Move files to match FreeBSD layout

1 files changed, 696 insertions, 0 deletions

diff --git a/freebsd/sys/netinet/libalias/alias_ftp.c b/freebsd/sys/netinet/libalias/alias_ftp.c
new file mode 100644
index 00000000..4e8b7177
--- /dev/null
+++ b/freebsd/sys/netinet/libalias/alias_ftp.c
@@ -0,0 +1,696 @@
+#include <freebsd/machine/rtems-bsd-config.h>
+
+/*-
+ * Copyright (c) 2001 Charles Mott <cm@linktel.net>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+    Alias_ftp.c performs special processing for FTP sessions under
+    TCP.  Specifically, when a PORT/EPRT command from the client
+    side or 227/229 reply from the server is sent, it is intercepted
+    and modified.  The address is changed to the gateway machine
+    and an aliasing port is used.
+
+    For this routine to work, the message must fit entirely into a
+    single TCP packet.  This is typically the case, but exceptions
+    can easily be envisioned under the actual specifications.
+
+    Probably the most troubling aspect of the approach taken here is
+    that the new message will typically be a different length, and
+    this causes a certain amount of bookkeeping to keep track of the
+    changes of sequence and acknowledgment numbers, since the client
+    machine is totally unaware of the modification to the TCP stream.
+
+
+    References: RFC 959, RFC 2428.
+
+    Initial version:  August, 1996  (cjm)
+
+    Version 1.6
+	 Brian Somers and Martin Renters identified an IP checksum
+	 error for modified IP packets.
+
+    Version 1.7:  January 9, 1996 (cjm)
+	 Differential checksum computation for change
+	 in IP packet length.
+
+    Version 2.1:  May, 1997 (cjm)
+	 Very minor changes to conform with
+	 local/global/function naming conventions
+	 within the packet aliasing module.
+
+    Version 3.1:  May, 2000 (eds)
+	 Add support for passive mode, alias the 227 replies.
+
+    See HISTORY file for record of revisions.
+*/
+
+/* Includes */
+#ifdef _KERNEL
+#include <freebsd/sys/param.h>
+#include <freebsd/sys/ctype.h>
+#include <freebsd/sys/systm.h>
+#include <freebsd/sys/kernel.h>
+#include <freebsd/sys/module.h>
+#else
+#include <freebsd/ctype.h>
+#include <freebsd/errno.h>
+#include <freebsd/sys/types.h>
+#include <freebsd/stdio.h>
+#include <freebsd/string.h>
+#endif
+
+#include <freebsd/netinet/in_systm.h>
+#include <freebsd/netinet/in.h>
+#include <freebsd/netinet/ip.h>
+#include <freebsd/netinet/tcp.h>
+
+#ifdef _KERNEL
+#include <freebsd/netinet/libalias/alias.h>
+#include <freebsd/netinet/libalias/alias_local.h>
+#include <freebsd/netinet/libalias/alias_mod.h>
+#else
+#include <freebsd/local/alias_local.h>
+#include <freebsd/local/alias_mod.h>
+#endif
+
+#define FTP_CONTROL_PORT_NUMBER 21
+
+static void
+AliasHandleFtpOut(struct libalias *, struct ip *, struct alias_link *,	
+		  int maxpacketsize);
+
+static int 
+fingerprint(struct libalias *la, struct alias_data *ah)
+{
+
+	if (ah->dport == NULL || ah->sport == NULL || ah->lnk == NULL || 
+		ah->maxpktsize == 0)
