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Commit de4855a8 by Christian Brauner
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network: use static memory for net device names

All network devices can only be of size < IFNAMSIZ. So let's spare the useless heap allocations and use static memory. Signed-off-by: 's avatarChristian Brauner <christian.brauner@ubuntu.com>
parent 99573f4a
Showing with 87 additions and 75 deletions
src/lxc/confile.c
......@@ -483,7 +483,7 @@ static int set_config_net_link(const char *key, const char *value,
if (value[strlen(value) - 1] == '+' && netdev->type == LXC_NET_PHYS)
ret = create_matched_ifnames(value, lxc_conf, netdev);
else
ret = network_ifname(&netdev->link, value);
ret = network_ifname(netdev->link, value);
return ret;
}
......@@ -503,7 +503,7 @@ static int set_config_net_name(const char *key, const char *value,
if (!netdev)
return -1;
return network_ifname(&netdev->name, value);
return network_ifname(netdev->name, value);
}
static int set_config_net_veth_pair(const char *key, const char *value,
......@@ -521,7 +521,7 @@ static int set_config_net_veth_pair(const char *key, const char *value,
if (!netdev)
return -1;
return network_ifname(&netdev->priv.veth_attr.pair, value);
return network_ifname(netdev->priv.veth_attr.pair, value);
}
static int set_config_net_macvlan_mode(const char *key, const char *value,
......@@ -3690,8 +3690,7 @@ static int clr_config_net_name(const char *key, struct lxc_conf *lxc_conf,
if (!netdev)
return -1;
free(netdev->name);
netdev->name = NULL;
netdev->name[0] = '\0';
return 0;
}
......@@ -3725,8 +3724,7 @@ static int clr_config_net_link(const char *key, struct lxc_conf *lxc_conf,
if (!netdev)
return -1;
free(netdev->link);
netdev->link = NULL;
netdev->link[0] = '\0';
return 0;
}
......@@ -3763,8 +3761,7 @@ static int clr_config_net_veth_pair(const char *key, struct lxc_conf *lxc_conf,
if (!netdev)
return -1;
free(netdev->priv.veth_attr.pair);
netdev->priv.veth_attr.pair = NULL;
netdev->priv.veth_attr.pair[0] = '\0';
return 0;
}
......@@ -4032,7 +4029,7 @@ static int get_config_net_link(const char *key, char *retv, int inlen,
if (!netdev)
return -1;
if (netdev->link)
if (netdev->link[0] != '\0')
strprint(retv, inlen, "%s", netdev->link);
return fulllen;
......@@ -4056,7 +4053,7 @@ static int get_config_net_name(const char *key, char *retv, int inlen,
if (!netdev)
return -1;
if (netdev->name)
if (netdev->name[0] != '\0')
strprint(retv, inlen, "%s", netdev->name);
return fulllen;
......@@ -4129,7 +4126,8 @@ static int get_config_net_veth_pair(const char *key, char *retv, int inlen,
return 0;
strprint(retv, inlen, "%s",
netdev->priv.veth_attr.pair ? netdev->priv.veth_attr.pair
netdev->priv.veth_attr.pair[0] != '\0'
? netdev->priv.veth_attr.pair
: netdev->priv.veth_attr.veth1);
return fulllen;
......
src/lxc/confile_legacy.c
......@@ -110,10 +110,6 @@ static void lxc_remove_nic(struct lxc_list *it)
lxc_list_del(it);
free(netdev->link);
free(netdev->name);
if (netdev->type == LXC_NET_VETH)
free(netdev->priv.veth_attr.pair);
free(netdev->upscript);
free(netdev->downscript);
free(netdev->hwaddr);
......@@ -174,6 +170,16 @@ int set_config_network_legacy_type(const char *key, const char *value,
lxc_list_init(&netdev->ipv4);
lxc_list_init(&netdev->ipv6);
netdev->name[0] = '\0';
netdev->link[0] = '\0';
memset(&netdev->priv, 0, sizeof(netdev->priv));
/* I'm not completely sure if the memset takes care to zero the arrays
* in the union as well. So let's make extra sure and set the first byte
* to zero so that we don't have any surprises.
