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Diffstat (limited to '')
| -rw-r--r-- | c/src/lib/libnetworking/netinet/tcp_subr.c | 634 |
1 files changed, 0 insertions, 634 deletions
diff --git a/c/src/lib/libnetworking/netinet/tcp_subr.c b/c/src/lib/libnetworking/netinet/tcp_subr.c deleted file mode 100644 index a9cde3fdf0..0000000000 --- a/c/src/lib/libnetworking/netinet/tcp_subr.c +++ /dev/null @@ -1,634 +0,0 @@ -/* - * 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. All advertising materials mentioning features or use of this software - * must display the following acknowledgement: - * This product includes software developed by the University of - * California, Berkeley and its contributors. - * 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 - * $Id$ - */ - -#include "opt_tcpdebug.h" - -#include <sys/param.h> -#include <sys/queue.h> -#include <sys/proc.h> -#include <sys/systm.h> -#include <sys/kernel.h> -#include <sys/sysctl.h> -#include <sys/malloc.h> -#include <sys/mbuf.h> -#include <sys/socket.h> -#include <sys/socketvar.h> -#include <sys/protosw.h> -#include <sys/errno.h> - -#include <net/route.h> -#include <net/if.h> - -#define _IP_VHL -#include <netinet/in.h> -#include <netinet/in_systm.h> -#include <netinet/ip.h> -#include <netinet/in_pcb.h> -#include <netinet/in_var.h> -#include <netinet/ip_var.h> -#include <netinet/ip_icmp.h> -#include <netinet/tcp.h> -#include <netinet/tcp_fsm.h> -#include <netinet/tcp_seq.h> -#include <netinet/tcp_timer.h> -#include <netinet/tcp_var.h> -#include <netinet/tcpip.h> -#ifdef TCPDEBUG -#include <netinet/tcp_debug.h> -#endif - -int tcp_mssdflt = TCP_MSS; -SYSCTL_INT(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt, - CTLFLAG_RW, &tcp_mssdflt , 0, ""); - -static int tcp_do_rfc1323 = 1; -static int tcp_do_rfc1644 = 1; -#if !defined(__rtems__) -static int tcp_rttdflt = TCPTV_SRTTDFLT / PR_SLOWHZ; -SYSCTL_INT(_net_inet_tcp, TCPCTL_RTTDFLT, rttdflt, - CTLFLAG_RW, &tcp_rttdflt , 0, ""); - -SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, - CTLFLAG_RW, &tcp_do_rfc1323 , 0, ""); - -SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1644, rfc1644, - CTLFLAG_RW, &tcp_do_rfc1644 , 0, ""); -#endif - -static void tcp_cleartaocache(void); -static void tcp_notify __P((struct inpcb *, int)); - -/* - * Target size of TCP PCB hash table. Will be rounded down to a prime - * number. - */ -#ifndef TCBHASHSIZE -#define TCBHASHSIZE 128 -#endif - -/* - * Tcp initialization - */ -void -tcp_init() -{ - - tcp_iss = random(); /* wrong, but better than a constant */ - tcp_ccgen = 1; - tcp_cleartaocache(); - LIST_INIT(&tcb); - tcbinfo.listhead = &tcb; - tcbinfo.hashbase = hashinit(TCBHASHSIZE, M_PCB, &tcbinfo.hashmask); - if (max_protohdr < sizeof(struct tcpiphdr)) - max_protohdr = sizeof(struct tcpiphdr); - if (max_linkhdr + sizeof(struct tcpiphdr) > MHLEN) - panic("tcp_init"); -} - -/* - * Create template to be used to send tcp packets on a connection. - * Call after host entry created, allocates an mbuf and fills - * in a skeletal tcp/ip header, minimizing the amount of work - * necessary when the connection is used. - */ -struct tcpiphdr * -tcp_template(tp) - struct tcpcb *tp; -{ - register struct inpcb *inp = tp->t_inpcb; - register struct mbuf *m; - register struct tcpiphdr *n; - - if ((n = tp->t_template) == 0) { - m = m_get(M_DONTWAIT, MT_HEADER); - if (m == NULL) - return (0); - m->m_len = sizeof (struct tcpiphdr); - n = mtod(m, struct tcpiphdr *); - } - n->ti_next = n->ti_prev = 0; - n->ti_x1 = 0; - n->ti_pr = IPPROTO_TCP; - n->ti_len = htons(sizeof (struct tcpiphdr) - sizeof (struct ip)); - n->ti_src = inp->inp_laddr; - n->ti_dst = inp->inp_faddr; - n->ti_sport = inp->inp_lport; - n->ti_dport = inp->inp_fport; - n->ti_seq = 0; - n->ti_ack = 0; - n->ti_x2 = 0; - n->ti_off = 5; - n->ti_flags = 0; - n->ti_win = 0; - n->ti_sum = 0; - n->ti_urp = 0; - return (n); -} - -/* - * Send a single message to the TCP at address specified by - * the given TCP/IP header. If m == 0, 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 tp->t_template. 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(tp, ti, m, ack, seq, flags) - struct tcpcb *tp; - register struct tcpiphdr *ti; - register struct mbuf *m; - tcp_seq ack, seq; - int flags; -{ - register int tlen; - int win = 0; - struct route *ro = 0; - struct route sro; - - if (tp) { - win = sbspace(&tp->t_inpcb->inp_socket->so_rcv); - ro = &tp->t_inpcb->inp_route; - } else { - ro = &sro; - bzero(ro, sizeof *ro); - } - if (m == 0) { - m = m_gethdr(M_DONTWAIT, MT_HEADER); - if (m == NULL) - return; -#ifdef TCP_COMPAT_42 - tlen = 1; -#else - tlen = 0; -#endif - m->m_data += max_linkhdr; - *mtod(m, struct tcpiphdr *) = *ti; - ti = mtod(m, struct tcpiphdr *); - flags = TH_ACK; - } else { - m_freem(m->m_next); - m->m_next = 0; - m->m_data = (caddr_t)ti; - m->m_len = sizeof (struct tcpiphdr); - tlen = 0; -#define xchg(a,b,type) { type t; t=a; a=b; b=t; } - xchg(ti->ti_dst.s_addr, ti->ti_src.s_addr, u_long); - xchg(ti->ti_dport, ti->ti_sport, u_short); -#undef xchg - } - ti->ti_len = htons((u_short)(sizeof (struct tcphdr) + tlen)); - tlen += sizeof (struct tcpiphdr); - m->m_len = tlen; - m->m_pkthdr.len = tlen; - m->m_pkthdr.rcvif = (struct ifnet *) 0; - ti->ti_next = ti->ti_prev = 0; - ti->ti_x1 = 0; - ti->ti_seq = htonl(seq); - ti->ti_ack = htonl(ack); - ti->ti_x2 = 0; - ti->ti_off = sizeof (struct tcphdr) >> 2; - ti->ti_flags = flags; - if (tp) - ti->ti_win = htons((u_short) (win >> tp->rcv_scale)); - else - ti->ti_win = htons((u_short)win); - ti->ti_urp = 0; - ti->ti_sum = 0; - ti->ti_sum = in_cksum(m, tlen); - ((struct ip *)ti)->ip_len = tlen; - ((struct ip *)ti)->ip_ttl = ip_defttl; -#ifdef TCPDEBUG - if (tp == NULL || (tp->t_inpcb->inp_socket->so_options & SO_DEBUG)) - tcp_trace(TA_OUTPUT, 0, tp, ti, 0); -#endif - (void) ip_output(m, NULL, ro, 0, NULL); - if (ro == &sro && ro->ro_rt) { - RTFREE(ro->ro_rt); - } -} - -/* - * Create a new TCP control block, making an - * empty reassembly queue and hooking it to the argument - * protocol control block. - */ -struct tcpcb * -tcp_newtcpcb(inp) - struct inpcb *inp; -{ - register struct tcpcb *tp; - - tp = malloc(sizeof(*tp), M_PCB, M_NOWAIT); - if (tp == NULL) - return ((struct tcpcb *)0); - bzero((char *) tp, sizeof(struct tcpcb)); - tp->seg_next = tp->seg_prev = (struct tcpiphdr *)tp; - tp->t_maxseg = tp->t_maxopd = tcp_mssdflt; - - if (tcp_do_rfc1323) - tp->t_flags = (TF_REQ_SCALE|TF_REQ_TSTMP); - if (tcp_do_rfc1644) - tp->t_flags |= TF_REQ_CC; - tp->t_inpcb = inp; - /* - * 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 = TCPTV_MIN; - tp->t_rxtcur = TCPTV_RTOBASE; - tp->snd_cwnd = TCP_MAXWIN << TCP_MAX_WINSHIFT; - tp->snd_ssthresh = TCP_MAXWIN << TCP_MAX_WINSHIFT; - inp->inp_ip_ttl = ip_defttl; - inp->inp_ppcb = (caddr_t)tp; - return (tp); -} - -/* - * Drop a TCP connection, reporting - * the specified error. If connection is synchronized, - * then send a RST to peer. - */ -struct tcpcb * -tcp_drop(tp, errnum) - register struct tcpcb *tp; - int errnum; -{ - struct socket *so = tp->t_inpcb->inp_socket; - - if (TCPS_HAVERCVDSYN(tp->t_state)) { - tp->t_state = TCPS_CLOSED; - (void) tcp_output(tp); - tcpstat.tcps_drops++; - } else - tcpstat.tcps_conndrops++; - if (errnum == ETIMEDOUT && tp->t_softerror) - errnum = tp->t_softerror; - so->so_error = errnum; - return (tcp_close(tp)); -} - -/* - * Close a TCP control block: - * discard all space held by the tcp - * discard internet protocol block - * wake up any sleepers - */ -struct tcpcb * -tcp_close(tp) - register struct tcpcb *tp; -{ - register struct tcpiphdr *t; - struct inpcb *inp = tp->t_inpcb; - struct socket *so = inp->inp_socket; - register struct mbuf *m; - register struct rtentry *rt; - - /* - * 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 && - (rt = inp->inp_route.ro_rt) && - ((struct sockaddr_in *)rt_key(rt))->sin_addr.s_addr != INADDR_ANY) { - register u_long i = 0; - - if ((rt->rt_rmx.rmx_locks & RTV_RTT) == 0) { - i = tp->t_srtt * - (RTM_RTTUNIT / (PR_SLOWHZ * 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) == 0) { - i = tp->t_rttvar * - (RTM_RTTUNIT / (PR_SLOWHZ * 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++; - } - /* - * 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. - */ - if (((rt->rt_rmx.rmx_locks & RTV_SSTHRESH) == 0 && - ((i = tp->snd_ssthresh) != 0) && rt->rt_rmx.rmx_ssthresh) || - i < (rt->rt_rmx.rmx_sendpipe / 2)) { - /* - * 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 *= (u_long)(tp->t_maxseg + 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++; - } - } - /* free the reassembly queue, if any */ - t = tp->seg_next; - while (t != (struct tcpiphdr *)tp) { - t = (struct tcpiphdr *)t->ti_next; - m = REASS_MBUF((struct tcpiphdr *)t->ti_prev); - remque(t->ti_prev); - m_freem(m); - } - if (tp->t_template) - (void) m_free(dtom(tp->t_template)); - free(tp, M_PCB); - inp->inp_ppcb = 0; - soisdisconnected(so); - in_pcbdetach(inp); - tcpstat.tcps_closed++; - return ((struct tcpcb *)0); -} - -void -tcp_drain() -{ - -} - -/* - * 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). - */ -static void -tcp_notify(inp, error) - struct inpcb *inp; - int error; -{ - register struct tcpcb *tp = (struct tcpcb *)inp->inp_ppcb; - register struct socket *so = inp->inp_socket; - - /* - * 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) - so->so_error = error; - else - tp->t_softerror = error; - soconnwakeup (so); - sorwakeup(so); - sowwakeup(so); -} - -void -tcp_ctlinput(cmd, sa, vip) - int cmd; - struct sockaddr *sa; - void *vip; -{ - register struct ip *ip = vip; - register struct tcphdr *th; - void (*notify) __P((struct inpcb *, int)) = tcp_notify; - - if (cmd == PRC_QUENCH) - notify = tcp_quench; -#if 1 - else if (cmd == PRC_MSGSIZE) - notify = tcp_mtudisc; -#endif - else if (!PRC_IS_REDIRECT(cmd) && - ((unsigned)cmd > PRC_NCMDS || inetctlerrmap[cmd] == 0)) - return; - if (ip) { - th = (struct tcphdr *)((caddr_t)ip - + (IP_VHL_HL(ip->ip_vhl) << 2)); - in_pcbnotify(&tcb, sa, th->th_dport, ip->ip_src, th->th_sport, - cmd, notify); - } else - in_pcbnotify(&tcb, sa, 0, zeroin_addr, 0, cmd, notify); -} - -/* - * When a source quench is received, close congestion window - * to one segment. We will gradually open it again as we proceed. - */ -void -tcp_quench(inp, errnum) - struct inpcb *inp; - int errnum; -{ - struct tcpcb *tp = intotcpcb(inp); - - if (tp) - tp->snd_cwnd = tp->t_maxseg; -} - -#if 1 -/* - * When `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(inp, errnum) - struct inpcb *inp; - int errnum; -{ - struct tcpcb *tp = intotcpcb(inp); - struct rtentry *rt; - struct rmxp_tao *taop; - struct socket *so = inp->inp_socket; - int offered; - int mss; - - if (tp) { - rt = tcp_rtlookup(inp); - if (!rt || !rt->rt_rmx.rmx_mtu) { - tp->t_maxopd = tp->t_maxseg = tcp_mssdflt; - return; - } - taop = rmx_taop(rt->rt_rmx); - offered = taop->tao_mssopt; - mss = rt->rt_rmx.rmx_mtu - sizeof(struct tcpiphdr); - if (offered) - mss = min(mss, offered); - /* - * XXX - The above 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 (tp->t_maxopd <= mss) - return; - tp->t_maxopd = mss; - - if ((tp->t_flags & (TF_REQ_TSTMP|TF_NOOPT)) == TF_REQ_TSTMP && - (tp->t_flags & TF_RCVD_TSTMP) == TF_RCVD_TSTMP) - mss -= TCPOLEN_TSTAMP_APPA; - if ((tp->t_flags & (TF_REQ_CC|TF_NOOPT)) == TF_REQ_CC && - (tp->t_flags & TF_RCVD_CC) == TF_RCVD_CC) - mss -= TCPOLEN_CC_APPA; -#if (MCLBYTES & (MCLBYTES - 1)) == 0 - if (mss > MCLBYTES) - mss &= ~(MCLBYTES-1); -#else - if (mss > MCLBYTES) - mss = mss / MCLBYTES * MCLBYTES; -#endif - if (so->so_snd.sb_hiwat < mss) - mss = so->so_snd.sb_hiwat; - - tp->t_maxseg = mss; - - tcpstat.tcps_mturesent++; - tp->t_rtt = 0; - tp->snd_nxt = tp->snd_una; - tcp_output(tp); - } -} -#endif - -/* - * 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(inp) - struct inpcb *inp; -{ - struct route *ro; - struct rtentry *rt; - - ro = &inp->inp_route; - rt = ro->ro_rt; - if (rt == NULL || !(rt->rt_flags & RTF_UP)) { - /* No route yet, so try to acquire one */ - if (inp->inp_faddr.s_addr != INADDR_ANY) { - ro->ro_dst.sa_family = AF_INET; - ro->ro_dst.sa_len = sizeof(ro->ro_dst); - ((struct sockaddr_in *) &ro->ro_dst)->sin_addr = - inp->inp_faddr; - rtalloc(ro); - rt = ro->ro_rt; - } - } - return rt; -} - -/* - * Return a pointer to the cached information about the remote host. - * The cached information is stored in the protocol specific part of - * the route metrics. - */ -struct rmxp_tao * -tcp_gettaocache(inp) - struct inpcb *inp; -{ - struct rtentry *rt = tcp_rtlookup(inp); - - /* Make sure this is a host route and is up. */ - if (rt == NULL || - (rt->rt_flags & (RTF_UP|RTF_HOST)) != (RTF_UP|RTF_HOST)) - return NULL; - - return rmx_taop(rt->rt_rmx); -} - -/* - * Clear all the TAO cache entries, called from tcp_init. - * - * XXX - * This routine is just an empty one, because we assume that the routing - * routing tables are initialized at the same time when TCP, so there is - * nothing in the cache left over. - */ -static void -tcp_cleartaocache(void) -{ } |