diff options
| -rw-r--r-- | libfstools/common.c | 46 |
1 files changed, 42 insertions, 4 deletions
diff --git a/libfstools/common.c b/libfstools/common.c index 55c1b87..e5b7bc3 100644 --- a/libfstools/common.c +++ b/libfstools/common.c @@ -63,9 +63,11 @@ int block_file_identify(FILE *f, uint64_t offset) return -1; n = fread(&magic, sizeof(magic), 1, f); - if (magic == cpu_to_le32(0x88b1f)) { + if (magic == cpu_to_le32(0x88b1f)) return FS_TARGZ; - } + + if (magic == cpu_to_be32(0xdeadc0de)) + return FS_DEADCODE; if (fseeko(f, offset + 0x400, SEEK_SET) < 0) return -1; @@ -113,17 +115,53 @@ int block_volume_format(struct volume *v, uint64_t offset, const char *bdev) { int ret = 0; char str[128]; + unsigned int skip_blocks = 0; + int fd; + __u32 deadc0de; + size_t sz; switch (volume_identify(v)) { + case FS_DEADCODE: + /* skip padding */ + fd = open(v->blk, O_RDONLY); + if (fd < 0) { + ret = EIO; + break; + } + do { + if (lseek(fd, (skip_blocks + 1) * 512, SEEK_SET) == (off_t) -1) { + ret = EIO; + break; + } + sz = read(fd, &deadc0de, sizeof(deadc0de)); + if (sz != sizeof(deadc0de)) { + ret = EIO; + break; + } + } while(++skip_blocks <= 512 && + (deadc0de == cpu_to_be32(0xdeadc0de) || deadc0de == 0xffffffff)); + + close(fd); + if (ret) + break; + + /* only try extracting in case gzip header is present */ + if (deadc0de != cpu_to_le32(0x88b1f)) + goto do_format; + + /* fall-through */ case FS_TARGZ: - snprintf(str, sizeof(str), "gzip -cd %s > /tmp/sysupgrade.tar", v->blk); + snprintf(str, sizeof(str), + "dd if=%s bs=512 skip=%u 2>/dev/null | gzip -cd > /tmp/sysupgrade.tar 2>/dev/null", + v->blk, skip_blocks); ret = system(str); if (ret < 0) { - ULOG_ERR("failed extracting %s\n", v->blk); + ULOG_ERR("failed extracting config backup from %s\n", v->blk); break; } /* fall-through */ case FS_NONE: +do_format: ULOG_INFO("overlay filesystem in %s has not been formatted yet\n", v->blk); if (use_f2fs(v, offset, bdev)) snprintf(str, sizeof(str), "mkfs.f2fs -q -l rootfs_data %s", v->blk); |