ipc_win32.cc

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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.
 */
 
/* DEBUG: section 54    Windows Interprocess Communication */
 
#include "squid.h"
#include "cache_cf.h"
#include "comm.h"
#include "comm/Connection.h"
#include "compat/socket.h"
#include "compat/unistd.h"
#include "fd.h"
#include "fde.h"
#include "globals.h"
#include "ip/Address.h"
#include "rfc1738.h"
#include "SquidConfig.h"
#include "SquidIpc.h"
#include "tools.h"
 
#include <cerrno>
#include <chrono>
#include <thread>
 
#if HAVE_MSWSOCK_H
#include <mswsock.h>
#endif
#include <process.h>
 
struct ipc_params {
    int type;
    int crfd;
    int cwfd;
    Ip::Address local_addr;
    struct addrinfo PS;
    const char *prog;
    char **args;
};
 
struct thread_params {
    int type;
    int rfd;
    int send_fd;
    const char *prog;
    pid_t pid;
};
 
static unsigned int __stdcall ipc_thread_1(void *params);
static unsigned int __stdcall ipc_thread_2(void *params);
 
static const char *ok_string = "OK\n";
static const char *err_string = "ERR\n";
static const char *shutdown_string = "$shutdown\n";
 
static const char *hello_string = "hi there\n";
#define HELLO_BUF_SZ 32
static char hello_buf[HELLO_BUF_SZ];
 
static int
ipcCloseAllFD(int prfd, int pwfd, int crfd, int cwfd)
{
    if (prfd >= 0)
        comm_close(prfd);
 
    if (prfd != pwfd)
        if (pwfd >= 0)
            comm_close(pwfd);
 
    if (crfd >= 0)
        comm_close(crfd);
 
    if (crfd != cwfd)
        if (cwfd >= 0)
            comm_close(cwfd);
 
    return -1;
}
 
static void
PutEnvironment()
{
    (void)setenv("SQUID_DEBUG", Debug::debugOptions, 1);
}
 
pid_t
ipcCreate(int type, const char *prog, const char *const args[], const char *name, Ip::Address &local_addr, int *rfd, int *wfd, void **hIpc)
{
    unsigned long thread;
 
    struct ipc_params params;
    int opt;
    int optlen = sizeof(opt);
    DWORD ecode = 0;
    pid_t pid;
 
    Ip::Address tmp_addr;
    struct addrinfo *aiCS = nullptr;
    struct addrinfo *aiPS = nullptr;
 
    int crfd = -1;
    int prfd = -1;
    int cwfd = -1;
    int pwfd = -1;
    int x;
 
    requirePathnameExists(name, prog);
 
    if (rfd)
        *rfd = -1;
 
    if (wfd)
        *wfd = -1;
 
    if (hIpc)
        *hIpc = nullptr;
 
    if (WIN32_OS_version != _WIN_OS_WINNT) {
        getsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char *) &opt, &optlen);
        opt = opt & ~(SO_SYNCHRONOUS_NONALERT | SO_SYNCHRONOUS_ALERT);
        setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char *) &opt, sizeof(opt));
    }
 
    if (type == IPC_TCP_SOCKET) {
        crfd = cwfd = comm_open_listener(SOCK_STREAM,
                                         IPPROTO_TCP,
                                         local_addr,
                                         COMM_NOCLOEXEC,
                                         name);
        prfd = pwfd = comm_open(SOCK_STREAM,
                                IPPROTO_TCP,    /* protocol */
                                local_addr,
                                0,          /* blocking */
                                name);
    } else if (type == IPC_UDP_SOCKET) {
        crfd = cwfd = comm_open(SOCK_DGRAM,
                                IPPROTO_UDP,
                                local_addr,
                                COMM_NOCLOEXEC,
                                name);
        prfd = pwfd = comm_open(SOCK_DGRAM,
                                IPPROTO_UDP,
                                local_addr,
                                0,
                                name);
    } else if (type == IPC_FIFO) {
        debugs(54, DBG_CRITICAL, "ipcCreate: " << prog << ": use IPC_TCP_SOCKET instead of IP_FIFO on Windows");
        assert(0);
    } else {
        assert(IPC_NONE);
    }
 
