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tcp_subr.c
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tcp_subr.c
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/*-
* 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>
__FBSDID("$FreeBSD$");
#include "opt_compat.h"
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_ipsec.h"
#include "opt_tcpdebug.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/eventhandler.h>
#include <sys/hhook.h>
#include <sys/kernel.h>
#include <sys/khelp.h>
#include <sys/sysctl.h>
#include <sys/jail.h>
#include <sys/malloc.h>
#include <sys/refcount.h>
#include <sys/mbuf.h>
#ifdef INET6
#include <sys/domain.h>
#endif
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/sdt.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/protosw.h>
#include <sys/random.h>
#include <vm/uma.h>
#include <net/route.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_fib.h>
#include <netinet/in_kdtrace.h>
#include <netinet/in_pcb.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#ifdef INET6
#include <netinet/ip6.h>
#include <netinet6/in6_fib.h>
#include <netinet6/in6_pcb.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#endif
#ifdef TCP_RFC7413
#include <netinet/tcp_fastopen.h>
#endif
#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/tcp_syncache.h>
#include <netinet/cc/cc.h>
#ifdef INET6
#include <netinet6/tcp6_var.h>
#endif
#include <netinet/tcpip.h>
#ifdef TCPPCAP
#include <netinet/tcp_pcap.h>
#endif
#ifdef TCPDEBUG
#include <netinet/tcp_debug.h>
#endif
#ifdef INET6
#include <netinet6/ip6protosw.h>
#endif
#ifdef TCP_OFFLOAD
#include <netinet/tcp_offload.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 <sys/md5.h>
#include <security/mac/mac_framework.h>
VNET_DEFINE(int, tcp_mssdflt) = TCP_MSS;
#ifdef INET6
VNET_DEFINE(int, tcp_v6mssdflt) = TCP6_MSS;
#endif
struct rwlock tcp_function_lock;
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_PROC(_net_inet_tcp, TCPCTL_MSSDFLT, mssdflt,
CTLFLAG_VNET | CTLTYPE_INT | CTLFLAG_RW, &VNET_NAME(tcp_mssdflt), 0,
&sysctl_net_inet_tcp_mss_check, "I",
"Default TCP Maximum Segment Size");
#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_PROC(_net_inet_tcp, TCPCTL_V6MSSDFLT, v6mssdflt,
CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, minmss, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(tcp_minmss), 0,
"Minimum TCP Maximum Segment Size");
VNET_DEFINE(int, tcp_do_rfc1323) = 1;
SYSCTL_INT(_net_inet_tcp, TCPCTL_DO_RFC1323, rfc1323, CTLFLAG_VNET | 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;
SYSCTL_INT(_net_inet_tcp, OID_AUTO, tcbhashsize, CTLFLAG_RDTUN | CTLFLAG_NOFETCH,
&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_UINT(_net_inet_tcp, OID_AUTO, pcbcount, CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, icmp_may_rst, CTLFLAG_VNET | 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_INT(_net_inet_tcp, OID_AUTO, isn_reseed_interval, CTLFLAG_VNET | CTLFLAG_RW,
&VNET_NAME(tcp_isn_reseed_interval), 0,
"Seconds between reseeding of ISN secret");
static int tcp_soreceive_stream;
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 void tcp_mtudisc(struct inpcb *, int);
static char * tcp_log_addr(struct in_conninfo *inc, struct tcphdr *th,
void *ip4hdr, const void *ip6hdr);
static struct tcp_function_block tcp_def_funcblk = {
"default",
tcp_output,
tcp_do_segment,
tcp_default_ctloutput,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
0,
0
};
int t_functions_inited = 0;
struct tcp_funchead t_functions;
static struct tcp_function_block *tcp_func_set_ptr = &tcp_def_funcblk;
static void
init_tcp_functions(void)
{
if (t_functions_inited == 0) {
TAILQ_INIT(&t_functions);
rw_init_flags(&tcp_function_lock, "tcp_func_lock" , 0);
t_functions_inited = 1;
}
}
static struct tcp_function_block *
find_tcp_functions_locked(struct tcp_function_set *fs)
{
struct tcp_function *f;
