/** Set *<b>out</b> to a newly allocated SOCKS4a resolve request with
* <b>username</b> and <b>hostname</b> as provided. Return the number
* of bytes in the request. */
static ssize_t
build_socks_resolve_request(char **out,
const char *username,
const char *hostname,
int reverse,
int version)
{
size_t len = 0;
tor_assert(out);
tor_assert(username);
tor_assert(hostname);
if (version == 4) {
len = 8 + strlen(username) + 1 + strlen(hostname) + 1;
*out = tor_malloc(len);
(*out)[0] = 4; /* SOCKS version 4 */
(*out)[1] = '\xF0'; /* Command: resolve. */
set_uint16((*out)+2, htons(0)); /* port: 0. */
set_uint32((*out)+4, htonl(0x00000001u)); /* addr: 0.0.0.1 */
memcpy((*out)+8, username, strlen(username)+1);
memcpy((*out)+8+strlen(username)+1, hostname, strlen(hostname)+1);
} else if (version == 5) {
int is_ip_address;
tor_addr_t addr;
size_t addrlen;
int ipv6;
is_ip_address = tor_addr_parse(&addr, hostname) != -1;
if (!is_ip_address && reverse) {
log_err(LD_GENERAL, "Tried to do a reverse lookup on a non-IP!");
return -1;
}
ipv6 = reverse && tor_addr_family(&addr) == AF_INET6;
addrlen = reverse ? (ipv6 ? 16 : 4) : 1 + strlen(hostname);
len = 6 + addrlen;
*out = tor_malloc(len);
(*out)[0] = 5; /* SOCKS version 5 */
(*out)[1] = reverse ? '\xF1' : '\xF0'; /* RESOLVE_PTR or RESOLVE */
(*out)[2] = 0; /* reserved. */
if (reverse) {
(*out)[3] = ipv6 ? 4 : 1;
if (ipv6)
memcpy((*out)+4, tor_addr_to_in6_addr8(&addr), 16);
else
set_uint32((*out)+4, tor_addr_to_ipv4n(&addr));
} else {
(*out)[3] = 3;
(*out)[4] = (char)(uint8_t)(addrlen - 1);
memcpy((*out)+5, hostname, addrlen - 1);
}
set_uint16((*out)+4+addrlen, 0); /* port */
} else {
tor_assert(0);
}
return len;
}
static void
test_address_tor_addr_to_ipv4n(void *ignored)
{
(void)ignored;
tor_addr_t *a = tor_malloc_zero(sizeof(tor_addr_t));
uint32_t res;
a->family = AF_INET6;
res = tor_addr_to_ipv4n(a);
tt_assert(!res);
a->family = AF_INET;
a->addr.in_addr.s_addr = 43;
res = tor_addr_to_ipv4n(a);
tt_assert(res);
tt_int_op(res, OP_EQ, 43);
done:
tor_free(a);
}
static void
update_difference(int ipv6, uint8_t *d,
const tor_addr_t *a, const tor_addr_t *b)
{
const int n_bytes = ipv6 ? 16 : 4;
uint8_t a_tmp[4], b_tmp[4];
const uint8_t *ba, *bb;
int i;
if (ipv6) {
ba = tor_addr_to_in6_addr8(a);
bb = tor_addr_to_in6_addr8(b);
} else {
set_uint32(a_tmp, tor_addr_to_ipv4n(a));
set_uint32(b_tmp, tor_addr_to_ipv4n(b));
ba = a_tmp; bb = b_tmp;
}
for (i = 0; i < n_bytes; ++i) {
d[i] |= ba[i] ^ bb[i];
}
}
/** Convert the tor_addr_t in <b>a</b>, with port in <b>port</b>, into a
* sockaddr object in *<b>sa_out</b> of object size <b>len</b>. If not enough
* room is available in sa_out, or on error, return 0. On success, return
* the length of the sockaddr.
*
* Interface note: ordinarily, we return -1 for error. We can't do that here,
* since socklen_t is unsigned on some platforms.