+		return (-1);
+	if (ntohs(*ah->dport) == FTP_CONTROL_PORT_NUMBER
+	    || ntohs(*ah->sport) == FTP_CONTROL_PORT_NUMBER)
+		return (0);
+	return (-1);
+}
+
+static int 
+protohandler(struct libalias *la, struct ip *pip, struct alias_data *ah)
+{
+	
+	AliasHandleFtpOut(la, pip, ah->lnk, ah->maxpktsize);
+	return (0);
+}
+
+struct proto_handler handlers[] = {
+	{ 
+	  .pri = 80, 
+	  .dir = OUT, 
+	  .proto = TCP, 
+	  .fingerprint = &fingerprint, 
+	  .protohandler = &protohandler
+	}, 
+	{ EOH }
+};
+
+static int
+mod_handler(module_t mod, int type, void *data)
+{
+	int error;
+
+	switch (type) {	  
+	case MOD_LOAD:
+		error = 0;
+		LibAliasAttachHandlers(handlers);
+		break;
+	case MOD_UNLOAD:
+		error = 0;
+		LibAliasDetachHandlers(handlers);
+		break;
+	default:
+		error = EINVAL;
+	}
+	return (error);
+}
+
+#ifdef _KERNEL
+static
+#endif
+moduledata_t alias_mod = {
+       "alias_ftp", mod_handler, NULL
+};
+
+#ifdef	_KERNEL
+DECLARE_MODULE(alias_ftp, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
+MODULE_VERSION(alias_ftp, 1);
+MODULE_DEPEND(alias_ftp, libalias, 1, 1, 1);
+#endif
+
+#define FTP_CONTROL_PORT_NUMBER 21
+#define MAX_MESSAGE_SIZE	128
+
+/* FTP protocol flags. */
+#define WAIT_CRLF		0x01
+
+enum ftp_message_type {
+	FTP_PORT_COMMAND,
+	FTP_EPRT_COMMAND,
+	FTP_227_REPLY,
+	FTP_229_REPLY,
+	FTP_UNKNOWN_MESSAGE
+};
+
+static int	ParseFtpPortCommand(struct libalias *la, char *, int);
+static int	ParseFtpEprtCommand(struct libalias *la, char *, int);
+static int	ParseFtp227Reply(struct libalias *la, char *, int);
+static int	ParseFtp229Reply(struct libalias *la, char *, int);
+static void	NewFtpMessage(struct libalias *la, struct ip *, struct alias_link *, int, int);
+
+static void
+AliasHandleFtpOut(
+    struct libalias *la,
+    struct ip *pip,		/* IP packet to examine/patch */
+    struct alias_link *lnk,	/* The link to go through (aliased port) */
+    int maxpacketsize		/* The maximum size this packet can grow to
+	(including headers) */ )
+{
+	int hlen, tlen, dlen, pflags;
+	char *sptr;
+	struct tcphdr *tc;
+	int ftp_message_type;
+
+/* Calculate data length of TCP packet */
+	tc = (struct tcphdr *)ip_next(pip);
+	hlen = (pip->ip_hl + tc->th_off) << 2;
+	tlen = ntohs(pip->ip_len);
+	dlen = tlen - hlen;
+
+/* Place string pointer and beginning of data */
+	sptr = (char *)pip;
+	sptr += hlen;
+
+/*
+ * Check that data length is not too long and previous message was
+ * properly terminated with CRLF.
+ */
+	pflags = GetProtocolFlags(lnk);
+	if (dlen <= MAX_MESSAGE_SIZE && !(pflags & WAIT_CRLF)) {
+		ftp_message_type = FTP_UNKNOWN_MESSAGE;
+
+		if (ntohs(tc->th_dport) == FTP_CONTROL_PORT_NUMBER) {
+/*
+ * When aliasing a client, check for the PORT/EPRT command.
+ */
+			if (ParseFtpPortCommand(la, sptr, dlen))
+				ftp_message_type = FTP_PORT_COMMAND;
+			else if (ParseFtpEprtCommand(la, sptr, dlen))
+				ftp_message_type = FTP_EPRT_COMMAND;
+		} else {
+/*
+ * When aliasing a server, check for the 227/229 reply.
