netlink, pasta: Split MTU setting functionality out of nl_link_up()

As we'll use nl_link_up() for more than just bringing up devices, it
will become awkward to carry empty MTU values around whenever we call
it.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Stefano Brivio 2024-08-15 00:01:53 +02:00
parent b91d3373ac
commit 8231ce54c3
3 changed files with 33 additions and 14 deletions

View file

@ -942,14 +942,14 @@ int nl_link_set_mac(int s, unsigned int ifi, const void *mac)
}
/**
* nl_link_up() - Bring link up
* nl_link_set_mtu() - Set link MTU
* @s: Netlink socket
* @ifi: Interface index
* @mtu: If non-zero, set interface MTU
* @mtu: Interface MTU
*
* Return: 0 on success, negative error code on failure
*/
int nl_link_up(int s, unsigned int ifi, int mtu)
int nl_link_set_mtu(int s, unsigned int ifi, int mtu)
{
struct req_t {
struct nlmsghdr nlh;
@ -959,17 +959,32 @@ int nl_link_up(int s, unsigned int ifi, int mtu)
} req = {
.ifm.ifi_family = AF_UNSPEC,
.ifm.ifi_index = ifi,
.ifm.ifi_flags = IFF_UP,
.ifm.ifi_change = IFF_UP,
.rta.rta_type = IFLA_MTU,
.rta.rta_len = RTA_LENGTH(sizeof(unsigned int)),
.mtu = mtu,
};
ssize_t len = sizeof(req);
if (!mtu)
/* Shorten request to drop MTU attribute */
len = offsetof(struct req_t, rta);
return nl_do(s, &req, RTM_NEWLINK, 0, len);
return nl_do(s, &req, RTM_NEWLINK, 0, sizeof(req));
}
/**
* nl_link_up() - Bring link up
* @s: Netlink socket
* @ifi: Interface index
*
* Return: 0 on success, negative error code on failure
*/
int nl_link_up(int s, unsigned int ifi)
{
struct req_t {
struct nlmsghdr nlh;
struct ifinfomsg ifm;
} req = {
.ifm.ifi_family = AF_UNSPEC,
.ifm.ifi_index = ifi,
.ifm.ifi_flags = IFF_UP,
.ifm.ifi_change = IFF_UP,
};
return nl_do(s, &req, RTM_NEWLINK, 0, sizeof(req));
}

View file

@ -23,6 +23,7 @@ int nl_addr_dup(int s_src, unsigned int ifi_src,
int s_dst, unsigned int ifi_dst, sa_family_t af);
int nl_link_get_mac(int s, unsigned int ifi, void *mac);
int nl_link_set_mac(int s, unsigned int ifi, const void *mac);
int nl_link_up(int s, unsigned int ifi, int mtu);
int nl_link_set_mtu(int s, unsigned int ifi, int mtu);
int nl_link_up(int s, unsigned int ifi);
#endif /* NETLINK_H */

View file

@ -288,7 +288,7 @@ void pasta_ns_conf(struct ctx *c)
{
int rc = 0;
rc = nl_link_up(nl_sock_ns, 1 /* lo */, 0);
rc = nl_link_up(nl_sock_ns, 1 /* lo */);
if (rc < 0)
die("Couldn't bring up loopback interface in namespace: %s",
strerror(-rc));
@ -303,7 +303,10 @@ void pasta_ns_conf(struct ctx *c)
strerror(-rc));
if (c->pasta_conf_ns) {
nl_link_up(nl_sock_ns, c->pasta_ifi, c->mtu);
if (c->mtu != -1)
nl_link_set_mtu(nl_sock_ns, c->pasta_ifi, c->mtu);
nl_link_up(nl_sock_ns, c->pasta_ifi);
if (c->ifi4) {
if (c->ip4.no_copy_addrs) {