[libvirt] [PATCH v6 2/5] util: Create virFileAccessibleAs function
This function checks if a given path is accessible under
given uid and gid.
---
src/util/util.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
src/util/util.h | 3 ++
2 files changed, 75 insertions(+), 0 deletions(-)
diff --git a/src/util/util.c b/src/util/util.c
index af27344..f21e929 100644
--- a/src/util/util.c
+++ b/src/util/util.c
@@ -671,6 +671,66 @@ virFileIsExecutable(const char *file)
}
#ifndef WIN32
+/* Check that a file is accessible under certain
+ * user & gid.
+ * @mode can be F_OK, or a bitwise combination of R_OK, W_OK, and X_OK.
+ * see 'man access' for more details.
+ * Returns 0 on success, -1 on fail with errno set.
+ */
+int
+virFileAccessibleAs(const char *path, int mode,
+ uid_t uid, gid_t gid)
+{
+ pid_t pid = 0;
+ int status, ret = 0;
+ int forkRet = 0;
+
+ if (uid == getuid() &&
+ gid == getgid())
+ return access(path, mode);
+
+ forkRet = virFork(&pid);
+
+ if (pid < 0) {
+ return -1;
+ }
+
+ if (pid) { /* parent */
+ if (virPidWait(pid, &status) < 0) {
+ /* virPidWait() already
+ * reported error */
+ return -1;
+ }
+
+ return -(status & 0xFF);
+ }
+
+ /* child.
+ * Return positive value here. Parent
+ * will change it to negative one. */
+
+ if (forkRet < 0) {
+ ret = 1;
+ goto childerror;
+ }
+
+ if (virSetUIDGID(uid, gid) < 0) {
+ ret = 1;
+ goto childerror;
+ }
+
+ if (access(path, mode) < 0)
+ ret = 1;
+
+childerror:
+ if ((ret & 0xFF) != ret) {
+ VIR_WARN("unable to pass desired return value %d", ret);
+ ret = 0xFF;
+ }
+
+ _exit(ret);
+}
+
/* return -errno on failure, or 0 on success */
static int
virFileOpenAsNoFork(const char *path, int openflags, mode_t mode,
@@ -993,6 +1053,18 @@ childerror:
#else /* WIN32 */
+int
+virFileAccessibleAs(const char *path,
+ int mode,
+ uid_t uid ATTRIBUTE_UNUSED,
+ git_t gid ATTRIBUTE_UNUSED)
+{
+
+ VIR_WARN("Ignoring uid/gid due to WIN32");
+
+ return access(path, mode);
+}
+
/* return -errno on failure, or 0 on success */
int virFileOpenAs(const char *path ATTRIBUTE_UNUSED,
int openflags ATTRIBUTE_UNUSED,
diff --git a/src/util/util.h b/src/util/util.h
index c55e852..e869f1b 100644
--- a/src/util/util.h
+++ b/src/util/util.h
@@ -93,6 +93,9 @@ enum {
VIR_FILE_OPEN_AS_UID = (1 << 0),
VIR_FILE_OPEN_FORCE_PERMS = (1 << 1),
};
+int virFileAccessibleAs(const char *path, int mode,
+ uid_t uid, gid_t gid)
+ ATTRIBUTE_NONNULL(1) ATTRIBUTE_RETURN_CHECK;
int virFileOpenAs(const char *path, int openflags, mode_t mode,
uid_t uid, gid_t gid,
unsigned int flags)
--
1.7.3.4