3448 lines
87 KiB
C
3448 lines
87 KiB
C
/*
|
|
* Copyright (c) 2002 Luigi Rizzo, Universita` di Pisa
|
|
*
|
|
* 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.
|
|
*
|
|
* $FreeBSD$
|
|
*/
|
|
|
|
#define DEB(x)
|
|
#define DDB(x) x
|
|
|
|
/*
|
|
* Implement IP packet firewall (new version)
|
|
*/
|
|
|
|
#if !defined(KLD_MODULE)
|
|
#include "opt_ipfw.h"
|
|
#include "opt_ipdn.h"
|
|
#include "opt_ipdivert.h"
|
|
#include "opt_inet.h"
|
|
#include "opt_ipsec.h"
|
|
#ifndef INET
|
|
#error IPFIREWALL requires INET.
|
|
#endif /* INET */
|
|
#endif
|
|
|
|
#define IPFW2 1
|
|
#if IPFW2
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/jail.h>
|
|
#include <sys/module.h>
|
|
#include <sys/proc.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/sysctl.h>
|
|
#include <sys/syslog.h>
|
|
#include <sys/ucred.h>
|
|
#include <net/if.h>
|
|
#include <net/radix.h>
|
|
#include <net/route.h>
|
|
#include <netinet/in.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/in_var.h>
|
|
#include <netinet/in_pcb.h>
|
|
#include <netinet/ip.h>
|
|
#include <netinet/ip_var.h>
|
|
#include <netinet/ip_icmp.h>
|
|
#include <netinet/ip_fw.h>
|
|
#include <netinet/ip_divert.h>
|
|
#include <netinet/ip_dummynet.h>
|
|
#include <netinet/tcp.h>
|
|
#include <netinet/tcp_timer.h>
|
|
#include <netinet/tcp_var.h>
|
|
#include <netinet/tcpip.h>
|
|
#include <netinet/udp.h>
|
|
#include <netinet/udp_var.h>
|
|
|
|
#ifdef IPSEC
|
|
#include <netinet6/ipsec.h>
|
|
#endif
|
|
|
|
#include <netinet/if_ether.h> /* XXX for ETHERTYPE_IP */
|
|
|
|
#include <machine/in_cksum.h> /* XXX for in_cksum */
|
|
|
|
/*
|
|
* set_disable contains one bit per set value (0..31).
|
|
* If the bit is set, all rules with the corresponding set
|
|
* are disabled. Set RESVD_SET(31) is reserved for the default rule
|
|
* and rules that are not deleted by the flush command,
|
|
* and CANNOT be disabled.
|
|
* Rules in set RESVD_SET can only be deleted explicitly.
|
|
*/
|
|
static u_int32_t set_disable;
|
|
|
|
static int fw_verbose;
|
|
static int verbose_limit;
|
|
|
|
static struct callout ipfw_timeout;
|
|
#define IPFW_DEFAULT_RULE 65535
|
|
|
|
/*
|
|
* Data structure to cache our ucred related
|
|
* information. This structure only gets used if
|
|
* the user specified UID/GID based constraints in
|
|
* a firewall rule.
|
|
*/
|
|
struct ip_fw_ugid {
|
|
gid_t fw_groups[NGROUPS];
|
|
int fw_ngroups;
|
|
uid_t fw_uid;
|
|
int fw_prid;
|
|
};
|
|
|
|
struct ip_fw_chain {
|
|
struct ip_fw *rules; /* list of rules */
|
|
struct ip_fw *reap; /* list of rules to reap */
|
|
struct mtx mtx; /* lock guarding rule list */
|
|
};
|
|
#define IPFW_LOCK_INIT(_chain) \
|
|
mtx_init(&(_chain)->mtx, "IPFW static rules", NULL, \
|
|
MTX_DEF | MTX_RECURSE)
|
|
#define IPFW_LOCK_DESTROY(_chain) mtx_destroy(&(_chain)->mtx)
|
|
#define IPFW_LOCK(_chain) mtx_lock(&(_chain)->mtx)
|
|
#define IPFW_UNLOCK(_chain) mtx_unlock(&(_chain)->mtx)
|
|
#define IPFW_LOCK_ASSERT(_chain) do { \
|
|
mtx_assert(&(_chain)->mtx, MA_OWNED); \
|
|
NET_ASSERT_GIANT(); \
|
|
} while (0)
|
|
|
|
/*
|
|
* list of rules for layer 3
|
|
*/
|
|
static struct ip_fw_chain layer3_chain;
|
|
|
|
MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
|
|
MALLOC_DEFINE(M_IPFW_TBL, "ipfw_tbl", "IpFw tables");
|
|
|
|
struct table_entry {
|
|
struct radix_node rn[2];
|
|
struct sockaddr_in addr, mask;
|
|
u_int32_t value;
|
|
};
|
|
|
|
#define IPFW_TABLES_MAX 128
|
|
static struct {
|
|
struct radix_node_head *rnh;
|
|
int modified;
|
|
} ipfw_tables[IPFW_TABLES_MAX];
|
|
|
|
static int fw_debug = 1;
|
|
static int autoinc_step = 100; /* bounded to 1..1000 in add_rule() */
|
|
|
|
#ifdef SYSCTL_NODE
|
|
SYSCTL_NODE(_net_inet_ip, OID_AUTO, fw, CTLFLAG_RW, 0, "Firewall");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, enable,
|
|
CTLFLAG_RW | CTLFLAG_SECURE3,
|
|
&fw_enable, 0, "Enable ipfw");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, autoinc_step, CTLFLAG_RW,
|
|
&autoinc_step, 0, "Rule number autincrement step");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, one_pass,
|
|
CTLFLAG_RW | CTLFLAG_SECURE3,
|
|
&fw_one_pass, 0,
|
|
"Only do a single pass through ipfw when using dummynet(4)");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, debug, CTLFLAG_RW,
|
|
&fw_debug, 0, "Enable printing of debug ip_fw statements");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose,
|
|
CTLFLAG_RW | CTLFLAG_SECURE3,
|
|
&fw_verbose, 0, "Log matches to ipfw rules");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, verbose_limit, CTLFLAG_RW,
|
|
&verbose_limit, 0, "Set upper limit of matches of ipfw rules logged");
|
|
|
|
/*
|
|
* Description of dynamic rules.
|
|
*
|
|
* Dynamic rules are stored in lists accessed through a hash table
|
|
* (ipfw_dyn_v) whose size is curr_dyn_buckets. This value can
|
|
* be modified through the sysctl variable dyn_buckets which is
|
|
* updated when the table becomes empty.
|
|
*
|
|
* XXX currently there is only one list, ipfw_dyn.
|
|
*
|
|
* When a packet is received, its address fields are first masked
|
|
* with the mask defined for the rule, then hashed, then matched
|
|
* against the entries in the corresponding list.
|
|
* Dynamic rules can be used for different purposes:
|
|
* + stateful rules;
|
|
* + enforcing limits on the number of sessions;
|
|
* + in-kernel NAT (not implemented yet)
|
|
*
|
|
* The lifetime of dynamic rules is regulated by dyn_*_lifetime,
|
|
* measured in seconds and depending on the flags.
|
|
*
|
|
* The total number of dynamic rules is stored in dyn_count.
|
|
* The max number of dynamic rules is dyn_max. When we reach
|
|
* the maximum number of rules we do not create anymore. This is
|
|
* done to avoid consuming too much memory, but also too much
|
|
* time when searching on each packet (ideally, we should try instead
|
|
* to put a limit on the length of the list on each bucket...).
|
|
*
|
|
* Each dynamic rule holds a pointer to the parent ipfw rule so
|
|
* we know what action to perform. Dynamic rules are removed when
|
|
* the parent rule is deleted. XXX we should make them survive.
|
|
*
|
|
* There are some limitations with dynamic rules -- we do not
|
|
* obey the 'randomized match', and we do not do multiple
|
|
* passes through the firewall. XXX check the latter!!!
|
|
*/
|
|
static ipfw_dyn_rule **ipfw_dyn_v = NULL;
|
|
static u_int32_t dyn_buckets = 256; /* must be power of 2 */
|
|
static u_int32_t curr_dyn_buckets = 256; /* must be power of 2 */
|
|
|
|
static struct mtx ipfw_dyn_mtx; /* mutex guarding dynamic rules */
|
|
#define IPFW_DYN_LOCK_INIT() \
|
|
mtx_init(&ipfw_dyn_mtx, "IPFW dynamic rules", NULL, MTX_DEF)
|
|
#define IPFW_DYN_LOCK_DESTROY() mtx_destroy(&ipfw_dyn_mtx)
|
|
#define IPFW_DYN_LOCK() mtx_lock(&ipfw_dyn_mtx)
|
|
#define IPFW_DYN_UNLOCK() mtx_unlock(&ipfw_dyn_mtx)
|
|
#define IPFW_DYN_LOCK_ASSERT() mtx_assert(&ipfw_dyn_mtx, MA_OWNED)
|
|
|
|
/*
|
|
* Timeouts for various events in handing dynamic rules.
|
|
*/
|
|
static u_int32_t dyn_ack_lifetime = 300;
|
|
static u_int32_t dyn_syn_lifetime = 20;
|
|
static u_int32_t dyn_fin_lifetime = 1;
|
|
static u_int32_t dyn_rst_lifetime = 1;
|
|
static u_int32_t dyn_udp_lifetime = 10;
|
|
static u_int32_t dyn_short_lifetime = 5;
|
|
|
|
/*
|
|
* Keepalives are sent if dyn_keepalive is set. They are sent every
|
|
* dyn_keepalive_period seconds, in the last dyn_keepalive_interval
|
|
* seconds of lifetime of a rule.
|
|
* dyn_rst_lifetime and dyn_fin_lifetime should be strictly lower
|
|
* than dyn_keepalive_period.
|
|
*/
|
|
|
|
static u_int32_t dyn_keepalive_interval = 20;
|
|
static u_int32_t dyn_keepalive_period = 5;
|
|
static u_int32_t dyn_keepalive = 1; /* do send keepalives */
|
|
|
|
static u_int32_t static_count; /* # of static rules */
|
|
static u_int32_t static_len; /* size in bytes of static rules */
|
|
static u_int32_t dyn_count; /* # of dynamic rules */
|
|
static u_int32_t dyn_max = 4096; /* max # of dynamic rules */
|
|
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_buckets, CTLFLAG_RW,
|
|
&dyn_buckets, 0, "Number of dyn. buckets");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, curr_dyn_buckets, CTLFLAG_RD,
|
|
&curr_dyn_buckets, 0, "Current Number of dyn. buckets");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_count, CTLFLAG_RD,
|
|
&dyn_count, 0, "Number of dyn. rules");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_max, CTLFLAG_RW,
|
|
&dyn_max, 0, "Max number of dyn. rules");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, static_count, CTLFLAG_RD,
|
|
&static_count, 0, "Number of static rules");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_ack_lifetime, CTLFLAG_RW,
|
|
&dyn_ack_lifetime, 0, "Lifetime of dyn. rules for acks");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_syn_lifetime, CTLFLAG_RW,
|
|
&dyn_syn_lifetime, 0, "Lifetime of dyn. rules for syn");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_fin_lifetime, CTLFLAG_RW,
|
|
&dyn_fin_lifetime, 0, "Lifetime of dyn. rules for fin");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_rst_lifetime, CTLFLAG_RW,
|
|
&dyn_rst_lifetime, 0, "Lifetime of dyn. rules for rst");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_udp_lifetime, CTLFLAG_RW,
|
|
&dyn_udp_lifetime, 0, "Lifetime of dyn. rules for UDP");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_short_lifetime, CTLFLAG_RW,
|
|
&dyn_short_lifetime, 0, "Lifetime of dyn. rules for other situations");
|
|
SYSCTL_INT(_net_inet_ip_fw, OID_AUTO, dyn_keepalive, CTLFLAG_RW,
|
|
&dyn_keepalive, 0, "Enable keepalives for dyn. rules");
|
|
|
|
#endif /* SYSCTL_NODE */
|
|
|
|
|
|
/*
|
|
* This macro maps an ip pointer into a layer3 header pointer of type T
|
|
*/
|
|
#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
|
|
|
|
static __inline int
|
|
icmptype_match(struct ip *ip, ipfw_insn_u32 *cmd)
|
|
{
|
|
int type = L3HDR(struct icmp,ip)->icmp_type;
|
|
|
|
return (type <= ICMP_MAXTYPE && (cmd->d[0] & (1<<type)) );
|
|
}
|
|
|
|
#define TT ( (1 << ICMP_ECHO) | (1 << ICMP_ROUTERSOLICIT) | \
|
|
(1 << ICMP_TSTAMP) | (1 << ICMP_IREQ) | (1 << ICMP_MASKREQ) )
|
|
|
|
static int
|
|
is_icmp_query(struct ip *ip)
|
|
{
|
|
int type = L3HDR(struct icmp, ip)->icmp_type;
|
|
return (type <= ICMP_MAXTYPE && (TT & (1<<type)) );
|
|
}
|
|
#undef TT
|
|
|
|
/*
|
|
* The following checks use two arrays of 8 or 16 bits to store the
|
|
* bits that we want set or clear, respectively. They are in the
|
|
* low and high half of cmd->arg1 or cmd->d[0].
|
|
*
|
|
* We scan options and store the bits we find set. We succeed if
|
|
*
|
|
* (want_set & ~bits) == 0 && (want_clear & ~bits) == want_clear
|
|
*
|
|
* The code is sometimes optimized not to store additional variables.
|
|
*/
|
|
|
|
static int
|
|
flags_match(ipfw_insn *cmd, u_int8_t bits)
|
|
{
|
|
u_char want_clear;
|
|
bits = ~bits;
|
|
|
|
if ( ((cmd->arg1 & 0xff) & bits) != 0)
|
|
return 0; /* some bits we want set were clear */
|
|
want_clear = (cmd->arg1 >> 8) & 0xff;
|
|
if ( (want_clear & bits) != want_clear)
|
|
return 0; /* some bits we want clear were set */
|
|
return 1;
|
|
}
|
|
|
|
static int
|
|
ipopts_match(struct ip *ip, ipfw_insn *cmd)
|
|
{
|
|
int optlen, bits = 0;
|
|
u_char *cp = (u_char *)(ip + 1);
|
|
int x = (ip->ip_hl << 2) - sizeof (struct ip);
|
|
|
|
for (; x > 0; x -= optlen, cp += optlen) {
|
|
int opt = cp[IPOPT_OPTVAL];
|
|
|
|
if (opt == IPOPT_EOL)
|
|
break;
|
|
if (opt == IPOPT_NOP)
|
|
optlen = 1;
|
|
else {
|
|
optlen = cp[IPOPT_OLEN];
|
|
if (optlen <= 0 || optlen > x)
|
|
return 0; /* invalid or truncated */
|
|
}
|
|
switch (opt) {
|
|
|
|
default:
|
|
break;
|
|
|
|
case IPOPT_LSRR:
|
|
bits |= IP_FW_IPOPT_LSRR;
|
|
break;
|
|
|
|
case IPOPT_SSRR:
|
|
bits |= IP_FW_IPOPT_SSRR;
|
|
break;
|
|
|
|
case IPOPT_RR:
|
|
bits |= IP_FW_IPOPT_RR;
|
|
break;
|
|
|
|
case IPOPT_TS:
|
|
bits |= IP_FW_IPOPT_TS;
|
|
break;
|
|
}
|
|
}
|
|
return (flags_match(cmd, bits));
|
|
}
|
|
|
|
static int
|
|
tcpopts_match(struct ip *ip, ipfw_insn *cmd)
|
|
{
|
|
int optlen, bits = 0;
|
|
struct tcphdr *tcp = L3HDR(struct tcphdr,ip);
|
|
u_char *cp = (u_char *)(tcp + 1);
|
|
int x = (tcp->th_off << 2) - sizeof(struct tcphdr);
|
|
|
|
for (; x > 0; x -= optlen, cp += optlen) {
|
|
int opt = cp[0];
|
|
if (opt == TCPOPT_EOL)
|
|
break;
|
|
if (opt == TCPOPT_NOP)
|
|
optlen = 1;
|
|
else {
|
|
optlen = cp[1];
|
|
if (optlen <= 0)
|
|
break;
|
|
}
|
|
|
|
switch (opt) {
|
|
|
|
default:
|
|
break;
|
|
|
|
case TCPOPT_MAXSEG:
|
|
bits |= IP_FW_TCPOPT_MSS;
|
|
break;
|
|
|
|
case TCPOPT_WINDOW:
|
|
bits |= IP_FW_TCPOPT_WINDOW;
|
|
break;
|
|
|
|
case TCPOPT_SACK_PERMITTED:
|
|
case TCPOPT_SACK:
|
|
bits |= IP_FW_TCPOPT_SACK;
|
|
break;
|
|
|
|
case TCPOPT_TIMESTAMP:
|
|
bits |= IP_FW_TCPOPT_TS;
|
|
break;
|
|
|
|
case TCPOPT_CC:
|
|
case TCPOPT_CCNEW:
|
|
case TCPOPT_CCECHO:
|
|
bits |= IP_FW_TCPOPT_CC;
|
|
break;
|
|
}
|
|
}
|
|
return (flags_match(cmd, bits));
|
|
}
|
|
|
|
static int
|
|
iface_match(struct ifnet *ifp, ipfw_insn_if *cmd)
|
|
{
|
|
if (ifp == NULL) /* no iface with this packet, match fails */
|
|
return 0;
|
|
/* Check by name or by IP address */
|
|
if (cmd->name[0] != '\0') { /* match by name */
|
|
/* Check name */
|
|
if (cmd->p.glob) {
|
|
if (fnmatch(cmd->name, ifp->if_xname, 0) == 0)
|
|
return(1);
|
|
} else {
|
|
if (strncmp(ifp->if_xname, cmd->name, IFNAMSIZ) == 0)
|
|
return(1);
|
|
}
|
|
} else {
|
|
struct ifaddr *ia;
|
|
|
|
/* XXX lock? */
|
|
TAILQ_FOREACH(ia, &ifp->if_addrhead, ifa_link) {
|
|
if (ia->ifa_addr == NULL)
|
|
continue;
|
|
if (ia->ifa_addr->sa_family != AF_INET)
|
|
continue;
|
|
if (cmd->p.ip.s_addr == ((struct sockaddr_in *)
|
|
(ia->ifa_addr))->sin_addr.s_addr)
|
|
return(1); /* match */
|
|
}
|
|
}
|
|
return(0); /* no match, fail ... */
|
|
}
|
|
|
|
/*
|
|
* The verify_path function checks if a route to the src exists and
|
|
* if it is reachable via ifp (when provided).
