/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (the "License"). * You may not use this file except in compliance with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. */ /* This file contains all TCP output processing functions. */ #include #include #include #include #include #include #define _SUN_TPI_VERSION 2 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include static mblk_t *tcp_get_seg_mp(tcp_t *, uint32_t, int32_t *); static void tcp_wput_cmdblk(queue_t *, mblk_t *); static void tcp_wput_flush(tcp_t *, mblk_t *); static void tcp_wput_iocdata(tcp_t *tcp, mblk_t *mp); static int tcp_xmit_end(tcp_t *); static int tcp_send(tcp_t *, const int, const int, const int, const int, int *, uint_t *, int *, mblk_t **, mblk_t *); static void tcp_xmit_early_reset(char *, mblk_t *, uint32_t, uint32_t, int, ip_recv_attr_t *, ip_stack_t *, conn_t *); static boolean_t tcp_send_rst_chk(tcp_stack_t *); static void tcp_process_shrunk_swnd(tcp_t *, uint32_t); static void tcp_fill_header(tcp_t *, uchar_t *, clock_t, int); /* * Functions called directly via squeue having a prototype of edesc_t. */ static void tcp_wput_nondata(void *, mblk_t *, void *, ip_recv_attr_t *); static void tcp_wput_ioctl(void *, mblk_t *, void *, ip_recv_attr_t *); static void tcp_wput_proto(void *, mblk_t *, void *, ip_recv_attr_t *); /* * This controls how tiny a write must be before we try to copy it * into the mblk on the tail of the transmit queue. Not much * speedup is observed for values larger than sixteen. Zero will * disable the optimisation. */ static int tcp_tx_pull_len = 16; void tcp_wput(queue_t *q, mblk_t *mp) { conn_t *connp = Q_TO_CONN(q); tcp_t *tcp; void (*output_proc)(); t_scalar_t type; uchar_t *rptr; struct iocblk *iocp; size_t size; ASSERT(connp->conn_ref >= 2); switch (DB_TYPE(mp)) { case M_DATA: tcp = connp->conn_tcp; ASSERT(tcp != NULL); size = msgdsize(mp); mutex_enter(&tcp->tcp_non_sq_lock); tcp->tcp_squeue_bytes += size; if (TCP_UNSENT_BYTES(tcp) > connp->conn_sndbuf) { tcp_setqfull(tcp); } mutex_exit(&tcp->tcp_non_sq_lock); CONN_INC_REF(connp); SQUEUE_ENTER_ONE(connp->conn_sqp, mp, tcp_output, connp, NULL, tcp_squeue_flag, SQTAG_TCP_OUTPUT); return; case M_CMD: tcp_wput_cmdblk(q, mp); return; case M_PROTO: case M_PCPROTO: /* * if it is a snmp message, don't get behind the squeue */ tcp = connp->conn_tcp; rptr = mp->b_rptr; if ((mp->b_wptr - rptr) >= sizeof (t_scalar_t)) { type = ((union T_primitives *)rptr)->type; } else { if (connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE, "tcp_wput_proto, dropping one..."); } freemsg(mp); return; } if (type == T_SVR4_OPTMGMT_REQ) { /* * All Solaris components should pass a db_credp * for this TPI message, hence we ASSERT. * But in case there is some other M_PROTO that looks * like a TPI message sent by some other kernel * component, we check and return an error. */ cred_t *cr = msg_getcred(mp, NULL); ASSERT(cr != NULL); if (cr == NULL) { tcp_err_ack(tcp, mp, TSYSERR, EINVAL); return; } if (snmpcom_req(q, mp, tcp_snmp_set, ip_snmp_get, cr)) { /* * This was a SNMP request */ return; } else { output_proc = tcp_wput_proto; } } else { output_proc = tcp_wput_proto; } break; case M_IOCTL: /* * Most ioctls can be processed right away without going via * squeues - process them right here. Those that do require * squeue (currently _SIOCSOCKFALLBACK) * are processed by tcp_wput_ioctl(). */ iocp = (struct iocblk *)mp->b_rptr; tcp = connp->conn_tcp; switch (iocp->ioc_cmd) { case TCP_IOC_ABORT_CONN: tcp_ioctl_abort_conn(q, mp); return; case TI_GETPEERNAME: case TI_GETMYNAME: mi_copyin(q, mp, NULL, SIZEOF_STRUCT(strbuf, iocp->ioc_flag)); return; default: output_proc = tcp_wput_ioctl; break; } break; default: output_proc = tcp_wput_nondata; break; } CONN_INC_REF(connp); SQUEUE_ENTER_ONE(connp->conn_sqp, mp, output_proc, connp, NULL, tcp_squeue_flag, SQTAG_TCP_WPUT_OTHER); } /* * The TCP normal data output path. * NOTE: the logic of the fast path is duplicated from this function. */ void tcp_wput_data(tcp_t *tcp, mblk_t *mp, boolean_t urgent) { int len; mblk_t *local_time; mblk_t *mp1; uint32_t snxt; int tail_unsent; int tcpstate; int usable = 0; mblk_t *xmit_tail; int32_t mss; int32_t num_sack_blk = 0; int32_t total_hdr_len; int32_t tcp_hdr_len; int rc; tcp_stack_t *tcps = tcp->tcp_tcps; conn_t *connp = tcp->tcp_connp; clock_t now = LBOLT_FASTPATH; tcpstate = tcp->tcp_state; if (mp == NULL) { /* * tcp_wput_data() with NULL mp should only be called when * there is unsent data. */ ASSERT(tcp->tcp_unsent > 0); /* Really tacky... but we need this for detached closes. */ len = tcp->tcp_unsent; goto data_null; } ASSERT(mp->b_datap->db_type == M_DATA); /* * Don't allow data after T_ORDREL_REQ or T_DISCON_REQ, * or before a connection attempt has begun. */ if (tcpstate < TCPS_SYN_SENT || tcpstate > TCPS_CLOSE_WAIT || (tcp->tcp_valid_bits & TCP_FSS_VALID) != 0) { if ((tcp->tcp_valid_bits & TCP_FSS_VALID) != 0) { #ifdef DEBUG cmn_err(CE_WARN, "tcp_wput_data: data after ordrel, %s", tcp_display(tcp, NULL, DISP_ADDR_AND_PORT)); #else if (connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_TRACE|SL_ERROR, "tcp_wput_data: data after ordrel, %s\n", tcp_display(tcp, NULL, DISP_ADDR_AND_PORT)); } #endif /* DEBUG */ } if (tcp->tcp_snd_zcopy_aware && (mp->b_datap->db_struioflag & STRUIO_ZCNOTIFY)) tcp_zcopy_notify(tcp); freemsg(mp); mutex_enter(&tcp->tcp_non_sq_lock); if (tcp->tcp_flow_stopped && TCP_UNSENT_BYTES(tcp) <= connp->conn_sndlowat) { tcp_clrqfull(tcp); } mutex_exit(&tcp->tcp_non_sq_lock); return; } /* Strip empties */ for (;;) { ASSERT((uintptr_t)(mp->b_wptr - mp->b_rptr) <= (uintptr_t)INT_MAX); len = (int)(mp->b_wptr - mp->b_rptr); if (len > 0) break; mp1 = mp; mp = mp->b_cont; freeb(mp1); if (mp == NULL) { return; } } /* If we are the first on the list ... */ if (tcp->tcp_xmit_head == NULL) { tcp->tcp_xmit_head = mp; tcp->tcp_xmit_tail = mp; tcp->tcp_xmit_tail_unsent = len; } else { /* If tiny tx and room in txq tail, pullup to save mblks. */ struct datab *dp; mp1 = tcp->tcp_xmit_last; if (len < tcp_tx_pull_len && (dp = mp1->b_datap)->db_ref == 1 && dp->db_lim - mp1->b_wptr >= len) { ASSERT(len > 0); ASSERT(!mp1->b_cont); if (len == 1) { *mp1->b_wptr++ = *mp->b_rptr; } else { bcopy(mp->b_rptr, mp1->b_wptr, len); mp1->b_wptr += len; } if (mp1 == tcp->tcp_xmit_tail) tcp->tcp_xmit_tail_unsent += len; mp1->b_cont = mp->b_cont; if (tcp->tcp_snd_zcopy_aware && (mp->b_datap->db_struioflag & STRUIO_ZCNOTIFY)) mp1->b_datap->db_struioflag |= STRUIO_ZCNOTIFY; freeb(mp); mp = mp1; } else { tcp->tcp_xmit_last->b_cont = mp; } len += tcp->tcp_unsent; } /* Tack on however many more positive length mblks we have */ if ((mp1 = mp->b_cont) != NULL) { do { int tlen; ASSERT((uintptr_t)(mp1->b_wptr - mp1->b_rptr) <= (uintptr_t)INT_MAX); tlen = (int)(mp1->b_wptr - mp1->b_rptr); if (tlen <= 0) { mp->b_cont = mp1->b_cont; freeb(mp1); } else { len += tlen; mp = mp1; } } while ((mp1 = mp->b_cont) != NULL); } tcp->tcp_xmit_last = mp; tcp->tcp_unsent = len; if (urgent) usable = 1; data_null: snxt = tcp->tcp_snxt; xmit_tail = tcp->tcp_xmit_tail; tail_unsent = tcp->tcp_xmit_tail_unsent; /* * Note that tcp_mss has been adjusted to take into account the * timestamp option if applicable. Because SACK options do not * appear in every TCP segments and they are of variable lengths, * they cannot be included in tcp_mss. Thus we need to calculate * the actual segment length when we need to send a segment which * includes SACK options. */ if (tcp->tcp_snd_sack_ok && tcp->tcp_num_sack_blk > 0) { int32_t opt_len; num_sack_blk = MIN(tcp->tcp_max_sack_blk, tcp->tcp_num_sack_blk); opt_len = num_sack_blk * sizeof (sack_blk_t) + TCPOPT_NOP_LEN * 2 + TCPOPT_HEADER_LEN; mss = tcp->tcp_mss - opt_len; total_hdr_len = connp->conn_ht_iphc_len + opt_len; tcp_hdr_len = connp->conn_ht_ulp_len + opt_len; } else { mss = tcp->tcp_mss; total_hdr_len = connp->conn_ht_iphc_len; tcp_hdr_len = connp->conn_ht_ulp_len; } if ((tcp->tcp_suna == snxt) && !tcp->tcp_localnet && (TICK_TO_MSEC(now - tcp->tcp_last_recv_time) >= tcp->tcp_rto)) { TCP_SET_INIT_CWND(tcp, mss, tcps->tcps_slow_start_after_idle); } if (tcpstate == TCPS_SYN_RCVD) { /* * The three-way connection establishment handshake is not * complete yet. We want to queue the data for transmission * after entering ESTABLISHED state (RFC793). A jump to * "done" label effectively leaves data on the queue. */ goto done; } else { int usable_r; /* * In the special case when cwnd is zero, which can only * happen if the connection is ECN capable, return now. * New segments is sent using tcp_timer(). The timer * is set in tcp_input_data(). */ if (tcp->tcp_cwnd == 0) { /* * Note that tcp_cwnd is 0 before 3-way handshake is * finished. */ ASSERT(tcp->tcp_ecn_ok || tcp->tcp_state < TCPS_ESTABLISHED); return; } /* NOTE: trouble if xmitting while SYN not acked? */ usable_r = snxt - tcp->tcp_suna; usable_r = tcp->tcp_swnd - usable_r; /* * Check if the receiver has shrunk the window. If * tcp_wput_data() with NULL mp is called, tcp_fin_sent * cannot be set as there is unsent data, so FIN cannot * be sent out. Otherwise, we need to take into account * of FIN as it consumes an "invisible" sequence number. */ ASSERT(tcp->tcp_fin_sent == 0); if (usable_r < 0) { /* * The receiver has shrunk the window and we have sent * -usable_r date beyond the window, re-adjust. * * If TCP window scaling is enabled, there can be * round down error as the advertised receive window * is actually right shifted n bits. This means that * the lower n bits info is wiped out. It will look * like the window is shrunk. Do a check here to * see if the shrunk amount is actually within the * error in window calculation. If it is, just * return. Note that this check is inside the * shrunk window check. This makes sure that even * though tcp_process_shrunk_swnd() is not called, * we will stop further processing. */ if ((-usable_r >> tcp->tcp_snd_ws) > 0) { tcp_process_shrunk_swnd(tcp, -usable_r); } return; } /* usable = MIN(swnd, cwnd) - unacked_bytes */ if (tcp->tcp_swnd > tcp->tcp_cwnd) usable_r -= tcp->tcp_swnd - tcp->tcp_cwnd; /* usable = MIN(usable, unsent) */ if (usable_r > len) usable_r = len; /* usable = MAX(usable, {1 for urgent, 0 for data}) */ if (usable_r > 0) { usable = usable_r; } else { /* Bypass all other unnecessary processing. */ goto done; } } local_time = (mblk_t *)now; /* * "Our" Nagle Algorithm. This is not the same as in the old * BSD. This is more in line with the true intent of Nagle. * * The conditions are: * 1. The amount of unsent data (or amount of data which can be * sent, whichever is smaller) is less than Nagle limit. * 2. The last sent size is also less than Nagle limit. * 3. There is unack'ed data. * 4. Urgent pointer is not set. Send urgent data ignoring the * Nagle algorithm. This reduces the probability that urgent * bytes get "merged" together. * 5. The app has not closed the connection. This eliminates the * wait time of the receiving side waiting for the last piece of * (small) data. * * If all are satisified, exit without sending anything. Note * that Nagle limit can be smaller than 1 MSS. Nagle limit is * the smaller of 1 MSS and global tcp_naglim_def (default to be * 4095). */ if (usable < (int)tcp->tcp_naglim && tcp->tcp_naglim > tcp->tcp_last_sent_len && snxt != tcp->tcp_suna && !