/bsd/sys/netinet/tcp_subr.cc
C++ | 2284 lines | 1630 code | 214 blank | 440 comment | 345 complexity | 824f0618819a3e16373872efd1e2e6e2 MD5 | raw file
Possible License(s): BSD-3-Clause, 0BSD, MPL-2.0-no-copyleft-exception
- /*-
- * 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.
- * 4. 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
- */
- #include <sys/cdefs.h>
- #include <bsd/porting/netport.h>
- #include <bsd/sys/sys/libkern.h>
- #include <bsd/sys/sys/param.h>
- #include <bsd/sys/sys/mbuf.h>
- #ifdef INET6
- #include <bsd/sys/sys/domain.h>
- #endif
- #include <bsd/sys/sys/priv.h>
- #include <bsd/sys/sys/socket.h>
- #include <bsd/sys/sys/socketvar.h>
- #include <bsd/sys/sys/protosw.h>
- #include <bsd/sys/net/route.h>
- #include <bsd/sys/net/if.h>
- #include <bsd/sys/net/vnet.h>
- #include <bsd/sys/netinet/cc.h>
- #include <bsd/sys/netinet/in.h>
- #include <bsd/sys/netinet/in_pcb.h>
- #include <bsd/sys/netinet/in_systm.h>
- #include <bsd/sys/netinet/in_var.h>
- #include <bsd/sys/netinet/ip.h>
- #include <bsd/sys/netinet/ip_icmp.h>
- #include <bsd/sys/netinet/ip_var.h>
- #ifdef INET6
- #include <bsd/sys/netinet/ip6.h>
- #include <bsd/sys/netinet6/in6_pcb.h>
- #include <bsd/sys/netinet6/ip6_var.h>
- #include <bsd/sys/netinet6/scope6_var.h>
- #include <bsd/sys/netinet6/nd6.h>
- #endif
- #include <bsd/sys/netinet/tcp_fsm.h>
- #include <bsd/sys/netinet/tcp_seq.h>
- #include <bsd/sys/netinet/tcp_timer.h>
- #include <bsd/sys/netinet/tcp_var.h>
- #include <bsd/sys/netinet/tcp_syncache.h>
- #ifdef INET6
- #include <bsd/sys/netinet6/tcp6_var.h>
- #endif
- #include <bsd/sys/netinet/tcpip.h>
- #ifdef TCPDEBUG
- #include <bsd/sys/netinet/tcp_debug.h>
- #endif
- #ifdef INET6
- #include <bsd/sys/netinet6/ip6protosw.h>
- #endif
- #ifdef IPSEC
- #include <netipsec/ipsec.h>
- #include <netipsec/xform.h>
- #ifdef INET6
- #include <netipsec/ipsec6.h>
- #endif
- #include <netipsec/key.h>
- #include <sys/syslog.h>
- #endif /*IPSEC*/
- #include <machine/in_cksum.h>
- #include <bsd/sys/sys/md5.h>
- #include <bsd/sys/net/routecache.hh>
- VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
- #ifdef INET6
- VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
- #endif
- #if 0
- static int
- sysctl_net_inet_tcp_mss_check(SYSCTL_HANDLER_ARGS)
- {
- int error, new;
- new = V_tcp_mssdflt;
- error = sysctl_handle_int(oidp, &new, 0, req);
- if (error == 0 && req->newptr) {
- if (new < TCP_MINMSS)
- error = EINVAL;
- else
- V_tcp_mssdflt = new;
- }
- return (error);
- }
- SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
- CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
- &sysctl_net_inet_tcp_mss_check, "I",
- "Default TCP Maximum Segment Size");
- #endif
- #ifdef INET6
- static int
- sysctl_net_inet_tcp_mss_v6_check(SYSCTL_HANDLER_ARGS)
- {
- int error, new;
- new = V_tcp_v6mssdflt;
- error = sysctl_handle_int(oidp, &new, 0, req);
- if (error == 0 && req->newptr) {
- if (new < TCP_MINMSS)
- error = EINVAL;
- else
- V_tcp_v6mssdflt = new;
- }
- return (error);
- }
- SYSCTL_VNET_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
- CTLTYPE_INT|CTLFLAG_RW, &VNET_NAME(tcp_v6mssdflt), 0,
- &sysctl_net_inet_tcp_mss_v6_check, "I",
- "Default TCP Maximum Segment Size for IPv6");
- #endif /* INET6 */
- /*
- * 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.
- */
- VNET_DEFINE(int, tcp_minmss) = TCP_MINMSS;
- SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_RW,
- &VNET_NAME(tcp_minmss), 0,
- "Minmum TCP Maximum Segment Size");
- VNET_DEFINE(int, tcp_do_rfc1323) = 1;
- SYSCTL_VNET_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_RW,
- &VNET_NAME(tcp_do_rfc1323), 0,
- "Enable rfc1323 (high performance TCP) extensions");
- static int tcp_log_debug = 0;
- SYSCTL_INT(_net_inet_tcp, OID_AUTO, log_debug, CTLFLAG_RW,
- &tcp_log_debug, 0, "Log errors caused by incoming TCP segments");
- static int tcp_tcbhashsize = 0;
- SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN,
- &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");
- SYSCTL_VNET_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_RD,
- &VNET_NAME(tcbinfo.ipi_count), 0, "Number of active PCBs");
- static VNET_DEFINE(int, icmp_may_rst) = 1;
- #define V_icmp_may_rst VNET(icmp_may_rst)
- SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_RW,
- &VNET_NAME(icmp_may_rst), 0,
- "Certain ICMP unreachable messages may abort connections in SYN_SENT");
- static VNET_DEFINE(int, tcp_isn_reseed_interval) = 0;
- #define V_tcp_isn_reseed_interval VNET(tcp_isn_reseed_interval)
- SYSCTL_VNET_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_RW,
- &VNET_NAME(tcp_isn_reseed_interval), 0,
- "Seconds between reseeding of ISN secret");
- static int tcp_soreceive_stream = 0;
- SYSCTL_INT(_net_inet_tcp, OID_AUTO, soreceive_stream, CTLFLAG_RDTUN,
- &tcp_soreceive_stream, 0, "Using soreceive_stream for TCP sockets");
- #ifdef TCP_SIGNATURE
- static int tcp_sig_checksigs = 1;
- SYSCTL_INT(_net_inet_tcp, OID_AUTO, signature_verify_input, CTLFLAG_RW,
- &tcp_sig_checksigs, 0, "Verify RFC2385 digests on inbound traffic");
- #endif
- VNET_DEFINE(uma_zone_t, sack_hole_zone);
- #define V_sack_hole_zone VNET(sack_hole_zone)
- VNET_DEFINE(struct hhook_head *, tcp_hhh[HHOOK_TCP_LAST+1]);
- static struct inpcb *tcp_notify(struct inpcb *, int);
- static struct inpcb *tcp_mtudisc_notify(struct inpcb *, int);
- static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
- void *ip4hdr, const void *ip6hdr);
- /*
- * 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 4096
- #endif
- /*
- * XXX
- * Callouts should be moved into struct tcp directly. They are currently
- * separate because the tcpcb structure is exported to userland for sysctl
- * parsing purposes, which do not know about callouts.
- */
- struct tcpcb_mem {
- struct tcpcb tcb;
- struct tcp_timer tt;
- struct cc_var ccv;
- };
- static VNET_DEFINE(uma_zone_t, tcpcb_zone);
- #define V_tcpcb_zone VNET(tcpcb_zone)
- MALLOC_DEFINE(M_TCPLOG, "tcplog", "TCP address and flags print buffers");
- static struct mtx isn_mtx;
- #define ISN_LOCK_INIT() mtx_init(&isn_mtx, "isn_mtx", NULL, MTX_DEF)
- #define ISN_LOCK() mtx_lock(&isn_mtx)
- #define ISN_UNLOCK() mtx_unlock(&isn_mtx)
- /*
- * TCP initialization.
- */
- static void
- tcp_zone_change(void *tag)
- {
- // FIXME: uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
- uma_zone_set_max(V_tcpcb_zone, maxsockets);
- tcp_tw_zone_change();
- }
- void
- tcp_init(void)
- {
- int hashsize;
- hashsize = TCBHASHSIZE;
- TUNABLE_INT_FETCH("net.inet.tcp.tcbhashsize", &hashsize);
- if (!powerof2(hashsize)) {
- printf("WARNING: TCB hash size not a power of 2\n");
- hashsize = 512; /* safe default */
- }
- in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
- IPI_HASHFIELDS_4TUPLE);
- /*
- * These have to be type stable for the benefit of the timers.