struct tcp_function_block *blk=NULL;
TAILQ_FOREACH(f, &t_functions, tf_next) {
if (strcmp(f->tf_fb->tfb_tcp_block_name, fs->function_set_name) == 0) {
blk = f->tf_fb;
break;
}
}
return(blk);
}
static struct tcp_function_block *
find_tcp_fb_locked(struct tcp_function_block *blk, struct tcp_function **s)
{
struct tcp_function_block *rblk=NULL;
struct tcp_function *f;
TAILQ_FOREACH(f, &t_functions, tf_next) {
if (f->tf_fb == blk) {
rblk = blk;
if (s) {
*s = f;
}
break;
}
}
return (rblk);
}
struct tcp_function_block *
find_and_ref_tcp_functions(struct tcp_function_set *fs)
{
struct tcp_function_block *blk;
rw_rlock(&tcp_function_lock);
blk = find_tcp_functions_locked(fs);
if (blk)
refcount_acquire(&blk->tfb_refcnt);
rw_runlock(&tcp_function_lock);
return(blk);
}
struct tcp_function_block *
find_and_ref_tcp_fb(struct tcp_function_block *blk)
{
struct tcp_function_block *rblk;
rw_rlock(&tcp_function_lock);
rblk = find_tcp_fb_locked(blk, NULL);
if (rblk)
refcount_acquire(&rblk->tfb_refcnt);
rw_runlock(&tcp_function_lock);
return(rblk);
}
static int
sysctl_net_inet_default_tcp_functions(SYSCTL_HANDLER_ARGS)
{
int error=ENOENT;
struct tcp_function_set fs;
struct tcp_function_block *blk;
memset(&fs, 0, sizeof(fs));
rw_rlock(&tcp_function_lock);
blk = find_tcp_fb_locked(tcp_func_set_ptr, NULL);
if (blk) {
/* Found him */
strcpy(fs.function_set_name, blk->tfb_tcp_block_name);
fs.pcbcnt = blk->tfb_refcnt;
}
rw_runlock(&tcp_function_lock);
error = sysctl_handle_string(oidp, fs.function_set_name,
sizeof(fs.function_set_name), req);
/* Check for error or no change */
if (error != 0 || req->newptr == NULL)
return(error);
rw_wlock(&tcp_function_lock);
blk = find_tcp_functions_locked(&fs);
if ((blk == NULL) ||
(blk->tfb_flags & TCP_FUNC_BEING_REMOVED)) {
error = ENOENT;
goto done;
}
tcp_func_set_ptr = blk;
done:
rw_wunlock(&tcp_function_lock);
return (error);
}
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_default,
CTLTYPE_STRING | CTLFLAG_RW,
NULL, 0, sysctl_net_inet_default_tcp_functions, "A",
"Set/get the default TCP functions");
static int
sysctl_net_inet_list_available(SYSCTL_HANDLER_ARGS)
{
int error, cnt, linesz;
struct tcp_function *f;
char *buffer, *cp;
size_t bufsz, outsz;
cnt = 0;
rw_rlock(&tcp_function_lock);
TAILQ_FOREACH(f, &t_functions, tf_next) {
cnt++;
}
rw_runlock(&tcp_function_lock);
bufsz = (cnt+2) * (TCP_FUNCTION_NAME_LEN_MAX + 12) + 1;
buffer = malloc(bufsz, M_TEMP, M_WAITOK);
error = 0;
cp = buffer;
linesz = snprintf(cp, bufsz, "\n%-32s%c %s\n", "Stack", 'D', "PCB count");
cp += linesz;
bufsz -= linesz;
outsz = linesz;
rw_rlock(&tcp_function_lock);
TAILQ_FOREACH(f, &t_functions, tf_next) {
linesz = snprintf(cp, bufsz, "%-32s%c %u\n",
f->tf_fb->tfb_tcp_block_name,
(f->tf_fb == tcp_func_set_ptr) ? '*' : ' ',
f->tf_fb->tfb_refcnt);
if (linesz >= bufsz) {
error = EOVERFLOW;
break;
}
cp += linesz;
bufsz -= linesz;
outsz += linesz;
}
rw_runlock(&tcp_function_lock);
if (error == 0)
error = sysctl_handle_string(oidp, buffer, outsz + 1, req);
free(buffer, M_TEMP);
return (error);
}
SYSCTL_PROC(_net_inet_tcp, OID_AUTO, functions_available,
CTLTYPE_STRING|CTLFLAG_RD,
NULL, 0, sysctl_net_inet_list_available, "A",
"list available TCP Function sets");
/*
* 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 0
#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;
struct osd osd;
};
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");
MALLOC_DEFINE(M_TCPFUNCTIONS, "tcpfunc", "TCP function set memory");
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)
{
uma_zone_set_max(V_tcbinfo.ipi_zone, maxsockets);
uma_zone_set_max(V_tcpcb_zone, maxsockets);
tcp_tw_zone_change();
}
static int
tcp_inpcb_init(void *mem, int size, int flags)
{
struct inpcb *inp = mem;
INP_LOCK_INIT(inp, "inp", "tcpinp");
return (0);
}
/*
* Take a value and get the next power of 2 that doesn't overflow.
