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-rw-r--r--Makefile.am11
-rw-r--r--src/providers/child_common.c230
-rw-r--r--src/providers/child_common.h25
-rw-r--r--src/providers/data_provider_be.c9
-rw-r--r--src/providers/dp_backend.h2
5 files changed, 269 insertions, 8 deletions
diff --git a/Makefile.am b/Makefile.am
index a3eb05cc..7ebf29f4 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -461,6 +461,7 @@ sssd_sudo_LDADD = \
endif
sssd_be_SOURCES = \
+ src/providers/child_common.c \
src/providers/data_provider_be.c \
src/providers/data_provider_fo.c \
src/providers/data_provider_opts.c \
@@ -1028,7 +1029,9 @@ krb5_child_SOURCES = \
src/providers/child_common.c \
src/providers/dp_pam_data_util.c \
src/util/user_info_msg.c \
- src/util/sss_krb5.c
+ src/util/sss_krb5.c \
+ src/util/util.c \
+ src/util/signal.c
krb5_child_CFLAGS = \
$(AM_CFLAGS) \
$(POPT_CFLAGS) \
@@ -1038,12 +1041,15 @@ krb5_child_LDADD = \
$(TALLOC_LIBS) \
$(TEVENT_LIBS) \
$(POPT_LIBS) \
+ $(DHASH_LIBS) \
$(KRB5_LIBS)
ldap_child_SOURCES = \
src/providers/ldap/ldap_child.c \
src/providers/child_common.c \
- src/util/sss_krb5.c
+ src/util/sss_krb5.c \
+ src/util/util.c \
+ src/util/signal.c
ldap_child_CFLAGS = \
$(AM_CFLAGS) \
$(POPT_CFLAGS) \
@@ -1054,6 +1060,7 @@ ldap_child_LDADD = \
$(TEVENT_LIBS) \
$(POPT_LIBS) \
$(OPENLDAP_LIBS) \
+ $(DHASH_LIBS) \
$(KRB5_LIBS)
proxy_child_SOURCES = \
diff --git a/src/providers/child_common.c b/src/providers/child_common.c
index 5920ebc7..34602a41 100644
--- a/src/providers/child_common.c
+++ b/src/providers/child_common.c
@@ -33,7 +33,225 @@
#include "db/sysdb.h"
#include "providers/child_common.h"
+struct sss_sigchild_ctx {
+ struct tevent_context *ev;
+ hash_table_t *children;
+ int options;
+};
+
struct sss_child_ctx {
+ pid_t pid;
+ sss_child_fn_t cb;
+ void *pvt;
+ struct sss_sigchild_ctx *sigchld_ctx;
+};
+
+errno_t sss_sigchld_init(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ struct sss_sigchild_ctx **child_ctx)
+{
+ errno_t ret;
+ struct sss_sigchild_ctx *sigchld_ctx;
+ struct tevent_signal *tes;
+
+ sigchld_ctx = talloc_zero(mem_ctx, struct sss_sigchild_ctx);
+ if (!sigchld_ctx) {
+ DEBUG(0, ("fatal error initializing sss_sigchild_ctx\n"));
+ return ENOMEM;
+ }
+ sigchld_ctx->ev = ev;
+
+ ret = sss_hash_create(sigchld_ctx, 10, &sigchld_ctx->children);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_FATAL_FAILURE,
+ ("fatal error initializing children hash table: [%s]\n",
+ strerror(ret)));
+ talloc_free(sigchld_ctx);
+ return ret;
+ }
+
+ BlockSignals(false, SIGCHLD);
+ tes = tevent_add_signal(ev, sigchld_ctx, SIGCHLD, SA_SIGINFO,
+ sss_child_handler, sigchld_ctx);
+ if (tes == NULL) {
+ talloc_free(sigchld_ctx);
+ return EIO;
+ }
+
+ *child_ctx = sigchld_ctx;
+ return EOK;
+}
+
+static int sss_child_destructor(void *ptr)
+{
+ struct sss_child_ctx *child_ctx;
+ hash_key_t key;
+ int error;
+
+ child_ctx = talloc_get_type(ptr, struct sss_child_ctx);
+ key.type = HASH_KEY_ULONG;
+ key.ul = child_ctx->pid;
+
+ error = hash_delete(child_ctx->sigchld_ctx->children, &key);
+ if (error != HASH_SUCCESS && error != HASH_ERROR_KEY_NOT_FOUND) {
+ DEBUG(SSSDBG_TRACE_INTERNAL,
+ ("failed to delete child_ctx from hash table [%d]: %s\n",
+ error, hash_error_string(error)));
+ }
+
+ return 0;
+}
+
+errno_t sss_child_register(TALLOC_CTX *mem_ctx,
+ struct sss_sigchild_ctx *sigchld_ctx,
+ pid_t pid,
+ sss_child_fn_t cb,
+ void *pvt,
+ struct sss_child_ctx **child_ctx)
+{
+ struct sss_child_ctx *child;
+ hash_key_t key;
