NetBSD-5.0.2/sys/dist/ipf/netinet/ip_ftp_pxy.c
/* $NetBSD: ip_ftp_pxy.c,v 1.14 2007/12/11 04:55:00 lukem Exp $ */
/*
* Copyright (C) 1997-2003 by Darren Reed
*
* See the IPFILTER.LICENCE file for details on licencing.
*
* Simple FTP transparent proxy for in-kernel use. For use with the NAT
* code.
*
* Id: ip_ftp_pxy.c,v 2.88.2.22 2007/05/10 09:30:39 darrenr Exp
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(1, "$NetBSD: ip_ftp_pxy.c,v 1.14 2007/12/11 04:55:00 lukem Exp $");
#define IPF_FTP_PROXY
#define IPF_MINPORTLEN 18
#define IPF_MAXPORTLEN 30
#define IPF_MIN227LEN 39
#define IPF_MAX227LEN 51
#define IPF_MIN229LEN 47
#define IPF_MAX229LEN 51
#define FTPXY_GO 0
#define FTPXY_INIT 1
#define FTPXY_USER_1 2
#define FTPXY_USOK_1 3
#define FTPXY_PASS_1 4
#define FTPXY_PAOK_1 5
#define FTPXY_AUTH_1 6
#define FTPXY_AUOK_1 7
#define FTPXY_ADAT_1 8
#define FTPXY_ADOK_1 9
#define FTPXY_ACCT_1 10
#define FTPXY_ACOK_1 11
#define FTPXY_USER_2 12
#define FTPXY_USOK_2 13
#define FTPXY_PASS_2 14
#define FTPXY_PAOK_2 15
/*
* Values for FTP commands. Numerics cover 0-999
*/
#define FTPXY_C_PASV 1000
int ippr_ftp_client __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_complete __P((char *, size_t));
int ippr_ftp_in __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_ftp_init __P((void));
void ippr_ftp_fini __P((void));
int ippr_ftp_new __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_ftp_out __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_ftp_pasv __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_epsv __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *, int));
int ippr_ftp_port __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *, int));
int ippr_ftp_process __P((fr_info_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_server __P((fr_info_t *, ip_t *, nat_t *, ftpinfo_t *, int));
int ippr_ftp_valid __P((ftpinfo_t *, int, char *, size_t));
int ippr_ftp_server_valid __P((ftpside_t *, char *, size_t));
int ippr_ftp_client_valid __P((ftpside_t *, char *, size_t));
u_short ippr_ftp_atoi __P((char **));
int ippr_ftp_pasvreply __P((fr_info_t *, ip_t *, nat_t *, ftpside_t *,
u_int, char *, char *, u_int));
int ftp_proxy_init = 0;
int ippr_ftp_pasvonly = 0;
int ippr_ftp_insecure = 0; /* Do not require logins before transfers */
int ippr_ftp_pasvrdr = 0;
int ippr_ftp_forcepasv = 0; /* PASV must be last command prior to 227 */
#if defined(_KERNEL)
int ippr_ftp_debug = 0;
#else
int ippr_ftp_debug = 2;
#endif
/*
* 1 - security
* 2 - errors
* 3 - error debugging
* 4 - parsing errors
* 5 - parsing info
* 6 - parsing debug
*/
static frentry_t ftppxyfr;
static ipftuneable_t ftptune = {
{ &ippr_ftp_debug },
"ippr_ftp_debug",
0,
10,
sizeof(ippr_ftp_debug),
0,
NULL
};
/*
* Initialize local structures.
*/
int ippr_ftp_init()
{
bzero((char *)&ftppxyfr, sizeof(ftppxyfr));
ftppxyfr.fr_ref = 1;
ftppxyfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
MUTEX_INIT(&ftppxyfr.fr_lock, "FTP Proxy Mutex");
ftp_proxy_init = 1;
(void) fr_addipftune(&ftptune);
return 0;
}
void ippr_ftp_fini()
{
(void) fr_delipftune(&ftptune);
if (ftp_proxy_init == 1) {
MUTEX_DESTROY(&ftppxyfr.fr_lock);
ftp_proxy_init = 0;
}
}
int ippr_ftp_new(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ftpinfo_t *ftp;
ftpside_t *f;
KMALLOC(ftp, ftpinfo_t *);
if (ftp == NULL)
return -1;
fin = fin; /* LINT */
nat = nat; /* LINT */
aps->aps_data = ftp;
aps->aps_psiz = sizeof(ftpinfo_t);
bzero((char *)ftp, sizeof(*ftp));
f = &ftp->ftp_side[0];
f->ftps_rptr = f->ftps_buf;
f->ftps_wptr = f->ftps_buf;
f = &ftp->ftp_side[1];
f->ftps_rptr = f->ftps_buf;
f->ftps_wptr = f->ftps_buf;
ftp->ftp_passok = FTPXY_INIT;
ftp->ftp_incok = 0;
return 0;
}
int ippr_ftp_port(fin, ip, nat, f, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpside_t *f;
int dlen;
{
tcphdr_t *tcp, tcph, *tcp2 = &tcph;
char newbuf[IPF_FTPBUFSZ], *s;
struct in_addr swip, swip2;
u_int a1, a2, a3, a4;
int inc, off, flags;
u_short a5, a6, sp;
size_t nlen, olen;
fr_info_t fi;
nat_t *nat2;
mb_t *m;
m = fin->fin_m;
tcp = (tcphdr_t *)fin->fin_dp;
off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
/*
* Check for client sending out PORT message.