|
|
*
|
|
* The 'verrevpath' option checks that the interface that an IP packet
|
|
* arrives on is the same interface that traffic destined for the
|
|
* packet's source address would be routed out of. The 'versrcreach'
|
|
* option just checks that the source address is reachable via any route
|
|
* (except default) in the routing table. These two are a measure to block
|
|
* forged packets. This is also commonly known as "anti-spoofing" or Unicast
|
|
* Reverse Path Forwarding (Unicast RFP) in Cisco-ese. The name of the knobs
|
|
* is purposely reminiscent of the Cisco IOS command,
|
|
*
|
|
* ip verify unicast reverse-path
|
|
* ip verify unicast source reachable-via any
|
|
*
|
|
* which implements the same functionality. But note that syntax is
|
|
* misleading. The check may be performed on all IP packets whether unicast,
|
|
* multicast, or broadcast.
|
|
*/
|
|
static int
|
|
verify_path(struct in_addr src, struct ifnet *ifp)
|
|
{
|
|
struct route ro;
|
|
struct sockaddr_in *dst;
|
|
|
|
bzero(&ro, sizeof(ro));
|
|
|
|
dst = (struct sockaddr_in *)&(ro.ro_dst);
|
|
dst->sin_family = AF_INET;
|
|
dst->sin_len = sizeof(*dst);
|
|
dst->sin_addr = src;
|
|
rtalloc_ign(&ro, RTF_CLONING);
|
|
|
|
if (ro.ro_rt == NULL)
|
|
return 0;
|
|
|
|
/* if ifp is provided, check for equality with rtentry */
|
|
if (ifp != NULL && ro.ro_rt->rt_ifp != ifp) {
|
|
RTFREE(ro.ro_rt);
|
|
return 0;
|
|
}
|
|
|
|
/* if no ifp provided, check if rtentry is not default route */
|
|
if (ifp == NULL &&
|
|
satosin(rt_key(ro.ro_rt))->sin_addr.s_addr == INADDR_ANY) {
|
|
RTFREE(ro.ro_rt);
|
|
return 0;
|
|
}
|
|
|
|
/* or if this is a blackhole/reject route */
|
|
if (ifp == NULL && ro.ro_rt->rt_flags & (RTF_REJECT|RTF_BLACKHOLE)) {
|
|
RTFREE(ro.ro_rt);
|
|
return 0;
|
|
}
|
|
|
|
/* found valid route */
|
|
RTFREE(ro.ro_rt);
|
|
return 1;
|
|
}
|
|
|
|
|
|
static u_int64_t norule_counter; /* counter for ipfw_log(NULL...) */
|
|
|
|
#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
|
|
#define SNP(buf) buf, sizeof(buf)
|
|
|
|
/*
|
|
* We enter here when we have a rule with O_LOG.
|
|
* XXX this function alone takes about 2Kbytes of code!
|
|
*/
|
|
static void
|
|
ipfw_log(struct ip_fw *f, u_int hlen, struct ether_header *eh,
|
|
struct mbuf *m, struct ifnet *oif)
|
|
{
|
|
char *action;
|
|
int limit_reached = 0;
|
|
char action2[40], proto[48], fragment[28];
|
|
|
|
fragment[0] = '\0';
|
|
proto[0] = '\0';
|
|
|
|
if (f == NULL) { /* bogus pkt */
|
|
if (verbose_limit != 0 && norule_counter >= verbose_limit)
|
|
return;
|
|
norule_counter++;
|
|
if (norule_counter == verbose_limit)
|
|
limit_reached = verbose_limit;
|
|
action = "Refuse";
|
|
} else { /* O_LOG is the first action, find the real one */
|
|
ipfw_insn *cmd = ACTION_PTR(f);
|
|
ipfw_insn_log *l = (ipfw_insn_log *)cmd;
|
|
|
|
if (l->max_log != 0 && l->log_left == 0)
|
|
return;
|
|
l->log_left--;
|
|
if (l->log_left == 0)
|
|
limit_reached = l->max_log;
|
|
cmd += F_LEN(cmd); /* point to first action */
|
|
if (cmd->opcode == O_PROB)
|
|
cmd += F_LEN(cmd);
|
|
|
|
action = action2;
|
|
switch (cmd->opcode) {
|
|
case O_DENY:
|
|
action = "Deny";
|
|
break;
|
|
|
|
case O_REJECT:
|
|
if (cmd->arg1==ICMP_REJECT_RST)
|
|
action = "Reset";
|
|
else if (cmd->arg1==ICMP_UNREACH_HOST)
|
|
action = "Reject";
|
|
else
|
|
snprintf(SNPARGS(action2, 0), "Unreach %d",
|
|
cmd->arg1);
|
|
break;
|
|
|
|
case O_ACCEPT:
|
|
action = "Accept";
|
|
break;
|
|
case O_COUNT:
|
|
action = "Count";
|
|
break;
|
|
case O_DIVERT:
|
|
snprintf(SNPARGS(action2, 0), "Divert %d",
|
|
cmd->arg1);
|
|
break;
|
|
case O_TEE:
|
|
snprintf(SNPARGS(action2, 0), "Tee %d",
|
|
cmd->arg1);
|
|
break;
|
|
case O_SKIPTO:
|
|
snprintf(SNPARGS(action2, 0), "SkipTo %d",
|
|
cmd->arg1);
|
|
break;
|
|
case O_PIPE:
|
|
snprintf(SNPARGS(action2, 0), "Pipe %d",
|
|
cmd->arg1);
|
|
break;
|
|
case O_QUEUE:
|
|
snprintf(SNPARGS(action2, 0), "Queue %d",
|
|
cmd->arg1);
|
|
break;
|
|
case O_FORWARD_IP: {
|
|
ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
|
|
int len;
|
|
|
|
len = snprintf(SNPARGS(action2, 0), "Forward to %s",
|
|
inet_ntoa(sa->sa.sin_addr));
|
|
if (sa->sa.sin_port)
|
|
snprintf(SNPARGS(action2, len), ":%d",
|
|
sa->sa.sin_port);
|
|
}
|
|
break;
|
|
default:
|
|
action = "UNKNOWN";
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (hlen == 0) { /* non-ip */
|
|
snprintf(SNPARGS(proto, 0), "MAC");
|
|
} else {
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
/* these three are all aliases to the same thing */
|
|
struct icmp *const icmp = L3HDR(struct icmp, ip);
|
|
struct tcphdr *const tcp = (struct tcphdr *)icmp;
|
|
struct udphdr *const udp = (struct udphdr *)icmp;
|
|
|
|
int ip_off, offset, ip_len;
|
|
|
|
int len;
|
|
|
|
if (eh != NULL) { /* layer 2 packets are as on the wire */
|
|
ip_off = ntohs(ip->ip_off);
|
|
ip_len = ntohs(ip->ip_len);
|
|
} else {
|
|
ip_off = ip->ip_off;
|
|
ip_len = ip->ip_len;
|
|
}
|
|
offset = ip_off & IP_OFFMASK;
|
|
switch (ip->ip_p) {
|
|
case IPPROTO_TCP:
|
|
len = snprintf(SNPARGS(proto, 0), "TCP %s",
|
|
inet_ntoa(ip->ip_src));
|
|
if (offset == 0)
|
|
snprintf(SNPARGS(proto, len), ":%d %s:%d",
|
|
ntohs(tcp->th_sport),
|
|
inet_ntoa(ip->ip_dst),
|
|
ntohs(tcp->th_dport));
|
|
else
|
|
snprintf(SNPARGS(proto, len), " %s",
|
|
inet_ntoa(ip->ip_dst));
|
|
break;
|
|
|
|
case IPPROTO_UDP:
|
|
len = snprintf(SNPARGS(proto, 0), "UDP %s",
|
|
inet_ntoa(ip->ip_src));
|
|
if (offset == 0)
|
|
snprintf(SNPARGS(proto, len), ":%d %s:%d",
|
|
ntohs(udp->uh_sport),
|
|
inet_ntoa(ip->ip_dst),
|
|
ntohs(udp->uh_dport));
|
|
else
|
|
snprintf(SNPARGS(proto, len), " %s",
|
|
inet_ntoa(ip->ip_dst));
|
|
break;
|
|
|
|
case IPPROTO_ICMP:
|
|
if (offset == 0)
|
|
len = snprintf(SNPARGS(proto, 0),
|
|
"ICMP:%u.%u ",
|
|
icmp->icmp_type, icmp->icmp_code);
|
|
else
|
|
len = snprintf(SNPARGS(proto, 0), "ICMP ");
|
|
len += snprintf(SNPARGS(proto, len), "%s",
|
|
inet_ntoa(ip->ip_src));
|
|
snprintf(SNPARGS(proto, len), " %s",
|
|
inet_ntoa(ip->ip_dst));
|
|
break;
|
|
|
|
default:
|
|
len = snprintf(SNPARGS(proto, 0), "P:%d %s", ip->ip_p,
|
|
inet_ntoa(ip->ip_src));
|
|
snprintf(SNPARGS(proto, len), " %s",
|
|
inet_ntoa(ip->ip_dst));
|
|
break;
|
|
}
|
|
|
|
if (ip_off & (IP_MF | IP_OFFMASK))
|
|
snprintf(SNPARGS(fragment, 0), " (frag %d:%d@%d%s)",
|
|
ntohs(ip->ip_id), ip_len - (ip->ip_hl << 2),
|
|
offset << 3,
|
|
(ip_off & IP_MF) ? "+" : "");
|
|
}
|
|
if (oif || m->m_pkthdr.rcvif)
|
|
log(LOG_SECURITY | LOG_INFO,
|
|
"ipfw: %d %s %s %s via %s%s\n",
|
|
f ? f->rulenum : -1,
|
|
action, proto, oif ? "out" : "in",
|
|
oif ? oif->if_xname : m->m_pkthdr.rcvif->if_xname,
|
|
fragment);
|
|
else
|
|
log(LOG_SECURITY | LOG_INFO,
|
|
"ipfw: %d %s %s [no if info]%s\n",
|
|
f ? f->rulenum : -1,
|
|
action, proto, fragment);
|
|
if (limit_reached)
|
|
log(LOG_SECURITY | LOG_NOTICE,
|
|
"ipfw: limit %d reached on entry %d\n",
|
|
limit_reached, f ? f->rulenum : -1);
|
|
}
|
|
|
|
/*
|
|
* IMPORTANT: the hash function for dynamic rules must be commutative
|
|
* in source and destination (ip,port), because rules are bidirectional
|
|
* and we want to find both in the same bucket.
|
|
*/
|
|
static __inline int
|
|
hash_packet(struct ipfw_flow_id *id)
|
|
{
|
|
u_int32_t i;
|
|
|
|
i = (id->dst_ip) ^ (id->src_ip) ^ (id->dst_port) ^ (id->src_port);
|
|
i &= (curr_dyn_buckets - 1);
|
|
return i;
|
|
}
|
|
|
|
/**
|
|
* unlink a dynamic rule from a chain. prev is a pointer to
|
|
* the previous one, q is a pointer to the rule to delete,
|
|
* head is a pointer to the head of the queue.
|
|
* Modifies q and potentially also head.
|
|
*/
|
|
#define UNLINK_DYN_RULE(prev, head, q) { \
|
|
ipfw_dyn_rule *old_q = q; \
|
|
\
|
|
/* remove a refcount to the parent */ \
|
|
if (q->dyn_type == O_LIMIT) \
|
|
q->parent->count--; \
|
|
DEB(printf("ipfw: unlink entry 0x%08x %d -> 0x%08x %d, %d left\n",\
|
|
(q->id.src_ip), (q->id.src_port), \
|
|
(q->id.dst_ip), (q->id.dst_port), dyn_count-1 ); ) \
|
|
if (prev != NULL) \
|
|
prev->next = q = q->next; \
|
|
else \
|
|
head = q = q->next; \
|
|
dyn_count--; \
|
|
free(old_q, M_IPFW); }
|
|
|
|
#define TIME_LEQ(a,b) ((int)((a)-(b)) <= 0)
|
|
|
|
/**
|
|
* Remove dynamic rules pointing to "rule", or all of them if rule == NULL.
|
|
*
|
|
* If keep_me == NULL, rules are deleted even if not expired,
|
|
* otherwise only expired rules are removed.
|
|
*
|
|
* The value of the second parameter is also used to point to identify
|
|
* a rule we absolutely do not want to remove (e.g. because we are
|
|
* holding a reference to it -- this is the case with O_LIMIT_PARENT
|
|
* rules). The pointer is only used for comparison, so any non-null
|
|
* value will do.
|
|
*/
|
|
static void
|
|
remove_dyn_rule(struct ip_fw *rule, ipfw_dyn_rule *keep_me)
|
|
{
|
|
static u_int32_t last_remove = 0;
|
|
|
|
#define FORCE (keep_me == NULL)
|
|
|
|
ipfw_dyn_rule *prev, *q;
|
|
int i, pass = 0, max_pass = 0;
|
|
|
|
IPFW_DYN_LOCK_ASSERT();
|
|
|
|
if (ipfw_dyn_v == NULL || dyn_count == 0)
|
|
return;
|
|
/* do not expire more than once per second, it is useless */
|
|
if (!FORCE && last_remove == time_second)
|
|
return;
|
|
last_remove = time_second;
|
|
|
|
/*
|
|
* because O_LIMIT refer to parent rules, during the first pass only
|
|
* remove child and mark any pending LIMIT_PARENT, and remove
|
|
* them in a second pass.
|
|
*/
|
|
next_pass:
|
|
for (i = 0 ; i < curr_dyn_buckets ; i++) {
|
|
for (prev=NULL, q = ipfw_dyn_v[i] ; q ; ) {
|
|
/*
|
|
* Logic can become complex here, so we split tests.
|
|
*/
|
|
if (q == keep_me)
|
|
goto next;
|
|
if (rule != NULL && rule != q->rule)
|
|
goto next; /* not the one we are looking for */
|
|
if (q->dyn_type == O_LIMIT_PARENT) {
|
|
/*
|
|
* handle parent in the second pass,
|
|
* record we need one.
|
|
*/
|
|
max_pass = 1;
|
|
if (pass == 0)
|
|
goto next;
|
|
if (FORCE && q->count != 0 ) {
|
|
/* XXX should not happen! */
|
|
printf("ipfw: OUCH! cannot remove rule,"
|
|
" count %d\n", q->count);
|
|
}
|
|
} else {
|
|
if (!FORCE &&
|
|
!TIME_LEQ( q->expire, time_second ))
|
|
goto next;
|
|
}
|
|
if (q->dyn_type != O_LIMIT_PARENT || !q->count) {
|
|
UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
|
|
continue;
|
|
}
|
|
next:
|
|
prev=q;
|
|
q=q->next;
|
|
}
|
|
}
|
|
if (pass++ < max_pass)
|
|
goto next_pass;
|
|
}
|
|
|
|
|
|
/**
|
|
* lookup a dynamic rule.
