X-Git-Url: http://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust-fork%2Fustfork.c;h=32fae490bb6bf1739fdc64198cf44f42bff43a44;hb=c0c0989ab70574e09b2f7e8b48c2da6af664a849;hp=5e6acba16e87fb9893ee7c9fe3b756afae12dd38;hpb=69400ac4a4e6575f749c6326df7c2a2c8ac3bdc5;p=lttng-ust.git diff --git a/liblttng-ust-fork/ustfork.c b/liblttng-ust-fork/ustfork.c index 5e6acba1..32fae490 100644 --- a/liblttng-ust-fork/ustfork.c +++ b/liblttng-ust-fork/ustfork.c @@ -1,65 +1,239 @@ /* - * Copyright (C) 2009 Pierre-Marc Fournier - * Copyright (C) 2011 Mathieu Desnoyers - * - * This library is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; version 2.1 of - * the License. - * - * This library is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. + * SPDX-License-Identifier: LGPL-2.1-only * - * You should have received a copy of the GNU Lesser General Public - * License along with this library; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + * Copyright (C) 2009 Pierre-Marc Fournier + * Copyright (C) 2011-2012 Mathieu Desnoyers */ -#define _GNU_SOURCE -#include +#include #include #include #include #include #include -#include "usterr.h" +#include #include -struct user_desc; - pid_t fork(void) { static pid_t (*plibc_func)(void) = NULL; - ust_fork_info_t fork_info; + sigset_t sigset; pid_t retval; + int saved_errno; if (plibc_func == NULL) { plibc_func = dlsym(RTLD_NEXT, "fork"); if (plibc_func == NULL) { fprintf(stderr, "libustfork: unable to find \"fork\" symbol\n"); + errno = ENOSYS; return -1; } } - ust_before_fork(&fork_info); + ust_before_fork(&sigset); /* Do the real fork */ retval = plibc_func(); + saved_errno = errno; if (retval == 0) { /* child */ - ust_after_fork_child(&fork_info); + 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; + sigset_t sigset; + int retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "daemon"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"daemon\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + ust_before_fork(&sigset); + /* Do the real daemon call */ + retval = plibc_func(nochdir, noclose); + saved_errno = errno; + if (retval == 0) { + /* child, parent called _exit() directly */ + ust_after_fork_child(&sigset); } else { - ust_after_fork_parent(&fork_info); + /* 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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setuid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setuid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setuid */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setgid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setgid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setgid */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "seteuid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"seteuid\" symbol\n"); + errno = ENOSYS; + return -1; + } } + + /* Do the real seteuid */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setegid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setegid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setegid */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setreuid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setreuid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setreuid */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setregid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setregid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setregid */ + retval = plibc_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; - ust_fork_info_t fork_info; + sigset_t sigset; }; static int clone_fn(void *arg) @@ -67,7 +241,7 @@ static int clone_fn(void *arg) struct ustfork_clone_info *info = (struct ustfork_clone_info *) arg; /* clone is now done and we are in child */ - ust_after_fork_child(&info->fork_info); + ust_after_fork_child(&info->sigset); return info->fn(info->arg); } @@ -83,6 +257,7 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...) /* end of var args */ va_list ap; int retval; + int saved_errno; va_start(ap, arg); ptid = va_arg(ap, pid_t *); @@ -94,6 +269,7 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...) plibc_func = dlsym(RTLD_NEXT, "clone"); if (plibc_func == NULL) { fprintf(stderr, "libustfork: unable to find \"clone\" symbol.\n"); + errno = ENOSYS; return -1; } } @@ -105,15 +281,160 @@ int clone(int (*fn)(void *), void *child_stack, int flags, void *arg, ...) */ retval = plibc_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.fork_info); + ust_before_fork(&info.sigset); retval = plibc_func(clone_fn, child_stack, flags, &info, ptid, tls, ctid); + saved_errno = errno; /* The child doesn't get here. */ - ust_after_fork_parent(&info.fork_info); + 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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setns"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setns\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setns */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "unshare"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"unshare\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setns */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setresuid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setresuid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setresuid */ + retval = plibc_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 retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "setresgid"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"setresgid\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + /* Do the real setresgid */ + retval = plibc_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)(void) = NULL; + sigset_t sigset; + pid_t retval; + int saved_errno; + + if (plibc_func == NULL) { + plibc_func = dlsym(RTLD_NEXT, "rfork"); + if (plibc_func == NULL) { + fprintf(stderr, "libustfork: unable to find \"rfork\" symbol\n"); + errno = ENOSYS; + return -1; + } + } + + ust_before_fork(&sigset); + /* Do the real rfork */ + retval = plibc_func(); + 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