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Move address map into its own file.

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This commit is contained in:
Nick Mathewson 2012-10-28 16:13:58 -04:00
parent 2cb82c33bc
commit 7908ab2093
13 changed files with 1013 additions and 967 deletions
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3
changes/split_addressmap Normal file
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o Code simplification and refactoring:
- Move the client-side address-map/virtual-address/DNS-cache code
out of connection_edge.c into a new addressmap.c module.

958
src/or/addressmap.c Normal file
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/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2012, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#include "or.h"
#include "addressmap.h"
#include "circuituse.h"
#include "config.h"
#include "connection_edge.h"
#include "control.h"
#include "dns.h"
#include "routerset.h"
#include "nodelist.h"
/** A client-side struct to remember requests to rewrite addresses
* to new addresses. These structs are stored in the hash table
* "addressmap" below.
*
* There are 5 ways to set an address mapping:
* - A MapAddress command from the controller [permanent]
* - An AddressMap directive in the torrc [permanent]
* - When a TrackHostExits torrc directive is triggered [temporary]
* - When a DNS resolve succeeds [temporary]
* - When a DNS resolve fails [temporary]
*
* When an addressmap request is made but one is already registered,
* the new one is replaced only if the currently registered one has
* no "new_address" (that is, it's in the process of DNS resolve),
* or if the new one is permanent (expires==0 or 1).
*
* (We overload the 'expires' field, using "0" for mappings set via
* the configuration file, "1" for mappings set from the control
* interface, and other values for DNS and TrackHostExit mappings that can
* expire.)
*
* A mapping may be 'wildcarded'. If "src_wildcard" is true, then
* any address that ends with a . followed by the key for this entry will
* get remapped by it. If "dst_wildcard" is also true, then only the
* matching suffix of such addresses will get replaced by new_address.
*/
typedef struct {
char *new_address;
time_t expires;
addressmap_entry_source_t source:3;
unsigned src_wildcard:1;
unsigned dst_wildcard:1;
short num_resolve_failures;
} addressmap_entry_t;
/** Entry for mapping addresses to which virtual address we mapped them to. */
typedef struct {
char *ipv4_address;
char *hostname_address;
} virtaddress_entry_t;
/** A hash table to store client-side address rewrite instructions. */
static strmap_t *addressmap=NULL;
/**
* Table mapping addresses to which virtual address, if any, we
* assigned them to.
*
* We maintain the following invariant: if [A,B] is in
* virtaddress_reversemap, then B must be a virtual address, and [A,B]
* must be in addressmap. We do not require that the converse hold:
* if it fails, then we could end up mapping two virtual addresses to
* the same address, which is no disaster.
**/
static strmap_t *virtaddress_reversemap=NULL;
/** Initialize addressmap. */
void
addressmap_init(void)
{
addressmap = strmap_new();
virtaddress_reversemap = strmap_new();
}
/** Free the memory associated with the addressmap entry <b>_ent</b>. */
static void
addressmap_ent_free(void *_ent)
{
addressmap_entry_t *ent;
if (!_ent)
return;
ent = _ent;
tor_free(ent->new_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b>. */
static void
addressmap_virtaddress_ent_free(void *_ent)
{
virtaddress_entry_t *ent;
if (!_ent)
return;
ent = _ent;
tor_free(ent->ipv4_address);
tor_free(ent->hostname_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b>. */
static void
addressmap_virtaddress_remove(const char *address, addressmap_entry_t *ent)
{
if (ent && ent->new_address &&
address_is_in_virtual_range(ent->new_address)) {
virtaddress_entry_t *ve =
strmap_get(virtaddress_reversemap, ent->new_address);
/*log_fn(LOG_NOTICE,"remove reverse mapping for %s",ent->new_address);*/
if (ve) {
if (!strcmp(address, ve->ipv4_address))
tor_free(ve->ipv4_address);
if (!strcmp(address, ve->hostname_address))
tor_free(ve->hostname_address);
if (!ve->ipv4_address && !ve->hostname_address) {
tor_free(ve);
strmap_remove(virtaddress_reversemap, ent->new_address);
}
}
}
}
/** Remove <b>ent</b> (which must be mapped to by <b>address</b>) from the
* client address maps. */
static void
addressmap_ent_remove(const char *address, addressmap_entry_t *ent)
{
addressmap_virtaddress_remove(address, ent);
addressmap_ent_free(ent);
}
/** Unregister all TrackHostExits mappings from any address to
* *.exitname.exit. */
void
clear_trackexithost_mappings(const char *exitname)
{
char *suffix = NULL;
if (!addressmap || !exitname)
return;
tor_asprintf(&suffix, ".%s.exit", exitname);
tor_strlower(suffix);
STRMAP_FOREACH_MODIFY(addressmap, address, addressmap_entry_t *, ent) {
if (ent->source == ADDRMAPSRC_TRACKEXIT &&
!strcmpend(ent->new_address, suffix)) {
addressmap_ent_remove(address, ent);
MAP_DEL_CURRENT(address);
}
} STRMAP_FOREACH_END;
tor_free(suffix);
}
/** Remove all TRACKEXIT mappings from the addressmap for which the target
* host is unknown or no longer allowed, or for which the source address
* is no longer in trackexithosts. */
void
addressmap_clear_excluded_trackexithosts(const or_options_t *options)
{
const routerset_t *allow_nodes = options->ExitNodes;
const routerset_t *exclude_nodes = options->ExcludeExitNodesUnion_;
if (!addressmap)
return;
if (routerset_is_empty(allow_nodes))
allow_nodes = NULL;
if (allow_nodes == NULL && routerset_is_empty(exclude_nodes))
return;
STRMAP_FOREACH_MODIFY(addressmap, address, addressmap_entry_t *, ent) {
size_t len;
const char *target = ent->new_address, *dot;
char *nodename;
const node_t *node;
if (!target) {
/* DNS resolving in progress */
continue;
} else if (strcmpend(target, ".exit")) {
/* Not a .exit mapping */
continue;
} else if (ent->source != ADDRMAPSRC_TRACKEXIT) {
/* Not a trackexit mapping. */
continue;
}
len = strlen(target);
if (len < 6)
continue; /* malformed. */
dot = target + len - 6; /* dot now points to just before .exit */
while (dot > target && *dot != '.')
dot--;
if (*dot == '.') dot++;
nodename = tor_strndup(dot, len-5-(dot-target));;
node = node_get_by_nickname(nodename, 0);
tor_free(nodename);
if (!node ||
(allow_nodes && !routerset_contains_node(allow_nodes, node)) ||
routerset_contains_node(exclude_nodes, node) ||
!hostname_in_track_host_exits(options, address)) {
/* We don't know this one, or we want to be rid of it. */
addressmap_ent_remove(address, ent);
MAP_DEL_CURRENT(address);
}
} STRMAP_FOREACH_END;
}
/** Remove all AUTOMAP mappings from the addressmap for which the
* source address no longer matches AutomapHostsSuffixes, which is
* no longer allowed by AutomapHostsOnResolve, or for which the
* target address is no longer in the virtual network. */
void
addressmap_clear_invalid_automaps(const or_options_t *options)
{
int clear_all = !options->AutomapHostsOnResolve;
const smartlist_t *suffixes = options->AutomapHostsSuffixes;
if (!addressmap)
return;
if (!suffixes)
clear_all = 1; /* This should be impossible, but let's be sure. */
STRMAP_FOREACH_MODIFY(addressmap, src_address, addressmap_entry_t *, ent) {
int remove = clear_all;
if (ent->source != ADDRMAPSRC_AUTOMAP)
continue; /* not an automap mapping. */
if (!remove) {
int suffix_found = 0;
SMARTLIST_FOREACH(suffixes, const char *, suffix, {
if (!strcasecmpend(src_address, suffix)) {
suffix_found = 1;
break;
}
});
if (!suffix_found)
remove = 1;
}
if (!remove && ! address_is_in_virtual_range(ent->new_address))
remove = 1;
if (remove) {
addressmap_ent_remove(src_address, ent);
MAP_DEL_CURRENT(src_address);
}
} STRMAP_FOREACH_END;
}
/** Remove all entries from the addressmap that were set via the
* configuration file or the command line. */
void
addressmap_clear_configured(void)
{
addressmap_get_mappings(NULL, 0, 0, 0);
}
/** Remove all entries from the addressmap that are set to expire, ever. */
void
addressmap_clear_transient(void)
{
addressmap_get_mappings(NULL, 2, TIME_MAX, 0);
}
/** Clean out entries from the addressmap cache that were
* added long enough ago that they are no longer valid.
*/
void
addressmap_clean(time_t now)
{
addressmap_get_mappings(NULL, 2, now, 0);
}
/** Free all the elements in the addressmap, and free the addressmap
* itself. */
void
addressmap_free_all(void)
{
strmap_free(addressmap, addressmap_ent_free);
addressmap = NULL;
strmap_free(virtaddress_reversemap, addressmap_virtaddress_ent_free);
virtaddress_reversemap = NULL;
}
/** Try to find a match for AddressMap expressions that use
* wildcard notation such as '*.c.d *.e.f' (so 'a.c.d' will map to 'a.e.f') or
* '*.c.d a.b.c' (so 'a.c.d' will map to a.b.c).
* Return the matching entry in AddressMap or NULL if no match is found.
* For expressions such as '*.c.d *.e.f', truncate <b>address</b> 'a.c.d'
* to 'a' before we return the matching AddressMap entry.
*
* This function does not handle the case where a pattern of the form "*.c.d"
