This patch against 2.5.69 implements a process attribute API for
security modules via a set of nodes in a /proc/pid/attr directory.
Credit for the idea of implementing this API via /proc/pid/attr nodes
goes to Al Viro. Jan Harkes provided a nice cleanup of the
implementation to reduce the code bloat. Al, if you approve of this
change, please acknowledge. If not, please advise as to what must
change. Thanks.
fs/proc/base.c | 187 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/security.h | 23 +++++
security/dummy.c | 12 +++
3 files changed, 222 insertions(+)
Index: linux-2.5/fs/proc/base.c
diff -u linux-2.5/fs/proc/base.c:1.1.1.3 linux-2.5/fs/proc/base.c:1.8
--- linux-2.5/fs/proc/base.c:1.1.1.3 Mon Apr 21 10:15:46 2003
+++ linux-2.5/fs/proc/base.c Wed Apr 30 14:26:51 2003
@@ -58,6 +58,11 @@
PROC_PID_MAPS,
PROC_PID_MOUNTS,
PROC_PID_WCHAN,
+ PROC_PID_ATTR,
+ PROC_PID_ATTR_CURRENT,
+ PROC_PID_ATTR_PREV,
+ PROC_PID_ATTR_EXEC,
+ PROC_PID_ATTR_FSCREATE,
PROC_PID_FD_DIR = 0x8000, /* 0x8000-0xffff */
};
@@ -82,11 +87,19 @@
E(PROC_PID_ROOT, "root", S_IFLNK|S_IRWXUGO),
E(PROC_PID_EXE, "exe", S_IFLNK|S_IRWXUGO),
E(PROC_PID_MOUNTS, "mounts", S_IFREG|S_IRUGO),
+ E(PROC_PID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO),
#ifdef CONFIG_KALLSYMS
E(PROC_PID_WCHAN, "wchan", S_IFREG|S_IRUGO),
#endif
{0,0,NULL,0}
};
+static struct pid_entry attr_stuff[] = {
+ E(PROC_PID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUSR),
+ E(PROC_PID_ATTR_PREV, "prev", S_IFREG|S_IRUGO|S_IWUSR),
+ E(PROC_PID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUSR),
+ E(PROC_PID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUSR),
+ {0,0,NULL,0}
+};
#undef E
static inline struct task_struct *proc_task(struct inode *inode)
@@ -961,6 +974,175 @@
.permission = proc_permission,
};
+static int proc_attr_readdir(struct file * filp,
+ void * dirent, filldir_t filldir)
+{
+ int i;
+ int pid, ino;
+ struct inode *inode = filp->f_dentry->d_inode;
+ struct pid_entry *p;
+ int ret = 0;
+
+ lock_kernel();
+
+ pid = proc_task(inode)->pid;
+ if (!pid) {
+ ret = -ENOENT;
+ goto out;
+ }
+ i = filp->f_pos;
+ switch (i) {
+ case 0:
+ if (filldir(dirent, ".", 1, i, inode->i_ino, DT_DIR) < 0)
+ goto out;
+ i++;
+ filp->f_pos++;
+ /* fall through */
+ case 1:
+ ino = fake_ino(pid, PROC_PID_INO);
+ if (filldir(dirent, "..", 2, 1, ino, DT_DIR) < 0)
+ goto out;
+ i++;
+ filp->f_pos++;
+ /* fall through */
+ default:
+ i -= 2;
+ if (i>=sizeof(attr_stuff)/sizeof(attr_stuff[0])) {
+ ret = 1;
+ goto out;
+ }
+ p = attr_stuff + i;
+ while (p->name) {
+ if (filldir(dirent, p->name, p->len, filp->f_pos,
+ fake_ino(pid, p->type), p->mode >> 12) < 0)
+ goto out;
+ filp->f_pos++;
+ p++;
+ }
+ }
+
+ ret = 1;
+out:
+ unlock_kernel();
+ return ret;
+}
+
+static ssize_t proc_pid_attr_read(struct file * file, char * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file->f_dentry->d_inode;
+ unsigned long page;
+ ssize_t length;
+ ssize_t end;
+ struct task_struct *task = proc_task(inode);
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+ if (!(page = __get_free_page(GFP_KERNEL)))
+ return -ENOMEM;
+
+ length = security_getprocattr(task,
+ (char*)file->f_dentry->d_name.name,
+ (void*)page, count);
+ if (length < 0) {
+ free_page(page);
+ return length;
+ }
+ /* Static 4kB (or whatever) block capacity */
+ if (*ppos >= length) {
+ free_page(page);
+ return 0;
+ }
+ if (count + *ppos > length)
+ count = length - *ppos;
+ end = count + *ppos;
+ copy_to_user(buf, (char *) page + *ppos, count);
+ *ppos = end;
+ free_page(page);
+ return count;
+}
+
+static ssize_t proc_pid_attr_write(struct file * file, const char * buf,
+ size_t count, loff_t *ppos)
+{
+ struct inode * inode = file->f_dentry->d_inode;
+ char *page;
+ ssize_t length;
+ struct task_struct *task = proc_task(inode);
+
+ if (count > PAGE_SIZE)
+ count = PAGE_SIZE;
+ if (*ppos != 0) {
+ /* No partial writes. */
+ return -EINVAL;
+ }
+ page = (char*)__get_free_page(GFP_USER);
+ if (!page)
+ return -ENOMEM;
+ length = -EFAULT;
+ if (copy_from_user(page, buf, count))
+ goto out;
+
+ length = security_setprocattr(task,
+ (char*)file->f_dentry->d_name.name,
+ (void*)page, count);
+out:
+ free_page((unsigned long) page);
+ return length;
+}
+