|
|
*/
|
|
static ipfw_dyn_rule *
|
|
lookup_dyn_rule_locked(struct ipfw_flow_id *pkt, int *match_direction,
|
|
struct tcphdr *tcp)
|
|
{
|
|
/*
|
|
* stateful ipfw extensions.
|
|
* Lookup into dynamic session queue
|
|
*/
|
|
#define MATCH_REVERSE 0
|
|
#define MATCH_FORWARD 1
|
|
#define MATCH_NONE 2
|
|
#define MATCH_UNKNOWN 3
|
|
int i, dir = MATCH_NONE;
|
|
ipfw_dyn_rule *prev, *q=NULL;
|
|
|
|
IPFW_DYN_LOCK_ASSERT();
|
|
|
|
if (ipfw_dyn_v == NULL)
|
|
goto done; /* not found */
|
|
i = hash_packet( pkt );
|
|
for (prev=NULL, q = ipfw_dyn_v[i] ; q != NULL ; ) {
|
|
if (q->dyn_type == O_LIMIT_PARENT && q->count)
|
|
goto next;
|
|
if (TIME_LEQ( q->expire, time_second)) { /* expire entry */
|
|
UNLINK_DYN_RULE(prev, ipfw_dyn_v[i], q);
|
|
continue;
|
|
}
|
|
if (pkt->proto == q->id.proto &&
|
|
q->dyn_type != O_LIMIT_PARENT) {
|
|
if (pkt->src_ip == q->id.src_ip &&
|
|
pkt->dst_ip == q->id.dst_ip &&
|
|
pkt->src_port == q->id.src_port &&
|
|
pkt->dst_port == q->id.dst_port ) {
|
|
dir = MATCH_FORWARD;
|
|
break;
|
|
}
|
|
if (pkt->src_ip == q->id.dst_ip &&
|
|
pkt->dst_ip == q->id.src_ip &&
|
|
pkt->src_port == q->id.dst_port &&
|
|
pkt->dst_port == q->id.src_port ) {
|
|
dir = MATCH_REVERSE;
|
|
break;
|
|
}
|
|
}
|
|
next:
|
|
prev = q;
|
|
q = q->next;
|
|
}
|
|
if (q == NULL)
|
|
goto done; /* q = NULL, not found */
|
|
|
|
if ( prev != NULL) { /* found and not in front */
|
|
prev->next = q->next;
|
|
q->next = ipfw_dyn_v[i];
|
|
ipfw_dyn_v[i] = q;
|
|
}
|
|
if (pkt->proto == IPPROTO_TCP) { /* update state according to flags */
|
|
u_char flags = pkt->flags & (TH_FIN|TH_SYN|TH_RST);
|
|
|
|
#define BOTH_SYN (TH_SYN | (TH_SYN << 8))
|
|
#define BOTH_FIN (TH_FIN | (TH_FIN << 8))
|
|
q->state |= (dir == MATCH_FORWARD ) ? flags : (flags << 8);
|
|
switch (q->state) {
|
|
case TH_SYN: /* opening */
|
|
q->expire = time_second + dyn_syn_lifetime;
|
|
break;
|
|
|
|
case BOTH_SYN: /* move to established */
|
|
case BOTH_SYN | TH_FIN : /* one side tries to close */
|
|
case BOTH_SYN | (TH_FIN << 8) :
|
|
if (tcp) {
|
|
#define _SEQ_GE(a,b) ((int)(a) - (int)(b) >= 0)
|
|
u_int32_t ack = ntohl(tcp->th_ack);
|
|
if (dir == MATCH_FORWARD) {
|
|
if (q->ack_fwd == 0 || _SEQ_GE(ack, q->ack_fwd))
|
|
q->ack_fwd = ack;
|
|
else { /* ignore out-of-sequence */
|
|
break;
|
|
}
|
|
} else {
|
|
if (q->ack_rev == 0 || _SEQ_GE(ack, q->ack_rev))
|
|
q->ack_rev = ack;
|
|
else { /* ignore out-of-sequence */
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
q->expire = time_second + dyn_ack_lifetime;
|
|
break;
|
|
|
|
case BOTH_SYN | BOTH_FIN: /* both sides closed */
|
|
if (dyn_fin_lifetime >= dyn_keepalive_period)
|
|
dyn_fin_lifetime = dyn_keepalive_period - 1;
|
|
q->expire = time_second + dyn_fin_lifetime;
|
|
break;
|
|
|
|
default:
|
|
#if 0
|
|
/*
|
|
* reset or some invalid combination, but can also
|
|
* occur if we use keep-state the wrong way.
|
|
*/
|
|
if ( (q->state & ((TH_RST << 8)|TH_RST)) == 0)
|
|
printf("invalid state: 0x%x\n", q->state);
|
|
#endif
|
|
if (dyn_rst_lifetime >= dyn_keepalive_period)
|
|
dyn_rst_lifetime = dyn_keepalive_period - 1;
|
|
q->expire = time_second + dyn_rst_lifetime;
|
|
break;
|
|
}
|
|
} else if (pkt->proto == IPPROTO_UDP) {
|
|
q->expire = time_second + dyn_udp_lifetime;
|
|
} else {
|
|
/* other protocols */
|
|
q->expire = time_second + dyn_short_lifetime;
|
|
}
|
|
done:
|
|
if (match_direction)
|
|
*match_direction = dir;
|
|
return q;
|
|
}
|
|
|
|
static ipfw_dyn_rule *
|
|
lookup_dyn_rule(struct ipfw_flow_id *pkt, int *match_direction,
|
|
struct tcphdr *tcp)
|
|
{
|
|
ipfw_dyn_rule *q;
|
|
|
|
IPFW_DYN_LOCK();
|
|
q = lookup_dyn_rule_locked(pkt, match_direction, tcp);
|
|
if (q == NULL)
|
|
IPFW_DYN_UNLOCK();
|
|
/* NB: return table locked when q is not NULL */
|
|
return q;
|
|
}
|
|
|
|
static void
|
|
realloc_dynamic_table(void)
|
|
{
|
|
IPFW_DYN_LOCK_ASSERT();
|
|
|
|
/*
|
|
* Try reallocation, make sure we have a power of 2 and do
|
|
* not allow more than 64k entries. In case of overflow,
|
|
* default to 1024.
|
|
*/
|
|
|
|
if (dyn_buckets > 65536)
|
|
dyn_buckets = 1024;
|
|
if ((dyn_buckets & (dyn_buckets-1)) != 0) { /* not a power of 2 */
|
|
dyn_buckets = curr_dyn_buckets; /* reset */
|
|
return;
|
|
}
|
|
curr_dyn_buckets = dyn_buckets;
|
|
if (ipfw_dyn_v != NULL)
|
|
free(ipfw_dyn_v, M_IPFW);
|
|
for (;;) {
|
|
ipfw_dyn_v = malloc(curr_dyn_buckets * sizeof(ipfw_dyn_rule *),
|
|
M_IPFW, M_NOWAIT | M_ZERO);
|
|
if (ipfw_dyn_v != NULL || curr_dyn_buckets <= 2)
|
|
break;
|
|
curr_dyn_buckets /= 2;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Install state of type 'type' for a dynamic session.
|
|
* The hash table contains two type of rules:
|
|
* - regular rules (O_KEEP_STATE)
|
|
* - rules for sessions with limited number of sess per user
|
|
* (O_LIMIT). When they are created, the parent is
|
|
* increased by 1, and decreased on delete. In this case,
|
|
* the third parameter is the parent rule and not the chain.
|
|
* - "parent" rules for the above (O_LIMIT_PARENT).
|
|
*/
|
|
static ipfw_dyn_rule *
|
|
add_dyn_rule(struct ipfw_flow_id *id, u_int8_t dyn_type, struct ip_fw *rule)
|
|
{
|
|
ipfw_dyn_rule *r;
|
|
int i;
|
|
|
|
IPFW_DYN_LOCK_ASSERT();
|
|
|
|
if (ipfw_dyn_v == NULL ||
|
|
(dyn_count == 0 && dyn_buckets != curr_dyn_buckets)) {
|
|
realloc_dynamic_table();
|
|
if (ipfw_dyn_v == NULL)
|
|
return NULL; /* failed ! */
|
|
}
|
|
i = hash_packet(id);
|
|
|
|
r = malloc(sizeof *r, M_IPFW, M_NOWAIT | M_ZERO);
|
|
if (r == NULL) {
|
|
printf ("ipfw: sorry cannot allocate state\n");
|
|
return NULL;
|
|
}
|
|
|
|
/* increase refcount on parent, and set pointer */
|
|
if (dyn_type == O_LIMIT) {
|
|
ipfw_dyn_rule *parent = (ipfw_dyn_rule *)rule;
|
|
if ( parent->dyn_type != O_LIMIT_PARENT)
|
|
panic("invalid parent");
|
|
parent->count++;
|
|
r->parent = parent;
|
|
rule = parent->rule;
|
|
}
|
|
|
|
r->id = *id;
|
|
r->expire = time_second + dyn_syn_lifetime;
|
|
r->rule = rule;
|
|
r->dyn_type = dyn_type;
|
|
r->pcnt = r->bcnt = 0;
|
|
r->count = 0;
|
|
|
|
r->bucket = i;
|
|
r->next = ipfw_dyn_v[i];
|
|
ipfw_dyn_v[i] = r;
|
|
dyn_count++;
|
|
DEB(printf("ipfw: add dyn entry ty %d 0x%08x %d -> 0x%08x %d, total %d\n",
|
|
dyn_type,
|
|
(r->id.src_ip), (r->id.src_port),
|
|
(r->id.dst_ip), (r->id.dst_port),
|
|
dyn_count ); )
|
|
return r;
|
|
}
|
|
|
|
/**
|
|
* lookup dynamic parent rule using pkt and rule as search keys.
|
|
* If the lookup fails, then install one.
|
|
*/
|
|
static ipfw_dyn_rule *
|
|
lookup_dyn_parent(struct ipfw_flow_id *pkt, struct ip_fw *rule)
|
|
{
|
|
ipfw_dyn_rule *q;
|
|
int i;
|
|
|
|
IPFW_DYN_LOCK_ASSERT();
|
|
|
|
if (ipfw_dyn_v) {
|
|
i = hash_packet( pkt );
|
|
for (q = ipfw_dyn_v[i] ; q != NULL ; q=q->next)
|
|
if (q->dyn_type == O_LIMIT_PARENT &&
|
|
rule== q->rule &&
|
|
pkt->proto == q->id.proto &&
|
|
pkt->src_ip == q->id.src_ip &&
|
|
pkt->dst_ip == q->id.dst_ip &&
|
|
pkt->src_port == q->id.src_port &&
|
|
pkt->dst_port == q->id.dst_port) {
|
|
q->expire = time_second + dyn_short_lifetime;
|
|
DEB(printf("ipfw: lookup_dyn_parent found 0x%p\n",q);)
|
|
return q;
|
|
}
|
|
}
|
|
return add_dyn_rule(pkt, O_LIMIT_PARENT, rule);
|
|
}
|
|
|
|
/**
|
|
* Install dynamic state for rule type cmd->o.opcode
|
|
*
|
|
* Returns 1 (failure) if state is not installed because of errors or because
|
|
* session limitations are enforced.
|
|
*/
|
|
static int
|
|
install_state(struct ip_fw *rule, ipfw_insn_limit *cmd,
|
|
struct ip_fw_args *args)
|
|
{
|
|
static int last_log;
|
|
|
|
ipfw_dyn_rule *q;
|
|
|
|
DEB(printf("ipfw: install state type %d 0x%08x %u -> 0x%08x %u\n",
|
|
cmd->o.opcode,
|
|
(args->f_id.src_ip), (args->f_id.src_port),
|
|
(args->f_id.dst_ip), (args->f_id.dst_port) );)
|
|
|
|
IPFW_DYN_LOCK();
|
|
|
|
q = lookup_dyn_rule_locked(&args->f_id, NULL, NULL);
|
|
|
|
if (q != NULL) { /* should never occur */
|
|
if (last_log != time_second) {
|
|
last_log = time_second;
|
|
printf("ipfw: install_state: entry already present, done\n");
|
|
}
|
|
IPFW_DYN_UNLOCK();
|
|
return 0;
|
|
}
|
|
|
|
if (dyn_count >= dyn_max)
|
|
/*
|
|
* Run out of slots, try to remove any expired rule.
|
|
*/
|
|
remove_dyn_rule(NULL, (ipfw_dyn_rule *)1);
|
|
|
|
if (dyn_count >= dyn_max) {
|
|
if (last_log != time_second) {
|
|
last_log = time_second;
|
|
printf("ipfw: install_state: Too many dynamic rules\n");
|
|
}
|
|
IPFW_DYN_UNLOCK();
|
|
return 1; /* cannot install, notify caller */
|
|
}
|
|
|
|
switch (cmd->o.opcode) {
|
|
case O_KEEP_STATE: /* bidir rule */
|
|
add_dyn_rule(&args->f_id, O_KEEP_STATE, rule);
|
|
break;
|
|
|
|
case O_LIMIT: /* limit number of sessions */
|
|
{
|
|
u_int16_t limit_mask = cmd->limit_mask;
|
|
struct ipfw_flow_id id;
|
|
ipfw_dyn_rule *parent;
|
|
|
|
DEB(printf("ipfw: installing dyn-limit rule %d\n",
|
|
cmd->conn_limit);)
|
|
|
|
id.dst_ip = id.src_ip = 0;
|
|
id.dst_port = id.src_port = 0;
|
|
id.proto = args->f_id.proto;
|
|
|
|
if (limit_mask & DYN_SRC_ADDR)
|
|
id.src_ip = args->f_id.src_ip;
|
|
if (limit_mask & DYN_DST_ADDR)
|
|
id.dst_ip = args->f_id.dst_ip;
|
|
if (limit_mask & DYN_SRC_PORT)
|
|
id.src_port = args->f_id.src_port;
|
|
if (limit_mask & DYN_DST_PORT)
|
|
id.dst_port = args->f_id.dst_port;
|
|
parent = lookup_dyn_parent(&id, rule);
|
|
if (parent == NULL) {
|
|
printf("ipfw: add parent failed\n");
|
|
return 1;
|
|
}
|
|
if (parent->count >= cmd->conn_limit) {
|
|
/*
|
|
* See if we can remove some expired rule.
|
|
*/
|
|
remove_dyn_rule(rule, parent);
|
|
if (parent->count >= cmd->conn_limit) {
|
|
if (fw_verbose && last_log != time_second) {
|
|
last_log = time_second;
|
|
log(LOG_SECURITY | LOG_DEBUG,
|
|
"drop session, too many entries\n");
|
|
}
|
|
IPFW_DYN_UNLOCK();
|
|
return 1;
|
|
}
|
|
}
|
|
add_dyn_rule(&args->f_id, O_LIMIT, (struct ip_fw *)parent);
|
|
}
|
|
break;
|
|
default:
|
|
printf("ipfw: unknown dynamic rule type %u\n", cmd->o.opcode);
|
|
IPFW_DYN_UNLOCK();
|
|
return 1;
|
|
}
|
|
lookup_dyn_rule_locked(&args->f_id, NULL, NULL); /* XXX just set lifetime */
|
|
IPFW_DYN_UNLOCK();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Transmit a TCP packet, containing either a RST or a keepalive.
|
|
* When flags & TH_RST, we are sending a RST packet, because of a
|
|
* "reset" action matched the packet.
|
|
* Otherwise we are sending a keepalive, and flags & TH_
|
|
*/
|
|
static void
|
|
send_pkt(struct ipfw_flow_id *id, u_int32_t seq, u_int32_t ack, int flags)
|
|
{
|
|
struct mbuf *m;
|
|
struct ip *ip;
|
|
struct tcphdr *tcp;
|
|
|
|
MGETHDR(m, M_DONTWAIT, MT_HEADER);
|
|
if (m == 0)
|
|
return;
|
|
m->m_pkthdr.rcvif = (struct ifnet *)0;
|
|
m->m_pkthdr.len = m->m_len = sizeof(struct ip) + sizeof(struct tcphdr);
|
|
m->m_data += max_linkhdr;
|
|
|
|
ip = mtod(m, struct ip *);
|
|
bzero(ip, m->m_len);
|
|
tcp = (struct tcphdr *)(ip + 1); /* no IP options */
|
|
ip->ip_p = IPPROTO_TCP;
|
|
tcp->th_off = 5;
|
|
/*
|
|
* Assume we are sending a RST (or a keepalive in the reverse
|
|
* direction), swap src and destination addresses and ports.