* matches the address c.d -- that's done by the main addressmap_rewrite
* function.
*/
static addressmap_entry_t *
addressmap_match_superdomains(char *address)
{
addressmap_entry_t *val;
char *cp;
cp = address;
while ((cp = strchr(cp, '.'))) {
/* cp now points to a suffix of address that begins with a . */
val = strmap_get_lc(addressmap, cp+1);
if (val && val->src_wildcard) {
if (val->dst_wildcard)
*cp = '\0';
return val;
}
++cp;
}
return NULL;
}
/** Look at address, and rewrite it until it doesn't want any
* more rewrites; but don't get into an infinite loop.
* Don't write more than maxlen chars into address. Return true if the
* address changed; false otherwise. Set *<b>expires_out</b> to the
* expiry time of the result, or to <b>time_max</b> if the result does
* not expire.
*
* If <b>exit_source_out</b> is non-null, we set it as follows. If we the
* address starts out as a non-exit address, and we remap it to an .exit
* address at any point, then set *<b>exit_source_out</b> to the
* address_entry_source_t of the first such rule. Set *<b>exit_source_out</b>
* to ADDRMAPSRC_NONE if there is no such rewrite, or if the original address
* was a .exit.
*/
int
addressmap_rewrite(char *address, size_t maxlen, time_t *expires_out,
addressmap_entry_source_t *exit_source_out)
{
addressmap_entry_t *ent;
int rewrites;
time_t expires = TIME_MAX;
addressmap_entry_source_t exit_source = ADDRMAPSRC_NONE;
char *addr_orig = tor_strdup(address);
char *log_addr_orig = NULL;
for (rewrites = 0; rewrites < 16; rewrites++) {
int exact_match = 0;
log_addr_orig = tor_strdup(escaped_safe_str_client(address));
ent = strmap_get(addressmap, address);
if (!ent || !ent->new_address) {
ent = addressmap_match_superdomains(address);
} else {
if (ent->src_wildcard && !ent->dst_wildcard &&
!strcasecmp(address, ent->new_address)) {
/* This is a rule like *.example.com example.com, and we just got
* "example.com" */
goto done;
}
exact_match = 1;
}
if (!ent || !ent->new_address) {
goto done;
}
if (ent->dst_wildcard && !exact_match) {
strlcat(address, ".", maxlen);
strlcat(address, ent->new_address, maxlen);
} else {
strlcpy(address, ent->new_address, maxlen);
}
if (!strcmpend(address, ".exit") &&
strcmpend(addr_orig, ".exit") &&
exit_source == ADDRMAPSRC_NONE) {
exit_source = ent->source;
}
log_info(LD_APP, "Addressmap: rewriting %s to %s",
log_addr_orig, escaped_safe_str_client(address));
if (ent->expires > 1 && ent->expires < expires)
expires = ent->expires;
tor_free(log_addr_orig);
}
log_warn(LD_CONFIG,
"Loop detected: we've rewritten %s 16 times! Using it as-is.",
escaped_safe_str_client(address));
/* it's fine to rewrite a rewrite, but don't loop forever */
done:
tor_free(addr_orig);
tor_free(log_addr_orig);
if (exit_source_out)
*exit_source_out = exit_source;
if (expires_out)
*expires_out = TIME_MAX;
return (rewrites > 0);
}
/** If we have a cached reverse DNS entry for the address stored in the
* <b>maxlen</b>-byte buffer <b>address</b> (typically, a dotted quad) then
* rewrite to the cached value and return 1. Otherwise return 0. Set
* *<b>expires_out</b> to the expiry time of the result, or to <b>time_max</b>
* if the result does not expire. */
int
addressmap_rewrite_reverse(char *address, size_t maxlen, time_t *expires_out)
{
char *s, *cp;
addressmap_entry_t *ent;
int r = 0;
tor_asprintf(&s, "REVERSE[%s]", address);
ent = strmap_get(addressmap, s);
if (ent) {
cp = tor_strdup(escaped_safe_str_client(ent->new_address));
log_info(LD_APP, "Rewrote reverse lookup %s -> %s",
escaped_safe_str_client(s), cp);
tor_free(cp);
strlcpy(address, ent->new_address, maxlen);
r = 1;
}
if (expires_out)
*expires_out = (ent && ent->expires > 1) ? ent->expires : TIME_MAX;
tor_free(s);
return r;
}
/** Return 1 if <b>address</b> is already registered, else return 0. If address
* is already registered, and <b>update_expires</b> is non-zero, then update
* the expiry time on the mapping with update_expires if it is a
* mapping created by TrackHostExits. */
int
addressmap_have_mapping(const char *address, int update_expiry)
{
addressmap_entry_t *ent;
if (!(ent=strmap_get_lc(addressmap, address)))
return 0;
if (update_expiry && ent->source==ADDRMAPSRC_TRACKEXIT)
ent->expires=time(NULL) + update_expiry;
return 1;
}
/** Register a request to map <b>address</b> to <b>new_address</b>,
* which will expire on <b>expires</b> (or 0 if never expires from
* config file, 1 if never expires from controller, 2 if never expires
* (virtual address mapping) from the controller.)
*
* <b>new_address</b> should be a newly dup'ed string, which we'll use or
* free as appropriate. We will leave address alone.
*
* If <b>wildcard_addr</b> is true, then the mapping will match any address
* equal to <b>address</b>, or any address ending with a period followed by
* <b>address</b>. If <b>wildcard_addr</b> and <b>wildcard_new_addr</b> are
* both true, the mapping will rewrite addresses that end with
* ".<b>address</b>" into ones that end with ".<b>new_address</b>."
*
* If <b>new_address</b> is NULL, or <b>new_address</b> is equal to
* <b>address</b> and <b>wildcard_addr</b> is equal to
* <b>wildcard_new_addr</b>, remove any mappings that exist from
* <b>address</b>.
*
*
* It is an error to set <b>wildcard_new_addr</b> if <b>wildcard_addr</b> is
* not set. */
void
addressmap_register(const char *address, char *new_address, time_t expires,
addressmap_entry_source_t source,
const int wildcard_addr,
const int wildcard_new_addr)
{
addressmap_entry_t *ent;
if (wildcard_new_addr)
tor_assert(wildcard_addr);
ent = strmap_get(addressmap, address);
if (!new_address || (!strcasecmp(address,new_address) &&
wildcard_addr == wildcard_new_addr)) {
/* Remove the mapping, if any. */
tor_free(new_address);
if (ent) {
addressmap_ent_remove(address,ent);
strmap_remove(addressmap, address);
}
return;
}
if (!ent) { /* make a new one and register it */
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
strmap_set(addressmap, address, ent);
} else if (ent->new_address) { /* we need to clean up the old mapping. */
if (expires > 1) {
log_info(LD_APP,"Temporary addressmap ('%s' to '%s') not performed, "
"since it's already mapped to '%s'",
safe_str_client(address),
safe_str_client(new_address),
safe_str_client(ent->new_address));
tor_free(new_address);
return;
}
if (address_is_in_virtual_range(ent->new_address) &&
expires != 2) {
/* XXX This isn't the perfect test; we want to avoid removing
* mappings set from the control interface _as virtual mapping */
addressmap_virtaddress_remove(address, ent);
}
tor_free(ent->new_address);
} /* else { we have an in-progress resolve with no mapping. } */
ent->new_address = new_address;
ent->expires = expires==2 ? 1 : expires;
ent->num_resolve_failures = 0;
ent->source = source;
ent->src_wildcard = wildcard_addr ? 1 : 0;
ent->dst_wildcard = wildcard_new_addr ? 1 : 0;
log_info(LD_CONFIG, "Addressmap: (re)mapped '%s' to '%s'",
safe_str_client(address),
safe_str_client(ent->new_address));
control_event_address_mapped(address, ent->new_address, expires, NULL);
}
/** An attempt to resolve <b>address</b> failed at some OR.
* Increment the number of resolve failures we have on record
* for it, and then return that number.
*/
int
client_dns_incr_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (!ent) {
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
ent->expires = time(NULL) + MAX_DNS_ENTRY_AGE;
strmap_set(addressmap,address,ent);
}
if (ent->num_resolve_failures < SHORT_MAX)
++ent->num_resolve_failures; /* don't overflow */
log_info(LD_APP, "Address %s now has %d resolve failures.",
safe_str_client(address),
ent->num_resolve_failures);
return ent->num_resolve_failures;
}
/** If <b>address</b> is in the client DNS addressmap, reset
* the number of resolve failures we have on record for it.
* This is used when we fail a stream because it won't resolve:
* otherwise future attempts on that address will only try once.
*/
void
client_dns_clear_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (ent)
ent->num_resolve_failures = 0;
}
/** Record the fact that <b>address</b> resolved to <b>name</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
static void
client_dns_set_addressmap_impl(const char *address, const char *name,
const char *exitname,
int ttl)
{
/* <address>.<hex or nickname>.exit\0 or just <address>\0 */
char extendedaddress[MAX_SOCKS_ADDR_LEN+MAX_VERBOSE_NICKNAME_LEN+10];
/* 123.123.123.123.<hex or nickname>.exit\0 or just 123.123.123.123\0 */
char extendedval[INET_NTOA_BUF_LEN+MAX_VERBOSE_NICKNAME_LEN+10];
tor_assert(address);
tor_assert(name);
if (ttl<0)
ttl = DEFAULT_DNS_TTL;
else
ttl = dns_clip_ttl(ttl);
if (exitname) {
/* XXXX fails to ever get attempts to get an exit address of
* google.com.digest[=~]nickname.exit; we need a syntax for this that
* won't make strict RFC952-compliant applications (like us) barf. */
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s.%s.exit", address, exitname);
tor_snprintf(extendedval, sizeof(extendedval),
"%s.%s.exit", name, exitname);
} else {
