xcom_transport.h

Go to the documentation of this file.

/* Copyright (c) 2015, 2023, Oracle and/or its affiliates.
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.
 
   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.
 
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License, version 2.0, for more details.
 
   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */
 
#ifndef XCOM_TRANSPORT_H
#define XCOM_TRANSPORT_H
 
#include "xcom/server_struct.h"
#include "xcom/site_struct.h"
#include "xcom/xcom_common.h"
#include "xdr_gen/xcom_vp.h"
 
#define XDR_INT_SIZE 4
#define MSG_HDR_SIZE (3 * XDR_INT_SIZE)
 
/* Definition of message with fixed size header and variable size payload */
 
/* This is version 1_0 of the header. It is OK to change the header in
   other versions as long as the version field is the first field.
*/
/* version[4] length[4] type[1] tag[2] UNUSED[1] message-body[length] */
/*
  The version is used both for protocol negotiations and to discard messages
  with wrong version.
  The length field is the length of the message, not including the header
  itself.
  The type field is 0 if a normal message, otherwise it is a protocol control
  message.
  The tag field will be used during protocol negotiation to uniquely identify
  the request. The reply will
  contain the same tag.
  The message-body contains xdr-serialized data.
 */
 
#define SERIALIZED_BUFLEN(x) ((x) + MSG_HDR_SIZE)
 
#define VERS_PTR(buf) (buf)
#define LENGTH_PTR(buf) &((buf)[XDR_INT_SIZE])
#define X_TYPE (2 * XDR_INT_SIZE)
#define X_TAG (X_TYPE + 1)
#define X_TAG_PTR(buf) &((buf)[X_TAG])
#ifdef NOTDEF
#define CHECK_PTR(buf) &((buf)[3 * XDR_INT_SIZE])
#endif
#define MSG_PTR(buf) &((buf)[MSG_HDR_SIZE])
 
extern xcom_proto const my_min_xcom_version; /* The minimum protocol version I
                                                am able to understand */
extern xcom_proto const
    my_xcom_version; /* The maximum protocol version I am able to understand */
 
/* Transport level message types */
enum x_msg_type {
  x_normal = 0,       /* Normal message */
  x_version_req = 1,  /* Negotiate protocol version */
  x_version_reply = 2 /* Protocol version reply */
};
typedef enum x_msg_type x_msg_type;
 
struct envelope {
  char *srv;
  xcom_port port;
  pax_msg *p;
  int crash_on_error;
};
 
typedef struct envelope envelope;
 
int check_protoversion(xcom_proto x_proto, xcom_proto negotiated);
int flush_srv_buf(server *s, int64_t *ret);
 
/**
  Reads message from connection rfd with buffering reads.
 
  @param[in]     rfd Pointer to open connection.
  @param[in,out] buf Used for buffering reads.
  @param[out]    p   Output buffer.
  @param[out]    s   Pointer to server. Server timestamp updated if not 0.
  @param[out]    ret Number of bytes read, or -1 if failure.
 
  @retval 0 if task should terminate.
  @retval 1 if it should continue.
*/
 
int buffered_read_msg(connection_descriptor *rfd, srv_buf *buf, pax_msg *p,
                      server *s, int64_t *ret);
 
/**
  Reads message from connection rfd without buffering reads.
 
  @param[in]     rfd Pointer to open connection.
  @param[out]    p   Output buffer.
  @param[in,out] s   Pointer to server. Server timestamp updated if not 0.
  @param[in,out] ret Number of bytes read, or -1 if failure.
 
  @retval 0 if task should terminate.
  @retval 1 if it should continue.
*/
int read_msg(connection_descriptor *rfd, pax_msg *p, server *s, int64_t *ret);
 
int send_to_acceptors(pax_msg *p, const char *dbg);
int send_to_all(pax_msg *p, const char *dbg);
int send_to_all_site(site_def const *s, pax_msg *p, const char *dbg);
int send_to_others(site_def const *s, pax_msg *p, const char *dbg);
int send_to_someone(site_def const *s, pax_msg *p, const char *dbg);
int send_to_self_site(site_def const *s, pax_msg *p);
int send_to_all_except_self(site_def const *s, pax_msg *p, const char *dbg);
 