|
|
*/
|
|
ip->ip_src.s_addr = htonl(id->dst_ip);
|
|
ip->ip_dst.s_addr = htonl(id->src_ip);
|
|
tcp->th_sport = htons(id->dst_port);
|
|
tcp->th_dport = htons(id->src_port);
|
|
if (flags & TH_RST) { /* we are sending a RST */
|
|
if (flags & TH_ACK) {
|
|
tcp->th_seq = htonl(ack);
|
|
tcp->th_ack = htonl(0);
|
|
tcp->th_flags = TH_RST;
|
|
} else {
|
|
if (flags & TH_SYN)
|
|
seq++;
|
|
tcp->th_seq = htonl(0);
|
|
tcp->th_ack = htonl(seq);
|
|
tcp->th_flags = TH_RST | TH_ACK;
|
|
}
|
|
} else {
|
|
/*
|
|
* We are sending a keepalive. flags & TH_SYN determines
|
|
* the direction, forward if set, reverse if clear.
|
|
* NOTE: seq and ack are always assumed to be correct
|
|
* as set by the caller. This may be confusing...
|
|
*/
|
|
if (flags & TH_SYN) {
|
|
/*
|
|
* we have to rewrite the correct addresses!
|
|
*/
|
|
ip->ip_dst.s_addr = htonl(id->dst_ip);
|
|
ip->ip_src.s_addr = htonl(id->src_ip);
|
|
tcp->th_dport = htons(id->dst_port);
|
|
tcp->th_sport = htons(id->src_port);
|
|
}
|
|
tcp->th_seq = htonl(seq);
|
|
tcp->th_ack = htonl(ack);
|
|
tcp->th_flags = TH_ACK;
|
|
}
|
|
/*
|
|
* set ip_len to the payload size so we can compute
|
|
* the tcp checksum on the pseudoheader
|
|
* XXX check this, could save a couple of words ?
|
|
*/
|
|
ip->ip_len = htons(sizeof(struct tcphdr));
|
|
tcp->th_sum = in_cksum(m, m->m_pkthdr.len);
|
|
/*
|
|
* now fill fields left out earlier
|
|
*/
|
|
ip->ip_ttl = ip_defttl;
|
|
ip->ip_len = m->m_pkthdr.len;
|
|
m->m_flags |= M_SKIP_FIREWALL;
|
|
ip_output(m, NULL, NULL, 0, NULL, NULL);
|
|
}
|
|
|
|
/*
|
|
* sends a reject message, consuming the mbuf passed as an argument.
|
|
*/
|
|
static void
|
|
send_reject(struct ip_fw_args *args, int code, int offset, int ip_len)
|
|
{
|
|
|
|
if (code != ICMP_REJECT_RST) { /* Send an ICMP unreach */
|
|
/* We need the IP header in host order for icmp_error(). */
|
|
if (args->eh != NULL) {
|
|
struct ip *ip = mtod(args->m, struct ip *);
|
|
ip->ip_len = ntohs(ip->ip_len);
|
|
ip->ip_off = ntohs(ip->ip_off);
|
|
}
|
|
icmp_error(args->m, ICMP_UNREACH, code, 0L, 0);
|
|
} else if (offset == 0 && args->f_id.proto == IPPROTO_TCP) {
|
|
struct tcphdr *const tcp =
|
|
L3HDR(struct tcphdr, mtod(args->m, struct ip *));
|
|
if ( (tcp->th_flags & TH_RST) == 0)
|
|
send_pkt(&(args->f_id), ntohl(tcp->th_seq),
|
|
ntohl(tcp->th_ack),
|
|
tcp->th_flags | TH_RST);
|
|
m_freem(args->m);
|
|
} else
|
|
m_freem(args->m);
|
|
args->m = NULL;
|
|
}
|
|
|
|
/**
|
|
*
|
|
* Given an ip_fw *, lookup_next_rule will return a pointer
|
|
* to the next rule, which can be either the jump
|
|
* target (for skipto instructions) or the next one in the list (in
|
|
* all other cases including a missing jump target).
|
|
* The result is also written in the "next_rule" field of the rule.
|
|
* Backward jumps are not allowed, so start looking from the next
|
|
* rule...
|
|
*
|
|
* This never returns NULL -- in case we do not have an exact match,
|
|
* the next rule is returned. When the ruleset is changed,
|
|
* pointers are flushed so we are always correct.
|
|
*/
|
|
|
|
static struct ip_fw *
|
|
lookup_next_rule(struct ip_fw *me)
|
|
{
|
|
struct ip_fw *rule = NULL;
|
|
ipfw_insn *cmd;
|
|
|
|
/* look for action, in case it is a skipto */
|
|
cmd = ACTION_PTR(me);
|
|
if (cmd->opcode == O_LOG)
|
|
cmd += F_LEN(cmd);
|
|
if ( cmd->opcode == O_SKIPTO )
|
|
for (rule = me->next; rule ; rule = rule->next)
|
|
if (rule->rulenum >= cmd->arg1)
|
|
break;
|
|
if (rule == NULL) /* failure or not a skipto */
|
|
rule = me->next;
|
|
me->next_rule = rule;
|
|
return rule;
|
|
}
|
|
|
|
static void
|
|
init_tables(void)
|
|
{
|
|
int i;
|
|
|
|
for (i = 0; i < IPFW_TABLES_MAX; i++) {
|
|
rn_inithead((void **)&ipfw_tables[i].rnh, 32);
|
|
ipfw_tables[i].modified = 1;
|
|
}
|
|
}
|
|
|
|
static int
|
|
add_table_entry(u_int16_t tbl, in_addr_t addr, u_int8_t mlen, u_int32_t value)
|
|
{
|
|
struct radix_node_head *rnh;
|
|
struct table_entry *ent;
|
|
|
|
if (tbl >= IPFW_TABLES_MAX)
|
|
return (EINVAL);
|
|
rnh = ipfw_tables[tbl].rnh;
|
|
ent = malloc(sizeof(*ent), M_IPFW_TBL, M_NOWAIT | M_ZERO);
|
|
if (ent == NULL)
|
|
return (ENOMEM);
|
|
ent->value = value;
|
|
ent->addr.sin_len = ent->mask.sin_len = 8;
|
|
ent->mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0);
|
|
ent->addr.sin_addr.s_addr = addr & ent->mask.sin_addr.s_addr;
|
|
RADIX_NODE_HEAD_LOCK(rnh);
|
|
if (rnh->rnh_addaddr(&ent->addr, &ent->mask, rnh, (void *)ent) ==
|
|
NULL) {
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
free(ent, M_IPFW_TBL);
|
|
return (EEXIST);
|
|
}
|
|
ipfw_tables[tbl].modified = 1;
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
del_table_entry(u_int16_t tbl, in_addr_t addr, u_int8_t mlen)
|
|
{
|
|
struct radix_node_head *rnh;
|
|
struct table_entry *ent;
|
|
struct sockaddr_in sa, mask;
|
|
|
|
if (tbl >= IPFW_TABLES_MAX)
|
|
return (EINVAL);
|
|
rnh = ipfw_tables[tbl].rnh;
|
|
sa.sin_len = mask.sin_len = 8;
|
|
mask.sin_addr.s_addr = htonl(mlen ? ~((1 << (32 - mlen)) - 1) : 0);
|
|
sa.sin_addr.s_addr = addr & mask.sin_addr.s_addr;
|
|
RADIX_NODE_HEAD_LOCK(rnh);
|
|
ent = (struct table_entry *)rnh->rnh_deladdr(&sa, &mask, rnh);
|
|
if (ent == NULL) {
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
return (ESRCH);
|
|
}
|
|
ipfw_tables[tbl].modified = 1;
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
free(ent, M_IPFW_TBL);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
flush_table_entry(struct radix_node *rn, void *arg)
|
|
{
|
|
struct radix_node_head * const rnh = arg;
|
|
struct table_entry *ent;
|
|
|
|
ent = (struct table_entry *)
|
|
rnh->rnh_deladdr(rn->rn_key, rn->rn_mask, rnh);
|
|
if (ent != NULL)
|
|
free(ent, M_IPFW_TBL);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
flush_table(u_int16_t tbl)
|
|
{
|
|
struct radix_node_head *rnh;
|
|
|
|
if (tbl >= IPFW_TABLES_MAX)
|
|
return (EINVAL);
|
|
rnh = ipfw_tables[tbl].rnh;
|
|
RADIX_NODE_HEAD_LOCK(rnh);
|
|
rnh->rnh_walktree(rnh, flush_table_entry, rnh);
|
|
ipfw_tables[tbl].modified = 1;
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
flush_tables(void)
|
|
{
|
|
u_int16_t tbl;
|
|
|
|
for (tbl = 0; tbl < IPFW_TABLES_MAX; tbl++)
|
|
flush_table(tbl);
|
|
}
|
|
|
|
static int
|
|
lookup_table(u_int16_t tbl, in_addr_t addr, u_int32_t *val)
|
|
{
|
|
struct radix_node_head *rnh;
|
|
struct table_entry *ent;
|
|
struct sockaddr_in sa;
|
|
static in_addr_t last_addr;
|
|
static int last_tbl;
|
|
static int last_match;
|
|
static u_int32_t last_value;
|
|
|
|
if (tbl >= IPFW_TABLES_MAX)
|
|
return (0);
|
|
if (tbl == last_tbl && addr == last_addr &&
|
|
!ipfw_tables[tbl].modified) {
|
|
if (last_match)
|
|
*val = last_value;
|
|
return (last_match);
|
|
}
|
|
rnh = ipfw_tables[tbl].rnh;
|
|
sa.sin_len = 8;
|
|
sa.sin_addr.s_addr = addr;
|
|
RADIX_NODE_HEAD_LOCK(rnh);
|
|
ipfw_tables[tbl].modified = 0;
|
|
ent = (struct table_entry *)(rnh->rnh_lookup(&sa, NULL, rnh));
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
last_addr = addr;
|
|
last_tbl = tbl;
|
|
if (ent != NULL) {
|
|
last_value = *val = ent->value;
|
|
last_match = 1;
|
|
return (1);
|
|
}
|
|
last_match = 0;
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
count_table_entry(struct radix_node *rn, void *arg)
|
|
{
|
|
u_int32_t * const cnt = arg;
|
|
|
|
(*cnt)++;
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
count_table(u_int32_t tbl, u_int32_t *cnt)
|
|
{
|
|
struct radix_node_head *rnh;
|
|
|
|
if (tbl >= IPFW_TABLES_MAX)
|
|
return (EINVAL);
|
|
rnh = ipfw_tables[tbl].rnh;
|
|
*cnt = 0;
|
|
RADIX_NODE_HEAD_LOCK(rnh);
|
|
rnh->rnh_walktree(rnh, count_table_entry, cnt);
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
dump_table_entry(struct radix_node *rn, void *arg)
|
|
{
|
|
struct table_entry * const n = (struct table_entry *)rn;
|
|
ipfw_table * const tbl = arg;
|
|
ipfw_table_entry *ent;
|
|
|
|
if (tbl->cnt == tbl->size)
|
|
return (1);
|
|
ent = &tbl->ent[tbl->cnt];
|
|
ent->tbl = tbl->tbl;
|
|
if (in_nullhost(n->mask.sin_addr))
|
|
ent->masklen = 0;
|
|
else
|
|
ent->masklen = 33 - ffs(ntohl(n->mask.sin_addr.s_addr));
|
|
ent->addr = n->addr.sin_addr.s_addr;
|
|
ent->value = n->value;
|
|
tbl->cnt++;
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
dump_table(ipfw_table *tbl)
|
|
{
|
|
struct radix_node_head *rnh;
|
|
|
|
if (tbl->tbl >= IPFW_TABLES_MAX)
|
|
return (EINVAL);
|
|
rnh = ipfw_tables[tbl->tbl].rnh;
|
|
tbl->cnt = 0;
|
|
RADIX_NODE_HEAD_LOCK(rnh);
|
|
rnh->rnh_walktree(rnh, dump_table_entry, tbl);
|
|
RADIX_NODE_HEAD_UNLOCK(rnh);
|
|
return (0);
|
|
}
|
|
|
|
static int
|
|
check_uidgid(ipfw_insn_u32 *insn,
|
|
int proto, struct ifnet *oif,
|
|
struct in_addr dst_ip, u_int16_t dst_port,
|
|
struct in_addr src_ip, u_int16_t src_port,
|
|
struct ip_fw_ugid *ugp, int *lookup)
|
|
{
|
|
struct inpcbinfo *pi;
|
|
int wildcard;
|
|
struct inpcb *pcb;
|
|
int match;
|
|
struct ucred *cr;
|
|
gid_t *gp;
|
|
|
|
/*
|
|
* If we have already been here and the packet has no
|
|
* PCB entry associated with it, then we can safely
|
|
* assume that this is a no match.
|
|
*/
|
|
if (*lookup == -1)
|
|
return (0);
|
|
if (proto == IPPROTO_TCP) {
|
|
wildcard = 0;
|
|
pi = &tcbinfo;
|
|
} else if (proto == IPPROTO_UDP) {
|
|
wildcard = 1;
|
|
pi = &udbinfo;
|
|
} else
|
|
return 0;
|
|
match = 0;
|
|
if (*lookup == 0) {
|
|
INP_INFO_RLOCK(pi); /* XXX LOR with IPFW */
|
|
pcb = (oif) ?
|
|
in_pcblookup_hash(pi,
|
|
dst_ip, htons(dst_port),
|
|
src_ip, htons(src_port),
|
|
wildcard, oif) :
|
|
in_pcblookup_hash(pi,
|
|
src_ip, htons(src_port),
|
|
dst_ip, htons(dst_port),
|
|
wildcard, NULL);
|
|
if (pcb != NULL) {
|
|
INP_LOCK(pcb);
|
|
if (pcb->inp_socket != NULL) {
|
|
cr = pcb->inp_socket->so_cred;
|
|
ugp->fw_prid = jailed(cr) ?
|
|
cr->cr_prison->pr_id : -1;
|
|
ugp->fw_uid = cr->cr_uid;
|
|
ugp->fw_ngroups = cr->cr_ngroups;
|
|
bcopy(cr->cr_groups, ugp->fw_groups,
|
|
sizeof(ugp->fw_groups));
|
|
*lookup = 1;
|
|
}
|
|
INP_UNLOCK(pcb);
|
|
}
|
|
INP_INFO_RUNLOCK(pi);
|
|
if (*lookup == 0) {
|
|
/*
|
|
* If the lookup did not yield any results, there
|
|
* is no sense in coming back and trying again. So
|
|
* we can set lookup to -1 and ensure that we wont
|
|
* bother the pcb system again.
|
|
*/
|
|
*lookup = -1;
|
|
return (0);
|
|
}
|
|
}
|
|
if (insn->o.opcode == O_UID)
|
|
match = (ugp->fw_uid == (uid_t)insn->d[0]);
|
|
else if (insn->o.opcode == O_GID) {
|
|
for (gp = ugp->fw_groups;
|
|
gp < &ugp->fw_groups[ugp->fw_ngroups]; gp++)
|
|
if (*gp == (gid_t)insn->d[0]) {
|
|
match = 1;
|
|
break;
|
|
}
|
|
} else if (insn->o.opcode == O_JAIL)
|
|
match = (ugp->fw_prid == (int)insn->d[0]);
|
|
return match;
|
|
}
|
|
|
|
/*
|
|
* The main check routine for the firewall.
|
|
*
|
|
* All arguments are in args so we can modify them and return them
|
|
* back to the caller.
|
|
*
|
|
* Parameters:
|
|
*
|
|
* args->m (in/out) The packet; we set to NULL when/if we nuke it.
|
|
* Starts with the IP header.
|
|
* args->eh (in) Mac header if present, or NULL for layer3 packet.
|
|
* args->oif Outgoing interface, or NULL if packet is incoming.
|
|
* The incoming interface is in the mbuf. (in)
|
|
* args->divert_rule (in/out)
|
|
* Skip up to the first rule past this rule number;
|
|
* upon return, non-zero port number for divert or tee.
|
|
*
|
|
* args->rule Pointer to the last matching rule (in/out)
|
|
* args->next_hop Socket we are forwarding to (out).
|
|
* args->f_id Addresses grabbed from the packet (out)
|
|
*
|
|
* Return value:
|
|
*
|
|
* IP_FW_PORT_DENY_FLAG the packet must be dropped.
|
|
* 0 The packet is to be accepted and routed normally OR
|
|
* the packet was denied/rejected and has been dropped;
|
|
* in the latter case, *m is equal to NULL upon return.
