cvsroot/Linux-Clone/Clone.xs

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

#include <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>

#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

/* 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

/* 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
      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:	1.12
Committed:	Wed Apr 8 20:28:06 2026 UTC (5 months, 2 weeks ago) by root
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.11:	+1 -1 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	#include "EXTERN.h"
2			#include "perl.h"
3			#include "XSUB.h"
4
5	root	1.12	#include <errno.h>
6	root	1.1	#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	1.4	#ifdef __has_include
20			#if !__has_include("linux/kcmp.h") // use "" as GCC wrongly expands macros
21			#undef SYS_kcmp
22			#endif
23			#endif
24
25	root	1.3	#ifdef SYS_kcmp
26	root	1.4	#include "linux/kcmp.h"
27	root	1.3	#define kcmp(pid1,pid2,type,idx1,idx2) \
28			syscall (SYS_kcmp, (pid_t)pid1, (pid_t)pid2, \
29			(int)type, (unsigned long)idx1, (unsigned long)idx2)
30			#else
31			#define kcmp(pid1,pid2,type,idx1,idx2) \
32			(errno = ENOSYS, -1)
33			#endif
34	root	1.1
35	root	1.11	/* kcmp.h does not define symbols, so there is no way to detect preesence of enum */
36			/* members, so we just hardcode new symbols here. */
37			#ifndef KCMP_EPOLL_TFD
38			#define KCMP_EPOLL_TFD 7
39			#endif
40
41	root	1.2	/* from schmorp.h */
42			static int
43			s_fileno (SV *fh, int wr)
44			{
45			dTHX;
46			SvGETMAGIC (fh);
47
48			if (SvROK (fh))
49			{
50			fh = SvRV (fh);
51			SvGETMAGIC (fh);
52			}
53
54			if (SvTYPE (fh) == SVt_PVGV)
55			return PerlIO_fileno (wr ? IoOFP (sv_2io (fh)) : IoIFP (sv_2io (fh)));
56
57			if (SvOK (fh) && (SvIV (fh) >= 0) && (SvIV (fh) < 0x7fffffffL))
58			return SvIV (fh);
59
60			return -1;
61			}
62
63	root	1.1	static int
64			clone_cb (void *arg)
65			{
66			dSP;
67
68			PUSHMARK (SP);
69
70			PUTBACK;
71			int count = call_sv (sv_2mortal ((SV *)arg), G_SCALAR);
72			SPAGAIN;
73			int retval = count ? SvIV (POPs) : 0;
74			PUTBACK;
75
76			return retval;
77			}
78
79			MODULE = Linux::Clone PACKAGE = Linux::Clone
80
81			PROTOTYPES: ENABLE
82
83			BOOT:
84			HV *stash = gv_stashpv ("Linux::Clone", 1);
85
86			static const struct {
87			const char *name;
88			IV iv;
89			} *civ, const_iv[] = {
90	root	1.4	# define const_iv(name) { # name, (IV)name },
91			# define const_iv_clone(name) { # name, (IV) CLONE_ ## name },
92	root	1.6	# ifdef CSIGNAL
93			const_iv (CSIGNAL)
94			# endif
95	root	1.1	# ifdef CLONE_FILES
96	root	1.4	const_iv_clone (FILES)
97	root	1.1	# endif
98			# ifdef CLONE_FS
99	root	1.4	const_iv_clone (FS)
100	root	1.1	# endif
101			# ifdef CLONE_NEWNS
102	root	1.4	const_iv_clone (NEWNS)
103	root	1.1	# endif
104			# ifdef CLONE_VM
105	root	1.4	const_iv_clone (VM)
106	root	1.1	# endif
107			# ifdef CLONE_THREAD
108	root	1.4	const_iv_clone (THREAD)
109	root	1.1	# endif
110			# ifdef CLONE_SIGHAND
111	root	1.4	const_iv_clone (SIGHAND)
112	root	1.1	# endif
113			# ifdef CLONE_SYSVSEM
114	root	1.4	const_iv_clone (SYSVSEM)
115	root	1.1	# endif
116			# ifdef CLONE_NEWUTS
117	root	1.4	const_iv_clone (NEWUTS)
118	root	1.1	# endif
119			# ifdef CLONE_NEWIPC
120	root	1.4	const_iv_clone (NEWIPC)
121	root	1.1	# endif
122			# ifdef CLONE_NEWNET
123	root	1.4	const_iv_clone (NEWNET)
124	root	1.1	# endif
125	root	1.8	# ifdef CLONE_NEWTIME
126			const_iv_clone (NEWTIME)
127			# endif
128	root	1.1	# ifdef CLONE_PTRACE
129	root	1.4	const_iv_clone (PTRACE)
130	root	1.1	# endif
131			# ifdef CLONE_VFORK
132	root	1.4	const_iv_clone (VFORK)
