diff options
Diffstat (limited to 'lib/tevent/tevent_port.c')
| -rw-r--r-- | lib/tevent/tevent_port.c | 804 |
1 files changed, 804 insertions, 0 deletions
diff --git a/lib/tevent/tevent_port.c b/lib/tevent/tevent_port.c new file mode 100644 index 0000000..ccb65a7 --- /dev/null +++ b/lib/tevent/tevent_port.c @@ -0,0 +1,804 @@ +/* + Unix SMB/CIFS implementation. + + Main select loop and event handling - Solaris port implementation. + Losely based on the Linux epoll backend. + + Copyright (C) Jeremy Allison 2013 + + ** NOTE! The following LGPL license applies to the tevent + ** library. This does NOT imply that all of Samba is released + ** under the LGPL + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 3 of the License, or (at your option) any later version. + + This library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, see <http://www.gnu.org/licenses/>. +*/ + +#include "replace.h" +#include "system/filesys.h" +#include "system/select.h" +#include "tevent.h" +#include "tevent_internal.h" +#include "tevent_util.h" + +struct port_associate_vals { + struct port_associate_vals *prev, *next; + struct port_event_context *port_ev; + int events; + struct tevent_fd *fde; + bool associated_event; +}; + +struct port_event_context { + /* a pointer back to the generic event_context */ + struct tevent_context *ev; + + /* This is the handle from port_create */ + int port_fd; + + pid_t pid; + + /* List of associations. */ + struct port_associate_vals *po_vals; +}; + +#define PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION (1<<0) +#define PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR (1<<1) +#define PORT_ADDITIONAL_FD_FLAG_GOT_ERROR (1<<2) +#define PORT_ADDITIONAL_FD_FLAG_HAS_MPX (1<<3) + +/* + Map from TEVENT_FD_* to POLLIN/POLLOUT +*/ +static int port_map_flags(uint16_t flags) +{ + int ret = 0; + if (flags & TEVENT_FD_READ) ret |= (POLLIN | POLLERR | POLLHUP); + if (flags & TEVENT_FD_WRITE) ret |= (POLLOUT | POLLERR | POLLHUP); + return ret; +} + +/* + Free the port fd +*/ +static int port_ctx_destructor(struct port_event_context *port_ev) +{ + close(port_ev->port_fd); + port_ev->port_fd = -1; + return 0; +} + +/* + Init the port fd +*/ +static int port_init_ctx(struct port_event_context *port_ev) +{ + port_ev->port_fd = port_create(); + if (port_ev->port_fd == -1) { + tevent_debug(port_ev->ev, TEVENT_DEBUG_FATAL, + "Failed to create port handle.\n"); + return -1; + } + + if (!ev_set_close_on_exec(port_ev->port_fd)) { + tevent_debug(port_ev->ev, TEVENT_DEBUG_WARNING, + "Failed to set close-on-exec, file descriptor may be leaked to children.\n"); + } + + port_ev->pid = tevent_cached_getpid(); + talloc_set_destructor(port_ev, port_ctx_destructor); + + return 0; +} + +/* + Functions to manage the lower level cache of associated events on the port_fd. +*/ + +static int port_associate_vals_destructor(struct port_associate_vals *val) +{ + DLIST_REMOVE(val->port_ev->po_vals, val); + memset(val, '\0', sizeof(struct port_associate_vals)); + return 0; +} + +/* + * TODO: As the port_association is per-fde, it should be possible to store it + * directly in fde->additional_data, alongside any multiplexed-fde. That way the + * lookup on store and delete would be avoided, and associate_all_events() could + * walk the ev->fd_events list. + */ +static bool store_port_association(struct port_event_context *port_ev, + struct tevent_fd *fde, + int events) +{ + struct port_associate_vals *val; + + for (val = port_ev->po_vals; val; val = val->next) { + if (val->fde->fd == fde->fd) { + /* Association already attached to fd. */ + if (val->events != events) { + val->events = events; + val->associated_event = false; + } + return true; + } + } + + val = talloc_zero(port_ev, struct port_associate_vals); + if (val == NULL) { + return false; + } + + val->port_ev = port_ev; + val->fde = fde; + val->events = events; + val->associated_event = false; + + DLIST_ADD(port_ev->po_vals, val); + talloc_set_destructor(val, port_associate_vals_destructor); + + return true; +} + +static void delete_port_association(struct