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
|
/*
* utils/mountd/auth.c
*
* Authentication procedures for mountd.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#include "config.h"
#include <sys/stat.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <errno.h>
#include "misc.h"
#include "nfslib.h"
#include "exportfs.h"
#include "mountd.h"
#include "xmalloc.h"
enum auth_error
{
bad_path,
unknown_host,
no_entry,
not_exported,
illegal_port,
faked_hostent,
no_forward_dns,
success
};
static void auth_fixpath(char *path);
static nfs_export* auth_authenticate_internal
(char *what, struct sockaddr_in *caller, char *path,
struct hostent **hpp, enum auth_error *error);
static char *export_file = NULL;
void
auth_init(char *exports)
{
export_file = exports;
auth_reload();
xtab_mount_write();
}
int
auth_reload()
{
struct stat stb;
static time_t last_modified = 0;
if (stat(_PATH_ETAB, &stb) < 0)
xlog(L_FATAL, "couldn't stat %s", _PATH_ETAB);
if (stb.st_mtime == last_modified)
return 0;
last_modified = stb.st_mtime;
export_freeall();
// export_read(export_file);
xtab_export_read();
return 1;
}
static nfs_export *
auth_authenticate_internal(char *what, struct sockaddr_in *caller,
char *path, struct hostent **hpp,
enum auth_error *error)
{
struct in_addr addr = caller->sin_addr;
nfs_export *exp;
if (path[0] != '/') {
*error = bad_path;
return NULL;
}
auth_fixpath(path);
/* First try it w/o doing a hostname lookup... */
*hpp = get_hostent((const char *)&addr, sizeof(addr), AF_INET);
exp = export_find(*hpp, path);
if (!exp) {
/* Ok, that didn't fly. Try it with a reverse lookup. */
free (*hpp);
*hpp = gethostbyaddr((const char *)&addr, sizeof(addr),
AF_INET);
if (!(*hpp)) {
*error = no_entry;
*hpp = get_hostent((const char *)&addr, sizeof(addr), AF_INET);
return NULL;
} else {
/* must make sure the hostent is authorative. */
char **sp;
struct hostent *forward = NULL;
char *tmpname;
*hpp = hostent_dup (*hpp);
tmpname = xstrdup((*hpp)->h_name);
if (tmpname) {
forward = gethostbyname(tmpname);
free(tmpname);
}
if (forward) {
/* now make sure the "addr" is in the list */
for (sp = forward->h_addr_list ; *sp ; sp++) {
if (memcmp(*sp, &addr, forward->h_length)==0)
break;
}
if (!*sp) {
/* it was a FAKE */
*error = faked_hostent;
return NULL;
}
free (*hpp);
*hpp = hostent_dup (forward);
}
else {
/* never heard of it. misconfigured DNS? */
*error = no_forward_dns;
return NULL;
}
}
if (!(exp = export_find(*hpp, path))) {
*error = no_entry;
return NULL;
}
}
if (!exp->m_mayexport) {
*error = not_exported;
return NULL;
}
if (!(exp->m_export.e_flags & NFSEXP_INSECURE_PORT) &&
(ntohs(caller->sin_port) < IPPORT_RESERVED/2 ||
ntohs(caller->sin_port) >= IPPORT_RESERVED)) {
*error = illegal_port;
return NULL;
}
*error = success;
return exp;
}
nfs_export *
auth_authenticate(char *what, struct sockaddr_in *caller, char *path)
{
nfs_export *exp = NULL;
char epath[MAXPATHLEN+1];
char *p = NULL;
struct hostent *hp = NULL;
struct in_addr addr = caller->sin_addr;
enum auth_error error;
if (path [0] != '/') {
xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
what, inet_ntoa(addr), path);
return exp;
}
strncpy(epath, path, sizeof (epath) - 1);
epath[sizeof (epath) - 1] = '\0';
/* Try the longest matching exported pathname. */
while (1) {
if (hp) {
free (hp);
hp = NULL;
}
exp = auth_authenticate_internal(what, caller, epath,
&hp, &error);
if (exp || (error != not_exported && error != no_entry))
break;
/* We have to treat the root, "/", specially. */
if (p == &epath[1]) break;
p = strrchr(epath, '/');
if (p == epath) p++;
*p = '\0';
}
switch (error) {
case bad_path:
xlog(L_WARNING, "bad path in %s request from %s: \"%s\"",
what, inet_ntoa(addr), path);
break;
case unknown_host:
xlog(L_WARNING, "%s request from unknown host %s for %s (%s)",
what, inet_ntoa(addr), path, epath);
break;
case no_entry:
xlog(L_WARNING, "refused %s request from %s for %s (%s): no export entry",
what, hp->h_name, path, epath);
break;
case not_exported:
xlog(L_WARNING, "refused %s request from %s for %s (%s): not exported",
what, hp->h_name, path, epath);
break;
case illegal_port:
xlog(L_WARNING, "refused %s request from %s for %s (%s): illegal port %d",
what, hp->h_name, path, epath, ntohs(caller->sin_port));
break;
case faked_hostent:
xlog(L_WARNING, "refused %s request from %s (%s) for %s (%s): DNS forward lookup does't match with reverse",
what, inet_ntoa(addr), hp->h_name, path, epath);
break;
case no_forward_dns:
xlog(L_WARNING, "refused %s request from %s (%s) for %s (%s): no DNS forward lookup",
what, inet_ntoa(addr), hp->h_name, path, epath);
break;
case success:
xlog(L_NOTICE, "authenticated %s request from %s:%d for %s (%s)",
what, hp->h_name, ntohs(caller->sin_port), path, epath);
break;
default:
xlog(L_NOTICE, "%s request from %s:%d for %s (%s) gave %d",
what, hp->h_name, ntohs(caller->sin_port), path, epath, error);
}
if (hp)
free (hp);
return exp;
}
static void
auth_fixpath(char *path)
{
char *sp, *cp;
for (sp = cp = path; *sp; sp++) {
if (*sp != '/' || sp[1] != '/')
*cp++ = *sp;
}
while (cp > path+1 && cp[-1] == '/')
cp--;
*cp = '\0';
}
|
