Austin Blackstone / Mbed 2 deprecated client-lwip-lightswitch-demo-expanded

mbed client lightswitch demo

Dependencies:   mbed Socket lwip-eth lwip-sys lwip

Fork of mbed-client-classic-example-lwip by Austin Blackstone

nanostack-libservice/source/libip6string/ip6tos.c@11:cada08fc8a70, 2016-06-09 (annotated)

Committer:
mbedAustin
Date:
Thu Jun 09 17:08:36 2016 +0000
Revision:
11:cada08fc8a70
Commit for public Consumption

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mbedAustin 11:cada08fc8a70 1 /*
mbedAustin 11:cada08fc8a70 2 * Copyright (c) 2014-2015 ARM Limited. All rights reserved.
mbedAustin 11:cada08fc8a70 3 * SPDX-License-Identifier: Apache-2.0
mbedAustin 11:cada08fc8a70 4 * Licensed under the Apache License, Version 2.0 (the License); you may
mbedAustin 11:cada08fc8a70 5 * not use this file except in compliance with the License.
mbedAustin 11:cada08fc8a70 6 * You may obtain a copy of the License at
mbedAustin 11:cada08fc8a70 7 *
mbedAustin 11:cada08fc8a70 8 * http://www.apache.org/licenses/LICENSE-2.0
mbedAustin 11:cada08fc8a70 9 *
mbedAustin 11:cada08fc8a70 10 * Unless required by applicable law or agreed to in writing, software
mbedAustin 11:cada08fc8a70 11 * distributed under the License is distributed on an AS IS BASIS, WITHOUT
mbedAustin 11:cada08fc8a70 12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mbedAustin 11:cada08fc8a70 13 * See the License for the specific language governing permissions and
mbedAustin 11:cada08fc8a70 14 * limitations under the License.
mbedAustin 11:cada08fc8a70 15 */
mbedAustin 11:cada08fc8a70 16 #include <stdio.h>
mbedAustin 11:cada08fc8a70 17 #include <inttypes.h>
mbedAustin 11:cada08fc8a70 18 #include "ip6string.h"
mbedAustin 11:cada08fc8a70 19
mbedAustin 11:cada08fc8a70 20 /**
mbedAustin 11:cada08fc8a70 21 * Print binary IPv6 address to a string.
mbedAustin 11:cada08fc8a70 22 * String must contain enough room for full address, 40 bytes exact.
mbedAustin 11:cada08fc8a70 23 * IPv4 tunneling addresses are not covered.
mbedAustin 11:cada08fc8a70 24 * \param addr IPv6 address.
mbedAustin 11:cada08fc8a70 25 * \p buffer to write string to.
mbedAustin 11:cada08fc8a70 26 */
mbedAustin 11:cada08fc8a70 27 void ip6tos(const void *ip6addr, char *p)
mbedAustin 11:cada08fc8a70 28 {
mbedAustin 11:cada08fc8a70 29 uint_fast8_t zero_start = 255, zero_len = 1;
mbedAustin 11:cada08fc8a70 30 const uint8_t *addr = ip6addr;
mbedAustin 11:cada08fc8a70 31 uint_fast16_t part;
mbedAustin 11:cada08fc8a70 32
mbedAustin 11:cada08fc8a70 33 /* Follow RFC 5952 - pre-scan for longest run of zeros */
mbedAustin 11:cada08fc8a70 34 for (uint_fast8_t n = 0; n < 8; n++) {
mbedAustin 11:cada08fc8a70 35 part = *addr++;
mbedAustin 11:cada08fc8a70 36 part = (part << 8) | *addr++;
mbedAustin 11:cada08fc8a70 37 if (part != 0) {
mbedAustin 11:cada08fc8a70 38 continue;
mbedAustin 11:cada08fc8a70 39 }
mbedAustin 11:cada08fc8a70 40
