1 If getifaddrs blocks on a lock and a SIGALRM happens to fire while it

     2 is block, it will return with EINTR. WE need to detect that and just

     3 try again.

     4 

     5 This is NTP bug 2565. Remove this patch when upgrading to a version that

     6 has bug 2565 fixed in it.

     7 

     8 --- lib/isc/unix/ifiter_getifaddrs.c

     9 +++ lib/isc/unix/ifiter_getifaddrs.c

    10 @@ -55,6 +55,8 @@ isc_interfaceiter_create(isc_mem_t *mctx

    11  	isc_interfaceiter_t *iter;

    12  	isc_result_t result;

    13  	char strbuf[ISC_STRERRORSIZE];

    14 +	int trys;

    15 +	int ret;

    16  

    17  	REQUIRE(mctx != NULL);

    18  	REQUIRE(iterp != NULL);

    19 @@ -86,15 +88,21 @@ isc_interfaceiter_create(isc_mem_t *mctx

    20  	iter->valid = ISC_R_FAILURE;

    21  #endif

    22  

    23 -	if (getifaddrs(&iter->ifaddrs) < 0) {

    24 +	for (trys = 0; trys < 3; trys++) {

    25 +		if ((ret = getifaddrs(&iter->ifaddrs)) >= 0)

    26 +			break;

    27 +		if (errno != EINTR) 

    28 +			break;

    29 +	}

    30 +	if (ret < 0) {

    31  		isc__strerror(errno, strbuf, sizeof(strbuf));

    32  		UNEXPECTED_ERROR(__FILE__, __LINE__,

    33 -				 isc_msgcat_get(isc_msgcat,

    34 -						ISC_MSGSET_IFITERGETIFADDRS,

    35 -						ISC_MSG_GETIFADDRS,

    36 -						"getting interface "

    37 -						"addresses: getifaddrs: %s"),

    38 -				 strbuf);

    39 +		    isc_msgcat_get(isc_msgcat,

    40 +		    ISC_MSGSET_IFITERGETIFADDRS,

    41 +		    ISC_MSG_GETIFADDRS,

    42 +		    "getting interface "

    43 +		    "addresses: getifaddrs: %s"),

    44 +		    strbuf);

    45  		result = ISC_R_UNEXPECTED;

    46  		goto failure;

    47  	}