    debugs(54, 3, "ipcCreate: prfd FD " << prfd);
    debugs(54, 3, "ipcCreate: pwfd FD " << pwfd);
    debugs(54, 3, "ipcCreate: crfd FD " << crfd);
    debugs(54, 3, "ipcCreate: cwfd FD " << cwfd);
 
    if (WIN32_OS_version != _WIN_OS_WINNT) {
        getsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char *) &opt, &optlen);
        opt = opt | SO_SYNCHRONOUS_NONALERT;
        setsockopt(INVALID_SOCKET, SOL_SOCKET, SO_OPENTYPE, (char *) &opt, optlen);
    }
 
    if (crfd < 0) {
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: Failed to create child FD.");
        return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
    }
 
    if (pwfd < 0) {
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: Failed to create server FD.");
        return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
    }
 
// AYJ: these flags should be neutral, but if not IPv6 version needs adding
    if (type == IPC_TCP_SOCKET || type == IPC_UDP_SOCKET) {
 
        Ip::Address::InitAddr(aiPS);
 
        if (xgetsockname(pwfd, aiPS->ai_addr, &(aiPS->ai_addrlen) ) < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: getsockname: " << xstrerr(xerrno));
            Ip::Address::FreeAddr(aiPS);
            return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
        }
 
        tmp_addr = *aiPS;
        Ip::Address::FreeAddr(aiPS);
 
        debugs(54, 3, "ipcCreate: FD " << pwfd << " sockaddr " << tmp_addr );
 
        Ip::Address::InitAddr(aiCS);
 
        if (xgetsockname(crfd, aiCS->ai_addr, &(aiCS->ai_addrlen) ) < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: getsockname: " << xstrerr(xerrno));
            Ip::Address::FreeAddr(aiCS);
            return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
        }
 
        tmp_addr.setEmpty();
        tmp_addr = *aiCS;
        Ip::Address::FreeAddr(aiCS);
 
        debugs(54, 3, "ipcCreate: FD " << crfd << " sockaddr " << tmp_addr );
    }
 
    if (type == IPC_TCP_SOCKET) {
        if (xlisten(crfd, 1) < 0) {
            int xerrno = errno;
            debugs(54, DBG_IMPORTANT, "ipcCreate: listen FD " << crfd << ": " << xstrerr(xerrno));
            return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
        }
 
        debugs(54, 3, "ipcCreate: FD " << crfd << " listening...");
    }
 
    /* flush or else we get dup data if unbuffered_logs is set */
    logsFlush();
 
    params.type = type;
 
    params.crfd = crfd;
 
    params.cwfd = cwfd;
 
    params.PS = *aiPS;
 
    params.local_addr = local_addr;
 
    params.prog = prog;
 
    params.args = (char **) args;
 
    thread = _beginthreadex(nullptr, 0, ipc_thread_1, &params, 0, nullptr);
 
    if (thread == 0) {
        int xerrno = errno;
        debugs(54, DBG_IMPORTANT, "ipcCreate: _beginthread: " << xstrerr(xerrno));
        return ipcCloseAllFD(prfd, pwfd, crfd, cwfd);
    }
 
    /* NP: tmp_addr was left with eiether empty or aiCS in Ip::Address format */
    if (comm_connect_addr(pwfd, tmp_addr) == Comm::COMM_ERROR) {
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    }
 
    memset(hello_buf, '\0', HELLO_BUF_SZ);
    x = xrecv(prfd, (void *)hello_buf, HELLO_BUF_SZ - 1, 0);
 
    if (x < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: PARENT: hello read test failed");
        debugs(54, DBG_CRITICAL, "--> read: " << xstrerr(xerrno));
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    } else if (strcmp(hello_buf, hello_string)) {
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: PARENT: hello read test failed");
        debugs(54, DBG_CRITICAL, "--> read returned " << x);
        debugs(54, DBG_CRITICAL, "--> got '" << rfc1738_escape(hello_buf) << "'");
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    }
 