port_event_context *port_ev, + struct tevent_fd *fde) +{ + struct port_associate_vals *val; + + for (val = port_ev->po_vals; val; val = val->next) { + if (val->fde == fde) { + if (val->associated_event) { + (void)port_dissociate(port_ev->port_fd, + PORT_SOURCE_FD, + fde->fd); + } + talloc_free(val); + return; + } + } +} + +static int associate_all_events(struct port_event_context *port_ev) +{ + struct port_associate_vals *val; + + for (val = port_ev->po_vals; val; val = val->next) { + int ret; + if (val->associated_event) { + continue; + } + ret = port_associate(port_ev->port_fd, + PORT_SOURCE_FD, + (uintptr_t)val->fde->fd, + val->events, + (void *)val); + if (ret != 0) { + return -1; + } + val->associated_event = true; + } + return 0; +} + +static int port_update_event(struct port_event_context *port_ev, struct tevent_fd *fde); + +/* + Reopen the port handle when our pid changes. + */ +static int port_check_reopen(struct port_event_context *port_ev) +{ + struct tevent_fd *fde; + pid_t pid = tevent_cached_getpid(); + + if (port_ev->pid == pid) { + return 0; + } + + close(port_ev->port_fd); + port_ev->port_fd = port_create(); + if (port_ev->port_fd == -1) { + tevent_debug(port_ev->ev, TEVENT_DEBUG_FATAL, + "port_create() failed"); + return -1; + } + + if (!ev_set_close_on_exec(port_ev->port_fd)) { + tevent_debug(port_ev->ev, TEVENT_DEBUG_WARNING, + "Failed to set close-on-exec, file descriptor may be leaked to children.\n"); + } + + port_ev->pid = pid; + for (fde=port_ev->ev->fd_events;fde;fde=fde->next) { + fde->additional_flags &= PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + if (port_update_event(port_ev, fde) != 0) { + return -1; + } + } + return 0; +} + +/* + * Solaris ports cannot add the same file descriptor twice, once + * with read, once with write which is allowed by the tevent backend. + * Multiplex the existing fde, flag it as such so we can search for the + * correct fde on event triggering. + */ + +static void port_setup_multiplex_fd(struct port_event_context *port_ev, + struct tevent_fd *add_fde, + struct tevent_fd *mpx_fde) +{ + /* + * Make each fde->additional_data pointers point at each other + * so we can look them up from each other. They are now paired. + */ + mpx_fde->additional_data = add_fde; + add_fde->additional_data = mpx_fde; + + /* Now flag both fde's as being multiplexed. */ + mpx_fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_HAS_MPX; + add_fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_HAS_MPX; + + /* We need to keep the GOT_ERROR flag. */ + if (mpx_fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_GOT_ERROR) { + add_fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_GOT_ERROR; + } +} + +/* + Add the port event to the given fd_event, + Or modify an existing event. +*/ + +static int port_add_event(struct port_event_context *port_ev, struct tevent_fd *fde) +{ + int flags = port_map_flags(fde->flags); + struct tevent_fd *mpx_fde = NULL; + + fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR; + + if (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_MPX) { + /* + * This is already a multiplexed fde, we need to include both + * flags in the modified event. + */ + mpx_fde = talloc_get_type_abort(fde->additional_data, + struct tevent_fd); + + mpx_fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + mpx_fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR; + + flags |= port_map_flags(mpx_fde->flags); + } else { + /* + * Not (yet) a multiplexed event. See if there + * is already an event with the same fd. + */ + for (mpx_fde = port_ev->ev->fd_events; mpx_fde; mpx_fde = mpx_fde->next) { + if (mpx_fde->fd != fde->fd) { + continue; + } + if (mpx_fde == fde) { + continue; + } + /* Same fd. */ + break; + } + if (mpx_fde) { + if (mpx_fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_MPX) { + /* Logic error. Can't have more then 2 multiplexed fde's. */ + tevent_debug(port_ev->ev, TEVENT_DEBUG_FATAL, + "multiplex fde for fd[%d] is already multiplexed\n", + mpx_fde->fd); + return -1; + } + flags |= port_map_flags(mpx_fde->flags); + } + } + + if (!store_port_association(port_ev, + fde, + flags)) { + tevent_debug(port_ev->ev, TEVENT_DEBUG_FATAL, + "store_port_association failed for fd[%d]\n", + fde->fd); + return -1; + } + + /* Note we have an association now. */ + fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + /* Only if we want to read do we tell the event handler about errors. */ + if (fde->flags & TEVENT_FD_READ) { + fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR; + } + if (mpx_fde == NULL) { + return 0; + } + /* Set up the multiplex pointer. Does no harm if already multiplexed. */ + port_setup_multiplex_fd(port_ev, + fde, + mpx_fde); + + mpx_fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + /* Only if we want to read do we tell the event handler about errors. */ + if (mpx_fde->flags & TEVENT_FD_READ) { + mpx_fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR; + } + + return 0; +} + +/* + Delete the port association for the given fd_event. +*/ + +static void port_del_event(struct port_event_context *port_ev, struct tevent_fd *fde) +{ + struct tevent_fd *mpx_fde = NULL; + + fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR; + + if (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_MPX) { + /* + * This is a multiplexed fde, we need to remove + * both associations. + */ + mpx_fde = talloc_get_type_abort(fde->additional_data, + struct tevent_fd); + + mpx_fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + mpx_fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR; + mpx_fde->additional_data = NULL; + + fde->additional_data = NULL; + } + delete_port_association(port_ev, fde); +} + +/* + Add or remove the port event from the given fd_event +*/ +static int port_update_event(struct port_event_context *port_ev, struct tevent_fd *fde) +{ + bool got_error = (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_GOT_ERROR); + bool want_read = (fde->flags & TEVENT_FD_READ); + bool want_write = (fde->flags & TEVENT_FD_WRITE); + struct tevent_fd *mpx_fde = NULL; + + if (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_MPX) { + /* + * work out what the multiplexed fde wants. + */ + mpx_fde = talloc_get_type_abort(fde->additional_data, + struct tevent_fd); + if (mpx_fde->flags & TEVENT_FD_READ) { + want_read = true; + } + if (mpx_fde->flags & TEVENT_FD_WRITE) { + want_write = true; + } + } + + if (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION) { + /* There's already an association. */ + if (want_read || (want_write && !got_error)) { + return port_add_event(port_ev, fde); + } + /* + * If we want to match the select behavior, we need to remove the port event + * when the caller isn't interested in events. + */ + port_del_event(port_ev, fde); + return 0; + } + + /* There's no port event attached to the fde. */ + if (want_read || (want_write && !got_error)) { + return port_add_event(port_ev, fde); + } + return 0; +} + +/* + Cope with port_get returning EPOLLHP|EPOLLERR on an association. + Return true if there's nothing else to do, false if this event + needs further handling. +*/ + +static bool port_handle_hup_or_err(struct port_event_context *port_ev, + struct tevent_fd *fde) +{ + if (fde == NULL) { + return true; + } + + fde->additional_flags |= PORT_ADDITIONAL_FD_FLAG_GOT_ERROR; + /* + * If we only wait for TEVENT_FD_WRITE, we should not tell the + * event handler about it, and remove the port association, + * as we only report error when waiting for read events, + * to match the select() behavior. + */ + if (!(fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_REPORT_ERROR)) { + /* + * Do the same as the poll backend and + * remove the writable flag. + */ + fde->flags &= ~TEVENT_FD_WRITE; + return true; + } + /* This has TEVENT_FD_READ set, we're not finished. */ + return false; +} + +/* + Event loop handling using Solaris ports. +*/ +static int port_event_loop(struct port_event_context *port_ev, struct timeval *tvalp) +{ + int ret; +#define MAXEVENTS 1 + port_event_t events[MAXEVENTS]; + uint_t nget = 1; + uint_t max_events = MAXEVENTS; + uint_t i; + int port_errno; + struct timespec ts; + struct tevent_context *ev = port_ev->ev; + + if (tvalp) { + ts.tv_sec = tvalp->tv_sec; + ts.tv_nsec = tvalp->tv_usec * 1000; + } + + if (port_ev->ev->signal_events && + tevent_common_check_signal(ev)) { + return 0; + } + + /* + * Solaris triggers sending the event to the port + * at the time the port association is done. Postpone + * associating fd's until just before we get the events, + * otherwise we can deadlock. + */ + + if (associate_all_events(port_ev) != 0) { + return -1; + } + + tevent_trace_point_callback(ev, TEVENT_TRACE_BEFORE_WAIT); + ret = port_getn(port_ev->port_fd, events, max_events, &nget, &ts); + port_errno = errno; + tevent_trace_point_callback(ev, TEVENT_TRACE_AFTER_WAIT); + + if (ret == -1 && port_errno == EINTR) { + if (ev->signal_events) { + tevent_common_check_signal(ev); + } + /* + * If no signal handlers we got an unsolicited + * signal wakeup. This can happen with epoll + * too. Just return and ignore. + */ + return 0; + } + + if (ret == -1 && port_errno == ETIME) { + /* + * If errno is set to ETIME it is possible that we still got an event. + * In that case we need to go through the processing loop so that we + * reassociate the received event with the port or the association will + * be lost so check the value of nget is 0 before returning. + */ + if (nget == 0) { + /* we don't care about a possible delay here */ + tevent_common_loop_timer_delay(ev); + return 0; + } + /* + * Set the return value to 0 since we do not actually have an error and we + * do have events that need to be processed. This keeps us from getting + * caught in the generic error test. + */ + ret = 0; + } + + if (ret == -1) { + tevent_debug(ev, TEVENT_DEBUG_ERROR, + "port_get failed (%s)\n", + strerror(errno)); + return -1; + } + + for (i = 0; i < nget; i++) { + struct tevent_fd *mpx_fde = NULL; + struct tevent_fd *fde = NULL; + uint16_t flags = 0; + struct port_associate_vals *val = talloc_get_type(events[i].portev_user, + struct port_associate_vals); + if (val == NULL) { + tevent_debug(ev, TEVENT_DEBUG_ERROR, + "port_getn() gave bad data"); + return -1; + } + + /* Mark this event as needing to be re-associated. */ + val->associated_event = false; + + fde = val->fde; + + if (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_MPX) { + /* + * Save off the multiplexed event in case we need + * to use it to call the handler function. + */ + mpx_fde = talloc_get_type_abort(fde->additional_data, + struct tevent_fd); + } + + if (events[i].portev_events & (POLLHUP|POLLERR)) { + bool handled_fde = port_handle_hup_or_err(port_ev, fde); + bool handled_mpx = port_handle_hup_or_err(port_ev, mpx_fde); + + if (handled_fde && handled_mpx) { + return port_update_event(port_ev, fde); + } + + if (!handled_mpx) { + /* + * If the mpx event was the one that needs + * further handling, it's the TEVENT_FD_READ + * event so switch over and call that handler. + */ + fde = mpx_fde; + mpx_fde = NULL; + } + flags |= TEVENT_FD_READ; + } + + if (events[i].portev_events & POLLIN) { + flags |= TEVENT_FD_READ; + } + if (events[i].portev_events & POLLOUT) { + flags |= TEVENT_FD_WRITE; + } + + if (flags & TEVENT_FD_WRITE) { + if (fde->flags & TEVENT_FD_WRITE) { + mpx_fde = NULL; + } + if (mpx_fde && (mpx_fde->flags & TEVENT_FD_WRITE)) { + fde = mpx_fde; + mpx_fde = NULL; + } + + if (mpx_fde) { + /* Ensure we got the right fde. */ + if ((flags & fde->flags) == 0) { + fde = mpx_fde; + mpx_fde = NULL; + } + } + } + + /* + * Make sure we only pass the flags + * the handler is expecting. + */ + flags &= fde->flags; + if (flags) { + return tevent_common_invoke_fd_handler(fde, flags, NULL); + } + } + + return 0; +} + + +/* + create a port_event_context structure. +*/ +static int port_event_context_init(struct tevent_context *ev) +{ + int ret; + struct port_event_context *port_ev; + + /* + * We might be called during tevent_re_initialise() + * which means we need to free our old additional_data. + */ + TALLOC_FREE(ev->additional_data); + + port_ev = talloc_zero(ev, struct port_event_context); + if (!port_ev) { + return -1; + } + port_ev->ev = ev; + port_ev->port_fd = -1; + port_ev->pid = (pid_t)-1; + + ret = port_init_ctx(port_ev); + if (ret != 0) { + talloc_free(port_ev); + return ret; + } + + ev->additional_data = port_ev; + return 0; +} + +/* + destroy an fd_event +*/ +static int port_event_fd_destructor(struct tevent_fd *fde) +{ + struct tevent_context *ev = fde->event_ctx; + struct port_event_context *port_ev = NULL; + struct tevent_fd *mpx_fde = NULL; + int flags = (int)fde->flags; + + if (ev == NULL) { + return tevent_common_fd_destructor(fde); + } + + port_ev = talloc_get_type_abort(ev->additional_data, + struct port_event_context); + + DLIST_REMOVE(ev->fd_events, fde); + + if (fde->additional_flags & PORT_ADDITIONAL_FD_FLAG_HAS_MPX) { + mpx_fde = talloc_get_type_abort(fde->additional_data, + struct tevent_fd); + + fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_HAS_MPX; + mpx_fde->additional_flags &= ~PORT_ADDITIONAL_FD_FLAG_HAS_MPX; + + fde->additional_data = NULL; + mpx_fde->additional_data = NULL; + + fde->additional_flags &= PORT_ADDITIONAL_FD_FLAG_HAS_ASSOCIATION; + } + + (void)port_check_reopen(port_ev); + + if (mpx_fde != NULL) { + (void)port_update_event(port_ev, mpx_fde); + } + + fde->flags = 0; + (void)port_update_event(port_ev, fde); + fde->flags = flags; + + return tevent_common_fd_destructor(fde); +} + +/* + add a fd based event + return NULL on failure (memory allocation error) +*/ +static struct tevent_fd *port_event_add_fd(struct tevent_context *ev, TALLOC_CTX *mem_ctx, + int fd, uint16_t flags, + tevent_fd_handler_t handler, + void *private_data, + const char *handler_name, + const char *location) +{ + struct port_event_context *port_ev = + talloc_get_type_abort(ev->additional_data, + struct port_event_context); + struct tevent_fd *fde; + + fde = tevent_common_add_fd(ev, mem_ctx, fd, flags, + handler, private_data, + handler_name, location); + if (!fde) { + return NULL; + } + + talloc_set_destructor(fde, port_event_fd_destructor); + + if (port_check_reopen(port_ev) != 0) { + TALLOC_FREE(fde); + return NULL; + } + + if (port_update_event(port_ev, fde) != 0) { + TALLOC_FREE(fde); + return NULL; + } + + return fde; +} + +/* + set the fd event flags +*/ +static void port_event_set_fd_flags(struct tevent_fd *fde, uint16_t flags) +{ + struct tevent_context *ev; + struct port_event_context *port_ev; + + if (fde->flags == flags) { + return; + } + + ev = fde->event_ctx; + port_ev = talloc_get_type_abort(ev->additional_data, + struct port_event_context); + + fde->flags = flags; + + (void)port_check_reopen(port_ev); + (void)port_update_event(port_ev, fde); +} + +/* + do a single event loop using the events defined in ev +*/ +static int port_event_loop_once(struct tevent_context *ev, const char *location) +{ + struct port_event_context *port_ev = talloc_get_type(ev->additional_data, + struct port_event_context); + struct timeval tval; + + if (ev->signal_events && + tevent_common_check_signal(ev)) { + return 0; + } + + if (ev->threaded_contexts != NULL) { + tevent_common_threaded_activate_immediate(ev); + } + + if (ev->immediate_events && + tevent_common_loop_immediate(ev)) { + return 0; + } + + tval = tevent_common_loop_timer_delay(ev); + if (tevent_timeval_is_zero(&tval)) { + return 0; + } + + if (port_check_reopen(port_ev) != 0) { + errno = EINVAL; + return -1; + } + return port_event_loop(port_ev, &tval); +} + +static const struct tevent_ops port_event_ops = { + .context_init = port_event_context_init, + .add_fd = port_event_add_fd, + .set_fd_close_fn = tevent_common_fd_set_close_fn, + .get_fd_flags = tevent_common_fd_get_flags, + .set_fd_flags = port_event_set_fd_flags, + .add_timer = tevent_common_add_timer_v2, + .schedule_immediate = tevent_common_schedule_immediate, + .add_signal = tevent_common_add_signal, + .loop_once = port_event_loop_once, + .loop_wait = tevent_common_loop_wait, +}; + +_PRIVATE_ bool tevent_port_init(void) +{ + if (!tevent_register_backend("port", &port_event_ops)) { + return false; + } + tevent_set_default_backend("port"); + return true; +} |