[OpenWrt-Devel] [PATCH procd 2/2] ujail: rework file dependencies detection (use ldd)
John Crispin
john at phrozen.org
Sat Nov 21 03:06:01 EST 2015
Hi,
can you please convert this to c code ? we dont like c++ patterns
John
On 21/11/2015 00:05, Etienne CHAMPETIER wrote:
> Using ldd (via popen()) is a hack, but it's simpler (and working)
> we have 3 libc and many archs, too many ways to resolve .so
>
> Current code:
> -do not parse the intepreter (PT_INTERP) part of the elf
> -do not get the library path priority right (/lib64 is before /lib,
> musl take the libs in /lib even on 64bits images)
> -do not handle RPATH
>
> This patch:
> -use ldd to detect ELF dependencies
> -add support for shell script
>
> uClibc ldd doesn't work with shared lib, thus this patch break
> seccomp with uClibc
>
> Signed-off-by: Etienne CHAMPETIER <champetier.etienne at gmail.com>
> ---
> CMakeLists.txt | 2 +-
> jail/deps.c | 198 ++++++++++++++++++++++++++++++++
> jail/deps.h | 23 ++++
> jail/elf.c | 355 ---------------------------------------------------------
> jail/elf.h | 38 ------
> jail/jail.c | 138 +++++++---------------
> jail/jail.h | 18 +++
> 7 files changed, 284 insertions(+), 488 deletions(-)
> create mode 100644 jail/deps.c
> create mode 100644 jail/deps.h
> delete mode 100644 jail/elf.c
> delete mode 100644 jail/elf.h
> create mode 100644 jail/jail.h
>
> diff --git a/CMakeLists.txt b/CMakeLists.txt
> index d749c25..8e3f7ea 100644
> --- a/CMakeLists.txt
> +++ b/CMakeLists.txt
> @@ -87,7 +87,7 @@ ADD_DEPENDENCIES(preload-seccomp syscall-names-h)
> endif()
>
> IF(JAIL_SUPPORT)
> -ADD_EXECUTABLE(ujail jail/jail.c jail/elf.c jail/capabilities.c)
> +ADD_EXECUTABLE(ujail jail/jail.c jail/deps.c jail/capabilities.c)
> TARGET_LINK_LIBRARIES(ujail ubox blobmsg_json)
> INSTALL(TARGETS ujail
> RUNTIME DESTINATION ${CMAKE_INSTALL_SBINDIR}
> diff --git a/jail/deps.c b/jail/deps.c
> new file mode 100644
> index 0000000..0141cef
> --- /dev/null
> +++ b/jail/deps.c
> @@ -0,0 +1,198 @@
> +/*
> + * Copyright (C) 2015 John Crispin <blogic at openwrt.org>
> + * Copyright (C) 2015 Etienne Champetier <champetier.etienne at gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU Lesser General Public License version 2.1
> + * 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 more details.
> + */
> +
> +#define _GNU_SOURCE
> +
> +#include <assert.h>
> +#include <elf.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <libgen.h>
> +#include <linux/limits.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/mount.h>
> +#include <sys/stat.h>
> +#include <sys/types.h>
> +#include <unistd.h>
> +
> +#include <libubox/avl.h>
> +#include <libubox/avl-cmp.h>
> +
> +#include "deps.h"
> +#include "log.h"
> +#include "jail.h"
> +
> +struct mount {
> + struct avl_node avl;
> + const char *path;
> + int readonly;
> + int error;
> +};
> +
> +struct avl_tree mounts;
> +
> +static int add_mount(const char *path, int readonly, int error)
> +{
> + if (avl_find(&mounts, path))
> + return 1;
> +
> + struct mount *m;
> + m = calloc(1, sizeof(struct mount));
> + assert(m != NULL);
> + m->avl.key = m->path = strdup(path);
> + m->readonly = readonly;
> + m->error = error;
> +
> + avl_insert(&mounts, &m->avl);
> + DEBUG("adding mount %s ro(%d) err(%d)\n", m->path, m->readonly, m->error != 0);
> + return 0;
> +}
> +
> +int add_mount_if_exists(const char *path, int readonly, int error) {
> + struct stat s;
> + if (stat(path, &s) == -1) {
> + DEBUG("%s doesn't exist\n", path);
> + return -1;
> + }
> + return add_mount(path, readonly, error);
> +}
> +
> +int mount_all(const char *jailroot) {
> + struct mount *m;
> + avl_for_each_element(&mounts, m, avl)
> + if (mount_bind(jailroot, m->path, m->readonly, m->error))
> + return -1;
> +
> + return 0;
> +}
> +
> +void mount_list_init() {
> + avl_init(&mounts, avl_strcmp, false, NULL);
> +}
> +
> +//we already read 2 char from f (#!)
