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systemd/src/network/networkd-netdev.c
Lennart Poettering 4afd3348c7 tree-wide: expose "p"-suffix unref calls in public APIs to make gcc cleanup easy 
GLIB has recently started to officially support the gcc cleanup
attribute in its public API, hence let's do the same for our APIs.

With this patch we'll define an xyz_unrefp() call for each public
xyz_unref() call, to make it easy to use inside a
__attribute__((cleanup())) expression. Then, all code is ported over to
make use of this.

The new calls are also documented in the man pages, with examples how to
use them (well, I only added docs where the _unref() call itself already
had docs, and the examples, only cover sd_bus_unrefp() and
sd_event_unrefp()).

This also renames sd_lldp_free() to sd_lldp_unref(), since that's how we
tend to call our destructors these days.

Note that this defines no public macro that wraps gcc's attribute and
makes it easier to use. While I think it's our duty in the library to
make our stuff easy to use, I figure it's not our duty to make gcc's own
features easy to use on its own. Most likely, client code which wants to
make use of this should define its own:

       #define _cleanup_(function) __attribute__((cleanup(function)))

Or similar, to make the gcc feature easier to use.

Making this logic public has the benefit that we can remove three header
files whose only purpose was to define these functions internally.

See #2008.
2015-11-27 19:19:36 +01:00

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/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
/***
This file is part of systemd.
Copyright 2013 Tom Gundersen <teg@jklm.no>
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 <net/if.h>
#include "alloc-util.h"
#include "conf-files.h"
#include "conf-parser.h"
#include "fd-util.h"
#include "list.h"
#include "netlink-util.h"
#include "network-internal.h"
#include "networkd-netdev.h"
#include "networkd.h"
#include "siphash24.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"
const NetDevVTable * const netdev_vtable[_NETDEV_KIND_MAX] = {
[NETDEV_KIND_BRIDGE] = &bridge_vtable,
[NETDEV_KIND_BOND] = &bond_vtable,
[NETDEV_KIND_VLAN] = &vlan_vtable,
[NETDEV_KIND_MACVLAN] = &macvlan_vtable,
[NETDEV_KIND_MACVTAP] = &macvtap_vtable,
[NETDEV_KIND_IPVLAN] = &ipvlan_vtable,
[NETDEV_KIND_VXLAN] = &vxlan_vtable,
[NETDEV_KIND_IPIP] = &ipip_vtable,
[NETDEV_KIND_GRE] = &gre_vtable,
[NETDEV_KIND_GRETAP] = &gretap_vtable,
[NETDEV_KIND_IP6GRE] = &ip6gre_vtable,
[NETDEV_KIND_IP6GRETAP] = &ip6gretap_vtable,
[NETDEV_KIND_SIT] = &sit_vtable,
[NETDEV_KIND_VTI] = &vti_vtable,
[NETDEV_KIND_VTI6] = &vti6_vtable,
[NETDEV_KIND_VETH] = &veth_vtable,
[NETDEV_KIND_DUMMY] = &dummy_vtable,
[NETDEV_KIND_TUN] = &tun_vtable,
[NETDEV_KIND_TAP] = &tap_vtable,
[NETDEV_KIND_IP6TNL] = &ip6tnl_vtable,
};
static const char* const netdev_kind_table[_NETDEV_KIND_MAX] = {
[NETDEV_KIND_BRIDGE] = "bridge",
[NETDEV_KIND_BOND] = "bond",
[NETDEV_KIND_VLAN] = "vlan",
[NETDEV_KIND_MACVLAN] = "macvlan",
[NETDEV_KIND_MACVTAP] = "macvtap",
[NETDEV_KIND_IPVLAN] = "ipvlan",
[NETDEV_KIND_VXLAN] = "vxlan",
[NETDEV_KIND_IPIP] = "ipip",
[NETDEV_KIND_GRE] = "gre",
[NETDEV_KIND_GRETAP] = "gretap",
[NETDEV_KIND_IP6GRE] = "ip6gre",
[NETDEV_KIND_IP6GRETAP] = "ip6gretap",
[NETDEV_KIND_SIT] = "sit",
[NETDEV_KIND_VETH] = "veth",
[NETDEV_KIND_VTI] = "vti",
[NETDEV_KIND_VTI6] = "vti6",
[NETDEV_KIND_DUMMY] = "dummy",
[NETDEV_KIND_TUN] = "tun",
[NETDEV_KIND_TAP] = "tap",
[NETDEV_KIND_IP6TNL] = "ip6tnl",
};
DEFINE_STRING_TABLE_LOOKUP(netdev_kind, NetDevKind);
DEFINE_CONFIG_PARSE_ENUM(config_parse_netdev_kind, netdev_kind, NetDevKind, "Failed to parse netdev kind");
