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freebsd-dev/sys/netpfil/ipfw/ip_fw_sockopt.c
Alexander V. Chernikov 4037b82802 Fix ipfw rule validation partially broken by r248552. 
Pointed by:	avg
MFC with:	r248552
2013-04-01 11:28:52 +00:00

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/*-
* Copyright (c) 2002-2009 Luigi Rizzo, Universita` di Pisa
*
* Supported by: Valeria Paoli
*
* 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("$FreeBSD$");
/*
* Sockopt support for ipfw. The routines here implement
* the upper half of the ipfw code.
*/
#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/malloc.h>
#include <sys/mbuf.h> /* struct m_tag used by nested headers */
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/sysctl.h>
#include <sys/syslog.h>
#include <net/if.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/ip_var.h> /* hooks */
#include <netinet/ip_fw.h>
#include <netpfil/ipfw/ip_fw_private.h>
#ifdef MAC
#include <security/mac/mac_framework.h>
#endif
MALLOC_DEFINE(M_IPFW, "IpFw/IpAcct", "IpFw/IpAcct chain's");
/*
* static variables followed by global ones (none in this file)
*/
/*
* Find the smallest rule >= key, id.
* We could use bsearch but it is so simple that we code it directly
*/
int
ipfw_find_rule(struct ip_fw_chain *chain, uint32_t key, uint32_t id)
{
int i, lo, hi;
struct ip_fw *r;
for (lo = 0, hi = chain->n_rules - 1; lo < hi;) {
i = (lo + hi) / 2;
r = chain->map[i];
if (r->rulenum < key)
lo = i + 1; /* continue from the next one */
else if (r->rulenum > key)
hi = i; /* this might be good */
else if (r->id < id)
lo = i + 1; /* continue from the next one */
else /* r->id >= id */
hi = i; /* this might be good */
};
return hi;
}
/*
* allocate a new map, returns the chain locked. extra is the number
* of entries to add or delete.
*/
static struct ip_fw **
get_map(struct ip_fw_chain *chain, int extra, int locked)
{
for (;;) {
struct ip_fw **map;
int i;
i = chain->n_rules + extra;
map = malloc(i * sizeof(struct ip_fw *), M_IPFW,
locked ? M_NOWAIT : M_WAITOK);
if (map == NULL) {
printf("%s: cannot allocate map\n", __FUNCTION__);
return NULL;
}
if (!locked)
IPFW_UH_WLOCK(chain);
if (i >= chain->n_rules + extra) /* good */
return map;
/* otherwise we lost the race, free and retry */
if (!locked)
IPFW_UH_WUNLOCK(chain);
free(map, M_IPFW);
}
}
/*
* swap the maps. It is supposed to be called with IPFW_UH_WLOCK
*/
static struct ip_fw **
swap_map(struct ip_fw_chain *chain, struct ip_fw **new_map, int new_len)
{
struct ip_fw **old_map;
IPFW_WLOCK(chain);
chain->id++;
chain->n_rules = new_len;
old_map = chain->map;
chain->map = new_map;
IPFW_WUNLOCK(chain);
return old_map;
}
/*
* 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.
* XXX DO NOT USE FOR THE DEFAULT RULE.
* Must be called without IPFW_UH held
*/
int
ipfw_add_rule(struct ip_fw_chain *chain, struct ip_fw *input_rule)
{
struct ip_fw *rule;
int i, l, insert_before;
struct ip_fw **map; /* the new array of pointers */
if (chain->rules == NULL || input_rule->rulenum > IPFW_DEFAULT_RULE-1)
return (EINVAL);
l = RULESIZE(input_rule);
rule = malloc(l, M_IPFW, M_WAITOK | M_ZERO);
/* get_map returns with IPFW_UH_WLOCK if successful */
map = get_map(chain, 1, 0 /* not locked */);
if (map == NULL) {
free(rule, M_IPFW);
return ENOSPC;
}
bcopy(input_rule, rule, l);
/* clear fields not settable from userland */
rule->x_next = NULL;
rule->next_rule = NULL;
IPFW_ZERO_RULE_COUNTER(rule);
if (V_autoinc_step < 1)
V_autoinc_step = 1;
else if (V_autoinc_step > 1000)
V_autoinc_step = 1000;
/* find the insertion point, we will insert before */
insert_before = rule->rulenum ? rule->rulenum + 1 : IPFW_DEFAULT_RULE;
i = ipfw_find_rule(chain, insert_before, 0);
/* duplicate first part */
if (i > 0)
bcopy(chain->map, map, i * sizeof(struct ip_fw *));
map[i] = rule;
/* duplicate remaining part, we always have the default rule */
bcopy(chain->map + i, map + i + 1,
sizeof(struct ip_fw *) *(chain->n_rules - i));
if (rule->rulenum == 0) {
/* write back the number */
rule->rulenum = i > 0 ? map[i-1]->rulenum : 0;
if (rule->rulenum < IPFW_DEFAULT_RULE - V_autoinc_step)
rule->rulenum += V_autoinc_step;
input_rule->rulenum = rule->rulenum;
}
rule->id = chain->id + 1;
map = swap_map(chain, map, chain->n_rules + 1);
chain->static_len += l;
IPFW_UH_WUNLOCK(chain);
if (map)
free(map, M_IPFW);
return (0);
}
/*
* Reclaim storage associated with a list of rules. This is
* typically the list created using remove_rule.
