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/* vi: set sw=4 ts=4: */
/*
* Mini ipcalc implementation for busybox
*
* By Jordan Crouse <jordan@cosmicpenguin.net>
* Stephan Linz <linz@li-pro.net>
*
* This is a complete reimplementation of the ipcalc program
* from Red Hat. I didn't look at their source code, but there
* is no denying that this is a loving reimplementation
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
/* After libbb.h, because on some systems it needs other includes */
#include <arpa/inet.h>
#define CLASS_A_NETMASK ntohl(0xFF000000)
#define CLASS_B_NETMASK ntohl(0xFFFF0000)
#define CLASS_C_NETMASK ntohl(0xFFFFFF00)
static unsigned long get_netmask(unsigned long ipaddr)
{
ipaddr = htonl(ipaddr);
if ((ipaddr & 0xC0000000) == 0xC0000000)
return CLASS_C_NETMASK;
else if ((ipaddr & 0x80000000) == 0x80000000)
return CLASS_B_NETMASK;
else if ((ipaddr & 0x80000000) == 0)
return CLASS_A_NETMASK;
else
return 0;
}
#if ENABLE_FEATURE_IPCALC_FANCY
static int get_prefix(unsigned long netmask)
{
unsigned long msk = 0x80000000;
int ret = 0;
netmask = htonl(netmask);
while (msk) {
if (netmask & msk)
ret++;
msk >>= 1;
}
return ret;
}
#else
int get_prefix(unsigned long netmask);
#endif
#define NETMASK 0x01
#define BROADCAST 0x02
#define NETWORK 0x04
#define NETPREFIX 0x08
#define HOSTNAME 0x10
#define SILENT 0x20
#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
static const char ipcalc_longopts[] ALIGN1 =
"netmask\0" No_argument "m" // netmask from IP (assuming complete class A, B, or C network)
"broadcast\0" No_argument "b" // broadcast from IP [netmask]
"network\0" No_argument "n" // network from IP [netmask]
# if ENABLE_FEATURE_IPCALC_FANCY
"prefix\0" No_argument "p" // prefix from IP[/prefix] [netmask]
"hostname\0" No_argument "h" // hostname from IP
"silent\0" No_argument "s" // don’t ever display error messages
# endif
;
#endif
int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ipcalc_main(int argc UNUSED_PARAM, char **argv)
{
unsigned opt;
bool have_netmask = 0;
struct in_addr s_netmask, s_broadcast, s_network, s_ipaddr;
/* struct in_addr { in_addr_t s_addr; } and in_addr_t
* (which in turn is just a typedef to uint32_t)
* are essentially the same type. A few macros for less verbosity: */
#define netmask (s_netmask.s_addr)
#define broadcast (s_broadcast.s_addr)
#define network (s_network.s_addr)
#define ipaddr (s_ipaddr.s_addr)
char *ipstr;
#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS
applet_long_options = ipcalc_longopts;
#endif
opt_complementary = "-1:?2"; /* minimum 1 arg, maximum 2 args */
opt = getopt32(argv, "mbn" IF_FEATURE_IPCALC_FANCY("phs"));
argv += optind;
if (opt & SILENT)
logmode = LOGMODE_NONE; /* suppress error_msg() output */
opt &= ~SILENT;
if (!(opt & (BROADCAST | NETWORK | NETPREFIX))) {
/* if no options at all or
* (no broadcast,network,prefix) and (two args)... */
if (!opt || argv[1])
bb_show_usage();
}
ipstr = argv[0];
if (ENABLE_FEATURE_IPCALC_FANCY) {
unsigned long netprefix = 0;
char *prefixstr;
prefixstr = ipstr;
while (*prefixstr) {
if (*prefixstr == '/') {
*prefixstr++ = '\0';
if (*prefixstr) {
unsigned msk;
netprefix = xatoul_range(prefixstr, 0, 32);
netmask = 0;
msk = 0x80000000;
while (netprefix > 0) {
netmask |= msk;
msk >>= 1;
netprefix--;
}
netmask = htonl(netmask);
/* Even if it was 0, we will signify that we have a netmask. This allows */
/* for specification of default routes, etc which have a 0 netmask/prefix */
have_netmask = 1;
}
break;
}
prefixstr++;
}
}
if (inet_aton(ipstr, &s_ipaddr) == 0) {
bb_error_msg_and_die("bad IP address: %s", argv[0]);
}
if (argv[1]) {
if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) {
bb_error_msg_and_die("use prefix or netmask, not both");
}
if (inet_aton(argv[1], &s_netmask) == 0) {
bb_error_msg_and_die("bad netmask: %s", argv[1]);
}
} else {
/* JHC - If the netmask wasn't provided then calculate it */
if (!ENABLE_FEATURE_IPCALC_FANCY || !have_netmask)
netmask = get_netmask(ipaddr);
}
if (opt & NETMASK) {
printf("NETMASK=%s\n", inet_ntoa(s_netmask));
}
if (opt & BROADCAST) {
broadcast = (ipaddr & netmask) | ~netmask;
printf("BROADCAST=%s\n", inet_ntoa(s_broadcast));
}
if (opt & NETWORK) {
network = ipaddr & netmask;
printf("NETWORK=%s\n", inet_ntoa(s_network));
}
if (ENABLE_FEATURE_IPCALC_FANCY) {
if (opt & NETPREFIX) {
printf("PREFIX=%i\n", get_prefix(netmask));
}
if (opt & HOSTNAME) {
struct hostent *hostinfo;
hostinfo = gethostbyaddr((char *) &ipaddr, sizeof(ipaddr), AF_INET);
if (!hostinfo) {
bb_herror_msg_and_die("can't find hostname for %s", argv[0]);
}
str_tolower(hostinfo->h_name);
printf("HOSTNAME=%s\n", hostinfo->h_name);
}
}
return EXIT_SUCCESS;
}
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