**/
socklen_t
tor_addr_to_sockaddr(const tor_addr_t *a,
uint16_t port,
struct sockaddr *sa_out,
socklen_t len)
{
sa_family_t family = tor_addr_family(a);
if (family == AF_INET) {
struct sockaddr_in *sin;
if (len < (int)sizeof(struct sockaddr_in))
return 0;
sin = (struct sockaddr_in *)sa_out;
memset(sin, 0, sizeof(struct sockaddr_in));
#ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
sin->sin_len = sizeof(struct sockaddr_in);
#endif
sin->sin_family = AF_INET;
sin->sin_port = htons(port);
sin->sin_addr.s_addr = tor_addr_to_ipv4n(a);
return sizeof(struct sockaddr_in);
} else if (family == AF_INET6) {
struct sockaddr_in6 *sin6;
if (len < (int)sizeof(struct sockaddr_in6))
return 0;
sin6 = (struct sockaddr_in6 *)sa_out;
memset(sin6, 0, sizeof(struct sockaddr_in6));
#ifdef HAVE_STRUCT_SOCKADDR_IN6_SIN6_LEN
sin6->sin6_len = sizeof(struct sockaddr_in6);
#endif
sin6->sin6_family = AF_INET6;
sin6->sin6_port = htons(port);
memcpy(&sin6->sin6_addr, tor_addr_to_in6(a), sizeof(struct in6_addr));
return sizeof(struct sockaddr_in6);
} else {
return 0;
}
}
/** Format the EXTEND{,2} cell in <b>cell_in</b>, storing its relay payload in
* <b>payload_out</b>, the number of bytes used in *<b>len_out</b>, and the
* relay command in *<b>command_out</b>. The <b>payload_out</b> must have
* RELAY_PAYLOAD_SIZE bytes available. Return 0 on success, -1 on failure. */
int
extend_cell_format(uint8_t *command_out, uint16_t *len_out,
uint8_t *payload_out, const extend_cell_t *cell_in)
{
uint8_t *p, *eop;
if (check_extend_cell(cell_in) < 0)
return -1;
p = payload_out;
eop = payload_out + RELAY_PAYLOAD_SIZE;
memset(p, 0, RELAY_PAYLOAD_SIZE);
switch (cell_in->cell_type) {
case RELAY_COMMAND_EXTEND:
{
*command_out = RELAY_COMMAND_EXTEND;
*len_out = 6 + TAP_ONIONSKIN_CHALLENGE_LEN + DIGEST_LEN;
set_uint32(p, tor_addr_to_ipv4n(&cell_in->orport_ipv4.addr));
set_uint16(p+4, ntohs(cell_in->orport_ipv4.port));
if (cell_in->create_cell.handshake_type == ONION_HANDSHAKE_TYPE_NTOR) {
memcpy(p+6, NTOR_CREATE_MAGIC, 16);
memcpy(p+22, cell_in->create_cell.onionskin, NTOR_ONIONSKIN_LEN);
} else {
memcpy(p+6, cell_in->create_cell.onionskin,
TAP_ONIONSKIN_CHALLENGE_LEN);
}
memcpy(p+6+TAP_ONIONSKIN_CHALLENGE_LEN, cell_in->node_id, DIGEST_LEN);
}
break;
case RELAY_COMMAND_EXTEND2:
{
uint8_t n = 2;
*command_out = RELAY_COMMAND_EXTEND2;
*p++ = n; /* 2 identifiers */
*p++ = SPECTYPE_IPV4; /* First is IPV4. */
*p++ = 6; /* It's 6 bytes long. */
set_uint32(p, tor_addr_to_ipv4n(&cell_in->orport_ipv4.addr));
set_uint16(p+4, htons(cell_in->orport_ipv4.port));
p += 6;
*p++ = SPECTYPE_LEGACY_ID; /* Next is an identity digest. */
*p++ = 20; /* It's 20 bytes long */
memcpy(p, cell_in->node_id, DIGEST_LEN);
p += 20;
/* Now we can send the handshake */
set_uint16(p, htons(cell_in->create_cell.handshake_type));
set_uint16(p+2, htons(cell_in->create_cell.handshake_len));
p += 4;
if (cell_in->create_cell.handshake_len > eop - p)
return -1;
memcpy(p, cell_in->create_cell.onionskin,