    x = xsend(pwfd, ok_string, strlen(ok_string), 0);
 
    if (x < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: PARENT: OK write test failed");
        debugs(54, DBG_CRITICAL, "--> read: " << xstrerr(xerrno));
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    }
 
    memset(hello_buf, '\0', HELLO_BUF_SZ);
    x = xrecv(prfd, (void *)hello_buf, HELLO_BUF_SZ - 1, 0);
 
    if (x < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: PARENT: OK read test failed");
        debugs(54, DBG_CRITICAL, "--> read: " << xstrerr(xerrno));
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    } else if (!strcmp(hello_buf, err_string)) {
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: PARENT: OK read test failed");
        debugs(54, DBG_CRITICAL, "--> read returned " << x);
        debugs(54, DBG_CRITICAL, "--> got '" << rfc1738_escape(hello_buf) << "'");
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    }
 
    hello_buf[x] = '\0';
    pid = atol(hello_buf);
    commUnsetFdTimeout(prfd);
    commSetNonBlocking(prfd);
    commSetNonBlocking(pwfd);
    commSetCloseOnExec(prfd);
    commSetCloseOnExec(pwfd);
 
    if (rfd)
        *rfd = prfd;
 
    if (wfd)
        *wfd = pwfd;
 
    fd_table[prfd].flags.ipc = true;
    fd_table[pwfd].flags.ipc = true;
    fd_table[crfd].flags.ipc = true;
    fd_table[cwfd].flags.ipc = true;
 
    if (Config.sleep_after_fork)
        std::this_thread::sleep_for(std::chrono::microseconds(Config.sleep_after_fork));
 
    if (GetExitCodeThread((HANDLE) thread, &ecode) && ecode == STILL_ACTIVE) {
        if (hIpc)
            *hIpc = (HANDLE) thread;
 
        return pid;
    } else {
        CloseHandle((HANDLE) thread);
        return ipcCloseAllFD(prfd, pwfd, -1, -1);
    }
}
 
static int
ipcSend(int cwfd, const char *buf, int len)
{
    const auto x = xsend(cwfd, buf, len, 0);
 
    if (x < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "sendto FD " << cwfd << ": " << xstrerr(xerrno));
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: hello write test failed");
    }
 
    return x;
}
 
static unsigned int __stdcall
ipc_thread_1(void *in_params)
{
    int t1, t2, t3, retval = -1;
    int p2c[2] = {-1, -1};
    int c2p[2] = {-1, -1};
    HANDLE hProcess = nullptr, thread = nullptr;
    pid_t pid = -1;
 
    struct thread_params thread_params;
    ssize_t x;
    int fd = -1;
    char *str;
    STARTUPINFO si;
    PROCESS_INFORMATION pi;
    long F;
    int prfd_ipc = -1, pwfd_ipc = -1, crfd_ipc = -1, cwfd_ipc = -1;
    char *prog = nullptr, *buf1 = nullptr;
 
    Ip::Address PS_ipc;
    Ip::Address CS_ipc;
    struct addrinfo *aiPS_ipc = nullptr;
    struct addrinfo *aiCS_ipc = nullptr;
 
    struct ipc_params *params = (struct ipc_params *) in_params;
    int type = params->type;
    int crfd = params->crfd;
    int cwfd = params->cwfd;
    char **args = params->args;
 
