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-rw-r--r--net/ax25/ax25_addr.c303
1 files changed, 303 insertions, 0 deletions
diff --git a/net/ax25/ax25_addr.c b/net/ax25/ax25_addr.c
new file mode 100644
index 000000000..f68865a4d
--- /dev/null
+++ b/net/ax25/ax25_addr.c
@@ -0,0 +1,303 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *
+ * 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/module.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 <linux/uaccess.h>
+#include <linux/fcntl.h>
+#include <linux/mm.h>
+#include <linux/interrupt.h>
+
+/*
+ * The default broadcast address of an interface is QST-0; the default address
+ * is LINUX-1. The null address is defined as a callsign of all spaces with
+ * an SSID of zero.
+ */
+
+const ax25_address ax25_bcast =
+ {{'Q' << 1, 'S' << 1, 'T' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
+const ax25_address ax25_defaddr =
+ {{'L' << 1, 'I' << 1, 'N' << 1, 'U' << 1, 'X' << 1, ' ' << 1, 1 << 1}};
+const ax25_address null_ax25_address =
+ {{' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, ' ' << 1, 0 << 1}};
+
+EXPORT_SYMBOL_GPL(ax25_bcast);
+EXPORT_SYMBOL_GPL(ax25_defaddr);
+EXPORT_SYMBOL(null_ax25_address);
+
+/*
+ * ax25 -> ascii conversion
+ */
+char *ax2asc(char *buf, const ax25_address *a)
+{
+ 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;
+
+}
+
+EXPORT_SYMBOL(ax2asc);
+
+/*
+ * ascii -> ax25 conversion
+ */
+void asc2ax(ax25_address *addr, const char *callsign)
+{
+ const 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->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;
+}
+
+EXPORT_SYMBOL(asc2ax);
+
+/*
+ * Compare two ax.25 addresses
+ */
+int ax25cmp(const ax25_address *a, const 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 */
+}
+
+EXPORT_SYMBOL(ax25cmp);
+
+/*
+ * Compare two AX.25 digipeater paths.
+ */
+int ax25digicmp(const ax25_digi *digi1, const 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
+ *
+ */
+const unsigned char *ax25_addr_parse(const 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;
+ if (len < AX25_ADDR_LEN)
+ return NULL;
+
+ 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, const ax25_address *src,
+ const ax25_address *dest, const 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(const 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(const 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;
+ }
+ }
+}