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SOCKS: refactor

This commit is contained in:
Přemysl Eric Janouch 2015-07-21 23:56:05 +02:00
parent e4af470639
commit 0fc8ea6a66
1 changed files with 181 additions and 169 deletions
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346
common.c
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@ -326,7 +326,7 @@ connector_add_target (struct connector *self,
// --- SOCKS 5/4a -------------------------------------------------------------- // --- SOCKS 5/4a --------------------------------------------------------------
// Asynchronous SOCKS connector. Adds more stuff on top of the original. // Asynchronous SOCKS connector. Adds more stuff on top of the regular one.
// Note that the `username' is used differently in SOCKS 4a and 5. In the // Note that the `username' is used differently in SOCKS 4a and 5. In the
// former version, it is the username that you can get ident'ed against. // former version, it is the username that you can get ident'ed against.
@ -396,7 +396,9 @@ struct socks_connector
uint16_t bound_port; ///< Bound port at the server uint16_t bound_port; ///< Bound port at the server
/// Process incoming data if there's enough of it available /// Process incoming data if there's enough of it available
bool (*on_data) (struct socks_connector *); bool (*on_data) (struct socks_connector *, struct msg_unpacker *);
size_t data_needed; ///< How much data the callback needs
// Configuration: // Configuration:
@ -436,76 +438,16 @@ struct socks_connector
return false; \ return false; \
BLOCK_END BLOCK_END
#define SOCKS_READ_START(n) \ #define SOCKS_DATA_CB(name) static bool name \
if (!socks_try_fill_read_buffer (self, (n))) \ (struct socks_connector *self, struct msg_unpacker *unpacker)
return false; \
if (self->read_buffer.len < n) \
return true; \
struct msg_unpacker unpacker; \
msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len)
#define SOCKS_READ_END \
str_remove_slice (&self->read_buffer, 0, unpacker.offset)
static bool
socks_try_fill_read_buffer (struct socks_connector *self, size_t n)
{
ssize_t remains = (ssize_t) n - (ssize_t) self->read_buffer.len;
if (remains <= 0)
return true;
ssize_t received;
str_ensure_space (&self->read_buffer, remains);
do
received = recv (self->socket_fd,
self->read_buffer.str + self->read_buffer.len, remains, 0);
while ((received == -1) && errno == EINTR);
if (received == 0)
SOCKS_FAIL ("%s: %s", "protocol error", "unexpected EOF");
if (received == -1 && errno != EAGAIN)
SOCKS_FAIL ("%s: %s", "recv", strerror (errno));
if (received > 0)
self->read_buffer.len += received;
return true;
}
static bool
socks_try_flush_write_buffer (struct socks_connector *self)
{
struct str *wb = &self->write_buffer;
ssize_t n_written;
while (wb->len)
{
n_written = send (self->socket_fd, wb->str, wb->len, 0);
if (n_written >= 0)
{
str_remove_slice (wb, 0, n_written);
continue;
}
if (errno == EAGAIN)
break;
if (errno == EINTR)
continue;
SOCKS_FAIL ("%s: %s", "send", strerror (errno));
return false;
}
return true;
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static bool SOCKS_DATA_CB (socks_4a_finish)
socks_4a_finish (struct socks_connector *self)
{ {
SOCKS_READ_START (8);
uint8_t null, status; uint8_t null, status;
hard_assert (msg_unpacker_u8 (&unpacker, &null)); hard_assert (msg_unpacker_u8 (unpacker, &null));
hard_assert (msg_unpacker_u8 (&unpacker, &status)); hard_assert (msg_unpacker_u8 (unpacker, &status));
SOCKS_READ_END;
if (null != 0) if (null != 0)
SOCKS_FAIL ("protocol error"); SOCKS_FAIL ("protocol error");
@ -571,79 +513,65 @@ socks_4a_start (struct socks_connector *self)
} }
self->on_data = socks_4a_finish; self->on_data = socks_4a_finish;