*/
netdev->priv.veth_attr.pair[0] = '\0';
netdev->priv.veth_attr.veth1[0] = '\0';
list = malloc(sizeof(*list));
if (!list) {
SYSERROR("failed to allocate memory");
......@@ -423,7 +429,7 @@ int set_config_network_legacy_link(const char *key, const char *value,
free(it);
ret = create_matched_ifnames(value, lxc_conf, NULL);
} else {
ret = network_ifname(&netdev->link, value);
ret = network_ifname(netdev->link, value);
}
return ret;
......@@ -438,7 +444,7 @@ int set_config_network_legacy_name(const char *key, const char *value,
if (!netdev)
return -1;
return network_ifname(&netdev->name, value);
return network_ifname(netdev->name, value);
}
int set_config_network_legacy_veth_pair(const char *key, const char *value,
......@@ -455,7 +461,7 @@ int set_config_network_legacy_veth_pair(const char *key, const char *value,
return -1;
}
return network_ifname(&netdev->priv.veth_attr.pair, value);
return network_ifname(netdev->priv.veth_attr.pair, value);
}
int set_config_network_legacy_macvlan_mode(const char *key, const char *value,
......@@ -848,12 +854,12 @@ int get_config_network_legacy_item(const char *key, char *retv, int inlen,
if (!netdev)
return -1;
if (strcmp(p1, "name") == 0) {
if (netdev->name)
if (netdev->name[0] != '\0')
strprint(retv, inlen, "%s", netdev->name);
} else if (strcmp(p1, "type") == 0) {
strprint(retv, inlen, "%s", lxc_net_type_to_str(netdev->type));
} else if (strcmp(p1, "link") == 0) {
if (netdev->link)
if (netdev->link[0] != '\0')
strprint(retv, inlen, "%s", netdev->link);
} else if (strcmp(p1, "flags") == 0) {
if (netdev->flags & IFF_UP)
......@@ -895,7 +901,7 @@ int get_config_network_legacy_item(const char *key, char *retv, int inlen,
} else if (strcmp(p1, "veth.pair") == 0) {
if (netdev->type == LXC_NET_VETH) {
strprint(retv, inlen, "%s",
netdev->priv.veth_attr.pair
netdev->priv.veth_attr.pair[0] != '\0'
? netdev->priv.veth_attr.pair
: netdev->priv.veth_attr.veth1);
}
......
src/lxc/confile_utils.c
......@@ -183,6 +183,15 @@ struct lxc_netdev *lxc_network_add(struct lxc_list *networks, int idx, bool tail
memset(netdev, 0, sizeof(*netdev));
lxc_list_init(&netdev->ipv4);
lxc_list_init(&netdev->ipv6);
netdev->name[0] = '\0';
netdev->link[0] = '\0';
memset(&netdev->priv, 0, sizeof(netdev->priv));
/* I'm not completely sure if the memset takes care to zero the arrays
* in the union as well. So let's make extra sure and set the first byte
* to zero so that we don't have any surprises.
