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Diffstat (limited to 'source3/lib/messages.c')
| -rw-r--r-- | source3/lib/messages.c | 1480 |
1 files changed, 1480 insertions, 0 deletions
diff --git a/source3/lib/messages.c b/source3/lib/messages.c new file mode 100644 index 0000000..7d3d469 --- /dev/null +++ b/source3/lib/messages.c @@ -0,0 +1,1480 @@ +/* + Unix SMB/CIFS implementation. + Samba internal messaging functions + Copyright (C) Andrew Tridgell 2000 + Copyright (C) 2001 by Martin Pool + Copyright (C) 2002 by Jeremy Allison + Copyright (C) 2007 by Volker Lendecke + + 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/>. +*/ + +/** + @defgroup messages Internal messaging framework + @{ + @file messages.c + + @brief Module for internal messaging between Samba daemons. + + The idea is that if a part of Samba wants to do communication with + another Samba process then it will do a message_register() of a + dispatch function, and use message_send_pid() to send messages to + that process. + + The dispatch function is given the pid of the sender, and it can + use that to reply by message_send_pid(). See ping_message() for a + simple example. + + @caution Dispatch functions must be able to cope with incoming + messages on an *odd* byte boundary. + + This system doesn't have any inherent size limitations but is not + very efficient for large messages or when messages are sent in very + quick succession. + +*/ + +#include "includes.h" +#include "lib/util/server_id.h" +#include "dbwrap/dbwrap.h" +#include "serverid.h" +#include "messages.h" +#include "lib/util/tevent_unix.h" +#include "lib/background.h" +#include "lib/messaging/messages_dgm.h" +#include "lib/util/iov_buf.h" +#include "lib/util/server_id_db.h" +#include "lib/messaging/messages_dgm_ref.h" +#include "lib/messages_ctdb.h" +#include "lib/messages_ctdb_ref.h" +#include "lib/messages_util.h" +#include "cluster_support.h" +#include "ctdbd_conn.h" +#include "ctdb_srvids.h" + +#ifdef CLUSTER_SUPPORT +#include "ctdb_protocol.h" +#endif + +struct messaging_callback { + struct messaging_callback *prev, *next; + uint32_t msg_type; + void (*fn)(struct messaging_context *msg, void *private_data, + uint32_t msg_type, + struct server_id server_id, DATA_BLOB *data); + void *private_data; +}; + +struct messaging_registered_ev { + struct tevent_context *ev; + struct tevent_immediate *im; + size_t refcount; +}; + +struct messaging_context { + struct server_id id; + struct tevent_context *event_ctx; + struct messaging_callback *callbacks; + + struct messaging_rec *posted_msgs; + + struct messaging_registered_ev *event_contexts; + + struct tevent_req **new_waiters; + size_t num_new_waiters; + + struct tevent_req **waiters; + size_t num_waiters; + + struct server_id_db *names_db; + + TALLOC_CTX *per_process_talloc_ctx; +}; + +static struct messaging_rec *messaging_rec_dup(TALLOC_CTX *mem_ctx, + struct messaging_rec *rec); +static bool messaging_dispatch_classic(struct messaging_context *msg_ctx, + struct messaging_rec *rec); +static bool messaging_dispatch_waiters(struct messaging_context *msg_ctx, + struct tevent_context *ev, + struct messaging_rec *rec); +static void messaging_dispatch_rec(struct messaging_context *msg_ctx, + struct tevent_context *ev, + struct messaging_rec *rec); + +/**************************************************************************** + A useful function for testing the message system. +****************************************************************************/ + +static void ping_message(struct messaging_context *msg_ctx, + void *private_data, + uint32_t msg_type, + struct server_id src, + DATA_BLOB *data) +{ + struct server_id_buf idbuf; + + DEBUG(1, ("INFO: Received PING message from PID %s [%.