmask: %s", argv[1]);
151 /* JHC - If the netmask wasn't provided then calculate it */
152 if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
153 netmask = get_netmask(ipaddr);
157 printf("NETMASK=%s\n", inet_ntoa(s_netmask));
160 if (opt & BROADCAST) {
161 broadcast = (ipaddr & netmask) | ~netmask;
162 printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
166 network = ipaddr & netmask;
167 printf("NETWORK=%s\n", inet_ntoa(s_network));
170 if (ENABLE_FEATURE_IPCALC_FANCY) {
171 if (opt & NETPREFIX) {
172 printf("PREFIX=%i\n", get_prefix(netmask));
175 if (opt & HOSTNAME) {
176 struct hostent *hostinfo;
178 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
180 bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
182 str_tolower(hostinfo->h_name);
184 printf("HOSTNAME=%s\n", hostinfo->h_name);