398 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 399 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 400 401 /* Skip initialization of globals for non-default instances. */ 402 if (!IS_DEFAULT_VNET(curvnet)) 403 return; 404 405 /* XXX virtualize those bellow? */ 406 tcp_delacktime = TCPTV_DELACK; 407 tcp_keepinit = TCPTV_KEEP_INIT; 408 tcp_keepidle = TCPTV_KEEP_IDLE; 409 tcp_keepintvl = TCPTV_KEEPINTVL; 410 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 411 tcp_msl = TCPTV_MSL; 412 tcp_rexmit_min = TCPTV_MIN; 413 if (tcp_rexmit_min < 1) 414 tcp_rexmit_min = 1; 415 tcp_rexmit_slop = TCPTV_CPU_VAR; 416 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 417 tcp_tcbhashsize = hashsize; 418 419#ifdef TCP_SORECEIVE_STREAM 420 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 421 if (tcp_soreceive_stream) { 422 tcp_usrreqs.pru_soreceive = soreceive_stream; 423 tcp6_usrreqs.pru_soreceive = soreceive_stream; 424 } 425#endif 426 427#ifdef INET6 428#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 429#else /* INET6 */ 430#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 431#endif /* INET6 */ 432 if (max_protohdr < TCP_MINPROTOHDR) 433 max_protohdr = TCP_MINPROTOHDR; 434 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 435 panic("tcp_init"); 436#undef TCP_MINPROTOHDR 437 438 ISN_LOCK_INIT(); 439 callout_init(&isn_callout, CALLOUT_MPSAFE); 440 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 441 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 442 SHUTDOWN_PRI_DEFAULT); 443 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 444 EVENTHANDLER_PRI_ANY); 445} 446 447#ifdef VIMAGE 448void 449tcp_destroy(void) 450{ 451 452 tcp_reass_destroy(); 453 tcp_hc_destroy(); 454 syncache_destroy(); 455 tcp_tw_destroy(); 456 in_pcbinfo_destroy(&V_tcbinfo); 457 uma_zdestroy(V_sack_hole_zone); 458 uma_zdestroy(V_tcpcb_zone); 459} 460#endif 461 462void 463tcp_fini(void *xtp) 464{ 465 466 callout_stop(&isn_callout); 467} 468 469/* 470 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 471 * tcp_template used to store this data in mbufs, but we now recopy it out 472 * of the tcpcb each time to conserve mbufs. 473 */ 474void 475tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 476{ 477 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 478 479 INP_WLOCK_ASSERT(inp); 480 481#ifdef INET6 482 if ((inp->inp_vflag & INP_IPV6) != 0) { 483 struct ip6_hdr *ip6; 484 485 ip6 = (struct ip6_hdr *)ip_ptr; 486 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 487 (inp->inp_flow & IPV6_FLOWINFO_MASK); 488 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 489 (IPV6_VERSION & IPV6_VERSION_MASK); 490 ip6->ip6_nxt = IPPROTO_TCP; 491 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 492 ip6->ip6_src = inp->in6p_laddr; 493 ip6->ip6_dst = inp->in6p_faddr; 494 } else 495#endif 496 { 497 struct ip *ip; 498 499 ip = (struct ip *)ip_ptr; 500 ip->ip_v = IPVERSION; 501 ip->ip_hl = 5; 502 ip->ip_tos = inp->inp_ip_tos; 503 ip->ip_len = 0; 504 ip->ip_id = 0; 505 ip->ip_off = 0; 506 ip->ip_ttl = inp->inp_ip_ttl; 507 ip->ip_sum = 0; 508 ip->ip_p = IPPROTO_TCP; 509 ip->ip_src = inp->inp_laddr; 510 ip->ip_dst = inp->inp_faddr; 511 } 512 th->th_sport = inp->inp_lport; 513 th->th_dport = inp->inp_fport; 514 th->th_seq = 0; 515 th->th_ack = 0; 516 th->th_x2 = 0; 517 th->th_off = 5; 518 th->th_flags = 0; 519 th->th_win = 0; 520 th->th_urp = 0; 521 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 522} 523 524/* 525 * Create template to be used to send tcp packets on a connection. 526 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 527 * use for this function is in keepalives, which use tcp_respond. 528 */ 529struct tcptemp * 530tcpip_maketemplate(struct inpcb *inp) 531{ 532 struct tcptemp *t; 533 534 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 535 if (t == NULL) 536 return (NULL); 537 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 538 return (t); 539} 540 541/* 542 * Send a single message to the TCP at address specified by 543 * the given TCP/IP header. If m == NULL, then we make a copy 544 * of the tcpiphdr at ti and send directly to the addressed host. 545 * This is used to force keep alive messages out using the TCP 546 * template for a connection. If flags are given then we send 547 * a message back to the TCP which originated the * segment ti, 548 * and discard the mbuf containing it and any other attached mbufs. 549 * 550 * In any case the ack and sequence number of the transmitted 551 * segment are as specified by the parameters. 552 * 553 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 554 */ 555void 556tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 557 tcp_seq ack, tcp_seq seq, int flags) 558{ 559 int tlen; 560 int win = 0; 561 struct ip *ip; 562 struct tcphdr *nth; 563#ifdef INET6 564 struct ip6_hdr *ip6; 565 int isipv6; 566#endif /* INET6 */ 567 int ipflags = 0; 568 struct inpcb *inp; 569 570 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 571 572#ifdef INET6 573 isipv6 = ((struct ip *)ipgen)->ip_v == 6; 574 ip6 = ipgen; 575#endif /* INET6 */ 576 ip = ipgen; 577 578 if (tp != NULL) { 579 inp = tp->t_inpcb; 580 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 581 INP_WLOCK_ASSERT(inp); 582 } else 583 inp = NULL; 584 585 if (tp != NULL) { 586 if (!(flags & TH_RST)) { 587 win = sbspace(&inp->inp_socket->so_rcv); 588 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 589 win = (long)TCP_MAXWIN << tp->rcv_scale; 590 } 591 } 592 if (m == NULL) { 593 m = m_gethdr(M_DONTWAIT, MT_DATA); 594 if (m == NULL) 595 return; 596 tlen = 0; 597 m->m_data += max_linkhdr; 598#ifdef INET6 599 if (isipv6) { 600 bcopy((caddr_t)ip6, mtod(m, caddr_t), 601 sizeof(struct ip6_hdr)); 602 ip6 = mtod(m, struct ip6_hdr *); 603 nth = (struct tcphdr *)(ip6 + 1); 604 } else 605#endif /* INET6 */ 606 { 607 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 608 ip = mtod(m, struct ip *); 609 nth = (struct tcphdr *)(ip + 1); 610 } 611 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 612 flags = TH_ACK; 613 } else { 614 /* 615 * reuse the mbuf. 616 * XXX MRT We inherrit the FIB, which is lucky. 617 */ 618 m_freem(m->m_next); 619 m->m_next = NULL; 620 m->m_data = (caddr_t)ipgen; 621 /* m_len is set later */ 622 tlen = 0; 623#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 624#ifdef INET6 625 if (isipv6) { 626 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 627 nth = (struct tcphdr *)(ip6 + 1); 628 } else 629#endif /* INET6 */ 630 { 631 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 632 nth = (struct tcphdr *)(ip + 1); 633 } 634 if (th != nth) { 635 /* 636 * this is usually a case when an extension header 637 * exists between the IPv6 header and the 638 * TCP header. 639 */ 640 nth->th_sport = th->th_sport; 641 nth->th_dport = th->th_dport; 642 } 643 xchg(nth->th_dport, nth->th_sport, uint16_t); 644#undef xchg 645 } 646#ifdef INET6 647 if (isipv6) { 648 ip6->ip6_flow = 0; 649 ip6->ip6_vfc = IPV6_VERSION; 650 ip6->ip6_nxt = IPPROTO_TCP; 651 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 652 tlen)); 653 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 654 } else 655#endif 656 { 657 tlen += sizeof (struct tcpiphdr); 658 ip->ip_len = tlen; 659 ip->ip_ttl = V_ip_defttl; 660 if (V_path_mtu_discovery) 661 ip->ip_off |= IP_DF; 662 } 663 m->m_len = tlen; 664 m->m_pkthdr.len = tlen; 665 m->m_pkthdr.rcvif = NULL; 666#ifdef MAC 667 if (inp != NULL) { 668 /* 669 * Packet is associated with a socket, so allow the 670 * label of the response to reflect the socket label. 671 */ 672 INP_WLOCK_ASSERT(inp); 673 mac_inpcb_create_mbuf(inp, m); 674 } else { 675 /* 676 * Packet is not associated with a socket, so possibly 677 * update the label in place. 678 */ 679 mac_netinet_tcp_reply(m); 680 } 681#endif 682 nth->th_seq = htonl(seq); 683 nth->th_ack = htonl(ack); 684 nth->th_x2 = 0; 685 nth->th_off = sizeof (struct tcphdr) >> 2; 686 nth->th_flags = flags; 687 if (tp != NULL) 688 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 689 else 690 nth->th_win = htons((u_short)win); 691 nth->th_urp = 0; 692#ifdef INET6 693 if (isipv6) { 694 nth->th_sum = 0; 695 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 696 sizeof(struct ip6_hdr), 697 tlen - sizeof(struct ip6_hdr)); 698 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 699 NULL, NULL); 700 } else 701#endif /* INET6 */ 702 { 703 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 704 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 705 m->m_pkthdr.csum_flags = CSUM_TCP; 706 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 707 } 708#ifdef TCPDEBUG 709 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 710 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 711#endif 712#ifdef INET6 713 if (isipv6) 714 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 715 else 716#endif /* INET6 */ 717 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 718} 719 720/* 721 * Create a new TCP control block, making an 722 * empty reassembly queue and hooking it to the argument 723 * protocol control block. The `inp' parameter must have 724 * come from the zone allocator set up in tcp_init(). 725 */ 726struct tcpcb * 727tcp_newtcpcb(struct inpcb *inp) 728{ 729 struct tcpcb_mem *tm; 730 struct tcpcb *tp; 731#ifdef INET6 732 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 733#endif /* INET6 */ 734 735 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 736 if (tm == NULL) 737 return (NULL); 738 tp = &tm->tcb; 739#ifdef VIMAGE 740 tp->t_vnet = inp->inp_vnet; 741#endif 742 tp->t_timers = &tm->tt; 743 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 744 tp->t_maxseg = tp->t_maxopd = 745#ifdef INET6 746 isipv6 ? V_tcp_v6mssdflt : 747#endif /* INET6 */ 748 V_tcp_mssdflt; 749 750 /* Set up our timeouts. */ 751 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 752 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 753 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 754 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 755 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 756 757 if (V_tcp_do_rfc1323) 758 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 759 if (V_tcp_do_sack) 760 tp->t_flags |= TF_SACK_PERMIT; 761 TAILQ_INIT(&tp->snd_holes); 762 tp->t_inpcb = inp; /* XXX */ 763 /* 764 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 765 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 766 * reasonable initial retransmit time. 767 */ 768 tp->t_srtt = TCPTV_SRTTBASE; 769 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 770 tp->t_rttmin = tcp_rexmit_min; 771 tp->t_rxtcur = TCPTV_RTOBASE; 772 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 773 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 774 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 775 tp->t_rcvtime = ticks; 776 tp->t_bw_rtttime = ticks; 777 /* 778 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 779 * because the socket may be bound to an IPv6 wildcard address, 780 * which may match an IPv4-mapped IPv6 address. 781 */ 782 inp->inp_ip_ttl = V_ip_defttl; 783 inp->inp_ppcb = tp; 784 return (tp); /* XXX */ 785} 786 787/* 788 * Drop a TCP connection, reporting 789 * the specified error. If connection is synchronized, 790 * then send a RST to peer. 791 */ 792struct tcpcb * 793tcp_drop(struct tcpcb *tp, int errno) 794{ 795 struct socket *so = tp->t_inpcb->inp_socket; 796 797 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 798 INP_WLOCK_ASSERT(tp->t_inpcb); 799 800 if (TCPS_HAVERCVDSYN(tp->t_state)) { 801 tp->t_state = TCPS_CLOSED; 802 (void) tcp_output_reset(tp); 803 TCPSTAT_INC(tcps_drops); 804 } else 805 TCPSTAT_INC(tcps_conndrops); 806 if (errno == ETIMEDOUT && tp->t_softerror) 807 errno = tp->t_softerror; 808 so->so_error = errno; 809 return (tcp_close(tp)); 810} 811 812void 813tcp_discardcb(struct tcpcb *tp) 814{ 815 struct tseg_qent *q; 816 struct inpcb *inp = tp->t_inpcb; 817 struct socket *so = inp->inp_socket; 818#ifdef INET6 819 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 820#endif /* INET6 */ 821 822 INP_WLOCK_ASSERT(inp); 823 824 /* 825 * Make sure that all of our timers are stopped before we delete the 826 * PCB. 827 * 828 * XXXRW: Really, we would like to use callout_drain() here in order 829 * to avoid races experienced in tcp_timer.c where a timer is already 830 * executing at this point. However, we can't, both because we're 831 * running in a context where we can't sleep, and also because we 832 * hold locks required by the timers. What we instead need to do is 833 * test to see if callout_drain() is required, and if so, defer some 834 * portion of the remainder of tcp_discardcb() to an asynchronous 835 * context that can callout_drain() and then continue. Some care 836 * will be required to ensure that no further processing takes place 837 * on the tcpcb, even though it hasn't been freed (a flag?). 838 */ 839 callout_stop(&tp->t_timers->tt_rexmt); 840 callout_stop(&tp->t_timers->tt_persist); 841 callout_stop(&tp->t_timers->tt_keep); 842 callout_stop(&tp->t_timers->tt_2msl); 843 callout_stop(&tp->t_timers->tt_delack); 844 845 /* 846 * If we got enough samples through the srtt filter, 847 * save the rtt and rttvar in the routing entry. 848 * 'Enough' is arbitrarily defined as 4 rtt samples. 849 * 4 samples is enough for the srtt filter to converge 850 * to within enough % of the correct value; fewer samples 851 * and we could save a bogus rtt. The danger is not high 852 * as tcp quickly recovers from everything. 853 * XXX: Works very well but needs some more statistics! 854 */ 855 if (tp->t_rttupdated >= 4) { 856 struct hc_metrics_lite metrics; 857 u_long ssthresh; 858 859 bzero(&metrics, sizeof(metrics)); 860 /* 861 * Update the ssthresh always when the conditions below 862 * are satisfied. This gives us better new start value 863 * for the congestion avoidance for new connections. 864 * ssthresh is only set if packet loss occured on a session. 865 * 866 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 867 * being torn down. Ideally this code would not use 'so'. 868 */ 869 ssthresh = tp->snd_ssthresh; 870 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 871 /* 872 * convert the limit from user data bytes to 873 * packets then to packet data bytes. 874 */ 875 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 876 if (ssthresh < 2) 877 ssthresh = 2; 878 ssthresh *= (u_long)(tp->t_maxseg + 879#ifdef INET6 880 (isipv6 ? sizeof (struct ip6_hdr) + 881 sizeof (struct tcphdr) : 882#endif 883 sizeof (struct tcpiphdr) 884#ifdef INET6 885 ) 886#endif 887 ); 888 } else 889 ssthresh = 0; 890 metrics.rmx_ssthresh = ssthresh; 891 892 metrics.rmx_rtt = tp->t_srtt; 893 metrics.rmx_rttvar = tp->t_rttvar; 894 /* XXX: This wraps if the pipe is more than 4 Gbit per second */ 895 metrics.rmx_bandwidth = tp->snd_bandwidth; 896 metrics.rmx_cwnd = tp->snd_cwnd; 897 metrics.rmx_sendpipe = 0; 898 metrics.rmx_recvpipe = 0; 899 900 tcp_hc_update(&inp->inp_inc, &metrics); 901 } 902 903 /* free the reassembly queue, if any */ 904 while ((q = LIST_FIRST(&tp->t_segq)) != NULL) { 905 LIST_REMOVE(q, tqe_q); 906 m_freem(q->tqe_m); 907 uma_zfree(V_tcp_reass_zone, q); 908 tp->t_segqlen--; 909 V_tcp_reass_qsize--; 910 } 911 /* Disconnect offload device, if any. */ 912 tcp_offload_detach(tp); 913 914 tcp_free_sackholes(tp); 915 inp->inp_ppcb = NULL; 916 tp->t_inpcb = NULL; 917 uma_zfree(V_tcpcb_zone, tp); 918} 919 920/* 921 * Attempt to close a TCP control block, marking it as dropped, and freeing 922 * the socket if we hold the only reference. 