unit-printf.c revision 2cfbd749af308bdbe56edcfed7f3eea0fc2b93d2
/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2010 Lennart Poettering
systemd is free software; you can redistribute it and/or modify it
under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.
systemd 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include "systemd/sd-id128.h"
#include "unit.h"
#include "specifier.h"
#include "path-util.h"
#include "strv.h"
#include "unit-name.h"
#include "unit-printf.h"
#include "macro.h"
#include "cgroup-util.h"
#include "special.h"
static int specifier_prefix_and_instance(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
char *n;
assert(u);
n = unit_name_to_prefix_and_instance(u->id);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_prefix(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
char *n;
assert(u);
n = unit_name_to_prefix(u->id);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_prefix_unescaped(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
_cleanup_free_ char *p = NULL;
char *n;
assert(u);
p = unit_name_to_prefix(u->id);
if (!p)
return -ENOMEM;
n = unit_name_unescape(p);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_instance_unescaped(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
char *n;
assert(u);
if (!u->instance)
return -ENOTSUP;
n = unit_name_unescape(u->instance);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_filename(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
char *n;
assert(u);
if (u->instance)
n = unit_name_path_unescape(u->instance);
else
n = unit_name_to_path(u->id);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_cgroup(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
char *n;
assert(u);
if (u->cgroup_path)
n = strdup(u->cgroup_path);
else
n = unit_default_cgroup_path(u);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_cgroup_root(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
const char *slice;
char *n;
int r;
assert(u);
slice = unit_slice_name(u);
if (specifier == 'R' || !slice)
n = strdup(u->manager->cgroup_root);
else {
_cleanup_free_ char *p = NULL;
r = cg_slice_to_path(slice, &p);
if (r < 0)
return r;
n = strjoin(u->manager->cgroup_root, "/", p, NULL);
if (!n)
return -ENOMEM;
}
*ret = n;
return 0;
}
static int specifier_runtime(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
const char *e;
char *n = NULL;
assert(u);
if (u->manager->running_as == SYSTEMD_SYSTEM)
e = "/run";
else {
e = getenv("XDG_RUNTIME_DIR");
if (!e)
return -ENOTSUP;
}
n = strdup(e);
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_user_name(char specifier, void *data, void *userdata, char **ret) {
char *printed = NULL;
Unit *u = userdata;
ExecContext *c;
int r;
assert(u);
c = unit_get_exec_context(u);
if (!c)
return -ENOTSUP;
if (u->manager->running_as == SYSTEMD_SYSTEM) {
/* We cannot use NSS from PID 1, hence try to make the
* best of it in that case, and fail if we can't help
* it */
if (!c->user || streq(c->user, "root") || streq(c->user, "0"))
printed = strdup(specifier == 'u' ? "root" : "0");
else {
if (specifier == 'u')
printed = strdup(c->user);
else {
uid_t uid;
r = parse_uid(c->user, &uid);
if (r < 0)
return -ENODATA;
asprintf(&printed, "%lu", (unsigned long) uid);
}
}
} else {
_cleanup_free_ char *tmp = NULL;
const char *username = NULL;
uid_t uid;
if (c->user)
username = c->user;
else
/* get USER env from env or our own uid */
username = tmp = getusername_malloc();
/* fish username from passwd */
r = get_user_creds(&username, &uid, NULL, NULL, NULL);
if (r < 0)
return r;
if (specifier == 'u')
printed = strdup(username);
else
asprintf(&printed, "%lu", (unsigned long) uid);
}
if (!printed)
return -ENOMEM;
*ret = printed;
return 0;
}
static int specifier_user_home(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
ExecContext *c;
char *n;
int r;
assert(u);
c = unit_get_exec_context(u);
if (!c)
return -ENOTSUP;
if (u->manager->running_as == SYSTEMD_SYSTEM) {
/* We cannot use NSS from PID 1, hence try to make the
