freebsd-skq/sys/netgraph/ng_ipfw.c
Pedro F. Giffuni fe267a5590 sys: general adoption of SPDX licensing ID tags.
Mainly focus on files that use BSD 2-Clause license, however the tool I
was using misidentified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

No functional change intended.
2017-11-27 15:23:17 +00:00

364 lines
8.3 KiB
C

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright 2005, Gleb Smirnoff <glebius@FreeBSD.org>
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mbuf.h>
#include <sys/malloc.h>
#include <sys/ctype.h>
#include <sys/errno.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/if_var.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/in_var.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/ip.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netpfil/ipfw/ip_fw_private.h>
#include <netgraph/ng_message.h>
#include <netgraph/ng_parse.h>
#include <netgraph/ng_ipfw.h>
#include <netgraph/netgraph.h>
static int ng_ipfw_mod_event(module_t mod, int event, void *data);
static ng_constructor_t ng_ipfw_constructor;
static ng_shutdown_t ng_ipfw_shutdown;
static ng_newhook_t ng_ipfw_newhook;
static ng_connect_t ng_ipfw_connect;
static ng_findhook_t ng_ipfw_findhook;
static ng_rcvdata_t ng_ipfw_rcvdata;
static ng_disconnect_t ng_ipfw_disconnect;
static hook_p ng_ipfw_findhook1(node_p, u_int16_t );
static int ng_ipfw_input(struct mbuf **, int, struct ip_fw_args *,
int);
/* We have only one node */
static node_p fw_node;
/* Netgraph node type descriptor */
static struct ng_type ng_ipfw_typestruct = {
.version = NG_ABI_VERSION,
.name = NG_IPFW_NODE_TYPE,
.mod_event = ng_ipfw_mod_event,
.constructor = ng_ipfw_constructor,
.shutdown = ng_ipfw_shutdown,
.newhook = ng_ipfw_newhook,
.connect = ng_ipfw_connect,
.findhook = ng_ipfw_findhook,
.rcvdata = ng_ipfw_rcvdata,
.disconnect = ng_ipfw_disconnect,
};
NETGRAPH_INIT(ipfw, &ng_ipfw_typestruct);
MODULE_DEPEND(ng_ipfw, ipfw, 3, 3, 3);
/* Information we store for each hook */
struct ng_ipfw_hook_priv {
hook_p hook;
u_int16_t rulenum;
};
typedef struct ng_ipfw_hook_priv *hpriv_p;
static int
ng_ipfw_mod_event(module_t mod, int event, void *data)
{
int error = 0;
switch (event) {
case MOD_LOAD:
if (ng_ipfw_input_p != NULL) {
error = EEXIST;
break;
}
/* Setup node without any private data */
if ((error = ng_make_node_common(&ng_ipfw_typestruct, &fw_node))
!= 0) {
log(LOG_ERR, "%s: can't create ng_ipfw node", __func__);
break;
}
/* Try to name node */
if (ng_name_node(fw_node, "ipfw") != 0)
log(LOG_WARNING, "%s: failed to name node \"ipfw\"",
__func__);
/* Register hook */
ng_ipfw_input_p = ng_ipfw_input;
break;
case MOD_UNLOAD:
/*
* This won't happen if a node exists.
* ng_ipfw_input_p is already cleared.
*/
break;
default:
error = EOPNOTSUPP;
break;
}
return (error);
}
static int
ng_ipfw_constructor(node_p node)
{
return (EINVAL); /* Only one node */
}
static int
ng_ipfw_newhook(node_p node, hook_p hook, const char *name)
{
hpriv_p hpriv;
u_int16_t rulenum;
const char *cp;
char *endptr;
/* Protect from leading zero */
if (name[0] == '0' && name[1] != '\0')
return (EINVAL);
/* Check that name contains only digits */
for (cp = name; *cp != '\0'; cp++)
if (!isdigit(*cp))
return (EINVAL);
/* Convert it to integer */
rulenum = (u_int16_t)strtol(name, &endptr, 10);
if (*endptr != '\0')
return (EINVAL);
/* Allocate memory for this hook's private data */
hpriv = malloc(sizeof(*hpriv), M_NETGRAPH, M_NOWAIT | M_ZERO);
