s3: smbd: Correctly canonicalize any incoming shadow copy path.

Converts to:

@GMT-token/path/last_component

from all incoming path types. Allows shadow_copy modules
to work when current directory is changed after removing
last component.

Ultimately when the VFS ABI is changed to add a timestamp
to struct smb_filename, this is where the parsing will be
done.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=12531

Signed-off-by: Jeremy Allison <jra@samba.org>
Reviewed-by: Uri Simchoni <uri@samba.org>

diff --git a/source3/smbd/filename.c b/source3/smbd/filename.c
index a8cfb55b0f09d21d0895b19a78d6ee26e1ff9f00..efe52a0432877d5052645a5e24322e4e5c73019e 100644 (file)
--- a/source3/smbd/filename.c
+++ b/source3/smbd/filename.c
@@ -220,6 +220,148 @@ static NTSTATUS check_parent_exists(TALLOC_CTX *ctx,
        return NT_STATUS_OK;
 }
 
+/*
+ * Re-order a known good @GMT-token path.
+ */
+
+static NTSTATUS rearrange_snapshot_path(struct smb_filename *smb_fname,
+                               char *startp,
+                               char *endp)
+{
+       size_t endlen = 0;
+       size_t gmt_len = endp - startp;
+       char gmt_store[gmt_len + 1];
+       char *parent = NULL;
+       const char *last_component = NULL;
+       char *newstr;
+       bool ret;
+
+       DBG_DEBUG("|%s| -> ", smb_fname->base_name);
+
+       /* Save off the @GMT-token. */
+       memcpy(gmt_store, startp, gmt_len);
+       gmt_store[gmt_len] = '\0';
+
+       if (*endp == '/') {
+               /* Remove any trailing '/' */
+               endp++;
+       }
+
+       if (*endp == '\0') {
+               /*
+                * @GMT-token was at end of path.
+                * Remove any preceeding '/'
+                */
+               if (startp > smb_fname->base_name && startp[-1] == '/') {
+                       startp--;
+               }
+       }
+
+       /* Remove @GMT-token from the path. */
+       endlen = strlen(endp);
+       memmove(startp, endp, endlen + 1);
+
+       /* Split the remaining path into components. */
+       ret = parent_dirname(smb_fname,
+                               smb_fname->base_name,
+                               &parent,
+                               &last_component);
+       if (ret == false) {
+               /* Must terminate debug with \n */
+               DBG_DEBUG("NT_STATUS_NO_MEMORY\n");
+               return NT_STATUS_NO_MEMORY;
+       }
+
+       if (ISDOT(parent)) {
+               if (last_component[0] == '\0') {
+                       newstr = talloc_strdup(smb_fname,
+                                       gmt_store);
+               } else {
+                       newstr = talloc_asprintf(smb_fname,
+                                       "%s/%s",
+                                       gmt_store,
+                                       last_component);
+               }
+       } else {
+               newstr = talloc_asprintf(smb_fname,
+                                       "%s/%s/%s",
+                                       gmt_store,
+                                       parent,
+                                       last_component);
+       }
+
+       TALLOC_FREE(parent);
+       TALLOC_FREE(smb_fname->base_name);
+       smb_fname->base_name = newstr;
+
+       DBG_DEBUG("|%s|\n", newstr);
+
+       return NT_STATUS_OK;
+}
+
+/*
+ * Canonicalize any incoming pathname potentially containining
+ * a @GMT-token into a path that looks like:
+ *
+ * @GMT-YYYY-MM-DD-HH-MM-SS/path/name/components/last_component
+ *
+ * Leaves single path @GMT-token -component alone:
+ *
+ * @GMT-YYYY-MM-DD-HH-MM-SS -> @GMT-YYYY-MM-DD-HH-MM-SS
+ *
+ * Eventually when struct smb_filename is updated and the VFS
+ * ABI is changed this will remove the @GMT-YYYY-MM-DD-HH-MM-SS
+ * and store in the struct smb_filename as a struct timeval field
+ * instead.
+ */
+
+static NTSTATUS canonicalize_snapshot_path(struct smb_filename *smb_fname)
+{
+       char *startp = strchr_m(smb_fname->base_name, '@');
+       char *endp = NULL;
+       struct tm tm;
+
+       if (startp == NULL) {
+               /* No @ */
+               return NT_STATUS_OK;
+       }
+
+       startp = strstr_m(startp, "@GMT-");
+       if (startp == NULL) {
+               /* No @ */
+               return NT_STATUS_OK;
+       }
+
+       if ((startp > smb_fname->base_name) && (startp[-1] != '/')) {
+               /* the GMT-token does not start a path-component */
+               return NT_STATUS_OK;
+       }
+
+       endp = strptime(startp, GMT_FORMAT, &tm);
+       if (endp == NULL) {
+               /* Not a valid timestring. */
+               return NT_STATUS_OK;
+       }
+
+       if ( endp[0] == '\0') {
+               return rearrange_snapshot_path(smb_fname,
+                                       startp,
+                                       endp);
+       }
+
+       if (endp[0] != '/') {
+               /*
+                * It is not a complete path component, i.e. the path
+                * component continues after the gmt-token.
+                */
+               return NT_STATUS_OK;
+       }
+
+       return rearrange_snapshot_path(smb_fname,
+                               startp,
+                               endp);
+}
+
 /****************************************************************************
 This routine is called to convert names from the dos namespace to unix
 namespace. It needs to handle any case conversions, mangling, format changes,
@@ -356,6 +498,14 @@ NTSTATUS unix_convert(TALLOC_CTX *ctx,
                goto err;
        }
 
+       /* Canonicalize any @GMT- paths. */
+       if (posix_pathnames == false) {
+               status = canonicalize_snapshot_path(smb_fname);
+               if (!NT_STATUS_IS_OK(status)) {
+                       goto err;
+               }
+       }
+
        /*
         * Large directory fix normalization. If we're case sensitive, and
         * the case preserving parameters are set to "no", normalize the case of