freebsd-skq/ip_irc_pxy.c
Cy Schubert f27f47054d As per the developers handbook (5.3.1 step 1), prepare the vendor trees for
import of new ipfilter vendor sources by flattening them.

To keep the tags consistent with dist, the tags are also flattened.

Approved by:	glebius (Mentor)
2013-07-19 05:41:57 +00:00

436 lines
8.0 KiB
C

/* $NetBSD$ */
/*
* Copyright (C) 2000-2003 Darren Reed
*
* See the IPFILTER.LICENCE file for details on licencing.
*
* Id: ip_irc_pxy.c,v 2.39.2.4 2005/02/04 10:22:55 darrenr Exp
*/
#define IPF_IRC_PROXY
#define IPF_IRCBUFSZ 96 /* This *MUST* be >= 64! */
int ippr_irc_init __P((void));
void ippr_irc_fini __P((void));
int ippr_irc_new __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_irc_out __P((fr_info_t *, ap_session_t *, nat_t *));
int ippr_irc_send __P((fr_info_t *, nat_t *));
int ippr_irc_complete __P((ircinfo_t *, char *, size_t));
u_short ipf_irc_atoi __P((char **));
static frentry_t ircnatfr;
int irc_proxy_init = 0;
/*
* Initialize local structures.
*/
int ippr_irc_init()
{
bzero((char *)&ircnatfr, sizeof(ircnatfr));
ircnatfr.fr_ref = 1;
ircnatfr.fr_flags = FR_INQUE|FR_PASS|FR_QUICK|FR_KEEPSTATE;
MUTEX_INIT(&ircnatfr.fr_lock, "IRC proxy rule lock");
irc_proxy_init = 1;
return 0;
}
void ippr_irc_fini()
{
if (irc_proxy_init == 1) {
MUTEX_DESTROY(&ircnatfr.fr_lock);
irc_proxy_init = 0;
}
}
char *ippr_irc_dcctypes[] = {
"CHAT ", /* CHAT chat ipnumber portnumber */
"SEND ", /* SEND filename ipnumber portnumber */
"MOVE ",
"TSEND ",
"SCHAT ",
NULL,
};
/*
* :A PRIVMSG B :^ADCC CHAT chat 0 0^A\r\n
* PRIVMSG B ^ADCC CHAT chat 0 0^A\r\n
*/
int ippr_irc_complete(ircp, buf, len)
ircinfo_t *ircp;
char *buf;
size_t len;
{
register char *s, c;
register size_t i;
u_32_t l;
int j, k;
ircp->irc_ipnum = 0;
ircp->irc_port = 0;
if (len < 31)
return 0;
s = buf;
c = *s++;
i = len - 1;
if ((c != ':') && (c != 'P'))
return 0;
if (c == ':') {
/*
* Loosely check that the source is a nickname of some sort
*/
s++;
c = *s;
ircp->irc_snick = s;
if (!ISALPHA(c))
return 0;
i--;
for (c = *s; !ISSPACE(c) && (i > 0); i--)
c = *s++;
if (i < 31)
return 0;
if (c != 'P')
return 0;
} else
ircp->irc_snick = NULL;
/*
* Check command string
*/
if (strncmp(s, "PRIVMSG ", 8))
return 0;
i -= 8;
s += 8;
c = *s;
ircp->irc_dnick = s;
/*
* Loosely check that the destination is a nickname of some sort
*/
if (!ISALPHA(c))
return 0;