* A NULL pointer on input is handled correctly.
*/
void
ipfw_reap_rules(struct ip_fw *head)
{
struct ip_fw *rule;
while ((rule = head) != NULL) {
head = head->x_next;
free(rule, M_IPFW);
}
}
/*
* Used by del_entry() to check if a rule should be kept.
* Returns 1 if the rule must be kept, 0 otherwise.
*
* Called with cmd = {0,1,5}.
* cmd == 0 matches on rule numbers, excludes rules in RESVD_SET if n == 0 ;
* cmd == 1 matches on set numbers only, rule numbers are ignored;
* cmd == 5 matches on rule and set numbers.
*
* n == 0 is a wildcard for rule numbers, there is no wildcard for sets.
*
* Rules to keep are
* (default || reserved || !match_set || !match_number)
* where
* default ::= (rule->rulenum == IPFW_DEFAULT_RULE)
* // the default rule is always protected
*
* reserved ::= (cmd == 0 && n == 0 && rule->set == RESVD_SET)
* // RESVD_SET is protected only if cmd == 0 and n == 0 ("ipfw flush")
*
* match_set ::= (cmd == 0 || rule->set == set)
* // set number is ignored for cmd == 0
*
* match_number ::= (cmd == 1 || n == 0 || n == rule->rulenum)
* // number is ignored for cmd == 1 or n == 0
*
*/
static int
keep_rule(struct ip_fw *rule, uint8_t cmd, uint8_t set, uint32_t n)
{
return
(rule->rulenum == IPFW_DEFAULT_RULE) ||
(cmd == 0 && n == 0 && rule->set == RESVD_SET) ||
!(cmd == 0 || rule->set == set) ||
!(cmd == 1 || n == 0 || n == rule->rulenum);
}
/**
* Remove all rules with given number, or do set manipulation.
* Assumes chain != NULL && *chain != NULL.
*
* The argument is an uint32_t. The low 16 bit are the rule or set number;
* the next 8 bits are the new set; the top 8 bits indicate the command:
*
* 0 delete rules numbered "rulenum"
* 1 delete rules in set "rulenum"
* 2 move rules "rulenum" to set "new_set"
* 3 move rules from set "rulenum" to set "new_set"
* 4 swap sets "rulenum" and "new_set"
* 5 delete rules "rulenum" and set "new_set"
*/
static int
del_entry(struct ip_fw_chain *chain, uint32_t arg)
{
struct ip_fw *rule;
uint32_t num; /* rule number or old_set */
uint8_t cmd, new_set;
int start, end, i, ofs, n;
struct ip_fw **map = NULL;
int error = 0;
num = arg & 0xffff;
cmd = (arg >> 24) & 0xff;
new_set = (arg >> 16) & 0xff;
if (cmd > 5 || new_set > RESVD_SET)
return EINVAL;
if (cmd == 0 || cmd == 2 || cmd == 5) {
if (num >= IPFW_DEFAULT_RULE)
return EINVAL;
} else {
if (num > RESVD_SET) /* old_set */
return EINVAL;
}
IPFW_UH_WLOCK(chain); /* arbitrate writers */
chain->reap = NULL; /* prepare for deletions */
switch (cmd) {
case 0: /* delete rules "num" (num == 0 matches all) */
case 1: /* delete all rules in set N */
case 5: /* delete rules with number N and set "new_set". */
/*
* Locate first rule to delete (start), the rule after
* the last one to delete (end), and count how many
* rules to delete (n). Always use keep_rule() to
* determine which rules to keep.
*/
n = 0;
if (cmd == 1) {
/* look for a specific set including RESVD_SET.
* Must scan the entire range, ignore num.
