Initial import

Code is based on FreeBSD 8.2 with USB support from Sebastian Huber
and Thomas Doerfler. Initial TCP/IP stack work is from Kevel Kirspel.

1 files changed, 490 insertions, 0 deletions

diff --git a/rtems/freebsd/netinet/libalias/alias_irc.c b/rtems/freebsd/netinet/libalias/alias_irc.c
new file mode 100644
index 00000000..fd2f0763
--- /dev/null
+++ b/rtems/freebsd/netinet/libalias/alias_irc.c
@@ -0,0 +1,490 @@
+#include <rtems/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 <rtems/freebsd/sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/* Alias_irc.c intercepts packages contain IRC CTCP commands, and
+	changes DCC commands to export a port on the aliasing host instead
+	of an aliased host.
+
+    For this routine to work, the DCC command must fit entirely into a
+    single TCP packet.  This will usually happen, but is not
+    guaranteed.
+
+	 The interception is likely to change the length of the packet.
+	 The handling of this is copied more-or-less verbatim from
+	 ftp_alias.c
+
+	 Initial version: Eivind Eklund <perhaps@yes.no> (ee) 97-01-29
+
+	 Version 2.1:  May, 1997 (cjm)
+	     Very minor changes to conform with
+	     local/global/function naming conventions
+	     withing the packet alising module.
+*/
+
+/* Includes */
+#ifdef _KERNEL
+#include <rtems/freebsd/sys/param.h>
+#include <rtems/freebsd/sys/ctype.h>
+#include <rtems/freebsd/sys/limits.h>
+#include <rtems/freebsd/sys/systm.h>
+#include <rtems/freebsd/sys/kernel.h>
+#include <rtems/freebsd/sys/module.h>
+#else
+#include <rtems/freebsd/ctype.h>
+#include <rtems/freebsd/errno.h>
+#include <rtems/freebsd/sys/types.h>
+#include <rtems/freebsd/stdio.h>
+#include <rtems/freebsd/stdlib.h>
+#include <rtems/freebsd/string.h>
+#include <rtems/freebsd/limits.h>
+#endif
+
+#include <rtems/freebsd/netinet/in_systm.h>
+#include <rtems/freebsd/netinet/in.h>
+#include <rtems/freebsd/netinet/ip.h>
+#include <rtems/freebsd/netinet/tcp.h>
+
+#ifdef _KERNEL
+#include <rtems/freebsd/netinet/libalias/alias.h>
+#include <rtems/freebsd/netinet/libalias/alias_local.h>
+#include <rtems/freebsd/netinet/libalias/alias_mod.h>
+#else
+#include <rtems/freebsd/local/alias_local.h>
+#include <rtems/freebsd/local/alias_mod.h>
+#endif
+
+#define IRC_CONTROL_PORT_NUMBER_1 6667
+#define IRC_CONTROL_PORT_NUMBER_2 6668
+
+#define PKTSIZE (IP_MAXPACKET + 1)
+char *newpacket;
+
+/* Local defines */
+#define DBprintf(a)
+
+static void
+AliasHandleIrcOut(struct libalias *, struct ip *, struct alias_link *,
+		  int maxpacketsize);
+
+static int
+fingerprint(struct libalias *la, struct alias_data *ah)
+{
+
+	if (ah->dport == NULL || ah->dport == NULL || ah->lnk == NULL ||
+	    ah->maxpktsize == 0)
+		return (-1);
+	if (ntohs(*ah->dport) == IRC_CONTROL_PORT_NUMBER_1
+	    || ntohs(*ah->dport) == IRC_CONTROL_PORT_NUMBER_2)
+		return (0);
+	return (-1);
+}
+
+static int
+protohandler(struct libalias *la, struct ip *pip, struct alias_data *ah)
+{
+
+	newpacket = malloc(PKTSIZE);
+	if (newpacket) {
+		AliasHandleIrcOut(la, pip, ah->lnk, ah->maxpktsize);
+		free(newpacket);
+	}
+	return (0);
+}
+
+struct proto_handler handlers[] = {
+	{
+	  .pri = 90,
+	  .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_irc", mod_handler, NULL
+};
+
+/* Kernel module definition. */
+#ifdef	_KERNEL
+DECLARE_MODULE(alias_irc, alias_mod, SI_SUB_DRIVERS, SI_ORDER_SECOND);
+MODULE_VERSION(alias_irc, 1);
+MODULE_DEPEND(alias_irc, libalias, 1, 1, 1);
+#endif
+
+static void
+AliasHandleIrcOut(struct libalias *la,
+    struct ip *pip,		/* IP packet to examine */
+    struct alias_link *lnk,	/* Which link are we on? */
+    int maxsize			/* Maximum size of IP packet including
+				 * headers */
+)
+{
+	int hlen, tlen, dlen;
+	struct in_addr true_addr;
+	u_short true_port;
+	char *sptr;
+	struct tcphdr *tc;
+	int i;			/* Iterator through the source */
+
+/* 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;
+
+	/*
+	 * Return if data length is too short - assume an entire PRIVMSG in
+	 * each packet.
