diff options
Diffstat (limited to 'networking/ipcalc.c')
| -rw-r--r-- | networking/ipcalc.c | 190 |
1 files changed, 190 insertions, 0 deletions
diff --git a/networking/ipcalc.c b/networking/ipcalc.c new file mode 100644 index 0000000..d8fa5f3 --- /dev/null +++ b/networking/ipcalc.c @@ -0,0 +1,190 @@ +/* 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 tarball for details. + */ + +#include <sys/socket.h> +#include <arpa/inet.h> + +#include "libbb.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" + "broadcast\0" No_argument "b" + "network\0" No_argument "n" +# if ENABLE_FEATURE_IPCALC_FANCY + "prefix\0" No_argument "p" + "hostname\0" No_argument "h" + "silent\0" No_argument "s" +# endif + ; +#endif + +int ipcalc_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int ipcalc_main(int argc, char **argv) +{ + unsigned opt; + int have_netmask = 0; + in_addr_t netmask, broadcast, network, ipaddr; + struct in_addr a; + char *ipstr; + +#if ENABLE_FEATURE_IPCALC_LONG_OPTIONS + applet_long_options = ipcalc_longopts; +#endif + opt = getopt32(argv, "mbn" USE_FEATURE_IPCALC_FANCY("phs")); + argc -= optind; + argv += optind; + if (opt & (BROADCAST | NETWORK | NETPREFIX)) { + if (argc > 2 || argc <= 0) + bb_show_usage(); + } else { + if (argc != 1) + bb_show_usage(); + } + if (opt & SILENT) + logmode = LOGMODE_NONE; /* Suppress error_msg() output */ + + ipstr = argv[0]; + if (ENABLE_FEATURE_IPCALC_FANCY) { + unsigned long netprefix = 0; + char *prefixstr; + + prefixstr = ipstr; + + while (*prefixstr) { + if (*prefixstr == '/') { + *prefixstr = (char)0; + prefixstr++; + 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++; + } + } + ipaddr = inet_aton(ipstr, &a); + + if (ipaddr == 0) { + bb_error_msg_and_die("bad IP address: %s", argv[0]); + } + ipaddr = a.s_addr; + + if (argc == 2) { + if (ENABLE_FEATURE_IPCALC_FANCY && have_netmask) { + bb_error_msg_and_die("use prefix or netmask, not both"); + } + + netmask = inet_aton(argv[1], &a); + if (netmask == 0) { + bb_error_msg_and_die("bad netmask: %s", argv[1]); + } + netmask = a.s_addr; + } 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((*(struct in_addr *) &netmask))); + } + + if (opt & BROADCAST) { + broadcast = (ipaddr & netmask) | ~netmask; + printf("BROADCAST=%s\n", inet_ntoa((*(struct in_addr *) &broadcast))); + } + + if (opt & NETWORK) { + network = ipaddr & netmask; + printf("NETWORK=%s\n", inet_ntoa((*(struct in_addr *) &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("cannot find hostname for %s", argv[0]); + } + str_tolower(hostinfo->h_name); + + printf("HOSTNAME=%s\n", hostinfo->h_name); + } + } + + return EXIT_SUCCESS; +} |