| Bug #69379 | MySQL clients return bogus errno for host-not-found errors on Ubuntu 13.04 | ||
|---|---|---|---|
| Submitted: | 2 Jun 2013 8:00 | Modified: | 3 Jun 2013 15:15 |
| Reporter: | Laurynas Biveinis (OCA) | Email Updates: | |
| Status: | Verified | Impact on me: | |
| Category: | MySQL Server: Errors | Severity: | S3 (Non-critical) |
| Version: | 5.1 | OS: | Linux (Ubuntu 13.04) |
| Assigned to: | CPU Architecture: | Any | |
| Tags: | client, errno, gethostbyname_r, my_gethostbyname_r | ||
| Triage: | Needs Triage: D4 (Minor) | ||
[2 Jun 2013 8:00]
Laurynas Biveinis
[2 Jun 2013 8:54]
Laurynas Biveinis
It appears that there are two issues. 1) gethostbyname_r returning -1 in h_errno, as described above If this is fixed to copy errno to h_errno in my_gethostbyname_r(), then the following testcase failure still remains: The commands reported in the bug report -ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'cyril has found a bug :)XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' (errno) +ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'cyril has found a bug :)XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' (-1) Too long dbname ERROR 1102 (42000) at line 1: Incorrect database name 'test_really_long_dbnamexxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx' Too long hostname -ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'cyrils_superlonghostnameXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' (errno) +ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'cyrils_superlonghostnameXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' (-1) 1 Thus, 2) this appears to be caused by gethostbyname_r returning 0 (success), but setting hostent *result to NULL.
[2 Jun 2013 9:00]
Laurynas Biveinis
The following fixes the testsuite failures for me. I have no idea whether that's really correct, as I was not find info under what circumstances gethostbyname_r returns such values. Also the *h_errno = errno copying makes the my_gethostbyname_r() interface deviate from the underlying gethostbyname_r() interface, which is also suboptimal I guess.
This appears to be a 5.1-only issue BTW.
=== modified file 'mysys/my_net.c'
--- mysys/my_net.c 2013-03-19 12:29:12 +0000
+++ mysys/my_net.c 2013-06-02 08:56:24 +0000
@@ -60,9 +60,15 @@
int buflen, int *h_errnop)
{
struct hostent *hp;
+ int result_hostent;
DBUG_ASSERT((size_t) buflen >= sizeof(*result));
- if (gethostbyname_r(name,result, buffer, (size_t) buflen, &hp, h_errnop))
+ result_hostent= gethostbyname_r(name,result, buffer, (size_t) buflen, &hp, h_errnop);
+ if (unlikely(!result_hostent || !hp)) {
+ if (*h_errnop == NETDB_INTERNAL) {
+ *h_errnop= errno;
+ }
return 0;
+ }
return hp;
}
[2 Jun 2013 9:07]
Laurynas Biveinis
Editing the title to show the user, not testsuite/developer impact.
[2 Jun 2013 10:33]
Laurynas Biveinis
Inverted error condition typo in the suggested fix :( Also renamed the return value variable for gethostbyname_r to something more reasonable.
@@ -60,9 +60,15 @@
int buflen, int *h_errnop)
{
struct hostent *hp;
+ int ret;
DBUG_ASSERT((size_t) buflen >= sizeof(*result));
- if (gethostbyname_r(name,result, buffer, (size_t) buflen, &hp, h_errnop))
+ ret= gethostbyname_r(name,result, buffer, (size_t) buflen, &hp, h_errnop);
+ if (unlikely(ret || !hp)) {
+ if (*h_errnop == NETDB_INTERNAL) {
+ *h_errnop= errno;
+ }
return 0;
+ }
return hp;
}
[3 Jun 2013 12:58]
Miguel Solorzano
Not repeatable on CenTOS 6.4 X86_64 with revno 4017: ============================================================================= TEST RESULT TIME (ms) ------------------------------------------------------------ worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009 main.mysql [ pass ] 29641 i_main.mysql [ pass ] 72 ------------------------------------------------------------ The servers were restarted 0 times Spent 29.713 of 31 seconds executing testcases Completed: All 2 tests were successful. [miguel@tikal mysql-test]$ ./mysql-test-run --mem mysql_upgrade Logging: ./mysql-test-run --mem mysql_upgrade 130603 9:23:33 [Note] Plugin 'FEDERATED' is disabled. MySQL Version 5.1.71 Checking supported features... - skipping ndbcluster - SSL connections supported - binaries are debug compiled Collecting tests... vardir: /home/miguel/temp/mysql-5.1/mysql-test/var Checking leftover processes... Removing old var directory... Creating var directory '/home/miguel/temp/mysql-5.1/mysql-test/var'... - symlinking 'var' to '/dev/shm/var_auto_wHMb' Installing system database... Using server port 34534 ============================================================================== TEST RESULT TIME (ms) ------------------------------------------------------------ worker[1] Using MTR_BUILD_THREAD 300, with reserved ports 13000..13009 main.mysql_upgrade [ pass ] 13458 ------------------------------------------------------------ The servers were restarted 0 times Spent 13.458 of 14 seconds executing testcases Completed: All 1 tests were successful. [miguel@tikal mysql-test]$
[3 Jun 2013 13:00]
Laurynas Biveinis
Yes, for some reason (glibc version?) this is Ubuntu 13.04-specific. We haven't seen this on any other Linux distribution or any other Ubuntu version.
[3 Jun 2013 15:15]
Miguel Solorzano
Thank you for the feedback. Indeed only repeatable on Ubuntu 13.04: Too long hostname -ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'cyrils_superlonghostnameXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' (errno) +ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'cyrils_superlonghostnameXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX' (-1) 1 1 ERROR at line 1: DELIMITER cannot contain a backslash character @@ -198,7 +198,7 @@ 1 COUNT (*) 1 -ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'invalid_hostname' (errno) +ERROR 2005 (HY000) at line 1: Unknown MySQL server host 'invalid_hostname' (-1) End of 5.0 tests WARNING: --server-arg option not supported in this configuration. Warning (Code 1286): Unknown table engine 'nonexistent' mysqltest: Result content mismatch - saving '/home/miguel/mysql-5.1/mysql-test/var/log/main.mysql/' to '/home/miguel/mysql-5.1/mysql-test/var/log/main.mysql/' Only 1 of 2 completed. mysql-test-run: *** ERROR: Not all tests completed miguel@miguel:~/mysql-5.1/mysql-test$ cat /etc/issue Ubuntu 13.04 \n \l miguel@miguel:~/mysql-5.1/mysql-test$
