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.
16 #include <sys/socket.h>
17 #include <arpa/inet.h>
21 #define CLASS_A_NETMASK ntohl(0xFF000000)
22 #define CLASS_B_NETMASK ntohl(0xFFFF0000)
23 #define CLASS_C_NETMASK ntohl(0xFFFFFF00)
25 static unsigned long get_netmask(unsigned long ipaddr)
27 ipaddr = htonl(ipaddr);
29 if ((ipaddr & 0xC0000000) == 0xC0000000)
30 return CLASS_C_NETMASK;
31 else if ((ipaddr & 0x80000000) == 0x80000000)
32 return CLASS_B_NETMASK;
33 else if ((ipaddr & 0x80000000) == 0)
34 return CLASS_A_NETMASK;
39 #if ENABLE_FEATURE_IPCALC_FANCY
40 static int get_prefix(unsigned long netmask)
42 unsigned long msk = 0x80000000;
45 netmask = htonl(netmask);
54 int get_prefix(unsigned long netmask);
59 #define BROADCAST 0x02
61 #define NETPREFIX 0x08
65 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
66 static const char ipcalc_longopts[] ALIGN1 =
67 "netmask\0" No_argument "m"
68 "broadcast\0" No_argument "b"
69 "network\0" No_argument "n"
70 # if ENABLE_FEATURE_IPCALC_FANCY
71 "prefix\0" No_argument "p"
72 "hostname\0" No_argument "h"
73 "silent\0" No_argument "s"
78 int ipcalc_main(int argc, char **argv);
79 int ipcalc_main(int argc, char **argv)
83 in_addr_t netmask, broadcast, network, ipaddr;
87 #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
88 applet_long_options = ipcalc_longopts;
90 opt = getopt32(argv, "mbn" USE_FEATURE_IPCALC_FANCY("phs"));
93 if (opt & (BROADCAST | NETWORK | NETPREFIX)) {
94 if (argc > 2 || argc <= 0)
101 logmode = LOGMODE_NONE; /* Suppress error_msg() output */
104 if (ENABLE_FEATURE_IPCALC_FANCY) {
105 unsigned long netprefix = 0;
111 if (*prefixstr == '/') {
112 *prefixstr = (char)0;
116 netprefix = xatoul_range(prefixstr, 0, 32);
119 while (netprefix > 0) {
124 netmask = htonl(netmask);
125 /* Even if it was 0, we will signify that we have a netmask. This allows */
126 /* for specification of default routes, etc which have a 0 netmask/prefix */
134 ipaddr = inet_aton(ipstr, &a);
137 bb_error_msg_and_die("bad IP address: %s", argv[0]);
142 if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
143 bb_error_msg_and_die("use prefix or netmask, not both");
146 netmask = inet_aton(argv[1], &a);
148 bb_error_msg_and_die("bad netmask: %s", argv[1]);
153 /* JHC - If the netmask wasn't provided then calculate it */
154 if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
155 netmask = get_netmask(ipaddr);
159 printf("NETMASK=%s\n", inet_ntoa((*(struct in_addr *) &netmask)));
162 if (opt & BROADCAST) {
163 broadcast = (ipaddr & netmask) | ~netmask;
164 printf("BROADCAST=%s\n", inet_ntoa((*(struct in_addr *) &broadcast)));
168 network = ipaddr & netmask;
169 printf("NETWORK=%s\n", inet_ntoa((*(struct in_addr *) &network)));
172 if (ENABLE_FEATURE_IPCALC_FANCY) {
173 if (opt & NETPREFIX) {
174 printf("PREFIX=%i\n", get_prefix(netmask));
177 if (opt & HOSTNAME) {
178 struct hostent *hostinfo;
181 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
183 bb_herror_msg_and_die("cannot find hostname for %s", argv[0]);
185 for (x = 0; hostinfo->h_name[x]; x++) {
186 hostinfo->h_name[x] = tolower(hostinfo->h_name[x]);
189 printf("HOSTNAME=%s\n", hostinfo->h_name);