/* * Copyright (c) 2003, 2004 Jeffrey M. Hsu. All rights reserved. * Copyright (c) 2003, 2004 The DragonFly Project. All rights reserved. * * This code is derived from software contributed to The DragonFly Project * by Jeffrey M. Hsu. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of The DragonFly Project nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific, prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * Copyright (c) 1982, 1986, 1988, 1990, 1993, 1995 * The Regents of the University of California. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)tcp_subr.c 8.2 (Berkeley) 5/24/95 * $FreeBSD: src/sys/netinet/tcp_subr.c,v 1.73.2.31 2003/01/24 05:11:34 sam Exp $ */ #include "opt_inet.h" #include "opt_inet6.h" #include "opt_tcpdebug.h" #include #include #include #include #include #include #include #include #ifdef INET6 #include #endif #include #include #include #include #include #include #include #include #include #include #include #include #define _IP_VHL #include #include #include #include #include #include #include #include #include #include #ifdef INET6 #include #endif #include #include #include #include #include #include #include #include #ifdef TCPDEBUG #include #endif #include #include #include #include #include #if !defined(KTR_TCP) #define KTR_TCP KTR_ALL #endif /* KTR_INFO_MASTER(tcp); KTR_INFO(KTR_TCP, tcp, rxmsg, 0, "tcp getmsg", 0); KTR_INFO(KTR_TCP, tcp, wait, 1, "tcp waitmsg", 0); KTR_INFO(KTR_TCP, tcp, delayed, 2, "tcp execute delayed ops", 0); #define logtcp(name) KTR_LOG(tcp_ ## name) */ #define TCP_IW_MAXSEGS_DFLT 4 #define TCP_IW_CAPSEGS_DFLT 4 struct tcp_reass_pcpu { int draining; struct netmsg_base drain_nmsg; } __cachealign; struct inpcbinfo tcbinfo[MAXCPU]; struct tcpcbackq tcpcbackq[MAXCPU]; struct tcp_reass_pcpu tcp_reassq[MAXCPU]; int tcp_mssdflt = TCP_MSS; SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, CTLFLAG_RW, &tcp_mssdflt, 0, "Default TCP Maximum Segment Size"); #ifdef INET6 int tcp_v6mssdflt = TCP6_MSS; SYSCTL_INT(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt, CTLFLAG_RW, &tcp_v6mssdflt, 0, "Default TCP Maximum Segment Size for IPv6"); #endif /* * Minimum MSS we accept and use. This prevents DoS attacks where * we are forced to a ridiculous low MSS like 20 and send hundreds * of packets instead of one. The effect scales with the available * bandwidth and quickly saturates the CPU and network interface * with packet generation and sending. Set to zero to disable MINMSS * checking. This setting prevents us from sending too small packets. */ int tcp_minmss = TCP_MINMSS; SYSCTL_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW, &tcp_minmss , 0, "Minmum TCP Maximum Segment Size"); #if 0 static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, CTLFLAG_RW, &tcp_rttdflt, 0, "Default maximum TCP Round Trip Time"); #endif int tcp_do_rfc1323 = 1; SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW, &tcp_do_rfc1323, 0, "Enable rfc1323 (high performance TCP) extensions"); static int tcp_tcbhashsize = 0; SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RD, &tcp_tcbhashsize, 0, "Size of TCP control block hashtable"); static int do_tcpdrain = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, do_tcpdrain, CTLFLAG_RW, &do_tcpdrain, 0, "Enable tcp_drain routine for extra help when low on mbufs"); static int icmp_may_rst = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW, &icmp_may_rst, 0, "Certain ICMP unreachable messages may abort connections in SYN_SENT"); /* * Recommend 20 (6 times in two minutes) * * Lower values may cause the sequence space to cycle too quickly and lose * its signed monotonically-increasing nature within the 2-minute TIMEDWAIT * window. */ static int tcp_isn_reseed_interval = 20; SYSCTL_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW, &tcp_isn_reseed_interval, 0, "Seconds between reseeding of ISN secret"); /* * TCP bandwidth limiting sysctls. The inflight limiter is now turned on * by default, but with generous values which should allow maximal * bandwidth. In particular, the slop defaults to 50 (5 packets). * * The reason for doing this is that the limiter is the only mechanism we * have which seems to do a really good job preventing receiver RX rings * on network interfaces from getting blown out. Even though GigE/10GigE * is supposed to flow control it looks like either it doesn't actually * do it or Open Source drivers do not properly enable it. * * People using the limiter to reduce bottlenecks on slower WAN connections * should set the slop to 20 (2 packets). */ static int tcp_inflight_enable = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_enable, CTLFLAG_RW, &tcp_inflight_enable, 0, "Enable automatic TCP inflight data limiting"); static int tcp_inflight_debug = 0; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_debug, CTLFLAG_RW, &tcp_inflight_debug, 0, "Debug TCP inflight calculations"); /* * NOTE: tcp_inflight_start is essentially the starting receive window * for a connection. If set too low then fetches over tcp * connections will take noticably longer to ramp-up over * high-latency connections. 6144 is too low for a default, * use something more reasonable. */ static int tcp_inflight_start = 33792; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_start, CTLFLAG_RW, &tcp_inflight_start, 0, "Start value for TCP inflight window"); static int tcp_inflight_min = 6144; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_min, CTLFLAG_RW, &tcp_inflight_min, 0, "Lower bound for TCP inflight window"); static int tcp_inflight_max = TCP_MAXWIN << TCP_MAX_WINSHIFT; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_max, CTLFLAG_RW, &tcp_inflight_max, 0, "Upper bound for TCP inflight window"); static int tcp_inflight_stab = 50; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_stab, CTLFLAG_RW, &tcp_inflight_stab, 0, "Fudge bw 1/10% (50=5%)"); static int tcp_inflight_adjrtt = 2; SYSCTL_INT(_net_inet_tcp, OID_AUTO, inflight_adjrtt, CTLFLAG_RW, &tcp_inflight_adjrtt, 0, "Slop for rtt 1/(hz*32)"); static int tcp_do_rfc3390 = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, rfc3390, CTLFLAG_RW, &tcp_do_rfc3390, 0, "Enable RFC 3390 (Increasing TCP's Initial Congestion Window)"); static u_long tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwmaxsegs, CTLFLAG_RW, &tcp_iw_maxsegs, 0, "TCP IW segments max"); static u_long tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; SYSCTL_ULONG(_net_inet_tcp, OID_AUTO, iwcapsegs, CTLFLAG_RW, &tcp_iw_capsegs, 0, "TCP IW segments"); int tcp_low_rtobase = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, low_rtobase, CTLFLAG_RW, &tcp_low_rtobase, 0, "Lowering the Initial RTO (RFC 6298)"); static int tcp_do_ncr = 1; SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr, CTLFLAG_RW, &tcp_do_ncr, 0, "Non-Congestion Robustness (RFC 4653)"); int tcp_ncr_linklocal = 0; SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_linklocal, CTLFLAG_RW, &tcp_ncr_linklocal, 0, "Enable Non-Congestion Robustness (RFC 4653) on link local network"); int tcp_ncr_rxtthresh_max = 16; SYSCTL_INT(_net_inet_tcp, OID_AUTO, ncr_rxtthresh_max, CTLFLAG_RW, &tcp_ncr_rxtthresh_max, 0, "Non-Congestion Robustness (RFC 4653), DupThresh upper limit"); static MALLOC_DEFINE(M_TCPTEMP, "tcptemp", "TCP Templates for Keepalives"); static struct malloc_pipe tcptemp_mpipe; static void tcp_willblock(void); static void tcp_notify (struct inpcb *, int); struct tcp_stats tcpstats_percpu[MAXCPU] __cachealign; struct tcp_state_count tcpstate_count[MAXCPU] __cachealign; static void tcp_drain_dispatch(netmsg_t nmsg); static int sysctl_tcpstats(SYSCTL_HANDLER_ARGS) { int cpu, error = 0; for (cpu = 0; cpu < netisr_ncpus; ++cpu) { if ((error = SYSCTL_OUT(req, &tcpstats_percpu[cpu], sizeof(struct tcp_stats)))) break; if ((error = SYSCTL_IN(req, &tcpstats_percpu[cpu], sizeof(struct tcp_stats)))) break; } return (error); } SYSCTL_PROC(_net_inet_tcp, TCPCTL_STATS, stats, (CTLTYPE_OPAQUE | CTLFLAG_RW), 0, 0, sysctl_tcpstats, "S,tcp_stats", "TCP statistics"); /* * Target size of TCP PCB hash tables. Must be a power of two. * * Note that this can be overridden by the kernel environment * variable net.inet.tcp.tcbhashsize */ #ifndef TCBHASHSIZE #define TCBHASHSIZE 512 #endif CTASSERT(powerof2(TCBHASHSIZE)); /* * This is the actual shape of what we