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Add two more portrange sysctls, which control the area of the below

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IPPORT_RESERVED that is used for selection when bind() is told to allocate
a reserved port.

Also, implement simple sanity checking for all the addresses set, to make
it a little harder for a user/sysadmin to shoot themselves in the feet.
This commit is contained in:
Peter Wemm 1996-08-12 14:05:54 +00:00
parent 54edc0bbbf
commit bbd42ad0e5
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=17541
2 changed files with 52 additions and 17 deletions
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12
sys/netinet/in.h
View File

@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)in.h 8.3 (Berkeley) 1/3/94
* $Id: in.h,v 1.17 1996/04/03 13:52:11 phk Exp $
* $Id: in.h,v 1.18 1996/07/10 19:44:20 julian Exp $
*/
#ifndef _NETINET_IN_H_
@ -88,7 +88,7 @@
* if you trust the remote host to restrict these ports.
*
* The default range of ports and the high range can be changed by
* sysctl(3). (net.inet.ip.port{hi}{first,last}_auto)
* sysctl(3). (net.inet.ip.port{hi,low}{first,last}_auto)
*
* Changing those values has bad security implications if you are
* using a a stateless firewall that is allowing packets outside of that
@ -114,6 +114,14 @@
#define IPPORT_HIFIRSTAUTO 40000
#define IPPORT_HILASTAUTO 44999
/*
* Scanning for a free reserved port return a value below IPPORT_RESERVED,
* but higher than IPPORT_RESERVEDSTART. Traditionally the start value was
* 512, but that conflicts with some well-known-services that firewalls may
* have a fit if we use.
*/
#define IPPORT_RESERVEDSTART 600
/*
* Internet address (a structure for historical reasons)
*/

57
sys/netinet/in_pcb.c
View File

@ -31,7 +31,7 @@
* SUCH DAMAGE.
*
* @(#)in_pcb.c 8.4 (Berkeley) 5/24/95
* $Id: in_pcb.c,v 1.18 1996/03/11 15:13:13 davidg Exp $
* $Id: in_pcb.c,v 1.19 1996/05/31 05:11:22 peter Exp $
*/
#include <sys/param.h>
@ -61,28 +61,56 @@
struct in_addr zeroin_addr;
static void in_pcbinshash __P((struct inpcb *));
static void in_rtchange __P((struct inpcb *, int));
/*
* These configure the range of local port addresses assigned to
* "unspecified" outgoing connections/packets/whatever.
*/
static int ipport_lowfirstauto = IPPORT_RESERVED - 1; /* 1023 */
static int ipport_lowlastauto = IPPORT_RESERVEDSTART; /* 600 */
static int ipport_firstauto = IPPORT_RESERVED; /* 1024 */
static int ipport_lastauto = IPPORT_USERRESERVED; /* 5000 */
static int ipport_hifirstauto = IPPORT_HIFIRSTAUTO; /* 40000 */
static int ipport_hilastauto = IPPORT_HILASTAUTO; /* 44999 */
#define RANGECHK(var, min, max) \
if ((var) < (min)) { (var) = (min); } \
else if ((var) > (max)) { (var) = (max); }
static int
sysctl_net_ipport_check SYSCTL_HANDLER_ARGS
{
int error = sysctl_handle_int(oidp,
oidp->oid_arg1, oidp->oid_arg2, req);
if (!error) {
RANGECHK(ipport_lowfirstauto, 1, IPPORT_RESERVED - 1);
RANGECHK(ipport_lowlastauto, 1, IPPORT_RESERVED - 1);
RANGECHK(ipport_firstauto, IPPORT_RESERVED, USHRT_MAX);
RANGECHK(ipport_lastauto, IPPORT_RESERVED, USHRT_MAX);
RANGECHK(ipport_hifirstauto, IPPORT_RESERVED, USHRT_MAX);
RANGECHK(ipport_hilastauto, IPPORT_RESERVED, USHRT_MAX);
}
return error;
}
#undef RANGECHK
SYSCTL_NODE(_net_inet_ip, IPPROTO_IP, portrange, CTLFLAG_RW, 0, "IP Ports");
SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, first, CTLFLAG_RW,
&ipport_firstauto, 0, "");
SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, last, CTLFLAG_RW,
&ipport_lastauto, 0, "");
SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, hifirst, CTLFLAG_RW,
&ipport_hifirstauto, 0, "");
SYSCTL_INT(_net_inet_ip_portrange, OID_AUTO, hilast, CTLFLAG_RW,
&ipport_hilastauto, 0, "");
static void in_pcbinshash __P((struct inpcb *));
static void in_rtchange __P((struct inpcb *, int));
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowfirst, CTLTYPE_INT|CTLFLAG_RW,
&ipport_lowfirstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, lowlast, CTLTYPE_INT|CTLFLAG_RW,
&ipport_lowlastauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, first, CTLTYPE_INT|CTLFLAG_RW,
&ipport_firstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, last, CTLTYPE_INT|CTLFLAG_RW,
&ipport_lastauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hifirst, CTLTYPE_INT|CTLFLAG_RW,
&ipport_hifirstauto, 0, &sysctl_net_ipport_check, "I", "");
SYSCTL_PROC(_net_inet_ip_portrange, OID_AUTO, hilast, CTLTYPE_INT|CTLFLAG_RW,
&ipport_hilastauto, 0, &sysctl_net_ipport_check, "I", "");
int
in_pcballoc(so, pcbinfo)
@ -180,9 +208,8 @@ in_pcbbind(inp, nam)
} else if (inp->inp_flags & INP_LOWPORT) {
if (error = suser(p->p_ucred, &p->p_acflag))
return (EACCES);
first = IPPORT_RESERVED - 1; /* 1023 */
last = IPPORT_RESERVED / 2; /* traditional - 512 */
*lastport = first; /* restart each time */
first = ipport_lowfirstauto; /* 1023 */
last = ipport_lowlastauto; /* 600 */
} else {
first = ipport_firstauto; /* sysctl */
last = ipport_lastauto;