saproxy: Fix for systemd's event library not deduping fds.

This commit is contained in:
David Strauss 2013-10-15 18:55:25 -07:00
parent 075376d596
commit 32d3c80969

View file

@ -54,8 +54,8 @@ struct proxy {
struct connection {
int fd;
sd_event_source *w_recv;
sd_event_source *w_send;
uint32_t events;
sd_event_source *w;
struct connection *c_destination;
size_t buffer_filled_len;
size_t buffer_sent_len;
@ -64,12 +64,57 @@ struct connection {
static void free_connection(struct connection *c) {
log_debug("Freeing fd=%d (conn %p).", c->fd, c);
sd_event_source_unref(c->w_recv);
sd_event_source_unref(c->w_send);
sd_event_source_unref(c->w);
close(c->fd);
free(c);
}
static int add_event_to_connection(struct connection *c, uint32_t events) {
int r;
log_debug("Have revents=%d. Adding revents=%d.", c->events, events);
c->events |= events;
r = sd_event_source_set_io_events(c->w, c->events);
if (r < 0) {
log_error("Error %d setting revents: %s", r, strerror(-r));
return r;
}
r = sd_event_source_set_enabled(c->w, SD_EVENT_ON);
if (r < 0) {
log_error("Error %d enabling source: %s", r, strerror(-r));
return r;
}
return 0;
}
static int remove_event_from_connection(struct connection *c, uint32_t events) {
int r;
log_debug("Have revents=%d. Removing revents=%d.", c->events, events);
c->events &= ~events;
r = sd_event_source_set_io_events(c->w, c->events);
if (r < 0) {
log_error("Error %d setting revents: %s", r, strerror(-r));
return r;
}
if (c->events == 0) {
r = sd_event_source_set_enabled(c->w, SD_EVENT_OFF);
if (r < 0) {
log_error("Error %d disabling source: %s", r, strerror(-r));
return r;
}
}
return 0;
}
static int send_buffer(struct connection *sender) {
struct connection *receiver = sender->c_destination;
ssize_t len;
@ -104,17 +149,17 @@ static int send_buffer(struct connection *sender) {
/* If the buffer is full, disable events coming for recv. */
if (sender->buffer_filled_len == BUFFER_SIZE) {
r = sd_event_source_set_enabled(sender->w_recv, SD_EVENT_OFF);
r = remove_event_from_connection(sender, EPOLLIN);
if (r < 0) {
log_error("Error %d disabling recv for fd=%d: %s", r, sender->fd, strerror(-r));
log_error("Error %d disabling EPOLLIN for fd=%d: %s", r, sender->fd, strerror(-r));
return r;
}
}
/* Watch for when the recipient can be sent data again. */
r = sd_event_source_set_enabled(receiver->w_send, SD_EVENT_ON);
r = add_event_to_connection(receiver, EPOLLOUT);
if (r < 0) {
log_error("Error %d enabling send for fd=%d: %s", r, receiver->fd, strerror(-r));
log_error("Error %d enabling EPOLLOUT for fd=%d: %s", r, receiver->fd, strerror(-r));
return r;
}
log_debug("Done with recv for fd=%d. Waiting on send for fd=%d.", sender->fd, receiver->fd);
@ -125,17 +170,18 @@ static int send_buffer(struct connection *sender) {
sender->buffer_filled_len = 0;
sender->buffer_sent_len = 0;
/* Unmute the sender, in case the buffer was full. */
r = sd_event_source_set_enabled(sender->w_recv, SD_EVENT_ON);
/* Enable the sender's receive watcher, in case the buffer was
* full and we disabled it. */
r = add_event_to_connection(sender, EPOLLIN);
if (r < 0) {
log_error("Error %d enabling recv for fd=%d: %s", r, sender->fd, strerror(-r));
log_error("Error %d enabling EPOLLIN for fd=%d: %s", r, sender->fd, strerror(-r));
return r;
}
/* Mute the recipient, as we have no data to send now. */
r = sd_event_source_set_enabled(receiver->w_send, SD_EVENT_OFF);
/* Disable the other side's send watcher, as we have no data to send now. */
r = remove_event_from_connection(receiver, EPOLLOUT);
if (r < 0) {
log_error("Error %d disabling send for fd=%d: %s", r, receiver->fd, strerror(-r));
