text: /*
   * QEMU seccomp mode 2 support with libseccomp
   *
   * Copyright IBM, Corp. 2012
   *
   * Authors:
   *  Eduardo Otubo    <eotubo@br.ibm.com>
   *
   * This work is licensed under the terms of the GNU GPL, version 2.  See
   * the COPYING file in the top-level directory.
   *
   * Contributions after 2012-01-13 are licensed under the terms of the
   * GNU GPL, version 2 or (at your option) any later version.
   */
  #include "qemu/osdep.h"
  #include <seccomp.h>
  #include "sysemu/seccomp.h"
  
  /* For some architectures (notably ARM) cacheflush is not supported until
   * libseccomp 2.2.3, but configure enforces that we are using a more recent
   * version on those hosts, so it is OK for this check to be less strict.
   */
  #if SCMP_VER_MAJOR >= 3
    #define HAVE_CACHEFLUSH
  #elif SCMP_VER_MAJOR == 2 && SCMP_VER_MINOR >= 2
    #define HAVE_CACHEFLUSH
  #endif
  
  struct QemuSeccompSyscall {
      int32_t num;
      uint8_t set;
  };
  
  static const struct QemuSeccompSyscall blacklist[] = {
      /* default set of syscalls to blacklist */
      { SCMP_SYS(reboot),                 QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(swapon),                 QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(swapoff),                QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(syslog),                 QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(mount),                  QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(umount),                 QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(kexec_load),             QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(afs_syscall),            QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(break),                  QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(ftime),                  QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(getpmsg),                QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(gtty),                   QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(lock),                   QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(mpx),                    QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(prof),                   QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(profil),                 QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(putpmsg),                QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(security),               QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(stty),                   QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(tuxcall),                QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(ulimit),                 QEMU_SECCOMP_SET_DEFAULT },
      { SCMP_SYS(vserver),                QEMU_SECCOMP_SET_DEFAULT },
      /* obsolete */
      { SCMP_SYS(readdir),                QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(_sysctl),                QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(bdflush),                QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(create_module),          QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(get_kernel_syms),        QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(query_module),           QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(sgetmask),               QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(ssetmask),               QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(sysfs),                  QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(uselib),                 QEMU_SECCOMP_SET_OBSOLETE },
      { SCMP_SYS(ustat),                  QEMU_SECCOMP_SET_OBSOLETE },
      /* privileged */
      { SCMP_SYS(setuid),                 QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setgid),                 QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setpgid),                QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setsid),                 QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setreuid),               QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setregid),               QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setresuid),              QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setresgid),              QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setfsuid),               QEMU_SECCOMP_SET_PRIVILEGED },
      { SCMP_SYS(setfsgid),               QEMU_SECCOMP_SET_PRIVILEGED },
      /* spawn */
      { SCMP_SYS(fork),                   QEMU_SECCOMP_SET_SPAWN },
      { SCMP_SYS(vfork),                  QEMU_SECCOMP_SET_SPAWN },
      { SCMP_SYS(execve),                 QEMU_SECCOMP_SET_SPAWN },
      /* resource control */
      { SCMP_SYS(getpriority),            QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(setpriority),            QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_setparam),         QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_getparam),         QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_setscheduler),     QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_getscheduler),     QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_setaffinity),      QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_getaffinity),      QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_get_priority_max), QEMU_SECCOMP_SET_RESOURCECTL },
      { SCMP_SYS(sched_get_priority_min), QEMU_SECCOMP_SET_RESOURCECTL },
  };
  
  
  int seccomp_start(uint32_t seccomp_opts)
  {
      int rc = 0;
      unsigned int i = 0;
      scmp_filter_ctx ctx;
  
      ctx = seccomp_init(SCMP_ACT_ALLOW);
      if (ctx == NULL) {
          rc = -1;
          goto seccomp_return;
      }
  
      for (i = 0; i < ARRAY_SIZE(blacklist); i++) {
          if (!(seccomp_opts & blacklist[i].set)) {
              continue;
          }
  
          rc = seccomp_rule_add(ctx, SCMP_ACT_KILL, blacklist[i].num, 0);
          if (rc < 0) {
              goto seccomp_return;
          }
      }
  
      rc = seccomp_load(ctx);
  
    seccomp_return:
      seccomp_release(ctx);
      return rc;
  }
  