> +static int add_script_deps(FILE *f, const char *path, int readonly, int error)
> +{
> + char buf[PATH_MAX];
> + int i = 0;
> + int c;
> + while ((c = fgetc(f)) != EOF) {
> + if (i == 0 && c != '/')
> + continue;
> + if (c <= 0x20 || c > 0x7e)
> + break;
> + buf[i] = c;
> + i++;
> + if (i >= sizeof(buf)) {
> + ERROR("script interpretor too long (%s)\n", path);
> + return -1;
> + }
> + }
> + buf[i] = '\0';
> + return add_path_and_deps(buf, readonly, error);
> +}
> +
> +static int add_elf_deps(const char *path, int readonly, int error)
> +{
> + char buf[PATH_MAX];
> + int nb = snprintf(buf, sizeof(buf), "ldd %s", path);
> + assert(nb >= 0);
> +
> + FILE *f = popen(buf, "r");
> + char c;
> + int i = 0;
> + while (((c = fgetc(f)) != EOF)) {
> + if (i == 0 && c != '/') {
> + continue;
> + } else if (i > 0 && (c <= ' ' || c > '~')) {
> + buf[i] = '\0';
> + add_mount(buf, readonly, error);
> + i = 0;
> + } else if (i > 0 || c == '/') {
> + buf[i] = c;
> + i++;
> + }
> +
> + if (i >= sizeof(buf)) {
> + ERROR("shared lib too long (%s)\n", path);
> + return -1;
> + }
> + }
> + pclose(f);
> + return 0;
> +}
> +
> +int add_path_and_deps(const char *path, int readonly, int error)
> +{
> + assert(path != NULL);
> +
> + if (path[0] != '/') {
> + ERROR("only absolute path are supported (%s)\n", path);
> + return error;
> + }
> +
> + struct stat s;
> + if (stat(path, &s) == -1) {
> + ERROR("stat(%s) failed: %s\n", path, strerror(errno));
> + return error;
> + }
> +
> + //path already in list
> + if (add_mount(path, readonly, error) == 1)
> + return 0;
> +
> + if (!S_ISREG(s.st_mode))
> + return 0;
> +
> + //too small to be an ELF or a script
> + if (s.st_size < 4)
> + return 0;
> +
> + FILE *f;
> + if ((f = fopen(path, "r")) == NULL) {
> + ERROR("fopen(%s) failed: %s\n", path, strerror(errno));
> + return error;
> + }
> +
> + int ret = 0;
> + int c = fgetc(f);
> + switch(c) {
> + //script ?
> + case '#':
> + c = fgetc(f);
> + if (c != '!') {
> + goto out;
> + }
> + //this is a script
> + ret = add_script_deps(f, path, readonly, error);
> + goto out;
> + //elf ?
> + case ELFMAG0:
> + if ((c = fgetc(f)) != ELFMAG1
> + || (c = fgetc(f)) != ELFMAG2
> + || (c = fgetc(f)) != ELFMAG3) {
> + goto out;
> + }
> + ret = add_elf_deps(path, readonly, error);
> + goto out;
> + }
> +out:
> + if (f != NULL)
> + fclose(f);
> +
> + return ret;
> +}
> +
> diff --git a/jail/deps.h b/jail/deps.h
> new file mode 100644
> index 0000000..da2a914
> --- /dev/null
> +++ b/jail/deps.h
> @@ -0,0 +1,23 @@
> +/*
> + * Copyright (C) 2015 Etienne Champetier <champetier.etienne at gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU Lesser General Public License version 2.1
> + * 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 more details.