|
|
* port Divert the packet to port, with these caveats:
|
|
*
|
|
* - If IP_FW_PORT_TEE_FLAG is set, tee the packet instead
|
|
* of diverting it (ie, 'ipfw tee').
|
|
*
|
|
* - If IP_FW_PORT_DYNT_FLAG is set, interpret the lower
|
|
* 16 bits as a dummynet pipe number instead of diverting
|
|
*/
|
|
|
|
int
|
|
ipfw_chk(struct ip_fw_args *args)
|
|
{
|
|
/*
|
|
* Local variables hold state during the processing of a packet.
|
|
*
|
|
* IMPORTANT NOTE: to speed up the processing of rules, there
|
|
* are some assumption on the values of the variables, which
|
|
* are documented here. Should you change them, please check
|
|
* the implementation of the various instructions to make sure
|
|
* that they still work.
|
|
*
|
|
* args->eh The MAC header. It is non-null for a layer2
|
|
* packet, it is NULL for a layer-3 packet.
|
|
*
|
|
* m | args->m Pointer to the mbuf, as received from the caller.
|
|
* It may change if ipfw_chk() does an m_pullup, or if it
|
|
* consumes the packet because it calls send_reject().
|
|
* XXX This has to change, so that ipfw_chk() never modifies
|
|
* or consumes the buffer.
|
|
* ip is simply an alias of the value of m, and it is kept
|
|
* in sync with it (the packet is supposed to start with
|
|
* the ip header).
|
|
*/
|
|
struct mbuf *m = args->m;
|
|
struct ip *ip = mtod(m, struct ip *);
|
|
|
|
/*
|
|
* For rules which contain uid/gid or jail constraints, cache
|
|
* a copy of the users credentials after the pcb lookup has been
|
|
* executed. This will speed up the processing of rules with
|
|
* these types of constraints, as well as decrease contention
|
|
* on pcb related locks.
|
|
*/
|
|
struct ip_fw_ugid fw_ugid_cache;
|
|
int ugid_lookup = 0;
|
|
|
|
/*
|
|
* oif | args->oif If NULL, ipfw_chk has been called on the
|
|
* inbound path (ether_input, bdg_forward, ip_input).
|
|
* If non-NULL, ipfw_chk has been called on the outbound path
|
|
* (ether_output, ip_output).
|
|
*/
|
|
struct ifnet *oif = args->oif;
|
|
|
|
struct ip_fw *f = NULL; /* matching rule */
|
|
int retval = 0;
|
|
|
|
/*
|
|
* hlen The length of the IPv4 header.
|
|
* hlen >0 means we have an IPv4 packet.
|
|
*/
|
|
u_int hlen = 0; /* hlen >0 means we have an IP pkt */
|
|
|
|
/*
|
|
* offset The offset of a fragment. offset != 0 means that
|
|
* we have a fragment at this offset of an IPv4 packet.
|
|
* offset == 0 means that (if this is an IPv4 packet)
|
|
* this is the first or only fragment.
|
|
*/
|
|
u_short offset = 0;
|
|
|
|
/*
|
|
* Local copies of addresses. They are only valid if we have
|
|
* an IP packet.
|
|
*
|
|
* proto The protocol. Set to 0 for non-ip packets,
|
|
* or to the protocol read from the packet otherwise.
|
|
* proto != 0 means that we have an IPv4 packet.
|
|
*
|
|
* src_port, dst_port port numbers, in HOST format. Only
|
|
* valid for TCP and UDP packets.
|
|
*
|
|
* src_ip, dst_ip ip addresses, in NETWORK format.
|
|
* Only valid for IPv4 packets.
|
|
*/
|
|
u_int8_t proto;
|
|
u_int16_t src_port = 0, dst_port = 0; /* NOTE: host format */
|
|
struct in_addr src_ip, dst_ip; /* NOTE: network format */
|
|
u_int16_t ip_len=0;
|
|
int pktlen;
|
|
int dyn_dir = MATCH_UNKNOWN;
|
|
ipfw_dyn_rule *q = NULL;
|
|
struct ip_fw_chain *chain = &layer3_chain;
|
|
struct m_tag *mtag;
|
|
|
|
if (m->m_flags & M_SKIP_FIREWALL)
|
|
return 0; /* accept */
|
|
/*
|
|
* dyn_dir = MATCH_UNKNOWN when rules unchecked,
|
|
* MATCH_NONE when checked and not matched (q = NULL),
|
|
* MATCH_FORWARD or MATCH_REVERSE otherwise (q != NULL)
|
|
*/
|
|
|
|
pktlen = m->m_pkthdr.len;
|
|
if (args->eh == NULL || /* layer 3 packet */
|
|
( m->m_pkthdr.len >= sizeof(struct ip) &&
|
|
ntohs(args->eh->ether_type) == ETHERTYPE_IP))
|
|
hlen = ip->ip_hl << 2;
|
|
|
|
/*
|
|
* Collect parameters into local variables for faster matching.
|
|
*/
|
|
if (hlen == 0) { /* do not grab addresses for non-ip pkts */
|
|
proto = args->f_id.proto = 0; /* mark f_id invalid */
|
|
goto after_ip_checks;
|
|
}
|
|
|
|
proto = args->f_id.proto = ip->ip_p;
|
|
src_ip = ip->ip_src;
|
|
dst_ip = ip->ip_dst;
|
|
if (args->eh != NULL) { /* layer 2 packets are as on the wire */
|
|
offset = ntohs(ip->ip_off) & IP_OFFMASK;
|
|
ip_len = ntohs(ip->ip_len);
|
|
} else {
|
|
offset = ip->ip_off & IP_OFFMASK;
|
|
ip_len = ip->ip_len;
|
|
}
|
|
pktlen = ip_len < pktlen ? ip_len : pktlen;
|
|
|
|
#define PULLUP_TO(len) \
|
|
do { \
|
|
if ((m)->m_len < (len)) { \
|
|
args->m = m = m_pullup(m, (len)); \
|
|
if (m == 0) \
|
|
goto pullup_failed; \
|
|
ip = mtod(m, struct ip *); \
|
|
} \
|
|
} while (0)
|
|
|
|
if (offset == 0) {
|
|
switch (proto) {
|
|
case IPPROTO_TCP:
|
|
{
|
|
struct tcphdr *tcp;
|
|
|
|
PULLUP_TO(hlen + sizeof(struct tcphdr));
|
|
tcp = L3HDR(struct tcphdr, ip);
|
|
dst_port = tcp->th_dport;
|
|
src_port = tcp->th_sport;
|
|
args->f_id.flags = tcp->th_flags;
|
|
}
|
|
break;
|
|
|
|
case IPPROTO_UDP:
|
|
{
|
|
struct udphdr *udp;
|
|
|
|
PULLUP_TO(hlen + sizeof(struct udphdr));
|
|
udp = L3HDR(struct udphdr, ip);
|
|
dst_port = udp->uh_dport;
|
|
src_port = udp->uh_sport;
|
|
}
|
|
break;
|
|
|
|
case IPPROTO_ICMP:
|
|
PULLUP_TO(hlen + 4); /* type, code and checksum. */
|
|
args->f_id.flags = L3HDR(struct icmp, ip)->icmp_type;
|
|
break;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
#undef PULLUP_TO
|
|
}
|
|
|
|
args->f_id.src_ip = ntohl(src_ip.s_addr);
|
|
args->f_id.dst_ip = ntohl(dst_ip.s_addr);
|
|
args->f_id.src_port = src_port = ntohs(src_port);
|
|
args->f_id.dst_port = dst_port = ntohs(dst_port);
|
|
|
|
after_ip_checks:
|
|
IPFW_LOCK(chain); /* XXX expensive? can we run lock free? */
|
|
mtag = m_tag_find(m, PACKET_TAG_DIVERT, NULL);
|
|
if (args->rule) {
|
|
/*
|
|
* Packet has already been tagged. Look for the next rule
|
|
* to restart processing.
|
|
*
|
|
* If fw_one_pass != 0 then just accept it.
|
|
* XXX should not happen here, but optimized out in
|
|
* the caller.
|
|
*/
|
|
if (fw_one_pass) {
|
|
IPFW_UNLOCK(chain); /* XXX optimize */
|
|
return 0;
|
|
}
|
|
|
|
f = args->rule->next_rule;
|
|
if (f == NULL)
|
|
f = lookup_next_rule(args->rule);
|
|
} else {
|
|
/*
|
|
* Find the starting rule. It can be either the first
|
|
* one, or the one after divert_rule if asked so.
|
|
*/
|
|
int skipto = mtag ? divert_cookie(mtag) : 0;
|
|
|
|
f = chain->rules;
|
|
if (args->eh == NULL && skipto != 0) {
|
|
if (skipto >= IPFW_DEFAULT_RULE) {
|
|
IPFW_UNLOCK(chain);
|
|
return(IP_FW_PORT_DENY_FLAG); /* invalid */
|
|
}
|
|
while (f && f->rulenum <= skipto)
|
|
f = f->next;
|
|
if (f == NULL) { /* drop packet */
|
|
IPFW_UNLOCK(chain);
|
|
return(IP_FW_PORT_DENY_FLAG);
|
|
}
|
|
}
|
|
}
|
|
/* reset divert rule to avoid confusion later */
|
|
if (mtag)
|
|
m_tag_delete(m, mtag);
|
|
|
|
/*
|
|
* Now scan the rules, and parse microinstructions for each rule.
|
|
*/
|
|
for (; f; f = f->next) {
|
|
int l, cmdlen;
|
|
ipfw_insn *cmd;
|
|
int skip_or; /* skip rest of OR block */
|
|
|
|
again:
|
|
if (set_disable & (1 << f->set) )
|
|
continue;
|
|
|
|
skip_or = 0;
|
|
for (l = f->cmd_len, cmd = f->cmd ; l > 0 ;
|
|
l -= cmdlen, cmd += cmdlen) {
|
|
int match;
|
|
|
|
/*
|
|
* check_body is a jump target used when we find a
|
|
* CHECK_STATE, and need to jump to the body of
|
|
* the target rule.
|
|
*/
|
|
|
|
check_body:
|
|
cmdlen = F_LEN(cmd);
|
|
/*
|
|
* An OR block (insn_1 || .. || insn_n) has the
|
|
* F_OR bit set in all but the last instruction.
|
|
* The first match will set "skip_or", and cause
|
|
* the following instructions to be skipped until
|
|
* past the one with the F_OR bit clear.
|
|
*/
|
|
if (skip_or) { /* skip this instruction */
|
|
if ((cmd->len & F_OR) == 0)
|
|
skip_or = 0; /* next one is good */
|
|
continue;
|
|
}
|
|
match = 0; /* set to 1 if we succeed */
|
|
|
|
switch (cmd->opcode) {
|
|
/*
|
|
* The first set of opcodes compares the packet's
|
|
* fields with some pattern, setting 'match' if a
|
|
* match is found. At the end of the loop there is
|
|
* logic to deal with F_NOT and F_OR flags associated
|
|
* with the opcode.
|
|
*/
|
|
case O_NOP:
|
|
match = 1;
|
|
break;
|
|
|
|
case O_FORWARD_MAC:
|
|
printf("ipfw: opcode %d unimplemented\n",
|
|
cmd->opcode);
|
|
break;
|
|
|
|
case O_GID:
|
|
case O_UID:
|
|
case O_JAIL:
|
|
/*
|
|
* We only check offset == 0 && proto != 0,
|
|
* as this ensures that we have an IPv4
|
|
* packet with the ports info.
|
|
*/
|
|
if (offset!=0)
|
|
break;
|
|
if (proto == IPPROTO_TCP ||
|
|
proto == IPPROTO_UDP)
|
|
match = check_uidgid(
|
|
(ipfw_insn_u32 *)cmd,
|
|
proto, oif,
|
|
dst_ip, dst_port,
|
|
src_ip, src_port, &fw_ugid_cache,
|
|
&ugid_lookup);
|
|
break;
|
|
|
|
case O_RECV:
|
|
match = iface_match(m->m_pkthdr.rcvif,
|
|
(ipfw_insn_if *)cmd);
|
|
break;
|
|
|
|
case O_XMIT:
|
|
match = iface_match(oif, (ipfw_insn_if *)cmd);
|
|
break;
|
|
|
|
case O_VIA:
|
|
match = iface_match(oif ? oif :
|
|
m->m_pkthdr.rcvif, (ipfw_insn_if *)cmd);
|
|
break;
|
|
|
|
case O_MACADDR2:
|
|
if (args->eh != NULL) { /* have MAC header */
|
|
u_int32_t *want = (u_int32_t *)
|
|
((ipfw_insn_mac *)cmd)->addr;
|
|
u_int32_t *mask = (u_int32_t *)
|
|
((ipfw_insn_mac *)cmd)->mask;
|
|
u_int32_t *hdr = (u_int32_t *)args->eh;
|
|
|
|
match =
|
|
( want[0] == (hdr[0] & mask[0]) &&
|
|
want[1] == (hdr[1] & mask[1]) &&
|
|
want[2] == (hdr[2] & mask[2]) );
|
|
}
|
|
break;
|
|
|
|
case O_MAC_TYPE:
|
|
if (args->eh != NULL) {
|
|
u_int16_t t =
|
|
ntohs(args->eh->ether_type);
|
|
u_int16_t *p =
|
|
((ipfw_insn_u16 *)cmd)->ports;
|
|
int i;
|
|
|
|
for (i = cmdlen - 1; !match && i>0;
|
|
i--, p += 2)
|
|
match = (t>=p[0] && t<=p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_FRAG:
|
|
match = (hlen > 0 && offset != 0);
|
|
break;
|
|
|
|
case O_IN: /* "out" is "not in" */
|
|
match = (oif == NULL);
|
|
break;
|
|
|
|
case O_LAYER2:
|
|
match = (args->eh != NULL);
|
|
break;
|
|
|
|
case O_PROTO:
|
|
/*
|
|
* We do not allow an arg of 0 so the
|
|
* check of "proto" only suffices.
|
|
*/
|
|
match = (proto == cmd->arg1);
|
|
break;
|
|
|
|
case O_IP_SRC:
|
|
match = (hlen > 0 &&
|
|
((ipfw_insn_ip *)cmd)->addr.s_addr ==
|
|
src_ip.s_addr);
|
|
break;
|
|
|
|
case O_IP_SRC_LOOKUP:
|
|
case O_IP_DST_LOOKUP:
|
|
if (hlen > 0) {
|
|
uint32_t a =
|
|
(cmd->opcode == O_IP_DST_LOOKUP) ?
|
|
dst_ip.s_addr : src_ip.s_addr;
|
|
uint32_t v;
|
|
|
|
match = lookup_table(cmd->arg1, a, &v);
|
|
if (!match)
|
|
break;
|
|
if (cmdlen == F_INSN_SIZE(ipfw_insn_u32))
|
|
match =
|
|
((ipfw_insn_u32 *)cmd)->d[0] == v;
|
|
}
|
|
break;
|
|
|
|
case O_IP_SRC_MASK:
|
|
case O_IP_DST_MASK:
|
|
if (hlen > 0) {
|
|
uint32_t a =
|
|
(cmd->opcode == O_IP_DST_MASK) ?
|
|
dst_ip.s_addr : src_ip.s_addr;
|
|
uint32_t *p = ((ipfw_insn_u32 *)cmd)->d;
|
|
int i = cmdlen-1;
|
|
|
|
for (; !match && i>0; i-= 2, p+= 2)
|
|
match = (p[0] == (a & p[1]));
|
|
}
|
|
break;
|
|
|
|
case O_IP_SRC_ME:
|
|
if (hlen > 0) {
|
|
struct ifnet *tif;
|
|
|
|
INADDR_TO_IFP(src_ip, tif);
|
|
match = (tif != NULL);
|
|
}
|
|
break;
|
|
|
|
case O_IP_DST_SET:
|
|
case O_IP_SRC_SET:
|
|
if (hlen > 0) {
|
|
u_int32_t *d = (u_int32_t *)(cmd+1);
|
|
u_int32_t addr =
|
|
cmd->opcode == O_IP_DST_SET ?