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s", address);
tor_snprintf(extendedval, sizeof(extendedval),
"%s", name);
}
addressmap_register(extendedaddress, tor_strdup(extendedval),
time(NULL) + ttl, ADDRMAPSRC_DNS, 0, 0);
}
/** Record the fact that <b>address</b> resolved to <b>val</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
void
client_dns_set_addressmap(const char *address, uint32_t val,
const char *exitname,
int ttl)
{
struct in_addr in;
char valbuf[INET_NTOA_BUF_LEN];
tor_assert(address);
if (tor_inet_aton(address, &in))
return; /* If address was an IP address already, don't add a mapping. */
in.s_addr = htonl(val);
tor_inet_ntoa(&in,valbuf,sizeof(valbuf));
client_dns_set_addressmap_impl(address, valbuf, exitname, ttl);
}
/** Add a cache entry noting that <b>address</b> (ordinarily a dotted quad)
* resolved via a RESOLVE_PTR request to the hostname <b>v</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
void
client_dns_set_reverse_addressmap(const char *address, const char *v,
const char *exitname,
int ttl)
{
char *s = NULL;
tor_asprintf(&s, "REVERSE[%s]", address);
client_dns_set_addressmap_impl(s, v, exitname, ttl);
tor_free(s);
}
/* By default, we hand out 127.192.0.1 through 127.254.254.254.
* These addresses should map to localhost, so even if the
* application accidentally tried to connect to them directly (not
* via Tor), it wouldn't get too far astray.
*
* These options are configured by parse_virtual_addr_network().
*/
/** Which network should we use for virtual IPv4 addresses? Only the first
* bits of this value are fixed. */
static uint32_t virtual_addr_network = 0x7fc00000u;
/** How many bits of <b>virtual_addr_network</b> are fixed? */
static maskbits_t virtual_addr_netmask_bits = 10;
/** What's the next virtual address we will hand out? */
static uint32_t next_virtual_addr = 0x7fc00000u;
/** Read a netmask of the form 127.192.0.0/10 from "val", and check whether
* it's a valid set of virtual addresses to hand out in response to MAPADDRESS
* requests. Return 0 on success; set *msg (if provided) to a newly allocated
* string and return -1 on failure. If validate_only is false, sets the
* actual virtual address range to the parsed value. */
int
parse_virtual_addr_network(const char *val, int validate_only,
char **msg)
{
uint32_t addr;
uint16_t port_min, port_max;
maskbits_t bits;
if (parse_addr_and_port_range(val, &addr, &bits, &port_min, &port_max)) {
if (msg) *msg = tor_strdup("Error parsing VirtualAddressNetwork");
return -1;
}
if (port_min != 1 || port_max != 65535) {
if (msg) *msg = tor_strdup("Can't specify ports on VirtualAddressNetwork");
return -1;
}
if (bits > 16) {
if (msg) *msg = tor_strdup("VirtualAddressNetwork expects a /16 "
"network or larger");
return -1;
}
if (validate_only)
return 0;
virtual_addr_network = (uint32_t)( addr & (0xfffffffful << (32-bits)) );
virtual_addr_netmask_bits = bits;
if (addr_mask_cmp_bits(next_virtual_addr, addr, bits))
next_virtual_addr = addr;
return 0;
}
/**
* Return true iff <b>addr</b> is likely to have been returned by
* client_dns_get_unused_address.
**/
int
address_is_in_virtual_range(const char *address)
{
struct in_addr in;
tor_assert(address);
if (!strcasecmpend(address, ".virtual")) {
return 1;
} else if (tor_inet_aton(address, &in)) {
uint32_t addr = ntohl(in.s_addr);
if (!addr_mask_cmp_bits(addr, virtual_addr_network,
virtual_addr_netmask_bits))
return 1;
}
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.
*
* May return NULL if we have run out of virtual addresses.
*/
static char *
addressmap_get_virtual_address(int type)
{
char buf[64];
tor_assert(addressmap);
if (type == RESOLVED_TYPE_HOSTNAME) {
char rand[10];
do {
crypto_rand(rand, sizeof(rand));
base32_encode(buf,sizeof(buf),rand,sizeof(rand));
strlcat(buf, ".virtual", sizeof(buf));
} while (strmap_get(addressmap, buf));
return tor_strdup(buf);
} else if (type == RESOLVED_TYPE_IPV4) {
// This is an imperfect estimate of how many addresses are available, but
// that's ok.
struct in_addr in;
uint32_t available = 1u << (32-virtual_addr_netmask_bits);
while (available) {
/* Don't hand out any .0 or .255 address. */
while ((next_virtual_addr & 0xff) == 0 ||
(next_virtual_addr & 0xff) == 0xff) {
increment_virtual_addr();
if (! --available) {
log_warn(LD_CONFIG, "Ran out of virtual addresses!");
return NULL;
}
}
in.s_addr = htonl(next_virtual_addr);
tor_inet_ntoa(&in, buf, sizeof(buf));
if (!strmap_get(addressmap, buf)) {
increment_virtual_addr();
break;
}
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;
}
}
return tor_strdup(buf);
} else {
log_warn(LD_BUG, "Called with unsupported address type (%d)", type);
return NULL;
}
}
/** A controller has requested that we map some address of type
* <b>type</b> to the address <b>new_address</b>. Choose an address
* that is unlikely to be used, and map it, and return it in a newly
* allocated string. If another address of the same type is already
* mapped to <b>new_address</b>, try to return a copy of that address.
*
* The string in <b>new_address</b> may be freed or inserted into a map
* as appropriate. May return NULL if are out of virtual addresses.
**/
const char *
addressmap_register_virtual_address(int type, char *new_address)
{
char **addrp;
virtaddress_entry_t *vent;
int vent_needs_to_be_added = 0;
tor_assert(new_address);
tor_assert(addressmap);
tor_assert(virtaddress_reversemap);
vent = strmap_get(virtaddress_reversemap, new_address);
if (!vent) {
vent = tor_malloc_zero(sizeof(virtaddress_entry_t));
vent_needs_to_be_added = 1;
}
addrp = (type == RESOLVED_TYPE_IPV4) ?
&vent->ipv4_address : &vent->hostname_address;
if (*addrp) {
addressmap_entry_t *ent = strmap_get(addressmap, *addrp);
if (ent && ent->new_address &&
!strcasecmp(new_address, ent->new_address)) {
tor_free(new_address);
tor_assert(!vent_needs_to_be_added);
return tor_strdup(*addrp);
} else
log_warn(LD_BUG,
"Internal confusion: I thought that '%s' was mapped to by "
"'%s', but '%s' really maps to '%s'. This is a harmless bug.",
safe_str_client(new_address),
safe_str_client(*addrp),
safe_str_client(*addrp),
ent?safe_str_client(ent->new_address):"(nothing)");
}
tor_free(*addrp);
*addrp = addressmap_get_virtual_address(type);
if (!*addrp) {
tor_free(vent);
tor_free(new_address);
return NULL;
}
log_info(LD_APP, "Registering map from %s to %s", *addrp, new_address);
if (vent_needs_to_be_added)
strmap_set(virtaddress_reversemap, new_address, vent);
addressmap_register(*addrp, new_address, 2, ADDRMAPSRC_AUTOMAP, 0, 0);
#if 0
{
/* Try to catch possible bugs */
addressmap_entry_t *ent;
ent = strmap_get(addressmap, *addrp);
tor_assert(ent);
tor_assert(!strcasecmp(ent->new_address,new_address));
vent = strmap_get(virtaddress_reversemap, new_address);
tor_assert(vent);
tor_assert(!strcasecmp(*addrp,
(type == RESOLVED_TYPE_IPV4) ?
vent->ipv4_address : vent->hostname_address));
log_info(LD_APP, "Map from %s to %s okay.",
safe_str_client(*addrp),
safe_str_client(new_address));
}
#endif
return *addrp;
}
/** Return 1 if <b>address</b> has funny characters in it like colons. Return
* 0 if it's fine, or if we're configured to allow it anyway. <b>client</b>
* should be true if we're using this address as a client; false if we're
* using it as a server.
*/
int
address_is_invalid_destination(const char *address, int client)
{
if (client) {
if (get_options()->AllowNonRFC953Hostnames)
return 0;
} else {
if (get_options()->ServerDNSAllowNonRFC953Hostnames)
return 0;
}
while (*address) {
if (TOR_ISALNUM(*address) ||
*address == '-' ||
*address == '.' ||
*address == '_') /* Underscore is not allowed, but Windows does it
* sometimes, just to thumb its nose at the IETF. */
++address;
else
return 1;
}
return 0;
}
/** Iterate over all address mappings which have expiry times between
* min_expires and max_expires, inclusive. If sl is provided, add an
* "old-addr new-addr expiry" string to sl for each mapping, omitting
* the expiry time if want_expiry is false. If sl is NULL, remove the
* mappings.
*/
void
addressmap_get_mappings(smartlist_t *sl, time_t min_expires,
time_t max_expires, int want_expiry)
{
strmap_iter_t *iter;
const char *key;
void *val_;
addressmap_entry_t *val;
if (!addressmap)
addressmap_init();
for (iter = strmap_iter_init(addressmap); !strmap_iter_done(iter); ) {
strmap_iter_get(iter, &key, &val_);
val = val_;
if (val->expires >= min_expires && val->expires <= max_expires) {
if (!sl) {
iter = strmap_iter_next_rmv(addressmap,iter);
addressmap_ent_remove(key, val);
continue;
} else if (val->new_address) {
const char *src_wc = val->src_wildcard ? "*." : "";
const char *dst_wc = val->dst_wildcard ? "*." : "";
if (want_expiry) {
if (val->expires < 3 || val->expires == TIME_MAX)
smartlist_add_asprintf(sl, "%s%s %s%s NEVER",
src_wc, key, dst_wc, val->new_address);
else {
char time[ISO_TIME_LEN+1];
format_iso_time(time, val->expires);
smartlist_add_asprintf(sl, "%s%s %s%s \"%s\"",
src_wc, key, dst_wc, val->new_address,
time);
}
} else {
smartlist_add_asprintf(sl, "%s%s %s%s",
src_wc, key, dst_wc, val->new_address);
}
}
}
iter = strmap_iter_next(addressmap,iter);
}
}

