From 8daa83a594a2e98f39d764422bfbdbc62c9efd44 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 19:20:00 +0200 Subject: Adding upstream version 2:4.20.0+dfsg. Signed-off-by: Daniel Baumann --- source3/smbd/notify_inotify.c | 457 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 457 insertions(+) create mode 100644 source3/smbd/notify_inotify.c (limited to 'source3/smbd/notify_inotify.c') diff --git a/source3/smbd/notify_inotify.c b/source3/smbd/notify_inotify.c new file mode 100644 index 0000000..81fafc2 --- /dev/null +++ b/source3/smbd/notify_inotify.c @@ -0,0 +1,457 @@ +/* + 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 . +*/ + +/* + notify implementation using inotify +*/ + +#include "includes.h" +#include "../librpc/gen_ndr/notify.h" +#include "smbd/smbd.h" +#include "lib/util/sys_rw_data.h" + +#include + +/* 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; + void (*callback)(struct sys_notify_context *ctx, + void *private_data, + struct notify_event *ev, + uint32_t filter); + void *private_data; + uint32_t mask; /* the inotify mask */ + uint32_t filter; /* the windows completion filter */ + const char *path; +}; + + +/* + 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(uint32_t *filter) +{ + size_t i; + uint32_t out=0; + for (i=0;ifd); + return 0; +} + + +/* + 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) +{ + bool ok; + + DEBUG(10, ("filter_match: e->mask=%x, w->mask=%x, w->filter=%x\n", + e->mask, w->mask, w->filter)); + + 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) { + ok = ((w->filter & FILE_NOTIFY_CHANGE_DIR_NAME) != 0); + return ok; + } + + 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; + } + + ok = ((w->filter & FILE_NOTIFY_CHANGE_FILE_NAME) != 0); + return ok; +} + + + +/* + dispatch one inotify event + + the cookies are used to correctly handle renames +*/ +static void inotify_dispatch(struct inotify_private *in, + struct inotify_event *e, + int prev_wd, + uint32_t prev_cookie, + struct inotify_event *e2) +{ + struct inotify_watch_context *w, *next; + struct notify_event ne; + uint32_t filter; + + DEBUG(10, ("inotify_dispatch called with mask=%x, name=[%s]\n", + e->mask, e->len ? e->name : "")); + + /* 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 && + e2->wd == e->wd) { + ne.action = NOTIFY_ACTION_OLD_NAME; + } else { + ne.action = NOTIFY_ACTION_REMOVED; + } + } else if (e->mask & IN_MOVED_TO) { + if ((e->cookie == prev_cookie) && (e->wd == prev_wd)) { + ne.action = NOTIFY_ACTION_NEW_NAME; + } else { + ne.action = NOTIFY_ACTION_ADDED; + } + } else { + ne.action = NOTIFY_ACTION_MODIFIED; + } + ne.path = e->name; + + filter = inotify_map_mask_to_filter(e->mask); + + DBG_DEBUG("ne.action = %d, ne.path = %s, filter = %d\n", + ne.action, ne.path, filter); + + /* 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, filter); + } + } + + if ((ne.action == NOTIFY_ACTION_NEW_NAME) && + ((e->mask & IN_ISDIR) == 0)) { + + /* + * SMB expects a file rename to generate three events, two for + * the rename and the other for a modify of the + * destination. Strange! + */ + + 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, + filter); + } + } + } +} + +/* + 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; + int prev_wd = -1; + ssize_t ret; + + /* + 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")); + TALLOC_FREE(fde); + return; + } + + e0 = e = (struct inotify_event *)TALLOC_SIZE(in, bufsize + 1); + if (e == NULL) return; + ((uint8_t *)e)[bufsize] = '\0'; + + ret = read_data(in->fd, e0, bufsize); + if (ret != bufsize) { + DEBUG(0, ("Failed to read all inotify data - %s\n", + strerror(errno))); + talloc_free(e0); + /* the inotify fd will now be out of sync, + * can't keep reading data off it */ + TALLOC_FREE(fde); + return; + } + + /* we can get more than one event in the buffer */ + while (e && (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_wd, prev_cookie, e2); + prev_wd = e->wd; + 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 int inotify_setup(struct sys_notify_context *ctx) +{ + struct inotify_private *in; + struct tevent_fd *fde; + + in = talloc(ctx, struct inotify_private); + if (in == NULL) { + return ENOMEM; + } + + in->fd = inotify_init(); + if (in->fd == -1) { + int ret = errno; + DEBUG(0, ("Failed to init inotify - %s\n", strerror(ret))); + talloc_free(in); + return ret; + } + in->ctx = ctx; + in->watches = NULL; + + ctx->private_data = in; + talloc_set_destructor(in, inotify_destructor); + + /* 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 == NULL) { + ctx->private_data = NULL; + TALLOC_FREE(in); + return ENOMEM; + } + return 0; +} + +/* + 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); + + for (w=in->watches;w;w=w->next) { + if (w->wd == wd) { + /* + * Another inotify_watch_context listens on this path, + * leave the kernel level watch in place + */ + return 0; + } + } + + DEBUG(10, ("Deleting inotify watch %d\n", wd)); + if (inotify_rm_watch(in->fd, wd) == -1) { + DEBUG(1, ("inotify_rm_watch returned %s\n", strerror(errno))); + } + return 0; +} + + +/* + add a watch. The watch is removed when the caller calls + talloc_free() on *handle +*/ +int inotify_watch(TALLOC_CTX *mem_ctx, + struct sys_notify_context *ctx, + const char *path, + uint32_t *filter, + uint32_t *subdir_filter, + void (*callback)(struct sys_notify_context *ctx, + void *private_data, + struct notify_event *ev, + uint32_t filter), + void *private_data, + void *handle_p) +{ + struct inotify_private *in; + uint32_t mask; + struct inotify_watch_context *w; + uint32_t orig_filter = *filter; + void **handle = (void **)handle_p; + + /* maybe setup the inotify fd */ + if (ctx->private_data == NULL) { + int ret; + ret = inotify_setup(ctx); + if (ret != 0) { + return ret; + } + } + + in = talloc_get_type(ctx->private_data, struct inotify_private); + + mask = inotify_map(filter); + if (mask == 0) { + /* this filter can't be handled by inotify */ + return EINVAL; + } + + /* 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); + + w = talloc(mem_ctx, struct inotify_watch_context); + if (w == NULL) { + *filter = orig_filter; + return ENOMEM; + } + + w->in = in; + w->callback = callback; + w->private_data = private_data; + w->mask = mask; + w->filter = orig_filter; + w->path = talloc_strdup(w, path); + if (w->path == NULL) { + *filter = orig_filter; + TALLOC_FREE(w); + return ENOMEM; + } + + /* get a new watch descriptor for this path */ + w->wd = inotify_add_watch(in->fd, path, mask); + if (w->wd == -1) { + int err = errno; + *filter = orig_filter; + TALLOC_FREE(w); + DEBUG(1, ("inotify_add_watch returned %s\n", strerror(err))); + return err; + } + + DEBUG(10, ("inotify_add_watch for %s mask %x returned wd %d\n", + path, mask, w->wd)); + + (*handle) = w; + + DLIST_ADD(in->watches, w); + + /* the caller frees the handle to stop watching */ + talloc_set_destructor(w, watch_destructor); + + return 0; +} -- cgit v1.2.3