> + */
> +
> +#ifndef _DEPS_H__
> +
> +#include "log.h"
> +
> +int add_mount_if_exists(const char *path, int readonly, int error);
> +int add_path_and_deps(const char *path, int readonly, int error);
> +int mount_all(const char *jailroot);
> +void mount_list_init();
> +
> +#endif
> diff --git a/jail/elf.c b/jail/elf.c
> deleted file mode 100644
> index cbb3051..0000000
> --- a/jail/elf.c
> +++ /dev/null
> @@ -1,355 +0,0 @@
> -/*
> - * Copyright (C) 2015 John Crispin <blogic at openwrt.org>
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU Lesser General Public License version 2.1
> - * 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 more details.
> - */
> -
> -#define _GNU_SOURCE
> -#include <sys/mman.h>
> -
> -#include <stdlib.h>
> -#include <unistd.h>
> -#include <stdio.h>
> -#include <string.h>
> -#include <sys/stat.h>
> -#include <fcntl.h>
> -#include <libgen.h>
> -#include <glob.h>
> -#include <elf.h>
> -
> -#include <libubox/utils.h>
> -
> -#include "elf.h"
> -
> -struct avl_tree libraries;
> -static LIST_HEAD(library_paths);
> -
> -void alloc_library_path(const char *path)
> -{
> - struct library_path *p;
> - char *_path;
> -
> - p = calloc_a(sizeof(*p),
> - &_path, strlen(path) + 1);
> - if (!p)
> - return;
> -
> - p->path = strcpy(_path, path);
> -
> - list_add_tail(&p->list, &library_paths);
> - DEBUG("adding ld.so path %s\n", path);
> -}
> -
> -static void alloc_library(const char *path, const char *name)
> -{
> - struct library *l;
> - char *_name, *_path;
> -
> - l = calloc_a(sizeof(*l),
> - &_path, strlen(path) + 1,
> - &_name, strlen(name) + 1);
> - if (!l)
> - return;
> -
> - l->avl.key = l->name = strcpy(_name, name);
> - l->path = strcpy(_path, path);
> -
> - avl_insert(&libraries, &l->avl);
> - DEBUG("adding library %s/%s\n", path, name);
> -}
> -
> -static int elf_open(char **dir, char *file)
> -{
> - struct library_path *p;
> - char path[256];
> - int fd = -1;
> -
> - *dir = NULL;
> -
> - list_for_each_entry(p, &library_paths, list) {
> - if (strlen(p->path))
> - snprintf(path, sizeof(path), "%s/%s", p->path, file);
> - else
> - strncpy(path, file, sizeof(path));
> - fd = open(path, O_RDONLY);
> - if (fd >= 0) {
> - *dir = p->path;
> - break;
> - }
> - }
> -
> - if (fd == -1)
> - fd = open(file, O_RDONLY);
> -
> - return fd;
> -}
> -
> -char* find_lib(char *file)
> -{
> - struct library *l;
> - static char path[256];
> - const char *p;
> -
> - l = avl_find_element(&libraries, file, l, avl);
> - if (!l)
> - return NULL;
> -
> - p = l->path;
> - if (strstr(p, "local"))
> - p = "/lib";
> -
> - snprintf(path, sizeof(path), "%s/%s", p, file);
> -
> - return path;
> -}
> -
> -static int elf64_find_section(char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr)
> -{
> - Elf64_Ehdr *e;
> - Elf64_Phdr *ph;
> - int i;
> -
> - e = (Elf64_Ehdr *) map;
> - ph = (Elf64_Phdr *) (map + e->e_phoff);
> -
> - for (i = 0; i < e->e_phnum; i++) {
> - if (ph[i].p_type == type) {
> - *offset = ph[i].p_offset;
> - if (size)
> - *size = ph[i].p_filesz;
> - if (vaddr)
> - *vaddr = ph[i].p_vaddr;
> - return 0;
> - }
> - }
> -
> - return -1;
> -}
> -
> -static int elf32_find_section(char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr)
> -{
> - Elf32_Ehdr *e;
> - Elf32_Phdr *ph;
> - int i;
> -
> - e = (Elf32_Ehdr *) map;
> - ph = (Elf32_Phdr *) (map + e->e_phoff);
