自学教程：C++ EI_TRACE_ERR0函数代码示例

/* stop the specified node */int ei_unpublish_tmo(const char *alive, unsigned ms){    char buf[EPMDBUF];    char *s = (char*)buf;    int len = 1 + strlen(alive);    int fd, res;    if (len > sizeof(buf)-3) {	erl_errno = ERANGE;	return -1;    }    put16be(s,len);    put8(s,EI_EPMD_STOP_REQ);    strcpy(s, alive);    /* FIXME can't connect, return success?! At least commen whats up */    if ((fd = ei_epmd_connect_tmo(NULL,ms)) < 0) return fd;    if ((res = ei_write_fill_t(fd, buf, len+2,ms)) != len+2) {	closesocket(fd);	erl_errno = (res == -2) ? ETIMEDOUT : EIO;	return -1;    }    EI_TRACE_CONN1("ei_unpublish_tmo","-> STOP %s",alive);      if ((res = ei_read_fill_t(fd, buf, 7, ms)) != 7) {	closesocket(fd);	erl_errno = (res == -2) ? ETIMEDOUT : EIO;	return -1;     }    closesocket(fd);    buf[7]=(char)0;		/* terminate the string */      if (!strcmp("STOPPED",(char *)buf)) {	EI_TRACE_CONN0("ei_unpublish_tmo","<- STOPPED (success)");	return 0;    }    else if (!strcmp("NOEXIST",(char *)buf)) {	EI_TRACE_ERR0("ei_unpublish_tmo","<- NOEXIST (failure)");	erl_errno = EIO;	return -1;    }    else {	EI_TRACE_ERR0("ei_unpublish_tmo","<- unknown (failure)");	erl_errno = EIO;	return -1;		/* this shouldn't happen */    }    return 0;}

static int initWinSock(void){    WORD wVersionRequested;      WSADATA wsaData;     int i;     static LONG volatile initialized = 0;        wVersionRequested = MAKEWORD(1, 1);     if (InterlockedCompareExchange((LPLONG) &initialized,1L,0L) == 0L) {	/* FIXME not terminate, just a message?! */	if ((i = WSAStartup(wVersionRequested, &wsaData))) {	    EI_TRACE_ERR1("ei_connect_init",			  "ERROR: can't initialize windows sockets: %d",i);	    initialized = 2L;	    return 0;	}		if (LOBYTE(wsaData.wVersion) != 1 || HIBYTE(wsaData.wVersion) != 1) { 	    EI_TRACE_ERR0("initWinSock","ERROR: this version of windows "			  "sockets not supported");	    WSACleanup(); 	    initialized = 2L;	    return 0;	}	initialized = 3L;    } else while (initialized < 2) {	SwitchToThread();    }    return (int) (initialized - 2);}

static int send_challenge_ack(int fd, unsigned char digest[16], unsigned ms) {    char *s;    char buf[DEFBUF_SIZ];    int siz = 2 + 1 + 16;    int res;    s = buf;        put16be(s,siz - 2);    put8(s, 'a');    memcpy(s, digest, 16);    if ((res = ei_write_fill_t(fd, buf, siz, ms)) != siz) {	EI_TRACE_ERR0("recv_challenge_reply",		      "-> SEND_CHALLENGE_ACK socket write failed");	erl_errno = (res == -2) ? ETIMEDOUT : EIO;	return -1;    }        if (ei_tracelevel >= 3) {	char buffer[33];	    	EI_TRACE_CONN1("recv_challenge_reply",		   "-> SEND_CHALLENGE_ACK (ok) digest = %s",hex((char *)digest,buffer));    }        return 0;}

static int send_status(int fd, char *status, unsigned ms){    char *buf, *s;    char dbuf[DEFBUF_SIZ];    int siz = strlen(status) + 1 + 2;    int res;    buf = (siz > DEFBUF_SIZ) ? malloc(siz) : dbuf;    if (!buf) {	erl_errno = ENOMEM;	return -1;    }    s = buf;    put16be(s,siz - 2);    put8(s, 's');    memcpy(s, status, strlen(status));    if ((res = ei_write_fill_t(fd, buf, siz, ms)) != siz) {	EI_TRACE_ERR0("send_status","-> SEND_STATUS socket write failed");	if (buf != dbuf)	    free(buf);	erl_errno = (res == -2) ? ETIMEDOUT : EIO;	return -1;    }    EI_TRACE_CONN1("send_status","-> SEND_STATUS (%s)",status);    if (buf != dbuf)	free(buf);    return 0;}

