src/libsystemd/sd-bus/bus-kernel.c

/***
  This file is part of systemd.

  Copyright 2013 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/

#if HAVE_VALGRIND_MEMCHECK_H
#include <valgrind/memcheck.h>
#endif

#include <fcntl.h>
#include <malloc.h>
#include <sys/mman.h>
#include <sys/prctl.h>

/* When we include libgen.h because we need dirname() we immediately
 * undefine basename() since libgen.h defines it as a macro to the POSIX
 * version which is really broken. We prefer GNU basename(). */
#include <libgen.h>
#undef basename

#include "alloc-util.h"
#include "bus-internal.h"
#include "bus-kernel.h"
#include "bus-label.h"
#include "bus-message.h"
#include "bus-util.h"
#include "capability-util.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-util.h"
#include "memfd-util.h"
#include "parse-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "util.h"

void close_and_munmap(int fd, void *address, size_t size) {
        if (size > 0)
                assert_se(munmap(address, PAGE_ALIGN(size)) >= 0);

        safe_close(fd);
}

void bus_flush_memfd(sd_bus *b) {
        unsigned i;

        assert(b);

        for (i = 0; i < b->n_memfd_cache; i++)
                close_and_munmap(b->memfd_cache[i].fd, b->memfd_cache[i].address, b->memfd_cache[i].mapped);
}

uint64_t attach_flags_to_kdbus(uint64_t mask) {
        uint64_t m = 0;

        if (mask & (SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_SUID|SD_BUS_CREDS_FSUID|
                    SD_BUS_CREDS_GID|SD_BUS_CREDS_EGID|SD_BUS_CREDS_SGID|SD_BUS_CREDS_FSGID))
                m |= KDBUS_ATTACH_CREDS;

        if (mask & (SD_BUS_CREDS_PID|SD_BUS_CREDS_TID|SD_BUS_CREDS_PPID))
                m |= KDBUS_ATTACH_PIDS;

        if (mask & SD_BUS_CREDS_COMM)
                m |= KDBUS_ATTACH_PID_COMM;

        if (mask & SD_BUS_CREDS_TID_COMM)
                m |= KDBUS_ATTACH_TID_COMM;

        if (mask & SD_BUS_CREDS_EXE)
                m |= KDBUS_ATTACH_EXE;

        if (mask & SD_BUS_CREDS_CMDLINE)
                m |= KDBUS_ATTACH_CMDLINE;

        if (mask & (SD_BUS_CREDS_CGROUP|SD_BUS_CREDS_UNIT|SD_BUS_CREDS_USER_UNIT|SD_BUS_CREDS_SLICE|SD_BUS_CREDS_SESSION|SD_BUS_CREDS_OWNER_UID))
                m |= KDBUS_ATTACH_CGROUP;

        if (mask & (SD_BUS_CREDS_EFFECTIVE_CAPS|SD_BUS_CREDS_PERMITTED_CAPS|SD_BUS_CREDS_INHERITABLE_CAPS|SD_BUS_CREDS_BOUNDING_CAPS))
                m |= KDBUS_ATTACH_CAPS;

        if (mask & SD_BUS_CREDS_SELINUX_CONTEXT)
                m |= KDBUS_ATTACH_SECLABEL;

        if (mask & (SD_BUS_CREDS_AUDIT_SESSION_ID|SD_BUS_CREDS_AUDIT_LOGIN_UID))
                m |= KDBUS_ATTACH_AUDIT;

        if (mask & SD_BUS_CREDS_WELL_KNOWN_NAMES)
                m |= KDBUS_ATTACH_NAMES;

        if (mask & SD_BUS_CREDS_DESCRIPTION)
                m |= KDBUS_ATTACH_CONN_DESCRIPTION;

        if (mask & SD_BUS_CREDS_SUPPLEMENTARY_GIDS)
                m |= KDBUS_ATTACH_AUXGROUPS;

        return m;
}