Import ax25-apps 0.0.1 from tarballax25-apps-0.0.1

1 files changed, 338 insertions, 0 deletions

diff --git a/ax25ipd/process.c b/ax25ipd/process.c
new file mode 100644
index 0000000..20bae7f
--- /dev/null
+++ b/ax25ipd/process.c
@@ -0,0 +1,338 @@
+/* process.c     Handle processing and routing of AX25 frames
+ *
+ * Copyright 1991, Michael Westerhof, Sun Microsystems, Inc.
+ * This software may be freely used, distributed, or modified, providing
+ * this header is not removed.
+ *
+ * This is the only module that knows about the internal structure of
+ * AX25 frames.
+ */
+
+/*
+ * Dual port additions by M.Durrant and D.J.Dionne Feb 4, 1995
+ */
+
+#include "ax25ipd.h"
+#include <stdio.h>
+/* if dual port the upper nibble will have a value of 1 (not 0) */
+#define FROM_PORT2(p)   (((*(p+1))&0x10)!=0)
+#define FOR_PORT2(p)    (addrmatch(p,mycallsign2) || addrmatch(p,myalias2))
+/* ve3djf and ve3pnx addition above                             */
+#define IS_LAST(p)      (((*(p+6))&0x01)!=0)
+#define NOT_LAST(p)     (((*(p+6))&0x01)==0)
+#define REPEATED(p)     (((*(p+6))&0x80)!=0)
+#define NOTREPEATED(p)  (((*(p+6))&0x80)==0)
+#define IS_ME(p)        (addrmatch(p,mycallsign) || addrmatch(p,myalias) || addrmatch(p,mycallsign2) || addrmatch(p,myalias2) )
+#define NOT_ME(p)       (!(addrmatch(p,mycallsign) || addrmatch(p,myalias) || addrmatch(p,mycallsign2) || addrmatch(p,myalias2) ) )
+#define ARE_DIGIS(f)    (((*(f+13))&0x01)==0)
+#define NO_DIGIS(f)     (((*(f+13))&0x01)!=0)
+#define SETREPEATED(p)  (*(p+6))|=0x80
+#define SETLAST(p)      (*(p+6))|=0x01
+
+unsigned char bcbuf[256];       /* Must be larger than bc_text!!! */
+int bclen;                      /* The size of bcbuf */
+
+/*
+ * Initialize the process variables
+ */
+
+void
+process_init()
+{
+	bclen = -1;             /* flag that we need to rebuild the bctext */
+}
+
+/*
+ * handle a frame given us by the kiss routines.  The buf variable is
+ * a pointer to an AX25 frame.  Note that the AX25 frame from kiss does
+ * not include the CRC bytes.  These are computed by this routine, and
+ * it is expected that the buffer we have has room for the CRC bytes.
+ * We will either dump this frame, or send it via the IP interface.
+ * 
+ * If we are in digi mode, we validate in several ways:
+ *   a) we must be the next digi in line to pick up the packet
+ *   b) the next site to get the packet (the next listed digi, or
+ *      the destination if we are the last digi) must be known to
+ *      us via the route table.
+ * If we pass validation, we then set the digipeated bit for our entry
+ * in the packet, compute the CRC, and send the packet to the IP
+ * interface.
+ *
+ * If we are in tnc mode, we have less work to do.
+ *   a) the next site to get the packet (the next listed digi, or
+ *      the destination) must be known to us via the route table.
+ * If we pass validation, we compute the CRC, and send the packet to
+ * the IP interface.