    Ip::Address PS = params->PS;
    Ip::Address local_addr = params->local_addr;
 
    const size_t bufSz = 8192;
    buf1 = (char *)xcalloc(1, bufSz);
    strcpy(buf1, params->prog);
    prog = strtok(buf1, w_space);
 
    if ((str = strrchr(prog, '/')))
        prog = ++str;
 
    if ((str = strrchr(prog, '\\')))
        prog = ++str;
 
    prog = xstrdup(prog);
 
    if (type == IPC_TCP_SOCKET) {
        debugs(54, 3, "ipcCreate: calling accept on FD " << crfd);
 
        if ((fd = xaccept(crfd, nullptr, nullptr)) < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: FD " << crfd << " accept: " << xstrerr(xerrno));
            goto cleanup;
        }
 
        debugs(54, 3, "ipcCreate: CHILD accepted new FD " << fd);
        comm_close(crfd);
        snprintf(buf1, bufSz-1, "%s CHILD socket", prog);
        fd_open(fd, FD_SOCKET, buf1);
        fd_table[fd].flags.ipc = 1;
        cwfd = crfd = fd;
    } else if (type == IPC_UDP_SOCKET) {
        if (comm_connect_addr(crfd, params->PS) == Comm::COMM_ERROR)
            goto cleanup;
    }
 
    x = xsend(cwfd, hello_string, strlen(hello_string) + 1, 0);
 
    if (x < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "sendto FD " << cwfd << ": " << xstrerr(xerrno));
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: hello write test failed");
        goto cleanup;
    }
 
    PutEnvironment();
    memset(buf1, '\0', bufSz);
    x = xrecv(crfd, (void *)buf1, bufSz-1, 0);
 
    if (x < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: OK read test failed");
        debugs(54, DBG_CRITICAL, "--> read: " << xstrerr(xerrno));
        goto cleanup;
    } else if (strcmp(buf1, ok_string)) {
        debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: OK read test failed");
        debugs(54, DBG_CRITICAL, "--> read returned " << x);
        debugs(54, DBG_CRITICAL, "--> got '" << rfc1738_escape(hello_buf) << "'");
        goto cleanup;
    }
 
    /* assign file descriptors to child process */
    if (_pipe(p2c, 1024, _O_BINARY | _O_NOINHERIT) < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: pipe: " << xstrerr(xerrno));
        ipcSend(cwfd, err_string, strlen(err_string));
        goto cleanup;
    }
 
    if (_pipe(c2p, 1024, _O_BINARY | _O_NOINHERIT) < 0) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: pipe: " << xstrerr(xerrno));
        ipcSend(cwfd, err_string, strlen(err_string));
        goto cleanup;
    }
 
    if (type == IPC_UDP_SOCKET) {
        snprintf(buf1, bufSz, "%s(%ld) <-> ipc CHILD socket", prog, -1L);
        crfd_ipc = cwfd_ipc = comm_open(SOCK_DGRAM, IPPROTO_UDP, local_addr, 0, buf1);
 
        if (crfd_ipc < 0) {
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: Failed to create child FD for " << prog << ".");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        snprintf(buf1, bufSz, "%s(%ld) <-> ipc PARENT socket", prog, -1L);
        prfd_ipc = pwfd_ipc = comm_open(SOCK_DGRAM, IPPROTO_UDP, local_addr, 0, buf1);
 
        if (pwfd_ipc < 0) {
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: Failed to create server FD for " << prog << ".");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        Ip::Address::InitAddr(aiPS_ipc);
 
        if (xgetsockname(pwfd_ipc, aiPS_ipc->ai_addr, &(aiPS_ipc->ai_addrlen)) < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: getsockname: " << xstrerr(xerrno));
            ipcSend(cwfd, err_string, strlen(err_string));
            Ip::Address::FreeAddr(aiPS_ipc);
            goto cleanup;
        }
 
        PS_ipc = *aiPS_ipc;
        Ip::Address::FreeAddr(aiPS_ipc);
 
        debugs(54, 3, "ipcCreate: FD " << pwfd_ipc << " sockaddr " << PS_ipc);
 
        Ip::Address::InitAddr(aiCS_ipc);
 
        if (xgetsockname(crfd_ipc, aiCS_ipc->ai_addr, &(aiCS_ipc->ai_addrlen)) < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: getsockname: " << xstrerr(xerrno));
            ipcSend(cwfd, err_string, strlen(err_string));
            Ip::Address::FreeAddr(aiCS_ipc);
            goto cleanup;
        }
 
