diff options
Diffstat (limited to 'source3/modules/vfs_expand_msdfs.c')
| -rw-r--r-- | source3/modules/vfs_expand_msdfs.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/source3/modules/vfs_expand_msdfs.c b/source3/modules/vfs_expand_msdfs.c new file mode 100644 index 0000000000..0d09d213e1 --- /dev/null +++ b/source3/modules/vfs_expand_msdfs.c @@ -0,0 +1,215 @@ +/* + * Expand msdfs targets based on client IP + * + * Copyright (C) Volker Lendecke, 2004 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 3 of the License, or + * (at your option) any later version. + * + * This program 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 General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include "includes.h" + +#undef DBGC_CLASS +#define DBGC_CLASS DBGC_VFS + +/********************************************************** + Under mapfile we expect a table of the following format: + + IP-Prefix whitespace expansion + + For example: + 192.168.234 local.samba.org + 192.168 remote.samba.org + default.samba.org + + This is to redirect a DFS client to a host close to it. +***********************************************************/ + +static char *read_target_host(TALLOC_CTX *ctx, const char *mapfile) +{ + XFILE *f; + char buf[1024]; + char *space = buf; + bool found = false; + + f = x_fopen(mapfile, O_RDONLY, 0); + + if (f == NULL) { + DEBUG(0,("can't open IP map %s. Error %s\n", + mapfile, strerror(errno) )); + return NULL; + } + + DEBUG(10, ("Scanning mapfile [%s]\n", mapfile)); + + while (x_fgets(buf, sizeof(buf), f) != NULL) { + char addr[INET6_ADDRSTRLEN]; + + if ((strlen(buf) > 0) && (buf[strlen(buf)-1] == '\n')) + buf[strlen(buf)-1] = '\0'; + + DEBUG(10, ("Scanning line [%s]\n", buf)); + + space = strchr_m(buf, ' '); + + if (space == NULL) { + DEBUG(0, ("Ignoring invalid line %s\n", buf)); + continue; + } + + *space = '\0'; + + if (strncmp(client_addr(get_client_fd(),addr,sizeof(addr)), + buf, strlen(buf)) == 0) { + found = true; + break; + } + } + + x_fclose(f); + + if (!found) { + return NULL; + } + + space += 1; + + while (isspace(*space)) + space += 1; + + return talloc_strdup(ctx, space); +} + +/********************************************************** + + Expand the msdfs target host using read_target_host + explained above. The syntax used in the msdfs link is + + msdfs:@table-filename@/share + + Everything between and including the two @-signs is + replaced by the substitution string found in the table + described above. + +***********************************************************/ + +static char *expand_msdfs_target(TALLOC_CTX *ctx, + connection_struct *conn, + char *target) +{ + char *mapfilename = NULL; + char *filename_start = strchr_m(target, '@'); + char *filename_end = NULL; + int filename_len = 0; + char *targethost = NULL; + char *new_target = NULL; + + if (filename_start == NULL) { + DEBUG(10, ("No filename start in %s\n", target)); + return NULL; + } + + filename_end = strchr_m(filename_start+1, '@'); + + if (filename_end == NULL) { + DEBUG(10, ("No filename end in %s\n", target)); + return NULL; + } + + filename_len = PTR_DIFF(filename_end, filename_start+1); + mapfilename = talloc_strdup(ctx, filename_start+1); + if (!mapfilename) { + return NULL; + } + mapfilename[filename_len] = '\0'; + + DEBUG(10, ("Expanding from table [%s]\n", mapfilename)); + + if ((targethost = read_target_host(ctx, mapfilename)) == NULL) { + DEBUG(1, ("Could not expand target host from file %s\n", + mapfilename)); + return NULL; + } + + targethost = talloc_sub_advanced(ctx, + lp_servicename(SNUM(conn)), + conn->server_info->unix_name, + conn->connectpath, + conn->server_info->utok.gid, + conn->server_info->sanitized_username, + pdb_get_domain(conn->server_info->sam_account), + targethost); + + DEBUG(10, ("Expanded targethost to %s\n", targethost)); + + /* Replace the part between '@...@' */ + *filename_start = '\0'; + new_target = talloc_asprintf(ctx, + "%s%s%s", + target, + targethost, + filename_end+1); + if (!new_target) { + return NULL; + } + + DEBUG(10, ("New DFS target: %s\n", new_target)); + return new_target; +} + +static int expand_msdfs_readlink(struct vfs_handle_struct *handle, + const char *path, char *buf, size_t bufsiz) +{ + TALLOC_CTX *ctx = talloc_tos(); + int result; + char *target = TALLOC_ARRAY(ctx, char, PATH_MAX+1); + + if (!target) { + errno = ENOMEM; + return -1; + } + result = SMB_VFS_NEXT_READLINK(handle, path, target, + PATH_MAX); + + if (result < 0) + return result; + + target[result] = '\0'; + + if ((strncmp(target, "msdfs:", strlen("msdfs:")) == 0) && + (strchr_m(target, '@') != NULL)) { + target = expand_msdfs_target(ctx, handle->conn, target); + if (!target) { + errno = ENOENT; + return -1; + } + } + + safe_strcpy(buf, target, bufsiz-1); + return strlen(buf); +} + +/* VFS operations structure */ + +static vfs_op_tuple expand_msdfs_ops[] = { + {SMB_VFS_OP(expand_msdfs_readlink), SMB_VFS_OP_READLINK, + SMB_VFS_LAYER_TRANSPARENT}, + {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP} +}; + +NTSTATUS vfs_expand_msdfs_init(void); +NTSTATUS vfs_expand_msdfs_init(void) +{ + return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "expand_msdfs", + expand_msdfs_ops); +} |