1 // Copyright 2014 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef SANDBOX_LINUX_SERVICES_SYSCALL_WRAPPERS_H_
6 #define SANDBOX_LINUX_SERVICES_SYSCALL_WRAPPERS_H_
7 
8 #include <signal.h>
9 #include <stdint.h>
10 #include <sys/types.h>
11 
12 #include <cstddef>
13 
14 #include "sandbox/sandbox_export.h"
15 
16 struct sock_fprog;
17 struct rlimit64;
18 struct cap_hdr;
19 struct cap_data;
20 
21 namespace sandbox {
22 
23 // Provide direct system call wrappers for a few common system calls.
24 // These are guaranteed to perform a system call and do not rely on things such
25 // as caching the current pid (c.f. getpid()) unless otherwise specified.
26 
27 SANDBOX_EXPORT pid_t sys_getpid(void);
28 
29 SANDBOX_EXPORT pid_t sys_gettid(void);
30 
31 SANDBOX_EXPORT long sys_clone(unsigned long flags);
32 
33 // |regs| is not supported and must be passed as nullptr. |child_stack| must be
34 // nullptr, since otherwise this function cannot safely return. As a
35 // consequence, this function does not support CLONE_VM.
36 SANDBOX_EXPORT long sys_clone(unsigned long flags,
37                               std::nullptr_t child_stack,
38                               pid_t* ptid,
39                               pid_t* ctid,
40                               std::nullptr_t regs);
41 
42 SANDBOX_EXPORT void sys_exit_group(int status);
43 
44 // The official system call takes |args| as void*  (in order to be extensible),
45 // but add more typing for the cases that are currently used.
46 SANDBOX_EXPORT int sys_seccomp(unsigned int operation,
47                                unsigned int flags,
48                                const struct sock_fprog* args);
49 
50 // Some libcs do not expose a prlimit64 wrapper.
51 SANDBOX_EXPORT int sys_prlimit64(pid_t pid,
52                                  int resource,
53                                  const struct rlimit64* new_limit,
54                                  struct rlimit64* old_limit);
55 
56 // Some libcs do not expose capget/capset wrappers. We want to use these
57 // directly in order to avoid pulling in libcap2.
58 SANDBOX_EXPORT int sys_capget(struct cap_hdr* hdrp, struct cap_data* datap);
59 SANDBOX_EXPORT int sys_capset(struct cap_hdr* hdrp,
60                               const struct cap_data* datap);
61 
62 // Some libcs do not expose getresuid/getresgid wrappers.
63 SANDBOX_EXPORT int sys_getresuid(uid_t* ruid, uid_t* euid, uid_t* suid);
64 SANDBOX_EXPORT int sys_getresgid(gid_t* rgid, gid_t* egid, gid_t* sgid);
65 
66 // Some libcs do not expose a chroot wrapper.
67 SANDBOX_EXPORT int sys_chroot(const char* path);
68 
69 // Some libcs do not expose a unshare wrapper.
70 SANDBOX_EXPORT int sys_unshare(int flags);
71 
72 // Some libcs do not expose a sigprocmask. Note that oldset must be a nullptr,
73 // because of some ABI gap between toolchain's and Linux's.
74 SANDBOX_EXPORT int sys_sigprocmask(int how,
75                                    const sigset_t* set,
76                                    std::nullptr_t oldset);
77 
78 // Some libcs do not expose a sigaction().
79 SANDBOX_EXPORT int sys_sigaction(int signum,
80                                  const struct sigaction* act,
81                                  struct sigaction* oldact);
82 
83 }  // namespace sandbox
84 
85 #endif  // SANDBOX_LINUX_SERVICES_SYSCALL_WRAPPERS_H_
86