+ */
+			if (ParseFtp227Reply(la, sptr, dlen))
+				ftp_message_type = FTP_227_REPLY;
+			else if (ParseFtp229Reply(la, sptr, dlen)) {
+				ftp_message_type = FTP_229_REPLY;
+				la->true_addr.s_addr = pip->ip_src.s_addr;
+			}
+		}
+
+		if (ftp_message_type != FTP_UNKNOWN_MESSAGE)
+			NewFtpMessage(la, pip, lnk, maxpacketsize, ftp_message_type);
+	}
+/* Track the msgs which are CRLF term'd for PORT/PASV FW breach */
+
+	if (dlen) {		/* only if there's data */
+		sptr = (char *)pip;	/* start over at beginning */
+		tlen = ntohs(pip->ip_len);	/* recalc tlen, pkt may
+						 * have grown */
+		if (sptr[tlen - 2] == '\r' && sptr[tlen - 1] == '\n')
+			pflags &= ~WAIT_CRLF;
+		else
+			pflags |= WAIT_CRLF;
+		SetProtocolFlags(lnk, pflags);
+	}
+}
+
+static int
+ParseFtpPortCommand(struct libalias *la, char *sptr, int dlen)
+{
+	char ch;
+	int i, state;
+	u_int32_t addr;
+	u_short port;
+	u_int8_t octet;
+
+	/* Format: "PORT A,D,D,R,PO,RT". */
+
+	/* Return if data length is too short. */
+	if (dlen < 18)
+		return (0);
+
+	if (strncasecmp("PORT ", sptr, 5))
+		return (0);
+
+	addr = port = octet = 0;
+	state = 0;
+	for (i = 5; i < dlen; i++) {
+		ch = sptr[i];
+		switch (state) {
+		case 0:
+			if (isspace(ch))
+				break;
+			else
+				state++;
+		case 1:
+		case 3:
+		case 5:
+		case 7:
+		case 9:
+		case 11:
+			if (isdigit(ch)) {
+				octet = ch - '0';
+				state++;
+			} else
+				return (0);
+			break;
+		case 2:
+		case 4:
+		case 6:
+		case 8:
+			if (isdigit(ch))
+				octet = 10 * octet + ch - '0';
+			else if (ch == ',') {
+				addr = (addr << 8) + octet;
+				state++;
+			} else
+				return (0);
+			break;
+		case 10:
+		case 12:
+			if (isdigit(ch))
+				octet = 10 * octet + ch - '0';
+			else if (ch == ',' || state == 12) {
+				port = (port << 8) + octet;
+				state++;
+			} else
+				return (0);
+			break;
+		}
+	}
+
+	if (state == 13) {
+		la->true_addr.s_addr = htonl(addr);
+		la->true_port = port;
+		return (1);
+	} else
+		return (0);
+}
+
+static int
+ParseFtpEprtCommand(struct libalias *la, char *sptr, int dlen)
+{
+	char ch, delim;
+	int i, state;
+	u_int32_t addr;
+	u_short port;
+	u_int8_t octet;
+
+	/* Format: "EPRT |1|A.D.D.R|PORT|". */
+
+	/* Return if data length is too short. */
+	if (dlen < 18)
+		return (0);
+
+	if (strncasecmp("EPRT ", sptr, 5))
+		return (0);
+
+	addr = port = octet = 0;
+	delim = '|';		/* XXX gcc -Wuninitialized */
+	state = 0;
+	for (i = 5; i < dlen; i++) {
+		ch = sptr[i];
+		switch (state) {
+		case 0:
+			if (!isspace(ch)) {
+				delim = ch;
+				state++;
+			}
+			break;
+		case 1:
+			if (ch == '1')	/* IPv4 address */
+				state++;
+			else
+				return (0);
+			break;
+		case 2:
+			if (ch == delim)
+				state++;
+			else
+				return (0);
+			break;
+		case 3:
+		case 5:
+		case 7:
+		case 9:
+			if (isdigit(ch)) {
+				octet = ch - '0';
+				state++;
+			} else
+				return (0);
+			break;
+		case 4:
+		case 6:
+		case 8:
+		case 10:
+			if (isdigit(ch))
+				octet = 10 * octet + ch - '0';
+			else if (ch == '.' || state == 10) {