- */
- V_tcpcb_zone = uma_zcreate("tcpcb", sizeof(struct tcpcb_mem),
- NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
- uma_zone_set_max(V_tcpcb_zone, maxsockets);
- tcp_tw_init();
- syncache_init();
- tcp_hc_init();
- tcp_reass_init();
- TUNABLE_INT_FETCH("net.inet.tcp.sack.enable", &V_tcp_do_sack);
- V_sack_hole_zone = uma_zcreate("sackhole", sizeof(struct sackhole),
- NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
- /* Skip initialization of globals for non-default instances. */
- if (!IS_DEFAULT_VNET(curvnet))
- return;
- /* XXX virtualize those below? */
- tcp_delacktime = TCPTV_DELACK;
- tcp_keepinit = TCPTV_KEEP_INIT;
- tcp_keepidle = (int)TCPTV_KEEP_IDLE;
- tcp_keepintvl = TCPTV_KEEPINTVL;
- tcp_maxpersistidle = (int)TCPTV_KEEP_IDLE;
- tcp_msl = TCPTV_MSL;
- tcp_rexmit_min = TCPTV_MIN;
- if (tcp_rexmit_min < 1)
- tcp_rexmit_min = 1;
- tcp_rexmit_slop = TCPTV_CPU_VAR;
- tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
- tcp_tcbhashsize = hashsize;
- TUNABLE_INT_FETCH("net.inet.tcp.soreceive_stream", &tcp_soreceive_stream);
- if (tcp_soreceive_stream) {
- #ifdef INET
- tcp_usrreqs.pru_soreceive = soreceive_stream;
- #endif
- #ifdef INET6
- tcp6_usrreqs.pru_soreceive = soreceive_stream;
- #endif /* INET6 */
- }
- #ifdef INET6
- #define TCP_MINPROTOHDR (sizeof(struct ip6_hdr) + sizeof(struct tcphdr))
- #else /* INET6 */
- #define TCP_MINPROTOHDR (sizeof(struct tcpiphdr))
- #endif /* INET6 */
- if (max_protohdr < TCP_MINPROTOHDR)
- max_protohdr = TCP_MINPROTOHDR;
- if (max_linkhdr + TCP_MINPROTOHDR > MHLEN)
- panic("tcp_init");
- #undef TCP_MINPROTOHDR
- ISN_LOCK_INIT();
- /* FIXME: OSv - tcp shutdown event */
- #if 0
- EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
- SHUTDOWN_PRI_DEFAULT);
- #endif
- EVENTHANDLER_REGISTER(maxsockets_change, (void *)tcp_zone_change, NULL,
- EVENTHANDLER_PRI_ANY);
- }
- #ifdef VIMAGE
- void
- tcp_destroy(void)
- {
- tcp_reass_destroy();
- tcp_hc_destroy();
- syncache_destroy();
- tcp_tw_destroy();
- in_pcbinfo_destroy(&V_tcbinfo);
- uma_zdestroy(V_sack_hole_zone);
- uma_zdestroy(V_tcpcb_zone);
- }
- #endif
- void
- tcp_fini(void *xtp)
- {
- }
- /*
- * 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
- tcpip_fillheaders(struct inpcb *inp, void *ip_ptr, void *tcp_ptr)
- {
- struct tcphdr *th = (struct tcphdr *)tcp_ptr;
- INP_LOCK_ASSERT(inp);
- #ifdef INET6
- if ((inp->inp_vflag & INP_IPV6) != 0) {
- struct ip6_hdr *ip6;
- ip6 = (struct ip6_hdr *)ip_ptr;
- ip6->ip6_flow = (ip6->ip6_flow & ~IPV6_FLOWINFO_MASK) |
- (inp->inp_flow & 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 = htons(sizeof(struct tcphdr));
- ip6->ip6_src = inp->in6p_laddr;
- ip6->ip6_dst = inp->in6p_faddr;
- }
- #endif /* INET6 */
- #if defined(INET6) && defined(INET)
- else
- #endif
- #ifdef INET
- {
- struct ip *ip;
- ip = (struct ip *)ip_ptr;
- ip->ip_v = IPVERSION;
- ip->ip_hl = 5;
- ip->ip_tos = inp->inp_ip_tos;
- ip->ip_len = 0;
- ip->ip_id = 0;
- ip->ip_off = 0;
- ip->ip_ttl = inp->inp_ip_ttl;
- ip->ip_sum = 0;
- ip->ip_p = IPPROTO_TCP;
- ip->ip_src = inp->inp_laddr;
- ip->ip_dst = inp->inp_faddr;
- }
- #endif /* INET */
- th->th_sport = inp->inp_lport;
- th->th_dport = inp->inp_fport;
- th->th_seq = tcp_seq(0);
- th->th_ack = tcp_seq(0);
- th->th_x2 = 0;
- th->th_off = 5;
- th->th_flags = 0;
- th->th_win = 0;
- th->th_urp = 0;
- th->th_sum = 0; /* in_pseudo() is called later for ipv4 */
- }
- /*
- * 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 *
- tcpip_maketemplate(struct inpcb *inp)
- {
- struct tcptemp *t;
- t = (tcptemp *)malloc(sizeof(*t));
- if (t == NULL)
- return (NULL);
- tcpip_fillheaders(inp, (void *)&t->tt_ipgen, (void *)&t->tt_t);
- return (t);
- }
- /*
- * 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;
- int win = 0;
- struct ip *ip;
- struct tcphdr *nth;
- #ifdef INET6
- struct ip6_hdr *ip6;
- int isipv6;
- #endif /* INET6 */
- int ipflags = 0;
- struct inpcb *inp;
- KASSERT(tp != NULL || m != NULL, ("tcp_respond: tp and m both NULL"));
- #ifdef INET6
- isipv6 = ((struct ip *)ipgen)->ip_v == (IPV6_VERSION >> 4);
- ip6 = ipgen;
- #endif /* INET6 */
- ip = (struct ip *)ipgen;
- if (tp != NULL) {
- inp = tp->t_inpcb;
- KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
- INP_LOCK_ASSERT(inp);
- } else
- inp = NULL;
- if (tp != NULL) {
- if (!(flags & TH_RST)) {
- win = sbspace(&inp->inp_socket->so_rcv);
- if (win > (long)TCP_MAXWIN << tp->rcv_scale)
- win = (long)TCP_MAXWIN << tp->rcv_scale;
- }
- }
- if (m == NULL) {
- m = m_gethdr(M_DONTWAIT, MT_DATA);
- if (m == NULL)
- return;
- tlen = 0;
- m->m_hdr.mh_data += max_linkhdr;
- #ifdef INET6
- if (isipv6) {
- bcopy((caddr_t)ip6, mtod(m, caddr_t),
- sizeof(struct ip6_hdr));
- ip6 = mtod(m, struct ip6_hdr *);
- nth = (struct tcphdr *)(ip6 + 1);
- } else
- #endif /* INET6 */
- {
- bcopy((caddr_t)ip, mtod(m, caddr_t), sizeof(struct ip));
- ip = mtod(m, struct ip *);
- nth = (struct tcphdr *)(ip + 1);
- }
- bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
- flags = TH_ACK;
- } else {
- /*
- * reuse the mbuf.
- * XXX MRT We inherrit the FIB, which is lucky.
- */
- m_freem(m->m_hdr.mh_next);
- m->m_hdr.mh_next = NULL;
- m->m_hdr.mh_data = (caddr_t)ipgen;
- m_addr_changed(m);
- /* m_hdr.mh_len is set later */
- tlen = 0;
- #define xchg(a,b,type) { type t; t=a; a=b; b=t; }
- #ifdef INET6
- if (isipv6) {
- xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
- nth = (struct tcphdr *)(ip6 + 1);
- } else
- #endif /* INET6 */
- {
- xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
- 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, uint16_t);
- #undef xchg
- }
- #ifdef INET6
- if (isipv6) {
- ip6->ip6_flow = 0;
- ip6->ip6_vfc = IPV6_VERSION;
- ip6->ip6_nxt = IPPROTO_TCP;
- ip6->ip6_plen = 0; /* Set in ip6_output(). */
- tlen += sizeof (struct ip6_hdr) + sizeof (struct tcphdr);
- }
- #endif
- #if defined(INET) && defined(INET6)
- else
- #endif
- #ifdef INET
- {
- tlen += sizeof (struct tcpiphdr);
- ip->ip_len = tlen;
- ip->ip_ttl = V_ip_defttl;
- if (V_path_mtu_discovery)
- ip->ip_off |= IP_DF;
- }
- #endif
- m->m_hdr.mh_len = tlen;
- m->M_dat.MH.MH_pkthdr.len = tlen;
- m->M_dat.MH.MH_pkthdr.rcvif = NULL;
- #ifdef MAC
- if (inp != NULL) {
- /*
- * Packet is associated with a socket, so allow the
- * label of the response to reflect the socket label.
- */
- INP_LOCK_ASSERT(inp);
- mac_inpcb_create_mbuf(inp, m);
- } else {
- /*
- * Packet is not associated with a socket, so possibly
- * update the label in place.