static void netdev_cancel_callbacks(NetDev *netdev) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
netdev_join_callback *callback;
if (!netdev)
return;
rtnl_message_new_synthetic_error(-ENODEV, 0, &m);
while ((callback = netdev->callbacks)) {
if (m) {
assert(callback->link);
assert(callback->callback);
assert(netdev->manager);
assert(netdev->manager->rtnl);
callback->callback(netdev->manager->rtnl, m, callback->link);
}
LIST_REMOVE(callbacks, netdev->callbacks, callback);
link_unref(callback->link);
free(callback);
}
}
static void netdev_free(NetDev *netdev) {
if (!netdev)
return;
netdev_cancel_callbacks(netdev);
if (netdev->ifname)
hashmap_remove(netdev->manager->netdevs, netdev->ifname);
free(netdev->filename);
free(netdev->description);
free(netdev->ifname);
free(netdev->mac);
condition_free_list(netdev->match_host);
condition_free_list(netdev->match_virt);
condition_free_list(netdev->match_kernel);
condition_free_list(netdev->match_arch);
if (NETDEV_VTABLE(netdev) &&
NETDEV_VTABLE(netdev)->done)
NETDEV_VTABLE(netdev)->done(netdev);
free(netdev);
}
NetDev *netdev_unref(NetDev *netdev) {
if (netdev && (-- netdev->n_ref <= 0))
netdev_free(netdev);
return NULL;
}
NetDev *netdev_ref(NetDev *netdev) {
if (netdev)
assert_se(++ netdev->n_ref >= 2);
return netdev;
}
void netdev_drop(NetDev *netdev) {
if (!netdev || netdev->state == NETDEV_STATE_LINGER)
return;
netdev->state = NETDEV_STATE_LINGER;
log_netdev_debug(netdev, "netdev removed");
netdev_cancel_callbacks(netdev);
netdev_unref(netdev);
return;
}
int netdev_get(Manager *manager, const char *name, NetDev **ret) {
NetDev *netdev;
assert(manager);
assert(name);
assert(ret);
netdev = hashmap_get(manager->netdevs, name);
if (!netdev) {
*ret = NULL;
return -ENOENT;
}
*ret = netdev;
return 0;
}
static int netdev_enter_failed(NetDev *netdev) {
netdev->state = NETDEV_STATE_FAILED;
netdev_cancel_callbacks(netdev);
return 0;
}
static int netdev_enslave_ready(NetDev *netdev, Link* link, sd_netlink_message_handler_t callback) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *req = NULL;
int r;
assert(netdev);
assert(netdev->state == NETDEV_STATE_READY);
assert(netdev->manager);
assert(netdev->manager->rtnl);
assert(IN_SET(netdev->kind, NETDEV_KIND_BRIDGE, NETDEV_KIND_BOND));
assert(link);
assert(callback);
r = sd_rtnl_message_new_link(netdev->manager->rtnl, &req, RTM_SETLINK, link->ifindex);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not allocate RTM_SETLINK message: %m");
r = sd_netlink_message_append_u32(req, IFLA_MASTER, netdev->ifindex);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_MASTER attribute: %m");
r = sd_netlink_call_async(netdev->manager->rtnl, req, callback, link, 0, NULL);
if (r < 0)
return log_netdev_error(netdev, "Could not send rtnetlink message: %m");
link_ref(link);
log_netdev_debug(netdev, "Enslaving link '%s'", link->ifname);
return 0;
}
static int netdev_enter_ready(NetDev *netdev) {
netdev_join_callback *callback, *callback_next;
int r;
assert(netdev);
assert(netdev->ifname);
if (netdev->state != NETDEV_STATE_CREATING)
return 0;
netdev->state = NETDEV_STATE_READY;
log_netdev_info(netdev, "netdev ready");
LIST_FOREACH_SAFE(callbacks, callback, callback_next, netdev->callbacks) {
/* enslave the links that were attempted to be enslaved before the
* link was ready */
r = netdev_enslave_ready(netdev, callback->link, callback->callback);
if (r < 0)
return r;
LIST_REMOVE(callbacks, netdev->callbacks, callback);
link_unref(callback->link);
free(callback);
}
if (NETDEV_VTABLE(netdev)->post_create)
NETDEV_VTABLE(netdev)->post_create(netdev, NULL, NULL);
return 0;
}
/* callback for netdev's created without a backing Link */
