AC_ARG_ENABLE(seccomp, AS_HELP_STRING([--disable-seccomp], [Disable optional SECCOMP support]))
if test "x$enable_seccomp" != "xno"; then
PKG_CHECK_MODULES(SECCOMP, [libseccomp >= 1.0.0],
- [AC_DEFINE(HAVE_SECCOMP, 1, [Define if seccomp is available]) have_seccomp=yes],
+ [AC_DEFINE(HAVE_SECCOMP, 1, [Define if seccomp is available])
+ have_seccomp=yes
+ M4_DEFINES="$M4_DEFINES -DHAVE_SECCOMP"],
[have_seccomp=no])
if test "x$have_seccomp" = "xno" -a "x$enable_seccomp" = "xyes"; then
AC_MSG_ERROR([*** seccomp support requested but libraries not found])
list of system call
names. If this setting is used, all
system calls executed by the unit
- process except for the listed ones
+ processes except for the listed ones
will result in immediate process
termination with the
<constant>SIGSYS</constant> signal
prior assignments will have no
effect.</para>
- <para>If you specify both types of this option
- (i.e. whitelisting and blacklisting) the first
- encountered will take precedence and will
- dictate the default action (termination
- or approval of a system call). Then the
- next occurrences of this option will add or
- delete the listed system calls from the set
- of the filtered system calls, depending of
- its type and the default action (e.g. You
- have started with a whitelisting of <function>
- read</function> and <function>write</function>
- and right after it add a blacklisting of
- <function>write</function>, then <function>
- write</function> will be removed from the set)
+ <para>If you specify both types of
+ this option (i.e. whitelisting and
+ blacklisting) the first encountered
+ will take precedence and will dictate
+ the default action (termination or
+ approval of a system call). Then the
+ next occurrences of this option will
+ add or delete the listed system calls
+ from the set of the filtered system
+ calls, depending of its type and the
+ default action (e.g. You have started
+ with a whitelisting of
+ <function>read</function> and
+ <function>write</function> and right
+ after it add a blacklisting of
+ <function>write</function>, then
+ <function>write</function> will be
+ removed from the set).
</para></listitem>
</varlistentry>
+ <varlistentry>
+ <term><varname>SystemCallErrorNumber=</varname></term>
+
+ <listitem><para>Takes an
+ <literal>errno</literal> error number
+ name to return when the system call
+ filter configured with
+ <varname>SystemCallFilter=</varname>
+ is triggered, instead of terminating
+ the process immediately. Takes an
+ error name such as
+ <literal>EPERM</literal>,
+ <literal>EACCES</literal> or
+ <literal>EUCLEAN</literal>. When this
+ setting is not used, or when the empty
+ string is assigned the process will be
+ terminated immediately when the filter
+ is triggered.</para></listitem>
+ </varlistentry>
+
</variablelist>
</refsect1>
void *userdata,
sd_bus_error *error) {
+ ExecContext *c = userdata;
+ _cleanup_strv_free_ char **l = NULL;
+ _cleanup_free_ char *t = NULL;
+ Iterator i;
+ void *id;
+ int r;
+
+ assert(bus);
+ assert(reply);
+ assert(c);
+
+ SET_FOREACH(id, c->syscall_filter, i) {
+ char *name;
+
+ name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(id) - 1);
+ if (!name)
+ continue;
+
+ r = strv_push(&l, name);
+ if (r < 0) {
+ free(name);
+ return -ENOMEM;
+ }
+ }
+
+ strv_sort(l);
+
+ t = strv_join(l, " ");
+ if (!t)
+ return -ENOMEM;
+
+ if (!c->syscall_whitelist) {
+ char *d;
+
+ d = strappend("~", t);
+ if (!d)
+ return -ENOMEM;
+
+ free(t);
+ t = d;
+ }
+
+ return sd_bus_message_append(reply, "s", t);
+}
+
+static int property_get_syscall_errno(
+ sd_bus *bus,
+ const char *path,
+ const char *interface,
+ const char *property,
+ sd_bus_message *reply,
+ void *userdata,
+ sd_bus_error *error) {
+
ExecContext *c = userdata;
assert(bus);
assert(reply);
assert(c);
- return sd_bus_message_append(reply, "s", c->syscall_filter_string);
