From a93925894facc20de4d8d36bcb61fc349047c73f Mon Sep 17 00:00:00 2001
From: darrenr <darrenr@FreeBSD.org>
Date: Sun, 25 May 1997 15:50:46 +0000
Subject: Import version 3.2alpha7

---
 sys/netinet/ip_ftp_pxy.c | 204 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 204 insertions(+)
 create mode 100644 sys/netinet/ip_ftp_pxy.c

(limited to 'sys/netinet/ip_ftp_pxy.c')

diff --git a/sys/netinet/ip_ftp_pxy.c b/sys/netinet/ip_ftp_pxy.c
new file mode 100644
index 0000000..48196e9
--- /dev/null
+++ b/sys/netinet/ip_ftp_pxy.c
@@ -0,0 +1,204 @@
+/*
+ * Simple FTP transparent proxy for in-kernel.
+ */
+
+#define	isdigit(x)	((x) >= '0' && (x) <= '9')
+
+#define	IPF_FTP_PROXY
+
+#define	IPF_MINPORTLEN	18
+#define	IPF_MAXPORTLEN	30
+
+
+int ippr_ftp_init(fin, ip, tcp, aps, nat)
+fr_info_t *fin;
+ip_t *ip;
+tcphdr_t *tcp;
+ap_session_t *aps;
+nat_t *nat;
+{
+	aps->aps_sport = tcp->th_sport;
+	aps->aps_dport = tcp->th_dport;
+	return 0;
+}
+
+
+int ippr_ftp_in(fin, ip, tcp, aps, nat)
+fr_info_t *fin;
+ip_t *ip;
+tcphdr_t *tcp;
+ap_session_t *aps;
+nat_t *nat;
+{
+	int	ch = 0;
+	u_long	sum1, sum2;
+
+	if (tcp->th_dport != aps->aps_dport) {
+		sum2 = (u_long)ntohl(tcp->th_ack);
+		if (aps->aps_seqoff && (sum2 > aps->aps_after)) {
+			sum1 = (u_long)aps->aps_seqoff;
+			tcp->th_ack = htonl(sum2 - sum1);
+			return 2;
+		}
+	}
+	return 0;
+}
+
+
+u_short ipf_ftp_atoi(ptr)
+char **ptr;
+{
+	register char *s = *ptr, c;
+	register u_char i = 0, j = 0;
+
+	while ((c = *s++) && isdigit(c)) {
+		i *= 10;
+		i += c - '0';
+	}
+	if (c != ',') {
+		*ptr = NULL;
+		return 0;
+	}
+	while ((c = *s++) && isdigit(c)) {
+		j *= 10;
+		j += c - '0';
+	}
+	*ptr = s;
+	return (i << 8) | j;
+}
+
+
+int ippr_ftp_out(fin, ip, tcp, aps, nat)
+fr_info_t *fin;
+ip_t *ip;
+tcphdr_t *tcp;
+ap_session_t *aps;
+nat_t *nat;
+{
+	register u_long	sum1, sum2, sumd;
+	char	newbuf[IPF_MAXPORTLEN+1];
+	char	portbuf[IPF_MAXPORTLEN+1], *s, c;
+	int	ch = 0, off = (ip->ip_hl << 2) + (tcp->th_off << 2), len;
+	u_int	a1, a2, a3, a4;
+	u_short	a5, a6;
+	int	olen, dlen, nlen, inc = 0, blen;
+	tcphdr_t tcph, *tcp2 = &tcph;
+	void	*savep;
+	nat_t	*ipn;
+	struct	in_addr	swip;
+#if	SOLARIS
+	mblk_t *m1, *m = *(mblk_t **)fin->fin_mp;
+
+	dlen = m->b_wptr - m->b_rptr - off;
+	blen = m->b_datap->db_lim - m->b_datap->db_base;
+	bzero(portbuf, sizeof(portbuf));
+	copyout_mblk(m, off, portbuf, MIN(sizeof(portbuf), dlen));
+#else
+	struct mbuf *m1, *m = *(struct mbuf **)fin->fin_mp;
+
+	dlen = m->m_len - off;
+# if BSD >= 199306