42
src/or/addressmap.h Normal file
View file

@ -0,0 +1,42 @@
/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2012, The Tor Project, Inc. */
/* See LICENSE for licensing information */
#ifndef TOR_ADDRESSMAP_H
#define TOR_ADDRESSMAP_H
void addressmap_init(void);
void addressmap_clear_excluded_trackexithosts(const or_options_t *options);
void addressmap_clear_invalid_automaps(const or_options_t *options);
void addressmap_clean(time_t now);
void addressmap_clear_configured(void);
void addressmap_clear_transient(void);
void addressmap_free_all(void);
int addressmap_rewrite(char *address, size_t maxlen, time_t *expires_out,
addressmap_entry_source_t *exit_source_out);
int addressmap_rewrite_reverse(char *address, size_t maxlen,
time_t *expires_out);
int addressmap_have_mapping(const char *address, int update_timeout);
void addressmap_register(const char *address, char *new_address,
time_t expires, addressmap_entry_source_t source,
const int address_wildcard,
const int new_address_wildcard);
int parse_virtual_addr_network(const char *val, int validate_only,
char **msg);
int client_dns_incr_failures(const char *address);
void client_dns_clear_failures(const char *address);
void client_dns_set_addressmap(const char *address, uint32_t val,
const char *exitname, int ttl);
const char *addressmap_register_virtual_address(int type, char *new_address);
void addressmap_get_mappings(smartlist_t *sl, time_t min_expires,
time_t max_expires, int want_expiry);
int address_is_in_virtual_range(const char *addr);
void clear_trackexithost_mappings(const char *exitname);
void client_dns_set_reverse_addressmap(const char *address, const char *v,
const char *exitname, int ttl);
#endif

1
src/or/buffers.c
View file

@ -12,6 +12,7 @@
**/ **/
#define BUFFERS_PRIVATE #define BUFFERS_PRIVATE
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "buffers.h" #include "buffers.h"
#include "config.h" #include "config.h"
#include "connection_edge.h" #include "connection_edge.h"

1
src/or/circuituse.c
View file

@ -10,6 +10,7 @@
**/ **/
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "channel.h" #include "channel.h"
#include "circuitbuild.h" #include "circuitbuild.h"
#include "circuitlist.h" #include "circuitlist.h"

1
src/or/config.c
View file

@ -12,6 +12,7 @@
#define CONFIG_PRIVATE #define CONFIG_PRIVATE
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "channel.h" #include "channel.h"
#include "circuitbuild.h" #include "circuitbuild.h"
#include "circuitlist.h" #include "circuitlist.h"

