decodenetnum.c revision 280849 
1/*
2 * decodenetnum - return a net number (this is crude, but careful)
3 */
4#include <config.h>
5#include <sys/types.h>
6#include <ctype.h>
7#ifdef HAVE_SYS_SOCKET_H
8#include <sys/socket.h>
9#endif
10#ifdef HAVE_NETINET_IN_H
11#include <netinet/in.h>
12#endif
13
14#include "ntp.h"
15#include "ntp_stdlib.h"
16#include "ntp_assert.h"
17
18/*
19 * decodenetnum		convert text IP address and port to sockaddr_u
20 *
21 * Returns 0 for failure, 1 for success.
22 */
23int
24decodenetnum(
25	const char *num,
26	sockaddr_u *netnum
27	)
28{
29	struct addrinfo hints, *ai = NULL;
30	int err;
31	u_short port;
32	const char *cp;
33	const char *port_str;
34	char *pp;
35	char *np;
36	char name[80];
37
38	NTP_REQUIRE(num != NULL);
39	NTP_REQUIRE(strlen(num) < sizeof(name));
40
41	port_str = NULL;
42	if ('[' != num[0]) {
43		/*
44		 * to distinguish IPv6 embedded colons from a port
45		 * specification on an IPv4 address, assume all
46		 * legal IPv6 addresses have at least two colons.
47		 */
48		pp = strchr(num, ':');
49		if (NULL == pp)
50			cp = num;	/* no colons */
51		else if (NULL != strchr(pp + 1, ':'))
52			cp = num;	/* two or more colons */
53		else {			/* one colon */
54			strlcpy(name, num, sizeof(name));
55			cp = name;
56			pp = strchr(cp, ':');
57			*pp = '\0';
58			port_str = pp + 1;
59		}
60	} else {
61		cp = num + 1;
62		np = name;
63		while (*cp && ']' != *cp)
64			*np++ = *cp++;
65		*np = 0;
66		if (']' == cp[0] && ':' == cp[1] && '\0' != cp[2])
67			port_str = &cp[2];
68		cp = name;
69	}
70	ZERO(hints);
71	hints.ai_flags = Z_AI_NUMERICHOST;
72	err = getaddrinfo(cp, "ntp", &hints, &ai);
73	if (err != 0)
74		return 0;
75	NTP_INSIST(ai->ai_addrlen <= sizeof(*netnum));
76	ZERO(*netnum);
77	memcpy(netnum, ai->ai_addr, ai->ai_addrlen);
78	freeaddrinfo(ai);
79	if (NULL == port_str || 1 != sscanf(port_str, "%hu", &port))
80		port = NTP_PORT;
81	SET_PORT(netnum, port);
82	return 1;
83}
84