xref: /freebsd/sbin/ipf/libipf/getport.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
1 /*	$FreeBSD$	*/
2 
3 /*
4  * Copyright (C) 2012 by Darren Reed.
5  *
6  * See the IPFILTER.LICENCE file for details on licencing.
7  *
8  * $Id$
9  */
10 
11 #include "ipf.h"
12 #include <ctype.h>
13 
14 int
15 getport(frentry_t *fr, char *name, u_short *port, char *proto)
16 {
17 	struct protoent *p;
18 	struct servent *s;
19 	u_short p1;
20 
21 	if (fr == NULL || fr->fr_type != FR_T_IPF) {
22 		s = getservbyname(name, proto);
23 		if (s != NULL) {
24 			*port = s->s_port;
25 			return (0);
26 		}
27 
28 		if (ISDIGIT(*name)) {
29 			int portval = atoi(name);
30 			if (portval < 0 || portval > 65535)
31 				return (-1);
32 			*port = htons((u_short)portval);
33 			return (0);
34 		}
35 		return (-1);
36 	}
37 
38 	/*
39 	 * Some people will use port names in rules without specifying
40 	 * either TCP or UDP because it is implied by the group head.
41 	 * If we don't know the protocol, then the best we can do here is
42 	 * to take either only the TCP or UDP mapping (if one or the other
43 	 * is missing) or make sure both of them agree.
44 	 */
45 	if (fr->fr_proto == 0) {
46 		s = getservbyname(name, "tcp");
47 		if (s != NULL)
48 			p1 = s->s_port;
49 		else
50 			p1 = 0;
51 		s = getservbyname(name, "udp");
52 		if (s != NULL) {
53 			if (p1 != s->s_port)
54 				return (-1);
55 		}
56 		if ((p1 == 0) && (s == NULL))
57 			return (-1);
58 		if (p1)
59 			*port = p1;
60 		else
61 			*port = s->s_port;
62 		return (0);
63 	}
64 
65 	if ((fr->fr_flx & FI_TCPUDP) != 0) {
66 		/*
67 		 * If a rule is "tcp/udp" then check that both TCP and UDP
68 		 * mappings for this protocol name match ports.
69 		 */
70 		s = getservbyname(name, "tcp");
71 		if (s == NULL)
72 			return (-1);
73 		p1 = s->s_port;
74 		s = getservbyname(name, "udp");
75 		if (s == NULL || s->s_port != p1)
76 			return (-1);
77 		*port = p1;
78 		return (0);
79 	}
80 
81 	p = getprotobynumber(fr->fr_proto);
82 	s = getservbyname(name, p ? p->p_name : NULL);
83 	if (s != NULL) {
84 		*port = s->s_port;
85 		return (0);
86 	}
87 	return (-1);
88 }
89