* Used to size the tcp_inpcb hash buckets.
*/
static int
maketcp_hashsize(int size)
{
int hashsize;
/*
* auto tune.
* get the next power of 2 higher than maxsockets.
*/
hashsize = 1 << fls(size);
/* catch overflow, and just go one power of 2 smaller */
if (hashsize < size) {
hashsize = 1 << (fls(size) - 1);
}
return (hashsize);
}
int
register_tcp_functions(struct tcp_function_block *blk, int wait)
{
struct tcp_function_block *lblk;
struct tcp_function *n;
struct tcp_function_set fs;
if (t_functions_inited == 0) {
init_tcp_functions();
}
if ((blk->tfb_tcp_output == NULL) ||
(blk->tfb_tcp_do_segment == NULL) ||
(blk->tfb_tcp_ctloutput == NULL) ||
(strlen(blk->tfb_tcp_block_name) == 0)) {
/*
* These functions are required and you
* need a name.
*/
return (EINVAL);
}
if (blk->tfb_tcp_timer_stop_all ||
blk->tfb_tcp_timer_activate ||
blk->tfb_tcp_timer_active ||
blk->tfb_tcp_timer_stop) {
/*
* If you define one timer function you
* must have them all.
*/
if ((blk->tfb_tcp_timer_stop_all == NULL) ||
(blk->tfb_tcp_timer_activate == NULL) ||
(blk->tfb_tcp_timer_active == NULL) ||
(blk->tfb_tcp_timer_stop == NULL)) {
return (EINVAL);
}
}
n = malloc(sizeof(struct tcp_function), M_TCPFUNCTIONS, wait);
if (n == NULL) {
return (ENOMEM);
}
n->tf_fb = blk;
strcpy(fs.function_set_name, blk->tfb_tcp_block_name);
rw_wlock(&tcp_function_lock);
lblk = find_tcp_functions_locked(&fs);
if (lblk) {
/* Duplicate name space not allowed */
rw_wunlock(&tcp_function_lock);
free(n, M_TCPFUNCTIONS);
return (EALREADY);
}
refcount_init(&blk->tfb_refcnt, 0);
blk->tfb_flags = 0;
TAILQ_INSERT_TAIL(&t_functions, n, tf_next);
rw_wunlock(&tcp_function_lock);
return(0);
}
int
deregister_tcp_functions(struct tcp_function_block *blk)
{
struct tcp_function_block *lblk;
struct tcp_function *f;
int error=ENOENT;
if (strcmp(blk->tfb_tcp_block_name, "default") == 0) {
/* You can't un-register the default */
return (EPERM);
}
rw_wlock(&tcp_function_lock);
if (blk == tcp_func_set_ptr) {
/* You can't free the current default */
rw_wunlock(&tcp_function_lock);
return (EBUSY);
}
if (blk->tfb_refcnt) {
/* Still tcb attached, mark it. */
blk->tfb_flags |= TCP_FUNC_BEING_REMOVED;
rw_wunlock(&tcp_function_lock);
return (EBUSY);
}
lblk = find_tcp_fb_locked(blk, &f);
if (lblk) {
/* Found */
TAILQ_REMOVE(&t_functions, f, tf_next);
f->tf_fb = NULL;
free(f, M_TCPFUNCTIONS);
error = 0;
}
rw_wunlock(&tcp_function_lock);
return (error);
}
void
tcp_init(void)
{
const char *tcbhash_tuneable;
int hashsize;
tcbhash_tuneable = "net.inet.tcp.tcbhashsize";
if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN,
&V_tcp_hhh[HHOOK_TCP_EST_IN], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
printf("%s: WARNING: unable to register helper hook\n", __func__);
if (hhook_head_register(HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT,
&V_tcp_hhh[HHOOK_TCP_EST_OUT], HHOOK_NOWAIT|HHOOK_HEADISINVNET) != 0)
printf("%s: WARNING: unable to register helper hook\n", __func__);
hashsize = TCBHASHSIZE;
TUNABLE_INT_FETCH(tcbhash_tuneable, &hashsize);
if (hashsize == 0) {
/*
* Auto tune the hash size based on maxsockets.