static int recv_challenge_reply (int fd, 				 unsigned our_challenge,				 char cookie[], 				 unsigned *her_challenge,				 unsigned ms){    char dbuf[DEFBUF_SIZ];    char *buf = dbuf;    int is_static = 1;    int buflen = DEFBUF_SIZ;    int rlen;    char *s;    char tag;    char her_digest[16], expected_digest[16];        erl_errno = EIO;		/* Default */    if ((rlen = read_2byte_package(fd, &buf, &buflen, &is_static, ms)) != 21) {	EI_TRACE_ERR1("recv_challenge_reply",		      "<- RECV_CHALLENGE_REPLY socket read failed (%d)",rlen);	goto error;    }        s = buf;    if ((tag = get8(s)) != 'r') {	EI_TRACE_ERR2("recv_challenge_reply",		      "<- RECV_CHALLENGE_REPLY incorrect tag, "		      "expected 'r' got '%c' (%u)",tag,tag);	goto error;    }    *her_challenge = get32be(s);    memcpy(her_digest, s, 16);    gen_digest(our_challenge, cookie, (unsigned char*)expected_digest);    if (memcmp(her_digest, expected_digest, 16)) {	EI_TRACE_ERR0("recv_challenge_reply",		      "<- RECV_CHALLENGE_REPLY authorization failure");	goto error;    }    if (!is_static)	free(buf);       if (ei_tracelevel >= 3) {	char buffer[33];	        EI_TRACE_CONN2("recv_challenge_reply",		   "<- RECV_CHALLENGE_REPLY (ok) challenge = %u, digest = %s",		   *her_challenge,hex(her_digest,buffer));    }    erl_errno = 0;    return 0;    error:    if (!is_static)	free(buf);    return -1;}

int ei_accept_tmo(ei_cnode* ec, int lfd, ErlConnect *conp, unsigned ms){    int fd;    struct sockaddr_in cli_addr;    int cli_addr_len=sizeof(struct sockaddr_in);    unsigned her_version, her_flags;    ErlConnect her_name;    erl_errno = EIO;		/* Default error code */    EI_TRACE_CONN0("ei_accept","<- ACCEPT waiting for connection");        if ((fd = ei_accept_t(lfd, (struct sockaddr*) &cli_addr, 	&cli_addr_len, ms )) < 0) {	EI_TRACE_ERR0("ei_accept","<- ACCEPT socket accept failed");	erl_errno = (fd == -2) ? ETIMEDOUT : EIO;	goto error;    }        EI_TRACE_CONN0("ei_accept","<- ACCEPT connected to remote");        if (recv_name(fd, &her_version, &her_flags, &her_name, ms)) {	EI_TRACE_ERR0("ei_accept","<- ACCEPT initial ident failed");	goto error;    }        if (her_version <= 4) {	EI_TRACE_ERR0("ei_accept","<- ACCEPT remote version not compatible");	goto error;    }    else {	unsigned our_challenge;	unsigned her_challenge;	unsigned char our_digest[16];		if (send_status(fd,"ok", ms))	    goto error;	our_challenge = gen_challenge();	if (send_challenge(fd, ec->thisnodename, 	    our_challenge, her_version, ms))	    goto error;	if (recv_challenge_reply(fd, our_challenge, 	    ec->ei_connect_cookie, 	    &her_challenge, ms))	    goto error;	gen_digest(her_challenge, ec->ei_connect_cookie, our_digest);	if (send_challenge_ack(fd, our_digest, ms))	    goto error;	put_ei_socket_info(fd, her_version, null_cookie, ec);    }    if (conp) 	*conp = her_name;        EI_TRACE_CONN1("ei_accept","<- ACCEPT (ok) remote = %s",her_name.nodename);    erl_errno = 0;		/* No error */    return fd;    error:    EI_TRACE_ERR0("ei_accept","<- ACCEPT failed");    closesocket(fd);    return ERL_ERROR;} /* ei_accept */

