- We save our extended stat attributes using the name

  rsync.%stat now.  This keeps all our attriubutes in the
  rsync hierarchy, and the name should avoid a conflict with
  any namespace values that we might alias.
- If a Linux receiver is not running as root, it discards any
  non-user namespaces.  If it is running as fake-root, the non-
  user namespaces are stored in the rsync hierarchy.

diff --git a/fake-super.diff b/fake-super.diff
index 57fc95f..0766699 100644 (file)
--- a/fake-super.diff
+++ b/fake-super.diff
@@ -434,44 +434,98 @@ above:
  int preserve_perms = 0;
 --- old/xattr.c
 +++ new/xattr.c
-@@ -39,6 +39,12 @@ extern unsigned int file_struct_len;
- #define ROOT_PREFIX "root."
- #define RPRE_LEN (sizeof ROOT_PREFIX - 1)
+@@ -39,13 +39,23 @@ extern unsigned int file_struct_len;
+ #define SYSTEM_PREFIX "system."
+ #define SPRE_LEN ((int)sizeof SYSTEM_PREFIX - 1)
  
-+#ifdef HAVE_LINUX_XATTRS
-+#define FAKE_XATTR USER_PREFIX "rsync.%stat"
-+#else
-+#define FAKE_XATTR "rsync.%stat"
-+#endif
++#define RSYNC_PREFIX "rsync."
++#define XSTAT_SUFFIX "%stat"
++
+ #ifdef HAVE_LINUX_XATTRS
+ #define RPRE_LEN 0
++#define FAKE_PREFIX USER_PREFIX RSYNC_PREFIX
++#define FPRE_LEN ((int)sizeof FAKE_PREFIX - 1)
++#define XSTAT_ATTR USER_PREFIX RSYNC_PREFIX XSTAT_SUFFIX
+ #else
+-#define RSYNC_PREFIX "rsync."
+ #define RPRE_LEN ((int)sizeof RSYNC_PREFIX - 1)
++#define FPRE_LEN 0
++#define XSTAT_ATTR RSYNC_PREFIX XSTAT_SUFFIX
+ #endif
+ 
++#define XSTAT_LEN ((int)sizeof XSTAT_ATTR - 1)
++#define CENT_POS (UPRE_LEN + (int)sizeof RSYNC_PREFIX - 1)
 +
  typedef struct {
-       char *name;
-       char *datum;
-@@ -144,6 +150,10 @@ static int rsync_xal_get(const char *fna
+       char *datum, *name;
+       size_t datum_len, name_len;
+@@ -143,6 +153,10 @@ static int rsync_xal_get(const char *fna
                        continue;
  #endif
  
-+              if (am_root < 0 && len == sizeof FAKE_XATTR
-+               && name[11] == '%' && strcmp(name, FAKE_XATTR) == 0)
++              if (am_root < 0 && name_len == XSTAT_LEN
++               && name[CENT_POS] == '%' && strcmp(name, XSTAT_ATTR) == 0)
 +                      continue;
 +
+               datum_len = sys_lgetxattr(fname, name, NULL, 0);
+               if (datum_len < 0) {
+                       if (errno == ENOTSUP)
+@@ -173,6 +187,13 @@ static int rsync_xal_get(const char *fna
+                               return -1;
+                       }
+               }
++#ifdef HAVE_LINUX_XATTRS
++              if (am_root < 0 && name_len > FPRE_LEN
++               && strncmp(name, FAKE_PREFIX, FPRE_LEN) == 0) {
++                      name += FPRE_LEN;
++                      name_len -= FPRE_LEN;
++              }
++#endif
                rxas = EXPAND_ITEM_LIST(xalp, rsync_xa, RSYNC_XAL_INITIAL);
- 
-               datum_size = sys_lgetxattr(fname, name, NULL, 0);
-@@ -315,6 +325,12 @@ void receive_xattr(struct file_struct *f
-                               memmove(ptr, ptr + UPRE_LEN, rxa->name_len);
+               rxas->name = ptr + datum_len;
+               memcpy(rxas->name, name, name_len);
+@@ -293,20 +314,23 @@ void receive_xattr(struct file_struct *f
+                       rsync_xa *rxa;
+                       size_t name_len = read_int(f);
+                       size_t datum_len = read_int(f);
++                      size_t extra_len = am_root < 0 ? FPRE_LEN + RPRE_LEN : RPRE_LEN;
+                       if (name_len + datum_len < name_len)
+                               out_of_memory("receive_xattr"); /* overflow */
+-#ifndef HAVE_LINUX_XATTRS
+-                      if (name_len + datum_len + RPRE_LEN < RPRE_LEN)
++                      if (name_len + datum_len + extra_len < extra_len)
+                               out_of_memory("receive_xattr"); /* overflow */
+-#endif
+-                      ptr = new_array(char, name_len + datum_len + RPRE_LEN);
++                      ptr = new_array(char, name_len + datum_len + extra_len);
+                       if (!ptr)
+                               out_of_memory("receive_xattr");
+-                      name = ptr + datum_len + RPRE_LEN;
++                      name = ptr + datum_len + extra_len;
+                       read_buf(f, name, name_len);
+                       read_buf(f, ptr, datum_len);
+ #ifdef HAVE_LINUX_XATTRS
+                       /* Non-root can only save the user namespace. */
++                      if (am_root < 0 && strncmp(name, USER_PREFIX, UPRE_LEN) != 0) {
++                              name -= FPRE_LEN;
++                              memcpy(name, FAKE_PREFIX, FPRE_LEN);
++                      } else
+                       if (!am_root && strncmp(name, USER_PREFIX, UPRE_LEN) != 0) {
+                               free(ptr);
+                               continue;
+@@ -323,6 +347,11 @@ void receive_xattr(struct file_struct *f
+                               memcpy(name, RSYNC_PREFIX, RPRE_LEN);
                        }
  #endif
-+                      if (am_root < 0 && name_len == sizeof FAKE_XATTR
-+                       && ptr[11] == '%' && strcmp(ptr, FAKE_XATTR) == 0) {
++                      if (am_root < 0 && name_len == XSTAT_LEN
++                       && name[CENT_POS] == '%' && strcmp(name, XSTAT_ATTR) == 0) {
 +                              free(ptr);
-+                              temp_xattr.count--;
 +                              continue;
 +                      }
-               }
-               ndx = rsync_xal_l.count; /* pre-incremented count */
-               rsync_xal_store(&temp_xattr); /* adds item to rsync_xal_l */
-@@ -390,4 +406,146 @@ int set_xattr(const char *fname, const s
+                       rxa = EXPAND_ITEM_LIST(&temp_xattr, rsync_xa, count);
+                       rxa->name = name;
+                       rxa->name_len = name_len;
+@@ -403,4 +432,146 @@ int set_xattr(const char *fname, const s
        return rsync_xal_set(fname, lst + ndx); /* TODO:  This needs to return 1 if no xattrs changed! */
  }
  
