/*
* Copyright (C) 2009 Pierre-Marc Fournier
- * Copyright (C) 2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
*/
#define _GNU_SOURCE
-#include <dlfcn.h>
+#include <lttng/ust-dlfcn.h>
#include <unistd.h>
#include <stdio.h>
#include <signal.h>
#include <sched.h>
#include <stdarg.h>
-#include "usterr.h"
+#include <stdlib.h>
+#include <errno.h>
#include <lttng/ust.h>
-struct user_desc;
+#include <urcu/uatomic.h>
pid_t fork(void)
{
static pid_t (*plibc_func)(void) = NULL;
+ pid_t (*func)(void);
sigset_t sigset;
pid_t retval;
+ int saved_errno;
- if (plibc_func == NULL) {
- plibc_func = dlsym(RTLD_NEXT, "fork");
- if (plibc_func == NULL) {
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "fork");
+ if (func == NULL) {
fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n");
+ errno = ENOSYS;
return -1;
}
+ uatomic_set(&plibc_func, func);
}
ust_before_fork(&sigset);
/* Do the real fork */
- retval = plibc_func();
+ retval = func();
+ saved_errno = errno;
if (retval == 0) {
/* child */
ust_after_fork_child(&sigset);
} else {
ust_after_fork_parent(&sigset);
}
+ errno = saved_errno;
+ return retval;
+}
+
+int daemon(int nochdir, int noclose)
+{
+ static int (*plibc_func)(int nochdir, int noclose) = NULL;
+ int (*func)(int nochdir, int noclose);
+ sigset_t sigset;
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "daemon");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"daemon\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ ust_before_fork(&sigset);
+ /* Do the real daemon call */
+ retval = func(nochdir, noclose);
+ saved_errno = errno;
+ if (retval == 0) {
+ /* child, parent called _exit() directly */
+ ust_after_fork_child(&sigset);
+ } else {
+ /* on error in the parent */
+ ust_after_fork_parent(&sigset);
+ }
+ errno = saved_errno;
+ return retval;
+}
+
+int setuid(uid_t uid)
+{
+ static int (*plibc_func)(uid_t uid) = NULL;
+ int (*func)(uid_t uid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setuid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setuid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setuid */
+ retval = func(uid);
+ saved_errno = errno;
+
+ ust_after_setuid();
+
+ errno = saved_errno;
+ return retval;
+}
+
+int setgid(gid_t gid)
+{
+ static int (*plibc_func)(gid_t gid) = NULL;
+ int (*func)(gid_t gid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setgid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setgid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setgid */
+ retval = func(gid);
+ saved_errno = errno;
+
+ ust_after_setgid();
+
+ errno = saved_errno;
return retval;
}
+int seteuid(uid_t euid)
+{
+ static int (*plibc_func)(uid_t euid) = NULL;
+ int (*func)(uid_t euid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "seteuid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"seteuid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real seteuid */
+ retval = func(euid);
+ saved_errno = errno;
+
+ ust_after_seteuid();
+
+ errno = saved_errno;
+ return retval;
+}
+
+int setegid(gid_t egid)
+{
+ static int (*plibc_func)(gid_t egid) = NULL;
+ int (*func)(gid_t egid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setegid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setegid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setegid */
+ retval = func(egid);
+ saved_errno = errno;
+
+ ust_after_setegid();
+
+ errno = saved_errno;
+ return retval;
+}
+
+int setreuid(uid_t ruid, uid_t euid)
+{
+ static int (*plibc_func)(uid_t ruid, uid_t euid) = NULL;
+ int (*func)(uid_t ruid, uid_t euid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setreuid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setreuid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setreuid */
+ retval = func(ruid, euid);
+ saved_errno = errno;
+
+ ust_after_setreuid();
+
+ errno = saved_errno;
+ return retval;
+}
+
+int setregid(gid_t rgid, gid_t egid)
+{
+ static int (*plibc_func)(gid_t rgid, gid_t egid) = NULL;
+ int (*func)(gid_t rgid, gid_t egid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setregid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setregid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setregid */
+ retval = func(rgid, egid);
+ saved_errno = errno;
+
+ ust_after_setregid();
+
+ errno = saved_errno;
+ return retval;
+}
+
+#ifdef __linux__
+
+struct user_desc;
+
struct ustfork_clone_info {
int (*fn)(void *);
void *arg;
static int (*plibc_func)(int (*fn)(void *), void *child_stack,
int flags, void *arg, pid_t *ptid,
struct user_desc *tls, pid_t *ctid) = NULL;
+ int (*func)(int (*fn)(void *), void *child_stack,
+ int flags, void *arg, pid_t *ptid,
+ struct user_desc *tls, pid_t *ctid);
/* var args */
pid_t *ptid;
struct user_desc *tls;
/* end of var args */
va_list ap;
int retval;
+ int saved_errno;
va_start(ap, arg);
ptid = va_arg(ap, pid_t *);
ctid = va_arg(ap, pid_t *);
va_end(ap);
- if (plibc_func == NULL) {
- plibc_func = dlsym(RTLD_NEXT, "clone");
- if (plibc_func == NULL) {
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "clone");
+ if (func == NULL) {
fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n");
+ errno = ENOSYS;
return -1;
}
+ uatomic_set(&plibc_func, func);
}
if (flags & CLONE_VM) {
* Creating a thread, no need to intervene, just pass on
* the arguments.