+	 */
+	if (dlen < (int)sizeof(":A!a@n.n PRIVMSG A :aDCC 1 1a") - 1)
+		return;
+
+/* Place string pointer at beginning of data */
+	sptr = (char *)pip;
+	sptr += hlen;
+	maxsize -= hlen;	/* We're interested in maximum size of
+				 * data, not packet */
+
+	/* Search for a CTCP command [Note 1] */
+	for (i = 0; i < dlen; i++) {
+		if (sptr[i] == '\001')
+			goto lFOUND_CTCP;
+	}
+	return;			/* No CTCP commands in  */
+	/* Handle CTCP commands - the buffer may have to be copied */
+lFOUND_CTCP:
+	{
+		unsigned int copyat = i;
+		unsigned int iCopy = 0;	/* How much data have we written to
+					 * copy-back string? */
+		unsigned long org_addr;	/* Original IP address */
+		unsigned short org_port;	/* Original source port
+						 * address */
+
+lCTCP_START:
+		if (i >= dlen || iCopy >= PKTSIZE)
+			goto lPACKET_DONE;
+		newpacket[iCopy++] = sptr[i++];	/* Copy the CTCP start
+						 * character */
+		/* Start of a CTCP */
+		if (i + 4 >= dlen)	/* Too short for DCC */
+			goto lBAD_CTCP;
+		if (sptr[i + 0] != 'D')
+			goto lBAD_CTCP;
+		if (sptr[i + 1] != 'C')
+			goto lBAD_CTCP;
+		if (sptr[i + 2] != 'C')
+			goto lBAD_CTCP;
+		if (sptr[i + 3] != ' ')
+			goto lBAD_CTCP;
+		/* We have a DCC command - handle it! */
+		i += 4;		/* Skip "DCC " */
+		if (iCopy + 4 > PKTSIZE)
+			goto lPACKET_DONE;
+		newpacket[iCopy++] = 'D';
+		newpacket[iCopy++] = 'C';
+		newpacket[iCopy++] = 'C';
+		newpacket[iCopy++] = ' ';
+
+		DBprintf(("Found DCC\n"));
+		/*
+		 * Skip any extra spaces (should not occur according to
+		 * protocol, but DCC breaks CTCP protocol anyway
+		 */
+		while (sptr[i] == ' ') {
+			if (++i >= dlen) {
+				DBprintf(("DCC packet terminated in just spaces\n"));
+				goto lPACKET_DONE;
+			}
+		}
+
+		DBprintf(("Transferring command...\n"));
+		while (sptr[i] != ' ') {
+			newpacket[iCopy++] = sptr[i];
+			if (++i >= dlen || iCopy >= PKTSIZE) {
+				DBprintf(("DCC packet terminated during command\n"));
+				goto lPACKET_DONE;
+			}
+		}
+		/* Copy _one_ space */
+		if (i + 1 < dlen && iCopy < PKTSIZE)
+			newpacket[iCopy++] = sptr[i++];
+
+		DBprintf(("Done command - removing spaces\n"));
+		/*
+		 * Skip any extra spaces (should not occur according to
+		 * protocol, but DCC breaks CTCP protocol anyway
+		 */
+		while (sptr[i] == ' ') {
+			if (++i >= dlen) {
+				DBprintf(("DCC packet terminated in just spaces (post-command)\n"));
+				goto lPACKET_DONE;
+			}
+		}
+
+		DBprintf(("Transferring filename...\n"));
+		while (sptr[i] != ' ') {
+			newpacket[iCopy++] = sptr[i];
+			if (++i >= dlen || iCopy >= PKTSIZE) {
