iproute2/lib/dnet_ntop.c
Mike Frysinger 9ec0e899e1 dnet: fix strict aliasing warnings
Recent gcc doesn't like it when you cast char pointers to uint16_t
pointers and then dereference it.  So use memcpy() instead and let
gcc take care of optimizing things away (when appropriate).  This
should also fix alignment issues on arches where gcc packs the char
pointer tighter than 16bits.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-07-23 12:30:48 -07:00

103 lines
1.7 KiB
C

#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include "utils.h"
static __inline__ u_int16_t dn_ntohs(u_int16_t addr)
{
union {
u_int8_t byte[2];
u_int16_t word;
} u;
u.word = addr;
return ((u_int16_t)u.byte[0]) | (((u_int16_t)u.byte[1]) << 8);
}
static __inline__ int do_digit(char *str, u_int16_t *addr, u_int16_t scale, size_t *pos, size_t len, int *started)
{
u_int16_t tmp = *addr / scale;
if (*pos == len)
return 1;
if (((tmp) > 0) || *started || (scale == 1)) {
*str = tmp + '0';
*started = 1;
(*pos)++;
*addr -= (tmp * scale);
}
return 0;
}
static const char *dnet_ntop1(const struct dn_naddr *dna, char *str, size_t len)
{
u_int16_t addr, area;
size_t pos = 0;
int started = 0;
memcpy(&addr, dna->a_addr, sizeof(addr));
addr = dn_ntohs(addr);
area = addr >> 10;
if (dna->a_len != 2)
return NULL;
addr &= 0x03ff;
if (len == 0)
return str;
if (do_digit(str + pos, &area, 10, &pos, len, &started))
return str;
if (do_digit(str + pos, &area, 1, &pos, len, &started))
return str;
if (pos == len)
return str;
*(str + pos) = '.';
pos++;
started = 0;
if (do_digit(str + pos, &addr, 1000, &pos, len, &started))
return str;
if (do_digit(str + pos, &addr, 100, &pos, len, &started))
return str;
if (do_digit(str + pos, &addr, 10, &pos, len, &started))
return str;
if (do_digit(str + pos, &addr, 1, &pos, len, &started))
return str;
if (pos == len)
return str;
*(str + pos) = 0;
return str;
}
const char *dnet_ntop(int af, const void *addr, char *str, size_t len)
{
switch(af) {
case AF_DECnet:
errno = 0;
return dnet_ntop1((struct dn_naddr *)addr, str, len);
default:
errno = EAFNOSUPPORT;
}
return NULL;
}