|
|
args->f_id.dst_ip :
|
|
args->f_id.src_ip;
|
|
|
|
if (addr < d[0])
|
|
break;
|
|
addr -= d[0]; /* subtract base */
|
|
match = (addr < cmd->arg1) &&
|
|
( d[ 1 + (addr>>5)] &
|
|
(1<<(addr & 0x1f)) );
|
|
}
|
|
break;
|
|
|
|
case O_IP_DST:
|
|
match = (hlen > 0 &&
|
|
((ipfw_insn_ip *)cmd)->addr.s_addr ==
|
|
dst_ip.s_addr);
|
|
break;
|
|
|
|
case O_IP_DST_ME:
|
|
if (hlen > 0) {
|
|
struct ifnet *tif;
|
|
|
|
INADDR_TO_IFP(dst_ip, tif);
|
|
match = (tif != NULL);
|
|
}
|
|
break;
|
|
|
|
case O_IP_SRCPORT:
|
|
case O_IP_DSTPORT:
|
|
/*
|
|
* offset == 0 && proto != 0 is enough
|
|
* to guarantee that we have an IPv4
|
|
* packet with port info.
|
|
*/
|
|
if ((proto==IPPROTO_UDP || proto==IPPROTO_TCP)
|
|
&& offset == 0) {
|
|
u_int16_t x =
|
|
(cmd->opcode == O_IP_SRCPORT) ?
|
|
src_port : dst_port ;
|
|
u_int16_t *p =
|
|
((ipfw_insn_u16 *)cmd)->ports;
|
|
int i;
|
|
|
|
for (i = cmdlen - 1; !match && i>0;
|
|
i--, p += 2)
|
|
match = (x>=p[0] && x<=p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_ICMPTYPE:
|
|
match = (offset == 0 && proto==IPPROTO_ICMP &&
|
|
icmptype_match(ip, (ipfw_insn_u32 *)cmd) );
|
|
break;
|
|
|
|
case O_IPOPT:
|
|
match = (hlen > 0 && ipopts_match(ip, cmd) );
|
|
break;
|
|
|
|
case O_IPVER:
|
|
match = (hlen > 0 && cmd->arg1 == ip->ip_v);
|
|
break;
|
|
|
|
case O_IPID:
|
|
case O_IPLEN:
|
|
case O_IPTTL:
|
|
if (hlen > 0) { /* only for IP packets */
|
|
uint16_t x;
|
|
uint16_t *p;
|
|
int i;
|
|
|
|
if (cmd->opcode == O_IPLEN)
|
|
x = ip_len;
|
|
else if (cmd->opcode == O_IPTTL)
|
|
x = ip->ip_ttl;
|
|
else /* must be IPID */
|
|
x = ntohs(ip->ip_id);
|
|
if (cmdlen == 1) {
|
|
match = (cmd->arg1 == x);
|
|
break;
|
|
}
|
|
/* otherwise we have ranges */
|
|
p = ((ipfw_insn_u16 *)cmd)->ports;
|
|
i = cmdlen - 1;
|
|
for (; !match && i>0; i--, p += 2)
|
|
match = (x >= p[0] && x <= p[1]);
|
|
}
|
|
break;
|
|
|
|
case O_IPPRECEDENCE:
|
|
match = (hlen > 0 &&
|
|
(cmd->arg1 == (ip->ip_tos & 0xe0)) );
|
|
break;
|
|
|
|
case O_IPTOS:
|
|
match = (hlen > 0 &&
|
|
flags_match(cmd, ip->ip_tos));
|
|
break;
|
|
|
|
case O_TCPFLAGS:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
flags_match(cmd,
|
|
L3HDR(struct tcphdr,ip)->th_flags));
|
|
break;
|
|
|
|
case O_TCPOPTS:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
tcpopts_match(ip, cmd));
|
|
break;
|
|
|
|
case O_TCPSEQ:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
((ipfw_insn_u32 *)cmd)->d[0] ==
|
|
L3HDR(struct tcphdr,ip)->th_seq);
|
|
break;
|
|
|
|
case O_TCPACK:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
((ipfw_insn_u32 *)cmd)->d[0] ==
|
|
L3HDR(struct tcphdr,ip)->th_ack);
|
|
break;
|
|
|
|
case O_TCPWIN:
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
cmd->arg1 ==
|
|
L3HDR(struct tcphdr,ip)->th_win);
|
|
break;
|
|
|
|
case O_ESTAB:
|
|
/* reject packets which have SYN only */
|
|
/* XXX should i also check for TH_ACK ? */
|
|
match = (proto == IPPROTO_TCP && offset == 0 &&
|
|
(L3HDR(struct tcphdr,ip)->th_flags &
|
|
(TH_RST | TH_ACK | TH_SYN)) != TH_SYN);
|
|
break;
|
|
|
|
case O_LOG:
|
|
if (fw_verbose)
|
|
ipfw_log(f, hlen, args->eh, m, oif);
|
|
match = 1;
|
|
break;
|
|
|
|
case O_PROB:
|
|
match = (random()<((ipfw_insn_u32 *)cmd)->d[0]);
|
|
break;
|
|
|
|
case O_VERREVPATH:
|
|
/* Outgoing packets automatically pass/match */
|
|
match = (hlen > 0 && ((oif != NULL) ||
|
|
(m->m_pkthdr.rcvif == NULL) ||
|
|
verify_path(src_ip, m->m_pkthdr.rcvif)));
|
|
break;
|
|
|
|
case O_VERSRCREACH:
|
|
/* Outgoing packets automatically pass/match */
|
|
match = (hlen > 0 && ((oif != NULL) ||
|
|
verify_path(src_ip, NULL)));
|
|
break;
|
|
|
|
case O_ANTISPOOF:
|
|
/* Outgoing packets automatically pass/match */
|
|
if (oif == NULL && hlen > 0 &&
|
|
in_localaddr(src_ip))
|
|
match = verify_path(src_ip,
|
|
m->m_pkthdr.rcvif);
|
|
else
|
|
match = 1;
|
|
break;
|
|
|
|
case O_IPSEC:
|
|
#ifdef FAST_IPSEC
|
|
match = (m_tag_find(m,
|
|
PACKET_TAG_IPSEC_IN_DONE, NULL) != NULL);
|
|
#endif
|
|
#ifdef IPSEC
|
|
match = (ipsec_getnhist(m) != 0);
|
|
#endif
|
|
/* otherwise no match */
|
|
break;
|
|
|
|
/*
|
|
* The second set of opcodes represents 'actions',
|
|
* i.e. the terminal part of a rule once the packet
|
|
* matches all previous patterns.
|
|
* Typically there is only one action for each rule,
|
|
* and the opcode is stored at the end of the rule
|
|
* (but there are exceptions -- see below).
|
|
*
|
|
* In general, here we set retval and terminate the
|
|
* outer loop (would be a 'break 3' in some language,
|
|
* but we need to do a 'goto done').
|
|
*
|
|
* Exceptions:
|
|
* O_COUNT and O_SKIPTO actions:
|
|
* instead of terminating, we jump to the next rule
|
|
* ('goto next_rule', equivalent to a 'break 2'),
|
|
* or to the SKIPTO target ('goto again' after
|
|
* having set f, cmd and l), respectively.
|
|
*
|
|
* O_LIMIT and O_KEEP_STATE: these opcodes are
|
|
* not real 'actions', and are stored right
|
|
* before the 'action' part of the rule.
|
|
* These opcodes try to install an entry in the
|
|
* state tables; if successful, we continue with
|
|
* the next opcode (match=1; break;), otherwise
|
|
* the packet * must be dropped
|
|
* ('goto done' after setting retval);
|
|
*
|
|
* O_PROBE_STATE and O_CHECK_STATE: these opcodes
|
|
* cause a lookup of the state table, and a jump
|
|
* to the 'action' part of the parent rule
|
|
* ('goto check_body') if an entry is found, or
|
|
* (CHECK_STATE only) a jump to the next rule if
|
|
* the entry is not found ('goto next_rule').
|
|
* The result of the lookup is cached to make
|
|
* further instances of these opcodes are
|
|
* effectively NOPs.
|
|
*/
|
|
case O_LIMIT:
|
|
case O_KEEP_STATE:
|
|
if (install_state(f,
|
|
(ipfw_insn_limit *)cmd, args)) {
|
|
retval = IP_FW_PORT_DENY_FLAG;
|
|
goto done; /* error/limit violation */
|
|
}
|
|
match = 1;
|
|
break;
|
|
|
|
case O_PROBE_STATE:
|
|
case O_CHECK_STATE:
|
|
/*
|
|
* dynamic rules are checked at the first
|
|
* keep-state or check-state occurrence,
|
|
* with the result being stored in dyn_dir.
|
|
* The compiler introduces a PROBE_STATE
|
|
* instruction for us when we have a
|
|
* KEEP_STATE (because PROBE_STATE needs
|
|
* to be run first).
|
|
*/
|
|
if (dyn_dir == MATCH_UNKNOWN &&
|
|
(q = lookup_dyn_rule(&args->f_id,
|
|
&dyn_dir, proto == IPPROTO_TCP ?
|
|
L3HDR(struct tcphdr, ip) : NULL))
|
|
!= NULL) {
|
|
/*
|
|
* Found dynamic entry, update stats
|
|
* and jump to the 'action' part of
|
|
* the parent rule.
|
|
*/
|
|
q->pcnt++;
|
|
q->bcnt += pktlen;
|
|
f = q->rule;
|
|
cmd = ACTION_PTR(f);
|
|
l = f->cmd_len - f->act_ofs;
|
|
IPFW_DYN_UNLOCK();
|
|
goto check_body;
|
|
}
|
|
/*
|
|
* Dynamic entry not found. If CHECK_STATE,
|
|
* skip to next rule, if PROBE_STATE just
|
|
* ignore and continue with next opcode.
|
|
*/
|
|
if (cmd->opcode == O_CHECK_STATE)
|
|
goto next_rule;
|
|
match = 1;
|
|
break;
|
|
|
|
case O_ACCEPT:
|
|
retval = 0; /* accept */
|
|
goto done;
|
|
|
|
case O_PIPE:
|
|
case O_QUEUE:
|
|
args->rule = f; /* report matching rule */
|
|
retval = cmd->arg1 | IP_FW_PORT_DYNT_FLAG;
|
|
goto done;
|
|
|
|
case O_DIVERT:
|
|
case O_TEE: {
|
|
struct divert_tag *dt;
|
|
|
|
if (args->eh) /* not on layer 2 */
|
|
break;
|
|
mtag = m_tag_get(PACKET_TAG_DIVERT,
|
|
sizeof(struct divert_tag),
|
|
M_NOWAIT);
|
|
if (mtag == NULL) {
|
|
/* XXX statistic */
|
|
/* drop packet */
|
|
IPFW_UNLOCK(chain);
|
|
return IP_FW_PORT_DENY_FLAG;
|
|
}
|
|
dt = (struct divert_tag *)(mtag+1);
|
|
dt->cookie = f->rulenum;
|
|
dt->info = (cmd->opcode == O_DIVERT) ?
|
|
cmd->arg1 :
|
|
cmd->arg1 | IP_FW_PORT_TEE_FLAG;
|
|
m_tag_prepend(m, mtag);
|
|
retval = dt->info;
|
|
goto done;
|
|
}
|
|
|
|
case O_COUNT:
|
|
case O_SKIPTO:
|
|
f->pcnt++; /* update stats */
|
|
f->bcnt += pktlen;
|
|
f->timestamp = time_second;
|
|
if (cmd->opcode == O_COUNT)
|
|
goto next_rule;
|
|
/* handle skipto */
|
|
if (f->next_rule == NULL)
|
|
lookup_next_rule(f);
|
|
f = f->next_rule;
|
|
goto again;
|
|
|
|
case O_REJECT:
|
|
/*
|
|
* Drop the packet and send a reject notice
|
|
* if the packet is not ICMP (or is an ICMP
|
|
* query), and it is not multicast/broadcast.
|
|
*/
|
|
if (hlen > 0 &&
|
|
(proto != IPPROTO_ICMP ||
|
|
is_icmp_query(ip)) &&
|
|
!(m->m_flags & (M_BCAST|M_MCAST)) &&
|
|
!IN_MULTICAST(ntohl(dst_ip.s_addr))) {
|
|
send_reject(args, cmd->arg1,
|
|
offset,ip_len);
|
|
m = args->m;
|
|
}
|
|
/* FALLTHROUGH */
|
|
case O_DENY:
|
|
retval = IP_FW_PORT_DENY_FLAG;
|
|
goto done;
|
|
|
|
case O_FORWARD_IP:
|
|
if (args->eh) /* not valid on layer2 pkts */
|
|
break;
|
|
if (!q || dyn_dir == MATCH_FORWARD)
|
|
args->next_hop =
|
|
&((ipfw_insn_sa *)cmd)->sa;
|
|
retval = 0;
|
|
goto done;
|
|
|
|
default:
|
|
panic("-- unknown opcode %d\n", cmd->opcode);
|
|
} /* end of switch() on opcodes */
|
|
|
|
if (cmd->len & F_NOT)
|
|
match = !match;
|
|
|
|
if (match) {
|
|
if (cmd->len & F_OR)
|
|
skip_or = 1;
|
|
} else {
|
|
if (!(cmd->len & F_OR)) /* not an OR block, */
|
|
break; /* try next rule */
|
|
}
|
|
|
|
} /* end of inner for, scan opcodes */
|
|
|
|
next_rule:; /* try next rule */
|
|
|
|
} /* end of outer for, scan rules */
|
|
printf("ipfw: ouch!, skip past end of rules, denying packet\n");
|
|
IPFW_UNLOCK(chain);
|
|
return(IP_FW_PORT_DENY_FLAG);
|
|
|
|
done:
|
|
/* Update statistics */
|
|
f->pcnt++;
|
|
f->bcnt += pktlen;
|
|
f->timestamp = time_second;
|
|
IPFW_UNLOCK(chain);
|
|
return retval;
|
|
|
|
pullup_failed:
|
|
if (fw_verbose)
|
|
printf("ipfw: pullup failed\n");
|
|
return(IP_FW_PORT_DENY_FLAG);
|
|
}
|
|
|
|
/*
|
|
* When a rule is added/deleted, clear the next_rule pointers in all rules.
|
|
* These will be reconstructed on the fly as packets are matched.
|
|
*/
|
|
static void
|
|
flush_rule_ptrs(struct ip_fw_chain *chain)
|
|
{
|
|
struct ip_fw *rule;
|
|
|
|
IPFW_LOCK_ASSERT(chain);
|
|
|
|
for (rule = chain->rules; rule; rule = rule->next)
|
|
rule->next_rule = NULL;
|
|
}
|
|
|
|
/*
|
|
* When pipes/queues are deleted, clear the "pipe_ptr" pointer to a given
|
|
* pipe/queue, or to all of them (match == NULL).
|
|
*/
|
|
void
|
|
flush_pipe_ptrs(struct dn_flow_set *match)
|
|
{
|
|
struct ip_fw *rule;
|
|
|
|
IPFW_LOCK(&layer3_chain);
|
|
for (rule = layer3_chain.rules; rule; rule = rule->next) {
|
|
ipfw_insn_pipe *cmd = (ipfw_insn_pipe *)ACTION_PTR(rule);
|
|
|
|
if (cmd->o.opcode != O_PIPE && cmd->o.opcode != O_QUEUE)
|
|
continue;
|
|
/*
|
|
* XXX Use bcmp/bzero to handle pipe_ptr to overcome
|
|
* possible alignment problems on 64-bit architectures.
|
|
* This code is seldom used so we do not worry too
|
|
* much about efficiency.
|
|
*/
|
|
if (match == NULL ||
|
|
!bcmp(&cmd->pipe_ptr, &match, sizeof(match)) )
|
|
bzero(&cmd->pipe_ptr, sizeof(cmd->pipe_ptr));
|
|
}
|
|
IPFW_UNLOCK(&layer3_chain);
|
|
}
|
|
|
|
/*
|
|
* Add a new rule to the list. Copy the rule into a malloc'ed area, then
|
|
* possibly create a rule number and add the rule to the list.
|
|
* Update the rule_number in the input struct so the caller knows it as well.
|
|
*/
|
|
static int
|
|
add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule)
|
|
{
|
|
struct ip_fw *rule, *f, *prev;
|
|
int l = RULESIZE(input_rule);
|
|
|
|
if (chain->rules == NULL && input_rule->rulenum != IPFW_DEFAULT_RULE)
|
|
return (EINVAL);
|
|
|
|
rule = malloc(l, M_IPFW, M_NOWAIT | M_ZERO);
|
|
if (rule == NULL)
|
|
return (ENOSPC);
|
|
|
|
bcopy(input_rule, rule, l);
|
|
|
|
rule->next = NULL;
|
|
rule->next_rule = NULL;
|
|
|
|
rule->pcnt = 0;
|
|
rule->bcnt = 0;
|
|
rule->timestamp = 0;
|
|
|
|
IPFW_LOCK(chain);
|
|
|
|
if (chain->rules == NULL) { /* default rule */
|
|
chain->rules = rule;
|
|
goto done;
|
|
}
|
|
|
|
/*
|
|
* If rulenum is 0, find highest numbered rule before the
|
|
* default rule, and add autoinc_step
|
|
*/
|
|
if (autoinc_step < 1)
|
|
autoinc_step = 1;
|
|
else if (autoinc_step > 1000)
|
|
autoinc_step = 1000;
|
|
if (rule->rulenum == 0) {
|
|
/*
|
|
* locate the highest numbered rule before default
|
|
*/
|
|
for (f = chain->rules; f; f = f->next) {
|
|
if (f->rulenum == IPFW_DEFAULT_RULE)
|
|
break;
|
|
rule->rulenum = f->rulenum;
|
|
}
|
|
if (rule->rulenum < IPFW_DEFAULT_RULE - autoinc_step)
|
|
rule->rulenum += autoinc_step;
|
|
input_rule->rulenum = rule->rulenum;
|
|
}
|
|
|
|
/*
|
|
* Now insert the new rule in the right place in the sorted list.
