1 /* Copyright (C) 1997-2022 Free Software Foundation, Inc.
2    This file is part of the GNU C Library.
3 
4    The GNU C Library is free software; you can redistribute it and/or
5    modify it under the terms of the GNU Lesser General Public
6    License as published by the Free Software Foundation; either
7    version 2.1 of the License, or (at your option) any later version.
8 
9    The GNU C Library is distributed in the hope that it will be useful,
10    but WITHOUT ANY WARRANTY; without even the implied warranty of
11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12    Lesser General Public License for more details.
13 
14    You should have received a copy of the GNU Lesser General Public
15    License along with the GNU C Library; if not, see
16    <https://www.gnu.org/licenses/>.  */
17 
18 #include <errno.h>
19 #include <hesiod.h>
20 #include <pwd.h>
21 #include <nss.h>
22 #include <stdio.h>
23 #include <stdlib.h>
24 #include <string.h>
25 
NSS_DECLARE_MODULE_FUNCTIONS(hesiod)26 NSS_DECLARE_MODULE_FUNCTIONS (hesiod)
27 
28 /* Get the declaration of the parser function.  */
29 #define ENTNAME pwent
30 #define STRUCTURE passwd
31 #define EXTERN_PARSER
32 #include <nss/nss_files/files-parse.c>
33 
34 enum nss_status
35 _nss_hesiod_setpwent (int stayopen)
36 {
37   return NSS_STATUS_SUCCESS;
38 }
39 
40 enum nss_status
_nss_hesiod_endpwent(void)41 _nss_hesiod_endpwent (void)
42 {
43   return NSS_STATUS_SUCCESS;
44 }
45 
46 static enum nss_status
lookup(const char * name,const char * type,struct passwd * pwd,char * buffer,size_t buflen,int * errnop)47 lookup (const char *name, const char *type, struct passwd *pwd,
48 	char *buffer, size_t buflen, int *errnop)
49 {
50   struct parser_data *data = (void *) buffer;
51   size_t linebuflen;
52   void *context;
53   char **list;
54   int parse_res;
55   size_t len;
56   int olderr = errno;
57 
58   if (hesiod_init (&context) < 0)
59     return NSS_STATUS_UNAVAIL;
60 
61   list = hesiod_resolve (context, name, type);
62   if (list == NULL)
63     {
64       int err = errno;
65       hesiod_end (context);
66       __set_errno (olderr);
67       return err == ENOENT ? NSS_STATUS_NOTFOUND : NSS_STATUS_UNAVAIL;
68     }
69 
70   linebuflen = buffer + buflen - data->linebuffer;
71   len = strlen (*list) + 1;
72   if (linebuflen < len)
73     {
74       hesiod_free_list (context, list);
75       hesiod_end (context);
76       *errnop = ERANGE;
77       return NSS_STATUS_TRYAGAIN;
78     }
79 
80   memcpy (data->linebuffer, *list, len);
81   hesiod_free_list (context, list);
82   hesiod_end (context);
83 
84   parse_res = _nss_files_parse_pwent (buffer, pwd, data, buflen, errnop);
85   if (parse_res < 1)
86     {
87       __set_errno (olderr);
88       return parse_res == -1 ? NSS_STATUS_TRYAGAIN : NSS_STATUS_NOTFOUND;
89     }
90 
91   return NSS_STATUS_SUCCESS;
92 }
93 
94 enum nss_status
_nss_hesiod_getpwnam_r(const char * name,struct passwd * pwd,char * buffer,size_t buflen,int * errnop)95 _nss_hesiod_getpwnam_r (const char *name, struct passwd *pwd,
96 			char *buffer, size_t buflen, int *errnop)
97 {
98   return lookup (name, "passwd", pwd, buffer, buflen, errnop);
99 }
100 
101 enum nss_status
_nss_hesiod_getpwuid_r(uid_t uid,struct passwd * pwd,char * buffer,size_t buflen,int * errnop)102 _nss_hesiod_getpwuid_r (uid_t uid, struct passwd *pwd,
103 			char *buffer, size_t buflen, int *errnop)
104 {
105   char uidstr[21];	/* We will probably never have a gid_t with more
106 			   than 64 bits.  */
107 
108   snprintf (uidstr, sizeof uidstr, "%d", uid);
109 
110   return lookup (uidstr, "uid", pwd, buffer, buflen, errnop);
111 }
112