@@ -489,10 +543,10 @@ above:
 +              xst = fst;
 +      if (fname) {
 +              fd = -1;
-+              len = sys_lgetxattr(fname, FAKE_XATTR, buf, sizeof buf - 1);
++              len = sys_lgetxattr(fname, XSTAT_ATTR, buf, sizeof buf - 1);
 +      } else {
 +              fname = "fd";
-+              len = sys_fgetxattr(fd, FAKE_XATTR, buf, sizeof buf - 1);
++              len = sys_fgetxattr(fd, XSTAT_ATTR, buf, sizeof buf - 1);
 +      }
 +      if (len >= (int)sizeof buf) {
 +              len = -1;
@@ -507,7 +561,7 @@ above:
 +                      return 0;
 +              }
 +              rsyserr(FERROR, errno, "failed to read xattr %s for %s",
-+                      FAKE_XATTR, full_fname(fname));
++                      XSTAT_ATTR, full_fname(fname));
 +              return -1;
 +      }
 +      buf[len] = '\0';
@@ -515,7 +569,7 @@ above:
 +      if (sscanf(buf, "%o %d,%d %d:%d",
 +                 &mode, &rdev_major, &rdev_minor, &uid, &gid) != 5) {
 +              rprintf(FERROR, "Corrupt %s xattr attached to %s: \"%s\"\n",
-+                      FAKE_XATTR, full_fname(fname), buf);
++                      XSTAT_ATTR, full_fname(fname), buf);
 +              exit_cleanup(RERR_FILEIO);
 +      }
 +
@@ -538,7 +592,7 @@ above:
 +
 +      if (read_only || list_only) {
 +              rsyserr(FERROR, EROFS, "failed to write xattr %s for %s",
-+                      FAKE_XATTR, full_fname(fname));
++                      XSTAT_ATTR, full_fname(fname));
 +              return -1;
 +      }
 +
@@ -564,7 +618,7 @@ above:
 +      if (mode == file->mode && fst.st_rdev == rdev
 +       && fst.st_uid == file->uid && fst.st_gid == file->gid) {
 +              /* xst.st_mode will be 0 if there's no current stat xattr */
-+              if (xst.st_mode && sys_lremovexattr(fname, FAKE_XATTR) < 0) {
++              if (xst.st_mode && sys_lremovexattr(fname, XSTAT_ATTR) < 0) {
 +                      rsyserr(FERROR, errno,
 +                              "delete of stat xattr failed for %s",
 +                              full_fname(fname));
@@ -580,12 +634,12 @@ above:
 +                      to_wire_mode(file->mode) & (_S_IFMT|CHMOD_BITS),
 +                      (int)major(rdev), (int)minor(rdev),
 +                      (int)file->uid, (int)file->gid);
-+              if (sys_lsetxattr(fname, FAKE_XATTR, buf, len) < 0) {
++              if (sys_lsetxattr(fname, XSTAT_ATTR, buf, len) < 0) {
 +                      if (errno == EPERM && S_ISLNK(fst.st_mode))
 +                              return 0;
 +                      rsyserr(FERROR, errno,
 +                              "failed to write xattr %s for %s",
-+                              FAKE_XATTR, full_fname(fname));
++                              XSTAT_ATTR, full_fname(fname));
 +                      return -1;
 +              }
 +      }