+ return sd_bus_message_append(reply, "i", (int32_t) c->syscall_errno);
}
const sd_bus_vtable bus_exec_vtable[] = {
SD_BUS_PROPERTY("IgnoreSIGPIPE", "b", bus_property_get_bool, offsetof(ExecContext, ignore_sigpipe), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("NoNewPrivileges", "b", bus_property_get_bool, offsetof(ExecContext, no_new_privileges), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("SystemCallFilter", "s", property_get_syscall_filter, 0, SD_BUS_VTABLE_PROPERTY_CONST),
+ SD_BUS_PROPERTY("SystemCallErrorNumber", "i", property_get_syscall_errno, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_VTABLE_END
};
#include <sys/poll.h>
#include <glob.h>
#include <libgen.h>
-#ifdef HAVE_SECCOMP
-#include <seccomp.h>
-
-#include "set.h"
-#endif
#undef basename
#ifdef HAVE_PAM
#include <selinux/selinux.h>
#endif
+#ifdef HAVE_SECCOMP
+#include <seccomp.h>
+#endif
+
#include "execute.h"
#include "strv.h"
#include "macro.h"
#include "unit.h"
#include "async.h"
#include "selinux-util.h"
+#include "errno-list.h"
#define IDLE_TIMEOUT_USEC (5*USEC_PER_SEC)
#define IDLE_TIMEOUT2_USEC (1*USEC_PER_SEC)
}
#ifdef HAVE_SECCOMP
+
static int apply_seccomp(ExecContext *c) {
- uint32_t action = SCMP_ACT_ALLOW;
+ uint32_t negative_action, action;
+ scmp_filter_ctx *seccomp;
Iterator i;
void *id;
+ int r;
assert(c);
- c->syscall_filter = seccomp_init(c->syscall_filter_default_action);
- if (!c->syscall_filter)
- return -1;
+ negative_action = c->syscall_errno == 0 ? SCMP_ACT_KILL : SCMP_ACT_ERRNO(c->syscall_errno);
+
+ seccomp = seccomp_init(c->syscall_whitelist ? negative_action : SCMP_ACT_ALLOW);
+ if (!seccomp)
+ return -ENOMEM;
- if (c->syscall_filter_default_action == SCMP_ACT_ALLOW)
- action = SCMP_ACT_KILL;
+ action = c->syscall_whitelist ? SCMP_ACT_ALLOW : negative_action;
- SET_FOREACH(id, c->filtered_syscalls, i) {
- int r = seccomp_rule_add(c->syscall_filter, action, PTR_TO_INT(id) - 1, 0);
+ SET_FOREACH(id, c->syscall_filter, i) {
+ r = seccomp_rule_add(seccomp, action, PTR_TO_INT(id) - 1, 0);
if (r < 0) {
- log_error("Failed to add syscall filter");
+ seccomp_release(seccomp);
return r;
}
}
- return seccomp_load(c->syscall_filter);
+ r = seccomp_load(seccomp);
+ seccomp_release(seccomp);
+
+ return r;
}
#endif
}
#ifdef HAVE_SECCOMP
- if (context->filtered_syscalls) {
+ if (context->syscall_filter) {
err = apply_seccomp(context);
if (err < 0) {
r = EXIT_SECCOMP;
}
}
#endif
+
#ifdef HAVE_SELINUX
if (context->selinux_context && use_selinux()) {
bool ignore;
free(c->selinux_context);
c->selinux_context = NULL;
- free(c->syscall_filter);
- c->syscall_filter = NULL;
-
- free(c->syscall_filter_string);
- c->syscall_filter_string = NULL;
-
#ifdef HAVE_SECCOMP
- if (c->syscall_filter) {
- seccomp_release(c->syscall_filter);
- c->syscall_filter = NULL;
- }
- set_free(c->filtered_syscalls);
- c->filtered_syscalls = NULL;
+ set_free(c->syscall_filter);
+ c->syscall_filter = NULL;
#endif
}
fprintf(f,
"%sSELinuxContext: %s\n",
prefix, c->selinux_context);
+
+ if (c->syscall_filter) {
+ Iterator j;
+ void *id;
+ bool first = true;
+
+ fprintf(f,
+ "%sSystemCallFilter: \n",
+ prefix);
+
+ if (!c->syscall_whitelist)
+ fputc('~', f);
+
+ SET_FOREACH(id, c->syscall_filter, j) {
+ _cleanup_free_ char *name = NULL;
+
+ if (first)
+ first = false;
+ else
+ fputc(' ', f);
+
+ name = seccomp_syscall_resolve_num_arch(PTR_TO_INT(id)-1, SCMP_ARCH_NATIVE);
+ fputs(strna(name), f);
+ }
+
+ fputc('\n', f);
+ }
+
+ if (c->syscall_errno != 0)
+ fprintf(f,
+ "%sSystemCallErrorNumber: %s\n",
+ prefix, strna(errno_to_name(c->syscall_errno)));
}
void exec_status_start(ExecStatus *s, pid_t pid) {
* don't enter a trigger loop. */
bool same_pgrp;
-#ifdef HAVE_SECCOMP
- scmp_filter_ctx syscall_filter;
- Set *filtered_syscalls;
- uint32_t syscall_filter_default_action;
-#endif
- char *syscall_filter_string;
+ Set *syscall_filter;
+ int syscall_errno;
+ bool syscall_whitelist:1;