*/
new_set = num;
for (start = -1, end = i = 0; i < chain->n_rules; i++) {
if (keep_rule(chain->map[i], cmd, new_set, 0))
continue;
if (start < 0)
start = i;
end = i;
n++;
}
end++; /* first non-matching */
} else {
/* Optimized search on rule numbers */
start = ipfw_find_rule(chain, num, 0);
for (end = start; end < chain->n_rules; end++) {
rule = chain->map[end];
if (num > 0 && rule->rulenum != num)
break;
if (!keep_rule(rule, cmd, new_set, num))
n++;
}
}
if (n == 0) {
/* A flush request (arg == 0 or cmd == 1) on empty
* ruleset returns with no error. On the contrary,
* if there is no match on a specific request,
* we return EINVAL.
*/
if (arg != 0 && cmd != 1)
error = EINVAL;
break;
}
/* We have something to delete. Allocate the new map */
map = get_map(chain, -n, 1 /* locked */);
if (map == NULL) {
error = EINVAL;
break;
}
/* 1. bcopy the initial part of the map */
if (start > 0)
bcopy(chain->map, map, start * sizeof(struct ip_fw *));
/* 2. copy active rules between start and end */
for (i = ofs = start; i < end; i++) {
rule = chain->map[i];
if (keep_rule(rule, cmd, new_set, num))
map[ofs++] = rule;
}
/* 3. copy the final part of the map */
bcopy(chain->map + end, map + ofs,
(chain->n_rules - end) * sizeof(struct ip_fw *));
/* 4. swap the maps (under BH_LOCK) */
map = swap_map(chain, map, chain->n_rules - n);
/* 5. now remove the rules deleted from the old map */
if (cmd == 1)
ipfw_expire_dyn_rules(chain, NULL, new_set);
for (i = start; i < end; i++) {
rule = map[i];
if (keep_rule(rule, cmd, new_set, num))
continue;
chain->static_len -= RULESIZE(rule);
if (cmd != 1)
ipfw_expire_dyn_rules(chain, rule, RESVD_SET);
rule->x_next = chain->reap;
chain->reap = rule;
}
break;
/*
* In the next 3 cases the loop stops at (n_rules - 1)
* because the default rule is never eligible..
*/
case 2: /* move rules with given RULE number to new set */
for (i = 0; i < chain->n_rules - 1; i++) {
rule = chain->map[i];
if (rule->rulenum == num)
rule->set = new_set;
}
break;
case 3: /* move rules with given SET number to new set */
for (i = 0; i < chain->n_rules - 1; i++) {
rule = chain->map[i];
if (rule->set == num)
rule->set = new_set;
}
break;
case 4: /* swap two sets */
for (i = 0; i < chain->n_rules - 1; i++) {
rule = chain->map[i];
if (rule->set == num)
rule->set = new_set;
else if (rule->set == new_set)
rule->set = num;
}
break;
}
rule = chain->reap;
chain->reap = NULL;
IPFW_UH_WUNLOCK(chain);
ipfw_reap_rules(rule);
if (map)
free(map, M_IPFW);
return error;
}
/*
* Clear counters for a specific rule.
* Normally run under IPFW_UH_RLOCK, but these are idempotent ops
* so we only care that rules do not disappear.
*/
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)
IPFW_ZERO_RULE_COUNTER(rule);
if (l->o.opcode == O_LOG)
l->log_left = l->max_log;
}
/**
* Reset some or all counters on firewall rules.
* The argument `arg' is an u_int32_t. The low 16 bit are the rule number,
* the next 8 bits are the set number, the top 8 bits are the command:
* 0 work with rules from all set's;
* 1 work with rules only from specified set.
* Specified rule number is zero if we want to clear all entries.
* log_only is 1 if we only want to reset logs, zero otherwise.
*/
static int
zero_entry(struct ip_fw_chain *chain, u_int32_t arg, int log_only)
{
struct ip_fw *rule;
char *msg;
int i;
uint16_t rulenum = arg & 0xffff;
uint8_t set = (arg >> 16) & 0xff;
uint8_t cmd = (arg >> 24) & 0xff;
if (cmd > 1)
return (EINVAL);
if (cmd == 1 && set > RESVD_SET)
return (EINVAL);
IPFW_UH_RLOCK(chain);
if (rulenum == 0) {
V_norule_counter = 0;
for (i = 0; i < chain->n_rules; i++) {
rule = chain->map[i];
/* Skip rules not in our set. */
if (cmd == 1 && rule->set != set)
continue;
clear_counters(rule, log_only);
}
msg = log_only ? "All logging counts reset" :
"Accounting cleared";
} else {
int cleared = 0;
for (i = 0; i < chain->n_rules; i++) {
rule = chain->map[i];
if (rule->rulenum == rulenum) {
if (cmd == 0 || rule->set == set)
clear_counters(rule, log_only);
cleared = 1;
}
if (rule->rulenum > rulenum)
break;
}
if (!cleared) { /* we did not find any matching rules */
IPFW_UH_RUNLOCK(chain);
return (EINVAL);
}
msg = log_only ? "logging count reset" : "cleared";
}
IPFW_UH_RUNLOCK(chain);
if (V_fw_verbose) {
int lev = LOG_SECURITY | LOG_NOTICE;
if (rulenum)
log(lev, "ipfw: Entry %d %s.\n", rulenum, msg);
else
log(lev, "ipfw: %s.\n", msg);
}
return (0);
}
/*
* Check validity of the structure before insert.