static int netdev_create_handler(sd_netlink *rtnl, sd_netlink_message *m, void *userdata) {
_cleanup_netdev_unref_ NetDev *netdev = userdata;
int r;
assert(netdev->state != _NETDEV_STATE_INVALID);
r = sd_netlink_message_get_errno(m);
if (r == -EEXIST)
log_netdev_info(netdev, "netdev exists, using existing without changing its parameters");
else if (r < 0) {
log_netdev_warning_errno(netdev, r, "netdev could not be created: %m");
netdev_drop(netdev);
return 1;
}
log_netdev_debug(netdev, "Created");
return 1;
}
int netdev_enslave(NetDev *netdev, Link *link, sd_netlink_message_handler_t callback) {
int r;
assert(netdev);
assert(netdev->manager);
assert(netdev->manager->rtnl);
assert(IN_SET(netdev->kind, NETDEV_KIND_BRIDGE, NETDEV_KIND_BOND));
if (netdev->state == NETDEV_STATE_READY) {
r = netdev_enslave_ready(netdev, link, callback);
if (r < 0)
return r;
} else if (IN_SET(netdev->state, NETDEV_STATE_LINGER, NETDEV_STATE_FAILED)) {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
r = rtnl_message_new_synthetic_error(-ENODEV, 0, &m);
if (r >= 0)
callback(netdev->manager->rtnl, m, link);
} else {
/* the netdev is not yet read, save this request for when it is */
netdev_join_callback *cb;
cb = new0(netdev_join_callback, 1);
if (!cb)
return log_oom();
cb->callback = callback;
cb->link = link;
link_ref(link);
LIST_PREPEND(callbacks, netdev->callbacks, cb);
log_netdev_debug(netdev, "Will enslave '%s', when ready", link->ifname);
}
return 0;
}
int netdev_set_ifindex(NetDev *netdev, sd_netlink_message *message) {
uint16_t type;
const char *kind;
const char *received_kind;
const char *received_name;
int r, ifindex;
assert(netdev);
assert(message);
r = sd_netlink_message_get_type(message, &type);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not get rtnl message type: %m");
if (type != RTM_NEWLINK) {
log_netdev_error(netdev, "Cannot set ifindex from unexpected rtnl message type.");
return -EINVAL;
}
r = sd_rtnl_message_link_get_ifindex(message, &ifindex);
if (r < 0) {
log_netdev_error_errno(netdev, r, "Could not get ifindex: %m");
netdev_enter_failed(netdev);
return r;
} else if (ifindex <= 0) {
log_netdev_error(netdev, "Got invalid ifindex: %d", ifindex);
netdev_enter_failed(netdev);
return -EINVAL;
}
if (netdev->ifindex > 0) {
if (netdev->ifindex != ifindex) {
log_netdev_error(netdev, "Could not set ifindex to %d, already set to %d",
ifindex, netdev->ifindex);
netdev_enter_failed(netdev);
return -EEXIST;
} else
/* ifindex already set to the same for this netdev */
return 0;
}
r = sd_netlink_message_read_string(message, IFLA_IFNAME, &received_name);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not get IFNAME: %m");
if (!streq(netdev->ifname, received_name)) {
log_netdev_error(netdev, "Received newlink with wrong IFNAME %s", received_name);
netdev_enter_failed(netdev);
return r;
}
r = sd_netlink_message_enter_container(message, IFLA_LINKINFO);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not get LINKINFO: %m");
r = sd_netlink_message_read_string(message, IFLA_INFO_KIND, &received_kind);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not get KIND: %m");
r = sd_netlink_message_exit_container(message);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not exit container: %m");
if (netdev->kind == NETDEV_KIND_TAP)
/* the kernel does not distinguish between tun and tap */
kind = "tun";
else {
kind = netdev_kind_to_string(netdev->kind);
if (!kind) {
log_netdev_error(netdev, "Could not get kind");
netdev_enter_failed(netdev);
return -EINVAL;
}
}
if (!streq(kind, received_kind)) {
log_netdev_error(netdev,
"Received newlink with wrong KIND %s, "
"expected %s", received_kind, kind);