*s]\n", + server_id_str_buf(src, &idbuf), (int)data->length, + data->data ? (char *)data->data : "")); + + messaging_send(msg_ctx, src, MSG_PONG, data); +} + +struct messaging_rec *messaging_rec_create( + TALLOC_CTX *mem_ctx, struct server_id src, struct server_id dst, + uint32_t msg_type, const struct iovec *iov, int iovlen, + const int *fds, size_t num_fds) +{ + ssize_t buflen; + uint8_t *buf; + struct messaging_rec *result; + + if (num_fds > INT8_MAX) { + return NULL; + } + + buflen = iov_buflen(iov, iovlen); + if (buflen == -1) { + return NULL; + } + buf = talloc_array(mem_ctx, uint8_t, buflen); + if (buf == NULL) { + return NULL; + } + iov_buf(iov, iovlen, buf, buflen); + + { + struct messaging_rec rec; + int64_t fds64[MAX(1, num_fds)]; + size_t i; + + for (i=0; i<num_fds; i++) { + fds64[i] = fds[i]; + } + + rec = (struct messaging_rec) { + .msg_version = MESSAGE_VERSION, .msg_type = msg_type, + .src = src, .dest = dst, + .buf.data = buf, .buf.length = buflen, + .num_fds = num_fds, .fds = fds64, + }; + + result = messaging_rec_dup(mem_ctx, &rec); + } + + TALLOC_FREE(buf); + + return result; +} + +static bool messaging_register_event_context(struct messaging_context *ctx, + struct tevent_context *ev) +{ + size_t i, num_event_contexts; + struct messaging_registered_ev *free_reg = NULL; + struct messaging_registered_ev *tmp; + + num_event_contexts = talloc_array_length(ctx->event_contexts); + + for (i=0; i<num_event_contexts; i++) { + struct messaging_registered_ev *reg = &ctx->event_contexts[i]; + + if (reg->refcount == 0) { + if (reg->ev != NULL) { + abort(); + } + free_reg = reg; + /* + * We continue here and may find another + * free_req, but the important thing is + * that we continue to search for an + * existing registration in the loop. + */ + continue; + } + + if (reg->ev == ev) { + reg->refcount += 1; + return true; + } + } + + if (free_reg == NULL) { + struct tevent_immediate *im = NULL; + + im = tevent_create_immediate(ctx); + if (im == NULL) { + return false; + } + + tmp = talloc_realloc(ctx, ctx->event_contexts, + struct messaging_registered_ev, + num_event_contexts+1); + if (tmp == NULL) { + return false; + } + ctx->event_contexts = tmp; + + free_reg = &ctx->event_contexts[num_event_contexts]; + free_reg->im = talloc_move(ctx->event_contexts, &im); + } + + /* + * free_reg->im might be cached + */ + free_reg->ev = ev; + free_reg->refcount = 1; + + return true; +} + +static bool messaging_deregister_event_context(struct messaging_context *ctx, + struct tevent_context *ev) +{ + size_t i, num_event_contexts; + + num_event_contexts = talloc_array_length(ctx->event_contexts); + + for (i=0; i<num_event_contexts; i++) { + struct messaging_registered_ev *reg = &ctx->event_contexts[i]; + + if (reg->refcount == 0) { + continue; + } + + if (reg->ev == ev) { + reg->refcount -= 1; + + if (reg->refcount == 0) { + /* + * The primary event context + * is never unregistered using + * messaging_deregister_event_context() + * it's only registered using + * messaging_register_event_context(). + */ + SMB_ASSERT(ev != ctx->event_ctx); + SMB_ASSERT(reg->ev != ctx->event_ctx); + + /* + * Not strictly necessary, just + * paranoia + */ + reg->ev = NULL; + + /* + * Do not talloc_free(reg->im), + * recycle immediates events. + * + * We just invalidate it using + * the primary event context, + * which is never unregistered. + */ + tevent_schedule_immediate(reg->im, + ctx->event_ctx, + NULL, NULL); + } + return true; + } + } + return false; +} + +static void messaging_post_main_event_context(struct tevent_context *ev, + struct tevent_immediate *im, + void *private_data) +{ + struct messaging_context *ctx = talloc_get_type_abort( + private_data, struct messaging_context); + + while (ctx->posted_msgs != NULL) { + struct messaging_rec *rec = ctx->posted_msgs; + bool consumed; + + DLIST_REMOVE(ctx->posted_msgs, rec); + + consumed = messaging_dispatch_classic(ctx, rec); + if (!consumed) { + consumed = messaging_dispatch_waiters( + ctx, ctx->event_ctx, rec); + } + + if (!consumed) { + uint8_t i; + + for (i=0; i<rec->num_fds; i++) { + close(rec->fds[i]); + } + } + + TALLOC_FREE(rec); + } +} + +static void messaging_post_sub_event_context(struct tevent_context *ev, + struct tevent_immediate *im, + void *private_data) +{ + struct messaging_context *ctx = talloc_get_type_abort( + private_data, struct messaging_context); + struct messaging_rec *rec, *next; + + for (rec = ctx->posted_msgs; rec != NULL; rec = next) { + bool consumed; + + next = rec->next; + + consumed = messaging_dispatch_waiters(ctx, ev, rec); + if (consumed) { + DLIST_REMOVE(ctx->posted_msgs, rec); + TALLOC_FREE(rec); + } + } +} + +static bool messaging_alert_event_contexts(struct messaging_context *ctx) +{ + size_t i, num_event_contexts; + + num_event_contexts = talloc_array_length(ctx->event_contexts); + + for (i=0; i<num_event_contexts; i++) { + struct messaging_registered_ev *reg = &ctx->event_contexts[i]; + + if (reg->refcount == 0) { + continue; + } + + /* + * We depend on schedule_immediate