*/
netdev->priv.veth_attr.pair[0] = '\0';
netdev->priv.veth_attr.veth1[0] = '\0';
/* give network a unique index */
netdev->idx = idx;
......@@ -258,7 +267,7 @@ void lxc_log_configured_netdevs(const struct lxc_conf *conf)
switch (netdev->type) {
case LXC_NET_VETH:
TRACE("type: veth");
if (netdev->priv.veth_attr.pair)
if (netdev->priv.veth_attr.pair[0] != '\0')
TRACE("veth pair: %s",
netdev->priv.veth_attr.pair);
if (netdev->priv.veth_attr.veth1[0] != '\0')
......@@ -300,9 +309,9 @@ void lxc_log_configured_netdevs(const struct lxc_conf *conf)
if (netdev->type != LXC_NET_EMPTY) {
TRACE("flags: %s",
netdev->flags == IFF_UP ? "up" : "none");
if (netdev->link)
if (netdev->link[0] != '\0')
TRACE("link: %s", netdev->link);
if (netdev->name)
if (netdev->name[0] != '\0')
TRACE("name: %s", netdev->name);
if (netdev->hwaddr)
TRACE("hwaddr: %s", netdev->hwaddr);
......@@ -350,10 +359,6 @@ static void lxc_free_netdev(struct lxc_netdev *netdev)
{
struct lxc_list *cur, *next;
free(netdev->link);
free(netdev->name);
if (netdev->type == LXC_NET_VETH)
free(netdev->priv.veth_attr.pair);
free(netdev->upscript);
free(netdev->downscript);
free(netdev->hwaddr);
......@@ -503,9 +508,15 @@ int config_ip_prefix(struct in_addr *addr)
return 0;
}
int network_ifname(char **valuep, const char *value)
int network_ifname(char *valuep, const char *value)
{
return set_config_string_item_max(valuep, value, IFNAMSIZ);
if (strlen(value) >= IFNAMSIZ) {
ERROR("Network devie name \"%s\" is too long (>= %zu)", value,
(size_t)IFNAMSIZ);
}
strcpy(valuep, value);
return 0;
}
int rand_complete_hwaddr(char *hwaddr)
......
src/lxc/confile_utils.h
......@@ -77,7 +77,7 @@ extern int set_config_string_item_max(char **conf_item, const char *value,
size_t max);
extern int set_config_path_item(char **conf_item, const char *value);
extern int config_ip_prefix(struct in_addr *addr);
extern int network_ifname(char **valuep, const char *value);
extern int network_ifname(char *valuep, const char *value);
extern int rand_complete_hwaddr(char *hwaddr);
extern bool lxc_config_net_hwaddr(const char *line);
extern void update_hwaddr(const char *line);
......
src/lxc/criu.c
......@@ -524,7 +524,7 @@ static void exec_criu(struct criu_opts *opts)
case LXC_NET_VETH:
veth = n->priv.veth_attr.pair;
if (n->link) {
if (n->link[0] != '\0') {
if (external_not_veth)
fmt = "veth[%s]:%s@%s";
else
......@@ -543,7 +543,7 @@ static void exec_criu(struct criu_opts *opts)
goto err;
break;
case LXC_NET_MACVLAN:
if (!n->link) {
if (n->link[0] == '\0') {
ERROR("no host interface for macvlan %s", n->name);
goto err;
}
......@@ -765,11 +765,17 @@ static bool restore_net_info(struct lxc_container *c)
snprintf(template, sizeof(template), "vethXXXXXX");
if (!netdev->priv.veth_attr.pair)
netdev->priv.veth_attr.pair = lxc_mkifname(template);
if (netdev->priv.veth_attr.pair[0] == '\0' &&
netdev->priv.veth_attr.veth1[0] == '\0') {
char *tmp;
if (!netdev->priv.veth_attr.pair)
tmp = lxc_mkifname(template);
if (!tmp)
goto out_unlock;
strcpy(netdev->priv.veth_attr.veth1, tmp);
free(tmp);
}
}
has_error = false;
......
