| /* |
| * include/types/connection.h |
| * This file describes the connection struct and associated constants. |
| * |
| * Copyright (C) 2000-2012 Willy Tarreau - w@1wt.eu |
| * |
| * This library is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation, version 2.1 |
| * exclusively. |
| * |
| * This library 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 |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with this library; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #ifndef _TYPES_CONNECTION_H |
| #define _TYPES_CONNECTION_H |
| |
| #include <stdlib.h> |
| #include <sys/socket.h> |
| |
| #include <common/config.h> |
| |
| #include <types/listener.h> |
| #include <types/protocol.h> |
| |
| /* referenced below */ |
| struct connection; |
| struct buffer; |
| struct pipe; |
| struct server; |
| struct proxy; |
| struct si_applet; |
| struct task; |
| |
| /* Polling flags that are manipulated by I/O callbacks and handshake callbacks |
| * indicate what they expect from a file descriptor at each layer. For each |
| * direction, we have 2 bits, one stating whether any suspected activity on the |
| * FD induce a call to the iocb, and another one indicating that the FD has |
| * already returned EAGAIN and that polling on it is essential before calling |
| * the iocb again : |
| * POL ENA state |
| * 0 0 STOPPED : any activity on this FD is ignored |
| * 0 1 ENABLED : any (suspected) activity may call the iocb |
| * 1 0 STOPPED : as above |
| * 1 1 POLLED : the FD is being polled for activity |
| * |
| * - Enabling an I/O event consists in ORing with 1. |
| * - Stopping an I/O event consists in ANDing with ~1. |
| * - Polling for an I/O event consists in ORing with ~3. |
| * |
| * The last computed state is remembered in CO_FL_CURR_* so that differential |
| * changes can be applied. After bits are applied, the POLL status bits are |
| * cleared so that it is possible to detect when an EAGAIN was encountered. For |
| * pollers that do not support speculative I/O, POLLED is the same as ENABLED |
| * and the POL flag can safely be ignored. However it makes a difference for |
| * the connection handler. |
| * |
| * The ENA flags are per-layer (one pair for SOCK, another one for DATA). |
| * The POL flags are only for the socket layer since they indicate that EAGAIN |
| * was encountered. Thus, the DATA layer uses its own ENA flag and the socket |
| * layer's POL flag. |
| * |
| * The bits are arranged so that it is possible to detect a change by performing |
| * only a left shift followed by a xor and applying a mask to the result. The |
| * principle is that depending on what we want to check (data polling changes or |
| * sock polling changes), we mask different bits. The bits are arranged this way : |
| * |
| * S(ock) - W(ait) - C(urr) - P(oll) - D(ata) |
| * |
| * SOCK changes are reported when (S != C) || (W != P) => (S:W) != (C:P) |
| * DATA changes are reported when (D != C) || (W != P) => (W:C) != (P:D) |
| * The R and W bits are split apart so that we never shift more than 2 bits at |
| * a time, allowing move+shift to be done as a single operation on x86. |
| */ |
| |
| /* flags for use in connection->flags */ |
| enum { |
| CO_FL_NONE = 0x00000000, /* Just for initialization purposes */ |
| |
| /* Do not change these values without updating conn_*_poll_changes() ! */ |
| CO_FL_DATA_RD_ENA = 0x00000001, /* receiving data is allowed */ |
| CO_FL_CURR_RD_POL = 0x00000002, /* receiving needs to poll first */ |
| CO_FL_CURR_RD_ENA = 0x00000004, /* receiving is currently allowed */ |
| CO_FL_WAIT_RD = 0x00000008, /* receiving needs to poll first */ |
| CO_FL_SOCK_RD_ENA = 0x00000010, /* receiving handshakes is allowed */ |
| CO_FL_DATA_WR_ENA = 0x00000020, /* sending data is desired */ |
| CO_FL_CURR_WR_POL = 0x00000040, /* sending needs to poll first */ |
| CO_FL_CURR_WR_ENA = 0x00000080, /* sending is currently desired */ |