- */
- mac_netinet_tcp_reply(m);
- }
- #endif
- 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;
- m->M_dat.MH.MH_pkthdr.csum_data = offsetof(struct tcphdr, th_sum);
- #ifdef INET6
- if (isipv6) {
- m->M_dat.MH.MH_pkthdr.csum_flags = CSUM_TCP_IPV6;
- nth->th_sum = in6_cksum_pseudo(ip6,
- tlen - sizeof(struct ip6_hdr), IPPROTO_TCP, 0);
- ip6->ip6_hlim = in6_selecthlim(tp != NULL ? tp->t_inpcb :
- NULL, NULL);
- }
- #endif /* INET6 */
- #if defined(INET6) && defined(INET)
- else
- #endif
- #ifdef INET
- {
- m->M_dat.MH.MH_pkthdr.csum_flags = CSUM_TCP;
- 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)));
- }
- #endif /* INET */
- #ifdef TCPDEBUG
- if (tp == NULL || (inp->inp_socket->so_options & SO_DEBUG))
- tcp_trace(TA_OUTPUT, 0, tp, mtod(m, void *), th, 0);
- #endif
- #ifdef INET6
- if (isipv6)
- (void) ip6_output(m, NULL, NULL, ipflags, NULL, NULL, inp);
- #endif /* INET6 */
- #if defined(INET) && defined(INET6)
- else
- #endif
- #ifdef INET
- (void) ip_output(m, NULL, NULL, ipflags, NULL, inp);
- #endif
- }
- /*
- * 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().
- */
- struct tcpcb *
- tcp_newtcpcb(struct inpcb *inp)
- {
- struct tcpcb_mem *tm;
- struct tcpcb *tp;
- #ifdef INET6
- int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
- #endif /* INET6 */
- tm = (tcpcb_mem *)uma_zalloc(V_tcpcb_zone, M_NOWAIT | M_ZERO);
- if (tm == NULL)
- return (NULL);
- tp = &tm->tcb;
- /* Initialise cc_var struct for this tcpcb. */
- tp->ccv = &tm->ccv;
- tp->ccv->type = IPPROTO_TCP;
- tp->ccv->ccvc.tcp = tp;
- /*
- * Use the current system default CC algorithm.
- */
- CC_LIST_RLOCK();
- KASSERT(!STAILQ_EMPTY(&cc_list), ("cc_list is empty!"));
- CC_ALGO(tp) = CC_DEFAULT();
- CC_LIST_RUNLOCK();
- if (CC_ALGO(tp)->cb_init != NULL)
- if (CC_ALGO(tp)->cb_init(tp->ccv) > 0) {
- uma_zfree(V_tcpcb_zone, tm);
- return (NULL);
- }
- #ifdef VIMAGE
- tp->t_vnet = inp->inp_vnet;
- #endif
- tp->t_timers = &tm->tt;
- /* LIST_INIT(&tp->t_segq); */ /* XXX covered by M_ZERO */
- tp->t_maxseg = tp->t_maxopd =
- #ifdef INET6
- isipv6 ? V_tcp_v6mssdflt :
- #endif /* INET6 */
- V_tcp_mssdflt;
- init_timers(tp->t_timers, tp, inp);
- if (V_tcp_do_rfc1323)
- tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP);
- if (V_tcp_do_sack)
- tp->t_flags |= TF_SACK_PERMIT;
- TAILQ_INIT(&tp->snd_holes);
- tp->t_inpcb = inp; /* XXX */
- /*
- * 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_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT;
- tp->t_rcvtime = bsd_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 = V_ip_defttl;
- inp->inp_ppcb = tp;
- return (tp); /* XXX */
- }
- /*
- * Switch the congestion control algorithm back to NewReno for any active
- * control blocks using an algorithm which is about to go away.
- * This ensures the CC framework can allow the unload to proceed without leaving
- * any dangling pointers which would trigger a panic.
- * Returning non-zero would inform the CC framework that something went wrong
- * and it would be unsafe to allow the unload to proceed. However, there is no
- * way for this to occur with this implementation so we always return zero.
- */
- int
- tcp_ccalgounload(struct cc_algo *unload_algo)
- {
- struct cc_algo *tmpalgo;
- struct inpcb *inp;
- struct tcpcb *tp;
- VNET_ITERATOR_DECL(vnet_iter);
- /*
- * Check all active control blocks across all network stacks and change
- * any that are using "unload_algo" back to NewReno. If "unload_algo"
- * requires cleanup code to be run, call it.
- */
- VNET_LIST_RLOCK();
- VNET_FOREACH(vnet_iter) {
- CURVNET_SET(vnet_iter);
- INP_INFO_WLOCK(&V_tcbinfo);
- /*
- * New connections already part way through being initialised
- * with the CC algo we're removing will not race with this code
- * because the INP_INFO_WLOCK is held during initialisation. We
- * therefore don't enter the loop below until the connection
- * list has stabilised.
- */
- LIST_FOREACH(inp, &V_tcb, inp_list) {
- INP_LOCK(inp);
- /* Important to skip tcptw structs. */
- if (!(inp->inp_flags & INP_TIMEWAIT) &&
- (tp = intotcpcb(inp)) != NULL) {
- /*
- * By holding INP_LOCK here, we are assured
- * that the connection is not currently
- * executing inside the CC module's functions
- * i.e. it is safe to make the switch back to
- * NewReno.
- */
- if (CC_ALGO(tp) == unload_algo) {
- tmpalgo = CC_ALGO(tp);
- /* NewReno does not require any init. */
- CC_ALGO(tp) = &newreno_cc_algo;
- if (tmpalgo->cb_destroy != NULL)
- tmpalgo->cb_destroy(tp->ccv);
- }
- }
- INP_UNLOCK(inp);
- }
- INP_INFO_WUNLOCK(&V_tcbinfo);
- CURVNET_RESTORE();
- }
- VNET_LIST_RUNLOCK();
- return (0);
- }
- /*
- * Drop a TCP connection, reporting
- * the specified error. If connection is synchronized,
- * then send a RST to peer.
- */
- void tcp_drop_noclose(struct tcpcb *tp, int errval)
- {
- struct socket *so = tp->t_inpcb->inp_socket;
- INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
- INP_LOCK_ASSERT(tp->t_inpcb);
- if (TCPS_HAVERCVDSYN(tp->get_state())) {
- tp->set_state(TCPS_CLOSED);
- (void) tcp_output(tp);
- TCPSTAT_INC(tcps_drops);
- } else
- TCPSTAT_INC(tcps_conndrops);
- if (errval == ETIMEDOUT && tp->t_softerror)
- errval = tp->t_softerror;
- so->so_error = errval;
- }
- struct tcpcb *
- tcp_drop(struct tcpcb *tp, int errval)
- {
- tcp_drop_noclose(tp, errval);
- return tcp_close(tp);
- }
- void
- tcp_discardcb(struct tcpcb *tp)
- {
- struct inpcb *inp = tp->t_inpcb;
- struct socket *so = inp->inp_socket;
- #ifdef INET6
- int isipv6 = (inp->inp_vflag & INP_IPV6) != 0;
- #endif /* INET6 */
- INP_LOCK_ASSERT(inp);
- for (auto& t : *tp->t_timers) {
- t->cancel();
- }
- /*
- * If we got enough samples through the srtt filter,
- * save the rtt and rttvar in the routing entry.
- * 'Enough' is arbitrarily defined as 4 rtt samples.
- * 4 samples is enough for the srtt filter to converge
- * to within enough % of the correct value; fewer samples
- * and we could save a bogus rtt. The danger is not high
- * as tcp quickly recovers from everything.
- * XXX: Works very well but needs some more statistics!
- */
- if (tp->t_rttupdated >= 4) {
- struct hc_metrics_lite metrics;
- u_long ssthresh;
- bzero(&metrics, sizeof(metrics));
- /*
- * Update the ssthresh always when the conditions below
- * are satisfied. This gives us better new start value
- * for the congestion avoidance for new connections.
- * ssthresh is only set if packet loss occured on a session.
- *
- * XXXRW: 'so' may be NULL here, and/or socket buffer may be
- * being torn down. Ideally this code would not use 'so'.
- */
- ssthresh = tp->snd_ssthresh;
- if (ssthresh != 0 && ssthresh < so->so_snd.sb_hiwat / 2) {
- /*
- * convert the limit from user data bytes to
- * packets then to packet data bytes.
- */
- ssthresh = (ssthresh + tp->t_maxseg / 2) / tp->t_maxseg;
- if (ssthresh < 2)
- ssthresh = 2;
- ssthresh *= (u_long)(tp->t_maxseg +
- #ifdef INET6
- (isipv6 ? sizeof (struct ip6_hdr) +
- sizeof (struct tcphdr) :
- #endif
- sizeof (struct tcpiphdr)
- #ifdef INET6
- )
- #endif
- );
- } else
- ssthresh = 0;
- metrics.rmx_ssthresh = ssthresh;
- metrics.rmx_rtt = tp->t_srtt;
- metrics.rmx_rttvar = tp->t_rttvar;
- metrics.rmx_cwnd = tp->snd_cwnd;
- metrics.rmx_sendpipe = 0;
- metrics.rmx_recvpipe = 0;
- tcp_hc_update(&inp->inp_inc, &metrics);
- }
- /* free the reassembly queue, if any */
- tcp_reass_flush(tp);
-
- tcp_free_sackholes(tp);
- tcp_free_net_channel(tp);
- /* Allow the CC algorithm to clean up after itself. */
- if (CC_ALGO(tp)->cb_destroy != NULL)
- CC_ALGO(tp)->cb_destroy(tp->ccv);
- CC_ALGO(tp) = NULL;
- inp->inp_ppcb = NULL;
- /*
- * We must prevent inpcb from being freed until all
- * timers are stopped because they try to take a lock on it.
