tor/src/common/sandbox.h
2017-09-15 16:24:44 -04:00

175 lines
4.8 KiB
C

/* Copyright (c) 2001 Matej Pfajfar.
* Copyright (c) 2001-2004, Roger Dingledine.
* Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
* Copyright (c) 2007-2017, The Tor Project, Inc. */
/* See LICENSE for licensing information */
/**
* \file sandbox.h
* \brief Header file for sandbox.c.
**/
#ifndef SANDBOX_H_
#define SANDBOX_H_
#include "orconfig.h"
#include "torint.h"
#ifndef SYS_SECCOMP
/**
* Used by SIGSYS signal handler to check if the signal was issued due to a
* seccomp2 filter violation.
*/
#define SYS_SECCOMP 1
#endif /* !defined(SYS_SECCOMP) */
#if defined(HAVE_SECCOMP_H) && defined(__linux__)
#define USE_LIBSECCOMP
#endif
struct sandbox_cfg_elem;
/** Typedef to structure used to manage a sandbox configuration. */
typedef struct sandbox_cfg_elem sandbox_cfg_t;
/**
* Linux definitions
*/
#ifdef USE_LIBSECCOMP
#include <sys/ucontext.h>
#include <seccomp.h>
#include <netdb.h>
#define PARAM_PTR 0
#define PARAM_NUM 1
/**
* Enum used to manage the type of the implementation for general purpose.
*/
typedef enum {
/** Libseccomp implementation based on seccomp2*/
LIBSECCOMP2 = 0
} SB_IMPL;
/**
* Configuration parameter structure associated with the LIBSECCOMP2
* implementation.
*/
typedef struct smp_param {
/** syscall associated with parameter. */
int syscall;
/** parameter value. */
char *value;
/** parameter value, second argument. */
char *value2;
/** parameter flag (0 = not protected, 1 = protected). */
int prot;
} smp_param_t;
/**
* Structure used to manage a sandbox configuration.
*
* It is implemented as a linked list of parameters. Currently only controls
* parameters for open, openat, execve, stat64.
*/
struct sandbox_cfg_elem {
/** Sandbox implementation which dictates the parameter type. */
SB_IMPL implem;
/** Configuration parameter. */
smp_param_t *param;
/** Next element of the configuration*/
struct sandbox_cfg_elem *next;
};
/** Function pointer defining the prototype of a filter function.*/
typedef int (*sandbox_filter_func_t)(scmp_filter_ctx ctx,
sandbox_cfg_t *filter);
/** Type that will be used in step 3 in order to manage multiple sandboxes.*/
typedef struct {
/** function pointers associated with the filter */
sandbox_filter_func_t *filter_func;
/** filter function pointer parameters */
sandbox_cfg_t *filter_dynamic;
} sandbox_t;
#endif /* defined(USE_LIBSECCOMP) */
#ifdef USE_LIBSECCOMP
/** Pre-calls getaddrinfo in order to pre-record result. */
int sandbox_add_addrinfo(const char *addr);
struct addrinfo;
/** Replacement for getaddrinfo(), using pre-recorded results. */
int sandbox_getaddrinfo(const char *name, const char *servname,
const struct addrinfo *hints,
struct addrinfo **res);
void sandbox_freeaddrinfo(struct addrinfo *addrinfo);
void sandbox_free_getaddrinfo_cache(void);
#else /* !(defined(USE_LIBSECCOMP)) */
#define sandbox_getaddrinfo(name, servname, hints, res) \
getaddrinfo((name),(servname), (hints),(res))
#define sandbox_add_addrinfo(name) \
((void)(name))
#define sandbox_freeaddrinfo(addrinfo) \
freeaddrinfo((addrinfo))
#define sandbox_free_getaddrinfo_cache()
#endif /* defined(USE_LIBSECCOMP) */
#ifdef USE_LIBSECCOMP
/** Returns a registered protected string used with the sandbox, given that
* it matches the parameter.
*/
const char* sandbox_intern_string(const char *param);
#else /* !(defined(USE_LIBSECCOMP)) */
#define sandbox_intern_string(s) (s)
#endif /* defined(USE_LIBSECCOMP) */
/** Creates an empty sandbox configuration file.*/
sandbox_cfg_t * sandbox_cfg_new(void);
/**
* Function used to add a open allowed filename to a supplied configuration.
* The (char*) specifies the path to the allowed file; we take ownership
* of the pointer.
*/
int sandbox_cfg_allow_open_filename(sandbox_cfg_t **cfg, char *file);
int sandbox_cfg_allow_chmod_filename(sandbox_cfg_t **cfg, char *file);
int sandbox_cfg_allow_chown_filename(sandbox_cfg_t **cfg, char *file);
/* DOCDOC */
int sandbox_cfg_allow_rename(sandbox_cfg_t **cfg, char *file1, char *file2);
/**
* Function used to add a openat allowed filename to a supplied configuration.
* The (char*) specifies the path to the allowed file; we steal the pointer to
* that file.
*/
int sandbox_cfg_allow_openat_filename(sandbox_cfg_t **cfg, char *file);
/**
* Function used to add a stat/stat64 allowed filename to a configuration.
* The (char*) specifies the path to the allowed file; that pointer is stolen.
*/
int sandbox_cfg_allow_stat_filename(sandbox_cfg_t **cfg, char *file);
/** Function used to initialise a sandbox configuration.*/
int sandbox_init(sandbox_cfg_t* cfg);
/** Return true iff the sandbox is turned on. */
int sandbox_is_active(void);
void sandbox_disable_getaddrinfo_cache(void);
#endif /* !defined(SANDBOX_H_) */