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Correctly detect and exclude addresses outside of our virtual address range

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Found by cypherpunks; fixes more of 2328.  Bug was introduced in 3623a122;
first appeared in 0.2.0.5-alpha.
This commit is contained in:
Nick Mathewson 2011-01-07 12:18:37 -05:00
parent d6b49c55c5
commit 0a35ac6a22
2 changed files with 17 additions and 7 deletions
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3
changes/bug2328
View file

@ -5,4 +5,5 @@
- Correctly handle the case where AutomapHostsOnResolve is set but no
virtual addresses are available. Fixes bug2328, bugfix on
0.1.2.1-alpha. Bug found by doorss.
- Correctly handle wrapping around to when we run out of virtual address
space. Found by cypherpunks, bugfix on 0.2.0.5-alpha.

21
src/or/connection_edge.c
View file

@ -1139,6 +1139,18 @@ address_is_in_virtual_range(const char *address)
return 0;
}
/** Increment the value of next_virtual_addr; reset it to the start of the
* virtual address range if it wraps around.
*/
static INLINE void
increment_virtual_addr(void)
{
++next_virtual_addr;
if (addr_mask_cmp_bits(next_virtual_addr, virtual_addr_network,
virtual_addr_netmask_bits))
next_virtual_addr = virtual_addr_network;
}
/** Return a newly allocated string holding an address of <b>type</b>
* (one of RESOLVED_TYPE_{IPV4|HOSTNAME}) that has not yet been mapped,
* and that is very unlikely to be the address of any real host.
@ -1168,7 +1180,7 @@ addressmap_get_virtual_address(int type)
/* Don't hand out any .0 or .255 address. */
while ((next_virtual_addr & 0xff) == 0 ||
(next_virtual_addr & 0xff) == 0xff) {
++next_virtual_addr;
increment_virtual_addr();
if (! --available) {
log_warn(LD_CONFIG, "Ran out of virtual addresses!");
return NULL;
@ -1177,20 +1189,17 @@ addressmap_get_virtual_address(int type)
in.s_addr = htonl(next_virtual_addr);
tor_inet_ntoa(&in, buf, sizeof(buf));
if (!strmap_get(addressmap, buf)) {
++next_virtual_addr;
increment_virtual_addr();
break;
}
++next_virtual_addr;
increment_virtual_addr();
--available;
log_info(LD_CONFIG, "%d addrs available", (int)available);
if (! available) {
log_warn(LD_CONFIG, "Ran out of virtual addresses!");
return NULL;
}
if (addr_mask_cmp_bits(next_virtual_addr, virtual_addr_network,
virtual_addr_netmask_bits))
next_virtual_addr = virtual_addr_network;
}
return tor_strdup(buf);
} else {