lib/common/getport.c

/*
 * Copyright (C) 1993-2005  by Darren Reed.
 * See the IPFILTER.LICENCE file for details on licencing.
 */

#include "ipf.h"

int getport(fr, name, port)
frentry_t *fr;
char *name;
u_short *port;
{
    struct protoent *p;
    struct servent *s;
    u_short p1;

    if (fr == NULL || fr->fr_type != FR_T_IPF) {
        s = getservbyname(name, NULL);
        if (s != NULL) {
            *port = s->s_port;
            return 0;
        }
        return -1;
    }

    if ((fr->fr_flx & FI_TCPUDP) != 0) {
        /*
         * If a rule is "tcp/udp" then check that both TCP and UDP
         * mappings for this protocol name match ports.
         */
        s = getservbyname(name, "tcp");
        if (s == NULL)
            return -1;
        p1 = s->s_port;
        s = getservbyname(name, "udp");
        if (s == NULL || s->s_port != p1)
            return -1;
        *port = p1;
        return 0;
    }

    p = getprotobynumber(fr->fr_proto);
    s = getservbyname(name, p ? p->p_name : NULL);
    if (s != NULL) {
        *port = s->s_port;
        return 0;
    }
    return -1;
}