+				DBprintf(("DCC packet terminated during filename\n"));
+				goto lPACKET_DONE;
+			}
+		}
+		/* Copy _one_ space */
+		if (i + 1 < dlen && iCopy < PKTSIZE)
+			newpacket[iCopy++] = sptr[i++];
+
+		DBprintf(("Done filename - removing spaces\n"));
+		/*
+		 * Skip any extra spaces (should not occur according to
+		 * protocol, but DCC breaks CTCP protocol anyway
+		 */
+		while (sptr[i] == ' ') {
+			if (++i >= dlen) {
+				DBprintf(("DCC packet terminated in just spaces (post-filename)\n"));
+				goto lPACKET_DONE;
+			}
+		}
+
+		DBprintf(("Fetching IP address\n"));
+		/* Fetch IP address */
+		org_addr = 0;
+		while (i < dlen && isdigit(sptr[i])) {
+			if (org_addr > ULONG_MAX / 10UL) {	/* Terminate on overflow */
+				DBprintf(("DCC Address overflow (org_addr == 0x%08lx, next char %c\n", org_addr, sptr[i]));
+				goto lBAD_CTCP;
+			}
+			org_addr *= 10;
+			org_addr += sptr[i++] - '0';
+		}
+		DBprintf(("Skipping space\n"));
+		if (i + 1 >= dlen || sptr[i] != ' ') {
+			DBprintf(("Overflow (%d >= %d) or bad character (%02x) terminating IP address\n", i + 1, dlen, sptr[i]));
+			goto lBAD_CTCP;
+		}
+		/*
+		 * Skip any extra spaces (should not occur according to
+		 * protocol, but DCC breaks CTCP protocol anyway, so we
+		 * might as well play it safe
+		 */
+		while (sptr[i] == ' ') {
+			if (++i >= dlen) {
+				DBprintf(("Packet failure - space overflow.\n"));
+				goto lPACKET_DONE;
+			}
+		}
+		DBprintf(("Fetching port number\n"));
+		/* Fetch source port */
+		org_port = 0;
+		while (i < dlen && isdigit(sptr[i])) {
+			if (org_port > 6554) {	/* Terminate on overflow
+						 * (65536/10 rounded up */
+				DBprintf(("DCC: port number overflow\n"));
+				goto lBAD_CTCP;
+			}
+			org_port *= 10;
+			org_port += sptr[i++] - '0';
+		}
+		/* Skip illegal addresses (or early termination) */
+		if (i >= dlen || (sptr[i] != '\001' && sptr[i] != ' ')) {
+			DBprintf(("Bad port termination\n"));
+			goto lBAD_CTCP;
+		}
+		DBprintf(("Got IP %lu and port %u\n", org_addr, (unsigned)org_port));
+
+		/* We've got the address and port - now alias it */
+		{
+			struct alias_link *dcc_lnk;
+			struct in_addr destaddr;
+
+
+			true_port = htons(org_port);
+			true_addr.s_addr = htonl(org_addr);
+			destaddr.s_addr = 0;
+
+			/* Sanity/Security checking */
+			if (!org_addr || !org_port ||
+			    pip->ip_src.s_addr != true_addr.s_addr ||
+			    org_port < IPPORT_RESERVED)
+				goto lBAD_CTCP;
+
+			/*
+			 * Steal the FTP_DATA_PORT - it doesn't really
+			 * matter, and this would probably allow it through
+			 * at least _some_ firewalls.
