freebsd-dev/sys/netinet/udp_usrreq.c
Brian Feldman 7a2aab80b0 This is the much-awaited cleaned up version of IPFW [ug]id support.
All relevant changes have been made (including ipfw.8).
1999-06-19 18:43:33 +00:00

706 lines
18 KiB
C

/*
* 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.
*
* @(#)udp_usrreq.c 8.6 (Berkeley) 5/23/95
* $Id: udp_usrreq.c,v 1.51 1999/05/03 23:57:32 billf Exp $
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/protosw.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <vm/vm_zone.h>
#include <net/if.h>
#include <net/route.h>
#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/icmp_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
/*
* UDP protocol implementation.
* Per RFC 768, August, 1980.
*/
#ifndef COMPAT_42
static int udpcksum = 1;
#else
static int udpcksum = 0; /* XXX */
#endif
SYSCTL_INT(_net_inet_udp, UDPCTL_CHECKSUM, checksum, CTLFLAG_RW,
&udpcksum, 0, "");
static int log_in_vain = 0;
SYSCTL_INT(_net_inet_udp, OID_AUTO, log_in_vain, CTLFLAG_RW,
&log_in_vain, 0, "Log all incoming UDP packets");
static struct inpcbhead udb; /* from udp_var.h */
struct inpcbinfo udbinfo;
#ifndef UDBHASHSIZE
#define UDBHASHSIZE 16
#endif
static struct udpstat udpstat; /* from udp_var.h */
SYSCTL_STRUCT(_net_inet_udp, UDPCTL_STATS, stats, CTLFLAG_RD,
&udpstat, udpstat, "UDP statistics (struct udpstat, netinet/udp_var.h)");
static struct sockaddr_in udp_in = { sizeof(udp_in), AF_INET };
static int udp_output __P((struct inpcb *, struct mbuf *, struct sockaddr *,
struct mbuf *, struct proc *));
static void udp_notify __P((struct inpcb *, int));
void
udp_init()
{
LIST_INIT(&udb);
udbinfo.listhead = &udb;
udbinfo.hashbase = hashinit(UDBHASHSIZE, M_PCB, &udbinfo.hashmask);
udbinfo.porthashbase = hashinit(UDBHASHSIZE, M_PCB,
&udbinfo.porthashmask);
udbinfo.ipi_zone = zinit("udpcb", sizeof(struct inpcb), maxsockets,
ZONE_INTERRUPT, 0);
}
void
udp_input(m, iphlen)
register struct mbuf *m;
int iphlen;
{
register struct ip *ip;
register struct udphdr *uh;
register struct inpcb *inp;
struct mbuf *opts = 0;
int len;
struct ip save_ip;
udpstat.udps_ipackets++;
/*
* Strip IP options, if any; should skip this,
* make available to user, and use on returned packets,
* but we don't yet have a way to check the checksum
* with options still present.
*/
if (iphlen > sizeof (struct ip)) {
ip_stripoptions(m, (struct mbuf *)0);
iphlen = sizeof(struct ip);
}
/*
* Get IP and UDP header together in first mbuf.
*/
ip = mtod(m, struct ip *);
if (m->m_len < iphlen + sizeof(struct udphdr)) {
if ((m = m_pullup(m, iphlen + sizeof(struct udphdr))) == 0) {
udpstat.udps_hdrops++;
return;
}
ip = mtod(m, struct ip *);
}
uh = (struct udphdr *)((caddr_t)ip + iphlen);
/*
* Make mbuf data length reflect UDP length.
* If not enough data to reflect UDP length, drop.
*/
len = ntohs((u_short)uh->uh_ulen);
if (ip->ip_len != len) {
if (len > ip->ip_len || len < sizeof(struct udphdr)) {
udpstat.udps_badlen++;
goto bad;
}
m_adj(m, len - ip->ip_len);
/* ip->ip_len = len; */
}
/*
* Save a copy of the IP header in case we want restore it
* for sending an ICMP error message in response.
