diff options
author | Ralph Boehme <slow@samba.org> | 2018-11-23 14:08:15 +0100 |
---|---|---|
committer | Karolin Seeger <kseeger@samba.org> | 2018-12-13 13:48:26 +0100 |
commit | 06336d8a59e1d25a06834c1df0b73817c822353b (patch) | |
tree | a57ce3ea407444a63657ad6afdd2f57b9a1a45c2 /source3/modules | |
parent | eae534f01cae6ea6fa875bae15f11dd0006b406e (diff) | |
download | samba-06336d8a59e1d25a06834c1df0b73817c822353b.tar.gz |
vfs_shadow_copy2: nicely deal with attempts to open previous version for writing
Bug: https://bugzilla.samba.org/show_bug.cgi?id=13688
Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: Jeremy Allison <jra@samba.org>
(cherry picked from commit cf95756235f718478e556ce1fbf7c032f9c9acfb)
Diffstat (limited to 'source3/modules')
-rw-r--r-- | source3/modules/vfs_shadow_copy2.c | 124 |
1 files changed, 122 insertions, 2 deletions
diff --git a/source3/modules/vfs_shadow_copy2.c b/source3/modules/vfs_shadow_copy2.c index ebda08678ea..a88930b1c02 100644 --- a/source3/modules/vfs_shadow_copy2.c +++ b/source3/modules/vfs_shadow_copy2.c @@ -36,6 +36,8 @@ #include "include/ntioctl.h" #include "util_tdb.h" #include "lib/util_path.h" +#include "libcli/security/security.h" +#include "lib/util/tevent_unix.h" struct shadow_copy2_config { char *gmt_format; @@ -1376,15 +1378,27 @@ static int shadow_copy2_open(vfs_handle_struct *handle, time_t timestamp = 0; char *stripped = NULL; char *tmp; + bool is_converted = false; int saved_errno = 0; int ret; - if (!shadow_copy2_strip_snapshot(talloc_tos(), handle, + if (!shadow_copy2_strip_snapshot_converted(talloc_tos(), handle, smb_fname->base_name, - ×tamp, &stripped)) { + ×tamp, &stripped, + &is_converted)) { return -1; } if (timestamp == 0) { + if (is_converted) { + /* + * Just pave over the user requested mode and use + * O_RDONLY. Later attempts by the client to write on + * the handle will fail in the pwrite() syscall with + * EINVAL which we carefully map to EROFS. In sum, this + * matches Windows behaviour. + */ + flags = O_RDONLY; + } return SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode); } @@ -1398,6 +1412,14 @@ static int shadow_copy2_open(vfs_handle_struct *handle, return -1; } + /* + * Just pave over the user requested mode and use O_RDONLY. Later + * attempts by the client to write on the handle will fail in the + * pwrite() syscall with EINVAL which we carefully map to EROFS. In sum, + * this matches Windows behaviour. + */ + flags = O_RDONLY; + ret = SMB_VFS_NEXT_OPEN(handle, smb_fname, fsp, flags, mode); if (ret == -1) { saved_errno = errno; @@ -2935,6 +2957,101 @@ static int shadow_copy2_get_quota(vfs_handle_struct *handle, return ret; } +static ssize_t shadow_copy2_pwrite(vfs_handle_struct *handle, + files_struct *fsp, + const void *data, + size_t n, + off_t offset) +{ + ssize_t nwritten; + + nwritten = SMB_VFS_NEXT_PWRITE(handle, fsp, data, n, offset); + if (nwritten == -1) { + if (errno == EBADF && fsp->can_write) { + errno = EROFS; + } + } + + return nwritten; +} + +struct shadow_copy2_pwrite_state { + vfs_handle_struct *handle; + files_struct *fsp; + ssize_t ret; + struct vfs_aio_state vfs_aio_state; +}; + +static void shadow_copy2_pwrite_done(struct tevent_req *subreq); + +static struct tevent_req *shadow_copy2_pwrite_send( + struct vfs_handle_struct *handle, TALLOC_CTX *mem_ctx, + struct tevent_context *ev, struct files_struct *fsp, + const void *data, size_t n, off_t offset) +{ + struct tevent_req *req = NULL, *subreq = NULL; + struct shadow_copy2_pwrite_state *state = NULL; + + req = tevent_req_create(mem_ctx, &state, + struct shadow_copy2_pwrite_state); + if (req == NULL) { + return NULL; + } + state->handle = handle; + state->fsp = fsp; + + subreq = SMB_VFS_NEXT_PWRITE_SEND(state, + ev, + handle, + fsp, + data, + n, + offset); + if (tevent_req_nomem(subreq, req)) { + return tevent_req_post(req, ev); + } + tevent_req_set_callback(subreq, shadow_copy2_pwrite_done, req); + + return req; +} + +static void shadow_copy2_pwrite_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data( + subreq, struct tevent_req); + struct shadow_copy2_pwrite_state *state = tevent_req_data( + req, struct shadow_copy2_pwrite_state); + + state->ret = SMB_VFS_PWRITE_RECV(subreq, &state->vfs_aio_state); + TALLOC_FREE(subreq); + if (state->ret == -1) { + tevent_req_error(req, state->vfs_aio_state.error); + return; + } + + tevent_req_done(req); +} + +static ssize_t shadow_copy2_pwrite_recv(struct tevent_req *req, + struct vfs_aio_state *vfs_aio_state) +{ + struct shadow_copy2_pwrite_state *state = tevent_req_data( + req, struct shadow_copy2_pwrite_state); + + if (tevent_req_is_unix_error(req, &vfs_aio_state->error)) { + if ((vfs_aio_state->error == EBADF) && + state->fsp->can_write) + { + vfs_aio_state->error = EROFS; + errno = EROFS; + } + return -1; + } + + *vfs_aio_state = state->vfs_aio_state; + return state->ret; +} + static int shadow_copy2_connect(struct vfs_handle_struct *handle, const char *service, const char *user) { @@ -3298,6 +3415,9 @@ static struct vfs_fn_pointers vfs_shadow_copy2_fns = { .chmod_acl_fn = shadow_copy2_chmod_acl, .chflags_fn = shadow_copy2_chflags, .get_real_filename_fn = shadow_copy2_get_real_filename, + .pwrite_fn = shadow_copy2_pwrite, + .pwrite_send_fn = shadow_copy2_pwrite_send, + .pwrite_recv_fn = shadow_copy2_pwrite_recv, .connectpath_fn = shadow_copy2_connectpath, }; |