Arthur de Jong

Open Source / Free Software developer

summaryrefslogtreecommitdiffstats
path: root/nslcd/common.c
blob: ec20693a57dbd5df7c81c1020e0171600be7d805 (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
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
/*
   common.c - common server code routines
   This file is part of the nss-pam-ldapd library.

   Copyright (C) 2006 West Consulting
   Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Arthur de Jong

   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 <stdio.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <strings.h>
#include <limits.h>
#include <netdb.h>
#include <string.h>
#include <regex.h>
#include <stdlib.h>

#include "nslcd.h"
#include "common.h"
#include "log.h"
#include "attmap.h"
#include "cfg.h"

/* simple wrapper around snptintf() to return non-0 in case
   of any failure (but always keep string 0-terminated) */
int mysnprintf(char *buffer,size_t buflen,const char *format, ...)
{
  int res;
  va_list ap;
  /* do snprintf */
  va_start(ap,format);
  res=vsnprintf(buffer,buflen,format,ap);
  va_end(ap);
  /* NULL-terminate the string just to be on the safe side */
  buffer[buflen-1]='\0';
  /* check if the string was completely written */
  return ((res<0)||(((size_t)res)>=buflen));
}

/* return the fully qualified domain name of the current host */
const char *getfqdn(void)
{
  static char *fqdn=NULL;
  char hostname[HOST_NAME_MAX+1];
  int hostnamelen;
  int i;
  struct hostent *host=NULL;
  /* if we already have a fqdn return that */
  if (fqdn!=NULL)
    return fqdn;
  /* get system hostname */
  if (gethostname(hostname,sizeof(hostname))<0)
  {
    log_log(LOG_ERR,"gethostname() failed: %s",strerror(errno));
    return NULL;
  }
  hostnamelen=strlen(hostname);
  /* lookup hostent */
  host=gethostbyname(hostname);
  if (host==NULL)
  {
    log_log(LOG_ERR,"gethostbyname(%s): %s",hostname,hstrerror(h_errno));
    /* fall back to hostname */
    fqdn=strdup(hostname);
    return fqdn;
  }
  /* check h_name for fqdn starting with our hostname */
  if ((strncasecmp(hostname,host->h_name,hostnamelen)==0)&&
      (host->h_name[hostnamelen]=='.')&&
      (host->h_name[hostnamelen+1]!='\0'))
  {
    fqdn=strdup(host->h_name);
    return fqdn;
  }
  /* also check h_aliases */
  for (i=0;host->h_aliases[i]!=NULL;i++)
  {
    if ((strncasecmp(hostname,host->h_aliases[i],hostnamelen)==0)&&
        (host->h_aliases[i][hostnamelen]=='.')&&
        (host->h_aliases[i][hostnamelen+1]!='\0'))
    {
      fqdn=strdup(host->h_aliases[i]);
      return fqdn;
    }
  }
  /* fall back to h_name if it has a dot in it */
  if (strchr(host->h_name,'.')!=NULL)
  {
    fqdn=strdup(host->h_name);
    return fqdn;
  }
  /* also check h_aliases */
  for (i=0;host->h_aliases[i]!=NULL;i++)
  {
    if (strchr(host->h_aliases[i],'.')!=NULL)
    {
      fqdn=strdup(host->h_aliases[i]);
      return fqdn;
    }
  }
  /* nothing found, fall back to hostname */
  fqdn=strdup(hostname);
  return fqdn;
}

const char *get_userpassword(MYLDAP_ENTRY *entry,const char *attr,char *buffer,size_t buflen)
{
  const char *tmpvalue;
  /* get the value */
  tmpvalue=attmap_get_value(entry,attr,buffer,buflen);
  if (tmpvalue==NULL)
    return NULL;
  /* go over the entries and return the remainder of the value if it
     starts with {crypt} or crypt$ */
  if (strncasecmp(tmpvalue,"{crypt}",7)==0)
    return tmpvalue+7;
  if (strncasecmp(tmpvalue,"crypt$",6)==0)
    return tmpvalue+6;
  /* just return the first value completely */
  return tmpvalue;
  /* TODO: support more password formats e.g. SMD5
    (which is $1$ but in a different format)
    (any code for this is more than welcome) */
}

/* Checks if the specified name seems to be a valid user or group name. */
int isvalidname(const char *name)
{
  return regexec(&nslcd_cfg->validnames,name,0,NULL,0)==0;
}