 /* ip_addr is now in network byte order   *  * first we have to get hold of the portnumber to  *  the node through epmd at that host   **/int ei_xconnect_tmo(ei_cnode* ec, Erl_IpAddr adr, char *alivename, unsigned ms){    struct in_addr *ip_addr=(struct in_addr *) adr;    int rport = 0; /*uint16 rport = 0;*/    int sockd;    int one = 1;    int dist = 0;    ErlConnect her_name;    unsigned her_flags, her_version;    erl_errno = EIO;		/* Default error code */        EI_TRACE_CONN1("ei_xconnect","-> CONNECT attempt to connect to %s",		   alivename);        if ((rport = ei_epmd_port_tmo(ip_addr,alivename,&dist, ms)) < 0) {	EI_TRACE_ERR0("ei_xconnect","-> CONNECT can't get remote port");	/* ei_epmd_port_tmo() has set erl_errno */	return ERL_NO_PORT;    }        /* we now have port number to enode, try to connect */    if((sockd = cnct((uint16)rport, ip_addr, sizeof(struct in_addr),ms)) < 0) {	EI_TRACE_ERR0("ei_xconnect","-> CONNECT socket connect failed");	/* cnct() has set erl_errno */	return ERL_CONNECT_FAIL;    }        EI_TRACE_CONN0("ei_xconnect","-> CONNECT connected to remote");    /* FIXME why connect before checking 'dist' output from ei_epmd_port() ?! */    if (dist <= 4) {	EI_TRACE_ERR0("ei_xconnect","-> CONNECT remote version not compatible");	goto error;    }    else {	unsigned our_challenge, her_challenge;	unsigned char our_digest[16];		if (send_name(sockd, ec->thisnodename, (unsigned) dist, ms))	    goto error;	if (recv_status(sockd, ms))	    goto error;	if (recv_challenge(sockd, &her_challenge, &her_version,	    &her_flags, &her_name, ms))	    goto error;	our_challenge = gen_challenge();	gen_digest(her_challenge, ec->ei_connect_cookie, our_digest);	if (send_challenge_reply(sockd, our_digest, our_challenge, ms))	    goto error;	if (recv_challenge_ack(sockd, our_challenge, 	    ec->ei_connect_cookie, ms))	    goto error;	put_ei_socket_info(sockd, dist, null_cookie, ec); /* FIXME check == 0 */    }        setsockopt(sockd, IPPROTO_TCP, TCP_NODELAY, (char *)&one, sizeof(one));    setsockopt(sockd, SOL_SOCKET, SO_KEEPALIVE, (char *)&one, sizeof(one));    EI_TRACE_CONN1("ei_xconnect","-> CONNECT (ok) remote = %s",alivename);        erl_errno = 0;    return sockd;    error:    EI_TRACE_ERR0("ei_xconnect","-> CONNECT failed");    closesocket(sockd);    return ERL_ERROR;} /* ei_xconnect */

