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RIOT/sys/net/netif/netif_util.c
Benjamin Valentin 39951a948e net/netif: move gnrc_netif_addr_to/from_str() to netif
These functions are independent from GNRC and can be used by stack-agnistoc
code.
Avoid pulling in a GNRC dependency by moving those two helper functions to
`netif`.

The old function names are kept as `static inline` wrapper functions to avoid
breaking API users.
2020-08-16 23:52:32 +02:00

99 lines
2.2 KiB
C

/*
* Copyright (C) 2017 Freie Universität Berlin
*
* This file is subject to the terms and conditions of the GNU Lesser
* General Public License v2.1. See the file LICENSE in the top level
* directory for more details.
*/
/**
* @{
*
* @file
* @author Martine Lenders <m.lenders@fu-berlin.de>
*/
#include <assert.h>
#include "fmt.h"
char *netif_addr_to_str(const uint8_t *addr, size_t addr_len, char *out)
{
char *res = out;
assert((out != NULL) && ((addr != NULL) || (addr_len == 0U)));
out[0] = '\0';
for (size_t i = 0; i < addr_len; i++) {
out += fmt_byte_hex((out), *(addr++));
*(out++) = (i == (addr_len - 1)) ? '\0' : ':';
}
return res;
}
static inline int _dehex(char c, int default_)
{
if ('0' <= c && c <= '9') {
return c - '0';
}
else if ('A' <= c && c <= 'F') {
return c - 'A' + 10;
}
else if ('a' <= c && c <= 'f') {
return c - 'a' + 10;
}
else {
return default_;
}
}
size_t netif_addr_from_str(const char *str, uint8_t *out)
{
/* Walk over str from the end. */
/* Take two chars a time as one hex value (%hhx). */
/* Leading zeros can be omitted. */
/* Every non-hexadimal character is a delimiter. */
/* Leading, tailing and adjacent delimiters are forbidden. */
const char *end_str = str;
uint8_t *out_end = out;
size_t count = 0;
int assert_cell = 1;
assert(out != NULL);
if ((str == NULL) || (str[0] == '\0')) {
return 0;
}
/* find end of string */
while (end_str[1]) {
++end_str;
}
while (end_str >= str) {
int a = 0, b = _dehex(*end_str--, -1);
if (b < 0) {
if (assert_cell) {
return 0;
}
else {
assert_cell = 1;
continue;
}
}
assert_cell = 0;
if (end_str >= str) {
a = _dehex(*end_str--, 0);
}
count++;
*out_end++ = (a << 4) | b;
}
if (assert_cell) {
return 0;
}
/* out is reversed */
while (out < --out_end) {
uint8_t tmp = *out_end;
*out_end = *out;
*out++ = tmp;
}
return count;
}
/** @} */