*/
save_ip = *ip;
/*
* Checksum extended UDP header and data.
*/
if (uh->uh_sum) {
bzero(((struct ipovly *)ip)->ih_x1, 9);
((struct ipovly *)ip)->ih_len = uh->uh_ulen;
uh->uh_sum = in_cksum(m, len + sizeof (struct ip));
if (uh->uh_sum) {
udpstat.udps_badsum++;
m_freem(m);
return;
}
}
if (IN_MULTICAST(ntohl(ip->ip_dst.s_addr)) ||
in_broadcast(ip->ip_dst, m->m_pkthdr.rcvif)) {
struct inpcb *last;
/*
* Deliver a multicast or broadcast datagram to *all* sockets
* for which the local and remote addresses and ports match
* those of the incoming datagram. This allows more than
* one process to receive multi/broadcasts on the same port.
* (This really ought to be done for unicast datagrams as
* well, but that would cause problems with existing
* applications that open both address-specific sockets and
* a wildcard socket listening to the same port -- they would
* end up receiving duplicates of every unicast datagram.
* Those applications open the multiple sockets to overcome an
* inadequacy of the UDP socket interface, but for backwards
* compatibility we avoid the problem here rather than
* fixing the interface. Maybe 4.5BSD will remedy this?)
*/
/*
* Construct sockaddr format source address.
*/
udp_in.sin_port = uh->uh_sport;
udp_in.sin_addr = ip->ip_src;
m->m_len -= sizeof (struct udpiphdr);
m->m_data += sizeof (struct udpiphdr);
/*
* Locate pcb(s) for datagram.
* (Algorithm copied from raw_intr().)
*/
last = NULL;
for (inp = udb.lh_first; inp != NULL; inp = inp->inp_list.le_next) {
if (inp->inp_lport != uh->uh_dport)
continue;
if (inp->inp_laddr.s_addr != INADDR_ANY) {
if (inp->inp_laddr.s_addr !=
ip->ip_dst.s_addr)
continue;
}
if (inp->inp_faddr.s_addr != INADDR_ANY) {
if (inp->inp_faddr.s_addr !=
ip->ip_src.s_addr ||
inp->inp_fport != uh->uh_sport)
continue;
}
if (last != NULL) {
struct mbuf *n;
if ((n = m_copy(m, 0, M_COPYALL)) != NULL) {
if (last->inp_flags & INP_CONTROLOPTS
|| last->inp_socket->so_options & SO_TIMESTAMP)
ip_savecontrol(last, &opts, ip, n);
if (sbappendaddr(&last->inp_socket->so_rcv,
(struct sockaddr *)&udp_in,
n, opts) == 0) {
m_freem(n);
if (opts)
m_freem(opts);
udpstat.udps_fullsock++;
} else
sorwakeup(last->inp_socket);
opts = 0;
}
}
last = inp;
/*
* Don't look for additional matches if this one does
* not have either the SO_REUSEPORT or SO_REUSEADDR
* socket options set. This heuristic avoids searching
* through all pcbs in the common case of a non-shared
* port. It * assumes that an application will never
* clear these options after setting them.
*/
if ((last->inp_socket->so_options&(SO_REUSEPORT|SO_REUSEADDR)) == 0)
break;
}
if (last == NULL) {
/*
* No matching pcb found; discard datagram.
* (No need to send an ICMP Port Unreachable
* for a broadcast or multicast datgram.)
*/
udpstat.udps_noportbcast++;
goto bad;
}
if (last->inp_flags & INP_CONTROLOPTS
|| last->inp_socket->so_options & SO_TIMESTAMP)
ip_savecontrol(last, &opts, ip, m);
if (sbappendaddr(&last->inp_socket->so_rcv,
(struct sockaddr *)&udp_in,
m, opts) == 0) {
udpstat.udps_fullsock++;
goto bad;
}
sorwakeup(last->inp_socket);
return;
}
/*
* Locate pcb for datagram.