(tcp->tcp_valid_bits & TCP_URG_VALID) && !(tcp->tcp_valid_bits & TCP_FSS_VALID)) { goto done; } /* * If tcp_zero_win_probe is not set and the tcp->tcp_cork option * is set, then we have to force TCP not to send partial segment * (smaller than MSS bytes). We are calculating the usable now * based on full mss and will save the rest of remaining data for * later. When tcp_zero_win_probe is set, TCP needs to send out * something to do zero window probe. */ if (tcp->tcp_cork && !tcp->tcp_zero_win_probe) { if (usable < mss) goto done; usable = (usable / mss) * mss; } /* Update the latest receive window size in TCP header. */ tcp->tcp_tcpha->tha_win = htons(tcp->tcp_rwnd >> tcp->tcp_rcv_ws); /* Send the packet. */ rc = tcp_send(tcp, mss, total_hdr_len, tcp_hdr_len, num_sack_blk, &usable, &snxt, &tail_unsent, &xmit_tail, local_time); /* Pretend that all we were trying to send really got sent */ if (rc < 0 && tail_unsent < 0) { do { xmit_tail = xmit_tail->b_cont; xmit_tail->b_prev = local_time; ASSERT((uintptr_t)(xmit_tail->b_wptr - xmit_tail->b_rptr) <= (uintptr_t)INT_MAX); tail_unsent += (int)(xmit_tail->b_wptr - xmit_tail->b_rptr); } while (tail_unsent < 0); } done:; tcp->tcp_xmit_tail = xmit_tail; tcp->tcp_xmit_tail_unsent = tail_unsent; len = tcp->tcp_snxt - snxt; if (len) { /* * If new data was sent, need to update the notsack * list, which is, afterall, data blocks that have * not been sack'ed by the receiver. New data is * not sack'ed. */ if (tcp->tcp_snd_sack_ok && tcp->tcp_notsack_list != NULL) { /* len is a negative value. */ tcp->tcp_pipe -= len; tcp_notsack_update(&(tcp->tcp_notsack_list), tcp->tcp_snxt, snxt, &(tcp->tcp_num_notsack_blk), &(tcp->tcp_cnt_notsack_list)); } tcp->tcp_snxt = snxt + tcp->tcp_fin_sent; tcp->tcp_rack = tcp->tcp_rnxt; tcp->tcp_rack_cnt = 0; if ((snxt + len) == tcp->tcp_suna) { TCP_TIMER_RESTART(tcp, tcp->tcp_rto); } } else if (snxt == tcp->tcp_suna && tcp->tcp_swnd == 0) { /* * Didn't send anything. Make sure the timer is running * so that we will probe a zero window. */ TCP_TIMER_RESTART(tcp, tcp->tcp_rto); } /* Note that len is the amount we just sent but with a negative sign */ tcp->tcp_unsent += len; mutex_enter(&tcp->tcp_non_sq_lock); if (tcp->tcp_flow_stopped) { if (TCP_UNSENT_BYTES(tcp) <= connp->conn_sndlowat) { tcp_clrqfull(tcp); } } else if (TCP_UNSENT_BYTES(tcp) >= connp->conn_sndbuf) { if (!(tcp->tcp_detached)) tcp_setqfull(tcp); } mutex_exit(&tcp->tcp_non_sq_lock); } /* * Initial STREAMS write side put() procedure for sockets. It tries to * handle the T_CAPABILITY_REQ which sockfs sends down while setting * up the socket without using the squeue. Non T_CAPABILITY_REQ messages * are handled by tcp_wput() as usual. * * All further messages will also be handled by tcp_wput() because we cannot * be sure that the above short cut is safe later. */ void tcp_wput_sock(queue_t *wq, mblk_t *mp) { conn_t *connp = Q_TO_CONN(wq); tcp_t *tcp = connp->conn_tcp; struct T_capability_req *car = (struct T_capability_req *)mp->b_rptr; ASSERT(wq->q_qinfo == &tcp_sock_winit); wq->q_qinfo = &tcp_winit; ASSERT(IPCL_IS_TCP(connp)); ASSERT(TCP_IS_SOCKET(tcp)); if (DB_TYPE(mp) == M_PCPROTO && MBLKL(mp) == sizeof (struct T_capability_req) && car->PRIM_type == T_CAPABILITY_REQ) { tcp_capability_req(tcp, mp); return; } tcp_wput(wq, mp); } /* ARGSUSED */ void tcp_wput_fallback(queue_t *wq, mblk_t *mp) { #ifdef DEBUG cmn_err(CE_CONT, "tcp_wput_fallback: Message during fallback \n"); #endif freemsg(mp); } /* * Call by tcp_wput() to handle misc non M_DATA messages. */ /* ARGSUSED */ static void tcp_wput_nondata(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; ASSERT(DB_TYPE(mp) != M_IOCTL); /* * TCP is D_MP and qprocsoff() is done towards the end of the tcp_close. * Once the close starts, streamhead and sockfs will not let any data * packets come down (close ensures that there are no threads using the * queue and no new threads will come down) but since qprocsoff() * hasn't happened yet, a M_FLUSH or some non data message might * get reflected back (in response to our own FLUSHRW) and get * processed after tcp_close() is done. The conn would still be valid * because a ref would have added but we need to check the state * before actually processing the packet. */ if (TCP_IS_DETACHED(tcp) || (tcp->tcp_state == TCPS_CLOSED)) { freemsg(mp); return; } switch (DB_TYPE(mp)) { case M_IOCDATA: tcp_wput_iocdata(tcp, mp); break; case M_FLUSH: tcp_wput_flush(tcp, mp); break; default: ip_wput_nondata(connp->conn_wq, mp); break; } } /* tcp_wput_flush is called by tcp_wput_nondata to handle M_FLUSH messages. */ static void tcp_wput_flush(tcp_t *tcp, mblk_t *mp) { uchar_t fval = *mp->b_rptr; mblk_t *tail; conn_t *connp = tcp->tcp_connp; queue_t *q = connp->conn_wq; /* TODO: How should flush interact with urgent data? */ if ((fval & FLUSHW) && tcp->tcp_xmit_head != NULL && !(tcp->tcp_valid_bits & TCP_URG_VALID)) { /* * Flush only data that has not yet been put on the wire. If * we flush data that we have already transmitted, life, as we * know it, may come to an end. */ tail = tcp->tcp_xmit_tail; tail->b_wptr -= tcp->tcp_xmit_tail_unsent; tcp->tcp_xmit_tail_unsent = 0; tcp->tcp_unsent = 0; if (tail->b_wptr != tail->b_rptr) tail = tail->b_cont; if (tail) { mblk_t **excess = &tcp->tcp_xmit_head; for (;;) { mblk_t *mp1 = *excess; if (mp1 == tail) break; tcp->tcp_xmit_tail = mp1; tcp->tcp_xmit_last = mp1; excess = &mp1->b_cont; } *excess = NULL; tcp_close_mpp(&tail); if (tcp->tcp_snd_zcopy_aware) tcp_zcopy_notify(tcp); } /* * We have no unsent data, so unsent must be less than * conn_sndlowat, so re-enable flow. */ mutex_enter(&tcp->tcp_non_sq_lock); if (tcp->tcp_flow_stopped) { tcp_clrqfull(tcp); } mutex_exit(&tcp->tcp_non_sq_lock); } /* * TODO: you can't just flush these, you have to increase rwnd for one * thing. For another, how should urgent data interact? */ if (fval & FLUSHR) { *mp->b_rptr = fval & ~FLUSHW; /* XXX */ qreply(q, mp); return; } freemsg(mp); } /* * tcp_wput_iocdata is called by tcp_wput_nondata to handle all M_IOCDATA * messages. */ static void tcp_wput_iocdata(tcp_t *tcp, mblk_t *mp) { mblk_t *mp1; struct iocblk *iocp = (struct iocblk *)mp->b_rptr; STRUCT_HANDLE(strbuf, sb); uint_t addrlen; conn_t *connp = tcp->tcp_connp; queue_t *q = connp->conn_wq; /* Make sure it is one of ours. */ switch (iocp->ioc_cmd) { case TI_GETMYNAME: case TI_GETPEERNAME: break; default: /* * If the conn is closing, then error the ioctl here. Otherwise * use the CONN_IOCTLREF_* macros to hold off tcp_close until * we're done here. */ mutex_enter(&connp->conn_lock); if (connp->conn_state_flags & CONN_CLOSING) { mutex_exit(&connp->conn_lock); iocp->ioc_error = EINVAL; mp->b_datap->db_type = M_IOCNAK; iocp->ioc_count = 0; qreply(q, mp); return; } CONN_INC_IOCTLREF_LOCKED(connp); ip_wput_nondata(q, mp); CONN_DEC_IOCTLREF(connp); return; } switch (mi_copy_state(q, mp, &mp1)) { case -1: return; case MI_COPY_CASE(MI_COPY_IN, 1): break; case MI_COPY_CASE(MI_COPY_OUT, 1): /* Copy out the strbuf. */ mi_copyout(q, mp); return; case MI_COPY_CASE(MI_COPY_OUT, 2): /* All done. */ mi_copy_done(q, mp, 0); return; default: mi_copy_done(q, mp, EPROTO); return; } /* Check alignment of the strbuf */ if (!OK_32PTR(mp1->b_rptr)) { mi_copy_done(q, mp, EINVAL); return; } STRUCT_SET_HANDLE(sb, iocp->ioc_flag, (void *)mp1->b_rptr); if (connp->conn_family == AF_INET) addrlen = sizeof (sin_t); else addrlen = sizeof (sin6_t); if (STRUCT_FGET(sb, maxlen) < addrlen) { mi_copy_done(q, mp, EINVAL); return; } switch (iocp->ioc_cmd) { case TI_GETMYNAME: break; case TI_GETPEERNAME: if (tcp->tcp_state < TCPS_SYN_RCVD) { mi_copy_done(q, mp, ENOTCONN); return; } break; } mp1 = mi_copyout_alloc(q, mp, STRUCT_FGETP(sb, buf), addrlen, B_TRUE); if (!mp1) return; STRUCT_FSET(sb, len, addrlen); switch (((struct iocblk *)mp->b_rptr)->ioc_cmd) { case TI_GETMYNAME: (void) conn_getsockname(connp, (struct sockaddr *)mp1->b_wptr, &addrlen); break; case TI_GETPEERNAME: (void) conn_getpeername(connp, (struct sockaddr *)mp1->b_wptr, &addrlen); break; } mp1->b_wptr += addrlen; /* Copy out the address */ mi_copyout(q, mp); } /* * tcp_wput_ioctl is called by tcp_wput_nondata() to handle all M_IOCTL * messages. */ /* ARGSUSED */ static void tcp_wput_ioctl(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; queue_t *q = connp->conn_wq; struct iocblk *iocp; ASSERT(DB_TYPE(mp) == M_IOCTL); /* * Try and ASSERT the minimum possible references on the * conn early enough. Since we are executing on write side, * the connection is obviously not detached and that means * there is a ref each for TCP and IP. Since we are behind * the squeue, the minimum references needed are 3. If the * conn is in classifier hash list, there should be an * extra ref for that (we check both the possibilities). */ ASSERT((connp->conn_fanout != NULL && connp->conn_ref >= 4) || (connp->conn_fanout == NULL && connp->conn_ref >= 3)); iocp = (struct iocblk *)mp->b_rptr; switch (iocp->ioc_cmd) { case _SIOCSOCKFALLBACK: /* * Either sockmod is about to be popped and the socket * would now be treated as a plain stream, or a module * is about to be pushed so we could no longer use read- * side synchronous streams for fused loopback tcp. * Drain any queued data and disable direct sockfs * interface from now on. */ if (!tcp->tcp_issocket) { DB_TYPE(mp) = M_IOCNAK; iocp->ioc_error = EINVAL; } else { tcp_use_pure_tpi(tcp); DB_TYPE(mp) = M_IOCACK; iocp->ioc_error = 0; } iocp->ioc_count = 0; iocp->ioc_rval = 0; qreply(q, mp); return; } /* * If the conn is closing, then error the ioctl here. Otherwise bump the * conn_ioctlref to hold off tcp_close until we're done here. */ mutex_enter(&(connp)->conn_lock); if ((connp)->conn_state_flags & CONN_CLOSING) { mutex_exit(&(connp)->conn_lock); iocp->ioc_error = EINVAL; mp->b_datap->db_type = M_IOCNAK; iocp->ioc_count = 0; qreply(q, mp); return; } CONN_INC_IOCTLREF_LOCKED(connp); ip_wput_nondata(q, mp); CONN_DEC_IOCTLREF(connp); } /* * This routine is called by tcp_wput() to handle all TPI requests. */ /* ARGSUSED */ static void tcp_wput_proto(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; union T_primitives *tprim = (union T_primitives *)mp->b_rptr; uchar_t *rptr; t_scalar_t type; cred_t *cr; /* * Try and ASSERT the minimum possible references on the * conn early enough. Since we are executing on write side, * the connection is obviously not detached and that means * there is a ref each for TCP and IP. Since we are behind * the squeue, the minimum references needed are 3. If the * conn is in classifier hash list, there should be an * extra ref for that (we check both the possibilities). */ ASSERT((connp->conn_fanout != NULL && connp->conn_ref >= 4) || (connp->conn_fanout == NULL && connp->conn_ref >= 3)); rptr = mp->b_rptr; ASSERT((uintptr_t)(mp->b_wptr - rptr) <= (uintptr_t)INT_MAX); if ((mp->b_wptr - rptr) >= sizeof (t_scalar_t)) { type = ((union T_primitives *)rptr)->type; if (type == T_EXDATA_REQ) { tcp_output_urgent(connp, mp, arg2, NULL); } else if (type != T_DATA_REQ) { goto non_urgent_data; } else { /* TODO: options, flags, ... from user */ /* Set length to zero for reclamation below */ tcp_wput_data(tcp, mp->b_cont, B_TRUE); freeb(mp); } return; } else { if (connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE, "tcp_wput_proto, dropping one..."); } freemsg(mp); return; } non_urgent_data: switch ((int)tprim->type) { case T_SSL_PROXY_BIND_REQ: /* an SSL proxy endpoint bind request */ /* * save the kssl_ent_t from the next block, and convert this * back to a normal bind_req. */ if (mp->b_cont != NULL) { ASSERT(MBLKL(mp->b_cont) >= sizeof (kssl_ent_t)); if (tcp->tcp_kssl_ent != NULL) { kssl_release_ent(tcp->tcp_kssl_ent, NULL, KSSL_NO_PROXY); tcp->tcp_kssl_ent = NULL; } bcopy(mp->b_cont->b_rptr, &tcp->tcp_kssl_ent, sizeof (kssl_ent_t)); kssl_hold_ent(tcp->tcp_kssl_ent); freemsg(mp->b_cont); mp->b_cont = NULL; } tprim->type = T_BIND_REQ; /* FALLTHROUGH */ case O_T_BIND_REQ: /* bind request */ case T_BIND_REQ: /* new semantics bind request */ tcp_tpi_bind(tcp, mp); break; case T_UNBIND_REQ: /* unbind request */ tcp_tpi_unbind(tcp, mp); break; case O_T_CONN_RES: /* old connection response XXX */ case T_CONN_RES: /* connection response */ tcp_tli_accept(tcp, mp); break; case T_CONN_REQ: /* connection request */ tcp_tpi_connect(tcp, mp); break; case T_DISCON_REQ: /* disconnect request */ tcp_disconnect(tcp, mp); break; case T_CAPABILITY_REQ: tcp_capability_req(tcp, mp); /* capability request */ break; case T_INFO_REQ: /* information request */ tcp_info_req(tcp, mp); break; case T_SVR4_OPTMGMT_REQ: /* manage options req */ case T_OPTMGMT_REQ: /* * Note: no support for snmpcom_req() through new * T_OPTMGMT_REQ. See comments in ip.c */ /* * All Solaris components should pass a db_credp * for this TPI message, hence we ASSERT. * But in case there is some other M_PROTO that looks * like a TPI message sent by some other kernel * component, we check and return an error. */ cr = msg_getcred(mp, NULL); ASSERT(cr != NULL); if (cr == NULL) { tcp_err_ack(tcp, mp, TSYSERR, EINVAL); return; } /* * If EINPROGRESS is returned, the request has been queued * for subsequent processing by ip_restart_optmgmt(), which * will do the CONN_DEC_REF(). */ if ((int)tprim->type == T_SVR4_OPTMGMT_REQ) { svr4_optcom_req(connp->conn_wq, mp, cr, &tcp_opt_obj); } else { tpi_optcom_req(connp->conn_wq, mp, cr, &tcp_opt_obj); } break; case T_UNITDATA_REQ: /* unitdata request */ tcp_err_ack(tcp, mp, TNOTSUPPORT, 0); break; case T_ORDREL_REQ: /* orderly release req */ freemsg(mp); if (tcp->tcp_fused) tcp_unfuse(tcp); if (tcp_xmit_end(tcp) != 0) { /* * We were crossing FINs and got a reset from * the other side. Just ignore it. */ if (connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE, "tcp_wput_proto, T_ORDREL_REQ out of " "state %s", tcp_display(tcp, NULL, DISP_ADDR_AND_PORT)); } } break; case T_ADDR_REQ: tcp_addr_req(tcp, mp); break; default: if (connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE, "tcp_wput_proto, bogus TPI msg, type %d", tprim->type); } /* * We used to M_ERROR. Sending TNOTSUPPORT gives the user * to recover. */ tcp_err_ack(tcp, mp, TNOTSUPPORT, 0); break; } } /* * Handle special out-of-band ioctl requests (see PSARC/2008/265). */ static void tcp_wput_cmdblk(queue_t *q, mblk_t *mp) { void *data; mblk_t *datamp = mp->b_cont; conn_t *connp = Q_TO_CONN(q); tcp_t *tcp = connp->conn_tcp; cmdblk_t *cmdp = (cmdblk_t *)mp->b_rptr; if (datamp == NULL || MBLKL(datamp) < cmdp->cb_len) { cmdp->cb_error = EPROTO; qreply(q, mp); return; } data = datamp->b_rptr; switch (cmdp->cb_cmd) { case TI_GETPEERNAME: if (tcp->tcp_state < TCPS_SYN_RCVD) cmdp->cb_error = ENOTCONN; else cmdp->cb_error = conn_getpeername(connp, data, &cmdp->cb_len); break; case TI_GETMYNAME: cmdp->cb_error = conn_getsockname(connp, data, &cmdp->cb_len); break; default: cmdp->cb_error = EINVAL; break; } qreply(q, mp); } /* * The TCP fast path write put procedure. * NOTE: the logic of the fast path is duplicated from tcp_wput_data() */ /* ARGSUSED */ void tcp_output(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { int len; int hdrlen; int plen; mblk_t *mp1; uchar_t *rptr; uint32_t snxt; tcpha_t *tcpha; struct datab *db; uint32_t suna; uint32_t mss; ipaddr_t *dst; ipaddr_t *src; uint32_t sum; int usable; conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; uint32_t msize; tcp_stack_t *tcps = tcp->tcp_tcps; ip_xmit_attr_t *ixa; clock_t now; /* * Try and ASSERT the minimum possible references on the * conn early enough. Since we are executing on write side, * the connection is obviously not detached and that means * there is a ref each for TCP and IP. Since we are behind * the squeue, the minimum references needed are 3. If the * conn is in classifier hash list, there should be an * extra ref for that (we check both the possibilities). */ ASSERT((connp->conn_fanout != NULL && connp->conn_ref >= 4) || (connp->conn_fanout == NULL && connp->conn_ref >= 3)); ASSERT(DB_TYPE(mp) == M_DATA); msize = (mp->b_cont == NULL) ? MBLKL(mp) : msgdsize(mp); mutex_enter(&tcp->tcp_non_sq_lock); tcp->tcp_squeue_bytes -= msize; mutex_exit(&tcp->tcp_non_sq_lock); /* Bypass tcp protocol for fused tcp loopback */ if (tcp->tcp_fused && tcp_fuse_output(tcp, mp, msize)) return; mss = tcp->tcp_mss; /* * If ZEROCOPY has turned off, try not to send any zero-copy message * down. Do backoff, now. */ if (tcp->tcp_snd_zcopy_aware && !tcp->tcp_snd_zcopy_on) mp = tcp_zcopy_backoff(tcp, mp, B_FALSE); ASSERT((uintptr_t)(mp->b_wptr - mp->b_rptr) <= (uintptr_t)INT_MAX); len = (int)(mp->b_wptr - mp->b_rptr); /* * Criteria for fast path: * * 1. no unsent data * 2. single mblk in request * 3. connection established * 4. data in mblk * 5. len <= mss * 6. no tcp_valid bits */ if ((tcp->tcp_unsent != 0) || (tcp->tcp_cork) || (mp->b_cont != NULL) || (tcp->tcp_state != TCPS_ESTABLISHED) || (len == 0) || (len > mss) || (tcp->tcp_valid_bits != 0)) { tcp_wput_data(tcp, mp, B_FALSE); return; } ASSERT(tcp->tcp_xmit_tail_unsent == 0); ASSERT(tcp->tcp_fin_sent == 0); /* queue new packet onto retransmission queue */ if (tcp->tcp_xmit_head == NULL) { tcp->tcp_xmit_head = mp; } else { tcp->tcp_xmit_last->b_cont = mp; } tcp->tcp_xmit_last = mp; tcp->tcp_xmit_tail = mp; /* find out how much we can send */ /* BEGIN CSTYLED */ /* * un-acked usable * |--------------|-----------------| * tcp_suna tcp_snxt tcp_suna+tcp_swnd */ /* END CSTYLED */ /* start sending from tcp_snxt */ snxt = tcp->tcp_snxt; /* * Check to see if this connection has been idled for some * time and no ACK is expected. If it is, we need to slow * start again to get back the connection's "self-clock" as * described in VJ's paper. * * Reinitialize tcp_cwnd after idle. */ now = LBOLT_FASTPATH; if ((tcp->tcp_suna == snxt) && !tcp->tcp_localnet && (TICK_TO_MSEC(now - tcp->tcp_last_recv_time) >= tcp->tcp_rto)) { TCP_SET_INIT_CWND(tcp, mss, tcps->tcps_slow_start_after_idle); } usable = tcp->tcp_swnd; /* tcp window size */ if (usable > tcp->tcp_cwnd) usable = tcp->tcp_cwnd; /* congestion window smaller */ usable -= snxt; /* subtract stuff already sent */ suna = tcp->tcp_suna; usable += suna; /* usable can be < 0 if the congestion window is smaller */ if (len > usable) { /* Can't send complete M_DATA in one shot */ goto slow; } mutex_enter(&tcp->tcp_non_sq_lock); if (tcp->tcp_flow_stopped && TCP_UNSENT_BYTES(tcp) <= connp->conn_sndlowat) { tcp_clrqfull(tcp); } mutex_exit(&tcp->tcp_non_sq_lock); /* * determine if anything to send (Nagle). * * 1. len < tcp_mss (i.e. small) * 2. unacknowledged data present * 3. len < nagle limit * 4. last packet sent < nagle limit (previous packet sent) */ if ((len < mss) && (snxt != suna) && (len < (int)tcp->tcp_naglim) && (tcp->tcp_last_sent_len < tcp->tcp_naglim)) { /* * This was the first unsent packet and normally * mss < xmit_hiwater so there is no need to worry * about flow control. The next packet will go * through the flow control check in tcp_wput_data(). */ /* leftover work from above */ tcp->tcp_unsent = len; tcp->tcp_xmit_tail_unsent = len; return; } /* * len <= tcp->tcp_mss && len == unsent so no sender silly window. Can * send now. */ if (snxt == suna) { TCP_TIMER_RESTART(tcp, tcp->tcp_rto); } /* we have always sent something */ tcp->tcp_rack_cnt = 0; tcp->tcp_snxt = snxt + len; tcp->tcp_rack = tcp->tcp_rnxt; if ((mp1 = dupb(mp)) == 0) goto no_memory; mp->b_prev = (mblk_t *)(uintptr_t)now; mp->b_next = (mblk_t *)(uintptr_t)snxt; /* adjust tcp header information */ tcpha = tcp->tcp_tcpha; tcpha->tha_flags = (TH_ACK|TH_PUSH); sum = len + connp->conn_ht_ulp_len + connp->conn_sum; sum = (sum >> 16) + (sum & 0xFFFF); tcpha->tha_sum = htons(sum); tcpha->tha_seq = htonl(snxt); TCPS_BUMP_MIB(tcps, tcpOutDataSegs); TCPS_UPDATE_MIB(tcps, tcpOutDataBytes, len); BUMP_LOCAL(tcp->tcp_obsegs); /* Update the latest receive window size in TCP header. */ tcpha->tha_win = htons(tcp->tcp_rwnd >> tcp->tcp_rcv_ws); tcp->tcp_last_sent_len = (ushort_t)len; plen = len + connp->conn_ht_iphc_len; ixa = connp->conn_ixa; ixa->ixa_pktlen = plen; if (ixa->ixa_flags & IXAF_IS_IPV4) { tcp->tcp_ipha->ipha_length = htons(plen); } else { tcp->tcp_ip6h->ip6_plen = htons(plen - IPV6_HDR_LEN); } /* see if we need to allocate a mblk for the headers */ hdrlen = connp->conn_ht_iphc_len; rptr = mp1->b_rptr - hdrlen; db = mp1->b_datap; if ((db->db_ref != 2) || rptr < db->db_base || (!OK_32PTR(rptr))) { /* NOTE: we assume allocb returns an OK_32PTR */ mp = allocb(hdrlen + tcps->tcps_wroff_xtra, BPRI_MED); if (!mp) { freemsg(mp1); goto no_memory; } mp->b_cont = mp1; mp1 = mp; /* Leave room for Link Level header */ rptr = &mp1->b_rptr[tcps->tcps_wroff_xtra]; mp1->b_wptr = &rptr[hdrlen]; } mp1->b_rptr = rptr; /* Fill in the timestamp option. */ if (tcp->tcp_snd_ts_ok) { uint32_t llbolt = (uint32_t)LBOLT_FASTPATH; U32_TO_BE32(llbolt, (char *)tcpha + TCP_MIN_HEADER_LENGTH+4); U32_TO_BE32(tcp->tcp_ts_recent, (char *)tcpha + TCP_MIN_HEADER_LENGTH+8); } else { ASSERT(connp->conn_ht_ulp_len == TCP_MIN_HEADER_LENGTH); } /* copy header into outgoing packet */ dst = (ipaddr_t *)rptr; src = (ipaddr_t *)connp->conn_ht_iphc; dst[0] = src[0]; dst[1] = src[1]; dst[2] = src[2]; dst[3] = src[3]; dst[4] = src[4]; dst[5] = src[5]; dst[6] = src[6]; dst[7] = src[7]; dst[8] = src[8]; dst[9] = src[9]; if (hdrlen -= 40) { hdrlen >>= 2; dst += 10; src += 10; do { *dst++ = *src++; } while (--hdrlen); } /* * Set the ECN info in the TCP header. Note that this * is not the template header. */ if (tcp->tcp_ecn_ok) { TCP_SET_ECT(tcp, rptr); tcpha = (tcpha_t *)(rptr + ixa->ixa_ip_hdr_length); if (tcp->tcp_ecn_echo_on) tcpha->tha_flags |= TH_ECE; if (tcp->tcp_cwr && !tcp->tcp_ecn_cwr_sent) { tcpha->tha_flags |= TH_CWR; tcp->tcp_ecn_cwr_sent = B_TRUE; } } if (tcp->tcp_ip_forward_progress) { tcp->tcp_ip_forward_progress = B_FALSE; connp->conn_ixa->ixa_flags |= IXAF_REACH_CONF; } else { connp->conn_ixa->ixa_flags &= ~IXAF_REACH_CONF; } tcp_send_data(tcp, mp1); return; /* * If we ran out of memory, we pretend to have sent the packet * and that it was lost on the wire. */ no_memory: return; slow: /* leftover work from above */ tcp->tcp_unsent = len; tcp->tcp_xmit_tail_unsent = len; tcp_wput_data(tcp, NULL, B_FALSE); } /* ARGSUSED2 */ void tcp_output_urgent(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { int len; uint32_t msize; conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; msize = msgdsize(mp); len = msize - 1; if (len < 0) { freemsg(mp); return; } /* * Try to force urgent data out on the wire. Even if we have unsent * data this will at least send the urgent flag. * XXX does not handle more flag correctly. */ len += tcp->tcp_unsent; len += tcp->tcp_snxt; tcp->tcp_urg = len; tcp->tcp_valid_bits |= TCP_URG_VALID; /* Bypass tcp protocol for fused tcp loopback */ if (tcp->tcp_fused && tcp_fuse_output(tcp, mp, msize)) return; /* Strip off the T_EXDATA_REQ if the data is from TPI */ if (DB_TYPE(mp) != M_DATA) { mblk_t *mp1 = mp; ASSERT(!IPCL_IS_NONSTR(connp)); mp = mp->b_cont; freeb(mp1); } tcp_wput_data(tcp, mp, B_TRUE); } /* * Called by streams close routine via squeues when our client blows off her * descriptor, we take this to mean: "close the stream state NOW, close the tcp * connection politely" When SO_LINGER is set (with a non-zero linger time and * it is not a nonblocking socket) then this routine sleeps until the FIN is * acked. * * NOTE: tcp_close potentially returns error when lingering. * However, the stream head currently does not pass these errors * to the application. 4.4BSD only returns EINTR and EWOULDBLOCK * errors to the application (from tsleep()) and not errors * like ECONNRESET caused by receiving a reset packet. */ /* ARGSUSED */ void tcp_close_output(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { char *msg; conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; clock_t delta = 0; tcp_stack_t *tcps = tcp->tcp_tcps; ASSERT((connp->conn_fanout != NULL && connp->conn_ref >= 4) || (connp->conn_fanout == NULL && connp->conn_ref >= 3)); mutex_enter(&tcp->tcp_eager_lock); if (tcp->tcp_conn_req_cnt_q0 != 0 || tcp->tcp_conn_req_cnt_q != 0) { /* Cleanup for listener */ tcp_eager_cleanup(tcp, 0); tcp->tcp_wait_for_eagers = 1; } mutex_exit(&tcp->tcp_eager_lock); tcp->tcp_lso = B_FALSE; msg = NULL; switch (tcp->tcp_state) { case TCPS_CLOSED: case TCPS_IDLE: case TCPS_BOUND: case TCPS_LISTEN: break; case TCPS_SYN_SENT: msg = "tcp_close, during connect"; break; case TCPS_SYN_RCVD: /* * Close during the connect 3-way handshake * but here there may or may not be pending data * already on queue. Process almost same as in * the ESTABLISHED state. */ /* FALLTHRU */ default: if (tcp->tcp_fused) tcp_unfuse(tcp); /* * If SO_LINGER has set a zero linger time, abort the * connection with a reset. */ if (connp->conn_linger && connp->conn_lingertime == 0) { msg = "tcp_close, zero lingertime"; break; } /* * Abort connection if there is unread data queued. */ if (tcp->tcp_rcv_list || tcp->tcp_reass_head) { msg = "tcp_close, unread data"; break; } /* * We have done a qwait() above which could have possibly * drained more messages in turn causing transition to a * different state. Check whether we have to do the rest * of the processing or not. */ if (tcp->tcp_state <= TCPS_LISTEN) break; /* * Transmit the FIN before detaching the tcp_t. * After tcp_detach returns this queue/perimeter * no longer owns the tcp_t thus others can modify it. */ (void) tcp_xmit_end(tcp); /* * If lingering on close then wait until the fin is acked, * the SO_LINGER time passes, or a reset is sent/received. */ if (connp->conn_linger && connp->conn_lingertime > 0 && !(tcp->tcp_fin_acked) && tcp->tcp_state >= TCPS_ESTABLISHED) { if (tcp->tcp_closeflags & (FNDELAY|FNONBLOCK)) { tcp->tcp_client_errno = EWOULDBLOCK; } else if (tcp->tcp_client_errno == 0) { ASSERT(tcp->tcp_linger_tid == 0); /* conn_lingertime is in sec. */ tcp->tcp_linger_tid = TCP_TIMER(tcp, tcp_close_linger_timeout, connp->conn_lingertime * MILLISEC); /* tcp_close_linger_timeout will finish close */ if (tcp->tcp_linger_tid == 0) tcp->tcp_client_errno = ENOSR; else return; } /* * Check if we need to detach or just close * the instance. */ if (tcp->tcp_state <= TCPS_LISTEN) break; } /* * Make sure that no other thread will access the conn_rq of * this instance (through lookups etc.) as conn_rq will go * away shortly. */ tcp_acceptor_hash_remove(tcp); mutex_enter(&tcp->tcp_non_sq_lock); if (tcp->tcp_flow_stopped) { tcp_clrqfull(tcp); } mutex_exit(&tcp->tcp_non_sq_lock); if (tcp->tcp_timer_tid != 0) { delta = TCP_TIMER_CANCEL(tcp, tcp->tcp_timer_tid); tcp->tcp_timer_tid = 0; } /* * Need to cancel those timers which will not be used when * TCP is detached. This has to be done before the conn_wq * is set to NULL. */ tcp_timers_stop(tcp); tcp->tcp_detached = B_TRUE; if (tcp->tcp_state == TCPS_TIME_WAIT) { tcp_time_wait_append(tcp); TCP_DBGSTAT(tcps, tcp_detach_time_wait); ASSERT(connp->conn_ref >= 3); goto finish; } /* * If delta is zero the timer event wasn't executed and was * successfully canceled. In this case we need to restart it * with the minimal delta possible. */ if (delta >= 0) tcp->tcp_timer_tid = TCP_TIMER(tcp, tcp_timer, delta ? delta : 1); ASSERT(connp->conn_ref >= 3); goto finish; } /* Detach did not complete. Still need to remove q from stream. */ if (msg) { if (tcp->tcp_state == TCPS_ESTABLISHED || tcp->tcp_state == TCPS_CLOSE_WAIT) TCPS_BUMP_MIB(tcps, tcpEstabResets); if (tcp->tcp_state == TCPS_SYN_SENT || tcp->tcp_state == TCPS_SYN_RCVD) TCPS_BUMP_MIB(tcps, tcpAttemptFails); tcp_xmit_ctl(msg, tcp, tcp->tcp_snxt, 0, TH_RST); } tcp_closei_local(tcp); CONN_DEC_REF(connp); ASSERT(connp->conn_ref >= 2); finish: mutex_enter(&tcp->tcp_closelock); /* * Don't change the queues in the case of a listener that has * eagers in its q or q0. It could surprise the eagers. * Instead wait for the eagers outside the squeue. */ if (!tcp->tcp_wait_for_eagers) { tcp->tcp_detached = B_TRUE; connp->conn_rq = NULL; connp->conn_wq = NULL; } /* Signal tcp_close() to finish closing. */ tcp->tcp_closed = 1; cv_signal(&tcp->tcp_closecv); mutex_exit(&tcp->tcp_closelock); } /* ARGSUSED */ void tcp_shutdown_output(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { conn_t *connp = (conn_t *)arg; tcp_t *tcp = connp->conn_tcp; freemsg(mp); if (tcp->tcp_fused) tcp_unfuse(tcp); if (tcp_xmit_end(tcp) != 0) { /* * We were crossing FINs and got a reset from * the other side. Just ignore it. */ if (connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_ERROR|SL_TRACE, "tcp_shutdown_output() out of state %s", tcp_display(tcp, NULL, DISP_ADDR_AND_PORT)); } } } #pragma inline(tcp_send_data) void tcp_send_data(tcp_t *tcp, mblk_t *mp) { conn_t *connp = tcp->tcp_connp; /* * Check here to avoid sending zero-copy message down to IP when * ZEROCOPY capability has turned off. We only need to deal with * the race condition between sockfs and the notification here. * Since we have tried to backoff the tcp_xmit_head when turning * zero-copy off and new messages in tcp_output(), we simply drop * the dup'ed packet here and let tcp retransmit, if tcp_xmit_zc_clean * is not true. */ if (tcp->tcp_snd_zcopy_aware && !tcp->tcp_snd_zcopy_on && !tcp->tcp_xmit_zc_clean) { ip_drop_output("TCP ZC was disabled but not clean", mp, NULL); freemsg(mp); return; } ASSERT(connp->conn_ixa->ixa_notify_cookie == connp->conn_tcp); (void) conn_ip_output(mp, connp->conn_ixa); } /* ARGSUSED2 */ void tcp_send_synack(void *arg, mblk_t *mp, void *arg2, ip_recv_attr_t *dummy) { conn_t *econnp = (conn_t *)arg; tcp_t *tcp = econnp->conn_tcp; /* Guard against a RST having blown it away while on the squeue */ if (tcp->tcp_state == TCPS_CLOSED) { freemsg(mp); return; } (void) conn_ip_output(mp, econnp->conn_ixa); } /* * tcp_send() is called by tcp_wput_data() and returns one of the following: * * -1 = failed allocation. * 0 = success; burst count reached, or usable send window is too small, * and that we'd rather wait until later before sending again. */ static int tcp_send(tcp_t *tcp, const int mss, const int total_hdr_len, const int tcp_hdr_len, const int num_sack_blk, int *usable, uint_t *snxt, int *tail_unsent, mblk_t **xmit_tail, mblk_t *local_time) { int num_burst_seg = tcp->tcp_snd_burst; int num_lso_seg = 1; uint_t lso_usable; boolean_t do_lso_send = B_FALSE; tcp_stack_t *tcps = tcp->tcp_tcps; conn_t *connp = tcp->tcp_connp; ip_xmit_attr_t *ixa = connp->conn_ixa; /* * Check LSO possibility. The value of tcp->tcp_lso indicates whether * the underlying connection is LSO capable. Will check whether having * enough available data to initiate LSO transmission in the for(){} * loops. */ if (tcp->tcp_lso && (tcp->tcp_valid_bits & ~TCP_FSS_VALID) == 0) do_lso_send = B_TRUE; for (;;) { struct datab *db; tcpha_t *tcpha; uint32_t sum; mblk_t *mp, *mp1; uchar_t *rptr; int len; /* * Burst count reached, return successfully. */ if (num_burst_seg == 0) break; /* * Calculate the maximum payload length we can send at one * time. */ if (do_lso_send) { /* * Check whether be able to to do LSO for the current * available data. */ if (num_burst_seg >= 2 && (*usable - 1) / mss >= 1) { lso_usable = MIN(tcp->tcp_lso_max, *usable); lso_usable = MIN(lso_usable, num_burst_seg * mss); num_lso_seg = lso_usable / mss; if (lso_usable % mss) { num_lso_seg++; tcp->tcp_last_sent_len = (ushort_t) (lso_usable % mss); } else { tcp->tcp_last_sent_len = (ushort_t)mss; } } else { do_lso_send = B_FALSE; num_lso_seg = 1; lso_usable = mss; } } ASSERT(num_lso_seg <= IP_MAXPACKET / mss + 1); #ifdef DEBUG DTRACE_PROBE2(tcp_send_lso, int, num_lso_seg, boolean_t, do_lso_send); #endif /* * Adjust num_burst_seg here. */ num_burst_seg -= num_lso_seg; len = mss; if (len > *usable) { ASSERT(do_lso_send == B_FALSE); len = *usable; if (len <= 0) { /* Terminate the loop */ break; /* success; too small */ } /* * Sender silly-window avoidance. * Ignore this if we are going to send a * zero window probe out. * * TODO: force data into microscopic window? * ==> (!pushed || (unsent > usable)) */ if (len < (tcp->tcp_max_swnd >> 1) && (tcp->tcp_unsent - (*snxt - tcp->tcp_snxt)) > len && !