1 files changed, 290 insertions, 0 deletions

diff --git a/net/ax25/ax25_addr.c b/net/ax25/ax25_addr.c
new file mode 100644
index 000000000000..f4fa6dfb846e
--- /dev/null
+++ b/net/ax25/ax25_addr.c
@@ -0,0 +1,290 @@
+/*
+ * 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.
+ *
+ * Copyright (C) Jonathan Naylor G4KLX (g4klx@g4klx.demon.co.uk)
+ */
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/in.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/timer.h>
+#include <linux/string.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <net/ax25.h>
+#include <linux/inet.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <net/sock.h>
+#include <asm/uaccess.h>
+#include <asm/system.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+
+/*
+ *      The null address is defined as a callsign of all spaces with an
+ *      SSID of zero.
+ */
+ax25_address null_ax25_address = {{0x40, 0x40, 0x40, 0x40, 0x40, 0x40, 0x00}};
+
+/*
+ *      ax25 -> ascii conversion
+ */
+char *ax2asc(ax25_address *a)
+{
+        static char buf[11];
+        char c, *s;
+        int n;
+
+        for (n = 0, s = buf; n < 6; n++) {
+                c = (a->ax25_call[n] >> 1) & 0x7F;
+
+                if (c != ' ') *s++ = c;
+        }
+
+        *s++ = '-';
+
+        if ((n = ((a->ax25_call[6] >> 1) & 0x0F)) > 9) {
+                *s++ = '1';
+                n -= 10;
+        }
+
+        *s++ = n + '0';
+        *s++ = '\0';
+
+        if (*buf == '\0' || *buf == '-')
+           return "*";
+
+        return buf;
+
+}
+
+/*
+ *      ascii -> ax25 conversion
+ */
+ax25_address *asc2ax(char *callsign)
+{
+        static ax25_address addr;
+        char *s;
+        int n;
+
+        for (s = callsign, n = 0; n < 6; n++) {
+                if (*s != '\0' && *s != '-')
+                        addr.ax25_call[n] = *s++;
+                else
+                        addr.ax25_call[n] = ' ';
+                addr.ax25_call[n] <<= 1;
+                addr.ax25_call[n] &= 0xFE;
+        }
+
+        if (*s++ == '\0') {
+                addr.ax25_call[6] = 0x00;
+                return &addr;
+        }
+
+        addr.ax25_call[6] = *s++ - '0';
+
+        if (*s != '\0') {
+                addr.ax25_call[6] *= 10;
+                addr.ax25_call[6] += *s++ - '0';
+        }
+
+        addr.ax25_call[6] <<= 1;
+        addr.ax25_call[6] &= 0x1E;
+
+        return &addr;
+}
+
+/*
+ *      Compare two ax.25 addresses
+ */
+int ax25cmp(ax25_address *a, ax25_address *b)
+{
+        int ct = 0;
+
+        while (ct < 6) {
+                if ((a->ax25_call[ct] & 0xFE) != (b->ax25_call[ct] & 0xFE))     /* Clean off repeater bits */
+                        return 1;
+                ct++;
+        }
+
+        if ((a->ax25_call[ct] & 0x1E) == (b->ax25_call[ct] & 0x1E))     /* SSID without control bit */
+                return 0;
+
+        return 2;                       /* Partial match */
+}
+
+/*
+ *      Compare two AX.25 digipeater paths.