> -
> - for (i = 0; i < e->e_phnum; i++) {
> - if (ph[i].p_type == type) {
> - *offset = ph[i].p_offset;
> - if (size)
> - *size = ph[i].p_filesz;
> - if (vaddr)
> - *vaddr = ph[i].p_vaddr;
> - return 0;
> - }
> - }
> -
> - return -1;
> -}
> -
> -static int elf_find_section(char *map, unsigned int type, unsigned int *offset, unsigned int *size, unsigned int *vaddr)
> -{
> - int clazz = map[EI_CLASS];
> -
> - if (clazz == ELFCLASS32)
> - return elf32_find_section(map, type, offset, size, vaddr);
> - else if (clazz == ELFCLASS64)
> - return elf64_find_section(map, type, offset, size, vaddr);
> -
> - ERROR("unknown elf format %d\n", clazz);
> -
> - return -1;
> -}
> -
> -static int elf32_scan_dynamic(char *map, int dyn_offset, int dyn_size, int load_offset)
> -{
> - Elf32_Dyn *dynamic = (Elf32_Dyn *) (map + dyn_offset);
> - char *strtab = NULL;
> -
> - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
> - Elf32_Dyn *curr = dynamic;
> -
> - dynamic++;
> - if (curr->d_tag != DT_STRTAB)
> - continue;
> -
> - strtab = map + (curr->d_un.d_val - load_offset);
> - break;
> - }
> -
> - if (!strtab)
> - return -1;
> -
> - dynamic = (Elf32_Dyn *) (map + dyn_offset);
> - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
> - Elf32_Dyn *curr = dynamic;
> -
> - dynamic++;
> - if (curr->d_tag != DT_NEEDED)
> - continue;
> -
> - if (elf_load_deps(&strtab[curr->d_un.d_val]))
> - return -1;
> - }
> -
> - return 0;
> -}
> -
> -static int elf64_scan_dynamic(char *map, int dyn_offset, int dyn_size, int load_offset)
> -{
> - Elf64_Dyn *dynamic = (Elf64_Dyn *) (map + dyn_offset);
> - char *strtab = NULL;
> -
> - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
> - Elf64_Dyn *curr = dynamic;
> -
> - dynamic++;
> - if (curr->d_tag != DT_STRTAB)
> - continue;
> -
> - strtab = map + (curr->d_un.d_val - load_offset);
> - break;
> - }
> -
> - if (!strtab)
> - return -1;
> -
> - dynamic = (Elf64_Dyn *) (map + dyn_offset);
> - while ((void *) dynamic < (void *) (map + dyn_offset + dyn_size)) {
> - Elf64_Dyn *curr = dynamic;
> -
> - dynamic++;
> - if (curr->d_tag != DT_NEEDED)
> - continue;
> -
> - if (elf_load_deps(&strtab[curr->d_un.d_val]))
> - return -1;
> - }
> -
> - return 0;
> -}
> -
> -int elf_load_deps(char *library)
> -{
> - unsigned int dyn_offset, dyn_size;
> - unsigned int load_offset, load_vaddr;
> - struct stat s;
> - char *map = NULL, *dir = NULL;
> - int clazz, fd, ret = -1;
> -
> - if (avl_find(&libraries, library))
> - return 0;
> -
> - fd = elf_open(&dir, library);
> -
> - if (fd < 0) {
> - ERROR("failed to open %s\n", library);
> - return -1;
> - }
> -
> - if (fstat(fd, &s) == -1) {
> - ERROR("failed to stat %s\n", library);
> - ret = -1;
> - goto err_out;
> - }
> -
> - map = mmap(NULL, s.st_size, PROT_READ, MAP_PRIVATE, fd, 0);
> - if (map == MAP_FAILED) {
> - ERROR("failed to mmap %s\n", library);
> - ret = -1;
> - goto err_out;
> - }
> -
> - if (elf_find_section(map, PT_LOAD, &load_offset, NULL, &load_vaddr)) {
> - ERROR("failed to load the .load section from %s\n", library);
> - ret = -1;
> - goto err_out;
> - }
> -
> - if (elf_find_section(map, PT_DYNAMIC, &dyn_offset, &dyn_size, NULL)) {
> - ERROR("failed to load the .dynamic section from %s\n", library);
> - ret = -1;
> - goto err_out;
> - }
> -
> - if (dir) {
> - alloc_library(dir, library);
> - } else {