((tcp->tcp_valid_bits & TCP_URG_VALID) && len == 1) && (! tcp->tcp_zero_win_probe)) { /* * If the retransmit timer is not running * we start it so that we will retransmit * in the case when the receiver has * decremented the window. */ if (*snxt == tcp->tcp_snxt && *snxt == tcp->tcp_suna) { /* * We are not supposed to send * anything. So let's wait a little * bit longer before breaking SWS * avoidance. * * What should the value be? * Suggestion: MAX(init rexmit time, * tcp->tcp_rto) */ TCP_TIMER_RESTART(tcp, tcp->tcp_rto); } break; /* success; too small */ } } tcpha = tcp->tcp_tcpha; /* * The reason to adjust len here is that we need to set flags * and calculate checksum. */ if (do_lso_send) len = lso_usable; *usable -= len; /* Approximate - can be adjusted later */ if (*usable > 0) tcpha->tha_flags = TH_ACK; else tcpha->tha_flags = (TH_ACK | TH_PUSH); /* * Prime pump for IP's checksumming on our behalf. * Include the adjustment for a source route if any. * In case of LSO, the partial pseudo-header checksum should * exclusive TCP length, so zero tha_sum before IP calculate * pseudo-header checksum for partial checksum offload. */ if (do_lso_send) { sum = 0; } else { sum = len + tcp_hdr_len + connp->conn_sum; sum = (sum >> 16) + (sum & 0xFFFF); } tcpha->tha_sum = htons(sum); tcpha->tha_seq = htonl(*snxt); /* * Branch off to tcp_xmit_mp() if any of the VALID bits is * set. For the case when TCP_FSS_VALID is the only valid * bit (normal active close), branch off only when we think * that the FIN flag needs to be set. Note for this case, * that (snxt + len) may not reflect the actual seg_len, * as len may be further reduced in tcp_xmit_mp(). If len * gets modified, we will end up here again. */ if (tcp->tcp_valid_bits != 0 && (tcp->tcp_valid_bits != TCP_FSS_VALID || ((*snxt + len) == tcp->tcp_fss))) { uchar_t *prev_rptr; uint32_t prev_snxt = tcp->tcp_snxt; if (*tail_unsent == 0) { ASSERT((*xmit_tail)->b_cont != NULL); *xmit_tail = (*xmit_tail)->b_cont; prev_rptr = (*xmit_tail)->b_rptr; *tail_unsent = (int)((*xmit_tail)->b_wptr - (*xmit_tail)->b_rptr); } else { prev_rptr = (*xmit_tail)->b_rptr; (*xmit_tail)->b_rptr = (*xmit_tail)->b_wptr - *tail_unsent; } mp = tcp_xmit_mp(tcp, *xmit_tail, len, NULL, NULL, *snxt, B_FALSE, (uint32_t *)&len, B_FALSE); /* Restore tcp_snxt so we get amount sent right. */ tcp->tcp_snxt = prev_snxt; if (prev_rptr == (*xmit_tail)->b_rptr) { /* * If the previous timestamp is still in use, * don't stomp on it. */ if ((*xmit_tail)->b_next == NULL) { (*xmit_tail)->b_prev = local_time; (*xmit_tail)->b_next = (mblk_t *)(uintptr_t)(*snxt); } } else (*xmit_tail)->b_rptr = prev_rptr; if (mp == NULL) { return (-1); } mp1 = mp->b_cont; if (len <= mss) /* LSO is unusable (!do_lso_send) */ tcp->tcp_last_sent_len = (ushort_t)len; while (mp1->b_cont) { *xmit_tail = (*xmit_tail)->b_cont; (*xmit_tail)->b_prev = local_time; (*xmit_tail)->b_next = (mblk_t *)(uintptr_t)(*snxt); mp1 = mp1->b_cont; } *snxt += len; *tail_unsent = (*xmit_tail)->b_wptr - mp1->b_wptr; BUMP_LOCAL(tcp->tcp_obsegs); TCPS_BUMP_MIB(tcps, tcpOutDataSegs); TCPS_UPDATE_MIB(tcps, tcpOutDataBytes, len); tcp_send_data(tcp, mp); continue; } *snxt += len; /* Adjust later if we don't send all of len */ TCPS_BUMP_MIB(tcps, tcpOutDataSegs); TCPS_UPDATE_MIB(tcps, tcpOutDataBytes, len); if (*tail_unsent) { /* Are the bytes above us in flight? */ rptr = (*xmit_tail)->b_wptr - *tail_unsent; if (rptr != (*xmit_tail)->b_rptr) { *tail_unsent -= len; if (len <= mss) /* LSO is unusable */ tcp->tcp_last_sent_len = (ushort_t)len; len += total_hdr_len; ixa->ixa_pktlen = len; if (ixa->ixa_flags & IXAF_IS_IPV4) { tcp->tcp_ipha->ipha_length = htons(len); } else { tcp->tcp_ip6h->ip6_plen = htons(len - IPV6_HDR_LEN); } mp = dupb(*xmit_tail); if (mp == NULL) { return (-1); /* out_of_mem */ } mp->b_rptr = rptr; /* * If the old timestamp is no longer in use, * sample a new timestamp now. */ if ((*xmit_tail)->b_next == NULL) { (*xmit_tail)->b_prev = local_time; (*xmit_tail)->b_next = (mblk_t *)(uintptr_t)(*snxt-len); } goto must_alloc; } } else { *xmit_tail = (*xmit_tail)->b_cont; ASSERT((uintptr_t)((*xmit_tail)->b_wptr - (*xmit_tail)->b_rptr) <= (uintptr_t)INT_MAX); *tail_unsent = (int)((*xmit_tail)->b_wptr - (*xmit_tail)->b_rptr); } (*xmit_tail)->b_prev = local_time; (*xmit_tail)->b_next = (mblk_t *)(uintptr_t)(*snxt - len); *tail_unsent -= len; if (len <= mss) /* LSO is unusable (!do_lso_send) */ tcp->tcp_last_sent_len = (ushort_t)len; len += total_hdr_len; ixa->ixa_pktlen = len; if (ixa->ixa_flags & IXAF_IS_IPV4) { tcp->tcp_ipha->ipha_length = htons(len); } else { tcp->tcp_ip6h->ip6_plen = htons(len - IPV6_HDR_LEN); } mp = dupb(*xmit_tail); if (mp == NULL) { return (-1); /* out_of_mem */ } len = total_hdr_len; /* * There are four reasons to allocate a new hdr mblk: * 1) The bytes above us are in use by another packet * 2) We don't have good alignment * 3) The mblk is being shared * 4) We don't have enough room for a header */ rptr = mp->b_rptr - len; if (!OK_32PTR(rptr) || ((db = mp->b_datap), db->db_ref != 2) || rptr < db->db_base) { /* NOTE: we assume allocb returns an OK_32PTR */ must_alloc:; mp1 = allocb(connp->conn_ht_iphc_allocated + tcps->tcps_wroff_xtra, BPRI_MED); if (mp1 == NULL) { freemsg(mp); return (-1); /* out_of_mem */ } mp1->b_cont = mp; mp = mp1; /* Leave room for Link Level header */ len = total_hdr_len; rptr = &mp->b_rptr[tcps->tcps_wroff_xtra]; mp->b_wptr = &rptr[len]; } /* * Fill in the header using the template header, and add * options such as time-stamp, ECN and/or SACK, as needed. */ tcp_fill_header(tcp, rptr, (clock_t)local_time, num_sack_blk); mp->b_rptr = rptr; if (*tail_unsent) { int spill = *tail_unsent; mp1 = mp->b_cont; if (mp1 == NULL) mp1 = mp; /* * If we're a little short, tack on more mblks until * there is no more spillover. */ while (spill < 0) { mblk_t *nmp; int nmpsz; nmp = (*xmit_tail)->b_cont; nmpsz = MBLKL(nmp); /* * Excess data in mblk; can we split it? * If LSO is enabled for the connection, * keep on splitting as this is a transient * send path. */ if (!do_lso_send && (spill + nmpsz > 0)) { /* * Don't split if stream head was * told to break up larger writes * into smaller ones. */ if (tcp->tcp_maxpsz_multiplier > 0) break; /* * Next mblk is less than SMSS/2 * rounded up to nearest 64-byte; * let it get sent as part of the * next segment. */ if (tcp->tcp_localnet && !tcp->tcp_cork && (nmpsz < roundup((mss >> 1), 64))) break; } *xmit_tail = nmp; ASSERT((uintptr_t)nmpsz <= (uintptr_t)INT_MAX); /* Stash for rtt use later */ (*xmit_tail)->b_prev = local_time; (*xmit_tail)->b_next = (mblk_t *)(uintptr_t)(*snxt - len); mp1->b_cont = dupb(*xmit_tail); mp1 = mp1->b_cont; spill += nmpsz; if (mp1 == NULL) { *tail_unsent = spill; freemsg(mp); return (-1); /* out_of_mem */ } } /* Trim back any surplus on the last mblk */ if (spill >= 0) { mp1->b_wptr -= spill; *tail_unsent = spill; } else { /* * We did not send everything we could in * order to remain within the b_cont limit. */ *usable -= spill; *snxt += spill; tcp->tcp_last_sent_len += spill; TCPS_UPDATE_MIB(tcps, tcpOutDataBytes, spill); /* * Adjust the checksum */ tcpha = (tcpha_t *)(rptr + ixa->ixa_ip_hdr_length); sum += spill; sum = (sum >> 16) + (sum & 0xFFFF); tcpha->tha_sum = htons(sum); if (connp->conn_ipversion == IPV4_VERSION) { sum = ntohs( ((ipha_t *)rptr)->ipha_length) + spill; ((ipha_t *)rptr)->ipha_length = htons(sum); } else { sum = ntohs( ((ip6_t *)rptr)->ip6_plen) + spill; ((ip6_t *)rptr)->ip6_plen = htons(sum); } ixa->ixa_pktlen += spill; *tail_unsent = 0; } } if (tcp->tcp_ip_forward_progress) { tcp->tcp_ip_forward_progress = B_FALSE; ixa->ixa_flags |= IXAF_REACH_CONF; } else { ixa->ixa_flags &= ~IXAF_REACH_CONF; } if (do_lso_send) { /* Append LSO information to the mp. */ lso_info_set(mp, mss, HW_LSO); ixa->ixa_fragsize = IP_MAXPACKET; ixa->ixa_extra_ident = num_lso_seg - 1; DTRACE_PROBE2(tcp_send_lso, int, num_lso_seg, boolean_t, B_TRUE); tcp_send_data(tcp, mp); /* * Restore values of ixa_fragsize and ixa_extra_ident. */ ixa->ixa_fragsize = ixa->ixa_pmtu; ixa->ixa_extra_ident = 0; tcp->tcp_obsegs += num_lso_seg; TCP_STAT(tcps, tcp_lso_times); TCP_STAT_UPDATE(tcps, tcp_lso_pkt_out, num_lso_seg); } else { /* * Make sure to clean up LSO information. Wherever a * new mp uses the prepended header room after dupb(), * lso_info_cleanup() should be called. */ lso_info_cleanup(mp); tcp_send_data(tcp, mp); BUMP_LOCAL(tcp->tcp_obsegs); } } return (0); } /* * Initiate closedown sequence on an active connection. (May be called as * writer.) Return value zero for OK return, non-zero for error return. */ static int tcp_xmit_end(tcp_t *tcp) { mblk_t *mp; tcp_stack_t *tcps = tcp->tcp_tcps; iulp_t uinfo; ip_stack_t *ipst = tcps->tcps_netstack->netstack_ip; conn_t *connp = tcp->tcp_connp; if (tcp->tcp_state < TCPS_SYN_RCVD || tcp->tcp_state > TCPS_CLOSE_WAIT) { /* * Invalid state, only states TCPS_SYN_RCVD, * TCPS_ESTABLISHED and TCPS_CLOSE_WAIT are valid */ return (-1); } tcp->tcp_fss = tcp->tcp_snxt + tcp->tcp_unsent; tcp->tcp_valid_bits |= TCP_FSS_VALID; /* * If there is nothing more unsent, send the FIN now. * Otherwise, it will go out with the last segment. */ if (tcp->tcp_unsent == 0) { mp = tcp_xmit_mp(tcp, NULL, 0, NULL, NULL, tcp->tcp_fss, B_FALSE, NULL, B_FALSE); if (mp) { tcp_send_data(tcp, mp); } else { /* * Couldn't allocate msg. Pretend we got it out. * Wait for rexmit timeout. */ tcp->tcp_snxt = tcp->tcp_fss + 1; TCP_TIMER_RESTART(tcp, tcp->tcp_rto); } /* * If needed, update tcp_rexmit_snxt as tcp_snxt is * changed. */ if (tcp->tcp_rexmit && tcp->tcp_rexmit_nxt == tcp->tcp_fss) { tcp->tcp_rexmit_nxt = tcp->tcp_snxt; } } else { /* * If tcp->tcp_cork is set, then the data will not get sent, * so we have to check that and unset it first. */ if (tcp->tcp_cork) tcp->tcp_cork = B_FALSE; tcp_wput_data(tcp, NULL, B_FALSE); } /* * If TCP does not get enough samples of RTT or tcp_rtt_updates * is 0, don't update the cache. */ if (tcps->tcps_rtt_updates == 0 || tcp->tcp_rtt_update < tcps->tcps_rtt_updates) return (0); /* * We do not have a good algorithm to update ssthresh at this time. * So don't do any update. */ bzero(&uinfo, sizeof (uinfo)); uinfo.iulp_rtt = tcp->tcp_rtt_sa; uinfo.iulp_rtt_sd = tcp->tcp_rtt_sd; /* * Note that uinfo is kept for conn_faddr in the DCE. Could update even * if source routed but we don't. */ if (connp->conn_ipversion == IPV4_VERSION) { if (connp->conn_faddr_v4 != tcp->tcp_ipha->ipha_dst) { return (0); } (void) dce_update_uinfo_v4(connp->conn_faddr_v4, &uinfo, ipst); } else { uint_t ifindex; if (!