freebsd-skq/sbin/ipfw/ipv6.c
Andrey V. Elsukov 23b93085c2 Add support for non-contiguous IPv6 masks in ipfw(8) rules.
For example fe::640:0:0/ffff::ffff:ffff:0:0 will match
addresses fe:*:*:*:0:640:*:*

Submitted by:	Eugene Mamchits <mamchits at yandex-team dot ru>
Obtained from:	Yandex LLC
MFC after:	2 weeks
Sponsored by:	Yandex LLC
2016-10-18 15:14:46 +00:00

543 lines
13 KiB
C

/*
* Copyright (c) 2002-2003 Luigi Rizzo
* Copyright (c) 1996 Alex Nash, Paul Traina, Poul-Henning Kamp
* Copyright (c) 1994 Ugen J.S.Antsilevich
*
* Idea and grammar partially left from:
* Copyright (c) 1993 Daniel Boulet
*
* Redistribution and use in source forms, with and without modification,
* are permitted provided that this entire comment appears intact.
*
* Redistribution in binary form may occur without any restrictions.
* Obviously, it would be nice if you gave credit where credit is due
* but requiring it would be too onerous.
*
* This software is provided ``AS IS'' without any warranties of any kind.
*
* NEW command line interface for IP firewall facility
*
* $FreeBSD$
*
* ipv6 support
*/
#include <sys/types.h>
#include <sys/socket.h>
#include "ipfw2.h"
#include <err.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <net/if.h>
#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/icmp6.h>
#include <netinet/ip_fw.h>
#include <arpa/inet.h>
#define CHECK_LENGTH(v, len) do { \
if ((v) < (len)) \
errx(EX_DATAERR, "Rule too long"); \
} while (0)
static struct _s_x icmp6codes[] = {
{ "no-route", ICMP6_DST_UNREACH_NOROUTE },
{ "admin-prohib", ICMP6_DST_UNREACH_ADMIN },
{ "address", ICMP6_DST_UNREACH_ADDR },
{ "port", ICMP6_DST_UNREACH_NOPORT },
{ NULL, 0 }
};
void
fill_unreach6_code(u_short *codep, char *str)
{
int val;
char *s;
val = strtoul(str, &s, 0);
if (s == str || *s != '\0' || val >= 0x100)
val = match_token(icmp6codes, str);
if (val < 0)
errx(EX_DATAERR, "unknown ICMPv6 unreachable code ``%s''", str);
*codep = val;
return;
}
void
print_unreach6_code(struct buf_pr *bp, uint16_t code)
{
char const *s = match_value(icmp6codes, code);
if (s != NULL)
bprintf(bp, "unreach6 %s", s);
else
bprintf(bp, "unreach6 %u", code);
}
/*
* Print the ip address contained in a command.
*/
void
print_ip6(struct buf_pr *bp, ipfw_insn_ip6 *cmd, char const *s)
{
struct hostent *he = NULL;
int len = F_LEN((ipfw_insn *) cmd) - 1;
struct in6_addr *a = &(cmd->addr6);
char trad[255];
bprintf(bp, "%s%s ", cmd->o.len & F_NOT ? " not": "", s);
if (cmd->o.opcode == O_IP6_SRC_ME || cmd->o.opcode == O_IP6_DST_ME) {
bprintf(bp, "me6");
return;
}
if (cmd->o.opcode == O_IP6) {
bprintf(bp, " ip6");
return;
}
/*
* len == 4 indicates a single IP, whereas lists of 1 or more
* addr/mask pairs have len = (2n+1). We convert len to n so we
* use that to count the number of entries.
*/
for (len = len / 4; len > 0; len -= 2, a += 2) {
int mb = /* mask length */
(cmd->o.opcode == O_IP6_SRC || cmd->o.opcode == O_IP6_DST) ?