923 */ 924struct tcpcb * 925tcp_close(struct tcpcb *tp) 926{ 927 struct inpcb *inp = tp->t_inpcb; 928 struct socket *so; 929 930 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 931 INP_WLOCK_ASSERT(inp); 932 933 /* Notify any offload devices of listener close */ 934 if (tp->t_state == TCPS_LISTEN) 935 tcp_offload_listen_close(tp); 936 in_pcbdrop(inp); 937 TCPSTAT_INC(tcps_closed); 938 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 939 so = inp->inp_socket; 940 soisdisconnected(so); 941 if (inp->inp_flags & INP_SOCKREF) { 942 KASSERT(so->so_state & SS_PROTOREF, 943 ("tcp_close: !SS_PROTOREF")); 944 inp->inp_flags &= ~INP_SOCKREF; 945 INP_WUNLOCK(inp); 946 ACCEPT_LOCK(); 947 SOCK_LOCK(so); 948 so->so_state &= ~SS_PROTOREF; 949 sofree(so); 950 return (NULL); 951 } 952 return (tp); 953} 954 955void 956tcp_drain(void) 957{ 958 VNET_ITERATOR_DECL(vnet_iter); 959 960 if (!do_tcpdrain) 961 return; 962 963 VNET_LIST_RLOCK_NOSLEEP(); 964 VNET_FOREACH(vnet_iter) { 965 CURVNET_SET(vnet_iter); 966 struct inpcb *inpb; 967 struct tcpcb *tcpb; 968 struct tseg_qent *te; 969 970 /* 971 * Walk the tcpbs, if existing, and flush the reassembly queue, 972 * if there is one... 973 * XXX: The "Net/3" implementation doesn't imply that the TCP 974 * reassembly queue should be flushed, but in a situation 975 * where we're really low on mbufs, this is potentially 976 * usefull. 977 */ 978 INP_INFO_RLOCK(&V_tcbinfo); 979 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 980 if (inpb->inp_flags & INP_TIMEWAIT) 981 continue; 982 INP_WLOCK(inpb); 983 if ((tcpb = intotcpcb(inpb)) != NULL) { 984 while ((te = LIST_FIRST(&tcpb->t_segq)) 985 != NULL) { 986 LIST_REMOVE(te, tqe_q); 987 m_freem(te->tqe_m); 988 uma_zfree(V_tcp_reass_zone, te); 989 tcpb->t_segqlen--; 990 V_tcp_reass_qsize--; 991 } 992 tcp_clean_sackreport(tcpb); 993 } 994 INP_WUNLOCK(inpb); 995 } 996 INP_INFO_RUNLOCK(&V_tcbinfo); 997 CURVNET_RESTORE(); 998 } 999 VNET_LIST_RUNLOCK_NOSLEEP(); 1000} 1001 1002/* 1003 * Notify a tcp user of an asynchronous error; 1004 * store error as soft error, but wake up user 1005 * (for now, won't do anything until can select for soft error). 1006 * 1007 * Do not wake up user since there currently is no mechanism for 1008 * reporting soft errors (yet - a kqueue filter may be added). 1009 */ 1010static struct inpcb * 1011tcp_notify(struct inpcb *inp, int error) 1012{ 1013 struct tcpcb *tp; 1014 1015 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1016 INP_WLOCK_ASSERT(inp); 1017 1018 if ((inp->inp_flags & INP_TIMEWAIT) || 1019 (inp->inp_flags & INP_DROPPED)) 1020 return (inp); 1021 1022 tp = intotcpcb(inp); 1023 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 1024 1025 /* 1026 * Ignore some errors if we are hooked up. 1027 * If connection hasn't completed, has retransmitted several times, 1028 * and receives a second error, give up now. This is better 1029 * than waiting a long time to establish a connection that 1030 * can never complete. 1031 */ 1032 if (tp->t_state == TCPS_ESTABLISHED && 1033 (error == EHOSTUNREACH || error == ENETUNREACH || 1034 error == EHOSTDOWN)) { 1035 return (inp); 1036 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 1037 tp->t_softerror) { 1038 tp = tcp_drop(tp, error); 1039 if (tp != NULL) 1040 return (inp); 1041 else 1042 return (NULL); 1043 } else { 1044 tp->t_softerror = error; 1045 return (inp); 1046 } 1047#if 0 1048 wakeup( &so->so_timeo); 1049 sorwakeup(so); 1050 sowwakeup(so); 1051#endif 1052} 1053 1054static int 1055tcp_pcblist(SYSCTL_HANDLER_ARGS) 1056{ 1057 int error, i, m, n, pcb_count; 1058 struct inpcb *inp, **inp_list; 1059 inp_gen_t gencnt; 1060 struct xinpgen xig; 1061 1062 /* 1063 * The process of preparing the TCB list is too time-consuming and 1064 * resource-intensive to repeat twice on every request. 1065 */ 1066 if (req->oldptr == NULL) { 1067 m = syncache_pcbcount(); 1068 n = V_tcbinfo.ipi_count; 1069 req->oldidx = 2 * (sizeof xig) 1070 + ((m + n) + n/8) * sizeof(struct xtcpcb); 1071 return (0); 1072 } 1073 1074 if (req->newptr != NULL) 1075 return (EPERM); 1076 1077 /* 1078 * OK, now we're committed to doing something. 1079 */ 1080 INP_INFO_RLOCK(&V_tcbinfo); 1081 gencnt = V_tcbinfo.ipi_gencnt; 1082 n = V_tcbinfo.ipi_count; 1083 INP_INFO_RUNLOCK(&V_tcbinfo); 1084 1085 m = syncache_pcbcount(); 1086 1087 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1088 + (n + m) * sizeof(struct xtcpcb)); 1089 if (error != 0) 1090 return (error); 1091 1092 xig.xig_len = sizeof xig; 1093 xig.xig_count = n + m; 1094 xig.xig_gen = gencnt; 1095 xig.xig_sogen = so_gencnt; 1096 error = SYSCTL_OUT(req, &xig, sizeof xig); 1097 if (error) 1098 return (error); 1099 1100 error = syncache_pcblist(req, m, &pcb_count); 1101 if (error) 1102 return (error); 1103 1104 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1105 if (inp_list == NULL) 1106 return (ENOMEM); 1107 1108 INP_INFO_RLOCK(&V_tcbinfo); 1109 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1110 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1111 INP_WLOCK(inp); 1112 if (inp->inp_gencnt <= gencnt) { 1113 /* 1114 * XXX: This use of cr_cansee(), introduced with 1115 * TCP state changes, is not quite right, but for 1116 * now, better than nothing. 1117 */ 1118 if (inp->inp_flags & INP_TIMEWAIT) { 1119 if (intotw(inp) != NULL) 1120 error = cr_cansee(req->td->td_ucred, 1121 intotw(inp)->tw_cred); 1122 else 1123 error = EINVAL; /* Skip this inp. */ 1124 } else 1125 error = cr_canseeinpcb(req->td->td_ucred, inp); 1126 if (error == 0) { 1127 in_pcbref(inp); 1128 inp_list[i++] = inp; 1129 } 1130 } 1131 INP_WUNLOCK(inp); 1132 } 1133 INP_INFO_RUNLOCK(&V_tcbinfo); 1134 n = i; 1135 1136 error = 0; 1137 for (i = 0; i < n; i++) { 1138 inp = inp_list[i]; 1139 INP_RLOCK(inp); 1140 if (inp->inp_gencnt <= gencnt) { 1141 struct xtcpcb xt; 1142 void *inp_ppcb; 1143 1144 bzero(&xt, sizeof(xt)); 1145 xt.xt_len = sizeof xt; 1146 /* XXX should avoid extra copy */ 1147 bcopy(inp, &xt.xt_inp, sizeof *inp); 1148 inp_ppcb = inp->inp_ppcb; 1149 if (inp_ppcb == NULL) 1150 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1151 else if (inp->inp_flags & INP_TIMEWAIT) { 1152 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1153 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1154 } else { 1155 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1156 if (xt.xt_tp.t_timers) 1157 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1158 } 1159 if (inp->inp_socket != NULL) 1160 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1161 else { 1162 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1163 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1164 } 1165 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1166 INP_RUNLOCK(inp); 1167 error = SYSCTL_OUT(req, &xt, sizeof xt); 1168 } else 1169 INP_RUNLOCK(inp); 1170 } 1171 INP_INFO_WLOCK(&V_tcbinfo); 1172 for (i = 0; i < n; i++) { 1173 inp = inp_list[i]; 1174 INP_WLOCK(inp); 1175 if (!in_pcbrele(inp)) 1176 INP_WUNLOCK(inp); 1177 } 1178 INP_INFO_WUNLOCK(&V_tcbinfo); 1179 1180 if (!error) { 1181 /* 1182 * Give the user an updated idea of our state. 1183 * If the generation differs from what we told 1184 * her before, she knows that something happened 1185 * while we were processing this request, and it 1186 * might be necessary to retry. 1187 */ 1188 INP_INFO_RLOCK(&V_tcbinfo); 1189 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1190 xig.xig_sogen = so_gencnt; 1191 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1192 INP_INFO_RUNLOCK(&V_tcbinfo); 1193 error = SYSCTL_OUT(req, &xig, sizeof xig); 1194 } 1195 free(inp_list, M_TEMP); 1196 return (error); 1197} 1198 1199SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1200 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1201 1202static int 1203tcp_getcred(SYSCTL_HANDLER_ARGS) 1204{ 1205 struct xucred xuc; 1206 struct sockaddr_in addrs[2]; 1207 struct inpcb *inp; 1208 int error; 1209 1210 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1211 if (error) 1212 return (error); 1213 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1214 if (error) 1215 return (error); 1216 INP_INFO_RLOCK(&V_tcbinfo); 1217 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr, 1218 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1219 if (inp != NULL) { 1220 INP_RLOCK(inp); 1221 INP_INFO_RUNLOCK(&V_tcbinfo); 1222 if (inp->inp_socket == NULL) 1223 error = ENOENT; 1224 if (error == 0) 1225 error = cr_canseeinpcb(req->td->td_ucred, inp); 1226 if (error == 0) 1227 cru2x(inp->inp_cred, &xuc); 1228 INP_RUNLOCK(inp); 1229 } else { 1230 INP_INFO_RUNLOCK(&V_tcbinfo); 1231 error = ENOENT; 1232 } 1233 if (error == 0) 1234 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1235 return (error); 1236} 1237 1238SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1239 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1240 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1241 1242#ifdef INET6 1243static int 1244tcp6_getcred(SYSCTL_HANDLER_ARGS) 1245{ 1246 struct xucred xuc; 1247 struct sockaddr_in6 addrs[2]; 1248 struct inpcb *inp; 1249 int error, mapped = 0; 1250 1251 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1252 if (error) 1253 return (error); 1254 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1255 if (error) 1256 return (error); 1257 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1258 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1259 return (error); 1260 } 1261 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1262 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1263 mapped = 1; 1264 else 1265 return (EINVAL); 1266 } 1267 1268 INP_INFO_RLOCK(&V_tcbinfo); 1269 if (mapped == 1) 1270 inp = in_pcblookup_hash(&V_tcbinfo, 1271 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1272 addrs[1].sin6_port, 1273 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1274 addrs[0].sin6_port, 1275 0, NULL); 1276 else 1277 inp = in6_pcblookup_hash(&V_tcbinfo, 1278 &addrs[1].sin6_addr, addrs[1].sin6_port, 1279 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1280 if (inp != NULL) { 1281 INP_RLOCK(inp); 1282 INP_INFO_RUNLOCK(&V_tcbinfo); 1283 if (inp->inp_socket == NULL) 1284 error = ENOENT; 1285 if (error == 0) 1286 error = cr_canseeinpcb(req->td->td_ucred, inp); 1287 if (error == 0) 1288 cru2x(inp->inp_cred, &xuc); 1289 INP_RUNLOCK(inp); 1290 } else { 1291 INP_INFO_RUNLOCK(&V_tcbinfo); 1292 error = ENOENT; 1293 } 1294 if (error == 0) 1295 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1296 return (error); 1297} 1298 1299SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1300 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1301 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1302#endif 1303 1304 1305void 1306tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1307{ 1308 struct ip *ip = vip; 1309 struct tcphdr *th; 1310 struct in_addr faddr; 1311 struct inpcb *inp; 1312 struct tcpcb *tp; 1313 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1314 struct icmp *icp; 1315 struct in_conninfo inc; 1316 tcp_seq icmp_tcp_seq; 1317 int mtu; 1318 1319 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1320 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1321 return; 1322 1323 if (cmd == PRC_MSGSIZE) 1324 notify = tcp_mtudisc; 1325 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1326 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1327 notify = tcp_drop_syn_sent; 1328 /* 1329 * Redirects don't need to be handled up here. 1330 */ 1331 else if (PRC_IS_REDIRECT(cmd)) 1332 return; 1333 /* 1334 * Source quench is depreciated. 1335 */ 1336 else if (cmd == PRC_QUENCH) 1337 return; 1338 /* 1339 * Hostdead is ugly because it goes linearly through all PCBs. 1340 * XXX: We never get this from ICMP, otherwise it makes an 1341 * excellent DoS attack on machines with many connections. 1342 */ 1343 else if (cmd == PRC_HOSTDEAD) 1344 ip = NULL; 1345 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1346 return; 1347 if (ip != NULL) { 1348 icp = (struct icmp *)((caddr_t)ip 1349 - offsetof(struct icmp, icmp_ip)); 1350 th = (struct tcphdr *)((caddr_t)ip 1351 + (ip->ip_hl << 2)); 1352 INP_INFO_WLOCK(&V_tcbinfo); 1353 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport, 1354 ip->ip_src, th->th_sport, 0, NULL); 1355 if (inp != NULL) { 1356 INP_WLOCK(inp); 1357 if (!(inp->inp_flags & INP_TIMEWAIT) && 1358 !(inp->inp_flags & INP_DROPPED) && 1359 !(inp->inp_socket == NULL)) { 1360 icmp_tcp_seq = htonl(th->th_seq); 1361 tp = intotcpcb(inp); 1362 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1363 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1364 if (cmd == PRC_MSGSIZE) { 1365 /* 1366 * MTU discovery: 1367 * If we got a needfrag set the MTU 1368 * in the route to the suggested new 1369 * value (if given) and then notify. 1370 */ 1371 bzero(&inc, sizeof(inc)); 1372 inc.inc_faddr = faddr; 1373 inc.inc_fibnum = 1374 inp->inp_inc.inc_fibnum; 1375 1376 mtu = ntohs(icp->icmp_nextmtu); 1377 /* 1378 * If no alternative MTU was 1379 * proposed, try the next smaller 1380 * one. ip->ip_len has already 1381 * been swapped in icmp_input(). 1382 */ 1383 if (!mtu) 1384 mtu = ip_next_mtu(ip->ip_len, 1385 1); 1386 if (mtu < max(296, V_tcp_minmss 1387 + sizeof(struct tcpiphdr))) 1388 mtu = 0; 1389 if (!mtu) 1390 mtu = V_tcp_mssdflt 1391 + sizeof(struct tcpiphdr); 1392 /* 1393 * Only cache the the MTU if it 1394 * is smaller than the interface 1395 * or route MTU. tcp_mtudisc() 1396 * will do right thing by itself. 1397 */ 1398 if (mtu <= tcp_maxmtu(&inc, NULL)) 1399 tcp_hc_updatemtu(&inc, mtu); 1400 } 1401 1402 inp = (*notify)(inp, inetctlerrmap[cmd]); 1403 } 1404 } 1405 if (inp != NULL) 1406 INP_WUNLOCK(inp); 1407 } else { 1408 bzero(&inc, sizeof(inc)); 1409 inc.inc_fport = th->th_dport; 1410 inc.inc_lport = th->th_sport; 1411 inc.inc_faddr = faddr; 1412 inc.inc_laddr = ip->ip_src; 1413 syncache_unreach(&inc, th); 1414 } 1415 INP_INFO_WUNLOCK(&V_tcbinfo); 1416 } else 1417 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1418} 1419 1420#ifdef INET6 1421void 1422tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1423{ 1424 struct tcphdr th; 1425 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1426 struct ip6_hdr *ip6; 1427 struct mbuf *m; 1428 struct ip6ctlparam *ip6cp = NULL; 1429 const struct sockaddr_in6 *sa6_src = NULL; 1430 int off; 1431 struct tcp_portonly { 1432 u_int16_t th_sport; 1433 u_int16_t th_dport; 1434 } *thp; 1435 1436 if (sa->sa_family != AF_INET6 || 1437 sa->sa_len != sizeof(struct sockaddr_in6)) 1438 return; 1439 1440 if (cmd == PRC_MSGSIZE) 1441 notify = tcp_mtudisc; 1442 else if (!PRC_IS_REDIRECT(cmd) && 1443 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1444 return; 1445 /* Source quench is depreciated. */ 1446 else if (cmd == PRC_QUENCH) 1447 return; 1448 1449 /* if the parameter is from icmp6, decode it. */ 1450 if (d != NULL) { 1451 ip6cp = (struct ip6ctlparam *)d; 1452 m = ip6cp->ip6c_m; 1453 ip6 = ip6cp->ip6c_ip6; 1454 off = ip6cp->ip6c_off; 1455 sa6_src = ip6cp->ip6c_src; 1456 } else { 1457 m = NULL; 1458 ip6 = NULL; 1459 off = 0; /* fool gcc */ 1460 sa6_src = &sa6_any; 1461 } 1462 1463 if (ip6 != NULL) { 1464 struct in_conninfo inc; 1465 /* 1466 * XXX: We assume that when IPV6 is non NULL, 1467 * M and OFF are valid. 