static void
dns_server_request_cb(struct evdns_server_request *req, void *data)
{
int i, r;
const char TEST_ARPA[] = "11.11.168.192.in-addr.arpa";
const char TEST_IN6[] =
"f.e.f.e." "0.0.0.0." "0.0.0.0." "1.1.1.1."
"a.a.a.a." "0.0.0.0." "0.0.0.0." "0.f.f.f.ip6.arpa";
for (i = 0; i < req->nquestions; ++i) {
const int qtype = req->questions[i]->type;
const int qclass = req->questions[i]->dns_question_class;
const char *qname = req->questions[i]->name;
struct in_addr ans;
ans.s_addr = htonl(0xc0a80b0bUL); /* 192.168.11.11 */
if (qtype == EVDNS_TYPE_A &&
qclass == EVDNS_CLASS_INET &&
!evutil_ascii_strcasecmp(qname, "zz.example.com")) {
r = evdns_server_request_add_a_reply(req, qname,
1, &ans.s_addr, 12345);
if (r<0)
dns_ok = 0;
} else if (qtype == EVDNS_TYPE_AAAA &&
qclass == EVDNS_CLASS_INET &&
!evutil_ascii_strcasecmp(qname, "zz.example.com")) {
char addr6[17] = "abcdefghijklmnop";
r = evdns_server_request_add_aaaa_reply(req,
qname, 1, addr6, 123);
if (r<0)
dns_ok = 0;
} else if (qtype == EVDNS_TYPE_PTR &&
qclass == EVDNS_CLASS_INET &&
!evutil_ascii_strcasecmp(qname, TEST_ARPA)) {
r = evdns_server_request_add_ptr_reply(req, NULL,
qname, "ZZ.EXAMPLE.COM", 54321);
if (r<0)
dns_ok = 0;
} else if (qtype == EVDNS_TYPE_PTR &&
qclass == EVDNS_CLASS_INET &&
!evutil_ascii_strcasecmp(qname, TEST_IN6)){
r = evdns_server_request_add_ptr_reply(req, NULL,
qname,
"ZZ-INET6.EXAMPLE.COM", 54322);
if (r<0)
dns_ok = 0;
} else if (qtype == EVDNS_TYPE_A &&
qclass == EVDNS_CLASS_INET &&
!evutil_ascii_strcasecmp(qname, "drop.example.com")) {
if (evdns_server_request_drop(req)<0)
dns_ok = 0;
return;
} else {
printf("Unexpected question %d %d \"%s\" ",
qtype, qclass, qname);
dns_ok = 0;
}
}
r = evdns_server_request_respond(req, 0);
if (r<0) {
printf("Couldn't send reply. ");
dns_ok = 0;
}
}
void
regress_dns_server_cb(struct evdns_server_request *req, void *data)
{
struct regress_dns_server_table *tab = data;
const char *question;
if (req->nquestions != 1)
TT_DIE(("Only handling one question at a time; got %d",
req->nquestions));
question = req->questions[0]->name;
while (tab->q && evutil_ascii_strcasecmp(question, tab->q) &&
strcmp("*", tab->q))
++tab;
if (tab->q == NULL)
TT_DIE(("Unexpected question: '%s'", question));
++tab->seen;
if (!strcmp(tab->anstype, "err")) {
int err = atoi(tab->ans);
tt_assert(! evdns_server_request_respond(req, err));
return;
} else if (!strcmp(tab->anstype, "errsoa")) {
int err = atoi(tab->ans);
char soa_record[] =
"\x04" "dns1" "\x05" "icann" "\x03" "org" "\0"
"\x0a" "hostmaster" "\x05" "icann" "\x03" "org" "\0"
"\x77\xde\x5e\xba" /* serial */
"\x00\x00\x1c\x20" /* refreshtime = 2h */
"\x00\x00\x0e\x10" /* retry = 1h */
"\x00\x12\x75\x00" /* expiration = 14d */
"\x00\x00\x0e\x10" /* min.ttl = 1h */
;
evdns_server_request_add_reply(
req, EVDNS_AUTHORITY_SECTION,
"example.com", EVDNS_TYPE_SOA, EVDNS_CLASS_INET,
42, sizeof(soa_record) - 1, 0, soa_record);
tt_assert(! evdns_server_request_respond(req, err));
return;
} else if (!strcmp(tab->anstype, "A")) {
struct in_addr in;
if (!evutil_inet_pton(AF_INET, tab->ans, &in)) {
TT_DIE(("Bad A value %s in table", tab->ans));
}
evdns_server_request_add_a_reply(req, question, 1, &in.s_addr,
100);
} else if (!strcmp(tab->anstype, "AAAA")) {
struct in6_addr in6;
if (!evutil_inet_pton(AF_INET6, tab->ans, &in6)) {
TT_DIE(("Bad AAAA value %s in table", tab->ans));
}
evdns_server_request_add_aaaa_reply(req,
question, 1, &in6.s6_addr, 100);
} else {
TT_DIE(("Weird table entry with type '%s'", tab->anstype));
}
tt_assert(! evdns_server_request_respond(req, 0))
return;
end:
tt_want(! evdns_server_request_drop(req));
}
/** Helper function: called by evdns whenever the client sends a request to our
* DNSPort. We need to eventually answer the request <b>req</b>.
