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

	} else {
	    fatal("Unexpected end of file on main input, errno = %d",errno);
	}
    }

    if (siz > *buff_size) {
	if (buff_size == 0) {
	    *buff = ALLOC((*buff_size = siz));
	} else {
	    *buff = REALLOC(*buff, (*buff_size = siz));
	}
    }
    if (read_exact(0,*buff, 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.");
    }
    return siz;
}

#endif /* !WIN32 */

static OpType get_op(AddrByte *buff)
{
    return (OpType) buff[4];
}

static AddrByte *get_op_addr(AddrByte *buff)
{
    return  buff + 4;
}

static SerialType get_serial(AddrByte *buff)
{
    return get_int32(buff);
}

static ProtoType get_proto(AddrByte *buff)
{
    return (ProtoType) buff[5];
}

static CtlType get_ctl(AddrByte *buff)
{
    return (CtlType) buff[5];
}

static AddrByte *get_data(AddrByte *buff)
{
    return buff + 6;
}

static int get_debug_level(AddrByte *buff)
{
    return get_int32(buff + 6);
}

#ifdef WIN32
static int send_mes_to_worker(QueItem *m, Worker *pw) 
{
    if (!enque_mesq(pw->writeto, m)) {
	warning("Unable to send to child process.");
	return -1;
    }
    return 0;
}
#else
static int send_request_to_worker(AddrByte *pr, int rsize, Worker *pw)    
{
    AddrByte hdr[PACKET_BYTES];

    PUT_PACKET_BYTES(hdr, rsize);
    if (write_exact(pw->writeto, hdr, PACKET_BYTES) < 0) { 
	warning("Unable to write to child process.");
	return -1;
    }
    if (write_exact(pw->writeto, (AddrByte *) pr, rsize) < 0) { 
	warning("Unable to write to child process.");
	return -1;
    }
    return 0;
}
#endif /* !WIN32 */

#ifdef WIN32
static int relay_reply(Worker *pw)
{
    QueItem *m;
    if (!deque_mesq(pw->readfrom,&m)) {
	return 0;
    }
    if (!enque_mesq(to_erlang,m)) {
	FREE(m);
	return 0;
    }
    return 1;
}

static int ignore_reply(Worker *pw) {
    QueItem *m;
    if (!deque_mesq(pw->readfrom,&m)) {
	return 0;
    }
    FREE(m);
    return 1;
}

#else

/* Static buffers used by the next three functions */
static AddrByte *relay_buff = NULL; 
static int relay_buff_size = 0;

static int fillin_reply(Worker *pw)
{
    int length;

    if (READ_PACKET_BYTES(pw->readfrom, &length) != PACKET_BYTES) {
	warning("Malformed reply (header) from worker process %d.", 
		pw->pid);
	return -1;
    }
    
    if (relay_buff_size < (length + PACKET_BYTES)) { 
	if (!relay_buff_size) {
	    relay_buff = 
		ALLOC((relay_buff_size = (length + PACKET_BYTES)));
	} else {
	    relay_buff = 
		REALLOC(relay_buff,
			(relay_buff_size = (length + PACKET_BYTES)));
	}
    }
    PUT_PACKET_BYTES(relay_buff, length);
    if (read_exact(pw->readfrom, relay_buff + PACKET_BYTES, length) != 
	length) {
	warning("Malformed reply (data) from worker process %d.", pw->pid);
	return -1;
    }
    return length;
}

static int relay_reply(Worker *pw)
{
    int length = fillin_reply(pw); /* Filled into the "global" buffer */
    int res;

    if (length < 0) {
	return -1;
    }
    if ((res = write_exact(1, relay_buff, length + PACKET_BYTES)) < 0) {
	fatal("Cannot write reply to erlang process, errno = %d.", errno);
    } else if (res == 0) {
	DEBUGF(1,("Erlang has closed write pipe."));
	return 0;
    }
    return length;
}