+ */
+int ax25digicmp(ax25_digi *digi1, ax25_digi *digi2)
+{
+        int i;
+
+        if (digi1->ndigi != digi2->ndigi)
+                return 1;
+
+        if (digi1->lastrepeat != digi2->lastrepeat)
+                return 1;
+
+        for (i = 0; i < digi1->ndigi; i++)
+                if (ax25cmp(&digi1->calls[i], &digi2->calls[i]) != 0)
+                        return 1;
+
+        return 0;
+}
+
+/*
+ *      Given an AX.25 address pull of to, from, digi list, command/response and the start of data
+ *
+ */
+unsigned char *ax25_addr_parse(unsigned char *buf, int len, ax25_address *src, ax25_address *dest, ax25_digi *digi, int *flags, int *dama)
+{
+        int d = 0;
+
+        if (len < 14) return NULL;
+
+        if (flags != NULL) {
+                *flags = 0;
+
+                if (buf[6] & AX25_CBIT)
+                        *flags = AX25_COMMAND;
+                if (buf[13] & AX25_CBIT)
+                        *flags = AX25_RESPONSE;
+        }
+
+        if (dama != NULL)
+                *dama = ~buf[13] & AX25_DAMA_FLAG;
+
+        /* 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] & AX25_EBIT)) {
+                if (d >= AX25_MAX_DIGIS)  return NULL;  /* Max of 6 digis */
+                if (len < 7) return NULL;       /* Short packet */
+
+                memcpy(&digi->calls[d], buf, AX25_ADDR_LEN);
+                digi->ndigi = d + 1;
+
+                if (buf[6] & AX25_HBIT) {
+                        digi->repeated[d] = 1;
+                        digi->lastrepeat  = d;
+                } else {
+                        digi->repeated[d] = 0;
+                }
+
+                buf += AX25_ADDR_LEN;
+                len -= AX25_ADDR_LEN;
+                d++;
+        }
+
+        return buf;
+}
+
+/*
+ *      Assemble an AX.25 header from the bits
+ */
+int ax25_addr_build(unsigned char *buf, ax25_address *src, ax25_address *dest, ax25_digi *d, int flag, int modulus)
+{
+        int len = 0;
+        int ct  = 0;
+
+        memcpy(buf, dest, AX25_ADDR_LEN);
+        buf[6] &= ~(AX25_EBIT | AX25_CBIT);
+        buf[6] |= AX25_SSSID_SPARE;
+
+        if (flag == AX25_COMMAND) buf[6] |= AX25_CBIT;
+
+        buf += AX25_ADDR_LEN;
+        len += AX25_ADDR_LEN;
+
+        memcpy(buf, src, AX25_ADDR_LEN);
+        buf[6] &= ~(AX25_EBIT | AX25_CBIT);
+        buf[6] &= ~AX25_SSSID_SPARE;
+
+        if (modulus == AX25_MODULUS)
+                buf[6] |= AX25_SSSID_SPARE;
+        else
+                buf[6] |= AX25_ESSID_SPARE;
+
+        if (flag == AX25_RESPONSE) buf[6] |= AX25_CBIT;
+
+        /*
+         *      Fast path the normal digiless path
+         */
+        if (d == NULL || d->ndigi == 0) {
+                buf[6] |= AX25_EBIT;
+                return 2 * AX25_ADDR_LEN;
+        }
+
+        buf += AX25_ADDR_LEN;
+        len += AX25_ADDR_LEN;
+
+        while (ct < d->ndigi) {
+                memcpy(buf, &d->calls[ct], AX25_ADDR_LEN);
+
+                if (d->repeated[ct])
+                        buf[6] |= AX25_HBIT;
+                else
+                        buf[6] &= ~AX25_HBIT;
+
+                buf[6] &= ~AX25_EBIT;
+                buf[6] |= AX25_SSSID_SPARE;
+
+                buf += AX25_ADDR_LEN;
+                len += AX25_ADDR_LEN;
+                ct++;
+        }
+
+        buf[-1] |= AX25_EBIT;
+
+        return len;
+}
+
+int ax25_addr_size(ax25_digi *dp)
+{
+        if (dp == NULL)
+                return 2 * AX25_ADDR_LEN;
+
+        return AX25_ADDR_LEN * (2 + dp->ndigi);
+}
+
+/*
+ *      Reverse Digipeat List. May not pass both parameters as same struct
+ */
+void ax25_digi_invert(ax25_digi *in, ax25_digi *out)
+{
+        int ct;
+
+        out->ndigi      = in->ndigi;
+        out->lastrepeat = in->ndigi - in->lastrepeat - 2;
+
+        /* Invert the digipeaters */
+        for (ct = 0; ct < in->ndigi; ct++) {
+                out->calls[ct] = in->calls[in->ndigi - ct - 1];
+
+                if (ct <= out->lastrepeat) {
+                        out->calls[ct].ax25_call[6] |= AX25_HBIT;
+                        out->repeated[ct]            = 1;
+                } else {
+                        out->calls[ct].ax25_call[6] &= ~AX25_HBIT;
+                        out->repeated[ct]            = 0;
+                }
+        }
+}
+