1468 */ 1469 1470 /* check if we can safely examine src and dst ports */ 1471 if (m->m_pkthdr.len < off + sizeof(*thp)) 1472 return; 1473 1474 bzero(&th, sizeof(th)); 1475 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1476 1477 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1478 (struct sockaddr *)ip6cp->ip6c_src, 1479 th.th_sport, cmd, NULL, notify); 1480 1481 bzero(&inc, sizeof(inc)); 1482 inc.inc_fport = th.th_dport; 1483 inc.inc_lport = th.th_sport; 1484 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1485 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1486 inc.inc_flags |= INC_ISIPV6; 1487 INP_INFO_WLOCK(&V_tcbinfo); 1488 syncache_unreach(&inc, &th); 1489 INP_INFO_WUNLOCK(&V_tcbinfo); 1490 } else 1491 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1492 0, cmd, NULL, notify); 1493} 1494#endif /* INET6 */ 1495 1496 1497/* 1498 * Following is where TCP initial sequence number generation occurs. 1499 * 1500 * There are two places where we must use initial sequence numbers: 1501 * 1. In SYN-ACK packets. 1502 * 2. In SYN packets. 1503 * 1504 * All ISNs for SYN-ACK packets are generated by the syncache. See 1505 * tcp_syncache.c for details. 1506 * 1507 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1508 * depends on this property. In addition, these ISNs should be 1509 * unguessable so as to prevent connection hijacking. To satisfy 1510 * the requirements of this situation, the algorithm outlined in 1511 * RFC 1948 is used, with only small modifications. 1512 * 1513 * Implementation details: 1514 * 1515 * Time is based off the system timer, and is corrected so that it 1516 * increases by one megabyte per second. This allows for proper 1517 * recycling on high speed LANs while still leaving over an hour 1518 * before rollover. 1519 * 1520 * As reading the *exact* system time is too expensive to be done 1521 * whenever setting up a TCP connection, we increment the time 1522 * offset in two ways. First, a small random positive increment 1523 * is added to isn_offset for each connection that is set up. 1524 * Second, the function tcp_isn_tick fires once per clock tick 1525 * and increments isn_offset as necessary so that sequence numbers 1526 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1527 * random positive increments serve only to ensure that the same 1528 * exact sequence number is never sent out twice (as could otherwise 1529 * happen when a port is recycled in less than the system tick 1530 * interval.) 1531 * 1532 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1533 * between seeding of isn_secret. This is normally set to zero, 1534 * as reseeding should not be necessary. 1535 * 1536 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1537 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1538 * general, this means holding an exclusive (write) lock. 1539 */ 1540 1541#define ISN_BYTES_PER_SECOND 1048576 1542#define ISN_STATIC_INCREMENT 4096 1543#define ISN_RANDOM_INCREMENT (4096 - 1) 1544 1545static VNET_DEFINE(u_char, isn_secret[32]); 1546static VNET_DEFINE(int, isn_last_reseed); 1547static VNET_DEFINE(u_int32_t, isn_offset); 1548static VNET_DEFINE(u_int32_t, isn_offset_old); 1549 1550#define V_isn_secret VNET(isn_secret) 1551#define V_isn_last_reseed VNET(isn_last_reseed) 1552#define V_isn_offset VNET(isn_offset) 1553#define V_isn_offset_old VNET(isn_offset_old) 1554 1555tcp_seq 1556tcp_new_isn(struct tcpcb *tp) 1557{ 1558 MD5_CTX isn_ctx; 1559 u_int32_t md5_buffer[4]; 1560 tcp_seq new_isn; 1561 1562 INP_WLOCK_ASSERT(tp->t_inpcb); 1563 1564 ISN_LOCK(); 1565 /* Seed if this is the first use, reseed if requested. */ 1566 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1567 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1568 < (u_int)ticks))) { 1569 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1570 V_isn_last_reseed = ticks; 1571 } 1572 1573 /* Compute the md5 hash and return the ISN. */ 1574 MD5Init(&isn_ctx); 1575 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1576 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1577#ifdef INET6 1578 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1579 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1580 sizeof(struct in6_addr)); 1581 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1582 sizeof(struct in6_addr)); 1583 } else 1584#endif 1585 { 1586 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1587 sizeof(struct in_addr)); 1588 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1589 sizeof(struct in_addr)); 1590 } 1591 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1592 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1593 new_isn = (tcp_seq) md5_buffer[0]; 1594 V_isn_offset += ISN_STATIC_INCREMENT + 1595 (arc4random() & ISN_RANDOM_INCREMENT); 1596 new_isn += V_isn_offset; 1597 ISN_UNLOCK(); 1598 return (new_isn); 1599} 1600 1601/* 1602 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary 1603 * to keep time flowing at a relatively constant rate. If the random 1604 * increments have already pushed us past the projected offset, do nothing. 1605 */ 1606static void 1607tcp_isn_tick(void *xtp) 1608{ 1609 VNET_ITERATOR_DECL(vnet_iter); 1610 u_int32_t projected_offset; 1611 1612 VNET_LIST_RLOCK_NOSLEEP(); 1613 ISN_LOCK(); 1614 VNET_FOREACH(vnet_iter) { 1615 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */ 1616 projected_offset = 1617 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100; 1618 1619 if (SEQ_GT(projected_offset, V_isn_offset)) 1620 V_isn_offset = projected_offset; 1621 1622 V_isn_offset_old = V_isn_offset; 1623 CURVNET_RESTORE(); 1624 } 1625 ISN_UNLOCK(); 1626 VNET_LIST_RUNLOCK_NOSLEEP(); 1627 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 1628} 1629 1630/* 1631 * When a specific ICMP unreachable message is received and the 1632 * connection state is SYN-SENT, drop the connection. This behavior 1633 * is controlled by the icmp_may_rst sysctl. 1634 */ 1635struct inpcb * 1636tcp_drop_syn_sent(struct inpcb *inp, int errno) 1637{ 1638 struct tcpcb *tp; 1639 1640 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1641 INP_WLOCK_ASSERT(inp); 1642 1643 if ((inp->inp_flags & INP_TIMEWAIT) || 1644 (inp->inp_flags & INP_DROPPED)) 1645 return (inp); 1646 1647 tp = intotcpcb(inp); 1648 if (tp->t_state != TCPS_SYN_SENT) 1649 return (inp); 1650 1651 tp = tcp_drop(tp, errno); 1652 if (tp != NULL) 1653 return (inp); 1654 else 1655 return (NULL); 1656} 1657 1658/* 1659 * When `need fragmentation' ICMP is received, update our idea of the MSS 1660 * based on the new value in the route. Also nudge TCP to send something, 1661 * since we know the packet we just sent was dropped. 1662 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1663 */ 1664struct inpcb * 1665tcp_mtudisc(struct inpcb *inp, int errno) 1666{ 1667 struct tcpcb *tp; 1668 struct socket *so; 1669 1670 INP_WLOCK_ASSERT(inp); 1671 if ((inp->inp_flags & INP_TIMEWAIT) || 1672 (inp->inp_flags & INP_DROPPED)) 1673 return (inp); 1674 1675 tp = intotcpcb(inp); 1676 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1677 1678 tcp_mss_update(tp, -1, NULL, NULL); 1679 1680 so = inp->inp_socket; 1681 SOCKBUF_LOCK(&so->so_snd); 1682 /* If the mss is larger than the socket buffer, decrease the mss. */ 1683 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1684 tp->t_maxseg = so->so_snd.sb_hiwat; 1685 SOCKBUF_UNLOCK(&so->so_snd); 1686 1687 TCPSTAT_INC(tcps_mturesent); 1688 tp->t_rtttime = 0; 1689 tp->snd_nxt = tp->snd_una; 1690 tcp_free_sackholes(tp); 1691 tp->snd_recover = tp->snd_max; 1692 if (tp->t_flags & TF_SACK_PERMIT) 1693 EXIT_FASTRECOVERY(tp); 1694 tcp_output_send(tp); 1695 return (inp); 1696} 1697 1698/* 1699 * Look-up the routing entry to the peer of this inpcb. If no route 1700 * is found and it cannot be allocated, then return 0. This routine 1701 * is called by TCP routines that access the rmx structure and by 1702 * tcp_mss_update to get the peer/interface MTU. 1703 */ 1704u_long 1705tcp_maxmtu(struct in_conninfo *inc, int *flags) 1706{ 1707 struct route sro; 1708 struct sockaddr_in *dst; 1709 struct ifnet *ifp; 1710 u_long maxmtu = 0; 1711 1712 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1713 1714 bzero(&sro, sizeof(sro)); 1715 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1716 dst = (struct sockaddr_in *)&sro.ro_dst; 1717 dst->sin_family = AF_INET; 1718 dst->sin_len = sizeof(*dst); 1719 dst->sin_addr = inc->inc_faddr; 1720 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1721 } 1722 if (sro.ro_rt != NULL) { 1723 ifp = sro.ro_rt->rt_ifp; 1724 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1725 maxmtu = ifp->if_mtu; 1726 else 1727 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1728 1729 /* Report additional interface capabilities. */ 1730 if (flags != NULL) { 1731 if (ifp->if_capenable & IFCAP_TSO4 && 1732 ifp->if_hwassist & CSUM_TSO) 1733 *flags |= CSUM_TSO; 1734 } 1735 RTFREE(sro.ro_rt); 1736 } 1737 return (maxmtu); 1738} 1739 1740#ifdef INET6 1741u_long 1742tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1743{ 1744 struct route_in6 sro6; 1745 struct ifnet *ifp; 1746 u_long maxmtu = 0; 1747 1748 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1749 1750 bzero(&sro6, sizeof(sro6)); 1751 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1752 sro6.ro_dst.sin6_family = AF_INET6; 1753 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1754 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1755 rtalloc_ign((struct route *)&sro6, 0); 1756 } 1757 if (sro6.ro_rt != NULL) { 1758 ifp = sro6.ro_rt->rt_ifp; 1759 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1760 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1761 else 1762 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1763 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1764 1765 /* Report additional interface capabilities. */ 1766 if (flags != NULL) { 1767 if (ifp->if_capenable & IFCAP_TSO6 && 1768 ifp->if_hwassist & CSUM_TSO) 1769 *flags |= CSUM_TSO; 1770 } 1771 RTFREE(sro6.ro_rt); 1772 } 1773 1774 return (maxmtu); 1775} 1776#endif /* INET6 */ 1777 1778#ifdef IPSEC 1779/* compute ESP/AH header size for TCP, including outer IP header. */ 1780size_t 1781ipsec_hdrsiz_tcp(struct tcpcb *tp) 1782{ 1783 struct inpcb *inp; 1784 struct mbuf *m; 1785 size_t hdrsiz; 1786 struct ip *ip; 1787#ifdef INET6 1788 struct ip6_hdr *ip6; 1789#endif 1790 struct tcphdr *th; 1791 1792 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1793 return (0); 1794 MGETHDR(m, M_DONTWAIT, MT_DATA); 1795 if (!m) 1796 return (0); 1797 1798#ifdef INET6 1799 if ((inp->inp_vflag & INP_IPV6) != 0) { 1800 ip6 = mtod(m, struct ip6_hdr *); 1801 th = (struct tcphdr *)(ip6 + 1); 1802 m->m_pkthdr.len = m->m_len = 1803 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1804 tcpip_fillheaders(inp, ip6, th); 1805 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1806 } else 1807#endif /* INET6 */ 1808 { 1809 ip = mtod(m, struct ip *); 1810 th = (struct tcphdr *)(ip + 1); 1811 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1812 tcpip_fillheaders(inp, ip, th); 1813 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1814 } 1815 1816 m_free(m); 1817 return (hdrsiz); 1818} 1819#endif /* IPSEC */ 1820 1821/* 1822 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1823 * 1824 * This code attempts to calculate the bandwidth-delay product as a 1825 * means of determining the optimal window size to maximize bandwidth, 1826 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1827 * routers. This code also does a fairly good job keeping RTTs in check 1828 * across slow links like modems. We implement an algorithm which is very 1829 * similar (but not meant to be) TCP/Vegas. The code operates on the 1830 * transmitter side of a TCP connection and so only effects the transmit 1831 * side of the connection. 1832 * 1833 * BACKGROUND: TCP makes no provision for the management of buffer space 1834 * at the end points or at the intermediate routers and switches. A TCP 1835 * stream, whether using NewReno or not, will eventually buffer as 1836 * many packets as it is able and the only reason this typically works is 1837 * due to the fairly small default buffers made available for a connection 1838 * (typicaly 16K or 32K). As machines use larger windows and/or window 1839 * scaling it is now fairly easy for even a single TCP connection to blow-out 1840 * all available buffer space not only on the local interface, but on 1841 * intermediate routers and switches as well. NewReno makes a misguided 1842 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1843 * then backing off, then steadily increasing the window again until another 1844 * failure occurs, ad-infinitum. This results in terrible oscillation that 1845 * is only made worse as network loads increase and the idea of intentionally 1846 * blowing out network buffers is, frankly, a terrible way to manage network 1847 * resources. 1848 * 1849 * It is far better to limit the transmit window prior to the failure 1850 * condition being achieved. There are two general ways to do this: First 1851 * you can 'scan' through different transmit window sizes and locate the 1852 * point where the RTT stops increasing, indicating that you have filled the 1853 * pipe, then scan backwards until you note that RTT stops decreasing, then 1854 * repeat ad-infinitum. This method works in principle but has severe 1855 * implementation issues due to RTT variances, timer granularity, and 1856 * instability in the algorithm which can lead to many false positives and 1857 * create oscillations as well as interact badly with other TCP streams 1858 * implementing the same algorithm. 1859 * 1860 * The second method is to limit the window to the bandwidth delay product 1861 * of the link. This is the method we implement. RTT variances and our 1862 * own manipulation of the congestion window, bwnd, can potentially 1863 * destabilize the algorithm. For this reason we have to stabilize the 1864 * elements used to calculate the window. We do this by using the minimum 1865 * observed RTT, the long term average of the observed bandwidth, and 1866 * by adding two segments worth of slop. It isn't perfect but it is able 1867 * to react to changing conditions and gives us a very stable basis on 1868 * which to extend the algorithm. 1869 */ 1870void 1871tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1872{ 1873 u_long bw; 1874 u_long bwnd; 1875 int save_ticks; 1876 1877 INP_WLOCK_ASSERT(tp->t_inpcb); 1878 1879 /* 1880 * If inflight_enable is disabled in the middle of a tcp connection, 1881 * make sure snd_bwnd is effectively disabled. 