static int ignore_reply(Worker *pw)
{
    return fillin_reply(pw);
}

#endif /* !WIN32 */

/*
 * Domain name "parsing" and worker specific queing
 */
static void domaincopy(AddrByte *out, AddrByte *in)
{
    AddrByte *ptr = out; 
    *ptr++ = *in++;
    *ptr++ = *in++;
    switch(*out) {
    case OP_GETHOSTBYNAME:
	while(*in != '\0' && *in != '.')
	    ++in;
	strncpy((char*)ptr, (char*)in, DOMAINNAME_MAX-2);
	ptr[DOMAINNAME_MAX-3] = '\0';
	DEBUGF(4,("Saved domainname %s.", ptr));
	return;
    case OP_GETHOSTBYADDR:
	memcpy(ptr,in, ((out[1] == PROTO_IPV4) ? UNIT_IPV4 : UNIT_IPV6) - 1);
	DEBUGF(4, ("Saved domain address: %s.", 
		   format_address(((out[1] == PROTO_IPV4) ? 
				   UNIT_IPV4 : UNIT_IPV6) - 1,ptr)));
	return;
    default:
	fatal("Trying to copy buffer not containing valid domain, [%d,%d].",
	      (int) out[0], (int) out[1]);
    }
}

static int domaineq(AddrByte *d1, AddrByte *d2)
{
    if (d1[0] != d2[0] || d1[1] != d2[1]) {
	return 0;
    }
    switch (d1[0]) {
    case OP_GETHOSTBYNAME:
	return !strcmp((char*)d1+2,(char*)d2+2);
    case OP_GETHOSTBYADDR:
	return !memcmp(d1+2,d2+2, ((d1[1] == PROTO_IPV4) 
				   ? UNIT_IPV4 : UNIT_IPV6) - 1);
    default:
	fatal("Trying to compare buffers not containing valid domain, "
	      "[%d,%d].",
	      (int) d1[0], (int) d1[1]);
	return -1; /* Lint... */
    }
}
	    
static int get_domainname(AddrByte *inbuff, int insize, AddrByte *domainbuff)
{
    OpType op = get_op(inbuff);
    ProtoType proto;
    int i;
    AddrByte *data;

    data = get_data(inbuff);
    switch (op) {
    case OP_GETHOSTBYNAME:
	data = get_data(inbuff);
	for (i = (data - inbuff); i < insize && inbuff[i] != '\0'; ++i)
	    ;
	if (i < insize) {
	    domaincopy(domainbuff, get_op_addr(inbuff)); 
	    return 0;
	}
	DEBUGF(3, ("Could not pick valid domainname in "
		   "gethostbyname operation")); 
	return -1;
    case OP_GETHOSTBYADDR:
	proto = get_proto(inbuff);
	i = insize - (data - inbuff); 
	if ((proto == PROTO_IPV4 && i == UNIT_IPV4) || 
	    (proto == PROTO_IPV6 && i == UNIT_IPV6)) { 
	    /* An address buffer */
	    domaincopy(domainbuff, get_op_addr(inbuff));
	    return 0;
	}
	DEBUGF(3, ("Could not pick valid domainname in gethostbyaddr "
		   "operation")); 
	return -1;
    default:
	DEBUGF(2, ("Could not pick valid domainname because of "
		   "invalid opcode %d.", (int) op)); 
	return -1;
    }
}

/*
 * Worker subprocesses with utilities
 */
#ifdef WIN32
static int create_worker(Worker *pworker, int save_que)
{
    MesQ **thread_data = ALLOC(2*sizeof(MesQ *));
    DWORD tid;


    if (!create_mesq(thread_data)) {
	fatal("Could not create, pipes for subprocess, errno = %d",
		GetLastError());
    }
    if (!create_mesq(thread_data + 1)) {
	fatal("Could not create, pipes for subprocess, errno = %d",
		GetLastError());
    }
    /* Save those before the thread starts */
    pworker->writeto = thread_data[0];
    pworker->readfrom = thread_data[1];

    if (((HANDLE) _beginthreadex(NULL, 0, worker_loop, thread_data, 0, &tid))
	== NULL) {
	fatal("Could not create thread errno = %d",
	      GetLastError());
    }
    pworker->pid = tid;
    pworker->state = WORKER_FREE;
    pworker->serial = INVALID_SERIAL;
    if (!save_que) {
	pworker->que_first = pworker->que_last = NULL;
	pworker->que_size = 0;
    }
    DEBUGF(3,("Created worker[%ld] with fd %d", 
	      (long) pworker->pid, (int) pworker->readfrom));
    return 0;
}

