inet_gethost.c

来自「OTP是开放电信平台的简称」· C语言 代码 · 共 2,324 行 · 第 1/4 页

    case NO_ADDRESS:
#endif
#endif
	return ERRCODE_NO_DATA;
#endif
    default:
	return ERRCODE_NETDB_INTERNAL;
    }
}

static char *errcode_to_string(int errcode)
{
    switch (errcode) {
    case ERRCODE_NOTSUP:
	return "enotsup";
    case ERRCODE_HOST_NOT_FOUND:
	/* 
	 * I would preffer 
	 * return "host_not_found";
	 * but have to keep compatibility with the old 
	 * inet_gethost's error codes... 
	 */
	return "notfound";
    case ERRCODE_TRY_AGAIN:
	return "try_again";
    case ERRCODE_NO_RECOVERY:
	return "no_recovery";
    case ERRCODE_NO_DATA:
	return "no_data";
    default:
	/*case ERRCODE_NETDB_INTERNAL:*/
	return "netdb_internal";
    }
}
	
static size_t build_error_reply(SerialType serial, int errnum, 
				AddrByte **preply,
				size_t *preply_size)
{
    char *errstring = errcode_to_string(errnum);
    int string_need = strlen(errstring) + 1; /* a '\0' too */
    unsigned need;
    AddrByte *ptr;

    need = PACKET_BYTES + 4 /* Serial */ + 1 /* Unit */ + string_need;
    if (*preply_size < need) {
	if (*preply_size == 0) {
	    *preply = ALLOC((*preply_size = need));
	} else {
	    *preply = REALLOC(*preply, 
			      (*preply_size = need));
	}
    }
    ptr = *preply;
    PUT_PACKET_BYTES(ptr,need - PACKET_BYTES);
    ptr += PACKET_BYTES;
    put_int32(ptr,serial);
    ptr +=4;
    *ptr++ = (AddrByte) 0; /* 4 or 16 */
    strcpy((char*)ptr, errstring);
    return need;
}
    


static size_t build_reply(SerialType serial, struct hostent *he, 
			  AddrByte **preply, size_t *preply_size)
{
    unsigned need;
    int strings_need;
    int num_strings;
    int num_addresses;
    int i;
    AddrByte *ptr;
    int unit = he->h_length;

    for (num_addresses = 0; he->h_addr_list[num_addresses] != NULL; 
	 ++num_addresses)
	;
    strings_need = strlen(he->h_name) + 1; /* 1 for null byte */
    num_strings = 1;
    if (he->h_aliases) {
	for(i=0; he->h_aliases[i] != NULL; ++i) {
	    strings_need += strlen(he->h_aliases[i]) + 1;
	    ++num_strings;
	}
    }
    
    need = PACKET_BYTES + 
	4 /* Serial */ + 1 /* Unit */ + 4 /* Naddr */ +
	(unit * num_addresses) /* Address bytes */ +
	4 /* Nnames */ + strings_need /* The name and alias strings */;

    if (*preply_size < need) {
	if (*preply_size == 0) {
	    *preply = ALLOC((*preply_size = need));
	} else {
	    *preply = REALLOC(*preply, 
			      (*preply_size = need));
	}
    }
    ptr = *preply;
    PUT_PACKET_BYTES(ptr,need - PACKET_BYTES);
    ptr += PACKET_BYTES;
    put_int32(ptr,serial);
    ptr +=4;
    *ptr++ = (AddrByte) unit; /* 4 or 16 */
    put_int32(ptr, num_addresses);
    ptr += 4;
    for (i = 0; i < num_addresses; ++i) {
	memcpy(ptr, he->h_addr_list[i], unit);
	ptr += unit;
    }
    put_int32(ptr, num_strings);
    ptr += 4;
    strcpy((char*)ptr, he->h_name);
    ptr += 1 + strlen(he->h_name);
    for (i = 0; i < (num_strings - 1); ++i) {
	strcpy((char*)ptr, he->h_aliases[i]);
	ptr += 1 + strlen(he->h_aliases[i]);
    }
    return need;
}