128 : contigmask((uint8_t *)&(a[1]), 128);
if (mb == 128 && co.do_resolv)
he = gethostbyaddr((char *)a, sizeof(*a), AF_INET6);
if (he != NULL) /* resolved to name */
bprintf(bp, "%s", he->h_name);
else if (mb == 0) /* any */
bprintf(bp, "any");
else { /* numeric IP followed by some kind of mask */
if (inet_ntop(AF_INET6, a, trad, sizeof( trad ) ) == NULL)
bprintf(bp, "Error ntop in print_ip6\n");
bprintf(bp, "%s", trad );
if (mb < 0) /* mask not contiguous */
bprintf(bp, "/%s",
inet_ntop(AF_INET6, &a[1], trad, sizeof(trad)));
else if (mb < 128)
bprintf(bp, "/%d", mb);
}
if (len > 2)
bprintf(bp, ",");
}
}
void
fill_icmp6types(ipfw_insn_icmp6 *cmd, char *av, int cblen)
{
uint8_t type;
CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_icmp6));
bzero(cmd, sizeof(*cmd));
while (*av) {
if (*av == ',')
av++;
type = strtoul(av, &av, 0);
if (*av != ',' && *av != '\0')
errx(EX_DATAERR, "invalid ICMP6 type");
/*
* XXX: shouldn't this be 0xFF? I can't see any reason why
* we shouldn't be able to filter all possiable values
* regardless of the ability of the rest of the kernel to do
* anything useful with them.
*/
if (type > ICMP6_MAXTYPE)
errx(EX_DATAERR, "ICMP6 type out of range");
cmd->d[type / 32] |= ( 1 << (type % 32));
}
cmd->o.opcode = O_ICMP6TYPE;
cmd->o.len |= F_INSN_SIZE(ipfw_insn_icmp6);
}
void
print_icmp6types(struct buf_pr *bp, ipfw_insn_u32 *cmd)
{
int i, j;
char sep= ' ';
bprintf(bp, " ip6 icmp6types");
for (i = 0; i < 7; i++)
for (j=0; j < 32; ++j) {
if ( (cmd->d[i] & (1 << (j))) == 0)
continue;
bprintf(bp, "%c%d", sep, (i*32 + j));
sep = ',';
}
}
void
print_flow6id(struct buf_pr *bp, ipfw_insn_u32 *cmd)
{
uint16_t i, limit = cmd->o.arg1;
char sep = ',';
bprintf(bp, " flow-id ");
for( i=0; i < limit; ++i) {
if (i == limit - 1)
sep = ' ';
bprintf(bp, "%d%c", cmd->d[i], sep);
}
}
/* structure and define for the extension header in ipv6 */
static struct _s_x ext6hdrcodes[] = {
{ "frag", EXT_FRAGMENT },
{ "hopopt", EXT_HOPOPTS },
{ "route", EXT_ROUTING },
{ "dstopt", EXT_DSTOPTS },
{ "ah", EXT_AH },
{ "esp", EXT_ESP },
{ "rthdr0", EXT_RTHDR0 },
{ "rthdr2", EXT_RTHDR2 },
{ NULL, 0 }
};
/* fills command for the extension header filtering */
int
fill_ext6hdr( ipfw_insn *cmd, char *av)
{
int tok;
char *s = av;
cmd->arg1 = 0;
while(s) {
av = strsep( &s, ",") ;
tok = match_token(ext6hdrcodes, av);
switch (tok) {
case EXT_FRAGMENT:
cmd->arg1 |= EXT_FRAGMENT;
break;
case EXT_HOPOPTS:
cmd->arg1 |= EXT_HOPOPTS;
break;
case EXT_ROUTING:
cmd->arg1 |= EXT_ROUTING;
break;
case EXT_DSTOPTS:
cmd->arg1 |= EXT_DSTOPTS;
break;
case EXT_AH:
cmd->arg1 |= EXT_AH;
break;
case EXT_ESP:
cmd->arg1 |= EXT_ESP;
break;
case EXT_RTHDR0:
cmd->arg1 |= EXT_RTHDR0;
break;
case EXT_RTHDR2:
cmd->arg1 |= EXT_RTHDR2;
break;
default:
errx( EX_DATAERR, "invalid option for ipv6 exten header" );
break;
}
}
if (cmd->arg1 == 0 )
return 0;
cmd->opcode = O_EXT_HDR;
cmd->len |= F_INSN_SIZE( ipfw_insn );
return 1;
}
void
print_ext6hdr(struct buf_pr *bp, ipfw_insn *cmd )
{
char sep = ' ';
bprintf(bp, " extension header:");
if (cmd->arg1 & EXT_FRAGMENT ) {
bprintf(bp, "%cfragmentation", sep);
sep = ',';
}
if (cmd->arg1 & EXT_HOPOPTS ) {
bprintf(bp, "%chop options", sep);
sep = ',';
}
if (cmd->arg1 & EXT_ROUTING ) {
bprintf(bp, "%crouting options", sep);
sep = ',';
}