- */
- in_pcbref(tp->t_inpcb);
- async::run_later([inp, tp] {
- INP_LOCK(inp);
- for (auto& t : *tp->t_timers) {
- t->cancel_sync();
- delete t;
- }
- if (!in_pcbrele_locked(inp)) {
- INP_UNLOCK(inp);
- }
- tp->t_inpcb = NULL;
- uma_zfree(V_tcpcb_zone, tp);
- });
- }
- /*
- * Attempt to close a TCP control block, marking it as dropped, and freeing
- * the socket if we hold the only reference.
- */
- struct tcpcb *
- tcp_close(struct tcpcb *tp)
- {
- struct inpcb *inp = tp->t_inpcb;
- struct socket *so;
- INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
- INP_LOCK_ASSERT(inp);
- in_pcbdrop(inp);
- TCPSTAT_INC(tcps_closed);
- KASSERT(inp->inp_socket != NULL, ("tcp_close: inp_socket NULL"));
- so = inp->inp_socket;
- soisdisconnected(so);
- if (inp->inp_flags & INP_SOCKREF) {
- KASSERT(so->so_state & SS_PROTOREF,
- ("tcp_close: !SS_PROTOREF"));
- inp->inp_flags &= ~INP_SOCKREF;
- INP_UNLOCK(inp);
- ACCEPT_LOCK();
- SOCK_LOCK(so);
- so->so_state &= ~SS_PROTOREF;
- sofree(so);
- return (NULL);
- }
- return (tp);
- }
- void
- tcp_drain(void)
- {
- VNET_ITERATOR_DECL(vnet_iter);
- if (!do_tcpdrain)
- return;
- VNET_LIST_RLOCK_NOSLEEP();
- VNET_FOREACH(vnet_iter) {
- CURVNET_SET(vnet_iter);
- struct inpcb *inpb;
- struct tcpcb *tcpb;
- /*
- * Walk the tcpbs, if existing, and flush the reassembly queue,
- * if there is one...
- * XXX: The "Net/3" implementation doesn't imply that the TCP
- * reassembly queue should be flushed, but in a situation
- * where we're really low on mbufs, this is potentially
- * usefull.
- */
- INP_INFO_WLOCK(&V_tcbinfo);
- LIST_FOREACH(inpb, V_tcbinfo.ipi_listhead, inp_list) {
- if (inpb->inp_flags & INP_TIMEWAIT)
- continue;
- INP_LOCK(inpb);
- if ((tcpb = intotcpcb(inpb)) != NULL) {
- tcp_reass_flush(tcpb);
- tcp_clean_sackreport(tcpb);
- }
- INP_UNLOCK(inpb);
- }
- INP_INFO_WUNLOCK(&V_tcbinfo);
- CURVNET_RESTORE();
- }
- VNET_LIST_RUNLOCK_NOSLEEP();
- }
- /*
- * 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 struct inpcb *
- tcp_notify(struct inpcb *inp, int error)
- {
- struct tcpcb *tp;
- INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
- INP_LOCK_ASSERT(inp);
- if ((inp->inp_flags & INP_TIMEWAIT) ||
- (inp->inp_flags & INP_DROPPED))
- return (inp);
- tp = intotcpcb(inp);
- KASSERT(tp != NULL, ("tcp_notify: tp == NULL"));
- /*
- * 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->get_state() == TCPS_ESTABLISHED &&
- (error == EHOSTUNREACH || error == ENETUNREACH ||
- error == EHOSTDOWN)) {
- return (inp);
- } else if (tp->get_state() < TCPS_ESTABLISHED && tp->t_rxtshift > 3 &&
- tp->t_softerror) {
- tp = tcp_drop(tp, error);
- if (tp != NULL)
- return (inp);
- else
- return (NULL);
- } else {
- tp->t_softerror = error;
- return (inp);
- }
- #if 0
- wakeup( &so->so_timeo);
- sorwakeup(so);
- sowwakeup(so);
- #endif
- }
- #if 0
- static int
- tcp_pcblist(SYSCTL_HANDLER_ARGS)
- {
- int error, i, m, n, pcb_count;
- struct inpcb *inp, **inp_list;
- inp_gen_t gencnt;
- struct xinpgen xig;
- /*
- * The process of preparing the TCB list is too time-consuming and
- * resource-intensive to repeat twice on every request.
- */
- if (req->oldptr == NULL) {
- n = V_tcbinfo.ipi_count + syncache_pcbcount();
- n += imax(n / 8, 10);
- req->oldidx = 2 * (sizeof xig) + n * sizeof(struct xtcpcb);
- return (0);
- }
- if (req->newptr != NULL)
- return (EPERM);
- /*
- * OK, now we're committed to doing something.
- */
- INP_INFO_RLOCK(&V_tcbinfo);
- gencnt = V_tcbinfo.ipi_gencnt;
- n = V_tcbinfo.ipi_count;
- INP_INFO_RUNLOCK(&V_tcbinfo);
- m = syncache_pcbcount();
- error = sysctl_wire_old_buffer(req, 2 * (sizeof xig)
- + (n + m) * sizeof(struct xtcpcb));
- if (error != 0)
- return (error);
- xig.xig_len = sizeof xig;
- xig.xig_count = n + m;
- xig.xig_gen = gencnt;
- xig.xig_sogen = so_gencnt;
- error = SYSCTL_OUT(req, &xig, sizeof xig);
- if (error)
- return (error);
- error = syncache_pcblist(req, m, &pcb_count);
- if (error)
- return (error);
- inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
- if (inp_list == NULL)
- return (ENOMEM);
- INP_INFO_RLOCK(&V_tcbinfo);
- for (inp = LIST_FIRST(V_tcbinfo.ipi_listhead), i = 0;
- inp != NULL && i < n; inp = LIST_NEXT(inp, inp_list)) {
- INP_LOCK(inp);
- if (inp->inp_gencnt <= gencnt) {
- /*
- * XXX: This use of cr_cansee(), introduced with
- * TCP state changes, is not quite right, but for
- * now, better than nothing.
- */
- if (inp->inp_flags & INP_TIMEWAIT) {
- if (intotw(inp) != NULL)
- error = cr_cansee(req->td->td_ucred,
- intotw(inp)->tw_cred);
- else
- error = EINVAL; /* Skip this inp. */
- } else
- error = cr_canseeinpcb(req->td->td_ucred, inp);
- if (error == 0) {
- in_pcbref(inp);
- inp_list[i++] = inp;
- }
- }
- INP_UNLOCK(inp);
- }
- INP_INFO_RUNLOCK(&V_tcbinfo);
- n = i;
- error = 0;
- for (i = 0; i < n; i++) {
- inp = inp_list[i];
- INP_LOCK(inp);
- if (inp->inp_gencnt <= gencnt) {
- struct xtcpcb xt;
- void *inp_ppcb;
- bzero(&xt, sizeof(xt));
- xt.xt_len = sizeof xt;
- /* XXX should avoid extra copy */
- bcopy(inp, &xt.xt_inp, sizeof *inp);
- inp_ppcb = inp->inp_ppcb;
- if (inp_ppcb == NULL)
- bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
- else if (inp->inp_flags & INP_TIMEWAIT) {
- bzero((char *) &xt.xt_tp, sizeof xt.xt_tp);
- xt.xt_tp.t_state = TCPS_TIME_WAIT;
- } else {
- bcopy(inp_ppcb, &xt.xt_tp, sizeof xt.xt_tp);
- if (xt.xt_tp.t_timers)
- tcp_timer_to_xtimer(&xt.xt_tp, xt.xt_tp.t_timers, &xt.xt_timer);
- }
- if (inp->inp_socket != NULL)
- sotoxsocket(inp->inp_socket, &xt.xt_socket);
- else {
- bzero(&xt.xt_socket, sizeof xt.xt_socket);
- xt.xt_socket.xso_protocol = IPPROTO_TCP;
- }
- xt.xt_inp.inp_gencnt = inp->inp_gencnt;
- INP_UNLOCK(inp);
- error = SYSCTL_OUT(req, &xt, sizeof xt);
- } else
- INP_UNLOCK(inp);
- }
- INP_INFO_WLOCK(&V_tcbinfo);
- for (i = 0; i < n; i++) {
- inp = inp_list[i];
- INP_LOCK(inp);
- if (!in_pcbrele_locked(inp))
- INP_UNLOCK(inp);
- }
- INP_INFO_WUNLOCK(&V_tcbinfo);
- if (!error) {
- /*
- * Give the user an updated idea of our state.