/*
 * Encode/decode/read/write 
 */

static int get_int32(AddrByte *b) 
{
    int res;
    res = (unsigned) b[3];
    res |= ((unsigned) b[2]) << 8;
    res |= ((unsigned) b[1]) << 16;
    res |= ((unsigned) b[0]) << 24;
    return res;
}

static void put_int32(AddrByte *buff, int value)
{
    buff[0] = (((unsigned) value) >> 24) & 0xFF;
    buff[1] = (((unsigned) value) >> 16) & 0xFF;
    buff[2] = (((unsigned) value) >> 8) & 0xFF;
    buff[3] = ((unsigned) value) & 0xFF;
}
#ifdef WIN32

static int read_int32(HANDLE fd, int *res)
{
    AddrByte b[4];
    int r;
    if ((r = read_exact(fd,b,4)) < 0) {
	return -1;
    } else if (r == 0) {
	return 0;
    } else {
	*res = (unsigned) b[3];
	*res |= ((unsigned) b[2]) << 8;
	*res |= ((unsigned) b[1]) << 16;
	*res |= ((unsigned) b[0]) << 24;
    }
    return 4;
}

static int read_exact(HANDLE fd, void *vbuff, DWORD nbytes)
{
    DWORD ret,got;
    BOOL stat;
    char *buff = vbuff;

    got = 0;
    for(;;) {
	stat = ReadFile(fd, buff, nbytes - got, &ret, NULL);
	if (!stat) {
	    if (GetLastError() == ERROR_BROKEN_PIPE) {
		DEBUGF(1, ("End of file while reading from pipe."));
		return 0;
	    } else {
		DEBUGF(1, ("Error while reading from pipe,"
			   " errno = %d",
			   GetLastError()));
		return -1;
	    }
	}
	if (ret < nbytes - got) {
	    got += ret;
	    buff += ret;
	} else {
	    return nbytes;
	}
    }
}

static int write_exact(HANDLE fd, AddrByte *buff, DWORD len) 
{
    DWORD res,stat;
    DWORD x = len;
    for(;;) {
	
	stat = WriteFile(fd,buff,x,&res,NULL);
	if (!stat) {
	    if (GetLastError() == ERROR_BROKEN_PIPE) {
		return 0;
	    } else {
		return -1;
	    }
	} else if (res < x) {
	    /* Hmmm, blocking write but not all written, could this happen
	       if the other end was closed during the operation? Well, 
	       it costs very little to handle anyway... */
	    x -= res;
	    buff += res;
	} else {
	    return len;
	}
    }
}

DWORD WINAPI reader(void *data) {
    MesQ *mq = (MesQ *) data;
    QueItem *m;
    int siz;
    int r;
    HANDLE inp = GetStdHandle(STD_INPUT_HANDLE);

    for (;;) {
	if ((r = READ_PACKET_BYTES(inp,&siz)) != 4) {
	    DEBUGF(1,("Erlang has closed (reading)"));
	    exit(0);
	}
	m = ALLOC(sizeof(QueItem) - 1 + siz);
	if (read_exact(inp, m->request, siz) != siz) {
	    fatal("Unexpected end of file on main input, errno = %d",errno);
	}
	if (siz < 5) {
	    fatal("Unexpected message on main input, message size %d less "
		  "than minimum.");
	}
	m->req_size = siz;
	m->next = NULL;
	if (!enque_mesq(mq, m)) {
	     fatal("Reader could not talk to main thread!");
	}
    }
}	

DWORD WINAPI writer(void *data) 
{
    MesQ *mq = (MesQ *) data;
    QueItem *m;
    HANDLE outp = GetStdHandle(STD_OUTPUT_HANDLE);
    AddrByte hdr[PACKET_BYTES];

    for (;;) {
	WaitForSingleObject(event_mesq(mq),INFINITE);
	if (!deque_mesq(mq, &m)) {
	    fatal("Writer could not talk to main thread!");
	}
	PUT_PACKET_BYTES(hdr, m->req_size);
	if (write_exact(outp, hdr, 4) != 4) {
	    DEBUGF(1,("Erlang has closed (writing)"));
	    exit(0);
	}
	if (write_exact(outp, m->request, m->req_size) != m->req_size) {
	    DEBUGF(1,("Erlang has closed (writing)"));
	    exit(0);
	}
	FREE(m);
    }
}


