Linux-Clone/Clone.xs

#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"

#include <sys/errno.h>
#include <sys/mman.h>

#undef _GNU_SOURCE
#define _GNU_SOURCE
#include <sched.h>
#include <unistd.h>
#include <sys/syscall.h>

#include <sched.h>

#include <sys/ioctl.h>
#include <net/if.h>

#include <linux/nsfs.h>
#include <linux/kcmp.h>

/* kcmp.h does not define symbols, so there is no way to detect preesence of enum */
/* members, so we just hardcode new symbols here. */
#ifndef KCMP_EPOLL_TFD
  #define KCMP_EPOLL_TFD 7
#endif

#ifdef __has_include
  #if !__has_include("linux/kcmp.h") // use "" as GCC wrongly expands macros
    #undef SYS_kcmp
  #endif
#endif

#ifdef SYS_kcmp
  #include "linux/kcmp.h"
  #define kcmp(pid1,pid2,type,idx1,idx2) \
    syscall (SYS_kcmp, (pid_t)pid1, (pid_t)pid2, \
             (int)type, (unsigned long)idx1, (unsigned long)idx2)
#else
  #define kcmp(pid1,pid2,type,idx1,idx2) \
    (errno = ENOSYS, -1)
#endif

/* from schmorp.h */
static int
s_fileno (SV *fh, int wr)
{
  dTHX;
  SvGETMAGIC (fh);

  if (SvROK (fh))
    {
      fh = SvRV (fh);
      SvGETMAGIC (fh);
    }

  if (SvTYPE (fh) == SVt_PVGV)
    return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));

  if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
    return SvIV (fh);

  return -1;
}

static int
clone_cb (void *arg)
{
  dSP;

  PUSHMARK (SP);

  PUTBACK;
  int count = call_sv (sv_2mortal ((SV *)arg), G_SCALAR);
  SPAGAIN;
  int retval = count ? SvIV (POPs) : 0;
  PUTBACK;

  return retval;
}

MODULE = Linux::Clone           PACKAGE = Linux::Clone

PROTOTYPES: ENABLE

BOOT:
  HV *stash = gv_stashpv ("Linux::Clone", 1);

  static const struct {
    const char *name;
    IV iv;
  } *civ, const_iv[] = {
#   define const_iv(name)       { # name, (IV)name },
#   define const_iv_clone(name) { # name, (IV) CLONE_ ## name },
#   ifdef CSIGNAL
      const_iv (CSIGNAL)
#   endif
#   ifdef CLONE_FILES
      const_iv_clone (FILES)
#   endif
#   ifdef CLONE_FS
      const_iv_clone (FS)
#   endif
#   ifdef CLONE_NEWNS
      const_iv_clone (NEWNS)
#   endif
#   ifdef CLONE_VM
      const_iv_clone (VM)
#   endif
#   ifdef CLONE_THREAD
      const_iv_clone (THREAD)
#   endif
#   ifdef CLONE_SIGHAND
      const_iv_clone (SIGHAND)
#   endif
#   ifdef CLONE_SYSVSEM
      const_iv_clone (SYSVSEM)
#   endif
#   ifdef CLONE_NEWUTS
      const_iv_clone (NEWUTS)
#   endif
#   ifdef CLONE_NEWIPC
      const_iv_clone (NEWIPC)
#   endif
#   ifdef CLONE_NEWNET
      const_iv_clone (NEWNET)
#   endif
#   ifdef CLONE_NEWTIME
      x
      const_iv_clone (NEWTIME)
#   endif
#   ifdef CLONE_PTRACE
      const_iv_clone (PTRACE)
#   endif
#   ifdef CLONE_VFORK
      const_iv_clone (VFORK)
#   endif
#   ifdef CLONE_SETTLS
      const_iv_clone (SETTLS)
#   endif
#   ifdef CLONE_PARENT_SETTID
      const_iv_clone (PARENT_SETTID)
#   endif
#   ifdef CLONE_CHILD_CLEARTID
      const_iv_clone (CHILD_CLEARTID)
#   endif
#   ifdef CLONE_DETACHED
      const_iv_clone (DETACHED)
#   endif
#   ifdef CLONE_UNTRACED
      const_iv_clone (UNTRACED)
#   endif
#   ifdef CLONE_CHILD_SETTID
      const_iv_clone (CHILD_SETTID)
#   endif
#   ifdef CLONE_NEWUSER
      const_iv_clone (NEWUSER)
#   endif
#   ifdef CLONE_NEWPID
      const_iv_clone (NEWPID)
#   endif
#   ifdef CLONE_IO
      const_iv_clone (IO)
#   endif
#   ifdef CLONE_NEWCGROUP
      const_iv_clone (NEWCGROUP)
#   endif
#   ifdef CLONE_PIDFD
      const_iv_clone (PIDFD)
#   endif
#   ifdef SYS_kcmp
      const_iv (KCMP_FILE)
      const_iv (KCMP_VM)
      const_iv (KCMP_FILES)
      const_iv (KCMP_FS)
      const_iv (KCMP_SIGHAND)
      const_iv (KCMP_IO)
      const_iv (KCMP_SYSVSEM)
      const_iv (KCMP_EPOLL_TFD)
#   endif
#   ifdef NS_GET_USERNS
      const_iv (NS_GET_USERNS)
#   endif
#   ifdef NS_GET_PARENT
      const_iv (NS_GET_PARENT)
#   endif
#   ifdef NS_GET_NSTYPE
      const_iv (NS_GET_NSTYPE)
#   endif
#   ifdef NS_OWNER_UID
      const_iv (NS_OWNER_UID
#   endif
  };

