Add become_root() capability to nfsv4_chmod()

[netatalk.git] / libatalk / util / unix.c

diff --git a/libatalk/util/unix.c b/libatalk/util/unix.c
index 9e71fcb4b71a3b7fd53479c4cebc2cef7cb3bb30..e4cb21e8c12e95e828afb608430a73c8c034ebf8 100644 (file)
--- a/libatalk/util/unix.c
+++ b/libatalk/util/unix.c
@@ -41,6 +41,75 @@
 #include <atalk/util.h>
 #include <atalk/unix.h>
 
+/* close all FDs >= a specified value */
+static void closeall(int fd)
+{
+    int fdlimit = sysconf(_SC_OPEN_MAX);
+
+    while (fd < fdlimit)
+        close(fd++);
+}
+
+/*!
+ * Daemonize
+ *
+ * Fork, exit parent, setsid(), optionally chdir("/"), optionally close all fds
+ *
+ * returns -1 on failure, but you can't do much except exit in that case
+ * since we may already have forked
+ */
+int daemonize(int nochdir, int noclose)
+{
+    switch (fork()) {
+    case 0:
+        break;
+    case -1:
+        return -1;
+    default:
+        _exit(0);
+    }
+
+    if (setsid() < 0)
+        return -1;
+
+    switch (fork()) {
+    case 0: 
+        break;
+    case -1:
+        return -1;
+    default:
+        _exit(0);
+    }
+
+    if (!nochdir)
+        chdir("/");
+
+    if (!noclose) {
+        closeall(0);
+        open("/dev/null",O_RDWR);
+        dup(0);
+        dup(0);
+    }
+
+    return 0;
+}
+
+static uid_t saved_uid = -1;
+
+void become_root(void)
+{
+    saved_uid = geteuid();
+    if (seteuid(0) != 0)
+        AFP_PANIC("Can't seteuid(0)");
+}
+
+void unbecome_root(void)
+{
+    if (saved_uid == -1 || seteuid(saved_uid) < 0)
+        AFP_PANIC("Can't seteuid back");
+    saved_uid = -1;
+}
+
 /*!
  * @brief get cwd in static buffer
  *
@@ -57,6 +126,28 @@ const char *getcwdpath(void)
         return strerror(errno);
 }
 
+/*!
+ * @brief Request absolute path
+ *
+ * @returns Absolute filesystem path to object
+ */
+const char *fullpathname(const char *name)
+{
+    static char wd[MAXPATHLEN + 1];
+
+    if (name[0] == '/')
+        return name;
+
+    if (getcwd(wd , MAXPATHLEN)) {
+        strlcat(wd, "/", MAXPATHLEN);
+        strlcat(wd, name, MAXPATHLEN);
+    } else {
+        strlcpy(wd, name, MAXPATHLEN);
+    }
+
+    return wd;
+}
+
 /*!
  * Takes a buffer with a path, strips slashs, returns basename
  *