133	root	1.1	# endif
134			# ifdef CLONE_SETTLS
135	root	1.4	const_iv_clone (SETTLS)
136	root	1.1	# endif
137			# ifdef CLONE_PARENT_SETTID
138	root	1.4	const_iv_clone (PARENT_SETTID)
139	root	1.1	# endif
140			# ifdef CLONE_CHILD_CLEARTID
141	root	1.4	const_iv_clone (CHILD_CLEARTID)
142	root	1.1	# endif
143			# ifdef CLONE_DETACHED
144	root	1.4	const_iv_clone (DETACHED)
145	root	1.1	# endif
146			# ifdef CLONE_UNTRACED
147	root	1.4	const_iv_clone (UNTRACED)
148	root	1.1	# endif
149			# ifdef CLONE_CHILD_SETTID
150	root	1.4	const_iv_clone (CHILD_SETTID)
151	root	1.1	# endif
152			# ifdef CLONE_NEWUSER
153	root	1.4	const_iv_clone (NEWUSER)
154	root	1.1	# endif
155			# ifdef CLONE_NEWPID
156	root	1.4	const_iv_clone (NEWPID)
157	root	1.1	# endif
158			# ifdef CLONE_IO
159	root	1.4	const_iv_clone (IO)
160	root	1.1	# endif
161	root	1.2	# ifdef CLONE_NEWCGROUP
162	root	1.4	const_iv_clone (NEWCGROUP)
163	root	1.3	# endif
164	root	1.5	# ifdef CLONE_PIDFD
165			const_iv_clone (PIDFD)
166			# endif
167	root	1.3	# ifdef SYS_kcmp
168			const_iv (KCMP_FILE)
169			const_iv (KCMP_VM)
170			const_iv (KCMP_FILES)
171			const_iv (KCMP_FS)
172			const_iv (KCMP_SIGHAND)
173			const_iv (KCMP_IO)
174			const_iv (KCMP_SYSVSEM)
175	root	1.8	const_iv (KCMP_EPOLL_TFD)
176	root	1.2	# endif
177	root	1.7	# ifdef NS_GET_USERNS
178			const_iv (NS_GET_USERNS)
179			# endif
180			# ifdef NS_GET_PARENT
181			const_iv (NS_GET_PARENT)
182			# endif
183			# ifdef NS_GET_NSTYPE
184			const_iv (NS_GET_NSTYPE)
185			# endif
186			# ifdef NS_OWNER_UID
187			const_iv (NS_OWNER_UID
188			# endif
189	root	1.1	};
190
191			for (civ = const_iv + sizeof (const_iv) / sizeof (const_iv [0]); civ > const_iv; civ--)
192			newCONSTSUB (stash, (char *)civ[-1].name, newSViv (civ[-1].iv));
193
194			int
195			clone (SV sub, IV stacksize, int flags, SV ptid = 0, SV *tls = &PL_sv_undef)
196			CODE:
197			{
198	root	1.2	if (!stacksize)
199	root	1.1	stacksize = 4 << 20;
200
201			pid_t ptid_;
202			char *stack_ptr = mmap (0, stacksize, PROT_EXEC \| PROT_READ \| PROT_WRITE, MAP_PRIVATE \| MAP_ANONYMOUS \| MAP_GROWSDOWN \| MAP_STACK, -1, 0);
203
204			#ifndef __hppa
205			stack_ptr += stacksize - 16; /* be safe and put the sp at 16 bytes below the end */
206			#endif
207
208			RETVAL = -1;
209			if (stack_ptr != (void *)-1)
210			{
211			SV *my_sub = newSVsv (sub);
212
213			RETVAL = clone (clone_cb, (void )stack_ptr, flags, (void )my_sub, &ptid, SvOK (tls) ? SvPV_nolen (tls) : 0, 0);
214
215			if (ptid) sv_setiv (ptid, (IV)ptid_);
216
217			if ((flags & (CLONE_VM \| CLONE_VFORK)) != CLONE_VM)
218			{
219			int old_errno = errno;
220			munmap (stack_ptr, stacksize);
221			errno = old_errno;
222			}
223			}
224			}
225	root	1.6	OUTPUT: RETVAL
226	root	1.1
227	root	1.2	int
228			unshare (int flags)
229	root	1.9	PROTOTYPE: @
230	root	1.2
231			int
232			setns (SV *fh_or_fd, int nstype = 0)
233			C_ARGS: s_fileno (fh_or_fd, 0), nstype
234	root	1.3
235			int
236			pivot_root (SV new_root, SV old_root)
237			CODE:
238			RETVAL = syscall (SYS_pivot_root,
239			(const char *)SvPVbyte_nolen (new_root),
240			(const char *)SvPVbyte_nolen (old_root));
241	root	1.6	OUTPUT: RETVAL
242	root	1.3
243			int
244			kcmp (IV pid1, IV pid2, IV type, UV idx1 = 0, UV idx2 = 0)
245
246	root	1.6	int
247			siocsifflags (char *ifname, U32 flags = IFF_UP)
248			CODE:
249			{
250			int saved_errno;
251			struct ifreq ifr;
252			int fd = socket (AF_INET, SOCK_DGRAM, 0);
253			strncpy (ifr.ifr_name, ifname, sizeof (ifr.ifr_name));
254			RETVAL = ioctl (fd, SIOCSIFFLAGS, &ifr);
255			saved_errno = errno;
256			close (fd);
257			errno = saved_errno;
258			}
259			OUTPUT: RETVAL
260