/*
 * Copyright 2001 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

 /*
  * Misc routines that are used by tcpd and by tcpdchk.
  *
  * Author: Wietse Venema, Eindhoven University of Technology, The Netherlands.
  */

#ifndef lint
static char sccsic[] = "@(#) misc.c 1.2 96/02/11 17:01:29";
#endif

#include <sys/types.h>
#include <sys/param.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <netdb.h>

#include "tcpd.h"

extern char *fgets();

#ifndef INADDR_NONE
#define INADDR_NONE     (-1)            /* XXX should be 0xffffffff */
#endif

/* xgets - fgets() with backslash-newline stripping */

char   *xgets(ptr, len, fp)
char   *ptr;
int     len;
FILE   *fp;
{
    int     got;
    char   *start = ptr;

    while (fgets(ptr, len, fp)) {
        got = strlen(ptr);
        if (got >= 1 && ptr[got - 1] == '\n') {
            tcpd_context.line++;
            if (got >= 2 && ptr[got - 2] == '\\') {
                got -= 2;
            } else {
                return (start);
            }
        }
        ptr += got;
        len -= got;
        ptr[0] = 0;
    }
    return (ptr > start ? start : 0);
}

/* split_at - break string at delimiter or return NULL */

char   *split_at(string, delimiter)
char   *string;
int     delimiter;
{
    char   *cp;

    if ((cp = strchr(string, delimiter)) != 0)
        *cp++ = 0;
    return (cp);
}

/* dot_quad_addr - convert dotted quad to internal form */

unsigned long dot_quad_addr(str)
char   *str;
{
    int     in_run = 0;
    int     runs = 0;
    char   *cp = str;

    /* Count the number of runs of non-dot characters. */

    while (*cp) {
        if (*cp == '.') {
            in_run = 0;
        } else if (in_run == 0) {
            in_run = 1;
            runs++;
        }
        cp++;
    }
    return (runs == 4 ? inet_addr(str) : INADDR_NONE);
}

/* numeric_addr - convert textual IP address to binary form */

int numeric_addr(str, addr, af, len)
char *str;
union gen_addr *addr;
int *af;
int *len;
{
    union gen_addr t;

    if (addr == NULL)
        addr = &t;
#ifdef HAVE_IPV6
    if (strchr(str,':')) {
        if (af) *af = AF_INET6;
        if (len) *len = sizeof(struct in6_addr);
        if (inet_pton(AF_INET6, str, (void*) addr) == 1)
            return 0;
        return -1;
    }
#endif
    if (af) *af = AF_INET;
    if (len) *len = sizeof(struct in_addr);
    addr->ga_in.s_addr = dot_quad_addr(str);
    return addr->ga_in.s_addr == INADDR_NONE ? -1 : 0;
}

/* For none RFC 2553 compliant systems */
#ifdef USE_GETHOSTBYNAME2
#define getipnodebyname(h,af,flags,err) gethostbyname2(h,af)
#define freehostent(x)                  x = 0
#endif

/* tcpd_gethostbyname - an IP family neutral gethostbyname */

struct hostent *tcpd_gethostbyname(host, af)
char *host;
int af;
{
#ifdef HAVE_IPV6
    struct hostent *hp;
    static struct hostent *hs;          /* freehostent() on next call */
    int err;

    if (af == AF_INET6) {               /* must be AF_INET6 */
        if (hs)
            freehostent(hs);
        return (hs = getipnodebyname(host, AF_INET6, 0, &err));
    }
    hp = gethostbyname(host);
    if (hp != NULL || af == AF_INET) {  /* found or must be AF_INET */
        return hp;
    } else {                            /* Try INET6 */
        if (hs)
            freehostent(hs);
        return (hs = getipnodebyname(host, AF_INET6, 0, &err));
    }
#else
    return gethostbyname(host);
#endif
}

#ifdef HAVE_IPV6
/*
 * When using IPv6 addresses, we'll be seeing lots of ":"s;
 * we require the addresses to be specified as [address].
 * An IPv6 address can be specified in 3 ways:
 *
 * x:x:x:x:x:x:x:x              (fully specified)
 * x::x:x:x:x                   (zeroes squashed)
 * ::FFFF:1.2.3.4               (IPv4 mapped)
 *
 * These need to be skipped to get at the ":" delimeters.
 *
 * We also allow a '/prefix' specifier.
 */
char *skip_ipv6_addrs(str)
char *str;
{
    char *obr, *cbr, *colon;
    char *p = str;
    char *q;

    while (1) {
        if ((colon = strchr(p, ':')) == NULL)
            return p;
        if ((obr = strchr(p, '[')) == NULL || obr > colon)
            return p;
        if ((cbr = strchr(obr, ']')) == NULL)
            return p;

        for (q = obr + 1; q < cbr; q++) {
            /*
             * Quick and dirty parse, cheaper than inet_pton
             * Could count colons and dots (must be 0 or 3 dots, no
             * colons after dots seens, only one double :, etc, etc)
             */
            if (*q != ':' && *q != '.' && *q != '/' && !isxdigit(*q & 0xff))
                return p;
        }
        p = cbr + 1;
    }
}
#endif /* HAVE_IPV6 */