Implement full decoding of 64-bit capabilities
Unlike v1 capabilities which are 32-bit, v2 and v3 are 64-bit, but
before this change only lower 32 capability bits were decoded for
v2 and v3.
* xlat/capabilities1.in: New file.
* capability.c: Define v2/v3 CAP_* constants.
Include xlat/capabilities1.h.
(get_cap_header): New function.
(print_cap_header): Update to use get_cap_header result.
(print_cap_data): Decoder higher capability bits for v2 and v3.
(sys_capget, sys_capset): Use get_cap_header, update print_cap_header
and print_cap_data calls.
* tests/caps.c: New file.
* tests/caps.awk: New file.
* tests/caps.test: New test.
* tests/Makefile.am (CHECK_PROGRAMS): Add caps.
(TESTS): Add caps.test.
(EXTRA_DIST): Add caps.awk.
diff --git a/capability.c b/capability.c
index 3c7666f..af4dffe 100644
--- a/capability.c
+++ b/capability.c
@@ -1,5 +1,6 @@
#include "defs.h"
+/* these constants are the same as in <linux/capability.h> */
enum {
CAP_CHOWN,
CAP_DAC_OVERRIDE,
@@ -37,6 +38,19 @@
#include "xlat/capabilities.h"
+/* these constants are CAP_TO_INDEX'ed constants from <linux/capability.h> */
+enum {
+ CAP_MAC_OVERRIDE,
+ CAP_MAC_ADMIN,
+ CAP_SYSLOG,
+ CAP_WAKE_ALARM,
+ CAP_BLOCK_SUSPEND,
+ CAP_AUDIT_READ
+};
+
+#include "xlat/capabilities1.h"
+
+/* these constants are the same as in <linux/capability.h> */
enum {
_LINUX_CAPABILITY_VERSION_1 = 0x19980330,
_LINUX_CAPABILITY_VERSION_2 = 0x20071026,
@@ -56,58 +70,101 @@
uint32_t inheritable;
} *cap_user_data_t;
-static void
-print_cap_header(struct tcb *tcp, unsigned long addr)
+static cap_user_header_t
+get_cap_header(struct tcb *tcp, unsigned long addr)
{
- union { cap_user_header_t p; long *a; char *c; } arg;
- long a[sizeof(*arg.p) / sizeof(long) + 1];
- arg.a = a;
+ static struct user_cap_header_struct header;
- if (!addr)
+ if (!addr || !verbose(tcp))
+ return NULL;
+
+ if (umove(tcp, addr, &header) < 0)
+ return NULL;
+
+ return &header;
+}
+
+static void
+print_cap_header(struct tcb *tcp, unsigned long addr, cap_user_header_t h)
+{
+ if (!addr) {
tprints("NULL");
- else if (!verbose(tcp) ||
- umoven(tcp, addr, sizeof(*arg.p), arg.c) < 0)
+ return;
+ }
+
+ if (!h) {
tprintf("%#lx", addr);
- else {
- tprints("{");
- printxval(cap_version, arg.p->version,
- "_LINUX_CAPABILITY_VERSION_???");
- tprintf(", %d}", arg.p->pid);
+ return;
+ }
+
+ tprints("{");
+ printxval(cap_version, h->version,
+ "_LINUX_CAPABILITY_VERSION_???");
+ tprintf(", %d}", h->pid);
+}
+
+static void
+print_cap_bits(const uint32_t lo, const uint32_t hi)
+{
+ if (lo || !hi)
+ printflags(capabilities, lo, "CAP_???");
+
+ if (hi) {
+ if (lo)
+ tprints("|");
+ printflags(capabilities1, hi, "CAP_???");
}
}
static void
-print_cap_data(struct tcb *tcp, unsigned long addr)
+print_cap_data(struct tcb *tcp, unsigned long addr, const cap_user_header_t h)
{
- union { cap_user_data_t p; long *a; char *c; } arg;
- long a[sizeof(*arg.p) / sizeof(long) + 1];
- arg.a = a;
+ struct user_cap_data_struct data[2];
+ unsigned int len;
- if (!addr)
+ if (!addr) {
tprints("NULL");
- else if (!verbose(tcp) ||
- (exiting(tcp) && syserror(tcp)) ||
- umoven(tcp, addr, sizeof(*arg.p), arg.c) < 0)
- tprintf("%#lx", addr);
- else {
- tprints("{");
- printflags(capabilities, arg.p->effective, "CAP_???");
- tprints(", ");
- printflags(capabilities, arg.p->permitted, "CAP_???");
- tprints(", ");
- printflags(capabilities, arg.p->inheritable, "CAP_???");
- tprints("}");
+ return;
}
+
+ if (!h || !verbose(tcp) ||
+ (exiting(tcp) && syserror(tcp))) {
+ tprintf("%#lx", addr);
+ return;
+ }
+
+ if (_LINUX_CAPABILITY_VERSION_2 == h->version ||
+ _LINUX_CAPABILITY_VERSION_3 == h->version)
+ len = 2;
+ else
+ len = 1;
+
+ if (umoven(tcp, addr, len * sizeof(data[0]), (char *) data) < 0) {
+ tprintf("%#lx", addr);
+ return;
+ }
+
+ tprints("{");
+ print_cap_bits(data[0].effective, len > 1 ? data[1].effective : 0);
+ tprints(", ");
+ print_cap_bits(data[0].permitted, len > 1 ? data[1].permitted : 0);
+ tprints(", ");
+ print_cap_bits(data[0].inheritable, len > 1 ? data[1].inheritable : 0);
+ tprints("}");
}
int
sys_capget(struct tcb *tcp)
{
+ cap_user_header_t h;
+
if (entering(tcp)) {
- print_cap_header(tcp, tcp->u_arg[0]);
+ h = get_cap_header(tcp, tcp->u_arg[0]);
+ print_cap_header(tcp, tcp->u_arg[0], h);
tprints(", ");
} else {
- print_cap_data(tcp, tcp->u_arg[1]);
+ h = syserror(tcp) ? NULL : get_cap_header(tcp, tcp->u_arg[0]);
+ print_cap_data(tcp, tcp->u_arg[1], h);
}
return 0;
}
@@ -116,9 +173,10 @@
sys_capset(struct tcb *tcp)
{
if (entering(tcp)) {
- print_cap_header(tcp, tcp->u_arg[0]);
+ cap_user_header_t h = get_cap_header(tcp, tcp->u_arg[0]);
+ print_cap_header(tcp, tcp->u_arg[0], h);
tprints(", ");
- print_cap_data(tcp, tcp->u_arg[1]);
+ print_cap_data(tcp, tcp->u_arg[1], h);
}
return 0;
}