*/
inp = in_pcblookup_hash(&udbinfo, ip->ip_src, uh->uh_sport,
ip->ip_dst, uh->uh_dport, 1);
if (inp == NULL) {
if (log_in_vain) {
char buf[4*sizeof "123"];
strcpy(buf, inet_ntoa(ip->ip_dst));
log(LOG_INFO,
"Connection attempt to UDP %s:%d from %s:%d\n",
buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
ntohs(uh->uh_sport));
}
udpstat.udps_noport++;
if (m->m_flags & (M_BCAST | M_MCAST)) {
udpstat.udps_noportbcast++;
goto bad;
}
*ip = save_ip;
#ifdef ICMP_BANDLIM
if (badport_bandlim(0) < 0)
goto bad;
#endif
icmp_error(m, ICMP_UNREACH, ICMP_UNREACH_PORT, 0, 0);
return;
}
/*
* Construct sockaddr format source address.
* Stuff source address and datagram in user buffer.
*/
udp_in.sin_port = uh->uh_sport;
udp_in.sin_addr = ip->ip_src;
if (inp->inp_flags & INP_CONTROLOPTS
|| inp->inp_socket->so_options & SO_TIMESTAMP)
ip_savecontrol(inp, &opts, ip, m);
iphlen += sizeof(struct udphdr);
m->m_len -= iphlen;
m->m_pkthdr.len -= iphlen;
m->m_data += iphlen;
if (sbappendaddr(&inp->inp_socket->so_rcv, (struct sockaddr *)&udp_in,
m, opts) == 0) {
udpstat.udps_fullsock++;
goto bad;
}
sorwakeup(inp->inp_socket);
return;
bad:
m_freem(m);
if (opts)
m_freem(opts);
}
/*
* Notify a udp user of an asynchronous error;
* just wake up so that he can collect error status.
*/
static void
udp_notify(inp, errno)
register struct inpcb *inp;
int errno;
{
inp->inp_socket->so_error = errno;
sorwakeup(inp->inp_socket);
sowwakeup(inp->inp_socket);
}
void
udp_ctlinput(cmd, sa, vip)
int cmd;
struct sockaddr *sa;
void *vip;
{
register struct ip *ip = vip;
register struct udphdr *uh;
if (!PRC_IS_REDIRECT(cmd) &&
((unsigned)cmd >= PRC_NCMDS || inetctlerrmap[cmd] == 0))
return;
if (ip) {
uh = (struct udphdr *)((caddr_t)ip + (ip->ip_hl << 2));
in_pcbnotify(&udb, sa, uh->uh_dport, ip->ip_src, uh->uh_sport,
cmd, udp_notify);
} else
in_pcbnotify(&udb, sa, 0, zeroin_addr, 0, cmd, udp_notify);
}
static int
udp_pcblist SYSCTL_HANDLER_ARGS
{
int error, i, n, s;
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 == 0) {
n = udbinfo.ipi_count;
req->oldidx = 2 * (sizeof xig)
+ (n + n/8) * sizeof(struct xinpcb);
return 0;
}
if (req->newptr != 0)
return EPERM;
/*
* OK, now we're committed to doing something.
*/
s = splnet();
gencnt = udbinfo.ipi_gencnt;
n = udbinfo.ipi_count;
splx(s);
xig.xig_len = sizeof xig;
xig.xig_count = n;
xig.xig_gen = gencnt;
xig.xig_sogen = so_gencnt;
error = SYSCTL_OUT(req, &xig, sizeof xig);
if (error)
return error;
inp_list = malloc(n * sizeof *inp_list, M_TEMP, M_WAITOK);
if (inp_list == 0)
return ENOMEM;
s = splnet();
for (inp = udbinfo.listhead->lh_first, i = 0; inp && i < n;
inp = inp->inp_list.le_next) {
if (inp->inp_gencnt <= gencnt && !prison_xinpcb(req->p, inp))
inp_list[i++] = inp;
}
splx(s);
n = i;
error = 0;
for (i = 0; i < n; i++) {
inp = inp_list[i];
if (inp->inp_gencnt <= gencnt) {
struct xinpcb xi;
xi.xi_len = sizeof xi;
/* XXX should avoid extra copy */
bcopy(inp, &xi.xi_inp, sizeof *inp);
if (inp->inp_socket)
sotoxsocket(inp->inp_socket, &xi.xi_socket);
error = SYSCTL_OUT(req, &xi, sizeof xi);
}
}
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.