- * If the generation differs from what we told
- * her before, she knows that something happened
- * while we were processing this request, and it
- * might be necessary to retry.
- */
- INP_INFO_RLOCK(&V_tcbinfo);
- xig.xig_gen = V_tcbinfo.ipi_gencnt;
- xig.xig_sogen = so_gencnt;
- xig.xig_count = V_tcbinfo.ipi_count + pcb_count;
- INP_INFO_RUNLOCK(&V_tcbinfo);
- error = SYSCTL_OUT(req, &xig, sizeof xig);
- }
- free(inp_list, M_TEMP);
- return (error);
- }
- SYSCTL_PROC(_net_inet_tcp, TCPCTL_PCBLIST, pcblist,
- CTLTYPE_OPAQUE | CTLFLAG_RD, NULL, 0,
- tcp_pcblist, "S,xtcpcb", "List of active TCP connections");
- #ifdef INET
- static int
- tcp_getcred(SYSCTL_HANDLER_ARGS)
- {
- struct xucred xuc;
- struct bsd_sockaddr_in addrs[2];
- struct inpcb *inp;
- int error;
- error = priv_check(req->td, PRIV_NETINET_GETCRED);
- if (error)
- return (error);
- error = SYSCTL_IN(req, addrs, sizeof(addrs));
- if (error)
- return (error);
- inp = in_pcblookup(&V_tcbinfo, addrs[1].sin_addr, addrs[1].sin_port,
- addrs[0].sin_addr, addrs[0].sin_port, INPLOOKUP_RLOCKPCB, NULL);
- if (inp != NULL) {
- if (inp->inp_socket == NULL)
- error = ENOENT;
- if (error == 0)
- error = cr_canseeinpcb(req->td->td_ucred, inp);
- if (error == 0)
- cru2x(inp->inp_cred, &xuc);
- INP_UNLOCK(inp);
- } else
- error = ENOENT;
- if (error == 0)
- error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
- return (error);
- }
- SYSCTL_PROC(_net_inet_tcp, OID_AUTO, getcred,
- CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
- tcp_getcred, "S,xucred", "Get the xucred of a TCP connection");
- #endif /* INET */
- #ifdef INET6
- static int
- tcp6_getcred(SYSCTL_HANDLER_ARGS)
- {
- struct xucred xuc;
- struct bsd_sockaddr_in6 addrs[2];
- struct inpcb *inp;
- int error;
- #ifdef INET
- int mapped = 0;
- #endif
- error = priv_check(req->td, PRIV_NETINET_GETCRED);
- if (error)
- return (error);
- error = SYSCTL_IN(req, addrs, sizeof(addrs));
- if (error)
- return (error);
- if ((error = sa6_embedscope(&addrs[0], V_ip6_use_defzone)) != 0 ||
- (error = sa6_embedscope(&addrs[1], V_ip6_use_defzone)) != 0) {
- return (error);
- }
- if (IN6_IS_ADDR_V4MAPPED(&addrs[0].sin6_addr)) {
- #ifdef INET
- if (IN6_IS_ADDR_V4MAPPED(&addrs[1].sin6_addr))
- mapped = 1;
- else
- #endif
- return (EINVAL);
- }
- #ifdef INET
- if (mapped == 1)
- inp = in_pcblookup(&V_tcbinfo,
- *(struct in_addr *)&addrs[1].sin6_addr.s6_addr[12],
- addrs[1].sin6_port,
- *(struct in_addr *)&addrs[0].sin6_addr.s6_addr[12],
- addrs[0].sin6_port, INPLOOKUP_RLOCKPCB, NULL);
- else
- #endif
- inp = in6_pcblookup(&V_tcbinfo,
- &addrs[1].sin6_addr, addrs[1].sin6_port,
- &addrs[0].sin6_addr, addrs[0].sin6_port,
- INPLOOKUP_RLOCKPCB, NULL);
- if (inp != NULL) {
- if (inp->inp_socket == NULL)
- error = ENOENT;
- if (error == 0)
- error = cr_canseeinpcb(req->td->td_ucred, inp);
- if (error == 0)
- cru2x(inp->inp_cred, &xuc);
- INP_UNLOCK(inp);
- } else
- error = ENOENT;
- if (error == 0)
- error = SYSCTL_OUT(req, &xuc, sizeof(struct xucred));
- return (error);
- }
- SYSCTL_PROC(_net_inet6_tcp6, OID_AUTO, getcred,
- CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_PRISON, 0, 0,
- tcp6_getcred, "S,xucred", "Get the xucred of a TCP6 connection");
- #endif /* INET6 */
- #endif
- #ifdef INET
- void
- tcp_ctlinput(int cmd, struct bsd_sockaddr *sa, void *vip)
- {
- struct ip *ip = (struct ip *)vip;
- struct tcphdr *th;
- struct in_addr faddr;
- struct inpcb *inp;
- struct tcpcb *tp;
- struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
- struct icmp *icp;
- struct in_conninfo inc;
- tcp_seq icmp_tcp_seq;
- int mtu;
- faddr = ((struct bsd_sockaddr_in *)sa)->sin_addr;
- if (sa->sa_family != AF_INET || faddr.s_addr == INADDR_ANY)
- return;
- if (cmd == PRC_MSGSIZE)
- notify = tcp_mtudisc_notify;
- else if (V_icmp_may_rst && (cmd == PRC_UNREACH_ADMIN_PROHIB ||
- cmd == PRC_UNREACH_PORT || cmd == PRC_TIMXCEED_INTRANS) && ip)
- notify = tcp_drop_syn_sent;
- /*
- * Redirects don't need to be handled up here.
- */
- else if (PRC_IS_REDIRECT(cmd))
- return;
- /*
- * Source quench is depreciated.
- */
- else if (cmd == PRC_QUENCH)
- return;
- /*
- * Hostdead is ugly because it goes linearly through all PCBs.
- * XXX: We never get this from ICMP, otherwise it makes an
- * excellent DoS attack on machines with many connections.
- */
- else if (cmd == PRC_HOSTDEAD)
- ip = NULL;
- else if ((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0)
- return;
- if (ip != NULL) {
- icp = (struct icmp *)((caddr_t)ip
- - offsetof(struct icmp, icmp_ip));
- th = (struct tcphdr *)((caddr_t)ip
- + (ip->ip_hl << 2));
- INP_INFO_WLOCK(&V_tcbinfo);
- inp = in_pcblookup(&V_tcbinfo, faddr, th->th_dport,
- ip->ip_src, th->th_sport, INPLOOKUP_LOCKPCB, NULL);
- if (inp != NULL) {
- if (!(inp->inp_flags & INP_TIMEWAIT) &&
- !(inp->inp_flags & INP_DROPPED) &&
- !(inp->inp_socket == NULL)) {
- icmp_tcp_seq = htonl(th->th_seq);
- tp = intotcpcb(inp);
- if (icmp_tcp_seq >= tp->snd_una &&
- icmp_tcp_seq < tp->snd_max) {
- if (cmd == PRC_MSGSIZE) {
- /*
- * MTU discovery:
- * If we got a needfrag set the MTU
- * in the route to the suggested new
- * value (if given) and then notify.
- */
- bzero(&inc, sizeof(inc));
- inc.inc_faddr = faddr;
- inc.inc_fibnum =
- inp->inp_inc.inc_fibnum;
- mtu = ntohs(icp->icmp_nextmtu);
- /*
- * If no alternative MTU was
- * proposed, try the next smaller
- * one. ip->ip_len has already
- * been swapped in icmp_input().
- */
- if (!mtu)
- mtu = ip_next_mtu(ip->ip_len,
- 1);
- if (mtu < V_tcp_minmss
- + sizeof(struct tcpiphdr))
- mtu = V_tcp_minmss
- + sizeof(struct tcpiphdr);
- /*
- * Only cache the MTU if it
- * is smaller than the interface
- * or route MTU. tcp_mtudisc()
- * will do right thing by itself.
