fde.h

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/*
 * Copyright (C) 1996-2025 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.
 */
 
#ifndef SQUID_SRC_FDE_H
#define SQUID_SRC_FDE_H
 
#include "base/CodeContext.h" /* XXX: Remove by de-inlining ctor and clear() */
#include "base/forward.h"
#include "comm.h"
#include "defines.h"
#include "ip/Address.h"
#include "ip/forward.h"
#include "security/forward.h"
#include "typedefs.h" //DRCB, DWCB
 
#if USE_DELAY_POOLS
#include "MessageBucket.h"
class ClientInfo;
#endif
class dwrite_q;
 
typedef int READ_HANDLER(int, char *, int);
 
typedef int WRITE_HANDLER(int, const char *, int);
 
class _fde_disk
{
public:
    _fde_disk() { wrt_handle = nullptr; }
 
    DWCB *wrt_handle;
    void *wrt_handle_data = nullptr;
    dwrite_q *write_q = nullptr;
    dwrite_q *write_q_tail = nullptr;
    off_t offset = 0;
};
 
class fde
{
 
public:
 
    // TODO: Merge with comm_init() to reduce initialization order dependencies.
    static void Init();
 
    fde() {
        *ipaddr = 0;
        *desc = 0;
        read_handler = nullptr;
        write_handler = nullptr;
        readMethod_ = nullptr;
        writeMethod_ = nullptr;
    }
 
    void clear() { *this = fde(); }
 
    bool closing() const { return flags.close_request; }
 
    void setIo(READ_HANDLER *, WRITE_HANDLER *);
 
    void useDefaultIo();
 
    void useBufferedIo(READ_HANDLER *, WRITE_HANDLER *);
 
    int read(int fd, char *buf, int len) { return readMethod_(fd, buf, len); }
    int write(int fd, const char *buf, int len) { return writeMethod_(fd, buf, len); }
 
    /* NOTE: memset is used on fdes today. 20030715 RBC */
    static void DumpStats(StoreEntry *);
 
    char const *remoteAddr() const;
    void dumpStats(StoreEntry &, int) const;
    bool readPending(int) const;
 
    void noteUse() { ++pconn.uses; }
 
public:
 
    static fde* Table;
 
    unsigned int type = 0;
    unsigned short remote_port = 0;
 
    Ip::Address local_addr;
    tos_t tosToServer = '\0';      
    nfmark_t nfmarkToServer = 0;   
    int sock_family = 0;
    char ipaddr[MAX_IPSTRLEN];            /* dotted decimal address of peer */
    char desc[FD_DESC_SZ];
 
    struct _fde_flags {
        bool open = false;
        bool close_request = false; 
        bool write_daemon = false;
        bool socket_eof = false;
        bool nonblocking = false;
        bool ipc = false;
        bool called_connect = false;
        bool nodelay = false;
        bool read_pending = false;
        //bool write_pending; //XXX seems not to be used
        bool transparent = false;
        bool harshClosureRequested = false;
    } flags;
 
    int64_t bytes_read = 0;
    int64_t bytes_written = 0;
 
    struct {
        int uses = 0;                   /* ie # req's over persistent conn */
    } pconn;
 
#if USE_DELAY_POOLS
    ClientInfo * clientInfo = nullptr;
    MessageBucket::Pointer writeQuotaHandler; 
#endif
    unsigned epoll_state = 0;
 
    _fde_disk disk;
    PF *read_handler;
    void *read_data = nullptr;
    PF *write_handler;
    void *write_data = nullptr;
    AsyncCall::Pointer timeoutHandler;
    time_t timeout = 0;
    time_t writeStart = 0;
    void *lifetime_data = nullptr;
    AsyncCall::Pointer closeHandler;
    AsyncCall::Pointer halfClosedReader; 
    Security::SessionPointer ssl;
    Security::ContextPointer dynamicTlsContext; 
#if _SQUID_WINDOWS_
    struct {
        long handle = (long)nullptr;
    } win32;
#endif
    tos_t tosFromServer = '\0';        
    unsigned int nfConnmarkFromServer = 0; 
    // TODO: Remove: Auto-convert legacy SetSelect() callers to AsyncCalls like
    // comm_add_close_handler(CLCB) does, making readMethod_/writeMethod_
    // AsyncCalls and giving each read/write a dedicated context instead.
    CodeContextPointer codeContext;
 
private:
    // I/O methods connect Squid to the device/stack/library fde represents
    READ_HANDLER *readMethod_ = nullptr; 
    WRITE_HANDLER *writeMethod_ = nullptr; 
};
 
#define fd_table fde::Table
 
int fdNFree(void);
 
inline int
FD_READ_METHOD(int fd, char *buf, int len)
{
    return fd_table[fd].read(fd, buf, len);
}
 
inline int
FD_WRITE_METHOD(int fd, const char *buf, int len)
{
    return fd_table[fd].write(fd, buf, len);
}
 
#endif /* SQUID_SRC_FDE_H */