+	blen = (MLEN - m->m_len) - (m->m_data - m->m_dat);
+# else
+	blen = (MLEN - m->m_len) - m->m_off;
+# endif
+	if (blen < 0)
+		panic("blen < 0 - size of mblk/mbuf wrong");
+	bzero(portbuf, sizeof(portbuf));
+	m_copydata(m, off, MIN(sizeof(portbuf), dlen), portbuf);
+#endif
+	portbuf[IPF_MAXPORTLEN] = '\0';
+	len = MIN(32, dlen);
+
+	if ((len < IPF_MINPORTLEN) || strncmp(portbuf, "PORT ", 5))
+		goto adjust_seqack;
+
+	/*
+	 * Skip the PORT command + space
+	 */
+	s = portbuf + 5;
+	/*
+	 * Pick out the address components, two at a time.
+	 */
+	(void) ipf_ftp_atoi(&s);
+	if (!s)
+		goto adjust_seqack;
+	(void) ipf_ftp_atoi(&s);
+	if (!s)
+		goto adjust_seqack;
+	a5 = ipf_ftp_atoi(&s);
+	if (!s)
+		goto adjust_seqack;
+	/*
+	 * check for CR-LF at the end.
+	 */
+	if (*s != '\n' || *(s - 1) != '\r')
+		goto adjust_seqack;
+	a6 = a5 & 0xff;
+	a5 >>= 8;
+	/*
+	 * Calculate new address parts for PORT command
+	 */
+	a1 = ntohl(ip->ip_src.s_addr);
+	a2 = (a1 >> 16) & 0xff;
+	a3 = (a1 >> 8) & 0xff;
+	a4 = a1 & 0xff;
+	a1 >>= 24;
+	olen = s - portbuf + 1;
+	(void) sprintf(newbuf, "PORT %d,%d,%d,%d,%d,%d\r\n",
+		a1, a2, a3, a4, a5, a6);
+	nlen = strlen(newbuf);
+	inc = nlen - olen;
+	if (tcp->th_seq > aps->aps_after) {
+		aps->aps_after = ntohl(tcp->th_seq) + dlen;
+		aps->aps_seqoff += inc;
+	}
+#if SOLARIS
+	if (inc && dlen)
+		if ((inc < 0) || (blen >= dlen)) {
+			bcopy(m->b_rptr + off,
+			      m->b_rptr + off + aps->aps_seqoff, dlen);
+		}
+	for (m1 = m; m1->b_cont; m1 = m1->b_cont)
+		;
+	m1->b_wptr += inc;
+	copyin_mblk(m, off, newbuf, strlen(newbuf));
+#else
+	if (inc && dlen)
+		if ((inc < 0) || (blen >= dlen)) {
+			bcopy((char *)ip + off,
+			      (char *)ip + off + aps->aps_seqoff, dlen);
+		}
+	m->m_len += inc;
+	m_copyback(m, off, nlen, newbuf);
+#endif
+	ip->ip_len += inc;
+	ch = 1;
+
+	/*
+	 * Add skeleton NAT entry for connection which will come back the
+	 * other way.
+	 */
+	savep = fin->fin_dp;
+	fin->fin_dp = (char *)tcp2;
+	tcp2->th_sport = htons(a5 << 8 | a6);
+	tcp2->th_dport = htons(20);
+	swip = ip->ip_src;
+	ip->ip_src = nat->nat_inip;
+	if ((ipn = nat_new(nat->nat_ptr, ip, fin, IPN_TCP, NAT_OUTBOUND)))
+		ipn->nat_age = fr_defnatage;
+	ip->ip_src = swip;
+	fin->fin_dp = (char *)savep;
+
+adjust_seqack:
+	if (tcp->th_dport == aps->aps_dport) {
+		sum2 = (u_long)ntohl(tcp->th_seq);
+		if (aps->aps_seqoff && (sum2 > aps->aps_after)) {
+			sum1 = (u_long)aps->aps_seqoff;
+			tcp->th_seq = htonl(sum2 + sum1);
+			ch = 1;
+		}
+	}
+
+	return ch ? 2 : 0;
+}
-- 
cgit v1.1