bool oom_score_adjust_set:1;
bool nice_set:1;
$1.CapabilityBoundingSet, config_parse_bounding_set, 0, offsetof($1, exec_context.capability_bounding_set_drop)
$1.TimerSlackNSec, config_parse_nsec, 0, offsetof($1, exec_context.timer_slack_nsec)
$1.NoNewPrivileges, config_parse_bool, 0, offsetof($1, exec_context.no_new_privileges)
-$1.SystemCallFilter, config_parse_syscall_filter, 0, offsetof($1, exec_context)
+m4_ifdef(`HAVE_SECCOMP',
+`$1.SystemCallFilter, config_parse_syscall_filter, 0, offsetof($1, exec_context)
+$1.SystemCallErrorNumber, config_parse_syscall_errno, 0, offsetof($1, exec_context)',
+`$1.SystemCallFilter, config_parse_warn_compat, 0, 0
+$1.SystemCallErrorNumber, config_parse_warn_compat, 0, 0')
$1.LimitCPU, config_parse_limit, RLIMIT_CPU, offsetof($1, exec_context.rlimit)
$1.LimitFSIZE, config_parse_limit, RLIMIT_FSIZE, offsetof($1, exec_context.rlimit)
$1.LimitDATA, config_parse_limit, RLIMIT_DATA, offsetof($1, exec_context.rlimit)
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/resource.h>
+
#ifdef HAVE_SECCOMP
#include <seccomp.h>
-
-#include "set.h"
#endif
#include "sd-messages.h"
#include "cgroup.h"
#include "bus-util.h"
#include "bus-error.h"
+#include "errno-list.h"
#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP)
-int config_parse_warn_compat(const char *unit,
- const char *filename,
- unsigned line,
- const char *section,
- unsigned section_line,
- const char *lvalue,
- int ltype,
- const char *rvalue,
- void *data,
- void *userdata) {
+int config_parse_warn_compat(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
log_syntax(unit, LOG_DEBUG, filename, line, EINVAL,
"Support for option %s= has been disabled at compile time and is ignored",
}
#ifdef HAVE_SECCOMP
-int config_parse_syscall_filter(const char *unit,
- const char *filename,
- unsigned line,
- const char *section,
- unsigned section_line,
- const char *lvalue,
- int ltype,
- const char *rvalue,
- void *data,
- void *userdata) {
+int config_parse_syscall_filter(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ static const char default_syscalls[] =
+ "execve\0"
+ "exit\0"
+ "exit_group\0"
+ "rt_sigreturn\0"
+ "sigreturn\0";
+
ExecContext *c = data;
Unit *u = userdata;
bool invert = false;
- char *w;
+ char *w, *state;
size_t l;
- char *state;
- _cleanup_strv_free_ char **syscalls = strv_new(NULL, NULL);
- _cleanup_free_ char *sorted_syscalls = NULL;
- uint32_t action = SCMP_ACT_ALLOW;
- Iterator i;
- void *e;
- static char const *default_syscalls[] = {"execve",
- "exit",
- "exit_group",
- "rt_sigreturn",
- "sigreturn",
- NULL};
+ int r;
assert(filename);
assert(lvalue);
if (isempty(rvalue)) {
/* Empty assignment resets the list */
- set_free(c->filtered_syscalls);
- c->filtered_syscalls= NULL;
- free(c->syscall_filter_string);
- c->syscall_filter_string = NULL;
+ set_free(c->syscall_filter);
+ c->syscall_filter = NULL;
+ c->syscall_whitelist = false;
return 0;
}
if (rvalue[0] == '~') {
invert = true;
- action = SCMP_ACT_KILL;
rvalue++;
}
- if (!c->filtered_syscalls) {
- c->filtered_syscalls = set_new(trivial_hash_func, trivial_compare_func);
+ if (!c->syscall_filter) {
+ c->syscall_filter = set_new(trivial_hash_func, trivial_compare_func);
+ if (!c->syscall_filter)
+ return log_oom();
+
if (invert)
- c->syscall_filter_default_action = SCMP_ACT_ALLOW;
+ /* Allow everything but the ones listed */
+ c->syscall_whitelist = false;
else {
- char const **syscall;
+ const char *i;
+
+ /* Allow nothing but the ones listed */
+ c->syscall_whitelist = true;
- c->syscall_filter_default_action = SCMP_ACT_KILL;
+ /* Accept default syscalls if we are on a whitelist */
+ NULSTR_FOREACH(i, default_syscalls) {
+ int id;
- /* accept default syscalls if we are on a whitelist */
- STRV_FOREACH(syscall, default_syscalls) {
- int id = seccomp_syscall_resolve_name(*syscall);
+ id = seccomp_syscall_resolve_name(i);
if (id < 0)