* 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);
}
if (rule->act_ofs >= rule->cmd_len) {
printf("ipfw: bogus action offset (%u > %u)\n",
rule->act_ofs, rule->cmd_len - 1);
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;
}
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_DIVERTED:
case O_IPOPT:
case O_IPTOS:
case O_IPPRECEDENCE:
case O_IPVER:
case O_SOCKARG:
case O_TCPFLAGS:
case O_TCPOPTS:
case O_ESTAB:
case O_VERREVPATH:
case O_VERSRCREACH:
case O_ANTISPOOF:
case O_IPSEC:
#ifdef INET6
case O_IP6_SRC_ME:
case O_IP6_DST_ME:
case O_EXT_HDR:
case O_IP6:
#endif
case O_IP4:
case O_TAG:
if (cmdlen != F_INSN_SIZE(ipfw_insn))
goto bad_size;
break;
case O_FIB:
if (cmdlen != F_INSN_SIZE(ipfw_insn))
goto bad_size;
if (cmd->arg1 >= rt_numfibs) {
printf("ipfw: invalid fib number %d\n",
cmd->arg1);
return EINVAL;
}
break;
case O_SETFIB:
if (cmdlen != F_INSN_SIZE(ipfw_insn))
goto bad_size;
if ((cmd->arg1 != IP_FW_TABLEARG) &&
(cmd->arg1 >= rt_numfibs)) {
printf("ipfw: invalid fib number %d\n",
cmd->arg1);
return EINVAL;
}
goto check_action;
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) + 1 &&
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:
case O_TCPDATALEN:
case O_TCPWIN:
case O_TAGGED:
if (cmdlen < 1 || cmdlen > 31)
goto bad_size;
break;
case O_DSCP:
if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) + 1)
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_ALTQ:
if (cmdlen != F_INSN_SIZE(ipfw_insn_altq))
goto bad_size;
break;
case O_PIPE:
case O_QUEUE:
if (cmdlen != F_INSN_SIZE(ipfw_insn))
goto bad_size;
goto check_action;
case O_FORWARD_IP:
if (cmdlen != F_INSN_SIZE(ipfw_insn_sa))
goto bad_size;
goto check_action;
#ifdef INET6
case O_FORWARD_IP6:
if (cmdlen != F_INSN_SIZE(ipfw_insn_sa6))
goto bad_size;
goto check_action;
#endif /* INET6 */
case O_DIVERT:
case O_TEE:
if (ip_divert_ptr == NULL)
return EINVAL;
else
goto check_size;
case O_NETGRAPH:
case O_NGTEE:
if (ng_ipfw_input_p == NULL)
return EINVAL;
else
goto check_size;
case O_NAT:
if (!IPFW_NAT_LOADED)
return EINVAL;
if (cmdlen != F_INSN_SIZE(ipfw_insn_nat))
goto bad_size;
goto check_action;
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_SETDSCP:
#ifdef INET6
case O_UNREACH6:
#endif
case O_SKIPTO:
case O_REASS:
case O_CALLRETURN:
check_size:
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;
#ifdef INET6
case O_IP6_SRC:
case O_IP6_DST:
if (cmdlen != F_INSN_SIZE(struct in6_addr) +
F_INSN_SIZE(ipfw_insn))
goto bad_size;
break;
case O_FLOW6ID:
if (cmdlen != F_INSN_SIZE(ipfw_insn_u32) +
((ipfw_insn_u32 *)cmd)->o.arg1)
goto bad_size;
break;
case O_IP6_SRC_MASK:
case O_IP6_DST_MASK:
if ( !(cmdlen & 1) || cmdlen > 127)
goto bad_size;
break;
case O_ICMP6TYPE:
if( cmdlen != F_INSN_SIZE( ipfw_insn_icmp6 ) )
goto bad_size;
break;
#endif
default:
switch (cmd->opcode) {
#ifndef INET6
case O_IP6_SRC_ME:
case O_IP6_DST_ME:
case O_EXT_HDR:
case O_IP6:
case O_UNREACH6:
case O_IP6_SRC:
case O_IP6_DST:
case O_FLOW6ID:
case O_IP6_SRC_MASK:
case O_IP6_DST_MASK:
case O_ICMP6TYPE:
printf("ipfw: no IPv6 support in kernel\n");
return EPROTONOSUPPORT;
#endif
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;
}
/*
* Translation of requests for compatibility with FreeBSD 7.2/8.