944
src/or/connection_edge.c
View file

@ -10,6 +10,7 @@
**/ **/
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "buffers.h" #include "buffers.h"
#include "channel.h" #include "channel.h"
#include "circuitlist.h" #include "circuitlist.h"
@ -56,9 +57,7 @@
static int connection_ap_handshake_process_socks(entry_connection_t *conn); static int connection_ap_handshake_process_socks(entry_connection_t *conn);
static int connection_ap_process_natd(entry_connection_t *conn); static int connection_ap_process_natd(entry_connection_t *conn);
static int connection_exit_connect_dir(edge_connection_t *exitconn); static int connection_exit_connect_dir(edge_connection_t *exitconn);
static int address_is_in_virtual_range(const char *addr);
static int consider_plaintext_ports(entry_connection_t *conn, uint16_t port); static int consider_plaintext_ports(entry_connection_t *conn, uint16_t port);
static void clear_trackexithost_mappings(const char *exitname);
static int connection_ap_supports_optimistic_data(const entry_connection_t *); static int connection_ap_supports_optimistic_data(const entry_connection_t *);
/** An AP stream has failed/finished. If it hasn't already sent back /** An AP stream has failed/finished. If it hasn't already sent back
@ -784,947 +783,6 @@ connection_ap_detach_retriable(entry_connection_t *conn,
} }
} }
/** A client-side struct to remember requests to rewrite addresses
* to new addresses. These structs are stored in the hash table
* "addressmap" below.
*
* There are 5 ways to set an address mapping:
* - A MapAddress command from the controller [permanent]
* - An AddressMap directive in the torrc [permanent]
* - When a TrackHostExits torrc directive is triggered [temporary]
* - When a DNS resolve succeeds [temporary]
* - When a DNS resolve fails [temporary]
*
* When an addressmap request is made but one is already registered,
* the new one is replaced only if the currently registered one has
* no "new_address" (that is, it's in the process of DNS resolve),
* or if the new one is permanent (expires==0 or 1).
*
* (We overload the 'expires' field, using "0" for mappings set via
* the configuration file, "1" for mappings set from the control
* interface, and other values for DNS and TrackHostExit mappings that can
* expire.)
*
* A mapping may be 'wildcarded'. If "src_wildcard" is true, then
* any address that ends with a . followed by the key for this entry will
* get remapped by it. If "dst_wildcard" is also true, then only the
* matching suffix of such addresses will get replaced by new_address.
*/
typedef struct {
char *new_address;
time_t expires;
addressmap_entry_source_t source:3;
unsigned src_wildcard:1;
unsigned dst_wildcard:1;
short num_resolve_failures;
} addressmap_entry_t;
/** Entry for mapping addresses to which virtual address we mapped them to. */
typedef struct {
char *ipv4_address;
char *hostname_address;
} virtaddress_entry_t;
/** A hash table to store client-side address rewrite instructions. */
static strmap_t *addressmap=NULL;
/**
* Table mapping addresses to which virtual address, if any, we
* assigned them to.
*
* We maintain the following invariant: if [A,B] is in
* virtaddress_reversemap, then B must be a virtual address, and [A,B]
* must be in addressmap. We do not require that the converse hold:
* if it fails, then we could end up mapping two virtual addresses to
* the same address, which is no disaster.
**/
static strmap_t *virtaddress_reversemap=NULL;
/** Initialize addressmap. */
void
addressmap_init(void)
{
addressmap = strmap_new();
virtaddress_reversemap = strmap_new();
}
/** Free the memory associated with the addressmap entry <b>_ent</b>. */
static void
addressmap_ent_free(void *_ent)
{
addressmap_entry_t *ent;
if (!_ent)
return;
ent = _ent;
tor_free(ent->new_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b>. */
static void
addressmap_virtaddress_ent_free(void *_ent)
{
virtaddress_entry_t *ent;
if (!_ent)
return;
ent = _ent;
tor_free(ent->ipv4_address);
tor_free(ent->hostname_address);
tor_free(ent);
}
/** Free storage held by a virtaddress_entry_t* entry in <b>ent</b>. */
static void
addressmap_virtaddress_remove(const char *address, addressmap_entry_t *ent)
{
if (ent && ent->new_address &&
address_is_in_virtual_range(ent->new_address)) {
virtaddress_entry_t *ve =
strmap_get(virtaddress_reversemap, ent->new_address);
/*log_fn(LOG_NOTICE,"remove reverse mapping for %s",ent->new_address);*/
if (ve) {
if (!strcmp(address, ve->ipv4_address))
tor_free(ve->ipv4_address);
if (!strcmp(address, ve->hostname_address))
tor_free(ve->hostname_address);
if (!ve->ipv4_address && !ve->hostname_address) {
tor_free(ve);
strmap_remove(virtaddress_reversemap, ent->new_address);
}
}
}
}
/** Remove <b>ent</b> (which must be mapped to by <b>address</b>) from the
* client address maps. */
static void
addressmap_ent_remove(const char *address, addressmap_entry_t *ent)
{
addressmap_virtaddress_remove(address, ent);
addressmap_ent_free(ent);
}
/** Unregister all TrackHostExits mappings from any address to
* *.exitname.exit. */
static void
clear_trackexithost_mappings(const char *exitname)
{
char *suffix = NULL;
if (!addressmap || !exitname)
return;
tor_asprintf(&suffix, ".%s.exit", exitname);
tor_strlower(suffix);
STRMAP_FOREACH_MODIFY(addressmap, address, addressmap_entry_t *, ent) {
if (ent->source == ADDRMAPSRC_TRACKEXIT &&
!strcmpend(ent->new_address, suffix)) {
addressmap_ent_remove(address, ent);
MAP_DEL_CURRENT(address);
}
} STRMAP_FOREACH_END;
tor_free(suffix);
}
/** Remove all TRACKEXIT mappings from the addressmap for which the target
* host is unknown or no longer allowed, or for which the source address
* is no longer in trackexithosts. */
void
addressmap_clear_excluded_trackexithosts(const or_options_t *options)
{
const routerset_t *allow_nodes = options->ExitNodes;
const routerset_t *exclude_nodes = options->ExcludeExitNodesUnion_;
if (!addressmap)
return;
if (routerset_is_empty(allow_nodes))
allow_nodes = NULL;
if (allow_nodes == NULL && routerset_is_empty(exclude_nodes))
return;
STRMAP_FOREACH_MODIFY(addressmap, address, addressmap_entry_t *, ent) {
size_t len;
const char *target = ent->new_address, *dot;
char *nodename;
const node_t *node;
if (!target) {
/* DNS resolving in progress */
continue;
} else if (strcmpend(target, ".exit")) {
/* Not a .exit mapping */
continue;
} else if (ent->source != ADDRMAPSRC_TRACKEXIT) {
/* Not a trackexit mapping. */
continue;
}
len = strlen(target);
if (len < 6)
continue; /* malformed. */
dot = target + len - 6; /* dot now points to just before .exit */
while (dot > target && *dot != '.')
dot--;
if (*dot == '.') dot++;
nodename = tor_strndup(dot, len-5-(dot-target));;
node = node_get_by_nickname(nodename, 0);
tor_free(nodename);
if (!node ||
(allow_nodes && !routerset_contains_node(allow_nodes, node)) ||
routerset_contains_node(exclude_nodes, node) ||
!hostname_in_track_host_exits(options, address)) {
/* We don't know this one, or we want to be rid of it. */
addressmap_ent_remove(address, ent);
MAP_DEL_CURRENT(address);
}
} STRMAP_FOREACH_END;
}
/** Remove all AUTOMAP mappings from the addressmap for which the
* source address no longer matches AutomapHostsSuffixes, which is
* no longer allowed by AutomapHostsOnResolve, or for which the
* target address is no longer in the virtual network. */
void
addressmap_clear_invalid_automaps(const or_options_t *options)
{
int clear_all = !options->AutomapHostsOnResolve;
const smartlist_t *suffixes = options->AutomapHostsSuffixes;
if (!addressmap)
return;
if (!suffixes)
clear_all = 1; /* This should be impossible, but let's be sure. */
STRMAP_FOREACH_MODIFY(addressmap, src_address, addressmap_entry_t *, ent) {
int remove = clear_all;
if (ent->source != ADDRMAPSRC_AUTOMAP)
continue; /* not an automap mapping. */
if (!remove) {
int suffix_found = 0;
SMARTLIST_FOREACH(suffixes, const char *, suffix, {
if (!strcasecmpend(src_address, suffix)) {
suffix_found = 1;
break;
}
});
if (!suffix_found)
remove = 1;
}
if (!remove && ! address_is_in_virtual_range(ent->new_address))
remove = 1;
if (remove) {
addressmap_ent_remove(src_address, ent);
MAP_DEL_CURRENT(src_address);
}
} STRMAP_FOREACH_END;
}
/** Remove all entries from the addressmap that were set via the
* configuration file or the command line. */
void
addressmap_clear_configured(void)
{
addressmap_get_mappings(NULL, 0, 0, 0);
}
/** Remove all entries from the addressmap that are set to expire, ever. */
void
addressmap_clear_transient(void)
{
addressmap_get_mappings(NULL, 2, TIME_MAX, 0);
}
/** Clean out entries from the addressmap cache that were
* added long enough ago that they are no longer valid.
*/
void
addressmap_clean(time_t now)
{
addressmap_get_mappings(NULL, 2, now, 0);
}
/** Free all the elements in the addressmap, and free the addressmap
* itself. */
void
addressmap_free_all(void)
{
strmap_free(addressmap, addressmap_ent_free);
addressmap = NULL;
strmap_free(virtaddress_reversemap, addressmap_virtaddress_ent_free);
virtaddress_reversemap = NULL;
}
/** Try to find a match for AddressMap expressions that use
* wildcard notation such as '*.c.d *.e.f' (so 'a.c.d' will map to 'a.e.f') or
* '*.c.d a.b.c' (so 'a.c.d' will map to a.b.c).
* Return the matching entry in AddressMap or NULL if no match is found.
* For expressions such as '*.c.d *.e.f', truncate <b>address</b> 'a.c.d'
* to 'a' before we return the matching AddressMap entry.
*