*/
- retval = plibc_func(fn, child_stack, flags, arg, ptid,
- tls, ctid);
+ retval = func(fn, child_stack, flags, arg, ptid,
+ tls, ctid);
+ saved_errno = errno;
} else {
/* Creating a real process, we need to intervene. */
- struct ustfork_clone_info info = { fn: fn, arg: arg };
+ struct ustfork_clone_info info = { .fn = fn, .arg = arg };
ust_before_fork(&info.sigset);
- retval = plibc_func(clone_fn, child_stack, flags, &info,
- ptid, tls, ctid);
+ retval = func(clone_fn, child_stack, flags, &info,
+ ptid, tls, ctid);
+ saved_errno = errno;
/* The child doesn't get here. */
ust_after_fork_parent(&info.sigset);
}
+ errno = saved_errno;
+ return retval;
+}
+
+int setns(int fd, int nstype)
+{
+ static int (*plibc_func)(int fd, int nstype) = NULL;
+ int (*func)(int fd, int nstype);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setns");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setns\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setns */
+ retval = func(fd, nstype);
+ saved_errno = errno;
+
+ ust_after_setns();
+
+ errno = saved_errno;
+ return retval;
+}
+
+int unshare(int flags)
+{
+ static int (*plibc_func)(int flags) = NULL;
+ int (*func)(int flags);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "unshare");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"unshare\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setns */
+ retval = func(flags);
+ saved_errno = errno;
+
+ ust_after_unshare();
+
+ errno = saved_errno;
+ return retval;
+}
+
+int setresuid(uid_t ruid, uid_t euid, uid_t suid)
+{
+ static int (*plibc_func)(uid_t ruid, uid_t euid, uid_t suid) = NULL;
+ int (*func)(uid_t ruid, uid_t euid, uid_t suid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setresuid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setresuid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setresuid */
+ retval = func(ruid, euid, suid);
+ saved_errno = errno;
+
+ ust_after_setresuid();
+
+ errno = saved_errno;
return retval;
}
+
+int setresgid(gid_t rgid, gid_t egid, gid_t sgid)
+{
+ static int (*plibc_func)(gid_t rgid, gid_t egid, gid_t sgid) = NULL;
+ int (*func)(gid_t rgid, gid_t egid, gid_t sgid);
+ int retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "setresgid");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"setresgid\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ /* Do the real setresgid */
+ retval = func(rgid, egid, sgid);
+ saved_errno = errno;
+
+ ust_after_setresgid();
+
+ errno = saved_errno;
+ return retval;
+}
+
+#elif defined (__FreeBSD__)
+
+pid_t rfork(int flags)
+{
+ static pid_t (*plibc_func)(int flags) = NULL;
+ pid_t (*func)(int flags);
+ sigset_t sigset;
+ pid_t retval;
+ int saved_errno;
+
+ func = uatomic_read(&plibc_func);
+ if (func == NULL) {
+ func = dlsym(RTLD_NEXT, "rfork");
+ if (func == NULL) {
+ fprintf(stderr, "libustfork: unable to find \"rfork\" symbol\n");
+ errno = ENOSYS;
+ return -1;
+ }
+ uatomic_set(&plibc_func, func);
+ }
+
+ ust_before_fork(&sigset);
+ /* Do the real rfork */
+ retval = func(flags);
+ saved_errno = errno;
+ if (retval == 0) {
+ /* child */
+ ust_after_fork_child(&sigset);
+ } else {
+ ust_after_fork_parent(&sigset);
+ }
+ errno = saved_errno;
+ return retval;
+}
+
+/*
+ * On BSD, no need to override vfork, because it runs in the context of
+ * the parent, with parent waiting until execve or exit is executed in
+ * the child.
+ */
+
+#else
+#warning "Unknown OS. You might want to ensure that fork/clone/vfork/fork handling is complete."
+#endif