cell_in->create_cell.handshake_len);
p += cell_in->create_cell.handshake_len;
*len_out = p - payload_out;
}
break;
default:
return -1;
}
return 0;
}
/** Format the EXTEND{,2} cell in <b>cell_in</b>, storing its relay payload in
* <b>payload_out</b>, the number of bytes used in *<b>len_out</b>, and the
* relay command in *<b>command_out</b>. The <b>payload_out</b> must have
* RELAY_PAYLOAD_SIZE bytes available. Return 0 on success, -1 on failure. */
int
extend_cell_format(uint8_t *command_out, uint16_t *len_out,
uint8_t *payload_out, const extend_cell_t *cell_in)
{
uint8_t *p;
if (check_extend_cell(cell_in) < 0)
return -1;
p = payload_out;
memset(p, 0, RELAY_PAYLOAD_SIZE);
switch (cell_in->cell_type) {
case RELAY_COMMAND_EXTEND:
{
*command_out = RELAY_COMMAND_EXTEND;
*len_out = 6 + TAP_ONIONSKIN_CHALLENGE_LEN + DIGEST_LEN;
set_uint32(p, tor_addr_to_ipv4n(&cell_in->orport_ipv4.addr));
set_uint16(p+4, htons(cell_in->orport_ipv4.port));
if (cell_in->create_cell.handshake_type == ONION_HANDSHAKE_TYPE_NTOR) {
memcpy(p+6, NTOR_CREATE_MAGIC, 16);
memcpy(p+22, cell_in->create_cell.onionskin, NTOR_ONIONSKIN_LEN);
} else {
memcpy(p+6, cell_in->create_cell.onionskin,
TAP_ONIONSKIN_CHALLENGE_LEN);
}
memcpy(p+6+TAP_ONIONSKIN_CHALLENGE_LEN, cell_in->node_id, DIGEST_LEN);
}
break;
case RELAY_COMMAND_EXTEND2:
{
uint8_t n_specifiers = 2;
*command_out = RELAY_COMMAND_EXTEND2;
extend2_cell_body_t *cell = extend2_cell_body_new();
link_specifier_t *ls;
{
/* IPv4 specifier first. */
ls = link_specifier_new();
extend2_cell_body_add_ls(cell, ls);
ls->ls_type = LS_IPV4;
ls->ls_len = 6;
ls->un_ipv4_addr = tor_addr_to_ipv4h(&cell_in->orport_ipv4.addr);
ls->un_ipv4_port = cell_in->orport_ipv4.port;
}
{
/* Then RSA id */
ls = link_specifier_new();
extend2_cell_body_add_ls(cell, ls);
ls->ls_type = LS_LEGACY_ID;
ls->ls_len = DIGEST_LEN;
memcpy(ls->un_legacy_id, cell_in->node_id, DIGEST_LEN);
}
if (should_include_ed25519_id_extend_cells(NULL, get_options()) &&
!ed25519_public_key_is_zero(&cell_in->ed_pubkey)) {
/* Then, maybe, the ed25519 id! */
++n_specifiers;
ls = link_specifier_new();
extend2_cell_body_add_ls(cell, ls);
ls->ls_type = LS_ED25519_ID;
ls->ls_len = 32;
memcpy(ls->un_ed25519_id, cell_in->ed_pubkey.pubkey, 32);
}
cell->n_spec = n_specifiers;
/* Now, the handshake */
cell->create2 = create2_cell_body_new();
cell->create2->handshake_type = cell_in->create_cell.handshake_type;
cell->create2->handshake_len = cell_in->create_cell.handshake_len;
create2_cell_body_setlen_handshake_data(cell->create2,
cell_in->create_cell.handshake_len);
memcpy(create2_cell_body_getarray_handshake_data(cell->create2),
cell_in->create_cell.onionskin,
cell_in->create_cell.handshake_len);
ssize_t len_encoded = extend2_cell_body_encode(
payload_out, RELAY_PAYLOAD_SIZE,
cell);
extend2_cell_body_free(cell);
if (len_encoded < 0 || len_encoded > UINT16_MAX)
return -1;
*len_out = (uint16_t) len_encoded;
}
break;
default:
return -1;
}
return 0;
}
