Actually get all interface addresses

If we guessed a buffer size too small, we never increased the buffer and
tried again

Also simplify the interface of ifreq_to_smartlist a little
This commit is contained in:
Sebastian Hahn 2015-02-12 13:59:31 +01:00
parent 9667b2b88a
commit 87a95b0236
3 changed files with 26 additions and 17 deletions

View file

@ -1374,6 +1374,10 @@ get_interface_addresses_win32(int severity)
#ifdef HAVE_IFCONF_TO_SMARTLIST
/* Guess how much space we need. There shouldn't be any struct ifreqs
* larger than this, even on OS X where the struct's size is dynamic. */
#define IFREQ_SIZE 4096
/* This is defined on Mac OS X */
#ifndef _SIZEOF_ADDR_IFREQ
#define _SIZEOF_ADDR_IFREQ sizeof
@ -1383,7 +1387,7 @@ get_interface_addresses_win32(int severity)
* into smartlist of <b>tor_addr_t</b> structures.
*/
STATIC smartlist_t *
ifreq_to_smartlist(const struct ifreq *ifr, size_t buflen)
ifreq_to_smartlist(char *ifr, size_t buflen)
{
smartlist_t *result = smartlist_new();
@ -1415,8 +1419,7 @@ get_interface_addresses_ioctl(int severity)
{
/* Some older unixy systems make us use ioctl(SIOCGIFCONF) */
struct ifconf ifc;
int fd, sz;
void *databuf = NULL;
int fd;
smartlist_t *result = NULL;
/* This interface, AFAICT, only supports AF_INET addresses */
@ -1426,22 +1429,28 @@ get_interface_addresses_ioctl(int severity)
goto done;
}
/* Guess how much space we need. */
ifc.ifc_len = sz = 4096;
databuf = tor_malloc_zero(sz);
ifc.ifc_buf = databuf;
int mult = 1;
ifc.ifc_buf = NULL;
do {
mult *= 2;
ifc.ifc_len = mult * IFREQ_SIZE;
ifc.ifc_buf = tor_realloc(ifc.ifc_buf, ifc.ifc_len);
if (ioctl(fd, SIOCGIFCONF, &ifc) < 0) {
tor_log(severity, LD_NET, "ioctl failed: %s", strerror(errno));
close(fd);
goto done;
}
tor_assert(ifc.ifc_buf);
result = ifreq_to_smartlist(databuf, ifc.ifc_len);
if (ioctl(fd, SIOCGIFCONF, &ifc) < 0) {
tor_log(severity, LD_NET, "ioctl failed: %s", strerror(errno));
close(fd);
goto done;
}
/* Ensure we have least IFREQ_SIZE bytes unused at the end. Otherwise, we
* don't know if we got everything during ioctl. */
} while (mult * IFREQ_SIZE - ifc.ifc_len <= IFREQ_SIZE);
result = ifreq_to_smartlist(ifc.ifc_buf, ifc.ifc_len);
done:
close(fd);
tor_free(databuf);
tor_free(ifc.ifc_buf);
return result;
}
#endif

View file

@ -287,7 +287,7 @@ STATIC smartlist_t *get_interface_addresses_win32(int severity);
#endif
#ifdef HAVE_IFCONF_TO_SMARTLIST
STATIC smartlist_t *ifreq_to_smartlist(const struct ifreq *ifr,
STATIC smartlist_t *ifreq_to_smartlist(char *ifr,
size_t buflen);
STATIC smartlist_t *get_interface_addresses_ioctl(int severity);
#endif

View file

@ -375,7 +375,7 @@ test_address_ifreq_to_smartlist(void *arg)
ifc->ifc_len = sizeof(struct ifreq);
ifc->ifc_ifcu.ifcu_req = ifr;
results = ifreq_to_smartlist((struct ifreq *)ifc->ifc_buf,ifc->ifc_len);
results = ifreq_to_smartlist(ifc->ifc_buf,ifc->ifc_len);
tt_int_op(smartlist_len(results),==,1);
tor_addr = smartlist_get(results, 0);
@ -398,7 +398,7 @@ test_address_ifreq_to_smartlist(void *arg)
SMARTLIST_FOREACH(results, tor_addr_t *, t, tor_free(t));
smartlist_free(results);
results = ifreq_to_smartlist((struct ifreq *)ifc->ifc_buf,ifc->ifc_len);
results = ifreq_to_smartlist(ifc->ifc_buf,ifc->ifc_len);
tt_int_op(smartlist_len(results),==,2);
tor_addr = smartlist_get(results, 0);