source: branches/samba-3.3.x/source/modules/vfs_expand_msdfs.c@ 221

Last change on this file since 221 was 206, checked in by Herwig Bauernfeind, 17 years ago

Import Samba 3.3 branch at 3.0.0 level (psmedley's port)
File size: 5.1 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
25/**********************************************************
26 Under mapfile we expect a table of the following format:
27
28 IP-Prefix whitespace expansion
29
30 For example:
31 192.168.234 local.samba.org
32 192.168 remote.samba.org
33 default.samba.org
34
35 This is to redirect a DFS client to a host close to it.
36***********************************************************/
37
38static char *read_target_host(TALLOC_CTX *ctx, const char *mapfile)
39{
40 XFILE *f;
41 char buf[1024];
42 char *space = buf;
43 bool found = false;
44
45 f = x_fopen(mapfile, O_RDONLY, 0);
46
47 if (f == NULL) {
48 DEBUG(0,("can't open IP map %s. Error %s\n",
49 mapfile, strerror(errno) ));
50 return NULL;
51 }
52
53 DEBUG(10, ("Scanning mapfile [%s]\n", mapfile));
54
55 while (x_fgets(buf, sizeof(buf), f) != NULL) {
56 char addr[INET6_ADDRSTRLEN];
57
58 if ((strlen(buf) > 0) && (buf[strlen(buf)-1] == '\n'))
59 buf[strlen(buf)-1] = '\0';
60
61 DEBUG(10, ("Scanning line [%s]\n", buf));
62
63 space = strchr_m(buf, ' ');
64
65 if (space == NULL) {
66 DEBUG(0, ("Ignoring invalid line %s\n", buf));
67 continue;
68 }
69
70 *space = '\0';
71
72 if (strncmp(client_addr(get_client_fd(),addr,sizeof(addr)),
73 buf, strlen(buf)) == 0) {
74 found = true;
75 break;
76 }
77 }
78
79 x_fclose(f);
80
81 if (!found) {
82 return NULL;
83 }
84
85 space += 1;
86
87 while (isspace(*space))
88 space += 1;
89
90 return talloc_strdup(ctx, space);
91}
92
93/**********************************************************
94
95 Expand the msdfs target host using read_target_host
96 explained above. The syntax used in the msdfs link is
97
98 msdfs:@table-filename@/share
99
100 Everything between and including the two @-signs is
101 replaced by the substitution string found in the table
102 described above.
103
104***********************************************************/
105
106static char *expand_msdfs_target(TALLOC_CTX *ctx,
107 connection_struct *conn,
108 char *target)
109{
110 char *mapfilename = NULL;
111 char *filename_start = strchr_m(target, '@');
112 char *filename_end = NULL;
113 int filename_len = 0;
114 char *targethost = NULL;
115 char *new_target = NULL;
116
117 if (filename_start == NULL) {
118 DEBUG(10, ("No filename start in %s\n", target));
119 return NULL;
120 }
121
122 filename_end = strchr_m(filename_start+1, '@');
123
124 if (filename_end == NULL) {
125 DEBUG(10, ("No filename end in %s\n", target));
126 return NULL;
127 }
128
129 filename_len = PTR_DIFF(filename_end, filename_start+1);
130 mapfilename = talloc_strdup(ctx, filename_start+1);
131 if (!mapfilename) {
132 return NULL;
133 }
134 mapfilename[filename_len] = '\0';
135
136 DEBUG(10, ("Expanding from table [%s]\n", mapfilename));
137
138 if ((targethost = read_target_host(ctx, mapfilename)) == NULL) {
139 DEBUG(1, ("Could not expand target host from file %s\n",
140 mapfilename));
141 return NULL;
142 }
143
144 targethost = talloc_sub_advanced(ctx,
145 lp_servicename(SNUM(conn)),
146 conn->server_info->unix_name,
147 conn->connectpath,
148 conn->server_info->utok.gid,
149 conn->server_info->sanitized_username,
150 pdb_get_domain(conn->server_info->sam_account),
151 targethost);
152
153 DEBUG(10, ("Expanded targethost to %s\n", targethost));
154
155 /* Replace the part between '@...@' */
156 *filename_start = '\0';
157 new_target = talloc_asprintf(ctx,
158 "%s%s%s",
159 target,
160 targethost,
161 filename_end+1);
162 if (!new_target) {
163 return NULL;
164 }
165
166 DEBUG(10, ("New DFS target: %s\n", new_target));
167 return new_target;
168}
169
170static int expand_msdfs_readlink(struct vfs_handle_struct *handle,
171 const char *path, char *buf, size_t bufsiz)
172{
173 TALLOC_CTX *ctx = talloc_tos();
174 int result;
175 char *target = TALLOC_ARRAY(ctx, char, PATH_MAX+1);
176
177 if (!target) {
178 errno = ENOMEM;
179 return -1;
180 }
181 result = SMB_VFS_NEXT_READLINK(handle, path, target,
182 PATH_MAX);
183
184 if (result < 0)
185 return result;
186
187 target[result] = '\0';
188
189 if ((strncmp(target, "msdfs:", strlen("msdfs:")) == 0) &&
190 (strchr_m(target, '@') != NULL)) {
191 target = expand_msdfs_target(ctx, handle->conn, target);
192 if (!target) {
193 errno = ENOENT;
194 return -1;
195 }
196 }
197
198 safe_strcpy(buf, target, bufsiz-1);
199 return strlen(buf);
200}
201
202/* VFS operations structure */
203
204static vfs_op_tuple expand_msdfs_ops[] = {
205 {SMB_VFS_OP(expand_msdfs_readlink), SMB_VFS_OP_READLINK,
206 SMB_VFS_LAYER_TRANSPARENT},
207 {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
208};
209
210NTSTATUS vfs_expand_msdfs_init(void);
211NTSTATUS vfs_expand_msdfs_init(void)
212{
213 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "expand_msdfs",
214 expand_msdfs_ops);
215}
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