diff options
| -rw-r--r-- | networking/ipcalc.c | 21 |
1 files changed, 14 insertions, 7 deletions
diff --git a/networking/ipcalc.c b/networking/ipcalc.c index af4eed4a4..94b747ef6 100644 --- a/networking/ipcalc.c +++ b/networking/ipcalc.c @@ -22,15 +22,22 @@ #define IPCALC_MSG(CMD,ALTCMD) if (mode & SILENT) {ALTCMD;} else {CMD;} +#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) { - if (ipaddr & 0xC0) { - return 0x00FFFFFF; /* Class C */ - } - if (ipaddr & 0x10) { - return 0x0000FFFF; /* Class B */ - } - return 0x000000FF; /* Class A */ + 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; } #define NETMASK 0x01 |