*/
if (dlen < IPF_MINPORTLEN) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_port:dlen(%d) < IPF_MINPORTLEN\n",
dlen);
return 0;
}
/*
* Skip the PORT command + space
*/
s = f->ftps_rptr + 5;
/*
* Pick out the address components, two at a time.
*/
a1 = ippr_ftp_atoi(&s);
if (s == NULL) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 1);
return 0;
}
a2 = ippr_ftp_atoi(&s);
if (s == NULL) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 2);
return 0;
}
/*
* Check that IP address in the PORT/PASV reply is the same as the
* sender of the command - prevents using PORT for port scanning.
*/
a1 <<= 16;
a1 |= a2;
if (((nat->nat_dir == NAT_OUTBOUND) &&
(a1 != ntohl(nat->nat_inip.s_addr))) ||
((nat->nat_dir == NAT_INBOUND) &&
(a1 != ntohl(nat->nat_oip.s_addr)))) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_port:%s != nat->nat_inip\n", "a1");
return APR_ERR(1);
}
a5 = ippr_ftp_atoi(&s);
if (s == NULL) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_port:ippr_ftp_atoi(%d) failed\n", 3);
return 0;
}
if (*s == ')')
s++;
/*
* check for CR-LF at the end.
*/
if (*s == '\n')
s--;
if ((*s == '\r') && (*(s + 1) == '\n')) {
s += 2;
a6 = a5 & 0xff;
} else {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_port:missing %s\n", "cr-lf");
return 0;
}
a5 >>= 8;
a5 &= 0xff;
sp = a5 << 8 | a6;
/*
* Don't allow the PORT command to specify a port < 1024 due to
* security crap.
*/
if (sp < 1024) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_port:sp(%d) < 1024\n", sp);
return 0;
}
/*
* Calculate new address parts for PORT command
*/
if (nat->nat_dir == NAT_INBOUND)
a1 = ntohl(nat->nat_oip.s_addr);
else
a1 = ntohl(ip->ip_src.s_addr);
a2 = (a1 >> 16) & 0xff;
a3 = (a1 >> 8) & 0xff;
a4 = a1 & 0xff;
a1 >>= 24;
olen = s - f->ftps_rptr;
/* DO NOT change this to snprintf! */
#if defined(SNPRINTF) && defined(_KERNEL)
SNPRINTF(newbuf, sizeof(newbuf), "%s %u,%u,%u,%u,%u,%u\r\n",
"PORT", a1, a2, a3, a4, a5, a6);
#else
(void) sprintf(newbuf, "%s %u,%u,%u,%u,%u,%u\r\n",
"PORT", a1, a2, a3, a4, a5, a6);
#endif
nlen = strlen(newbuf);
inc = nlen - olen;
if ((inc + ip->ip_len) > 65535) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_port:inc(%d) + ip->ip_len > 65535\n",
inc);
return 0;
}
#if !defined(_KERNEL)
bcopy(newbuf, MTOD(m, char *) + off, nlen);
#else
# if defined(MENTAT)
if (inc < 0)
(void)adjmsg(m, inc);
# else /* defined(MENTAT) */
/*
* m_adj takes care of pkthdr.len, if required and treats inc<0 to
* mean remove -len bytes from the end of the packet.
* The mbuf chain will be extended if necessary by m_copyback().
*/
if (inc < 0)
m_adj(m, inc);
# endif /* defined(MENTAT) */
#endif /* !defined(_KERNEL) */
COPYBACK(m, off, nlen, newbuf);
if (inc != 0) {
ip->ip_len += inc;
fin->fin_dlen += inc;
fin->fin_plen += inc;
}
/*
* The server may not make the connection back from port 20, but
* it is the most likely so use it here to check for a conflicting
* mapping.
*/
bcopy((char *)fin, (char *)&fi, sizeof(fi));
fi.fin_state = NULL;
fi.fin_nat = NULL;
fi.fin_flx |= FI_IGNORE;
fi.fin_data[0] = sp;
fi.fin_data[1] = fin->fin_data[1] - 1;
/*
* Add skeleton NAT entry for connection which will come back the
* other way.
