This patch moves reading of the upcall information from the child thread
into the main thread. It removes the need to synchronize between the
parent and child thread before processing upcall. Also it creates the thread
in a detached state.
Signed-off-by: Olga Kornievskaia <kolga@xxxxxxxxxx>
---
utils/gssd/gssd.c | 95 +++++++++++++++++++++++++++++++++++---------------
utils/gssd/gssd.h | 13 +++++--
utils/gssd/gssd_proc.c | 73 +++++++++++---------------------------
3 files changed, 98 insertions(+), 83 deletions(-)
diff --git a/utils/gssd/gssd.c b/utils/gssd/gssd.c
index 9bf7917..95b6715 100644
--- a/utils/gssd/gssd.c
+++ b/utils/gssd/gssd.c
@@ -363,54 +363,93 @@ gssd_destroy_client(struct clnt_info *clp)
static void gssd_scan(void);
-static inline void
-wait_for_child_and_detach(pthread_t th)
+static void
+start_upcall_thread(void (*func)(struct clnt_upcall_info *), void *info)
+{
+ pthread_attr_t attr;
+ pthread_t th;
+ int ret;
+
+ ret = pthread_attr_init(&attr);
+ if (ret != 0) {
+ printerr(0, "ERROR: failed to init pthread attr: ret %d: %s\n",
+ ret, strerror(errno));
+ goto err;
+ }
+ ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
+ if (ret != 0) {
+ printerr(0, "ERROR: failed to create pthread attr: ret %d: "
+ "%s\n", ret, strerror(errno));
+ goto err;
+ }
+
+ ret = pthread_create(&th, &attr, (void *)func, (void *)info);
+ if (ret != 0) {
+ printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
+ ret, strerror(errno));
+ goto err;
+ }
+ return;
+err:
+ free(info);
+}
+
+static struct clnt_upcall_info *alloc_upcall_info(struct clnt_info *clp)
{
- pthread_mutex_lock(&pmutex);
- while (!thread_started)
- pthread_cond_wait(&pcond, &pmutex);
- thread_started = false;
- pthread_mutex_unlock(&pmutex);
- pthread_detach(th);
+ struct clnt_upcall_info *info;
+
+ info = malloc(sizeof(struct clnt_upcall_info));
+ if (info == NULL)
+ return NULL;
+ info->clp = clp;
+
+ return info;
}
-/* For each upcall create a thread, detach from the main process so that
- * resources are released back into the system without the need for a join.
- * We need to wait for the child thread to start and consume the event from
- * the file descriptor.
+/* For each upcall read the upcall info into the buffer, then create a
+ * thread in a detached state so that resources are released back into
+ * the system without the need for a join.
*/
static void
gssd_clnt_gssd_cb(int UNUSED(fd), short UNUSED(which), void *data)
{
struct clnt_info *clp = data;
- pthread_t th;
- int ret;
+ struct clnt_upcall_info *info;
- ret = pthread_create(&th, NULL, (void *)handle_gssd_upcall,
- (void *)clp);
- if (ret != 0) {
- printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
- ret, strerror(errno));
+ info = alloc_upcall_info(clp);
+ if (info == NULL)
+ return;
+
+ info->lbuflen = read(clp->gssd_fd, info->lbuf, sizeof(info->lbuf));
+ if (info->lbuflen <= 0 || info->lbuf[info->lbuflen-1] != '\n') {
+ printerr(0, "WARNING: %s: failed reading request\n", __func__);
+ free(info);
return;
}
- wait_for_child_and_detach(th);
+ info->lbuf[info->lbuflen-1] = 0;
+
+ start_upcall_thread(handle_gssd_upcall, info);
}
static void
gssd_clnt_krb5_cb(int UNUSED(fd), short UNUSED(which), void *data)
{
struct clnt_info *clp = data;
- pthread_t th;
- int ret;
+ struct clnt_upcall_info *info;
- ret = pthread_create(&th, NULL, (void *)handle_krb5_upcall,
- (void *)clp);
- if (ret != 0) {
- printerr(0, "ERROR: pthread_create failed: ret %d: %s\n",
- ret, strerror(errno));
+ info = alloc_upcall_info(clp);
+ if (info == NULL)
+ return;
+
+ if (read(clp->krb5_fd, &info->uid,
+ sizeof(info->uid)) < (ssize_t)sizeof(info->uid)) {
+ printerr(0, "WARNING: %s: failed reading uid from krb5 "
+ "upcall pipe: %s\n", __func__, strerror(errno));
+ free(info);
return;
}
- wait_for_child_and_detach(th);
+
+ start_upcall_thread(handle_krb5_upcall, info);
}
static struct clnt_info *
diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h
index 565bce3..f4f5975 100644
--- a/utils/gssd/gssd.h
+++ b/utils/gssd/gssd.h
@@ -49,7 +49,7 @@
#define GSSD_DEFAULT_MACHINE_CRED_SUFFIX "machine"
#define GSSD_DEFAULT_KEYTAB_FILE "/etc/krb5.keytab"
#define GSSD_SERVICE_NAME "nfs"
-
+#define RPC_CHAN_BUF_SIZE 32768
/*
* The gss mechanisms that we can handle
*/
@@ -85,8 +85,15 @@ struct clnt_info {
struct sockaddr_storage addr;
};
-void handle_krb5_upcall(struct clnt_info *clp);
-void handle_gssd_upcall(struct clnt_info *clp);
+struct clnt_upcall_info {
+ struct clnt_info *clp;
+ char lbuf[RPC_CHAN_BUF_SIZE];
+ int lbuflen;
+ uid_t uid;
+};
+
+void handle_krb5_upcall(struct clnt_upcall_info *clp);
+void handle_gssd_upcall(struct clnt_upcall_info *clp);
#endif /* _RPC_GSSD_H_ */
diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c
index afaaf9e..d74d372 100644
--- a/utils/gssd/gssd_proc.c
+++ b/utils/gssd/gssd_proc.c
@@ -79,7 +79,6 @@
#include "nfsrpc.h"
#include "nfslib.h"
#include "gss_names.h"
-#include "misc.h"
/* Encryption types supported by the kernel rpcsec_gss code */
int num_krb5_enctypes = 0;
@@ -708,45 +707,22 @@ out_return_error:
goto out;
}
-/* signal to the parent thread that we have read from the file descriptor.