#else

static size_t read_int32(int fd, int *res)
{
    AddrByte b[4];
    int r;
    if ((r = read_exact(fd,b,4)) < 0) {
	return -1;
    } else if (r == 0) {
	return 0;
    } else {
	*res = (unsigned) b[3];
	*res |= ((unsigned) b[2]) << 8;
	*res |= ((unsigned) b[1]) << 16;
	*res |= ((unsigned) b[0]) << 24;
    }
    return 4;
}

static ssize_t read_exact(int fd, void *vbuff, size_t nbytes)
{
    ssize_t ret, got;
    char *buff = vbuff;

    got = 0;
    for(;;) {
	ret = read(fd, buff, nbytes - got);
	if (ret < 0) {
	    if (errno == EINTR) {
		continue;
	    } else {
		DEBUGF(1, ("Error while reading from pipe,"
			   " errno = %d",
			   errno));
		return -1;
	    }
	} else if (ret == 0) {
	    DEBUGF(1, ("End of file while reading from pipe."));
	    if (got == 0) {
		return 0; /* "Normal" EOF */
	    } else {
		return -1;
	    }
	} else if (ret < nbytes - got) {
	    got += ret;
	    buff += ret;
	} else {
	    return nbytes;
	}
    }
}

static int write_exact(int fd, AddrByte *buff, int len) 
{
    int res;
    int x = len;
    for(;;) {
	if((res = write(fd, buff, x)) == x) {
	    break;
	}
	if (res < 0) {
	    if (errno == EINTR) {
		continue;
	    } else if (errno == EPIPE) {
		return 0;
	    }
#ifdef ENXIO
	    else if (errno == ENXIO) {
		return 0;
	    }
#endif
	    else {
		return -1;
	    }
	} else {
	    /* Hmmm, blocking write but not all written, could this happen
	       if the other end was closed during the operation? Well, 
	       it costs very little to handle anyway... */
	    x -= res;
	    buff += res;
	}
    }
    return len;
}

#endif /* !WIN32 */

/*
 * Debug and memory allocation
 */

static char *format_address(int siz, AddrByte *addr)
{
    static char buff[50];
    char tmp[10];
    if (siz > 16) {
	return "(unknown)";
    }
    *buff='\0';
    if (siz <= 4) {
	while(siz--) {
	    sprintf(tmp,"%d",(int) *addr++);
	    strcat(buff,tmp);
	    if(siz) {
		strcat(buff,".");
	    }
	}
	return buff;
    } 
    while(siz--) {
	sprintf(tmp,"%02x",(int) *addr++);
	strcat(buff,tmp);
	if(siz) {
	    strcat(buff,":");
	}
    }
    return buff;
}

static void debugf(char *format, ...)
{
    char buff[2048];
    char *ptr;
    va_list ap;

    va_start(ap,format);
#ifdef WIN32
	sprintf(buff,"%s[%d] (DEBUG):",program_name,(int) GetCurrentThreadId());
#else
    sprintf(buff,"%s[%d] (DEBUG):",program_name,(int) getpid());
#endif
    ptr = buff + strlen(buff);
    vsprintf(ptr,format,ap);
    strcat(ptr,"\r\n");
#ifdef WIN32
    {
	DWORD res;
	WriteFile(GetStdHandle(STD_ERROR_HANDLE),buff,strlen(buff),&res,NULL);
    }
#else
    write(2,buff,strlen(buff));
#endif
    va_end(ap);
}

static void warning(char *format, ...)
{
    char buff[2048];
    char *ptr;
    va_list ap;

    va_start(ap,format);
    sprintf(buff,"%s[%d]: WARNING:",program_name, (int) getpid());
    ptr = buff + strlen(buff);
    vsprintf(ptr,format,ap);
    strcat(ptr,"\r\n");
#ifdef WIN32
    {
	DWORD res;
	WriteFile(GetStdHandle(STD_ERROR_HANDLE),buff,strlen(buff),&res,NULL);
    }
#else
    write(2,buff,strlen(buff));
#endif
    va_end(ap);
}

