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-rw-r--r--src/ipcalc.c98
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);
generated by cgit v1.2.1 (git 2.21.0) at 2024-11-15 19:57:31 +0000