blob: 74a81e8f43dab828817943d0cd68b1be75c4bb84 [file] [log] [blame] [raw]
/*
* Copyright (C) 2012 by Darren Reed.
*
* See the IPFILTER.LICENCE file for details on licencing.
*
* $Id$
*/
#define IPF_TFTP_PROXY
typedef struct ipf_tftp_softc_s {
int ipf_p_tftp_readonly;
ipftuneable_t *ipf_p_tftp_tune;
} ipf_tftp_softc_t;
int ipf_p_tftp_backchannel __P((fr_info_t *, ap_session_t *, nat_t *));
int ipf_p_tftp_client __P((ipf_tftp_softc_t *, fr_info_t *, ap_session_t *,
nat_t *));
int ipf_p_tftp_in __P((void *, fr_info_t *, ap_session_t *, nat_t *));
void ipf_p_tftp_main_load __P((void));
void ipf_p_tftp_main_unload __P((void));
int ipf_p_tftp_new __P((void *, fr_info_t *, ap_session_t *, nat_t *));
void ipf_p_tftp_del __P((ipf_main_softc_t *, ap_session_t *));
int ipf_p_tftp_out __P((void *, fr_info_t *, ap_session_t *, nat_t *));
int ipf_p_tftp_server __P((ipf_tftp_softc_t *, fr_info_t *, ap_session_t *,
nat_t *));
void *ipf_p_tftp_soft_create __P((ipf_main_softc_t *));
void ipf_p_tftp_soft_destroy __P((ipf_main_softc_t *, void *));
static frentry_t tftpfr;
static int tftp_proxy_init = 0;
typedef enum tftp_cmd_e {
TFTP_CMD_READ = 1,
TFTP_CMD_WRITE = 2,
TFTP_CMD_DATA = 3,
TFTP_CMD_ACK = 4,
TFTP_CMD_ERROR = 5
} tftp_cmd_t;
typedef struct tftpinfo {
tftp_cmd_t ti_lastcmd;
int ti_nextblk;
int ti_lastblk;
int ti_lasterror;
char ti_filename[80];
ipnat_t *ti_rule;
} tftpinfo_t;
static ipftuneable_t ipf_tftp_tuneables[] = {
{ { (void *)offsetof(ipf_tftp_softc_t, ipf_p_tftp_readonly) },
"tftp_read_only", 0, 1,
stsizeof(ipf_tftp_softc_t, ipf_p_tftp_readonly),
0, NULL, NULL },
{ { NULL }, NULL, 0, 0, 0, 0, NULL, NULL }
};
/*
* TFTP application proxy initialization.
*/
void
ipf_p_tftp_main_load()
{
bzero((char *)&tftpfr, sizeof(tftpfr));
tftpfr.fr_ref = 1;
tftpfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
MUTEX_INIT(&tftpfr.fr_lock, "TFTP proxy rule lock");
tftp_proxy_init = 1;
}
void
ipf_p_tftp_main_unload()
{
if (tftp_proxy_init == 1) {
MUTEX_DESTROY(&tftpfr.fr_lock);
tftp_proxy_init = 0;
}
}
void *
ipf_p_tftp_soft_create(softc)
ipf_main_softc_t *softc;
{
ipf_tftp_softc_t *softt;
KMALLOC(softt, ipf_tftp_softc_t *);
if (softt == NULL)
return NULL;
bzero((char *)softt, sizeof(*softt));
softt->ipf_p_tftp_tune = ipf_tune_array_copy(softt,
sizeof(ipf_tftp_tuneables),
ipf_tftp_tuneables);
if (softt->ipf_p_tftp_tune == NULL) {
ipf_p_tftp_soft_destroy(softc, softt);
return NULL;
}
if (ipf_tune_array_link(softc, softt->ipf_p_tftp_tune) == -1) {
ipf_p_tftp_soft_destroy(softc, softt);
return NULL;
}
softt->ipf_p_tftp_readonly = 1;
return softt;
}
void
ipf_p_tftp_soft_destroy(softc, arg)
ipf_main_softc_t *softc;
void *arg;
{
ipf_tftp_softc_t *softt = arg;
if (softt->ipf_p_tftp_tune != NULL) {
ipf_tune_array_unlink(softc, softt->ipf_p_tftp_tune);
KFREES(softt->ipf_p_tftp_tune, sizeof(ipf_tftp_tuneables));
softt->ipf_p_tftp_tune = NULL;
}
KFREE(softt);
}
int
ipf_p_tftp_out(arg, fin, aps, nat)
