diff options
Diffstat (limited to 'common.c')
| -rw-r--r-- | common.c | 825 |
1 files changed, 569 insertions, 256 deletions
@@ -229,7 +229,7 @@ connector_step (struct connector *self) self->on_connected (self->user_data, fd); return; } - else if (errno != EINPROGRESS) + if (errno != EINPROGRESS) { connector_notify_error (self, strerror (errno)); xclose (fd); @@ -324,15 +324,14 @@ connector_add_target (struct connector *self, return true; } -// --- SOCKS 5/4a (blocking implementation) ------------------------------------ +// --- SOCKS 5/4a -------------------------------------------------------------- -// These are awkward protocols. 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. In the latter version, it forms a pair with the -// password field and doesn't need to be an actual user on your machine. +// Asynchronous SOCKS connector. Adds more stuff on top of the original. -// TODO: make a non-blocking poller-based version of this; -// either use c-ares or (even better) start another thread to do resolution +// 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. +// In the latter version, it forms a pair with the password field and doesn't +// need to be an actual user on your machine. struct socks_addr { @@ -346,388 +345,702 @@ struct socks_addr union { uint8_t ipv4[4]; ///< IPv4 address, network octet order - const char *domain; ///< Domain name + char *domain; ///< Domain name uint8_t ipv6[16]; ///< IPv6 address, network octet order } data; ///< The address itself }; -struct socks_data +static void +socks_addr_free (struct socks_addr *self) +{ + if (self->type == SOCKS_DOMAIN) + free (self->data.domain); +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +struct socks_target { + LIST_HEADER (struct socks_target) + struct socks_addr address; ///< Target address - uint16_t port; ///< Target port - const char *username; ///< Authentication username - const char *password; ///< Authentication password + uint16_t port; ///< Target service port +}; + +enum socks_protocol +{ + SOCKS_5, ///< SOCKS5 + SOCKS_4A, ///< SOCKS4A + SOCKS_MAX ///< End of protocol +}; + +struct socks_connector +{ + struct connector *connector; ///< Proxy server iterator (effectively) + enum socks_protocol protocol_iter; ///< Protocol iterator + struct socks_target *targets_iter; ///< Targets iterator + + // Negotiation: + + int socket_fd; ///< Current socket file descriptor + struct poller_fd socket_event; ///< Socket can be read from/written to + struct str read_buffer; ///< Read buffer + struct str write_buffer; ///< Write buffer + struct poller_timer timeout; ///< Timeout timer + + uint8_t bound_address_len; ///< Length of domain name struct socks_addr bound_address; ///< Bound address at the server uint16_t bound_port; ///< Bound port at the server + + /// Process incoming data if there's enough of it available + bool (*on_data) (struct socks_connector *); + + // Configuration: + + const char *hostname; ///< SOCKS server hostname + const char *service; ///< SOCKS server service name or port + + const char *username; ///< Username for authentication + const char *password; ///< Password for authentication + + struct socks_target *targets; ///< Targets + struct socks_target *targets_tail; ///< Tail of targets + + void *user_data; ///< User data for callbacks + + // You may destroy the connector object in these two main callbacks: + + /// Connection has been successfully established + void (*on_connected) (void *user_data, int socket); + /// Failed to establish a connection to either target + void (*on_failure) (void *user_data); + + // Optional: + + /// Connecting to a new address + void (*on_connecting) (void *user_data, + const char *address, const char *via, const char *version); + /// Connecting to the last address has failed + void (*on_error) (void *user_data, const char *error); }; +#define