/* * This function initiates a connection to the server assigned to this session * (s->target, s->si[1].addr.to). It will assign a server if none * is assigned yet. * It can return one of : * - SN_ERR_NONE if everything's OK * - SN_ERR_SRVTO if there are no more servers * - SN_ERR_SRVCL if the connection was refused by the server * - SN_ERR_PRXCOND if the connection has been limited by the proxy (maxconn) * - SN_ERR_RESOURCE if a system resource is lacking (eg: fd limits, ports, ...) * - SN_ERR_INTERNAL for any other purely internal errors * Additionnally, in the case of SN_ERR_RESOURCE, an emergency log will be emitted. * The server-facing stream interface is expected to hold a pre-allocated connection * in s->si[1].conn. */ int connect_server(struct session *s) { struct connection *cli_conn; struct connection *srv_conn; struct server *srv; int reuse = 0; int err; srv_conn = objt_conn(s->si[1].end); if (srv_conn) reuse = s->target == srv_conn->target; if (reuse) { /* Disable connection reuse if a dynamic source is used. * As long as we don't share connections between servers, * we don't need to disable connection reuse on no-idempotent * requests nor when PROXY protocol is used. */ srv = objt_server(s->target); if (srv && srv->conn_src.opts & CO_SRC_BIND) { if ((srv->conn_src.opts & CO_SRC_TPROXY_MASK) == CO_SRC_TPROXY_DYN) reuse = 0; } else if (s->be->conn_src.opts & CO_SRC_BIND) { if ((s->be->conn_src.opts & CO_SRC_TPROXY_MASK) == CO_SRC_TPROXY_DYN) reuse = 0; } } srv_conn = si_alloc_conn(&s->si[1], reuse); if (!srv_conn) return SN_ERR_RESOURCE; if (!(s->flags & SN_ADDR_SET)) { err = assign_server_address(s); if (err != SRV_STATUS_OK) return SN_ERR_INTERNAL; } if (!conn_xprt_ready(srv_conn)) { /* the target was only on the session, assign it to the SI now */ srv_conn->target = s->target; /* set the correct protocol on the output stream interface */ if (objt_server(s->target)) { conn_prepare(srv_conn, protocol_by_family(srv_conn->addr.to.ss_family), objt_server(s->target)->xprt); } else if (obj_type(s->target) == OBJ_TYPE_PROXY) { /* proxies exclusively run on raw_sock right now */ conn_prepare(srv_conn, protocol_by_family(srv_conn->addr.to.ss_family), &raw_sock); if (!objt_conn(s->si[1].end) || !objt_conn(s->si[1].end)->ctrl) return SN_ERR_INTERNAL; } else return SN_ERR_INTERNAL; /* how did we get there ? */ /* process the case where the server requires the PROXY protocol to be sent */ srv_conn->send_proxy_ofs = 0; if (objt_server(s->target) && objt_server(s->target)->pp_opts) { srv_conn->send_proxy_ofs = 1; /* must compute size */ cli_conn = objt_conn(s->si[0].end); if (cli_conn) conn_get_to_addr(cli_conn); } si_attach_conn(&s->si[1], srv_conn); assign_tproxy_address(s); } else { /* the connection is being reused, just re-attach it */ si_attach_conn(&s->si[1], srv_conn); s->flags |= SN_SRV_REUSED; } /* flag for logging source ip/port */ if (s->fe->options2 & PR_O2_SRC_ADDR) s->si[1].flags |= SI_FL_SRC_ADDR; /* disable lingering */ if (s->be->options & PR_O_TCP_NOLING) s->si[1].flags |= SI_FL_NOLINGER; err = si_connect(&s->si[1]); if (err != SN_ERR_NONE) return err; /* set connect timeout */ s->si[1].exp = tick_add_ifset(now_ms, s->be->timeout.connect); srv = objt_server(s->target); if (srv) { s->flags |= SN_CURR_SESS; srv->cur_sess++; if (srv->cur_sess > srv->counters.cur_sess_max) srv->counters.cur_sess_max = srv->cur_sess; if (s->be->lbprm.server_take_conn) s->be->lbprm.server_take_conn(srv); } return SN_ERR_NONE; /* connection is OK */ }
/* * Create a new peer session in assigned state (connect will start automatically) */ static struct stream *peer_session_create(struct peer *peer, struct peer_session *ps) { struct listener *l = LIST_NEXT(&peer->peers->peers_fe->conf.listeners, struct listener *, by_fe); struct proxy *p = (struct proxy *)l->frontend; /* attached frontend */ struct appctx *appctx; struct session *sess; struct stream *s; struct task *t; struct connection *conn; ps->reconnect = tick_add(now_ms, MS_TO_TICKS(5000)); ps->statuscode = PEER_SESS_SC_CONNECTCODE; s = NULL; appctx = appctx_new(&peer_applet); if (!appctx) goto out_close; appctx->st0 = PEER_SESS_ST_CONNECT; appctx->ctx.peers.ptr = (void *)ps; sess = session_new(p, l, &appctx->obj_type); if (!sess) { Alert("out of memory in peer_session_create().\n"); goto out_free_appctx; } if ((t = task_new()) == NULL) { Alert("out of memory in peer_session_create().\n"); goto out_free_sess; } t->nice = l->nice; if ((s = stream_new(sess, t, &appctx->obj_type)) == NULL) { Alert("Failed to initialize stream in peer_session_create().\n"); goto out_free_task; } /* The tasks below are normally what is supposed to be done by * fe->accept(). */ s->flags = SF_ASSIGNED|SF_ADDR_SET; /* applet is waiting for data */ si_applet_cant_get(&s->si[0]); appctx_wakeup(appctx); /* initiate an outgoing connection */ si_set_state(&s->si[1], SI_ST_ASS); /* automatically prepare the stream interface to connect to the * pre-initialized connection in si->conn. */ if (unlikely((conn = conn_new()) == NULL)) goto out_free_strm; conn_prepare(conn, peer->proto, peer->xprt); si_attach_conn(&s->si[1], conn); conn->target = s->target = &s->be->obj_type; memcpy(&conn->addr.to, &peer->addr, sizeof(conn->addr.to)); s->do_log = NULL; s->uniq_id = 0; s->res.flags |= CF_READ_DONTWAIT; l->nbconn++; /* warning! right now, it's up to the handler to decrease this */ p->feconn++;/* beconn will be increased later */ jobs++; if (!(s->sess->listener->options & LI_O_UNLIMITED)) actconn++; totalconn++; ps->appctx = appctx; ps->stream = s; return s; /* Error unrolling */ out_free_strm: LIST_DEL(&s->list); pool_free2(pool2_stream, s); out_free_task: task_free(t); out_free_sess: session_free(sess); out_free_appctx: appctx_free(appctx); out_close: return s; }