continue;
- set_replace(c->filtered_syscalls, INT_TO_PTR(id + 1));
+ r = set_put(c->syscall_filter, INT_TO_PTR(id + 1));
+ if (r == -EEXIST)
+ continue;
+ if (r < 0)
+ return log_oom();
}
}
}
FOREACH_WORD_QUOTED(w, l, rvalue, state) {
- int id;
_cleanup_free_ char *t = NULL;
+ int id;
t = strndup(w, l);
if (!t)
id = seccomp_syscall_resolve_name(t);
if (id < 0) {
- log_syntax(unit, LOG_ERR, filename, line, EINVAL,
- "Failed to parse syscall, ignoring: %s", t);
+ log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Failed to parse system call, ignoring: %s", t);
continue;
}
- /* If we previously wanted to forbid a syscall
- * and now we want to allow it, then remove it from the list
- * libseccomp will also return -EPERM if we try to add
- * a rule with the same action as the default
+ /* If we previously wanted to forbid a syscall and now
+ * we want to allow it, then remove it from the list
*/
- if (action == c->syscall_filter_default_action)
- set_remove(c->filtered_syscalls, INT_TO_PTR(id + 1));
- else
- set_replace(c->filtered_syscalls, INT_TO_PTR(id + 1));
+ if (!invert == c->syscall_whitelist) {
+ r = set_put(c->syscall_filter, INT_TO_PTR(id + 1));
+ if (r == -EEXIST)
+ continue;
+ if (r < 0)
+ return log_oom();
+ } else
+ set_remove(c->syscall_filter, INT_TO_PTR(id + 1));
}
- SET_FOREACH(e, c->filtered_syscalls, i) {
- char *name = seccomp_syscall_resolve_num_arch(SCMP_ARCH_NATIVE, PTR_TO_INT(e) - 1);
- strv_push(&syscalls, name);
+ c->no_new_privileges = true;
+
+ return 0;
+}
+
+int config_parse_syscall_errno(
+ const char *unit,
+ const char *filename,
+ unsigned line,
+ const char *section,
+ unsigned section_line,
+ const char *lvalue,
+ int ltype,
+ const char *rvalue,
+ void *data,
+ void *userdata) {
+
+ ExecContext *c = data;
+ int e;
+
+ assert(filename);
+ assert(lvalue);
+ assert(rvalue);
+
+ if (isempty(rvalue)) {
+ /* Empty assignment resets to KILL */
+ c->syscall_errno = 0;
+ return 0;
}
- sorted_syscalls = strv_join(strv_sort(syscalls), " ");
- if (invert)
- c->syscall_filter_string = strv_join(STRV_MAKE("~", sorted_syscalls, NULL), "");
- else
- c->syscall_filter_string = strdup(sorted_syscalls);
- c->no_new_privileges = true;
+ e = errno_from_name(rvalue);
+ if (e < 0) {
+ log_syntax(unit, LOG_ERR, filename, line, EINVAL, "Failed to parse error number, ignoring: %s", rvalue);
+ return 0;
+ }
+ c->syscall_errno = e;
return 0;
}
#endif
const ConfigParserCallback callback;
const char *rvalue;
} table[] = {
+#if !defined(HAVE_SYSV_COMPAT) || !defined(HAVE_SECCOMP)
+ { config_parse_warn_compat, "NOTSUPPORTED" },
+#endif
{ config_parse_int, "INTEGER" },
{ config_parse_unsigned, "UNSIGNED" },
{ config_parse_bytes_size, "SIZE" },
{ config_parse_service_restart, "SERVICERESTART" },
#ifdef HAVE_SYSV_COMPAT
{ config_parse_sysv_priority, "SYSVPRIORITY" },
-#else
- { config_parse_warn_compat, "NOTSUPPORTED" },
#endif
{ config_parse_kill_mode, "KILLMODE" },
{ config_parse_kill_signal, "SIGNAL" },
{ config_parse_service_sockets, "SOCKETS" },
{ config_parse_environ, "ENVIRON" },
#ifdef HAVE_SECCOMP
- { config_parse_syscall_filter, "SYSCALL" },
-#else
- { config_parse_warn_compat, "NOTSUPPORTED" },
+ { config_parse_syscall_filter, "SYSCALLS" },
+ { config_parse_syscall_errno, "ERRNO" },
#endif
{ config_parse_cpu_shares, "SHARES" },
{ config_parse_memory_limit, "LIMIT" },
int config_parse_start_limit_action(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_unit_requires_mounts_for(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_syscall_filter(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_syscall_errno(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_environ(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_unit_slice(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
int config_parse_cpu_shares(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
~ianmdlvl / elogind.git / commitdiff