1882 */ 1883 if (V_tcp_inflight_enable == 0 || 1884 tp->t_rttlow < V_tcp_inflight_rttthresh) { 1885 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1886 tp->snd_bandwidth = 0; 1887 return; 1888 } 1889 1890 /* 1891 * Figure out the bandwidth. Due to the tick granularity this 1892 * is a very rough number and it MUST be averaged over a fairly 1893 * long period of time. XXX we need to take into account a link 1894 * that is not using all available bandwidth, but for now our 1895 * slop will ramp us up if this case occurs and the bandwidth later 1896 * increases. 1897 * 1898 * Note: if ticks rollover 'bw' may wind up negative. We must 1899 * effectively reset t_bw_rtttime for this case. 1900 */ 1901 save_ticks = ticks; 1902 if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1) 1903 return; 1904 1905 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / 1906 (save_ticks - tp->t_bw_rtttime); 1907 tp->t_bw_rtttime = save_ticks; 1908 tp->t_bw_rtseq = ack_seq; 1909 if (tp->t_bw_rtttime == 0 || (int)bw < 0) 1910 return; 1911 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1912 1913 tp->snd_bandwidth = bw; 1914 1915 /* 1916 * Calculate the semi-static bandwidth delay product, plus two maximal 1917 * segments. The additional slop puts us squarely in the sweet 1918 * spot and also handles the bandwidth run-up case and stabilization. 1919 * Without the slop we could be locking ourselves into a lower 1920 * bandwidth. 1921 * 1922 * Situations Handled: 1923 * (1) Prevents over-queueing of packets on LANs, especially on 1924 * high speed LANs, allowing larger TCP buffers to be 1925 * specified, and also does a good job preventing 1926 * over-queueing of packets over choke points like modems 1927 * (at least for the transmit side). 1928 * 1929 * (2) Is able to handle changing network loads (bandwidth 1930 * drops so bwnd drops, bandwidth increases so bwnd 1931 * increases). 1932 * 1933 * (3) Theoretically should stabilize in the face of multiple 1934 * connections implementing the same algorithm (this may need 1935 * a little work). 1936 * 1937 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1938 * be adjusted with a sysctl but typically only needs to be 1939 * on very slow connections. A value no smaller then 5 1940 * should be used, but only reduce this default if you have 1941 * no other choice. 1942 */ 1943#define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1944 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + V_tcp_inflight_stab * tp->t_maxseg / 10; 1945#undef USERTT 1946 1947 if (tcp_inflight_debug > 0) { 1948 static int ltime; 1949 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1950 ltime = ticks; 1951 printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1952 tp, 1953 bw, 1954 tp->t_rttbest, 1955 tp->t_srtt, 1956 bwnd 1957 ); 1958 } 1959 } 1960 if ((long)bwnd < V_tcp_inflight_min) 1961 bwnd = V_tcp_inflight_min; 1962 if (bwnd > V_tcp_inflight_max) 1963 bwnd = V_tcp_inflight_max; 1964 if ((long)bwnd < tp->t_maxseg * 2) 1965 bwnd = tp->t_maxseg * 2; 1966 tp->snd_bwnd = bwnd; 1967} 1968 1969#ifdef TCP_SIGNATURE 1970/* 1971 * Callback function invoked by m_apply() to digest TCP segment data 1972 * contained within an mbuf chain. 1973 */ 1974static int 1975tcp_signature_apply(void *fstate, void *data, u_int len) 1976{ 1977 1978 MD5Update(fstate, (u_char *)data, len); 1979 return (0); 1980} 1981 1982/* 1983 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1984 * 1985 * Parameters: 1986 * m pointer to head of mbuf chain 1987 * _unused 1988 * len length of TCP segment data, excluding options 1989 * optlen length of TCP segment options 1990 * buf pointer to storage for computed MD5 digest 1991 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1992 * 1993 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1994 * When called from tcp_input(), we can be sure that th_sum has been 1995 * zeroed out and verified already. 1996 * 1997 * Return 0 if successful, otherwise return -1. 1998 * 1999 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 2000 * search with the destination IP address, and a 'magic SPI' to be 2001 * determined by the application. This is hardcoded elsewhere to 1179 2002 * right now. Another branch of this code exists which uses the SPD to 2003 * specify per-application flows but it is unstable. 2004 */ 2005int 2006tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 2007 u_char *buf, u_int direction) 2008{ 2009 union sockaddr_union dst; 2010 struct ippseudo ippseudo; 2011 MD5_CTX ctx; 2012 int doff; 2013 struct ip *ip; 2014 struct ipovly *ipovly; 2015 struct secasvar *sav; 2016 struct tcphdr *th; 2017#ifdef INET6 2018 struct ip6_hdr *ip6; 2019 struct in6_addr in6; 2020 char ip6buf[INET6_ADDRSTRLEN]; 2021 uint32_t plen; 2022 uint16_t nhdr; 2023#endif 2024 u_short savecsum; 2025 2026 KASSERT(m != NULL, ("NULL mbuf chain")); 2027 KASSERT(buf != NULL, ("NULL signature pointer")); 2028 2029 /* Extract the destination from the IP header in the mbuf. */ 2030 bzero(&dst, sizeof(union sockaddr_union)); 2031 ip = mtod(m, struct ip *); 2032#ifdef INET6 2033 ip6 = NULL; /* Make the compiler happy. */ 2034#endif 2035 switch (ip->ip_v) { 2036 case IPVERSION: 2037 dst.sa.sa_len = sizeof(struct sockaddr_in); 2038 dst.sa.sa_family = AF_INET; 2039 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 2040 ip->ip_src : ip->ip_dst; 2041 break; 2042#ifdef INET6 2043 case (IPV6_VERSION >> 4): 2044 ip6 = mtod(m, struct ip6_hdr *); 2045 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2046 dst.sa.sa_family = AF_INET6; 2047 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2048 ip6->ip6_src : ip6->ip6_dst; 2049 break; 2050#endif 2051 default: 2052 return (EINVAL); 2053 /* NOTREACHED */ 2054 break; 2055 } 2056 2057 /* Look up an SADB entry which matches the address of the peer. */ 2058 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2059 if (sav == NULL) { 2060 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2061 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2062#ifdef INET6 2063 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2064 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2065#endif 2066 "(unsupported)")); 2067 return (EINVAL); 2068 } 2069 2070 MD5Init(&ctx); 2071 /* 2072 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2073 * 2074 * XXX The ippseudo header MUST be digested in network byte order, 2075 * or else we'll fail the regression test. Assume all fields we've 2076 * been doing arithmetic on have been in host byte order. 2077 * XXX One cannot depend on ipovly->ih_len here. When called from 2078 * tcp_output(), the underlying ip_len member has not yet been set. 2079 */ 2080 switch (ip->ip_v) { 2081 case IPVERSION: 2082 ipovly = (struct ipovly *)ip; 2083 ippseudo.ippseudo_src = ipovly->ih_src; 2084 ippseudo.ippseudo_dst = ipovly->ih_dst; 2085 ippseudo.ippseudo_pad = 0; 2086 ippseudo.ippseudo_p = IPPROTO_TCP; 2087 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2088 optlen); 2089 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2090 2091 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2092 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2093 break; 2094#ifdef INET6 2095 /* 2096 * RFC 2385, 2.0 Proposal 2097 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2098 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2099 * extended next header value (to form 32 bits), and 32-bit segment 2100 * length. 2101 * Note: Upper-Layer Packet Length comes before Next Header. 2102 */ 2103 case (IPV6_VERSION >> 4): 2104 in6 = ip6->ip6_src; 2105 in6_clearscope(&in6); 2106 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2107 in6 = ip6->ip6_dst; 2108 in6_clearscope(&in6); 2109 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2110 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2111 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2112 nhdr = 0; 2113 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2114 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2115 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2116 nhdr = IPPROTO_TCP; 2117 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2118 2119 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2120 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2121 break; 2122#endif 2123 default: 2124 return (EINVAL); 2125 /* NOTREACHED */ 2126 break; 2127 } 2128 2129 2130 /* 2131 * Step 2: Update MD5 hash with TCP header, excluding options. 2132 * The TCP checksum must be set to zero. 2133 */ 2134 savecsum = th->th_sum; 2135 th->th_sum = 0; 2136 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2137 th->th_sum = savecsum; 2138 2139 /* 2140 * Step 3: Update MD5 hash with TCP segment data. 2141 * Use m_apply() to avoid an early m_pullup(). 2142 */ 2143 if (len > 0) 2144 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2145 2146 /* 2147 * Step 4: Update MD5 hash with shared secret. 2148 */ 2149 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2150 MD5Final(buf, &ctx); 2151 2152 key_sa_recordxfer(sav, m); 2153 KEY_FREESAV(&sav); 2154 return (0); 2155} 2156#endif /* TCP_SIGNATURE */ 2157 2158static int 2159sysctl_drop(SYSCTL_HANDLER_ARGS) 2160{ 2161 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2162 struct sockaddr_storage addrs[2]; 2163 struct inpcb *inp; 2164 struct tcpcb *tp; 2165 struct tcptw *tw; 2166 struct sockaddr_in *fin, *lin; 2167#ifdef INET6 2168 struct sockaddr_in6 *fin6, *lin6; 2169#endif 2170 int error; 2171 2172 inp = NULL; 2173 fin = lin = NULL; 2174#ifdef INET6 2175 fin6 = lin6 = NULL; 2176#endif 2177 error = 0; 2178 2179 if (req->oldptr != NULL || req->oldlen != 0) 2180 return (EINVAL); 2181 if (req->newptr == NULL) 2182 return (EPERM); 2183 if (req->newlen < sizeof(addrs)) 2184 return (ENOMEM); 2185 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2186 if (error) 2187 return (error); 2188 2189 switch (addrs[0].ss_family) { 2190#ifdef INET6 2191 case AF_INET6: 2192 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2193 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2194 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2195 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2196 return (EINVAL); 2197 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2198 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2199 return (EINVAL); 2200 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2201 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2202 fin = (struct sockaddr_in *)&addrs[0]; 2203 lin = (struct sockaddr_in *)&addrs[1]; 2204 break; 2205 } 2206 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2207 if (error) 2208 return (error); 2209 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2210 if (error) 2211 return (error); 2212 break; 2213#endif 2214 case AF_INET: 2215 fin = (struct sockaddr_in *)&addrs[0]; 2216 lin = (struct sockaddr_in *)&addrs[1]; 2217 if (fin->sin_len != sizeof(struct sockaddr_in) || 2218 lin->sin_len != sizeof(struct sockaddr_in)) 2219 return (EINVAL); 2220 break; 2221 default: 2222 return (EINVAL); 2223 } 2224 INP_INFO_WLOCK(&V_tcbinfo); 2225 switch (addrs[0].ss_family) { 2226#ifdef INET6 2227 case AF_INET6: 2228 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr, 2229 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0, 2230 NULL); 2231 break; 2232#endif 2233 case AF_INET: 2234 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr, 2235 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL); 2236 break; 2237 } 2238 if (inp != NULL) { 2239 INP_WLOCK(inp); 2240 if (inp->inp_flags & INP_TIMEWAIT) { 2241 /* 2242 * XXXRW: There currently exists a state where an 2243 * inpcb is present, but its timewait state has been 2244 * discarded. For now, don't allow dropping of this 2245 * type of inpcb. 2246 */ 2247 tw = intotw(inp); 2248 if (tw != NULL) 2249 tcp_twclose(tw, 0); 2250 else 2251 INP_WUNLOCK(inp); 2252 } else if (!(inp->inp_flags & INP_DROPPED) && 2253 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2254 tp = intotcpcb(inp); 2255 tp = tcp_drop(tp, ECONNABORTED); 2256 if (tp != NULL) 2257 INP_WUNLOCK(inp); 2258 } else 2259 INP_WUNLOCK(inp); 2260 } else 2261 error = ESRCH; 2262 INP_INFO_WUNLOCK(&V_tcbinfo); 2263 return (error); 2264} 2265 2266SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2267 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2268 0, sysctl_drop, "", "Drop TCP connection"); 2269 2270/* 2271 * Generate a standardized TCP log line for use throughout the 2272 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2273 * allow use in the interrupt context. 2274 * 2275 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2276 * NB: The function may return NULL if memory allocation failed. 2277 * 2278 * Due to header inclusion and ordering limitations the struct ip 2279 * and ip6_hdr pointers have to be passed as void pointers. 2280 */ 2281char * 2282tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2283 const void *ip6hdr) 2284{ 2285 char *s, *sp; 2286 size_t size; 2287 struct ip *ip; 2288#ifdef INET6 2289 const struct ip6_hdr *ip6; 2290 2291 ip6 = (const struct ip6_hdr *)ip6hdr; 2292#endif /* INET6 */ 2293 ip = (struct ip *)ip4hdr; 2294 2295 /* 2296 * The log line looks like this: 2297 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2298 */ 2299 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2300 sizeof(PRINT_TH_FLAGS) + 1 + 2301#ifdef INET6 2302 2 * INET6_ADDRSTRLEN; 2303#else 2304 2 * INET_ADDRSTRLEN; 2305#endif /* INET6 */ 2306 2307 /* Is logging enabled? */ 2308 if (tcp_log_debug == 0 && tcp_log_in_vain == 0) 2309 return (NULL); 2310 2311 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2312 if (s == NULL) 2313 return (NULL); 2314 2315 strcat(s, "TCP: ["); 2316 sp = s + strlen(s); 2317 2318 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2319 inet_ntoa_r(inc->inc_faddr, sp); 2320 sp = s + strlen(s); 2321 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2322 sp = s + strlen(s); 2323 inet_ntoa_r(inc->inc_laddr, sp); 2324 sp = s + strlen(s); 2325 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2326#ifdef INET6 2327 } else if (inc) { 2328 ip6_sprintf(sp, &inc->inc6_faddr); 2329 sp = s + strlen(s); 2330 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2331 sp = s + strlen(s); 2332 ip6_sprintf(sp, &inc->inc6_laddr); 2333 sp = s + strlen(s); 2334 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2335 } else if (ip6 && th) { 2336 ip6_sprintf(sp, &ip6->ip6_src); 2337 sp = s + strlen(s); 2338 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2339 sp = s + strlen(s); 2340 ip6_sprintf(sp, &ip6->ip6_dst); 2341 sp = s + strlen(s); 2342 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2343#endif /* INET6 */ 2344 } else if (ip && th) { 2345 inet_ntoa_r(ip->ip_src, sp); 2346 sp = s + strlen(s); 2347 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2348 sp = s + strlen(s); 2349 inet_ntoa_r(ip->ip_dst, sp); 2350 sp = s + strlen(s); 2351 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2352 } else { 2353 free(s, M_TCPLOG); 2354 return (NULL); 2355 } 2356 sp = s + strlen(s); 2357 if (th) 2358 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2359 if (*(s + size - 1) != '\0') 2360 panic("%s: string too long", __func__); 2361 return (s); 2362}
