RESPONDERS: Allow increasing the file-descriptor limit

This patch will increase the file descriptor limit to 8k or the
limits.conf maximum, whichever is lesser.

https://fedorahosted.org/sssd/ticket/1197

4 files changed, 48 insertions, 0 deletions

diff --git a/src/responder/common/responder.h b/src/responder/common/responder.h
index 48678ff9..619ae46e 100644
--- a/src/responder/common/responder.h
+++ b/src/responder/common/responder.h
@@ -25,6 +25,7 @@
 #include <stdint.h>
 #include <sys/un.h>
 #include <pcre.h>
+#include <sys/resource.h>
 #include "config.h"
 #include "talloc.h"
 #include "tevent.h"
@@ -266,4 +267,6 @@ sss_dp_get_account_recv(TALLOC_CTX *mem_ctx,
 
 bool sss_utf8_check(const uint8_t *s, size_t n);
 
+void responder_set_fd_limit(rlim_t fd_limit);
+
 #endif /* __SSS_RESPONDER_H__ */
diff --git a/src/responder/common/responder_common.c b/src/responder/common/responder_common.c
index a48ac556..94a9fdb6 100644
--- a/src/responder/common/responder_common.c
+++ b/src/responder/common/responder_common.c
@@ -648,3 +648,39 @@ int responder_logrotate(DBusMessage *message,
 
     return monitor_common_pong(message, conn);
 }
+
+void responder_set_fd_limit(rlim_t fd_limit)
+{
+    struct rlimit current_limit, new_limit;
+    int limret;
+
+    /* First determine the maximum hard limit */
+    limret = getrlimit(RLIMIT_NOFILE, &current_limit);
+    if (limret == 0) {
+        DEBUG(SSSDBG_TRACE_INTERNAL,
+              ("Current fd limit: [%d]\n",
+               current_limit.rlim_cur));
+        /* Choose the lesser of the requested and the hard limit */
+        if (current_limit.rlim_max < fd_limit) {
+            new_limit.rlim_cur = current_limit.rlim_max;
+        } else {
+            new_limit.rlim_cur = fd_limit;
+        }
+        new_limit.rlim_max = current_limit.rlim_max;
+
+        limret = setrlimit(RLIMIT_NOFILE, &new_limit);
+        if (limret == 0) {
+            DEBUG(SSSDBG_CONF_SETTINGS,
+                  ("Maximum file descriptors set to [%d]\n",
+                   new_limit.rlim_cur));
+        } else {
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  ("Could not set new fd limits. Proceeding with [%d]\n",
+                   current_limit.rlim_cur));
+        }
+    } else {
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              ("Could not determine fd limits. "
+               "Proceeding with system values\n"));
+    }
+}
diff --git a/src/responder/nss/nsssrv.c b/src/responder/nss/nsssrv.c
index a85695b0..3c23f1bf 100644
--- a/src/responder/nss/nsssrv.c
+++ b/src/responder/nss/nsssrv.c
@@ -45,6 +45,7 @@
 #include "sbus/sbus_client.h"
 
 #define DEFAULT_PWFIELD "*"
+#define DEFAULT_NSS_FD_LIMIT 8192
 
 #define SHELL_REALLOC_INCREMENT 5
 #define SHELL_REALLOC_MAX       50
@@ -307,6 +308,9 @@ int nss_process_init(TALLOC_CTX *mem_ctx,
         return EIO;
     }
 
+    /* Set up file descriptor limits */
+    responder_set_fd_limit(DEFAULT_NSS_FD_LIMIT);
+
     DEBUG(1, ("NSS Initialization complete\n"));
 
     return EOK;
diff --git a/src/responder/pam/pamsrv.c b/src/responder/pam/pamsrv.c
index be459b11..2786fe4e 100644
--- a/src/responder/pam/pamsrv.c
+++ b/src/responder/pam/pamsrv.c
@@ -44,6 +44,8 @@
 #include "responder/pam/pamsrv.h"
 #include "responder/common/negcache.h"
 
+#define DEFAULT_PAM_FD_LIMIT 8192
+
 #define SSS_PAM_SBUS_SERVICE_VERSION 0x0001
 #define SSS_PAM_SBUS_SERVICE_NAME "pam"
 
@@ -183,6 +185,9 @@ static int pam_process_init(TALLOC_CTX *mem_ctx,
         goto done;
     }
 
+    /* Set up file descriptor limits */
+    responder_set_fd_limit(DEFAULT_PAM_FD_LIMIT);
+
     ret = EOK;
 
 done: