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freebsd-skq/sys/netpfil/ipfw/ip_fw_log.c
Gleb Smirnoff f355cb3e6f PFIL_MEMPTR for ipfw link level hook 
With new pfil(9) KPI it is possible to pass a void pointer with length
instead of mbuf pointer to a packet filter. Until this commit no filters
supported that, so pfil run through a shim function pfil_fake_mbuf().

Now the ipfw(4) hook named "default-link", that is instantiated when
net.link.ether.ipfw sysctl is on, supports processing pointer/length
packets natively.

- ip_fw_args now has union for either mbuf or void *, and if flags have
  non-zero length, then we use the void *.
- through ipfw_chk() we handle mem/mbuf cases differently.
- ether_header goes away from args. It is ipfw_chk() responsibility
  to do parsing of Ethernet header.
- ipfw_log() now uses different bpf APIs to log packets.

Although ipfw_chk() is now capable to process pointer/length packets,
this commit adds support for the link level hook only, see
ipfw_check_frame(). Potentially the IP processing hook ipfw_check_packet()
can be improved too, but that requires more changes since the hook
supports more complex actions: NAT, divert, etc.

Reviewed by:	ae
Differential Revision:	https://reviews.freebsd.org/D19357
2019-03-14 22:52:16 +00:00

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/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2002-2009 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
/*
* Logging support for ipfw
*/
#include "opt_ipfw.h"
#include "opt_inet.h"
#ifndef INET
#error IPFIREWALL requires INET.
#endif /* INET */
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <net/ethernet.h> /* for ETHERTYPE_IP */
#include <net/if.h>
#include <net/if_var.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip.h>
#include <netinet/ip_icmp.h>
#include <netinet/ip_var.h>
#include <netinet/ip_fw.h>
#include <netinet/tcp_var.h>
#include <netinet/udp.h>
#include <netinet/ip6.h>
#include <netinet/icmp6.h>
#ifdef INET6
#include <netinet6/in6_var.h> /* ip6_sprintf() */
#endif
#include <netpfil/ipfw/ip_fw_private.h>
#ifdef MAC
#include <security/mac/mac_framework.h>
#endif
/*
* L3HDR maps an ipv4 pointer into a layer3 header pointer of type T
* Other macros just cast void * into the appropriate type
*/
#define L3HDR(T, ip) ((T *)((u_int32_t *)(ip) + (ip)->ip_hl))
#define TCP(p) ((struct tcphdr *)(p))
#define SCTP(p) ((struct sctphdr *)(p))
#define UDP(p) ((struct udphdr *)(p))
#define ICMP(p) ((struct icmphdr *)(p))
#define ICMP6(p) ((struct icmp6_hdr *)(p))
#ifdef __APPLE__
#undef snprintf
#define snprintf sprintf
#define SNPARGS(buf, len) buf + len
#define SNP(buf) buf
#else /* !__APPLE__ */
#define SNPARGS(buf, len) buf + len, sizeof(buf) > len ? sizeof(buf) - len : 0
#define SNP(buf) buf, sizeof(buf)
#endif /* !__APPLE__ */
#define TARG(k, f) IP_FW_ARG_TABLEARG(chain, k, f)
/*
* We enter here when we have a rule with O_LOG.
* XXX this function alone takes about 2Kbytes of code!
*/
void
ipfw_log(struct ip_fw_chain *chain, struct ip_fw *f, u_int hlen,
struct ip_fw_args *args, u_short offset, uint32_t tablearg, struct ip *ip)
{
char *action;
int limit_reached = 0;