| 354 V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole), 355 NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE); 356 357 /* Skip initialization of globals for non-default instances. */ 358 if (!IS_DEFAULT_VNET(curvnet)) 359 return; 360 361 /* XXX virtualize those bellow? */ 362 tcp_delacktime = TCPTV_DELACK; 363 tcp_keepinit = TCPTV_KEEP_INIT; 364 tcp_keepidle = TCPTV_KEEP_IDLE; 365 tcp_keepintvl = TCPTV_KEEPINTVL; 366 tcp_maxpersistidle = TCPTV_KEEP_IDLE; 367 tcp_msl = TCPTV_MSL; 368 tcp_rexmit_min = TCPTV_MIN; 369 if (tcp_rexmit_min < 1) 370 tcp_rexmit_min = 1; 371 tcp_rexmit_slop = TCPTV_CPU_VAR; 372 tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT; 373 tcp_tcbhashsize = hashsize; 374 375#ifdef TCP_SORECEIVE_STREAM 376 TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream); 377 if (tcp_soreceive_stream) { 378 tcp_usrreqs.pru_soreceive = soreceive_stream; 379 tcp6_usrreqs.pru_soreceive = soreceive_stream; 380 } 381#endif 382 383#ifdef INET6 384#define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) 385#else /* INET6 */ 386#define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) 387#endif /* INET6 */ 388 if (max_protohdr < TCP_MINPROTOHDR) 389 max_protohdr = TCP_MINPROTOHDR; 390 if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) 391 panic("tcp_init"); 392#undef TCP_MINPROTOHDR 393 394 ISN_LOCK_INIT(); 395 callout_init(&isn_callout, CALLOUT_MPSAFE); 396 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 397 EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL, 398 SHUTDOWN_PRI_DEFAULT); 399 EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL, 400 EVENTHANDLER_PRI_ANY); 401} 402 403#ifdef VIMAGE 404void 405tcp_destroy(void) 406{ 407 408 tcp_reass_destroy(); 409 tcp_hc_destroy(); 410 syncache_destroy(); 411 tcp_tw_destroy(); 412 in_pcbinfo_destroy(&V_tcbinfo); 413 uma_zdestroy(V_sack_hole_zone); 414 uma_zdestroy(V_tcpcb_zone); 415} 416#endif 417 418void 419tcp_fini(void *xtp) 420{ 421 422 callout_stop(&isn_callout); 423} 424 425/* 426 * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. 427 * tcp_template used to store this data in mbufs, but we now recopy it out 428 * of the tcpcb each time to conserve mbufs. 429 */ 430void 431tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr) 432{ 433 struct tcphdr *th = (struct tcphdr *)tcp_ptr; 434 435 INP_WLOCK_ASSERT(inp); 436 437#ifdef INET6 438 if ((inp->inp_vflag & INP_IPV6) != 0) { 439 struct ip6_hdr *ip6; 440 441 ip6 = (struct ip6_hdr *)ip_ptr; 442 ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | 443 (inp->inp_flow & IPV6_FLOWINFO_MASK); 444 ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | 445 (IPV6_VERSION & IPV6_VERSION_MASK); 446 ip6->ip6_nxt = IPPROTO_TCP; 447 ip6->ip6_plen = htons(sizeof(struct tcphdr)); 448 ip6->ip6_src = inp->in6p_laddr; 449 ip6->ip6_dst = inp->in6p_faddr; 450 } else 451#endif 452 { 453 struct ip *ip; 454 455 ip = (struct ip *)ip_ptr; 456 ip->ip_v = IPVERSION; 457 ip->ip_hl = 5; 458 ip->ip_tos = inp->inp_ip_tos; 459 ip->ip_len = 0; 460 ip->ip_id = 0; 461 ip->ip_off = 0; 462 ip->ip_ttl = inp->inp_ip_ttl; 463 ip->ip_sum = 0; 464 ip->ip_p = IPPROTO_TCP; 465 ip->ip_src = inp->inp_laddr; 466 ip->ip_dst = inp->inp_faddr; 467 } 468 th->th_sport = inp->inp_lport; 469 th->th_dport = inp->inp_fport; 470 th->th_seq = 0; 471 th->th_ack = 0; 472 th->th_x2 = 0; 473 th->th_off = 5; 474 th->th_flags = 0; 475 th->th_win = 0; 476 th->th_urp = 0; 477 th->th_sum = 0; /* in_pseudo() is called later for ipv4 */ 478} 479 480/* 481 * Create template to be used to send tcp packets on a connection. 482 * Allocates an mbuf and fills in a skeletal tcp/ip header. The only 483 * use for this function is in keepalives, which use tcp_respond. 484 */ 485struct tcptemp * 486tcpip_maketemplate(struct inpcb *inp) 487{ 488 struct tcptemp *t; 489 490 t = malloc(sizeof(*t), M_TEMP, M_NOWAIT); 491 if (t == NULL) 492 return (NULL); 493 tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t); 494 return (t); 495} 496 497/* 498 * Send a single message to the TCP at address specified by 499 * the given TCP/IP header. If m == NULL, then we make a copy 500 * of the tcpiphdr at ti and send directly to the addressed host. 501 * This is used to force keep alive messages out using the TCP 502 * template for a connection. If flags are given then we send 503 * a message back to the TCP which originated the * segment ti, 504 * and discard the mbuf containing it and any other attached mbufs. 505 * 506 * In any case the ack and sequence number of the transmitted 507 * segment are as specified by the parameters. 508 * 509 * NOTE: If m != NULL, then ti must point to *inside* the mbuf. 510 */ 511void 512tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, 513 tcp_seq ack, tcp_seq seq, int flags) 514{ 515 int tlen; 516 int win = 0; 517 struct ip *ip; 518 struct tcphdr *nth; 519#ifdef INET6 520 struct ip6_hdr *ip6; 521 int isipv6; 522#endif /* INET6 */ 523 int ipflags = 0; 524 struct inpcb *inp; 525 526 KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL")); 527 528#ifdef INET6 529 isipv6 = ((struct ip *)ipgen)->ip_v == 6; 530 ip6 = ipgen; 531#endif /* INET6 */ 532 ip = ipgen; 533 534 if (tp != NULL) { 535 inp = tp->t_inpcb; 536 KASSERT(inp != NULL, ("tcp control block w/o inpcb")); 537 INP_WLOCK_ASSERT(inp); 538 } else 539 inp = NULL; 540 541 if (tp != NULL) { 542 if (!(flags & TH_RST)) { 543 win = sbspace(&inp->inp_socket->so_rcv); 544 if (win > (long)TCP_MAXWIN << tp->rcv_scale) 545 win = (long)TCP_MAXWIN << tp->rcv_scale; 546 } 547 } 548 if (m == NULL) { 549 m = m_gethdr(M_DONTWAIT, MT_DATA); 550 if (m == NULL) 551 return; 552 tlen = 0; 553 m->m_data += max_linkhdr; 554#ifdef INET6 555 if (isipv6) { 556 bcopy((caddr_t)ip6, mtod(m, caddr_t), 557 sizeof(struct ip6_hdr)); 558 ip6 = mtod(m, struct ip6_hdr *); 559 nth = (struct tcphdr *)(ip6 + 1); 560 } else 561#endif /* INET6 */ 562 { 563 bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip)); 564 ip = mtod(m, struct ip *); 565 nth = (struct tcphdr *)(ip + 1); 566 } 567 bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr)); 568 flags = TH_ACK; 569 } else { 570 /* 571 * reuse the mbuf. 572 * XXX MRT We inherrit the FIB, which is lucky. 573 */ 574 m_freem(m->m_next); 575 m->m_next = NULL; 576 m->m_data = (caddr_t)ipgen; 577 /* m_len is set later */ 578 tlen = 0; 579#define xchg(a,b,type) { type t; t=a; a=b; b=t; } 580#ifdef INET6 581 if (isipv6) { 582 xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); 583 nth = (struct tcphdr *)(ip6 + 1); 584 } else 585#endif /* INET6 */ 586 { 587 xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t); 588 nth = (struct tcphdr *)(ip + 1); 589 } 590 if (th != nth) { 591 /* 592 * this is usually a case when an extension header 593 * exists between the IPv6 header and the 594 * TCP header. 595 */ 596 nth->th_sport = th->th_sport; 597 nth->th_dport = th->th_dport; 598 } 599 xchg(nth->th_dport, nth->th_sport, uint16_t); 600#undef xchg 601 } 602#ifdef INET6 603 if (isipv6) { 604 ip6->ip6_flow = 0; 605 ip6->ip6_vfc = IPV6_VERSION; 606 ip6->ip6_nxt = IPPROTO_TCP; 607 ip6->ip6_plen = htons((u_short)(sizeof (struct tcphdr) + 608 tlen)); 609 tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr); 610 } else 611#endif 612 { 613 tlen += sizeof (struct tcpiphdr); 614 ip->ip_len = tlen; 615 ip->ip_ttl = V_ip_defttl; 616 if (V_path_mtu_discovery) 617 ip->ip_off |= IP_DF; 618 } 619 m->m_len = tlen; 620 m->m_pkthdr.len = tlen; 621 m->m_pkthdr.rcvif = NULL; 622#ifdef MAC 623 if (inp != NULL) { 624 /* 625 * Packet is associated with a socket, so allow the 626 * label of the response to reflect the socket label. 627 */ 628 INP_WLOCK_ASSERT(inp); 629 mac_inpcb_create_mbuf(inp, m); 630 } else { 631 /* 632 * Packet is not associated with a socket, so possibly 633 * update the label in place. 634 */ 635 mac_netinet_tcp_reply(m); 636 } 637#endif 638 nth->th_seq = htonl(seq); 639 nth->th_ack = htonl(ack); 640 nth->th_x2 = 0; 641 nth->th_off = sizeof (struct tcphdr) >> 2; 642 nth->th_flags = flags; 643 if (tp != NULL) 644 nth->th_win = htons((u_short) (win >> tp->rcv_scale)); 645 else 646 nth->th_win = htons((u_short)win); 647 nth->th_urp = 0; 648#ifdef INET6 649 if (isipv6) { 650 nth->th_sum = 0; 651 nth->th_sum = in6_cksum(m, IPPROTO_TCP, 652 sizeof(struct ip6_hdr), 653 tlen - sizeof(struct ip6_hdr)); 654 ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb : 655 NULL, NULL); 656 } else 657#endif /* INET6 */ 658 { 659 nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, 660 htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); 661 m->m_pkthdr.csum_flags = CSUM_TCP; 662 m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); 663 } 664#ifdef TCPDEBUG 665 if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) 666 tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); 667#endif 668#ifdef INET6 669 if (isipv6) 670 (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp); 671 else 672#endif /* INET6 */ 673 (void) ip_output(m, NULL, NULL, ipflags, NULL, inp); 674} 675 676/* 677 * Create a new TCP control block, making an 678 * empty reassembly queue and hooking it to the argument 679 * protocol control block. The `inp' parameter must have 680 * come from the zone allocator set up in tcp_init(). 681 */ 682struct tcpcb * 683tcp_newtcpcb(struct inpcb *inp) 684{ 685 struct tcpcb_mem *tm; 686 struct tcpcb *tp; 687#ifdef INET6 688 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 689#endif /* INET6 */ 690 691 tm = uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO); 692 if (tm == NULL) 693 return (NULL); 694 tp = &tm->tcb; 695#ifdef VIMAGE 696 tp->t_vnet = inp->inp_vnet; 697#endif 698 tp->t_timers = &tm->tt; 699 /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */ 700 tp->t_maxseg = tp->t_maxopd = 701#ifdef INET6 702 isipv6 ? V_tcp_v6mssdflt : 703#endif /* INET6 */ 704 V_tcp_mssdflt; 705 706 /* Set up our timeouts. */ 707 callout_init(&tp->t_timers->tt_rexmt, CALLOUT_MPSAFE); 708 callout_init(&tp->t_timers->tt_persist, CALLOUT_MPSAFE); 709 callout_init(&tp->t_timers->tt_keep, CALLOUT_MPSAFE); 710 callout_init(&tp->t_timers->tt_2msl, CALLOUT_MPSAFE); 711 callout_init(&tp->t_timers->tt_delack, CALLOUT_MPSAFE); 712 713 if (V_tcp_do_rfc1323) 714 tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); 715 if (V_tcp_do_sack) 716 tp->t_flags |= TF_SACK_PERMIT; 717 TAILQ_INIT(&tp->snd_holes); 718 tp->t_inpcb = inp; /* XXX */ 719 /* 720 * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no 721 * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives 722 * reasonable initial retransmit time. 723 */ 724 tp->t_srtt = TCPTV_SRTTBASE; 725 tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; 726 tp->t_rttmin = tcp_rexmit_min; 727 tp->t_rxtcur = TCPTV_RTOBASE; 728 tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 729 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 730 tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; 731 tp->t_rcvtime = ticks; 732 tp->t_bw_rtttime = ticks; 733 /* 734 * IPv4 TTL initialization is necessary for an IPv6 socket as well, 735 * because the socket may be bound to an IPv6 wildcard address, 736 * which may match an IPv4-mapped IPv6 address. 737 */ 738 inp->inp_ip_ttl = V_ip_defttl; 739 inp->inp_ppcb = tp; 740 return (tp); /* XXX */ 741} 742 743/* 744 * Drop a TCP connection, reporting 745 * the specified error. If connection is synchronized, 746 * then send a RST to peer. 747 */ 748struct tcpcb * 749tcp_drop(struct tcpcb *tp, int errno) 750{ 751 struct socket *so = tp->t_inpcb->inp_socket; 752 753 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 754 INP_WLOCK_ASSERT(tp->t_inpcb); 755 756 if (TCPS_HAVERCVDSYN(tp->t_state)) { 757 tp->t_state = TCPS_CLOSED; 758 (void) tcp_output_reset(tp); 759 TCPSTAT_INC(tcps_drops); 760 } else 761 TCPSTAT_INC(tcps_conndrops); 762 if (errno == ETIMEDOUT && tp->t_softerror) 763 errno = tp->t_softerror; 764 so->so_error = errno; 765 return (tcp_close(tp)); 766} 767 768void 769tcp_discardcb(struct tcpcb *tp) 770{ 771 struct tseg_qent *q; 772 struct inpcb *inp = tp->t_inpcb; 773 struct socket *so = inp->inp_socket; 774#ifdef INET6 775 int isipv6 = (inp->inp_vflag & INP_IPV6) != 0; 776#endif /* INET6 */ 777 778 INP_WLOCK_ASSERT(inp); 779 780 /* 781 * Make sure that all of our timers are stopped before we delete the 782 * PCB. 783 * 784 * XXXRW: Really, we would like to use callout_drain() here in order 785 * to avoid races experienced in tcp_timer.c where a timer is already 786 * executing at this point. However, we can't, both because we're 787 * running in a context where we can't sleep, and also because we 788 * hold locks required by the timers. What we instead need to do is 789 * test to see if callout_drain() is required, and if so, defer some 790 * portion of the remainder of tcp_discardcb() to an asynchronous 791 * context that can callout_drain() and then continue. Some care 792 * will be required to ensure that no further processing takes place 793 * on the tcpcb, even though it hasn't been freed (a flag?). 794 */ 795 callout_stop(&tp->t_timers->tt_rexmt); 796 callout_stop(&tp->t_timers->tt_persist); 797 callout_stop(&tp->t_timers->tt_keep); 798 callout_stop(&tp->t_timers->tt_2msl); 799 callout_stop(&tp->t_timers->tt_delack); 800 801 /* 802 * If we got enough samples through the srtt filter, 803 * save the rtt and rttvar in the routing entry. 804 * 'Enough' is arbitrarily defined as 4 rtt samples. 805 * 4 samples is enough for the srtt filter to converge 806 * to within enough % of the correct value; fewer samples 807 * and we could save a bogus rtt. The danger is not high 808 * as tcp quickly recovers from everything. 809 * XXX: Works very well but needs some more statistics! 810 */ 811 if (tp->t_rttupdated >= 4) { 812 struct hc_metrics_lite metrics; 813 u_long ssthresh; 814 815 bzero(&metrics, sizeof(metrics)); 816 /* 817 * Update the ssthresh always when the conditions below 818 * are satisfied. This gives us better new start value 819 * for the congestion avoidance for new connections. 820 * ssthresh is only set if packet loss occured on a session. 821 * 822 * XXXRW: 'so' may be NULL here, and/or socket buffer may be 823 * being torn down. Ideally this code would not use 'so'. 824 */ 825 ssthresh = tp->snd_ssthresh; 826 if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) { 827 /* 828 * convert the limit from user data bytes to 829 * packets then to packet data bytes. 830 */ 831 ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg; 832 if (ssthresh < 2) 833 ssthresh = 2; 834 ssthresh *= (u_long)(tp->t_maxseg + 835#ifdef INET6 836 (isipv6 ? sizeof (struct ip6_hdr) + 837 sizeof (struct tcphdr) : 838#endif 839 sizeof (struct tcpiphdr) 840#ifdef INET6 841 ) 842#endif 843 ); 844 } else 845 ssthresh = 0; 846 metrics.rmx_ssthresh = ssthresh; 847 848 metrics.rmx_rtt = tp->t_srtt; 849 metrics.rmx_rttvar = tp->t_rttvar; 850 /* XXX: This wraps if the pipe is more than 4 Gbit per second */ 851 metrics.rmx_bandwidth = tp->snd_bandwidth; 852 metrics.rmx_cwnd = tp->snd_cwnd; 853 metrics.rmx_sendpipe = 0; 854 metrics.rmx_recvpipe = 0; 855 856 tcp_hc_update(&inp->inp_inc, &metrics); 857 } 858 859 /* free the reassembly queue, if any */ 860 while ((q = LIST_FIRST(&tp->t_segq)) != NULL) { 861 LIST_REMOVE(q, tqe_q); 862 m_freem(q->tqe_m); 863 uma_zfree(V_tcp_reass_zone, q); 864 tp->t_segqlen--; 865 V_tcp_reass_qsize--; 866 } 867 /* Disconnect offload device, if any. */ 868 tcp_offload_detach(tp); 869 870 tcp_free_sackholes(tp); 871 inp->inp_ppcb = NULL; 872 tp->t_inpcb = NULL; 873 uma_zfree(V_tcpcb_zone, tp); 874} 875 876/* 877 * Attempt to close a TCP control block, marking it as dropped, and freeing 878 * the socket if we hold the only reference. 