mirror of
https://github.com/freebsd/freebsd-src.git
synced 2024-12-03 14:48:57 +00:00
e413da1358
The full mandoc warnings were:
skipping paragraph macro: PP after SS
skipping paragraph macro: PP after SH
The rendered output (in ascii and html) is not affected by this commit.
Fixes made by script in https://github.com/Tarsnap/freebsd-doc-scripts
Signed-off-by: Graham Percival <gperciva@tarsnap.com>
Reviewed by: jlduran, mhorne
MFC after: 1 week
Sponsored by: Tarsnap Backup Inc.
Pull Request: https://github.com/freebsd/freebsd-src/pull/1524
96 lines
2.8 KiB
Groff
96 lines
2.8 KiB
Groff
.TH IPNAT 4
|
|
.SH NAME
|
|
ipnat \- Network Address Translation kernel interface
|
|
.SH SYNOPSIS
|
|
#include <netinet/ip_compat.h>
|
|
.br
|
|
#include <netinet/ip_fil.h>
|
|
.br
|
|
#include <netinet/ip_proxy.h>
|
|
.br
|
|
#include <netinet/ip_nat.h>
|
|
.SH IOCTLS
|
|
To add and delete rules to the NAT list, two 'basic' ioctls are provided
|
|
for use. The ioctl's are called as:
|
|
.LP
|
|
.nf
|
|
ioctl(fd, SIOCADNAT, struct ipnat **)
|
|
ioctl(fd, SIOCRMNAT, struct ipnat **)
|
|
ioctl(fd, SIOCGNATS, struct natstat **)
|
|
ioctl(fd, SIOCGNATL, struct natlookup **)
|
|
.fi
|
|
.PP
|
|
Unlike \fBipf(4)\fP, there is only a single list supported by the kernel NAT
|
|
interface. An inactive list which can be swapped to is not currently
|
|
supported.
|
|
|
|
These ioctl's are implemented as being routing ioctls and thus the same rules
|
|
for the various routing ioctls and the file descriptor are employed, mainly
|
|
being that the fd must be that of the device associated with the module
|
|
(i.e., /dev/ipl).
|
|
.PP
|
|
The structure used with the NAT interface is described below:
|
|
.LP
|
|
.nf
|
|
typedef struct ipnat {
|
|
struct ipnat *in_next;
|
|
void *in_ifp;
|
|
u_short in_flags;
|
|
u_short in_pnext;
|
|
u_short in_port[2];
|
|
struct in_addr in_in[2];
|
|
struct in_addr in_out[2];
|
|
struct in_addr in_nextip;
|
|
int in_space;
|
|
int in_redir; /* 0 if it's a mapping, 1 if it's a hard redir */
|
|
char in_ifname[IFNAMSIZ];
|
|
} ipnat_t;
|
|
|
|
#define in_pmin in_port[0] /* Also holds static redir port */
|
|
#define in_pmax in_port[1]
|
|
#define in_nip in_nextip.s_addr
|
|
#define in_inip in_in[0].s_addr
|
|
#define in_inmsk in_in[1].s_addr
|
|
#define in_outip in_out[0].s_addr
|
|
#define in_outmsk in_out[1].s_addr
|
|
|
|
.fi
|
|
.PP
|
|
Recognised values for in_redir:
|
|
.LP
|
|
.nf
|
|
#define NAT_MAP 0
|
|
#define NAT_REDIRECT 1
|
|
.fi
|
|
.LP
|
|
\fBNAT statistics\fP
|
|
Statistics on the number of packets mapped, going in and out are kept,
|
|
the number of times a new entry is added and deleted (through expiration) to
|
|
the NAT table and the current usage level of the NAT table.
|
|
.PP
|
|
Pointers to the NAT table inside the kernel, as well as to the top of the
|
|
internal NAT lists constructed with the \fBSIOCADNAT\fP ioctls. The table
|
|
itself is a hash table of size NAT_SIZE (default size is 367).
|
|
.PP
|
|
To retrieve the statistics, the \fBSIOCGNATS\fP ioctl must be used, with
|
|
the appropriate structure passed by reference, as follows:
|
|
.nf
|
|
ioctl(fd, SIOCGNATS, struct natstat *)
|
|
|
|
typedef struct natstat {
|
|
u_long ns_mapped[2];
|
|
u_long ns_added;
|
|
u_long ns_expire;
|
|
u_long ns_inuse;
|
|
nat_t ***ns_table;
|
|
ipnat_t *ns_list;
|
|
} natstat_t;
|
|
.fi
|
|
.SH BUGS
|
|
It would be nice if there were more flexibility when adding and deleting
|
|
filter rules.
|
|
.SH FILES
|
|
/dev/ipnat
|
|
.SH SEE ALSO
|
|
ipf(4), ipnat(5), ipf(8), ipnat(8), ipfstat(8)
|