*/
if (nat->nat_dir == NAT_OUTBOUND)
nat2 = nat_outlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p,
nat->nat_inip, nat->nat_oip);
else
nat2 = nat_inlookup(&fi, NAT_SEARCH|IPN_TCP, nat->nat_p,
nat->nat_inip, nat->nat_oip);
if (nat2 == NULL) {
int slen;
slen = ip->ip_len;
ip->ip_len = fin->fin_hlen + sizeof(*tcp2);
bzero((char *)tcp2, sizeof(*tcp2));
tcp2->th_win = htons(8192);
tcp2->th_sport = htons(sp);
TCP_OFF_A(tcp2, 5);
tcp2->th_flags = TH_SYN;
tcp2->th_dport = 0; /* XXX - don't specify remote port */
fi.fin_data[1] = 0;
fi.fin_dlen = sizeof(*tcp2);
fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
fi.fin_dp = (char *)tcp2;
fi.fin_fr = &ftppxyfr;
fi.fin_out = nat->nat_dir;
fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
swip = ip->ip_src;
swip2 = ip->ip_dst;
if (nat->nat_dir == NAT_OUTBOUND) {
fi.fin_fi.fi_saddr = nat->nat_inip.s_addr;
ip->ip_src = nat->nat_inip;
} else if (nat->nat_dir == NAT_INBOUND) {
fi.fin_fi.fi_saddr = nat->nat_oip.s_addr;
ip->ip_src = nat->nat_oip;
}
flags = NAT_SLAVE|IPN_TCP|SI_W_DPORT;
if (nat->nat_dir == NAT_INBOUND)
flags |= NAT_NOTRULEPORT;
nat2 = nat_new(&fi, nat->nat_ptr, NULL, flags, nat->nat_dir);
if (nat2 != NULL) {
(void) nat_proto(&fi, nat2, IPN_TCP);
nat_update(&fi, nat2, nat->nat_ptr);
fi.fin_ifp = NULL;
if (nat->nat_dir == NAT_INBOUND) {
fi.fin_fi.fi_daddr = nat->nat_inip.s_addr;
ip->ip_dst = nat->nat_inip;
}
(void) fr_addstate(&fi, NULL, SI_W_DPORT);
if (fi.fin_state != NULL)
fr_statederef((ipstate_t **)&fi.fin_state);
}
ip->ip_len = slen;
ip->ip_src = swip;
ip->ip_dst = swip2;
}
return APR_INC(inc);
}
int ippr_ftp_client(fin, ip, nat, ftp, dlen)
fr_info_t *fin;
nat_t *nat;
ftpinfo_t *ftp;
ip_t *ip;
int dlen;
{
char *rptr, *wptr, cmd[6], c;
ftpside_t *f;
int inc, i;
inc = 0;
f = &ftp->ftp_side[0];
rptr = f->ftps_rptr;
wptr = f->ftps_wptr;
for (i = 0; (i < 5) && (i < dlen); i++) {
c = rptr[i];
if (ISALPHA(c)) {
cmd[i] = TOUPPER(c);
} else {
cmd[i] = c;
}
}
cmd[i] = '\0';
ftp->ftp_incok = 0;
if (!strncmp(cmd, "USER ", 5) || !strncmp(cmd, "XAUT ", 5)) {
if (ftp->ftp_passok == FTPXY_ADOK_1 ||
ftp->ftp_passok == FTPXY_AUOK_1) {
ftp->ftp_passok = FTPXY_USER_2;
ftp->ftp_incok = 1;
} else {
ftp->ftp_passok = FTPXY_USER_1;
ftp->ftp_incok = 1;
}
} else if (!strncmp(cmd, "AUTH ", 5)) {
ftp->ftp_passok = FTPXY_AUTH_1;
ftp->ftp_incok = 1;
} else if (!strncmp(cmd, "PASS ", 5)) {
if (ftp->ftp_passok == FTPXY_USOK_1) {
ftp->ftp_passok = FTPXY_PASS_1;
ftp->ftp_incok = 1;
} else if (ftp->ftp_passok == FTPXY_USOK_2) {
ftp->ftp_passok = FTPXY_PASS_2;
ftp->ftp_incok = 1;
}
} else if ((ftp->ftp_passok == FTPXY_AUOK_1) &&
!strncmp(cmd, "ADAT ", 5)) {
ftp->ftp_passok = FTPXY_ADAT_1;
ftp->ftp_incok = 1;
} else if ((ftp->ftp_passok == FTPXY_PAOK_1 ||
ftp->ftp_passok == FTPXY_PAOK_2) &&
!strncmp(cmd, "ACCT ", 5)) {
ftp->ftp_passok = FTPXY_ACCT_1;
ftp->ftp_incok = 1;
} else if ((ftp->ftp_passok == FTPXY_GO) && !ippr_ftp_pasvonly &&
!strncmp(cmd, "PORT ", 5)) {
inc = ippr_ftp_port(fin, ip, nat, f, dlen);
} else if (ippr_ftp_insecure && !ippr_ftp_pasvonly &&
!strncmp(cmd, "PORT ", 5)) {
inc = ippr_ftp_port(fin, ip, nat, f, dlen);
}
while ((*rptr++ != '\n') && (rptr < wptr))
;
f->ftps_rptr = rptr;
return inc;
}
int ippr_ftp_pasv(fin, ip, nat, ftp, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpinfo_t *ftp;
int dlen;
{
u_int a1, a2, a3, a4, data_ip;
char newbuf[IPF_FTPBUFSZ];
const char *brackets[2];
u_short a5, a6;
ftpside_t *f;
char *s;
if (ippr_ftp_forcepasv != 0 &&
ftp->ftp_side[0].ftps_cmds != FTPXY_C_PASV) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_pasv:ftps_cmds(%d) != FTPXY_C_PASV\n",
ftp->ftp_side[0].ftps_cmds);
return 0;
}
f = &ftp->ftp_side[1];
#define PASV_REPLEN 24
/*
* Check for PASV reply message.
*/
if (dlen < IPF_MIN227LEN) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_pasv:dlen(%d) < IPF_MIN227LEN\n",
dlen);
return 0;
} else if (strncmp(f->ftps_rptr,
"227 Entering Passive Mod", PASV_REPLEN)) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_pasv:%d reply wrong\n", 227);
return 0;
}
brackets[0] = "";
brackets[1] = "";
/*
* Skip the PASV reply + space
*/
s = f->ftps_rptr + PASV_REPLEN;
while (*s && !ISDIGIT(*s)) {
if (*s == '(') {
brackets[0] = "(";
brackets[1] = ")";
}
s++;
}
/*
* Pick out the address components, two at a time.
*/
a1 = ippr_ftp_atoi(&s);
if (s == NULL) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 1);
return 0;
}
a2 = ippr_ftp_atoi(&s);
if (s == NULL) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 2);
return 0;
}
/*
* check that IP address in the PASV reply is the same as the
* sender of the command - prevents using PASV for port scanning.