* This function does not handle the case where a pattern of the form "*.c.d"
* matches the address c.d -- that's done by the main addressmap_rewrite
* function.
*/
static addressmap_entry_t *
addressmap_match_superdomains(char *address)
{
addressmap_entry_t *val;
char *cp;
cp = address;
while ((cp = strchr(cp, '.'))) {
/* cp now points to a suffix of address that begins with a . */
val = strmap_get_lc(addressmap, cp+1);
if (val && val->src_wildcard) {
if (val->dst_wildcard)
*cp = '\0';
return val;
}
++cp;
}
return NULL;
}
/** Look at address, and rewrite it until it doesn't want any
* more rewrites; but don't get into an infinite loop.
* Don't write more than maxlen chars into address. Return true if the
* address changed; false otherwise. Set *<b>expires_out</b> to the
* expiry time of the result, or to <b>time_max</b> if the result does
* not expire.
*
* If <b>exit_source_out</b> is non-null, we set it as follows. If we the
* address starts out as a non-exit address, and we remap it to an .exit
* address at any point, then set *<b>exit_source_out</b> to the
* address_entry_source_t of the first such rule. Set *<b>exit_source_out</b>
* to ADDRMAPSRC_NONE if there is no such rewrite, or if the original address
* was a .exit.
*/
int
addressmap_rewrite(char *address, size_t maxlen, time_t *expires_out,
addressmap_entry_source_t *exit_source_out)
{
addressmap_entry_t *ent;
int rewrites;
time_t expires = TIME_MAX;
addressmap_entry_source_t exit_source = ADDRMAPSRC_NONE;
char *addr_orig = tor_strdup(address);
char *log_addr_orig = NULL;
for (rewrites = 0; rewrites < 16; rewrites++) {
int exact_match = 0;
log_addr_orig = tor_strdup(escaped_safe_str_client(address));
ent = strmap_get(addressmap, address);
if (!ent || !ent->new_address) {
ent = addressmap_match_superdomains(address);
} else {
if (ent->src_wildcard && !ent->dst_wildcard &&
!strcasecmp(address, ent->new_address)) {
/* This is a rule like *.example.com example.com, and we just got
* "example.com" */
goto done;
}
exact_match = 1;
}
if (!ent || !ent->new_address) {
goto done;
}
if (ent->dst_wildcard && !exact_match) {
strlcat(address, ".", maxlen);
strlcat(address, ent->new_address, maxlen);
} else {
strlcpy(address, ent->new_address, maxlen);
}
if (!strcmpend(address, ".exit") &&
strcmpend(addr_orig, ".exit") &&
exit_source == ADDRMAPSRC_NONE) {
exit_source = ent->source;
}
log_info(LD_APP, "Addressmap: rewriting %s to %s",
log_addr_orig, escaped_safe_str_client(address));
if (ent->expires > 1 && ent->expires < expires)
expires = ent->expires;
tor_free(log_addr_orig);
}
log_warn(LD_CONFIG,
"Loop detected: we've rewritten %s 16 times! Using it as-is.",
escaped_safe_str_client(address));
/* it's fine to rewrite a rewrite, but don't loop forever */
done:
tor_free(addr_orig);
tor_free(log_addr_orig);
if (exit_source_out)
*exit_source_out = exit_source;
if (expires_out)
*expires_out = TIME_MAX;
return (rewrites > 0);
}
/** If we have a cached reverse DNS entry for the address stored in the
* <b>maxlen</b>-byte buffer <b>address</b> (typically, a dotted quad) then
* rewrite to the cached value and return 1. Otherwise return 0. Set
* *<b>expires_out</b> to the expiry time of the result, or to <b>time_max</b>
* if the result does not expire. */
static int
addressmap_rewrite_reverse(char *address, size_t maxlen, time_t *expires_out)
{
char *s, *cp;
addressmap_entry_t *ent;
int r = 0;
tor_asprintf(&s, "REVERSE[%s]", address);
ent = strmap_get(addressmap, s);
if (ent) {
cp = tor_strdup(escaped_safe_str_client(ent->new_address));
log_info(LD_APP, "Rewrote reverse lookup %s -> %s",
escaped_safe_str_client(s), cp);
tor_free(cp);
strlcpy(address, ent->new_address, maxlen);
r = 1;
}
if (expires_out)
*expires_out = (ent && ent->expires > 1) ? ent->expires : TIME_MAX;
tor_free(s);
return r;
}
/** Return 1 if <b>address</b> is already registered, else return 0. If address
* is already registered, and <b>update_expires</b> is non-zero, then update
* the expiry time on the mapping with update_expires if it is a
* mapping created by TrackHostExits. */
int
addressmap_have_mapping(const char *address, int update_expiry)
{
addressmap_entry_t *ent;
if (!(ent=strmap_get_lc(addressmap, address)))
return 0;
if (update_expiry && ent->source==ADDRMAPSRC_TRACKEXIT)
ent->expires=time(NULL) + update_expiry;
return 1;
}
/** Register a request to map <b>address</b> to <b>new_address</b>,
* which will expire on <b>expires</b> (or 0 if never expires from
* config file, 1 if never expires from controller, 2 if never expires
* (virtual address mapping) from the controller.)
*
* <b>new_address</b> should be a newly dup'ed string, which we'll use or
* free as appropriate. We will leave address alone.
*
* If <b>wildcard_addr</b> is true, then the mapping will match any address
* equal to <b>address</b>, or any address ending with a period followed by
* <b>address</b>. If <b>wildcard_addr</b> and <b>wildcard_new_addr</b> are
* both true, the mapping will rewrite addresses that end with
* ".<b>address</b>" into ones that end with ".<b>new_address</b>."
*
* If <b>new_address</b> is NULL, or <b>new_address</b> is equal to
* <b>address</b> and <b>wildcard_addr</b> is equal to
* <b>wildcard_new_addr</b>, remove any mappings that exist from
* <b>address</b>.
*
*
* It is an error to set <b>wildcard_new_addr</b> if <b>wildcard_addr</b> is
* not set. */
void
addressmap_register(const char *address, char *new_address, time_t expires,
addressmap_entry_source_t source,
const int wildcard_addr,
const int wildcard_new_addr)
{
addressmap_entry_t *ent;
if (wildcard_new_addr)
tor_assert(wildcard_addr);
ent = strmap_get(addressmap, address);
if (!new_address || (!strcasecmp(address,new_address) &&
wildcard_addr == wildcard_new_addr)) {
/* Remove the mapping, if any. */
tor_free(new_address);
if (ent) {
addressmap_ent_remove(address,ent);
strmap_remove(addressmap, address);
}
return;
}
if (!ent) { /* make a new one and register it */
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
strmap_set(addressmap, address, ent);
} else if (ent->new_address) { /* we need to clean up the old mapping. */
if (expires > 1) {
log_info(LD_APP,"Temporary addressmap ('%s' to '%s') not performed, "
"since it's already mapped to '%s'",
safe_str_client(address),
safe_str_client(new_address),
safe_str_client(ent->new_address));
tor_free(new_address);
return;
}
if (address_is_in_virtual_range(ent->new_address) &&
expires != 2) {
/* XXX This isn't the perfect test; we want to avoid removing
* mappings set from the control interface _as virtual mapping */
addressmap_virtaddress_remove(address, ent);
}
tor_free(ent->new_address);
} /* else { we have an in-progress resolve with no mapping. } */
ent->new_address = new_address;
ent->expires = expires==2 ? 1 : expires;
ent->num_resolve_failures = 0;
ent->source = source;
ent->src_wildcard = wildcard_addr ? 1 : 0;
ent->dst_wildcard = wildcard_new_addr ? 1 : 0;
log_info(LD_CONFIG, "Addressmap: (re)mapped '%s' to '%s'",
safe_str_client(address),
safe_str_client(ent->new_address));
control_event_address_mapped(address, ent->new_address, expires, NULL);
}
/** An attempt to resolve <b>address</b> failed at some OR.
* Increment the number of resolve failures we have on record
* for it, and then return that number.
*/
int
client_dns_incr_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (!ent) {
ent = tor_malloc_zero(sizeof(addressmap_entry_t));
ent->expires = time(NULL) + MAX_DNS_ENTRY_AGE;
strmap_set(addressmap,address,ent);
}
if (ent->num_resolve_failures < SHORT_MAX)
++ent->num_resolve_failures; /* don't overflow */
log_info(LD_APP, "Address %s now has %d resolve failures.",
safe_str_client(address),
ent->num_resolve_failures);
return ent->num_resolve_failures;
}
/** If <b>address</b> is in the client DNS addressmap, reset
* the number of resolve failures we have on record for it.
* This is used when we fail a stream because it won't resolve:
* otherwise future attempts on that address will only try once.
*/
void
client_dns_clear_failures(const char *address)
{
addressmap_entry_t *ent = strmap_get(addressmap, address);
if (ent)
ent->num_resolve_failures = 0;
}
/** Record the fact that <b>address</b> resolved to <b>name</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
static void
client_dns_set_addressmap_impl(const char *address, const char *name,
const char *exitname,
int ttl)
{
/* <address>.<hex or nickname>.exit\0 or just <address>\0 */
char extendedaddress[MAX_SOCKS_ADDR_LEN+MAX_VERBOSE_NICKNAME_LEN+10];
/* 123.123.123.123.<hex or nickname>.exit\0 or just 123.123.123.123\0 */
char extendedval[INET_NTOA_BUF_LEN+MAX_VERBOSE_NICKNAME_LEN+10];
tor_assert(address);
tor_assert(name);
if (ttl<0)
ttl = DEFAULT_DNS_TTL;
else
ttl = dns_clip_ttl(ttl);
if (exitname) {
/* XXXX fails to ever get attempts to get an exit address of
* google.com.digest[=~]nickname.exit; we need a syntax for this that
* won't make strict RFC952-compliant applications (like us) barf. */
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s.%s.exit", address, exitname);
tor_snprintf(extendedval, sizeof(extendedval),
"%s.%s.exit", name, exitname);
} else {
tor_snprintf(extendedaddress, sizeof(extendedaddress),
"%s", address);
tor_snprintf(extendedval, sizeof(extendedval),
"%s", name);
}
addressmap_register(extendedaddress, tor_strdup(extendedval),
time(NULL) + ttl, ADDRMAPSRC_DNS, 0, 0);
}
/** Record the fact that <b>address</b> resolved to <b>val</b>.