- */
- if (mtu <= tcp_maxmtu(&inc, NULL))
- tcp_hc_updatemtu(&inc, mtu);
- tcp_mtudisc(inp, mtu);
- } else
- inp = (*notify)(inp,
- inetctlerrmap[cmd]);
- }
- }
- if (inp != NULL)
- INP_UNLOCK(inp);
- } else {
- bzero(&inc, sizeof(inc));
- inc.inc_fport = th->th_dport;
- inc.inc_lport = th->th_sport;
- inc.inc_faddr = faddr;
- inc.inc_laddr = ip->ip_src;
- syncache_unreach(&inc, th);
- }
- INP_INFO_WUNLOCK(&V_tcbinfo);
- } else
- in_pcbnotifyall(&V_tcbinfo, faddr, inetctlerrmap[cmd], notify);
- }
- #endif /* INET */
- #ifdef INET6
- void
- tcp6_ctlinput(int cmd, struct bsd_sockaddr *sa, void *d)
- {
- struct tcphdr th;
- struct inpcb *(*notify)(struct inpcb *, int) = tcp_notify;
- struct ip6_hdr *ip6;
- struct mbuf *m;
- struct ip6ctlparam *ip6cp = NULL;
- const struct bsd_sockaddr_in6 *sa6_src = NULL;
- int off;
- struct tcp_portonly {
- u_int16_t th_sport;
- u_int16_t th_dport;
- } *thp;
- if (sa->sa_family != AF_INET6 ||
- sa->sa_len != sizeof(struct bsd_sockaddr_in6))
- return;
- if (cmd == PRC_MSGSIZE)
- notify = tcp_mtudisc_notify;
- else if (!PRC_IS_REDIRECT(cmd) &&
- ((unsigned)cmd >= PRC_NCMDS || inet6ctlerrmap[cmd] == 0))
- return;
- /* Source quench is depreciated. */
- else if (cmd == PRC_QUENCH)
- return;
- /* if the parameter is from icmp6, decode it. */
- 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_dat.MH.MH_pkthdr.len < off + sizeof(*thp))
- return;
- bzero(&th, sizeof(th));
- m_copydata(m, off, sizeof(*thp), (caddr_t)&th);
- in6_pcbnotify(&V_tcbinfo, sa, th.th_dport,
- (struct bsd_sockaddr *)ip6cp->ip6c_src,
- th.th_sport, cmd, NULL, notify);
- bzero(&inc, sizeof(inc));
- inc.inc_fport = th.th_dport;
- inc.inc_lport = th.th_sport;
- inc.inc6_faddr = ((struct bsd_sockaddr_in6 *)sa)->sin6_addr;
- inc.inc6_laddr = ip6cp->ip6c_src->sin6_addr;
- inc.inc_flags |= INC_ISIPV6;
- INP_INFO_WLOCK(&V_tcbinfo);
- syncache_unreach(&inc, &th);
- INP_INFO_WUNLOCK(&V_tcbinfo);
- } else
- in6_pcbnotify(&V_tcbinfo, sa, 0, (const struct bsd_sockaddr *)sa6_src,
- 0, cmd, NULL, notify);
- }
- #endif /* INET6 */
- /*
- * 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, with only small modifications.
- *
- * Implementation details:
- *
- * Time is based off the system timer, and is corrected so that it
- * increases by one megabyte per second. This allows for proper
- * recycling on high speed LANs while still leaving over an hour
- * before rollover.
- *
- * As reading the *exact* system time is too expensive to be done
- * whenever setting up a TCP connection, we increment the time
- * offset in two ways. First, a small random positive increment
- * is added to isn_offset for each connection that is set up.
- * Second, the function tcp_isn_tick fires once per clock tick
- * and increments isn_offset as necessary so that sequence numbers
- * are incremented at approximately ISN_BYTES_PER_SECOND. The
- * random positive increments serve only to ensure that the same
- * exact sequence number is never sent out twice (as could otherwise
- * happen when a port is recycled in less than the system tick
- * interval.)
- *
- * net.inet.tcp.isn_reseed_interval controls the number of seconds
- * between seeding of isn_secret. This is normally set to zero,
- * as reseeding should not be necessary.
- *
- * Locking of the global variables isn_secret, isn_last_reseed, isn_offset,
- * isn_offset_old, and isn_ctx is performed using the TCP pcbinfo lock. In
- * general, this means holding an exclusive (write) lock.
- */
- #define ISN_BYTES_PER_SECOND 1048576
- #define ISN_STATIC_INCREMENT 4096
- #define ISN_RANDOM_INCREMENT (4096 - 1)
- static VNET_DEFINE(u_char, isn_secret[32]);
- static VNET_DEFINE(int, isn_last);
- static VNET_DEFINE(int, isn_last_reseed);
- static VNET_DEFINE(u_int32_t, isn_offset);
- static VNET_DEFINE(u_int32_t, isn_offset_old);
- #define V_isn_secret VNET(isn_secret)
- #define V_isn_last VNET(isn_last)
- #define V_isn_last_reseed VNET(isn_last_reseed)
- #define V_isn_offset VNET(isn_offset)
- #define V_isn_offset_old VNET(isn_offset_old)
- tcp_seq
- tcp_new_isn(struct tcpcb *tp)
- {
- MD5_CTX isn_ctx;
- u_int32_t md5_buffer[4];
- tcp_seq new_isn;
- u_int32_t projected_offset;
- INP_LOCK_ASSERT(tp->t_inpcb);
- ISN_LOCK();
- /* Seed if this is the first use, reseed if requested. */
- if ((V_isn_last_reseed == 0) || ((V_tcp_isn_reseed_interval > 0) &&
- (((u_int)V_isn_last_reseed + (u_int)V_tcp_isn_reseed_interval*hz)
- < (u_int)bsd_ticks))) {
- read_random(&V_isn_secret, sizeof(V_isn_secret));
- V_isn_last_reseed = bsd_ticks;
- }
- /* Compute the md5 hash and return the ISN. */
- MD5Init(&isn_ctx);
- MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_fport, sizeof(u_short));
- MD5Update(&isn_ctx, (u_char *) &tp->t_inpcb->inp_lport, sizeof(u_short));
- #ifdef INET6
- if ((tp->t_inpcb->inp_vflag & INP_IPV6) != 0) {
- 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));
- }
- MD5Update(&isn_ctx, (u_char *) &V_isn_secret, sizeof(V_isn_secret));
- MD5Final((u_char *) &md5_buffer, &isn_ctx);
- new_isn = (tcp_seq) md5_buffer[0];
- V_isn_offset += ISN_STATIC_INCREMENT +
- (arc4random() & ISN_RANDOM_INCREMENT);
- if (bsd_ticks != V_isn_last) {
- projected_offset = V_isn_offset_old +
- ISN_BYTES_PER_SECOND / hz * (bsd_ticks - V_isn_last);
- if (tcp_seq(projected_offset) > tcp_seq(V_isn_offset))
- V_isn_offset = projected_offset;
- V_isn_offset_old = V_isn_offset;
- V_isn_last = bsd_ticks;
- }
- new_isn += V_isn_offset;
- ISN_UNLOCK();
- return (new_isn);
- }
- /*
- * 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.
- */
- struct inpcb *
- tcp_drop_syn_sent(struct inpcb *inp, int errval)
- {
- struct tcpcb *tp;
- INP_INFO_WLOCK_ASSERT(&V_tcbinfo);
- INP_LOCK_ASSERT(inp);
- if ((inp->inp_flags & INP_TIMEWAIT) ||
- (inp->inp_flags & INP_DROPPED))
- return (inp);
- tp = intotcpcb(inp);
- if (tp->get_state() != TCPS_SYN_SENT)
- return (inp);
- tp = tcp_drop(tp, errval);
- if (tp != NULL)
- return (inp);
- else
- return (NULL);
- }
- /*
- * When `need fragmentation' ICMP is received, update our idea of the MSS
- * based on the new value. 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.
- */
- static struct inpcb *
- tcp_mtudisc_notify(struct inpcb *inp, int error)
- {
- return (tcp_mtudisc(inp, -1));
- }
- struct inpcb *
- tcp_mtudisc(struct inpcb *inp, int mtuoffer)
- {
- struct tcpcb *tp;
- struct socket *so;
- INP_LOCK_ASSERT(inp);
- if ((inp->inp_flags & INP_TIMEWAIT) ||
- (inp->inp_flags & INP_DROPPED))
- return (inp);
- tp = intotcpcb(inp);
- KASSERT(tp != NULL, ("tcp_mtudisc: tp == NULL"));
- tcp_mss_update(tp, -1, mtuoffer, NULL, NULL);
-
- so = inp->inp_socket;
- SOCK_LOCK(so);
- /* If the mss is larger than the socket buffer, decrease the mss. */
- if (so->so_snd.sb_hiwat < tp->t_maxseg)
- tp->t_maxseg = so->so_snd.sb_hiwat;
- SOCK_UNLOCK(so);
- TCPSTAT_INC(tcps_mturesent);
- tp->t_rtttime = 0;
- tp->snd_nxt = tp->snd_una;
- tcp_free_sackholes(tp);
- tp->snd_recover = tp->snd_max;
- if (tp->t_flags & TF_SACK_PERMIT)
- EXIT_FASTRECOVERY(tp->t_flags);
- tcp_output(tp);
- return (inp);
- }
- #ifdef INET
- /*
- * Look-up the routing entry to the peer of this inpcb. If no route
- * is found and it cannot be allocated, then return 0. This routine
- * is called by TCP routines that access the rmx structure and by
- * tcp_mss_update to get the peer/interface MTU.