if (cmd->arg1 & EXT_RTHDR0 ) {
bprintf(bp, "%crthdr0", sep);
sep = ',';
}
if (cmd->arg1 & EXT_RTHDR2 ) {
bprintf(bp, "%crthdr2", sep);
sep = ',';
}
if (cmd->arg1 & EXT_DSTOPTS ) {
bprintf(bp, "%cdestination options", sep);
sep = ',';
}
if (cmd->arg1 & EXT_AH ) {
bprintf(bp, "%cauthentication header", sep);
sep = ',';
}
if (cmd->arg1 & EXT_ESP ) {
bprintf(bp, "%cencapsulated security payload", sep);
}
}
/* Try to find ipv6 address by hostname */
static int
lookup_host6 (char *host, struct in6_addr *ip6addr)
{
struct hostent *he;
if (!inet_pton(AF_INET6, host, ip6addr)) {
if ((he = gethostbyname2(host, AF_INET6)) == NULL)
return(-1);
memcpy(ip6addr, he->h_addr_list[0], sizeof( struct in6_addr));
}
return(0);
}
/*
* fill the addr and mask fields in the instruction as appropriate from av.
* Update length as appropriate.
* The following formats are allowed:
* any matches any IP6. Actually returns an empty instruction.
* me returns O_IP6_*_ME
*
* 03f1::234:123:0342 single IP6 address
* 03f1::234:123:0342/24 address/masklen
* 03f1::234:123:0342/ffff::ffff:ffff address/mask
* 03f1::234:123:0342/24,03f1::234:123:0343/ List of address
*
* Set of address (as in ipv6) not supported because ipv6 address
* are typically random past the initial prefix.
* Return 1 on success, 0 on failure.
*/
static int
fill_ip6(ipfw_insn_ip6 *cmd, char *av, int cblen)
{
int len = 0;
struct in6_addr *d = &(cmd->addr6);
/*
* Needed for multiple address.
* Note d[1] points to struct in6_add r mask6 of cmd
*/
cmd->o.len &= ~F_LEN_MASK; /* zero len */
if (strcmp(av, "any") == 0)
return (1);
if (strcmp(av, "me") == 0) { /* Set the data for "me" opt*/
cmd->o.len |= F_INSN_SIZE(ipfw_insn);
return (1);
}
if (strcmp(av, "me6") == 0) { /* Set the data for "me" opt*/
cmd->o.len |= F_INSN_SIZE(ipfw_insn);
return (1);
}
if (strncmp(av, "table(", 6) == 0) {
char *p = strchr(av + 6, ',');
uint32_t *dm = ((ipfw_insn_u32 *)cmd)->d;
if (p)
*p++ = '\0';
cmd->o.opcode = O_IP_DST_LOOKUP;
cmd->o.arg1 = strtoul(av + 6, NULL, 0);
if (p) {
cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32);
dm[0] = strtoul(p, NULL, 0);
} else
cmd->o.len |= F_INSN_SIZE(ipfw_insn);
return (1);
}
av = strdup(av);
while (av) {
/*
* After the address we can have '/' indicating a mask,
* or ',' indicating another address follows.
*/
char *p, *q;
int masklen;
char md = '\0';
CHECK_LENGTH(cblen, 1 + len + 2 * F_INSN_SIZE(struct in6_addr));
if ((q = strchr(av, ',')) ) {
*q = '\0';
q++;
}
if ((p = strchr(av, '/')) ) {
md = *p; /* save the separator */
*p = '\0'; /* terminate address string */
p++; /* and skip past it */
}
/* now p points to NULL, mask or next entry */
/* lookup stores address in *d as a side effect */
if (lookup_host6(av, d) != 0) {
/* XXX: failed. Free memory and go */
errx(EX_DATAERR, "bad address \"%s\"", av);
}
/* next, look at the mask, if any */
if (md == '/' && strchr(p, ':')) {
if (!inet_pton(AF_INET6, p, &d[1]))
errx(EX_DATAERR, "bad mask \"%s\"", p);
masklen = contigmask((uint8_t *)&(d[1]), 128);
} else {
masklen = (md == '/') ? atoi(p) : 128;
if (masklen > 128 || masklen < 0)
errx(EX_DATAERR, "bad width \"%s\''", p);
else
n2mask(&d[1], masklen);
}
APPLY_MASK(d, &d[1]) /* mask base address with mask */
av = q;
/* Check this entry */
if (masklen == 0) {
/*
* 'any' turns the entire list into a NOP.