879 */ 880struct tcpcb * 881tcp_close(struct tcpcb *tp) 882{ 883 struct inpcb *inp = tp->t_inpcb; 884 struct socket *so; 885 886 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 887 INP_WLOCK_ASSERT(inp); 888 889 /* Notify any offload devices of listener close */ 890 if (tp->t_state == TCPS_LISTEN) 891 tcp_offload_listen_close(tp); 892 in_pcbdrop(inp); 893 TCPSTAT_INC(tcps_closed); 894 KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL")); 895 so = inp->inp_socket; 896 soisdisconnected(so); 897 if (inp->inp_flags & INP_SOCKREF) { 898 KASSERT(so->so_state & SS_PROTOREF, 899 ("tcp_close: !SS_PROTOREF")); 900 inp->inp_flags &= ~INP_SOCKREF; 901 INP_WUNLOCK(inp); 902 ACCEPT_LOCK(); 903 SOCK_LOCK(so); 904 so->so_state &= ~SS_PROTOREF; 905 sofree(so); 906 return (NULL); 907 } 908 return (tp); 909} 910 911void 912tcp_drain(void) 913{ 914 VNET_ITERATOR_DECL(vnet_iter); 915 916 if (!do_tcpdrain) 917 return; 918 919 VNET_LIST_RLOCK_NOSLEEP(); 920 VNET_FOREACH(vnet_iter) { 921 CURVNET_SET(vnet_iter); 922 struct inpcb *inpb; 923 struct tcpcb *tcpb; 924 struct tseg_qent *te; 925 926 /* 927 * Walk the tcpbs, if existing, and flush the reassembly queue, 928 * if there is one... 929 * XXX: The "Net/3" implementation doesn't imply that the TCP 930 * reassembly queue should be flushed, but in a situation 931 * where we're really low on mbufs, this is potentially 932 * usefull. 933 */ 934 INP_INFO_RLOCK(&V_tcbinfo); 935 LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) { 936 if (inpb->inp_flags & INP_TIMEWAIT) 937 continue; 938 INP_WLOCK(inpb); 939 if ((tcpb = intotcpcb(inpb)) != NULL) { 940 while ((te = LIST_FIRST(&tcpb->t_segq)) 941 != NULL) { 942 LIST_REMOVE(te, tqe_q); 943 m_freem(te->tqe_m); 944 uma_zfree(V_tcp_reass_zone, te); 945 tcpb->t_segqlen--; 946 V_tcp_reass_qsize--; 947 } 948 tcp_clean_sackreport(tcpb); 949 } 950 INP_WUNLOCK(inpb); 951 } 952 INP_INFO_RUNLOCK(&V_tcbinfo); 953 CURVNET_RESTORE(); 954 } 955 VNET_LIST_RUNLOCK_NOSLEEP(); 956} 957 958/* 959 * Notify a tcp user of an asynchronous error; 960 * store error as soft error, but wake up user 961 * (for now, won't do anything until can select for soft error). 962 * 963 * Do not wake up user since there currently is no mechanism for 964 * reporting soft errors (yet - a kqueue filter may be added). 965 */ 966static struct inpcb * 967tcp_notify(struct inpcb *inp, int error) 968{ 969 struct tcpcb *tp; 970 971 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 972 INP_WLOCK_ASSERT(inp); 973 974 if ((inp->inp_flags & INP_TIMEWAIT) || 975 (inp->inp_flags & INP_DROPPED)) 976 return (inp); 977 978 tp = intotcpcb(inp); 979 KASSERT(tp != NULL, ("tcp_notify: tp == NULL")); 980 981 /* 982 * Ignore some errors if we are hooked up. 983 * If connection hasn't completed, has retransmitted several times, 984 * and receives a second error, give up now. This is better 985 * than waiting a long time to establish a connection that 986 * can never complete. 987 */ 988 if (tp->t_state == TCPS_ESTABLISHED && 989 (error == EHOSTUNREACH || error == ENETUNREACH || 990 error == EHOSTDOWN)) { 991 return (inp); 992 } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && 993 tp->t_softerror) { 994 tp = tcp_drop(tp, error); 995 if (tp != NULL) 996 return (inp); 997 else 998 return (NULL); 999 } else { 1000 tp->t_softerror = error; 1001 return (inp); 1002 } 1003#if 0 1004 wakeup( &so->so_timeo); 1005 sorwakeup(so); 1006 sowwakeup(so); 1007#endif 1008} 1009 1010static int 1011tcp_pcblist(SYSCTL_HANDLER_ARGS) 1012{ 1013 int error, i, m, n, pcb_count; 1014 struct inpcb *inp, **inp_list; 1015 inp_gen_t gencnt; 1016 struct xinpgen xig; 1017 1018 /* 1019 * The process of preparing the TCB list is too time-consuming and 1020 * resource-intensive to repeat twice on every request. 1021 */ 1022 if (req->oldptr == NULL) { 1023 m = syncache_pcbcount(); 1024 n = V_tcbinfo.ipi_count; 1025 req->oldidx = 2 * (sizeof xig) 1026 + ((m + n) + n/8) * sizeof(struct xtcpcb); 1027 return (0); 1028 } 1029 1030 if (req->newptr != NULL) 1031 return (EPERM); 1032 1033 /* 1034 * OK, now we're committed to doing something. 1035 */ 1036 INP_INFO_RLOCK(&V_tcbinfo); 1037 gencnt = V_tcbinfo.ipi_gencnt; 1038 n = V_tcbinfo.ipi_count; 1039 INP_INFO_RUNLOCK(&V_tcbinfo); 1040 1041 m = syncache_pcbcount(); 1042 1043 error = sysctl_wire_old_buffer(req, 2 * (sizeof xig) 1044 + (n + m) * sizeof(struct xtcpcb)); 1045 if (error != 0) 1046 return (error); 1047 1048 xig.xig_len = sizeof xig; 1049 xig.xig_count = n + m; 1050 xig.xig_gen = gencnt; 1051 xig.xig_sogen = so_gencnt; 1052 error = SYSCTL_OUT(req, &xig, sizeof xig); 1053 if (error) 1054 return (error); 1055 1056 error = syncache_pcblist(req, m, &pcb_count); 1057 if (error) 1058 return (error); 1059 1060 inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK); 1061 if (inp_list == NULL) 1062 return (ENOMEM); 1063 1064 INP_INFO_RLOCK(&V_tcbinfo); 1065 for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0; 1066 inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) { 1067 INP_WLOCK(inp); 1068 if (inp->inp_gencnt <= gencnt) { 1069 /* 1070 * XXX: This use of cr_cansee(), introduced with 1071 * TCP state changes, is not quite right, but for 1072 * now, better than nothing. 1073 */ 1074 if (inp->inp_flags & INP_TIMEWAIT) { 1075 if (intotw(inp) != NULL) 1076 error = cr_cansee(req->td->td_ucred, 1077 intotw(inp)->tw_cred); 1078 else 1079 error = EINVAL; /* Skip this inp. */ 1080 } else 1081 error = cr_canseeinpcb(req->td->td_ucred, inp); 1082 if (error == 0) { 1083 in_pcbref(inp); 1084 inp_list[i++] = inp; 1085 } 1086 } 1087 INP_WUNLOCK(inp); 1088 } 1089 INP_INFO_RUNLOCK(&V_tcbinfo); 1090 n = i; 1091 1092 error = 0; 1093 for (i = 0; i < n; i++) { 1094 inp = inp_list[i]; 1095 INP_RLOCK(inp); 1096 if (inp->inp_gencnt <= gencnt) { 1097 struct xtcpcb xt; 1098 void *inp_ppcb; 1099 1100 bzero(&xt, sizeof(xt)); 1101 xt.xt_len = sizeof xt; 1102 /* XXX should avoid extra copy */ 1103 bcopy(inp, &xt.xt_inp, sizeof *inp); 1104 inp_ppcb = inp->inp_ppcb; 1105 if (inp_ppcb == NULL) 1106 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1107 else if (inp->inp_flags & INP_TIMEWAIT) { 1108 bzero((char *) &xt.xt_tp, sizeof xt.xt_tp); 1109 xt.xt_tp.t_state = TCPS_TIME_WAIT; 1110 } else { 1111 bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); 1112 if (xt.xt_tp.t_timers) 1113 tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer); 1114 } 1115 if (inp->inp_socket != NULL) 1116 sotoxsocket(inp->inp_socket, &xt.xt_socket); 1117 else { 1118 bzero(&xt.xt_socket, sizeof xt.xt_socket); 1119 xt.xt_socket.xso_protocol = IPPROTO_TCP; 1120 } 1121 xt.xt_inp.inp_gencnt = inp->inp_gencnt; 1122 INP_RUNLOCK(inp); 1123 error = SYSCTL_OUT(req, &xt, sizeof xt); 1124 } else 1125 INP_RUNLOCK(inp); 1126 } 1127 INP_INFO_WLOCK(&V_tcbinfo); 1128 for (i = 0; i < n; i++) { 1129 inp = inp_list[i]; 1130 INP_WLOCK(inp); 1131 if (!in_pcbrele(inp)) 1132 INP_WUNLOCK(inp); 1133 } 1134 INP_INFO_WUNLOCK(&V_tcbinfo); 1135 1136 if (!error) { 1137 /* 1138 * Give the user an updated idea of our state. 1139 * If the generation differs from what we told 1140 * her before, she knows that something happened 1141 * while we were processing this request, and it 1142 * might be necessary to retry. 1143 */ 1144 INP_INFO_RLOCK(&V_tcbinfo); 1145 xig.xig_gen = V_tcbinfo.ipi_gencnt; 1146 xig.xig_sogen = so_gencnt; 1147 xig.xig_count = V_tcbinfo.ipi_count + pcb_count; 1148 INP_INFO_RUNLOCK(&V_tcbinfo); 1149 error = SYSCTL_OUT(req, &xig, sizeof xig); 1150 } 1151 free(inp_list, M_TEMP); 1152 return (error); 1153} 1154 1155SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, 1156 tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); 1157 1158static int 1159tcp_getcred(SYSCTL_HANDLER_ARGS) 1160{ 1161 struct xucred xuc; 1162 struct sockaddr_in addrs[2]; 1163 struct inpcb *inp; 1164 int error; 1165 1166 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1167 if (error) 1168 return (error); 1169 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1170 if (error) 1171 return (error); 1172 INP_INFO_RLOCK(&V_tcbinfo); 1173 inp = in_pcblookup_hash(&V_tcbinfo, addrs[1].sin_addr, 1174 addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); 1175 if (inp != NULL) { 1176 INP_RLOCK(inp); 1177 INP_INFO_RUNLOCK(&V_tcbinfo); 1178 if (inp->inp_socket == NULL) 1179 error = ENOENT; 1180 if (error == 0) 1181 error = cr_canseeinpcb(req->td->td_ucred, inp); 1182 if (error == 0) 1183 cru2x(inp->inp_cred, &xuc); 1184 INP_RUNLOCK(inp); 1185 } else { 1186 INP_INFO_RUNLOCK(&V_tcbinfo); 1187 error = ENOENT; 1188 } 1189 if (error == 0) 1190 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1191 return (error); 1192} 1193 1194SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, 1195 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1196 tcp_getcred, "S,xucred", "Get the xucred of a TCP connection"); 1197 1198#ifdef INET6 1199static int 1200tcp6_getcred(SYSCTL_HANDLER_ARGS) 1201{ 1202 struct xucred xuc; 1203 struct sockaddr_in6 addrs[2]; 1204 struct inpcb *inp; 1205 int error, mapped = 0; 1206 1207 error = priv_check(req->td, PRIV_NETINET_GETCRED); 1208 if (error) 1209 return (error); 1210 error = SYSCTL_IN(req, addrs, sizeof(addrs)); 1211 if (error) 1212 return (error); 1213 if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 || 1214 (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) { 1215 return (error); 1216 } 1217 if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) { 1218 if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr)) 1219 mapped = 1; 1220 else 1221 return (EINVAL); 1222 } 1223 1224 INP_INFO_RLOCK(&V_tcbinfo); 1225 if (mapped == 1) 1226 inp = in_pcblookup_hash(&V_tcbinfo, 1227 *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12], 1228 addrs[1].sin6_port, 1229 *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12], 1230 addrs[0].sin6_port, 1231 0, NULL); 1232 else 1233 inp = in6_pcblookup_hash(&V_tcbinfo, 1234 &addrs[1].sin6_addr, addrs[1].sin6_port, 1235 &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); 1236 if (inp != NULL) { 1237 INP_RLOCK(inp); 1238 INP_INFO_RUNLOCK(&V_tcbinfo); 1239 if (inp->inp_socket == NULL) 1240 error = ENOENT; 1241 if (error == 0) 1242 error = cr_canseeinpcb(req->td->td_ucred, inp); 1243 if (error == 0) 1244 cru2x(inp->inp_cred, &xuc); 1245 INP_RUNLOCK(inp); 1246 } else { 1247 INP_INFO_RUNLOCK(&V_tcbinfo); 1248 error = ENOENT; 1249 } 1250 if (error == 0) 1251 error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred)); 1252 return (error); 1253} 1254 1255SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, 1256 CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0, 1257 tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection"); 1258#endif 1259 1260 1261void 1262tcp_ctlinput(int cmd, struct sockaddr *sa, void *vip) 1263{ 1264 struct ip *ip = vip; 1265 struct tcphdr *th; 1266 struct in_addr faddr; 1267 struct inpcb *inp; 1268 struct tcpcb *tp; 1269 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1270 struct icmp *icp; 1271 struct in_conninfo inc; 1272 tcp_seq icmp_tcp_seq; 1273 int mtu; 1274 1275 faddr = ((struct sockaddr_in *)sa)->sin_addr; 1276 if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) 1277 return; 1278 1279 if (cmd == PRC_MSGSIZE) 1280 notify = tcp_mtudisc; 1281 else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || 1282 cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip) 1283 notify = tcp_drop_syn_sent; 1284 /* 1285 * Redirects don't need to be handled up here. 1286 */ 1287 else if (PRC_IS_REDIRECT(cmd)) 1288 return; 1289 /* 1290 * Source quench is depreciated. 1291 */ 1292 else if (cmd == PRC_QUENCH) 1293 return; 1294 /* 1295 * Hostdead is ugly because it goes linearly through all PCBs. 1296 * XXX: We never get this from ICMP, otherwise it makes an 1297 * excellent DoS attack on machines with many connections. 1298 */ 1299 else if (cmd == PRC_HOSTDEAD) 1300 ip = NULL; 1301 else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) 1302 return; 1303 if (ip != NULL) { 1304 icp = (struct icmp *)((caddr_t)ip 1305 - offsetof(struct icmp, icmp_ip)); 1306 th = (struct tcphdr *)((caddr_t)ip 1307 + (ip->ip_hl << 2)); 1308 INP_INFO_WLOCK(&V_tcbinfo); 1309 inp = in_pcblookup_hash(&V_tcbinfo, faddr, th->th_dport, 1310 ip->ip_src, th->th_sport, 0, NULL); 1311 if (inp != NULL) { 1312 INP_WLOCK(inp); 1313 if (!(inp->inp_flags & INP_TIMEWAIT) && 1314 !(inp->inp_flags & INP_DROPPED) && 1315 !(inp->inp_socket == NULL)) { 1316 icmp_tcp_seq = htonl(th->th_seq); 1317 tp = intotcpcb(inp); 1318 if (SEQ_GEQ(icmp_tcp_seq, tp->snd_una) && 1319 SEQ_LT(icmp_tcp_seq, tp->snd_max)) { 1320 if (cmd == PRC_MSGSIZE) { 1321 /* 1322 * MTU discovery: 1323 * If we got a needfrag set the MTU 1324 * in the route to the suggested new 1325 * value (if given) and then notify. 1326 */ 1327 bzero(&inc, sizeof(inc)); 1328 inc.inc_faddr = faddr; 1329 inc.inc_fibnum = 1330 inp->inp_inc.inc_fibnum; 1331 1332 mtu = ntohs(icp->icmp_nextmtu); 1333 /* 1334 * If no alternative MTU was 1335 * proposed, try the next smaller 1336 * one. ip->ip_len has already 1337 * been swapped in icmp_input(). 1338 */ 1339 if (!mtu) 1340 mtu = ip_next_mtu(ip->ip_len, 1341 1); 1342 if (mtu < max(296, V_tcp_minmss 1343 + sizeof(struct tcpiphdr))) 1344 mtu = 0; 1345 if (!mtu) 1346 mtu = V_tcp_mssdflt 1347 + sizeof(struct tcpiphdr); 1348 /* 1349 * Only cache the the MTU if it 1350 * is smaller than the interface 1351 * or route MTU. tcp_mtudisc() 1352 * will do right thing by itself. 1353 */ 1354 if (mtu <= tcp_maxmtu(&inc, NULL)) 1355 tcp_hc_updatemtu(&inc, mtu); 1356 } 1357 1358 inp = (*notify)(inp, inetctlerrmap[cmd]); 1359 } 1360 } 1361 if (inp != NULL) 1362 INP_WUNLOCK(inp); 1363 } else { 1364 bzero(&inc, sizeof(inc)); 1365 inc.inc_fport = th->th_dport; 1366 inc.inc_lport = th->th_sport; 1367 inc.inc_faddr = faddr; 1368 inc.inc_laddr = ip->ip_src; 1369 syncache_unreach(&inc, th); 1370 } 1371 INP_INFO_WUNLOCK(&V_tcbinfo); 1372 } else 1373 in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify); 1374} 1375 1376#ifdef INET6 1377void 1378tcp6_ctlinput(int cmd, struct sockaddr *sa, void *d) 1379{ 1380 struct tcphdr th; 1381 struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify; 1382 struct ip6_hdr *ip6; 1383 struct mbuf *m; 1384 struct ip6ctlparam *ip6cp = NULL; 1385 const struct sockaddr_in6 *sa6_src = NULL; 1386 int off; 1387 struct tcp_portonly { 1388 u_int16_t th_sport; 1389 u_int16_t th_dport; 1390 } *thp; 1391 1392 if (sa->sa_family != AF_INET6 || 1393 sa->sa_len != sizeof(struct sockaddr_in6)) 1394 return; 1395 1396 if (cmd == PRC_MSGSIZE) 1397 notify = tcp_mtudisc; 1398 else if (!PRC_IS_REDIRECT(cmd) && 1399 ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) 1400 return; 1401 /* Source quench is depreciated. */ 1402 else if (cmd == PRC_QUENCH) 1403 return; 1404 1405 /* if the parameter is from icmp6, decode it. */ 1406 if (d != NULL) { 1407 ip6cp = (struct ip6ctlparam *)d; 1408 m = ip6cp->ip6c_m; 1409 ip6 = ip6cp->ip6c_ip6; 1410 off = ip6cp->ip6c_off; 1411 sa6_src = ip6cp->ip6c_src; 1412 } else { 1413 m = NULL; 1414 ip6 = NULL; 1415 off = 0; /* fool gcc */ 1416 sa6_src = &sa6_any; 1417 } 1418 1419 if (ip6 != NULL) { 1420 struct in_conninfo inc; 1421 /* 1422 * XXX: We assume that when IPV6 is non NULL, 1423 * M and OFF are valid. 