TOOLS: move memcache related functions to tools_mc_utils.c

The upcoming patches will link only users of this file with client libs,
so it's better to have it separate.

There is no functional change in this patch

1 files changed, 187 insertions, 0 deletions

diff --git a/src/tools/tools_mc_util.c b/src/tools/tools_mc_util.c
new file mode 100644
index 000000000..5348829eb
--- /dev/null
+++ b/src/tools/tools_mc_util.c
@@ -0,0 +1,187 @@
+/*
+   SSSD
+
+   tools_mc_util - interface to the memcache for userspace tools
+
+   Copyright (C) Red Hat                                        2013
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include <talloc.h>
+#include <fcntl.h>
+
+#include "util/util.h"
+#include "tools/tools_util.h"
+#include "util/mmap_cache.h"
+
+static errno_t sss_mc_set_recycled(int fd)
+{
+    uint32_t w = SSS_MC_HEADER_RECYCLED;
+    struct sss_mc_header h;
+    off_t offset;
+    off_t pos;
+    int ret;
+
+
+    offset = MC_PTR_DIFF(&h.status, &h);
+
+    pos = lseek(fd, offset, SEEK_SET);
+    if (pos == -1) {
+        /* What do we do now ? */
+        return errno;
+    }
+
+    errno = 0;
+    ret = sss_atomic_write_s(fd, (uint8_t *)&w, sizeof(h.status));
+    if (ret == -1) {
+        return errno;
+    }
+
+    if (ret != sizeof(h.status)) {
+        /* Write error */
+        return EIO;
+    }
+
+    return EOK;
+}
+
+errno_t sss_memcache_invalidate(const char *mc_filename)
+{
+    int mc_fd = -1;
+    errno_t ret;
+    errno_t pret;
+    useconds_t t = 50000;
+    int retries = 2;
+
+    if (!mc_filename) {
+        return EINVAL;
+    }
+
+    mc_fd = open(mc_filename, O_RDWR);
+    if (mc_fd == -1) {
+        ret = errno;
+        if (ret == ENOENT) {
+            DEBUG(SSSDBG_TRACE_FUNC,("Memory cache file %s "
+                  "does not exist.\n", mc_filename));
+            return EOK;
+        } else {
+            DEBUG(SSSDBG_CRIT_FAILURE, ("Unable to open file %s: %s\n",
+                  mc_filename, strerror(ret)));
+            return ret;
+        }
+    }
+
+    ret = sss_br_lock_file(mc_fd, 0, 1, retries, t);
+    if (ret == EACCES) {
+        DEBUG(SSSDBG_TRACE_FUNC,
+              ("File %s already locked by someone else.\n", mc_filename));
+        goto done;
+    } else if (ret != EOK) {
+       DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to lock file %s.\n", mc_filename));
+       goto done;
+    }
+    /* Mark the mc file as recycled. */
+    ret = sss_mc_set_recycled(mc_fd);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to mark memory cache file %s "
+              "as recycled.\n", mc_filename));
+        goto done;
+    }
+
+    ret = EOK;
+done:
+    if (mc_fd != -1) {
+        /* Closing the file also releases the lock */
+        close(mc_fd);
+
+        /* Only unlink the file if invalidation was succesful */
+        if (ret == EOK) {
+            pret = unlink(mc_filename);
+            if (pret == -1) {
+                DEBUG(SSSDBG_MINOR_FAILURE,
+                      ("Failed to unlink file %s. "
+                       "Will be unlinked later by sssd_nss.\n"));
+            }
+        }
+    }
+    return ret;
+}
+
+static int clear_fastcache(bool *sssd_nss_is_off)
+{
+    int ret;
+    ret = sss_memcache_invalidate(SSS_NSS_MCACHE_DIR"/passwd");
+    if (ret != EOK) {
+        if (ret == EACCES) {
+            *sssd_nss_is_off = false;
+            return EOK;
+        } else {
+            return ret;
+        }
+    }
+
+    ret = sss_memcache_invalidate(SSS_NSS_MCACHE_DIR"/group");
+    if (ret != EOK) {
+        if (ret == EACCES) {
+            *sssd_nss_is_off = false;
+            return EOK;
+        } else {
+            return ret;
+        }
+    }
+
+    *sssd_nss_is_off = true;
+    return EOK;
+}
+
+errno_t sss_memcache_clear_all(void)
+{
+    errno_t ret;
+    bool sssd_nss_is_off = false;
+    FILE *clear_mc_flag;
+
+    ret = clear_fastcache(&sssd_nss_is_off);
+    if (ret != EOK) {
+        DEBUG(SSSDBG_CRIT_FAILURE, ("Failed to clear caches.\n"));
+        return EIO;
+    }
+    if (!sssd_nss_is_off) {
+        /* sssd_nss is running -> signal monitor to invalidate fastcache */
+        clear_mc_flag = fopen(SSS_NSS_MCACHE_DIR"/"CLEAR_MC_FLAG, "w");
+        if (clear_mc_flag == NULL) {
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  ("Failed to create clear_mc_flag file. "
+                   "Memory cache will not be cleared.\n"));
+            return EIO;
+        }
+        ret = fclose(clear_mc_flag);
+        if (ret != 0) {
+            ret = errno;
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  ("Unable to close file descriptor: %s\n",
+                   strerror(ret)));
+            return EIO;
+        }
+        DEBUG(SSSDBG_TRACE_FUNC, ("Sending SIGHUP to monitor.\n"));
+        ret = signal_sssd(SIGHUP);
+        if (ret != EOK) {
+            DEBUG(SSSDBG_CRIT_FAILURE,
+                  ("Failed to send SIGHUP to monitor.\n"));
+            return EIO;
+        }
+    }
+
+    return EOK;
+}