*/
a1 <<= 16;
a1 |= a2;
if (((nat->nat_dir == NAT_INBOUND) &&
(a1 != ntohl(nat->nat_inip.s_addr))) ||
((nat->nat_dir == NAT_OUTBOUND) &&
(a1 != ntohl(nat->nat_oip.s_addr)))) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_pasv:%s != nat->nat_oip\n", "a1");
return 0;
}
a5 = ippr_ftp_atoi(&s);
if (s == NULL) {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_pasv:ippr_ftp_atoi(%d) failed\n", 3);
return 0;
}
if (*s == ')')
s++;
if (*s == '.')
s++;
if (*s == '\n')
s--;
/*
* check for CR-LF at the end.
*/
if ((*s == '\r') && (*(s + 1) == '\n')) {
s += 2;
} else {
if (ippr_ftp_debug > 1)
printf("ippr_ftp_pasv:missing %s", "cr-lf\n");
return 0;
}
a6 = a5 & 0xff;
a5 >>= 8;
/*
* Calculate new address parts for 227 reply
*/
if (nat->nat_dir == NAT_INBOUND) {
data_ip = nat->nat_outip.s_addr;
a1 = ntohl(data_ip);
} else
data_ip = htonl(a1);
a2 = (a1 >> 16) & 0xff;
a3 = (a1 >> 8) & 0xff;
a4 = a1 & 0xff;
a1 >>= 24;
#if defined(SNPRINTF) && defined(_KERNEL)
SNPRINTF(newbuf, sizeof(newbuf), "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
"227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
a5, a6, brackets[1]);
#else
(void) sprintf(newbuf, "%s %s%u,%u,%u,%u,%u,%u%s\r\n",
"227 Entering Passive Mode", brackets[0], a1, a2, a3, a4,
a5, a6, brackets[1]);
#endif
return ippr_ftp_pasvreply(fin, ip, nat, f, (a5 << 8 | a6),
newbuf, s, data_ip);
}
int ippr_ftp_pasvreply(fin, ip, nat, f, port, newmsg, s, data_ip)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpside_t *f;
u_int port;
char *newmsg;
char *s;
u_int data_ip;
{
int inc, off, nflags, sflags;
tcphdr_t *tcp, tcph, *tcp2;
struct in_addr swip, swip2;
struct in_addr data_addr;
size_t nlen, olen;
fr_info_t fi;
nat_t *nat2;
mb_t *m;
m = fin->fin_m;
tcp = (tcphdr_t *)fin->fin_dp;
off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
data_addr.s_addr = data_ip;
tcp2 = &tcph;
inc = 0;
olen = s - f->ftps_rptr;
nlen = strlen(newmsg);
inc = nlen - olen;
if ((inc + ip->ip_len) > 65535) {
if (ippr_ftp_debug > 0)
printf("ippr_ftp_pasv:inc(%d) + ip->ip_len > 65535\n",
inc);
return 0;
}
#if !defined(_KERNEL)
bcopy(newmsg, MTOD(m, char *) + off, nlen);
#else
# if defined(MENTAT)
if (inc < 0)
(void)adjmsg(m, inc);
# else /* defined(MENTAT) */
/*
* m_adj takes care of pkthdr.len, if required and treats inc<0 to
* mean remove -len bytes from the end of the packet.
* The mbuf chain will be extended if necessary by m_copyback().
*/
if (inc < 0)
m_adj(m, inc);
# endif /* defined(MENTAT) */
#endif /* !defined(_KERNEL) */
COPYBACK(m, off, nlen, newmsg);
if (inc != 0) {
ip->ip_len += inc;
fin->fin_dlen += inc;
fin->fin_plen += inc;
}
/*
* Add skeleton NAT entry for connection which will come back the
* other way.
*/
bcopy((char *)fin, (char *)&fi, sizeof(fi));
fi.fin_state = NULL;
fi.fin_nat = NULL;
fi.fin_flx |= FI_IGNORE;
fi.fin_data[0] = 0;
fi.fin_data[1] = port;
nflags = IPN_TCP|SI_W_SPORT;
if (ippr_ftp_pasvrdr && f->ftps_ifp)
nflags |= SI_W_DPORT;
if (nat->nat_dir == NAT_OUTBOUND)
nat2 = nat_outlookup(&fi, nflags|NAT_SEARCH,
nat->nat_p, nat->nat_inip, nat->nat_oip);
else
nat2 = nat_inlookup(&fi, nflags|NAT_SEARCH,
nat->nat_p, nat->nat_inip, nat->nat_oip);
if (nat2 == NULL) {
int slen;
slen = ip->ip_len;
ip->ip_len = fin->fin_hlen + sizeof(*tcp2);
bzero((char *)tcp2, sizeof(*tcp2));
tcp2->th_win = htons(8192);
tcp2->th_sport = 0; /* XXX - fake it for nat_new */
TCP_OFF_A(tcp2, 5);
tcp2->th_flags = TH_SYN;
fi.fin_data[1] = port;
fi.fin_dlen = sizeof(*tcp2);
tcp2->th_dport = htons(port);
fi.fin_data[0] = 0;
fi.fin_dp = (char *)tcp2;
fi.fin_plen = fi.fin_hlen + sizeof(*tcp);
fi.fin_fr = &ftppxyfr;
fi.fin_out = nat->nat_dir;
fi.fin_flx &= FI_LOWTTL|FI_FRAG|FI_TCPUDP|FI_OPTIONS|FI_IGNORE;
swip = ip->ip_src;
swip2 = ip->ip_dst;