for (; !ISSPACE(c) && (i > 0); i--)
c = *s++;
if (i < 20)
return 0;
s++,
i--;
/*
* Look for a ^A to start the DCC
*/
c = *s;
if (c == ':') {
s++;
c = *s;
}
if (strncmp(s, "\001DCC ", 4))
return 0;
i -= 4;
s += 4;
/*
* Check for a recognised DCC command
*/
for (j = 0, k = 0; ippr_irc_dcctypes[j]; j++) {
k = MIN(strlen(ippr_irc_dcctypes[j]), i);
if (!strncmp(ippr_irc_dcctypes[j], s, k))
break;
}
if (!ippr_irc_dcctypes[j])
return 0;
ircp->irc_type = s;
i -= k;
s += k;
if (i < 11)
return 0;
/*
* Check for the arg
*/
c = *s;
if (ISSPACE(c))
return 0;
ircp->irc_arg = s;
for (; (c != ' ') && (c != '\001') && (i > 0); i--)
c = *s++;
if (c == '\001') /* In reality a ^A can quote another ^A...*/
return 0;
if (i < 5)
return 0;
s++;
i--;
c = *s;
if (!ISDIGIT(c))
return 0;
ircp->irc_addr = s;
/*
* Get the IP#
*/
for (l = 0; ISDIGIT(c) && (i > 0); i--) {
l *= 10;
l += c - '0';
c = *s++;
}
if (i < 4)
return 0;
if (c != ' ')
return 0;
ircp->irc_ipnum = l;
s++;
i--;
c = *s;
if (!ISDIGIT(c))
return 0;
/*
* Get the port#
*/
for (l = 0; ISDIGIT(c) && (i > 0); i--) {
l *= 10;
l += c - '0';
c = *s++;
}
if (i < 3)
return 0;
if (strncmp(s, "\001\r\n", 3))
return 0;
s += 3;
ircp->irc_len = s - buf;
ircp->irc_port = l;
return 1;
}
int ippr_irc_new(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
ircinfo_t *irc;
KMALLOC(irc, ircinfo_t *);
if (irc == NULL)
return -1;
fin = fin; /* LINT */
nat = nat; /* LINT */
aps->aps_data = irc;
aps->aps_psiz = sizeof(ircinfo_t);
bzero((char *)irc, sizeof(*irc));
return 0;
}
int ippr_irc_send(fin, nat)
fr_info_t *fin;
nat_t *nat;
{
char ctcpbuf[IPF_IRCBUFSZ], newbuf[IPF_IRCBUFSZ];
tcphdr_t *tcp, tcph, *tcp2 = &tcph;
int off, inc = 0, i, dlen;
size_t nlen = 0, olen;
struct in_addr swip;
u_short a5, sp;
ircinfo_t *irc;
fr_info_t fi;
nat_t *nat2;
u_int a1;
ip_t *ip;
mb_t *m;
#ifdef MENTAT
mb_t *m1;
#endif
m = fin->fin_m;
ip = fin->fin_ip;
tcp = (tcphdr_t *)fin->fin_dp;
bzero(ctcpbuf, sizeof(ctcpbuf));
off = (char *)tcp - (char *)ip + (TCP_OFF(tcp) << 2) + fin->fin_ipoff;
#ifdef __sgi
dlen = fin->fin_plen - off;
#else
dlen = MSGDSIZE(m) - off;
#endif
if (dlen <= 0)
return 0;
COPYDATA(m, off, MIN(sizeof(ctcpbuf), dlen), ctcpbuf);
if (dlen <= 0)
return 0;
ctcpbuf[sizeof(ctcpbuf) - 1] = '\0';
*newbuf = '\0';
irc = nat->nat_aps->aps_data;
if (ippr_irc_complete(irc, ctcpbuf, dlen) == 0)
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.
