[libvirt] [PATCH 02/18] Fix error detection in virStorageBackendISCSIGetHostNumber

[Ján Tomko]

In the unlikely case the iSCSI session path exists, but does not
contain an entry starting with "target", we would silently use
an initialized value.

Rewrite the function to correctly report errors.
---
 src/storage/storage_backend_iscsi.c | 38 +++++++++++++++++++------------------
 1 file changed, 20 insertions(+), 18 deletions(-)

diff --git a/src/storage/storage_backend_iscsi.c b/src/storage/storage_backend_iscsi.c
index bccfba3..876c14c 100644
--- a/src/storage/storage_backend_iscsi.c
+++ b/src/storage/storage_backend_iscsi.c
@@ -90,7 +90,7 @@ static int
 virStorageBackendISCSIGetHostNumber(const char *sysfs_path,
                                     uint32_t *host)
 {
-    int retval = 0;
+    int ret = -1;
     DIR *sysdir = NULL;
     struct dirent *dirent = NULL;
     int direrr;
@@ -104,26 +104,33 @@ virStorageBackendISCSIGetHostNumber(const char *sysfs_path,
     if (sysdir == NULL) {
         virReportSystemError(errno,
                              _("Failed to opendir path '%s'"), sysfs_path);
-        retval = -1;
-        goto out;
+        goto cleanup;
     }
 
     while ((direrr = virDirRead(sysdir, &dirent, sysfs_path)) > 0) {
         if (STREQLEN(dirent->d_name, "target", strlen("target"))) {
-            if (sscanf(dirent->d_name,
-                       "target%u:", host) != 1) {
-                VIR_DEBUG("Failed to parse target '%s'", dirent->d_name);
-                retval = -1;
-                break;
+            if (sscanf(dirent->d_name, "target%u:", host) == 1) {
+                ret = 0;
+                goto cleanup;
+            } else {
+                virReportError(VIR_ERR_INTERNAL_ERROR,
+                               _("Failed to parse target '%s'"), dirent->d_name);
+                goto cleanup;
             }
         }
     }
-    if (direrr < 0)
-        retval = -1;
 
+    if (direrr == 0) {
+        virReportSystemError(errno,
+                             _("Failed to get host number for iSCSI session "
+                               "with path '%s'"),
+                             sysfs_path);
+        goto cleanup;
+    }
+
+ cleanup:
     closedir(sysdir);
- out:
-    return retval;
+    return ret;
 }
 
 static int
@@ -138,13 +145,8 @@ virStorageBackendISCSIFindLUs(virStoragePoolObjPtr pool,
                     "/sys/class/iscsi_session/session%s/device", session) < 0)
         goto cleanup;
 
-    if (virStorageBackendISCSIGetHostNumber(sysfs_path, &host) < 0) {
-        virReportSystemError(errno,
-                             _("Failed to get host number for iSCSI session "
-                               "with path '%s'"),
-                             sysfs_path);
+    if (virStorageBackendISCSIGetHostNumber(sysfs_path, &host) < 0)
         goto cleanup;
-    }
 
     if (virStorageBackendSCSIFindLUs(pool, host) < 0)
         goto cleanup;
-- 
2.7.3