Introduce cleanup functions for cap_free

[elogind.git] / src / shared / capability.c

diff --git a/src/shared/capability.c b/src/shared/capability.c
index 08b7a209da6bd4674ca5da523c1b0676a7c7c626..f8ee1c6838b63d00d1ad259c95b16dbd79e6e084 100644 (file)
--- a/src/shared/capability.c
+++ b/src/shared/capability.c
@@ -34,28 +34,25 @@
 #include "capability.h"
 #include "util.h"
 #include "log.h"
+#include "fileio.h"
 
 int have_effective_cap(int value) {
-        cap_t cap;
+        _cleanup_cap_free_ cap_t cap;
         cap_flag_value_t fv;
-        int r;
 
         cap = cap_get_proc();
         if (!cap)
                 return -errno;
 
         if (cap_get_flag(cap, value, CAP_EFFECTIVE, &fv) < 0)
-                r = -errno;
+                return -errno;
         else
-                r = fv == CAP_SET;
-
-        cap_free(cap);
-        return r;
+                return fv == CAP_SET;
 }
 
 unsigned long cap_last_cap(void) {
-        static __thread unsigned long saved;
-        static __thread bool valid = false;
+        static thread_local unsigned long saved;
+        static thread_local bool valid = false;
         unsigned long p;
 
         if (valid)
@@ -88,7 +85,7 @@ unsigned long cap_last_cap(void) {
 
 int capability_bounding_set_drop(uint64_t drop, bool right_now) {
         unsigned long i;
-        cap_t after_cap = NULL, temp_cap = NULL;
+        _cleanup_cap_free_ cap_t after_cap = NULL, temp_cap = NULL;
         cap_flag_value_t fv;
         int r;
 
@@ -101,10 +98,8 @@ int capability_bounding_set_drop(uint64_t drop, bool right_now) {
         if (!after_cap)
                 return -errno;
 
-        if (cap_get_flag(after_cap, CAP_SETPCAP, CAP_EFFECTIVE, &fv) < 0) {
-                cap_free(after_cap);
+        if (cap_get_flag(after_cap, CAP_SETPCAP, CAP_EFFECTIVE, &fv) < 0)
                 return -errno;
-        }
 
         if (fv != CAP_SET) {
                 static const cap_value_t v = CAP_SETPCAP;
@@ -136,7 +131,7 @@ int capability_bounding_set_drop(uint64_t drop, bool right_now) {
                                 r = -errno;
                                 goto finish;
                         }
-                        v = i;
+                        v = (cap_value_t) i;
 
                         /* Also drop it from the inheritable set, so
                          * that anything we exec() loses the
@@ -161,13 +156,58 @@ int capability_bounding_set_drop(uint64_t drop, bool right_now) {
         r = 0;
 
 finish:
-        if (temp_cap)
-                cap_free(temp_cap);
+        cap_set_proc(after_cap);
 
-        if (after_cap) {
-                cap_set_proc(after_cap);
-                cap_free(after_cap);
-        }
+        return r;
+}
+
+static int drop_from_file(const char *fn, uint64_t drop) {
+        int r, k;
+        uint32_t hi, lo;
+        uint64_t current, after;
+        char *p;
+
+        r = read_one_line_file(fn, &p);
+        if (r < 0)
+                return r;
+
+        assert_cc(sizeof(hi) == sizeof(unsigned));
+        assert_cc(sizeof(lo) == sizeof(unsigned));
+
+        k = sscanf(p, "%u %u", &lo, &hi);
+        free(p);
+
+        if (k != 2)
+                return -EIO;
+
+        current = (uint64_t) lo | ((uint64_t) hi << 32ULL);
+        after = current & ~drop;
+
+        if (current == after)
+                return 0;
+
+        lo = (unsigned) (after & 0xFFFFFFFFULL);
+        hi = (unsigned) ((after >> 32ULL) & 0xFFFFFFFFULL);
+
+        if (asprintf(&p, "%u %u", lo, hi) < 0)
+                return -ENOMEM;
+
+        r = write_string_file(fn, p);
+        free(p);
+
+        return r;
+}
+
+int capability_bounding_set_drop_usermode(uint64_t drop) {
+        int r;
+
+        r = drop_from_file("/proc/sys/kernel/usermodehelper/inheritable", drop);
+        if (r < 0)
+                return r;
+
+        r = drop_from_file("/proc/sys/kernel/usermodehelper/bset", drop);
+        if (r < 0)
+                return r;
 
         return r;
 }