to work + * multiple times. Might be a bit inefficient, + * but this needs to be proven in tests. The + * alternatively would be to track whether the + * immediate has already been scheduled. For + * now, avoid that complexity here. + */ + + if (reg->ev == ctx->event_ctx) { + tevent_schedule_immediate( + reg->im, reg->ev, + messaging_post_main_event_context, + ctx); + } else { + tevent_schedule_immediate( + reg->im, reg->ev, + messaging_post_sub_event_context, + ctx); + } + + } + return true; +} + +static void messaging_recv_cb(struct tevent_context *ev, + const uint8_t *msg, size_t msg_len, + int *fds, size_t num_fds, + void *private_data) +{ + struct messaging_context *msg_ctx = talloc_get_type_abort( + private_data, struct messaging_context); + struct server_id_buf idbuf; + struct messaging_rec rec; + int64_t fds64[MAX(1, MIN(num_fds, INT8_MAX))]; + size_t i; + + if (msg_len < MESSAGE_HDR_LENGTH) { + DBG_WARNING("message too short: %zu\n", msg_len); + return; + } + + if (num_fds > INT8_MAX) { + DBG_WARNING("too many fds: %zu\n", num_fds); + return; + } + + for (i=0; i < num_fds; i++) { + fds64[i] = fds[i]; + } + + rec = (struct messaging_rec) { + .msg_version = MESSAGE_VERSION, + .buf.data = discard_const_p(uint8_t, msg) + MESSAGE_HDR_LENGTH, + .buf.length = msg_len - MESSAGE_HDR_LENGTH, + .num_fds = num_fds, + .fds = fds64, + }; + + message_hdr_get(&rec.msg_type, &rec.src, &rec.dest, msg); + + DBG_DEBUG("Received message 0x%x len %zu (num_fds:%zu) from %s\n", + (unsigned)rec.msg_type, rec.buf.length, num_fds, + server_id_str_buf(rec.src, &idbuf)); + + if (server_id_same_process(&rec.src, &msg_ctx->id)) { + DBG_DEBUG("Ignoring self-send\n"); + return; + } + + messaging_dispatch_rec(msg_ctx, ev, &rec); + + for (i=0; i<num_fds; i++) { + fds[i] = fds64[i]; + } +} + +static int messaging_context_destructor(struct messaging_context *ctx) +{ + size_t i; + + for (i=0; i<ctx->num_new_waiters; i++) { + if (ctx->new_waiters[i] != NULL) { + tevent_req_set_cleanup_fn(ctx->new_waiters[i], NULL); + ctx->new_waiters[i] = NULL; + } + } + for (i=0; i<ctx->num_waiters; i++) { + if (ctx->waiters[i] != NULL) { + tevent_req_set_cleanup_fn(ctx->waiters[i], NULL); + ctx->waiters[i] = NULL; + } + } + + /* + * The immediates from messaging_alert_event_contexts + * reference "ctx". Don't let them outlive the + * messaging_context we're destroying here. + */ + TALLOC_FREE(ctx->event_contexts); + + return 0; +} + +static const char *private_path(const char *name) +{ + return talloc_asprintf(talloc_tos(), "%s/%s", lp_private_dir(), name); +} + +static NTSTATUS messaging_init_internal(TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct messaging_context **pmsg_ctx) +{ + TALLOC_CTX *frame; + struct messaging_context *ctx; + NTSTATUS status; + int ret; + const char *lck_path; + const char *priv_path; + void *ref; + bool ok; + + /* + * sec_init() *must* be called before any other + * functions that use sec_XXX(). e.g. sec_initial_uid(). + */ + + sec_init(); + + lck_path = lock_path(talloc_tos(), "msg.lock"); + if (lck_path == NULL) { + return NT_STATUS_NO_MEMORY; + } + + ok = directory_create_or_exist_strict(lck_path, + sec_initial_uid(), + 0755); + if (!ok) { + DBG_DEBUG("Could not create lock directory: %s\n", + strerror(errno)); + return NT_STATUS_ACCESS_DENIED; + } + + priv_path = private_path("msg.sock"); + if (priv_path == NULL) { + return NT_STATUS_NO_MEMORY; + } + + ok = directory_create_or_exist_strict(priv_path, sec_initial_uid(), + 0700); + if (!ok) { + DBG_DEBUG("Could not create msg directory: %s\n", + strerror(errno)); + return NT_STATUS_ACCESS_DENIED; + } + + frame = talloc_stackframe(); + if (frame == NULL) { + return NT_STATUS_NO_MEMORY; + } + + ctx = talloc_zero(frame, struct messaging_context); + if (ctx == NULL) { + status = NT_STATUS_NO_MEMORY; + goto done; + } + + ctx->id = (struct server_id) { + .pid = tevent_cached_getpid(), .vnn = NONCLUSTER_VNN + }; + + ctx->event_ctx = ev; + + ctx->per_process_talloc_ctx = talloc_new(ctx); + if (ctx->per_process_talloc_ctx == NULL) { + status = NT_STATUS_NO_MEMORY; + goto done; + } + + ok = messaging_register_event_context(ctx, ev); + if (!ok) { + status = NT_STATUS_NO_MEMORY; + goto done; + } + + ref = messaging_dgm_ref( + ctx->per_process_talloc_ctx, + ctx->event_ctx, + &ctx->id.unique_id, + priv_path, + lck_path, + messaging_recv_cb, + ctx, + &ret); + if (ref == NULL) { + DEBUG(2, ("messaging_dgm_ref failed: %s\n", strerror(ret))); + status = map_nt_error_from_unix(ret); + goto done; + } + talloc_set_destructor(ctx, messaging_context_destructor); + +#ifdef CLUSTER_SUPPORT + if (lp_clustering()) { + ref = messaging_ctdb_ref( + ctx->per_process_talloc_ctx, + ctx->event_ctx, + lp_ctdbd_socket(), + lp_ctdb_timeout(), + ctx->id.unique_id, + messaging_recv_cb, + ctx, + &ret); + if (ref == NULL) { + DBG_NOTICE("messaging_ctdb_ref failed: %s\n", + strerror(ret)); + status = map_nt_error_from_unix(ret); + goto done; + } + } +#endif + + ctx->id.vnn = get_my_vnn(); + + ctx->names_db = server_id_db_init(ctx, + ctx->id, + lp_lock_directory(), + 0, + TDB_INCOMPATIBLE_HASH|TDB_CLEAR_IF_FIRST); + if (ctx->names_db == NULL) { + DBG_DEBUG("server_id_db_init failed\n"); + status = NT_STATUS_NO_MEMORY; + goto done; + } + + messaging_register(ctx, NULL, MSG_PING, ping_message); + + /* Register some debugging related messages */ + + register_msg_pool_usage(ctx->per_process_talloc_ctx, ctx); + register_dmalloc_msgs(ctx); + debug_register_msgs(ctx); + + { + struct server_id_buf tmp; + DBG_DEBUG("my id: %s\n", server_id_str_buf(ctx->id, &tmp)); + } + + *pmsg_ctx = talloc_steal(mem_ctx, ctx); + + status = NT_STATUS_OK; +done: + TALLOC_FREE(frame); + + return status; +} + +struct messaging_context *messaging_init(TALLOC_CTX *mem_ctx, + struct tevent_context *ev) +{ + struct messaging_context *ctx = NULL; + NTSTATUS status; + + status = messaging_init_internal(mem_ctx, + ev, + &ctx); + if (!NT_STATUS_IS_OK(status)) { + return NULL; + } + + return ctx; +} + +struct server_id messaging_server_id(const struct messaging_context *msg_ctx) +{ + return msg_ctx->id; +} + +/* + * re-init after a fork + */ +NTSTATUS messaging_reinit(struct messaging_context *msg_ctx) +{ + int ret; + char *lck_path; + void *ref; + + TALLOC_FREE(msg_ctx->per_process_talloc_ctx); + + msg_ctx->per_process_talloc_ctx = talloc_new(msg_ctx); + if (msg_ctx->per_process_talloc_ctx == NULL) { + return NT_STATUS_NO_MEMORY; + } + + msg_ctx->id = (struct server_id) { + .pid = tevent_cached_getpid(), .vnn = msg_ctx->id.vnn + }; + + lck_path = lock_path(talloc_tos(), "msg.lock"); + if (lck_path == NULL) { + return NT_STATUS_NO_MEMORY; + } + + ref = messaging_dgm_ref( + msg_ctx->per_process_talloc_ctx, + msg_ctx->event_ctx, + &msg_ctx->id.unique_id, + private_path("msg.sock"), + lck_path, + messaging_recv_cb, + msg_ctx, + &ret); + + if (ref == NULL) { + DEBUG(2, ("messaging_dgm_ref failed: %s\n", strerror(ret))); + return map_nt_error_from_unix(ret); + } + + if (lp_clustering()) { + ref = messaging_ctdb_ref( + msg_ctx->per_process_talloc_ctx, + msg_ctx->event_ctx, + lp_ctdbd_socket(), + lp_ctdb_timeout(), + msg_ctx->id.unique_id, + messaging_recv_cb, + msg_ctx, + &ret); + if (ref == NULL) { + DBG_NOTICE("messaging_ctdb_ref failed: %s\n", + strerror(ret)); + return map_nt_error_from_unix(ret); + } + } + + server_id_db_reinit(msg_ctx->names_db, msg_ctx->id); + register_msg_pool_usage(msg_ctx->per_process_talloc_ctx, msg_ctx); + + return NT_STATUS_OK; +} + + +/* + * Register a dispatch function for a particular message type. Allow multiple + * registrants +*/ +NTSTATUS messaging_register(struct messaging_context *msg_ctx, + void *private_data, + uint32_t msg_type, + void (*fn)(struct messaging_context *msg, + void *private_data, + uint32_t msg_type, + struct server_id server_id, + DATA_BLOB *data)) +{ + struct messaging_callback *cb; + + DEBUG(5, ("Registering messaging pointer for type %u - " + "private_data=%p\n", + (unsigned)msg_type, private_data)); + + /* + * Only one callback per type + */ + + for (cb = msg_ctx->callbacks; cb != NULL; cb = cb->next) { + /* we allow a second registration of the same message + type if it has a different private pointer. This is + needed in, for example, the internal notify code, + which creates a new notify context for each tree + connect, and expects to receive messages to each of + them. */ + if (cb->msg_type == msg_type && private_data == cb->private_data) { + DEBUG(5,("Overriding messaging pointer for type %u - private_data=%p\n", + (unsigned)msg_type, private_data)); + cb->fn = fn; + cb->private_data = private_data; + return NT_STATUS_OK; + } + } + + if (!