X-Git-Url: https://git.lttng.org/?p=lttng-tools.git;a=blobdiff_plain;f=src%2Fcommon%2Frunas.c;h=5bd43e65b7c072b5ea40e1f6e16807f594986fe4;hp=bee107951d8664e6f111ed5ff260574407f0c3a3;hb=5b73926fb372c1b1f6d426b566bfb682f4a058b0;hpb=730389d9ab1a479e172ff3aaa0adf12580bb344c diff --git a/src/common/runas.c b/src/common/runas.c index bee107951..5bd43e65b 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 @@ -42,6 +42,21 @@ #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; @@ -138,13 +153,14 @@ 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 @@ -156,14 +172,14 @@ int child_run_as(void *_data) if (data->gid != getegid()) { ret = setegid(data->gid); if (ret < 0) { - perror("setegid"); + PERROR("setegid"); return EXIT_FAILURE; } } if (data->uid != geteuid()) { ret = seteuid(data->uid); if (ret < 0) { - perror("seteuid"); + PERROR("seteuid"); return EXIT_FAILURE; } } @@ -176,10 +192,12 @@ 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"); + PERROR("write"); return EXIT_FAILURE; } writeleft -= writelen; @@ -189,7 +207,7 @@ 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; @@ -216,7 +234,8 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) ret = pipe(retval_pipe); if (ret < 0) { - perror("pipe"); + PERROR("pipe"); + retval.i = ret; goto end; } run_as_data.data = data; @@ -226,23 +245,22 @@ 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"); - ret = -ENOMEM; + PERROR("mmap"); + retval.i = -ENOMEM; goto close_pipe; } /* * 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"); - ret = pid; + PERROR("clone"); + retval.i = pid; goto unmap_stack; } /* receive return value */ @@ -251,7 +269,7 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) do { readlen = read(retval_pipe[0], &retval.c[index], readleft); if (readlen < 0) { - perror("read"); + PERROR("read"); ret = -1; break; } @@ -265,21 +283,64 @@ int run_as(int (*cmd)(void *data), void *data, uid_t uid, gid_t gid) */ pid = waitpid(pid, &status, 0); if (pid < 0 || !WIFEXITED(status) || WEXITSTATUS(status) != 0) { - perror("wait"); - ret = -1; + PERROR("wait"); + retval.i = -1; } unmap_stack: ret = munmap(child_stack, RUNAS_CHILD_STACK_SIZE); if (ret < 0) { - perror("munmap"); + PERROR("munmap"); + retval.i = ret; } close_pipe: - close(retval_pipe[0]); - close(retval_pipe[1]); + ret = close(retval_pipe[0]); + if (ret) { + PERROR("close"); + } + ret = close(retval_pipe[1]); + if (ret) { + PERROR("close"); + } 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; @@ -291,6 +352,7 @@ 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; @@ -306,6 +368,7 @@ 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;