*/
if (irc->irc_ipnum != ntohl(nat->nat_inip.s_addr))
return 0;
a5 = irc->irc_port;
/*
* Calculate new address parts for the DCC command
*/
a1 = ntohl(ip->ip_src.s_addr);
olen = irc->irc_len;
i = irc->irc_addr - ctcpbuf;
i++;
(void) strncpy(newbuf, ctcpbuf, i);
/* DO NOT change these! */
#if defined(SNPRINTF) && defined(KERNEL)
SNPRINTF(newbuf, sizeof(newbuf) - i, "%u %u\001\r\n", a1, a5);
#else
(void) sprintf(newbuf, "%u %u\001\r\n", a1, a5);
#endif
nlen = strlen(newbuf);
inc = nlen - olen;
if ((inc + ip->ip_len) > 65535)
return 0;
#ifdef MENTAT
for (m1 = m; m1->b_cont; m1 = m1->b_cont)
;
if ((inc > 0) && (m1->b_datap->db_lim - m1->b_wptr < inc)) {
mblk_t *nm;
/* alloc enough to keep same trailer space for lower driver */
nm = allocb(nlen, BPRI_MED);
PANIC((!nm),("ippr_irc_out: allocb failed"));
nm->b_band = m1->b_band;
nm->b_wptr += nlen;
m1->b_wptr -= olen;
PANIC((m1->b_wptr < m1->b_rptr),
("ippr_irc_out: cannot handle fragmented data block"));
linkb(m1, nm);
} else {
# if SOLARIS && defined(ICK_VALID)
if (m1->b_datap->db_struiolim == m1->b_wptr)
m1->b_datap->db_struiolim += inc;
m1->b_datap->db_struioflag &= ~STRUIO_IP;
# endif
m1->b_wptr += inc;
}
#else
if (inc < 0)
m_adj(m, inc);
/* the mbuf chain will be extended if necessary by m_copyback() */
#endif
COPYBACK(m, off, nlen, newbuf);
if (inc != 0) {
#if defined(MENTAT) || defined(__sgi)
register u_32_t sum1, sum2;
sum1 = ip->ip_len;
sum2 = ip->ip_len + inc;
/* Because ~1 == -2, We really need ~1 == -1 */
if (sum1 > sum2)
sum2--;
sum2 -= sum1;
sum2 = (sum2 & 0xffff) + (sum2 >> 16);
fix_outcksum(fin, &ip->ip_sum, sum2);
#endif
ip->ip_len += inc;
}
/*
* Add skeleton NAT entry for connection which will come back the
* other way.
*/
sp = htons(a5);
/*
* Don't allow the PORT command to specify a port < 1024 due to
* security crap.
*/
if (ntohs(sp) < 1024)
return 0;
/*
* 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((caddr_t)fin, (caddr_t)&fi, sizeof(fi));
fi.fin_data[0] = sp;
fi.fin_data[1] = fin->fin_data[1];
nat2 = nat_outlookup(fin, IPN_TCP, nat->nat_p, nat->nat_inip,
ip->ip_dst);
if (nat2 == NULL) {
bcopy((caddr_t)fin, (caddr_t)&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 */
fi.fin_state = NULL;
fi.fin_nat = NULL;
fi.fin_data[0] = ntohs(sp);
fi.fin_data[1] = 0;
fi.fin_dp = (char *)tcp2;
fi.fin_fr = &ircnatfr;
fi.fin_dlen = sizeof(*tcp2);
fi.fin_plen = fi.fin_hlen + sizeof(*tcp2);
swip = ip->ip_src;
ip->ip_src = nat->nat_inip;
nat2 = nat_new(&fi, nat->nat_ptr, NULL,
NAT_SLAVE|IPN_TCP|SI_W_DPORT, NAT_OUTBOUND);
if (nat2 != NULL) {
(void) nat_proto(&fi, nat2, 0);
nat_update(&fi, nat2, nat2->nat_ptr);
(void) fr_addstate(&fi, NULL, SI_W_DPORT);
if (fi.fin_state != NULL)
fr_statederef(&fi, (ipstate_t **)&fi.fin_state);
}
ip->ip_src = swip;
}
return inc;
}
int ippr_irc_out(fin, aps, nat)
fr_info_t *fin;
ap_session_t *aps;
nat_t *nat;
{
aps = aps; /* LINT */
return ippr_irc_send(fin, nat);
}