core: add new UnsetEnvironment= setting for unit files

With this setting we can explicitly unset specific variables for
processes of a unit, as last step of assembling the environment block
for them. This is useful to fix #6407.

While we are at it, greatly expand the documentation on how the
environment block for forked off processes is assembled.
This commit is contained in:
Lennart Poettering
2017-09-14 15:17:40 +02:00
parent dbbf424c8b
commit 00819cc151
8 changed files with 227 additions and 40 deletions
+43 -1
View File
@@ -758,6 +758,7 @@ const sd_bus_vtable bus_exec_vtable[] = {
SD_BUS_PROPERTY("Environment", "as", NULL, offsetof(ExecContext, environment), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("EnvironmentFiles", "a(sb)", property_get_environment_files, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("PassEnvironment", "as", NULL, offsetof(ExecContext, pass_environment), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("UnsetEnvironment", "as", NULL, offsetof(ExecContext, unset_environment), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("UMask", "u", bus_property_get_mode, offsetof(ExecContext, umask), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("LimitCPU", "t", bus_property_get_rlimit, offsetof(ExecContext, rlimit[RLIMIT_CPU]), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("LimitCPUSoft", "t", bus_property_get_rlimit, offsetof(ExecContext, rlimit[RLIMIT_CPU]), SD_BUS_VTABLE_PROPERTY_CONST),
@@ -1849,6 +1850,47 @@ int bus_exec_context_set_transient_property(
return 1;
} else if (streq(name, "UnsetEnvironment")) {
_cleanup_strv_free_ char **l = NULL, **q = NULL;
r = sd_bus_message_read_strv(message, &l);
if (r < 0)
return r;
r = unit_full_printf_strv(u, l, &q);
if (r < 0)
return r;
if (!strv_env_name_or_assignment_is_valid(q))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid UnsetEnvironment= list.");
if (mode != UNIT_CHECK) {
if (strv_length(q) == 0) {
c->unset_environment = strv_free(c->unset_environment);
unit_write_drop_in_private_format(u, mode, name, "UnsetEnvironment=");
} else {
_cleanup_free_ char *joined = NULL;
char **e;
e = strv_env_merge(2, c->unset_environment, q);
if (!e)
return -ENOMEM;
strv_free(c->unset_environment);
c->unset_environment = e;
/* We write just the new settings out to file, with unresolved specifiers */
joined = strv_join_quoted(l);
if (!joined)
return -ENOMEM;
unit_write_drop_in_private_format(u, mode, name, "UnsetEnvironment=%s", joined);
}
}
return 1;
} else if (streq(name, "TimerSlackNSec")) {
nsec_t n;
@@ -1965,7 +2007,7 @@ int bus_exec_context_set_transient_property(
return r;
if (!strv_env_name_is_valid(l))
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid PassEnvironment block.");
return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid PassEnvironment= block.");
if (mode != UNIT_CHECK) {
if (strv_isempty(l)) {
+19
View File
@@ -1673,8 +1673,10 @@ static int build_pass_environment(const ExecContext *c, char ***ret) {
x = strjoin(*i, "=", v);
if (!x)
return -ENOMEM;
if (!GREEDY_REALLOC(pass_env, n_bufsize, n_env + 2))
return -ENOMEM;
pass_env[n_env++] = x;
pass_env[n_env] = NULL;
x = NULL;
@@ -3031,6 +3033,19 @@ static int exec_child(
#endif
}
if (!strv_isempty(context->unset_environment)) {
char **ee = NULL;
ee = strv_env_delete(accum_env, 1, context->unset_environment);
if (!ee) {
*exit_status = EXIT_MEMORY;
return -ENOMEM;
}
strv_free(accum_env);
accum_env = ee;
}
final_argv = replace_env_argv(argv, accum_env);
if (!final_argv) {
*exit_status = EXIT_MEMORY;
@@ -3222,6 +3237,7 @@ void exec_context_done(ExecContext *c) {
c->environment = strv_free(c->environment);
c->environment_files = strv_free(c->environment_files);
c->pass_environment = strv_free(c->pass_environment);
c->unset_environment = strv_free(c->unset_environment);
for (l = 0; l < ELEMENTSOF(c->rlimit); l++)
c->rlimit[l] = mfree(c->rlimit[l]);
@@ -3582,6 +3598,9 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) {
STRV_FOREACH(e, c->pass_environment)
fprintf(f, "%sPassEnvironment: %s\n", prefix, *e);
STRV_FOREACH(e, c->unset_environment)
