core: drop Capabilities= setting

The setting is hardly useful (since its effect is generally reduced to zero due
to file system caps), and with the advent of ambient caps an actually useful
replacement exists, hence let's get rid of this.

I am pretty sure this was unused and our man page already recommended against
its use, hence this should be a safe thing to remove.

1 files changed, 3 insertions, 59 deletions

diff --git a/src/core/execute.c b/src/core/execute.c
index 30f7e05b90..184c72dbe7 100644
--- a/src/core/execute.c
+++ b/src/core/execute.c
@@ -746,10 +746,10 @@ static int enforce_groups(const ExecContext *context, const char *username, gid_
 static int enforce_user(const ExecContext *context, uid_t uid) {
         assert(context);
 
-        /* Sets (but doesn't lookup) the uid and make sure we keep the
+        /* Sets (but doesn't look up) the uid and make sure we keep the
          * capabilities while doing so. */
 
-        if (context->capabilities || context->capability_ambient_set != 0) {
+        if (context->capability_ambient_set != 0) {
 
                 /* First step: If we need to keep capabilities but
                  * drop privileges we need to make sure we keep our
@@ -761,31 +761,9 @@ static int enforce_user(const ExecContext *context, uid_t uid) {
                                 if (prctl(PR_SET_SECUREBITS, sb) < 0)
                                         return -errno;
                 }
-
-                /* Second step: set the capabilities. This will reduce
-                 * the capabilities to the minimum we need. */
-
-                if (context->capabilities) {
-                        _cleanup_cap_free_ cap_t d = NULL;
-                        static const cap_value_t bits[] = {
-                                CAP_SETUID,   /* Necessary so that we can run setresuid() below */
-                                CAP_SETPCAP   /* Necessary so that we can set PR_SET_SECUREBITS later on */
-                        };
-
-                        d = cap_dup(context->capabilities);
-                        if (!d)
-                                return -errno;
-
-                        if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 ||
-                            cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0)
-                                return -errno;
-
-                        if (cap_set_proc(d) < 0)
-                                return -errno;
-                }
         }
 
-        /* Third step: actually set the uids */
+        /* Second step: actually set the uids */
         if (setresuid(uid, uid, uid) < 0)
                 return -errno;
 
@@ -1874,21 +1852,6 @@ static int exec_child(
                                 *exit_status = EXIT_CAPABILITIES;
                                 return r;
                         }
-
-                        if (context->capabilities) {
-
-                                /* The capabilities in ambient set need to be also in the inherited
-                                 * set. If they aren't, trying to get them will fail. Add the ambient
-                                 * set inherited capabilities to the capability set in the context.
-                                 * This is needed because if capabilities are set (using "Capabilities="
-                                 * keyword), they will override whatever we set now. */
-
-                                r = capability_update_inherited_set(context->capabilities, context->capability_ambient_set);
-                                if (r < 0) {
-                                        *exit_status = EXIT_CAPABILITIES;
-                                        return r;
-                                }
-                        }
                 }
 
                 if (context->user) {
@@ -1927,12 +1890,6 @@ static int exec_child(
                                 return -errno;
                         }
 
-                if (context->capabilities)
-                        if (cap_set_proc(context->capabilities) < 0) {
-                                *exit_status = EXIT_CAPABILITIES;
-                                return -errno;
-                        }
-
                 if (context->no_new_privileges)
                         if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) < 0) {
                                 *exit_status = EXIT_NO_NEW_PRIVILEGES;
@@ -2175,11 +2132,6 @@ void exec_context_done(ExecContext *c) {
 
         c->pam_name = mfree(c->pam_name);
 
-        if (c->capabilities) {
-                cap_free(c->capabilities);
-                c->capabilities = NULL;
-        }
-
         c->read_only_dirs = strv_free(c->read_only_dirs);
         c->read_write_dirs = strv_free(c->read_write_dirs);
         c->inaccessible_dirs = strv_free(c->inaccessible_dirs);
@@ -2538,14 +2490,6 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
                         prefix, strna(lvl_str));
         }
 
-        if (c->capabilities) {
-                _cleanup_cap_free_charp_ char *t;
-
-                t = cap_to_text(c->capabilities, NULL);
-                if (t)
-                        fprintf(f, "%sCapabilities: %s\n", prefix, t);
-        }
-
         if (c->secure_bits)
                 fprintf(f, "%sSecure Bits:%s%s%s%s%s%s\n",
                         prefix,