[PATCH 1/3] erofs-utils: lib: tar: ignore useless fields of PAX extended headers

[Gao Xiang]

Since some unknown writer just leaves zero-filled mtime, e.g.
registry.k8s.io/pause:3.6  --platform windows

Layer sha256: bc8517709e9cfff223cb034ff5be8fcbfa5409de286cdac9ae1b8878ebea6b84

Fixes: 95d315fd7958 ("erofs-utils: introduce tarerofs")
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
 lib/tar.c | 78 ++++++++++++++++++++++++++++++-------------------------
 1 file changed, 42 insertions(+), 36 deletions(-)

diff --git a/lib/tar.c b/lib/tar.c
index 0dd990e..12bf595 100644
--- a/lib/tar.c
+++ b/lib/tar.c
@@ -659,6 +659,7 @@ int tarerofs_parse_tar(struct erofs_inode *root, struct 
erofs_tarfile *tar)
        struct erofs_sb_info *sbi = root->sbi;
        bool whout, opq, e = false;
        struct stat st;
+       mode_t mode;
        erofs_off_t tar_offset, dataoff;
 
        struct tar_header *th;
@@ -751,26 +752,6 @@ out_eot:
                goto out;
        }
 
-       st.st_mode = tarerofs_otoi(th->mode, sizeof(th->mode));
-       if (errno)
-               goto invalid_tar;
-
-       if (eh.use_uid) {
-               st.st_uid = eh.st.st_uid;
-       } else {
-               st.st_uid = tarerofs_parsenum(th->uid, sizeof(th->uid));
-               if (errno)
-                       goto invalid_tar;
-       }
-
-       if (eh.use_gid) {
-               st.st_gid = eh.st.st_gid;
-       } else {
-               st.st_gid = tarerofs_parsenum(th->gid, sizeof(th->gid));
-               if (errno)
-                       goto invalid_tar;
-       }
-
        if (eh.use_size) {
                st.st_size = eh.st.st_size;
        } else {
@@ -779,16 +760,6 @@ out_eot:
                        goto invalid_tar;
        }
 
-       if (eh.use_mtime) {
-               st.st_mtime = eh.st.st_mtime;
-               ST_MTIM_NSEC_SET(&st, ST_MTIM_NSEC(&eh.st));
-       } else {
-               st.st_mtime = tarerofs_parsenum(th->mtime, sizeof(th->mtime));
-               if (errno)
-                       goto invalid_tar;
-               ST_MTIM_NSEC_SET(&st, 0);
-       }
-
        if (th->typeflag <= '7' && !eh.path) {
                eh.path = path;
                j = 0;
@@ -810,28 +781,29 @@ out_eot:
 
        dataoff = tar->offset;
        tar->offset += st.st_size;
+       st.st_mode = 0;
        switch(th->typeflag) {
        case '0':
        case '7':
        case '1':
-               st.st_mode |= S_IFREG;
+               st.st_mode = S_IFREG;
                if (tar->headeronly_mode || tar->ddtaridx_mode)
                        tar->offset -= st.st_size;
                break;
        case '2':
-               st.st_mode |= S_IFLNK;
+               st.st_mode = S_IFLNK;
                break;
        case '3':
-               st.st_mode |= S_IFCHR;
+               st.st_mode = S_IFCHR;
                break;
        case '4':
-               st.st_mode |= S_IFBLK;
+               st.st_mode = S_IFBLK;
                break;
        case '5':
-               st.st_mode |= S_IFDIR;
+               st.st_mode = S_IFDIR;
                break;
        case '6':
-               st.st_mode |= S_IFIFO;
+               st.st_mode = S_IFIFO;
                break;
        case 'g':
                ret = tarerofs_parse_pax_header(&tar->ios, &tar->global,
@@ -876,6 +848,40 @@ out_eot:
                goto out;
        }
 
+       mode = tarerofs_otoi(th->mode, sizeof(th->mode));
+       if (errno)
+               goto invalid_tar;
+       if (__erofs_unlikely(mode & S_IFMT) &&
+           (mode & S_IFMT) != (st.st_mode & S_IFMT))
+               erofs_warn("invalid ustar mode %05o @ %llu", mode, tar_offset);
+       st.st_mode |= mode & ~S_IFMT;
+
+       if (eh.use_uid) {
+               st.st_uid = eh.st.st_uid;
+       } else {
+               st.st_uid = tarerofs_parsenum(th->uid, sizeof(th->uid));
+               if (errno)
+                       goto invalid_tar;
+       }
+
+       if (eh.use_gid) {
+               st.st_gid = eh.st.st_gid;
+       } else {
+               st.st_gid = tarerofs_parsenum(th->gid, sizeof(th->gid));
+               if (errno)
+                       goto invalid_tar;
+       }
+
+       if (eh.use_mtime) {
+               st.st_mtime = eh.st.st_mtime;
+               ST_MTIM_NSEC_SET(&st, ST_MTIM_NSEC(&eh.st));
+       } else {
+               st.st_mtime = tarerofs_parsenum(th->mtime, sizeof(th->mtime));
+               if (errno)
+                       goto invalid_tar;
+               ST_MTIM_NSEC_SET(&st, 0);
+       }
+
        st.st_rdev = 0;
        if (S_ISBLK(st.st_mode) || S_ISCHR(st.st_mode)) {
                int major, minor;
-- 
2.39.3 (Apple Git-146)