* We can now use this in subsequent streams via addressmap_rewrite()
* so we can more correctly choose an exit that will allow <b>address</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
void
client_dns_set_addressmap(const char *address, uint32_t val,
const char *exitname,
int ttl)
{
struct in_addr in;
char valbuf[INET_NTOA_BUF_LEN];
tor_assert(address);
if (tor_inet_aton(address, &in))
return; /* If address was an IP address already, don't add a mapping. */
in.s_addr = htonl(val);
tor_inet_ntoa(&in,valbuf,sizeof(valbuf));
client_dns_set_addressmap_impl(address, valbuf, exitname, ttl);
}
/** Add a cache entry noting that <b>address</b> (ordinarily a dotted quad)
* resolved via a RESOLVE_PTR request to the hostname <b>v</b>.
*
* If <b>exitname</b> is defined, then append the addresses with
* ".exitname.exit" before registering the mapping.
*
* If <b>ttl</b> is nonnegative, the mapping will be valid for
* <b>ttl</b>seconds; otherwise, we use the default.
*/
static void
client_dns_set_reverse_addressmap(const char *address, const char *v,
const char *exitname,
int ttl)
{
char *s = NULL;
tor_asprintf(&s, "REVERSE[%s]", address);
client_dns_set_addressmap_impl(s, v, exitname, ttl);
tor_free(s);
}
/* By default, we hand out 127.192.0.1 through 127.254.254.254.
* These addresses should map to localhost, so even if the
* application accidentally tried to connect to them directly (not
* via Tor), it wouldn't get too far astray.
*
* These options are configured by parse_virtual_addr_network().
*/
/** Which network should we use for virtual IPv4 addresses? Only the first
* bits of this value are fixed. */
static uint32_t virtual_addr_network = 0x7fc00000u;
/** How many bits of <b>virtual_addr_network</b> are fixed? */
static maskbits_t virtual_addr_netmask_bits = 10;
/** What's the next virtual address we will hand out? */
static uint32_t next_virtual_addr = 0x7fc00000u;
/** Read a netmask of the form 127.192.0.0/10 from "val", and check whether
* it's a valid set of virtual addresses to hand out in response to MAPADDRESS
* requests. Return 0 on success; set *msg (if provided) to a newly allocated
* string and return -1 on failure. If validate_only is false, sets the
* actual virtual address range to the parsed value. */
int
parse_virtual_addr_network(const char *val, int validate_only,
char **msg)
{
uint32_t addr;
uint16_t port_min, port_max;
maskbits_t bits;
if (parse_addr_and_port_range(val, &addr, &bits, &port_min, &port_max)) {
if (msg) *msg = tor_strdup("Error parsing VirtualAddressNetwork");
return -1;
}
if (port_min != 1 || port_max != 65535) {
if (msg) *msg = tor_strdup("Can't specify ports on VirtualAddressNetwork");
return -1;
}
if (bits > 16) {
if (msg) *msg = tor_strdup("VirtualAddressNetwork expects a /16 "
"network or larger");
return -1;
}
if (validate_only)
return 0;
virtual_addr_network = (uint32_t)( addr & (0xfffffffful << (32-bits)) );
virtual_addr_netmask_bits = bits;
if (addr_mask_cmp_bits(next_virtual_addr, addr, bits))
next_virtual_addr = addr;
return 0;
}
/**
* Return true iff <b>addr</b> is likely to have been returned by
* client_dns_get_unused_address.
**/
static int
address_is_in_virtual_range(const char *address)
{
struct in_addr in;
tor_assert(address);
if (!strcasecmpend(address, ".virtual")) {
return 1;
} else if (tor_inet_aton(address, &in)) {
uint32_t addr = ntohl(in.s_addr);
if (!addr_mask_cmp_bits(addr, virtual_addr_network,
virtual_addr_netmask_bits))
return 1;
}
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.
*
* May return NULL if we have run out of virtual addresses.
*/
static char *
addressmap_get_virtual_address(int type)
{
char buf[64];
tor_assert(addressmap);
if (type == RESOLVED_TYPE_HOSTNAME) {
char rand[10];
do {
crypto_rand(rand, sizeof(rand));
base32_encode(buf,sizeof(buf),rand,sizeof(rand));
strlcat(buf, ".virtual", sizeof(buf));
} while (strmap_get(addressmap, buf));
return tor_strdup(buf);
} else if (type == RESOLVED_TYPE_IPV4) {
// This is an imperfect estimate of how many addresses are available, but
// that's ok.
struct in_addr in;
uint32_t available = 1u << (32-virtual_addr_netmask_bits);
while (available) {
/* Don't hand out any .0 or .255 address. */
while ((next_virtual_addr & 0xff) == 0 ||
(next_virtual_addr & 0xff) == 0xff) {
increment_virtual_addr();
if (! --available) {
log_warn(LD_CONFIG, "Ran out of virtual addresses!");
return NULL;
}
}
in.s_addr = htonl(next_virtual_addr);
tor_inet_ntoa(&in, buf, sizeof(buf));
if (!strmap_get(addressmap, buf)) {
increment_virtual_addr();
break;
}
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;
}
}
return tor_strdup(buf);
} else {
log_warn(LD_BUG, "Called with unsupported address type (%d)", type);
return NULL;
}
}
/** A controller has requested that we map some address of type
* <b>type</b> to the address <b>new_address</b>. Choose an address
* that is unlikely to be used, and map it, and return it in a newly
* allocated string. If another address of the same type is already
* mapped to <b>new_address</b>, try to return a copy of that address.
*
* The string in <b>new_address</b> may be freed or inserted into a map
* as appropriate. May return NULL if are out of virtual addresses.
**/
const char *
addressmap_register_virtual_address(int type, char *new_address)
{
char **addrp;
virtaddress_entry_t *vent;
int vent_needs_to_be_added = 0;
tor_assert(new_address);
tor_assert(addressmap);
tor_assert(virtaddress_reversemap);
vent = strmap_get(virtaddress_reversemap, new_address);
if (!vent) {
vent = tor_malloc_zero(sizeof(virtaddress_entry_t));
vent_needs_to_be_added = 1;
}
addrp = (type == RESOLVED_TYPE_IPV4) ?
&vent->ipv4_address : &vent->hostname_address;
if (*addrp) {
addressmap_entry_t *ent = strmap_get(addressmap, *addrp);
if (ent && ent->new_address &&
!strcasecmp(new_address, ent->new_address)) {
tor_free(new_address);
tor_assert(!vent_needs_to_be_added);
return tor_strdup(*addrp);
} else
log_warn(LD_BUG,
"Internal confusion: I thought that '%s' was mapped to by "
"'%s', but '%s' really maps to '%s'. This is a harmless bug.",
safe_str_client(new_address),
safe_str_client(*addrp),
safe_str_client(*addrp),
ent?safe_str_client(ent->new_address):"(nothing)");
}
tor_free(*addrp);
*addrp = addressmap_get_virtual_address(type);
if (!*addrp) {
tor_free(vent);
tor_free(new_address);
return NULL;
}
log_info(LD_APP, "Registering map from %s to %s", *addrp, new_address);
if (vent_needs_to_be_added)
strmap_set(virtaddress_reversemap, new_address, vent);
addressmap_register(*addrp, new_address, 2, ADDRMAPSRC_AUTOMAP, 0, 0);
#if 0
{
/* Try to catch possible bugs */
addressmap_entry_t *ent;
ent = strmap_get(addressmap, *addrp);
tor_assert(ent);
tor_assert(!strcasecmp(ent->new_address,new_address));
vent = strmap_get(virtaddress_reversemap, new_address);
tor_assert(vent);
tor_assert(!strcasecmp(*addrp,
(type == RESOLVED_TYPE_IPV4) ?
vent->ipv4_address : vent->hostname_address));
log_info(LD_APP, "Map from %s to %s okay.",
safe_str_client(*addrp),
safe_str_client(new_address));
}
#endif
return *addrp;
}
/** Return 1 if <b>address</b> has funny characters in it like colons. Return
* 0 if it's fine, or if we're configured to allow it anyway. <b>client</b>
* should be true if we're using this address as a client; false if we're
* using it as a server.
*/
int
address_is_invalid_destination(const char *address, int client)
{
if (client) {
if (get_options()->AllowNonRFC953Hostnames)
return 0;
} else {
if (get_options()->ServerDNSAllowNonRFC953Hostnames)
return 0;
}
while (*address) {
if (TOR_ISALNUM(*address) ||
*address == '-' ||
*address == '.' ||
*address == '_') /* Underscore is not allowed, but Windows does it
* sometimes, just to thumb its nose at the IETF. */
++address;
else
return 1;
}
return 0;
}
/** Iterate over all address mappings which have expiry times between
* min_expires and max_expires, inclusive. If sl is provided, add an
* "old-addr new-addr expiry" string to sl for each mapping, omitting
* the expiry time if want_expiry is false. If sl is NULL, remove the
* mappings.
*/
void
addressmap_get_mappings(smartlist_t *sl, time_t min_expires,
time_t max_expires, int want_expiry)
{
strmap_iter_t *iter;
const char *key;
void *val_;
addressmap_entry_t *val;
if (!addressmap)
addressmap_init();
for (iter = strmap_iter_init(addressmap); !strmap_iter_done(iter); ) {
strmap_iter_get(iter, &key, &val_);
val = val_;
if (val->expires >= min_expires && val->expires <= max_expires) {
if (!sl) {
iter = strmap_iter_next_rmv(addressmap,iter);
addressmap_ent_remove(key, val);
continue;
} else if (val->new_address) {
const char *src_wc = val->src_wildcard ? "*." : "";
const char *dst_wc = val->dst_wildcard ? "*." : "";
if (want_expiry) {
if (val->expires < 3 || val->expires == TIME_MAX)
smartlist_add_asprintf(sl, "%s%s %s%s NEVER",
src_wc, key, dst_wc, val->new_address);
else {
char time[ISO_TIME_LEN+1];
format_iso_time(time, val->expires);
smartlist_add_asprintf(sl, "%s%s %s%s \"%s\"",
src_wc, key, dst_wc, val->new_address,
time);
}
} else {
smartlist_add_asprintf(sl, "%s%s %s%s",
src_wc, key, dst_wc, val->new_address);
}
}
}
iter = strmap_iter_next(addressmap,iter);
}
}
/** Check if <b>conn</b> is using a dangerous port. Then warn and/or /** Check if <b>conn</b> is using a dangerous port. Then warn and/or
* reject depending on our config options. */ * reject depending on our config options. */