|
|
*/
|
|
for (prev = NULL, f = chain->rules; f; prev = f, f = f->next) {
|
|
if (f->rulenum > rule->rulenum) { /* found the location */
|
|
if (prev) {
|
|
rule->next = f;
|
|
prev->next = rule;
|
|
} else { /* head insert */
|
|
rule->next = chain->rules;
|
|
chain->rules = rule;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
flush_rule_ptrs(chain);
|
|
done:
|
|
static_count++;
|
|
static_len += l;
|
|
IPFW_UNLOCK(chain);
|
|
DEB(printf("ipfw: installed rule %d, static count now %d\n",
|
|
rule->rulenum, static_count);)
|
|
return (0);
|
|
}
|
|
|
|
/**
|
|
* Remove a static rule (including derived * dynamic rules)
|
|
* and place it on the ``reap list'' for later reclamation.
|
|
* The caller is in charge of clearing rule pointers to avoid
|
|
* dangling pointers.
|
|
* @return a pointer to the next entry.
|
|
* Arguments are not checked, so they better be correct.
|
|
*/
|
|
static struct ip_fw *
|
|
remove_rule(struct ip_fw_chain *chain, struct ip_fw *rule, struct ip_fw *prev)
|
|
{
|
|
struct ip_fw *n;
|
|
int l = RULESIZE(rule);
|
|
|
|
IPFW_LOCK_ASSERT(chain);
|
|
|
|
n = rule->next;
|
|
IPFW_DYN_LOCK();
|
|
remove_dyn_rule(rule, NULL /* force removal */);
|
|
IPFW_DYN_UNLOCK();
|
|
if (prev == NULL)
|
|
chain->rules = n;
|
|
else
|
|
prev->next = n;
|
|
static_count--;
|
|
static_len -= l;
|
|
|
|
rule->next = chain->reap;
|
|
chain->reap = rule;
|
|
|
|
return n;
|
|
}
|
|
|
|
/**
|
|
* Reclaim storage associated with a list of rules. This is
|
|
* typically the list created using remove_rule.
|
|
*/
|
|
static void
|
|
reap_rules(struct ip_fw *head)
|
|
{
|
|
struct ip_fw *rule;
|
|
|
|
while ((rule = head) != NULL) {
|
|
head = head->next;
|
|
if (DUMMYNET_LOADED)
|
|
ip_dn_ruledel_ptr(rule);
|
|
free(rule, M_IPFW);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Remove all rules from a chain (except rules in set RESVD_SET
|
|
* unless kill_default = 1). The caller is responsible for
|
|
* reclaiming storage for the rules left in chain->reap.
|
|
*/
|
|
static void
|
|
free_chain(struct ip_fw_chain *chain, int kill_default)
|
|
{
|
|
struct ip_fw *prev, *rule;
|
|
|
|
IPFW_LOCK_ASSERT(chain);
|
|
|
|
flush_rule_ptrs(chain); /* more efficient to do outside the loop */
|
|
for (prev = NULL, rule = chain->rules; rule ; )
|
|
if (kill_default || rule->set != RESVD_SET)
|
|
rule = remove_rule(chain, rule, prev);
|
|
else {
|
|
prev = rule;
|
|
rule = rule->next;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Remove all rules with given number, and also do set manipulation.
|
|
* Assumes chain != NULL && *chain != NULL.
|
|
*
|
|
* The argument is an u_int32_t. The low 16 bit are the rule or set number,
|
|
* the next 8 bits are the new set, the top 8 bits are the command:
|
|
*
|
|
* 0 delete rules with given number
|
|
* 1 delete rules with given set number
|
|
* 2 move rules with given number to new set
|
|
* 3 move rules with given set number to new set
|
|
* 4 swap sets with given numbers
|
|
*/
|
|
static int
|
|
del_entry(struct ip_fw_chain *chain, u_int32_t arg)
|
|
{
|
|
struct ip_fw *prev = NULL, *rule;
|
|
u_int16_t rulenum; /* rule or old_set */
|
|
u_int8_t cmd, new_set;
|
|
|
|
rulenum = arg & 0xffff;
|
|
cmd = (arg >> 24) & 0xff;
|
|
new_set = (arg >> 16) & 0xff;
|
|
|
|
if (cmd > 4)
|
|
return EINVAL;
|
|
if (new_set > RESVD_SET)
|
|
return EINVAL;
|
|
if (cmd == 0 || cmd == 2) {
|
|
if (rulenum >= IPFW_DEFAULT_RULE)
|
|
return EINVAL;
|
|
} else {
|
|
if (rulenum > RESVD_SET) /* old_set */
|
|
return EINVAL;
|
|
}
|
|
|
|
IPFW_LOCK(chain);
|
|
rule = chain->rules;
|
|
chain->reap = NULL;
|
|
switch (cmd) {
|
|
case 0: /* delete rules with given number */
|
|
/*
|
|
* locate first rule to delete
|
|
*/
|
|
for (; rule->rulenum < rulenum; prev = rule, rule = rule->next)
|
|
;
|
|
if (rule->rulenum != rulenum) {
|
|
IPFW_UNLOCK(chain);
|
|
return EINVAL;
|
|
}
|
|
|
|
/*
|
|
* flush pointers outside the loop, then delete all matching
|
|
* rules. prev remains the same throughout the cycle.
|
|
*/
|
|
flush_rule_ptrs(chain);
|
|
while (rule->rulenum == rulenum)
|
|
rule = remove_rule(chain, rule, prev);
|
|
break;
|
|
|
|
case 1: /* delete all rules with given set number */
|
|
flush_rule_ptrs(chain);
|
|
rule = chain->rules;
|
|
while (rule->rulenum < IPFW_DEFAULT_RULE)
|
|
if (rule->set == rulenum)
|
|
rule = remove_rule(chain, rule, prev);
|
|
else {
|
|
prev = rule;
|
|
rule = rule->next;
|
|
}
|
|
break;
|
|
|
|
case 2: /* move rules with given number to new set */
|
|
rule = chain->rules;
|
|
for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next)
|
|
if (rule->rulenum == rulenum)
|
|
rule->set = new_set;
|
|
break;
|
|
|
|
case 3: /* move rules with given set number to new set */
|
|
for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next)
|
|
if (rule->set == rulenum)
|
|
rule->set = new_set;
|
|
break;
|
|
|
|
case 4: /* swap two sets */
|
|
for (; rule->rulenum < IPFW_DEFAULT_RULE; rule = rule->next)
|
|
if (rule->set == rulenum)
|
|
rule->set = new_set;
|
|
else if (rule->set == new_set)
|
|
rule->set = rulenum;
|
|
break;
|
|
}
|
|
/*
|
|
* Look for rules to reclaim. We grab the list before
|
|
* releasing the lock then reclaim them w/o the lock to
|
|
* avoid a LOR with dummynet.
|
|
*/
|
|
rule = chain->reap;
|
|
chain->reap = NULL;
|
|
IPFW_UNLOCK(chain);
|
|
if (rule)
|
|
reap_rules(rule);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Clear counters for a specific rule.
|
|
* The enclosing "table" is assumed locked.
|
|
*/
|
|
static void
|
|
clear_counters(struct ip_fw *rule, int log_only)
|
|
{
|
|
ipfw_insn_log *l = (ipfw_insn_log *)ACTION_PTR(rule);
|
|
|
|
if (log_only == 0) {
|
|
rule->bcnt = rule->pcnt = 0;
|
|
rule->timestamp = 0;
|
|
}
|
|
if (l->o.opcode == O_LOG)
|
|
l->log_left = l->max_log;
|
|
}
|
|
|
|
/**
|
|
* Reset some or all counters on firewall rules.
|
|
* @arg frwl is null to clear all entries, or contains a specific
|
|
* rule number.
|
|
* @arg log_only is 1 if we only want to reset logs, zero otherwise.
|
|
*/
|
|
static int
|
|
zero_entry(struct ip_fw_chain *chain, int rulenum, int log_only)
|
|
{
|
|
struct ip_fw *rule;
|
|
char *msg;
|
|
|
|
IPFW_LOCK(chain);
|
|
if (rulenum == 0) {
|
|
norule_counter = 0;
|
|
for (rule = chain->rules; rule; rule = rule->next)
|
|
clear_counters(rule, log_only);
|
|
msg = log_only ? "ipfw: All logging counts reset.\n" :
|
|
"ipfw: Accounting cleared.\n";
|
|
} else {
|
|
int cleared = 0;
|
|
/*
|
|
* We can have multiple rules with the same number, so we
|
|
* need to clear them all.
|
|
*/
|
|
for (rule = chain->rules; rule; rule = rule->next)
|
|
if (rule->rulenum == rulenum) {
|
|
while (rule && rule->rulenum == rulenum) {
|
|
clear_counters(rule, log_only);
|
|
rule = rule->next;
|
|
}
|
|
cleared = 1;
|
|
break;
|
|
}
|
|
if (!cleared) { /* we did not find any matching rules */
|
|
IPFW_UNLOCK(chain);
|
|
return (EINVAL);
|
|
}
|
|
msg = log_only ? "ipfw: Entry %d logging count reset.\n" :
|
|
"ipfw: Entry %d cleared.\n";
|
|
}
|
|
IPFW_UNLOCK(chain);
|
|
|
|
if (fw_verbose)
|
|
log(LOG_SECURITY | LOG_NOTICE, msg, rulenum);
|
|
return (0);
|
|
}
|
|
|
|
/*
|
|
* Check validity of the structure before insert.
|
|
* Fortunately rules are simple, so this mostly need to check rule sizes.
|
|
*/
|
|
static int
|
|
check_ipfw_struct(struct ip_fw *rule, int size)
|
|
{
|
|
int l, cmdlen = 0;
|
|
int have_action=0;
|
|
ipfw_insn *cmd;
|
|
|
|
if (size < sizeof(*rule)) {
|
|
printf("ipfw: rule too short\n");
|
|
return (EINVAL);
|
|
}
|
|
/* first, check for valid size */
|
|
l = RULESIZE(rule);
|
|
if (l != size) {
|
|
printf("ipfw: size mismatch (have %d want %d)\n", size, l);
|
|
return (EINVAL);
|
|
}
|
|
/*
|
|
* Now go for the individual checks. Very simple ones, basically only
|
|
* instruction sizes.
|
|
*/
|
|
for (l = rule->cmd_len, cmd = rule->cmd ;
|
|
l > 0 ; l -= cmdlen, cmd += cmdlen) {
|
|
cmdlen = F_LEN(cmd);
|
|
if (cmdlen > l) {
|
|
printf("ipfw: opcode %d size truncated\n",
|
|
cmd->opcode);
|
|
return EINVAL;
|
|
}
|
|
DEB(printf("ipfw: opcode %d\n", cmd->opcode);)
|
|
switch (cmd->opcode) {
|
|
case O_PROBE_STATE:
|
|
case O_KEEP_STATE:
|
|
case O_PROTO:
|
|
case O_IP_SRC_ME:
|
|
case O_IP_DST_ME:
|
|
case O_LAYER2:
|
|
case O_IN:
|
|
case O_FRAG:
|
|
case O_IPOPT:
|
|
case O_IPTOS:
|
|
case O_IPPRECEDENCE:
|
|
case O_IPVER:
|
|
case O_TCPWIN:
|
|
case O_TCPFLAGS:
|
|
case O_TCPOPTS:
|
|
case O_ESTAB:
|
|
case O_VERREVPATH:
|
|
case O_VERSRCREACH:
|
|
case O_ANTISPOOF:
|
|
case O_IPSEC:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn))
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_UID:
|
|
case O_GID:
|
|
case O_JAIL:
|
|
case O_IP_SRC:
|
|
case O_IP_DST:
|
|
case O_TCPSEQ:
|
|
case O_TCPACK:
|
|
case O_PROB:
|
|
case O_ICMPTYPE:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_u32))
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_LIMIT:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_limit))
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_LOG:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_log))
|
|
goto bad_size;
|
|
|
|
((ipfw_insn_log *)cmd)->log_left =
|
|
((ipfw_insn_log *)cmd)->max_log;
|
|
|
|
break;
|
|
|
|
case O_IP_SRC_MASK:
|
|
case O_IP_DST_MASK:
|
|
/* only odd command lengths */
|
|
if ( !(cmdlen & 1) || cmdlen > 31)
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_IP_SRC_SET:
|
|
case O_IP_DST_SET:
|
|
if (cmd->arg1 == 0 || cmd->arg1 > 256) {
|
|
printf("ipfw: invalid set size %d\n",
|
|
cmd->arg1);
|
|
return EINVAL;
|
|
}
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
|
|
(cmd->arg1+31)/32 )
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_IP_SRC_LOOKUP:
|
|
case O_IP_DST_LOOKUP:
|
|
if (cmd->arg1 >= IPFW_TABLES_MAX) {
|
|
printf("ipfw: invalid table number %d\n",
|
|
cmd->arg1);
|
|
return (EINVAL);
|
|
}
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn) &&
|
|
cmdlen != F_INSN_SIZE(ipfw_insn_u32))
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_MACADDR2:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_mac))
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_NOP:
|
|
case O_IPID:
|
|
case O_IPTTL:
|
|
case O_IPLEN:
|
|
if (cmdlen < 1 || cmdlen > 31)
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_MAC_TYPE:
|
|
case O_IP_SRCPORT:
|
|
case O_IP_DSTPORT: /* XXX artificial limit, 30 port pairs */
|
|
if (cmdlen < 2 || cmdlen > 31)
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_RECV:
|
|
case O_XMIT:
|
|
case O_VIA:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_if))
|
|
goto bad_size;
|
|
break;
|
|
|
|
case O_PIPE:
|
|
case O_QUEUE:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_pipe))
|
|
goto bad_size;
|
|
goto check_action;
|
|
|
|
case O_FORWARD_IP:
|
|
#ifdef IPFIREWALL_FORWARD
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
|
|
goto bad_size;
|
|
goto check_action;
|
|
#else
|
|
return EINVAL;
|
|
#endif
|
|
|
|
case O_DIVERT:
|
|
case O_TEE:
|
|
#ifndef IPDIVERT
|
|
return EINVAL;
|
|
#endif
|
|
case O_FORWARD_MAC: /* XXX not implemented yet */
|
|
case O_CHECK_STATE:
|
|
case O_COUNT:
|
|
case O_ACCEPT:
|
|
case O_DENY:
|
|
case O_REJECT:
|
|
case O_SKIPTO:
|
|
if (cmdlen != F_INSN_SIZE(ipfw_insn))
|
|
goto bad_size;
|
|
check_action:
|
|
if (have_action) {
|
|
printf("ipfw: opcode %d, multiple actions"
|
|
" not allowed\n",
|
|
cmd->opcode);
|
|
return EINVAL;
|
|
}
|
|
have_action = 1;
|
|
if (l != cmdlen) {
|
|
printf("ipfw: opcode %d, action must be"
|
|
" last opcode\n",
|
|
cmd->opcode);
|
|
return EINVAL;
|
|
}
|
|
break;
|
|
default:
|
|
printf("ipfw: opcode %d, unknown opcode\n",
|
|
cmd->opcode);
|
|
return EINVAL;
|
|
}
|
|
}
|
|
if (have_action == 0) {
|
|
printf("ipfw: missing action\n");
|
|
return EINVAL;
|
|
}
|
|
return 0;
|
|
|
|
bad_size:
|
|
printf("ipfw: opcode %d size %d wrong\n",
|
|
cmd->opcode, cmdlen);
|
|
return EINVAL;
|
|
}
|
|
|
|
/*
|
|
* Copy the static and dynamic rules to the supplied buffer
|
|
* and return the amount of space actually used.