> - char *elf = strdup(library);
> -
> - alloc_library(dirname(elf), basename(library));
> - free(elf);
> - }
> - clazz = map[EI_CLASS];
> -
> - if (clazz == ELFCLASS32)
> - ret = elf32_scan_dynamic(map, dyn_offset, dyn_size, load_vaddr - load_offset);
> - else if (clazz == ELFCLASS64)
> - ret = elf64_scan_dynamic(map, dyn_offset, dyn_size, load_vaddr - load_offset);
> -
> -err_out:
> - if (map)
> - munmap(map, s.st_size);
> - close(fd);
> -
> - return ret;
> -}
> -
> -void load_ldso_conf(const char *conf)
> -{
> - FILE* fp = fopen(conf, "r");
> - char line[256];
> -
> - if (!fp) {
> - DEBUG("failed to open %s\n", conf);
> - return;
> - }
> -
> - while (!feof(fp)) {
> - int len;
> -
> - if (!fgets(line, 256, fp))
> - break;
> - len = strlen(line);
> - if (len < 2)
> - continue;
> - if (*line == '#')
> - continue;
> - if (line[len - 1] == '\n')
> - line[len - 1] = '\0';
> - if (!strncmp(line, "include ", 8)) {
> - char *sep = strstr(line, " ");
> - glob_t gl;
> - int i;
> -
> - if (!sep)
> - continue;;
> - while (*sep == ' ')
> - sep++;
> - if (glob(sep, GLOB_NOESCAPE | GLOB_MARK, NULL, &gl)) {
> - ERROR("glob failed on %s\n", sep);
> - continue;
> - }
> - for (i = 0; i < gl.gl_pathc; i++)
> - load_ldso_conf(gl.gl_pathv[i]);
> - globfree(&gl);
> - } else {
> - struct stat s;
> -
> - if (stat(line, &s))
> - continue;
> - alloc_library_path(line);
> - }
> - }
> -
> - fclose(fp);
> -}
> diff --git a/jail/elf.h b/jail/elf.h
> deleted file mode 100644
> index 3ae311e..0000000
> --- a/jail/elf.h
> +++ /dev/null
> @@ -1,38 +0,0 @@
> -/*
> - * Copyright (C) 2015 John Crispin <blogic at openwrt.org>
> - *
> - * This program is free software; you can redistribute it and/or modify
> - * it under the terms of the GNU Lesser General Public License version 2.1
> - * 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 more details.
> - */
> -
> -#ifndef _ELF_H__
> -#include <libubox/avl.h>
> -#include <libubox/avl-cmp.h>
> -
> -#include "log.h"
> -
> -struct library {
> - struct avl_node avl;
> - char *name;
> - char *path;
> -};
> -
> -struct library_path {
> - struct list_head list;
> - char *path;
> -};
> -
> -extern struct avl_tree libraries;
> -
> -extern void alloc_library_path(const char *path);
> -extern char* find_lib(char *file);
> -extern int elf_load_deps(char *library);
> -extern void load_ldso_conf(const char *conf);
> -
> -#endif
> diff --git a/jail/jail.c b/jail/jail.c
> index 08babde..391c196 100644
> --- a/jail/jail.c
> +++ b/jail/jail.c
> @@ -12,27 +12,28 @@
> */
>
> #define _GNU_SOURCE
> -#include <sys/mount.h>
> -#include <sys/prctl.h>
> -#include <sys/wait.h>
>
> -#include <stdlib.h>
> -#include <unistd.h>
> -#include <values.h>
> #include <errno.h>
> -#include <stdio.h>
> -#include <string.h>
> -#include <sys/stat.h>
> #include <fcntl.h>
> #include <libgen.h>
> +#include <linux/limits.h>
> #include <sched.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <sys/mount.h>
> +#include <sys/prctl.h>
> +#include <sys/stat.h>
> +#include <sys/wait.h>
> +#include <unistd.h>
>
> -#include "elf.h"
> -#include "capabilities.h"
> -
> -#include <libubox/list.h>
> #include <libubox/uloop.h>
>
> +#include "capabilities.h"
> +#include "deps.h"
> +#include "jail.h"
> +#include "log.h"
> +
> #define STACK_SIZE (1024 * 1024)
> #define OPT_ARGS "P:S:C:n:r:w:d:psulo"
>
