This patch specifically implements the function of calculating image checksum and provides interface function that enables fsck to call to complete the calculation of image checksum.
Signed-off-by: Jiawei Wang <[email protected]> --- fsck/fssum.c | 244 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 244 insertions(+) diff --git a/fsck/fssum.c b/fsck/fssum.c index b650641..9bcea1f 100644 --- a/fsck/fssum.c +++ b/fsck/fssum.c @@ -267,3 +267,247 @@ char* erofs_fssum_sum2string(struct erofs_sum_t *dst) return s; } + +int erofs_fssum_traverse_dirents(struct erofs_dir_context *ctx, + void *dentry_blk, unsigned int lblk, + unsigned int next_nameoff, unsigned int maxsize, + struct erofs_sum_t *dircs, int level) +{ + struct erofs_sb_info *sbi = ctx->dir->sbi; + struct erofs_dirent *de = dentry_blk; + const struct erofs_dirent *end = dentry_blk + next_nameoff; + const char *prev_name = NULL; + const char *errmsg; + unsigned int prev_namelen = 0; + int ret = 0; + bool silent = false; + + while (de < end) { + const char *de_name; + unsigned int de_namelen; + unsigned int nameoff; + + nameoff = le16_to_cpu(de->nameoff); + de_name = (char *)dentry_blk + nameoff; + + /* the last dirent check */ + if (de + 1 >= end) + de_namelen = strnlen(de_name, maxsize - nameoff); + else + de_namelen = le16_to_cpu(de[1].nameoff) - nameoff; + + ctx->de_nid = le64_to_cpu(de->nid); + erofs_dbg("traversed nid (%llu)", ctx->de_nid | 0ULL); + + ret = -EFSCORRUPTED; + /* corrupted entry check */ + if (nameoff != next_nameoff) { + errmsg = "bogus dirent nameoff"; + break; + } + + if (nameoff + de_namelen > maxsize || !de_namelen || + de_namelen > EROFS_NAME_LEN) { + errmsg = "bogus dirent namelen"; + break; + } + + ctx->dname = de_name; + ctx->de_namelen = de_namelen; + ctx->de_ftype = de->file_type; + ctx->dot_dotdot = is_dot_dotdot_len(de_name, de_namelen); + ret = erofs_fssum_sum(ctx, dircs, level); + if (ret) { + silent = true; + break; + } + prev_name = de_name; + prev_namelen = de_namelen; + next_nameoff += de_namelen; + ++de; + } +out: + if (ret && !silent) + erofs_err("%s @ nid %llu, lblk %u, index %lu", + errmsg, ctx->dir->nid | 0ULL, lblk, + (de - (struct erofs_dirent *)dentry_blk) | 0UL); + return ret; +} + +int erofs_fssum_iterate_dir(struct erofs_dir_context *ctx, struct erofs_sum_t *dircs, int level) +{ + struct erofs_inode *dir = ctx->dir; + struct erofs_sb_info *sbi = dir->sbi; + int err = 0; + erofs_off_t pos; + char buf[EROFS_MAX_BLOCK_SIZE]; + + if (!S_ISDIR(dir->i_mode)) + return -ENOTDIR; + + ctx->flags &= ~EROFS_READDIR_ALL_SPECIAL_FOUND; + pos = 0; + while (pos < dir->i_size) { + erofs_blk_t lblk = erofs_blknr(sbi, pos); + erofs_off_t maxsize = min_t(erofs_off_t, + dir->i_size - pos, erofs_blksiz(sbi)); + const struct erofs_dirent *de = (const void *)buf; + unsigned int nameoff; + + err = erofs_pread(dir, buf, maxsize, pos); + if (err) { + erofs_err("I/O error occurred when reading dirents @ nid %llu, lblk %u: %d", + dir->nid | 0ULL, lblk, err); + return err; + } + + nameoff = le16_to_cpu(de->nameoff); + if (nameoff < sizeof(struct erofs_dirent) || + nameoff >= erofs_blksiz(sbi)) { + erofs_err("invalid de[0].nameoff %u @ nid %llu, lblk %u", + nameoff, dir->nid | 0ULL, lblk); + return -EFSCORRUPTED; + } + err = erofs_fssum_traverse_dirents(ctx, buf, lblk, nameoff, maxsize, dircs, level); + if (err) + break; + pos += maxsize; + } + + return err; +} + +int erofs_fssum_sum(struct erofs_dir_context *ctx, struct erofs_sum_t *dircs, int level) +{ + int err; + struct erofs_sum_t meta; + struct erofs_sum_t cs; + struct erofs_inode vi = { .sbi = &g_sbi, .nid = ctx->de_nid }; + + + if (ctx->dot_dotdot) + return 0; + + err = erofs_read_inode_from_disk(&vi); + if (err) { + erofs_err("failed to read file inode from disk"); + return err; + } + + erofs_fssum_init(&meta); + erofs_fssum_init(&cs); + + erofs_fssum_addu64(&meta, level); + erofs_fssum_add(&meta, ctx->dname, ctx->de_namelen); + if (!S_ISDIR(vi.i_mode)) + erofs_fssum_addu64(&meta, vi.i_nlink); + erofs_fssum_addu64(&meta, vi.i_uid); + erofs_fssum_addu64(&meta, vi.i_gid); + erofs_fssum_addu64(&meta, vi.i_mode); + erofs_fssum_addtime(&meta, vi.i_mtime); + + if (S_ISDIR(vi.i_mode) || S_ISREG(vi.i_mode)) { + ssize_t kllen; + ssize_t ret; + char *keylst, *key; + + kllen = erofs_listxattr(&vi, NULL, 0); + if (kllen < 0) + return kllen; + + keylst = malloc(kllen); + if(!keylst) + return -ENOMEM; + + ret = erofs_listxattr(&vi, keylst, kllen); + if (ret < 0) { + free(keylst); + return err; + } + + for (key = keylst; key < keylst + kllen; key += strlen(key) + 1) { + char *value; + ssize_t size; + + ret = erofs_getxattr(&vi, key, NULL, 0); + if (ret < 0) + return ret; + + erofs_fssum_add(&meta, key, strlen(key)); + if (ret == 0) + continue; + if (ret) { + size = ret; + value = malloc(size); + if (!value) + return -ENOMEM; + ret = erofs_getxattr(&vi, key, value, size); + if (ret < 0){ + free(value); + free(keylst); + return ret; + } + erofs_fssum_add(&meta, value, size); + printf("key:%s val:%s\n", key, value); + } + } + free(keylst); + } + + if (S_ISDIR(vi.i_mode)) { + struct erofs_dir_context nctx = { + .flags = ctx->dir ? EROFS_READDIR_VALID_PNID : 0, + .pnid = ctx->dir ? ctx->dir->nid : 0, + .dir = &vi, + }; + + err = erofs_fssum_iterate_dir(&nctx, &cs, level + 1); + if (err) + return err; + } else { + if (S_ISREG(vi.i_mode)) { + erofs_fssum_addu64(&meta, vi.i_size); + err = erofs_fssum_addinode(&cs, vi); + if (err) + return err; + } else if (S_ISLNK(vi.i_mode)) { + err = erofs_fssum_addinode(&cs, vi); + if (err) + return err; + } else if (S_ISCHR(vi.i_mode) || S_ISBLK(vi.i_mode)) { + erofs_fssum_addu64(&cs, major(vi.u.i_rdev)); + erofs_fssum_addu64(&cs, minor(vi.u.i_rdev)); + } + } + + erofs_fssum_fini(&cs); + erofs_fssum_fini(&meta); + erofs_fssum_addsum(dircs, &cs); + erofs_fssum_addsum(dircs, &meta); + + return 0; +} + +int erofs_fssum_calculate(struct erofs_dir_context *ctx) +{ + struct erofs_sum_t ans_cs; + struct erofs_inode vi = { .sbi = &g_sbi, .nid = ctx->de_nid }; + struct erofs_dir_context nctx = { + .flags = ctx->dir ? EROFS_READDIR_VALID_PNID : 0, + .pnid = ctx->dir ? ctx->dir->nid : 0, + .dir = &vi, + }; + int ret = 0; + + ret = erofs_read_inode_from_disk(&vi); + if (ret) { + erofs_err("failed to read file inode from disk"); + return ret; + } + erofs_fssum_init(&ans_cs); + ret = erofs_fssum_iterate_dir(&nctx, &ans_cs, 1); + erofs_fssum_fini(&ans_cs); + fprintf(stdout, "%s\n", erofs_fssum_sum2string(&ans_cs)); + + return ret; +} -- 2.34.1