  for (civ = const_iv + sizeof (const_iv) / sizeof (const_iv [0]); civ > const_iv; civ--)
    newCONSTSUB (stash, (char *)civ[-1].name, newSViv (civ[-1].iv));

int
clone (SV *sub, IV stacksize, int flags, SV *ptid = 0, SV *tls = &PL_sv_undef)
        CODE:
{
        if (!stacksize)
          stacksize = 4 << 20;

        pid_t ptid_;
        char *stack_ptr = mmap (0, stacksize, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_GROWSDOWN | MAP_STACK, -1, 0);

        #ifndef __hppa
          stack_ptr += stacksize - 16; /* be safe and put the sp at 16 bytes below the end */
        #endif

        RETVAL = -1;
        if (stack_ptr != (void *)-1)
          {
            SV *my_sub = newSVsv (sub);
            
            RETVAL = clone (clone_cb, (void *)stack_ptr, flags, (void *)my_sub, &ptid, SvOK (tls) ? SvPV_nolen (tls) : 0, 0);

            if (ptid) sv_setiv (ptid, (IV)ptid_);

            if ((flags & (CLONE_VM | CLONE_VFORK)) != CLONE_VM)
              {
                int old_errno = errno;
                munmap (stack_ptr, stacksize);
                errno = old_errno;
              }
          }
}
        OUTPUT: RETVAL

int
unshare (int flags)
        PROTOTYPE: @

int
setns (SV *fh_or_fd, int nstype = 0)
        C_ARGS: s_fileno (fh_or_fd, 0), nstype

int
pivot_root (SV *new_root, SV *old_root)
        CODE:
        RETVAL = syscall (SYS_pivot_root,
                          (const char *)SvPVbyte_nolen (new_root),
                          (const char *)SvPVbyte_nolen (old_root));
        OUTPUT: RETVAL

int
kcmp (IV pid1, IV pid2, IV type, UV idx1 = 0, UV idx2 = 0)

int
siocsifflags (char *ifname, U32 flags = IFF_UP)
        CODE:
{
        int saved_errno;
        struct ifreq ifr;
        int fd = socket (AF_INET, SOCK_DGRAM, 0);
        strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
        RETVAL = ioctl (fd, SIOCSIFFLAGS, &ifr);
        saved_errno = errno;
        close (fd);
        errno = saved_errno;
}
        OUTPUT: RETVAL