* a static variable tells us if we have an old client from userland,
* and if necessary we translate requests and responses between the
* two formats.
*/
static int is7 = 0;
struct ip_fw7 {
struct ip_fw7 *next; /* linked list of rules */
struct ip_fw7 *next_rule; /* ptr to next [skipto] rule */
/* 'next_rule' is used to pass up 'set_disable' status */
uint16_t act_ofs; /* offset of action in 32-bit units */
uint16_t cmd_len; /* # of 32-bit words in cmd */
uint16_t rulenum; /* rule number */
uint8_t set; /* rule set (0..31) */
// #define RESVD_SET 31 /* set for default and persistent rules */
uint8_t _pad; /* padding */
// uint32_t id; /* rule id, only in v.8 */
/* These fields are present in all rules. */
uint64_t pcnt; /* Packet counter */
uint64_t bcnt; /* Byte counter */
uint32_t timestamp; /* tv_sec of last match */
ipfw_insn cmd[1]; /* storage for commands */
};
int convert_rule_to_7(struct ip_fw *rule);
int convert_rule_to_8(struct ip_fw *rule);
#ifndef RULESIZE7
#define RULESIZE7(rule) (sizeof(struct ip_fw7) + \
((struct ip_fw7 *)(rule))->cmd_len * 4 - 4)
#endif
/*
* Copy the static and dynamic rules to the supplied buffer
* and return the amount of space actually used.
* Must be run under IPFW_UH_RLOCK
*/
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, *dst;
int l, i;
time_t boot_seconds;
boot_seconds = boottime.tv_sec;
for (i = 0; i < chain->n_rules; i++) {
rule = chain->map[i];
if (is7) {
/* Convert rule to FreeBSd 7.2 format */
l = RULESIZE7(rule);
if (bp + l + sizeof(uint32_t) <= ep) {
int error;
bcopy(rule, bp, l + sizeof(uint32_t));
error = convert_rule_to_7((struct ip_fw *) bp);
if (error)
return 0; /*XXX correct? */
/*
* XXX HACK. Store the disable mask in the "next"
* pointer in a wild attempt to keep the ABI the same.
* Why do we do this on EVERY rule?
*/
bcopy(&V_set_disable,
&(((struct ip_fw7 *)bp)->next_rule),
sizeof(V_set_disable));
if (((struct ip_fw7 *)bp)->timestamp)
((struct ip_fw7 *)bp)->timestamp += boot_seconds;
bp += l;
}
continue; /* go to next rule */
}
/* normal mode, don't touch rules */
l = RULESIZE(rule);
if (bp + l > ep) { /* should not happen */
printf("overflow dumping static rules\n");
break;
}
dst = (struct ip_fw *)bp;
bcopy(rule, dst, l);
/*
* XXX HACK. Store the disable mask in the "next"
* pointer in a wild attempt to keep the ABI the same.
* Why do we do this on EVERY rule?
*/
bcopy(&V_set_disable, &dst->next_rule, sizeof(V_set_disable));
if (dst->timestamp)
dst->timestamp += boot_seconds;
bp += l;
}
ipfw_get_dynamic(chain, &bp, ep); /* protected by the dynamic lock */
return (bp - (char *)buf);
}
#define IP_FW3_OPLENGTH(x) ((x)->sopt_valsize - sizeof(ip_fw3_opheader))
/**
* {set|get}sockopt parser.
*/
int
ipfw_ctl(struct sockopt *sopt)
{
#define RULE_MAXSIZE (256*sizeof(u_int32_t))
int error;
size_t size, len, valsize;
struct ip_fw *buf, *rule;
struct ip_fw_chain *chain;
u_int32_t rulenum[2];
uint32_t opt;
char xbuf[128];
ip_fw3_opheader *op3 = NULL;
error = priv_check(sopt->sopt_td, PRIV_NETINET_IPFW);
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)) {
error = securelevel_ge(sopt->sopt_td->td_ucred, 3);
if (error)
return (error);
}
chain = &V_layer3_chain;
error = 0;
/* Save original valsize before it is altered via sooptcopyin() */
valsize = sopt->sopt_valsize;
if ((opt = sopt->sopt_name) == IP_FW3) {
/*
* Copy not less than sizeof(ip_fw3_opheader).