void *arg;
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ipf_tftp_softc_t *softt = arg;
fin->fin_flx |= FI_NOWILD;
if (nat->nat_dir == NAT_OUTBOUND)
return ipf_p_tftp_client(softt, fin, aps, nat);
return ipf_p_tftp_server(softt, fin, aps, nat);
}
int
ipf_p_tftp_in(arg, fin, aps, nat)
void *arg;
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ipf_tftp_softc_t *softt = arg;
fin->fin_flx |= FI_NOWILD;
if (nat->nat_dir == NAT_INBOUND)
return ipf_p_tftp_client(softt, fin, aps, nat);
return ipf_p_tftp_server(softt, fin, aps, nat);
}
int
ipf_p_tftp_new(arg, fin, aps, nat)
void *arg;
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
udphdr_t *udp;
tftpinfo_t *ti;
ipnat_t *ipn;
ipnat_t *np;
int size;
fin = fin; /* LINT */
np = nat->nat_ptr;
size = np->in_size;
KMALLOC(ti, tftpinfo_t *);
if (ti == NULL)
return -1;
KMALLOCS(ipn, ipnat_t *, size);
if (ipn == NULL) {
KFREE(ti);
return -1;
}
aps->aps_data = ti;
aps->aps_psiz = sizeof(*ti);
bzero((char *)ti, sizeof(*ti));
bzero((char *)ipn, size);
ti->ti_rule = ipn;
udp = (udphdr_t *)fin->fin_dp;
aps->aps_sport = udp->uh_sport;
aps->aps_dport = udp->uh_dport;
ipn->in_size = size;
ipn->in_apr = NULL;
ipn->in_use = 1;
ipn->in_hits = 1;
ipn->in_ippip = 1;
ipn->in_pr[0] = IPPROTO_UDP;
ipn->in_pr[1] = IPPROTO_UDP;
ipn->in_ifps[0] = nat->nat_ifps[0];
ipn->in_ifps[1] = nat->nat_ifps[1];
ipn->in_v[0] = nat->nat_ptr->in_v[1];
ipn->in_v[1] = nat->nat_ptr->in_v[0];
ipn->in_flags = IPN_UDP|IPN_FIXEDDPORT|IPN_PROXYRULE;
ipn->in_nsrcip6 = nat->nat_odst6;
ipn->in_osrcip6 = nat->nat_ndst6;
if ((np->in_redir & NAT_REDIRECT) != 0) {
ipn->in_redir = NAT_MAP;
if (ipn->in_v[0] == 4) {
ipn->in_snip = ntohl(nat->nat_odstaddr);
ipn->in_dnip = ntohl(nat->nat_nsrcaddr);
} else {
#ifdef USE_INET6
ipn->in_snip6 = nat->nat_odst6;
ipn->in_dnip6 = nat->nat_nsrc6;
#endif
}
ipn->in_ndstip6 = nat->nat_nsrc6;
ipn->in_odstip6 = nat->nat_osrc6;
} else {
ipn->in_redir = NAT_REDIRECT;
if (ipn->in_v[0] == 4) {
ipn->in_snip = ntohl(nat->nat_odstaddr);
ipn->in_dnip = ntohl(nat->nat_osrcaddr);
} else {
#ifdef USE_INET6
ipn->in_snip6 = nat->nat_odst6;
ipn->in_dnip6 = nat->nat_osrc6;
#endif
}
ipn->in_ndstip6 = nat->nat_osrc6;
ipn->in_odstip6 = nat->nat_nsrc6;
}
ipn->in_odport = htons(fin->fin_sport);
ipn->in_ndport = htons(fin->fin_sport);
IP6_SETONES(&ipn->in_osrcmsk6);
IP6_SETONES(&ipn->in_nsrcmsk6);
IP6_SETONES(&ipn->in_odstmsk6);
IP6_SETONES(&ipn->in_ndstmsk6);
MUTEX_INIT(&ipn->in_lock, "tftp proxy NAT rule");
ipn->in_namelen = np->in_namelen;
bcopy(np->in_names, ipn->in_ifnames, ipn->in_namelen);
ipn->in_ifnames[0] = np->in_ifnames[0];
ipn->in_ifnames[1] = np->in_ifnames[1];
ti->ti_lastcmd = 0;
return 0;
}
void
ipf_p_tftp_del(softc, aps)
ipf_main_softc_t *softc;
ap_session_t *aps;
{
tftpinfo_t *tftp;
tftp = aps->aps_data;
if (tftp != NULL) {
tftp->ti_rule->in_flags |= IPN_DELETE;
ipf_nat_rule_deref(softc, &tftp->ti_rule);
}
}
/*
* Setup for a new TFTP proxy.