Revision:	1.9
Committed:	Tue Sep 6 10:57:01 2022 UTC (20 months, 1 week ago) by root
Branch:	MAIN
CVS Tags:	rel-1_3
Changes since 1.8:	+1 -0 lines
Log Message:	1.3
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5			#include <sys/errno.h>
6			#include <sys/mman.h>
7
8			#undef _GNU_SOURCE
9			#define _GNU_SOURCE
10			#include <sched.h>
11	root	1.3	#include <unistd.h>
12			#include <sys/syscall.h>
13
14	root	1.6	#include <sched.h>
15
16			#include <sys/ioctl.h>
17			#include <net/if.h>
18
19	root	1.7	#include <linux/nsfs.h>
20	root	1.8	#include <linux/kcmp.h>
21
22			/* kcmp.h does not define symbols, so there is no way to detect preesence of enum */
23			/* members, so we just hardcode new symbols here. */
24			#ifndef KCMP_EPOLL_TFD
25			#define KCMP_EPOLL_TFD 7
26			#endif
27	root	1.7
28	root	1.4	#ifdef __has_include
29			#if !__has_include("linux/kcmp.h") // use "" as GCC wrongly expands macros
30			#undef SYS_kcmp
31			#endif
32			#endif
33
34	root	1.3	#ifdef SYS_kcmp
35	root	1.4	#include "linux/kcmp.h"
36	root	1.3	#define kcmp(pid1,pid2,type,idx1,idx2) \
37			syscall (SYS_kcmp, (pid_t)pid1, (pid_t)pid2, \
38			(int)type, (unsigned long)idx1, (unsigned long)idx2)
39			#else
40			#define kcmp(pid1,pid2,type,idx1,idx2) \
41			(errno = ENOSYS, -1)
42			#endif
43	root	1.1
44	root	1.2	/* from schmorp.h */
45			static int
46			s_fileno (SV *fh, int wr)
47			{
48			dTHX;
49			SvGETMAGIC (fh);
50
51			if (SvROK (fh))
52			{
53			fh = SvRV (fh);
54			SvGETMAGIC (fh);
55			}
56
57			if (SvTYPE (fh) == SVt_PVGV)
58			return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));
59
60			if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
61			return SvIV (fh);
62
63			return -1;
64			}
65
66	root	1.1	static int
67			clone_cb (void *arg)
68			{
69			dSP;
70
71			PUSHMARK (SP);
72
73			PUTBACK;
74			int count = call_sv (sv_2mortal ((SV *)arg), G_SCALAR);
75			SPAGAIN;
76			int retval = count ? SvIV (POPs) : 0;
77			PUTBACK;
78
79			return retval;
80			}
81
82			MODULE = Linux::Clone PACKAGE = Linux::Clone
83
84			PROTOTYPES: ENABLE
85
86			BOOT:
87			HV *stash = gv_stashpv ("Linux::Clone", 1);
88
89			static const struct {
90			const char *name;
91			IV iv;
92			} *civ, const_iv[] = {
93	root	1.4	# define const_iv(name) { # name, (IV)name },
94			# define const_iv_clone(name) { # name, (IV) CLONE_ ## name },
95	root	1.6	# ifdef CSIGNAL
96			const_iv (CSIGNAL)
97			# endif
98	root	1.1	# ifdef CLONE_FILES
99	root	1.4	const_iv_clone (FILES)
100	root	1.1	# endif
101			# ifdef CLONE_FS
102	root	1.4	const_iv_clone (FS)
103	root	1.1	# endif
104			# ifdef CLONE_NEWNS
105	root	1.4	const_iv_clone (NEWNS)
106	root	1.1	# endif
107			# ifdef CLONE_VM
108	root	1.4	const_iv_clone (VM)
109	root	1.1	# endif
110			# ifdef CLONE_THREAD
111	root	1.4	const_iv_clone (THREAD)
112	root	1.1	# endif
113			# ifdef CLONE_SIGHAND
114	root	1.4	const_iv_clone (SIGHAND)
115	root	1.1	# endif
116			# ifdef CLONE_SYSVSEM
117	root	1.4	const_iv_clone (SYSVSEM)
118	root	1.1	# endif
119			# ifdef CLONE_NEWUTS
120	root	1.4	const_iv_clone (NEWUTS)
121	root	1.1	# endif
122			# ifdef CLONE_NEWIPC
123	root	1.4	const_iv_clone (NEWIPC)
124	root	1.1	# endif
125			# ifdef CLONE_NEWNET
126	root	1.4	const_iv_clone (NEWNET)
127	root	1.1	# endif
128	root	1.8	# ifdef CLONE_NEWTIME
129			x
130			const_iv_clone (NEWTIME)
131			# endif
132	root	1.1	# ifdef CLONE_PTRACE
133	root	1.4	const_iv_clone (PTRACE)
134	root	1.1	# endif
135			# ifdef CLONE_VFORK
136	root	1.4	const_iv_clone (VFORK)
137	root	1.1	# endif
138			# ifdef CLONE_SETTLS
139	root	1.4	const_iv_clone (SETTLS)