self->data_needed = 8;
return true; return true;
} }
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static bool SOCKS_DATA_CB (socks_5_request_port)
socks_5_request_port (struct socks_connector *self)
{ {
SOCKS_READ_START (2); hard_assert (msg_unpacker_u16 (unpacker, &self->bound_port));
hard_assert (msg_unpacker_u16 (&unpacker, &self->bound_port));
SOCKS_READ_END;
self->done = true; self->done = true;
return false; return false;
} }
static bool SOCKS_DATA_CB (socks_5_request_ipv4)
socks_5_request_ipv4 (struct socks_connector *self)
{ {
size_t len = sizeof self->bound_address.data.ipv4; memcpy (self->bound_address.data.ipv4,
SOCKS_READ_START (len); self->read_buffer.str, self->data_needed);
memcpy (self->bound_address.data.ipv4, self->read_buffer.str, len);
str_remove_slice (&self->read_buffer, 0, len);
self->on_data = socks_5_request_port; self->on_data = socks_5_request_port;
self->data_needed = 2;
return true; return true;
} }
static bool SOCKS_DATA_CB (socks_5_request_ipv6)
socks_5_request_ipv6 (struct socks_connector *self)
{ {
size_t len = sizeof self->bound_address.data.ipv6; memcpy (self->bound_address.data.ipv6,
SOCKS_READ_START (len); self->read_buffer.str, self->data_needed);
memcpy (self->bound_address.data.ipv6, self->read_buffer.str, len);
str_remove_slice (&self->read_buffer, 0, len);
self->on_data = socks_5_request_port; self->on_data = socks_5_request_port;
self->data_needed = 2;
return true; return true;
} }
static bool SOCKS_DATA_CB (socks_5_request_domain_data)
socks_5_request_domain_data (struct socks_connector *self)
{ {
size_t len = self->bound_address_len; self->bound_address.data.domain =
SOCKS_READ_START (len); xstrndup (self->read_buffer.str, self->data_needed);
self->bound_address.data.domain = xstrndup (self->read_buffer.str, len);
str_remove_slice (&self->read_buffer, 0, len);
self->on_data = socks_5_request_port; self->on_data = socks_5_request_port;
self->data_needed = 2;
return true; return true;
} }
static bool SOCKS_DATA_CB (socks_5_request_domain)
socks_5_request_domain (struct socks_connector *self)
{ {
SOCKS_READ_START (1); hard_assert (msg_unpacker_u8 (unpacker, &self->bound_address_len));
hard_assert (msg_unpacker_u8 (&unpacker, &self->bound_address_len));
SOCKS_READ_END;
self->on_data = socks_5_request_domain_data; self->on_data = socks_5_request_domain_data;
self->data_needed = self->bound_address_len;
return true; return true;
} }
static bool SOCKS_DATA_CB (socks_5_request_finish)
socks_5_request_finish (struct socks_connector *self)
{ {
SOCKS_READ_START (4);
uint8_t version, status, reserved, type; uint8_t version, status, reserved, type;
hard_assert (msg_unpacker_u8 (&unpacker, &version)); hard_assert (msg_unpacker_u8 (unpacker, &version));
hard_assert (msg_unpacker_u8 (&unpacker, &status)); hard_assert (msg_unpacker_u8 (unpacker, &status));
hard_assert (msg_unpacker_u8 (&unpacker, &reserved)); hard_assert (msg_unpacker_u8 (unpacker, &reserved));
hard_assert (msg_unpacker_u8 (&unpacker, &type)); hard_assert (msg_unpacker_u8 (unpacker, &type));
SOCKS_READ_END;
if (version != 0x05) if (version != 0x05)
SOCKS_FAIL ("protocol error"); SOCKS_FAIL ("protocol error");
@ -665,10 +593,20 @@ socks_5_request_finish (struct socks_connector *self)
switch ((self->bound_address.type = type)) switch ((self->bound_address.type = type))
{ {
case SOCKS_IPV4: self->on_data = socks_5_request_ipv4; return true; case SOCKS_IPV4:
case SOCKS_IPV6: self->on_data = socks_5_request_ipv6; return true; self->on_data = socks_5_request_ipv4;
case SOCKS_DOMAIN: self->on_data = socks_5_request_domain; return true; self->data_needed = sizeof self->bound_address.data.ipv4;
default: SOCKS_FAIL ("protocol error"); return true;