if (nat->nat_dir == NAT_OUTBOUND) {
fi.fin_fi.fi_daddr = data_addr.s_addr;
fi.fin_fi.fi_saddr = nat->nat_inip.s_addr;
ip->ip_dst = data_addr;
ip->ip_src = nat->nat_inip;
} else if (nat->nat_dir == NAT_INBOUND) {
fi.fin_fi.fi_saddr = nat->nat_oip.s_addr;
fi.fin_fi.fi_daddr = nat->nat_outip.s_addr;
ip->ip_src = nat->nat_oip;
ip->ip_dst = nat->nat_outip;
}
sflags = nflags;
nflags |= NAT_SLAVE;
if (nat->nat_dir == NAT_INBOUND)
nflags |= NAT_NOTRULEPORT;
nat2 = nat_new(&fi, nat->nat_ptr, NULL, nflags, nat->nat_dir);
if (nat2 != NULL) {
(void) nat_proto(&fi, nat2, IPN_TCP);
nat_update(&fi, nat2, nat->nat_ptr);
fi.fin_ifp = NULL;
if (nat->nat_dir == NAT_INBOUND) {
fi.fin_fi.fi_daddr = nat->nat_inip.s_addr;
ip->ip_dst = nat->nat_inip;
}
(void) fr_addstate(&fi, NULL, sflags);
if (fi.fin_state != NULL)
fr_statederef((ipstate_t **)&fi.fin_state);
}
ip->ip_len = slen;
ip->ip_src = swip;
ip->ip_dst = swip2;
}
return inc;
}
int ippr_ftp_server(fin, ip, nat, ftp, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpinfo_t *ftp;
int dlen;
{
char *rptr, *wptr;
ftpside_t *f;
int inc;
inc = 0;
f = &ftp->ftp_side[1];
rptr = f->ftps_rptr;
wptr = f->ftps_wptr;
if (*rptr == ' ')
goto server_cmd_ok;
if (!ISDIGIT(*rptr) || !ISDIGIT(*(rptr + 1)) || !ISDIGIT(*(rptr + 2)))
return 0;
if (ftp->ftp_passok == FTPXY_GO) {
if (!strncmp(rptr, "227 ", 4))
inc = ippr_ftp_pasv(fin, ip, nat, ftp, dlen);
else if (!strncmp(rptr, "229 ", 4))
inc = ippr_ftp_epsv(fin, ip, nat, f, dlen);
} else if (ippr_ftp_insecure && !strncmp(rptr, "227 ", 4)) {
inc = ippr_ftp_pasv(fin, ip, nat, ftp, dlen);
} else if (ippr_ftp_insecure && !strncmp(rptr, "229 ", 4)) {
inc = ippr_ftp_epsv(fin, ip, nat, f, dlen);
} else if (*rptr == '5' || *rptr == '4')
ftp->ftp_passok = FTPXY_INIT;
else if (ftp->ftp_incok) {
if (*rptr == '3') {
if (ftp->ftp_passok == FTPXY_ACCT_1)
ftp->ftp_passok = FTPXY_GO;
else
ftp->ftp_passok++;
} else if (*rptr == '2') {
switch (ftp->ftp_passok)
{
case FTPXY_USER_1 :
case FTPXY_USER_2 :
case FTPXY_PASS_1 :
case FTPXY_PASS_2 :
case FTPXY_ACCT_1 :
ftp->ftp_passok = FTPXY_GO;
break;
default :
ftp->ftp_passok += 3;
break;
}
}
}
server_cmd_ok:
ftp->ftp_incok = 0;
while ((*rptr++ != '\n') && (rptr < wptr))
;
f->ftps_rptr = rptr;
return inc;
}
/*
* Look to see if the buffer starts with something which we recognise as
* being the correct syntax for the FTP protocol.
*/
int ippr_ftp_client_valid(ftps, buf, len)
ftpside_t *ftps;
char *buf;
size_t len;
{
register char *s, c, pc;
register size_t i = len;
char cmd[5];
s = buf;
if (ftps->ftps_junk == 1)
return 1;
if (i < 5) {
if (ippr_ftp_debug > 3)
printf("ippr_ftp_client_valid:i(%d) < 5\n", (int)i);
return 2;
}
i--;
c = *s++;
if (ISALPHA(c)) {
cmd[0] = TOUPPER(c);
c = *s++;
i--;
if (ISALPHA(c)) {
cmd[1] = TOUPPER(c);
c = *s++;
i--;
if (ISALPHA(c)) {
cmd[2] = TOUPPER(c);
c = *s++;
i--;
if (ISALPHA(c)) {
cmd[3] = TOUPPER(c);
c = *s++;
i--;
if ((c != ' ') && (c != '\r'))
goto bad_client_command;
} else if ((c != ' ') && (c != '\r'))
goto bad_client_command;
} else
goto bad_client_command;
} else
goto bad_client_command;
} else {
bad_client_command:
if (ippr_ftp_debug > 3)
printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
"ippr_ftp_client_valid",
ftps->ftps_junk, (int)len, (int)i, c,
(int)len, (int)len, buf);
return 1;
}
for (; i; i--) {
pc = c;
c = *s++;
if ((pc == '\r') && (c == '\n')) {
cmd[4] = '\0';
if (!strcmp(cmd, "PASV"))
ftps->ftps_cmds = FTPXY_C_PASV;
else
ftps->ftps_cmds = 0;
return 0;
}
}
#if !defined(_KERNEL)
printf("ippr_ftp_client_valid:junk after cmd[%*.*s]\n",
(int)len, (int)len, buf);
#endif
return 2;
}
int ippr_ftp_server_valid(ftps, buf, len)
ftpside_t *ftps;
char *buf;
size_t len;
{
register char *s, c, pc;
register size_t i = len;
int cmd;
