From: Volker Lendecke Date: Thu, 22 Oct 2020 09:52:27 +0000 (+0200) Subject: notifyd: Add fcn_wait_send()/recv() X-Git-Tag: talloc-2.3.2~114 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=741428eaedeaf16edb7ecf3a367fe107d3631bc7;p=thirdparty%2Fsamba.git notifyd: Add fcn_wait_send()/recv() tevent_req based functions to listen for file change notifications. Mainly right now for testing purposes, but it could be used to also implement smbd's file change notify in a more tevent_req based fashion than it is implemented now. Signed-off-by: Volker Lendecke Reviewed-by: Jeremy Allison --- diff --git a/source3/smbd/notifyd/fcn_wait.c b/source3/smbd/notifyd/fcn_wait.c new file mode 100644 index 00000000000..e32240d911a --- /dev/null +++ b/source3/smbd/notifyd/fcn_wait.c @@ -0,0 +1,270 @@ +/* + * 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 . + */ + +#include "replace.h" +#include "fcn_wait.h" +#include "notifyd.h" +#include "lib/util/tevent_ntstatus.h" + +struct fcn_event { + struct fcn_event *prev, *next; + struct notify_event_msg msg; +}; + +struct fcn_wait_state { + struct tevent_context *ev; + struct messaging_context *msg_ctx; + struct server_id notifyd; + const char *path; + + struct tevent_req *recv_subreq; + + struct fcn_event *events; +}; + +static bool fcn_wait_cancel(struct tevent_req *req); +static void fcn_wait_cleanup( + struct tevent_req *req, enum tevent_req_state req_state); +static bool fcn_wait_filter(struct messaging_rec *rec, void *private_data); +static void fcn_wait_done(struct tevent_req *subreq); + +struct tevent_req *fcn_wait_send( + TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct messaging_context *msg_ctx, + struct server_id notifyd, + const char *path, + uint32_t filter, + uint32_t subdir_filter) +{ + struct tevent_req *req = NULL; + struct fcn_wait_state *state = NULL; + struct notify_rec_change_msg msg = { + .instance.filter = filter, + .instance.subdir_filter = subdir_filter, + }; + struct iovec iov[2]; + NTSTATUS status; + + req = tevent_req_create(mem_ctx, &state, struct fcn_wait_state); + if (req == NULL) { + return NULL; + } + state->ev = ev; + state->msg_ctx = msg_ctx; + state->notifyd = notifyd; + state->path = path; + + state->recv_subreq = messaging_filtered_read_send( + state, ev, msg_ctx, fcn_wait_filter, req); + if (tevent_req_nomem(state->recv_subreq, req)) { + return tevent_req_post(req, ev); + } + tevent_req_set_callback(state->recv_subreq, fcn_wait_done, req); + tevent_req_set_cleanup_fn(req, fcn_wait_cleanup); + + clock_gettime_mono(&msg.instance.creation_time); + msg.instance.private_data = state; + + iov[0].iov_base = &msg; + iov[0].iov_len = offsetof(struct notify_rec_change_msg, path); + iov[1].iov_base = discard_const_p(char, path); + iov[1].iov_len = strlen(path)+1; + + status = messaging_send_iov( + msg_ctx, /* msg_ctx */ + notifyd, /* dst */ + MSG_SMB_NOTIFY_REC_CHANGE, /* mst_type */ + iov, /* iov */ + ARRAY_SIZE(iov), /* iovlen */ + NULL, /* fds */ + 0); /* num_fds */ + if (tevent_req_nterror(req, status)) { + DBG_DEBUG("messaging_send_iov failed: %s\n", + nt_errstr(status)); + return tevent_req_post(req, ev); + } + tevent_req_set_cancel_fn(req, fcn_wait_cancel); + + return req; +} + +static bool fcn_wait_cancel(struct tevent_req *req) +{ + struct fcn_wait_state *state = tevent_req_data( + req, struct fcn_wait_state); + struct notify_rec_change_msg msg = { + .instance.filter = 0, /* filter==0 is a delete msg */ + .instance.subdir_filter = 0, + }; + struct iovec iov[2]; + NTSTATUS status; + + clock_gettime_mono(&msg.instance.creation_time); + msg.instance.private_data = state; + + iov[0].iov_base = &msg; + iov[0].iov_len = offsetof(struct notify_rec_change_msg, path); + iov[1].iov_base = discard_const_p(char, state->path); + iov[1].iov_len = strlen(state->path)+1; + + status = messaging_send_iov( + state->msg_ctx, /* msg_ctx */ + state->notifyd, /* dst */ + MSG_SMB_NOTIFY_REC_CHANGE, /* mst_type */ + iov, /* iov */ + ARRAY_SIZE(iov), /* iovlen */ + NULL, /* fds */ + 0); /* num_fds */ + if (!NT_STATUS_IS_OK(status)) { + DBG_DEBUG("messaging_send_iov failed: %s\n", + nt_errstr(status)); + return false; + } + + fcn_wait_cleanup(req, 0); /* fcn_wait_cleanup ignores req_state */ + tevent_req_defer_callback(req, state->ev); + tevent_req_nterror(req, NT_STATUS_CANCELLED); + + return true; +} + +static void fcn_wait_cleanup( + struct tevent_req *req, enum tevent_req_state req_state) +{ + struct fcn_wait_state *state = tevent_req_data( + req, struct fcn_wait_state); + TALLOC_FREE(state->recv_subreq); +} + +static bool fcn_wait_filter(struct messaging_rec *rec, void *private_data) +{ + struct tevent_req *req = talloc_get_type_abort( + private_data, struct tevent_req); + struct fcn_wait_state *state = tevent_req_data( + req, struct fcn_wait_state); + struct notify_event_msg msg = { .action = 0 }; + struct fcn_event *evt = NULL; + + if (rec->msg_type != MSG_PVFS_NOTIFY) { + DBG_DEBUG("Ignoring msg %"PRIu32"\n", rec->msg_type); + return false; + } + + /* + * We need at least the trailing '\0' for the path + */ + if (rec->buf.length < (offsetof(struct notify_event_msg, path) + 1)) { + DBG_DEBUG("Ignoring short (%zu) msg\n", rec->buf.length); + return false; + } + if (rec->buf.data[rec->buf.length-1] != '\0') { + DBG_DEBUG("Expected 0-terminated path\n"); + return false; + } + + memcpy(&msg, rec->buf.data, sizeof(msg)); + + if (msg.private_data != state) { + DBG_DEBUG("Got private_data=%p, expected %p\n", + msg.private_data, + state); + return false; + } + + evt = talloc_memdup(state, rec->buf.data, rec->buf.length); + if (evt == NULL) { + DBG_DEBUG("talloc_memdup failed\n"); + return false; + } + talloc_set_name_const(evt, "struct fcn_event"); + + /* + * TODO: Sort by timestamp + */ + + DLIST_ADD_END(state->events, evt); + + tevent_req_defer_callback(req, state->ev); + tevent_req_notify_callback(req); + + return false; +} + +static void fcn_wait_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data( + subreq, struct tevent_req); + int ret; + + ret = messaging_filtered_read_recv(subreq, NULL, NULL); + TALLOC_FREE(subreq); + if (ret != 0) { + DBG_DEBUG("messaging_filtered_read failed: %s\n", + strerror(ret)); + tevent_req_nterror(req, map_nt_error_from_unix(ret)); + return; + } + + /* + * We should never have gotten here, all work is done from the + * filter function. + */ + tevent_req_nterror(req, NT_STATUS_INTERNAL_ERROR); +} + +NTSTATUS fcn_wait_recv( + struct tevent_req *req, + TALLOC_CTX *mem_ctx, + struct timespec *when, + uint32_t *action, + char **path) +{ + struct fcn_wait_state *state = tevent_req_data( + req, struct fcn_wait_state); + struct fcn_event *evt = NULL; + NTSTATUS status; + + if (!tevent_req_is_in_progress(req) && + tevent_req_is_nterror(req, &status)) { + return status; + } + evt = state->events; + if (evt == NULL) { + return NT_STATUS_RETRY; + } + + if (path != NULL) { + *path = talloc_strdup(mem_ctx, evt->msg.path); + if ((*path) == NULL) { + return NT_STATUS_NO_MEMORY; + } + } + if (when != NULL) { + *when = evt->msg.when; + } + if (action != NULL) { + *action = evt->msg.action; + } + + DLIST_REMOVE(state->events, evt); + + if (state->events != NULL) { + tevent_req_defer_callback(req, state->ev); + tevent_req_notify_callback(req); + } + + return NT_STATUS_OK; +} diff --git a/source3/smbd/notifyd/fcn_wait.h b/source3/smbd/notifyd/fcn_wait.h new file mode 100644 index 00000000000..daadee4fe05 --- /dev/null +++ b/source3/smbd/notifyd/fcn_wait.h @@ -0,0 +1,38 @@ +/* + * 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 . + */ + +#ifndef __NOTIFYD_FCN_WAIT_H__ +#define __NOTIFYD_FCN_WAIT_H__ + +#include "replace.h" +#include "messages.h" +#include "librpc/gen_ndr/server_id.h" + +struct tevent_req *fcn_wait_send( + TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct messaging_context *msg_ctx, + struct server_id notifyd, + const char *path, + uint32_t filter, + uint32_t subdir_filter); +NTSTATUS fcn_wait_recv( + struct tevent_req *req, + TALLOC_CTX *mem_ctx, + struct timespec *when, + uint32_t *action, + char **path); + +#endif diff --git a/source3/smbd/notifyd/wscript_build b/source3/smbd/notifyd/wscript_build index 8d549bd0d25..43b9b76843e 100644 --- a/source3/smbd/notifyd/wscript_build +++ b/source3/smbd/notifyd/wscript_build @@ -1,5 +1,9 @@ #!/usr/bin/env python +bld.SAMBA3_SUBSYSTEM('fcn_wait', + source='fcn_wait.c', + deps='samba3core') + bld.SAMBA3_SUBSYSTEM('notifyd_db', source='notifyd_entry.c notifyd_db.c', deps='samba-debug dbwrap errors3')