* We hope any IP_FW3 command will fit into 128-byte buffer.
*/
if ((error = sooptcopyin(sopt, xbuf, sizeof(xbuf),
sizeof(ip_fw3_opheader))) != 0)
return (error);
op3 = (ip_fw3_opheader *)xbuf;
opt = op3->opcode;
}
switch (opt) {
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.
*/
for (;;) {
int len = 0, want;
size = chain->static_len;
size += ipfw_dyn_len();
if (size >= sopt->sopt_valsize)
break;
buf = malloc(size, M_TEMP, M_WAITOK);
IPFW_UH_RLOCK(chain);
/* check again how much space we need */
want = chain->static_len + ipfw_dyn_len();
if (size >= want)
len = ipfw_getrules(chain, buf, size);
IPFW_UH_RUNLOCK(chain);
if (size >= want)
error = sooptcopyout(sopt, buf, len);
free(buf, M_TEMP);
if (size >= want)
break;
}
break;
case IP_FW_FLUSH:
/* locking is done within del_entry() */
error = del_entry(chain, 0); /* special case, rule=0, cmd=0 means all */
break;
case IP_FW_ADD:
rule = malloc(RULE_MAXSIZE, M_TEMP, M_WAITOK);
error = sooptcopyin(sopt, rule, RULE_MAXSIZE,
sizeof(struct ip_fw7) );
/*
* If the size of commands equals RULESIZE7 then we assume
* a FreeBSD7.2 binary is talking to us (set is7=1).
* is7 is persistent so the next 'ipfw list' command
* will use this format.
* NOTE: If wrong version is guessed (this can happen if
* the first ipfw command is 'ipfw [pipe] list')
* the ipfw binary may crash or loop infinitly...
*/
if (sopt->sopt_valsize == RULESIZE7(rule)) {
is7 = 1;
error = convert_rule_to_8(rule);
if (error)
return error;
if (error == 0)
error = check_ipfw_struct(rule, RULESIZE(rule));
} else {
is7 = 0;
if (error == 0)
error = check_ipfw_struct(rule, sopt->sopt_valsize);
}
if (error == 0) {
/* locking is done within ipfw_add_rule() */
error = ipfw_add_rule(chain, rule);
size = RULESIZE(rule);
if (!error && sopt->sopt_dir == SOPT_GET) {
if (is7) {
error = convert_rule_to_7(rule);
size = RULESIZE7(rule);
if (error)
return error;
}
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) && rulenum[0] != 0) {
/* delete or reassign, locking done in del_entry() */
error = del_entry(chain, rulenum[0]);
} else if (size == 2*sizeof(u_int32_t)) { /* set enable/disable */
IPFW_UH_WLOCK(chain);
V_set_disable =
(V_set_disable | rulenum[0]) & ~rulenum[1] &
~(1<<RESVD_SET); /* set RESVD_SET always enabled */
IPFW_UH_WUNLOCK(chain);
} else
error = EINVAL;
break;
case IP_FW_ZERO:
case IP_FW_RESETLOG: /* argument is an u_int_32, the rule number */
rulenum[0] = 0;
if (sopt->sopt_val != 0) {
error = sooptcopyin(sopt, rulenum,
sizeof(u_int32_t), sizeof(u_int32_t));
if (error)
break;
}
error = zero_entry(chain, rulenum[0],
sopt->sopt_name == IP_FW_RESETLOG);
break;
/*--- TABLE manipulations are protected by the IPFW_LOCK ---*/
case IP_FW_TABLE_ADD:
{
ipfw_table_entry ent;
error = sooptcopyin(sopt, &ent,
sizeof(ent), sizeof(ent));
if (error)
break;
error = ipfw_add_table_entry(chain, ent.tbl,
&ent.addr, sizeof(ent.addr), ent.masklen,
IPFW_TABLE_CIDR, ent.value);
}
break;
case IP_FW_TABLE_DEL:
{
ipfw_table_entry ent;
error = sooptcopyin(sopt, &ent,
sizeof(ent), sizeof(ent));
if (error)
break;
error = ipfw_del_table_entry(chain, ent.tbl,
&ent.addr, sizeof(ent.addr), ent.masklen, IPFW_TABLE_CIDR);
}
break;
case IP_FW_TABLE_XADD: /* IP_FW3 */
case IP_FW_TABLE_XDEL: /* IP_FW3 */
{
ipfw_table_xentry *xent = (ipfw_table_xentry *)(op3 + 1);
/* Check minimum header size */
if (IP_FW3_OPLENGTH(sopt) < offsetof(ipfw_table_xentry, k)) {
error = EINVAL;
break;
}
/* Check if len field is valid */
if (xent->len > sizeof(ipfw_table_xentry)) {
error = EINVAL;
break;
}
len = xent->len - offsetof(ipfw_table_xentry, k);
error = (opt == IP_FW_TABLE_XADD) ?