- */
- u_long
- tcp_maxmtu(struct in_conninfo *inc, int *flags)
- {
- struct route sro;
- struct rtentry rte_one;
- struct bsd_sockaddr_in *dst;
- struct ifnet *ifp;
- u_long maxmtu = 0;
- KASSERT(inc != NULL, ("tcp_maxmtu with NULL in_conninfo pointer"));
- bzero(&sro, sizeof(sro));
- if (inc->inc_faddr.s_addr != INADDR_ANY) {
- dst = (struct bsd_sockaddr_in *)&sro.ro_dst;
- dst->sin_family = AF_INET;
- dst->sin_len = sizeof(*dst);
- dst->sin_addr = inc->inc_faddr;
- if (route_cache::lookup(dst, inc->inc_fibnum, &rte_one)) {
- sro.ro_rt = &rte_one;
- } else {
- sro.ro_rt = NULL;
- }
- }
- if (sro.ro_rt != NULL) {
- ifp = sro.ro_rt->rt_ifp;
- if (sro.ro_rt->rt_rmx.rmx_mtu == 0)
- maxmtu = ifp->if_mtu;
- else
- maxmtu = bsd_min(sro.ro_rt->rt_rmx.rmx_mtu, ifp->if_mtu);
- /* Report additional interface capabilities. */
- if (flags != NULL) {
- if (ifp->if_capenable & IFCAP_TSO4 &&
- ifp->if_hwassist & CSUM_TSO)
- *flags |= CSUM_TSO;
- }
- }
- return (maxmtu);
- }
- #endif /* INET */
- #ifdef INET6
- u_long
- tcp_maxmtu6(struct in_conninfo *inc, int *flags)
- {
- struct route_in6 sro6;
- struct ifnet *ifp;
- u_long maxmtu = 0;
- KASSERT(inc != NULL, ("tcp_maxmtu6 with NULL in_conninfo pointer"));
- bzero(&sro6, sizeof(sro6));
- if (!IN6_IS_ADDR_UNSPECIFIED(&inc->inc6_faddr)) {
- sro6.ro_dst.sin6_family = AF_INET6;
- sro6.ro_dst.sin6_len = sizeof(struct bsd_sockaddr_in6);
- sro6.ro_dst.sin6_addr = inc->inc6_faddr;
- in6_rtalloc_ign(&sro6, 0, inc->inc_fibnum);
- }
- if (sro6.ro_rt != NULL) {
- ifp = sro6.ro_rt->rt_ifp;
- if (sro6.ro_rt->rt_rmx.rmx_mtu == 0)
- maxmtu = IN6_LINKMTU(sro6.ro_rt->rt_ifp);
- else
- maxmtu = min(sro6.ro_rt->rt_rmx.rmx_mtu,
- IN6_LINKMTU(sro6.ro_rt->rt_ifp));
- /* Report additional interface capabilities. */
- if (flags != NULL) {
- if (ifp->if_capenable & IFCAP_TSO6 &&
- ifp->if_hwassist & CSUM_TSO)
- *flags |= CSUM_TSO;
- }
- RTFREE(sro6.ro_rt);
- }
- return (maxmtu);
- }
- #endif /* INET6 */
- #ifdef IPSEC
- /* compute ESP/AH header size for TCP, including outer IP header. */
- size_t
- ipsec_hdrsiz_tcp(struct tcpcb *tp)
- {
- struct inpcb *inp;
- struct mbuf *m;
- size_t hdrsiz;
- struct ip *ip;
- #ifdef INET6
- struct ip6_hdr *ip6;
- #endif
- struct tcphdr *th;
- if ((tp == NULL) || ((inp = tp->t_inpcb) == NULL))
- return (0);
- MGETHDR(m, M_DONTWAIT, MT_DATA);
- if (!m)
- return (0);
- #ifdef INET6
- if ((inp->inp_vflag & INP_IPV6) != 0) {
- ip6 = mtod(m, struct ip6_hdr *);
- th = (struct tcphdr *)(ip6 + 1);
- m->M_dat.MH.MH_pkthdr.len = m->m_hdr.mh_len =
- sizeof(struct ip6_hdr) + sizeof(struct tcphdr);
- tcpip_fillheaders(inp, ip6, th);
- hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
- } else
- #endif /* INET6 */
- {
- ip = mtod(m, struct ip *);
- th = (struct tcphdr *)(ip + 1);
- m->M_dat.MH.MH_pkthdr.len = m->m_hdr.mh_len = sizeof(struct tcpiphdr);
- tcpip_fillheaders(inp, ip, th);
- hdrsiz = ipsec_hdrsiz(m, IPSEC_DIR_OUTBOUND, inp);
- }
- m_free(m);
- return (hdrsiz);
- }
- #endif /* IPSEC */
- #ifdef TCP_SIGNATURE
- /*
- * Callback function invoked by m_apply() to digest TCP segment data
- * contained within an mbuf chain.
- */
- static int
- tcp_signature_apply(void *fstate, void *data, u_int len)
- {
- MD5Update(fstate, (u_char *)data, len);
- return (0);
- }
- /*
- * Compute TCP-MD5 hash of a TCP segment. (RFC2385)
- *
- * Parameters:
- * m pointer to head of mbuf chain
- * _unused
- * len length of TCP segment data, excluding options
- * optlen length of TCP segment options
- * buf pointer to storage for computed MD5 digest
- * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
- *
- * 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
- tcp_signature_compute(struct mbuf *m, int _unused, int len, int optlen,
- u_char *buf, u_int direction)
- {
- union bsd_sockaddr_union dst;
- #ifdef INET
- struct ippseudo ippseudo;
- #endif
- MD5_CTX ctx;
- int doff;
- struct ip *ip;
- #ifdef INET
- struct ipovly *ipovly;
- #endif
- struct secasvar *sav;
- struct tcphdr *th;
- #ifdef INET6
- struct ip6_hdr *ip6;
- struct in6_addr in6;
- char ip6buf[INET6_ADDRSTRLEN];
- uint32_t plen;
- uint16_t nhdr;
- #endif
- u_short savecsum;
- KASSERT(m != NULL, ("NULL mbuf chain"));
- KASSERT(buf != NULL, ("NULL signature pointer"));
- /* Extract the destination from the IP header in the mbuf. */
- bzero(&dst, sizeof(union bsd_sockaddr_union));
- ip = mtod(m, struct ip *);
- #ifdef INET6
- ip6 = NULL; /* Make the compiler happy. */
- #endif
- switch (ip->ip_v) {
- #ifdef INET
- case IPVERSION:
- dst.sa.sa_len = sizeof(struct bsd_sockaddr_in);
- dst.sa.sa_family = AF_INET;
- dst.sin.sin_addr = (direction == IPSEC_DIR_INBOUND) ?
- ip->ip_src : ip->ip_dst;
- break;
- #endif
- #ifdef INET6
- case (IPV6_VERSION >> 4):
- ip6 = mtod(m, struct ip6_hdr *);
- dst.sa.sa_len = sizeof(struct bsd_sockaddr_in6);
- dst.sa.sa_family = AF_INET6;
- dst.sin6.sin6_addr = (direction == IPSEC_DIR_INBOUND) ?
- ip6->ip6_src : ip6->ip6_dst;
- break;
- #endif
- default:
- return (EINVAL);
- /* NOTREACHED */
- break;
- }
- /* Look up an SADB entry which matches the address of the peer. */
- sav = KEY_ALLOCSA(&dst, IPPROTO_TCP, htonl(TCP_SIG_SPI));
- if (sav == NULL) {
- ipseclog((LOG_ERR, "%s: SADB lookup failed for %s\n", __func__,
- (ip->ip_v == IPVERSION) ? inet_ntoa(dst.sin.sin_addr) :
- #ifdef INET6
- (ip->ip_v == (IPV6_VERSION >> 4)) ?
- ip6_sprintf(ip6buf, &dst.sin6.sin6_addr) :
- #endif
- "(unsupported)"));
- return (EINVAL);
- }
- MD5Init(&ctx);
- /*
- * Step 1: Update MD5 hash with IP(v6) 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->ip_v) {
- #ifdef INET
- 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;
- #endif
- #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
- 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, tcp_signature_apply, &ctx);
- /*
- * Step 4: Update MD5 hash with shared secret.
- */
- MD5Update(&ctx, sav->key_auth->key_data, _KEYLEN(sav->key_auth));
- MD5Final(buf, &ctx);
- key_sa_recordxfer(sav, m);
- KEY_FREESAV(&sav);
- return (0);
- }
- /*
- * Verify the TCP-MD5 hash of a TCP segment. (RFC2385)
- *
- * Parameters:
- * m pointer to head of mbuf chain
- * len length of TCP segment data, excluding options
- * optlen length of TCP segment options
- * buf pointer to storage for computed MD5 digest
- * direction direction of flow (IPSEC_DIR_INBOUND or OUTBOUND)
- *
- * Return 1 if successful, otherwise return 0.
- */
- int
- tcp_signature_verify(struct mbuf *m, int off0, int tlen, int optlen,
- struct tcpopt *to, struct tcphdr *th, u_int tcpbflag)
- {
- char tmpdigest[TCP_SIGLEN];
- if (tcp_sig_checksigs == 0)
- return (1);
- if ((tcpbflag & TF_SIGNATURE) == 0) {
- if ((to->to_flags & TOF_SIGNATURE) != 0) {
- /*
- * If this socket is not expecting signature but
- * the segment contains signature just fail.