*/
s = splnet();
xig.xig_gen = udbinfo.ipi_gencnt;
xig.xig_sogen = so_gencnt;
xig.xig_count = udbinfo.ipi_count;
splx(s);
error = SYSCTL_OUT(req, &xig, sizeof xig);
}
free(inp_list, M_TEMP);
return error;
}
SYSCTL_PROC(_net_inet_udp, UDPCTL_PCBLIST, pcblist, CTLFLAG_RD, 0, 0,
udp_pcblist, "S,xinpcb", "List of active UDP sockets");
static int
udp_output(inp, m, addr, control, p)
register struct inpcb *inp;
register struct mbuf *m;
struct sockaddr *addr;
struct mbuf *control;
struct proc *p;
{
register struct udpiphdr *ui;
register int len = m->m_pkthdr.len;
struct in_addr laddr;
struct sockaddr_in *sin;
int s = 0, error = 0;
if (control)
m_freem(control); /* XXX */
if (len + sizeof(struct udpiphdr) > IP_MAXPACKET) {
error = EMSGSIZE;
goto release;
}
if (addr) {
sin = (struct sockaddr_in *)addr;
prison_remote_ip(p, 0, &sin->sin_addr.s_addr);
laddr = inp->inp_laddr;
if (inp->inp_faddr.s_addr != INADDR_ANY) {
error = EISCONN;
goto release;
}
/*
* Must block input while temporarily connected.
*/
s = splnet();
error = in_pcbconnect(inp, addr, p);
if (error) {
splx(s);
goto release;
}
} else {
if (inp->inp_faddr.s_addr == INADDR_ANY) {
error = ENOTCONN;
goto release;
}
}
/*
* Calculate data length and get a mbuf
* for UDP and IP headers.
*/
M_PREPEND(m, sizeof(struct udpiphdr), M_DONTWAIT);
if (m == 0) {
error = ENOBUFS;
if (addr)
splx(s);
goto release;
}
/*
* Fill in mbuf with extended UDP header
* and addresses and length put into network format.
*/
ui = mtod(m, struct udpiphdr *);
bzero(ui->ui_x1, sizeof(ui->ui_x1));
ui->ui_pr = IPPROTO_UDP;
ui->ui_len = htons((u_short)len + sizeof (struct udphdr));
ui->ui_src = inp->inp_laddr;
ui->ui_dst = inp->inp_faddr;
ui->ui_sport = inp->inp_lport;
ui->ui_dport = inp->inp_fport;
ui->ui_ulen = ui->ui_len;
/*
* Stuff checksum and output datagram.
