summaryrefslogtreecommitdiffstats
path: root/xpa/tcp.c
blob: ddd43663ad036215ba4954ca00146086141ff5a9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
/*
 *	Copyright (c) 1999-2003 Smithsonian Astrophysical Observatory
 */

/*
 *
 * tcp.c -- unix tcp connection routines
 *
 */
#if HAVE_CONFIG_H
#include <conf.h>
#endif

#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_STDLIB_H
#include <stdlib.h>
#endif
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <xport.h>
#include <tcp.h>

/* the ever-present */
#ifndef SZ_LINE
#define SZ_LINE 1024
#endif

/* name of user environment variable specifying this host */
#ifndef MYHOST
#define MYHOST "XPA_HOST"
#endif

/* other modules can set this variable and the default for various routines
   will be "localhost" instead of the DNS-dependent hostname */
int use_localhost=0;

static char myhost[SZ_LINE]; 	/* hostname to registering access points */

/*
 *----------------------------------------------------------------------------
 *
 *
 * 			Private Routines and Data
 *
 *
 *----------------------------------------------------------------------------
 */

static char ipstr[SZ_LINE];

/*
 *----------------------------------------------------------------------------
 *
 *
 *			Public Routines
 *
 *
 *----------------------------------------------------------------------------
 */

/*
 *--------------------------------------------------------------
 *
 * Routines:	gethost
 *
 * Purpose:	Find the current hostname
 *
 * Results:	1 on success, 0 for failure
 *
 *--------------------------------------------------------------
 */
#ifdef ANSI_FUNC
int 
gethost (
    char *xhost,		/* (out) corresponding hostname */
    int len			/* (in) length of host buffer */
)
#else
int gethost(xhost, len)
    char *xhost;		/* (out) corresponding hostname */
    int len;			/* (in) length of host buffer */
#endif
{
    char *s=NULL;
    struct hostent *hent;
    static int init=0;

    if( use_localhost == 0 ){
      if( init == 0 ){
	if( (s=(char *)getenv(MYHOST)) != NULL ){
	  strncpy(myhost, s, SZ_LINE-1);
	} else {
	  gethostname(myhost, SZ_LINE-1);
	}
	init++;
      }
      strncpy(xhost, myhost, len-1);
      if( (hent = gethostbyname(xhost)) == NULL ){
	return(-1);
      }
      strncpy(xhost, hent->h_name, len-1);
    }
    else{
      strncpy(xhost, "localhost", len-1);
    }
    xhost[len-1] = '\0';
    return(0);
}

/*
 *----------------------------------------------------------------------------
 *
 * Routine:	gethostip
 *
 * Purpose:	Find the IP address corresponding to a hostname
 *
 * Results: 	ip (host byte order) on success, 0 if host is unknown
 *
 *---------------------------------------------------------------------------
 */
#ifdef ANSI_FUNC
unsigned int 
gethostip (
    char *xhost		/* (in) Hostname (human readable) */
)
#else
unsigned int gethostip(xhost)
    char *xhost;		/* (in) Hostname (human readable) */
#endif
{
    struct hostent *hostent;
    unsigned int ip;
    char temp[SZ_LINE];
    int saveip=0;
    static unsigned int myip=0;
    
    
    /* null input means current host */
    if( (xhost == NULL) || (*xhost == '\0') || !strcmp(xhost, "$host") ){
      if( myip != 0 )
	return(myip);
      saveip = 1;
      gethost(temp, SZ_LINE);
    }
    else if( !strcmp(xhost, "$localhost")  ){
      strcpy(temp, "localhost");
    } else {
      strncpy(temp, xhost, SZ_LINE-1);
      temp[SZ_LINE-1] = '\0';
    }

    /* special check */
    if( !strcmp(temp, "localhost") || !strcmp(temp, "localhost.localdomain") ){
      ip = htonl(0x7F000001);
      goto done;
    }

    /*
     * Try looking by address (i.e., host is something like "128.84.253.1").
     * Do this first because it's much faster (no trip to the DNS)
     */
    if( (int)(ip = inet_addr(temp)) != -1 ){
      goto done;
    }

    /*
     * Try looking it up by name. If successful, the IP address is in
     * hostent->h_addr_list[0]
     */
    if( (hostent = gethostbyname(temp)) != NULL ){
      memcpy(&ip, hostent->h_addr_list[0], (size_t)hostent->h_length);
      goto done;
    }

    /* could not convert */
    ip = 0;
    saveip = 0;

done:
    ip = ntohl(ip);
    if( saveip ) myip = ip;
    return(ip);
}

/*
 *----------------------------------------------------------------------------
 *
 * Routine:	getiphost
 *
 * Purpose:	Find the IP address in dot format corresponding to an ip
 *
 * Results: 	ip string (in static buffer) or NULL
 *
 *---------------------------------------------------------------------------
 */
#ifdef ANSI_FUNC
char *
getiphost (unsigned int ip)
#else
char *getiphost(ip)
     unsigned int ip;
#endif
{
  char *s;
  struct sockaddr_in sockbuf;

  if( ip == 0x7F000001 ){
    strcpy(ipstr, "localhost");
    return(ipstr);
  }

  sockbuf.sin_addr.s_addr = htonl(ip);
  s = (char *)inet_ntoa(sockbuf.sin_addr);
  if( s != NULL ){
    strcpy(ipstr, s);
    return(ipstr);
  }
  else
    return(NULL);
}