* best of it if we can, but fail if we can't */
if (!c->user || streq(c->user, "root") || streq(c->user, "0"))
n = strdup("/root");
else
return -ENOTSUP;
} else {
/* return HOME if set, otherwise from passwd */
if (!c || !c->user) {
r = get_home_dir(&n);
if (r < 0)
return r;
} else {
const char *username, *home;
username = c->user;
r = get_user_creds(&username, NULL, NULL, &home, NULL);
if (r < 0)
return r;
n = strdup(home);
}
}
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
static int specifier_user_shell(char specifier, void *data, void *userdata, char **ret) {
Unit *u = userdata;
ExecContext *c;
char *n;
int r;
assert(u);
c = unit_get_exec_context(u);
if (!c)
return -ENOTSUP;
if (u->manager->running_as == SYSTEMD_SYSTEM) {
/* We cannot use NSS from PID 1, hence try to make the
* best of it if we can, but fail if we can't */
if (!c->user || streq(c->user, "root") || streq(c->user, "0"))
n = strdup("/bin/sh");
else
return -ENOTSUP;
} else {
/* return /bin/sh for root, otherwise the value from passwd */
if (!c->user) {
r = get_shell(&n);
if (r < 0)
return r;
} else {
const char *username, *shell;
username = c->user;
r = get_user_creds(&username, NULL, NULL, NULL, &shell);
if (r < 0)
return r;
n = strdup(shell);
}
}
if (!n)
return -ENOMEM;
*ret = n;
return 0;
}
int unit_name_printf(Unit *u, const char* format, char **ret) {
/*
* This will use the passed string as format string and
* replace the following specifiers:
*
* %n: the full id of the unit (foo@bar.waldo)
* %N: the id of the unit without the suffix (foo@bar)
* %p: the prefix (foo)
* %i: the instance (bar)
*/
const Specifier table[] = {
{ 'n', specifier_string, u->id },
{ 'N', specifier_prefix_and_instance, NULL },
{ 'p', specifier_prefix, NULL },
{ 'i', specifier_string, u->instance },
{ 0, NULL, NULL }
};
assert(u);
assert(format);
assert(ret);
return specifier_printf(format, table, u, ret);
}
int unit_full_printf(Unit *u, const char *format, char **ret) {
/* This is similar to unit_name_printf() but also supports
* unescaping. Also, adds a couple of additional codes:
*
* %f the the instance if set, otherwise the id
* %c cgroup path of unit
* %r where units in this slice are placed in the cgroup tree
* %R the root of this systemd's instance tree
* %t the runtime directory to place sockets in (e.g. "/run" or $XDG_RUNTIME_DIR)
* %U the UID of the configured user or running user
* %u the username of the configured user or running user
* %h the homedir of the configured user or running user
* %s the shell of the configured user or running user
* %m the machine ID of the running system
* %H the host name of the running system
* %b the boot ID of the running system
* %v `uname -r` of the running system
*/
const Specifier table[] = {
{ 'n', specifier_string, u->id },
{ 'N', specifier_prefix_and_instance, NULL },
{ 'p', specifier_prefix, NULL },
{ 'P', specifier_prefix_unescaped, NULL },
{ 'i', specifier_string, u->instance },
{ 'I', specifier_instance_unescaped, NULL },
{ 'f', specifier_filename, NULL },
{ 'c', specifier_cgroup, NULL },
{ 'r', specifier_cgroup_root, NULL },
{ 'R', specifier_cgroup_root, NULL },
{ 't', specifier_runtime, NULL },
{ 'U', specifier_user_name, NULL },
{ 'u', specifier_user_name, NULL },
{ 'h', specifier_user_home, NULL },
{ 's', specifier_user_shell, NULL },
{ 'm', specifier_machine_id, NULL },
{ 'H', specifier_host_name, NULL },
{ 'b', specifier_boot_id, NULL },
{ 'v', specifier_kernel_release, NULL },
{}
};
assert(u);
assert(format);
assert(ret);
return specifier_printf(format, table, u, ret);
}
int unit_full_printf_strv(Unit *u, char **l, char ***ret) {
size_t n;
char **r, **i, **j;
int q;
/* Applies unit_full_printf to every entry in l */
assert(u);
n = strv_length(l);
r = new(char*, n+1);
if (!r)
return -ENOMEM;
for (i = l, j = r; *i; i++, j++) {
q = unit_full_printf(u, *i, j);
if (q < 0)
goto fail;
}
*j = NULL;
*ret = r;
return 0;
fail:
for (j--; j >= r; j--)
free(*j);
free(r);
return q;
}