Systemd/src/basic/ether-addr-util.c

118 lines
4.2 KiB
C

/* SPDX-License-Identifier: LGPL-2.1+ */
#include <errno.h>
#include <net/ethernet.h>
#include <stdio.h>
#include <sys/types.h>
#include "ether-addr-util.h"
#include "macro.h"
#include "string-util.h"
char* ether_addr_to_string(const struct ether_addr *addr, char buffer[ETHER_ADDR_TO_STRING_MAX]) {
assert(addr);
assert(buffer);
/* Like ether_ntoa() but uses %02x instead of %x to print
* ethernet addresses, which makes them look less funny. Also,
* doesn't use a static buffer. */
sprintf(buffer, "%02x:%02x:%02x:%02x:%02x:%02x",
addr->ether_addr_octet[0],
addr->ether_addr_octet[1],
addr->ether_addr_octet[2],
addr->ether_addr_octet[3],
addr->ether_addr_octet[4],
addr->ether_addr_octet[5]);
return buffer;
}
int ether_addr_compare(const void *a, const void *b) {
assert(a);
assert(b);
return memcmp(a, b, ETH_ALEN);
}
static void ether_addr_hash_func(const void *p, struct siphash *state) {
siphash24_compress(p, sizeof(struct ether_addr), state);
}
const struct hash_ops ether_addr_hash_ops = {
.hash = ether_addr_hash_func,
.compare = ether_addr_compare
};
int ether_addr_from_string(const char *s, struct ether_addr *ret) {
size_t pos = 0, n, field;
char sep = '\0';
const char *hex = HEXDIGITS, *hexoff;
size_t x;
bool touched;
#define parse_fields(v) \
for (field = 0; field < ELEMENTSOF(v); field++) { \
touched = false; \
for (n = 0; n < (2 * sizeof(v[0])); n++) { \
if (s[pos] == '\0') \
break; \
hexoff = strchr(hex, s[pos]); \
if (!hexoff) \
break; \
assert(hexoff >= hex); \
x = hexoff - hex; \
if (x >= 16) \
x -= 6; /* A-F */ \
assert(x < 16); \
touched = true; \
v[field] <<= 4; \
v[field] += x; \
pos++; \
} \
if (!touched) \
return -EINVAL; \
if (field < (ELEMENTSOF(v)-1)) { \
if (s[pos] != sep) \
return -EINVAL; \
else \
pos++; \
} \
}
assert(s);
assert(ret);
s += strspn(s, WHITESPACE);
sep = s[strspn(s, hex)];
if (sep == '.') {
uint16_t shorts[3] = { 0 };
parse_fields(shorts);
if (s[pos] != '\0')
return -EINVAL;
for (n = 0; n < ELEMENTSOF(shorts); n++) {
ret->ether_addr_octet[2*n] = ((shorts[n] & (uint16_t)0xff00) >> 8);
ret->ether_addr_octet[2*n + 1] = (shorts[n] & (uint16_t)0x00ff);
}
} else if (IN_SET(sep, ':', '-')) {
struct ether_addr out = ETHER_ADDR_NULL;
parse_fields(out.ether_addr_octet);
if (s[pos] != '\0')
return -EINVAL;
for (n = 0; n < ELEMENTSOF(out.ether_addr_octet); n++)
ret->ether_addr_octet[n] = out.ether_addr_octet[n];
} else
return -EINVAL;
return 0;
}