+ hash_value_t value;
+ int error;
+
+ child = talloc_zero(mem_ctx, struct sss_child_ctx);
+ if (child == NULL) {
+ return ENOMEM;
+ }
+
+ child->pid = pid;
+ child->cb = cb;
+ child->pvt = pvt;
+ child->sigchld_ctx = sigchld_ctx;
+
+ key.type = HASH_KEY_ULONG;
+ key.ul = pid;
+
+ value.type = HASH_VALUE_PTR;
+ value.ptr = child;
+
+ error = hash_enter(sigchld_ctx->children, &key, &value);
+ if (error != HASH_SUCCESS) {
+ talloc_free(child);
+ return ENOMEM;
+ }
+
+ talloc_set_destructor((TALLOC_CTX *) child, sss_child_destructor);
+
+ *child_ctx = child;
+ return EOK;
+}
+
+struct sss_child_cb_pvt {
+ struct sss_child_ctx *child_ctx;
+ int wait_status;
+};
+
+static void sss_child_invoke_cb(struct tevent_context *ev,
+ struct tevent_immediate *imm,
+ void *pvt)
+{
+ struct sss_child_cb_pvt *cb_pvt;
+ struct sss_child_ctx *child_ctx;
+ hash_key_t key;
+ int error;
+
+ cb_pvt = talloc_get_type(pvt, struct sss_child_cb_pvt);
+ child_ctx = cb_pvt->child_ctx;
+
+ key.type = HASH_KEY_ULONG;
+ key.ul = child_ctx->pid;
+
+ error = hash_delete(child_ctx->sigchld_ctx->children, &key);
+ if (error != HASH_SUCCESS && error != HASH_ERROR_KEY_NOT_FOUND) {
+ DEBUG(SSSDBG_OP_FAILURE,
+ ("failed to delete child_ctx from hash table [%d]: %s\n",
+ error, hash_error_string(error)));
+ }
+
+ if (child_ctx->cb) {
+ child_ctx->cb(child_ctx->pid, cb_pvt->wait_status, child_ctx->pvt);
+ }
+}
+
+void sss_child_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum,
+ int count,
+ void *siginfo,
+ void *private_data)
+{
+ struct sss_sigchild_ctx *sigchld_ctx;
+ struct tevent_immediate *imm;
+ struct sss_child_cb_pvt *invoke_pvt;
+ struct sss_child_ctx *child_ctx;
+ hash_key_t key;
+ hash_value_t value;
+ int error;
+ int wait_status;
+ pid_t pid;
+
+ sigchld_ctx = talloc_get_type(private_data, struct sss_sigchild_ctx);
+ key.type = HASH_KEY_ULONG;
+
+ do {
+ do {
+ errno = 0;
+ pid = waitpid(-1, &wait_status, WNOHANG | sigchld_ctx->options);
+ } while (pid == -1 && errno == EINTR);
+
+ if (pid == -1) {
+ DEBUG(SSSDBG_TRACE_INTERNAL,
+ ("waitpid failed [%d]: %s\n", errno, strerror(errno)));
+ return;
+ } else if (pid == 0) continue;
+
+ key.ul = pid;
+ error = hash_lookup(sigchld_ctx->children, &key, &value);
+ if (error == HASH_SUCCESS) {
+ child_ctx = talloc_get_type(value.ptr, struct sss_child_ctx);
+
+ imm = tevent_create_immediate(sigchld_ctx->ev);
+ if (imm == NULL) {
+ DEBUG(SSSDBG_CRIT_FAILURE,
+ ("Out of memory invoking SIGCHLD callback\n"));
+ return;
+ }
+
+ invoke_pvt = talloc_zero(child_ctx, struct sss_child_cb_pvt);
+ if (invoke_pvt == NULL) {
+ DEBUG(SSSDBG_CRIT_FAILURE,
+ ("out of memory invoking SIGCHLD callback\n"));
+ return;
+ }
+ invoke_pvt->child_ctx = child_ctx;
+ invoke_pvt->wait_status = wait_status;
+
+ tevent_schedule_immediate(imm, sigchld_ctx->ev,
+ sss_child_invoke_cb, invoke_pvt);
+ } else if (error == HASH_ERROR_KEY_NOT_FOUND) {
+ DEBUG(SSSDBG_TRACE_LIBS,
+ ("BUG: waitpid() returned [%d] but it was not in the table. "
+ "This could be due to a linked library creating processes "
+ "without registering them with the sigchld handler\n",
+ pid));
+ /* We will simply ignore this and return to the loop
+ * This will prevent a zombie, but may cause unexpected
+ * behavior in the code that was trying to handle this
+ * pid.
+ */
+ } else {
+ DEBUG(SSSDBG_OP_FAILURE,
+ ("SIGCHLD hash table error [%d]: %s\n",
+ error, hash_error_string(error)));
+ /* This is bad, but we should try to check for other
+ * children anyway, to avoid potential zombies.