+			 */
+			dcc_lnk = FindUdpTcpOut(la, true_addr, destaddr,
+			    true_port, 0,
+			    IPPROTO_TCP, 1);
+			DBprintf(("Got a DCC link\n"));
+			if (dcc_lnk) {
+				struct in_addr alias_address;	/* Address from aliasing */
+				u_short alias_port;	/* Port given by
+							 * aliasing */
+				int n;
+
+#ifndef NO_FW_PUNCH
+				/* Generate firewall hole as appropriate */
+				PunchFWHole(dcc_lnk);
+#endif
+
+				alias_address = GetAliasAddress(lnk);
+				n = snprintf(&newpacket[iCopy],
+				    PKTSIZE - iCopy,
+				    "%lu ", (u_long) htonl(alias_address.s_addr));
+				if (n < 0) {
+					DBprintf(("DCC packet construct failure.\n"));
+					goto lBAD_CTCP;
+				}
+				if ((iCopy += n) >= PKTSIZE) {	/* Truncated/fit exactly
+										 * - bad news */
+					DBprintf(("DCC constructed packet overflow.\n"));
+					goto lBAD_CTCP;
+				}
+				alias_port = GetAliasPort(dcc_lnk);
+				n = snprintf(&newpacket[iCopy],
+				    PKTSIZE - iCopy,
+				    "%u", htons(alias_port));
+				if (n < 0) {
+					DBprintf(("DCC packet construct failure.\n"));
+					goto lBAD_CTCP;
+				}
+				iCopy += n;
+				/*
+				 * Done - truncated cases will be taken
+				 * care of by lBAD_CTCP
+				 */
+				DBprintf(("Aliased IP %lu and port %u\n", alias_address.s_addr, (unsigned)alias_port));
+			}
+		}
+		/*
+		 * An uninteresting CTCP - state entered right after '\001'
+		 * has been pushed.  Also used to copy the rest of a DCC,
+		 * after IP address and port has been handled
+		 */
+lBAD_CTCP:
+		for (; i < dlen && iCopy < PKTSIZE; i++, iCopy++) {
+			newpacket[iCopy] = sptr[i];	/* Copy CTCP unchanged */
+			if (sptr[i] == '\001') {
+				goto lNORMAL_TEXT;
+			}
+		}
+		goto lPACKET_DONE;
+		/* Normal text */
+lNORMAL_TEXT:
+		for (; i < dlen && iCopy < PKTSIZE; i++, iCopy++) {
+			newpacket[iCopy] = sptr[i];	/* Copy CTCP unchanged */
+			if (sptr[i] == '\001') {
+				goto lCTCP_START;
+			}
+		}
+		/* Handle the end of a packet */
+lPACKET_DONE:
+		iCopy = iCopy > maxsize - copyat ? maxsize - copyat : iCopy;
+		memcpy(sptr + copyat, newpacket, iCopy);
+
+/* 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 + copyat + iCopy - dlen, pip->ip_hl,
+			    pip->ip_len, tc->th_seq, tc->th_off);
+		}
+
+		/* Revise IP header */
+		{
+			u_short new_len;
+
+			new_len = htons(hlen + iCopy + copyat);
+			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
+		return;
+	}
+}
+
+/* Notes:
+	[Note 1]
+	The initial search will most often fail; it could be replaced with a 32-bit specific search.
+	Such a search would be done for 32-bit unsigned value V:
+	V ^= 0x01010101;				  (Search is for null bytes)
+	if( ((V-0x01010101)^V) & 0x80808080 ) {
+     (found a null bytes which was a 01 byte)
+	}
+   To assert that the processor is 32-bits, do
+   extern int ircdccar[32];        (32 bits)
+   extern int ircdccar[CHAR_BIT*sizeof(unsigned int)];
+   which will generate a type-error on all but 32-bit machines.
+
+	[Note 2] This routine really ought to be replaced with one that
+	creates a transparent proxy on the aliasing host, to allow arbitary
+	changes in the TCP stream.  This should not be too difficult given
+	this base;  I (ee) will try to do this some time later.
+	*/