xref: /freebsd/contrib/ntp/libntp/decodenetnum.c (revision 2b15cb3d0922bd70ea592f0da9b4a5b167f4d53f)
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  */
23 int
24 decodenetnum(
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