allocate using the zone * allocator. Doing it this way allows us to protect both structures * using the same generation count, and also eliminates the overhead * of allocating tcpcbs separately. By hiding the structure here, * we avoid changing most of the rest of the code (although it needs * to be changed, eventually, for greater efficiency). */ #define ALIGNMENT 32 #define ALIGNM1 (ALIGNMENT - 1) struct inp_tp { union { struct inpcb inp; char align[(sizeof(struct inpcb) + ALIGNM1) & ~ALIGNM1]; } inp_tp_u; struct tcpcb tcb; struct tcp_callout inp_tp_rexmt; struct tcp_callout inp_tp_persist; struct tcp_callout inp_tp_keep; struct tcp_callout inp_tp_2msl; struct tcp_callout inp_tp_delack; struct netmsg_tcp_timer inp_tp_timermsg; struct netmsg_base inp_tp_sndmore; }; #undef ALIGNMENT #undef ALIGNM1 /* * Tcp initialization */ void tcp_init(void) { struct inpcbportinfo *portinfo; struct inpcbinfo *ticb; int hashsize = TCBHASHSIZE, portinfo_hsize; int cpu; /* * note: tcptemp is used for keepalives, and it is ok for an * allocation to fail so do not specify MPF_INT. */ mpipe_init(&tcptemp_mpipe, M_TCPTEMP, sizeof(struct tcptemp), 25, -1, 0, NULL, NULL, NULL); tcp_delacktime = TCPTV_DELACK; tcp_keepinit = TCPTV_KEEP_INIT; tcp_keepidle = TCPTV_KEEP_IDLE; tcp_keepintvl = TCPTV_KEEPINTVL; tcp_maxpersistidle = TCPTV_KEEP_IDLE; tcp_msl = TCPTV_MSL; tcp_rexmit_min = TCPTV_MIN; if (tcp_rexmit_min < 1) /* if kern.hz is too low */ tcp_rexmit_min = 1; tcp_rexmit_slop = TCPTV_CPU_VAR; TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize); if (!powerof2(hashsize)) { kprintf("WARNING: TCB hash size not a power of 2\n"); hashsize = TCBHASHSIZE; /* safe default */ } tcp_tcbhashsize = hashsize; portinfo_hsize = 65536 / netisr_ncpus; if (portinfo_hsize > hashsize) portinfo_hsize = hashsize; portinfo = kmalloc(sizeof(*portinfo) * netisr_ncpus, M_PCB, M_WAITOK | M_CACHEALIGN); for (cpu = 0; cpu < netisr_ncpus; cpu++) { ticb = &tcbinfo[cpu]; in_pcbinfo_init(ticb, cpu, FALSE); ticb->hashbase = hashinit(hashsize, M_PCB, &ticb->hashmask); in_pcbportinfo_init(&portinfo[cpu], portinfo_hsize, cpu); in_pcbportinfo_set(ticb, portinfo, netisr_ncpus); ticb->wildcardhashbase = hashinit(hashsize, M_PCB, &ticb->wildcardhashmask); ticb->localgrphashbase = hashinit(hashsize, M_PCB, &ticb->localgrphashmask); ticb->ipi_size = sizeof(struct inp_tp); TAILQ_INIT(&tcpcbackq[cpu].head); } tcp_reass_maxseg = nmbclusters / 16; TUNABLE_INT_FETCH("net.inet.tcp.reass.maxsegments", &tcp_reass_maxseg); #ifdef INET6 #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr)) #else #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr)) #endif if (max_protohdr < TCP_MINPROTOHDR) max_protohdr = TCP_MINPROTOHDR; if (max_linkhdr + TCP_MINPROTOHDR > MHLEN) panic("tcp_init"); #undef TCP_MINPROTOHDR /* * Initialize TCP statistics counters for each CPU. */ for (cpu = 0; cpu < netisr_ncpus; ++cpu) bzero(&tcpstats_percpu[cpu], sizeof(struct tcp_stats)); /* * Initialize netmsgs for TCP drain */ for (cpu = 0; cpu < netisr_ncpus; ++cpu) { netmsg_init(&tcp_reassq[cpu].drain_nmsg, NULL, &netisr_adone_rport, MSGF_PRIORITY, tcp_drain_dispatch); } syncache_init(); netisr_register_rollup(tcp_willblock, NETISR_ROLLUP_PRIO_TCP); } static void tcp_willblock(void) { struct tcpcb *tp; int cpu = mycpuid; while ((tp = TAILQ_FIRST(&tcpcbackq[cpu].head)) != NULL) { KKASSERT(tp->t_flags & TF_ONOUTPUTQ); tp->t_flags &= ~TF_ONOUTPUTQ; TAILQ_REMOVE(&tcpcbackq[cpu].head, tp, t_outputq); tcp_output(tp); } } /* * Fill in the IP and TCP headers for an outgoing packet, given the tcpcb. * tcp_template used to store this data in mbufs, but we now recopy it out * of the tcpcb each time to conserve mbufs. */ void tcp_fillheaders(struct tcpcb *tp, void *ip_ptr, void *tcp_ptr, boolean_t tso) { struct inpcb *inp = tp->t_inpcb; struct tcphdr *tcp_hdr = (struct tcphdr *)tcp_ptr; #ifdef INET6 if (INP_ISIPV6(inp)) { struct ip6_hdr *ip6; ip6 = (struct ip6_hdr *)ip_ptr; ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) | (inp->in6p_flowinfo & IPV6_FLOWINFO_MASK); ip6->ip6_vfc = (ip6->ip6_vfc & ~IPV6_VERSION_MASK) | (IPV6_VERSION & IPV6_VERSION_MASK); ip6->ip6_nxt = IPPROTO_TCP; ip6->ip6_plen = sizeof(struct tcphdr); ip6->ip6_src = inp->in6p_laddr; ip6->ip6_dst = inp->in6p_faddr; tcp_hdr->th_sum = 0; } else #endif { struct ip *ip = (struct ip *) ip_ptr; u_int plen; ip->ip_vhl = IP_VHL_BORING; ip->ip_tos = 0; ip->ip_len = 0; ip->ip_id = 0; ip->ip_off = 0; ip->ip_ttl = 0; ip->ip_sum = 0; ip->ip_p = IPPROTO_TCP; ip->ip_src = inp->inp_laddr; ip->ip_dst = inp->inp_faddr; if (tso) plen = htons(IPPROTO_TCP); else plen = htons(sizeof(struct tcphdr) + IPPROTO_TCP); tcp_hdr->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, plen); } tcp_hdr->th_sport = inp->inp_lport; tcp_hdr->th_dport = inp->inp_fport; tcp_hdr->th_seq = 0; tcp_hdr->th_ack = 0; tcp_hdr->th_x2 = 0; tcp_hdr->th_off = 5; tcp_hdr->th_flags = 0; tcp_hdr->th_win = 0; tcp_hdr->th_urp = 0; } /* * Create template to be used to send tcp packets on a connection. * Allocates an mbuf and fills in a skeletal tcp/ip header. The only * use for this function is in keepalives, which use tcp_respond. */ struct tcptemp * tcp_maketemplate(struct tcpcb *tp) { struct tcptemp *tmp; if ((tmp = mpipe_alloc_nowait(&tcptemp_mpipe)) == NULL) return (NULL); tcp_fillheaders(tp, &tmp->tt_ipgen, &tmp->tt_t, FALSE); return (tmp); } void tcp_freetemplate(struct tcptemp *tmp) { mpipe_free(&tcptemp_mpipe, tmp); } /* * Send a single message to the TCP at address specified by * the given TCP/IP header. If m == NULL, then we make a copy * of the tcpiphdr at ti and send directly to the addressed host. * This is used to force keep alive messages out using the TCP * template for a connection. If flags are given then we send * a message back to the TCP which originated the * segment ti, * and discard the mbuf containing it and any other attached mbufs. * * In any case the ack and sequence number of the transmitted * segment are as specified by the parameters. * * NOTE: If m != NULL, then ti must point to *inside* the mbuf. */ void tcp_respond(struct tcpcb *tp, void *ipgen, struct tcphdr *th, struct mbuf *m, tcp_seq ack, tcp_seq seq, int flags) { int tlen; long win = 0; struct route *ro = NULL; struct route sro; struct ip *ip = ipgen; struct tcphdr *nth; int ipflags = 0; struct route_in6 *ro6 = NULL; struct route_in6 sro6; struct ip6_hdr *ip6 = ipgen; struct inpcb *inp = NULL; boolean_t use_tmpro = TRUE; #ifdef INET6 boolean_t isipv6 = (IP_VHL_V(ip->ip_vhl) == 6); #else const boolean_t isipv6 = FALSE; #endif if (tp != NULL) { inp = tp->t_inpcb; if (!(flags & TH_RST)) { win = ssb_space(&inp->inp_socket->so_rcv); if (win < 0) win = 0; if (win > (long)TCP_MAXWIN << tp->rcv_scale) win = (long)TCP_MAXWIN << tp->rcv_scale; } /* * Don't use the route cache of a listen socket, * it is not MPSAFE; use temporary route cache. */ if (tp->t_state != TCPS_LISTEN) { if (isipv6) ro6 = &inp->in6p_route; else ro = &inp->inp_route; use_tmpro = FALSE; } } if (use_tmpro) { if (isipv6) { ro6 = &sro6; bzero(ro6, sizeof *ro6); } else { ro = &sro; bzero(ro, sizeof *ro); } } if (m == NULL) { m = m_gethdr(M_NOWAIT, MT_HEADER); if (m == NULL) return; tlen = 0; m->m_data += max_linkhdr; if (isipv6) { bcopy(ip6, mtod(m, caddr_t), sizeof(struct ip6_hdr)); ip6 = mtod(m, struct ip6_hdr *); nth = (struct tcphdr *)(ip6 + 1); } else { bcopy(ip, mtod(m, caddr_t), sizeof(struct ip)); ip = mtod(m, struct ip *); nth = (struct tcphdr *)(ip + 1); } bcopy(th, nth, sizeof(struct tcphdr)); flags = TH_ACK; } else { m_freem(m->m_next); m->m_next = NULL; m->m_data = (caddr_t)ipgen; /* m_len is set later */ tlen = 0; #define xchg(a, b, type) { type t; t = a; a = b; b = t; } if (isipv6) { xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr); nth = (struct tcphdr *)(ip6 + 1); } else { xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, n_long); nth = (struct tcphdr *)(ip + 1); } if (th != nth) { /* * this is usually a case when an extension header * exists between the IPv6 header and the * TCP header. */ nth->th_sport = th->th_sport; nth->th_dport = th->th_dport; } xchg(nth->th_dport, nth->th_sport, n_short); #undef xchg } if (isipv6) { ip6->ip6_flow = 0; ip6->ip6_vfc = IPV6_VERSION; ip6->ip6_nxt = IPPROTO_TCP; ip6->ip6_plen = htons((u_short)(sizeof(struct tcphdr) + tlen)); tlen += sizeof(struct ip6_hdr) + sizeof(struct tcphdr); } else { tlen += sizeof(struct tcpiphdr); ip->ip_len = htons(tlen); ip->ip_ttl = ip_defttl; } m->m_len = tlen; m->m_pkthdr.len = tlen; m->m_pkthdr.rcvif = NULL; nth->th_seq = htonl(seq); nth->th_ack = htonl(ack); nth->th_x2 = 0; nth->th_off = sizeof(struct tcphdr) >> 2; nth->th_flags = flags; if (tp != NULL) nth->th_win = htons((u_short) (win >> tp->rcv_scale)); else nth->th_win = htons((u_short)win); nth->th_urp = 0; if (isipv6) { nth->th_sum = 0; nth->th_sum = in6_cksum(m, IPPROTO_TCP, sizeof(struct ip6_hdr), tlen - sizeof(struct ip6_hdr)); ip6->ip6_hlim = in6_selecthlim(inp, (ro6 && ro6->ro_rt) ? ro6->ro_rt->rt_ifp : NULL); } else { nth->th_sum = in_pseudo(ip->ip_src.s_addr, ip->ip_dst.s_addr, htons((u_short)(tlen - sizeof(struct ip) + ip->ip_p))); m->m_pkthdr.csum_flags = CSUM_TCP; m->m_pkthdr.csum_data = offsetof(struct tcphdr, th_sum); m->m_pkthdr.csum_thlen = sizeof(struct tcphdr); } #ifdef TCPDEBUG if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG)) tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0); #endif if (isipv6) { ip6_output(m, NULL, ro6, ipflags, NULL, NULL, inp); if ((ro6 == &sro6) && (ro6->ro_rt != NULL)) { RTFREE(ro6->ro_rt); ro6->ro_rt = NULL; } } else { if (inp != NULL && (inp->inp_flags & INP_HASH)) m_sethash(m, inp->inp_hashval); ipflags |= IP_DEBUGROUTE; ip_output(m, NULL, ro, ipflags, NULL, inp); if ((ro == &sro) && (ro->ro_rt != NULL)) { RTFREE(ro->ro_rt); ro->ro_rt = NULL; } } } /* * Create a new TCP control block, making an * empty reassembly queue and hooking it to the argument * protocol control block. The `inp' parameter must have * come from the zone allocator set up in tcp_init(). */ void tcp_newtcpcb(struct inpcb *inp) { struct inp_tp *it; struct tcpcb *tp; #ifdef INET6 boolean_t isipv6 = INP_ISIPV6(inp); #else const boolean_t isipv6 = FALSE; #endif it = (struct inp_tp *)inp; tp = &it->tcb; bzero(tp, sizeof(struct tcpcb)); TAILQ_INIT(&tp->t_segq); tp->t_maxseg = tp->t_maxopd = isipv6 ? tcp_v6mssdflt : tcp_mssdflt; tp->t_rxtthresh = tcprexmtthresh; /* Set up our timeouts. */ tp->tt_rexmt = &it->inp_tp_rexmt; tp->tt_persist = &it->inp_tp_persist; tp->tt_keep = &it->inp_tp_keep; tp->tt_2msl = &it->inp_tp_2msl; tp->tt_delack = &it->inp_tp_delack; tcp_inittimers(tp); /* * Zero out timer message. We don't create it here, * since the current CPU may not be the owner of this * inpcb. */ tp->tt_msg = &it->inp_tp_timermsg; bzero(tp->tt_msg, sizeof(*tp->tt_msg)); tp->t_keepinit = tcp_keepinit; tp->t_keepidle = tcp_keepidle; tp->t_keepintvl = tcp_keepintvl; tp->t_keepcnt = tcp_keepcnt; tp->t_maxidle = tp->t_keepintvl * tp->t_keepcnt; if (tcp_do_ncr) tp->t_flags |= TF_NCR; if (tcp_do_rfc1323) tp->t_flags |= (TF_REQ_SCALE | TF_REQ_TSTMP); tp->t_inpcb = inp; /* XXX */ TCP_STATE_INIT(tp); /* * Init srtt to TCPTV_SRTTBASE (0), so we can tell that we have no * rtt estimate. Set rttvar so that srtt + 4 * rttvar gives * reasonable initial retransmit time. */ tp->t_srtt = TCPTV_SRTTBASE; tp->t_rttvar = ((TCPTV_RTOBASE - TCPTV_SRTTBASE) << TCP_RTTVAR_SHIFT) / 4; tp->t_rttmin = tcp_rexmit_min; tp->t_rxtcur = TCPTV_RTOBASE; tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; tp->snd_last = ticks; tp->t_rcvtime = ticks; /* * IPv4 TTL initialization is necessary for an IPv6 socket as well, * because the socket may be bound to an IPv6 wildcard address, * which may match an IPv4-mapped IPv6 address. */ inp->inp_ip_ttl = ip_defttl; inp->inp_ppcb = tp; tcp_sack_tcpcb_init(tp); tp->tt_sndmore = &it->inp_tp_sndmore; tcp_output_init(tp); } /* * Drop a TCP connection, reporting the specified error. * If connection is synchronized, then send a RST to peer. */ struct tcpcb * tcp_drop(struct tcpcb *tp, int error) { struct socket *so = tp->t_inpcb->inp_socket; if (TCPS_HAVERCVDSYN(tp->t_state)) { TCP_STATE_CHANGE(tp, TCPS_CLOSED); tcp_output(tp); tcpstat.tcps_drops++; } else tcpstat.tcps_conndrops++; if (error == ETIMEDOUT && tp->t_softerror) error = tp->t_softerror; so->so_error = error; return (tcp_close(tp)); } struct netmsg_listen_detach { struct netmsg_base base; struct tcpcb *nm_tp; struct tcpcb *nm_tp_inh; }; static void tcp_listen_detach_handler(netmsg_t msg) { struct netmsg_listen_detach *nmsg = (struct netmsg_listen_detach *)msg; struct tcpcb *tp = nmsg->nm_tp; int cpu = mycpuid, nextcpu; if (tp->t_flags & TF_LISTEN) { syncache_destroy(tp, nmsg->nm_tp_inh); tcp_pcbport_merge_oncpu(tp); } in_pcbremwildcardhash_oncpu(tp->t_inpcb, &tcbinfo[cpu]); nextcpu = cpu + 1; if (nextcpu < netisr_ncpus) lwkt_forwardmsg(netisr_cpuport(nextcpu), &nmsg->base.lmsg); else lwkt_replymsg(&nmsg->base.lmsg, 0); } /* * Close a TCP control block: * discard all space held by the tcp * discard internet protocol block * wake up any sleepers */ struct tcpcb * tcp_close(struct tcpcb *tp) { struct tseg_qent *q; struct inpcb *inp = tp->t_inpcb; struct inpcb *inp_inh = NULL; struct tcpcb *tp_inh = NULL; struct socket *so = inp->inp_socket; struct rtentry *rt; boolean_t dosavessthresh; #ifdef INET6 boolean_t isipv6 = INP_ISIPV6(inp); #else const boolean_t isipv6 = FALSE; #endif if (tp->t_flags & TF_LISTEN) { /* * Pending socket/syncache inheritance * * If this is a listen(2) socket, find another listen(2) * socket in the same local group, which could inherit * the syncache and sockets pending on the completion * and incompletion queues. * * NOTE: * Currently the inheritance could only happen on the * listen(2) sockets w/ SO_REUSEPORT set. */ ASSERT_NETISR0; inp_inh = in_pcblocalgroup_last(&tcbinfo[0], inp); if (inp_inh != NULL) tp_inh = intotcpcb(inp_inh); } /* * INP_WILDCARD indicates that listen(2) has been called on * this socket. This implies: * - A wildcard inp's hash is replicated for each protocol thread. * - Syncache for this inp grows independently in each protocol * thread. * - There is more than one cpu * * We have to chain a message to the rest of the protocol threads * to cleanup the wildcard hash and the syncache. The cleanup * in the current protocol thread is defered till the end of this * function (syncache_destroy and in_pcbdetach). * * NOTE: * After cleanup the inp's hash and syncache entries, this inp will * no longer be available to the rest of the protocol threads, so we * are safe to whack the inp in the following code. */ if ((inp->inp_flags & INP_WILDCARD) && netisr_ncpus > 1) { struct netmsg_listen_detach nmsg; KKASSERT(so->so_port == netisr_cpuport(0)); ASSERT_NETISR0; KKASSERT(inp->inp_pcbinfo == &tcbinfo[0]); netmsg_init(&nmsg.base, NULL, &curthread->td_msgport, MSGF_PRIORITY, tcp_listen_detach_handler); nmsg.nm_tp = tp; nmsg.nm_tp_inh = tp_inh; lwkt_domsg(netisr_cpuport(1), &nmsg.base.lmsg, 0); } TCP_STATE_TERM(tp); /* * Make sure that all of our timers are stopped before we * delete the PCB. For listen TCP socket (tp->tt_msg == NULL), * timers are never used. If timer message is never created * (tp->tt_msg->tt_tcb == NULL), timers are never used too. */ if (tp->tt_msg != NULL && tp->tt_msg->tt_tcb != NULL) { tcp_callout_terminate(tp, tp->tt_rexmt); tcp_callout_terminate(tp, tp->tt_persist); tcp_callout_terminate(tp, tp->tt_keep); tcp_callout_terminate(tp, tp->tt_2msl); tcp_callout_terminate(tp, tp->tt_delack); } if (tp->t_flags & TF_ONOUTPUTQ) { KKASSERT(tp->tt_cpu == mycpu->gd_cpuid); TAILQ_REMOVE(&tcpcbackq[tp->tt_cpu].head, tp, t_outputq); tp->t_flags &= ~TF_ONOUTPUTQ; } /* * If we got enough samples through the srtt filter, * save the rtt and rttvar in the routing entry. * 'Enough' is arbitrarily defined as the 16 samples. * 16 samples is enough for the srtt filter to converge * to within 5% of the correct value; fewer samples and * we could save a very bogus rtt. * * Don't update the default route's characteristics and don't * update anything that the user "locked". */ if (tp->t_rttupdated >= 16) { u_long i = 0; if (isipv6) { struct sockaddr_in6 *sin6; if ((rt = inp->in6p_route.ro_rt) == NULL) goto no_valid_rt; sin6 = (struct sockaddr_in6 *)rt_key(rt); if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr)) goto no_valid_rt; } else if ((rt = inp->inp_route.ro_rt) == NULL || ((struct sockaddr_in *)rt_key(rt))-> sin_addr.s_addr == INADDR_ANY) goto no_valid_rt; if (!