On 08/12/2016 11:06 AM, Jakub Hrozek wrote:
On Thu, Aug 11, 2016 at 02:23:39PM +0200, Petr Cech wrote:
On 08/09/2016 02:49 PM, Jakub Hrozek wrote:
On Tue, Aug 09, 2016 at 12:57:58PM +0200, Petr Cech wrote:
On 08/09/2016 11:26 AM, Jakub Hrozek wrote:
On Mon, Aug 08, 2016 at 09:46:55AM +0200, Petr Cech wrote:
> On 08/04/2016 05:01 PM, Petr Cech wrote: >>> On 08/04/2016 04:35 PM, Petr Cech wrote: >>>>> Hi list, >>>>> >>>>> there is the first version of patch for [1]. I need >>>>> to investigate if we have the same issue in other >>>>> *_childs. >>>>> >>>>> I tested it with sleep() added into ldap_child code. >>>>> >>>>> [1] https://fedorahosted.org/sssd/ticket/3106 >>>>> >>> >>> I know, it is not perfect. For example 2 seconds between SIGTERM and >>> SIGKILL should be constant. I will send the second version with other >>> childs, but not today. >>> >>> Regards > > Hello all, > > there is fixed patch set. There is only one minor change -- constant for > time between signals. > > Is there better name for global_ccname_file_dummy? I did not want to break > the naming... but it looks really long.
I think this name is fine, but I would prefer to not use the variable in the code, except for setting it after the temporary file is created and then set the variable back to NULL after the temporary file is renamed to the real one.
Addressed.
Thanks Jakub, it looks better. :-)
OK, now I actually tested the patch and it regresses the way we handle responses, because the handler exits the process with success error code, the provider then tries to parse the child output, which is not there..
I think the easiest way would be to define a return code of ldap_child that would be used in exit in the signal handler and the back end code would print a nice debug message telling the admin that the child timed out.
Thanks Jakub, improved patch set is attached.
Regards
-- Petr^4 Čech
From f84d4d2fcc7c1f2cb404a02aeea7abd12c14dd61 Mon Sep 17 00:00:00 2001 From: Petr Cech pcech@redhat.com Date: Fri, 22 Jul 2016 14:28:54 +0200 Subject: [PATCH] LDAP: Fixing of removing netgroup from cache
This patch is from a different set.
Sorry, the right one is attached.
From 1f40587cbb256bab98e8e35670ca76426b41e6b1 Mon Sep 17 00:00:00 2001 From: Petr Cech pcech@redhat.com Date: Thu, 4 Aug 2016 16:27:40 +0200 Subject: [PATCH 2/3] LDAP: Adding SIGTERM signal before SIGKILL
We add better termination of ldap_child. If ldap_child reaches the timeout for termination parent sents SIGTERM signal. Child has 2 seconds for removing temporary file and exit. If it is not sufficient there is SIGKILL send to the child.
[...]
+static void get_tgt_timeout_handler(struct tevent_context *ev,
struct tevent_timer *te,
struct timeval tv, void *pvt)
+{
- struct tevent_req *req = talloc_get_type(pvt, struct tevent_req);
- struct sdap_get_tgt_state *state = tevent_req_data(req,
struct sdap_get_tgt_state);
- int ret;
- DEBUG(SSSDBG_TRACE_ALL,
"timeout for sending SIGTERM to tgt child [%d] reached.\n",
state->child->pid);
- ret = kill(state->child->pid, SIGTERM);
- if (ret == -1) {
Please use: ret = errno and then use ret instead of errno in the DEBUG statement to avoid overwriting errno if we ever change this branch in the future.
Thanks, addressed.
DEBUG(SSSDBG_CRIT_FAILURE,
"Sending SIGTERM failed [%d][%s].\n", errno, strerror(errno));
- }
From 4ca2a6b90dd7d7ee792b0e144a4e6d432f4693a4 Mon Sep 17 00:00:00 2001 From: Petr Cech pcech@redhat.com Date: Thu, 11 Aug 2016 14:18:15 +0200 Subject: [PATCH 3/3] LDAP: Adding SIGCHLD callback
This patch adds SIGCHLD callback for ldap_child. So if timeout is reached and ldap_child is terminated by handler we have debug message about it.