/* this writes a single address to the stream */
int write_address(TFILE *fp,MYLDAP_ENTRY *entry,const char *attr,
                  const char *addr)
{
  int32_t tmpint32;
  struct in_addr ipv4addr;
  struct in6_addr ipv6addr;
  /* try to parse the address as IPv4 first, fall back to IPv6 */
  if (inet_pton(AF_INET,addr,&ipv4addr)>0)
  {
    /* write address type */
    WRITE_INT32(fp,AF_INET);
    /* write the address length */
    WRITE_INT32(fp,sizeof(struct in_addr));
    /* write the address itself (in network byte order) */
    WRITE_TYPE(fp,ipv4addr,struct in_addr);
  }
  else if (inet_pton(AF_INET6,addr,&ipv6addr)>0)
  {
    /* write address type */
    WRITE_INT32(fp,AF_INET6);
    /* write the address length */
    WRITE_INT32(fp,sizeof(struct in6_addr));
    /* write the address itself (in network byte order) */
    WRITE_TYPE(fp,ipv6addr,struct in6_addr);
  }
  else
  {
    /* failure, log but write simple invalid address
       (otherwise the address list is messed up) */
    /* TODO: have error message in correct format */
    log_log(LOG_WARNING,"%s: %s: \"%s\" unparseble",
                        myldap_get_dn(entry),attmap_ether_cn,addr);
    /* write an illegal address type */
    WRITE_INT32(fp,-1);
    /* write an emtpy address */
    WRITE_INT32(fp,0);
  }
  /* we're done */
  return 0;
}

int read_address(TFILE *fp,char *addr,int *addrlen,int *af)
{
  int32_t tmpint32;
  int len;
  /* read address family */
  READ_INT32(fp,*af);
  if ((*af!=AF_INET)&&(*af!=AF_INET6))
  {
    log_log(LOG_WARNING,"incorrect address family specified: %d",*af);
    return -1;
  }
  /* read address length */
  READ_INT32(fp,len);
  if ((len>*addrlen)||(len<=0))
  {
    log_log(LOG_WARNING,"address length incorrect: %d",len);
    return -1;
  }
  *addrlen=len;
  /* read address */
  READ(fp,addr,len);
  /* we're done */
  return 0;
}

/* convert the provided string representation of a sid
   (e.g. S-1-5-21-1936905831-823966427-12391542-23578)
   to a format that can be used to search the objectSid property with */
char *sid2search(const char *sid)
{
  const char *tmpsid=sid;
  char *res,*tmp;
  int i=0;
  long int l;
  /* check the beginning of the string */
  if (strncasecmp(sid,"S-",2)!=0)
  {
    log_log(LOG_ERR,"error in SID %s",sid);
    exit(EXIT_FAILURE);
  }
  /* count the number of dashes in the sid */
  while (tmpsid!=NULL)
  {
    i++;
    tmpsid=strchr(tmpsid+1,'-');
  }
  i-=2; /* number of security ids plus one because we add the uid later */
  /* allocate memory */
  res=malloc(3+3+6*3+i*4*3+1);
  if (res==NULL)
  {
    log_log(LOG_CRIT,"malloc() failed to allocate memory");
    exit(1);
  }
  /* build the first part */
  l=strtol(sid+2,&tmp,10);
  sprintf(res,"\\%02x\\%02x",(int)l&0xff,(int)i);
  /* build authority part (we only handle 32 of the 48 bits) */
  l=strtol(tmp+1,&tmp,10);
  sprintf(res+strlen(res),"\\00\\00\\%02x\\%02x\\%02x\\%02x",
          (int)((l>>24)&0xff),(int)((l>>16)&0xff),(int)((l>>8)&0xff),(int)(l&0xff));
  /* go over the rest of the bits */
  while (*tmp!='\0')
  {
    l=strtol(tmp+1,&tmp,10);
    sprintf(res+strlen(res),"\\%02x\\%02x\\%02x\\%02x",
            (int)(l&0xff),(int)((l>>8)&0xff),(int)((l>>16)&0xff),(int)((l>>24)&0xff));
  }
  return res;
}

/* return the last security identifier of the binary sid */
long int binsid2id(const char *binsid)
{
  int i;
  /* find the position of the last security id */
  i=2+6+((((int)binsid[1])&0xff)-1)*4;
  return (((long int)binsid[i])&0xff)|((((long int)binsid[i+1])&0xff)<<8)|
         ((((long int)binsid[i+2])&0xff)<<16)|((((long int)binsid[i+3])&0xff)<<24);
}

#ifdef WANT_STRTOUI
/* provide a strtoui() implementation, similar to strtoul() but returning
   an range-checked unsigned int instead */
unsigned int strtoui(const char *nptr,char **endptr,int base)
{
  unsigned long val;
  val=strtoul(nptr,endptr,base);
  if (val>UINT_MAX)
  {
    errno=ERANGE;
    return UINT_MAX;
  }
  /* If errno was set by strtoul, we'll pass it back as-is */
  return (unsigned int)val;
}
#endif /* WANT_STRTOUI */