(cb = talloc(msg_ctx, struct messaging_callback))) { + return NT_STATUS_NO_MEMORY; + } + + cb->msg_type = msg_type; + cb->fn = fn; + cb->private_data = private_data; + + DLIST_ADD(msg_ctx->callbacks, cb); + return NT_STATUS_OK; +} + +/* + De-register the function for a particular message type. +*/ +void messaging_deregister(struct messaging_context *ctx, uint32_t msg_type, + void *private_data) +{ + struct messaging_callback *cb, *next; + + for (cb = ctx->callbacks; cb; cb = next) { + next = cb->next; + if ((cb->msg_type == msg_type) + && (cb->private_data == private_data)) { + DEBUG(5,("Deregistering messaging pointer for type %u - private_data=%p\n", + (unsigned)msg_type, private_data)); + DLIST_REMOVE(ctx->callbacks, cb); + TALLOC_FREE(cb); + } + } +} + +/* + Send a message to a particular server +*/ +NTSTATUS messaging_send(struct messaging_context *msg_ctx, + struct server_id server, uint32_t msg_type, + const DATA_BLOB *data) +{ + struct iovec iov = {0}; + + if (data != NULL) { + iov.iov_base = data->data; + iov.iov_len = data->length; + }; + + return messaging_send_iov(msg_ctx, server, msg_type, &iov, 1, NULL, 0); +} + +NTSTATUS messaging_send_buf(struct messaging_context *msg_ctx, + struct server_id server, uint32_t msg_type, + const uint8_t *buf, size_t len) +{ + DATA_BLOB blob = data_blob_const(buf, len); + return messaging_send(msg_ctx, server, msg_type, &blob); +} + +static int messaging_post_self(struct messaging_context *msg_ctx, + struct server_id src, struct server_id dst, + uint32_t msg_type, + const struct iovec *iov, int iovlen, + const int *fds, size_t num_fds) +{ + struct messaging_rec *rec; + bool ok; + + rec = messaging_rec_create( + msg_ctx, src, dst, msg_type, iov, iovlen, fds, num_fds); + if (rec == NULL) { + return ENOMEM; + } + + ok = messaging_alert_event_contexts(msg_ctx); + if (!ok) { + TALLOC_FREE(rec); + return ENOMEM; + } + + DLIST_ADD_END(msg_ctx->posted_msgs, rec); + + return 0; +} + +int messaging_send_iov_from(struct messaging_context *msg_ctx, + struct server_id src, struct server_id dst, + uint32_t msg_type, + const struct iovec *iov, int iovlen, + const int *fds, size_t num_fds) +{ + int ret; + uint8_t hdr[MESSAGE_HDR_LENGTH]; + struct iovec iov2[iovlen+1]; + + if (server_id_is_disconnected(&dst)) { + return EINVAL; + } + + if (num_fds > INT8_MAX) { + return EINVAL; + } + + if (server_id_equal(&dst, &msg_ctx->id)) { + ret = messaging_post_self(msg_ctx, src, dst, msg_type, + iov, iovlen, fds, num_fds); + return ret; + } + + message_hdr_put(hdr, msg_type, src, dst); + iov2[0] = (struct iovec){ .iov_base = hdr, .iov_len = sizeof(hdr) }; + memcpy(&iov2[1], iov, iovlen * sizeof(*iov)); + + if (dst.vnn != msg_ctx->id.vnn) { + if (num_fds > 0) { + return ENOSYS; + } + + ret = messaging_ctdb_send(dst.vnn, dst.pid, iov2, iovlen+1); + return ret; + } + + ret = messaging_dgm_send(dst.pid, iov2, iovlen+1, fds, num_fds); + + if (ret == EACCES) { + become_root(); + ret = messaging_dgm_send(dst.pid, iov2, iovlen+1, + fds, num_fds); + unbecome_root(); + } + + if (ret == ECONNREFUSED) { + /* + * Linux returns this when a socket exists in the file + * system without a listening process. This is not + * documented in susv4 or the linux manpages, but it's + * easily testable. For the higher levels this is the + * same as "destination does not exist" + */ + ret = ENOENT; + } + + return ret; +} + +NTSTATUS messaging_send_iov(struct messaging_context *msg_ctx, + struct server_id dst, uint32_t msg_type, + const struct iovec *iov, int iovlen, + const int *fds, size_t num_fds) +{ + int ret; + + ret = messaging_send_iov_from(msg_ctx, msg_ctx->id, dst, msg_type, + iov, iovlen, fds, num_fds); + if (ret != 0) { + return map_nt_error_from_unix(ret); + } + return NT_STATUS_OK; +} + +struct send_all_state { + struct messaging_context *msg_ctx; + int msg_type; + const void *buf; + size_t len; +}; + +static int send_all_fn(pid_t pid, void *private_data) +{ + struct send_all_state *state = private_data; + NTSTATUS status; + + if (pid == tevent_cached_getpid()) { + DBG_DEBUG("Skip ourselves in messaging_send_all\n"); + return 0; + } + + status = messaging_send_buf(state->msg_ctx, pid_to_procid(pid), + state->msg_type, state->buf, state->len); + if (!NT_STATUS_IS_OK(status)) { + DBG_NOTICE("messaging_send_buf to %ju failed: %s\n", + (uintmax_t)pid, nt_errstr(status)); + } + + return 0; +} + +void messaging_send_all(struct messaging_context *msg_ctx, + int msg_type, const void *buf, size_t len) +{ + struct send_all_state state = { + .msg_ctx = msg_ctx, .msg_type = msg_type, + .buf = buf, .len = len + }; + int ret; + +#ifdef CLUSTER_SUPPORT + if (lp_clustering()) { + struct ctdbd_connection *conn = messaging_ctdb_connection(); + uint8_t msghdr[MESSAGE_HDR_LENGTH]; + struct iovec iov[] = { + { .iov_base = msghdr, + .iov_len = sizeof(msghdr) }, + { .iov_base = discard_const_p(void, buf), + .iov_len = len } + }; + + message_hdr_put(msghdr, msg_type, messaging_server_id(msg_ctx), + (struct server_id) {0}); + + ret = ctdbd_messaging_send_iov( + conn, CTDB_BROADCAST_CONNECTED, + CTDB_SRVID_SAMBA_PROCESS, + iov, ARRAY_SIZE(iov)); + if (ret != 0) { + DBG_WARNING("ctdbd_messaging_send_iov failed: %s\n", + strerror(ret)); + } + + return; + } +#endif + + ret = messaging_dgm_forall(send_all_fn, &state); + if (ret != 0) { + DBG_WARNING("messaging_dgm_forall failed: %s\n", + strerror(ret)); + } +} + +static struct messaging_rec *messaging_rec_dup(TALLOC_CTX *mem_ctx, + struct messaging_rec *rec) +{ + struct messaging_rec *result; + size_t fds_size = sizeof(int64_t) * rec->num_fds; + size_t payload_len; + + payload_len = rec->buf.length + fds_size; + if (payload_len < rec->buf.length) { + /* overflow */ + return NULL; + } + + result = talloc_pooled_object(mem_ctx, struct messaging_rec, 2, + payload_len); + if (result == NULL) { + return NULL; + } + *result = *rec; + + /* Doesn't fail, see talloc_pooled_object */ + + result->buf.data = talloc_memdup(result, rec->buf.data, + rec->buf.length); + + result->fds = NULL; + if (result->num_fds > 0) { + size_t i; + + result->fds = talloc_memdup(result, rec->fds, fds_size); + + for (i=0; i<rec->num_fds; i++) { + /* + * fd's can only exist once + */ + rec->fds[i] = -1; + } + } + + return result; +} + +struct messaging_filtered_read_state { + struct tevent_context *ev; + struct messaging_context *msg_ctx; + struct messaging_dgm_fde *fde; + struct messaging_ctdb_fde *cluster_fde; + + bool (*filter)(struct messaging_rec *rec, void *private_data); + void *private_data; + + struct messaging_rec *rec; +}; + +static void messaging_filtered_read_cleanup(struct tevent_req *req, + enum tevent_req_state req_state); + +struct tevent_req *messaging_filtered_read_send( + TALLOC_CTX *mem_ctx, struct tevent_context *ev, + struct messaging_context *msg_ctx, + bool (*filter)(struct messaging_rec *rec, void *private_data), + void *private_data) +{ + struct tevent_req *req; + struct messaging_filtered_read_state *state; + size_t new_waiters_len; + bool ok; + + req = tevent_req_create(mem_ctx, &state, + struct messaging_filtered_read_state); + if (req == NULL) { + return NULL; + } + state->ev = ev; + state->msg_ctx = msg_ctx; + state->filter = filter; + state->private_data = private_data; + + /* + * We have to defer the callback here, as we might be called from + * within a different tevent_context than state->ev + */ + tevent_req_defer_callback(req, state->ev); + + state->fde = messaging_dgm_register_tevent_context(state, ev); + if (tevent_req_nomem(state->fde, req)) { + return tevent_req_post(req, ev); + } + + if (lp_clustering()) { + state->cluster_fde = + messaging_ctdb_register_tevent_context(state, ev); + if (tevent_req_nomem(state->cluster_fde, req)) { + return tevent_req_post(req, ev); + } + } + + /* + * We add ourselves to the "new_waiters" array, not the "waiters" + * array. If we are called from within messaging_read_done, + * messaging_dispatch_rec will be in an active for-loop on + * "waiters". We must be careful not to mess with this array, because + * it could mean that a single event is being delivered twice. + */ + + new_waiters_len = talloc_array_length(msg_ctx->new_waiters); + + if (new_waiters_len == msg_ctx->num_new_waiters) { + struct tevent_req **tmp; + + tmp = talloc_realloc(msg_ctx, msg_ctx->new_waiters, + struct tevent_req *, new_waiters_len+1); + if (tevent_req_nomem(tmp, req)) { + return tevent_req_post(req, ev); + } + msg_ctx->new_waiters = tmp; + } + + msg_ctx->new_waiters[msg_ctx->num_new_waiters] = req; + msg_ctx->num_new_waiters += 1; + tevent_req_set_cleanup_fn(req, messaging_filtered_read_cleanup); + + ok = messaging_register_event_context(msg_ctx, ev); + if (!ok) { + tevent_req_oom(req); + return tevent_req_post(req, ev); + } + + return req; +} + +static void messaging_filtered_read_cleanup(struct tevent_req *req, + enum tevent_req_state req_state) +{ + struct messaging_filtered_read_state *state = tevent_req_data( + req, struct messaging_filtered_read_state); + struct messaging_context *msg_ctx = state->msg_ctx; + size_t i; + bool ok; + + tevent_req_set_cleanup_fn(req, NULL); + + TALLOC_FREE(state->fde); + TALLOC_FREE(state->cluster_fde); + + ok = messaging_deregister_event_context(msg_ctx, state->ev); + if (!ok) { + abort(); + } + + /* + * Just set the [new_]waiters entry to NULL, be careful not to mess + * with the other "waiters" array contents. We are often called from + * within "messaging_dispatch_rec", which loops over + * "waiters". Messing with the "waiters" array will mess up that + * for-loop. + */ + + for (i=0; i<msg_ctx->num_waiters; i++) { + if (msg_ctx->waiters[i] == req) { + msg_ctx->waiters[i] = NULL; + return; + } + } + + for (i=0; i<msg_ctx->num_new_waiters; i++) { + if (msg_ctx->new_waiters[i] == req) { + msg_ctx->new_waiters[i] = NULL; + return; + } + } +} + +static void messaging_filtered_read_done(struct tevent_req *req, + struct messaging_rec *rec) +{ + struct messaging_filtered_read_state *state = tevent_req_data( + req, struct messaging_filtered_read_state); + + state->rec = messaging_rec_dup(state, rec); + if (tevent_req_nomem(state->rec, req)) { + return; + } + tevent_req_done(req); +} + +int messaging_filtered_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, + struct messaging_rec **presult) +{ + struct messaging_filtered_read_state *state = tevent_req_data( + req, struct messaging_filtered_read_state); + int err; + + if (tevent_req_is_unix_error(req, &err)) { + tevent_req_received(req); + return err; + } + if (presult != NULL) { + *presult = talloc_move(mem_ctx, &state->rec); + } + tevent_req_received(req); + return 0; +} + +struct messaging_read_state { + uint32_t msg_type; + struct messaging_rec *rec; +}; + +static bool messaging_read_filter(struct messaging_rec *rec, + void *private_data); +static void messaging_read_done(struct tevent_req *subreq); + +struct tevent_req *messaging_read_send(TALLOC_CTX *mem_ctx, + struct tevent_context *ev, + struct messaging_context *msg, + uint32_t msg_type) +{ + struct tevent_req *req, *subreq; + struct messaging_read_state *state; + + req = tevent_req_create(mem_ctx, &state, + struct messaging_read_state); + if (req == NULL) { + return NULL; + } + state->msg_type = msg_type; + + subreq = messaging_filtered_read_send(state, ev, msg, + messaging_read_filter, state); + if (tevent_req_nomem(subreq, req)) { + return tevent_req_post(req, ev); + } + tevent_req_set_callback(subreq, messaging_read_done, req); + return req; +} + +static bool messaging_read_filter(struct messaging_rec *rec, + void *private_data) +{ + struct messaging_read_state *state = talloc_get_type_abort( + private_data, struct messaging_read_state); + + if (rec->num_fds != 0) { + return false; + } + + return rec->msg_type == state->msg_type; +} + +static void messaging_read_done(struct tevent_req *subreq) +{ + struct tevent_req *req = tevent_req_callback_data( + subreq, struct tevent_req); + struct messaging_read_state *state = tevent_req_data( + req, struct messaging_read_state); + int ret; + + ret = messaging_filtered_read_recv(subreq, state, &state->rec); + TALLOC_FREE(subreq); + if (tevent_req_error(req, ret)) { + return; + } + tevent_req_done(req); +} + +int messaging_read_recv(struct tevent_req *req, TALLOC_CTX *mem_ctx, + struct messaging_rec **presult) +{ + struct messaging_read_state *state = tevent_req_data( + req, struct messaging_read_state); + int err; + + if (tevent_req_is_unix_error(req, &err)) { + return err; + } + if (presult != NULL) { + *presult = talloc_move(mem_ctx, &state->rec); + } + return 0; +} + +static bool messaging_append_new_waiters(struct messaging_context *msg_ctx) +{ + if (msg_ctx->num_new_waiters == 0) { + return true; + } + + if (talloc_array_length(msg_ctx->waiters) < + (msg_ctx->num_waiters + msg_ctx->num_new_waiters)) { + struct tevent_req **tmp; + tmp = talloc_realloc( + msg_ctx, msg_ctx->waiters, struct tevent_req *, + msg_ctx->num_waiters + msg_ctx->num_new_waiters); + if (tmp == NULL) { + DEBUG(1, ("%s: talloc failed\n", __func__)); + return false; + } + msg_ctx->waiters = tmp; + } + + memcpy(&msg_ctx->waiters[msg_ctx->num_waiters], msg_ctx->new_waiters, + sizeof(struct tevent_req *) * msg_ctx->num_new_waiters); + + msg_ctx->num_waiters += msg_ctx->num_new_waiters; + msg_ctx->num_new_waiters = 0; + + return true; +} + +static bool