Hi.


Le lundi 27 décembre 2021, 23:26:29 CET Casey Schaufler a écrit :

On 12/27/2021 12:54 PM, Francis Laniel wrote:

quoted

This array contains the capability names for the given capabilitiy.
For example, index CAP_BPF contains "CAP_BPF".

Signed-off-by: Francis Laniel <redacted>
---

  include/uapi/linux/capability.h |  1 +
  kernel/capability.c             | 45 +++++++++++++++++++++++++++++++++
  2 files changed, 46 insertions(+)

diff --git a/include/uapi/linux/capability.h

b/include/uapi/linux/capability.h index 463d1ba2232a..9646654d5111 100644

--- a/include/uapi/linux/capability.h
+++ b/include/uapi/linux/capability.h

@@ -428,5 +428,6 @@ struct vfs_ns_cap_data {

  #define CAP_TO_INDEX(x)     ((x) >> 5)        /* 1 << 5 == bits in __u32
  */
  #define CAP_TO_MASK(x)      (1 << ((x) & 31)) /* mask for indexed __u32
  */

+extern const char *cap_strings[];

  #endif /* _UAPI_LINUX_CAPABILITY_H */

diff --git a/kernel/capability.c b/kernel/capability.c
index 46a361dde042..5a2e71dcd87b 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c

@@ -15,6 +15,7 @@

  #include <linux/mm.h>
  #include <linux/export.h>
  #include <linux/security.h>

+#include <linux/stringify.h>

  #include <linux/syscalls.h>
  #include <linux/pid_namespace.h>
  #include <linux/user_namespace.h>

@@ -27,6 +28,50 @@

  const kernel_cap_t __cap_empty_set = CAP_EMPTY_SET;
  EXPORT_SYMBOL(__cap_empty_set);

+const char *cap_strings[] = {
+	[CAP_CHOWN] = __stringify_1(CAP_CHOWN),

I may just be old and slow, but why is this better than

	[CAP_CHOWN] = "CAP_CHOWN",

Good catch, thank you for it, I just replaced the __stringify_1() by quotes.
I thought of using __stringify_() because at first I thought of adding a new 
macro which would both define a new capability as well as adding to this array.

But I think it is better to with this simple way rather than doing complicated 
stuff.

quoted

+	[CAP_DAC_OVERRIDE] = __stringify_1(CAP_DAC_OVERRIDE),
+	[CAP_DAC_READ_SEARCH] = __stringify_1(CAP_DAC_READ_SEARCH),
+	[CAP_FOWNER] = __stringify_1(CAP_FOWNER),
+	[CAP_FSETID] = __stringify_1(CAP_FSETID),
+	[CAP_KILL] = __stringify_1(CAP_KILL),
+	[CAP_SETGID] = __stringify_1(CAP_SETGID),
+	[CAP_SETUID] = __stringify_1(CAP_SETUID),
+	[CAP_SETPCAP] = __stringify_1(CAP_SETPCAP),
+	[CAP_LINUX_IMMUTABLE] = __stringify_1(CAP_LINUX_IMMUTABLE),
+	[CAP_NET_BIND_SERVICE] = __stringify_1(CAP_NET_BIND_SERVICE),
+	[CAP_NET_BROADCAST] = __stringify_1(CAP_NET_BROADCAST),
+	[CAP_NET_ADMIN] = __stringify_1(CAP_NET_ADMIN),
+	[CAP_NET_RAW] = __stringify_1(CAP_NET_RAW),
+	[CAP_IPC_LOCK] = __stringify_1(CAP_IPC_LOCK),
+	[CAP_IPC_OWNER] = __stringify_1(CAP_IPC_OWNER),
+	[CAP_SYS_MODULE] = __stringify_1(CAP_SYS_MODULE),
+	[CAP_SYS_RAWIO] = __stringify_1(CAP_SYS_RAWIO),
+	[CAP_SYS_CHROOT] = __stringify_1(CAP_SYS_CHROOT),
+	[CAP_SYS_PTRACE] = __stringify_1(CAP_SYS_PTRACE),
+	[CAP_SYS_PACCT] = __stringify_1(CAP_SYS_PACCT),
+	[CAP_SYS_ADMIN] = __stringify_1(CAP_SYS_ADMIN),
+	[CAP_SYS_BOOT] = __stringify_1(CAP_SYS_BOOT),
+	[CAP_SYS_NICE] = __stringify_1(CAP_SYS_NICE),
+	[CAP_SYS_RESOURCE] = __stringify_1(CAP_SYS_RESOURCE),
+	[CAP_SYS_TIME] = __stringify_1(CAP_SYS_TIME),
+	[CAP_SYS_TTY_CONFIG] = __stringify_1(CAP_SYS_TTY_CONFIG),
+	[CAP_MKNOD] = __stringify_1(CAP_MKNOD),
+	[CAP_LEASE] = __stringify_1(CAP_LEASE),
+	[CAP_AUDIT_WRITE] = __stringify_1(CAP_AUDIT_WRITE),
+	[CAP_AUDIT_CONTROL] = __stringify_1(CAP_AUDIT_CONTROL),
+	[CAP_SETFCAP] = __stringify_1(CAP_SETFCAP),
+	[CAP_MAC_OVERRIDE] = __stringify_1(CAP_MAC_OVERRIDE),
+	[CAP_MAC_ADMIN] = __stringify_1(CAP_MAC_ADMIN),
+	[CAP_SYSLOG] = __stringify_1(CAP_SYSLOG),
+	[CAP_WAKE_ALARM] = __stringify_1(CAP_WAKE_ALARM),
+	[CAP_BLOCK_SUSPEND] = __stringify_1(CAP_BLOCK_SUSPEND),
+	[CAP_AUDIT_READ] = __stringify_1(CAP_AUDIT_READ),
+	[CAP_PERFMON] = __stringify_1(CAP_PERFMON),
+	[CAP_BPF] = __stringify_1(CAP_BPF),
+	[CAP_CHECKPOINT_RESTORE] = __stringify_1(CAP_CHECKPOINT_RESTORE),
+};
+

  int file_caps_enabled = 1;
  
  static int __init file_caps_disable(char *str)