journal: automaticall reset location when the set of matches changes

[elogind.git] / src / util.c

diff --git a/src/util.c b/src/util.c
index 99737e4e63012ba66f33b8b86d679f0b2a39d129..e5b5e53f7e1c8a5c19cc1e75539b5c2cf96eab3d 100644 (file)
--- a/src/util.c
+++ b/src/util.c
@@ -2336,8 +2336,10 @@ int chvt(int vt) {
                         0
                 };
 
-                if (ioctl(fd, TIOCLINUX, tiocl) < 0)
-                        return -errno;
+                if (ioctl(fd, TIOCLINUX, tiocl) < 0) {
+                        r = -errno;
+                        goto fail;
+                }
 
                 vt = tiocl[0] <= 0 ? 1 : tiocl[0];
         }
@@ -2345,7 +2347,8 @@ int chvt(int vt) {
         if (ioctl(fd, VT_ACTIVATE, vt) < 0)
                 r = -errno;
 
-        close_nointr_nofail(r);
+fail:
+        close_nointr_nofail(fd);
         return r;
 }
 
@@ -3529,6 +3532,22 @@ int chmod_and_chown(const char *path, mode_t mode, uid_t uid, gid_t gid) {
         return 0;
 }
 
+int fchmod_and_fchown(int fd, mode_t mode, uid_t uid, gid_t gid) {
+        assert(fd >= 0);
+
+        /* Under the assumption that we are running privileged we
+         * first change the access mode and only then hand out
+         * ownership to avoid a window where access is too open. */
+
+        if (fchmod(fd, mode) < 0)
+                return -errno;
+
+        if (fchown(fd, uid, gid) < 0)
+                return -errno;
+
+        return 0;
+}
+
 cpu_set_t* cpu_set_malloc(unsigned *ncpus) {
         cpu_set_t *r;
         unsigned n = 1024;
@@ -5884,3 +5903,36 @@ int prot_from_flags(int flags) {
                 return -EINVAL;
         }
 }
+
+unsigned long cap_last_cap(void) {
+        static __thread unsigned long saved;
+        static __thread bool valid = false;
+        unsigned long p;
+
+        if (valid)
+                return saved;
+
+        p = (unsigned long) CAP_LAST_CAP;
+
+        if (prctl(PR_CAPBSET_READ, p) < 0) {
+
+                /* Hmm, look downwards, until we find one that
+                 * works */
+                for (p--; p > 0; p --)
+                        if (prctl(PR_CAPBSET_READ, p) >= 0)
+                                break;
+
+        } else {
+
+                /* Hmm, look upwards, until we find one that doesn't
+                 * work */
+                for (;; p++)
+                        if (prctl(PR_CAPBSET_READ, p+1) < 0)
+                                break;
+        }
+
+        saved = p;
+        valid = true;
+
+        return p;
+}