- */
- TCPSTAT_INC(tcps_sig_err_sigopt);
- TCPSTAT_INC(tcps_sig_rcvbadsig);
- return (0);
- }
- /* Signature is not expected, and not present in segment. */
- return (1);
- }
- /*
- * If this socket is expecting signature but the segment does not
- * contain any just fail.
- */
- if ((to->to_flags & TOF_SIGNATURE) == 0) {
- TCPSTAT_INC(tcps_sig_err_nosigopt);
- TCPSTAT_INC(tcps_sig_rcvbadsig);
- return (0);
- }
- if (tcp_signature_compute(m, off0, tlen, optlen, &tmpdigest[0],
- IPSEC_DIR_INBOUND) == -1) {
- TCPSTAT_INC(tcps_sig_err_buildsig);
- TCPSTAT_INC(tcps_sig_rcvbadsig);
- return (0);
- }
-
- if (bcmp(to->to_signature, &tmpdigest[0], TCP_SIGLEN) != 0) {
- TCPSTAT_INC(tcps_sig_rcvbadsig);
- return (0);
- }
- TCPSTAT_INC(tcps_sig_rcvgoodsig);
- return (1);
- }
- #endif /* TCP_SIGNATURE */
- #if 0
- static int
- sysctl_drop(SYSCTL_HANDLER_ARGS)
- {
- /* addrs[0] is a foreign socket, addrs[1] is a local one. */
- struct bsd_sockaddr_storage addrs[2];
- struct inpcb *inp;
- struct tcpcb *tp;
- struct tcptw *tw;
- struct bsd_sockaddr_in *fin, *lin;
- #ifdef INET6
- struct bsd_sockaddr_in6 *fin6, *lin6;
- #endif
- int error;
- inp = NULL;
- 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 bsd_sockaddr_in6 *)&addrs[0];
- lin6 = (struct bsd_sockaddr_in6 *)&addrs[1];
- if (fin6->sin6_len != sizeof(struct bsd_sockaddr_in6) ||
- lin6->sin6_len != sizeof(struct bsd_sockaddr_in6))
- return (EINVAL);
- if (IN6_IS_ADDR_V4MAPPED(&fin6->sin6_addr)) {
- if (!IN6_IS_ADDR_V4MAPPED(&lin6->sin6_addr))
- return (EINVAL);
- in6_sin6_2_sin_in_sock((struct bsd_sockaddr *)&addrs[0]);
- in6_sin6_2_sin_in_sock((struct bsd_sockaddr *)&addrs[1]);
- fin = (struct bsd_sockaddr_in *)&addrs[0];
- lin = (struct bsd_sockaddr_in *)&addrs[1];
- break;
- }
- error = sa6_embedscope(fin6, V_ip6_use_defzone);
- if (error)
- return (error);
- error = sa6_embedscope(lin6, V_ip6_use_defzone);
- if (error)
- return (error);
- break;
- #endif
- #ifdef INET
- case AF_INET:
- fin = (struct bsd_sockaddr_in *)&addrs[0];
- lin = (struct bsd_sockaddr_in *)&addrs[1];
- if (fin->sin_len != sizeof(struct bsd_sockaddr_in) ||
- lin->sin_len != sizeof(struct bsd_sockaddr_in))
- return (EINVAL);
- break;
- #endif
- default:
- return (EINVAL);
- }
- INP_INFO_WLOCK(&V_tcbinfo);
- switch (addrs[0].ss_family) {
- #ifdef INET6
- case AF_INET6:
- inp = in6_pcblookup(&V_tcbinfo, &fin6->sin6_addr,
- fin6->sin6_port, &lin6->sin6_addr, lin6->sin6_port,
- INPLOOKUP_WLOCKPCB, NULL);
- break;
- #endif
- #ifdef INET
- case AF_INET:
- inp = in_pcblookup(&V_tcbinfo, fin->sin_addr, fin->sin_port,
- lin->sin_addr, lin->sin_port, INPLOOKUP_WLOCKPCB, NULL);
- break;
- #endif
- }
- if (inp != NULL) {
- if (inp->inp_flags & INP_TIMEWAIT) {
- /*
- * XXXRW: There currently exists a state where an
- * inpcb is present, but its timewait state has been
- * discarded. For now, don't allow dropping of this
- * type of inpcb.
- */
- tw = intotw(inp);
- if (tw != NULL)
- tcp_twclose(tw, 0);
- else
- INP_UNLOCK(inp);
- } else if (!(inp->inp_flags & INP_DROPPED) &&
- !(inp->inp_socket->so_options & SO_ACCEPTCONN)) {
- tp = intotcpcb(inp);
- tp = tcp_drop(tp, ECONNABORTED);
- if (tp != NULL)
- INP_UNLOCK(inp);
- } else
- INP_UNLOCK(inp);
- } else
- error = ESRCH;
- INP_INFO_WUNLOCK(&V_tcbinfo);
- return (error);
- }
- SYSCTL_PROC(_net_inet_tcp, TCPCTL_DROP, drop,
- CTLTYPE_STRUCT|CTLFLAG_WR|CTLFLAG_SKIP, NULL,
- 0, sysctl_drop, "", "Drop TCP connection");
- #endif
- /*
- * Generate a standardized TCP log line for use throughout the
- * tcp subsystem. Memory allocation is done with M_NOWAIT to
- * allow use in the interrupt context.
- *
- * NB: The caller MUST free(s, M_TCPLOG) the returned string.
- * NB: The function may return NULL if memory allocation failed.
- *
- * Due to header inclusion and ordering limitations the struct ip
- * and ip6_hdr pointers have to be passed as void pointers.
- */
- char *
- tcp_log_vain(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
- const void *ip6hdr)
- {
- /* Is logging enabled? */
- if (tcp_log_in_vain == 0)
- return (NULL);
- return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
- }
- char *
- tcp_log_addrs(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
- const void *ip6hdr)
- {
- /* Is logging enabled? */
- if (tcp_log_debug == 0)
- return (NULL);
- return (tcp_log_addr(inc, th, ip4hdr, ip6hdr));
- }
- static char *
- tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th, void *ip4hdr,
- const void *ip6hdr)
- {
- char *s, *sp;
- size_t size;
- struct ip *ip;
- #ifdef INET6
- const struct ip6_hdr *ip6;
- ip6 = (const struct ip6_hdr *)ip6hdr;
- #endif /* INET6 */
- ip = (struct ip *)ip4hdr;
- /*
- * The log line looks like this:
- * "TCP: [1.2.3.4]:50332 to [1.2.3.4]:80 tcpflags 0x2<SYN>"
- */
- size = sizeof("TCP: []:12345 to []:12345 tcpflags 0x2<>") +
- sizeof(PRINT_TH_FLAGS) + 1 +
- #ifdef INET6
- 2 * INET6_ADDRSTRLEN;
- #else
- 2 * INET_ADDRSTRLEN;
- #endif /* INET6 */
- s = (char *)malloc(size);
- if (s == NULL)
- return (NULL);
- bzero(s, size);
- strcat(s, "TCP: [");
- sp = s + strlen(s);
- if (inc && ((inc->inc_flags & INC_ISIPV6) == 0)) {
- inet_ntoa_r(inc->inc_faddr, sp, s + size - sp);
- sp = s + strlen(s);
- sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
- sp = s + strlen(s);
- inet_ntoa_r(inc->inc_laddr, sp, s + size - sp);
- sp = s + strlen(s);
- sprintf(sp, "]:%i", ntohs(inc->inc_lport));
- #ifdef INET6
- } else if (inc) {
- ip6_sprintf(sp, &inc->inc6_faddr);
- sp = s + strlen(s);
- sprintf(sp, "]:%i to [", ntohs(inc->inc_fport));
- sp = s + strlen(s);
- ip6_sprintf(sp, &inc->inc6_laddr);
- sp = s + strlen(s);
- sprintf(sp, "]:%i", ntohs(inc->inc_lport));
- } else if (ip6 && th) {
- ip6_sprintf(sp, &ip6->ip6_src);
- sp = s + strlen(s);
- sprintf(sp, "]:%i to [", ntohs(th->th_sport));
- sp = s + strlen(s);
- ip6_sprintf(sp, &ip6->ip6_dst);
- sp = s + strlen(s);
- sprintf(sp, "]:%i", ntohs(th->th_dport));
- #endif /* INET6 */
- #ifdef INET
- } else if (ip && th) {
- inet_ntoa_r(ip->ip_src, sp, s + size - sp);
- sp = s + strlen(s);
- sprintf(sp, "]:%i to [", ntohs(th->th_sport));
- sp = s + strlen(s);
- inet_ntoa_r(ip->ip_dst, sp, s + size - sp);
- sp = s + strlen(s);
- sprintf(sp, "]:%i", ntohs(th->th_dport));
- #endif /* INET */
- } else {
- free(s);
- return (NULL);
- }
- sp = s + strlen(s);
- if (th)
- sprintf(sp, " tcpflags 0x%x", th->th_flags);
- if (*(s + size - 1) != '\0')
- panic("%s: string too long", __func__);
- return (s);
- }