s = buf;
cmd = 0;
if (ftps->ftps_junk == 1)
return 1;
if (i < 5) {
if (ippr_ftp_debug > 3)
printf("ippr_ftp_servert_valid:i(%d) < 5\n", (int)i);
return 2;
}
c = *s++;
i--;
if (c == ' ')
goto search_eol;
if (ISDIGIT(c)) {
cmd = (c - '0') * 100;
c = *s++;
i--;
if (ISDIGIT(c)) {
cmd += (c - '0') * 10;
c = *s++;
i--;
if (ISDIGIT(c)) {
cmd += (c - '0');
c = *s++;
i--;
if ((c != '-') && (c != ' '))
goto bad_server_command;
} else
goto bad_server_command;
} else
goto bad_server_command;
} else {
bad_server_command:
if (ippr_ftp_debug > 3)
printf("%s:bad:junk %d len %d/%d c 0x%x buf [%*.*s]\n",
"ippr_ftp_server_valid",
ftps->ftps_junk, (int)len, (int)i,
c, (int)len, (int)len, buf);
return 1;
}
search_eol:
for (; i; i--) {
pc = c;
c = *s++;
if ((pc == '\r') && (c == '\n')) {
ftps->ftps_cmds = cmd;
return 0;
}
}
if (ippr_ftp_debug > 3)
printf("ippr_ftp_server_valid:junk after cmd[%*.*s]\n",
(int)len, (int)len, buf);
return 2;
}
int ippr_ftp_valid(ftp, side, buf, len)
ftpinfo_t *ftp;
int side;
char *buf;
size_t len;
{
ftpside_t *ftps;
int ret;
ftps = &ftp->ftp_side[side];
if (side == 0)
ret = ippr_ftp_client_valid(ftps, buf, len);
else
ret = ippr_ftp_server_valid(ftps, buf, len);
return ret;
}
/*
* For map rules, the following applies:
* rv == 0 for outbound processing,
* rv == 1 for inbound processing.
* For rdr rules, the following applies:
* rv == 0 for inbound processing,
* rv == 1 for outbound processing.
*/
int ippr_ftp_process(fin, nat, ftp, rv)
fr_info_t *fin;
nat_t *nat;
ftpinfo_t *ftp;
int rv;
{
int mlen, len, off, inc, i, sel, sel2, ok, ackoff, seqoff;
char *rptr, *wptr, *s;
u_32_t thseq, thack;
ap_session_t *aps;
ftpside_t *f, *t;
tcphdr_t *tcp;
ip_t *ip;
mb_t *m;
m = fin->fin_m;
ip = fin->fin_ip;
tcp = (tcphdr_t *)fin->fin_dp;
off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
f = &ftp->ftp_side[rv];
t = &ftp->ftp_side[1 - rv];
thseq = ntohl(tcp->th_seq);
thack = ntohl(tcp->th_ack);
#ifdef __sgi
mlen = fin->fin_plen - off;
#else
mlen = MSGDSIZE(m) - off;
#endif
if (ippr_ftp_debug > 4)
printf("ippr_ftp_process: mlen %d\n", mlen);
if ((mlen == 0) && ((tcp->th_flags & TH_OPENING) == TH_OPENING)) {
f->ftps_seq[0] = thseq + 1;
t->ftps_seq[0] = thack;
return 0;
} else if (mlen < 0) {
return 0;
}
aps = nat->nat_aps;
sel = aps->aps_sel[1 - rv];
sel2 = aps->aps_sel[rv];
if (rv == 0) {
seqoff = aps->aps_seqoff[sel];
if (aps->aps_seqmin[sel] > seqoff + thseq)
seqoff = aps->aps_seqoff[!sel];
ackoff = aps->aps_ackoff[sel2];
if (aps->aps_ackmin[sel2] > ackoff + thack)
ackoff = aps->aps_ackoff[!sel2];
} else {
seqoff = aps->aps_ackoff[sel];
if (ippr_ftp_debug > 2)
printf("seqoff %d thseq %x ackmin %x\n", seqoff, thseq,
aps->aps_ackmin[sel]);
if (aps->aps_ackmin[sel] > seqoff + thseq)
seqoff = aps->aps_ackoff[!sel];
ackoff = aps->aps_seqoff[sel2];
if (ippr_ftp_debug > 2)
printf("ackoff %d thack %x seqmin %x\n", ackoff, thack,
aps->aps_seqmin[sel2]);
if (ackoff > 0) {
if (aps->aps_seqmin[sel2] > ackoff + thack)
ackoff = aps->aps_seqoff[!sel2];
} else {
if (aps->aps_seqmin[sel2] > thack)
ackoff = aps->aps_seqoff[!sel2];
}
}
if (ippr_ftp_debug > 2) {
printf("%s: %x seq %x/%d ack %x/%d len %d/%d off %d\n",
rv ? "IN" : "OUT", tcp->th_flags, thseq, seqoff,
thack, ackoff, mlen, fin->fin_plen, off);
printf("sel %d seqmin %x/%x offset %d/%d\n", sel,
aps->aps_seqmin[sel], aps->aps_seqmin[sel2],
aps->aps_seqoff[sel], aps->aps_seqoff[sel2]);
printf("sel %d ackmin %x/%x offset %d/%d\n", sel2,
aps->aps_ackmin[sel], aps->aps_ackmin[sel2],
aps->aps_ackoff[sel], aps->aps_ackoff[sel2]);
}
/*
* XXX - Ideally, this packet should get dropped because we now know
* that it is out of order (and there is no real danger in doing so
* apart from causing packets to go through here ordered).