(rt->rt_rmx.rmx_locks & RTV_RTT)) { i = tp->t_srtt * (RTM_RTTUNIT / (hz * TCP_RTT_SCALE)); if (rt->rt_rmx.rmx_rtt && i) /* * filter this update to half the old & half * the new values, converting scale. * See route.h and tcp_var.h for a * description of the scaling constants. */ rt->rt_rmx.rmx_rtt = (rt->rt_rmx.rmx_rtt + i) / 2; else rt->rt_rmx.rmx_rtt = i; tcpstat.tcps_cachedrtt++; } if (!(rt->rt_rmx.rmx_locks & RTV_RTTVAR)) { i = tp->t_rttvar * (RTM_RTTUNIT / (hz * TCP_RTTVAR_SCALE)); if (rt->rt_rmx.rmx_rttvar && i) rt->rt_rmx.rmx_rttvar = (rt->rt_rmx.rmx_rttvar + i) / 2; else rt->rt_rmx.rmx_rttvar = i; tcpstat.tcps_cachedrttvar++; } /* * The old comment here said: * update the pipelimit (ssthresh) if it has been updated * already or if a pipesize was specified & the threshhold * got below half the pipesize. I.e., wait for bad news * before we start updating, then update on both good * and bad news. * * But we want to save the ssthresh even if no pipesize is * specified explicitly in the route, because such * connections still have an implicit pipesize specified * by the global tcp_sendspace. In the absence of a reliable * way to calculate the pipesize, it will have to do. */ i = tp->snd_ssthresh; if (rt->rt_rmx.rmx_sendpipe != 0) dosavessthresh = (i < rt->rt_rmx.rmx_sendpipe/2); else dosavessthresh = (i < so->so_snd.ssb_hiwat/2); if (dosavessthresh || (!(rt->rt_rmx.rmx_locks & RTV_SSTHRESH) && (i != 0) && (rt->rt_rmx.rmx_ssthresh != 0))) { /* * convert the limit from user data bytes to * packets then to packet data bytes. */ i = (i + tp->t_maxseg / 2) / tp->t_maxseg; if (i < 2) i = 2; i *= tp->t_maxseg + (isipv6 ? sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : sizeof(struct tcpiphdr)); if (rt->rt_rmx.rmx_ssthresh) rt->rt_rmx.rmx_ssthresh = (rt->rt_rmx.rmx_ssthresh + i) / 2; else rt->rt_rmx.rmx_ssthresh = i; tcpstat.tcps_cachedssthresh++; } } no_valid_rt: /* free the reassembly queue, if any */ while((q = TAILQ_FIRST(&tp->t_segq)) != NULL) { TAILQ_REMOVE(&tp->t_segq, q, tqe_q); m_freem(q->tqe_m); kfree(q, M_TSEGQ); atomic_add_int(&tcp_reass_qsize, -1); } /* throw away SACK blocks in scoreboard*/ if (TCP_DO_SACK(tp)) tcp_sack_destroy(&tp->scb); inp->inp_ppcb = NULL; soisdisconnected(so); /* note: pcb detached later on */ tcp_destroy_timermsg(tp); tcp_output_cancel(tp); if (tp->t_flags & TF_LISTEN) { syncache_destroy(tp, tp_inh); tcp_pcbport_merge_oncpu(tp); tcp_pcbport_destroy(tp); if (inp_inh != NULL && inp_inh->inp_socket != NULL) { /* * Pending sockets inheritance only needs * to be done once in the current thread, * i.e. netisr0. */ soinherit(so, inp_inh->inp_socket); } } KASSERT(tp->t_pcbport == NULL, ("tcpcb port cache is not destroyed")); so_async_rcvd_drop(so); /* Drop the reference for the asynchronized pru_rcvd */ sofree(so); /* * NOTE: * - Remove self from listen tcpcb per-cpu port cache _before_ * pcbdetach. * - pcbdetach removes any wildcard hash entry on the current CPU. */ tcp_pcbport_remove(inp); #ifdef INET6 if (isipv6) in6_pcbdetach(inp); else #endif in_pcbdetach(inp); tcpstat.tcps_closed++; return (NULL); } /* * Walk the tcpbs, if existing, and flush the reassembly queue, * if there is one... */ static void tcp_drain_oncpu(struct inpcbinfo *pcbinfo) { struct inpcbhead *head = &pcbinfo->pcblisthead; struct inpcb *inpb; /* * Since we run in netisr, it is MP safe, even if * we block during the inpcb list iteration, i.e. * we don't need to use inpcb marker here. */ ASSERT_NETISR_NCPUS(pcbinfo->cpu); LIST_FOREACH(inpb, head, inp_list) { struct tcpcb *tcpb; struct tseg_qent *te; if (inpb->inp_flags & INP_PLACEMARKER) continue; tcpb = intotcpcb(inpb); KASSERT(tcpb != NULL, ("tcp_drain_oncpu: tcpb is NULL")); if ((te = TAILQ_FIRST(&tcpb->t_segq)) != NULL) { TAILQ_REMOVE(&tcpb->t_segq, te, tqe_q); if (te->tqe_th->th_flags & TH_FIN) tcpb->t_flags &= ~TF_QUEDFIN; m_freem(te->tqe_m); kfree(te, M_TSEGQ); atomic_add_int(&tcp_reass_qsize, -1); /* retry */ } } } static void tcp_drain_dispatch(netmsg_t nmsg) { crit_enter(); lwkt_replymsg(&nmsg->lmsg, 0); /* reply ASAP */ crit_exit(); tcp_drain_oncpu(&tcbinfo[mycpuid]); tcp_reassq[mycpuid].draining = 0; } static void tcp_drain_ipi(void *arg __unused) { int cpu = mycpuid; struct lwkt_msg *msg = &tcp_reassq[cpu].drain_nmsg.lmsg; crit_enter(); if (msg->ms_flags & MSGF_DONE) lwkt_sendmsg_oncpu(netisr_cpuport(cpu), msg); crit_exit(); } void tcp_drain(void) { cpumask_t mask; int cpu; if (!do_tcpdrain) return; if (tcp_reass_qsize == 0) return; CPUMASK_ASSBMASK(mask, netisr_ncpus); CPUMASK_ANDMASK(mask, smp_active_mask); cpu = mycpuid; if (IN_NETISR_NCPUS(cpu)) { tcp_drain_oncpu(&tcbinfo[cpu]); CPUMASK_NANDBIT(mask, cpu); } if (tcp_reass_qsize < netisr_ncpus) { /* Does not worth the trouble. */ return; } for (cpu = 0; cpu < netisr_ncpus; ++cpu) { if (!CPUMASK_TESTBIT(mask, cpu)) continue; if (tcp_reassq[cpu].draining) { /* Draining; skip this cpu. */ CPUMASK_NANDBIT(mask, cpu); continue; } tcp_reassq[cpu].draining = 1; } if (CPUMASK_TESTNZERO(mask)) lwkt_send_ipiq_mask(mask, tcp_drain_ipi, NULL); } /* * Notify a tcp user of an asynchronous error; * store error as soft error, but wake up user * (for now, won't do anything until can select for soft error). * * Do not wake up user since there currently is no mechanism for * reporting soft errors (yet - a kqueue filter may be added). */ static void tcp_notify(struct inpcb *inp, int error) { struct tcpcb *tp = intotcpcb(inp); /* * Ignore some errors if we are hooked up. * If connection hasn't completed, has retransmitted several times, * and receives a second error, give up now. This is better * than waiting a long time to establish a connection that * can never complete. */ if (tp->t_state == TCPS_ESTABLISHED && (error == EHOSTUNREACH || error == ENETUNREACH || error == EHOSTDOWN)) { return; } else if (tp->t_state < TCPS_ESTABLISHED && tp->t_rxtshift > 3 && tp->t_softerror) tcp_drop(tp, error); else tp->t_softerror = error; #if 0 wakeup(&so->so_timeo); sorwakeup(so); sowwakeup(so); #endif } static int tcp_pcblist(SYSCTL_HANDLER_ARGS) { int error, i, n; struct inpcb *marker; struct inpcb *inp; int origcpu, ccpu; error = 0; n = 0; /* * The process of preparing the TCB list is too time-consuming and * resource-intensive to repeat twice on every request. */ if (req->oldptr == NULL) { for (ccpu = 0; ccpu < netisr_ncpus; ++ccpu) n += tcbinfo[ccpu].ipi_count; req->oldidx = (n + n/8 + 10) * sizeof(struct xtcpcb); return (0); } if (req->newptr != NULL) return (EPERM); marker = kmalloc(sizeof(struct inpcb), M_TEMP, M_WAITOK|M_ZERO); marker->inp_flags |= INP_PLACEMARKER; /* * OK, now we're committed to doing something. Run the inpcb list * for each cpu in the system and construct the output. Use a * list placemarker to deal with list changes occuring during * copyout blockages (but otherwise depend on being on the correct * cpu to avoid races). */ origcpu = mycpu->gd_cpuid; for (ccpu = 0; ccpu < netisr_ncpus && error == 0; ++ccpu) { caddr_t inp_ppcb; struct xtcpcb xt; lwkt_migratecpu(ccpu); n = tcbinfo[ccpu].ipi_count; LIST_INSERT_HEAD(&tcbinfo[ccpu].pcblisthead, marker, inp_list); i = 0; while ((inp = LIST_NEXT(marker, inp_list)) != NULL && i < n) { /* * process a snapshot of pcbs, ignoring placemarkers * and using our own to allow SYSCTL_OUT to block. */ LIST_REMOVE(marker, inp_list); LIST_INSERT_AFTER(inp, marker, inp_list); if (inp->inp_flags & INP_PLACEMARKER) continue; if (prison_xinpcb(req->td, inp)) continue; xt.xt_len = sizeof xt; bcopy(inp, &xt.xt_inp, sizeof *inp); inp_ppcb = inp->inp_ppcb; if (inp_ppcb != NULL) bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp); else bzero(&xt.xt_tp, sizeof xt.xt_tp); if (inp->inp_socket) sotoxsocket(inp->inp_socket, &xt.xt_socket); if ((error = SYSCTL_OUT(req, &xt, sizeof xt)) != 0) break; ++i; } LIST_REMOVE(marker, inp_list); if (error == 0 && i < n) { bzero(&xt, sizeof xt); xt.xt_len = sizeof xt; while (i < n) { error = SYSCTL_OUT(req, &xt, sizeof xt); if (error) break; ++i; } } } /* * Make sure we are on the same cpu we were on originally, since * higher level callers expect this. Also don't pollute caches with * migrated userland data by (eventually) returning to userland * on a different cpu. */ lwkt_migratecpu(origcpu); kfree(marker, M_TEMP); return (error); } SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0, tcp_pcblist, "S,xtcpcb", "List of active TCP connections"); static int tcp_getcred(SYSCTL_HANDLER_ARGS) { struct sockaddr_in addrs[2]; struct