(IN6_ARE_ADDR_EQUAL(&connp->conn_faddr_v6, &tcp->tcp_ip6h->ip6_dst))) { return (0); } ifindex = 0; if (IN6_IS_ADDR_LINKSCOPE(&connp->conn_faddr_v6)) { ip_xmit_attr_t *ixa = connp->conn_ixa; /* * If we are going to create a DCE we'd better have * an ifindex */ if (ixa->ixa_nce != NULL) { ifindex = ixa->ixa_nce->nce_common->ncec_ill-> ill_phyint->phyint_ifindex; } else { return (0); } } (void) dce_update_uinfo(&connp->conn_faddr_v6, ifindex, &uinfo, ipst); } return (0); } /* * Send out a control packet on the tcp connection specified. This routine * is typically called where we need a simple ACK or RST generated. */ void tcp_xmit_ctl(char *str, tcp_t *tcp, uint32_t seq, uint32_t ack, int ctl) { uchar_t *rptr; tcpha_t *tcpha; ipha_t *ipha = NULL; ip6_t *ip6h = NULL; uint32_t sum; int total_hdr_len; int ip_hdr_len; mblk_t *mp; tcp_stack_t *tcps = tcp->tcp_tcps; conn_t *connp = tcp->tcp_connp; ip_xmit_attr_t *ixa = connp->conn_ixa; /* * Save sum for use in source route later. */ sum = connp->conn_ht_ulp_len + connp->conn_sum; total_hdr_len = connp->conn_ht_iphc_len; ip_hdr_len = ixa->ixa_ip_hdr_length; /* If a text string is passed in with the request, pass it to strlog. */ if (str != NULL && connp->conn_debug) { (void) strlog(TCP_MOD_ID, 0, 1, SL_TRACE, "tcp_xmit_ctl: '%s', seq 0x%x, ack 0x%x, ctl 0x%x", str, seq, ack, ctl); } mp = allocb(connp->conn_ht_iphc_allocated + tcps->tcps_wroff_xtra, BPRI_MED); if (mp == NULL) { return; } rptr = &mp->b_rptr[tcps->tcps_wroff_xtra]; mp->b_rptr = rptr; mp->b_wptr = &rptr[total_hdr_len]; bcopy(connp->conn_ht_iphc, rptr, total_hdr_len); ixa->ixa_pktlen = total_hdr_len; if (ixa->ixa_flags & IXAF_IS_IPV4) { ipha = (ipha_t *)rptr; ipha->ipha_length = htons(total_hdr_len); } else { ip6h = (ip6_t *)rptr; ip6h->ip6_plen = htons(total_hdr_len - IPV6_HDR_LEN); } tcpha = (tcpha_t *)&rptr[ip_hdr_len]; tcpha->tha_flags = (uint8_t)ctl; if (ctl & TH_RST) { TCPS_BUMP_MIB(tcps, tcpOutRsts); TCPS_BUMP_MIB(tcps, tcpOutControl); /* * Don't send TSopt w/ TH_RST packets per RFC 1323. */ if (tcp->tcp_snd_ts_ok && tcp->tcp_state > TCPS_SYN_SENT) { mp->b_wptr = &rptr[total_hdr_len - TCPOPT_REAL_TS_LEN]; *(mp->b_wptr) = TCPOPT_EOL; ixa->ixa_pktlen = total_hdr_len - TCPOPT_REAL_TS_LEN; if (connp->conn_ipversion == IPV4_VERSION) { ipha->ipha_length = htons(total_hdr_len - TCPOPT_REAL_TS_LEN); } else { ip6h->ip6_plen = htons(total_hdr_len - IPV6_HDR_LEN - TCPOPT_REAL_TS_LEN); } tcpha->tha_offset_and_reserved -= (3 << 4); sum -= TCPOPT_REAL_TS_LEN; } } if (ctl & TH_ACK) { if (tcp->tcp_snd_ts_ok) { uint32_t llbolt = (uint32_t)LBOLT_FASTPATH; U32_TO_BE32(llbolt, (char *)tcpha + TCP_MIN_HEADER_LENGTH+4); U32_TO_BE32(tcp->tcp_ts_recent, (char *)tcpha + TCP_MIN_HEADER_LENGTH+8); } /* Update the latest receive window size in TCP header. */ tcpha->tha_win = htons(tcp->tcp_rwnd >> tcp->tcp_rcv_ws); /* Track what we sent to the peer */ tcp->tcp_tcpha->tha_win = tcpha->tha_win; tcp->tcp_rack = ack; tcp->tcp_rack_cnt = 0; TCPS_BUMP_MIB(tcps, tcpOutAck); } BUMP_LOCAL(tcp->tcp_obsegs); tcpha->tha_seq = htonl(seq); tcpha->tha_ack = htonl(ack); /* * Include the adjustment for a source route if any. */ sum = (sum >> 16) + (sum & 0xFFFF); tcpha->tha_sum = htons(sum); tcp_send_data(tcp, mp); } /* * Generate a reset based on an inbound packet, connp is set by caller * when RST is in response to an unexpected inbound packet for which * there is active tcp state in the system. * * IPSEC NOTE : Try to send the reply with the same protection as it came * in. We have the ip_recv_attr_t which is reversed to form the ip_xmit_attr_t. * That way the packet will go out at the same level of protection as it * came in with. */ static void tcp_xmit_early_reset(char *str, mblk_t *mp, uint32_t seq, uint32_t ack, int ctl, ip_recv_attr_t *ira, ip_stack_t *ipst, conn_t *connp) { ipha_t *ipha = NULL; ip6_t *ip6h = NULL; ushort_t len; tcpha_t *tcpha; int i; ipaddr_t v4addr; in6_addr_t v6addr; netstack_t *ns = ipst->ips_netstack; tcp_stack_t *tcps = ns->netstack_tcp; ip_xmit_attr_t ixas, *ixa; uint_t ip_hdr_len = ira->ira_ip_hdr_length; boolean_t need_refrele = B_FALSE; /* ixa_refrele(ixa) */ ushort_t port; if (!tcp_send_rst_chk(tcps)) { TCP_STAT(tcps, tcp_rst_unsent); freemsg(mp); return; } /* * If connp != NULL we use conn_ixa to keep IP_NEXTHOP and other * options from the listener. In that case the caller must ensure that * we are running on the listener = connp squeue. * * We get a safe copy of conn_ixa so we don't need to restore anything * we or ip_output_simple might change in the ixa. */ if (connp != NULL) { ASSERT(connp->conn_on_sqp); ixa = conn_get_ixa_exclusive(connp); if (ixa == NULL) { TCP_STAT(tcps, tcp_rst_unsent); freemsg(mp); return; } need_refrele = B_TRUE; } else { bzero(&ixas, sizeof (ixas)); ixa = &ixas; /* * IXAF_VERIFY_SOURCE is overkill since we know the * packet was for us. */ ixa->ixa_flags |= IXAF_SET_ULP_CKSUM | IXAF_VERIFY_SOURCE; ixa->ixa_protocol = IPPROTO_TCP; ixa->ixa_zoneid = ira->ira_zoneid; ixa->ixa_ifindex = 0; ixa->ixa_ipst = ipst; ixa->ixa_cred = kcred; ixa->ixa_cpid = NOPID; } if (str && tcps->tcps_dbg) { (void) strlog(TCP_MOD_ID, 0, 1, SL_TRACE, "tcp_xmit_early_reset: '%s', seq 0x%x, ack 0x%x, " "flags 0x%x", str, seq, ack, ctl); } if (mp->b_datap->db_ref != 1) { mblk_t *mp1 = copyb(mp); freemsg(mp); mp = mp1; if (mp == NULL) goto done; } else if (mp->b_cont) { freemsg(mp->b_cont); mp->b_cont = NULL; DB_CKSUMFLAGS(mp) = 0; } /* * We skip reversing source route here. * (for now we replace all IP options with EOL) */ if (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION) { ipha = (ipha_t *)mp->b_rptr; for (i = IP_SIMPLE_HDR_LENGTH; i < (int)ip_hdr_len; i++) mp->b_rptr[i] = IPOPT_EOL; /* * Make sure that src address isn't flagrantly invalid. * Not all broadcast address checking for the src address * is possible, since we don't know the netmask of the src * addr. No check for destination address is done, since * IP will not pass up a packet with a broadcast dest * address to TCP. Similar checks are done below for IPv6. */ if (ipha->ipha_src == 0 || ipha->ipha_src == INADDR_BROADCAST || CLASSD(ipha->ipha_src)) { BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsInDiscards); ip_drop_input("ipIfStatsInDiscards", mp, NULL); freemsg(mp); goto done; } } else { ip6h = (ip6_t *)mp->b_rptr; if (IN6_IS_ADDR_UNSPECIFIED(&ip6h->ip6_src) || IN6_IS_ADDR_MULTICAST(&ip6h->ip6_src)) { BUMP_MIB(&ipst->ips_ip6_mib, ipIfStatsInDiscards); ip_drop_input("ipIfStatsInDiscards", mp, NULL); freemsg(mp); goto done; } /* Remove any extension headers assuming partial overlay */ if (ip_hdr_len > IPV6_HDR_LEN) { uint8_t *to; to = mp->b_rptr + ip_hdr_len - IPV6_HDR_LEN; ovbcopy(ip6h, to, IPV6_HDR_LEN); mp->b_rptr += ip_hdr_len - IPV6_HDR_LEN; ip_hdr_len = IPV6_HDR_LEN; ip6h = (ip6_t *)mp->b_rptr; ip6h->ip6_nxt = IPPROTO_TCP; } } tcpha = (tcpha_t *)&mp->b_rptr[ip_hdr_len]; if (tcpha->tha_flags & TH_RST) { freemsg(mp); goto done; } tcpha->tha_offset_and_reserved = (5 << 4); len = ip_hdr_len + sizeof (tcpha_t); mp->b_wptr = &mp->b_rptr[len]; if (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION) { ipha->ipha_length = htons(len); /* Swap addresses */ v4addr = ipha->ipha_src; ipha->ipha_src = ipha->ipha_dst; ipha->ipha_dst = v4addr; ipha->ipha_ident = 0; ipha->ipha_ttl = (uchar_t)tcps->tcps_ipv4_ttl; ixa->ixa_flags |= IXAF_IS_IPV4; ixa->ixa_ip_hdr_length = ip_hdr_len; } else { ip6h->ip6_plen = htons(len - IPV6_HDR_LEN); /* Swap addresses */ v6addr = ip6h->ip6_src; ip6h->ip6_src = ip6h->ip6_dst; ip6h->ip6_dst = v6addr; ip6h->ip6_hops = (uchar_t)tcps->tcps_ipv6_hoplimit; ixa->ixa_flags &= ~IXAF_IS_IPV4; if (IN6_IS_ADDR_LINKSCOPE(&ip6h->ip6_dst)) { ixa->ixa_flags |= IXAF_SCOPEID_SET; ixa->ixa_scopeid = ira->ira_ruifindex; } ixa->ixa_ip_hdr_length = IPV6_HDR_LEN; } ixa->ixa_pktlen = len; /* Swap the ports */ port = tcpha->tha_fport; tcpha->tha_fport = tcpha->tha_lport; tcpha->tha_lport = port; tcpha->tha_ack = htonl(ack); tcpha->tha_seq = htonl(seq); tcpha->tha_win = 0; tcpha->tha_sum = htons(sizeof (tcpha_t)); tcpha->tha_flags = (uint8_t)ctl; if (ctl & TH_RST) { TCPS_BUMP_MIB(tcps, tcpOutRsts); TCPS_BUMP_MIB(tcps, tcpOutControl); } /* Discard any old label */ if (ixa->ixa_free_flags & IXA_FREE_TSL) { ASSERT(ixa->ixa_tsl != NULL); label_rele(ixa->ixa_tsl); ixa->ixa_free_flags &= ~IXA_FREE_TSL; } ixa->ixa_tsl = ira->ira_tsl; /* Behave as a multi-level responder */ if (ira->ira_flags & IRAF_IPSEC_SECURE) { /* * Apply IPsec based on how IPsec was applied to * the packet that caused the RST. */ if (!ipsec_in_to_out(ira, ixa, mp, ipha, ip6h)) { BUMP_MIB(&ipst->ips_ip_mib, ipIfStatsOutDiscards); /* Note: mp already consumed and ip_drop_packet done */ goto done; } } else { /* * This is in clear. The RST message we are building * here should go out in clear, independent of our policy. */ ixa->ixa_flags |= IXAF_NO_IPSEC; } /* * NOTE: one might consider tracing a TCP packet here, but * this function has no active TCP state and no tcp structure * that has a trace buffer. If we traced here, we would have * to keep a local trace buffer in tcp_record_trace(). */ (void) ip_output_simple(mp, ixa); done: ixa_cleanup(ixa); if (need_refrele) { ASSERT(ixa != &ixas); ixa_refrele(ixa); } } /* * Generate a "no listener here" RST in response to an "unknown" segment. * connp is set by caller when RST is in response to an unexpected * inbound packet for which there is active tcp state in the system. * Note that we are reusing the incoming mp to construct the outgoing RST. */ void tcp_xmit_listeners_reset(mblk_t *mp, ip_recv_attr_t *ira, ip_stack_t *ipst, conn_t *connp) { uchar_t *rptr; uint32_t seg_len; tcpha_t *tcpha; uint32_t seg_seq; uint32_t seg_ack; uint_t flags; ipha_t *ipha; ip6_t *ip6h; boolean_t policy_present; netstack_t *ns = ipst->ips_netstack; tcp_stack_t *tcps = ns->netstack_tcp; ipsec_stack_t *ipss = tcps->tcps_netstack->netstack_ipsec; uint_t ip_hdr_len = ira->ira_ip_hdr_length; TCP_STAT(tcps, tcp_no_listener); if (IPH_HDR_VERSION(mp->b_rptr) == IPV4_VERSION) { policy_present = ipss->ipsec_inbound_v4_policy_present; ipha = (ipha_t *)mp->b_rptr; ip6h = NULL; } else { policy_present = ipss->ipsec_inbound_v6_policy_present; ipha = NULL; ip6h = (ip6_t *)mp->b_rptr; } if (policy_present) { /* * The conn_t parameter is NULL because we already know * nobody's home. */ mp = ipsec_check_global_policy(mp, (conn_t *)NULL, ipha, ip6h, ira, ns); if (mp == NULL) return; } if (is_system_labeled() && !tsol_can_reply_error(mp, ira)) { DTRACE_PROBE2( tx__ip__log__error__nolistener__tcp, char *, "Could not reply with RST to mp(1)", mblk_t *, mp); ip2dbg(("tcp_xmit_listeners_reset: not permitted to reply\n")); freemsg(mp); return; } rptr = mp->b_rptr; tcpha = (tcpha_t *)&rptr[ip_hdr_len]; seg_seq = ntohl(tcpha->tha_seq); seg_ack = ntohl(tcpha->tha_ack); flags = tcpha->tha_flags; seg_len = msgdsize(mp) - (TCP_HDR_LENGTH(tcpha) + ip_hdr_len); if (flags & TH_RST) { freemsg(mp); } else if (flags & TH_ACK) { tcp_xmit_early_reset("no tcp, reset", mp, seg_ack, 0, TH_RST, ira, ipst, connp); } else { if (flags & TH_SYN) { seg_len++; } else { /* * Here we violate the RFC. Note that a normal * TCP will never send a segment without the ACK * flag, except for RST or SYN segment. This * segment is neither. Just drop it on the * floor. */ freemsg(mp); TCP_STAT(tcps, tcp_rst_unsent); return; } tcp_xmit_early_reset("no tcp, reset/ack", mp, 0, seg_seq + seg_len, TH_RST | TH_ACK, ira, ipst, connp); } } /* * tcp_xmit_mp is called to return a pointer to an mblk chain complete with * ip and tcp header ready to pass down to IP. If the mp passed in is * non-NULL, then up to max_to_send bytes of data will be dup'ed off that * mblk. (If sendall is not set the dup'ing will stop at an mblk boundary * otherwise it will dup partial mblks.) * Otherwise, an appropriate ACK packet will be generated. This * routine is not usually called to send new data for the first time. It * is mostly called out of the timer for retransmits, and to generate ACKs. * * If offset is not NULL, the returned mblk chain's first mblk's b_rptr will * be adjusted by *offset. And after dupb(), the offset and the