* A perfect hash would have a 1:1 mapping
* (hashsize = maxsockets) however it's been
* suggested that O(2) average is better.
*/
hashsize = maketcp_hashsize(maxsockets / 4);
/*
* Our historical default is 512,
* do not autotune lower than this.
*/
if (hashsize < 512)
hashsize = 512;
if (bootverbose && IS_DEFAULT_VNET(curvnet))
printf("%s: %s auto tuned to %d\n", __func__,
tcbhash_tuneable, hashsize);
}
/*
* We require a hashsize to be a power of two.
* Previously if it was not a power of two we would just reset it
* back to 512, which could be a nasty surprise if you did not notice
* the error message.
* Instead what we do is clip it to the closest power of two lower
* than the specified hash value.
*/
if (!powerof2(hashsize)) {
int oldhashsize = hashsize;
hashsize = maketcp_hashsize(hashsize);
/* prevent absurdly low value */
if (hashsize < 16)
hashsize = 16;
printf("%s: WARNING: TCB hash size not a power of 2, "
"clipped from %d to %d.\n", __func__, oldhashsize,
hashsize);
}
in_pcbinfo_init(&V_tcbinfo, "tcp", &V_tcb, hashsize, hashsize,
"tcp_inpcb", tcp_inpcb_init, NULL, 0, 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, 0);
uma_zone_set_max(V_tcpcb_zone, maxsockets);
uma_zone_set_warning(V_tcpcb_zone, "kern.ipc.maxsockets limit reached");
tcp_tw_init();
syncache_init();
tcp_hc_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, 0);
/* Skip initialization of globals for non-default instances. */
if (!IS_DEFAULT_VNET(curvnet))
return;
tcp_reass_global_init();
/* XXX virtualize those bellow? */
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)
tcp_rexmit_min = 1;
tcp_persmin = TCPTV_PERSMIN;
tcp_persmax = TCPTV_PERSMAX;
tcp_rexmit_slop = TCPTV_CPU_VAR;
tcp_finwait2_timeout = TCPTV_FINWAIT2_TIMEOUT;
tcp_tcbhashsize = hashsize;
/* Setup the tcp function block list */
init_tcp_functions();
register_tcp_functions(&tcp_def_funcblk, M_WAITOK);
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();
EVENTHANDLER_REGISTER(shutdown_pre_sync, tcp_fini, NULL,
SHUTDOWN_PRI_DEFAULT);
EVENTHANDLER_REGISTER(maxsockets_change, tcp_zone_change, NULL,
EVENTHANDLER_PRI_ANY);
#ifdef TCPPCAP
tcp_pcap_init();
#endif
#ifdef TCP_RFC7413
tcp_fastopen_init();
#endif
}
#ifdef VIMAGE
static void
tcp_destroy(void *unused __unused)
{
int error, n;
/*
* All our processes are gone, all our sockets should be cleaned
* up, which means, we should be past the tcp_discardcb() calls.
* Sleep to let all tcpcb timers really disappear and cleanup.
