On 4/27/2011 5:34 AM, Roberto Sassu wrote: > The new LSM hook security_file_getsecid() and its implementation in the > capability module, SELinux and SMACK allows to obtain the security > identifier associated to a file descriptor. Why do you want a secid? You have the security information from the file structure readily available. What use to you intend to put this to? > Signed-off-by: Roberto Sassu <roberto.sassu@xxxxxxxxx> > --- > include/linux/security.h | 12 ++++++++++++ > security/capability.c | 6 ++++++ > security/security.c | 6 ++++++ > security/selinux/hooks.c | 7 +++++++ > security/smack/smack_lsm.c | 11 +++++++++++ > 5 files changed, 42 insertions(+), 0 deletions(-) > > diff --git a/include/linux/security.h b/include/linux/security.h > index ca02f17..6e73a1a 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -630,6 +630,11 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) > * to receive an open file descriptor via socket IPC. > * @file contains the file structure being received. > * Return 0 if permission is granted. > + * @file_getsecid: > + * Get the secid associated with the file descriptor. > + * @file contains a pointer to the file descriptor. > + * @secid contains a pointer to the location where result will be saved. > + * In case of failure, @secid will be set to zero. > * > * Security hook for dentry > * > @@ -1492,6 +1497,7 @@ struct security_operations { > int (*file_send_sigiotask) (struct task_struct *tsk, > struct fown_struct *fown, int sig); > int (*file_receive) (struct file *file); > + void (*file_getsecid)(const struct file *file, u32 *secid); > int (*dentry_open) (struct file *file, const struct cred *cred); > > int (*task_create) (unsigned long clone_flags); > @@ -1751,6 +1757,7 @@ int security_file_set_fowner(struct file *file); > int security_file_send_sigiotask(struct task_struct *tsk, > struct fown_struct *fown, int sig); > int security_file_receive(struct file *file); > +void security_file_getsecid(const struct file *file, u32 *secid); > int security_dentry_open(struct file *file, const struct cred *cred); > int security_task_create(unsigned long clone_flags); > int security_cred_alloc_blank(struct cred *cred, gfp_t gfp); > @@ -2251,6 +2258,11 @@ static inline int security_file_receive(struct file *file) > return 0; > } > > +static inline void security_file_getsecid(const struct file *file, u32 *secid) > +{ > + *secid = 0; > +} > + > static inline int security_dentry_open(struct file *file, > const struct cred *cred) > { > diff --git a/security/capability.c b/security/capability.c > index 2984ea4..fcb569d 100644 > --- a/security/capability.c > +++ b/security/capability.c > @@ -349,6 +349,11 @@ static int cap_file_receive(struct file *file) > return 0; > } > > +static void cap_file_getsecid(const struct file *file, u32 *secid) > +{ > + *secid = 0; > +} > + > static int cap_dentry_open(struct file *file, const struct cred *cred) > { > return 0; > @@ -953,6 +958,7 @@ void __init security_fixup_ops(struct security_operations *ops) > set_to_cap_if_null(ops, file_set_fowner); > set_to_cap_if_null(ops, file_send_sigiotask); > set_to_cap_if_null(ops, file_receive); > + set_to_cap_if_null(ops, file_getsecid); > set_to_cap_if_null(ops, dentry_open); > set_to_cap_if_null(ops, task_create); > set_to_cap_if_null(ops, cred_alloc_blank); > diff --git a/security/security.c b/security/security.c > index 1011423..9973dab 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -688,6 +688,12 @@ int security_file_receive(struct file *file) > return security_ops->file_receive(file); > } > > +void security_file_getsecid(const struct file *file, u32 *secid) > +{ > + security_ops->file_getsecid(file, secid); > +} > +EXPORT_SYMBOL(security_file_getsecid); > + > int security_dentry_open(struct file *file, const struct cred *cred) > { > int ret; > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 6772687..e1e787c 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -3179,6 +3179,12 @@ static int selinux_file_receive(struct file *file) > return file_has_perm(cred, file, file_to_av(file)); > } > > +static void selinux_file_getsecid(const struct file *file, u32 *secid) > +{ > + struct file_security_struct *fsec = file->f_security; > + *secid = fsec->sid; > +} > + > static int selinux_dentry_open(struct file *file, const struct cred *cred) > { > struct file_security_struct *fsec; > @@ -5498,6 +5504,7 @@ static struct security_operations selinux_ops = { > .file_set_fowner = selinux_file_set_fowner, > .file_send_sigiotask = selinux_file_send_sigiotask, > .file_receive = selinux_file_receive, > + .file_getsecid = selinux_file_getsecid, > > .dentry_open = selinux_dentry_open, > > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index 6612ba1..a583736 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -1304,6 +1304,16 @@ static int smack_file_receive(struct file *file) > return smk_curacc(file->f_security, may, &ad); > } > > +/** > + * smack_file_getsecid - Extract file descriptor's security id > + * @file: file descriptor to extract the info from > + * @secid: where result will be saved > + */ > +static void smack_file_getsecid(const struct file *file, u32 *secid) > +{ > + *secid = smack_to_secid(file->f_security); > +} > + > /* > * Task hooks > */ > @@ -3434,6 +3444,7 @@ struct security_operations smack_ops = { > .file_set_fowner = smack_file_set_fowner, > .file_send_sigiotask = smack_file_send_sigiotask, > .file_receive = smack_file_receive, > + .file_getsecid = smack_file_getsecid, > > .cred_alloc_blank = smack_cred_alloc_blank, > .cred_free = smack_cred_free, -- This message was distributed to subscribers of the selinux mailing list. 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