static void fatal(char *format, ...)
{
    char buff[2048];
    char *ptr;
    va_list ap;

    va_start(ap,format);
    sprintf(buff,"%s[%d]: FATAL ERROR:",program_name, (int) getpid());
    ptr = buff + strlen(buff);
    vsprintf(ptr,format,ap);
    strcat(ptr,"\r\n");
#ifdef WIN32
    {
	DWORD res;
	WriteFile(GetStdHandle(STD_ERROR_HANDLE),buff,strlen(buff),&res,NULL);
    }
#else
    write(2,buff,strlen(buff));
#endif
    va_end(ap);
#ifndef WIN32
    kill_all_workers();
#endif
    exit(1);
}

static void *my_malloc(size_t size)
{ 
    void *ptr = malloc(size);
    if (!ptr) {
	fatal("Cannot allocate %d bytes of memory.", (int) size);
	return NULL; /* lint... */
    }
    return ptr;
}

static void *my_realloc(void *old, size_t size)
{
    void *ptr = realloc(old, size);
    if (!ptr) {
	fatal("Cannot reallocate %d bytes of memory from 0x%08X.", 
	      (int) size, (unsigned) old);
	return NULL; /* lint... */
    }
    return ptr;
}

#ifdef WIN32

BOOL create_mesq(MesQ **q) 
{
    MesQ *tmp = malloc(sizeof(MesQ));
    tmp->data_present = CreateEvent(NULL, TRUE, FALSE,NULL);
    if (tmp->data_present == NULL) {
	free(tmp);
	return FALSE;
    }
    InitializeCriticalSection(&(tmp->crit)); /* Cannot fail */
    tmp->shutdown = 0;
    tmp->first = NULL;
    tmp->last = NULL;
    *q = tmp;
    return TRUE;
}

BOOL enque_mesq(MesQ *q, QueItem *m)
{
    EnterCriticalSection(&(q->crit));
    if (q->shutdown) {
	LeaveCriticalSection(&(q->crit));
	return FALSE;
    }
    if (q->last == NULL) {
	q->first = q->last = m;
    } else {
	q->last->next = m;
	q->last = m;
    }
    m->next = NULL;
    if (!SetEvent(q->data_present)) {
	fprintf(stderr,"Fatal: Unable to signal event in %s:%d, last error: %d\n",
		__FILE__,__LINE__,GetLastError());
	exit(1); /* Unable to continue at all */
    }
    LeaveCriticalSection(&(q->crit));
    return TRUE;
}

BOOL deque_mesq(MesQ *q, QueItem **m)
{
    EnterCriticalSection(&(q->crit));
    if (q->first == NULL) { /* Usually shutdown from other end */
	ResetEvent(q->data_present); 
	LeaveCriticalSection(&(q->crit));
	return FALSE;
    }
    *m = q->first;
    q->first = q->first->next;
    if (q->first == NULL) {
	q->last = NULL;
	ResetEvent(q->data_present);
    }
    (*m)->next = NULL;
    LeaveCriticalSection(&(q->crit));
    return TRUE;
}

BOOL close_mesq(MesQ *q)
{
    QueItem *tmp;
    EnterCriticalSection(&(q->crit));
    if (!q->shutdown) {
	q->shutdown = TRUE;
	if (!SetEvent(q->data_present)) {
	    fprintf(stderr,"Fatal: Unable to signal event in %s:%d, last error: %d\n",
		    __FILE__,__LINE__,GetLastError());
	    exit(1); /* Unable to continue at all */
	}
	LeaveCriticalSection(&(q->crit));
	return FALSE;
    }
    /* Noone else is supposed to use this object any more */
    LeaveCriticalSection(&(q->crit));
    DeleteCriticalSection(&(q->crit));
    CloseHandle(q->data_present);
    tmp = q->first;
    while(tmp) {
	q->first = q->first->next;
	free(tmp);
	tmp = q->first;
    }
    free(q);
    return TRUE;
}

HANDLE event_mesq(MesQ *q)
{
    return q->data_present;
}
    
#endif