*/
int
ipf_p_tftp_backchannel(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ipf_main_softc_t *softc = fin->fin_main_soft;
#ifdef USE_MUTEXES
ipf_nat_softc_t *softn = softc->ipf_nat_soft;
#endif
#ifdef USE_INET6
i6addr_t swip6, sw2ip6;
ip6_t *ip6;
#endif
struct in_addr swip, sw2ip;
tftpinfo_t *ti;
udphdr_t udp;
fr_info_t fi;
u_short slen;
nat_t *nat2;
int nflags;
ip_t *ip;
int dir;
ti = aps->aps_data;
/*
* Add skeleton NAT entry for connection which will come back the
* other way.
*/
bcopy((char *)fin, (char *)&fi, sizeof(fi));
fi.fin_flx |= FI_IGNORE;
fi.fin_data[1] = 0;
bzero((char *)&udp, sizeof(udp));
udp.uh_sport = 0; /* XXX - don't specify remote port */
udp.uh_dport = ti->ti_rule->in_ndport;
udp.uh_ulen = htons(sizeof(udp));
udp.uh_sum = 0;
fi.fin_fr = &tftpfr;
fi.fin_dp = (char *)&udp;
fi.fin_sport = 0;
fi.fin_dport = ntohs(ti->ti_rule->in_ndport);
fi.fin_dlen = sizeof(udp);
fi.fin_plen = fi.fin_hlen + sizeof(udp);
fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
nflags = NAT_SLAVE|IPN_UDP|SI_W_SPORT;
#ifdef USE_INET6
ip6 = (ip6_t *)fin->fin_ip;
#endif
ip = fin->fin_ip;
sw2ip.s_addr = 0;
swip.s_addr = 0;
fi.fin_src6 = nat->nat_ndst6;
fi.fin_dst6 = nat->nat_nsrc6;
if (nat->nat_v[0] == 4) {
slen = ip->ip_len;
ip->ip_len = htons(fin->fin_hlen + sizeof(udp));
swip = ip->ip_src;
sw2ip = ip->ip_dst;
ip->ip_src = nat->nat_ndstip;
ip->ip_dst = nat->nat_nsrcip;
} else {
#ifdef USE_INET6
slen = ip6->ip6_plen;
ip6->ip6_plen = htons(sizeof(udp));
swip6.in6 = ip6->ip6_src;
sw2ip6.in6 = ip6->ip6_dst;
ip6->ip6_src = nat->nat_ndst6.in6;
ip6->ip6_dst = nat->nat_nsrc6.in6;
#endif
}
if (nat->nat_dir == NAT_INBOUND) {
dir = NAT_OUTBOUND;
fi.fin_out = 1;
} else {
dir = NAT_INBOUND;
fi.fin_out = 0;
}
nflags |= NAT_NOTRULEPORT;
MUTEX_ENTER(&softn->ipf_nat_new);
if (nat->nat_v[0] == 4)
nat2 = ipf_nat_add(&fi, ti->ti_rule, NULL, nflags, dir);
else
nat2 = ipf_nat6_add(&fi, ti->ti_rule, NULL, nflags, dir);
MUTEX_EXIT(&softn->ipf_nat_new);
if (nat2 != NULL) {
(void) ipf_nat_proto(&fi, nat2, IPN_UDP);
ipf_nat_update(&fi, nat2);
fi.fin_ifp = NULL;
if (ti->ti_rule->in_redir == NAT_MAP) {
fi.fin_src6 = nat->nat_ndst6;
