Contents of /tags/mkinitrd-6_5_1/busybox/networking/ipcalc.c
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Wed Sep 7 17:51:16 2011 UTC (13 years ago) by niro
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Wed Sep 7 17:51:16 2011 UTC (13 years ago) by niro
File MIME type: text/plain
File size: 4956 byte(s)
tagged 'mkinitrd-6_5_1'
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 tarball for details. |
13 | */ |
14 | #include "libbb.h" |
15 | /* After libbb.h, because on some systems it needs other includes */ |
16 | #include <arpa/inet.h> |
17 | |
18 | #define CLASS_A_NETMASK ntohl(0xFF000000) |
19 | #define CLASS_B_NETMASK ntohl(0xFFFF0000) |
20 | #define CLASS_C_NETMASK ntohl(0xFFFFFF00) |
21 | |
22 | static unsigned long get_netmask(unsigned long ipaddr) |
23 | { |
24 | ipaddr = htonl(ipaddr); |
25 | |
26 | if ((ipaddr & 0xC0000000) == 0xC0000000) |
27 | return CLASS_C_NETMASK; |
28 | else if ((ipaddr & 0x80000000) == 0x80000000) |
29 | return CLASS_B_NETMASK; |
30 | else if ((ipaddr & 0x80000000) == 0) |
31 | return CLASS_A_NETMASK; |
32 | else |
33 | return 0; |
34 | } |
35 | |
36 | #if ENABLE_FEATURE_IPCALC_FANCY |
37 | static int get_prefix(unsigned long netmask) |
38 | { |
39 | unsigned long msk = 0x80000000; |
40 | int ret = 0; |
41 | |
42 | netmask = htonl(netmask); |
43 | while (msk) { |
44 | if (netmask & msk) |
45 | ret++; |
46 | msk >>= 1; |
47 | } |
48 | return ret; |
49 | } |
50 | #else |
51 | int get_prefix(unsigned long netmask); |
52 | #endif |
53 | |
54 | |
55 | #define NETMASK 0x01 |
56 | #define BROADCAST 0x02 |
57 | #define NETWORK 0x04 |
58 | #define NETPREFIX 0x08 |
59 | #define HOSTNAME 0x10 |
60 | #define SILENT 0x20 |
61 | |
62 | #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS |
63 | static const char ipcalc_longopts[] ALIGN1 = |
64 | "netmask\0" No_argument "m" // netmask from IP (assuming complete class A, B, or C network) |
65 | "broadcast\0" No_argument "b" // broadcast from IP [netmask] |
66 | "network\0" No_argument "n" // network from IP [netmask] |
67 | # if ENABLE_FEATURE_IPCALC_FANCY |
68 | "prefix\0" No_argument "p" // prefix from IP[/prefix] [netmask] |
69 | "hostname\0" No_argument "h" // hostname from IP |
70 | "silent\0" No_argument "s" // don’t ever display error messages |
71 | # endif |
72 | ; |
73 | #endif |
74 | |
75 | int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
76 | int ipcalc_main(int argc UNUSED_PARAM, char **argv) |
77 | { |
78 | unsigned opt; |
79 | bool have_netmask = 0; |
80 | struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr; |
81 | /* struct in_addr { in_addr_t s_addr; } and in_addr_t |
82 | * (which in turn is just a typedef to uint32_t) |
83 | * are essentially the same type. A few macros for less verbosity: */ |
84 | #define netmask (s_netmask.s_addr) |
85 | #define broadcast (s_broadcast.s_addr) |
86 | #define network (s_network.s_addr) |
87 | #define ipaddr (s_ipaddr.s_addr) |
88 | char *ipstr; |
89 | |
90 | #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS |
91 | applet_long_options = ipcalc_longopts; |
92 | #endif |
93 | opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */ |
94 | opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs")); |
95 | argv += optind; |
96 | if (opt & SILENT) |
97 | logmode = LOGMODE_NONE; /* suppress error_msg() output */ |
98 | opt &= ~SILENT; |
99 | if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) { |
100 | /* if no options at all or |
101 | * (no broadcast,network,prefix) and (two args)... */ |
102 | if (!opt || argv[1]) |
103 | bb_show_usage(); |
104 | } |
105 | |
106 | ipstr = argv[0]; |
107 | if (ENABLE_FEATURE_IPCALC_FANCY) { |
108 | unsigned long netprefix = 0; |
109 | char *prefixstr; |
110 | |
111 | prefixstr = ipstr; |
112 | |
113 | while (*prefixstr) { |
114 | if (*prefixstr == '/') { |
115 | *prefixstr++ = '\0'; |
116 | if (*prefixstr) { |
117 | unsigned msk; |
118 | netprefix = xatoul_range(prefixstr, 0, 32); |
119 | netmask = 0; |
120 | msk = 0x80000000; |
121 | while (netprefix > 0) { |
122 | netmask |= msk; |
123 | msk >>= 1; |
124 | netprefix--; |
125 | } |
126 | netmask = htonl(netmask); |
127 | /* Even if it was 0, we will signify that we have a netmask. This allows */ |
128 | /* for specification of default routes, etc which have a 0 netmask/prefix */ |
129 | have_netmask = 1; |
130 | } |
131 | break; |
132 | } |
133 | prefixstr++; |
134 | } |
135 | } |
136 | |
137 | if (inet_aton(ipstr, &s_ipaddr) == 0) { |
138 | bb_error_msg_and_die("bad IP address: %s", argv[0]); |
139 | } |
140 | |
141 | if (argv[1]) { |
142 | if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) { |
143 | bb_error_msg_and_die("use prefix or netmask, not both"); |
144 | } |
145 | if (inet_aton(argv[1], &s_netmask) == 0) { |
146 | bb_error_msg_and_die("bad netmask: %s", argv[1]); |
147 | } |
148 | } else { |
149 | /* JHC - If the netmask wasn't provided then calculate it */ |
150 | if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask) |
151 | netmask = get_netmask(ipaddr); |
152 | } |
153 | |
154 | if (opt & NETMASK) { |
155 | printf("NETMASK=%s\n", inet_ntoa(s_netmask)); |
156 | } |
157 | |
158 | if (opt & BROADCAST) { |
159 | broadcast = (ipaddr & netmask) | ~netmask; |
160 | printf("BROADCAST=%s\n", inet_ntoa(s_broadcast)); |
161 | } |
162 | |
163 | if (opt & NETWORK) { |
164 | network = ipaddr & netmask; |
165 | printf("NETWORK=%s\n", inet_ntoa(s_network)); |
166 | } |
167 | |
168 | if (ENABLE_FEATURE_IPCALC_FANCY) { |
169 | if (opt & NETPREFIX) { |
170 | printf("PREFIX=%i\n", get_prefix(netmask)); |
171 | } |
172 | |
173 | if (opt & HOSTNAME) { |
174 | struct hostent *hostinfo; |
175 | |
176 | hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET); |
177 | if (!hostinfo) { |
178 | bb_herror_msg_and_die("can't find hostname for %s", argv[0]); |
179 | } |
180 | str_tolower(hostinfo->h_name); |
181 | |
182 | printf("HOSTNAME=%s\n", hostinfo->h_name); |
183 | } |
184 | } |
185 | |
186 | return EXIT_SUCCESS; |
187 | } |