void *ad_open(const char *fn, struct adinfo *nfo) {
adecoder *d = (adecoder*) calloc(1, sizeof(adecoder));
ad_clear_nfo(nfo);
d->b = choose_backend(fn);
if (!d->b) {
dbg(0, "fatal: no decoder backend available");
free(d);
return NULL;
}
d->d = d->b->open(fn, nfo);
if (!d->d) {
free(d);
return NULL;
}
return (void*)d;
}
/*
* choose_backend parses incoming HTTP request and routes it to the appropriate
* backend. It assumes that clients don't do HTTP pipelining, handling only
* one request request for each connection. To give a hint to backend about
* this it inserts "Connection: close" header into each forwarded request.
*/
static int connect_backend(struct conn_data *conn, struct http_message *hm) {
struct mg_connection *nc = conn->client.nc;
struct http_backend *be = choose_backend(hm);
write_log("%ld %.*s %.*s backend=%s\n", (long) time(NULL),
(int) hm->method.len, hm->method.p, (int) hm->uri.len, hm->uri.p,
be ? be->host_port : "not defined");
if (be == NULL) return 0;
if (be->redirect != 0) {
mg_printf(nc, "HTTP/1.1 302 Found\r\nLocation: %s\r\n\r\n", be->host_port);
return 1;
}
struct be_conn *bec = get_conn(be);
if (bec != NULL) {
bec->nc->handler = ev_handler;
#ifdef DEBUG
write_log("conn=%p to %p (%s) reusing bec=%p\n", conn, be, be->host_port,
bec);
#endif
} else {
bec = malloc(sizeof(*conn->be_conn));
memset(bec, 0, sizeof(*bec));
bec->nc = mg_connect(nc->mgr, be->host_port, ev_handler);
#ifdef DEBUG
write_log("conn=%p new conn to %p (%s) bec=%p\n", conn, be, be->host_port,
bec);
#endif
if (bec->nc == NULL) {
free(bec);
write_log("Connection to [%s] failed\n", be->host_port);
return 0;
}
}
bec->be = be;
conn->be_conn = bec;
conn->backend.nc = bec->nc;
conn->backend.nc->user_data = conn;
mg_set_protocol_http_websocket(conn->backend.nc);
return 1;
}
static void ev_handler(struct ns_connection *nc, int ev, void *ev_data) {
struct iobuf *io = &nc->recv_iobuf;
struct ns_connection *peer = (struct ns_connection *) nc->proto_data;
switch (ev) {
case NS_CONNECT:
if (* (int *) ev_data != 0) {
/* TODO(lsm): mark backend as defunct, try it later on */
fprintf(stderr, "connect(%s) failed\n",
s_http_backends[(int) nc->user_data].host_port);
ns_printf(nc->proto_data, "%s%s\r\n", s_error_500, s_content_len_0);
}
break;
case NS_RECV:
/*
* For incoming client connection, nc->proto_data points to the respective
* backend connection. For backend connection, nc->proto_data points
* to the respective incoming client connection.
*/
if (peer == NULL) {
choose_backend(nc);
} else {
/* Forward data to peer */
ns_send(peer, io->buf, io->len);
iobuf_remove(io, io->len);
}
break;
case NS_CLOSE:
/* We're closing, detach our peer */
if (peer != NULL) {
peer->proto_data = NULL;
peer->flags |= NSF_SEND_AND_CLOSE;
}
break;
}
}