> @@ -48,16 +49,6 @@ static struct {
> int sysfs;
> } opts;
>
> -struct extra {
> - struct list_head list;
> -
> - const char *path;
> - const char *name;
> - int readonly;
> -};
> -
> -static LIST_HEAD(extras);
> -
> extern int pivot_root(const char *new_root, const char *put_old);
>
> int debug = 0;
> @@ -89,42 +80,34 @@ static int mkdir_p(char *dir, mode_t mask)
> return ret;
> }
>
> -static int mount_bind(const char *root, const char *path, const char *name, int readonly, int error)
> +int mount_bind(const char *root, const char *path, int readonly, int error)
> {
> - const char *p = path;
> struct stat s;
> - char old[256];
> - char new[256];
> + char new[PATH_MAX];
> int fd;
>
> - if (strstr(p, "local"))
> - p = "/lib";
> -
> - snprintf(old, sizeof(old), "%s/%s", path, name);
> - snprintf(new, sizeof(new), "%s%s", root, p);
> -
> - mkdir_p(new, 0755);
> -
> - snprintf(new, sizeof(new), "%s%s/%s", root, p, name);
> -
> - if (stat(old, &s)) {
> - ERROR("%s does not exist\n", old);
> + if (stat(path, &s)) {
> + ERROR("stat(%s) failed: %s\n", path, strerror(errno));
> return error;
> }
>
> + snprintf(new, sizeof(new), "%s%s", root, path);
> if (S_ISDIR(s.st_mode)) {
> mkdir_p(new, 0755);
> } else {
> + mkdir_p(dirname(new), 0755);
> +
> + snprintf(new, sizeof(new), "%s%s", root, path);
> fd = creat(new, 0644);
> if (fd == -1) {
> - ERROR("failed to create %s: %s\n", new, strerror(errno));
> + ERROR("creat(%s) failed: %s\n", new, strerror(errno));
> return -1;
> }
> close(fd);
> }
>
> - if (mount(old, new, NULL, MS_BIND, NULL)) {
> - ERROR("failed to mount -B %s %s: %s\n", old, new, strerror(errno));
> + if (mount(path, new, NULL, MS_BIND, NULL)) {
> + ERROR("failed to mount -B %s %s: %s\n", path, new, strerror(errno));
> return -1;
> }
>
> @@ -133,16 +116,14 @@ static int mount_bind(const char *root, const char *path, const char *name, int
> return -1;
> }
>
> - DEBUG("mount -B %s %s\n", old, new);
> + DEBUG("mount -B %s %s\n", path, new);
>
> return 0;
> }
>
> +#define PRELOAD_SECCOMP "/lib/libpreload-seccomp.so"
> static int build_jail_fs()
> {
> - struct library *l;
> - struct extra *m;
> -
> if (mount("tmpfs", opts.path, "tmpfs", MS_NOATIME, "mode=0755")) {
> ERROR("tmpfs mount failed %s\n", strerror(errno));
> return -1;
> @@ -153,29 +134,20 @@ static int build_jail_fs()
> return -1;
> }
>
> - avl_init(&libraries, avl_strcmp, false, NULL);
> - alloc_library_path("/lib64");
> - alloc_library_path("/lib");
> - alloc_library_path("/usr/lib");
> - load_ldso_conf("/etc/ld.so.conf");
> + add_mount_if_exists("/etc/ld.so.conf", 1, -1);
>
> - if (elf_load_deps(*opts.jail_argv)) {
> + if (add_path_and_deps(*opts.jail_argv, 1, -1)) {
> ERROR("failed to load dependencies\n");
> return -1;
> }
>
> - if (opts.seccomp && elf_load_deps("libpreload-seccomp.so")) {
> + if (opts.seccomp && add_path_and_deps(PRELOAD_SECCOMP, 1, -1) == -1) {
> ERROR("failed to load libpreload-seccomp.so\n");
> return -1;
> }
>
> - avl_for_each_element(&libraries, l, avl)
> - if (mount_bind(opts.path, l->path, l->name, 1, -1))
> - return -1;
> -
> - list_for_each_entry(m, &extras, list)
> - if (mount_bind(opts.path, m->path, m->name, m->readonly, 0))
> - return -1;
> + if (mount_all(opts.path))
> + return -1;
>
> char *mpoint;
> if (asprintf(&mpoint, "%s/old", opts.path) < 0) {