ucred cred0, *cred = NULL; struct inpcb *inp; int cpu, origcpu, error; error = caps_priv_check_td(req->td, SYSCAP_RESTRICTEDROOT); if (error != 0) return (error); error = SYSCTL_IN(req, addrs, sizeof addrs); if (error != 0) return (error); origcpu = mycpuid; cpu = tcp_addrcpu(addrs[1].sin_addr.s_addr, addrs[1].sin_port, addrs[0].sin_addr.s_addr, addrs[0].sin_port); lwkt_migratecpu(cpu); inp = in_pcblookup_hash(&tcbinfo[cpu], addrs[1].sin_addr, addrs[1].sin_port, addrs[0].sin_addr, addrs[0].sin_port, 0, NULL); if (inp == NULL || inp->inp_socket == NULL) { error = ENOENT; } else if (inp->inp_socket->so_cred != NULL) { cred0 = *(inp->inp_socket->so_cred); cred = &cred0; } lwkt_migratecpu(origcpu); if (error) return (error); return SYSCTL_OUT(req, cred, sizeof(struct ucred)); } SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 0, 0, tcp_getcred, "S,ucred", "Get the ucred of a TCP connection"); #ifdef INET6 static int tcp6_getcred(SYSCTL_HANDLER_ARGS) { struct sockaddr_in6 addrs[2]; struct inpcb *inp; int error; error = caps_priv_check_td(req->td, SYSCAP_RESTRICTEDROOT); if (error != 0) return (error); error = SYSCTL_IN(req, addrs, sizeof addrs); if (error != 0) return (error); crit_enter(); inp = in6_pcblookup_hash(&tcbinfo[0], &addrs[1].sin6_addr, addrs[1].sin6_port, &addrs[0].sin6_addr, addrs[0].sin6_port, 0, NULL); if (inp == NULL || inp->inp_socket == NULL) { error = ENOENT; goto out; } error = SYSCTL_OUT(req, inp->inp_socket->so_cred, sizeof(struct ucred)); out: crit_exit(); return (error); } SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred, (CTLTYPE_OPAQUE | CTLFLAG_RW), 0, 0, tcp6_getcred, "S,ucred", "Get the ucred of a TCP6 connection"); #endif struct netmsg_tcp_notify { struct netmsg_base base; inp_notify_t nm_notify; struct in_addr nm_faddr; int nm_arg; }; static void tcp_notifyall_oncpu(netmsg_t msg) { struct netmsg_tcp_notify *nm = (struct netmsg_tcp_notify *)msg; int nextcpu; ASSERT_NETISR_NCPUS(mycpuid); in_pcbnotifyall(&tcbinfo[mycpuid], nm->nm_faddr, nm->nm_arg, nm->nm_notify); nextcpu = mycpuid + 1; if (nextcpu < netisr_ncpus) lwkt_forwardmsg(netisr_cpuport(nextcpu), &nm->base.lmsg); else lwkt_replymsg(&nm->base.lmsg, 0); } inp_notify_t tcp_get_inpnotify(int cmd, const struct sockaddr *sa, int *arg, struct ip **ip0, int *cpuid) { struct ip *ip = *ip0; struct in_addr faddr; inp_notify_t notify = tcp_notify; faddr = ((const struct sockaddr_in *)sa)->sin_addr; if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY) return NULL; *arg = inetctlerrmap[cmd]; if (cmd == PRC_QUENCH) { notify = tcp_quench; } else if (icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB || cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip != NULL) { notify = tcp_drop_syn_sent; } else if (cmd == PRC_MSGSIZE) { const struct icmp *icmp = (const struct icmp *) ((caddr_t)ip - offsetof(struct icmp, icmp_ip)); *arg = ntohs(icmp->icmp_nextmtu); notify = tcp_mtudisc; } else if (PRC_IS_REDIRECT(cmd)) { ip = NULL; notify = in_rtchange; } else if (cmd == PRC_HOSTDEAD) { ip = NULL; } else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0) { return NULL; } if (cpuid != NULL) { if (ip == NULL) { /* Go through all effective netisr CPUs. */ *cpuid = netisr_ncpus; } else { const struct tcphdr *th; th = (const struct tcphdr *) ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); *cpuid = tcp_addrcpu(faddr.s_addr, th->th_dport, ip->ip_src.s_addr, th->th_sport); } } *ip0 = ip; return notify; } void tcp_ctlinput(netmsg_t msg) { int cmd = msg->ctlinput.nm_cmd; struct sockaddr *sa = msg->ctlinput.nm_arg; struct ip *ip = msg->ctlinput.nm_extra; struct in_addr faddr; inp_notify_t notify; int arg, cpuid; ASSERT_NETISR_NCPUS(mycpuid); notify = tcp_get_inpnotify(cmd, sa, &arg, &ip, &cpuid); if (notify == NULL) goto done; faddr = ((struct sockaddr_in *)sa)->sin_addr; if (ip != NULL) { const struct tcphdr *th; struct inpcb *inp; if (cpuid != mycpuid) goto done; th = (const struct tcphdr *) ((caddr_t)ip + (IP_VHL_HL(ip->ip_vhl) << 2)); inp = in_pcblookup_hash(&tcbinfo[mycpuid], faddr, th->th_dport, ip->ip_src, th->th_sport, 0, NULL); if (inp != NULL && inp->inp_socket != NULL) { tcp_seq icmpseq = htonl(th->th_seq); struct tcpcb *tp = intotcpcb(inp); if (SEQ_GEQ(icmpseq, tp->snd_una) && SEQ_LT(icmpseq, tp->snd_max)) notify(inp, arg); } else { struct in_conninfo inc; inc.inc_fport = th->th_dport; inc.inc_lport = th->th_sport; inc.inc_faddr = faddr; inc.inc_laddr = ip->ip_src; #ifdef INET6 inc.inc_isipv6 = 0; #endif syncache_unreach(&inc, th); } } else if (msg->ctlinput.nm_direct) { if (cpuid != netisr_ncpus && cpuid != mycpuid) goto done; in_pcbnotifyall(&tcbinfo[mycpuid], faddr, arg, notify); } else { struct netmsg_tcp_notify *nm; ASSERT_NETISR0; nm = kmalloc(sizeof(*nm), M_LWKTMSG, M_INTWAIT); netmsg_init(&nm->base, NULL, &netisr_afree_rport, 0, tcp_notifyall_oncpu); nm->nm_faddr = faddr; nm->nm_arg = arg; nm->nm_notify = notify; lwkt_sendmsg(netisr_cpuport(0), &nm->base.lmsg); } done: lwkt_replymsg(&msg->lmsg, 0); } #ifdef INET6 void tcp6_ctlinput(netmsg_t msg) { int cmd = msg->ctlinput.nm_cmd; struct sockaddr *sa = msg->ctlinput.nm_arg; void *d = msg->ctlinput.nm_extra; struct tcphdr th; inp_notify_t notify = tcp_notify; struct ip6_hdr *ip6; struct mbuf *m; struct ip6ctlparam *ip6cp = NULL; const struct sockaddr_in6 *sa6_src = NULL; int off; struct tcp_portonly { u_int16_t th_sport; u_int16_t th_dport; } *thp; int arg; if (sa->sa_family != AF_INET6 || sa->sa_len != sizeof(struct sockaddr_in6)) { goto out; } arg = 0; if (cmd == PRC_QUENCH) notify = tcp_quench; else if (cmd == PRC_MSGSIZE) { /* * The MTU can be passed via an icmp6 packet or directly * via ip6c_cmdarg. */ struct ip6ctlparam *ip6cp = d; if (ip6cp->ip6c_icmp6) { struct icmp6_hdr *icmp6 = ip6cp->ip6c_icmp6; arg = ntohl(icmp6->icmp6_mtu); } else if (ip6cp->ip6c_cmdarg) { arg = *(uint32_t *)ip6cp->ip6c_cmdarg; } else { goto out; } notify = tcp_mtudisc; } else if (!PRC_IS_REDIRECT(cmd) && ((unsigned)cmd > PRC_NCMDS || inet6ctlerrmap[cmd] == 0)) { goto out; } /* * If the parameter is from icmp6, decode it. Note that in the * mtu shortcut case, the rest of the ip6ctlparam content is * 0 or NULL. */ if (d != NULL) { ip6cp = (struct ip6ctlparam *)d; m = ip6cp->ip6c_m; ip6 = ip6cp->ip6c_ip6; off = ip6cp->ip6c_off; sa6_src = ip6cp->ip6c_src; } else { m = NULL; ip6 = NULL; off = 0; /* fool gcc */ sa6_src = &sa6_any; } if (ip6 != NULL) { struct in_conninfo inc; /* * XXX: We assume that when IPV6 is non NULL, * M and OFF are valid. */ /* check if we can safely examine src and dst ports */ if (m->m_pkthdr.len < off + sizeof *thp) goto out; bzero(&th, sizeof th); m_copydata(m, off, sizeof *thp, &th); in6_pcbnotify(&tcbinfo[0], sa, th.th_dport, (struct sockaddr *)ip6cp->ip6c_src, th.th_sport, cmd, arg, notify); inc.inc_fport = th.th_dport; inc.inc_lport = th.th_sport; inc.inc6_faddr = ((struct sockaddr_in6 *)sa)->sin6_addr; inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr; inc.inc_isipv6 = 1; syncache_unreach(&inc, &th); } else { in6_pcbnotify(&tcbinfo[0], sa, 0, (const struct sockaddr *)sa6_src, 0, cmd, arg, notify); } out: lwkt_replymsg(&msg->ctlinput.base.lmsg, 0); } #endif /* * Following is where TCP initial sequence number generation occurs. * * There are two places where we must use initial sequence numbers: * 1. In SYN-ACK packets. * 2. In SYN packets. * * All ISNs for SYN-ACK packets are generated by the syncache. See * tcp_syncache.c for details. * * The ISNs in SYN packets must be monotonic; TIME_WAIT recycling * depends on this property. In addition, these ISNs should be * unguessable so as to prevent connection hijacking. To satisfy * the requirements of this situation, the algorithm outlined in * RFC 1948 is used to generate sequence numbers. * * Implementation details: * * net.inet.tcp.isn_reseed_interval controls the number of seconds * between the seeding of isn_secret. On every reseed we jump the * ISN by a lot. */ struct tcp_isn { u_char secret[16]; MD5_CTX ctx; int last_reseed; int last_offset; } __cachealign; struct tcp_isn tcp_isn_ary[MAXCPU]; tcp_seq tcp_new_isn(struct tcpcb *tp) { struct tcp_isn *isn; tcp_seq new_isn; tcp_seq digest[16 / sizeof(tcp_seq)]; int n; isn = &tcp_isn_ary[mycpuid]; /* * Reseed every 20 seconds. 