| CO_FL_WAIT_WR = 0x00000100, /* sending needs to poll first */ |
| CO_FL_SOCK_WR_ENA = 0x00000200, /* sending handshakes is desired */ |
| |
| /* These flags are used by data layers to indicate they had to stop |
| * sending data because a buffer was empty (WAIT_DATA) or stop receiving |
| * data because a buffer was full (WAIT_ROOM). The connection handler |
| * clears them before first calling the I/O and data callbacks. |
| */ |
| CO_FL_WAIT_DATA = 0x00000400, /* data source is empty */ |
| CO_FL_WAIT_ROOM = 0x00000800, /* data sink is full */ |
| |
| /* These flags are used to report whether the from/to addresses are set or not */ |
| CO_FL_ADDR_FROM_SET = 0x00001000, /* addr.from is set */ |
| CO_FL_ADDR_TO_SET = 0x00002000, /* addr.to is set */ |
| |
| /* flags indicating what event type the data layer is interested in */ |
| CO_FL_INIT_DATA = 0x00004000, /* initialize the data layer before using it */ |
| CO_FL_WAKE_DATA = 0x00008000, /* wake-up data layer upon activity at the transport layer */ |
| |
| /* flags used to remember what shutdown have been performed/reported */ |
| CO_FL_DATA_RD_SH = 0x00010000, /* DATA layer was notified about shutr/read0 */ |
| CO_FL_DATA_WR_SH = 0x00020000, /* DATA layer asked for shutw */ |
| CO_FL_SOCK_RD_SH = 0x00040000, /* SOCK layer was notified about shutr/read0 */ |
| CO_FL_SOCK_WR_SH = 0x00080000, /* SOCK layer asked for shutw */ |
| |
| /* flags used to report connection status and errors */ |
| CO_FL_ERROR = 0x00100000, /* a fatal error was reported */ |
| CO_FL_CONNECTED = 0x00200000, /* the connection is now established */ |
| CO_FL_WAIT_L4_CONN = 0x00400000, /* waiting for L4 to be connected */ |
| CO_FL_WAIT_L6_CONN = 0x00800000, /* waiting for L6 to be connected (eg: SSL) */ |
| |
| /* synthesis of the flags above */ |
| CO_FL_CONN_STATE = 0x00FF0000, /* all shut/connected flags */ |
| |
| /*** All the flags below are used for connection handshakes. Any new |
| * handshake should be added after this point, and CO_FL_HANDSHAKE |
| * should be updated. |
| */ |
| CO_FL_SI_SEND_PROXY = 0x01000000, /* send a valid PROXY protocol header */ |
| CO_FL_SSL_WAIT_HS = 0x02000000, /* wait for an SSL handshake to complete */ |
| CO_FL_ACCEPT_PROXY = 0x04000000, /* receive a valid PROXY protocol header */ |
| CO_FL_LOCAL_SPROXY = 0x08000000, /* send a valid local PROXY protocol header */ |
| |
| /* below we have all handshake flags grouped into one */ |
| CO_FL_HANDSHAKE = CO_FL_SI_SEND_PROXY | CO_FL_SSL_WAIT_HS | CO_FL_ACCEPT_PROXY | CO_FL_LOCAL_SPROXY, |
| |
| /* when any of these flags is set, polling is defined by socket-layer |
| * operations, as opposed to data-layer. Transport is explicitly not |
| * mentionned here to avoid any confusion, since it can be the same |
| * as DATA or SOCK on some implementations. |
| */ |
| CO_FL_POLL_SOCK = CO_FL_HANDSHAKE | CO_FL_WAIT_L4_CONN | CO_FL_WAIT_L6_CONN, |
| |
| /* This last flag indicates that the transport layer is used (for instance |
| * by logs) and must not be cleared yet. The last call to conn_xprt_close() |
| * must be done after clearing this flag. |
| */ |
| CO_FL_XPRT_TRACKED = 0x80000000, |
| }; |
| |
| /* target types */ |
| enum { |
| TARG_TYPE_NONE = 0, /* no target set, pointer is NULL by definition */ |
| TARG_TYPE_CLIENT, /* target is a client, pointer is NULL by definition */ |
| TARG_TYPE_PROXY, /* target is a proxy ; use address with the proxy's settings */ |
| TARG_TYPE_SERVER, /* target is a server ; use address with server's and its proxy's settings */ |
| TARG_TYPE_APPLET, /* target is an applet ; use only the applet */ |
| TARG_TYPE_TASK, /* target is a task running an external applet */ |
| }; |
| |
| |
| /* xprt_ops describes transport-layer operations for a connection. They |
| * generally run over a socket-based control layer, but not always. Some |
| * of them are used for data transfer with the upper layer (rcv_*, snd_*) |
| * and the other ones are used to setup and release the transport layer. |