case SOCKS_IPV6:
self->data_needed = sizeof self->bound_address.data.ipv6;
self->on_data = socks_5_request_ipv6;
return true;
case SOCKS_DOMAIN:
self->on_data = socks_5_request_domain;
self->data_needed = 1;
return true;
default:
SOCKS_FAIL ("protocol error");
} }
} }
@ -707,17 +645,17 @@ socks_5_request_start (struct socks_connector *self)
str_append_c (wb, target->port); str_append_c (wb, target->port);
self->on_data = socks_5_request_finish; self->on_data = socks_5_request_finish;
self->data_needed = 4;
return true; return true;
} }
static bool // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
socks_5_userpass_finish (struct socks_connector *self)
SOCKS_DATA_CB (socks_5_userpass_finish)
{ {
SOCKS_READ_START (2);
uint8_t version, status; uint8_t version, status;
hard_assert (msg_unpacker_u8 (&unpacker, &version)); hard_assert (msg_unpacker_u8 (unpacker, &version));
hard_assert (msg_unpacker_u8 (&unpacker, &status)); hard_assert (msg_unpacker_u8 (unpacker, &status));
SOCKS_READ_END;
if (version != 0x01) if (version != 0x01)
SOCKS_FAIL ("protocol error"); SOCKS_FAIL ("protocol error");
@ -745,17 +683,15 @@ socks_5_userpass_start (struct socks_connector *self)
str_append_data (wb, self->password, plen); str_append_data (wb, self->password, plen);
self->on_data = socks_5_userpass_finish; self->on_data = socks_5_userpass_finish;
self->data_needed = 2;
return true; return true;
} }
static bool SOCKS_DATA_CB (socks_5_auth_finish)
socks_5_auth_finish (struct socks_connector *self)
{ {
SOCKS_READ_START (2);
uint8_t version, method; uint8_t version, method;
hard_assert (msg_unpacker_u8 (&unpacker, &version)); hard_assert (msg_unpacker_u8 (unpacker, &version));
hard_assert (msg_unpacker_u8 (&unpacker, &method)); hard_assert (msg_unpacker_u8 (unpacker, &method));
SOCKS_READ_END;
if (version != 0x05) if (version != 0x05)
SOCKS_FAIL ("protocol error"); SOCKS_FAIL ("protocol error");
@ -791,12 +727,72 @@ socks_5_auth_start (struct socks_connector *self)
str_append_c (wb, 0x02); // username/password str_append_c (wb, 0x02); // username/password
self->on_data = socks_5_auth_finish; self->on_data = socks_5_auth_finish;
self->data_needed = 2;
return true; return true;
} }
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static void socks_connector_step (struct socks_connector *self); static void socks_connector_start (struct socks_connector *self);
static void
socks_connector_fail (struct socks_connector *self)
{
poller_fd_reset (&self->socket_event);
self->on_failure (self->user_data);
}
static bool
socks_connector_step_iterators (struct socks_connector *self)
{
// At the lowest level we iterate over all addresses for the SOCKS server;
// this is done automatically by the connector
// Then we iterate over available protocols
if (++self->protocol_iter != SOCKS_MAX)
return true;
// At the highest level we iterate over possible targets
self->protocol_iter = 0;
if (self->targets_iter && (self->targets_iter = self->targets_iter->next))
return true;
return false;
}
static void
socks_connector_step (struct socks_connector *self)
{
if (self->socket_fd != -1)
{
poller_fd_reset (&self->socket_event);
xclose (self->socket_fd);
self->socket_fd = -1;
}
if (self->connector)
{
connector_free (self->connector);
free (self->connector);
self->connector = NULL;
}
if (socks_connector_step_iterators (self))
socks_connector_start (self);
else
socks_connector_fail (self);
}
static void
socks_connector_on_timeout (struct socks_connector *self)
{
if (self->on_error)
self->on_error (self->user_data, "timeout");
socks_connector_fail (self);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static void static void
socks_connector_on_connected (void *user_data, int socket_fd) socks_connector_on_connected (void *user_data, int socket_fd)