SOCKS_FAIL(...) \ + BLOCK_START \ + char *error = xstrdup_printf (__VA_ARGS__); \ + if (self->on_error) \ + self->on_error (self->user_data, error); \ + free (error); \ + return false; \ + BLOCK_END + +// FIXME: we need to cancel all events +#define SOCKS_DONE() \ + BLOCK_START \ + int fd = self->socket_fd; \ + set_blocking (fd, true); \ + self->socket_fd = -1; \ + self->on_connected (self->user_data, fd); \ + return true; \ + BLOCK_END + +#define SOCKS_NEED_DATA(n) \ + if (!socks_try_fill_read_buffer (self, (n))) \ + return false; \ + if (self->read_buffer.len < n) \ + return true + +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_get_socket (struct addrinfo *addresses, int *fd, struct error **e) +socks_try_flush_write_buffer (struct socks_connector *self) { - int sockfd; - for (; addresses; addresses = addresses->ai_next) + struct str *wb = &self->write_buffer; + ssize_t n_written; + + while (wb->len) { - sockfd = socket (addresses->ai_family, - addresses->ai_socktype, addresses->ai_protocol); - if (sockfd == -1) + n_written = send (self->socket_fd, wb->str, wb->len, 0); + if (n_written >= 0) + { + str_remove_slice (wb, 0, n_written); continue; - set_cloexec (sockfd); - - int yes = 1; - soft_assert (setsockopt (sockfd, SOL_SOCKET, SO_KEEPALIVE, - &yes, sizeof yes) != -1); + } - if (!connect (sockfd, addresses->ai_addr, addresses->ai_addrlen)) + if (errno == EAGAIN) break; - xclose (sockfd); - } - if (!addresses) - { - error_set (e, "couldn't connect to the SOCKS server"); + if (errno == EINTR) + continue; + + SOCKS_FAIL ("%s: %s", "send", strerror (errno)); return false; } - *fd = sockfd; return true; } -#define SOCKS_FAIL(...) \ - BLOCK_START \ - error_set (e, __VA_ARGS__); \ - goto fail; \ - BLOCK_END -#define SOCKS_RECV(buf, len) \ - BLOCK_START \ - if ((n = recv (sockfd, (buf), (len), 0)) == -1) \ - SOCKS_FAIL ("%s: %s", "recv", strerror (errno)); \ - if (n != (len)) \ - SOCKS_FAIL ("%s: %s", "protocol error", "unexpected EOF"); \ - BLOCK_END +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - static bool -socks_4a_connect (struct addrinfo *addresses, struct socks_data *data, - int *fd, struct error **e) +socks_4a_finish (struct socks_connector *self) { - int sockfd; - if (!socks_get_socket (addresses, &sockfd, e)) - return false; + SOCKS_NEED_DATA (8); + + struct msg_unpacker unpacker; + msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len); + + uint8_t null, status; + hard_assert (msg_unpacker_u8 (&unpacker, &null)); + hard_assert (msg_unpacker_u8 (&unpacker, &status)); + str_remove_slice (&self->read_buffer, 0, unpacker.offset); + + if (null != 0) + SOCKS_FAIL ("protocol error"); + + switch (status) + { + case 90: + SOCKS_DONE (); + case 91: + SOCKS_FAIL ("request rejected or failed"); + case 92: + SOCKS_FAIL ("%s: %s", "request rejected", + "SOCKS server cannot connect to identd on the client"); + case 93: + SOCKS_FAIL ("%s: %s", "request rejected", + "identd reports different user-id"); + default: + SOCKS_FAIL ("protocol error"); + } +} +static bool +socks_4a_start (struct socks_connector *self) +{ + struct socks_target *target = self->targets_iter; const void *dest_ipv4 = "\x00\x00\x00\x01"; const char *dest_domain = NULL; char buf[INET6_ADDRSTRLEN]; - switch (data->address.type) + switch (target->address.type) { case SOCKS_IPV4: - dest_ipv4 = data->address.data.ipv4; + dest_ipv4 = target->address.data.ipv4; break; case SOCKS_IPV6: // About the best thing we can do, not sure if it works anywhere at all - if (!inet_ntop (AF_INET6, &data->address.data.ipv6, buf, sizeof buf)) + if (!inet_ntop (AF_INET6, &target->address.data.ipv6, buf, sizeof buf)) SOCKS_FAIL ("%s: %s", "inet_ntop", strerror (errno)); dest_domain = buf; break; case SOCKS_DOMAIN: - dest_domain = data->address.data.domain; + dest_domain = target->address.data.domain; } - struct str