Import ax25-tools 0.0.1 from tarballax25-tools-0.0.1

1 files changed, 376 insertions, 0 deletions

diff --git a/ax25/rxecho.c b/ax25/rxecho.c
new file mode 100644
index 0000000..31334aa
--- /dev/null
+++ b/ax25/rxecho.c
@@ -0,0 +1,376 @@
+/*
+ * rxecho.c - Copies AX.25 packets from an interface to another interface.
+ *            Reads CONFIGFILE (see below) and uses that information to
+ *            decide what packets should be copied and where.
+ *
+ *            CONFIGFILE format is:
+ *
+ *              # this is a comment
+ *              144	kiss0	oh2bns-1,oh2bns-2
+ *              kiss0	144	*
+ *
+ *            This means that packets received on port 144 are copied to port
+ *            kiss0 if they are destined to oh2bns-1 or oh2bns-2. Packets
+ *            from port kiss0 are all copied to port 144.
+ *
+ *            There may be empty lines and an arbirary amount of white
+ *            space around the tokens but the callsign field must not
+ *            have any spaces in it. There can be up to MAXCALLS call-
+ *            signs in the callsign field (see below).
+ *
+ * Copyright (C) 1996 by Tomi Manninen, OH2BNS, <tomi.manninen@hut.fi>.
+ *
+ * *** Modified 9/9/96 by Heikki Hannikainen, OH7LZB, <hessu@pspt.fi>:
+ *
+ *            One port can actually be echoed to multiple ports (with a
+ *            different recipient callsign, of course). The old behaviour was
+ *            to give up on the first matching port, even if the recipient
+ *            callsign didn't match (and the frame wasn't echoed anywhere).
+ *
+ * ***
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <syslog.h>
+#include <signal.h>
+#include <sys/types.h>
+
+#include <sys/socket.h>
+#include <net/ethernet.h>
+#include <netinet/in.h>
+#include <netax25/ax25.h>
+#include <netrose/rose.h>
+
+#include <netax25/axlib.h>
+#include <netax25/axconfig.h>
+#include <netax25/daemon.h>
+
+#include <config.h>
+
+#include "../pathnames.h"
+
+#define MAXCALLS	8
+
+struct config {
+	char		from[14];	/* sockaddr.sa_data is 14 bytes	*/
+	char		to[14];
+	ax25_address	calls[MAXCALLS];/* list of calls to echo	*/
+	int		ncalls;		/* number of calls to echo	*/
+
+	struct config	*next;
+};
+
+static int logging = FALSE;
+
+static void terminate(int sig)
+{
+	if (logging) {
+		syslog(LOG_INFO, "terminating on SIGTERM\n");
+		closelog();
+	}
+	
+	exit(0);
+}
+
+/*
+ * Read string "call1,call2,call3,..." into p.
+ */
+static int read_calls(struct config *p, char *s)
+{
+	char *cp, *cp1;
+
+	if (p == NULL || s == NULL)
+		return -1;
+
+	p->ncalls = 0;
+
+	if (strcmp(s, "*") == 0)
+		return 0;
+
+	cp = s;
+
+	while ((cp1 = strchr(cp, ',')) != NULL && p->ncalls < MAXCALLS) {
+		*cp1 = 0;
+
+		if (ax25_aton_entry(cp, p->calls[p->ncalls].ax25_call) == -1)
+			return -1;
+
+		p->ncalls++;
+		cp = ++cp1;
+	}
+
+	if (p->ncalls < MAXCALLS) {
+		if (ax25_aton_entry(cp, p->calls[p->ncalls].ax25_call) == -1)
+			return -1;
+
+		p->ncalls++;
+	}
+
+	return p->ncalls;
+}
+
+static struct config *readconfig(void)
+{
+	FILE *fp;
+	char line[80], *cp, *dev;
+	struct config *p, *list = NULL;
+
+	if ((fp = fopen(CONF_RXECHO_FILE, "r")) == NULL) {
+		fprintf(stderr, "rxecho: cannot open config file\n");
+		return NULL;
+	}
+
+	while (fgets(line, 80, fp) != NULL) {
+		cp = strtok(line, " \t\r\n");
+
+		if (cp == NULL || cp[0] == '#')
+			continue;
+
+		if ((p = calloc(1, sizeof(struct config))) == NULL) {
+			perror("rxecho: malloc");
+			return NULL;
+		}
+
+		if ((dev = ax25_config_get_dev(cp)) == NULL) {
+			fprintf(stderr, "rxecho: invalid port name - %s\n", cp);
+			return NULL;
+		}
+
+		strcpy(p->from, dev);
+
+		if ((cp = strtok(NULL, " \t\r\n")) == NULL) {
+			fprintf(stderr, "rxecho: config file error.\n");
+			return NULL;
+		}
+
+		if ((dev = ax25_config_get_dev(cp)) == NULL) {
+			fprintf(stderr, "rxecho: invalid port name - %s\n", cp);
+			return NULL;
+		}
+
+		strcpy(p->to, dev);
+
+		if (read_calls(p, strtok(NULL, " \t\r\n")) == -1) {
+			fprintf(stderr, "rxecho: config file error.\n");
+			return NULL;
+		}
+
+		p->next = list;
+		list = p;
+	}
+
+	fclose(fp);
+
+	if (list == NULL)
+		fprintf(stderr, "rxecho: Empty config file!\n");
+
+	return list;
+}
+
+/*
+ *	Slightly modified from linux/include/net/ax25.h and 
+ *	linux/net/ax25/ax25_subr.c:
+ */
+
+#if 0
+#define C_COMMAND	1
+#define C_RESPONSE	2
+#define LAPB_C		0x80
+#endif
+#define LAPB_E		0x01
+#define AX25_ADDR_LEN	7
+#define AX25_REPEATED	0x80
+
+typedef struct {
+	ax25_address calls[AX25_MAX_DIGIS];
+	unsigned char repeated[AX25_MAX_DIGIS];
+	char ndigi;
+	char lastrepeat;
+} ax25_digi;
+
+/*
+ *	Given an AX.25 address pull of to, from, digi list, and the start of data.
