decodenetnum.c revision 290000 
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	REQUIRE(num != NULL);
39
40	if (strlen(num) >= sizeof(name)) {
41		return 0;
42	}
43
44	port_str = NULL;
45	if ('[' != num[0]) {
46		/*
47		 * to distinguish IPv6 embedded colons from a port
48		 * specification on an IPv4 address, assume all
49		 * legal IPv6 addresses have at least two colons.
50		 */
51		pp = strchr(num, ':');
52		if (NULL == pp)
53			cp = num;	/* no colons */
54		else if (NULL != strchr(pp + 1, ':'))
55			cp = num;	/* two or more colons */
56		else {			/* one colon */
57			strlcpy(name, num, sizeof(name));
58			cp = name;
59			pp = strchr(cp, ':');
60			*pp = '\0';
61			port_str = pp + 1;
62		}
63	} else {
64		cp = num + 1;
65		np = name;
66		while (*cp && ']' != *cp)
67			*np++ = *cp++;
68		*np = 0;
69		if (']' == cp[0] && ':' == cp[1] && '\0' != cp[2])
70			port_str = &cp[2];
71		cp = name;
72	}
73	ZERO(hints);
74	hints.ai_flags = Z_AI_NUMERICHOST;
75	err = getaddrinfo(cp, "ntp", &hints, &ai);
76	if (err != 0)
77		return 0;
78	INSIST(ai->ai_addrlen <= sizeof(*netnum));
79	ZERO(*netnum);
80	memcpy(netnum, ai->ai_addr, ai->ai_addrlen);
81	freeaddrinfo(ai);
82	if (NULL == port_str || 1 != sscanf(port_str, "%hu", &port))
83		port = NTP_PORT;
84	SET_PORT(netnum, port);
85	return 1;
86}
87