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1/* vi: set sw=4 ts=4: */
2/*
3 * Mini ipcalc implementation for busybox
4 *
5 * By Jordan Crouse <jordan@cosmicpenguin.net>
6 * Stephan Linz <linz@li-pro.net>
7 *
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
11 *
12 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
13 */
14//config:config IPCALC
15//config: bool "ipcalc"
16//config: default y
17//config: help
18//config: ipcalc takes an IP address and netmask and calculates the
19//config: resulting broadcast, network, and host range.
20//config:
21//config:config FEATURE_IPCALC_FANCY
22//config: bool "Fancy IPCALC, more options, adds 1 kbyte"
23//config: default y
24//config: depends on IPCALC
25//config: help
26//config: Adds the options hostname, prefix and silent to the output of
27//config: "ipcalc".
28//config:
29//config:config FEATURE_IPCALC_LONG_OPTIONS
30//config: bool "Enable long options"
31//config: default y
32//config: depends on IPCALC && LONG_OPTS
33//config: help
34//config: Support long options for the ipcalc applet.
35
36//applet:IF_IPCALC(APPLET(ipcalc, BB_DIR_BIN, BB_SUID_DROP))
37
38//kbuild:lib-$(CONFIG_IPCALC) += ipcalc.o
39
40//usage:#define ipcalc_trivial_usage
41//usage: "[OPTIONS] ADDRESS"
42//usage: IF_FEATURE_IPCALC_FANCY("[/PREFIX]") " [NETMASK]"
43//usage:#define ipcalc_full_usage "\n\n"
44//usage: "Calculate IP network settings from a IP address\n"
45//usage: IF_FEATURE_IPCALC_LONG_OPTIONS(
46//usage: "\n -b,--broadcast Display calculated broadcast address"
47//usage: "\n -n,--network Display calculated network address"
48//usage: "\n -m,--netmask Display default netmask for IP"
49//usage: IF_FEATURE_IPCALC_FANCY(
50//usage: "\n -p,--prefix Display the prefix for IP/NETMASK"
51//usage: "\n -h,--hostname Display first resolved host name"
52//usage: "\n -s,--silent Don't ever display error messages"
53//usage: )
54//usage: )
55//usage: IF_NOT_FEATURE_IPCALC_LONG_OPTIONS(
56//usage: "\n -b Display calculated broadcast address"
57//usage: "\n -n Display calculated network address"
58//usage: "\n -m Display default netmask for IP"
59//usage: IF_FEATURE_IPCALC_FANCY(
60//usage: "\n -p Display the prefix for IP/NETMASK"
61//usage: "\n -h Display first resolved host name"
62//usage: "\n -s Don't ever display error messages"
63//usage: )
64//usage: )
65
66#include "libbb.h"
67/* After libbb.h, because on some systems it needs other includes */
68#include <arpa/inet.h>
69
70#define CLASS_A_NETMASK ntohl(0xFF000000)
71#define CLASS_B_NETMASK ntohl(0xFFFF0000)
72#define CLASS_C_NETMASK ntohl(0xFFFFFF00)
73
74static unsigned long get_netmask(unsigned long ipaddr)
75{
76 ipaddr = htonl(ipaddr);
77
78 if ((ipaddr & 0xC0000000) == 0xC0000000)
79 return CLASS_C_NETMASK;
80 else if ((ipaddr & 0x80000000) == 0x80000000)
81 return CLASS_B_NETMASK;
82 else if ((ipaddr & 0x80000000) == 0)
83 return CLASS_A_NETMASK;
84 else
85 return 0;
86}
87
88#if ENABLE_FEATURE_IPCALC_FANCY
89static int get_prefix(unsigned long netmask)
90{
91 unsigned long msk = 0x80000000;
92 int ret = 0;
93
94 netmask = htonl(netmask);
95 while (msk) {
96 if (netmask & msk)
97 ret++;
98 msk >>= 1;
99 }
100 return ret;
101}
102#else
103int get_prefix(unsigned long netmask);
104#endif
105
106
107#define NETMASK 0x01
108#define BROADCAST 0x02
109#define NETWORK 0x04
110#define NETPREFIX 0x08
111#define HOSTNAME 0x10
112#define SILENT 0x20
113
114#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
115 static const char ipcalc_longopts[] ALIGN1 =
116 "netmask\0" No_argument "m" // netmask from IP (assuming complete class A, B, or C network)