req; - str_init (&req); - str_append_c (&req, 4); // version - str_append_c (&req, 1); // connect + struct str *wb = &self->write_buffer; + str_init (wb); + str_append_c (wb, 4); // version + str_append_c (wb, 1); // connect - str_append_c (&req, data->port >> 8); // higher bits of port - str_append_c (&req, data->port); // lower bits of port - str_append_data (&req, dest_ipv4, 4); // destination address + str_append_c (wb, target->port >> 8); // higher bits of port + str_append_c (wb, target->port); // lower bits of port + str_append_data (wb, dest_ipv4, 4); // destination address - if (data->username) - str_append (&req, data->username); - str_append_c (&req, '\0'); + if (self->username) + str_append (wb, self->username); + str_append_c (wb, '\0'); if (dest_domain) { - str_append (&req, dest_domain); - str_append_c (&req, '\0'); + str_append (wb, dest_domain); + str_append_c (wb, '\0'); } - ssize_t n = send (sockfd, req.str, req.len, 0); - str_free (&req); - if (n == -1) - SOCKS_FAIL ("%s: %s", "send", strerror (errno)); + self->on_data = socks_4a_finish; + return true; +} - uint8_t resp[8]; - SOCKS_RECV (resp, sizeof resp); - if (resp[0] != 0) - SOCKS_FAIL ("protocol error"); +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - switch (resp[1]) - { - case 90: - break; - case 91: - SOCKS_FAIL ("request rejected or failed"); - case 92: - SOCKS_FAIL ("%s: %s", "request rejected", - "SOCKS server cannot connect to identd on the client"); - case 93: - SOCKS_FAIL ("%s: %s", "request rejected", - "identd reports different user-id"); - default: - SOCKS_FAIL ("protocol error"); - } +static bool +socks_5_request_port (struct socks_connector *self) +{ + SOCKS_NEED_DATA (2); - *fd = sockfd; - return true; + struct msg_unpacker unpacker; + msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len); + hard_assert (msg_unpacker_u16 (&unpacker, &self->bound_port)); + str_remove_slice (&self->read_buffer, 0, unpacker.offset); -fail: - xclose (sockfd); - return false; + SOCKS_DONE (); } -#undef SOCKS_FAIL -#define SOCKS_FAIL(...) \ - BLOCK_START \ - error_set (e, __VA_ARGS__); \ - return false; \ - BLOCK_END +static bool +socks_5_request_ipv4 (struct socks_connector *self) +{ + size_t len = sizeof self->bound_address.data.ipv4; + SOCKS_NEED_DATA (len); + 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; + return true; +} static bool -socks_5_userpass_auth (int sockfd, struct socks_data *data, struct error **e) +socks_5_request_ipv6 (struct socks_connector *self) { - size_t ulen = strlen (data->username); - if (ulen > 255) - ulen = 255; + size_t len = sizeof self->bound_address.data.ipv6; + SOCKS_NEED_DATA (len); + memcpy (self->bound_address.data.ipv6, self->read_buffer.str, len); + str_remove_slice (&self->read_buffer, 0, len); - size_t plen = strlen (data->password); - if (plen > 255) - plen = 255; + self->on_data = socks_5_request_port; + return true; +} - uint8_t req[3 + ulen + plen], *p = req; - *p++ = 0x01; // version - *p++ = ulen; // username length - memcpy (p, data->username, ulen); - p += ulen; - *p++ = plen; // password length - memcpy (p, data->password, plen); - p += plen; - - ssize_t n = send (sockfd, req, p - req, 0); - if (n == -1) - SOCKS_FAIL ("%s: %s", "send", strerror (errno)); +static bool +socks_5_request_domain_data (struct socks_connector *self) +{ + size_t len = self->bound_address_len; + SOCKS_NEED_DATA (len); + self->bound_address.data.domain = xstrndup (self->read_buffer.str, len); + str_remove_slice (&self->read_buffer, 0, len); - uint8_t resp[2]; - SOCKS_RECV (resp, sizeof resp); - if (resp[0] != 0x01) - SOCKS_FAIL ("protocol error"); - if (resp[1] != 0x00) - SOCKS_FAIL ("authentication failure"); + self->on_data = socks_5_request_port; return true; } static bool -socks_5_auth (int sockfd, struct socks_data *data, struct error **e) +socks_5_request_domain (struct