addressUtility.c

#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <arpa/inet.h>
#include <stdlib.h>

int printSocketAddress(const struct sockaddr *address, char *addrBuffer) {

	void *numericAddress; // Pointer to binary address

	in_port_t port; // Port to print

	// Set pointer to address based on address family
	switch (address->sa_family) {
		case AF_INET:
			numericAddress = &((struct sockaddr_in *) address)->sin_addr;
			port = ntohs(((struct sockaddr_in *) address)->sin_port);
			break;
		case AF_INET6:
			numericAddress = &((struct sockaddr_in6 *) address)->sin6_addr;
			port = ntohs(((struct sockaddr_in6 *) address)->sin6_port);
			break;
		default:
			strcpy(addrBuffer, "[unknown type]");    // Unhandled type
			return 0;
	}
	// Convert binary to printable address
	if (inet_ntop(address->sa_family, numericAddress, addrBuffer, INET6_ADDRSTRLEN) == NULL)
		strcpy(addrBuffer, "[invalid address]"); // Unable to convert
	else {
		if (port != 0)
			sprintf(addrBuffer + strlen(addrBuffer), ":-%u", port);
	}
	return 1;
}

bool sockAddrsEqual(const struct sockaddr *addr1, const struct sockaddr *addr2) {
	if (addr1 == NULL || addr2 == NULL)
		return addr1 == addr2;
	else if (addr1->sa_family != addr2->sa_family)
		return false;
	else if (addr1->sa_family == AF_INET) {
		struct sockaddr_in *ipv4Addr1 = (struct sockaddr_in *) addr1;
		struct sockaddr_in *ipv4Addr2 = (struct sockaddr_in *) addr2;
		return ipv4Addr1->sin_addr.s_addr == ipv4Addr2->sin_addr.s_addr && ipv4Addr1->sin_port == ipv4Addr2->sin_port;
	} else if (addr1->sa_family == AF_INET6) {
		struct sockaddr_in6 *ipv6Addr1 = (struct sockaddr_in6 *) addr1;
		struct sockaddr_in6 *ipv6Addr2 = (struct sockaddr_in6 *) addr2;
		return memcmp(&ipv6Addr1->sin6_addr, &ipv6Addr2->sin6_addr, sizeof(struct in6_addr)) == 0 
			&& ipv6Addr1->sin6_port == ipv6Addr2->sin6_port;
	} else
		return false;
}