* 'not any' never matches, so it is removed from the
* list unless it is the only item, in which case we
* report an error.
*/
if (cmd->o.len & F_NOT && av == NULL && len == 0)
errx(EX_DATAERR, "not any never matches");
continue;
}
/*
* A single IP can be stored alone
*/
if (masklen == 128 && av == NULL && len == 0) {
len = F_INSN_SIZE(struct in6_addr);
break;
}
/* Update length and pointer to arguments */
len += F_INSN_SIZE(struct in6_addr)*2;
d += 2;
} /* end while */
/*
* Total length of the command, remember that 1 is the size of
* the base command.
*/
if (len + 1 > F_LEN_MASK)
errx(EX_DATAERR, "address list too long");
cmd->o.len |= len+1;
free(av);
return (1);
}
/*
* fills command for ipv6 flow-id filtering
* note that the 20 bit flow number is stored in a array of u_int32_t
* it's supported lists of flow-id, so in the o.arg1 we store how many
* additional flow-id we want to filter, the basic is 1
*/
void
fill_flow6( ipfw_insn_u32 *cmd, char *av, int cblen)
{
u_int32_t type; /* Current flow number */
u_int16_t nflow = 0; /* Current flow index */
char *s = av;
cmd->d[0] = 0; /* Initializing the base number*/
while (s) {
CHECK_LENGTH(cblen, F_INSN_SIZE(ipfw_insn_u32) + nflow + 1);
av = strsep( &s, ",") ;
type = strtoul(av, &av, 0);
if (*av != ',' && *av != '\0')
errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
if (type > 0xfffff)
errx(EX_DATAERR, "flow number out of range %s", av);
cmd->d[nflow] |= type;
nflow++;
}
if( nflow > 0 ) {
cmd->o.opcode = O_FLOW6ID;
cmd->o.len |= F_INSN_SIZE(ipfw_insn_u32) + nflow;
cmd->o.arg1 = nflow;
}
else {
errx(EX_DATAERR, "invalid ipv6 flow number %s", av);
}
}
ipfw_insn *
add_srcip6(ipfw_insn *cmd, char *av, int cblen)
{
fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen);
if (cmd->opcode == O_IP_DST_SET) /* set */
cmd->opcode = O_IP_SRC_SET;
else if (cmd->opcode == O_IP_DST_LOOKUP) /* table */
cmd->opcode = O_IP_SRC_LOOKUP;
else if (F_LEN(cmd) == 0) { /* any */
} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) { /* "me" */
cmd->opcode = O_IP6_SRC_ME;
} else if (F_LEN(cmd) ==
(F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
/* single IP, no mask*/
cmd->opcode = O_IP6_SRC;
} else { /* addr/mask opt */
cmd->opcode = O_IP6_SRC_MASK;
}
return cmd;
}
ipfw_insn *
add_dstip6(ipfw_insn *cmd, char *av, int cblen)
{
fill_ip6((ipfw_insn_ip6 *)cmd, av, cblen);
if (cmd->opcode == O_IP_DST_SET) /* set */
;
else if (cmd->opcode == O_IP_DST_LOOKUP) /* table */
;
else if (F_LEN(cmd) == 0) { /* any */
} else if (F_LEN(cmd) == F_INSN_SIZE(ipfw_insn)) { /* "me" */
cmd->opcode = O_IP6_DST_ME;
} else if (F_LEN(cmd) ==
(F_INSN_SIZE(struct in6_addr) + F_INSN_SIZE(ipfw_insn))) {
/* single IP, no mask*/
cmd->opcode = O_IP6_DST;
} else { /* addr/mask opt */
cmd->opcode = O_IP6_DST_MASK;
}
return cmd;
}