socks_connector *self) { - bool can_auth = data->username && data->password; + SOCKS_NEED_DATA (1); - uint8_t hello[4]; - hello[0] = 0x05; // version - hello[1] = 1 + can_auth; // number of authentication methods - hello[2] = 0x00; // no authentication required - hello[3] = 0x02; // username/password + struct msg_unpacker unpacker; + msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len); + hard_assert (msg_unpacker_u8 (&unpacker, &self->bound_address_len)); + str_remove_slice (&self->read_buffer, 0, unpacker.offset); - ssize_t n = send (sockfd, hello, 3 + can_auth, 0); - if (n == -1) - SOCKS_FAIL ("%s: %s", "send", strerror (errno)); + self->on_data = socks_5_request_domain_data; + return true; +} - uint8_t resp[2]; - SOCKS_RECV (resp, sizeof resp); - if (resp[0] != 0x05) +static bool +socks_5_request_finish (struct socks_connector *self) +{ + SOCKS_NEED_DATA (4); + + struct msg_unpacker unpacker; + msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len); + + uint8_t version, status, reserved, type; + hard_assert (msg_unpacker_u8 (&unpacker, &version)); + hard_assert (msg_unpacker_u8 (&unpacker, &status)); + hard_assert (msg_unpacker_u8 (&unpacker, &reserved)); + hard_assert (msg_unpacker_u8 (&unpacker, &type)); + str_remove_slice (&self->read_buffer, 0, unpacker.offset); + + if (version != 0x05) SOCKS_FAIL ("protocol error"); - switch (resp[1]) + switch (status) { - case 0x02: - if (!can_auth) - SOCKS_FAIL ("protocol error"); - if (!socks_5_userpass_auth (sockfd, data, e)) - return false; case 0x00: break; - case 0xFF: - SOCKS_FAIL ("no acceptable authentication methods"); - default: - SOCKS_FAIL ("protocol error"); + case 0x01: SOCKS_FAIL ("general SOCKS server failure"); + case 0x02: SOCKS_FAIL ("connection not allowed by ruleset"); + case 0x03: SOCKS_FAIL ("network unreachable"); + case 0x04: SOCKS_FAIL ("host unreachable"); + case 0x05: SOCKS_FAIL ("connection refused"); + case 0x06: SOCKS_FAIL ("TTL expired"); + case 0x07: SOCKS_FAIL ("command not supported"); + case 0x08: SOCKS_FAIL ("address type not supported"); + default: SOCKS_FAIL ("protocol error"); + } + + switch ((self->bound_address.type = type)) + { + case SOCKS_IPV4: self->on_data = socks_5_request_ipv4; return true; + case SOCKS_IPV6: self->on_data = socks_5_request_ipv6; return true; + case SOCKS_DOMAIN: self->on_data = socks_5_request_domain; return true; + default: SOCKS_FAIL ("protocol error"); } - return true; } static bool -socks_5_send_req (int sockfd, struct socks_data *data, struct error **e) +socks_5_request_start (struct socks_connector *self) { - uint8_t req[4 + 256 + 2], *p = req; - *p++ = 0x05; // version - *p++ = 0x01; // connect - *p++ = 0x00; // reserved - *p++ = data->address.type; + struct socks_target *target = self->targets_iter; + struct str *wb = &self->write_buffer; + str_append_c (wb, 0x05); // version + str_append_c (wb, 0x01); // connect + str_append_c (wb, 0x00); // reserved + str_append_c (wb, target->address.type); - switch (data->address.type) + switch (target->address.type) { case SOCKS_IPV4: - memcpy (p, data->address.data.ipv4, sizeof data->address.data.ipv4); - p += sizeof data->address.data.ipv4; + str_append_data (wb, + target->address.data.ipv4, sizeof target->address.data.ipv4); break; case SOCKS_DOMAIN: { - size_t dlen = strlen (data->address.data.domain); + size_t dlen = strlen (target->address.data.domain); if (dlen > 255) dlen = 255; - *p++ = dlen; - memcpy (p, data->address.data.domain, dlen); - p += dlen; + str_append_c (wb, dlen); + str_append_data (wb, target->address.data.domain, dlen); break; } case SOCKS_IPV6: - memcpy (p, data->address.data.ipv6, sizeof data->address.data.ipv6); - p += sizeof data->address.data.ipv6; + str_append_data (wb, + target->address.data.ipv6, sizeof target->address.data.ipv6); break; } - *p++ = data->port >> 8; - *p++ = data->port; + str_append_c (wb, target->port >> 8); + str_append_c (wb, target->port); - if (send (sockfd, req, p - req, 0) == -1) - SOCKS_FAIL ("%s: %s", "send", strerror (errno)); + self->on_data = socks_5_request_finish; + return true; +} + +static bool +socks_5_userpass_finish (struct socks_connector *self) +{ + SOCKS_NEED_DATA (2); + + struct msg_unpacker unpacker; + msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len); + + uint8_t version, status; + hard_assert (msg_unpacker_u8 (&unpacker, &version)); + hard_assert (msg_unpacker_u8 (&unpacker, &status)); + str_remove_slice (&self->read_buffer, 0, unpacker.offset); + + if (version != 0x01) + SOCKS_FAIL ("protocol error"); + if (status != 0x00) + SOCKS_FAIL ("authentication failure"); + return socks_5_request_start (self); +} + +static bool +socks_5_userpass_start (struct socks_connector *self) +{ + size_t ulen = strlen (self->username); + if (ulen > 255) + ulen = 255; + + size_t plen = strlen (self->password); + if (plen > 255) + plen = 255; + + struct str *wb = &self->write_buffer; + str_append_c (wb, 0x01); // version + str_append_c (wb, ulen); // username length + str_append_data (wb, self->username, ulen); + str_append_c (wb, plen); // password length + str_append_data (wb, self->password, plen); + + self->on_data = socks_5_userpass_finish; return true; } static bool -socks_5_process_resp (int sockfd, struct socks_data *data, struct error **e) +socks_5_auth_finish (struct socks_connector *self) { - uint8_t resp_header[4]; - ssize_t n; - SOCKS_RECV (resp_header, sizeof resp_header); - if (resp_header[0] != 0x05) + SOCKS_NEED_DATA (2); + + struct msg_unpacker unpacker; + msg_unpacker_init (&unpacker, self->read_buffer.str, self->read_buffer.len); + + uint8_t version, method; + hard_assert (msg_unpacker_u8 (&unpacker, &version)); + hard_assert (msg_unpacker_u8 (&unpacker, &method)); + str_remove_slice (&self->read_buffer, 0, unpacker.offset); + + if (version != 0x05) SOCKS_FAIL ("protocol error"); - switch (resp_header[1]) + bool can_auth = self->username && self->password; + + switch (method) { + case 0x02: + if (!can_auth) + SOCKS_FAIL ("protocol error"); + + return socks_5_userpass_start (self); case 0x00: - break; - case 0x01: SOCKS_FAIL ("general SOCKS server failure"); - case 0x02: SOCKS_FAIL ("connection not allowed by ruleset"); - case 0x03: SOCKS_FAIL ("network unreachable"); - case 0x04: SOCKS_FAIL ("host unreachable"); - case 0x05: SOCKS_FAIL ("connection refused"); - case 0x06: SOCKS_FAIL ("TTL expired"); - case 0x07: SOCKS_FAIL ("command not supported"); - case 0x08: SOCKS_FAIL ("address type not supported"); - default: SOCKS_FAIL ("protocol error"); + return socks_5_request_start (self); + case 0xFF: + SOCKS_FAIL ("no acceptable authentication methods"); + default: + SOCKS_FAIL ("protocol error"); } +} - switch ((data->bound_address.type = resp_header[3])) - { - case SOCKS_IPV4: - SOCKS_RECV (data->bound_address.data.ipv4, - sizeof data->bound_address.data.ipv4); - break; - case SOCKS_IPV6: - SOCKS_RECV (data->bound_address.data.ipv6, - sizeof data->bound_address.data.ipv6); - break; - case SOCKS_DOMAIN: +static bool +socks_5_auth_start (struct socks_connector *self) +{ + bool can_auth = self->username && self->password; + + struct str *wb = &self->write_buffer; + str_append_c (wb, 0x05); // version + str_append_c (wb, 1 + can_auth); // number of authentication methods + str_append_c (wb, 0x00); // no authentication required + str_append_c (wb, 0x02); // username/password + + self->on_data = socks_5_auth_finish; + return true; +} + +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +static void socks_connector_step (struct socks_connector *self); + +static void +socks_connector_on_connected (void *user_data, int socket_fd) +{ + set_blocking (socket_fd, false); + + struct socks_connector *self = user_data; + self->socket_fd = socket_fd; + self->socket_event.fd = socket_fd; + poller_fd_set (&self->socket_event, POLLIN | POLLOUT); + str_reset (&self->read_buffer); + str_reset (&self->write_buffer); + + if ((self->protocol_iter == SOCKS_5 && socks_5_auth_start (self)) + || (self->protocol_iter == SOCKS_4A && socks_4a_start (self))) + return; + + self->on_failure (self->user_data); +} + +static void +socks_connector_on_failure (void *user_data) +{ + struct socks_connector *self = user_data; + // TODO: skip SOCKS server on connection failure + socks_connector_step (self); +} + +static void +socks_connector_on_connecting (void *user_data, const char *via) +{ + struct socks_connector *self = user_data; + if (!self->on_connecting) + return; + + // TODO: reconstruct the address from the current target iterator, + // or just store it in unprocessed form + char *address = format_host_port_pair ("", ""); + self->on_connecting (self->user_data, address, via, + self->protocol_iter ? "SOCKS4A" : "SOCKS5"); + free (address); +} + +static void +socks_connector_on_error (void *user_data, const char *error) +{ + struct socks_connector *self = user_data; + // TODO: skip protocol on protocol failure + self->on_error (self->user_data, error); +} + +static void +socks_connector_start (struct socks_connector *self) +{ + struct connector *connector = + self->connector = xcalloc (1, sizeof *connector); + connector_init (connector, self->socket_event.poller); + + connector->user_data = self; + connector->on_connected = socks_connector_on_connected; + connector->on_connecting = socks_connector_on_connecting; + connector->on_error = socks_connector_on_error; + connector->on_failure = socks_connector_on_failure; + + // TODO: let's rather call on_error and on_failure instead on error + hard_assert (connector_add_target (connector, + self->hostname, self->service, NULL)); + + connector_step (connector); + poller_timer_set (&self->timeout, 60 * 1000); +} + +static void +socks_connector_step (struct socks_connector *self) +{ + // Destroy current connector if needed + if (self->connector) { - uint8_t len; - SOCKS_RECV (&len, sizeof len); + connector_free (self->connector); + free (self->connector); + self->connector = NULL; + } - char domain[len + 1]; - SOCKS_RECV (domain, len); - domain[len] = '\0'; + // At the lowest level we iterate over all addresses for the SOCKS server; + // this is done automatically by the connector - data->bound_address.data.domain = xstrdup (domain); - break; + // Then we iterate over available protocols + if (++self->protocol_iter != SOCKS_MAX) + { + socks_connector_start (self); + return; } - default: - SOCKS_FAIL ("protocol error"); + + // 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; } - uint16_t port; - SOCKS_RECV (&port, sizeof port); - data->bound_port = ntohs (port); - return true; + // FIXME: we need to cancel all events + self->on_failure (self->user_data); } -#undef SOCKS_FAIL -#undef SOCKS_RECV - -static bool -socks_5_connect (struct addrinfo *addresses, struct socks_data *data, - int *fd, struct error **e) +static void +socks_connector_on_ready + (const struct pollfd *pfd, struct socks_connector *self) { - int sockfd; - if (!socks_get_socket (addresses, &sockfd, e)) - return false; + (void) pfd; - if (!socks_5_auth (sockfd, data, e) - || !socks_5_send_req (sockfd, data, e) - || !socks_5_process_resp (sockfd, data, e)) + if (!self->on_data (self) || !socks_try_flush_write_buffer (self)) { - xclose (sockfd); - return false; + // We've failed this target, let's try to move on + // FIXME: we need to cancel all events + socks_connector_step (self); + } + // If we successfully establish the connection, then the FD is reset to -1 + else if (self->socket_fd != -1) + { + poller_fd_set (&self->socket_event, + self->write_buffer.len ? (POLLIN | POLLOUT) : POLLIN); } +} - *fd = sockfd; - return true; +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 int -socks_connect (const char *socks_host, const char *socks_port, - const char *host, const char *port, - const char *username, const char *password, struct error **e) +// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - + +static void +socks_connector_init (struct socks_connector *self, struct poller *poller) { - int result = -1; - struct addrinfo gai_hints, *gai_result; - memset (&gai_hints, 0, sizeof gai_hints); - gai_hints.ai_socktype = SOCK_STREAM; + memset (self, 0, sizeof *self); - unsigned long port_no; - const struct servent *serv; - if ((serv = getservbyname (port, "tcp"))) - port_no = (uint16_t) ntohs (serv->s_port); - else if (!xstrtoul (&port_no, port, 10) || !port_no || port_no > UINT16_MAX) + poller_fd_init (&self->socket_event, poller, (self->socket_fd = -1)); + self->socket_event.dispatcher = (poller_fd_fn) socks_connector_on_ready; + self->socket_event.user_data = self; + + poller_timer_init (&self->timeout, poller); + self->timeout.dispatcher = (poller_timer_fn) socks_connector_on_timeout; + self->timeout.user_data = self; + + str_init (&self->read_buffer); + str_init (&self->write_buffer); +} + +static void +socks_connector_free (struct socks_connector *self) +{ + if (self->connector) { - error_set (e, "invalid port number"); - goto fail; + connector_free (self->connector); + free (self->connector); } - int err = getaddrinfo (socks_host, socks_port, &gai_hints, &gai_result); - if (err) + poller_fd_reset (&self->socket_event); + poller_timer_reset (&self->timeout); + + if (self->socket_fd != -1) + xclose (self->socket_fd); + + str_free (&self->read_buffer); + str_free (&self->write_buffer); + + LIST_FOR_EACH (struct socks_target, iter, self->targets) { - error_set (e, "%s: %s", "getaddrinfo", gai_strerror (err)); - goto fail; + socks_addr_free (&iter->address); + free (iter); } - struct socks_data data = - { .username = username, .password = password, .port = port_no }; + socks_addr_free (&self->bound_address); +} - if (inet_pton (AF_INET, host, &data.address.data.ipv4) == 1) - data.address.type = SOCKS_IPV4; - else if (inet_pton (AF_INET6, host, &data.address.data.ipv6) == 1) - data.address.type = SOCKS_IPV6; +static bool +socks_connector_add_target (struct socks_connector *self, + const char *host, const char *service, struct error **e) +{ + unsigned long port; + const struct servent *serv; + if ((serv = getservbyname (service, "tcp"))) + port = (uint16_t) ntohs (serv->s_port); + else if (!xstrtoul (&port, service, 10) || !port || port > UINT16_MAX) + { + error_set (e, "invalid port number"); + return false; + } + + struct socks_target *target = xcalloc (1, sizeof *target); + if (inet_pton (AF_INET, host, &target->address.data.ipv4) == 1) + target->address.type = SOCKS_IPV4; + else if (inet_pton (AF_INET6, host, &target->address.data.ipv6) == 1) + target->address.type = SOCKS_IPV6; else { - data.address.type = SOCKS_DOMAIN; - data.address.data.domain = host; + target->address.type = SOCKS_DOMAIN; + target->address.data.domain = xstrdup (host); } - if (!socks_5_connect (gai_result, &data, &result, NULL)) - socks_4a_connect (gai_result, &data, &result, e); + target->port = port; + LIST_APPEND_WITH_TAIL (self->targets, self->targets_tail, target); + return true; +} - if (data.bound_address.type == SOCKS_DOMAIN) - free ((char *) data.bound_address.data.domain); - freeaddrinfo (gai_result); -fail: - return result; +static void +socks_connector_run (struct socks_connector *self) +{ + // XXX: do we need some better error checking in here? + hard_assert (self->hostname); + hard_assert (self->targets); + + self->targets_iter = self->targets; + self->protocol_iter = 0; + socks_connector_start (self); } // --- CTCP decoding ----------------------------------------------------------- |