6 reseeds per 2-minute interval in * order to retain our monotonic offset. * * The initial seed randomizes last_offset with all 32 bits. * * Note that the md5 digest is masked with 0x0FFFFFFF, so we must * add 1/16 of our full range (1/8 of our signed range) to ensure * monotonic operation. */ if (isn->last_reseed == 0 || (u_int)(ticks - isn->last_reseed) > tcp_isn_reseed_interval * hz) { if (isn->last_reseed == 0) { read_random(&isn->last_offset, sizeof(isn->last_offset), 1); } read_random(&isn->secret, sizeof(isn->secret), 1); isn->last_reseed = ticks; isn->last_offset += 0x10000000; } /* * Compute the md5 hash, giving us a deterministic result for the * port/address pair for any given secret. */ MD5Init(&isn->ctx); MD5Update(&isn->ctx, isn->secret, sizeof(isn->secret)); MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_fport, 2); MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_lport, 2); #ifdef INET6 if (INP_ISIPV6(tp->t_inpcb)) { MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->in6p_faddr, sizeof(struct in6_addr)); MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->in6p_laddr, sizeof(struct in6_addr)); } else #endif { MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_faddr, sizeof(struct in_addr)); MD5Update(&isn->ctx, (u_char *)&tp->t_inpcb->inp_laddr, sizeof(struct in_addr)); } MD5Final((char *)digest, &isn->ctx); /* * Add a random component 0-1048575 plus advance by 1048576. * * The sequence space is simply too small, in modern times we also * must depend on the receive-side being a bit smarter when recycling * ports in TIME_WAIT. */ read_random(&n, sizeof(n), 1); isn->last_offset += (n & 0x000FFFFF) + 0x00100000; new_isn = (digest[0] & 0x0FFFFFFF) + isn->last_offset; return (new_isn); } /* * When a source quench is received, close congestion window * to one segment. We will gradually open it again as we proceed. */ void tcp_quench(struct inpcb *inp, int error) { struct tcpcb *tp = intotcpcb(inp); KASSERT(tp != NULL, ("tcp_quench: tp is NULL")); tp->snd_cwnd = tp->t_maxseg; tp->snd_wacked = 0; } /* * When a specific ICMP unreachable message is received and the * connection state is SYN-SENT, drop the connection. This behavior * is controlled by the icmp_may_rst sysctl. */ void tcp_drop_syn_sent(struct inpcb *inp, int error) { struct tcpcb *tp = intotcpcb(inp); KASSERT(tp != NULL, ("tcp_drop_syn_sent: tp is NULL")); if (tp->t_state == TCPS_SYN_SENT) tcp_drop(tp, error); } /* * When a `need fragmentation' ICMP is received, update our idea of the MSS * based on the new value in the route. Also nudge TCP to send something, * since we know the packet we just sent was dropped. * This duplicates some code in the tcp_mss() function in tcp_input.c. */ void tcp_mtudisc(struct inpcb *inp, int mtu) { struct tcpcb *tp = intotcpcb(inp); struct rtentry *rt; struct socket *so = inp->inp_socket; int maxopd, mss; #ifdef INET6 boolean_t isipv6 = INP_ISIPV6(inp); #else const boolean_t isipv6 = FALSE; #endif KASSERT(tp != NULL, ("tcp_mtudisc: tp is NULL")); /* * If no MTU is provided in the ICMP message, use the * next lower likely value, as specified in RFC 1191. */ if (mtu == 0) { int oldmtu; oldmtu = tp->t_maxopd + (isipv6 ? sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : sizeof(struct tcpiphdr)); mtu = ip_next_mtu(oldmtu, 0); } if (isipv6) rt = tcp_rtlookup6(&inp->inp_inc); else rt = tcp_rtlookup(&inp->inp_inc); if (rt != NULL) { if (rt->rt_rmx.rmx_mtu != 0 && rt->rt_rmx.rmx_mtu < mtu) mtu = rt->rt_rmx.rmx_mtu; maxopd = mtu - (isipv6 ? sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : sizeof(struct tcpiphdr)); /* * XXX - The following conditional probably violates the TCP * spec. The problem is that, since we don't know the * other end's MSS, we are supposed to use a conservative * default. But, if we do that, then MTU discovery will * never actually take place, because the conservative * default is much less than the MTUs typically seen * on the Internet today. For the moment, we'll sweep * this under the carpet. * * The conservative default might not actually be a problem * if the only case this occurs is when sending an initial * SYN with options and data to a host we've never talked * to before. Then, they will reply with an MSS value which * will get recorded and the new parameters should get * recomputed. For Further Study. */ if (rt->rt_rmx.rmx_mssopt && rt->rt_rmx.rmx_mssopt < maxopd) maxopd = rt->rt_rmx.rmx_mssopt; } else maxopd = mtu - (isipv6 ? sizeof(struct ip6_hdr) + sizeof(struct tcphdr) : sizeof(struct tcpiphdr)); if (tp->t_maxopd <= maxopd) return; tp->t_maxopd = maxopd; mss = maxopd; if ((tp->t_flags & (TF_REQ_TSTMP | TF_RCVD_TSTMP | TF_NOOPT)) == (TF_REQ_TSTMP | TF_RCVD_TSTMP)) mss -= TCPOLEN_TSTAMP_APPA; /* round down to multiple of MCLBYTES */ #if (MCLBYTES & (MCLBYTES - 1)) == 0 /* test if MCLBYTES power of 2 */ if (mss > MCLBYTES) mss &= ~(MCLBYTES - 1); #else if (mss > MCLBYTES) mss = rounddown(mss, MCLBYTES); #endif if (so->so_snd.ssb_hiwat < mss) mss = so->so_snd.ssb_hiwat; tp->t_maxseg = mss; tp->t_rtttime = 0; tp->snd_nxt = tp->snd_una; tcp_output(tp); tcpstat.tcps_mturesent++; } /* * Look-up the routing entry to the peer of this inpcb. If no route * is found and it cannot be allocated the return NULL. This routine * is called by TCP routines that access the rmx structure and by tcp_mss * to get the interface MTU. */ struct rtentry * tcp_rtlookup(struct in_conninfo *inc) { struct route *ro = &inc->inc_route; if (ro->ro_rt == NULL || !(ro->ro_rt->rt_flags & RTF_UP)) { /* No route yet, so try to acquire one */ if (inc->inc_faddr.s_addr != INADDR_ANY) { /* * unused portions of the structure MUST be zero'd * out because rtalloc() treats it as opaque data */ bzero(&ro->ro_dst, sizeof(struct sockaddr_in)); ro->ro_dst.sa_family = AF_INET; ro->ro_dst.sa_len = sizeof(struct sockaddr_in); ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = inc->inc_faddr; rtalloc(ro); } } return (ro->ro_rt); } #ifdef INET6 struct rtentry * tcp_rtlookup6(struct in_conninfo *inc) { struct route_in6 *ro6 = &inc->inc6_route; if (ro6->ro_rt == NULL || !(ro6->ro_rt->rt_flags & RTF_UP)) { /* No route yet, so try to acquire one */ if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) { /* * unused portions of the structure MUST be zero'd * out because rtalloc() treats it as opaque data */ bzero(&ro6->ro_dst, sizeof(struct sockaddr_in6)); ro6->ro_dst.sin6_family = AF_INET6; ro6->ro_dst.sin6_len = sizeof(struct sockaddr_in6); ro6->ro_dst.sin6_addr = inc->inc6_faddr; rtalloc((struct route *)ro6); } } return (ro6->ro_rt); } #endif /* * TCP BANDWIDTH DELAY PRODUCT WINDOW LIMITING * * This code attempts to calculate the bandwidth-delay product as a * means of determining the optimal window size to maximize bandwidth, * minimize RTT, and avoid the over-allocation of buffers on interfaces and * routers. This code also does a fairly good job keeping RTTs in check * across slow links like modems. We implement an algorithm which is very * similar (but not meant to be) TCP/Vegas. The code operates on the * transmitter side of a TCP connection and so only effects the transmit * side of the connection. * * BACKGROUND: TCP makes no provision for the management of buffer space * at the end points or at the intermediate routers and switches. A TCP * stream, whether using NewReno or not, will eventually buffer as * many packets as it is able and the only reason this typically works is * due to the fairly small default buffers made available for a connection * (typicaly 16K or 32K). As machines use larger windows and/or window * scaling it is now fairly easy for even a single TCP connection to blow-out * all available buffer space not only on the local interface, but on * intermediate routers and switches as well. NewReno makes a misguided * attempt to 'solve' this problem by waiting for an actual failure to occur, * then backing off, then steadily increasing the window again until another * failure occurs, ad-infinitum. This results in terrible oscillation that * is only made worse as network loads increase and the idea of intentionally * blowing out network buffers is, frankly, a terrible way to manage network * resources. * * It is far better to limit the transmit window prior to the failure * condition being achieved. There are two general ways to do this: First * you can 'scan' through different transmit window sizes and