+static struct file_operations proc_pid_attr_operations = {
+ .read = proc_pid_attr_read,
+ .write = proc_pid_attr_write,
+};
+
+static struct dentry *proc_attr_lookup(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode;
+ int error;
+ struct task_struct *task = proc_task(dir);
+ struct pid_entry *p;
+ struct proc_inode *ei;
+
+ error = -ENOENT;
+ inode = NULL;
+
+ for (p = attr_stuff; p->name; p++) {
+ if (p->len != dentry->d_name.len)
+ continue;
+ if (!memcmp(dentry->d_name.name, p->name, p->len))
+ break;
+ }
+ if (!p->name)
+ goto out;
+
+ error = -EINVAL;
+ inode = proc_pid_make_inode(dir->i_sb, task, p->type);
+ if (!inode)
+ goto out;
+
+ ei = PROC_I(inode);
+ inode->i_mode = p->mode;
+ inode->i_fop = &proc_pid_attr_operations;
+ dentry->d_op = &pid_dentry_operations;
+ d_add(dentry, inode);
+ if (!proc_task(dentry->d_inode)->pid)
+ d_drop(dentry);
+ return NULL;
+
+out:
+ return ERR_PTR(error);
+}
+
+static struct file_operations proc_attr_operations = {
+ .read = generic_read_dir,
+ .readdir = proc_attr_readdir,
+};
+
+static struct inode_operations proc_attr_inode_operations = {
+ .lookup = proc_attr_lookup,
+};
+
/* SMP-safe */
static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry)
{
@@ -1040,6 +1222,11 @@
break;
case PROC_PID_MOUNTS:
inode->i_fop = &proc_mounts_operations;
+ break;
+ case PROC_PID_ATTR:
+ inode->i_nlink = 2;
+ inode->i_op = &proc_attr_inode_operations;
+ inode->i_fop = &proc_attr_operations;
break;
#ifdef CONFIG_KALLSYMS
case PROC_PID_WCHAN:
Index: linux-2.5/include/linux/security.h
diff -u linux-2.5/include/linux/security.h:1.1.1.2 linux-2.5/include/linux/security.h:1.16
--- linux-2.5/include/linux/security.h:1.1.1.2 Wed Mar 19 09:54:58 2003
+++ linux-2.5/include/linux/security.h Fri Apr 18 11:17:19 2003
@@ -1123,6 +1128,9 @@
void (*d_instantiate) (struct dentry *dentry, struct inode *inode);
+ int (*getprocattr)(struct task_struct *p, char *name, void *value, size_t size);
+ int (*setprocattr)(struct task_struct *p, char *name, void *value, size_t size);
+
#ifdef CONFIG_SECURITY_NETWORK
int (*unix_stream_connect) (struct socket * sock,
struct socket * other, struct sock * newsk);
@@ -1755,6 +1769,16 @@
security_ops->d_instantiate (dentry, inode);
}
+static inline int security_getprocattr(struct task_struct *p, char *name, void *value, size_t size)
+{
+ return security_ops->getprocattr(p, name, value, size);
+}
+
+static inline int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size)
+{
+ return security_ops->setprocattr(p, name, value, size);
+}
+
static inline int security_netlink_send(struct sk_buff * skb)
{
return security_ops->netlink_send(skb);
@@ -2339,6 +2367,16 @@
static inline void security_d_instantiate (struct dentry *dentry, struct inode *inode)
{ }
+
+static inline int security_getprocattr(struct task_struct *p, char *name, void *value, size_t size)
+{
+ return -EINVAL;
+}
+
+static inline int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size)
+{
+ return -EINVAL;
+}
/*
* The netlink capability defaults need to be used inline by default
Index: linux-2.5/security/dummy.c
diff -u linux-2.5/security/dummy.c:1.1.1.2 linux-2.5/security/dummy.c:1.14
--- linux-2.5/security/dummy.c:1.1.1.2 Wed Mar 19 09:59:17 2003
+++ linux-2.5/security/dummy.c Fri Apr 18 11:17:20 2003
@@ -736,6 +741,16 @@
return;
}
+static int dummy_getprocattr(struct task_struct *p, char *name, void *value, size_t size)
+{
+ return -EINVAL;
+}
+
+static int dummy_setprocattr(struct task_struct *p, char *name, void *value, size_t size)
+{
+ return -EINVAL;
+}
+
struct security_operations dummy_security_ops;
@@ -860,6 +876,8 @@
set_to_dummy_if_null(ops, register_security);
set_to_dummy_if_null(ops, unregister_security);
set_to_dummy_if_null(ops, d_instantiate);
+ set_to_dummy_if_null(ops, getprocattr);
+ set_to_dummy_if_null(ops, setprocattr);
#ifdef CONFIG_SECURITY_NETWORK
set_to_dummy_if_null(ops, unix_stream_connect);
set_to_dummy_if_null(ops, unix_may_send);
--
Stephen Smalley <sdsat_private>
National Security Agency
_______________________________________________
linux-security-module mailing list
linux-security-moduleat_private
http://mail.wirex.com/mailman/listinfo/linux-security-module
This archive was generated by hypermail 2b30 : Tue May 06 2003 - 09:15:22 PDT