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52#include "libbb.h"
53
54#include <arpa/inet.h>
55
56#define CLASS_A_NETMASK ntohl(0xFF000000)
57#define CLASS_B_NETMASK ntohl(0xFFFF0000)
58#define CLASS_C_NETMASK ntohl(0xFFFFFF00)
59
60static unsigned long get_netmask(unsigned long ipaddr)
61{
62 ipaddr = htonl(ipaddr);
63
64 if ((ipaddr & 0xC0000000) == 0xC0000000)
65 return CLASS_C_NETMASK;
66 else if ((ipaddr & 0x80000000) == 0x80000000)
67 return CLASS_B_NETMASK;
68 else if ((ipaddr & 0x80000000) == 0)
69 return CLASS_A_NETMASK;
70 else
71 return 0;
72}
73
74#if ENABLE_FEATURE_IPCALC_FANCY
75static int get_prefix(unsigned long netmask)
76{
77 unsigned long msk = 0x80000000;
78 int ret = 0;
79
80 netmask = htonl(netmask);
81 while (msk) {
82 if (netmask & msk)
83 ret++;
84 msk >>= 1;
85 }
86 return ret;
87}
88#else
89int get_prefix(unsigned long netmask);
90#endif
91
92
93#define NETMASK 0x01
94#define BROADCAST 0x02
95#define NETWORK 0x04
96#define NETPREFIX 0x08
97#define HOSTNAME 0x10
98#define SILENT 0x20
99
100#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
101 static const char ipcalc_longopts[] ALIGN1 =
102 "netmask\0" No_argument "m"
103 "broadcast\0" No_argument "b"
104 "network\0" No_argument "n"
105# if ENABLE_FEATURE_IPCALC_FANCY
106 "prefix\0" No_argument "p"
107 "hostname\0" No_argument "h"
108 "silent\0" No_argument "s"
109# endif
110 ;
111# define GETOPT32 getopt32long
112# define LONGOPTS ,ipcalc_longopts
113#else
114# define GETOPT32 getopt32
115# define LONGOPTS
116#endif
117
118int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
119int ipcalc_main(int argc UNUSED_PARAM, char **argv)
120{
121 unsigned opt;
122 bool have_netmask = 0;
123 struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
124
125
126
127#define netmask (s_netmask.s_addr)
128#define broadcast (s_broadcast.s_addr)
129#define network (s_network.s_addr)
130#define ipaddr (s_ipaddr.s_addr)
131 char *ipstr;
132
133 opt = GETOPT32(argv, "^"
134 "mbn" IF_FEATURE_IPCALC_FANCY("phs")
135 "\0" "-1:?2"
136 LONGOPTS
137 );
138 argv += optind;
139 if (opt & SILENT)
140 logmode = LOGMODE_NONE;
141 opt &= ~SILENT;
142 if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
143
144
145 if (!opt || argv[1])
146 bb_show_usage();
147 }
148
149 ipstr = argv[0];
150 if (ENABLE_FEATURE_IPCALC_FANCY) {
151 unsigned long netprefix = 0;
152 char *prefixstr;
153
154 prefixstr = ipstr;
155
156 while (*prefixstr) {
157 if (*prefixstr == '/') {
158 *prefixstr++ = '\0';
159 if (*prefixstr) {
160 unsigned msk;
161 netprefix = xatoul_range(prefixstr, 0, 32);
162 netmask = 0;
163 msk = 0x80000000;
164 while (netprefix > 0) {
165 netmask |= msk;
166 msk >>= 1;
167 netprefix--;
168 }
169 netmask = htonl(netmask);
170
171
172 have_netmask = 1;
173 }
174 break;
175 }
176 prefixstr++;
177 }
178 }
179
180 if (inet_aton(ipstr, &s_ipaddr) == 0) {
181 bb_error_msg_and_die("bad IP address: %s", argv[0]);
182 }
183
184 if (argv[1]) {
185 if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
186 bb_error_msg_and_die("use prefix or netmask, not both");
187 }
188 if (inet_aton(argv[1], &s_netmask) == 0) {
189 bb_error_msg_and_die("bad netmask: %s", argv[1]);
190 }
191 } else {
192
193 if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
194 netmask = get_netmask(ipaddr);
195 }
196
197 if (opt & NETMASK) {
198 printf("NETMASK=%s\n", inet_ntoa(s_netmask));
199 }
200
201 if (opt & BROADCAST) {
202 broadcast = (ipaddr & netmask) | ~netmask;
203 printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
204 }
205
206 if (opt & NETWORK) {
207 network = ipaddr & netmask;
208 printf("NETWORK=%s\n", inet_ntoa(s_network));
209 }
210
211 if (ENABLE_FEATURE_IPCALC_FANCY) {
212 if (opt & NETPREFIX) {
213 printf("PREFIX=%i\n", get_prefix(netmask));
214 }
215
216 if (opt & HOSTNAME) {
217 struct hostent *hostinfo;
218
219 hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
220 if (!hostinfo) {
221 bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
222 }
223 str_tolower(hostinfo->h_name);
224
225 printf("HOSTNAME=%s\n", hostinfo->h_name);
226 }
227 }
228
229 return EXIT_SUCCESS;
230}
231