source: branches/samba-3.2.x/source/modules/vfs_expand_msdfs.c

Last change on this file was 133, checked in by Paul Smedley, 17 years ago

Update trunk to 3.2.0pre3
File size: 5.0 KB
Line 
1/*
2 * Expand msdfs targets based on client IP
3 *
4 * Copyright (C) Volker Lendecke, 2004
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 3 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, see <http://www.gnu.org/licenses/>.
18 */
19
20#include "includes.h"
21
22#undef DBGC_CLASS
23#define DBGC_CLASS DBGC_VFS
24
25extern userdom_struct current_user_info;
26
27/**********************************************************
28 Under mapfile we expect a table of the following format:
29
30 IP-Prefix whitespace expansion
31
32 For example:
33 192.168.234 local.samba.org
34 192.168 remote.samba.org
35 default.samba.org
36
37 This is to redirect a DFS client to a host close to it.
38***********************************************************/
39
40static char *read_target_host(TALLOC_CTX *ctx, const char *mapfile)
41{
42 XFILE *f;
43 char buf[1024];
44 char *space = buf;
45 bool found = false;
46
47 f = x_fopen(mapfile, O_RDONLY, 0);
48
49 if (f == NULL) {
50 DEBUG(0,("can't open IP map %s. Error %s\n",
51 mapfile, strerror(errno) ));
52 return NULL;
53 }
54
55 DEBUG(10, ("Scanning mapfile [%s]\n", mapfile));
56
57 while (x_fgets(buf, sizeof(buf), f) != NULL) {
58 char addr[INET6_ADDRSTRLEN];
59
60 if ((strlen(buf) > 0) && (buf[strlen(buf)-1] == '\n'))
61 buf[strlen(buf)-1] = '\0';
62
63 DEBUG(10, ("Scanning line [%s]\n", buf));
64
65 space = strchr_m(buf, ' ');
66
67 if (space == NULL) {
68 DEBUG(0, ("Ignoring invalid line %s\n", buf));
69 continue;
70 }
71
72 *space = '\0';
73
74 if (strncmp(client_addr(get_client_fd(),addr,sizeof(addr)),
75 buf, strlen(buf)) == 0) {
76 found = true;
77 break;
78 }
79 }
80
81 x_fclose(f);
82
83 if (!found) {
84 return NULL;
85 }
86
87 space += 1;
88
89 while (isspace(*space))
90 space += 1;
91
92 return talloc_strdup(ctx, space);
93}
94
95/**********************************************************
96
97 Expand the msdfs target host using read_target_host
98 explained above. The syntax used in the msdfs link is
99
100 msdfs:@table-filename@/share
101
102 Everything between and including the two @-signs is
103 replaced by the substitution string found in the table
104 described above.
105
106***********************************************************/
107
108static char *expand_msdfs_target(TALLOC_CTX *ctx,
109 connection_struct *conn,
110 char *target)
111{
112 char *mapfilename = NULL;
113 char *filename_start = strchr_m(target, '@');
114 char *filename_end = NULL;
115 int filename_len = 0;
116 char *targethost = NULL;
117 char *new_target = NULL;
118
119 if (filename_start == NULL) {
120 DEBUG(10, ("No filename start in %s\n", target));
121 return NULL;
122 }
123
124 filename_end = strchr_m(filename_start+1, '@');
125
126 if (filename_end == NULL) {
127 DEBUG(10, ("No filename end in %s\n", target));
128 return NULL;
129 }
130
131 filename_len = PTR_DIFF(filename_end, filename_start+1);
132 mapfilename = talloc_strdup(ctx, filename_start+1);
133 if (!mapfilename) {
134 return NULL;
135 }
136 mapfilename[filename_len] = '\0';
137
138 DEBUG(10, ("Expanding from table [%s]\n", mapfilename));
139
140 if ((targethost = read_target_host(ctx, mapfilename)) == NULL) {
141 DEBUG(1, ("Could not expand target host from file %s\n",
142 mapfilename));
143 return NULL;
144 }
145
146 targethost = talloc_sub_advanced(ctx,
147 lp_servicename(SNUM(conn)),
148 conn->user,
149 conn->connectpath,
150 conn->gid,
151 get_current_username(),
152 current_user_info.domain,
153 targethost);
154
155 DEBUG(10, ("Expanded targethost to %s\n", targethost));
156
157 /* Replace the part between '@...@' */
158 *filename_start = '\0';
159 new_target = talloc_asprintf(ctx,
160 "%s%s%s",
161 target,
162 targethost,
163 filename_end+1);
164 if (!new_target) {
165 return NULL;
166 }
167
168 DEBUG(10, ("New DFS target: %s\n", new_target));
169 return new_target;
170}
171
172static int expand_msdfs_readlink(struct vfs_handle_struct *handle,
173 const char *path, char *buf, size_t bufsiz)
174{
175 TALLOC_CTX *ctx = talloc_tos();
176 int result;
177 char *target = TALLOC_ARRAY(ctx, char, PATH_MAX+1);
178
179 if (!target) {
180 errno = ENOMEM;
181 return -1;
182 }
183 result = SMB_VFS_NEXT_READLINK(handle, path, target,
184 PATH_MAX);
185
186 if (result < 0)
187 return result;
188
189 target[result] = '\0';
190
191 if ((strncmp(target, "msdfs:", strlen("msdfs:")) == 0) &&
192 (strchr_m(target, '@') != NULL)) {
193 target = expand_msdfs_target(ctx, handle->conn, target);
194 if (!target) {
195 errno = ENOENT;
196 return -1;
197 }
198 }
199
200 safe_strcpy(buf, target, bufsiz-1);
201 return strlen(buf);
202}
203
204/* VFS operations structure */
205
206static vfs_op_tuple expand_msdfs_ops[] = {
207 {SMB_VFS_OP(expand_msdfs_readlink), SMB_VFS_OP_READLINK,
208 SMB_VFS_LAYER_TRANSPARENT},
209 {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
210};
211
212NTSTATUS vfs_expand_msdfs_init(void);
213NTSTATUS vfs_expand_msdfs_init(void)
214{
215 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "expand_msdfs",
216 expand_msdfs_ops);
217}
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