*/
static void
evdns_server_callback(struct evdns_server_request *req, void *data_)
{
const listener_connection_t *listener = data_;
entry_connection_t *entry_conn;
edge_connection_t *conn;
int i = 0;
struct evdns_server_question *q = NULL, *supported_q = NULL;
struct sockaddr_storage addr;
struct sockaddr *sa;
int addrlen;
tor_addr_t tor_addr;
uint16_t port;
int err = DNS_ERR_NONE;
char *q_name;
tor_assert(req);
log_info(LD_APP, "Got a new DNS request!");
req->flags |= 0x80; /* set RA */
/* First, check whether the requesting address matches our SOCKSPolicy. */
if ((addrlen = evdns_server_request_get_requesting_addr(req,
(struct sockaddr*)&addr, (socklen_t)sizeof(addr))) < 0) {
log_warn(LD_APP, "Couldn't get requesting address.");
evdns_server_request_respond(req, DNS_ERR_SERVERFAILED);
return;
}
(void) addrlen;
sa = (struct sockaddr*) &addr;
if (tor_addr_from_sockaddr(&tor_addr, sa, &port)<0) {
log_warn(LD_APP, "Requesting address wasn't recognized.");
evdns_server_request_respond(req, DNS_ERR_SERVERFAILED);
return;
}
if (!socks_policy_permits_address(&tor_addr)) {
log_warn(LD_APP, "Rejecting DNS request from disallowed IP.");
evdns_server_request_respond(req, DNS_ERR_REFUSED);
return;
}
/* Now, let's find the first actual question of a type we can answer in this
* DNS request. It makes us a little noncompliant to act like this; we
* should fix that eventually if it turns out to make a difference for
* anybody. */
if (req->nquestions == 0) {
log_info(LD_APP, "No questions in DNS request; sending back nil reply.");
evdns_server_request_respond(req, 0);
return;
}
if (req->nquestions > 1) {
log_info(LD_APP, "Got a DNS request with more than one question; I only "
"handle one question at a time for now. Skipping the extras.");
}
for (i = 0; i < req->nquestions; ++i) {
if (req->questions[i]->dns_question_class != EVDNS_CLASS_INET)
continue;
if (! q)
q = req->questions[i];
switch (req->questions[i]->type) {
case EVDNS_TYPE_A:
case EVDNS_TYPE_AAAA:
case EVDNS_TYPE_PTR:
/* We always pick the first one of these questions, if there is
one. */
if (! supported_q)
supported_q = q;
break;
default:
break;
}
}
if (supported_q)
q = supported_q;
if (!q) {
log_info(LD_APP, "None of the questions we got were ones we're willing "
"to support. Sending NOTIMPL.");
evdns_server_request_respond(req, DNS_ERR_NOTIMPL);
return;
}
/* Make sure the name isn't too long: This should be impossible, I think. */
if (err == DNS_ERR_NONE && strlen(q->name) > MAX_SOCKS_ADDR_LEN-1)
err = DNS_ERR_FORMAT;
if (err != DNS_ERR_NONE || !supported_q) {
/* We got an error? There's no question we're willing to answer? Then
* send back an answer immediately; we're done. */
evdns_server_request_respond(req, err);
return;
}
/* Make a new dummy AP connection, and attach the request to it. */
entry_conn = entry_connection_new(CONN_TYPE_AP, AF_INET);
conn = ENTRY_TO_EDGE_CONN(entry_conn);
CONNECTION_AP_EXPECT_NONPENDING(entry_conn);
TO_CONN(conn)->state = AP_CONN_STATE_RESOLVE_WAIT;
conn->is_dns_request = 1;
tor_addr_copy(&TO_CONN(conn)->addr, &tor_addr);
TO_CONN(conn)->port = port;
