diff options
Diffstat (limited to 'source4/ntvfs/sysdep/inotify.c')
| -rw-r--r-- | source4/ntvfs/sysdep/inotify.c | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/source4/ntvfs/sysdep/inotify.c b/source4/ntvfs/sysdep/inotify.c new file mode 100644 index 0000000..94e0b17 --- /dev/null +++ b/source4/ntvfs/sysdep/inotify.c @@ -0,0 +1,398 @@ +/* + Unix SMB/CIFS implementation. + + Copyright (C) Andrew Tridgell 2006 + + 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/>. +*/ + +/* + notify implementation using inotify +*/ + +#include "includes.h" +#include "system/filesys.h" +#include <tevent.h> +#include "ntvfs/sysdep/sys_notify.h" +#include "../lib/util/dlinklist.h" +#include "libcli/raw/smb.h" +#include "param/param.h" + +#include <sys/inotify.h> + +/* glibc < 2.5 headers don't have these defines */ +#ifndef IN_ONLYDIR +#define IN_ONLYDIR 0x01000000 +#endif +#ifndef IN_MASK_ADD +#define IN_MASK_ADD 0x20000000 +#endif + +struct inotify_private { + struct sys_notify_context *ctx; + int fd; + struct inotify_watch_context *watches; +}; + +struct inotify_watch_context { + struct inotify_watch_context *next, *prev; + struct inotify_private *in; + int wd; + sys_notify_callback_t callback; + void *private_data; + uint32_t mask; /* the inotify mask */ + uint32_t filter; /* the windows completion filter */ + const char *path; +}; + + +/* + see if a particular event from inotify really does match a requested + notify event in SMB +*/ +static bool filter_match(struct inotify_watch_context *w, + struct inotify_event *e) +{ + if ((e->mask & w->mask) == 0) { + /* this happens because inotify_add_watch() coalesces watches on the same + path, oring their masks together */ + return false; + } + + /* SMB separates the filters for files and directories */ + if (e->mask & IN_ISDIR) { + if ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) == 0) { + return false; + } + } else { + if ((e->mask & IN_ATTRIB) && + (w->filter & (FILE_NOTIFY_CHANGE_ATTRIBUTES| + FILE_NOTIFY_CHANGE_LAST_WRITE| + FILE_NOTIFY_CHANGE_LAST_ACCESS| + FILE_NOTIFY_CHANGE_EA| + FILE_NOTIFY_CHANGE_SECURITY))) { + return true; + } + if ((e->mask & IN_MODIFY) && + (w->filter & FILE_NOTIFY_CHANGE_ATTRIBUTES)) { + return true; + } + if ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) == 0) { + return false; + } + } + + return true; +} + + + +/* + dispatch one inotify event + + the cookies are used to correctly handle renames +*/ +static void inotify_dispatch(struct inotify_private *in, + struct inotify_event *e, + uint32_t prev_cookie, + struct inotify_event *e2) +{ + struct inotify_watch_context *w, *next; + struct notify_event ne; + + /* ignore extraneous events, such as unmount and IN_IGNORED events */ + if ((e->mask & (IN_ATTRIB|IN_MODIFY|IN_CREATE|IN_DELETE| + IN_MOVED_FROM|IN_MOVED_TO)) == 0) { + return; + } + + /* map the inotify mask to a action. This gets complicated for + renames */ + if (e->mask & IN_CREATE) { + ne.action = NOTIFY_ACTION_ADDED; + } else if (e->mask & IN_DELETE) { + ne.action = NOTIFY_ACTION_REMOVED; + } else if (e->mask & IN_MOVED_FROM) { + if (e2 != NULL && e2->cookie == e->cookie) { + ne.action = NOTIFY_ACTION_OLD_NAME; + } else { + ne.action = NOTIFY_ACTION_REMOVED; + } + } else if (e->mask & IN_MOVED_TO) { + if (e->cookie == prev_cookie) { + ne.action = NOTIFY_ACTION_NEW_NAME; + } else { + ne.action = NOTIFY_ACTION_ADDED; + } + } else { + ne.action = NOTIFY_ACTION_MODIFIED; + } + ne.path = e->name; + + /* find any watches that have this watch descriptor */ + for (w=in->watches;w;w=next) { + next = w->next; + if (w->wd == e->wd && filter_match(w, e)) { + ne.dir = w->path; + w->callback(in->ctx, w->private_data, &ne); + } + } + + /* SMB expects a file rename to generate three events, two for + the rename and the other for a modify of the + destination. Strange! */ + if (ne.action != NOTIFY_ACTION_NEW_NAME || + (e->mask & IN_ISDIR) != 0) { + return; + } + + ne.action = NOTIFY_ACTION_MODIFIED; + e->mask = IN_ATTRIB; + + for (w=in->watches;w;w=next) { + next = w->next; + if (w->wd == e->wd && filter_match(w, e) && + !(w->filter & FILE_NOTIFY_CHANGE_CREATION)) { + ne.dir = w->path; + w->callback(in->ctx, w->private_data, &ne); + } + } +} + +/* + called when the kernel has some events for us +*/ +static void inotify_handler(struct tevent_context *ev, struct tevent_fd *fde, + uint16_t flags, void *private_data) +{ + struct inotify_private *in = talloc_get_type(private_data, + struct inotify_private); + int bufsize = 0; + struct inotify_event *e0, *e; + uint32_t prev_cookie=0; + + /* + we must use FIONREAD as we cannot predict the length of the + filenames, and thus can't know how much to allocate + otherwise + */ + if (ioctl(in->fd, FIONREAD, &bufsize) != 0 || + bufsize == 0) { + DEBUG(0,("No data on inotify fd?!\n")); + return; + } + + e0 = e = talloc_size(in, bufsize); + if (e == NULL) return; + + if (read(in->fd, e0, bufsize) != bufsize) { + DEBUG(0,("Failed to read all inotify data\n")); + talloc_free(e0); + return; + } + + /* we can get more than one event in the buffer */ + while (bufsize >= sizeof(*e)) { + struct inotify_event *e2 = NULL; + bufsize -= e->len + sizeof(*e); + if (bufsize >= sizeof(*e)) { + e2 = (struct inotify_event *)(e->len + sizeof(*e) + (char *)e); + } + inotify_dispatch(in, e, prev_cookie, e2); + prev_cookie = e->cookie; + e = e2; + } + + talloc_free(e0); +} + +/* + setup the inotify handle - called the first time a watch is added on + this context +*/ +static NTSTATUS inotify_setup(struct sys_notify_context *ctx) +{ + struct inotify_private *in; + struct tevent_fd *fde; + + in = talloc(ctx, struct inotify_private); + NT_STATUS_HAVE_NO_MEMORY(in); + + in->fd = inotify_init(); + if (in->fd == -1) { + DEBUG(0,("Failed to init inotify - %s\n", strerror(errno))); + talloc_free(in); + return map_nt_error_from_unix_common(errno); + } + in->ctx = ctx; + in->watches = NULL; + + ctx->private_data = in; + + /* add a event waiting for the inotify fd to be readable */ + fde = tevent_add_fd(ctx->ev, in, in->fd, + TEVENT_FD_READ, inotify_handler, in); + if (!fde) { + if (errno == 0) { + errno = ENOMEM; + } + DEBUG(0,("Failed to tevent_add_fd() - %s\n", strerror(errno))); + talloc_free(in); + return map_nt_error_from_unix_common(errno); + } + + tevent_fd_set_auto_close(fde); + + return NT_STATUS_OK; +} + + +/* + map from a change notify mask to a inotify mask. Remove any bits + which we can handle +*/ +static const struct { + uint32_t notify_mask; + uint32_t