+ */
+
+void
+from_kiss(buf, l)
+unsigned char *buf;
+int l;
+{
+	unsigned char *a, *ipaddr;
+
+	if (l<15) {
+		LOGL2("from_kiss: dumped - length wrong!\n");
+		stats.kiss_tooshort++;
+		return;
+	}
+
+	if (loglevel>2)
+		dump_ax25frame("from_kiss: ", buf, l);
+
+	if(digi) {			/* if we are in digi mode */
+		a = next_addr(buf);
+		if(NOT_ME(a)){
+			stats.kiss_not_for_me++;
+			LOGL4("from_kiss: (digi) dumped - not for me\n");
+			return;
+		}
+		if (a==buf) {		/* must be a digi */
+			stats.kiss_i_am_dest++;
+			LOGL2("from_kiss: (digi) dumped - I am destination!\n");
+			return;
+		}
+		SETREPEATED(a);
+		a = next_addr(buf);	/* find who gets it after us */
+	} else {			/* must be tnc mode */
+		a = next_addr(buf);
+#ifdef TNC_FILTER
+		if (IS_ME(a)) {
+			LOGL2("from_kiss: (tnc) dumped - addressed to self!\n");
+			return;
+		}
+#endif
+	}                       /* end of tnc mode */
+
+	/* Lookup the IP address for this route */
+	ipaddr = call_to_ip(a);
+
+	if (ipaddr==NULL) {
+		if (is_call_bcast(a)) {
+			/* Warning - assuming buffer has room for 2 bytes */
+			add_crc(buf, l); l+=2;
+			send_broadcast(buf, l);
+		} else {
+			stats.kiss_no_ip_addr++;
+			LOGL2("from_kiss: dumped - cannot figure out where to send this!\n");
+		}
+		return;
+	} else {
+		/* Warning - assuming buffer has room for 2 bytes */
+		add_crc(buf, l); l+=2;
+		send_ip(buf, l, ipaddr);
+	}
+}
+
+/*
+ * handle a frame given us by the IP routines.  The buf variable is
+ * a pointer to an AX25 frame.
+ * Note that the frame includes the CRC bytes, which we dump ASAP.
+ * We will either dump this frame, or send it via the KISS interface.
+ * 
+ * If we are in digi mode, we only validate that:
+ *   a) we must be the next digi in line to pick up the packet
+ * If we pass validation, we then set the digipeated bit for our entry
+ * in the packet, and send the packet to the KISS send routine.
+ *
+ * If we are in tnc mode, we validate pretty well nothing, just like a
+ * real TNC...  #define FILTER_TNC will change this.
+ * We simply send the packet to the KISS send routine.
+ */
+
+void
+from_ip(buf, l)
+unsigned char *buf;
+int l;
+{
+	int port = 0;
+	unsigned char *a;
+
+	if(!ok_crc(buf, l)){
+		stats.ip_failed_crc++;
+		LOGL2("from_ip: dumped - CRC incorrect!\n");
+		return;
+	}
+	l = l - 2;      /* dump the blasted CRC */
+
+	if(l<15){
+		stats.ip_tooshort++;
+		LOGL2("from_ip: dumped - length wrong!\n");
+		return;
+	}
+
+	if(loglevel>2)dump_ax25frame("from_ip: ", buf, l);
+
+	if(digi){               /* if we are in digi mode */
+		a = next_addr(buf);
+		if(NOT_ME(a)){
+			stats.ip_not_for_me++;
+			LOGL2("from_ip: (digi) dumped - not for me!\n");
+			return;
+		}
+		if(a==buf){     /* must be a digi */
+			stats.ip_i_am_dest++;
+			LOGL2("from_ip: (digi) dumped - I am destination!\n");
+			return;
+		}
+		if(dual_port == 1 && FOR_PORT2(a)){
+			port = 0x10;
+		}
+		SETREPEATED(a);
+	} else {                /* must be tnc mode */
+		a = next_addr(buf);
+#ifdef TNC_FILTER
+		if(NOT_ME(a)){
+			LOGL2("from_ip: (tnc) dumped - I am not destination!\n");
+			return;
+		}
+#endif
+	}                       /* end of tnc mode */
+	send_kiss(port, buf, l);
+}
+
+/*
+ * Send an ID frame out the KISS port.