locate the * point where the RTT stops increasing, indicating that you have filled the * pipe, then scan backwards until you note that RTT stops decreasing, then * repeat ad-infinitum. This method works in principle but has severe * implementation issues due to RTT variances, timer granularity, and * instability in the algorithm which can lead to many false positives and * create oscillations as well as interact badly with other TCP streams * implementing the same algorithm. * * The second method is to limit the window to the bandwidth delay product * of the link. This is the method we implement. RTT variances and our * own manipulation of the congestion window, bwnd, can potentially * destabilize the algorithm. For this reason we have to stabilize the * elements used to calculate the window. We do this by using the minimum * observed RTT, the long term average of the observed bandwidth, and * by adding two segments worth of slop. It isn't perfect but it is able * to react to changing conditions and gives us a very stable basis on * which to extend the algorithm. */ void tcp_xmit_bandwidth_limit(struct tcpcb *tp, tcp_seq ack_seq) { u_long bw; u_long ibw; u_long bwnd; int save_ticks; int delta_ticks; /* * If inflight_enable is disabled in the middle of a tcp connection, * make sure snd_bwnd is effectively disabled. */ if (!tcp_inflight_enable) { tp->snd_bwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; tp->snd_bandwidth = 0; return; } /* * Validate the delta time. If a connection is new or has been idle * a long time we have to reset the bandwidth calculator. */ save_ticks = ticks; cpu_ccfence(); delta_ticks = save_ticks - tp->t_bw_rtttime; if (tp->t_bw_rtttime == 0 || delta_ticks < 0 || delta_ticks > hz * 10) { tp->t_bw_rtttime = save_ticks; tp->t_bw_rtseq = ack_seq; if (tp->snd_bandwidth == 0) tp->snd_bandwidth = tcp_inflight_start; return; } /* * A delta of at least 1 tick is required. Waiting 2 ticks will * result in better (bw) accuracy. More than that and the ramp-up * will be too slow. */ if (delta_ticks == 0 || delta_ticks == 1) return; /* * Sanity check, plus ignore pure window update acks. */ if ((int)(ack_seq - tp->t_bw_rtseq) <= 0) return; /* * Figure out the bandwidth. Due to the tick granularity this * is a very rough number and it MUST be averaged over a fairly * long period of time. XXX we need to take into account a link * that is not using all available bandwidth, but for now our * slop will ramp us up if this case occurs and the bandwidth later * increases. */ ibw = (int64_t)(ack_seq - tp->t_bw_rtseq) * hz / delta_ticks; tp->t_bw_rtttime = save_ticks; tp->t_bw_rtseq = ack_seq; bw = ((int64_t)tp->snd_bandwidth * 15 + ibw) >> 4; tp->snd_bandwidth = bw; /* * Calculate the semi-static bandwidth delay product, plus two maximal * segments. The additional slop puts us squarely in the sweet * spot and also handles the bandwidth run-up case. Without the * slop we could be locking ourselves into a lower bandwidth. * * At very high speeds the bw calculation can become overly sensitive * and error prone when delta_ticks is low (e.g. usually 1). To deal * with the problem the stab must be scaled to the bw. A stab of 50 * (the default) increases the bw for the purposes of the bwnd * calculation by 5%. * * Situations Handled: * (1) Prevents over-queueing of packets on LANs, especially on * high speed LANs, allowing larger TCP buffers to be * specified, and also does a good job preventing * over-queueing of packets over choke points like modems * (at least for the transmit side). * * (2) Is able to handle changing network loads (bandwidth * drops so bwnd drops, bandwidth increases so bwnd * increases). * * (3) Theoretically should stabilize in the face of multiple * connections implementing the same algorithm (this may need * a little work). * * (4) Stability value (defaults to 20 = 2 maximal packets) can * be adjusted with a sysctl but typically only needs to be on * very slow connections. A value no smaller then 5 should * be used, but only reduce this default if you have no other * choice. */ #define USERTT ((tp->t_srtt + tp->t_rttvar) + tcp_inflight_adjrtt) bw += bw * tcp_inflight_stab / 1000; bwnd = (int64_t)bw * USERTT / (hz << TCP_RTT_SHIFT) + (int)tp->t_maxseg * 2; #undef USERTT if (tcp_inflight_debug > 0) { static int ltime; if ((u_int)(save_ticks - ltime) >= hz / tcp_inflight_debug) { ltime = save_ticks; kprintf("%p ibw %ld bw %ld rttvar %d srtt %d " "bwnd %ld delta %d snd_win %ld\n", tp, ibw, bw, tp->t_rttvar, tp->t_srtt, bwnd, delta_ticks, tp->snd_wnd); } } if ((long)bwnd < tcp_inflight_min) bwnd = tcp_inflight_min; if (bwnd > tcp_inflight_max) bwnd = tcp_inflight_max; if ((long)bwnd < tp->t_maxseg * 2) bwnd = tp->t_maxseg * 2; tp->snd_bwnd = bwnd; } static void tcp_rmx_iwsegs(struct tcpcb *tp, u_long *maxsegs, u_long *capsegs) { struct rtentry *rt; struct inpcb *inp = tp->t_inpcb; #ifdef INET6 boolean_t isipv6 = INP_ISIPV6(inp); #else const boolean_t isipv6 = FALSE; #endif /* XXX */ if (tcp_iw_maxsegs < TCP_IW_MAXSEGS_DFLT) tcp_iw_maxsegs = TCP_IW_MAXSEGS_DFLT; if (tcp_iw_capsegs < TCP_IW_CAPSEGS_DFLT) tcp_iw_capsegs = TCP_IW_CAPSEGS_DFLT; if (isipv6) rt = tcp_rtlookup6(&inp->inp_inc); else rt = tcp_rtlookup(&inp->inp_inc); if (rt == NULL || rt->rt_rmx.rmx_iwmaxsegs < TCP_IW_MAXSEGS_DFLT || rt->rt_rmx.rmx_iwcapsegs < TCP_IW_CAPSEGS_DFLT) { *maxsegs = tcp_iw_maxsegs; *capsegs = tcp_iw_capsegs; return; } *maxsegs = rt->rt_rmx.rmx_iwmaxsegs; *capsegs = rt->rt_rmx.rmx_iwcapsegs; } u_long tcp_initial_window(struct tcpcb *tp) { if (tcp_do_rfc3390) { /* * RFC3390: * "If the SYN or SYN/ACK is lost, the initial window * used by a sender after a correctly transmitted SYN * MUST be one segment consisting of MSS bytes." * * However, we do something a little bit more aggressive * then RFC3390 here: * - Only if time spent in the SYN or SYN|ACK retransmition * >= 3 seconds, the IW is reduced. We do this mainly * because when RFC3390 is published, the initial RTO is * still 3 seconds (the threshold we test here), while * after RFC6298, the initial RTO is 1 second. This * behaviour probably still falls within the spirit of * RFC3390. * - When IW is reduced, 2*MSS is used instead of 1*MSS. * Mainly to avoid sender and receiver deadlock until * delayed ACK timer expires. And even RFC2581 does not * try to reduce IW upon SYN or SYN|ACK retransmition * timeout. * * See also: * http://tools.ietf.org/html/draft-ietf-tcpm-initcwnd-03 */ if (tp->t_rxtsyn >= TCPTV_RTOBASE3) { return (2 * tp->t_maxseg); } else { u_long maxsegs, capsegs; tcp_rmx_iwsegs(tp, &maxsegs, &capsegs); return min(maxsegs * tp->t_maxseg, max(2 * tp->t_maxseg, capsegs * 1460)); } } else { /* * Even RFC2581 (back to 1999) allows 2*SMSS IW. * * Mainly to avoid sender and receiver deadlock * until delayed ACK timer expires. */ return (2 * tp->t_maxseg); } } #ifdef TCP_SIGNATURE /* * Compute TCP-MD5 hash of a TCP segment. (RFC2385) * * We do this over ip, tcphdr, segment data, and the key in the SADB. * When called from tcp_input(), we can be sure that th_sum has been * zeroed out and verified already. * * Return 0 if successful, otherwise return -1. * * XXX The key is retrieved from the system's PF_KEY SADB, by keying a * search with the destination IP address, and a 'magic SPI' to be * determined by the application. This is hardcoded elsewhere to 1179 * right now. Another branch of this code exists which uses the SPD to * specify per-application flows but it is unstable. */ int tcpsignature_compute( struct mbuf *m, /* mbuf chain */ int len, /* length of TCP data */ int optlen, /* length of TCP options */ u_char *buf, /* storage for MD5 digest */ u_int direction) /* direction of flow */ { struct ippseudo ippseudo; MD5_CTX ctx; int doff; struct ip *ip; struct ipovly *ipovly; struct secasvar *sav; struct tcphdr *th; #ifdef INET6 struct ip6_hdr *ip6; struct in6_addr in6; uint32_t plen; uint16_t nhdr; #endif /* INET6 */ u_short savecsum; KASSERT(m != NULL, ("passed NULL mbuf. Game over.")); KASSERT(buf != NULL, ("passed NULL storage pointer for MD5 signature")); /* * Extract the destination from the IP header in the mbuf. */ ip = mtod(m, struct ip *); #ifdef INET6 ip6 = NULL; /* Make the compiler happy. */ #endif /* INET6 */ /* * Look up an SADB entry which matches the address found in * the segment. */ switch (IP_VHL_V(ip->ip_vhl)) { case IPVERSION: sav = key_allocsa(AF_INET, (caddr_t)&ip->ip_src, (caddr_t)&ip->ip_dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); break; #ifdef INET6 case (IPV6_VERSION >> 4): ip6 = mtod(m, struct ip6_hdr *); sav = key_allocsa(AF_INET6, (caddr_t)&ip6->ip6_src, (caddr_t)&ip6->ip6_dst, IPPROTO_TCP, htonl(TCP_SIG_SPI)); break; #endif /* INET6 */ default: return (EINVAL); /* NOTREACHED */ break; } if (sav == NULL) { kprintf("%s: SADB lookup failed\n", __func__); return (EINVAL); } MD5Init(&ctx); /* * Step 1: Update MD5 hash with IP pseudo-header. * * XXX The ippseudo header MUST be digested in network byte order, * or else we'll fail the regression test. Assume all fields we've * been doing arithmetic on have been in host byte order. * XXX One cannot depend on ipovly->ih_len here. When called from * tcp_output(), the underlying ip_len member has not yet been set. */ switch (IP_VHL_V(ip->ip_vhl)) { case IPVERSION: ipovly = (struct ipovly *)ip; ippseudo.ippseudo_src = ipovly->ih_src; ippseudo.ippseudo_dst = ipovly->ih_dst; ippseudo.ippseudo_pad = 0; ippseudo.ippseudo_p = IPPROTO_TCP; ippseudo.ippseudo_len = htons(len + sizeof(struct tcphdr) + optlen); MD5Update(&ctx, (char *)&ippseudo, sizeof(struct ippseudo)); th = (struct tcphdr *)((u_char *)ip + sizeof(struct ip)); doff = sizeof(struct ip) + sizeof(struct tcphdr) + optlen; break; #ifdef INET6 /* * RFC 2385, 2.0 Proposal * For IPv6, the pseudo-header is as described in RFC 2460, namely the * 128-bit source IPv6 address, 128-bit destination IPv6 address, zero- * extended next header value (to form 32 bits), and 32-bit segment * length. * Note: Upper-Layer Packet Length comes before Next Header. */ case (IPV6_VERSION >> 4): in6 = ip6->ip6_src; in6_clearscope(&in6); MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); in6 = ip6->ip6_dst; in6_clearscope(&in6); MD5Update(&ctx, (char *)&in6, sizeof(struct in6_addr)); plen = htonl(len + sizeof(struct tcphdr) + optlen); MD5Update(&ctx, (char *)&plen, sizeof(uint32_t)); nhdr = 0; MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); nhdr = IPPROTO_TCP; MD5Update(&ctx, (char *)&nhdr, sizeof(uint8_t)); th = (struct tcphdr *)((u_char *)ip6 + sizeof(struct ip6_hdr)); doff = sizeof(struct ip6_hdr) + sizeof(struct tcphdr) + optlen; break; #endif /* INET6 */ default: return (EINVAL); /* NOTREACHED */ break; } /* * Step 2: Update MD5 hash with TCP header, excluding options. * The TCP checksum must be set to zero. */ savecsum = th->th_sum; th->th_sum = 0; MD5Update(&ctx, (char *)th, sizeof(struct tcphdr)); th->th_sum = savecsum; /* * Step 3: Update MD5 hash with TCP segment data. * Use m_apply() to avoid an early m_pullup(). */ if (len > 0) m_apply(m, doff, len, tcpsignature_apply, &ctx); /* * Step 4: Update MD5 hash with shared secret. */ MD5Update(&ctx, _KEYBUF(sav->key_auth), _KEYLEN(sav->key_auth)); MD5Final(buf, &ctx); key_sa_recordxfer(sav, m); key_freesav(sav); return (0); } int tcpsignature_apply(void *fstate, void *data, unsigned int len) { MD5Update((MD5_CTX *)fstate, (unsigned char *)data, len); return (0); } #endif /* TCP_SIGNATURE */ static void tcp_drop_sysctl_dispatch(netmsg_t nmsg) { struct lwkt_msg *lmsg = &nmsg->lmsg; /* addrs[0] is a foreign socket, addrs[1] is a local one. */ struct sockaddr_storage *addrs = lmsg->u.ms_resultp; int error; struct sockaddr_in *fin, *lin; #ifdef INET6 struct sockaddr_in6 *fin6, *lin6; struct in6_addr f6, l6; #endif struct inpcb *inp; switch (addrs[0].ss_family) { #ifdef INET6 case AF_INET6: fin6 = (struct sockaddr_in6 *)&addrs[0]; lin6 = (struct sockaddr_in6 *)&addrs[1]; error = in6_embedscope(&f6, fin6, NULL, NULL); if (error) goto done; error = in6_embedscope(&l6, lin6, NULL, NULL); if (error) goto done; inp = in6_pcblookup_hash(&tcbinfo[mycpuid], &f6, fin6->sin6_port, &l6, lin6->sin6_port, FALSE, NULL); break; #endif #ifdef INET case AF_INET: fin = (struct sockaddr_in *)&addrs[0]; lin = (struct sockaddr_in *)&addrs[1]; inp = in_pcblookup_hash(&tcbinfo[mycpuid], fin->sin_addr, fin->sin_port, lin->sin_addr, lin->sin_port, FALSE, NULL); break; #endif default: /* * Must not reach here, since the address family was * checked in sysctl handler. */ panic("unknown address family %d", addrs[0].ss_family); } if (inp != NULL) { struct tcpcb *tp = intotcpcb(inp); KASSERT((inp->inp_flags & INP_WILDCARD) == 0, ("in wildcard hash")); KASSERT(tp != NULL, ("tcp_drop_sysctl_dispatch: tp is NULL")); KASSERT((tp->t_flags & TF_LISTEN) == 0, ("listen socket")); tcp_drop(tp, ECONNABORTED); error = 0; } else { error = ESRCH; } #ifdef INET6 done: #endif lwkt_replymsg(lmsg, error); } static int sysctl_tcp_drop(SYSCTL_HANDLER_ARGS) { /* addrs[0] is a foreign socket, addrs[1] is a local one. */ struct sockaddr_storage addrs[2]; struct sockaddr_in *fin, *lin; #ifdef INET6 struct sockaddr_in6 *fin6, *lin6; #endif struct netmsg_base nmsg; struct lwkt_msg *lmsg = &nmsg.lmsg; struct lwkt_port *port = NULL; int error; fin = lin = NULL; #ifdef INET6 fin6 = lin6 = NULL; #endif error = 0; if (req->oldptr != NULL || req->oldlen != 0) return (EINVAL); if (req->newptr == NULL) return (EPERM); if (req->newlen < sizeof(addrs)) return (ENOMEM); error = SYSCTL_IN(req, &addrs, sizeof(addrs)); if (error) return (error); switch (addrs[0].ss_family) { #ifdef INET6 case AF_INET6: fin6 = (struct sockaddr_in6 *)&addrs[0]; lin6 = (struct sockaddr_in6 *)&addrs[1]; if (fin6->sin6_len != sizeof(struct sockaddr_in6) || lin6->sin6_len != sizeof(struct sockaddr_in6)) return (EINVAL); if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr) || IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr)) return (EADDRNOTAVAIL); #if 0 error = sa6_embedscope(fin6, V_ip6_use_defzone); if (error) return (error); error = sa6_embedscope(lin6, V_ip6_use_defzone); if (error) return (error); #endif port = tcp6_addrport(); break; #endif #ifdef INET case AF_INET: fin = (struct sockaddr_in *)&addrs[0]; lin = (struct sockaddr_in *)&addrs[1]; if (fin->sin_len != sizeof(struct sockaddr_in) || lin->sin_len != sizeof(struct sockaddr_in)) return (EINVAL); port = tcp_addrport(fin->sin_addr.s_addr, fin->sin_port, lin->sin_addr.s_addr, lin->sin_port); break; #endif default: return (EINVAL); } netmsg_init(&nmsg, NULL, &curthread->td_msgport, 0, tcp_drop_sysctl_dispatch); lmsg->u.ms_resultp = addrs; return lwkt_domsg(port, lmsg, 0); } SYSCTL_PROC(_net_inet_tcp, OID_AUTO, drop, CTLTYPE_STRUCT | CTLFLAG_WR | CTLFLAG_SKIP, NULL, 0, sysctl_tcp_drop, "", "Drop TCP connection"); static int sysctl_tcps_count(SYSCTL_HANDLER_ARGS) { u_long state_count[TCP_NSTATES]; int cpu; memset(state_count, 0, sizeof(state_count)); for (cpu = 0; cpu < netisr_ncpus; ++cpu) { int i; for (i = 0; i < TCP_NSTATES; ++i) state_count[i] += tcpstate_count[cpu].tcps_count[i]; } return sysctl_handle_opaque(oidp, state_count, sizeof(state_count), req); } SYSCTL_PROC(_net_inet_tcp, OID_AUTO, state_count, CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0, sysctl_tcps_count, "LU", "TCP connection counts by state"); void tcp_pcbport_create(struct tcpcb *tp) { int cpu; KASSERT((tp->t_flags & TF_LISTEN) && tp->t_state == TCPS_LISTEN, ("not a listen tcpcb")); KASSERT(tp->t_pcbport == NULL, ("tcpcb port cache was created")); tp->t_pcbport = kmalloc(sizeof(struct tcp_pcbport) * netisr_ncpus, M_PCB, M_WAITOK | M_CACHEALIGN); for (cpu = 0; cpu < netisr_ncpus; ++cpu) { struct inpcbport *phd; phd = &tp->t_pcbport[cpu].t_phd; LIST_INIT(&phd->phd_pcblist); /* Though, not used ... */ phd->phd_port = tp->t_inpcb->inp_lport; } } void tcp_pcbport_merge_oncpu(struct tcpcb *tp) { struct inpcbport *phd; struct inpcb *inp; int cpu = mycpuid; KASSERT(cpu < netisr_ncpus, ("invalid cpu%d", cpu)); phd = &tp->t_pcbport[cpu].t_phd; while ((inp = LIST_FIRST(&phd->phd_pcblist)) != NULL) { KASSERT(inp->inp_phd == phd && inp->inp_porthash == NULL, ("not on tcpcb port cache")); LIST_REMOVE(inp, inp_portlist); in_pcbinsporthash_lport(inp); KASSERT(inp->inp_phd == tp->t_inpcb->inp_phd && inp->inp_porthash == tp->t_inpcb->inp_porthash, ("tcpcb port cache merge failed")); } } void tcp_pcbport_destroy(struct tcpcb *tp) { #ifdef INVARIANTS int cpu; for (cpu = 0; cpu < netisr_ncpus; ++cpu) { KASSERT(LIST_EMPTY(&tp->t_pcbport[cpu].t_phd.phd_pcblist), ("tcpcb port cache is not empty")); } #endif kfree(tp->t_pcbport, M_PCB); tp->t_pcbport = NULL; }