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Bring over the change switching from using sequential to random

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ephemeral port allocation as implemented in netinet/in_pcb.c rev. 1.143
(initially from OpenBSD) and follow-up commits during the last four and
a half years including rev. 1.157, 1.162 and 1.199.
This now is relying on the same infrastructure as has been implemented
in in_pcb.c since rev. 1.199.

Reviewed by:	silby, rpaulo, mlaier
MFC after:	2 months
This commit is contained in:
Bjoern A. Zeeb 2008-10-20 18:43:59 +00:00
parent 5ce33ccf10
commit dc3c09c89f
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=184096
2 changed files with 54 additions and 46 deletions
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3
sys/netinet/in_pcb.h
View file

@ -449,6 +449,9 @@ extern int ipport_firstauto;
extern int ipport_lastauto;
extern int ipport_hifirstauto;
extern int ipport_hilastauto;
extern int ipport_randomized;
extern int ipport_stoprandom;
extern int ipport_tcpallocs;
extern struct callout ipport_tick_callout;
void in_pcbpurgeif0(struct inpcbinfo *, struct ifnet *);

97
sys/netinet6/in6_src.c
View file

@ -95,6 +95,9 @@ __FBSDID("$FreeBSD$");
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/in_pcb.h>
#include <netinet/ip_var.h>
#include <netinet/udp.h>
#include <netinet/udp_var.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/in6_pcb.h>
@ -774,7 +777,7 @@ in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
INIT_VNET_INET(curvnet);
struct socket *so = inp->inp_socket;
u_int16_t lport = 0, first, last, *lastport;
int count, error = 0, wild = 0;
int count, error = 0, wild = 0, dorandom;
struct inpcbinfo *pcbinfo = inp->inp_pcbinfo;
INP_INFO_WLOCK_ASSERT(pcbinfo);
@ -802,57 +805,59 @@ in6_pcbsetport(struct in6_addr *laddr, struct inpcb *inp, struct ucred *cred)
last = V_ipport_lastauto;
lastport = &pcbinfo->ipi_lastport;
}
/*
* Simple check to ensure all ports are not used up causing
* a deadlock here.
*
* We split the two cases (up and down) so that the direction
* is not being tested on each round of the loop.
* For UDP, use random port allocation as long as the user
* allows it. For TCP (and as of yet unknown) connections,
* use random port allocation only if the user allows it AND
* ipport_tick() allows it.
*/
if (V_ipport_randomized &&
(!V_ipport_stoprandom || pcbinfo == &V_udbinfo))
dorandom = 1;
else
dorandom = 0;
/*
* It makes no sense to do random port allocation if
* we have the only port available.
*/
if (first == last)
dorandom = 0;
/* Make sure to not include UDP packets in the count. */
if (pcbinfo != &V_udbinfo)
V_ipport_tcpallocs++;
/*
* Instead of having two loops further down counting up or down
* make sure that first is always <= last and go with only one
* code path implementing all logic.
*/
if (first > last) {
/*
* counting down
*/
count = first - last;
u_int16_t aux;
do {
if (count-- < 0) { /* completely used? */
/*
* Undo any address bind that may have
* occurred above.
*/
inp->in6p_laddr = in6addr_any;
return (EAGAIN);
}
--*lastport;
if (*lastport > first || *lastport < last)
*lastport = first;
lport = htons(*lastport);
} while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
lport, wild, cred));
} else {
/*
* counting up
*/
count = last - first;
do {
if (count-- < 0) { /* completely used? */
/*
* Undo any address bind that may have
* occurred above.
*/
inp->in6p_laddr = in6addr_any;
return (EAGAIN);
}
++*lastport;
if (*lastport < first || *lastport > last)
*lastport = first;
lport = htons(*lastport);
} while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
lport, wild, cred));
aux = first;
first = last;
last = aux;
}
if (dorandom)
*lastport = first + (arc4random() % (last - first));
count = last - first;
do {
if (count-- < 0) { /* completely used? */
/* Undo an address bind that may have occurred. */
inp->in6p_laddr = in6addr_any;
return (EADDRNOTAVAIL);
}
++*lastport;
if (*lastport < first || *lastport > last)
*lastport = first;
lport = htons(*lastport);
} while (in6_pcblookup_local(pcbinfo, &inp->in6p_laddr,
lport, wild, cred));
inp->inp_lport = lport;
if (in_pcbinshash(inp) != 0) {
inp->in6p_laddr = in6addr_any;