This patch does not apply for me, so I'll just comment on the diff.
I applied it on top of master. If there is some issue please tell me.
src/providers/ldap/ldap_child.c | 2 +- src/providers/ldap/sdap_child_helpers.c | 10 +++++++++- src/util/child_common.h | 1 + 3 files changed, 11 insertions(+), 2 deletions(-)
diff --git a/src/providers/ldap/ldap_child.c b/src/providers/ldap/ldap_child.c index 2edfc30ec7b4a3ff03d86ae41f086a6128451a9b..b6913fdaa4c8f87f33cc8c10f9a029d63626f279 100644 --- a/src/providers/ldap/ldap_child.c +++ b/src/providers/ldap/ldap_child.c @@ -54,7 +54,7 @@ static void sig_term_handler(int sig) } }
- _exit(0);
- _exit(SIGNAL_EXIT_CODE);
I would prefer CHILD_SIGTERM_EXIT_CODE or CHILD_TIMEOUT_EXIT_CODE (prefix and change the name)
Addressed. Naming is one big issue :-)
}
static krb5_context krb5_error_ctx; diff --git a/src/providers/ldap/sdap_child_helpers.c b/src/providers/ldap/sdap_child_helpers.c index 9f9c9b57a7ca5e1217d56ab560cc941432084df8..98b0fe777fd18fad6ffdaefc48ea156a45f4e803 100644 --- a/src/providers/ldap/sdap_child_helpers.c +++ b/src/providers/ldap/sdap_child_helpers.c @@ -69,6 +69,14 @@ static void sdap_close_fd(int *fd) *fd = -1; }
+void child_callback(int child_status, struct tevent_signal *sige, void *pvt) +{
- if (WEXITSTATUS(child_status) == SIGNAL_EXIT_CODE) {
DEBUG(SSSDBG_CRIT_FAILURE,
"LDAP child was terminated due to timeout\n");
- }
+}
static errno_t sdap_fork_child(struct tevent_context *ev, struct sdap_child *child) { @@ -110,7 +118,7 @@ static errno_t sdap_fork_child(struct tevent_context *ev, sss_fd_nonblocking(child->io->read_from_child_fd); sss_fd_nonblocking(child->io->write_to_child_fd);
ret = child_handler_setup(ev, pid, NULL, NULL, NULL);
ret = child_handler_setup(ev, pid, child_callback, NULL, NULL); if (ret != EOK) { goto fail; }
diff --git a/src/util/child_common.h b/src/util/child_common.h index eb7623987238d5d9e9032b9bbbbef49188f5b1d2..e88661349a1568ffc981e0a3134f7ccea61b394e 100644 --- a/src/util/child_common.h +++ b/src/util/child_common.h @@ -36,6 +36,7 @@ #define CHILD_MSG_CHUNK 256
#define SIGTERM_TO_SIGKILL_TIME 2 +#define SIGNAL_EXIT_CODE EINTR
I'm not sure if we want to use errno constants here, I would say just defining our own constant is better, at least to avoid overflowing the maximum exit value of 255. I don't think we even have to worry about clashing with constants from sysexits.h, this is our internal API anyway.
I choose 7.
Logs now look like:
[root@albireo sssd]# grep 'child' sssd_ipa.cygnus.dev.log [child_handler_setup] (0x2000): Setting up signal handler up for pid [18835] [child_handler_setup] (0x2000): Signal handler set up for pid [18835] [set_tgt_child_timeout] (0x0400): Setting 6 seconds timeout for tgt child
(6 seconds later)
[get_tgt_timeout_handler] (0x4000): timeout for sending SIGTERM to tgt child [18835] reached. [get_tgt_timeout_handler] (0x0400): Setting 2 seconds timeout for sending SIGKILL to tgt child [sdap_get_tgt_recv] (0x0020): Cannot parse child response: [22][Invalid argument] [sdap_kinit_done] (0x0020): child failed (22 [Invalid argument]) [child_sig_handler] (0x1000): Waiting for child [18835]. [child_sig_handler] (0x0020): child [18835] failed with status [7]. [child_callback] (0x0020): LDAP child was terminated due to timeout
Regards