+ */
+
+void
+do_beacon()
+{
+	int i;
+	unsigned char *p;
+
+	if(bclen == 0) return;          /* nothing to do! */
+
+	if(bclen < 0) {                 /* build the id string */
+		p = bcbuf;
+		*p++ = ('I'<<1);
+		*p++ = ('D'<<1);
+		*p++ = (' '<<1);
+		*p++ = (' '<<1);
+		*p++ = (' '<<1);
+		*p++ = (' '<<1);
+		*p++ = '\0' | 0x60;             /* SSID, set reserved bits */
+
+		for(i=0;i<6;i++)*p++=mycallsign[i];
+		*p++ = mycallsign[6] | 0x60;    /* ensure reserved bits are set */
+		SETLAST(bcbuf+7);               /* Set the E bit -- last address */
+
+		*p++ = 0x03;                    /* Control field -- UI frame */
+
+		*p++ = 0xf0;                    /* Protocol ID -- 0xf0 is no protocol */
+
+		strcpy(p, bc_text);       /* add the text field */
+
+		bclen = 16 + strlen(bc_text);   /* adjust the length nicely */
+	}
+
+	if(loglevel>2)dump_ax25frame("do_beacon: ", bcbuf, bclen);
+	stats.kiss_beacon_outs++;
+	send_kiss(0, bcbuf, bclen);
+}
+
+/*
+ * return true if the addresses supplied match
+ * modified for wildcarding by vk5xxx
+ */
+int
+addrmatch(a,b)
+unsigned char *a, *b;
+{
+	if((*a=='\0') || (*b=='\0'))return 0;
+
+	if((*a++^*b++)&0xfe)return 0;   /* "K" */
+	if((*a++^*b++)&0xfe)return 0;   /* "A" */
+	if((*a++^*b++)&0xfe)return 0;   /* "9" */
+	if((*a++^*b++)&0xfe)return 0;   /* "W" */
+	if((*a++^*b++)&0xfe)return 0;   /* "S" */
+	if((*a++^*b++)&0xfe)return 0;   /* "B" */
+	if(((*b++)&0x1e)==0)return 1;	/* ssid 0 matches all ssid's */
+	if((*a++^*b)&0x1e)return 0;  	/* ssid */
+/*	if((*a++^*b++)&0x1e)return 0;      ssid (how it was ...) */
+	return 1;
+}
+
+/*
+ * return pointer to the next station to get this packet
+ */
+unsigned char *
+next_addr(f)
+unsigned char *f;
+{
+	unsigned char *a;
+
+/* If no digis, return the destination address */
+	if(NO_DIGIS(f))return f;
+
+/* check each digi field.  The first one that hasn't seen it is the one */
+	a = f + 7;
+	do {
+		a += 7;
+		if(NOTREPEATED(a))return a;
+	}while(NOT_LAST(a));
+
+/* all the digis have seen it.  return the destination address */
+	return f;       
+}
+
+/*
+ * tack on the CRC for the frame.  Note we assume the buffer is long
+ * enough to have the two bytes tacked on.
+ */
+void
+add_crc(buf, l)
+unsigned char *buf;
+int l;
+{
+	unsigned short int u;
+
+	u = compute_crc(buf, l);
+	buf[l] = u&0xff;                /* lsb first */
+	buf[l+1] = (u>>8)&0xff;         /* msb next */
+}
+
+/*
+ * Dump AX25 frame.
+ */
+void
+dump_ax25frame(t, buf, l)
+unsigned char *buf;
+char *t;
+int l;
+{
+#ifdef DEBUG
+	int i;
+#endif
+	unsigned char *a;
+
+	printf("%s AX25: (l=%3d)   ", t, l);
+
+	if(l<15){
+		printf("Bogus size...\n");
+		return;
+	}
+
+	printf("%s -> ", call_to_a(buf+7));
+	printf("%s", call_to_a(buf));
+
+	if(ARE_DIGIS(buf)){
+		printf(" v");
+		a = buf+7;
+		do{
+			a+=7;
+			printf(" %s", call_to_a(a));
+			if(REPEATED(a))printf("*");
+		}while(NOT_LAST(a));
+	}
+
+	printf("\n");
+
+#ifdef DEBUG
+	for(i=0;i<l;i++)printf("%02x ",buf[i]);
+	printf("\n");
+#endif
+
+	fflush(stdout);
+}