+				addr = (addr << 8) + octet;
+				state++;
+			} else
+				return (0);
+			break;
+		case 11:
+			if (isdigit(ch)) {
+				port = ch - '0';
+				state++;
+			} else
+				return (0);
+			break;
+		case 12:
+			if (isdigit(ch))
+				port = 10 * port + ch - '0';
+			else if (ch == delim)
+				state++;
+			else
+				return (0);
+			break;
+		}
+	}
+
+	if (state == 13) {
+		la->true_addr.s_addr = htonl(addr);
+		la->true_port = port;
+		return (1);
+	} else
+		return (0);
+}
+
+static int
+ParseFtp227Reply(struct libalias *la, char *sptr, int dlen)
+{
+	char ch;
+	int i, state;
+	u_int32_t addr;
+	u_short port;
+	u_int8_t octet;
+
+	/* Format: "227 Entering Passive Mode (A,D,D,R,PO,RT)" */
+
+	/* Return if data length is too short. */
+	if (dlen < 17)
+		return (0);
+
+	if (strncmp("227 ", sptr, 4))
+		return (0);
+
+	addr = port = octet = 0;
+
+	state = 0;
+	for (i = 4; i < dlen; i++) {
+		ch = sptr[i];
+		switch (state) {
+		case 0:
+			if (ch == '(')
+				state++;
+			break;
+		case 1:
+		case 3:
+		case 5:
+		case 7:
+		case 9:
+		case 11:
+			if (isdigit(ch)) {
+				octet = ch - '0';
+				state++;
+			} else
+				return (0);
+			break;
+		case 2:
+		case 4:
+		case 6:
+		case 8:
+			if (isdigit(ch))
+				octet = 10 * octet + ch - '0';
+			else if (ch == ',') {
+				addr = (addr << 8) + octet;
+				state++;
+			} else
+				return (0);
+			break;
+		case 10:
+		case 12:
+			if (isdigit(ch))
+				octet = 10 * octet + ch - '0';
+			else if (ch == ',' || (state == 12 && ch == ')')) {
+				port = (port << 8) + octet;
+				state++;
+			} else
+				return (0);
+			break;
+		}
+	}
+
+	if (state == 13) {
+		la->true_port = port;
+		la->true_addr.s_addr = htonl(addr);
+		return (1);
+	} else
+		return (0);
+}
+
+static int
+ParseFtp229Reply(struct libalias *la, char *sptr, int dlen)
+{
+	char ch, delim;
+	int i, state;
+	u_short port;
+
+	/* Format: "229 Entering Extended Passive Mode (|||PORT|)" */
+
+	/* Return if data length is too short. */
+	if (dlen < 11)
+		return (0);
+
+	if (strncmp("229 ", sptr, 4))
+		return (0);
+
+	port = 0;
+	delim = '|';		/* XXX gcc -Wuninitialized */
+
+	state = 0;
+	for (i = 4; i < dlen; i++) {
+		ch = sptr[i];
+		switch (state) {
+		case 0:
+			if (ch == '(')
+				state++;
+			break;
+		case 1:
+			delim = ch;
+			state++;
+			break;
+		case 2:
+		case 3:
+			if (ch == delim)
+				state++;
+			else
+				return (0);
+			break;
+		case 4:
+			if (isdigit(ch)) {
+				port = ch - '0';
+				state++;
+			} else
+				return (0);
+			break;
+		case 5:
+			if (isdigit(ch))
+				port = 10 * port + ch - '0';
+			else if (ch == delim)
+				state++;
+			else
+				return (0);
+			break;
+		case 6:
+			if (ch == ')')
+				state++;
+			else
+				return (0);
+			break;
+		}
+	}
+
+	if (state == 7) {
+		la->true_port = port;
+		return (1);
+	} else
+		return (0);
+}
+
+static void
+NewFtpMessage(struct libalias *la, struct ip *pip,
+    struct alias_link *lnk,
+    int maxpacketsize,
+    int ftp_message_type)
+{
+	struct alias_link *ftp_lnk;
+
+/* Security checks. */
