49 lines
1.3 KiB
C
49 lines
1.3 KiB
C
/*
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* netof - return the net address part of an ip address in a sockaddr_storage structure
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* (zero out host part)
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*/
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#include <stdio.h>
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#include "ntp_fp.h"
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#include "ntp_stdlib.h"
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#include "ntp.h"
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#define NUM_NETOF_BUFS 10
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static struct sockaddr_storage ssbuf[NUM_NETOF_BUFS];
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static int next_ssbuf = 0;
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struct sockaddr_storage*
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netof(
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struct sockaddr_storage* hostaddr
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)
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{
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register u_int32 netnum;
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struct sockaddr_storage *netaddr;
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netaddr = &ssbuf[next_ssbuf++];
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if (next_ssbuf == NUM_NETOF_BUFS)
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next_ssbuf = 0;
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memcpy(netaddr, hostaddr, sizeof(struct sockaddr_storage));
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if(netaddr->ss_family == AF_INET) {
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netnum = ((struct sockaddr_in*)netaddr)->sin_addr.s_addr;
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/*
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* We live in a modern CIDR world where the basement nets, which
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* used to be class A, are now probably associated with each
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* host address. So, for class-A nets, all bits are significant.
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*/
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if(IN_CLASSC(netnum))
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netnum &= IN_CLASSC_NET;
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else if (IN_CLASSB(netnum))
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netnum &= IN_CLASSB_NET;
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((struct sockaddr_in*)netaddr)->sin_addr.s_addr = netnum;
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}
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else if(netaddr->ss_family == AF_INET6) {
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/* Here we put 0 at the local link address so we get net address */
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memset(&((struct sockaddr_in6*)netaddr)->sin6_addr.s6_addr[8], 0, 8*sizeof(u_char));
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}
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return netaddr;
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}
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