1 files changed, 220 insertions, 0 deletions

diff --git a/kernel/capability.c b/kernel/capability.c
new file mode 100644
index 000000000000..64db1ee820c2
--- /dev/null
+++ b/kernel/capability.c
@@ -0,0 +1,220 @@
+/*
+ * linux/kernel/capability.c
+ *
+ * Copyright (C) 1997  Andrew Main <zefram@fysh.org>
+ *
+ * Integrated into 2.1.97+,  Andrew G. Morgan <morgan@transmeta.com>
+ * 30 May 2002: Cleanup, Robert M. Love <rml@tech9.net>
+ */ 
+
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/security.h>
+#include <linux/syscalls.h>
+#include <asm/uaccess.h>
+
+unsigned securebits = SECUREBITS_DEFAULT; /* systemwide security settings */
+kernel_cap_t cap_bset = CAP_INIT_EFF_SET;
+
+EXPORT_SYMBOL(securebits);
+EXPORT_SYMBOL(cap_bset);
+
+/*
+ * This lock protects task->cap_* for all tasks including current.
+ * Locking rule: acquire this prior to tasklist_lock.
+ */
+static DEFINE_SPINLOCK(task_capability_lock);
+
+/*
+ * For sys_getproccap() and sys_setproccap(), any of the three
+ * capability set pointers may be NULL -- indicating that that set is
+ * uninteresting and/or not to be changed.
+ */
+
+/*
+ * sys_capget - get the capabilities of a given process.
+ */
+asmlinkage long sys_capget(cap_user_header_t header, cap_user_data_t dataptr)
+{
+     int ret = 0;
+     pid_t pid;
+     __u32 version;
+     task_t *target;
+     struct __user_cap_data_struct data;
+
+     if (get_user(version, &header->version))
+             return -EFAULT;
+
+     if (version != _LINUX_CAPABILITY_VERSION) {
+             if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
+                     return -EFAULT; 
+             return -EINVAL;
+     }
+
+     if (get_user(pid, &header->pid))
+             return -EFAULT;
+
+     if (pid < 0) 
+             return -EINVAL;
+
+     spin_lock(&task_capability_lock);
+     read_lock(&tasklist_lock); 
+
+     if (pid && pid != current->pid) {
+             target = find_task_by_pid(pid);
+             if (!target) {
+                  ret = -ESRCH;
+                  goto out;
+             }
+     } else
+             target = current;
+
+     ret = security_capget(target, &data.effective, &data.inheritable, &data.permitted);
+
+out:
+     read_unlock(&tasklist_lock); 
+     spin_unlock(&task_capability_lock);
+
+     if (!ret && copy_to_user(dataptr, &data, sizeof data))
+          return -EFAULT; 
+
+     return ret;
+}
+
+/*
+ * cap_set_pg - set capabilities for all processes in a given process
+ * group.  We call this holding task_capability_lock and tasklist_lock.
+ */
+static inline int cap_set_pg(int pgrp, kernel_cap_t *effective,
+                              kernel_cap_t *inheritable,
+                              kernel_cap_t *permitted)
+{
+        task_t *g, *target;
+        int ret = -EPERM;
+        int found = 0;
+
+        do_each_task_pid(pgrp, PIDTYPE_PGID, g) {
+                target = g;
+                while_each_thread(g, target) {
+                        if (!security_capset_check(target, effective,
+                                                        inheritable,
+                                                        permitted)) {
+                                security_capset_set(target, effective,
+                                                        inheritable,
+                                                        permitted);
+                                ret = 0;
+                        }
+                        found = 1;
+                }
+        } while_each_task_pid(pgrp, PIDTYPE_PGID, g);
+
+        if (!found)
+             ret = 0;
+        return ret;
+}
+
+/*
+ * cap_set_all - set capabilities for all processes other than init
+ * and self.  We call this holding task_capability_lock and tasklist_lock.
+ */
+static inline int cap_set_all(kernel_cap_t *effective,
+                               kernel_cap_t *inheritable,
+                               kernel_cap_t *permitted)
+{
+     task_t *g, *target;
+     int ret = -EPERM;
+     int found = 0;
+
+     do_each_thread(g, target) {
+             if (target == current || target->pid == 1)
+                     continue;
+             found = 1;
+             if (security_capset_check(target, effective, inheritable,
+                                                permitted))
+                     continue;
+             ret = 0;
+             security_capset_set(target, effective, inheritable, permitted);
+     } while_each_thread(g, target);
+
+     if (!found)
+             ret = 0;
+     return ret;
+}
+
+/*
+ * sys_capset - set capabilities for a given process, all processes, or all
+ * processes in a given process group.
+ *
+ * The restrictions on setting capabilities are specified as:
+ *
+ * [pid is for the 'target' task.  'current' is the calling task.]
+ *
+ * I: any raised capabilities must be a subset of the (old current) permitted
+ * P: any raised capabilities must be a subset of the (old current) permitted
+ * E: must be set to a subset of (new target) permitted
+ */
+asmlinkage long sys_capset(cap_user_header_t header, const cap_user_data_t data)
+{
+     kernel_cap_t inheritable, permitted, effective;
+     __u32 version;
+     task_t *target;
+     int ret;
+     pid_t pid;
+
+     if (get_user(version, &header->version))
+             return -EFAULT; 
+
+     if (version != _LINUX_CAPABILITY_VERSION) {
+             if (put_user(_LINUX_CAPABILITY_VERSION, &header->version))
+                     return -EFAULT; 
+             return -EINVAL;
+     }
+
+     if (get_user(pid, &header->pid))
+             return -EFAULT; 
+
+     if (pid && pid != current->pid && !capable(CAP_SETPCAP))
+             return -EPERM;
+
+     if (copy_from_user(&effective, &data->effective, sizeof(effective)) ||
+         copy_from_user(&inheritable, &data->inheritable, sizeof(inheritable)) ||
+         copy_from_user(&permitted, &data->permitted, sizeof(permitted)))
+             return -EFAULT; 
+
+     spin_lock(&task_capability_lock);
+     read_lock(&tasklist_lock);
+
+     if (pid > 0 && pid != current->pid) {
+          target = find_task_by_pid(pid);
+          if (!target) {
+               ret = -ESRCH;
+               goto out;
+          }
+     } else
+               target = current;
+
+     ret = 0;
+
+     /* having verified that the proposed changes are legal,
+           we now put them into effect. */
+     if (pid < 0) {
+             if (pid == -1)  /* all procs other than current and init */
+                     ret = cap_set_all(&effective, &inheritable, &permitted);
+
+             else            /* all procs in process group */
+                     ret = cap_set_pg(-pid, &effective, &inheritable,
+                                                        &permitted);
+     } else {
+             ret = security_capset_check(target, &effective, &inheritable,
+                                                        &permitted);
+             if (!ret)
+                     security_capset_set(target, &effective, &inheritable,
+                                                        &permitted);
+     }
+
+out:
+     read_unlock(&tasklist_lock);
+     spin_unlock(&task_capability_lock);
+
+     return ret;
+}