messaging_dispatch_classic(struct messaging_context *msg_ctx, + struct messaging_rec *rec) +{ + struct messaging_callback *cb, *next; + + for (cb = msg_ctx->callbacks; cb != NULL; cb = next) { + size_t j; + + next = cb->next; + if (cb->msg_type != rec->msg_type) { + continue; + } + + /* + * the old style callbacks don't support fd passing + */ + for (j=0; j < rec->num_fds; j++) { + int fd = rec->fds[j]; + close(fd); + } + rec->num_fds = 0; + rec->fds = NULL; + + cb->fn(msg_ctx, cb->private_data, rec->msg_type, + rec->src, &rec->buf); + + return true; + } + + return false; +} + +static bool messaging_dispatch_waiters(struct messaging_context *msg_ctx, + struct tevent_context *ev, + struct messaging_rec *rec) +{ + size_t i; + + if (!messaging_append_new_waiters(msg_ctx)) { + return false; + } + + i = 0; + while (i < msg_ctx->num_waiters) { + struct tevent_req *req; + struct messaging_filtered_read_state *state; + + req = msg_ctx->waiters[i]; + if (req == NULL) { + /* + * This got cleaned up. In the meantime, + * move everything down one. We need + * to keep the order of waiters, as + * other code may depend on this. + */ + ARRAY_DEL_ELEMENT( + msg_ctx->waiters, i, msg_ctx->num_waiters); + msg_ctx->num_waiters -= 1; + continue; + } + + state = tevent_req_data( + req, struct messaging_filtered_read_state); + if ((ev == state->ev) && + state->filter(rec, state->private_data)) { + messaging_filtered_read_done(req, rec); + return true; + } + + i += 1; + } + + return false; +} + +/* + Dispatch one messaging_rec +*/ +static void messaging_dispatch_rec(struct messaging_context *msg_ctx, + struct tevent_context *ev, + struct messaging_rec *rec) +{ + bool consumed; + size_t i; + + if (ev == msg_ctx->event_ctx) { + consumed = messaging_dispatch_classic(msg_ctx, rec); + if (consumed) { + return; + } + } + + consumed = messaging_dispatch_waiters(msg_ctx, ev, rec); + if (consumed) { + return; + } + + if (ev != msg_ctx->event_ctx) { + struct iovec iov; + int fds[MAX(1, rec->num_fds)]; + int ret; + + /* + * We've been listening on a nested event + * context. Messages need to be handled in the main + * event context, so post to ourselves + */ + + iov.iov_base = rec->buf.data; + iov.iov_len = rec->buf.length; + + for (i=0; i<rec->num_fds; i++) { + fds[i] = rec->fds[i]; + } + + ret = messaging_post_self( + msg_ctx, rec->src, rec->dest, rec->msg_type, + &iov, 1, fds, rec->num_fds); + if (ret == 0) { + return; + } + } +} + +static int mess_parent_dgm_cleanup(void *private_data); +static void mess_parent_dgm_cleanup_done(struct tevent_req *req); + +bool messaging_parent_dgm_cleanup_init(struct messaging_context *msg) +{ + struct tevent_req *req; + + req = background_job_send( + msg, msg->event_ctx, msg, NULL, 0, + lp_parm_int(-1, "messaging", "messaging dgm cleanup interval", + 60*15), + mess_parent_dgm_cleanup, msg); + if (req == NULL) { + DBG_WARNING("background_job_send failed\n"); + return false; + } + tevent_req_set_callback(req, mess_parent_dgm_cleanup_done, msg); + return true; +} + +static int mess_parent_dgm_cleanup(void *private_data) +{ + int ret; + + ret = messaging_dgm_wipe(); + DEBUG(10, ("messaging_dgm_wipe returned %s\n", + ret ? strerror(ret) : "ok")); + return lp_parm_int(-1, "messaging", "messaging dgm cleanup interval", + 60*15); +} + +static void mess_parent_dgm_cleanup_done(struct tevent_req *req) +{ + struct messaging_context *msg = tevent_req_callback_data( + req, struct messaging_context); + NTSTATUS status; + + status = background_job_recv(req); + TALLOC_FREE(req); + DEBUG(1, ("messaging dgm cleanup job ended with %s\n", + nt_errstr(status))); + + req = background_job_send( + msg, msg->event_ctx, msg, NULL, 0, + lp_parm_int(-1, "messaging", "messaging dgm cleanup interval", + 60*15), + mess_parent_dgm_cleanup, msg); + if (req == NULL) { + DEBUG(1, ("background_job_send failed\n")); + return; + } + tevent_req_set_callback(req, mess_parent_dgm_cleanup_done, msg); +} + +int messaging_cleanup(struct messaging_context *msg_ctx, pid_t pid) +{ + int ret; + + if (pid == 0) { + ret = messaging_dgm_wipe(); + } else { + ret = messaging_dgm_cleanup(pid); + } + + return ret; +} + +struct tevent_context *messaging_tevent_context( + struct messaging_context *msg_ctx) +{ + return msg_ctx->event_ctx; +} + +struct server_id_db *messaging_names_db(struct messaging_context *msg_ctx) +{ + return msg_ctx->names_db; +} + +/** @} **/ |