1424 */ 1425 1426 /* check if we can safely examine src and dst ports */ 1427 if (m->m_pkthdr.len < off + sizeof(*thp)) 1428 return; 1429 1430 bzero(&th, sizeof(th)); 1431 m_copydata(m, off, sizeof(*thp), (caddr_t)&th); 1432 1433 in6_pcbnotify(&V_tcbinfo, sa, th.th_dport, 1434 (struct sockaddr *)ip6cp->ip6c_src, 1435 th.th_sport, cmd, NULL, notify); 1436 1437 bzero(&inc, sizeof(inc)); 1438 inc.inc_fport = th.th_dport; 1439 inc.inc_lport = th.th_sport; 1440 inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; 1441 inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; 1442 inc.inc_flags |= INC_ISIPV6; 1443 INP_INFO_WLOCK(&V_tcbinfo); 1444 syncache_unreach(&inc, &th); 1445 INP_INFO_WUNLOCK(&V_tcbinfo); 1446 } else 1447 in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct sockaddr *)sa6_src, 1448 0, cmd, NULL, notify); 1449} 1450#endif /* INET6 */ 1451 1452 1453/* 1454 * Following is where TCP initial sequence number generation occurs. 1455 * 1456 * There are two places where we must use initial sequence numbers: 1457 * 1. In SYN-ACK packets. 1458 * 2. In SYN packets. 1459 * 1460 * All ISNs for SYN-ACK packets are generated by the syncache. See 1461 * tcp_syncache.c for details. 1462 * 1463 * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling 1464 * depends on this property. In addition, these ISNs should be 1465 * unguessable so as to prevent connection hijacking. To satisfy 1466 * the requirements of this situation, the algorithm outlined in 1467 * RFC 1948 is used, with only small modifications. 1468 * 1469 * Implementation details: 1470 * 1471 * Time is based off the system timer, and is corrected so that it 1472 * increases by one megabyte per second. This allows for proper 1473 * recycling on high speed LANs while still leaving over an hour 1474 * before rollover. 1475 * 1476 * As reading the *exact* system time is too expensive to be done 1477 * whenever setting up a TCP connection, we increment the time 1478 * offset in two ways. First, a small random positive increment 1479 * is added to isn_offset for each connection that is set up. 1480 * Second, the function tcp_isn_tick fires once per clock tick 1481 * and increments isn_offset as necessary so that sequence numbers 1482 * are incremented at approximately ISN_BYTES_PER_SECOND. The 1483 * random positive increments serve only to ensure that the same 1484 * exact sequence number is never sent out twice (as could otherwise 1485 * happen when a port is recycled in less than the system tick 1486 * interval.) 1487 * 1488 * net.inet.tcp.isn_reseed_interval controls the number of seconds 1489 * between seeding of isn_secret. This is normally set to zero, 1490 * as reseeding should not be necessary. 1491 * 1492 * Locking of the global variables isn_secret, isn_last_reseed, isn_offset, 1493 * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In 1494 * general, this means holding an exclusive (write) lock. 1495 */ 1496 1497#define ISN_BYTES_PER_SECOND 1048576 1498#define ISN_STATIC_INCREMENT 4096 1499#define ISN_RANDOM_INCREMENT (4096 - 1) 1500 1501static VNET_DEFINE(u_char, isn_secret[32]); 1502static VNET_DEFINE(int, isn_last_reseed); 1503static VNET_DEFINE(u_int32_t, isn_offset); 1504static VNET_DEFINE(u_int32_t, isn_offset_old); 1505 1506#define V_isn_secret VNET(isn_secret) 1507#define V_isn_last_reseed VNET(isn_last_reseed) 1508#define V_isn_offset VNET(isn_offset) 1509#define V_isn_offset_old VNET(isn_offset_old) 1510 1511tcp_seq 1512tcp_new_isn(struct tcpcb *tp) 1513{ 1514 MD5_CTX isn_ctx; 1515 u_int32_t md5_buffer[4]; 1516 tcp_seq new_isn; 1517 1518 INP_WLOCK_ASSERT(tp->t_inpcb); 1519 1520 ISN_LOCK(); 1521 /* Seed if this is the first use, reseed if requested. */ 1522 if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) && 1523 (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz) 1524 < (u_int)ticks))) { 1525 read_random(&V_isn_secret, sizeof(V_isn_secret)); 1526 V_isn_last_reseed = ticks; 1527 } 1528 1529 /* Compute the md5 hash and return the ISN. */ 1530 MD5Init(&isn_ctx); 1531 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short)); 1532 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short)); 1533#ifdef INET6 1534 if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) { 1535 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_faddr, 1536 sizeof(struct in6_addr)); 1537 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->in6p_laddr, 1538 sizeof(struct in6_addr)); 1539 } else 1540#endif 1541 { 1542 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_faddr, 1543 sizeof(struct in_addr)); 1544 MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_laddr, 1545 sizeof(struct in_addr)); 1546 } 1547 MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret)); 1548 MD5Final((u_char *) &md5_buffer, &isn_ctx); 1549 new_isn = (tcp_seq) md5_buffer[0]; 1550 V_isn_offset += ISN_STATIC_INCREMENT + 1551 (arc4random() & ISN_RANDOM_INCREMENT); 1552 new_isn += V_isn_offset; 1553 ISN_UNLOCK(); 1554 return (new_isn); 1555} 1556 1557/* 1558 * Increment the offset to the next ISN_BYTES_PER_SECOND / 100 boundary 1559 * to keep time flowing at a relatively constant rate. If the random 1560 * increments have already pushed us past the projected offset, do nothing. 1561 */ 1562static void 1563tcp_isn_tick(void *xtp) 1564{ 1565 VNET_ITERATOR_DECL(vnet_iter); 1566 u_int32_t projected_offset; 1567 1568 VNET_LIST_RLOCK_NOSLEEP(); 1569 ISN_LOCK(); 1570 VNET_FOREACH(vnet_iter) { 1571 CURVNET_SET(vnet_iter); /* XXX appease INVARIANTS */ 1572 projected_offset = 1573 V_isn_offset_old + ISN_BYTES_PER_SECOND / 100; 1574 1575 if (SEQ_GT(projected_offset, V_isn_offset)) 1576 V_isn_offset = projected_offset; 1577 1578 V_isn_offset_old = V_isn_offset; 1579 CURVNET_RESTORE(); 1580 } 1581 ISN_UNLOCK(); 1582 VNET_LIST_RUNLOCK_NOSLEEP(); 1583 callout_reset(&isn_callout, hz/100, tcp_isn_tick, NULL); 1584} 1585 1586/* 1587 * When a specific ICMP unreachable message is received and the 1588 * connection state is SYN-SENT, drop the connection. This behavior 1589 * is controlled by the icmp_may_rst sysctl. 1590 */ 1591struct inpcb * 1592tcp_drop_syn_sent(struct inpcb *inp, int errno) 1593{ 1594 struct tcpcb *tp; 1595 1596 INP_INFO_WLOCK_ASSERT(&V_tcbinfo); 1597 INP_WLOCK_ASSERT(inp); 1598 1599 if ((inp->inp_flags & INP_TIMEWAIT) || 1600 (inp->inp_flags & INP_DROPPED)) 1601 return (inp); 1602 1603 tp = intotcpcb(inp); 1604 if (tp->t_state != TCPS_SYN_SENT) 1605 return (inp); 1606 1607 tp = tcp_drop(tp, errno); 1608 if (tp != NULL) 1609 return (inp); 1610 else 1611 return (NULL); 1612} 1613 1614/* 1615 * When `need fragmentation' ICMP is received, update our idea of the MSS 1616 * based on the new value in the route. Also nudge TCP to send something, 1617 * since we know the packet we just sent was dropped. 1618 * This duplicates some code in the tcp_mss() function in tcp_input.c. 1619 */ 1620struct inpcb * 1621tcp_mtudisc(struct inpcb *inp, int errno) 1622{ 1623 struct tcpcb *tp; 1624 struct socket *so; 1625 1626 INP_WLOCK_ASSERT(inp); 1627 if ((inp->inp_flags & INP_TIMEWAIT) || 1628 (inp->inp_flags & INP_DROPPED)) 1629 return (inp); 1630 1631 tp = intotcpcb(inp); 1632 KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL")); 1633 1634 tcp_mss_update(tp, -1, NULL, NULL); 1635 1636 so = inp->inp_socket; 1637 SOCKBUF_LOCK(&so->so_snd); 1638 /* If the mss is larger than the socket buffer, decrease the mss. */ 1639 if (so->so_snd.sb_hiwat < tp->t_maxseg) 1640 tp->t_maxseg = so->so_snd.sb_hiwat; 1641 SOCKBUF_UNLOCK(&so->so_snd); 1642 1643 TCPSTAT_INC(tcps_mturesent); 1644 tp->t_rtttime = 0; 1645 tp->snd_nxt = tp->snd_una; 1646 tcp_free_sackholes(tp); 1647 tp->snd_recover = tp->snd_max; 1648 if (tp->t_flags & TF_SACK_PERMIT) 1649 EXIT_FASTRECOVERY(tp); 1650 tcp_output_send(tp); 1651 return (inp); 1652} 1653 1654/* 1655 * Look-up the routing entry to the peer of this inpcb. If no route 1656 * is found and it cannot be allocated, then return 0. This routine 1657 * is called by TCP routines that access the rmx structure and by 1658 * tcp_mss_update to get the peer/interface MTU. 1659 */ 1660u_long 1661tcp_maxmtu(struct in_conninfo *inc, int *flags) 1662{ 1663 struct route sro; 1664 struct sockaddr_in *dst; 1665 struct ifnet *ifp; 1666 u_long maxmtu = 0; 1667 1668 KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer")); 1669 1670 bzero(&sro, sizeof(sro)); 1671 if (inc->inc_faddr.s_addr != INADDR_ANY) { 1672 dst = (struct sockaddr_in *)&sro.ro_dst; 1673 dst->sin_family = AF_INET; 1674 dst->sin_len = sizeof(*dst); 1675 dst->sin_addr = inc->inc_faddr; 1676 in_rtalloc_ign(&sro, 0, inc->inc_fibnum); 1677 } 1678 if (sro.ro_rt != NULL) { 1679 ifp = sro.ro_rt->rt_ifp; 1680 if (sro.ro_rt->rt_rmx.rmx_mtu == 0) 1681 maxmtu = ifp->if_mtu; 1682 else 1683 maxmtu = min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu); 1684 1685 /* Report additional interface capabilities. */ 1686 if (flags != NULL) { 1687 if (ifp->if_capenable & IFCAP_TSO4 && 1688 ifp->if_hwassist & CSUM_TSO) 1689 *flags |= CSUM_TSO; 1690 } 1691 RTFREE(sro.ro_rt); 1692 } 1693 return (maxmtu); 1694} 1695 1696#ifdef INET6 1697u_long 1698tcp_maxmtu6(struct in_conninfo *inc, int *flags) 1699{ 1700 struct route_in6 sro6; 1701 struct ifnet *ifp; 1702 u_long maxmtu = 0; 1703 1704 KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer")); 1705 1706 bzero(&sro6, sizeof(sro6)); 1707 if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { 1708 sro6.ro_dst.sin6_family = AF_INET6; 1709 sro6.ro_dst.sin6_len = sizeof(struct sockaddr_in6); 1710 sro6.ro_dst.sin6_addr = inc->inc6_faddr; 1711 rtalloc_ign((struct route *)&sro6, 0); 1712 } 1713 if (sro6.ro_rt != NULL) { 1714 ifp = sro6.ro_rt->rt_ifp; 1715 if (sro6.ro_rt->rt_rmx.rmx_mtu == 0) 1716 maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp); 1717 else 1718 maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu, 1719 IN6_LINKMTU(sro6.ro_rt->rt_ifp)); 1720 1721 /* Report additional interface capabilities. */ 1722 if (flags != NULL) { 1723 if (ifp->if_capenable & IFCAP_TSO6 && 1724 ifp->if_hwassist & CSUM_TSO) 1725 *flags |= CSUM_TSO; 1726 } 1727 RTFREE(sro6.ro_rt); 1728 } 1729 1730 return (maxmtu); 1731} 1732#endif /* INET6 */ 1733 1734#ifdef IPSEC 1735/* compute ESP/AH header size for TCP, including outer IP header. */ 1736size_t 1737ipsec_hdrsiz_tcp(struct tcpcb *tp) 1738{ 1739 struct inpcb *inp; 1740 struct mbuf *m; 1741 size_t hdrsiz; 1742 struct ip *ip; 1743#ifdef INET6 1744 struct ip6_hdr *ip6; 1745#endif 1746 struct tcphdr *th; 1747 1748 if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL)) 1749 return (0); 1750 MGETHDR(m, M_DONTWAIT, MT_DATA); 1751 if (!m) 1752 return (0); 1753 1754#ifdef INET6 1755 if ((inp->inp_vflag & INP_IPV6) != 0) { 1756 ip6 = mtod(m, struct ip6_hdr *); 1757 th = (struct tcphdr *)(ip6 + 1); 1758 m->m_pkthdr.len = m->m_len = 1759 sizeof(struct ip6_hdr) + sizeof(struct tcphdr); 1760 tcpip_fillheaders(inp, ip6, th); 1761 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1762 } else 1763#endif /* INET6 */ 1764 { 1765 ip = mtod(m, struct ip *); 1766 th = (struct tcphdr *)(ip + 1); 1767 m->m_pkthdr.len = m->m_len = sizeof(struct tcpiphdr); 1768 tcpip_fillheaders(inp, ip, th); 1769 hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp); 1770 } 1771 1772 m_free(m); 1773 return (hdrsiz); 1774} 1775#endif /* IPSEC */ 1776 1777/* 1778 * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING 1779 * 1780 * This code attempts to calculate the bandwidth-delay product as a 1781 * means of determining the optimal window size to maximize bandwidth, 1782 * minimize RTT, and avoid the over-allocation of buffers on interfaces and 1783 * routers. This code also does a fairly good job keeping RTTs in check 1784 * across slow links like modems. We implement an algorithm which is very 1785 * similar (but not meant to be) TCP/Vegas. The code operates on the 1786 * transmitter side of a TCP connection and so only effects the transmit 1787 * side of the connection. 1788 * 1789 * BACKGROUND: TCP makes no provision for the management of buffer space 1790 * at the end points or at the intermediate routers and switches. A TCP 1791 * stream, whether using NewReno or not, will eventually buffer as 1792 * many packets as it is able and the only reason this typically works is 1793 * due to the fairly small default buffers made available for a connection 1794 * (typicaly 16K or 32K). As machines use larger windows and/or window 1795 * scaling it is now fairly easy for even a single TCP connection to blow-out 1796 * all available buffer space not only on the local interface, but on 1797 * intermediate routers and switches as well. NewReno makes a misguided 1798 * attempt to 'solve' this problem by waiting for an actual failure to occur, 1799 * then backing off, then steadily increasing the window again until another 1800 * failure occurs, ad-infinitum. This results in terrible oscillation that 1801 * is only made worse as network loads increase and the idea of intentionally 1802 * blowing out network buffers is, frankly, a terrible way to manage network 1803 * resources. 1804 * 1805 * It is far better to limit the transmit window prior to the failure 1806 * condition being achieved. There are two general ways to do this: First 1807 * you can 'scan' through different transmit window sizes and locate the 1808 * point where the RTT stops increasing, indicating that you have filled the 1809 * pipe, then scan backwards until you note that RTT stops decreasing, then 1810 * repeat ad-infinitum. This method works in principle but has severe 1811 * implementation issues due to RTT variances, timer granularity, and 1812 * instability in the algorithm which can lead to many false positives and 1813 * create oscillations as well as interact badly with other TCP streams 1814 * implementing the same algorithm. 1815 * 1816 * The second method is to limit the window to the bandwidth delay product 1817 * of the link. This is the method we implement. RTT variances and our 1818 * own manipulation of the congestion window, bwnd, can potentially 1819 * destabilize the algorithm. For this reason we have to stabilize the 1820 * elements used to calculate the window. We do this by using the minimum 1821 * observed RTT, the long term average of the observed bandwidth, and 1822 * by adding two segments worth of slop. It isn't perfect but it is able 1823 * to react to changing conditions and gives us a very stable basis on 1824 * which to extend the algorithm. 1825 */ 1826void 1827tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) 1828{ 1829 u_long bw; 1830 u_long bwnd; 1831 int save_ticks; 1832 1833 INP_WLOCK_ASSERT(tp->t_inpcb); 1834 1835 /* 1836 * If inflight_enable is disabled in the middle of a tcp connection, 1837 * make sure snd_bwnd is effectively disabled. 