#else

static int create_worker(Worker *pworker, int save_que)
{
    int p0[2], p1[2];
    pid_t child;

    if (pipe(p0)) {
	warning("Could not create, pipes for subprocess, errno = %d",
		errno);
	return -1;
    }

    if (pipe(p1)) {
	warning("Could not create, pipes for subprocess, errno = %d",
		errno);
	close(p0[0]);
	close(p0[1]);
	return -1;
    }
    if ((child = fork()) < 0) { /* failure */
	warning("Could not fork(), errno = %d",
		errno);
	close(p0[0]);
	close(p0[1]);
	close(p1[0]);
	close(p1[1]);
	return -1;
    } else if (child > 0) { /* parent */
	close(p0[1]);
	close(p1[0]);
	pworker->writeto = p1[1];
	pworker->readfrom = p0[0];
	pworker->pid = child;
	pworker->state = WORKER_FREE;
	pworker->serial = INVALID_SERIAL;
	if (!save_que) {
	    pworker->que_first = pworker->que_last = NULL;
	    pworker->que_size = 0;
	}
	DEBUGF(3,("Created worker[%ld] with fd %d", 
		  (long) pworker->pid, (int) pworker->readfrom));
	return 0;
    } else { /* child */
	close(p1[1]);
	close(p0[0]);
	close_all_worker_fds();
	/* Make "fatal" not find any children */
	num_busy_workers = num_free_workers = num_stalled_workers = 0;
	if((dup2(p1[0],0) < 0) || (dup2(p0[1],1) < 0)) {
	    fatal("Worker could not dup2(), errno = %d",
		  errno);
	    return -1; /* lint... */
	}
	close(p1[0]);
	close(p0[1]);
	signal(SIGCHLD, SIG_IGN); 
	return worker_loop();
    }
}

static void close_all_worker_fds(void) 
{
    int w,i;
    Worker *workers[3] = {free_workers, busy_workers, stalled_workers};
    int wsizes[3] = {num_free_workers, num_busy_workers,
		      num_stalled_workers};
    for (w = 0; w < 3; ++w) {
	for (i = 0; i < wsizes[w]; ++i) {
	    if (workers[w][i].state != WORKER_EMPTY) {
		close(workers[w][i].readfrom);
		close(workers[w][i].writeto);
	    }
	}
    }
}

#endif /* !WIN32 */

#ifdef WIN32
DWORD WINAPI worker_loop(void *v)
#else
static int worker_loop(void)
#endif
{
    struct hostent *he;
    AddrByte *req = NULL;
    size_t req_size = 0;
    int this_size;
    AddrByte *reply = NULL;
    size_t reply_size = 0;
    size_t data_size;
    int error_num;
    SerialType serial;
    OpType op;
    ProtoType proto;
    AddrByte *data;
    int free_he;
#ifdef WIN32
    QueItem *m = NULL;
    MesQ *readfrom = ((MesQ **) v)[0];
    MesQ *writeto = ((MesQ **) v)[1];
    FREE(v);
#endif

    for(;;) {
#ifdef WIN32
	WaitForSingleObject(event_mesq(readfrom),INFINITE);
	DEBUGF(4,("Worker got data on message que."));