fi.fin_dst6 = nat->nat_nsrc6;
if (nat->nat_v[0] == 4) {
ip->ip_src = nat->nat_ndstip;
ip->ip_dst = nat->nat_nsrcip;
} else {
#ifdef USE_INET6
ip6->ip6_src = nat->nat_ndst6.in6;
ip6->ip6_dst = nat->nat_nsrc6.in6;
#endif
}
} else {
fi.fin_src6 = nat->nat_odst6;
fi.fin_dst6 = nat->nat_osrc6;
if (fin->fin_v == 4) {
ip->ip_src = nat->nat_odstip;
ip->ip_dst = nat->nat_osrcip;
} else {
#ifdef USE_INET6
ip6->ip6_src = nat->nat_odst6.in6;
ip6->ip6_dst = nat->nat_osrc6.in6;
#endif
}
}
if (ipf_state_add(softc, &fi, NULL, SI_W_SPORT) != 0) {
ipf_nat_setpending(softc, nat2);
}
}
if (nat->nat_v[0] == 4) {
ip->ip_len = slen;
ip->ip_src = swip;
ip->ip_dst = sw2ip;
} else {
#ifdef USE_INET6
ip6->ip6_plen = slen;
ip6->ip6_src = swip6.in6;
ip6->ip6_dst = sw2ip6.in6;
#endif
}
return 0;
}
int
ipf_p_tftp_client(softt, fin, aps, nat)
ipf_tftp_softc_t *softt;
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
u_char *msg, *s, *t;
tftpinfo_t *ti;
u_short opcode;
udphdr_t *udp;
int len;
if (fin->fin_dlen < 4)
return 0;
ti = aps->aps_data;
msg = fin->fin_dp;
msg += sizeof(udphdr_t);
opcode = (msg[0] << 8) | msg[1];
DT3(tftp_cmd, fr_info_t *, fin, int, opcode, nat_t *, nat);
switch (opcode)
{
case TFTP_CMD_WRITE :
if (softt->ipf_p_tftp_readonly != 0)
break;
/* FALLTHROUGH */
case TFTP_CMD_READ :
len = fin->fin_dlen - sizeof(*udp) - 2;
if (len > sizeof(ti->ti_filename) - 1)
len = sizeof(ti->ti_filename) - 1;
s = msg + 2;
for (t = (u_char *)ti->ti_filename; (len > 0); len--, s++) {
*t++ = *s;
if (*s == '\0')
break;
}
ipf_p_tftp_backchannel(fin, aps, nat);
break;
default :
return -1;
}
ti = aps->aps_data;
ti->ti_lastcmd = opcode;
return 0;
}
int
ipf_p_tftp_server(softt, fin, aps, nat)
ipf_tftp_softc_t *softt;
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
tftpinfo_t *ti;
u_short opcode;
u_short arg;
u_char *msg;
if (fin->fin_dlen < 4)
return 0;
ti = aps->aps_data;
msg = fin->fin_dp;
msg += sizeof(udphdr_t);
arg = (msg[2] << 8) | msg[3];
opcode = (msg[0] << 8) | msg[1];
switch (opcode)
{
case TFTP_CMD_ACK :
ti->ti_lastblk = arg;
break;
case TFTP_CMD_ERROR :
ti->ti_lasterror = arg;
break;
default :
return -1;
}
ti->ti_lastcmd = opcode;
return 0;
}