/*
 * See the dyninst/COPYRIGHT file for copyright information.
 *
 * We provide the Paradyn Tools (below described as "Paradyn")
 * on an AS IS basis, and do not warrant its validity or performance.
 * We reserve the right to update, modify, or discontinue this
 * software at any time.  We shall have no obligation to supply such
 * updates or modifications or any other form of support to you.
 *
 * By your use of Paradyn, you understand and agree that we (or any
 * other person or entity with proprietary rights in Paradyn) are
 * under no obligation to provide either maintenance services,
 * update services, notices of latent defects, or correction of
 * defects for Paradyn.
 *
 * 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; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * 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
 */

/************************************************************************
 * $Id: RTposix.c,v 1.37 2008/04/11 23:30:45 legendre Exp $
 * RTposix.c: runtime instrumentation functions for generic posix.
 ************************************************************************/

#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <memory.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/un.h>
#include <unistd.h>

#include "h/dyninstAPI_RT.h"
#include "src/RTcommon.h"
#include "src/RTheap.h"

#define SOCKLEN_T socklen_t

#if !(defined(arch_power) && defined(os_linux))
void
RTmutatedBinary_init()
{
    return;
}
#endif

#if defined(__GNUC) || defined(__GNUC__)
#    if defined(DYNINST_RT_STATIC_LIB)
/*
 * In the static version of the library, constructors cannot be
 * used to run code at initialization. See DYNINSTglobal_ctors_handler.
 */
void
libdyninstAPI_RT_init(void);
#    else
void
libdyninstAPI_RT_init(void) __attribute__((constructor));
#    endif
#endif

#if defined(cap_async_events)
struct passwd* passwd_info = NULL;
#endif

void
libdyninstAPI_RT_init()
{
    static int initCalledOnce = 0;

    rtdebug_printf("%s[%d]:  DYNINSTinit:  welcome to libdyninstAPI_RT_init()\n",
                   __FILE__, __LINE__);

    if(initCalledOnce) return;
    initCalledOnce++;

    DYNINSTinit();
    rtdebug_printf("%s[%d]:  did DYNINSTinit\n", __FILE__, __LINE__);
}

/************************************************************************
 * void DYNINSTasyncConnect(int pid)
 *
 * Connect to mutator's async handler thread. <pid> is pid of mutator
 ************************************************************************/

static int  async_socket     = -1;
static int  needToDisconnect = 0;
static char socket_path[255];

int
DYNINSTasyncConnect(int pid)
{
    if(DYNINSTstaticMode) return 0;
#if defined(cap_async_events)
    int                sock_fd;
    struct sockaddr_un sadr;
    int                res;
    int                mutatee_pid;
    uid_t              euid;

    rtdebug_printf("%s[%d]:  DYNINSTasyncConnnect:  entry\n", __FILE__, __LINE__);
    rtdebug_printf("%s[%d]:  DYNINSTinit:  before geteuid\n", __FILE__, __LINE__);

    euid        = geteuid();
    passwd_info = getpwuid(euid);
    assert(passwd_info);

    if(async_socket != -1)
    {
        fprintf(stderr, "%s[%d]: - DYNINSTasyncConnect already initialized\n", __FILE__,
                __LINE__);

        rtdebug_printf("%s[%d]:  DYNINSTasyncConnnect:  already connected\n", __FILE__,
                       __LINE__);
        return 0;
    }

    rtdebug_printf("%s[%d]:  DYNINSTasyncConnnect:  before socket 2\n", __FILE__,
                   __LINE__);
    mutatee_pid = getpid();

    snprintf(socket_path, (size_t) 255, "%s/dyninstAsync.%s.%d.%d", P_tmpdir,
             passwd_info->pw_name, pid, mutatee_pid);

    rtdebug_printf("%s[%d]:  DYNINSTasyncConnnect:  before socket: %s\n", __FILE__,
                   __LINE__, socket_path);

    errno = 0;

    sock_fd = socket(PF_UNIX, SOCK_STREAM, 0);

    if(sock_fd < 0)
    {
        fprintf(stderr, "%s[%d]: DYNINSTasyncConnect() socket(%s): %s\n", __FILE__,
                __LINE__, socket_path, strerror(errno));
        abort();
    }

    rtdebug_printf("%s[%d]:  DYNINSTasyncConnnect:  after socket\n", __FILE__, __LINE__);

    sadr.sun_family = PF_UNIX;
    strcpy(sadr.sun_path, socket_path);

    rtdebug_printf("%s[%d]:  DYNINSTasyncConnnect:  before connect\n", __FILE__,
                   __LINE__);
    res   = 0;
    errno = 0;

    res = connect(sock_fd, (struct sockaddr*) &sadr, sizeof(sadr));

    if(res < 0)
    {
        perror("DYNINSTasyncConnect() connect()");
    }

    rtdebug_printf(
        "%s[%d]:  DYNINSTasyncConnnect:  after connect to %s, res = %d, -- %s\n",
        __FILE__, __LINE__, socket_path, res, strerror(errno));

