static void parse_arguments()

in util/netconsblaster.c [320:399]

• 56 lines of code
• 12 McCabe index (conditional complexity)

static void parse_arguments(int argc, char **argv, struct params *p)
{
	int i;

	/*
	 * Defaults
	 */
	p->srcaddr_order = 16;
	p->thread_order = 0;
	memcpy(&p->src, &in6addr_loopback, sizeof(in6addr_loopback));
	memcpy(&p->dst, &in6addr_loopback, sizeof(in6addr_loopback));
	p->blastcount = 0;

	p->stop_blasting = 0;

	static const char *optstr = "o:s:d:t:n:";
	static const struct option optlong[] = {
		{
			.name = "help",
			.has_arg = no_argument,
			.val = 'h',
		},
		{
			.name = NULL,
		},
	};

	while ((i = getopt_long(argc, argv, optstr, optlong, NULL)) != -1) {
		switch (i) {
		case 'o':
			/*
			 * Controls the number of bits to randomly flip in the
			 * actual IPv6 address of this machine. So the program
			 * will effectively simulate 2^N clients.
			 */
			p->srcaddr_order = atoi(optarg);
			if (p->srcaddr_order > 64 - 8)
				fatal("Source address order too large\n");
			break;
		case 't':
			/*
			 * Split the work among 2^N worker threads.
			 */
			p->thread_order = atoi(optarg);
			if (p->thread_order > 8)
				fatal("Largest supported thread order is 8\n");
			break;
		case 's':
			/*
			 * Source address to permute the low N bits of.
			 */
			if (inet_pton(AF_INET6, optarg, &p->src) != 1)
				fatal("Bad src '%s': %m\n", optarg);
			break;
		case 'd':
			/*
			 * Destination address for all generated packets.
			 */
			if (inet_pton(AF_INET6, optarg, &p->dst) != 1)
				fatal("Bad dst '%s': %m\n", optarg);
			break;
		case 'n':
			/*
			 * Write N packets from each worker thread and exit.
			 */
			p->blastcount = atol(optarg);
			break;
		case 'h':
			puts("Usage: netconsblaster [-o srcaddr_bits] [-t thread_order]\n"
			     "                      [-s srcaddr] [-d dstaddr]\n"
			     "                      [-n pktcount]\n");
			puts("  srcaddr_bits: Randomize low N bits of srcaddr");
			puts("  thread_order: Split work among 2^N threads");
			puts("  pktcount:     Stop after N pkts per thread\n");
			exit(0);
		default:
			fatal("Invalid command line parameters\n");
		}
	}
}