*/
ui->ui_sum = 0;
if (udpcksum) {
if ((ui->ui_sum = in_cksum(m, sizeof (struct udpiphdr) + len)) == 0)
ui->ui_sum = 0xffff;
}
((struct ip *)ui)->ip_len = sizeof (struct udpiphdr) + len;
((struct ip *)ui)->ip_ttl = inp->inp_ip_ttl; /* XXX */
((struct ip *)ui)->ip_tos = inp->inp_ip_tos; /* XXX */
udpstat.udps_opackets++;
error = ip_output(m, inp->inp_options, &inp->inp_route,
inp->inp_socket->so_options & (SO_DONTROUTE | SO_BROADCAST),
inp->inp_moptions);
if (addr) {
in_pcbdisconnect(inp);
inp->inp_laddr = laddr; /* XXX rehash? */
splx(s);
}
return (error);
release:
m_freem(m);
return (error);
}
static u_long udp_sendspace = 9216; /* really max datagram size */
/* 40 1K datagrams */
SYSCTL_INT(_net_inet_udp, UDPCTL_MAXDGRAM, maxdgram, CTLFLAG_RW,
&udp_sendspace, 0, "Maximum outgoing UDP datagram size");
static u_long udp_recvspace = 40 * (1024 + sizeof(struct sockaddr_in));
SYSCTL_INT(_net_inet_udp, UDPCTL_RECVSPACE, recvspace, CTLFLAG_RW,
&udp_recvspace, 0, "Maximum incoming UDP datagram size");
static int
udp_abort(struct socket *so)
{
struct inpcb *inp;
int s;
inp = sotoinpcb(so);
if (inp == 0)
return EINVAL; /* ??? possible? panic instead? */
soisdisconnected(so);
s = splnet();
in_pcbdetach(inp);
splx(s);
return 0;
}
static int
udp_attach(struct socket *so, int proto, struct proc *p)
{
struct inpcb *inp;
int s, error;
inp = sotoinpcb(so);
if (inp != 0)
return EINVAL;
s = splnet();
error = in_pcballoc(so, &udbinfo, p);
splx(s);
if (error)
return error;
error = soreserve(so, udp_sendspace, udp_recvspace);
if (error)
return error;
((struct inpcb *) so->so_pcb)->inp_ip_ttl = ip_defttl;
return 0;
}
static int
udp_bind(struct socket *so, struct sockaddr *nam, struct proc *p)
{
struct inpcb *inp;
int s, error;
inp = sotoinpcb(so);
if (inp == 0)
return EINVAL;
s = splnet();
error = in_pcbbind(inp, nam, p);
splx(s);
return error;
}
static int
udp_connect(struct socket *so, struct sockaddr *nam, struct proc *p)
{
struct inpcb *inp;
int s, error;
struct sockaddr_in *sin;
inp = sotoinpcb(so);
if (inp == 0)
return EINVAL;
if (inp->inp_faddr.s_addr != INADDR_ANY)
return EISCONN;
s = splnet();
sin = (struct sockaddr_in *)nam;
prison_remote_ip(p, 0, &sin->sin_addr.s_addr);
error = in_pcbconnect(inp, nam, p);
splx(s);
if (error == 0)
soisconnected(so);
return error;
}
static int
udp_detach(struct socket *so)
{
struct inpcb *inp;
int s;
inp = sotoinpcb(so);
if (inp == 0)
return EINVAL;
s = splnet();
in_pcbdetach(inp);
splx(s);
return 0;
}
static int
udp_disconnect(struct socket *so)
{
struct inpcb *inp;
int s;
inp = sotoinpcb(so);
if (inp == 0)
return EINVAL;
if (inp->inp_faddr.s_addr == INADDR_ANY)
return ENOTCONN;
s = splnet();
in_pcbdisconnect(inp);
inp->inp_laddr.s_addr = INADDR_ANY;
splx(s);
so->so_state &= ~SS_ISCONNECTED; /* XXX */
return 0;
}
static int
udp_send(struct socket *so, int flags, struct mbuf *m, struct sockaddr *addr,
struct mbuf *control, struct proc *p)
{
struct inpcb *inp;
inp = sotoinpcb(so);
if (inp == 0) {
m_freem(m);
return EINVAL;
}
return udp_output(inp, m, addr, control, p);
}
static int
udp_shutdown(struct socket *so)
{
struct inpcb *inp;
inp = sotoinpcb(so);
if (inp == 0)
return EINVAL;
socantsendmore(so);
return 0;
}
struct pr_usrreqs udp_usrreqs = {
udp_abort, pru_accept_notsupp, udp_attach, udp_bind, udp_connect,
pru_connect2_notsupp, in_control, udp_detach, udp_disconnect,
pru_listen_notsupp, in_setpeeraddr, pru_rcvd_notsupp,
pru_rcvoob_notsupp, udp_send, pru_sense_null, udp_shutdown,
in_setsockaddr, sosend, soreceive, sopoll
};