diff options
| -rw-r--r-- | src/ipcalc.c | 98 |
1 files changed, 54 insertions, 44 deletions
diff --git a/src/ipcalc.c b/src/ipcalc.c index f97f8bc3..31094be9 100644 --- a/src/ipcalc.c +++ b/src/ipcalc.c @@ -32,18 +32,6 @@ #include <netdb.h> /*! - \def IPBITS - \brief the number of bits in an IP address. -*/ -#define IPBITS (sizeof(u_int32_t) * 8) -/*! - \def IPBYTES - \brief the number of bytes in an IP address. -*/ -#define IPBYTES (sizeof(u_int32_t)) - - -/*! \file ipcalc.c \brief provides utilities for manipulating IP addresses. @@ -61,7 +49,7 @@ */ /*! - \fn u_int32_t prefix2mask(int bits) + \fn struct in_addr prefix2mask(int bits) \brief creates a netmask from a specified number of bits This function converts a prefix length to a netmask. As CIDR (classless @@ -74,26 +62,31 @@ \param prefix is the number of bits to create a mask for. \return a network mask, in network byte order. */ -u_int32_t prefix2mask(int prefix) { - return htonl(~((1 << (32 - prefix)) - 1)); +struct in_addr prefix2mask(int prefix) { + struct in_addr mask; + memset(&mask, 0, sizeof(mask)); + mask.s_addr = htonl(~((1 << (32 - prefix)) - 1)); + return mask; } /*! - \fn int mask2prefix(u_int32_t mask) + \fn int mask2prefix(struct in_addr mask) \brief calculates the number of bits masked off by a netmask. This function calculates the significant bits in an IP address as specified by a netmask. See also \ref prefix2mask. - \param mask is the netmask, specified as an u_int32_teger in network byte order. + \param mask is the netmask, specified as an struct in_addr in network byte order. \return the number of significant bits. */ -int mask2prefix(u_int32_t mask) +int mask2prefix(struct in_addr mask) { int i; - int count = IPBITS; + int ipbits = sizeof(struct in_addr) * 8; + int count = ipbits; + uint32_t saddr = mask.s_addr; - for (i = 0; i < IPBITS; i++) { - if (!(ntohl(mask) & ((2 << i) - 1))) + for (i = 0; i < ipbits; i++) { + if (!(ntohl(saddr) & ((2 << i) - 1))) count--; } @@ -101,7 +94,7 @@ int mask2prefix(u_int32_t mask) } /*! - \fn u_int32_t default_netmask(u_int32_t addr) + \fn struct in_addr default_netmask(struct in_addr addr) \brief returns the default (canonical) netmask associated with specified IP address. @@ -113,18 +106,25 @@ int mask2prefix(u_int32_t mask) \param addr an IP address in network byte order. \return a netmask in network byte order. */ -u_int32_t default_netmask(u_int32_t addr) +struct in_addr default_netmask(struct in_addr addr) { - if (((ntohl(addr) & 0xFF000000) >> 24) <= 127) - return htonl(0xFF000000); - else if (((ntohl(addr) & 0xFF000000) >> 24) <= 191) - return htonl(0xFFFF0000); + uint32_t saddr = addr.s_addr; + struct in_addr mask; + + memset(&mask, 0, sizeof(mask)); + + if (((ntohl(saddr) & 0xFF000000) >> 24) <= 127) + mask.s_addr = htonl(0xFF000000); + else if (((ntohl(saddr) & 0xFF000000) >> 24) <= 191) + mask.s_addr = htonl(0xFFFF0000); else - return htonl(0xFFFFFF00); + mask.s_addr = htonl(0xFFFFFF00); + + return mask; } /*! - \fn u_int32_t calc_broadcast(u_int32_t addr, int prefix) + \fn struct in_addr calc_broadcast(struct in_addr addr, int prefix) \brief calculate broadcast address given an IP address and a prefix length. @@ -134,13 +134,18 @@ u_int32_t default_netmask(u_int32_t addr) \return the calculated broadcast address for the network, in network byte order. */ -u_int32_t calc_broadcast(u_int32_t addr, int prefix) +struct in_addr calc_broadcast(struct in_addr addr, int prefix) { - return (addr & prefix2mask(prefix)) | ~prefix2mask(prefix); + struct in_addr mask = prefix2mask(prefix); + struct in_addr broadcast; + + memset(&broadcast, 0, sizeof(broadcast)); + broadcast.s_addr = (addr.s_addr & mask.s_addr) | ~mask.s_addr; + return broadcast; } /*! - \fn u_int32_t calc_network(u_int32_t addr, int prefix) + \fn struct in_addr calc_network(struct in_addr addr, int prefix) \brief calculates the network address for a specified address and prefix. \param addr an IP address, in network byte order @@ -148,13 +153,18 @@ u_int32_t calc_broadcast(u_int32_t addr, int prefix) \return the base address of the network that addr is associated with, in network byte order. */ -u_int32_t calc_network(u_int32_t addr, int prefix) +struct in_addr calc_network(struct in_addr addr, int prefix) { - return (addr & prefix2mask(prefix)); + struct in_addr mask = prefix2mask(prefix); + struct in_addr network; + + memset(&network, 0, sizeof(network)); + network.s_addr = addr.s_addr & mask.s_addr; + return network; } /*! - \fn const char *get_hostname(u_int32_t addr) + \fn const char *get_hostname(struct in_addr addr) \brief returns the hostname associated with the specified IP address \param addr an IP address to find a hostname for, in network byte order @@ -163,7 +173,7 @@ u_int32_t calc_network(u_int32_t addr, int prefix) in a static buffer that may disappear at any time, the caller should copy the data if it needs permanent storage. */ -const char *get_hostname(u_int32_t addr) +const char *get_hostname(struct in_addr addr) { struct hostent * hostinfo; int x; @@ -271,7 +281,7 @@ int main(int argc, const char **argv) { fprintf(stderr, "ipcalc: bad netmask: %s\n", netmaskStr); return 1; } - prefix = mask2prefix(netmask.s_addr); + prefix = mask2prefix(netmask); } } @@ -321,10 +331,10 @@ int main(int argc, const char **argv) { if (showNetmask) { if (prefix) { - netmask.s_addr = prefix2mask(prefix); + netmask = prefix2mask(prefix); } else { - netmask.s_addr = default_netmask(ip.s_addr); - prefix = mask2prefix(netmask.s_addr); + netmask = default_netmask(ip); + prefix = mask2prefix(netmask); } printf("NETMASK=%s\n", inet_ntoa(netmask)); @@ -332,22 +342,22 @@ int main(int argc, const char **argv) { if (showPrefix) { if (!prefix) - prefix = mask2prefix(ip.s_addr); + prefix = mask2prefix(ip); printf("PREFIX=%d\n", prefix); } if (showBroadcast) { - broadcast.s_addr = calc_broadcast(ip.s_addr, prefix); + broadcast = calc_broadcast(ip, prefix); printf("BROADCAST=%s\n", inet_ntoa(broadcast)); } if (showNetwork) { - network.s_addr = calc_network(ip.s_addr, prefix); + network = calc_network(ip, prefix); printf("NETWORK=%s\n", inet_ntoa(network)); } if (showHostname) { - if ((hostName = (char *) get_hostname(ip.s_addr)) == NULL) { + if ((hostName = (char *) get_hostname(ip)) == NULL) { if (!beSilent) { sprintf(errBuf, "ipcalc: cannot find hostname for %s", ipStr); herror(errBuf); |