@ -814,7 +810,7 @@ socks_connector_on_connected (void *user_data, int socket_fd)
|| (self->protocol_iter == SOCKS_4A && socks_4a_start (self))) || (self->protocol_iter == SOCKS_4A && socks_4a_start (self)))
return; return;
self->on_failure (self->user_data); socks_connector_fail (self);
} }
static void static void
@ -870,45 +866,71 @@ socks_connector_start (struct socks_connector *self)
self->done = false; self->done = false;
} }
static void // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
socks_connector_step (struct socks_connector *self)
static bool
socks_try_fill_read_buffer (struct socks_connector *self, size_t n)
{ {
// Close the socket if needed ssize_t remains = (ssize_t) n - (ssize_t) self->read_buffer.len;
if (self->socket_fd != -1) if (remains <= 0)
return true;
ssize_t received;
str_ensure_space (&self->read_buffer, remains);
do
received = recv (self->socket_fd,
self->read_buffer.str + self->read_buffer.len, remains, 0);
while ((received == -1) && errno == EINTR);
if (received == 0)
SOCKS_FAIL ("%s: %s", "protocol error", "unexpected EOF");
if (received == -1 && errno != EAGAIN)
SOCKS_FAIL ("%s: %s", "recv", strerror (errno));
if (received > 0)
self->read_buffer.len += received;
return true;
}
static bool
socks_call_on_data (struct socks_connector *self)
{
size_t to_consume = self->data_needed;
if (!socks_try_fill_read_buffer (self, to_consume))
return false;
if (self->read_buffer.len < to_consume)
return true;
struct msg_unpacker unpacker;
msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len);
bool result = self->on_data (self, &unpacker);
str_remove_slice (&self->read_buffer, 0, to_consume);
return result;
}
static bool
socks_try_flush_write_buffer (struct socks_connector *self)
{
struct str *wb = &self->write_buffer;
ssize_t n_written;
while (wb->len)
{ {
poller_fd_reset (&self->socket_event); n_written = send (self->socket_fd, wb->str, wb->len, 0);
xclose (self->socket_fd); if (n_written >= 0)
self->socket_fd = -1; {
str_remove_slice (wb, 0, n_written);
continue;
} }
// Destroy current connector if needed if (errno == EAGAIN)
if (self->connector) break;
{ if (errno == EINTR)
connector_free (self->connector); continue;
free (self->connector);
self->connector = NULL; SOCKS_FAIL ("%s: %s", "send", strerror (errno));
return false;
} }
return true;
// At the lowest level we iterate over all addresses for the SOCKS server;
// this is done automatically by the connector
// Then we iterate over available protocols
if (++self->protocol_iter != SOCKS_MAX)
{
socks_connector_start (self);
return;
}
// At the highest level we iterate over possible targets
self->protocol_iter = 0;
if (self->targets_iter && (self->targets_iter = self->targets_iter->next))
{
socks_connector_start (self);
return;
}
// FIXME: we need to cancel all events
self->on_failure (self->user_data);
} }
static void static void
@ -917,7 +939,7 @@ socks_connector_on_ready
{ {
(void) pfd; (void) pfd;
if (self->on_data (self) && socks_try_flush_write_buffer (self)) if (socks_call_on_data (self) && socks_try_flush_write_buffer (self))
{ {
poller_fd_set (&self->socket_event, poller_fd_set (&self->socket_event,
self->write_buffer.len ? (POLLIN | POLLOUT) : POLLIN); self->write_buffer.len ? (POLLIN | POLLOUT) : POLLIN);
@ -935,16 +957,6 @@ socks_connector_on_ready
socks_connector_step (self); socks_connector_step (self);
} }
static void
socks_connector_on_timeout (struct socks_connector *self)
{
if (self->on_error)
self->on_error (self->user_data, "timeout");
// FIXME: we need to cancel all events
self->on_failure (self->user_data);
}
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
static void static void