TO_CONN(conn)->address = tor_dup_addr(&tor_addr);
if (q->type == EVDNS_TYPE_A || q->type == EVDNS_TYPE_AAAA ||
q->type == EVDNS_QTYPE_ALL) {
entry_conn->socks_request->command = SOCKS_COMMAND_RESOLVE;
} else {
tor_assert(q->type == EVDNS_TYPE_PTR);
entry_conn->socks_request->command = SOCKS_COMMAND_RESOLVE_PTR;
}
if (q->type == EVDNS_TYPE_A || q->type == EVDNS_QTYPE_ALL) {
entry_conn->entry_cfg.ipv4_traffic = 1;
entry_conn->entry_cfg.ipv6_traffic = 0;
entry_conn->entry_cfg.prefer_ipv6 = 0;
} else if (q->type == EVDNS_TYPE_AAAA) {
entry_conn->entry_cfg.ipv4_traffic = 0;
entry_conn->entry_cfg.ipv6_traffic = 1;
entry_conn->entry_cfg.prefer_ipv6 = 1;
}
strlcpy(entry_conn->socks_request->address, q->name,
sizeof(entry_conn->socks_request->address));
entry_conn->socks_request->listener_type = listener->base_.type;
entry_conn->dns_server_request = req;
entry_conn->entry_cfg.isolation_flags = listener->entry_cfg.isolation_flags;
entry_conn->entry_cfg.session_group = listener->entry_cfg.session_group;
entry_conn->nym_epoch = get_signewnym_epoch();
if (connection_add(ENTRY_TO_CONN(entry_conn)) < 0) {
log_warn(LD_APP, "Couldn't register dummy connection for DNS request");
evdns_server_request_respond(req, DNS_ERR_SERVERFAILED);
connection_free(ENTRY_TO_CONN(entry_conn));
return;
}
control_event_stream_status(entry_conn, STREAM_EVENT_NEW_RESOLVE, 0);
/* Now, unless a controller asked us to leave streams unattached,
* throw the connection over to get rewritten (which will
* answer it immediately if it's in the cache, or completely bogus, or
* automapped), and then attached to a circuit. */
log_info(LD_APP, "Passing request for %s to rewrite_and_attach.",
escaped_safe_str_client(q->name));
q_name = tor_strdup(q->name); /* q could be freed in rewrite_and_attach */
connection_ap_rewrite_and_attach_if_allowed(entry_conn, NULL, NULL);
/* Now, the connection is marked if it was bad. */
log_info(LD_APP, "Passed request for %s to rewrite_and_attach_if_allowed.",
escaped_safe_str_client(q_name));
tor_free(q_name);
}
static void
_f4dns_cb_dnsserver(struct evdns_server_request *req, void *_ctx) {
assert( _ctx != NULL );
f4dns_ctx_t *ctx = (f4dns_ctx_t *)_ctx;
int i;
for( i = 0; i < req->nquestions; i++ ) {
char op_id[20];
char *r_type;
char *r_fqdn = req->questions[i]->name;
switch( req->questions[i]->type ) {
case EVDNS_TYPE_A:
r_type = "A";
break;
case EVDNS_TYPE_AAAA:
r_type = "AAAA";
break;
case EVDNS_TYPE_MX:
r_type = "MX";
break;
case EVDNS_TYPE_NS:
r_type = "NS";
break;
case EVDNS_TYPE_PTR:
r_type = "PTR";
break;
case EVDNS_TYPE_SOA:
r_type = "SOA";
break;
case EVDNS_TYPE_TXT:
r_type = "TXT";
break;
default:
// XXX: No dude, we shouldn't do this!
r_type = "ANY";
break;
}
f4dns_hash(r_fqdn, op_id);
f4op_t *op = f4op_new(ctx->f4->op_ctx, F4OP_MODE_GET, op_id);
if( ! op ) {
f4_log(ctx->f4, "XXX: Couldn't initialize op!");
assert( false );
f4op_free(ctx->f4->op_ctx, op);
evdns_server_request_respond(req, 0);
}
else {
assert( op->dns_callback != NULL );
op->type = strdup(r_type);
op->fqn = strdup(r_fqdn);
op->dns_callback(ctx->f4->op_ctx, op, req);
f4op_add(ctx->f4->op_ctx, op);
}
}
}