140	root	1.1	# endif
141			# ifdef CLONE_PARENT_SETTID
142	root	1.4	const_iv_clone (PARENT_SETTID)
143	root	1.1	# endif
144			# ifdef CLONE_CHILD_CLEARTID
145	root	1.4	const_iv_clone (CHILD_CLEARTID)
146	root	1.1	# endif
147			# ifdef CLONE_DETACHED
148	root	1.4	const_iv_clone (DETACHED)
149	root	1.1	# endif
150			# ifdef CLONE_UNTRACED
151	root	1.4	const_iv_clone (UNTRACED)
152	root	1.1	# endif
153			# ifdef CLONE_CHILD_SETTID
154	root	1.4	const_iv_clone (CHILD_SETTID)
155	root	1.1	# endif
156			# ifdef CLONE_NEWUSER
157	root	1.4	const_iv_clone (NEWUSER)
158	root	1.1	# endif
159			# ifdef CLONE_NEWPID
160	root	1.4	const_iv_clone (NEWPID)
161	root	1.1	# endif
162			# ifdef CLONE_IO
163	root	1.4	const_iv_clone (IO)
164	root	1.1	# endif
165	root	1.2	# ifdef CLONE_NEWCGROUP
166	root	1.4	const_iv_clone (NEWCGROUP)
167	root	1.3	# endif
168	root	1.5	# ifdef CLONE_PIDFD
169			const_iv_clone (PIDFD)
170			# endif
171	root	1.3	# ifdef SYS_kcmp
172			const_iv (KCMP_FILE)
173			const_iv (KCMP_VM)
174			const_iv (KCMP_FILES)
175			const_iv (KCMP_FS)
176			const_iv (KCMP_SIGHAND)
177			const_iv (KCMP_IO)
178			const_iv (KCMP_SYSVSEM)
179	root	1.8	const_iv (KCMP_EPOLL_TFD)
180	root	1.2	# endif
181	root	1.7	# ifdef NS_GET_USERNS
182			const_iv (NS_GET_USERNS)
183			# endif
184			# ifdef NS_GET_PARENT
185			const_iv (NS_GET_PARENT)
186			# endif
187			# ifdef NS_GET_NSTYPE
188			const_iv (NS_GET_NSTYPE)
189			# endif
190			# ifdef NS_OWNER_UID
191			const_iv (NS_OWNER_UID
192			# endif
193	root	1.1	};
194
195			for (civ = const_iv + sizeof (const_iv) / sizeof (const_iv [0]); civ > const_iv; civ--)
196			newCONSTSUB (stash, (char *)civ[-1].name, newSViv (civ[-1].iv));
197
198			int
199			clone (SV sub, IV stacksize, int flags, SV ptid = 0, SV *tls = &PL_sv_undef)
200			CODE:
201			{
202	root	1.2	if (!stacksize)
203	root	1.1	stacksize = 4 << 20;
204
205			pid_t ptid_;
206			char *stack_ptr = mmap (0, stacksize, PROT_EXEC \| PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANONYMOUS \| MAP_GROWSDOWN \| MAP_STACK, -1, 0);
207
208			#ifndef __hppa
209			stack_ptr += stacksize - 16; /* be safe and put the sp at 16 bytes below the end */
210			#endif
211
212			RETVAL = -1;
213			if (stack_ptr != (void *)-1)
214			{
215			SV *my_sub = newSVsv (sub);
216
217			RETVAL = clone (clone_cb, (void )stack_ptr, flags, (void )my_sub, &ptid, SvOK (tls) ? SvPV_nolen (tls) : 0, 0);
218
219			if (ptid) sv_setiv (ptid, (IV)ptid_);
220
221			if ((flags & (CLONE_VM \| CLONE_VFORK)) != CLONE_VM)
222			{
223			int old_errno = errno;
224			munmap (stack_ptr, stacksize);
225			errno = old_errno;
226			}
227			}
228			}
229	root	1.6	OUTPUT: RETVAL
230	root	1.1
231	root	1.2	int
232			unshare (int flags)
233	root	1.9	PROTOTYPE: @
234	root	1.2
235			int
236			setns (SV *fh_or_fd, int nstype = 0)
237			C_ARGS: s_fileno (fh_or_fd, 0), nstype
238	root	1.3
239			int
240			pivot_root (SV new_root, SV old_root)
241			CODE:
242			RETVAL = syscall (SYS_pivot_root,
243			(const char *)SvPVbyte_nolen (new_root),
244			(const char *)SvPVbyte_nolen (old_root));
245	root	1.6	OUTPUT: RETVAL
246	root	1.3
247			int
248			kcmp (IV pid1, IV pid2, IV type, UV idx1 = 0, UV idx2 = 0)
249
250	root	1.6	int
251			siocsifflags (char *ifname, U32 flags = IFF_UP)
252			CODE:
253			{
254			int saved_errno;
255			struct ifreq ifr;
256			int fd = socket (AF_INET, SOCK_DGRAM, 0);
257			strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
258			RETVAL = ioctl (fd, SIOCSIFFLAGS, &ifr);
259			saved_errno = errno;
260			close (fd);
261			errno = saved_errno;
262			}
263			OUTPUT: RETVAL
264