        CS_ipc = *aiCS_ipc;
        Ip::Address::FreeAddr(aiCS_ipc);
 
        debugs(54, 3, "ipcCreate: FD " << crfd_ipc << " sockaddr " << CS_ipc);
 
        if (comm_connect_addr(pwfd_ipc, CS_ipc) == Comm::COMM_ERROR) {
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        fd = crfd;
 
        if (comm_connect_addr(crfd_ipc, PS_ipc) == Comm::COMM_ERROR) {
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
    }               /* IPC_UDP_SOCKET */
 
    t1 = dup(0);
 
    t2 = dup(1);
 
    t3 = dup(2);
 
    dup2(c2p[0], 0);
 
    dup2(p2c[1], 1);
 
    dup2(fileno(DebugStream()), 2);
 
    close(c2p[0]);
 
    close(p2c[1]);
 
    commUnsetNonBlocking(fd);
 
    memset(&si, 0, sizeof(STARTUPINFO));
 
    si.cb = sizeof(STARTUPINFO);
 
    si.hStdInput = (HANDLE) _get_osfhandle(0);
 
    si.hStdOutput = (HANDLE) _get_osfhandle(1);
 
    si.hStdError = (HANDLE) _get_osfhandle(2);
 
    si.dwFlags = STARTF_USESTDHANDLES;
 
    /* Make sure all other valid handles are not inerithable */
    for (x = 3; x < Squid_MaxFD; ++x) {
        if ((F = _get_osfhandle(x)) == -1)
            continue;
 
        SetHandleInformation((HANDLE) F, HANDLE_FLAG_INHERIT, 0);
    }
 
    *buf1 = '\0';
    strcpy(buf1 + 4096, params->prog);
    str = strtok(buf1 + 4096, w_space);
 
    do {
        strcat(buf1, str);
        strcat(buf1, " ");
    } while ((str = strtok(nullptr, w_space)));
 
    x = 1;
 
    while (args[x]) {
        strcat(buf1, args[x]);
        ++x;
        strcat(buf1, " ");
    }
 
    if (CreateProcess(buf1 + 4096, buf1, nullptr, nullptr, TRUE, CREATE_NO_WINDOW,
                      nullptr, nullptr, &si, &pi)) {
        pid = pi.dwProcessId;
        hProcess = pi.hProcess;
        CloseHandle(pi.hThread);
    } else {
        pid = -1;
        x = GetLastError();
    }
 
    dup2(t1, 0);
    dup2(t2, 1);
    dup2(t3, 2);
    close(t1);
    close(t2);
    close(t3);
 
    if (pid == -1) {
        debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: " << params->prog << ": " << xstrerr(x));
 
        ipcSend(cwfd, err_string, strlen(err_string));
        goto cleanup;
    }
 
    if (type == IPC_UDP_SOCKET) {
        WSAPROTOCOL_INFO wpi;
 
        memset(&wpi, 0, sizeof(wpi));
 
        if (SOCKET_ERROR == WSADuplicateSocket(crfd_ipc, pid, &wpi)) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: WSADuplicateSocket: " << xstrerr(xerrno));
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        x = xwrite(c2p[1], (const char *) &wpi, sizeof(wpi));
 
        if (x < (ssize_t)sizeof(wpi)) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: write FD " << c2p[1] << ": " << xstrerr(xerrno));
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: " << prog << ": socket exchange failed");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        x = xread(p2c[0], buf1, bufSz-1);
 
        if (x < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: read FD " << p2c[0] << ": " << xstrerr(xerrno));
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: " << prog << ": socket exchange failed");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        } else if (strncmp(buf1, ok_string, strlen(ok_string))) {
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: " << prog << ": socket exchange failed");
            debugs(54, DBG_CRITICAL, "--> read returned " << x);
            buf1[x] = '\0';
            debugs(54, DBG_CRITICAL, "--> got '" << rfc1738_escape(buf1) << "'");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        x = xwrite(c2p[1], (const char *) &PS_ipc, sizeof(PS_ipc));
 
