Arthur de Jong

Open Source / Free Software developer

summaryrefslogtreecommitdiffstats
path: root/nss/ethers.c
blob: 291c797139d6459ff406c0e133b90754ac773e02 (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
/*
   ethers.c - NSS lookup functions for ethers database

   Copyright (C) 2006 West Consulting
   Copyright (C) 2006-2015 Arthur de Jong
   Copyright (C) 2010 Symas Corporation

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
   02110-1301 USA
*/

#include "config.h"

#include <string.h>
#include <errno.h>

#include "prototypes.h"
#include "common.h"
#include "compat/attrs.h"

/* read an ethernet entry from the stream */
static nss_status_t read_etherent(TFILE *fp, struct etherent *result,
                                  char *buffer, size_t buflen, int *errnop)
{
  int32_t tmpint32;
  size_t bufptr = 0;
  memset(result, 0, sizeof(struct etherent));
  READ_BUF_STRING(fp, result->e_name);
  READ(fp, &(result->e_addr), sizeof(uint8_t[6]));
  return NSS_STATUS_SUCCESS;
}

#ifdef NSS_FLAVOUR_GLIBC

/* map a hostname to the corresponding ethernet address */
nss_status_t NSS_NAME(gethostton_r)(const char *name,
                                    struct etherent *result, char *buffer,
                                    size_t buflen, int *errnop)
{
  NSS_GETONE(NSLCD_ACTION_ETHER_BYNAME,
             WRITE_STRING(fp, name),
             read_etherent(fp, result, buffer, buflen, errnop));
}

/* map an ethernet address to the corresponding hostname */
nss_status_t NSS_NAME(getntohost_r)(const struct ether_addr *addr,
                                    struct etherent *result, char *buffer,
                                    size_t buflen, int *errnop)
{
  NSS_GETONE(NSLCD_ACTION_ETHER_BYETHER,
             WRITE(fp, addr, sizeof(uint8_t[6])),
             read_etherent(fp, result, buffer, buflen, errnop));
}

/* thread-local file pointer to an ongoing request */
static TLS TFILE *etherentfp;

/* open a connection to read all ether entries */
nss_status_t NSS_NAME(setetherent)(int UNUSED(stayopen))
{
  NSS_SETENT(etherentfp);
}

/* read a single ethernet entry from the stream */
nss_status_t NSS_NAME(getetherent_r)(struct etherent *result,
                                     char *buffer, size_t buflen, int *errnop)
{
  NSS_GETENT(etherentfp, NSLCD_ACTION_ETHER_ALL,
             read_etherent(etherentfp, result, buffer, buflen, errnop));
}

/* close the stream opened with setetherent() above */
nss_status_t NSS_NAME(endetherent)(void)
{
  NSS_ENDENT(etherentfp);
}

#endif /* NSS_FLAVOUR_GLIBC */

#ifdef NSS_FLAVOUR_SOLARIS

/* we disable NSS_BUFCHECK because these functions do not use the buffer */
#undef NSS_BUFCHECK
#define NSS_BUFCHECK ;

/* provide a fallback definition */
#ifndef NSS_BUFLEN_ETHERS
#define NSS_BUFLEN_ETHERS HOST_NAME_MAX
#endif /* NSS_BUFLEN_ETHERS */

#ifdef HAVE_STRUCT_NSS_XBYY_ARGS_RETURNLEN
static char *etherent2str(struct etherent *result, char *buffer,
                          size_t buflen)
{
  int res;
  res = snprintf(buffer, buflen, "%s %s", ether_ntoa(&result->e_addr),
                 result->e_name);
  if ((res < 0) || (res >= (int)buflen))
    return NULL;
  return buffer;
}
#endif /* HAVE_STRUCT_NSS_XBYY_ARGS_RETURNLEN */

static nss_status_t read_result(TFILE *fp, nss_XbyY_args_t *args, int wantname)
{
  struct etherent result;
  char buffer[NSS_BUFLEN_ETHERS];
  nss_status_t retv;
  /* read the result entry from the stream */
  retv = read_etherent(fp, &result, buffer, sizeof(buffer), &args->erange);
  if (retv != NSS_STATUS_SUCCESS)
    return retv;
#ifdef HAVE_STRUCT_NSS_XBYY_ARGS_RETURNLEN
  /* try to return in string format if requested */
  if ((args->buf.buffer != NULL) && (args->buf.buflen > 0))
  {
    if (etherent2str(&result, args->buf.buffer, args->buf.buflen) == NULL)
    {
      args->erange = 1;
      return NSS_NOTFOUND;
    }
    args->returnval = args->buf.buffer;
    args->returnlen = strlen(args->returnval);
    return NSS_SUCCESS;
  }
#endif /* HAVE_STRUCT_NSS_XBYY_ARGS_RETURNLEN */
  /* return the result entry */
  if (wantname)
  {
    /* we expect the buffer to have enough room for the name (buflen == 0) */
    strcpy(args->buf.buffer, result.e_name);
    args->returnval = args->buf.buffer;
  }
  else /* address */
  {
    memcpy(args->buf.result, &result.e_addr, sizeof(result.e_addr));
    args->returnval = args->buf.result;
  }
  return NSS_SUCCESS;
}

/* map a hostname to the corresponding ethernet address */
static nss_status_t ethers_gethostton(nss_backend_t UNUSED(*be), void *args)
{
  NSS_GETONE(NSLCD_ACTION_ETHER_BYNAME,
             WRITE_STRING(fp, NSS_ARGS(args)->key.name),
             read_result(fp, args, 0));
}

/* map an ethernet address to the corresponding hostname */
static nss_status_t ethers_getntohost(nss_backend_t UNUSED(*be), void *args)
{
  struct ether_addr *addr = (struct ether_addr *)(NSS_ARGS(args)->key.ether);
  NSS_GETONE(NSLCD_ACTION_ETHER_BYETHER,
             WRITE(fp, addr, sizeof(uint8_t[6])),
             read_result(fp, args, 1));
}

static nss_backend_op_t ethers_ops[] = {
  nss_ldap_destructor,
  ethers_gethostton,
  ethers_getntohost
};

nss_backend_t *NSS_NAME(ethers_constr)(const char UNUSED(*db_name),
                                       const char UNUSED(*src_name),
                                       const char UNUSED(*cfg_args))
{
  return nss_ldap_constructor(ethers_ops, sizeof(ethers_ops));
}

#endif /* NSS_FLAVOUR_SOLARIS */