  /*   * Set up a connection to a given Node, and   * interchange hand shake messages with it.  * Returns a valid file descriptor at success,  * otherwise a negative error code.*/int ei_connect_tmo(ei_cnode* ec, char *nodename, unsigned ms){    char *hostname, alivename[BUFSIZ];    struct hostent *hp;#if !defined (__WIN32__)     /* these are needed for the call to gethostbyname_r */    struct hostent host;    char buffer[1024];    int ei_h_errno;#endif /* !win32 */        /* extract the host and alive parts from nodename */    if (!(hostname = strchr(nodename,'@'))) {	EI_TRACE_ERR0("ei_connect","Node name has no @ in name");	return ERL_ERROR;    } else {	strncpy(alivename, nodename, hostname - nodename);	alivename[hostname - nodename] = 0x0;	hostname++;    }    #ifndef __WIN32__    hp = ei_gethostbyname_r(hostname,&host,buffer,1024,&ei_h_errno);    if (hp == NULL) {	char thishostname[EI_MAXHOSTNAMELEN+1];	if (gethostname(thishostname,EI_MAXHOSTNAMELEN) < 0) {	    EI_TRACE_ERR0("ei_connect_tmo",			  "Failed to get name of this host");	    erl_errno = EHOSTUNREACH;	    return ERL_ERROR;	} else {	    char *ct;	    /* We use a short node name */    	    if ((ct = strchr(thishostname, '.')) != NULL) *ct = '/0';	}	if (strcmp(hostname,thishostname) == 0)	    /* Both nodes on same standalone host, use loopback */	    hp = ei_gethostbyname_r("localhost",&host,buffer,1024,&ei_h_errno);	if (hp == NULL) {	    EI_TRACE_ERR2("ei_connect",			  "Can't find host for %s: %d/n",nodename,ei_h_errno);	    erl_errno = EHOSTUNREACH;	    return ERL_ERROR;	}    }#else /* __WIN32__ */    if ((hp = ei_gethostbyname(hostname)) == NULL) {	char thishostname[EI_MAXHOSTNAMELEN+1];	if (gethostname(thishostname,EI_MAXHOSTNAMELEN) < 0) {	    EI_TRACE_ERR1("ei_connect_tmo",			  "Failed to get name of this host: %d", 			  WSAGetLastError());	    erl_errno = EHOSTUNREACH;	    return ERL_ERROR;	} else {	    char *ct;	    /* We use a short node name */    	    if ((ct = strchr(thishostname, '.')) != NULL) *ct = '/0';	}	if (strcmp(hostname,thishostname) == 0)	    /* Both nodes on same standalone host, use loopback */	    hp = ei_gethostbyname("localhost");	if (hp == NULL) {	    char reason[1024];	    win32_error(reason,sizeof(reason));	    EI_TRACE_ERR2("ei_connect",			  "Can't find host for %s: %s",nodename,reason);	    erl_errno = EHOSTUNREACH;	    return ERL_ERROR;	}    }#endif /* win32 */    return ei_xconnect_tmo(ec, (Erl_IpAddr) *hp->h_addr_list, alivename, ms);} /* ei_connect */

/** Initialize by set: thishostname, thisalivename, * thisnodename and thisipaddr. At success return 0,* otherwise return -1.*/int ei_connect_init(ei_cnode* ec, const char* this_node_name,		    const char *cookie, short creation){    struct hostent *hp;    char thishostname[EI_MAXHOSTNAMELEN+1];    char thisnodename[MAXNODELEN+1];    char thisalivename[EI_MAXALIVELEN+1];#ifdef __WIN32__    if (!initWinSock()) {	EI_TRACE_ERR0("ei_connect_xinit","can't initiate winsock");	return ERL_ERROR;    }#endif /* win32 */#ifdef _REENTRANT    if (ei_sockets_lock == NULL) {	ei_sockets_lock = ei_mutex_create();    }#endif /* _REENTRANT */        if (gethostname(thishostname, EI_MAXHOSTNAMELEN) == -1) {#ifdef __WIN32__	EI_TRACE_ERR1("ei_connect_init","Failed to get host name: %d",		      WSAGetLastError());#else	EI_TRACE_ERR1("ei_connect_init","Failed to get host name: %d", errno);#endif /* win32 */	return ERL_ERROR;    }    if (this_node_name == NULL) {	sprintf(thisalivename, "c%d", (int) getpid());    } else if (strlen(this_node_name) >= sizeof(thisalivename)) {	EI_TRACE_ERR0("ei_connect_init","ERROR: this_node_name too long");	return ERL_ERROR;    } else {	strcpy(thisalivename, this_node_name);    }        if ((hp = ei_gethostbyname(thishostname)) == 0) {	/* Looking up IP given hostname fails. We must be on a standalone	   host so let's use loopback for communication instead. */	if ((hp = ei_gethostbyname("localhost")) == 0) {#ifdef __WIN32__	    char reason[1024];		    win32_error(reason,sizeof(reason));	    EI_TRACE_ERR2("ei_connect_init",			  "Can't get ip address for host %s: %s",			  thishostname, reason);#else	    EI_TRACE_ERR2("ei_connect_init",			  "Can't get ip address for host %s: %d",			  thishostname, h_errno);#endif /* win32 */	    return ERL_ERROR;	}    }    {	char* ct;	if (strcmp(hp->h_name, "localhost") == 0) {	    /* We use a short node name */    	    if ((ct = strchr(thishostname, '.')) != NULL) *ct = '/0';	    sprintf(thisnodename, "%[email
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