*/
if (ippr_ftp_debug > 2) {
printf("rv %d t:seq[0] %x seq[1] %x %d/%d\n",
rv, t->ftps_seq[0], t->ftps_seq[1], seqoff, ackoff);
}
ok = 0;
if (t->ftps_seq[0] == 0) {
t->ftps_seq[0] = thack;
ok = 1;
} else {
if (ackoff == 0) {
if (t->ftps_seq[0] == thack)
ok = 1;
else if (t->ftps_seq[1] == thack) {
t->ftps_seq[0] = thack;
ok = 1;
}
} else {
if (t->ftps_seq[0] + ackoff == thack)
ok = 1;
else if (t->ftps_seq[0] == thack + ackoff)
ok = 1;
else if (t->ftps_seq[1] + ackoff == thack) {
t->ftps_seq[0] = thack - ackoff;
ok = 1;
} else if (t->ftps_seq[1] == thack + ackoff) {
t->ftps_seq[0] = thack - ackoff;
ok = 1;
}
}
}
if (ippr_ftp_debug > 2) {
if (!ok)
printf("%s ok\n", "not");
}
if (!mlen) {
if (t->ftps_seq[0] + ackoff != thack) {
if (ippr_ftp_debug > 1) {
printf("%s:seq[0](%x) + (%x) != (%x)\n",
"ippr_ftp_process", t->ftps_seq[0],
ackoff, thack);
}
return APR_ERR(1);
}
if (ippr_ftp_debug > 2) {
printf("ippr_ftp_process:f:seq[0] %x seq[1] %x\n",
f->ftps_seq[0], f->ftps_seq[1]);
}
if (tcp->th_flags & TH_FIN) {
if (thseq == f->ftps_seq[1]) {
f->ftps_seq[0] = f->ftps_seq[1] - seqoff;
f->ftps_seq[1] = thseq + 1 - seqoff;
} else {
if (ippr_ftp_debug > 1) {
printf("FIN: thseq %x seqoff %d ftps_seq %x %x\n",
thseq, seqoff, f->ftps_seq[0], f->ftps_seq[1]);
}
return APR_ERR(1);
}
}
f->ftps_len = 0;
return 0;
}
ok = 0;
if ((thseq == f->ftps_seq[0]) || (thseq == f->ftps_seq[1])) {
ok = 1;
/*
* Retransmitted data packet.
*/
} else if ((thseq + mlen == f->ftps_seq[0]) ||
(thseq + mlen == f->ftps_seq[1])) {
ok = 1;
}
if (ok == 0) {
inc = thseq - f->ftps_seq[0];
if (ippr_ftp_debug > 1) {
printf("inc %d sel %d rv %d\n", inc, sel, rv);
printf("th_seq %x ftps_seq %x/%x\n",
thseq, f->ftps_seq[0], f->ftps_seq[1]);
printf("ackmin %x ackoff %d\n", aps->aps_ackmin[sel],
aps->aps_ackoff[sel]);
printf("seqmin %x seqoff %d\n", aps->aps_seqmin[sel],
aps->aps_seqoff[sel]);
}
return APR_ERR(1);
}
inc = 0;
rptr = f->ftps_rptr;
wptr = f->ftps_wptr;
f->ftps_seq[0] = thseq;
f->ftps_seq[1] = f->ftps_seq[0] + mlen;
f->ftps_len = mlen;
while (mlen > 0) {
len = MIN(mlen, sizeof(f->ftps_buf) - (wptr - rptr));
COPYDATA(m, off, len, wptr);
mlen -= len;
off += len;
wptr += len;
if (ippr_ftp_debug > 3)
printf("%s:len %d/%d off %d wptr %lx junk %d [%*.*s]\n",
"ippr_ftp_process",
len, mlen, off, (u_long)wptr, f->ftps_junk,
len, len, rptr);
f->ftps_wptr = wptr;
if (f->ftps_junk != 0) {
i = f->ftps_junk;
f->ftps_junk = ippr_ftp_valid(ftp, rv, rptr,
wptr - rptr);
if (ippr_ftp_debug > 5)
printf("%s:junk %d -> %d\n",
"ippr_ftp_process", i, f->ftps_junk);
if (f->ftps_junk != 0) {
if (wptr - rptr == sizeof(f->ftps_buf)) {
if (ippr_ftp_debug > 4)
printf("%s:full buffer\n",
"ippr_ftp_process");
f->ftps_rptr = f->ftps_buf;
f->ftps_wptr = f->ftps_buf;
rptr = f->ftps_rptr;
wptr = f->ftps_wptr;
/*
* Because we throw away data here that
* we would otherwise parse, set the
* junk flag to indicate just ignore
* any data upto the next CRLF.