        if (x < (ssize_t)sizeof(PS_ipc)) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: write FD " << c2p[1] << ": " << xstrerr(xerrno));
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: " << prog << ": socket exchange failed");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        x = xread(p2c[0], buf1, bufSz-1);
 
        if (x < 0) {
            int xerrno = errno;
            debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: read FD " << p2c[0] << ": " << xstrerr(xerrno));
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: " << prog << ": socket exchange failed");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        } else if (strncmp(buf1, ok_string, strlen(ok_string))) {
            debugs(54, DBG_CRITICAL, "ERROR: ipcCreate: CHILD: " << prog << ": socket exchange failed");
            debugs(54, DBG_CRITICAL, "--> read returned " << x);
            buf1[x] = '\0';
            debugs(54, DBG_CRITICAL, "--> got '" << rfc1738_escape(buf1) << "'");
            ipcSend(cwfd, err_string, strlen(err_string));
            goto cleanup;
        }
 
        x = xsend(pwfd_ipc, ok_string, strlen(ok_string), 0);
        x = xrecv(prfd_ipc, (void *)(buf1 + 200), bufSz -1 - 200, 0);
        assert((size_t) x == strlen(ok_string)
               && !strncmp(ok_string, buf1 + 200, strlen(ok_string)));
    }               /* IPC_UDP_SOCKET */
 
    snprintf(buf1, bufSz-1, "%s(%ld) CHILD socket", prog, (long int) pid);
 
    fd_note(fd, buf1);
 
    if (prfd_ipc != -1) {
        snprintf(buf1, bufSz-1, "%s(%ld) <-> ipc CHILD socket", prog, (long int) pid);
        fd_note(crfd_ipc, buf1);
        snprintf(buf1, bufSz-1, "%s(%ld) <-> ipc PARENT socket", prog, (long int) pid);
        fd_note(prfd_ipc, buf1);
    }
 
    /* else {                       IPC_TCP_SOCKET */
    /*     commConfigureLinger(fd, OnOff::off); */
    /*  } */
    thread_params.prog = prog;
 
    thread_params.send_fd = cwfd;
 
    thread_params.pid = pid;
 
    if ((thread_params.type = type) == IPC_TCP_SOCKET)
        thread_params.rfd = p2c[0];
    else
        thread_params.rfd = prfd_ipc;
 
    thread = (HANDLE)_beginthreadex(nullptr, 0, ipc_thread_2, &thread_params, 0, nullptr);
 
    if (!thread) {
        int xerrno = errno;
        debugs(54, DBG_CRITICAL, "ipcCreate: CHILD: _beginthreadex: " << xstrerr(xerrno));
        ipcSend(cwfd, err_string, strlen(err_string));
        goto cleanup;
    }
 
    snprintf(buf1, bufSz-1, "%ld\n", (long int) pid);
 
    if (-1 == ipcSend(cwfd, buf1, strlen(buf1)))
        goto cleanup;
 
    debugs(54, 2, "ipc(" << prog << "," << pid << "): started successfully");
 
    /* cycle */
    for (;;) {
        x = xrecv(crfd, (void *)buf1, bufSz-1, 0);
 
        if (x <= 0) {
            debugs(54, 3, "ipc(" << prog << "," << pid << "): " << x << " bytes received from parent. Exiting...");
            break;
        }
 
        buf1[x] = '\0';
 
        if (type == IPC_UDP_SOCKET && !strcmp(buf1, shutdown_string)) {
            debugs(54, 3, "ipc(" << prog << "," << pid << "): request for shutdown received from parent. Exiting...");
 