src/lxc/network.c
......@@ -101,7 +101,7 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
char veth1buf[IFNAMSIZ], veth2buf[IFNAMSIZ];
unsigned int mtu = 0;
if (netdev->priv.veth_attr.pair) {
if (netdev->priv.veth_attr.pair[0] != '\0') {
veth1 = netdev->priv.veth_attr.pair;
if (handler->conf->reboot)
lxc_netdev_delete_by_name(veth1);
......@@ -163,7 +163,7 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
WARN("Failed to parse mtu");
else
INFO("Retrieved mtu %d", mtu);
} else if (netdev->link) {
} else if (netdev->link[0] != '\0') {
bridge_index = if_nametoindex(netdev->link);
if (bridge_index) {
mtu = netdev_get_mtu(bridge_index);
......@@ -186,7 +186,7 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
}
}
if (netdev->link) {
if (netdev->link[0] != '\0') {
err = lxc_bridge_attach(netdev->link, veth1);
if (err) {
ERROR("Failed to attach \"%s\" to bridge \"%s\": %s",
......@@ -217,7 +217,7 @@ static int instantiate_veth(struct lxc_handler *handler, struct lxc_netdev *netd
out_delete:
if (netdev->ifindex != 0)
lxc_netdev_delete_by_name(veth1);
if (!netdev->priv.veth_attr.pair)
if (netdev->priv.veth_attr.pair != veth1)
free(veth1);
free(veth2);
return -1;
......@@ -228,7 +228,7 @@ static int instantiate_macvlan(struct lxc_handler *handler, struct lxc_netdev *n
char peerbuf[IFNAMSIZ], *peer;
int err;
if (!netdev->link) {
if (netdev->link[0] == '\0') {
ERROR("No link for macvlan network device specified");
return -1;
}
......@@ -279,7 +279,7 @@ static int instantiate_vlan(struct lxc_handler *handler, struct lxc_netdev *netd
static uint16_t vlan_cntr = 0;
unsigned int mtu = 0;
if (!netdev->link) {
if (netdev->link[0] == '\0') {
ERROR("No link for vlan network device specified");
return -1;
}
......@@ -308,7 +308,7 @@ static int instantiate_vlan(struct lxc_handler *handler, struct lxc_netdev *netd
if (lxc_safe_uint(netdev->mtu, &mtu) < 0) {
ERROR("Failed to retrieve mtu from \"%d\"/\"%s\".",
netdev->ifindex,
netdev->name ? netdev->name : "(null)");
netdev->name[0] != '\0' ? netdev->name : "(null)");
return -1;
}
err = lxc_netdev_set_mtu(peer, mtu);
......@@ -325,7 +325,7 @@ static int instantiate_vlan(struct lxc_handler *handler, struct lxc_netdev *netd
static int instantiate_phys(struct lxc_handler *handler, struct lxc_netdev *netdev)
{
if (!netdev->link) {
if (netdev->link[0] == '\0') {
ERROR("No link for physical interface specified");
return -1;
}
......@@ -380,7 +380,7 @@ static int shutdown_veth(struct lxc_handler *handler, struct lxc_netdev *netdev)
char *veth1;
int err;
if (netdev->priv.veth_attr.pair)
if (netdev->priv.veth_attr.pair[0] != '\0')
veth1 = netdev->priv.veth_attr.pair;
else
veth1 = netdev->priv.veth_attr.veth1;
......@@ -2014,7 +2014,7 @@ int lxc_find_gateway_addresses(struct lxc_handler *handler)
return -1;
}
if (!netdev->link) {
if (netdev->link[0] == '\0') {
ERROR("Automatic gateway detection needs a link interface");
return -1;
}
......@@ -2088,7 +2088,7 @@ static int lxc_create_network_unpriv_exec(const char *lxcpath, char *lxcname,
exit(EXIT_FAILURE);
}
if (netdev->link)
if (netdev->link[0] != '\0')
strncpy(netdev_link, netdev->link, IFNAMSIZ);
else
strncpy(netdev_link, "none", IFNAMSIZ);
......@@ -2100,8 +2100,8 @@ static int lxc_create_network_unpriv_exec(const char *lxcpath, char *lxcname,
INFO("Execing lxc-user-nic create %s %s %s veth %s %s", lxcpath,
lxcname, pidstr, netdev_link,
netdev->name ? netdev->name : "(null)");
if (netdev->name)
netdev->name[0] != '\0' ? netdev->name : "(null)");
if (netdev->name[0] != '\0')
execlp(LXC_USERNIC_PATH, LXC_USERNIC_PATH, "create",