> @@ -205,24 +177,19 @@ static int build_jail_fs()
> return 0;
> }
>
> -#define MAX_ENVP 8
> +#define MAX_ENVP 4
> +#define LD_PRELOAD_SECCOMP "LD_PRELOAD=" PRELOAD_SECCOMP
> static char** build_envp(const char *seccomp)
> {
> static char *envp[MAX_ENVP];
> - static char preload_var[64];
> - static char seccomp_var[64];
> + static char seccomp_var[PATH_MAX];
> + static char preload_var[] = LD_PRELOAD_SECCOMP;
> static char debug_var[] = "LD_DEBUG=all";
> - char *preload_lib = find_lib("libpreload-seccomp.so");
> int count = 0;
>
> - if (seccomp && !preload_lib) {
> - ERROR("failed to add preload-lib to env\n");
> - return NULL;
> - }
> if (seccomp) {
> snprintf(seccomp_var, sizeof(seccomp_var), "SECCOMP_FILE=%s", seccomp);
> envp[count++] = seccomp_var;
> - snprintf(preload_var, sizeof(preload_var), "LD_PRELOAD=%s", preload_lib);
> envp[count++] = preload_var;
> }
> if (debug > 1)
> @@ -279,7 +246,7 @@ static int spawn_jail()
> }
>
> if (build_jail_fs()) {
> - ERROR("failed to build jail fs");
> + ERROR("failed to build jail fs\n");
> exit(EXIT_FAILURE);
> }
>
> @@ -306,24 +273,6 @@ static struct uloop_process jail_process = {
> .cb = jail_process_handler,
> };
>
> -static void add_extra(char *name, int readonly)
> -{
> - struct extra *f;
> -
> - if (*name != '/') {
> - ERROR("%s is not an absolute path\n", name);
> - return;
> - }
> -
> - f = calloc(1, sizeof(struct extra));
> -
> - f->name = basename(name);
> - f->path = dirname(strdup(name));
> - f->readonly = readonly;
> -
> - list_add_tail(&f->list, &extras);
> -}
> -
> int main(int argc, char **argv)
> {
> uid_t uid = getuid();
> @@ -338,6 +287,7 @@ int main(int argc, char **argv)
> }
>
> umask(022);
> + mount_list_init();
>
> while ((ch = getopt(argc, argv, OPT_ARGS)) != -1) {
> switch (ch) {
> @@ -358,11 +308,11 @@ int main(int argc, char **argv)
> break;
> case 'S':
> opts.seccomp = optarg;
> - add_extra(optarg, 1);
> + add_path_and_deps(optarg, 1, -1);
> break;
> case 'C':
> opts.capabilities = optarg;
> - add_extra(optarg, 1);
> + add_path_and_deps(optarg, 1, -1);
> break;
> case 'P':
> opts.namespace = 1;
> @@ -373,19 +323,19 @@ int main(int argc, char **argv)
> break;
> case 'r':
> opts.namespace = 1;
> - add_extra(optarg, 1);
> + add_path_and_deps(optarg, 1, 0);
> break;
> case 'w':
> opts.namespace = 1;
> - add_extra(optarg, 0);
> + add_path_and_deps(optarg, 0, 0);
> break;
> case 'u':
> opts.namespace = 1;
> - add_extra(ubus, 0);
> + add_path_and_deps(ubus, 0, -1);
> break;
> case 'l':
> opts.namespace = 1;
> - add_extra(log, 0);
> + add_path_and_deps(log, 0, -1);
> break;
> }
> }
> diff --git a/jail/jail.h b/jail/jail.h
> new file mode 100644
> index 0000000..fc69ef6
> --- /dev/null
> +++ b/jail/jail.h
> @@ -0,0 +1,18 @@
> +/*
> + * Copyright (C) 2015 Etienne Champetier <champetier.etienne at gmail.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU Lesser General Public License version 2.1
> + * 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 more details.
> + */
> +
> +#ifndef _JAIL_H__
> +
> +int mount_bind(const char *root, const char *path, int readonly, int error);
> +
> +#endif
>
_______________________________________________
openwrt-devel mailing list
openwrt-devel at lists.openwrt.org
https://lists.openwrt.org/cgi-bin/mailman/listinfo/openwrt-devel
More information about the openwrt-devel
mailing list