mbedAustin 11:cada08fc8a70 41 /* We're at the start of a run of zeros - scan to non-zero (or end) */
mbedAustin 11:cada08fc8a70 42 uint_fast8_t n0 = n;
mbedAustin 11:cada08fc8a70 43 for (n = n0 + 1; n < 8; n++) {
mbedAustin 11:cada08fc8a70 44 part = *addr++;
mbedAustin 11:cada08fc8a70 45 part = (part << 8) | *addr++;
mbedAustin 11:cada08fc8a70 46 if (part != 0) {
mbedAustin 11:cada08fc8a70 47 break;
mbedAustin 11:cada08fc8a70 48 }
mbedAustin 11:cada08fc8a70 49 }
mbedAustin 11:cada08fc8a70 50
mbedAustin 11:cada08fc8a70 51 /* Now n0->initial zero of run, n->after final zero in run. Is this the
mbedAustin 11:cada08fc8a70 52 * longest run yet? If equal, we stick with the previous one - RFC 5952
mbedAustin 11:cada08fc8a70 53 * S4.2.3. Note that zero_len being initialised to 1 stops us
mbedAustin 11:cada08fc8a70 54 * shortening a 1-part run (S4.2.2.)
mbedAustin 11:cada08fc8a70 55 */
mbedAustin 11:cada08fc8a70 56 if (n - n0 > zero_len) {
mbedAustin 11:cada08fc8a70 57 zero_start = n0;
mbedAustin 11:cada08fc8a70 58 zero_len = n - n0;
mbedAustin 11:cada08fc8a70 59 }
mbedAustin 11:cada08fc8a70 60
mbedAustin 11:cada08fc8a70 61 /* Continue scan for initial zeros from part n+1 - we've already
mbedAustin 11:cada08fc8a70 62 * consumed part n, and know it's non-zero. */
mbedAustin 11:cada08fc8a70 63 }
mbedAustin 11:cada08fc8a70 64
mbedAustin 11:cada08fc8a70 65 /* Now go back and print, jumping over any zero run */
mbedAustin 11:cada08fc8a70 66 addr = ip6addr;
mbedAustin 11:cada08fc8a70 67 for (uint_fast8_t n = 0; n < 8;) {
mbedAustin 11:cada08fc8a70 68 if (n == zero_start) {
mbedAustin 11:cada08fc8a70 69 if (n == 0) {
mbedAustin 11:cada08fc8a70 70 *p++ = ':';
mbedAustin 11:cada08fc8a70 71 }
mbedAustin 11:cada08fc8a70 72 *p++ = ':';
mbedAustin 11:cada08fc8a70 73 addr += 2 * zero_len;
mbedAustin 11:cada08fc8a70 74 n += zero_len;
mbedAustin 11:cada08fc8a70 75 continue;
mbedAustin 11:cada08fc8a70 76 }
mbedAustin 11:cada08fc8a70 77
mbedAustin 11:cada08fc8a70 78 part = *addr++;
mbedAustin 11:cada08fc8a70 79 part = (part << 8) | *addr++;
mbedAustin 11:cada08fc8a70 80 n++;
mbedAustin 11:cada08fc8a70 81
mbedAustin 11:cada08fc8a70 82 p += sprintf(p, "%"PRIxFAST16, part);
mbedAustin 11:cada08fc8a70 83
mbedAustin 11:cada08fc8a70 84 /* One iteration writes "part:" rather than ":part", and has the
mbedAustin 11:cada08fc8a70 85 * explicit check for n == 8 below, to allow easy extension for
mbedAustin 11:cada08fc8a70 86 * IPv4-in-IPv6-type addresses ("xxxx::xxxx:a.b.c.d"): we'd just
mbedAustin 11:cada08fc8a70 87 * run the same loop for 6 parts, and output would then finish with the
mbedAustin 11:cada08fc8a70 88 * required : or ::, ready for "a.b.c.d" to be tacked on.
mbedAustin 11:cada08fc8a70 89 */
mbedAustin 11:cada08fc8a70 90 if (n != 8) {
mbedAustin 11:cada08fc8a70 91 *p++ = ':';
mbedAustin 11:cada08fc8a70 92 }
mbedAustin 11:cada08fc8a70 93 }
mbedAustin 11:cada08fc8a70 94 *p++ = '\0';
mbedAustin 11:cada08fc8a70 95 }