ipfw_add_table_entry(chain, xent->tbl, &xent->k,
len, xent->masklen, xent->type, xent->value) :
ipfw_del_table_entry(chain, xent->tbl, &xent->k,
len, xent->masklen, xent->type);
}
break;
case IP_FW_TABLE_FLUSH:
{
u_int16_t tbl;
error = sooptcopyin(sopt, &tbl,
sizeof(tbl), sizeof(tbl));
if (error)
break;
error = ipfw_flush_table(chain, tbl);
}
break;
case IP_FW_TABLE_GETSIZE:
{
u_int32_t tbl, cnt;
if ((error = sooptcopyin(sopt, &tbl, sizeof(tbl),
sizeof(tbl))))
break;
IPFW_RLOCK(chain);
error = ipfw_count_table(chain, tbl, &cnt);
IPFW_RUNLOCK(chain);
if (error)
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);
error = sooptcopyin(sopt, tbl, size, sizeof(*tbl));
if (error) {
free(tbl, M_TEMP);
break;
}
tbl->size = (size - sizeof(*tbl)) /
sizeof(ipfw_table_entry);
IPFW_RLOCK(chain);
error = ipfw_dump_table(chain, tbl);
IPFW_RUNLOCK(chain);
if (error) {
free(tbl, M_TEMP);
break;
}
error = sooptcopyout(sopt, tbl, size);
free(tbl, M_TEMP);
}
break;
case IP_FW_TABLE_XGETSIZE: /* IP_FW3 */
{
uint32_t *tbl;
if (IP_FW3_OPLENGTH(sopt) < sizeof(uint32_t)) {
error = EINVAL;
break;
}
tbl = (uint32_t *)(op3 + 1);
IPFW_RLOCK(chain);
error = ipfw_count_xtable(chain, *tbl, tbl);
IPFW_RUNLOCK(chain);
if (error)
break;
error = sooptcopyout(sopt, op3, sopt->sopt_valsize);
}
break;
case IP_FW_TABLE_XLIST: /* IP_FW3 */
{
ipfw_xtable *tbl;
if ((size = valsize) < sizeof(ipfw_xtable)) {
error = EINVAL;
break;
}
tbl = malloc(size, M_TEMP, M_ZERO | M_WAITOK);
memcpy(tbl, op3, sizeof(ipfw_xtable));
/* Get maximum number of entries we can store */
tbl->size = (size - sizeof(ipfw_xtable)) /
sizeof(ipfw_table_xentry);
IPFW_RLOCK(chain);
error = ipfw_dump_xtable(chain, tbl);
IPFW_RUNLOCK(chain);
if (error) {
free(tbl, M_TEMP);
break;
}
/* Revert size field back to bytes */
tbl->size = tbl->size * sizeof(ipfw_table_xentry) +
sizeof(ipfw_table);
/*
* Since we call sooptcopyin() with small buffer, sopt_valsize is
* decreased to reflect supplied buffer size. Set it back to original value
*/
sopt->sopt_valsize = valsize;
error = sooptcopyout(sopt, tbl, size);
free(tbl, M_TEMP);
}
break;
/*--- NAT operations are protected by the IPFW_LOCK ---*/
case IP_FW_NAT_CFG:
if (IPFW_NAT_LOADED)
error = ipfw_nat_cfg_ptr(sopt);
else {
printf("IP_FW_NAT_CFG: %s\n",
"ipfw_nat not present, please load it");
error = EINVAL;
}
break;
case IP_FW_NAT_DEL:
if (IPFW_NAT_LOADED)
error = ipfw_nat_del_ptr(sopt);
else {
printf("IP_FW_NAT_DEL: %s\n",
"ipfw_nat not present, please load it");
error = EINVAL;
}
break;
case IP_FW_NAT_GET_CONFIG:
if (IPFW_NAT_LOADED)
error = ipfw_nat_get_cfg_ptr(sopt);
else {
printf("IP_FW_NAT_GET_CFG: %s\n",
"ipfw_nat not present, please load it");
error = EINVAL;
}
break;
case IP_FW_NAT_GET_LOG:
if (IPFW_NAT_LOADED)
error = ipfw_nat_get_log_ptr(sopt);
else {
printf("IP_FW_NAT_GET_LOG: %s\n",