1838 */ 1839 if (V_tcp_inflight_enable == 0 || 1840 tp->t_rttlow < V_tcp_inflight_rttthresh) { 1841 tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; 1842 tp->snd_bandwidth = 0; 1843 return; 1844 } 1845 1846 /* 1847 * Figure out the bandwidth. Due to the tick granularity this 1848 * is a very rough number and it MUST be averaged over a fairly 1849 * long period of time. XXX we need to take into account a link 1850 * that is not using all available bandwidth, but for now our 1851 * slop will ramp us up if this case occurs and the bandwidth later 1852 * increases. 1853 * 1854 * Note: if ticks rollover 'bw' may wind up negative. We must 1855 * effectively reset t_bw_rtttime for this case. 1856 */ 1857 save_ticks = ticks; 1858 if ((u_int)(save_ticks - tp->t_bw_rtttime) < 1) 1859 return; 1860 1861 bw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / 1862 (save_ticks - tp->t_bw_rtttime); 1863 tp->t_bw_rtttime = save_ticks; 1864 tp->t_bw_rtseq = ack_seq; 1865 if (tp->t_bw_rtttime == 0 || (int)bw < 0) 1866 return; 1867 bw = ((int64_t)tp->snd_bandwidth * 15 + bw) >> 4; 1868 1869 tp->snd_bandwidth = bw; 1870 1871 /* 1872 * Calculate the semi-static bandwidth delay product, plus two maximal 1873 * segments. The additional slop puts us squarely in the sweet 1874 * spot and also handles the bandwidth run-up case and stabilization. 1875 * Without the slop we could be locking ourselves into a lower 1876 * bandwidth. 1877 * 1878 * Situations Handled: 1879 * (1) Prevents over-queueing of packets on LANs, especially on 1880 * high speed LANs, allowing larger TCP buffers to be 1881 * specified, and also does a good job preventing 1882 * over-queueing of packets over choke points like modems 1883 * (at least for the transmit side). 1884 * 1885 * (2) Is able to handle changing network loads (bandwidth 1886 * drops so bwnd drops, bandwidth increases so bwnd 1887 * increases). 1888 * 1889 * (3) Theoretically should stabilize in the face of multiple 1890 * connections implementing the same algorithm (this may need 1891 * a little work). 1892 * 1893 * (4) Stability value (defaults to 20 = 2 maximal packets) can 1894 * be adjusted with a sysctl but typically only needs to be 1895 * on very slow connections. A value no smaller then 5 1896 * should be used, but only reduce this default if you have 1897 * no other choice. 1898 */ 1899#define USERTT ((tp->t_srtt + tp->t_rttbest) / 2) 1900 bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + V_tcp_inflight_stab * tp->t_maxseg / 10; 1901#undef USERTT 1902 1903 if (tcp_inflight_debug > 0) { 1904 static int ltime; 1905 if ((u_int)(ticks - ltime) >= hz / tcp_inflight_debug) { 1906 ltime = ticks; 1907 printf("%p bw %ld rttbest %d srtt %d bwnd %ld\n", 1908 tp, 1909 bw, 1910 tp->t_rttbest, 1911 tp->t_srtt, 1912 bwnd 1913 ); 1914 } 1915 } 1916 if ((long)bwnd < V_tcp_inflight_min) 1917 bwnd = V_tcp_inflight_min; 1918 if (bwnd > V_tcp_inflight_max) 1919 bwnd = V_tcp_inflight_max; 1920 if ((long)bwnd < tp->t_maxseg * 2) 1921 bwnd = tp->t_maxseg * 2; 1922 tp->snd_bwnd = bwnd; 1923} 1924 1925#ifdef TCP_SIGNATURE 1926/* 1927 * Callback function invoked by m_apply() to digest TCP segment data 1928 * contained within an mbuf chain. 1929 */ 1930static int 1931tcp_signature_apply(void *fstate, void *data, u_int len) 1932{ 1933 1934 MD5Update(fstate, (u_char *)data, len); 1935 return (0); 1936} 1937 1938/* 1939 * Compute TCP-MD5 hash of a TCP segment. (RFC2385) 1940 * 1941 * Parameters: 1942 * m pointer to head of mbuf chain 1943 * _unused 1944 * len length of TCP segment data, excluding options 1945 * optlen length of TCP segment options 1946 * buf pointer to storage for computed MD5 digest 1947 * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND) 1948 * 1949 * We do this over ip, tcphdr, segment data, and the key in the SADB. 1950 * When called from tcp_input(), we can be sure that th_sum has been 1951 * zeroed out and verified already. 1952 * 1953 * Return 0 if successful, otherwise return -1. 1954 * 1955 * XXX The key is retrieved from the system's PF_KEY SADB, by keying a 1956 * search with the destination IP address, and a 'magic SPI' to be 1957 * determined by the application. This is hardcoded elsewhere to 1179 1958 * right now. Another branch of this code exists which uses the SPD to 1959 * specify per-application flows but it is unstable. 1960 */ 1961int 1962tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen, 1963 u_char *buf, u_int direction) 1964{ 1965 union sockaddr_union dst; 1966 struct ippseudo ippseudo; 1967 MD5_CTX ctx; 1968 int doff; 1969 struct ip *ip; 1970 struct ipovly *ipovly; 1971 struct secasvar *sav; 1972 struct tcphdr *th; 1973#ifdef INET6 1974 struct ip6_hdr *ip6; 1975 struct in6_addr in6; 1976 char ip6buf[INET6_ADDRSTRLEN]; 1977 uint32_t plen; 1978 uint16_t nhdr; 1979#endif 1980 u_short savecsum; 1981 1982 KASSERT(m != NULL, ("NULL mbuf chain")); 1983 KASSERT(buf != NULL, ("NULL signature pointer")); 1984 1985 /* Extract the destination from the IP header in the mbuf. */ 1986 bzero(&dst, sizeof(union sockaddr_union)); 1987 ip = mtod(m, struct ip *); 1988#ifdef INET6 1989 ip6 = NULL; /* Make the compiler happy. */ 1990#endif 1991 switch (ip->ip_v) { 1992 case IPVERSION: 1993 dst.sa.sa_len = sizeof(struct sockaddr_in); 1994 dst.sa.sa_family = AF_INET; 1995 dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ? 1996 ip->ip_src : ip->ip_dst; 1997 break; 1998#ifdef INET6 1999 case (IPV6_VERSION >> 4): 2000 ip6 = mtod(m, struct ip6_hdr *); 2001 dst.sa.sa_len = sizeof(struct sockaddr_in6); 2002 dst.sa.sa_family = AF_INET6; 2003 dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ? 2004 ip6->ip6_src : ip6->ip6_dst; 2005 break; 2006#endif 2007 default: 2008 return (EINVAL); 2009 /* NOTREACHED */ 2010 break; 2011 } 2012 2013 /* Look up an SADB entry which matches the address of the peer. */ 2014 sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); 2015 if (sav == NULL) { 2016 ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__, 2017 (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) : 2018#ifdef INET6 2019 (ip->ip_v == (IPV6_VERSION >> 4)) ? 2020 ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) : 2021#endif 2022 "(unsupported)")); 2023 return (EINVAL); 2024 } 2025 2026 MD5Init(&ctx); 2027 /* 2028 * Step 1: Update MD5 hash with IP(v6) pseudo-header. 2029 * 2030 * XXX The ippseudo header MUST be digested in network byte order, 2031 * or else we'll fail the regression test. Assume all fields we've 2032 * been doing arithmetic on have been in host byte order. 2033 * XXX One cannot depend on ipovly->ih_len here. When called from 2034 * tcp_output(), the underlying ip_len member has not yet been set. 2035 */ 2036 switch (ip->ip_v) { 2037 case IPVERSION: 2038 ipovly = (struct ipovly *)ip; 2039 ippseudo.ippseudo_src = ipovly->ih_src; 2040 ippseudo.ippseudo_dst = ipovly->ih_dst; 2041 ippseudo.ippseudo_pad = 0; 2042 ippseudo.ippseudo_p = IPPROTO_TCP; 2043 ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + 2044 optlen); 2045 MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); 2046 2047 th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); 2048 doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; 2049 break; 2050#ifdef INET6 2051 /* 2052 * RFC 2385, 2.0 Proposal 2053 * For IPv6, the pseudo-header is as described in RFC 2460, namely the 2054 * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- 2055 * extended next header value (to form 32 bits), and 32-bit segment 2056 * length. 2057 * Note: Upper-Layer Packet Length comes before Next Header. 2058 */ 2059 case (IPV6_VERSION >> 4): 2060 in6 = ip6->ip6_src; 2061 in6_clearscope(&in6); 2062 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2063 in6 = ip6->ip6_dst; 2064 in6_clearscope(&in6); 2065 MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); 2066 plen = htonl(len + sizeof(struct tcphdr) + optlen); 2067 MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); 2068 nhdr = 0; 2069 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2070 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2071 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2072 nhdr = IPPROTO_TCP; 2073 MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); 2074 2075 th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); 2076 doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; 2077 break; 2078#endif 2079 default: 2080 return (EINVAL); 2081 /* NOTREACHED */ 2082 break; 2083 } 2084 2085 2086 /* 2087 * Step 2: Update MD5 hash with TCP header, excluding options. 2088 * The TCP checksum must be set to zero. 2089 */ 2090 savecsum = th->th_sum; 2091 th->th_sum = 0; 2092 MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); 2093 th->th_sum = savecsum; 2094 2095 /* 2096 * Step 3: Update MD5 hash with TCP segment data. 2097 * Use m_apply() to avoid an early m_pullup(). 2098 */ 2099 if (len > 0) 2100 m_apply(m, doff, len, tcp_signature_apply, &ctx); 2101 2102 /* 2103 * Step 4: Update MD5 hash with shared secret. 2104 */ 2105 MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth)); 2106 MD5Final(buf, &ctx); 2107 2108 key_sa_recordxfer(sav, m); 2109 KEY_FREESAV(&sav); 2110 return (0); 2111} 2112#endif /* TCP_SIGNATURE */ 2113 2114static int 2115sysctl_drop(SYSCTL_HANDLER_ARGS) 2116{ 2117 /* addrs[0] is a foreign socket, addrs[1] is a local one. */ 2118 struct sockaddr_storage addrs[2]; 2119 struct inpcb *inp; 2120 struct tcpcb *tp; 2121 struct tcptw *tw; 2122 struct sockaddr_in *fin, *lin; 2123#ifdef INET6 2124 struct sockaddr_in6 *fin6, *lin6; 2125#endif 2126 int error; 2127 2128 inp = NULL; 2129 fin = lin = NULL; 2130#ifdef INET6 2131 fin6 = lin6 = NULL; 2132#endif 2133 error = 0; 2134 2135 if (req->oldptr != NULL || req->oldlen != 0) 2136 return (EINVAL); 2137 if (req->newptr == NULL) 2138 return (EPERM); 2139 if (req->newlen < sizeof(addrs)) 2140 return (ENOMEM); 2141 error = SYSCTL_IN(req, &addrs, sizeof(addrs)); 2142 if (error) 2143 return (error); 2144 2145 switch (addrs[0].ss_family) { 2146#ifdef INET6 2147 case AF_INET6: 2148 fin6 = (struct sockaddr_in6 *)&addrs[0]; 2149 lin6 = (struct sockaddr_in6 *)&addrs[1]; 2150 if (fin6->sin6_len != sizeof(struct sockaddr_in6) || 2151 lin6->sin6_len != sizeof(struct sockaddr_in6)) 2152 return (EINVAL); 2153 if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) { 2154 if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) 2155 return (EINVAL); 2156 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[0]); 2157 in6_sin6_2_sin_in_sock((struct sockaddr *)&addrs[1]); 2158 fin = (struct sockaddr_in *)&addrs[0]; 2159 lin = (struct sockaddr_in *)&addrs[1]; 2160 break; 2161 } 2162 error = sa6_embedscope(fin6, V_ip6_use_defzone); 2163 if (error) 2164 return (error); 2165 error = sa6_embedscope(lin6, V_ip6_use_defzone); 2166 if (error) 2167 return (error); 2168 break; 2169#endif 2170 case AF_INET: 2171 fin = (struct sockaddr_in *)&addrs[0]; 2172 lin = (struct sockaddr_in *)&addrs[1]; 2173 if (fin->sin_len != sizeof(struct sockaddr_in) || 2174 lin->sin_len != sizeof(struct sockaddr_in)) 2175 return (EINVAL); 2176 break; 2177 default: 2178 return (EINVAL); 2179 } 2180 INP_INFO_WLOCK(&V_tcbinfo); 2181 switch (addrs[0].ss_family) { 2182#ifdef INET6 2183 case AF_INET6: 2184 inp = in6_pcblookup_hash(&V_tcbinfo, &fin6->sin6_addr, 2185 fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port, 0, 2186 NULL); 2187 break; 2188#endif 2189 case AF_INET: 2190 inp = in_pcblookup_hash(&V_tcbinfo, fin->sin_addr, 2191 fin->sin_port, lin->sin_addr, lin->sin_port, 0, NULL); 2192 break; 2193 } 2194 if (inp != NULL) { 2195 INP_WLOCK(inp); 2196 if (inp->inp_flags & INP_TIMEWAIT) { 2197 /* 2198 * XXXRW: There currently exists a state where an 2199 * inpcb is present, but its timewait state has been 2200 * discarded. For now, don't allow dropping of this 2201 * type of inpcb. 2202 */ 2203 tw = intotw(inp); 2204 if (tw != NULL) 2205 tcp_twclose(tw, 0); 2206 else 2207 INP_WUNLOCK(inp); 2208 } else if (!(inp->inp_flags & INP_DROPPED) && 2209 !(inp->inp_socket->so_options & SO_ACCEPTCONN)) { 2210 tp = intotcpcb(inp); 2211 tp = tcp_drop(tp, ECONNABORTED); 2212 if (tp != NULL) 2213 INP_WUNLOCK(inp); 2214 } else 2215 INP_WUNLOCK(inp); 2216 } else 2217 error = ESRCH; 2218 INP_INFO_WUNLOCK(&V_tcbinfo); 2219 return (error); 2220} 2221 2222SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop, 2223 CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL, 2224 0, sysctl_drop, "", "Drop TCP connection"); 2225 2226/* 2227 * Generate a standardized TCP log line for use throughout the 2228 * tcp subsystem. Memory allocation is done with M_NOWAIT to 2229 * allow use in the interrupt context. 2230 * 2231 * NB: The caller MUST free(s, M_TCPLOG) the returned string. 2232 * NB: The function may return NULL if memory allocation failed. 2233 * 2234 * Due to header inclusion and ordering limitations the struct ip 2235 * and ip6_hdr pointers have to be passed as void pointers. 2236 */ 2237char * 2238tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr, 2239 const void *ip6hdr) 2240{ 2241 char *s, *sp; 2242 size_t size; 2243 struct ip *ip; 2244#ifdef INET6 2245 const struct ip6_hdr *ip6; 2246 2247 ip6 = (const struct ip6_hdr *)ip6hdr; 2248#endif /* INET6 */ 2249 ip = (struct ip *)ip4hdr; 2250 2251 /* 2252 * The log line looks like this: 2253 * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>" 2254 */ 2255 size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") + 2256 sizeof(PRINT_TH_FLAGS) + 1 + 2257#ifdef INET6 2258 2 * INET6_ADDRSTRLEN; 2259#else 2260 2 * INET_ADDRSTRLEN; 2261#endif /* INET6 */ 2262 2263 /* Is logging enabled? */ 2264 if (tcp_log_debug == 0 && tcp_log_in_vain == 0) 2265 return (NULL); 2266 2267 s = malloc(size, M_TCPLOG, M_ZERO|M_NOWAIT); 2268 if (s == NULL) 2269 return (NULL); 2270 2271 strcat(s, "TCP: ["); 2272 sp = s + strlen(s); 2273 2274 if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) { 2275 inet_ntoa_r(inc->inc_faddr, sp); 2276 sp = s + strlen(s); 2277 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2278 sp = s + strlen(s); 2279 inet_ntoa_r(inc->inc_laddr, sp); 2280 sp = s + strlen(s); 2281 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2282#ifdef INET6 2283 } else if (inc) { 2284 ip6_sprintf(sp, &inc->inc6_faddr); 2285 sp = s + strlen(s); 2286 sprintf(sp, "]:%i to [", ntohs(inc->inc_fport)); 2287 sp = s + strlen(s); 2288 ip6_sprintf(sp, &inc->inc6_laddr); 2289 sp = s + strlen(s); 2290 sprintf(sp, "]:%i", ntohs(inc->inc_lport)); 2291 } else if (ip6 && th) { 2292 ip6_sprintf(sp, &ip6->ip6_src); 2293 sp = s + strlen(s); 2294 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2295 sp = s + strlen(s); 2296 ip6_sprintf(sp, &ip6->ip6_dst); 2297 sp = s + strlen(s); 2298 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2299#endif /* INET6 */ 2300 } else if (ip && th) { 2301 inet_ntoa_r(ip->ip_src, sp); 2302 sp = s + strlen(s); 2303 sprintf(sp, "]:%i to [", ntohs(th->th_sport)); 2304 sp = s + strlen(s); 2305 inet_ntoa_r(ip->ip_dst, sp); 2306 sp = s + strlen(s); 2307 sprintf(sp, "]:%i", ntohs(th->th_dport)); 2308 } else { 2309 free(s, M_TCPLOG); 2310 return (NULL); 2311 } 2312 sp = s + strlen(s); 2313 if (th) 2314 sprintf(sp, " tcpflags 0x%b", th->th_flags, PRINT_TH_FLAGS); 2315 if (*(s + size - 1) != '\0') 2316 panic("%s: string too long", __func__); 2317 return (s); 2318}
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