netdev_enter_failed(netdev);
return r;
}
netdev->ifindex = ifindex;
log_netdev_debug(netdev, "netdev has index %d", netdev->ifindex);
netdev_enter_ready(netdev);
return 0;
}
#define HASH_KEY SD_ID128_MAKE(52,e1,45,bd,00,6f,29,96,21,c6,30,6d,83,71,04,48)
int netdev_get_mac(const char *ifname, struct ether_addr **ret) {
_cleanup_free_ struct ether_addr *mac = NULL;
uint64_t result;
size_t l, sz;
uint8_t *v;
int r;
assert(ifname);
assert(ret);
mac = new0(struct ether_addr, 1);
if (!mac)
return -ENOMEM;
l = strlen(ifname);
sz = sizeof(sd_id128_t) + l;
v = alloca(sz);
/* fetch some persistent data unique to the machine */
r = sd_id128_get_machine((sd_id128_t*) v);
if (r < 0)
return r;
/* combine with some data unique (on this machine) to this
* netdev */
memcpy(v + sizeof(sd_id128_t), ifname, l);
/* Let's hash the host machine ID plus the container name. We
* use a fixed, but originally randomly created hash key here. */
result = siphash24(v, sz, HASH_KEY.bytes);
assert_cc(ETH_ALEN <= sizeof(result));
memcpy(mac->ether_addr_octet, &result, ETH_ALEN);
/* see eth_random_addr in the kernel */
mac->ether_addr_octet[0] &= 0xfe; /* clear multicast bit */
mac->ether_addr_octet[0] |= 0x02; /* set local assignment bit (IEEE802) */
*ret = mac;
mac = NULL;
return 0;
}
static int netdev_create(NetDev *netdev, Link *link,
sd_netlink_message_handler_t callback) {
int r;
assert(netdev);
assert(!link || callback);
/* create netdev */
if (NETDEV_VTABLE(netdev)->create) {
assert(!link);
r = NETDEV_VTABLE(netdev)->create(netdev);
if (r < 0)
return r;
log_netdev_debug(netdev, "Created");
} else {
_cleanup_(sd_netlink_message_unrefp) sd_netlink_message *m = NULL;
r = sd_rtnl_message_new_link(netdev->manager->rtnl, &m, RTM_NEWLINK, 0);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not allocate RTM_NEWLINK message: %m");
r = sd_netlink_message_append_string(m, IFLA_IFNAME, netdev->ifname);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_IFNAME, attribute: %m");
if (netdev->mac) {
r = sd_netlink_message_append_ether_addr(m, IFLA_ADDRESS, netdev->mac);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_ADDRESS attribute: %m");
}
if (netdev->mtu) {
r = sd_netlink_message_append_u32(m, IFLA_MTU, netdev->mtu);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_MTU attribute: %m");
}
if (link) {
r = sd_netlink_message_append_u32(m, IFLA_LINK, link->ifindex);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_LINK attribute: %m");
}
r = sd_netlink_message_open_container(m, IFLA_LINKINFO);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_LINKINFO attribute: %m");
r = sd_netlink_message_open_container_union(m, IFLA_INFO_DATA, netdev_kind_to_string(netdev->kind));
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_INFO_DATA attribute: %m");
if (NETDEV_VTABLE(netdev)->fill_message_create) {
r = NETDEV_VTABLE(netdev)->fill_message_create(netdev, link, m);
if (r < 0)
return r;
}
r = sd_netlink_message_close_container(m);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_LINKINFO attribute: %m");
r = sd_netlink_message_close_container(m);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not append IFLA_LINKINFO attribute: %m");
if (link) {
r = sd_netlink_call_async(netdev->manager->rtnl, m, callback, link, 0, NULL);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not send rtnetlink message: %m");
link_ref(link);
} else {
r = sd_netlink_call_async(netdev->manager->rtnl, m, netdev_create_handler, netdev, 0, NULL);
if (r < 0)
return log_netdev_error_errno(netdev, r, "Could not send rtnetlink message: %m");
netdev_ref(netdev);
}
netdev->state = NETDEV_STATE_CREATING;
log_netdev_debug(netdev, "Creating");
}
return 0;
}