+	if (pip->ip_src.s_addr != la->true_addr.s_addr)
+		return;
+
+	if (la->true_port < IPPORT_RESERVED)
+		return;
+
+/* Establish link to address and port found in FTP control message. */
+	ftp_lnk = FindUdpTcpOut(la, la->true_addr, GetDestAddress(lnk),
+	    htons(la->true_port), 0, IPPROTO_TCP, 1);
+
+	if (ftp_lnk != NULL) {
+		int slen, hlen, tlen, dlen;
+		struct tcphdr *tc;
+
+#ifndef NO_FW_PUNCH
+		/* Punch hole in firewall */
+		PunchFWHole(ftp_lnk);
+#endif
+
+/* Calculate data length of TCP packet */
+		tc = (struct tcphdr *)ip_next(pip);
+		hlen = (pip->ip_hl + tc->th_off) << 2;
+		tlen = ntohs(pip->ip_len);
+		dlen = tlen - hlen;
+
+/* Create new FTP message. */
+		{
+			char stemp[MAX_MESSAGE_SIZE + 1];
+			char *sptr;
+			u_short alias_port;
+			u_char *ptr;
+			int a1, a2, a3, a4, p1, p2;
+			struct in_addr alias_address;
+
+/* Decompose alias address into quad format */
+			alias_address = GetAliasAddress(lnk);
+			ptr = (u_char *) & alias_address.s_addr;
+			a1 = *ptr++;
+			a2 = *ptr++;
+			a3 = *ptr++;
+			a4 = *ptr;
+
+			alias_port = GetAliasPort(ftp_lnk);
+
+/* Prepare new command */
+			switch (ftp_message_type) {
+			case FTP_PORT_COMMAND:
+			case FTP_227_REPLY:
+				/* Decompose alias port into pair format. */
+				ptr = (char *)&alias_port;
+				p1 = *ptr++;
+				p2 = *ptr;
+
+				if (ftp_message_type == FTP_PORT_COMMAND) {
+					/* Generate PORT command string. */
+					sprintf(stemp, "PORT %d,%d,%d,%d,%d,%d\r\n",
+					    a1, a2, a3, a4, p1, p2);
+				} else {
+					/* Generate 227 reply string. */
+					sprintf(stemp,
+					    "227 Entering Passive Mode (%d,%d,%d,%d,%d,%d)\r\n",
+					    a1, a2, a3, a4, p1, p2);
+				}
+				break;
+			case FTP_EPRT_COMMAND:
+				/* Generate EPRT command string. */
+				sprintf(stemp, "EPRT |1|%d.%d.%d.%d|%d|\r\n",
+				    a1, a2, a3, a4, ntohs(alias_port));
+				break;
+			case FTP_229_REPLY:
+				/* Generate 229 reply string. */
+				sprintf(stemp, "229 Entering Extended Passive Mode (|||%d|)\r\n",
+				    ntohs(alias_port));
+				break;
+			}
+
+/* Save string length for IP header modification */
+			slen = strlen(stemp);
+
+/* Copy modified buffer into IP packet. */
+			sptr = (char *)pip;
+			sptr += hlen;
+			strncpy(sptr, stemp, maxpacketsize - hlen);
+		}
+
+/* Save information regarding modified seq and ack numbers */
+		{
+			int delta;
+
+			SetAckModified(lnk);
+			tc = (struct tcphdr *)ip_next(pip);				
+			delta = GetDeltaSeqOut(tc->th_seq, lnk);
+			AddSeq(lnk, delta + slen - dlen, pip->ip_hl, 
+			    pip->ip_len, tc->th_seq, tc->th_off);
+		}
+
+/* Revise IP header */
+		{
+			u_short new_len;
+
+			new_len = htons(hlen + slen);
+			DifferentialChecksum(&pip->ip_sum,
+			    &new_len,
+			    &pip->ip_len,
+			    1);
+			pip->ip_len = new_len;
+		}
+
+/* Compute TCP checksum for revised packet */
+		tc->th_sum = 0;
+#ifdef _KERNEL
+		tc->th_x2 = 1;
+#else
+		tc->th_sum = TcpChecksum(pip);
+#endif
+	} else {
+#ifdef LIBALIAS_DEBUG
+		fprintf(stderr,
+		    "PacketAlias/HandleFtpOut: Cannot allocate FTP data port\n");
+#endif
+	}
+}