inotify_mask; +} inotify_mapping[] = { + {FILE_NOTIFY_CHANGE_FILE_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO}, + {FILE_NOTIFY_CHANGE_DIR_NAME, IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO}, + {FILE_NOTIFY_CHANGE_ATTRIBUTES, IN_ATTRIB|IN_MOVED_TO|IN_MOVED_FROM|IN_MODIFY}, + {FILE_NOTIFY_CHANGE_LAST_WRITE, IN_ATTRIB}, + {FILE_NOTIFY_CHANGE_LAST_ACCESS, IN_ATTRIB}, + {FILE_NOTIFY_CHANGE_EA, IN_ATTRIB}, + {FILE_NOTIFY_CHANGE_SECURITY, IN_ATTRIB} +}; + +static uint32_t inotify_map(struct notify_entry *e) +{ + int i; + uint32_t out=0; + for (i=0;i<ARRAY_SIZE(inotify_mapping);i++) { + if (inotify_mapping[i].notify_mask & e->filter) { + out |= inotify_mapping[i].inotify_mask; + e->filter &= ~inotify_mapping[i].notify_mask; + } + } + return out; +} + +/* + destroy a watch +*/ +static int watch_destructor(struct inotify_watch_context *w) +{ + struct inotify_private *in = w->in; + int wd = w->wd; + DLIST_REMOVE(w->in->watches, w); + + /* only rm the watch if its the last one with this wd */ + for (w=in->watches;w;w=w->next) { + if (w->wd == wd) break; + } + if (w == NULL) { + inotify_rm_watch(in->fd, wd); + } + return 0; +} + + +/* + add a watch. The watch is removed when the caller calls + talloc_free() on *handle +*/ +static NTSTATUS inotify_watch(struct sys_notify_context *ctx, + struct notify_entry *e, + sys_notify_callback_t callback, + void *private_data, + void *handle_p) +{ + struct inotify_private *in; + int wd; + uint32_t mask; + struct inotify_watch_context *w; + uint32_t filter = e->filter; + void **handle = (void **)handle_p; + + /* maybe setup the inotify fd */ + if (ctx->private_data == NULL) { + NTSTATUS status; + status = inotify_setup(ctx); + NT_STATUS_NOT_OK_RETURN(status); + } + + in = talloc_get_type(ctx->private_data, struct inotify_private); + + mask = inotify_map(e); + if (mask == 0) { + /* this filter can't be handled by inotify */ + return NT_STATUS_INVALID_PARAMETER; + } + + /* using IN_MASK_ADD allows us to cope with inotify() returning the same + watch descriptor for multiple watches on the same path */ + mask |= (IN_MASK_ADD | IN_ONLYDIR); + + /* get a new watch descriptor for this path */ + wd = inotify_add_watch(in->fd, e->path, mask); + if (wd == -1) { + e->filter = filter; + return map_nt_error_from_unix_common(errno); + } + + w = talloc(in, struct inotify_watch_context); + if (w == NULL) { + inotify_rm_watch(in->fd, wd); + e->filter = filter; + return NT_STATUS_NO_MEMORY; + } + + w->in = in; + w->wd = wd; + w->callback = callback; + w->private_data = private_data; + w->mask = mask; + w->filter = filter; + w->path = talloc_strdup(w, e->path); + if (w->path == NULL) { + inotify_rm_watch(in->fd, wd); + e->filter = filter; + return NT_STATUS_NO_MEMORY; + } + + (*handle) = w; + + DLIST_ADD(in->watches, w); + + /* the caller frees the handle to stop watching */ + talloc_set_destructor(w, watch_destructor); + + return NT_STATUS_OK; +} + + +static struct sys_notify_backend inotify = { + .name = "inotify", + .notify_watch = inotify_watch +}; + +/* + initialise the inotify module + */ +NTSTATUS sys_notify_inotify_init(TALLOC_CTX *); +NTSTATUS sys_notify_inotify_init(TALLOC_CTX *ctx) +{ + /* register ourselves as a system inotify module */ + return sys_notify_register(ctx, &inotify); +} |