117 "broadcast\0" No_argument "b" // broadcast from IP [netmask]
118 "network\0" No_argument "n" // network from IP [netmask]
119# if ENABLE_FEATURE_IPCALC_FANCY
120 "prefix\0" No_argument "p" // prefix from IP[/prefix] [netmask]
121 "hostname\0" No_argument "h" // hostname from IP
122 "silent\0" No_argument "s" // don’t ever display error messages
123# endif
124 ;
125#endif
126
127int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
128int ipcalc_main(int argc UNUSED_PARAM, char **argv)
129{
130 unsigned opt;
131 bool have_netmask = 0;
132 struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
133 /* struct in_addr { in_addr_t s_addr; } and in_addr_t
134 * (which in turn is just a typedef to uint32_t)
135 * are essentially the same type. A few macros for less verbosity: */
136#define netmask (s_netmask.s_addr)
137#define broadcast (s_broadcast.s_addr)
138#define network (s_network.s_addr)
139#define ipaddr (s_ipaddr.s_addr)
140 char *ipstr;
141
142#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
143 applet_long_options = ipcalc_longopts;
144#endif
145 opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
146 opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
147 argv += optind;
148 if (opt & SILENT)
149 logmode = LOGMODE_NONE; /* suppress error_msg() output */
150 opt &= ~SILENT;
151 if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
152 /* if no options at all or
153 * (no broadcast,network,prefix) and (two args)... */
154 if (!opt || argv[1])
155 bb_show_usage();
156 }
157
158 ipstr = argv[0];
159 if (ENABLE_FEATURE_IPCALC_FANCY) {
160 unsigned long netprefix = 0;
161 char *prefixstr;
162
163 prefixstr = ipstr;
164
165 while (*prefixstr) {
166 if (*prefixstr == '/') {
167 *prefixstr++ = '\0';
168 if (*prefixstr) {
169 unsigned msk;
170 netprefix = xatoul_range(prefixstr, 0, 32);
171 netmask = 0;
172 msk = 0x80000000;
173 while (netprefix > 0) {
174 netmask |= msk;
175 msk >>= 1;
176 netprefix--;
177 }
178 netmask = htonl(netmask);
179 /* Even if it was 0, we will signify that we have a netmask. This allows */
180 /* for specification of default routes, etc which have a 0 netmask/prefix */
181 have_netmask = 1;
182 }
183 break;
184 }
185 prefixstr++;
186 }
187 }
188
189 if (inet_aton(ipstr, &s_ipaddr) == 0) {
190 bb_error_msg_and_die("bad IP address: %s", argv[0]);
191 }
192
193 if (argv[1]) {
194 if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
195 bb_error_msg_and_die("use prefix or netmask, not both");
196 }
197 if (inet_aton(argv[1], &s_netmask) == 0) {
198 bb_error_msg_and_die("bad netmask: %s", argv[1]);
199 }
200 } else {
201 /* JHC - If the netmask wasn't provided then calculate it */
202 if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
203 netmask = get_netmask(ipaddr);
204 }
205
206 if (opt & NETMASK) {
207 printf("NETMASK=%s\n", inet_ntoa(s_netmask));
208 }
209
210 if (opt & BROADCAST) {
211 broadcast = (ipaddr & netmask) | ~netmask;
212 printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
213 }
214
215 if (opt & NETWORK) {
216 network = ipaddr & netmask;
217 printf("NETWORK=%s\n", inet_ntoa(s_network));
218 }
219
220 if (ENABLE_FEATURE_IPCALC_FANCY) {
221 if (opt & NETPREFIX) {
222 printf("PREFIX=%i\n", get_prefix(netmask));
223 }
224
225 if (opt & HOSTNAME) {
226 struct hostent *hostinfo;
227
228 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
229 if (!hostinfo) {
230 bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
231 }
232 str_tolower(hostinfo->h_name);
233
234 printf("HOSTNAME=%s\n", hostinfo->h_name);
235 }
236 }
237
238 return EXIT_SUCCESS;
239}
240
generated by cgit at 2024-05-15 16:03:07 (GMT)