+ */
+static unsigned char *ax25_parse_addr(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi)
+{
+	int d = 0;
+	
+	if (len < 14) return NULL;
+		
+#if 0
+	if (flags != NULL) {
+		*flags = 0;
+	
+		if (buf[6] & LAPB_C) {
+			*flags = C_COMMAND;
+		}
+
+		if (buf[13] & LAPB_C) {
+			*flags = C_RESPONSE;
+		}
+	}
+		
+	if (dama != NULL) 
+		*dama = ~buf[13] & DAMA_FLAG;
+#endif
+		
+	/* Copy to, from */
+	if (dest != NULL) 
+		memcpy(dest, buf + 0, AX25_ADDR_LEN);
+
+	if (src != NULL)  
+		memcpy(src,  buf + 7, AX25_ADDR_LEN);
+
+	buf += 2 * AX25_ADDR_LEN;
+	len -= 2 * AX25_ADDR_LEN;
+
+	digi->lastrepeat = -1;
+	digi->ndigi      = 0;
+	
+	while (!(buf[-1] & LAPB_E)) {
+		if (d >= AX25_MAX_DIGIS)  return NULL;	/* Max of 6 digis */
+		if (len < 7) return NULL;		/* Short packet */
+
+		if (digi != NULL) {
+			memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
+			digi->ndigi = d + 1;
+
+			if (buf[6] & AX25_REPEATED) {
+				digi->repeated[d] = 1;
+				digi->lastrepeat  = d;
+			} else {
+				digi->repeated[d] = 0;
+			}
+		}
+
+		buf += AX25_ADDR_LEN;
+		len -= AX25_ADDR_LEN;
+		d++;
+	}
+
+	return buf;
+}
+
+/*
+ * Check if frame should be echoed. Return 0 if it should and -1 if not.
+ */
+static int check_calls(struct config *cfg, unsigned char *buf, int len)
+{
+	ax25_address dest;
+	ax25_digi digi;
+	ax25_address *axp;
+	int i;
+
+	if ((buf[0] & 0x0F) != 0)
+		return -1;			/* don't echo non-data	*/
+
+	if (cfg->ncalls == 0)
+		return 0;			/* copy everything	*/
+
+	if (ax25_parse_addr(++buf, --len, NULL, &dest, &digi) == NULL)
+		return -1;			/* invalid ax.25 header	*/
+
+	/*
+	 * If there are no digis or all digis are already repeated
+	 * use destination address. Else use first non-repeated digi.
+	 */
+	if (digi.ndigi == 0 || digi.ndigi == digi.lastrepeat + 1)
+		axp = &dest;
+	else
+		axp = &digi.calls[digi.lastrepeat + 1];
+
+	for (i = 0; i < cfg->ncalls; i++)
+		if (ax25_cmp(&cfg->calls[i], axp) == 0)
+			return 0;
+
+	return -1;
+}
+
+int main(int argc, char **argv)
+{
+	struct sockaddr sa;
+	int s, size, alen;
+	unsigned char buf[1500];
+	struct config *p, *list;
+
+	while ((s = getopt(argc, argv, "lv")) != -1) {
+		switch (s) {
+			case 'l':
+				logging = TRUE;
+				break;
+			case 'v':
+				printf("rxecho: %s\n", VERSION);
+				return 0;
+			default:
+				fprintf(stderr, "usage: rxecho [-l] [-v]\n");
+				return 1;
+		}
+	}
+
+	signal(SIGTERM, terminate);
+
+	if (ax25_config_load_ports() == 0) {
+		fprintf(stderr, "rxecho: no AX.25 port data configured\n");
+		return 1;
+	}
+
+	if ((list = readconfig()) == NULL)
+		return 1;
+
+	if ((s = socket(AF_INET, SOCK_PACKET, htons(ETH_P_AX25))) == -1) {
+		perror("rxecho: socket:");
+		return 1;
+	}
+
+	if (!daemon_start(FALSE)) {
+		fprintf(stderr, "rxecho: cannot become a daemon\n");
+		close(s);
+		return 1;
+	}
+
+	if (logging) {
+		openlog("rxecho", LOG_PID, LOG_DAEMON);
+		syslog(LOG_INFO, "starting");
+	}
+
+	for (;;) {
+		alen = sizeof(sa);
+
+		if ((size = recvfrom(s, buf, 1500, 0, &sa, &alen)) == -1) {
+			if (logging) {
+				syslog(LOG_ERR, "recvfrom: %m");
+				closelog();
+			}
+			return 1;
+		}
+
+		for (p = list; p != NULL; p = p->next)
+ 			if ((strcmp(p->from, sa.sa_data) == 0) && (check_calls(p, buf, size) == 0)) {
+ 				strcpy(sa.sa_data, p->to);
+				if (sendto(s, buf, size, 0, &sa, alen) == -1) {
+					if (logging) {
+						syslog(LOG_ERR, "sendto: %m");
+						closelog();
+					}
+				}
+			}
+	}
+}