|
|
*/
|
|
static size_t
|
|
ipfw_getrules(struct ip_fw_chain *chain, void *buf, size_t space)
|
|
{
|
|
char *bp = buf;
|
|
char *ep = bp + space;
|
|
struct ip_fw *rule;
|
|
int i;
|
|
|
|
/* XXX this can take a long time and locking will block packet flow */
|
|
IPFW_LOCK(chain);
|
|
for (rule = chain->rules; rule ; rule = rule->next) {
|
|
/*
|
|
* Verify the entry fits in the buffer in case the
|
|
* rules changed between calculating buffer space and
|
|
* now. This would be better done using a generation
|
|
* number but should suffice for now.
|
|
*/
|
|
i = RULESIZE(rule);
|
|
if (bp + i <= ep) {
|
|
bcopy(rule, bp, i);
|
|
bcopy(&set_disable, &(((struct ip_fw *)bp)->next_rule),
|
|
sizeof(set_disable));
|
|
bp += i;
|
|
}
|
|
}
|
|
IPFW_UNLOCK(chain);
|
|
if (ipfw_dyn_v) {
|
|
ipfw_dyn_rule *p, *last = NULL;
|
|
|
|
IPFW_DYN_LOCK();
|
|
for (i = 0 ; i < curr_dyn_buckets; i++)
|
|
for (p = ipfw_dyn_v[i] ; p != NULL; p = p->next) {
|
|
if (bp + sizeof *p <= ep) {
|
|
ipfw_dyn_rule *dst =
|
|
(ipfw_dyn_rule *)bp;
|
|
bcopy(p, dst, sizeof *p);
|
|
bcopy(&(p->rule->rulenum), &(dst->rule),
|
|
sizeof(p->rule->rulenum));
|
|
/*
|
|
* store a non-null value in "next".
|
|
* The userland code will interpret a
|
|
* NULL here as a marker
|
|
* for the last dynamic rule.
|
|
*/
|
|
bcopy(&dst, &dst->next, sizeof(dst));
|
|
last = dst;
|
|
dst->expire =
|
|
TIME_LEQ(dst->expire, time_second) ?
|
|
0 : dst->expire - time_second ;
|
|
bp += sizeof(ipfw_dyn_rule);
|
|
}
|
|
}
|
|
IPFW_DYN_UNLOCK();
|
|
if (last != NULL) /* mark last dynamic rule */
|
|
bzero(&last->next, sizeof(last));
|
|
}
|
|
return (bp - (char *)buf);
|
|
}
|
|
|
|
|
|
/**
|
|
* {set|get}sockopt parser.
|
|
*/
|
|
static int
|
|
ipfw_ctl(struct sockopt *sopt)
|
|
{
|
|
#define RULE_MAXSIZE (256*sizeof(u_int32_t))
|
|
int error, rule_num;
|
|
size_t size;
|
|
struct ip_fw *buf, *rule;
|
|
u_int32_t rulenum[2];
|
|
|
|
error = suser(sopt->sopt_td);
|
|
if (error)
|
|
return (error);
|
|
|
|
/*
|
|
* Disallow modifications in really-really secure mode, but still allow
|
|
* the logging counters to be reset.
|
|
*/
|
|
if (sopt->sopt_name == IP_FW_ADD ||
|
|
(sopt->sopt_dir == SOPT_SET && sopt->sopt_name != IP_FW_RESETLOG)) {
|
|
#if __FreeBSD_version >= 500034
|
|
error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
|
|
if (error)
|
|
return (error);
|
|
#else /* FreeBSD 4.x */
|
|
if (securelevel >= 3)
|
|
return (EPERM);
|
|
#endif
|
|
}
|
|
|
|
error = 0;
|
|
|
|
switch (sopt->sopt_name) {
|
|
case IP_FW_GET:
|
|
/*
|
|
* pass up a copy of the current rules. Static rules
|
|
* come first (the last of which has number IPFW_DEFAULT_RULE),
|
|
* followed by a possibly empty list of dynamic rule.
|
|
* The last dynamic rule has NULL in the "next" field.
|
|
*
|
|
* Note that the calculated size is used to bound the
|
|
* amount of data returned to the user. The rule set may
|
|
* change between calculating the size and returning the
|
|
* data in which case we'll just return what fits.
|
|
*/
|
|
size = static_len; /* size of static rules */
|
|
if (ipfw_dyn_v) /* add size of dyn.rules */
|
|
size += (dyn_count * sizeof(ipfw_dyn_rule));
|
|
|
|
/*
|
|
* XXX todo: if the user passes a short length just to know
|
|
* how much room is needed, do not bother filling up the
|
|
* buffer, just jump to the sooptcopyout.
|
|
*/
|
|
buf = malloc(size, M_TEMP, M_WAITOK);
|
|
error = sooptcopyout(sopt, buf,
|
|
ipfw_getrules(&layer3_chain, buf, size));
|
|
free(buf, M_TEMP);
|
|
break;
|
|
|
|
case IP_FW_FLUSH:
|
|
/*
|
|
* Normally we cannot release the lock on each iteration.
|
|
* We could do it here only because we start from the head all
|
|
* the times so there is no risk of missing some entries.
|
|
* On the other hand, the risk is that we end up with
|
|
* a very inconsistent ruleset, so better keep the lock
|
|
* around the whole cycle.
|
|
*
|
|
* XXX this code can be improved by resetting the head of
|
|
* the list to point to the default rule, and then freeing
|
|
* the old list without the need for a lock.
|
|
*/
|
|
|
|
IPFW_LOCK(&layer3_chain);
|
|
layer3_chain.reap = NULL;
|
|
free_chain(&layer3_chain, 0 /* keep default rule */);
|
|
rule = layer3_chain.reap, layer3_chain.reap = NULL;
|
|
IPFW_UNLOCK(&layer3_chain);
|
|
if (layer3_chain.reap != NULL)
|
|
reap_rules(rule);
|
|
break;
|
|
|
|
case IP_FW_ADD:
|
|
rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK);
|
|
error = sooptcopyin(sopt, rule, RULE_MAXSIZE,
|
|
sizeof(struct ip_fw) );
|
|
if (error == 0)
|
|
error = check_ipfw_struct(rule, sopt->sopt_valsize);
|
|
if (error == 0) {
|
|
error = add_rule(&layer3_chain, rule);
|
|
size = RULESIZE(rule);
|
|
if (!error && sopt->sopt_dir == SOPT_GET)
|
|
error = sooptcopyout(sopt, rule, size);
|
|
}
|
|
free(rule, M_TEMP);
|
|
break;
|
|
|
|
case IP_FW_DEL:
|
|
/*
|
|
* IP_FW_DEL is used for deleting single rules or sets,
|
|
* and (ab)used to atomically manipulate sets. Argument size
|
|
* is used to distinguish between the two:
|
|
* sizeof(u_int32_t)
|
|
* delete single rule or set of rules,
|
|
* or reassign rules (or sets) to a different set.
|
|
* 2*sizeof(u_int32_t)
|
|
* atomic disable/enable sets.
|
|
* first u_int32_t contains sets to be disabled,
|
|
* second u_int32_t contains sets to be enabled.
|
|
*/
|
|
error = sooptcopyin(sopt, rulenum,
|
|
2*sizeof(u_int32_t), sizeof(u_int32_t));
|
|
if (error)
|
|
break;
|
|
size = sopt->sopt_valsize;
|
|
if (size == sizeof(u_int32_t)) /* delete or reassign */
|
|
error = del_entry(&layer3_chain, rulenum[0]);
|
|
else if (size == 2*sizeof(u_int32_t)) /* set enable/disable */
|
|
set_disable =
|
|
(set_disable | rulenum[0]) & ~rulenum[1] &
|
|
~(1<<RESVD_SET); /* set RESVD_SET always enabled */
|
|
else
|
|
error = EINVAL;
|
|
break;
|
|
|
|
case IP_FW_ZERO:
|
|
case IP_FW_RESETLOG: /* argument is an int, the rule number */
|
|
rule_num = 0;
|
|
if (sopt->sopt_val != 0) {
|
|
error = sooptcopyin(sopt, &rule_num,
|
|
sizeof(int), sizeof(int));
|
|
if (error)
|
|
break;
|
|
}
|
|
error = zero_entry(&layer3_chain, rule_num,
|
|
sopt->sopt_name == IP_FW_RESETLOG);
|
|
break;
|
|
|
|
case IP_FW_TABLE_ADD:
|
|
{
|
|
ipfw_table_entry ent;
|
|
|
|
error = sooptcopyin(sopt, &ent,
|
|
sizeof(ent), sizeof(ent));
|
|
if (error)
|
|
break;
|
|
error = add_table_entry(ent.tbl, ent.addr,
|
|
ent.masklen, ent.value);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_TABLE_DEL:
|
|
{
|
|
ipfw_table_entry ent;
|
|
|
|
error = sooptcopyin(sopt, &ent,
|
|
sizeof(ent), sizeof(ent));
|
|
if (error)
|
|
break;
|
|
error = del_table_entry(ent.tbl, ent.addr, ent.masklen);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_TABLE_FLUSH:
|
|
{
|
|
u_int16_t tbl;
|
|
|
|
error = sooptcopyin(sopt, &tbl,
|
|
sizeof(tbl), sizeof(tbl));
|
|
if (error)
|
|
break;
|
|
error = flush_table(tbl);
|
|
}
|
|
break;
|
|
|
|
case IP_FW_TABLE_GETSIZE:
|
|
{
|
|
u_int32_t tbl, cnt;
|
|
|
|
if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl),
|
|
sizeof(tbl))))
|
|
break;
|
|
if ((error = count_table(tbl, &cnt)))
|
|
break;
|
|
error = sooptcopyout(sopt, &cnt, sizeof(cnt));
|
|
}
|
|
break;
|
|
|
|
case IP_FW_TABLE_LIST:
|
|
{
|
|
ipfw_table *tbl;
|
|
|
|
if (sopt->sopt_valsize < sizeof(*tbl)) {
|
|
error = EINVAL;
|
|
break;
|
|
}
|
|
size = sopt->sopt_valsize;
|
|
tbl = malloc(size, M_TEMP, M_WAITOK);
|
|
if (tbl == NULL) {
|
|
error = ENOMEM;
|
|
break;
|
|
}
|
|
error = sooptcopyin(sopt, tbl, size, sizeof(*tbl));
|
|
if (error) {
|
|
free(tbl, M_TEMP);
|
|
break;
|
|
}
|
|
tbl->size = (size - sizeof(*tbl)) /
|
|
sizeof(ipfw_table_entry);
|
|
error = dump_table(tbl);
|
|
if (error) {
|
|
free(tbl, M_TEMP);
|
|
break;
|
|
}
|
|
error = sooptcopyout(sopt, tbl, size);
|
|
free(tbl, M_TEMP);
|
|
}
|
|
break;
|
|
|
|
default:
|
|
printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name);
|
|
error = EINVAL;
|
|
}
|
|
|
|
return (error);
|
|
#undef RULE_MAXSIZE
|
|
}
|
|
|
|
/**
|
|
* dummynet needs a reference to the default rule, because rules can be
|
|
* deleted while packets hold a reference to them. When this happens,
|
|
* dummynet changes the reference to the default rule (it could well be a
|
|
* NULL pointer, but this way we do not need to check for the special
|
|
* case, plus here he have info on the default behaviour).
|
|
*/
|
|
struct ip_fw *ip_fw_default_rule;
|
|
|
|
/*
|
|
* This procedure is only used to handle keepalives. It is invoked
|
|
* every dyn_keepalive_period
|
|
*/
|
|
static void
|
|
ipfw_tick(void * __unused unused)
|
|
{
|
|
int i;
|
|
ipfw_dyn_rule *q;
|
|
|
|
if (dyn_keepalive == 0 || ipfw_dyn_v == NULL || dyn_count == 0)
|
|
goto done;
|
|
|
|
IPFW_DYN_LOCK();
|
|
for (i = 0 ; i < curr_dyn_buckets ; i++) {
|
|
for (q = ipfw_dyn_v[i] ; q ; q = q->next ) {
|
|
if (q->dyn_type == O_LIMIT_PARENT)
|
|
continue;
|
|
if (q->id.proto != IPPROTO_TCP)
|
|
continue;
|
|
if ( (q->state & BOTH_SYN) != BOTH_SYN)
|
|
continue;
|
|
if (TIME_LEQ( time_second+dyn_keepalive_interval,
|
|
q->expire))
|
|
continue; /* too early */
|
|
if (TIME_LEQ(q->expire, time_second))
|
|
continue; /* too late, rule expired */
|
|
|
|
send_pkt(&(q->id), q->ack_rev - 1, q->ack_fwd, TH_SYN);
|
|
send_pkt(&(q->id), q->ack_fwd - 1, q->ack_rev, 0);
|
|
}
|
|
}
|
|
IPFW_DYN_UNLOCK();
|
|
done:
|
|
callout_reset(&ipfw_timeout, dyn_keepalive_period*hz, ipfw_tick, NULL);
|
|
}
|
|
|
|
int
|
|
ipfw_init(void)
|
|
{
|
|
struct ip_fw default_rule;
|
|
int error;
|
|
|
|
layer3_chain.rules = NULL;
|
|
IPFW_LOCK_INIT(&layer3_chain);
|
|
IPFW_DYN_LOCK_INIT();
|
|
callout_init(&ipfw_timeout, debug_mpsafenet ? CALLOUT_MPSAFE : 0);
|
|
|
|
bzero(&default_rule, sizeof default_rule);
|
|
|
|
default_rule.act_ofs = 0;
|
|
default_rule.rulenum = IPFW_DEFAULT_RULE;
|
|
default_rule.cmd_len = 1;
|
|
default_rule.set = RESVD_SET;
|
|
|
|
default_rule.cmd[0].len = 1;
|
|
default_rule.cmd[0].opcode =
|
|
#ifdef IPFIREWALL_DEFAULT_TO_ACCEPT
|
|
1 ? O_ACCEPT :
|
|
#endif
|
|
O_DENY;
|
|
|
|
error = add_rule(&layer3_chain, &default_rule);
|
|
if (error != 0) {
|
|
printf("ipfw2: error %u initializing default rule "
|
|
"(support disabled)\n", error);
|
|
IPFW_DYN_LOCK_DESTROY();
|
|
IPFW_LOCK_DESTROY(&layer3_chain);
|
|
return (error);
|
|
}
|
|
|
|
ip_fw_default_rule = layer3_chain.rules;
|
|
printf("ipfw2 initialized, divert %s, "
|
|
"rule-based forwarding "
|
|
#ifdef IPFIREWALL_FORWARD
|
|
"enabled, "
|
|
#else
|
|
"disabled, "
|
|
#endif
|
|
"default to %s, logging ",
|
|
#ifdef IPDIVERT
|
|
"enabled",
|
|
#else
|
|
"disabled",
|
|
#endif
|
|
default_rule.cmd[0].opcode == O_ACCEPT ? "accept" : "deny");
|
|
|
|
#ifdef IPFIREWALL_VERBOSE
|
|
fw_verbose = 1;
|
|
#endif
|
|
#ifdef IPFIREWALL_VERBOSE_LIMIT
|
|
verbose_limit = IPFIREWALL_VERBOSE_LIMIT;
|
|
#endif
|
|
if (fw_verbose == 0)
|
|
printf("disabled\n");
|
|
else if (verbose_limit == 0)
|
|
printf("unlimited\n");
|
|
else
|
|
printf("limited to %d packets/entry by default\n",
|
|
verbose_limit);
|
|
|
|
init_tables();
|
|
ip_fw_ctl_ptr = ipfw_ctl;
|
|
ip_fw_chk_ptr = ipfw_chk;
|
|
callout_reset(&ipfw_timeout, hz, ipfw_tick, NULL);
|
|
|
|
return (0);
|
|
}
|
|
|
|
void
|
|
ipfw_destroy(void)
|
|
{
|
|
struct ip_fw *reap;
|
|
|
|
ip_fw_chk_ptr = NULL;
|
|
ip_fw_ctl_ptr = NULL;
|
|
callout_drain(&ipfw_timeout);
|
|
IPFW_LOCK(&layer3_chain);
|
|
layer3_chain.reap = NULL;
|
|
free_chain(&layer3_chain, 1 /* kill default rule */);
|
|
reap = layer3_chain.reap, layer3_chain.reap = NULL;
|
|
IPFW_UNLOCK(&layer3_chain);
|
|
if (reap != NULL)
|
|
reap_rules(reap);
|
|
flush_tables();
|
|
IPFW_DYN_LOCK_DESTROY();
|
|
IPFW_LOCK_DESTROY(&layer3_chain);
|
|
printf("IP firewall unloaded\n");
|
|
}
|
|
|
|
#endif /* IPFW2 */
|