/** * finish the non-blocking connect() * * sets 'errno' as if connect() would have failed * */ network_socket_retval_t network_socket_connect_finish(network_socket *sock) { int so_error = 0; network_socklen_t so_error_len = sizeof(so_error); /** * we might get called a 2nd time after a connect() == EINPROGRESS */ if (getsockopt(sock->fd, SOL_SOCKET, SO_ERROR, &so_error, &so_error_len)) { /* getsockopt failed */ g_critical("%s: getsockopt(%s) failed: %s (%d)", G_STRLOC, sock->dst->name->str, g_strerror(errno), errno); return NETWORK_SOCKET_ERROR; } switch (so_error) { case 0: network_socket_connect_setopts(sock); return NETWORK_SOCKET_SUCCESS; default: errno = so_error; return NETWORK_SOCKET_ERROR_RETRY; } }
/** * connect a socket * * the sock->addr has to be set before * * @param sock a socket * @return NETWORK_SOCKET_SUCCESS on connected, NETWORK_SOCKET_ERROR on error, NETWORK_SOCKET_ERROR_RETRY for try again * @see network_address_set_address() */ network_socket_retval_t network_socket_connect(network_socket *sock) { g_return_val_if_fail(sock->dst, NETWORK_SOCKET_ERROR); /* our _new() allocated it already */ g_return_val_if_fail(sock->dst->name->len, NETWORK_SOCKET_ERROR); /* we want to use the ->name in the error-msgs */ g_return_val_if_fail(sock->fd < 0, NETWORK_SOCKET_ERROR); /* we already have a valid fd, we don't want to leak it */ g_return_val_if_fail(sock->socket_type == SOCK_STREAM, NETWORK_SOCKET_ERROR); /** * create a socket for the requested address * * if the dst->addr isn't set yet, socket() will fail with unsupported type */ if (-1 == (sock->fd = socket(sock->dst->addr.common.sa_family, sock->socket_type, 0))) { g_critical("%s.%d: socket(%s) failed: %s (%d)", __FILE__, __LINE__, sock->dst->name->str, g_strerror(errno), errno); return NETWORK_SOCKET_ERROR; } /** * make the connect() call non-blocking * */ network_socket_set_non_blocking(sock); if (-1 == connect(sock->fd, &sock->dst->addr.common, sock->dst->len)) { /** * in most TCP cases we connect() will return with * EINPROGRESS ... 3-way handshake */ switch (errno) { case E_NET_INPROGRESS: case E_NET_WOULDBLOCK: return NETWORK_SOCKET_ERROR_RETRY; default: g_critical("%s.%d: connect(%s) failed: %s (%d)", __FILE__, __LINE__, sock->dst->name->str, g_strerror(errno), errno); return NETWORK_SOCKET_ERROR; } } network_socket_connect_setopts(sock); return NETWORK_SOCKET_SUCCESS; }
network_socket *self_connect(network_mysqld_con *con, network_backend_t *backend, GHashTable *pwd_table) { /*make sure that the max conn for the backend is no more than the config number *when max_conn_for_a_backend is no more than 0, there is no limitation for max connection for a backend; * */ if (con->srv->max_conn_for_a_backend > 0 && backend->connected_clients >= con->srv->max_conn_for_a_backend) { g_critical("%s.%d: self_connect:%08x's connected_clients is %d, which are too many!",__FILE__, __LINE__, backend, backend->connected_clients); return NULL; } //1. connect DB network_socket *sock = network_socket_new(); network_address_copy(sock->dst, backend->addr); if (-1 == (sock->fd = socket(sock->dst->addr.common.sa_family, sock->socket_type, 0))) { g_critical("%s.%d: socket(%s) failed: %s (%d)", __FILE__, __LINE__, sock->dst->name->str, g_strerror(errno), errno); network_socket_free(sock); return NULL; } if (-1 == (connect(sock->fd, &sock->dst->addr.common, sock->dst->len))) { g_message("%s.%d: connecting to backend (%s) failed, marking it as down for ...", __FILE__, __LINE__, sock->dst->name->str); network_socket_free(sock); if (backend->state != BACKEND_STATE_OFFLINE) backend->state = BACKEND_STATE_DOWN; return NULL; } //2. read handshake,重点是获取20个字节的随机串 off_t to_read = NET_HEADER_SIZE; guint offset = 0; guchar header[NET_HEADER_SIZE]; while (to_read > 0) { gssize len = recv(sock->fd, header + offset, to_read, 0); if (len == -1 || len == 0) { network_socket_free(sock); return NULL; } offset += len; to_read -= len; } to_read = header[0] + (header[1] << 8) + (header[2] << 16); offset = 0; GString *data = g_string_sized_new(to_read); while (to_read > 0) { gssize len = recv(sock->fd, data->str + offset, to_read, 0); if (len == -1 || len == 0) { network_socket_free(sock); g_string_free(data, TRUE); return NULL; } offset += len; to_read -= len; } data->len = offset; network_packet packet; packet.data = data; packet.offset = 0; network_mysqld_auth_challenge *challenge = network_mysqld_auth_challenge_new(); network_mysqld_proto_get_auth_challenge(&packet, challenge); //3. 生成response GString *response = g_string_sized_new(20); GString *hashed_password = g_hash_table_lookup(pwd_table, con->client->response->username->str); if (hashed_password) { network_mysqld_proto_password_scramble(response, S(challenge->challenge), S(hashed_password)); } else { network_socket_free(sock); g_string_free(data, TRUE); network_mysqld_auth_challenge_free(challenge); g_string_free(response, TRUE); return NULL; } //4. send auth off_t to_write = 58 + con->client->response->username->len; offset = 0; g_string_truncate(data, 0); char tmp[] = {to_write - 4, 0, 0, 1, 0x85, 0xa6, 3, 0, 0, 0, 0, 1, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}; g_string_append_len(data, tmp, 36); g_string_append_len(data, con->client->response->username->str, con->client->response->username->len); g_string_append_len(data, "\0\x14", 2); g_string_append_len(data, response->str, 20); g_string_free(response, TRUE); while (to_write > 0) { gssize len = send(sock->fd, data->str + offset, to_write, 0); if (len == -1) { network_socket_free(sock); g_string_free(data, TRUE); network_mysqld_auth_challenge_free(challenge); return NULL; } offset += len; to_write -= len; } //5. read auth result to_read = NET_HEADER_SIZE; offset = 0; while (to_read > 0) { gssize len = recv(sock->fd, header + offset, to_read, 0); if (len == -1 || len == 0) { network_socket_free(sock); g_string_free(data, TRUE); network_mysqld_auth_challenge_free(challenge); return NULL; } offset += len; to_read -= len; } to_read = header[0] + (header[1] << 8) + (header[2] << 16); offset = 0; g_string_truncate(data, 0); g_string_set_size(data, to_read); while (to_read > 0) { gssize len = recv(sock->fd, data->str + offset, to_read, 0); if (len == -1 || len == 0) { network_socket_free(sock); g_string_free(data, TRUE); network_mysqld_auth_challenge_free(challenge); return NULL; } offset += len; to_read -= len; } data->len = offset; if (data->str[0] != MYSQLD_PACKET_OK) { network_socket_free(sock); g_string_free(data, TRUE); network_mysqld_auth_challenge_free(challenge); return NULL; } g_string_free(data, TRUE); //6. set non-block network_socket_set_non_blocking(sock); network_socket_connect_setopts(sock); //此句是否需要?是否应该放在第1步末尾? sock->challenge = challenge; sock->response = network_mysqld_auth_response_copy(con->client->response); g_atomic_int_inc(&backend->connected_clients); return sock; }