*/
f->ftps_junk = 1;
continue;
}
}
}
while ((f->ftps_junk == 0) && (wptr > rptr)) {
len = wptr - rptr;
f->ftps_junk = ippr_ftp_valid(ftp, rv, rptr, len);
if (ippr_ftp_debug > 3) {
printf("%s=%d len %d rv %d ptr %lx/%lx ",
"ippr_ftp_valid",
f->ftps_junk, len, rv, (u_long)rptr,
(u_long)wptr);
printf("buf [%*.*s]\n", len, len, rptr);
}
if (f->ftps_junk == 0) {
f->ftps_rptr = rptr;
if (rv)
inc += ippr_ftp_server(fin, ip, nat,
ftp, len);
else
inc += ippr_ftp_client(fin, ip, nat,
ftp, len);
rptr = f->ftps_rptr;
wptr = f->ftps_wptr;
}
}
/*
* Off to a bad start so lets just forget about using the
* ftp proxy for this connection.
*/
if ((f->ftps_cmds == 0) && (f->ftps_junk == 1)) {
/* f->ftps_seq[1] += inc; */
if (ippr_ftp_debug > 1)
printf("%s:cmds == 0 junk == 1\n",
"ippr_ftp_process");
return APR_ERR(2);
}
if ((f->ftps_junk != 0) && (rptr < wptr)) {
for (s = rptr; s < wptr; s++) {
if ((*s == '\r') && (s + 1 < wptr) &&
(*(s + 1) == '\n')) {
rptr = s + 2;
f->ftps_junk = 0;
break;
}
}
}
if (rptr == wptr) {
rptr = wptr = f->ftps_buf;
} else {
/*
* Compact the buffer back to the start. The junk
* flag should already be set and because we're not
* throwing away any data, it is preserved from its
* current state.
*/
if (rptr > f->ftps_buf) {
bcopy(rptr, f->ftps_buf, len);
wptr -= rptr - f->ftps_buf;
rptr = f->ftps_buf;
}
}
f->ftps_rptr = rptr;
f->ftps_wptr = wptr;
}
/* f->ftps_seq[1] += inc; */
if (tcp->th_flags & TH_FIN)
f->ftps_seq[1]++;
if (ippr_ftp_debug > 3) {
#ifdef __sgi
mlen = fin->fin_plen;
#else
mlen = MSGDSIZE(m);
#endif
mlen -= off;
printf("ftps_seq[1] = %x inc %d len %d\n",
f->ftps_seq[1], inc, mlen);
}
f->ftps_rptr = rptr;
f->ftps_wptr = wptr;
return APR_INC(inc);
}
int ippr_ftp_out(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ftpinfo_t *ftp;
int rev;
ftp = aps->aps_data;
if (ftp == NULL)
return 0;
rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
if (ftp->ftp_side[1 - rev].ftps_ifp == NULL)
ftp->ftp_side[1 - rev].ftps_ifp = fin->fin_ifp;
return ippr_ftp_process(fin, nat, ftp, rev);
}
int ippr_ftp_in(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ftpinfo_t *ftp;
int rev;
ftp = aps->aps_data;
if (ftp == NULL)
return 0;
rev = (nat->nat_dir == NAT_OUTBOUND) ? 0 : 1;
if (ftp->ftp_side[rev].ftps_ifp == NULL)
ftp->ftp_side[rev].ftps_ifp = fin->fin_ifp;
return ippr_ftp_process(fin, nat, ftp, 1 - rev);
}
/*
* ippr_ftp_atoi - implement a version of atoi which processes numbers in
* pairs separated by commas (which are expected to be in the range 0 - 255),
* returning a 16 bit number combining either side of the , as the MSB and
* LSB.
*/
u_short ippr_ftp_atoi(ptr)
char **ptr;
{
register char *s = *ptr, c;
register u_char i = 0, j = 0;
while (((c = *s++) != '\0') && ISDIGIT(c)) {
i *= 10;
i += c - '0';
}
if (c != ',') {
*ptr = NULL;
return 0;
}
while (((c = *s++) != '\0') && ISDIGIT(c)) {
j *= 10;
j += c - '0';
}
*ptr = s;
i &= 0xff;
j &= 0xff;
return (i << 8) | j;
}
int ippr_ftp_epsv(fin, ip, nat, f, dlen)
fr_info_t *fin;
ip_t *ip;
nat_t *nat;
ftpside_t *f;
int dlen;
{
char newbuf[IPF_FTPBUFSZ];
char *s;
u_short ap = 0;
#define EPSV_REPLEN 33
/*
* Check for EPSV reply message.
*/
if (dlen < IPF_MIN229LEN)
return (0);
else if (strncmp(f->ftps_rptr,
"229 Entering Extended Passive Mode", EPSV_REPLEN))
return (0);
/*
* Skip the EPSV command + space
*/
s = f->ftps_rptr + 33;
while (*s && !ISDIGIT(*s))
s++;
/*
* As per RFC 2428, there are no addres components in the EPSV
* response. So we'll go straight to getting the port.
*/
while (*s && ISDIGIT(*s)) {
ap *= 10;
ap += *s++ - '0';
}
if (!*s)
return 0;
if (*s == '|')
s++;
if (*s == ')')
s++;
if (*s == '\n')
s--;
/*
* check for CR-LF at the end.
*/
if ((*s == '\r') && (*(s + 1) == '\n')) {
s += 2;
} else
return 0;
#if defined(SNPRINTF) && defined(_KERNEL)
SNPRINTF(newbuf, sizeof(newbuf), "%s (|||%u|)\r\n",
"229 Entering Extended Passive Mode", ap);
#else
(void) sprintf(newbuf, "%s (|||%u|)\r\n",
"229 Entering Extended Passive Mode", ap);
#endif
return ippr_ftp_pasvreply(fin, ip, nat, f, (u_int)ap, newbuf, s,
ip->ip_src.s_addr);
}