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    Annotation of /tags/mkinitrd-6_3_1/busybox/networking/ipcalc.c

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    Revision 1123 - (hide annotations) (download)
    Wed Aug 18 21:56:57 2010 UTC (13 years, 10 months ago) by niro
    Original Path: trunk/mkinitrd-magellan/busybox/networking/ipcalc.c
    File MIME type: text/plain
    File size: 4956 byte(s) 
    -updated to busybox-1.17.1
    1 niro 532 /* 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 niro 1123 #include "libbb.h"
    15     /* After libbb.h, because on some systems it needs other includes */
    16 niro 532 #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 niro 816 #if ENABLE_FEATURE_IPCALC_FANCY
    37 niro 532 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 niro 816 static const char ipcalc_longopts[] ALIGN1 =
    64 niro 1123 "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 niro 532 # if ENABLE_FEATURE_IPCALC_FANCY
    68 niro 1123 "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 niro 532 # endif
    72 niro 816 ;
    73 niro 532 #endif
    74    
    75 niro 816 int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
    76 niro 1123 int ipcalc_main(int argc UNUSED_PARAM, char **argv)
    77 niro 532 {
    78     unsigned opt;
    79 niro 1123 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 niro 532 char *ipstr;
    89    
    90     #if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
    91 niro 816 applet_long_options = ipcalc_longopts;
    92 niro 532 #endif
    93 niro 1123 opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
    94 niro 984 opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
    95 niro 532 argv += optind;
    96 niro 1123 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 niro 532 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 niro 1123 *prefixstr++ = '\0';
    116 niro 532 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 niro 1123 if (inet_aton(ipstr, &s_ipaddr) == 0) {
    138 niro 532 bb_error_msg_and_die("bad IP address: %s", argv[0]);
    139     }
    140    
    141 niro 1123 if (argv[1]) {
    142 niro 532 if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
    143     bb_error_msg_and_die("use prefix or netmask, not both");
    144     }
    145 niro 1123 if (inet_aton(argv[1], &s_netmask) == 0) {
    146 niro 532 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 niro 1123 printf("NETMASK=%s\n", inet_ntoa(s_netmask));
    156 niro 532 }
    157    
    158     if (opt & BROADCAST) {
    159     broadcast = (ipaddr & netmask) | ~netmask;
    160 niro 1123 printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
    161 niro 532 }
    162    
    163     if (opt & NETWORK) {
    164     network = ipaddr & netmask;
    165 niro 1123 printf("NETWORK=%s\n", inet_ntoa(s_network));
    166 niro 532 }
    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 niro 984 bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
    179 niro 532 }
    180 niro 816 str_tolower(hostinfo->h_name);
    181 niro 532
    182     printf("HOSTNAME=%s\n", hostinfo->h_name);
    183     }
    184     }
    185    
    186     return EXIT_SUCCESS;
    187     }