char action2[92], proto[128], fragment[32];
if (V_fw_verbose == 0) {
if (args->flags & IPFW_ARGS_LENMASK)
ipfw_bpf_tap(args->mem, IPFW_ARGS_LENGTH(args->flags));
else if (args->flags & IPFW_ARGS_ETHER)
/* layer2, use orig hdr */
ipfw_bpf_mtap(args->m);
else {
/* Add fake header. Later we will store
* more info in the header.
*/
if (ip->ip_v == 4)
ipfw_bpf_mtap2("DDDDDDSSSSSS\x08\x00",
ETHER_HDR_LEN, args->m);
else if (ip->ip_v == 6)
ipfw_bpf_mtap2("DDDDDDSSSSSS\x86\xdd",
ETHER_HDR_LEN, args->m);
else
/* Obviously bogus EtherType. */
ipfw_bpf_mtap2("DDDDDDSSSSSS\xff\xff",
ETHER_HDR_LEN, args->m);
}
return;
}
/* the old 'log' function */
fragment[0] = '\0';
proto[0] = '\0';
if (f == NULL) { /* bogus pkt */
if (V_verbose_limit != 0 && V_norule_counter >= V_verbose_limit)
return;
V_norule_counter++;
if (V_norule_counter == V_verbose_limit)
limit_reached = V_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_ALTQ) {
ipfw_insn_altq *altq = (ipfw_insn_altq *)cmd;
snprintf(SNPARGS(action2, 0), "Altq %d",
altq->qid);
cmd += F_LEN(cmd);
}
if (cmd->opcode == O_PROB || cmd->opcode == O_TAG ||
cmd->opcode == O_SETDSCP)
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_REJECT_ABORT)
action = "Abort";
else if (cmd->arg1==ICMP_UNREACH_HOST)
action = "Reject";
else
snprintf(SNPARGS(action2, 0), "Unreach %d",
cmd->arg1);
break;
case O_UNREACH6:
if (cmd->arg1==ICMP6_UNREACH_RST)
action = "Reset";
else if (cmd->arg1==ICMP6_UNREACH_ABORT)
action = "Abort";
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",
TARG(cmd->arg1, divert));
break;
case O_TEE:
snprintf(SNPARGS(action2, 0), "Tee %d",
TARG(cmd->arg1, divert));
break;
case O_SETFIB:
snprintf(SNPARGS(action2, 0), "SetFib %d",
TARG(cmd->arg1, fib) & 0x7FFF);
break;
case O_SKIPTO:
snprintf(SNPARGS(action2, 0), "SkipTo %d",
TARG(cmd->arg1, skipto));
break;
case O_PIPE:
snprintf(SNPARGS(action2, 0), "Pipe %d",
TARG(cmd->arg1, pipe));
break;
case O_QUEUE:
snprintf(SNPARGS(action2, 0), "Queue %d",
TARG(cmd->arg1, pipe));
break;
case O_FORWARD_IP: {
char buf[INET_ADDRSTRLEN];
ipfw_insn_sa *sa = (ipfw_insn_sa *)cmd;
int len;
struct in_addr dummyaddr;
if (sa->sa.sin_addr.s_addr == INADDR_ANY)
dummyaddr.s_addr = htonl(tablearg);
else
dummyaddr.s_addr = sa->sa.sin_addr.s_addr;
len = snprintf(SNPARGS(action2, 0), "Forward to %s",
inet_ntoa_r(dummyaddr, buf));
if (sa->sa.sin_port)
snprintf(SNPARGS(action2, len), ":%d",
sa->sa.sin_port);
}
break;
#ifdef INET6
case O_FORWARD_IP6: {
char buf[INET6_ADDRSTRLEN];
ipfw_insn_sa6 *sa = (ipfw_insn_sa6 *)cmd;
int len;
len = snprintf(SNPARGS(action2, 0), "Forward to [%s]",
ip6_sprintf(buf, &sa->sa.sin6_addr));
if (sa->sa.sin6_port)
snprintf(SNPARGS(action2, len), ":%u",
sa->sa.sin6_port);
}
break;
#endif
case O_NETGRAPH:
snprintf(SNPARGS(action2, 0), "Netgraph %d",
cmd->arg1);
break;
case O_NGTEE:
snprintf(SNPARGS(action2, 0), "Ngtee %d",
cmd->arg1);
break;
case O_NAT:
action = "Nat";
break;
case O_REASS:
action = "Reass";
break;
case O_CALLRETURN:
if (cmd->len & F_NOT)
action = "Return";
else
snprintf(SNPARGS(action2, 0), "Call %d",
cmd->arg1);
break;
case O_EXTERNAL_ACTION:
snprintf(SNPARGS(action2, 0), "Eaction %s",
((struct named_object *)SRV_OBJECT(chain,
cmd->arg1))->name);
break;
default:
action = "UNKNOWN";
break;
}
}
if (hlen == 0) { /* non-ip */
snprintf(SNPARGS(proto, 0), "MAC");
} else {
int len;
#ifdef INET6
char src[INET6_ADDRSTRLEN + 2], dst[INET6_ADDRSTRLEN + 2];
#else
char src[INET_ADDRSTRLEN], dst[INET_ADDRSTRLEN];
#endif
struct icmphdr *icmp;
struct tcphdr *tcp;
struct udphdr *udp;
#ifdef INET6
struct ip6_hdr *ip6 = NULL;
struct icmp6_hdr *icmp6;
u_short ip6f_mf;
#endif
src[0] = '\0';
dst[0] = '\0';
#ifdef INET6
ip6f_mf = offset & IP6F_MORE_FRAG;
offset &= IP6F_OFF_MASK;
if (IS_IP6_FLOW_ID(&(args->f_id))) {
char ip6buf[INET6_ADDRSTRLEN];
snprintf(src, sizeof(src), "[%s]",
ip6_sprintf(ip6buf, &args->f_id.src_ip6));
snprintf(dst, sizeof(dst), "[%s]",
ip6_sprintf(ip6buf, &args->f_id.dst_ip6));
ip6 = (struct ip6_hdr *)ip;
tcp = (struct tcphdr *)(((char *)ip) + hlen);
udp = (struct udphdr *)(((char *)ip) + hlen);
} else
#endif
{
tcp = L3HDR(struct tcphdr, ip);
udp = L3HDR(struct udphdr, ip);
inet_ntop(AF_INET, &ip->ip_src, src, sizeof(src));
inet_ntop(AF_INET, &ip->ip_dst, dst, sizeof(dst));
}
switch (args->f_id.proto) {
case IPPROTO_TCP:
len = snprintf(SNPARGS(proto, 0), "TCP %s", src);
if (offset == 0)
snprintf(SNPARGS(proto, len), ":%d %s:%d",
ntohs(tcp->th_sport),
dst,
ntohs(tcp->th_dport));
else
snprintf(SNPARGS(proto, len), " %s", dst);
break;
case IPPROTO_UDP:
case IPPROTO_UDPLITE:
len = snprintf(SNPARGS(proto, 0), "UDP%s%s",
args->f_id.proto == IPPROTO_UDP ? " ": "Lite ",
src);
if (offset == 0)
snprintf(SNPARGS(proto, len), ":%d %s:%d",
ntohs(udp->uh_sport),
dst,
ntohs(udp->uh_dport));
else
snprintf(SNPARGS(proto, len), " %s", dst);
break;
case IPPROTO_ICMP:
icmp = L3HDR(struct icmphdr, ip);
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", src);
snprintf(SNPARGS(proto, len), " %s", dst);
break;
#ifdef INET6
case IPPROTO_ICMPV6:
icmp6 = (struct icmp6_hdr *)(((char *)ip) + hlen);
if (offset == 0)
len = snprintf(SNPARGS(proto, 0),
"ICMPv6:%u.%u ",
icmp6->icmp6_type, icmp6->icmp6_code);
else
len = snprintf(SNPARGS(proto, 0), "ICMPv6 ");
len += snprintf(SNPARGS(proto, len), "%s", src);
snprintf(SNPARGS(proto, len), " %s", dst);
break;
#endif
default:
len = snprintf(SNPARGS(proto, 0), "P:%d %s",
args->f_id.proto, src);
snprintf(SNPARGS(proto, len), " %s", dst);
break;
}
#ifdef INET6
if (IS_IP6_FLOW_ID(&(args->f_id))) {
if (offset || ip6f_mf)
snprintf(SNPARGS(fragment, 0),
" (frag %08x:%d@%d%s)",
args->f_id.extra,
ntohs(ip6->ip6_plen) - hlen,
ntohs(offset) << 3, ip6f_mf ? "+" : "");
} else
#endif
{
int ipoff, iplen;
ipoff = ntohs(ip->ip_off);
iplen = ntohs(ip->ip_len);
if (ipoff & (IP_MF | IP_OFFMASK))
snprintf(SNPARGS(fragment, 0),
" (frag %d:%d@%d%s)",
ntohs(ip->ip_id), iplen - (ip->ip_hl << 2),
offset << 3,
(ipoff & IP_MF) ? "+" : "");
}
}
#ifdef __FreeBSD__
log(LOG_SECURITY | LOG_INFO, "ipfw: %d %s %s %s via %s%s\n",
f ? f->rulenum : -1, action, proto,
args->flags & IPFW_ARGS_OUT ? "out" : "in", args->ifp->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);
#endif
if (limit_reached)
log(LOG_SECURITY | LOG_NOTICE,
"ipfw: limit %d reached on entry %d\n",
limit_reached, f ? f->rulenum : -1);
}
/* end of file */
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