ending mblk * of the original mblk chain will be returned in *offset and *end_mp. */ mblk_t * tcp_xmit_mp(tcp_t *tcp, mblk_t *mp, int32_t max_to_send, int32_t *offset, mblk_t **end_mp, uint32_t seq, boolean_t sendall, uint32_t *seg_len, boolean_t rexmit) { int data_length; int32_t off = 0; uint_t flags; mblk_t *mp1; mblk_t *mp2; uchar_t *rptr; tcpha_t *tcpha; int32_t num_sack_blk = 0; int32_t sack_opt_len = 0; tcp_stack_t *tcps = tcp->tcp_tcps; conn_t *connp = tcp->tcp_connp; ip_xmit_attr_t *ixa = connp->conn_ixa; /* Allocate for our maximum TCP header + link-level */ mp1 = allocb(connp->conn_ht_iphc_allocated + tcps->tcps_wroff_xtra, BPRI_MED); if (!mp1) return (NULL); data_length = 0; /* * Note that tcp_mss has been adjusted to take into account the * timestamp option if applicable. Because SACK options do not * appear in every TCP segments and they are of variable lengths, * they cannot be included in tcp_mss. Thus we need to calculate * the actual segment length when we need to send a segment which * includes SACK options. */ if (tcp->tcp_snd_sack_ok && tcp->tcp_num_sack_blk > 0) { num_sack_blk = MIN(tcp->tcp_max_sack_blk, tcp->tcp_num_sack_blk); sack_opt_len = num_sack_blk * sizeof (sack_blk_t) + TCPOPT_NOP_LEN * 2 + TCPOPT_HEADER_LEN; if (max_to_send + sack_opt_len > tcp->tcp_mss) max_to_send -= sack_opt_len; } if (offset != NULL) { off = *offset; /* We use offset as an indicator that end_mp is not NULL. */ *end_mp = NULL; } for (mp2 = mp1; mp && data_length != max_to_send; mp = mp->b_cont) { /* This could be faster with cooperation from downstream */ if (mp2 != mp1 && !sendall && data_length + (int)(mp->b_wptr - mp->b_rptr) > max_to_send) /* * Don't send the next mblk since the whole mblk * does not fit. */ break; mp2->b_cont = dupb(mp); mp2 = mp2->b_cont; if (!mp2) { freemsg(mp1); return (NULL); } mp2->b_rptr += off; ASSERT((uintptr_t)(mp2->b_wptr - mp2->b_rptr) <= (uintptr_t)INT_MAX); data_length += (int)(mp2->b_wptr - mp2->b_rptr); if (data_length > max_to_send) { mp2->b_wptr -= data_length - max_to_send; data_length = max_to_send; off = mp2->b_wptr - mp->b_rptr; break; } else { off = 0; } } if (offset != NULL) { *offset = off; *end_mp = mp; } if (seg_len != NULL) { *seg_len = data_length; } /* Update the latest receive window size in TCP header. */ tcp->tcp_tcpha->tha_win = htons(tcp->tcp_rwnd >> tcp->tcp_rcv_ws); rptr = mp1->b_rptr + tcps->tcps_wroff_xtra; mp1->b_rptr = rptr; mp1->b_wptr = rptr + connp->conn_ht_iphc_len + sack_opt_len; bcopy(connp->conn_ht_iphc, rptr, connp->conn_ht_iphc_len); tcpha = (tcpha_t *)&rptr[ixa->ixa_ip_hdr_length]; tcpha->tha_seq = htonl(seq); /* * Use tcp_unsent to determine if the PUSH bit should be used assumes * that this function was called from tcp_wput_data. Thus, when called * to retransmit data the setting of the PUSH bit may appear some * what random in that it might get set when it should not. This * should not pose any performance issues. */ if (data_length != 0 && (tcp->tcp_unsent == 0 || tcp->tcp_unsent == data_length)) { flags = TH_ACK | TH_PUSH; } else { flags = TH_ACK; } if (tcp->tcp_ecn_ok) { if (tcp->tcp_ecn_echo_on) flags |= TH_ECE; /* * Only set ECT bit and ECN_CWR if a segment contains new data. * There is no TCP flow control for non-data segments, and * only data segment is transmitted reliably. */ if (data_length > 0 && !rexmit) { TCP_SET_ECT(tcp, rptr); if (tcp->tcp_cwr && !tcp->tcp_ecn_cwr_sent) { flags |= TH_CWR; tcp->tcp_ecn_cwr_sent = B_TRUE; } } } if (tcp->tcp_valid_bits) { uint32_t u1; if ((tcp->tcp_valid_bits & TCP_ISS_VALID) && seq == tcp->tcp_iss) { uchar_t *wptr; /* * If TCP_ISS_VALID and the seq number is tcp_iss, * TCP can only be in SYN-SENT, SYN-RCVD or * FIN-WAIT-1 state. It can be FIN-WAIT-1 if * our SYN is not ack'ed but the app closes this * TCP connection. */ ASSERT(tcp->tcp_state == TCPS_SYN_SENT || tcp->tcp_state == TCPS_SYN_RCVD || tcp->tcp_state == TCPS_FIN_WAIT_1); /* * Tack on the MSS option. It is always needed * for both active and passive open. * * MSS option value should be interface MTU - MIN * TCP/IP header according to RFC 793 as it means * the maximum segment size TCP can receive. But * to get around some broken middle boxes/end hosts * out there, we allow the option value to be the * same as the MSS option size on the peer side. * In this way, the other side will not send * anything larger than they can receive. * * Note that for SYN_SENT state, the ndd param * tcp_use_smss_as_mss_opt has no effect as we * don't know the peer's MSS option value. So * the only case we need to take care of is in * SYN_RCVD state, which is done later. */ wptr = mp1->b_wptr; wptr[0] = TCPOPT_MAXSEG; wptr[1] = TCPOPT_MAXSEG_LEN; wptr += 2; u1 = tcp->tcp_initial_pmtu - (connp->conn_ipversion == IPV4_VERSION ? IP_SIMPLE_HDR_LENGTH : IPV6_HDR_LEN) - TCP_MIN_HEADER_LENGTH; U16_TO_BE16(u1, wptr); mp1->b_wptr = wptr + 2; /* Update the offset to cover the additional word */ tcpha->tha_offset_and_reserved += (1 << 4); /* * Note that the following way of filling in * TCP options are not optimal. Some NOPs can * be saved. But there is no need at this time * to optimize it. When it is needed, we will * do it. */ switch (tcp->tcp_state) { case TCPS_SYN_SENT: flags = TH_SYN; if (tcp->tcp_snd_ts_ok) { uint32_t llbolt = (uint32_t)LBOLT_FASTPATH; wptr = mp1->b_wptr; wptr[0] = TCPOPT_NOP; wptr[1] = TCPOPT_NOP; wptr[2] = TCPOPT_TSTAMP; wptr[3] = TCPOPT_TSTAMP_LEN; wptr += 4; U32_TO_BE32(llbolt, wptr); wptr += 4; ASSERT(tcp->tcp_ts_recent == 0); U32_TO_BE32(0L, wptr); mp1->b_wptr += TCPOPT_REAL_TS_LEN; tcpha->tha_offset_and_reserved += (3 << 4); } /* * Set up all the bits to tell other side * we are ECN capable. */ if (tcp->tcp_ecn_ok) { flags |= (TH_ECE | TH_CWR); } break; case TCPS_SYN_RCVD: flags |= TH_SYN; /* * Reset the MSS option value to be SMSS * We should probably add back the bytes * for timestamp option and IPsec. We * don't do that as this is a workaround * for broken middle boxes/end hosts, it * is better for us to be more cautious. * They may not take these things into * account in their SMSS calculation. Thus * the peer's calculated SMSS may be smaller * than what it can be. This should be OK. */ if (tcps->tcps_use_smss_as_mss_opt) { u1 = tcp->tcp_mss; U16_TO_BE16(u1, wptr); } /* * If the other side is ECN capable, reply * that we are also ECN capable. */ if (tcp->tcp_ecn_ok) flags |= TH_ECE; break; default: /* * The above ASSERT() makes sure that this * must be FIN-WAIT-1 state. Our SYN has * not been ack'ed so retransmit it. */ flags |= TH_SYN; break; } if (tcp->tcp_snd_ws_ok) { wptr = mp1->b_wptr; wptr[0] = TCPOPT_NOP; wptr[1] = TCPOPT_WSCALE; wptr[2] = TCPOPT_WS_LEN; wptr[3] = (uchar_t)tcp->tcp_rcv_ws; mp1->b_wptr += TCPOPT_REAL_WS_LEN; tcpha->tha_offset_and_reserved += (1 << 4); } if (tcp->tcp_snd_sack_ok) { wptr = mp1->b_wptr; wptr[0] = TCPOPT_NOP; wptr[1] = TCPOPT_NOP; wptr[2] = TCPOPT_SACK_PERMITTED; wptr[3] = TCPOPT_SACK_OK_LEN; mp1->b_wptr += TCPOPT_REAL_SACK_OK_LEN; tcpha->tha_offset_and_reserved += (1 << 4); } /* allocb() of adequate mblk assures space */ ASSERT((uintptr_t)(mp1->b_wptr - mp1->b_rptr) <= (uintptr_t)INT_MAX); u1 = (int)(mp1->b_wptr - mp1->b_rptr); /* * Get IP set to checksum on our behalf * Include the adjustment for a source route if any. */ u1 += connp->conn_sum; u1 = (u1 >> 16) + (u1 & 0xFFFF); tcpha->tha_sum = htons(u1); TCPS_BUMP_MIB(tcps, tcpOutControl); } if ((tcp->tcp_valid_bits & TCP_FSS_VALID) && (seq + data_length) == tcp->tcp_fss) { if (!tcp->tcp_fin_acked) { flags |= TH_FIN; TCPS_BUMP_MIB(tcps, tcpOutControl); } if (!tcp->tcp_fin_sent) { tcp->tcp_fin_sent = B_TRUE; switch (tcp->tcp_state) { case TCPS_SYN_RCVD: case TCPS_ESTABLISHED: tcp->tcp_state = TCPS_FIN_WAIT_1; break; case TCPS_CLOSE_WAIT: tcp->tcp_state = TCPS_LAST_ACK; break; } if (tcp->tcp_suna == tcp->tcp_snxt) TCP_TIMER_RESTART(tcp, tcp->tcp_rto); tcp->tcp_snxt = tcp->tcp_fss + 1; } } /* * Note the trick here. u1 is unsigned. When tcp_urg * is smaller than seq, u1 will become a very huge value. * So the comparison will fail. Also note that tcp_urp * should be positive, see RFC 793 page 17. */ u1 = tcp->tcp_urg - seq + TCP_OLD_URP_INTERPRETATION; if ((tcp->tcp_valid_bits & TCP_URG_VALID) && u1 != 0 && u1 < (uint32_t)(64 * 1024)) { flags |= TH_URG; TCPS_BUMP_MIB(tcps, tcpOutUrg); tcpha->tha_urp = htons(u1); } } tcpha->tha_flags = (uchar_t)flags; tcp->tcp_rack = tcp->tcp_rnxt; tcp->tcp_rack_cnt = 0; if (tcp->tcp_snd_ts_ok) { if (tcp->tcp_state != TCPS_SYN_SENT) { uint32_t llbolt = (uint32_t)LBOLT_FASTPATH; U32_TO_BE32(llbolt, (char *)tcpha + TCP_MIN_HEADER_LENGTH+4); U32_TO_BE32(tcp->tcp_ts_recent, (char *)tcpha + TCP_MIN_HEADER_LENGTH+8); } } if (num_sack_blk > 0) { uchar_t *wptr = (uchar_t *)tcpha + connp->conn_ht_ulp_len; sack_blk_t *tmp; int32_t i; wptr[0] = TCPOPT_NOP; wptr[1] = TCPOPT_NOP; wptr[2] = TCPOPT_SACK; wptr[3] = TCPOPT_HEADER_LEN + num_sack_blk * sizeof (sack_blk_t); wptr += TCPOPT_REAL_SACK_LEN; tmp = tcp->tcp_sack_list; for (i = 0; i < num_sack_blk; i++) { U32_TO_BE32(tmp[i].begin, wptr); wptr += sizeof (tcp_seq); U32_TO_BE32(tmp[i].end, wptr); wptr += sizeof (tcp_seq); } tcpha->tha_offset_and_reserved += ((num_sack_blk * 2 + 1) << 4); } ASSERT((uintptr_t)(mp1->b_wptr - rptr) <= (uintptr_t)INT_MAX); data_length += (int)(mp1->b_wptr - rptr); ixa->ixa_pktlen = data_length; if (ixa->ixa_flags & IXAF_IS_IPV4) { ((ipha_t *)rptr)->ipha_length = htons(data_length); } else { ip6_t *ip6 = (ip6_t *)rptr; ip6->ip6_plen = htons(data_length - IPV6_HDR_LEN); } /* * Prime pump for IP * Include the adjustment for a source route if any. */ data_length -= ixa->ixa_ip_hdr_length; data_length += connp->conn_sum; data_length = (data_length >> 16) + (data_length & 0xFFFF); tcpha->tha_sum = htons(data_length); if (tcp->tcp_ip_forward_progress) { tcp->tcp_ip_forward_progress = B_FALSE; connp->conn_ixa->ixa_flags |= IXAF_REACH_CONF; } else { connp->conn_ixa->ixa_flags &= ~IXAF_REACH_CONF; } return (mp1); } /* * If this routine returns B_TRUE, TCP can generate a RST in response * to a segment. If it returns B_FALSE, TCP should not respond. */ static boolean_t tcp_send_rst_chk(tcp_stack_t *tcps) { int64_t now; /* * TCP needs to protect itself from generating too many RSTs. * This can be a DoS attack by sending us random segments * soliciting RSTs. * * What we do here is to have a limit of tcp_rst_sent_rate RSTs * in each 1 second interval. In this way, TCP still generate * RSTs in normal cases but when under attack, the impact is * limited. */ if (tcps->tcps_rst_sent_rate_enabled != 0) { now = ddi_get_lbolt64(); if (TICK_TO_MSEC(now - tcps->tcps_last_rst_intrvl) > 1*SECONDS) { tcps->tcps_last_rst_intrvl = now; tcps->tcps_rst_cnt = 1; } else if (++tcps->tcps_rst_cnt > tcps->tcps_rst_sent_rate) { return (B_FALSE); } } return (B_TRUE); } /* * This function handles all retransmissions if SACK is enabled for this * connection. First it calculates how many segments can be retransmitted * based on tcp_pipe. Then it goes thru the notsack list to find eligible * segments. A segment is eligible if sack_cnt for that segment is greater * than or equal tcp_dupack_fast_retransmit. After it has retransmitted * all eligible segments, it checks to see if TCP can send some new segments * (fast recovery). If it can, set the appropriate flag for tcp_input_data(). * * Parameters: * tcp_t *tcp: the tcp structure of the connection. * uint_t *flags: in return, appropriate value will be set for * tcp_input_data(). */ void tcp_sack_rexmit(tcp_t *tcp, uint_t *flags) { notsack_blk_t *notsack_blk; int32_t usable_swnd; int32_t mss; uint32_t seg_len; mblk_t *xmit_mp; tcp_stack_t *tcps = tcp->tcp_tcps; ASSERT(tcp->tcp_notsack_list != NULL); ASSERT(tcp->tcp_rexmit == B_FALSE); /* Defensive coding in case there is a bug... */ if (tcp->tcp_notsack_list == NULL) { return; } notsack_blk = tcp->tcp_notsack_list; mss = tcp->tcp_mss; /* * Limit the num of outstanding data in the network to be * tcp_cwnd_ssthresh, which is half of the original congestion wnd. */ usable_swnd = tcp->tcp_cwnd_ssthresh - tcp->tcp_pipe; /* At least retransmit 1 MSS of data. */ if (usable_swnd <= 0) { usable_swnd = mss; } /* Make sure no new RTT samples will be taken. */ tcp->tcp_csuna = tcp->tcp_snxt; notsack_blk = tcp->tcp_notsack_list; while (usable_swnd > 0) { mblk_t *snxt_mp, *tmp_mp; tcp_seq begin = tcp->tcp_sack_snxt; tcp_seq end; int32_t off; for (; notsack_blk != NULL; notsack_blk = notsack_blk->next) { if (SEQ_GT(notsack_blk->end, begin) && (notsack_blk->sack_cnt >= tcps->tcps_dupack_fast_retransmit)) { end = notsack_blk->end; if (SEQ_LT(begin, notsack_blk->begin)) { begin = notsack_blk->begin; } break; } } /* * All holes are filled. Manipulate tcp_cwnd to send more * if we can. Note that after the SACK recovery, tcp_cwnd is * set to tcp_cwnd_ssthresh. */ if (notsack_blk == NULL) { usable_swnd = tcp->tcp_cwnd_ssthresh - tcp->tcp_pipe; if (usable_swnd <= 0 || tcp->tcp_unsent == 0) { tcp->tcp_cwnd = tcp->tcp_snxt - tcp->tcp_suna; ASSERT(tcp->tcp_cwnd > 0); return; } else { usable_swnd = usable_swnd / mss; tcp->tcp_cwnd = tcp->tcp_snxt - tcp->tcp_suna + MAX(usable_swnd * mss, mss); *flags |= TH_XMIT_NEEDED; return; } } /* * Note that we may send more than usable_swnd allows here * because of round off, but no more than 1 MSS of data. */ seg_len = end - begin; if (seg_len > mss) seg_len = mss; snxt_mp = tcp_get_seg_mp(tcp, begin, &off); ASSERT(snxt_mp != NULL); /* This should not happen. Defensive coding again... */ if (snxt_mp == NULL) { return; } xmit_mp = tcp_xmit_mp(tcp, snxt_mp, seg_len, &off, &tmp_mp, begin, B_TRUE, &seg_len, B_TRUE); if (xmit_mp == NULL) return; usable_swnd -= seg_len; tcp->tcp_pipe += seg_len; tcp->tcp_sack_snxt = begin + seg_len; tcp_send_data(tcp, xmit_mp); /* * Update the send timestamp to avoid false retransmission. */ snxt_mp->b_prev = (mblk_t *)ddi_get_lbolt(); TCPS_BUMP_MIB(tcps, tcpRetransSegs); TCPS_UPDATE_MIB(tcps, tcpRetransBytes, seg_len); TCPS_BUMP_MIB(tcps, tcpOutSackRetransSegs); /* * Update tcp_rexmit_max to extend this SACK recovery phase. * This happens when new data sent during fast recovery is * also lost. If TCP retransmits those new data, it needs * to extend SACK recover phase to avoid starting another * fast retransmit/recovery unnecessarily. */ if (SEQ_GT(tcp->tcp_sack_snxt, tcp->tcp_rexmit_max)) { tcp->tcp_rexmit_max = tcp->tcp_sack_snxt; } } } /* * tcp_ss_rexmit() is called to do slow start retransmission after a timeout * or ICMP errors. * * To limit the number of duplicate segments, we limit the number of segment * to be sent in one time to tcp_snd_burst, the burst variable. */ void tcp_ss_rexmit(tcp_t *tcp) { uint32_t snxt; uint32_t smax; int32_t win; int32_t mss; int32_t off; int32_t burst = tcp->tcp_snd_burst; mblk_t *snxt_mp; tcp_stack_t *tcps = tcp->tcp_tcps; /* * Note that tcp_rexmit can be set even though TCP has retransmitted * all unack'ed segments. */ if (SEQ_LT(tcp->tcp_rexmit_nxt, tcp->tcp_rexmit_max)) { smax = tcp->tcp_rexmit_max; snxt = tcp->tcp_rexmit_nxt; if (SEQ_LT(snxt, tcp->tcp_suna)) { snxt = tcp->tcp_suna; } win = MIN(tcp->tcp_cwnd, tcp->tcp_swnd); win -= snxt - tcp->tcp_suna; mss = tcp->tcp_mss; snxt_mp = tcp_get_seg_mp(tcp, snxt, &off); while (SEQ_LT(snxt, smax) && (win > 0) && (burst > 0) && (snxt_mp != NULL)) { mblk_t *xmit_mp; mblk_t *old_snxt_mp = snxt_mp; uint32_t cnt = mss; if (win < cnt) { cnt = win; } if (SEQ_GT(snxt + cnt, smax)) { cnt = smax - snxt; } xmit_mp = tcp_xmit_mp(tcp, snxt_mp, cnt, &off, &snxt_mp, snxt, B_TRUE, &cnt, B_TRUE); if (xmit_mp == NULL) return; tcp_send_data(tcp, xmit_mp); snxt += cnt; win -= cnt; /* * Update the send timestamp to avoid false * retransmission. */ old_snxt_mp->b_prev = (mblk_t *)ddi_get_lbolt(); TCPS_BUMP_MIB(tcps, tcpRetransSegs); TCPS_UPDATE_MIB(tcps, tcpRetransBytes, cnt); tcp->tcp_rexmit_nxt = snxt; burst--; } /* * If we have transmitted all we have at the time * we started the retranmission, we can leave * the rest of the job to tcp_wput_data(). But we * need to check the send window first. If the * win is not 0, go on with tcp_wput_data(). */ if (SEQ_LT(snxt, smax) || win == 0) { return; } } /* Only call tcp_wput_data() if there is data to be sent. */ if (tcp->tcp_unsent) { tcp_wput_data(tcp, NULL, B_FALSE); } } /* * Do slow start retransmission after ICMP errors of PMTU changes. */ void tcp_rexmit_after_error(tcp_t *tcp) { /* * All sent data has been acknowledged or no data left to send, just * to return. */ if (!SEQ_LT(tcp->tcp_suna, tcp->tcp_snxt) || (tcp->tcp_xmit_head == NULL)) return; if ((tcp->tcp_valid_bits & TCP_FSS_VALID) && (tcp->tcp_unsent == 0)) tcp->tcp_rexmit_max = tcp->tcp_fss; else tcp->tcp_rexmit_max = tcp->tcp_snxt; tcp->tcp_rexmit_nxt = tcp->tcp_suna; tcp->tcp_rexmit = B_TRUE; tcp->tcp_dupack_cnt = 0; tcp->tcp_snd_burst = TCP_CWND_SS; tcp_ss_rexmit(tcp); } /* * tcp_get_seg_mp() is called to get the pointer to a segment in the * send queue which starts at the given sequence number. If the given * sequence number is equal to last valid sequence number (tcp_snxt), the * returned mblk is the last valid mblk, and off is set to the length of * that mblk. * * send queue which starts at the given seq. no. * * Parameters: * tcp_t *tcp: the tcp instance pointer. * uint32_t seq: the starting seq. no of the requested segment. * int32_t *off: after the execution, *off will be the offset to * the returned mblk which points to the requested seq no. * It is the caller's responsibility to send in a non-null off. * * Return: * A mblk_t pointer pointing to the requested segment in send queue. */ static mblk_t * tcp_get_seg_mp(tcp_t *tcp, uint32_t seq, int32_t *off) { int32_t cnt; mblk_t *mp; /* Defensive coding. Make sure we don't send incorrect data. */ if (SEQ_LT(seq, tcp->tcp_suna) || SEQ_GT(seq, tcp->tcp_snxt)) return (NULL); cnt = seq - tcp->tcp_suna; mp = tcp->tcp_xmit_head; while (cnt > 0 && mp != NULL) { cnt -= mp->b_wptr - mp->b_rptr; if (cnt <= 0) { cnt += mp->b_wptr - mp->b_rptr; break; } mp = mp->b_cont; } ASSERT(mp != NULL); *off = cnt; return (mp); } /* * This routine adjusts next-to-send sequence number variables, in the * case where the reciever has shrunk it's window. */ void tcp_update_xmit_tail(tcp_t *tcp, uint32_t snxt) { mblk_t *xmit_tail; int32_t offset; tcp->tcp_snxt = snxt; /* Get the mblk, and the offset in it, as per the shrunk window */ xmit_tail = tcp_get_seg_mp(tcp, snxt, &offset); ASSERT(xmit_tail != NULL); tcp->tcp_xmit_tail = xmit_tail; tcp->tcp_xmit_tail_unsent = xmit_tail->b_wptr - xmit_tail->b_rptr - offset; } /* * This handles the case when the receiver has shrunk its win. Per RFC 1122 * if the receiver shrinks the window, i.e. moves the right window to the * left, the we should not send new data, but should retransmit normally the * old unacked data between suna and suna + swnd. We might has sent data * that is now outside the new window, pretend that we didn't send it. */ static void tcp_process_shrunk_swnd(tcp_t *tcp, uint32_t shrunk_count) { uint32_t snxt = tcp->tcp_snxt; ASSERT(shrunk_count > 0); if (!tcp->tcp_is_wnd_shrnk) { tcp->tcp_snxt_shrunk = snxt; tcp->tcp_is_wnd_shrnk = B_TRUE; } else if (SEQ_GT(snxt, tcp->tcp_snxt_shrunk)) { tcp->tcp_snxt_shrunk = snxt; } /* Pretend we didn't send the data outside the window */ snxt -= shrunk_count; /* Reset all the values per the now shrunk window */ tcp_update_xmit_tail(tcp, snxt); tcp->tcp_unsent += shrunk_count; /* * If the SACK option is set, delete the entire list of * notsack'ed blocks. */ TCP_NOTSACK_REMOVE_ALL(tcp->tcp_notsack_list, tcp); if (tcp->tcp_suna == tcp->tcp_snxt && tcp->tcp_swnd == 0) /* * Make sure the timer is running so that we will probe a zero * window. */ TCP_TIMER_RESTART(tcp, tcp->tcp_rto); } /* * tcp_fill_header is called by tcp_send() to fill the outgoing TCP header * with the template header, as well as other options such as time-stamp, * ECN and/or SACK. */ static void tcp_fill_header(tcp_t *tcp, uchar_t *rptr, clock_t now, int num_sack_blk) { tcpha_t *tcp_tmpl, *tcpha; uint32_t *dst, *src; int hdrlen; conn_t *connp = tcp->tcp_connp; ASSERT(OK_32PTR(rptr)); /* Template header */ tcp_tmpl = tcp->tcp_tcpha; /* Header of outgoing packet */ tcpha = (tcpha_t *)(rptr + connp->conn_ixa->ixa_ip_hdr_length); /* dst and src are opaque 32-bit fields, used for copying */ dst = (uint32_t *)rptr; src = (uint32_t *)connp->conn_ht_iphc; hdrlen = connp->conn_ht_iphc_len; /* Fill time-stamp option if needed */ if (tcp->tcp_snd_ts_ok) { U32_TO_BE32((uint32_t)now, (char *)tcp_tmpl + TCP_MIN_HEADER_LENGTH + 4); U32_TO_BE32(tcp->tcp_ts_recent, (char *)tcp_tmpl + TCP_MIN_HEADER_LENGTH + 8); } else { ASSERT(connp->conn_ht_ulp_len == TCP_MIN_HEADER_LENGTH); } /* * Copy the template header; is this really more efficient than * calling bcopy()? For simple IPv4/TCP, it may be the case, * but perhaps not for other scenarios. */ dst[0] = src[0]; dst[1] = src[1]; dst[2] = src[2]; dst[3] = src[3]; dst[4] = src[4]; dst[5] = src[5]; dst[6] = src[6]; dst[7] = src[7]; dst[8] = src[8]; dst[9] = src[9]; if (hdrlen -= 40) { hdrlen >>= 2; dst += 10; src += 10; do { *dst++ = *src++; } while (--hdrlen); } /* * Set the ECN info in the TCP header if it is not a zero * window probe. Zero window probe is only sent in * tcp_wput_data() and tcp_timer(). */ if (tcp->tcp_ecn_ok && !tcp->tcp_zero_win_probe) { TCP_SET_ECT(tcp, rptr); if (tcp->tcp_ecn_echo_on) tcpha->tha_flags |= TH_ECE; if (tcp->tcp_cwr && !tcp->tcp_ecn_cwr_sent) { tcpha->tha_flags |= TH_CWR; tcp->tcp_ecn_cwr_sent = B_TRUE; } } /* Fill in SACK options */ if (num_sack_blk > 0) { uchar_t *wptr = rptr + connp->conn_ht_iphc_len; sack_blk_t *tmp; int32_t i; wptr[0] = TCPOPT_NOP; wptr[1] = TCPOPT_NOP; wptr[2] = TCPOPT_SACK; wptr[3] = TCPOPT_HEADER_LEN + num_sack_blk * sizeof (sack_blk_t); wptr += TCPOPT_REAL_SACK_LEN; tmp = tcp->tcp_sack_list; for (i = 0; i < num_sack_blk; i++) { U32_TO_BE32(tmp[i].begin, wptr); wptr += sizeof (tcp_seq); U32_TO_BE32(tmp[i].end, wptr); wptr += sizeof (tcp_seq); } tcpha->tha_offset_and_reserved += ((num_sack_blk * 2 + 1) << 4); } }