| Message ID | 20220215124042.186506-4-roberto.sassu@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | bpf-lsm: Extend interoperability with IMA | expand |
On 2/15/22 4:40 AM, Roberto Sassu wrote: > ima_file_hash() has been modified to calculate the measurement of a file on > demand, if it has not been already performed by IMA. For compatibility > reasons, ima_inode_hash() remains unchanged. > > Keep the same approach in eBPF and introduce the new helper > bpf_ima_file_hash() to take advantage of the modified behavior of > ima_file_hash(). > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > --- > include/uapi/linux/bpf.h | 11 +++++++++++ > kernel/bpf/bpf_lsm.c | 20 ++++++++++++++++++++ > tools/include/uapi/linux/bpf.h | 11 +++++++++++ > 3 files changed, 42 insertions(+) > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index b0383d371b9a..ba33d5718d6b 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -4648,6 +4648,16 @@ union bpf_attr { > * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if > * invalid arguments are passed. > * > + * long bpf_ima_file_hash(struct file *file, void *dst, u32 size) > + * Description > + * Returns a calculated IMA hash of the *file*. > + * If the hash is larger than *size*, then only *size* > + * bytes will be copied to *dst* > + * Return > + * The **hash_algo** is returned on success, > + * **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if > + * invalid arguments are passed. > + * > * struct socket *bpf_sock_from_file(struct file *file) > * Description > * If the given file represents a socket, returns the associated > @@ -5182,6 +5192,7 @@ union bpf_attr { > FN(bprm_opts_set), \ > FN(ktime_get_coarse_ns), \ > FN(ima_inode_hash), \ > + FN(ima_file_hash), \ Please put the above FN(ima_file_hash) to the end of the list. Otherwise, we have a backward compatability issue. > FN(sock_from_file), \ > FN(check_mtu), \ > FN(for_each_map_elem), \ > diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c > index 9e4ecc990647..e8d27af5bbcc 100644 > --- a/kernel/bpf/bpf_lsm.c > +++ b/kernel/bpf/bpf_lsm.c [...]
> From: Yonghong Song [mailto:yhs@fb.com] > Sent: Tuesday, February 15, 2022 6:03 PM > On 2/15/22 4:40 AM, Roberto Sassu wrote: > > ima_file_hash() has been modified to calculate the measurement of a file on > > demand, if it has not been already performed by IMA. For compatibility > > reasons, ima_inode_hash() remains unchanged. > > > > Keep the same approach in eBPF and introduce the new helper > > bpf_ima_file_hash() to take advantage of the modified behavior of > > ima_file_hash(). > > > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > > --- > > include/uapi/linux/bpf.h | 11 +++++++++++ > > kernel/bpf/bpf_lsm.c | 20 ++++++++++++++++++++ > > tools/include/uapi/linux/bpf.h | 11 +++++++++++ > > 3 files changed, 42 insertions(+) > > > > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > > index b0383d371b9a..ba33d5718d6b 100644 > > --- a/include/uapi/linux/bpf.h > > +++ b/include/uapi/linux/bpf.h > > @@ -4648,6 +4648,16 @@ union bpf_attr { > > * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if > > * invalid arguments are passed. > > * > > + * long bpf_ima_file_hash(struct file *file, void *dst, u32 size) > > + * Description > > + * Returns a calculated IMA hash of the *file*. > > + * If the hash is larger than *size*, then only *size* > > + * bytes will be copied to *dst* > > + * Return > > + * The **hash_algo** is returned on success, > > + * **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** > if > > + * invalid arguments are passed. > > + * > > * struct socket *bpf_sock_from_file(struct file *file) > > * Description > > * If the given file represents a socket, returns the associated > > @@ -5182,6 +5192,7 @@ union bpf_attr { > > FN(bprm_opts_set), \ > > FN(ktime_get_coarse_ns), \ > > FN(ima_inode_hash), \ > > + FN(ima_file_hash), \ > > Please put the above FN(ima_file_hash) to the end of the list. > Otherwise, we have a backward compatability issue. Hi Yonghong sure, will do. Thanks Roberto HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Li Peng, Zhong Ronghua > > FN(sock_from_file), \ > > FN(check_mtu), \ > > FN(for_each_map_elem), \ > > diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c > > index 9e4ecc990647..e8d27af5bbcc 100644 > > --- a/kernel/bpf/bpf_lsm.c > > +++ b/kernel/bpf/bpf_lsm.c > [...]
diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index b0383d371b9a..ba33d5718d6b 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4648,6 +4648,16 @@ union bpf_attr { * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if * invalid arguments are passed. * + * long bpf_ima_file_hash(struct file *file, void *dst, u32 size) + * Description + * Returns a calculated IMA hash of the *file*. + * If the hash is larger than *size*, then only *size* + * bytes will be copied to *dst* + * Return + * The **hash_algo** is returned on success, + * **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if + * invalid arguments are passed. + * * struct socket *bpf_sock_from_file(struct file *file) * Description * If the given file represents a socket, returns the associated @@ -5182,6 +5192,7 @@ union bpf_attr { FN(bprm_opts_set), \ FN(ktime_get_coarse_ns), \ FN(ima_inode_hash), \ + FN(ima_file_hash), \ FN(sock_from_file), \ FN(check_mtu), \ FN(for_each_map_elem), \ diff --git a/kernel/bpf/bpf_lsm.c b/kernel/bpf/bpf_lsm.c index 9e4ecc990647..e8d27af5bbcc 100644 --- a/kernel/bpf/bpf_lsm.c +++ b/kernel/bpf/bpf_lsm.c @@ -99,6 +99,24 @@ static const struct bpf_func_proto bpf_ima_inode_hash_proto = { .allowed = bpf_ima_inode_hash_allowed, }; +BPF_CALL_3(bpf_ima_file_hash, struct file *, file, void *, dst, u32, size) +{ + return ima_file_hash(file, dst, size); +} + +BTF_ID_LIST_SINGLE(bpf_ima_file_hash_btf_ids, struct, file) + +static const struct bpf_func_proto bpf_ima_file_hash_proto = { + .func = bpf_ima_file_hash, + .gpl_only = false, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_BTF_ID, + .arg1_btf_id = &bpf_ima_file_hash_btf_ids[0], + .arg2_type = ARG_PTR_TO_UNINIT_MEM, + .arg3_type = ARG_CONST_SIZE, + .allowed = bpf_ima_inode_hash_allowed, +}; + static const struct bpf_func_proto * bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -121,6 +139,8 @@ bpf_lsm_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_bprm_opts_set_proto; case BPF_FUNC_ima_inode_hash: return prog->aux->sleepable ? &bpf_ima_inode_hash_proto : NULL; + case BPF_FUNC_ima_file_hash: + return prog->aux->sleepable ? &bpf_ima_file_hash_proto : NULL; default: return tracing_prog_func_proto(func_id, prog); } diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index b0383d371b9a..ba33d5718d6b 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4648,6 +4648,16 @@ union bpf_attr { * **-EOPNOTSUP** if IMA is disabled or **-EINVAL** if * invalid arguments are passed. * + * long bpf_ima_file_hash(struct file *file, void *dst, u32 size) + * Description + * Returns a calculated IMA hash of the *file*. + * If the hash is larger than *size*, then only *size* + * bytes will be copied to *dst* + * Return + * The **hash_algo** is returned on success, + * **-EOPNOTSUP** if the hash calculation failed or **-EINVAL** if + * invalid arguments are passed. + * * struct socket *bpf_sock_from_file(struct file *file) * Description * If the given file represents a socket, returns the associated @@ -5182,6 +5192,7 @@ union bpf_attr { FN(bprm_opts_set), \ FN(ktime_get_coarse_ns), \ FN(ima_inode_hash), \ + FN(ima_file_hash), \ FN(sock_from_file), \ FN(check_mtu), \ FN(for_each_map_elem), \
ima_file_hash() has been modified to calculate the measurement of a file on demand, if it has not been already performed by IMA. For compatibility reasons, ima_inode_hash() remains unchanged. Keep the same approach in eBPF and introduce the new helper bpf_ima_file_hash() to take advantage of the modified behavior of ima_file_hash(). Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> --- include/uapi/linux/bpf.h | 11 +++++++++++ kernel/bpf/bpf_lsm.c | 20 ++++++++++++++++++++ tools/include/uapi/linux/bpf.h | 11 +++++++++++ 3 files changed, 42 insertions(+)