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/* $OpenBSD: ip_rcmd_pxy.c,v 1.5 2001/01/17 04:47:16 fgsch Exp $ */
/*
* $IPFilter: ip_rcmd_pxy.c,v 1.4.2.4 2000/11/01 14:34:20 darrenr Exp $
*/
/*
* Simple RCMD transparent proxy for in-kernel use. For use with the NAT
* code.
*/
#if SOLARIS && defined(_KERNEL)
extern kmutex_t ipf_rw;
#endif
#define isdigit(x) ((x) >= '0' && (x) <= '9')
#define IPF_RCMD_PROXY
int ippr_rcmd_init __P((void));
int ippr_rcmd_new __P((fr_info_t *, ip_t *, ap_session_t *, nat_t *));
int ippr_rcmd_out __P((fr_info_t *, ip_t *, ap_session_t *, nat_t *));
u_short ipf_rcmd_atoi __P((char *));
int ippr_rcmd_portmsg __P((fr_info_t *, ip_t *, ap_session_t *, nat_t *));
static frentry_t rcmdfr;
/*
* RCMD application proxy initialization.
*/
int ippr_rcmd_init()
{
bzero((char *)&rcmdfr, sizeof(rcmdfr));
rcmdfr.fr_ref = 1;
rcmdfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
return 0;
}
/*
* Setup for a new RCMD proxy.
*/
int ippr_rcmd_new(fin, ip, aps, nat)
fr_info_t *fin;
ip_t *ip;
ap_session_t *aps;
nat_t *nat;
{
tcphdr_t *tcp = (tcphdr_t *)fin->fin_dp;
aps->aps_psiz = sizeof(u_32_t);
KMALLOCS(aps->aps_data, u_32_t *, sizeof(u_32_t));
if (aps->aps_data == NULL)
return -1;
*(u_32_t *)aps->aps_data = 0;
aps->aps_sport = tcp->th_sport;
aps->aps_dport = tcp->th_dport;
return 0;
}
/*
* ipf_rcmd_atoi - implement a simple version of atoi
*/
u_short ipf_rcmd_atoi(ptr)
char *ptr;
{
register char *s = ptr, c;
register u_short i = 0;
while ((c = *s++) && isdigit(c)) {
i *= 10;
i += c - '0';
}
return i;
}
int ippr_rcmd_portmsg(fin, ip, aps, nat)
fr_info_t *fin;
ip_t *ip;
ap_session_t *aps;
nat_t *nat;
{
char portbuf[8], *s;
struct in_addr swip;
u_short sp, dp;
int off, dlen;
tcphdr_t *tcp, tcph, *tcp2 = &tcph;
fr_info_t fi;
nat_t *ipn;
mb_t *m;
#if SOLARIS
mb_t *m1;
#endif
tcp = (tcphdr_t *)fin->fin_dp;
if (tcp->th_flags & TH_SYN) {
*(u_32_t *)aps->aps_data = htonl(ntohl(tcp->th_seq) + 1);
return 0;
}
if ((*(u_32_t *)aps->aps_data != 0) &&
(tcp->th_seq != *(u_32_t *)aps->aps_data))
return 0;
off = (ip->ip_hl << 2) + (tcp->th_off << 2);
#if SOLARIS
m = fin->fin_qfm;
dlen = msgdsize(m) - off;
bzero(portbuf, sizeof(portbuf));
copyout_mblk(m, off, MIN(sizeof(portbuf), dlen), portbuf);
#else
m = *(mb_t **)fin->fin_mp;
dlen = mbufchainlen(m) - off;
bzero(portbuf, sizeof(portbuf));
m_copydata(m, off, MIN(sizeof(portbuf), dlen), portbuf);
#endif
portbuf[sizeof(portbuf) - 1] = '\0';
s = portbuf;
sp = ipf_rcmd_atoi(s);
if (!sp)
return 0;
/*
* Add skeleton NAT entry for connection which will come back the
* other way.
*/
sp = htons(sp);
dp = htons(fin->fin_data[1]);
ipn = nat_outlookup(fin->fin_ifp, IPN_TCP, nat->nat_p, nat->nat_inip,
ip->ip_dst, (dp << 16) | sp, 0);
if (ipn == NULL) {
int slen;
slen = ip->ip_len;
ip->ip_len = fin->fin_hlen + sizeof(*tcp);
bcopy((char *)fin, (char *)&fi, sizeof(fi));
bzero((char *)tcp2, sizeof(*tcp2));
tcp2->th_win = htons(8192);
tcp2->th_sport = sp;
tcp2->th_dport = 0; /* XXX - don't specify remote port */
tcp2->th_off = 5;
fi.fin_data[0] = ntohs(sp);
fi.fin_data[1] = 0;
fi.fin_dp = (char *)tcp2;
fi.fin_dlen = sizeof(*tcp2);
swip = ip->ip_src;
ip->ip_src = nat->nat_inip;
ipn = nat_new(nat->nat_ptr, ip, &fi, IPN_TCP|FI_W_DPORT,
NAT_OUTBOUND);
if (ipn != NULL) {
ipn->nat_age = fr_defnatage;
fi.fin_fr = &rcmdfr;
(void) fr_addstate(ip, &fi, FI_W_DPORT);
}
ip->ip_len = slen;
ip->ip_src = swip;
}
return 0;
}
int ippr_rcmd_out(fin, ip, aps, nat)
fr_info_t *fin;
ip_t *ip;
ap_session_t *aps;
nat_t *nat;
{
return ippr_rcmd_portmsg(fin, ip, aps, nat);
}
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