+ */
+ }
+ } while (pid != 0);
+}
+
+struct sss_child_ctx_old {
struct tevent_signal *sige;
pid_t pid;
int child_status;
@@ -44,11 +262,11 @@ struct sss_child_ctx {
int child_handler_setup(struct tevent_context *ev, int pid,
sss_child_callback_t cb, void *pvt)
{
- struct sss_child_ctx *child_ctx;
+ struct sss_child_ctx_old *child_ctx;
DEBUG(8, ("Setting up signal handler up for pid [%d]\n", pid));
- child_ctx = talloc_zero(ev, struct sss_child_ctx);
+ child_ctx = talloc_zero(ev, struct sss_child_ctx_old);
if (child_ctx == NULL) {
return ENOMEM;
}
@@ -300,7 +518,7 @@ void child_sig_handler(struct tevent_context *ev,
int count, void *__siginfo, void *pvt)
{
int ret, err;
- struct sss_child_ctx *child_ctx;
+ struct sss_child_ctx_old *child_ctx;
struct tevent_immediate *imm;
if (count <= 0) {
@@ -308,7 +526,7 @@ void child_sig_handler(struct tevent_context *ev,
return;
}
- child_ctx = talloc_get_type(pvt, struct sss_child_ctx);
+ child_ctx = talloc_get_type(pvt, struct sss_child_ctx_old);
DEBUG(7, ("Waiting for child [%d].\n", child_ctx->pid));
errno = 0;
@@ -363,8 +581,8 @@ static void child_invoke_callback(struct tevent_context *ev,
struct tevent_immediate *imm,
void *pvt)
{
- struct sss_child_ctx *child_ctx =
- talloc_get_type(pvt, struct sss_child_ctx);
+ struct sss_child_ctx_old *child_ctx =
+ talloc_get_type(pvt, struct sss_child_ctx_old);
if (child_ctx->cb) {
child_ctx->cb(child_ctx->child_status, child_ctx->sige, child_ctx->pvt);
}
diff --git a/src/providers/child_common.h b/src/providers/child_common.h
index 22a77dbb..1e9f1b6c 100644
--- a/src/providers/child_common.h
+++ b/src/providers/child_common.h
@@ -45,6 +45,31 @@ struct io_buffer {
size_t size;
};
+/* COMMON SIGCHLD HANDLING */
+typedef void (*sss_child_fn_t)(int pid, int wait_status, void *pvt);
+
+struct sss_sigchild_ctx;
+struct sss_child_ctx;
+
+/* Create a new child context to manage callbacks */
+errno_t sss_sigchld_init(TALLOC_CTX *mem_ctx,
+ struct tevent_context *ev,
+ struct sss_sigchild_ctx **child_ctx);
+
+errno_t sss_child_register(TALLOC_CTX *mem_ctx,
+ struct sss_sigchild_ctx *sigchld_ctx,
+ pid_t pid,
+ sss_child_fn_t cb,
+ void *pvt,
+ struct sss_child_ctx **child_ctx);
+
+void sss_child_handler(struct tevent_context *ev,
+ struct tevent_signal *se,
+ int signum,
+ int count,
+ void *siginfo,
+ void *private_data);
+
/* Callback to be invoked when a sigchld handler is called.
* The tevent_signal * associated with the handler will be
* freed automatically when this function returns.
diff --git a/src/providers/data_provider_be.c b/src/providers/data_provider_be.c
index 2de986cc..fb4da87c 100644
--- a/src/providers/data_provider_be.c
+++ b/src/providers/data_provider_be.c
@@ -42,6 +42,7 @@
#include "sbus/sssd_dbus.h"
#include "providers/dp_backend.h"
#include "providers/fail_over.h"
+#include "providers/child_common.h"
#include "resolv/async_resolv.h"
#include "monitor/monitor_interfaces.h"
@@ -1334,6 +1335,14 @@ int be_process_init(TALLOC_CTX *mem_ctx,
return EIO;
}
+ ret = sss_sigchld_init(ctx, ctx->ev, &ctx->sigchld_ctx);
+ if (ret != EOK) {
+ DEBUG(SSSDBG_FATAL_FAILURE,
+ ("Could not initialize sigchld context: [%s]\n",
+ strerror(ret)));
+ return ret;
+ }
+
return EOK;
}
diff --git a/src/providers/dp_backend.h b/src/providers/dp_backend.h
index ef9fe0d4..3d1c6bf2 100644
--- a/src/providers/dp_backend.h
+++ b/src/providers/dp_backend.h
@@ -24,6 +24,7 @@
#include "providers/data_provider.h"
#include "providers/fail_over.h"
+#include "providers/child_common.h"
#include "db/sysdb.h"
/* a special token, if used in place of the hostname, denotes that real
@@ -94,6 +95,7 @@ struct be_ctx {
const char *identity;
const char *conf_path;
struct be_failover_ctx *be_fo;
+ struct sss_sigchild_ctx *sigchld_ctx;
/* Functions to be invoked when the
* backend goes online or offline
generated by cgit (git 2.34.1) at 2024-11-12 05:31:21 +0000