	if(!deque_mesq(readfrom,&m)) {
	    goto fail;
	}
	this_size = m->req_size;
	req = m->request;
#else	
	if (READ_PACKET_BYTES(0,&this_size) != PACKET_BYTES) {
	    DEBUGF(2,("Worker got error/EOF while reading size, exiting."));
	    exit(0);
	}
	if (this_size > req_size) {
	    if (req == NULL) {
		req = ALLOC((req_size = this_size));
	    } else {
		req = REALLOC(req, (req_size = this_size));
	    }
	}
	if (read_exact(0, req, (size_t) this_size) != this_size) {
	    DEBUGF(1,("Worker got EOF while reading data, exiting."));
	    exit(0);
	}
#endif
	/* Decode the request... */
	serial = get_serial(req);
	if (OP_CONTROL == (op = get_op(req))) {
	    CtlType ctl;
	    if (serial != INVALID_SERIAL) {
		DEBUGF(1, ("Worker got invalid serial: %d.", serial));
		exit(0);
	    }
	    switch (ctl = get_ctl(req)) {
	    case SETOPT_DEBUG_LEVEL:
		debug_level = get_debug_level(req);
		DEBUGF(debug_level, 
		       ("Worker debug_level = %d.", debug_level));
		break;
	    }
	    continue;
	}
	proto = get_proto(req);
	data = get_data(req);
	DEBUGF(4,("Worker got request, op = %d, proto = %d, data = %s.",
		  op,proto,data));
	/* Got a request, lets go... */
	free_he = 0;
	switch (op) {
	case OP_GETHOSTBYNAME:
	    if (proto != PROTO_IPV4) {
#if defined(HAVE_GETIPNODEBYNAME) && !defined(WIN32) /* IP V6 support */
		if (proto == PROTO_IPV6) {
		    he = getipnodebyname(data, AF_INET6, AI_DEFAULT,
					 &error_num);
		    free_he = 1;
		    error_num = map_netdb_error(error_num);
		} else {
		    /* Not supported... */
		    he = NULL;
		    error_num = ERRCODE_NOTSUP;
		}		
#else
		/* Not supported... */
		he = NULL;
		error_num = ERRCODE_NOTSUP;
#endif
	    } else {
		DEBUGF(4,("Starting gethostbyname(%s)",data));
		he = gethostbyname((char*)data);
		error_num = he ? 0 : map_netdb_error(h_errno);
		if (error_num) {
		    DEBUGF(4,("gethostbyname(%s) gave error: %d", 
			      data, error_num));
		} else {
		    DEBUGF(4,("gethostbyname(%s) gave success",
			      data));
		}
	    }
	    if (!he) {
		data_size = build_error_reply(serial, error_num, 
					      &reply, &reply_size);
	    } else {
		data_size = build_reply(serial, he, &reply, &reply_size);
#if defined(HAVE_GETIPNODEBYNAME) && !defined(WIN32) /* IP V6 support */
		if (free_he) {
		    freehostent(he);
		}
#endif
	    }
	    break;
	case OP_GETHOSTBYADDR:
	    if (proto != PROTO_IPV4) {
#if defined(HAVE_GETIPNODEBYADDR) && !defined(WIN32) /* IP V6 support */
		if (proto == PROTO_IPV6) {
		    struct in6_addr ia;
		    memcpy(ia.s6_addr, data, 16);
		    he = getipnodebyaddr(&ia, 16, AF_INET6, &error_num);
		    free_he = 1;
		    error_num = map_netdb_error(error_num);
		} else {
		    /* Not supported... */
		    he = NULL;
		    error_num = ERRCODE_NOTSUP;
		}		
#else
		/* Not supported... */
		he = NULL;
		error_num = ERRCODE_NOTSUP;
#endif
	    } else {
		struct in_addr ia;
		memcpy(&ia.s_addr, data, 4); /* Alignment required... */
		he = gethostbyaddr((const char *) &ia, 4, AF_INET);
		error_num = map_netdb_error(h_errno);
	    }
	    if (!he) {
		data_size = build_error_reply(serial, error_num, 
					      &reply, &reply_size);
	    } else {
		data_size = build_reply(serial, he, &reply, &reply_size);
#if defined(HAVE_GETIPNODEBYADDR) && !defined(WIN32) /* IP V6 support */
		if (free_he) {
		    freehostent(he);
		}
#endif
	    }
	    break;
	default:
	    data_size = build_error_reply(serial, ERRCODE_NOTSUP, 
					  &reply, &reply_size);
	    break;
	}
#ifdef WIN32
	m = REALLOC(m, sizeof(QueItem) - 1 + data_size - PACKET_BYTES);
	m->next = NULL;
	m->req_size = data_size - PACKET_BYTES;
	memcpy(m->request,reply + PACKET_BYTES,data_size - PACKET_BYTES);
	if (!enque_mesq(writeto,m)) {
	    goto fail;
	}
	m = NULL;
#else
	write(1, reply, data_size); /* No signals expected */
#endif
    }
#ifdef WIN32
 fail:
    if (m != NULL) {
	FREE(m);
    }
    close_mesq(readfrom);
    close_mesq(writeto);
    if (reply) {
	FREE(reply);
    }
    return 1;
#endif
}

static int map_netdb_error(int netdb_code)
{
    switch (netdb_code) {
#ifdef HOST_NOT_FOUND
    case HOST_NOT_FOUND:
	return ERRCODE_HOST_NOT_FOUND;
#endif
#ifdef TRY_AGAIN
    case TRY_AGAIN:
	return ERRCODE_TRY_AGAIN;
#endif
#ifdef NO_RECOVERY
    case NO_RECOVERY:
	return ERRCODE_NO_RECOVERY;
#endif
#if defined(NO_DATA) || defined(NO_ADDRESS)
#ifdef NO_DATA
    case NO_DATA:
#endif
#ifdef NO_ADDRESS
#if !defined(NO_DATA) || (NO_DATA != NO_ADDRESS)