lxcpath, lxcname, pidstr, "veth", netdev_link,
netdev->name, (char *)NULL);
......@@ -2140,11 +2140,6 @@ static int lxc_create_network_unpriv_exec(const char *lxcpath, char *lxcname,
return -1;
}
netdev->name = malloc(IFNAMSIZ + 1);
if (!netdev->name) {
SYSERROR("Failed to allocate memory");
return -1;
}
memset(netdev->name, 0, IFNAMSIZ + 1);
strncpy(netdev->name, token, IFNAMSIZ);
......@@ -2240,7 +2235,7 @@ static int lxc_delete_network_unpriv_exec(const char *lxcpath, char *lxcname,
exit(EXIT_FAILURE);
}
if (!netdev->link) {
if (netdev->link[0] == '\0') {
SYSERROR("Network link for network device \"%s\" is "
"missing", netdev->priv.veth_attr.veth1);
exit(EXIT_FAILURE);
......@@ -2423,7 +2418,7 @@ int lxc_network_move_created_netdev_priv(const char *lxcpath, char *lxcname,
}
DEBUG("Moved network device \"%s\"/\"%s\" to network namespace "
"of %d:", ifname, netdev->name ? netdev->name : "(null)",
"of %d:", ifname, netdev->name[0] != '\0' ? netdev->name : "(null)",
pid);
}
......@@ -2510,18 +2505,18 @@ bool lxc_delete_network_priv(struct lxc_handler *handler)
INFO("Interface \"%s\" with index %d already "
"deleted or existing in different network "
"namespace",
netdev->name ? netdev->name : "(null)",
netdev->name[0] != '\0' ? netdev->name : "(null)",
netdev->ifindex);
} else if (ret < 0) {
deleted_all = false;
WARN("Failed to remove interface \"%s\" with "
"index %d: %s",
netdev->name ? netdev->name : "(null)",
netdev->name[0] != '\0' ? netdev->name : "(null)",
netdev->ifindex, strerror(-ret));
continue;
}
INFO("Removed interface \"%s\" with index %d",
netdev->name ? netdev->name : "(null)",
netdev->name[0] != '\0' ? netdev->name : "(null)",
netdev->ifindex);
if (netdev->type != LXC_NET_VETH)
......@@ -2530,11 +2525,11 @@ bool lxc_delete_network_priv(struct lxc_handler *handler)
/* Explicitly delete host veth device to prevent lingering
* devices. We had issues in LXD around this.
*/
if (netdev->priv.veth_attr.pair)
if (netdev->priv.veth_attr.pair[0] != '\0')
hostveth = netdev->priv.veth_attr.pair;
else
hostveth = netdev->priv.veth_attr.veth1;
if (*hostveth == '\0')
if (hostveth[0] == '\0')
continue;
ret = lxc_netdev_delete_by_name(hostveth);
......@@ -2767,9 +2762,12 @@ static int lxc_setup_netdev_in_child_namespaces(struct lxc_netdev *netdev)
* When the IFLA_IFNAME attribute is passed something like "<prefix>%d"
* netlink will replace the format specifier with an appropriate index.
*/
if (!netdev->name)
netdev->name = netdev->type == LXC_NET_PHYS ?
netdev->link : "eth%d";
if (netdev->name[0] == '\0') {
if (netdev->type == LXC_NET_PHYS)
strcpy(netdev->name, netdev->link);
else
strcpy(netdev->name, "eth%d");
}
/* rename the interface name */
if (strcmp(ifname, netdev->name) != 0) {
......
src/lxc/network.h
......@@ -91,7 +91,7 @@ struct lxc_route6 {
* @ifindex : Ifindex of the network device.
*/
struct ifla_veth {
char *pair;
char pair[IFNAMSIZ];
char veth1[IFNAMSIZ];
int ifindex;
};
......@@ -151,8 +151,8 @@ struct lxc_netdev {
int ifindex;
int type;
int flags;
char *link;
char *name;
char link[IFNAMSIZ];
char name[IFNAMSIZ];
char *hwaddr;
char *mtu;
union netdev_p priv;
......
src/lxc/start.c
......@@ -816,13 +816,6 @@ static int read_unpriv_netifindex(struct lxc_list *network)
if (netdev->type != LXC_NET_VETH)
continue;
netdev->name = malloc(IFNAMSIZ);
if (!netdev->name) {
ERROR("Out of memory.");
close(netpipe);
return -1;
}
if (read(netpipe, netdev->name, IFNAMSIZ) != IFNAMSIZ) {
close(netpipe);
return -1;
......
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