/* the callback must be called, possibly after a timeout, as otherwise the Link will hang */
int netdev_join(NetDev *netdev, Link *link, sd_netlink_message_handler_t callback) {
int r;
assert(netdev);
assert(netdev->manager);
assert(netdev->manager->rtnl);
assert(NETDEV_VTABLE(netdev));
switch (NETDEV_VTABLE(netdev)->create_type) {
case NETDEV_CREATE_MASTER:
r = netdev_enslave(netdev, link, callback);
if (r < 0)
return r;
break;
case NETDEV_CREATE_STACKED:
r = netdev_create(netdev, link, callback);
if (r < 0)
return r;
break;
default:
assert_not_reached("Can not join independent netdev");
}
return 0;
}
static int netdev_load_one(Manager *manager, const char *filename) {
_cleanup_netdev_unref_ NetDev *netdev = NULL;
_cleanup_free_ NetDev *netdev_raw = NULL;
_cleanup_fclose_ FILE *file = NULL;
int r;
assert(manager);
assert(filename);
file = fopen(filename, "re");
if (!file) {
if (errno == ENOENT)
return 0;
else
return -errno;
}
if (null_or_empty_fd(fileno(file))) {
log_debug("Skipping empty file: %s", filename);
return 0;
}
netdev_raw = new0(NetDev, 1);
if (!netdev_raw)
return log_oom();
netdev_raw->kind = _NETDEV_KIND_INVALID;
r = config_parse(NULL, filename, file,
"Match\0NetDev\0",
config_item_perf_lookup, network_netdev_gperf_lookup,
true, false, true, netdev_raw);
if (r < 0)
return r;
r = fseek(file, 0, SEEK_SET);
if (r < 0)
return -errno;
/* skip out early if configuration does not match the environment */
if (net_match_config(NULL, NULL, NULL, NULL, NULL,
netdev_raw->match_host, netdev_raw->match_virt,
netdev_raw->match_kernel, netdev_raw->match_arch,
NULL, NULL, NULL, NULL, NULL, NULL) <= 0)
return 0;
if (!NETDEV_VTABLE(netdev_raw)) {
log_warning("NetDev with invalid Kind configured in %s. Ignoring", filename);
return 0;
}
if (!netdev_raw->ifname) {
log_warning("NetDev without Name configured in %s. Ignoring", filename);
return 0;
}
netdev = malloc0(NETDEV_VTABLE(netdev_raw)->object_size);
if (!netdev)
return log_oom();
netdev->n_ref = 1;
netdev->manager = manager;
netdev->state = _NETDEV_STATE_INVALID;
netdev->kind = netdev_raw->kind;
netdev->ifname = netdev_raw->ifname;
if (NETDEV_VTABLE(netdev)->init)
NETDEV_VTABLE(netdev)->init(netdev);
r = config_parse(NULL, filename, file,
NETDEV_VTABLE(netdev)->sections,
config_item_perf_lookup, network_netdev_gperf_lookup,
false, false, false, netdev);
if (r < 0)
return r;
/* verify configuration */
if (NETDEV_VTABLE(netdev)->config_verify) {
r = NETDEV_VTABLE(netdev)->config_verify(netdev, filename);
if (r < 0)
return 0;
}
netdev->filename = strdup(filename);
if (!netdev->filename)
return log_oom();
if (!netdev->mac) {
r = netdev_get_mac(netdev->ifname, &netdev->mac);
if (r < 0)
return log_error_errno(r, "Failed to generate predictable MAC address for %s: %m", netdev->ifname);
}
r = hashmap_put(netdev->manager->netdevs, netdev->ifname, netdev);
if (r < 0)
return r;
LIST_HEAD_INIT(netdev->callbacks);
log_netdev_debug(netdev, "loaded %s", netdev_kind_to_string(netdev->kind));
switch (NETDEV_VTABLE(netdev)->create_type) {
case NETDEV_CREATE_MASTER:
case NETDEV_CREATE_INDEPENDENT:
r = netdev_create(netdev, NULL, NULL);
if (r < 0)
return 0;
break;
default:
break;
}
netdev = NULL;
return 0;
}
int netdev_load(Manager *manager) {
_cleanup_strv_free_ char **files = NULL;
NetDev *netdev;
char **f;
int r;
assert(manager);
while ((netdev = hashmap_first(manager->netdevs)))
netdev_unref(netdev);
r = conf_files_list_strv(&files, ".netdev", NULL, network_dirs);
if (r < 0)
return log_error_errno(r, "Failed to enumerate netdev files: %m");
STRV_FOREACH_BACKWARDS(f, files) {
r = netdev_load_one(manager, *f);
if (r < 0)
return r;
}
return 0;
}
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