    /* maybe need to do fcntl to set nonblocking writes on this fd */

    if(async_socket == -1)
    {
        rtdebug_printf("%s[%d]:  WARN:  async socket has not been reset!!\n", __FILE__,
                       __LINE__);
    }

    async_socket = sock_fd;

    needToDisconnect = 1;

    /* atexit(exit_func); */
    rtdebug_printf("%s[%d]:  leaving DYNINSTasyncConnect\n", __FILE__, __LINE__);
    return 1;
#else
    fprintf(stderr, "%s[%d]:  called DYNINSTasyncConect when async_events disabled\n",
            __FILE__, __LINE__);
    return 0;
#endif
}

int
DYNINSTasyncDisconnect()
{
    if(DYNINSTstaticMode) return 0;
    rtdebug_printf("%s[%d]:  welcome to DYNINSTasyncDisconnect\n", __FILE__, __LINE__);
    if(needToDisconnect)
    {
        close(async_socket);
        needToDisconnect = 0;
    }
    async_socket = -1;
    return 0;
}

int
DYNINSTwriteEvent(void* ev, size_t sz)
{
    ssize_t res;

    if(DYNINSTstaticMode) return 0;

    rtdebug_printf("%s[%d]:  welcome to DYNINSTwriteEvent: %zu bytes\n", __FILE__,
                   __LINE__, sz);
    if(-1 == async_socket)
    {
        rtdebug_printf("%s[%d]:  failed to DYNINSTwriteEvent, no socket\n", __FILE__,
                       __LINE__);
        return -1;
    }

try_again:
    res = write(async_socket, ev, sz);
    if(-1 == res)
    {
        if(errno == EINTR || errno == EAGAIN)
            goto try_again;
        else
        {
            perror("write");
            return -1;
        }
    }
    if((size_t) res != sz)
    {
        /*  maybe we need logic to handle partial writes? */
        fprintf(stderr, "%s[%d]:  partial ? write error, %zd bytes, should be %zu\n",
                __FILE__, __LINE__, res, sz);
        return -1;
    }
    return 0;
}

// Important note: addr will be zero in two cases here
// One is the case where we're doing a constrained low mmap, in which case MAP_32BIT
// is precisely correct. The other is the case where our
// constrained map attempts have failed, and we're doing a scan for first available
// mappable page. In that case, MAP_32BIT does no harm.
void*
map_region(void* addr, int len, int fd)
{
    void* result;
    int   flags = DYNINSTheap_mmapFlags;
#if defined(arch_x86_64)
    if(addr == 0) flags |= MAP_32BIT;
#endif
    result = mmap(addr, len, PROT_READ | PROT_WRITE | PROT_EXEC, flags, fd, 0);
    if(result == MAP_FAILED) return NULL;
    return result;
}

int
unmap_region(void* addr, int len)
{
    int result;
    result = munmap(addr, len);
    if(result == -1) return 0;
    return 1;
}

#if defined(cap_mutatee_traps)
extern void
dyninstTrapHandler(int sig, siginfo_t* info, void* context);

int
DYNINSTinitializeTrapHandler()
{
    int              result;
    struct sigaction new_handler;
    int              signo = SIGTRAP;

    // If environment variable DYNINST_SIGNAL_TRAMPOLINE_SIGILL is set,
    // we use SIGILL as the signal for signal trampoline.
    // The mutatee has to be generated with DYNINST_SIGNAL_TRAMPOLINE_SIGILL set
    // so that the mutator will generates illegal instructions as trampolines.
    if(getenv("DYNINST_SIGNAL_TRAMPOLINE_SIGILL"))
    {
        signo = SIGILL;
    }

    new_handler.sa_sigaction = dyninstTrapHandler;
    // new_handler.sa_restorer = NULL; obsolete
    sigemptyset(&new_handler.sa_mask);
    new_handler.sa_flags = SA_SIGINFO | SA_NODEFER;

    result = sigaction(signo, &new_handler, NULL);
    return (result == 0) ? 1 /*Success*/ : 0 /*Fail*/;
}

#endif