"ipfw_nat not present, please load it");
error = EINVAL;
}
break;
default:
printf("ipfw: ipfw_ctl invalid option %d\n", sopt->sopt_name);
error = EINVAL;
}
return (error);
#undef RULE_MAXSIZE
}
#define RULE_MAXSIZE (256*sizeof(u_int32_t))
/* Functions to convert rules 7.2 <==> 8.0 */
int
convert_rule_to_7(struct ip_fw *rule)
{
/* Used to modify original rule */
struct ip_fw7 *rule7 = (struct ip_fw7 *)rule;
/* copy of original rule, version 8 */
struct ip_fw *tmp;
/* Used to copy commands */
ipfw_insn *ccmd, *dst;
int ll = 0, ccmdlen = 0;
tmp = malloc(RULE_MAXSIZE, M_TEMP, M_NOWAIT | M_ZERO);
if (tmp == NULL) {
return 1; //XXX error
}
bcopy(rule, tmp, RULE_MAXSIZE);
/* Copy fields */
rule7->_pad = tmp->_pad;
rule7->set = tmp->set;
rule7->rulenum = tmp->rulenum;
rule7->cmd_len = tmp->cmd_len;
rule7->act_ofs = tmp->act_ofs;
rule7->next_rule = (struct ip_fw7 *)tmp->next_rule;
rule7->next = (struct ip_fw7 *)tmp->x_next;
rule7->cmd_len = tmp->cmd_len;
rule7->pcnt = tmp->pcnt;
rule7->bcnt = tmp->bcnt;
rule7->timestamp = tmp->timestamp;
/* Copy commands */
for (ll = tmp->cmd_len, ccmd = tmp->cmd, dst = rule7->cmd ;
ll > 0 ; ll -= ccmdlen, ccmd += ccmdlen, dst += ccmdlen) {
ccmdlen = F_LEN(ccmd);
bcopy(ccmd, dst, F_LEN(ccmd)*sizeof(uint32_t));
if (dst->opcode > O_NAT)
/* O_REASS doesn't exists in 7.2 version, so
* decrement opcode if it is after O_REASS
*/
dst->opcode--;
if (ccmdlen > ll) {
printf("ipfw: opcode %d size truncated\n",
ccmd->opcode);
return EINVAL;
}
}
free(tmp, M_TEMP);
return 0;
}
int
convert_rule_to_8(struct ip_fw *rule)
{
/* Used to modify original rule */
struct ip_fw7 *rule7 = (struct ip_fw7 *) rule;
/* Used to copy commands */
ipfw_insn *ccmd, *dst;
int ll = 0, ccmdlen = 0;
/* Copy of original rule */
struct ip_fw7 *tmp = malloc(RULE_MAXSIZE, M_TEMP, M_NOWAIT | M_ZERO);
if (tmp == NULL) {
return 1; //XXX error
}
bcopy(rule7, tmp, RULE_MAXSIZE);
for (ll = tmp->cmd_len, ccmd = tmp->cmd, dst = rule->cmd ;
ll > 0 ; ll -= ccmdlen, ccmd += ccmdlen, dst += ccmdlen) {
ccmdlen = F_LEN(ccmd);
bcopy(ccmd, dst, F_LEN(ccmd)*sizeof(uint32_t));
if (dst->opcode > O_NAT)
/* O_REASS doesn't exists in 7.2 version, so
* increment opcode if it is after O_REASS
*/
dst->opcode++;
if (ccmdlen > ll) {
printf("ipfw: opcode %d size truncated\n",
ccmd->opcode);
return EINVAL;
}
}
rule->_pad = tmp->_pad;
rule->set = tmp->set;
rule->rulenum = tmp->rulenum;
rule->cmd_len = tmp->cmd_len;
rule->act_ofs = tmp->act_ofs;
rule->next_rule = (struct ip_fw *)tmp->next_rule;
rule->x_next = (struct ip_fw *)tmp->next;
rule->cmd_len = tmp->cmd_len;
rule->id = 0; /* XXX see if is ok = 0 */
rule->pcnt = tmp->pcnt;
rule->bcnt = tmp->bcnt;
rule->timestamp = tmp->timestamp;
free (tmp, M_TEMP);
return 0;
}
/* end of file */
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