- * it should allow the parent to proceed to poll on the descriptor for
- * the next upcall from the kernel.
- */
-static inline void
-signal_parent_event_consumed(void)
-{
- pthread_mutex_lock(&pmutex);
- thread_started = true;
- pthread_cond_signal(&pcond);
- pthread_mutex_unlock(&pmutex);
-}
-
void
-handle_krb5_upcall(struct clnt_info *clp)
+handle_krb5_upcall(struct clnt_upcall_info *info)
{
- uid_t uid;
- int status;
+ struct clnt_info *clp = info->clp;
- status = read(clp->krb5_fd, &uid, sizeof(uid)) < (ssize_t)sizeof(uid);
- signal_parent_event_consumed();
+ printerr(2, "\n%s: uid %d (%s)\n", __func__, info->uid, clp->relpath);
- if (status) {
- printerr(0, "WARNING: failed reading uid from krb5 "
- "upcall pipe: %s\n", strerror(errno));
- return;
- }
-
- printerr(2, "\n%s: uid %d (%s)\n", __func__, uid, clp->relpath);
-
- process_krb5_upcall(clp, uid, clp->krb5_fd, NULL, NULL);
+ process_krb5_upcall(clp, info->uid, clp->krb5_fd, NULL, NULL);
+ free(info);
}
void
-handle_gssd_upcall(struct clnt_info *clp)
+handle_gssd_upcall(struct clnt_upcall_info *info)
{
+ struct clnt_info *clp = info->clp;
uid_t uid;
- char lbuf[RPC_CHAN_BUF_SIZE];
- int lbuflen = 0;
char *p;
char *mech = NULL;
char *uidstr = NULL;
@@ -754,19 +730,9 @@ handle_gssd_upcall(struct clnt_info *clp)
char *service = NULL;
char *enctypes = NULL;
- lbuflen = read(clp->gssd_fd, lbuf, sizeof(lbuf));
- signal_parent_event_consumed();
+ printerr(2, "\n%s: '%s' (%s)\n", __func__, info->lbuf, clp->relpath);
- if (lbuflen <= 0 || lbuf[lbuflen-1] != '\n') {
- printerr(0, "WARNING: handle_gssd_upcall: "
- "failed reading request\n");
- return;
- }
- lbuf[lbuflen-1] = 0;
-
- printerr(2, "\n%s: '%s' (%s)\n", __func__, lbuf, clp->relpath);
-
- for (p = strtok(lbuf, " "); p; p = strtok(NULL, " ")) {
+ for (p = strtok(info->lbuf, " "); p; p = strtok(NULL, " ")) {
if (!strncmp(p, "mech=", strlen("mech=")))
mech = p + strlen("mech=");
else if (!strncmp(p, "uid=", strlen("uid=")))
@@ -782,8 +748,8 @@ handle_gssd_upcall(struct clnt_info *clp)
if (!mech || strlen(mech) < 1) {
printerr(0, "WARNING: handle_gssd_upcall: "
"failed to find gss mechanism name "
- "in upcall string '%s'\n", lbuf);
- return;
+ "in upcall string '%s'\n", info->lbuf);
+ goto out;
}
if (uidstr) {
@@ -795,21 +761,21 @@ handle_gssd_upcall(struct clnt_info *clp)
if (!uidstr) {
printerr(0, "WARNING: handle_gssd_upcall: "
"failed to find uid "
- "in upcall string '%s'\n", lbuf);
- return;
+ "in upcall string '%s'\n", info->lbuf);
+ goto out;
}
if (enctypes && parse_enctypes(enctypes) != 0) {
printerr(0, "WARNING: handle_gssd_upcall: "
"parsing encryption types failed: errno %d\n", errno);
- return;
+ goto out;
}
if (target && strlen(target) < 1) {
printerr(0, "WARNING: handle_gssd_upcall: "
"failed to parse target name "
- "in upcall string '%s'\n", lbuf);
- return;
+ "in upcall string '%s'\n", info->lbuf);
+ goto out;
}
/*
@@ -823,8 +789,8 @@ handle_gssd_upcall(struct clnt_info *clp)
if (service && strlen(service) < 1) {
printerr(0, "WARNING: handle_gssd_upcall: "
"failed to parse service type "
- "in upcall string '%s'\n", lbuf);
- return;
+ "in upcall string '%s'\n", info->lbuf);
+ goto out;
}
if (strcmp(mech, "krb5") == 0 && clp->servername)
@@ -835,5 +801,8 @@ handle_gssd_upcall(struct clnt_info *clp)
"received unknown gss mech '%s'\n", mech);
do_error_downcall(clp->gssd_fd, uid, -EACCES);
}
+out:
+ free(info);
+ return;
}
--
1.8.3.1
--
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