X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Frunas.c;h=d75eb21027ce0ae2b7df768698d8c913bb4297ea;hp=60e02a2bf85a4e22ff363d2a6ede3cfc1a0fd277;hb=3fd15a7429ca3f5307a783e264155ae0218511ec;hpb=4c462e790c62ed5f6c5d61b3a182762fe02f7e9a diff --git a/src/common/runas.c b/src/common/runas.c index 60e02a2bf..d75eb2102 100644 --- a/src/common/runas.c +++ b/src/common/runas.c @@ -2,18 +2,18 @@ * Copyright (C) 2011 - David Goulet * Mathieu Desnoyers * - * This program is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License as published by the Free - * Software Foundation; only version 2 of the License. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2 only, + * as published by the Free Software Foundation. * * This program 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 General Public License for + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for * more details. * - * You should have received a copy of the GNU General Public License along with - * this program; if not, write to the Free Software Foundation, Inc., 59 Temple - * Place - Suite 330, Boston, MA 02111-1307, USA. + * You should have received a copy of the GNU General Public License along + * with this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #define _GNU_SOURCE @@ -28,9 +28,12 @@ #include #include #include -#include +#include #include +#include +#include +#include #include "runas.h" @@ -40,6 +43,21 @@ #define MAP_STACK 0 #endif +#ifdef __FreeBSD__ +/* FreeBSD MAP_STACK always return -ENOMEM */ +#define LTTNG_MAP_STACK 0 +#else +#define LTTNG_MAP_STACK MAP_STACK +#endif + +#ifndef MAP_GROWSDOWN +#define MAP_GROWSDOWN 0 +#endif + +#ifndef MAP_ANONYMOUS +#define MAP_ANONYMOUS MAP_ANON +#endif + struct run_as_data { int (*cmd)(void *data); void *data; @@ -67,56 +85,12 @@ int _mkdir_recursive(void *_data) { struct run_as_mkdir_data *data = _data; const char *path; - char *p, tmp[PATH_MAX]; - struct stat statbuf; mode_t mode; - size_t len; - int ret; path = data->path; mode = data->mode; - ret = snprintf(tmp, sizeof(tmp), "%s", path); - if (ret < 0) { - PERROR("snprintf mkdir"); - goto error; - } - - len = ret; - if (tmp[len - 1] == '/') { - tmp[len - 1] = 0; - } - - for (p = tmp + 1; *p; p++) { - if (*p == '/') { - *p = 0; - ret = stat(tmp, &statbuf); - if (ret < 0) { - ret = mkdir(tmp, mode); - if (ret < 0) { - if (!(errno == EEXIST)) { - PERROR("mkdir recursive"); - ret = -errno; - goto error; - } - } - } - *p = '/'; - } - } - - ret = mkdir(tmp, mode); - if (ret < 0) { - if (!(errno == EEXIST)) { - PERROR("mkdir recursive last piece"); - ret = -errno; - } else { - ret = 0; - } - } - -error: - return ret; + return utils_mkdir_recursive(path, mode); } static @@ -136,13 +110,14 @@ int _open(void *_data) static int child_run_as(void *_data) { + int ret; struct run_as_data *data = _data; - size_t writelen, writeleft, index; + ssize_t writelen; + size_t writeleft, index; union { int i; char c[sizeof(int)]; } sendret; - int ret; /* * Child: it is safe to drop egid and euid while sharing the @@ -174,8 +149,10 @@ int child_run_as(void *_data) writeleft = sizeof(sendret); index = 0; do { - writelen = write(data->retval_pipe, &sendret.c[index], - writeleft); + do { + writelen = write(data->retval_pipe, &sendret.c[index], + writeleft); + } while (writelen < 0 && errno == EINTR); if (writelen < 0) { PERROR("write"); return EXIT_FAILURE; @@ -187,7 +164,7 @@ int child_run_as(void *_data) } static -int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) +int run_as_clone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) { struct run_as_data run_as_data; int ret = 0; @@ -225,7 +202,7 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) run_as_data.retval_pipe = retval_pipe[1]; /* write end */ child_stack = mmap(NULL, RUNAS_CHILD_STACK_SIZE, PROT_WRITE | PROT_READ, - MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | MAP_STACK, + MAP_PRIVATE | MAP_GROWSDOWN | MAP_ANONYMOUS | LTTNG_MAP_STACK, -1, 0); if (child_stack == MAP_FAILED) { PERROR("mmap"); @@ -236,9 +213,8 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) * Pointing to the middle of the stack to support architectures * where the stack grows up (HPPA). */ - pid = clone(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2), - CLONE_FILES | SIGCHLD, - &run_as_data, NULL); + pid = lttng_clone_files(child_run_as, child_stack + (RUNAS_CHILD_STACK_SIZE / 2), + &run_as_data); if (pid < 0) { PERROR("clone"); retval.i = pid; @@ -286,6 +262,42 @@ end: return retval.i; } +/* + * To be used on setups where gdb has issues debugging programs using + * clone/rfork. Note that this is for debuging ONLY, and should not be + * considered secure. + */ +static +int run_as_noclone(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) +{ + int ret; + mode_t old_mask; + + old_mask = umask(0); + ret = cmd(data); + umask(old_mask); + + return ret; +} + +static +int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) +{ + if (!getenv("LTTNG_DEBUG_NOCLONE")) { + int ret; + + DBG("Using run_as_clone"); + pthread_mutex_lock(<tng_libc_state_lock); + ret = run_as_clone(cmd, data, uid, gid); + pthread_mutex_unlock(<tng_libc_state_lock); + return ret; + } else { + DBG("Using run_as_noclone"); + return run_as_noclone(cmd, data, uid, gid); + } +} + +__attribute__((visibility("hidden"))) int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid) { struct run_as_mkdir_data data; @@ -297,6 +309,7 @@ int run_as_mkdir_recursive(const char *path, mode_t mode, uid_t uid, gid_t gid) return run_as(_mkdir_recursive, &data, uid, gid); } +__attribute__((visibility("hidden"))) int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid) { struct run_as_mkdir_data data; @@ -312,6 +325,7 @@ int run_as_mkdir(const char *path, mode_t mode, uid_t uid, gid_t gid) * Note: open_run_as is currently not working. We'd need to pass the fd * opened in the child to the parent. */ +__attribute__((visibility("hidden"))) int run_as_open(const char *path, int flags, mode_t mode, uid_t uid, gid_t gid) { struct run_as_open_data data;