| */ |
| struct xprt_ops { |
| int (*rcv_buf)(struct connection *conn, struct buffer *buf, int count); /* recv callback */ |
| int (*snd_buf)(struct connection *conn, struct buffer *buf, int flags); /* send callback */ |
| int (*rcv_pipe)(struct connection *conn, struct pipe *pipe, unsigned int count); /* recv-to-pipe callback */ |
| int (*snd_pipe)(struct connection *conn, struct pipe *pipe); /* send-to-pipe callback */ |
| void (*shutr)(struct connection *, int); /* shutr function */ |
| void (*shutw)(struct connection *, int); /* shutw function */ |
| void (*close)(struct connection *); /* close the transport layer */ |
| int (*init)(struct connection *conn); /* initialize the transport layer */ |
| }; |
| |
| /* data_cb describes the data layer's recv and send callbacks which are called |
| * when I/O activity was detected after the transport layer is ready. These |
| * callbacks are supposed to make use of the xprt_ops above to exchange data |
| * from/to buffers and pipes. The <wake> callback is used to report activity |
| * at the transport layer, which can be a connection opening/close, or any |
| * data movement. The <init> callback may be called by the connection handler |
| * at the end of a transport handshake, when it is about to transfer data and |
| * the data layer is not ready yet. Both <wake> and <init> may abort a connection |
| * by returning < 0. |
| */ |
| struct data_cb { |
| void (*recv)(struct connection *conn); /* data-layer recv callback */ |
| void (*send)(struct connection *conn); /* data-layer send callback */ |
| int (*wake)(struct connection *conn); /* data-layer callback to report activity */ |
| int (*init)(struct connection *conn); /* data-layer initialization */ |
| }; |
| |
| /* a target describes what is on the remote side of the connection. */ |
| struct target { |
| int type; |
| union { |
| void *v; /* pointer value, for any type */ |
| struct proxy *p; /* when type is TARG_TYPE_PROXY */ |
| struct server *s; /* when type is TARG_TYPE_SERVER */ |
| struct si_applet *a; /* when type is TARG_TYPE_APPLET */ |
| struct task *t; /* when type is TARG_TYPE_TASK */ |
| struct listener *l; /* when type is TARG_TYPE_CLIENT */ |
| } ptr; |
| } __attribute__((packed)); |
| |
| /* This structure describes a connection with its methods and data. |
| * A connection may be performed to proxy or server via a local or remote |
| * socket, and can also be made to an internal applet. It can support |
| * several transport schemes (applet, raw, ssl, ...). It can support several |
| * connection control schemes, generally a protocol for socket-oriented |
| * connections, but other methods for applets. |
| */ |
| struct connection { |
| const struct protocol *ctrl; /* operations at the socket layer */ |
| const struct xprt_ops *xprt; /* operations at the transport layer */ |
| const struct data_cb *data; /* data layer callbacks */ |
| unsigned int flags; /* CO_F_* */ |
| int xprt_st; /* transport layer state, initialized to zero */ |
| void *xprt_ctx; /* general purpose pointer, initialized to NULL */ |
| void *owner; /* pointer to upper layer's entity (eg: stream interface) */ |
| union { /* definitions which depend on connection type */ |
| struct { /*** information used by socket-based connections ***/ |
| int fd; /* file descriptor for a stream driver when known */ |
| } sock; |
| } t; |
| struct target target; /* the target to connect to (server, proxy, applet, ...) */ |
| struct { |
| struct sockaddr_storage from; /* client address, or address to spoof when connecting to the server */ |
| struct sockaddr_storage to; /* address reached by the client, or address to connect to */ |
| } addr; /* addresses of the remote side, client for producer and server for consumer */ |
| }; |
| |
| #endif /* _TYPES_CONNECTION_H */ |
| |
| /* |
| * Local variables: |
| * c-indent-level: 8 |
| * c-basic-offset: 8 |
| * End: |
| */ |