log_error("Error %d disabling EPOLLOUT for fd=%d: %s", r, receiver->fd, strerror(-r));
return r;
}
@ -149,14 +195,13 @@ static int transfer_data_cb(sd_event_source *s, int fd, uint32_t revents, void *
assert(revents & (EPOLLIN | EPOLLOUT));
assert(fd == c->fd);
assert(s == c->w);
log_debug("Got event revents=%d from fd=%d (conn %p).", revents, fd, c);
if (revents & EPOLLIN) {
log_debug("About to recv up to %lu bytes from fd=%d (%lu/BUFFER_SIZE).", BUFFER_SIZE - c->buffer_filled_len, fd, c->buffer_filled_len);
assert(s == c->w_recv);
/* Receive until the buffer's full, there's no more data,
* or the client/server disconnects. */
while (c->buffer_filled_len < BUFFER_SIZE) {
@ -190,7 +235,6 @@ static int transfer_data_cb(sd_event_source *s, int fd, uint32_t revents, void *
return send_buffer(c);
}
else {
assert(s == c->w_send);
return send_buffer(c->c_destination);
}
@ -213,43 +257,21 @@ static int connected_to_server_cb(sd_event_source *s, int fd, uint32_t revents,
log_debug("Connected to server. Initializing watchers for receiving data.");
/* A disabled send watcher for the server. */
r = sd_event_add_io(e, c_server_to_client->fd, EPOLLOUT, transfer_data_cb, c_server_to_client, &c_server_to_client->w_send);
if (r < 0) {
log_error("Error %d creating send watcher for fd=%d: %s", r, c_server_to_client->fd, strerror(-r));
goto fail;
}
r = sd_event_source_set_enabled(c_server_to_client->w_send, SD_EVENT_OFF);
if (r < 0) {
log_error("Error %d muting send for fd=%d: %s", r, c_server_to_client->fd, strerror(-r));
goto finish;
}
/* A recv watcher for the server. */
r = sd_event_add_io(e, c_server_to_client->fd, EPOLLIN, transfer_data_cb, c_server_to_client, &c_server_to_client->w_recv);
r = sd_event_add_io(e, c_server_to_client->fd, EPOLLIN, transfer_data_cb, c_server_to_client, &c_server_to_client->w);
if (r < 0) {
log_error("Error %d creating recv watcher for fd=%d: %s", r, c_server_to_client->fd, strerror(-r));
goto fail;
}
/* A disabled send watcher for the client. */
r = sd_event_add_io(e, c_client_to_server->fd, EPOLLOUT, transfer_data_cb, c_client_to_server, &c_client_to_server->w_send);
if (r < 0) {
log_error("Error %d creating send watcher for fd=%d: %s", r, c_client_to_server->fd, strerror(-r));
goto fail;
}
r = sd_event_source_set_enabled(c_client_to_server->w_send, SD_EVENT_OFF);
if (r < 0) {
log_error("Error %d muting send for fd=%d: %s", r, c_client_to_server->fd, strerror(-r));
goto finish;
}
c_server_to_client->events = EPOLLIN;
/* A recv watcher for the client. */
r = sd_event_add_io(e, c_client_to_server->fd, EPOLLIN, transfer_data_cb, c_client_to_server, &c_client_to_server->w_recv);
r = sd_event_add_io(e, c_client_to_server->fd, EPOLLIN, transfer_data_cb, c_client_to_server, &c_client_to_server->w);
if (r < 0) {
log_error("Error %d creating recv watcher for fd=%d: %s", r, c_client_to_server->fd, strerror(-r));
goto fail;
}
c_client_to_server->events = EPOLLIN;
goto finish;
@ -383,7 +405,7 @@ static int accept_cb(sd_event_source *s, int fd, uint32_t revents, void *userdat
log_debug("Server fd=%d (conn %p) successfully initialized.", c_server_to_client->fd, c_server_to_client);
/* Initialize watcher for send to server; this shows connectivity. */
r = sd_event_add_io(sd_event_get(s), c_server_to_client->fd, EPOLLOUT, connected_to_server_cb, c_server_to_client, &c_server_to_client->w_send);
r = sd_event_add_io(sd_event_get(s), c_server_to_client->fd, EPOLLOUT, connected_to_server_cb, c_server_to_client, &c_server_to_client->w);
if (r < 0) {
log_error("Error %d creating connectivity watcher for fd=%d: %s", r, c_server_to_client->fd, strerror(-r));
goto fail;