``` case SSL3_ST_SW_SRVR_HELLO_A: case SSL3_ST_SW_SRVR_HELLO_B: ret=ssl3_send_server_hello(s); if (ret <= 0) goto end; #ifndef OPENSSL_NO_TLSEXT if (s->hit) { if (s->tlsext_ticket_expected) s->state=SSL3_ST_SW_SESSION_TICKET_A; else s->state=SSL3_ST_SW_CHANGE_A; } #else if (s->hit) s->state=SSL3_ST_SW_CHANGE_A; #endif else s->state=SSL3_ST_SW_CERT_A; s->init_num=0; break; ``` ``` if ((cb != NULL) && (s->state != state)) { new_state=s->state; s->state=state; cb(s,SSL_CB_ACCEPT_LOOP,1); s->state=new_state; } ``` As non blocking io ssl3_send_server_hello() can return -1 (can't to fit all bytes of record in wire), and no CallBack of tor's tor_tls_server_info_callback(). Later SSL_accept() calling callback with s->state == SSL3_ST_SW_SRVR_HELLO_B. If relay can't to fit server's hello in wire once, it never can finish v2 link hanshake. **Trac**: **Username**: troll_un