if (hpriv== NULL)
return (ENOMEM);
hpriv->hook = hook;
hpriv->rulenum = rulenum;
NG_HOOK_SET_PRIVATE(hook, hpriv);
return(0);
}
/*
* Set hooks into queueing mode, to avoid recursion between
* netgraph layer and ip_{input,output}.
*/
static int
ng_ipfw_connect(hook_p hook)
{
NG_HOOK_FORCE_QUEUE(hook);
return (0);
}
/* Look up hook by name */
static hook_p
ng_ipfw_findhook(node_p node, const char *name)
{
u_int16_t n; /* numeric representation of hook */
char *endptr;
n = (u_int16_t)strtol(name, &endptr, 10);
if (*endptr != '\0')
return NULL;
return ng_ipfw_findhook1(node, n);
}
/* Look up hook by rule number */
static hook_p
ng_ipfw_findhook1(node_p node, u_int16_t rulenum)
{
hook_p hook;
hpriv_p hpriv;
LIST_FOREACH(hook, &node->nd_hooks, hk_hooks) {
hpriv = NG_HOOK_PRIVATE(hook);
if (NG_HOOK_IS_VALID(hook) && (hpriv->rulenum == rulenum))
return (hook);
}
return (NULL);
}
static int
ng_ipfw_rcvdata(hook_p hook, item_p item)
{
struct m_tag *tag;
struct ipfw_rule_ref *r;
struct mbuf *m;
struct ip *ip;
NGI_GET_M(item, m);
NG_FREE_ITEM(item);
tag = m_tag_locate(m, MTAG_IPFW_RULE, 0, NULL);
if (tag == NULL) {
NG_FREE_M(m);
return (EINVAL); /* XXX: find smth better */
}
if (m->m_len < sizeof(struct ip) &&
(m = m_pullup(m, sizeof(struct ip))) == NULL)
return (ENOBUFS);
ip = mtod(m, struct ip *);
r = (struct ipfw_rule_ref *)(tag + 1);
if (r->info & IPFW_INFO_IN) {
switch (ip->ip_v) {
#ifdef INET
case IPVERSION:
ip_input(m);
return (0);
#endif
#ifdef INET6
case IPV6_VERSION >> 4:
ip6_input(m);
return (0);
#endif
}
} else {
switch (ip->ip_v) {
#ifdef INET
case IPVERSION:
return (ip_output(m, NULL, NULL, IP_FORWARDING,
NULL, NULL));
#endif
#ifdef INET6
case IPV6_VERSION >> 4:
return (ip6_output(m, NULL, NULL, 0, NULL,
NULL, NULL));
#endif
}
}
/* unknown IP protocol version */
NG_FREE_M(m);
return (EPROTONOSUPPORT);
}
static int
ng_ipfw_input(struct mbuf **m0, int dir, struct ip_fw_args *fwa, int tee)
{
struct mbuf *m;
struct ip *ip;
hook_p hook;
int error = 0;
/*
* Node must be loaded and corresponding hook must be present.
*/
if (fw_node == NULL ||
(hook = ng_ipfw_findhook1(fw_node, fwa->rule.info)) == NULL)
return (ESRCH); /* no hook associated with this rule */
/*
* We have two modes: in normal mode we add a tag to packet, which is
* important to return packet back to IP stack. In tee mode we make
* a copy of a packet and forward it into netgraph without a tag.
*/
if (tee == 0) {
struct m_tag *tag;
struct ipfw_rule_ref *r;
m = *m0;
*m0 = NULL; /* it belongs now to netgraph */
tag = m_tag_alloc(MTAG_IPFW_RULE, 0, sizeof(*r),
M_NOWAIT|M_ZERO);
if (tag == NULL) {
m_freem(m);
return (ENOMEM);
}
r = (struct ipfw_rule_ref *)(tag + 1);
*r = fwa->rule;
r->info &= IPFW_ONEPASS; /* keep this info */
r->info |= dir ? IPFW_INFO_IN : IPFW_INFO_OUT;
m_tag_prepend(m, tag);
} else
if ((m = m_dup(*m0, M_NOWAIT)) == NULL)
return (ENOMEM); /* which is ignored */
if (m->m_len < sizeof(struct ip) &&
(m = m_pullup(m, sizeof(struct ip))) == NULL)
return (EINVAL);
ip = mtod(m, struct ip *);
NG_SEND_DATA_ONLY(error, hook, m);
return (error);
}
static int
ng_ipfw_shutdown(node_p node)
{
/*
* After our single node has been removed,
* the only thing that can be done is
* 'kldunload ng_ipfw.ko'
*/
ng_ipfw_input_p = NULL;
NG_NODE_UNREF(node);
return (0);
}
static int
ng_ipfw_disconnect(hook_p hook)
{
const hpriv_p hpriv = NG_HOOK_PRIVATE(hook);
free(hpriv, M_NETGRAPH);
NG_HOOK_SET_PRIVATE(hook, NULL);
return (0);
}