            TerminateProcess(hProcess, 0);
            break;
        }
 
        debugs(54, 5, "ipc(" << prog << "," << pid << "): received from parent: " << rfc1738_escape_unescaped(buf1));
 
        if (type == IPC_TCP_SOCKET)
            x = xwrite(c2p[1], buf1, x);
        else
            x = xsend(pwfd_ipc, buf1, x, 0);
 
        if (x <= 0) {
            debugs(54, 3, "ipc(" << prog << "," << pid << "): " << x << " bytes written to " << prog << ". Exiting...");
 
            break;
        }
    }
 
    retval = 0;
 
cleanup:
 
    if (c2p[1] != -1)
        close(c2p[1]);
 
    if (fd_table[crfd].flags.open)
        ipcCloseAllFD(-1, -1, crfd, cwfd);
 
    if (prfd_ipc != -1) {
        xsend(crfd_ipc, shutdown_string, strlen(shutdown_string), 0);
        shutdown(crfd_ipc, SD_BOTH);
        shutdown(prfd_ipc, SD_BOTH);
    }
 
    ipcCloseAllFD(prfd_ipc, pwfd_ipc, crfd_ipc, cwfd_ipc);
 
    if (hProcess && WAIT_OBJECT_0 !=
            WaitForSingleObject(hProcess, type == IPC_UDP_SOCKET ? 12000 : 5000)) {
 
        getCurrentTime();
        debugs(54, DBG_CRITICAL, "ipc(" << prog << "," << pid << "): WARNING: " << prog <<
               " didn't exit in " << (type == IPC_UDP_SOCKET ? 12 : 5) << " seconds.");
 
    }
 
    if (thread && WAIT_OBJECT_0 != WaitForSingleObject(thread, 3000)) {
        getCurrentTime();
        debugs(54, DBG_CRITICAL, "ipc(" << prog << "," << pid << "): WARNING: ipc_thread_2 didn't exit in 3 seconds.");
 
    }
 
    getCurrentTime();
 
    if (!retval)
        debugs(54, 2, "ipc(" << prog << "," << pid << "): normal exit");
 
    xfree(buf1);
    xfree(prog);
 
    if (thread)
        CloseHandle(thread);
 
    if (hProcess)
        CloseHandle(hProcess);
 
    if (p2c[0] != -1)
        close(p2c[0]);
 
    return retval;
}
 
static unsigned int __stdcall
ipc_thread_2(void *in_params)
{
    int x;
 
    struct thread_params *params = (struct thread_params *) in_params;
    int type = params->type;
    int rfd = params->rfd;
    int send_fd = params->send_fd;
    char *prog = xstrdup(params->prog);
    pid_t pid = params->pid;
    const size_t bufSz = 8192;
    char *buf2 = (char *)xcalloc(1, bufSz);
 
    for (;;) {
        if (type == IPC_TCP_SOCKET)
            x = xread(rfd, buf2, bufSz-1);
        else
            x = xrecv(rfd, (void *)buf2, bufSz-1, 0);
 
        if ((x <= 0 && type == IPC_TCP_SOCKET) ||
                (x < 0 && type == IPC_UDP_SOCKET)) {
            debugs(54, 3, "ipc(" << prog << "," << pid << "): " << x << " bytes read from " << prog << ". Exiting...");
 
            break;
        }
 
        buf2[x] = '\0';
 
        if (type == IPC_UDP_SOCKET && !strcmp(buf2, shutdown_string)) {
            debugs(54, 3, "ipc(" << prog << "," << pid << "): request for shutdown received. Exiting...");
            break;
        }
 
        if (x >= 2) {
            if ((buf2[x - 1] == '\n') && (buf2[x - 2] == '\r')) {
                buf2[x - 2] = '\n';
                buf2[x - 1] = '\0';
                --x;
            }
        }
 
        debugs(54, 5, "ipc(" << prog << "," << pid << "): received from child : " << rfc1738_escape_unescaped(buf2));
 
        x = xsend(send_fd, buf2, x, 0);
 
        if ((x <= 0 && type == IPC_TCP_SOCKET) ||
                (x < 0 && type == IPC_UDP_SOCKET)) {
            debugs(54, 3, "ipc(" << prog << "," << pid << "): " << x << " bytes sent to parent. Exiting...");
 
            break;
        }
    }
 
    xfree(prog);
    xfree(buf2);
    return 0;
}