fprintf(f, "%sUnsetEnvironment: %s\n", prefix, *e);
fprintf(f, "%sRuntimeDirectoryPreserve: %s\n", prefix, exec_preserve_mode_to_string(c->runtime_directory_preserve_mode));
for (dt = 0; dt < _EXEC_DIRECTORY_MAX; dt++) {
+1
View File
@@ -133,6 +133,7 @@ struct ExecContext {
char **environment;
char **environment_files;
char **pass_environment;
char **unset_environment;
struct rlimit *rlimit[_RLIMIT_MAX];
char *working_directory, *root_directory, *root_image;
+1
View File
@@ -35,6 +35,7 @@ $1.UMask, config_parse_mode, 0,
$1.Environment, config_parse_environ, 0, offsetof($1, exec_context.environment)
$1.EnvironmentFile, config_parse_unit_env_file, 0, offsetof($1, exec_context.environment_files)
$1.PassEnvironment, config_parse_pass_environ, 0, offsetof($1, exec_context.pass_environment)
$1.UnsetEnvironment, config_parse_unset_environ, 0, offsetof($1, exec_context.unset_environment)
$1.DynamicUser, config_parse_bool, true, offsetof($1, exec_context.dynamic_user)
$1.StandardInput, config_parse_exec_input, 0, offsetof($1, exec_context)
$1.StandardOutput, config_parse_exec_output, 0, offsetof($1, exec_context)
+90 -10
View File
@@ -2174,16 +2174,17 @@ int config_parse_environ(const char *unit,
}
}
int config_parse_pass_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_pass_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) {
const char *whole_rvalue = rvalue;
char*** passenv = data;
@@ -2238,6 +2239,85 @@ int config_parse_pass_environ(const char *unit,
return 0;
}
int config_parse_unset_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) {
_cleanup_strv_free_ char **n = NULL;
const char *whole_rvalue = rvalue;
size_t nlen = 0, nbufsize = 0;
char*** unsetenv = data;
Unit *u = userdata;
int r;
assert(filename);
assert(lvalue);
assert(rvalue);
assert(data);
if (isempty(rvalue)) {
/* Empty assignment resets the list */
*unsetenv = strv_free(*unsetenv);
return 0;
}
for (;;) {
_cleanup_free_ char *word = NULL, *k = NULL;
r = extract_first_word(&rvalue, &word, NULL, EXTRACT_QUOTES);
if (r == 0)
break;
if (r == -ENOMEM)
return log_oom();
if (r < 0) {
log_syntax(unit, LOG_ERR, filename, line, r,
"Trailing garbage in %s, ignoring: %s", lvalue, whole_rvalue);
break;
}
if (u) {
r = unit_full_printf(u, word, &k);
if (r < 0) {
log_syntax(unit, LOG_ERR, filename, line, r,
"Failed to resolve specifiers, ignoring: %s", word);
continue;
}
} else {
k = word;
word = NULL;
}
if (!env_assignment_is_valid(k) && !env_name_is_valid(k)) {
log_syntax(unit, LOG_ERR, filename, line, 0,
"Invalid environment name or assignment %s, ignoring: %s", lvalue, k);
continue;
}
if (!GREEDY_REALLOC(n, nbufsize, nlen + 2))
return log_oom();
n[nlen++] = k;
n[nlen] = NULL;
k = NULL;
}
if (n) {
r = strv_extend_strv(unsetenv, n, true);
if (r < 0)
return r;
}
return 0;
}
int config_parse_ip_tos(const char *unit,
const char *filename,
unsigned line,
+1
View File
@@ -79,6 +79,7 @@ int config_parse_syscall_archs(const char *unit, const char *filename, unsigned
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_pass_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_unset_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_weight(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);
+6 -1
View File
@@ -641,7 +641,7 @@ int bus_append_unit_property_assignment(sd_bus_message *m, const char *assignmen
r = sd_bus_message_append(m, "v", "i", (int32_t) q);
} else if (STR_IN_SET(field, "Environment", "PassEnvironment")) {
} else if (STR_IN_SET(field, "Environment", "UnsetEnvironment", "PassEnvironment")) {
const char *p;
r = sd_bus_message_open_container(m, 'v', "as");
@@ -668,6 +668,11 @@ int bus_append_unit_property_assignment(sd_bus_message *m, const char *assignmen
log_error("Invalid environment assignment: %s", word);
return -EINVAL;
}
} else if (streq(field, "UnsetEnvironment")) {
if (!env_assignment_is_valid(word) && !env_name_is_valid(word)) {
log_error("Invalid environment name or assignment: %s", word);
return -EINVAL;
}
} else { /* PassEnvironment */
if (!env_name_is_valid(word)) {
log_error("Invalid environment variable name: %s", word);