*/
for (;;) {
INP_LIST_RLOCK(&V_tcbinfo);
n = V_tcbinfo.ipi_count;
INP_LIST_RUNLOCK(&V_tcbinfo);
if (n == 0)
break;
pause("tcpdes", hz / 10);
}
tcp_hc_destroy();
syncache_destroy();
tcp_tw_destroy();
in_pcbinfo_destroy(&V_tcbinfo);
/* tcp_discardcb() clears the sack_holes up. */
uma_zdestroy(V_sack_hole_zone);
uma_zdestroy(V_tcpcb_zone);
#ifdef TCP_RFC7413
/*
* Cannot free the zone until all tcpcbs are released as we attach
* the allocations to them.
*/
tcp_fastopen_destroy();
#endif
error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_IN]);
if (error != 0) {
printf("%s: WARNING: unable to deregister helper hook "
"type=%d, id=%d: error %d returned\n", __func__,
HHOOK_TYPE_TCP, HHOOK_TCP_EST_IN, error);
}
error = hhook_head_deregister(V_tcp_hhh[HHOOK_TCP_EST_OUT]);
if (error != 0) {
printf("%s: WARNING: unable to deregister helper hook "
"type=%d, id=%d: error %d returned\n", __func__,
HHOOK_TYPE_TCP, HHOOK_TCP_EST_OUT, error);
}
}
VNET_SYSUNINIT(tcp, SI_SUB_PROTO_DOMAIN, SI_ORDER_FOURTH, tcp_destroy, NULL);
#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_WLOCK_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 = 0;
th->th_ack = 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 = malloc(sizeof(*t), M_TEMP, M_NOWAIT);
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 th 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 th,
* 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 th 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)
{
struct tcpopt to;
struct inpcb *inp;
struct ip *ip;
struct mbuf *optm;
struct tcphdr *nth;
u_char *optp;
#ifdef INET6
struct ip6_hdr *ip6;
int isipv6;
#endif /* INET6 */
int optlen, tlen, win;
bool incl_opts;
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 = ipgen;
if (tp != NULL) {
inp = tp->t_inpcb;
KASSERT(inp != NULL, ("tcp control block w/o inpcb"));
INP_WLOCK_ASSERT(inp);
} else
inp = NULL;
incl_opts = false;
win = 0;
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 ((tp->t_flags & TF_NOOPT) == 0)
incl_opts = true;
}
if (m == NULL) {
m = m_gethdr(M_NOWAIT, MT_DATA);
if (m == NULL)
return;
m->m_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 if (!M_WRITABLE(m)) {
struct mbuf *n;
/* Can't reuse 'm', allocate a new mbuf. */
n = m_gethdr(M_NOWAIT, MT_DATA);
if (n == NULL) {
m_freem(m);
return;
}
if (!m_dup_pkthdr(n, m, M_NOWAIT)) {
m_freem(m);
m_freem(n);
return;
}
n->m_data += max_linkhdr;
/* m_len is set later */
#define xchg(a,b,type) { type t; t=a; a=b; b=t; }
#ifdef INET6
if (isipv6) {
bcopy((caddr_t)ip6, mtod(n, caddr_t),
sizeof(struct ip6_hdr));
ip6 = mtod(n, struct ip6_hdr *);
xchg(ip6->ip6_dst, ip6->ip6_src, struct in6_addr);
nth = (struct tcphdr *)(ip6 + 1);
} else
#endif /* INET6 */
{
bcopy((caddr_t)ip, mtod(n, caddr_t), sizeof(struct ip));
ip = mtod(n, struct ip *);
xchg(ip->ip_dst.s_addr, ip->ip_src.s_addr, uint32_t);
nth = (struct tcphdr *)(ip + 1);
}
bcopy((caddr_t)th, (caddr_t)nth, sizeof(struct tcphdr));
xchg(nth->th_dport, nth->th_sport, uint16_t);
th = nth;
m_freem(m);
m = n;
} else {
/*
* reuse the mbuf.
* XXX MRT We inherit the FIB, which is lucky.
*/
m_freem(m->m_next);
m->m_next = NULL;
m->m_data = (caddr_t)ipgen;
/* m_len is set later */
#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) {
/*