void wakeup_sender();
int sender_task(task_arg arg);
int local_sender_task(task_arg arg);
int shutdown_servers();
int srv_ref(server *s);
int srv_unref(server *s);
int tcp_reaper_task(task_arg arg);
int tcp_reconnection_task(task_arg arg);
int incoming_connection_task(task_arg arg);
uint32_t crc32c_hash(char *buf, char *end);
int apply_xdr(void *buff, uint32_t bufflen, xdrproc_t xdrfunc, void *xdrdata,
              enum xdr_op op);
void init_crc32c();
void init_xcom_transport(xcom_port listen_port);
void reset_srv_buf(srv_buf *sb);
char *xcom_get_name(char *a);
xcom_port xcom_get_port(char *a);
int send_server_msg(site_def const *s, node_no i, pax_msg *p);
double server_active(site_def const *s, node_no i);
void update_servers(site_def *s, cargo_type operation);
void garbage_collect_servers();
int send_msg(server *s, node_no from, node_no to, uint32_t group_id,
             pax_msg *p);
/**
  Updates timestamp of server.
 
  @param[in]     s  Pointer to server.
*/
void server_detected(server *s);
 
void invalidate_servers(const site_def *old_site_def,
                        const site_def *new_site_def);
 
void shutdown_connection(connection_descriptor *con);
void reset_connection(connection_descriptor *con);
void close_connection(connection_descriptor *con);
 
int close_open_connection(connection_descriptor *conn);
connection_descriptor *open_new_connection(
    const char *server, xcom_port port,
    int connection_timeout = Network_provider::default_connection_timeout());
connection_descriptor *open_new_local_connection(const char *server,
                                                 xcom_port port);
 
#ifndef XCOM_WITHOUT_OPENSSL
void ssl_free_con(connection_descriptor *con);
#endif
 
char const *xcom_proto_name(xcom_proto proto_vers);
xcom_proto negotiate_protocol(xcom_proto proto_vers);
void get_header_1_0(unsigned char header_buf[], uint32_t *msgsize,
                    x_msg_type *x_type, unsigned int *tag);
void put_header_1_0(unsigned char header_buf[], uint32_t msgsize,
                    x_msg_type x_type, unsigned int tag);
 
int send_proto(connection_descriptor *con, xcom_proto x_proto,
               x_msg_type x_type, unsigned int tag, int64_t *ret);
int recv_proto(connection_descriptor const *rfd, xcom_proto *x_proto,
               x_msg_type *x_type, unsigned int *tag, int64_t *ret);
 
void write_protoversion(unsigned char *buf, xcom_proto proto_vers);
xcom_proto read_protoversion(unsigned char *p);
 
int serialize_msg(pax_msg *p, xcom_proto x_proto, uint32_t *buflen, char **buf);
int deserialize_msg(pax_msg *p, xcom_proto x_proto, char *buf, uint32_t buflen);
xcom_proto common_xcom_version(site_def const *site);
xcom_proto get_latest_common_proto();
xcom_proto set_latest_common_proto(xcom_proto x_proto);
extern linkage connect_wait;
extern int connect_tcp(char *server, xcom_port port, int *ret);
 
/**
 * @brief Returns the version from which nodes are able to speak IPv6
 *
 * @return xcom_proto the version from which nodes are able to speak IPv6
 */
xcom_proto minimum_ipv6_version();
 
#define IP_MAX_SIZE 512
 
/**
 * @brief Get the ip and port object from a given address in the authorized
 * input format. For IP v4 is IP (or) NAME:PORT and for IPv6 is [IP (or)
 * NAME]:PORT
 *
 * @param address input address to parse
 * @param ip the resulting IP or Name
 * @param port the resulting port
 * @return int true (1) in case of parse error
 */
int get_ip_and_port(char const *address, char ip[IP_MAX_SIZE], xcom_port *port);
 
/**
 * @brief Checks if an incoming node is eligible to enter the group
 *
 * This function checks if a new node entering the group is able to be part of
 * it.
 * This is needed duw to downgrade procedures to server versions that do not
 * speak IPv6. One will check if:
 * - Our server is being contacted by a server that has a lower version than the
 * IPv6 baseline
 * - Check if the current configuration is all reachable by an IPv4 node
 *
 * If all of the above hold true we are able to proceed and add the node. Else,
 * we must fail.
 *
 * @retval 1 in case of success.
 */
int is_new_node_eligible_for_ipv6(xcom_proto incoming_proto,
                                  const site_def *current_site_def);
 
#define INITIAL_CONNECT_WAIT 0.1
#define MAX_CONNECT_WAIT 10.0
#define CONNECT_WAIT_INCREASE 1.0
 
#endif