/* * 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/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 <asm/uaccess.h> #include <asm/system.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; /* 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, 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; } } }