update: Consolidate out-of-memory error paths. Minor code cleanups.

There are couple of places in update_db() where we can get
memory allocation failures. Consolidate such error handling
in single place and make code more readable.

Check for oom from call to g_strdup_printf() in update_db().

Allocate database directory and update file paths at the
beginning of the update procedure, so oom conditions
catched before we attempt to establish lock or create
update dot file.

Move code checking for valid file descriptor from update_end()
up to the caller.

Signed-off-by: Sergey Popovich <[email protected]>

src/update.c

@@ -124,11 +124,9 @@ static inline int update_begin(const char *update_fname)
 
 static inline void update_end(int fd, const char *update_fname, bool ok)
 {
-        if (fd != -1) {
-                close(fd);
-                if (ok)
-                        unlink(update_fname);
-        }
+        close(fd);
+        if (ok)
+                unlink(update_fname);
 }
 
 int update_required(const gchar *db_file)
@@ -147,18 +145,20 @@ bool update_db(bool quiet, const gchar *db_file)
         int year;
         bool ret = false;
         bool db_exist = false;
-        bool db_locked;
+        bool db_locked = false;
 
         u_fname = get_db_dot_fname(db_file, UPDATE_DB_FNAME_SUFFIX);
-        if (!u_fname) {
-                fputs("update_db(): Out of memory\n", stderr);
-                goto end_no_lock;
-        }
+        if (!u_fname)
+                goto oom;
+
+        db_dir = g_path_get_dirname(db_file);
+        if (!db_dir)
+                goto oom;
 
         db_locked = cve_db_write_lock(LOCK_WAIT_SECS);
         if (!db_locked) {
                 fputs("Exiting...\n", stderr);
-                goto end_no_lock;
+                goto end;
         }
 
         /* Lock aquired, check if database is still needs update */
@@ -167,12 +167,6 @@ bool update_db(bool quiet, const gchar *db_file)
                 goto end;
         }
 
-        db_dir = g_path_get_dirname(db_file);
-        if (!db_dir) {
-                fprintf(stderr, "update_db(): Out of memory\n");
-                goto end;
-        }
-
         u_handle = update_begin(u_fname);
         if (u_handle == -1) {
                 fprintf(stderr, "Can't create timestamp file %s\n", u_fname);
@@ -206,7 +200,12 @@ bool update_db(bool quiet, const gchar *db_file)
                 }
 
                 uri = g_strdup_printf("%s/%s", nvd_uri, nvdcve);
+                if (!uri)
+                        goto oom;
+
                 target = g_build_path(G_DIR_SEPARATOR_S, db_dir, nvdcve, NULL);
+                if (!target)
+                        goto oom;
 
                 st = fetch_uri(uri, target, !quiet);
                 switch (st) {
@@ -248,10 +247,14 @@ bool update_db(bool quiet, const gchar *db_file)
 
         ret = true;
 end:
-        update_end(u_handle, u_fname, ret);
-        cve_db_unlock();
-end_no_lock:
+        if (u_handle != -1)
+                update_end(u_handle, u_fname, ret);
+        if (db_locked)
+                cve_db_unlock();
         return ret;
+oom:
+        fputs("main(): Out of memory\n", stderr);
+        goto end;
 }
 
 /*