24
src/or/connection_edge.h
View file

@ -67,30 +67,6 @@ int connection_ap_process_transparent(entry_connection_t *conn);
int address_is_invalid_destination(const char *address, int client); int address_is_invalid_destination(const char *address, int client);
void addressmap_init(void);
void addressmap_clear_excluded_trackexithosts(const or_options_t *options);
void addressmap_clear_invalid_automaps(const or_options_t *options);
void addressmap_clean(time_t now);
void addressmap_clear_configured(void);
void addressmap_clear_transient(void);
void addressmap_free_all(void);
int addressmap_rewrite(char *address, size_t maxlen, time_t *expires_out,
addressmap_entry_source_t *exit_source_out);
int addressmap_have_mapping(const char *address, int update_timeout);
void addressmap_register(const char *address, char *new_address,
time_t expires, addressmap_entry_source_t source,
const int address_wildcard,
const int new_address_wildcard);
int parse_virtual_addr_network(const char *val, int validate_only,
char **msg);
int client_dns_incr_failures(const char *address);
void client_dns_clear_failures(const char *address);
void client_dns_set_addressmap(const char *address, uint32_t val,
const char *exitname, int ttl);
const char *addressmap_register_virtual_address(int type, char *new_address);
void addressmap_get_mappings(smartlist_t *sl, time_t min_expires,
time_t max_expires, int want_expiry);
int connection_ap_rewrite_and_attach_if_allowed(entry_connection_t *conn, int connection_ap_rewrite_and_attach_if_allowed(entry_connection_t *conn,
origin_circuit_t *circ, origin_circuit_t *circ,
crypt_path_t *cpath); crypt_path_t *cpath);

1
src/or/control.c
View file

@ -11,6 +11,7 @@
#define CONTROL_PRIVATE #define CONTROL_PRIVATE
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "buffers.h" #include "buffers.h"
#include "channel.h" #include "channel.h"
#include "channeltls.h" #include "channeltls.h"

2
src/or/include.am
View file

@ -16,6 +16,7 @@ evdns_source=src/ext/eventdns.c
endif endif
src_or_libtor_a_SOURCES = \ src_or_libtor_a_SOURCES = \
src/or/addressmap.c \
src/or/buffers.c \ src/or/buffers.c \
src/or/channel.c \ src/or/channel.c \
src/or/channeltls.c \ src/or/channeltls.c \
@ -91,6 +92,7 @@ src_or_tor_LDADD = src/or/libtor.a src/common/libor.a src/common/libor-crypto.a
@TOR_LIB_WS32@ @TOR_LIB_GDI@ @TOR_LIB_WS32@ @TOR_LIB_GDI@
ORHEADERS = \ ORHEADERS = \
src/or/addressmap.h \
src/or/buffers.h \ src/or/buffers.h \
src/or/channel.h \ src/or/channel.h \
src/or/channeltls.h \ src/or/channeltls.h \

1
src/or/main.c
View file

@ -12,6 +12,7 @@
#define MAIN_PRIVATE #define MAIN_PRIVATE
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "buffers.h" #include "buffers.h"
#include "channel.h" #include "channel.h"
#include "channeltls.h" #include "channeltls.h"

1
src/or/relay.c
View file

@ -12,6 +12,7 @@
#define RELAY_PRIVATE #define RELAY_PRIVATE
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "buffers.h" #include "buffers.h"
#include "channel.h" #include "channel.h"
#include "circuitbuild.h" #include "circuitbuild.h"

1
src/test/test_config.c
View file

@ -5,6 +5,7 @@
#include "orconfig.h" #include "orconfig.h"
#include "or.h" #include "or.h"
#include "addressmap.h"
#include "config.h" #include "config.h"
#include "confparse.h" #include "confparse.h"
#include "connection_edge.h" #include "connection_edge.h"